Patent ID: 6242531
Filing Date: 2001-06-05
Classification: C08F,C08L,C09D

Abstract:
An aqueous miniemulsion acrylic copolymer thickener for thickening latex paints, the thickener copolymer comprising aqueous copolymerized ethylenically unsaturated monomers on a weight basis:between 10% and 90% carboxyl functional monomer;between 1% and 50% long alkyl chain ester of acryl or methacrylate where the alkyl chain contains from 11 to 22 carbon atoms;between 0 % and 90 % short chain acrylate or methacrylate selected from methyl acrylate, ethyl acrylate, methyl methacrylate, and ethyl methacrylate;with the balance being other ethylenically unsaturated monomers and the total of ethylenically unsaturated monomers copolymerized is 100%;where the thickener copolymer is produced by (a) mixing said ethylenically unsaturated monomers in water and surfactant to form an aqueous macroemulsion of liquid monomers, (b) micronizing the aqueous macroemulsion to form a uniform aqueous miniemulsion having an emulsion droplet size less than 5 microns, (c) copolymerizing the ethylenically unsaturated monomers in the absence of solvent to produce a carboxyl functional miniemulsion high molecular weight copolymer having a particle size less than 5 microns, and (d) partially neutralizing the carboxyl functional copolymer with amine to form a thickener copolymer.