Patent ID: 7507282

Claim:
An ink composition comprising: water; a yellow dye having an oxidation potential nobler than 1.0 V; and at least one compound of an aromatic compound and a salt thereof, the at least one compound having at least one of a carboxyl group, a sulfo group and a phosphoric acid group and wherein the yellow dye is a compound represented by formula (1): wherein R 1 and R 2 each independently represents a monovalent group, Z represents a nitrogen atom, an oxygen atom, a sulfur atom or a carbon atom to which a monovalent group is bound, and M represents a hydrogen atom or a cation, provided that two azo groups exist in the molecule; and wherein the at least one compound is at least one of pyridine-2-carboxylic acid, pyridine-3-carboxylic acid, pyridine-4-carboxylic acid and a salt thereof.