Use of a multilayer structure comprising a layer of polyamide and an aliphatic polyamide, optionally a binder layer and a layer containing e.g. an ethylene vinyl alcohol layer or a semi-aromatic copolyamide layer, to make methane pipelines

摘要

Use of a multilayer structure comprising from exterior towards interior, a layer (L1) of polyamide (PA) i.e. PA 11, PA 12 and an aliphatic polyamide obtained by condensing aliphatic diamine and aliphatic diacid, optionally a binder layer (L2) and a layer (L3) containing an ethylene vinyl alcohol (EVOH) layer, a layer of a mixture of polyamide or a polyolefin with polyamide matrix, a layer of PA6, PA6-6, a layer of semi-aromatic copolyamide or a polyphthalamide layer, to make gas pipelines, where (L3) is in contact with the gas conveyed. Use of a multilayer structure comprising from exterior towards interior, successive layers comprising a layer (L1) containing a polyamide (PA) i.e. PA 11, PA 12 and an aliphatic polyamide resulting from condensation of an aliphatic diamine with 6-18 carbon atoms and an aliphatic diacid with 9-18 carbon atoms, optionally a binder layer (L2) and a layer (L3) containing a layer of ethylene vinyl alcohol (EVOH), a layer composed of a mixture of polyamide and a polyolefin with polyamide matrix, a layer of PA6, PA6-6, a layer of semi-aromatic copolyamide or a polyphthalamide layer, for the manufacture gas pipelines, where the layer (L3) is in contact with the gas conveyed.