Multilayer film having at least one thin layer and continuous process for forming such a film

Abstract

The invention relates to a continuous self-metered process of forming a multilayer film comprising at least two superimposed polymer layers comprising the steps of: (i) providing a substrate (); (ii) providing two or more coating knives () which are offset, independently from each other, from said substrate () and/or from an adjacent coating knife to form at least one substrate gap () relative to the surface of the substrate () and at least one outlet gap () relative to the surface of an adjacent coating knife; (iii) moving the substrate () relative to the coating knives () in a downstream direction (), (iv) providing curable liquid precursors of the polymers (I, II, III) to the upstream side of the coating knives () thereby coating the two or more precursors (I, II, III) through the respective gaps () as superimposed layers () onto the substrate (); (v) optionally providing one or more solid films () and applying these essentially simultaneously with the formation of the adjacent lower polymer layer, and (vi) curing the precursor of the multilayer film thus obtained; wherein a lower layer of a curable liquid precursor (I, II, III) is covered by an adjacent upper layer of a curable liquid precursor (I, II, III) or a film (), respectively, essentially without exposing said lower layer of a curable liquid precursor (I, II, III).