Patent GB-1443757-A (GB)
Title: Films or sheets for use in chelate colour printing
IPC: B41M5/132
Filed: 1973-11-08
Abstract: 1443757 Coated products SEKISUI KAGAKU KOGYO KK and TOMOEGAWA PAPER CO Ltd 8 Nov 1973 [9 Nov 1972 (2)] 51926/73 Heading B2E A film or sheet for chelate colour printing comprises a substrate of a thermoplastic resin having a porous surface layer and on such porous layer a chelate colour printing layer comprising either (a) 0.2 Î 10<SP>-4</SP> to 0.1 Î 10<SP>-1</SP> mols/m<SP>2</SP> of at least one inorganic compound containing at least of the atoms trivalent ion, tetravalent and pentavalent vanadium, tetravalent titanium and hexavalent molybdenum and tungsten or (b) 0.3 X 10<SP>-4</SP> to 0.2 Î 10<SP>-1</SP> mol/m<SP>2</SP> of at least one organic compound capable of forming a coloured chelate compound with at least one of the said atoms. Suitable thermoplastic resins of which the substrate may be formed are polyolefins, polystyrene, polyvinyl chloride, polyimides, acrylic resins, polyethers, polyesters, polycarbonates, polyester-amides, polyester-ethers, vinylidene chloride resins and polytetramethylene-hexamethylene. They may include plasticisers, colouring agents, fillers, heat and light stabilisers, surface active agents, antistatic agents and lubricants. Suitably the film has a thickness of 0.5 to 3 mm. The porous surface layer may be obtained 'by contacting the film or sheet with a liquid capable of dissolving or swelling the thermoplastic resin sufficiently to render it porous and thereafter removing the liquid. A film having a suitably porous surface layer may be obtained by cooling a mixture of 100 parts of the thermoplastic resin, 1-100 parts of rubbery thermoplastic polymer at 1-500 parts of a finely divided inorganic substance and stretching the resultant film or sheet to at least 1.5 times its original length in at least one direction in order to form a thermosheet having a porous, multi-layered surface structure. Suitable rubbery polymer materials are natural rubber, polyisoprene rubber, polybutadiene rubber, polypropylene oxide, polydhloroprene rubber, polyisobutylene, rubbery isobutylene/isoprene copolymer rubbers, rubbery styrene/butadiene copolymer rubbers, acrylic rubbers such as acrylonitrile/butadiene copolymers, rubbery chlorosulphonated polyethylene, homopolymers and copolymers of acrylic acid esters, silicone rubber, urethane rubber, polysulphide rubber, fluorine rubbers, chloropolyethylene, chlorinated rubbers, hydrochloric acid rubbers, ethylene/vinyl acetate copolymer rubber and rubbery chlorinated polyethylene. Numerous suitable finely divided materials both inorganic and organic are listed. Suitable materials for the chelate printing layer are also specified. The printing layer may be formed by bringing a porous surface layer of the thermoplastic resin substrate into contact with a solution of the compound by dipping or spraying. Alternatively the compound may be applied as a uniform dispersion. Preferably, in the chelate printing layer, a fine powdery substance insoluble in the solvent, is present in the layer as well as a binder. Suitable binders are polyvinyl alcohol, polyvinyl acetate, vinyl acetate/acrylic ester copolymers, ethylene/vinyl acetate copolymers, polyvinyl chloride, polyacrylate resins, polyester resins, styrene/maleic acid copolymers, cellulose derivatives, rubbery polymers such as styrene/butadiene copolymers, starch, casein and gelatine.