Hydrogen separation membrane, method for producing hydrogen separation membrane, and method for producing hydrogen gas

Abstract

A hydrogen separation membrane that combines high hydrogen permeability and high selectivity is provided. The hydrogen separation membrane includes a matrix resin, a hydrogen storage alloy dispersed in the matrix resin, and a binder resin present between the hydrogen storage alloy particles.

Description

[Technical Field]

[0001] The present invention relates to a hydrogen separation membrane, a method for producing a hydrogen separation membrane, and a method for producing hydrogen gas. [Background technology]

[0002] Hydrogen gas is used as a fuel for, for example, fuel cells and hydrogen engines. Various methods are known for producing hydrogen gas, but in all of them, hydrogen gas is produced as a mixed gas containing hydrogen and other gases such as carbon dioxide. Therefore, before use, the mixed gas is purified to extract high-purity hydrogen gas.

[0003] A method using a hydrogen separation membrane is known as a method for extracting high-purity hydrogen gas from a mixed gas. One type of hydrogen separation membrane is a metal membrane made of a metal having hydrogen storage capacity (see, for example, Patent Document 1). Such metal membranes are not only expensive but also prone to embrittlement due to hydrogen.

[0004] In response to this, hydrogen separation membranes have been proposed that combine a resin with a hydrogen storage alloy or a compound having hydrogen storage capacity. For example, Patent Document 2 discloses a hydrogen separation membrane having a separation function layer on a support membrane, the separation function layer containing a crosslinked polyamide and a compound having hydrogen storage capacity. This document describes that the separation function layer is formed by applying a solution containing a polyfunctional amine and a compound having hydrogen storage capacity onto the support membrane, and then further applying a solution containing a polyfunctional acid halide to cause interfacial polymerization of the polyfunctional amine and the polyfunctional halide.

[0005] Patent Document 3 discloses a hydrogen separation membrane made of a hydrogen storage alloy powder plated with Cu or Ni and a polymer compound that does not allow impurity gases other than hydrogen to pass through. This document describes that the hydrogen separation membrane can be obtained by forming the plated hydrogen storage alloy powder into a membrane using a press or the like, and then impregnating the polymer compound between the powder particles.

[0006] Non-Patent Document 1 proposes a hydrogen separation membrane made of hydrogen storage alloy powder LaNi5 and polyethylene. This document describes that the hydrogen separation membrane can be obtained by mixing polyethylene and LaNi5 in a ball mill and then forming the mixture into a membrane by hot pressing. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 2023-39770 [Patent Document 2] Japanese Patent Publication No. 2022-54573 [Patent Document 3] Special Publication No. 4-44604 [Non-patent literature]

[0008] [Non-Patent Document 1] DV Strugova et. al., International Journal of Hydrogen Energy, 43(2018) 12146-12152 Summary of the Invention [Problem to be solved by the invention]

[0009] However, the hydrogen separation membranes in Patent Document 3 and Non-Patent Document 1 both have a large thickness because hydrogen storage alloy powder is formed into a membrane by pressing, and therefore have the problem of a low hydrogen permeation rate and low hydrogen permeability for the entire membrane.

[0010] On the other hand, the separation functional layer of Patent Document 2 is formed by coating, so the film thickness can be made relatively thin, and it is thought that a certain level of hydrogen permeability can be obtained. However, in Patent Document 2, the separation functional layer is formed by interfacially polymerizing a polyfunctional amine and a polyfunctional halide in the presence of a compound having hydrogen storage capacity, and therefore, in order to avoid interfacial polymerization, it was not possible to increase the amount of the compound having hydrogen storage capacity beyond a certain level. Furthermore, the resulting separation functional layer had insufficient selectivity (hydrogen permeability / carbon dioxide permeability). As such, conventional hydrogen separation membranes containing a resin and a hydrogen storage alloy or a compound having hydrogen storage capacity did not achieve both high hydrogen permeability and high selectivity.

[0011] The present invention has been made in view of the above circumstances, and aims to provide a hydrogen separation membrane that achieves both high hydrogen permeability and high selectivity, a method for manufacturing a hydrogen separation membrane, and a method for manufacturing hydrogen gas. [Means for solving the problem]

[0012] The present invention relates to the following hydrogen separation membrane, a method for producing a hydrogen separation membrane, and a method for producing hydrogen gas. [1] A hydrogen separation membrane comprising: a matrix resin; a hydrogen storage alloy dispersed in the matrix resin; and a binder resin present between the hydrogen storage alloy. [2] The hydrogen separation membrane according to [1], wherein the matrix resin comprises a cured product of a thermosetting resin composition containing a thermosetting resin. [3] The hydrogen separation membrane according to [2], wherein the matrix resin has a glass transition temperature of 80°C or higher. [4] The matrix resin has a carbon dioxide permeability coefficient of 1.5 × 10 measured by a differential pressure method in accordance with JIS K 7126-1:2006 at a temperature of 80 °C and a supply pressure of 1 atmosphere. -17 mol m / (m 2 The hydrogen separation membrane according to any one of [1] to [3], wherein the hydrogen separation membrane has a surface area of ​​1.0 s·Pa or less. [5] The hydrogen separation membrane according to any one of [1] to [4], wherein the hydrogen storage alloy accounts for 55 mass % or more of the total mass of the hydrogen separation membrane. [6] The hydrogen separation membrane according to any one of [1] to [5], wherein the weight loss rate when the hydrogen separation membrane is heated to 600°C in an inert gas atmosphere and pyrolyzed is 30% by mass or less. [7] The hydrogen separation membrane according to any one of [1] to [6], which is a single layer. [8] The hydrogen separation membrane according to any one of [1] to [6], wherein the binder resin contains at least one resin selected from the group consisting of fluorine-based resins, diene-based rubbers, polyethylene oxide (PEO), polyolefin-based resins, urethane resins, phenolic resins, polyethers, polyamides, polyesters, vinyl resins, and acrylic acid-based copolymers. [9] The hydrogen separation membrane according to any one of [1] to [8], wherein the binder resin contains a fluorine-based resin.

[10] The hydrogen separation membrane according to any one of [1] to [9], which has a membrane thickness of 120 μm or less.

[11] A method for producing a hydrogen separation membrane, comprising the steps of: preparing a porous membrane containing a hydrogen storage alloy and a binder resin that adsorbs to the hydrogen storage alloy; and filling voids in the porous membrane with a matrix resin.

[12] A method for producing hydrogen gas, comprising the steps of: supplying a mixed gas containing hydrogen and a gas other than hydrogen to a space in contact with one side of the hydrogen separation membrane described in any one of [1] to

[10] ; and recovering a gas containing hydrogen from the space in contact with the other side of the hydrogen separation membrane. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a hydrogen separation membrane that achieves both high hydrogen permeability and high selectivity, a method for producing a hydrogen separation membrane, and a method for producing hydrogen gas. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic cross-sectional view of a hydrogen separation membrane according to one embodiment of the present invention. [Figure 2] 2A and 2B are schematic cross-sectional views showing a method for producing a hydrogen separation membrane according to one embodiment of the present invention. [Figure 3] 3A to 3C are monochrome processed SEM-EDX analysis images of the cross section of the prepared sample. DETAILED DESCRIPTION OF THE INVENTION

[0015] The inventors' investigations revealed that in the hydrogen separation membrane obtained by applying a mixed solution of a hydrogen storage alloy and a matrix resin, as shown in Patent Document 2, the hydrogen storage alloy is dispersed throughout the membrane and does not have a densely connected structure, which is thought to be why sufficient selectivity cannot be obtained.

[0016] In response to this, the present inventors conducted further studies and found that a hydrogen separation membrane having high hydrogen permeability and high selectivity can be obtained by producing a porous membrane containing a hydrogen storage alloy and a binder resin that binds to the hydrogen storage alloy, and then filling the voids in the porous membrane with a matrix resin.

[0017] The reason for this is not clear, but is thought to be as follows. The hydrogen separation membrane obtained by the above method has a structure in which hydrogen storage alloys are tightly bound together by a binder resin. Specifically, the hydrogen storage alloys are tightly bound together by the binder resin, forming long, connected paths. Hydrogen permeation is promoted through such paths, which increases hydrogen permeability and selectivity. Furthermore, by filling the voids in the porous membrane with a matrix resin, it becomes even more difficult for gases other than hydrogen to permeate through the membrane. This further increases selectivity.

[0018] That is, the hydrogen separation membrane of the present invention comprises a matrix resin, a hydrogen storage alloy dispersed in the matrix resin, and a binder resin present between the hydrogen storage alloy particles.

[0019] Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments. Furthermore, in this specification, a numerical range indicated using "to" means a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively.

[0020] 1. Hydrogen separation membrane FIG. 1 is a schematic cross-sectional view showing the structure of a hydrogen separation membrane 10 according to one embodiment of the present invention.

[0021] As shown in FIG. 1, the hydrogen separation membrane 10 includes a matrix resin 11A, a hydrogen storage alloy 12 dispersed in the matrix resin 11A, and a binder resin 11B present between the hydrogen storage alloys 12.

[0022] 1-1. Matrix resin 11A The type of matrix resin is not particularly limited, but it is preferable that the resin is impermeable to gases other than hydrogen gas (for example, carbon dioxide).

[0023] For example, the carbon dioxide permeability coefficient of the matrix resin is preferably lower than that of a porous membrane containing a hydrogen storage alloy and a binder resin bound thereto. Specifically, the carbon dioxide permeability coefficient of the matrix resin measured by a differential pressure method in accordance with JIS K 7126-1:2006 at a measurement temperature of 80°C and a supply pressure of 1 atmosphere is 5.5 × 10 -17 mol m / (m 2 ·s·Pa) or less, and -17 mol m / (m 2 The lower limit of the carbon dioxide permeability coefficient of the matrix resin 11A is not particularly limited, but is preferably 0 mol m / m 2 s Pa or more, and may be 1.0 × 10 -17 mol m / m 2 ·s·Pa or more.

[0024] The carbon dioxide permeability coefficient of the matrix resin can be measured by a differential pressure method in accordance with JIS K 7126-1: 2006. Specifically, it can be measured by the following procedure. 1) The matrix resin is formed into a film to be used as a sample piece. The thickness of the sample piece is measured. 2) The carbon dioxide permeability of the sample is measured by the differential pressure method. The measurement device is one specified in JIS K 7126-1:2006, such as GTR-21A-A, GTR-21A-B, or GTR-30XA manufactured by GTR Tech Co., Ltd. The measurement temperature is 80°C, and the supply pressure is 0.1 MPa (differential pressure 0.1 MPa). 3) Measured carbon dioxide permeability [mol / m 2 s Pa] was multiplied by the film thickness of the sample to obtain the carbon dioxide permeability coefficient [mol m / m 2 ·s·Pa] is calculated.

[0025] Such a matrix resin preferably includes a cured product of a curable resin composition containing a curable resin.

[0026] The curable resin contained in the curable resin composition may be a photocurable resin or a thermosetting resin. Among them, from the viewpoints of easily obtaining a cured product with high gas barrier properties and facilitating curing and molding, it is preferable that the curable resin contains a thermosetting resin.

[0027] The glass transition temperature of the matrix resin containing the cured product of the curable resin composition is preferably equal to or higher than the ambient temperature at which the hydrogen separation membrane is used. At temperatures higher than the glass transition temperature, the molecules of the matrix resin tend to be mobile, which reduces the gas barrier properties. In contrast, when the glass transition temperature of the matrix resin is equal to or higher than the ambient temperature at which the membrane is used, the gas barrier properties can be better maintained even at the ambient temperature at which the membrane is used, and high selectivity can be maintained. Specifically, the glass transition temperature of the matrix resin containing the cured product of the curable resin composition is preferably equal to or higher than 80°C, and more preferably between 80°C and 150°C. The glass transition temperature (Tg) of the matrix resin is measured in accordance with JIS K 7121:2012 using a differential scanning calorimeter (e.g., a DSC1 manufactured by Mettler-Toledo) at a heating rate of 20°C / min.

[0028] Examples of thermosetting resins include epoxy resins, phenolic resins, melamine resins, maleic acid resins, maleimide resins, urea resins, guanamine resins, aniline resins, urethane resins, oxazine resins, oxazoline resins, imide resins, acrylic resins having functional groups, and silicone resins having functional groups. Examples of functional groups possessed by acrylic resins and silicone resins include hydroxyl groups, methylol groups, carboxyl groups, epoxy groups, and amino groups. Of these, epoxy resins are preferred. The epoxy resin may be an aliphatic epoxy resin, an alicyclic epoxy resin, or an aromatic epoxy resin.

[0029] The epoxy resin may be an epoxy resin having two or more epoxy groups in one molecule, or an epoxy resin having three or more epoxy groups in one molecule. Among them, from the viewpoint of increasing the crosslink density and making it more impervious to gases other than hydrogen, an epoxy resin having three or more epoxy groups in one molecule is preferred.

[0030] Examples of epoxy resins having three or more epoxy groups in one molecule include phenol novolac epoxy resins, cresol novolac epoxy resins, triphenylmethane epoxy resins, dicyclopentadiene epoxy resins, bisphenol A epoxy resins, and tetramethylbisphenol F epoxy resins.

[0031] Among these, it is preferable to include an epoxy resin having three or more epoxy groups in one molecule and having a glycidylamine moiety, from the viewpoint of easily forming a cured product having good adhesive properties to the hydrogen storage alloy and the binder resin.

[0032] Examples of epoxy resins having three or more epoxy groups in one molecule and having a glycidyl amine moiety include epoxy resins that have a glycidyl amine moiety and may further have a glycidyl ether moiety, and are derived from a compound having two or more amino groups, or one or more amino groups and one or more hydroxyl groups.

[0033] Specific examples include epoxy resins having a glycidylamine moiety derived from a xylylenediamine such as meta-xylylenediamine or para-xylylenediamine, epoxy resins having a glycidylamine moiety derived from 1,3-bis(aminomethyl)cyclohexane, epoxy resins having a glycidylamine moiety derived from diaminodiphenylmethane, epoxy resins having a glycidylamine moiety and a glycidyl ether moiety derived from para-aminophenol, and epoxy resins having a glycidylamine moiety and a glycidyl ether moiety derived from 4-amino-3-methylphenol.

[0034] The content of the curable resin in the curable resin composition is, for example, preferably 10% by mass or more and 90% by mass or less, and more preferably 20% by mass or more and 80% by mass or less, relative to the total mass of the curable resin composition.

[0035] The curable resin composition may further contain a curing agent as needed. The curing agent is not particularly limited as long as it can cure the curable resin. For example, when the thermosetting resin is an epoxy resin, examples of the curing agent include acid anhydride curing agents (e.g., phthalic anhydride, maleic anhydride, nadic anhydride, methylnadic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, and succinic anhydride), amine curing agents, phenolic curing agents (e.g., bisphenol A, bisphenol F, and thiodiphenol), and polyaddition-type curing agents such as mercaptan curing agents, catalyst-type curing agents such as imidazole, and boric acid complex-type curing agents. Among these, amine curing agents are preferred from the viewpoint of high adhesion and heat resistance.

[0036] As the amine curing agent, any commonly used agent can be used without any particular limitation, and commercially available agents may also be used. Among them, from the viewpoint of curability, a polyfunctional amine curing agent having two or more functional groups is preferred. The polyfunctional amine curing agent may be either an aliphatic polyamine or an aromatic polyamine. From the viewpoint of high gas barrier properties and heat resistance, an aromatic polyamine is preferred.

[0037] Examples of aromatic polyamines include phenylenediamine, diaminodiphenylmethane, diaminodiphenyl ether, diaminodiphenyl sulfone, diaminophenyl benzoate, diaminodimethoxybiphenyl, 1,3-bis(3-aminophenoxy)benzene, diethyltoluenediamine, 2,2-bis[4-(4-aminophenoxyphenoxy)phenyl]propane (BAPP), and diaminonaphthalene.

[0038] The content of the curing agent in the curable resin composition is not particularly limited, and is preferably, for example, from 10% by mass to 90% by mass, and more preferably from 20% by mass to 80% by mass, relative to the total mass of the thermosetting resin.

[0039] The content of the matrix resin in the hydrogen separation membrane is not particularly limited, but is preferably 4% by mass or more and 16% by mass or less relative to the total mass of the hydrogen separation membrane. When the content of the matrix resin is 4% by mass or more, the membrane becomes less permeable to gases other than hydrogen gas, thereby further increasing selectivity. When the content of the matrix resin is 16% by mass or less, the content of the hydrogen storage alloy can be increased, thereby further increasing hydrogen permeability. From the same perspective, the content of the matrix resin is more preferably 4% by mass or more and 10% by mass or less.

[0040] 1-2. Binder Resin 11B The binder resin is present between the hydrogen storage alloy particles and binds the hydrogen storage alloy particles together.

[0041] The binder resin is not particularly limited as long as it binds the hydrogen storage alloy together. Examples of such binder resins include fluorine-based resins, diene-based rubbers such as styrene-butadiene rubber (SBR), polyethylene oxide (PEO), polyolefin-based resins (e.g., ethylene-based resins such as high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene, and ethylene-vinyl alcohol copolymers, propylene-based resins such as polypropylene, and methylpentene-based resins such as polymethylpentene), urethane resins, phenolic resins, polyethers (e.g., polyoxymethylene, polyoxyethylene, polyethersulfone, and polyetherketone), polyamides (e.g., nylon 6, nylon 66, and aramid resins), polyesters (e.g., polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthate, glyptal resin, and polylactic acid), vinyl resins (e.g., polyvinyl chloride, polyvinyl acetate, and polyvinyl alcohol), and acrylic acid-based copolymers (e.g., ethylene-acrylic acid copolymers and ethylene-methacrylic acid copolymers).

[0042] Among these, fluorine-based resins, styrene butadiene rubber (SBR) and polyethylene oxide (PEO) are preferred because of their high binding ability to hydrogen storage alloys, and fluorine-based resins are more preferred.

[0043] The type of fluororesin is not particularly limited, and may be a homopolymer of a fluorine-containing monomer such as vinylidene fluoride (VDF) or tetrafluoroethylene (TFE), or a copolymer of the fluorine-containing monomer with a monomer copolymerizable therewith. Examples of fluororesins include polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (PTFE).

[0044] The content of the binder resin in the hydrogen separation membrane is not particularly limited, but is preferably 4% by mass or more and 40% by mass or less relative to the total mass of the hydrogen separation membrane. When the content of the binder resin is 4% by mass or more, the hydrogen storage alloys can be more effectively bound together, thereby further increasing the hydrogen permeability. When the content of the binder resin is 40% by mass or less, a decrease in hydrogen permeability due to poor contact between the hydrogen storage alloys can be further suppressed. The content of the binder resin is more preferably 4% by mass or more and 10% by mass or less.

[0045] From the same viewpoint, the content of the binder resin in the hydrogen separation membrane is preferably 4% by mass or more and 40% by mass or less, and more preferably 4% by mass or more and 10% by mass or less, based on the total amount of the hydrogen storage alloy and the binder resin. The total amount of the hydrogen storage alloy and the binder resin is preferably 80% by mass or more and more preferably 90% by mass or more and 95% by mass or less, based on the total mass of the hydrogen separation membrane.

[0046] (Fluorine content by combustion ion chromatography) When the hydrogen separation membrane contains a fluororesin as a binder resin, the fluorine content measured by combustion ion chromatography is preferably 3% by mass to 40% by mass, and more preferably 3% by mass to 8% by mass, relative to the total mass of the hydrogen separation membrane. When the fluorine content is 3% by mass or more, a predetermined amount or more of the fluororesin is contained, which can better bind the hydrogen storage alloy and further increase the hydrogen permeability. When the fluorine content is 40% by mass or less, the amount of the fluororesin is not excessive, and the decrease in hydrogen permeability can be further suppressed.

[0047] The fluorine content of the hydrogen separation membrane can be determined by measuring the fluorine content at three arbitrarily selected points by combustion ion chromatography and calculating the average value. The measurement conditions can be as follows: [Automatic sample combustion device] Equipment: AQF-2100H (manufactured by Nitto Seiko Analytech Co., Ltd.) (electric furnace unit) Decomposition temperature: Inlet: 900℃, Outlet: 1000℃ Ar flow rate: 200mL / min O2 flow rate: 400mL / min (gas absorption unit) Absorption solution composition: 10 ml of ultrapure water [Ion Chromatograph] Device: IC-2010 (Tosoh Corporation) Separation column: TSKgel Super IC-Anion HS (4.6 mm ID x 100 mm) Eluent: 9.0 mM NaHCO3 + 1.0 mM Na2CO3 Flow rate: 1.0mL / min Column temperature: 40℃

[0048] 1-3. Hydrogen storage alloy particles 12 The hydrogen storage alloy is not particularly limited as long as it has the ability to store hydrogen, including conventionally known hydrogen storage alloys.

[0049] The hydrogen storage alloy is not particularly limited, but examples thereof include AB5 type (rare earth type) alloys, AB / A2B type alloys, and AB2 type (Laves phase) alloys. Examples of AB5 type (rare earth) alloys include LaNi5, LaNi4Cu, LaNi4Al, and LaNi 2.5 Co 2.5 , La 0.8 Nd 0.2 Ni2Co3, La 0.7 Nd 0.2 Ti 0.1 Ni 2.5 Co 2.4 Al 0.1 , La 0.8 Nd 0.2 Ni 2.5 Co 2.4 Si 0.1 , La 0.9 Zr 0.1 Ni 4.5 Al 0.5 , MmNi5 (Mm = Misch metal), MmNi 3.55 Co 0.75 Mn 0.4 Al 0.3 , MmNi 4.2 Mn 0.6 Al 0.2 , MmNi3Co 1.5 Al 0.5 , MmB x (x=4.55~4.76, B=Ni, Co, Mn, Al). Examples of AB / A2B type alloys include TiNi, Ti2Ni, TiMn2, Ti2Ni-TiNi-based multi-component alloys (partial replacement of Ni with V, Cr, Zr, Mn, Co, Cu, Fe, etc.); Ti 1-y Zr y Ni x (x=0.5~1.45, y=0~1), TiFe, TiCo, ZrCo, ZrNi, Mg2Ni, and Zr2Ni. Examples of AB2 type (Laves phase) alloys include Ti 2-x Zr x V 4-y Ni y , Ti 1-x Cr x V 2-y Ni y , ZrV 0.4 Ni1.6 , ZrMn 0.6 Cr 0.2 Ni 1.2 , Ti 17 Zr 15 V 22 Ni 39 Cr7, LaNi2, CeNi2, HfMn2, NbZn2, ScFe2, TiCr2, ZrNi2, ZrCr2, LaMg2, LaAl2, CaAl2, CeCo2, TiCo2, YNi2, ZrV2, ZrCo2, ZrZn2, BaMg2, CaLi2, CaMg2, NbFe2, TiMn2, ZrMn2, ZrAl2, and ZrCo2. These hydrogen storage alloys may be contained alone or in combination.

[0050] In this embodiment, the AB5 type (rare earth) alloy is preferred from the viewpoint of fast hydrogen absorption and desorption.

[0051] The shape of the hydrogen storage alloy is not particularly limited, but is preferably particulate. Furthermore, particulates are not limited to spherical shapes, and include irregular shapes such as those obtained by pulverization. The average particle size of the hydrogen storage alloy can be, for example, 0.01 μm to 2 mm, preferably 0.1 μm to 2 mm, and more preferably 0.1 μm to 100 μm. When the average particle size of the hydrogen storage alloy is 0.01 μm or more, handling can be improved, for example, when mixing with a binder resin to prepare a slurry. When the average particle size of the hydrogen storage alloy is 2 mm or less, the hydrogen storage alloy particles tend to aggregate more easily, making it easier to form a densely aggregated structure in the hydrogen separation membrane. The average particle size of the hydrogen storage alloy is the particle size (median size (D50)) at 50% cumulative volume distribution determined by laser diffraction / scattering, and can be measured using, for example, a Microtrac particle size distribution analyzer (e.g., Microtrac particle size distribution analyzer MT3300EXII, manufactured by Microtrac-Bell).

[0052] The content of the hydrogen storage alloy in the hydrogen separation membrane is not particularly limited, but is preferably 55% by mass or more relative to the total mass of the hydrogen separation membrane. When the content of the hydrogen storage alloy is 55% by mass or more, hydrogen permeability can be further increased. When the content of the hydrogen storage alloy is 92% by mass or less, poor filling of the matrix resin is less likely to occur, and a decrease in selectivity can be further suppressed. The content of the hydrogen storage alloy in the hydrogen separation membrane is more preferably 80% by mass or more and 92% by mass or less.

[0053] From the same viewpoint, the content of the hydrogen storage alloy in the hydrogen separation membrane is preferably 60% by mass or more and 96% by mass or less, more preferably 90% by mass or more and 96% by mass or less, based on the total amount of the hydrogen storage alloy and the binder resin.

[0054] 1-4.Other The hydrogen separation membrane may be composed of layers containing the above-mentioned components, or may further contain other layers. In particular, from the viewpoint of further increasing hydrogen permeability, it is preferable that the hydrogen separation membrane be composed of layers containing the above-mentioned components, i.e., be a single layer.

[0055] 1-5.Physical properties 1-5-1. Hydrogen permeability and selectivity The hydrogen permeability measured by the differential pressure method in accordance with JIS K 7126-1:2006 for hydrogen separation membranes at a measurement temperature of 80°C and a supply pressure of 1 atmosphere is 7.5 x 10 -11 mol / m 2 s Pa or more, and 1.0×10 -10 mol / m 2 s Pa or more is more preferable, and 1.5×10 -8 mol / m 2 It is more preferable that the hydrogen permeability of the hydrogen separation membrane is 7.5×10 s Pa or more. -11 mol / m 2s Pa or more, the hydrogen permeability can be sufficiently increased, and the hydrogen separation membrane can function satisfactorily. From the same viewpoint, the upper limit of the hydrogen permeability of the hydrogen separation membrane is not particularly limited, but it is possible to set the upper limit to, for example, 3.5×10 -6 mol / m 2 ·s·Pa or less. The hydrogen permeability coefficient of the hydrogen separation membrane measured by the above method is 1.0 × 10 -14 mol m / m 2 ·s·Pa or more is preferable, and 1.2×10 -12 mol m / m 2 ·s·Pa or more 2.5×10 -10 mol m / m 2 ·s·Pa or less is more preferable.

[0056] On the other hand, the carbon dioxide permeability of the hydrogen separation membrane measured by the above method is 1.5 × 10 -11 mol / m 2 ·s·Pa or less is preferable, and 1.0×10 -11 mol / m 2 s Pa or less. When the carbon dioxide permeability of the hydrogen separation membrane is in the above range, the selectivity can be further improved. The lower limit of the carbon dioxide permeability of the hydrogen separation membrane is, for example, 0 mol / m 2 The carbon dioxide permeability coefficient of the hydrogen separation membrane measured by the above method can be 9.5×10 -16 mol m / m 2 ·s·Pa or less is preferable, and 1.0×10 -16 mol m / m 2 ·s·Pa or less is more preferable.

[0057] Furthermore, the selectivity represented by the following formula (1) is preferably 50 or more. When the selectivity represented by formula (1) is 50 or more, for example, a hydrogen-containing gas can be more selectively permeated from a mixed gas containing hydrogen and other gases. The selectivity is more preferably 250 or more, even more preferably 1000 or more, and even more preferably 10000 or more. The upper limit of the selectivity is not particularly limited, but can be, for example, 20000 or less. Equation (1): Selectivity = hydrogen permeability [mol / m 2 ·s·Pa] / carbon dioxide permeability [mol / m 2 ·s·Pa]

[0058] The hydrogen permeability and selectivity of a hydrogen separation membrane can be adjusted by, for example, the content of the hydrogen storage alloy, the content ratio of the hydrogen storage alloy to the total amount of the hydrogen storage alloy and binder resin, the type of binder resin, the type of matrix resin, the membrane thickness, etc. For example, increasing the content or content ratio of the hydrogen storage alloy tends to increase both the hydrogen permeability and selectivity. Furthermore, decreasing the membrane thickness tends to increase the hydrogen permeability. Furthermore, if the matrix resin has high barrier properties against gases other than hydrogen gas, the selectivity tends to increase.

[0059] 1-5-2. Cross-sectional area ratio When a field of view is taken in a 100-150 μm range perpendicular to the membrane thickness direction and the center of the membrane thickness is included in the cross section of the hydrogen separation membrane, the area ratio of the elements constituting the hydrogen storage alloy to the total area of ​​the hydrogen separation membrane in the field of view obtained by scanning electron microscopy-energy dispersive X-ray spectroscopy is defined as the area ratio of the hydrogen storage alloy [%]. When measurements are taken at five randomly selected non-overlapping fields, the average area ratio of the hydrogen storage alloy is preferably 20% to 70%, and more preferably 40% to 70%. When the area ratio is 20% or more, the hydrogen storage alloy content is above a predetermined level, thereby further improving hydrogen permeability and selectivity. When the area ratio is 70% or less, a decrease in selectivity due to, for example, insufficient filling of the matrix resin can be suppressed.

[0060] Furthermore, when the area ratio of the fluorine region to the total area of ​​the hydrogen separation membrane in the above field of view is defined as the fluororesin area ratio [%], the average value of the fluororesin area ratio when measured at any five locations whose fields of view do not overlap is preferably 10% to 65% and more preferably 10% to 20%. When the area ratio is 10% or more, it is easier to form a structure in which the hydrogen storage alloy particles are closely bonded together, thereby further improving hydrogen permeability and selectivity. When the area ratio is 65% or less, it is possible to further suppress a decrease in hydrogen permeability and selectivity due to hindered contact between the hydrogen storage alloy particles.

[0061] Furthermore, when the area ratio of the region of the elements constituting the matrix resin to the total area of ​​the hydrogen separation membrane within the field of view is defined as the area ratio of the matrix resin [%], the average area ratio of the matrix resin measured at any five locations whose fields of view do not overlap is preferably 10% to 45%, and more preferably 20% to 40%. When the area ratio is 10% or more, poor filling of the matrix resin can be further suppressed, thereby further improving selectivity. When the area ratio is 45% or less, the proportion of the hydrogen storage alloy can be made greater than a predetermined level, thereby further improving hydrogen permeability.

[0062] The cross-sectional area ratio of each component in the cross section can be measured by scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDX). Specifically, it can be measured by the following procedure. (Sample preparation) The hydrogen separation membrane was cut into strips measuring 1 mm x 5 mm, and metallic Os was deposited on it to ensure electrical conductivity.Then, the cross section of the hydrogen separation membrane was extracted by ion milling (accelerating voltage 4 kV). (SEM-EDX measurement) Next, the field of view is adjusted so that the range of 100 to 150 μm is included in the direction perpendicular to the membrane thickness direction, and the center of the membrane thickness of the hydrogen separation membrane is included in the membrane thickness direction. Next, when the above field of view is analyzed using a scanning electron microscope-energy dispersive X-ray spectroscopy, the regions corresponding to the hydrogen storage alloy, binder resin, and matrix resin are identified, and the area ratio [%] of each identified region to the total area of ​​the hydrogen separation membrane in the above field of view is measured. This measurement is carried out for any five locations in the field of view that do not overlap each other, and the average area ratio for each region is calculated.

[0063] Each region can be identified based on the following criteria. The area where an element constituting the hydrogen storage alloy (for example, Ni in the case of LaNi4Al) is detected is defined as the area where the hydrogen storage alloy exists. The area where the elements constituting the binder resin are detected is defined as the area where the binder resin is present. For example, if the binder resin is a fluorine-based resin, the area where fluorine is detected is defined as the area where the fluorine-based resin is present. The area where the elements constituting the matrix resin are detected is defined as the area where the matrix resin exists. For example, if the matrix resin contains a cured product of a thermosetting resin composition containing an epoxy resin and an amine curing agent, the area where nitrogen derived from the amine curing agent and oxygen derived from the epoxy resin exist can be defined as the area where the matrix resin exists.

[0064] When the binder resin is a resin other than a fluorine-based resin, the region where the binder resin is present can also be identified by the following method. When the binder resin and the matrix resin share the same constituent elements (for example, PEO and epoxy resin), the boundary can be identified by the density of the common element (for example, oxygen). On the other hand, when the constituent elements of the binder resin are not the same as those of the matrix resin (for example, SBR and epoxy resin), the region where carbon is detected other than the region where the hydrogen storage alloy is present and the region where the matrix resin is present can be considered to be the region of the binder resin.

[0065] 1-5-3.Film Thickness The thickness of the hydrogen separation membrane is not particularly limited, but is preferably thin from the viewpoint of increasing hydrogen permeability. For example, the thickness of the hydrogen separation membrane is preferably 120 μm or less, and more preferably 100 μm or less. The lower limit of the thickness of the hydrogen separation membrane is not particularly limited, but can be, for example, 15 μm or more.

[0066] The thickness of the hydrogen separation membrane can be determined by measuring the membrane thickness at five arbitrarily selected points using an indicator (ID-S112PX2, manufactured by Mitutoyo) and calculating the average value.

[0067] 1-5-4. Density The density of the hydrogen separation membrane is not particularly limited, but is preferably 2.5 g / cm 3 It is preferable that the density of the hydrogen separation membrane is 2.5 g / cm or more. 3 If the density is 3.5 g / cm or more, the hydrogen permeability can be further increased due to the high content of the hydrogen storage alloy. 3 The upper limit of the density of the hydrogen separation membrane is not particularly limited, but is, for example, 4.2 g / cm 3 It can be as follows:

[0068] The density of the hydrogen separation membrane can be measured by the following procedure. The hydrogen separation membrane is punched out with a circular punch having a diameter of 14 mm to obtain a sample piece. The weight of the obtained sample piece is measured using an analytical balance (Shimadzu Corporation, AP224X). The volume is then calculated from the area of ​​the sample piece and the membrane thickness, and the weight is divided by the volume to calculate the density. This measurement is performed three times, and the average value of the three measurements is used as the density.

[0069] The density of the hydrogen separation membrane can be adjusted mainly by the content of the hydrogen storage alloy. For example, the density tends to increase as the content of the hydrogen storage alloy in the hydrogen separation membrane increases.

[0070] 1-5-5. Weight reduction rate When the hydrogen separation membrane is heated to 600°C in an inert gas atmosphere and thermally decomposed, the weight loss rate is preferably, for example, 30% by mass or less. If the weight loss rate of the hydrogen separation membrane is 30% by mass or less, the hydrogen separation membrane contains a large amount of hydrogen storage alloy (a component that does not thermally decompose), which allows for a higher hydrogen permeability. From the same perspective, the weight loss rate is more preferably 10% by mass or less. The lower limit of the weight loss rate of the hydrogen separation membrane is not particularly limited, but can be, for example, 2% by mass.

[0071] The weight loss rate of the hydrogen separation membrane can be measured, for example, by the following procedure. A 10 mg sample of hydrogen separation membrane is weighed out using a precision balance (e.g., Mettler Toledo XS105) and used as a sample piece. The sample piece is placed on a platinum pan and heated from room temperature to 600°C in a nitrogen gas atmosphere using a differential thermal and thermogravimetric simultaneous analyzer (e.g., Shimadzu DTG-60H) with alumina as the standard substance, at a nitrogen gas flow rate of 200 mL / min and a heating rate of 20 K / min. The weight loss rate is calculated using the formula: weight loss rate [%] = (W0 - W1) × 100 / W0, where W0 is the weight before heating and W1 is the weight after heating.

[0072] The weight loss rate of the hydrogen separation membrane can be adjusted mainly by the content of the hydrogen storage alloy. For example, the greater the amount of hydrogen storage alloy in the hydrogen separation membrane, the smaller the weight loss rate.

[0073] 2. Manufacturing method of hydrogen separation membrane 2A and 2B are schematic cross-sectional views showing a method for manufacturing the hydrogen separation membrane 10. FIG.

[0074] The hydrogen separation membrane can be manufactured by any method. In this embodiment, the hydrogen separation membrane 10 can be manufactured through a step of manufacturing a porous membrane 10A containing a hydrogen storage alloy 12 and a binder resin 11B (porous membrane manufacturing step, see FIG. 2A), and a step of filling the voids 13 of the porous membrane 10A with a matrix resin 11A (resin filling step, see FIG. 2B).

[0075] 2-1.Porous membrane manufacturing process First, a porous film containing a hydrogen storage alloy and a binder resin is prepared (see FIG. 2A).

[0076] The porous membrane can be produced by any method. For example, a method of molding a hydrogen storage alloy and a binder resin by pressing or the like, or a method of applying a slurry containing a hydrogen storage alloy, a binder resin, and a solvent can be mentioned. Among them, the method of applying a slurry containing a hydrogen storage alloy, a binder resin, and a solvent is preferred from the viewpoint of easily forming a thin porous membrane.

[0077] The slurry may be prepared by simultaneously mixing the hydrogen storage alloy, binder resin, and solvent, or by mixing the binder resin and solvent and then adding the hydrogen storage alloy and mixing them together. In particular, from the viewpoint of making it easier to bind the hydrogen storage alloy with the binder resin, it is preferable to mix the binder resin and solvent and then add the hydrogen storage alloy and mix them together to prepare a slurry.

[0078] That is, it is preferable to prepare a porous membrane through the steps of: 1) obtaining a solution (binder solution) containing a binder resin and a solvent capable of dispersing or dissolving the binder resin; and 2) mixing the obtained binder solution with a hydrogen storage alloy, followed by molding and drying.

[0079] The solvent used to prepare the binder solution is not particularly limited as long as it can disperse or dissolve the binder resin, and water or an organic solvent can be used, such as acetone, ethanol, or N-methyl-2-pyrrolidone (NMP).

[0080] Methods for forming the mixture (slurry) of the binder solution and the hydrogen storage alloy include known methods such as spraying, screen printing, gravure printing, die coating, doctor blade, and ink jet printing.

[0081] The drying temperature may be any temperature that can volatilize and remove the solvent in the slurry to some extent, and may be, for example, 80°C or higher and 110°C or lower.

[0082] 2-2.Resin filling process Next, the voids in the resulting porous film are filled with a matrix resin (see FIG. 2B).

[0083] For example, when the matrix resin contains a cured product of a thermosetting resin composition, the matrix resin can be filled by impregnating the voids of the porous membrane with the thermosetting resin composition and then thermally curing the composition. The impregnation method is not particularly limited, and may be a method of immersing the porous membrane in the thermosetting resin composition, or a method of applying the thermosetting resin composition to the surface of the porous membrane. This allows the cured product of the thermosetting composition to be filled into the voids of the porous membrane.

[0084] The heat curing temperature is not particularly limited as long as it is a temperature at which the thermosetting resin composition cures, but it is preferably lower than the glass transition temperature of the binder resin, for example, the heat curing temperature is preferably 50°C or higher and 200°C or lower.

[0085] 3.Applications The hydrogen separation membrane described above has excellent hydrogen permeability and selectivity, and therefore can be preferably used for separating or recovering a hydrogen-containing gas from a mixed gas containing hydrogen and a gas other than hydrogen (e.g., carbon dioxide, oxygen, nitrogen, etc.).

[0086] 4. Hydrogen gas production method The above-described hydrogen separation membrane can be applied to, for example, a method for producing hydrogen gas.

[0087] That is, the method for producing hydrogen gas according to this embodiment includes a step of supplying a mixed gas containing hydrogen and a gas other than hydrogen to a space in contact with one side of a hydrogen separation membrane, and a step of recovering a gas containing hydrogen from the space in contact with the other side of the hydrogen separation membrane.

[0088] The type of gas other than hydrogen is not particularly limited, but examples include at least one gas selected from carbon dioxide, oxygen, nitrogen, and methane.

[0089] The supply pressure of the mixed gas is not particularly limited, but can be, for example, 0.1 MPa or more and 10 MPa or less. By setting the gas supply pressure to 0.1 MPa or more, the gas permeation rate increases, and by setting it to 10 MPa or less, deformation of the hydrogen separation membrane due to pressure can be further suppressed.

[0090] The supply temperature of the mixed gas may be set depending on the application of the hydrogen gas, and is not particularly limited, but may be, for example, 80° C. or higher and 100° C. or lower. By setting the supply temperature of the mixed gas within the above range, the recovered hydrogen-containing gas can be preferably used, for example, as fuel for a fuel cell.

[0091] According to the above-described manufacturing method, by using the above-described hydrogen separation membrane, it is possible to efficiently separate and recover a hydrogen-containing gas from a mixed gas containing hydrogen and a gas other than hydrogen, i.e., it is possible to recover a gas having a higher hydrogen / gas other than hydrogen molar ratio than the supplied mixed gas.

[0092] The obtained hydrogen gas can be used for various purposes, for example, as a fuel for fuel cells, hydrogen engines, etc. [Example]

[0093] The present invention will be specifically explained below with reference to examples, but the present invention is not limited to these examples.

[0094] 1. Material Preparation 1-1.Hydrogen storage alloy LaNi4Al (manufactured by Kojundo Chemical Laboratory, average particle size 10.2 μm) The average particle size is the particle size (median diameter (D50)) at an integrated value of 50% in the volume distribution, measured using a Microtrac particle size distribution analyzer MT3300EXII (manufactured by Microtrac Bell).

[0095] 1-2. Binder resin PVDF: Polyvinylidene fluoride (Kureha, KF#850) SBR: Styrene butadiene rubber dispersion (solid content 40% by mass) PEO: Polyethylene oxide (Sigma-Aldrich)

[0096] 1-3. Matrix resin (thermosetting resin) Epoxy resin (Mitsubishi Gas Chemical Company, Inc., Maxiev (registered trademark), M-100, an epoxy compound having four epoxy groups in one molecule and a glycidylamine moiety)

[0097] (hardening agent) Polyamine resin (Mitsubishi Gas Chemical Company, Inc., Maxieve (registered trademark), C-93, polyamine resin)

[0098] The glass transition temperature (Tg) of the cured product of a mixture of Maxieve (registered trademark) M-100 and Maxieve (registered trademark) C-93 in a mass ratio of 5:16 is 108°C. The glass transition temperature (Tg) is a value measured in accordance with JIS K 7121:2012 using a differential scanning calorimeter (e.g., DSC1 manufactured by Mettler Toledo) at a heating rate of 20°C / min. The carbon dioxide permeability coefficient (80°C, differential pressure 1 atmosphere) of the cured product measured by the differential pressure method in accordance with JIS K 7126-1:2006 was 1.5 x 10 -17 (mol m / m 2 ·s·Pa).

[0099] 2. Sample Preparation [Preparation of sample 1] (Preparation of Slurry) PVDF (KF#850, manufactured by Kureha) was added to N-methyl-2-pyrrolidone (NMP, manufactured by Nippon Refine Co., Ltd.) so that the concentration was 20% by mass, and dissolved at 50° C. to obtain a binder resin solution. Next, LaNi4Al was added to the binder resin solution so that the mass ratio of PVDF to the hydrogen storage alloy LaNi4Al was PVDF:LaNi4Al = 60:40, and the mixture was kneaded using a mashine (AER-300, manufactured by Shinki Co., Ltd.) at 2000 rpm for 2 minutes to prepare a slurry.

[0100] (Preparation of porous membrane) The obtained slurry was applied to a PET film (Lumirror S10, manufactured by Toray Industries, Inc., thickness 100 μm) using an applicator. Then, the film was heat-treated at 110°C for 30 minutes in an N2 atmosphere in an incubator (HT220S, manufactured by Kusumoto Chemicals Co., Ltd.) to evaporate the NMP, thereby obtaining a porous film.

[0101] (Filling and curing of thermosetting resin composition) An epoxy resin (Mitsubishi Gas Chemical Company, Inc., Maxieve (registered trademark), M-100) and a polyamine resin (Mitsubishi Gas Chemical Company, Inc., Maxieve (registered trademark), C-93) were mixed in a mass ratio of 5:16 to prepare a thermosetting resin composition. Next, the thermosetting composition was applied to one side of the porous membrane prepared above using a bar coater (non-wire bar coater φ10×250 mm, number #3, manufactured by AS ONE Corporation) and impregnated therein, and then heat-treated in the incubator at 80°C for 30 minutes to be thermally cured, thereby obtaining Sample 1.

[0102] [Preparation of Samples 2 to 4] Samples 2 to 4 were obtained in the same manner as Sample 1, except that the mass ratio of PVDF to the hydrogen storage alloy LaNi4Al was changed as shown in Table 1.

[0103] [Preparation of sample 5] (Preparation of Slurry) As a dispersion of a binder resin, an SBR dispersion (solid content concentration: 40% by mass) was prepared. To this, the hydrogen storage alloy LaNi4Al and the thickener sodium carboxymethylcellulose (CMC) were added so that the mass ratio of SBR:LaNi4Al:CMC was 3:97:1, and the mixture was kneaded in a masher (Thinky, AER-300) at 2000 rpm for 2 minutes to obtain a slurry.

[0104] (Preparation of porous membrane) The obtained slurry was applied to a PET film (Lumirror S10, manufactured by Toray Industries, Inc., thickness 100 μm) using an applicator, and then dried by heat treatment at 80°C for 30 minutes in a N2 atmosphere using an incubator (HT220S, manufactured by Kusumoto Chemicals Co., Ltd.) to obtain a porous film.

[0105] (Filling and curing of thermosetting resin composition) An epoxy resin (Mitsubishi Gas Chemical Company, Inc., Maxieve (registered trademark), M-100) and a polyamine resin (Mitsubishi Gas Chemical Company, Inc., Maxieve (registered trademark), C-93) were mixed in a mass ratio of 5:16 to prepare a thermosetting resin composition. Next, the surface of the porous membrane prepared above was coated and impregnated with the thermosetting composition using a bar coater (non-wire bar coater φ10×250 mm, number #3, manufactured by AS ONE Corporation), and then heat-treated in the incubator at 80°C for 30 minutes to be thermally cured, thereby obtaining Sample 5.

[0106] [Preparation of sample 6] (Preparation of Slurry) Polyethylene oxide (PEO, manufactured by Sigma-Aldrich) was added to and dissolved in ion-exchanged water to a concentration of 10% by mass to obtain a binder resin solution. Next, LaNi4Al was added to the binder resin solution so that the mass ratio of PEO to the hydrogen storage alloy LaNi4Al was PEO:LaNi4Al = 20:80, and the mixture was kneaded using a mixer (Thinky, AER-300) at 2000 rpm for 2 minutes to obtain a slurry.

[0107] (Preparation of porous membrane) The obtained slurry was applied to a PET film (Lumirror S10, manufactured by Toray Industries, Inc., thickness 100 μm) using an applicator, and then dried by heat treatment at 80°C for 30 minutes in a N2 atmosphere using an incubator (HT220S, manufactured by Kusumoto Chemicals Co., Ltd.) to obtain a porous film.

[0108] (Filling and curing of thermosetting resin composition) An epoxy resin (Mitsubishi Gas Chemical Company, Inc., Maxieve (registered trademark), M-100) and a polyamine resin (Mitsubishi Gas Chemical Company, Inc., Maxieve (registered trademark), C-93) were mixed in a mass ratio of 5:16 to prepare a thermosetting resin composition. Next, the surface of the porous membrane prepared above was coated with and impregnated with the thermosetting composition using a bar coater (non-wire bar coater φ10×250 mm, number #3, manufactured by AS ONE Corporation), and then heat-treated in the incubator at 80°C for 30 minutes to be thermally cured, thereby obtaining Sample 6.

[0109] [Preparation of sample 7] Epoxy resin (Mitsubishi Gas Chemical Company, Inc., Maxieve (registered trademark), M-100), polyamine resin (Mitsubishi Gas Chemical Company, Inc., Maxieve (registered trademark), C-93), and LaNi4Al were mixed in a mass ratio of epoxy resin:LaNi4Al = 60:40. Next, the mixture was applied to a Teflon sheet (Naflon (registered trademark), manufactured by Nichias Corporation, thickness 50 μm) using a bar coater (non-wire bar coater φ10×250 mm, count #20, manufactured by AS ONE Corporation). Thereafter, heat treatment was carried out at 80° C. for 30 minutes in an incubator (HT220S, manufactured by Kusumoto Chemicals Co., Ltd.) to prepare Sample 7.

[0110] [Preparation of Samples 8 and 9] Samples 8 and 9 were prepared in the same manner as Sample 7, except that the mass ratio of the hydrogen storage alloy LaNi4Al to the epoxy resin was changed as shown in Table 1.

[0111] [Preparation of Sample 10] A mixture of epoxy resin (Mitsubishi Gas Chemical Company, Inc., Maxieve (registered trademark), M-100) and polyamine resin (Mitsubishi Gas Chemical Company, Inc., Maxieve (registered trademark), C-93) was further coated onto the surface of Sample 9 using a bar coater (As One Corporation, non-wire bar coater φ10 × 250 mm, count #3), and the mixture was heat-treated at 80°C for 30 minutes in an incubator (Kusumoto Chemicals Co., Ltd., HT220S) to obtain Sample 10.

[0112] [Preparation of Sample 11] An epoxy resin (Mitsubishi Gas Chemical Company, Inc., Maxieve (registered trademark), M-100) and a polyamine resin (Mitsubishi Gas Chemical Company, Inc., Maxieve (registered trademark), C-93) were mixed in a mass ratio of 5:16 to prepare a thermosetting resin composition. The thermosetting composition was applied to a Teflon sheet (Naflon (registered trademark), manufactured by Nichias Corporation, thickness 50 μm) using a bar coater (non-wire bar coater, φ10 × 250 mm, count #12, manufactured by AS ONE Corporation). The sheet was then heat-treated at 80°C for 30 minutes in an incubator (HT220S, manufactured by Kusumoto Chemicals Co., Ltd.) to obtain an epoxy resin film (Sample 11).

[0113] 3. Evaluation The following measurements were carried out on each of the prepared samples 1 to 11.

[0114] 3-1. Film formability The samples prepared above were marked with a circle when they were self-supporting as a film, and marked with an x ​​when they were not self-supporting as a film and could not be evaluated.

[0115] 3-2.Film Thickness The film thickness of five arbitrarily selected points on the prepared sample was measured using an indicator (ID-S112PX2, manufactured by Mitutoyo), and the average value was taken as the film thickness.

[0116] 3-3.Density The prepared sample was punched out with a circular punch having a diameter of 14 mm to obtain a sample piece. The weight of the obtained sample piece was measured using an analytical balance (Shimadzu Corporation, AP224X). The film thickness of the sample piece was also measured in the same manner as in 3-2. The volume was then calculated from the area and film thickness of the sample piece, and the weight was divided by the volume to calculate the density. The above measurement was carried out three times for each sample, and the average value of the three measurements was taken as the density.

[0117] 3-4. Fluorine content The fluorine content relative to the total mass of the sample was measured for three randomly selected points by combustion ion chromatography, and the average value was taken as the fluorine content. The measurement conditions were as follows: [Automatic sample combustion device] Equipment: AQF-2100H (manufactured by Nitto Seiko Analytech Co., Ltd.) (electric furnace unit) Decomposition temperature: Inlet: 900℃, Outlet: 1000℃ Ar flow rate: 200mL / min O2 flow rate: 400mL / min (gas absorption unit) Absorption solution composition: 10 ml of ultrapure water [Ion Chromatograph] Device: IC-2010 (Tosoh Corporation) Separation column: TSKgel Super IC-Anion HS (4.6 mm ID x 100 mm) Eluent: 9.0 mM NaHCO3 + 1.0 mM Na2CO3 Flow rate: 1.0mL / min Column temperature: 40℃

[0118] 3-5. Cross-sectional area ratio The cross-sectional area ratio of each component in the cross section was evaluated by scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDX).

[0119] (Preparation of sample pieces) The sample was cut into a 1 mm × 5 mm strip, and metallic Os was vapor-deposited to ensure electrical conductivity. After that, the sample was cross-sectioned by ion milling (accelerating voltage 4 kV).

[0120] (SEM-EDX measurement) The field of view of the obtained sample piece was set so that it was within a range of 100 to 150 μm in the direction perpendicular to the membrane thickness direction and so that the center of the membrane thickness of the hydrogen separation membrane was included in the membrane thickness direction. Next, when the above field of view was analyzed using a scanning electron microscope-energy dispersive X-ray spectroscopy, the regions corresponding to the hydrogen storage alloy, binder resin, and matrix resin were identified, and the area ratio of each region to the total area of ​​the hydrogen separation membrane in the above field of view was measured as the area ratio [%].

[0121] The areas were identified as follows: For samples 1 to 4 and 7 to 10, the areas where Ni was detected were determined to be hydrogen storage alloys, the areas where fluorine was detected were determined to be fluororesin, and the areas where only carbon was detected were determined to be areas where epoxy resin was present. For sample 5, the area where Ni was detected was the hydrogen storage alloy, the area where nitrogen was detected was the thermosetting resin (because polyamine resin was used as the curing agent), and the area where no other nitrogen was detected and only carbon was detected was the area where SBR was present. For sample 6, the areas where Ni was detected were identified as hydrogen storage alloy, and the boundaries and areas of PEO and epoxy resin were identified by the shading due to the difference in carbon and oxygen concentrations.

[0122] This measurement was carried out at any five locations in the visual field that did not overlap each other, and the average value was calculated.

[0123] 3-6. Weight reduction rate The weight loss rate of the hydrogen separation membrane was measured by the following procedure. A 10 mg sample of hydrogen separation membrane was weighed out using a precision balance (e.g., XS105 manufactured by Mettler Toledo) and used as a sample piece. The sample piece was placed on a Pt pan and heated from room temperature to 600°C using a differential thermal and thermogravimetric simultaneous analyzer DTG-60H (manufactured by Shimadzu Corporation) under conditions of a nitrogen gas flow rate of 200 mL / min and a heating rate of 20 kJ / min. Alumina was used as a standard material. The weight loss rate was calculated using the weight before the temperature increase, W0, and the weight after the temperature increase, W1, as follows: weight loss rate [%] = (W0 - W1) x 100 / W0.

[0124] 3-7. Gas permeability and selectivity Gas permeability (mol / m 2 The pressure (s·Pa) was measured by a differential pressure method using an apparatus described in JIS K 7126-1:2006. The apparatuses used were GTR-21A-A, GTR-21A-B, and GTR-30XA manufactured by GTR Tech Co., Ltd. The measurement temperature was 80°C, and the supply pressure was 0.1 MPa (differential pressure 0.1 MPa). The selectivity was calculated by applying the hydrogen permeability and the carbon dioxide permeability to the following formula (1). Equation (1): Selectivity = hydrogen permeability [mol / m 2 ·s·Pa] / carbon dioxide permeability [mol / m 2 ·s·Pa]

[0125] The compositions of Samples 1 to 11 are shown in Table 1, and the evaluation results are shown in Table 2. The charged compositions in Table 1 show the ratio of the mass content of each component to the total mass of the hydrogen storage alloy and the binder resin for Samples 1 to 6, and the ratio of the mass content of each component to the total mass of the hydrogen storage alloy and the matrix resin for Samples 7 to 11. The film composition calculated from the cross-sectional image of the film in Table 1 indicates the mass ratio of each component to the entire film, calculated from the area ratio and density of each component in the SEM-EDX analysis image (cross-sectional image). 3A to 3C are monochrome processed SEM-EDX analysis images of the sample cross sections. Specifically, the SEM-EDX analysis images have been color-filtered to remove the color from the areas where only carbon is detected (areas where the matrix resin is present). Of these, Fig. 3A is a processed image of Sample 3, Fig. 3B is that of Sample 9, and Fig. 3C is that of Sample 10.

[0126] [Table 1]

[0127] [Table 2]

[0128] As shown in Table 2, samples 7 to 10, obtained by mixing matrix resin and LaNi4Al and then coating, showed a slight improvement in selectivity compared to resin films that did not contain LaNi4Al, but it was still insufficient. This is thought to be because, as shown in Figure 3B, LaNi4Al was dispersed in the film, and almost no paths for hydrogen permeation were formed. Also, as shown in Figure 3B, it can be seen that air bubbles are easily mixed in when only matrix resin and LaNi4Al are used. Furthermore, increasing the LaNi4Al content slightly increases the hydrogen permeability, but the selectivity decreases (comparison of Samples 7-8 with Sample 9). This is thought to be due to the formation of many pores that connect one side of the membrane to the other. Furthermore, Sample 14, in which epoxy resin was further applied to the surface of Sample 9 to seal the pores, showed almost no change in selectivity compared to before application (see Figure 3C).

[0129] In contrast, in samples 1 to 6, in which a porous film containing a binder resin and LaNi4Al was formed and then the pores were filled with a matrix resin, the hydrogen permeability was 7.5 × 10 -11 mol / m 2The pressure was high, at over 100 s Pa, and the selectivity was also high, at over 50. This is thought to be because, as shown in Figure 3A, LaNi4Al was well bound by the binder resin, forming paths connecting the LaNi4Al. [Industrial Applicability]

[0130] According to the present invention, it is possible to provide a hydrogen separation membrane that achieves both high hydrogen permeability and high selectivity. [Explanation of symbols]

[0131] 10 Hydrogen separation membrane 10A porous membrane 11 Resin 11A Matrix Resin 11B Binder resin 12 Hydrogen storage alloy 13 void

Claims

1. A matrix resin; a hydrogen storage alloy dispersed in the matrix resin; and a binder resin present between the hydrogen storage alloy. Hydrogen separation membrane.

2. The matrix resin includes a cured product of a thermosetting resin composition containing a thermosetting resin. The hydrogen separation membrane according to claim 1 .

3. The matrix resin has a glass transition temperature of 80°C or higher. The hydrogen separation membrane according to claim 2 .

4. The matrix resin has a carbon dioxide permeability coefficient of 1.5×10 measured by a differential pressure method at a measurement temperature of 80° C. and a supply pressure of 1 atmosphere in accordance with JIS K 7126-1:2006. －１７ mol m / (m ２ s Pa) or less, The hydrogen separation membrane according to claim 1 .

5. The hydrogen separation membrane contains 55 mass% or more of the hydrogen storage alloy relative to the total mass of the hydrogen separation membrane. The hydrogen separation membrane according to claim 1 .

6. The hydrogen separation membrane has a weight loss rate of 30% by mass or less when heated to 600°C in an inert gas atmosphere and pyrolyzed. The hydrogen separation membrane according to claim 1 .

7. It is a single layer, The hydrogen separation membrane according to claim 1 .

8. the binder resin contains at least one resin selected from the group consisting of a fluorine-based resin, a diene-based rubber, polyethylene oxide (PEO), a polyolefin-based resin, a urethane resin, a phenolic resin, a polyether, a polyamide, a polyester, a vinyl resin, and an acrylic acid-based copolymer; The hydrogen separation membrane according to claim 1 .

9. The binder resin includes a fluorine-based resin. The hydrogen separation membrane according to claim 1 .

10. The film thickness is 120 μm or less. The hydrogen separation membrane according to claim 1 .

11. A step of preparing a porous film containing a hydrogen storage alloy and a binder resin that adsorbs to the hydrogen storage alloy; and filling voids in the porous membrane with a matrix resin. A method for manufacturing hydrogen separation membranes.

12. A step of supplying a mixed gas containing hydrogen and a gas other than hydrogen to a space in contact with one surface of the hydrogen separation membrane according to any one of claims 1 to 10; and recovering a hydrogen-containing gas from a space in contact with the other surface of the hydrogen separation membrane. A method for producing hydrogen gas.

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