| 摘要 |
PROBLEM TO BE SOLVED: To provide a water based pigment dispersion and dispersion method of a yellow azo pigment having suitable printing density and glossiness when an ink jet recording ink is used.SOLUTION: The water based pigment dispersion includes a colorant, a dispersant, an antiseptic and water. The colorant includes an azo pigment being an aggregate of a molecule represented by a following formula (1) or the tautomer thereof and having characteristic X-ray diffraction peaks at Bragg angles (2&thetas;±0.2°) of 7.2°, 13.4°, 15.0° and 25.9° in CuKα characteristic X ray diffraction. The content of polyvalent metal ions in the water based pigment dispersion is 10 ppm or less. |
