Patent ID: 7919545

Claim:
A pigment dispersion comprising at least a pigment at a concentration of from 2 to 50 mass % in the pigment dispersion, and a polymer having from 2 to 50 mass % of repeating units represented by the following formula (1) and from 2 to 40 mass % of repeating units represented by the following formula (2) and having a weight average molecular weight of from 10,000 to 500,000: wherein, R 1 represents a hydrogen atom or a methyl group; I represents —COO—, —CONR 3 —, —OCO—, or a phenylene group; R 3 represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group; Y represents a single bond or a bivalent linking group; R 2 represents an alkyl group having 1 to 4 carbon atoms; and R 2 and Y may be bonded to each other to form a ring structure: wherein, R 4 represents a hydrogen atom or a methyl group; J represents —CO—, —COO—, —CONR 5 —, —OCO—, or a phenylene group; R 5 represents a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group; W represents a single bond or a bivalent linking group; and P represents a heterocyclic residue having a heterocyclic ring contained in an organic pigment.