| abstract |
The present invention provides a novel phthalide compound represented by the following formula, which rapidly forms blue-blue black color with a developer when it is used as a recording material and, since a color image formed therewith has an intense absorption at 700 SIMILAR 850 nm, it is usable for optical character reader; <IMAGE> where R<1>, R<2>, R<3>, and R<4> represent, independently, alkyl; cycloalkyl; aryl or heterocyclic ring connecting R<1>, R<2> and N; X<1> SIMILAR X<3> represent, independently, hydrogen, alkyl, alkoxy or halogen; X<4> represents hydrogen, alkyl, alkoxy, halogen or <IMAGE> |