Patent ID: 7794806

Claim:
A multilayer structure, which comprises a coextrusion tie layer (L) comprising 5 to 35% by weight of a polymer (A) itself composed of a blend of 80 to 20% by weight of a metallocene polyethylene (A1) with a density of between 0.863 and 0.915 and of 20 to 80% by weight of a non-metallocene LLDPE polyethylene (A2) with a density of between 0.900 and 0.950, the blend of polymers (A1) and (A2) being cografted by a grafting monomer chosen from unsaturated carboxylic acids and their derivatives, the content of the grafting monomer in said blend being between 30 and 100 000 ppm; 95 to 65% by weight of metallocene polyethylene (B) homo- or copolymer, the comonomer of which comprises 3 to 20 carbon atoms, the density of which is within a range in which the minimum density of the range is 0.863 and the upper density value of the range is 0.902 and the MFI, melt flow index, of which, measured under 2.16 kg at 190° C. according to Standard ASTMD 1238, is between 0.5 and 30, g/10 min; the total forming 100%, the blend of (A) and (B) being such that its MFI is between 0.1 and 15, g/10 min, and wherein the adhesive strength of said coextrusion tie is increased by 5 to 50% between the time t=0 corresponding to its application immediately after its extrusion and the time t=8 days; and a layer (E) directly attached to one of the two faces of said layer (L), said layer (E) being a polyester layer.