JP6159624B2 - Method for producing acid gas separation membrane - Google Patents

Description

  The present invention relates to a method for producing an acidic gas separation membrane that selectively separates acidic gas from raw material gas. Specifically, the present invention relates to a method for producing an acid gas separation membrane capable of appropriately forming a facilitated transport membrane on the facilitated transport membrane in an acidic gas separation membrane having a multilayer facilitated transport membrane.

  In recent years, development of technology for selectively separating an acid gas from a source gas (a gas to be treated) has been advanced. For example, an acid gas separation membrane that separates an acid gas from a raw material gas using an acid gas separation membrane that selectively permeates the acid gas has been developed.

As an example, Patent Literature 1 includes a carbon dioxide carrier on a carbon dioxide permeable support as an acidic gas separation membrane (carbon dioxide separation gel membrane) for separating carbon dioxide (carbon dioxide) from a raw material gas. An acidic gas separation membrane is disclosed in which a hydrogel membrane formed by absorbing an aqueous solution into a vinyl alcohol-acrylate copolymer having a crosslinked structure is formed.
Patent Document 1 discloses, as a method for producing this acidic gas separation membrane, an uncrosslinked vinyl alcohol-acrylate copolymer aqueous solution is applied in a film form on a carbon dioxide permeable support, A method is also disclosed in which an aqueous solution is heated and cross-linked to insolubilize water, and the water-insolubilized material absorbs an aqueous carbon dioxide carrier solution to form a gel.

  On the other hand, in Patent Document 2, a coating composition (coating solution) containing a water-absorbing polymer, a carbon dioxide carrier, and a gelling agent and prepared at 50 ° C. or higher is applied to a support. An apparatus for producing an acidic gas separation membrane is described in which the coating film formed in the above is cooled to 12 ° C. or less to form a gel membrane, and this gel membrane is dried with warm air to form a carbon dioxide separation membrane.

  The acidic gas separation membrane shown in Patent Literature 1 and Patent Literature 2 is an acidic gas separation membrane using a so-called facilitated transport membrane. The facilitated transport membrane has a carrier that reacts with an acidic gas such as the above-mentioned carbon dioxide carrier in the membrane, and the acidic gas is separated from the source gas by transporting the acidic gas to the opposite side of the membrane by this carrier. .

Japanese Patent Publication No. 7-102310 JP 2012-143711 A

  By the way, in patent document 1, about 1-200 micrometers is assumed for the thickness of a facilitated-transport film | membrane (gel film). On the other hand, in Patent Document 2, it is assumed that a coating composition to be a facilitated transport film is applied at 1 mm or less, and this coated film is gel-dried to form a facilitated transport film having a thickness of about 5 to 50 μm. Yes.

For example, when carbon dioxide is separated from a mixed gas of carbon dioxide and hydrogen, the facilitated transport film actively permeates carbon dioxide by the chemical reaction of the carrier, but at the same time, hydrogen also dissolves and diffuses on the film surface. Through. For this reason, it is advantageous that the facilitated transport film is thicker in terms of lowering the hydrogen permeability.
In addition, when a facilitated transport film is formed by applying a coating composition on a support and drying it, if the coating composition is thin, it will be mixed into foreign matter or coating on the support surface. Due to the bubbles, defects such as pinholes may occur in the formed facilitated transport film.

From such a point of view, there is a demand for forming a thicker facilitated transport film as compared with Patent Documents 1 and 2.
In order to form a thick film by a coating method, it is usual to increase the thickness (coating film thickness) of the coating composition applied to the support. However, the coating composition for forming the facilitated transport film generally has a high water content. Therefore, when a coating composition having a thickness exceeding 3 mm is applied and dried, the drying process on the film surface side and the support side is greatly different. That is, in a coating composition having a thickness exceeding 3 mm, the film surface side is rapidly dried to form a film, and therefore the film surface may have scale-like irregularities and uneven distribution of carriers and the like.
Furthermore, in order to dry a thick coating film, drying time becomes long and it is disadvantageous also in terms of productivity, the size of manufacturing equipment, and the like.

On the other hand, these problems can be solved by forming the facilitated transport film in a plurality of times so as to form a thick facilitated transport film in total.
However, according to the study by the present inventors, when the facilitated transport film is formed by applying the coating composition on the facilitated transport film, the coating of the upper facilitated transport film cannot be properly formed and promoted. The transport film may become uneven.

  The object of the present invention is to solve such problems of the prior art, and by forming the facilitated transport film a plurality of times, it is possible to form the intended thick facilitated transport film, An object of the present invention is to provide a method for producing an acidic gas separation membrane capable of forming a uniform facilitated transport membrane free from membrane defects and the like with all facilitated transport membranes.

In order to achieve this object, the first aspect of the method for producing an acidic gas separation membrane of the present invention includes a carrier that reacts with an acidic gas on the surface of a porous support, and a hydrophilic property for supporting the carrier. An initial film forming step of forming a first facilitated transport film by applying a coating composition containing a compound so that the film thickness is 0.01 to 3 mm and drying the applied coating composition;
A coating composition containing a carrier that reacts with an acidic gas and a hydrophilic compound for supporting the carrier is applied to the surface of the previously formed facilitated transport film, and the applied coating composition is dried and accelerated. Having one or more laminated film forming steps for forming a transport film,
In the laminated film forming step, the temperature and humidity of the space to which the facilitated transport film formed in the previous step is exposed until the coating composition is applied are measured. Provided is a method for producing an acidic gas separation membrane, characterized in that the temperature and humidity of a space are controlled so as to be 10 to 50% RH.

In the first aspect of the method for producing an acidic gas separation membrane of the present invention, the workpiece is sent out from a workpiece roll formed by winding a long workpiece and conveyed in the longitudinal direction. It is preferable to use a roll-to-roll method in which processing is performed and a processed object is wound into a roll shape to form a processed roll.
In addition, the porous support is sent out from a support roll formed by winding the porous support, and the porous support is transported in the longitudinal direction, and the initial film forming process or one or more laminated film forming processes are performed. After that, the processed object to be processed is wound into a roll to form a processed roll, and then the processed object to be processed is sent out from this processed roll to perform a laminated film forming process. When the processed object to be processed is sent out from the roll and the laminated film forming step is performed, the space in which the processed roll for supplying the processed object is present, and the facilitated transport film until the coating composition is applied It is preferable to manage temperature and humidity in the space where the water is exposed.
Further, in the initial film forming step and the laminated film forming step, the temperature and humidity of the space to which the formed facilitated transport film is exposed from the drying of the coating composition to the winding of the processed object to be processed in a roll shape. It is preferable to measure and control the temperature and humidity of the space so that the temperature and humidity are in a predetermined range.
The coating composition preferably has a temperature of 15 to 35 ° C. and a viscosity of 0.1 to 5 Pa · sec.
Moreover, it is preferable that the coating composition in an initial stage film formation process and the coating composition in at least 1 time of laminated film formation process are the same compositions.
Moreover, it is preferable that the coating composition in an initial stage film formation process and the coating composition in at least 1 time of laminated film formation process are different compositions.
Furthermore, it is preferable that the coating composition contains cesium carbonate as a carrier, polyvinyl alcohol-polyacrylic acid copolymer as a hydrophilic compound, and further contains a crosslinking agent.

The second aspect of the method for producing an acidic gas separation membrane of the present invention is a coating composition containing a carrier that reacts with an acidic gas and a hydrophilic compound for supporting the carrier on the surface of the porous support. An initial film forming step of forming an initial facilitated transport film by applying the product so that the film thickness is 0.01 to 3 mm, and drying the applied coating composition;
A coating composition containing a carrier that reacts with an acidic gas and a hydrophilic compound for supporting the carrier is applied to the surface of the previously formed facilitated transport film, and the applied coating composition is dried and accelerated. Having one or more laminated film forming steps for forming a transport film,
In addition, in the laminated film forming step, the acidic gas is characterized in that the coating composition is applied under a condition that the weight increase rate due to water absorption of the facilitated transport film formed in the previous step is 40% by mass or less. A method for producing a separation membrane is provided.

In the second aspect of the method for producing an acidic gas separation membrane of the present invention, the workpiece is sent out from a workpiece roll formed by winding a long workpiece and conveyed in the longitudinal direction. It is preferable to use a roll-to-roll method in which processing is performed and a processed object is wound into a roll shape to form a processed roll.
The coating composition preferably has a temperature of 15 to 35 ° C. and a viscosity of 0.1 to 5 Pa · sec.
Moreover, it is preferable that the coating composition in an initial stage film formation process and the coating composition in at least 1 time of laminated film formation process are the same compositions.
In addition, in the laminated film forming process, by controlling at least one of the temperature and humidity of the space where the facilitated transport film for applying the coating composition is present, the rate of weight increase due to water absorption of the facilitated transport film formed in the previous process It is preferable that the coating composition is applied under the condition that is 40% by mass or less.
The coating composition preferably contains cesium carbonate as a carrier, polyvinyl alcohol-polyacrylic acid copolymer as a hydrophilic compound, and further contains a crosslinking agent.
Furthermore, in the initial film forming step and the laminated film forming step, the temperature and humidity of the space to which the formed facilitated transport film is exposed from the drying of the coating composition to the winding of the processed object to be rolled are changed. It is preferable to measure and control the temperature and humidity of the space so that the temperature and humidity are in a predetermined range.

According to the present invention as described above, when the coating composition to be the facilitated transport film is applied on the previously formed facilitated transport film, the uniform coating composition is formed on the entire surface without causing repelling. A coating film (liquid film) can be formed.
Therefore, according to the present invention, in the production of an acid gas separation membrane, all facilitated transports are formed when forming the facilitated transport film of the target thick film by forming the facilitated transport film several times by overlapping and forming the facilitated transport film. A uniform facilitated transport film having no film defects or the like can be formed.

It is a figure which shows notionally an example of the manufacturing apparatus which enforces the manufacturing method of the acidic gas separation membrane of this invention. It is a figure which shows notionally an example of the acidic gas separation membrane created with the manufacturing method of the acidic gas separation membrane of this invention of this invention. It is a figure which shows notionally another example of the manufacturing apparatus which enforces the manufacturing method of the acidic gas separation membrane of this invention.

  Hereinafter, the method for producing an acidic gas separation membrane of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

  In FIG. 1, an example of the manufacturing apparatus of the acidic gas separation membrane which implements the manufacturing method of the acidic gas separation membrane of this invention is shown notionally.

  A manufacturing apparatus 10 shown in FIG. 1 manufactures an acidic gas separation membrane 50 according to the manufacturing method of the present invention as conceptually shown in FIG. 2 by a so-called roll-to-roll method (hereinafter also referred to as RtoR). It is.

As is well known, RtoR is a process of drawing or drying a coating composition while pulling out a workpiece from a roll wound with a long workpiece and transporting the workpiece in the longitudinal direction. It is a manufacturing method which goes and rolls the processed to-be-processed object in roll shape.
That is, the manufacturing apparatus 10 sends out the porous support 52 from a support roll 52R formed by winding a long (web-like) porous support 52 in a roll shape, and transports the porous support 52 in the longitudinal direction. However, the first facilitated transport film 54a is formed on the surface of the porous support 52, and the porous support 56 (hereinafter referred to as the treated support 56 for convenience) in which the facilitated transport film 54a is formed. It is wound into a roll (wound up) to obtain a treated support roll 56R.
Further, the manufacturing apparatus 10 feeds the processed support 56 from the processed support roll 56R and transports it in the longitudinal direction while forming a second facilitated transport film 54b on the facilitated transport film 54a. The acidic gas separation membrane 50 according to the invention is wound, and the acidic gas separation membrane 50 is wound into a roll shape to obtain a separation membrane roll 50R.

Such a manufacturing apparatus 10 basically includes a supply unit 12, a coating unit 14, a drying unit 18, and a winding unit 20.
In addition to the illustrated members, the manufacturing apparatus 10 manufactures a functional film (functional film) using RtoR, such as a pass roller (guide roller), a pair of conveyance rollers, a conveyance guide, and various sensors as necessary. You may have various members provided in the apparatus to do.

Here, in the manufacturing apparatus 10, the space including the supply unit 12 and the application unit 14 is a substantially closed space by the housing 26. Furthermore, a temperature / humidity measuring means 28 for measuring the temperature and humidity in the housing 26 and a temperature / humidity adjusting means 30 for adjusting the temperature and humidity in the housing 26 are provided inside the housing 26.
When forming the second layer (second and subsequent layers) facilitated transport film 54b (laminated film forming step), the manufacturing apparatus 10 for carrying out the manufacturing method of the present invention (the laminated film forming step) determines the temperature and humidity of the temperature / humidity measuring means 28. Depending on the measurement result, the temperature and humidity adjusting means 30 adjusts the temperature in the housing 26 to 10 to 40 ° C. and adjusts the humidity in the housing 26 to 10 to 50% RH.
This will be described in detail later.

When the first facilitated transport film 54a is formed, the supply unit 12 has a support roll 52R formed by winding a long porous support 52 around the rotary shaft 34 in a roll, and the rotary shaft 34, that is, the support roll. This is a part that feeds the porous support 52 by rotating 52R.
Further, when forming the second layer facilitated transport film 54, the supply unit 12 is loaded with a processed support roll 56R formed by winding the processed support 56 in a roll shape on the rotating shaft 34, This is a part that feeds out the processed support 56 by rotating the rotating shaft 34, that is, the processed support roll 56R.
In addition, what is necessary is just to perform sending out and conveyance of such a porous support body 52 and the processed support body 56 by a well-known method.

The porous support 52 (hereinafter also referred to as the support 52) is permeable to an acidic gas such as carbon dioxide, and can be applied with a coating composition for forming the facilitated transport film 54a (coating film). Furthermore, the facilitated transport film 54a and the facilitated transport film 54b formed are supported. In the following description, when it is not necessary to distinguish the facilitated transport film 54a and the facilitated transport film 54b, both are collectively referred to as the facilitated transport film 54.
As the forming material of the support 52, various known materials can be used as long as they can exhibit this function.

Here, in the manufacturing method of the present invention, the support body 52 may be a single layer, but as shown in FIG. 2, it has a two-layer structure including a porous film 52a and an auxiliary support film 52b. preferable. By having such a two-layer structure, the support 52 more reliably expresses the functions of acid gas permeability, application of the coating composition to be the facilitated transport film 54, and support of the facilitated transport film 54. .
In the case where the support 52 is a single layer, various materials exemplified below as the porous film 52a and the auxiliary support film 52b can be used as the forming material.

In this two-layered support 52, the porous membrane 52a is on the facilitated transport membrane 54 side.
The porous membrane 52a is preferably made of a material having heat resistance and low hydrolyzability. Specific examples of the porous membrane 52a include membrane filter membranes such as polysulfone, polyethersulfone, polypropylene and cellulose, interfacial polymerized thin films of polyamide and polyimide, polytetrafluoroethylene (PTFE) and high molecular weight polyethylene. An example is a stretched porous membrane.
Among them, a stretched porous membrane of PTFE or high molecular weight polyethylene has a high porosity, is small in inhibition of diffusion of acidic gas (especially carbon dioxide gas), and is preferable from the viewpoints of strength and manufacturing suitability. Among them, a stretched porous membrane of PTFE is preferably used in terms of heat resistance and low hydrolyzability.

The porous membrane 52a is hydrophobic in order that the facilitated transport membrane 54 containing moisture can easily penetrate into the porous portion in the use environment and does not cause deterioration in film thickness distribution or performance over time. Is preferred. The same applies to the case where the support has a single layer structure.
The porous membrane 52a preferably has a maximum pore diameter of 1 μm or less.
Furthermore, the average pore diameter of the pores of the porous membrane 52a is preferably 0.001 to 10 μm, more preferably 0.002 to 5 μm, and particularly preferably 0.005 to 1 μm. By setting the average pore diameter of the porous membrane 52a within this range, it is preferable that the adhesive application region described later sufficiently infiltrates the adhesive and that the porous membrane 52a prevents the passage of the acid gas. Further, when the coating composition described later is applied, it is possible to prevent the film surface from becoming non-uniform due to capillary action or the like.

The auxiliary support film 52b is provided to reinforce the porous film 52a.
Various materials can be used as the porous membrane 52a as long as it satisfies the required strength, stretch resistance and gas permeability. For example, a nonwoven fabric, a woven fabric, a net, and a mesh having an average pore diameter of 0.001 to 10 μm can be appropriately selected and used.

The auxiliary support film 52b is also preferably made of a material having heat resistance and low hydrolyzability, like the porous film 52a described above.
Considering this point, the fibers constituting the nonwoven fabric, woven fabric, and knitted fabric are excellent in durability and heat resistance, polyolefin such as polypropylene (PP), modified polyamide such as aramid (trade name), polytetrafluoro Fibers made of fluorine-containing resins such as ethylene and polyvinylidene fluoride are preferred. It is preferable to use the same material as the resin material constituting the mesh. Among these materials, a non-woven fabric made of PP that is inexpensive and has high mechanical strength is particularly preferably exemplified.

  When the support body 52 has the auxiliary support film 52b, the mechanical strength can be improved. Therefore, even in the manufacturing method using RtoR in the illustrated example, wrinkles on the support 52 can be prevented and productivity can be increased.

If the support 52 is too thin, the strength is difficult. Considering this point, the thickness of the porous membrane 52a is preferably 5 to 100 μm, and the thickness of the auxiliary support membrane 52b is preferably 50 to 300 μm.
Moreover, when making the support body 52 into a single layer, as for the thickness of the support body 52, 30-500 micrometers is preferable.

The support body 52 sent out from the support body roll 52R and the processed support body 56 sent out from the processed support body roll 56R are transported in the longitudinal direction and then transported to the coating unit 14 to facilitate transport film. The coating composition to be 54a and the facilitated transport film 54b is applied.
In the following description, only the support body 52 is shown as a representative of both the support body 52 and the processed support body 56 when it is not necessary to distinguish between them.

In the production method of the present invention, the conveying speed of the support 52 may be appropriately set according to the type of the support 52 and the viscosity of the coating composition.
Here, if the conveying speed of the support 52 is too fast, there is a risk that the coating film thickness uniformity of the coating composition is reduced and the coating composition is insufficiently dried, and if it is too slow, the productivity is lowered. . Considering this point, the conveyance speed of the support 52 is preferably 0.5 m / min or more, more preferably 0.75 to 200 m / min, and particularly preferably 1 to 200 m / min.

The facilitated transport film 54 (the facilitated transport film 54a and the facilitated transport film 54b) contains a hydrophilic compound such as a hydrophilic polymer, a carrier that reacts with an acidic gas, water, and the like.
Therefore, the coating composition for forming such a facilitated transport film 54 is a composition containing a hydrophilic compound, a carrier and water (room temperature water or warm water), or further a necessary component such as a crosslinking agent ( Paint / coating liquid). The hydrophilic compound may be crosslinked, partially crosslinked, or uncrosslinked, or a mixture of these.

  The hydrophilic compound functions as a binder, holds moisture in the facilitated transport film 54, and exhibits a function of separating a gas such as carbon dioxide by the carrier. Moreover, it is preferable that a hydrophilic compound has a crosslinked structure from a heat resistant viewpoint.

From the viewpoint that the hydrophilic compound can be dissolved in water to form a coating solution, and the facilitated transport film 54 preferably has high hydrophilicity (moisturizing properties), those having high hydrophilicity are preferable.
Specifically, the hydrophilic compound preferably has a hydrophilicity of 0.5 g / g or more, more preferably 1 g / g or more, more preferably 5 g / g of the physiological saline. More preferably, it has a hydrophilicity of g or more, particularly preferably has a hydrophilicity of 10 g / g or more, and most preferably has a hydrophilicity of 20 g / g or more.

What is necessary is just to select the weight average molecular weight of a hydrophilic compound suitably in the range which can form a stable film | membrane. Specifically, 20,000 to 2,000,000 is preferable, 25,000 to 2,000,000 is more preferable, and 30,000 to 2,000,000 is particularly preferable.
By setting the weight average molecular weight of the hydrophilic compound to 20,000 or more, the facilitated transport film 54 having a stable and sufficient film strength can be obtained.
In particular, when the hydrophilic compound has —OH as a crosslinkable group, the hydrophilic compound preferably has a weight average molecular weight of 30,000 or more. In this case, the weight average molecular weight is more preferably 40,000 or more, and more preferably 50,000 or more. When the hydrophilic compound has —OH as a crosslinkable group, the weight average molecular weight is preferably 6,000,000 or less from the viewpoint of production suitability.
Also, when having -NH ₂ as crosslinkable groups, hydrophilic compounds are those preferably has a weight average molecular weight of 10,000 or more. In this case, the weight average molecular weight of the hydrophilic compound is more preferably 15,000 or more, and particularly preferably 20,000 or more. When the hydrophilic compound has —NH ₂ as a crosslinkable group, the weight average molecular weight is preferably 1,000,000 or less from the viewpoint of production suitability.
For example, when PVA is used as the hydrophilic compound, the weight average molecular weight of the hydrophilic compound may be a value measured according to JIS K 6726. Moreover, when using a commercial item, what is necessary is just to use the molecular weight nominally mentioned in a catalog, a specification, etc.

As the crosslinkable group forming the hydrophilic compound, those capable of forming a hydrolysis-resistant crosslinked structure are preferably selected.
Specific examples include a hydroxy group, an amino group, a chlorine atom, a cyano group, a carboxy group, and an epoxy group. Among these, an amino group and a hydroxy group are preferably exemplified. Furthermore, most preferably, a hydroxy group is illustrated from the viewpoint of affinity with a carrier and a carrier carrying effect.

  Specific examples of hydrophilic compounds include those having a single crosslinkable group such as polyallylamine, polyacrylic acid, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylamide, polyethyleneimine, polyvinylamine, polyornithine, polylysine, Examples include polyethylene oxide, water-soluble cellulose, starch, alginic acid, chitin, polysulfonic acid, polyhydroxymethacrylate, poly-N-vinylacetamide and the like. Most preferred is polyvinyl alcohol. Moreover, as a hydrophilic compound, these copolymers are also illustrated.

Examples of the hydrophilic compound having a plurality of crosslinkable groups include polyvinyl alcohol-polyacrylic acid copolymers. A polyvinyl alcohol-polyacrylic salt copolymer is preferable because of its high water absorption ability and high hydrogel strength even at high water absorption.
The content of polyacrylic acid in the polyvinyl alcohol-polyacrylic acid copolymer is, for example, 1 to 95 mol%, preferably 2 to 70 mol%, more preferably 3 to 60 mol%, and particularly preferably 5 to 50 mol%. It is. The content of acrylic acid can be controlled by a known synthesis method.
In the polyvinyl alcohol-polyacrylic acid copolymer, the polyacrylic acid may be a salt. Examples of the polyacrylic acid salt in this case include ammonium salts and organic ammonium salts in addition to alkali metal salts such as sodium salts and potassium salts.

Polyvinyl alcohol is also available as a commercial product. Specific examples include PVA117 (manufactured by Kuraray Co., Ltd.), poval (manufactured by Kuraray), polyvinyl alcohol (manufactured by Aldrich), J-poval (manufactured by Nippon Vinegarten Poval). Although there are various molecular weight grades, those having a weight average molecular weight of 130,000 to 300,000 are preferred.
A polyvinyl alcohol-polyacrylate copolymer (sodium salt) is also available as a commercial product. For example, Crustomer AP20 (made by Kuraray Co., Ltd.) is exemplified.

  In the facilitated transport film 54 of the production method of the present invention, two or more hydrophilic compounds may be mixed and used.

The content of the hydrophilic compound in the coating composition is such that the hydrophilic compound functions as a binder and can sufficiently retain moisture in the formed facilitated transport film 54, depending on the type of the hydrophilic composition or carrier. Accordingly, it may be set appropriately.
Specifically, the amount of the facilitated transport film 54 is preferably 0.5 to 50% by mass, more preferably 0.75 to 30% by mass, and 1 to 15% by mass. Particularly preferred. By setting the content of the hydrophilic compound within this range, the above-mentioned function as a binder and the moisture retention function can be stably and suitably expressed.

The crosslinked structure of the hydrophilic compound can be formed by a known method such as thermal crosslinking, ultraviolet crosslinking, electron beam crosslinking, radiation crosslinking, or photocrosslinking.
Photocrosslinking or thermal crosslinking is preferred, and thermal crosslinking is most preferred.

Moreover, it is preferable that a coating composition contains a crosslinking agent.
As the crosslinking agent, one containing a crosslinking agent that reacts with a hydrophilic compound and has two or more functional groups capable of crosslinking such as thermal crosslinking or photocrosslinking is selected. The formed crosslinked structure is preferably a hydrolysis-resistant crosslinked structure.
From such a viewpoint, as a crosslinking agent added to the coating composition, an epoxy crosslinking agent, a polyvalent glycidyl ether, a polyhydric alcohol, a polyvalent isocyanate, a polyvalent aziridine, a haloepoxy compound, a polyvalent aldehyde, a polyvalent amine, An organic metal type crosslinking agent etc. are illustrated suitably. More preferred are polyvalent aldehydes, organometallic crosslinking agents and epoxy crosslinking agents, and among them, polyvalent aldehydes such as glutaraldehyde and formaldehyde having two or more aldehyde groups are preferred.

As an epoxy crosslinking agent, it is a compound which has 2 or more of epoxy groups, and the compound which has 4 or more is also preferable. Epoxy crosslinking agents are also available as commercial products, for example, trimethylolpropane triglycidyl ether (manufactured by Kyoeisha Chemical Co., Ltd., Epolite 100MF, etc.), Nagase ChemteX Corporation EX-411, EX-313, EX-614B, Examples include EX-810, EX-811, EX-821, EX-830, NOF Corporation Epiol E400, and the like.
Moreover, the oxetane compound which has cyclic ether as a compound similar to an epoxy crosslinking agent is also used preferably. The oxetane compound is preferably a polyvalent glycidyl ether having two or more functional groups, and commercially available products include, for example, EX-411, EX-313, EX-614B, EX-810, EX-811, EX manufactured by Nagase ChemteX Corporation. -821, EX-830, 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, propylene Examples include 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 oxyethylene oxypropylene block copolymer. Examples include coalescence, pentaerythritol, and sobitol.

Examples of the polyvalent isocyanate include 2,4-toluylene diisocyanate and hexamethylene diisocyanate.
Examples of the polyvalent aziridines include 2,2-bishydroxymethylbutanol-tris [3- (1-acylidinyl) propionate], 1,6-hexamethylenediethyleneurea, diphenylmethane-bis-4,4′-N, N. Examples include '-diethylene urea.

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.
Furthermore, examples of the organometallic crosslinking agent include organic titanium crosslinking agents and organic zirconia crosslinking agents.

For example, when polyvinyl alcohol having a weight average molecular weight of 130,000 or more is used as the hydrophilic compound, it is possible to form a crosslinked structure having good reactivity with this hydrophilic compound and excellent hydrolysis resistance. Therefore, an epoxy crosslinking agent and glutaraldehyde are preferably used.
Moreover, when using a polyvinyl alcohol-polyacrylic acid copolymer as a hydrophilic compound, an epoxy crosslinking agent and glutaraldehyde are preferably utilized.
In addition, when a polyallylamine having a weight average molecular weight of 10,000 or more is used as the hydrophilic compound, it is possible to form a crosslinked structure that has good reactivity with the hydrophilic compound and excellent hydrolysis resistance. Therefore, an epoxy crosslinking agent, glutaraldehyde, and an organometallic crosslinking agent are preferably used.
Further, when polyethyleneimine or polyallylamine is used as the hydrophilic compound, an epoxy crosslinking agent is preferably used.

What is necessary is just to set the quantity of a crosslinking agent suitably according to the kind of hydrophilic compound and crosslinking agent which are added to a coating composition.
Specifically, the amount is preferably 0.001 to 80 parts by weight, more preferably 0.01 to 60 parts by weight, and particularly preferably 0.1 to 50 parts by weight with respect to 100 parts by weight of the crosslinkable group possessed by the hydrophilic compound. preferable. By setting the content of the cross-linking agent in the above range, a facilitated transport film having good cross-linking structure formation and excellent shape maintainability can be obtained.
Further, when focusing on the crosslinkable group possessed by the hydrophilic compound, the crosslinked structure is formed by reacting 0.001 to 80 mol of a crosslinking agent with respect to 100 mol of the crosslinkable group possessed by the hydrophilic compound. preferable.

In the facilitated transport film 54, the carrier (acid gas carrier) reacts with an acid gas (for example, carbon dioxide gas (CO ₂ )) to transport the acid gas.

The carrier is a water-soluble compound having affinity with acidic gas and showing basicity. Specific examples include alkali metal compounds, nitrogen-containing compounds, and sulfur oxides.
The carrier may react indirectly with the acid gas, or the carrier itself may react directly with the acid gas.
The former reacts with other gas contained in the supply gas, shows basicity, and the basic compound reacts with acidic gas. More specifically, OH react with steam (water) ^- was released, the OH ^- that reacts with CO _2, a compound can be incorporated selectively CO ₂ in facilitated transport membrane 54 For example, an alkali metal compound.
The latter is such that the carrier itself is basic, for example, a nitrogen-containing compound or a sulfur oxide.

  Examples of the alkali metal compound include alkali metal carbonates, alkali metal bicarbonates, and alkali metal hydroxides. Here, as the alkali metal, an alkali metal element selected from cesium, rubidium, potassium, lithium, and sodium is preferably used. In addition, in this invention, an alkali metal compound contains the salt and its ion other than alkali metal itself.

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.
Furthermore, examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, and cesium hydroxide.
Among these, alkali metal carbonates are preferable, and compounds having high solubility in water, potassium, rubidium, and cesium are preferable from the viewpoint of good affinity with acidic gas.

Moreover, when using an alkali metal compound as a carrier, two or more kinds of carriers may be used in combination.
When two or more kinds of carriers are present in the facilitated transport film 54, different carriers can be separated from each other in the film. As a result, due to the difference in deliquescence of a plurality of carriers, the facilitated transport film 54 or the facilitated transport film 54 and other members are adhered to each other due to the water absorption of the facilitated transport film 54 at the time of manufacture. (Blocking) can be suitably suppressed.
Moreover, when using 2 or more types of alkali metal compounds as a carrier by the point of being able to obtain the blocking inhibitory effect more suitably, the deliquescence property is more excellent than the first compound having deliquescence and the first compound. It is preferable to include a second compound having a low specific gravity. As an example, the first compound is exemplified by cesium carbonate, and the second compound is exemplified by potassium carbonate.

Nitrogen-containing compounds include amino acids such as glycine, alanine, serine, proline, histidine, taurine, diaminopropionic acid, hetero compounds such as pyridine, histidine, piperazine, imidazole, triazine, monoethanolamine, diethanolamine, triethanolamine , Alkanolamines such as monopropanolamine, dipropanolamine and tripropanolamine, cyclic polyetheramines such as cryptand [2.1] and cryptand [2.2], cryptand [2.2.1] and cryptand [ And bicyclic polyetheramines such as 2.2.2], porphyrin, phthalocyanine, ethylenediaminetetraacetic acid and the like.
Further, examples of the sulfur compound include amino acids such as cystine and cysteine, polythiophene, dodecylthiol and the like.

What is necessary is just to set content of the carrier in a coating composition suitably according to the kind etc. of a carrier or a hydrophilic compound. Specifically, the amount of the carrier in the facilitated transport film 54 is preferably 0.3 to 30% by mass, more preferably 0.5 to 25% by mass, and 1 to 20% by mass. Is particularly preferred.
By setting the content of the carrier in the coating composition within the above range, salting out before coating can be suitably prevented, and the facilitated transport film 54 formed can reliably exhibit the function of separating acidic gas. .
Moreover, the amount ratio of the hydrophilic compound to the carrier in the coating composition is preferably 1: 9 to 2: 3 or less, more preferably 1: 4 to 2: 3 or less, in terms of the hydrophilic compound: carrier mass ratio. : 7-2: 3 is particularly preferable.

The coating composition may contain a thickener as necessary.
As the thickener, for example, thickening polysaccharides such as agar, carboxymethylcellulose, carrageenan, chitansan gum, guar gum and pectin are preferable. Among these, carboxymethylcellulose is preferable from the viewpoints of film forming property, availability, and cost.
By using carboxymethyl cellulose, a coating composition having a desired viscosity can be easily obtained with a small amount of content, and at least a part of components other than the solvent contained in the coating solution cannot be dissolved in the coating solution and deposited. There is little fear of it.

The content of the thickener in the coating composition is preferably as small as possible as long as the content of the thickener in the composition (coating liquid) can be adjusted to the target viscosity.
As a general index, 10% by mass or less is preferable, 0.1 to 5% by mass is more preferable, and 0.1 to 2% by mass or less is more preferable.

  The coating composition (facilitated transport film 54) may contain various components as necessary in addition to such a hydrophilic compound, a crosslinking agent and a carrier, or a thickener.

Examples of such components include an antioxidant such as dibutylhydroxytoluene (BHT), a compound having 3 to 20 carbon atoms or a fluorinated alkyl group having 3 to 20 carbon atoms and a hydrophilic group, and a siloxane structure. Specific compounds such as compounds having a surfactant, surfactants such as sodium octoate and sodium 1-hexasulfonate, polymer particles such as polyolefin particles and polymethyl methacrylate particles, and the like.
In addition, a catalyst, a moisturizing (moisture absorbing) agent, an auxiliary solvent, a film strength adjusting agent, a defect detecting agent and the like may be used as necessary.

What is necessary is just to prepare a coating composition by a well-known method. That is, first, the facilitated transport film 54 is obtained by adding a hydrophilic compound, a carrier, and various components to be added as necessary to water (room temperature water or warm water) in appropriate amounts, and stirring sufficiently. A coating composition is prepared.
In the preparation of the coating composition, if necessary, dissolution of each component may be promoted by heating with stirring. Moreover, after adding a hydrophilic compound to water and melt | dissolving, precipitation (salting out) of a hydrophilic compound can be effectively prevented by adding a carrier gradually and stirring.

Here, it is preferable that the coating composition to be the facilitated transport film 54a and the facilitated transport film 54b has a temperature of 15 to 35 ° C. and a viscosity of 0.1 to 5 Pa · sec at the time of coating. In addition, a viscosity is a viscosity measured value in rotation speed 60rpm by a B type viscosity system.
In the present invention, by setting the temperature and viscosity of the coating composition at the time of coating within this range, it is possible to prevent sedimentation of each component in the coating film of the coating composition, and to prevent unnecessary coating composition in the coating apparatus 36 described later. It is possible to prevent outflow, carrier precipitation (salting out), mixing of bubbles into the coating composition (coating film), and the like, and to form a coating film with a uniform film thickness.
In addition, what is necessary is just to confirm as follows that the coating composition is 15-5 degreeC, and the viscosity in the rotation speed 60rpm by a B-type viscosity system is 0.1-5 Pa.sec. That is, the prepared coating composition is put into a stainless steel container (for example, an inner diameter of 4 cm and a height of 12 cm) so that the viscometer cylinder (rotor) is sufficiently immersed in the coating composition. Next, this stainless steel container is immersed in a temperature-adjustable water tank, and while adjusting the temperature of the applied coating composition to a range of 15 ° C. to 35 ° C., a B-type viscometer (for example, BL21 to TECH Jam Co., Ltd.). 100,000 mPa · s / KN3312481) is operated, the value for each temperature at a rotational speed of 60 rpm is read, and the viscosity of the coating solution is measured according to JIS Z8803.

In the present invention, the coating composition for forming the first facilitated transport film 54a and the coating composition to be formed for the second facilitated transport film 54b may be the same, or may contain the composition. The type and number of components, pH, concentration of each component contained, viscosity, and the like may be different from each other.
That is, in the present invention, the first facilitated transport film 54a and the second facilitated transport film 54b may be films having the same composition or different compositions.

When forming three or more facilitated transport films, all facilitated transport films may be formed of the same coating composition, or all facilitated transport films may be formed of different coating compositions. Alternatively, the second and subsequent facilitated transport films may be formed of the same coating composition and only the first facilitated transport film 54a may be formed of a different coating composition, or the first facilitated transport film 54a and two layers may be formed. One or more facilitated transport films after the first may be formed of the same coating composition, and other facilitated transport films may be formed of coating compositions having different compositions (compositions may be the same or different). Good.
That is, in the present invention, a coating composition for forming the first facilitated transport film 54a (initial film forming process) and a coating composition for forming at least one facilitated transport film thereafter (laminated film forming process) In the above, the same coating composition or different coating compositions may be used.

As described above, the application unit 14 is a part that applies such a coating composition to the support 52 (processed support 56) conveyed in the longitudinal direction.
In the illustrated example, the coating unit 14 includes a coating device 36 and a backup roller 38. That is, the support body 52 is conveyed while being kept at a predetermined application position by the backup roller 38, and the application composition is applied by the application device 36 to form a coating film (liquid film) of the application composition.

As the coating device 36, various known devices can be used.
Specifically, roll coater, direct gravure coater, offset gravure coater, single roll kiss coater, 3 reverse roll coater, forward rotation roll coater, curtain flow coater, extrusion die coater, air doctor coater, blade coater, rod coater And knife coaters, squeeze coaters, reverse roll coaters, bar coaters and the like.
Among these, considering the preferable viscosity of the coating composition, the coating amount of the coating composition, and the like, a roll coater, a bar coater, a normal rotation roll coater, a knife coater, and the like are preferably used.

Here, in the manufacturing method of the present invention, when the first facilitated transport film 54a is formed (initial film forming step), the coating device 34 is configured to apply the coating thickness (the coating composition to be applied to the support 52). The coating composition is applied to the support 52 so that the thickness of the substrate is 0.01 to 3 mm.
In addition, when forming a facilitated-transport film | membrane by application | coating 3 times or more (when forming the whole facilitated-transport film | membrane by 3 layers or more), formation of the facilitated-transport film | membranes other than the lowest layer and the top layer for the same reason. Also in the process, the thickness of the coating film of the coating composition is preferably 0.01 to 3 mm. That is, when performing the facilitated transport film forming process three times or more, the facilitated transport film forming process in which the facilitated transport film is formed in the lower layer and the facilitated transport film is further formed in the upper layer is a laminated film formation. It is preferable to satisfy the conditions of the coating film thickness in the initial film forming process while satisfying the process conditions.

In the formation of the first facilitated transport film 54a, when the thickness of the coating film is less than 0.01 mm, inconveniences such as being unable to form the facilitated transport film 54a that expresses the intended function occur.
On the other hand, when the thickness of the coating film exceeds 3 mm, there are problems such as generation of defects due to mixing of bubbles and foreign matters, and insufficient drying in the drying unit 18 described later, resulting in an undried state.
Considering this point, the thickness of the coating film of the coating composition in the first facilitated transport film 54a is preferably 0.05 to 2.5 mm, more preferably 0.1 to 2 mm.

Further, in the production method of the present invention, the initial facilitated transport film 54a formed by drying the coating composition to be described later has a thickness that can achieve the desired performance depending on the composition of the facilitated transport film 54a and the like. May be set as appropriate. Specifically, 1-100 micrometers is preferable and 10-80 micrometers is more preferable.
That is, in the production method of the present invention, when the first facilitated transport film 54a is formed, the coating composition is formed so that the facilitated transport film 54a having the above thickness is obtained with a coating thickness of 0.01 to 3 mm. Is preferably prepared.

On the other hand, the coating film thickness of the coating composition when forming the second layer (second and subsequent layers) facilitated transport film 54b (laminated film forming step) is the concentration of the hydrophilic compound or carrier in the coating composition, the purpose What is necessary is just to determine suitably according to the film thickness etc. of the facilitated-transport film | membrane 54 to make.
Specifically, the coating thickness when forming the facilitated transport film 54b is preferably 0.05 to 2.5 mm, and more preferably 0.1 to 2 mm.
By setting the coating film thickness of the second layer facilitated transport film 54b within this range, the coating film that becomes the second layer facilitated transport film 54b can be suitably dried. Defects in the second layer facilitated transport film 54b This is preferable in that it can be prevented.
When the entire facilitated transport film is formed of three or more layers, the coating thickness when forming the facilitated transport film other than the lowermost layer and the uppermost layer is set to 0.01 to 3 mm as described above. Is preferable, 0.05 to 2.5 mm is more preferable, and 0.1 to 2 mm is particularly preferable.

In the production method of the present invention, the thickness of the facilitated transport film 54b of the second layer (second and subsequent layers) formed by drying the coating composition described later is the composition of the facilitated transport film 54b and the intended facilitated transport. What is necessary is just to set suitably the film thickness from which the target thickness and performance are obtained according to the thickness of the film | membrane 54, etc. Specifically, 1-100 micrometers is preferable and 10-80 micrometers is more preferable.
That is, like the first facilitated transport film 54a, it is preferable to prepare the coating composition 54 so that the facilitated transport film 54b having this film thickness can be obtained with the above-described coating film thickness.

  In the present invention, the thickness of the first facilitated transport film 54a and the second facilitated transport film 54b (and the third and subsequent facilitated mail films) may be the same or different. In the case of having three or more facilitated transport films, the thickness of the second and subsequent facilitated transport films may be the same or different.

Furthermore, in the present invention, the total film thickness of the first facilitated transport film 54a and the second facilitated transport film 54b (further, the third and subsequent facilitated mail films) is preferably 2 to 200 μm, and preferably 20 to 160 μm. Is more preferable.
By making the total film thickness of the facilitated transport film 54a and the second facilitated transport film 54b within this range, it is possible to stably obtain good raw material gas processing efficiency and acidic gas separation performance. preferable.

As described above, the supply unit 12 and the application unit 14 are disposed in the housing 26. Further, a temperature / humidity measuring means 28 and a temperature / humidity adjusting means 30 are arranged in the housing 26.
The temperature / humidity measuring means 28 measures the temperature and humidity in the housing 26. The temperature / humidity measuring means 28 may be configured using a known temperature sensor or humidity sensor.
The temperature / humidity adjusting means 30 adjusts the temperature and humidity in the housing 26 according to the measurement result of the temperature and humidity in the housing 26 by the temperature / humidity measuring means 28. The temperature / humidity adjusting means 28 may also be configured using a known dehumidifying means, humidifying means, heating device, or cooling device.

  When forming the second layer facilitated transport film 54a (and the third and subsequent facilitated transport films), the manufacturing apparatus 10 measures the temperature and humidity in the housing 26 by the temperature / humidity measuring means, and the measurement result Accordingly, the temperature / humidity adjusting means 30 adjusts the temperature and humidity in the housing 26 to manage the temperature in the housing 26 to 10 to 40 ° C. and the humidity to 2 to 50% RH. This will be described in detail later.

The support 52 (treated support 56) coated with the coating composition in the coating unit 14 is guided by the pass roller 40a that contacts the back surface (the surface opposite to the coating surface of the coating composition) and conveyed to the drying unit 18. Is done.
The drying unit 18 (drying step) removes at least a part of water from the coating composition coated on the support 52 and dries (or further crosslinks the hydrophilic compound), thereby the first facilitated transport film 54a. The processed support 56 is formed, and the second layer facilitated transport film 54b is formed to produce the acid gas separation membrane 50.
In the production method of the present invention, after the coating composition is dried, the facilitated transport film 54a and the facilitated transport film 54b may be formed by crosslinking the hydrophilic compound as necessary.

As the drying method, various known methods for drying by removing water, such as hot air drying or a drying method by heating the support 52, can be used.
When performing warm air drying, the speed of the warm air may be set as appropriate so that the coating composition can be dried quickly and the coating film (gel film) of the coating composition does not collapse. Specifically, 0.5 to 200 m / min is preferable, 0.75 to 200 m / min is more preferable, and 1 to 200 m / min is particularly preferable.
Further, the temperature of the warm air may be appropriately set to a temperature at which the support 52 is not deformed and the coating composition can be dried quickly. Specifically, the film surface temperature is preferably 1 to 120 ° C, more preferably 2 to 115 ° C, and particularly preferably 3 to 110 ° C.

When drying the support 52 by heating, the temperature at which the support 52 is not deformed and the coating composition can be dried quickly may be set as appropriate. Moreover, you may use blowing of a dry wind for heating of the support body 52 together.
Specifically, the temperature of the support 52 is preferably 60 to 120 ° C, more preferably 60 to 90 ° C, and particularly preferably 70 to 80 ° C. In this case, the film surface temperature is preferably 15 to 80 ° C, and more preferably 30 to 70 ° C.

The support 52 dried from the coating composition coating in the drying unit 18, that is, the treated support 56, and the treated support dried from the coating composition in the drying unit 18, that is, the acid gas separation membrane 50. Is guided to the pass roller 40 a and then conveyed to the winding unit 24.
The take-up unit 24 winds the treated support 56 around the take-up shaft 42 to form a treated support roll 56R, and winds the acidic gas separation membrane 50 around the take-up shaft 42 to form a separation membrane roll 50R. To do.

The winding unit 24 includes the above-described winding shaft 42 and three pass rollers 40c to 40e.
The processed support 56 is guided along a predetermined transport station path by the pass rollers 40c to 40e, and wound up by the winding shaft 42 (processed support roll 56R) to be a processed support roll 56R.
Similarly, the acidic gas separation membrane 50 is guided along a predetermined transport station path by the pass rollers 40c to 40e, and taken up by the take-up shaft 42 (separation membrane roll 50R) to form the separation membrane roll 50R.
Here, the three pass rollers 40c to 40e also act as tension cutters, and guide the processed support 56 and the like to meander.

  Hereinafter, the production method of the acidic gas separation membrane of the present invention will be described in more detail by explaining an example of the operation of the production apparatus 10.

First, the support roll 52R is mounted on the rotating shaft 34 of the supply unit 12, and the rotating shaft 34 is rotated to feed the support 52 from the support roll 52R. Subsequently, the support 52 sent out from the support roll 52R passes through the coating unit 14 (backup roller 38), the pass roller 40a, the drying unit 18, the pass roller 40b, and the pass rollers 40c to 40e, and reaches a take-up shaft 42. The tip of the support body 52 is wound around the take-up shaft 42.
Further, the coating device 36 is filled with a necessary amount of the coating composition.

When the support body 52 is passed through a predetermined transport path and the coating device 36 is filled with the coating composition, the rotary shaft 34, the winding shaft 42, the backup roller 38, etc. are driven in synchronism with each other. Start conveyance.
In this case, the temperature and humidity of the housing 26 housing the supply unit 12 and the application unit 14 are controlled within a predetermined range by the temperature / humidity measuring unit 28 and the temperature / humidity adjusting unit 30 as necessary. Also good.

The support body 52 sent out from the support body roll 52R is first transported while being supported at a predetermined application position by the backup roller 38 in the coating unit 14 while being transported in the longitudinal direction. The coating composition to be the facilitated transport film 54a is applied so as to have a predetermined coating thickness (coating amount).
In addition, application | coating of this coating composition is performed so that the thickness of a coating film may be 0.01-3 mm as mentioned above. As described above, the coating composition at the time of coating preferably has a temperature of 15 to 35 ° C. and a viscosity of 0.1 to 5 Pa · sec.

The support 52 coated with the coating composition to be the first facilitated transport film 54a is then guided by the pass roller 40a to reach the drying unit 18, where the coating composition is dried, The treated support 56 is provided with the facilitated transport film 54a.
The processed support 56 is guided by the pass roller 40b, conveyed to the winding unit 20, guided along a predetermined conveyance path by the pass rollers 40c to 40e, wound around the winding shaft 42, and processed support roll. 56R.

  When the processed support roll 56R formed by winding the processed support 56 having a predetermined length is produced, the conveyance of the support 52 is stopped. Next, the processed support 56 is cut downstream of the drying unit 18, wound around the processed support roll 56 </ b> R, and the processed support roll 56 </ b> R is removed from the manufacturing apparatus 10. Further, the support roll 52R is removed from the rotating shaft 34, and the remaining support 52 is removed.

  Next, the temperature and humidity of the housing 26 that accommodates the supply unit 12 and the coating unit 14 are measured by the temperature / humidity measuring unit 28, and the temperature and humidity in the housing 26 are adjusted by the temperature / humidity adjusting unit 30 according to the measurement result. Then, the housing 26 is managed so that the temperature inside the housing 26 is in the range of 10 to 40 ° C. and the humidity is in the range of 10 to 50% RH.

Then, the processed support roll 56R is mounted on the rotating shaft 34 of the supply unit 12, and the processed support 56 is fed from the processed support roll 56R by rotating the rotating shaft 34. Next, the processed support 56 sent out from the processed support roll 56R is passed through a predetermined transport path from the coating unit 14 to the winding shaft 42 in the same manner as described above, and the tip of the processed support 56 is wound up. Wrap around the shaft 42.
Further, the coating device 36 is filled with a necessary amount of the coating composition. As described above, this coating composition may be the same as or different from the coating composition on which the first facilitated transport film 54a is formed.

  When the temperature and humidity inside the housing 26 are properly controlled, the processed support 56 is passed through a predetermined transport path, and the coating device 36 is filled with the coating composition, the rotating shaft 34, the winding shaft 42, Then, the backup roller 36 and the like are driven in synchronization, and the conveyance of the support 52 is started.

The processed support 56 sent out from the processed support roll 56R is transported while being supported in a predetermined application position by the backup roller 38 in the coating unit 14 while being transported in the longitudinal direction, as before. The coating composition that forms the second facilitated transport film 54b is applied by the coating device 36 so as to have a predetermined coating thickness (coating amount).
Here, in the manufacturing method of the present invention, the temperature and humidity of the housing 26 that accommodates the supply unit 12 and the application unit 14 are measured, and the temperature and humidity in the housing 26 are adjusted according to the measurement result, and the housing Since the internal temperature is controlled (controlled) to 10 to 40 ° C. and the same humidity to 10 to 50% RH, the coating composition to be the second layer facilitated transport film 54b is uniformly distributed over the entire surface. Can be applied.

As described above, in an acidic gas separation membrane using a facilitated transport membrane, it is required to form a thick facilitated transport membrane in order to suppress hydrogen permeation and prevent defects in the facilitated transport membrane. Yes. In order to form a facilitated transport film with a thick film, it is only necessary to apply a thick coating composition. However, if the coating composition is too thick, the coating film cannot be dried properly and unevenness is generated. In addition, uneven distribution of carriers or the like may occur.
On the other hand, by forming the facilitated transport film a plurality of times, this problem can be solved and a thick facilitated transport film can be formed in total. That is, after forming the first facilitated transport film 54a, the coating composition is applied and dried to form the second facilitated transport film 54b, and further, if necessary, the facilitated transport film is formed. Thus, the intended thick facilitated transport film can be formed.

As described above, the first facilitated transport film 54a is hydrophilic. Moreover, the coating composition used as the 2nd facilitated-transport film | membrane 54b contains many waters. Therefore, when considered normally, when the coating composition is applied on the first facilitated transport film 54a, it should be possible to apply the coating composition with very good coating properties (coating).
However, according to the study of the present inventor, when a coating composition to be a facilitated transport film is applied on the facilitated transport film, the coating composition is repelled, and the portion where the coating composition is not applied is pinhole-shaped. In many cases, it may occur.

  The present inventor has intensively studied to solve this problem. As a result, the facilitated transport film has a high water absorption, and in the formation of the second layer (second and subsequent layers) facilitated transport film (laminated film forming step), the second facilitated transport film By applying the humidity and temperature of the space to which the first facilitated transport film 54a (previously formed facilitated transport film) is exposed to the above range until the coating composition to be 54b is applied, this problem of flipping is reduced. I found it possible to solve it.

An acid gas separation membrane using a facilitated transport membrane is often used in a gas environment having a water vapor partial pressure. In general, an acid gas separation membrane having a facilitated transport membrane tends to have a higher acid gas separation rate (permeation rate) as the facilitated transport membrane has higher water absorption.
Therefore, the facilitated transport film has a configuration in which a hydrophilic compound having high water absorption such as a super water absorbent resin is used as a binder and carriers are dispersed in the binder. Many carriers also have high water absorption. Furthermore, it is common to use a highly water-absorbing additive added to the facilitated transport film as necessary.
Therefore, the facilitated transport film has very high water absorption.

However, since the water absorption is high, the first facilitated transport film 54a is fed from the treated support roll 56R when the second facilitated transport film 54b is formed, and the coating composition 14 is coated with the coating composition. In the meantime, moisture in the air is absorbed, and moisture adheres to the surface, resulting in a large number of water droplets.
In RtoR, since the coating composition is applied while the treated support 56 is being conveyed, a shearing force is applied to the coating film when the coating film thickness is adjusted. At this time, the water droplets that have not been diffused into the coating composition act like a lubricant, and the coating composition applied onto the water droplets slips and moves so as to be repelled from above. A part where the coating composition is not applied is generated.
As a result, the coating film of the coating composition formed on the first facilitated transport film 54a is in a state in which a large number of pinholes are scattered. Even if such a coating film is dried to form the second facilitated transport film 54b, the formed facilitated transport film 54b has a thin portion or a defective portion where the film is not formed. End up.

On the other hand, in the manufacturing apparatus 10 that performs the manufacturing method of the present invention, the first facilitated transport film 54a is exposed in the housing 26 (before the coating composition is applied) in forming the second facilitated transport film 54b. The temperature and humidity of the space are controlled to 10 to 40 ° C. and 10 to 50% RH.
Therefore, it is possible to prevent moisture from adhering to the surface of the first facilitated transport film 54a, and uniformly apply the coating composition that forms the second facilitated transport film 54b on the entire surface of the first facilitated transport film 54a. By coating, a uniform facilitated transport film 54b having no defects can be formed on the entire surface.

When the temperature in the housing 26 is lower than 10 ° C., there arises a disadvantage that the initial facilitated transport film 54a is cracked.
On the other hand, if the temperature in the housing exceeds 40 ° C., the absolute amount of moisture is large even in a proper humidity range, so that it is not possible to sufficiently prevent moisture from adhering to the surface of the first facilitated transport film 54a. This will cause the film to be repelled.
Considering the above points, the temperature in the housing 26 is preferably 15 to 35 ° C.

In addition, when the humidity in the housing 26 is less than 10% RH, inconveniences such as film breakage occur in the first facilitated transport film 54a.
On the other hand, when the humidity in the housing 26 exceeds 50% RH, moisture cannot be sufficiently prevented from adhering to the surface of the first facilitated transport film 54a, and the coating film of the coating composition is repelled.
Considering the above points, the humidity in the housing 26 is preferably 20 to 45% RH, and more preferably 20 to 40% RH.

In the production method of the present invention, the coating composition to be the second facilitated transport film preferably has a contact angle with respect to the first facilitated transport film 54a of less than 90 °. That is, it is preferable to adjust the composition of the facilitated transport film, that is, the coating composition, so that the contact angle of the coating composition to be the second facilitated transport film with respect to the first facilitated transport film 54a is less than 90 °.
In the present invention, the temperature and humidity in the housing 26 are managed as described above, and the contact angle of the coating composition to be the second facilitated transport film with respect to the first facilitated transport film 54a is less than 90 °. By doing so, it is possible to form a coating film of a coating composition having a more uniform and good surface shape and to form a second layer of facilitated transport film 54b of higher quality.

  Even when the second facilitated transport film 54b is formed, the coating composition at the time of coating preferably has a temperature of 15 to 35 ° C. and a viscosity of 0.1 to 5 Pa · sec as described above. is there.

The treated support 56 coated with the coating composition to be the second layer facilitated transport film 54b is then guided by the pass roller 40a to reach the drying unit 18, where the coating composition is dried. Thus, the acidic gas separation membrane 50 in which the second facilitated transport membrane 54b is formed in addition to the first facilitated transport membrane 54a is obtained. The acidic gas separation membrane 50 has a uniform facilitated transport membrane 54b formed of a coating composition uniformly applied to the entire surface and having no defects.
The acidic gas separation membrane 50 is guided by the pass roller 40b, conveyed to the winding unit 20, guided along a predetermined conveyance path by the pass rollers 40c to 40e, wound around the winding shaft 42, and separated from the separation membrane roll 50R. Is done.

In the manufacturing apparatus 10 in the illustrated example, a housing 26 is formed so as to surround the supply unit 12 and the coating unit 14, and the temperature and humidity inside the housing 26 are managed within a predetermined range. However, in the present invention, in the formation of the second facilitated transport film 54b, the temperature and humidity of the space to which the first facilitated transport film 54a is exposed are controlled within a predetermined range before the coating composition is applied. do it.
Therefore, for example, in the illustrated example, the space downstream of the position where the coating composition is applied by the coating device 36 need not be managed for temperature and humidity.
However, in consideration of the ease of forming a space for performing management, it is preferable to form the housing 26 so as to surround the supply unit 12 and the application unit 14 and to manage the temperature and humidity therein as in the illustrated example. .

  In the production method of the present invention, the coated film is wound after being dried regardless of the first facilitated transport film 54a (initial film forming process) and the second facilitated transport film 54b (laminated film forming process). Even in the space where the facilitated transport film is exposed, that is, in the space where the facilitated transport films 54a and 54b are exposed from the outlet of the drying unit 18 to the winding unit 20, the temperature and humidity are controlled within a predetermined range. Is preferred.

Specifically, it is preferable to manage the humidity of the space where the facilitated transport film is exposed from the outlet of the drying unit 18 to the winding unit 20 to 10 to 60% RH, and to 10 to 40% RH. Is more preferable. Moreover, it is preferable to manage the temperature of the space where the facilitated transport film is exposed from the outlet of the drying unit 18 to the winding unit 20 to 15 to 35 ° C, and more preferably to 20 to 30 ° C.
Thereby, moisture absorption of the formed facilitated-transport film | membrane can be prevented, and it can prevent that the film | membrane peeling by contact with another member arises due to moisture absorption.

  The management of the temperature and humidity of the outlet of the drying unit 18 to the winding unit 20 may be basically performed in the same manner as the space where the facilitated transport film 54a exists before the coating composition is applied. . For example, the acidic gas separation membrane 50 and the transport path of the treated support 56 from the outlet of the drying unit 18 to the winding unit 20 and the winding unit 20 are surrounded by a housing, and the temperature and humidity in the housing are known. The temperature and humidity in the housing may be measured by the means and managed by a known means so as to achieve the target values.

In the above example, the first facilitated transport film 54a and the second facilitated transport film 54b are formed to form the acidic gas separation membrane 50 having the facilitated transport film having a two-layer structure.
However, in the present invention, an acidic gas separation membrane having three or more facilitated transport membranes is formed by repeatedly performing the same operation (laminated film forming step) as the formation of the second facilitated transport membrane 54b. Also good.
In addition, the number of repetitions of the facilitated transport film formation process may be determined as appropriate according to the composition of the facilitated transport film, the target film thickness, etc., but productivity, film thickness, film quality of the facilitated transport film, etc. Is usually 2 times (2 layers as in the illustrated example) to 3 times.

The manufacturing apparatus 10 in the illustrated example has only one coating unit 14 and drying unit 18, that is, an apparatus that can form only one layer of a facilitated transport film. 54a and the second facilitated transport film 54b are formed.
However, in the manufacturing method of the present invention, as schematically shown in FIG. 3, a manufacturing apparatus having two (or three or more) coating units 14a and drying units 18a, and coating units 14b and drying units 18b is used. The acidic gas separation membrane 50 may be manufactured by forming the first facilitated transport membrane 54a and the second facilitated transport membrane 54b.

  In this case, for example, in the space 46 including the application unit 14b downstream from the upstream drying unit 18a (which may include at least a part of the drying unit 18a), the temperature and humidity are 10 to 40 ° C. The first facilitated transport film 54a is formed by the upstream coating unit 14a and the drying unit 18a, and the second facilitated transport film 54b is formed by the downstream coating unit 14b and the drying unit 18b. do it.

Further, in the case of forming three or more layers of facilitated transport films using this apparatus, after the first facilitated transport film 54a and the second facilitated transport film 54b are formed by the first operation as before. The wound roll is mounted on the supply side, and the temperature and humidity are controlled at 10 to 40 ° C. and 10 to 50% RH in the space 48 including the roll and the upstream application unit 14a. A third facilitated transport film may be formed by the operation.
Alternatively, in the first operation, only the first facilitated transport film 54a is formed, the wound roll is mounted on the supply side, and the temperature and humidity are set to 10 to 40 ° C. in both the space 48 and the space 46. The second layer and the third layer facilitated transport film may be formed by the second operation under the control of 10 to 50% RH.
Furthermore, an acidic gas separation membrane having four or more layers of facilitated transport membranes may be formed by repeating the above operation.

The first aspect of the present invention described above adjusts the temperature and humidity of the space to which the first facilitated transport film 52a is exposed until the coating composition is applied in the step of forming the second facilitated transport film 54b. As a result, the coating composition to be the second facilitated transport film 54b is uniformly coated without causing repellency to form a uniform facilitated transport film 52b free from defects.
In contrast, in the second aspect of the present invention, in the formation process (laminated film formation process) of the second facilitated transport film 54b, the weight increase rate due to water absorption of the first facilitated transport film 54a is 40% by mass or less. The coating composition is applied under the following conditions. Specifically, when the facilitated transport film 54a of the treated support 56 wound around the treated support roll 56R is exposed to the outside air (when the facilitated transport film 54a is exposed to the outside air for application). To the second layer facilitated transport film 54b until the weight increase rate due to water absorption of the first facilitated transport film 54a is 40% by mass or less. The coating composition for the transport film 54b is applied.
Preferably, from the time when the drying of the first facilitated transport film 54a is completed, the temperature and humidity of the space to which the first facilitated transport film 54a is exposed are managed to suppress water absorption of the first facilitated transport film 54a. . That is, in the second aspect of the present invention, the application of the second facilitated transport film 54b (current facilitated transport film) is started after the drying of the first facilitated transport film 54a (previous facilitated transport film) is completed. By the time the composition is applied, it is preferable that the weight increase rate of the first facilitated transport film 54a due to water absorption is 40% by mass or less.
As an example, as described above, the conveyance path from the outlet of the drying unit 18 to the winding unit 20 and the winding unit 20 are surrounded by a housing, and the temperature and humidity in the housing are measured and managed, so that after drying The first facilitated transport film 54a is suppressed in water absorption to obtain a treated support roll 56R around which the treated support 56 is wound. Next, when the dried support transport film 54a has been dried by supplying the treated support roll 56R in which the water absorption of the first facilitated transport film 54a is suppressed to the formation of the second facilitated transport film 54b. Thus, it is preferable that the rate of weight increase due to water absorption of the first facilitated transport film 54a is 40% or less by the time when the coating composition for the second facilitated transport film 54b is applied.

  Similarly, in this method, it is possible to prevent moisture from adhering to the surface of the first facilitated transport film 54a, and to prevent the coating composition from repelling due to the moisture, and to cover the entire surface of the first facilitated transport film 54a. The coating composition can be applied uniformly to form a uniform second facilitated transport film 54b free from defects.

In the second aspect of the present invention, when the coating composition that becomes the second facilitated transport film 54b is applied under the condition that the weight increase rate due to water absorption of the first facilitated transport film 54a exceeds 40% by mass, Similarly to the above, it is not possible to sufficiently prevent moisture from adhering to the surface of the first facilitated transport film 54a, and the coating film of the coating composition is repelled to form a uniform second facilitated transport film 54b. Can not.
Moreover, under the condition that the weight increase rate due to water absorption of the first facilitated transport film 54a is 30% or less in terms of more suitably preventing moisture from adhering to the surface of the first facilitated transport film 54a. It is preferable to apply a coating composition that becomes the second facilitated transport film 54b.

Various methods can be used as the method of applying the coating composition under the condition that the weight increase rate due to water absorption of the first facilitated transport film 54a is 40% by mass or less.
As an example, in the formation of the second facilitated transport film, the temperature and / or humidity of the space to which the first facilitated transport film 54a is exposed until the coating composition is applied to the first facilitated transport film 54a. Is adjusted so that the rate of weight increase due to water absorption of the first facilitated transport film 54a is 40% by mass or less. That is, the temperature and / or humidity of the housing 26 in FIG. 1 and the space 46 and the space 48 in FIG. 3 are controlled so that the weight increase rate due to water absorption of the first facilitated transport film 54a is 40% by mass or less.
Moreover, between the supply part 12 and the application part 14 in the manufacturing apparatus 10 shown in FIG. 1, the upstream of the application part 14 in FIG. 3, and between the drying part 18a and the application part 14b, a heating means, a wind, etc. Water removal means (wiping means), suction means for sucking moisture, means for dehumidifying moisture, etc. are provided, and coating is performed under the condition that the weight increase rate due to water absorption of the first facilitated transport film 54a is 40% or less. A method of applying the composition can also be used.
Further, after the first facilitated transport film 54a is applied and dried, the film surface is protected with a protective film or the like, and the protective film or the like is peeled off immediately before the second facilitated transport film 54b is applied. A method of applying the coating composition under conditions where the weight increase rate of the film 54a due to water absorption is 40% or less can also be used.

Although the above example is the example which performed the manufacturing method of the acidic gas separation membrane of this invention using RtoR, this invention can utilize various manufacturing methods besides this.
For example, the first facilitated transport membrane 52a and the second facilitated transport membrane 52b are prepared in the same manner while conveying the cut sheet-shaped support instead of the long support 52, and the acidic gas separation membrane is formed. It may be produced.

Alternatively, the first facilitated transport membrane 52a and the second facilitated transport membrane 52b are prepared by a so-called batch-type (single-wafer) process without transporting the support to produce an acid gas separation membrane. May be.
Even in the batch-type treatment, for example, when the coating film thickness of the coating composition is adjusted, a shearing force is applied to the coating film, so that the same coating composition may be repelled. However, when forming the second layer (second layer and later) facilitated transport film 52b, the temperature and humidity of the space to which the first coating composition is exposed are measured until the coating composition is applied. By applying the coating composition under management, or by applying the coating composition under the condition that the weight increase rate due to water absorption of the first facilitated transport film 54a is 40% by mass or less, the coating composition is properly applied, A uniform facilitated transport film 52b can be formed.

  However, in the present invention, an acid gas separation membrane is manufactured using RtoR as shown in FIGS. 1 and 3 in that high productivity can be obtained and a uniform facilitated transport membrane can be formed. Is preferred.

  As mentioned above, although the manufacturing method of the acidic gas separation membrane of this invention was demonstrated in detail, this invention is not limited to the above-mentioned example, Even if various improvements and changes are performed in the range which does not deviate from the summary of this invention. Of course it is good.

  Hereinafter, the specific example of this invention is given and the manufacturing method of the acidic gas separation membrane of this invention is demonstrated in detail.

[Example 1]
<Preparation of coating composition>
A polyvinyl alcohol-polyacrylic acid copolymer (Kuraray Co., Ltd., Clastomer AP-20, 2.4% by mass) and a crosslinking agent (Wako Pure Chemical Industries, Ltd., 25% by mass glutaraldehyde aqueous solution), 0.01% by mass, are prepared. To this aqueous solution, 1M hydrochloric acid was added until the pH reached 1.7 to cause crosslinking.
After crosslinking, a 40% aqueous cesium carbonate solution (manufactured by Rare Metal Co., Ltd.) was added so that the concentration of cesium carbonate was 6.0% by weight. That is, in this example, cesium carbonate serves as a carrier for the facilitated transport film 54.
Furthermore, 0.003 mass% of surfactant (manufactured by NOF Corporation, 1 mass% Rapisol A-90) was added to prepare a coating composition.
<Production of acid gas separation membrane>

  A long (porous) support 52 having a width of 500 mm and a thickness of 200 μm (a laminate (manufactured by GE Corp.) obtained by laminating porous PTFE on the surface of a PP nonwoven fabric) is wound into a roll shape. A support roll 52R was prepared.

First, the support roll 52R was mounted on the rotating shaft 34 of the supply unit 12 of the manufacturing apparatus 10 shown in FIG. 1 so that the coating composition was applied to the porous PTFE side. Subsequently, the support body 52 is sent out from the support body roll 52R, and as described above, the support body 52 passes through the coating unit 14 and the drying unit 18 through a predetermined conveyance path to the winding unit 20 to wind up the tip of the support body 52. It was wound around the shaft 42.
On the other hand, a necessary amount of the prepared coating composition was filled in the coating device 36 of the coating unit 14.

After completing the above preparation, the support 52 is started to be transported, and as described above, the coating composition is applied to the surface of the support 52 in the coating unit 14, and the coating composition is dried in the drying unit 18. Then, the first facilitated transport film 54a is formed as the treated support 56, and the prepared treated support 56 is wound around the take-up shaft 42 to obtain a treated support roll 56R. The temperature / humidity measuring means 28 and the temperature / humidity adjusting means 30 are not activated.
The conveyance speed of the support body 52 was 3 m / min.
The coating composition was applied so that the coating thickness was 1 mm. The thickness of the coating composition is such that the facilitated transport film formed by drying has a thickness of 0.03 mm.
Furthermore, drying in the drying unit 18 was performed using a warm air drying furnace at multi-stage heating temperatures of 70 ° C., 80 ° C., 90 ° C., 100 ° C., 110 ° C., and 120 ° C.

When 100 m of the laminate 24 was produced, the conveyance of the support 52 was stopped and the processed support 56 was cut immediately downstream of the pass roller 40b. Next, the processed support 56 was wound up to the end, and the processed support roll 56 </ b> R was removed from the winding shaft 42.
Further, the support roll 52R and the support 52 remaining in the manufacturing apparatus 10 were also removed from the apparatus.

  After removing the treated support roll 56R, the support roll 52R, etc., the temperature / humidity measuring means 28 and the temperature / humidity adjusting means 30 are operated, and the temperature and humidity inside the housing 26 are measured by the temperature / humidity measuring means 28, According to the measurement result, the temperature and humidity were adjusted by the temperature / humidity adjusting means 30, and the temperature inside the housing 26 was controlled to 22 ° C. ± 3 ° C., and the humidity was controlled to 30% RH ± 5% RH.

Next, the treated support roll 56R removed from the winding shaft 42 was mounted on the rotating shaft 34 of the supply unit 12 of the manufacturing apparatus 10 so that the coating composition was applied to the first facilitated transport film 54a side. Next, similarly to the above, the processed support 56 was pulled out from the processed support roll 56 </ b> R, passed through the winding unit 20, and the tip was wound around the winding shaft 42.
Furthermore, a necessary amount of the prepared coating composition was filled in the coating device 36 of the coating unit 14.

After completing the above preparation, the second facilitated transport film 54b is formed in the same manner as the first facilitated transport film 54a (that is, the coating thickness of the coating composition of the second layer is 1 mm, and drying is performed). The subsequent film thickness was 0.03 mm), and the acidic gas separation membrane 50 was produced, wound around the take-up shaft 42, and the separation membrane roll 50R formed by winding the acidic gas separation membrane 50 of 60 m was produced.
That is, the acidic gas separation membrane 50 has a total thickness of 0.03 mm for the first (first layer) facilitated transport membrane 54a and 0.03 mm for the second facilitated transport membrane 54b. It has a facilitated transport membrane of 0.06 mm.

[Examples 2 to 5]
Example 2 except that the temperature inside the housing 26 was controlled to 25 ° C. ± 3 ° C. and the humidity was controlled to 40% RH ± 5% RH in the formation of the second layer facilitated transport film 54b (Example 2);
Example 2 except that the temperature inside the housing 26 was controlled to 18 ° C. ± 3 ° C. and the humidity was controlled to 45% RH ± 5% RH in the formation of the second layer facilitated transport film 54b (Example 3);
In the formation of the second facilitated transport film 54b, the temperature inside the housing 26 is controlled to 30 ° C. ± 3 ° C. and the humidity is controlled to 45% RH ± 5% RH (Example 4);
Except for controlling the temperature inside the housing 26 to 15 ° C. ± 3 ° C. and the same humidity to 25% RH ± 5% RH in the formation of the second layer facilitated transport film 54b (Example 5); Similarly, a separation membrane roll 50R was produced.

[Comparative Example 1]
A separation membrane roll 50R was produced in the same manner as in Example 1 except that the temperature and humidity in the housing 26 were not managed when forming the second facilitated transport membrane 54b.
The temperature inside the housing 26 was 23 to 30 ° C., and the humidity was 50 to 60% RH.

[Comparative Example 2]
In the formation of the first facilitated transport film 54a, a separation membrane roll 50R was produced in the same manner as in Example 1 except that the coating thickness of the coating composition was 0.005 mm.
The thickness of this coating composition is such that the facilitated transport film formed by drying has a thickness of 0.00015 mm. That is, the acidic gas separation membrane 50 has a total thickness of 0.00015 mm for the first (first layer) facilitated transport membrane 54 a and 0.03 mm for the second facilitated transport membrane 54 b. It has a facilitated transport membrane of 0.03015 mm.

[Comparative Example 3]
In the formation of the first facilitated transport film 54a, a separation membrane roll 50R was produced in the same manner as in Example 1 except that the coating thickness of the coating composition was 4 mm.
The thickness of the coating composition is such that the facilitated transport film formed by drying has a thickness of 0.120 m. That is, the acid gas separation membrane 50 has a total thickness of 0.120 mm for the first (first layer) facilitated transport membrane 54 a and 0.03 mm for the second facilitated transport membrane 54 b. It has a facilitated transport membrane of 0.150 mm.

[Comparative Example 4]
Separation in the same manner as in Example 1 except that the temperature inside the housing 26 is controlled to 5 ° C. ± 3 ° C. and the humidity is controlled to 20% RH ± 5% RH in the formation of the second layer facilitated transport film 54b. A film roll 50R was produced.

[Example 6]
In the formation of the first facilitated transport film 54a, the amount of cesium carbonate as a carrier contained in the coating composition is changed from 6.0% by mass to 1.0% by mass, and the second facilitated transport film 54b is formed. A separation membrane roll 50R was produced in the same manner as in Example 1 except that the temperature inside the housing 26 was controlled at 25 ° C. ± 3 ° C. and the humidity was controlled at 55-60% RH.
Under these conditions, the weight increase rate due to water absorption of the first facilitated transport film 54a from the treated support roll 56R to the application of the coating composition of the second facilitated transport film 54b was measured. %Met.

[Gas permeability test]
The acidic gas separation membrane 50 was pulled out from each separation membrane roll 50R and cut out at an arbitrary position to produce a circular acidic gas separation membrane 50 having a diameter of 47 mm. The circular acidic gas separation membrane 50 was sampled at four locations at intervals of 100 mm with respect to 500 mm in the width direction.
A permeation test sample (effective area 2.40 cm ² ) was prepared using two PTFE membrane filters (pore size 0.10 μm, manufactured by ADVANTEC) and sandwiching a cut-out circular acidic gas separation membrane 50 from both sides of the membrane.
A mixed gas of CO ₂ / H ₂ : 10/90 (volume ratio) was used as a test gas. This mixed gas was supplied to each produced permeation test sample under the conditions of a relative humidity of 70%, a flow rate of 100 ml / min, a temperature of 130 ° C., and a total pressure of 3 atm. 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 separation factor α was calculated from the ratio of the H ₂ permeation rate and the CO ₂ permeation rate, and evaluated as follows.
A: α ≧ 80 in all four places.
B: 10 <α <80 is included even at one place.
C: α ≦ 10 is included even at one location.
The results are shown in the table below.

As shown in the above table, the coating thickness of the coating composition in the formation of the first facilitated transport film 54a is 0.01 to 3 mm, and the temperature in the housing is set in the formation of the second facilitated transport film 54b. Examples 1 to 5 in which the humidity is controlled to 10 to 40 ° C. and the humidity to 10 to 50% RH, and Example 6 in which the weight increase rate due to water absorption of the first facilitated transport film 54a is 20% by mass, Also achieves a good separation factor. In particular, Examples 1 to 3 in which the temperature and humidity in the housing 26 are both controlled within a preferable range achieve an excellent carbon dioxide gas separation performance with a separation factor of 80 or more in all respects.
On the other hand, Comparative Example 1 and Comparative Example 4 in which either the temperature or humidity in the housing 26 exceeds the temperature of 10 to 40 ° C. and the humidity of 10 to 50% RH are the formation of the second layer facilitated transport film 54b. In this case, the first facilitated transport film 54a absorbs moisture, and this causes the coating composition of the second facilitated transport film 54b to be repelled, so that an appropriate facilitated transport film cannot be formed and the separation factor is increased. It is thought that it became low.
Furthermore, in the formation of the first facilitated transport film 54a, Comparative Example 2 in which the thickness of the coating film is less than 0.01 mm cannot form the first facilitated transport film 54a that expresses the intended function. In the formation of the facilitated transport film 54a, in Comparative Example 3 in which the thickness of the coating film exceeds 3 mm, the generation of defects due to mixing of bubbles and the like, and the drying of the coating film are insufficient, and the separation factor is low. It is thought that it has been.
From the above results, the effects of the present invention are clear.

  It can be suitably used for the production of an acid gas separation membrane used for the production of hydrogen gas or the purification of natural gas.

DESCRIPTION OF SYMBOLS 10 Manufacturing apparatus 12 Supply part 14 Application | coating part 18 Drying part 20 Winding part 26 Housing 28 Temperature / humidity measuring means 30 Temperature / humidity adjusting means 34 Rotating shaft 36 Coating apparatus 38 Backup roller 40a, 40b, 40c, 40d, 40e Pass roller 42 Winding Axis 46, 48 Space 50 Acid gas separation membrane 50R Separation membrane roll 52 (Porous) support 52R Support roll 54a, 54b Promoted transport membrane 56 Treated support 56R Treated support roll

Claims (14)

The surface of the porous support contains a carrier that reacts with an acid gas and a hydrophilic compound for supporting the carrier , the temperature is 15 to 35 ° C., and the viscosity is 0.1 to 5 Pa · sec. An initial film forming step of forming the first facilitated transport film by applying the coating composition so that the film thickness is 0.01 to 3 mm and drying the applied coating composition;
The surface of the facilitated transport film formed in advance contains a carrier that reacts with an acidic gas and a hydrophilic compound for supporting the carrier , the temperature is 15 to 35 ° C., and the viscosity is 0.1 to 5 Pa. Applying a coating composition that is sec, and drying the applied coating composition to form a facilitated transport film, and one or more laminated film forming steps;
And in the laminated film forming step, the temperature and humidity of the space to which the facilitated transport film formed in the previous step is exposed before applying the coating composition are measured, and the temperature is 10 to 40 ° C., A method for producing an acidic gas separation membrane, wherein the temperature and humidity of the space are controlled so that the humidity is 10 to 50% RH.   From the workpiece roll formed by winding a long workpiece, the workpiece is sent out, processed while being conveyed in the longitudinal direction, and the processed workpiece is wound into a roll and processed. The method for producing an acidic gas separation membrane according to claim 1, wherein a roll-to-roll system is used as a roll. The initial film forming step or further one or more of the laminated film forming steps while feeding the porous support from a support roll formed by winding the porous support and transporting the porous support in the longitudinal direction After that, the processed object to be processed is wound into a roll shape to form a processed roll, and then the processed object to be processed is sent out from this processed roll to perform the laminated film forming step. ,
When the processed object to be processed is sent out from the processed roll and the laminated film forming step is performed, the space in which the processed roll for supplying the processed object to be processed exists, and the coating composition is applied. The method for producing an acid gas separation membrane according to claim 2, wherein the temperature and humidity are managed in a space where the facilitated transport membrane is exposed.   In the initial film forming step and the laminated film forming step, the temperature and humidity of the space to which the formed facilitated transport film is exposed from the drying of the coating composition to the winding of the processed object to be processed in a roll shape. The method for producing an acidic gas separation membrane according to claim 2 or 3, wherein the temperature and humidity of the space are managed so that the temperature and humidity are within a predetermined range by measurement. The acidic gas separation membrane according to any one of claims 1 to 4 , wherein the coating composition in the initial film forming step and the coating composition in at least one of the laminated film forming steps are the same composition. Production method. The acidic gas separation membrane according to any one of claims 1 to 5 , wherein the coating composition in the initial film forming step and the coating composition in the laminated film forming step at least once are different compositions. Production method. 7. The coating composition according to claim 1 , wherein the coating composition contains cesium carbonate as the carrier, polyvinyl alcohol-polyacrylic acid copolymer as the hydrophilic compound, and further contains a crosslinking agent. The manufacturing method of the acidic gas separation membrane of description. The surface of the porous support contains a carrier that reacts with an acid gas and a hydrophilic compound for supporting the carrier , the temperature is 15 to 35 ° C., and the viscosity is 0.1 to 5 Pa · sec. An initial film forming step of forming the first facilitated transport film by applying the coating composition so that the film thickness is 0.01 to 3 mm and drying the applied coating composition;
The surface of the facilitated transport film formed in advance contains a carrier that reacts with an acidic gas and a hydrophilic compound for supporting the carrier , the temperature is 15 to 35 ° C., and the viscosity is 0.1 to 5 Pa. Applying a coating composition that is sec, and drying the applied coating composition to form a facilitated transport film, and one or more laminated film forming steps;
And in the said laminated film formation process, the said coating composition is apply | coated on the conditions from which the weight increase rate by the water absorption of the said facilitated-transport film | membrane formed at the previous process will be 40 mass% or less. A method for producing an acidic gas separation membrane. From the workpiece roll formed by winding a long workpiece, the workpiece is sent out, processed while being conveyed in the longitudinal direction, and the processed workpiece is wound into a roll and processed. The method for producing an acidic gas separation membrane according to claim 8 , wherein a roll-to-roll method is used. The method for producing an acidic gas separation membrane according to claim 8 or 9 , wherein the coating composition in the initial film forming step and the coating composition in the laminated film forming step at least once are the same composition. The acidic gas separation membrane according to any one of claims 8 to 10 , wherein the coating composition in the initial film forming step and the coating composition in at least one of the laminated film forming steps are different compositions. Production method. In the laminated film forming step, the weight increase due to water absorption of the facilitated transport film formed in the previous step is controlled by controlling at least one of the temperature and humidity of the space where the facilitated transport film on which the coating composition is applied is present. The method for producing an acidic gas separation membrane according to any one of claims 8 to 11, wherein the coating composition is applied under a condition that the rate is 40% by mass or less. The coating composition according to any one of claims 8 to 12 , further comprising a cesium carbonate as the carrier, a polyvinyl alcohol-polyacrylic acid copolymer as the hydrophilic compound, and a crosslinking agent. The manufacturing method of the acidic gas separation membrane of description. In the initial film forming step and the laminated film forming step, the temperature and humidity of the space to which the formed facilitated transport film is exposed from the drying of the coating composition to the winding of the processed object to be processed in a roll shape. The method for producing an acidic gas separation membrane according to any one of claims 9 to 13 , wherein the temperature and humidity of the space are managed so that the temperature and humidity are in a predetermined range by measurement.