| abstract |
The invention relates to novel substituted 4,7-diazaphthalides of the general formula <IMAGE> wherein X and Y each independently of the other, are optionally substituted aminophenyl, indolyl, benzoindolyl, jujolidinyl or kairolyl radicals; and R1 and R2, each independently of the other, are hydrogen, lower alkyl or optionally substituted phenyl, provided that both R1 and R2 are not hydrogen. These compounds are particularly suitable for use as color formers in pressure-sensitive or heat-sensitive recording materials. |