JP2009249337A - Perfluorophenylene derivative, method for producing the same and membrane electrode assembly - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a perfluoro electrolyte that exhibits a low EW and is acid-resistant, and is useful for producing a proton-conducting membrane and a membrane electrode assembly. <P>SOLUTION: The perfluorophenylene derivative contains a phosphonic acid group containing a phosphonic acid ester group and/or a sulfonic acid group containing a sulfonyl halide group bonded thereto, preferably a perfluorophenylene derivative is represented by chemical formula (1): C<SB>6</SB>F<SB>5-r</SB>X<SB>r</SB>-(C<SB>6</SB>F<SB>4-s</SB>X<SB>s</SB>)<SB>t</SB>-C<SB>6</SB>F<SB>5-u</SB>X<SB>u</SB>(wherein X is a phosphonic acid group and/or a sulfonic acid group; t is an integer of 0-8; r and u are each an integer of 0-5 and not zero at the same time; and s is an integer of 0-4). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a perfluorophenylene derivative used for producing a proton conducting membrane or a membrane electrode assembly for a polymer electrolyte fuel cell.

Conventionally, a perfluorosulfonic acid membrane represented by the following chemical formula (3) has been used as a polymer electrolyte that governs the performance of a solid polymer fuel cell. Its feature is that it has much better oxidation resistance than a hydrocarbon film because of the perfluoro structure that does not contain CH bonds.

This membrane is produced by hydrolyzing a perfluoro copolymer membrane represented by the following chemical formula (4).

The above perfluoro copolymer film is obtained by copolymerizing tetrafluoroethylene and a long side chain perfluorovinyl ether monomer having two ether bonds represented by the following chemical formula (5), and melt-molding the obtained polymer. Manufactured.

  Since the perfluorosulfonic acid membrane represented by the above chemical formula (3) has a long side chain to which a sulfonic acid group is bonded, the ratio p / q of the number of repeating units is set to 4. in order to maintain sufficient mechanical strength. It must be 6 or more. Therefore, it is 1.1 (meq / gram dry resin) or less in terms of ion exchange capacity (IEC) and 900 or more in terms of EW (Equivalent Weight), which is not sufficient in terms of proton conductivity and fuel. When the battery operating temperature is 80 ° C. or higher, the membrane is dried and cannot be used.

例えば、ＥＷ＝１０００のポリマーとＥＷ＝２００のポリマーを８：２の重量比で混合した時のＥＷは、ＥＷ＝１／（０．８／１０００＋０．２／２００）＝５５６となる。 Here, the EW and the ion exchange capacity can be mutually converted by a relational expression of EW = 1000 / IEC, and EW is calculated by (molecular weight of electrolyte) / (number of equivalents of ion exchange group × valence). From this definition, the EW value when two kinds of electrolytes are mixed is calculated by the following equation.

For example, EW when a polymer having EW = 1000 and a polymer having EW = 200 is mixed at a weight ratio of 8: 2 is EW = 1 / (0.8 / 1000 + 0.2 / 200) = 556.

In order to solve the problem that EW cannot be lower than 900 in the perfluorosulfonic acid membrane represented by the chemical formula (3), a short side chain type having one ether bond represented by the following chemical formula (6) There are known attempts to increase the energy efficiency by copolymerizing perfluorovinyl ether monomer with tetrafluoroethylene to increase the ion exchange capacity and lower the internal electrical resistance of the polymer electrolyte fuel cell (for example, patent documents). 1).

However, the monomer represented by the chemical formula (6) undergoes chain transfer due to the cyclization reaction represented by the following reaction formula during copolymerization with tetrafluoroethylene (for example, see Non-Patent Document 1).

As a result, the molecular weight of the obtained copolymer is not sufficient, the mechanical strength of the perfluorosulfonic acid membrane is lowered, and it becomes difficult to maintain the assembly and performance of the fuel cell for a long time.
Such a phenomenon is more likely to occur as the ratio of the perfluorovinyl ether monomer to the tetrafluoroethylene increases. Therefore, the membrane using the monomer of the chemical formula (6) increases the ion exchange capacity while maintaining the mechanical strength. It is difficult.

In order to solve the above cyclization problem, a short side chain type perfluorovinyl ether monomer represented by the following chemical formula (7) is known (for example, see Patent Document 2 relating to the invention of the present inventors).

  However, a specific manufacturing method is disclosed only when n = 3, and the disclosed manufacturing process is complicated and cannot be implemented industrially. Furthermore, since the cyclization reaction in the monomer synthesis step occurs about 50% (see, for example, Non-Patent Document 1), it is considered that the effect of suppressing the cyclization reaction during the polymerization is not sufficient.

Attempts have been made to overcome the limitations of the improved method using sulfonic acid groups as described above by copolymerizing a perfluorovinyl ether monomer having a phosphonic acid group with tetrafluoroethylene (for example, the inventors of the present application). (See Patent Document 3).
The phosphonic acid group is divalent, and according to the definition of EW, it is advantageous because EW can be halved when a monovalent sulfonic acid group is used. However, there are many methods for synthesizing the disclosed monomers. It takes a step and is not practical.

  The present inventor conducted intensive studies to obtain a perfluoro proton conductive membrane having an EW of 900 or less, a high mechanical strength, and an excellent oxidation resistance. As a result, commercially available perfluorobenzene or decafluorobiphenyl, or perfluorophenylene derivatives described in Non-Patent Documents 2, 3, and 4, a perfluorophenylene derivative in which a phosphonic acid group or a sulfonic acid group is bonded, It was found that the EW functions as a perfluoroelectrolyte having an oxidation resistance of 900 or less, and the present invention was completed.

  By mixing the perfluorophenylene derivative with the perfluorosulfonic acid resin represented by the above chemical formula (3), it is possible to obtain a perfluoro proton conductive membrane having an EW of 900 or less. Moreover, it is also possible to reduce the electrical resistance of the membrane electrode assembly (MEA) by containing it in the electrode catalyst layer in which the same perfluorosulfonic acid resin as the membrane is used for proton transfer.

Since the perfluorophenylene derivative of the present invention is generally water-soluble, when it is contained in a proton conductive membrane or an electrode catalyst layer, it is preferably crosslinked and insolubilized so that it does not flow out with generated water.
For this purpose, cross-linking of phosphonic acid groups with polyvalent metal ions (see Patent Document 4 relating to the invention of the present inventor) and sulfonimide group cross-linking of sulfonic acid groups (see Patent Document 5) can be used effectively.
In the present invention, any polyvalent metal ion can be used as long as it can crosslink with a phosphonic acid group. For example, calcium ion, platinum ion, cerium ion, manganese ion and the like are preferable.

As an organic EL electron transfer material, a perfluorophenylene derivative to which a functional group is bonded is known (for example, see Patent Document 6). However, the types of functional groups described are trifluoromethyl groups, nitro groups, and nitrile groups, which are completely different from the phosphonic acid groups and sulfonic acid groups and precursors of the present invention relating to the electrolyte for proton conducting membranes. It is.
In addition, a method of mixing a fullerene derivative to which a sulfonic acid group or a phosphonic acid group is bonded to a perfluorosulfonic acid resin is known (for example, see Patent Document 4 relating to the invention of the present inventor). However, the fullerene derivative has a CH bond and is not perfluoro, and is completely different from the perfluorophenylene derivative of the present invention.

European Patent No. 0289869 U.S. Pat. No. 4,329,435 US Pat. No. 6,680,346 Japanese Patent No. 3984280 JP 2003-303513 A JP 2005-255531 A

Supervised by Kyoji Kimoto, “Development of electrolyte membrane for PEFC”, CM Publishing, 2000, P.A. 33-34 D. D. Callander et al: Tetrahedron, 1966, Vol. 22, 419-432 G. M. Brooke et al: J. Chem. Soc., 729-733 (1964) G. M. Brooke et al: J. Chem. Soc., 1864-1869 (1965)

  An object of the present invention is to provide a low EW and oxidation-resistant perfluoroelectrolyte that enables the production of a perfluoro proton conducting membrane having a lower EW than that of a conventional perfluorosulfonic acid membrane.

The present invention is a perfluorophenylene derivative to which a phosphonic acid group containing a phosphonic acid ester group and / or a sulfonic acid group containing a sulfonyl halide group is bonded, preferably a perfluorophenylene derivative represented by the following chemical formula (1): is there.

非プロトン性極性有機溶媒を用い、ＬｉＰＯ（ＯＲ）_２（ＲはＣ_１〜Ｃ_５のアルキル基又はフェニル基）又はＫ_２ＳＯ_３と常圧又は加圧下、５０〜３００℃で反応させ、必要により加水分解を行うことを特徴とする上記のパーフロロフェニレン誘導体の製造方法も本発明である。 In addition, a perfluorophenylene compound represented by the following chemical formula (2)

Using an aprotic polar organic solvent, LiPO (OR) ₂ (R is a C _{1 to} C ₅ alkyl group or phenyl group) or K ₂ SO ₃ is reacted at 50 to 300 ° C. under normal pressure or pressure, and necessary. The above-mentioned method for producing a perfluorophenylene derivative, which is characterized in that hydrolysis is performed by the method of the present invention.

In addition, the above-mentioned perfluorophenylene derivative in which the phosphonic acid group forms an ionic bridge with the polyvalent metal ion or the sulfonic acid group forms a sulfonimide group bridge is also the present invention.
Further, a membrane / electrode assembly in which the perfluorophenylene derivative or the perfluorophenylene derivative crosslinked with the polyvalent metal ion bridge or the sulfonimide group bridge is contained in a membrane and / or an electrode catalyst layer is also provided. It is an invention. In this case, the membrane is preferably made of perfluorosulfonic acid resin, and preferably has a reinforcing material.

  By using the low EW and oxidation-resistant perfluoroelectrolyte disclosed in the present invention, the proton conductivity is higher than that of the perfluorosulfonic acid membrane represented by the chemical formula (3), and the operating temperature of the fuel cell is 80 ° C. Even with the above, it becomes possible to produce an oxidation-resistant perfluoroproton conductive membrane that can be used without drying the membrane.

The present invention is a perfluorophenylene derivative to which a phosphonic acid group containing a phosphonic acid ester group and / or a sulfonic acid group containing a sulfonyl halide group is bonded, preferably a perfluorophenylene derivative represented by the following chemical formula (1): However, some F atoms may be substituted with Br or Cl.

The perfluorophenylene derivative of the present invention may be a mixture of different t values, or may be substantially a single product after purification. The range of t is usually 0 to 8, but is preferably in the range of 2 to 5 for ease of production.
The types of X bonded to the perfluorophenylene nucleus are independent inside each other, and may be the same or different. Accordingly, all Xs may be phosphonic acid groups or sulfonic acid groups, or phosphonic acid groups and sulfonic acid groups may be mixed.

  In the above chemical formula (1), the type of X and the number of bonds bonded to t perfluorophenylene nuclei existing in the intermediate part may be the same or different in each phenylene nuclei. The above-mentioned bonds between the perfluorophenylene nuclei are usually linearly bonded at the para position, but may be partially bent and bonded at the meta position.

The functional group contained in the perfluorophenylene derivative of the present invention is hydrolyzed or ion-exchanged by a method known to those skilled in the art, if necessary, and finally the phosphonic acid group PO (OH) ₂ or the sulfonic acid group SO ₃ H. It functions as a perfluoroelectrolyte with excellent oxidation resistance.
Table 1 shows an example of the EW of the perfluorophenylene derivative of the present invention in the case of a phosphonic acid group (PO (OH) ₂ MW = 81 valence = 2).

Table 2 shows an example of the EW of the perfluorophenylene derivative of the present invention in the case of a sulfonic acid group (SO ₃ H MW = 81 valence = 1).

The perfluorophenylene derivative of the present invention to which a phosphonic acid group PO (OH) ₂ and / or a sulfonic acid group SO ₃ H as a perfluoroelectrolyte is bonded is generally water-soluble. However, when it is contained in the proton conductive membrane or the electrode catalyst layer, it must be water-insoluble so as not to dissolve in water generated during the operation of the fuel cell and flow out, and the following three methods (A ) To (C) is preferably performed.

(A) Selection of EW The perfluoroelectrolyte comprising the perfluorophenylene derivative of the present invention cannot be generally described, but if the EW is 200 or more, it is often water-insoluble. For _{example, C 6 F 5 -C 6 F} 4 -SO 3 H (EW = 396) are non-water soluble.
In contrast, C ₆ F ₅ -C ₆ F ₄ -PO (OH) ₂ (EW = 198) is slightly water-soluble, but it becomes water-insoluble when the number of phenylene nuclei is increased to increase EW. .

The obtained water-insoluble perfluoroelectrolyte was dissolved in a polar organic solvent such as tetrahydrofuran, dioxane, dimethylformamide, dimethylacetamide and the like, and a (lower alcohol + water) solution of perfluorosulfonic acid resin represented by the above chemical formula (3) (Example: EW = 1100 manufactured by Aldrich Co.) and mixed with a reinforcing material such as a glass fiber nonwoven fabric or a stretched porous polytetrafluoroethylene membrane, and can be formed on the proton conducting membrane.
Since the proton conductive membrane is mixed with a perfluoroelectrolyte having a lower EW than that of the perfluorosulfonic acid resin that is a matrix polymer, the EW can be made 900 or less.

(B) Polyvalent metal ion cross-linking of phosphonic acid group When using a water-soluble perfluoroelectrolyte composed of the perfluorophenylene derivative of the present invention, calcium ion, platinum ion, cerium ion, manganese ion, etc. A valent metal ion can be added to the aqueous solution of the electrolyte to form a metal ion bridge and insolubilize in water. In this case, the electrolyte preferably has two or more phosphonic acid groups that cause stable metal ion crosslinking. The metal salt to be added is appropriately selected from water-soluble salts such as chlorides, nitrates, sulfates and acetates.
The obtained insoluble metal ion crosslinked perfluoroelectrolyte was added to a (lower alcohol + water) solution of the perfluorosulfonic acid resin represented by the above chemical formula (3) (for example, EW = 1100 manufactured by Aldrich) and homogenizer. It is possible to form a film on the proton conducting membrane by stirring and applying and impregnating a reinforcing material such as a glass fiber nonwoven fabric or a stretched porous polytetrafluoroethylene membrane.

In this case, the operation order is changed, and first, a water-soluble perfluoroelectrolyte having two or more phosphonic acid groups is converted into a perfluorosulfonic acid resin (lower alcohol + water) solution (eg, EW = 1100 manufactured by Aldrich). Add, add water-soluble salt of polyvalent metal ions, stir with a homogenizer, form metal ion cross-links of phosphonic acid groups, and impregnate into reinforcing materials such as glass fiber nonwoven fabric and stretched porous polytetrafluoroethylene membrane It is also possible to form a film.
The proton conducting membrane obtained by any of the above methods is mixed with a perfluoroelectrolyte having a lower EW than that of the perfluorosulfonic acid resin that is a matrix polymer, so that the EW can be made 900 or less.

(C) Sulfonimide group crosslinking of sulfonic acid group The sulfonic acid group of the perfluorophenylene derivative of the present invention is converted into a sulfonyl fluoride group and a sulfonamide group by the following reaction known to those skilled in the art, and both are trialkylated. It is possible to perform sulfonimide group crosslinking by reacting in an amine.

The perfluorophenylene derivative crosslinked with the sulfonimide group by the above method is mixed with a (lower alcohol + water) solution of the perfluorosulfonic acid resin represented by the chemical formula (3) (for example, EW = 1100 manufactured by Aldrich). Then, a proton conductive membrane can be formed by coating and impregnating a reinforcing material such as a glass fiber nonwoven fabric or a stretched porous polytetrafluoroethylene membrane.
The proton conducting membrane thus obtained is mixed with a perfluoroelectrolyte having a lower EW than that of the perfluorosulfonic acid resin which is a matrix polymer, so that the EW can be made 900 or less.

  In the above crosslinking method, when only the phosphonic acid group is bonded to the perfluorophenylene derivative, crosslinking with a polyvalent metal ion is performed, and when only the sulfonic acid group is bonded, crosslinking with a sulfonimide group is performed. Although it is applied, in the case where a phosphonic acid group and a sulfonic acid group coexist, both crosslinking methods are applicable.

The perfluoroelectrolyte comprising the perfluorophenylene derivative of the present invention insolubilized in water by the methods (A) to (C) described above is a (lower alcohol + water) solution of perfluorosulfonic acid resin (for example, EW = manufactured by Aldrich) 1100) is added to the catalyst ink and applied to the surface of the membrane, whereby the electrolyte can be contained in the electrode catalyst layer of the anode and / or cathode of the membrane electrode assembly.
In this case, the operation order is changed, and first, a catalyst ink containing a perfluoroelectrolyte composed of a water-soluble perfluorophenylene derivative containing a perfluorosulfonic acid resin (lower alcohol + water) solution (eg, EW = 1100 manufactured by Aldrich). It is also possible to add a water-soluble salt of a polyvalent metal ion to form a metal ion bridge of a phosphonic acid group.
The perfluoroelectrolyte of the present invention can be contained in the anode and / or cathode electrode catalyst layer of the membrane electrode assembly by applying the catalyst ink thus obtained to the surface of the membrane.

テトラヒドロフラン，ジオキサン，ジメチルホルムアミド，ジメチルアセトアミド，スルホラン等の非プロトン性極性有機溶媒を用い、ＬｉＰＯ（ＯＲ）_２（ＲはＣ_１〜Ｃ_５のアルキル基又はフェニル基）又はＫ_２ＳＯ_３と常圧又は加圧下、５０〜３００℃で反応させ、必要により加水分解やイオン交換することで製造される。
反応温度は、使用する有機溶媒の沸点、必要とする反応速度及び副反応の抑制を考慮して適宜選択される。 The perfluorophenylene derivative of the present invention includes commercially available perfluorobenzene C ₆ F ₆ and decafluorobiphenyl C ₆ F ₅ -C ₆ F ₅ , or the following described in Non-Patent Documents 2, 3, and 4 above A perfluorophenylene compound represented by the chemical formula (2)

Using an aprotic polar organic solvent such as tetrahydrofuran, dioxane, dimethylformamide, dimethylacetamide or sulfolane, LiPO (OR) ₂ (R is a C _{1 to} C ₅ alkyl group or phenyl group) or K ₂ SO ₃ and normal pressure Alternatively, it is produced by reacting at 50 to 300 ° C. under pressure and, if necessary, hydrolysis or ion exchange.
The reaction temperature is appropriately selected in consideration of the boiling point of the organic solvent to be used, the required reaction rate, and suppression of side reactions.

The perfluorophenylene compound oligomer represented by the chemical formula (2) is produced by the following method described in Non-Patent Documents 2, 3, and 4.

The reaction solvent is preferably tetrahydrofuran, and the reaction temperature is usually from -40 to 60 ° C. According to Non-Patent Document 2, an infrared absorption spectrum of the above perfluoro phenylene compound ^{oligomers, 1475cm -1, 970cm -1,} with characteristic peaks around 710 cm ^-1.

この場合、反応性及び取り扱いの容易さから、Ｍｅはリチウムであることが好ましい。 In the present invention, phosphonic acid groups, sulfonic acid groups, or precursors thereof are introduced using the following reagents.
-Phosphonic acid group introduction reagent (alkali metal salt of dialkyl or diphenyl phosphite)
As shown below, dialkyl or diphenyl phosphite is an alkali metal salt obtained by reacting dialkyl or diphenyl phosphite with an alkali metal hydride in tetrahydrofuran, dioxane, dimethylformamide, dimethylacetamide, sulfolane, as it is, perfluorobenzene, decafluorobiphenyl, Used in nucleophilic substitution reaction with the above perfluorophenylene compounds.

In this case, Me is preferably lithium in terms of reactivity and ease of handling.

After the reaction, the phosphonic acid ester group is hydrolyzed and converted to a phosphonic acid group by the following known method.

・ Reagent for introducing sulfonic acid group (alkali metal salt of sulfurous acid Me ₂ SO ₃ )
In the nucleophilic substitution reaction of an alkali metal salt of sulfurous acid Me ₂ SO ₃ (Me is an alkali metal) with perfluorobenzene, decafluorobiphenyl, and the above perfluorophenylene compound, K ₂ SO is used from the viewpoint of solubility and reactivity. ₃ is preferred, but Na ₂ SO ₃ can also be used.
After the reaction, the sulfonate SO ₃ Me is converted to acid type SO ₃ H with hydrochloric acid.

The sulfonic acid group (SO ₃ H or SO ₃ K) thus obtained is converted into a sulfonyl chloride group SO ₂ Cl with PCl ₅ and then converted into a sulfonyl fluoride group SO ₂ F with KF, and then reacted with ammonia to form a sulfonamide group. Conversion to SO ₂ NH ₂ is possible.
Furthermore, it is possible to react a sulfonyl fluoride group and a sulfonamide group in a trialkylamine at room temperature to 100 ° C. to form a sulfonimide group bridge.

  Examples are shown below, but the present invention is not limited thereto.

Put dimethylformamide 100ml glass four-necked flask 200 ml, the solution was dispersed by adding decafluoro biphenyl 6.68 g (0.02 mol) in a stream of _{nitrogen, K 2 SO 3 4.74g (0} . 03 mol) was added with stirring, and 10 g of water was further added. The reaction was carried out at 120 ° C. for 24 hours using an oil bath, and water was added to precipitate formed by filtration.
It was measured infrared absorption ^{spectrum, 1452~1468cm -1, 962cm -1,} characteristic absorption of biphenyl groups 658cm ^-1, asymmetric vibrations of the SO ₂ in 1230~1246cm ^-1, symmetric vibration of SO ₂ to 1067cm ^-1 (See FIG. 1), it was found that the sulfonate group SO ₃ K was bound to the biphenyl nucleus.
The S analysis by ICP-AES (Inductively Coupled Plasma Atomic Emission Spectroscopy) was 8.4%, and the calculated value as C ₆ F ₅ -C ₆ F ₄ -SO ₃ K was 7.4%. Almost matched. The reason why the analytical value was slightly larger than the calculated value was presumed to be that KO ₃ S—C ₆ F ₄ —C ₆ F ₄ —SO ₃ K was by-produced.

The above perfluorosulfonate was changed to C ₆ F ₅ -C ₆ F ₄ —SO ₃ H (EW = 396, water-insoluble) with hydrochloric acid and dissolved in 2 ml of tetrahydrofuran. This solution is added to a 5% Nafion solution (manufactured by Aldrich, EW = 1100) in a 50 ml glass container, so that C ₆ F ₅ -C ₆ F ₄ -SO ₃ H is 20% based on the Nafion polymer. And stirred for 30 minutes with a homogenizer.
The obtained dispersion was applied onto a glass fiber nonwoven fabric (manufactured by Japan Vilene Co., Ltd.) having a thickness of 100 microns using a brush, and the gap was impregnated. This operation was repeated 10 times and then dried at 100 ° C. to obtain a perfluorosulfonic acid film containing a translucent sulfonated perfluorophenylene derivative.
The polymer impregnation rate of the membrane was about 85%, and the EW of the polymer part was EW = 1 / (0.8 / 1100 + 0.2 / 396) = 812 from the mixing ratio.

A 300 ml four-necked flask was charged with 3.8 g (0.15 mol) of magnesium pieces, 0.04 g (0.0002 mol) of dibromoethane and 100 ml of tetrahydrofuran in a nitrogen stream, while maintaining the temperature at 0 to 4 ° C. 39.1 g (0.16 mol) of bromobenzene was added with slow stirring.
A solution obtained by dispersing 5.01 g (0.15 mol) of decafluorobiphenyl in 50 ml of tetrahydrofuran was added to the produced Grignard reagent while stirring. Furthermore, after making it react at 0-4 degreeC for 6 hours, after leaving still at room temperature overnight, 10% sulfuric acid was thrown into the reaction liquid, and the unreacted magnet piece was dissolved. The precipitate was filtered off and washed with methanol.
As a result of analysis by electrolytic desorption mass spectrometry after drying, a perfluorophenylene compound oligomer (average molecular weight 926) containing C ₆ F _5- (C ₆ F ₄ ) ₄ -C ₆ F ₅ as a main component is generated. It has been found. With KBr, it was measured infrared absorption spectrum of the ^{substance, 1474cm -1, 968cm -1,} a characteristic peak around 708cm ^-1 appeared, consistent with the above figures Non-Patent Document 2.

A 200 ml glass four-necked flask was charged with 100 ml of dimethylformamide, and 4.65 g (0.034 mol) of diethyl phosphite was dissolved in a nitrogen stream. To this solution, 0.28 g (0.035 mol) of lithium hydride was added with stirring to obtain LiPO (OC ₂ H ₅ ) ₂ . To this solution, 10 g of the above oligomer was added with stirring. After reacting at 90 ° C. for 20 hours and the solution became transparent, water was added and the resulting precipitate was filtered off.
Was measured infrared absorption ^{spectra, 1464cm -1, 964cm -1,} characteristic absorption of perfluoro-phenylene group in 721cm ^-1, ethyl group near 2991cm ^-1, the absorption of P = O in the vicinity of 1252～1273Cm ^-1 It was seen that the phosphonate ester group PO (OC ₂ H ₅ ) ₂ was bonded to the perfluorophenylene nucleus.

20 g of trimethylsilyl bromide was added to 2 g of this powder and reacted at 40 to 50 ° C. for 16 hours to perform transesterification. Water was added thereto for hydrolysis, followed by drying under reduced pressure. When the infrared absorption spectrum of the obtained powder was measured, the absorption of the ethyl group disappeared and a large OH absorption appeared in the vicinity of 3400 cm ⁻¹ . When P of this phosphonated perfluorophenylene derivative was analyzed by ICP-AES, about two phosphonic acid groups were bonded, and when the average EW was calculated, a result of EW = 272 was obtained. Met.
The above phosphonated perfluorophenylene derivative was dissolved in tetrahydrofuran and operated in the same manner as in Example 1 to obtain a perfluorosulfonic acid film containing a phosphonic acid group. Since the mixing ratio of the phosphonated perfluorophenylene derivative with respect to the Nafion polymer was 15%, the average EW of the polymer portion was EW = 1 / (0.85 / 1100 + 0.15 / 272) = 755.

100 ml of dimethylacetamide was placed in a 200 ml four-necked flask, and 6.90 g (0.05 mol) of diethyl phosphite was dissolved in a nitrogen stream. To this solution, 0.41 g (0.051 mol) of lithium hydride was added with stirring and heated to about 50 ° C. to obtain LiPO (OC ₂ H ₅ ) ₂ . To this solution, 4 g of the oligomer obtained in Example 2 was added with stirring, and the mixture was further reacted at 90 ° C. for 20 hours, and water was added to precipitate formed.
It was measured infrared absorption ^{spectra, 1474cm -1, 964cm -1,} characteristic absorption of perfluoro-phenylene group in 708cm ^-1, ethyl group near 2984cm ^-1, the absorption of P = O in the vicinity of 1211cm ^-1 observed (See FIG. 2), it was found that the phosphonate ester group PO (OC ₂ H ₅ ) ₂ was bonded to the perfluorophenylene nucleus.

20 g of trimethylsilyl bromide was added to 2 g of this powder and reacted at 40 to 50 ° C. for 32 hours to perform transesterification. Water was added thereto for hydrolysis, followed by drying under reduced pressure. When the infrared absorption spectrum of the obtained powder was measured, the absorption of the ethyl group disappeared, and a large OH absorption appeared in the vicinity of 3400 cm ⁻¹ , and 1472 cm ^{− 1, 968cm} -1, characteristic absorption of perfluoro-phenylene group in 708cm ^-1, the absorption of P = O in 1234Cm ^-1 appeared (see FIG. 3). When P of this phosphonated perfluorophenylene derivative was analyzed by ICP-AES, 4 to 5 phosphonic acid groups were bonded, and when the average EW was calculated, a result of EW = 130 was obtained. Met.

A solution of 500 mg of the above phosphonated perfluorophenylene derivative dissolved in 20 ml of water was placed in a 50 ml beaker, and a solution of 100 mg of cerium chloride heptahydrate CeCl ₃ 7H ₂ O dissolved in 10 ml of water was added thereto and stirred. The resulting precipitate was filtered and dried to obtain a phosphonated perfluorophenylene derivative crosslinked with Ce ions.
This is ground in a mortar and added to a 5% Nafion solution (Aldrich, EW = 1100) in a 50 ml glass container so that the phenylene derivative is 10% with respect to the Nafion polymer. Stir for 30 minutes. The obtained dispersion was applied onto a glass fiber nonwoven fabric (manufactured by Japan Vilene Co., Ltd.) having a thickness of 100 microns using a brush, and the gap was impregnated. This operation was repeated 10 times, and then dried at 100 ° C. to obtain a perfluorosulfonic acid membrane containing a Ce ion crosslinked phosphonated perfluorophenylene derivative.

In Example 3, a 3% aqueous solution of a phosphonated perfluorophenylene derivative was placed in a 50 ml glass container so that the phenylene derivative was 10% with respect to the Nafion polymer. = 1100) and stirred with a homogenizer for 30 minutes. To this solution, a 1% aqueous solution of cerium chloride heptahydrate CeCl ₃ 7H ₂ O was added with stirring to crosslink the phosphonic acid with Ce ions.
The obtained dispersion was applied onto a glass fiber nonwoven fabric (manufactured by Japan Vilene Co., Ltd.) having a thickness of 100 microns using a brush, and the gap was impregnated. This operation was repeated 10 times, and then dried at 100 ° C. to obtain a perfluorosulfonic acid membrane containing a Ce ion crosslinked phosphonated perfluorophenylene derivative. Since the mixing ratio of the phosphonated perfluorophenylene derivative with respect to the Nafion polymer was 10%, the EW of the polymer portion was EW = 1 / (0.90 / 1100 + 0.10 / 130) = 629.

In Example 2, using decafluoro biphenyl in place of perfluoro phenylene compound oligomers, LiPO _{(OC 2} H _{5) 2} in molar ratio 1: using the same method except that the _1, C 6 _{F 5} - to obtain a _{C 6 F 4 -PO (OH)} 2. The EW of the phosphonated phenylene derivative was 198 and was slightly water-soluble.

In Example 1, the perfluorophenylene compound oligomer obtained in Example 2 was used instead of decafluorobiphenyl, and the same operation was carried out except that the charged molar ratio of K ₂ SO ₃ was 3 times that of the raw material. A sulfonated perfluorophenylene derivative having about 3 ₃ K bonded thereto was obtained.

(Example 1) It is a figure which shows the measurement result of an infrared absorption spectrum. (Example 3) It is a figure which shows the measurement result of an infrared absorption spectrum. (Example 3) It is a figure which shows the measurement result of an infrared absorption spectrum.

Claims (7)

  A perfluorophenylene derivative having a phosphonic acid group containing a phosphonic acid ester group and / or a sulfonic acid group containing a sulfonyl halide group bonded thereto. The perfluorophenylene derivative according to claim 1, which is represented by the following chemical formula (1).

A perfluorophenylene compound represented by the following chemical formula (2)

Using an aprotic polar organic solvent, LiPO (OR) ₂ (R is a C _{1 to} C ₅ alkyl group or phenyl group) or K ₂ SO ₃ is reacted at 50 to 300 ° C. under normal pressure or pressure, and necessary. The method for producing a perfluorophenylene derivative according to claim 1, wherein the hydrolysis is performed by the method.   The perfluorophenylene derivative according to claim 1 or 2, wherein the phosphonic acid group forms an ionic crosslink with the polyvalent metal ion, or the sulfonic acid group forms a sulfonimide group crosslink.   A membrane electrode assembly, wherein the perfluorophenylene derivative according to any one of claims 1, 2, and 4 is contained in a membrane and / or an electrode catalyst layer.   The membrane electrode assembly according to claim 5, wherein the membrane is made of perfluorosulfonic acid resin.   The membrane electrode assembly according to claim 5 or 6, wherein the membrane has a reinforcing material.

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