Patent ID: 6270882
Filing Date: 2001-08-07
Classification: B32B,Y10T

Abstract:
A heat sealable, unoriented multi-layer film consisting of a sequence of layers (I) comprising one or more plies on the outer side of the film, a sequence of layers (II) also comprising at least one ply, denoted the heat sealable layer, on the other outer side of the film, optionally together with a coupling sequence of layers (III), also of one or more plies, between the sequences of layers (I) and (II), wherein the multi-layer film is characterised in that the sequence of layers (I) contains at least one layer (i) of a linear alternating copolymer of carbon monoxide and at least one ethylenically unsaturated olefin, optionally together with one or more layers (ii) containing polyamide, characterised in that the ratio between the thicknesses of the sequence of layers (I) and the total multi-layer film is no greater than 0.6 and no less than 0.15, that the total thickness of the multi-layer film is no less than 50 and no more than 300 .mu.m, and that at least one melting point, determined using the DSC method to ASTM 34178, of one of the polymeric components present in the sequence of layers (II) is at least 50.degree. C. lower than at least one melting point, determined using the DSC method to ASTM 3418, of one of the polymers present in the sequence of layers (I), said film characterized in that it is halogen-free.