| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a water-based pigment dispersion which method substantially reduces the number of coarse particles in the manufactured water-based pigment dispersion, reduces the size of the dispersed particles, enables to improve the stability of the dispersion, thereby realizes storage stability improvement and the good discharge stability in the manufacture of a water-based ink for inkjet printing, and is excellent in production efficiency. <P>SOLUTION: The method for manufacturing a water-based pigment dispersion comprises: a kneading step in which a pigment dispersion that is solid at room temperature and is produced by kneading a mixture containing a quinacridone pigment (a), a styrene-acrylate copolymer (c), a basic compound (d), and polyethylene glycol (e) of 50-500 (mgKOH/g) hydroxyl value; and a mixing step in which an aqueous medium is mixed with the pigment dispersion to reduce the viscosity and to liquefy the pigment dispersion. <P>COPYRIGHT: (C)2012,JPO&INPIT |
