Patent ID: 7288592

Claim:
A solid, transparent organic silicone copolymer or hydrolysis product thereof, prepared by solution polymerizing monomers comprising: a1) ≧50% by weight of at least one vinyl ester of optionally branched alkyl carboxylic acids having from 1 to 15 carbon atoms, and a2) from 0 to 20% by weight of one or more monounsaturated olefins and/or dienes, and b) from 1 to 50% by weight of one or more silicones of the formula R 1 a R 3-a SiO(SiR 2 O) n SiR 3-a R 1 a , in which each R is an identical or different monovalent, optionally substituted C 1-18 alkyl or C 1-18 alkoxy radical, R 1 is a polymerizable group, a is 0 or 1, and n is 10 to 1000, from 85 to 100% by weight of the silicones b) containing one or two polymerizable groups, with silicones b) having only one polymerizable group (b1) used only in admixture with silicones b) having two polymerizable groups (b2) in a weight ratio b1):b2) ≦1:1, and c) from 0 to 10% by weight of one or more ethylenically unsaturated hydrolyzable silicon compound monomers or mercaptosilane monomers different from silicones b), the amounts in % by weight for components a) to c) based on the overall weight of the monomers used and adding up to 100% by weight, in a nonaqueous solvent mixture in the presence of at least one free-radical initiator, wherein the nonaqueous solvent mixture comprises a mixture of at least two nonaqueous solvents of which at least one has a transfer constant C s to vinyl acetate of greater than 20×10 −4 at 70° C., wherein the silicone copolymer has a complex melt viscosity of from 5 to 30,000 mPa·s and a phase angle δ of 45°, measured at a temperature within the range of 100° C. to 140° C., and optionally hydrolyzing the product thus obtained.