JPS6026141B2 - Cation exchange resin membrane - Google Patents

Description

Detailed Description of the Invention The present invention provides an intestinal ion exchange resin membrane comprising a porous organic substance, preferably a porous fluorine-containing polymer compound, as a reinforcing material and a cation exchanger resin component having fluorine atoms bonded thereto. In particular, the reinforcing material is characterized in that the structural unit thereof is a fluorine-containing vinyl monomer to which an intestinal ion exchange group or a derivative thereof is bonded.

Ion exchange membranes are used for electrodialysis, diffusion dialysis, electrode reaction,
It is widely used in various fields such as ultrafiltration, reverse osmosis, etc.
Generally, various reinforcing materials are used because of the need for ease of handling, stable performance, dimensional stability, etc.

In general, the ion exchange resin component of the ion exchange membrane is relatively stable thermally and against organic chemicals, acids, alkalis, and oxidizing agents, but each reinforcing material has its own drawbacks and no one is perfect. For example, ion exchange membranes for electrodialysis that are currently widely used include porous materials such as polyvinyl chloride, polypropylene, glass fiber, polyethylene, and polyvinyl alcohol as reinforcing materials, such as woven fabrics, nonwoven fabrics, knitted fabrics, and porous materials. membranes, etc. are used. In addition, as an oxidation-resistant intestinal ion exchange membrane that has attracted attention in recent years, an ion exchange resin in which ion exchange groups and fluorine atoms are statistically uniformly bonded has been developed. The ion exchange membrane molded from this fluorine-containing resin uses tetrafluoroethylene woven fabric as a reinforcing material, but the adhesion to the ion exchange resin component is insufficient.
It has a defect in which the resin component easily peels off from the reinforcing material (cloth). Therefore, reinforcing materials in ion-exchange membranes are used to provide strength and dimensional stability to the membrane and to make the membrane easier to handle, but at the same time, they suppress swelling of the ion-exchange membrane, that is, suppress an increase in water content. It is also expected to play a role similar to that of a crosslinking agent, such as increasing the concentration of fixed ions.

However, if the ion exchange in the ion exchange membrane is not sufficient and the adhesion between the resin component and the reinforcing material is not sufficient, that is, if the reinforcing material and the ion exchange resin component are not tightly integrated,
The above-mentioned effects of the reinforcing material are completely lost. From this point of view, the inventors of the present invention have conducted extensive research, and have surprisingly succeeded in reinforcing the fluorine-containing cation exchange resin membrane. When the material contains the following structural unit having a polar group such as a sulfonic acid group, a carboxyl group, or a phosphoric acid group as one component, the adhesion between the reinforcing material and the fluorine-containing ion exchange resin component is extremely good. This discovery led to the completion of the present invention.

That is, the present invention provides an ion exchange resin in which an intestinal ion exchange group and a fluorine atom are uniformly bonded, and a porous fluorine-containing resin having at least one of the structural units shown in the following formulas (1) and (0). This is an intestinal ion exchange resin membrane that is tightly integrated with a reinforcing material of organic matter. However, Rf is a linear or branched perfluoroalkylene group or perfluoroalkylene ether group; A is an intestinal ion exchange group or (and) a derivative thereof, such as -SQX, -COX, -PX2
, (X is 10 days, 10R, 0M, 1N ratio, NHR, 1NR, R2 and halogen, R, R
, , R2 is an alkyl or halogenated alkyl group, M is a metal ion), or a salt thereof, a sulfonic acid halide group, an acid halide group, a phosphorus halide group, or an acid ester group.

The form of the reinforcing material used in the present invention is a porous organic material in the form of a porous sheet; nonwoven fabrics, woven fabrics, knitted fabrics, etc. made of monofilament and multifilament fibers are common, and multifilament is preferable. It is a plain woven fabric.

When the porosity of these porous reinforcing materials is small, the effect of suppressing the swelling of the ion exchange membrane resin component is significant, but the electrical resistance of the membrane increases significantly.On the other hand, when the porosity is too large, the swelling of the ion exchange membrane resin component is significantly increased. It is difficult to define the porosity unconditionally because the effect of suppressing fly-over is weak, and it varies depending on the size of multifilament, monofilament, and yarn in the case of woven and knitted fabrics, but in general, the porosity is 10 to 10.
95%, preferably 20-80%. The porosity here refers to the volume of reinforcing material per unit area obtained by soaking a unit area of reinforcing material in a solvent that sufficiently wets the reinforcing material, and calculating the volume of reinforcing material per unit area.
Calculate the volume of the rectangular parallelepiped from the thickness and area of the reinforcement. It is expressed as a percentage of the value obtained by subtracting the volume occupied by the reinforcing material previously determined from the volume of this rectangular parallelepiped and dividing it by the volume of the rectangular parallelepiped. The porous membrane should preferably have as high a porosity as possible, have small pores, and have a well-distributed pore distribution. In addition, in the case of woven or knitted fabrics, if the openings are too large, the ion-exchange resin component in the present invention will not be effective in suppressing swelling, and if it is too delicate, the electrical resistance of the membrane will rise sharply. Become. Furthermore, in consideration of the durability of the ion-exchange membrane, it is preferable to use a polymeric compound containing at least one component of a fluorine-containing polymer compound, especially tetrafluoroethylene, as a reinforcing material. Due to their low surface energy, polymeric compounds cannot sufficiently function as reinforcing materials.

However, the present invention allows the presence of a structural unit having a polar group as at least one of the structural units shown in the above formulas (1) and (0) in the reinforcing material, thereby significantly reducing the ion exchange resin component and the reinforcing material. This results in a cationic exchange resin film that has improved adhesion with the reinforcing material and the resin component. As a method for causing the presence of at least one of the structural units shown in the above formula (1) and formula (0) having an essential polar group in the reinforcing material of the present invention, (i
) Futsuhata vinyl monomer, tetrafluoroethylene,
Hexafluoropropylene, trifluoroethylene chloride,
At least one of ethylene trifluoride, vinylidene fluoride, and the like is copolymerized with a monomer capable of forming at least one of the structural unit formulas (1) and (0).

This is then made into a porous reinforcing material. (ii) Formula (1) is applied to a porous reinforcing base material made of at least one of tetrafluoroethylene, hexafluoropropylene, trifluoroethylene chloride, trifluoroethylene, vinylidene fluoride, etc.
and a monomer capable of forming at least one form of the structural unit shown in formula (b) is graft-polymerized.

(iiD tetrafluoroethylene, hexafluoropropylene, trifluoroethylene chloride, trifluoroethylene,
At least one of formula (1) and formula (0) with other fluorine-containing polymeric compounds that do not have the constituent units of formula (1) and (or) formula (0), such as vinyl fluoride, etc. A porous reinforcing material made of a homogeneous mixture with a polymer compound composed only of structural units.

The most preferred method is copolymerization (l).

Of course, in addition to the above, hydrocarbon-based vinyl mo/mers such as ethylene, propylene, butene, acrylic acid, methacrylic acid, styrene, pinyl chloride, vinylidene chloride, vinylpyridine, etc. can be used as a copolymer, graft, or blend. Although some parts may be present, it is unavoidable that the chemical resistance deteriorates due to this. The graft polymerization method, which is one embodiment of the method described above (regarding i, in which a fluorine-containing vinyl monomer having carboxylic acid, sulfonic acid or (and) derivatives thereof, etc.) is present in the reinforcing material, A common method is to use ionizing radiation such as Q-rays, B-rays, Y-rays, or electron beams, X-rays, ultraviolet rays, etc. to form radicals on the reinforcing material and graft them. For example, active sites may be formed by treatment with alkali metal-naphthalene, alkali metal amide, alkali metal amalgam, etc., such as sodium naphthalene, sodium amide, and sodium amalgam.

Alternatively, it may be heated together with aluminum halide, phosphorus pentachloride, phosphorus trichloride, etc., or further with a radical initiator. In any case, methods of forming active sites radically, thermally, or ionically may be used without any restriction. Grafting to this active site is not limited to this in any way. Regarding the method, a method in which at least one of the structural units of the structural unit formula (1) and the formula (b) is present during copolymerization by copolymerization with another fluorine-containing monomer is known as a thermal A polymer formed by an ionic or radical polymerization reaction may be spun or woven into a woven fabric by a method capable of producing molten paper yarn, emulsion-grade yarn, or other fibers.

Furthermore, in the case of the method of blending a polymer of a compound of the structural unit of at least one of formula (1) and formula (b) with another fluorine-containing polymer and spinning it, conventional polymer compounds can be used. Blends, paper yarns, and textile methods may be used without any restriction. In the reinforcing material of the present invention, formula (1) and formula (
The polar group bonded to at least one of the structural units of 0) gradually changes to an acid type or a salt type and becomes hydrated when the produced ion exchange membrane is used.

If there are many such polar groups in the base material, the porous reinforcing material itself will expand and contract significantly and no longer fulfill its role as a reinforcing material.
Since the reinforcing material itself acts as an ion exchange membrane, it is not preferable to introduce a large amount of polar groups. However, if the amount of suitable groups is too small, the effect of tightly integrating the reinforcing material and the ion exchange resin component may be lacking. Therefore, as a result of various measurements, when a monomer having a polar group introduced into a reinforcing material is hydrolyzed or otherwise treated to form a cation exchangeable group, the exchange capacity per unit weight of the reinforcing material is 0. It has been found that a reinforcing material which can be used as an industrially very useful ion exchange membrane can be obtained when the dry reinforcing material is in the range of 0.001 to 0.5 meq/g dry reinforcing material. In this case, the weight of the reinforcing material is the weight when it is dried under reduced pressure at room temperature after undergoing hydrolysis and other treatments, and the exchange capacity is 6000 ml of reinforcing material that has also been subjected to hydrolysis and other treatments. After that, the sample was thoroughly washed with water to remove excess adsorbed HCI, and then immersed in 4.0N NaCI for ion exchange, and the resulting hydrogen ions were determined by titration using methyl orange as an indicator. All conventionally known methods can be used to make the ion exchange resin membrane of the present invention using the above-mentioned reinforcing material. That is, a method of polymerizing or condensing a polymerizable or condensable monomer mixed with an appropriate crosslinking agent if necessary on the reinforcing material; The above-mentioned reinforcement may be carried out by mixing a fine powder, granular, or film-like polymer compound with a functional group that can easily convert an exchange group or an ion exchange group with other inert polymer compounds as necessary. A method of attaching an inert polymer compound to the reinforcing material using heat, pressure, etc. in the form of a film, which has an ion exchange group or a functional group that can be easily converted into an ion exchange group. Craft polymerization or impregnation polymerization; methods of condensing the compound are some examples. In addition, cation exchange groups include sulfonic acid, carboxylic acid,
Phosphoric acid, phosphorous acid, phosphoric acid ester, sulfuric acid ester, phenolic hydroxyl group, thiol group, etc., which can be negatively charged in an aqueous solution or a water-organic solvent system, are used. Of course, not only cation exchange groups but also anion exchange groups may coexist in the resulting ion exchange membrane. That is, any one of an amphoteric ion exchange membrane, a composite ion exchange membrane, and a mosaic ion exchange membrane may be used. However, particularly preferred for carrying out the method of the present invention are fluorine-containing cation exchange resin membranes, particularly tetrafluoroethylene and perfluoro(3,6-dioxer-4-methyl-7-octensulfonyl fluoride) or (and) Perfluoro (
The most preferred is an ionic resin membrane produced using a polymer membrane obtained from a polymer of alkyl vinyl ether carboxylic acid, salt, or ester.

The cation exchange resin membrane of the present invention, especially the perfluorosulfonic acid type and perfluorocarboxylic acid type cation exchange resin membrane, has significantly increased mechanical strength, is easy to handle, and at the same time, swelling of the membrane is suppressed. As a result, the fixed ion concentration becomes high, and when this intestinal ion exchanger resin membrane is used as a barrier for obtaining alkali metal hydroxide by electrolysis of alkali metal salts, the current efficiency for obtaining alkali metal hydroxide increases. At the same time, the amount of alkali metal salt in the alkali metal hydroxide is reduced and the purity is improved. Furthermore, since the reinforcing material is imparted with some ionic conductivity, the electrical resistance of the membrane is reduced, and other effects are produced. In order to further enhance the current effect of the intestinal ion exchange membrane, Japanese Patent Publication No. 47-3801, 47-38
02, U.S. Patent No. 3647086, U.S. Patent No. 3969285
As shown by the method described in the specification, the acid halide group on the side facing the cathode side of the acid halide membrane is reacted with a compound having at least one primary and/or secondary amino group. Even higher current efficiency can be expected if the remaining acid halide groups are hydrolyzed after applying heat treatment or other means if necessary. The amino compounds used in this case include monoalkylamines such as methylamine, ethylamine, and laurylamine; dialkylamines such as dimethylamine, diethylamine, and dilaurylamine;
Diamines such as ethylenediamine, hexamethylenediamine, piperazine, N,N'-dimethylethylenediamine, and phenylenediamines, polyethylene polyamines such as jethylenetriamine, triethylenetetramine, and tetraethylenebentamine, polyallylamine, polyvinylamine, etc. These polyamines are preferably used. It is also effective to react with other substances that can bond with acid halide groups to reduce the degree of dissociation of the ion exchange group and preferably form a crosslinked structure. Specifically, aromatic compounds, amino alcohols, Alcohols and the like are preferably used. When these are reacted on one side of an acid halide type membrane, all of the acid halide groups may be bonded, or only a portion may be reacted and the remainder becomes an enteric ion exchange group by hydrolysis and becomes an amino group. and cation exchange groups may coexist, and when a primary amine reacts with an acid halide group, it may form a weakly acidic enteric ion exchange group of an acid amide group. Such a treatment layer may be formed by reacting a single polymeric film having acid halide groups from one side, or by performing the above reaction on a thin film having sulfonyl halide groups and then removing unreacted It may also be fused to a polymer membrane. Although the present invention has been briefly described above, the ion exchange membrane of the present invention can be applied to any field using any conventionally known ion exchange membrane.

Namely, diffusion dialysis, electrodialysis, electrode reaction diaphragm, reverse osmosis,
Ion exchange membranes for ultrafiltration membranes, other Donnan dialysis,
The ion exchange membrane of the present invention can be used as a diaphragm for fuel cells, etc., and the function of the ion exchange membrane of the present invention can be further enhanced especially when used as a cation exchange membrane for salt electrolysis. The content of the present invention will be specifically explained in the following examples, but the content of the present invention is not limited to the following examples.

Example 1 Exchange capacity when hydrolyzed with a copolymer of tetrafluoroethylene and perfluoro(3,6-dioxa-4-methyl-7-octensulfonyl fluoride) is 0.8
A 2 mm thick sheet of 3 meq/g dry membrane (Japanese type) was used as the ion exchanger raw material.

As the reinforcing material, a plain woven fabric having a thickness of 0.25 ribs was used, in which 45 threads/fnch of 400 denier polytetrafluoroethylene were inserted both vertically and horizontally.

To this, 500 ad of y-rays were applied from a Co6o source in a vacuum.
After irradiating with 7 Mrad at a ratio of was taken out from the vacuum and hydrolyzed by a conventional method, and the exchange capacity was measured, and it was found to be 0.28.
milliequivalents/gram dry cloth. This was then sandwiched between two 2 mil sulfonyl fluoride type sheets and fused by heating and pressurizing to form a sheet having a modified polytetrafluoroethylene plain woven fabric as a reinforcing material. Two sulfonyl fluoride type sheets were obtained.

This was hydrolyzed with a 10% methanol solution of NaOH in a conventional manner to obtain an intestinal ion exchange membrane. The electrical resistance of this film is 25.0oo, 0. The electrical resistance in state-NaCI was 4.10-m. Using this cation exchange membrane, saturated saline was electrolyzed in an electrolytic cell with an effective current carrying area of 1 d.

A titanium wire mesh coated with Ti02/Ru02 was used as the anode, and a soft iron wire mesh was used as the cathode.
When saturated saline was also supplied to the anode chamber and electrolysis was carried out at a current density of 3 ships/d, 6. Obtain sail-NaOH and current efficiency 88
%, the amount of NaCI in NaOH is 35 legs (48% Na
(converted to OH). This was electrolyzed continuously for two months, but 6. The current efficiency obtained for NaOH was 87%. On the other hand, the same plain woven fabric made of polytetrafluoroethylene as above was used, but perfluoro(3,6-dioxer 4-methyl-7-octensulfonyl fluoride) was used.
A non-grafted material was used as a reinforcing material and bonded to two 2 mil sulfonyl fluoride type sheets under heat and pressure in the same manner as above.

The electrical resistance of the cation exchange membrane obtained by hydrolysis was 4.
．． When saturated saline solution was electrolyzed under the same conditions at the 50-th point, 6.0N-NaOH was obtained, the current efficiency was 85%, and N
The amount of NaCI in aOH was 150 (48% conversion). Two months later, 6.0N-NaOH was obtained and the current efficiency was 67%.

Separately, a plain woven fabric made of the same polytetrafluoroethylene was immersed in an etching solution of sodium naphthalene-tetrahydrofuran as a reinforcing material instead of being irradiated with the above-mentioned Y-ray, and the same perfluorinated sulfonyl fluoride type was used. The resin was fused and hydrolyzed to produce a cation exchange membrane in the same manner. When electrolysis of saline water was carried out in the same manner using this intestinal ion exchange membrane, 6. Side-NaOH was obtained with a current efficiency of 87%, and the amount of NaCI in NaOH was 60 legs (
(48% NaOH equivalent), but two months later the current efficiency was 69%. The electrical resistance of this film is 4
．． It was my 30th. Example 2 Tetrafluor.

Ethylene and perfluoro(3,6-dioxer-4-methyl-7-octensulfonyl fluoride) were copolymerized with different compositions. That is, emulsion polymerization was carried out using two parts of tetrafluoroethylene and one part of perfluoro(3,6-dioxer-4-methyl-7-octensulfonyl fluoride). To this emulsion was added a paper thread liquid of viscose slation to form a twill thread using a conventional method. After forming into a sintered thread, it was made into a 400 denier thread. This was immersed in dimethyl sulfoxide, water, and caustic soda for hydrolysis treatment, and the exchange capacity was measured to be 0.4 meq/g dry cloth (Japanese type). This 400 denier thread was used both vertically and horizontally to make a plain woven fabric with 45 threads. When this cloth was hydrolyzed with a copolymer of tetrafluoroethylene and perfluoro(3.6-dioxa-4-methyl-7-octensulfonyl fluoride), the exchange capacity was 0.91 meq/g dry membrane. 2
It was sandwiched between sheets of a mill and fused by heating and pressure to form a single polymer membrane. Furthermore, a 1 mil sheet of sulfonyl fluoride type having an exchange capacity of 0.6 meq/g dry membrane when hydrolyzed was fused to this to form a single polymer membrane. This was immersed in a 10% caustic soda methanol solution at 6020 for 1 hour to hydrolyze the sulfonyl fluoride groups on the membrane surface and inside the membrane to obtain the cation exchange membrane of the present invention. 0 of this membrane. The electrical resistance measured by 1000 cycles of AC at 25,000 in NaCI was 4.70. On the other hand, as a reinforcing material, a plain woven fabric made of polytetrafluoroethylene with the same 400 denier strands (45 in both length and width) was used, and tetrafluoroethylene and perfluoroethylene were used in the same manner. (Exchange capacity 0.91 which is a copolymer of 3.6-dioxer 4-methyl-7-octensulfonyl fluoride
Two 2 mil milliequivalent/gram dry membranes (Nippon Type) and one 1 mil exchange capacity 0.67 milliJ equivalent/gram dry membrane (Nippon Type) were used. A polymer membrane was prepared and further hydrolyzed to obtain a cation exchange membrane.The resistance value of this membrane at 0.0% - NaCI, 25.0oo was 5.
．． It was a 20-c tiger. Next, using these two obtained cation exchange membranes, electrolysis of saline solution was carried out in the same manner as in Example 1.

As a result, 6.0N-NaOH was obtained, and in the case of the intestinal ion exchange membrane made using the reinforcing material obtained from the copolymer of the present invention, the current efficiency was 90% and 88% after 2 months. The amount of NaCI in NaOH was 2 duns (48% NaOH equivalent). On the other hand, the current efficiency of a membrane made of a reinforcing material made of polytetrafluoroethylene was 88% at first, and decreased to 80% after two months. Also, NaC in NaOH
The amount of I was 120 skin (48% NaOH equivalent). Example 3 Exchange capacity when hydrolyzed with a copolymer of tetrafluoroethylene and barfluoro(3,6-dioxer-4-methyl-7-octensulfonyl fluoride) is 0.8
Four types of reinforcing materials treated as follows are sandwiched between two sheets of 2 mil thickness equivalent to 3 milliequivalent/g dry membrane (Nippon Type) and heated and fused under pressure to form a single high-profile sheet. It was made into a molecular film.

A copolymer of 56 mol % of ethylene tetrafluoride, 43 % of ethylene, and 1 mol % of hexafluorinated propylene was melt-spun to obtain a thread of about 65 microns. This was woven into a silk-like form (70 strands per inch for both length and width), immersed in the resulting monomer, and y-rays were irradiated from a Co6O source at 300 rad/hr for 0.09 Mrad each. Irradiation was carried out in a nitrogen atmosphere of 2 Mrad, base ad, and wind Mrad.

When the net-like material was taken out and the exchange capacity after hydrolysis treatment was measured using a conventional method, the results were 0.0005, 0.08, and 0.2, respectively.
It was 1.0.62 milliequivalents/gram dry cloth (Japan type). In addition to this polymeric membrane material containing reinforcing material, another sheet of
．． The same Tetrafluor in 0 mil.

The exchange capacity when hydrolyzed with a copolymer of ethylene and perfluoro(3.6-dioxa-4-methyl-7-octensulfonyl fluoride) is equivalent to 0.91 milliequivalent nogram dry membrane (Japan type) After soaking the sheet in ethylenediamine at 80°C for 3 hours, this was heated and fused under pressure onto the previously obtained polymer membrane containing the reinforcing material to form a single polymer sheet. It was made into a film-like material. This was soaked in dimethyl sulfoxide, water, and the hydrolyzate of NaOH in a conventional manner to convert the sulfonyl fluoride group into sodium sulfonate. The cation exchange membrane obtained above was subjected to electrolysis of saturated saline in the same manner as in Example 1.

In addition, a sheet of the above-mentioned copolymer was heated and fused under pressure without grafting to the reinforcing material (exchange capacity 0) to form an intestinal ion exchange membrane, which was also subjected to electricity treatment with saturated saline. It was subjected to decomposition.

The electrical resistance of the membrane is 100 AC in 6.0N-NaOH.
Measured at a specific ycle of 25,000. The results are shown in Table 1. The elongation of the first surface membrane is measured by dividing the elongated length when the dry membrane is immersed in pure water by the length of the dry membrane.

Example 4 CF2=CF2 and CF2=CF-.

A copolymer of 1(CF2)3C〇〇CH3 with an exchange capacity of 1
．． A polytetrafluoroethylene cloth treated as follows is sandwiched between two 2 mil sheets of 26 milliequivalent/g dry membrane (Nippon Type) and heated and pressure fused to form a single sheet. It was made into a polymer membrane. Polytetrafluoroethylene cloth is 1
It was a plain weave fabric made of 70 00 denier multifilament cloth, which was stitched both vertically and horizontally.

This is then heated at 800 ad/hr from a Co6o bran source in a vacuum.
After irradiating y-rays of 8 Mrad at a dose rate of CF2=
Graft polymerization was carried out by immersing it in CF-◯-(CF2)3COOCH3. The exchange capacity when hydrolyzed was 0.20 meq/g dry cloth (Japanese type).
On the other hand, a cloth that had not been subjected to grafting treatment was similarly sandwiched between two 2 mil sheets and fused together under heat and pressure. The properties of the membrane containing these two types of reinforcing materials and the electrolytic performance during salt electrolysis were measured.

The results are shown in Table 2. Table 2 Example 5 Polytetrafluoroethylene was threaded using a fused wire thread to obtain a 3 denier monofilament, which was bundled into 10 filaments and spun to obtain a 30 denier thread.

This was subjected to tangle-drawing with 30 strands each in both vertical and horizontal directions to obtain a cloth made of polytetrafluoroethylene. This was irradiated with y-rays from a Co60 source in a vacuum for 7 Mmd at a rate of 500 ad/hr, and then immersed in the following vinyl monomer solution at 60 pm for 2 years to form a vinyl monomer. The grass was graft-polymerized onto a woven fabric made of polytetrafluoroethylene. 1 Bar fluoroacrylic acid fluoride (manufactured by PCR, USA) only.

2 2:1 (volume ratio) ratio of perfluoroacrylic acid fluoride and perfluoro(3.6-dioxer-4-methyl-7-octensulfonyl fluoride).

Next, the woven fabric soaked in each case was immediately soaked in methanol and heated to 60° C. for 1 hour to convert the carboxylic acid fluoride groups to carboxylic acid ester groups.

Next, intestinal ion exchange membranes were made using these two types of woven fabrics.

That is, it is a copolymer of tetrafluoroethylene and perfluoro(3,6-dioxa-4-methyl-7-octensulfonyl fluoride) with a thickness of 4 mils and an exchange capacity of 0.
．． The above woven fabric was heated and pressed into a film having sulfonyl fluoride groups equivalent to 91 meq/g dry membrane. Next, on top of this membrane with the reinforcing material, a thickness of 1.5 with an exchange capacity of 0.67 meq/g dry membrane equivalent is applied.
A film having Mill's sulfonyl fluoride groups was fused to form a single membrane. On the other hand, for comparison, the same woven fabric made of polytetrafluoroethylene but not subjected to graft polymerization treatment was also used to prepare a membrane-like product. The above three types of membrane-like materials were hydrolyzed in a conventional manner with a mixed solution of dimethyl sulfoxide, caustic potassium, and water to introduce cation exchange groups.

Next, the membrane was immersed in saline to form the Na type, and then electrolysis of saturated saline was carried out in the same manner as in Example 1.

These results are shown in Table 3. In Table 3, the exchange capacity is the exchange capacity of the grafted polytetrafluoroethylene. That is, only the grafted polytetrafluoroethylene sweat reinforcing material is immersed in a 10% caustic soda methanol solution and refluxed to hydrolyze the carboxylic acid methyl ester and partially generated sulfonic acid methyl ester. The exchange depth capacity was determined by determining a constant curve. Table 3

Claims (1)

[Scope of Claims] 1. A fluorine-containing porous material having an ion exchange resin in which a cation exchange group and a fluorine atom are uniformly bonded, and at least one of the structural units represented by the following formulas (I) and (II). A cation exchange resin membrane formed by tightly integrating an organic reinforcing material ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (However, Rf is a linear or branched perfluoroalkylene group or perfluoroalkylene ether group;
A is a cation exchange group or (and) a derivative thereof. )2 The cation exchange resin membrane according to claim 1, wherein the ion exchange resin is perfluoro-based. 3. The cation exchange resin membrane according to claim 1, wherein the ion exchange resin has a cation exchange group at the end of a side chain pendant to a perfluorocarbon main chain via an ether bond. 4 The reinforcing material of the fluorine-containing porous organic material has the structural unit formula (I
) and formula (II) and another fluorine-based vinyl monomer. 5. A patent claim in which the reinforcing material of the fluorine-containing porous organic material is a graft polymer having at least one constituent unit of formula (I) or formula (II) as a graft portion to a backbone polymer made of a fluorine polymer. The cation exchange resin membrane according to item 1. 6 A patent in which the reinforcing material of a fluorine-containing porous organic material is a homogeneous mixture of a polymer compound composed of at least one of formula (I) and formula (II) and another fluorine-containing polymer compound. A cation exchange resin membrane according to claim 1. 7. Claim 4, 5, or 6, wherein the other fluorine-based vinyl monomer is at least one selected from tetrafluoroethylene, hexafluoropropylene, trifluoroethylene chloride, and vinylidene fluoride. cation exchange resin membrane. 8 Replacement capacity per unit weight of reinforcing material is 0.01 to 0.
．． A cation exchange resin membrane according to claim 1, which is a 5 meq/g dry reinforcement. 9 Claim 1, wherein the cation exchange group is at least one of a sulfonic acid group and a carboxyl group.
The cation exchange resin membrane described in Section 1.