DEVELOPING METHOD

PURPOSE:To prevent stains on a background without making treatment for eliminating affinity to fat and grease, by developing a printing plate having a photosensitive layer contg. a resin having tertiary N with an acidic developing soln. CONSTITUTION:A resin usable in this invention is [ I ] an amine-modified epoxy resin obtained by reacting an epoxy resinwith primary or secondary amine, or when needed, with an epoxy-contg. acrylic monomer, and [II] a polymer or copolymer having repeating units each represented by general formula, or a copolymer with another vinyl monomer, etc. A printing plate used in this inventuon can be manufactured by dissolving a photosensitive diazo compd. and said resin in a proper solvent, and coating a support with the prepared photosensitive resin compositon, and drying it. In the formula, R1 is H or methyl, and R3, R4 are each alkyl, aryl, alkaryl, aralkyl, or one of those substd. by alcoholic OH or halogen, and R3 and R4 may combine with each other to form a heterocyclic group.