| 摘要 |
PROBLEM TO BE SOLVED: To enhance color developing sensitivity by incorporating a dihydroxydiphenylsulfone compound represented by specific structural formula as an organic developer in a heat-sensitive color developing layer, and incorporating a saturated fatty and monoamide represented by another specific structural formula of a specific ratio with respect to the developer in the layer. SOLUTION: At least one type of a dihydroxydiphenylsulfone compound represented by formula I as an organic developer and at least one type of a saturated fatty acid monoamide represented by formula of 1.5 to 5 pts. with respect to 1 pt. of the developer are contained in a heat-sensitive color developing layer, wherein, in formula I, R1, R2 are each a 1-8C alkyl group, alkenyl group or halogen atom, and a, b are each an integer of 0 to 3, and, in formula II, R3 is a 11-21C alkyl group. According to this constitution, its color developing sensitivity is very enhanced, and its heat resistance is upgraded. Further, powder- coating or stability of white paper for a long-term storage becomes a sufficiently practically using level. |
