Thickening agents based on vinyl alcohol copolymers

摘要

Thickener comprising completely or partially saponified vinyl alcohol copolymer. Thickener (I) is based on completely or partially saponified vinyl alcohol copolymers of molecular weight (Mw) more than 100000, in aqueous solution or powder form, obtained by saponifying vinyl acetate copolymers (II) in which the comonomers are one or more of 1-(1-5C alkyl)-vinyl esters of 1-5C carboxylic acids, allyl esters, vinyl esters of alpha -branched 5-12C carboxylic acids and/or 1-18C alcohol (meth)acrylate esters. An Independent claim is included for the preparation of (I), involving preparation of the vinyl acetate copolymer (II) by radical initiated bulk, solution, suspension or emulsion copolymerization at 5-90 degreesC followed by saponification (hydrolysis) of (II).