PURPOSE: To provide a heat-sensitive recording medium high in brightness and excellent in adaptivity to high-speed recording, wherein a specified heat-fusible substance having a melting point in a specified range is incorporated in a heat- sensitive color forming layer comprising a basic dye and a color forming agent as main constituents.
CONSTITUTION: In a heat-sensitive recording medium utilizing a color forming reaction between a colorless or light-colored basic dye [for example, 3-(N- cyclohexyl-N-methylamino)-6-methyl-7-anilinofluoran] and a color reaction agent (for example, 4,4'-isopropylidenediphenol) capable of performing a color reaction when being brought into contact with the dye, at least one of heat-fusible substances of formulas I WVII (wherein each of R1WR8 is phenyl, benzyl, tolyl or halogen-substituted one thereof) having a melting point of 75W145°C, preferably 80W140°C (e.g., benzyl, dimetyl benzyl or benzyl phenyl diketone, p- phenyl naphthyl ketone) is incorporated in the heat-sensitive color forming layer, preferably in a quantity of 50W500pts.wt. per 100pts.wt. of the color reaction agent.
HAYASHI RIYUUZOU
ARAI NAOTO
OEDA YOSHITAKA
