THERMAL RECORDING MATERIAL

摘要

A thermal recording material which has excellent sensitivity in color development and gives an image having excellent storage stability. The recording material comprises a support and formed thereon a thermally color-developing layer comprising a leuco dye which is colorless or light-colored at ordinary temperature, at least one organic acid substance which upon heating reacts with the leuco dye to cause it to develop a color, and a sensitizer. The organic acid substance is at least one diphenyl sulfone derivative selected among 4-hydroxydiphenyl sulfone derivatives represented by general formula (1) or (2), 4,4'-dihydroxydiphenyl sulfone, and 2,4'-dihydroxydiphenyl sulfone, and the sensitizer is a 4-acylbiphenyl. In the formula (1), R1 represents alkyl, aralkyl, or aryl. In the formula (1), Y represents a divalent organic group, and n is an integer of 0 to 6.