Patent ID: 6451103
Filing Date: 2002-09-17
Classification: C09B,C09D

Abstract:
A self-dispersible aqueous pigment dispersion comprising an aqueous solution, particles of a pigment and a water-soluble pigment derivative, said particles being dispersed in the aqueous pigment dispersion in a concentration within the range from 2 to 25 wt. % based on the amount of the aqueous pigment dispersion,wherein a part of the water-soluble pigment derivative is adsorbed on the surface of the particles of the pigment to form dispersed particles comprising the particles of the pigment adsorbed by said part of the pigment derivative, and, the remaining parts of the water-soluble pigment derivative are free in the dispersion without being adsorbed on the surface of the pigment in a concentration less than the critical flocculation concentration on which flocculation is initiated on said particles of the pigment dispersed under said concentration, wherein said pigment is selected from the group (1) consisting of quinacridone pigments, phthalocyanine pigments, azo pigments, diketopyrrolopyrrole pigments, threne pigments, perynone pigments, perylene pigments, dioxazine pigments, isoindolinone pigments, benzimidazolone pigments, anthraquinone pigments, and mixtures thereof, and the water-soluble pigment derivative is a pigment selected from said group (1), further substituted by an acidic functional group or salt thereof.