Patent ID: 7582151

Claim:
A pigment dispersion comprising a color pigment represented by formula (I): 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 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; 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; 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; n represents the integer 0 or 1; and the pigment dispersion is an inkjet ink and the pigment comprises 0.1 wt % to 20 wt % of the inkjet ink based on a total weight of the inkjet ink.