Patent ID: 7293867

Claim:
An ink for ink jet recording, comprising an aqueous medium and a phthalocyanine dye represented by the following formula (I) dissolved or dispersed in the aqueous medium, wherein the phthalocyanine dye has an oxidation potential of more positive than 1.0 V and the ink has a conductivity of 0.01 S/m to 10 S/m: wherein X 1 , X 2 , X 3 and X 4 each independently represent —SO-Z, —SO 2 -Z, —SO 2 NR 1 R 2 , a sulfo group, —CONR 1 R 2 or —CO 2 R 1 ; 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; R 1 and R 2 each independently represent 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; and when there are a plurality of Z's, they may be the same or different; Y 1 , Y 2 , Y 3 and Y 4 each independently represent a monovalent substituent; and when there are a plurality of any of X 1 to X 4 and Y 1 to Y 4 , they 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 represent an integer of from 0 to 4 and are not 0 at the same time; and b 1 to b 4 each independently represent an integer of 0 to 4; M represents a hydrogen atom, metal atom or oxide, hydroxide or halide thereof and the phthalocyanine structure has at least one of —SO 2 -Z and —SO 2 NR 1 R 2 at a beta-position thereof.