US Patent 7384891 Thermal recording medium

Provided is a thermally sensitive recording medium which exhibits high recording sensitivity, high heat resistance of ground color part and excellent preserving stability of images. A thermally sensitive recording medium, comprising a thermally sensitive recording layer containing a colorless or pale colored basic colorless dye and an organic color developing agent as main components on a substrate, wherein said thermally sensitive recording layer contains at least one compound represented by general formula (1) and contains at least one compound selected from the group consisting of 3-{[(phenylamino)carbonyl]amino}benzensulfoneamide represented by formula (2), an ureaurethane compound represented by formula (3) and a copolymer of glysidilmethacrylate and vinyl monomer (average molecular weight is 9000-11000, epoxy equivalent is 300-600 and melting point is 110° C. or less) as a stabilizer.