Aqueous cyan pigment slurry and ink composition comprising the same

Abstract

This invention provides an aqueous dispersion of a cyan pigment, comprising: 10 wt% to 25 wt% of a phthalocyanine pigment, which is a copper phthalocyanine pigment, a nickel phthalocyanine pigment, or a combination thereof; 0.2 wt% to 10 wt% of a saturated fatty acid salt, which is a metal salt of a C10-18 straight-chain or branched fatty acid; 0.2 wt% to 10 wt% of an ionic dye, which is a phthalocyanine dye, a triphenodioxazine dye, an anthraquinone dye, or a combination thereof containing at least one ionic group; and water. This invention further provides an ink composition formulated with this aqueous dispersion of a cyan pigment. An aqueous cyan pigment slurry is provided, which comprises: 10 wt% to 25 wt% of phthalocyanine pigment, which is a Cu phthalocyanine pigment, Ni phthalocyanine pigment or a combination thereof; 0.2 wt% to 10 wt% of saturated fatty acid salts, which is a metal salt of C10-18 linear or branch fatty acid; 0.2 wt% to 10 wt% of an ionic dye comprising phthalocyanine dye, triphenodioxazine dye, anthraquinone dye or a combination thereof with at least one ionic group; and water. The present invention further provides an ink composition formulated with the aqueous cyan pigment slurry.