JP2013027806A - Carbon dioxide separation membrane, support for carbon dioxide separation membrane, and method of manufacturing them - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a carbon dioxide separation membrane which is excellent in carbon dioxide separation performance and has a long lifetime, a support for a carbon dioxide separation membrane which is suitable for the carbon dioxide separation membrane, and a method of manufacturing them.SOLUTION: The carbon dioxide separation membrane includes: a carbon dioxide separation layer which includes a water-soluble polymer and a carbon dioxide carrier; and a porous support which is provided with a hydrophobic porous substrate and a polymer film having a hydrophilic group on at least one surface of the porous substrate and makes contact with the carbon dioxide separation layer through the polymer film to support the carbon dioxide separation layer.

Description

  The present invention relates to a carbon dioxide separation membrane, a support for carbon dioxide separation membrane, and a production method thereof.

  A membrane technology (hereinafter referred to as “membrane separation method”) for selectively separating carbon dioxide from a gas in which a plurality of components is mixed has been developed. The membrane separation method is a method in which separation is performed by carbon dioxide partial pressure in two regions partitioned by a membrane, and has the advantages of low energy consumption and a compact installation area. In addition, because the capacity of the system can be increased or decreased by increasing or decreasing the filter unit, it has excellent scalability.

Carbon dioxide separation membranes used in membrane separation methods are roughly classified into dissolution diffusion membranes and facilitated transport membranes. In the membrane separation method using the dissolution diffusion membrane, the separation is performed by utilizing the difference between the solubility in the membrane and the diffusivity in the membrane between carbon dioxide and another gas. In the membrane separation method using a facilitated transport membrane, carbon dioxide is transported from the gas supply side to the opposite side of the membrane by a carbon dioxide carrier (a substance having an affinity for carbon dioxide) contained in the membrane to perform separation. .
Since the dissolution and diffusion membrane performs separation based on the difference between the solubility and diffusion rate of carbon dioxide and other gases in the membrane, the degree of gas separation is uniquely determined if the material and physical properties of the membrane are determined. Further, since the carbon dioxide permeation rate increases as the film thickness decreases, the film is generally manufactured as a thin film of 1 μm or less by applying a layer separation method or an interfacial polymerization method.
On the other hand, the facilitated transport film contains carbon dioxide carrier in the film, thereby dramatically increasing the solubility of carbon dioxide and transporting it at a high concentration. Therefore, the degree of separation is generally higher than that of the dissolution diffusion membrane, and the carbon dioxide permeation rate is faster. Further, since the concentration of carbon dioxide in the membrane is high, the diffusion of carbon dioxide in the membrane is rarely rate-limiting, and a thick membrane of 1 μm or more is preferable from the viewpoint of increasing the degree of separation. .

Until now, in order to improve the performance of the facilitated transport membrane, a technique for improving the stability of the membrane and the retention of the carbon dioxide carrier has been developed, and the following carbon dioxide separation membrane has been proposed.
For example, after the plasma treatment of the porous polymer membrane, the hydrophilic vinyl monomer vapor is brought into contact with the plasma-treated porous polymer membrane for graft polymerization, and then the hydrophilic polymer surface thus obtained A carbon dioxide separation membrane obtained by impregnating and holding a carbon dioxide carrier liquid in a porous polymer membrane having a layer is disclosed (for example, see Patent Document 1).
Further, after an uncrosslinked vinyl alcohol-acrylate copolymer aqueous solution is applied in a film form on a carbon dioxide permeable support, it is heated and cross-linked to make water insoluble. A carbon dioxide separation membrane obtained by gelling by absorbing an aqueous solution containing a carrier is disclosed (for example, see Patent Document 2).
In addition, a carbon dioxide separation membrane is disclosed in which a gel layer obtained by adding cesium carbonate or the like to a polyvinyl alcohol-polyacrylic acid copolymer gel membrane is supported on a hydrophilic porous membrane (for example, see Patent Document 3). .

Japanese Patent Laid-Open No. 7-60078 Japanese Patent Publication No. 7-102310 JP 2009-195900 A

  However, the carbon dioxide separation membrane disclosed in Patent Documents 1 to 3 shows a decrease in separation performance with use. In the market, a carbon dioxide separation membrane having a longer lifetime is desired.

Conventionally, carbon dioxide separation membranes have been studied for the type of carbon dioxide carrier, focusing on the dissolution reaction of carbon dioxide. For example, cesium carbonate is a carbon dioxide carrier exhibiting excellent separation performance, but the separation performance will be saturated by a certain amount no matter how much the amount is increased. Furthermore, after wet heat aging, a phenomenon was observed in which cesium carbonate exudes from the layer containing carbon dioxide carrier to the support and the separation performance deteriorates, and this was more remarkable as the amount of cesium carbonate increased.
Therefore, in order to further improve the separation performance of the carbon dioxide separation membrane, it was considered necessary to improve the carbon dioxide desorption reaction.

  In view of the above circumstances, the present invention provides a carbon dioxide separation membrane having excellent carbon dioxide separation performance and a long life, a carbon dioxide separation membrane support suitable for the carbon dioxide separation membrane, and methods for producing these. It aims at this and makes this a subject.

  In order to achieve the above object, the following invention is provided.

<1> A carbon dioxide separation layer containing a water-soluble polymer and a carbon dioxide carrier, a hydrophobic porous substrate, and a polymer coating having a hydrophilic group provided on at least one surface of the porous substrate And a porous support that contacts the carbon dioxide separation layer via the polymer coating and supports the carbon dioxide separation layer.
<2> The carbon dioxide separation membrane according to <1>, wherein the polymer film has at least one of an ion exchange group and a chelate group.
<3> The carbon dioxide separation membrane according to <1> or <2>, wherein the polymer coating has a thickness of 1 μm or less.
<4> The polymer coating has at least one of a carboxy group, a sulfonic acid group, a phosphoric acid group, a hydroxy group, an amino group, an epoxy group, an acrylamide group, an isocyanate group, and an acid chloride group as a hydrophilic group. The carbon dioxide separation membrane according to any one of <1> to <3>.
<5> The porous substrate contains at least one of polytetrafluoroethylene, polyethersulfone, polyphenylene sulfide, polysulfone, polypropylene, polyetherimide, polyetheretherketone, and polyvinylidene fluoride. The carbon dioxide separation membrane according to any one of <4>.
<6> A support for a carbon dioxide separation membrane comprising a hydrophobic porous substrate and a polymer film having a hydrophilic group, which is present as an outermost layer on at least one surface of the porous substrate.
<7> The support for carbon dioxide separation membrane according to <6>, wherein a contact angle between the surface of the polymer coating and water is less than 120 degrees.
<8> The support for carbon dioxide separation membrane according to <6> or <7>, wherein the polymer film has at least one of an ion exchange group and a chelate group.
<9> An application step of applying a polymerizable composition containing a radical polymerizable monomer to at least one surface of a hydrophobic porous substrate, and irradiating the applied polymerizable composition with active energy rays And a polymerization step for forming a polymer film.
<10> The method for producing a carbon dioxide separation membrane support according to <9>, further including an addition treatment step of adding at least one of an ion exchange group and a chelate group to the polymer coating.
<11> The method for producing a carbon dioxide separation membrane support according to <9> or <10>, wherein the radical polymerizable monomer includes at least one of acrylate, methacrylate, acrylamide, acrylic acid, and derivatives thereof. .
<12> The support for carbon dioxide separation membrane according to any one of <6> to <8> or the support for carbon dioxide separation membrane according to any one of <9> to <11>. A carbon dioxide separation membrane support produced by the method for producing a body is used, and a composition containing a water-soluble polymer and a carbon dioxide carrier is applied to the surface of the support having the polymer coating to obtain a coating membrane. A method for producing a carbon dioxide separation membrane, comprising: a coating step; a cooling step of cooling the coating membrane to obtain a gel membrane; and a drying step of drying the gel membrane to form a dry membrane.
<13> The method for producing a carbon dioxide separation membrane according to <12>, further including a crosslinking step of crosslinking the dry membrane.

  According to the present invention, a carbon dioxide separation membrane having excellent carbon dioxide separation performance and a long life, a carbon dioxide separation membrane support suitable for the carbon dioxide separation membrane, and a method for producing them are provided.

Hereinafter, embodiments of the present invention will be sequentially described. In addition, these description and Examples illustrate this invention, and do not restrict | limit the scope of the present invention.
In this specification, the term “process” is not limited to an independent process, and is included in the term if the intended action of the process is achieved even when it cannot be clearly distinguished from other processes. .
In the present specification, a numerical range indicated using “to” indicates a range including the numerical values described before and after “to” as the minimum value and the maximum value, respectively.

<Carbon dioxide separation membrane>
The carbon dioxide separation membrane of the present invention is
A carbon dioxide separation layer comprising a water-soluble polymer and a carbon dioxide carrier;
A hydrophobic porous substrate, and a polymer film having a hydrophilic group provided on at least one surface of the porous substrate, in contact with the carbon dioxide separation layer via the polymer film, A porous support for supporting the carbon dioxide separation layer;
Is provided.
The carbon dioxide separation membrane having such a structure is provided with a polymer film having a hydrophilic group on at least one surface of a hydrophobic porous substrate, and the porous support and the carbon dioxide separation layer are interposed via the polymer film. , The carbon dioxide separation performance is excellent and the life is long.

As a result of investigations by the present inventors, it was confirmed that a reaction represented by the following formula (1) occurred on the CO ₂ releasing side of the facilitated transport film, and the desorption reaction of carbon dioxide progressed.

HCO ₃ ⁻ + H ⁺ → CO ₂ + H ₂ O (1)

In the carbon dioxide separation membrane of the present invention, the polymer film having a hydrophilic group is H ⁺ (at the interface where the porous support and the carbon dioxide separation layer are in contact, that is, the CO ₂ release side surface of the carbon dioxide separation layer. By acting so as to supply protons, the reaction of the above formula (1) is promoted, and as a result, the carbon dioxide separation performance is considered to be improved.
In addition, the carbon dioxide separation membrane of the present invention has a contact between the porous support and the carbon dioxide separation layer via a polymer film having a hydrophilic group, so that the porous support and the carbon dioxide separation layer are in contact with each other. It is considered that the adhesion is good, and as a result, the separation performance is maintained high even if the use is continued, and the life is long.
In addition, the mechanism mentioned above is a mechanism estimated, and this invention is not restrained by a specific theory.

(Carbon dioxide separation layer)
The carbon dioxide separation membrane of the present invention includes a carbon dioxide separation layer. The carbon dioxide separation layer contains at least a water-soluble polymer and a carbon dioxide carrier, and may contain other components as necessary. The carbon dioxide separation layer transports carbon dioxide from the CO ₂ supply side to the opposite side by the action of the carbon dioxide carrier.

[Water-soluble polymer]
The water-soluble polymer functions as a binder, holds moisture in the carbon dioxide separation layer, and exhibits a carbon dioxide separation function by a carbon dioxide carrier. The water-soluble polymer is preferably one having high water absorption from the viewpoint that it can be dissolved in an aqueous solvent to form a coating solution and the carbon dioxide separation layer has high water absorption (humidity retention). Moreover, the thing with the high holding power of a carbon dioxide carrier is preferable.

As the water-soluble polymer, the polymer species is not particularly limited. From the viewpoint of water absorption, film-forming property, strength, etc., for example, polyvinyl alcohol-polyacrylic acid copolymer, polyethylene oxide, polyacrylic acid metal salt, polycarboxymethylcellulose metal salt, starch polyacrylic acid metal salt-polyvinyl alcohol A copolymer (random or block polymer), polyvinylpyrrolidone, poly N vinylacetamide, poly N vinylacetamide-polyacrylic acid metal salt copolymer (random or block polymer), poly 2-hydroxyethyl methacrylate, etc. are suitable. is there.
As the water-soluble polymer, polyvinyl alcohol-polyacrylate copolymer is particularly preferable. The polyvinyl alcohol-polyacrylate copolymer has a high water absorption capacity and a high hydrogel strength even at high water absorption. The content of polyacrylate in the polyvinyl alcohol-polyacrylate copolymer is, for example, 5 mol% to 95 mol%, preferably 5 mol% to 70 mol%, more preferably 5 mol% to 60 mol%, More preferably, it is 5 mol%-50 mol%. Examples of the polyacrylate include ammonium salts and organic ammonium salts in addition to alkali metal salts such as sodium salts and potassium salts.
Examples of the commercially available polyvinyl alcohol-polyacrylate copolymer (sodium salt) include Sumikagel L-5H (manufactured by Sumitomo Chemical Co., Ltd.) and Clastomer AP20 (manufactured by Kuraray Co., Ltd.).
Two or more kinds of the water-soluble polymers may be mixed and used.

  In the case where the water-soluble polymer is a water-soluble polymer having a single type of crosslinkable group, it is preferable that the water-soluble polymer has an affinity for water and has a molecular weight of 110,000 or more. Examples of the crosslinkable group include a hydroxy group, a carboxy group, a vinyl group, an aldehyde group, an amino group, and a cyano group, but there is no need to be limited to these functional groups. Among these, considering the affinity with the carbon dioxide carrier and the carrier carrying effect, polyvinyl alcohol having a hydroxy group is preferable. More preferably, the polyvinyl alcohol has a molecular weight of 130,000 or more.

[Carbon dioxide carrier]
Any carbon dioxide carrier may be used as long as it has an affinity for carbon dioxide and exhibits water solubility. The carbon dioxide carrier in this case is a substance having an affinity for carbon dioxide, and various water-soluble inorganic and organic substances showing basicity are used. For example, alkali metal ions in an aqueous solution containing alkali metal carbonate and / or alkali metal bicarbonate and / or alkali metal hydroxide, alkali metal carbonate and / or alkali metal bicarbonate and / or alkali metal hydroxide. An aqueous solution to which a polydentate ligand that forms a complex with ammonia, ammonia, ammonium salts, various linear and cyclic amines, amine salts, ammonium salts, and the like are included. These water-soluble derivatives can also be preferably used. Two or more carbon dioxide carriers may be used in combination.

Examples of the alkali metal carbonate include lithium carbonate, sodium carbonate, potassium carbonate, rubidium carbonate, and cesium carbonate.
Examples of the alkali metal bicarbonate include lithium hydrogen carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, rubidium hydrogen carbonate, and cesium hydrogen carbonate.
Examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, and cesium hydroxide.
Among these, a compound containing potassium, rubidium and cesium is preferable from the viewpoint of good affinity with carbon dioxide.
Since the carbon dioxide carrier is advantageously retained in the separation layer for a long time, alkali metal carbonates and / or alkali metal bicarbonates and / or alkali metal hydroxides and amines that are difficult to evaporate such as amino acids and betaines It is also preferable to use the containing compound in combination.

Examples of the alkanolamine include various water-soluble substances such as monoethanolamine, diethanolamine, triethanolamine, monopropanolamine, dipropanolamine, and tripropanolamine. The carbon dioxide carrier is not limited to those described above, and any carbon dioxide carrier may be used as long as it has an affinity for carbon dioxide and exhibits water solubility, and various types of organic acid alkali metal salts can be used. it can.
As the polydentate ligand that forms a complex with an alkali metal ion, conventionally known ones such as: 12-crown-4, 15-crown-5, 18-crown-6, benzo-12-crown-4, benzo -15-crown-5, benzo-18-crown-6, dibenzo-12-crown-4, dibenzo-15-crown-5, dibenzo-18-crown-6, dicyclohexyl-12-crown-4, dicyclohexyl-15 -Cyclic polyethers such as crown-5, dicyclohexyl-18-crown-6, n-octyl-12-crown-4, n-octyl-15-crown-5, n-octyl-18-crown-6; 2.1], cyclic polyether amines such as cryptand [2.2]; cryptand [2.2.1], cryptand [2] 2.2], other bicyclic polyether amines etc. can be used porphyrins, phthalocyanines, polyethylene glycol, ethylene diamine tetraacetic acid and the like.

[Other ingredients]
The carbon dioxide separation layer can contain other components (additives) other than the hydrophilic polymer and the carbon dioxide carrier as long as they do not adversely affect the film-forming properties (coating properties, set properties) and gas separation properties. Examples thereof include a crosslinking agent, a surfactant, a catalyst, a moisturizing (water absorbing) agent, an auxiliary solvent, a film strength adjusting agent, and a defect detecting agent. A crosslinking agent is synonymous with the thing in the manufacturing method of the carbon dioxide separation membrane mentioned later, and its preferable aspect is also the same.

The carbon dioxide separation layer may contain a nitrogen-containing compound or a sulfur oxide that promotes a reaction between carbon dioxide and a carbon dioxide carrier.
Examples of the nitrogen-containing compound include amino acids such as glycine, alanine, serine, proline, histidine, taurine, and diaminopropionic acid, hetero compounds such as pyridine, histidine, piperazine, imidazole, and triazine, monoethanolamine, diethanolamine, Alkanolamines such as triethanolamine, monopropanolamine, dipropanolamine, tripropanolamine, cyclic polyetheramines such as cryptand [2.1] and cryptand [2.2], cryptand [2.2.1] ], Bicyclic polyetheramines such as cryptand [2.2.2], porphyrin, phthalocyanine, ethylenediaminetetraacetic acid and the like can be used.
As the sulfur compound, for example, amino acids such as cystine and cysteine, polythiophene, dodecylthiol and the like can be used.

  The carbon dioxide separation layer preferably has a thickness in the range of 1 μm to 200 μm from the viewpoint of combining strength, gas permeability, and separation performance. Furthermore, 5 micrometers-150 micrometers are more preferable, and 10 micrometers-100 micrometers are still more preferable.

In the carbon dioxide separation layer, the content of each component in a dry state is preferably in the following range.
5-60 mass% is preferable with respect to the total mass of a layer, and, as for a hydrophilic polymer, 10-50 mass% is more preferable, and 15-40 mass% is still more preferable.
The carbon dioxide carrier is preferably 20 to 90% by mass, more preferably 30 to 80% by mass, and still more preferably 40 to 80% by mass with respect to the total mass of the layer. For example, when using a compound containing cesium as a carbon dioxide carrier, it is preferably 50% by mass or more and 55% by mass or more with respect to the total mass of the layer from the viewpoint of improving the separation performance of carbon dioxide. Is more preferable, and 60% by mass or more is particularly preferable.

  A carrier elution preventing layer may be provided on the surface of the carbon dioxide separation layer on the side opposite to the side in contact with the porous support, if necessary, in order to prevent elution of carbon dioxide carriers. The carrier elution preventing layer preferably has a property of transmitting a gas such as carbon dioxide and water vapor but not a liquid such as water, and is preferably a hydrophobic porous film. A film having such properties may be applied on the film surface, or a separately prepared film may be laminated.

(Porous support)
The carbon dioxide separation membrane of the present invention includes a porous support including a hydrophobic porous substrate and a polymer film having a hydrophilic group. In the porous support, the polymer coating may be provided on at least one surface of the porous substrate. The porous support has a carbon dioxide separation layer formed on the surface having the polymer coating, and supports the carbon dioxide separation layer. The said porous support body is synonymous with the support body for carbon dioxide separation membrane of this invention mentioned later, and its preferable aspect is also the same.

<Support for carbon dioxide separation membrane>
The support for carbon dioxide separation membrane of the present invention is
A hydrophobic porous substrate;
And a polymer film having a hydrophilic group, which is provided on at least one surface of the porous substrate and exists as an outermost layer.
When a carbon dioxide separation layer is formed on the surface of the support for the carbon dioxide separation membrane having such a structure to form a carbon dioxide separation membrane, the carbon dioxide separation membrane is excellent in carbon dioxide separation performance. And long life.

[Hydrophobic porous substrate]
The porous substrate is not particularly limited as long as it has carbon dioxide permeability, can form a carbon dioxide separation layer on one surface, and can support this membrane.
As the material of the porous substrate, paper, fine paper, coated paper, cast coated paper, synthetic paper, cellulose, polyester, polyolefin, polyamide, polyimide, polysulfone, aramid, polycarbonate, metal, glass, ceramics, etc. are suitable. Can be used. More specifically, resin materials such as polyethylene, polystyrene, polyethylene terephthalate, polytetrafluoroethylene, polyethersulfone, polyphenylene sulfide, polysulfone, polypropylene, polyetherimide, polyetheretherketone and polyvinylidene fluoride can be suitably used. . Among these, from the viewpoint of durability, at least one of polytetrafluoroethylene, polyethersulfone, polyphenylene sulfide, polysulfone, polypropylene, polyetherimide, polyetheretherketone, and polyvinylidene fluoride is preferable, and polytetrafluoroethylene is preferable. From the viewpoint of stability over time, it can be particularly preferably used.

As the form of the porous substrate, a woven fabric, a non-woven fabric, a porous membrane, or the like can be adopted. In general, a support having a high self-supporting property and a high porosity can be preferably used. Polyphenylene sulfide, polysulfone, cellulose membrane filter membrane, polytetrafluoroethylene, polyvinylidene fluoride, stretched porous membrane of high molecular weight polyethylene, etc. are preferable from the viewpoints of high porosity, small diffusion inhibition of carbon dioxide, and strength and suitability for production. . Among these, a stretched film of polytetrafluoroethylene is particularly preferable.
Although these porous base materials can be used alone, a composite membrane integrated with a reinforcing membrane can also be suitably used.

  The porous substrate preferably has a thickness in the range of 30 μm to 500 μm from the viewpoint of combining gas permeability and strength. When the thickness is 500 μm or less, the gas permeability is good, and when it is 30 μm or more, the strength is good. Furthermore, 50 micrometers-300 micrometers are more preferable, and 50 micrometers-200 micrometers are still more preferable.

[Polymer film having hydrophilic group]
The porous substrate has a polymer film having a hydrophilic group on at least one surface. The polymer coating is present as the outermost layer on at least one surface of the carbon dioxide separation membrane support.
Examples of the polymer coating include a layer having a microporous membrane shape, a nonwoven fabric shape, a woven fabric shape, and other three-dimensional network-like porous structures. The polymer film is preferably a microporous film. Here, the microporous membrane has a structure in which a large number of micropores are connected and these micropores are connected, and a gas or liquid can pass from one surface to the other. It is.
The polymer coating may be on at least one surface of the porous substrate, and may be on both surfaces. From the viewpoint of manufacturing cost and application suitability, it is preferable to be on one side, and from the viewpoint of the module form which is the actual usage form, it is preferable to be on both sides.
The polymer film preferably covers the entire surface of at least one surface of the porous substrate.

The polymer coating is present as the outermost layer on the surface portion of at least one surface of the carbon dioxide separation membrane support.
The said surface part is the range of 1 micrometer or less from the exposed surface of a support body, for example.
The presence of the polymer coating as the outermost layer means that the polymer coating forms the exposed surface of the support.

-Hydrophilic group-
Since the polymer coating has a hydrophilic group, it can impart hydrophilicity to the surface of the porous substrate. The hydrophilic group is not particularly limited, but carboxy group, sulfonic acid group, phosphoric acid group, hydroxy group, amino group, epoxy group, acrylamide group, isocyanate group, acid chloride group, nitro group, thio group, imino group. , S-oxide group and the like. Among these, from the viewpoint of durability and gas permeation performance, at least one of a carboxy group, a sulfonic acid group, a phosphoric acid group, a hydroxy group, an amino group, an epoxy group, an acrylamide group, an isocyanate group, and an acid chloride group is preferable. Most preferred is at least one sulfonic acid group.

  The amount of the hydrophilic group is not particularly limited. From the viewpoint of carbon dioxide separation performance and long life, the polymer coating preferably has many hydrophilic groups.

-Ion exchange group and chelate group-
The polymer coating preferably has at least one of an ion exchange group and a chelate group. In the present invention, the ion exchange group and the chelate group may not be clearly distinguishable from the hydrophilic group.
When the polymer coating has at least one of an ion exchange group and a chelate group, it is difficult for the carbon dioxide carrier to exude from the carbon dioxide separation layer to the support. This is considered to be due to the fact that the ion exchange group and the chelate group can capture the carbon dioxide carrier to be diffused from the carbon dioxide separation layer into the inside of the support.
In addition, since the ion exchange group is also a hydrophilic group, when the polymer film has an ion exchange group, the separation performance of the carbon dioxide separation membrane is improved, and the separation performance is maintained high even if the use is continued. Is done.

  The ion exchange group is a functional group that captures metal ions and the like by ionic bonds. The ion exchange group is not particularly limited as long as it is a functional group that ion-bonds with a metal ion or the like, and can be appropriately selected according to the purpose. Examples include cation exchange groups such as sulfonic acid groups, phosphoric acid groups, and carboxy groups, primary amino groups, secondary amino groups, tertiary amino groups, quaternary amino groups, quaternary amino groups, and cation exchange groups such as quaternary ammonium groups. It is done.

  The chelate group is a functional group that captures a metal ion or the like by a chelate (coordination) bond. The chelate group is not particularly limited as long as it is a functional group that forms a chelate (coordination) bond with a metal ion or the like, and can be appropriately selected according to the purpose. For example, nitrilotriacetic acid derivative (NTA) group, iminodiacetic acid group, iminodiethanol group, aminopolycarboxylic acid, aminopolyphosphonic acid, aminotrimethylenephosphonic acid, porphyrin skeleton, phthalocyanine skeleton, cyclic ether, cyclic amine, phenol and lysine derivatives , Phenanthroline group, terpyridine group, bipyridine group, triethylenetetraamine group, diethylenetriamine group, tris (carboxymethyl) ethylenediamine group, diethylenetriaminepentaacetic acid group, polypyrazolylboric acid group, 1,4,7-triazocyclononane Groups, multidentate ligands such as a dimethylglyoxime group and a diphenylglyoxime group.

  When the carbon dioxide carrier contained in the carbon dioxide separation layer is an alkali metal carbonate, the ion exchange group is preferably a sulfonic acid group. The chelate group is preferably aminotrimethylene phosphonic acid when the carbon dioxide carrier contained in the carbon dioxide separation layer is an alkali metal carbonate. When the above ion exchange groups and chelate groups are used, the alkali metal carbonate can be well prevented from seeping out onto the support.

  There is no restriction | limiting in particular as the quantity of the said ion exchange group and a chelate group. From the viewpoint of being able to suppress well the exudation of the carbon dioxide carrier to the support, the molar ratio is preferably 0.001% or more with respect to all the functional groups on the outermost surface of the support, More preferably. On the other hand, from the viewpoint of carbon dioxide separation performance, the molar ratio is preferably 90% or less, more preferably 80% or less, with respect to all functional groups on the outermost surface of the support.

The polymer coating preferably has a thickness of 1 μm or less. When the film thickness is 1 μm or less, the carbon dioxide separation performance of the carbon dioxide separation membrane support is good. More preferably, the film thickness is 100 nm or less, and still more preferably, the film thickness is 10 nm or less. The lower limit of the film thickness of the polymer coating is preferably 1 nm or more, and more preferably 3 nm or more from the viewpoint of maintaining separation performance when the use is continued.
The film thickness (distance from the outermost surface to the hydrophobic porous substrate) of the polymer coating can be measured by secondary ion mass spectrometry.

  The carbon dioxide separation membrane support preferably has a contact angle between the surface of the polymer coating and water of less than 120 degrees. When the contact angle is less than 120 degrees, when the aqueous composition is applied on the surface to form the carbon dioxide separation layer, the composition has good wettability and excellent adhesion to the carbon dioxide separation layer. The contact angle is more preferably less than 90 degrees from the above viewpoint.

  The polymer coating may be prepared separately from a film having a porous structure and bonded to the porous substrate. In the present invention, a radical polymerizable monomer is provided on the surface of the porous substrate. A film formed by polymerization is preferred. Hereinafter, the manufacturing method of the support body for carbon dioxide separation membranes is demonstrated, and the said polymer film is explained in full detail.

<Method for producing support for carbon dioxide separation membrane>
The method for producing a support for carbon dioxide separation membrane of the present invention comprises:
An application step of applying a polymerizable composition containing a radical polymerizable monomer to at least one surface of a hydrophobic porous substrate;
And a polymerization step of irradiating the applied polymerizable composition with active energy rays to form a polymer film.
The manufacturing method may further include an addition treatment step of adding at least one of an ion exchange group and a chelate group to the polymer film.

(Coating process)
The application step is a step of applying a polymerizable composition containing a radical polymerizable monomer to at least one surface of a hydrophobic porous substrate. The polymerizable composition may contain at least one radical polymerizable monomer and other components such as a solvent, a radical polymerization initiator, a photosensitizer, and an antioxidant as necessary.

[Radically polymerizable monomer]
The radical polymerizable monomer is preferably at least one of acrylate, methacrylate, acrylamide, acrylic acid and derivatives thereof, and can be appropriately selected according to the purpose. For example, alkyl (meth) acrylates such as 1-hydroxy-2-propyl acrylate, 2-hydroxy-1-propyl acrylate, hydroxypropyl methacrylate, 2,3-dihydroxypropyl acrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, and hydroxyethyl methacrylate Glycidyl (meth) acrylates such as 4-hydroxybutyl acrylate glycidyl ether and glycidyl acrylate; primary amine (meth) acrylates such as aminoethyl methacrylate, dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate; urethane (meth) acrylate Acrylamide such as acrylamide, methacrylamide, ethacrylamide, N, N-dimethylacrylamide Amides, acrylic acid, acrylic acids such as methacrylic acid, acrylic acid chloride, and (meth) acrylic acid chloride such as methacrylic acid chloride or the like. These may be used alone or in combination of two or more.
Among these, glycidyl (meth) acrylates and acrylic acids are preferable in terms of good reactivity with a functional compound described later.

The radical polymerizable monomer includes a carboxy group, a sulfonic acid group, a phosphoric acid group, a hydroxy group, an amino group, an epoxy group, an acrylamide group, an isocyanate group, an acid chloride group, a nitro group, a thio group, an imino group, and an S-oxide group. It is preferable to contain a hydrophilic group such as By polymerizing a radically polymerizable monomer containing a hydrophilic group to form a polymer film, the polymer film can have a large amount of hydrophilic groups on the entire surface thereof. Therefore, the carbon dioxide separation membrane using the carbon dioxide separation membrane support is excellent in carbon dioxide separation performance and has a long life.
As the hydrophilic group, in particular, from the viewpoint of durability and gas permeation performance, at least carboxy group, sulfonic acid group, phosphoric acid group, hydroxy group, amino group, epoxy group, acrylamide group, isocyanate group and acid chloride group One is preferable, and at least one of a carboxy group and a sulfonic acid group is most preferable.

Examples of the radical polymerizable monomer containing a carboxy group include acrylic acid, methacrylic acid, carboxyethyl acrylate, and the like. Examples of the radical polymerizable monomer containing an amino group include dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate. Examples of the radical polymerizable monomer containing a hydroxy group include 4-hydroxybutyl acrylate and hydroxyethyl methacrylate. Examples of the radical polymerizable monomer containing an epoxy group include 4-hydroxybutyl acrylate glycidyl ether, glycidyl acrylate, and the like. Examples of the radical polymerizable monomer containing an acrylamide group include acrylamide and N, N-dimethylacrylamide. Examples of the radical polymerizable monomer containing an isocyanate group include urethane (meth) acrylates. Examples of the radical polymerizable monomer containing an acid chloride group include acrylic acid chloride.
There is no restriction | limiting in particular as said urethane (meth) acrylates, According to the objective, it can select suitably, A commercial item can be used. Examples of the commercially available products include Desmodur HL (Bayer AG, manufactured by Leverkusen), Roskydal UA VP LS 2265 (Bayer AG, manufactured by Leverkusen), and the like.

  There is no restriction | limiting in particular as content in the polymeric composition of the said radically polymerizable monomer, Although it can select suitably according to the objective, 0.1 mass%-30 mass% are preferable, 0.2 mass% -25% by mass is more preferable, and 0.3% by mass to 20% by mass is particularly preferable. When the content is 0.1% by mass or more, the entire coated surface can be hydrophilized, and when it is 30% by mass or less, there is no possibility of blocking the pores of the porous substrate.

[Radical polymerization initiator]
As the radical polymerization initiator, both a photo radical polymerization initiator and a thermal radical polymerization initiator can be suitably used.

  The radical photopolymerization initiator is not particularly limited and may be appropriately selected depending on the intended purpose. For example, the Irgacure series (for example, Irgacure 651, commercially available from Ciba Specialty Chemicals) IRGACURE 754, IRGACURE 184, IRGACURE 2959, IRGACURE 907, IRGACURE 369, IRGACURE 379, IRGACURE 819, etc.), DAROCURE series (eg DAROCURE TPO, DAROCURE 1173 etc.), Quantacure PD Examples include Ezacur series (for example, Ezacur TZM, Ezacur TZT, etc.) commercially available from the company.

  The thermal radical polymerization initiator is not particularly limited and may be appropriately selected depending on the intended purpose. For example, α, α′-azobisisobutyronitrile, SI series commercially available from Sanshin Chemical Co., Ltd. (For example, SI-100 etc.) etc. are mentioned.

  Although there is no restriction | limiting in particular as addition amount of the said radical polymerization initiator, 0.1 mass part-20 mass parts are preferable with respect to 100 mass parts of said radical polymerizable monomers, 0.5 mass part-15 mass parts Is more preferable, and 1.0 to 10 parts by mass is particularly preferable. When the addition amount is 0.1 parts by mass or more, the polymerization reaction proceeds rapidly, and when it is 20 parts by mass or less, sufficient film strength is obtained.

[solvent]
The solvent is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include water; alcohols such as methanol, ethanol, isopropanol and ethylene glycol; ketones such as acetone and methyl ethyl ketone (MEK); , Ethers such as dioxane and propylene glycol monomethyl ether acetate; dimethylformamide, dimethyl sulfoxide and the like.

[Photosensitizer]
A photosensitizer can be used in combination with the polymerizable composition as required. By using the photosensitizer, the reactivity is improved, and the mechanical strength and adhesive strength of the cured product can be improved.
The photosensitizer is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include carbonyl compounds, organic sulfur compounds, persulfides, redox compounds, azo and diazo compounds, halogen compounds, and photoreduction. Specific examples include benzoin derivatives such as benzoin methyl ether, benzoin isopropyl ether, α, α-dimethoxy-α-phenylacetophenone; benzophenone, 2,4-dichlorobenzophenone, methyl o-benzoylbenzoate Benzophenone derivatives such as 4,4′-bis (diethylamino) benzophenone; thioxanthone derivatives such as 2-chlorothioxanthone and 2-isopropylthioxanthone; anthraquinone derivatives such as 2-chloroanthraquinone and 2-methylanthraquinone; Examples include acridone derivatives such as lidone and N-butylacridone; α, α-diethoxyacetophenone, benzyl, fluorenone, xanthone, and uranyl compounds. These may be used alone or in combination of two or more.
Examples of commercially available photosensitizers include Anthracure (registered trademark) UVS-1331 (manufactured by Kawasaki Kasei Kogyo Co., Ltd.), Kayacure DETX-S (manufactured by Nippon Kayaku Co., Ltd.), and the like.

[Antioxidant]
The polymerizable composition may contain other additives such as an antioxidant as long as the effects of the present invention are not impaired. Examples of commercially available antioxidants include dibutylhydroxytoluene (BHT), Irganox 1010, Irganox 1035FF, Irganox 565, and the like.

  A conventionally known method can be adopted as a method for applying the polymerizable composition. Examples include curtain flow coaters, extrusion die coaters, air doctor coaters, blade coaters, rod coaters, knife coaters, squeeze coaters, reverse roll coaters, and bar coaters. Moreover, you may apply | coat a porous base material by immersing in the liquid of the said polymeric composition. From the viewpoint of film thickness uniformity, coating amount, etc., an extrusion die coater or coating by dipping is preferred.

(Polymerization process)
The polymerization step is a step of forming a polymer film by irradiating the polymerizable composition applied to the porous substrate with active energy rays. By this step, the radical polymerizable monomer contained in the polymerizable composition applied to the porous substrate is polymerized to form a polymer film.
The polymer coating is formed on the surface portion of the porous substrate. That is, a polymer film can be formed on the exposed surface of the porous substrate and also on the pore inner surface in the substrate from the surface to the inside (for example, a depth of up to 1 μm).

[Active energy rays]
Examples of the active energy rays used in the polymerization step include α rays, γ rays, electron beams, X rays, ultraviolet rays, visible light, and infrared rays.
The step of irradiating the active energy ray is a step of irradiating the polymerizable composition applied to the porous substrate with ultraviolet rays from, for example, an ultraviolet irradiation lamp. Thereby, the polymerizable monomer component in the polymerizable composition can be surely polymerized and cured. The light source for irradiating the active energy ray is not limited to the ultraviolet irradiation lamp, and a halogen lamp, a high-pressure mercury lamp, a laser, an LED, an electron beam irradiation device, or the like can also be employed.
The irradiation condition of the active energy ray is not particularly limited as long as the polymerizable compound can be polymerized and cured. The wavelength of the active energy ray is, for example, preferably 200 nm to 600 nm, more preferably 300 nm to 450 nm, and further preferably 350 nm to 420 nm. The output of the actinic energy ray is preferably at 5000 mJ / cm ² or ^less, more preferably ^{10mJ / cm 2 ~4000mJ / cm 2} , further preferably 20mJ / cm ² ~3000mJ / cm 2 .

(Additional process)
The addition treatment step is a step of adding at least one of an ion exchange group and a chelate group to the polymer coating. By this step, an ion exchange group and / or a chelate group can be added to the surface of the support for carbon dioxide separation membrane. The ion exchange group and chelate group in this step are synonymous with the ion exchange group and chelate group in the above-described support for carbon dioxide separation membrane, and the preferred embodiments are also the same.

The addition treatment step may be a step independent of the polymerization step, or may be a step performed simultaneously with the polymerization step.
The case where the addition treatment step is a step independent of the polymerization step is, for example, a polymer film in which a composition containing a functional compound having at least one of an ion exchange group and a chelate group is formed in the polymerization step. In this case, the polymer forming the polymer film is reacted with the functional compound by heat treatment or energy ray irradiation.
When the addition treatment step is a step performed simultaneously with the polymerization step, for example, the functional compound is added to the polymerizable composition used in the polymerization step, and the heat treatment is performed simultaneously with the formation of the polymer film. This is a case where a polymer forming a polymer film is reacted with the functional compound by irradiation with energy rays or the like.

  When the composition containing the functional compound is applied onto the polymer film formed in the polymerization step, the solvent for the composition is not particularly limited and can be appropriately selected depending on the purpose. Alcohols such as methanol, ethanol, isopropanol and ethylene glycol; ketones such as acetone and methyl ethyl ketone (MEK); ethers such as tetrahydrofuran, dioxane and propylene glycol monomethyl ether acetate; dimethylformamide, dimethyl sulfoxide, toluene and the like Can be mentioned.

[Functional compounds]
The functional compound is not particularly limited as long as it contains at least one of an ion exchange group and a chelate group, and can be appropriately selected according to the purpose, and is a reactive group with the polymer forming the polymer film. Further, it contains other components as required.
The functional compound containing a chelate group may be a functional compound containing a chelate group by reacting a plurality of types of compounds in the addition treatment step.

-Reactive group with polymer-
There is no restriction | limiting in particular as a reactive group with the polymer which forms the said polymer film, According to the objective, it can select suitably. For example, an amino group, a hydroxy group, an epoxy group; derivative groups thereof and the like can be mentioned. Among these, an amino group and a hydroxy group are preferable.

  Specific examples of the functional compound having a reactive group include a reactive group that is an amino group, pentaethylenehexamine, aminoethanesulfonic acid, phosphorylethanolamine, etc .; a reactive group that is a hydroxy group; Acetic acid, choline, hydroxypropanesulfonic acid, disodium glycerophosphate pentahydrate and the like; and others include cyclic compounds such as ethylene sulfide and oxetane compounds.

The functional compound can be added to the polymer film by reacting with a reactive group present in the side chain of the polymer forming the polymer film. Thereby, the functional compound is fixed to the surface of the support for carbon dioxide separation membrane.
As a method of reacting the functional compound with the reactive group present in the side chain of the polymer, a conventionally known method may be used, and for example, the reaction may be performed by heat treatment, energy ray irradiation, or the like.

  The fact that the functional compound is fixed to the surface of the support for carbon dioxide separation membrane can be confirmed by, for example, a back titration method described in JP-A-2005-131482.

  An annealing treatment may be performed after the polymerization step and the addition treatment step. By annealing treatment, the degree of cure of the polymer film can be increased, the solvent in the coating composition can be removed, and the adhesion between the polymer film and the porous substrate can be improved. The annealing temperature is preferably 80 to 200 ° C. The annealing time is, for example, 1 minute to 180 minutes.

<Method for producing carbon dioxide separation membrane>
The method for producing a carbon dioxide separation membrane of the present invention comprises:
While using the support for carbon dioxide separation membrane of the present invention or the support for carbon dioxide separation membrane produced by the method for producing the support for carbon dioxide separation membrane of the present invention,
An application step of applying a composition containing a water-soluble polymer and a carbon dioxide carrier to the surface of the support having the polymer film to obtain a coating film;
A cooling step of cooling the coating film to obtain a gel film;
A drying step of drying the gel film to form a dry film.
The method for producing a carbon dioxide separation membrane of the present invention may further include a crosslinking step for crosslinking the dry membrane.

(Coating process)
The coating step is a step of providing a coating film by preparing a composition containing a water-soluble polymer and a carbon dioxide carrier and then coating the composition on the surface of the support having the polymer film.
In addition to the water-soluble polymer and the carbon dioxide carrier, the composition contains a crosslinking agent, a surfactant, a catalyst, a moisturizing (water absorbing) agent, an auxiliary solvent, a film strength adjusting agent, a defect detecting agent, a film forming suitability imparting agent, and the like. May be included. The water-soluble polymer and carbon dioxide carrier in the production method of the present invention are synonymous with the water-soluble polymer and carbon dioxide carrier in the carbon dioxide separation membrane described above, and preferred embodiments are also the same.

[Crosslinking agent]
When the water-soluble polymer has a crosslinkable group, the polymers can be crosslinked by a conventionally known method such as thermal crosslinking, ultraviolet crosslinking, electron beam crosslinking, radiation crosslinking, or photocrosslinking. In this case, it is preferable that the composition contains a crosslinking agent. Examples of the crosslinking agent include epoxy compounds, polyvalent glycidyl ethers, polyhydric alcohols, polyvalent isocyanates, polyvalent aziridines, haloepoxy compounds, polyvalent aldehydes, and polyvalent amines.

Examples of commercially available epoxy compounds include Epolite 100MF (trimethylolpropane triglycidyl ether) manufactured by Kyoeisha Chemical Co., Ltd., EX-411, EX-313, EX-614B, EX-810 and EX-811 manufactured by Nagase ChemteX Corporation. EX-821, EX-830, NOF Corporation Epiol E400, and the like.
Examples of the polyvalent glycidyl ether include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerol polyglycidyl ether, diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitol polyglycidyl ether, pentaerythritol polyglycidyl ether, Examples include propylene glycol glycidyl ether and polypropylene glycol diglycidyl ether.
Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, glycerin, polyglycerin, propylene glycol, diethanolamine, triethanolamine, polyoxypropyl, and oxyethyleneoxypropylene block. Examples thereof include polymers, pentaerythritol, and sobitol.
Examples of the polyvalent isocyanate include 2,4-toluylene diisocyanate and hexamethylene diisocyanate. Examples of the polyvalent aziridine include 2,2-bishydroxymethylbutanol-tris [3- (1-acylidinyl) propionate], 1,6-hexamethylenediethyleneurea, diphenylmethane-bis-4,4′-. N, N′-diethylene urea and the like can be mentioned.
Examples of the haloepoxy compound include epichlorohydrin and α-methylchlorohydrin.
Examples of the polyvalent aldehyde include glutaraldehyde and glyoxal.
Examples of the polyvalent amine include ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, and polyethyleneimine.

  Of the above-mentioned crosslinking agents, epoxy compounds and glutaraldehyde are particularly preferred from the viewpoint that they have good reactivity with high molecular weight polyvinyl alcohol and the like and can be bonded with excellent hydrolysis resistance.

  The content of the water-soluble polymer in the composition depends on the type, but from the viewpoint of forming a membrane as a binder and allowing the carbon dioxide separation membrane to sufficiently retain moisture, 0.5% by mass to It is preferably 50% by mass, more preferably 1% by mass to 30% by mass, and particularly preferably 2% by mass to 15% by mass.

  The content of the carbon dioxide carrier in the composition is preferably 0.1% by mass to 30% by mass, and more preferably 0.2% by mass to 20% by mass, although it depends on the ratio to the functional monomer amount. %, More preferably 0.3% by mass to 15% by mass. If the content is less than 0.1% by mass, sufficient carbon dioxide carrier ability may not be obtained, and if it exceeds 30% by mass, the carbon dioxide carrier may be salted out in the composition. There is sex.

[Film-forming suitability imparting agent]
The composition may contain a set agent, a viscosity adjuster, a thixotropic adjuster, and the like in order to impart film forming stability during coating.
A polysaccharide is preferred as the set agent. Agar is most preferable from the viewpoints of film-forming properties, availability, cost, film strength, etc., and commercially available products include Ina Agar UP-37, UM-11S, SY-8, ZY-4, ZY-6 (and above, Ina Foods Co., Ltd.), Agarose H, Agarose S (above, Nippon Gene Co., Ltd.) and the like.
As the viscosity modifier, a water-soluble thickener is preferable, and an artificial synthetic system is most preferable. Examples of the water-soluble artificial synthetic thickener include vinyl compounds, vinylidene compounds, polyvinyl alcohol compounds, polyether compounds, and the like.
The thixotropic modifier is preferably water-soluble, more preferably a water-soluble natural synthetic thickener, such as synthetic mica and carboxyvinyl polymer.
These film-forming suitability imparting agents may be used alone or in combination. Among these, those that increase the gelling ability by mixing are known, and can be used by mixing in order to adjust the gelation speed, gelation ability, and gelation temperature.

  The temperature of the composition in the coating process may be determined so that gelation or salting-out does not occur depending on the composition or concentration. However, if the temperature is too high, a large amount of solvent evaporates from the composition and the composition concentration changes. Or about 10 ° C. or less, preferably from room temperature to the boiling point of the solvent, and more preferably from room temperature to 15 ° C. or less of the solvent boiling point. Furthermore, the room temperature to the solvent boiling point of 20 ° C. or lower is most preferable.

  As a method for applying the composition, a conventionally known method can be employed. Examples include curtain flow coaters, extrusion die coaters, air doctor coaters, blade coaters, rod coaters, knife coaters, squeeze coaters, reverse roll coaters, and bar coaters. In particular, an extrusion die coater is preferable from the viewpoint of film thickness uniformity, coating amount, and the like.

The coating amount of the composition depends on the composition and concentration of the composition, but if the coating amount per unit area is too small, pores are formed in the membrane in the cooling step or drying step, or as a carbon dioxide separation membrane. The strength may be insufficient. On the other hand, if the coating amount is too large, the variation in the film thickness may increase, or the film thickness of the obtained carbon dioxide separation membrane may become too large, resulting in a decrease in carbon dioxide permeability.
From these viewpoints, the thickness of the gel membrane obtained in the cooling step is 10 μm or more, more preferably 50 μm or more, particularly preferably 100 μm or more, and the thickness of the carbon dioxide separation membrane obtained in the crosslinking step is 5 μm or more. The coating amount is preferably adjusted so that it is preferably 10 μm or more, and particularly preferably 15 μm or more.

(Cooling process)
A cooling process is a process of cooling the coating film obtained on the support body, and obtaining a gel film. By cooling the support on which the coating film is formed, the coating film is gelled (fixed), and a stable gel film is obtained.

  If the cooling temperature in the cooling step is too high, immobilization may take time and the film thickness uniformity may decrease, and if it is too low, the gel film may freeze and the film quality may change. The coating temperature can be determined according to the composition and concentration of the coating film so that a gel film with substantially the same thickness as the coating film can be obtained, but the cooling temperature in the cooling process is a gel that rapidly gels the coating film on the support. From the viewpoint of forming a film, the wet bulb temperature is preferably 1 to 35 ° C, more preferably 2 to 20 ° C, and particularly preferably 5 to 15 ° C.

(Drying process)
After the cooling step, the gel film is dried to form a dry film. The dry membrane functions as a carbon dioxide separation layer.
Although there is no particular limitation on the drying method, for example, the gel film on the support is dried by applying hot air. Since the film after the cooling step is fixed in a gel state, it is dried without collapsing even when it is exposed to a drying wind.
The wind speed is such that the gel film can be dried quickly and the gel film does not collapse, for example, preferably 1 m / min to 80 m / min, more preferably 2 m / min to 70 m / min, and 3 m / min to 40 m / min. Is particularly preferred.
The temperature of the wind is preferably 1 to 80 ° C., more preferably 2 to 70 ° C., more preferably 3 to 60 ° C. so that the deformation of the support does not occur and the gel membrane can be dried quickly. Is particularly preferred.

(Crosslinking process)
The crosslinking step may be performed simultaneously with the drying step or may be performed independently. Moreover, a well-known crosslinking method can be used for the crosslinking method. For example, after drying by applying warm air to the gel film, it may be crosslinked by heating means such as an infrared heater, or may be crosslinked together with drying by warm air. Thermal crosslinking can be performed by heating to about 100 to 150 ° C., for example. After coating, the gel film may be subjected to UV or electron beam crosslinking and then dried.

<CO2 separation device>
The carbon dioxide separator includes the carbon dioxide separation membrane of the present invention. The carbon dioxide separation membrane may be installed as a flat membrane, or may be used after being processed into a spiral type or a pleated type known as a reverse osmosis membrane module.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

<Example 1> Production of carbon dioxide separation membrane (1) [Production of composition for gel membrane formation]
5 g of polyvinyl alcohol-polyacrylate copolymer (sodium salt) aqueous solution (Kuraray Co., Ltd., Clastomer AP20) 50 g, epoxy crosslinking agent (EX-810, NOF Corporation) 0.7 g and agar 0.5 g Were mixed with pure water to make an 85 g aqueous solution and stirred at 95 ° C. for 60 minutes. Then, the composition (1) for gel film formation was produced by dripping 15g of 40 mass% cesium carbonate aqueous solution.

[Production of support]
Hydrophobic polytetrafluoroethylene of 10 cm × 10 cm in 100 ml of methanol / MEK mixed solution containing 5% by mass acrylic acid (manufactured by TCI) and 0.1% by mass Irgacure 907 (manufactured by BASF) as a photo radical polymerization initiator A membrane (supported PTFE, Tetolatex 7008 manufactured by Nakao Filter Co., Ltd.) (hereinafter “hydrophobic s-PTFE membrane”) was immersed. The pulled up film was irradiated with UV, and then annealed at 150 ° C. for 10 minutes under atmospheric pressure to prepare a support (1).
In the support (1), the polymer coating has at least a carboxy group derived from acrylic acid as a hydrophilic group.

[Coating of Gel Film Forming Composition on Support]
The gel film-forming composition (1) was applied onto one side of the support (1) (the side up during UV irradiation and annealing. The same applies to Examples 2 to 11), cooled and dried. Thus, a carbon dioxide separation membrane (1) was produced.

<Example 2> Preparation of carbon dioxide separation membrane (2) [Preparation of composition for gel film formation]
Instead of the 5% by mass polyvinyl alcohol-polyacrylate copolymer (sodium salt) aqueous solution in Example 1, a 5% by mass polyvinyl alcohol (molecular weight 180,000, saponification rate 99%, manufactured by Aldrich) aqueous solution was used. Prepared a gel film-forming composition (2) in the same manner as in Example 1.

[Production of support]
A support (2) was produced in the same manner as in Example 1.
In the support (2), the polymer coating has at least a carboxy group derived from acrylic acid as a hydrophilic group.

[Coating of Gel Film Forming Composition on Support]
The carbon dioxide separation membrane (2) was produced by applying the gel membrane-forming composition (2) onto one side of the support (2), cooling and drying.

<Example 3> Production of carbon dioxide separation membrane (3) [Production of composition for gel membrane formation]
A gel film-forming composition (3) was prepared in the same manner as in Example 1 except that 3 g of 40 mass% potassium carbonate aqueous solution and 1.2 g of glycine were used instead of the 40 mass% cesium carbonate aqueous solution in Example 1. .

[Production of support]
A support (3) was produced in the same manner as in Example 1.
In the support (3), the polymer coating has at least a carboxy group derived from acrylic acid as a hydrophilic group.

[Coating of Gel Film Forming Composition on Support]
The composition for gel film formation (3) was applied onto one side of the support (3), cooled and dried to prepare a carbon dioxide separation membrane (3).

<Example 4> Production of carbon dioxide separation membrane (4) [Production of composition for gel membrane formation]
A gel film forming composition (4) was prepared in the same manner as in Example 1.

[Production of support]
90 parts by mass of 2-acrylamido-2-methylpropanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 10 parts by mass of N, N′-methylenebisacrylamide (manufactured by Tokyo Chemical Industry Co., Ltd.), and an ultraviolet polymerization initiator (Ciba Specialty Chemical Co., Ltd.) A solution was prepared by dissolving 2 g of a mixture with 2 parts by mass of Darocur 1173) in 100 ml of water, and a 10 cm × 10 cm hydrophobic s-PTFE membrane was immersed therein. The pulled up film was irradiated with UV, and then annealed at 150 ° C. for 10 minutes under atmospheric pressure to prepare a support (4).
In the support (4), the polymer coating has at least sulfonic acid groups derived from 2-acrylamido-2-methylpropanesulfonic acid as hydrophilic groups.

[Coating of Gel Film Forming Composition on Support]
The composition for gel film formation (4) was applied onto one side of the support (4), cooled and then dried to prepare a carbon dioxide separation membrane (4).

<Example 5> Preparation of carbon dioxide separation membrane (5) [Preparation of composition for forming gel membrane]
A gel film-forming composition (5) was prepared in the same manner as in Example 1.

[Production of support]
Support (5) in the same manner as in Example 1, except that 5% by mass of 2-hydroxyethyl methacrylate phosphate ester (Phosmer M manufactured by Unichemical Co., Ltd.) was used instead of 5% by mass of acrylic acid in Example 1. Was made.
In the support (5), the polymer coating has at least a phosphate group derived from 2-hydroxyethyl methacrylate phosphate as a hydrophilic group.

[Coating of Gel Film Forming Composition on Support]
The composition for gel film formation (5) was applied onto one side of the support (5), cooled and then dried to prepare a carbon dioxide separation membrane (5).

<Example 6> Production of carbon dioxide separation membrane (6) [Production of composition for gel membrane formation]
A gel film forming composition (6) was prepared in the same manner as in Example 1.

[Production of support]
A support (6) was produced in the same manner as in Example 1 except that 5% by mass of 2-hydroxyethyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd.) was used instead of 5% by mass of acrylic acid in Example 1.
In the support (6), the polymer coating has at least a hydroxy group derived from 2-hydroxyethyl acrylate as a hydrophilic group.

[Coating of Gel Film Forming Composition on Support]
The composition for gel film formation (6) was applied onto one side of the support (6), cooled and dried to prepare a carbon dioxide separation membrane (6).

<Example 7> Production of carbon dioxide separation membrane (7) [Production of composition for forming gel membrane]
A gel film forming composition (7) was prepared in the same manner as in Example 1.

[Production of support]
5% by mass 4-hydroxybutyl acrylate glycidyl ether (manufactured by Nippon Kasei Co., Ltd.) as glycidyl acrylates and 5% by mass N- (2-hydroxyethyl) ethylenediaminetriacetic acid (manufactured by Dojin Chemical Co., Ltd.) as a functional compound having a chelate group Then, 10 cm × 10 cm of hydrophobic s-PTFE was immersed in 100 ml of a methanol / MEK mixed solution containing 0.1 mass% Irgacure 907 (manufactured by BASF) as a photo radical polymerization initiator. The pulled up film was irradiated with UV, and then annealed at 150 ° C. for 10 minutes under atmospheric pressure. Then, the support body (7) was produced by immersing in methanol for 30 minutes, washing | cleaning, and making it dry.
In the support (7), the polymer coating has at least a hydroxy group derived from 4-hydroxybutyl acrylate glycidyl ether as a hydrophilic group.

[Coating of Gel Film Forming Composition on Support]
The composition for gel film formation (7) was applied onto one side of the support (7), cooled and dried to prepare a carbon dioxide separation membrane (7).

<Example 8> Production of carbon dioxide separation membrane (8) [Production of composition for gel membrane formation]
A gel film forming composition (8) was prepared in the same manner as in Example 1.

[Production of support]
Hydrophobic s-PTFE of 10 cm × 10 cm was added to 100 ml of a methanol / MEK mixed solution containing 5% by mass acrylic acid (manufactured by TCI) and 0.1% by mass Irgacure 907 (manufactured by BASF) as a photo radical polymerization initiator. The film immersed and pulled was irradiated with UV. Subsequently, the film was immersed in thionyl chloride, and then immersed in a methanol solution of 5 mass% pentaethylenehexamine, and the film pulled up was subjected to an annealing treatment at 150 ° C. for 10 minutes under atmospheric pressure. Subsequently, the film was dipped in a 10% by mass aminotrimethylenephosphonic acid (manufactured by Nagase ChemteX Corporation) / toluene solution and subjected to annealing treatment at 100 ° C. for 10 minutes under atmospheric pressure. Thereafter, the substrate (8) was produced by immersing in methanol for 30 minutes for washing and drying.
The reaction compound of aminotrimethylene phosphonic acid and pentaethylenehexamine is a functional compound having a chelate group.
In the support (8), the polymer film has at least a carboxy group derived from acrylic acid as a hydrophilic group.

[Coating of Gel Film Forming Composition on Support]
The composition for gel film formation (8) was applied onto one side of the support (8), cooled and then dried to prepare a carbon dioxide separation membrane (8).

<Example 9> Preparation of carbon dioxide separation membrane (9) [Preparation of composition for gel film formation]
A gel film forming composition (9) was prepared in the same manner as in Example 1.

[Production of support]
A support (9) was produced in the same manner as in Example 8, except that 5% by mass of 3-hydroxypropanesulfonic acid (manufactured by TCI) was used in place of 10% by mass of aminotonomimethylenephosphonic acid in Example 8. .
The 3-hydroxypropanesulfonic acid is a functional compound having a hydroxy group as an ion exchange group.
In the support (9), the polymer coating has at least a carboxy group derived from acrylic acid and a hydroxy group derived from 3-hydroxypropanesulfonic acid as hydrophilic groups.

[Coating of Gel Film Forming Composition on Support]
The composition for forming a gel film (9) was applied onto one side of the support (9), cooled and then dried to prepare a carbon dioxide separation membrane (9).

<Example 10> Preparation of carbon dioxide separation membrane (10) [Preparation of composition for gel film formation]
A gel film forming composition (10) was prepared in the same manner as in Example 1.

[Production of support]
A support (10) was produced in the same manner as in Example 1 except that 1% by mass acrylic acid (manufactured by TCI) was used instead of 5% by mass acrylic acid in Example 1.
In the support (10), the polymer coating has at least a carboxy group derived from acrylic acid as a hydrophilic group.

[Coating of Gel Film Forming Composition on Support]
The composition for gel film formation (10) was applied onto one side of the support (10), cooled and then dried to prepare a carbon dioxide separation membrane (10).

<Example 11> Production of carbon dioxide separation membrane (11) [Production of composition for gel membrane formation]
A gel film-forming composition (11) was produced in the same manner as in Example 1.

[Production of support]
A support (11) was produced in the same manner as in Example 1 except that 20% by mass acrylic acid (manufactured by TCI) was used instead of 5% by mass acrylic acid in Example 1.
In the support (11), the polymer coating has at least a carboxy group derived from acrylic acid as a hydrophilic group.

[Coating of Gel Film Forming Composition on Support]
The carbon dioxide separation membrane (11) was produced by applying the gel membrane-forming composition (11) onto one side of the support (11), cooling and drying.

<Comparative Example 1> Preparation of carbon dioxide separation membrane (12) [Preparation of composition for gel film formation]
A gel film forming composition (12) was prepared in the same manner as in Example 1.

[Coating of Gel Film Forming Composition on Support]
The composition for gel film formation (12) was applied onto one side of 10 cm × 10 cm untreated hydrophobic s-PTFE, cooled and dried to prepare a carbon dioxide separation membrane (12).

<Comparative Example 2> Preparation of carbon dioxide separation membrane (13) [Preparation of composition for gel film formation]
A gel film-forming composition (13) was produced in the same manner as in Example 1.

[Coating of Gel Film Forming Composition on Support]
The composition for forming a gel film (13) was applied onto one side of 10 cm × 10 cm untreated hydrophilic s-PTFE (manufactured by Nakao Filter Co., Ltd.), cooled and dried to obtain a carbon dioxide separation membrane (13 ) Was produced.

<Comparative Example 3> Production of carbon dioxide separation membrane (14) [Production of composition for gel membrane formation]
A gel film-forming composition (14) was produced in the same manner as in Example 1.

[Production of support]
A 10 cm × 10 cm hydrophobic s-PTFE was dipped in a methanol solution of 5 mass% pentaethylenehexamine, and the pulled film was annealed at 150 ° C. for 10 minutes under atmospheric pressure. Subsequently, the film was immersed in a 10% by mass aminotrimethylene phosphonic acid (manufactured by Nagase ChemteX) / toluene solution and subjected to an annealing treatment at 100 ° C. for 10 minutes under atmospheric pressure. Then, the support body (14) was produced by immersing in methanol for 30 minutes, washing | cleaning, and making it dry.
The reaction compound of aminotrimethylene phosphonic acid and pentaethylenehexamine is a functional compound having a chelate group.

[Coating of Gel Film Forming Composition on Support]
The gel film-forming composition (14) is applied onto one side of the support (14) (the side up during the annealing process; the same applies to Comparative Example 4), and after cooling, the carbon dioxide is dried. A separation membrane (14) was produced.

<Comparative Example 4> Preparation of carbon dioxide separation membrane (15) [Preparation of composition for gel film formation]
A gel film-forming composition (15) was produced in the same manner as in Example 1.

[Production of support]
A support (15) was produced in the same manner as in Comparative Example 3, except that 5% by mass of 3-hydroxypropanesulfonic acid (manufactured by TCI) was used instead of 10% by mass of amitonolimethylenephosphonic acid in Comparative Example 3. .
The 3-hydroxypropanesulfonic acid is a functional compound having a hydroxy group as an ion exchange group.

[Coating of Gel Film Forming Composition on Support]
The composition for forming a gel film (15) was applied onto one side of the support (15), cooled and dried to prepare a carbon dioxide separation membrane (15).

<Comparative Example 5> Production of carbon dioxide separation membrane (16) [Production of composition for gel membrane formation]
A gel film-forming composition (16) was produced in the same manner as in Example 1.

[Production of support]
A 10 cm × 10 cm hydrophobic s-PTFE membrane was subjected to corona discharge treatment for 15 seconds by applying a voltage of 30 kV using a corona discharge treatment apparatus (model “HFSS-103” manufactured by Kasuga Denki Co., Ltd.). (16) was produced.

[Coating of Gel Film Forming Composition on Support]
The composition for forming a gel film (16) was applied onto one side (surface subjected to corona discharge treatment) of the support (16), cooled and dried to prepare a carbon dioxide separation membrane (16).

<Comparative Example 6> Preparation of carbon dioxide separation membrane (17) [Preparation of composition for gel film formation]
A gel film-forming composition (17) was produced in the same manner as in Example 1.

[Production of support]
Plasma treatment is performed on a 10 cm × 10 cm hydrophobic s-PTFE membrane using an atmospheric pressure plasma generator (manufactured by Pearl Industrial Co., Ltd.) under conditions of an output voltage of 24 kV, a pulse frequency of 60 Hz, an Ar gas flow rate of 100 L / min, and an irradiation distance of 10 mm. To prepare a support (17).

[Coating of Gel Film Forming Composition on Support]
The composition for forming a gel film (17) was applied onto one side (surface subjected to plasma treatment) of the support (17), cooled and dried to prepare a carbon dioxide separation membrane (17).

<Comparative Example 7> Production of carbon dioxide separation membrane (18) [Production of composition for gel membrane formation]
Instead of the 5 mass% polyvinyl alcohol-polyacrylate copolymer (sodium salt) aqueous solution in Example 1, a 5 mass% polyacrylic acid aqueous solution was used, and instead of the 40 mass% cesium carbonate aqueous solution, 50 mass% tri A gel film-forming composition (18) was produced in the same manner as in Example 1 except that an ethanolamine aqueous solution was used.

[Production of support]
In place of the hydrophobic s-PTFE membrane in Comparative Example 6, a plasma treatment was performed in the same manner as in Comparative Example 6 except that a polypropylene porous membrane (manufactured by Daicel Chemical Industries, Ltd., Cellguard 2500) was used. 18) was produced.

[Coating of Gel Film Forming Composition on Support]
The composition for forming a gel film (18) was applied onto one side (surface subjected to plasma treatment) of the support (18), cooled and then dried to prepare a carbon dioxide separation membrane (18).

<Evaluation>
The following seven items were evaluated. The results are shown in Table 1.
In Table 1, PVA / PAA means polyvinyl alcohol-polyacrylate copolymer, PVA means polyvinyl alcohol, PAA means polyacrylic acid, PTFE means polytetrafluoroethylene. Meaning, PP means polypropylene.

(Polymer film thickness)
In Examples 1 to 11, the film thickness of the polymer coating formed on the surface of the hydrophobic s-PTFE membrane (distance from the outermost surface to the hydrophobic porous substrate) was measured by secondary ion mass spectrometry, It was classified into the following three stages.
# 1: Film thickness is 1 μm or less # 2: Film thickness is 100 nm or less # 3: Film thickness is more than 1 μm

(Membrane pH of the support)
About the support body produced in Examples 1-11 and Comparative Examples 3-7, and the PTFE film | membrane used by Comparative Examples 1 and 2, membrane surface pH was evaluated as follows.
Under the condition of 25 ° C., a small amount of pure water was dropped on the surface on which the surface treatment was performed (the side on which the composition for forming a gel film was applied), and a planar pH electrode was applied to the surface to measure the film surface pH. The pure water used here is ion-exchanged water or distilled water having a pH of 5 to 8 itself and an electrical conductivity at 25 ° C. of 1 μs / cm or less. The measured film surface pH was classified into the following three stages.
A: membrane surface pH is acidic (membrane surface pH is less than 6.5)
B: membrane surface pH is neutral (membrane surface pH is 6.5 or more and less than 7.5)
C: membrane surface pH is basic (membrane surface pH is 7.5 or more)

(Contact angle of support)
About the support body produced in Examples 1-11 and Comparative Examples 3-7, and the PTFE film | membrane used in Comparative Examples 1 and 2, the contact angle with water was evaluated as follows.
Under the conditions of 25 ° C. and 50% RH, the contact angle between the surface of the surface-treated side (the side on which the gel film-forming composition is applied) and water was measured using a fully automatic contact angle meter (manufactured by Kyowa Interface Chemical Co., DM-701). The same test was performed three times, the average was calculated, and evaluated according to the following three criteria.
◎: Contact angle is less than 90 degrees ○: Contact angle is 90 degrees or more and less than 120 degrees ×: Contact angle is 120 degrees or more ◎ If ◎ and ○, the hydrophilicity of the support surface is judged good. The hydrophilicity of the body surface was judged to be poor.

(Adhesion)
The carbon dioxide separation membranes produced in Examples 1 to 11 and Comparative Examples 1 to 7 were conditioned for 2 hours under the conditions of 25 ° C. and 60% RH. On the surface of each film, 11 vertical and 11 horizontal cuts are made in a grid pattern with a cutter knife, and a total of 100 square squares are engraved, and a polyester adhesive tape (manufactured by Nitto Denko Corporation) No. 31B) was pasted. After 30 minutes, the tape was quickly peeled off in the vertical direction, and the number of peeled squares was counted. The same test was performed three times, the average was calculated, and evaluated according to the following three criteria.
A: No peeling was observed at 100 mm.
○: peeling of 1 to 10 mm was observed at 100 mm. (Tolerance)
X: Peeling of 11 mm or more was observed at 100 mm.
In the case of (double-circle) and (circle), it was judged that the adhesiveness of a support body and a carbon dioxide separation layer was favorable, and in the case of x, it was judged that the adhesiveness of a support body and a carbon dioxide separation layer was unsatisfactory.

(Gas permeability)
About the carbon dioxide separation membrane produced in Examples 1-11 and Comparative Examples 1-7, the permeability | transmittance of the carbon dioxide gas was evaluated as follows.
A carbon dioxide separation membrane was cut to a diameter of 47 mm and sandwiched between PTFE membrane filters to prepare a gas permeation test sample. As a test gas, a mixed gas of CO ₂ / H ₂ : 10/90 (volume ratio) was used for each sample (effective area 2.40 cm ² ) at a relative humidity of 70%, a flow rate of 100 ml / min, a temperature of 130 ° C., and a total pressure of 3 atm. Then, Ar gas (flow rate 90 ml / min) was allowed to flow on the permeate side. The permeated gas was analyzed with a gas chromatograph, and the CO ₂ permeation rate and the separation factor were calculated. The CO ₂ permeability coefficient [Q (CO ₂ )] was determined and evaluated according to the following four criteria. Here, the permeation flow rate unit (GPU) is 1 × 10 ⁻⁵ cm ³ (STP) / (s · cm ² · cmHg).
A: Initial Q (CO ₂ ) is more than 250 ○: Initial Q (CO ₂ ) is more than 200 by GPU Δ: Initial Q (CO ₂ ) is GPU by 150 or more and less than 200 ×: Initial Q (CO ₂ ) Is less than 150 in GPU. Δ or more is a practically acceptable level.
In Comparative Example 2 using hydrophilic s-PTFE as the support, the carbon dioxide separation layer penetrates into the support during the supply of the high-temperature and high-pressure test gas, and thus measurement itself is impossible. It was.

(durability)
In the gas permeation test, the permeation coefficient after continuous use for 500 hours was determined. And the fluctuation rate of the transmission coefficient was calculated | required with the following formula, and durability (maintenance of the separation performance when it continued using) was evaluated by the following three-stage criteria.
Percentage variation (%) of transmission coefficient = {(initial transmission coefficient) − (transmission coefficient after 500 hours)} / (initial transmission coefficient) × 100
◎: Permeability coefficient fluctuation rate is 5% or less ○: Permeability coefficient fluctuation rate is more than 5% and 10% or less ×: Permeability coefficient fluctuation rate is more than 10% In the case of x, it was judged that the durability was poor.
In Comparative Example 2 using hydrophilic s-PTFE as a support, it was impossible to measure itself as described above.

(Inhibition of carbon dioxide carrier exudation to support)
The wet heat test was performed for the carbon dioxide separation membrane produced in Examples 1-11 and Comparative Examples 1-7 on conditions of 130 degreeC and 85% RH for 500 hours. The sample piece after the wet heat test was frozen, and an ultrathin section prepared with an ultramicrotome was observed by transmission electron microscopy and energy dispersive X-ray spectroscopy. At that time, evaluation was performed based on the presence or absence of a carrier ion signal from the support. In addition, this evaluation was evaluated from the viewpoint of how it has a bleeding suppression effect.
A: No signal derived from carrier ions was detected in the support. (With suppression effect)
A: A signal derived from carrier ions was slightly detected in the support. (With suppression effect)
X: Almost no carrier ions were present on the support, and a signal derived from carrier ions was detected only from within the support. (No suppression effect)
The above is a practically preferable level.

  As shown in Table 1, the carbon dioxide separation membranes of Examples 1 to 11 according to the present invention were excellent in carbon dioxide gas permeability, and the separation performance was maintained high even if the use was continued. Therefore, it was confirmed that the carbon dioxide separation membrane of the present invention is excellent in carbon dioxide separation performance and has a long life.

<Example 12>
[modularization]
Using the carbon dioxide separation membrane produced in Example 1, a spiral type module was produced with reference to JP-A-5-168869. It was confirmed that the produced carbon dioxide separation module had a long lifetime according to the performance of the mounted carbon dioxide separation membrane.

Claims (13)

A carbon dioxide separation layer comprising a water-soluble polymer and a carbon dioxide carrier;
A hydrophobic porous substrate, and a polymer film having a hydrophilic group provided on at least one surface of the porous substrate, in contact with the carbon dioxide separation layer via the polymer film, A porous support for supporting the carbon dioxide separation layer;
A carbon dioxide separation membrane.   The carbon dioxide separation membrane according to claim 1, wherein the polymer coating has at least one of an ion exchange group and a chelate group.   The carbon dioxide separation membrane according to claim 1 or 2, wherein the polymer coating has a thickness of 1 µm or less.   The said polymer film has at least 1 sort (s) of a carboxy group, a sulfonic acid group, a phosphoric acid group, a hydroxyl group, an amino group, an epoxy group, an acrylamide group, an isocyanate group, and an acid chloride group as a hydrophilic group. The carbon dioxide separation membrane according to any one of claims 3 to 4.   The porous substrate includes at least one of polytetrafluoroethylene, polyethersulfone, polyphenylene sulfide, polysulfone, polypropylene, polyetherimide, polyetheretherketone, and polyvinylidene fluoride. The carbon dioxide separation membrane of any one of Claims 1. A hydrophobic porous substrate;
A polymer coating having a hydrophilic group present as an outermost layer on at least one surface of the porous substrate;
A support for carbon dioxide separation membrane comprising:   The carbon dioxide separation membrane support according to claim 6, wherein a contact angle between the surface of the polymer coating and water is less than 120 degrees.   The support for a carbon dioxide separation membrane according to claim 6 or 7, wherein the polymer film has at least one of an ion exchange group and a chelate group. An application step of applying a polymerizable composition containing a radical polymerizable monomer to at least one surface of a hydrophobic porous substrate;
A polymerization step of irradiating the applied polymerizable composition with active energy rays to form a polymer film;
The manufacturing method of the support body for carbon dioxide separation membrane which has this.   The method for producing a support for a carbon dioxide separation membrane according to claim 9, further comprising an addition treatment step of adding at least one of an ion exchange group and a chelate group to the polymer coating.   The method for producing a support for a carbon dioxide separation membrane according to claim 9 or 10, wherein the radical polymerizable monomer contains at least one of acrylate, methacrylate, acrylamide, acrylic acid and derivatives thereof. The carbon dioxide separation membrane support according to any one of claims 6 to 8, or the method for producing a carbon dioxide separation membrane support according to any one of claims 9 to 11. While using the produced support for carbon dioxide separation membrane,
An application step of applying a composition containing a water-soluble polymer and a carbon dioxide carrier to the surface of the support having the polymer film to obtain a coating film;
A cooling step of cooling the coating film to obtain a gel film;
A drying step of drying the gel film to form a dry film;
A method for producing a carbon dioxide separation membrane having   The method for producing a carbon dioxide separation membrane according to claim 12, further comprising a crosslinking step of crosslinking the dry membrane.