| abstract |
The invention relates to silane-modified polyvinyl acetals, obtainable by copolymerization of a) one or more monomers from the group comprising vinyl esters of unbranched or branched alkyl carboxylic acids having 1 to 15 C atoms, and optionally one or more monomers from the group comprising ( Meth) acrylic acid esters of alcohols with 1 to 15 C atoms, olefins, dienes, vinyl aromatics and vinyl halides with b) 0.02 to 20.0% by weight of one or more hydrolyzable silane compounds from the group comprising ethylenically unsaturated, hydrolyzable silicon compounds and hydrolyzable mercaptosilanes, subsequent saponification of the vinyl ester copolymers to a content of> = 50 mol% of vinyl alcohol units and final acetalization of the vinyl alcohol units with one or more aldehydes from the group comprising aliphatic and aromatic aldehydes with 1 to 15 carbon atoms, DOLLAR A characterized in that DOLLAR A the comonomers a) and the silane comonomers b) are introduced as a mixture in an amount of 5 to 50% by weight, based on the total weight of the comonomers a) and b), and the rest of the mixture is metered in during the polymerization, so that the ratio the comonomers a) and the silane comonomers b) remain approximately constant at all times during the polymerization and a homogeneous polymer results. |