JP2021094495A - Separation membrane sheet, separation membrane element, separation module, and separation device - Google Patents

Abstract

To provide a separation membrane sheet, a separation membrane element, a separation membrane module, and a separation device which can suppress lowering of separation efficiency.SOLUTION: A separation membrane sheet that selectively permeates a specific gas component has a first porous layer, a separation function layer laminated on the first porous layer, and a second porous layer laminated on a side opposite to the separation function layer of the first porous layer. The separation function layer is a nonporous resin composition layer, and the first porous layer and the second porous layer are mutually different porous layers. An average porous diameter of the first porous layer is 0.005 μm or more and 1 μm or less, and a thickness of the first porous layer is 5 μm or more and 150 μm or less. A basis weight deviation of the second porous layer is 0.6 g/m2 or less.SELECTED DRAWING: Figure 1

Description

The present invention relates to a separation membrane sheet, a separation membrane element, a separation membrane module, and a separation device.

Polymer membranes using polymeric compounds are known to be used for the selective separation of specific components contained in fluids such as liquids, gases, solids and mixtures containing at least two of them. For example, Patent Document 1 describes a separation membrane in which a separation layer made of resin is provided on a porous layer made of resin, and Patent Document 2 describes a separation membrane made of resin on a non-woven fabric. A separation membrane provided with a separation layer is described.

Japanese Unexamined Patent Publication No. 2013-166131 Japanese Unexamined Patent Publication No. 2016-101558

In plants that produce hydrogen, urea, etc., for which separation membranes are expected to be applied, high-pressure gas may be supplied to the separation membranes. It has been found that when such a high-pressure gas is supplied to the separation membrane to perform gas separation, the separation efficiency is lowered.

An object of the present invention is to provide a separation membrane sheet, a separation membrane element, a separation membrane module, and a separation device capable of suppressing a decrease in separation efficiency.

The present invention provides the following separation membrane sheet, separation membrane element, separation membrane module, and separation device.
[1] A separation membrane sheet that selectively permeates a specific gas component.
It has a first porous layer, a separation functional layer laminated on the first porous layer, and a second porous layer laminated on the side opposite to the separation functional layer of the first porous layer.
The separation functional layer is a non-porous resin composition layer, and is
The first porous layer and the second porous layer are different porous layers from each other.
The average pore size of the first porous layer is 0.005 μm or more and 1 μm or less.
The thickness of the first porous layer is 5 μm or more and 150 μm or less.
A separation membrane sheet having a basis weight deviation of the second porous layer of 0.6 g / m ^{2 or less.}
[2] The separation membrane sheet according to [1], wherein the thickness of the first porous layer is smaller than the thickness of the second porous layer.
[3] The separation membrane sheet according to [1] or [2], wherein the air permeability of the first porous layer is smaller than the air permeability of the second porous layer.
[4] The separation membrane sheet according to any one of [1] to [3], wherein the resin composition layer is in the form of a gel.
[5] The separation functional layer contains a hydrophilic resin and contains a hydrophilic resin.
The separation membrane sheet according to any one of [1] to [4], wherein the first porous layer is hydrophobic.
[6] The separation membrane sheet according to any one of [1] to [5], wherein the first porous layer is a porous membrane.
[7] The separation membrane sheet according to any one of [1] to [6], wherein the second porous layer is a non-woven fabric.
[8] The separation membrane sheet according to any one of [1] to [7], wherein the separation functional layer contains a carrier that reversibly reacts with the specific gas component.
[9] The separation membrane sheet according to any one of [1] to [8], wherein the specific gas component is an acid gas.
[10] A separation membrane element including the separation membrane sheet according to any one of [1] to [9].
A supply-side flow path member that forms a flow path through which the raw material gas containing the specific gas component flows, and
A permeation-side flow path member that forms a flow path through which a permeated gas containing the specific gas component that has permeated the separation membrane sheet flows.
The supply-side flow path member is arranged on the side of the separation membrane sheet opposite to the second porous layer.
The permeation side flow path member is a separation membrane element arranged on the second porous layer side of the separation membrane sheet.
[11] The separation membrane element according to [10] and
A raw material gas supply port communicating with a flow path formed by the supply side flow path member of the separation membrane element,
Non-permeated gas outlet and
A separation membrane module including a permeation gas discharge port communicating with a flow path formed by the permeation side flow path member of the separation membrane element.
[12] A separation device including at least one separation membrane module according to [11].

According to the present invention, it is possible to provide a separation membrane sheet, a separation membrane element, a separation membrane module, and a separation device capable of suppressing a decrease in separation efficiency.

(A) and (b) are schematic cross-sectional views schematically showing the separation membrane sheet of the present invention. It is schematic cross-sectional view which shows typically an example of the laminated body including the separation membrane sheet provided in the separation membrane element of this invention. (A) and (b) are schematic perspective views provided with a partially developed portion showing another example of the separation membrane element of the present invention. It is the schematic schematic diagram explaining the test apparatus of the airtightness test performed in an Example.

(Separation membrane sheet)
1A and 1B are schematic cross-sectional views schematically showing the separation membrane sheet of the present embodiment. The separation membrane sheet 10 shown in FIG. 1A is a separation membrane sheet 10 that selectively permeates a specific gas component, and has a separation function of being laminated on the first porous layer 11 and the first porous layer 11. It has a layer 15 and a second porous layer 12 laminated on the side opposite to the separation functional layer 15 of the first porous layer 11. The separation functional layer 15 is a non-porous resin composition layer, and the first porous layer 11 and the second porous layer 12 are different porous layers from each other. The average pore size of the first porous layer 11 is 0.005 μm or more and 1 μm or less, and the thickness of the first porous layer 11 is 5 μm or more and 150 μm or less. The basis weight deviation of the second porous layer 12 is 0.6 g / m ² or less.

The fact that the first porous layer 11 and the second porous layer 12 are different from each other means that the first porous layer 11 and the second porous layer 12 are not completely the same, for example, the first porous layer. Types and forms of materials constituting 11 and the second porous layer 12 (porous film, non-woven fabric, woven fabric, foam, etc.), thickness, density, average pore size, porosity of the first porous layer 11 and the second porous layer 12. It means that at least one of the physical properties such as is different.

It is preferable that the first porous layer 11 and the second porous layer 12 are different in at least one of the thickness and the air permeability. When the thickness of the first porous layer 11 and the thickness of the second porous layer 12 are different from each other, the thickness of the first porous layer 11 is preferably smaller than the thickness of the second porous layer 12. When the air permeability of the first porous layer 11 and the air permeability of the second porous layer 12 are different from each other, the air permeability of the first porous layer 11 is preferably smaller than the air permeability of the second porous layer 12.

It is preferable that the first porous layer 11 is a porous membrane and the second porous layer 12 is a non-woven fabric.

The second porous layer 12 is preferably arranged on the transmission side flow path member side in the separation membrane element described later.

As shown in FIG. 1B, the separation membrane sheet 10 may have a third porous layer on the opposite side of the separation functional layer 15 from the first porous layer 11, and the separation membrane sheet 10 may have a third porous layer of the third porous layer 13. The fourth porous layer 14 may be provided on the side opposite to the separation function layer 15.

The specific gas component that the separation membrane sheet 10 selectively permeates is preferably an acid gas. The acidic gases carbon dioxide _(CO 2), hydrogen sulfide _(H 2 S), carbonyl sulfide, sulfur oxides _(SO x), nitrogen oxides _(NO x), include hydrogen halides such as hydrogen chloride, and .. The specific gas component is preferably carbon dioxide.

(Separation function layer)
The separation function layer 15 has gas selective permeability mainly for selectively permeating a specific gas component. The separation functional layer 15 is a non-porous resin composition layer formed by using the resin composition, and is preferably a gel-like resin composition layer. In the present specification, the non-porous resin composition layer is not a porous layer (molecular sieving membrane) that selectively permeates by utilizing the difference in the size and shape of the molecule, but the difference in the solubility and diffusivity of the molecule. Refers to a layer (dissolved-diffusing membrane) that is selectively permeated using. Examples of the non-porous resin composition layer include a promoted transport membrane containing a substance that promotes the solubility and / and diffusivity of gas molecules.

The resin composition layer preferably contains at least a hydrophilic resin and a carrier that reversibly reacts with a specific gas component, and may contain an additive other than the hydrophilic resin and the carrier, if necessary. ..

The hydrophilic resin is a resin having a hydrophilic group such as a hydroxyl group or an ion exchange group, and includes a crosslinked hydrophilic resin that exhibits high water retention by having a network structure in which the molecular chains of the hydrophilic resin are crosslinked. Is more preferable.

The polymer forming the hydrophilic resin preferably has, for example, an acrylic acid alkyl ester, a methacrylic acid alkyl ester, a vinyl ester of a fatty acid, or a structural unit derived from a derivative thereof. Examples of the polymer exhibiting such hydrophilicity include a polymer obtained by polymerizing a monomer such as acrylic acid, itaconic acid, crotonic acid, methacrylic acid, and vinyl acetate, and specifically, an ion exchange group. Polyacrylic acid-based resin having a carboxyl group, polyitaconic acid-based resin, polycrotonic acid-based resin, polymethacrylic acid-based resin, etc., polyvinyl alcohol-based resin having a hydroxyl group, etc. Examples thereof include a polymerization system resin, an acrylic acid-methacrylic acid copolymer system resin, an acrylic acid-methyl methacrylate copolymer system resin, and a methacrylic acid-methyl methacrylate copolymer system resin. Among these, polyacrylic acid-based resin which is a polymer of acrylic acid, polymethacrylic acid-based resin which is a polymer of methacrylic acid, polyvinyl alcohol-based resin obtained by hydrolyzing a polymer of vinyl acetate, methyl acrylate and vinyl acetate. Acrylate-vinyl alcohol copolymer resin obtained by saponifying the copolymer of the above, acrylic acid-methacrylic acid copolymer resin which is a copolymer of acrylic acid and methacrylic acid is more preferable, and polyacrylic acid and acrylate are more preferable. -Vinyl alcohol copolymer resin is more preferred.

The crosslinked hydrophilic resin may be prepared by reacting a polymer exhibiting hydrophilicity with a crosslinking agent, or a monomer used as a raw material of the polymer exhibiting hydrophilicity and a crosslinkable monomer are copolymerized. May be prepared. The cross-linking agent or cross-linking monomer is not particularly limited, and conventionally known cross-linking agents or cross-linking monomers can be used.

Examples of the cross-linking agent include epoxy cross-linking agents, polyhydric glycidyl ethers, polyhydric alcohols, polyhydric isocyanates, polyhydric aziridines, haloepoxy compounds, polyvalent aldehydes, polyvalent amines, organic metal-based cross-linking agents, metal-based cross-linking agents and the like. Examples of the conventionally known cross-linking agent. Examples of the crosslinkable monomer include conventionally known crosslinkable monomers such as divinylbenzene, N, N'-methylenebisacrylamide, trimethylolpropane triallyl ether, and pentaerythritol tetraallyl ether. Examples of the cross-linking method include methods such as thermal cross-linking, ultraviolet cross-linking, electron beam cross-linking, radiation cross-linking, and photo-crosslinking, and methods described in JP-A-2003-26809 and JP-A-7-88171. Conventionally known methods can be used.

The carrier that reversibly reacts with the specific gas component exists in the resin composition layer constituting the separation functional layer 15, and by reversibly reacting with the specific gas component dissolved in the resin composition layer, the carrier reversibly reacts with the specific gas component. Selectively permeates a specific gas component. The carrier contained in the separation function layer 15 may be one type or two or more types.

Specific examples of the carrier used when the specific gas component is an acid gas include an alkali metal carbonate, an alkali metal bicarbonate, and an alkanolamine (for example, No. 7-102310) when the acid gas is carbon dioxide. (Described in Japanese Patent No. 2086581), etc.) and alkali metal hydroxides (for example, described in the pamphlet of International Publication No. 2016/024523), when the acid gas is a sulfur oxide, a sulfur-containing compound or When the acid gas is a nitrogen oxide, the alkali metal citrate and the transition metal complex (for example, described in Japanese Patent No. 2879057) and the like are alkali metal nitrite and the transition metal complex (for example, Patent No. 2879057). (Described in the Gazette, etc.), etc., respectively.

The thickness of the separation functional layer 15 is preferably 1000 μm or less, more preferably 500 μm or less, further preferably 100 μm or less, and usually 5 μm or more. The thickness can be determined by observing the cross section of the separation functional layer 15 using an optical microscope or an electron microscope.

In addition to the hydrophilic resin and the carrier, the separation functional layer 15 contains, for example, a hydration reaction catalyst for improving the reaction rate between a specific gas component and the carrier, a surfactant, and the like as additives. May be good.

Examples of the hydration reaction catalyst when the specific gas component is an acid gas include an oxo acid compound. The oxoacid compound is preferably an oxoacid compound of at least one element selected from the group consisting of Group 14 elements, Group 15 elements, and Group 16 elements, and is preferably a tellurous acid compound, a selenous acid compound, and a sub. It is more preferable that the compound is at least one selected from the group consisting of the tellurous acid compound and the orthosilicic acid compound. The separation functional layer 15 may contain one or more oxoacid compounds.

The surfactant is not particularly limited, but for example, polyoxyethylene polyoxypropylene glycols, polyoxyethylene alkyl phenyl ethers, polyoxyethylene alkyl ethers, fluorine-based surfactants, silicone-based surfactants and the like. Conventionally known surfactants can be used. One type of surfactant may be used alone, or two or more types may be used in combination.

(First porous layer)
The first porous layer 11 can be used as a support layer for supporting the separation function layer 15. The first porous layer 11 may be a layer to which a coating liquid containing a resin composition is applied in order to form the separation functional layer 15. In the separation membrane sheet 10, the first porous layer 11 is contained in the raw material gas supplied to the separation functional layer 15, particularly the raw material gas, and does not serve as a diffusion resistance of a specific gas component that selectively permeates the separation functional layer 15. As described above, it has high porosity with high gas permeability.

The first porous layer 11 may have a single-layer structure or may have a multi-layer structure. When the first porous layer 11 has a multi-layer structure, the layers may be the same as each other or different from each other.

The average pore size of the first porous layer 11 is 0.005 μm or more, preferably 0.01 μm or more, more preferably 0.05 μm or more, and 1 μm or less, 0.7 μm or less. It is preferably 0.5 μm or less, and more preferably 0.5 μm or less. The average pore size of the first porous layer 11 can be measured by the method described in Examples described later.

The thickness of the first porous layer 11 is 5 μm or more, preferably 10 μm or more, more preferably 15 μm or more, further preferably 30 μm or more, and 150 μm or less, 120 μm or less. It is preferably 100 μm or less, more preferably 80 μm or less. The thickness of the first porous layer 11 is preferably smaller than the thickness of the second porous layer 12, which will be described later. The thickness can be measured by the method described in Examples described later.

When the average pore diameter and thickness of the first porous layer 11 are within the above ranges, it does not become a diffusion resistance of a specific gas component that selectively permeates the separation function layer 15, and serves as a support layer for the separation function layer 15. It can be preferably used. Further, when the resin composition is applied on the first porous layer 11 in order to form the resin composition layer constituting the separation functional layer 15, stable film forming property can be easily obtained.

The porosity of the first porous layer 11 is preferably 5% or more, preferably 10%, from the viewpoint of being suitably used as a support layer for the separation functional layer while suppressing the diffusion resistance of a specific gas component. It may be more than, 20% or more, 30% or more, preferably 99% or less, 95% or less, 90% or less. You may.

The porosity can be calculated by the following procedure. First, the area, thickness, and weight [g] of a sample obtained by cutting the first porous layer 11 into a size of 250 mm × 200 mm are measured. The porosity is calculated according to the following formula, where the true density of the material constituting the first porous layer 11 is ρ [g / cm ^3].
Porosity [%] = [(Sample area x Sample thickness x ρ) -Sample weight] / (Sample area x Sample thickness x ρ)

The true density of the first porous layer 11 is determined by measuring the volume and weight of the melt-solidified sample obtained by heating the cut-out sample to a melting point or higher, melting it to make it non-porous, and then cooling and solidifying it. Can be decided. When the first porous layer 11 has a multi-layer structure, the true density of the material constituting the first porous layer 11 can be determined based on the ratio (thickness ratio) of each layer contained in the cut-out sample.

The air permeability of the first porous layer 11 has a Garley value of 30 seconds or more, which indicates the air permeability, from the viewpoint that it is suitably used as a support layer for the separation function layer while suppressing the diffusion resistance of a specific gas component. It is preferably 60 seconds or more, 90 seconds or more, 2000 seconds or less, 1500 seconds or less, 1000 seconds or less. It may be 500 seconds or less. The air permeability of the first porous layer 11 is preferably smaller than the air permeability of the second porous layer 12, which will be described later. The Garley value indicating the aeration resistance can be determined by measuring in accordance with JIS L 1096, and more specifically, it can be determined by the method described in Examples described later.

The Young's modulus of the first porous layer 11 is preferably 20 GPa or more, preferably 100 GPa or more, from the viewpoint of being suitably used as a support layer of the separation functional layer while suppressing the diffusion resistance of a specific gas component. It may be 200 GPa or more, preferably 1200 GPa or less, 1000 GPa or less, 800 GPa or less, or 600 GPa or less.

Young's modulus can be measured by the following procedure. A small piece is cut out from the first porous layer 11 into a dumbbell shape specified by JIS K6251-3. Under the conditions of a temperature of 23 ° C. and a relative humidity of 50% RH, a small piece of film is attached to the autograph device and pulled at a constant speed of 50 mm / min. Young's modulus is calculated from the initial stress and strain in this measurement. The measurement is performed three times, and the average value is defined as the Young's modulus of the first porous layer 11.

The first porous layer 11 is preferably hydrophobic, and the contact angle of water at a temperature of 25 ° C. may be 90 degrees or more, 95 degrees or more, or 100 degrees or more. .. The contact angle of water can be measured with a contact angle meter (for example, manufactured by Kyowa Interface Science Co., Ltd .; trade name: "DropMaster500").

The first porous layer 11 is preferably formed of a resin material or an inorganic material. Examples of the resin material constituting the first porous layer 11 include polyolefin resins such as polyethylene (PE) and polypropylene (PP); polytetrafluoroethylene (PTFE), polyvinyl fluoride (PVF), and vinylidene polyvinylfluoride (PVDF). ) And other fluorine-containing resins; polyethylene terephthalate (PET), polyethylene naphthalate and other polyester resins; polystyrene (PS), polyethersulfone (PES), polyphenylene sulfide (PPS), polysulfones (PSF), polyacrylonitrile (PAN), Polyphenylene oxide (PPO), polyamide (PA), polyimide (PI), polyetherimide (PEI), polyetheretherketone (PEEK), high molecular weight polyester, heat-resistant polyamide, aramid, polycarbonate, among these resin materials Examples include a mixture of two or more types. Among these, a polyolefin resin or a fluorine-containing resin is preferable from the viewpoint of water repellency and heat resistance. Examples of the inorganic material constituting the first porous layer 11 include metals, glass, ceramics and the like. The first porous layer 11 may contain both a resin material and an inorganic material.

The first porous layer 11 is not particularly limited as long as it is a porous body, and may be in the form of, for example, a porous membrane, a non-woven fabric, a woven fabric, a foam, a net, or the like. The first porous layer 11 is preferably a porous film from the viewpoint that it is suitably used as a support layer for the separation functional layer while suppressing the diffusion resistance of a specific gas component. The porous film refers to a porous resin film. Examples of the porous film include a porous film obtained by a stretching method or a phase separation method.

(Second porous layer)
The second porous layer 12 is laminated on the side opposite to the separation functional layer 15 of the first porous layer 11, and can be used as a reinforcing layer for reinforcing the function of the first porous layer 11 as a support layer. By providing the second porous layer 12, it is possible to additionally impart strength that can withstand the pressure load applied to the separation membrane sheet 10 when a specific gas component in the raw material gas is selectively permeated. Further, when the resin composition is applied on the first porous layer 11 in order to form the resin composition layer constituting the separation functional layer 15, the strength capable of withstanding the tension load applied to the first porous layer 11 is increased. It can be additionally given.

The second porous layer 12 may have a single-layer structure or may have a multi-layer structure. When the second porous layer 12 has a multi-layer structure, the layers may be the same as each other or different from each other.

The texture deviation of the second porous layer 12 is 0.6 g / m ² or less, preferably 0.55 g / m ² or less, more preferably 0.5 g / m ² or less, and usually 0. It is 0.01 g / m ² or more. The basis weight deviation of the second porous layer 12 can be measured by the method described in Examples described later.

When the basis weight deviation of the second porous layer 12 is within the above range, unevenness of the basis weight of the second porous layer 12 can be suppressed. When the unevenness of the basis weight of the second porous layer 12 is suppressed, uniform strength can be imparted to the entire separation membrane sheet 10. As a result, when pressure is applied to the separation membrane sheet 10 by supplying the raw material gas, the separation membrane sheet is formed in a region having a relatively small basis weight deviation of the second porous layer 12 contained in the separation membrane sheet 10. It is possible to prevent damage such as breakage from occurring in 10 (particularly, the separation functional layer 15). As a result, it is possible to suppress the outflow of the raw material gas without being separated in the damaged region, so that it is possible to suppress a decrease in the separation efficiency. On the other hand, when the basis weight unevenness in the second porous layer 12 is large, when pressure is applied to the separation membrane sheet 10 during gas separation, a region having a relatively large basis weight deviation in the second porous layer 12 and the like In the above, the separation membrane sheet 10 (particularly, the separation functional layer 15) is liable to be damaged such as broken. In the region where such damage occurs, the raw material gas flows out without being separated, so that the separation efficiency tends to decrease.

^{The basis weight of the second porous layer 12 is preferably 10 g / m 2} or more, and more preferably 15 g / m ² or more, from the viewpoint of imparting strength that can withstand the pressure and tension applied to the separation membrane sheet 10. , 20 g / m ² or more, usually 200 g / m ² or less, and 150 g / m ² or less. The basis weight can be measured by the method described in Examples described later.

The thickness of the second porous layer 12 is preferably 10 μm or more, more preferably 50 μm or more, and more preferably 100 μm or more, from the viewpoint of imparting strength that can withstand the pressure and tension applied to the separation membrane sheet 10. It may be 700 μm or less, preferably 600 μm or less, 500 μm or less, or 400 μm or less. The thickness can be measured in the same manner as the method for measuring the thickness of the first porous layer 11 described in Examples described later.

The porosity of the second porous layer 12 is preferably 5% or more, preferably 10% or more, and 20% or more, from the viewpoint of imparting strength that can withstand the pressure and tension applied to the separation membrane sheet 10. It may be 30% or more, preferably 99% or less, 95% or less, or 90% or less. The porosity can be calculated by the method described above.

The air permeability of the second porous layer 12 preferably has a Garley value of 0.01 seconds or more, may be 0.05 seconds or more, and is usually 30 seconds or less, 20 seconds or less. It may be 10 seconds or less. The Garley value indicating the aeration resistance can be measured and determined in accordance with JIS L 1096, and more specifically, it can be determined by the method described in Examples described later.

The Young's modulus of the second porous layer 12 is preferably 20 GPa or more, preferably 50 GPa or more, or 100 GPa or more, from the viewpoint of imparting strength that can withstand the pressure and tension applied to the separation membrane sheet 10. It may be 400 GPa or less, preferably 300 GPa or less, or 200 GPa or less. Young's modulus can be calculated by the method described above.

The second porous layer 12 is preferably formed of a resin material or an inorganic material. Examples of the resin material or the inorganic material constituting the second porous layer 12 include a resin material or an inorganic material for forming the first porous layer 11. The resin material for forming the second porous layer 12 is preferably a polyolefin resin or polyphenylene sulfide.

The second porous layer 12 is not particularly limited as long as it is a porous body, and may be in the form of, for example, a porous membrane, a non-woven fabric, a woven fabric, a foam, a net, or the like. The second porous layer 12 is preferably a non-woven fabric from the viewpoint of imparting strength that can withstand the pressure and tension applied to the separation membrane sheet 10. Examples of the non-woven fabric include spunbond non-woven fabric, melt blow non-woven fabric, air-laid non-woven fabric, spunlace non-woven fabric, and card non-woven fabric.

When the second porous layer 12 is a non-woven fabric, the average fiber diameter of the fibers constituting the non-woven fabric is usually 1 μm or more, 5 μm or more, 10 μm or more, and usually 80 μm or less. Yes, it may be 60 μm or less, 50 μm or less, or 30 μm or less. The average fiber diameter can be an average value of the fiber diameters measured for 50 arbitrarily selected fibers by photographing the surface of the second porous layer 12 using an optical microscope or an electron microscope.

The second porous layer 12 is preferably fixed to the first porous layer 11. As the fixing method, a conventionally known method can be used, and examples thereof include a method of bonding via an adhesive or an adhesive, a heat fusion method, and the like. In the case of bonding via an adhesive or an adhesive, after applying the adhesive or the adhesive to at least one of the first porous layer 11 and the second porous layer 12, the first porous layer 11 and the second porous layer 11 and the second porous layer 12 are bonded. The layer 12 may be bonded. The amount of the adhesive or the pressure-sensitive adhesive interposed between the first porous layer 11 and the second porous layer 12 can be, for example, 1 g / m ² or more and 1000 g / m ² or less, and 5 g / m ² or more and 200 g / m. It ^{may be m 2} or less. Examples of the method of fixing by the heat fusion method include a method in which the first porous layer 11 and the second porous layer 12 are laminated and then heat or vibration is applied from the outside to melt and fuse the joint surfaces. Be done.

When the space between the first porous layer 11 and the second porous layer 12 or between the second porous layer 12 and another layer is fixed with an adhesive or an adhesive, these are taken from the separation membrane sheet 10. When taking out the layer, first, the separation membrane sheet 10 is washed with water and dried to remove the separation function layer 15. Next, the adhesive or the pressure-sensitive adhesive may be dissolved and removed using a solvent or the like, the first porous layer 11 and the second porous layer 12 may be taken out, and the above-mentioned various physical properties may be measured.

When the space between the first porous layer 11 and the second porous layer 12 and between the second porous layer 12 and another layer are fixed by heat fusion, the basis weight of the second porous layer 12 is as follows. It can be measured by the procedure of. First, the separation membrane sheet 10 is washed with water and dried to remove the separation functional layer 15. Next, a first sample cut out to a size of 50 mm × 50 mm was prepared so as to include the entire layer fixed to the second porous layer 12 by heat fusion, and a second sample was observed from the cross section of the first sample. The thickness of the porous layer 12 is measured, and the average value thereof is calculated. Subsequently, in the first sample, the second sample is set so as to include only the second porous layer 12 from 10 positions arbitrarily selected from a plurality of circular regions having a diameter of 12 mm that do not overlap each other. (10 in total) are acquired, the density of each second sample is measured, and the average value thereof is calculated. Using these average values, the basis weight of the second porous layer 12 is determined based on the following equation.
Metsuke of the second porous layer = (average value of the density of the second sample) × (average value of the thickness of the second porous layer in the first sample)

When the first porous layer 11 and the second porous layer 12 and the second porous layer 12 and another layer are fixed by heat fusion, the basis weight deviation of the second porous layer 12 is Except for using the basis weight value calculated above, the measurement can be performed according to the method described in Examples described later.

(Third porous layer)
The third porous layer 13 is laminated on the opposite side of the separation functional layer 15 from the first porous layer 11, and can be used as a protective layer for protecting the separation functional layer 15. The third porous layer 13 may have a single-layer structure or may have a multi-layer structure. When the third porous layer 13 has a multi-layer structure, the layers may be the same as each other or different from each other. As the third porous layer 13, for example, the same one as the first porous layer 11 can be used.

(4th porous layer)
The fourth porous layer 14 is laminated on the side opposite to the separation function layer 15 of the third porous layer 13, and can be used as a reinforcing layer for reinforcing the function of the third porous layer 13 as a protective layer. The fourth porous layer 14 may have a single-layer structure or may have a multi-layer structure. When the fourth porous layer 14 has a multi-layer structure, the layers may be the same as each other or different from each other. As the fourth porous layer 14, for example, the same one as the second porous layer 12 can be used. The fourth porous layer 14 may or may not be fixed to the third porous layer 13. When the fourth porous layer 14 and the third porous layer 13 are fixed, a conventionally known fixing method can be applied. For example, the above-mentioned fixing method of the first porous layer 11 and the second porous layer 12 can be applied. Can be mentioned.

(Manufacturing method of separation membrane sheet)
The method for producing the separation membrane sheet 10 includes, for example, a step of preparing a coating liquid containing a resin composition for forming the separation functional layer 15 (hereinafter, may be referred to as a “preparation step”) and a first porous layer. The step of applying the coating liquid on the 11 (hereinafter, may be referred to as “coating step”) can be included. In the method for producing the separation membrane sheet 10, prior to the coating step, the second porous layer 12 is laminated on the side of the first porous layer 11 to which the coating liquid is applied in advance, on the side opposite to the side on which the coating liquid is applied. It may have a process. Alternatively, in the method for producing the separation membrane sheet 10, after the separation functional layer 15 is formed on the first porous layer 11, the second porous layer 12 is laminated on the side of the first porous layer 11 opposite to the separation functional layer 15. It may have a step to carry out.

The preparation step is a step of preparing a coating liquid to be applied on the first porous layer 11. In the preparation step, for example, the coating liquid can be prepared by mixing the resin composition for forming the separation functional layer 15 and the medium. The resin composition can include the above-mentioned resin, a carrier that reversibly reacts with a specific gas component, a hydration reaction catalyst, a surfactant, and the like. Examples of the medium include a protonic polar solvent such as water, an alcohol such as methanol, ethanol, 1-propanol and 2-propanol; a non-polar solvent such as toluene, xylene and hexane; and a ketone such as acetone, methyl ethyl ketone and methyl isobutyl ketone. , N-methylpyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide and other aprotic polar solvents; and the like. One type of medium may be used alone, or two or more types may be used in combination as long as they are compatible with each other. Among these, a medium containing at least one selected from the group consisting of alcohols such as water, methanol, ethanol, 1-propanol and 2-propanol is preferable, and a medium containing water is more preferable.

The preparatory step may include a defoaming step for removing air bubbles contained in the prepared coating liquid. Examples of the defoaming step include a method of applying shear by stirring or filtering the coating liquid, a method of vacuum degassing or degassing the coating liquid under reduced pressure, a method of heating the coating liquid to degas, and the like. Can be done.

The coating step is a step of applying the coating liquid prepared in the preparation step onto the first porous layer 11. The coating process is by slot die coating, spin coating method, bar coating, die coating, blade coating, air knife coating, gravure coating, roll coating coating, spray coating, dip coating, comma roll method, kiss coating method, screen printing, inkjet printing, etc. It can be carried out.

The coating step preferably includes a step of removing the medium from the film of the coating liquid formed by applying the coating liquid on the first porous layer 11. Examples of the step of removing the medium include a method of evaporating and removing the medium from the film of the coating liquid by heating or the like.

In the method for producing the separation membrane sheet 10, when the separation membrane sheet 10 has the third porous layer 13, the third porous layer 13 is laminated on the side opposite to the first porous layer 11 of the membrane formed by the coating liquid. It may have a process. After laminating the third porous layer 13, a step of further removing the medium in the film of the coating liquid may be performed. When the separation membrane sheet 10 further has the fourth porous layer 14, the method for producing the separation membrane sheet 10 is the side of the third porous layer 13 facing the film of the coating liquid prior to the step of laminating the third porous layer 13. There may be a step of laminating the fourth porous layer 14 on the opposite side to the above. Alternatively, in the method for producing the separation membrane sheet 10, the third porous layer 13 is laminated on the separation functional layer 15, and then the fourth porous layer 14 is laminated on the side of the third porous layer 13 opposite to the separation functional layer 15. It may have a process.

(Separation membrane element)
The separation membrane sheet 10 can be used for known separation membrane elements such as spiral type, flat membrane type, hollow fiber type, tube type, pleated type, and plate and frame type.

FIG. 2 is a schematic cross-sectional view schematically showing an example of a laminated body including a separation membrane sheet provided in the separation membrane element of the present embodiment. As shown in FIG. 2, the separation membrane element 20 includes a supply-side flow path member 3 that forms a flow path through which a raw material gas containing a specific gas component flows, and a permeation containing a specific gas component that has permeated the separation membrane sheet 10. Includes a permeation side flow path member 4 that forms a flow path through which gas flows. In the separation membrane element 20, the supply side flow path member 3 is arranged on the side opposite to the second porous layer 12 of the separation membrane sheet 10, and the transmission side flow path member 4 is on the second porous layer 12 side of the separation membrane sheet 10. Be placed. When the separation membrane sheet 10 has the third porous layer 13 and the fourth porous layer 14, the supply-side flow path member 3 is arranged on the third porous layer 13 side or the fourth porous layer 14 side. In the separation membrane element 20 shown in FIG. 2, the supply side flow path member 3 is arranged on the fourth porous layer 14 side of the separation membrane sheet 10.

3A and 3B are schematic perspective views provided with a partially developed portion showing an example of the separation membrane element of the present embodiment. The separation membrane elements shown in FIGS. 3A and 3B are spiral type separation membrane elements 21 and 21a. The spiral type separation membrane elements 21 and 21a are shown in FIGS. 3A and 3B, as shown in FIGS. 3A and 3B.
A supply-side flow path member 3 that forms a flow path through which a raw material gas containing a specific gas component flows, and
A separation membrane sheet 10 that selectively separates and permeates a specific gas component contained in the raw material gas flowing through the supply-side flow path member 3.
A permeation side flow path member 4 that forms a flow path through which a permeated gas containing a specific gas component that has permeated the separation membrane sheet 10 flows, and a permeation side flow path member 4.
A sealing part to prevent mixing of the raw material gas and the permeated gas,
It has a central tube 5 for collecting the permeated gas flowing through the permeation side flow path member 4, and has.
An element laminate in which at least one or more of the supply-side flow path member 3, the separation membrane sheet 10, and the transmission-side flow path member 4 are laminated can be provided with a wound body wound around a central tube 5. .. The winding body may have an arbitrary shape such as a cylindrical shape or a square tubular shape. The central tube 5 has a plurality of holes 50 on the outer peripheral surface thereof that communicate the flow path space of the permeated gas formed by the permeation side flow path member 4 and the hollow space inside the central tube 5.

The spiral type separation membrane element 21a is further provided with a fixing member such as an outer peripheral tape and a telescope prevention plate 55 shown in FIG. 3B in order to prevent the winding body from being unwound or unwound. In addition, an outer wrap (reinforcing layer) may be provided on the outermost periphery of the wound body in order to secure the strength against the load due to the internal pressure and the external pressure applied to the separation membrane element.

The supply-side flow path member 3 and the permeation-side flow path member 4 promote turbulence (surface renewal of the membrane surface) of the permeated gas that has permeated the raw material gas and the separation membrane sheet 10, and the film of the permeated gas in the raw material gas. It is preferable to have a function of increasing the permeation rate and a function of minimizing the pressure loss of the supplied raw material gas and the permeation gas that has permeated the separation membrane sheet 10. The supply-side flow path member 3 and the permeation-side flow path member 4 have a function of causing turbulence in the raw material gas and the permeated gas in addition to a function as a spacer for forming a flow path of the raw material gas and the permeated gas. Therefore, a mesh-like one (net-like, mesh-like, etc.) is preferably used. Since the gas flow path changes depending on the shape of the mesh, the shape of the unit lattice of the mesh is preferably selected from, for example, a square, a rectangle, a rhombus, a parallelogram, and the like, depending on the purpose. The material of the supply side flow path member 3 and the transmission side flow path member 4 is not particularly limited, but a material having heat resistance capable of withstanding the operating temperature conditions of the separation device provided with the separation membrane elements 20, 21 and 21a is preferable. ..

The sealing portion is provided to prevent mixing of the raw material gas and the permeated gas, and can be formed by, for example, the sealing material permeating into the permeation side flow path member 4 and the separation membrane sheet 10 and hardening. .. The sealing portion is usually the center of the end portions located at both ends in the direction parallel to the axis of the central tube 5 of the wound body and the end portions located at both ends in the direction orthogonal to the axis of the central tube 5. It is provided at the end on the side where the distance between the tube 5 and the end is long, and can form a so-called envelope shape. For the sealing portion, a material generally used as an adhesive can be used, and for example, an epoxy resin or the like can be used.

The central tube 5 is a conduit for collecting the permeated gas that has passed through the separation membrane sheet 10 and discharging it from the separation membrane elements 21 and 21a. The central tube 5 is preferably a material having heat resistance that can withstand the operating temperature conditions of the separation device provided with the separation membrane elements 21 and 21a, and mechanical strength that can withstand the winding of the element laminate.

(Separation membrane module)
The separation membrane element can be used in the separation membrane module. The separation membrane module has one or more separation membrane elements. The separation membrane module includes a raw material gas supply port (a portion communicating with the supply side end portion 51 shown in FIG. 3B) and a non-permeated gas that communicate with the flow path formed by the supply side flow path member 3 of the separation membrane element. A permeation gas discharge port (a portion communicating with the discharge side end portion 53 shown in FIG. 3B) and a permeation gas discharge port communicating with a flow path formed by the permeation side flow path member 4 of the separation membrane element (FIG. 3 (b)). ) Is provided with a portion that communicates with the discharge port 52. In the separation membrane module, the raw material gas is supplied to the separation membrane sheet 10 through the raw material gas supply port, and the permeated gas that has passed through the separation membrane sheet 10 is discharged through the permeation gas discharge port and permeates the separation membrane sheet 10. The missing raw material gas is discharged through the non-permeable gas outlet. The raw material gas supply port, the non-permeated gas discharge port, and the permeated gas discharge port may be provided in the main body of the separation membrane element, and may be a container for accommodating the separation membrane element (hereinafter, may be referred to as a “housing”). It may be provided in.

The housing can form a space for enclosing the raw material gas flowing in the separation membrane module, and includes, for example, a tubular member such as stainless steel and a closing member for closing both ends of the tubular member in the axial direction. May have. The housing may have an arbitrary cylindrical shape such as a cylindrical shape or a square tubular shape, but since the separation membrane element is usually cylindrical, it is preferably cylindrical. Further, inside the housing, a partition is provided to prevent mixing of the raw material gas supplied to the supply side end portion 51 and the non-permeated gas that has not permeated the separation membrane sheet provided in the separation membrane element. Can be done.

When two or more separation membrane elements are arranged in the housing, the raw material gas supplied to each separation membrane element may be supplied in parallel or in series. Here, supplying the raw material gas in parallel means that at least the raw material gas is distributed and introduced into a plurality of separation membrane elements, and supplying the raw material gas in series means that at least the raw material gas is discharged from the separation membrane element in the previous stage. Introducing a permeated gas and / or a non-permeated gas into the separation membrane element in the subsequent stage.

(Separator)
The separation device is a gas separation device for supplying the supply side space and the permeation side space separated from each other by the separation membrane sheet 10 and the raw material gas containing at least a specific gas component from the supply unit to the supply side space. The supply side inlet, the permeation side outlet for discharging the permeated gas containing a specific gas component that has permeated the separation membrane sheet 10 from the permeation side space, and the raw material gas that did not permeate the separation membrane sheet 10 into the supply side space. It may be provided with a non-permeable side outlet for discharging from.

The separation device is a gas separation device and can include at least one separation membrane module including the separation membrane element having the above-mentioned separation membrane sheet 10. The arrangement and number of separation membrane modules provided in the separation device can be selected according to the required processing amount, the recovery rate of a specific gas component, the size of the place where the separation device is installed, and the like.

(Gas separation method)
The separation membrane sheet 10 separates a supply side space for supplying a raw material gas containing a specific gas component and a permeation side space for receiving a permeated gas containing a specific gas component that has permeated the separation membrane sheet 10. Is. When gas separation is performed using the separation membrane sheet 10, in the gas separation method, the supply side space is provided on the side opposite to the second porous layer 12 of the separation membrane sheet 10, and the permeation side space is the first of the separation membrane sheet 10. A step of supplying the raw material gas to the supply side space after providing the two porous layers 12 side, a step of discharging the permeated gas from the permeation side space, and a step of discharging the raw material gas that did not permeate the separation membrane sheet from the supply side space. It can include a step of discharging.

When the separation membrane sheet 10 has the third porous layer 13 or the fourth porous layer 14, the supply side space is provided on the third porous layer 13 or the fourth porous layer 14 side of the separation membrane sheet 10.

The separation membrane sheet 10 used in the above-mentioned gas separation method is usually preferably used in a state of being incorporated in a separation membrane element or a separation membrane module.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these examples.

[Measurement of average pore size of the first porous layer]
The measurement was performed according to the measurement method according to ASTM F316-03 using the model CFP1500AXLC from the Capillary Flow Composer. 3. A porous metal disc insort with a diameter of 2.54 cm and a thickness of 3.175 mm as a bottom clamp of the sample chamber, and a porous metal disc insort with a thickness of 3.175 mm as a top clamp of the sample chamber. The measurement was performed using a hole having a diameter of 175 mm.

[Measurement of thickness]
The thicknesses of the first porous layer and the second porous layer were measured using "VL50AS" (flat terminal, pressing force: 0.1N) manufactured by Mitutoyo Co., Ltd.

[Measurement of Garley value]
PA-301 Garley type denso meter B type (manufactured by Tester Sangyo Co., Ltd., inner cylinder: height 254 mm, inner diameter 74 mm, outer diameter 76.2 mm, mass 567 g, outer cylinder: height 254 mm, inner diameter 82.6 mm) The Garley values of the first porous layer and the second porous layer were measured by a method according to JIS L1096. For each of the first porous layer and the second porous layer, sample pieces of about 50 mm × 50 mm were collected from five different locations, and the sample pieces were fixed between the gasket and the tightening plate. Next, under constant pressure (due to the weight of the inner cylinder), the time required for 300 mL of air to ventilate the sample (ie, the number of Garleys) was measured. For the five sample pieces, the average value of the measurement results at three different points of each sample piece was taken as the Garley value.

[Measurement of basis weight and basis weight deviation of the second porous layer]
The separation membrane sheet was taken out from the separation membrane elements obtained in Examples and Comparative Examples. The removed separation membrane sheet was washed with water and dried to remove the gel-like separation functional layer. After washing, the second porous layer was peeled off from the separation membrane sheet. In the peeling of the second porous layer, the adhesive interposed between the first porous layer and the second porous layer was dissolved in ethyl acetate and then peeled off.

The peeled second porous layer was divided into three in the width direction, and a measurement sample of 250 mm (width direction) × 200 mm was cut out from the portion of each region excluding the sealing portion. The width direction was set to be parallel to the axis of the central canal in the separation membrane element produced in Examples and Comparative Examples. The weight and area of each of the cut out measurement samples were measured to calculate the grain (weight [g] / area [m ² ]). The basis weight deviation was calculated from the following formula based on the basis weight value of each measurement sample.
Basis weight deviation = {sigma [(basis weight of each sample for measurement) - (average of basis weight of the three test ^{sample)] 2/3} 0.5}
In the above formula, Σ means that the squared value of the difference between the basis weight of the measurement sample and the average value of the basis weights of the three measurement samples is calculated and added for each measurement sample.

[Airtightness test of separation membrane element]
As shown in FIG. 4, the separation membrane element 22 is separated from the supply side end 51 side of the supply side space portion of the separation membrane element 22 and the discharge port 52 side of the central canal 5 by the separation membrane sheet 10. It was fixed in the stainless steel housing 36 in the test apparatus N. The discharge port 52 side of the central canal 5 was led out to the outside of the housing 36, and the other side was closed. The supply-side end 51 and the discharge-side end of the supply-side space portion of the separation membrane element 22 are opened in the housing 36. That is, the gas supplied to the housing 36 was allowed to flow into the separation membrane element 22 from both ends of the supply side space portion (supply side end portion 51 and discharge side end portion) of the separation membrane element 22.

A cylinder for supplying nitrogen (N ₂ ) gas was attached to the housing 36 via a valve, and a pressure gauge 35 for measuring the pressure inside the housing 36 was attached. In the housing 36, by supplying the _{N 2} gas at room temperature (20 ° C.), the supply-side end portion 51 side and the discharge side end portion of the separation membrane element 22, pressure is applied to the 1600KPaA (absolute pressure). The pressure was confirmed with a pressure gauge 35. On the other hand, the pressure on the discharge port 52 side of the central canal 5 was adjusted to atmospheric pressure.

While maintaining this state, by measuring the time variation of the pressure within the housing 36 by the pressure gauge 35, performs a leak test of the separation membrane element 22 were N ₂ gas permeation performance evaluation of the separation membrane element 22. _{Specifically, the permeance of N 2} (mol / (m ² · s · kPa)) is calculated based on the time change of the measured pressure, ^{and the permeance is 1.0 × 10-7} mol / (m ^2). If it is s · kPa) or less, it is evaluated as A as the airtightness of the separation membrane element 22 is maintained, and the permeance is more than 1.0 × 10 ⁻⁷ mol / (m ² · s · kPa). The case was evaluated as B.

[Example 1]
(Preparation of separation membrane sheet)
In a container, 1000 parts by weight of water as a medium, 24.79 parts by weight of crosslinked polyacrylic acid as a hydrophilic resin (“Akpec HV-501” manufactured by Sumitomo Seika Co., Ltd.) and non-crosslinked polyacrylic acid (Sumitomo Sei). "Akpana AP-40F" manufactured by Kasha Co., Ltd. (40% Na saponification) was charged in an amount of 4.96 parts by weight to obtain a dispersion liquid in which a hydrophilic resin was dispersed in water. To this dispersion, 236.03 parts by weight of a 50% cesium hydroxide aqueous solution was added and mixed, then 78.76 parts by weight of a 10% sodium phosphite aqueous solution was added and mixed as an additive, and a further 10% surfactant was added. (“Surflon S-242” manufactured by AGC Seimi Chemical Co., Ltd.) An aqueous solution was added in an amount of 7.44 parts by weight and mixed to obtain a coating liquid. The obtained coating liquid was applied onto one surface of a PTFE porous membrane having a thickness of 53 μm as the first porous layer and an average pore diameter of 0.1 μm, and then used as the third porous layer in the first porous layer. It was covered with the same PTFE porous membrane as the one and dried at a temperature of about 120 ° C. for about 15 minutes. A PPS non-woven fabric (thickness 178 μm, basis weight 82.6 g / m ^{2 ) having a basis weight deviation of 0.24 g / m 2} was laminated as a second porous layer on the side opposite to the coated surface of the first porous layer. As a result, the separation membrane sheet 10 including the second porous layer 12, the first porous layer 11, the separation functional layer 15 which is a non-porous and gel-like resin composition layer, and the third porous layer 13 in this order is provided. Made.

(Preparation of separation membrane element)
The separation membrane sheet 10 obtained in the preparation of the separation membrane sheet was cut to a length of 1.575 mm, and the cut separation membrane sheet 10 was folded in half with the second porous layer 12 side to the outside, and the flow path on the supply side was formed. A film leaf was obtained by sandwiching the member 3.

A central canal was fixed to one end of the permeation side flow path member 4 of the first layer using an epoxy adhesive. The film leaf obtained above was laminated on the permeation side flow path member 4 of the first layer. The membrane leaf was laminated on the first layer of the transmission side flow path member 4 so that the fold portion of the separation membrane sheet 10 was parallel to the axial direction of the central canal and the crease portion was located on the central tube side. Further, the same adhesive as above is applied to the three edge portions of the membrane leaf except for the edge located at the crease portion of the separation membrane sheet 10, and the first layer transmission side flow path member 4 and the membrane leaf are attached. It fits.

Subsequently, the same adhesive as above is applied to the three edge portions of the first layer membrane leaf opposite to the permeation side flow path member 4 of the first layer, except for the edge located at the crease portion, as described above. After that, the second layer of the transmission side flow path member was laminated. The second film leaf was laminated on the side opposite to the first film leaf of the second layer permeation side flow path member in the same manner as the first film leaf. At this time, the stacking position of the second layer film leaf was set so that the position of the edge portion of the crease portion was offset (shifted) in the direction orthogonal to the crease portion and in the direction away from the central canal. By repeating this series of operations, a laminated body in which the permeation side flow path member 4 and the membrane leaf were alternately laminated three by three was obtained.

In the laminated body, on the surface where the central tube and the film leaf of the first layer transmission side flow path member are not laminated and the uppermost film leaf, both ends extending along the direction orthogonal to the axial direction of the central tube are described above. The same adhesive as above was applied, and the laminate was wound around the central tube to form a wound body, and a heat-resistant tape as an outer peripheral tape was wound around the outer periphery of the wound body. After that, both ends in the axial direction of the winding body are cut, a telescope prevention plate is attached so as to be in contact with the cut surface, and an outer wrap (reinforcement) is made with a fiber reinforced resin in which glass fiber is impregnated with epoxy resin on the outermost periphery of the winding body. A layer) was formed to obtain a separation membrane element. The obtained separation membrane element was subjected to an airtightness test. The results are shown in Table 1.

[Example 2]
As the first porous layer and the third porous layer, the PTFE porous membrane having the average pore size, thickness, and Garley value shown in Table 1 was used, and as the second porous layer, the basis weight, basis weight deviation, thickness, and Gurley value PPS shown in Table 1 were used. A separation membrane element was obtained in the same manner as in Example 1 except that a non-woven fabric was used. The obtained separation membrane element was subjected to an airtightness test. The results are shown in Table 1.

[Example 3]
As the first porous layer and the third porous layer, the PTFE porous membrane having the average pore size, thickness, and Garley value shown in Table 1 was used, and as the second porous layer, the basis weight, basis weight deviation, thickness, and Gurley value PPS shown in Table 1 were used. A separation membrane element was obtained in the same manner as in Example 1 except that a non-woven fabric was used. The obtained separation membrane element was subjected to an airtightness test. The results are shown in Table 1.

[Comparative Example 1]
As the first porous layer and the third porous layer, the PTFE porous membrane having the average pore size, thickness, and Garley value shown in Table 1 was used, and as the second porous layer, the basis weight, basis weight deviation, thickness, and Gurley value PPS shown in Table 1 were used. A separation membrane element was obtained in the same manner as in Example 1 except that a non-woven fabric was used. The obtained separation membrane element was subjected to an airtightness test. The results are shown in Table 1.

3 Permeation side flow path member, 4 Permeation side flow path member, 5 Central tube, 10 Separation membrane sheet, 11 1st porous layer, 12 2nd porous layer, 13 3rd porous layer, 14 4th porous layer, 15 Separation function Layer, 20,21,21a Separation membrane element, 22 Separation membrane element, 35 Pressure gauge, 36 housing, 50 holes, 51 Supply side end, 52 Discharge port, 53 Discharge side end, 55 Telescope prevention plate, N test apparatus.

Claims (12)

A separation membrane sheet that selectively permeates a specific gas component.
It has a first porous layer, a separation functional layer laminated on the first porous layer, and a second porous layer laminated on the side opposite to the separation functional layer of the first porous layer.
The separation functional layer is a non-porous resin composition layer, and is
The first porous layer and the second porous layer are different porous layers from each other.
The average pore size of the first porous layer is 0.005 μm or more and 1 μm or less.
The thickness of the first porous layer is 5 μm or more and 150 μm or less.
A separation membrane sheet having a basis weight deviation of the second porous layer of 0.6 g / m ^{2 or less.} The separation membrane sheet according to claim 1, wherein the thickness of the first porous layer is smaller than the thickness of the second porous layer. The separation membrane sheet according to claim 1 or 2, wherein the air permeability of the first porous layer is smaller than the air permeability of the second porous layer. The separation membrane sheet according to any one of claims 1 to 3, wherein the resin composition layer is in the form of a gel. The separation functional layer contains a hydrophilic resin and contains
The separation membrane sheet according to any one of claims 1 to 4, wherein the first porous layer is hydrophobic. The separation membrane sheet according to any one of claims 1 to 5, wherein the first porous layer is a porous membrane. The separation membrane sheet according to any one of claims 1 to 6, wherein the second porous layer is a non-woven fabric. The separation membrane sheet according to any one of claims 1 to 7, wherein the separation functional layer contains a carrier that reversibly reacts with the specific gas component. The separation membrane sheet according to any one of claims 1 to 8, wherein the specific gas component is an acid gas. A separation membrane element comprising the separation membrane sheet according to any one of claims 1 to 9.
A supply-side flow path member that forms a flow path through which the raw material gas containing the specific gas component flows, and
Includes a permeation side flow path member that forms a flow path through which the permeated gas that has permeated the separation membrane sheet flows.
The supply-side flow path member is arranged on the side of the separation membrane sheet opposite to the second porous layer.
The permeation side flow path member is a separation membrane element arranged on the second porous layer side of the separation membrane sheet. The separation membrane element according to claim 10,
A raw material gas supply port communicating with a flow path formed by the supply side flow path member of the separation membrane element,
Non-permeated gas outlet and
A separation membrane module including a permeation gas discharge port communicating with a flow path formed by the permeation side flow path member of the separation membrane element. A separation device including at least one separation membrane module according to claim 11.

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