Thickening agent compositions based on vinyl alcohol copolymers and cellulose ethers

摘要

A thickening agent comprises an at least partially saponified vinyl alcohol polymer having a degree of hydrolysis of 75-100 mol.% and a mol. wt. of greater than 100,000 and a cellulose ether. A thickening agent (I) comprises: (A) an at least partially saponified vinyl alcohol polymer having a degree of hydrolysis of 75-100 mol.% and a mol. wt. of greater than 100,000 prepared by (A1) saponification of vinyl acetate mixed polymers containing comonomer units derived from 1-alkylvinylesters of 1-5C alkyl groups of 1-5C carboxylic acids, alkylester, vinylesters of 5-12C alpha-branched carboxylic acids, acrylic acid or methacrylic acid esters of 1-18C alcohols or (A2) acetalization of the saponified vinyl acetate mixed polymers or saponified vinyl acetate homopolymers with aliphatic or aromatic, optionally substituted aldehydes; and (B) a cellulose ether comprising alkylcellulose ether, hydroxyalkyl cellulose ether, carboxyalkylcellulose ether, hydroxyalkylpolyoxyalkyl cellulose ether with 1-10C alkyl groups as well as cellulose mixed ethers with at least 2 substituents comprising alkyl, hydroxyalkyl, carboxylalkyl or hydroxyalkylpolyoxyalkyl with 1-10C alkyl groups. An Independent claim is included for a process for the production of the thickening agent (I) by mixing the polyvinylalcohol component (A) and the cellulose ether component (B) in a separate mixing process.