DEVELOPING SOLUTION WHICH CAN MAKE COMMON PROCESSING OF NEGATIVE TYPE AND POSITIVE TYPE PHOTOSENSITIVE LITHOGRAPHIC PRINTING PLATE AND DEVELOPING PROCESS METHOD USING SAID SOLUTION

摘要

PURPOSE:To form a developing soln. which can make common developing process of a negative type PS plate and positive type PS plate by using an aq. alkaline soln. contg. an alkali metal silicate and amphoteric surface active agent or anionic surface active agent as the essential component for the developing soln. and preparing said soln. so as not to contain an org. solvent. CONSTITUTION:This developing soln. consists essentially of the aq. alkaline soln. contg. 1-10wt% alkali metal silicate expressed by the formula xSiO2.yM2O (M is an alkali metal, x, y respectively denote molar number of SiO2 and M2O, x/y are 0.8-2.0) and 0.01-5wt% amphoteric surface active agent or anionic surface active agent and having =11.5pH and contains substantially no org. solvent. The development is defective if the content of the alkali metal silicate is 1% and the development is defective or excessive according to the kind of the PS plate if the content thereof exceeds 10%. The excessive development or the dissolution of the image is caused if the value of x/y is 0.8 and the development is defective if the value exceeds 2.0. The development is defective if the pH of the developing soln. is 1.5.