| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a pigment compound for black ink, which has high solubility over a medium containing water as a main component, is stable even if high concentration aqueous solution and the ink are stored for a long period of time, has high printed image density, does not cause bronzing of the image even when printed using a high concentration solution, and gives a black printed image excellent in the fastness of the printed image; and to provide an ink composition using the pigment composition. <P>SOLUTION: The pigment compound is an azo compound represented by formula (1) or its salt, wherein n is 1, or the like, R<SP>1</SP>is an alkyl group, or the like, R<SP>2</SP>is a cyano group, or the like, R<SP>3</SP>and R<SP>4</SP>are each independently a hydrogen atom, a sulfo group or the like. R<SP>5</SP>to R<SP>7</SP>are each independently a hydrogen atom, an alkyl group, a sulfoalkoxy group, or the like, X, Y and Z are an NH group, or the like, R<SP>8</SP>is a sulfoalkyl group, or the like, a group A is a substituted phenyl group, or the like, and a group B is a substituted phenylene group, or the like. <P>COPYRIGHT: (C)2011,JPO&INPIT |
