HIGH TEMPERATURE VISCOSITY STABLE THICKENER

摘要

A hydrophobe-containing alkali soluble or swellable copolymer thickener comprising an emulsion polymerization product of (A) an ethylenically unsaturated copolymerizable surfactant monomer having a cloud point of from about 65.degree.C to about 95.degree.C, wherein the surfactant monomer has the formula M(EO)x(PO)y(BO)zOR1 wherein M is a residue selected from the group consisting of an ethylenically unsaturated carboxylic acid, ethylenically unsaturated dicarboxylic acid, and a copolymerizable isocyanate; EO is an ethylene oxide unit; PO is a propylene oxide unit; BO is a butylene oxide unit; x is from 10 to 45; y is from 0 to 35; z is from 0 to 35; provided that x + y + z is from 20 to 45; and R1 is selected from the group consisting of alkyl, alkylene, cycloalkyl, cycloalkylene, and arylalkyl group wherein the alkyl group has 1 to 30 carbon atoms; (B) an .alpha., .beta.-ethylenically unsaturated monocarboxylic acid monomer; and (C) a nonionic .alpha., .beta.-ethylenically unsaturated monomer. The copolymer provides aqueous compositions with constant or increased viscosity at temperatures approaching 120.degree.C.