JPH01224027A - Steam permselective membrane - Google Patents

Abstract

PURPOSE:To selectively permeate steam by using a hydrocarbonic ion-exchange membrane having >=40wt.% water absorption, <=6N fixed ion concn., and 0.1-150mum thickness, and contg. 1.5-5.0mm equiv./g resin. CONSTITUTION:When a hydrocarbonic ion-exchange membrane consisting of the sulfonate of a copolymer of aromatic polysulfone/polythioether, etc., expressed by formula I is used, for example, as a steam permselective membrane, the water absorption is controlled to >=40wt.% from the standpoint of the membrane strength and steam permeation rate, the fixed ion concn. to <=6N, the membrane thickness to 0.1-150mum, and the ion exchange capacity to 1.5-5.0mm equiv./g resin from the standpoint of the steam permeation rate and selectivity. When the membrane fulfilling said conditions is used, excellent steam permselectively, namely >=50 or preferably >=80m<3>/m<2>.hr.atm. steam permeation rate and >=500 or preferably >=1,000 steam/nitrogen permselectivity coefficient, is exhibited.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a separation membrane that permeates and separates specific components from a mixed fluid using the membrane.

More specifically, we manufacture air with reduced humidity such as air conditioning for buildings and compressed air for instrumentation, remove moisture from natural gas,
In addition, water and steam are selected from gases containing moisture in the production of humidity-controlled gases used in a wide range of fields, including the chemical industry, electrical and electronic industries, precision machinery industry, food industry, and textile industry. This invention relates to a separation membrane that allows water to pass through the membrane.

[Prior art] Methods for removing water vapor from gas can be broadly classified into (1)
Compression method, (2) cooling method, (3) adsorption method.

(4) Four membrane separation methods are known.

The membrane separation method is a method in which a gas containing water vapor is brought into contact with one side of a diaphragm, and water vapor is selectively permeated and separated from the other side.In principle, compared to the other three methods, running costs are lower and equipment is required. Although it has advantages such as a simple structure and the ability to continuously obtain dry gas without contaminating the gas, it has rarely been put into practical use because there is currently no diaphragm with excellent water vapor permeability.

For example, JP-A-53-97246. Japanese Unexamined Patent Publication No. 54-1) 4
81° Japanese Patent Publication No. 54-152679. JP-A-60-183
025. 7. Japanese Unexamined Patent Publication No. 61-1951) Japanese Patent Publication No. 52-42
723 describes dehumidifying membranes made of water-absorbing polymer membranes and membrane materials with high gas permeability used for oxygen separation and hydrogen separation, but the amount of water vapor permeation is small, and the separation coefficient between water vapor and gas is also low. Not enough.

In addition, for the purpose of improving water vapor permeation and membrane strength, composite membranes using the above membrane materials as thin films, such as polysulfone porous membranes, polypropylene porous membranes, and polytetrafluoroethylene porous membranes, have been proposed in JP-A-53-86684 and JP-A-Sho. 60-257819
．． JP-A-60-261503° JP-A-62-42772
Although the membrane strength of these membranes has been improved, the water vapor permeation rate is not sufficient and the water vapor selective permeability coefficient is also small.

On the other hand, it is used in diaphragms for fuel cells and diaphragms for electrolysis.
Perfluoro ion exchange membranes containing sulfonic acid groups in their side chains are considered effective as dehumidifying membrane materials because of their high water absorption and high water permeation rate through the polymer. The dehumidifier used is described in CI SP 3735558 and is available as Perma Pure Dry 8. However, since this method has a small amount of water vapor permeation, it has the disadvantage that it cannot be used as a substitute for conventional refrigeration or adsorption methods in industrial applications that process large amounts of gas.

Furthermore, JP-A-62-7417 describes a dehumidifying membrane that produces a gas with a low dew point temperature by heat-treating hollow fibers made of perfluorosulfonic acid polymer. has the disadvantage that the water vapor transmission rate is significantly reduced because of the removal of In addition, these perfluorosulfonic acid polymers are very expensive due to their difficult manufacturing process and special characteristics, so the separation membranes obtained must also be expensive. It also has the disadvantage that it cannot be used for general-purpose dehumidification applications that require membranes.

[Problems to be solved by Suimei] The present invention solves the above-mentioned drawbacks of the prior art, and provides an inexpensive water vapor that has a higher water vapor permeation rate and water vapor selective permeability coefficient. The purpose is to provide a selectively permeable membrane.

An object of the present invention is to provide a dehumidifying membrane that can replace the production of compressed air for air conditioners and instrumentation using conventional techniques, and can also be used for dehumidifying natural gas, dehumidifying corrosive gases that cannot be used with conventional techniques, etc. do.

[Means for Solving the Problems] The above object of the present invention is to achieve a water absorption rate of 40% by weight or more.1. Water vapor selective permeability characterized by comprising a hydrocarbon-based ion exchange membrane with a fixed ion concentration of 6N or less, a membrane thickness of 0.1 to 100 μm, and an ion exchange capacity of 1.5 to 4.5 milliequivalents/g resin. This is accomplished by a membrane.

The water vapor selectively permeable membrane of the present invention is basically constituted by the above-mentioned specific ion exchange membrane, and is based on novel ideas and knowledge that have not existed before.

That is, as a conventionally known water vapor selective permeation membrane containing an ion exchange group, the above-mentioned tJsP 373555
8. As seen in JP-A No. 62-7417, there is a copolymer film of perfluorovinyl ether and tetrafluoroethylene having a sulfonic acid group in the side chain. These perfluorosulfonic acid membranes have high water absorption and a high diffusion rate of water within the polymer, so it is said that these properties can be used to dry various gases.

(Takaomi Satoyo, “Functional Polymers” published by Nikkan Kogyo Shimbun, p1391) On the other hand, typical hydrocarbon-based ion exchange membranes include:
Sulfonated membranes of styrene-divinylbenzene copolymer and chloromethylated quaternary ammonium chloride membranes are known for seawater concentration.

It is used as a diaphragm for electrodialysis and diffusion dialysis for brine desalination, etc., but these were originally developed as membranes with high selective permeability for ions and low permeability for water. , it cannot be used as a water vapor selectively permeable membrane.

As a result of extensive research into membranes with a high water vapor permeation rate and selective permselectivity, the present inventors discovered that a specific hydrocarbon-based ion exchange membrane can provide water vapor permeability equivalent to that of a perfluorosulfonic acid membrane.

As the water vapor selective permeation membrane of the present invention, an ion exchange membrane having a fixed ion concentration of 1 to 6N is used. The fixed ion concentration is expressed in ion exchange group equivalents per 1000 g of water fed to the membrane. In conventional ion-selective ion-exchange membranes, membranes with a high fixed ion concentration are used based on Donnan's equilibrium ion selectivity, and usually, a fixed ion concentration of 6N or more is preferably used.

The present inventor's research shows that when the fixed ion concentration exceeds 6N, the water vapor permeation rate decreases significantly, and when the fixed ion concentration exceeds 6N, the water vapor permeation rate decreases significantly. Ion exchange membranes with a fixed ion concentration of 1 to 6N, especially 2 to 5N, have a lower water vapor permeation rate and water vapor selectivity, including saponification membranes made of cellulose or polyacrylonitrile. Preferred from the viewpoint of balance between speed and permselectivity. Here, the selective permselectivity of water vapor is expressed as the ratio a of the permeation rate of water vapor to the permeation rate of other gases such as nitrogen, oxygen, methane, etc.

It is not clear why the fixed ion concentration is important for water vapor permeability, but it is probably due to the following reasons.

The water in the ion exchange membrane has different properties from normal water due to the interaction with the ion exchange groups, and depending on the strength of the interaction, unfreeze water, restricted water, and free water can exist. It is believed that

When the fixed ion concentration is 6N or more, the adsorbed water is tightly bound to the ion exchange group, and the movement of water within the membrane is reduced.
It is explained that when the fixed ion concentration is below IN, there is a large amount of free water and other gases permeate through the free water layer, resulting in a decrease in the water vapor separation coefficient. As will be described later in Examples, water-absorbing polymers that do not contain ion exchange groups, such as vinylon film and acrylamide bisacrylamide membrane,
Although the water absorption is high, the water permeation rate is low, so it is thought that the presence of ion exchange groups promotes the water diffusion rate. However, such explanations are provided to aid understanding of the present invention, and are not intended to limit the present invention in any way.

In addition to the fixed ion concentration of 1 to 6N in the water vapor selectively permeable membrane of the present invention, the water absorption rate is 40% by weight or more and the membrane thickness is in a specific range. Necessary to obtain high film thickness. Water absorption rate is 40
If the water vapor transmission rate is less than 50% by weight, the water vapor transmission rate is insufficient.
If it exceeds 0% by weight, the film strength decreases, so the water absorption rate is 4.
A content of 0 to 500% by weight, particularly 50 to 250% by weight, is preferable because a water vapor permselective membrane having practical strength for module production and use can be obtained. The membrane thickness can be made as thin as possible in order to increase the water vapor permeation rate, but in the water vapor permeable membrane of the present invention, the water vapor permeation rate is not inversely proportional to the membrane thickness, and there is a relationship as shown in the following equation. .

Q, = A + B/l where Q: Water vapor permeation rate, t: Film thickness A and B are the characteristic values of the membrane.On the other hand, the permeation rate of gases other than water vapor, such as nitrogen, oxygen, and methane, is inversely proportional to the membrane thickness. Excessive reduction in film thickness is not preferable, since reduction in thickness leads to a reduction in water vapor selective permselectivity. Furthermore, if the film thickness is excessively thick, there is a drawback that even if humid gas is dehumidified, a highly dry gas cannot be obtained, although the water vapor transmission rate is not significantly reduced. Thus, the thickness of the water vapor permselective membrane is preferably from 0.1 to 150 μm, particularly from 1 to 80 μm, from the viewpoint of water vapor permeation rate, permselectivity, and low humidity gas production.

To explain the present invention in more detail below, the water vapor permselective membrane of the present invention can be used without any restrictions as long as it has the above-mentioned physical properties in fixed ion concentration, water absorption rate, and membrane thickness.

Types of ion exchange groups include cation exchange groups such as sulfonic acid, sulfonate, carboxylic acid, carboxylate, phosphoric acid, phosphate, acidic hydroxyl, and acidic hydroxyl, as well as primary to tertiary amine groups. Examples include anion exchange groups such as , quaternary ammonium groups, among others, sulfonic acids have high water absorption,
Further, since the water vapor permeability is high, a sulfonic acid-containing membrane having an ion exchange capacity of 1.5 to 5.0 meq/g resin is preferably used.

The material for the sulfonic acid-containing membrane may be cellulose, polyolefin, acrylic, vinyl acetate, polystyrene, polysulfone, etc. without any restrictions.

The method for introducing sulfonic acid groups into these materials is as follows:
Concentrated sulfuric acid.

A method of directly introducing a sulfonic acid group using a sulfonating agent such as fuming sulfuric acid, chlorsulfonic acid, or anhydrous sulfuric acid/triethyl phosphate complex, impregnation polymerization, graft polymerization using a monomer containing a sulfonic acid group or into which a sulfonic acid group can be introduced. For example, sulfonated styrene sulfonic acid grafted cellulose membranes, chlorosulfonated polyethylene membranes, sulfonated polyethylene-propylene copolymer membranes, sulfonated styrene-divinylbenzene copolymer membranes, and styrene monomer polyethylene membranes are applied. Examples include sulfonated membranes of vinyl chloride-impregnated polymer membranes, sulfonated membranes of polyolefin-based graft polymerization membranes of styrene-based monomers, and sulfonated polysulfone-based membranes.
From the viewpoint of chemical resistance and moldability, sulfonated polysulfone membranes are preferably used, and in particular, carbon 1-8 hydrocarbon groups with different general formulas, a-d are 0-4, e are 0-3, f+g are 0- 7, h+l is O~5, RIO, R
1) is hydrogen, a hydrocarbon group having 1 to 6 carbon atoms, X is halogen or -S II, m/n = 100/l to l/1
Indicates 0. The sulfonated membrane of aromatic polysulfone/polythioether copolymer represented by ) is used because the above-mentioned fixed ion concentration, water absorption rate, and membrane thickness can be easily controlled and manufactured.

That is, the above copolymer not only has the mechanical strength, heat resistance, and chemical resistance of an aromatic polysulfone resin and the moldability of an aromatic polythioether resin, but also has at least one - Since it contains a S H group, this reactive group can be used to increase the molecular weight and obtain crosslinked products.In addition, during sulfonation, the sulfonic acid group
As a result of easy introduction into the benzene nucleus of O-, the ion exchange capacity can be easily controlled, and a block copolymer consisting of a hydrophilic segment into which an ion exchange group is introduced and a hydrophobic segment without an ion exchange group is obtained. It was discovered that the film has the characteristic that even if the water absorption rate is high, a strong film with high mechanical strength can be obtained.

Such an aromatic polysulfone-polythioethersulfone copolymer is disclosed in Japanese Patent Application Laid-Open No. 61-7202 by the present applicant.
0. JP-A-61-76523 and JP-A-61-168
It can be obtained by the method described in No. 629.

As a method for obtaining a water vapor permselective membrane in the present invention, for example, the following method is used.

(1) A method in which the polysulfone copolymer is molded, then crosslinked if necessary, and then sulfonated. (2) A method in which the polysulfone copolymer is molded, then sulfonated, and then cured. (3) The polysulfone copolymer is Molding after sulfonating the polymer,
Among the methods for curing if necessary, methods that allow easy control of the sulfonation reaction and curing reaction (
3) is preferable, and in particular, a method in which a mixture of sulfonated polysulfone and a curing agent is added as necessary is made into a solution, and then cast film is formed is suitable for improving thin film formability and composite film formation with other porous supports. It is preferably used because it is easy to obtain.

Methods for sulfonating polysulfone copolymers include concentrated sulfuric acid, 9 fuming sulfuric acid, and chlorosulfonic acid.

This can be carried out by bringing the polysulfone copolymer into contact with a sulfonating agent such as sulfuric anhydride or sulfuric anhydride-triethyl phosphate complex. For example, by dissolving a polysulfone copolymer in a halogenated hydrocarbon such as trichloroethane or tetrachloroethane, adding a sulfonating agent to the solution, and conveniently selecting the reaction temperature and reaction time, a sulfone having a desired ion exchange capacity can be obtained. A polysulfone copolymer is obtained. However, the ion exchange capacity is 1.
Below 0 N/g resin, the water absorption is low and the water vapor transmission rate is low. Further, if the ion exchange capacity is 3.5 to 3.5 milliequivalent/g or more, the mechanical strength of the obtained membrane will be significantly reduced. The reaction is carried out in such a way that a sulfonated polysulfone copolymer of 3.0 meq mm/g resin is obtained.

When using the above-mentioned sulfonated polysulfone copolymer as the water vapor permselective membrane of the present invention, the copolymer can be used alone in the form of a membrane or hollow fiber.
Add a cured product as necessary, change the fixed ion concentration and water absorption rate, and control the water vapor permeation rate and permselectivity.
It is also possible to obtain a water vapor selectively permeable membrane with improved mechanical strength and chemical resistance.

Such a curing agent can be used without any problem as long as it reacts with the functional group contained in the polysulfone copolymer and has a stable crosslinked structure. It is preferable to use a curing agent that has a high molecular weight or a crosslinked film without impairing the mechanical properties of the polysulfone resin.

Examples of such curing agents include epoxy compounds having two or more epoxy groups such as bisphenol A diglycidyl ether, aminoblast resins such as hexamethoxymethyl melamine, and Fe (acetylacetonate)3. Compounds having two or more isocyanates such as metal acetylacetonate and modified hexamethylene diisocyanate isocyanurate;
FeCl3. Group 1 or group 1 represented by CuC1z
A polyfunctional maleimide compound containing two or more maleimide groups, typified by Group B metal halides and bismaleimide, can be used.

The mixture in which 0 to 100 parts by weight, preferably 0 to 50 parts by weight, of a curing agent is added to 100 parts by weight of the sulfonated polysulfone polymer includes dimethylacetamide, dimethylformide, dimethyl sulfoxide, triethyl phosphate, N-methylpyrrolidone, etc. The polymer solution was dissolved in a polar solvent or a mixed solvent containing them, and the polymer solution was cast into a convenient shape, and the solvent was removed to form a flat film-like nine-bag shape,
Water vapor selectively permeable membranes can be obtained in various forms, such as hollow fiber-like membranes and composite membranes with porous substrates.

Also, when the solvent is removed by heat treatment,
On the other hand, while only the surface of the water vapor selectively permeable membrane is dried, the remaining solvent is extracted, particularly preferably the poor solvent of the polymer is extracted, so that the surface has a dense skin structure. It is also possible to obtain a porous water vapor permselective membrane having the following properties.

The water vapor selectively permeable membrane of the present invention has a thin film of the above-mentioned specific hydrocarbon-based ion exchange membrane,
Composite formation with a porous base material having a thickness of 10 to 500 μm is an extremely preferable method for obtaining a membrane with excellent water vapor permeability and high mechanical strength. In such a composite membrane, it is important that the surface of the porous substrate and the inner walls of the pores have hydrophilicity. The reason why the pore inner walls of a porous substrate must be hydrophilic is not necessarily clear, but when using a porous substrate that does not have hydrophilicity, the water vapor permeation rate of the ion exchange membrane alone compared to 1/
On the other hand, it has been found that when a porous substrate coated with a hydrophilic layer is used, the water vapor permeation rate is further improved compared to using an ion exchange membrane alone.

The porous base material is selected based on the balance of various properties such as smoothness of the base material surface, heat resistance, moisture resistance, chemical resistance, and mechanical strength, and is made of polypropylene nonwoven fabric, polyester nonwoven fabric, and mutually bonded by fine fibers. Preference is given to porous polyethylene, porous polypropylene, porous polytetrafluoroethylene, which are made by stretching and have a microstructure consisting of separated knots. In addition, laminated porous substrates of microporous membranes and woven fabrics, or microporous membranes and nonwoven fabrics, have good moldability with ion-exchange thin membranes, and have excellent mechanical properties, especially pressure resistance. Therefore, it is particularly preferable.

A hydrophilic layer is preferably attached to such a porous substrate before or after lamination with an ion exchange membrane. Examples of the hydrophilic layer include surfactants, water-soluble polymers, water-absorbing polymers, etc., and the effect of improving the coating durability of the hydrophilic layer and the water vapor transmission rate by providing the hydrophilic layer is particularly large. Water absorption rate 40
An ion exchange resin containing % Shigesato or more is preferable.

The hydrophilic layer can be formed by impregnating a porous base material with an ion exchange resin monomer and polymerizing it to coat the inner walls of the pores of the porous base material, or by impregnating a solution of an ion exchange resin into the pores and drying it. , is preferred from the viewpoint of ease of manufacture. The hydrophilic layer coated on the inner walls of the pores has an amount of 0.1 to 5 of the pore volume of the porous base material.
0% by volume, preferably 0.5-10% by volume.

The method of combining a porous base material and an ion exchange membrane is to form an ion exchange resin into a membrane and then laminate it with a porous base material.
A method of impregnating a porous substrate with an ion exchange resin as a solution, a suspension solution, an emulsion polymerization latex, or an organic dispersion in which the water of the emulsion polymerization latex is replaced with an organic solvent, and drying the ion exchange resin. An example of the method is to apply and polymerize a convertible material onto the surface of a porous substrate.

In particular, when a hollow porous substrate is used, a water vapor selectively permeable hollow fiber with high permeability can be obtained by impregnating the hollow fiber with the above-described ion exchange resin solution and drying it.

In the membrane thus obtained, if no ion exchange group is introduced, a sulfonic acid group is preferably introduced, particularly preferably -SO,l (type).

In the present invention, in order to make the ion exchanger layer of the obtained water vapor permselective membrane have a specific fixed ion concentration and water absorption rate, it may be important to perform a certain specific treatment on the obtained membrane. many.

For example, when a sulfonated polysulfone polymer membrane is obtained from a polymer solution by casting and heat treatment, hot water treatment at 70° C. or higher is preferred.

In any case, by conveniently selecting the treatment conditions so that the ion exchanger layer has the fixed ion concentration and water absorption rate of the present invention, the water vapor permeation rate can be increased to 50rrf'/rrl.
', hr, atm preferably 80rrl'/
rn”.

hr, arm or more, selective permeability coefficient of water vapor/nitrogen is 5
000, preferably 10,000 or more, is obtained.

Next, the present invention will be explained with reference to examples, but the present invention is not limited to these examples.

Prior to the examples, various measurement methods used in the following examples will be summarized.

(1) Measurement of water absorption W An ion exchanger layer manufactured under the same conditions as the membrane to be measured for permeability, or an ion exchanger layer sampled from a part of the membrane to be measured, was immersed in pure water at 25°C. Membrane weight i'it W 1. It is determined from the following formula based on the dry membrane weight W2 obtained by vacuum drying the ion exchanger layer.

W = 100 (W, -Wa)/W2 (2) Calculation of fixed ion concentration Aw From the ion exchange capacity (meq/g resin) AR and the above water absorption rate W, it is determined by the following formula.

A, =A, / (W/+00) (3) Water vapor transmission rate Q (rn' (STP) /
Calculate the water vapor permeation rate with 100% purity using the device shown in Figure 1.

(4) Water vapor selective permeability a The permeation rate QA of gas A is determined using a Seikagaku-style gas permeation measuring device, and calculated using the following formula.

QA = Q/QA [Example] Example 1 4,4'-diphenol and dihalodiphenylsulfone were reacted in the same manner as the synthesis method described in JP-A-61-168629 to form an aromatic polysulfone unit. Then, the precursor was reacted with dihalodiphenylsulfone and sodium sulfate to obtain an aromatic polysulfone-polythioethersulfone copolymer A represented by the following formula.

m/n = ] / 1 Intrinsic viscosity 0.65 Next, the copolymer A was dissolved in 1,1.2-trichloroethane, and then sulfuric anhydride/triethyl phosphate was dissolved in 2
/1 molar ratio of the complex in a trichloroethane solution;
One unit of copolymer A was brought into contact with 25 parts of the complex and reacted at 25°C for 43 hours, followed by washing and drying. The ion exchange capacity of the obtained sulfonated copolymer A was 1.85 meq/g resin.

The thus obtained sulfonated copolymer A was dissolved in N-methylpyrrolidone to obtain a solution with a solid content concentration of 20% by weight. Next, the polymer solution was spread on a glass plate, dried, and then heated at 170°C for 2 hours to form a film with a thickness of 70μ.
A film of m was obtained.

Next, the above membrane was divided into four parts and each part was heated at 70°C in pure water.
, 100°C, 120°C, and 140°C.

After air-drying the four types of membranes thus obtained, the water absorption rate, water vapor permeation rate, and water vapor/nitrogen selective permeation coefficient were determined. The results are shown in Table 1 and Figure 2.

Comparative Example 1 The water absorption rate and water vapor permeability were measured in exactly the same manner as in Example 1, except that the obtained membrane was not subjected to hot water treatment. The results are shown in Table 1 and Figure 2.

Table 1 Example 2 The aromatic polysulfone-polythioethersulfone copolymer A obtained in Example 1 was sulfonated to produce a sulfonated copolymer A2 with an ion exchange capacity of 1.05 mm/g resin.
．． Sulfonated copolymer A3 with an ion exchange capacity I of 1.52 milliliter/g resin and an ion exchange capacity ff12. −
A sulfonated copolymer A4 of 0.05 mm fit/g resin was obtained.

One part of the Na salt type sulfonated copolymer of the above 3FJs was dissolved in N-methylpyrrolidone, the solution was cast on a glass plate, and the solution was heated at 300°C. 1 hour. Heat, film thickness 70μm
The membrane thus obtained was then immersed in a 0.5N hydrochloric acid solution to form an acid form, and then treated with hot water in pure water.

Water absorption rate of the membrane thus obtained. Water vapor transmission rate.

I asked for The results are shown in Table-2.

Comparative Example 2 The water absorption rate was determined in the same manner as in Example 2, except that a sulfonated polysulfone copolymer with an ion exchange capacity of 0.6 meq/g resin was used. The water vapor transmission rate was determined. The results are shown in Table-2.

Comparative Example 2 The water absorption rate was determined in the same manner as in Example 2, except that a sulfonated polysulfone copolymer with an ion exchange capacity of 0.6 meq/g resin was used. The water vapor transmission rate was determined. The results are shown in Table-2.

Table 2 Example 3 N of the sulfonated polysulfone copolymer obtained in Example 1
-Methylpyrrolidone solution with pore size of 0 and 1μ and porosity of 70
%, was coated on one side of a polytetrafluoroethylene porous membrane having a film thickness of 70 μm, and was heat-treated to cover it with a sulfonated polysulfone film having a thickness of 10 μm.

Divide the stuffed belly into two, leave one piece as is, and use the remaining 1 piece of PT.
On the FE side, a solid content concentration of 1 consisting of a mixture of sulfonated polysulfone, N-methylpyrrolidone, and isopropanol water is added.
The solution was impregnated with the PTFE porous material and dried to coat the inner walls of the pores of the PTFE porous material with the sulfonated polysulfone copolymer.

The amount of adhesion was 0.6 g/rn'.

After treating the two types of membranes thus obtained with hot water at 100°C, the water vapor permeation rate. The water vapor/methane selectivity coefficient was determined. The results are shown in Table-3.

Table 3 Example 4 A 50 μm thick high-quality polyvinyl chloride film was impregnated with a monomer solution of 3% by weight of shihinylbenzene, 97% by weight of styrene, and 1% by weight of azobisisobutylnitrile, and polymerized at 70°C. . The impregnation ratio was 1) 0% by weight based on the vinyl chloride film.

The above-mentioned impregnated polymer membrane was sulfonated in 98% by weight concentrated sulfuric acid to obtain a membrane with an ion exchange capacity of 2.16 meq/g.

The membrane thus obtained had a water absorption rate of 55% by weight, a fixed ion concentration of 5ON, and a water vapor permeation rate Q of 72g/m', hr, a.
It was tm.

Comparative Example 3 As a result of measuring the water absorption rate and water vapor permeation rate of a vinylon film with a thickness of 65 μm, which is a polyvinyl alcohol acetal film that does not contain ion exchange groups but has a high water absorption rate,
Each 151%, +4rrf'/m", hr, atm
Met.

[Brief explanation of the drawings] Figure-1 is a schematic diagram of the water vapor transmission rate measuring device. Figure-2
shows the relationship between water vapor permeation rate and fixed ion concentration, and between water vapor permeation rate and water absorption rate in Example 1 and Comparative Example 1. Drawing focus No. 1 Figure 1--Y'I < Incense, Qi 21ze f peeling
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-7 (＜Koki 1f!J hill sword meter l2--1 椭摵 4 連 Ｇａｎｄ inkstone 3--- teε廿''j 2 side kashi η needle /3-A＜za, support (4
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1 summer t, > 1 < Yumo Dojiguchi Kunisada on ring 7 yen OJ) hi JJJJ ≦ (W shi 5) Procedure book (forced audience 1, case indication 1988 Patent Application No. 45935 2) Name of the invention Relationship to the case of a person who corrects water vapor selectively permeable membrane 3 sleeves Patent applicant address 2-1-2 Marunouchi, Chiyoda-ku, Tokyo Name
(004) Asahi Glass Co., Ltd. Number of inventions increased by 6 spontaneous amendments based on the notice of reasons for refusal dated May 31, 1988 (shipment date) None 7 Subjects of sleeve correction

Claims (4)

[Claims] (1) Water absorption rate is 40% by weight or more, fixed ion concentration is 6
A water vapor selectively permeable membrane comprising a hydrocarbon-based ion exchange membrane containing N or less, a membrane thickness of 0.1 to 150 μm, and an ion exchange capacity of 1.5 to 5.0 milliequivalents/g resin. (2) Claim (1) characterized in that the hydrocarbon-based ion exchange membrane is composed of a sulfonated polysulfone-based membrane.
) Water vapor selectively permeable membrane (3) Hydrocarbon-based ion exchange membranes have a general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (However, Ar in the formula ▲ There are mathematical formulas, chemical formulas, tables, etc.)
, ▲There are mathematical formulas, chemical formulas, tables, etc.▼ ▲There are mathematical formulas, chemical formulas, tables, etc.▼, Y is a single bond, -
O-, -S-, -SO_2-, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, R_
1 to R_9 are the same or different carbon 1 to 8 hydrocarbon groups, a to d are 0 to 4, e is 0 to 3, f + g is 0 to 7
, h+i is 0 to 5, R_1_0, R_1_1 are hydrogen,
A hydrocarbon group having 1 to 6 carbon atoms, X is halogen or -SH,
Indicates m/n=100/1 to 1/10. Claims 1.
) or water vapor selectively permeable membrane of (2) (4) The hydrocarbon-based ion exchange membrane has a pore size of 0.01 to 10
0 μm, thickness of 10 to 500 μm, and a water vapor selective permselectivity according to claims (1) to (3), characterized by comprising a composite membrane laminated with a porous layer made of a porous base material having hydrophilic properties. film