Title of Invention	LCST POLYMER HAVING TERMINAL (METH) ACRYLIC ACID GROUPS AND PROCESS FOR PEPARING THE SAME.
Abstract	Disclosed are polymers of general formula (I), wherein R1 (identically or differently) represents hydrogen or a methyl group, X1 and X2 = -O-, -S-, or -NH-, X1 additionally representing a single bond if the first atom in R2 is not a C atom, and R2 represents one of the following radicals: a) a copolymer radical (Cop) containing at least two structural units -(-O-C2H4)n- (ethylene oxide = EO) and -(-O-C3H6-)n- (propylene oxide = PO), or -(-O-C4H8)n- (butylene oxide = BuO) and -(-O-CH2-)n- (methylene oxide = MeO) at a molar ratio of 5 to 95:95 to 5, n representing approximately 1 to 1000 (identically or differently for each structural unit); b) formula (II), wherein Cop represents a copolymer radical as defined in (a), x = 1 to 5, and y = 1 to 20; c) formula (III), wherein R represents an alkyl group, r = (identically or differently) 1 to 1000, and s = 1 to 500; d) formula (IV), wherein o = 10 to 4000 and R3 (identically or differently) represents hydrogen or alkyl groups comprising 1 to 5 carbon atoms; e) formula (V), wherein p = 5 to 2000; or formula (VI), wherein q = 10 to 4000. Also disclosed are methods for the production thereof and the use thereof for coating particles and non-particulate substrate surfaces.

Title of Invention

LCST POLYMER HAVING TERMINAL (METH) ACRYLIC ACID GROUPS AND PROCESS FOR PEPARING THE SAME.

Abstract

Disclosed are polymers of general formula (I), wherein R1 (identically or differently) represents hydrogen or a methyl group, X1 and X2 = -O-, -S-, or -NH-, X1 additionally representing a single bond if the first atom in R2 is not a C atom, and R2 represents one of the following radicals: a) a copolymer radical (Cop) containing at least two structural units -(-O-C2H4)n- (ethylene oxide = EO) and -(-O-C3H6-)n- (propylene oxide = PO), or -(-O-C4H8)n- (butylene oxide = BuO) and -(-O-CH2-)n- (methylene oxide = MeO) at a molar ratio of 5 to 95:95 to 5, n representing approximately 1 to 1000 (identically or differently for each structural unit); b) formula (II), wherein Cop represents a copolymer radical as defined in (a), x = 1 to 5, and y = 1 to 20; c) formula (III), wherein R represents an alkyl group, r = (identically or differently) 1 to 1000, and s = 1 to 500; d) formula (IV), wherein o = 10 to 4000 and R3 (identically or differently) represents hydrogen or alkyl groups comprising 1 to 5 carbon atoms; e) formula (V), wherein p = 5 to 2000; or formula (VI), wherein q = 10 to 4000. Also disclosed are methods for the production thereof and the use thereof for coating particles and non-particulate substrate surfaces.

Full Text	LCST POLYMER HAVING TERMINAL (METH) ACRYLIC ACID GROUPS AND PROCESS FOR PREPARING THE SAME Description 15The invention relates to LCST (lower critical solution temperature) polymers. This term is used to refer to polymers which are soluble in a liquid medium at a low temperature but above a certain temperature (the LCST temperature) precipitate from the liquid medium. LCST 20polymers have different chemical compositions. The best-known LCST polymers are polyalkylene oxide polymers, examples being polyethylene oxide (PEO) or polypropylene oxide (PPO) polymers, but also (PEO)- (PPO) copolymers, particularly PEO-PPO-PEO block 25copolymers. Other LCST polymers are poly(N-isopropyl- acrylamide)-ethyl-(hydroxyethyl)-cellulose derivatives, poly(N-vinylcaprolactam) derivatives and poly(methyl vinyl ether) derivatives. 30The first-mentioned polymers are described for example in WO 01/60926 Al. That publication relates to a process for coating substrate surfaces (particle surfaces and nonparticulate substrate surfaces) with LCST polymers, for which an LCST polymer is dissolved 35in a solvent at a temperature below the LCST temperature, this solution is mixed with the substrate surfaces to be coated, and the resultant mixture is heated to above the LCST temperature until the deposition of LCST polymers on the substrate surfaces begins. The deposited LCST polymer can be immobilized by providing it with functional groups which allow substantially irreversible adsorption on the substrate surface. The functional groups may be selected from acid groups, hydroxyl groups, amino groups, phosphate groups, mercaptan groups, siloxane groups or hydrophobic groups. Further, the LCST polymers may be provided with functional groups which, following deposition of the LCST polymers on the particles, allow the crosslinking of the LCST polymers in a crosslinking reaction. Functional groups of this kind may be selected from carboxylic acid group derivatives, chloroformate groups, amino groups, isocyanate groups, oxirane groups and/or free-radically crosslinkable groups, with the crosslinking reaction being initiated, inter alia, by a change in the pH of the solution. Free-radical crosslinking is less preferred than cross- linking through a change in pH. The examples specify merely the enveloping of various pigment particles (TiO2, Fe2O3, Cu phthalocyanine blue, and semiconductor wafers with a silicon dioxide surface) with PEO-PPO-PEO block copolymers. Fixing of the copolymersdeposited on the substrate surfaces is not elucidated. The use of LCST polymers for enveloping superpara- magnetic particles is known, further, from WO 97/45202. These particles comprise a core of a first polymer, an inner layer of a second polymer, which coats the core and in which a magnetic material is dispersed, and an outer layer of a third polymer, which coats the magnetic layer and is capable of reacting at least one biological molecule, the second polymer at least being heat-sensitive and having an LCST temperature of 15 to 65°C. The second polymer is obtained preferably by polymerizing (1) a water-soluble acrylamide monomer, such as N-isopropylacrylamide (NIPAM), (2) at least one crosslinking agent, such as N,N-methylenebisacrylamide and (3) at least one functional cationic and water- soluble monomer different than the monomer (1), e.g., the chloride of 2-aminoethyl methacrylate. A further preferred polymer is [poly(N-isopropylacrylamide)] (PNIPAM). Patent Abstracts of Japan, Vol. 009 No. 188 (C295) (1985) page 107 = JP 60 058 237 A describes the encapsulation of inorganic particles. The aim is to prepare a stable particle dispersion. The inorganic particles are suspended in water and contacted below the LCST temperature with an aqueous solution of the LCST polymer. When the temperature of the resulting system is raised, a layer of the LCST polymer is deposited on the inorganic particles. The resultant particle suspension is admixed with a free-radically polymerizable monomer, an initiator and, if desired, an emulsifier, and an emulsion polymerization is carried out, giving encapsulated particles. Now, additionally, there is an outer layer, consisting of the polymerized monomer layer; accordingly, the function of the LCST polymer layer is only to facilitate, the penetration of monomer residues. The polymerizable monomer, then, is reacted with the LCST polymer that is already on the particles, or the water-soluble polymer is enveloped with a layer of the polymer obtained from the polymerizable monomer. This process has the disadvantage that the graft attachment takes place only on the active centers of the pre- deposited LCST polymer, and so the envelopment is nonuniform and heterogeneous and does not constitute a complete barrier. Moreover, it is necessary to add a monomer to the dispersion of the coated particles in order to initiate crosslinking. In the majority of cases the monomer is never fully consumed, and so a certain fraction of the monomer remains in the crosslinked structure. Subsequent emission of the "dissolved" monomers from the polymer is undesirable, since the monomer is injurious to health. Furthermore, disadvantages in the coating system are anticipated as a result of the detachment of the copolymerized emulsifier if the pigment comes into contact with solvents. WO 92/20441 describes a process for generating encapsulated particles, the particles comprising a core surrounded by a coacervate coating. In this process an aqueous solution of an LCST polymer is contacted, at a temperature of reversible insolubilization (TRI), of Tl, with a dispersion of the particles at a temperature of T2, which is lower than Tl, and then the dispersion is heated to a temperature above Tl, thereby depositing the LCST polymer as a coacervate around the particles. Subsequently an agent for lowering the TRI is added to the solution, thereby lowering the TRI of the LCST polymer in the solution to a temperature T3, which is lower than Tl, and then either the dispersion is cooled to a temperature between T3 and Tl and is held at this temperature, or the particles are separated from the dispersion at a temperature of more than T3. As agents for lowering the TRI it is possible to use electrolytes and water-miscible organic liquids in which the LCST polymer is not soluble. LCST polymers used are preferably synthetic polymers (homopolymers or copolymers) with hydrophilic monomers. Suitable LCST monomers are acrylic or vinyl compounds. Where LCST copolymers are used, the comonomer is commonly hydrophilic and may be nonionic or ionic. Suitable nonionic monomers are certain aryl or vinyl compounds. Examples of anionic or cationic monomers are acrylic acid derivatives or dialkylaminoalkyl acrylates. These compounds, however, are already saturated at the ends, and so crosslinking reactions are no longer possible. LCST polymers are also known, for example, from EP 0 629 649 Al. They are used as rheofluidizing additives and antisettling agents in diaphragm wall construction, for wells in the oil industry, and as hydraulic fluids and lubricants. EP 0 718 327 A2 discloses universally compatible pigment dispersants composed of methyl methacrylate and an acrylate or methacrylate. These polymers, however, serve only for dispersing pigments, but not for enveloping pigments. The object on which the invention was based was to provide LCST polymers which on cooling no longer detach from a substrate surface but instead remain firmly joined to it. The polymers are therefore intended to be used without added emulsifiers or monomers, so that no additives can leach from the defined polymer layer. This object is achieved in accordance with the invention by means of LCST polymers of the general formula: in which Rx (identical or different at each occurrence) is hydrogen or a methyl group, X1 and X2 (identical to or different from one another) = -O-, -S- or -NH- and Xx additionally is a single bond if the first atom in R2 is not a carbon atom, and R2 is one of the radicals indicated below: a) a copolymer radical (Cop) containing at least two structural units -(-O-C2H4)n- (ethylene oxide = EO) and - (-O-C3H6-)n- (propylene oxide = PO) or -(-O- C4H8)n- (butylene oxide = BuO) and -(-O-CH2-)n- (methylene oxide = MeO) in a molar ratio of 5 to 95:95 to 5, in which n (identical or different for each structural unit) is approximately 1 to 1000; in which Cop is a copolymer radical as defined in (a) , x = 1 to 5 and y = 1 to 20; in which R is an alkyl group, r = (identical or different at each occurrence) 1 to 1000 and s = 1 to 500; d) in which o = 10 to 4000 and R3 (identical or different at each occurrence) is hydrogen or alkyl groups having 1 to 5 carbon atoms; in which q = 10 to 4000. It has surprisingly been found that the polymers of the invention are irreversibly immobilized on the substrate surface after polymerization on the acrylic or methacrylic side chain. The immobilization is far greater than that of LCST polymers in which the end groups are composed, for example, of simple vinyl groups or other groups with double bonds. Other polymerized units, such as vinylacetic acid, oleic acid, fumaric acid, maleic acid and polyethylene glycol monovinyl ether, are less suitable as end groups. The polymers of the invention commonly have an LCST in the range from 0 to 70°C, which is dependent on factors including the following: molar ratio of the hydrophobic and hydrophilic fractions of the LCST polymer, - molar mass of the LCST polymer, number of polymerizable and ionisable groups, concentration of the polymer, pH and ionic strength of the medium. The LCST polymers are composed of polar and nonpolar or hydrophilic and hydrophobic segments. The LCST can be tailored by varying these individual segments and also the overall chain length. Following the polymerization with the acrylic or methacrylic end groups, the LCST polymers of the invention can be used as dispersants fixed on the substrate surfaces. Among other things, this makes the expensive step of pigment dispersion cheaper, since the pigment carries its dispersant with it. Further, the pigments thus coated form agglomerates to a lesser extent than do untreated pigments, so that dispersion is easier to carry out, resulting in an additional reduction in costs. Dispersants are surface-active substances which facilitate the dispersion of a pulverulent substance, e.g., a pigment or filler, in a liquid dispersion medium, by lowering the surface tension between two components. In the course of pigment grinding they thereby facilitate the mechanical disruption of the secondary particles which are present in the form of agglomerates, into primary particles. Moreover, they protect the primary particles formed from reagglomeration or flocculation by virtue of complete wetting and the formation of a protective colloid shell or an electrochemical double layer. Since the LCST polymers of the invention are transparent or transluscent in visible light, they are able to form a complete envelope around particles, without the color of the particles themselves being affected. Further, in paints, the pigments thus coated display the full color strength, since by virtue of the LCST polymer coating they do not form agglomerates. Preferred LCST polymers fall into groups (a) and (c) . Preferably the radical -(C3H6)- radical in (a) and (c) is an isopropyl radical and the radical (C4H8)- in (a) is an isobutyl radical. The preferred LCST polymers in group (a) are block copolymers, the structural units -(EO)- and -(PO)- on the one hand and the structural units -(BuO)- and - (MeO) - on the other hand being present in blocks with n = 3 to 100. Block copolymers are composed of blocks of homosequences linked to one another via the ends. Graft polymers are composed of what is called a homopolymeric backbone, from which polymer chains of other homopolymers branch out. The blocks with the structural units -(-PO)- and -(-BuO-)- are preferably disposed between the blocks with the structural units -(-EO)- and -(-MeO-), respectively. These block copolymers are referred to for the sake of simplicity as PEO-PPO-PEO block copolymers. A triblock copolymer having the block sequence PEO-PPO-PEO customarily has a PEO weight fraction of about 5% to 85% by weight and number-average molar masses (MN) of 200 to 50,000 g/mol. Alternatively, the different structural units can be randomly distributed. The molar ratio between the -(EO)- structural units and -(PO)- structural units is preferably about 10 to 60 : 40 to 90. The LCST polymers of the invention of versions (a) to (f) can be prepared by reacting a compound of the general formula HO-[R2]-OH, in which R2 is as defined above, with a compound of the formula in which R1 is as defined above and X is OH, halogen, preferably chlorine, or a lower alkoxy group, in a molar ratio of 1:2, or (b) with the anhydride of the corresponding acid in a molar ratio of 1:1. The starting polymers for the LCST polymers of product versions (a) to (c) are in some cases available commer- cially. Additionally, however, they can be prepared as follows: For version (a): The copolymers can be prepared by starting from a compound which is already present in macromolecular form and continuing the polymerization using a polymer of a different kind. The polymerization may take place either in solution in water or in an organic solvent, in emulsion or suspension or by direct reaction of the components in bulk or in powder form in the melt, with or without a catalyst, preferably in a one-stage process. For version (b) : These copolymers are star-shaped and contain as their central linking unit a glycoluril group. They can be prepared as follows: A glycouril unit (Powderlink 1774) is reacted with PEO methyl ether and PPO butyl ether so as to link one or more PEO units to one or more PPO units. Compounds of this kind and their use for coating substrate surfaces, such as pigments, are described for example in the following publications: DE 100 38 147 Al, DE 100 64 240.3 and DE 101 63 985.6. For version (c): The copolymers are prepared with the aid of tosylates. As a result it is possible to link the OH-terminated polyethers (PEO/PPO) with amines. The polyethers are reacted in this case with tosyl chloride (p-toluene- sulfonyl chloride), giving polyether tosylates. Since the tosyl group is a very good leaving group, the polyether tosylates can be reacted with primary amines. Thus it is possible, by way of an aliphatic or aromatic diamine, to link, for example, a PEO unit with a PPO unit. Another possibility is the reaction of PPO diamine with PEO tosylate. In this way a three-block copolymer is obtained. In order to prevent advancement reactions, which would result in undefined products, the polyethers ought to contain only one free OH group. For versions (d) to (f) the corresponding monomers are used. The LCST polymers of the invention can be used for coating particles and nonparticulate substrate surfaces. The particles that are suitable in accordance with the invention include pigments, fillers, and nano- particles. Pigments are pulverulent or platelet-shaped colorants which in contrast to dyes are insoluble in the surrounding medium (DIN 55943: 1993-11, DIN:EN 971- 1: 1996-09). Pigments influence or determine the coloring and for reasons of cost are used in as small amounts as possible. Owing to forces of interaction it is possible for the pigment particles to agglomerate, particularly during incorporation into the matrix material. This results for example, in quality detractions in the resulting paint, as a consequence, inter alia, of deficient color strength, sedimentation or phase separation. Preferred pigments are titanium dioxide, iron oxide, zinc oxide:, carbon black, Cu phthalocyanine pigments, platelet-shaped pigments, such as mica (with or without oxidic and metallic coatings) or aluminum. Fillers which can be used include, for example, barium sulfate and talc. Nanoparticles which can be used include iron oxide, titanium dioxide and silicon dioxide particles. The particles also include microfibers, such as glass, carbon, textile and polymer fibers. The substrate surfaces may also be nonparticulate surfaces, such as those of glass, metal and semiconductors, for example. Particularly preferred surfaces are silicon dioxide wafers which are used in the semiconductors industry. The LCST polymers of the invention are preferably contacted in a liquid medium (e.g., in an aqueous or organic medium) at below the LCST temperature with the particles or the nonparticulate substrate surfaces, and then the temperature is raised to above the LCST temperature and the polymers are polymerized by the double bonds at this temperature or a higher temperature on the surface of the particles or on the nonparticulate substrate surfaces. The synthesis of product version (a) takes place by reacting commercially available PEO-PPO-PEO block copolymers which have terminal OH groups with acrylic or methacrylic acid derivatives, thereby introducing polymerizable double bonds. The introduction can take place by means of the following derivatives: chlorides, esters, anhydrides, amides or free acids, and is acidically or basically catalyzed. This esterification or transesterification can be carried out in a solvent at about 0 to 100°C, but can also be carried out in bulk (without solvent). In order to inhibit unwanted polymerization, small amounts of a polymerization inhibitor are added to the reaction mixture. The synthesis of product version (b) takes place by reacting the polyether-modified glycoluril with acryloyl or methacryloyl chloride, thereby introducing polymerizable double bonds. This reaction can be carried out in a solvent at about 0 to 30°C, but can also be carried out in bulk (without solvent). One possibility of introducing a double bond is to react the product mixture, which ought to contain at least two PEO/PPO segments, with ethylene glycol. After the reaction of the first OH group with the glycoluril unit, the second free OH group of the ethylene glycol is sterically shielded by the polymer chains, and so there ought not to be any reaction with the second glycoluril unit. The free OH group that remains can then be reacted with compounds possessing less steric bulk, such as with acryloyl chloride, for example. The synthesis of product version (c) takes place by reacting the 3-block copolymer, obtained with a tosylate method, on the NH group with acryloyl or methacryloyl chloride, giving polymers containing polymerizable acrylic or methacrylic double bonds. Via this synthesis route it has been possible to link a PPO diamine (2000 g/mol) with PEO (750 g/ml) and to introduce double bonds with acryloyl chloride. In the reaction of PEO tosylate with PPO diamine the temperatures are about 150°C. The precise synthesis instructions are given in Example 5. The synthesis of product version (d) to (f) takes place by an anionic polymerization of the corresponding monomers in solution. In this case a sodium-naphthalene solution serves as initiator. As a result of the use of this initiator system, electron transfer to a fraction of the monomers results in the formation of what are referred to as free-radical anions. The free-radical anions formed combine very rapidly to form dianions, and so chain growth will take place on two sides. An advantage of this polymerization process is that the resulting polymer has a very narrow molar mass distribution. This can be influenced and predicted through the choice and composition of the reactants. The polymerization is terminated with electrophilic substances. The addition of acryloyl chloride or methacryloyl chloride to the reaction solution not only results in the ending of the polymerization but at the same time introduces the acrylic or methacrylic end group. The invention further provides particles or nonparticulate substrate surfaces that are coated with the polymerized LCST polymer. The invention is elucidated, without restriction, by the examples which follow. Example 1 (Version (a)) Modification of market-standard LCST polymers for immobilization In principle it is possible to react LCST polymers containing OH or NH2 groups with acryloyl chloride. The resulting modified LCST polymers contain double bonds via which they can be free-radically polymerized. The present example illustrates the modification of HOPEOPPOPEOOH copolymers. 20 g of a PEO-PPO-PEO block copolymer (4400 g/mol, 2 OH end groups; commercial product Synperonic® L121) are weighed out into a two-necked round-bottomed flask and mixed with 3 ml of triethylamine (1.2-fold excess) with the aid of a stirrer. The mixture is conditioned to about 10°C (waterbath). Using a dropping funnel, 2 ml (1.2-fold excess) of acryloyl chloride are slowly added dropwise, with vigorous stirring and cooling, in the course of which the temperature ought not to rise above 25 to 30°C. The vapors which form (HC1, a little acrylamide) are taken off into the waste-air system. The addition of the acryloyl chloride is followed by stirring, accompanied by cooling, until the evolution of heat and vapor is at an end (about 30 minutes) . For complete reaction of the acryloyl chloride, heating is then continued at 30 °C for 2 h more, with stirring, after which the mixture is cooled to room temperature and rinsed 3 times with water at room temperature and the product is isolated by centrifugation. The resulting product, with an LCST temperature of 8°C, can normally be used in the wet state; in other words, no further working up is normally necessary. The amount of polymer is determined as the solids content, and in the application the LCST polymer is used with a relative concentration of 5% to 10% by weight, based on solids content. The polymer can be dried under an oil-pump vacuum at a maximum of 35 to 40 °C, in order to prevent crosslinking. For complete drying it has proven appropriate to take up the polymer with ethanol and then to strip off the ethanol. Working up can also be carried out in the manner described for the reaction of PEONHPPONHPEO. In that case the polymer is dissolved in chloroform. The solution is extracted by shaking with, respectively, a little dilute HC1 solution, dilute NaOH solution and saturated NaCl solution. The organic phase is dried over sodium sulfate and the chloroform is removed on a rotary evaporator (waterbath Example 2 (Version (a)) The reaction of the block copolymer of Example 1 can also take place in accordance with the prior art by transesterification. This is done by mixing 1 mol of the polymer with up to 4 mol, preferably 2.4 mol, of methacrylate, or methyl acrylate. The ester can also be added in portions or continuously during the reaction. Further, the mixture is admixed with 0.1% to 5% by weight of transesterification catalyst (sulfuric acid, hydrochloric acid, p-toluenesulfonic acid, dodecyl- benzenesulfonic acid, alkali(ne earth) (hydr)oxides or metal alkoxides). The transesterification is carried out at liquid-phase temperatures of 80 to 120 °C. In order to prevent unwanted polymerizations the reaction is carried out advantageously in the presence of small amounts of commercially customary polymerization inhibitors (e.g., hydroquinone monoalkyl ethers, 2,6- di-t-butylphenol, N-nitrosamines, phenothiazine or phosphoric esters). These compounds are used in amounts of 0.01% to 2.0%, based on the mass of the acrylic ester. The product obtained has an LCST of 8°C. Example 3 (Version (a)) The procedure of Example 2 is repeated with the difference that 1 mol of the block copolymer is reacted with 2.4 mol of acrylic acid. The esterification is carried out in the presence of a solvent with which the water can be removed azeotropically, such as n-hexane, n-heptane and cyclohexane, or aromatics, such as benzene, toluene and the xylene isomers, and what are called special-boiling point spirits, which have boiling limits of between 70 and 140°C. The product obtained has an LCST of 8°C. Example 4 (Version (b)) The glycoluril-LCST polymers can be synthesized either in solution or in bulk. In both cases the products obtained are the same. Synthesis in solution: A reaction vessel is charged with 105 g of PEO/PPO block copolymer having a molecular weight of about 2000 g/mol; manufacturer: Sigma-Aldrich Chemie GmbH, Deisenhofen; 3 g of glycoluril Powderlink® 1174, manufacturer: Cytec Industries B.V., Neus; and 400 ml of toluene, and this initial charge is heated to 135°C under nitrogen, and traces of moisture are removed by azeotropic distillation. After an hour the reaction is initiated by adding 0.2 g of p-toluenesulfonic acid under a vacuum of 530 mbar and continuously adding fresh toluene dropwise. After about five hours 1.45 g of ethylene glycol are added. The reaction mixture is left to react under unchanged conditions for a further five hours. After the mixture has cooled, 2.8 g of triethylamine are added and 2.5 g of acryloyl chloride are added dropwise with cooling to 25-30oC. The reaction solution is poured into trays and dried to constant mass in a vacuum drying oven at a maximum of 50°C. The product obtained has an LCST of 8°C. Comparative Example The procedure of Example 4 (glycoluril version) was repeated with the difference that the last reaction step, namely the introduction of the polymerizable double bond into the polymer, was carried out not with acryloyl chloride but instead with 4-pentenoyl chloride (manufacturer: Sigma-Aldrich Chemie, Deisenhofen). In this case 3.26 g were used for the reaction in solution and 3.26 g of 4-pentenoyl chloride for the reaction in bulk; the other reactant proportions were not changed. The product obtained has an LCST of 0 to 2°C. Example 5 (Version (c)) a) Synthesis of PEO tosylate 25 g (33.3 mmol) of PEO monomethyl ether (750 g/mol) and 3.54 g (35 mmol) of triethylamine are dissolved in chloroform and the solution is cooled to about 0 to 5°C. 6.6? g (35 mmol) of tosyl chloride (in solution in chloroform) are added dropwise, and the solution is stirred at room temperature for about 15 h. The solution is extracted by shaking with, respectively, a little dilute HC1 solution and saturated NaCl solution. The organic phase is dried over sodium sulfate and the chloroform is removed on a rotary evaporator. b) Reaction of PEO tosylate (a) with PPO diamine to give PEONHPPONHPEO copolymer A round-bottomed flask is charged with the PEO tosylate (4.5 g/5 mmol) , the PPO diamine (2000 g/mol; 5 g/ 2.5 mmol) and 2 ml of triethylamine (excess, because of the boiling point of 89°C). The mixture is heated under reflux with vigorous stirring at 150°C for 3 h. The product is dissolved in chloroform and extracted by shaking with, respectively, a little water, dilute HC1 solution, dilute NaOH solution and saturated NaCl solution. The organic phase is dried over sodium sulfate and the chloroform (along with residual triethylamine) is removed on a rotary evaporator. c) Reaction of the PEONHPPONHPEO copolymer (b) with acryloyl chloride 3 g (0.86 mmol) of PEONHPPONHPEO copolymer and 0.15 g (1.71 mmol) of acryloyl chloride are dissolved in chloroform and the solution is cooled to about 10 to 15°C. 0.17 g (1.71 mmol) of triethylamine is added dropwise and the solution is stirred at room temperature for about 15 h. The solution is extracted by shaking with, respectively, a little dilute HC1 solution, dilute NaOH solution and saturated NaCl solution. The organic phase is dried over sodium sulfate and the chloroform is removed on a rotary evaporator (waterbath at 25°C). The products synthesized were analyzed by means of 1H NMR spectroscopy and GPC, the protons of the CH=CH2 group being clearly in evidence at between 5.5 and 6.5 ppm. The GPC elution diagrams showed the higher molar mass of the products as compared with the reactants. The products still, however, contained a reactant fraction with a lower molar mass. The LCST temperature of a 0.5% strength aqueous solution is 1 to 2°C; at higher polymer concentrations a slight turbidity is in evidence even at 0°C. Example 6 (Version (d)) Synthesis of N,N-diethylacrylamide LCST polymers a) Preparation of the initiator solution In a 2 1 three-necked flask with reflux condenser, on which a drying tube is mounted, and nitrogen feed line, 1000 ml of tetrahydrofuran, distilled a number of times over sodium, 40 g of naphthalene and 6 g of sodium chips are stirred at 20°C under an absolutely dry nitrogen atmosphere. Over the course of 2 h the sodium passes into solution to form the addition compound, which is deep green in color. The solution prepared is then 0.25 molar with respect to sodium. b) Implementation of the polymerization The operations below must likewise be carried out with careful exclusion of air and moisture. A 1 liter three-necked flask is charged under a pure nitrogen atmosphere with 300 ml of tetrahydrofuran freshly distilled over sodium. Then 20 ml of the naphthalene-sodium solution from a) are transferred to a dropping funnel mounted on the flask, and the final impurities in the flask are removed using a few drops of this solution. As soon as the green color is maintained, 500 ml of this 0.25 M solution are run in. Subsequently, with vigorous stirring and over the course of 30 minutes, a solution of 317 g of N,N- diethylacrylamide (2.5 mol) in 1000 ml of tetrahydrofuran is added dropwise. The solution immediately changes color. By means of external cooling the temperature is held at 15-20°C, and the N,N- diethylacrylamide added dropwise undergoes polymerization practically within a few seconds. After - the end of the addition of N, N-diethylacrylamide the polymerization is terminated by addition of an excess of 12 g of acryloyl chloride. The reaction mixture is worked up by adding 10 ml of methanol before the solvent is stripped off. The product obtained has an average molar mass of about 4700 g/mol and an LCST of about 39°C. Example 7 (Version (e)) Synthesis of N-vinylcaprolactam LCST polymers The polymerization of 348 g (2.5 mol) of N-vinylcapro- lactam takes place in the same way as that of the N,N- diethylacrylamide. The product obtained has an average molar mass of about 5700 g/mol and an LCST of about 32°C. Example 8 (Version (f)) Synthesis of methyl vinyl ether LCST polymers The polymerization of 145 g (2.5 mol) of methyl vinyl ether takes place in the same way as that of the N,N- diethylacrylamide. The sticky product obtained has an average molar mass of about 2500 g/mol and an LCST of 28 to 30°C. Use Examples 1 to 6 A pearlescent pigment (Iriodin Afflair® 504; manufacturer Merck KGaA, Darmstadt) is coated with the LCST polymers of product versions (a) to (f). An appropriate way of quickly investigating the effectiveness of the polymeric coating of particles has proven to be the use of platelet-shaped pearlescent pigments. Since the unmodified form is deposited relatively quickly in water, the improvement in stability as a result of treatment with the LCST polymer of the invention can be assessed within a short time. The altered color effects as well can easily be determined., Use Example 1 To treat Iriodin Afflair® 504 with the LCST polymer of Example 1 (version (a)) a 0.5% strength polymer solution is used. The pigment (10% by weight) is dispersed in water at 800 rpm for 15 minutes. The dispersion is subsequently cooled to a temperature of 0.5°C. Following the addition of the polymer solution the pigment is coated with the polymer at 11°C for 30 minutes and the precipitated polymer is then cross- linked for 3 h. The initiator system used is, per gram of polymer, 0.8 g of sodium pyrosulfite, 0.4 g of iron (II) sulfate and 0.8 g of potassium peroxodisulfate. The polymer concentration, based on pigment, was 5% by weight. Use Example 2 In a similar way, Iriodin Afflair® is treated with the LCST polymer of Example 4 (version (b)), the temperature of the pigment dispersion being raised from 0.5°C to 11°C in order to coat the pigment. The polymer layer is crosslinked using the polymerization initiator of Use Example" 1 over a period of 3 h. Use Example 3 In a similar way, Iriodin Afflair® 504 is treated with the LCST polymer of Example 5 (version (c)), the temperature of the pigment dispersion being raised from 0.5°C to 11°C in order to coat the pigment. The polymer layer is crosslinked using the polymerization initiator of Use Example 1 over a period of 3 h. Use Example 4 In a similar way, Iriodin Afflair® 504 is treated with the LCST polymer of Example 6 (version (d)), the temperature of the pigment dispersion being raised from 10°C to 50°C in order to coat the pigment. The polymer layer is crosslinked using the polymerization initiator of Use Example 1 over a period of 3 h. Use Example 5 In a similar way, Iriodin Afflair® 504 is treated with the LCST polymer of Example 7 (version (e)), the temperature of the pigment dispersion being raised from 10°C to 40°C in order to coat the pigment. The polymer layer is crosslinked using the polymerization initiator of Use Example 1 over a period of 3 h. Use Example 6 In a similar way, Iriodin Afflair® 504 is treated with the LCST polymer of Example 8 (version (f)), the temperature of the pigment dispersion being raised from 10°C to 48°C in order to coat the pigment. The polymer layer is crosslinked using the polymerization initiator of Use Example 1 over a period of 3 h. Use Example 7 (comparative) In a similar way, Iriodin Afflair® 504 is treated with the LCST polymer of the comparative example, the temperature of the pigment dispersion being raised from about 0°C to 5°C in order to coat the pigment. The polymer layer is crosslinked using the polymerization initiator of Use Example 1 over a period of 3 h. The stabilizing effect of the treatment of the pigment with the LCST polymer was assessed according to the sedimentation behavior, by monitoring the settling behavior of the 0.5% by weight pigment dispersion in water. The results of these investigations are depicted in Figures 1 and 2. Figures 1 and 2 show that both the untreated pigment and the pigment treated with the comparison polymer had settled to a high extent after 60 minutes, whereas the pigment treated with the LCST polymers of the invention showed only slight settling. The treated pigments were incorporated into a 2- component hydroacrylic-melamine varnish at a concentration of 10% by weight, based on the solids content, by dispersion (peripheral speed 4 m/s, 15°C, 10 min) and investigated for their color properties using an MA 68 Multi-Angle Spectrophotometer colorimeter from X-Rite. The results of these investigations are summarized in Table I. The figures given in Table I were based on the untreated pigment as reference. The state of dispersion and the orientation of the platelet-shaped effect pigments play a distinct role at low viewing angles. It is clearly apparent that the LCST treatment has a positive outcome for the color properties (lightness, hue) of the effect pigment. This can be attributed to the better state of dispersion and the flatter orientation of the pigment particles. The figures reported for AL, Aa and Ab in the inventive examples in Table 1 can be attributed to the orientation of the pigment particles. The pigment treated with the polymer from the comparative example, in contrast, showed lower orientation figures, which are comparable with the figures for the untreated pigment. Use Example 8 A semiconductor wafer with a silicon dioxide surface measuring 1 * 1 cm is immersed in 3 ml of distilled water. The system is cooled to 2°C and 0.2 ml of a 10% strength by weight LCST polymer solution of Example 1 is added. After two hours at 2°C the system is heated to 23°C over the course of an hour. Thereafter it is cooled to 2°C again, though only for a period of 10 minutes, and within an hour is heated to 23°C. This cycle of cooling and heating is carried out a total of three times. After the final cycle the wafer remains at 23 °C in the liquid coating medium for 24 hours and thereafter is rinsed off with distilled water. The polymer layer is subsequently crosslinked under thermal induction; for this purpose the wafer is heated in a drying oven at temperatures of 70 - 100°C for 5 hours. Another possibility for crosslinking the polymer layer is to irradiate the coated wafer with intense visible light for 5 hours. In a similar way the silicon wafer is treated with the LCST polymer of Examples 4 and 5, the temperature range of the polymer solution in the coating operation extending from 2°C to 23°C. The crosslinking operation takes place in the same way as for the polymer of Example 1. In a similar way the silicon wafer is treated with the LCST polymers of Examples 6 to 8, the temperature range of the polymer solution in the coating operation extending from 10°C to 50°C, 10°C to 40°C and 10°C to 48°C, respectively. The crosslinking operation takes place in the same way as for the polymer of Example 1. The semiconductor wafer coated by the process described above with the LCST polymer now possesses a more strongly hydrophobic surface than a wafer without the coating. This can be documented experimentally by means of water droplets applied to the surface. The coated and therefore more hydrophobic surface is wetted less effectively by water than the unmodified surface. The water droplet beads off from the coated wafer; on the unmodified surface the droplet spreads out. WE CLAIM: 1. An LCST polymer of the general formula in which R1 (identical or different at each occurrence) is hydrogen or a methyl group, X1 and X2 = -O—, —S— or —NH— and X1 additionally is a single bond if the first atom R2 is one of the radicals indicated below: a) a copolymer radical (Cop) containing at least two structural units —(—O—C2H4)n— (ethylene oxide = EO) and -(—O—C3H6—)n— (propylene oxide = PO) or —(—O—C4H8)n— (butylenes oxide = Bu) and —(—O—CH2—)n— (methylene oxide = MeO) in a molar ratio of 5 to 95 : 95 to 5, in which n (identical or different for each structural unit) is approximately 1 to 1000; in which R is an alkyl group, r = (identical or different at each occurrence) 1 to 1000 and s = 1 to 500); in which o = 10 to 4000 and R3 (identical or different at each occurrence) is hydrogen or alkyl groups having 1 to 5 carbon atoms; in which p= 5 to 2000; or 2. The LCST polymer as claimed in claim 1, wherein the -(C3H6)— radical in (a) and (c) is an isopropylene radical and the radical —(C4H8)— in (a) is an isobutylene radical. 3. The LCST polymer as claimed in claim 1, wherein the structural units -(EO)- and -(PO)- on the one hand and the structural units -(BuO)- and -(MeO)- on the other hand are present in (a) in blocks withn= 1 to 1000. 4. The LCST polymer as claimed in claim 3, wherein the blocks with the structural units -(PO)- and -(BuO)- are disposed between the blocks with the structural units -(EO)- and -(MeO)-, respectively. 5. A process for preparing an LCST polymer as claimed in any one of claims 1 to 4 (versions (a) to (c)), wherein a compound of the general formula HO-[R2]—OH, in which R2 is as defined in claim 1, is reacted with a compound of the formula in which R1 is as defined in claim 1 and X is OH, halogen, preferably chlorine, an acid group, an acrylic group or a lower alkoxy group, in a molar ratio of 1 : 1 to 1 : 4, especially 1:2. 6. A process for preparing an LCST polymer as claimed in claim 1 (version c), wherein p-toluenesulfonyl chloride is reacted with a polyethylene oxide methyl ester of the formula H—[EO]r— OCH3, in which r is as defined in claim 1 (c), to give a polyethylene oxide tosylate, this tosylate is reacted with (NH2)-C3H6-[—PO—]s—NH2, in which s is as defined in claim 1 (c), to give H—[EO}— NH—(PO)—NH—(EO) — OH, and this is reacted with (a) in which R1 is as defined in claim 1 and X is as defined in claim 5, or (b) with the anhydride of the corresponding acid. 7. A process for coating particles and nonparticulate substrate surfaces wherein particles or nonparticulate substrate surfaces are provided and said particles or nonparticulate substrate surfaces are coated with an LCST polymer as claimed in any one of claims 1 to 4 or prepared according to claim 5 or 6. 8. The process as claimed in claim 7, wherein the LCST polymer is contacted in a liquid below the LCST temperature such as herein described with the particles or the nonparticulate substrate surfaces, the temperature is raised to above the LCST temperature, and the polymers are polymerised via the double bonds at this temperature or a higher temperature on the surface of the particles or on the nonparticulate substrate surfaces. 9. Particles or nonparticulate substrate surfaces coated with a polymerised LCST polymer as claimed in any one of claims 1 to 4. Disclosed polymers of the general formula (I), wherein R1 (identical or differently) represents hydrogen or a methyl group, X1 and X2 = -O-, -S- or -NH-, X1 additionally representing a single bond if the first atom in R2 is not a C atom, and R2 represents one of the following radicals : a) a copolymer radical (Cop) containing at least two structural units -(-O- C2H4)n- (ethylene oxide - EO) and -(-O-C3H6-)n- (propylene oxide = PO) or -(-O-C4H8)n- (butylene oxide = BuO) and -(-O-CH2-)n- (methylene oxide = MeO) at a molar ratio of 5 to 95 : 95 to 5, n representing approximately 1 to 1000 (identically or differently for each structural unit); b) formula (II), wherein Cop represents a copolymer radical as defined in (a), and x = 1 to 5 and y = 1 to 20; c) formula (HI), wherein R represents an alkyl group, r = (identically or differently) 1 to 1000 and s = 1 to 500; d) formula (IV) wherein o = 10 to 4000 and R3 (identically or differently) represents hydrogen or alkyl groups comprising 1 to 5 carbon atoms; e) formula (V), wherein p = 5 to 2000; or formula (VI), wherein f) formula (VI), wherein q = 10 to 4000. Also disclosed are methods for the production thereof and the use thereof for coating particles and non-particulate substrate surfaces.

Full Text

LCST POLYMER HAVING TERMINAL (METH) ACRYLIC ACID GROUPS AND
PROCESS FOR PREPARING THE SAME
Description
15The invention relates to LCST (lower critical solution
temperature) polymers. This term is used to refer to
polymers which are soluble in a liquid medium at a low
temperature but above a certain temperature (the LCST
temperature) precipitate from the liquid medium. LCST
20polymers have different chemical compositions. The
best-known LCST polymers are polyalkylene oxide
polymers, examples being polyethylene oxide (PEO) or
polypropylene oxide (PPO) polymers, but also (PEO)-
(PPO) copolymers, particularly PEO-PPO-PEO block
25copolymers. Other LCST polymers are poly(N-isopropyl-
acrylamide)-ethyl-(hydroxyethyl)-cellulose derivatives,
poly(N-vinylcaprolactam) derivatives and poly(methyl
vinyl ether) derivatives.
30The first-mentioned polymers are described for example
in WO 01/60926 Al. That publication relates to a
process for coating substrate surfaces (particle
surfaces and nonparticulate substrate surfaces) with
LCST polymers, for which an LCST polymer is dissolved
35in a solvent at a temperature below the LCST
temperature, this solution is mixed with the substrate
surfaces to be coated, and the resultant mixture is
heated to above the LCST temperature until the
deposition of LCST polymers on the substrate surfaces
begins. The deposited LCST polymer can be immobilized
by providing it with functional groups which allow
substantially irreversible adsorption on the substrate
surface. The functional groups may be selected from
acid groups, hydroxyl groups, amino groups, phosphate
groups, mercaptan groups, siloxane groups or
hydrophobic groups. Further, the LCST polymers may be
provided with functional groups which, following
deposition of the LCST polymers on the particles, allow
the crosslinking of the LCST polymers in a crosslinking
reaction. Functional groups of this kind may be
selected from carboxylic acid group derivatives,
chloroformate groups, amino groups, isocyanate groups,
oxirane groups and/or free-radically crosslinkable
groups, with the crosslinking reaction being initiated,
inter alia, by a change in the pH of the solution.
Free-radical crosslinking is less preferred than cross-
linking through a change in pH. The examples specify
merely the enveloping of various pigment particles
(TiO2, Fe2O3, Cu phthalocyanine blue, and semiconductor
wafers with a silicon dioxide surface) with PEO-PPO-PEO
block copolymers. Fixing of the copolymersdeposited on
the substrate surfaces is not elucidated.
The use of LCST polymers for enveloping superpara-
magnetic particles is known, further, from WO 97/45202.
These particles comprise a core of a first polymer, an
inner layer of a second polymer, which coats the core
and in which a magnetic material is dispersed, and an
outer layer of a third polymer, which coats the
magnetic layer and is capable of reacting at least one
biological molecule, the second polymer at least being
heat-sensitive and having an LCST temperature of 15 to
65°C. The second polymer is obtained preferably by
polymerizing (1) a water-soluble acrylamide monomer,
such as N-isopropylacrylamide (NIPAM), (2) at least one
crosslinking agent, such as N,N-methylenebisacrylamide
and (3) at least one functional cationic and water-
soluble monomer different than the monomer (1), e.g.,
the chloride of 2-aminoethyl methacrylate. A further
preferred polymer is [poly(N-isopropylacrylamide)]
(PNIPAM).
Patent Abstracts of Japan, Vol. 009 No. 188 (C295)
(1985) page 107 = JP 60 058 237 A describes the
encapsulation of inorganic particles. The aim is to
prepare a stable particle dispersion. The inorganic
particles are suspended in water and contacted below
the LCST temperature with an aqueous solution of the
LCST polymer. When the temperature of the resulting
system is raised, a layer of the LCST polymer is
deposited on the inorganic particles. The resultant
particle suspension is admixed with a free-radically
polymerizable monomer, an initiator and, if desired, an
emulsifier, and an emulsion polymerization is carried
out, giving encapsulated particles. Now, additionally,
there is an outer layer, consisting of the polymerized
monomer layer; accordingly, the function of the LCST
polymer layer is only to facilitate, the penetration of
monomer residues.
The polymerizable monomer, then, is reacted with the
LCST polymer that is already on the particles, or the
water-soluble polymer is enveloped with a layer of the
polymer obtained from the polymerizable monomer. This
process has the disadvantage that the graft attachment
takes place only on the active centers of the pre-
deposited LCST polymer, and so the envelopment is
nonuniform and heterogeneous and does not constitute a
complete barrier.
Moreover, it is necessary to add a monomer to the
dispersion of the coated particles in order to initiate
crosslinking. In the majority of cases the monomer is
never fully consumed, and so a certain fraction of the
monomer remains in the crosslinked structure.
Subsequent emission of the "dissolved" monomers from
the polymer is undesirable, since the monomer is
injurious to health.
Furthermore, disadvantages in the coating system are
anticipated as a result of the detachment of the
copolymerized emulsifier if the pigment comes into
contact with solvents.
WO 92/20441 describes a process for generating
encapsulated particles, the particles comprising a core
surrounded by a coacervate coating. In this process an
aqueous solution of an LCST polymer is contacted, at a
temperature of reversible insolubilization (TRI), of
Tl, with a dispersion of the particles at a temperature
of T2, which is lower than Tl, and then the dispersion
is heated to a temperature above Tl, thereby depositing
the LCST polymer as a coacervate around the particles.
Subsequently an agent for lowering the TRI is added to
the solution, thereby lowering the TRI of the LCST
polymer in the solution to a temperature T3, which is
lower than Tl, and then either the dispersion is cooled
to a temperature between T3 and Tl and is held at this
temperature, or the particles are separated from the
dispersion at a temperature of more than T3. As agents
for lowering the TRI it is possible to use electrolytes
and water-miscible organic liquids in which the LCST
polymer is not soluble.
LCST polymers used are preferably synthetic polymers
(homopolymers or copolymers) with hydrophilic monomers.
Suitable LCST monomers are acrylic or vinyl compounds.
Where LCST copolymers are used, the comonomer is
commonly hydrophilic and may be nonionic or ionic.
Suitable nonionic monomers are certain aryl or vinyl
compounds. Examples of anionic or cationic monomers are
acrylic acid derivatives or dialkylaminoalkyl
acrylates. These compounds, however, are already
saturated at the ends, and so crosslinking reactions
are no longer possible.
LCST polymers are also known, for example, from
EP 0 629 649 Al. They are used as rheofluidizing
additives and antisettling agents in diaphragm wall
construction, for wells in the oil industry, and as
hydraulic fluids and lubricants.
EP 0 718 327 A2 discloses universally compatible
pigment dispersants composed of methyl methacrylate and
an acrylate or methacrylate. These polymers, however,
serve only for dispersing pigments, but not for
enveloping pigments.
The object on which the invention was based was to
provide LCST polymers which on cooling no longer detach
from a substrate surface but instead remain firmly
joined to it. The polymers are therefore intended to be
used without added emulsifiers or monomers, so that no
additives can leach from the defined polymer layer.
This object is achieved in accordance with the
invention by means of LCST polymers of the general
formula:

in which Rx (identical or different at each occurrence)
is hydrogen or a methyl group, X1 and X2 (identical to
or different from one another) = -O-, -S- or -NH- and Xx
additionally is a single bond if the first atom in R2 is
not a carbon atom, and R2 is one of the radicals
indicated below:
a) a copolymer radical (Cop) containing at least two
structural units -(-O-C2H4)n- (ethylene oxide = EO)
and - (-O-C3H6-)n- (propylene oxide = PO) or -(-O-
C4H8)n- (butylene oxide = BuO) and -(-O-CH2-)n-
(methylene oxide = MeO) in a molar ratio of 5 to
95:95 to 5, in which n (identical or different for
each structural unit) is approximately 1 to 1000;

in which Cop is a copolymer radical as defined in (a) ,
x = 1 to 5 and y = 1 to 20;

in which R is an alkyl group, r = (identical or
different at each occurrence) 1 to 1000 and s = 1 to
500;
d)

in which o = 10 to 4000 and R3 (identical or different
at each occurrence) is hydrogen or alkyl groups having
1 to 5 carbon atoms;

in which q = 10 to 4000.
It has surprisingly been found that the polymers of the
invention are irreversibly immobilized on the substrate
surface after polymerization on the acrylic or
methacrylic side chain. The immobilization is far
greater than that of LCST polymers in which the end
groups are composed, for example, of simple vinyl
groups or other groups with double bonds.
Other polymerized units, such as vinylacetic acid,
oleic acid, fumaric acid, maleic acid and polyethylene
glycol monovinyl ether, are less suitable as end
groups.
The polymers of the invention commonly have an LCST in
the range from 0 to 70°C, which is dependent on factors
including the following:
molar ratio of the hydrophobic and hydrophilic
fractions of the LCST polymer,
- molar mass of the LCST polymer,
number of polymerizable and ionisable groups,
concentration of the polymer,
pH and ionic strength of the medium.
The LCST polymers are composed of polar and nonpolar or
hydrophilic and hydrophobic segments. The LCST can be
tailored by varying these individual segments and also
the overall chain length.
Following the polymerization with the acrylic or
methacrylic end groups, the LCST polymers of the
invention can be used as dispersants fixed on the
substrate surfaces. Among other things, this makes the
expensive step of pigment dispersion cheaper, since the
pigment carries its dispersant with it. Further, the
pigments thus coated form agglomerates to a lesser
extent than do untreated pigments, so that dispersion
is easier to carry out, resulting in an additional
reduction in costs.
Dispersants are surface-active substances which
facilitate the dispersion of a pulverulent substance,
e.g., a pigment or filler, in a liquid dispersion
medium, by lowering the surface tension between two
components. In the course of pigment grinding they
thereby facilitate the mechanical disruption of the
secondary particles which are present in the form of
agglomerates, into primary particles. Moreover, they
protect the primary particles formed from
reagglomeration or flocculation by virtue of complete
wetting and the formation of a protective colloid shell
or an electrochemical double layer.
Since the LCST polymers of the invention are
transparent or transluscent in visible light, they are
able to form a complete envelope around particles,
without the color of the particles themselves being
affected. Further, in paints, the pigments thus coated
display the full color strength, since by virtue of the
LCST polymer coating they do not form agglomerates.
Preferred LCST polymers fall into groups (a) and (c) .
Preferably the radical -(C3H6)- radical in (a) and (c)
is an isopropyl radical and the radical (C4H8)- in (a)
is an isobutyl radical.
The preferred LCST polymers in group (a) are block
copolymers, the structural units -(EO)- and -(PO)- on
the one hand and the structural units -(BuO)- and
- (MeO) - on the other hand being present in blocks with
n = 3 to 100.
Block copolymers are composed of blocks of
homosequences linked to one another via the ends. Graft
polymers are composed of what is called a homopolymeric
backbone, from which polymer chains of other
homopolymers branch out.
The blocks with the structural units -(-PO)- and
-(-BuO-)- are preferably disposed between the blocks
with the structural units -(-EO)- and -(-MeO-),
respectively.
These block copolymers are referred to for the sake of
simplicity as PEO-PPO-PEO block copolymers. A triblock
copolymer having the block sequence PEO-PPO-PEO
customarily has a PEO weight fraction of about 5% to
85% by weight and number-average molar masses (MN) of
200 to 50,000 g/mol.
Alternatively, the different structural units can be
randomly distributed.
The molar ratio between the -(EO)- structural units and
-(PO)- structural units is preferably about 10 to 60 :
40 to 90.
The LCST polymers of the invention of versions (a) to
(f) can be prepared by reacting a compound of the
general formula HO-[R2]-OH, in which R2 is as defined
above, with a compound of the formula

in which R1 is as defined above and X is OH, halogen,
preferably chlorine, or a lower alkoxy group, in a
molar ratio of 1:2, or (b) with the anhydride of the
corresponding acid in a molar ratio of 1:1.
The starting polymers for the LCST polymers of product
versions (a) to (c) are in some cases available commer-
cially. Additionally, however, they can be prepared as
follows:
For version (a):
The copolymers can be prepared by starting from a
compound which is already present in macromolecular
form and continuing the polymerization using a polymer
of a different kind. The polymerization may take place
either in solution in water or in an organic solvent,
in emulsion or suspension or by direct reaction of the
components in bulk or in powder form in the melt, with
or without a catalyst, preferably in a one-stage
process.
For version (b) :
These copolymers are star-shaped and contain as their
central linking unit a glycoluril group. They can be
prepared as follows:
A glycouril unit (Powderlink 1774) is reacted with PEO
methyl ether and PPO butyl ether so as to link one or
more PEO units to one or more PPO units.
Compounds of this kind and their use for coating
substrate surfaces, such as pigments, are described for
example in the following publications: DE 100 38 147
Al, DE 100 64 240.3 and DE 101 63 985.6.
For version (c):
The copolymers are prepared with the aid of tosylates.
As a result it is possible to link the OH-terminated
polyethers (PEO/PPO) with amines. The polyethers are
reacted in this case with tosyl chloride (p-toluene-
sulfonyl chloride), giving polyether tosylates. Since
the tosyl group is a very good leaving group, the
polyether tosylates can be reacted with primary amines.
Thus it is possible, by way of an aliphatic or aromatic
diamine, to link, for example, a PEO unit with a PPO
unit. Another possibility is the reaction of PPO
diamine with PEO tosylate. In this way a three-block
copolymer is obtained. In order to prevent advancement
reactions, which would result in undefined products,
the polyethers ought to contain only one free OH group.
For versions (d) to (f) the corresponding monomers are
used.
The LCST polymers of the invention can be used for
coating particles and nonparticulate substrate
surfaces. The particles that are suitable in accordance
with the invention include pigments, fillers, and nano-
particles. Pigments are pulverulent or platelet-shaped
colorants which in contrast to dyes are insoluble in
the surrounding medium (DIN 55943: 1993-11, DIN:EN 971-
1: 1996-09). Pigments influence or determine the
coloring and for reasons of cost are used in as small
amounts as possible. Owing to forces of interaction it
is possible for the pigment particles to agglomerate,
particularly during incorporation into the matrix
material. This results for example, in quality
detractions in the resulting paint, as a consequence,
inter alia, of deficient color strength, sedimentation
or phase separation.
Preferred pigments are titanium dioxide, iron oxide,
zinc oxide:, carbon black, Cu phthalocyanine pigments,
platelet-shaped pigments, such as mica (with or without
oxidic and metallic coatings) or aluminum. Fillers
which can be used include, for example, barium sulfate
and talc. Nanoparticles which can be used include iron
oxide, titanium dioxide and silicon dioxide particles.
The particles also include microfibers, such as glass,
carbon, textile and polymer fibers.
The substrate surfaces may also be nonparticulate
surfaces, such as those of glass, metal and
semiconductors, for example. Particularly preferred
surfaces are silicon dioxide wafers which are used in
the semiconductors industry.
The LCST polymers of the invention are preferably
contacted in a liquid medium (e.g., in an aqueous or
organic medium) at below the LCST temperature with the
particles or the nonparticulate substrate surfaces, and
then the temperature is raised to above the LCST
temperature and the polymers are polymerized by the
double bonds at this temperature or a higher
temperature on the surface of the particles or on the
nonparticulate substrate surfaces.
The synthesis of product version (a) takes place by
reacting commercially available PEO-PPO-PEO block
copolymers which have terminal OH groups with acrylic
or methacrylic acid derivatives, thereby introducing
polymerizable double bonds. The introduction can take
place by means of the following derivatives: chlorides,
esters, anhydrides, amides or free acids, and is
acidically or basically catalyzed. This esterification
or transesterification can be carried out in a solvent
at about 0 to 100°C, but can also be carried out in
bulk (without solvent). In order to inhibit unwanted
polymerization, small amounts of a polymerization
inhibitor are added to the reaction mixture.
The synthesis of product version (b) takes place by
reacting the polyether-modified glycoluril with
acryloyl or methacryloyl chloride, thereby introducing
polymerizable double bonds. This reaction can be
carried out in a solvent at about 0 to 30°C, but can
also be carried out in bulk (without solvent). One
possibility of introducing a double bond is to react
the product mixture, which ought to contain at least
two PEO/PPO segments, with ethylene glycol. After the
reaction of the first OH group with the glycoluril
unit, the second free OH group of the ethylene glycol
is sterically shielded by the polymer chains, and so
there ought not to be any reaction with the second
glycoluril unit. The free OH group that remains can
then be reacted with compounds possessing less steric
bulk, such as with acryloyl chloride, for example.
The synthesis of product version (c) takes place by
reacting the 3-block copolymer, obtained with a
tosylate method, on the NH group with acryloyl or
methacryloyl chloride, giving polymers containing
polymerizable acrylic or methacrylic double bonds.
Via this synthesis route it has been possible to link a
PPO diamine (2000 g/mol) with PEO (750 g/ml) and to
introduce double bonds with acryloyl chloride. In the
reaction of PEO tosylate with PPO diamine the
temperatures are about 150°C. The precise synthesis
instructions are given in Example 5.
The synthesis of product version (d) to (f) takes place
by an anionic polymerization of the corresponding
monomers in solution. In this case a sodium-naphthalene
solution serves as initiator. As a result of the use of
this initiator system, electron transfer to a fraction
of the monomers results in the formation of what are
referred to as free-radical anions. The free-radical
anions formed combine very rapidly to form dianions,
and so chain growth will take place on two sides.
An advantage of this polymerization process is that the
resulting polymer has a very narrow molar mass
distribution. This can be influenced and predicted
through the choice and composition of the reactants.
The polymerization is terminated with electrophilic
substances. The addition of acryloyl chloride or
methacryloyl chloride to the reaction solution not only
results in the ending of the polymerization but at the
same time introduces the acrylic or methacrylic end
group.
The invention further provides particles or
nonparticulate substrate surfaces that are coated with
the polymerized LCST polymer.
The invention is elucidated, without restriction, by
the examples which follow.
Example 1
(Version (a))
Modification of market-standard LCST polymers
for immobilization
In principle it is possible to react LCST polymers
containing OH or NH2 groups with acryloyl chloride. The
resulting modified LCST polymers contain double bonds
via which they can be free-radically polymerized.
The present example illustrates the modification of
HOPEOPPOPEOOH copolymers.
20 g of a PEO-PPO-PEO block copolymer (4400 g/mol, 2 OH
end groups; commercial product Synperonic® L121) are
weighed out into a two-necked round-bottomed flask and
mixed with 3 ml of triethylamine (1.2-fold excess) with
the aid of a stirrer. The mixture is conditioned to
about 10°C (waterbath). Using a dropping funnel, 2 ml
(1.2-fold excess) of acryloyl chloride are slowly added
dropwise, with vigorous stirring and cooling, in the
course of which the temperature ought not to rise above
25 to 30°C. The vapors which form (HC1, a little
acrylamide) are taken off into the waste-air system.
The addition of the acryloyl chloride is followed by
stirring, accompanied by cooling, until the evolution
of heat and vapor is at an end (about 30 minutes) . For
complete reaction of the acryloyl chloride, heating is
then continued at 30 °C for 2 h more, with stirring,
after which the mixture is cooled to room temperature
and rinsed 3 times with water at room temperature and
the product is isolated by centrifugation.
The resulting product, with an LCST temperature of 8°C,
can normally be used in the wet state; in other words,
no further working up is normally necessary. The amount
of polymer is determined as the solids content, and in
the application the LCST polymer is used with a
relative concentration of 5% to 10% by weight, based on
solids content.
The polymer can be dried under an oil-pump vacuum at a
maximum of 35 to 40 °C, in order to prevent
crosslinking. For complete drying it has proven
appropriate to take up the polymer with ethanol and
then to strip off the ethanol. Working up can also be
carried out in the manner described for the reaction of
PEONHPPONHPEO. In that case the polymer is dissolved in
chloroform. The solution is extracted by shaking with,
respectively, a little dilute HC1 solution, dilute NaOH
solution and saturated NaCl solution. The organic phase
is dried over sodium sulfate and the chloroform is
removed on a rotary evaporator (waterbath Example 2
(Version (a))
The reaction of the block copolymer of Example 1 can
also take place in accordance with the prior art by
transesterification. This is done by mixing 1 mol of
the polymer with up to 4 mol, preferably 2.4 mol, of
methacrylate, or methyl acrylate. The ester can also be
added in portions or continuously during the reaction.
Further, the mixture is admixed with 0.1% to 5% by
weight of transesterification catalyst (sulfuric acid,
hydrochloric acid, p-toluenesulfonic acid, dodecyl-
benzenesulfonic acid, alkali(ne earth) (hydr)oxides or
metal alkoxides). The transesterification is carried
out at liquid-phase temperatures of 80 to 120 °C. In
order to prevent unwanted polymerizations the reaction
is carried out advantageously in the presence of small
amounts of commercially customary polymerization
inhibitors (e.g., hydroquinone monoalkyl ethers, 2,6-
di-t-butylphenol, N-nitrosamines, phenothiazine or
phosphoric esters). These compounds are used in amounts
of 0.01% to 2.0%, based on the mass of the acrylic
ester. The product obtained has an LCST of 8°C.
Example 3
(Version (a))
The procedure of Example 2 is repeated with the
difference that 1 mol of the block copolymer is reacted
with 2.4 mol of acrylic acid. The esterification is
carried out in the presence of a solvent with which the
water can be removed azeotropically, such as n-hexane,
n-heptane and cyclohexane, or aromatics, such as
benzene, toluene and the xylene isomers, and what are
called special-boiling point spirits, which have
boiling limits of between 70 and 140°C. The product
obtained has an LCST of 8°C.
Example 4
(Version (b))
The glycoluril-LCST polymers can be synthesized either
in solution or in bulk. In both cases the products
obtained are the same.
Synthesis in solution:
A reaction vessel is charged with 105 g of PEO/PPO
block copolymer having a molecular weight of about
2000 g/mol; manufacturer: Sigma-Aldrich Chemie GmbH,
Deisenhofen; 3 g of glycoluril Powderlink® 1174,
manufacturer: Cytec Industries B.V., Neus; and 400 ml
of toluene, and this initial charge is heated to 135°C
under nitrogen, and traces of moisture are removed by
azeotropic distillation. After an hour the reaction is
initiated by adding 0.2 g of p-toluenesulfonic acid
under a vacuum of 530 mbar and continuously adding
fresh toluene dropwise. After about five hours 1.45 g
of ethylene glycol are added. The reaction mixture is
left to react under unchanged conditions for a further
five hours.
After the mixture has cooled, 2.8 g of triethylamine
are added and 2.5 g of acryloyl chloride are added
dropwise with cooling to 25-30oC. The reaction solution
is poured into trays and dried to constant mass in a
vacuum drying oven at a maximum of 50°C. The product
obtained has an LCST of 8°C.
Comparative Example
The procedure of Example 4 (glycoluril version) was
repeated with the difference that the last reaction
step, namely the introduction of the polymerizable
double bond into the polymer, was carried out not with
acryloyl chloride but instead with 4-pentenoyl chloride
(manufacturer: Sigma-Aldrich Chemie, Deisenhofen). In
this case 3.26 g were used for the reaction in solution
and 3.26 g of 4-pentenoyl chloride for the reaction in
bulk; the other reactant proportions were not changed.
The product obtained has an LCST of 0 to 2°C.
Example 5
(Version (c))
a) Synthesis of PEO tosylate
25 g (33.3 mmol) of PEO monomethyl ether (750 g/mol)
and 3.54 g (35 mmol) of triethylamine are dissolved in
chloroform and the solution is cooled to about 0 to
5°C. 6.6? g (35 mmol) of tosyl chloride (in solution in
chloroform) are added dropwise, and the solution is
stirred at room temperature for about 15 h. The
solution is extracted by shaking with, respectively, a
little dilute HC1 solution and saturated NaCl solution.
The organic phase is dried over sodium sulfate and the
chloroform is removed on a rotary evaporator.
b) Reaction of PEO tosylate (a) with PPO diamine to
give PEONHPPONHPEO copolymer
A round-bottomed flask is charged with the PEO tosylate
(4.5 g/5 mmol) , the PPO diamine (2000 g/mol; 5 g/
2.5 mmol) and 2 ml of triethylamine (excess, because of
the boiling point of 89°C). The mixture is heated under
reflux with vigorous stirring at 150°C for 3 h. The
product is dissolved in chloroform and extracted by
shaking with, respectively, a little water, dilute HC1
solution, dilute NaOH solution and saturated NaCl
solution. The organic phase is dried over sodium
sulfate and the chloroform (along with residual
triethylamine) is removed on a rotary evaporator.
c) Reaction of the PEONHPPONHPEO copolymer (b) with
acryloyl chloride
3 g (0.86 mmol) of PEONHPPONHPEO copolymer and 0.15 g
(1.71 mmol) of acryloyl chloride are dissolved in
chloroform and the solution is cooled to about 10 to
15°C. 0.17 g (1.71 mmol) of triethylamine is added
dropwise and the solution is stirred at room
temperature for about 15 h. The solution is extracted
by shaking with, respectively, a little dilute HC1
solution, dilute NaOH solution and saturated NaCl
solution. The organic phase is dried over sodium
sulfate and the chloroform is removed on a rotary
evaporator (waterbath at 25°C).
The products synthesized were analyzed by means of 1H
NMR spectroscopy and GPC, the protons of the CH=CH2
group being clearly in evidence at between 5.5 and
6.5 ppm. The GPC elution diagrams showed the higher
molar mass of the products as compared with the
reactants. The products still, however, contained a
reactant fraction with a lower molar mass. The LCST
temperature of a 0.5% strength aqueous solution is 1 to
2°C; at higher polymer concentrations a slight
turbidity is in evidence even at 0°C.
Example 6
(Version (d))
Synthesis of N,N-diethylacrylamide LCST polymers
a) Preparation of the initiator solution
In a 2 1 three-necked flask with reflux condenser, on
which a drying tube is mounted, and nitrogen feed line,
1000 ml of tetrahydrofuran, distilled a number of times
over sodium, 40 g of naphthalene and 6 g of sodium
chips are stirred at 20°C under an absolutely dry
nitrogen atmosphere. Over the course of 2 h the sodium
passes into solution to form the addition compound,
which is deep green in color. The solution prepared is
then 0.25 molar with respect to sodium.
b) Implementation of the polymerization
The operations below must likewise be carried out with
careful exclusion of air and moisture.
A 1 liter three-necked flask is charged under a pure
nitrogen atmosphere with 300 ml of tetrahydrofuran
freshly distilled over sodium. Then 20 ml of the
naphthalene-sodium solution from a) are transferred to
a dropping funnel mounted on the flask, and the final
impurities in the flask are removed using a few drops
of this solution. As soon as the green color is
maintained, 500 ml of this 0.25 M solution are run in.
Subsequently, with vigorous stirring and over the
course of 30 minutes, a solution of 317 g of N,N-
diethylacrylamide (2.5 mol) in 1000 ml of
tetrahydrofuran is added dropwise. The solution
immediately changes color. By means of external cooling
the temperature is held at 15-20°C, and the N,N-
diethylacrylamide added dropwise undergoes
polymerization practically within a few seconds. After
- the end of the addition of N, N-diethylacrylamide the
polymerization is terminated by addition of an excess
of 12 g of acryloyl chloride. The reaction mixture is
worked up by adding 10 ml of methanol before the
solvent is stripped off. The product obtained has an
average molar mass of about 4700 g/mol and an LCST of
about 39°C.
Example 7
(Version (e))
Synthesis of N-vinylcaprolactam LCST polymers
The polymerization of 348 g (2.5 mol) of N-vinylcapro-
lactam takes place in the same way as that of the N,N-
diethylacrylamide. The product obtained has an average
molar mass of about 5700 g/mol and an LCST of about
32°C.
Example 8
(Version (f))
Synthesis of methyl vinyl ether LCST polymers
The polymerization of 145 g (2.5 mol) of methyl vinyl
ether takes place in the same way as that of the N,N-
diethylacrylamide. The sticky product obtained has an
average molar mass of about 2500 g/mol and an LCST of
28 to 30°C.
Use Examples 1 to 6
A pearlescent pigment (Iriodin Afflair® 504;
manufacturer Merck KGaA, Darmstadt) is coated with the
LCST polymers of product versions (a) to (f). An
appropriate way of quickly investigating the
effectiveness of the polymeric coating of particles has
proven to be the use of platelet-shaped pearlescent
pigments. Since the unmodified form is deposited
relatively quickly in water, the improvement in
stability as a result of treatment with the LCST
polymer of the invention can be assessed within a short
time. The altered color effects as well can easily be
determined.,
Use Example 1
To treat Iriodin Afflair® 504 with the LCST polymer of
Example 1 (version (a)) a 0.5% strength polymer
solution is used. The pigment (10% by weight) is
dispersed in water at 800 rpm for 15 minutes. The
dispersion is subsequently cooled to a temperature of
0.5°C. Following the addition of the polymer solution
the pigment is coated with the polymer at 11°C for 30
minutes and the precipitated polymer is then cross-
linked for 3 h. The initiator system used is, per gram
of polymer, 0.8 g of sodium pyrosulfite, 0.4 g of
iron (II) sulfate and 0.8 g of potassium
peroxodisulfate. The polymer concentration, based on
pigment, was 5% by weight.
Use Example 2
In a similar way, Iriodin Afflair® is treated with the
LCST polymer of Example 4 (version (b)), the
temperature of the pigment dispersion being raised from
0.5°C to 11°C in order to coat the pigment. The polymer
layer is crosslinked using the polymerization initiator
of Use Example" 1 over a period of 3 h.
Use Example 3
In a similar way, Iriodin Afflair® 504 is treated with
the LCST polymer of Example 5 (version (c)), the
temperature of the pigment dispersion being raised from
0.5°C to 11°C in order to coat the pigment. The polymer
layer is crosslinked using the polymerization initiator
of Use Example 1 over a period of 3 h.
Use Example 4
In a similar way, Iriodin Afflair® 504 is treated with
the LCST polymer of Example 6 (version (d)), the
temperature of the pigment dispersion being raised from
10°C to 50°C in order to coat the pigment. The polymer
layer is crosslinked using the polymerization initiator
of Use Example 1 over a period of 3 h.
Use Example 5
In a similar way, Iriodin Afflair® 504 is treated with
the LCST polymer of Example 7 (version (e)), the
temperature of the pigment dispersion being raised from
10°C to 40°C in order to coat the pigment. The polymer
layer is crosslinked using the polymerization initiator
of Use Example 1 over a period of 3 h.
Use Example 6
In a similar way, Iriodin Afflair® 504 is treated with
the LCST polymer of Example 8 (version (f)), the
temperature of the pigment dispersion being raised from
10°C to 48°C in order to coat the pigment. The polymer
layer is crosslinked using the polymerization initiator
of Use Example 1 over a period of 3 h.
Use Example 7 (comparative)
In a similar way, Iriodin Afflair® 504 is treated with
the LCST polymer of the comparative example, the
temperature of the pigment dispersion being raised from
about 0°C to 5°C in order to coat the pigment. The
polymer layer is crosslinked using the polymerization
initiator of Use Example 1 over a period of 3 h.
The stabilizing effect of the treatment of the pigment
with the LCST polymer was assessed according to the
sedimentation behavior, by monitoring the settling
behavior of the 0.5% by weight pigment dispersion in
water. The results of these investigations are depicted
in Figures 1 and 2. Figures 1 and 2 show that both the
untreated pigment and the pigment treated with the
comparison polymer had settled to a high extent after
60 minutes, whereas the pigment treated with the LCST
polymers of the invention showed only slight settling.
The treated pigments were incorporated into a 2-
component hydroacrylic-melamine varnish at a
concentration of 10% by weight, based on the solids
content, by dispersion (peripheral speed 4 m/s, 15°C,
10 min) and investigated for their color properties
using an MA 68 Multi-Angle Spectrophotometer
colorimeter from X-Rite. The results of these
investigations are summarized in Table I.

The figures given in Table I were based on the
untreated pigment as reference. The state of dispersion
and the orientation of the platelet-shaped effect
pigments play a distinct role at low viewing angles. It
is clearly apparent that the LCST treatment has a
positive outcome for the color properties (lightness,
hue) of the effect pigment. This can be attributed to
the better state of dispersion and the flatter
orientation of the pigment particles.
The figures reported for AL, Aa and Ab in the inventive
examples in Table 1 can be attributed to the
orientation of the pigment particles. The pigment
treated with the polymer from the comparative example,
in contrast, showed lower orientation figures, which
are comparable with the figures for the untreated
pigment.
Use Example 8
A semiconductor wafer with a silicon dioxide surface
measuring 1 * 1 cm is immersed in 3 ml of distilled
water. The system is cooled to 2°C and 0.2 ml of a 10%
strength by weight LCST polymer solution of Example 1
is added. After two hours at 2°C the system is heated
to 23°C over the course of an hour. Thereafter it is
cooled to 2°C again, though only for a period of 10
minutes, and within an hour is heated to 23°C. This
cycle of cooling and heating is carried out a total of
three times. After the final cycle the wafer remains at
23 °C in the liquid coating medium for 24 hours and
thereafter is rinsed off with distilled water. The
polymer layer is subsequently crosslinked under thermal
induction; for this purpose the wafer is heated in a
drying oven at temperatures of 70 - 100°C for 5 hours.
Another possibility for crosslinking the polymer layer
is to irradiate the coated wafer with intense visible
light for 5 hours.
In a similar way the silicon wafer is treated with the
LCST polymer of Examples 4 and 5, the temperature range
of the polymer solution in the coating operation
extending from 2°C to 23°C. The crosslinking operation
takes place in the same way as for the polymer of
Example 1.
In a similar way the silicon wafer is treated with the
LCST polymers of Examples 6 to 8, the temperature range
of the polymer solution in the coating operation
extending from 10°C to 50°C, 10°C to 40°C and 10°C to
48°C, respectively. The crosslinking operation takes
place in the same way as for the polymer of Example 1.
The semiconductor wafer coated by the process described
above with the LCST polymer now possesses a more
strongly hydrophobic surface than a wafer without the
coating. This can be documented experimentally by
means of water droplets applied to the surface. The
coated and therefore more hydrophobic surface is wetted
less effectively by water than the unmodified surface.
The water droplet beads off from the coated wafer; on
the unmodified surface the droplet spreads out.
WE CLAIM:
1. An LCST polymer of the general formula

in which R1 (identical or different at each occurrence) is hydrogen or a methyl group, X1 and X2 =
-O—, —S— or —NH— and X1 additionally is a single bond if the first atom R2 is one of the
radicals indicated below:
a) a copolymer radical (Cop) containing at least two structural units —(—O—C2H4)n—
(ethylene oxide = EO) and -(—O—C3H6—)n— (propylene oxide = PO) or —(—O—C4H8)n—
(butylenes oxide = Bu) and —(—O—CH2—)n— (methylene oxide = MeO) in a molar ratio of 5
to 95 : 95 to 5, in which n (identical or different for each structural unit) is approximately 1 to
1000;

in which R is an alkyl group, r = (identical or different at each occurrence) 1 to 1000 and s
= 1 to 500);

in which o = 10 to 4000 and R3 (identical or different at each occurrence) is hydrogen or
alkyl groups having 1 to 5 carbon atoms;

in which p= 5 to 2000; or

2. The LCST polymer as claimed in claim 1, wherein the -(C3H6)— radical in (a) and (c) is an
isopropylene radical and the radical —(C4H8)— in (a) is an isobutylene radical.
3. The LCST polymer as claimed in claim 1, wherein the structural units -(EO)- and -(PO)- on the
one hand and the structural units -(BuO)- and -(MeO)- on the other hand are present in (a) in blocks
withn= 1 to 1000.
4. The LCST polymer as claimed in claim 3, wherein the blocks with the structural units -(PO)-
and -(BuO)- are disposed between the blocks with the structural units -(EO)- and -(MeO)-,
respectively.
5. A process for preparing an LCST polymer as claimed in any one of claims 1 to 4 (versions (a) to
(c)), wherein a compound of the general formula HO-[R2]—OH, in which R2 is as defined in claim 1, is
reacted with a compound of the formula

in which R1 is as defined in claim 1 and X is OH, halogen, preferably chlorine, an acid group, an
acrylic group or a lower alkoxy group, in a molar ratio of 1 : 1 to 1 : 4, especially 1:2.
6. A process for preparing an LCST polymer as claimed in claim 1 (version c), wherein
p-toluenesulfonyl chloride is reacted with a polyethylene oxide methyl ester of the formula H—[EO]r—
OCH3, in which r is as defined in claim 1 (c), to give a polyethylene oxide tosylate, this tosylate is
reacted with (NH2)-C3H6-[—PO—]s—NH2, in which s is as defined in claim 1 (c), to give H—[EO}—
NH—(PO)—NH—(EO) — OH, and this is reacted with (a)

in which R1 is as defined in claim 1 and X is as defined in claim 5, or (b) with the anhydride of
the corresponding acid.
7. A process for coating particles and nonparticulate substrate surfaces wherein particles or
nonparticulate substrate surfaces are provided and said particles or nonparticulate substrate surfaces are
coated with an LCST polymer as claimed in any one of claims 1 to 4 or prepared according to claim 5
or 6.
8. The process as claimed in claim 7, wherein the LCST polymer is contacted in a liquid below the
LCST temperature such as herein described with the particles or the nonparticulate substrate surfaces,
the temperature is raised to above the LCST temperature, and the polymers are polymerised via the
double bonds at this temperature or a higher temperature on the surface of the particles or on the
nonparticulate substrate surfaces.
9. Particles or nonparticulate substrate surfaces coated with a polymerised LCST polymer as
claimed in any one of claims 1 to 4.
Disclosed polymers of the general formula (I), wherein R1 (identical or differently)
represents hydrogen or a methyl group, X1 and X2 = -O-, -S- or -NH-, X1 additionally
representing a single bond if the first atom in R2 is not a C atom, and R2 represents one of the
following radicals : a) a copolymer radical (Cop) containing at least two structural units -(-O-
C2H4)n- (ethylene oxide - EO) and -(-O-C3H6-)n- (propylene oxide = PO) or -(-O-C4H8)n-
(butylene oxide = BuO) and -(-O-CH2-)n- (methylene oxide = MeO) at a molar ratio of 5 to 95 :

95 to 5, n representing approximately 1 to 1000 (identically or differently for each structural
unit); b) formula (II), wherein Cop represents a copolymer radical as defined in (a), and x =
1 to 5 and y = 1 to 20; c) formula (HI), wherein R represents an alkyl group, r = (identically
or differently) 1 to 1000 and s = 1 to 500; d) formula (IV) wherein o = 10 to 4000 and R3
(identically or differently) represents hydrogen or alkyl groups comprising 1 to 5 carbon
atoms; e) formula (V), wherein p = 5 to 2000; or formula (VI), wherein f) formula (VI),
wherein q = 10 to 4000. Also disclosed are methods for the production thereof and the use
thereof for coating particles and non-particulate substrate surfaces.

Documents:

1079-kolnp-2005-granted-abstract.pdf

1079-kolnp-2005-granted-claims.pdf

1079-kolnp-2005-granted-correspondence.pdf

1079-kolnp-2005-granted-description (complete).pdf

1079-kolnp-2005-granted-examination report.pdf

1079-kolnp-2005-granted-form 1.pdf

1079-kolnp-2005-granted-form 18.pdf

1079-kolnp-2005-granted-form 3.pdf

1079-kolnp-2005-granted-form 5.pdf

1079-kolnp-2005-granted-gpa.pdf

1079-kolnp-2005-granted-letter patent.pdf

1079-kolnp-2005-granted-reply to examination report.pdf

1079-kolnp-2005-granted-specification.pdf

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Patent Number

214257

Indian Patent Application Number

1079/KOLNP/2005

PG Journal Number

06/2008

Publication Date

08-Feb-2008

Grant Date

07-Feb-2008

Date of Filing

06-Jun-2005

Name of Patentee

SUD-CHEMIE AG

Applicant Address

LENBACHPLATZ 6, D-80333 MUNCHEN

Inventors:

#	Inventor's Name	Inventor's Address
1	KRAMER INGE	WETTERSTEINRING 32, D-85354, FREISING
2	SCHAUER THADEUS	WALDENSER STRASSE 56, D-75382, ALTHENGSSTETT
3	SCHROD MATTHIAS	ODENWALDRING 35, D-64859, EPPERTSHAUSEN
4	ENTENMANN MARK	HINTERE STRASSE 57, D-70734, FELLBACH

PCT International Classification Number

C09G 3/10

PCT International Application Number

PCT/EP2003/013098

PCT International Filing date

2003-11-21

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	102 54 430.1	2002-11-21	Germany