Patent ID: 8202821

Claim:
A thermal recording material comprising a support and a thermal recording layer comprising a colorless or pale basic leucodye and a developer to develop color of the basic leucodye, wherein the aforementioned developer comprises a first developer which is a condensate or condensed composition represented by the following formula (I) and a second developer other than the first developer, wherein the second developer is at least one kind selected from the group consisting of bisphenol A, 4,4′-dihydroxydiphenylsulfone, 4-hydroxy-4′-n-propoxydiphenylsulfone, 2,4′-dihydroxydiphenylsulfone, 4-hydroxy-4′-allyloxydiphenylsulfone, and bis(3-allyl-4-hydroxyphenyl)sulfone, and the proportion of the first developer to the total amount of the developers is not less than 5 wt % and less than 40 wt %: wherein R is a halogen atom, a hydroxyl group, a lower alkyl group, an alkoxyl group, a cyano group, a nitro group, an aryl group or an aralkyl group, R in the number of m may be the same or different, m is an integer of 0 to 3, n is an integer of 0 to 3, and X and Y are each a hydrogen atom, an alkyl group or an aryl group.