| 摘要 |
PURPOSE:To obtain a diazo copying material capable of forming a high density image and having superior pencil writability and rubber erasability by combinedly blending silica fine particles of low apparent specific gravity and silica fine particles of high apparent specific gravity into a photosensitive layer containing a diazonium compound. CONSTITUTION:Silica particles of 5mu or less in average particle size and 0.3 or more in apparent specific gravity, e.g. Syloid 65 of Fuji Davison Kagaku KK and silica particles of 5mu or less in average particle size and 0.2 or less in apparent specific gravity e.g. Aerosil 130 of Nippon Aerosil KK are mixed in a ratio of about 1-20:50 by wt. This mixture is added to a photosensitive layer based on a diazonium compound and an acid stabilizer. The layer may contain a coupling component. The thickness of the layer formed on a support is preferably about 5-20mu. |
