Patent ID: 7311392

Claim:
An inkjet recording ink comprising an aqueous medium having dissolved therein a phthalocyanine dye, wherein said phthalocyanine dye has an ionic hydrophilic group and is a water-soluble dye having an oxidation potential more positive than 1.0 V (vs SCE) and the ink comprises a water-miscible organic solvent having a vapor pressure of 2,000 Pa or less at 20° C. wherein said phthalocyanine dye is represented by the following formula (I): wherein X 1 , X 2 , X 3 and X 4 each independently represents —SO-Z, —SO 2 -Z, —SO 2 NR1R2, a sulfo group, —CONR1R2 or —CO 2 R1, and at least one of X 1 , X 2 , X 3 and X 4 represents —SO 2 -Z or —SO 2 NR1R2; Z 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, and R1 and R2 each independently represents a hydrogen atom, 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, provided that when a plurality of Zs are present, these may be the same or different, Y 1 , Y 2 , Y 3 and Y 4 each independently represents a monovalent substituent, provided that when a plurality of X 1 s, X 2 s, X 3 s, X 4 s, Y 1 s, Y 2 s, Y 3 s or Y 4 s are present, these may be the same or different, a 1 to a 4 and b 1 to b 4 represent the number of substituents X 1 to X 4 and Y 1 to Y 4 , respectively, a 1 to a 4 each independently represents an integer of 0 to 4 but all are not 0 at the same time, b 1 to b 4 each independently represents an integer of 0 to 4, and M represents a hydrogen atom, a metal atom or an oxide, hydroxide or halide thereof.