| abstract |
PROBLEM TO BE SOLVED: To provide a water-based ink which can obtain an image having a sufficiently large area factor and a high printing density even in a small ink droplet amount in a pigment ink, and further excellent in storage stability. SOLUTION: In an aqueous ink containing at least water, a plurality of water-soluble organic solvents, and a coloring material, the coloring material has at least one ionic group bonded to the pigment particle surface directly or through another atomic group. The plurality of water-soluble organic solvents contain a good solvent for the pigment and a poor solvent for the pigment, and the poor solvent completely or substantially solvates the pigment. In addition, the ionic group does not completely or substantially ion dissociate in the poor solvent, and the maximum Ka among the Ka values of each of the plurality of water-soluble organic solvents determined by the Bristow method A water-based ink, wherein the water-soluble organic solvent exhibiting a value is the poor solvent. [Selection figure] None |