A multilayer structure of, in succession, a metal layer or a metallized-substrate layer, a layer of a polypropylene-based binder extrusion-coated at a rate of more than 100 m/min. and optionally a polypropylene layer, the metal or metallized layer and the binder layer being made non-delaminable by heat treating the structure. The extrudable binder contains by weight: (A) 5 to 30% of a copolymer of ethylene and one or more comonomers chosen from the group of carboxylic acid esters, vinyl esters and dienes in particular the ethylene/alkyl (meth)acrylate/maleic anhydride terpolymer; (B) 40 to 93% of a stretchable polypropylene; and (C) 2 to 30% of a polypropylene functionalized by an unsaturated carboxylic acid anhydride, especially maleic anhydride; the MFI of the composition being between 10 and 50 g/10 min. (at 230 C./2.16 kg). the multi-layer structure is useful for the production of packages.