REVERSIBLE HEAT-SENSITIVE RECORDING MEDIUM

PROBLEM TO BE SOLVED: To provide a reversible heat-sensitive recording medium excellent in film strength giving a good color optical density in erasing-printing after storage for a long period under a high-temperature and high-humidity environment.SOLUTION: A reversible heat-sensitive recording medium includes, on a substrate, a reversible heat-sensitive recording layer containing an ordinarily colorless or pale-colored dye precursor, and a reversible developer which forms relatively a colored state and an erased state by a difference in heating temperatures and/or cooling rates after heating. The reversible heat sensitive recording layer contains at least polyvinyl butyral and an isocyanate compound as binder species. A weight average molecular weight of the polyvinyl butyral is not less than 50,000, and a total unit ratio of hydroxyl groups and acetic acid groups to butyral groups of the polyvinyl butyral is 30-70 mass%.