| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a pigment water dispersion for ink jet recording, excellent in ejection durability and providing an ink having a high print density, and a pigment water dispersion for ink jet recording obtained by the method.SOLUTION: [1] The method for producing a pigment water dispersion for ink jet recording, comprises: a producing step (1) of dispersing a mixture containing water, a pigment, a water dispersible polymer and an organic solvent having a solubility of less than 40 mass% to the water until a volume average particle size of pigment particles becomes 180 nm or less to obtain a pigment dispersion; a producing step (2) of adding water to the obtained pigment dispersion and holding the resultant mixture at 40°C or less for 4-48 hours; and a producing step (3) of removing the organic solvent to obtain the pigment water dispersion. [2] The pigment water dispersion for ink jet recording obtained by the method [1] has the pigment particles having a volume average particle size of 40-150 nm. |
