| abstract |
The present invention relates to a multilayer tube comprising in its radial direction from the outside to the inside: an outer layer (1) of polyamide, an inner layer (2) of a composition comprising, the total being 100%: 5 to 30% by weight of a mixture (A) comprising: a polyethylene bearing epoxy functions, an impact modifier selected from elastomers and very low density polyethylenes, said impact modifier being wholly or partly functionalized, 95 to 70% by weight weight of a mixture (B) comprising: a fluorinated polymer (B1), a functionalized fluoropolymer (B2), the proportion of (B1) is between 1 and 60% by weight of (A) + (B), the layers being successive and adhering to each other in their respective contact zone. The inner layer is the layer in contact with the transported fluid. The layer (2) can be conductive. It is also possible to have a layer of polyamide (3) on the side of the layer (2), this layer becomes the inner layer. The tube of the present invention is very slightly permeable to gasoline, particularly to hydrocarbons and their additives, in particular especially alcohols such as methanol and ethanol or even ethers such as MTBE or ETBE. These tubes also have good resistance to fuels and engine lubricating oils. This tube has very good mechanical properties at low or high temperature. The invention also relates to the use of these tubes for transporting gasoline. |