| 摘要 |
PURPOSE:To obtain a recording material developing color in a sufficient density in the presence of an electron donating colorless dye and to enhance shelf stabilities in raw and with time, by using a specific compound as an electron accepting compound. CONSTITUTION:An electron accepting compound shown by a formula is used as an electron accepting compound for a thermal recording material. Bishydroxy phenylalkane carboxylic acid is reacted with dihaloalkane or diol derivative to synthesize the electron accepting compound having 50 deg.C or above melting point. A compound of triarylmethane series, diphenylmethane series, xanthene series, thiazine series, and/or spiropyran series are/is used as an electron donating colorless dye, and singly or mixedly dissolved in a solvent. The obtained solution is dispersed in a binder or contained in a micro-capsule and thereafter coated on a substrate of resin coated paper etc. to obtain a coupler sheet. On the other hand, the electron accepting compound of one or more kind is singly or mixedly dispersed in a binder and thereafter coated on a substrate of resin coated paper etc. to obtain a developer sheet. |
