Patent ID: 6784262
Filing Date: 2004-08-31
Classification: C08F,C08L,Y10S

Abstract:
A process for chemically-modifying the surface of a polymer particle, comprising:(a) providing an aqueous emulsion comprising (i) a multistage emulsion polymer comprising a core stage polymer and a shell stage polymer, wherein said core stage polymer comprises, as polymerized units, from 5% to 100% by weight, based on the weight of said core stage polymer, of hydrophilic monoethylenically unsaturated monomer, and from 0% to 95% by weight, based on the weight of said core stage polymer, of at least one nonionic monoethylenically unsaturated monomer; and wherein said shell stage polymer comprises, as polymerized units, at least 50% by weight of nonionic monoethylenically unsaturated monomer; (ii) a nonionic monomer at a level of at least 0.5% by weight based on the weight of said multistage emulsion polymer; and (iii) at least one surface-modifying chemical capable of chemically bonding with said nonionic monomer; under conditions wherein there is no substantial polymerization of said nonionic monomer; and (b) reducing the level of said nonionic monomer by at least 50%.