THERMAL RECORDING MATERIAL

PROBLEM TO BE SOLVED: To improve preservative property of coloring images in a visible part and a near infrared part by forming a thermal recording layer of a thermal recording material out of a dye precursor, a developer consisting of a salicylic acid derivative shown by a specified formula or its metallic salt, and an aromatic isocyanate compound and the like. SOLUTION: In a thermal recording material having a thermal recording layer which colors with heat and is arranged on a support body, a dye precursor, a developer consisting of a salicylic acid derivative shown by the general formula of its metallic salt, an aromatic isocyanate compound, and an aromatic imino compound are added to the thermal recording layer. As the dye precursor, a 3, 6-bis(dimethyl amino) fluorene-9-spiro-3'-(6'-dimethyl amino phthalide) or the like is used. In the formula, X1 and X2 are each a hydrogen atom, an alkyl group, an aralkyl group, an aryl group or a halogen atom, and R is an alkyl group, an alkenyl group, an aralkyl group or an aryl group.