| 摘要 |
A multi-layer packaging film is provided having at least four layers arranged in sequence comprising: (1) a heat-sealing first layer comprising at least 50% by weight of a copolymer of propene, and at least one .alpha.-olefin selected from the group consisting of ethylene, butene-1, methylpentene-1, hexene-1, octene- 1, decene-1 and mixtures thereof, said copolymer having a propene content of at least 60 wt.%, a Tm between about 100ÀC and about 145ÀC, a Mw/Mn of between 1 and 5, and n-hexane extractables of less than 4 wt.%; (2) second and fourth layers each comprising (a) at least 10 wt.% of a first copolymer of ethylene and at least one C4 - C8 .alpha.-olefin, said copolymer having a density of from 0.900 to 0.915 g/cm3 and a melt index of less than 2 dg/min., (b) at least 10 wt.% of a second copolymer of ethylene with from 4 to 18 wt.% of a vinyl ester, alkyl acrylate, acrylic or methacrylic acid, and (c) from 0 to 60 wt.% of a third copolymer of ethylene and at least one C3 - C8 .alpha.-olefin having a density less than 0.900 g/cm3 and a melting point less of between 65-98ÀC.; and (3) a third layer comprising at least 80% by weight of at least one copolymer of vinylidene chloride with from 2- 20 wt.% (based on said copolymer) of vinyl chloride or methyl acrylate. |
