Patent number: 4897223
Abstract: Color-forming agents of the general formula ##STR1## wherein X denotes hydroxyl, alkoxy, alkenyloxy, aralkoxy, cycloalkoxy, aryloxy, acyloxy, alkoxycarbonyloxy, alkylamino, dialkylamino, acylamino, aralkylamino or arylamino,Q denotes cyano, alkoxycarbonyl, aryloxycarbonyl, aralkoxycarbonyl, carbamoyl, N-alkylcarbamoyl, N,N-dialkylcarbamoyl, N-alkyl-N-aryl-carbamoyl, acyl, alkoxysulphonyl, aralkoxysulphonyl, sulphamoyl, N-alkylsulphamoyl, N,N-dialkylsulphamoyl, alkylsulphonyl, arylsulphonyl or aralkylsulphonyl andR denotes alkyl, alkenyl or aralkyl,further isocyclic or heterocyclic rings can be fused on to the rings A, B, C and D, and the cyclic and acyclic radicals and the rings A, B, C and D can carry further substituents, are used for the preparation of pressure-sensitive recording materials.
Type:
Grant
Filed:
March 1, 1988
Date of Patent:
January 30, 1990
Assignee:
Bayer Aktiengesellschaft
Inventors:
Udo Eckstein, Hubertus Psaar, Roderich Raue