| 摘要 |
PURPOSE:To esp. enhance the photosensitivity of a copying material and obtain a black image by placing a photosensitive and thermosensitive layer containing an organic tellurium compound, a photoreducing agent, a thiourea derivative and a binder on a support. CONSTITUTION:1pt.wt. of an organic tellurium compound, 0.1-10 parts of a photoreducing agent such as naphthoquinone which accepts H2 from a hydrogen- containing compound and becomes a reducing agent by the action of light, 1-10 parts of a thiourea derivative in which alkyl, aryl, etc. have been substituted for H, and 1-10 parts of a binder such as ethylcellulose are uniformly dispersed in a solvent, coated onto a substrate such as a polyester film, and dried to form a photosensitive and thermosensitive layer. This photoreceptor is imagewise exposed and heat developed to obtain a clear black image. The thiourea derivative facilitates conversion of the photoreducing agent into a reducing agent, so much tellurium is liberated from the tellurium compound, resulting in raised density. |
