| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an aqueous pigment dispersion excellent in initial and long-term dispersibility in an aqueous solvent, resistant to pigment particle agglomeration, and thus excellent in storage stability and to provide an ink composition. <P>SOLUTION: The aqueous pigment dispersion is prepared by dispersing in water a hydrophilic organic pigment having a benzimidazolone structure in which the maximum absorption wavelength λ<SB>max</SB>in an absorption spectrum in the visible light region appears between 500 nm and 600 nm and chemically sulfonated to introduce sulfo groups onto its surface, wherein an amine compound is contained, and the relationships: 0 < X < 4.0 (1) and 0 < Y < 0.65X<SP>2</SP>- 0.6X + 3.2 (2) äwherein X (wt.%) is the pigment concentration, and Y (cP) is the viscosity of the dispersion} are satisfied. <P>COPYRIGHT: (C)2004,JPO |
