摘要 |
PURPOSE:To obtain a thermal recording material which is high in whiteness and excellent in high speed recording suitability by a method wherein a thermal coloring layer contains a specific biphenyl ether compound. CONSTITUTION:A thermal recording material has a thermal coloring layer containing a colorless or light colored dye precursor and a developer which colors it by reacting with the dye precursor under heating on, at least, one surface of a sheet like substrate. Then, this thermal coloring layer contains further a biphenyl ether compound of the formula (1). In the formula, however, R1, R2 represent a hydrogen atom, a lower alkyl radical, a lower alkoxy radical, or a halogen atom, and both are not simultaneously the hydrogen atoms. Since this compound sensitizer is low viscosity under a fused state and has appropriate compatibility with the dye precursor and the developer, coloring sensitivity of the thermal coloring layer is improved. Further, the reason why whiteness of the thermal coloring layer is not decreased is that it is difficult to be dissolved in water. Furthermore the reason why a phenomenon of deteriorating quality of a recording image such as whitening or the like is little is that it is low in sublimation. |