| 摘要 |
PURPOSE:To provide a thermal recording material having a white ground and a high dynamic color forming sensitivity, by a method wherein a leuco dye and a thermoplastic substance having a melting point of 70-130 deg.C are melted together, and the leuco dye is microcrystallized by a maturing treatment. CONSTITUTION:A leuco dye and a thermoplastic substance having a melting point of 70-130 deg.C are mixed with each other, and the mixture is treated by, for example, a method wherein the mixture is melted by heating, and the molten mixture is cooled to obtain a co-melted and solidified mixture or a method wherein the molten mixture is emulsified or dispersed in hot water containing a protective colloid, a surfactant or the like, followed by cooling to obtain a dispersed liquid of the co-melted and solidified mixture, and then a protective colloid, a surfactant or the like is added to the co-melted and solidified mixture or the dispersed liquid thereof, followed by dispersely pulverized to a desired particle diameter in an aqueous system. The dispersed liquid of the co-melted and solidified mixture thus obtained is matured at a fixed temperature of 15-50 deg.C to microcrystallize the amorphous leuco dye, thereby obtaining a heat- sensitive coating liquid. By using the coating liquid, a thermal recording material can be obtained which is free of fogging and having a white ground. |
