| 摘要 |
PURPOSE:To obtain a thermal recording material which is excellent for light fastness by a method wherein specific nickel benzophenone sulfonate hydrate is contained as a light resisting agent in a thermal recording material composed of a coloring agent which is colorless or light color at ordinary temperature and a developer. CONSTITUTION:A thermal recording material is composed by incorporating nickel benzophenone sulfonate hydrate represented by the general formula (I) as a light resisting agent in the thermal recording material consisting of a coloring agent which is colorless or light color at room temperature and a developer. In nickel benzophenone sulfonate hydrate represented by the general formula (I), R<1> represents hydrogen, alkyl radical, or benzyl radical. When it is alkyl radical, the number of carbon atom should preferably by 1 to 10. R<2> represents hydrogen or alkyl radical. When it is alkyl radical, the number of carbon atom should preferably be 1 to 4. Further, R<3> represents hydrogen or hydroxyl radical. As a preferable concrete example of nickel benzophenone sulfonate hydrate, for instance, 2,4-dihydroxy benzophenone-5-nickel sulfonate or the like are exemplified. |
