MULTILAYER BLOWN FILM STRUCTURE WITH POLYPROPYLENE NON-SEALANT LAYER AND POLYETHYLENE SEALANT LAYER

摘要

The present invention pertains to a multilayer blown film structure having a blended polypropylene layer and at least one polyethylene sealant layer. In particular, the invention relates to a multilayer brown film comprising a non-sealant layer made from a propylene-rich polypropylene polymer blended with at least one ethylene-rich ethylene interpolymer and a sealant layer made from at least one ethylene interpolymer, wherein the ethylene-rich ethylene interpolymer comprises ethylene interpolymerized with at least one other comonomer other than propylene. The novel multilayer film structure exhibits excellent interlayer adhesion (especially at the blended non-sealant/sealant interface when adjacent to one another) and toughness (for example, excellent trouser tear) with acceptable optical properties and surprising sealing properties. The novel structure is preferably made using an air-quenched coextrusion fabrication technique and is particularly suited for use in making pouches for flowable materials, heavy-duty shipping sacks and overwrap films.