Patent ID: 7381760

Claim:
A pigment dispersion, comprising: a condensate of or a salt between polyallylamine and a polyester having a free carboxylic acid group; a pigment derivative represented by the following formula (1); a pigment; and an organic solvent: (P−X) − [N(R 1 , R 2 , R 3 , R 4 )] + formula (1) wherein P represents an organic dyestuff residue selected from the group consisting of azo, benzimidazolone, phthalocyanine, quinacridone, anthraquinone, dioxazine, diketopyrrolopyrrole, quinophthalone, isoindolinone, isoindoline, perylene, perynone, flavanthrone, pyranthrone and anthrapyrimidine; X represents a sulfonic acid group or a carboxylic acid group; R 1 represents an alkyl group having 5 to 20 carbon atoms; and R 2 , R 3 and R 4 each is a hydrogen atom.