Patent ID: 7973197

Claim:
A colorant compound having a structure represented by general formula (1): wherein each of R 1 through R 4 independently denotes a hydrogen atom, an alkyl group that may be substituted, an aryl group that may be substituted or an aralkyl group that may be substituted, each of R 5 and R 6 independently denotes a hydrogen atom or an alkyl group and R 7 denotes a hydrogen atom, a sulfonic acid group, an amino group that may be substituted or —SO 2 NR 9 R 10 , wherein each of R 9 and R 10 independently denotes an alkyl group, an aryl group, or an aralkyl group and may form a heterocycle with a nitrogen atom; n denotes an integer between 1 and 3; and if R 7 is not —SO 2 NR 9 R 10 , at least one of R 1 through R 4 is an alkylene group, an arylene group, or an aralkylene group having —SO 2 NR 9 R 10 as a substituent.