Annulated tubular structure intended for transporting fuel into the tank

Abstract

A partially annulated flexible tubular structure located at least partially inside the fuel tank, of a vehicle, the structure being capable of being at least partially submerged in the tank and being intended for transporting the fuel into the tank, the tubular structure including at least one layer (1) including a composition including: a. between 39% and 100% by weight, in particular between 41% and 100% by weight, of at least one aliphatic polyamide of formula W/Z, b. between 0% and 4% by weight, and preferably between 0 and 2%, of at least one plasticizer, c. between 0% and 20% of at least one impact modifier, d. between 0% and 37% by weight of at least one additive, the sum of a.+b.+c.+d. being equal to 100% of the total weight of the composition, excluding a fuel transport structure running from the tank to the motor of the vehicle.

1 . A partially annulated flexible tubular structure located at least partially inside the fuel tank of a vehicle, said structure being at least partially submerged in said tank and for use in transporting fuel into said tank,
 said tubular structure comprising at least one layer (1) having a composition comprising:   a. between 39% and 100% by weight, of at least one aliphatic polyamide of formula W/Z wherein:   W is an aliphatic repeating unit obtained from the polycondensation of at least one C6-C18 lactam, or at least one C6-C18 aminocarboxylic acid, or is an aliphatic repeating unit XY having an average number of carbon atoms per denoted nitrogen atom ranging from 6 to 18, obtained from the polycondensation:   at least one C6-C18 diamine X, said diamine being selected from a linear or branched aliphatic diamine or a mixture thereof, and   at least one C6-C18 aliphatic dicarboxylic acid Y,   Z is at least one optional polyamide repeating unit, Z present at up to 30% by weight relative to the total weight W/Z,   b. between 0% and 4% by weight of at least one plasticizer,   c. between 0% and 20% of at least one impact modifier,   d. between 0% and 37% by weight of at least one additive,   the sum of a.+b.+c.+d. being equal to 100%,   excluding a fuel transport structure running from the tank to the motor of the vehicle.   
     
     
         2 . The tubular structure according to  claim 1 , wherein said at least one aliphatic polyamide is at least one polyamide denoted C obtained from the polycondensation of at least one C6-C18 lactam, or of at least one C6-C18 aminocarboxylic acid, and having an average number of carbon atoms per nitrogen atom denoted CC ranging from 9 to 18. 
     
     
         3 . The tubular structure according to  claim 2 , wherein said constituent a. of said composition further comprises another polyamide selected from the group consisting of:
 at least one polyamide denoted A having an average number of carbon atoms per nitrogen atom denoted CA ranging from 4 to 8.5;   at least one polyamide denoted B having a melting temperature higher than or equal to 180° C. and an average number of carbon atoms per nitrogen atom denoted CB ranging from 7 to 10;   and a mixture thereof,   the weighted average mass of the melting enthalpies of the polyamides being higher than 25 J/g (DSC),   the average number of carbon atoms per nitrogen atom of the polyamides A, B and C further satisfying the following strict inequation: CA<CB<CC.   
     
     
         4 . The tubular structure according to  claim 3 , wherein the composition comprises between 34 and 84% by weight of aliphatic polyamide C relative to the total weight of the polyamides present within said composition, preferably between 50 and 80%. 
     
     
         5 . The tubular structure according to  claim 3 , wherein polyamide A is selected from PA 6, PA 46 and PA 66, polyamide B is selected from PA 610, PA 612, and polyamide C is selected from PA 11 and PA 12. 
     
     
         6 . The tubular structure according to  claim 1 , wherein W in said at least one aliphatic polyamide of formula W/Z is at least one aliphatic repeating unit XY, which is a polyamide denoted B′ having a melting temperature higher than or equal to 180° C., and an average number of carbon atoms per nitrogen atom denoted CB′ ranging from 7 to 10, or a polyamide denoted C′ having an average number of carbon atoms per nitrogen atom denoted CC′ ranging from 9 to 18. 
     
     
         7 . The tubular structure according to  claim 6 , wherein said constituent a. of said composition consisting of at least one aliphatic polyamide denoted B′ or denoted C′ further comprises another polyamide selected from:
 at least one polyamide denoted A having an average number of carbon atoms per nitrogen atom denoted CA ranging from 4 to 8.5; 
 at least one polyamide denoted B″ having a melting temperature higher than or equal to 180° C. and an average number of carbon atoms per nitrogen atom denoted CB ranging from 7 to 10, when said aliphatic polyamide is C′, 
 at least one polyamide denoted C″ having an average number of carbon atoms per nitrogen atom denoted CC″ ranging from 9 to 18, when said aliphatic polyamide is B′; 
 or a mixture thereof, 
 the weighted average mass of the melting enthalpies of the polyamides being higher than 25 J/g (DSC), 
 the average number of carbon atoms per nitrogen atom in polyamides A, B′, B″, C′ and C″ further satisfying the following strict inequation: CA<CB″ or CB″<CC′ or CC″. 
 
     
     
         8 . The tubular structure according to  claim 6 , wherein the composition comprises between 34 and 84% by weight of aliphatic polyamide B′ or aliphatic polyamide C′ relative to the total weight of the polyamides present within said composition. 
     
     
         9 . The tubular structure according to  claim 7 , wherein polyamide A is selected from PA 6, PA 46 and PA 66, polyamide B′ is selected from PA 610, PA 612, preferably PA 610, and polyamide C″ is selected from PA 11, PA 12, PA 1012, PA 618 and PA 1010, or polyamide A is selected from PA 6, PA 46 and PA 66, polyamide B″ is selected from PA 610, PA 612, preferably PA 610 and polyamide C′ is selected from PA 1012, PA 618 and PA 1010. 
     
     
         10 . The tubular structure according to  claim 1 , wherein n that the additives d. is selected from the group consisting of carbon black, graphite, graphene, carbon fibers, carbon nanotubes an antioxidant, a heat stabilizer, a UV absorber, a light stabilizer, a lubricant, an inorganic filler, a fire-proofing agent, a nucleating agent, a dye, reinforcing fibers, a wax, and mixtures thereof. 
     
     
         11 . The tubular structure according to  claim 10 , wherein said additive comprises carbon black. 
     
     
         12 . The tubular structure according to  claim 11 , wherein said composition of said layer (1) comprises:
 a. between 39% and 95% by weight of at least one aliphatic polyamide,   b. between 0% and 4% by c. between 0% and 20% of at least one impact modifier,   d. between 5% and 32% by weight of carbon black, and   between 0 and 5% by weight of at least one additive other than carbon black, graphite, graphene, carbon fibers and carbon nanotubes,   the sum a.+b.+c.+d. being equal to 100%.   
     
     
         13 . The tubular structure according to  claim 11 , wherein said composition of said layer (1) comprises:
 a. between 39% and 85% by weight of at least one aliphatic polyamide,   b. between 0% and 4% by weight of a plasticizer,   c. between 10% and 18% of at least one impact modifier,   d. between 5% and 32%, by weight of carbon black, and   
       between 0 and 5% by weight of at least one additive other than carbon black, graphite, graphene, carbon fibers and carbon nanotubes,
 the sum a.+b.+c.+d. being equal to 100%. 
 
     
     
         14 . The tubular structure according to  claim 10 , wherein said additive is at least carbon nanotubes. 
     
     
         15 . The tubular structure according to  claim 14 , wherein said composition of said layer (1) comprises:
 a. between 70% and 99.5% by weight of at least one aliphatic polyamide,   b. between 0% and 4% by weight of a plasticizer,   c. between 0% and 20% of at least one impact modifier,   d. between 0.5% and 10% by weight of an additive which is carbon nanotubes, and   
       between 0 and 19% by weight of at least one additive other than carbon black, graphite, graphene, carbon fibers and carbon nanotubes,
 the sum a.+b.+c.+d. being equal to 100%. 
 
     
     
         16 . The tubular structure according to  claim 14  or  15 , wherein said composition of said layer (1) comprises:
 a. between 70% and 89.5% weight of at least one aliphatic polyamide, 
 b. between 0% and 4% by weight of a plasticizer, 
 c. between 10% and 18% of at least one impact modifier, 
 d. between 0.5% and 10% by weight of carbon nanotubes, and 
 between 0 and 19% by weight of at least one additive other than carbon black, graphite, graphene, carbon fibers and carbon nanotubes, 
 the sum a.+b.+c.+d. being equal to 100%. 
 
     
     
         17 . The tubular structure according to  claim 1 , wherein the layer (1) is devoid of plasticizer. 
     
     
         18 . The tubular structure according to  claim 1 , wherein said structure is annulated over at least 10% of its length. 
     
     
         19 . The tubular structure according to  claim 1 , wherein at least 90% of the length of said structure is inside the tank. 
     
     
         20 . The tubular structure according to  claim 1 , wherein at least 30% of the length of said structure is submerged in the fuel. 
     
     
         21 . The tubular structure according to  claim 1 , wherein said structure consists of a single layer and is devoid of any additive selected from carbon black, graphite, graphene, carbon fibers and carbon nanotubes. 
     
     
         22 . The tubular structure according to  claim 21 , wherein the thickness of said layer (1) is at least 600 μm. 
     
     
         23 . The tubular structure according to  claim 1 , wherein said structure comprises at least one second layer (2) that is conductive or non-conductive, said layer (1) being located above or below said layer (2). 
     
     
         24 . The tubular structure according to  claim 23 , wherein said layer (1) is located above said layer (2). 
     
     
         25 . The tubular structure according to  claim 23 , wherein said second layer (2) comprises at least one aliphatic polyamide or fluorinated materials selected from the group consisting of polyvinylidene fluoride (PVDF), functionalized fluorinated materials, functionalized ethylene-tetrafluoroethylene (ETFE) copolymer, functionalized ethylene-tetrafluoroethylene-hexafluoropropylene (EFEP) copolymer, and tetrafluoroethylene-perfluoro (alkylvinyletherchlorotrifluoroethylene (CPT) copolymer. 
     
     
         26 . The tubular structure according to  claim 23 , wherein said structure is devoid of a barrier layer, said second layer (2) comprising at least one aliphatic polyamide. 
     
     
         27 . A method for transporting fuels into a tank, comprising the step of transporting a fuel through a tubular structure according to  claim 1 .