| 摘要 |
PURPOSE:To improve a color forming property, raw preservability and the stability of a developed color image and to bring the absorption wavelength of the developed color image to a near infrared region, by allowing to contain a fluorene derivative having a substituted amino group as an electron donating leuco dye and containing a compound having specific solubility in ethanol as an electron acceptive compound. CONSTITUTION:As an electron donating leuco dye, a fluorene derivative having a substituted amino group is contained and, as an electron acceptive compound, a compound having solubility in ethanol of 5 or less at 25 deg.C is contained. As an electron donating dye precursor, 2-anilino-3-methyl-6-dimethylaminofluorane and 2-anilino-3-methyl-6-N-methyl-N-ethylaminofluorane are designated. The electron acceptive compound is one having an acidic group and, for example, there are compounds having a phenolic hydroxyl group or an ureido group and metal salts thereof. As the electron acceptive compound, 4- deodecyloxysalicylic acid, 4-beta-phenethyloxysalicylic acid or the like are used and the electron acceptive compound is pref. used in an amount of 50-800wt.% of the electron donating dye precursor. |
