Patent ID: 8741045

Claim:
An ink composition comprising at least one kind of a compound represented by the following formula (1) or a tautomer thereof or a salt thereof as a coloring matter (1): wherein, R 1 and R 2 each independently represent a hydrogen atom; a halogen atom; a cyano group; a carboxy group; a sulfo group; a sulfamoyl group; an N-alkylaminosulfonyl group; an N,N-dialkylaminosulfonyl group; an N-phenylaminosulfonyl group; a phospho group; a nitro group; an acyl group; a ureido group; a C1-C4 alkyl group; a C1-C4 alkyl group substituted with a hydroxy group or a C1-C4 alkoxy group; a C1-C4 alkoxy group; a C1-C4 alkoxy group substituted with at least one kind of a group selected from the group consisting of a hydroxy group, a C1-C4 alkoxy group, a sulfo group, and a carboxy group; or an acylamino group; R 3 and R 4 each independently represent a hydrogen atom; a halogen atom; a cyano group; a carboxy group; a sulfo group; a nitro group; a C1-C4 alkyl group; a C1-C4 alkoxy group; or a C1-C4 alkoxy group substituted with at least one kind of a group selected from the group consisting of a hydroxy group, a C1-C4 alkoxy group, a sulfo group, and a carboxy group; n is 0 or 1; and the group A is a group represented by the following formula (2): wherein, R 5 represents a cyano group; a carboxy group; a C1-C4 alkyl group; a C1-C4 alkoxycarbonyl group; or a phenyl group; and R 6 , R 7 and R 8 each independently represent a hydrogen atom; a halogen atom; a cyano group; a carboxy group; a sulfo group; a nitro group; a C1-C4 alkyl group; a C1-C4 alkoxy group; a C1-C4 alkoxy group substituted with at least one kind of a group selected from the group consisting of a hydroxy group, a C1-C4 alkoxy group, and a sulfo group; or an acylamino group, at least one kind of a compound represented by the following formula (3) or a tautomer thereof or a salt thereof as a coloring matter (II): wherein, m is 0 or 1; R 101 to R 103 each independently represent a hydrogen atom; a sulfo group; or a C1-C4 alkoxy group; and the group D represents a phenyl group or a naphthyl group substituted with one to three sulfo groups, and at least one kind of a compound represented by the following formula (4) or a salt thereof as a coloring matter (III): wherein, R 201 to R 204 each independently represent a hydrogen atom; or a C1-C4 alkoxy group substituted with a sulfo group.