JP4670073B2 - Method for producing nano space control polymer ion exchange membrane - Google Patents

Description

The present invention relates to a method for producing a polymer ion exchange membrane which is a solid polymer electrolyte membrane suitable for use in a fuel cell.
The present invention also relates to a method for producing a polymer ion exchange membrane which is a solid polymer electrolyte membrane suitable for a fuel cell and has excellent electrical conductivity as well as excellent oxidation resistance, heat resistance and dimensional stability.

  A fuel cell using a solid polymer electrolyte type ion exchange membrane is expected to be used as a power source for electric vehicles and a simple auxiliary power source because of its high energy density. In this fuel cell, the development of a polymer ion exchange membrane having excellent characteristics is one of the most important technologies.

  In a polymer ion exchange membrane fuel cell, the ion exchange membrane acts as an electrolyte for conducting protons, and also prevents direct mixing of hydrogen or methanol as a fuel with air (oxygen) as an oxidant. It also has a role as a diaphragm. As such an ion exchange membrane, the ion exchange capacity is large as an electrolyte, and since a current is passed for a long period of time, the membrane is chemically stable, particularly resistant to hydroxyl radicals and the like which are the main causes of membrane degradation (oxidation resistance) It is required that the film has excellent heat resistance at 80 ° C. or higher, which is the operating temperature of the battery, and that the water retention of the film is constant and high in order to keep the electric resistance low. On the other hand, due to the role as a diaphragm, it is required that the film has excellent mechanical strength and dimensional stability and does not have excessive permeability to hydrogen gas, methanol or oxygen gas.

  Early polymer ion exchange membrane fuel cells used hydrocarbon polymer ion exchange membranes produced by copolymerization of styrene and divinylbenzene. However, this ion exchange membrane has poor durability due to oxidation resistance, so it is not practical. After that, a perfluorosulfonic acid membrane “Nafion (registered trademark of DuPont)” developed by DuPont is available. It has been used in general.

  However, conventional fluorine-containing polymer ion exchange membranes such as “Nafion (registered trademark)” are excellent in chemical durability and stability, but have a small ion exchange capacity of around 1 meq / g, Insufficient water retention causes drying of the ion exchange membrane, resulting in a decrease in proton conductivity, and when methanol is used as fuel, membrane swelling and methanol crossover may occur.

  In order to increase the ion exchange capacity, if a large number of sulfonic acid groups are to be introduced, the polymer chain does not have a cross-linked structure, so that the membrane swells and the strength is remarkably lowered and easily broken. Therefore, in the conventional fluorine-containing polymer ion exchange membrane, it is necessary to suppress the amount of sulfonic acid groups to such an extent that the membrane strength is maintained, so that the ion exchange capacity is only about 1 meq / g.

  Furthermore, fluorine-containing polymer ion exchange membranes such as Nafion (registered trademark) are difficult and complicated to synthesize monomers, and the process of polymerizing them to produce polymer membranes is also complicated, so the product is very The proton exchange membrane fuel cell is a major obstacle when it is put into practical use by mounting it in an automobile or the like. Therefore, efforts have been made to develop a low-cost and high-performance electrolyte membrane that replaces the Nafion (registered trademark) and the like.

  On the other hand, in the radiation graft polymerization method closely related to the present invention, an attempt is made to produce a solid polymer electrolyte membrane by grafting a monomer capable of introducing a sulfonic acid group into the polymer membrane. The present inventors have repeatedly studied to develop these new solid polymer electrolyte membranes, and introduced ion exchange by introducing a styrene monomer into a polytetrafluoroethylene film having a crosslinked structure by a radiation graft reaction and then sulfonating. An application has been filed for a solid polymer electrolyte membrane and a method for producing the same, characterized in that the capacity can be controlled in a wide range (Patent Document 1). However, in this ion exchange membrane, since the styrene graft chain is composed of hydrocarbons, when a current is passed through the membrane for a long time, oxidation occurs in a part of the graft chain portion, and the ion exchange ability of the membrane is lowered.

Furthermore, the present inventors introduced a sulfone group into the graft chain following radiation grafting or radiation co-grafting of a fluorine-based monomer to a polytetrafluoroethylene film having a crosslinked structure, thereby providing a wide ion exchange capacity and excellent An application for a solid polymer electrolyte membrane characterized by oxidation resistance and a method for producing the same was filed (Patent Document 2). However, in a normal fluorine polymer film, the grafting reaction of the fluorine-based monomer hardly proceeds to the inside of the film, and depending on the reaction conditions, the graft reaction is limited to the film surface, so it is difficult to improve the characteristics as an electrolyte film. It has been found.
JP 2001-348439 A JP 2002-348389 A

  The present invention has been made in order to overcome the above-mentioned problems of the prior art. As a polymer solid electrolyte, the ion exchange capacity is small and the dimensional stability of the membrane is a drawback of the polymer ion exchange membrane. The problem to be solved is poor performance, low oxidation resistance, and low operating temperature, that is, low heat resistance.

  The present invention provides a polymer ion exchange membrane having a wide ion exchange capacity and excellent oxidation resistance and electrical conductivity and a method for producing the same, and particularly suitable for use in fuel cells and A manufacturing method thereof is provided.

  As a result of research on irradiation of polymer films, grafting or co-grafting of various monomers, and introducing sulfonic acid groups into the resulting graft chains, polymer films were used as substrates. Irradiated with high-energy heavy ions to form a large number of fine cylindrical through-holes with a nano to micron diameter, and a specific functional monomer is grafted into the holes by ionizing radiation, and the graft is formed into a membrane. The present inventors have invented a method for producing a polymer ion exchange membrane characterized in that the polymer is allowed to proceed to the center, and then the introduced functional group such as a sulfonyl group, ester group or halogen group is a sulfonic acid group. The polymer ion exchange membrane of the present invention is characterized in that the graft ratio of the monomer to the polymer film is 10 to 150% and the ion exchange capacity is 0.3 to 2.5 meq / g. In addition, the polymer ion exchange membrane of the present invention can appropriately control each characteristic such as ion exchange capacity within a wide range, has high oxidation resistance, heat resistance and electrical conductivity, and has dimensional stability of the membrane. It has extremely excellent characteristics such as high.

  The polymer ion exchange membrane produced by the present invention has the characteristics that the ion exchange capacity can be controlled in a wide range together with excellent oxidation resistance, electrical conductivity, dimensional stability, and methanol resistance.

  The ion exchange membrane of the present invention having the above characteristics is particularly suitable for use in a fuel cell membrane. Moreover, it is useful as an inexpensive and durable electrolytic membrane or ion exchange membrane.

  In one embodiment of the present invention, polyvinylidene fluoride (hereinafter abbreviated as PVDF) having high heat resistance and oxidation resistance is used as the polymer film substrate. The polymer film substrate may have a crosslinked structure, and the crosslinked structure in the polymer structure improves the heat resistance of the film and the graft ratio of the monomer, and further suppresses the decrease in film strength due to irradiation. be able to. A polymer film substrate having a crosslinked structure is suitable for high-performance fuel cell membranes operating at high temperatures.

  The film substrate is irradiated with high energy heavy ions by a cyclotron accelerator or the like. The heavy ion in the present invention refers to an ion that is higher than the carbon ion. With ions having a smaller mass than carbon ions, in the perforation after ion irradiation, the ratio of the hole depth to the hole diameter is small, and it is difficult to produce a deep hole with a small diameter in the polymer film substrate. Various ions can be used as heavy ions, but in order to form minute through-holes of nano to micron size in a polymer film, the irradiation damage region by one ion spreads from several nanos to several hundreds nanos (H. Kudoh and Y. Morita, J. Poly. Sci., Part B. Vol. 39, 757 (2001)). The size of the irradiation damage region depends on the mass and energy of the irradiated ions. As types of heavy ions used for irradiation, carbon, nitrogen, oxygen, neon, argon, krypton, xenon, and the like are easy to generate ions and are useful as irradiation ion species.

  In order to enlarge the irradiation damage area of one ion, ions having a large mass such as gold ions, bismuth ions, or uranium ions are used. The ion irradiation energy may be energy that can penetrate the polymer film substrate in the thickness direction. For example, when the polyvinylidene fluoride film substrate is 50 μm thick, the carbon ion is 40 MeV or more, and the neon ion is 80 MeV or more. In the case of argon ions, it is 180 MeV or more. Similarly, at a thickness of 100 μm, carbon ions are 62 MeV or more, neon ions are 130 MeV or more, and argon ions are 300 MeV or more. Further, it penetrates a polymer film substrate having a thickness of 40 μm for xenon ion 450 MeV and 20 μm for uranium ion 2.6 GeV.

  Next, the ion-irradiated film was subjected to 0.1N to 10N KOH or NaOH solution (water, or a mixed solution of alcohol and water such as methanol, ethanol, n- or isopropanol, or t-butanol) at room temperature to 80 ° C. By processing, a fine cylindrical through-hole is formed around the ion irradiation damaged region (Japanese Patent Laid-Open Nos. 5-51479 and 6-7656).

In addition, in a fluorine-based film substrate, the irradiation damage portion is decomposed by heating at a temperature of 100 ° C. or higher and decomposes into a monomer or a monomer-like gas. The average diameter of the holes on the surface of the film substrate can be easily measured with a scanning electron microscope. The average diameter of the pores of the film substrate used in the present invention is preferably 10 nm or more and 10 μm or less on the film surface, but is more preferably 10 nm or more and 1 μm or less for an ion exchange membrane. If the hole is smaller than this, it is difficult to produce a through hole by etching, and if the hole is larger than this, the strength of the film substrate is lowered. Similarly, the number of holes on the substrate surface is proportional to the ion irradiation amount, and the number of holes is preferably 10 ⁴ to 10 ¹⁴ / cm ² .

At 10 ⁴ / cm ² or less, even if an ion exchange membrane is produced by the following grafting or sulfonation reaction, sufficient electric conductivity of the membrane cannot be obtained, and at 10 ¹⁴ / cm ² or more, the pores overlap each other and become independent. This is not preferable because the number of pores is reduced and the film characteristics are deteriorated.

The polymer ion exchange membrane according to the present invention is added to a monomer solution described below or a mixed solution of a monomer and a comonomer to the perforated PVDF film substrate, and degassed under reduced pressure to obtain γ rays, high energy electron beams, By irradiating with ionizing radiation such as X-rays, an active site for grafting is generated on the surface of the film substrate or on the surface of the hole, and the monomer is simultaneously graft polymerized therewith, and further, a sulfonyl halide group in the graft molecular chain [ It is produced by converting —SO ₂ X ¹ ], a sulfonate group [—SO ₃ R ¹ ], or a halogen group [—X ² ] into a sulfonate group [—SO ₃ H]. Also, phenyl groups, ketones, ether groups, etc. present in hydrocarbon monomers are produced by introducing sulfonic acid groups with chlorosulfonic acid. Here, the simultaneous graft polymerization is a method of performing graft polymerization by irradiating with ionizing radiation in a state where a film substrate and a monomer coexist.

In the present invention, the monomers shown in the following (1) to (10) or the monomer / comonomer system can be used as the monomer to be graft-polymerized on the polymer film substrate (hereinafter referred to as the monomer after grafting). This means that a sulfonic acid group can be introduced into this monomer unit, and a comonomer means that a sulfonic acid group cannot be easily introduced into this comonomer unit after grafting.
(1) Group A: a monomer having a sulfonyl halide group, CF ₂ = CF (SO ₂ X ¹ ) (wherein X ¹ is a halogen group, -F or -Cl; the same shall apply hereinafter), CH _{2 ^{= CF (SO 2 X 1)}} , CF 2 = CF (O (CF 2) 1 ~ 4 SO 2 X 1), and _{CF 2 = CF (OCH 2 (} CF 2) 1 ~ 4 SO 2 X 1)
One or more monomers selected from the group consisting of
(2) Group B: CF ₂ = CF (SO ₃ R ¹ ), which is a monomer having a sulfonate ester (wherein R ¹ is an alkyl group, —CH ₃ , —C ₂ H ₅ or —C (CH ₃ ) _3. the same applies _{hereinafter.), CH 2 = CF (} SO 3 R 1), CF 2 = CF (O (CF 2) 1 ~ 4 SO 3 R 1), and _{CF 2 = CF (OCH 2 (} CF ₂ ) _One type or two or more types of monomers selected from the group consisting of ₁ to ₄ SO ₃ R ¹ ).
(3) C group:. During CF ₂ = CF having a halogenated fluoroalkyl ether group _{(O (CF 2) 1 ~} 4 X 2) ( wherein, X ² is -Br or -Cl halogen groups below The same), and CF ₂ = CF (OCH ₂ (CF ₂ ) ₁ to ₄ X ² ).
(4) The following groups A to C:
Group _{A: CF 2 = CF (SO 2} X 1) (.. Wherein, X ¹ is is -F or -Cl halogen group hereinafter the _{same), CH 2 = CF (SO} 2 X 1), CF 2 = _{CF (O (CF 2) 1} ~ 4 SO 2 X 1), and _{CF 2 = CF (OCH 2 (} CF 2) 1 ~ 4 SO 2 X 1);
Group B: CF ₂ = CF (SO ₃ R ¹ ) (wherein R ¹ is an alkyl group and is —CH ₃ , —C ₂ H ₅ , or —C (CH ₃ ) _{3. The} same shall apply hereinafter), CH. ^{_{2 = CF (SO 3 R 1}} ), CF 2 = CF (O (CF 2) 1 ~ 4 SO 3 R 1), and _{CF 2 = CF (OCH 2 (} CF 2) 1 ~ 4 SO 3 R 1); and group _{C; CF 2 = CF (O (} CF 2) 1 ~ 4 X 2) (.. wherein, X ² is -Br or -Cl halogen group hereinafter), and CF ₂ = CF (OCH ₂ (CF ₂ ) ₁ to ₄ X ² )
2 or more types of monomers selected from at least 2 or more different groups.

(5) A _{Group: CF 2 = CF (SO 2} X 1) (.. Wherein, X ¹ is is -F or -Cl halogen group hereinafter the _{same), CH 2 = CF (SO} 2 X 1), _{CF 2 = CF (O (CF} 2) 1 ~ 4 SO 2 X 1), and _{CF 2 = CF (OCH 2 (} CF 2) 1 ~ 4 SO 2 X 1) 1 kind selected from the group consisting or 2 As the acrylic comonomer, CF ₂ ═CR ² (COOR ³ ) (wherein R ² is —CH ₃ or —F, and R ³ is —H, —CH ₃ , —C ₂ H). ₅ or -C (CH _{3) 3).} same as below. And a monomer / comonomer system in which one or more comonomers selected from the group consisting of CH ₂ ═CR ² (COOR ³ ) are added in an amount of 50 mol% or less based on the total monomers.

(6) Group B: CF ₂ = CF (SO ₃ R ¹ ) (wherein R ¹ is an alkyl group, —CH ₃ , —C ₂ H _5, or —C (CH ₃ ) _{3. The} same shall apply hereinafter.) _{, CH 2 = CF (SO 3} R 1), CF 2 = CF (O (CF 2) 1 ~ 4 SO 3 R 1), and _{CF 2 = CF (OCH 2 (} CF 2) 1 ~ 4 SO 3 R 1 ), One or more monomers selected from the group consisting of CF ₂ ═CR ² (COOR ³ ) (wherein R ² is —CH ₃ or —F, R ³ Is —H, —CH ₃ , —C ₂ H ₅ or —C (CH ₃ ) ₃ ). same as below. And a monomer / comonomer system in which one or more comonomers selected from the group consisting of CH ₂ ═CR ² (COOR ³ ) are added in an amount of 50 mol% or less based on the total monomers.

(7) C _{group: CF 2 = CF (O (} CF 2) 1 ~ 4 X 2) (.. Wherein, X ² is -Br or -Cl halogen group hereinafter), and CF ₂ = CF To one or two monomers selected from the group consisting of (OCH ₂ (CF ₂ ) ₁ to ₄ X ² ), as an acrylic comonomer, CF ₂ = CR ² (COOR ³ ) (wherein R ² is a -CH ₃ or -F, R ³ is -H, -CH _3, a -C ₂ H ₅ or -C (CH _{3) 3).} same as below. And a monomer / comonomer system in which one or more comonomers selected from the group consisting of CH ₂ ═CR ² (COOR ³ ) are added in an amount of 50 mol% or less based on the total monomers.

  (8) Group D: One or more monomers selected from the group consisting of styrene, α-methylstyrene, styrene derivative monomers 2,4-dimethylstyrene, vinyltoluene, and 4-tert-butylstyrene. .

(9) Group E: acenaphthylene, indene, benzofuran, 5-vinyl-2-norbornene, vinyl ketone CH ₂ ═CH (COR ⁴ ) (wherein R ⁴ is —CH ₃ , —C ₂ H ₅ , or a phenyl group ( . -C ₆ H ₅₎ is a) vinyl ether ^{_{CH 2 = CH (OR 5)}} ( wherein, R ⁵ is _{-C n H 2n + 1 (n} = 1~5), - CH (CH 3) 2, -C (CH ₃ ) ₃ , or a phenyl group), and one or more selected from the group consisting of fluorovinyl ether CF ₂ ═CF (OR ⁵ ) or CH ₂ ═CF (OR ⁵ ) Monomer.

(10) The following D to F groups:
Group D: styrene, α-methylstyrene, styrene derivative monomers 2,4-dimethylstyrene, vinyltoluene, and 4-tert-butylstyrene; and Group E: acenaphthylene, indene, benzofuran, 5-vinyl-2-norbornene , Vinyl ketone CH ₂ ═CH (COR ⁴ ) (wherein R ⁴ is —CH ₃ , —C ₂ H ₅ , or a phenyl group (—C ₆ H ₅ )), vinyl ether CH ₂ ═CH (OR ⁵ (Wherein R ⁵ is —C _n H _{2n + 1} (n = 1 to 5), —CH (CH ₃ ) ₂ , —C (CH ₃ ) ₃ , or a phenyl group)), and fluoride. Vinyl ether CF ₂ ═CF (OR ⁵ ) or CH ₂ ═CF (OR ⁵ )
Group F: CF ₂ = CR ² (COOR ³ ) (wherein R ² is —CH ₃ or —F, and R ³ is —H, —CH ₃ , —C ₂ H ₅ or —C (CH ₃ )). _{3. The} same applies hereinafter.), And CH ₂ = CR ² (COOR ³ )
Two or more monomer / comonomer systems selected from each group of

Here, as the acrylic comonomer in the above (5) to (7) and (10), for example, CF ₂ = CF (COOCH ₃ ), CF ₂ = C (CH ₃ ) (COOCH ₃ ), CH ₂ = C (CH ₃ ) (COOH), CH ₂ = CF (COOCH ₃ ), CH ₂ = CF (COOC (CH ₃ ) ₃ ), and the like. Since these comonomers cannot easily introduce sulfonic acid groups into these comonomer units after grafting, they are preferably mixed in an amount of 50 mol% or less based on the total monomers.

In the single graft polymerization using the monomers (1) to (3), the graft polymerization proceeds sufficiently to the surface of the film substrate and the surface of the pores, and in the co-graft polymerization using the comonomers (4) to (7). The grafting speed is significantly increased as compared with single grafting. For _{example, CF 2 = CF (O (} CF 2) 1 ~ 4 SO 2 X 1), CF 2 = CF (O (CF 2) 1 ~ 4 SO 3 R 1), CF 2 = CF (O (CF 2) ₁ ~ ₄ X ²⁾ is less polymerizable alone as a monomer, but sufficiently useful when to comonomer co-grafted. When the monomers (8) to (10) are used, an effective amount of a sulfonic acid group can be introduced into the graft chain by a sulfonation reaction such as chlorosulfonic acid, as will be described later.

The monomers (1) to (10) and the monomer / comonomer system are Freon 112 (CCl ₂ FCCl ₂ F), Freon 113 (CCl ₂ FCClF ₂ ), dichloroethane, chloromethane, n-hexane, alcohol, and t-butanol. , Benzene, toluene, cyclohexane, cyclohexanone, or dimethyl sulfoxide may be used.

In addition, divinylbenzene and bis (vinylphenyl) group (CH ₂ ═CH (C ₆ H ₄ )) ₂ (CH ₂ ) _n (n = 1 to 4), trivinyl, One or more crosslinking agents selected from the group consisting of allyl cyanurate, triallyl isocyanurate, 3,5-bis (trifluorovinyl) phenol, and 3,5-bis (trifluorovinyloxy) phenol, Graft polymerization may be carried out by adding an amount of 30 mol% or less based on the monomer.

Furthermore, it is easy to become a base point of polymerization by irradiation in the graft monomer solution, and it is easy to keep crystal water and adsorbed water, which is an inorganic ultrafine particulate amorphous silica (SiO ₂ ), H ⁺ type mordenite (Ca, Na ₂ , K ₂ ) Al ₂ Si ₁₀ O ₂₄ · 7H ₂ O), Alumina (Al ₂ O ₃ ), Zirconium oxide (ZrO ₂ ), Inorganic proton conductor zirconium phosphate (Zr (HPO ₄ ) ₂ · nH ₂ O), phosphotungstic acid hydrate (H ₃ PW ₁₂ O ₄₀ · nH ₂ O), silicotungstic acid hydrate (H ₄ SiW ₁₂ O ₄₀ · nH ₂ O), and molybdophosphoric acid hydrate (MoO ₃ H ₃ PO ₄ .nH ₂ O) and their composites, phosphotungstic acid hydrate, zirconium phosphate, or silicotungstic acid hydrate adsorbed amorphous silica, and Phosphotungstic acid hydrate, zirconium phosphate, or silicotungstic acid hydrate The polymerization yield of the monomer is increased by adding one or more fine powders selected from the group consisting of the attached mordenite and alumina in the range of 1% by weight to 30% by weight based on the total monomer and graft polymerization. be able to. In addition, the conductivity of the produced graft polymer ion exchange membrane can be increased.

  There are different types of ultrafine amorphous silica (Aerosil ()) with different specific surface area, cohesiveness, and hydrophobicity. It can be easily dispersed uniformly in the monomer solution.

  In addition, as an example of how to make a composite, an amorphous silica fine powder adsorbed phosphotungstic acid hydrate can be obtained by adding tetraethylorthosilicate (Si (OC2H5) 4) and propanol to an aqueous solution of phosphotungstic acid hydrate. Was added to amorphous silica powder, stirred at room temperature, allowed to stand, filtered and dried under reduced pressure.

For mixing the monomer solution and the inorganic powder, after mixing these, an appropriate amount of ultrafine amorphous silica was added to adjust the fluidity and stirred to obtain a monomer solution for grafting.
Graft polymerization of the above-mentioned monomer onto the ion-perforated film base is carried out by placing the perforated film base in a stainless steel or glass pressure vessel and pulling it to a sufficient vacuum, preliminarily bubbling with inert gas or freezing degassing to generate oxygen gas. The monomer except for is added, and ⁶⁰ Co-γ rays are irradiated at 5 to 500 kGy in an inert gas at room temperature. Graft polymerization consists of a so-called simultaneous irradiation method in which a perforated film substrate and a monomer are simultaneously irradiated with a radiation, and a so-called post-graft weight in which a perforated film substrate is first irradiated with radiation and then contacted with a monomer to cause a graft reaction. This can be done by any legal method. The graft polymerization temperature is room temperature in the simultaneous irradiation method, and is usually 0 ° C. to 100 ° C. at a temperature below the boiling point of the monomer or solvent in the post-graft polymerization method. Since the presence of oxygen hinders the grafting reaction, these series of operations are performed in an inert gas such as argon gas or nitrogen gas, and the monomer or a solution in which the monomer is dissolved in a solvent is treated in a conventional manner (bubbling or freezing). Use with oxygen removed by degassing.

  The graft ratio (see the formula (1) in the examples) is higher for the simultaneous irradiation method, the higher the radiation dose, or the lower the radiation dose rate and the longer the irradiation time, the higher the graft ratio. The greater the amount, the higher the grafting temperature or the longer the grafting time, the higher the grafting ratio.

As the ionizing radiation, it is preferable to use γ-rays or X-rays having a high substance transmittance, and high-energy electron beams sufficient to pass through the irradiation container, the film substrate or the monomer solution.
Perforation by ion irradiation can be widely applied to organic polymer materials regardless of the constituent molecules and solid structure of the polymer, that is, crystalline or amorphous. In addition to the polyvinylidene fluoride (PVDF) used in one embodiment of the present invention, the polymer film substrate is a high molecular weight polyethylene, polypropylene, polystyrene, polyamide, aromatic polyamide, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyether. A ketone, polyetheretherketone, polyethersulfone, polyphenylene sulfide, or polysulfone film substrate can be used. A polyimide-based polymer film, such as polyimide, polyetherimide, polyamideimide, polybenzimidazole, or polyetheretherimide film base material can also be used. Further, ethylene-tetrafluoroethylene copolymer, polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, or tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer film substrate, which is a fluorine-based polymer May be used. Although these film base materials can use a film base material having no cross-linked structure, the heat resistance of the obtained ion exchange membrane is improved by using a pre-cross-linked film base material. Therefore, it is suitable for high-performance fuel cell membranes operating at high temperatures. For example, when styrene is used as the graft monomer, the cross-linked polytetrafluoroethylene can remarkably increase the graft ratio as compared with uncross-linked polytetrafluoroethylene. The present inventors have already found that double sulfonic acid groups can be introduced into crosslinked polytetrafluoroethylene (Japanese Patent Application Laid-Open No. 2001-348439: Japanese Patent Application No. 2000-170450). A method for producing a tetrafluoroethylene-hexafluoropropylene copolymer or a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer having a crosslinked structure is described in Radiation Physical Chemistry vol. 42, NO. 1/3, pp. 139-142 ( 1993).

In order to introduce a sulfonic acid group into the grafted perforated film obtained above, the [—SO ₂ X ¹ ] group in the grafted molecular chain of the above (1) to (7) is 0.1N to 10N. The sulfonate [—SO ₃ M] (in an aqueous solution of caustic potash (KOH) or caustic soda (NaOH) in a concentration, a water / alcohol solution, or a water / dimethyl sulfoxide solution is reacted at a temperature of room temperature to 100 ° C. or less. In the formula, M is an alkali metal and is Na or K.) Then, a sulfonic acid group is converted into a sulfonic acid group [—SO ₃ H] at 60 ° C. in a 1N to 2N sulfuric acid solution. A membrane is obtained. In addition, the [—SO ₃ R ¹ ] group in the grafted molecular chain is hydrolyzed by reacting at a room temperature to 100 ° C. in an acidic solution such as a sulfuric acid solution having a concentration of 0.1N to 10N, or the same concentration. The polymer ion exchange membrane can be obtained by hydrolyzing it in a potassium hydroxide or sodium solution to form a sulfonic acid group [—SO ₃ H]. Furthermore, the halogen group [—X ² ] in the grafted molecular chain is reacted with an aqueous solution of sulfite or bisulfite, or in a water / alcohol solution, etc. to react with a sulfonate group [—SO ₃ M] (formula M is an alkali metal which is Na or K.) Then, the sulfonate group is converted to a sulfonate group [—SO ₃ H] in the same manner as described above.

  The grafted molecular chain of (8) to (10) above, or the phenyl group, ketone, and ether group in the grafted molecular chain are reacted with a dichloroethane solution or a chloroform solution of chlorosulfonic acid in the graft chain. Sulfonic acid groups can be introduced. In the case of ketone and ether groups, a sulfonic acid group is introduced into the graft chain by dehydrochlorination reaction on these groups and the surrounding structure. In the case of a hydrocarbon-based film base material having an aromatic ring, introduction of a sulfone group by chlorosulfonic acid causes the base material itself to be sulfonated. In this case, a film base material having a crosslinked structure is particularly effective.

  Furthermore, the ester group in the graft chain obtained by (5) to (7) can also be converted to a carboxyl group by reaction with caustic soda (NaOH) or caustic potash (KOH) solution. The carboxyl group is extremely useful for retaining moisture in the film when the ion exchange membrane obtained by the present invention is used as a fuel cell membrane.

Separately from the case of using the above graft reaction, a polymer that does not have a cross-linked structure or has a cross-linked structure, such as polyvinylidene fluoride, ethylene-tetrafluoroethylene copolymer, ultrahigh molecular weight polyethylene, polypropylene, polystyrene, and polyamide. Perforation with high-energy heavy ions is performed on the film substrate, and this is reacted with chlorosulfonic acid to introduce a sulfonic acid group [—SO ₃ H] directly into the film substrate molecular chain to form a polymer ion exchange membrane. It may be manufactured. This is because in the above polymer film substrate, there are —CH ₂ —CH ₂ — units or CH ₂ —CF ₂ — units in the molecule, and many double bonds are present in the irradiation damaged region in the film by heavy ion irradiation. And hydrogen atoms attached to tertiary carbon. And many hydrogen atoms attached to these double bonds and tertiary carbon also remain on the surface of the perforated hole, which reacts with chlorosulfonic acid to fix a high concentration of sulfonic acid groups on the surface of the hole, This is because a polymer ion exchange membrane exhibiting ion exchange ability is obtained.

When fine holes are made in a polymer film substrate using oxygen plasma, fine holes are formed on the sample stage of a normal oxygen plasma irradiation apparatus (for example, HF-8 type reactive ion etching apparatus manufactured by AXIC). A polymer film membrane having a thickness of 50 μm or less with an open SUS metal mask attached is placed. The inside of the apparatus is evacuated, for example, the oxygen pressure is set to about 200 × 10 ⁻³ torr Torr, and oxygen plasma is irradiated at a power of 300 W. Although the approximate perforation speed depends on the type of polymer film substrate, it is about 2 to 4 μm / min, and the through-hole is opened in about 10 to 25 minutes. When some graft monomer penetrates into the polymer film, it may not be a through hole but a non-through hole having a thickness of several μm . After making the holes, the mask is removed, the polymer film is washed with acetone, dried under reduced pressure, and irradiated with radiation to carry out the graft reaction. As the SUS metal mask, one having about 10 ⁵ holes / cm ^{2 having} a diameter of 10 μm φ is used. Another method for making fine holes in a polymer film substrate using oxygen plasma is to deposit aluminum on the polymer film substrate, coat a photoresist on it, and apply light to the photoresist to form a large number of diameters of several μm. Using this as a mask, the aluminum deposited film is etched with acid to make a hole. Further, the polymer film substrate is etched with oxygen plasma using the aluminum deposited film having fine holes as a mask to open a large number of holes. Finally, the deposited aluminum film is removed with an acid to obtain a polymer film substrate having a large number of pores with a diameter of several μm . Perforation of the polymer film substrate by oxygen plasma is effective for all the fluorine-based and hydrocarbon-based polymer film substrates described above.

  In the same manner as the ion perforated polymer film substrate membrane, the above-mentioned monomer and monomer / comonomer system are grafted onto the polymer film substrate perforated by this oxygen plasma with radiation, and caustic potash (KOH) or caustic soda. Treatment with a (NaOH) solution, or a sulfite or bisulfite solution is performed to introduce sulfonic acid groups to produce a polymer ion exchange membrane.

  The polymer ion exchange membrane according to the present invention can change the ion exchange capacity of the resulting membrane by controlling the graft amount and the sulfonation reaction amount, that is, the amount of sulfonic acid groups introduced. The graft reaction tends to be gradually saturated at a graft rate of 60 to 80%. In the present invention, the graft ratio is 10 to 150%, more preferably 15 to 100%, relative to the film substrate.

  Here, the ion exchange capacity is the amount of ion exchange groups (meq / g) per gram of weight of the dry ion exchange membrane. Depending on the type of graft monomer, when the graft rate is 10% or less, the ion exchange capacity is 0.3 meq / g or less, and when the graft rate is 150% or more, the swelling of the membrane increases. That is, the ion exchange capacity is increased by increasing the graft ratio and introducing more ion exchange groups. However, if the amount of ion-exchange groups is excessively large, the membrane swells when it contains water and the strength of the membrane decreases. From these, in the polymer ion exchange membrane of the present invention, the ion exchange capacity is 0.3 meq / g to 2.5 meq / g, preferably 0.5 meq / g to 2.0 meq / g.

In the polymer ion exchange membrane of the present invention, the water content of the membrane can be controlled by selecting the graft substrate, the amount of sulfonic acid groups to be introduced, and the molecular structure of the graft monomer. When this membrane is used as an ion exchange membrane for a fuel cell, if the water content is too low, the electrical conductivity and gas permeability coefficient change due to slight changes in operating conditions, which is not preferable. Since conventional Nafion membranes are mostly composed of —CF ₂ —, when the battery is operated at a high temperature of 80 ° C. or higher, water molecules are insufficient in the membrane, and the conductivity of the membrane rapidly increases. descend.

  In contrast, the ion exchange membrane of the present invention can introduce a hydrophilic group such as a carboxyl group or a hydrocarbon structure in addition to the sulfonic acid group into the graft chain, so that the water content is mainly the amount of the sulfonic acid group. However, it can be controlled in the range of 10 to 120% by weight (wt). In general, the water content increases as the ion exchange capacity increases, but the water content of the ion exchange membrane of the present invention can be 10 to 120 wt%, preferably 20 to 80 wt%.

  The polymer membrane of the present invention maintains the mechanical properties and dimensional stability of the membrane even when a large amount of sulfonic acid groups are introduced up to an ion exchange capacity of about 2.5 meq / g by graft polymerization into the micropores. It can be used practically. Membranes with high ion exchange capacity and excellent mechanical properties are extremely important for practical use.

The higher the electric conductivity related to the ion exchange capacity of the polymer ion exchange membrane, the smaller the electric resistance and the better the performance as an electrolyte membrane. However, when the electric conductivity of the ion exchange membrane at 25 ° C. is 0.05 (Ω · cm) ⁻¹ or less, the output performance as a fuel cell is often significantly reduced. In many cases, the degree is designed to be 0.05 (Ω · cm) ⁻¹ or more, and 0.10 (Ω · cm) ⁻¹ or more for higher performance ion exchange membranes. In the ion exchange membrane according to the present invention, the electric conductivity of the ion exchange membrane at 25 ° C. was equal to or higher than that of the Nafion (registered trademark) membrane. This is probably because ion transmission is relatively high because the ion transmission path is limited to the graft region in the micropores.

  In order to increase the electric conductivity of the ion exchange membrane, it is also conceivable to reduce the thickness of the ion exchange membrane. However, at present, an excessively thin ion exchange membrane is easily damaged, and it is difficult to manufacture the ion exchange membrane itself. Therefore, an ion exchange membrane of 30 to 200 μm is usually used. In the case of the present invention, a film thickness of 10 to 200 μm, preferably 20 to 150 μm is effective.

In the fuel cell membrane, there is methanol which is currently considered as one of the fuel candidates, but the Nafion (registered trademark) membrane, which is a perfluorosulfonic acid membrane, is greatly increased by methanol because there is no intermolecular cross-linking structure. The fuel crossover that swells and diffuses methanol, which is fuel, from the anode (fuel electrode) to the cathode (air electrode) through the cell membrane is a serious problem as it reduces power generation efficiency. However, in the polymer ion exchange membrane according to the present invention, if the film substrate does not permeate methanol, the movement of hydrogen ions occurs through the sulfonated graft chains in the perforations, so the membrane is made of alcohols including methanol. Almost no swelling is observed. For this reason, it is useful as a membrane of a direct methanol fuel cell using methanol directly as a fuel without using a reformer.

  In a fuel cell membrane, the oxidation resistance of the membrane is a very important characteristic related to the durability (life) of the membrane. This is because OH radicals and the like generated during battery operation attack the ion exchange membrane and deteriorate the membrane. A polymer ion exchange membrane obtained by grafting hydrocarbon-based styrene to a polymer film and then sulfonating polystyrene graft chains has extremely low oxidation resistance. For example, a polystyrene graft-crosslinked fluororesin ion exchange membrane sulfonated with a polystyrene chain having a graft rate of 93% deteriorates in about 60 minutes in an aqueous 3% hydrogen peroxide solution at 80 ° C. It becomes half (Comparative Example 3). This is because the polystyrene chain is easily decomposed by the attack of OH radicals.

  In contrast, in the polymer ion exchange membrane according to the present invention, the graft chain is a polymer of a fluorinated monomer or a highly cross-linked product of a hydrocarbon monomer, and the graft is in extremely fine perforations. Oxidation resistance is extremely high, and the ion exchange capacity hardly changes even when placed in a 3% hydrogen peroxide aqueous solution at 80 ° C. for 24 hours or more.

  As described above, the polymer ion exchange membrane of the present invention has excellent dimensional stability, oxidation resistance, and methanol resistance, and has an ion exchange capacity of 0.3 to 2.5 meq, which is an important characteristic of the membrane. / G can be controlled in a wide range.

Hereinafter, although an example and a comparative example explain the present invention, the present invention is not limited to this. In addition, each measured value was calculated | required by the following measurements.
(1) Graft ratio When the film base is a main chain part, and a graft polymerized part of a fluorine monomer or a hydrocarbon monomer and the like is a graft chain part, the weight ratio of the graft chain part to the main chain part is as follows: It is expressed as a graft ratio (X _dg (% by weight)).

(2) Ion Exchange Capacity The ion exchange capacity (I _ex (meq / g)) of the membrane is expressed by the following equation.

For the measurement of n (acid group) _obs , the membrane was again immersed in a 1 M (1 mol) sulfuric acid solution at 50 ° C. for 4 hours for complete accuracy, so that the acid form (H form) was completely obtained. Then, it was immersed in a ₃ M NaCl aqueous solution at 50 ° C. for 4 hours to form —SO ₃ Na type, and the substituted proton (H ⁺ ) was neutralized with 0.2 N NaOH to determine the acid group concentration.

(3) Moisture content After removing the H-type ion exchange membrane stored in water at room temperature from the water and wiping it lightly (after about 1 minute), the weight of the membrane is defined as W _s (g). When the weight W _d (g) of the film when vacuum-dried at 60 ° C. for 16 hours is defined as the dry weight, the water content can be obtained from W _s and W _d by the following equation.

(4) Electrical conductivity The electrical conductivity of ion-exchange membranes was measured by the AC method (New Experimental Chemistry Course 19, Polymer Chemistry <II
>, P. 992, Maruzen), the membrane resistance (R _m ) was measured using a normal membrane resistance measuring cell, a Hewlett Packard LCR meter, E-4925A. The cell was filled with a 1M aqueous sulfuric acid solution, and the resistance between platinum electrodes (distance 5 mm) depending on the presence or absence of the film was measured. The electric conductivity (specific conductivity) of the film was calculated using the following equation.

Cell and potentiostats and functions similar to those of Mark W. Verbrugge, Robert F. Hill et al. (J. Electrochem. Soc., 137 , 3770-3777 (1990)) by DC method for comparison of electrical conductivity measurements. Measured using a generator. There was a good correlation between the measured values of the AC and DC methods. The values in Table 1 below are measured values by the AC method.

(5) Oxidation resistance (weight residual rate%)
The weight of the ion exchange membrane after vacuum drying at 60 ° C. for 16 hours is defined as W _3, and the weight after drying of the ion exchange membrane treated with a 3% hydrogen peroxide solution at 80 ° C. for 24 hours is defined as W ₄ .

(6) Film length swelling degree (%)
The length of one side of a sulfonic acid type membrane in a wet state (water) at room temperature is L ₀ , and the membrane is immersed in a methanol solution under predetermined conditions, and then the same piece of the membrane in a methanol solution wet state at room temperature If the length of L is L _M

Example 1
In order to obtain a crosslinked polyvinylidene fluoride film substrate (hereinafter abbreviated as PVDF), the following irradiation was performed. 10 cm × 10 cm of a 25 μm-thick polyvinylidene fluoride film film (manufactured by Kureha Chemical) was placed in a SUS autoclave irradiation container (inner diameter 7 cmφ × height 30 cm), and the inside of the container was degassed to 10 ⁻³ Torr and replaced with argon gas. Thereafter, ⁶⁰ Co-γ rays were irradiated at a dose rate of 5 kGy / h and a dose of 500 kGy (100 hours) at room temperature. The crosslinked state of the irradiated PVDF film was 80% when the gelation rate was measured with a dimethylformamide solvent.

The obtained cross-linked PVDF was attached to an irradiation stand in an irradiation device (inner diameter 60 cmφ × height 100 cm) in the beam line of the AVF cyclotron accelerator (JAERI, Takasaki Lab), and the inside of the container was deaerated to 10 ⁻⁶ Torr, 450 x MeV Xe (xenon) ions were irradiated in an amount of 3 × 10 ⁸ ions / cm ² . The film was taken out from the irradiation container and immersed in a 9N KOH aqueous solution at 60 ° C. for 100 hours to etch the irradiation damage site by ion irradiation. After sufficiently washing with water and drying, the average size of the pores was measured with a scanning electron microscope and found to be 0.4 μm .

This perforated PVDF film substrate is cut into 2 cm × 2 cm, put into a glass separable container with a cock (inner diameter 3 cmφ × 15 cm height), and further 1,2,2-trifluoroethylenesulfonyl fluoride (CF ₂ ═CF (SO ₂ F)) was added until the film was immersed, and freeze deaeration was repeated to remove monomer liquid and air in the perforated film. Finally, the inside of the glass container was replaced with argon gas and sealed. In this state, the perforated PVDF film was irradiated with gamma rays (dose rate 10 kGy / h) at 300 kGy at room temperature. After irradiation, the mixture was further reacted at 60 ° C. for 24 hours, washed with toluene and then with acetone, and the film was dried. The graft ratio determined by the formula (1) was 18%.

  This graft perforated PVDF film was reacted at 20% by weight in a dimethyl sulfoxide / water (1: 2) solution of KOH at 80 ° C. for 24 hours. After the reaction, the membrane was taken out, washed with water, and treated in a 2N sulfuric acid solution at 60 ° C. for 4 hours. Table 1 below shows the graft ratio, ion exchange capacity (formula (2)), moisture content (formula (3)), and electrical conductivity (formula (4)) of the membrane obtained in this example.

(Example 2)
A polyethylene terephthalate film (made by Hoechst, hereinafter abbreviated as PET) having a thickness of 38 μm is placed in an irradiation apparatus (inner diameter: 60 cmφ × height: 100 cm) in the beam line of the AVF cyclotron accelerator (JAERI, Takasaki Lab) as in Example 1. The container was evacuated to 10 ⁻⁶ Torr, and 450 MeV Xe (xenon) ions were irradiated in an amount of 3 × 10 ⁸ ions / cm ² . The film was taken out from the irradiation container and immersed in a 0.2N NaOH aqueous solution at 70 ° C. for 17 hours to etch a portion damaged by irradiation with ions. After sufficiently washing with water and drying, the average size of the pores was measured with a scanning electron microscope and found to be 0.5 μm .

The obtained perforated polyethylene terephthalate film substrate was cut to 2 cm x 2 cm and placed in a glass separable container with a cock (inner diameter 3 cm φ x 15 cm height), and further, 3-chloro-2,2,3,3-tetrafluoropropoxyoxytri Fluoroethylene (CF ₂ = CF (OCH ₂ (CF ₂ ) ₂ Cl)) was added until the film was immersed, and freeze deaeration was repeated to remove monomer liquid and air in the perforated film. Finally, the inside of the glass container was replaced with argon gas and sealed. In this state, the perforated polyethylene terephthalate film was irradiated with gamma rays (dose rate 10 kGy / h) at 300 kGy at room temperature. After irradiation, the mixture was further reacted at 60 ° C. for 24 hours, washed with toluene and then with acetone, and the film was dried. The graft ratio determined by the formula (1) was 38%.

The grafted polyethylene terephthalate membrane is placed in a pressure-resistant autoclave, and the membrane is immersed in a solution obtained by adding isopropanol (1: 3 (water)) to a 20 wt% aqueous solution of sodium sulfite (Na ₂ SO ₃ ). Was replaced with nitrogen. This autoclave was placed in a 120 ° C. oil bath and allowed to react for 30 minutes. After cooling, the membrane was removed from the autoclave, washed with water, and treated in a 2N sulfuric acid solution at 60 ° C. for 4 hours. Table 1 shows the graft ratio, ion exchange capacity, moisture content, and electrical conductivity of the membrane obtained in this example.
(Example 3)
In the same manner as in Example 1, after irradiating 450 MeV of Xe (xenon) ions in an amount of 3 × 10 ⁸ ions / cm ² , etching treatment was performed in the same manner to produce a perforated PVDF film.

The obtained perforated PVDF film was cut to ₂ cm x ₂ cm and placed in a glass separable container with a cock (inner diameter 3 cm φ x 15 cm height), and further 1,2,2-trifluoroethylenesulfonyl fluoride (CF ₂ = CFSO ₂ F) And a solution of methyl-1,2,2-trifluoroacrylate (CF ₂ = CFCOOCH ₃ ) mixed in a volume ratio of 3: 2 until the film is immersed, and freeze degassing is repeated until the monomer liquid or air in the perforated film Was excluded. Finally, the inside of the glass container was replaced with argon gas and sealed. In this state, the perforated PVDF film was irradiated with γ rays (dose rate 10 kGy / h) at 160 kGy at room temperature. After irradiation, the mixture was further reacted at 60 ° C. for 24 hours. After the reaction, it was washed with toluene and then with acetone and dried. The graft ratio determined by the following formula (1) was 26%.

This graft-perforated PVDF film was reacted at 20% by weight in a dimethyl sulfoxide / water (1: 2) solution of KOH at 80 ° C. for 24 hours. After the reaction, the membrane was taken out, washed with water, and treated in a 2N sulfuric acid solution at 60 ° C. for 4 hours. Table 1 below shows the graft ratio, ion exchange capacity (formula (2)), moisture content (formula (3)), and electrical conductivity (formula (4)) of the membrane obtained in this example.
Example 4
In the same manner as in Example 2, after irradiating 450 MeV of Xe (xenon) ions in an amount of 3 × 10 ⁸ ions / cm ² , etching treatment was performed in the same manner to produce a perforated PVDF film.

The obtained perforated PET film substrate was cut into ₂ cm × ₂ cm, put into a glass separable container (inner diameter 3 cmφ × 15 cm height) with a cock, and further 1,2,2-trifluoroethylenesulfonyl fluoride (CF ₂ = CFSO ₂ F) and methyl-1-fluoroacrylate (CH ₂ = CFCOOCH ₃ ) mixed in a volume ratio of 3: 1 were added until the film was immersed, and freeze deaeration was repeated to remove monomer liquid and air in the perforated film. . Finally, the inside of the glass container was replaced with argon gas and sealed. In this state, the perforated PET film was irradiated with gamma rays (dose rate 10 kGy / h) at 100 kGy at room temperature. After irradiation, the mixture was further reacted at 60 ° C. for 24 hours. After the reaction, it was washed with toluene and then with acetone and dried. The graft ratio determined by the following formula (1) was 48%.

This graft-perforated PET film was treated with a 2N methanol KOH solution for 12 hours and then with a sulfuric acid solution. Table 1 below shows the graft ratio, ion exchange capacity (formula (2)), moisture content (formula (3)), and electrical conductivity (formula (4)) of the membrane obtained in this example.
(Example 5)
In the same manner as in Example 1, after irradiating 450 MeV of Xe (xenon) ions in an amount of 3 × 10 ⁸ ions / cm ² , etching treatment was performed in the same manner to produce a perforated PVDF film.

The obtained perforated PVDF film was cut into 2 cm × 2 cm, put into a glass separable container (inner diameter 3 cmφ × 15 cm height) with a cock, and further, 2-bromo-1,1,2,2-tetrafluoroethoxytrifluoroethylene (CF ₂ = CF (O (CF ₂ ) ₂ Br)) and methyl-1,2,2-trifluoroacrylate (CF ₂ = CFCOOCH ₃ ) mixed in a volume ratio of 3: 2 is added until the film is immersed and frozen. Degassing was repeated to remove monomer liquid and air in the perforated film. Finally, the inside of the glass container was replaced with argon gas and sealed. In this state, the perforated PVDF film was irradiated with γ rays (dose rate 10 kGy / h) at 200 kGy at room temperature. After irradiation, the mixture was further reacted at 60 ° C. for 24 hours. After the reaction, it was washed with toluene and then with acetone and dried. The graft ratio determined by the following formula (1) was 23%.

The grafted PVDF membrane is placed in a pressure-resistant autoclave, and the membrane is immersed in a solution obtained by adding isopropanol (1: 3 (water)) to a 20 wt% aqueous solution of sodium sulfite (Na ₂ SO ₃ ). Replaced with nitrogen. This autoclave was placed in a 120 ° C. oil bath and allowed to react for 30 minutes. After cooling, the membrane was removed from the autoclave, washed with water, and treated in a 2N sulfuric acid solution at 60 ° C. for 4 hours. Table 1 shows the graft ratio, ion exchange capacity, moisture content, and electrical conductivity of the membrane obtained in this example.
(Example 6)
In the same manner as in Example 2, the PET film substrate was irradiated with 3 × 10 ⁸ ions / cm ² of 500 MeV and Au (gold) ions. The film was taken out from the irradiation container and immersed in a 0.2N NaOH aqueous solution at 70 ° C. for 17 hours to etch a portion damaged by irradiation with ions. After sufficiently washing with water and drying, the average size of the pores was measured with a scanning electron microscope and found to be 0.6 μm .

The perforated PET film base material obtained was cut into 2cmx2cm, placed in a pressure-resistant glass separable container with a cock (inner diameter 3cmφx15cm height), and 2-bromo-1,1,2,2-tetrafluoroethoxytri A solution prepared by mixing fluoroethylene (CF ₂ ═CF (O (CF ₂ ) ₂ Br)) and methyl-1-fluoroacrylate (CH ₂ ═CFCOOCH ₃ ) in a volume ratio of 3: 2 is added until the film is immersed, Repeatedly, the monomer liquid and air in the perforated film were removed. Finally, the inside of the glass container was replaced with argon gas and sealed. In this state, the perforated PET film was irradiated with γ rays (dose rate 10 kGy / h) at 200 kGy at room temperature. After irradiation, the mixture was further reacted at 60 ° C. for 24 hours. After the reaction, it was washed with toluene and then with acetone and dried. The graft ratio determined by the following formula (1) was 56%.

This graft-perforated PET film is placed in a pressure-resistant autoclave, and the film is immersed in a solution obtained by adding isopropanol (1: 3 (water)) to a 20 wt% aqueous solution of sodium sulfite (Na ₂ SO ₃ ). Was replaced with nitrogen. This autoclave was placed in a 120 ° C. oil bath and allowed to react for 30 minutes. After cooling, the membrane was removed from the autoclave, washed with water, and treated in a 2N sulfuric acid solution at 60 ° C. for 4 hours. Table 1 shows the graft ratio, ion exchange capacity, moisture content, and electrical conductivity of the membrane obtained in this example.
(Example 7)
In the same manner as in Example 1, after irradiating 450 MeV of Xe (xenon) ions in an amount of 3 × 10 ⁸ ions / cm ² , etching treatment was performed in the same manner to produce a perforated PVDF film.

  The obtained perforated PVDF film was cut into 2 cm × 2 cm, put into a pressure-resistant glass separable container with a cock (inner diameter: 3 cmφ × 15 cm height), deaerated, and then replaced with argon gas. In this state, the PVDF film substrate was irradiated with γ rays (dose rate 2.5 kGy / h) at 60 kGy room temperature. A solution prepared by adding 7vol% divinylbenzene to a mixture of styrene and 2,4-dimethylstyrene, which have been freed of air by freeze degassing, in a volume ratio of 1: 1, is applied to a pressure-resistant glass separable container containing irradiated film. Introduced until soaked. The vessel was sealed with argon gas and post-grafted for 24 hours at 60 ° C. with stirring. After the reaction, it was washed with toluene and then with acetone and dried. The graft ratio determined by the formula (1) was 78%.

The grafted PVDF membrane was sulfonated with a 0.5N chlorosulfonic acid / dichloroethane solution at room temperature. Table 1 shows the graft ratio, ion exchange capacity, moisture content, and electrical conductivity of the membrane obtained in this example.
(Example 8)
The degree of swelling of the membrane with alcohol was measured. The membrane obtained in this example and Nafion 117 were immersed in a 3N sulfuric acid solution to make the sulfonic acid group H-shaped. And it was immersed in room temperature water, and the dimension was measured in the wet state. Next, the membrane was immersed in an aqueous 80 vol% methanol concentration and held at 60 ° C. for 3 hours, and then allowed to cool to room temperature overnight, and then the dimensional change of the membrane was measured. The results are shown in Table 1. The membrane obtained in this example is very effective as a membrane material for a direct methanol fuel cell because the membrane is hardly swollen by methanol as compared with the Nafion membrane. Table 1 demonstrates the effectiveness of the present invention.

Example 9
In the same manner as in Example 1, after irradiating 450 MeV of Xe (xenon) ions in an amount of 3 × 10 ⁸ ions / cm ² , etching treatment was performed in the same manner to produce a perforated PVDF film.

The obtained perforated PVDF film was cut to ₂ cm x ₂ cm and placed in a glass separable container with a cock (inner diameter 3 cm φ x 15 cm height), and 1,2,2-trifluoroethylenesulfonyl fluoride (CF ₂ = CFSO ₂ F) was added to this. 5% by weight of amorphous silica (SiO ₂ : Aerosol, A380) is added to a solution in which 1: 2 and methyl-1,2,2-trifluoroacrylate (CF ₂ = CFCOOCH ₃ ) are mixed at a volume ratio of 3: 2. The added solution was stirred under an ultrasonic wave to make a uniform suspension until the film was immersed, and freeze deaeration was repeated to remove the monomer solution and air in the perforated film. Finally, the inside of the glass container was replaced with argon gas and sealed. In this state, the perforated PVDF film was irradiated with γ rays (dose rate 10 kGy / h) at 160 kGy at room temperature. After irradiation, the mixture was further reacted at 60 ° C. for 24 hours. After the reaction, it was washed with toluene and then with acetone and dried. The graft ratio determined by the following formula (1) was 66%.

This graft-perforated PVDF film was reacted at 20% by weight in a dimethyl sulfoxide / water (1: 2) solution of KOH at 80 ° C. for 24 hours. After the reaction, the membrane was taken out, washed with water, and treated in a 2N sulfuric acid solution at 60 ° C. for 4 hours. Table 2 below shows the graft ratio, ion exchange capacity (formula (2)), moisture content (formula (3)), and electrical conductivity (formula (4)) of the membrane obtained in this example. In addition, according to the method of Example 8, the degree of swelling of the membrane with methanol was measured. This is also shown in Table 2.
(Example 10)
In the same manner as in Example 1, after irradiating 450 MeV of Xe (xenon) ions in an amount of 3 × 10 ⁸ ions / cm ² , etching treatment was performed in the same manner to produce a perforated PVDF film.

The obtained perforated PVDF film was cut to 2 cm × 2 cm and placed in a glass separable container (inner diameter 3 cmφ × 15 cm height) with a cock, and 2-bromo-1,1,2,2-tetrafluoroethoxytrifluoroethylene (CF ₂ = CF (O (CF ₂ ) ₂ Br)) and methyl-1,2,2-trifluoroacrylate (CF ₂ = CFCOOCH ₃ ) mixed in a volume ratio of 3: 2 to a phosphotungstic acid hydrate ( H ₄ PW ₁₂ O ₄₀ · 36H ₂ O) fine powder was added at 5% by weight, and a small amount of amorphous silica (about 1 to 2% by weight) was added to make this solution suspended. The solution was stirred under an ultrasonic wave to make a uniform suspension until the film was immersed, and freeze deaeration was repeated to remove the monomer solution and air in the perforated film. Finally, the inside of the glass container was replaced with argon gas and sealed. In this state, the perforated PVDF film was irradiated with γ rays (dose rate 10 kGy / h) at 160 kGy at room temperature. After irradiation, the mixture was further reacted at 60 ° C. for 24 hours. After the reaction, it was washed with toluene and then with acetone and dried. The graft ratio determined by the following formula (1) was 73%.

This graft-perforated PVDF film was reacted at 20% by weight in a dimethyl sulfoxide / water (1: 2) solution of KOH at 80 ° C. for 24 hours. After the reaction, the membrane was taken out, washed with water, and treated in a 2N sulfuric acid solution at 60 ° C. for 4 hours. Table 2 below shows the graft ratio, ion exchange capacity (formula (2)), moisture content (formula (3)), and electrical conductivity (formula (4)) of the membrane obtained in this example. Further, according to the method of Example 8, the degree of swelling of the membrane with methanol was measured. This is also shown in Table 2.
(Example 11)
In the same manner as in Example 1, after irradiating 450 MeV of Xe (xenon) ions in an amount of 3 × 10 ⁸ ions / cm ² , etching treatment was performed in the same manner to produce a perforated PVDF film .

The obtained perforated PVDF film was cut to ₂ cm x ₂ cm and placed in a glass separable container with a cock (inner diameter 3 cm φ x 15 cm height), and further 1,2,2-trifluoroethylenesulfonyl fluoride (CF ₂ = CFSO ₂ F) Weight ratio of fine powder in which phosphotungstic acid hydrate was adsorbed on the silica surface in a solution in which 1: 2 and methyl-1,2,2-trifluoroacrylate (CF ₂ = CFCOOCH ₃ ) were mixed at a volume ratio of 3: 2. In order to make this monomer solution into a suspension, a small amount of amorphous silica (about 1 to 2% by weight) was added with stirring under ultrasound to obtain a uniform suspension. The solution was added until the film was immersed, and freeze degassing was repeated to remove the monomer liquid and air in the perforated film. Finally, the inside of the glass container was replaced with argon gas and sealed. In this state, the perforated PVDF film was irradiated with γ rays (dose rate 10 kGy / h) at 160 kGy at room temperature. After irradiation, the mixture was further reacted at 60 ° C. for 24 hours. After the reaction, it was washed with toluene and then with acetone and dried. The graft ratio determined by the following formula (1) was 62%.

  This graft perforated PVDF film was reacted at 20% by weight in a dimethyl sulfoxide / water (1: 2) solution of KOH at 80 ° C. for 24 hours. After the reaction, the membrane was taken out, washed with water, and treated in a 2N sulfuric acid solution at 60 ° C. for 4 hours. Table 2 below shows the graft ratio, ion exchange capacity (formula (2)), moisture content (formula (3)), and electrical conductivity (formula (4)) of the membrane obtained in this example. In addition, according to the method of Example 8, the degree of swelling of the membrane with methanol was measured. This is also shown in Table 2.

(Example 12)
In order to obtain a crosslinked polyvinylidene fluoride film substrate, the following irradiation was performed. 10 cm × 10 cm of a 25 μm-thick polyvinylidene fluoride film film (manufactured by Kureha Chemical) was placed in a SUS autoclave irradiation container (inner diameter 7 cmφ × height 30 cm), and the inside of the container was deaerated to 10 ⁻³ Torr and replaced with argon gas. Thereafter, ⁶⁰ Co-γ rays were irradiated at a dose rate of 5 kGy / h and a dose of 500 kGy (100 hours) at room temperature. The crosslinked state of the irradiated PVDF film was 80% when the gelation rate was measured with a dimethylformamide solvent.

Oxygen plasma irradiation device (AXIC Co., HF-8 type reactive ion etching apparatus) 2 cm × hole of the sample stage diameter 10 mu m phi was brought into close contact with about 10 ⁵ / cm ² is made of SUS metal mask 2cmx The above-mentioned crosslinked PVDF membrane having a thickness of 25 μm was placed. The inside of the apparatus was evacuated, the oxygen pressure was set to 190 × 10 ⁻³ Torr, the power was 300 W, and oxygen plasma was irradiated intermittently for 30 minutes. After the plasma irradiation, the mask was removed, and the polymer film was washed with acetone and dried under reduced pressure.

The obtained perforated PVDF film was put into a glass separable container (inner diameter: 3 cmφ × 15 cm height) with a cock, and 2-bromo-1,1,2,2-tetrafluoroethoxytrifluoroethylene (CF ₂ = CF ( O (CF ₂ ) ₂ Br)) and isobutene in a volume ratio of 2: 1 monomer solution are put at 0 ° C. until the film is immersed, and freeze degassing at room temperature / liquid nitrogen temperature is repeated to repeat the monomer solution or perforated film. Removed air. Finally, the inside of the glass container was replaced with argon gas and sealed. In this state, the perforated PVDF film was irradiated with gamma rays (dose rate 10 kGy / h) at 220 kGy room temperature. After irradiation, the mixture was further reacted at 60 ° C. for 24 hours. After the reaction, it was washed with toluene and then with acetone and dried. The graft ratio determined by the following formula (1) was 56%.

This graft-perforated PVDF membrane is placed in a pressure-resistant autoclave, and the membrane is immersed in a solution obtained by adding isopropanol (1: 3 (water)) to a 20 wt% aqueous solution of sodium sulfite (Na ₂ SO ₃ ). Was replaced with nitrogen. This autoclave was placed in a 100 ° C. oil bath and allowed to react for 10 hours. After cooling, the membrane was removed from the autoclave, washed with water, and treated in a 2N sulfuric acid solution at 60 ° C. for 4 hours. The graft ratio, ion exchange capacity, water content, and electrical conductivity of the membrane obtained in this example are shown in Table 3 below. In addition, according to the method of Example 8, the degree of swelling of the membrane with methanol was measured. This is also shown in Table 3.

(Comparative Examples 1 and 2)
The results of ion exchange capacity, water content, and electrical conductivity measured for Nafion 115 and Nafion 117 (manufactured by DuPont) shown in Table 1 below are shown in Comparative Examples 1 and 2 in Table 1.

(Comparative Example 3)
The crosslinked PTFE film (thickness 50 μm) obtained in Example 1 was placed in a glass separable container (inner diameter 3 cmφ × height 15 cm) with a cock, and then purged with argon gas. In this state, the crosslinked PTFE film was again irradiated with γ rays (dose rate 10 kGy / h) at a room temperature of 45 kGy. Styrene monomer, in which oxygen was removed by bubbling with argon gas and replaced with argon gas, was introduced into a glass container containing a crosslinked PTFE film until the membrane was immersed. The container was stirred and reacted at 60 ° C. for 6 hours. Thereafter, the graft copolymer membrane was washed with toluene and then with acetone and dried. The graft rate was 93%. This graft polymerized membrane was immersed in 0.5 M chlorosulfonic acid (1,2-dichloroethane solvent) and subjected to sulfonation reaction at 60 ° C. for 24 hours. Thereafter, this membrane was washed with water to obtain sulfonic acid groups.

Claims (19)

After irradiation damage is formed by irradiating the polymer film substrate with high energy heavy ions, the irradiation damage is chemically etched, and the film substrate has an average diameter of 10 nm or more on the substrate surface. CF ₄ = CF (SO ₂ X ¹ ), which is a monomer having a sulfonyl halide group on the perforated film base material, in which fine cylindrical through holes of 10 ⁴ to 10 ¹⁴ pieces / cm ² are formed. (In the formula, X ¹ is a halogen group and is -F or -Cl. The same applies hereinafter.), CH ₂ = CF (SO ₂ X ¹ ), CF ₂ = CF (O (CF ₂ ) ₁ to ₄ SO ₂ X ¹ ), and CF ₂ = CF (OCH ₂ (CF ₂ ) ₁ to ₄ SO ₂ X ¹ ) to add one or more monomers selected from the group consisting of degassing, γ-ray, X-ray Or ionizing release selected from electron beams What I irradiating the line, the film substrate the monomer is graft-polymerized on the surface and within the pores of, the grafted molecular chain [-SO 2 _X ^1] based on sulfonate [-SO 3 M] _(Formula M is an alkali metal, which is Na or K.), and then a sulfonic acid group [—SO ₃ H]. After irradiation damage is formed by irradiating the polymer film substrate with high energy heavy ions, the irradiation damage is chemically etched, and the film substrate has an average diameter of 10 nm or more on the substrate surface. Formed a fine cylindrical through-hole of 10 ⁴ to 10 ¹⁴ pieces / cm ² , and CF ₂ = CF (SO ₃ R ¹⁾ which is a monomer having a sulfonate group in the obtained perforated film base material (In the formula, R ¹ is an alkyl group which is —CH ₃ , —C ₂ H ₅ or —C (CH ₃ ) _{3. The} same shall apply hereinafter.), CH ₂ = CF (SO ₃ R ¹ ), CF ₂ = One or more selected from the group consisting of CF (O (CF ₂ ) ₁ to ₄ SO ₃ R ¹ ) and CF ₂ ═CF (OCH ₂ (CF ₂ ) ₁ to ₄ SO ₃ R ¹ ) Degas by adding monomer, γ ray, X ray Is it'll be irradiated with ionizing radiation selected from electron beam, by graft polymerizing the monomer on the surface or in the pores of said film base, hydrolyzing the [-SO 3 _R ^1] groups in the grafted molecular chains And a sulfonic acid group [—SO ₃ H]. After irradiation damage is formed by irradiating the polymer film substrate with high energy heavy ions, the irradiation damage is chemically etched, and the film substrate has an average diameter of 10 nm or more on the substrate surface. Are formed into fine cylindrical through-holes of 10 ⁴ to 10 ¹⁴ pieces / cm ² , and CF ₂ = CF (O (CF ₂ ) ₁ to ₄ X ² ) (in the formula, , X ² is a halogen group, which is —Br or —Cl. The same shall apply hereinafter.), And CF ₂ ═CF (OCH ₂ (CF ₂ ) ₁ to ₄ X ² ). The monomer is deaerated by adding an ionizing radiation selected from γ-rays, X-rays, or electron beams to cause the monomer to graft polymerize on the surface of the film substrate or in the pores, thereby grafted molecules. Halogen group in the chain [—X ² ] In an aqueous solution of sulfite or bisulfite or a mixed solution of water and alcohol to give a sulfonate group [—SO ₃ M] (wherein M is an alkali metal and is Na or K), Next, a method for producing a polymer ion exchange membrane, characterized in that the sulfonic acid group [—SO ₃ H] is used. After irradiation damage is formed by irradiating the polymer film substrate with high energy heavy ions, the irradiation damage is chemically etched, and the film substrate has an average diameter of 10 nm or more on the substrate surface. Are formed from 10 ⁴ to 10 ¹⁴ pieces / cm ² of fine cylindrical through-holes, and the obtained perforated film base material has the following groups A to C:
Group ^{_{A: CF 2 = CF (SO 2}} X 1) (.. Wherein, ^{X 1} is is -F or -Cl halogen group hereinafter the ^{_{same), CH 2 = CF (SO}} 2 X 1), CF 2 = _{CF (O (CF 2) 1} ~ 4 SO 2 X 1), and _{CF 2 = CF (OCH 2 (} CF 2) 1 ~ 4 SO 2 X 1);
Group B: CF ₂ ═CF (SO ₃ R ¹ ) (wherein R ¹ is an alkyl group, —CH ₃ , —C ₂ H ₅ , or —C (CH ₃ ) _{3. The} same shall apply hereinafter), CH. ^{_{2 = CF (SO 3 R 1}} ), CF 2 = CF (O (CF 2) 1 ~ 4 SO 3 R 1), and _{CF 2 = CF (OCH 2 (} CF 2) 1 ~ 4 SO 3 R 1); and group _{C; CF 2 = CF (O (} CF 2) 1 ~ 4 X 2) (.. wherein, ^{X 2} is -Br or -Cl halogen group hereinafter), and _CF 2 = _CF (OCH _{2 (CF 2) 1 ~ 4} X 2)
Of the film substrate by adding two or more monomers selected from at least two different groups and degassing and irradiating with ionizing radiation selected from γ-rays, X-rays or electron beams. A method for producing a polymer ion exchange membrane, wherein the monomer is graft-polymerized on the surface or pores, and the functional group in the grafted molecular chain is converted to a sulfonic acid group [—SO ₃ H]. Furthermore, CF ₂ = CR ² (COOR ³ ) (wherein R ² is —CH ₃ or —F, and R ³ is —H, —CH ₃ , —C ₂ H ₅ or —C, which is an acrylic monomer. (CH ₃ ) ₃ ). same as below. ) And one or more comonomers selected from the group consisting of CH ₂ ═CR ² (COOR ³ ) and added in an amount of 50 mol% or less on the basis of the total monomer to perform graft polymerization. 2. A method for producing a polymer ion exchange membrane according to item 1. After irradiation damage is formed by irradiating the polymer film substrate with high energy heavy ions, the irradiation damage is chemically etched, and the film substrate has an average diameter of 10 nm or more on the substrate surface. 10 ⁴ to 10 ¹⁴ pieces / cm ² of fine cylindrical through-holes were formed, and the resulting perforated film substrate was subjected to styrene, α-methylstyrene, styrene derivative monomer 2,4-dimethylstyrene, One or more monomers selected from the group consisting of vinyltoluene and 4-tert-butylstyrene are added to deaerate and irradiated with ionizing radiation selected from γ-rays, X-rays or electron beams. Thus, the monomer is graft-polymerized on the surface or pores of the film substrate, and the grafted molecular chain and the aromatic ring in the molecular chain are sulfonated with chlorosulfonic acid [ And introducing the SO 3 _H], method for producing a polymer ion exchange membrane. After irradiation damage is formed by irradiating the polymer film substrate with high energy heavy ions, the irradiation damage is chemically etched, and the film substrate has an average diameter of 10 nm or more on the substrate surface. 10 ⁴ to 10 ¹⁴ pieces / cm ² of fine cylindrical through-holes are formed, and acenaphthylene, vinyl ketone CH ₂ = CH (COR ⁴ ) (wherein R ⁴ is − CH ₃ , —C ₂ H ₅ , or a phenyl group (—C ₆ H ₅ )), vinyl ether CH ₂ ═CH (OR ⁵ ) (wherein R ⁵ represents —C _n H _{2n + 1} (n = 1 to 1). 5), —CH (CH ₃ ) ₂ , —C (CH ₃ ) ₃ , or a phenyl group.), Fluorinated vinyl ether CF ₂ ═CF (OR ⁵ ) or CH ₂ ═CF (OR ⁵ ), indene, Benzofuran By degassing by adding one or more monomers selected from the group consisting of 5-vinyl-2-norbornene and irradiating with ionizing radiation selected from γ-rays, X-rays or electron beams The monomer is graft-polymerized on the surface or pores of the film substrate, and a sulfonic acid group [—SO ₃ H] is introduced with chlorosulfonic acid into the grafted molecular chain or an aromatic ring in the molecular chain. A method for producing a polymer ion exchange membrane. After irradiation damage is formed by irradiating the polymer film substrate with high energy heavy ions, the irradiation damage is chemically etched, and the film substrate has an average diameter of 10 nm or more on the substrate surface. Are formed into fine cylindrical through-holes of 10 ⁴ to 10 ¹⁴ pieces / cm ² , and the obtained perforated film base material has the following groups D to F:
Group D: styrene, α-methylstyrene, styrene derivative monomers 2,4-dimethylstyrene, vinyltoluene, and 4-tert-butylstyrene; and Group E: acenaphthylene, vinylketone CH ₂ ═CH (COR ⁴ ) (formula In the formula, R ⁴ is —CH ₃ , —C ₂ H ₅ , or a phenyl group (—C ₆ H ₅ ). Vinyl vinyl CH ₂ ═CH (OR ⁵ ) (wherein R ⁵ is —C _n H _{2n + 1} (n = 1 to 5), —CH (CH ₃ ) ₂ , —C (CH ₃ ) ₃ , or phenyl group), fluorovinyl ether CF ₂ ═CF (OR ⁵ ) or CH ₂ ═CF ( oR ^5), indene, benzofuran and 5-vinyl-2-norbornene F ^{_{group: CF 2 = CR 2 (COOR}} 3) ( wherein, ^{R 2} is -CH ₃ or -F, ^{R 3} is -H -CH _{3, -C} 2 _{H 5} or -C _{(CH 3) 3.} The same applies hereinafter.), And ^{_{CH 2 = CR 2 (COOR 3}} )
By adding two or more types of monomers / comonomer selected from each group of the above, degassing, and irradiating with ionizing radiation selected from γ-rays, X-rays or electron beams, the surface and pores of the film substrate Production of a polymer ion-exchange membrane, wherein the monomer is graft-polymerized and a sulfonic acid group [—SO ₃ H] is introduced with chlorosulfonic acid into the grafted molecular chain or an aromatic ring in the molecular chain. Method.   The method for producing a polymer ion exchange membrane according to any one of claims 1 to 8, wherein the graft polymerization is carried out by a simultaneous graft polymerization method.   The method for producing a polymer ion exchange membrane according to any one of claims 1 to 8, wherein the graft polymerization is carried out by a post-graft polymerization method.   Polymer film substrate is polyvinylidene fluoride, ethylene-tetrafluoroethylene copolymer, polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, or tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer film The manufacturing method of the polymer ion exchange membrane of any one of Claims 1-10 which is a base material.   Polymer film substrate is high molecular weight polyethylene, polypropylene, polystyrene, polyamide, aromatic polyamide, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyether ketone, polyether ether ketone, polyether sulfone, polyphenylene sulfide, or polysulfone film group The manufacturing method of the polymer ion exchange membrane of any one of Claims 1-10 which is a material.   The polymer ion exchange membrane according to any one of claims 1 to 10, wherein the polymer film substrate is a polyimide, polyetherimide, polyamideimide, polybenzimidazole, or polyetheretherimide film substrate. Production method.   The method for producing a polymer ion exchange membrane according to any one of claims 1 to 13, wherein the polymer film substrate has a crosslinked structure. In addition, it has divinylbenzene, triallyl cyanurate, triallyl isocyanurate, 3,5-bis (trifluorovinyl) phenol, 3,5-bis (trifluorovinyloxy) phenol and bis (vinylphenyl) groups (CH ₂ ═CH (C ₆ H ₄ )) ₂ (CH ₂ ) _n (n = 1 to 4) and one or more crosslinking agents selected from the group consisting of 30 mol% or less based on the total monomers The method for producing a polymer ion exchange membrane according to any one of claims 1 to 14, wherein graft polymerization is performed. Furthermore, finely divided amorphous silica _(SiO 2) which is an inorganic material in the graft monomer solution, ^{H +} type mordenite _{(Ca, Na 2, K 2} ) Al 2 Si 10 O 24 · 7H 2 O), alumina (Al ₂ O _3), and, one or more powder selected from the group consisting of zirconium oxide (ZrO _2), is graft polymerized in addition in the range of 1% to 30% by weight based on total monomers, claim 1 The manufacturing method of the polymeric ion exchange membrane of any one of -15. Further, zirconium phosphate (Zr (HPO ₄ ) ₂ · nH ₂ O), phosphotungstic acid hydrate (H ₃ PW ₁₂ O ₄₀ · nH ₂ O), silicotungstic acid hydrate (H ₄ SiW ₁₂ O ₄₀ · nH ₂ O) and molybdophosphate hydrate (MoO ₃ H ₃ PO ₄ · nH ₂ O), one or more fine powders selected on the basis of all monomers The method for producing a polymer ion exchange membrane according to any one of claims 1 to 15, wherein the polymer is added in the range of 1% by weight to 30% by weight for graft polymerization.   Further, amorphous silica in which phosphotungstic acid hydrate, zirconium phosphate and silicotungstic acid hydrate are adsorbed in the graft monomer solution, or phosphotungstic acid hydrate, zirconium phosphate and silica. 2. One or more fine powders selected from the group consisting of mordenite and alumina adsorbed with tungstic acid hydrate are added in the range of 1% by weight to 30% by weight based on the total monomers, and graft polymerization is performed. The manufacturing method of the polymeric ion exchange membrane of any one of -15.   The graft ratio of the obtained polymer ion exchange membrane is 10 to 150%, and the ion exchange capacity is 0.3 to 2.5 meq / g, according to any one of claims 1 to 18, A method for producing a polymer ion exchange membrane.