|Title of Invention||
FABRIC SOFTENING COMPOSITIONS
|Abstract||A fabric softening composition comprising : (a) about 4.8% by weight cationic fabric softening agent; and (b) an emulsified silicone; wherein the viscosity of the silicone before emulsification is from about 60,000 cSt to 1,000,000 cSt, and the emulsion is a macro-emulsion.|
THE PATENTS ACT, 1970 (39 of 1970)
COMPLETE SPECIFICATION (See section 10; rule 13)
1. Title of the invention. -
FABRIC SOFTENING COMPOSITIONS
(a) Hindustan Lever Limited
(b) of Hindustan Lever House, 165/166, Backbay Reclamation, Mumbai 400 020, Maharashtra.
(c) an Indian Company ;
The following specification particularly describes the nature of this invention and the manner in which it is to be performed.
FABRIC SOFTENING COMPOSITIONS
The present invention relates to fabric softening
compositions which provide additional benefits to the
fabric, particularly improved crease reduction and/or ease
Background and: Prior Art;;
Fabric softener compositions, especially those added in the rinse, are well known. It is also known to incorporate one or more additional materials such as silicones, to reduce wrinkling of the fabric during the rinsing and drying stages of the wash. For example WO-A-96/15309 discloses the use of a combination of a silicone and a film-forming polymer for this purpose. Typical silicones in this application are polydiorganosiloxanes. Nevertheless, there remains a need in fabric softening compositions-' to formulate'with .additives which not only reduce, the .appearance of' wrinkles, or creases before ironing, but also make ironing easier.
In many prior art compositions, the silicones are incorporated in the form of an emulsion, which is a micro-emulsion, that is to say the silicone is present as liquid droplets having a droplet size less than the wavelength of visible light and so the emulsion is substantially transparent. However, in a few cases, they are macro-emulsions (e.g. WO-A-97/31997 and 98). The silicones before emulsification are those having relatively low
viscosities, because it is assumed that those with higher viscosities are more difficult to handle during the process of manufacturing the product and are less suited for anti-creasing performance. WO-A-95/24460 discloses a fabric softening composition which contains from about 0.2% to about 2 0% of a polydimethyl siloxane having a viscosity from about 2 to 5,000 centi Stok.es . (cSt.) .
It: has .now been discovered that,, surprisingly, good antl-creas-ingf and/or ease-of ironing,' can-be achieved by formulating with a silicone which is incorporated in the form of a macro-emulsion and which silicone has a viscosity of from 1C,OOOcSt to 1,000,OOOcSt, and/or the emulsified silicone has a median droplet size of at least 0.2μm and is emulsified with at least one cationic surfactant.
Definition of the Invention
Thus according to a first aspect of the invention there is provided a' fabric softening composition comprising:-
(a) a cationic fabric softening agent; and
(b) an emulsified silicone;"
wherein the viscosity: of the1 silicone before -emulsif ication is from 10,000cSt to 1,000,OOOcSt, preferably from 30,000cSt to 750,OOOcSt, more preferably from 40,OOOcSt to 400,OOOcSt, most preferably 45,OOOcSt to 250,OOOcSt, eg, 45,OOOcSt to 200,OOOcSt, and the emulsion is a macro-emulsion.
A second aspect of the present invention provides a fabric softening composition comprising:-
(a) a cationic fabric softening agent; and
(b) an emulsified silicone; wherein the median droplet size of the silicone in the emulsion is 0.2μm, preferably at least 0.25μm, more preferably at least 0.3 9μm, preferably also no greater than 25μm and is emulsified with an emulsifier comprising one or more cationic surfactants.
A third aspect of the present invention provides a method of manufacturing ;a fabric, softening composition, the method comprising obtraining'a macro-emulsion- of a silicone having a viscosity of from 10,000cSt to 1,000,OOOcSt and admixing said macro-emulsion with a cationic fabric softening agent.
A fourth aspect of the present invention provides a method of manufacturing a fabric softening composition, the method comprising obtaining the emulsion in the form of an emulsion of a silicone having a viscosity of from 10,0OOcSt to 1,000,OOOcSt, preferably from 30,000cSt to 750,OO0cSt, more preferably from 40,000cSt to 400,000cSt, most preferably 45,OOOcSt to 250, OOOcSt', eg 45,OOOcSt to 200,OOOcSt the median droplet size of the silicone in the emulsion being at least 0.2/im, preferably at least 0.25^m, more preferably at least 0 .39μm,' preferably-also no'greater than 25μm ;,and- is emulsified with an emulsifier comprising one or more cationic surfactants, and admixing said emulsion with a cationic fabric softening agent.
Compositions according to the present invention may optionally embody both the first and second aspects of the present invention and processes for their manufacture optionally may embody the third and fourth aspects. A
method of using a composition according to the first and/or second aspects of the present invention by applying it to a fabric or textile for softening the fabric or textile, constitutes another aspect of the invention.
For the avoidance of doubt, in the context of the present invention, the term emulsified silicone means that the silicone, is. in emulsion form prior to incorporation in the fabric softening composition and does not necessarily remain in that forw in the final product?.
The cationic fabric softening agent may comprise one or more cationic fabric softening materials and the eMulsified sili -one may comprise one or more individual silicone materials.
Detailed Description of the Invention
Cationic Fabric Softening Agents
Preferably/ the cationic fabric softening agent is a quaternary ammonium material ox, a quaternary ammonium material 'containing at least one ester group. The' quaternary ammonium compounds containing at least one ester group are referred to herein as ester-linked quaternary ammonium compounds.
As used herein'the term ester group , when used as a group in the quaternary ammonium material, includes an ester group which is a linking group in the molecule.
It is preferred for the ester-linked quaternary ammonium compounds to contain two or more ester groups. In both monoester and the diester quaternary ammonium compounds it is preferred if the ester group (s) is a linking group between the nitrogen atom and an alkyl group. The ester group (s) is preferably attached to the nitrogen atom via another hydrocarb.yl group,
Also preferred are quaternary ammonium compounds containing at least one ester group,, preferably two, wherein at.- least one higher molecular weight group containing at least one ester group and two or three lower molecular weight groups are linked to a common nitrogen atom to produce a cation and wherein the electrically balancing anion is a halide, acetate or lower alkosulphate id, such as chloride or methosulphate. The higher molecular weight substituent on the nitrogen is preferably a higher alkyl group, containing 12 to 28, preferably 12 to 22, e.g. 12 to 20 carbon atoms, such as coco-alkyl, tallowalkyl, hydrogenated tallowalkyl or substituted higher alkyl, and the lower molecular weight subsrituents are preferably lower alkyl of 1 to 4 carbon atoir.s, such as methyl or ethyl, or substituted lower alkyl. One or more of the' said lower molecular weight substituents may include an aryl moiety or may be replaced by an aryl, such as benzyl, phenyl or other suitable substituents.
Preferably the quaternary ammonium material is a compound
having two C12-C22 alkyl or alkenyl groups connected to a
quaternary ammonium head group via at least one ester link, preferably two ester links or a compound comprising a single
long-chain with an- average chain length equal to or greater than C20.
More preferably, the quaternary ammonium material comprises a compound having two long chain alkyl or alkenyl chains with an average chain length equal to or greater than C14. Even more preferably each chain has an average chain length-equal to or greater than C16. Most preferably at least 50% of each long.'tChain alkyl or alkenyl group has a chain length
of C18'. It is preferred- if the long chain- alkyl or alkenyl
groups are predominantly linear.
The most preferred type of ester-linked quaternary ammonium material that can be used in composition's according to the invention is represented by the formula (A):
wherein each R group is independently selected from C1_4
alkyl, hydroxyalkyl or C2-4 alkenyl groups; and wherein each
R group is independently selected from C8-28 alkyl or
alkenyl groups; X' is any suitable counter-ion, i.e. a halide, acetate or lower alkosulphate ion, such as chloride or methosulphate.
n is an integer from 1-5 or is 0
It is advantageous for environmental reasons if the quaternary ammonium material is biologically degradable.
Preferred materials of this class such as 1,2 bis[hardened tallowoyloxy] -,3-trimethylammo.ni.um Another class of preferred ester-linked quaternary ammonium, materials for use in compositions according to the invention can be represented by the formula (B):
It is especially preferred that each R group is methyl and each n is 2.
Of the compounds of formula (B) , Di-(tallowyloxyethyl)-dimethyl ammonium chloride, available from Hoechst, is the most preferred. Di-(hardened tallowyloxyethyl)dimethyl ammonium' chloride, ex Hoechst* and >di- (dallowyroxye'thyl);-methyl hydroxyethyl methosulphate are also preferred.
Another, preferred class of quaternary ammonium, ca'tionic fabric softening agent is defined by formula (C):-
where R1 , R2 and X are as hereinbefore defined,
A preferred1 material; of: formula '(C) . is di-:hardened: tallow-diethyl ammonium chloride, sold under the Trademark Arquad 2HT.
The optionally ester-linked quaternary ammonium material may contain optional additional components, as known in the art, in particular, low molecular weight solvents, for instance isopropanol and/or ethanol, and co-actives such as nonionic softeners, for example fatty acid or sorbitan esters.
The fabric softening agent is present in the composition preferably in a total amount of 0.5% - 50% by weight based upon the total weight of the composition, more preferably 0.5% to 35%, more preferably 1-30%, more preferably 3-25%, most preferably 3-20%, eg 8-20%.
According to .the. first and.third aspects- of. the present-invention, in the emulsified silicone, the silicone droplets are incorporated to be in the form of a macro-emulsion, that is to say the droplets have a median size in the wavelength range corresponding to the visible spectrum, or even larger. Preferably, the emulsion is an oil-in-water emulsion. The term median size refers to the number average. The visible spectrum is 0.39,um to 0.77μm. In the emulsion, the silicone droplets are then preferably from 0.39μm to 25μm. In the second and fourth aspects of the present invention, in. the emulsion, the silicone droplets have a median, size of at' least 0.2μm, preferably at least 0.25μm. The droplet size may be determined based on measurements of meaian DV05 using a Malvern X Mastersizer.
The silicone may be of any structure which gives rise to one or more of the desired benefits in use of the fabric softener formulation. Preferably, it has a linear structure. It is preferably a non-functional silicone, especially one which is non-amino functional. Typical silicones are siloxanes which have the general formula
RaSiO(4-a)/2 wherein each R is the same or different and is
selected from hydrocarbon and hydroxyl groups, 'a' being from 0 to 3 and in the bulk material; 'a' has an average value of from 1.85-2.2.
Most preferably, the silicone is a polydi-C1-6 alkyl (preferably a polydimethylj siloxane end-terminated either by tri-C1_6 alkylsilyl (e.g. trimethylsilyl) or hydroxy-di-
C1-6 alkylsilyl (e.g. hydroxy-dimethylsilyl) groups, or by both.
Certainly, in the case of compositions according to the first and third aspects of the present invention and preferably , in the case of compositions according to the second and fourth aspects, the silicone has a viscosity before emulsification (as measured on a Brookfield RV4 viscometer at 25°C using spindle No.4 at 100 rpm) of from 10,000cSt to 1,000,OOOcSt, preferably from 30,000cSt to 750,000cSt, more preferably from 40,000cSt to 400,000cSt, most preferably 45,000cSt to' 250,000cSt, eg 45,000cSt to 200,000 cSt.
Preferably, in'compositions according to the' first and-third aspects of the present invention and certainly in those according to the second and fourth aspects of the invention, emulsification is effected using one or more cationic surfactants, preferably having a non-halogen counter-ion.
The cationic emulsifiers are believed to enhance deposition of the silicone during use of the fabric softening composition. Preferred counter-ions include methosulphate,
ethosulphate, tosylate, phosphate and nitrate. If a halogen counter-ion is used, it is preferably chloride.
For example, mixtures of one or more cationic and one or more nonionic surfactants can be used, or even nonionic surfactant(s) alone.
Preferably, the total of amount of emulsifying surfactant(s) is from 0.5% to 20%, preferably from-2% to 12%, more preferably from 3.% to 10% by weight, of .the emulsion.
The emulsified silicone (as 100% active silicone) may be included in the fabric softener compositions in an amount of 3.5% to 15% by weight of the total carposition (including the emulsion product containing the silicone emulsion), preferably 3.75% to 12%, more preferably 4% to 10%, most preferably 4.5% to 10%. However, it may be possible to include up to 20% by weight if it can be incorporated into the fabric softening composition without instability occurring, therein. The total amount-of silicone-in the emulsion will generally be up, to 70% by weight of the emulsion.
Preferably, the weight ratio of silicone to total emulsifying surfactant(s) is from.2.3:1 to 120:1, more preferably 3:1 to 120:1, for example from 3:1 to 30:1. Typical cationic surfactants are alkyl tri-methylammonium methosulphates and derivatives in which at least two of the methyl groups on the nitrogen atom are replaced by (poly)alkoxylated groups.
In the final product, the weight ratio of total fabric softening agent to total silicone is from 1:1 to 70:1, more preferably from 1.5:1 to 25:1, more preferably 2.5:1 to 10:1, eg 3:1 to 7:1.
The compositions may 'Comprise perfume. If present, the level of perfumes in "the compositions may be 0.2 5% to 2% by weight, preferably 0.27%, to 2%, such as 0.3% to 1.5%.
The compositions may also contain one or more optional ingredients, selected from electrolytes, non-aqueous solvents, pH buffering agents, perfume carriers, fluorescers, colorants, hydrotropes, antifoaming agents, antiredeposition agents, polymeric and other thickeners, enzymes, optical brightening agents, opacifiers, anti- shrinking agents,; auxiliary anti-wrinkle, agents, anti- spotting agents, germicides, fungicides, anti-oxidants, anti-corrosion agents, drape imparting agents, antistatic
agents, sunscreens:, colour: care agents: and auxiliary ironing: aids.
The preferred product form is a liquid, more especially an aqueous liquid. In liquid products, a viscosity control agent may be included. Any viscosity control agent typically used with rinse conditioners is suitable, for example biological polymers such as Xanthum gum (Kelco ex Kelsan and Rhodopol ex Rhone-Poulenc)- Synthetic polymers
may also be used as viscosity control agents e.g. polyacrylic acid, poly vinyl pyrolidone, polyethylene, carbomers, polyethylene, polyethylene glycols and cellulose-based thickeners such as hydroxy-ethyl cellulose modified to include long chain substituent groups. Also suitable as viscosity modifiers are decoupling polymers and defloccculating polymers.
It is preferred that the compositions are substantially free of bleaches.
However, the Composition' may be in any form conventionally used for fabric softening compositions for example, powder, paste or gel. It is preferred if the final product itself is a liquid and especially an aqueous emulsion, preferably a macro-emulsion and not a micro-emulsion, containing suspended fabric softener and emulsified silicone droplets.
A fabric. softening composition within, the-, scope of the . present invention may comprise 8 to 50% by weight of a cationic fabric softening agent; and perfume; and 3.5 to 15% by weight of an emulsified silicone (all weights being of the total weight of the composition) the silicone having been emulsified with one or more cationic surfactants to form a macro-emulsion with the viscosity of the silicone before emulsification being from 10,000cSt to 400,000cSt,
preferably from 20,000cSt to 350,000cSt, more preferably from 25,000cSt to 250,000cSt.
Another fabric softening composition with the scope of the invention may comprise 8 to 50% by weight of a cationic fabric softening agent; and perfume; and 3.5 to 15% by weight of an emulsified silicone (all weights being of the total weight of the composition:) the median droplet size of the emulsified silicone being at'least 0.2^xm, preferably at least 0.25μm, more preferably at least 0.39μm, preferably-also no greater than 25μm and the silicone being emulsified with an emulsifier comprising one or more cationic surfactants.
A dimethyl-terminated polydimethylsiloxane (PDMS) having a viscosity of 60,0OOcSt was formulated as an aqueous emulsion thus in
Component % wt
COCOTMAMS (1) 3.5
COCOPEMAMS (2) 1.9
Water, preservatives to 100
(1) coconut trimethylammonium methosulphate
(2) coconut pentaethoxymethylammonium methosulphate
Examples 1 and 2
The emulsion of Example A was. included in dilute (Example 1) and concentrate (Example 2) forms of fabric softener compositions, in which .amounts1- are % by weight of the totals composition:-
(3) Mixture of 1,2 bis[hardened tallowoxy]-3-trimethyl
ammonium: propane chloride and, free fatty
acid in a weight ratio of 6:1.
Example 3 (Performance Evaluation)
Compositions comprising by weight 12.1% of the cationic softener of Examples 1 and 2, 0.7% coconut 2 0 EO nonionic, 0.7% tallow alcohol and 3% polydimethyl-siloxane (% active) obtained from different emulsions containing nonionic emulsifier and 50'%' by weight of the silicone active: ingredient. , To evaluate the first and third aspects-of the present invention, the viscosity and median droplet sizes were varied between these different emulsions.
The nonionic-emulsified silicone emulsion was type HV600, avEiilable ex Dow Corning, but with the silicone viscosity and median aroplet size being varied by the supplier, the other components being per the standard commercial product.
These formulations were evaluated in the rinse cycle as follows:-
White cotton shirts were washed 4 times at 60°C to remove any pre-existing treatments which would distort the results.
Wash/rinse/dry cycles were then carried out. The conditions were as follows:
Machine: Candy Aguaviva 1000
Programme: Programme 5 - Non-fast coloureds
recommended for cotton
Water hardness: 13 °FH (Wirral water)
Main wash product: 150g Persil Bio powder via shuttle Rinse products: 35 gm of a control\ composition
containing 3% PDMS'with a
viscosity of. 60., QOOcSt before
emulsification OR 35 gm of a- test
composition containing 3% PDMS
with viscosities before
emulsification in the range
l,0Q0cSt to 75O,000cSt
Washload: 10 shirts
Drying: Hung on rails indoors
2 extra shirts were added to the washes so that extraction could be carried out anc;. silicone, deposition estimated.. These were split evenly over the washes.
Desized cotton, poplin monitors were included 'for each product; 3 X 20cm by 20cm and 3 X 50dm by 100cm desized cotton poplin monitors were also included for measurement of fabric physical properties.
The garments were assessed for:
1. Degree of creasing before ironing
2. Ease of ironing, Using steam
The degree of creasing was assessed by paired comparisons between garments rinsed in the test and control products respectively. The garments were placed in the viewing cabinet and the assessor was asked Which is the least creased? . For the ease of ironing comparison, the panellist ironed two shirts using steam and was asked Which is the .easiest to iron? . The irons used were Philips Azur 50 set at-the. temperature for cotton. 100ml of water was added for each panellist. The steam was set' at: maximum. Separate irons were used for each treatment to avoid possible transfer of rinse conditioner or silicone via the plate of the iron. The irons were washed and swapped halfway through the exercise to compensate for differences in the irons. Identical ironing boards were used.
The result obtained are summarised in the following table:-
Sample (a) does not correspond to the invention, the viscosity being within the prior art range. All of samples (b)-(h) showed a marked improvement in degree of creasing over sample, (a) - All except (d) ,, (e.).. and (h), showed a marked improvement .over (a) in terms of ease of ironing.
Example 4 (Performance Evaluation)
To evaluate the second and fourth aspects of the present invention, a comparison of effects on silicone deposition and performance in anti-creasing and anti-ironing was performed using a base fabric conditioner formulation as control:-
Component wt %
Cationic Softener(5) 4.8
Nonionic 2 0 EO 0.1
Tallow Alcohcl 0.6
(5) Di-ethoxy ester (tallow) -di-methylammonium chloride
To the control formulation was added a PDMS emulsion at an amount equivalent to 1% silicone based on the weight of the softener composition, the balance being water (with minor ingredients) , the viscosity of the silicone being 6'0*,.0'0:0'cSt with a median droplet'diameter of 0 .5μm -and emulsified, either with cationic or nonionic surfactants:-
Cationic System Nonionic System
Cetyl trimethyl HV600 (ex Dow Corning)
ammoniumchloride (4.35%) + COCOPEMANS (1%)
The weights in the cationic system are expressed as % by weight of the emulsion. The HV600 product is the nonionic-emulsified silicone referred to in Example 3.
The products were dosed at 110ml to a washing machine rinse cycle and both shirts and T-shirts were evaluated for anti-creasing and ease of ironing. The cationic and nonionic products were compared as a % of the control (i.e. minus silicone). Silicone deposition was evaluated by a standard method. The results obtained were as follows-.-
■ T-Shirts Anti-crease Benefit % Shirts Anti-crease
% T-Shirts Silicone Deposi¬tion % Shirts Silicone Deposi¬tion %
Non-ionic 35 53 75 62 47 79
Cat-ionic 57 80 85 70 86 98
In all cases/ the- cationic emulsion shows a marked ' improvement in silicone deposition, anti-creasing arid ease of ironing.
1. A fabric softening composition comprising :
(a) about 4.8% by weight cationic fabric softening agent; and
(b) an emulsified silicone;
wherein the viscosity of the silicone before emulsification is from about 60,000 cSt to 1,000,000 cSt, and the emulsion is a macro-emulsion.
2. A composition as claimed in claim 1, wherein, in the emulsified silicone, the median droplet size is from 0.39μm as claimed in to 25μm as claimed in.
3. A method of manufacturing a composition as claimed in claim 2, the method comprising obtaining an emulsion in the form a macro-emulsion of a silicone having a viscosity of from 60,000 cSt to 1,000,000 cSt and admixing the emulsion with a cationic fabric softening agent, and optionally with any other component(s).
4. A composition as claimed in claim 1 wherein the silicone is emulsified with an emulsifier comprising one or more cationic surfactant.
5. A composition as claimed in claim 1, wherein in the emulsion, emulsifying surfactant is present from 0.5% to 20% by weight of the total composition, and silicone to total emulsifying surfactant at a ratio of 3:1 to 120:1.
6. A composition as claimed in claim 1, wherein the catiomc fabric softening agent is selected from quaternary ammonium and ester-linked quaternary ammonium compounds.
7. A composition as claimed in claim 6, wherein the cationic fabric softening agent is selected from 1,2 bis[hardened-tallowoxy]-3-trimethylammonium propane chloride, diethoxy ester(tallow)dimethyl ammoniumchloride, dihardened-tallow-dimethyl
ammoniumchloride and di-(tallowyloxyethyl)methyl hydroxyethyl methosulphate, and mixtures thereof.
8. A composition as claimed in claim 1, wherein the total amount of cationic fabric softening agent is 0.5% to 35% by weight of the total composition.
9. A composition as claimed in claim 1, wherein the silicone is a poly-di-C1-6 alkylsiloxane (preferably polydimethylsiloxane) end-terminated by tri-C1-6 alkylsilyl (preferably trimethylsilyl) groups or by hydroxy-di-C1-6alkylsilyl preferably hydroxy-dimethylsilyl) groups or a mixture of both.
10. A composition as claimed in claim 1, wherein total fabric softening agent weight to total silicone weight is from 1:1 to 70:1.
11. A method of manufacturing a fabric softening composition as claimed in claim 1, the method comprising obtaining an emulsion in the form of an emulsion of a silicon having a viscosity of from 60,000 cSt to 1,000,000 cSt, the median droplet size of the silicone in the emulsion being at least 0.2um claimed in, and the silicone is emulsified with an emulsifier comprising one or more cationic surfactants, and admixing said emulsion with a cationic fabric softening agent, and optionally with any other component(s).
12. A method of softening a fabric, the method comprising applying to that fabric, a composition as claimed in claim 1.
13. A fabric softening composition comprising:
(a) about 4.8% by weight cationic fabric softening agent; and
(b) an emulsified silicone;
wherein the median droplet size of the silicone in the emulsion is at least 0.2 ,as claimed
in, and the silicone is emulsified with an emulsifier comprising one or more cationic surfactant wherein the viscosity of the silicone before emulsification is from about 60,000 cSt to 1,000,000 cSt.
14. A composition as claimed in claim 13, in which the cationic surfactant(s) is/are selected from those having a non-halogen counter-ion and/or selected from those having a nitrogen atom with (poly)alkoxylated groups.
Dated this 19th day of November 2001
Dr.Sanchita Janguli Of S.MAJUMDAR & CO. Applicant's Agents
|Indian Patent Application Number||IN/PCT/2001/01432/MUM|
|PG Journal Number||19/2007|
|Date of Filing||19-Nov-2001|
|Name of Patentee||HINDUSTAN LEVER LIMITED|
|Applicant Address||HINDUSTAN LEVER HOUSE, 165/166 BACKBAY RECLAMATION, MUMBAI - 400 020, MAHARASHTRA, INDIA.|
|PCT International Classification Number||N/A|
|PCT International Application Number||PCT/EP00/04223|
|PCT International Filing date||2000-05-08|