| 摘要 |
PURPOSE:To enhance the stability of a developed color image, by using a p- substituted aminophenylindolylphthalide derivative and a bisindolylphthalide derivative as a leuco dye. CONSTITUTION:As an electron donative leuco dye, p-substituted amino phenylindolylphthalide derivative and a bisindolylphthalide derivative are used and, as electron acceptive compound, an org. acid having one or more phenolic hydroxyl group is used. As the p-substituted aminophenylindolylphthalide deriva tive, 4-substituted amino-2-alkoxyphenylindolylphthalide is pref. from the aspect of the developed color and thereof. The substituent of the indolyl skeletal of the bisindolylphthalide derivative is pref. the same to that of the indolyl skeletal of the p-substituted aminophenylindolylphthalide derivative. As the electron acceptive compound used in a recording material, a salicylic acid derivative compound used in a recording material, a salicylic acid derivative is pref. from the aspect of color developability, developed color hue and the light fastness of a developed color image. The developed color dye of this recording material is markedly stable and generates almost no discoloration and fading even under long-time light irradiation, heating and humidifying conditions. |
