| abstract |
1,235,281. Photo-lithographic material. HOWSON ALGRAPHY Ltd. May 17, 1968 [Feb. 18, 1967], No.37135/66. Heading G2C. Pre-sensitized photo-lithographic plate for the deep-etch process comprises a support coated with a layer of (1) a diazo or azido compound in (2) a water-soluble co-polymer of (a) acrylamide and (b) up to 30 wt. % of acrylic acid, methacrylic acid, an ester of a C 4 alcohol and acrylic or methacrylic acid, acrylonitrile, methacrylonitrile, N-substituted acrylamide, N-substituted methacrylamide and/or vinyl pyrrolidone. Preferably the support is A1 or A1 alloy anodized in H 2 SO 4 , or H 3 PO 4 , (1) is diazodiphenylamine sulphate, its condensation product with paraformaldehyde, the ZnCl 2 salt of this condensation product or 4, 4<SP>1</SP>- diazidostilbene -2, 2<SP>1</SP> -disulphonic acid, and the layer contains a substance which absorbs 2700-4000 A radiation (e. g. Yellow dye Auramine, chrysoidine or tartrazine). |