Method of inkjet printing green images

摘要

Aqueous green inkjet ink compositions are prepared from aqueous organic pigment dispersions for use in various inkjet printing methods. In particular, these methods provide a green image or expanded color gamut for other inkjet printed colors. The aqueous organic pigment dispersion contains a green copper phthalocyanine pigment and an azo-coupled β-ketoamide pigment and an organic pigment dispersant. The weight ratio of the green copper phthalocyanine pigment to the azo-coupled β-ketoamide pigment is from 1:1 to 10:1. The median particle diameter of each of the green copper phthalocyanine pigment and the azo-coupled β-ketoamide pigment is less than 85 nm. At least 95% of the total particles of each of the green copper phthalocyanine pigment and the azo-coupled β-ketoamide pigment have a particle diameter of less than 150 nm.

主权项

1. A method of inkjet printing, comprising:
providing a substrate, ink jetting an aqueous green inkjet ink composition as spaced green drops to provide a green color image on the substrate,
wherein the aqueous green inkjet ink composition comprises:(a) an aqueous organic pigment dispersion comprising:a green copper phthalocyanine pigment,an azo-coupled β-ketoamide pigment, andat least one organic pigment dispersant in an amount of at least 40 weight % and up to and including 100 weight %, based on the sum of the weights of the green copper phthalocyanine pigment and the azo-coupled β-ketoamide pigment,the weight ratio of the green copper phthalocyanine pigment to the azo-coupled β-ketoamide pigment is from 1:1 to and including 10:1, andthe median particle diameter of each of the green copper phthalocyanine pigment and the azo-coupled β-ketoamide pigment is less than 85 nm and at least 95% of the total particles of each of the green copper phthalocyanine pigment and the azo-coupled β-ketoamide pigment have a particle diameter of less than 150 nm when measured in intensity mode using a laser light scattering particle size analyzer, and(b) at least one humectant,the aqueous green inkjet ink composition having a viscosity of less than 3 centipoise (0.003 N-sec) at 25° C.