| 摘要 |
Compounds of the formula <IMAGE> (I) wherein Z1 denotes hydrogen, alkyl, cycloalkyl or <IMAGE> R1 denotes hydrogen, alkyl, cycloalkyl, aralkyl, aryl, heteroalkyl or heteryl, X1, X2 and X3 denote hydrogen, halogen, alkyl, cycloalkyl, aryl, alkanoylamino, aroylamino or heteryl, and at least one of these radicals denotes NH1Y2, OY3 or SY3, Y1, Y2 and Y3 denote hydrogen, alkyl, cycloalkyl, aralkyl, aryl or heteryl and Y1+Y2 denote the remaining members of a 5-membered or 6-membered ring which optionally contains further hetero-atoms, are outstandingly suitable as colour-forming agents for pressure-sensitive, heat-sensitive and electrosensitive recording materials with an acid developer. Deep copies which are fast to light are obtained.
|
