| 摘要 |
PURPOSE:To obtain a color copy in a simple and easy way, by providing two thermal color forming layers each containing diazonium salt existing in different forms. CONSTITUTION:On a substrate, a first thermal color forming layer containing a diazonium salt, being in compatibility with a binder resin, and a coupler and a second thermal color forming layer containing a diazonium salt, existing in a binder resin in the form of fine particle, and a coupler are laminated in order. The diazonium salts in the first and second layers are selected so as to be photolyzed by the lights having just or nearly the same wave range and the diazonium salts and couplers are selected so as to form colors with different hues in the first and second layers when being heated. A barrier layer can be provided between the two thermal color forming layers if necessary to prevent the two color forming layers from being mixed during thermal color forming. As the substrate, a wood free paper, a coated paper, an art paper, a synthetic resin film, a woven cloth sheet, a metal, a glass, etc. can be used. In this manner, a substantially perfect fixing can be carried out for a short time by varying the exposure time with use of a given light source. |
