Patent ID: 7211132

Claim:
An ink set comprising at least a yellow ink composition, a magenta ink composition, and a cyan ink composition, wherein the cyan ink composition contains, as a cyan dye, at least one substance selected from the group consisting of compounds expressed by formula (1) below: and salts thereof, wherein in formula (1), each of X 1 , X 2 , X 3 and X 4 independently represents —SO—Z or —SO 2 —Z; each Z independently represents a substituted or non-substituted alkyl group, a substituted or non-substituted cycloalkyl group, a substituted or non-substituted alkenyl group, a substituted or non-substituted aralkyl group, a substituted or non-substituted aryl group, or a substituted or non-substituted heterocyclic; each of Y 1 , Y 2 , Y 3 and Y 4 independently represents a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group, an aryl group, a heterocyclic group, a cyano group, a hydroxy group, a nitro group, an amino group, an alkylamino group, an alkoxy group, an aryloxy group, an amido group, an arylamino group, a ureido group, a sulfamoylamino group, an alkylthio group, an arylthio group, an alkoxycarbonylamino group, a sulfonamide group, a carbamoyl group, a alkoxycarbonyl group, a heterocyclic oxy group, an azo group, an acyloxy group, a carbamoyloxy group, a silyloxy group, an aryloxycarbonyl group, an aryloxycarbonylamino group, an imide group, a heterocyclic thio group, a phosphoryl group, an acyl group, or an ionic hydrophilic group wherein each group may further have a substituent; a 1 to a 4 and b 1 to b 4 represent the number of substituents of X 1 to X 4 and Y 1 to Y 4 respectively; each of a 1 to a 4 independently represents an integer 0 to 4, but all of them cannot be 0 at the same time; each of b 1 to b 4 independently represents an integer of 0 to 4; M represents a hydrogen atom, a metal atom or an oxide thereof, a hydroxide, or a halide; wherein at least one of X 1 , X 2 , X 3 , X 4 , Y 1 , Y 2 , Y 3 , and Y 4 is an ionic hydrophilic group or a group having an ionic hydrophilic group as a substituent; and the magenta ink composition contains, as a colorant, at least one substance selected from the group consisting of compounds expressed by formula (2) below: and salts thereof, wherein in formula (2), A represents an alkylene group, an alkylene group containing a phenylene group, or a group expressed by formula (3) below: and X represents a group selected from the group consisting of NH 2 , OH and Cl.