| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a pigment dispersion in which a pigment is finely dispersed and which has excellent flowability in a region where pigment concentration is high and also has excellent dispersion stability of the pigment in a diluted state when stored for a long period of time, an ink composition suitable for inkjet recording including the pigment dispersion, and printed matter. <P>SOLUTION: The pigment dispersion is provided, which contains: (a) 2-35 mass% of a pigment; (b) 10-30 pts.mass of a polymer including 5-30 mass% of a repeating unit represented by general formula (1) and having a weight-average molecular weight of 10,000-200,000 based on 100 pts.mass of (a) the pigment; and (c) 15-50 pts.mass of a graft copolymer having a polyalkyleneimine chain or a polyallylamine chain in a main chain thereof and a polyester chain in a side chain thereof based on 100 pts.mass of (a) the pigment, wherein the total of the contents of (b) the polymer and (c) the graft copolymer is 25-70 pts.mass based on 100 pts.mass of (a) the pigment. The ink composition including the pigment dispersion and the printed matter are also provided. In formula, R<SP>1</SP>is a hydrogen atom or a methyl group; J is -CO-, -COO-, -CONR<SP>2</SP>-, -OCO-, or a phenylene group; R<SP>2</SP>is a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group; W is a single bond or a divalent linking group; and P is a heterocyclic ring residue having a heterocyclic ring included in an organic pigment. <P>COPYRIGHT: (C)2011,JPO&INPIT |
