Patent ID: 8222318
Filing Date: 2012-07-17
Classification: C08F,C09B,C09D

Abstract:
1. A process for producing a water dispersion for ink-jet printing containing particles of a polymer which contain a colorant, comprising the following steps I to IV: Step I: dispersing a mixture containing a polymer, a colorant, an organic solvent (A) and water to obtain a dispersion of colorant-containing polymer particles; Step II: removing the organic solvent (A) from the dispersion obtained in the step I to obtain a water dispersion of the colorant-containing polymer particles; Step III: mixing the water dispersion obtained in the step II with an organic solvent (B) to control a relative dielectric constant (α) of a mixed solvent of dispersing medium of the water dispersion and the organic solvent (B), wherein the relative dielectric constant (α) of the mixed solvent is controlled to from 27 to 62, thereby precipitating the polymer particles; and Step IV: separating precipitates obtained in the step III from the dispersion and re-dispersing the precipitates in a water-based solvent.