| 摘要 |
PURPOSE:To obtain a thermal recording material not generating the fog of a blank part and the deterioration of recording density even when exposed to temp. environment by using a specific basic dye and a specific coupler in a specific ratio. CONSTITUTION:In a thermal recording medium utilizing the color forming reaction of a colorless-light-colored basic dye and a coupler capable of forming a color upon the contact with the dye, as the basic dye, 3-di(n-butyl)amino-6- methyl-7-phenylaminofluorane is used and, as the coupler, at least one of 4,4' isopropylidenephenol, 4-hydroxy-4'-isopropoxydiphenylsulfone and 2, 2-bis(4- hydroxyphenyl)-4-methylpentane is used. 150-250 pts.wt. of the coupler is used per 100 pts.wt. of the basic dye. When the coupler is less than 150 pts.wt., developed color density is markedly lowered and, when the coupler is more than 250 pts.wt., the fading preventing effect of a printed part under high temp. environment is lowered. This thermal recording medium is reduced in the fog of a blank part at high temp. even when a heat-meltable substance is together used as a sensitizer. |
