| 摘要 |
PROBLEM TO BE SOLVED: To obtain a reversible color developing compsn. and a reversible heat-sensitive recording medium which holds stable color developing properties and color dissipating properties and can be adaptable to a wide range of utilization conditions and has high light resistance by incorporating a chroman compd. of a specified formula to a reversible heat-sensitive color developing compsn. SOLUTION: An electron donating color developing compd. and an electron accepting compd. are incorporated as main components to obtain a reversible heat-resistant color developing compsn. which can be in a relatively color- developed state and a color-dissipated state based on difference in heating temp. and/or cooling temp. after heating. In this reversible heat-resistant color developing compsn., a chroman compd. of formula I (wherein R1 is a hydrogen or a lower alkyl group and n is 1-3 and R2 is a hydrogen, an unsubstd., substd. alkyl group, a carboxylic acid, or its alkyl ester and R3 is a hydrogen or an alkyl group) is incorporated. This reversible heat-resistance compsn. exhibits especially high light resistance under color developing condition and stable color developing and dissipating characteristics under a wide range of environmental conditions. |
