PROCESS FOR PRODUCING AQUEOUS PIGMENT DISPERSION

摘要

A process for producing an aqueous pigment dispersion which comprises: a first step in which an emulsion composition (A) comprising a water-insoluble polymer having a specific weight-average molecular weight and a salt-forming group, an organic solvent having a specific water solubility, a neutralizing agent, and water is mixed with a pigment (B) to obtain a mixture as a predispersion having a nonvolatile content of 5-50 wt.% and an organic solvent/water ratio of 0.1-0.9 by weight; a second step in which the predispersion is continuously treated with a dispersing-medium type disperser and the resultant treated dispersion is continuously separated from the medium particles; and a third step in which the dispersion is treated with a homogenizer for further dispersing the pigment. Also provided is a water-based ink for ink-jet recording which comprises the aqueous pigment dispersion and gives a print having a high color density and excellent in gloss and marring resistance.