Patent ID: 7381761

Claim:
A process for preparing silicone-modified polymers in the form of an aqueous polymer dispersion or polymer powder prepared therefrom, by means of free-radical polymerization of ethylenically unsaturated monomers in an aqueous medium, comprising polymerizing a polymerizable mixture containing at least one monomer selected from the group consisting of vinyl esters of unbranched or branched C 1-15 alkylcarboxylic acids, methacrylic esters and acrylic esters of C 1-15 alcohols, vinyl aromatics, monoolefins, dienes and vinyl halides, to form an addition polymer, and optionally, further auxiliary monomers to form a dispersed phase, and wherein at least one silicone-containing vinyl alcohol copolymer prepared from monomers comprising a) from 0 to 60% by weight of units of one or more vinyl esters of unbranched or branched C 1-15 alkylcarboxylic acids, b) from 20 to 99.5% by weight of vinyl alcohol units, c) from 0.5 to 70% by weight of units of one or more silicones having the general formula R 1 a R 3-a SiO(SiR 2 O) n SiR 3-a R 1 a , where the radicals R are identical or different and are each a monovalent, substituted or unsubstituted alkyl or alkoxy radical each having from 1 to 18 carbon atoms, R 1 is a polymerizable group, a is 0 or 1, and n is from 10 to 1000, where at least one silicone contains at least one radical R 1 the percentages by weight add up to 100% by weight, is present during polymerization, is present during polymerization and added following polymerization, or is added following polymerization and the resulting mixture is spray dried to form a polymer powder.