HIGH-STRENGTH POLYPROPYLENE-BASE BARRIER FILM FOR PACKING PURPOSES, METHOD FOR THE PRODUCTION AND THE USE THEREOF

摘要

The multilayer foil is produced by simultaneous stretching of a coextruded multilevel primary foil and the functional layer: comprises an amorphous or semicrystalline polyamide or mixture of the polyamide with ethylene-vinyl alcohol copolymers; exhibits a moralization or SiO x or AlO x ceramic coating; and has oxygen permeability with 23[deg]C and 75 % relative air humidity under 0.20 cm 3>/(m 2>datm), and steam permeability under 38[deg]C, 90% relative air humidity under 0.5 g (m 2>datm). The stretched layer (thickness of 8-80 mu m) exhibits a thermo plastic layer for corona/plasma treatment and the heat-sealable thermoplastic external layer. The interior layer is arranged between the stretched layers. The detention layers (75 wt% of polypropylene) are formed on the barrier layer (thickness of 0.5-10 mu m) and modified by mixing with an anhydride-modified polyamide, a polyethylene copolymer or an anhydride-modified acrylate resin. The stretched layer and/or the detention layer contain mineral or organic additives for the formation of microcavities, fillers, absorbents, UV and light protective, coloring and covering pigments. An independent claim is also included for production of multilayer barrier foil.