| 摘要 |
PURPOSE:To improve the light fastness by reflecting external ultraviolet rays, by forming the coated layer containing hyperfine particulate titanium oxide on the surface of a thermal coloring layer. CONSTITUTION:The thermal coloring layer 14 coloring by heating is formed on the surface of a sheet base material 12. This thermal coloring layer 14 is formed by coating the mixture of, for instance, leuco dye, developer, and binding agent to be dried on the surface of the sheet base material 12. A protective layer 16 is formed on the surface of this thermal coloring layer 14. This protective layer 16 is formed by coating the mixture of, for instance, hyperfine particulate titanium oxide and binding agent to be dried on the surface of the thermal coloring layer 14. The hyperfine particulate titanium oxide in this protective layer 16 is for the purpose of reflecting external light (ultraviolet rays), and should preferably by not more than 0.5mum in particle size for the use. |
