| 摘要 |
PURPOSE:To manufacture a lithographic plate causing no ground stain and being superior in printing resistance, by contacting a specified sulfur containing organic compound and an oxidant with a silver image receiving ink. CONSTITUTION:In the lithographic plate using a silver halide emulsion and a silver image made ink-receptive, compound (a) having a mercapto group or thionyl group and a hydrophilic group in the molecule, such as 2-mercaptoethanol, thioglycolic acid, or 2-mercaptoethylsulfonic acid; and the second metal ions, such as Cu<+2> or Au<+3>, and halogen or halogen acid, and the like oxidant (b) are contacted with a silver image formed for receiving ink. The above compounds (a), (b) are added to a photomechanical processing fluid or a processing solution in a printing process (compound (a) may be added to a photosensitive layer). And it is desirable that compound (a) is contacted with the silver image before compound (b). |
