Patent ID: 8084092

Claim:
A water-insoluble colorant dispersion prepared by a production method including a step of codissolving a water-insoluble colorant and a polymer compound having one or more acid groups selected from carboxylic acid group, sulfonic acid group and phosphoric acid group as hydrophilic group in an organic solvent in the presence of a phase-transfer base represented by the following Formula (I) or (II), and a step of mixing the solution obtained in the above step with an aqueous medium, to thereby obtain the water-insoluble colorant dispersion containing water-insoluble colorant fine particles having an average particle size of from 5 nm to 50 nm, a polymer compound having one or more acid groups selected from the group consisting of carboxylic acid group, sulfonic acid group and phosphoric acid group as hydrophilic group, an aqueous medium, and a phase-transfer base represented by the following Formula (I) or (II): wherein R 1 , R 2 , R 3 , R 4 and R 5 each independently represents a methyl group, an ethyl group, or a propyl group, n represents an integer of 1 to 4, wherein an acid value of the polymer compound having one or more acid groups is 100 mg-KOH/g to 300 mg-KOH/g.