Infrared filter dye for photographic element.

摘要

A infrared absorbing filter dye that also imparts a cool image tone after processing is disclosed for use in photographic elements. The dye has the formula: <CHEM> where Z and Z min each independently represent the atoms necessary to complete a substituted or unsubstituted benzothiazole nucleus, benzoselenazole nucleus, indole nucleus, naphthothiazole nucleus, naphthoselenazole nucleus, or benzindole nucleus, R1 and R2 each independently represents alkyl of from 1 to 8 carbon atoms or sulfoalkyl, carboxyalkyl, or sulfatoalkyl of from 2 to 6 carbon atoms, with the proviso that when Z and Z min are sulfosubstituted benzindole nuclei, R1 and R2 have at least 3 linear carbon atoms between the heterocyclic nitrogen atom and the sulfo or sulfato group if they are sulfoalkyl or sulfatoalkyl, or at least 2 linear carbon atoms between the heterocyclic nitrogen atom and the carboxy group if R1 and R2 are carboxyalkyl, Z sec represents the atoms necessary to complete a substituted or unsubstituted piperidyl ring, a substituted or unsubstituted pyrrolidyl ring, and substituted or unsubstituted pyrazinyl ring.