摘要 |
PURPOSE:To enable processing of planographic printing plates of both of a negative type and positive type by one kind of developer and one unit of automatic developing machine. CONSTITUTION:This photosensitive compsn. contains a polyester resin having a phenolic hydroxyl group in the side chains and a negative type photosensitive compd. on a base. This photosensitive planographic printing plate has a photosensitive layer consisting of this compsn. This process for production of the planographic printing plate consists in subjecting this planographic printing plate to image exposing, then to developing with the aq. alkaline developer contg. substantially no org. solvents. The negative type photosensitive planographic printing plate is developed by the aq. alkaline soln. contg. substantially no org. solvents, by which the planographic printing plate is obtd. without generating scum and sludge, etc., in the developer. Since the developer does not contain the org. solvent, there are no problems in sanitation. such as toxicity and smells at the time of work, and no problems in safety such as fires and gas explosion. In addition, the negative type planographic printing plate is produced by the processing similar to the processing for the conventional positive type photosensitive planographic printing plate. |