HEAT-SENSITIVE RECORDING PAPER

PURPOSE:To obtain heat-sensitive recording paper which can form clear color at a low temperature, by incorporating a color-forming substance and 4-butoxy- 4'- hydroxydiphenyl sulfone. CONSTITUTION:A normally colorless or light-colored color-forming substance which can form color by reacting with a phenol compound, such as Crystal Violet lactone or benzo-beta-naphthospiropyran, and 4-butoxy-4'-hydroxydiphenyl sulfone of the formula are crushed in water or in an organic solvent with a ball mill, a sand grinder, or the like, together with, if necessary, a surface active agent, a binding agent, or a dispersing agent, applied on a support and dried, to obtain heat-sensitive recording paper. By a combination of the color-forming substance and the specified phenol compound described above, clear color formation can be performed even at a temperature of 90-120 deg.C which is lower than the conventional one.