Polyamide-based multilayer tube for transferring fluids
View Patent ↗The present invention relates to a multilayer tube comprising, in its radial direction from the outside inwards: an optional layer (1) made of nylon-11 or nylon-12 polyamide; an intermediate layer (2) comprising by weight, the total being 100%: 50 to 100% of at least one polyamide A1 of formula X, Y/Z or 6, Y2/Z, in which X denotes residues of an aliphatic diamine having from 6 to 10 carbon atoms, Y denotes residues of an aliphatic dicarboxylic acid having from 10 to 14 carbon atoms, Y2 denotes residues of an aliphatic dicarboxylic acid having from 15 to 20 carbon atoms, Z denotes at least one unit chosen from residues of a lactam, residues of an α,Ω-aminocarboxylic acid, the unit X1, Y1, in which X1 denotes residues of a diamine and Y1 denotes residues of a diacid, the weight ratios Z/(X+Y+Z) and Z/(6+Y2+Z) being between 0 and 15%, and 0 to 50% of nylon-11 or nylon-12 polyamide; an optional layer (3) made of nylon-11 or nylon-12 polyamide, with the condition that at least one of the layers (1) and (3) is present; the layers being successive and adhering to one another, the inner layer being the layer in contact with the fluid transported.
1. A multilayer tube consisting, in its radial direction from the outside inwards:
a) a layer (1) made of nylon-11 or nylon-12 polyamide,
b) an intermediate layer (2) comprising a blend of polyamide A1 and one of nylon-11 or nylon-12 by weight, the total being 100%;
50 to less than 100% of at least one polyamide A1 selected from the group consisting of PA-6,10, PA-6,12 and PA-6,14, and
up to 50% of nylon-11 or nylon-12 polyamide;
c) a layer (3) made of nylon-11 or nylon-12 polyamide,
the layers being successive and adhering to one another, the inner layer being the layer in contact with the fluid transported.
2. The multilayer tube according to claim 1 , wherein the innermost layer contains an electrically conductive material.
3. The multilayer tube according to claim 1 , wherein the polyamide A1 is PA-6,10.
4. The multilayer tube according to claim 1 , wherein the polyamide A1 is PA-6,12.
5. The multilayer tube according to claim 1 , wherein the polyamide A1 is PA-6,14.
6. The multilayer tube according to claim 1 , wherein the intermediate layer (2) comprises by weight, the total being 100%:
70 to less than 100% of the at least one polyamide A1, and
up to 30% of nylon-11 or nylon-12 polyamide.
7. The multilayer tube according to claim 1 , comprising a fuel transport tube.
8. The multilayer tube of claim 1 , wherein layer (1) and layer (3) are made the same polyamide.
9. The multilayer tube of claim 1 , wherein the PA-11 or PA-12 of the intermediate layer (2) is the same as the polyamide of the inner and outer layers.