Patent ID: 8729153

Claim:
An aqueous pigment dispersion for an ink-jet ink, comprising C.I. Pigment Yellow 74, a styrene-acrylic-based resin with an acid number of 100 to 250 and a glass transition temperature of at least 90° C., a sulfonic acid group-containing acetoacetic acid arylamide-based azo compound represented by a general formula (7) shown below: (wherein, R1, R2 and R3 each represent, independently, a hydrogen atom, methyl group, methoxy group, or ethoxy group), and an alkali metal hydroxide, wherein said styrene-acrylic-based resin comprises at least styrene-based monomer units, acrylic acid monomer units, and methacrylic acid monomer units as component monomer units, a proportion of said styrene-based monomer units relative to a combined total of all monomer units is at least 50% by weight; a sum of said styrene-based monomer units, said acrylic acid monomer units, and said methacrylic acid monomer units, relative to a combined total of all monomer units, is at least 95% by weight; and a weight average molecular weight of said resin is within a range from 7,000 to 15,000.