| abstract |
[PROBLEMS] To provide excellent print quality on various recording media, particularly excellent glossiness and fixability on glossy paper, and ink reliability such as ejection stability, storage stability, and clogging recovery. The present invention also provides an ink composition that is excellent. An ink composition comprising at least a surface-treated pigment that can be dispersed and / or dissolved in an aqueous medium without a dispersant, a water-insoluble vinyl polymer, and water, wherein the surface-treated pigment comprises: A hydrophilic polymer is bonded to the surface of a solid solution pigment composed of two or more pigments, and the water-insoluble vinyl polymer comprises (1) a polyoxyalkylene group-containing monomer and (2) a salt-forming group-containing monomer. And (3) A vinyl polymer obtained by polymerizing a monomer composition comprising a copolymerizable monomer with the polyoxyalkylene group-containing monomer and the salt-forming group-containing monomer. [Selection figure] None |