Chromogenic lactam compounds, their preparation and their use

Abstract

Chromogenic lactam compounds of the formula ##STR1## in which the ring A is an aromatic or heteroaromatic radical which has 6 ring atoms and may contain a fused aromatic ring, it being possible for both the ring A and the fused ring to be substituted; the ring B is an unsubstituted or substituted benzene ring; Z is ##STR2## R is hydrogen; unsubstituted or substituted C.sub.1 -C.sub.12 alkyl, cycloalkyl having 5 to 10 carbon atoms; unsubstituted or substituted aryl or aralkyl; C.sub.1 -C.sub.12 acyl; N-(lower alkyl)carbamoyl; or N-arylcarbamoyl which is unsubstituted or substituted on the ring; Q is C.sub.1 -C.sub.12 alkylene, aryl-C.sub.1 -C.sub.4 alkylene, 1,2-cycloalkylene, 1,2- or 1,8-arylene or aralkylene; and X.sub.1 and X.sub.2, independently of one another, are each hydrogen; unsubstituted or substituted alkyl having a maximum of 12 carbon atoms; acyl having 1 to 8 carbon atoms; cycloalkyl having 5 to 10 carbon atoms; or unsubstituted or ring-substituted aralkyl or aryl; or (X.sub.1 and X.sub.2), together with the common nitrogen atom, are a five- or six-membered, preferably saturated, heterocyclic radical. These lactam compounds are particularly suitable as color formers in pressure- or heat-sensitive recording materials and give light-fast yellow, red, violet, blue, cyan or green shades.

Dependencies are inferred from the claim text.