The present invention discloses novel fluoran compound useful as the lactone electron donative color-forming agents having the general formula: ##STR1## wherein, R.sub.1, R.sub.2 and R.sub.4 are respectively hydrogen, methyl or ethyl groups; R.sub.3 is hydrogen or a methyl group; and R.sub.5 is a phenyl group or a phenyl group substituted with from one to five methyl groups. The compound of the invention is soluble in aromatic solvents as well as in aromatic-aliphatic mixed solvents and also has excellent light fastness after developing color.
本发明公开了一种新型的
氟兰化合物,作为
乳酸酯电子给体色彩形成剂,其具有以下通式:其中,R₁、R₂和R₄分别为氢、甲基或乙基基团;R₃为氢或甲基基团;R₅为苯基或苯基,其上有1至5个甲基基团。该化合物在芳香溶剂以及芳香-脂肪族混合溶剂中溶解,并且在形成颜色后具有优异的耐光性。