| 摘要 |
<p>Heterocyclic substituted fluoran compounds of the formula WHEREIN R1, R2 and R3 independently of the other, represent hydrogen, alkyl with one to four carbon atoms, nitro or halogen, or R2 and R3 together complete a condensed carbocyclic ring, X1 and X2 independently of the other, represent hydrogen, alkyl with one to 12 carbon atoms, alkenyl with at most 12 carbon atoms, alkoxyalkyl with two to eight carbon atoms, alkoxycarbonylalkyl with three to nine carbon atoms, cycloalkyl with five or six carbon atoms, acyl having one to 12 carbon atoms, or optionally substituted benzyl, phenyl or naphthyl, and THE NITROGEN RING A represents a heterocyclic radical which optionally includes a further hetero atom as a ring member and the benzene ring B may be further substituted by nitro or one to four halogen atoms. These fluorans compounds are particularly useful as colour formers which give intense dark green, grey black or red colours when they are brought into contact with an electron-accepting co-reactant.</p> |
