PURPOSE: To obtain a mercury-free sensitizer applicable to a photosensitive and thermosensitive copying material by imparting carboxyalkyl substituents each having an alkyl chain contg. a specified number of C atoms to both N atoms of a cyanine chromophore.
CONSTITUTION: This sensitizer is a heptamethycyanine dye in which both N atoms of the cyanine chromophore have carboxyalkyl substituents each having an alkyl chain contg. at least 5 C atoms. The dye has a nucleus represented, e.g. by the formula, wherein (p) is 0 or 1, each of m1 and m2 is 0 or 1, X is an anion, each of R1 and R2 is 5-25C alkylene and each of Z1 and Z2 is a group of atoms required to complete a heterocyclic ring or a condensed ring such as thiazole, oxazole or its deriv. contg. one or more condensed benzene rings.
DEIBITSUDO BII ORIFU
JIEIMUZU BAANAADO FUIRITSUPU
