Patent ID: 7862872

Claim:
A multilayer structure comprising, in this order: a) a first layer (1) comprising a polyamide (A) or a polyamide (A)/polyolefin (B) blend having a polyamide matrix; b) optionally, a tie layer (2a); c) a polymeric layer (2) wherein the polymer comprises a graft copolymer having polyamide blocks, said graft copolymer comprising a polyolefin backbone and at least one polyamide graft from a polyamide having an amine end group, wherein: the grafts are attached to the polyolefin backbone by the residues of an unsaturated monomer (X) having a functional group capable of reacting with said polyamide having an amine end group; the residues of said unsaturated monomer (X) being attached to the backbone by grafting or copolymerization via its double bond; and the average number of moles of unsaturated monomer X attached to the polyolefin backbone is 1.3 to 7 moles per mole of chain; layer (1), optionally layer (2a), and layer (2) being successive and adhering to one another in their respective contact region, wherein the proportion by weight of the polyolefin backbone to the polyamide having an amine end group is 80/20 to 90/10, and wherein said multilayer structure is in the form of a tube.