A method for suppression of combustion in front of turns in the case of such of ozone-containing oxygen with ozone per after recrystallization products of the unsaturated aliphatic preferential aet monocarbonsaeuren or of the a ≠ - pinene films containing

摘要

864,033. Light sensitive composition for photomechanical procedure. HARRIS-INTERTYPE CORPORATION. July 9,1957 (Aug. 21, 1956], No. 21710/57. Class 98(2) A water-soluble linear copolymer of an alkyl vinyl ether and a maleic anhydride compound includes an ingredient providing hexavalent chromium in solution. The alkyl radical may be methyl, ethyl or propyl and the reactant compound maleic anhydride itself or this treated with ammonia, alkali hydroxide, an alcohol or a water soluble amine. The composition may be coated, exposed and processed to make lithographic plates in the manner used in gumbichromate procedure, but the coatings do not deteriorate to the same extent and plates prepared therefrom are regarded as "presensitised". In Example 1 a prepared aluminium plate is whirl-coated with aqueous methyl vinyl ether/ maleic anhydride copolymer containing ammonium dichromate, dried, exposed behind a negative for two to three minutes, treated with a polyvinyl chloride or acetate lacquer, developed in water, desensitised and gummed and is then ready for mounting in a press. Example 2 is the same except that maleic anhydride half amide is used in the copolymer and the lacquer treatment is omitted. Uses as for photoengraving procedure and stencil production are referred to as well as lithographic applications.