Patent ID: 7211133
Filing Date: 2007-05-01
Classification: C09D

Abstract:
1. An inkjet black ink comprising an aqueous medium having dissolved or dispersed therein two or more kind of dyes, wherein the inkjet black ink has an enforced discoloration rate constant (k the inkjet black ink contains at least one dye of an azo dye having a heterocyclic group and a phthalocyanine dye, wherein the printing by using the inkjet black ink is a printing of a black square symbol of JIS Code 2223 in a 48-point size and the inkjet black ink contains at least one dye represented by the following formulae (1) to (4): Formula (1): Formula (4): wherein in formula (1), A 11 and B 11 each independently represents a heterocyclic group which may be substituted; in formula (2), X in formula (3), A in formula (4), A, B and C each independently represents an aromatic group or a heterocyclic group which may be substituted.