Patent ID: 7300545

Claim:
A water-soluble polymer dispersion in which a water-soluble polymer having at least one type of ionicity selected from among cationicity and amphotericity and occurring in the form of fine particles with a particle size of not greater than 100 μm and a polyalkylenimine in the sulfate salt form coexist, wherein the polymer is produced by dispersion polymerization of a monomer (or monomer mixture) comprising 5 to 100 mole percent of a monomer represented by the general formula (1) and/or (2) given below, 0 to 50 mole percent of a monomer represented by the general formula (3) given below and 0 to 95 mole percent of a water-soluble nonionic monomer with stirring in the presence of said polyalkylenimine in the sulfate salt form; wherein the general formula (1), R 1 is a hydrogen atom or a methyl group, R 2 and R 3 may be the same or different and each is an alkyl or an alkoxy group containing 1 to 3 carbon atoms or a benzyl group, R 4 is a hydrogen atom, an alkyl or alkoxy group containing 1 to 3 carbon atoms or a benzyl group. A represents an oxygen atom or NH, B represents an alkylene or an alkoxylene group containing 2 to 4 carbon atoms, and X 1 represents a sulfate anion; wherein the general formula (2), R 5 represents a hydrogen atom or a methyl group, R 6 and R 7 each represents an alkyl or an alkoxy group containing 1 to 3 carbon atoms or a benzyl group, and X 2 represents a sulfate anion; wherein the general formula (3), R 8 represents a hydrogen atom, a methyl group or a carboxymethyl group, Q represents SO 3 , C 6 H 4 SO 3 , CONHC(CH 3 ) 2 CH 2 SO 3 , C 6 H 4 COO or COO, R 9 represents a hydrogen atom or COOY 2 , and Y 1 or Y 2 represents a hydrogen atom or a cation.