Patent GB-1214302-A (GB)
Title: Photoelectropolymerization process
Inventor: LEVINOS STEVEN
IPC: C08F2/46
Filed: 1967-11-15
Abstract: 1,214,302. Photo-electropolymerization. GAF CORP. Nov.15, 1967 [Feb.17, 1967], No.51937/67. Addition to 1, 161, 803. Heading G2H [Also in Divisions C3 and H1] A photo-electropolymerization process for use in the production of polymer resists comprises placing (p) in layer of photo-conductive material in electrically conducting contact with (q) a layer comprising a polymerizable ethylenically unsaturated monomer, which is liquid or solid at ambient temperature, and a polymerization catalyst progenitor comprising a diazotized primary aromatic amine salt which upon electrolysis yields a polymerization catalyst, coated upon (r) an electrically conductive support; applying a unifrom electric p. d. across the layers (p) and (q), exposing the layer (p) to imagewise electromagnetic radiation having a wavelength within the ultraviolet and visible regions of the spectrum to increase the electrical conductivity thereof in the exposed areas in accordance with the imagewise variations in density of the radiation and cause current to flow through the layers (p) and (q) to the support (r) in accordance with the imagewise variations in conductivity of the exposed layer (p) and cause imagewise production of activated catalyst and thus imagewise polymerization of the monomer of layer (q), in accordance with the imagewise exposure of the layer (p). In the production of polymer resists, the process may comprise preparing a first element (I) by coating a transparent support (t) with a layer (s) of electrically conducting material and coating (s) with the layer (p), preparing a second element (II) by coating support (r) with layer (q), placing elements I and II together with layers (q) and (p) in electrically conducting contact, then effecting the photo-electropolymerization, separating elements I and II and removing the unpolymerized portions of the monomer layer (q). "Nesa"-coated glass is suitably as an electrically conducting layer and the photo-conductive layer may comprise zinc oxide, zinc sulphide, zinc cadmium sulphide, cadmium sulphide, which compounds may be activated in known manner, and also vacuum evaporated vitreous selenium. Polymerizable monomers specified are acrylamide, acrylonitrile, N-ethumolacrylamide, acrylic and methacrylic acid and salts and esters thereof, methacrylamide, vinyl esters of carboxylic acids, vinylpyrrolidone, acrylylpyrrolidone, vinyl ethers, butadiene and mixtures thereof; small amounts of crosslinking monomers may be present, e. g. methylenebisacrylamide, triallyl cyanurate, divinyl benzene, divinyl ketone and diglycol diacrylate. A natural or synthetic hydrophilic colloid carrier may be included in the monomer/catalyst composition, and also a humectant, e.g. a glycol or polyglycol; the composition is generally maintained at aph below 7. Image colouration can be augmented by inclusion of a suitable coupler material in the polymerizable coating, or by staining with black or coloured inks or dyestuffs, or by including a pigment to improve contrast. The process can be used to produce relief printing plates, negative working off-set plates, printing materials, image transfer materials, printing masks, photo-lithographic printing plates, lithographic cylinders, printing stencils and printed circuits.