| 摘要 |
PROBLEM TO BE SOLVED: To provide, without using consumable goods other than an ink such as reaction liquids, etc., an ink composition capable of obtaining high-quality images on various recording papers.SOLUTION: The provided aqueous ink composition is an aqueous ink composition including a pigment, an aqueous solvent, a polymer, and a nonionic pigment dispersant. In the aqueous ink composition, the polymer is a polymer capable of varying the viscosity of the aqueous ink composition based on the variation of the pH of the aqueous ink composition, and dispersion particle diameters of the pigment within the aqueous ink composition are less than 170 nm. The surface tension of the aqueous ink composition is 52 mN/m or more. In this aqueous ink composition, the polymer is an ABA tri-block polymer including an A block comprising a monomer consisting of an acrylic acid ester or acrylamide possessing a terminal carboxyl group or amine group and a B block comprising a hydrophilic monomer possessing a radical-polymerizable unsaturated bond. |
