HEAT-SENSITIVE RECORDING COMPOSITION

PURPOSE:To provide a composition excellent in light and solvent resistance, and developing a color of royal purple, comprising a reaction product between acylated leucomethylene blue (acid-addition salt) and a non-complexed hexavalent Mo compound. CONSTITUTION:An acylated leucomethylene blue or an acid-addition salt (e.g. 3, 7-bis (dimethylamino)-benzoly 10-phenothiazine) thereof and a non-complexed hexavolant Mo compound (e.g. CaMoO4) are reacted in a solution containing mineral acid at a room temperature to obtain a composition for thermosensitive recording comprising molybdic acid salt of the acylated leucomethylene blue having the formula (wherein A represents acylated leucomethylene blue and m and n are 1-7). The composition thus obtained is dispersed in water or an organic solvent containing a polymer binding agent, applied on a sheet-shaped material, and dried at a low temperature to form a heat-sensitive recording layer.