Long-chain polyamide tubes for land and marine applications with improved barrier properties.

Abstract

This invention relates to a multilayer hollow body, particularly a multilayer polyamide pipe, with improved barrier effect against hydrogen permeation.

Description

[Technical Field]

[0001] The present invention relates to a multilayer hollow body in which the permeability of, for example, hydrogen (H2), hydrogen sulfide (H2S), carbon dioxide (CO2), and methane (CH4) is reduced by selecting the molding material used for each layer. It is preferable that the permeability of hydrogen (H2) is reduced. This multilayer hollow body is mainly a hollow-shaped material, such as a pipe, or a container for the conduction or storage of a liquid or gaseous medium. [Background technology]

[0002] Multilayered hollow structures are used particularly in offshore pipes or onshore pipes, or as part of corresponding offshore or onshore pipelines. Offshore pipes are typically laid on the seabed or in trenches beneath it, while onshore pipes are laid on land. By combining offshore and onshore pipes to form pipelines, liquid or gaseous media can be transported over long distances both underwater and on land. Known offshore and onshore pipes are typically made of steel.

[0003] In the primary energy sector, political motivations have led to increased emphasis on the transmission and storage of renewable, climate-neutral energy carriers and climate-detrimental gases, while conventional steel pipe infrastructure has become a significant safety engineering consideration. In particular, hydrogen embrittlement (HE) of austenitic steel and welded joints is a problem that must be addressed with increased technological effort, especially when hydrogen (H2) has a lower energy density than natural gas / methane and therefore requires higher pressures to compensate. This necessitates systems that can meet the presented hydrogen permeation requirements, which cannot be met by conventional pipe materials.

[0004] Hydrogen embrittlement refers to a change in the strength, or more precisely, brittleness, of a metal caused by the penetration and intercalation of hydrogen (H2) into the metal lattice. This corrosion is similar to material fatigue. As a result, it leads to hydrogen-induced fracture, which limits the use of hydrogen-sensitive materials, particularly in hydrogen storage and / or hydrogen conduction applications.

[0005] Prior art has disclosed multilayer hollow bodies, particularly pipes, equipped with metal barrier layers such as aluminum, but these require high manufacturing and material costs to protect against hydrogen. Such pipes are known, for example, as polymer composite pipes or "reinforced thermoplastic pipes" (RTPs).

[0006] Furthermore, these known multilayer hollow bodies are at risk of "cover blow-off" under very high pressures. This is because, over time, the so-called "tortoise effect" allows hydrogen to penetrate the aluminum winding layer beneath the unwelded polymer coating, causing the hydrogen partial pressure to increase over time. This can lead to the coating of the hollow body delaminating.

[0007] RTP is used only in high-voltage areas and is currently only used on land.

[0008] Thermoplastic composite pipes (TCPs) are also known. These are reinforced composite multilayer pipes and do not have the risk of "cover blow-off." Although hydrogen permeability is reduced, it is not as low as non-adhesive onshore RTPs with an aluminum layer.

[0009] Thus, the hollow bodies known from conventional technology are not satisfactory in all respects. [Overview of the project] [Problems that the invention aims to solve]

[0010] Therefore, the object of the present invention is to provide a hollow body that has advantages over known hollow bodies. [Means for solving the problem]

[0011] This objective is achieved by the subject matter described in the claims.

[0012] Surprisingly, in the field of "unreinforced land (maximum 18 bar)," it was found that using the multilayer hollow body according to the present invention, manufactured by co-extrusion, provides manufacturing and cost advantages compared to RTP. Furthermore, in land-based applications, it may be possible to avoid hydrogen embrittlement compared to steel.

[0013] Surprisingly, in the marine sector, it was found that TCPs certified based on PA12 standards provide even better barrier effects.

[0014] Even more surprisingly, in a multilayer pipe concept using polyamide (PA), particularly PA6 and PA6.12 (i.e., PA6 / PA612 mixture)-based adhesion promoters, it was found that using an ethylene vinyl alcohol copolymer (EVOH) barrier layer could optimize the hydrogen permeability of high molecular weight chain-extended large pipe extruded products / polyamide molded materials based on polyamide, particularly PA12, during the co-extrusion process.

[0015] Even more surprisingly, it was found that the pipe composite still functioned mechanically even when the EVOH barrier layer was positioned significantly off-center, for example, as the innermost layer directly interacting with hydrogen. This layer is typically located very close to the center of small-diameter pipes.

[0016] Even more surprisingly, the adhesion mechanism of PA6 and PA6.12-based adhesion promoter compositions was found to also act on chain-extended PA compounds / polyamides. Of particular note is that, depending on the composition, compatibilization may not be necessary.

[0017] By using the chain-extended PA12 compound in combination with the EVOH barrier layer, hydrogen flow can be transported more effectively, and there is a particular advantage in reducing hydrogen permeation.

[0018] In particular, the present invention enables large-diameter onshore and offshore polyamide pipes in many applications, ranging from non-reinforced systems for onshore hydrogen applications (MOP: 16 bar or 18 bar) to 100% green hydrogen-reinforced pipes (thermoplastic composite pipes (TCP) and reinforced thermoplastic pipes (RTP)) for high-pressure-class offshore applications. MOP is an abbreviation for "Maximum Operating Pressure". This is the maximum allowable operating pressure at which the system can be operated permanently under normal operating conditions.

[0019] Polyamide is not inherently susceptible to HE. Therefore, HE is excluded from the start, just like "conventional" corrosion. The requirements for hydrogen permeation into the environment are reliably met by the function of the EVOH barrier layer. The relevant context here is "secondary greenhouse gas emissions". Hydrogen indirectly has an adverse effect on the climate because it stabilizes other direct greenhouse gases such as methane gas and carbon dioxide for longer periods and increases their concentration in the atmosphere. Political efforts towards "zero-permeation solutions" are expected.

[0020] Even in a geometric embodiment with an extremely thin EVOH barrier layer (~0.3 mm) with a total diameter of 50 mm or more and a wall thickness of 3 mm or more, surprisingly, it significantly reduces hydrogen permeation while ensuring mechanical system performance equivalent to that of a monolithic pipe. Even when the thickness of the EVOH barrier layer is less than 0.3 mm, for example 0.1 mm, it significantly reduces hydrogen permeation compared to a monolithic pipe. When thicker layers (up to 0.8 mm) were also tested, no difference in mechanical performance was observed.

[0021] Further potential for use is conceivable in supercritical carbon dioxide transport, which is quite a challenge for steel. Other applications include the transport of multiphase fluids (e.g., hydrogen sulfide, carbon dioxide, methane) with high requirements for the barrier effect.

[0022] Furthermore, the multilayer hollow body can be easily processed and wound, and can be wound particularly at diameters relevant to industry.

[0023] According to the present invention, the pipe structure can be configured more flexibly, and the arrangement and shape of the EVOH barrier layer can be optimized according to the pipe structure / other layers.

[0024] Furthermore, according to the multilayer hollow body of the present invention, specific requirements for the molding material regarding the ratio of layer thickness to diameter can be taken into consideration in the co-extrusion process used in the manufacture of the molding material. These requirements include melt stiffness, residence time, adhesion, and the composition of a small volume EVOH barrier layer + small volume adhesion promoting layer + large volume support layer PA (12, 6.12, etc.).

[0025] Figure 1 shows the hydrogen permeability of the selected polymer and PA12-EVOH-MLT system.

[0026] Figure 2 shows the PA12-EVOH-MLT-TCP concept for 100% hydrogen high-pressure applications in marine use.

[0027] Figure 3 shows a PA12-EVOH gas pipe concept for land-based applications with MOP16 and 18 bar pressures.

[0028] Figure 4 shows the welded test specimen.

[0029] Figure 5 compares the tensile strength characteristics of welded and unwelded samples of single-layer and multi-layer pipes.

[0030] Figure 6 shows a water-wash resistance test of an MLT pipe having an EVOH barrier layer on the inside.

[0031] In the first embodiment, the present invention is A multilayer hollow body, particularly a multilayer hollow body for transporting, transmitting, distributing and / or storing gases and / or liquids, from the inside outwards. - Layer I comprising a molding material containing polyethylene (PE), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA), poly(tetrafluoroethylene-perfluoromethyl vinyl ether) (MFA), fluoroethylene propylene (FEP), and / or ethylene-chlorotrifluoroethylene (ECTFE), preferably comprising high-purity PE, high-purity PVDF, high-purity PFA, high-purity MFA, and / or high-purity FEP, or comprising only these (HP = high purity), - Layer II, which is an adhesion promoting layer and comprises a molding material containing PA6, PA6.12, copolymers thereof, and / or mixtures thereof, or comprising only this molding material, - A barrier layer (Layer III) comprising a molding material containing ethylene-vinyl alcohol copolymer (EVOH), or comprising only this molding material, - A bonding-promoting layer (layer IV) comprising a molding material containing PA6, PA6.12, copolymers thereof, and / or mixtures thereof, or solely this molding material, - A layer V comprising a molding material containing at least one chain-extended polyamide, preferably containing chain-extended PA12, chain-extended PA6.12, chain-extended bio-PA, copolymers thereof, and / or mixtures thereof, particularly preferably containing chain-extended PA12 or containing only this, Layer V obtained using a chain extension additive having at least two carbonate units per molecule of the chain-extended polyamide, - If necessary, layer VI may include a molding material containing carbon fiber reinforced PA12, or consist solely of this molding material. - If necessary, protective coating layer VII and This relates to a multilayer hollow body that includes or contains only these layers.

[0032] The multilayer hollow body is preferably configured for transporting, transmitting, distributing, and / or storing gases and / or liquids.

[0033] Layer I or layer II is in direct contact with the medium to be transported or stored, preferably hydrogen.

[0034] The barrier layer (layer III) functions particularly as a barrier against hydrogen permeation. In the absence of layer I and layer II, layer III is in direct contact with the medium to be transported or stored, preferably hydrogen.

[0035] The high purity inner layer is characterized in that when in contact with the medium, the medium components ( "extracts") leaching from the inner layer are at most trace amounts. Furthermore, these extremely low leaching levels are negligible due to the high purity of the medium to be transported in view of the original purpose.

[0036] A person skilled in the art can determine an acceptable leaching level according to the individual case.

[0037] For example, a person skilled in the art can determine the acceptable level of impurities in hydrogen (H2) for a fuel cell that does not reduce the function of the fuel cell.

[0038] The multilayer hollow body preferably has a gas permeability (G), preferably hydrogen permeability, in the temperature range of 20 °C to 100 °C of 200 cm 3 / m 2 ·d·bar or less, or 300 cm <第 3 / m 2 ·d·bar or less, or 400 cm 3 / m 2 ·d·bar or less, or 500 cm 3 / m 2 ·d·bar or less, or 1000 cm 3 / m 2 ·d·bar or less, and preferably in each case measured in accordance with Part 1 of DIN 53380.

[0039] The barrier layer (layer III) preferably has a gas permeability (G), preferably hydrogen permeability, in the temperature range of 20 °C to 100 °C of 200 cm 3 / m 2 ·d·bar or less, or 300 cm 3 / m2 d-bar or less, or 400cm 3 / m 2 • d bar or less, or 500cm 3 / m 2 d-bar or less, or 1000cm 3 / m 2 The bar is less than or equal to d-bar, and preferably in all cases measured in accordance with DIN 53380 Part 1.

[0040] If the hollow body according to the present invention contains a molding material containing carbon fiber reinforced PA12, or has a layer VI containing only this molding material, it is preferably a unidirectional (UD) fiber-reinforced endless tape having a carbon fiber content of 40-50 volume% and a low viscosity PA12 content of 40-60 volume%. Particularly preferably, these unidirectional fiber-reinforced endless tapes have a carbon fiber content of about 45 volume% and a low viscosity PA12 content of about 55 volume%. The diameter of the carbon fibers is preferably 4-15 μm, particularly preferably 7-12 μm. The PA12 preferably has a melt viscosity in the range of 10-100 Pa·s, measured using an Anton Paar MCR 502 rheometer with an interplate system (plate spacing d=25 mm) at a temperature of 280 °C and an angular frequency of 1000 / min.

[0041] The thickness of layer III (wall) is preferably, -0.2 mm or more, or at least 0.3 mm or more, or 0.4 mm or more, or 0.5 mm or more, and / or -0.6 mm or less, or 0.7 mm or less, or 0.8 mm or less, or 0.9 mm or less, or 1.0 mm or less.

[0042] The (wall) thickness of layer IV is preferably, -0.1 mm or larger, or 0.12 mm or larger, or 0.15 mm or larger, or 0.17 mm or larger, and / or -0.2 mm or less, or 0.22 mm or less, or 0.24 mm or less, or 0.30 mm or less, or 0.5 mm or less.

[0043] The thickness of the V layer (wall) is preferably, - 5.0 mm or more, or 6.0 mm or more, or 7.0 mm or more, or 8.0 mm or more, or 9.0 mm or more, and / or -10.0 mm or less, or 11.0 mm or less, or 12.0 mm or less, or 13.0 mm or less, or 15.0 mm or less.

[0044] Methods for determining the appropriate (wall) thickness are known to those skilled in the art, and include calculations using, for example, "Barlow's formula".

[0045] The wall thickness is preferably determined in accordance with the standard DIN EN 13480-3:2017-12.

[0046] The inner diameter (i.e., diameter excluding layers) of the multilayer hollow body according to the present invention, particularly the land and / or marine pipe, is preferably 30 mm or more, or 50 mm or more, and / or 160 mm or less, or 300 mm or less, or 350 mm or less.

[0047] The multilayer hollow body according to the present invention may contain the same or different polyamides (PA) in different layers. Such polyamides and the abbreviations used to describe them are known to those skilled in the art.

[0048] Polyamides particularly suitable for the present invention are those based on lactam and aminocarboxylic acid (Perlon type) or diamine and dicarboxylic acid (nylon type). Furthermore, they may contain branched units derived from tricarboxylic acid, triamine, or polyethyleneimine, for example. Suitable types include, as homopolymers or copolymers, PA6, PA4.6, PA6.6, PA6.10, PA6.6 / 6, PA6 / 6T, PA6.6 / 6T, especially PA6.12, PA10.10, PA10.12, PA12.12, PA6.13, PA10.14, PA11, PA12, or transparent polyamides.

[0049] Suitable transparent polyamides include, for example: - A polyamide of terephthalic acid and a mixture of isomers of 2,2,4- and 2,4,4-trimethylhexamethylenediamine. - Polyamide of isophthalic acid and 1,6-hexamethylenediamine, - Copolyamide of a mixture of terephthalic acid / isophthalic acid and 1,6-hexamethylenediamine - Copolyamide of isophthalic acid, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, and laurolactam or caprolactam. (co)polyamide of -1,12-dodecanediic acid, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, and optionally laurolactam or caprolactam. - Copolyamide of isophthalic acid, 4,4'-diaminodicyclohexylmethane, and laurolactam or caprolactam. Polyamides of -1,12-dodecanediic acid and 4,4'-diaminodicyclohexylmethane, and / or - A copolyamide of a terephthalic acid / isophthalic acid mixture, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, and laurolactam.

[0050] Polyetheramides based on lactams, aminocarboxylic acids, diamines, dicarboxylic acids, and polyetherdiamines and / or polyetherdiols are also preferred.

[0051] PA6 is preferably produced by ring-opening polymerization of caprolactam.

[0052] PA11 is preferably produced by polycondensation of ω-aminoundecanoic acid, and PA12 is obtained by ring-opening polymerization of laurolactam. Numerous types of both polymers are commercially available.

[0053] PA6.10 is preferably produced by known methods by polycondensation of an equal mixture of hexamethylenediamine and 1,10-decanediic acid; PA6.12 is preferably produced by known methods by polycondensation of an equal mixture of hexamethylenediamine and 1,12-dodecanediic acid; and PA10.10 is preferably produced by known methods by polycondensation of an equal mixture of 1,10-decanediamine and 1,10-decanediic acid.

[0054] PA10.12 is preferably produced by polycondensation of an equal mixture of 1,10-decanediamine and 1,12-dodecanediic acid, and PA12.12 is similarly obtained from 1,12-dodecanediamine and 1,12-dodecanediic acid.

[0055] PA6.6 is preferably produced by polycondensation of hexamethylenediamine and adipic acid. Like PA6, numerous varieties are commercially available.

[0056] PA6 / 6.6 is a copolymer condensate obtained using caprolactam, hexamethylenediamine, and adipic acid as monomers.

[0057] It is preferable to use various polyamide mixtures, such as PA12 / PA10.12 or PA12 / PA12.12. These types of mixtures are particularly characterized by excellent low-temperature impact resistance and are described, for example, in European Patent Application Publication No. 0388583.

[0058] Bio-PA is a polyamide based on renewable raw materials. The monomer is preferably obtained all or partly from castor oil.

[0059] Preferably, at least one layer contains a polyamine-polyamide copolymer.

[0060] Polyamine-polyamide copolymers are preferably produced using the following monomers: (a) A polyamine having 4 or more nitrogen atoms, preferably 8 or more, particularly preferably 11 or more, and a number-average molecular weight (Mn) of 146 g / mol or more, preferably 500 g / mol or more, particularly preferably 800 g / mol or more, added to the polyamine-polyamide copolymer in an amount of 0.5 to 25% by weight, preferably 1 to 20% by weight, particularly preferably 1.5 to 16% by weight, and (b) Polyamide-forming monomers selected from lactams, ω-aminocarboxylic acids, and / or equimolar conjugates of diamines and dicarboxylic acids.

[0061] In preferred embodiments, the amino group concentration of the polyamine-polyamide copolymer is in the range of 100 to 2500 mmol / kg.

[0062] These, and further suitable polyamine-polyamide copolymers, as well as methods for producing them, are known to those skilled in the art, for example, from European Patent Application Publication No. 3299165.

[0063] In a preferred embodiment, the multilayer hollow body either does not include layer I, or does not include layers I and II, with layer III serving as both a barrier layer and an inner layer.

[0064] Layer V comprises a molding material containing at least one chain-extended polyamide.

[0065] An example method for chain extension is defined below.

[0066] In a preferred embodiment, the molding material for layer V is obtained by condensation of PA12, PA6.12 and / or bio-PA molding material and a compound having at least two carbonate units. The polyamide portion of PA12, PA6.12 and / or bio-PA molding material contains at least 5 ppm of phosphorus in the form of an acidic compound as a manufacturing result. (a) Before or during compounding, a weak salt is added to the polyamide in an amount of 0.001% to 10% by weight relative to the polyamide. (b) A mixture is prepared of the completed formulation and a compound having at least two carbonate units in an amount of 0.005% to 10% by weight relative to the polyamide.

[0067] In a preferred embodiment, - The polyamide portion contains 20 ppm to 500 ppm of phosphorus in the form of an acidic compound, and / or - The polyamide is mixed with a weak salt in an amount of 0.001 to 5% by weight, preferably 0.01 to 2.5% by weight, particularly preferably 0.05 to 1% by weight, wherein the pKa of the weak acid is preferably 2.5 or higher, and / or the weak salt is preferably an alkali metal salt, an alkaline earth metal salt, a group III metal salt, a group II metal salt, or an ammonium salt, and / or - Polyamides are manufactured using diamines or polyamines as chain transfer agents, and / or - Compounds having at least two carbonate units are used as masterbatches.

[0068] Those skilled in the art are familiar with the method for synthesizing the ends of polyamides according to specifications. This is done using so-called chain transfer agents. In the case of nylon polyamides, this simply involves adding one of the two components in stoichiometric excess. Alternatively, there is a method of adding so-called external chain transfer agents, which can be used for both types of polyamides (Perlon and nylon). In the formation of polyamides, these chain transfer agents may be, for example, diamines or diacids.

[0069] Methods for determining the terminal groups of polyamides are, in principle, known to those skilled in the art. The determination of carboxyl terminal groups is preferably performed by dissolving the polymer in benzyl alcohol and performing an alkaline titration with alcoholic KOH (0.1 mol / L stock solution) against phenolphthalein. The determination of amino terminal groups is preferably performed by dissolving the polyamide in m-cresol at a high temperature. Endpoint detection is performed by potentiometric titration.

[0070] When polyamides are produced using diamines or polyamines, polyamides with an excess of amino-terminated groups are obtained. The concentration of amino-terminated groups can preferably be measured by potentiometric titration. For this purpose, the concentration of amino-terminated groups can be determined, for example, by dissolving 0.2 to 1.0 g of polyamide in a mixture of 50 mL of m-cresol and 25 mL of isopropanol at 50°C to 90°C, adding aminocaproic acid, and then titrating with 0.05 mol of perchloric acid solution.

[0071] These and further methods for producing chain-extended polyamides are known to those skilled in the art from European Patent Application Publication No. 1690890.

[0072] In a preferred embodiment, the molding material for layer V includes a viscosity modifier (i.e., an additive) that increases the molecular weight by extending the chains of polyamide molecules during thermoplastic processing. A preferred variation of the viscosity modifier is polycarbonate in an acid-terminated polyamide. Such a viscosity modifier is commercially available, for example, from Bruggemann Chemical GmbH (Germany) under the name Bruggolen® M1251 (trademark of Bruggemann GmbH & Co KG, Germany), which is a masterbatch of low-viscosity polycarbonate in an acid-terminated polyamide 6.

[0073] Such Bruggolens® can react with amine-modified polyamides, such as amine-modified PA12, during extrusion molding, resulting in polymer chain elongation and an increase in molecular weight.

[0074] In the reaction between an amine-modified polyamide, such as amine-modified PA12, and Bruggolen®, such as Bruggolen® M1251, the proportion of Bruggolen® is preferably less than 2% by weight of the total weight of the amine-modified polyamide and Bruggolen®.

[0075] In a preferred embodiment, the molding material of layer V includes or consists solely of the chain extension PA of the following formula.

[0076] [ka]

[0077] Further methods for chain extension are known to those skilled in the art from International Publication No. 2000 / 066650, European Patent Application Publication No. 2687554, and European Patent Application Publication No. 2610279.

[0078] In preferred embodiments, the polyamide, particularly the polyamide of layer V, is mixed with chain-extending additives such as carbonyl biscaprolactam (CBC), N-N'-terephthaloyl biscaprolactam, bisoxazoline, diisocyanate, capped diisocyanate, carbodiimide, epoxy-functionalized 5-oligomer or polymer, or carbonate unit-based additives.

[0079] A preferred chain extension additive has at least 2 carbonate units per molecule, preferably 5, more preferably 10, even more preferably 20, particularly preferably 30, even more preferably 40, and particularly preferably at least 50 carbonate units.

[0080] Particularly preferred chain extension additives are disclosed in International Publication No. 2000 / 066650, and of particular preference are chain extension additives such as block copolymers represented by the formula PA.PC (wherein PA is polyamide and PC is polycarbonate).

[0081] The polycarbonate has at least 2 carbonate units, preferably 10, more preferably 20, even more preferably 30, particularly preferably 40, and especially preferably at least 50 carbonate units. The polycarbonate has preferably 2 to 100, particularly preferably 30 to 80, and especially preferably 40 to 70 carbonate units.

[0082] The chain extender is present in the masterbatch of the acid-terminated polyamide and reacts with the amine-terminated polyamide.

[0083] The chain extension additive preferably contains 25-75% by weight, more preferably 35-65% by weight, and particularly preferably 45-55% by weight of polycarbonate.

[0084] Such methods for extending polyamide chains are known to those skilled in the art from European Patent Application Publication No. 1690890, International Publication No. 01 / 53382, and International Publication No. 01 / 66643.

[0085] In a preferred embodiment, the following layers are directly continuous. - Layer I, Layer II, Layer III, Layer IV, and Layer V, or - Layer I, Layer II, Layer III, Layer IV, Layer V, Layer VI, and Layer VII, or - Layer III, Layer IV, and Layer V, or - Layers III, IV, V, VI, and VII and / or Layer III is positioned off-center.

[0086] According to the present invention, the term "off-center arrangement" is understood to mean that, starting from an off-center arrangement, the number of layers in the inward direction, i.e., toward the transported medium, does not match the number of layers in the outward direction. Therefore, according to the present invention, it is also possible to arrange two or more layers of a multilayer hollow body off-center.

[0087] In a preferred embodiment, the molding material for layer V is - Additional polyamides, their copolymers, and / or mixtures thereof, - Preferably PA8, PA9, PA10, PA11, PA12, PA4.6, PA6.10, PA6.12, PA6.13, PA6.14, PA6.16, PA8.10, PA8.13, PA9.10, PA9.12, PA10.10, PA10.12, PA10.14, PA10.16, PA10.18, PA12.12, PA DACH.6 (diaminocyclohexane), PA DACH.10, PA DACH.12, PA DACH.10 / 11, PA PACM.6 (4,4-diaminodicyclohexylmethane), PA PACM.10, PA PACM.12, PA MACM.6 (3,3'-dimethyl-4,4'-diaminocyclohexylmethane), PA MACM.10, PA MACM.12, PA6.T (T=terephthalic acid), PA9.T, PA10.T, PA12.T, PA6.I (I=isophthalic acid), PA9.I, PA10.I, PA12.I, PA6.N (2,6-naphthalenedicarboxylic acid), PA10.N, PA12.N, PA MXD.6 (MXD=metoxylendiamine), PA MXD.10, PA MXD.12, PA IPD.6 (isophoronediamine), PA IPD.10, PA IPD.12, PA IND.6 (isononyldiamine, 1,6-diamino-2,4,4-trimethylhexane), PA IND.10, PA IND.12, PA ND.6 (nonyldiamine, 1,6-diamino-2,2,4-trimethylhexane), PA ND.10, PA ND.12, these copolymers, and / or mixtures thereof Includes.

[0088] In a preferred embodiment, - The molding material for layer I contains, in each case individually or in combination, high-purity PE, high-purity PVDF, high-purity PFA, high-purity MFA, and / or high-purity FEP in an amount of at least 80% by weight, preferably at least 85% by weight, particularly preferably at least 90% by weight, based on the total weight of layer I and / or the molding material for layer I, and / or - The molding material for layer V includes chain-extended PA12, chain-extended PA6.12, chain-extended bio-PA, copolymers thereof, and / or mixtures thereof, either individually or in combination, in any case in an amount of at least 50% by weight, preferably at least 60% by weight, particularly preferably at least 65% by weight, and especially preferably at least 70% by weight, based on the total weight of layer V and / or the molding material for layer V.

[0089] In a preferred embodiment, there are adjacent outer layers (layer VIII), optionally further outer layers (layer IX), optionally further outer layers (layer X), and optionally even further outer layers in the outward direction, and each of these layers independently comprises a molding material preferably comprising polyamides, copolymers thereof, and / or mixtures thereof.

[0090] In a preferred embodiment, the multilayer hollow body is windable, particularly to industrial diameters, and preferably a windable pipe.

[0091] In a preferred embodiment, the hollow body consists of 3, 4, 5, 6, or 7 layers.

[0092] The hollow body according to the present invention may consist of five layers in particular if it is necessary to further encapsulate a blocking layer. Encapsulation is understood to mean preventing the substance from leaching or otherwise moving into the surrounding medium and / or the conductive medium.

[0093] In a preferred embodiment, the multilayer hollow body is - Hollow-shaped material, preferably a pipe or container, and / or - Components of the fuel supply system, and / or - Gas conduit pipes, and / or - A land-based pipe and / or a marine pipe, or at least a part thereof.

[0094] The multilayer hollow body according to the present invention is preferably not a brake line, clutch line, cooling water line, cable duct, fuel supply pipe, ventilation duct, or intake pipe.

[0095] The multilayer hollow body according to the present invention is preferably not a component of an automobile.

[0096] In a preferred embodiment, the multilayer hollow body includes or does not include layers I and II, with layer III being a barrier layer and inner layer, layer IV being a molding material containing PA6 and PA6.12, and layer V being a molding material containing chain extension PA12, with no additional outer layers adjacent to it in the outward direction, and if present, layers I, II, III, IV, and V being directly continuous (see Figure 3). This multilayer hollow body is a land pipe and can be welded by common methods, particularly by hot plate welding and / or socket welding.

[0097] In a preferred embodiment, the multilayer hollow body includes or omits layers I and II, with layer III being a barrier layer and inner layer, layer IV being a molding material containing PA6 and PA6.12, layer V being a molding material containing chain-extended PA12, a second outer layer (layer VI) being a molding material containing carbon fiber reinforced PA12 adjacent outward, a third outer layer (layer VII) being a protective coating adjacent outward, and layers I, II, III, IV, V, VI, and VII being directly continuous if present (see Figure 2). This multilayer hollow body is an offshore pipe and is characterized by being weldable by commonly used methods, particularly by hot plate welding and / or socket welding.

[0098] Those skilled in the art will understand that if the multilayer hollow body according to the present invention comprises a layer VI containing a molding material comprising a unidirectional endless fiber-reinforced tape-like carbon fiber-reinforced PA12, the resulting hollow body may be welded by socket welding rather than hot plate welding.

[0099] In a particularly preferred embodiment, the multilayer hollow body is a 3- or 5-layer chain-extended PA multilayer pipe (i.e., a multilayer pipe containing chain-extended polyamide) having a barrier effect against hydrogen permeation, or at least a portion of such pipe, in either case configured for onshore and / or marine applications.

[0100] In a particularly preferred embodiment, the multilayer hollow body is an ocean pipe that includes, or consists of, layers that precisely match the configuration and arrangement shown in Figure 2.

[0101] In a particularly preferred embodiment, the multilayer hollow body is a land pipe that includes or consists only of layers that precisely match the configuration and arrangement shown in Figure 3.

[0102] In preferred embodiments, multilayer hollow bodies, particularly marine pipes and / or land pipes, contain up to 20% by weight, up to 10% by weight, or up to 5% by weight of steel relative to the total weight of the hollow body. Preferably, multilayer hollow bodies, particularly marine pipes and / or land pipes, do not contain steel.

[0103] In a preferred embodiment, layers I and / or II and / or III and / or IV and / or V and / or VI and / or VII each contain their respective molding materials. The terms “layer” and “molding material” may be used as synonyms.

[0104] The polyamide molding material used in accordance with the present invention includes not only the polymer components described but also additional additives as necessary. Considering the definitions further described below, these additional additives include, for example, the following: a) Stabilizers, b) Additional polymers, c) Impact-resistant modifier, d) Plasticizers, e) Pigments and / or dyes, f) Additives that improve conductivity, and g) Processing aids

[0105] A stabilizer in an amount of 2% by weight or less, preferably 1.5% by weight or less, particularly preferably 1.2% by weight or less, and / or A content of 1.5% by weight or less, preferably 1.2% by weight or less, particularly preferably 0.1% to 1% by weight, and / or It is particularly preferable to use an impact-resistant modifier in an amount of 10% by weight or less, preferably 9% by weight or less, and especially preferably 8% by weight or less.

[0106] In preferred embodiments, the molding material contains an effective amount of an oxidative stabilizer, and particularly preferably, an effective amount of an oxidative stabilizer and an effective amount of a copper-containing stabilizer are used in combination. Suitable oxidative stabilizers include aromatic amines, sterically hindered phenols, phosphites, phosphonites, thio synergists, hydroxylamines, benzofuranone derivatives, and acryloyl-modified phenols. Various types of such oxidative stabilizers are commercially available under trade names such as Naugard 445, Irganox 1010, Irganox 1098, Irgafos 168, P-EPQ, or Lowinox DSTDP. The molding material typically contains about 0.01% to about 2% by weight, preferably about 0.1% to about 1.5% by weight, of the oxidative stabilizer.

[0107] The molding material may further contain UV stabilizers / HALS-type light stabilizers. Suitable UV stabilizers are mainly organic UV absorbers, such as benzophenone derivatives, benzotriazole derivatives, oxalanilides, or phenyltriazines. HALS-type light stabilizers are tetramethylpiperidine derivatives, which are inhibitors that act as radical scavengers. It is advantageous to use UV stabilizers and light stabilizers in combination. Various types of both are commercially available, and the dosage should be followed according to the manufacturer's instructions.

[0108] The molding material may further include hydrolysis stabilizers such as carbodiimides or bisoxazolines of monomers, oligomers, or polymers.

[0109] Other examples of polymers that may be present as additives in molding materials include polyetheramides or polytetrafluoroethylene (PTFE).

[0110] Impact-resistant modified rubbers for polyamide molding materials are prior art. They contain functional groups derived from unsaturated functional compounds incorporated into the main chain by polymerization or grafted onto the main chain. The most commonly used are EPM or EPDM rubbers free radical grafted with maleic anhydride. These types of rubbers can also be used in combination with unfunctionalized polyolefins, such as isotactic polypropylene, as described in European Patent Application Publication No. 0683210.

[0111] The use of plasticizers and polyamides is known to those skilled in the art. An overview of plasticizers suitable for polyamides is given in Gachter / Muller, Kunststoffadditive, C. Hanser Verlag, 2nd edition, p. 296.

[0112] Examples of commonly used compounds suitable for use as plasticizers include esters of p-hydroxybenzoic acid having 2 to 20 carbon atoms in the alcohol component, or amides of arylsulfonic acid having 2 to 12 carbon atoms in the amine component, preferably amides of benzenesulfonic acid.

[0113] Suitable plasticizers include, in particular, ethyl p-hydroxybenzoate, octyl p-hydroxybenzoate, i-hexadecyl p-hydroxybenzoate, n-octyltoluenesulfonamide, n-butylbenzenesulfonamide, or 2-ethylhexylbenzenesulfonamide.

[0114] Examples of suitable pigments and / or dyes include carbon black, iron oxide, zinc sulfide, ultramarine, nigrosine, pearlescent pigments, and metallic flakes.

[0115] Examples of additives that enhance conductivity include conductive carbon black or carbon nanotubes.

[0116] Examples of suitable processing aids include paraffin, aliphatic alcohols, fatty acid amides, stearates (e.g., calcium stearate), paraffin wax, montanes, or polysiloxanes.

[0117] Each molding material is manufactured by melting and mixing its individual components in a manner known to those skilled in the art.

[0118] The EVOH in the barrier layer (layer III) is a copolymer of ethylene and vinyl alcohol. The ethylene content in the copolymer is typically 24-44 mol%, preferably 27-38 mol%, and particularly preferably 30-35 mol%. Numerous types are commercially available. According to the prior art, the molding material may contain additional additives in addition to EVOH, as is customary for barrier layer applications. Such additives are generally the know-how of the EVOH supplier.

[0119] In a preferred embodiment, only the barrier layer (layer III) contains EVOH.

[0120] In a preferred embodiment, only the barrier layer (layer III) contains EVOH, and contains only EVOH (EVOH: 100% by weight).

[0121] The EVOH barrier layer is known to those skilled in the art from European Patent No. 1216826.

[0122] When a multilayer hollow body according to the present invention is used to conduct or store flammable liquids, gases, or dust, such as fuel or fuel vapor, it is recommended that at least one of the layers constituting the composite material be conductive. This can be achieved by incorporating conductive additives using methods of the prior art. Examples of usable conductive additives include conductive carbon black, metal flakes, metal powders, metallized glass beads, metallized glass fibers, metal fibers (e.g., stainless steel), metallized whiskers, carbon fibers (including metallized carbon fibers), intrinsically conductive polymers, or graphite fibrils. Various conductive additives can also be used in mixtures.

[0123] Preferably, the conductive layer is in direct contact with the medium to be conductive or stored, 10 9 Ω / sq or less, preferably 10 6 It has a surface resistivity of Ω / sq or less. A method for measuring the resistivity of a multilayer pipe is described in SAE J 2260, November 2004. In this case, the entire corresponding layer is conductive, or it is composed of two sublayers, one of which is conductive and the other is non-conductive. The conductive innermost layer is more preferably layer 1.

[0124] When the multilayer hollow body according to the present invention is implemented as a hollow shaped material (e.g., a pipe) or a container, the body may be further coated with an additional elastomer layer. Both crosslinked rubber compositions and thermoplastic elastomers are suitable for the coating. The coating material can be applied to the multilayer hollow body / component by, for example, co-extrusion, crosshead die extrusion, or by sliding a pre-fabricated elastomer hose onto an extruded multilayer pipe, with or without the use of an additional adhesion promoter. The thickness of the coating material is generally 0.1 to 4 mm, preferably 0.2 to 3 mm.

[0125] Suitable elastomers include chloroprene rubber, ethylene propylene rubber (EPM), ethylene propylene diene rubber (EPDM), epichlorohydrin rubber (ECO), chlorinated polyethylene, acrylate rubber, chlorosulfonated polyethylene, silicone rubber, plasticized PVC, polyether ester amide, or polyether amide.

[0126] The manufacturing of multilayer hollow bodies can be carried out in a single-step or multi-step manner (for example, a multi-step manner as described in U.S. Patent No. 5,554,425), for example, by sandwich molding, co-extrusion molding, co-extrusion blow molding (including, for example, 3D blow molding, extrusion of parisons into open half molds, 3D parison operations, suction blow molding, 3D suction blow molding, and continuous blow molding). If the multilayer hollow body according to the present invention includes a layer VI containing a molding material comprising carbon fiber reinforced PA12, particularly a molding material in the form of a unidirectional endless fiber reinforced tape, then extrusion molding is performed first, followed by winding molding and downstream extrusion molding.

[0127] In a second embodiment, the present invention is - Hollow-shaped material, preferably as a pipe or container, and / or - As a component of a fuel supply system, and / or - As a gas conduit, and / or - Relating to the use of multilayer hollow bodies according to the present invention as onshore pipes and / or offshore pipes, or at least as part thereof.

[0128] The multilayer hollow body according to the present invention is preferably not used as a brake line, clutch line, coolant line, cable duct, refueling station supply pipe, ventilation duct, and / or intake pipe.

[0129] The multilayer hollow body according to the present invention is preferably not used in automobiles.

[0130] In a third embodiment, the present invention relates to a fuel supply device including a multilayer hollow body according to the present invention.

[0131] Fuel supply devices are preferably fuel lines, fuel containers, hydraulic lines, brake lines, clutch lines, cooling water lines, liners for rigid or flexible pipes in the oil or gas extraction industry, or lines for umbilicals.

[0132] In a fourth embodiment, the present invention relates to a fuel supply system including a multilayer hollow body and / or a device according to the present invention.

[0133] The fuel supply equipment is preferably, - Onshore pipelines, offshore pipelines, or a combination thereof.

[0134] A further example of the equipment according to the present invention is a floating wind power plant that preferably generates hydrogen directly on a platform and transports it on land.

[0135] The fuel is preferably hydrogen (H2), hydrogen sulfide, carbon dioxide, methane, or a mixture thereof, and is particularly preferably hydrogen (H2).

[0136] All definitions of multilayer hollow bodies according to the first aspect of the present invention also apply to the second, third, and fourth aspects of the present invention. [Brief explanation of the drawing]

[0137] [Figure 1] Figure 1 shows the hydrogen permeability of the selected polymer and PA12-EVOH-MLT system. [Figure 2] Figure 2 shows the PA12-EVOH-MLT-TCP concept for 100% hydrogen high-pressure applications in marine use. [Figure 3] Figure 3 shows a PA12-EVOH gas pipe concept for land-based applications with MOP16 and 18 bar pressures. [Figure 4] Figure 4 shows the welded test specimen. [Figure 5]Figure 5 compares the tensile strength characteristics of welded and unwelded samples of single-layer and multi-layer pipes. [Figure 6] Figure 6 shows a water-wash resistance test of an MLT pipe having an EVOH barrier layer on the inside. [Examples]

[0138] The present invention will be illustrated by the following experimental examples.

[0139] Figure 1 shows that the hydrogen permeability in the PA12-EVOH-MLT system according to the present invention is significantly reduced compared to monopipes of the same thickness made with different polymer / polymer systems. The gas permeability G is plotted along the y-axis.

[0140] The hydrogen permeability was measured as follows: One end of the pipe was sealed with a blank flange equipped with measuring connections for continuous monitoring of pressure and temperature. After sealing the test pipe, it was filled with the test gas and stored for 4-6 weeks for conditioning. During conditioning, the pipe was kept in contact with the test gas until the plastic was completely saturated with the test gas and a constant permeation rate was established. After the conditioning phase was completed, the pipe was fixed in a dedicated permeation measurement cell and prepared for testing. The measurement cell was an airtight balanced space made of stainless steel that surrounded the pipe over a test length of approximately 30 cm. The measurement cell itself was equipped with two measuring connections for pressure and temperature control, and a connection for sampling. At the start of the measurement, the measurement cell was purged with nitrogen and adjusted to a positive pressure of approximately 100 millibars. Permeated water that penetrated the pipe wall over the test length was captured in the measurement cell. During the testing period, the permeated hydrogen accumulated in the measurement cell. Gas samples were periodically taken from the measurement cell and analyzed by gas chromatography in the laboratory. The gas composition (nitrogen, hydrogen) provided information about the amount of hydrogen permeating through the pipe wall per unit time. The increase in hydrogen concentration within the measurement cell resembled a linear function and reflected the permeation rate. The permeation rate could be measured with sufficient accuracy using at least four measurement points (at constant pressure and temperature). By considering the internal mantle area (permeation area) and partial pressure (absolute value), the gas permeability G was calculated from the permeation rate, and the permeation coefficient (PC) was further calculated from the pipe wall thickness. The hydrogen permeation coefficient was measured at various internal pressures in tests conducted at room temperature (approximately 20°C). In these tests, the plastic pipe was attached only to the seal at the end of the permeation cell (the pipe mantle surface was not supported).

[0141] By including an EVOH barrier layer, we were able to reduce the permeability coefficient (PC) by up to three orders of magnitude in the temperature range relevant to hydrogen applications (30°C to 50°C).

[0142] Figure 2 shows an oceanic pipe. It is composed of the following layers from the inside out. - Layer I: High-purity (HP) inner layer as needed, - Layer II: Additional adhesion promoter as needed (for high-purity inner layer only), - Layer III: Hydrogen barrier (EVOH) as the inner layer, - Layer IV: Adhesion promoter, - Layer V: Chain extension structure pipe, - Layer VI: Pressure-resistant endless reinforcing material, - Layer VII: Protective pipe Layers III to V form an MLP (Multilayer Pipe System) as a liner. Layers I to V form an HP MLP (HP = high purity, MLP = multilayer pipe system) as a liner.

[0143] Figure 3 shows the aerial pipe. It is composed of the following layers from the inside out. - Layer I: High-purity (HP) inner layer as needed - Layer II: Additional adhesion promoter as needed (for high-purity inner layer only), - Layer III: Hydrogen barrier (EVOH) as the inner layer, - Layer IV: Adhesion promoter, - Layer V: Chain extension structure pipe Layers III to V form an MLP (Multilayer Pipe System) as a pressure pipe. Layers I to V form an HP MLP (HP = high purity, MLP = multilayer pipe system) as a pressure pipe.

[0144] Figures 4 and 5 relate to the hot plate welding of land pipes according to Figure 3.

[0145] Figure 4 shows that when the welded specimen is undamaged, EVOH contamination of the weld seam is not optically apparent. In other words, welding does not cause mechanical weakening of the weld seam.

[0146] Figure 5 shows the relative changes in the properties "yield stress," "elongation," and "modulus of elasticity" of welded monopipes (white) and MLT (gray) (i.e., the multilayer pipe system according to the present invention) compared to unwelded PA12 monopipes (0% baseline). According to the present invention, EVOH contamination of welded joints does not occur. Therefore, there is no significant impact on the structural integrity of the welded joints, and the impact remains within the range of the conventional standard deviation.

[0147] As shown in Figure 6, the minimum bending radius (MBR) at 23°C and in the innermost EVOH barrier layer was calculated using FEM simulation.

[0148] [Table 1]

[0149] It must be mentioned that the failure criterion for MBR is pipe buckling. Therefore, the higher the SDR value / thinner the wall thickness, the faster buckling occurs. EVOH has a higher risk of bulging compared to PA12 (1320 MPa and 40 MPa) due to its high rigidity (3800 MPa) and relatively low flow stress (35 MPa). The MBR of a pipe with 110 SDR17 is 1.85 m, which is significantly larger than the MBR of a single-layer pipe of the same dimensions (1.3 m).

Claims

1. A multi-layered hollow body for transporting, transmitting, distributing, and / or storing gases and / or liquids, from the inside outwards. - Layer I comprising a molding material containing polyethylene (PE), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA), poly(tetrafluoroethylene-perfluoromethyl vinyl ether) (MFA), fluoroethylene propylene (FEP), and / or ethylene-chlorotrifluoroethylene (ECTFE), preferably comprising or solely comprising high-purity PE, high-purity PVDF, high-purity PFA, high-purity MFA, and / or high-purity FEP, - If necessary, a bonding-promoting layer comprising a molding material comprising PA6, PA6.12, copolymers thereof, and / or mixtures thereof, or layer II comprising only the molding material, - A barrier layer (layer III) comprising a molding material containing ethylene-vinyl alcohol copolymer (EVOH), or comprising only the molding material said, - A molding material comprising PA6, PA6.12, copolymers thereof, and / or mixtures thereof, or a bonding-promoting layer (layer IV) comprising only the molding material, - A layer V comprising a molding material containing at least one chain-extended polyamide, preferably containing chain-extended PA12, chain-extended PA6.12, chain-extended bio-PA, copolymers thereof, and / or mixtures thereof, particularly preferably a layer V containing chain-extended PA12 or containing only this, The chain-extended polyamide is obtained using a chain-extending additive having at least two carbonate units per molecule, - If necessary, a layer VI comprising a molding material containing carbon fiber reinforced PA12, or consisting solely of the molding material, - If necessary, protective coating layer VII and A multilayer hollow body containing, or containing only, these layers.

2. The molding material of layer V is obtained by condensation of PA12 molding material, PA6.12 molding material, and / or bio-PA molding material with a compound having at least two carbonate units, and the polyamide portion of the PA12 molding material, PA6.12 molding material, and / or bio-PA molding material contains at least 5 ppm of phosphorus in the form of an acidic compound as a manufacturing result. (a) Before or during compounding, a weak salt is added to the polyamide in an amount of 0.001% to 10% by weight, (b) A mixture is produced of the completed formulation and the compound having at least two carbonate units in an amount of 0.005% to 10% by weight relative to the polyamide. The multilayer hollow body according to claim 1.

3. The polyamide portion contains 20 ppm to 500 ppm of phosphorus in the form of an acidic compound, and / or The polyamide is mixed with a weak salt in an amount of 0.001 to 5% by weight, preferably 0.01 to 2.5% by weight, particularly preferably 0.05 to 1% by weight, wherein the pKa of the weak acid is preferably 2.5 or higher, and / or the weak salt is preferably an alkali metal salt, an alkaline earth metal salt, a metal salt of Group III, a metal salt of Group II, or an ammonium salt, and / or The polyamide is produced using a diamine or polyamine as a chain transfer agent, and / or The multilayer hollow body according to claim 2, wherein the compound having at least two carbonate units is used as a masterbatch.

4. It does not include the aforementioned layer I, or The layer I and the layer II are not included, and the layer III is both a barrier layer and an inner layer. A multilayer hollow body according to any one of claims 1 to 3.

5. The aforementioned layer I, layer II, layer III, layer IV, and layer V, or The aforementioned layer I, layer II, layer III, layer IV, layer V, layer VI, and layer VII, or The aforementioned layer III, layer IV, and layer V, or The aforementioned layers III, IV, V, VI, and VII are directly consecutive and / or The aforementioned layer III is positioned off-center, and / or The thickness of layer III is 0.2 mm or more and 0.6 mm or less, the thickness of layer IV is 0.1 mm or more and 0.2 mm or less, and the thickness of layer V is 6.0 mm or more and 10.0 mm or less, and in all cases, preferably measured in accordance with standard DIN EN13480-3:2017-12, and / or The multilayer hollow body according to any one of claims 1 to 4, wherein the inner diameter of the multilayer hollow body, particularly the land pipe and / or marine pipe, is 30 mm or more, or 50 mm or more, and / or 160 mm or less, or 300 mm or less, or 350 mm or less.

6. The molding material of layer V comprises additional polyamides, copolymers thereof, and / or mixtures thereof. Preferably, PA8, PA9, PA10, PA11, PA12, PA4.6, PA6.10, PA6.12, PA6.13, PA6.14, PA6.16, PA8.10, PA8.13, PA9.10, PA9.12, PA10.10, PA10.12, PA10.14, PA10.16, PA10.18, PA12.12, PA DACH. 6 (diaminocyclohexane), PA DACH. 10, PA DACH. 12, PA DACH. 10 / 11, PA PACM. 6 (4,4-diaminodicyclohexylmethane), PA PACM. 10, PA PACM. 12, PA MACM. 6 (3,3'-dimethyl-4,4'-diaminocyclohexylmethane), PA MACM. 10, PA MACM. 12, PA6.T (T = terephthalic acid), PA9.T, PA10.T, PA12.T, PA6.I (I = isophthalic acid), PA9.I, PA10.I, PA12.I, PA6.N (2,6-naphthalenedicarboxylic acid), PA10.N, PA12.N, PAMXD. 6 (MXD = metaxylenediamine), PA MXD. 10, PA MXD. 12, PA IPD. 6 (isophoronediamine), PA IPD. 10, PA IPD. 12, PA IND. 6 (isononyldiamine, 1,6-diamino-2,4,4-trimethylhexane), PA IND. A multilayer hollow body according to any one of claims 1 to 5, comprising PA IND. 12, PA ND. 6 (nonyldiamine, 1,6-diamino-2,2,4-trimethylhexane), PA ND. 10, PA ND. 12, copolymers thereof, and / or mixtures thereof.

7. The molding material of layer I contains, in each case individually or in combination, high-purity PE, high-purity PVDF, high-purity PFA, high-purity MFA, and / or high-purity FEP in an amount of at least 50% by weight, preferably at least 80% by weight, particularly preferably at least 85% by weight, and / or most preferably at least 90% by weight, based on the total weight of layer I and / or the molding material of layer I, and / or In the molding material of layer III, the ethylene content of the EVOH is at least 10% by weight, more preferably 20-50% by weight, more preferably 24-44% by weight, more preferably 27-38% by weight, more preferably 30-35% by weight, and / or The multilayer hollow body according to any one of claims 1 to 6, wherein the molding material of layer V contains chain-extended PA12, chain-extended PA6.12, chain-extended bioPA, copolymers thereof, and / or mixtures thereof, either individually or in combination, in any case in an amount of at least 80% by weight, preferably at least 85% by weight, and particularly preferably at least 90% by weight, based on the total weight of layer V and / or the molding material of layer V.

8. A multilayer hollow body according to any one of claims 1 to 7, manufactured by a single-stage or multi-stage extrusion or co-extrusion method, and optionally in combination with a winding step.

9. A multilayer hollow body according to any one of claims 1 to 8, which is wrapable, particularly wrapable to industrial diameters, and preferably a wrapable pipe.

10. (i) The layer includes or does not include layer I and layer II, and layer III is a barrier layer and an inner layer, The aforementioned layer IV is a molding material containing PA6 and PA6.

12. The aforementioned layer V is a molding material containing chain extension PA12, There is no additional outer layer in the outward direction. If present, layer I, layer II, layer III, layer IV and layer V are directly continuous, Preferably weldable, and particularly preferably weldable by hot plate welding and / or socket welding, or (ii) The layer includes or does not include layer I and layer II, and layer III is a barrier layer and an inner layer, The aforementioned layer IV is a molding material containing PA6 and PA6.

12. The aforementioned layer V is a molding material containing chain extension PA1, Adjacent to the outermost layer is another outer layer (layer VI), which is a molding material containing carbon fiber reinforced PA12. Adjacent to the outermost layer (layer VII), which is a protective covering, If present, the layers I, II, III, IV, V, VI, and VII are directly continuous. A multilayer hollow body according to any one of claims 1 to 9, preferably weldable, and particularly preferably weldable by hot plate welding and / or socket welding.

11. Hollow shaped material, preferably a pipe or container, and / or Components of a fuel supply system, and / or Gas conduit pipes, and / or A multilayer hollow body according to any one of claims 1 to 10, which is a land pipe and / or a marine pipe, or at least a part thereof.

12. The molding material of layer I and / or the molding material of layer II and / or the molding material of layer III and / or the molding material of layer IV and / or the molding material of layer V and / or the molding material of layer VI and / or the molding material of layer VII contains, in each case, an amount preferably up to 50% by weight, preferably up to 40% by weight, particularly preferably up to 35% by weight, and especially preferably up to 30% by weight, based on the total weight of each layer and / or each molding material, and / or A multilayer hollow body according to any one of claims 1 to 11, comprising one or more additional layers selected from a conductive layer and an elastomer coating layer.

13. A multilayer hollow body according to any one of claims 1 to 12, wherein the molding material of layer I and / or the molding material of layer II and / or the molding material of layer III and / or the molding material of layer IV and / or the molding material of layer V and / or the molding material of layer VI and / or the molding material of layer VII are each independent of each other and do not contain a plasticizer.

14. Hollow shaped material, preferably as a pipe or container, and / or As a component of a fuel supply system, and / or As a gas conduit pipe, and / or Use of the multilayer hollow body according to any one of claims 1 to 13 as a land pipe and / or marine pipe, or at least as part thereof.

15. A fuel supply system comprising a multilayer hollow body according to any one of claims 1 to 13, particularly an onshore pipeline, an offshore pipeline, or a combination thereof.

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