| 摘要 |
The present invention relates to a multilayer tube comprising, in its radial direction from the outside inwards: a polyamide outer layer (1); an inner layer (2) of a composition comprising, the total being 100%, 5 to 30% by weight of a blend (A) comprising: a polyethylene carrying epoxy functional groups, an impact modifier chosen from elastomers and very low-density polyethylenes, the said impact modifier being completely or partly functionalized; 95 to 70% by weight of a blend (B) comprising: a fluoropolymer (B1), a functionalized fluoropolymer (B2), the proportion of (B2) being between 1 and 80% by weight of (A)+(B), the layers being successive and adhering to one another in their respective contact region. The inner layer is the layer in contact with the fluid being transported. The layer (2) may be conductive. It is also possible to place a polyamide layer (3) beside the layer (2), which layer becomes the inner layer. The tube of the present invention has a very low permeability to petrol, particularly to hydrocarbons and to their additives, in particular alcohols such as methanol and ethanol, or even ethers such as MTBE or ITBE. These tubes also exhibit good resistance to fuels and to lubricating oils for engines. This tube exhibits very good mechanical properties at low temperature and at high temperature. The invention also relates to the use of these tubes for transporting petrol. |
