| 摘要 |
PURPOSE:To allow an image to disappear due to aging, by adding a mercapto compound to a diazo compound. CONSTITUTION:A photosensitive layer consisting essentially of a diazo compound and a mercapto compound directly or with a precoat layer between on a support. As said mercapto compound, alkylmercaptan, hydroxyalkylmercaptan, alpha-methylmercaptoethylamine, thioacetic acid, thiobenzoic acid, thiophenol, or the like are embodied, and it is used by 0.01-5mol per mole of diazo compound. Use of <=0.01mol mercapto compound reduces a decoloring effect, and use of >=5mol causes it to react with the diazo compound and to precipitate, and remarkably lengthens an image disappearance time, thus permitting the obtained diazo copying material to be visualized with alikali because of a one-component type, and the disappearance time to be controlled by the kind and amount of the mercapto compound. |
