Multilayer structures and articles for gas storage and transport

Abstract

A multilayer structure suitable for the manufacture of articles for gas storage and transport, particularly pressure vessels. The vessels are especially suitable for the storage and transport of compressed gases in vehicles.

Description

[Technical Field]

[0001] Cross-reference of related applications This application claims priority under U.S. Provisional Patent Application No. 63 / 387314 filed December 14, 2022, and European Patent Application Publication No. 23158670.2 filed February 27, 2023, the entire contents of each of these applications being incorporated herein by reference for any purpose.

[0002] The present invention relates to a multilayer structure suitable for the manufacture of articles suitable for the storage and transport of gases, particularly gases in pressure vessels. The present invention further relates to articles such as pressure vessels containing this multilayer structure. The present invention further relates to a method for manufacturing a pressure vessel. [Background technology]

[0003] Pressure vessels characterized by high gas barrier properties have been used for long-term storage of various gases such as oxygen, carbon dioxide, nitrogen, argon, LPG (liquefied petroleum gas), methane, and hydrogen. Pressure vessels are known that include an unstructured inner layer or liner surrounded by a structural fiber-reinforced composite material for containing fluids or gases under pressure. The liner acts as a barrier between the fluid or gas and the fiber-reinforced composite material, thus preventing leakage and / or other degradation of the fiber-reinforced composite material structure. The use of structural fiber-reinforced composite materials containing a thermoplastic polymer matrix is ​​advantageous in facilitating the recycling of pressure vessels. Pressure vessels including a polyamide liner and an outer layer which is a composite material containing continuous fibers and polyamide resin impregnated into the continuous fibers are disclosed, for example, in European Patent Application Publication No. 3225888A1, European Patent Application Publication No. 3390016A1, and International Publication No. 21152254A1.

[0004] However, there remains a need for the development of articles for the transport and storage of hydrogen and gases in general, particularly pressure vessels, that possess high performance qualities in terms of impermeability to storage gases, mechanical properties at both low and high temperatures, and high thermal decomposition temperatures, in order to facilitate processing. An additional advantage for use is the non-flammability of pressure vessels.

[0005] Therefore, an object of the present invention is to provide articles such as pressure vessels that have very low permeability to gases such as hydrogen and excellent mechanical strength over a wide temperature range without requiring the use of structural layers made from metal or other non-thermoplastic polymer materials. This object is achieved by the multilayer structure of the present invention. [Overview of the project]

[0006] Therefore, the first object of the present invention is a multilayer structure comprising at least one barrier layer [layer (BL)] and at least one composite material layer [layer (CL)] in contact with the at least one barrier layer, • The layer (BL) contains poly(arylene sulfide) polymer, • The layer (CL) contains continuous reinforcing fibers and poly(arylene sulfide) polymer. It is a multilayer structure.

[0007] A second object of the present invention is an article for storing or transporting gas, comprising the multilayer structure of the first object. Layer (BL) constitutes the inner layer of the article that comes into contact with the gas being stored or transported (hereinafter also referred to as the "inner layer" or "liner"), while layer (CL) constitutes the outer layer of the article. The article may be a container, preferably a pressure vessel, i.e., a container for storing gas under pressure.

[0008] A third object of the present invention is a compressed gas in a container containing the multilayer structure of the first object, wherein the compressed gas is in contact with the layer (BL). Further objects of the present invention are a method for manufacturing the container and the use of the container in a vehicle. [Modes for carrying out the invention]

[0009] In this application: - Any description, even if it is described in relation to a particular embodiment, is applicable to and interchangeable with other embodiments of the present disclosure. - Where it is said that an element or component is included in and / or selected from a list of enumerated elements or components, in the relevant embodiments expressly considered herein, the element or component may also be any one of the individual enumerated elements or components, or may be selected from any group of two or more of the expressly enumerated elements or components; it should be understood that any element or component enumerated in a list of elements or components may be omitted from such list; - Any enumeration of numerical ranges by endpoints in this specification includes all numbers contained within the enumerated range, as well as the endpoints and equivalents of the range; - In expressions such as "a poly(arylene sulfide) polymer," the indefinite article "a" is intended to mean "one or more" or "at least one" unless otherwise specified; - The use of parentheses "( )" before and after the names, symbols, or numbers of compounds, such as "layer (BL)" and "layer (CL)," is solely for the purpose of better distinguishing those names, symbols, or numbers from the rest of the text; therefore, such parentheses may be omitted.

[0010] A first object of the present invention is a multilayer structure comprising at least one barrier layer [layer (BL)] and at least one composite material layer [layer (CL)] in contact with the at least one barrier layer, • The layer (BL) contains poly(arylene sulfide) polymer, • The layer (CL) contains continuous reinforcing fibers and poly(arylene sulfide) polymer. It is a multilayer structure.

[0011] Poly(arylene sulfide) polymer Layer (BL) and layer (CL) contain a poly(arylene sulfide) polymer. The poly(arylene sulfide) polymer in layer (BL) may be the same as or different from the poly(arylene sulfide) polymer used in layer (CL).

[0012] If there are two or more layers (BL), each layer (BL) may contain the same or different poly(arylene sulfide) polymers, preferably the same poly(arylene sulfide) polymer.

[0013] If there are two or more layers (CL), each layer (CL) may contain the same or different poly(arylene sulfide) polymers, typically the same poly(arylene sulfide) polymer.

[0014] The poly(arylene sulfide) polymer typically contains at least 50.0 mol% of repeating units (R PAS ) having at least one aromatic ring bonded to a sulfur atom. In some embodiments, the amount of repeating units (R PAS ) is at least 60.0 mol%, at least 70.0 mol%, at least 80.0 mol%, at least 90.0 mol%, at least 95.0 mol%, at least 97.0 mol%, at least 98.0 mol%, at least 99.0 mol% or at least 99.9 mol%. As used herein, mol% is, unless otherwise specified, relative to the total number of repeating units in the poly(arylene sulfide) polymer.

[0015] The repeating unit (R PAS ) has the following group of formulas:

Chemical formula

[0016] For the sake of clarity, it is stated that when i or j is zero, the corresponding aromatic ring is unsubstituted.

[0017] Unless specifically stated otherwise, the terms "alkyl" and derivative terms such as "alkoxy" and "alkylaryl" as used herein include straight-chain, branched-chain, and cyclic moieties within their scope. Examples of alkyl groups are methyl, ethyl, 1-methylethyl, propyl, 1,1-dimethylethyl, and cyclopropyl. Unless specifically described otherwise, each alkyl and aryl group may be unsubstituted or substituted with one or more substituents selected from, but not limited to, halogen, hydroxy, sulfo, C1-C6 alkoxy, C1-C6 alkylthio, C1-C6 acyl, formyl, cyano, C6-C15 aryloxy or C6-C15 aryl, provided that the substituents are sterically compatible and the rules of chemical bonding and strain energy are satisfied. The term "halogen" or "halo" includes fluorine, chlorine, bromine, and iodine, with fluorine being preferred.

[0018] The term "aryl" refers to a phenyl, indanyl, or naphthyl group. An aryl group may contain one or more alkyl groups, in which case it may be called an "alkylaryl," and may consist, for example, of a cycloaromatic group and two C1-C6 groups (e.g., methyl or ethyl). An aryl group may also contain one or more heteroatoms, for example, N, O, or S, and may be called a "heteroaryl" group; these heteroaromatic rings may be condensed with other aromatic systems. Such heteroaromatic rings include, but are not limited to, furanyl, thienyl, pyrrolyl, pyrazolyl, imidazolyl, triazolyl, isoxazolyl, oxazolyl, thiazolyl, isothiazolyl, pyridyl, pyridazyl, pyrimidyl, pyrazinyl, and triazinyl ring structures. The aryl or heteroaryl substituent may be unsubstituted, or it may be substituted with one or more substituents selected from, but not limited to, halogens, hydroxyls, C1-C6 alkoxys, sulfosulfos, C1-C6 alkylthios, C1-C6 acyls, formyls, cyanos, C6-C15 aryloxys, or C6-C15 aryls, provided that the substituents are sterically compatible and the rules for chemical bonding and strain energy are satisfied.

[0019] The poly(arylene sulfide) polymer may be amorphous or semi-crystalline. As used herein, the amorphous polymer has a melting enthalpy of 5 J / g or less. Those skilled in the art will recognize that if the poly(arylene sulfide) polymer is amorphous, it does not have a detectable melting point. Therefore, those skilled in the art will recognize that if the poly(arylene sulfide) polymer has a melting point, it refers to a semi-crystalline polymer. Preferably, the poly(arylene sulfide) polymer is semi-crystalline. In some embodiments, the poly(arylene sulfide) polymer has a melting enthalpy of at least 10 J / g, at least 20 J / g, or at least 25 J / g. In some embodiments, the poly(arylene sulfide) polymer has a melting enthalpy of 90 J / g or less, 70 J / g or less, or 60 J / g or less. In some embodiments, the poly(arylene sulfide) polymer has a melting enthalpy of 10 J / g to 90 J / g or 20 J / g to 70 J / g. The melting enthalpy can be measured using differential scanning calorimetry (DSC) with heating and cooling rates of 20°C / min according to ASTM D3418. Advantageously, three scans are used in each DSC test: a first heating to 350°C, followed by a first cooling to 30°C, followed by a second heating to 350°C.

[0020] Preferably, the poly(arylene sulfide) polymer has a melt flow rate of up to 700 g / 10 min, more preferably up to 500 g / 10 min. Preferably, the poly(arylene sulfide) has a melt flow rate of at least 1 g / 10 min, more preferably at least 5 g / 10 min. In this specification, the melt flow rate of any poly(arylene sulfide) polymer refers to the value measured at 5 kg and 315.6 °C as detailed in the experimental section.

[0021] As described above, each layer of the multilayer structure contains a poly(arylene sulfide) polymer.

[0022] According to an embodiment of the present invention, the poly(arylene sulfide) polymer is poly(phenylene sulfide) (hereinafter referred to as "PPS" in this specification). The expression "poly(phenylene sulfide)" or PPS is used to refer to a poly(arylene sulfide) polymer in which the repeating unit (R PAS ) is represented by formula (1). More preferably, the repeating unit (R PAS ) is formula (4):

Chemical formula

[0023] In PPS, most preferably, the repeating unit (R PAS ) is represented by formula (4) with i = 0

[0024] PPS may or may not be pickled. In some embodiments, PPS is pickled with acetic acid

[0025] In a preferred embodiment, at least 90.0 mol% of the repeating units of the PPS polymer are the repeating units of formula (4) with i = 0. The PPS polymer may consist essentially of the repeating units of formula (4) with i = 0

[0026] A suitable PPS is commercially available under the trade name Ryton® PPS from Solvay Specialty Polymers USA, LLC

[0027] The melt flow rate (5 kg, 315.6 °C) of PPS can be 1 to 400 g / 10 min, such as 5 to 300 g / 10 min or 5 to 200 g / 10 min

[0028] Layer (BL) Layer (BL) is designed to provide a barrier against gas permeation

[0029] Layer (BL) does not contain any continuous reinforcing fibers

[0030] The layer (BL) has a thickness that provides the required value of gas permeability for the application. The layer (BL) is typically at least 100 microns thick, and generally at least 250 microns thick. The layer (BL) can have a maximum thickness of 10.0 mm, and even as low as 8.5 mm or 7.5 mm. The layer (BL) can have a thickness of 100 microns to 10.0 mm, generally 250 microns to 10.0 mm, even 300 microns to 8.5 mm, and even 500 microns to 6.0 mm.

[0031] In the first embodiment, the poly(arylene sulfide) polymer is the sole polymer in layer (BL). In such embodiments, layer (BL) contains 75.0% by weight or more, more preferably 80.0% by weight or more, and more preferably 85.0% by weight or more of poly(arylene sulfide) based on the total weight of layer (BL). In such embodiments, layer (BL) may contain one or more additives commonly used in poly(arylene sulfide) polymer formulations in amounts of 25.0% by weight or less. Non-limiting examples of suitable additives include antioxidants (e.g., UV stabilizers and heat stabilizers), processing aids, nucleating agents, lubricants, flame retardants, fume retardants, antistatic agents, antiblocking agents, colorants, and pigments.

[0032] The total amount of additives may be 20.0% by weight or less, and more precisely 10.0% by weight or less, relative to the total weight of the layer (BL). If present, the amount of one or more additives shall be at least 1.0% by weight or more precisely 2.0% by weight, relative to the total weight of the poly(aryl sulfide) polymer.

[0033] In a preferred embodiment of the above-described model, the poly(arylene sulfide) polymer is PPS.

[0034] PPS suitable for layer (BL) advantageously has a melt flow rate of 5-200 g / 10 min, for example, 5-180 g / 10 min (5 kg, 315.6 °C). In some cases, the melt flow rate may be 5-50 g / 10 min, or even 5-40 g / 10 min.

[0035] In the second embodiment, the layer (BL) comprises a poly(arylene sulfide) polymer, preferably PPS, and at least one other thermoplastic polymer.

[0036] In an advantageous embodiment of the above-described model, the layer (BL) comprises a poly(arylene sulfide) polymer, preferably PPS, and an impact modifier.

[0037] Suitable impact modifiers include, for example, functionalized polyolefins having a glass transition temperature of less than 25°C.

[0038] The polymer backbone of the impact modifier can be selected from an elastomer backbone comprising polyethylene and its copolymers, such as ethylene-butene; ethylene-octene; polypropylene and its copolymers; polybutene; polyisoprene; ethylene-propylene-rubber (EPR); ethylene-propylene-diene monomer rubber (EPDM); ethylene-acrylate rubber; butadiene-acrylonitrile rubber, ethylene-acrylic acid (EAA), ethylene-vinyl acetate (EVA); acrylonitrile-butadiene-styrene rubber (ABS), block copolymer styrene-ethylene butadiene styrene (SEBS); block copolymer styrene-butadiene styrene (SBS); methacrylate-butadiene styrene (MBS) type core-shell elastomer, or a mixture of one or more of the above.

[0039] When the impact modifier is functionalized, the functionalization of the backbone can be achieved by copolymerization of monomers including the functionalization or by grafting the polymer backbone with further components.

[0040] Specific examples of functionalized impact modifiers include, among others, terpolymers of ethylene with acrylic ester and glycidyl methacrylate; copolymers of ethylene with butyl acrylate; copolymers of ethylene with butyl acrylate and glycidyl methacrylate; ethylene-maleic anhydride copolymer; EPR grafted with maleic anhydride; styrene copolymer grafted with maleic anhydride; SEBS copolymer grafted with maleic anhydride; styrene-acrylonitrile copolymer grafted with maleic anhydride; and ABS copolymer grafted with maleic anhydride.

[0041] Functionalized polyolefin impact modifiers are available from commercial sources and include maleic anhydride-functionalized ethylene-propylene copolymer rubbers containing approximately 0.6 wt percent pendant succinic anhydride groups, such as maleic anhydride-functionalized ethylene-propylene copolymer rubbers containing approximately 0.6 wt percent pendant succinic anhydride groups, such as Exxelor® VA 1801 from ExxonMobil Chemical Company; acrylate-modified polyethylenes available as Surlyn®, such as Surlyn® 9920, which are acrylic acid or methacrylic acid-modified polyethylenes from Dow Inc.; maleic anhydride-modified SEBS block copolymers, such as Kraton® FG1901X, which are SEBS grafted with approximately 2 wt percent maleic anhydride, available from Kraton Polymers; and maleic anhydride-functionalized EPDM terpolymer rubbers, such as Royaltuf® 498, which are 1% maleic anhydride-functionalized EPDM, available from SI Group.

[0042] Other desirable functionalization impact modifiers include, but are not limited to, ethylene-higher alpha-olefin polymers and ethylene-higher alpha-olefin-diene polymers grafted or copolymerized with reactive carboxylic acids or derivatives thereof, such as acrylic acid, methacrylic acid, maleic anhydride, or esters thereof. Suitable higher alpha-olefins include, but are not limited to, C3-C8 alpha-olefins such as propylene, 1-butene, 1-hexene, and styrene.

[0043] Among reactive impact modifiers, a random terpolymer of ethylene, acrylic acid ester, and glycidyl methacrylate can be cited, which is commercially available from Arkema (Bristol, PA, USA) under the trade name Lotader® AX8900. Another example of the aforementioned reactive impact modifier is the trade name Paraloid. TM Commercially available from Dow Inc. (Midland, MI, USA) under the EXL 2314 designation, it is a core-shell type acrylate-based impact modifier having a core primarily composed of cross-linked poly(n-butyl acrylate) rubber and a shell phase primarily composed of poly(methyl methacrylate)-poly(glycidyl methacrylate) copolymer.

[0044] In the second embodiment described above, the layer (BL) comprises at least one thermoplastic polymer and / or impact modifier in an amount of 1.0% to 25.0% by weight relative to the total weight of the layer (BL). The impact modifier may be at least 2.0% by weight, at least 3.0% by weight, and even more likely at least 5.0% by weight of the total weight of the layer (BL). The impact modifier is typically 20.0% by weight or less, 15.0% by weight or less, 12.0% by weight or less, and even more likely at least 10.0% by weight or less. A preferred range may be, for example, 1.0 to 15.0% by weight, even more likely at 1.0 to 12.0% by weight, or even more likely at 2.0 to 10.0% by weight.

[0045] In a second embodiment, the layer (BL) may further contain additives as detailed above. The total amount of additives may be 20.0% by weight or less, more preferably 10.0% by weight or less, and / or at least 1.0% by weight or more preferably 2.0% by weight, relative to the total weight of the layer (BL).

[0046] The layer (BL) can be manufactured using general techniques for the manufacture of poly(phenylene sulfide) polymer films or sheets, as is known to those skilled in the art. For example, the layer (BL) can be manufactured by rotational molding, injection molding, and optional welding, tubular extrusion, and extrusion blow molding.

[0047] The poly(phenylene sulfide) polymer film may be optionally uniaxially or biaxially stretched. Biaxial stretching can be performed using a tenter-frame biaxial stretching apparatus known in the art.

[0048] Layer (CL) The multilayer structure of the present invention comprises at least one layer (CL). The layer (CL) comprises continuous reinforcing fibers and a poly(arylene sulfide) polymer.

[0049] The poly(arylene sulfide) polymer is as defined above. This may be the same as or different from the poly(arylene sulfide) polymer used in layer (BL). In a preferred embodiment, the poly(arylene sulfide) polymer in layer (CL) is PPS.

[0050] PPS suitable for layer (CL) advantageously has a melt flow rate of 10-200 g / 10 min, for example, 30-150 g / 10 min (5 kg, 315.6 °C).

[0051] In a favorable embodiment, the poly(arylene sulfide) polymer is the only polymer in the layer (CL).

[0052] The layer (CL) comprises continuous reinforcing fibers impregnated with a poly(arylene sulfide) polymer, which is described in detail below. As used herein, the term "continuous reinforcing fibers" refers to fibers having a length of at least 5 mm. The fiber length corresponds to the longest dimension of the fiber.

[0053] In some embodiments, the continuous reinforcing fibers have a length of at least 1 cm, at least 25 cm, or at least 50 cm in their longest dimension. The length of the continuous reinforcing fibers depends on the shape and size of the finished part.

[0054] The continuous reinforcing fibers are selected from the group consisting of glass fibers, carbon fibers, aluminum fibers, metal fibers, ceramic fibers, titanium fibers, magnesium fibers, boron carbide fibers, rock wool fibers, steel fibers, aramid fibers, and natural fibers (e.g., cotton, linen, and wood). Preferably, the continuous reinforcing fibers are selected from the group consisting of glass fibers, carbon fibers, aramid fibers, and ceramic fibers. Advantageously, the continuous reinforcing fibers are carbon fibers.

[0055] In some embodiments, the layers (CL) may include one or more additional continuous reinforcing fibers, each with a different composition, as described above.

[0056] Overall, continuous reinforcing fibers constitute at least 5.0% of the total volume of the layer (CL). Typically, continuous reinforcing fibers constitute at least 10.0%, more preferably at least 15.0%, more preferably at least 20.0%, more preferably at least 25.0%, and more preferably at least 30.0% of the total volume of the layer (CL). Continuous reinforcing fibers constitute 80.0% or less, 75.0% or less, and more preferably at least 70.0% of the total volume of the layer (CL). Conveniently, continuous reinforcing fibers may represent 20.0% to 75.0%, 25.0% to 70.0%, 25.0% to 65.0%, and even 30.0% to 60.0% of the total volume of the layer (CL). The polymer matrix constitutes the remainder of the volume of the layer (CL).

[0057] The continuous reinforcing fibers in the layer (CL) are generally aligned along a single direction. Generally, the aligned fibers are oriented such that at least 70%, at least 80%, at least 90%, or at least 95% of the fibers have a direction within 30 degrees, 25 degrees, 20 degrees, 15 degrees, or 10 degrees along the direction of the other fibers.

[0058] In certain embodiments, continuous reinforcing fibers in a layer (CL) may be arranged at an angle to other elements. The continuous reinforcing fibers may be arranged as a woven fabric, a layered fabric, or any combination of one or more of these.

[0059] The layer (CL) can be manufactured by methods well known in the art. Typically, the manufacturing method includes impregnating a (arylene sulfide) polymer composition with continuous reinforcing fibers, and then cooling or drying it to form the layer (CL).

[0060] Impregnating a poly(arylene sulfide) polymer composition with continuous reinforcing fibers can be done, for example, by a melt impregnation process that includes contacting the continuous reinforcing fibers with a molten polymer material. After melt impregnation, the impregnated continuous reinforcing fibers are cooled to form a solid composite material.

[0061] Impregnation can be carried out by a solution process or a slurry process. In the solution process, a solution is formed by dissolving the polymer in a liquid medium. For example, the solution coats the surface of the continuous reinforcing fibers by passing the fibers through a solution bath. The coated fibers are then heated and consolidated. In the slurry process, the continuous fibers are impregnated with polymer particles, for example, by passing the fibers through a suspension of particles or a fluidized bed of particles. The fibers containing the polymer particles are then heated and consolidated.

[0062] The layers (CL) typically have a thickness of 100 to 500 microns. The thickness is adjusted to obtain a multilayer structure that can be easily molded to provide articles such as containers.

[0063] multilayer structure The multilayer structure of the present invention includes at least one layer (BL) and at least one layer (CL) in contact with the at least one barrier layer defined above. There may be two or more layers (BL) in the multilayer structure. There may be two or more layers (CL) in the multilayer structure.

[0064] A multilayer structure may include up to 10 layers (BL) and up to 10 or more layers (CL).

[0065] A multilayer structure does not include a binder or adhesive layer between layers (BL) and layers (CL).

[0066] A multilayer structure can contain more layers (BL) than layers (CL), and vice versa. Typically, a multilayer structure does not contain alternating layers (BL) and layers (CL).

[0067] A multilayer structure may consist of one or more layers (BL) and one or more layers (CL).

[0068] Advantageously, a multilayer structure includes 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 layers (BL) and 1, 2, 3, 4, 5, 10, 50, 100, or even more layers such as 200 or 300 (CL).

[0069] In one embodiment, the multilayer structure includes a single layer (BL) and multiple layers (CL). The multilayer structure may consist of a single layer (BL) and one or more layers (CL), where the layer (BL) constitutes one of the outer surfaces of the multilayer structure.

[0070] In some embodiments, the multilayer structure may include an additional layer in contact with the layer (CL) opposite to the layer (BL). The additional layer may or may not contain reinforcing fibers. The additional layer may or may not contain a poly(arylene sulfide) polymer. Preferably, the additional layer is not made of metal strip material.

[0071] Goods A further object of the present invention is an article for the storage and / or transport of gases, comprising the multilayer structure defined above. Notable non-limiting examples of the article are hoses, pipes, tubes, joints, tanks, reservoirs, or typically containers.

[0072] Among these, the multilayer structure of the present invention is particularly suitable for use as a hose for compressed gas, especially hydrogen, because it excels in both flexibility and thermal cycle resistance. Hoses for compressed hydrogen are used to refuel fuel cell vehicles and the like from hydrogen stations. Because hoses for compressed hydrogen are subjected to repeated temperature changes (thermal cycles) from below -40°C to above 90°C due to the filling and discharge of high-pressure hydrogen, they are required to have not only flexibility but also high thermal cycle resistance and pressure cycle resistance.

[0073] A high-pressure hydrogen hose is a hose containing a multilayer structure for the first purpose, where layer (BL) is in contact with the compressed gas and layer (CL) constitutes the outside of the hose.

[0074] The multilayer structure of the present invention is characterized by high heat resistance, excellent hydrogen barrier properties, extremely good resistance to pneumatic cycles and reduced pressure, and non-flammability. These characteristics make the multilayer structure particularly well suited for use in containers for storing gases under pressure.

[0075] The term "container" is used herein to refer to a hollow container. The containers of the present invention are, in particular, hollow containers for containing gas, preferably pressurized gas or compressed gas.

[0076] Advantageously, the containers obtained from the multilayer structure according to the present invention do not show any signs of rapid decompression (blistering) in either cyclic or static tests.

[0077] Therefore, a further object of the present invention is a container for storing or transporting gases, comprising the multilayer structure defined above.

[0078] Layer (BL) constitutes the inner layer of the container that comes into contact with the gas being transported or stored, and is hereafter referred to herein as the "inner layer" or "liner." Layer (CL) constitutes the outer layer of the container. All definitions and preferences given with respect to layer (BL), layer (CL), and multilayer structures apply to the container.

[0079] The container is preferably a pressure vessel, i.e., a container suitable for storing and / or transporting gases under pressure.

[0080] A vessel, or preferably a pressure vessel, comprises a hollow body and at least one boss. A boss, known to those skilled in the art, refers to an opening into which a closure is fitted, allowing the flow of gas or fluid into and out of the vessel. Bosses are typically made of metal.

[0081] The hollow body may have any shape suitable for storing gases, especially gases under pressure.

[0082] In certain conventional embodiments, the container has a cylindrical shape with bosses located at the ends. Often, the container has two bosses at each end of the cylindrical shape. The shape of the hollow body is determined by the desired application and is usually cylindrical, but not necessarily limited to a cylindrical shape. The hollow body may have a diameter of 10.0 cm to 1.0 m. The diameter may be at least 15.0 cm.

[0083] The length of the hollow body also depends on its end use. Hollow bodies can range in length from 50.0 cm to 10.0 m. These longer lengths are typically used for transporting gases. For example, containers in trucks are usually 1.0 m to 3.0 m in length.

[0084] The container of the present invention is 3.5 dm 3 ~5.0m 3 Furthermore, 5.0dm 3 ~1.0m 3 The internal volume of the container may be at least 10.0 dm³. 3 Furthermore, at least 15.0 dm 3 This is also acceptable. The internal volume is a maximum of 1.0 m³. 3 Furthermore, up to 0.5m 3 That's fine.

[0085] The container comprises a hollow body including, from the inside out, at least one barrier layer or liner which is the above-defined layer (BL), and at least one composite material layer which is the above-defined layer (CL) in contact with the at least one barrier layer. Layer (BL) is in contact with the gas contained within the container.

[0086] A liner is intended to provide a barrier between the fluid or gas and the layer (CL) to prevent leakage. Generally, the layer (CL) is provided around the liner to provide mechanical properties such as burst pressure resistance.

[0087] The container may be prepared according to any method known in the art.

[0088] For example, the liner can be manufactured by blow molding, tube extrusion, injection molding, welding, and / or rotational molding. In this case, the layer (CL) can be applied to the outer surface of the liner by wrapping a tape containing continuous reinforcing fibers and a poly(arylene sulfide) polymer around a hollow body manufactured from the liner.

[0089] Other manufacturing methods known in the art can also be used for the manufacture of pressure vessels.

[0090] Therefore, the present invention is a. The process of preparing a liner in the form of a hollow body; b. The process of preparing a tape containing continuous reinforcing fibers and poly(arylene sulfide) polymer; c. The process of wrapping the tape around the liner while consolidating it by heating; d. A step of cooling the material obtained at the end of step c to obtain a solid; This also relates to methods for manufacturing containers, including the method described above.

[0091] In this specification, the term “tape” is understood to refer to an elongated object having a longitudinal direction, width, thickness, and cross-sectional aspect ratio, i.e., the thickness-to-width ratio. The cross-section is defined as being substantially perpendicular to the longitudinal direction of the tape. The longitudinal or mechanical direction of the tape essentially corresponds to the orientation of the endless fibers. The length dimension of the tape is not particularly limited. It may exceed 10 km in length and depends mainly on the continuous fibers and the process used to manufacture the tape. Nevertheless, the tape can also be manufactured in smaller sizes to suit the requirements of the intended application.

[0092] Because thicker tapes are more difficult to wrap, they typically have a thickness of 100 to 500 micrometers. Thinner tapes have the disadvantage of requiring more wrapping to obtain a hollow body.

[0093] The support may be a liner. In that case, the support becomes part of the hollow body.

[0094] The wrapping can be done in the form of a tape containing continuous reinforcing fibers and a poly(arylene sulfide) polymer.

[0095] Consolidation is preferably carried out by heat supplied by a heating element such as a laser, such as an infrared laser, a high-temperature gas torch, or an oven. Post-annealing may be performed in some cases.

[0096] The vessel according to the present invention exhibits a nominal pressure of at least 2.5 MPa, typically at least 20.0 MPa, and more preferably at least 30.0 MPa. The nominal pressure may be up to 70.0 MPa, 100 MPa, and even 150.00 MPa or higher. Advantageously, the vessel according to the present invention has a nominal pressure of 20.0 to 70.0 MPa.

[0097] The storage of hydrogen gas in the container according to the present invention can reach a burst pressure of at least 157.5 MPa. Containers for storing compressed hydrogen typically require a nominal pressure of 35.0 MPa or 70.0 MPa. The burst pressures, as measured according to ECE R134, are typically up to 78.8 MPa and 157.5 MPa, respectively.

[0098] A further object of the present invention is a compressed gas in a container comprising the multilayer structure of the first object, wherein the compressed gas is in contact with the layer (BL). The gas is advantageously selected from the group consisting of hydrogen, oxygen, nitrogen, argon, helium, methane, propane, compressed natural gas, CO2, and ammonia.

[0099] The gas is typically at a pressure of at least 5.0 MPa, preferably at least 10.0 MPa. Depending on the gas, the pressure can be 150.0 MPa or less.

[0100] Another object of the present invention is a vehicle containing a container or compressed gas contained within a container.

[0101] A vehicle may be an automobile, truck, train, ship, urban transport vehicle, airplane, helicopter, or any other vehicle that can be powered by the conversion of gas to energy by any means.

[0102] The embodiments described above are illustrative and not limiting. Further embodiments are within the concept of the present invention. In addition, although the present invention is described in relation to specific embodiments, those skilled in the art will recognize that modifications can be made in form and detail without departing from the spirit and scope of the invention. [Examples]

[0103] raw materials PPS1 is Ryton® XE-5500BL, a polyphenylene sulfide polymer commercially available from Solvay Specialty Polymers USA, LLC, with a melt flow rate of 10 g / 10 min (5 kg, 315.6 °C).

[0104] PPS2 was synthesized in a 340-liter reactor using 41.3 kg of aqueous sodium hydrosulfide solution (57.0 wt%, Nouryan), 30.8 kg of aqueous sodium hydroxide solution (50.6 wt%, Columbus), 12.1 kg of sodium acetate (Jarchem), and 123.1 kg of N-methyl-2-pyrrolidone (Ashland). After dehydration, 58.6 kg of 1,4-dichlorobenzene and 0.108 kg of 1,2,4-trichlorobenzene were added under nitrogen pressure, and the sealed reactor was heated to a maximum temperature of 275°C. After adding an additional 7.7 kg of NMP, the mixture was gradually cooled to obtain granular PPS. This was rinsed with NMP, water, and acetic acid solution at 60°C to 75°C to obtain 35.3 kg of white granular PPS resin. The resin melt flow rate was 11 g / 10 min (5 kg, 315.6°C).

[0105] PPS3 is Ryton® QA200P poly(phenylene sulfide) polymer, a poly(phenylene sulfide) polymer commercially available from Solvay Specialty Polymers USA, LLC.

[0106] PA12 is Grilamid® L25 NZ, a commercially available product from EMS Chemie.

[0107] MTM(registered trademark) 57 is a carbon fiber / epoxy resin UD prepreg commercially available from Solvay SA.

[0108] Meltflow rate The melt flow rate of poly(aryl sulfide) polymers was measured in an extruded plastomer at 315.6°C after an equilibrium time of 5 minutes, using a 5 kg load and a 0.21 cm × 0.80 cm die, according to ASTM D1238, Procedure B.

[0109] Tensile test Tensile properties were measured according to ISO 527-2 using a sample that met the requirements of ISO 1BA, at a test speed of 5 mm / min.

[0110] Determination of H2 transmission coefficient Samples for hydrogen permeation testing were prepared as follows: To ensure the material was completely dry before injection molding onto the plate, the PPS polymer was dried overnight at 107°C in a drying oven with a desiccant at a dew point of -40°C.

[0111] The PA12 polymer sample was dried at 70°C.

[0112] Following the injection molding process guidelines recommended by the polymer supplier, the material was injection molded into 10cm × 10cm × 0.32cm plates using a 250-ton Sumitomo SE 250 EV-A HD all-electric injection molding machine. The machine had a 45mm screw size with a maximum screw speed of 250rpm and a maximum shot capacity of 0.34dm³. The machine had a maximum shot size of 21cm and a maximum injection pressure of 215MPa. The plates were annealed for 2 hours at a temperature 20°C above their glass transition temperature to ensure complete crystallinity before hydrogen permeation testing.

[0113] The molding conditions are summarized in the table below.

[0114] [Table 1]

[0115] The PPS1, PPS2, and PPS3 sheets were annealed at 110°C for 2 hours. The PA12 sheet was annealed at 70°C for 2 hours.

[0116] The sample obtained in this manner was placed in a sealed chamber, and the airtightness of the chamber was confirmed by applying 1 MPa of hydrogen to the supply side. The chamber was then adjusted to the test temperature. H2 was supplied to the supply side at 1 MPa. Synthetic air was supplied to the permeate side at a controlled rate, and H2 was measured using a calibrated Inficon Sentrac H2 leak detector until a stable value for H2 was obtained and a steady state was reliably reached.

[0117] The permeability coefficient was calculated considering the sample thickness, exposed surface area, H2 concentration, carrier gas flow rate, and pressure.

[0118] The results for mechanical properties and hydrogen permeability coefficient are shown in Table 1.

[0119] [Table 2]

[0120] The data in Table 1 shows that PPS1 and PPS2 have significantly lower permeability coefficients than aliphatic polyamides such as PA12, resulting in superior barrier properties.

[0121] The difference in permeability coefficients becomes increasingly pronounced with rising temperatures. Since gas containers under pressure are exposed to high temperatures, the low temperature dependence of the permeability coefficients of sheets manufactured from PPS1 and PPS2 is a significant advantage.

[0122] At the same time, PPS1 and PPS2 have a higher modulus of elasticity than PA12.

[0123] The combination of the above characteristics makes it possible to design thinner liners without compromising the barrier or mechanical properties of the container.

[0124] Static and dynamic blister testing for multilayer structures Manufacturing of the multilayer structures of Examples 1 and 2 Starting with a unidirectional PPS carbon fiber tape manufactured using commercially available PPS polymer sold by Solvay Specialty Polymers USA LLC under the trade name Ryton® QA200N and carbon fiber at a volume fraction of approximately 55%, a composite sample with a thickness of 4 mm was manufactured by pressing at 320°C, 2.5 MPa, and a holding time of 20 minutes.

[0125] Co-consolidation was performed on the PPS sheet samples PPS1 (Example 2) and PPS3 (Example 1) manufactured above, as well as the PPS / CF composite material sample, in a press machine with limited contact time (to simulate the conditions of the winding process) under the following operating conditions: mold preheating at 300°C; contact time of 3'; contact pressure of 0.7 MPa.

[0126] Manufacturing of the multilayer structure of Comparative Example 1 A multilayer structure containing a PA12 liner and a carbon fiber / epoxy resin reinforcing layer was manufactured by simultaneously curing a PA12 sheet with MTM(registered trademark) 57 carbon fiber / epoxy resin prepreg as follows: Four 150mm x 150mm plies of MTM(registered trademark) 57 were used as the 0 / 90 oriented reinforcing epoxy substrate.

[0127] A 125mm x 125mm square of polymer plaque PA12 was applied to an epoxy substrate. No special pretreatment was performed on the epoxy prepreg or polymer square.

[0128] All layup stacks were cured using standard vacuum bag consumables. Curing was performed in an oven under vacuum (less than 50 mmbar). Temperature was controlled using a Eurotherm controller for ramp, dwell, and cool-down. The curing temperature was 120°C and the curing time was 1 hour.

[0129] Exam conditions Dynamic cycling tests were performed on the samples from Examples 1 and 2 and Comparative Example 1 to detect blisters between the liner and the fiber-reinforced layer. The samples were introduced into the test apparatus and subjected to repeated pressurization and depressurization cycles as follows: ○ Adjust to 50±2℃ 〇 250 cycles completed • Pressurize to 44 MPa or higher • Maintain pressure of 44 MPa or higher for 24.8 minutes. • Reduce pressure to below 0.5 MPa at approximately 1,000 MPa / h • Maintain a pressure of 0.5 MPa or less for 24.8 minutes. ○ Reduce pressure to ambient pressure ○ Removal of samples from pressure vessels • Measure the weight after 60 minutes and 24 hours. We will report the weight difference before and after the test, as well as the occurrence of blisters.

[0130] At the end of the test, the samples were analyzed using RX tomography with a 150kV power supply and a 20μ focal spot. The presence of blisters at the liner (BL) / composite material (CL) interface was confirmed.

[0131] Static blister testing was performed under the following conditions: ○ Adjust to 50±2℃ Pressurize up to 87.5 MPa 〇 48 hour immersion (exposure) ○ Reduce pressure to ambient pressure as quickly as possible (Target: less than 1 second) We will report the weight difference before and after the test, as well as the occurrence of blisters.

[0132] The results are shown in Table 2.

[0133] [Table 3]

[0134] The results demonstrate that the mass of the multilayer structures of the present invention in Examples 1 and 2 is very stable. A weight loss was measured in the comparative multilayer structure containing a PA12 liner and a thermosetting carbon fiber composite material layer. The multilayer structures of the present invention maintain an excellent interface with no bubbles or blisters at the interface between the liner and the fiber-reinforced structural layer in both dynamic and static blister tests. Multiple blisters and cracks were observed in the multilayer structure of Comparative Example 1.

Claims

1. A multilayer structure comprising at least one gas barrier layer [layer (BL)] and at least one composite material layer [layer (CL)] in contact with the at least one gas barrier layer, - The layer (BL) contains poly(arylene sulfide) polymer, - The layer (CL) contains continuous reinforcing fibers and poly(arylene sulfide) polymer. Multilayer structure.

2. The poly(arylene sulfide) polymer is a compound of the following formulas: 【Chemistry 1】 (In the formula: - R is, in each case, C １ to C １２ alkyl group, C ７ to C ２４ alkylaryl group, C ７ to C ２４ aralkyl group, C ６ to C ２４ arylene group, and C ６ to C １８ is independently selected from the group consisting of aryloxy groups; -T represents a bond, -CO-, -SO ２ -, -O-, -C(CH ３ ) ２ phenyl, and -CH ２ Selected from the group consisting of: - i is independently 0 or an integer from 1 to 4 in each case; (In each case, j is independently 0 or an integer from 1 to 3.) The repeating unit (R) is represented by an expression selected from the following. ＰＡＳ The multilayer structure according to claim 1, comprising at least 50 mol% of ).

3. Repeating unit (R ＰＡＳ ) is equation (4): 【Chemistry 2】 (wherein R and i are as defined in claim 2, and preferably i is 0 in all cases in formula (4)) The multilayer structure according to claim 2, represented as shown.

4. A multilayer structure according to any one of claims 1 to 3, wherein the layer (BL) comprises the poly(arylene sulfide) polymer and at least one impact modifier in an amount of 1.0% to 25.0% by weight relative to the total weight of the layer (BL).

5. The multilayer structure according to any one of claims 1 to 4, wherein the continuous reinforcing fibers have a length of at least 5 mm.

6. The multilayer structure according to any one of claims 1 to 5, wherein the continuous reinforcing fibers are selected from the group consisting of glass fibers, carbon fibers, aramid fibers, and ceramic fibers.

7. The multilayer structure according to any one of claims 1 to 6, wherein the continuous reinforcing fibers in the layer (CL) are present in an amount of 15.0 to 80.0 volume% of the total volume of the layer (CL).

8. A multilayer structure according to any one of claims 1 to 7, comprising one or more layers (BL) and one or more layers (CL), preferably comprising one layer (BL) and one or more layers (CL).

9. An article for storing and / or transporting gas, comprising a multilayer structure according to any one of claims 1 to 8.

10. The article according to claim 9, in the form of a container or a hose.

11. The container according to claim 10, wherein layer (BL) constitutes the inner layer and layer (CL) constitutes the outer layer of the container or hose.

12. • Diameter of 10.0 cm to 1.0 m; - Lengths of 50.0 cm to 10.0 m; and 3.5 dm ３ ~5.0m ３ Internal volume; The container according to claim 10 or 11, having the shape of a hollow body having one or more of the following features.

13. A compressed gas contained in a container according to any one of claims 10 to 12, wherein the compressed gas is in contact with a layer (BL).

14. Hydrogen, oxygen, nitrogen, argon, helium, methane, propane, compressed natural gas, CO2 ２ The compressed gas according to claim 13, selected from the group consisting of ammonia.

15. The compressed gas according to claim 13 or 14, having a pressure of 1.0 MPa to 150.0 MPa.

16. A vehicle containing a container according to any one of claims 10 to 12 or a compressed gas according to any one of claims 13 to 15.

17. Use of the container according to any one of claims 10 to 12 for the storage or transport of compressed gas.

18. Use of the hose according to claim 10 or 11 for transporting gas, preferably compressed gas.

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