Patent ID: 7732527
Filing Date: 2010-06-08
Classification: B41M,C08F,C08K,C08L,D21H

Abstract:
1. A water-soluble polymer reduced in molecular weight as obtained by subjecting either an aqueous solution admixed with an aqueous solution of an oxidizing agent and containing an amount within the range of 10-60% by mass of a water-soluble polymer and having a viscosity of not lower than 3000 mPa·s determined using a rotation viscometer or a granular composition admixed or impregnated with an aqueous solution of an oxidizing agent and containing an amount within the range of 10-60% by mass of a water-soluble polymer to oxidation reaction to thereby reduce the degree of polymerization of the water-soluble polymer, characterized in that the oxidation reaction is carried out without stirring and the water-soluble polymer is a cationic water-soluble polymer comprising at least one structural unit selected from among the cationic structural units represented by the general formulas (1) to (4) given below: wherein R 1 is a hydrogen atom or a methyl group, R 2 and R 3 each is an alkyl or alkoxyl group containing 1-3 carbon atoms, R 4 is a hydrogen atom, an alkyl or alkoxyl group containing 1-3 carbon atoms or a benzyl group, and R 1 -R 4 may be the same or different, A represents an oxygen atom or NH, B represents an alkylene or alkoxylene group containing 2-4 carbon atoms, and X 1 represents an anion; wherein R 5 and R 6 each represents a hydrogen atom or a methyl group, R 7 and R 8 each represents an alkyl or alkoxyl group containing 1-3 carbon atoms or a benzyl group, and X 2 represents an anion; wherein R 9 and R 10 each represents a hydrogen atom or a methyl group and X 3 represents an anion; and wherein R 11 represents a hydrogen atom or a methyl group and X 4 represents an anion.