Patent ID: 7601779

Claim:
A polymer compound comprising a unit composed of a sulfur-containing compound (A) having at least two active hydrogen groups, a unit composed of a compound (B) having at least two isocyanate groups and a unit composed of an amine compound (C) having at least two active hydrogen groups, said polymer compound having an average particle size of from 5 nm to 200 as determined by a cumulant method and having an amino group in its structure, at least a part of the amino group being cationized, wherein the sulfur-containing compound (A) is represented by a general formula selected from the group consisting of the following general formulas (1) to (6), wherein n is 1 or 2, and R 1 is a methylene, ethylene or propylene group, wherein n is 1 or 2, and R 2 and R 3 are, independent of each other, hydrogen, a hydroxyl group or an alkyl group and may be the same or different from each other, wherein n is 0 or 1, wherein n is 1 or 2, R 4 is sulfur or oxygen, and R 5 is sulfur or —SO 2 , with the proviso that R 4 and R 5 are different from each other, wherein R 6 and R 7 are, independently of each other, hydrogen or an alkyl group and may be the same or different from each other, and wherein R 8 is a hydroxyl group or an alkyl group.