MULTILAYER TUBULAR STRUCTURE HAVING IMPROVED RESISTANCE TO EXTRACTION IN BIOGASOLINE AND USE THEREOF

摘要

The present invention is a multi-layer tubular structure (MLT) intended for the transport of fluids, especially gasoline, especially alcohol-containing gasoline, comprising: from outside to inside, at least one barrier layer (1) and at least one inner layer (2) located below the barrier layer. Including, Said inner layer (2), or all layers (2) and other optional layers located under the barrier layer, respectively, are the total weight of the composition of layer (2), or all of the layers (2) and other optional layers located under the barrier layer, respectively. Contains an average of 0 to 1.5% by weight of plasticizer relative to the total weight of the composition, The inner layer (2) mainly comprises one or more aliphatic type polyamides, or consists of more than 75% of aliphatic units, wherein the aliphatic polyamides are: -A polyamide represented by A, wherein the average number of carbon atoms per nitrogen atom represented by C _A is 4 to 8.5, advantageously 4 to 7; -A polyamide represented by B, wherein the average number of carbon atoms per nitrogen atom represented by C _B is 7 to 10, advantageously 7.5 to 9.5; -Polyamides represented by _C , wherein the average number of carbon atoms per nitrogen atom represented by C _C is 9 to 18, advantageously 10 to 18 Is selected from; Provided that when the inner layer (2) comprises three or more polyamides, at least one of the polyamides A, B and C is excluded, It relates to a multi-layer tubular structure (MLT).