| 摘要 |
PROBLEM TO BE SOLVED: To provide a thermal recording material which shows outstanding thermal responsiveness, image conservation stability, especially superb plasticizer resistance. SOLUTION: In the thermal recording material composed of a thermal color development layer, containing a leuco dye which is colorless or pale-colored at normal temperatures and an organic acid substance which makes the leuco dye thermally develop a color through a chemical reaction with the latter, which is formed on a support, a 4,4'-dihydroxydiphenyl sulfone/a 2,4'- dihydroxydiphenyl sulfone in a weight ratio of 35/65 or more, and a 4,4'- dihydroxydiphenyl sulfone and a 2,4'-dihydroxydiphenyl sulfone in a weight ratio of 50/50 below are used as the organic acid substances in the form of a mixture. A thermally soluble organic compound such as a p-benzylbiphenyl can be added to the thermal color development layer. |
