Patent GB-1497924-A (GB)
Title: Multilayered material of low gas permeability
IPC: B65D81/28
Filed: 1975-02-27
Abstract: 1497924 Pullulan containing laminates SUMITOMO CHEMICAL CO Ltd and HAYASHIBARA BIOCHEMICAL LABORATORIES Inc 27 Feb 1975 [1 March 1974] 8269/75 Heading B5N [Also in Division B2] A multi-layered material comprises at least one layer comprising pullulan and a further layer comprising a plastics material; paper or aluminium foil. The pullulan may be unmodified and water soluble or cross-linked and insolubulized either by a cross-linking agent, e.g. formaldehyde, acetaldehyde, butylaldehyde, glyoxal, an epoxy resin, a diisocyanate, dimethylolurea or dimethylol ethylene urea or exposure to light after the addition thereto of a bichromate; alternatively, it may be insolubilized by mixing an aqueous solution thereof with a monofunctional monomer, e.g. acrylamide, acrylic or methacrylic acid, 2-hydroxyethyl methacrylate or N-vinyl pyrrolidone and a polyfunctional monomer, e.g. ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, nonaethylene glycol dimethacrylate or methylene bis acrylamide and reacting the mixture by exposure to light or heat in the presence of an initiator. The pullulan may also be modified by esterification, alkyl etherification or hydroxyalkyl etherification, may be blended with a water-soluble polymer, e.g. polyvinyl alcohol, polyethylene amine, polyacrylamide, polyacrylic acid, polyvinyl pyrrolidone, polyethylene oxide, sodium alginate, carboxy methyl cellulose, sodium polyacrylate or hydroxyethyl cellulose or may be plasticized with dimethyl sulphoxide, water, amylose, glycerol, ethylene glycol, polyethylene glycol, sorbitol, propylene glycol or polypropylene glycol. The plastics material may be a homo- or copolymer of an olefin, e.g. ethylene or propylene and/or a vinyl compound e.g. styrene, acrylonitrile, vinyl acetate, vinyl chloride, vinylidene chloride, vinyl tetrafluoride, vinylidene fluoride, acrylic or methaoxylic acid, or a salt or ester of acrylic or methacrylic acid, a polyester, e.g. polyethylene or polybutylene terephthalate or a polycarbonate, nylon, a cellulose derivative, e.g. regenerated cellulose, a mono-, di- or tri-acetate of cellulose, carboxymethyl cellulose, or an alkyl cellulose, polypolyvinyl alcohol or rubber hydrochloride, the plastics material optionally containing additional additives and having been optionally sub - jected to foaming, stretching or surface activation, e.g. by flame, corona discharge or acid or -alkali treatment. The material of the invention may be produced by multi-layer extrusion, extrusion coating, hot pressing of preformed layers, liquid adhesive lamination; lamination of co-extruded layers, by applying a pullulan solution or emulsion and drying the coating, by multi-layer injection moulding, multi-layer extrusion blow moulding or multilayer injection blow moulding, and may be in the form of a film, sheet, tube, pipe or bottle. When an extrusion coating technique is used an anchor coating agent, e.g. an organotitanate, an organo aluminium compound, polyethyleneamine, a urea, or melamine aldehyde resin or a polyurethane may be used.