EP1807471A1

EP1807471A1 - Method for producing polymers modified by silicone

Info

Publication number: EP1807471A1
Application number: EP05806523A
Authority: EP
Inventors: Kurt Stark; Christian HÖGL
Original assignee: Wacker Chemie AG
Current assignee: Wacker Chemie AG
Priority date: 2004-11-04
Filing date: 2005-10-20
Publication date: 2007-07-18
Also published as: US20090104238A1; KR20070084629A; BRPI0517779A; TW200635966A; CN101056931A; JP2008519114A; DE102004053314A1; WO2006048133A1

Abstract

The invention relates to a method for producing polymers, which are modified by silicone, from ethylenically unsaturated monomers in the form of their aqueous polymer dispersions or polymer powders that can be redispersed in water. The invention is characterized in that: A) a prepolymer is produced by polymerizing one or more ethylenically unsaturated monomers and at least one silicone macromer with ethylenically unsaturated groups and is isolated; B) the prepolymer obtained thereby is dissolved in one or more ethylenically unsaturated monomers; C) this solution is emulsified in water and radically polymerized, and optionally; D) the hereby obtained aqueous dispersion of the polymers modified by silicone is dried.

Description

Process for the preparation of silicone-modified polymers

The invention relates to a process for the preparation of silicone-modified polymers of ethylenically unsaturated monomers in the form of their aqueous polymer dispersions or water-redispersible polymer powders.

Various processes for the preparation of polymer dispersions of copolymers modified with silicones are known from the prior art. EP-A 771826 discloses a process for the preparation of a crosslinked silicone copolymer latex, in which initially water, monomer, emulsifier and water-soluble initiator are initially charged, the reaction is started, further monomer is slowly metered in, and finally the crosslinking agent Silicone, which is short-chain and polyunsaturated, is added together with the remaining monomer.

In EP-A 614924, only short-chain silicone macromers are used in the emulsion polymerization since longer-chain silicone macromers do not reasonably polymerize with the organic monomers. The free-radically polymerizable groups ent holding silicone and the vinyl monomer are emulsified in each case in the aqueous phase and the polymerization gestar¬ tet. US Pat. No. 6,609,949 describes the preparation of silicone-organopolymer graft polymers, in which a branched, short-chain silicone having a dendrimeric structure with ethylenically unsaturated radical, ethylenically unsaturated monomers and free-radically polymerizable emulsifier are reacted in the presence of an oil-soluble initiator. The dendritic structure of the short-chain silicone macromer improves the copolymerization with organic monomers. It is shown in comparative examples that long-chain silicone macromers (without dendrimeric structure) have polymerized only up to a maximum of 75% with organic monomers and a large amount of unreacted silicone macromer remains. In EP-A 810243 are silicone macromers with organic monomers in Emulsion polymerized, being carried out exclusively with oil-soluble initiator. A disadvantage of the methods under initiation with oil-soluble initiator is the insufficient stability of the resulting dispersions, which are very prone to phase separation.

US Pat. No. 5,618,879 describes the copolymerization of a mixture of silicone macromer and monomer emulsified with anionic emulsifier in water, the polymerization being initiated with water-soluble initiator. In JP-A 05-140255 a silicone macromer containing free-radically polymerizable groups is dissolved in the organomonomer, the solution is emulsified in water with anionic emulsifier and the polymerization is started with water-soluble initiator. Another disadvantage here is that a considerable proportion, of more than 20%, of the silicone macromer is not copolymerized.

JP-A 09-052923 describes a process for the preparation of silicone-containing graft polymers in which first a mixture of organopolysiloxane and ethylenically unsaturated silane is polymerized and then vinyl monomer is added in two stages for grafting.

The processes known from the prior art have in common that the copolymerization of the silicone macromers with organic monomers in emulsion is always inadequate. This leads to free silicone remaining in the dispersion, with corresponding disadvantageous consequences: the silicone migrates from coatings or films. The dispersion can coagulate. The particle size distribution is inhomogeneous. In addition, the storage stability is negatively influenced by the tendency to phase separation.

It is an object of the present invention to provide silicone-modified polymers of ethylenically unsaturated monomers in which the silicon moiety is present in a form which largely prevents the migration of free silicone. The invention relates to a process for the preparation of silicone-modified polymers of ethylenically unsaturated monomers in the form of their aqueous polymer dispersions or water-redispersible polymer powder, characterized in that

A) a prepolymer is prepared and isolated by polymerization of one or more ethylenically unsaturated monomers and at least one silicone macromer having ethylenically unsaturated groups,

B) the prepolymer thus obtained is dissolved in one or more ethylenically unsaturated monomers,

C) this solution is emulsified in water and free-radically polymerized, and optionally D) the aqueous dispersion of the polymers modified with silicone is dried.

For the preparation of the prepolymer, one or more monomers are used as ethylenically unsaturated monomers from the group comprising vinyl esters of unbranched or branched alkylcarboxylic acids having 1 to 15 carbon atoms, methacrylic acid esters and acrylic esters of alcohols having 1 to 15 carbon atoms. Atoms, vinyl aromatics, olefins, dienes and vinyl halides. In general, from 1 to 99% by weight of the ethylenically unsaturated monomers are used, preferably from 40 to 95% by weight, based in each case on the total weight of silicone macromer and monomer.

Suitable vinyl esters are vinyl esters of unbranched or branched carboxylic acids having 1 to 15 carbon atoms. Preferred vinyl esters are vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate, vinyl laurate, 1-methylvinyl acetate, vinyl pivalate and vinyl esters of α-branched monocarboxylic acids having 5 to 13 C atoms, for example VeoVa9 ^R or VeoVal0 ^R ( Trading name of the company Resolution Performance Products). Particularly preferred is vinyl acetate.

Suitable monomers from the group of esters of acrylic acid or methacrylic acid are esters of unbranched or branched ver¬ branched alcohols having 1 to 15 carbon atoms. Preferred methacrylic esters or acrylates are methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, polypropyl acrylate, propyl methacrylate, n-, iso- and t-butyl acrylate, n-, iso- and t-butyl methacrylate, 2-ethylhexyl acrylate, norboyl acrylate , Particularly preferred are methyl acrylate, methyl methacrylate, n-, iso- and t-butyl acrylate, 2-ethylhexyl acrylate and norbornyl acrylate.

Suitable dienes are 1,3-butadiene and isoprene. Examples of copolymerizable olefins are ethene and propene. As vinylaromatics, styrene and vinyltoluene can be copolymerized. From the group of vinyl halides usually vinyl chloride, vinylidene chloride or vinyl fluoride, preferably vinyl chloride, are used.

Optionally, 0.05 to 30 wt .-%, based on the total weight of the ethylenically unsaturated monomers, auxiliary monomers can be copolymerized. Examples of auxiliary monomers are ethylenically unsaturated mono- and dicarboxylic acids or their salts, preferably crotonic acid, acrylic acid, methacrylic acid, fumaric acid and maleic acid; ethylenically unsaturated carboxylic acid amides and nitrites, preferably acrylamide and acrylonitrile; Mono- and diesters of fumaric acid and maleic acid, such as the diethyl and diisopropyl esters and maleic anhydride, ethylenically unsaturated sulfonic acids or salts thereof, preferably vinylsulfonic acid, 2-acrylamiclo-2-methylpropanesulfonic acid. Also suitable as auxiliary monomers are cationic monomers such as diallyldimethylammonium chloride (DADMAC), 3-trimethylammoniumpropyl (meth) acrylamidechloroLd (MAPTAC) and 2-trimethylammoniumethyl (meth) acrylate chloride. Further suitable as auxiliary monomers are vinyl ethers, vinyl ketones, further vinylaromatic compounds which may also have heteroatoms.

Suitable auxiliary monomers are also polymerisable silanes or. Mercaptosilanes. Preference is gamma-acrylic or. gamma-meth acryloxypropyltri (alkoxy) silanes, α-methacryloxymethyltri (alkoxy) silanes, gamma-methacryloxypropylmethyldi (alkoxy) silanes, vinylalkyldi (alkoxy) silanes and vinyltri (alkoxy) silanes, alkoxy groups being, for example, methoxy, ethoxy, methoxyethylene , Ethoxyethylene, Methoxypropylenglykolether- or

Ethoxypropylenglykolether residues can be used. Examples of these are vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, vinyltriisopropoxysilane, vinyltris (1-methoxy) isopropoxysilane, vinyltributoxysilane, vinyltriacetoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-imethacryloxypropylmethyldimethoxysilane, methacryloxymethyltrimethoxysilane, 3-methacryloxypropyltris (2-methoxyethoxy) silane, vinyltrichlorosilane, vinylmethyldichlorosilane, vinyltris (2-methoxyethoxy) silane, trisacetoxyvinylsilane, 3- (triethoxysilyl) propylsuccinic anhydride silane. Also preferred are 3-

Mercaptopropyltriethoxy silane, 3-mercaptopropyltrimethoxysilane and 3-mercaptopropylmethyldimethoxysilane.

Further examples are functionalized (meth) acrylates and functionalized alcohols and vinyl ethers, in particular epoxy-functional compounds such as glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, vinyl glycidyl ether or hydroxyalkyl functionals such as hydroxyethyl (meth) acrylate, or substituted or unsubstituted aminoalkyl (meth) acrylates, or cyclic monomers, such as N-vinylpyrrolidone; or N-vinylformamide.

Further examples of suitable auxiliary monomers are precursor comonomers, such as polyethylenically unsaturated comonomers, for example divinyl adipate, divinylbenzene, diallyl maleate, allyl methacrylate, butanediol diacrylate or triallyl cyanurate, or postcrosslinking comonomers, for example acrylamidoglycolic acid (AGA), methyl acrylamidoglycolate methyl ester (MAGME ), N-methylolacrylamide (NMA), N-methylolmethacrylamide, N-methylolallyl carbamate, alkyl ethers such as the isobmoxyether or esters of N-methylolacrylamide, N-methylolmethacrylamide and N-methylolallylcarbamate. Silicone macromers which are suitable for the preparation of the prepolymer are linear, branched, cyclic and three-dimensionally crosslinked polysiloxanes having at least 10 siloxane repeat units and having at least one free-radically polymerizable functional group. Preferably, the chain length is 10 to 10,000 siloxane repeating units. Etlrylenisch unsaturated groups such as alkenyl groups are preferred as polymerizable functional groups.

Preferred silicone macromers are silicones having the general formula R ¹ _a R ₃ - _a SiO (SiR ₂ O) _n SiR3- _a R ¹ a / wherein R is the same or the verschie¬ and is a monovalent, optionally substituted, alkyl radical or alkoxy radical having in each case 1 to 18 carbon atoms meaning tet, R ^{1 is} a polymerizable group, a is 0 or 1, and n = 10 to 10,000.

In the general formula R ¹ _a R3 _a SiO (SiR ₂ O) _n SiR3- _a R ¹ a Bei¬ are games for R methyl, ethyl, n-propyl, iso-propyl, 1-n- Butyl, 2-n-butyl, iso-butyl, tert. Butyl, n-pentyl, iso-pentyl, neo-pentyl, tert-pentyl, hexyl such as the n-hexyl, heptyl such as the n-heptyl, octyl such as the n-octyl and iso-octyl such as 2, 2,4-trimethylpentyl radical, nonyl radicals such as the n-nonyl radical, decyl radicals such as the n-decyl radical, dodecyl radicals such as the n-dodecyl radical, and octadecyl radicals such as the n-octadecyl radical, cycloalkyl radicals such as cyclopentyl, Cyclohexyl, cycloheptyl and methylcyclohexyl radicals. The radical R is preferably a monovalent hydrocarbon radical having 1 to 6 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, A-methyl and hexyl Radical, the methyl radical being particularly preferred.

Preferred alkoxy radicals R are those having 1 to 6 carbon atoms, such as methoxy, ethoxy, propoxy and n-butoxy radicals, which may optionally also be substituted by oxyalkylene radicals, such as oxyethylene or oxymethylene radicals. Particularly preferred are the methoxy and ethoxy. The stated alkyl radicals and alkoxy radicals R may optionally also be sub- may be substituted, for example, with halogen, mercapto groups, epoxy-functional groups, carboxy groups, keto groups, enamine groups, amino groups, aminoethylamino groups, isocyanate groups, aryloxy groups, alkoxysilyl groups and hydroxyl groups.

Suitable polymerizable groups R ¹ are alkenyl radicals having 2 to 8 C atoms. Examples of such polymerizable groups are the vinyl, allyl, butenyl, and acryloxyalkyl and methacryloxyalkyl group, wherein the alkyl radicals contain 1 to 4 carbon atoms. Preference is given to the vinyl group, 3-methacryloxypropyl, acryloxymethyl and 3-acryloxypropyl group.

Preference is given to α, ω-divinyl-polydimethylsiloxanes, α, ω-di- (3-acryloxypropyl) polydimethylsiloxanes, α, ω-di- (3-methacryloxypropyl) polydimethylsiloxanes. In the case of the silicones which are only substituted by unsaturated groups, α-monovinyl-poly-dimethylsiloxanes, α-mono- (3-acryloxypropyl) -polydimethylsiloxanes, α-mono- (acryloxymethyl) -polydimethylsiloxanes, α-mono- (3 - methacryloxypropyl) -Polydimethylsiloxane preferred. In the case of the monofunctional polydimethylsiloxanes, an alkyl or alkoxy radical, for example a methyl or butyl radical, is located at the other end of the chain.

Preference is also given to mixtures of linear or branched divinyl-polydimethylsiloxanes with linear or branched monovinyl-polydimethylsiloxanes and / or unfunctionalized polydimethylsiloxanes (the latter have no polymerizable group). The vinyl groups are at the end of the chain. Examples of such mixtures are silicones of the solvent-free Dehesive ^s -6 series (branched) or Dehesive ^<D -9 series (unbranched) of Wacker-Chemie GmbH. In the binary or ternary mixtures, the proportion of unfunctional polydialkylsiloxanes is at most up to 15% by weight, preferably up to 5% by weight; the proportion of monofunctional polydialkylsiloxanes up to 50% by weight; and the proportion of the difunctional Polydialkylsilo¬ xane at least 50 wt .-%, preferably at least 60 wt .-%, each based on the total weight of the Silikonmakromers. Also suitable are the polymerizable Silikonmakroraere, as described in EP-A 614924.

Most preferred as silicone macromers are α, ω-divinyl-polydimethylsiloxanes, α-mono- (3-methacryloxypropyl) -polydimethylsiloxanes and α, ω-di- (3-methacryloxypropyl) -polydimethylsiloxanes.

The preparation of the prepolymer in step A) takes place by means of radical polymerization by mass, solution, suspension or emulsion polymerization in an aqueous medium. Preference is given to the solution polymerization process and the suspension polymerization process. Suitable solvents are esters such as methyl acetate and ethyl acetate, ketones such as acetone and methyl ethyl ketone, alcohols such as methanol, ethanol, t-butanol, isopropanol, or mixtures thereof.

The polymerization is usually carried out in a, temperature-interval of 20 ⁰ C to 100 ⁰ C, in particular between 40 ⁰ C and 80 ⁰ C. The silicone macromer with ethylenically ungesättig¬ th groups in an amount of 1 to 99 wt .-%, preferably used 5 to 60 wt .-%, in each case based on the total weight of silicone macromer and ethylenically unsaturated monomer. Initiation takes place by means of free-radical initiators (initiators), which are preferably used in amounts of from 0.01 to 5.0% by weight, based on the total weight of silicone macromer and monomer. It is possible to work with water-soluble or oil-soluble initiator or mixtures thereof.

Suitable water-soluble initiators are those whose solubility in water under standard conditions is> 10% by weight. For example, water-soluble, inorganic peroxides, such as ammonium, sodium, potassium peroxodisulfate or hydrogen peroxide, either alone or in combination with reducing agents, such as sodium sulfite, sodium hydrogen sulfite, sodium formaldehyde sulfoxylate or ascorbic acid. It is also possible to use water-soluble organic peroxides, for example t-butyl hydroperoxide (TBHP), cumene hydroperoxide, usually in combination with reducing agent, are used, or even wasserlös¬ Liche azo compounds.

Oil-soluble initiators are those whose solubility in water under standard conditions is <1% by weight. Representatives of the group of oil-soluble initiators are initiators such as t-butyl peroxy-2-ethylhexanoate (TBPEH), t-butyl peroxypivalate (PPV), t-butyl peroxyneodecanoate (TBPND), dibenzoyl peroxide, t-amyl peroxypivalate (TAPPI), di - (2-ethylhexyl) peroxy dicarbonate (EHPC), 1, 1-bis (t-butylperoxy) -3, 3, 5-trimethylcyclohexane and di (4-t-butylcyclohexyl) peroxydicarbonat einge¬ sets. Suitable oil-soluble initiators are also azo initiators such as azobisisobutyronitrile (AIBN).

In the copolymerization with gaseous monomers such as ethylene and vinyl chloride is carried out under pressure, generally between 1 and 100 bar _a bs ..

Optionally, the usual regulators may be used to control the molecular weight, for example alcohols such as isopropanol, aldehydes such as acetaldehyde, chlorine-containing compounds, mercaptans such as n-dodecylmercaptan, t-dodecylmercaptan, mercaptopropionic acid (ester). To adjust the pH, pH-regulating compounds such as sodium acetate or formic acid can be used in the preparation of the dispersion.

If polymerization is carried out in an aqueous phase, the emulsifiers and protective colloids mentioned in the description of step C) can also be used for stabilization.

The polymerization can be carried out independently of the polymerization process with the introduction of all or individual constituents of the reaction mixture, or with partial introduction and subsequent metering of the or individual constituents of the reaction mixture, or after the metering process without preparation. Upon completion of the polymerization, the prepolymer becomes isolated. Depending on the polymerization process, in a known Wei¬ se, by means of filtration, precipitation or distilling off the Lö¬ sungsmittels.

The prepolymers thus obtained are dissolved in one or more ethylenically unsaturated monomers in the next step. The proportion of prepolymer in the solution is preferably from 5 to 60% by weight, based on the total weight of prepolymer and ethylenically unsaturated monomer. Suitable ethylenically unsaturated monomers are the monomers already mentioned under step A) from the group comprising vinyl esters of branched or unbranched alkylcarboxylic acids having 1 to 15 carbon atoms, methacrylic acid esters and acrylic esters of alcohols having 1 to 15 carbon atoms, vinylaromatics, Olefins, dienes and vinyl halides, and optionally also additionally the aforementioned auxiliary monomers in the stated amounts.

Preference is given to vinyl acetate; Mixtures of vinyl acetate and ethylene; Mixtures of vinyl acetate with further vinyl esters such as vinyl laurate, vinyl pivalate, vinyl 2-ethylhexanoic acid ester, vinyl ester of an alpha-branched carboxylic acid, in particular vinyl versatate (VeoVa9 ^R , VeoVal0 ^R ), and optionally ethylene; Mixtures of vinyl ester, ethylene and vinyl chloride, vinyl esters preferably vinyl acetate and / or vinyl propionate and / or one or more copolymerizable vinyl esters such as vinyl laurate, vinyl pivalate, vinyl 2-ethylhexanoic acid ester, vinyl ester of an alpha-branched carboxylic acid , in particular Versaticsäurevinylester (VeoVa9 ^R , VeoVal0 ^R ), ent are keep; Vinyl ester-acrylic acid ester mixtures with vinyl acetate and / or vinyl laurate and / or Versatic acid vinyl ester and acrylic acid ester, in particular butyl acrylate or 2-ethylhexyl acrylate, which optionally also contain ethylene; Preference is also given to (meth) acrylic esters, such as methyl methacrylate, n-butyl acrylate and / or 2-ethylhexyl acrylate, and mixtures thereof; as well as styrene; Mixtures of styrene with meth) acrylic acid esters, such as butyl acrylate, methyl methacrylate, and / or 2- ethylhexyl acrylate; Mixtures of 1,3-butadiene with methyl methacrylate and / or styrene.

If appropriate, the abovementioned mixtures may also contain the stated auxiliary monomers in the stated amounts.

The solution of prepolymer and ethylenically unsaturated monomer is emulsified in water and preferably free-radically polymerized by the emulsion polymerization process. The polyvinyl lymerisation is usually carried out in a temperature range from 20 ⁰ C to 100 ⁰ C. Initiation takes place by means of free-radical initiators (initiators), which are preferably used in quantities of from 0.01 to 5.0% by weight, based on the total weight of silicone organocopolymer and monomer. It can be worked with water-soluble or oil-soluble initiator or a mixture of such initiators. Suitable water-soluble and oil-soluble initiators are those already mentioned above.

To stabilize the aqueous dispersion, it is possible to use anionic and nonionic emulsifiers and protective colloids, these also being able to comprise polymerizable groups. Nonionic or anionic emulsifiers are preferably used, more preferably a mixture of nonionic and anionic emulsifiers. The nonionic emulsifiers used are preferably condensation products of ethylene oxide or propylene oxide with linear or branched alcohols having 8 to 18 carbon atoms, alkylphenols or linear or branched carboxylic acids having 8 to 18 carbon atoms, and also block copolymers of ethylene oxide and propylene oxide. Suitable anionic emulsifiers are, for example, alkyl sulfates, alkyl sulfonates, alkylaryl sulfates, and sulfates or phosphates of condensation products of ethylene oxide with linear or branched alkyl alcohols and with 3 to 60 EO units, alkylphenols, and mono- or diesters of sulfosuccinic acid. The amount of emulsifier is 0.1 to 30

Wt .-%, based on the total weight of monomer used and prepolymer. Optionally, protective colloids can still be used. Examples of suitable protective colloids are polyvinyl alcohols having a content of 75 to 95 mol%, preferably 84 to 92 mol% vinyl alcohol units; Poly-N-vinylamides such as polyvinylpyrrolidones, polysaccharides such as starches, and celluloses and their carboxymethyl, methyl, hydroxyethyl, hydroxypropyl derivatives; synthetic polymers such as poly (meth) acrylic acid, poly (meth) acrylamide. It is also possible to use polyglycol ethers such as polyethylene glycol, polypropylene glycol or mixed polyalkylene oxides having ethylene oxide and propylene oxide groups. Particularly preferred is the use of said polyvinyl alcohols. Preference is also given to the use of polyalkylene oxides which have at least one but at most two polymerizable groups, for example the vinyl or the allyl group. The protective colloids are generally in an amount of from 0.1 to 30% by weight, based on the total weight of the monomer and prepolymer used.

The polymerization can be carried out independently of the polymerization process with or without the use of seed latexes, all or individual constituents of the reaction mixture being prepared, or with partial introduction and subsequent addition of the or individual constituents of the reaction mixture, or after the metered addition process without preparation. The prepolymer is always introduced dissolved in the monomer.

The emulsifiers and protective colloids can be initially charged for the preparation of the dispersion or metered in, or a portion is initially charged and the remainder is metered. The can surface-active substances alone or as a pre-emulsion with the comonomers containing the dissolved therein prepolymer contained dosed.

In the copolymerization of gaseous monomers such as ethylene, the desired amount is introduced by setting a bestimm¬ th pressure. The pressure with which the gaseous monomer is introduced can initially be set to a specific value and degrade during the polymerization, or the pressure is kept constant during the entire polymerization. The latter embodiment is preferred.

After completion of the polymerization can be nachpolymerisiert to the residual monomer removal in application of known methods, for example by redox catalyst initiated Nachpo¬ lymerisation. Volatile residual monomers and other volatile, non-aqueous constituents of the dispersion can also be removed by means of distillation, preferably under reduced pressure, and, if appropriate, by passing or passing inert inert gases, such as air, nitrogen or steam.

The aqueous dispersions obtainable by the process according to the invention have a solids content of from 20 to 70% by weight, preferably from 25 to 65% by weight. The setting of the Festge¬ haltes can also suc¬ by subsequent addition of water gene after the emulsion has been completed. For the preparation of polymer powders which are redispersible in water, the aqueous dispersions are dried, if appropriate after addition of protective colloids as atomization aid, for example by means of fluidized bed drying, freeze drying or spray drying. Preferably, the dispersions are spray-dried. The spray drying is carried out in conventional spray drying systems, wherein the atomization can be done by means of one-, two- or multi-fluid nozzles or with a rotating disk. The outlet temperature is generally in the range of 45 ° C to 120 ⁰ C, preferably 60 ⁰ C to 90 ⁰ C, depending on the system, Tg of the resin and the desired degree of drying selected. As a rule, the atomization aid is used in a total amount of from 3 to 30% by weight, based on the polymeric constituents of the dispersion. Suitable atomization aids are the already mentioned protective colloids. During atomization, a content of up to 1.5% by weight of antifoam, based on the base polymer, has proven to be favorable. To improve the blocking stability, the powder obtained can be equipped with an antiblocking agent (anticaking agent), preferably up to 30% by weight, based on the total weight of polymeric constituents. Examples of antiblocking agents are Ca or Mg carbonate, talc, gypsum, silicic acid, kaolins, silicates.

The procedure according to the invention makes it possible to obtain silicone-containing copolymers which are distinguished by complete attachment of the silicone fraction to the organic fraction, which is ensured by the separate preparation of the prepolymer. The dispersions thus obtained have a number of advantages: Advantageous Teilchengrö¬ ßenverteilung, storage stability, no phase separation, no sweating of the silicone, no specks and an ex¬ zellente film formation. Non-lubricating films with high cohesion and favorable mechanical behavior are obtained.

From the matrix with the organic polymer, the silicone can unfold its effect in the form of the previously formed silicone organocopolymer; B. lead to release behavior and hydrophobic behavior. The effect of the silicone organocopolymer can also be caused by thermal activation.

The copolymers in the form of their aqueous dispersions and water-redispersible powders are suitable for use in adhesives, coating compositions, as well as a protective coating z. B. for metals, foils, wood or release coating or for paper treatment, eg. B. in the tissue sector, as a binder for the consolidation of fibers or other particles ticular materials. They can also be used in the textile industry for textile treatment, coating, textile finishing or finishing, as well as in the area of fabric care, as modifiers and as water repellents, and they can also be used advantageously in the polish sector In addition, the dispersions can be used as release agents They are also suitable as binders in the construction sector for paints, adhesives and coating compositions, for example in tile adhesives and non-thermal protection adhesives, and especially for use in low-emissivity They can also be used as an additive, for example in paints or in cosmetic formulations, such as hairsprays, creams, lotions or shampoos.

The copolymers in the form of their aqueous dispersions and water-redispersible powders are furthermore suitable as binders for toners for producing silicone-modified toner particles.

The following examples serve to further illustrate the invention without limiting it in any way.

Preparation of the prepolymer:

Example a):

Prepolymer prepared by solution polymerization.

Composition 33 wt .-% polydimethylsiloxane and. 67% by weight

Vinyl acetate In a 120 l stirred tank with anchor stirrer, reflux condenser and metering devices, 51.05 kg of ethyl acetate, 8.01 kg of isopropanol, 983.4 g of an α, ω-divinyl-functionalized polydimethylsiloxane having 133 SiOMe ₂ repeat units (silicone macromer Wacker VIPO 300 ^Θ ), 51.3 g of tert-butyl perpivalate (initiator PPV) and 2.00 kg of vinyl acetate. Subsequently, the stirred tank was heated to 7O ⁰ C at a stirrer speed of 95 rpm. After reaching the internal temperature of 70 ⁰ C, the initiator feed (4.03 kg of ethyl acetate and 199.3 g PPV) at a rate of 819.0 g / h. Ten minutes after the start of the initiator feed was the Monomerdosie tion (7.88 kg Wacker silicone macromer VIPO 300 ^® and 15.99 kg of vinyl acetate) at a rate of 5.97 kg / h retracted. The iodine dosing extended over a period of 310 min, the monomer dosing ended 60 min earlier. After the end of both dosages further 120 min at 7O ⁰ C was nachpolymerisie rt. The 1-phase polymer solution obtained was then distilled in Rühr¬ kettle at 95 ° C and addition of 1000 ml of water and then at 12O ⁰ C for 1 h. Dried. After cooling to room temperature, a transparent resin was obtained. Analyzes: Composition of the Silicone Organocopolymer According to IH-NMR Spectroscopy: 33% by Weight of Silicone, 67% by Weight of Vinyl Acetate; FG: 99.90%, GC analysis: residual VAc content <5 ppm; Residual ethyl acetate 45 ppm; Residual isopropanol 10 ppm, acid number 1.80 mg KOH / g, viscosity (Hoppler, 10% solution in ethyl acetate) = 1.16 mPas, SEC M _w = 21700 g / mol, M _n = 4530 g / mol, polydispersity = 4.79; Tg = 24.3 ° C. IH-NMR spectroscopy has been used to prove that no free double bonds are present in the silicon copolymer. Thus, the silicone macromer is completely copolymerized with the organic monomer and there is no longer free silicone.

Example b):

Prepolymer prepared by suspension polymerization, composition 30.0% by weight polydimethylsiloxane (silicone), 70.0% by weight styrene In a 500 l stirred tank with stirrer, reflux condenser, metering device, heater (with temperature control) and nitrogen inlet, 237.35 kg of deionized Water, 771.94 g of copper acetate (1% aqueous solution) and 10.29 kg of polyvinylpyrrolidone (5% aqueous solution) submitted. The solution was stirred at 100 rpm. In the meantime, a mixture of 15.42 kg of an α-methacryloxypropyl-functionalized polydimethylsiloxane having 11 SiOMe ₂ repeating units (Chisso FM 0711) and 15.42 kg of an α-methacryloxypropyl-functionalized polydimethylsiloxane was included 63 SiOMe ₂ repeat units (Chisso FM 072IL) and 71.95 kg of styrene were prepared. A combination of two different initiators would be given to this monomer mixture. The initiators used were 1.80 kg of t-butylperoxyneodecanoate (95% by weight in aliphatics, half-life tl / 2 = 1 h at 64 ° C.) and 1.75 kg of t-butyl perpivalate (75% by weight in aliphatics, half-life tl / 2 = 1 h at 74 ° C). The monomer mixture with the initiators was stirred for a short time at room temperature and then added slowly to the aqueous receiver in the stirred tank. The kettle contents were mixed by stirring at 100 rpm, whereupon the monomers were suspended in water. Subsequently, the temperature was raised to 55 ⁰ C and held for 4 hours. Thereafter, the temperature was raised at a ramp of 0.1 ° C / min to 60 ⁰ C and held for 4 h. Then it was heated to 65 ° C. with a temperature ramp of 0.1 ° C./min. This temperature was held for 4 hours. Then it was heated to 7O ⁰ C with a temperature ramp of 0.1 ° C / min. This temperature was held for 4 hours. The temperature was then increased at a ramp of 0.1 ° C / min to 75 ⁰ C and held for 4 h. To polymerize auszupoly-, the temperature was raised to 80 ⁰ C and held for 2 hours. The batch was subjected to steam treatment to drive off volatile compounds and finally cooled to room temperature. The resulting beads were separated by a filtration step from the suspending medium, ie from the water. The beads were washed several times with water and then dried. Highly transparent, hard beads were obtained.

Analyzes: Composition according to IH-NMR spectroscopy: 30.0% by weight of silicone, 70.0% by weight of styrene. Molecular weight MW (mass agent from GPC, eluant THF): 312000 g / mol (based on polystyrene standards); Polydispersity D: 6.5; Glass transition temperature Tg (from DSC): 68 ° C.

It has been shown by IH-NMR spectroscopy that there are no longer any free double bonds in the silicone organocopolymer. Thus, the silicone macromer is completely copolymerized with the organic monomer and there is no longer free silicone. Preparation of the polymer dispersions:

Used raw materials:

Mersolat K30: Na alkyl sulfonate with 12 to 14 C atoms in the alkyl radical.

Genapol X050: C ₁₃ oxo alcohol ethoxylate with 5 EO Texapon K12: Na dodecyl sulfate

Genapol PF80: EO-PO block polymer with 80% EO. Brüggolith: sodium formaldehyde sulfoxylate (reducing agent) Polyvinyl alcohol W25 / 140: polyvinyl alcohol with a Viskosi¬ ty of about 25 mPas (20 ⁰ C, 4% solution, measured according to Höppler), and a saponification value of 140 (mg KOH / g polymer) ( Degree of hydrolysis 88 mol%).

Example 1:

622.0 g of W 25/140 (polyvinyl alcohol, 10% strength aqueous solution), 155.5 g of Genapol PF 80 (20% strength aqueous solution), 11.47 g of Mersolat K30 (in a 2 liter stirred apparatus with anchor stirrer and metering devices). 30% aqueous solution). For this purpose, a previously prepared solution of 311.0 g of a silicone organoclay of the composition 33.0 wt .-% silicone, 67.0 wt .-% vinyl acetate (prepared in Example a)), 2.62 g Trigonox 23 (tert-butyl peroxyneodecanoate, 95% in Aliphatic) in 311.0 g of vinyl acetate. This original was stirred at 300 rpm. With 10% formic acid was adjusted to pH = 5-5.5.

Subsequently, the kettle was heated to 60 ⁰ C. The temperature of 60 ⁰ C was maintained for 2 hours while stirring at 300 rpm.

After the end of the polymerization, the dispersion was treated with steam for stripping the residual monomer ("stripped") and then preserved with Hydorol W. The dispersion was diluted with 185 g of water before filling.A homogeneous and stable dispersion was obtained. Dispersion analyzes : Solids content: 44.2%; pH: 4.1; Brookfield viscosity 20 (spindle 7): 28200 mPas; MFT: 10 ⁰ C; Glass transition temperature Tg: 19.2 ° C; average particle size: 1653.5 nm (Nanosizer); Coulter: Dn (number average particle size) = 0.479 μm; Dv (volume average particle size) = 0.839 μm; Surface = 8.5 m ² / g.

Example 2: In a 2 liter stirred apparatus with anchor stirrer were

622.0 g of W 25/140 (polyvinyl alcohol, 10% strength aqueous solution), 146.0 g of Genapol PF 80 (20% strength aqueous solution), 10.77 g of K2 Moleolate (30% strength aqueous solution). For this purpose, a previously prepared solution of 292.0 g of a silicone organopolymers of the composition 33.0 wt .-% silicone, 67.0

% By weight of vinyl acetate (prepared in Example a)) in 292.0 g of vinyl acetate. This original was stirred at 300 rpm. With 10% formic acid was adjusted to pH = 5-5.5. Subsequently, the kettle was heated to 60 ⁰ C and it was stirred at 300 rpm. Once the reactor was in thermal equilibrium, an 8.7% aqueous TBHP solution (t-butyl hydroperoxide) was run at 12.4 g per hour and a 4.92% Bruggolite solution at 32.8 g per hour. The two doses ran for a period of 2 hours. After the end of TBHP and Brüggolitdosierung the approach ran for 1 hour at 6O ⁰ C after. After the end of the polymerization, the dispersion was treated with water vapor ("stripped") for residual monomer minimization and subsequently preserved with hydor W. A homogeneous and stable dispersion was obtained.

Dispersion Analyzes:

Solids content: 45.8%; pH: 3.9; Brookfield viscosity 20 (spindle 7): 83,000 mPas; MFT: 6 ⁰ C; Glass transition temperature Tg: 20.2 ⁰ C; average particle size: 557.7 nm (Nanosizer) Coulter: Dn = 0.268 μm; Dv = 0.810 μm; Surface = 10.8 m ² / g-

Example 3: 116.74 g of W 25/140 (polyvinyl alcohol, 10% strength aqueous solution), 29.18 g of Genapol PF 80 (20% strength aqueous solution), 2.22 g of Mersolat K30 (30% strength aqueous solution) were mixed in a 2 liter stirring apparatus with anchor stirrer ) submitted. For this purpose, a previously prepared solution of 23.35 g of a silicone organocopolymer having a composition of 70.0% by weight of styrene and 30.0% by weight of silicone (prepared in Example b)) in 93.4 g of vinyl acetate was added. This original was stirred at 300 rpm. With 10% formic acid was adjusted to pH = 5-5.5. Then wur- de boiler at 60 ⁰ C heated. Once the reactor was in thermal equilibrium, an 8.7% TBHP solution (t-butyl hydroperoxide) was run at 5.72 g per hour and a 4.92% Bruggolite solution at 15.15 g per hour. Twenty minutes later, a mixture (in the form of a pre-emulsion) of 150.0 g of water, 467.0 g of W 25/140 (polyvinyl alcohol, 10% aqueous solution), 116.74 g of Genapol PF 80 (20% aqueous solution ), 8.87 g of Mersolat K30 (30% strength aqueous solution) and a previously prepared solution of 93.4 g of a silicone organocopolymer having the composition 70.0% by weight of styrene and 30.0% by weight of silicone (prepared in Example b)) in 373.6 g of vinyl acetate at a rate of 353.3 g per hour (pre-emulsion dosage). The reaction was stirred at 300 rpm. The total dosing time for the pre-emulsion dosing was 3 hours. At the end of pre-emulsion dosing, the TBHP and Brüggolit dosing was still

1 hour continued. The dispersion was then treated with water vapor ("stripped") for residual monomer minimization and preserved with Hydorol W. A homogeneous and stable dispersion was obtained.

Solids content: 43.4%; pH value: 4.3; Brookfield viscosity

20 (spindle 7): 7900 mPas; Glass transition temperatures Tg: TgI = 25.1 ° C, Tg2 = 66.3 ° C (very small); average particle size: 438.8 nm (Nanosizer); Coulter: Dn = 0.339 μm; Dv = 0.521 μm; Surface = 16.3 m ² / g

Example 4:

97.95 g W 25/140 (polyvinyl alcohol, 10% strength aqueous solution), 24.49 g Genapol PF 80 (20% strength aqueous solution), 1.86 g merolate K30 (30% strength by weight) were used in a 2 liter stirring apparatus with anchor stirrer aqueous solution). For this purpose, a previously prepared solution of 19.59 g of a silicone organopolymers having the composition 70.0% by weight of styrene and 30.0% by weight of silicone (prepared in Example b)) in 78.36 g of methyl methacrylate was added. The original was stirred at 200 rpm. With 10% formic acid was adjusted to pH = 5-5.5. Subsequently, the kettle was heated to 60 ⁰ C. Once the reactor was in thermal equilibrium, a 8.7% TBHP solution (tert. Butyl hydroperoxide) was run at 4.8 g per hour and a 4.92% Bruggolite solution at 12.7 g per hour. Twenty minutes later, a mixture (in the form of a pre-emulsion) of 225.29 g of water, 391.81 g of W 25/140 (polyvinyl alcohol, 10% aqueous solution), 97.95 g of Genapol PF 80 (20% aqueous solution ), 7.44 g of Mersolat K30 (30% strength aqueous solution) and a previously prepared solution of 78.36 g of a silicone organocopolymer of the composition 70.0% by weight of styrene and 30.0% by weight of silicone (prepared in Example b)) in 313.45 g of methyl methacrylate at a rate of 370 g per hour to dose (pre-emulsion dosage). The reaction was stirred at 200 rpm. The total dosing time for the pre-emulsion dosing was 3 hours. After the end of the pre-emulsion dosage, the TBHP and Brüggolitdosierung continued for 1 hour. The dispersion was then treated with water vapor ("stripped") for residual monomer minimization and preserved with Hydorol W. Before dispersion, the dispersion was diluted with 200 g of water to give a homogeneous and stable dispersion. Dispersion analyzes: Solids content: 33.0%; pH: 5.1; Brookfield viscosity 20 (spindle 5): 12240 mPas; Glass transition temperatures Tg: TgI = 68.3 ° C (small), Tg2 = 104.1 ⁰ C (large); average particle size: 637.2 nm (Nanosizer); Coulter: Dn = 0.115 μm; Dv = 26.25 μm; Surface = 9.06 m ² / g.

Example 5:

91.55 g of water, 91.55 g of W 25/140 (polyvinyl alcohol, 10% strength aqueous solution), 22.89 g of Genapol PF 80 (20% strength aqueous solution) were used in a 2 liter stirring apparatus with anchor stirrer.

1.74 g Mersolat K30 (30% aqueous solution) submitted. For this purpose, a previously prepared solution of 18.31 g of a SiIi konorganocopolymeren the composition 67.0 wt .-% vinyl acetate and 33.0 wt .-% silicone (prepared in Example a)) in 73.24 g of methyl methacrylate. With 10% formic acid was adjusted to pH = 5-5.5. The original was stirred at 200 rpm. The kettle was then heated to 6O ⁰ C aufge¬. Once the reactor was in thermal equilibrium, an 8.7% TBHP solution (tertiary butyl hydroperoxide) was run at 4.5 g per hour and a 4.92% Bruggolite solution at 11.9 g per hour. Twenty minutes later wur¬ de started, a mixture (in the form of a pre-emulsion) of 210.56 g of water, 366.19 g W 25/140 (polyvinyl alcohol, 10% aqueous solution), 91.55 g of Genapol PF 80 (20% aqueous Lö solution), 6.96 g of Mersolat K30 (30% strength aqueous solution) and a previously prepared solution of 73.24 g of a silicone organocopolymer having the composition 67.0% by weight of vinyl acetate and 33.0% by weight of silicone (prepared in Example a)) in 292.95 g of methyl methacrylate at a rate of 346.7 g per hour to meter (pre-emulsion dosage). The reaction was stirred at 200 rpm. The total dosing time for pre-emulsion dosing was 3 hours. After the end of the pre-emulsion dosing the TBHP and Brüggolitdosierung was continued for 1 hour. The dispersion was then treated with water vapor ("stripped") for residual monomer minimization and preserved with Hydorol W. The dispersion was pre-stripped Bottling still diluted with 200 g of water. A homogonal and stable dispersion was obtained. Dispersion Analyzes:

Solids content: 32.2%; pH: 4.9; Brookfield viscosity 20 (spindle 4): 5650 mPas; Glass transition temperature Tg: 81.3 ⁰ C (broad); average particle size: 1295.1 nm (Nanosizer); Coulter: Dn = 0.104 μm; Dv = 32.41 μm; Surface = 5.39 m ² / g.

EXAMPLE 6 91.55 g of water, 91.55 g of W 25/140 (polyvinyl alcohol, 10% strength aqueous solution), 22.89 g of Genapol PF 80 (20% strength aqueous solution), 1.74 g of Mersolat K30 were used in a 2 liter stirring apparatus with anchor stirrer (30% aqueous solution) submitted. To this was added a previously prepared solution of 18.31 g of a SiIi konorganocopolymeren the composition 70.0 wt .-% of styrene and 30 wt .-% silicone (prepared in Example b)) in 36.62 g of methyl methacrylate and 36.62 g of butyl acrylate. The original was stirred at 200 rpm. With 10% formic acid was adjusted to pH = 5-5.5. Subsequently, the kettle was heated to 60 ⁰ C. Once the reactor was in thermal equilibrium, an 8.7% TBHP solution (t-butyl hydroperoxide) was run at 4.5 g per hour and a 4.92% Bruggolite solution at 11.88 g per hour. Twenty minutes later, a mixture (in the form of a preemulsion) of 210.56 g of water, 366.19 g of W 25/140 (polyvinyl alcohol, 10% aqueous solution), 91.55 g of Genapol PF 80 (20% aqueous solution ), 6.96 g of Mersolat K30 (30% strength aqueous solution) and a previously prepared solution of 73.24 g of a silicone organocopolymer having the composition 70.0% by weight of styrene and 30% by weight of silicone (prepared in Example b)) in

146.48 g of methyl methacrylate and 146.48 g of butyl acrylate at a rate of 346.7 g per hour to meter (Voremulsionsdosie¬ tion). The reaction was stirred at 200 rpm. The total metering time for the pre-emulsion dosage was 3 hours. After the end of the pre-emulsion dosage, the TBHP and Brüggolitdosierung continued for 1 hour. The dispersion was subsequently used for residual monomer minimization Treated steam ("stripped") and preserved with Hydorol W. A homogeneous and stable dispersion was obtained.

Solids content: 37.54%; pH: 4.9; Brookfield viscosity 20 (spindle 4): 12300 mPas; Glass transition temperature Tg:

10.4 ⁰ C; average particle size: 841.4 nm (Nanosizer); Coulter: Dn = 0.257 μm; Dv = 1643 μm; Surface area = 11.8 m ² / g

Comparative Example 7: 1.29 kg of water, 2.67 kg of W 25/140 (polyvinyl alcohol, 10% strength aqueous solution), 101.55 g of Genapol X 050 (100% strength), 115.66 g of Texapon K12 (10% strength by weight) were placed in a 20 liter pressure autoclave. aqueous solution), 4.19 g sodium acetate, 641.34 g vinyl acetate and 427.56 g of an α, ω-divinyl-functionalized polydimethylsiloxane having 133 SiOMe ₂ repeating units (silicone macromer Wacker VIPO 300 °). With 10% formic acid was adjusted to pH = 5. Further, 10 ml of Trilon B (EDTA; 2% aqueous solution) and 31 ml of iron ammonium sulfate (1% solution) were added. The kettle was heated to 7O ⁰ C and 8 bar of nitrogen were pressed. Once the reactor was in thermal equilibrium, a 5.8% ammonium persulfate solution (APS solution) was run at 84 g per hour and a 2.68% sodium sulfite solution at 176 g per hour. 25 minutes later, a mixture of 2.57 kg of vinyl acetate and 1.71 kg of VIPO 300 was metered in at a rate of 2140 g per hour (monomer feed). At the same time, an emulsifier metering with a metering capacity of 625 g per hour was run in. The emulsifier dosage contained 385.32 g of water, 406.18 g of Genapol X 050, and 462.62 g of Texapon K12 (10% aqueous solution). The total dosing time for the monomer metering and the emulsifier doses amounted to 2 hours. 20 minutes after the start of the reaction, the APS dosage was increased to 126 g per hour, the Na sulfite dosage to 262 g per hour. After the end of the monomer metering or emulsifier metering, the APS and Na

SuIfitdosierung continued for 1 hour. After expansion, the dispersion was subjected to residual monomer minimization with water Steamed ("stripped") and then preserved with Hydorol W. Dispersion analysis:

Solids content: 50.5%, pH value: 5.3; Brookfield viscosity 20 (spindle 4): 1040 mPas; MFT: ⁰ C; Glass transition temperature

Tg: 18.4 ° C; average particle size: 452.5 nm (Nanosizer) Coulter: Dn = 0.124 μm; Dv = 1,697 μm; Surface area = 14.7 m ² / g Soxhlet extraction: residue completely evaporated EIu at 1.94 g = 38.8% (extracted from 5 g of a dried dispersion film with cyclohexane).

Comparative Example 7 shows that with conventional emulsion polymerization-in this case vinyl acetate with silicone macromer-an insufficient attachment of the silicone macromer to the organic monomer takes place, which is also described in the literature. During the extraction, 38.8% of the constituents could be washed out of a dried dispersion film. 1H NMR spectroscopy showed that most of the extractable components were free silicone macromers.

With the method according to the invention, this problem and all the disadvantages resulting therefrom are eliminated. It is ensured with this invention that the organic monomer is completely bonded to the silicone macromer, i. there is no free silicone left. This is achieved by preparing the silicone organocopolymer separately beforehand by polymerization.

Claims

claims:

1. A process for the preparation of silicone-modified polymers of ethylenically unsaturated monomers in the form of their aqueous polymer dispersions or water-redispersible polymer powder, characterized in that

C) this solution is emulsified in water and free-radically polymerized, and optionally

D) the resulting aqueous dispersion of the silicone-modified polymers is dried.

2. The method according to claim 1, characterized in that in step A) and B) are used as ethylenically unsaturated monomers one or more monomers from the Grup¬ pe comprising vinyl esters of unbranched or branched alkylcarboxylic acids having 1 to 15 carbon atoms, methacrylic acid - esters and acrylic esters of alcohols having 1 to 15 carbon atoms, vinyl aromatics, olefins, dienes and vinyl halides.

3. The method of claim 1 or 2, characterized in that in step A) are used as Silikonmakromere those from the group comprising linear, branched, cyclic and three-dimensionally crosslinked polysiloxanes having at least 10 siloxane repeating units and at least one radically polymerizable functional group.

4. The method according to claim 1 to 3, characterized in that in step A), the preparation of the prepolymer is carried out by means of radical solution polymerization.

5. The method according to claim 1 to 3, characterized in that in step A) the preparation of the prepolymer is carried out by means of free-radical suspension polymerization.

6. The method according to claim 1 to 5, characterized in that in step C) radically polymerized after the Emulsionspolymerisationsver-.

7. Silicone-modified polymers of ethylenically unsaturated monomers in the form of their aqueous polymer dispersions or water-redispersible polymer powders, obtainable by a process as claimed in claims 1 to 6.

8. Use of the silicone-modified polymers according to claim 7 in adhesives, in coating compositions, as a binder for the consolidation of fibers or other particulate materials, in the textile sector, as modifiz¬ rungsmittel and as a hydrophobing agent.

9. Use of the silicone-modified polymers according to claim 7 as a binder in the construction industry for An¬ strich-, adhesive and coating agent.

10. Use of the silicone-modified polymers according to claim 7 as an additive in paints and in cosmetic formulations.

11. Use of the silicone-modified polymers according to claim 7 as a binder for toner for the preparation of silicone-modified toner particles.