| 摘要 |
PROBLEM TO BE SOLVED: To obtain a thermal recording sheet having excellent coloring sensitivity by adding a urea (thiourea) derivative in a thermal coloring layer as an organic developer and adding a fixed rate of a diphenyl sulfone compound in the organic developer as a sensitizer. SOLUTION: On a support body, a thermal coloring layer which contains a colorless or light color basis colorless dye and an organic developer as main components is provided. The thermal coloring layer contains a compound to be expressed by formula I or formula II as an organic developer, and contains 0.01-2 pts. of diphenyl sulfone compound to be expressed by formula III based on 1 pts. of organic developer as a sensitizer. (A) represents a hydrogen, a 1-4C alkyl group, R1 -R3 represent a hydregen atom, a 1-4C alkyl group, (Y) represents a sulfur atom or an oxygen atom, (B) represents a hydrogen, a 1-4C alkyl group, (X) represents a 1-6C alkyl group, a 1-6C alkoxy group, and (m) is an integer of 0-2. Thus, a thermal recording sheet having excellent coloring sensitivity can be obtained. |
