To obtain a thermal recording material in which both reduction of sticking and fog of a ground and holding of image storing properties can be consistent with each other.
In the thermal recording material having a thermal color developing layer comprising a leuco dye and a color developing agent as main components on a substrate, as the color developing agent, a phenolic compound with a sulfonyl group in a molecule or an oligomer composition obtained by polycondensation reaction of a polyfunctional isocyanate compound of trivalence or higher expressed by formula (I) with an aromatic amine expressed by formula (II) is used, and in addition, as the thermal color developing layer has a petaloid porous structure and comprises a calcium phosphate compound with an oil absorption of ≥150 ml/100 g. In formula (I), X is a group of trivalence or higher; (a) is an integer of ≥3; (b) and (c) are each an integer of 0-5 (b+c=1-5); Z is a hydrogen atom, an alkyl group, an allyl group or an aryl group; in a case of the aryl group, a structure of a condensed ring is also included; and (d) is an integer of 0-4 (b+c+d=1-5).
MORITA MITSUNOBU
NARUSE MITSURU
KAJIKAWA TAKESHI
IKEDA TOSHIAKI
Norio Kagami
Hidetake Komatsu
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