Patent GB-1234755-A (GB)
Title: Photographic film
Inventor: VAN PAESSCHEN AUGUST J
IPC: B32B33/00
Filed: 1967-09-28
Abstract: 1,234,755. Coated films. GEVAERT-AGFA N.V. 12 Aug., 1968 [28 Sept., 1967], No. 44114/67. Heading B2E. [Also in Divisions G2C and H1K] A sheet material comprises a hydrophobic film support having superposed therein in succession, (a) a layer which is directly adherent to the hydrophobic film support comprising a copolymer formed from 45 to 99.5% by weight of at least one of the chlorine-containing monomers, vinylidene chloride and vinyl chloride, from 0.5 to 10% by weight of an ethylenically unsaturated hydrophilic monomer, and from 0 to 54.5% by weight of at least one other copolymerisable ethylenically unsaturated monomer; and (b) a layer comprising in a ratio of 1:3 to 1:0.5 by weight of a mixture of gelatin and a copolymer of 30 to 70% by weight of butadiene with at least one copolymerisable ethylenically unsaturated monomer. A matting agent such as finely divided silica, a photo-sensitive semi-conductive organic or inorganic compound such as titanium dioxide or zinc oxide, or a photoconductive compound suited for use in electrophotography or an antistatic agent may be added to the mixture of gelatin and butadiene copolymer latex. A light-sensitive gelatino silver halide emulsion layer, a layer comprising a photo-sensitive semi-conductive substance or in successive order a layer comprising an electroconductive substance and a layer comprising a photo-conductive substance dispersed in an insulating binder may be deposited on the layer comprising a mixture of gelatin and butadiene copolymer latex. Hydrophobic support films mentioned are hydrophobic cellulose ester, e.g. cellulose acetate, cellulose aceto-butyrate and cellulose nitrate, linear polyesters such as polyethylene terephthalate, polystyrene or polymethacrylic acid esters. The treated sheet material may be used for transference thereto of a hydrophilic layer to produce a recording or reproduction system by transfer of another material or produced thereon from a liquid system. Particularly useful recording materials are provided by the sheet material having hydrophilic pigment coatings thereon, e.g. pigmented gelatin coating suited for the production of relief images, which are produced by means of a photohardening or photo-solubilizing reaction. The sheet material may be used as a wrapping material, particularly when having layers thereon adapted to accept printing, or as tracing film. Examples of suitable vinylidene chloride and vinyl chloride copolymers are given. They may be coated on the hydrophobic film base, e.g. by immersion, spraying, brushing, roller, doctor blade, air brush or wiping and may be applied to at least one side of a non- stretched film, a biaxially oriented film, or a film which has been stretched in only one direction, e.g. longitudinally whereafter the subbed film is stretched in a direction perpendicular thereto. The butadiene copolymer may comprise ethylenically unsaturated monomers such as acrylonitrile, styrene, acrylic acid esters, methacrylic acid esters and acrolien. Urea-formaldehyde or melamine-formaldehyde resins may be added to the butadiene copolymer layer to render the surface more resistant to writing and tracing operations. Both layer (b) and the hydrophilic layer when present may contain dissolved dyes, e.g. a dye that is bleachable, colour couplers, e.g. a colour coupler that is used in silver halide colour photography, developing nuclei suited in the production of silver images according to the silver halide complex diffusion transfer process.