| 摘要 |
PURPOSE:To ensure favorable preservability in a high-temperature atmosphere and enable thermal recording with high sensitivity to be performed, by setting the eutectic temperature of a leuco dye, a color developer and a thermal sensitizer to be 75-100 deg.C and setting the weight fractions XL, XD, XS of the constituents in specified relations with the values XL*, XD*, XS* of the weight fractions for a eutectic composition. CONSTITUTION:The eutectic temperature of a leuco dye, a color developer and a thermal sensitizer incorporated in a thermal recording medium is 75-100 deg.C. The weight fractions XL, XD, XS of the three constituents used fulfill the relations of the formulas. For a eutectic composition X* of the three constituents, the weight fraction of the leuco dye A is XL* on a side AB, that of the color developer B is XD* on a side BC, and that of the sensitizer C is XS* on a side CA. When the composition of the three constituent is at the eutectic composition, all of the constituents are liquefied when the composition is heated to the eutectic temperature. When the composition in the shaded region in the figure, a sufficient thermal sensitivity can be obtained. |
