KROMOGENA DIKETOPYRIDINFOERENINGAR.

摘要

Chromogenic compounds of colorless or lightly colored form are disclosed having the following structural formula: wherein X represents an optionally substituted aminophenyl, indolyl, julolidinyl, kairolyl, piperidinophenyl, pyrrolidinophenyl, morpholinyl, carbazolyl or indolizinyl radical. The compounds of this invention are eligible for use in pressure-sensitive and heat-sensitive record materials and manifold marking systems.