Patent ID: 6949138

Claim:
A pigment dispersion liquid comprising pigment particles and Pigment derivatives, which are derived from the pigment, have the same nucleus as the pigment and polar group, dispersed in a dispersion medium, wherein the pigment derivatives are anionic; wherein the difference (D 90 −D 10 ) between D 10 and D 10 being not more than 25 rim, and wherein D 90 and D 10 represent the primary particle size that the pigment particles having a primary particle size up to and including D 90 account for 90% by number of the total pigment particles, and the particle size that the pigment particles having a primary particle size up to and including D 10 account for 10% by number of the total pigment particles, respectively, in the integral of the primary particle size distribution function dG=f(D)×dD of the pigment particles in which G is a particle number (%) and D is a primary particle size (nm).