| 摘要 |
PROBLEM TO BE SOLVED: To obtain an ink set which gives a print with a reduced bleeding between a color ink and a black ink on plain paper by using a black ink contg. an anionic pigment and a color ink contg. a colorant and a cation source selected from among cationic surfactants, cationic salts, and mixtures thereof. SOLUTION: The black pigment used in the black ink is a self-dispersible anionic pigment, including all the water-dispersible anionic black pigments chemically modified for ink jet printing. The color ink contains at least one colorant, dye, or pigment, and an aq. color pigment, such as a sulfonate or carboxylate, is pref. used. The color ink contains about 0.5-5 wt.% cationic surfactant or about 0.1-7 wt.% cationic salt, which is effective in inhibiting bleed between the black and the color ink. The cationic salt is selected pref. from among tetraalkyl-, tetraaryl-, and tetraalkylarylammonium salts. |
