THERMAL RECORDING PAPER

PURPOSE:To enable to obtain excellent heat response characteristics and high sensitivity, by using a specified 1,4-dihydroxynaphthalene monoether as a color developer in combination with a colorless or light-colored color forming dye. CONSTITUTION:A 1,4-dihydroxynaphthalene derivative of the formula, is used as a color developer for developing the color of a normally colorless or light- colored dye when being heated, together with the dye. Accordingly, a thermal recording paper having excellent heat response characteristics and high sensitivity can be obtained. The derivative has excellent heat response characteristics, and provides a high-sensitivity thermal recording paper capable of forming clear developed color images even with low energy. In addition to the above components, the recording material may further comprise calcium carbonate, kaolin, clay, talc, diatom earth or a metallic salt of fatty acid such as zonc stearate and calcium stearate, for the purpose of enhancing the brightness and writing properties of a recording layer or preventing sticking.