POLYAMIDE-BASED MULTILAYER TUBE FOR TRANSFERRING FLUIDS

摘要

The present invention relates to a multilayer tube comprising, in its radial direction from the outside inwards: an outer layer (1) made of a polyamide, a tie layer(2) comprising, by weight: 1 to 50% of an impact modifier chosen from elastomers and very low density polyethylene, the said impact modifier being completely or partly functionalized, per 99 to 50% of at least one copolyamide 6/12 respectively, an optional EVOH layer (3), optionally a tie layer, an inner layer (4) made of PA 12, PA 6 or a PA 6 - polyolefin compound with a PA 6 matrix and a dispersed polyolefin phase, the layers being successive and adhering to one another in their respective contact zones. The inner layer is the layer in contact with the fluid being transferred. According to one embodiment of the invention, the inner layer (4) contains an electrically conducting material, producing a surface resistivity of less than 10⁶ O. According to another embodiment of the invention, the inner layer (4) contains essentially no electrically conducting material and the tube includes a layer (4a) that adheres to the layer (4), this layer is made of polyamide and contains an electrically conducting material producing a surface resistivity of less than 10⁶ O This layer (4a) becomes the inner layer. These tubes may have an outside diameter of 6 to 110 mm and a thickness of around 0.5 to 5 mm.