Patent ID: 7244300

Claim:
An inkjet recording ink comprising an aqueous medium having dissolved therein a dye represented by the following formula (I), which is water-soluble and contains a lithium ion as a counter ion, wherein the total amount of a cation in said ink except for a lithium ion, a hydrogen ion, an ammonium ion, an organic quaternary nitrogen ion and an ion produced by proton addition to a nitrogen atom in a basic organic material is 0.5 wt % or less: wherein X 1 , X 2 , X 3 and X 4 each independently represents —SO-Z, —SO 2 -Z, —SO 2 NR 1 R 2 , a sulfo group, —CONR 1 R 2 or —CO 2 R 1 , and at least one of X 1 , X 2 , X 3 , and X 4 represents —SO 2 -Z or —SO 2 NR 1 R 2 ; 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, or a substituted or unsubstituted heterocyclic group; R 1 and R 2 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 or a substituted or unsubstituted heterocyclic group, and when a plurality of Zs are present, the Zs may be the same or different; Y 1 , Y 2 , Y 3 and Y 4 each independently represents a monovalent substituent, and 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, the 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 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 of a 1 to a 4 are not 0 at the same time; b 1 to b 4 each independently represents an integer of 0 to 4; M represents a hydrogen atom, a metal atom, or an oxide, hydroxide or halide thereof.