| 摘要 |
PROBLEM TO BE SOLVED: To obtain a water-based ink composition containing a pseudo-one- dimensionally crystalline fuchsine organic pigment, causing no blot in plain paper printing, and enabling high-quality (high-minuteness, high-chroma) printing with high water resistance, light resistance and fretting resistance and high developed color density with low pigment concentration. SOLUTION: This fuchsine ink composition contains as coloring material a mixed pigment consisting of the pseudo-one-dimensionally crystalline fuchsine organic pigment (M1) and another fuchsine organic pigment (M2), wherein the pigment M1 shows as the main peaks a diffraction line presenting the maximum intensity and a n-th ((n) is an integer of >=2) diffraction line in the X-ray diffraction spectrum, and for the pigment M1, the intensity ratio (I2 /I0 ) is <0.2 and that for the pigment M2 is >=0.2 (I0 is the intensity of the diffraction line presenting the maximum intensity, and I2 is the intensity of the 2nd diffraction line). |
