LACTONE COMPOUNDS CONTAINING AN INDOLIZINE RADICAL

摘要

Chromogenic compounds of normally colorless form are disclosed having the following structural formula: wherein E represents a six-membered aromatic or heterocyclic ring which may have an aromatic condensed ring or a naphthalene ring and both the E ring and the condensed ring may be substituted, a represents an optionally substituted aminophenyl, indolyl, benzolndolyl, julolidinyl or kalrolyl radical or the radical represented by B, and B represents a family of indolizine radicals. The compounds of this invention are eligible for use in pressure-sensitive and heat-sensitive record materials and manifold marking systems.