| 摘要 |
<p>1,271,995. Coated films. E.I. DU PONT DE NEMOURS & CO. 8 May, 1969 [8 May, 1968], No. 23576/69. Heading B2E. [Also in Division B5] A laminated oxygen barrier film comprises a thermally formable base layer, an oxygen barrier layer consisting essentially of a copolymer of 15 to 65 mole percent ethylene and 85 to 35 mole percent of a vinyl ester of an aliphatic C 1-4 mono basic acid, the copolymer being hydrolysed to the extent of at least 85% and having a melt index of from 0.5 to 75, and a heat sealable layer of a polymer or copolymer of ethylene. The resulting film preferably has an oxygen permeability of less than 3cc/100 sq. in./24 hours/atm. at 23‹C. The base layer is preferably propylene/ethylene copolymers, polyamides such as nylon, monomeric copolymers, polypropylene, polyethylene or polyethylene terephthalate. The barrier copolymer is preferably at least 98% hydrolysed ethylene/vinyl acetate copolymer in the mole proportion 44:56. The heat sealable layer may be polyethylene or ethylene/vinyl acetate. The three layers may be joined by a hot melt adhesive such as an ethylene/ethyl acrylate copolymer. The laminar films may be produced by coextrusion of the three layers, or one or more of the layers can be preformed and the remaining layer(s) applied by melt coating or extrusion lamination or the individual layers formed and combined in a typical laminating operation.</p> |
