| 摘要 |
1,210,976. Coated films. E. I. DU PONT DE NEMOURS & CO. 11 July, 1968 [13 July, 1967], No. 33121/68. Heading B2E. A substantially oxygen impermeable flexible film structure comprises a polymeric film base, at least one surface of which has been treated for adherability, having a coating, at least 0.0025 mm. thick on the treated surface of the film-base, consisting essentially of a substantially unoriented acrylonitrile polymer containing at least 75% by wt. of acrylonitrile, 0 to 25% by wt. of a copolymerizable monomer other than a monomer containing an N-alkylolamide group, examples of which are given, the polymer having an intrinsic viscosity of at least 0.8 in dimethylformamide at 30‹C. The coating may consist essentially of a substanitally unoriented acrylonitrile homopolymer. The film base may be an oriented, dimensionally-stabilized, thermoplastic polypropylene, polyethylene terephthalate, polycarbonate, polyalkylene glycol esters of isophthalic and naphthoic acids, polychlorotrifluoroethylene, polymethacrylonitrile, copolymers of tetrafluoroethylene and hexafluoro propene, and vinylidene chloride copolymer coated regenerated cellulose film. The acrylonitrile polymer coating may bear a heat-sealable polymer coating selected from homopolymers of ethylene or vinylidene chloride, and copolymers of ethylene or vinylidene chloride with vinylacetate, an alkyl acrylate) or alkacrylate. The structure is produced by coating at least one surface of the film base, which has been treated for adherability, with the acrylonitrile polymer in a volatilizable liquid, e.g. an organic solvent, which is subsequently removed by heating the coated film at an elevated temperature, e.g. to the extent that the residual solvent content is less) han 1% by wt. of the coating. The adherability treatment may be by electrical discharge, flame, chlorination, and oxidation, e.g. with chromic acid. The acrylanitiile polymer coating may be applied by dip, kiss or gravure coating techniques. The heat-scalable coating may be applied as a melt solution or dispersion. |
