| 摘要 |
PROBLEM TO BE SOLVED: To provide a reversible thermal recording medium holding stable color forming properties and color erasing properties, capable of corresponding to a wide range of a use condition and an environmental condition, capable of obtaining high speed erasing properties being especially practically important characteristics, capable of stably holding a printing recording state, layer in the contrast of a developed color state and an erased color state and capable of obtaining high visibility. SOLUTION: In a reversible thermal color forming compsn. utilizing the color forming reaction between an electron donating coupling compd. and an electron acceptive compd., as the electron acceptive compd. a 4-hydroxymandelic acid derivative represented by the formula (wherein R is a 6-22C alkyl group; X is a divalent group containing a hetero atom; and (n) is an integer of 2-12) is used. |
