Patent ID: 7731788

Claim:
An ink set comprising at least a yellow ink composition, a magenta ink composition, and a cyan ink composition: the magenta ink composition containing as a colorant at least one type of compound expressed by the following Formula M-1 wherein in Formula M-1, M represents a hydrogen atom, an ammonium group, or an alkali metal atom, X represents a diaminoalkylene group, and n is either 1 or 2; the yellow ink composition containing as a colorant at least one type of compound expressed by the following formula Y-1 wherein in the formula Y-1, X 1 , X 2 , Y 1 , and Y 2 represent a hydrogen atom or a cyano group, Z 1 and Z 2 represent a substitution group with an aromatic ring, R 1 and R 2 represent an alkyl group, and M is a metal atom; and the cyan ink composition containing as a colorant at least one type of compound selected from the group consisting of compounds or salts thereof expressed by the following Formula C-1 wherein in Formula C-1, X 1 , X 2 , X 3 , and X 4 independently represent either —SO—Z or —SO 2 —Z; wherein Z independently represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group; Y 1 , Y 2 , Y 3 , and Y 4 independently represent 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, an hydroxyl group, a nitro group, an amino group, an alkylamino group, an alkoxy group, an aryloxy group, an amido group, an arylamino group, an ureido group, a sulfamoylamino group, an alkylthio group, an arylthio group, an alkoxycarbonylamino group, a sulfonamide group, a carbamoyl group, an alkoxycarbonyl group, a heterocycloxy group, an azo group, an acyloxy group, a carbamoyloxy group, a silyloxy group, an aryloxycalbonyl group, an aryloxycalbonylamino group, an imido group, a heterocyclothio group, a phospholyl group, an acyl group, or an ionic hydrophilic group, and each of the groups may also have substitution groups; a 1 through a 4 and b 1 through b 4 represent the number of substitution groups of X 1 through X 4 and Y 1 through Y 4 ; furthermore a 1 through a 4 are independently integers between 0 and 4, but are not all simultaneously 0; b 1 through b 4 are independently integers between 0 and 4; M represents a hydrogen atom, a metal atom or oxide thereof, a hydroxide, or a halide; with the proviso that, 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 which has an ionic hydrophilic group as a substitution group.