THERMAL RECORDING MATERIAL

PURPOSE:To improve the light fastness and humidity resistance of a developed color image by forming a thermal recording material by providing a thermal color forming layer containing a specific phthalide compound as a color former and a specific zinc compound as a developer on a substrate. CONSTITUTION:A predetermined amount of a divinylphthalide compound represented by formula I (wherein R and R are an alkyl groups and X and X are H or an alkyl groups), a predetermined amount of a fluorophthalide compound represented by formula II (wherein R -R are an alkyl group, a cycloalkyl group or an alkenyl group) and a predetermined amount of a zinc salt compound represented by formula III (wherein X and X are H or an alkyl group) are ground to prepare a coating solution as an aqueous dispersion. This coating solution is applied to a paper or a plastic film and dried to form a thermal recording layer to a prepare a thermal recording material.