| 摘要 |
PURPOSE:To provide a lithographic plate with a high printing resistance free from stain of ground and missing of characters which maintains high printability for a long time by arranging a gelatin-containing layer containing a photographic gelatin and a low molecular gelatin on a supporting body. CONSTITUTION:An undercoat layer containing 100pts.wt. of a photographic gelatin with an average molecular weight of 70,000-150,000 and 3-30pts.wt. of a low molecular weight gelatin with an average molecular weight of 3,000-30,000, a silver halide emulsion layer, an intermediate layer and a physical core layer are arranged on a supporting body such as PE cover paper and aluminum plate. After the image exposure to light, the lithographic plate is treated with an alkali developer such as the one for photographic silver diffusion transfer and then subjected to a neutralizer, a fixing liquid, an oil desensitizer and a humidifying liquid or the like as required for plate making and printing treatments. |
