Uniaxially shrinkable biaxially oriented polypropylene film and method for use as tobacco pack overwrap
    4.
    发明授权
    Uniaxially shrinkable biaxially oriented polypropylene film and method for use as tobacco pack overwrap 失效
    单轴收缩双轴取向聚丙烯薄膜和用作烟草包装外包装的方法

    公开(公告)号:US06534189B1

    公开(公告)日:2003-03-18

    申请号:US09887657

    申请日:2000-01-09

    IPC分类号: B32B2732

    摘要: A uniaxially heat-shrinkable, biaxially oriented, multilayer film for use as a tobacco pack or carton overwrap having a polypropylene-containing core layer comprising at least 70 wt % of said multilayer film and at least one polyolefin-containing skin layer adjacent said core layer is prepared by biaxially orienting a coextrudate and thereafter orienting said coextrudate by stretching 10 to 45% in the machine direction. The core layer contains isotactic polypropylene and a modifier which reduces the crystallinity of the polypropylene-containing core. Such modifiers can be selected from the group consisting of atactic polypropylene, syndiotactic polypropylene, ethylene-propylene copolymer, propylene-butene-1 copolymer, ethylene-propylene-butene terpolymer, polyethylene and linear low density polyethylene. The skin layer can be selected from the group consisting of polypropylene, ethylene-propylene copolymer, polyethylene, and ethylene-propylene-butene-1 terpolymer and contains silicone oil.

    摘要翻译: 一种用作烟草包装或纸箱外包装的单轴热收缩双轴取向多层膜,其具有包含至少70重量%的所述多层膜的含聚丙烯芯层和与所述芯层相邻的至少一个含聚烯烃的表皮层 通过双轴取向共挤出物制备,然后通过在机器方向上拉伸10-45%来使所述共挤出物定向。 芯层包含全同立构聚丙烯和降低含聚丙烯芯的结晶度的改性剂。 这种改性剂可以选自无规立构聚丙烯,间同立构聚丙烯,乙烯 - 丙烯共聚物,丙烯 - 丁烯-1共聚物,乙烯 - 丙烯 - 丁烯三元共聚物,聚乙烯和线性低密度聚乙烯。 表层可以选自聚丙烯,乙烯 - 丙烯共聚物,聚乙烯和乙烯 - 丙烯 - 丁烯-1三元共聚物,并含有硅油。