EP0848722A1

EP0848722A1 - Method for the production of polymerisates in an aqueous medium and the use thereof

Info

Publication number: EP0848722A1
Application number: EP96931021A
Authority: EP
Inventors: Gunnar Schornick; Axel Kistenmacher; Helmut Ritter; Julia Jeromin; Olaf Noll; Markus Born
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 1995-09-08
Filing date: 1996-09-04
Publication date: 1998-06-24
Also published as: WO1997009354A1; DE19533269A1

Abstract

The invention relates to a method for the production of polymerisates from monomers insoluble in water and monomers optionally soluble in water by radical polymerisation of the monomers in water as the diluting agent, wherein the monomers insoluble in water are used in the form of complexes consisting of (a) cyclodextrins and/or compounds containing cyclodextrin structures, and (b) monomers which are insoluble in water or ethylenically unsaturated and soluble in water up to a maximum of 20 g/l at 20 °C, in the mol ratio (a):(b) of from 1:2 to 10:1, or the monomers are polymerised in the presence of up to 5 mol, in relation to 1 mol of the monomers (b), of cyclodextrins and/or compounds containing cyclodextrin structures. It also relates to the use of the polymerisates as sizing agents for the production of paper, as coating agents, as thickening agents for aqueous systems, as detergent additives and as thickening agents in cosmetic creams or lotions.

Description

Process for the preparation of polymers in an aqueous medium and their use

description

The invention relates to a process for the production of polymers from water-insoluble monomers and optionally water-soluble monomers by radical polymerization of the monomers in a diluent and the use of the polymers as sizing agents for papermaking, as coating agents, as thickeners for aqueous systems, as a detergent additive and as a thickener in cosmetic creams or lotions.

The radical polymerization of monomers in aqueous solutions is of particular technical interest. However, a prerequisite for solution polymerization of the monomers is that the monomers also dissolve in the solvent used in each case. For example, it is not possible to polymerize non-polar monomers in the manner of solution polymerization in water. Water-soluble monomers, such as acrylic acid or maleic acid, are produced industrially by the process of solution polymerization in water. The copolymerization of, for example, acrylic acid with water-insoluble monomers is therefore not possible in an aqueous medium.

According to the water-in-oil emulsion polymerization process, water-soluble monomers are also polymerized by free radicals. However, this method also fails if larger amounts of water-insoluble comonomers are to be incorporated into the copolymer because the water-soluble monomers polymerize in the aqueous phase and the water-insoluble monomers in the oil phase, so that virtually no copolymerization occurs.

Even in the bulk polymerization of water-soluble and water-insoluble monomers, it is necessary for the different monomers to be compatible with one another in order to obtain uniform polymers. However, this is not guaranteed for comonomers with very different polarities. In other polymerization techniques, too, such as precipitation polymerization, the incompatibility of water-insoluble monomers with the aqueous media is often a decisive disadvantage.

It is also known from the prior art that cyclodextrins can serve as organic host molecules and are able to form one or two guest molecules with the formation of supramolecular ones To include structures, cf. W. Saenger, Angew. Chem. Int. Ed. Engl. 1980, 19_, 344 and G. Wenz. Appl. Chem. Int. Ed. Engl. 1994, 3_3_, 803-822. For example, crystalline complexes of ethylene and cyclodextrin are known.

From J. Macromol. -Chem. , A13, 87-109 (1979), inclusion compounds of polymers are known which are produced by radical polymerisation of monomers in a β-cyclodextrin matrix in dimethylformamide solution. Vinylidene chloride, methyl acrylate, styrene and methacrylonitrile are mentioned as monomers.

DE-A-4 009 621 discloses fast-setting adhesive compositions based on α-cyanoacrylates which contain at least partially soluble derivatives of cyclodextrins in α-cyanoacrylates.

The present invention has for its object to provide a process for the preparation of polymers from water-insoluble monomers and, if appropriate, water-soluble monomers by radical polymerization of the monomers in a diluent.

The object is achieved according to the invention if the polymerization is carried out in water as a diluent and the water-insoluble monomers in the form of complexes

(a) Cyclodextrins and / or compounds containing cyclodextrin structures and

(b) water-insoluble or at most up to 20 g / l of water-soluble ethylenically unsaturated monomers at 20 ° C.

in a molar ratio (a): (b) of 1: 2 to 10: 1 or the monomers in the presence of up to 5 mol, based on 1 mol of the monomers (b), of cyclodextrins and / or cyclodextrin structures ¬ holding compounds polymerized.

Suitable cyclodextrins are the α-, β-, γ- and δ-cyclodextrins described in the references mentioned above. They are obtained, for example, by enzymatic breakdown of starch and consist of 6 to 9 D-glucose units which are linked to one another via an α-1,4-glycosidic bond. α-Cyclodextrin consists of 6 glucose molecules. Compounds containing cyclodextrin structures are to be understood as meaning reaction products of cyclodextrins with reactive compounds, for example reaction products of cyclodextrins with alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide or styrene oxide, reaction products tion products of cyclodextrins with alkylating agents, for example Ci * to C ₂₂ alkyl halides, for example methyl chloride, ethyl chloride, butyl chloride, ethyl bromide, butyl bromide, benzyl chloride, lauryl chloride, stearyl chloride or behenyl chloride and dimethyl sulfate. A further modification of cyclodextrin is also possible by reaction with chloroacetic acid. Derivatives of cyclodextrins which contain cyclodextrin structures can also be obtained by enzymatic linkage with maltose oligomers. Examples of reaction products of the type specified above are dimethyl-β-cyclodextrin, hydroxypropyl-β-cyclodextrin and sulfonatopropylhydroxypropyl-β-cyclodextrin. Of the compounds of group (a), use is preferably made of α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin and / or 2,6-dimethyl-β-cyclodextrin.

The compounds of group (b) include water-insoluble or at most up to 20 g / l of ethylenically unsaturated monomers which are soluble in water at 20 ° C. Examples of such compounds are C ₂ - to C ₄ o-alkyl esters of acrylic acid or Cx * to C ₄ o-alkyl esters of methacrylic acid, such as methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, n-butyl acrylate , n-butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, tert-butyl acrylate, pentyl acrylate, pentyl methacrylate, n-hexyl acrylate, n-hexyl methacrylate, n-heptyl acrylate, n-heptyl methacrylate, n-octyl acrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, decyl acrylate, decyl methacrylate, lauryl acrylate, lauryl methacrylate, palmityl acrylate, palmityl methacrylate, octadecyl acrylate, octadecyl methacrylate, phenoxyethyl acrylate, phenoxyethyl methacrylate, phenyl acrylate and phenyl methacrylate.

Other monomers of group (b) are α-olefins with 2 to 30 C atoms and polyisobutylenes with 3 to 50, preferably 15 to 35, isobutene units. Examples of α-olefins are ethylene, propylene, n-butene, isobutene, pentene-1, cyclopentene, hexene-1, cyclohexene, octene-1 and diisobutylene (2,4,4-trimethyl-1-pentene, if appropriate in a mixture with 2,4,4-trimethyl-2-pentene), decene-1, dodecene-1, octadecene-1, C ₂ / -C ₄ -olefins, C ₂₀ / C ₂₄ -olefins, styrene, α-methylstyrene, polypropylene with terminal vinyl or vinylidene group with 3 to 100 propylene units, oligohexene or oligooctadecene.

Another class of monomers of group (b) are N-alkyl-substituted acrylamides and methacrylamides, such as N-tert. -Butyl acrylate, N-hexyl methacrylamide, N-octyl acrylamide, N-nonyl methacrylamide, N-dodecyl methacrylamide, N-hexadecyl methacrylamide, N-methacrylamide caproic acid, N-methacrylamido decanoic acid, N, N-dibutyla crylamide, N-hydroxyethyl acrylamide and N-hydroxyethyl methacrylamide.

Other monomers of group (b) are vinyl alkyl ethers having 1 to 40 carbon atoms in the alkyl radical, for example methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, 2-ethylhexyl vinyl ether, decyl vinyl ether, dodecyl vinyl ether, octadecyl vinyl ether, 2- (Diethylamino) ethyl vinyl ether, 2- (di-n-butylamino) ethyl vinyl ether, methyl diglycol vinyl ether and the corresponding allyl ethers such as allyl methyl ether, allyl ethyl ether, allyl n-propyl ether, allyl isobutyl ether and allyl 2-ethylhexyl ether. Also suitable as compounds of group (b) are the water-insoluble or at most up to 20 g / 1 water-soluble esters of maleic acid and fumaric acid, which are derived from monohydric alcohols with 1 to 22

Derive carbon atoms, for example mono-n-butyl maleate, dibutyl maleate, monodecyl maleate, didododecyl maleate, monooctadecyl maleate and dioctadecale maleate. Also suitable are vinyl esters of saturated C ₃ to C ₄ o-carboxylic acids such as vinyl propionate, vinyl butyrate, vinyl valerate, vinyl 2-ethylhexanoate, vinyl decanoate, vinyl palmitate, vinyl stearate and vinyl laurate. Other group (b) monomers are methacrylonitrile, vinyl chloride, vinylidene chloride, isoprene and butadiene.

The above-mentioned monomers of group (b) can be used alone or in a mixture to prepare the complexes or in the polymerization. Preferred monomers (b) there are suitable in consideration Mende compounds are C ₂ - to C ₃ 0-alkyl esters of acrylic acid, Ci to _C3 o-alkyl esters of methacrylic acid, C ₂ - to C ₃₀ -α-olefins, Ci to C ₂ o-alkyl vinyl ether, styrene, butadiene, isoprene or mixtures thereof. Particularly preferred monomers (b) are methyl methacrylate, butyl acrylate, lauryl acrylate, stearyl acrylate, isobutene, hexene-1, diisobutene, dodecene-1, octadecene-1, polyisobutenes with 15 to 35 isobutene units, styrene, methyl vinyl ether, ethyl vinyl ether, Octadecyl vinyl ether or mixtures thereof.

Also suitable as monomers (b) are crosslinking monomers which have at least 2 ethylenically unsaturated, non-conjugated double bonds in the molecule. Such compounds are mostly used in a relatively small amount together with water-soluble monomers in order to produce water-swellable polymers. Such copolymers are important, for example, as water-absorbing polymers. The problem here is that you usually had to use water-soluble crosslinking agents in order to produce uniform polymers. According to the method according to the invention, it is also possible to dissolve very poorly in water or water-insoluble crosslinkers to be polymerized homogeneously into the resulting crosslinked copolymer with a predominant proportion of water-soluble monomers. Suitable crosslinkers of component (b) are, for example, divinylbenzene, diallyl phthalate, allyl vinyl ether and / or diallyl fumarate. The water-insoluble crosslinkers can be polymerized alone to give homopolymers or together with water-soluble monomers to give copolymers. If crosslinking agents are used in the copolymerization of water-soluble monomers, the amount of crosslinking agent, based on the amounts of monomers used in the polymerization, is 0.05 to 10, preferably 0.1 to 2,% by weight.

Complexes of (a) and (b) are prepared by the methods known from the prior art mentioned above. For example, a compound containing cyclodextrin and / or a cyclodextrin structure and at least one monomer (b) can be dissolved together in a solvent and the solution heated if necessary. After removal of the solvent, a crystalline complex remains. One molecule of the compounds (a) can contain up to two molecules of the monomers (b) bound in complex form. These complexes are referred to in the literature as host / guest complexes. The compounds containing cyclodextrins or cyclodextrin structures contain the water-insoluble monomer of group (b) in their cavities.

The complexes from the compounds of groups (a) and (b) can also be prepared, for example, by adding the individual components (a) and (b) to a solvent which, for example, only contains the cyclodextrins and / or cyclodextrin structure. Compounds containing compounds dissolves, but not the water-insoluble monomers. The process of forming the host / guest complexes can be accelerated by heating, stirring, ultrasound treatment or other mechanical or thermal measures. The complexes can also be formed from the compounds (a) and (b) in a solvent which only dissolves the monomers (b) but not the cyclodextrins. The complexes can also be formed in the absence of solvent and diluent if the compounds containing cyclodextrins and / or cyclodextrin structures are present in a sufficiently fine distribution and are brought into contact with the monomers (b). It is also possible to evaporate the monomers (b) and to act on the cyclodextrins via the gas phase. Such a mode of operation is particularly preferred, for example, in the production of complexes from cyclodextrins and low-boiling monomers (b). For example, ethylene, propylene or isobutene can be passed over finely divided cyclodextrins. The formation of the complexes can take place under normal pressure, under reduced pressure or be done under increased pressure. The molar ratio of components (a): (b) is 1: 2 to 10: 1 and is preferably in the range from 1: 1 to 5: 1.

The hydrophobic monomers (b) can be radically polymerized alone or in a mixture with one another. It is also possible to subject at least one class of monomers (b) to the copolymerization with water-soluble monomers. Suitable water-soluble monomers, which are referred to below as monomers of group (c), are, for example, monoethylenically unsaturated C ₃ to C ₅ carboxylic acids, their amides and esters with amino alcohols of the formula

in which R = C ₂ - to Cs-alkylene, R ¹ , R ² , R ³ = H, CH ₃ , C ₂ H ₅ , C ₃ H ₇ and X® is an anion. Amides derived from amines of the formula are also suitable

deduce. The substituents in formula II and X® have the same meaning as in formula I.

These compounds are, for example, acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, acrylamide, methacrylamide, crotonic acid amide, dimethylaminoethyl acrylate, diethylaminoethylacrylate, dimethylaminoneopentyl acrylate and dimethylaminoethyl methacrylate and dimethylamino methyl amine methyl dimethyl amine methacrylate. The basic acrylates and methacrylates or basic amides derived from the compounds of the formula II are used in the form of the salts with strong mineral acids, sulfonic acids or carboxylic acids or in quaternized form. The anion XΘ for the compounds of formula I is the acid residue of the mineral acids or the carboxylic acids or methosulfate, ethosulfate or halide from a quaternizing agent.

Further water-soluble monomers of group (c) are N-vinylpyrrolidone, N-vinylformamide, acrylamidopropanesulfonic acid, vinylphosphonic acid and / or alkali metal or ammonium salts of the vinyl sulfonic acid. The other acids can also be used in the polymerization either in non-neutralized form or in partially or up to 100% neutralized form. Also suitable as water-soluble monomers of group (c) are dialylammonium compounds, such as dimethyldiallylammonium chloride, diethyldiallylammonium chloride or diallylpiperidinium bromide, N-vinylimidazolium compounds, such as salts or quaternization products of N-vinylimidazole and l-vinyl-2-methylimidazole, such as N-vinylimidazoline, l-vinyl-2-methylimidazoline, l-vinyl-2-ethylimidazoline or l-vinyl-2-n-propylimidazoline, which are also used in quaternized form or as a salt in the polymerization.

Preferred monomers of group (c) are monoethylenically unsaturated C ₃ to C ₅ carboxylic acids, vinyl sulfonic acid, acrylamido methyl propane sulfonic acid, vinyl phosphonic acid, N-vinyl formamide, dimethylaminoethyl (meth) acrylates, alkali metal or ammonium salts of the monomers or mixtures mentioned mentioned of the monomers with each other. The use of acrylic acid or mixtures of acrylic acid and maleic acid or their alkali metal salts in the production of hydrophobically modified water-soluble copolymers is of particular economic importance.

In order to produce crosslinked polymers which are used, for example, as superabsorbers or thickeners for aqueous systems, at least one monomer from group (c), for example acrylic acid, is polymerized with at least one complex of compounds containing cyclodextrins and / or cyclodextrin structures and at least one Class of crosslinking monomers which have at least two ethylenically unsaturated, non-conjugated double bonds in the molecule and are insoluble in water. The crosslinked polymers can optionally also be prepared in the presence of crosslinkers which are soluble in water and likewise have at least two ethylenically unsaturated, non-conjugated double bonds in the molecule. Such monomers are, for example, N, N '-methylene-bisacrylamide, polyethylene glycol diacrylates and polyethylene glycol dimethacrylates, which are each derived from polyethylene glycols with a molecular weight of 126 to 8500, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, ethylene glycol diacrylate, hexylene glycol diacrylate diacrylate diacrylate diacrylate diacrylate diacrylate, Diacrylates and dimethacrylates of block copolymers of ethylene oxide and propylene oxide, polyhydric alcohols esterified twice or three times with acrylic acid or methacrylic acid, such as glycerol or pentaerythritol, triallylamine, tetraallylethylenediamine, trimethylolpropane diallyl ether, pentaerythritol triallyl ether and / or N, N '-divinylethylene urea. The water-soluble crosslinking agents are preferably used in amounts of 0.01 to 2.0% by weight, based on the total monomers used in the copolymerization.

The polymerization of the water-insoluble monomers and, if appropriate, the water-soluble monomers takes place in the manner of a solution or precipitation polymerization in an aqueous medium, preferably in water. In the present context, aqueous medium should be understood to mean mixtures of water and thus miscible organic liquids. Water-miscible organic liquids are, for example, glycols such as Ethylen¬ glycol, propylene glycol, block copolymers of ethylene oxide and propylene oxide, alkoxylated C -.- to C ₂ o-alcohols, Essigsäureester of glycols and polyglycols, alcohols such as methanol, ethanol, isopropanol and butanol, acetone , Tetrahydrofuran, dimethylformamide, N-methylpyrrolidone or also mixtures of the solvents mentioned. If the polymerization takes place in mixtures of water and water-miscible solvents, the proportion of water-miscible solvents in the mixture is up to

45% by weight. However, the polymerization is preferably carried out in water.

The solution or precipitation polymerization of the monomers is usually carried out with the exclusion of oxygen at temperatures of, for example, 20 to 200, preferably 35 to 140 ° C. The polymerization can be carried out batchwise or continuously. Preferably, at least some of the monomers, initiators and optionally regulators are metered uniformly into the reaction vessel during the polymerization. In the case of smaller batches, however, the monomers and the polymerization initiator can also be initially introduced and polymerized in the reactor, where appropriate cooling must be used to ensure that the heat of polymerization is sufficiently rapidly removed.

Possible polymerization initiators are the compounds which are customarily used in free-radical polymerizations and which give free radicals under the polymerization conditions, for example peroxides, hydroperoxides, peroxodisulfates, percarbonates, peroxiesters, hydrogen peroxide and azo compounds. Examples of initiators are hydrogen peroxide, dibenzoyl peroxide, dicyclohexyl peroxide dicarbonate, dilauryl peroxide, methyl ethyl ketone peroxide, acetylacetone peroxide, tert. -Butyl hydroperoxide, cumene hydroperoxide, tert. Butyl perneodecanoate, tert. -Amyl perpivalate, tert. Butyl perpivalate, tert. Butyl perneohexanoate, tert. -Butylper-2-ethyl¬ hexanoate, tert. -Butyl perbenzoate, lithium, sodium, potassium and ammonium peroxydisulfate, azoisobutyronitrile, 2, 2 '-azo- bis (2-amidinopropane) dihydrochloride, 2- (carbamoylazo) isobutyronitrile and 4,4'-azobis (4-cyanovaleric acid). The initiators are usually used in amounts of up to 15, preferably 0.02 to 10,% by weight, based on the monomers to be polymerized.

The initiators can be used alone or as a mixture with one another. The use of the known redox catalysts, in which the reducing component is used in molar deficiency, are also suitable. Known redox catalysts are, for example, salts of transition metals such as iron (II) sulfate, cobalt (II) chloride, nickel (II) sulfate, copper (I) chloride, manganese (II) acetate, vanadium (III) acetate. Redox catalysts also include reducing sulfur compounds, such as sulfites, bisulfites, thiosulfates, dithionites and tetrathionates of alkali metals and ammonium compounds, or reducing phosphorus compounds in which phosphorus has an oxidation number of 1 to 4, such as sodium hypophosphite and phosphorous acid and phosphites.

In order to control the molecular weight of the polymers, the polymerization can optionally be carried out in the presence of regulators. Suitable regulators are, for example, aldehydes such as formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde and isobutyraldehyde, formic acid, ammonium formate, hydroxylammonium sulfate and hydroxylammonium phosphate. It is also possible to use regulators which contain sulfur in organically bound form, such as organic compounds having SH groups, such as thioglycol acetic acid, mercaptopropionic acid, mercaptoethanol, mercaptopropanol, mercaptobutanols, mercaptohexanol, dodecyl mercaptan and tert. -Dodecyl mercaptan. Salts of hydrazine such as hydrazinium sulfate can also be used as regulators. The amounts of regulator, based on the monomers to be polymerized, are 0 to 20, preferably 0.5 to 15,% by weight.

According to the invention, the polymerization can also be carried out in bulk. This is possible because the complexes from (a) and (b) are compatible with the water-soluble monomers, so that no phase separation occurs during the copolymerization.

If the water-insoluble monomers are not introduced into the reactor in the form of complexes of cyclodextrins and water-insoluble monomers from group (b) during the polymerization, the water-insoluble monomers (b) can be introduced into an aqueous solution of compounds containing cyclodextrins and / or cyclodextrin structures meter in and undergo the polymerization in the presence of polymerization initiators and optionally regulators. fen. In the reaction medium, host / guest complexes are formed from the water-insoluble monomers (b) and the compounds present therein and contain cyclodextrins and / or cyclodextrin structures, which permit the production of uniform homopolymers and copolymers. The cyclodextrins can also form host / guest complexes with water-soluble monomers.

The polymers are optionally 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 usually present separately from the compounds (a). For example, copolymers of acrylic acid with a content of water-insoluble monoethylenically unsaturated compounds such as stearyl acrylate or polyisobutene of more than 20% by weight precipitate out of the aqueous reaction solution. If the polymers are present in the form of inclusion compounds after production, they can be added, for example, by adding e.g. Wetting agents such as long chain ethoxylated alcohols are released to the reaction mixture from the inclusion compounds and isolated. The polymers modified hydrophobically by the processes according to the invention can be used, for example, as thickeners, e.g. in cosmetic creams or lotions, as a component in lacquer formulations, as sizing agents for papermaking, as a coating material, as adhesive raw material, as a detergent additive or as a dispersant for pigments. Such polymers can also be used as tanning, retanning, fatliquoring or water repellents for leather production. Hydrophobically modified polymers also serve as polymeric emulsifiers which stabilize a fine distribution of a non-polar substance in a polar phase. Crosslinked polyacrylic acids, which are obtainable, for example, by copolymerizing acrylic acid in the presence of at least one complex of cyclodextrin and a water-insoluble crosslinking agent such as divinylbenzene, are used as superabsorbents or thickeners for aqueous systems.

Examples

Production of complex I.

Preparation of a complex of 2,6-dimethyl-β-cyclodextrin (DMCD) - and N-hexyl methacrylamide in a molar ratio of 1: 1

6.4 g of N-hexyl methacrylamide were dissolved in 50 g of 2,6-dimethyl-β-cyclodextrin (DMCD) in 100 g of chloroform and stirred at room temperature for 48 hours. The solvent was distilled off and that resulting product dried. A white solid product was obtained in a yield of 96%.

Complexes II - IX

Analogously to the preparation of complex I, complexes of monomers specified in the table were prepared with DMCD in a molar ratio of 1: 1.

10

15

20th

example 1

Homopolymerization of complex I

25

60.0 g of complex I of N-hexyl methacrylamide / DMCD are dissolved in 200.0 g of water. 0.25 g of potassium per sulfate and 0.10 g of potassium pyrosulfite (K ₂ S ₂ O ₅ ) are added to the solution. The mixture was polymerized at 50 ° C. with the exclusion of oxygen. To

The resulting polymer was separated and dried for 30 to 24 hours. The polymer was obtained in 94% yield.

Examples 2 to 6

Homopolymers of complexes II to VI were prepared analogously to Example 1. The yields are given in the following table.

Example 7

Copolymerization of complex I with acrylic acid (1: 1 molar)

60.0 g of complex I of N-hexyl methacrylamide / DMCD and 2.8 g of acrylic acid are dissolved in 200.0 g of water. 0.25 g of potassium persulfate and 0.10 g of potassium pyrosulfite (K ₂ S ₂ 0 ₅ ) are added to the solution. The mixture was polymerized at 50 ° C. with exclusion of oxygen. After 24 hours, the polymer formed was separated off and dried. The polymer was obtained in a yield of 91%.

Examples 8-12

The complexes II, V, VII, VIII and IX were polymerized in analogy to Example 7 with the monomers specified in the table below.

The mixture of A and B was used 1: 1 molar to form the complex, the molar ratio A: B = 2: 1.

Claims

claims

1. A process for the preparation of polymers from water-insoluble monomers and optionally water-soluble monomers by free-radical polymerization of the monomers in a diluent, characterized in that the polymerization is carried out in water as a diluent and the water-insoluble monomers are in the form of complexes

(a) Compounds containing cyclodextrins and / or cyclodextrin structures and

(b) water-insoluble or at most up to 20 g / 1 at 20 ° C water-soluble ethylenically unsaturated monomers

in a molar ratio (a): (b) of 1: 2 to 10: 1 or the monomers are polymerized in the presence of up to 5 mol, based on 1 mol of the monomers (b), of compounds containing cyclodextrins and / or cyclodextrin structures .

2. The method according to claim 1, characterized in that as monomers (b) C ₂ - to C ₃ o-alkyl esters of acrylic acid, Ci- to C ₃₀ -alkyl esters of methacrylic acid, C ₂ - to C ₃ rj-α-01efine , Ci to C ₂ o * alkyl vinyl ether, styrene, butadiene, isoprene or mixtures thereof.

3. The method according to claim 1 or 2, characterized in that as monomers (b) crosslinking monomers are used which have at least two ethylenically unsaturated, non-conjugated double bonds in the molecule.

4. The method according to claim 1 or 2, characterized in that as monomers (b) butyl acrylate, lauryl acrylate, methyl methacrylate, stearyl acrylate, isobutene, 1-hexene, diisobutene,

Dodecen-1, octadecen-1, polyisobutene with 15 to 35 isobutene units, styrene, methyl vinyl ether, ethyl vinyl ether, ocadecyl vinyl ether or mixtures thereof.

5. The method according to claim 3, characterized in that the crosslinking monomers used are divinylbenzene, diallyl phthalate, allyl vinyl ether and / or diallyl fumarate.

6. The method according to claims 1 to 5, characterized in that as water-soluble monomers monoethylenically unsaturated C ₃ - to C ₅ -carboxylic acids, vinylsulfonic acid, acrylic amidomethylpropanesulfonic acid, vinylphosphonic acid, N-Vinylfor- mamide, dialkylaminoethyl (meth) acrylates, alkali metal or ammonium salts of the monomers mentioned containing acid groups, or mixtures of the monomers with one another.

7. The method according to claim 1, characterized in that the water-soluble monomers used are acrylic acid, mixtures of acrylic acid and maleic acid or the alkali metal salts of the monomers mentioned.

8. The method according to claim 1, characterized in that as component (a) α-cyclodextrin, β-cyclodextrin, γ-Cyclo¬ dextrin and / or 2,6-dimethyl-β-cyclodextrin is used.

9. The method according to claim 1, characterized in that 2,6-dimethyl-ß-cyclodextrin is used as component (a).

10. Use of the polymers obtainable according to claims 1 to 9 as sizing agents for paper manufacture, as coating agents, as thickeners for aqueous systems, as detergent additives and as thickeners in cosmetic creams or lotions.