Pigment dispersion with polymeric dispersants having pending chromophore groups

Abstract

A pigment dispersion includes a color pigment represented by formula (I): wherein X1 to X4 are independently selected from the group consisting of hydrogen and a halogen atom; R1 to R10 are independently selected from the group consisting of hydrogen, a halogen atom, a methyl group, an ethyl group, a methoxy group, and an ethoxy group; and a polymeric dispersant, having via a linking group covalently linked to its polymeric backbone, at least one pending chromophore group which has a molecular weight smaller than 90% of the molecular weight of the color pigment; wherein the at least one pending chromophore group is a chromophore group occurring as a side group on the polymeric backbone and not a group in the polymeric backbone itself or occurring solely as an end group of the polymeric backbone; and the at least one pending chromophore group is represented by formula (II): wherein, one of L1, L2 or L3 is the linking group and is selected from the group consisting of an aliphatic group, a substituted aliphatic group, an unsaturated aliphatic group, and a substituted unsaturated aliphatic group; L1, L2, and/or L3, if not representing the linking group, are independently selected from the group consisting of hydrogen, an alkyl group, an alkenyl group, an alkoxy group, a carboxylic acid group, an ester group, an acyl group, a nitro group, and a halogen; AR1 and AR2-represent an aromatic group; and n represents the integer 0 or 1. The pigment dispersion can be advantageously used in inkjet inks. Also disclosed are methods for preparing the inkjet ink.

Drawings

Dependencies are inferred from the claim text.