WO2011099213A1 - Anion-exchange resin and fuel cell containing the anion-exchange resin - Google Patents

Abstract

Provided is an anion-exchange resin which is useful especially as the polymer electrolyte membrane of an alkaline fuel cell or as a binder for catalyst layer formation for the cell. The anion-exchange resin has high ionic conductivity and fuel impermeability and has excellent durability. The anion-exchange resin satisfies that (A) the resin has a backbone which contains a repeating unit comprising an aromatic group and an ether group and (B) the repeating unit has a side chain into which an aromatic group and an anion-exchange group have been introduced. The anion-exchange resin preferably is a block copolymer comprising a hydrophilic block containing anion-exchange groups and a hydrophobic block containing substantially no anion-exchange group.

Description

Anion exchange resin and fuel cell containing the anion exchange resin

The present invention relates to an anion exchange resin used for alkaline fuel cells and the like.

In recent years, fuel cells have attracted attention from the viewpoint of environmental problems such as global warming. A fuel cell supplies hydrogen-containing fuels such as hydrogen gas, methanol, and hydrazine and an oxidant such as oxygen to electrodes separated by electrolytes, while oxidizing the fuel on the one hand and reducing the oxidant on the other hand. It generates electricity. Above all, solid polymer fuel cells using a polymer electrolyte membrane as an electrolyte are proactive in applications such as household automobiles because of their relatively low operating temperature and ease of miniaturization and weight reduction. Research has been conducted.

Many of the polymer electrolyte fuel cells that have been studied so far use a cation exchange resin as a polymer electrolyte membrane. This is because the presence of an excellent material such as Nafion (registered trademark) called perfluorofluorine as the polymer electrolyte membrane, and the activity of a catalyst such as platinum used are excellent. However, this polymer electrolyte fuel cell that uses a cation exchange resin as the polymer electrolyte membrane requires the use of a noble metal catalyst such as platinum that is durable in a highly acidic state. Was demanded.

In contrast, in recent years, many polymers using anion exchange resin as a polymer electrolyte membrane have been reported. This so-called alkaline fuel cell using an anion exchange resin as a polymer electrolyte membrane is one of the expected technologies because it is not always necessary to use a precious metal as the catalyst. However, in order to use an anion exchange resin as a polymer electrolyte membrane, high ion conductivity, fuel barrier properties, chemical durability in a power generation atmosphere, mechanical strength, etc. are required. There was no. Patent Document 1 shows a polystyrene base in which a quaternary ammonium salt is introduced as an anion exchange group, and Patent Document 2 shows a polysulfone resin in which a quaternary ammonium salt is introduced as an anion exchange group. ing. However, these materials have been required to be improved because the above-described properties, particularly ionic conductivity, are insufficient. On the other hand, Non-Patent Document 1 discloses an anion exchange resin having a block type polysulfone structure. However, in the structure in which the ion exchange group is introduced into the main chain via an alkyl group, the ionic conductivity is particularly insufficient and improvement has been demanded.

In addition, with respect to the ionic conductivity of the conventional anion exchange resin, as shown in Patent Document 2 and Non-Patent Documents 2 to 5, the measurement conditions are about 2 to 35 mS / cm at room temperature to 30 ° C. in pure water. is there. Although this value can be used as an electrolyte membrane of an alkaline fuel cell, further improvement is required to improve the performance of the alkaline fuel cell, and in consideration of mechanical strength and higher-order structure control, etc. A structure with a high degree of design freedom is required.

JP 2002-119872 A JP 2003-96219 A Japanese Patent Application No. 2009-129881

An object of the present invention is to provide an excellent material as a polymer electrolyte of an alkaline fuel cell, for example. That is, it is an object of the present invention to provide an anion exchange resin having high ionic conductivity and fuel barrier properties and excellent durability.

That is, the present invention includes A) a repeating unit containing an aromatic group and an ether group in the main chain,
B) The anion exchange resin is characterized in that the repeating unit has a side chain into which an aromatic group and an anion exchange group are introduced.

The anion exchange resin is preferably a block copolymer comprising a hydrophilic part block containing an anion exchange group and a hydrophobic part block substantially free of an anion exchange group.

The hydrophobic part block is preferably composed of a repeating unit containing an aromatic group in the main chain.

It is preferable that the number of anion exchange groups introduced into the repeating unit is 0.7 or more per repeating unit.

The anion exchange group is preferably a quaternary ammonium salt.

The side chain into which the aromatic group and the anion exchange group are introduced is represented by the following formula (1):

(In the formula, X is an anion exchange group, m and n are each an integer of 0 or more, and m + n ≧ 1, and one or more X is introduced per fluorenyl structure to form a fluorenyl structure. Or may be introduced into any one of the aromatic rings.)
The fluorenyl structure is preferably included.

The ion exchange capacity is 0.7 meq. / G or more is preferable.

The present invention also relates to a polymer electrolyte membrane comprising the anion exchange resin and a fuel cell catalyst layer comprising the anion exchange resin. The present invention relates to a fuel cell comprising a polymer electrolyte membrane and / or the fuel cell catalyst layer.

According to the present invention, it is possible to provide an anion exchange resin having high ion conductivity and fuel blocking properties and excellent durability. Further, by using this anion exchange resin for the polymer electrolyte membrane and the electrode forming binder, a high performance alkaline fuel cell can be provided.

1 is an NMR chart of the anion exchange resin synthesized in Example 1. FIG. FIG. 2 is an NMR chart of the anion exchange resin synthesized in Example 2. FIG. 3 is a tensile test SS (Strain-Stress) curve of the anion exchange resin synthesized in Examples 1 and 2. FIG. 4 shows the ion conductivity temperature dependence of the anion exchange resins synthesized in Examples 1, 2, and 4. FIG. 5 is an NMR chart of the anion exchange resin synthesized in Example 5. FIG. 6 is a graph showing the relationship between the ionic conductivity and the fuel permeability of the anion exchange resins synthesized in Examples 5 to 8. FIG. 7 is a graph showing the results of a power generation test using the anion exchange resin membrane synthesized in Example 5.

An embodiment of the present invention will be described as follows. The present invention is not limited to the following description.

<1. Anion exchange resin of the present invention>
The anion exchange resin of the present invention is
A) The main chain contains a repeating unit containing an aromatic group and an ether group,
B) The repeating unit has a side chain into which an aromatic group and an anion exchange group are introduced.

The anion exchange resin is preferably a block copolymer composed of a hydrophilic part block containing an anion exchange group and a hydrophobic part block substantially not containing an anion exchange group.

Here, the anion exchange group is a functional group capable of exchanging anions such as hydroxide ions and chloride ions. For example, it is a quaternary ammonium salt, a quaternary phosphonium salt, a tertiary sulfonium salt, a quaternary boronium salt, and the like.

(R ₁ , R ₂ , R ₃ and R ₄ are each independently H, a hydrocarbon group having a functional group such as a hydrocarbon group such as a methyl group, an ethyl group, a methylene group or an ethylene group, or a hydroxyl group, benzyl An aromatic alkylene group such as a group, and at least one is a divalent group such as an alkylene group.)

By introducing such a salt as a functional group into the polymer, performance as an anion exchange resin is expressed. Among these, a quaternary ammonium salt and a quaternary phosphonium salt are preferable because of ease of synthesis and characteristics of the obtained anion exchange resin. Among these, quaternary ammonium salts are particularly preferable from the viewpoint of ionic conductivity.

Here, the number of anion exchange groups in the repeating unit is preferably 0.7 or more on average per repeating unit, more preferably 0.9 or more, and further preferably 1.0 or more. If the number of repeating units is less than this, sufficient ionic conductivity may not be exhibited. In addition to the anion exchange group introduced into the side chain, it is preferable that an anion exchange group is also introduced into the main chain from the viewpoint of ionic conductivity. Thus, a structure in which ion exchange groups are introduced at a high density is preferable because of excellent ion conductivity, which is an important characteristic in the anion exchange resin of the present invention.

The anion exchange resin of the present invention is preferably a block copolymer. The block copolymer is a polymer composed of a block composed of a certain repeating unit and a block composed of a different repeating unit. The length of each block is required to be 3 or more, preferably 5 or more in terms of repeating units. When the number of repeating units is smaller than this, the effect as a block copolymer is hardly exhibited, and the durability which is one of the effects of the present invention may be lowered. The upper limit of the repeating unit is not particularly limited, but is preferably 100 or less. When it exceeds 100, solubility may deteriorate and the blocking reaction for polymerizing the blocks may not proceed. The anion exchange resin of the present invention is a random copolymer in which a repeating unit into which an anion exchange group is introduced and a repeating unit into which an anion exchange group has not been introduced are randomly arranged, as well as each repeating unit. The composition may be a block copolymer, a graft copolymer or the like composed of an oligomer composed of

The anion exchange resin of the present invention comprises at least two or more types of blocks, and at least one of them contains an anion exchange group, that is, preferably a hydrophilic part block, but a repeating unit constituting the hydrophilic part block The number of the anion exchange groups around is preferably 0.7 or more, more preferably 0.9 or more, and further preferably 1.0 or more. If the number of anion exchange groups per repeating unit constituting the hydrophilic block is smaller than this, high ionic conductivity may not be exhibited. In addition, the hydrophobic part block that does not substantially contain anion exchange groups is basically a design in which no anion exchange group exists, and even if it exists, the number of anion exchange groups per repeating unit is hydrophilic part block. 1/10 or less, preferably 1/20 or less. The upper limit of the number of anion exchange groups per repeating unit constituting the hydrophilic block is not particularly limited, but is preferably 4 or less. If the number exceeds 4, the membrane may become water-soluble or brittle.

The anion exchange resin of the present invention has a high ion conductivity, which is one of the objects of the present invention, because the repeating unit has a side chain into which an aromatic group and an anion exchange group are introduced. can get. Preferable examples of such a structure include a phenyl group and a fluorenyl group into which an anion exchange group has been introduced. These are respectively represented by the following general formulas (3) and (1), and are preferable because they are easy to synthesize in addition to high ionic conductivity. Among these, a fluorenyl group into which an anion exchange group has been introduced is excellent in chemical durability and is more preferable.

(In the formula, X represents an anion exchange group. A plurality of X may be introduced.)

(In the formula, X is an anion exchange group, m and n are each an integer of 0 or more, and m + n ≧ 1, and one or more X is introduced per fluorenyl structure to form a fluorenyl structure. Or may be introduced into any one of the aromatic rings.)

Moreover, the anion exchange resin of the present invention has a repeating unit containing an aromatic group and an ether group in the main chain, and the chemical durability is improved by having such a structure. Such a structure having a main chain is widely known as a so-called engineering plastic, such as polyether, polyether sulfide, polyether sulfone, polyether ether sulfone, polyether ketone, polyether ether ketone, polyether sulfone. Examples include ketones, polyetherimides, and polyesters. These have high heat resistance and chemical durability because they have aromatic groups such as phenylene, biphenylene, and naphthylene in the main chain, and also have thermoplastic properties and solvent solubility because they have ether groups. Combined with good processability. Of these main chains, polyethersulfone, polyetherethersulfone, polyetherketone, polyetheretherketone, and polyetherketonesulfone are preferred because of ease of synthesis and ease of introduction of ion exchange groups.

Specific examples of the repeating unit constituting such a main chain include the following general formula group:

(In the formula, Ar represents a group containing a divalent aromatic group, and includes a phenylene group, a naphthylene group, a biphenylene group, a diphenylfluorene group or a derivative thereof;

Etc. are exemplified. A plurality of Ar in the repeating unit may be the same or different, and Ar in each repeating unit may be the same or different. )
The structure shown in FIG.

Among the repeating units constituting the main chain, the following general formula groups are used because of ease of synthesis and ease of introduction of ion exchange groups:

(In the formula, Ar is the same as above.)
The structure shown in FIG. In addition, Ar is preferably a phenylene group or a diphenylfluorene group in view of easy availability of monomers among others.

When the anion exchange resin of the present invention is a block copolymer, and the hydrophilic part block or the hydrophobic part block is composed of a repeating unit containing an aromatic group in the main chain, the repeating unit containing an aromatic group is: It is preferable that it is 50 mol% or more in each block, and it is more preferable that it is 70 mol% or more.

The anion exchange resin of the present invention can be prepared by a conventionally known method. However, for the polymer polymerization method, the polycondensation reaction is simple and can be suitably applied. Regarding the polycondensation reaction, a conventionally known general method (“New Polymer Experiments 3 Polymer Synthesis Method / Reaction (2) Synthesis of Condensation Polymer” p.7-57, p.399-401, ( (1996) Kyoritsu Publishing Co., Ltd.), (J. Am. Chem. Soc., 129, 3879-3887 (2007)), (Eur. Polym. J., 44, 4054-4062 (2008)). For example, there is a method in which a dihalogenated compound and a diol compound are reacted in the presence of a basic compound.

The polycondensation reaction in this example is performed in a polar aprotic solvent. Preferred polar aprotic solvents are dimethyl sulfoxide, sulfolane, pyridine, N-methylpyrrolidone, N-cyclohexyl pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide. N, N-dimethylacetamide and dimethyl sulfoxide are particularly preferred. Two or more polar aprotic solvents may be used as a mixture.

Mixtures of nonpolar, aliphatic, alicyclic or preferably aromatic solvents such as toluene, xylene, chlorobenzene or o-dichlorobenzene, and polar aprotic solvents can also be used. In this case, the volume ratio of the polar aprotic solvent is preferably 50% or more.

In the polycondensation reaction, a basic compound may be added. Preferred basic compounds are lithium carbonate, sodium carbonate, sodium hydrogen carbonate, potassium carbonate, potassium hydrogen carbonate, cesium carbonate, magnesium carbonate, calcium carbonate and other metals; lithium hydroxide, sodium hydroxide, potassium hydroxide and other metals Hydroxides; phosphates such as sodium phosphate, sodium hydrogen phosphate, sodium dihydrogen phosphate, potassium phosphate, potassium hydrogen phosphate, potassium dihydrogen phosphate, and the like. In particular, potassium carbonate is preferable.

The amount of basic compound depends on the amount of dihydroxy aromatic compound to be reacted. In the case of a carbonate compound, the amount is preferably equal to or more than the amount of hydroxyl groups present in the reaction mixture, more preferably 1.2 times excess compound. The reaction temperature is 50 to 300 ° C., and in particular, 100 to 200 ° C. is preferable because reactivity and simple reaction equipment can be used.

When the anion exchange resin of the present invention has a block structure, a general block structure manufacturing method can be applied to the block structure manufacturing method. That is, there are a method of polymerizing several kinds of oligomers in advance, a method of linking them, a method of polymerizing one kind of oligomer, and a method of polymerizing this with a monomer having an excess molar ratio than the oligomer.

The molecular weight of the anion exchange resin of the present invention is preferably in the range of 10,000 to 300,000 in terms of number average molecular weight, and more preferably in the range of 30,000 to 150,000 from the balance of ease of synthesis and solubility in the solvent. . Chemical modification such as introduction of crosslinking is also included in the scope of the present invention in order to suppress swelling due to mechanical strength and moisture. For the method of crosslinking, conventional techniques can be applied, and examples thereof include crosslinking of aromatic groups constituting the main chain with an alkyl group, and crosslinking via a quaternary ammonium salt.

A conventionally known method is used for introducing the anion exchange group. Representative examples include a method of introducing an anion exchange group into a polymer having no anion exchange group, a monomer having an anion exchange group or a precursor thereof polymerized, and the anion exchange group being introduced. There is a method for obtaining a polymer, that is, an anion exchange resin. In view of ease of acquisition, a method in which a polymer having no anion exchange group is synthesized in advance and an anion exchange group is introduced into the polymer is preferable. As an example of such a method, a method of chloromethylation, quaternary ammoniumation, and base treatment will be described in detail.

The chloromethylation reaction is generally performed using a chloromethylating agent in a non-aromatic halogen-based solvent. Examples of non-aromatic halogen solvents used at this time include chloroform, dichloromethane, carbon tetrachloride, 1,2-dichloroethane, 1,1,2-trichloroethane, 1,1,2,2-tetrachloroethane, and the like. Of these, 1,1,2,2-tetrachloroethane is most preferred because of its solubility and suitable boiling point. Examples of the chloromethylating agent include chloromethyl methyl ether, methoxyacetyl chloride, chloromethyl chlorosulfate, etc. Among them, chloromethyl methyl ether is preferable because of easy acquisition and easy reaction control. In the chloromethylation reaction, it is desirable to add a Lewis acid as a catalyst. As the Lewis acid, tin chloride, aluminum chloride, zinc chloride, and the like are suitable, and among them, zinc chloride is most preferable because the reaction progress is mild and there are few side reactions such as a crosslinking reaction. The catalyst equivalent is 0.1 to 10 equivalents, preferably 0.5 to 2 equivalents, relative to the polymer repeating unit. Further, thionyl chloride, silicon tetrachloride, titanium tetrachloride, diphosphorus pentoxide or the like may be used as a cocatalyst. Achieving the desired amount of chloromethyl group introduction and suppressing side reactions such as crosslinking reactions can be achieved by strictly controlling the reaction conditions. As reaction conditions, polymer solution concentration, chloromethyl methyl ether equivalent, reaction temperature, reaction time, and the like are important. The polymer solution concentration is 0.01 to 0.5 repeating unit mol / L, preferably 0.02 to 0.1 repeating unit mol / L in consideration of viscosity and reactivity. Chloromethyl methyl ether is used in an excess amount of 1 to 100 equivalents, preferably 25 to 50 equivalents, based on the polymer repeating unit. The reaction temperature is suitably 20 to 60 ° C., preferably 35 to 40 ° C. in consideration of the progress of the reaction and the suppression of side reactions. Although the reaction time cannot be defined unconditionally because the reactivity varies depending on the polymer structure, it is generally 24 to 168 hours. The optimal reaction time can be found by setting the target introduction amount and monitoring the progress of the reaction with a nuclear magnetic resonance apparatus (hereinafter sometimes abbreviated as NMR). The reagent, solvent, etc. used in the reaction can be easily removed by precipitation purification after completion of the reaction, filtration, drying under reduced pressure, or the like. After purification, the resulting polymer is redissolved in a solvent such as 1,1,2,2-tetrachloroethane, and cast or formed by other methods on a flat glass plate. A translucent and tough precursor film can be obtained.

The quaternary ammonium reaction can also be carried out by immersing the precursor film obtained by casting into a solution of amines, particularly tertiary amines. Tertiary amines include trimethylamine, triethylamine, tributylamine, dimethylpropanolamine, dimethylethanolamine, dimethylamino-2,3-propanol, methyldiethanolamine, pyridine, etc. Among them, quaternized with high basicity. Most preferred is trimethylamine where the reaction proceeds quantitatively fast. Examples of the amine solvent include pure water, methanol, ethanol, and isopropanol, and the concentration is preferably about 20 to 40 wt%. The reaction time for quaternary ammonium formation of the chloromethylated polymer membrane requires a long time, and is preferably 48 hours or more at which quantitative quaternization has been confirmed at room temperature.

The polymer membrane obtained by the quaternary ammonium conversion reaction of the above method has chloride ions as counter ions, and in order to achieve higher anion conductivity, to hydroxide ions with higher ion mobility. It is desirable to replace Counter-ion exchange to hydroxide ions is easily performed in a basic aqueous solution such as sodium hydroxide or potassium hydroxide. It is possible to quantitatively exchange counter ions for hydroxide ions by immersing a quaternary ammonium membrane having chloride ions as counter ions in a base solution of about 1 mol / L for 48 hours or more at room temperature. .

In the above examples, chloride ions and hydroxide ions are shown as counter ions. However, the counter ions can take various types due to the characteristics of the ion exchange resin. For example, if it is left in the air for a long time, it forms a salt with carbonate ions, and if it is in an alkaline atmosphere, it becomes a salt with hydroxide ions. As described above, the counter ion can vary depending on the atmosphere, but the anion exchange resin is substantially the same. In the case of use as an alkaline fuel cell, the counter ion is preferably a hydroxide ion.

The anion exchange resin of the present invention may be a random copolymer comprising the above repeating unit and other repeating units, or a block copolymer comprising an oligomer comprising the above repeating unit and an oligomer comprising the other repeating unit. But it ’s okay.

The ion exchange capacity (hereinafter sometimes abbreviated as IEC) of the anion exchange resin of the present invention is 0.7 to 3.5 [meq. / G] has a performance as an anion exchange resin, and is preferably 0.8 to 3.0 [meq. / G], and more preferably in the range of 1.0 to 3.0 [meq / g] because of excellent balance with mechanical strength. When used as an electrolyte membrane for an alkaline fuel cell, mechanical strength is important from the viewpoint of power generation performance. In this case, 0.8 to 2.5 [meq. / G], more preferably in the range of 1.0 to 2.0 [meq / g].

<2. Polymer electrolyte membrane of the present invention>
The polymer electrolyte membrane of the present invention comprises the anion exchange resin of the present invention. That is, the polymer electrolyte membrane of the present invention is obtained by forming the anion exchange resin of the present invention by an appropriate method. The film forming method is not particularly limited, and a casting method in which an anion exchange resin solution is cast on a flat plate, a method in which a solution is applied on a flat plate by a die coater, a comma coater, a method in which a molten anion exchange resin is stretched, etc. The general method can be adopted. Furthermore, after obtaining the electrolyte membrane, a treatment such as biaxial stretching may be performed to control molecular orientation or the like, or a heat treatment may be performed to control crystallinity and residual stress. Furthermore, it is also within the scope of the present invention to add various fillers in order to increase the mechanical strength of the film or to form a composite with a reinforcing material such as a glass woven fabric, a nonwoven fabric, or a porous body by pressing. A non-woven fabric or a porous material can be impregnated with the anion exchange resin of the present invention and molded into a film. Moreover, you may perform an appropriate chemical process at the time of film forming. For example, crosslinking for increasing the strength of the film, addition of an ionic compound for increasing ionic conductivity, addition of a trace amount of polyvalent metal ions, and the like. In any case, a polymer electrolyte membrane produced using the anion exchange resin according to the present invention in combination with a conventionally known technique is within the scope of the present invention. In addition, in the polymer electrolyte membrane of the present invention, various commonly used additives such as a compatibilizer for improving compatibility, an antioxidant for preventing resin deterioration, and handling in molding processing as a film are improved. These antistatic agents, lubricants and the like can be appropriately used as long as they do not affect the processing and performance of the electrolyte membrane.

As the thickness of the polymer electrolyte membrane of the present invention, any thickness can be selected according to the application. For example, when considering reducing the ionic resistance of the polymer electrolyte membrane, the thinner the membrane, the better. On the other hand, in consideration of the fuel barrier property and handling property of the polymer electrolyte membrane, the resistance to breakage at the time of joining with the electrode, and the like, it may not be preferable if the thickness of the polymer electrolyte membrane is too thin. Considering these, the thickness of the polymer electrolyte membrane is preferably 1.2 μm or more and 350 μm or less, and more preferably 5 μm or more and 200 μm or less. When the thickness of the polymer electrolyte membrane is within this range, the production becomes easy, and wrinkles are hardly generated during processing and drying. In addition, handling is improved such that damage is unlikely to occur.

What is necessary is just to adjust IEC of the polymer electrolyte membrane for fuel cells of this invention by IEC of an anion exchange resin. When the polymer electrolyte membrane includes, for example, a material other than the electrolyte, the IEC as the membrane is thereby lowered, so that the IEC of the electrolyte can be adjusted as appropriate, for example, set higher. The preferred ion exchange capacity for the membrane is 0.8 to 3.5 [meq. / G], more preferably 0.8 to 2.0 [meq. / G]. If the ion exchange capacity is smaller than these lower limits, the preferred ionic conductivity may not be exhibited. If the ion exchange capacity is larger than these upper limits, the mechanical strength may be lowered and sufficient strength may not be obtained. In addition to using the polymer electrolyte of the present invention alone, this polymer electrolyte membrane may be used by mixing with other polymer electrolytes such as other polymer electrolytes.

<3. Fuel Cell Catalyst Layer>
The fuel cell catalyst layer of the present invention is a fuel cell catalyst layer comprising the anion exchange resin of the present invention as an electrode forming binder. The fuel cell catalyst layer generally comprises a metal-containing catalyst, a conductive catalyst carrier, an anion exchange resin as an electrode forming binder, and other additives. As the fuel cell catalyst layer of the present invention, conventionally known materials and production methods can be used. For these, reference can be made to the examples given in the alkaline fuel cell of the present invention described later.

<4. Alkaline fuel cell>
The alkaline fuel cell of the present invention is a fuel cell comprising the anion exchange resin of the present invention. At this time, it may be included as a polymer electrolyte membrane, a binder for electrode formation, or both. An alkaline fuel cell is a type of fuel cell that is composed of a fuel electrode and an oxidizer electrode separated by an anion exchanger such as an anion exchange resin, and is characterized by hydroxide in the anion exchanger. Ions move and create an energization of an external circuit, that is, a power generation state. Here, oxygen or air is used as the oxidizing agent, and hydrogen-containing substances such as alcohol and hydrazine are used as the fuel, in addition to hydrogen.

The alkaline fuel cell of the present invention is a conventionally known one. As specific implementation methods, alkaline fuels known in JP-A-11-135137, JP-A-2009-9769, JP-A-2009-26665, JP-A-2006-244961, and the like are known. It can be used as a polymer electrolyte membrane for a battery or a binder for electrode formation. Based on these known documents, those skilled in the art can easily construct an alkaline fuel cell using the anion exchange resin of the present invention.

EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited at all by these Examples, In the range which does not change the summary, it can change suitably.

Example 1
<Synthesis of poly (arylene ether sulfone ketone)>
Recrystallized and purified fluorophenylsulfone (2.54 g, manufactured by Tokyo Chemical Industry Co., Ltd.), difluorobenzophenone (2.18 g, manufactured by Tokyo Chemical Industry Co., Ltd.), 9,9′-bis (4-hydroxyphenyl) fluorene (7.00 g, manufactured by Tokyo Chemical Industry Co., Ltd.) was dissolved in dehydrated N, N-dimethylacetamide (120 ml, manufactured by Kanto Chemical Co., Ltd.), and potassium carbonate (3.80 g, manufactured by Kanto Chemical Co., Inc.). ) And toluene (12 ml, manufactured by Kanto Chemical Co., Inc.) were added and reacted at 145 ° C. for 3 hours and 160 ° C. for 1 hour. Subsequently, it is purified by precipitation in pure water, and the precipitate is filtered and collected, washed repeatedly in pure water and methanol, purified in a dichloromethane / acetone mixed solvent, and then heated and dried in a vacuum for 12 hours. About 7.4 g of (arylene ether sulfone ketone) was obtained. The number average molecular weight of the obtained polymer was about 60,000, and the weight average molecular weight was about 220,000 (measured by gel permeation chromatography). Moreover, it confirmed by NMR measurement that the target structure was obtained.

<Chloromethylation reaction, cast film formation>
1 g of poly (arylene ether sulfone ketone) was dissolved in 1,1,2,2-tetrachloroethane (20 ml, manufactured by Kanto Chemical Co., Inc.), and chloromethyl methyl ether (2.96 ml, manufactured by Kanto Chemical Co., Inc.) Zinc chloride (0.125 g, manufactured by Kanto Chemical Co., Inc.) dissolved in THF (1 ml) was added and reacted at 35 ° C. for 168 hours. After completion of the reaction, the mixture was purified by precipitation in methanol, washed repeatedly in methanol, the precipitate was collected by filtration, and dried in a vacuum for 12 hours to obtain about 1.1 g of chloromethylated polyether. The amount of chloromethyl group introduced was calculated from the proton integration ratio of NMR measurement, and the amount introduced in this reaction was 1.80 per repeating unit. Subsequently, 1 g of the obtained chloromethylated polyether was dissolved in 16 ml of 1,1,2,2-tetrachloroethane, cast on a flat glass plate, and the solvent was dried at 60 ° C. under normal pressure. The obtained transparent and tough film was washed in pure water and methanol and heated and vacuum dried for 12 hours to obtain a chloromethylated polyether film.

<Quaternary ammonium reaction, base treatment>
The chloromethylated polyether film was immersed in a 30 wt% trimethylamine aqueous solution (100 ml, manufactured by Kanto Chemical Co., Inc.) for 48 hours at room temperature to carry out a quaternary ammonium reaction. After completion of the reaction, washing was repeated with pure water, followed by immersion in a 1 mol / L aqueous sodium hydroxide solution at room temperature for 48 hours to exchange counter ions from chloride ions to hydroxide ions. After the base treatment, it was repeatedly washed with pure water and dried in a vacuum for 12 hours to obtain a quaternary ammonium-modified polyether film. The quaternary ammonium reaction and the base treatment proceeded quantitatively, the thickness of the obtained polymer electrolyte membrane was about 50 μm, and the IEC was calculated to be 2.54 meq / g.

The structure of the obtained Example 1 is shown in the following formula (4), and the NMR chart is shown in FIG.

(In the formula, the subscript 50 beside the repeating unit indicates the ratio of the repeating unit. In the formula, four groups containing a quaternary ammonium salt which is an anion exchange group of the repeating unit are shown in the expression. Actually, 1.80.)

Example 2
Poly (arylene ether decafluorobiphenyl) was synthesized as follows. N, N obtained by dehydrating decafluorobiphenyl (4.00 g, manufactured by Tokyo Chemical Industry Co., Ltd.), 9,9′-bis (4-hydroxyphenyl) fluorene (7.00 g, manufactured by Tokyo Chemical Industry Co., Ltd.) -Dissolved in dimethylacetamide (120 ml, manufactured by Kanto Chemical Co., Inc.), added potassium carbonate (3.80 g, manufactured by Kanto Chemical Co., Ltd.) and toluene (12 ml, manufactured by Kanto Chemical Co., Ltd.), and added 3 at 145 ° C. The reaction was performed at 160 ° C. for 1 hour. After the reaction, purification and evaluation were conducted in the same manner as in Example 1. The number average molecular weight of the obtained polymer was about 60,000, and the weight average molecular weight was about 230,000. Next, a chloromethylation reaction was carried out under the same conditions as in Example 1, and 1.17 chloromethyl groups were introduced per repeating unit for 96 hours. Subsequently, cast film formation, quaternary ammonium conversion reaction, and base treatment were performed in the same manner as in Example 1 to obtain the target quaternary ammonium conversion polyether film. The thickness of the obtained film was about 55 μm, and the IEC was 1.56 meq / g.

The structure of the obtained Example 2 is shown in the following formula (5), and the NMR chart is shown in FIG.

(In the formula, the subscript n next to the repeating unit indicates the number of repeating units. In the formula, four groups containing a quaternary ammonium salt which is an anion exchange group are shown in terms of expression. .17.)

Example 3
To obtain quaternary ammonium-modified polyether membranes with different IEC, chloromethylation reaction of poly (arylene ether sulfone ketone) was carried out under different conditions. 1 g of poly (arylene ether sulfone ketone) is dissolved in 1,1,2,2-tetrachloroethane (20 ml, manufactured by Kanto Chemical Co., Inc.), and chloromethyl methyl ether (1.85 ml, manufactured by Kanto Chemical Co., Inc.) Zinc chloride (0.125 g, manufactured by Kanto Chemical Co., Inc.) dissolved in THF (1 ml) was added and reacted at 40 ° C. for 72 hours. As a result, the chloromethyl group introduction amount was calculated to be 1.35 per repeating unit. The obtained chloromethylated polyether was derived into quaternary ammonium in the same manner as in Example 1, and after base treatment, the thickness of the polymer electrolyte membrane was about 50 μm, and the IEC 2.08 meq / g quaternary ammonium was formed. A polyether film was obtained.

Example 4
As another method for obtaining a quaternary ammonium-modified polyether film having a different IEC, the reaction time was controlled. Chloromethylation of poly (arylene ether sulfone ketone) was carried out under the same conditions as in Example 1 with a reaction time of only 120 hours. As a result, the chloromethyl group introduction amount was calculated to be 1.24 per repeating unit. The obtained chloromethylated polyether was derivatized to quaternary ammonium in the same manner as in Example 1, and after base treatment, the thickness of the polymer electrolyte membrane was about 70 μm, and the IEC was 1.88 meq / g quaternary ammonium. A polyether film was obtained.

The characteristics of the polymer electrolyte membrane made of the anion exchange resin of the above example were evaluated. The evaluation method is as follows.

(Measurement of ion exchange capacity)
The ion exchange capacity of the quaternary ammonium-modified polyether membrane was calculated by the following two types of titration. The quaternary ammonium-modified polyether membrane having hydroxide ions as counter ions was cut out to about 50 mg, weighed, and salt-exchanged by immersing in saturated saline solution at room temperature overnight. Subsequently, after dilution with pure water, titration was performed with 0.01 M hydrochloric acid. The neutralization point was judged using an automatic titrator (AT510 manufactured by KEM), and the ion exchange capacity was calculated from the amount of hydrochloric acid required for neutralization. Further, the quaternary ammonium-modified polyether membrane having chloride ions as counter ions was subjected to salt exchange with sodium nitrate. Subsequently, an aqueous silver nitrate solution was dropped using a burette with potassium chromate as an indicator, and the ion exchange capacity was calculated from the amount of the aqueous silver nitrate solution required for neutralization, with the point where the reddish brown precipitate was generated as the neutralization point.

(Calculation of the number of anion exchange groups introduced per repeating unit)
The polymer obtained by the chloromethylation reaction was subjected to ¹ H-NMR measurement, and the number of introduced chloromethyl groups or ammonium groups was calculated from the ratio of integral values. Specifically, a signal peak that does not change before and after the reaction of poly (arylene ether sulfone ketone) (ortho proton of sulfone and ketone, positions 4 and 5 of fluorene) and a methylene peak in a chloromethyl group, or an adjacent ammonium group The number of introductions was calculated from the integral ratio of methyl and methylene.

(Ion conductivity measurement)
The base-treated quaternary ammonium-modified polyether film was cut into 1 cm x 3 cm squares and set on a PEEK 4-terminal holder with 4 gold wires (distance between the center electrodes 1 cm). The holder was sandwiched, and the entire holder was immersed in pure water whose temperature was arbitrarily adjusted. The pure water temperature was adjusted to the target temperature, and after standing, AC impedance measurement was performed using an impedance measuring device (Solartron 1255B manufactured by Solartron). The ionic conductivity was calculated from the obtained Nyquist plot and the physical constants of the membrane under a constant voltage and in a frequency range of 1 to 100,000 Hz. FIG. 4 shows the temperature dependence of ion conductivity of the anion exchange resins synthesized in Examples 1, 2, and 4.

(Measurement of breaking strength)
The measurement was performed by a tensile tester (AGS-J500N manufactured by Shimadzu Corporation) installed in a thermostatic chamber. At this time, the sample shape was a dumbbell type (DIN-53504-S3), and the pulling speed was 10 mm / min. The constant temperature and humidity layer was set at 80 ° C. and 60% RH, and the sample was held for about 2 hours. FIG. 3 shows a tensile test SS (Strain-Stress) curve of the anion exchange resin synthesized in Examples 1 and 2.

Table 1 shows the characteristics of Examples 1 to 4. It turns out that the anion exchange resin of this invention has the ionic conductivity excellent with respect to the anion exchange resin of a well-known technique. It can also be seen that the breaking strength has a higher value than 19.0 MPa of Nafion (registered trademark) generally used as a cation exchange resin.

From the above, it was found that the anion exchange resin of the present invention has excellent ionic conductivity and mechanical strength and is excellent as a material for alkaline fuel cells.

Example 5
<Synthesis of poly (arylene ether sulfone ketone)>
Multiblock poly (arylene ether sulfone ketone) was obtained by multiblock copolymerization of a hydrophilic oligomer and a hydrophobic oligomer. First, a hydrophilic oligomer was synthesized by the following procedure. N, N- dehydrated difluorobenzophenone (3.00 g, manufactured by Tokyo Chemical Industry Co., Ltd.), 9,9′-bis (4-hydroxyphenyl) fluorene (4.65 g, manufactured by Tokyo Chemical Industry Co., Ltd.) Dissolve in dimethylacetamide (40 ml, manufactured by Kanto Chemical Co., Inc.), add potassium carbonate (4.59 g, manufactured by Kanto Chemical Co., Ltd.) and toluene (10 ml, manufactured by Kanto Chemical Co., Inc.), and heat at 140 ° C. for 2 hours. , Reacted at 165 ° C. for 2 hours. Subsequently, the precipitate was purified in pure water, and the precipitate was filtered and collected, washed repeatedly in pure water and methanol, purified in a dichloromethane / acetone mixed solvent, and then dried in a vacuum for 12 hours by heating and drying. About 6.9 g of functional oligo (arylene ether sulfone) was obtained. The number average molecular weight of the obtained polymer was 5300, and the weight average molecular weight was 13100 (measured by gel permeation chromatography). Moreover, it confirmed that the chain length y of the hydrophilic component was about the target 8 from NMR measurement.

Next, a hydrophobic oligomer was synthesized by the following procedure. N, N-dimethylacetamide (20 ml, Kanto) obtained by dehydrating difluorobenzophenone (2.00 g, manufactured by Tokyo Chemical Industry Co., Ltd.) and 4,4′-dihydroxybenzophenone (1.50 g, manufactured by Tokyo Chemical Industry Co., Ltd.) Dissolved in Chemical Co., Ltd.), potassium carbonate (2.42 g, manufactured by Kanto Chemical Co., Ltd.) and toluene (7 ml, manufactured by Kanto Chemical Co., Ltd.) were added, and the mixture was heated at 150 ° C for 1.5 hours and at 170 ° C. The reaction was allowed for 1.5 hours.

Subsequently, the hydrophilic oligomer (4.26 g) synthesized in advance above was added, and the mixture was further reacted at 170 ° C. for 2 hours. After completion of the reaction, the mixture was purified by precipitation in dilute hydrochloric acid. The precipitate was collected by filtration, washed repeatedly in pure water, methanol / hydrochloric acid and methanol, purified in a mixed solvent of dichloromethane / acetone, and then dried in a vacuum for 12 hours. As a result, about 5.8 g of multi-block type poly (arylene ether sulfone ketone) was obtained. The obtained polymer had a number average molecular weight of about 90,000 and a weight average molecular weight of about 180,000 (measured by gel permeation chromatography). Further, it was confirmed by NMR measurement that the target structure, that is, the hydrophobic part chain length x was about 8, and the hydrophilic part chain length y was about 8.

<Chloromethylation reaction, cast film formation>
1 g of multi-block poly (arylene ether sulfone ketone) is dissolved in 1,1,2,2-tetrachloroethane (18.6 ml, manufactured by Kanto Chemical Co., Inc.), and chloromethyl methyl ether (6.19 ml, Kanto Chemical ( Zinc chloride (0.116 g, manufactured by Kanto Chemical Co., Inc.) dissolved in THF (1 ml) was added and reacted at 45 ° C. for 144 hours. After completion of the reaction, the mixture was purified by precipitation in methanol, washed repeatedly in methanol, the precipitate was collected by filtration, and dried in a vacuum for 12 hours to obtain about 1.1 g of chloromethylated polyether. The amount of chloromethyl group introduced was calculated from the proton integration ratio of NMR measurement, and the amount introduced in this reaction was 2.78 per repeating unit. Subsequently, 1 g of the obtained chloromethylated polyether was dissolved in 16 ml of 1,1,2,2-tetrachloroethane, cast on a flat glass plate, and the solvent was dried at 60 ° C. under normal pressure. The obtained transparent and tough film was washed in pure water and methanol and heated and vacuum dried for 12 hours to obtain a chloromethylated block polyether film. The thickness of the obtained polymer electrolyte membrane was about 60 μm.

<Quaternary ammonium reaction, base treatment>
The chloromethylated block polyether film was immersed in a 30 wt% trimethylamine aqueous solution (100 ml, manufactured by Kanto Chemical Co., Inc.) for 48 hours at room temperature to carry out a quaternary ammonium reaction. After completion of the reaction, washing was repeated with pure water, followed by immersion in a 1 mol / L aqueous sodium hydroxide solution at room temperature for 48 hours to exchange counter ions from chloride ions to hydroxide ions. After the base treatment, it was repeatedly washed with pure water and dried in a vacuum for 12 hours to obtain a quaternary ammonium-modified polyether film. The quaternary ammonium reaction and the base treatment proceed quantitatively, and the IEC of the obtained membrane is 1.93 meq. / G. The structure of the obtained anion exchange resin of Example 5 is shown in the following formula (6), and the NMR chart is shown in FIG.

(Wherein, x and y are the number of repeating units, respectively, and are about 8 and 8 respectively in this example. In the formula, a quaternary ammonium salt which is an anion exchange group of the repeating unit of the hydrophilic block is included. (4 groups are shown in the representation, but the average is actually 2.78.)

Example 6
<Synthesis of poly (arylene ether sulfone ketone)>
The same hydrophilic oligomer and hydrophobic oligomer and multiblock copolymerization reaction as in Example 5 were used. The obtained polymer had a number average molecular weight of about 50,000 and a weight average molecular weight of about 100,000 (measured by gel permeation chromatography). Further, it was confirmed by NMR measurement that the intended structure, that is, the hydrophobic part chain length x was about 16 and the hydrophilic part chain length y was about 11 was obtained.

<Chloromethylation reaction, cast film formation>
1 g of multi-block poly (arylene ether sulfone ketone) is dissolved in 1,1,2,2-tetrachloroethane (18.6 ml, manufactured by Kanto Chemical Co., Inc.), and chloromethyl methyl ether (6.19 ml, Kanto Chemical ( Zinc chloride (0.116 g, manufactured by Kanto Chemical Co., Inc.) dissolved in THF (1 ml) was added and reacted at 35 ° C. for 96 hours. After completion of the reaction, the mixture was purified by precipitation in methanol, washed repeatedly in methanol, and the precipitate was collected by filtration and dried in a vacuum for 12 hours to obtain about 1.0 g of chloromethylated polyether. The amount of chloromethyl group introduced was calculated from the proton integration ratio of NMR measurement, and the amount introduced in this reaction was 1.78 per repeating unit. Subsequently, 1 g of the obtained chloromethylated polyether was dissolved in 16 ml of 1,1,2,2-tetrachloroethane, cast on a flat glass plate, and the solvent was dried at 60 ° C. under normal pressure. The obtained transparent and tough film was washed in pure water and methanol and heated and vacuum dried for 12 hours to obtain a chloromethylated block polyether film. The thickness of the obtained polymer electrolyte membrane was about 60 μm.

<Quaternary ammonium reaction, base treatment>
The same quaternary ammonium reaction and base treatment as in Example 5 were performed. The quaternary ammonium reaction and the base treatment proceed quantitatively, and the IEC of the obtained membrane is 1.32 meq. / G. The structure of the obtained anion exchange resin of Example 6 is the same as that of Formula (6).

Example 7
<Synthesis of poly (arylene ether sulfone ketone)>
The same hydrophilic oligomer and hydrophobic oligomer as in Example 1 and multiblock copolymerization reaction were used. The number average molecular weight of the obtained polymer was about 90,000, and the weight average molecular weight was about 180,000 (measured by gel permeation chromatography). Further, it was confirmed from NMR measurement that the intended structure, that is, the hydrophobic part chain length x and the hydrophilic part chain length y were each about 8.

<Chloromethylation reaction, cast film formation>
1 g of multi-block poly (arylene ether sulfone ketone) is dissolved in 1,1,2,2-tetrachloroethane (18.6 ml, manufactured by Kanto Chemical Co., Inc.), and chloromethyl methyl ether (6.19 ml, Kanto Chemical ( Zinc chloride (0.116 g, manufactured by Kanto Chemical Co., Inc.) dissolved in THF (1 ml) was added and reacted at 35 ° C. for 125 hours. After completion of the reaction, the mixture was purified by precipitation in methanol, washed repeatedly in methanol, the precipitate was collected by filtration, and dried in a vacuum for 12 hours to obtain about 1.1 g of chloromethylated polyether. The amount of chloromethyl group introduced was calculated from the proton integration ratio of NMR measurement, and the amount introduced in this reaction was 0.92 per repeating unit. Subsequently, 1 g of the obtained chloromethylated polyether was dissolved in 16 ml of 1,1,2,2-tetrachloroethane, cast on a flat glass plate, and the solvent was dried at 60 ° C. under normal pressure. The obtained transparent and tough film was washed in pure water and methanol and heated and vacuum dried for 12 hours to obtain a chloromethylated block polyether film. The thickness of the obtained polymer electrolyte membrane was about 80 μm.

<Quaternary ammonium reaction, base treatment>
The same quaternary ammonium reaction and base treatment as in Example 1 were performed. The quaternary ammonium reaction and base treatment proceeded quantitatively, and the IEC of the obtained membrane was 0.89 meq. / G. The structure of the obtained anion exchange resin of Example 7 was the same as in formula (6), except that the number of repeating units x and y were 7.6 and 8.5, respectively.

Example 8
<Synthesis of random poly (arylene ether sulfone ketone)>
Recrystallized and purified fluorophenylsulfone (1.40 g, manufactured by Tokyo Chemical Industry Co., Ltd.), difluorobenzophenone (1.20 g, manufactured by Tokyo Chemical Industry Co., Ltd.), 9,9′-bis (4-hydroxyphenyl) fluorene (3.85 g, manufactured by Tokyo Chemical Industry Co., Ltd.) was dissolved in dehydrated N, N-dimethylacetamide (60 ml, manufactured by Kanto Chemical Co., Ltd.), and potassium carbonate (3.79 g, Kanto Chemical Co., Ltd.) was dissolved. And toluene (6 ml, manufactured by Kanto Chemical Co., Inc.) were added and reacted at 145 ° C. for 3 hours and 160 ° C. for 1 hour. Subsequently, it is purified by precipitation in pure water, and the precipitate is filtered and collected, washed repeatedly in pure water and methanol, purified in a dichloromethane / acetone mixed solvent, and then heated and dried in a vacuum for 12 hours. About 4.8 g of (arylene ether sulfone ketone) was obtained. The number average molecular weight of the obtained polymer was about 40,000, and the weight average molecular weight was about 80,000 (measured by gel permeation chromatography). Moreover, it confirmed by NMR measurement that the target structure was obtained.

<Chloromethylation reaction, cast film formation>
1 g of random poly (arylene ether sulfone ketone) is dissolved in 1,1,2,2-tetrachloroethane (20 ml, manufactured by Kanto Chemical Co., Inc.) and chloromethyl methyl ether (2.78 ml, manufactured by Kanto Chemical Co., Inc.). ), Zinc chloride (0.125 g, manufactured by Kanto Chemical Co., Inc.) dissolved in THF (1 ml) was added and reacted at 35 ° C. for 78 hours. After completion of the reaction, the mixture was purified by precipitation in methanol, washed repeatedly in methanol, and the precipitate was collected by filtration and dried in a vacuum for 12 hours to obtain about 1.0 g of chloromethylated polyether. The amount of chloromethyl group introduced was calculated from the proton integration ratio of NMR measurement, and the amount introduced in this reaction was 0.92 per repeating unit. Subsequently, 1 g of the obtained chloromethylated polyether was dissolved in 16 ml of 1,1,2,2-tetrachloroethane, cast on a flat glass plate, and the solvent was dried at 60 ° C. under normal pressure. The obtained transparent and tough film was washed in pure water and methanol and heated and vacuum dried for 12 hours to obtain a chloromethylated polyether film. The thickness of the obtained polymer electrolyte membrane was about 70 μm.

<Quaternary ammonium reaction, base treatment>
The chloromethylated polyether film was immersed in a 30 wt% trimethylamine aqueous solution (100 ml, manufactured by Kanto Chemical Co., Inc.) for 48 hours at room temperature to carry out a quaternary ammonium reaction. After completion of the reaction, washing was repeated with pure water, followed by immersion in a 1 mol / L aqueous sodium hydroxide solution at room temperature for 48 hours to exchange counter ions from chloride ions to hydroxide ions. After the base treatment, it was repeatedly washed with pure water and dried in a vacuum for 12 hours to obtain a quaternary ammonium-modified polyether film. The quaternary ammonium reaction and base treatment proceeded quantitatively, and the IEC of the obtained membrane was 1.46 meq. / G.

The characteristics of the polymer electrolyte membrane made of the anion exchange resin of the above example were evaluated. The method is as follows.

(Measurement of ion exchange capacity)
The ion exchange capacity of the polymer electrolyte membrane made of the anion exchange resin of the above example was calculated by the following two types of titration. The quaternary ammonium-modified polyether membrane having hydroxide ions as counter ions was cut out to about 50 mg, weighed, and salt-exchanged by immersing in saturated saline solution at room temperature overnight. Subsequently, after dilution with pure water, titration was performed with 0.01 M hydrochloric acid. The neutralization point was judged using an automatic titrator (AT510 manufactured by KEM), and the ion exchange capacity was calculated from the amount of hydrochloric acid required for neutralization. Further, the quaternary ammonium-modified polyether membrane having chloride ions as counter ions was subjected to salt exchange with sodium nitrate. Subsequently, an aqueous silver nitrate solution was dropped using a burette with potassium chromate as an indicator, and the ion exchange capacity was calculated from the amount of the aqueous silver nitrate solution required for neutralization, using the point where the reddish brown precipitate was formed as the neutralization point.

(Calculation of the number of anion exchange groups introduced per repeating unit)
The polymer obtained by the chloromethylation reaction was subjected to ¹ H-NMR measurement, and the number of introduced chloromethyl groups or ammonium groups was calculated from the ratio of integral values. Specifically, from the ratio of the proton integral value in the hydrophilic biphenylsulfone skeleton near 7.8 ppm that does not change before and after the chloromethylation reaction and the methylene proton integral value of the chloromethyl group near 4.6 ppm, the chloromethyl group The number of introduced was calculated. Similarly, in the polymer after the quaternary ammonium reaction, the proton integral value near 8.2 to 7.4 ppm and the proton integral value of methylene (near 5.9 ppm) and terminal methyl (near 3.0 ppm) in the ammonium group. From the ratio, the number of introduced ammonium groups was calculated.

(Ion conductivity measurement)
The base-treated polymer electrolyte membrane made of the anion exchange resin of the above example was cut into 1 cm × 3 cm squares and set on a PEEK 4-terminal holder having four gold wires (distance between the center electrodes 1 cm), 4 The sample was sandwiched between another holder without a terminal and immersed in pure water with the temperature adjusted arbitrarily. The pure water temperature was adjusted to the target temperature, and after standing, AC impedance measurement was performed using an impedance measuring device (Solartron 1255B manufactured by Solartron). The ionic conductivity was calculated from the obtained Nyquist plot and the physical constant of the membrane under a constant voltage in the frequency range of 1 to 100,000 Hz. Higher ionic conductivity is preferred.

(Measurement of fuel permeability)
One of the fuels used for alkaline fuel cells is an aqueous hydrazine solution. In this measurement, assuming that the fuel is hydrazine, the fuel permeability of the polymer electrolyte membrane made of the anion exchange resin of the above example was measured by the following method.

A polymer electrolyte membrane cut out to a size of about 4 cm × 4 cm was sandwiched between H-type cells for permeation tests, and the screws of the stoppers were firmly tightened. A 10 wt% hydrazine aqueous solution was injected on one side of the cell, and ultrapure water was injected on one side so that no bubbles would enter. A stir bar was placed in each cell, a lid was attached, and the mixture was placed on a stirring hot plate set at 30 ° C., and stirring was started. The solution on the ultrapure water side was collected in a 1 mL screw tube with a syringe every 1 hour until 5 hours, and 1 mL of ultrapure water was added to the cell on the ultrapure water side. The solution collected every 1 hour was diluted 100 times with ultrapure, and the concentration was measured by ion chromatography. The fuel permeability was obtained by taking the slope (g / h) from the change over time in the calculated concentration and dividing the area by the film thickness. A lower fuel permeability is preferable because fuel cutoff performance is higher.

(Hydrazine resistance)
The durability against an aqueous hydrazine solution, which is a kind of fuel for alkaline fuel cells, was evaluated by the following method. A film sample (film thickness of about 50 μm) cut out to about 1 cm × 4 cm was put in a pressure-resistant glass container, sealed by adding 30 ml of a 10 wt% hydrazine aqueous solution, and immersed at 80 ° C. for 24 hours. The evaluation was ○ when the film shape as a film after the durability test was maintained, and × when the film shape was not maintained and recovery was difficult.

The evaluation results of the membranes of Examples 5 to 8 are shown in Table 2, and the relationship between the ionic conductivity and fuel permeability of Examples and Comparative Examples is shown in FIG.

From Table 2, it can be seen that the membranes of the examples of the present invention have excellent ionic conductivity with respect to known anion exchange resins. Further, FIG. 6 shows that this characteristic is in a trade-off relationship from the relationship between the ionic conductivity of these membranes and the fuel permeability.

On the other hand, regarding the hydrazine resistance, it can be seen that the membrane of the example is superior to the membrane of the comparative example even if it has a high ion exchange capacity. From the above, it was found that the anion exchange resin of the present invention has high ionic conductivity and fuel barrier properties, and is excellent in durability, and is excellent as a material for alkaline fuel cells.

(Evaluation of alkaline fuel cell using the anion exchange resin membrane of the present invention)
Using the anion exchange resin membrane of Example 5, Angew. Chem. Int. Ed. A power generation test was conducted with reference to 2007, 46, 8024-8027. The structure of the catalyst layer was set to sampleC in the document table 2, the power generation conditions were the supporting information and FIG. S1 of the document, and the cell temperature was set to 80 ° C. The results are shown in FIG. The MEA using the anion exchange resin membrane of the present invention has a power density of about 160 mW / cm ² and a high value as an alkaline fuel cell.

Claims (10)

1. A) The main chain contains a repeating unit containing an aromatic group and an ether group,
   B) The repeating unit is an anion exchange resin having a side chain into which an aromatic group and an anion exchange group are introduced.
2. The anion exchange resin according to claim 1, wherein the anion exchange resin is a block copolymer comprising a hydrophilic part block containing an anion exchange group and a hydrophobic part block substantially not containing an anion exchange group.
3. The anion exchange resin according to claim 2, wherein the hydrophobic part block is composed of a repeating unit containing an aromatic group in the main chain.
4. The anion exchange resin according to any one of claims 1 to 3, wherein the number of anion exchange groups introduced into the repeating unit is 0.7 or more per repeating unit.
5. The anion exchange resin according to any one of claims 1 to 4, wherein the anion exchange group is a quaternary ammonium salt.
6. The side chain into which the aromatic group and the anion exchange group are introduced is represented by the following formula (1):
   

   

   (In the formula, X is an anion exchange group, m and n are each an integer of 0 or more, and m + n ≧ 1, and one or more X is introduced per fluorenyl structure to form a fluorenyl structure. Or may be introduced into any one of the aromatic rings.)
   The anion exchange resin according to any one of claims 1 to 5, comprising a fluorenyl structure.
7. The ion exchange capacity is 0.7 meq. The anion exchange resin according to any one of claims 1 to 6, which is at least / g.
8. A polymer electrolyte membrane comprising the anion exchange resin according to any one of claims 1 to 7.
9. A fuel cell catalyst layer comprising the anion exchange resin according to any one of claims 1 to 7.
10. A fuel cell comprising the polymer electrolyte membrane according to claim 8 and / or the catalyst layer for a fuel cell according to claim 9.
    

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