PROCESS FOR EXTRUSION COATING AND LAMINATING ORIENTED POLYPROPYLENE FILM, TIE-LAYER COMPOSITIONS FOR SUCH A PROCESS AND MULTI-LAYER FILMS WITH LAYERS BONDED BY SUCH TIE-LAYERS

摘要

The invention relates to a process for extrusion lamination or extrusion coating on a continuous line comprising: a) supplying an OPP substrate layer; b) extruding a composition comprising a propylene based elastomer as a tie-layer extruded in molten form onto the surface of the OPP substrate without the interposition of a primer applied from a primer diluent mixture and c) laminating or coating a further layer a to provide an adhesive strength between the substrate layer and the further layer of at least 0.4 N/15 mm, preferably at least 1 N/15 mm. Especially useful are tie-layer compositions which composition contain from 2 to 98 wt% of a propylene-based elastomer and from 5 to 70 wt% of a free radical produced low density ethylene based polymer, preferably an LDPE or an interpolymer of ethylene and a copolymerizable ester and/or acid group containing monomer, optionally at least partly neutralized.