| 摘要 |
PROBLEM TO BE SOLVED: To obtain a thermosensible recording material decoloring spontaneously by combining 4-hydroxybenzoic acid ester with fluorene leuco dye. SOLUTION: Developer is 4-hydroxybenzoic and ester expressed by formula I, and a dye precursor is fluorene leuco dye expressed by formula II. An image rate of the residual image is 60% or more 20 hours later after printing, and an image rate of the residual image is 60% or less 24 hours later after printing. Herein, R represents a lower alkyl group of unsubstituted or substituted 1-7C or benzil group. R1 -R6 represent respectively H, an alkyl group of 1-18C, a cycloalkyl group of 3-7C, a lower alkoxyl group of 1-7C, a phenyl group, and a benzil group. R7 , R8 , and R9 represent respectively H, a halogen atom, a lower alkyl group of 1-7C, and an alkoxy group of 1-7C. |
