| 摘要 |
PURPOSE:To enhance color formability, discoloration resistance and light fastness, by using oxide of an element belonging to the Group IVb of the Periodic Table as a color developer. CONSTITUTION:As a color developer for a leuco dye, at least one kind of oxide of an element belonging to the Group IVb of the Periodic Table such as TiO2 or ZrO2 is used. By this method, color development, discoloration resistance and light fastness are enhanced. Since the oxide of an element belonging to the Group IVb of the Periodic Table has high whiteness, a good image is obtained. For example, 30pts.wt. of TiO2 is added to 50pts.wt. of a 5% aqueous polyvinyl alcohol solution, and ground and dispersed to obtain a color developer dispersion. This color developer dispersion is applied to wood free paper to obtain a color developing sheet for the leuco dye. By this method, the color developer for the leuco dye excellent in color formability, discoloration resistance and light fastness and having high whiteness is obtained. |
