INK, INK CARTRIDGE AND INKJET RECORDING METHOD

摘要

PROBLEM TO BE SOLVED: To provide an ink that is excellent in evaporation stability and capable of providing an excellent image high in image density irrespective of the kind of a recording medium used; and to provide an ink cartridge and an inkjet recording method using the ink.

SOLUTION: Disclosed herein are an ink containing a self-dispersible pigment and a salt, wherein the self-dispersible pigment is a pigment to the surface of a particle of which a functional group containing at least a group having a hydrogen bonding property and two phosphonic acid groups is bonded. In the ink composition, counter ions of the two phosphonic acid groups containing one of K+and NH4+; the salt is constituted by combining at least one cation of K+and NH4+with at least one anion selected from the group consisting of halogen ions and the like; a cation concentration in the ink is 0.04 mol/L or more; and the viscosity of a liquid obtained by evaporating 15 mass% of the ink is less than 3.5 mPa s at 25°C.

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