Patent ID: 6552141
Filing Date: 2003-04-22
Classification: C08F

Abstract:
A process for producing a water-soluble or water-swellable polymer or copolymer comprising, providing an acid monomer or monomers alone, or with a comonomer or comonomers; mixing said monomer or monomers with a nitrogen salt compound or compounds selected from the group consisting of amine salts of hydrofluoric acid, hydrochloric acid, hydrobromic acid, hydriodic acid, sulfuric acid, sulfurous acid, sulfoxylic acid, thiophosphoric acid, phosphorous acid, nitric acid and nitrous acid, amine salts of organic acids, hydroxylamine salts, alkanolamine salts, alkylamine salts and mixtures thereof;free-radical polymerizing said monomer or monomers alone, or with a comonomer or comonomers to form said water-soluble or water-swellable polymer or copolymer; and subsequently heating said water-soluble or water-swellable polymer or copolymer at a temperature of from 120 to 240Â° C.