| 摘要 |
PURPOSE:To provide a sufficient developed color density and enhance preservability in raw state and preservability with time, by using an electron- donative colorless dye and a specified electron-acceptive compound. CONSTITUTION:An electron-donative colorless dye and an electron-acceptive compound of formula (I), wherein X is hydrogen, lower alkyl or halogen, and (n) is an integer of 2-8, are used. The substituent X is preferably 1-4C alkyl, chlorine, bromine or hydrogen, particularly, methyl, ethyl, chlorine or hydrogen, and n is preferably 2-6. The electron-acceptive compound gives a developed color image with high density when being used in combination with the electron- donative colorless dye. In addition, preservability of ground and the developed color image is favorable, and stability is ensured because of the lack of sublimability. |
