Photopolymerisierbare Harzzubereitungen,wasserwaschbare Photopolymerisat-Druckplatten und ihre Herstellung

摘要

1,233,883. Photopolymerizable resin compositions. NIPPON PAINT CO. Ltd. 7 Jan., 1969 [22 Jan., 1968; 15 March, 1968], No. 942/69. Heading C3G. [Also in Division G2] A photopolymerizable resin composition consists of (1) 1À26 to 3À78 parts by weight of a monoester of a dihydric aliphatic alcohol with acrylic acid or methacrylic acid, (2) an aqueous solution of 1 part by weight of a partially hydrolysed polyvinyl acetate having a degree of hydrolysis of 95 to 60 mol. per cent and an average polymerization degree of 300 to 2000 or a methyl cellulose of an average polymerization degree of 160 having a hydropropoxy substituent, and (3) as a photopolymerization initiator, 1 to 5%, based on the weight of (1) and the polymer component in (2), of at least one uranyl salt, alone or together with 0À0072 to 0À72%, on the said basis, of azobisisobutyronitrile. A monofunctional acrylamide, e.g. acrylamide, methacrylamide or their N-methyl derivatives may be present in component (1) in which the ester may be beta-hydroxyethyl or -hydroxypropyl acrylate or methacrylate. Specified uranyl salts are the nitrate, acetate, sulphate, phosphate and dibutyl phosphate. In the examples, the resin compositions are aqueous solutions containing (a) partially hydrolysed polyvinylacetate and (i) beta-hydroxyethyl acrylate, or methacrylate, or beta-hydroxypropyl methacrylate, or a mixture of beta-hydroxyethyl methacrylate and acrylamide, and uranyl nitrate or (ii) beta-hydroxyethylmethacrylate, uranyl nitrate and uranyl sulphate or azobisdiisobutyronitrile, or (b) methyl cellulose, beta-hydroxyethyl methacrylate and uranyl nitrate. The compositions are used in the production of photopolymerizable resin sheets and printing plates (see Division G2), which are exposed to U.V. light.