Multilayer structures for transporting or storing hydrogen

Abstract

The present invention relates to a multi-layer structure for transporting, distributing and storing hydrogen, comprising, from the inside to the outside, a sealing layer (1) and at least one composite reinforcing layer (2), the innermost composite reinforcing layer being wrapped around the sealing layer (1), the sealing layer consisting essentially of a composition comprising a polyamide thermoplastic polymer PA11, up to 15% by weight of an impact modifier relative to the total weight of the composition, in particular up to 12% by weight of an impact modifier, and up to 1.5% by weight of a plasticizer relative to the total weight of the composition, the composition being devoid of nucleating agents and polyether block amide (PEBA), at least one of the composite reinforcing layers consisting of a fibrous material in the form of continuous fibers impregnated with at least one polymer P2j, where j=1 to m, m being the number of reinforcing layers, in particular a composition comprising mainly an epoxy or epoxide-based resin, the structure being devoid of an outermost layer, adjacent to the outermost composite reinforcing layer being made of a polyamide polymer.

Description

Technical Field

[0001] This patent application relates to a multilayer composite structure for transporting, distributing or storing hydrogen, in particular for distributing or storing hydrogen, and a method for producing the same structure.

Background Art

[0002] Hydrogen tanks are currently attracting a great deal of attention from a number of manufacturers, especially in the automotive sector. One of the required goals is to propose further low-emission vehicles. Therefore, it is aimed to gradually replace internal combustion engine vehicles, such as gasoline or diesel vehicles, with electric or hybrid vehicles including batteries. Batteries are known to be relatively complex vehicle components. Depending on the positioning of the battery in the vehicle, the battery may need to protect it from impacts and from the external environment which can be at extremely high temperatures and variable humidity. It may also be necessary to avoid any risk of fire. Furthermore, it is important that their operating temperature does not exceed 55°C in order not to damage the cells of the battery and to prolong its life. Conversely, for example in winter, it may be necessary to raise the temperature of the battery in order to optimize its operation.

[0003] Furthermore, electric vehicles still suffer from several problems today, namely battery range, the use of rare earth metals in these batteries, non-renewable resources, charging times much longer than the time it takes to fill a tank, and the problem of electricity generation to enable battery charging in various countries.

[0004] Therefore, hydrogen is an alternative to electric batteries since hydrogen can be converted into electricity by a fuel cell and thus supply power to an electric vehicle.

[0005] Hydrogen tanks typically consist of a metal liner (or sealing layer) that must protect hydrogen from permeation. One type of tank that is conceivable is called Type IV, which is based on a thermoplastic liner with a composite wrapped around it.

[0006] The fundamental principle is to separate the two essential functions of sealing and mechanical strength and manage them independently of each other. In this type of tank, the liner (or sealing sheath), made of thermoplastic resin, is combined with a reinforcing structure made of fibers (glass, aramid, carbon), also known as a reinforcing sheath or layer, which allows it to operate at much higher pressures while reducing weight and avoiding the risk of explosion in the event of a severe external attack.

[0007] Liner has a certain principle characteristic: Potential conversion methods include extrusion blow molding, rotational molding, injection molding, or extrusion. Low hydrogen permeability, or in fact, the permeability of the liner, is a crucial factor in limiting hydrogen leakage from the tank. Good mechanical properties (fatigue) at low temperatures (-40 to -70°C), It must be heat resistant up to 120°C.

[0008] In practice, it is necessary to increase the filling rate of the hydrogen tank, which should be roughly equivalent to that of a fuel tank for an internal combustion engine (about 3 to 5 minutes). However, this increase in rate causes the tank to overheat more significantly, then reach a temperature of about 100°C.

[0009] The performance and safety of hydrogen tanks can be evaluated at a European reference laboratory (GasTeF: Hydrogen Tank Test Facility), as described by Galassi et al. (World hydrogen energy conference 2012, Onboard compressed hydrogen storage: fast filing experiments and simulations, Energy Procedia 29 (2012), pp. 192-200).

[0010] The first generation of Type IV tanks used high-density polyethylene (HDPE) based liners.

[0011] However, HDPE has the disadvantage of having too low a melting point and too high a hydrogen permeability, which presents a problem in terms of heat resistance, preventing an increase in tank filling speed.

[0012] Polyamide PA6-based liners have been under development for many years.

[0013] Nevertheless, PA6 has the disadvantage of having low resistance to cold.

[0014] International application WO2016 / 166326 describes a method for fabricating an inner shell of a composite type IV reservoir, which is intended to receive a pressurized fluid and define the extent of an internal cavity containing at least a metallic base, and a subsequent step of depositing a fibrous material on the outer surface of the inner shell to form an outer casing of the tank.

[0015] International application WO95 / 22030 describes a liner for a high-pressure reservoir made of a thermoplastic material, the thermoplastic material being selected from the group consisting of modified nylon 6 and nylon 11.

[0016] French patent application FR2923575 describes a tank for storing fluid under high pressure, comprising metal end pieces at each of its ends along its axis, wherein a liner surrounds the end pieces, and a structural layer made of thermosetting resin-impregnated fibers surrounds the liner.

[0017] International application WO18155491 describes a hydrogen transport component having a three-layer structure, the inner layer comprising a composition of PA11, 15 to 50% impact modifier and 1 to 3% plasticizer, or a composition lacking a plasticizer, the composition having hydrogen barrier properties, good flexibility at low temperatures and durability. However, this structure is suitable for pipes for transporting hydrogen, but not for storing hydrogen.

[0018] Therefore, on the one hand, it is necessary to optimize the matrix of the composite so as to optimize the mechanical strength of the composite matrix at high temperatures, and on the other hand, it is still necessary to optimize the materials including the sealing sheath so as to optimize the operating temperature of the sealing sheath. Thus, any change in the choice of materials of the composition including the sealing liner that is carried out should not cause a significant increase in the manufacturing temperature of this liner (extrusion blow molding, injection molding, rotational molding, etc.) compared to those practiced today. [Overview of the Initiative]

[0019] These problems are solved by providing the multilayer structure of the present invention, which is intended for transporting, distributing, or storing hydrogen.

[0020] Throughout this specification, the terms “liner” and “sealing sheath” have the same meaning.

[0021] The present invention relates to a multilayer structure intended for transporting, distributing, and storing hydrogen, From the inside out, it includes a sealing layer (1) and at least one composite reinforcing layer (2), The innermost said composite reinforcing layer is wound around the periphery of the sealing layer (1), The sealing layer mainly consists of a composition, and the composition is, Thermoplastic polyamide polymer PA11, An impact resistance improver of less than 15% by weight, especially an impact resistance improver of up to 12% by weight, based on the total weight of the composition, Contains a plasticizer of up to 1.5% by weight based on the total weight of the composition, The composition lacks a nucleating agent and a polyether block amide (PEBA), At least one of the said composite reinforcing layers is a composition, which consists of a fibrous material in the form of continuous fibers impregnated with at least one polymer P2j (j = 1 to m, where m is the number of reinforcing layers), specifically a composition mainly containing an epoxy resin or an epoxy-based resin, The structure relates to a multi-layer structure that lacks the outermost layer and is adjacent to the outermost composite reinforcing layer made of a polyamide polymer.

[0022] The inventors have thus unexpectedly found that in the sealing layer, a polyamide thermoplastic polymer PA11 containing a limited ratio of an impact resistance improver and a plasticizer, and in the matrix of the composite wound around the periphery of the sealing layer, by using different polymers, especially an epoxy resin or an epoxy-based resin, it is possible to achieve a structure suitable for transporting, distributing or storing hydrogen, especially up to 120 °C and achieving an increase in the maximum temperature used, and thus it is possible to increase the filling rate of the tank.

[0023] Thermoplastic polymer PA11 (or polyamide 11) is marketed by Arkema and is especially the result of the polycondensation of 11-aminoundecanoic acid.

Brief Description of the Drawings

[0024] [Figure 1]Figure presenting the results of the Charpy impact test with notch at -40 °C according to ISO 179-1:2010 for 4 liners: PA11, PA12, PA6 and PA66 from left to right. [Figure 2] Figure presenting the hydrogen permeability at 23 °C of PA12 and HDPE liners. This is expressed in cc.mm / m2.24h.atm. This may be expressed in cc.25μ / m2.24h.Pa. The permeability then has to be multiplied by 101325. [Figure 3] Figure presenting the results of the Charpy impact test with notch at -40 °C according to ISO 179-1:2010 for PA11 and PA12 liners, with PA11 on the left and PA12 on the right in each group of the histogram. The first group corresponds to 0% plasticizer, the second group corresponds to 7% plasticizer and the last group corresponds to 12% plasticizer.

DETAILED DESCRIPTION OF THE INVENTION

[0025] The "multi-layer structure" should be understood to mean a tank comprising or consisting of several layers, namely one sealing layer and several reinforcing layers, or one sealing layer and one reinforcing layer.

[0026] The multi-layer structure is thus understood to exclude pipes or tubes.

[0027] Polyether block amide (PEBA) is a copolymer having amide units (Ba1) and polyether units (Ba2), said amide units (Ba1) being units obtained from at least one amino acid, or units obtained from at least one lactam, or: - a polycondensation of at least one diamine, said diamine being preferably selected from linear or branched aliphatic diamines, or mixtures thereof, polycondensation - A polycondensation of at least one carboxylic acid diacid, wherein the diacid is preferably selected from linear or branched aliphatic diacids, or mixtures thereof, and corresponds to an aliphatic repeating unit selected from the units XY obtained from the polycondensation. The diamine and the diacid each contain 4 to 36 carbon atoms, preferably 6 to 18 carbon atoms. The polyether unit (Ba2) is derived in particular from at least one polyalkylene ether polyol, in particular from a polyalkylene ether diol.

[0028] Nucleating agents are known to those skilled in the art, and the term refers to substances that, when incorporated into a polymer, form nuclei for the growth of crystals in a molten polymer.

[0029] These can be selected from, for example, microtalc, carbon black, silica, titanium dioxide, and nanoclay.

[0030] In one embodiment, PA6 is excluded from the composition.

[0031] The statement, "The structure lacks an outermost layer and is adjacent to an outermost composite layer made of polyamide polymer," means that the structure lacks a polyamide polymer layer located on top of the outermost composite reinforcement layer.

[0032] In one embodiment, the multilayer structure consists of two layers, a sealing layer and a reinforcing layer.

[0033] The sealing layer is the innermost layer, relative to the composite reinforcement layer, which is the outermost layer.

[0034] The tank may be for mobile storage of hydrogen, i.e., on a truck for transporting hydrogen, on a vehicle for transporting hydrogen and supplying hydrogen-based fuel cells, for example, on a train for supplying hydrogen, or on a drone for supplying hydrogen, but it may also be a tank for fixed storage of hydrogen at a base for distributing hydrogen to vehicles.

[0035] Advantageously, the sealing layer (1) does not leak hydrogen at 23°C, meaning that the hydrogen permeability at 23°C is 500 cc.mm / m at 23°C under 0% relative humidity (RH). 2 It is less than .24h.atm.

[0036] The composite reinforcement layer(s) are wrapped around the sealing layer by polymer-impregnated fiber ribbons (or tapes or rovings), which are deposited, for example, by filament winding.

[0037] If several layers are present, the polymers will be different.

[0038] If the polymer of the reinforcing layer is identical, several layers may be present, but advantageously, a single reinforcing layer is present, and this reinforcing layer has at least one full wrap around the sealing layer.

[0039] This fully automated process, well known to those skilled in the art, makes it possible to select a winding angle for each layer that will give the final structure the ability to withstand internal pressure loads.

[0040] If there is only one sealing layer and one composite reinforcement layer, then a multilayer structure of two layers is formed, and these two layers can be in direct contact with and bonded to each other, in particular because the composite reinforcement layer is wrapped over the sealing layer.

[0041] If a sealing layer and / or several composite reinforcing layers are present, the sealing layer may or may not be bonded to the innermost layer of the composite reinforcing layers.

[0042] Other composite reinforcement layers may or may not be bonded to each other.

[0043] Advantageously, there is only one sealing layer and one reinforcing layer, which do not adhere to each other.

[0044] Advantageously, there is only one PA11 sealing layer and one reinforcing layer, which are not bonded to each other, and the reinforcing layer consists of a fibrous material in the form of continuous fibers impregnated with at least one polymer P2j, more specifically a composition mainly comprising an epoxide resin or epoxide-based resin.

[0045] In one embodiment, there is only one sealing layer and one reinforcing layer, which are not bonded to each other, and the reinforcing layer consists of a fibrous material in the form of continuous fibers impregnated with a composition containing polymer P2j, which is mainly epoxy resin or epoxy-based resin.

[0046] The term "epoxy-based" throughout this specification means that epoxy is equivalent to at least 50% by weight of the matrix.

[0047] Regarding the sealing layer The sealing layer consists of a composition mainly comprising at least one thermoplastic polyamide PA11.

[0048] The term "primarily" means that at least one of the polymers is present in an amount greater than 50% by weight relative to the total weight of the composition and matrix.

[0049] Advantageously, the at least one dominant polymer is present in an amount of more than 60% by weight, more specifically more than 70% by weight, more specifically more than 80% by weight, and more specifically 90% by weight or more, based on the total weight of the composition and matrix.

[0050] The composition may also contain up to 15% by weight of an impact modifier relative to the total weight of the composition and / or plasticizer and / or additives.

[0051] The additives, excluding the nucleating agent, may be selected from other polymers, antioxidants, heat stabilizers, UV absorbers, light stabilizers, lubricants, inorganic fillers, flame retardants, dyes, carbon black, and carbonaceous nanofillers. In particular, the additives, excluding the nucleating agent, may be selected from antioxidants, heat stabilizers, UV absorbers, light stabilizers, lubricants, inorganic fillers, flame retardants, dyes, carbon black, and carbonaceous nanofillers.

[0052] The other polymer may be another semicrystalline thermoplastic polymer or a different polymer, in particular EVOH (ethylene vinyl alcohol).

[0053] Advantageously, the composition mainly comprises the thermoplastic polymer PA11, 0 to less than 15% impact modifier, particularly 0 to 12% impact modifier, 0 to 1.5% plasticizer, and 0 to 5% by weight of additives, and the total amount of the components of the composition is equal to 100%.

[0054] Advantageously, the composition comprises the thermoplastic polymer PA11, 0 to less than 15% impact modifier, particularly 0 to 12% impact modifier, 0 to 1.5% plasticizer, and 0 to 5% by weight of additives, with the totality of the components of the composition equal to 100%.

[0055] Advantageously, the composition mainly consists of the thermoplastic polymer PA11, 0 to less than 15% by weight of an impact modifier, more specifically 0 to 12% by weight of an impact modifier, 0 to 1.5% by weight of a plasticizer, and 0 to 5% by weight of an additive, and the total amount of the constituent components of the composition is equal to 100% by weight.

[0056] Advantageously, the composition comprises the thermoplastic polymer PA11, 0 to less than 15% by weight of an impact modifier, more specifically 0 to 12% by weight of an impact modifier, 0 to 1.5% by weight of a plasticizer, and 0 to 5% by weight of an additive, with the total amount of the constituent components of the composition equal to 100%.

[0057] Advantageously, the composition mainly comprises the thermoplastic polymer PA11, 0.1 to less than 15% impact modifier, particularly 0.1 to 12% impact modifier, 0 to 1.5% plasticizer, and 0 to 5% by weight of additives, with the totality of the components of the composition equal to 100%.

[0058] Advantageously, the composition comprises the thermoplastic polymer PA11, 0.1 to less than 15% of impact modifiers, particularly 0.1 to 12% of impact modifiers, 0 to 1.5% of plasticizers, and 0 to 5% by weight of additives, with the totality of the components of the composition equal to 100%.

[0059] Advantageously, the composition mainly consists of the thermoplastic polymer PA11, 0.1 to less than 15% by weight of an impact modifier, more specifically 0.1 to 12% by weight of an impact modifier, 0 to 1.5% by weight of a plasticizer, and 0 to 5% by weight of an additive, and the total amount of the constituent components of the composition is equal to 100%.

[0060] Advantageously, the composition comprises the thermoplastic polymer PA11, 0.1 to less than 15% by weight of an impact modifier, more specifically 0.1 to 12% by weight of an impact modifier, 0 to 1.5% by weight of a plasticizer, and 0 to 5% by weight of an additive, with the total amount of the constituent components of the composition equal to 100%.

[0061] Advantageously, the composition mainly comprises the thermoplastic polymer PA11, 0.1 to less than 15% impact modifier, particularly 0.1 to 12% impact modifier, 0.1 to 1.5% plasticizer, and 0 to 5% by weight of additives, with the totality of the constituent components of the composition equal to 100%.

[0062] Advantageously, the composition comprises the thermoplastic polymer PA11, 0.1 to less than 15% of impact modifiers, particularly 0.1 to 12% of impact modifiers, 0 to 1.5% of plasticizers, and 0 to 5% by weight of additives, with the totality of the components of the composition equal to 100%.

[0063] Advantageously, the composition mainly consists of the thermoplastic polymer PA11, 0.1 to less than 15% by weight of an impact modifier, more specifically 0.1 to 12% by weight of an impact modifier, 0.1 to 1.5% by weight of a plasticizer, and 0 to 5% by weight of additives, with the total compositional components equal to 100%.

[0064] Advantageously, the composition mainly consists of the thermoplastic polymer PA11, 0.1 to less than 15% by weight of an impact modifier, more specifically 0.1 to 12% by weight of an impact modifier, 0.1 to 1.5% by weight of a plasticizer, and 0 to 5% by weight of additives, with the total compositional components equal to 100%.

[0065] Advantageously, the composition mainly comprises the thermoplastic polymer PA11, 0.1 to less than 15% impact modifier, particularly 0.1 to 12% impact modifier, 0.1 to 1.5% plasticizer, and 0.1 to 5% by weight of additives, and the total amount of the components of the composition is equal to 100%.

[0066] Advantageously, the composition comprises the thermoplastic polymer PA11, 0.1 to less than 15% of impact modifiers, particularly 0.1 to 12% of impact modifiers, 0 to 1.5% of plasticizers, and 0.1 to 5% by weight of additives, with the totality of the components of the composition equal to 100%.

[0067] Advantageously, the composition mainly consists of the thermoplastic polymer PA11, less than 0.1 to 15% by weight of an impact modifier, more specifically 0.1 to 12% by weight of an impact modifier, 0.1 to 1.5% by weight of a plasticizer, and 0.1 to 5% by weight of an additive, and the total amount of the constituent components of the composition is equal to 100%.

[0068] Advantageously, the composition mainly consists of the thermoplastic polymer PA11, less than 0.1 to 15% by weight of an impact modifier, more specifically 0.1 to 12% by weight of an impact modifier, 0.1 to 1.5% by weight of a plasticizer, and 0.1 to 5% by weight of an additive, and the total amount of the constituent components of the composition is equal to 100%.

[0069] In one embodiment, the composition contains 0.1 to less than 15% by weight of an impact modifier, particularly 0.1 to less than 12% by weight of an impact modifier, and more specifically 5 to 12% by weight, based on the total weight of the composition.

[0070] In one embodiment, the composition lacks an impact resistance modifier.

[0071] In this embodiment, the composition thus mainly consists of the thermoplastic polymer PA11, 0 to 1.5% impact modifier, and 0.1 to 5% by weight of additives, and the total amount of the constituent components of the composition is equal to 100%.

[0072] Advantageously, the composition thus consists of the thermoplastic polymer PA11, 0 to 1.5% plasticizer, and 0.1 to 5% by weight of additives, and the totality of the components of the composition is equal to 100%.

[0073] Advantageously, the composition mainly consists of the thermoplastic polymer PA11, 0 to 1.5% plasticizer, and 0.1 to 5% by weight of additives, and the total amount of the constituent components of the composition is equal to 100%.

[0074] In this case, the dominant PA11 is a mixture with another polyamide.

[0075] Advantageously, the composition comprises the thermoplastic polymer PA11, 0 to 1.5% plasticizer, and 0.1 to 5% by weight of additives, with the total compositional components equal to 100%.

[0076] In one embodiment, the composition lacks a plasticizer.

[0077] In this embodiment, the composition thus mainly comprises the thermoplastic polymer PA11, 0.1 to less than 15% of an impact modifier, more specifically 0.1 to 12% of an impact modifier and 0.1 to 5% by weight of additives, and the totality of the components of the composition is equal to 100%.

[0078] Advantageously, the composition thus comprises the thermoplastic polymer PA11, less than 0.1 to 15% of an impact modifier, more specifically 0.1 to 12% of an impact modifier and 0.1 to 5% by weight of additives, and the total amount of the components of the composition is equal to 100%.

[0079] Advantageously, the composition mainly consists of the thermoplastic polymer PA11, 0.1 to less than 15% of an impact modifier, more specifically 0.1 to 12% of an impact modifier, and 0.1 to 5% by weight of additives, with the total compositional components equal to 100%.

[0080] In this case, the dominant PA11 is a mixture with another polyamide.

[0081] Advantageously, the composition mainly consists of the thermoplastic polymer PA11, 0.1 to less than 15% of an impact modifier, more specifically 0.1 to 12% of an impact modifier and 0.1 to 5% by weight of additives, and the total amount of the constituent components of the composition is equal to 100%.

[0082] In yet another embodiment, the composition lacks an impact modifier and a plasticizer.

[0083] In other embodiments, the composition thus mainly comprises the thermoplastic polymer PA11 and 0.1 to 5% by weight of additives, and the totality of the components of the composition is equal to 100%.

[0084] Advantageously, the composition thus consists of the thermoplastic polymer PA11 and 0.1 to 5% by weight of additives, and the totality of the components of the composition is equal to 100%.

[0085] Advantageously, the composition mainly consists of the thermoplastic polymer PA11 and 0.1 to 5% by weight of additives, and the total amount of the constituent components of the composition is equal to 100%.

[0086] In this case, the dominant PA11 is a mixture with another polyamide.

[0087] Advantageously, the composition comprises the thermoplastic polymer PA11 and 0.1 to 5% by weight of additives, and the total amount of the constituent components of the composition is equal to 100%.

[0088] In another embodiment, the composition contains 0.1 to less than 15% by weight of an impact modifier, particularly 0.1 to 12% by weight, and more specifically 5 to 12% by weight of an impact modifier, based on the total weight of the composition, and the composition lacks a plasticizer.

[0089] In another embodiment, the composition contains 0.1 to less than 15% by weight of an impact modifier, particularly 0.1 to less than 12% by weight of an impact modifier, more specifically 5 to 12% by weight, and 0.1 to 1.5% by weight of a plasticizer, based on the total weight of the composition.

[0090] Thermoplastic polymer PA11 The number-average molecular weight (Mn) of the polyamide thermoplastic polymer PA11 is preferably in the range of 10,000 to 85,000, particularly 10,000 to 60,000, preferably 10,000 to 50,000, and even more preferably 12,000 to 50,000. These Mn values ​​can correspond to an intrinsic viscosity of 0.8 or higher when determined in m-cresol according to standard ISO 307:2007, but by changing the solvent (using m-cresol instead of sulfuric acid at a temperature of 20°C).

[0091] The nomenclature is used to define polyamides as described in ISO standard 1874-1:2011 "Plastiques - Materiaux polyamides(PA) pour moulage et extrusion - Partie 1: Designation", particularly on page 3 (Tables 1 and 2), and is well known to those skilled in the art.

[0092] Polyamide PA11 is a homopolyamide, but if the composition of the components of the sealing layer includes a PA11-based copolyamide, and PA11 units are dominant in the copolyamide, i.e., more than 50% by weight, specifically more than 60% by weight, more than 70% by weight, more than 80% by weight, or more than 90% by weight, relative to the total units in the copolyamide or mixture thereof, then the invention does not deviate from the scope of the present invention.

[0093] Advantageously, polyamide PA11 is a homopolyamide.

[0094] Regarding impact resistance modifiers The impact modifier may be any impact modifier, as long as it is a polymer that has a coefficient lower than that of the resin and has good adhesion to the matrix in order to dissipate crack energy.

[0095] The impact resistance modifiers are advantageously composed of polymers, more specifically polyolefins, having a flexural modulus of less than 100 MPa and a Tg (inflection point of a DSC thermogram, measured according to standard 11357-2) below 0°C, as measured according to standard ISO 178.

[0096] In one embodiment, PEBA is excluded from the definition of an impact modifier.

[0097] The polyolefins used as impact modifiers may be functionalized or unfunctionalized, or may be a mixture of at least one functionalized polyolefin and / or at least one unfunctionalized polyolefin. For simplicity, polyolefins are denoted as (B), functionalized polyolefins as (B1), and unfunctionalized polyolefins as (B2) below.

[0098] Unfunctionalized polyolefins (B2) are classically homopolymers or copolymers of alpha-olefins or diolefins, such as ethylene, propylene, 1-butene, 1-octene, and butadiene. Examples include: - Polyethylene, specifically LDPE, HDPE, LLDPE (linear low-density polyethylene), VLDPE (very low-density polyethylene), and metallocene polyethylene homopolymers and copolymers. - Propylene homopolymer or copolymer, - Ethylene / alpha-olefin copolymers, such as ethylene / propylene, EPR (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 in which the proportion of comonomers of ethylene and at least one product selected from salts or esters of unsaturated carboxylic acids, such as alkyl (meth)acrylates (e.g., methyl acrylate), or vinyl esters of saturated carboxylic acids, such as vinyl acetate (EVA), can reach 40% by weight.

[0099] Functionalized polyolefins (B1) can be polymers of alpha-olefins having reaction units (functional groups), such reaction units being acids, anhydrides, or epoxy functional groups. For example, the aforementioned polyolefins (B2) can be mentioned, which are grafted, copolymerized, or ternary polymerized by unsaturated epoxides, e.g., glycidyl (meth)acrylate, or by carboxylic acids or their corresponding salts or esters, e.g., (meth)acrylic acid (which can be completely or partially neutralized by metals, e.g., Zn), or even by carboxylic acid anhydrides, e.g., maleic anhydride. Functionalized polyolefins are, for example, PE / EPR mixtures, the ratio of which to weight can vary widely, e.g., from 40 / 60 to 90 / 10, and the mixtures are co-grafted with anhydrides, particularly maleic anhydride, according to graft rates of, for example, 0.01 to 5% by weight.

[0100] The functionalized polyolefin (B1) may be selected from the following (co)polymers grafted with maleic anhydride or glycidyl methacrylate, with grafting rates of, for example, 0.01 to 5% by weight: - Copolymers containing, for example, 35 to 80% by weight of ethylene, PE, PP, ethylene and propylene, butene, hexene or octene, - Ethylene / alpha-olefin copolymers, such as ethylene / propylene, EPR (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 and vinyl acetate copolymer (EVA) containing up to 40% by weight of vinyl acetate, - Ethylene and alkyl (meth)acrylate copolymers containing up to 40% by weight of alkyl (meth)acrylate, - Ethylene and vinyl acetate (EVA) and alkyl (meth)acrylate copolymers containing up to 40% by weight of comonomers.

[0101] Functionalized polyolefins (B1) can also be selected from ethylene / propylene copolymers (products described in EP-A-0,342,066) with monoamine polyamides (or polyamide oligomers) condensed with propylene, mainly grafted with maleic anhydride.

[0102] Functionalized polyolefin (B1) may also be a coat or terpolymer of at least the following units: (1) ethylene, (2) an alkyl (meth)acrylate or vinyl ester of a saturated carboxylic acid, and (3) an anhydride, such as maleic anhydride or (meth)acrylic acid, or an epoxy, such as glycidyl (meth)acrylate.

[0103] Examples of the latter type of functionalized polyolefin include the following copolymers, where ethylene is preferably equivalent to at least 60% by weight, and ter monomers (functional groups) are equivalent to, 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.

[0104] In the copolymers mentioned above, (meth)acrylic acid can be chlorided with Zn or Li.

[0105] The term “alkyl(meth)acrylate” in (B1) or (B2) refers to C1 to C8 alkyl methacrylates and acrylates, and may be selected from methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, 2-ethyl-hexyl acrylate, cyclohexyl acrylate, methyl methacrylate and ethyl methacrylate.

[0106] Furthermore, the previously cited polyolefin (B1) may also be crosslinked by any suitable method or agent (diepoxy, diacid, peroxide), and the term functionalized polyolefin also includes the previously cited polyolefin and a mixture of difunctional reagents that can react with them, such as diacids, dianhydrides, and diepoxys, or a mixture of at least two functionalized polyolefins that can react together.

[0107] The copolymers (B1) and (B2) mentioned above can be copolymerized by statistical or sequential methods and have linear or branched structures.

[0108] The molecular weight, MFI index, and density of these polyolefins may also vary widely, as those skilled in the art are aware. MFI, an abbreviation for melt flow index, is a measure of fluidity in the molten state. It is measured according to standard ASTM 1238.

[0109] Advantageously, the non-functionalized polyolefin (B2) is selected from polypropylene homopolymers or copolymers, any ethylene homopolymer or copolymer, and higher alpha-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 very low-density PE. It is known to those skilled in the art that these polyethylenes are produced by the "free radical" method, the "Ziegler" catalyst method, or more recently, by a "metallocene" catalyst.

[0110] Advantageously, the functionalized polyolefin (B1) is selected from any polymer comprising alpha-olefin units and units having polar reactive functional groups such as epoxy, carboxylic acid, or carboxylic acid anhydride functional groups. Examples of such polymers include terpolymers of ethylene, alkyl acrylate, and maleic anhydride or glycidyl methacrylate, such as Lotader® from the applicant, or polyolefins grafted with maleic anhydride, such as Orevac® from the applicant, as well as terpolymers of ethylene, alkyl acrylate, and (meth)acrylic acid. Homopolymers or copolymers of polypropylene grafted with carboxylic acid anhydrides and then condensed with polyamide or monoamine polyamide oligomers may also be mentioned.

[0111] Advantageously, the composition constituting the sealing layer(s) lacks polyether block amide (PEBA). In this embodiment, PEBA is therefore excluded from the impact resistance modifier.

[0112] Advantageously, the permeable composition lacks core-shell particles or core-shell polymers.

[0113] A core-shell particle should be understood as a particle in which the first layer forms the nucleus, and all subsequent layers form their respective shells.

[0114] Core-shell particles are obtained by a method having several steps, including at least two steps. Such methods are described, for example, in documents US2009 / 0149600 or EP0,722,961.

[0115] Regarding plasticizers The plasticizer may be one commonly used in polyamide-based compositions.

[0116] Advantageously, a plasticizer with good thermal stability is used so as not to form fumes during the steps of mixing different polymers and transforming the resulting composition.

[0117] In detail, this plasticizer is Benzenesulfonamide derivatives, such as n-butylbenzenesulfonamide (BBSA), ethyltoluenesulfonamide (ETSA), N-cyclohexyltoluenesulfonamide, and ortho and para isomers of N-(2-hydroxypropyl)benzenesulfonamide (HP-BSA), Hydroxybenzoate esters, for example, 2-ethylhexyl p-hydroxybenzoate (EHPB) and 2-decylhexyl p-hydroxybenzoate (HDPB), Esters or ethers of tetrahydrofurfuryl alcohol, for example, oligoethyleneoxytetrahydrofurfuryl alcohol, Esters of citric acid or hydroxymalonic acid, such as oligoethylene oxymalonate It can be selected from the following.

[0118] The preferred plasticizer is n-butylbenzenesulfonamide (BBSA).

[0119] Another, and more specifically, preferred, plasticizer is N-(2-hydroxypropyl)benzenesulfonamide (HP-BSA). In fact, the latter has the advantage of preventing the formation of deposits ("die smears") in the extrusion screw and / or die during the extrusion conversion step.

[0120] Of course, it is possible to use a mixture of plasticizers.

[0121] Regarding composite reinforcement layers and polymer P2j Polymer P2j may be a thermoplastic polymer or a thermosetting polymer.

[0122] One or more composite reinforcement layers may be present.

[0123] Each of the aforementioned layers consists of a fibrous material in the form of continuous fibers impregnated with a composition mainly comprising at least one thermoplastic polymer P2j, where j corresponds to the number of layers present.

[0124] j ranges from 1 to 10, more specifically from 1 to 5, and especially from 1 to 3, with j=1 being the preferred value.

[0125] The term "primarily" means that at least one of the polymers is present in an amount greater than 50% by weight of the total weight of the matrix of the composition and the composite.

[0126] Advantageously, the at least one dominant polymer is present in an amount of more than 60% by weight, particularly more than 70% by weight, more specifically more than 80% by weight, and more specifically 90% by weight or more, based on the total weight of the composition.

[0127] The composition may further comprise impact resistance modifiers and / or additives.

[0128] Apart from nucleating agents, additives may be selected from antioxidants, heat stabilizers, UV absorbers, light stabilizers, lubricants, inorganic fillers, flame retardants, plasticizers, and dyes.

[0129] Advantageously, the composition mainly consists of the thermoplastic polymer P2j, 0 to 15% by weight of an impact modifier, more specifically 0 to 12% by weight of an impact modifier, and 0 to 5% by weight of an additive, with the total amount of the constituent components of the composition equal to 100% by weight.

[0130] The at least one dominant polymer in each layer may be the same or different.

[0131] In one embodiment, a single dominant polymer is present in at least the composite reinforcement layer and does not adhere to the sealing layer.

[0132] In one embodiment, each reinforcing layer comprises the same type of polymer, more specifically, an epoxy resin or epoxy-based resin.

[0133] Polymer P2j Thermoplastic polymer P2j Thermoplastics, or thermoplastic polymers, generally refer to materials that are solid at ambient temperature. These can be semi-crystalline or amorphous, more specifically semi-crystalline, and they soften as the temperature rises, more specifically after passing the glass transition temperature (Tg). If amorphous, they flow at higher temperatures, or if semi-crystalline, they may exhibit a sharp transition when passing the so-called melting point (Tm). They become solid again when the temperature drops below the crystallization temperature Tc (for semi-crystalline materials) and below the glass transition temperature (for amorphous materials).

[0134] Tg, Tc, and Tm are determined by differential scanning calorimetry (DSC) in accordance with standards 11357-2:2013 and 11357-3:2013, respectively.

[0135] The number-average molecular weight (Mn) of the thermoplastic polymer is preferably in the range of 10,000 to 40,000, and more preferably in the range of 10,000 to 30,000. These Mn values ​​can correspond to an intrinsic viscosity of 0.8 or higher when determined in m-cresol according to standard ISO 307:2007, but by changing the solvent (using m-cresol instead of sulfuric acid at a temperature of 20°C).

[0136] Examples of suitable semi-crystalline thermoplastic polymers in the present invention include: Copolymers, such as polyamide-polyether copolymers, and more specifically polyamides, including aromatic and / or alicyclic structures, polyester, Polyaryl ether ketone (PAEK), Polyetheretherketone (PEEK), Polyetherketone (PEKK), Polyetherketone etherketone ketone (PEKEKK), Polyimide, more specifically polyetherimide (PEI) or polyamide-imide, Polyylsulfone (PSU), more specifically polyallylsulfone, for example, polyphenylsulfone (PPSU), Contains polyethersulfone (PES).

[0137] Semicrystalline polymers, specifically polyamides and their semicrystalline copolymers, are more preferably used.

[0138] The nomenclature is used to define polyamides as described in ISO standard 1874-1:2011 "Plastiques - Materiaux polyamides(PA) pour moulage et extrusion - Partie 1: Designation", particularly on page 3 (Tables 1 and 2), and is well known to those skilled in the art.

[0139] Polyamides may be homopolyamides, copolyamides, or mixtures thereof.

[0140] Advantageously, semicrystalline polyamides are semi-aromatic polyamides, particularly semi-aromatic polyamides of formula X / YAr as described in EP1505099, specifically semi-aromatic polyamides of formula A / XT (wherein A is a unit obtained from an amino acid, a unit obtained from a lactam, and the formula (Ca diamine)(Cb diacid), where a represents the number of carbon atoms in the diamine and b represents the number of carbon atoms in the diacid, and a and b are each selected from units between 4 and 36, preferably between 9 and 18), where the unit (Ca diamine) is selected from linear or branched aliphatic diamines, alicyclic diamines and alkyl aromatic diamines, and the unit (Cb diacid) is a unit selected from linear or branched aliphatic diacids, alicyclic diacids and aromatic diacids.

[0141] XT represents a unit obtained from the polycondensation of Cx diamine and terephthalic acid, where x represents the number of carbon atoms in the Cx diamine, and x is between 5 and 36, preferably between 9 and 18, and has formulas A / 5T, A / 6T, A / 9T, A / 10T or A / 11T, in particular, where A is a polyamide as defined above, and in detail polyamides include PA MPMDT / 6T, PA11 / 10T, PA 5T / 10T, PA 11 / BACT, PA 11 / 6T / 10T, PA MXDT / 10T, PA MPMDT / 10T, PA BACT / 10T, PA BACT / 6T, PA BACT / 10T / 6T, PA 11 / BACT / 6T, PA 11 / MPMDT / 6T, PA 11 / MPMDT / 10T, PA 11 / BACT / 10T, PA The chainring can be selected from either 11 / MXDT / 10T or 11 / 5T / 10T.

[0142] T corresponds to terephthalic acid, MXD corresponds to m-xylylenediamine, MPMD corresponds to methylpentamethylenediamine, and BAC corresponds to bis(aminomethyl)cyclohexane. The semi-aromatic polyamides defined above have a Tg of 80°C or higher.

[0143] Thermosetting polymer P2j The thermosetting polymer is selected from epoxy resins or epoxy-based resins, polyesters, vinyl esters, and polyurethanes, or mixtures thereof, more specifically from epoxy resins or epoxy-based resins.

[0144] Advantageously, each composite reinforcing layer consists of a composition comprising the same type of polymer, more specifically, an epoxy resin or epoxy-based resin.

[0145] The composition containing the polymer P2j is radiation-permeable, making it suitable for welding.

[0146] In another embodiment, the composite reinforcement layer is wrapped around the sealing layer without any subsequent welding.

[0147] Regarding the structure The multilayer structure thus includes a sealing layer and at least one composite reinforcing layer wrapped around the sealing layer, which may or may not be bonded to one another.

[0148] Advantageously, the sealing and reinforcing layers do not adhere to each other and consist of compositions containing different polymers, respectively.

[0149] However, the aforementioned different polymers may be of the same type.

[0150] Therefore, since the sealing layer consists of a composition containing aliphatic polyamide PA11, the reinforcing layer(s) consists of a composition containing a non-aliphatic polyamide, i.e., a semi-aromatic polyamide, such that it has a high Tg polymer as the matrix of the composite reinforcement.

[0151] The multilayer structure may include up to 10 composite reinforcing layers having different properties.

[0152] Advantageously, the multilayer structure includes one sealing layer and 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 composite reinforcing layers.

[0153] Advantageously, the multilayer structure includes one sealing layer and one, two, three, four, or five composite reinforcing layers.

[0154] Advantageously, the multilayer structure comprises one sealing layer and one, two, or three composite reinforcing layers.

[0155] Advantageously, these consist of compositions each containing a different polymer.

[0156] Advantageously, these consist of compositions comprising a polyamide equivalent to polyamide PA11 and an epoxide resin or epoxide-based resin P2j, respectively.

[0157] In one embodiment, the multilayer structure includes a single sealing layer and several reinforcing layers, wherein adjacent reinforcing layers are wound around the sealing layer, and other reinforcing layers are wound directly around adjacent reinforcing layers.

[0158] In one advantageous embodiment, the multilayer structure comprises a single sealing layer and a single composite reinforcing layer, the reinforcing layer being wound around the sealing layer.

[0159] All combinations of these two types of layers are therefore within the scope of the present invention, provided that at least the innermost composite reinforcing layer is wrapped around the sealing layer, and the other layers are either bonded to each other or not.

[0160] Advantageously, the polymer P2j is an epoxide resin or an epoxide-based resin.

[0161] Advantageously, in the multilayer structure, each reinforcing layer is composed of a polymer P2j of the same type, more specifically an epoxy resin or epoxy-based resin.

[0162] Advantageously, the polyamide P2j is identical in all reinforcing layers.

[0163] In one embodiment, in the multilayer structure, the sealing layer is made of a composition containing polyamide PA11, and each reinforcing layer is made of a composition containing the same type of polymer P2j, specifically an epoxide resin or epoxide-based resin.

[0164] In one embodiment, in the multilayer structure, the sealing layer is made of a composition containing polyamide PA11, and each reinforcing layer is made of a composition containing polymer P2j of the same type, wherein polymer P2j is specifically a semi-aromatic polyamide selected from PA MPMDT / 6T, PA PA11 / 10T, PA 11 / BACT, PA 5T / 10T, PA 11 / 6T / 10T, PA MXDT / 10T, PA MPMDT / 10T, PA BACT / 10T, PA BACT / 6T, PA BACT / 10T / 6T, PA 11 / BACT / 6T, PA 11 / MPMDT / 6T, PA 11 / MPMDT / 10T, PA 11 / BACT / 10T, and PA 11 / MXDT / 10T.

[0165] In one embodiment, the multilayer structure consists of a single sealing layer and a single reinforcing layer, and the polymer P2j is specifically a semi-aromatic polyamide selected from PA MPMDT / 6T, PA 11 / 10T, PA 11 / BACT, PA 5T / 10T, PA 11 / 6T / 10T, PA MXDT / 10T, PA MPMDT / 10T, PA BACT / 10T, PA BACT / 6T, PA BACT / 10T / 6T, PA 11 / BACT / 6T, PA 11 / MPMDT / 6T, PA 11 / MPMDT / 10T, PA 11 / BACT / 10T, and PA 11 / MXDT / 10T.

[0166] In another embodiment, the multilayer structure comprises a single sealing layer and a single reinforcing layer in which the polymer P2j is an epoxide resin or an epoxide-based resin.

[0167] Advantageously, the multilayer structure further comprises at least one outer layer made of a fibrous material consisting of continuous glass fibers impregnated with a permeable amorphous polymer, the outermost layer of the multilayer structure.

[0168] The aforementioned outer layer is a second reinforcing layer, but it is permeable, which allows text to be placed on the structure.

[0169] Under certain circumstances, the aforementioned outer layer does not correspond to a layer located on the outermost composite reinforcement layer made of polyamide polymer, and lacks the structure described above.

[0170] Regarding fibrous materials The fibers that make up the aforementioned fibrous material are, in detail, inorganic, organic, or plant fibers.

[0171] Advantageously, the fibrous material may or may not be sized.

[0172] The fibrous material may therefore contain up to 3.5% by weight of an organic material (of the thermosetting or thermoplastic resin type), which is called sizing.

[0173] Inorganic fibers include, for example, carbon fibers, glass fibers, basalt or basalt-based fibers, silica fibers, or silicon carbide fibers. Organic fibers include thermoplastic or thermosetting polymer-based fibers, such as semi-aromatic polyamide fibers, aramid fibers, or polyolefin fibers. Preferably, these are amorphous thermoplastic polymer-based, and if the thermoplastic polymer mixture is amorphous, they have a Tg higher than the glass transition temperature Tg of the polymer or thermoplastic polymer mixture constituting the pre-impregnation matrix, or if the thermoplastic polymer mixture is semi-crystalline, they have a Tg higher than the Tm of the polymer or thermoplastic polymer mixture constituting the pre-impregnation matrix. Advantageously, these are semi-crystalline thermoplastic polymer-based, and if the thermoplastic polymer mixture is amorphous, they have a melting temperature Tm higher than the Tg of the polymer or thermoplastic polymer mixture constituting the pre-impregnation matrix, or if the thermoplastic polymer mixture is semi-crystalline, they have a melting temperature Tm higher than the Tm of the polymer or thermoplastic polymer mixture constituting the pre-impregnation matrix. Therefore, there is no risk of melting during impregnation by the thermoplastic matrix of the final composite in the organic fibers constituting the fibrous material. Plant fibers include natural linen, hemp, lignin, bamboo, silk, spider silk in particular, sisal hemp, and other cellulose fibers, in particular viscose. These plant fibers may be used alone, treated with a coating layer, or coated to promote adhesion and impregnation of a thermoplastic polymer matrix.

[0174] Textile materials can be cloth, string, or woven fabrics made from fibers.

[0175] This could be considered equivalent to a fiber that uses a supporting thread.

[0176] These component fibers can be used individually or in mixtures. Therefore, organic fibers can be mixed with inorganic fibers to pre-impregnate them with thermoplastic polymer powder, forming a pre-impregnated fibrous material.

[0177] Organic fiber yarns can have several basis weights. These can further have several shapes. The component fibers of a fibrous material can also take the form of a mixture of these reinforcing fibers having different shapes. The fibers are continuous fibers.

[0178] Preferably, the fibrous material is selected from glass fibers, carbon fibers, basalt fibers or basalt-based fibers, or mixtures thereof, and more specifically from carbon fibers.

[0179] This is used in the form of one roving or several rovings.

[0180] In another aspect, the present invention relates to a method for producing the above-defined multilayer structure, characterized by comprising the step of preparing a sealing layer by extrusion blow molding, rotational molding, injection molding and / or extrusion.

[0181] In one embodiment, the method for generating a multilayer structure includes the step of filament winding a reinforcing layer defined above around a sealing layer defined above.

[0182] All the characteristics detailed above also apply to methods. [Examples]

[0183] In all examples, the reservoir is obtained by rotational molding of the sealing layer (liner) at a temperature suitable for the properties of the thermoplastic resin used.

[0184] In the case of composite reinforcements made of epoxide or epoxide-based resins, a wet filament winding method is used, which involves winding fibers around a liner, which have been previously pre-impregnated in a liquid epoxide bath or epoxide-based liquid bath. The reservoir is then polymerized in an oven for 2 hours.

[0185] In all other cases, a fibrous material previously impregnated with thermoplastic resin (tape) is used. This tape is deposited by filament winding using a 1500W laser heater robot at a speed of 12 m / min, without a polymerization step.

[0186] Example 1 Notched Charpy impact test at -40°C according to ISO 179-1:2010. Two types of long-chain liners made of PA11 and PA12, and two types of short-chain liners, were prepared by rotational molding as shown above.

[0187] These four types of liners were tested using a notched Charpy impact test at -40°C, and the results are shown in Figure 1.

[0188] The cold resistance of the PA11 liner is considerably higher than that of the long-chain PA12 liner, as well as the short-chain PA6 and PA66 liners.

[0189] Example 2 Permeability of PA11 and PA12 liners (Arkema) and HDPE liners (Marlex®, HMN TR-942 (Chevron Phillips)) Two types of long-chain liners, the first PA11 (Arkema) and the second PA12 (Arkema), as well as an HDPE liner, were prepared by rotational molding, and their hydrogen permeability was tested at 23°C.

[0190] This involves flashing the top surface of the film with a test gas (hydrogen) and measuring the flow diffusing through the lower part of the film by gas chromatography, with the vector gas being nitrogen.

[0191] The experimental conditions are presented in Table 1. [Table 1] TIFF2023511975000002.tif76170

[0192] The results are shown in Figure 2, demonstrating that the PA11 liner has significantly lower permeability than the long-chain liners and HDPE liners made of PA12.

[0193] Example 3 Effect of plasticizer (N-butylbenzenesulfonamide: BBSA) ratio on notched Charpy impact test at -40°C according to ISO 179-1:2010. Two types of PA11 and PA12 liners were prepared by rotational molding: one without plasticizers, and the other containing 7% or 12% plasticizer (BBSA) relative to the total weight of the composition.

[0194] These four types of liners were tested using a notched Charpy impact test at -40°C according to ISO 179-1:2010, and the results are shown in Figure 3.

[0195] In fact, plasticizers have a significant detrimental effect on PA12 when it is colder than on PA11, as this weakens the structure of PA12 and increases its permeability, specifically from 50% at 7% BBSA.

[0196] Example 4 The effect of the ratio of impact resistance modifiers (composed of "LT cocktail" having the following composition: lotader® 4700 (50%) + lotader® AX8900 (25%) + Lucalen® 3110 (25%)) on the hydrogen permeability of PA11 liners.

[0197] The hydrogen permeability of PA11 liners without plasticizers and with and without impact modifiers was tested, and the results are reported in Table 2. [Table 2] TIFF2023511975000003.tif31170

[0198] Penetration is (cc.25μ / m 2 It can also be expressed as 0.24hPa.

[0199] The permeability must then be 101,325 times greater.

[0200] The results indicate that the ratio of impact-resistant modifiers affects hydrogen permeability.

[0201] The higher the proportion of impact-resistant additive, the greater the penetration.

[0202] Example 5 A Type IV hydrogen storage tank consisting of a T700SC31E (Toray) carbon fiber epoxide composite reinforcement layer (Tg 120°C) and a PA11 sealing layer.

[0203] The operating temperature is sufficient for rapid tank filling, specifically within 3 to 5 minutes.

[0204] Example 6 (counterexample) A Type IV hydrogen storage tank consisting of a T700SC31E (Toray) carbon fiber epoxide composite reinforcement layer (Tg 120°C) and an HDPE sealing layer.

[0205] The operating temperature is too low for rapid tank filling, specifically within 3 to 5 minutes.

[0206] Example 7 A Type IV hydrogen storage tank consisting of a T700SC31E (Toray) carbon fiber BACT / 10T composite reinforcement layer and a PA11 sealing layer.

[0207] The selected BACT / 10T composition has a melting temperature Tm of 283°C, a crystallization temperature Tc of 250°C, and a glass transition temperature of 164°C.

[0208] Tg, Tc, and Tm are determined by differential scanning calorimetry (DSC) in accordance with standards 11357-2:2013 and 11357-3:2013, respectively.

[0209] The PA BACT / 10T-based composite does not have long crosslinks, but it has a high Tg matrix of the 8h type at 140°C.

[0210] As a result, the tank is completed after the fibers are deposited, saving 8 hours of process time.

Claims

1. 1. A multi-layer structure for transporting, distributing or storing hydrogen, comprising: It comprises, from the inside to the outside, at least one sealing layer (1) and at least one composite reinforcing layer (2), The innermost composite reinforcing layer is wrapped around the sealing layer (1), The sealing layer is mainly thermoplastic polyamide polymer PA11, up to 15 wt.% of an impact modifier, based on the total weight of the composition; a composition comprising up to 1.5 wt. % of a plasticizer, based on the total weight of the composition; the composition is devoid of a nucleating agent and a polyether block amide (PEBA); at least one of said composite reinforcing layers consists of a fibrous material in the form of continuous fibers impregnated with a composition comprising mainly at least one polymer P2j, which is an epoxy resin or an epoxy-based resin, j=1 to m, m being the number of reinforcing layers; the multilayer structure lacks an outermost layer made of polyamide polymer adjacent to an outermost composite reinforcing layer; The multilayer structure is a tank. Multilayer structure.

2. The multi-layer structure of claim 1 , wherein each reinforcing layer comprises the same polymer.

3. 10. The multi-layer structure of claim 1, characterized in that it has a single reinforcing layer.

4. 4. The multilayer structure according to claim 3, characterized in that the multilayer structure consists of a single reinforcing layer and the polymer P2j is an epoxy resin or an epoxy-based resin.

5. 5. A multilayer structure according to any one of claims 1 to 4, characterized in that the fibrous material of the composite reinforcing layer is selected from glass fibres, carbon fibres, basalt fibres or basalt-based fibres, or mixtures thereof.

6. 6. The multilayer structure of claim 1, further comprising at least one outer layer of fibrous material made of continuous glass fibers impregnated with a transparent amorphous polymer, said layer being the outermost layer of the multilayer structure.

7. 7. A method for manufacturing a multilayer structure according to any one of claims 1 to 6, characterized in that it comprises the step of preparing the sealing layer by extrusion blow molding, rotational molding, injection molding and / or extrusion.

8. 8. A method for manufacturing a multi-layer structure according to claim 7, comprising the step of filament winding a reinforcing layer according to claim 1 around a sealing layer according to claim 1.

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