WATER-BASED INK, INKJET RECORDING METHOD, INK CARTRIDGE, RECORDING UNIT, INKJET RECORDING DEVICE AND IMAGE-FORMING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a water-based pigment ink which has a sufficiently large area factor even in a small ink liquid drop amount, can give images having high printing concentrations, and has excellent storage stability.

SOLUTION: This water-based ink comprising at least water, a plurality of water-soluble organic solvents and a coloring material is characterized by the following characteristics. The coloring material is a pigment to whose surface at least one ionic group is bound directly or through one or more atom groups. The water-soluble organic solvents comprise a good solvent for the pigment and a poor solvent for the pigment. The poor solvent does perfectly or substantially not solvate the pigment. The ionic group is perfectly or substantially ionically not dissociated in the poor solvent. And a water-soluble organic solvent exhibiting the maximum Ka value among the Ka values of the water-soluble organic solvents, determined by Bristow method, is the above-mentioned poor solvent.

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