Patent ID: 7758683

Claim:
An ink composition, which comprises: at least two kinds of water-soluble dyes each having the maximum wavelength of an absorption spectrum in an aqueous solvent of from 550 to 700 nm, wherein the at least two kinds of water-soluble dyes include: at least one selected from the group consisting of a compound represented by formula (L-1) and a salt of the compound represented by formula (L-1); and at least one compound having a naphthalene ring substituted with at least one hydroxyl group and three or more azo groups: wherein A and B each independently represents an aromatic group that may be substituted or a heterocyclic group that may be substituted, and A is a monovalent group and B is a divalent group; T 1 and T 2 each independently represents ═CR 43 —or —CR 44 ═, or either one represents a nitrogen atom and the other represents ═CR 43 —or —CR 44 ═; V 1 , R 43 and R 44 each independently represents a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aralkyl group, an aryl group, a heterocyclic group, a cyano group, a carboxyl group, a carbamoyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a heterocyclic oxycarbonyl group, an acyl group, a hydroxyl group, an alkoxyl group, an aryloxy group, a heterocyclic oxy group, a silyloxy group, an acyloxy group, a carbamoyloxy group, an alkoxycarbonyloxy group, an aryloxycarbonyloxy group, an amino group, an acylamino group, a ureido group, a sulfamoylamino group, an alkoxycarbonylamino group, an aryloxycarbonylamino group, an alkylsulfonylamino group, an arylsulfonylamino group, a heterocyclic sulfonylamino group, a nitro group, an alkylthio group, an arylthio group, a heterocyclic thio group, an alkylsulfonyl group, an arylsulfonyl group, a heterocyclic sulfonyl group, an alkylsulfinyl group, an arylsulfinyl group, a heterocyclic sulfinyl group, a sulfamoyl group or a sulfo group, and each of these groups may further be substituted; R 41 and R 42 , each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aralkyl group, an aryl group, a heterocyclic group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, an alkylsulfonyl group, an arylsulfonyl group or a sulfamoyl group, and each of these groups may further have a substituted, provided that R 41 and R 42 do not represent a hydrogen atom at the same time, and R 43 and R 41 , or R 41 and R 42 may be bonded to each other to form a 5- or 6-membered ring, provided that the compound represented by formula (L-1) contains at least one ionic hydrophilic group.