Reversible multi-color thermal recording medium

摘要

To provide a reversible multi-color thermal recording medium or a reversible multi-color optical recording medium which uses novel urea and thiourea derivatives and has excellent heat resistance. A reversible multi-color thermal recording medium having an irreversible thermal composition containing a colorless or pale basic achromatic dye and an organic color developer as main components and a reversible thermal composition containing a colorless or pale basic achromatic dye and an organic color developer as main components laminated on a support, the organic color developer contained in the irreversible thermal composition being an irreversible heat-resistant color developer and the organic color developer contained in the reversible thermal composition being a reversible heat-resistant color developer.