Patent ID: 6994745

Claim:
A pigment dispersing resin which is a copolymer of: (A) polymerizable unsaturated monomer containing at least one kind of ionic functional group selected from the group consisting of tertiary amino group, quaternary ammonium salt and sulfonic acid group; (B) nonionic polymerizable unsaturated monomer having polyoxyethylene chain; (C) ultraviolet-stabilizing polymerizable unsaturated monomer which is selected from the group consisting of 4-(meth)acryloyloxy-1,2,2,6,6-pentamethylpiperidine, 4-(meth)acryloyloxy-2,2,6,6-tetramethylpiperidine, 4-cyano-4-(meth)acryloylamino-2,2,6,6-tetramethylpiperidine, 1-(meth)acryloyl-4-(meth)acryloylamino-2,2,6,6-tetramethylpiperidine, 1-(meth)acryloyl-4-cyano-4-(meth)acryloylamino-2,2,6,6-tetramethylpiperidine, 4-crotonoyloxy-2,2,6,6-tetramethylpiperidine, 4-crotonoylamino-2,2,6,6-tetramethylpiperidine and 1-crotonoyl-4-crotonoyloxy-2,2,6,6-tetramethylpiperidine; and (D) other ethylenically unsaturated monomer, said copolymer being a copolymerization product of 0.5 to 30% by weight of ionic functional group-containing polymerizable unsaturated monomer (A), 5 to 40% by weight of nonionic polymerizable unsaturated monomer (B), 0.1 to 5% by weight of ultraviolet-stabilizing polymerizable unsaturated monomer (C) and 25 to 94.4% by weight of other ethylenically unsaturated monomer (D) on the basis of the total weight of monomers (A), (B), (C) and (D).