Patent ID: 7078365

Claim:
A thermosensitive recording material, comprising a substrate and a thermosensitive recording layer on said substrate, said thermosensitive recording layer comprising a leuco dye, at least two sensitizers and a color developer for inducing color formation in said leuco dye upon application of heat thereto, wherein said at least two sensitizers comprise 4-hydroxy-4′-allyloxy diphenylsulfone and 4,4′-diallyloxy diphenylsulfone, and wherein the color developer is at least one member selected from the group consisting of diphenylsulfone derivatives represented by the following formula (I) wherein, X and Y are each, independently, a saturated or unsaturated linear or branched hydrocarbon group having 1–12 carbon atoms, which can optionally possess an ether bond, or a group of formula II or III wherein, R7 indicates a methylene group or an ethylene group, T indicates a hydrogen atom or an alkyl group having 1–4 carbon atoms, R1–R6 each, independently, indicate a halogen atom, an alkyl group having 1–6 carbon atoms, or an alkenyl group having 2–6 carbon atoms, each of m, n, p, q, r, and t independently indicate an integer of from 0 to 4 and when 2 or larger, R1–R6 can be different, and a is an integer of from 0 to 10.