Patent ID: 7066992

Claim:
An ink composition comprising a dye, wherein said dye comprises a structure of Formula 2: wherein R 1 represents a hydrogen atom, a cyano group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aralkyl group, an alkylthio group, an arylthio group, an acyl group, a substituted acyl group, a carboxyl group, a carbamoyl group, or a heterocyclic group; R 7 represents a hydrogen, a substituted or unsubstituted alkyl or a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkyoyl group or a heterocyclic group; R 2 represents, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryt group, a halogen, a cyano group, a carboxyl or substituted carboxyl group, an acyl group, a substituted acyl group, a carbarnoyl group, a nitro group, an alkyl or aryl sulfone, a sulfonic acid, a substituted or unsubstituted primary or secondary alkyl sulfonamide, a substituted or unsubstituted aryl sulfonamide or a heterocyclic group; R 3 may be hydrogen or any non-metallic group; R 4 , R 5 , R 6 may be H or any non-metallic group with the proviso that at least one of R 4 or R 6 represents any ionizable group which is capable of imparting water solubility to the dye; R 5 may be present in any other position on the aromatic ring that is not occupied by R 4 or R 6 .