COEXTRUDIERTE MEHRSCHICHTIGE BARRIEREFOLIE MIT WENIGSTENS EINER FOLIENLAGE AUS ETHYLEN- VINYLALKOHOL-COPOLYMERISAT (EVOH), VERFAHREN ZU IHRER HERSTELLUNG UND IHRE VERWENDUNG

摘要

Barrier film for use in packaging, particularly for the packaging of foods and tobacco, in the form of a multi-layer film based on a biaxially oriented polyolefin film having at least one coextruded functional layer or barrier based on ethylene-vinyl alcohol copolymers (EVOH), which is produced by simultaneous drawing of a coextruded multi-layer primary film at temperatures of 145° C. and below, the ethylene content of the EVOH being below 40 mol % and the thickness of the EVOH layer being less than 5 mum, in particular less than 2 mum, thereby producing values for the oxygen permeability at 23° C. and 75% relative humidity (OTR; ASTM 3985) of better than 10 cm3/m2 dbar, preferably better than 5 cm3/m2 dbar.