MULTILAYER STRUCTURE BASED ON RUBBER AND ON A GRAFT POLYAMIDE BLOCK COPOLYMER, AND ITS USE AS TUBES FOR CONDITIONED AIR AND COOLING CIRCUITS

The multi-layer structure with a rubber and a grafted copolymer base for transporting hydrofluoroalkane or carbon dioxide, comprises first internal rubber/polyamide layer, a layer of grafted copolymer base, a second rubber layer, optionally binder layer, an external rubber layer and a polyamide layer. A layer of the grafted copolymer base with polyamide blocks is made up of polyolefin backbone and a graft polyamide in which the grafts are attached to the backbone by residues of unsaturated carboxylic acid anhydride monomer. The multi-layer structure with a rubber and a grafted copolymer base for transporting hydrofluoroalkane or carbon dioxide, comprises first internal rubber/polyamide layer, a layer of grafted copolymer base, a second rubber layer, optionally binder layer, an external rubber layer and a polyamide layer. A layer of the grafted copolymer base with polyamide blocks is made up of polyolefin backbone and a graft polyamide in which the grafts are attached to the backbone by residues of unsaturated carboxylic acid anhydride monomer. The monomer reacts with the polyamide layer and an amine at a terminal group. The monomer is fixed to the backbone by grafting or copolymerizing from its double bonds. Another layer of grafted copolymer with polyamide blocks is placed between the grafted copolymer layer and barrier material layer. The grafted copolymer layers have nanocharges. An independent claim is included for tubes for an air conditioning circuit of motor vehicles.