Patent ID: 7008994

Claim:
A water-based pigment dispersion comprising: a pigment and a cross-linked thermoplastic resin containing carboxylic group, wherein said pigment is dispersed with a water soluble or self-emulsifying thermoplastic resin containing carboxylic group and, after said pigment is dispersed, said water soluble or self-emulsifying thermoplastic resin is cross-linked with a cross-linking agent to form said cross-linked thermoplastic resin containing carboxylic group under the condition that the dispersion obtained after the completion of the cross-linking has a pH of 6.0 to 7.8, in which the ratio of said pigment to said water soluble or self-emulsifying thermoplastic resin (pigment/thermoplastic resin (weight ratio of effective solid matter)) is 10/10 to 10/1, and the ratio of said cross-linking agent to said water soluble or self-emulsifying thermoplastic resin (cross-linking agent/thermoplastic resin (weight ratio of effective solid matter)) is 1/100 to 50/100.