| 摘要 |
PURPOSE:To enhance a color forming property, raw preservability and the stability of a developed color image, by using a p-substituted aminophenylindolylphthalide derivative and/or a p-substituted aminophenylindolylazaphthalide derivative having a substituted alkyl group as a leuco dye. CONSTITUTION:As an electron donating leuco dye, a p-substituted aminophenylindolylphthalide derivative and/or p-substituted aminophenylindolylazaphthalide derivative having a substituted alkyl group is used. This electron donating leuco dye is a colorless or light-colored crystal and has high solubility to an org. solvent and has a benefit of rapidly developing a blue color upon the contact with an electron acceptive substance. The developed color is extremely stable as compared with the color generated from an existing color former and almost generates no discoloration and fading after the long-time irradiation of light, heating and humidification and, therefore, this recording material is advantageous from the aspect of the long-term preservation of recording. The color former also has excellent stability and generates no deterioration and coloration even after long-term preservation and has sufficient color forming capacity and capacity next to an ideal as the color former of a recording material such as pressure-sensitive or heat-sensitive paper. |
