Wacker Polymer Systems Gmbh & Co. Kg

Kuraray Europe Gmbh

Wacker Polmer Systems Gmbh & Co. Kg

Bernhard Glaser

Kurt Stark

Karl-Heinz Eichel

Abdulmajid Hashemzadeh

Peter Tschirner

Thomas Kornek

Christian Hoegl

Werner Bauer

Cationic polyvinyl acetals are prepared by copolymerizing one or more cationic N-alkyldiallylammonium salt monomers with one or more vinyl esters of branched or unbranched carboxylic acids having 1 to 15 carbon atoms, hydrolyzing the resulting copolymers to copolymers containing &#x2267;50 mol % vinyl alcohol units, and acetalizating the vinyl alcohol units with one or more aliphatic aldehydes having 1 to 15 carbon atoms, their acetals, and/or hemiacetals, wherein the copolymerization takes place in a mixture of water and monovalent aliphatic alcohol having a water content of 2% to 35% by weight.

Process for preparing cationic polyvinyl acetals

Low molecular weight polyvinyl acetals have a solution viscosity of from 2 to 12 mPas and a degree of polymerization Pless than 200, and are obtained by hydrolyzing a vinyl ester polymer having a solution viscosity of from 1.0 to 1.6 mPas until the content of vinyl alcohol units is &#x2267;50 mol %, to produce a polyvinyl alcohol whose solution viscosity is from 1.0 to 2.0 mPas, and then acetalizing the resultant polyvinyl alcohol. The products may be used as binders and films of increased adhesion to substrates.

Polyvinyl acetals with improved adhesion

Silane-modified polyvinyl acetals are obtained by copolymerizing a) vinyl esters of C alkylcarboxylic acids having from 1 to 15 carbon atoms, and optionally (meth)acrylates C of alcohols, olefins, dienes, vinylaromatics, or vinyl halides, with b) from 0.02 to 20.0 % by weight of an ethylenically unsaturated, hydrolyzable silicon compounds or hydrolyzable mercaptosilanes; hydrolyzing the resulting vinyl ester copolymers to 50 mol % or more of vinyl alcohol units; and acetalizing vinyl alcohol units with a C aliphatic or aromatic aldehydes, wherein from 5 to 50 % by weight of a mixture of comonomers a) and silane comonomers b), based on the total weight of comonomers a) and b), is used as an initial charge, and the remainder is metered in during polymerization, such that the ratio between the comonomers a) and silane comonomers b) remains constant throughout the polymerization, resulting in a homogeneous polymer.

Silane-modified polyvinyl acetals

The invention relates to silane-modified polyvinyl acetals obtained by acetalizing partially hydrolyzed or fully hydrolyzed vinyl ester polymers having at least 50 mol % of vinyl alcohol units with one or more aldehydes, optionally in the form of their hemiacetals or their acetals, where at least one aldehyde contains hydrolyzable silane groups.

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Woerth, Germany

Bernhard Glaser