| 摘要 |
PURPOSE:To obtain a clear color picture highly contrasted to the nonlettering part by incorporating calcium carbonate having a 0.15mu average particle diameter and a particle size distribution 0.1-2.0mu in a heat-sensitive color developing layer. CONSTITUTION:In the heat-sensitive color developing layer formed by combining colorless or pale colored leucodye as a color former and acidic material which develops leucodye thermally as a developer 1-10wt. part of calcium carbonate having a 0.15mu average particle diameter and a particle size distribution 0.1-2.0mu is incorporated to 1wt. part of the color former. When calcium carbonate having a 0.15mu average particle diameter and a particle size distribution 0.1-2.0mu is used, dispersion of the heat-sensitive coating liquid, sticking, whiteness, retouch are improved and even during longtime, all over lettering a clear and thick color picture highly contrasted to the nonlettering part is obtained. |
