| 摘要 |
PROBLEM TO BE SOLVED: To obtain a pigment ink which can form a picture excellent in fastness such as water-resistance, light resistance, etc., and in letter properties, and has the higher jet efficiency when applied to recording of an ink jet by incorporating a self-dispersing carbon black, an aqueous medium and a silicon compound. SOLUTION: As a coloring material, a self-dispersing type carbon in which at least one hydrophilic group is bound on a surface of carbon black through other atomic group is used. Both anionic and cationic group are used as the hydrophilic one. The anionic hydrophilic group contains, for example, -COOM, -SO3M, -PO3HM (wherein M is H, an alkaline metal, ammonium or the like) or the like. The cationic hydrophilic group contains -SO2N+H3, -N+R3, a group of the formula (wherein R is a 1-12C alkyl, a phenyl or a naphthyl) or the like. The above other atomic group contains, for example, a 1-12C alkylene, a phenylene, a naphthylene or the like. As a silicon compound, a silicon surfactant is preferable, for example. |
