Title of Invention	MESOGENIC, CROSSLINKABLE MIXTURE LIQUID CRYSTALLINE POLYMER FILM MADE OF SAID MIXTURE AND PROCESS OF PREPARING SAID FILM.
Abstract	A mesogenic, crosslinkable mixture comprising at least one polymerisable liquid crystal and at least one polymerisable dichroic dye of the general formula (I) wherein A represents a dichroic residue exhibiting at least partial absorption in the visible region >400 nm; n1, n2, n3, n4 signifies 0 or 1 whereby the sum of n1, n2, n3, n4 is >0, and B1 to B4 represent a group of substructure II wherein the broken line symbolises the linkage to said dichroic residue. (FIG. -1 & 2)

Title of Invention

MESOGENIC, CROSSLINKABLE MIXTURE LIQUID CRYSTALLINE POLYMER FILM MADE OF SAID MIXTURE AND PROCESS OF PREPARING SAID FILM.

Abstract

A mesogenic, crosslinkable mixture comprising at least one polymerisable liquid crystal and at least one polymerisable dichroic dye of the general formula (I) wherein A represents a dichroic residue exhibiting at least partial absorption in the visible region >400 nm; n1, n2, n3, n4 signifies 0 or 1 whereby the sum of n1, n2, n3, n4 is >0, and B1 to B4 represent a group of substructure II wherein the broken line symbolises the linkage to said dichroic residue. (FIG. -1 & 2)

Full Text	MESOGENIC, CROSSLINKABLE MIXTURE, LIQUID CRYSTALLINE POLYMER FILM MADE OF SAID MIXTURE, AND PROCESS OF PREPARING SAID FILM The present invention relates to mesogenic, crosslinkable mixture, liquid crystalline polymer film made of said mixture, and process of preparing said film, and pertains to a new mixture of crosslinkable liquid crystals and polymerisable dichroic dyes and their use in the construction of unstructured and structured polarisers. Optical polarisers (hereinafter also called polarising films, polarisation films or polariser films) play a crucial role in the functioning principle of many optical or electro-optical devices, such as Liquid Crystal Devices, modem Security Elements, and the like. Furthermore, optical polarisers are also used in many instruments or devices, for example in different kinds of measuring instruments, dashboards or sunglasses, where stray light and undesired reflections have to be eliminated to improve visibility. Such polarising films usually comprise stretched polymer films such as, for example, polyvinyl alcohol (PVA), a dichroic absorber and other optional layers. Dichroic absorbers usually are iodine or dichroic dyes which are absorbed on or dissolved in the polymer film. US 5,707,544 describes liquid crystals characterised by a molecular architecture, wherein a chromophore is laterally attached to a polymerisable mesogenic core. Such compounds and liquid crystalline mixtures containing these are described to be useful mainly for non-linear optic devices or colour filters. Yet, a disadvantage of the most widespread polariser films based on iodine absorbers is their limited stability against humidity, heat and light. Polariser films based on dichroic dyes have a tendency to lose efficiency during time due to diffusion processes or inhomogeneities caused by partial crystallisation. A further drawback is the migration of dichroic dyes to adjacent layers if such systems are designed for use in multilayer systems as e.g. described in EP-A-06390S4.. Thus, there is clearly a need for a concept whereby all or at least some of the above disadvantages may be avoided.. Applicants have now found that certain mixtures comprising liquid crystals and dichroic dyes may be able to overcome the disadvantages described hereinabove. Thus, in a first aspect the present invention provides a mesogenic, crosslinkable mixture, wherein at least one compound comprises more than one polymerisable group in its structure, and which mixture comprises at least one polymerisable liquid crystal and at least one polymerisable dichroic dye selected from an azo dye, an anthraquinone, a benzoquinone, a perylene, an azulene or a merocyanine of the general formula I: wherein A represents a dichroic residue exhibiting at least partial absorption in the visible region > 400 nm; n1, n2, n3, n4 signify 0 or 1, whereby the sum of n1, n2, n3 and n4 is >0, and B1 to B4 represent a group of substructure II wherein the broken line symbolises the linkage to said dichroic residue and wherein : A1, A2, A3 each independently represent an aromatic or alicyclic group, which is unsubstituted or substituted by fluorine, chlorine, cyano, nitro, or a straight-chain or branched alkyl residue, which is unsubstituted, mono-substituted by cyano or halogeno, or poly-substituted by halogeno, having 1 to 18 carbon atoms, and wherein one or more of the non-adjacent CH2 groups may independently be replaced by Q, whereby Q represents -O-, -CO-, -CO-O-, -O-CO-, -Si(CH3)2-O-Si(CH3)2-, -NR2-, -NR2-CO-, -CO-NR2-, -NR2-CO-O-, -O-CO-NR2-, -NR2-CO-NR2-, -CH=CH-, -OC-, -O-CO-O-, and R2 represents hydrogen or straight-chain or branched C1-C6 alkyl, preferably straight-chain or branched C1-C3 alkyl; S1, S2 represent a single covalent bond or a spacer unit, such as a straight-chain or branched alkylene residue, which is unsubstituted, mono-substituted by cyano or halogeno, or poly-substituted by halogeno, having 1 to 24 carbon atoms, wherein one or more of the non-adjacent CH2 groups may independently be replaced by Q, wherein Q has the meaning given above; Z1, Z2 independently represent a single covalent bond or a spacer unit, such as a straight-chain or branched alkylene residue, which is unsubstituted, mono-substituted by cyano or halogeno, or poly-substituted by halogeno, having 1 to 8 carbon atoms, wherein one or more of the non-adjacent CH2 groups may independently be replaced by Q, -N=N- or -CR2=C-CO-, wherein Q and R2 have the meaning given above; P represents a polymerisable group; ml, m2, m3 independently are 0 or 1; and 0 is 0 or 1, whereby the sum of the symbols 0 in Bl to B4 is > 0. In a further aspect the invention also provides the use of said mesogenic crosslinkable mixtures for the production of dichroic crosslinked films as well as their use in the construction of unstructured and structured optical elements and multi-layer systems as for example, for colour filters, polarisers and for me construction of security devices. These new polymerisable dichroic mixtures show good homogeneous alignment and upon crosslinking do not exhibit inhomogeneities or changes of the dichroitic ratio due to relaxation, diffusion or micro crystallisation processes over time. The term "crosslinkable mixture" refers to a mixture comprising at least one compound that comprises more than one polymerisable group in its structure. The term "dichroic residue" refers to a dichroic dye exhibiting positive or negative dichroism structurally reduced to the pure chromophore systems. It is to be understood that the term "aromatic" comprises optionally substituted carbocyclic and heterocyclic groups comprising five-, six- or ten-membered ring systems, such as furane, phenyl, pyridine, pyrimidine, naphthalene, or tetraline units. It is to be understood that the term "alycyclic" comprises non-aromatic carbocyclic or heterocyclic ring systems having 3 to 10 carbon atoms, such as cyclopropane, cyclobutane, cyclopentane, cyclopentene, cyclohexane, cyclohexene, cyclohexadiene and decaline. It is to be understood that the phrase "cyclic, straight-chain or branched aikyl group, which is optionally substituted by a single cyano group or by one or more halogen atoms, and in which one or more of the non-adjacent -CH2- groups may be optionally replaced by a group Q" comprises groups selected from the group comprising methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, terr-butyl, pentyl, isopentyl, cyclopentyl, hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, 3-merhylpentyl, allyl, but-3-en-l-yl, pent-4-en-l-yl, hex-5-an-l-yl, propynyl, butynyl, pentynyl, rnethoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy, tert-butoxy, pentyloxy, isopentyloxy, cyclopentyloxy, hexyloxy, cyclohexyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy, undecyloxy, dodecyloxy, 3-methylpentyloxy, allyloxy, but-3-enyloxy, pent-4-enyloxy, cylohexylmethoxy, cyclopentylmethoxy, methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, isopropoxycarbonyl, butoxycarbonyl, isobutoxycarbonyl, sec-butoxycarbonyl, tert-butoxycarbonyl, pentyloxycarbonyl, isopentyloxycarbonyl, cyclopentyloxy- carbonyl, hexyloxycarbonyl, cyclohexyloxycarbonyl, octyloxycarbonyl, nonyloxy- carbonyl, decyloxycarbonyl, undecyloxycarbonyl, dodecyloxycarbonyl, 3-methylpentyloxycarbonyl, allyloxycarbonyl, but-3-enyloxycarbonyl, pent-4-enyl- oxycarbonyl, cylohexylmethoxycarbonyl, cyclopentylmethoxycarbonyl, acetoxy, ethylcarbonyloxy, propylcarbonyloxy, isopropylcarbonyloxy, butylcarbonyloxy, isobutylcarbonyloxy, sec-butylcarbonyloxy, tert-butylcarbonyloxy, pentyl- carbonyloxy, isopentylcarbonyloxy, cyclopentylcarbonyloxy, hexylcarbonyloxy, cyclohexylcarbonyloxy, octylcarbonyloxy, nonylcarbonyloxy, decylcarbonyloxy, undecylcarbonyloxy, dodecylcarbonyloxy, 3-methylpentylcarbonyloxy, but-3-enyloxy, pent-4-enyloxy, acetyl, ethylcarbonyl, propylcarbonyl, isopropyl- carbonyl, butylcarbonyl, isobutylcarbonyl, sec-butylcarbonyl, pentylcarbonyl, isopentylcarbonyl, cyclohexylcarbonyl, octylcarbonyl, nonylcarbonyl, decylcarbonyl, undecylcarbonyl, dodecylcarbonyl, methoxyacetoxy, 1-methoxy-2-propoxy, 3-methoxy-l-propoxy, 2-methoxyethoxy, 2-isopropoxyethoxy, 1-ethoxy-3-pentyloxy, 3-butynyloxy, 4-pentynyloxy, 5-chloropentynyl, 4-peatynecarbonyloxy, 6-propyloxy- hexyl, 6-propyloxyhcxyloxy, 2-fluoroethyl, trifluoromethyl, 2,2,2-trifluoroethyl. 1H, 1H-pentadecafluorooctyl, 1H, lH,7H-dodecafluoroheptyl, 2-(perfluorooctyl)ethyl, 2-(perfluorobutyl)ethyl, 2-(perfluorohexyl)ethyl, 2-(perfluorodecyl)ethyl, perfluoro- propyl, perfluorobutyl, perfluoroheptyl, perfluorooctyl, perfluorononyl. 1-fluoropropoxy, 1-fluoropentyloxy, 2-fluoropropoxy, 2,2-difluoropropoxy, 3-fluoropropoxy, 3,3-difluoropropoxy, 3,3,3-trifluoropropoxy, and trifluoromethoxy. It is to be understood that the term "lower alkyl" comprises straight chain and branched hydrocarbon radicals having 1 to 6 carbon atoms, preferably 1 to 3 carbon atoms. Methyl, ethyl, propyl and isopropyl groups are especially preferred. Dichroic dyes, of which the dichroic residues A are derived fr are described in the literature, e.g. in Molecular Crystals, Liquid Crystals 150A, (1987). In a preferred embodiment the dichroic dyes of the present invention include azo dyes, anthraquinones, benzoquinones, perylenes, azulenes, and merocyanines. Particularly preferred dichroic dyes of the present invention include dyes comprising azo- or anthraquinone residues. The sum of substituents B attached to a dichroic residue A expressed by (n1 + n2 -N3 - n4) is preferably ? 3, more preferably ? 2. Preferred rings A1, A2 and A3 independently of each other are unsubstituted, saturated five- or six-membered alicyclic rings or six-membered aromatic rings, optionally substituted by fluorine or chlorine or nitro or by a straight chain or branched alkyl residue, which is unsubstituted, mono- or poly-substituted by fluorine having 1-12 carbon atoms, wherein one or more of the non-adjacent CH2 groups may independently be replaced by -O-, -CO-O-, -O-CO-, -NR2-CO-, -CO-NR2-, -NR2-CO-O-, -O-CO-NR2-, -CH=CH-, -C=C-, -O-CO-O-, wherein R2 represents hydrogen or lower alkyl. Particularly preferred rings A1, A2 and A3 include unsubstituted cyclopentane-1,3- diyl, unsubstituted cyclohexane-l,4-diyl, or 1,4-phenylene, which is unsubstituted, mono- or poly-substituted by fluorine or chlorine or a straight-chain or branched alkyl residue, which is unsubstituted, mono- or poly-substituted by fluorine having 1-12 carbon atoms, wherein one or more of the non-adjacent CH2 groups may independently be replaced by -O-, -CO-O-, -O-CO-, -CH=CH-, -C=C-. Preferred "spacer units" S1 and S2 of the present invention comprise ? single bond, or a straight-chain or branched alkylene grouping, such as -(CH2)r-, and also -(CH2)r-O-, -(CH2)r-CO-, -(CH2)r-CO-O-, -(CH2)rO-CO-, -(CH2)r-CO-NR2-, -(CH2)r-NR2-CO-, -(CH2)r-NR2-, -(CH2)r-O-(CH2)s-, -(CH2)rCO-O-(CH2)s-, -(CH2)rO-CO-(CH2)s-, -(CH2)r-NR2-CO-(CH2)s-, -(CH2)r-XR2-CO-O-(CH2)s-, -(CH2)r-O-(CH2)s-O-, -(CH2)r-CO-O-(CH2)s-O-, -(CH2)r-O-CO-(CH2)s-O-, -(CH2)rNR2-CO-(CH2)s-O-, -(CH2)r-XR2-CO-O-(CH2)s-O-, -O-(CH2)r, -CO-O-(CH2)r, -O-CO-(CH2)r, -XR2-CO-(CH2)r, -CO-NR2-(CH2)r, -NR2-(CH2)r-, -O-(CH2)r-CO-O-, -O-(CH2)r-O-CO-, -O-(CH2)r-CO-NR2-, -O-(CH2)r-NR2-, -O-(CH2)r-O-, -O-(CH:)r-NR2-CO-, -NR2-(CH2)r-CO-O-, -NR2-(CH2)r-O-, -NR2-(CH2)r-NR2-, -NR2-(CH2)rO-CO-, -CO-NR2-(CH2)rO-, -CO-NR2-(CH2)r-NR2-, -CO-NR2-(CH2)r-O-CO-, -O-CO-(CH2)r-CO-, -O-CO-(CH2)r-O-, -O-CO-(CH2)r-NR2-, -O-CO-(CH2)r-CO-O-, -O-CO-(CH2)r-CO-NR2-, -O-CO-(CH2)r-NR2-CO-, -O-(CH2)r-O-(CH2)s-, -O-(CH2)r-CO-O-(CH2)s-, -O-(CH2)r-NR2-CO-(CH2)s-, -O-(CH2)r-NR2-CO-O-(CH2)s-, -O-(CH2)r-CO-O-(CH2)s-O-, -O-(CH2)r-O-(CH2)s-O-, -O-(CH2)r-NR2-CO-(CH2)s-O-, -O-(CH2)rNR2-CO-O-(CH2)s-O-, -CO-O-(CH2)r-O-(CH2)s-, -CO-O-(CH2)r-O-(CH2)s-O-5 wherein r and s are each an integer from 1 to 20, the sum of r ÷ s ? 21, wherein R2 represents hydrogen or lower alkyl, and which are attached to the dichroic residue and the polymerisable group, respectively, such that heteroatoms are not directly linked to each other. Particularly preferred "spacer units" S1 comprise a single bond, a straight-chain alkylene grouping, such as -(CH2)r, and also -(CH2)r-O-, -(CH2)r-CO-O-, -(CH2)r-O-CO-, -(CH2)r-CO-NH-5 -(CH2)rNH-CO-, -(CH2)r-NH-CO-(CH2)s-, -(CH2)r-NH-CO-O-(CH2)s-; -(CH2)rO-(CH2)s-O-, -(CH2)rNH-CO-(CH2)s-O-, -(CH2)r-NH-CO-O-(CH2)s-O-, -O-(CH2)r, -CO-O-(CH2)r, -CO-NH-(CH2)r, -O-CO-(CH2)r, -O-CO-(CH2)r-CO-O-, -O-(CH2)r-O-CO-, -O-(CH2)rCO-NH-, -O-(CH2)r-NH-CO-, -CO-O-(CH2)rO-, -CO-NH-(CH2)rO-, -O-(CH2)r-O-, -O-(CH2)r-NH-CO-(CH2)s-, -O-(CH2)r-O-(CH2)s-O-, -O-CO-(CH2)r-O-(CH2)s-O-, -CO-O-(CH2)r-O-(CH2)s-O-, -O-(CH2)rNH-CO-(CH2)s-O-, -O-CO-("H2)r-NH-CO-(CH2)s-O-, wherein r and s are each an integer from 1 to 16, the sum of r - s ? 18 and which are attached to the dichroic residue and the polymerisable group, respectively, such that heteroatoms are not directly linked to each other. Most preferred "spacer units" of S1 comprise single bond, a straight-chain alkylene grouping represented by -(CH2)r-, and also -(CH2)r-O-, -(CH2)r-CO-O-, -(CH2)r-O-CO-, -(CH2)r-O-(CH2)s-O-, -(CH2)r-NH-CO-O-(CH2)s-O-, and if attached to a carbon atom of the dichroic residue also -O-(CH2)r-, -CO-O-(CH2)r-, -O-CO-(CH2)r-, -O-CO-(CH2)r-CO-O-, -O-(CH2)r-O-CO-, -CO-O-(CH2)r-O-, -O-(CH2)r-O-, -O-(CH2)r-O-(CH2)s-O-, -O-CO-(CH2)r-O-(CH2)s-O-, -CO-O-(CH2)r-O-(CH2)s-O-, wherein r and s are each an integer from 1 to 12, the sum of r + s ? 14, and which are attached to the dichroic residue and the polymerisable group, respectively, such that heteroatoms are not directly linked to each other. Examples of preferred "spacer units" S1 comprise 1,2-ethylene, 1,3-propylene, 1,4-butylene, 1,5-pentylene, 1,6-hexylene, 1,7-heptylene, 1,8-octylene, 1,9-nonylene, 1,10-decylene, 1,11-undecylene, 1,12-dodecylene, 3-methyl-1,4-butylene, 3-propyleneoxy, 3-propyleneoxycarbonyl, 2-ethylenecarbonyloxy, 4-butyleneoxy, 4-butyleneoxycarbonyl, 3-propylenecarbonyloxy, 5-pentyleneoxy, 5-pentyleneoxycarbonyl, 4-butylenecarbonyloxy, 6-hexyleneoxy, 6-hexyleneoxyc- arbonyl, 5-pentylenecarbonyloxy, 7-heptyleneoxy, 7-heptyleneoxycarbonyl, 6-hexylenecarbonyloxy, 8-octyleneoxy, 8-octyleneoxycarbonyl, 7-heptylenecarbonyl- oxy, 9-nonyleneoxy, 9-nonyleneoxycarbonyl, 8-octylenecarbonyloxy, 10-decylene- oxy, 10-decyleneoxycarbonyl, 9-nonylenecarbonyloxy, 11-undecyleneoxy, 11-undecyleneoxycarbonyl, 10-decylenecarbonyloxy, 12-dodecyleneoxy, 12-dodecyleneoxycarbonyl, 11-undecylenecarbonyloxy, 3-propyleneiminocarbonyl, 4-butyleneiminocarbonyl, 5-pentyleneiminocarbonyl, 6-hexyleneiminocarbonyl, 7-heptyleneiminocarbonyl, 8-octyleneiminocarbonyl, 9-nonyleneiminocarbonyl, 10-decyleneiminocarbonyl, 11-undecyleneiminocarbonyl, 12-dodecyleneimino- carbonyl, 2-ethylenecarbonylimino, 3-propylenecarbonylimino, 4-butylenecarbonyl- imino, 5-pentylenecarbonylimino, 6-hexylenecarbonylimino, 7-heptylenecarbonyl- imino, 8-octylenecarbonylimino, 9-nonylenecarbonylimino, 10-decylenecarbonyl- imino, 11-undecylenecarbonylimino, 6-(3-propyleneiminocarbonyloxy)hexyl, 6-(3-propyleneoxy)hexyl, 6-(3-propyleneoxy)hexyloxy, 6-(3-propyleneimino- carbonyloxy)hexyloxy, 6-(3-propyleneiminocarbonyl)hexyl, 6-(3-propyleneimino- carbonyl)hexyloxy, 1,2-ethylenedioxy, 1,3-propylenedioxy, 1,4-butylenedioxy, 1,5-pentylenedioxy, 1,6-hexylenedioxy, 1,7-heptylenedioxy, l,S-octylenedioxy, 1,9-nonylenedioxy, 1,10-decylenedioxy, 1,11-undecylenedioxy, and 1,12-dodecylene- dioxy. Preferred Z1 and Z2 groups comprise . a single covalent bond or a straight-chain or branched alkylene residue, which is unsubstituted, mono-substituted or poly-substituted by fluoro, having 1 to 8 carbon atoms, wherein one or more of the non-adjacent CH2 groups may independently be replaced by -O-, -CO-, -CO-O-, -O-CO-, -NR2-CO-, -CO-NR2-, -NR2-CO-O-, -O-CO-NR2-, -CH=CH-, -C=C-, -O-CO-O-, -N=N-, -CR2=C-CO-, wherein R2 represents hydrogen or lower alkyl. Panicularly preferred Z1 and Z2 groups comprise a single covalent bond or a straight-chain or branched alkylene residue, having 1 to 6 carbon atoms, wherein one or more of the non-adjacent CH2 groups may independently be replaced by -O-, -CO-O-, -O-CO-, -CH=CH-, -OC-, -O-CO-O-, -N=N-, -CR2=C-CO-, wherein R2 represents hydrogen or lower alkyl. Most preferred Z1 and Z2 groups comprise a single covalent bond or a straight-chain or branched alkylene residue, having 1 to 4 carbon atoms, wherein one or two of the non-adjacent CH2 groups may independently be replaced by -O-, -CO-O-, -O-CO-, -N=N-. Polymerisable groups P are preferably selected from the formulae CH2=CW-. CH2=CW-COO-, CH2=CH-CO-NH-, CH2=C(Ph)-CO-NH-, CH2=CH-O-, CH2=CH-OOC-, Ph-CH=CH-, CH2=CH-Ph-, CH2=CH-Ph-O-, R3-Ph-CH=CH-COO-, R3-OOC-CH=CH-Ph-O-, N-maleinimidyl, wherein W is hydrogen, chloro or methyl, R3 is lower alkyl or lower alkoxy, Ph- is phenyl and -Ph- is 1,4-phenylene. Particularly preferred groups P comprise CH2=CW-, CH2=CW-COO-, CH2=CH-O- wherein W is hydrogen or methyl. The number of rings in substructure II expressed by m1 + m2 + m3 is preferably ? 2. Polymerisable liquid crystals (LCP) which are present in the inventive mixtures are well known to the skilled person e.g. from EP 0331233 , WO 95/24454, US 5,567,349, US 5,650,534, WO 00/04110, WO 00/07975, WO 00/48985, WO 00/55110 and WO 00/63154. For adjustment of mesomorphic properties and suppression of crystallisation, mixtures of two or more LCP components may generally be used. At least one of the LCP components may optionally comprise more than one polymerisable group in the chemical structure in order to achieve crosslinking. As an alternative or to improve crosslinking abilities the addition of isotropic compounds comprising two or more polymerisab-e groups, so called crosslinkers, may also be possible. Furthermore well known additives such as, e.g. phenol derivatives for stabilisation and photoinitiators such as, e.g. Irgacure® may also be present in the inventive mixture. The number of dyes of formula I present in the mixture may depend mainly on the spectral working range of the polariser and on the solubility of the dyes. Coloured polariscrs, which are absorbing in a selective spectral range may preferably be achieved by the presence of one or two, black polarisers, selectively absorbing in the whole visible range by the presence of three or more dyes in the mixture. Preferred mixtures of the invention consequently comprise at least one dichroic dye according to the general formula I and at least two polymerisable liquid crystals, wherein at least one of them comprises more than one polymerisable group and optionally additives, such as crosslinkers, stabilisers and photoinitiators. Particularly preferred are mixtures comprising one to four dichroic dyes of formula I and at least two polymerisable liquid crystals comprising each two polymerisable groups and optionally additives such as crosslinkers, stabilisers and photoinitiators. The total content of dichroic dyes of formula I in the inventive mixture may depend on different factors such as solubility in the LCP host, influence on the mesomorphic properties (e.g. depression of clearing point) and absorption ability (extinction) of the dyes involved. Preferred dye concentrations may be in the range of 0.1 to 50%wt, more preferably from 0.5 to 30%wt, most preferably from 0.5 to 20%wt. Dichroic dyes from the class of azo dyes suitable for the inventive mixtures may preferably be selected from the groups according to general formulae III - V: R4-Ar1-N=N-Ar2-B1 III R4-Ar1-N=N-Ar2-N=N-Ar3-B1 IV R4-Ar1-N=N-Ar-2-N=N-Ar3-N=N-Ar4-B1 V wherein R4 represents hydrogen, fluoro, chloro, bromo, cyano, nitro, -NR2R3, a three- to seven-membered cyclic amino group, -CR2=CR3-NO2, -CR2=CR3-CN, -CR2=C(CN)2, or a straight chain or branched alkyl residue, which is unsubstituted, mono- or poly-substituted by fluorine having 1-18 carbon atoms, wherein one or more of the non-adjacent CH2 groups may independently be replaced by -O-, -CO-O-, -O-CO-, -NR2-CO-, -CO-NR2-, -NR2-CO-O-, -O-CO-NR2-, -CH=CH-, -OC-, -O-CO-O-, wherein R2 and R3 independently represent hydrogen or lower alkyl; Ar1, Ar2, Ar3, Ar4 independently of each other are 1,4-phenylene, 1,4- or 1,5- naphthylene optionally substituted by fluorine, chlorine, hydroxy, -NR2R3 or by a straight chain or branched alkyl residue, which is unsubstituted, mono- or poly-substituted by fluorine having 1-12 carbon atoms, wherein one or more of the non-adjacent CH2 groups may independently be replaced by -O-, -CO-O-, -O-CO-, -NR2-CO-, -CO-NR2-, -NR2-CO-0-, -O-CO-NR2-, -CH=CH-, -C=C-, -O-CO-O-, wherein R2 and R3 independently represent hydrogen or lower alkyl; and wherein Ar1 is also a group of formula a) to c) wherein p is an integer of 1 to 3 and R4 of formulae III to V is attached to the nitrogen atom; and B1 has the meaning given above. The dyes of formula III to V are new and represent a further aspect of the present invention. Preferred dyes of formula III to V include those wherein R4 represents hydrogen, chloro, cyano, nitro, -NR2R3, 1-piperidyl- 1-pyrrolidyl or a straight chain or branched alkyl residue, which is unsubstituted, having 1-12 carbon atoms, wherein one or two of the non-adjacent CH2 groups may independently be replaced by -O-, -CO-O-, -O-CO-, -CH=CH-, wherein R2 and R3 independently represent hydrogen or lower alkyl; Preferred dyes of formula III to V include also those where Ar1 to Ar4 independently of each other are 1,4-phenylene or 1,4-naphthylene optionally substituted by chlorine, hydroxy, -NR2R3 or by a straight chain or branched alkyl residue, which is unsubstituted, having 1-12 carbon atoms, wherein one or two of the non-adjacent CH2 groups may independently be replaced by -O-, -CO-O-, -O-CO-, -CH=CH-, wherein R2 and R3 independently represent hydrogen or lower alkyl; and wherein Ar1 additionally is a group of formula a) to c). Preferred azo dyes of formula III may comprise no 1,4-naphtylene units, preferred azo dyes of formula IV at most one 1,4-naphtylene unit, and preferred azo dyes of formula V not more than two 1,4-naphtylene units. Dichroic dyes from the class of anthraquinones suitable for the mixtures of the present invention may preferably be selected from the groups according to formulae VI-X: wherein one to four hydrogen atoms are substituted by the groups of B1 to B4 either at carbon or nitrogen atoms, and wherein B1 to B4 have the meaning given above, with the provision that at most one of B1 to B4 is attached to the same nitrogen atom. Such anthraquinone dyes are new and represent a further aspect of the present invention. Preferred anthraquinone dyes may comprise one or two of the groups B1 to B4. Further preferred anthraquinone dyes may be represented by the formulae VI, VII or X. The dichroic azo dyes of formula III to V and the dichroic anthraquinone dyes based on formulae VI to X may readily be prepared using methods well known to the person skilled in the art, such as those documented in Houben-Weyl, Methoden der Organischen Chemie, Thieme-Verlag, Stuttgart or in Molecular Crystals and Liquid Crystals Vol. 150A, 1987. The polymerisable liquid crystalline mixtures according to the present invention may further be formed into liquid crystalline polymer films (LCP films). Thus, in a further aspect the invention provides dichroic films formed from mixtures according to the present invention. Such LCP films may readily be prepared by UV or thermal polymerisation of the mixtures of the present invention. A film comprising a mixture according to the present invention is formed on a substrate, for example, by first preparing a solution of a mixture, which is subsequently applied to a support by different coating techniques, such as spincoating, miniscuscoating, wirecoating, slotcoating, offsetprinting, flexoprinting, gravureprinting. After evaporation of the solvent the obtained film is polymerised using UV light to give a cross-linked dichroic liquid crystal film of preferably 0.5 to 5 µm thickness. If required such films may further be coated with other layers, such as, e.g. protective layers for protection against oxygen, UV-irradiation or mechanical stress. Such films may be used in the manufacture of devices such as polarisers or optical filters. Examples of substrates used in the preparation of dichroic LCP films may include transparent substrates, such as glass or plastic including an orientation layer, which is able to induce a uniform orientation to the mixture. Such orientation layers may include rubbed polyimide, or polyamide or preferably layers of photo-orientable materials. A well-suited kind of photo-orientable orientation layers are Linearly Photopolymerisable Polymers (LPP), also sometimes referred to as Photooriented Polymer Networks (PPN). Backgrounds and manufacturing of such orientation layers are disclosed in, for example, US 5,389,698, US 5,838,407, US 5,602,661, US 6,160,597, US 6,144,428, all of the applicant. Using LPP layers, segments (pixels) of locally varying orientation may be formed. Thus, not only uniformly aligned dichroic LCP layers but also structured complex orientation patterns within the dichroic LCP layers may be produced. Furthermore multilayer systems formed from stacks of alternating LPP and LCP layers, wherein at least one of the LCP layers is a dichroic LCP layer are feasible. Such layers or stacks of layers may additionally be covered by other well known functional layers, such as, e.g. protecting layers against oxygen or humidity or layers for protection against ultraviolet radiation. Recently it has been shown, e.g. in WO 99/64924, that photo-orienting materials like LPPs may also be able to orient liquid crystals, such as LCPs, if they are admixed to the mixture to be oriented prior to illumination with polarised light. In this way, orientation layers and LCP layers need not be formed separately. Thus, an analogous preparation of a dichroic LCP film using an inventive mixture, which in addition contains a photo-orientable material, may also be possible. The dichroic mixtures and films of the present invention may be used to prepare electro-optical and optical devices including security devices. A further aspect of the invention therefore provides an electro-optical or optical component or a security device comprising a dichroic liquid crystalline polymer film formed from a mixture of the invention. Examples of optical or electro-optical components may include structured or unstructured optical filters, polarisers or elements of security devices. The following non-limiting examples further describe the present invention. Variations on these falling within the scope of the invention will be apparent to a person skilled in the art. EXAMPLE 1 Preparation of 4-(6-Acryloyloxyhexyloxy)phenyl-1,4-diarminoanthraquinone-2- carboxylate: To a mixture of 0.16 g of 4-(6-acryloyloxyhexyloxy)phenyl-l-amino-4- nitroanthraquinone-2-carboxylate, 16 ml of dimethylformamide, and 2 ml of water was added at room temperature 0.465 g of iron-III-chloride and 0.281 g of zinc powder. The reduction was allowed to proceed for 15 h under continuous stirring. Then the reaction mixture was extracted with methylenechloride, the organic phases were collected and washed with water, dried over sodium sulphate, filtered and concentrated to dryness. Chromatography of the residue on silica using 5% ethylacetate in toluene and subsequent crystallisation from ethyl acetate/hexane (1:2) gave 0.12 g of blue crystals; ?max. (CH2Cl2): 624 nm (? = 10"100), 590 nm (? = 10"133). The starting material was prepared in accordance with the following procedure: Preparation of 4-(6-Acryloyloxyhexyloxy)phenyl-1-amino-4-nitroanthraquinone-2- carboxylate: To a mixture of 0.43 g of 4-(6-hydroxyhexyloxy)phenyl-l-amino-4- nitroanthraquinone-2-carboxylate, 20 ml of methylenechloride, 0.015 g of N,N- dimethylaminopyridine, and 0.117 ml of acrylic acid were added dropwise 0.246 g of dicyclohexylcarbodiimide in 10 ml of methylenechloride. The mixture was stirred for 15 h at room temperature, then filtered and the solution concentrated to dryness. Chromatography of the residue on silica, using 2.5% ethylacetate in toluene and crystallisation from ethylacetate/hexane (2:1) gave 0.16 g of red crystals; ?max. (CH2Cl2): 482 nm (? = 7,647). Preparation of 4-(6-Hydroxyhexyloxy)phenyl-1-ar-O-4-mtroanthraquinone-2- carboxylate: A mixture of 0.9 g of 4-(6-(2-tetrahydropyranyl)oxyhexyloxy)phenyl-l-amino-4- nitroanthraquinone-2-carboxylate, 40 ml of methanol and 20 ml of 2N hydrochloric acid was stirred for 15 h at room temperature. The reaction mixture was then extracted with ether and the organic phase was washed with sodium bicarbonate and water and dried over sodium sulphate. Subsequent filtration and concentration to dryness gave 0.43 g of a red solid. Preparation_____of_____4-( 6-( 2-Tetrahvdropyranyl)oxyhexyloxy)phenyl-1-amino-4- nitroanthraquinone-2-carboxylate: To a mixture of 0.8 g of l-amino-4-nitroanthraquinone-2-carboxylic acid (commercially available from Bayer), 0.904 g of 4-(6-(2- tetrahydropyranyl)oxyhexyloxy)phenol, 30 ml of methylenechloride and 0.044 g of N,N-dimethylaminopyridine was added dropwise at 15°C 0.74 g of dicyclohexylcarbodiimide in 15 ml of methylenechloride. The reaction mixture was then stirred for 15 h at room temperature. Subsequent filtration and concentration to dryness gave 0.9 g of the product as a red solid. Preparation of 4-(6-(2-Tetrahydropyranyl)oxyhexyloxy)phenol: A mixture of 10 g of 2-(6-chlorohexyloxy)tetrahydropyrane, 25 g of hydroquinone, 31 g of potassiumcarbonate, 0.752 g of potassiumiodide and 250 ml of dimethylsulfoxide was allowed to react for 4 days at 80°C. Subsequently, the reaction mixture was cooled to room temperature and after addition of water extracted with ether. The organic phase was then dried over sodium sulphate, filtered and concentrated to dryness. Chromatography on silica with 10% ethylacetate in toluene gave llg of product as a yellowish oil. Preparation of 2-(6-Chlorohexyloxy)tetrahydropyrane: To a mixture of 15 g of 6-chlorohexanol, 100 ml of methylenechloride and 0.2 g of p- toluenesulphonic acid were added dropwise 12 g of diliydropyrane in 40 ml of methylenechloride. The reaction mixture was stirred for 15 h at room temperature and then distributed between ether and saturated sodium bicarbonate solution. The ether phase was washed with water, dried over sodium sulphate, filtered and concentrated to dryness. Chromatography of the residue on silica using hexane/ether (3:1) gave 21 g of the product as a colourless oil. The following compounds were synthesised using a similar method as described above: 4-(4-(6-Acryloyloxyhexyloxy)phenyloxycarbonyl)phenyl-1-4-diaminoanthraquinone- 2-carboxylate : ?max. (CH2C12): 625 nm (? = 12"995), 599 nm (? = 12,900). 6-(4-(4-(6-Acryloyloxyhexyloxy)phenyloxycarbonyl)phenyloxy)hexyl-l,4- diaminoanthraquinone-2-carboxylate: ?max. (CH2C12): 624 nm (? = 11"306), 590 nm (? = 11"404). 6-Acryloyloxyhexyloxy -1,4-diaminoanthraquinone-2-carboxylate: ?max. (CH2C12): 624 nm (? = 11"921), 591 nm (? = 11"789). EXAMPLE 2 Preparation of (4-heptylphenyl)- 4-acrylamido-1-aminoanthraquinone-2-carboxylate: To a stirred solution of 0.91 g of (4-heptylphenyl)-l,4-diaminoanthraquinone-2- carboxylate (preparation analogous to example 1) in 80 ml of methylenechloride, cooled to 0°C was added dropwise (over a period of 30 min) a solution of 0.36 g of acryloylchloride in 20 ml of methylenechloride . After stirring for 1 h at 0 °C and 30 min at room temperature, DMAP was added and stirring was continued for further 60 min. The reaction mixture was then concentrated to half its volume and passed through a silica gel column using methylenechloride as the eluent. The afforded violet solid was further recrystallised from ethanol/methylenechloride 9/1 (v/v) to give 0.88 g (4-heptylphenyl)-4-acrylamido-l-aminoanthraquinone-2-carboxylate as violet crystals; ?max. (CB 483): 572 nm. EXAMPLE 3 Preparation of 1,4-di-N-[4-(6-Acryloyloxyhexyloxy)benzyl1aminoanthraquinone: A mixture consisting of 4.8 g of 4-(6-acryloyloxyhexyloxy)benzylbromide , 0.48 g of 1,4-diaminoanthraquinone and 1.38 g of potassium carbonate in 20 ml of DMF was stirred under nitrogen atmosphere for 6 h at room temperature. The reaction mixture was then quenched with 100 ml 3 N HC1 and extracted with ethylacetate (2 x 150 ml). The combined organic extracts were washed with saturated NaCl solution (100 ml), dried over sodium sulphate and concentrated to dryness to give a blue residue. Chromatography on silica using 5% diethylether with methylenechloride gave 0.9 g of pure l,4-di-N-[4-(6-acryloyloxyhexyloxy)benzyl]ammoanthraquinone as blue crystals; ?max. (CB 483): 604 mn. The starting material was synthesised according to the following procedure: 4-(6-Acryloyloxyhexyloxy)benzylbrornide: To an ice-bath cooled solution of 5.0 g of 4-(6-acryloyloxyhexyloxy)benzylalcohol in 50 ml of methylenechloride was added dropwise a solution of 3.27 g of phosphorus tribromide in 10 ml of methylenechloride . After complete addition, the reaction mixture was stirred for further 15 min at about 5°C and then poured into 100 g of ice water. The organic layer was separated, diluted with 50 ml of methylenechloride, washed with half saturated NaCl solution (3 x 60 ml), dried under reduced pressure and concentrated to dryness to give 4.8 g of a yellowish oil mainly consisting of 4-(6- acryloyloxyhexyloxy)benzylbromide. This oil was used without further purification in the next reaction step. 4-(6-Acryloyloxyhexyloxy)benzylalcohol: A mixture consisting of 2.48 g of 4-hydroxybenzylalcohol, 5.64 g of 6-iodohexyl acrylate, and 2.76 g of potassium carbonate in 50 ml of DMF was stirred under nitrogen atmosphere for 3 h at 60°C. After being cooled to room temperature the reaction mixture was quenched with 100 ml 3N HC1 and extracted with diethylether (2 x 100 ml). The combined ether extracts were washed with saturated NaCl solution, dried over sodium sulphate and concentrated to dryness to give 5.3 g of nearly pure 4- (6-acryloyloxyhexyloxy)benzylalcohol as a beige heavy oil. EXAMPLE 4 Preparation of 1,4-di-N-[2-(4-(6-Methacryloyloxyhexyloxy)phenylcarbonyloxy)- benzyl]aminoanthraquinone: A mixture consisting of 4.3 g of 2-[4-(6-methacryloyloxyhexyloxy)- phenylcarbonyloxy]benzylbromide, 0.42 g of 1,4-diammoanthraquinone and 1.38 g of potassium carbonate in 20 ml of DMF was stirred under nitrogen atmosphere for 6 h at room temperature. The reaction mixture was then quenched with 100 ml 3N HC1 and extracted with ethylacetate (2 x 150 ml). The combined organic extracts were washed with saturated NaCl solution (100 ml), dried over sodium sulphate and concentrated to dryness to give a blue residue. Chrornatography on silica using 5% diethylether in methylenechloride gave 0.7 g of nearly pure l,4-di-N-[4-(6- acryloyloxyhexyloxy)benzyl]aminoanthraquinone as a blue crystalline material which was further recrystallised from 9/1 (v/v) ethanol / acetone; ?max. (CB 483): 611 nm. The starting material was synthesised according to the following procedure: 2-[4-(6-Methacryloyloxyhexyloxy)phenylcarbonyloxylbenzylbromide: To an ice-bath cooled solution of 5.0 g of 2-[4-(6-methacryloyloxyhexyloxy)- phenylcarbonyloxy]benzylbromide in 50 ml of methylenechloride was added dropwise a solution of 2.80 g of phosphorus tribromide in 10 ml of methylenecMoride After complete addition, the reaction mixture was stirred for further 15 min at about 5°C then poured into 100 g of ice water. The organic layer was separated off, diluted with 50 ml of methylenechloride, washed with half saturated NaCl solution (3 x 60 ml), dried over sodium sulphate and concentrated to dryness to give 4.3 g of a yellowish oily material mainly consisting of 2-[4-(6-methacryloyloxyhexyloxy)- phenylcarbonyloxy]benzylbromide. This oil was used without further purification in the next reaction step. 2-r4-(6-Methacryloyloxyhexyloxy)phenylcarbonyloxylbenzylalcohol: To an ice-cooled solution of 2.44 g of salysaldehyde , 6.14 g of 4-(6- methacryloyloxyhexyloxy)benzoic acid and 0.24 g of N,N-dimethylaminopyridine in 30 ml of methylenechloride was added dropwise a solution of 4.12 g of dicyclohexylcarbodiimide in 10 ml of methylenechloride . After complete addition the mixture was further stirred for 3 h at room temperature, then filtered and the solution concentrated to dryness. The obtained yellowish oily residue was dissolved in 30 ml of ethanol containing 0.5 ml of water and the so obtained solution was cooled at 0°C, followed by slow addition of 0.37 g of sodium borohydride. The mixture obtained after complete addition was stirred for 15 min at 0°C, and subsequently for 30 min at room temperature. The resulting mixture was then quenched by adding 100 ml of water followed by extraction with ether (2 x 150 ml). The combined ether extracts were washed with half saturated ammonium chloride solution, dried over sodium sulphate and concentrated to dryness to give an oily residue. Subsequent purification by simple filtration through a short silica-gel column using ether as the eluent gave 5.2 g of pure 2-[4-(6-methacryloyloxyhexyloxy)phenylcarbonyloxy]- benzylalcohol as a beige heavy oil. The following compound was synthesised using a similar method: 1.4-di-N-[2-(4-(6-Acryloyloxyhexyloxy)phenylcarbonyloxy)-5-nitrobenzyl]amino- anthraquinone: ?max. (CB 483): 639 nm EXAMPLE 5 Preparation of 4-(4-Acryloyloxybutyloxy)-3-methyl-4"-phenylazo-azobenzene: To a solution of 0.63 g of 4-hydroxy-3-methyl-4"-phenylazo-azobenzene, 1.05 g of triphenylphosphine and 0.58 g of 4-hydroxybutylacrylate in 10 ml THF, which was cooled to -30°C, was added dropwise a solution of 0.70 g of diethyl azodicarboxylate in 5 ml THF. After complete addition, the reaction mixture was stirred for further 45 min at room temperature, and then concentrated to dryness. The obtained yellow-red residue was purified by filtration on silica using methylenechloride as the eluent to give 0.65 gof pure yellow-orange crystalys; ?max. (CB 483): 395 nm. EXAMPLE 6 Preparation of 1-[4-(4-(dimethylamino)naphthylazo)phenylazo1-4-(6-acryloyloxy- hexyloxy)naphtalene: A mixture consisting of 0.44 g of l-[4-(4-(dimethylamino)naphthylazo)phenylazo]-4- hydroxy-naphtalene, 0.56 g of 6-iodohexyl acrylate, and 0.28 g of potassium carbonate in 10 ml of DMF was stirred under nitrogen atmosphere for 3 h at 60°C. After cooling to room temperature the reaction mixture was quenched with 100 ml 3N HC1 and the resulting precipitate was filtered off, washed with water (100 ml) and ethanol (50 ml) to give 0.5 g of pure l-[4-(4-(dimethylamino)naphthylazo)- phenylazo]-4-(6-acryloyloxyhexyloxy)naphtalene as a brownish powder; ?max. (CB 483): 504 nm. The starting material was synthesised according to the following procedure: l-[4-(4-(Dimethylamino)-naphthylazo)-phenylazol-4-hydroxy-naphtalene: 2.9 g of l-(4-amino-phenylazo)-4-(dimethylamino)naphtalene were dissolved in a mixture of 2.5 ml of HC1 37% and 5 ml of water. The obtained solution was cooled to 0°C, followed by dropwise addition of 0.69 g of sodium nitrite in 3 ml of water, while keeping the reaction temperature below 4°C. After complete addition, stirring was continued for 45 min at about 4°C and the obtained mixture was then added to an ice- cooled solution of 1.44 g of 1-naphtol in NaOH/water (1.1 g/11 ml, while keeping the reaction temperature below 5°C. After complete addition, the reaction mixture was further stirred for lh at about 5°C and then poured into 100 ml of water. The resulting brownish precipitate was filtered off, washed with water (100 ml) and methanol (50 ml). Crystallisation in methanol gave 3.3 g of the desired product. l-(4-Amino-phenylazo)-4-(dimethylamino)-naphtalene: A mixture of 15 g of l-(4-nitro-phenylazo)-4-(dimethylamino)naphtalene, 75 ml sodiumhydrogen sulphate nonahydrate (50% wt in water) and 80 ml of methanol was heated at reflux for 3h. The reaction mixture was then cooled to room temperature and poured into 300 ml of water. The brownish precipitate was filtered off, washed with water (200 ml) and cold methanol-water (100 ml/100 ml) to give 12 g of nearly pure 1 -(4-amino-phenylazo)-4-(dimethylamino)naphtalene as a brownish solid. l-(4-Nitro-phenylazo)-4-(dimethylamino)naphtalene: 6.91 g of 4-nitroaniline were dissolved in a mixture of 15 ml of HC1 37% and 40 ml of water. The obtained solution was cooled to 0°C, followed by dropwise addition of 3.45 g of sodium nitrite in 15 ml of water, while keeping the reaction temperature below 4°C. After complete addition, stirring was continued for 15 min at about 4°C and the resulting mixture was then added to an ice-cooled solution of 8.56 g of 1- (dimethylamino)naphatalene in 20 ml of acetic acid. The reaction mixture was stirred for 30 min, followed by dropwise addition of 18 g of a solution of potassium acetate in 30 ml of water, while keeping the reaction temperature below 5°C. After complete addition the reaction mixture was further stirred for lh at room temperature and then poured into 300 ml of water. The brownish precipitate was filtered off, washed with water (300 ml) and with methanol (100 ml) and crystallised from methanol to give i 5.3 g of the desired product. EXAMPLES 7-11 Preparation of dichroic mixtures: Five mixtures were prepared using the dichroic, polymerisable, blue antraquinone dye B1 and the red, polymerisable, azo dye Rl shown in Table 1 and the monomeric, crosslinkable liquid crystal components (LCPs) Monl to Mon5 shown in Table 2. Using these crosslinkable liquid crystal monomers and polymerisable dichroic dyes, supercoolable dichroic nematic mixtures MLCPI to MLCP5 were developed, allowing the preparation of LCP layers at room temperature. The composition ratios of the mixtures MLCPI to MLCPS were chosen as given in Table 3. In addition, a further 2 wt% of the photo-initiator IRGACURE369 (Ciba) was added to the above mixtures. The mixtures MLCPI to MLCP5 were used to produce oriented, dichroic liquid crystal samples on glass substrates as described below. Production of dichroic LCP layers: Five samples were prepared, whereby each single specimen comprised an alignment layer and a dichroic liquid crystal polymer layer. The alignment layers were manufactured using the linearly photo-polymerizable aligning (LPP) technique. The dichroic liquid crystal polymer layers were oriented by the adjacent LPP layers. The manufacturing processes of both layers are described in the following. For the production of an LPP orientation layer, suitable LPP materials are described for example in patent publications EP 0 611 786, WO 96/10049 and EP 0 763 552, and include cinnamic acid derivatives and ferulic acid derivatives. For the examples, the following LPP material was chosen: A 2 % solution of the LPP material in methylpropylketone (MPK) as a solvent was spin-coated at 2000 rpm for 60 seconds at room temperature (20°C). The layer was then dried for 5 to 10 minutes at 130 to 150°C on a hot stage. Subsequently, the layer was exposed to linearly polarised light from a mercury high-pressure lamp for 10 to 550 seconds (depending on the strength of the lamp and on the characteristics of LPP and dichroic LCP layers) at room temperature. The layer was then used as an orientation layer for a liquid crystal material comprising dichroic dyes. For the production of the dichroic LCP layers, the mixtures MLCPI to MLCP5 were dissolved in anisole to give a 20 wt% solution. These LCP mixtures, which include dichroic dyes, were then spin-coated at 800 rpm for 60 seconds on top of the photo- exposed LPP layers. The spin-coated dichroic LCP layers were then dried at 60°C for approximately 1 minute on a hot stage. For photo-initiated cross-linking of the liquid crystals and dye components, the layers were exposed to isotropic light from a xenon lamp for about 5 minutes (depending on the strength of the lamp) in an inert atmosphere. The procedure described above gave photo-aligned dichroic LCP layers on glass substrates leading to 5 different samples E1 to E5 derived from the 5 dichroic LCP mixtures MLCP1 to MLCP5. Order parameters of samples E1 to E5: The order parameter S of a dichroic dye is given by the following expression: S = D11-D1 / D11+2D1 wherein D11 and D1 are the optical densities of a dichroic dye in a liquid crystal measured for light polarisations parallel and perpendicular to the liquid crystal director. Table 4 shows the order parameters S of samples E1 to E5 as measured at the indicated wavelength. Table 4: All samples E1 to E5 were crosslinked successfully. The surfaces were completely dry and were more or less resistant against scratches. WE CLAIM: 1. A mesogenic, crosslinkable mixture, wherein at least one compound comprises more than one polymerisable group in its structure, and which mixture comprises at least one polymerisable liquid crystal comprising more than one polymerisable group, and at least one polymerisable dichroic dye selected from an anthraquinone of the formulae Vl-X: wherein one to four hydrogen atoms are substituted by the groups of B1 to B4 either at carbon or nitrogen atoms, with the provision that at most one of B1 to B4 is attached to the same nitrogen atom, and wherein B1 to B4 represent a group of substructure II wherein the broken line symbolises the linkage to said dichroic residue and wherein : A1, A2, A3 each independently represent an aromatic or alicyclic group, which is unsubstituted or substituted by fluorine chlorine, cyano, nitro, or a straight-chain or branched alkyl residue, which is unsubstituted, mono-substituted by cyano or halogeno, or poly-substituted by halogeno, having 1 to 18 carbon atoms, and wherein one or more of the non-adjacent CH2 groups may independently be replaced by Q, whereby Q represents -O-, -CO-, -CO-O-, -O-CO-, -Si(CH3)2-O-Si(CH3)2-, -NR2-, -NR2-CO-, -CO-NR2-, -NR2-CO-O-, -O-CO-NR2-, -NR2-CO-NR2-, -CH=CH-, -CDC-, -O-CO-O-, and R2 represents hydrogen or straight-chain or branched d-Cs alkyl, preferably straight-chain or branched C1-C3 alkyl; S1, S2 represent a single covalent bond or a spacer unit, such as a straight-chain or branched alkylene residue, which is unsubstituted, mono-substituted by cyano or halogeno, or poly-substituted by halogeno, having 1 to 24 carbon atoms, wherein one or more of the non-adjacent CH2 groups may independently be replaced by Q, wherein Q has the meaning given above; Z1, Z2 independently represent a single covalent bond or a spacer unit, such as a straight-chain or branched alkylene residue, which is unsubstituted, mono-substituted by cyano or halogeno, or poly-substituted by halogeno, having 1 to 8 carbon atoms, wherein one or more of the non-adjacent CH2 groups may independently be replaced by Q, -N=N- or -CR2=C-CO-, wherein Q and R2 have the meaning given above; P represents a polymerisable group; m1, m2, m3 independently are 0 or 1; and o is 0 or 1, whereby the sum of the symbols o in B1 to B4 is > 0, or at least one polymerisable dichroic dye selected from an azo dye of the formulae IV and V: R4-Ar1-N=N-Ar2-N=N-Ar3-B1 IV R4-Ar1-N=N-Ar2-N=N-Ar3-N=N-Ar4-B1 v wherein R4 represents hydrogen, fluoro, chloro, bromo, cyano, nitro, -NR2R3, a three- to seven-membered cyclic amino group, -CR2=CR3-NO2, -CR2=CR3-CN, -CR2=C(CN)2, or a straight chain or branched alkyl residue, which is unsubstituted, mono- or poly-substituted by fluorine having 1-18 carbon atoms, wherein one or more of the non-adjacent CH2 groups may independently be replaced by -O-, -CO-O-, -O-CO-, -NR2-CO-, -CO-NR2-, -NR2-CO-O-, -O-CO-NR2-, -CH=CH-, -CDC-, -O-CO-O-, wherein R2 and R3 independently represent hydrogen or lower alkyl; Ar1, Ar2, Ar3, Ar4 independently of each other are 1,4-phenylene, 1,4- or 1,5-naphthylene optionally substituted by fluorine, chlorine, hydroxy, -NR2R3 or by a straight chain or branched alkyl residue, which is unsubstituted, mono- or poly-substituted by fluorine having 1-12 carbon atoms, wherein one or more of the non-adjacent CH2 groups may independently be replaced by -O-, -CO-O-, -O-CO-, -NR2-CO-, -CO-NR2-, -NR2-CO-O-, -O-CO-NR2-, -CH=CH-, -CDC-, -O-CO-O-, wherein R2 and R3 independently represent hydrogen or lower alkyl; and wherein Ar1 is also a group of formula a) to c) wherein p is an integer of 1 to 3 and R4 of formulae IV and V is attached to the nitrogen atom; and B1 has the meaning given above. 2. A mesogenic, crosslinkable mixture as claimed in claim 1, wherein the aromatic group is a optionally substituted carbocyclic or heterocyclic group comprising five-, six- or ten-membered ring systems. 3. A mesogenic, crosslinkable mixture as claimed in claims 1 or 2, wherein the aromatic group is furane, phenyl, pyridine, pyrimidine, naphthalene or tetraline. 4. A mesogenic, crosslinkable mixture as claimed in any preceding claim, wherein the alicyclic group is a non-aromatic carbocyclic or heterocyclic ring system having 3 to 10 carbon atoms. 5. A mesogenic, crosslinkable mixture as claimed in any preceding claim, wherein the alicyclic group is cyclopropane, cyclobutane, cyclopentane, cyclopentene, cyclohexane, cyclohexene, cyclohexadiene or decaline. 6. A mesogenic, crosslinkable mixture as claimed in any of preceding claims, wherein the straight-chain or branched alkyl group is selected from the group comprising methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, cyclopentyl, hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, 3-methylpentyl, allyl, but-3-en-1-yl, pent-4-en-1-yl, hex-5-en-1-yl, propynyl, butynyl, pentynyl, methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy, terf-butoxy, pentyloxy, isopentyloxy, cyclopentyloxy, hexyloxy, cyclohexyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy, undecyloxy, dodecyloxy, 3-methylpentyloxy, allyloxy, but-3-enyloxy, pent-4-enyloxy, cylohexylmethoxy, cyclopentylmethoxy, methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, isopropoxycarbonyl, butoxycarbonyl, isobutoxycarbonyl, sec-butoxycarbonyl, tert-butoxy- carbonyl, pentyloxycarbonyl, isopentyloxycarbonyl, cyclopentyloxycarbonyl, hexyloxycarbonyl, cyclohexyloxycarbonyl, octyloxycarbonyl, nonyloxy- carbonyl, decyloxycarbonyl, undecyloxycarbonyl, dodecyloxycarbonyl, 3-methylpentyloxycarbonyl, allyloxycarbonyl, but-3-enyloxycarbonyl, pent-4-enyloxycarbonyl, cylohexylmethoxycarbonyl, cyclopentylmethoxy- carbonyl, acetoxy, ethylcarbonyloxy, propylcarbonyloxy, isopropyl- carbonyloxy, butylcarbonyloxy, isobutylcarbonyloxy, sec-butylcarbonyloxy, tert-butylcarbonyloxy, pentylcarbonyloxy, isopentylcarbonyloxy, cyclopentyl- carbonyloxy, hexylcarbonyloxy, cyclohexylcarbonyloxy, octylcarbonyloxy, nonylcarbonyloxy, decylcarbonyloxy, undecylcarbonyloxy, dodecyl- carbonyloxy, 3-methylpentylcarbonyloxy, but-3-enyloxy, pent-4-enyloxy, acetyl, ethylcarbonyl, propylcarbonyl, isopropylcarbonyl, butylcarbonyl, isobutylcarbonyl, sec-butylcarbonyl, pentylcarbonyl, isopentylcarbonyl, cyclohexylcarbonyl, octylcarbonyl, nonylcarbonyl, decylcarbonyl, undecyl- carbonyl, dodecylcarbonyl, methoxyacetoxy, 1-methoxy-2-propoxy, 3-methoxy-1-propoxy, 2-methoxyethoxy, 2-isopropoxyethoxy, 1-ethoxy-3-pentyloxy, 3-butynyloxy, 4-pentynyloxy, 5-chloropentynyl, 4-pentynecarbonyloxy, 6-propyloxyhexyl, 6-propyloxyhexyloxy, 2-fluoroethyl, trifluoromethyl, 2,2,2-trifluoroethyl, 1H,1H-pentadecafluoro- octyl, 1H,1H,7H-dodecafluoroheptyl, 2-(perfluorooctyl)ethyl, 2-(perfluoro- butyl)ethyl, 2-(perfluorohexyl)ethyl, 2-(perfluorodecyl)ethyl, perfluoropropyl, perfluorobutyl, perfluoroheptyl, perfluorooctyl, perfluorononyl. 1-fluoropropoxy, 1-fluoropentyloxy, 2-fluoropropoxy, 2,2-difluoropropoxy, 3-fluoropropoxy, 3,3-difluoropropoxy, 3,3,3-trifluoropropoxy, and trifluoro- methoxy. 7. A mesogenic, crosslinkable mixture as claimed in any of preceding claims, wherein A1, A2 and A3 independently of each other are unsubstituted, saturated five- or six-membered alicyclic rings or six-membered aromatic rings, optionally substituted by fluorine or chlorine or nitro or by a straight chain or branched alkyl residue, which is unsubstituted, mono- or poly- substituted by fluorine having 1-12 carbon atoms, wherein one or more of the non-adjacent CH2 groups may independently be replaced by -O-, -CO-O-, -O-CO-, -NR2-CO-, -CO-NR2-, -NR2-CO-O-, -O-CO-NR2-, -CH=CH-, -CDC-, -O-CO-O-, wherein R2 represents hydrogen or lower alkyl. 8. A mesogenic, crosslinkable mixture as claimed in any preceding claims, wherein A1, A2 and A3 are a unsubstituted cyclopentane-1,3-diyl, unsubstituted cyclohexane-1,4-diyl, or 1,4-phenylene, which is unsubstituted, mono- or poly-substituted by fluorine or chlorine or a straight- chain or branched alkyl residue, which is unsubstituted, mono- or poly- substituted by fluorine having 1-12 carbon atoms, wherein one or more of the non-adjacent CH2 groups may independently be replaced by -O-, -CO-O-, -O-CO-, -CH=CH-, -C=C-. 9. A mesogenic, crosslinkable mixture as claimed in any preceding claims, wherein S1 and S2 are selected from the group comprising -(CH2)r-, -(CH2)r-O-, -(CH2)r-CO-, -(CH2)r-CO-O-, -(CH2)r-O-CO-, -(CH2) r-CO-NR2-, -(CH2)r-NR2-CO-, -(CH2)r-NR2-, -(CH2)r-O-(CH2)s-, -(CH2) r-CO-O-(CH2)s-, -(CH2)r-O-CO-(CH2)s-, -(CH2)r-NR2-CO-(CH2)s-, -(CH2)r-NR2-CO-O-(CH2)s-, -(CH2)r-O-(CH2)s-O-, -(CH2)r-CO-O-(CH2) s-O-, -(CH2)r-O-CO-(CH2)s-O-, -(CH2)r-NR2-CO-(CH2)s-O-, -(CH2) r-NR2-CO-O-(CH2)s-O-, -O-(CH2)r-, -CO-O-(CH2)r-, -O-CO-(CH2)r-, -NR2-CO-(CH2)r-, -CO-NR2-(CH2)r, -NR2-(CH2)r-, -O-(CH2)r-CO-O-, -O-(CH2)r-O-CP-, -O-(CH2)r-CO-NR2-, -O-(CH2)r-NR2-, -O-(CH2)r-O-, -O-(CH2)r-NR2-CO-, -NR2-(CH2)r-CO-O-, -NR2-(CH2)r-O-, -NR2-(CH2) r-NR2-, -NR2-(CH2)r-O-CO-, -CO-NR2-(CH2)r-O-, -CO-NR2-(CH2)r-NR2-, -CO-NR2-(CH2)r-O-CO-, -O-CO-(CH2)r-CO-, -O-CO-(CH2)r-O-, -O-CO-(CH2)-NR2-, -O-CO-(CH2)r-CO-O-, -O-CO-(CH2)r-CO-NR2-, -O-CO-(CH2)r-NR2-CO-, -O-(CH2)r-O-(CH2)s-, -O-(CH2)r-CO-O-(CH2)s-, -O-(CH2)r-NR2-CO-(CH2)s-, -O-(CH2)r-NR2-CO-O-(CH2)s-, -O-(CH2) r-C0-0-(CH2)s-O-,-O-(CH2)r-O-(CH2)s-O-,-O-(CH2)r-NR2-CO-(CH2)s-O-, -O-(CH2)r-NR2-CO-O-(CH2)s-O-, -CO-O-(CH2)r-O-(CH2)s-, -CO-O-(CH2) r-O-(CH2)s-O-, wherein r and s are each an integer from 1 to 20, the sum of r + s ? 21, wherein R2 represents hydrogen or lower alkyl, and which are attached to the dichroic residue and the polymerisable group, respectively, such that heteroatoms are not directly linked to each other. 10. A mesogenic, crosslinkable mixture according to in any of preceding claims, wherein S1 is selected from the group comprising -(CH2)r-, -(CH2)r-O-, -(CH2)r-CO-O-, -(CH2)r-O-CO-, -(CH2)r-CO-NH-, -(CH2)r-NH-CO-, -(CH2) r-NH-CO-(CH2)s-, -(CH2)r-NH-CO-O-(CH2)s-, -(CH2)r-O-(CH2)s-O-, -(CH2) r-NH-CO-(CH2)s-O-, -(CH2)r-NH-CO-O-(CH2)s-O-, -O-(CH2)r-, -CO-O-(CH2)r-, -CO-NH-(CH2)r-, -O-CO-(CH2)r-, -O-CO-(CH2)r-CO-O-, -O-(CH2)r-O-CO-, -O-(CH2)r-CO-NH-, -O-(CH2)r-NH-CO-, -CO-O-(CH2) r-O-, -CO-NH-(CH2)r-O-, -O-(CH2)r-O-, -O-(CH2)r-NH-CO-(CH2)s-, -O-(CH2)r-O-(CH2)s-O-, -O-CO-(CH2)r-O-(CH2)s-O-, -CO-O-(CH2) r-O-(CH2)s-O-, -O-(CH2)r-NH-CO-(CH2)s-O-, -O-CO-(CH2)r-NH-CO-(CH2) s-O-, wherein r and s are each an integer from 1 to 16, the sum of r + s ? 18 and which are attached to the dichroic residue and the polymerisable group, respectively, such that heteroatoms are not directly linked to each other. 11. A mesogenic, crosslinkable mixture as claimed in any of preceding claims, wherein S1 selected from the group comprising -(CH2)r-, -(CH2)r-O-, -(CH2)r-CO-O-, -(CH2)r-O-CO-, -(CH2)r-O-(CH2)s-O-, -(CH2) r-NH-CO-O-(CH2)s-O-, and if attached to a carbon atom of the dichroic residue also -O-(CH2)r-, -CO-O-(CH2)r-, -O-CO-(CH2)r-, -O-CO-(CH2) r-CO-O-, -O-(CH2)r-O-CO-, -CO-O-(CH2)r-O-, -O-(CH2)r-O-, -O-(CH2) r-O-(CH2)s-O-, -O-CO-(CH2)r-O-(CH2)s-O-, -CO-O-(CH2)r-O-(CH2)s-O-, wherein r and s are each an integer from 1 to 12, the sum of r + s ? 14, and which are attached to the dichroic residue and the polymerisable group, respectively, such that heteroatoms are not directly linked to each other. 12. A mesogenic, crosslinkable mixture as claimed in any of preceding claims, wherein S1 is selected from the group comprising 1,2-ethylene, 1,3-propylene, 1,4-butylene, 1,5-pentylene, 1,6-hexylene, 1,7-heptylene, 1,8-octylene, 1,9-nonylene, 1,10-decylene, 1,11-undecylene, 1,12-dodecylene, 3-methyl-1,4-butylene, 3-propyleneoxy, 3-propyleneoxycarbonyl, 2-ethylenecarbonyloxy, 4-butyleneoxy, 4-butyleneoxycarbonyl, 3-propylenecarbonyloxy, 5-pentyleneoxy, 5-pentyleneoxycarbonyl, 4-butylenecarbonyloxy, 6-hexyleneoxy, 6-hexyleneoxycarbonyl, 5-pentylenecarbonyloxy, 7-heptyleneoxy, 7-heptyleneoxycarbonyl, 6-hexylenecarbonyloxy, 8-octyleneoxy, 8-octyleneoxycarbonyl, 7-heptylenecarbonyloxy, 9-nonyleneoxy, 9-nonyleneoxycarbonyl, 8-octylenecarbonyloxy, 10-decyleneoxy, 10-decyleneoxycarbonyl, 9-nonylenecarbonyloxy, 11-undecyleneoxy, 11-undecyleneoxycarbonyl, 10-decylenecarbonyloxy, 12-dodecyleneoxy, 12-dodecyleneoxycarbonyl, 11-undecylenecarbonyloxy, 3-propyleneimno- carbonyl, 4-butyleneiminocarbonyl, 5-pentyleneiminocarbonyl, 6-hexyleneiminocarbonyl, 7-heptyleneiminocarbonyl, 8-octyleneimino- carbonyl, 9-nonyleneiminocarbonyl, 10-decyleneiminocarbonyl, 11-undecyleneiminocarbonyl, 12-dodecyleneiminocarbonyl, 2-ethylene- carbonylimino, 3-propylenecarbonylimino, 4-butylenecarbonylimino, 5-pentylenecarbonylimino, 6-hexylenecarbonylimino, 7-heptylenecarbonyl- imino, 8-octylenecarbonylimino, 9-nonylenecarbonylimino, 10-decylene- carbonylimino, 11-undecylenecarbonylimino, 6-(3-propyleneiminocarbonyl- oxy)hexyl, 6-(3-propyleneoxy)hexyl, 6-(3-propyleneoxy)hexyloxy, 6-(3-propyleneiminocarbonyloxy)hexyloxy, 6-(3-propyleneiminocarbonyl) hexyl, 6-(3-propyleneiminocarbonyl)hexyloxy, 1,2-ethylenedioxy, 1,3-propylenedioxy, 1,4-butylenedioxy, 1,5-pentylenedioxy, 1,6-hexylene- dioxy, 1,7-heptylenedioxy, 1,8-octylenedioxy, 1,9-nonylenedioxy, 1,10-decylenedioxy, 1,11-undecylenedioxy, and 1,12-dodecylenedioxy. 13. A mesogenic, crosslinkable mixture as claimed in any of preceding claims, wherein Z1 and Z2 groups are a single covalent bond or a straight-chain or branched alkylene residue, which is unsubstituted, mono-substituted or poly-substituted by fluoro, having 1 to 8 carbon atoms, wherein one or more of the non-adjacent CH2 groups may independently be replaced by -O-, -CO-, -CO-O-, -O-CO-, -NR2-CO-, -CO-NR2-, -NR2-CO-O-, -O-CO-NR2-, -CH=CH-, -CDC-, -O-CO-O-, -N=N-, -CR2=C-CO-, wherein R2 represents hydrogen or lower alkyl. 14. A mesogenic, crosslinkable mixture as claimed in any of preceding claims, wherein Z1 and Z2 groups are a single covalent bond or a straight-chain or branched alkylene residue, having 1 to 6 carbon atoms, wherein one or more of the non-adjacent CH2 groups may independently be replaced by -O-, -CO-O-, -O-CO-, -CH=CH-, -CDC-, -O-CO-O-, -N=N-, -CR2=C-CO-, wherein R2 represents hydrogen or lower alkyl. 15. A mesogenic, crosslinkable mixture as claimed in any of preceding claims, wherein Z1 and Z2 groups are a single covalent bond or a straight-chain or branched alkylene residue, having 1 to 4 carbon atoms, wherein one or two of the non-adjacent CH2 groups may independently be replaced by -O-, -CO-O-, -O-CO-, -N=N-. 16. A mesogenic, crosslinkable mixture as claimed in any of preceding claims, wherein the polymerisable groups P are selected from the group of CH2=CW-, CH2=CW-C00-, CH2=CH-CO-NH-, CH2=C(Ph)-CO-NH-, CH2=CH-O-, CH2=CH-OOC-, Ph-CH=CH-, CH2=CH-Ph-, CH2=CH-Ph-O-, R3-Ph-CH=CH-COO-, R3-OOC-CH=CH-Ph-O-, N-maleinimidyl, wherein W is hydrogen, chloro or methyl, R3 is lower alkyl or lower alkoxy, Ph- is phenyl, and -Ph- is 1,4-phenylene. 17. A mesogenic, crosslinkable mixture as claimed in any of preceding claims, wherein the polymerisable groups P are CH2=CW-, CH2=CW-COO-, CH2=CH-O- wherein W is hydrogen or methyl. 18. A mesogenic, crosslinkable mixture as claimed in any preceding claims, wherein the number of rings in substructure II expressed by m1 + m2 + m3 is ? 2. 19. A mesogenic, crosslinkable mixture as claimed in any of preceding claims, wherein at least one of the LCP components comprises more than one 20. A mesogenic, crosslinkable mixture as claimed in any of preceding claims, further comprising isotropic compounds comprising two or more polymerisable groups. 21. A mesogenic, crosslinkable mixture as claimed in any of preceding claims further comprising additives. 22. A mesogenic, crosslinkable mixture as claimed in any of preceding claims, comprising one to four dichroic dyes of formulae IV, V, VI, VII, VIII, IX, X and at least two polymerisable liquid crystals comprising each two polymerisable groups. 23. A mesogenic, crosslinkable mixture as claimed in any of preceding claims, wherein the total content of dichroic dyes is from 0.1 to 50%wt. 24. A mesogenic, crosslinkable mixture as claimed in any of preceding claims, wherein the total content of dichroic dyes is from 0.5 to 30%wt. 25. A mesogenic, crosslinkable mixture as claimed in any of preceding claims, wherein the total content the dichroic dyes is from 0.5 to 20%wt. 26. A mesogenic, crosslinkable mixture as claimed in claim 1, wherein R4 represents hydrogen, chloro, cyano, nitro, -NR2R3, 1-piperidyl- 1-pyrrolidyl or a straight chain or branched alkyl residue, which is unsubstituted, having 1-12 carbon atoms, wherein one or two of the non-adjacent CH2 groups may independently be replaced by -O-, -CO-O-, -O-CO-, -CH=CH-, wherein R2 and R3 independently represent hydrogen or lower alkyl. 27. A mesogenic, crosslinkable mixture as claimed in claim 26, wherein Ar1 to Ar4 IV and V, independently of each other are 1,4-phenylene or 1,4- naphthylene optionally substituted by chlorine, hydroxy, -NR2R3 or by a straight chain or branched alkyl residue, which is unsubstituted, having 1-12 carbon atoms, wherein one or two of the non-adjacent CH2 groups may independently be replaced by -O-, -CO-O-, -O-CO-, -CH=CH-, wherein R2 and R3 independently represent hydrogen or lower alkyl; and wherein Ar1 additionally is a group of formula a) to c). 28. A mesogenic, crosslinkable mixture as claimed in any of claims 1 to 27, wherein the dichroic dye of formula IV comprises 0 or 1 1,4-naphtylene unit. 29. A mesogenic, crosslinkable mixture as claimed in any of claims 1 to 27, wherein the dichroic dye of formula V comprises 0, 1 or 2 1,4-naphtylene units. 30. A mesogenic, crosslinkable mixture as claimed in claim 1, wherein the dichroic dye is an anthraquinone of the formulae VI to X, comprising having one or two of the groups B1 to B4. 31. A mesogenic, crosslinkable mixture as claimed in any of claims 1 or 30, wherein the dichroic dye is an anthraquinone of the formulae VI, VII or X. 32. Liquid crystalline polymer film formed from a mixture as claimed in any of claims 1 to 31, by polymerisation. 33. Liquid crystalline polymer film as claimed in claim 32, wherein the film is coated with further layers. 34. Process of preparing a liquid crystalline polymer film as claimed in claim 32 or 33, on a substrate comprising the steps of (i) preparing a solution of a mixture according to claims 1 to 38, (ii) applying said solution to a support, (iii) evaporating the solvent to obtain a film, (iv) polymerising said film using UV light to give a cross-linked dichroic liquid crystal film, and (v) optionally coating said cross-linked dichroic liquid crystal film with other layers. 35. Process as claimed in claim 34, wherein the substrate is a transparent substrate comprising an orientation layer. 36. Process as claimed in claim 35, wherein the transparent substrate is glass or plastic. 37. Process as claimed in claim 35 or 36, wherein the orientation layer is rubbed polyimide or polyamide. 38. Process as claimed in claim 35 or 36, wherein the orientation layer comprises a photo-orientable material. 39. Multilayer system comprising two or more liquid crystalline polymer layers, wherein at least one of the liquid crystalline polymer layers is a dichroic liquid crystalline polymer layer formed from a mixture as claimed in any of claims 1 to 31 by polymerisation. 40. Multilayer system as claimed in claim 39, wherein said layers are covered by at least one other functional layer. 41. Liquid crystalline polymer films made out of the mixture, as claimed in any of claims 1 to 31. 42. Electro-optical or optical component or device or security device comprising a dichroic liquid crystalline polymer film formed from a mixture, as claimed in claims 1 to 31. A mesogenic, crosslinkable mixture comprising at least one polymerisable liquid crystal and at least one polymerisable dichroic dye of the general formula (I) wherein A represents a dichroic residue exhibiting at least partial absorption in the visible region >400 nm; n1, n2, n3, n4 signifies 0 or 1 whereby the sum of nl, n2, n3, n4 is >0, and B1 to B4 represent a group of substructure II wherein the broken line symbolises the linkage to said dichroic residue.

Full Text

MESOGENIC, CROSSLINKABLE MIXTURE, LIQUID CRYSTALLINE POLYMER
FILM MADE OF SAID MIXTURE, AND PROCESS OF PREPARING SAID FILM
The present invention relates to mesogenic, crosslinkable mixture, liquid crystalline
polymer film made of said mixture, and process of preparing said film, and pertains to a
new mixture of crosslinkable liquid crystals and polymerisable dichroic dyes and their
use in the construction of unstructured and structured polarisers.
Optical polarisers (hereinafter also called polarising films, polarisation films or
polariser films) play a crucial role in the functioning principle of many optical or
electro-optical devices, such as Liquid Crystal Devices, modem Security Elements,
and the like. Furthermore, optical polarisers are also used in many instruments or
devices, for example in different kinds of measuring instruments, dashboards or
sunglasses, where stray light and undesired reflections have to be eliminated to
improve visibility. Such polarising films usually comprise stretched polymer films
such as, for example, polyvinyl alcohol (PVA), a dichroic absorber and other optional
layers. Dichroic absorbers usually are iodine or dichroic dyes which are absorbed on
or dissolved in the polymer film.
US 5,707,544 describes liquid crystals characterised by a molecular architecture,
wherein a chromophore is laterally attached to a polymerisable mesogenic core. Such
compounds and liquid crystalline mixtures containing these are described to be useful
mainly for non-linear optic devices or colour filters.
Yet, a disadvantage of the most widespread polariser films based on iodine absorbers
is their limited stability against humidity, heat and light. Polariser films based on
dichroic dyes have a tendency to lose efficiency during time due to diffusion
processes or inhomogeneities caused by partial crystallisation. A further drawback is
the migration of dichroic dyes to adjacent layers if such systems are designed for use
in multilayer systems as e.g. described in EP-A-06390S4.. Thus, there is clearly a
need for a concept whereby all or at least some of the above disadvantages may be
avoided..

Applicants have now found that certain mixtures comprising liquid crystals and
dichroic dyes may be able to overcome the disadvantages described hereinabove.
Thus, in a first aspect the present invention provides a mesogenic, crosslinkable mixture,
wherein at least one compound comprises more than one polymerisable group in its structure,
and which mixture comprises at least one polymerisable liquid crystal and at least one
polymerisable dichroic dye selected from an azo dye, an anthraquinone, a benzoquinone, a
perylene, an azulene or a merocyanine of the general formula I:

wherein
A represents a dichroic residue exhibiting at least partial absorption in
the visible region > 400 nm;
n1, n2, n3, n4 signify 0 or 1, whereby the sum of n1, n2, n3 and n4 is >0, and
B1 to B4 represent a group of substructure II

wherein the broken line symbolises the linkage to said dichroic residue and
wherein :

A1, A2, A3 each independently represent an aromatic or alicyclic group, which
is unsubstituted or substituted by fluorine, chlorine, cyano, nitro,
or a straight-chain or branched alkyl residue, which is
unsubstituted, mono-substituted by cyano or halogeno, or
poly-substituted by halogeno, having 1 to 18 carbon atoms, and
wherein one or more of the non-adjacent CH2 groups may
independently be replaced by Q, whereby Q represents -O-, -CO-,
-CO-O-, -O-CO-, -Si(CH3)2-O-Si(CH3)2-, -NR2-, -NR2-CO-,
-CO-NR2-, -NR2-CO-O-, -O-CO-NR2-, -NR2-CO-NR2-,
-CH=CH-, -OC-, -O-CO-O-, and R2 represents hydrogen or
straight-chain or branched C1-C6 alkyl, preferably straight-chain
or branched C1-C3 alkyl;
S1, S2 represent a single covalent bond or a spacer unit, such as a
straight-chain or branched alkylene residue, which is
unsubstituted, mono-substituted by cyano or halogeno, or
poly-substituted by halogeno, having 1 to 24 carbon atoms,
wherein one or more of the non-adjacent CH2 groups may
independently be replaced by Q, wherein Q has the meaning given
above;
Z1, Z2 independently represent a single covalent bond or a spacer unit,
such as a straight-chain or branched alkylene residue, which is
unsubstituted, mono-substituted by cyano or halogeno, or
poly-substituted by halogeno, having 1 to 8 carbon atoms, wherein
one or more of the non-adjacent CH2 groups may independently be
replaced by Q, -N=N- or -CR2=C-CO-, wherein Q and R2 have the
meaning given above;
P represents a polymerisable group;
ml, m2, m3 independently are 0 or 1; and
0 is 0 or 1, whereby the sum of the symbols 0 in Bl to B4 is > 0.

In a further aspect the invention also provides the use of said mesogenic crosslinkable
mixtures for the production of dichroic crosslinked films as well as their use in the
construction of unstructured and structured optical elements and multi-layer systems
as for example, for colour filters, polarisers and for me construction of security
devices.
These new polymerisable dichroic mixtures show good homogeneous alignment and
upon crosslinking do not exhibit inhomogeneities or changes of the dichroitic ratio
due to relaxation, diffusion or micro crystallisation processes over time.
The term "crosslinkable mixture" refers to a mixture comprising at least one
compound that comprises more than one polymerisable group in its structure.
The term "dichroic residue" refers to a dichroic dye exhibiting positive or negative
dichroism structurally reduced to the pure chromophore systems.
It is to be understood that the term "aromatic" comprises optionally substituted carbocyclic
and heterocyclic groups comprising five-, six- or ten-membered ring systems, such as
furane, phenyl, pyridine, pyrimidine, naphthalene, or tetraline units.
It is to be understood that the term "alycyclic" comprises non-aromatic carbocyclic or
heterocyclic ring systems having 3 to 10 carbon atoms, such as cyclopropane,
cyclobutane, cyclopentane, cyclopentene, cyclohexane, cyclohexene, cyclohexadiene
and decaline.
It is to be understood that the phrase "cyclic, straight-chain or branched aikyl group, which
is optionally substituted by a single cyano group or by one or more halogen atoms,
and in which one or more of the non-adjacent -CH2- groups may be optionally
replaced by a group Q" comprises groups selected from the group comprising methyl,
ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, terr-butyl, pentyl, isopentyl,
cyclopentyl, hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl,
3-merhylpentyl, allyl, but-3-en-l-yl, pent-4-en-l-yl, hex-5-an-l-yl, propynyl, butynyl,
pentynyl, rnethoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy,
tert-butoxy, pentyloxy, isopentyloxy, cyclopentyloxy, hexyloxy, cyclohexyloxy,

heptyloxy, octyloxy, nonyloxy, decyloxy, undecyloxy, dodecyloxy,
3-methylpentyloxy, allyloxy, but-3-enyloxy, pent-4-enyloxy, cylohexylmethoxy,
cyclopentylmethoxy, methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl,
isopropoxycarbonyl, butoxycarbonyl, isobutoxycarbonyl, sec-butoxycarbonyl,
tert-butoxycarbonyl, pentyloxycarbonyl, isopentyloxycarbonyl, cyclopentyloxy-
carbonyl, hexyloxycarbonyl, cyclohexyloxycarbonyl, octyloxycarbonyl, nonyloxy-
carbonyl, decyloxycarbonyl, undecyloxycarbonyl, dodecyloxycarbonyl,
3-methylpentyloxycarbonyl, allyloxycarbonyl, but-3-enyloxycarbonyl, pent-4-enyl-
oxycarbonyl, cylohexylmethoxycarbonyl, cyclopentylmethoxycarbonyl, acetoxy,
ethylcarbonyloxy, propylcarbonyloxy, isopropylcarbonyloxy, butylcarbonyloxy,
isobutylcarbonyloxy, sec-butylcarbonyloxy, tert-butylcarbonyloxy, pentyl-
carbonyloxy, isopentylcarbonyloxy, cyclopentylcarbonyloxy, hexylcarbonyloxy,
cyclohexylcarbonyloxy, octylcarbonyloxy, nonylcarbonyloxy, decylcarbonyloxy,
undecylcarbonyloxy, dodecylcarbonyloxy, 3-methylpentylcarbonyloxy,
but-3-enyloxy, pent-4-enyloxy, acetyl, ethylcarbonyl, propylcarbonyl, isopropyl-
carbonyl, butylcarbonyl, isobutylcarbonyl, sec-butylcarbonyl, pentylcarbonyl,
isopentylcarbonyl, cyclohexylcarbonyl, octylcarbonyl, nonylcarbonyl, decylcarbonyl,
undecylcarbonyl, dodecylcarbonyl, methoxyacetoxy, 1-methoxy-2-propoxy,
3-methoxy-l-propoxy, 2-methoxyethoxy, 2-isopropoxyethoxy, 1-ethoxy-3-pentyloxy,
3-butynyloxy, 4-pentynyloxy, 5-chloropentynyl, 4-peatynecarbonyloxy, 6-propyloxy-
hexyl, 6-propyloxyhcxyloxy, 2-fluoroethyl, trifluoromethyl, 2,2,2-trifluoroethyl.
1H, 1H-pentadecafluorooctyl, 1H, lH,7H-dodecafluoroheptyl, 2-(perfluorooctyl)ethyl,
2-(perfluorobutyl)ethyl, 2-(perfluorohexyl)ethyl, 2-(perfluorodecyl)ethyl, perfluoro-
propyl, perfluorobutyl, perfluoroheptyl, perfluorooctyl, perfluorononyl.
1-fluoropropoxy, 1-fluoropentyloxy, 2-fluoropropoxy, 2,2-difluoropropoxy,
3-fluoropropoxy, 3,3-difluoropropoxy, 3,3,3-trifluoropropoxy, and trifluoromethoxy.
It is to be understood that the term "lower alkyl" comprises straight chain and branched
hydrocarbon radicals having 1 to 6 carbon atoms, preferably 1 to 3 carbon atoms.
Methyl, ethyl, propyl and isopropyl groups are especially preferred.

Dichroic dyes, of which the dichroic residues A are derived fr are described in the
literature, e.g. in Molecular Crystals, Liquid Crystals 150A, (1987). In a preferred
embodiment the dichroic dyes of the present invention include azo dyes,
anthraquinones, benzoquinones, perylenes, azulenes, and merocyanines. Particularly
preferred dichroic dyes of the present invention include dyes comprising azo- or
anthraquinone residues.
The sum of substituents B attached to a dichroic residue A expressed by (n1 + n2 -N3
- n4) is preferably ? 3, more preferably ? 2.
Preferred rings A1, A2 and A3 independently of each other are unsubstituted,
saturated five- or six-membered alicyclic rings or six-membered aromatic rings,
optionally substituted by fluorine or chlorine or nitro or by a straight chain or
branched alkyl residue, which is unsubstituted, mono- or poly-substituted by fluorine
having 1-12 carbon atoms, wherein one or more of the non-adjacent CH2 groups may
independently be replaced by -O-, -CO-O-, -O-CO-, -NR2-CO-, -CO-NR2-,
-NR2-CO-O-, -O-CO-NR2-, -CH=CH-, -C=C-, -O-CO-O-, wherein R2 represents
hydrogen or lower alkyl.
Particularly preferred rings A1, A2 and A3 include unsubstituted cyclopentane-1,3-
diyl, unsubstituted cyclohexane-l,4-diyl, or 1,4-phenylene, which is unsubstituted,
mono- or poly-substituted by fluorine or chlorine or a straight-chain or branched alkyl
residue, which is unsubstituted, mono- or poly-substituted by fluorine having 1-12
carbon atoms, wherein one or more of the non-adjacent CH2 groups may
independently be replaced by -O-, -CO-O-, -O-CO-, -CH=CH-, -C=C-.
Preferred "spacer units" S1 and S2 of the present invention comprise ? single bond, or a
straight-chain or branched alkylene grouping, such as -(CH2)r-, and also -(CH2)r-O-,
-(CH2)r-CO-, -(CH2)r-CO-O-, -(CH2)rO-CO-, -(CH2)r-CO-NR2-, -(CH2)r-NR2-CO-,
-(CH2)r-NR2-, -(CH2)r-O-(CH2)s-, -(CH2)rCO-O-(CH2)s-, -(CH2)rO-CO-(CH2)s-,
-(CH2)r-NR2-CO-(CH2)s-, -(CH2)r-XR2-CO-O-(CH2)s-, -(CH2)r-O-(CH2)s-O-,

-(CH2)r-CO-O-(CH2)s-O-, -(CH2)r-O-CO-(CH2)s-O-, -(CH2)rNR2-CO-(CH2)s-O-,
-(CH2)r-XR2-CO-O-(CH2)s-O-, -O-(CH2)r, -CO-O-(CH2)r, -O-CO-(CH2)r,
-XR2-CO-(CH2)r, -CO-NR2-(CH2)r, -NR2-(CH2)r-, -O-(CH2)r-CO-O-,
-O-(CH2)r-O-CO-, -O-(CH2)r-CO-NR2-, -O-(CH2)r-NR2-, -O-(CH2)r-O-,
-O-(CH:)r-NR2-CO-, -NR2-(CH2)r-CO-O-, -NR2-(CH2)r-O-, -NR2-(CH2)r-NR2-,
-NR2-(CH2)rO-CO-, -CO-NR2-(CH2)rO-, -CO-NR2-(CH2)r-NR2-,
-CO-NR2-(CH2)r-O-CO-, -O-CO-(CH2)r-CO-, -O-CO-(CH2)r-O-,
-O-CO-(CH2)r-NR2-, -O-CO-(CH2)r-CO-O-, -O-CO-(CH2)r-CO-NR2-,
-O-CO-(CH2)r-NR2-CO-, -O-(CH2)r-O-(CH2)s-, -O-(CH2)r-CO-O-(CH2)s-,
-O-(CH2)r-NR2-CO-(CH2)s-, -O-(CH2)r-NR2-CO-O-(CH2)s-,
-O-(CH2)r-CO-O-(CH2)s-O-, -O-(CH2)r-O-(CH2)s-O-,
-O-(CH2)r-NR2-CO-(CH2)s-O-, -O-(CH2)rNR2-CO-O-(CH2)s-O-,
-CO-O-(CH2)r-O-(CH2)s-, -CO-O-(CH2)r-O-(CH2)s-O-5 wherein r and s are each an
integer from 1 to 20, the sum of r ÷ s ? 21, wherein R2 represents hydrogen or lower
alkyl, and which are attached to the dichroic residue and the polymerisable group,
respectively, such that heteroatoms are not directly linked to each other.
Particularly preferred "spacer units" S1 comprise a single bond, a straight-chain
alkylene grouping, such as -(CH2)r, and also -(CH2)r-O-, -(CH2)r-CO-O-,
-(CH2)r-O-CO-, -(CH2)r-CO-NH-5 -(CH2)rNH-CO-, -(CH2)r-NH-CO-(CH2)s-,
-(CH2)r-NH-CO-O-(CH2)s-; -(CH2)rO-(CH2)s-O-, -(CH2)rNH-CO-(CH2)s-O-,
-(CH2)r-NH-CO-O-(CH2)s-O-, -O-(CH2)r, -CO-O-(CH2)r, -CO-NH-(CH2)r,
-O-CO-(CH2)r, -O-CO-(CH2)r-CO-O-, -O-(CH2)r-O-CO-, -O-(CH2)rCO-NH-,
-O-(CH2)r-NH-CO-, -CO-O-(CH2)rO-, -CO-NH-(CH2)rO-, -O-(CH2)r-O-,
-O-(CH2)r-NH-CO-(CH2)s-, -O-(CH2)r-O-(CH2)s-O-, -O-CO-(CH2)r-O-(CH2)s-O-,
-CO-O-(CH2)r-O-(CH2)s-O-, -O-(CH2)rNH-CO-(CH2)s-O-,
-O-CO-("H2)r-NH-CO-(CH2)s-O-, wherein r and s are each an integer from 1 to 16,
the sum of r - s ? 18 and which are attached to the dichroic residue and the
polymerisable group, respectively, such that heteroatoms are not directly linked to
each other.

Most preferred "spacer units" of S1 comprise single bond, a straight-chain alkylene
grouping represented by -(CH2)r-, and also -(CH2)r-O-, -(CH2)r-CO-O-,
-(CH2)r-O-CO-, -(CH2)r-O-(CH2)s-O-, -(CH2)r-NH-CO-O-(CH2)s-O-, and if attached
to a carbon atom of the dichroic residue also -O-(CH2)r-, -CO-O-(CH2)r-,
-O-CO-(CH2)r-, -O-CO-(CH2)r-CO-O-, -O-(CH2)r-O-CO-, -CO-O-(CH2)r-O-,
-O-(CH2)r-O-, -O-(CH2)r-O-(CH2)s-O-, -O-CO-(CH2)r-O-(CH2)s-O-,
-CO-O-(CH2)r-O-(CH2)s-O-, wherein r and s are each an integer from 1 to 12, the
sum of r + s ? 14, and which are attached to the dichroic residue and the
polymerisable group, respectively, such that heteroatoms are not directly linked to
each other.
Examples of preferred "spacer units" S1 comprise 1,2-ethylene, 1,3-propylene,
1,4-butylene, 1,5-pentylene, 1,6-hexylene, 1,7-heptylene, 1,8-octylene, 1,9-nonylene,
1,10-decylene, 1,11-undecylene, 1,12-dodecylene, 3-methyl-1,4-butylene,
3-propyleneoxy, 3-propyleneoxycarbonyl, 2-ethylenecarbonyloxy, 4-butyleneoxy,
4-butyleneoxycarbonyl, 3-propylenecarbonyloxy, 5-pentyleneoxy,
5-pentyleneoxycarbonyl, 4-butylenecarbonyloxy, 6-hexyleneoxy, 6-hexyleneoxyc-
arbonyl, 5-pentylenecarbonyloxy, 7-heptyleneoxy, 7-heptyleneoxycarbonyl,
6-hexylenecarbonyloxy, 8-octyleneoxy, 8-octyleneoxycarbonyl, 7-heptylenecarbonyl-
oxy, 9-nonyleneoxy, 9-nonyleneoxycarbonyl, 8-octylenecarbonyloxy, 10-decylene-
oxy, 10-decyleneoxycarbonyl, 9-nonylenecarbonyloxy, 11-undecyleneoxy,
11-undecyleneoxycarbonyl, 10-decylenecarbonyloxy, 12-dodecyleneoxy,
12-dodecyleneoxycarbonyl, 11-undecylenecarbonyloxy, 3-propyleneiminocarbonyl,
4-butyleneiminocarbonyl, 5-pentyleneiminocarbonyl, 6-hexyleneiminocarbonyl,
7-heptyleneiminocarbonyl, 8-octyleneiminocarbonyl, 9-nonyleneiminocarbonyl,
10-decyleneiminocarbonyl, 11-undecyleneiminocarbonyl, 12-dodecyleneimino-
carbonyl, 2-ethylenecarbonylimino, 3-propylenecarbonylimino, 4-butylenecarbonyl-
imino, 5-pentylenecarbonylimino, 6-hexylenecarbonylimino, 7-heptylenecarbonyl-
imino, 8-octylenecarbonylimino, 9-nonylenecarbonylimino, 10-decylenecarbonyl-

imino, 11-undecylenecarbonylimino, 6-(3-propyleneiminocarbonyloxy)hexyl,
6-(3-propyleneoxy)hexyl, 6-(3-propyleneoxy)hexyloxy, 6-(3-propyleneimino-
carbonyloxy)hexyloxy, 6-(3-propyleneiminocarbonyl)hexyl, 6-(3-propyleneimino-
carbonyl)hexyloxy, 1,2-ethylenedioxy, 1,3-propylenedioxy, 1,4-butylenedioxy,
1,5-pentylenedioxy, 1,6-hexylenedioxy, 1,7-heptylenedioxy, l,S-octylenedioxy,
1,9-nonylenedioxy, 1,10-decylenedioxy, 1,11-undecylenedioxy, and 1,12-dodecylene-
dioxy.
Preferred Z1 and Z2 groups comprise . a single covalent bond or a straight-chain or
branched alkylene residue, which is unsubstituted, mono-substituted or
poly-substituted by fluoro, having 1 to 8 carbon atoms, wherein one or more of the
non-adjacent CH2 groups may independently be replaced by -O-, -CO-, -CO-O-,
-O-CO-, -NR2-CO-, -CO-NR2-, -NR2-CO-O-, -O-CO-NR2-, -CH=CH-, -C=C-,
-O-CO-O-, -N=N-, -CR2=C-CO-, wherein R2 represents hydrogen or lower alkyl.
Panicularly preferred Z1 and Z2 groups comprise a single covalent bond or a
straight-chain or branched alkylene residue, having 1 to 6 carbon atoms, wherein one
or more of the non-adjacent CH2 groups may independently be replaced by -O-,
-CO-O-, -O-CO-, -CH=CH-, -OC-, -O-CO-O-, -N=N-, -CR2=C-CO-, wherein R2
represents hydrogen or lower alkyl.
Most preferred Z1 and Z2 groups comprise a single covalent bond or a straight-chain or
branched alkylene residue, having 1 to 4 carbon atoms, wherein one or two of the
non-adjacent CH2 groups may independently be replaced by -O-, -CO-O-, -O-CO-,
-N=N-.
Polymerisable groups P are preferably selected from the formulae CH2=CW-.
CH2=CW-COO-, CH2=CH-CO-NH-, CH2=C(Ph)-CO-NH-, CH2=CH-O-,
CH2=CH-OOC-, Ph-CH=CH-, CH2=CH-Ph-, CH2=CH-Ph-O-,
R3-Ph-CH=CH-COO-, R3-OOC-CH=CH-Ph-O-, N-maleinimidyl, wherein W is
hydrogen, chloro or methyl, R3 is lower alkyl or lower alkoxy, Ph- is phenyl and
-Ph- is 1,4-phenylene.

Particularly preferred groups P comprise CH2=CW-, CH2=CW-COO-, CH2=CH-O-
wherein W is hydrogen or methyl.
The number of rings in substructure II expressed by m1 + m2 + m3 is preferably ? 2.
Polymerisable liquid crystals (LCP) which are present in the inventive mixtures are
well known to the skilled person e.g. from EP 0331233 , WO 95/24454,
US 5,567,349, US 5,650,534, WO 00/04110, WO 00/07975, WO 00/48985,
WO 00/55110 and WO 00/63154. For adjustment of mesomorphic properties and
suppression of crystallisation, mixtures of two or more LCP components may
generally be used. At least one of the LCP components may optionally comprise more
than one polymerisable group in the chemical structure in order to achieve
crosslinking. As an alternative or to improve crosslinking abilities the addition of
isotropic compounds comprising two or more polymerisab-e groups, so called
crosslinkers, may also be possible. Furthermore well known additives such as, e.g.
phenol derivatives for stabilisation and photoinitiators such as, e.g. Irgacure® may
also be present in the inventive mixture.
The number of dyes of formula I present in the mixture may depend mainly on the
spectral working range of the polariser and on the solubility of the dyes. Coloured
polariscrs, which are absorbing in a selective spectral range may preferably be
achieved by the presence of one or two, black polarisers, selectively absorbing in the
whole visible range by the presence of three or more dyes in the mixture.
Preferred mixtures of the invention consequently comprise at least one dichroic dye
according to the general formula I and at least two polymerisable liquid crystals,
wherein at least one of them comprises more than one polymerisable group and
optionally additives, such as crosslinkers, stabilisers and photoinitiators.

Particularly preferred are mixtures comprising one to four dichroic dyes of formula I
and at least two polymerisable liquid crystals comprising each two polymerisable
groups and optionally additives such as crosslinkers, stabilisers and photoinitiators.
The total content of dichroic dyes of formula I in the inventive mixture may depend
on different factors such as solubility in the LCP host, influence on the mesomorphic
properties (e.g. depression of clearing point) and absorption ability (extinction) of the
dyes involved. Preferred dye concentrations may be in the range of 0.1 to 50%wt,
more preferably from 0.5 to 30%wt, most preferably from 0.5 to 20%wt.
Dichroic dyes from the class of azo dyes suitable for the inventive mixtures may
preferably be selected from the groups according to general formulae III - V:
R4-Ar1-N=N-Ar2-B1 III
R4-Ar1-N=N-Ar2-N=N-Ar3-B1 IV
R4-Ar1-N=N-Ar-2-N=N-Ar3-N=N-Ar4-B1 V
wherein
R4 represents hydrogen, fluoro, chloro, bromo, cyano, nitro, -NR2R3,
a three- to seven-membered cyclic amino group, -CR2=CR3-NO2,
-CR2=CR3-CN, -CR2=C(CN)2, or a straight chain or branched
alkyl residue, which is unsubstituted, mono- or poly-substituted by
fluorine having 1-18 carbon atoms, wherein one or more of the
non-adjacent CH2 groups may independently be replaced by -O-,
-CO-O-, -O-CO-, -NR2-CO-, -CO-NR2-, -NR2-CO-O-,
-O-CO-NR2-, -CH=CH-, -OC-, -O-CO-O-, wherein R2 and R3
independently represent hydrogen or lower alkyl;
Ar1, Ar2, Ar3, Ar4 independently of each other are 1,4-phenylene, 1,4- or 1,5-
naphthylene optionally substituted by fluorine, chlorine, hydroxy,
-NR2R3 or by a straight chain or branched alkyl residue, which is

unsubstituted, mono- or poly-substituted by fluorine having 1-12
carbon atoms, wherein one or more of the non-adjacent CH2
groups may independently be replaced by -O-, -CO-O-, -O-CO-,
-NR2-CO-, -CO-NR2-, -NR2-CO-0-, -O-CO-NR2-, -CH=CH-,
-C=C-, -O-CO-O-, wherein R2 and R3 independently represent
hydrogen or lower alkyl; and
wherein Ar1 is also a group of formula a) to c)

wherein p is an integer of 1 to 3 and R4 of formulae III to V is
attached to the nitrogen atom; and
B1 has the meaning given above.
The dyes of formula III to V are new and represent a further aspect of the present
invention.
Preferred dyes of formula III to V include those wherein R4 represents hydrogen,
chloro, cyano, nitro, -NR2R3, 1-piperidyl- 1-pyrrolidyl or a straight chain or branched
alkyl residue, which is unsubstituted, having 1-12 carbon atoms, wherein one or two
of the non-adjacent CH2 groups may independently be replaced by -O-, -CO-O-,
-O-CO-, -CH=CH-, wherein R2 and R3 independently represent hydrogen or lower
alkyl;
Preferred dyes of formula III to V include also those where Ar1 to Ar4 independently
of each other are 1,4-phenylene or 1,4-naphthylene optionally substituted by chlorine,
hydroxy, -NR2R3 or by a straight chain or branched alkyl residue, which is
unsubstituted, having 1-12 carbon atoms, wherein one or two of the non-adjacent CH2

groups may independently be replaced by -O-, -CO-O-, -O-CO-, -CH=CH-, wherein
R2 and R3 independently represent hydrogen or lower alkyl;
and wherein Ar1 additionally is a group of formula a) to c).
Preferred azo dyes of formula III may comprise no 1,4-naphtylene units, preferred azo
dyes of formula IV at most one 1,4-naphtylene unit, and preferred azo dyes of
formula V not more than two 1,4-naphtylene units.
Dichroic dyes from the class of anthraquinones suitable for the mixtures of the present
invention may preferably be selected from the groups according to formulae VI-X:

wherein one to four hydrogen atoms are substituted by the groups of B1 to B4 either
at carbon or nitrogen atoms, and wherein B1 to B4 have the meaning given above,
with the provision that at most one of B1 to B4 is attached to the same nitrogen atom.
Such anthraquinone dyes are new and represent a further aspect of the present
invention.
Preferred anthraquinone dyes may comprise one or two of the groups B1 to B4.
Further preferred anthraquinone dyes may be represented by the formulae VI, VII or
X.

The dichroic azo dyes of formula III to V and the dichroic anthraquinone dyes based
on formulae VI to X may readily be prepared using methods well known to the person
skilled in the art, such as those documented in Houben-Weyl, Methoden der
Organischen Chemie, Thieme-Verlag, Stuttgart or in Molecular Crystals and Liquid
Crystals Vol. 150A, 1987.
The polymerisable liquid crystalline mixtures according to the present invention may
further be formed into liquid crystalline polymer films (LCP films). Thus, in a further
aspect the invention provides dichroic films formed from mixtures according to the
present invention. Such LCP films may readily be prepared by UV or thermal
polymerisation of the mixtures of the present invention. A film comprising a mixture
according to the present invention is formed on a substrate, for example, by first
preparing a solution of a mixture, which is subsequently applied to a support by
different coating techniques, such as spincoating, miniscuscoating, wirecoating,
slotcoating, offsetprinting, flexoprinting, gravureprinting. After evaporation of the
solvent the obtained film is polymerised using UV light to give a cross-linked
dichroic liquid crystal film of preferably 0.5 to 5 µm thickness. If required such films
may further be coated with other layers, such as, e.g. protective layers for protection
against oxygen, UV-irradiation or mechanical stress. Such films may be used in the
manufacture of devices such as polarisers or optical filters.
Examples of substrates used in the preparation of dichroic LCP films may include
transparent substrates, such as glass or plastic including an orientation layer, which is
able to induce a uniform orientation to the mixture. Such orientation layers may
include rubbed polyimide, or polyamide or preferably layers of photo-orientable
materials. A well-suited kind of photo-orientable orientation layers are Linearly
Photopolymerisable Polymers (LPP), also sometimes referred to as Photooriented
Polymer Networks (PPN). Backgrounds and manufacturing of such orientation layers
are disclosed in, for example, US 5,389,698, US 5,838,407, US 5,602,661,
US 6,160,597, US 6,144,428, all of the applicant. Using LPP layers, segments (pixels)
of locally varying orientation may be formed. Thus, not only uniformly aligned
dichroic LCP layers but also structured complex orientation patterns within the

dichroic LCP layers may be produced. Furthermore multilayer systems formed from
stacks of alternating LPP and LCP layers, wherein at least one of the LCP layers is a
dichroic LCP layer are feasible. Such layers or stacks of layers may additionally be
covered by other well known functional layers, such as, e.g. protecting layers against
oxygen or humidity or layers for protection against ultraviolet radiation.
Recently it has been shown, e.g. in WO 99/64924, that photo-orienting materials like
LPPs may also be able to orient liquid crystals, such as LCPs, if they are admixed to
the mixture to be oriented prior to illumination with polarised light. In this way,
orientation layers and LCP layers need not be formed separately. Thus, an analogous
preparation of a dichroic LCP film using an inventive mixture, which in addition
contains a photo-orientable material, may also be possible.
The dichroic mixtures and films of the present invention may be used to prepare
electro-optical and optical devices including security devices. A further aspect of the
invention therefore provides an electro-optical or optical component or a security
device comprising a dichroic liquid crystalline polymer film formed from a mixture of
the invention. Examples of optical or electro-optical components may include
structured or unstructured optical filters, polarisers or elements of security devices.
The following non-limiting examples further describe the present invention.
Variations on these falling within the scope of the invention will be apparent to a
person skilled in the art.
EXAMPLE 1
Preparation of 4-(6-Acryloyloxyhexyloxy)phenyl-1,4-diarminoanthraquinone-2-
carboxylate:

To a mixture of 0.16 g of 4-(6-acryloyloxyhexyloxy)phenyl-l-amino-4-
nitroanthraquinone-2-carboxylate, 16 ml of dimethylformamide, and 2 ml of water
was added at room temperature 0.465 g of iron-III-chloride and 0.281 g of zinc
powder. The reduction was allowed to proceed for 15 h under continuous stirring.
Then the reaction mixture was extracted with methylenechloride, the organic phases
were collected and washed with water, dried over sodium sulphate, filtered and
concentrated to dryness. Chromatography of the residue on silica using 5%
ethylacetate in toluene and subsequent crystallisation from ethyl acetate/hexane (1:2)
gave 0.12 g of blue crystals; ?max. (CH2Cl2): 624 nm (? = 10"100), 590 nm (? =
10"133).
The starting material was prepared in accordance with the following procedure:
Preparation of 4-(6-Acryloyloxyhexyloxy)phenyl-1-amino-4-nitroanthraquinone-2-
carboxylate:
To a mixture of 0.43 g of 4-(6-hydroxyhexyloxy)phenyl-l-amino-4-
nitroanthraquinone-2-carboxylate, 20 ml of methylenechloride, 0.015 g of N,N-
dimethylaminopyridine, and 0.117 ml of acrylic acid were added dropwise 0.246 g of
dicyclohexylcarbodiimide in 10 ml of methylenechloride. The mixture was stirred for
15 h at room temperature, then filtered and the solution concentrated to dryness.
Chromatography of the residue on silica, using 2.5% ethylacetate in toluene and
crystallisation from ethylacetate/hexane (2:1) gave 0.16 g of red crystals; ?max.
(CH2Cl2): 482 nm (? = 7,647).
Preparation of 4-(6-Hydroxyhexyloxy)phenyl-1-ar-O-4-mtroanthraquinone-2-
carboxylate:
A mixture of 0.9 g of 4-(6-(2-tetrahydropyranyl)oxyhexyloxy)phenyl-l-amino-4-
nitroanthraquinone-2-carboxylate, 40 ml of methanol and 20 ml of 2N hydrochloric
acid was stirred for 15 h at room temperature. The reaction mixture was then

extracted with ether and the organic phase was washed with sodium bicarbonate and
water and dried over sodium sulphate. Subsequent filtration and concentration to
dryness gave 0.43 g of a red solid.
Preparation_____of_____4-( 6-( 2-Tetrahvdropyranyl)oxyhexyloxy)phenyl-1-amino-4-
nitroanthraquinone-2-carboxylate:
To a mixture of 0.8 g of l-amino-4-nitroanthraquinone-2-carboxylic acid
(commercially available from Bayer), 0.904 g of 4-(6-(2-
tetrahydropyranyl)oxyhexyloxy)phenol, 30 ml of methylenechloride and 0.044 g of
N,N-dimethylaminopyridine was added dropwise at 15°C 0.74 g of
dicyclohexylcarbodiimide in 15 ml of methylenechloride. The reaction mixture was
then stirred for 15 h at room temperature. Subsequent filtration and concentration to
dryness gave 0.9 g of the product as a red solid.
Preparation of 4-(6-(2-Tetrahydropyranyl)oxyhexyloxy)phenol:
A mixture of 10 g of 2-(6-chlorohexyloxy)tetrahydropyrane, 25 g of hydroquinone, 31
g of potassiumcarbonate, 0.752 g of potassiumiodide and 250 ml of dimethylsulfoxide
was allowed to react for 4 days at 80°C. Subsequently, the reaction mixture was
cooled to room temperature and after addition of water extracted with ether. The
organic phase was then dried over sodium sulphate, filtered and concentrated to
dryness. Chromatography on silica with 10% ethylacetate in toluene gave llg of
product as a yellowish oil.
Preparation of 2-(6-Chlorohexyloxy)tetrahydropyrane:
To a mixture of 15 g of 6-chlorohexanol, 100 ml of methylenechloride and 0.2 g of p-
toluenesulphonic acid were added dropwise 12 g of diliydropyrane in 40 ml of
methylenechloride. The reaction mixture was stirred for 15 h at room temperature and
then distributed between ether and saturated sodium bicarbonate solution. The ether
phase was washed with water, dried over sodium sulphate, filtered and concentrated

to dryness. Chromatography of the residue on silica using hexane/ether (3:1) gave 21
g of the product as a colourless oil.
The following compounds were synthesised using a similar method as described
above:
4-(4-(6-Acryloyloxyhexyloxy)phenyloxycarbonyl)phenyl-1-4-diaminoanthraquinone-
2-carboxylate :

?max. (CH2C12): 625 nm (? = 12"995), 599 nm (? = 12,900).
6-(4-(4-(6-Acryloyloxyhexyloxy)phenyloxycarbonyl)phenyloxy)hexyl-l,4-
diaminoanthraquinone-2-carboxylate:

?max. (CH2C12): 624 nm (? = 11"306), 590 nm (? = 11"404).
6-Acryloyloxyhexyloxy -1,4-diaminoanthraquinone-2-carboxylate:

?max. (CH2C12): 624 nm (? = 11"921), 591 nm (? = 11"789).

EXAMPLE 2
Preparation of (4-heptylphenyl)- 4-acrylamido-1-aminoanthraquinone-2-carboxylate:

To a stirred solution of 0.91 g of (4-heptylphenyl)-l,4-diaminoanthraquinone-2-
carboxylate (preparation analogous to example 1) in 80 ml of methylenechloride,
cooled to 0°C was added dropwise (over a period of 30 min) a solution of 0.36 g of
acryloylchloride in 20 ml of methylenechloride . After stirring for 1 h at 0 °C and
30 min at room temperature, DMAP was added and stirring was continued for further
60 min. The reaction mixture was then concentrated to half its volume and passed
through a silica gel column using methylenechloride as the eluent. The afforded violet
solid was further recrystallised from ethanol/methylenechloride 9/1 (v/v) to give
0.88 g (4-heptylphenyl)-4-acrylamido-l-aminoanthraquinone-2-carboxylate as violet
crystals; ?max. (CB 483): 572 nm.
EXAMPLE 3
Preparation of 1,4-di-N-[4-(6-Acryloyloxyhexyloxy)benzyl1aminoanthraquinone:

A mixture consisting of 4.8 g of 4-(6-acryloyloxyhexyloxy)benzylbromide , 0.48 g of
1,4-diaminoanthraquinone and 1.38 g of potassium carbonate in 20 ml of DMF was
stirred under nitrogen atmosphere for 6 h at room temperature. The reaction mixture
was then quenched with 100 ml 3 N HC1 and extracted with ethylacetate (2 x 150
ml). The combined organic extracts were washed with saturated NaCl solution (100
ml), dried over sodium sulphate and concentrated to dryness to give a blue residue.

Chromatography on silica using 5% diethylether with methylenechloride gave 0.9 g of
pure l,4-di-N-[4-(6-acryloyloxyhexyloxy)benzyl]ammoanthraquinone as blue
crystals; ?max. (CB 483): 604 mn.
The starting material was synthesised according to the following procedure:
4-(6-Acryloyloxyhexyloxy)benzylbrornide:
To an ice-bath cooled solution of 5.0 g of 4-(6-acryloyloxyhexyloxy)benzylalcohol in
50 ml of methylenechloride was added dropwise a solution of 3.27 g of phosphorus
tribromide in 10 ml of methylenechloride . After complete addition, the reaction
mixture was stirred for further 15 min at about 5°C and then poured into 100 g of ice
water. The organic layer was separated, diluted with 50 ml of methylenechloride,
washed with half saturated NaCl solution (3 x 60 ml), dried under reduced pressure
and concentrated to dryness to give 4.8 g of a yellowish oil mainly consisting of 4-(6-
acryloyloxyhexyloxy)benzylbromide. This oil was used without further purification in
the next reaction step.
4-(6-Acryloyloxyhexyloxy)benzylalcohol:
A mixture consisting of 2.48 g of 4-hydroxybenzylalcohol, 5.64 g of 6-iodohexyl
acrylate, and 2.76 g of potassium carbonate in 50 ml of DMF was stirred under
nitrogen atmosphere for 3 h at 60°C. After being cooled to room temperature the
reaction mixture was quenched with 100 ml 3N HC1 and extracted with diethylether
(2 x 100 ml). The combined ether extracts were washed with saturated NaCl solution,
dried over sodium sulphate and concentrated to dryness to give 5.3 g of nearly pure 4-
(6-acryloyloxyhexyloxy)benzylalcohol as a beige heavy oil.

EXAMPLE 4
Preparation of 1,4-di-N-[2-(4-(6-Methacryloyloxyhexyloxy)phenylcarbonyloxy)-
benzyl]aminoanthraquinone:

A mixture consisting of 4.3 g of 2-[4-(6-methacryloyloxyhexyloxy)-
phenylcarbonyloxy]benzylbromide, 0.42 g of 1,4-diammoanthraquinone and 1.38 g of
potassium carbonate in 20 ml of DMF was stirred under nitrogen atmosphere for 6 h
at room temperature. The reaction mixture was then quenched with 100 ml 3N HC1
and extracted with ethylacetate (2 x 150 ml). The combined organic extracts were
washed with saturated NaCl solution (100 ml), dried over sodium sulphate and
concentrated to dryness to give a blue residue. Chrornatography on silica using 5%
diethylether in methylenechloride gave 0.7 g of nearly pure l,4-di-N-[4-(6-
acryloyloxyhexyloxy)benzyl]aminoanthraquinone as a blue crystalline material which
was further recrystallised from 9/1 (v/v) ethanol / acetone; ?max. (CB 483): 611 nm.
The starting material was synthesised according to the following procedure:
2-[4-(6-Methacryloyloxyhexyloxy)phenylcarbonyloxylbenzylbromide:
To an ice-bath cooled solution of 5.0 g of 2-[4-(6-methacryloyloxyhexyloxy)-
phenylcarbonyloxy]benzylbromide in 50 ml of methylenechloride was added
dropwise a solution of 2.80 g of phosphorus tribromide in 10 ml of methylenecMoride
After complete addition, the reaction mixture was stirred for further 15 min at about
5°C then poured into 100 g of ice water. The organic layer was separated off, diluted
with 50 ml of methylenechloride, washed with half saturated NaCl solution (3 x 60

ml), dried over sodium sulphate and concentrated to dryness to give 4.3 g of a
yellowish oily material mainly consisting of 2-[4-(6-methacryloyloxyhexyloxy)-
phenylcarbonyloxy]benzylbromide. This oil was used without further purification in
the next reaction step.
2-r4-(6-Methacryloyloxyhexyloxy)phenylcarbonyloxylbenzylalcohol:
To an ice-cooled solution of 2.44 g of salysaldehyde , 6.14 g of 4-(6-
methacryloyloxyhexyloxy)benzoic acid and 0.24 g of N,N-dimethylaminopyridine in
30 ml of methylenechloride was added dropwise a solution of 4.12 g of
dicyclohexylcarbodiimide in 10 ml of methylenechloride . After complete addition
the mixture was further stirred for 3 h at room temperature, then filtered and the
solution concentrated to dryness. The obtained yellowish oily residue was dissolved in
30 ml of ethanol containing 0.5 ml of water and the so obtained solution was cooled at
0°C, followed by slow addition of 0.37 g of sodium borohydride. The mixture
obtained after complete addition was stirred for 15 min at 0°C, and subsequently for
30 min at room temperature. The resulting mixture was then quenched by adding
100 ml of water followed by extraction with ether (2 x 150 ml). The combined ether
extracts were washed with half saturated ammonium chloride solution, dried over
sodium sulphate and concentrated to dryness to give an oily residue. Subsequent
purification by simple filtration through a short silica-gel column using ether as the
eluent gave 5.2 g of pure 2-[4-(6-methacryloyloxyhexyloxy)phenylcarbonyloxy]-
benzylalcohol as a beige heavy oil.
The following compound was synthesised using a similar method:

1.4-di-N-[2-(4-(6-Acryloyloxyhexyloxy)phenylcarbonyloxy)-5-nitrobenzyl]amino-
anthraquinone:

?max. (CB 483): 639 nm
EXAMPLE 5
Preparation of 4-(4-Acryloyloxybutyloxy)-3-methyl-4"-phenylazo-azobenzene:

To a solution of 0.63 g of 4-hydroxy-3-methyl-4"-phenylazo-azobenzene, 1.05 g of
triphenylphosphine and 0.58 g of 4-hydroxybutylacrylate in 10 ml THF, which was
cooled to -30°C, was added dropwise a solution of 0.70 g of diethyl azodicarboxylate
in 5 ml THF. After complete addition, the reaction mixture was stirred for further 45
min at room temperature, and then concentrated to dryness. The obtained yellow-red
residue was purified by filtration on silica using methylenechloride as the eluent to
give 0.65 gof pure yellow-orange crystalys; ?max. (CB 483): 395 nm.

EXAMPLE 6
Preparation of 1-[4-(4-(dimethylamino)naphthylazo)phenylazo1-4-(6-acryloyloxy-
hexyloxy)naphtalene:

A mixture consisting of 0.44 g of l-[4-(4-(dimethylamino)naphthylazo)phenylazo]-4-
hydroxy-naphtalene, 0.56 g of 6-iodohexyl acrylate, and 0.28 g of potassium
carbonate in 10 ml of DMF was stirred under nitrogen atmosphere for 3 h at 60°C.
After cooling to room temperature the reaction mixture was quenched with 100 ml 3N
HC1 and the resulting precipitate was filtered off, washed with water (100 ml) and
ethanol (50 ml) to give 0.5 g of pure l-[4-(4-(dimethylamino)naphthylazo)-
phenylazo]-4-(6-acryloyloxyhexyloxy)naphtalene as a brownish powder; ?max. (CB
483): 504 nm.
The starting material was synthesised according to the following procedure:
l-[4-(4-(Dimethylamino)-naphthylazo)-phenylazol-4-hydroxy-naphtalene:
2.9 g of l-(4-amino-phenylazo)-4-(dimethylamino)naphtalene were dissolved in a
mixture of 2.5 ml of HC1 37% and 5 ml of water. The obtained solution was cooled to
0°C, followed by dropwise addition of 0.69 g of sodium nitrite in 3 ml of water, while
keeping the reaction temperature below 4°C. After complete addition, stirring was
continued for 45 min at about 4°C and the obtained mixture was then added to an ice-
cooled solution of 1.44 g of 1-naphtol in NaOH/water (1.1 g/11 ml, while keeping the
reaction temperature below 5°C. After complete addition, the reaction mixture was
further stirred for lh at about 5°C and then poured into 100 ml of water. The resulting
brownish precipitate was filtered off, washed with water (100 ml) and methanol (50
ml). Crystallisation in methanol gave 3.3 g of the desired product.

l-(4-Amino-phenylazo)-4-(dimethylamino)-naphtalene:
A mixture of 15 g of l-(4-nitro-phenylazo)-4-(dimethylamino)naphtalene, 75 ml
sodiumhydrogen sulphate nonahydrate (50% wt in water) and 80 ml of methanol was
heated at reflux for 3h. The reaction mixture was then cooled to room temperature and
poured into 300 ml of water. The brownish precipitate was filtered off, washed with
water (200 ml) and cold methanol-water (100 ml/100 ml) to give 12 g of nearly pure
1 -(4-amino-phenylazo)-4-(dimethylamino)naphtalene as a brownish solid.
l-(4-Nitro-phenylazo)-4-(dimethylamino)naphtalene:
6.91 g of 4-nitroaniline were dissolved in a mixture of 15 ml of HC1 37% and 40 ml
of water. The obtained solution was cooled to 0°C, followed by dropwise addition of
3.45 g of sodium nitrite in 15 ml of water, while keeping the reaction temperature
below 4°C. After complete addition, stirring was continued for 15 min at about 4°C
and the resulting mixture was then added to an ice-cooled solution of 8.56 g of 1-
(dimethylamino)naphatalene in 20 ml of acetic acid. The reaction mixture was stirred
for 30 min, followed by dropwise addition of 18 g of a solution of potassium acetate
in 30 ml of water, while keeping the reaction temperature below 5°C. After complete
addition the reaction mixture was further stirred for lh at room temperature and then
poured into 300 ml of water. The brownish precipitate was filtered off, washed with
water (300 ml) and with methanol (100 ml) and crystallised from methanol to give
i 5.3 g of the desired product.
EXAMPLES 7-11
Preparation of dichroic mixtures:
Five mixtures were prepared using the dichroic, polymerisable, blue antraquinone dye
B1 and the red, polymerisable, azo dye Rl shown in Table 1 and the monomeric,
crosslinkable liquid crystal components (LCPs) Monl to Mon5 shown in Table 2.

Using these crosslinkable liquid crystal monomers and polymerisable dichroic dyes,
supercoolable dichroic nematic mixtures MLCPI to MLCP5 were developed, allowing
the preparation of LCP layers at room temperature. The composition ratios of the
mixtures MLCPI to MLCPS were chosen as given in Table 3.

In addition, a further 2 wt% of the photo-initiator IRGACURE369 (Ciba) was added
to the above mixtures.
The mixtures MLCPI to MLCP5 were used to produce oriented, dichroic liquid crystal
samples on glass substrates as described below.
Production of dichroic LCP layers:
Five samples were prepared, whereby each single specimen comprised an alignment
layer and a dichroic liquid crystal polymer layer. The alignment layers were
manufactured using the linearly photo-polymerizable aligning (LPP) technique. The
dichroic liquid crystal polymer layers were oriented by the adjacent LPP layers. The
manufacturing processes of both layers are described in the following.
For the production of an LPP orientation layer, suitable LPP materials are described
for example in patent publications EP 0 611 786, WO 96/10049 and EP 0 763 552,
and include cinnamic acid derivatives and ferulic acid derivatives. For the examples,
the following LPP material was chosen:

A 2 % solution of the LPP material in methylpropylketone (MPK) as a solvent was
spin-coated at 2000 rpm for 60 seconds at room temperature (20°C). The layer was
then dried for 5 to 10 minutes at 130 to 150°C on a hot stage. Subsequently, the layer
was exposed to linearly polarised light from a mercury high-pressure lamp for 10 to
550 seconds (depending on the strength of the lamp and on the characteristics of LPP
and dichroic LCP layers) at room temperature. The layer was then used as an
orientation layer for a liquid crystal material comprising dichroic dyes.
For the production of the dichroic LCP layers, the mixtures MLCPI to MLCP5 were
dissolved in anisole to give a 20 wt% solution. These LCP mixtures, which include
dichroic dyes, were then spin-coated at 800 rpm for 60 seconds on top of the photo-
exposed LPP layers. The spin-coated dichroic LCP layers were then dried at 60°C for
approximately 1 minute on a hot stage. For photo-initiated cross-linking of the liquid
crystals and dye components, the layers were exposed to isotropic light from a xenon
lamp for about 5 minutes (depending on the strength of the lamp) in an inert
atmosphere.
The procedure described above gave photo-aligned dichroic LCP layers on glass
substrates leading to 5 different samples E1 to E5 derived from the 5 dichroic LCP
mixtures MLCP1 to MLCP5.
Order parameters of samples E1 to E5:
The order parameter S of a dichroic dye is given by the following expression:
S = D11-D1 / D11+2D1
wherein D11 and D1 are the optical densities of a dichroic dye in a liquid crystal
measured for light polarisations parallel and perpendicular to the liquid crystal
director.
Table 4 shows the order parameters S of samples E1 to E5 as measured at the
indicated wavelength.

Table 4:

All samples E1 to E5 were crosslinked successfully. The surfaces were completely dry
and were more or less resistant against scratches.

WE CLAIM:
1. A mesogenic, crosslinkable mixture, wherein at least one compound
comprises more than one polymerisable group in its structure, and which
mixture comprises at least one polymerisable liquid crystal comprising more
than one polymerisable group, and at least one polymerisable dichroic dye
selected from an anthraquinone of the formulae Vl-X:

wherein
one to four hydrogen atoms are substituted by the groups of B1 to B4
either at
carbon or nitrogen atoms, with the provision that at most one of B1 to B4 is
attached to the same nitrogen atom, and wherein
B1 to B4 represent a group of substructure II

wherein the broken line symbolises the linkage to said dichroic residue

and wherein :
A1, A2, A3 each independently represent an aromatic or alicyclic
group, which is unsubstituted or substituted by fluorine
chlorine, cyano, nitro, or a straight-chain or branched alkyl
residue, which is unsubstituted, mono-substituted by cyano or
halogeno, or poly-substituted by halogeno, having 1 to 18
carbon atoms, and wherein one or more of the non-adjacent
CH2 groups may independently be replaced by Q, whereby Q
represents -O-, -CO-, -CO-O-, -O-CO-, -Si(CH3)2-O-Si(CH3)2-,
-NR2-, -NR2-CO-, -CO-NR2-, -NR2-CO-O-, -O-CO-NR2-,
-NR2-CO-NR2-, -CH=CH-, -CDC-, -O-CO-O-, and R2
represents hydrogen or straight-chain or branched d-Cs alkyl,
preferably straight-chain or branched C1-C3 alkyl;
S1, S2 represent a single covalent bond or a spacer unit, such as a
straight-chain or branched alkylene residue, which is
unsubstituted, mono-substituted by cyano or halogeno, or
poly-substituted by halogeno, having 1 to 24 carbon atoms,
wherein one or more of the non-adjacent CH2 groups may
independently be replaced by Q, wherein Q has the meaning
given above;
Z1, Z2 independently represent a single covalent bond or a spacer
unit, such as a straight-chain or branched alkylene residue,
which is unsubstituted, mono-substituted by cyano or halogeno,
or poly-substituted by halogeno, having 1 to 8 carbon atoms,
wherein one or more of the non-adjacent CH2 groups may
independently be replaced by Q, -N=N- or -CR2=C-CO-,
wherein Q and R2 have the meaning given above;

P represents a polymerisable group;
m1, m2, m3 independently are 0 or 1; and
o is 0 or 1, whereby the sum of the symbols o in B1 to B4 is > 0,
or at least one polymerisable dichroic dye selected from
an azo dye of the formulae IV and V:
R4-Ar1-N=N-Ar2-N=N-Ar3-B1 IV
R4-Ar1-N=N-Ar2-N=N-Ar3-N=N-Ar4-B1 v
wherein
R4 represents hydrogen, fluoro, chloro, bromo, cyano, nitro, -NR2R3, a
three- to seven-membered cyclic amino group, -CR2=CR3-NO2,
-CR2=CR3-CN, -CR2=C(CN)2, or a straight chain or branched alkyl
residue, which is unsubstituted, mono- or poly-substituted by fluorine
having 1-18 carbon atoms, wherein one or more of the non-adjacent
CH2 groups may independently be replaced by -O-, -CO-O-, -O-CO-,
-NR2-CO-, -CO-NR2-, -NR2-CO-O-, -O-CO-NR2-, -CH=CH-, -CDC-,
-O-CO-O-, wherein R2 and R3 independently represent hydrogen or
lower alkyl;
Ar1, Ar2, Ar3, Ar4 independently of each other are 1,4-phenylene, 1,4- or
1,5-naphthylene optionally substituted by fluorine, chlorine, hydroxy,
-NR2R3 or by a straight chain or branched alkyl residue, which is
unsubstituted, mono- or poly-substituted by fluorine having 1-12
carbon atoms, wherein one or more of the non-adjacent CH2 groups

may independently be replaced by -O-, -CO-O-, -O-CO-, -NR2-CO-,
-CO-NR2-, -NR2-CO-O-, -O-CO-NR2-, -CH=CH-, -CDC-, -O-CO-O-,
wherein R2 and R3 independently represent hydrogen or lower alkyl;
and
wherein Ar1 is also a group of formula a) to c)

wherein p is an integer of 1 to 3 and R4 of formulae IV and V is
attached to the nitrogen atom; and
B1 has the meaning given above.
2. A mesogenic, crosslinkable mixture as claimed in claim 1, wherein the
aromatic group is a optionally substituted carbocyclic or heterocyclic group
comprising five-, six- or ten-membered ring systems.
3. A mesogenic, crosslinkable mixture as claimed in claims 1 or 2, wherein the
aromatic group is furane, phenyl, pyridine, pyrimidine, naphthalene or
tetraline.
4. A mesogenic, crosslinkable mixture as claimed in any preceding claim,
wherein the alicyclic group is a non-aromatic carbocyclic or heterocyclic ring
system having 3 to 10 carbon atoms.
5. A mesogenic, crosslinkable mixture as claimed in any preceding claim,
wherein the alicyclic group is cyclopropane, cyclobutane, cyclopentane,
cyclopentene, cyclohexane, cyclohexene, cyclohexadiene or decaline.

6. A mesogenic, crosslinkable mixture as claimed in any of preceding claims,
wherein the straight-chain or branched alkyl group is selected from the
group comprising methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl,
tert-butyl, pentyl, isopentyl, cyclopentyl, hexyl, cyclohexyl, heptyl, octyl,
nonyl, decyl, undecyl, dodecyl, 3-methylpentyl, allyl, but-3-en-1-yl,
pent-4-en-1-yl, hex-5-en-1-yl, propynyl, butynyl, pentynyl, methoxy, ethoxy,
propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy, terf-butoxy, pentyloxy,
isopentyloxy, cyclopentyloxy, hexyloxy, cyclohexyloxy, heptyloxy, octyloxy,
nonyloxy, decyloxy, undecyloxy, dodecyloxy, 3-methylpentyloxy, allyloxy,
but-3-enyloxy, pent-4-enyloxy, cylohexylmethoxy, cyclopentylmethoxy,
methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, isopropoxycarbonyl,
butoxycarbonyl, isobutoxycarbonyl, sec-butoxycarbonyl, tert-butoxy-
carbonyl, pentyloxycarbonyl, isopentyloxycarbonyl, cyclopentyloxycarbonyl,
hexyloxycarbonyl, cyclohexyloxycarbonyl, octyloxycarbonyl, nonyloxy-
carbonyl, decyloxycarbonyl, undecyloxycarbonyl, dodecyloxycarbonyl,
3-methylpentyloxycarbonyl, allyloxycarbonyl, but-3-enyloxycarbonyl,
pent-4-enyloxycarbonyl, cylohexylmethoxycarbonyl, cyclopentylmethoxy-
carbonyl, acetoxy, ethylcarbonyloxy, propylcarbonyloxy, isopropyl-
carbonyloxy, butylcarbonyloxy, isobutylcarbonyloxy, sec-butylcarbonyloxy,
tert-butylcarbonyloxy, pentylcarbonyloxy, isopentylcarbonyloxy, cyclopentyl-
carbonyloxy, hexylcarbonyloxy, cyclohexylcarbonyloxy, octylcarbonyloxy,
nonylcarbonyloxy, decylcarbonyloxy, undecylcarbonyloxy, dodecyl-
carbonyloxy, 3-methylpentylcarbonyloxy, but-3-enyloxy, pent-4-enyloxy,
acetyl, ethylcarbonyl, propylcarbonyl, isopropylcarbonyl, butylcarbonyl,
isobutylcarbonyl, sec-butylcarbonyl, pentylcarbonyl, isopentylcarbonyl,
cyclohexylcarbonyl, octylcarbonyl, nonylcarbonyl, decylcarbonyl, undecyl-
carbonyl, dodecylcarbonyl, methoxyacetoxy, 1-methoxy-2-propoxy,
3-methoxy-1-propoxy, 2-methoxyethoxy, 2-isopropoxyethoxy,
1-ethoxy-3-pentyloxy, 3-butynyloxy, 4-pentynyloxy, 5-chloropentynyl,
4-pentynecarbonyloxy, 6-propyloxyhexyl, 6-propyloxyhexyloxy,
2-fluoroethyl, trifluoromethyl, 2,2,2-trifluoroethyl, 1H,1H-pentadecafluoro-
octyl, 1H,1H,7H-dodecafluoroheptyl, 2-(perfluorooctyl)ethyl, 2-(perfluoro-

butyl)ethyl, 2-(perfluorohexyl)ethyl, 2-(perfluorodecyl)ethyl, perfluoropropyl,
perfluorobutyl, perfluoroheptyl, perfluorooctyl, perfluorononyl.
1-fluoropropoxy, 1-fluoropentyloxy, 2-fluoropropoxy, 2,2-difluoropropoxy,
3-fluoropropoxy, 3,3-difluoropropoxy, 3,3,3-trifluoropropoxy, and trifluoro-
methoxy.
7. A mesogenic, crosslinkable mixture as claimed in any of preceding claims,
wherein A1, A2 and A3 independently of each other are unsubstituted,
saturated five- or six-membered alicyclic rings or six-membered aromatic
rings, optionally substituted by fluorine or chlorine or nitro or by a straight
chain or branched alkyl residue, which is unsubstituted, mono- or poly-
substituted by fluorine having 1-12 carbon atoms, wherein one or more of
the non-adjacent CH2 groups may independently be replaced by -O-,
-CO-O-, -O-CO-, -NR2-CO-, -CO-NR2-, -NR2-CO-O-, -O-CO-NR2-,
-CH=CH-, -CDC-, -O-CO-O-, wherein R2 represents hydrogen or lower
alkyl.
8. A mesogenic, crosslinkable mixture as claimed in any preceding claims,
wherein A1, A2 and A3 are a unsubstituted cyclopentane-1,3-diyl,
unsubstituted cyclohexane-1,4-diyl, or 1,4-phenylene, which is
unsubstituted, mono- or poly-substituted by fluorine or chlorine or a straight-
chain or branched alkyl residue, which is unsubstituted, mono- or poly-
substituted by fluorine having 1-12 carbon atoms, wherein one or more of
the non-adjacent CH2 groups may independently be replaced by -O-,
-CO-O-, -O-CO-, -CH=CH-, -C=C-.
9. A mesogenic, crosslinkable mixture as claimed in any preceding claims,
wherein S1 and S2 are selected from the group comprising -(CH2)r-,
-(CH2)r-O-, -(CH2)r-CO-, -(CH2)r-CO-O-, -(CH2)r-O-CO-, -(CH2)
r-CO-NR2-, -(CH2)r-NR2-CO-, -(CH2)r-NR2-, -(CH2)r-O-(CH2)s-, -(CH2)

r-CO-O-(CH2)s-, -(CH2)r-O-CO-(CH2)s-, -(CH2)r-NR2-CO-(CH2)s-,
-(CH2)r-NR2-CO-O-(CH2)s-, -(CH2)r-O-(CH2)s-O-, -(CH2)r-CO-O-(CH2)
s-O-, -(CH2)r-O-CO-(CH2)s-O-, -(CH2)r-NR2-CO-(CH2)s-O-, -(CH2)
r-NR2-CO-O-(CH2)s-O-, -O-(CH2)r-, -CO-O-(CH2)r-, -O-CO-(CH2)r-,
-NR2-CO-(CH2)r-, -CO-NR2-(CH2)r, -NR2-(CH2)r-, -O-(CH2)r-CO-O-,
-O-(CH2)r-O-CP-, -O-(CH2)r-CO-NR2-, -O-(CH2)r-NR2-, -O-(CH2)r-O-,
-O-(CH2)r-NR2-CO-, -NR2-(CH2)r-CO-O-, -NR2-(CH2)r-O-, -NR2-(CH2)
r-NR2-, -NR2-(CH2)r-O-CO-, -CO-NR2-(CH2)r-O-, -CO-NR2-(CH2)r-NR2-,
-CO-NR2-(CH2)r-O-CO-, -O-CO-(CH2)r-CO-, -O-CO-(CH2)r-O-,
-O-CO-(CH2)-NR2-, -O-CO-(CH2)r-CO-O-, -O-CO-(CH2)r-CO-NR2-,
-O-CO-(CH2)r-NR2-CO-, -O-(CH2)r-O-(CH2)s-, -O-(CH2)r-CO-O-(CH2)s-,
-O-(CH2)r-NR2-CO-(CH2)s-, -O-(CH2)r-NR2-CO-O-(CH2)s-, -O-(CH2)
r-C0-0-(CH2)s-O-,-O-(CH2)r-O-(CH2)s-O-,-O-(CH2)r-NR2-CO-(CH2)s-O-,
-O-(CH2)r-NR2-CO-O-(CH2)s-O-, -CO-O-(CH2)r-O-(CH2)s-, -CO-O-(CH2)
r-O-(CH2)s-O-, wherein r and s are each an integer from 1 to 20, the sum of
r + s ? 21, wherein R2 represents hydrogen or lower alkyl, and which are
attached to the dichroic residue and the polymerisable group, respectively,
such that heteroatoms are not directly linked to each other.
10. A mesogenic, crosslinkable mixture according to in any of preceding claims,
wherein S1 is selected from the group comprising -(CH2)r-, -(CH2)r-O-,
-(CH2)r-CO-O-, -(CH2)r-O-CO-, -(CH2)r-CO-NH-, -(CH2)r-NH-CO-, -(CH2)
r-NH-CO-(CH2)s-, -(CH2)r-NH-CO-O-(CH2)s-, -(CH2)r-O-(CH2)s-O-, -(CH2)
r-NH-CO-(CH2)s-O-, -(CH2)r-NH-CO-O-(CH2)s-O-, -O-(CH2)r-,
-CO-O-(CH2)r-, -CO-NH-(CH2)r-, -O-CO-(CH2)r-, -O-CO-(CH2)r-CO-O-,
-O-(CH2)r-O-CO-, -O-(CH2)r-CO-NH-, -O-(CH2)r-NH-CO-, -CO-O-(CH2)

r-O-, -CO-NH-(CH2)r-O-, -O-(CH2)r-O-, -O-(CH2)r-NH-CO-(CH2)s-,
-O-(CH2)r-O-(CH2)s-O-, -O-CO-(CH2)r-O-(CH2)s-O-, -CO-O-(CH2)
r-O-(CH2)s-O-, -O-(CH2)r-NH-CO-(CH2)s-O-, -O-CO-(CH2)r-NH-CO-(CH2)
s-O-, wherein r and s are each an integer from 1 to 16, the sum of r +
s ? 18 and which are attached to the dichroic residue and the polymerisable
group, respectively, such that heteroatoms are not directly linked to each
other.
11. A mesogenic, crosslinkable mixture as claimed in any of preceding claims,
wherein S1 selected from the group comprising -(CH2)r-, -(CH2)r-O-,
-(CH2)r-CO-O-, -(CH2)r-O-CO-, -(CH2)r-O-(CH2)s-O-, -(CH2)
r-NH-CO-O-(CH2)s-O-, and if attached to a carbon atom of the dichroic
residue also -O-(CH2)r-, -CO-O-(CH2)r-, -O-CO-(CH2)r-, -O-CO-(CH2)
r-CO-O-, -O-(CH2)r-O-CO-, -CO-O-(CH2)r-O-, -O-(CH2)r-O-, -O-(CH2)
r-O-(CH2)s-O-, -O-CO-(CH2)r-O-(CH2)s-O-, -CO-O-(CH2)r-O-(CH2)s-O-,
wherein r and s are each an integer from 1 to 12, the sum of r + s ? 14, and
which are attached to the dichroic residue and the polymerisable group,
respectively, such that heteroatoms are not directly linked to each other.
12. A mesogenic, crosslinkable mixture as claimed in any of preceding claims,
wherein S1 is selected from the group comprising 1,2-ethylene,
1,3-propylene, 1,4-butylene, 1,5-pentylene, 1,6-hexylene, 1,7-heptylene,
1,8-octylene, 1,9-nonylene, 1,10-decylene, 1,11-undecylene,
1,12-dodecylene, 3-methyl-1,4-butylene, 3-propyleneoxy,
3-propyleneoxycarbonyl, 2-ethylenecarbonyloxy, 4-butyleneoxy,
4-butyleneoxycarbonyl, 3-propylenecarbonyloxy, 5-pentyleneoxy,
5-pentyleneoxycarbonyl, 4-butylenecarbonyloxy, 6-hexyleneoxy,
6-hexyleneoxycarbonyl, 5-pentylenecarbonyloxy, 7-heptyleneoxy,
7-heptyleneoxycarbonyl, 6-hexylenecarbonyloxy, 8-octyleneoxy,
8-octyleneoxycarbonyl, 7-heptylenecarbonyloxy, 9-nonyleneoxy,

9-nonyleneoxycarbonyl, 8-octylenecarbonyloxy, 10-decyleneoxy,
10-decyleneoxycarbonyl, 9-nonylenecarbonyloxy, 11-undecyleneoxy,
11-undecyleneoxycarbonyl, 10-decylenecarbonyloxy, 12-dodecyleneoxy,
12-dodecyleneoxycarbonyl, 11-undecylenecarbonyloxy, 3-propyleneimno-
carbonyl, 4-butyleneiminocarbonyl, 5-pentyleneiminocarbonyl,
6-hexyleneiminocarbonyl, 7-heptyleneiminocarbonyl, 8-octyleneimino-
carbonyl, 9-nonyleneiminocarbonyl, 10-decyleneiminocarbonyl,
11-undecyleneiminocarbonyl, 12-dodecyleneiminocarbonyl, 2-ethylene-
carbonylimino, 3-propylenecarbonylimino, 4-butylenecarbonylimino,
5-pentylenecarbonylimino, 6-hexylenecarbonylimino, 7-heptylenecarbonyl-
imino, 8-octylenecarbonylimino, 9-nonylenecarbonylimino, 10-decylene-
carbonylimino, 11-undecylenecarbonylimino, 6-(3-propyleneiminocarbonyl-
oxy)hexyl, 6-(3-propyleneoxy)hexyl, 6-(3-propyleneoxy)hexyloxy,
6-(3-propyleneiminocarbonyloxy)hexyloxy, 6-(3-propyleneiminocarbonyl)
hexyl, 6-(3-propyleneiminocarbonyl)hexyloxy, 1,2-ethylenedioxy,
1,3-propylenedioxy, 1,4-butylenedioxy, 1,5-pentylenedioxy, 1,6-hexylene-
dioxy, 1,7-heptylenedioxy, 1,8-octylenedioxy, 1,9-nonylenedioxy,
1,10-decylenedioxy, 1,11-undecylenedioxy, and 1,12-dodecylenedioxy.
13. A mesogenic, crosslinkable mixture as claimed in any of preceding claims,
wherein Z1 and Z2 groups are a single covalent bond or a straight-chain or
branched alkylene residue, which is unsubstituted, mono-substituted or
poly-substituted by fluoro, having 1 to 8 carbon atoms, wherein one or more
of the non-adjacent CH2 groups may independently be replaced by -O-,
-CO-, -CO-O-, -O-CO-, -NR2-CO-, -CO-NR2-, -NR2-CO-O-, -O-CO-NR2-,
-CH=CH-, -CDC-, -O-CO-O-, -N=N-, -CR2=C-CO-, wherein R2 represents
hydrogen or lower alkyl.
14. A mesogenic, crosslinkable mixture as claimed in any of preceding claims,
wherein Z1 and Z2 groups are a single covalent bond or a straight-chain or
branched alkylene residue, having 1 to 6 carbon atoms, wherein one or

more of the non-adjacent CH2 groups may independently be replaced by
-O-, -CO-O-, -O-CO-, -CH=CH-, -CDC-, -O-CO-O-, -N=N-, -CR2=C-CO-,
wherein R2 represents hydrogen or lower alkyl.
15. A mesogenic, crosslinkable mixture as claimed in any of preceding claims,
wherein Z1 and Z2 groups are a single covalent bond or a straight-chain or
branched alkylene residue, having 1 to 4 carbon atoms, wherein one or two
of the non-adjacent CH2 groups may independently be replaced by -O-,
-CO-O-, -O-CO-, -N=N-.
16. A mesogenic, crosslinkable mixture as claimed in any of preceding claims,
wherein the polymerisable groups P are selected from the group of
CH2=CW-, CH2=CW-C00-, CH2=CH-CO-NH-, CH2=C(Ph)-CO-NH-,
CH2=CH-O-, CH2=CH-OOC-, Ph-CH=CH-, CH2=CH-Ph-, CH2=CH-Ph-O-,
R3-Ph-CH=CH-COO-, R3-OOC-CH=CH-Ph-O-, N-maleinimidyl, wherein
W is hydrogen, chloro or methyl,
R3 is lower alkyl or lower alkoxy,
Ph- is phenyl, and
-Ph- is 1,4-phenylene.
17. A mesogenic, crosslinkable mixture as claimed in any of preceding claims,
wherein the polymerisable groups P are CH2=CW-, CH2=CW-COO-,
CH2=CH-O- wherein W is hydrogen or methyl.
18. A mesogenic, crosslinkable mixture as claimed in any preceding claims,
wherein the number of rings in substructure II expressed by m1 + m2 + m3
is ? 2.
19. A mesogenic, crosslinkable mixture as claimed in any of preceding claims,
wherein at least one of the LCP components comprises more than one

20. A mesogenic, crosslinkable mixture as claimed in any of preceding claims,
further comprising isotropic compounds comprising two or more
polymerisable groups.
21. A mesogenic, crosslinkable mixture as claimed in any of preceding claims
further comprising additives.
22. A mesogenic, crosslinkable mixture as claimed in any of preceding claims,
comprising one to four dichroic dyes of formulae IV, V, VI, VII, VIII, IX, X
and at least two polymerisable liquid crystals comprising each two
polymerisable groups.
23. A mesogenic, crosslinkable mixture as claimed in any of preceding claims,
wherein the total content of dichroic dyes is from 0.1 to 50%wt.
24. A mesogenic, crosslinkable mixture as claimed in any of preceding claims,
wherein the total content of dichroic dyes is from 0.5 to 30%wt.
25. A mesogenic, crosslinkable mixture as claimed in any of preceding claims,
wherein the total content the dichroic dyes is from 0.5 to 20%wt.
26. A mesogenic, crosslinkable mixture as claimed in claim 1, wherein R4
represents hydrogen, chloro, cyano, nitro, -NR2R3, 1-piperidyl- 1-pyrrolidyl
or a straight chain or branched alkyl residue, which is unsubstituted, having
1-12 carbon atoms, wherein one or two of the non-adjacent CH2 groups
may independently be replaced by -O-, -CO-O-, -O-CO-, -CH=CH-, wherein
R2 and R3 independently represent hydrogen or lower alkyl.

27. A mesogenic, crosslinkable mixture as claimed in claim 26, wherein Ar1 to
Ar4 IV and V, independently of each other are 1,4-phenylene or 1,4-
naphthylene optionally substituted by chlorine, hydroxy, -NR2R3 or by a
straight chain or branched alkyl residue, which is unsubstituted, having 1-12
carbon atoms, wherein one or two of the non-adjacent CH2 groups may
independently be replaced by -O-, -CO-O-, -O-CO-, -CH=CH-, wherein R2
and R3 independently represent hydrogen or lower alkyl; and wherein Ar1
additionally is a group of formula a) to c).
28. A mesogenic, crosslinkable mixture as claimed in any of claims 1 to 27,
wherein the dichroic dye of formula IV comprises 0 or 1 1,4-naphtylene unit.
29. A mesogenic, crosslinkable mixture as claimed in any of claims 1 to 27,
wherein the dichroic dye of formula V comprises 0, 1 or 2 1,4-naphtylene
units.
30. A mesogenic, crosslinkable mixture as claimed in claim 1, wherein the
dichroic dye is an anthraquinone of the formulae VI to X, comprising
having one or two of the groups B1 to B4.
31. A mesogenic, crosslinkable mixture as claimed in any of claims 1 or 30,
wherein the dichroic dye is an anthraquinone of the formulae VI, VII or X.
32. Liquid crystalline polymer film formed from a mixture as claimed in any of
claims 1 to 31, by polymerisation.
33. Liquid crystalline polymer film as claimed in claim 32, wherein the film is
coated with further layers.
34. Process of preparing a liquid crystalline polymer film as claimed in claim 32

or 33, on a substrate comprising the steps of
(i) preparing a solution of a mixture according to claims 1 to 38,
(ii) applying said solution to a support,
(iii) evaporating the solvent to obtain a film,
(iv) polymerising said film using UV light to give a cross-linked dichroic
liquid crystal film, and
(v) optionally coating said cross-linked dichroic liquid crystal film with
other layers.
35. Process as claimed in claim 34, wherein the substrate is a transparent
substrate comprising an orientation layer.
36. Process as claimed in claim 35, wherein the transparent substrate is glass
or plastic.
37. Process as claimed in claim 35 or 36, wherein the orientation layer is
rubbed polyimide or polyamide.
38. Process as claimed in claim 35 or 36, wherein the orientation layer
comprises a photo-orientable material.
39. Multilayer system comprising two or more liquid crystalline polymer layers,
wherein at least one of the liquid crystalline polymer layers is a dichroic
liquid crystalline polymer layer formed from a mixture as claimed in any of
claims 1 to 31 by polymerisation.
40. Multilayer system as claimed in claim 39, wherein said layers are covered
by at least one other functional layer.
41. Liquid crystalline polymer films made out of the mixture, as claimed in any
of claims 1 to 31.
42. Electro-optical or optical component or device or security device comprising
a dichroic liquid crystalline polymer film formed from a mixture, as claimed
in claims 1 to 31.
A mesogenic, crosslinkable mixture comprising at least one polymerisable liquid crystal and at least one polymerisable
dichroic dye of the general formula (I) wherein A represents a dichroic residue exhibiting at least partial absorption in the visible
region >400 nm; n1, n2, n3, n4 signifies 0 or 1 whereby the sum of nl, n2, n3, n4 is >0, and B1 to B4 represent a group of substructure
II wherein the broken line symbolises the linkage to said dichroic residue.

Documents:

1338-kolnp-2003-granted-abstract.pdf

1338-kolnp-2003-granted-claims.pdf

1338-kolnp-2003-granted-correspondence.pdf

1338-kolnp-2003-granted-description (complete).pdf

1338-kolnp-2003-granted-examination report.pdf

1338-kolnp-2003-granted-form 1.pdf

1338-kolnp-2003-granted-form 18.pdf

1338-kolnp-2003-granted-form 3.pdf

1338-kolnp-2003-granted-form 5.pdf

1338-kolnp-2003-granted-gpa.pdf

1338-kolnp-2003-granted-letter patent.pdf

1338-kolnp-2003-granted-reply to examination report.pdf

1338-kolnp-2003-granted-specification.pdf

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Patent Number

213957

Indian Patent Application Number

01338/KOLNP/2003

PG Journal Number

04/2008

Publication Date

25-Jan-2008

Grant Date

23-Jan-2008

Date of Filing

17-Oct-2003

Name of Patentee

ROLIC AG.

Applicant Address

CHAMERSTRASSE 50, CH-6301 ZUG SWITZERLAND

Inventors:

#	Inventor's Name	Inventor's Address
1	BUCHECKER RICHARD	N/AFELSENSTRASSE 12,A CH-8008 SWITZERLAND.
2	PEGLOW THOMAS	SCHW ARZWALDSTRASSE GERMANY
3	MOIA FRANCO	FRENKENDORE SWITZERLAND.
4	CHERKAOUI ZOUBAIR M

PCT International Classification Number

C09B69/10

PCT International Application Number

PCT/CH02/00044

PCT International Filing date

2002-01-28

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	01810445.5	2001-05-08	Switzerland