Patent ID: 8523990

Claim:
An ink composition comprising: a compound represented by the following formula (1); an ingredient (C); and a moisture-retentive agent, wherein the content of compound represented by the formula (1) is from 0.1 mass % to lower than 7.0 mass %, the content of moisture-retentive agent having 3 or more hydroxyl groups is 10.0 mass % or lower, the molar ratio of the moisture-retentive agent having 3 or more hydroxyl groups to the compound represented by the formula (1) is lower than 30.0: wherein each of Ar 1 and Ar 2 independently represents an aromatic cyclic hydrocarbyl group, a nonaromatic cyclic hydrocarbyl group, an aromatic heterocyclic group or a nonaromatic heterocyclic group; each of A 1 and A 2 independently represents a hydrogen atom or a substituent which may further have a substituent; Y represents —OM or —NR 1 R 2 ; M represents a hydrogen atom or a metal ion; and each of R 1 and R 2 independently represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aralkyl group, an aryl group or a heterocyclic group, wherein the ingredient (C) is at least one compound selected from the group consisting of compounds represented by the following formulae (2), (3), (4), (5) and (6): wherein each M in the formulae (2) to (5) represents a hydrogen atom or a metal ion; R in the formula (2) represents a hydrogen atom or a methyl group; and M′ − in the formula (6) represents a halogen ion, an inorganic anion or an organic anion.