| 摘要 |
PROBLEM TO BE SOLVED: To enhance character reading aptitude within a predetermined wavelength region by using one kind of a fluorane derivative represented by a formula as a basic dye contained in the recording layer of a thermal recording material and adding specific phosphate or one kind of a metal salt thereof to the recording layer. SOLUTION: In a thermal recording material excellent in optical reading aptitude, for example, within a wavelength region of 650-700nm and obtained by providing basic dye and a coupler on a support, as the basic dye, one kind of a fluorane derivative represented by formula is used and 2,2'-methylenebis (4,6-di-tert-butylphenyl)phosphate or one kind of a metal salt thereof is added to the recording layer. In the formula, R1 and R2 are a 1-6C alkyl group and R3 and R4 are a 1-4C alkyl group. By this constitution, an excellent thermal recording material reduced in lowering of optical reading aptitude within a wavelength region of 650-700nm even if exposed to high temp. and high humidity conditions or light for a long time is obtained. |
