MXPA96006466A - Preparation of polymers for polymerization in emulsion - Google Patents

Abstract

Polymers of hydrophobic monomers (a) are prepared by emulsion polymerization, in the presence of at least one compound that is capable of forming a supramolecular structure

Description

PREPARATION OF POLYMERS BY POLYMERIZATION IN EHUS? OW The present invention relates to a process for preparing polymers by hydrophobic and hydrophobic monomer emulsion polymerization. ai s > > Aesua, monomer s hydrosolubin. Polymerization by radicals livery monomers e > * aqueous solutions < i of particular incer.-s industrie I. 'iri, oiiib &rcjc, an prerequisite for an olimerization < nn ao? nciór or the monomers. © s that Jos íon ik. F? Lam and 4n are dissolved in the solvent Jszadt mt «ß¿« «case«, if then for example, or TB capable of poly-neriaar monomers «or pola e by p & * l« - «-; ".6ii in water." The polymers of monomeric acid or alkaline polymers can be acrylic or acidic, and can be used as a catalyst. of poly ßriaffición in notation in aguíi a cope limer nc ón * 5 ') t o') l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l similarly, the water-soluble monomers are poor by the polymerization and emulsion method, but the method fails when they are incorporated into the method. -, given relatively large d% < or H-insolubles in water in ** 1 copolymer, because «the onomers have to migrate from the monomer droplet, through the aqueous phase, to the latex polymerizing particles. Bulk olimerization of water-soluble monomers and insoluble in water, it is necessary that the different monomers are compatible with each other, if it is desired to obtain uniform polymers. However, this is not assured in the case of comonomers having a very different polarity. In the case of other polymerization techniques, such as precipitation polymerization, the incompatibility of the water-insoluble monomers with the aqueous medium is also often a decisive disadvantage. From the prior art, it is known that cyclodextrins can serve as organic host molecules and are capable of accommodating one or two host molecules to form supramolocular structures, see for example W. Saenger, Angew. Chem. Int. Ed. Engl. 1980, 19, 344. G. Wßnz. Angew. Chem. Int. Ed. Engl. 1994. 33. 803-822 and F. Vogtle: Supremolßkulare Chemie, B.G. Teubner, Stuttgart. 1989. Thus, for example, crystalline ethylene and cyclodextrin complexes are known. In the J. Macromol. Sci. Chem., A13, 87-109 (1979) describes the inclusion of polymer compounds that are prepared by free radical polymerization of monomers in a 0-cyclodextrin matrix. in dimethylformamide solution. The monomers mentioned are vinylidene chloride, methyl acrylate, styrene and methacrylonitrile. DE-A-4,009,621 discloses fast hardening adhesive compositions based on a-cyanoacrylates containing cyclodextrin derivatives which are at least partially soluble in the a-cyanoacrylates. European Patent EP-460896 describes the action of cyclodextrins on the viscosity of hydrophobic thickeners in aqueous systems. An object of the present invention is to provide a process for preparing polymers of hydrophobic monomers, whose solubility in water is not sufficient for the monomer to be able to diffuse through the aqueous phase and, if desired, water-soluble monomers. by polymerizing the monomers in an aqueous solvent. It has been found that this objective is achieved by a process for preparing polymers by emulsion polymerization of hydrophobic monomers (a) and, if desired, water-soluble monomers, wherein the polymerization is carried out in the presence of at least one compound (b) ) that is capable of forming a supramolecular structure.

The suitable compounds (b) are capable of entering into association with the monomer (a), in such a way that the water diffusibility of the monomer (a) is improved. Compounds (b) include host-host complexes such as clathrates. cryptandos, pruning. sphere and spheres (see F. Vogtle, Supramolekulare Chemie, B.G. Teubner, Stuttgart 1989) and, in particular, compounds having a cyclodextrin structure. Apart from the a-, 0-,? - and or * -cyclodextrins described in the aforementioned references in the scientific literature, compounds having a cyclodextrin structure also include chemically modified lodextrins. The cyclodextrins themselves are obtained, for example, by enzymatic degradation of starch and consist, for example, of 6 to 9 D-glucose units which are linked to one another through an α-1,4-glucosidic bond. The a-cyclodextrin consists of 6 molecules of glucose, the 0-cyclodextrin consists of 7 molecules of glucose. For the purposes of the present invention, the chemically modified cydextrins are the products of the reaction of cyclodextrins with reactive compounds; for example, products of the reaction of cyclodextrins with alkylene oxides such as ethylene oxide, propylene oxide. butylene oxide or styrene oxide. products of the reaction of cyclodextrins with alkylating agents for example halides and alkyl of 1 to 22 carbon atoms, such as methyl chloride, ethyl chloride, butyl chloride, ethyl bromide, butyl bromide, benzyl chloride, lauryl, styryl chloride or beheni chloride and dimethyl sulfate. It is also possible to make additional modifications to the c-clodextrins by a reaction with chloroacetic acid. Cyclodextrin derivatives containing cyclodextrin structures can also be obtained by enzymatic linkage with maltose oligomers. The reaction products of the aforementioned type are alkylated (motilated), hydroxyalkylated and sulfonatoalkylated cyclodextrins, such as dimethyl-0-cyclodextrin, hydroxypropyl-cyclodextrin and sulfonatepropylhydroxypropyl-0-cyclodisstrotine. Among the compounds of group (a), preference is given to using a-cyclodextrin. 0-cyclodextrin. ? -cyclodextrin and / or motilated cyclodextrins, for example 2,6-dimethyl-0-cyclodextrin or its isomers and homologs. The compounds (b) can be used as complexes with the hydrophobic monomer (a), for example, the molar ratio d? (to) . (b) egtá ßn? l range ß 1: 1 to 1: 5 # in particular from 1: 1 to 1: 3. However, it is preferred to use the compounds (b) in substoichiometric amounts. for example the molar ratio (a): (b) is in the range of 5000: 1 to 2: 1 preferably from 1000: 1 to 2: 1. in particular from 500: 1 to 10: 1 and from 100: 1 to 10: 1 and particularly preferred from 80: 1 to 20: 1. Examples of the compounds (a) are alkyl esters of 2 to 40 carbon atoms (in particular 2 to 30 carbon atoms) of acrylic acid or alkyl esters of 1 to 40 carbon atoms (in particular 1 to 30) carbon atoms) of ethacrylic acid, for example methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-propyl acrylate. methacrylate of i-propyl, isopropyl acrylate, isopropyl methacrylate, n-butyl acrylate, n-butyl methacrylate, isobutyl acrylate, isobutyl methacrylate. trt-butyl acrylate, pentyl acrylate. pentyl methacrylate, n-hexyl acrylate. n-hexyl methacrylate. n-heptyl acrylate. n-heptyl methacrylate, n-octyl acrylate. n-octyl methacrylate. acrylate of 2-eti lhßxi lo. 2-ethyl-lysylmethacrylate, d-acrylate acrylate. decyl methacrylate. lauryl acrylate. lauryl methacrylate. acrylate of palmitilo. palmityl methacrylate, stearyl acrylate. stearyl methacrylate. (meth) hydrenol acrylate, behenyl (meth) acrylate, polyisobutene (meth) acrylate. phenoxyethyl acrylate. phenoxyethyl methacrylate. phenyl acrylate and fonro methacrylate. Other monomers of group (a) are the α-olefins having from 2 to 30 carbon atoms and also polyisobutyl groups having from 3 to 50, preferably from to 35 isobutene units. Examples of α-olefins are ethylene, propylene. n-butene. Isobutene, 1-pentanten. cyclopisostene 1-hexene. cyclohexene, 1-octone. diisobutylene (2,4,4-trimethyl-1-pßntβ, possibly mixed with 2,4,4-trimotyl-2-pßntßno), 1-dßcßno. 1-dodecene, 1-octadecene. olefins of 12 to 14 carbon atoms, olefins of 20 to 24 carbon atoms, vinylaromatic compounds such as styrene, α-mßti-styrene. vinylpyridines such as 4-vinylpyridine. or ipropylenes having a terminal vinyl or vinylidene group and having from 3 to 100 propylene units, polyisobutene having from 3 to 35 isobutene units and having a terminal vinyl or vinylidene group, oligohexene or oligooctadecene. Other suitable monomers (a) are butadiene and isoprene. When these monomors are used, the polymerization is carried out under pressure. An additional class of monomers of group (a) comprises N-alkyl-substituted acrylamides and methacrylamides. for example N-tert-buti lacri lick. N-hexy lmetacri lamide, N-octilacri lamide. N-noni lmetacri lick. N-dodeci Imetacri licked. N-H -xadecylmethacrylamide. N-methacrylamidocaproic acid, N-methacrylamidoundecanoic acid, N, N-dibutyl lacrylamide, N-hydroxythi lacrylamide and N-hydroxystilmetacri lamide. Other monomers of group (a) are vinylalkyl ethers which have from 1 to 40 carbon atoms in the alkyl radical, for example methylvinyl ether, ethylvinyl ether, n-propylvinyl ether, isopropylvinyl ether, n-butylvinyl ether. isobuty lvinyl ether. 2-ethylhexylvinyl ether, decylvinyl ether, dodecylvinyl ether, stearyl vinyl ether. 2- (diethylamino) otilvinyl ether. 2- (di-n-butylamino) ethylvinyl ether. methyldiglycolvinyl ether and also the corresponding allyl ethers. such as allyl methyl ether, allyl ethyl ether, allyl n-propyl ether, i1 isobutyl 1 ether and allyl-2-ethyl hexyl ether. Additional compounds suitable as monomers of group (a) are water-insoluble acids or esters having a solubility of at most 20 g / l in water of maleic acid and fumaric acid which are derivatives of monohydric alcohols having from 1 to 22 atoms of carbon, for example mono-n-butyl maleate, dibutyl maleate, monodecyl maleate, didodecyl maleate, monooctadecyl maleate and dioctadecyl maleate. Also suitable are vinyl esters of saturated carboxylic acids of 3 to 40 carbon atoms, such as vinyl propionate. vinyl butyrate. vinyl valerate. Vinyl 2-ethylhexanoate. vinyl decanoate. vinyl palmitate, vinyl stearate and vinyl laurate. Other monomers of group (a) are metacri lonitri lo. vinyl chloride. vinylidene chloride, isoprene and butadiene. The monomers of group (a) mentioned above can be used alone or in mixtures of two or more to prepare the complexes or in the polymerization. Preferred monomers (a) are the alkyl esters of 2 to 30 carbon atoms of acrylic acid, alkyl esters of 1 to 30 carbon atoms of methacrylic acid, α-olefins of 2 to 30 carbon atoms, vinylalkyl ethers of 20 carbon atoms, vinyl esters of carboxylic acids of 2 to 20 carbon atoms, vinylaromatic compounds. in particular styrene. butadiene, ißoprene or mixtures thereof, in particular mixtures of at least one of said esters of acrylic and / or methacrylic acid, with at least one vinyl aromatic compound, preferably styrene. Particularly preferred monomers (a) are methyl methacrylate, ethyl acrylate, butyl acrylate, t-butyl acrylate. t-butyl methacrylate. 2-ethylhexyl acrylate. lauryl acrylate, ßstearyl acrylate.

Hydrenol acrylate, behenyl acrylate. (met) acrylate of polyisobutene. vinyl acetate. vinyl stearate. Isobutene, 1-hßxßno. diisobutene 1-dodecene 1-octadecene. polyisobutenes having 15 to 35 isobutylene units. styrene, methylvinyl ether, ethylvinyl ether, etherylvinyl ether or mixtures thereof. The hydrophobic monomers (a) can be polymerized by free radicals alone or mixed with one another. In addition, it is possible to copolymer the monomers (a) with water-soluble monomers. Suitable water-soluble monomers, which will hereafter be referred to as monomers of group (c), have a water solubility of greater than 20 g / 1. Examples of these are unsaturated monoethylenic carbon carboxylic acids of 3 to 5 carbon atoms, their amides and esters with aminoalcohols of the formula wherein R - an alkylene group of 2 to 5 carbon atoms 1 2 3 - carbon. R. R. R "H. CHg. C ^ R ^. The amides of these carboxylic acids which are derived from amines of the formula are also suitable and X is an anion.

The substituents in formula II and X are as defined for formula I. Examples of these compounds (c) are acrylic acid. methacrylic acid. crotonic acid, itaconic acid, maleic acid. fumaric acid, acrylonitrile. acri lick, methacrylamide. crotonamide, dimethylaminoethyl acrylate, diethylaminoethyl acrylate. dimethylaminoneopentyl acrylate and dimethylaminoethyl methacrylate, dimethylaminopropyl acrylate, dimethylaminoneopentyl acrylate and dimethyl laminoneopentyl methacrylate. The carboxylic acids mentioned can be used as free acids or in partially or completely neutralized form, for example with an alkali metal or ammonium salts. The basic esters or basic amides derived from the compounds of the formula II are used in the form of their salts with strong mineral acids, sulfonic acids or carboxylic acids. or in quaternary form.

The anion X in the compounds of the formula I is the corresponding anion of the mineral acids or carboxylic acids or their methosulfate, ethosulfate or halide of a quaternary agent. Further water-soluble monomers of group (c) are N-vinylpyrrole idone, N-vinylformamide, acrylamidopropanesulfonic acid, vinylphosphonic acid and / or salts with alkali metals or ammonium salts of vinylsulphonic acid. These acids, similarly, can be used either in a non-neutralized form or in a partially or 100% neutralized form in the polymerization. Other suitable water-soluble monomers of group (c) are dialkyl ammonium compounds such as dimethyldiallylamine chloride. diethyldiallylammonium chloride or diallylpiperidinium bromide. N-vinylimidazolium compounds such as quaternary salts or products of N-vinylimidazole and l-vinyl-2-methylimidazole. and N-vinylimidazolines such as N-vinylimidazoline. 1-vinyl-2-methylimidazoline. l-vinyl-2-ß-methylimidazoline or 1-vini1-2-n-propylimidazoline, which are used similarly in quaternary form or as a salt in the polymerization. Preferred monomers of group (c) are carboxylic acids having from 3 to 5 carbon atoms monoethylenically unsaturated. vinylsulfonic acid.

Acrylamidomethylpropanesulfonic acid. vinylphosphonic acid, N-vinylformamide. (meth) acrylates of dimethylaminoethyl. alkali metal, ammonium or quaternary ammonium salts of the specified monomers containing an acid or amino group. or mixtures of the monomers. Of particular importance is the use of acrylic acid or mixtures of acrylic acid and maleic acid or their salts with alkali metals in the preparation of hydrophobically modified water-soluble copolymers, with preference being given to the use of N-butyl acrylate. N-stearyl acrylate and / or styrene. as monomers of group (a). To prepare the crosslinked polymers which are used, for example, as thickeners for aqueous systems, the hydrophobic monomers of group (a) and. if desired, at least one monomer of group (c), are polymerized in the presence of compounds containing cyclodextrin structures and at least one class of crosslinking monomers. For this purpose the customary reticers are used, examples being divinylbenzene. Diallyl phthalate, allyl vinyl ether and / or diallyl fumarate. etc. The preparation of the crosslinked polymers. if desired, it can additionally be carried out in the presence of crosslinkers which are water-soluble. Examples of such monomers are acrylamidoglycolic acid, N-methylolacrylamide. N-moti lolmetacri lamide, 1,4-bisaminooxybutane, adipic dihydrazide, for example, in the presence of a ketone. N. N'-methylenebisacrylamide, polyethylene glycol diacrylate and polyethylene glycol dimethacrylates, each being derived from polyethylene glycols having a molecular weight of from 126 to 8500. triacrylate of trimethylolpropane. Trimethacrylate of trimethylolpropane, diacrylate of ethylene glycol, propylene glycol diacrylate. butanediol diacrylate. hexanediol diacrylate. hexanodiol dimethacrylate. diacrylates and dimethacrylates of block copolymers of ethylone oxide and propylene oxide, polyhydric alcohols such as glycerol or pentaerythritol diesterified or triesterified with acrylic acid or methacrylic acid. triallylamine. tetraalylethylenediamine trimethylolpropane dial i 1 ether, pentaerythritol triallyl ether and / N 'N'-divinyl bistilenur. The crosslinkers are preferably used in amounts of 0.01 to 40% by weight, in particular 0.5 to 5% by weight, based on the total amount of monomers used in the copolymerization. However, the crosslinkers can also be polymerized alone to obtain homopolymers. The polymerization of the water-insoluble monomers and, if desired, water-soluble monomers, is carried out by emulsion polymerization in an aqueous medium, preferably in water. The term "aqueous medium" herein also includes mixtures of water and organic liquids miscible with it. Examples of organic liquids miscible with water are polyols, in particular glycols such as ethylene glycol. propylene glycol. 1. 3-butylene glycol, diethylene glycol. tri-ethylene glycol, tetra-ethylene glycol and glycerol. copolymers of β-ethylene oxide block and propylene oxide. alcohols of 1 to 20 alkoxylated carbon atoms, acetic esters of glycols and polyglycols. alcohols such as methanol. ßtanol. isopropanol and butane1. acetone, tetrahydrofuran. dimethylformamide. N-methyl 1-pyrrolidone or mixtures thereof. If the polymerization is carried out in mixtures of water and water-soluble solvents, the proportion of water miscible solvents in the mixture is up to 75% by weight. The emulsion polymerization of the monomers is normally carried out to the exclusion of oxygen, for example at a temperature of 20 to 200 * C, preferably of 35 to 140 * C. The polymerization can be carried out batchwise or continuously; Preferably, at least a portion of the initiator and regulator monomers, if used, are uniformly introduced during the polymerization into the reaction vessel containing the aqueous solvent in which the compounds containing cyclodextrin structures are dissolved. However, in the case of relatively small batches, the monomers and the polymerization initiator can also be charged into the reactor from the beginning for polymerization. In this case it may be necessary to cool the reactor to provide a sufficiently rapid removal of the heat of polymerization. The polymerization is preferably carried out by a free radical mechanism. In this case, suitable polymerization initiators are those compounds which are normally used in free radical polymerizations and which produce free radicals under the polymerization conditions, for example. peroxides hydroperoxides, peroxodisulfates. β-carbonate, poroxyesters, hydrogen peroxide and azo compounds. Examples of initiators are hydrogen peroxide, dibenzoyl peroxide, dicyclohexyl peroxydicarbonate, di lauryl peroxide, methylethyl ketone peroxide. Acytylacetone peroxide, tert-butyl hydroperoxide. eumeno hydropyrroxide, tert-butyl perneodecanoate. tert-amyl perpivalate. tert-butyl perpivalate, tert-butyl perneohexanoate. tert-butyl per-2-ethylhexanoate »tert-butyl perbenzoate, lithium, sodium, potassium and ammonium poroxodisulfate. azobisisobutyronitrile. 2, 2'-azobis (2-amidinopropane), 2- (carbamoylazo) isobutyronitrile and 4,4 * -azobis (4-cyanovaloric acid) dihydrochloride. The initiators are normally used in amounts of up to 15% by weight, preferably from 0.02 to 10% by weight, based on the monomers to be polymerized. The primers can be used alone or mixed with one another. It is also possible to use the known redox catalysts, in which the reducing component is used in a molar deficiency. The known redox catalysts are. for example, transition metal salts such as iron (II) sulfate, cobalt (II) chloride. nickel sulfate (II). copper chloride (I), manganese acetate (II), vanadium acetate (III). Other suitable redox catalysts are ascorbic acid. reducing sulfur compounds such as sulfites, bisulfites, thiosulfites, dithionites and tetrathionates of alkali metals and reducing ammonium compounds or phosphorus compounds in which phosphorus has an oxidation state of 1 to 4. eg sodium hypophosphite, acid phosphorous and phosphites. To control the molecular weight of the polymers, the polymerization, if desired, can be carried out in the presence of regulators. Suitable regulators are, for example. aldehydes such as formaldehyde, acetaldehyde. proionaldehyde. N-butyraldehyde isobutyraldehyde. formic acid, ammonium formate. hydroxy 1 ammonium sulfate and hydroxy 1 ammonium phosphate. It is also possible to use regulators containing sulfur in organically bound form, for example organic compounds containing SH groups, for example thiomalic acid, thioglycolaacetic acid, mercaptoacetic acid. mercaptopropionic acid. mercaptoethanol. mercaptopropanol. mercaptobutanols. mercaptohexanol. dodeci lmercaptaño and tert-dodecilmercaptano. Other regulators that may be used are hydrazine salts such as hydrazinium sulfate. The amounts of the regulator, based on the monomers to be polymerized, are from 0 to 20% by weight, preferably from 0.5 to 15% by weight. The polymerization can be carried out in the presence of an emulsifier and / or protective colloid of those customary for these purposes. Suitable protective colloids are, for example, polyvinyl alcohols. cellulose derivatives or polyvinylpyrrolidones. The emulsifiers can be anionic, cationic or non-ionic in nature. Suitable emulsifiers are, for example, onoalkylphenols. ethoxylated dialkylphenols and trialkylphenols (EO content: 3-50, alkyl radical: C4 ~ Cg), ethoxylated fatty alcohols (E0 content: 3-50 alkyl radical: Cg-C36) and also alkali metal and ammonium sulphate salts of alkyl (radical alkylCG-C. _). of sulfuric monoesters of ethoxylated alkanols (content of E0: 4-30, alkyl radicals of cycloalkyl and ethoxylated alkylphenols (content of EO: 3-50, alkyl radical: C 4 _, - C "9) of alkylphosphonic acids ( alkyl radical: C12-C18) of lignisulonic acid and alkylarylsulfonic acids (alkyl radical: C8-Clß). Particularly suitable emulsifiers have been found to be the compounds of the general formula I wherein R 1 and R 2 are hydrogen or an alkyl group of 4 to 24 carbon atoms and they are not simultaneously hydrogen, and X and Y can be alkali metal ions and / or ammonium ions. In formula I, R 1 and R 2 are preferably straight or branched chain alkyl radicals having from 6 to 18 carbon atoms, wherein R 1 and R 2 are not simultaneously hydrogen. X and Y are preferably sodium, potassium or ammonium ions.

It has been found that the polymerization can also be carried out without an emulsifier or protective colloid. particularly when amphiphilic cyclodextrins such as dimethylcyclodextrins are used. The polymers can be in the form of inclusion compounds or can be obtained therefrom. The formation of inclusion compounds from the polymers and the compounds of component (a) is reversible. After the polymerization, the polymers are normally present in the latex particles separated from the compounds (a). If the polymers are present in the form of inclusion components after the preparation, they can be released from the inclusion compounds and can be isolated, for example, by addition to the reaction mixture, of wetting agents such as ethoxylated alcohols. long chain. If desired, the dispersion obtained can be diluted with an organic liquid miscible with water. The amount of organic liquid in the dispersion can be up to 75% by weight, based on the total weight of the liquid phase. Suitable organic liquids have already been mentioned above, with the specified polyols being preferred, particularly if the dispersion is used for petroleum treatment. Polymers hydrophobically modified by the process of the present invention, for example, can be used as thickeners, for example in cosmetic creams or lotions, as components in surface coating formulations, as surveyors in papermaking, as coating compositions , as, raw material for adhesives, as additives for laundry detergents or as dispersants for pigments. In addition, such polymers can be used as tanning agents. brighteners agents. liquorizing agents or hydrophobicizing agents for the production of leather. The hydrophobically modified polymers also serve as polymeric emulsifiers which stabilize a fine dispersion of a non-polar material in a polar phase. Crosslinked polyacrylates, which are obtained, for example, by copolymerizing acrylic acid with hydrophobic monomersß in the presence of a cyclodextrin and a water-insoluble crosslinker such as divinylbencon. They are used as superabsorbents or thickeners for aqueous systems. In addition, the dispersion of the present invention can be used for the treatment of petroleum, particularly to decrease the pour point, for example crude oil, hot oil or diesel. The following examples illustrate the present invention without limiting it. General procedure for the copolymerization at atmospheric pressure of the monomers specified in the tables presented below: The cyclodisstrote derivative was placed in a flask together with 360 g of water. Nitrogen was bubbled into the flask and heated to 80 ° C. To this mixture was added 0.6 g of sodium persulfate in the form of a 2% strength aqueous solution. 600 g of the desired monomer mixture were prepared and mixed with 3 g of the emulsifier (dodecyl sodium sodium sulfonate) in the form of a 15% strength aqueous solution. 3 g of this mixture was added to the flask. The polymerization was carried out for 15 min at 80 ° C. Subsequently, the remaining amount of the monomer and 2.4 g of sodium persulfate were introduced over a period of 4 hours and then 1.9 g of Rongalit (hydroxymethanesulfonic acid) were added and 2.4 g of t-butyl hydroperoxide to the reaction mixture The stirring was continued for an additional period of 90 minutes, the reaction mixture was cooled to room temperature and filtered through a filter of 125 μm to remove any clot The solids content of the dispersion was 43.4% The composition of the monomer is given in the tables presented below A film was produced from the polymer dispersion by casting on an aluminum sheet and drying 110'C, and this film was examined by means of DSC, glass transition temperatures and measured melting points are given in the tables presented below, in the Which were the following abbreviations used: n-BA n-butyl acrylate S? stearyl acrylate S styrene Acrylic acid CD1 0-cyclodßxtrin CD2 0-cyclodextrin containing 1.8 methyl units per glucose ring T glass transition temperature Mp melting point Coag. clot C comparative experiment. The amount of the individual monomers is based on the total amount of monomers. In a similar way, the amount of cyclodextrins is based on the total amount of monomers.

Examples 1 to 3 and comparative examples 1 to 3 (VI to V3) Table 1 From the comparative examples, it can be seen that even when stearyl acrylate is used, the glass transition temperature does not decrease and a melting peak at 48 ° C can be observed in the DSC (Differential Scanning Calorimetry). The production of clots rises when the proportion of stearyl acrylate in the monomer mixture increases, and it can be concluded from the above that the styryl acrylate was not incorporated into the copolymer. The polysecreteil formed was precipitated as a clot.This proportion of clot increases after a number of days.

In contrast, it can be seen in Examples 1 to 3 that the vitreous transition temperature of the polymer decreases as the proportion of styryl acrylate increases. It was not possible to observe a melting peak or the formation of clots. This means that the total amount of stearyl acrylate used had been incorporated into the copolymer. Examples 4 to 6 and Comparative Examples 4 and 5 Table 2 Comparative examples 4 and 5 show that a melting peak occurs at 44 * C when stearyl acrylate is used as the comonomer. This means that there has been an additional formation of almost pure polyestearyl acrylate which is not present in stable dispersed form, but is partially precipitated immediately (2%) and precipitates almost quantitatively after storing for a number of hours. In turn, examples 4 to 6 show that although copolymer of n-butyl acrylate and stearyl acrylate was not formed. the total amount of stearyl acrylate and n-butyl acrylate had been homopolyzed and the two polymers were quantitatively present in a finely divided dispersed form. This is a particularly attractive industrial method for preparing dispersions comprising mixtures of two homo-polymers having complementary properties, without the respective dispersions having to be synthesized separately and subsequently mixed. Examples 7 to 11 and Comparative Example 6 Table 3 Examples 7 to 11 show that the incorporation of increasing amounts of stearyl acrylate causes a continuous decrease in the vitreous transition temperature, for example, the entire styryl acrylate was incorporated into the polymer. Example 12: Copolymer containing behenyl acrylate 30.0 of dimethyl-0-cyclodßxtrine having 1.8 methyl units per glucose ring was placed in a flask together with 400 g of water. The flask was bubbled with nitrogen and heated to 80 * C. To this mixture was added 0.6 g of sodium persulfate in the form of a 2% strength aqueous solution. Separately, a mixture of 474.0 g of styrene was emulsified. 120.0 of behenyl acrylate and 6.0 g of acrylic acid in 160 g of water, using 20.0 g of emulsifying solution (aqueous solution of dodecyl lbensensulfonate of sodium at 15% strength). 3.9 g of the emulsion was added to the initial charge and the partial polymerization was allowed to proceed for 15 min at 18 ° C. Then, the rest of the emulsion was allowed to run over a period of 225 minutes and, parallel to this, 2.4 g of sodium persulfate was allowed to run in the form of a 2% strength aqueous solution over a period of 240 minutes. . The polymerization was allowed to proceed for an additional 10 minutes at TO'C and 1.9 g of hydroxymethanesulfonic acid and 2.4 g of t-butyl hydroperoxide were added. Stirring was continued for an additional 90 minutes, then the reaction mixture was cooled to room temperature and filtered through a 125 μm filter. The solids content of the dispersion obtained was 45.7%. no clot formation was observed. The glass transition temperature (determined in the manner described above) was 54 * C. EXAMPLE 13 α-Dodecene-containing copolymer A copolymer of 534.0 g of styrene, 60.0 g of α-dodecene and 6.0 g of acrylic acid was prepared using the method described in Example 12. The amount of clot was <1 g and the vitreous transition temperature of the copolymer obtained was 63 * C. Example 14 and Comparative Example 7 General procedure for pressure copolymerization using butadiene. An initial charge of 4000 g of water and 150 g of cyclodextrin was heated to 90 * C. 3 g of sodium persulfate were added and, when appropriate, some planting material. 3000 g of the monomer mixture indicated in Table 4 below was emulsified in 4000 g of water using 30 g of Dowfax "(sulfonated alkyl diphenyloxide) provided by Dow Chemical Company) and 30 g of sodium lauryl sulfate. Sodium, 30 g of p-dodecyl mercaptan was added as a regulator, this mixture, together with 2700 g of a strength 10% sodium persulfate solution, was left in the initial charge for a period of 4.5 hours, so that the pressure did not exceed 6 bars After an additional polymerization time of 3 hours, the mixture was chemically treated for 4 hours using 4 g of t-butyl hydropyrroxide and 3 g of hydroxymethanesulphonic acid The solids content of the dispersion obtained it was 17.7% The production and characterization of the films was carried out in the manner described above The results obtained are shown in Table 4 below.

The DSC analysis shows a significant reduction of the vitreous transition temperature in the Example 14, compared to Comparative Example 7.

A melting peak could not be observed. This means that the stearyl acrylate had been copolymerized.

Claims (12)

1. CLAIMS 1. A process for preparing polymers by emulsion polymerization of hydrophobic monomers (a) and. if desired, water-soluble monomer. characterized in that the polymerization is carried out in the presence of at least one compound (b), which is capable of forming a supramolecular structure.
2. 2. A process according to claim 1, characterized in that a compound having a cyclodextrin structure is used as compound (b).
3. 3. A process according to any of claims 1 or 2, characterized in that the molar ratio of (a): (b) is in the range of 5000: 1 to 1: 5.
4. A process according to any of claims 2 or 3, characterized in that the compound having a cyclodextrin structure is an a-, 0-, y- or β-cyclodextrin and / or a chemically modified cyclodextrin, in particular cyclodextrin motilated.
5. 5. A process according to any of the preceding claims, characterized in that the aqueous medium comprises not only water, but also an organic liquid miscible with water.
6. 6. A process according to any of the preceding claims, characterized in that the monomers (a) used are alkyl esters of 2 to 30 carbon atoms of acrylic acid, alkyl esters of 1 to 30 carbon atoms of methacrylic acid, a -olefins of 2 to 3 carbon atoms, alky vinyl ethers of 1 to 20 carbon atoms, vinylesters of alkanoic acids of 2 to 20 carbon atoms, acri lamides and methacrylamides N-substituted with alkyl radicals of 1 to 30 carbon atoms , styrene, butadiene, isoprene or mixtures thereof.
7. 7. A process according to claim 6, characterized in that the monomers (a) used are at least one alkyl ester of 2 to 30 carbon atoms of acrylic acid and / or at least one alkyl ester of 1 to 30 carbon atoms. of methacrylic acid, together with ßstirene.
8. 8. A process according to any of claims 6 or 7. characterized in that the monomers (a) used are methyl methacrylate, otyl acrylate, butyl acrylate, t-butyl acrylate. t-butyl methacrylate. 2-ßti lhßxilo acrylate. lauryl acrylate. stearyl acrylate, hydrenol acrylate. behenyl acrylate. polyisobutene (meth) acrylate. vinyl acetate. vinyl ester. isobutene, 1-hexene, diisobutone, 1-dodecone, 1-octadecene, poly isobutenes having from 3 to 5 isobutene units, styrene. methylvinyl ether, ethylvinyl ether, stearylvinyl ether or mixtures thereof.
9. 9. A process according to any of the preceding claims, characterized in that the monomers (a) also include crosslinking monomers.
10. 10. A process according to any of the preceding claims, characterized in that the hydro-soluble monomers used are carboxylic acids of 3 to 5 carbon atoms monoethylenically unsaturated, acrylonitrile, vinylsulfonic acid. acrylamido-methylpropanesulfonic acid, vinylphosphonic acid. N-vinylformamide, dialkylaminoethyl (meth) acrylates, alkali metal, ammonium or quaternary ammonium salts of said monomers. containing an acid group or an amino group, or mixtures of the monomers with one another.
11. 11. An aqueous polymer dispersion obtained by a process according to any of the preceding claims.
12. 12. An aqueous polymer dispersion according to claim 11, characterized in that it includes an organic liquid miscible with water, in particular a polyol.