AQUEOUS PIGMENT DISPERSION AND INK COMPOSITION FOR INKJET RECORDING

摘要

Disclosed is a red-orange ink composition for inkjet recording which achieves high chroma and high gloss while maintaining adequate long-term storage stability and ejection stability. Also disclosed is an aqueous pigment dispersion liquid for a main component of such an ink composition. Specifically disclosed is an aqueous pigment dispersion liquid which contains a styrene-acrylic acid copolymer containing not less than 60% by mass of a styrene monomer unit relative to the total monomer components and having an acid number of 130-200 and a weight average molecular weight of 6,000-40,000; an alkali metal hydroxide; a wetting agent; and pigment red 168. This aqueous pigment dispersion liquid is excellent in storage stability and exhibits high gloss. An ink composition mainly containing such an aqueous pigment dispersion liquid has good ejection stability due to excellent dispersibility of the aqueous pigment dispersion liquid while exhibiting excellent light resistance.