| 摘要 |
<p>A water-sensitive layer is produced by dissolving in a suitable solvent a hydrophobic resin and 1 to 90 per cent of a compatible copolymer of about one mol. of a vinyl compound with about one mol. of an ethenoid dicarboxylic acid or anhydride, coating the solution on a support, drying and then hydrolyzing with a base in the presence of moisture. The hydrophobic resin may be cellulose acetate, nitro-cellulose, ethyl cellulose, polyvinyl acetate, polyvinyl butyral, or polymethyl methacrylate and specified copolymers are those derived from maleic anhydride and methyl, isobutyl or 2-methoxyethyl vinyl ether, vinyl acetate or styrene. Suitable solvents are ethylene glycol monomethyl ether, cyclohexane, cyclohexanone, tetrahydrofuran, dioxane, acetone and methyl ethyl ketone. The bases used are moist ammonia gas, aqueous ammonia, caustic alkali, caustic potash, dimethylethanolamine and alkaline salts and the support may be of paper, glass, aluminium or zinc foil, fabric, wood, cellulose acetate, cellulose acetate butyrate, regenerated cellulose, nitrocellulose, polyvinyl alcohol or polymethyl methacrylate. The layers may be dyed with an aqueous solution of Methylene Blue. In example 10 triphenyl phosphate and methyl phthalyl ethyl glycollate are used as plasticizers.</p> |
