Patent ID: 7176248
Filing Date: 2007-02-13
Classification: C09D

Abstract:
1. An aqueous inkjet ink comprising a self-dispersing pigment, a polyurethane dispersion and water, wherein the polyurethane dispersion has acid groups and the acid number of the polyurethane dispersion is about 18 to 40, and wherein the ink has a surface tension in the range of about 20 mN/m to about 70 mN/m at 25° C., and a viscosity in the range of about 1 mPa·s to about 30 mPa·s at 25° C., provided that the self-dispersing pigment comprises a pigment that has been oxidatively treated on its surface with hypochlorous acid, sulfonic acid, or ozone so as to bond at least one functional group selected from the group consisting of carbonyl, carboxyl, hydroxyl and sulfone, onto the surface of the pigment, and further wherein a combination of two or more polyurethane dispersions is used.