Multilayer structures based on recycled polyamide

Abstract

A multi-layered tubular structure made from recycled tubing from used automobiles. [Solution] A multilayer tubular structure for transporting automotive fluids, comprising: a layer (1) made of at least 50% recycled material from a multilayer tube made of at least one polyamide-based composition for transporting automotive fluids; and a layer (2) made of at least one semicrystalline aliphatic polyamide and optionally at least one impact modifier, wherein the composition comprises at least one semicrystalline aliphatic polyamide which is PA12 and / or PA612 and / or PA1010, and the composition comprises at least one layer (2') made of a composition comprising at least one semicrystalline aliphatic polyamide, wherein layer (2) and layer (2') each consist of at least 90% non-recycled material.

Description

Background Art

[0001] Every year, millions of cars are discarded worldwide. Used cars (ELVs) contain many harmful substances and pollutants (liquids or solids), such as drained oil, batteries, air-conditioning fluids, and explosive mechanisms of airbags. Incorrect treatment of this waste may lead to soil and water pollution, as well as accidents. Therefore, ELVs are considered hazardous waste.

[0002] Many vehicle parts can be recovered and recycled as used parts or raw materials. Parts intended for reuse (such as headlights, winkers, engines, radiators, starter motors, bonnets, fenders, doors, etc.) are removed and stored for resale.

[0003] Frames and non-recyclable parts (such as ferrous and non-ferrous metals, plastics, glass, rubber, etc.) are shredded for recycling or landfill.

[0004] The European Directive 2000 / 53 / EC on used cars sets a reuse and recovery rate target of 95% by weight per car from 2015.

[0005] Only 5% of the final waste, i.e., the waste that cannot be processed under current technical and economic conditions and is either incinerated or sent to special storage facilities, remains.

[0006] The 95% that is reused and recovered is processed for the following purposes. Energy recovery: Use of waste (such as oil, tyres, plastics, etc.) as an energy generation means by direct incineration with or without other waste; Material recovery: Reuse: New use of parts that maintain the same application and are not deformed, or recycling: An operation that aims to introduce materials derived from waste into the production cycle and replaces all or part of the unused materials.

[0007] Automobiles have numerous pipes, particularly for transporting fluids such as air, oil (for example, for cooling the transmission oil cooler), water, urea solution, glycol-based coolant, and fuels such as gasoline, especially bio-gasoline or diesel, especially biodiesel, or hydrogen.

[0008] These pipes may be single-layer and / or multi-layer tubular structures, particularly based on polyamide.

[0009] When a vehicle is no longer in use, the various pipes inside it are generally excessively deteriorated or have deteriorated to the point where they cannot be reused in their original form without causing danger or excessive deterioration in their usability.

[0010] In fact, the pipes under the hood, in particular, are subjected to a harsh thermal oxidation environment due to the heat generated by the engine, which typically reaches 150°C, and the presence of air, and therefore oxygen. Typically, for every 10°C increase in temperature, the service life of the pipe is halved, and certain additives contained in the pipe, such as stabilizers, also deteriorate.

[0011] Furthermore, fuel transport hoses, such as polyamide hoses containing plasticizers, lose most of their plasticizers by the time they reach the end of their service life, and the original polyamide depolymerizes and / or degrades, losing most of its stabilizers, thus hindering safe reuse.

[0012] Currently, the pipes from used cars are not reused and are often incinerated, which later contributes to global warming, making their reduction one of the major challenges of the 21st century.

[0013] Furthermore, some car manufacturers have long-term goals to achieve zero environmental impact by recycling 100% of the vehicles they manufacture.

[0014] Therefore, supplying recycled pipes to these manufacturers becomes essential and also makes it possible to reduce the amount of pipes that are discarded or incinerated. [Overview of the project]

[0015] Therefore, the present invention relates to a multilayer tubular structure (MLT) for transporting automotive fluids, particularly air, oil (e.g., for transmission oil coolers or TOC cooling), water, urea solution, glycol-based coolant, or fuel, such as gasoline, particularly alcohol-based gasoline, bio-gasoline or diesel, particularly biodiesel, or hydrogen, comprising at least three layers: The composition comprises at least one layer (1) consisting of at least 50% polyamide resin, which comprises at least one first polyamide resin mainly containing aliphatic units and at least one second resin mainly containing aromatic units. The composition consists of at least 50% recycled material from multilayer tubes for transporting automotive fluids as defined above, wherein the tube comprises a layer (1) and a composition mainly comprising at least one polyamide, The composition comprises at least one layer (2) consisting mainly of at least one semicrystalline aliphatic polyamide and optionally at least one impact modifier, wherein the layer (2) consists mainly of a composition comprising at least one semicrystalline aliphatic polyamide which is PA12 and / or PA612 and / or PA1010, the composition comprises the impact modifier, and the layer (2) and At least one layer (2') consisting of a composition mainly comprising at least one semicrystalline aliphatic polyamide and Includes, The layer (2) and the layer (2') each consist of at least 90% non-recycled material. Regarding multilayer tubular structures (MLTs).

[0016] Accordingly, the inventors of the present invention have found that, surprisingly, a polyamide resin-based layer consisting of at least one first polyamide resin mainly comprising aliphatic units and at least one second resin mainly comprising aromatic units, and particularly a polyamide layer made of at least 50% recycled material and embedded between two polyamide layers, enables the construction of a multilayer tubular structure comprising at least three layers capable of transporting automotive fluids, particularly air, oil, water, urea solution, glycol-based coolant, or fuel, such as gasoline, particularly bio-gasoline or diesel, particularly biodiesel, or hydrogen, regardless of the type of fluid originally transported by the recycled multilayer tube constituting the embedded layer.

[0017] In other words, the present invention relates to a multilayer tubular structure (MLT) for transporting automotive fluids, particularly air, oil (e.g., for transmission oil coolers or TOC cooling), water, urea solution, glycol-based coolant, or fuel, such as gasoline, particularly alcohol-based gasoline, bio-gasoline or diesel, particularly biodiesel, or hydrogen, comprising at least three layers: The composition comprises at least one layer (1) consisting of at least 50% polyamide resin, which comprises at least one first polyamide resin mainly containing aliphatic units and at least one second resin mainly containing aromatic units. The composition consists of at least 50% recycled material from multilayer tubes for transporting automotive fluids as defined above, wherein the tube comprises a layer (1) and a composition mainly comprising at least one polyamide, The composition comprises at least one layer (2) consisting mainly of at least one semicrystalline aliphatic polyamide and optionally at least one impact modifier, wherein the layer (2) consists mainly of a composition comprising at least one semicrystalline aliphatic polyamide which is PA12 and / or PA612 and / or PA1010, the composition comprises the impact modifier, and the layer (2) and At least one layer (2') consisting of a composition mainly comprising at least one semicrystalline aliphatic polyamide and Includes, The layer (2) and the layer (2') each consist of at least 90% non-recycled material. Regarding multilayer tubular structures (MLTs). [Modes for carrying out the invention]

[0018] Therefore, the single-layer and / or multi-layer pipes that originally transported automotive fluids, from which the recycled material is obtained, are used pipes that have already transported the fluids for at least several months, and especially for several years.

[0019] Therefore, single-layer and / or multi-layer pipes that originally transported fluids are excluded from unused pipes.

[0020] The term "fluid" refers to gases or liquids used in automobiles, in particular air, oil, water, urea solution, glycol-based coolant, or fuel, such as gasoline, in particular alcohol-blended gasoline, bio-gasoline or diesel, in particular bio-diesel, or hydrogen.

[0021] Advantageously, the fluid refers to fuel, in particular gasoline, in particular alcohol-blended gasoline, bio-gasoline, or diesel, in particular biodiesel.

[0022] The term "gasoline" refers to a mixture of hydrocarbons obtained by distilling petroleum, to which additives or alcohols, such as methanol and ethanol, may be added, and in some cases alcohol is the main component.

[0023] "Alcohol-blended gasoline" refers to gasoline to which methanol or ethanol has been added. "Alcohol-blended gasoline" can also refer to E95 gasoline, which does not contain petroleum distillates.

[0024] The term "polyamide-based" means that the layer contains at least 50% by weight of polyamide.

[0025] The phrase "a composition mainly comprising at least one polyamide..." means that the composition contains at least 50% by weight of the polyamide.

[0026] In one embodiment, the layer (2) consists of a composition mainly comprising at least one semicrystalline aliphatic polyamide and at least one impact modifier in a ratio of 3 to 45% by weight of the total weight of the composition.

[0027] Regarding layer (1) Layer (1) is made of a composition comprising at least 50% polyamide resin, which consists of at least one first polyamide resin mainly comprising aliphatic units and at least one second resin mainly comprising aromatic units. The composition consists of at least 50% recycled material from multi-layer pipes used for transporting automotive fluids.

[0028] The nomenclature used to define polyamides is described in ISO standard 1874-1:2011 "Plastics - Polyamide (PA) Moulding and Extrusion Materials - Part 1: Designation" and is well known to those skilled in the art.

[0029] The term "polyamide" in this invention refers to both homopolyamides and copolyamides.

[0030] The term "first polyamide resin mainly containing aliphatic units" means that the first resin contains at least 50% aliphatic units.

[0031] The term "second polyamide resin mainly containing aromatic units" means that the first resin contains at least 50% aromatic units.

[0032] In one embodiment, the first polyamide resin, which mainly contains aliphatic units, is a semicrystalline polyamide.

[0033] Advantageously, the first polyamide resin, which mainly contains aliphatic units, is a semicrystalline aliphatic polyamide.

[0034] In another embodiment, the second polyamide resin, which mainly comprises aromatic units, is a semicrystalline polyamide.

[0035] Advantageously, the first polyamide resin, which mainly contains aromatic units, is a semi-crystalline semi-aromatic polyamide.

[0036] In yet another embodiment, the first polyamide resin mainly comprising aliphatic units and the second polyamide resin mainly comprising aromatic units are semicrystalline polyamides.

[0037] Advantageously, the first polyamide resin mainly comprising aliphatic units is a semicrystalline aliphatic polyamide, and the first polyamide resin mainly comprising aromatic units is a semicrystalline semi-aromatic polyamide.

[0038] Throughout this description, the term "semicrystalline polyamide" in the sense of the present invention refers to a polyamide having a melting temperature (Tm) and enthalpy of melting ΔH greater than 25 J / g, particularly greater than 40 J / g, and especially greater than 45 J / g, and further having a glass transition temperature (Tg) determined by DSC at a heating rate of 20 K / min in accordance with ISO standards 11357-1:2016 and ISO standards 11357-2 and 3:2013.

[0039] The at least one aliphatic semicrystalline polyamide is obtained from the polycondensation of at least one lactam, or from the polycondensation of at least one amino acid, or from the polycondensation of at least one diamine Xa and at least one dicarboxylic acid Yb.

[0040] If the at least one semicrystalline aliphatic polyamide is obtained from the polycondensation of at least one lactam, the at least one lactam may be selected from C6-C18 lactams, preferably C10-C18, and more preferably C10-C12. C6-C12 lactams include decanolactam, undecanolactam, and lauryllactam in particular.

[0041] If the at least one semicrystalline aliphatic polyamide is obtained from the polycondensation of at least one lactam, the semicrystalline aliphatic polyamide may therefore comprise a single lactam or a plurality of lactams.

[0042] Advantageously, the at least one semicrystalline aliphatic polyamide is obtained from the polycondensation of a single lactam, the lactam being selected from lauryl lactam and undecanolactam, and preferably lauryl lactam.

[0043] If the at least one semicrystalline aliphatic polyamide is obtained from the polycondensation of at least one amino acid, the at least one amino acid may be selected from C6-C18 amino acids, preferably C10-C18 amino acids, and more preferably C10-C12 amino acids.

[0044] C6-C12 amino acids include, in particular, 6-aminohexanoic acid, 9-aminononanoic acid, 10-aminodecanoic acid, 10-aminoundecanoic acid, 12-aminododecanoic acid and 11-aminoundecanoic acid, as well as their derivatives, especially N-heptyl-11-aminoundecanoic acid.

[0045] If the at least one semicrystalline aliphatic polyamide is obtained from the polycondensation of at least one amino acid, the semicrystalline aliphatic polyamide may therefore contain a single amino acid or a plurality of amino acids.

[0046] Advantageously, the semicrystalline aliphatic polyamide is obtained from the polycondensation of a single amino acid, the amino acid being selected from 11-aminoundecanoic acid and 12-aminododecanoic acid, and preferably 11-aminoundecanoic acid.

[0047] When the at least one semicrystalline aliphatic polyamide is obtained by polycondensation of at least one C4-C36, preferably C5-C18, preferably C5-C12, more preferably C10-C12 diamine Xa and at least one C4-C36, preferably C6-C18, preferably C6-C12, more preferably C10-C12 diacid Yb, then the at least one diamine Xa is an aliphatic diamine and the at least one diacid Yb is an aliphatic diacid.

[0048] The diamine may be linear or branched. Advantageously, the diacitor is linear.

[0049] The at least one C4-C36 diamine Xa may be selected from, in particular, 1,4-butanediamine, 1,5-pentamethylenediamine, 1,6-hexamethylenediamine, 1,7-heptamethylenediamine, 1,8-octamethylenediamine, 1,9-nonameethylenediamine, 1,10-decamethylenediamine, 1,11-undecamethylenediamine, 1,12-dodecamethylenediamine, 1,13-tridecamethylenediamine, 1,14-tetradecamethylenediamine, 1,16-hexadecamethylenediamine, and 1,18-octadecamethylenediamine, octadecenediamine, eicosanediamine, docosanediamine, and diamines obtained from fatty acids.

[0050] Advantageously, the at least one diamine Xa is C5-C18 and is selected from 1,5-pentamethylenediamine, 1,6-hexamethylenediamine, 1,7-heptamethylenediamine, 1,8-octamethylenediamine, 1,9-nonameethylenediamine, 1,10-decamethylenediamine, 1,11-undecamethylenediamine, 1,12-dodecamethylenediamine, 1,13-tridecamethylenediamine, 1,14-tetradecamethylenediamine, 1,16-hexadecamethylenediamine, and 1,18-octadecamethylenediamine.

[0051] Advantageously, the at least one C5-C12 diamine Xa is selected from, in particular, 1,5-pentamethylenediamine, 1,6-hexamethylenediamine, 1,7-heptamethylenediamine, 1,8-octamethylediamine, 1,9-nonamethylediamine, 1,10-decamethylenediamine, 1,11-undecamethylediamine, and 1,12-dodecamethylediamine.

[0052] Advantageously, the at least one C6-C12 diamine Xa is selected from, in particular, 1,6-hexamethylenediamine, 1,7-heptamethylenediamine, 1,8-octamethylediamine, 1,9-nonamethylediamine, 1,10-decamethylenediamine, 1,11-undecamethylediamine, and 1,12-dodecamethylediamine.

[0053] Advantageously, the diamine Xa used is a C10-C12 diamine, and is particularly selected from 1,10-decamethylenediamine, 1,11-undecamethylediamine, and 1,12-dodecamethylediamine.

[0054] The at least one C4-C36 dicarboxylic acid Yb may be selected from succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, undecanediic acid, dodecanediic acid, brassic acid, tetradecanediic acid, pentadecanediic acid, hexadecanedioic acid, octadecanediic acid, and diacides obtained from fatty acids.

[0055] The diacitor may be linear or branched. Preferably, the diacitor is linear.

[0056] Advantageously, the at least one dicarboxylic acid Yb is C6-C18 and is selected from adipic acid, suberic acid, azelaic acid, sebacic acid, undecanediic acid, dodecanediic acid, brassic acid, tetradecanediic acid, pentadecanediic acid, hexadecanedioic acid, and octadecanediic acid.

[0057] Advantageously, the at least one dicarboxylic acid Yb is C6-C12 and is selected from adipic acid, suberic acid, azelaic acid, sebacic acid, undecanediic acid, and dodecanediic acid.

[0058] Advantageously, the at least one dicarboxylic acid Yb is C10-C12 and is selected from sebacic acid, undecanediic acid, and dodecanediic acid.

[0059] If the semicrystalline aliphatic polyamide is obtained from the polycondensation of at least one diamine Xa and at least one dicarboxylic acid Yb, the semicrystalline aliphatic polyamide may therefore comprise a single or multiple diamines and a single or multiple dicarboxylic acid.

[0060] Advantageously, the semicrystalline aliphatic polyamide is obtained from the polycondensation of a single diamine Xa and a single dicarboxylic acid Yb.

[0061] The at least one semi-aromatic semi-crystalline polyamide is obtained from the polycondensation of at least one diamine Xa as defined above with at least one aromatic dicarboxylic acid, or from the polycondensation of diamine Xb with the dicarboxylic acid Yb as defined above.

[0062] The aromatic dicarboxylic acid is advantageously selected from terephthalic acid (represented by T), isophthalic acid (represented by I), and 2,6-naphthalenedicarboxylic acid (represented by N), or mixtures thereof, and is particularly selected from terephthalic acid (represented by T), isophthalic acid (represented by I), or mixtures thereof.

[0063] Diamine Xb is preferably an arylamine and may be selected from meta-xylylenediamine (MXD, CAS No.: 1477-55-0) or para-xylylenediamine (PXD, CAS No.: 539-48-0).

[0064] If the semicrystalline semi-aromatic polyamide is obtained from the polycondensation of at least one diamine Xa and at least one aromatic dicarboxylic acid, or from the polycondensation of at least one diamine Xb and at least one dicarboxylic acid Yb, then the semicrystalline semi-aromatic polyamide may thus comprise a single or multiple diamines and a single or multiple dicarboxylic acid.

[0065] Advantageously, the semicrystalline aliphatic polyamide is obtained from the polycondensation of a single diamine Xa and a single aromatic dicarboxylic acid, or from the polycondensation of a single diamine Xb and a single dicarboxylic acid Yb.

[0066] Advantageously, the semi-crystalline semi-aromatic polyamide is obtained by polycondensation of at least one diamine Xa with at least one dicarboxylic acid selected from terephthalic acid and isophthalic acid, particularly terephthalic acid, or the semi-aromatic semi-crystalline polyamide is obtained by polycondensation of at least one diamine Xb with at least one dicarboxylic acid Yb.

[0067] The at least one C6-C12 diamine Xa is selected in particular from 1,6-hexamethylenediamine, 1,7-heptamethylenediamine, 1,8-octamethylediamine, 1,9-nonamethylediamine, 1,10-decamethylenediamine, 1,11-undecamethylediamine, and 1,12-dodecamethylediamine. The at least one dicarboxylic acid is an acid selected from terephthalic acid and isophthalic acid, particularly terephthalic acid.

[0068] In particular, the at least one diamine Xb may be an arylamine selected from meta-xylylenediamine (MXD, CAS number: 1477-55-0) or para-xylylenediamine (PXD, CAS number: 539-48-0), and the at least one dicarboxylic acid Yb is C6-C18 and selected from adipic acid, suberic acid, azelaic acid, sebacic acid, undecanediic acid, dodecanediic acid, brassic acid, tetradecanediic acid, pentadecanediic acid, hexadecanedioic acid, and octadecanediic acid.

[0069] Advantageously, the at least one dicarboxylic acid Yb is C6-C12 and is selected from adipic acid, suberic acid, azelaic acid, sebacic acid, undecanediic acid, and dodecanediic acid.

[0070] Each of these semi-aromatic polyamides can be copolymerized with lactams or amino acids to give structures such as PA11 / 9T, PA11 / 10T, PA11 / 12T, PA12 / 9T, PA12 / 10T, and PA12 / 12T, or PA11 / MXD6, PA11 / MXD10, PA12 / MXD6, and PA12 / MXD10.

[0071] Advantageously, the composition of layer (1) comprises a polyamide resin comprising at least 60% by weight, particularly at least 70% by weight, especially at least 80% by weight, and more specifically at least 90% by weight, of the total weight of the composition, consisting of at least one first polyamide resin mainly comprising aliphatic units and at least one second resin mainly comprising aromatic units.

[0072] The composition of layer (1) consists of at least 50% recycled material from multilayer pipes that were used for transporting automotive fluids.

[0073] This means that the entire “at least one dominant polyamide” in the composition corresponds to what is called “at least 50% recycled material,” or that at least 50% by weight of the total components of the composition consists of recycled material derived from a mixture of multilayer tubes.

[0074] The recycled material may be obtained from multi-layer tubes used for transporting automotive fluids. Thus, the tubes are used tubes, i.e., those that have been used for at least one year to transport the fluids defined above.

[0075] The multilayer tube comprises at least one layer made of a composition comprising a semicrystalline aliphatic polyamide and optionally an impact modifier and / or additive, and at least one layer comprising a blend of semicrystalline aliphatic and semicrystalline aromatic polyamides and optionally an impact modifier and / or additive. Thus, the multilayer tube comprises other layers made of thermoplastic polymers other than semicrystalline aliphatic polyamide or a blend of semicrystalline aliphatic and semi-aromatic semicrystalline polyamide, such as polypropylene, semi-aromatic polyamide, or polyethylene vinyl alcohol (EVOH).

[0076] It is also clear that a multilayer tube can be a blend of different types of multilayer tubes, provided that at least one layer of one of several types of multilayer tubes consists of a semicrystalline aliphatic polyamide.

[0077] When the mixing tubes are incompatible with each other, it is represented by B, and C B =C C -1, C is preferred B =C C The mixed tubes can be made compatible by adding a second semicrystalline aliphatic polyamide having an average number of carbon atoms per nitrogen atom represented by -2, preferably a third polyamide.

[0078] The multilayer tubes used for transporting automotive fluids and therefore now considered used can undergo several different processes to be recycled. Multilayer tubes can be simply cut in half. The multilayer tubes can be cut and resynthesized. That is, after cutting, the cut particles are fed into an extruder, particularly a twin-screw or buss extruder, where they are remixed by melting. The molten material is discharged from the extruder in rod form, cooled, and cut into pellets. The multilayer tubes can be fragmented, resynthesized, and recombined. That is, after fragmentation, the fragmented particles are fed into an extruder as defined above, where they are remixed by adding and melting semicrystalline aliphatic polyamide of regenerated or non-regenerated origin, at least one compound selected from at least one impact modifier, plasticizer, additive, and antistatic loading material. The molten material is discharged from the extruder in rod form, cooled, and cut into pellets.

[0079] Optionally, multi-layer pipes for transporting automotive fluids undergo a washing and / or cleaning process before being cut.

[0080] Optionally, severed pipes undergo a washing and / or cleaning process after being severed.

[0081] Optionally, multilayer tubes for transporting automotive fluids may undergo a washing and / or cleaning process before cutting, and then optionally, a washing and / or cleaning process after cutting and before recombination.

[0082] The cleaning process may be carried out, for example, under reduced pressure.

[0083] In one embodiment, the composition of layer (1) is C C at least 50% by weight, particularly 50 - 99% by weight, especially 50 - 98% by weight of at least one semi-crystalline aliphatic polyamide represented by C, having an average number of carbon atoms per nitrogen atom represented by 6 - 18, preferably 8 - 12; C B =C C -1, preferably C B =C C -2, and having an average number of carbon atoms per nitrogen atom represented by B, and at least one semi-crystalline aliphatic polyamide of 0 - 50% by weight; C A =C B -1, preferably C A =C B -2, and having an average number of carbon atoms per nitrogen atom represented by A, and a semi-crystalline aliphatic polyamide of 0 - 50% by weight; 0 - 45% by weight of at least one impact modifier, particularly 1 - 45% by weight of at least one impact modifier, especially 2 - 45% by weight of at least one impact modifier, 0 - 20% by weight of at least one plasticizer, 0 - 2% by weight of at least one additive and the sum of the components is equal to 100%. The sum of the components is equal to 100%.

[0084] In another embodiment, the composition of layer (1) is C C at least 50% by weight, particularly 50 - 99% by weight, especially 50 - 98% by weight of at least one semi-crystalline aliphatic polyamide represented by C, having an average number of carbon atoms per nitrogen atom represented by 6 - 18, preferably 8 - 12; C B =C C -1, preferably C B =C CHaving an average number of carbon atoms per nitrogen atom represented by -2, and containing at least one semicrystalline aliphatic polyamide represented by B in an amount of 0-25% by weight; C A =C B -1, preferably C A =C B A semicrystalline aliphatic polyamide having an average number of carbon atoms per nitrogen atom represented by -2, and represented by A, in a weight of 0-25%; At least one impact modifier in 0-45% by weight, particularly at least one impact modifier in 1-45% by weight, particularly at least one impact modifier in 2-45% by weight, 0-20% of at least one plasticizer, 0-2% by weight of at least one additive and It consists of, The sum of the components equals 100%.

[0085] The polyamides represented by A, B, and C may be of recycled or non-recycled origin, provided that the composition of layer (1) consists of at least 50% recycled material.

[0086] Advantageously, the Tm of the dominant semicrystalline aliphatic polyamide of layer (1) is less than 225°C, particularly less than 200°C, when determined according to ISO 11357-3:2013 at a heating rate of 20 K / min.

[0087] In one embodiment, the composition of layer (1) does not contain plasticizers and / or impact modifiers, and the recycled material is derived from tubing selected from tubing that has been cut, tubing that has been cut and resynthesized, and tubing that has been cut, resynthesized, and recombined.

[0088] In another embodiment, the composition of layer (1) comprises at least one compound selected from plasticizers, impact modifiers, and additives, and the recycled material is selected from tubing that has been shredded, then resynthesized and recombined.

[0089] In one embodiment, the fluid transported by the multilayer tube is different from the fluid in the multilayer tubular structure (MLT).

[0090] In other words, if the multilayer tube is transporting a fluid such as air, the multilayer tubular structure (MLT) may be intended to transport gasoline, or if the multilayer tube is transporting a fluid such as alcohol-mixed gasoline, the multilayer tubular structure (MLT) may be intended to transport diesel.

[0091] In another embodiment, the fluid transported by the multilayer tube is the same as that of the multilayer tubular structure (MLT).

[0092] In other words, if a multilayer tube transports a fluid such as gasoline, and the gasoline in the multilayer tube and the multilayer tubular structure (MLT) is the same, for example, an alcohol-blended gasoline, then the tubular structure (MLT) may be intended to transport gasoline.

[0093] Advantageously, the recycled material is derived from multilayer tubes such as PA11 / / PPA9T and PA12 / / PPA9T or PA11 / / MXD6 and PA12 / / MXD6.

[0094] In one embodiment, the composition of layer (1) comprises at least 60% by weight, particularly at least 70% by weight, particularly at least 80% by weight, particularly at least 90% by weight, and more particularly at least 95% recycled material.

[0095] In another embodiment, the composition of layer (1) consists of 100% by weight of recycled material.

[0096] Used multilayer tubes that are recycled In the first modified example, the pipe for transporting automotive fluids is multilayered and simply fragmented, and the composition of the layer (1) obtained by the regeneration is C CA polyamide represented by C, having an average number of carbon atoms per nitrogen atom of 6 to 18, preferably 8 to 12, in at least 61% by weight, particularly 96% to 99% by weight, especially 96% to 98% by weight, and at least one semicrystalline semiaromatic polyamide; 0-2% of at least one plasticizer, 0-2% by weight of at least one additive, especially a stabilizer; It consists of, The sum of the components equals 100%.

[0097] Advantageously, in this first variant, the semicrystalline aliphatic polyamide represented by C is selected from PA612, PA1012, PA1010, PA11 and PA12, in particular PA11, and the semicrystalline semi-aromatic polyamide is selected from PA9T, PA10T, PA12T, MXD6 and MXD10.

[0098] Advantageously, in this first modification, the pipe was for transporting fuel, such as gasoline, in particular alcohol-blended gasoline, bio-gasoline, or diesel, in particular biodiesel.

[0099] Advantageously, in this first modification, the semicrystalline aliphatic polyamide represented by C was selected from PA612, PA1012, PA1010, PA11 and PA12, particularly PA11, and the semicrystalline semi-aromatic polyamide was selected from PA9T, PA10T, PA12T, MXD6 and MXD10, and the tube was for transporting fuel, such as gasoline, particularly alcohol-blended gasoline, bio-gasoline, or diesel, particularly biodiesel.

[0100] In the second modified example, the pipe for transporting automotive fluids is multilayered, fragmented, and recombined, and the composition of the layer (1) obtained from the recombination is C CA polyamide represented by C, having an average number of carbon atoms per nitrogen atom of 6 to 18, preferably 8 to 12, in at least 61% by weight, particularly 96% to 99% by weight, especially 96% to 98% by weight, and at least one semicrystalline semiaromatic polyamide; 0-2% of at least one plasticizer, 0-2% by weight of at least one additive, especially a stabilizer; It consists of, The sum of the components equals 100%.

[0101] Advantageously, in this second variant, the semicrystalline aliphatic polyamide represented by C is selected from PA612, PA1012, PA1010, PA11 and PA12, particularly PA11, and the semicrystalline semi-aromatic polyamide is selected from PA9T, PA10T, PA12T, MXD6 and MXD10.

[0102] Advantageously, in this second modification, the pipe was for transporting fuel, such as gasoline, in particular alcohol-blended gasoline, bio-gasoline, or diesel, in particular biodiesel.

[0103] Advantageously, in this second modification, the semicrystalline aliphatic polyamide represented by C was selected from PA612, PA1012, PA1010, PA11 and PA12, particularly PA11, and the semicrystalline semi-aromatic polyamide was selected from PA9T, PA10T, PA12T, MXD6 and MXD10, and the tube was for transporting fuel, such as gasoline, particularly alcohol-blended gasoline, bio-gasoline, or diesel, particularly biodiesel.

[0104] In the third modified example, the pipe for transporting automotive fluids is multilayered, fragmented, recombined, and recombined, and the composition of the layer (1) obtained from the recombination and recombination is C CA semicrystalline aliphatic polyamide represented by C, having an average number of carbon atoms per nitrogen atom of 6 to 18, preferably 8 to 12, and a semicrystalline semiaromatic polyamide in an amount of at least 58.5% by weight; 6-14%, especially 6-8%, of at least six plasticizers; 0-1.5% by weight of at least one additive, especially a stabilizer; It consists of, The sum of the components equals 100%.

[0105] Advantageously, in this third variant, the semicrystalline aliphatic polyamide represented by C is selected from PA612, PA1012, PA1010, PA11 and PA12, particularly PA11, and the semicrystalline semi-aromatic polyamide is selected from PA9T, PA10T, PA12T, MXD6 and MXD10.

[0106] Advantageously, in this third modification, the pipe was for transporting fuel, such as gasoline, in particular alcohol-blended gasoline, bio-gasoline, or diesel, in particular biodiesel.

[0107] Advantageously, in this third modification, the semicrystalline aliphatic polyamide represented by C is selected from PA612, PA1012, PA1010, PA11 and PA12, particularly PA11, and the semicrystalline semi-aromatic polyamide is selected from PA9T, PA10T, PA12T, MXD6 and MXD10, and the tube was for transporting fuel, such as gasoline, particularly alcohol-blended gasoline, bio-gasoline, or diesel, particularly biodiesel.

[0108] In the fourth modified example, the pipe for transporting automotive fluids is multilayered, fragmented, recombined, and recombined, and the composition of the layer (1) obtained from the recombination and recombination is C CA semicrystalline aliphatic polyamide and a semicrystalline semiaromatic polyamide, represented by C, having an average number of carbon atoms per nitrogen atom of 6 to 18, preferably 8 to 12; 6-14%, especially 6-8%, of at least six plasticizers; 1-2% by weight of at least one additive, particularly stabilizers and catalysts; It consists of, The sum of the components equals 100%.

[0109] Advantageously, in this fourth variant, the semicrystalline aliphatic polyamide represented by C is selected from PA612, PA1012, PA1010, PA11 and PA12, particularly PA11, and the semicrystalline semi-aromatic polyamide is selected from PA9T, PA10T, PA12T, MXD6 and MXD10.

[0110] Advantageously, in this fourth modification, the pipe was for transporting fuel, such as gasoline, in particular alcohol-blended gasoline, bio-gasoline, or diesel, in particular biodiesel.

[0111] Advantageously, in this fourth modification, the semicrystalline aliphatic polyamide represented by C is selected from PA612, PA1012, PA1010, PA11 and PA12, particularly PA11, and the semicrystalline semi-aromatic polyamide is selected from PA9T, PA10T, PA12T, MXD6 and MXD10, and the tube was for transporting fuel, such as gasoline, particularly alcohol-blended gasoline, bio-gasoline, or diesel, particularly biodiesel.

[0112] Advantageously, the composition is degassed during synthesis, and even more advantageously, the degassing is performed immediately after the molten zone and before the zone in which a plasticizer such as BBSA is introduced.

[0113] In the fifth modified example, the pipe for transporting automotive fluids is multilayered, fragmented, recombined, and recombined, and the composition of the layer (1) obtained from the recombination and recombination is C C A semicrystalline aliphatic polyamide and at least one semicrystalline semiaromatic polyamide, represented by C, having an average number of carbon atoms per nitrogen atom of 6 to 18, preferably 8 to 12; at least 50% by weight, particularly 50% to 99% by weight, especially 50% to 98% by weight; C B =C C -1, preferably C B =C C Having an average number of carbon atoms per nitrogen atom represented by -2, and containing at least one semicrystalline aliphatic polyamide represented by B in an amount of 0-25% by weight; C A =C B -1, preferably C A =C B A semicrystalline aliphatic polyamide having an average number of carbon atoms per nitrogen atom represented by -2, and represented by A, in a weight of 0-25%; 0-2% of at least one plasticizer, 0-2% by weight of at least one additive and It consists of, The sum of the components equals 100%.

[0114] Advantageously, in this fifth variant, the semicrystalline aliphatic polyamide represented by C is selected from PA612, PA1012, PA1010, PA11 and PA12, in particular PA11, and the semicrystalline semi-aromatic polyamide is selected from PA9T, PA10T, PA12T, MXD6 and MXD10.

[0115] Advantageously, in this fifth modification, the pipe was for transporting fuel, such as gasoline, in particular alcohol-blended gasoline, bio-gasoline, or diesel, in particular biodiesel.

[0116] Advantageously, in this fifth variant, the semicrystalline aliphatic polyamide represented by C was selected from PA612, PA1012, PA1010, PA11 and PA12, particularly PA11, and the semicrystalline semi-aromatic polyamide was selected from PA9T, PA10T, PA12T, MXD6 and MXD10, and the tube was for transporting fuel, such as gasoline, particularly alcohol-blended gasoline, bio-gasoline, or diesel, particularly biodiesel.

[0117] In the sixth modified example, the pipe for transporting automotive fluids is multilayered, fragmented, recombined, and recombined, and the composition of the layer (1) obtained from the recombination and recombination is C C A semicrystalline aliphatic polyamide and at least one semicrystalline semiaromatic polyamide, represented by C, having an average number of carbon atoms per nitrogen atom of 6 to 18, preferably 8 to 12; at least 55% by weight, particularly 55% to 99% by weight, especially 55% to 98% by weight; At least one impact modifier in 0-45% by weight, particularly at least one impact modifier in 1-45% by weight, particularly at least one impact modifier in 2-45% by weight, It consists of, The sum of the components equals 100%.

[0118] Advantageously, in this sixth variant, the semicrystalline aliphatic polyamide represented by C is selected from PA612, PA1012, PA1010, PA11 and PA12, particularly PA11, and the semicrystalline semi-aromatic polyamide is selected from PA9T, PA10T, PA12T, MXD6 and MXD10.

[0119] Advantageously, in this sixth modification, the pipe was for transporting fuel, such as gasoline, in particular alcohol-blended gasoline, bio-gasoline, or diesel, in particular biodiesel.

[0120] Advantageously, in this sixth variant, the semicrystalline aliphatic polyamide represented by C was selected from PA612, PA1012, PA1010, PA11 and PA12, particularly PA11, and the semicrystalline semi-aromatic polyamide was selected from PA9T, PA10T, PA12T, MXD6 and MXD10, and the tube was for transporting fuel, such as gasoline, particularly alcohol-blended gasoline, bio-gasoline, or diesel, particularly biodiesel.

[0121] In the seventh modification, the pipe for transporting automotive fluids is multilayered, fragmented, recombined, and recombined, and the composition of the layer (1) obtained from the recombination and recombination is C C A semicrystalline aliphatic polyamide and a semicrystalline semiaromatic polyamide, represented by C, having an average number of carbon atoms per nitrogen atom of 6 to 18, preferably 8 to 12; At least one impact-resistant modifier in an amount of 0-43.5% by weight, particularly at least one impact-resistant modifier in an amount of 1-43.5% by weight, particularly at least one impact-resistant modifier in an amount of 2-43.5% by weight, 6-14%, especially 6-8%, of at least six plasticizers; 0-1.5% by weight of at least one additive, especially a stabilizer; It consists of, The sum of the components equals 100%.

[0122] Advantageously, in this seventh variant, the semicrystalline aliphatic polyamide represented by C is selected from PA612, PA1012, PA1010, PA11 and PA12, in particular PA11, and the semicrystalline semi-aromatic polyamide is selected from PA9T, PA10T, PA12T, MXD6 and MXD10.

[0123] Advantageously, in this seventh modification, the pipe was for transporting fuel, such as gasoline, in particular alcohol-blended gasoline, bio-gasoline, or diesel, in particular biodiesel.

[0124] Advantageously, in this seventh variant, the semicrystalline aliphatic polyamide represented by C was selected from PA612, PA1012, PA1010, PA11 and PA12, particularly PA11, and the semicrystalline semi-aromatic polyamide was selected from PA9T, PA10T, PA12T, MXD6 and MXD10, and the tube was for transporting fuel, such as gasoline, particularly alcohol-blended gasoline, bio-gasoline, or diesel, particularly biodiesel.

[0125] In the eighth modified example, the pipe for transporting automotive fluids is multilayered, fragmented, recombined, and recombined, and the composition of the layer (1) obtained from the recombination and recombination is C C A semicrystalline aliphatic polyamide and a semicrystalline semiaromatic polyamide, represented by C, having an average number of carbon atoms per nitrogen atom of 6 to 18, preferably 8 to 12; A combination of at least one impact-resistant modifier in an amount of 0-43% by weight, particularly at least one impact-resistant modifier in an amount of 1-43% by weight, particularly at least one impact-resistant modifier in an amount of 2-38% by weight, 6-14%, especially 6-8%, of at least six plasticizers; 1-2% by weight of at least one additive, particularly stabilizers and catalysts; It consists of, The sum of the components equals 100%.

[0126] Advantageously, in this eighth variant, the semicrystalline aliphatic polyamide represented by C is selected from PA612, PA1012, PA1010, PA11 and PA12, in particular PA11, and the semicrystalline semi-aromatic polyamide is selected from PA9T, PA10T, PA12T, MXD6 and MXD10.

[0127] Advantageously, in this eighth variant, the pipe was for transporting fuel, such as gasoline, in particular alcohol-blended gasoline, bio-gasoline, or diesel, in particular biodiesel.

[0128] Advantageously, in this eighth variant, the semicrystalline aliphatic polyamide represented by C was selected from PA612, PA1012, PA1010, PA11 and PA12, particularly PA11, and the semicrystalline semi-aromatic polyamide was selected from PA9T, PA10T, PA12T, MXD6 and MXD10, and the tube was for transporting fuel, such as gasoline, particularly alcohol-blended gasoline, bio-gasoline, or diesel, particularly biodiesel.

[0129] In the ninth modification, the pipe for transporting automotive fluids is multilayered, fragmented, recombined, and recombined, and the composition of the layer (1) obtained from the recombination and recombination is C C A semicrystalline aliphatic polyamide and a semicrystalline semiaromatic polyamide, represented by C, having an average number of carbon atoms per nitrogen atom of 6 to 18, preferably 8 to 12; C B =C C -1, preferably C B =C C Having an average number of carbon atoms per nitrogen atom represented by -2, and containing at least one semicrystalline aliphatic polyamide represented by B in an amount of 0-25% by weight; C A =C B -1, preferably C A =C B A semicrystalline aliphatic polyamide having an average number of carbon atoms per nitrogen atom represented by -2, and represented by A, in a weight of 0-25%; A combination of at least one impact-resistant modifier in an amount of 0-43% by weight, particularly at least one impact-resistant modifier in an amount of 1-43% by weight, particularly at least one impact-resistant modifier in an amount of 2-38% by weight, 0-20% of at least one plasticizer, 0-2% by weight of at least one additive and It consists of, The sum of the components equals 100%.

[0130] Advantageously, in this ninth variant, the semicrystalline aliphatic polyamide represented by C is selected from PA612, PA1012, PA1010, PA11 and PA12, in particular PA11, and the semicrystalline semi-aromatic polyamide is selected from PA9T, PA10T, PA12T, MXD6 and MXD10.

[0131] Advantageously, in this ninth modification, the pipe was for transporting fuel, such as gasoline, in particular alcohol-blended gasoline, bio-gasoline, or diesel, in particular biodiesel.

[0132] Advantageously, in this ninth modification, the semicrystalline aliphatic polyamide represented by C was selected from PA612, PA1012, PA1010, PA11 and PA12, particularly PA11, and the semicrystalline semi-aromatic polyamide was selected from PA9T, PA10T, PA12T, MXD6 and MXD10, and the tube was for transporting fuel, such as gasoline, particularly alcohol-blended gasoline, bio-gasoline, or diesel, particularly biodiesel.

[0133] Regarding impact resistance modifiers The impact resistance modifiers are advantageously composed of polymers, particularly polyolefins, having a flexural modulus of less than 100 MPa and a Tg of less than 0°C (measured according to ISO 178:2010 standard, determined at relative humidity: RH 50%, 23°C, and the inflection point of a DSC thermogram, measured at a heating rate of 20 K / min, according to standard 11357-2:2013).

[0134] The polyolefin used as an impact resistance modifier may be functionalized or unfunctionalized, or it may be a mixture of at least one functionalized polyolefin and / or as few as one unfunctionalized polyolefin. For simplicity, polyolefins will be denoted as (B) below, and functionalized polyolefins (B1) and unfunctionalized polyolefins (B2) will be described.

[0135] Unfunctionalized polyolefins (B2) are, classically speaking, homopolymers or copolymers of α-olefins or diolefins such as ethylene, propylene, 1-butene, 1-octene, and butadiene. Examples include the following: - Homopolymers and copolymers of polyethylene, particularly LDPE, HDPE, LLDPE (linear low-density polyethylene), VLDPE (very low-density polyethylene), and metallocene polyethylene. - A homopolymer or copolymer of propylene. - Ethylene / α-olefin copolymers, such as ethylene / propylene, EPR (an abbreviation for ethylene-propylene-rubber), and ethylene / propylene / diene (EPDM). - Styrene / ethylene-butene / styrene (SEBS), styrene / butadiene / styrene (SBS), styrene / isoprene / styrene (SIS), styrene / ethylene-propylene / styrene (SEPS) block copolymers. - A copolymer of ethylene and at least one product selected from a salt or ester of an unsaturated carboxylic acid such as alkyl (meth)acrylate (e.g., methyl acrylate), or a vinyl ester of a saturated carboxylic acid such as vinyl acetate (EVA), wherein the ratio of comonomers can reach 40% by weight.

[0136] Functionalized polyolefins (B1) may be polymers of α-olefins having reactive units (functional groups), such reactive units being acids, anhydrides, or epoxy functional groups. Examples include polyolefins (B2) that have been grafted, copolymerized, or terpolymerized by unsaturated epoxides, such as glycidyl (meth)acrylate, or by carboxylic acids or their corresponding salts or esters, such as (meth)acrylic acid (which can be whole or partially neutralized by a metal such as Zn), or by carboxylic acid anhydrides, such as maleic anhydride. Functionalized polyolefins are, for example, PE / EPR mixtures, the weight ratio of which may vary over a wide range, for example between 40 / 60 and 90 / 10, and the mixture is co-grafted with anhydrides, particularly maleic anhydride, at graft rates of, for example, 0.01 to 5% by weight.

[0137] The functionalized polyolefin (B1) may be selected from the following (co)polymers, which are grafted with maleic anhydride or glycidyl methacrylate, with a grafting rate of, for example, 0.01 to 5% by weight. - Copolymers of ethylene and propylene, butene, hexene, or octene, such as PE, PP, and containing 35-80% by weight of ethylene; - Ethylene / α-olefin copolymers, such as ethylene / propylene, EPR (an abbreviation for ethylene-propylene-rubber), and ethylene / propylene / diene (EPDM). - Styrene / ethylene-butene / styrene (SEBS), styrene / butadiene / styrene (SBS), styrene / isoprene / styrene (SIS), styrene / ethylene-propylene / styrene (SEPS) block copolymers. - Ethylene-vinyl acetate copolymer (EVA) containing up to 40% by weight of vinyl acetate; - Ethylene-alkyl (meth)acrylate copolymer containing up to 40% by weight of alkyl (meth)acrylate; - Ethylene vinyl acetate (EVA) and alkyl (meth)acrylate copolymer containing up to 40% by weight of comonomers.

[0138] The functionalized polyolefin (B1) is mainly selected from ethylene / propylene copolymers with maleic anhydride grafted propylene, and may then be condensed with a monoamine polyamide (or polyamide oligomer) (product described in EP-A-0,342,066).

[0139] Furthermore, the functionalized polyolefin (B1) may be a copolymer or terpolymer of at least the following units: (1) ethylene, (2) a vinyl ester of an alkyl (meth)acrylate or saturated carboxylic acid, and (3) an anhydride such as maleic anhydride or (meth)acrylic acid, or an epoxy such as glycidyl (meth)acrylate.

[0140] An example of the latter type of functionalized polyolefin is the following copolymer, where ethylene preferably constitutes at least 60% by weight, and the ter monomer (functional) constitutes, for example, 0.1 to 10% by weight of the copolymer. - Ethylene / alkyl (meth)acrylate / (meth)acrylic acid or maleic anhydride or glycidyl methacrylate copolymer; - Ethylene / vinyl acetate / maleic anhydride or glycidyl methacrylate copolymer; - Ethylene / vinyl acetate or alkyl (meth)acrylate / (meth)acrylic acid or maleic anhydride or glycidyl methacrylate copolymer;

[0141] In the copolymer described above, (meth)acrylic acid may be chlorinated with Zn or Li.

[0142] In (B1) or (B2), the term "(alkyl)(meth)acrylate" refers to C1-C8 alkyl methacrylates and acrylates, which may be selected from methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, ethyl-2-hexyl acrylate, cyclohexyl acrylate, methyl methacrylate, and ethyl methacrylate.

[0143] Furthermore, the aforementioned polyolefin (B1) may be crosslinked by any suitable method or agent (such as a diepoxy, diacid, or peroxide), and the term functionalized polyolefin also includes mixtures of the aforementioned polyolefins with difunctional reagents such as diacids, dianhydrides, or dieps that can react with them, or mixtures of at least two functionalized polyolefins that can react with each other.

[0144] The aforementioned copolymers (B1) and (B2) may be copolymerized statistically or sequentially, and may have a linear or branched structure.

[0145] The molecular weight, MFI index, and density of these polyolefins can also vary considerably, as is understood by those skilled in the art. MFI stands for Melt Flow Index, a measure of fluidity in the molten state. MFI is measured according to ASTM 1238 standard.

[0146] Advantageously, the non-functionalized polyolefin (B2) is selected from polypropylene homopolymers or copolymers, any ethylene homopolymer or copolymer, and higher α-olefin comonomers, such as butene, hexene, octene, or 4-methyl-1-pentene. Examples include PP, high-density PE, medium-density PE, linear low-density PE, low-density PE, and ultra-low-density PE. These polyethylenes are known to those skilled in the art as being produced by the "free radical" method, the "Ziegler" catalyst method, or more recently, the so-called "metallocene" catalyst.

[0147] Advantageously, the functionalized polyolefin (B1) is selected from any polymer comprising α-olefin units and polar reactive units, such as epoxy, carboxylic acid, or carboxylic acid anhydride. Examples of such polymers include terpolymers of ethylene, alkyl acrylate and maleic anhydride or glycidyl methacrylate, e.g., Lotader® of the applicant, or polyolefins grafted with maleic anhydride, e.g., Orevac® of the applicant, and terpolymers of ethylene, alkyl acrylate and (meth)acrylic acid. Homopolymers or copolymers of polypropylene grafted with carboxylic acid anhydride and then condensed with polyamide, or monoamine polyamide oligomers may also be mentioned.

[0148] Regarding additives The additives optionally used in the compositions of the present invention are conventional additives used in polyamides, which are well known to those skilled in the art and are particularly described in EP2098580.

[0149] For example, additives are selected from catalysts, antioxidants, heat stabilizers, UV absorbers, light stabilizers, lubricants, inorganic fillers, flame retardants, nucleating agents and dyes, reinforcing fibers, waxes and mixtures thereof.

[0150] The term "catalyst" refers to polycondensation catalysts such as minerals or organic acids.

[0151] Advantageously, the weight ratio of the catalyst is approximately 50 ppm to 5000 ppm, and particularly 100 to 3000 ppm, relative to the total weight of the composition.

[0152] Advantageously, the catalyst is selected from phosphoric acid (H3PO4), phosphorous acid (H3PO3), hypophosphorous acid (H3PO2), or a mixture thereof.

[0153] As an example, the stabilizer may be a UV stabilizer, an organic stabilizer, or more generally an organic stabilizer such as a phenol antioxidant (e.g., Ciba-BASF's Irganox® 245, 1098, or 1010 type), a phosphate antioxidant (e.g., Ciba-BASF's Irgafos® 126 and Irgafos® 168), and optionally other stabilizers such as HALS (e.g., Ciba-BASF's Tinuvin® 770), meaning a hindered amine light stabilizer, an anti-UV agent (e.g., Ciba's Tinuvin® 312), or a combination of phosphorus-based stabilizers. Amine-based antioxidants such as Crompton's Naugard® 445 or polyfunctional stabilizers such as Clariant's Nylostab® S-EED may also be used.

[0154] This stabilizer may also be a mineral stabilizer, such as a copper-based stabilizer. Examples of such mineral stabilizers include halides and copper acetate. Secondarily, other metals such as silver may be considered, but their effectiveness is known to be low. These copper-based compounds are typically associated with alkali metal halides, particularly potassium.

[0155] Regarding plasticizers As an example, plasticizers are selected from benzenesulfonamide derivatives, such as n-butylbenzenesulfonamide (BBSA); ethyltoluenesulfonamide or N-cyclohexyltoluenesulfonamide; hydroxybenzoic acid esters, such as 2-ethylhexyl parahydroxybenzoate and 2-decylhexyl parahydroxybenzoate; esters or ethers of tetrahydrofurfuryl alcohol, such as oligoethyleneoxytetrahydrofurfuryl alcohol; and esters of citric acid or hydroxymalonic acid, such as oligoethyleneoxymalonate.

[0156] The use of a mixture of plasticizers would not be outside the scope of this invention.

[0157] If additives are present in the composition, the proportion of the additives is advantageously 1 to 20% by weight, particularly 5 to 15% by weight, and preferably 5 to 12% by weight.

[0158] Regarding antistatic fillers The antistatic filler is selected from, for example, carbon black, graphite, carbon fibers, carbon nanotubes, and especially carbon black and carbon nanotubes.

[0159] Regarding layer (2) The terms "semicrystalline polyamide" and "aliphatic" have the same definitions as in layer (1).

[0160] The at least one semicrystalline aliphatic polyamide is obtained in the same manner as described above with respect to layer (1).

[0161] In the first modified form of layer (2), layer (2) does not contain an impact resistance modifier.

[0162] In this case, semicrystalline aliphatic polyamides, such as PA12, PA612, or PA1010, are excluded from the composition of layer (2).

[0163] In a second modification of layer (2), layer (2) comprises 3 to 45% by weight of at least one impact-resistant modifier, particularly 5 to 20% by weight of at least one impact-resistant modifier.

[0164] In one embodiment of this second modified example, the layer (2) is C D At least 50% by weight, particularly 50-97% by weight, especially 50-95% by weight, of at least one semicrystalline aliphatic polyamide represented by D, wherein the average number of carbon atoms per nitrogen atom is 6-18, preferably 9-15; C E =C D -1, preferably C E =C DHaving an average number of carbon atoms per nitrogen atom represented by -2, and comprising at least one semicrystalline aliphatic polyamide represented by E in an amount of 0-25 wt%; C F =C E -1, preferably C F =C E A semicrystalline aliphatic polyamide having an average number of carbon atoms per nitrogen atom represented by -2, represented by F, in a weight of 0-25%; 3 to 45% by weight of at least one impact modifier, particularly 5 to 20% by weight of at least one impact modifier; With 0-20% of at least one plasticizer; 0-2% by weight of at least one additive, 0-35% of at least one antistatic filler and Includes, The sum of the components is equal to 100%. It consists of a composition.

[0165] In another embodiment of this second modification, the layer (2) is C D At least 50% by weight, particularly 50-97% by weight, and especially 50-95% by weight, of at least one semicrystalline aliphatic polyamide represented by D, wherein the average number of carbon atoms per nitrogen atom is 6-18, preferably 9-15; C E =C D -1, preferably C E =C D Having an average number of carbon atoms per nitrogen atom represented by -2, and comprising at least one semicrystalline aliphatic polyamide represented by E in an amount of 0-25 wt%; C F =C E -1, preferably C F =C E A semicrystalline aliphatic polyamide having an average number of carbon atoms per nitrogen atom represented by -2, represented by F, in a weight of 0-25%; 3 to 45% by weight of at least one impact modifier, particularly 5 to 20% by weight of at least one impact modifier; With 0-20% of at least one plasticizer; 0-2% by weight of at least one additive, 0-35% of at least one antistatic filler and It consists of, The sum of the components is equal to 100%. It consists of a composition.

[0166] Advantageously, the composition of layer (2) comprises PA11, PA12, or PA612 and 3 to 45% by weight of an impact modifier, particularly 5 to 20% by weight of an impact modifier.

[0167] Regarding layer (2') The terms "semicrystalline polyamide" and "aliphatic" have the same definitions as in the case of layer (1) or layer (2).

[0168] The at least one semicrystalline aliphatic polyamide is obtained in the same manner as described above for layers (1) and (2).

[0169] In the first modified form of layer (2'), layer (2') does not contain an impact resistance modifier.

[0170] In a second modification of layer (2'), layer (2') comprises 3 to 45% by weight of at least one impact-resistant modifier, particularly 5 to 20% by weight of at least one impact-resistant modifier.

[0171] In one embodiment of this second modified example, the layer (2') is C D At least 50% by weight, particularly 50-97% by weight, especially 50-95% by weight, of at least one semicrystalline aliphatic polyamide represented by D, wherein the average number of carbon atoms per nitrogen atom is 6-18, preferably 9-15; C E =C D -1, preferably C E =C DHaving an average number of carbon atoms per nitrogen atom represented by -2, and comprising at least one semicrystalline aliphatic polyamide represented by E in an amount of 0-25 wt%; C F =C E -1, preferably C F =C E A semicrystalline aliphatic polyamide having an average number of carbon atoms per nitrogen atom represented by -2, represented by F, in a weight of 0-25%; 3 to 45% by weight of at least one impact modifier, particularly 5 to 20% by weight of at least one impact modifier; With 0-20% of at least one plasticizer; 0-2% by weight of at least one additive, 0-35% of at least one antistatic filler and Includes, The sum of the components is equal to 100%. It consists of a composition.

[0172] In another embodiment of this second modification, the layer (2') is C D At least 50% by weight, particularly 50-97% by weight, and especially 50-95% by weight, of at least one semicrystalline aliphatic polyamide represented by D, wherein the average number of carbon atoms per nitrogen atom is 6-18, preferably 9-15; C E =C D -1, preferably C E =C D Having an average number of carbon atoms per nitrogen atom represented by -2, and comprising at least one semicrystalline aliphatic polyamide represented by E in an amount of 0-25 wt%; C F =C E -1, preferably C F =C E A semicrystalline aliphatic polyamide having an average number of carbon atoms per nitrogen atom represented by -2, represented by F, in a weight of 0-25%; 3 to 45% by weight of at least one impact modifier, particularly 5 to 20% by weight of at least one impact modifier; With 0-20% of at least one plasticizer; 0-2% by weight of at least one additive, 0-35% of at least one antistatic filler and It consists of, The sum of the components is equal to 100%. It consists of a composition.

[0173] Advantageously, the composition of layer (2') comprises PA11, PA12, or PA612 and 3 to 45% by weight of at least one impact modifier, particularly 5 to 20% by weight of at least one impact modifier.

[0174] Regarding structures All embodiments of layer (1) described above in the paragraph "Regarding layer (1)" may be used in the structures detailed in this section.

[0175] In one embodiment, layer (1) is located between layer (2) and layer (2').

[0176] Advantageously, the layer (2') is the layer that comes into contact with the fluid being transported.

[0177] Advantageously, layer (2') is as defined for layer (2), and preferably layers (2) and (2') are identical.

[0178] In this latter embodiment, layer (2') is as defined for layer (2), meaning that the compositions of layer (2) and layer (2') may be the same or different.

[0179] If the compositions of layer (2) and layer (2') are different, they may differ in the ratio of polyamide or one of the other components of the composition.

[0180] Advantageously, the composition of layer (2) comprises PA11, PA12, or PA612, and the recycled material is derived from a multilayer tube consisting of a composition comprising PA11 or PA12 and PA9T, PA10T, PA12T, PAMXD6, and PAMXD10, and in particular the composition of layer (1) consists of 100% recycled material.

[0181] Advantageously, the composition of layer (2) comprises PA11, PA12, or PA612, and the recycled material is derived from a multilayer tube consisting of a composition comprising PA11 or PA12 and PA9T, PA10T, PA12T, PAMXD6, and PAMXD10, and in particular the composition of layer (2') comprises PA11, PA12, or PA612.

[0182] Advantageously, the composition of layer (2) comprises PA11, PA12, or PA612 and 3 to 45% by weight of at least one impact modifier, particularly 5 to 20% by weight of at least one impact modifier, and the recycled material is derived from a multilayer tube consisting of a composition comprising PA11 or PA12 and PA9T, PA10T, PA12T, PAMXD6, and PAMXD10, and in particular the composition of layer (1) consists of 100% recycled material.

[0183] Advantageously, the composition of layer (2) comprises PA11, PA12, or PA612 and 3 to 45% by weight of at least one impact modifier, particularly 5 to 20% by weight of at least one impact modifier, and the recycled material is derived from a multilayer tube consisting of a composition comprising PA11, PA12, and PA9T, PA10T, PA12T, PAMXD6, and PAMXD10, in particular the composition of layer (1) is made of 100% recycled material, and the composition of layer (2') comprises PA11, PA12, or PA612 and 3 to 45% by weight of at least one impact modifier, particularly 5 to 20% by weight of at least one impact modifier.

[0184] Advantageously, the compositions of layer (2) and layer (2') are identical, and therefore layers (2) and (2') are clearly identical, and thus both the polyamide and the other components of the composition are essentially identical, and the ratio and thickness of the two layers (2) and (2') are identical. Layer (2') is, in such cases, layer (2).

[0185] In a first variation of the multilayer tubular structure (MLT), the multilayer tubular structure (MLT) consists of three layers (2) / / (1) / / (2'), in particular (2) / / (1) / / (2).

[0186] In one embodiment, there is at least one binder layer (3) located between layer (2) and layer (1) and / or between layer (1) and layer (2').

[0187] In a second variation of the multilayer tubular structure (MLT), the multilayer tubular structure (MLT) consists of four layers (2) / / binder (3) / / (1) / / (2'), in particular (2) / / binder (3) / / (1) / / (2).

[0188] In a third variation of the multilayer tubular structure (MLT), the multilayer tubular structure (MLT) consists of four layers (2) / / (1) / / binder (3) / / (2'), in particular (2) / / (1) / / binder (3) / / (2).

[0189] In a fourth variation of the multilayer tubular structure (MLT), the multilayer tubular structure (MLT) consists of five layers (2) / / binder (3) / / (1) / / binder (3) / / (2'), in particular (2) / / binder (3) / / (1) / / binder (3) / / (2).

[0190] In this fourth modified example, the two binder layers (3) may be the same or different, and in particular, the two binder layers (3) are the same.

[0191] In another embodiment, there is at least one layer of EVOH, the layer (3) being located between layer (1) and layer (2').

[0192] In such cases, the multilayer tubular structure (MLT) consists of four layers (2) / / (1) / / EVOH / / (2'), in particular (2) / / (1) / / EVOH / / (2).

[0193] In one embodiment, the layer (1) accounts for at least 10%, particularly at least 30%, and especially at least 50% of the total thickness of the multilayer tubular structure (MLT).

[0194] Advantageously, the layer (1) accounts for at least 60%, and in particular at least 70%, of the total thickness of the multilayer tubular structure (MLT).

[0195] In one embodiment of four variations of a multilayer tubular structure (MLT) or a four-layer structure having EVOH, the composition of layer (1) lacks polyamides represented by A and B, and the composition of layer (2) comprises polyamides selected from polyamides represented by E and F and mixtures thereof.

[0196] In another embodiment of one of four variations of a four-layer structure having a multilayer tubular structure (MLT) or EVOH, the composition of layer (1) comprises a polyamide selected from polyamides represented by A and B and mixtures thereof, and the composition of layer (2) does not contain polyamides represented by E and F.

[0197] In yet another embodiment of one of four variations of a four-layer structure having a multilayer tubular structure (MLT) or EVOH, the composition of layer (1) comprises a polyamide selected from polyamides represented by A and B and mixtures thereof, and the composition of layer (2) comprises a polyamide selected from polyamides represented by E and F and mixtures thereof.

[0198] In yet another embodiment of one of four variations of a four-layer structure having a multilayer tubular structure (MLT) or EVOH, the composition of layer (1) lacks a polyamide selected from those represented by A and B, and the composition of layer (2) lacks a polyamide represented by E and F.

[0199] Advantageously, in these last four embodiments, layer (1) is derived from a multilayer regenerated tube,

[0200] Advantageously, in these last four embodiments, layer (1) is derived from a multilayer regenerated tube, and only the composition of layer (1) contains at least one impact-resistant modifier.

[0201] Advantageously, in these last four embodiments, layer (1) is derived from a multilayer regenerated tube, and the composition of layer (1) and the compositions of layer (2) and layer (2') each contain at least one impact-resistant modifier.

[0202] In one embodiment, the multilayer tube (MLT) is intended for transporting a fluid selected from fuels, such as gasoline, particularly alcohol-blended gasoline, bio-gasoline, or diesel, particularly biodiesel.

[0203] Regarding binders The binder is described in particular in patents EP1452307, EP1162061, EP1216826, EP0428833, and EP3299165.

[0204] It is suggested that layers (2) and (1) or (1) and (2') are adhered to each other. The binder layer is intended to be inserted between two layers that do not adhere to each other or are difficult to adhere to.

[0205] The binder may include, for example, but is not limited to, compositions based on 50% copolyamide 6 / 12 with Mn 16000 (70:30 by weight) and 50% copolyamide 6 / 12 with Mn 16000 (30:70 by mass), compositions based on maleic anhydride-grafted PP (polypropylene) known as Admer QF551A manufactured by Mitsui Chemicals, PA610 (Mn 30000, as specified elsewhere) and 36% PA6 (Mn 28000) and 1.2% organic stabilizer (0.8% phenol, Great A composition based on Lakes' Lowinox 44B25, 0.2% Ciba's Irgafos 168 phosphate, and 0.2% Ciba's Tinuvin 312 anti-UV agent; PA612 (Mn 29000, separately specified) and 36% PA6 (Mn 28000, separately specified) and 1.2% organic stabilizer (Great Lakes' Lowinox 44B25, 0.2% Ciba's Irgafos 168 phosphate, and 0.2% Ciba's Tinuvin 312 anti-UV agent); PA610 (Mn 30000, separately specified) and 36% PA12 (Mn 358% Ciba's Tinuvin 312 anti-UV agent); A composition based on Lakes' Lowinox 44B25, 0.2% Ciba's Irgafos 168 (a phosphate), and 0.2% Ciba's Tinuvin 312 (an anti-UV agent), comprising 40% PA6 (Mn 28000, as specified separately), 40% PA12 (Mn 35000, as specified separately), 20% functionalized EPR Exxelor VA1801 (Exxon), and 1.2% organic stabilizer (0.8% Great phenol). A composition based on Lakes' Lowinox 44B25, 0.2% Ciba's Irgafos 168 (a phosphate), and 0.2% Ciba's Tinuvin 312 (an anti-UV agent), or a composition of 40% PA6.10 (Mn 30000, as specified separately) and 40% PA6 (Mn 28000, as specified separately), in a weight ratio of 68.5:30:1.The composition may also be based on 20% of an ethylene / ethyl acrylate / anhydrous type impact modifier (MFI6 at 190°C and 2.16 kg) and 1.2% of an organic stabilizer (consisting of 0.8% phenol, Lowinox 44B25 from Great Lakes, 0.2% phosphine, Irgafos 168 from Ciba, and 0.2% UV stabilizer, Tinuvin 312 from Ciba). [Examples]

[0206] The following resins were used in the various compositions of the present invention. PA11: Polyamide 11 with Mn (number-average molecular weight) of 29,000. Its melting temperature is 190°C and its enthalpy of melting is 56 kJ / m2. This PA11 composition contains 0.25% (±0.05%) H3PO4. PA12: Polyamide 12 with a Mn (number-average molecular weight) of 35,000. Its melting temperature is 178°C and its enthalpy of melting is 54 kJ / m2. PA12-B: Polyamide 12 with Mn (number-average molecular weight) 41,000. Its melting temperature is 178°C and its enthalpy of fusion is 54 kJ / m2. PA1012: Polyamide 1012 with Mn (number-average molecular weight) of 27,000. Its melting temperature is 190°C and its enthalpy of melting is 57 kJ / m2. PA612: Polyamide 612 with a Mn (number-average molecular weight) of 29,000. Its melting temperature is 218°C and its enthalpy of fusion is 67 kJ / m2. PA610: Polyamide 610 with a Mn (number-average molecular weight) of 30,000. Its melting temperature is 223°C and its enthalpy of melting is 61 kJ / m2. PA6 is a polyamide 6 with a Mn (number-average molecular weight) of 28,000. Its melting temperature is 220°C and its enthalpy of fusion is 68 kJ / m2. The melting temperature and enthalpy of melting were determined in accordance with ISO 11357-3:2013.

[0207] In the composition of the present invention, the following additives, plasticizers, and impact resistance modifiers were used. Stabilizer: A stabilizer made from 0.8% phenol (Lowinox 44B25, manufactured by Great Lakes) and 20% phosphate (Irgafos 168, manufactured by Ciba). BBSA: BBSA (butylbenzenesulfonamide) plasticizer, Imod refers collectively to polyolefins or other types of impact modifiers, such as PEBA (polyether block amide), core-shell, and silicone. Imod1: Represents Exxon's Exxellor VA1801, 10 kg, MFI9 (230°C or below), functionalized with reactive groups having anhydrous functionality, EPR (0.5-1 mass%). Imod2: An ethylene / ethyl acrylate / anhydrous impact modifier of MFI6 under the conditions of a mass ratio of 68.5 / 30 / 1.5, 190°C, and 2.16 kg. Imod3: An ethylene / butyl acrylate / anhydrous impact modifier with MFI5 under conditions of a mass ratio of 79 / 18 / 3, 190°C, and 2.16 kg.

[0208] The following compositions were used to manufacture the tube according to the present invention. Throughout this document, all percentages are expressed on a weight basis.

[0209] In the case of the compositions referred to as "recy," "recy2," and "recy3" used in the tube layer (1) or counterexample tube of the present invention, the following protocol was used to simulate a deteriorated tube.

[0210] Protocol A: The tube is (artificially) degraded based on a highly reproducible model protocol consisting of placing the tube in air (in the presence of oxygen) at 150°C for 96 hours (4 days) to induce thermal oxidation. This degradation model represents the average thermal oxidation that the tube would undergo if used in a vehicle for 10 years adjacent to a high-temperature engine.

[0211] The results obtained regarding impact, degradation, flexural modulus, adhesion and elongation indicate that Protocol A is representative of the recycled gasoline pipe.

[0212] Special protocol used for the (re)composition of the degraded pipe.

[0213] After degradation, in some cases, the cut pipes can be recomposed according to the following two protocols. Protocol B: Recompose the cut pipe with a Coperion / Werner 40 mm twin-screw extruder at a set value of 70 kg / h, 300 rpm, 270 °C under a degassing condition of -100 mmHg. Protocol B2: Recompose the cut pipe with a Coperion / Werner 40 mm twin-screw extruder at a set value of 70 kg / h, 300 rpm, 270 °C under a strong degassing condition of -660 mmHg.

[0214] The various compositions used for the preparation of the pipes of the present invention are shown below. PA11PL = PA11 + 7% BBSA + 1% stabilizer PA12PL = PA12 + 12% BBSA + 1% stabilizer PA11PL-recy = PA11PL pipe degraded according to Protocol A, cut again and later recycled. PA11PL-recy2 = PA11PL degraded according to Protocol A, cut again, recomposed according to Protocol B2, with 7% BBSA + 0.5% stabilizer added during this recomposition, and later recycled pipe. PA11PL-recy + 50% PA12PL-recy = 50 / 50 mixture of PA11PL-recy and PA12PL-recy granules. PA11PL-recy = PA11PL pipe degraded according to Protocol A, cut again and later recycled. PA11PL4 = PA11 + 12% BBSA + 1% stabilizer PA12HIP-recy3=PA12HIPHL is degraded according to protocol A, re-disassembled, and re-synthesized according to protocol B, during which 6% imod1, 9% BBSA, and 1% stabilizer are added, and the tube is subsequently regenerated. 11NX3 = PA11 + 10% imod2 + 5% PA610 + 5% PA6 + 4% BBSA + 1% stabilizer PA11PL-recy+50%PA11PL = PA11PL-recy and PA11PL granules, a 50 / 50 mixture of recycled and unused material. PA12HIPHL = PA12 + 6%imod1 + 10%BBSA + 1% stabilizer PA11PL-recy=PA12HIPHL is degraded, re-cut, and then regenerated according to Protocol A. PA12HIPHL-recy2=PA12HIPHL is degraded according to protocol A, re-disassembled, and re-synthesized according to protocol B, with 10% BBSA + 5% stabilizer added during this re-synthesis, and the tube is subsequently regenerated. PA12HIP-recy3=PA12HIPHL is degraded according to protocol A, re-disassembled, and re-synthesized according to protocol B, during which 6% imod1, 9% BBSA, and 1% stabilizer are added, and the tube is subsequently regenerated. MLT-cx11-recy=MLT(45 / / 15 / / 40% 11NX3 / / OHhi / / 11NX3) is degraded according to protocol A, re-disassembled, re-synthesized according to protocol B, and subsequently regenerated. MLT-cx21-recy=MLT(80 / 20% 11NX3 / / MXD6hi) is degraded according to protocol A, re-shredded, re-synthesized according to protocol B, and subsequently regenerated. MXD6hi = MXD6 Impact Resistance Improvement Composition = A composition based on MXD6-type copolyamide containing an impact resistance improver (sold by Solvay under the name Ixef BXT-2000). Its melting point is 237°C. MLT-cx11-recy + 20% MLTcx31-recy is a mixture of 80% MLT-cx11-recy and 20% MLT-cx31-recy. MLT-cx31-recy=MLT(15 / 60 / 25% PA12HI2 / / PA11-recyNX3 / / PPA9T) is degraded according to protocol A, re-shredded, re-synthesized according to protocol B, and then regenerated into a tube. PA12HI2 = PA12 - B + 10% imod 1 + 5% BBSA + 1% stabilizer OHhi = Impact-resistant improved EVOH, sold by Eval-Kuraray under the name EVAL LA170B.

[0215] These compositions are produced by conventional synthesis in a co-rotating twin-screw extruder such as Coperion 40 at 300 rpm and 270°C (300°C if the components have a melting point higher than 260°C).

[0216] Multilayer tube of the present invention The layers are listed from outside to inside, followed by the thickness of each layer expressed as a percentage, and the dimensions of the tube are 8*1mm.

[0217] Preparation of multilayer structures (tubes): Multilayer tubes are manufactured by co-extrusion. An industrial Maillefer multilayer extrusion line is used, equipped with five extruders connected to a multilayer extrusion head with a spiral mandrel.

[0218] The screws used are single-screw extrusion screws with a screw profile suitable for polyamide. In addition to five extruders and multi-layer extrusion heads, the extrusion line includes the following: The die-punch assembly is located at the tip of the co-extrusion head; the inner diameter of the die and the outer diameter of the punch are selected according to the structure being manufactured, its constituent materials, as well as the dimensions of the pipe and the line speed. A vacuum tank with an adjustable vacuum level. Water, maintained at a constant 20°C, circulates within the tank, allowing the gauge to be immersed and the tube to be shaped to its final dimensions. The gauge diameter is adjusted to match the dimensions of the tube being manufactured; for a tube with an outer diameter of 8mm and a thickness of 1mm, it is typically 8.5-10mm. A series of cooling tanks, in which water is kept at approximately 20°C, can cool the tubes along the path from the head to the drawing bench; Diameter; A drawing bench.

[0219] A five-extruder configuration is used to manufacture tubes with two to five layers (and single-layer tubes). For structures with fewer than five layers, the same material is fed into multiple extruders.

[0220] Before testing, ensure that the residual moisture content in the extrusion material is less than 0.08% to ensure the best characteristics of the tube and good extrusion quality. If this is not the case, an additional step is performed before testing, in which the material is dried overnight at 80°C, usually in a vacuum dryer.

[0221] The tubes satisfying the characteristics disclosed in this patent application are taken after the extrusion parameters have stabilized and the dimensions of the tubes no longer change over time. The diameter is controlled by a laser diameter meter installed at the end of the line.

[0222] The line speed is typically 20 m / min. Line speed is typically in the range of 5 to 100 m / min.

[0223] The screw speed of an extruder is determined by the thickness of the layer and the diameter of the screw, as is well known to those skilled in the art.

[0224] In general, the temperature of the extruder and tools (head and connector) should be adjusted to be sufficiently higher than the melting point of the composition, thereby maintaining the composition in a molten state and preventing solidification of the composition or blockage of the machine.

[0225] Next, the multilayer tubes manufactured by the above extrusion molding were evaluated according to the following multiple criteria. Flexibility: It refers to the flexural modulus measured in accordance with ISO 178 at 23°C for a tube equilibrated in a climate of 23°C and 50% humidity. Using "+", it represents flexibility that can be evaluated as "good" corresponding to not more than 1000 MPa and exceeding 500 MPa. Using "++", it represents flexibility that can be evaluated as "very good" corresponding to not more than 500 MPa and exceeding 250 MPa. Impact: It refers to the VW-40°C type impact standard VW TL52435 2010. Using "++", it represents impact performance that can be evaluated as "very good" corresponding to a breakage rate of 10% or less. Using "+", it represents impact performance that can be evaluated as "good" corresponding to a breakage rate of more than 10% and not more than 25%. Using "-", it represents impact performance that can be evaluated as "rather bad" corresponding to a breakage rate of more than 25% and not more than 75%. Using "--", it represents impact performance that can be evaluated as "very bad" corresponding to a breakage rate of more than 75%. Deterioration: This refers to durability, that is, the durability of the tube against oxidative deterioration in hot air. After deteriorating the tube in air at 150°C, an impact is given in accordance with the DIN73378 standard. This impact is carried out at -40°C, and the half-life (unit: hour) corresponding to the time when 50% of the tested tubes are broken is shown. A qualitative explanation is attached to this value. Using "++", it represents durability that can be evaluated as "very good" corresponding to a half-life of 200 hours or more. Using "+", it represents durability (resistance to thermal oxidative deterioration) that can be evaluated as "good" corresponding to a half-life of 100 hours or more (less than 200 hours). Using "+-", it represents durability (resistance to thermal oxidative deterioration) that can be evaluated as "acceptable" corresponding to a half-life of 50 hours or more (less than 100 hours). Using "-", it represents durability (resistance to thermal oxidative deterioration) that can be evaluated as "bad" corresponding to a half-life of less than 50 hours.

[0226] When half-life values ​​are expressed with only slight differences, these values ​​are rounded to the nearest 25 hours to account for significant figures that contribute to the accuracy of the evaluation.

[0227] Adhesion: This refers to the adhesive strength. Adhesion is expressed in N / cm units and measured on an 8mm diameter and 1mm thick tube that has been conditioned for at least 15 days at 23°C and 50% relative humidity, ensuring that humidity equilibrium is achieved in the sample.

[0228] This value is for the weakest contact surface, i.e., the contact surface with the weakest adhesion in the multilayer film and therefore the highest risk of delamination. Contact surface delamination is performed by pulling one side at a 90° angle at a speed of 50 mm / min using the following procedure.

[0229] A sample piece is cut from a 9 mm wide tube. Thus, this sample piece is tile-like, with all the layers of the original tube remaining. Using a knife, begin separating the contact surfaces of the two layers to be evaluated. Each of these separated layers is then secured to the jaws of a tensile machine. Detachment is performed by pulling these two layers apart at a speed of 50 mm / min at 180 degrees on both sides. The test piece, and therefore the contact surfaces, are held at a 90-degree angle to the direction of tension.

[0230] Use the following notation. +++: Very good, over 50 ++: Good, over 20 and under 50 +: Fairly good (acceptable), above 10 and below 20 -: Bad, below 10

[0231] Elongation %: Except for the measurement being taken on a tube with a diameter of 8 mm and a thickness of 1 mm, this is the elongation at the break point according to ISO R527 standard. The sample is prepared under ISO conditions, that is, it is prepared at 23°C and 50% relative humidity for 15 days or more to achieve humidity equilibrium in the sample.

[0232] Use the following notation. +++: Excellent, over 200% elongation ++: Good, growth rate of 100 or more but less than 200% +: Insufficient: Elongation less than 100%

[0233] The results are shown in Table 1. TIFF2026136117000001.tif95170

Claims

1. A multilayer tubular structure (MLT) for transporting automotive fluids, particularly air, oil, water, urea solution, glycol-based coolant, or fuel, such as gasoline, particularly alcohol-blended gasoline, bio-gasoline, or diesel, particularly biodiesel, or hydrogen, comprising at least three layers: The composition comprises at least one layer (1) consisting of at least 50% polyamide resin, which comprises at least one first polyamide resin mainly containing aliphatic units and at least one second resin mainly containing aromatic units. The composition consists of at least 50% recycled material from multilayer tubes that transported the automotive fluids defined above, and the tube comprises a layer (1) made of a composition mainly comprising at least one polyamide, The material comprises at least one layer (2) consisting mainly of a composition comprising at least one semicrystalline aliphatic polyamide and optionally at least one impact modifier. If layer (2) consists of a composition mainly comprising at least one semicrystalline aliphatic polyamide which is PA12 and / or PA612 and / or PA1010, then the composition comprises the impact resistance modifier, layer (2) and At least one layer (2') consisting of a composition mainly comprising at least one semicrystalline aliphatic polyamide and Includes, The layer (2) and the layer (2') each consist of at least 90% non-recycled material. Multilayer tubular structure.

2. The multilayer tubular structure (MLT) according to claim 1, wherein layer (1) is located between layer (2) and layer (2').

3. The multilayer tubular structure (MLT) according to claim 1 or 2, wherein layer (2') is a layer that comes into contact with the fluid.

4. A multilayer tubular structure (MLT) according to any one of claims 1 to 3, wherein layer (2') is as defined for layer (2), and preferably layer (2) and (2') are the same.

5. A multilayer tubular structure (MLT) according to any one of claims 1 to 4, wherein at least one binder layer (3) is present, and the layer (3) is located between layer (2) and layer (1) and / or between layer (1) and layer (2').

6. The multilayer tubular structure (MLT) according to any one of claims 1 to 5, wherein the layer (1) accounts for at least 10%, particularly at least 30%, and especially at least 50% of the total thickness of the multilayer tubular structure (MLT).

7. The layer (1) consists of a composition, and the composition is C Ｃ The average number of carbon atoms per nitrogen atom represented by is 6 to 18, preferably 8 to 12, and is represented by C, with at least 50% by weight, particularly 50 to 97% by weight, of at least one semicrystalline aliphatic polyamide; C Ｂ = C Ｃ -1, preferably C Ｂ = C Ｃ Having an average number of carbon atoms per nitrogen atom represented by -2, and comprising at least one semicrystalline aliphatic polyamide represented by B in an amount of 0-25% by weight; C Ａ = C Ｂ −1, preferably C Ａ = C Ｂ having an average number of carbon atoms per nitrogen atom represented by C = C − 2, and 0 to 25% by weight of a semi-crystalline aliphatic polyamide represented by A; A combination of 0 to 45% by weight of at least one impact modifier, particularly 3 to 45% by weight of at least one impact modifier; A plasticizer in an amount of 0 to 20% by weight of at least one plasticizer, 0-2% by weight of at least one additive and Includes, The sum of the components is equal to 100%. A multilayer tubular structure (MLT) according to any one of claims 1 to 6.

8. A multilayer tubular structure (MLT) according to any one of claims 1 to 7, wherein the recycled material is derived from a multilayer tube selected from a fragmented multilayer tube, a fragmented and resynthesized multilayer tube, and a multilayer tube that has been fragmented, resynthesized, and recombined.

9. The multilayer tubular structure (MLT) according to claim 8, wherein the composition of layer (1) does not contain a plasticizer and / or an impact-resistant modifier, and the recycled material is derived from a multilayer tube selected from a fragmented multilayer tube, a fragmented and resynthesized multilayer tube, and a fragmented, resynthesized and recombined multilayer tube.

10. The multilayer tubular structure (MLT) according to claim 8, wherein the composition of layer (1) comprises at least one compound selected from plasticizers, impact modifiers, and additives, and the recycled material is derived from a multilayer tube selected from a multilayer tube that has been fragmented, then resynthesized and recombined.

11. A multilayer tubular structure (MLT) according to any one of claims 1 to 10, wherein the fluid transported by the multilayer tube is the same as that of the multilayer tubular structure (MLT).

12. A multilayer tubular structure (MLT) according to any one of claims 1 to 10, wherein the fluid transported by the multilayer tube is different from that of the multilayer tubular structure.

13. Layer (2) consists of a composition, and the composition is C Ｄ The average number of carbon atoms per nitrogen atom represented by is 6 to 18, preferably 9 to 15, and is at least 50% by weight, particularly 50 to 97% by weight, and especially 50 to 95% by weight, of at least one semicrystalline aliphatic polyamide represented by D; C Ｅ = C Ｄ -1, preferably C Ｅ = C Ｄ A semicrystalline aliphatic polyamide having an average number of carbon atoms per nitrogen atom represented by -2, and represented by E, in an amount of 0 to 50% by weight, and containing at least one such polyamide; C Ｆ = C Ｅ -1, preferably C Ｆ = C Ｅ A semicrystalline aliphatic polyamide having an average number of carbon atoms per nitrogen atom represented by -2, represented by F, in a weight of 0 to 50%; A combination of 3 to 45% by weight of at least one impact-resistant modifier, particularly 5 to 20% by weight of at least one impact-resistant modifier; A plasticizer in an amount of 0 to 20% by weight of at least one plasticizer, At least one additive in 0-2% by weight, 0-35% of at least one antistatic filler and Includes, The sum of the components is equal to 100%. A multilayer tubular structure (MLT) according to any one of claims 1 to 12.

14. The multilayer tubular structure (MLT) according to claim 13, wherein the composition of layer (1) does not contain polyamides represented by A and B, and the composition of layer (2) contains polyamides selected from polyamides represented by E and F and mixtures thereof.

15. The multilayer tubular structure (MLT) according to claim 14, wherein the composition of layer (1) comprises a polyamide selected from polyamides represented by A and B and mixtures thereof, and the composition of layer (2) does not contain polyamides represented by E and F.

16. A multilayer tubular structure (MLT) according to any one of claims 13 to 15, wherein the polyamide of layer (1) is obtained from a recycled multilayer tube.

17. A multilayer tubular structure (MLT) according to any one of claims 1 to 16, wherein the Tm of the dominant semicrystalline aliphatic polyamide of layer (1) is 225°C or less, particularly 200°C or less, as determined by DSC in accordance with ISO 11357-3:2013 at a heating rate of 20 K / min.

18. A multilayer tubular structure (MLT) according to any one of claims 1 to 17, wherein the dominant semicrystalline aliphatic polyamide of layer (1) has a crystallization enthalpy of 25 J / g or more, preferably 40 J / g or more, and particularly 45 J / g or more, as determined by DSC in accordance with ISO 11357-3:2013 at a heating rate of 20 K / min.

19. A multilayer tubular structure (MLT) according to any one of claims 1 to 18, wherein the MLT consists of the following three structural layers: (2) / / (1) / / (2).

Images