Abstract: Disclosed is a heat-sensitive recording material comprising a support and a heat-sensitive coloring layer formed on the support, wherein the heat-sensitive coloring layer contains either composite particles in which a leuco dye is contained in solid resin particles or microcapsules in which a leuco dye and a hydrophobic organic solvent are contained, the heat-sensitive coloring layer optionally contains other leuco dye which forms a color different from the color formed by the leuco dye contained in the composite particles or in the microcapsules, and the developer is N-p-toluenesulfonyl-N′-3-(p-toluenesulfonyloxy)phenylurea.

Abstract: Disclosed is a heat-sensitive recording material comprising a support and a heat-sensitive coloring layer formed on the support, wherein

Abstract: A thermosensitive recording material with a high resistance to fogging has a thermosensitive colored image-forming layer formed on a support and includes at least one colorless dye precursor, a color-developing agent and a binder, the dye precursor being contained in a plurality of fine solid composite particles prepared by dissolving a solute including the dye precursor in a solvent which includes a polymerization component including a polyvalent isocyanate compound; emulsifying the resultant solution in an aqueous medium; and subjecting the aqueous emulsion to a polymerization reaction to thereby form the fine solid composite particles in which the dye precursor is solid-dissolved in a solid thermoplastic resin matrix formed from a resultant polyurea or polyurethane polyurea resin.