JP4187692B2 - High temperature durable polymer solid electrolyte membrane - Google Patents

Description

  The present invention relates to a fluorine-based polymer solid electrolyte membrane useful as a fuel cell membrane.

In recent years, fuel cells using solid polymer electrolyte membranes as electrolytes have attracted attention because they can be reduced in size and weight, and high power density can be obtained even at relatively low temperatures, and development for automotive applications in particular has been accelerated. ing.
The polymer solid electrolyte membrane material used for such purposes is required to have excellent proton conductivity, appropriate water retention, gas barrier properties against hydrogen gas, oxygen gas, and the like. As materials satisfying such requirements, various polymers having a sulfonic acid group or a phosphonic acid group at the main chain or at the end of the side chain have been studied. For example, as described in Non-Patent Document 1, many materials are available. Has been proposed.
However, under actual fuel cell operating conditions, active oxygen species with high oxidizing power are generated at the electrode, and in order to operate the fuel cell stably over a long period of time, it is necessary to operate under such a harsh oxidizing atmosphere. Durability is required. Many of the hydrocarbon-based materials that have been proposed so far often exhibit excellent characteristics with respect to the initial characteristics of the fuel cell operation, but do not exhibit sufficient resistance for long-term operation.

（式中、ｍは０〜３、ｎは１〜５、ｋ、ｌは１以上の整数で、１．５≦ｋ／ｌ≦１４）
で表されるパーフルオロカーボンスルホン酸ポリマーが主に採用されている。
これらのパーフルオロカーボンスルホン酸ポリマー膜は、骨格が全フッ素化されているために化学的に極めて高い耐久性を示し、先述の炭化水素系膜に比べ、より過酷な運転条件でも使用することが可能である。 For this reason, the following general formula (1):

(In the formula, m is 0 to 3, n is 1 to 5, k and l are integers of 1 or more, and 1.5 ≦ k / l ≦ 14)
The perfluorocarbon sulfonic acid polymer represented by the following is mainly employed.
These perfluorocarbon sulfonic acid polymer membranes exhibit extremely high chemical durability due to the fully fluorinated skeleton, and can be used even in harsh operating conditions compared to the hydrocarbon membranes described above. It is.

However, it is well known that these perfluorocarbon sulfonic acid polymers have a glass transition point close to the actual use temperature range. As a result, the perfluorocarbon sulfonic acid polymer has sufficient physical strength when operated at room temperature, but the temperature range of 90 ° C. or higher. Then, physical strength is insufficient. Actually, there are Nafion (DuPont product name), Aciplex (Asahi Kasei product name), and Flemion (Asahi Glass product name) as perfluorocarbon sulfonic acid polymer membranes often used for research, but these membranes are sufficient. When trying to operate in a humidified environment at a temperature exceeding 90 ° C, stable power generation was not possible. In order to solve this problem, a crosslinked film in which a part of the sulfonic acid group of the perfluorocarbon sulfonic acid polymer is imide-crosslinked has been developed (for example, Patent Document 1), but the crosslinked structure is formed by a covalent bond. When the degree of cross-linking is high, it tends to be very brittle and it cannot be said that it is preferable.
Further, a membrane reinforced with a PTFE porous membrane or the like (for example, Patent Documents 2 and 3) has been developed and exhibits higher mechanical strength than an unreinforced membrane, but it is also continuously at a high temperature of 90 ° C. or higher. I couldn't stand driving.

Special table 2001-522401 JP-A-8-162132 Japanese Patent Publication No. 63-61337 O. Savadogo, Journal of New Materials for Electrochemical Systems I, 47-66 (1998)

  The present invention provides a solid polymer electrolyte membrane for a fuel cell that can be stably operated even at a high temperature of 90 ° C. or higher.

As a result of diligent studies to solve the above-mentioned problems, the inventor has a membrane mainly composed of a perfluorocarbon sulfonic acid polymer, an aliphatic hydrocarbon or an aromatic hydrocarbon as a basic skeleton, and a main chain or a side chain portion. When a polymer solid electrolyte membrane characterized by containing an additive having two or more amino groups is used, ionic cross-linking is formed, and the cross-linking does not give the membrane more than a certain degree of brittleness. It was found that it can be stably used even in a high-temperature region where it could not be used, and the present invention was made.
That is, the present invention is a polymer solid electrolyte membrane comprising a perfluorocarbon sulfonic acid polymer and an additive, wherein the perfluorocarbon sulfonic acid polymer has a weight of 60% or more and 99.9% or less with respect to the polymer solid electrolyte. And the additive is phthalocyanine
It is a polymer solid electrolyte membrane characterized by being.

  By using the solid polymer electrolyte membrane of the present invention, the mechanical properties at high temperatures, which have not been sufficiently resistant with conventional fluorine ion exchange membranes, are improved, and the fuel cell can be operated. .

The polymer solid electrolyte membrane of the present invention will be described in detail below.
The polymer solid electrolyte membrane used in the present invention is an additive having a perfluorocarbon sulfonic acid polymer and an aliphatic hydrocarbon or an aromatic hydrocarbon as a basic skeleton, and having two or more amino groups in the main chain or side chain. It consists of Here, the perfluorocarbon sulfonic acid polymer is specifically represented by the following general formula (1).

（式中、ｍは０〜３、ｎは１〜５、ｋ、ｌは１以上の整数で、１．５≦ｋ／ｌ≦１４）

(In the formula, m is 0 to 3, n is 1 to 5, k and l are integers of 1 or more, and 1.5 ≦ k / l ≦ 14)

  This polymer is usually obtained by subjecting a thermoplastic perfluorocarbonsulfonyl fluoride polymer represented by the following general formula (2) obtained by copolymerizing a perfluorovinyl ether monomer and tetrafluoroethylene (TFE) to a hydrolysis reaction. Obtained by.

（式中、ｍは０〜３、ｎは１〜５、ｋ、ｌは１以上の整数で、１．５≦ｋ／ｌ≦１４）

(In the formula, m is 0 to 3, n is 1 to 5, k and l are integers of 1 or more, and 1.5 ≦ k / l ≦ 14)

Next, the additive used in the polymer solid electrolyte membrane of the present invention has an aliphatic hydrocarbon or aromatic hydrocarbon as a basic skeleton, and has two or more amino groups in the main chain or side chain portion. The two or more amino groups are preferably primary amines, but may be secondary or tertiary, or any combination thereof. The amino group may form part of the ring structure.
Some examples that may be used for such additives are illustrated.
The basic skeleton consists of aliphatic hydrocarbons such as polyallylamine, polyacrylamide, aminopolyacrylamide, polyethyleneimine, polyoxyethylene alkylamine, poly (lysyl-lysyl-valine), poly (2-aminoethyl methacrylate), poly (lysine), polymethacrylamide, poly (oxy [[3- (2-aminoethylamino) propyl] (hydroxy) silanediyl]), poly [oxy [(3-aminopropyl) (hydroxy) silanediyl]],
poly (3-aminomethyl-4-carboxybut-1-ene-1,4-diyl),
poly (trans-3-aminomethyl-4-carboxybut-1-ene-1,4-diyl), poly [1- (carbamoylmethyl) ethylene],
Polymer compounds such as poly (2-acrylamido-2-methylpropane sulphonamide), chitosan, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, 1,4-diaminobutane, 1,2-diaminopropane 1,3-diaminopropane, piperazine, dimethylpiperazine, bis (aminopropyl) piperazine, 2-aminomethylpiperidine, diaminomaleonitrile, guanidine salts and the like.

As the basic skeleton consisting of an aromatic structure, polyaniline, polyamine sulfone, guanamine resin,
poly [iminocarbonyl [4,6-bis (sulfooxy) 1,3-phenylene] carbonylimino (4,4'-diaminobiphenyl-3,3'-diyl)],
poly [[1- (4,6-diamino-1,3,5-triazin-2-yl) piperidine-3,5-diyl] methylene] poly [methylene- (2,6-diamino) -3,5- toluene]
poly [(3-amino-1,4-phenylene) iminocarbonyl (2-carboxy-1,4-phenylene) [bis (trifluoromethyl) methylene] carbonylimino (2-amino-1,4-phenylene)]
poly (oxy-3-amino-1,4-phenylenesulfonyl-2-amino-1,4-phenyleneoxy-1,4-phenylene (dimethylmethylene) -1,4-phenylene),
poly (oxybiphenyl-4,4'-diyloxy-3-amino-1,4-phenylenesulfonyl-2-amino-1,4-phenylene),
poly (oxy-1,4-phenylenesulfonyl-1,4-phenyleneoxy-2-amino-1,4-phenylene (dimethylmethylene) -3-amino-1,4-phenylene),
poly (2,2'-diamino-5-hexadecylbiphenyl-3,3'-diyl),
poly (p-aminophenylacetylene),
poly (oxy-3-amino-1,4-phenylenesulfonyl-1,4-phenyleneoxy-1,4-phenylene (dimethylmethylene) -1,4-phenylene),
poly [(1,3-dioxoisoindoline-2,5-diyl) carbonyl (1,3-dioxoisoindoline-5,2-diyl) -1,3-phenyleneimino (6-amino-1,3,5-triazine-2, 4-diyl) imino-1,3-phenylene],
poly [nitrilo (1-amino-2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9-hexadecafluoro-10-iminodec-10-yl- 1-ylidene)],
poly [nitrilo (1-amino-2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoro-8-iminooct-8-yl-1-ylidene)],
poly [(4-amino-4H-1,2,4-triazole-3,5-diyl) octane-1,8-diyl] poly [(4-amino-4H-1,2,4-triazole-3, 5-diyl) decane-1,10-diyl],
poly [(4-amino-4H-1,2,4-triazole-3,5-diyl) heptane-1,7-diyl], poly [(4-amino-4H-1,2,4-triazole-3 , 5-diyl) hexane-1,6-diyl],
poly [(4-amino-4H-1,2,4-triazole-3,5-diyl) pentane-1,5-diyl],
poly (2-amino-3-methoxy-1,4-phenylene),
poly (2-amino-1,3-phenylene),
poly [(p-aminophenoxy) (phenoxy) phosphazene],
poly [(4-amino-4H-1,2,4-triazole-3,5-diyl) butane-1,4-diyl],
Or the following general formula (3)

（式中、- Ｒは-CH₃N(CH₃)₂ 、-CH₂N(CH₃)₃Cl 、-CH₂N(CH₃)₂(CH₃CH₂OH)Cl 、-CONHCH₂CH₂CH₂N(CH₃)₂ ）

(In the formula, -R is -CH ₃ N (CH ₃ ) ₂ , -CH ₂ N (CH ₃ ) ₃ Cl, -CH ₂ N (CH ₃ ) ₂ (CH ₃ CH ₂ OH) Cl, -CONHCH ₂ CH ₂ CH ₂ N (CH ₃ ) ₂ )

High molecular compounds such as basic anion exchange resins, pyrazine, methylpyrazine, dimethylpyrazine, aminopyridine, N, N'-g-2-naphthyl-p-phenylenediamine, toluylenediamine, phenylenediamine, diaminoanthraquinone, dianisidine, xylidine Range amine, diaminobenzoic acid, diaminotoluene, diaminodiphenyl ether, o-tolidine, benzoguanamine, acetoguanamine, 4,4'-diamino-3,3'-diethyldiphenylmethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 1,8-diazabicycloundecene, 2-aminomethylpiperidine, melamine, benzimidazole and substituted products thereof, imidazole and substituted products thereof, 2-mercaptobenzimidazole and substituted products thereof, phthalose Low molecular compounds such as Nin and the like.
Among the above additives, those having a basic skeleton having an aromatic structure are more preferable because they have continuous heat resistance.
The polymer solid electrolyte of the present invention comprises the above-mentioned perfluorocarbon sulfonic acid polymer and an additive, and the perfluorocarbon sulfonic acid polymer is 60% or more and 99.9% or less, more preferably, with respect to the polymer solid electrolyte. A solid polymer electrolyte membrane characterized by occupying a weight fraction of 70% or more and 99.5% or less.

Here, when the weight fraction of the perfluorocarbon sulfonic acid polymer is less than 60%, the proton conductivity, which is an important performance as an electrolyte membrane, is remarkably lowered, and when it exceeds 99.9%, an additive is added. This is not preferable because the effect of improving mechanical properties such as an increase in glass transition point is insufficient.
The method for producing the solid polymer electrolyte membrane of the present invention is not particularly limited to the production method as long as the perfluorocarbonsulfonic acid polymer and an additive having at least two cation residues in the molecule can be contained. The following is an example of a part of the manufacturing method:

1) Solution 1 in which perfluorocarbon sulfonic acid polymer is dissolved in a mixed solvent of water and hydrocarbon alcohol or fluorine-containing alcohol or an amide solvent such as dimethylformamide or dimethylacetamide as a representative example, and an additive as a solvent After mixing the solution 2 dissolved in the solution and casting it on a support film, etc., the solvent is removed by heating or the like, and if necessary, water washing, pickling, etc. are performed to form a film,
2) By dissolving the perfluorocarbon sulfonic acid polymer and additives in a solvent at the same time, casting the solution on a support film, etc., removing the solvent by heating, etc., and washing with water, pickling, etc. as necessary Film forming method,

3) After the perfluorocarbon sulfonyl fluoride polymer, which is a precursor of the perfluorocarbon sulfonic acid polymer, and the additive are melt-kneaded using an extruder, a plastmill, etc., and formed into a film using a T-die or flat plate press , Saponification, H conversion, a method of forming a film by washing with water,
4) After the perfluorocarbon sulfonyl fluoride polymer, which is a precursor of the perfluorocarbon sulfonic acid polymer, is formed into a film using a T-die or a flat plate press, the film is formed by saponification, hydrogenation, and washing with water. Examples of the method include forming the film by immersing the film in a solution in which the additive is dissolved, and then removing the solvent by heating and washing with water and pickling as necessary.
Furthermore, the polymer solid electrolyte membrane obtained as described above may be subjected to heat annealing for the purpose of achieving stronger ionic bonds. In addition, a stretching operation may be performed for the purpose of orienting molecular chains and further improving the strength.

Hereinafter, the present invention will be described in detail based on Examples , Reference Examples, and Comparative Examples . Of course, these examples, reference examples, comparative examples are not intended to unduly limit the scope of the present invention.
( Reference Example 1)
10 g of dimethylformamide was added to 20 g of Aciplex-SS900 (trade name, solid content concentration 5%, solid content EW910, manufactured by Asahi Kasei Co., Ltd.), and 10 g of the solvent was distilled off using a rotary evaporator. To this solution, 2 g of a solution of 0.1 g of polyallylamine (aldrich, weight average molecular weight (Mw) of about 65,000, water removed from 20 wt% aqueous solution) dissolved in 20 g of dimethylformamide was mixed at room temperature, A mixed solution was obtained. 20 g of this mixed solution was put in a glass petri dish and heated on a hot plate set at 160 ° C. for 2 hours to remove the solvent, thereby obtaining a film-like product. This film was treated in hot water at 70 ° C. for 1 hour, subsequently treated in 2 mol / l hydrochloric acid at 60 ° C. for 1 hour, further treated in hot water at 70 ° C. for 1 hour, and then at room temperature. And dried in air to obtain a composite polymer solid electrolyte membrane having a thickness of about 57 μm. This polymer solid electrolyte membrane was cut out to 5 cm × 5 mm, and the dynamic viscoelastic behavior was measured at 30 ° C. to 300 ° C. at a rate of 10 ° C./min at a frequency of 35 Hz using a Levibron manufactured by Orientec. As a result, the peak temperature of α dispersion as viewed from tan δ was 130 ° C. Moreover, when a creep characteristic curve at 120 ° C. and a load of 16 kg / cm ² was measured for a sample cut into 7 cm × 1 cm using a tensile creep measuring instrument manufactured by Toyo Seiki Co., the creep deformation after 20 hours was about 80%. Met. Furthermore, when the proton conductivity of the membrane in 80 ° C. water was measured, it was 0.20 S / cm.

Here, the conductivity at 80 ° C. was determined as follows. After the electrolyte membrane was treated in hot water at 80 ° C., it was cut into a 1 cm width and a 7 cm length in a swollen state, and the thickness T was measured. This sample was attached to a two-terminal conductivity measuring cell for measuring conductivity in a swollen state. This cell was immersed in 80 ° C. ion-exchanged water, the resistance value R at a frequency of 10 kHz was measured by the AC impedance method, and the proton conductivity σ was calculated from the following equation.
σ = L / (R × T × W)
σ: Proton conductivity (S / cm)
T: Thickness (cm)
R: Resistance value (Ω)
L: Distance between two terminals (= 5cm)
W: Sample width (= 1 cm)

( Reference Example 2)
After adding 10 g of dimethylformamide to 20 g of Aciplex-SS900 (trade name, solid content concentration 5%, solid content EW910, manufactured by Asahi Kasei Corporation, perfluorocarbon sulfonic acid polymer), 10 g of the solvent was distilled off using a rotary evaporator. A solution prepared by dissolving 0.1 g of polyallylamine (aldrich, weight-average molecular weight (Mw) of about 65,000, water removed from 20 wt% aqueous solution) in 20 g of dimethylformamide was mixed at room temperature, and mixed solution Got. 20 g of this mixed solution was put in a glass petri dish and heated on a hot plate set at 160 ° C. for 2 hours to remove the solvent, thereby obtaining a film-like product. This film was treated in hot water at 70 ° C. for 1 hour, subsequently treated in 2 mol / l hydrochloric acid at 60 ° C. for 1 hour, further treated in hot water at 70 ° C. for 1 hour, and then at room temperature. And dried in air to obtain a composite polymer solid electrolyte membrane having a thickness of about 30 μm. This polymer solid electrolyte membrane was cut into 5 cm × 5 mm, and proton conductivity in vibron, tensile creep and 80 ° C. water was measured in the same manner as in Reference Example 1. As a result, the peak temperature of α dispersion observed by tan δ was 135. The creep deformation after 20 hours was approximately 60%, and the proton conductivity in water at 80 ° C. was 0.18 S / cm.

(Comparative Example 1)
20 g of Aciplex-SS900 (product name, solid content concentration 5%, solid content EW910, manufactured by Asahi Kasei Co., Ltd.) is placed in a glass petri dish and heated for 2 hours on a hot plate set at 160 ° C. Removal was performed to obtain a film. This film was treated in hot water at 70 ° C. for 1 hour, subsequently treated in 2 mol / l hydrochloric acid at 60 ° C. for 1 hour, further treated in hot water at 70 ° C. for 1 hour, and then at room temperature. And dried in air to obtain a composite polymer solid electrolyte membrane having a thickness of about 50 μm. This polymer solid electrolyte membrane was cut out to 5 cm × 5 mm, and proton conductivity in vibron, tensile creep and 80 ° C. water was measured in the same manner as in Reference Example 1. As a result, the peak temperature of α dispersion observed by tan δ was 118. The creep deformation after 20 hours was approximately 155%, and the proton conductivity in water at 80 ° C. was 0.21 S / cm.
From a comparison between this result and the results of Reference Examples 1 and 2, it was confirmed that the composite polymer solid electrolyte membrane of the present invention had high heat resistance.

( Reference Example 3)
After adding 10 g of dimethylformamide to 20 g of Aciplex-SS900 (trade name, solid content concentration 5%, solid content EW910, manufactured by Asahi Kasei Corporation, perfluorocarbon sulfonic acid polymer), 10 g of the solvent was distilled off using a rotary evaporator. A solution prepared by dissolving 0.4 g of polyallylamine (aldrich, weight average molecular weight (Mw) of about 65,000, water removed from 20 wt% aqueous solution) in 20 g of dimethylformamide was mixed at room temperature. Obtained. 20 g of this mixed solution was put in a glass petri dish and heated on a hot plate set at 160 ° C. for 2 hours to remove the solvent, thereby obtaining a film-like product. This film was treated in hot water at 70 ° C. for 1 hour, subsequently treated in 2 mol / l hydrochloric acid at 60 ° C. for 1 hour, further treated in hot water at 70 ° C. for 1 hour, and then at room temperature. And dried in air to obtain a composite polymer solid electrolyte membrane having a thickness of about 31 μm. Cut the solid polymer electrolyte membrane 5 cm × 5 mm, Vibron in the same manner as in Reference Example 1, the tensile creep was measured proton conductivity at 80 ° C. water peak temperature of α dispersion seen in tanδ 138 The creep deformation after 20 hours was approximately 40%, and the proton conductivity in water at 80 ° C. was 0.14 S / cm.

(Comparative Example 2)
After adding 10 g of dimethylformamide to 20 g of Aciplex-SS900 (trade name, solid content concentration 5%, solid content EW910, manufactured by Asahi Kasei Corporation, perfluorocarbon sulfonic acid polymer), 10 g of the solvent was distilled off using a rotary evaporator. A solution in which 1 g of polyallylamine (aldrich, weight average molecular weight (Mw) of about 65,000, water was removed from a 20 wt% aqueous solution) dissolved in 20 g of dimethylformamide was mixed at room temperature to obtain a mixed solution. It was. 20 g of this mixed solution was put in a glass petri dish and heated on a hot plate set at 160 ° C. for 2 hours to remove the solvent, thereby obtaining a film-like product.
This film was treated in hot water at 70 ° C. for 1 hour, subsequently treated in 2 mol / l hydrochloric acid at 60 ° C. for 1 hour, further treated in hot water at 70 ° C. for 1 hour, and then at room temperature. And dried in air to obtain a composite polymer solid electrolyte membrane having a thickness of about 55 μm. This polymer solid electrolyte membrane was cut out to 5 cm × 5 mm, and proton conductivity in vibron, tensile creep and 80 ° C. water was measured in the same manner as in Reference Example 1. As a result, the peak temperature of α dispersion observed by tan δ was 139. The creep deformation after 20 hours was approximately 36%, and the proton conductivity in water at 80 ° C. was 0.09 S / cm.

( Reference Example 4)
An electrolyte membrane was obtained in the same manner as in Reference Example 1 except that polyaniline (Wako Pure Chemical Industries, code number 581-66981) was used instead of polyallylamine. When proton conductivity in water, tensile creep, and 80 ° C. water was measured in the same manner as in Reference Example 1, the peak temperature of α dispersion observed by tan δ was 132 ° C., and the amount of creep deformation after 20 hours was approximately The proton conductivity in water at 75% and 80 ° C. was measured to be 0.19 S / cm.

( Reference Example 5)
An electrolyte membrane was obtained in the same manner as in Example 1 except that benzimidazole (manufactured by Wako Pure Chemical Industries, Ltd.) was used instead of polyallylamine. When the proton conductivity in water, tensile creep, and 80 ° C. water was measured in the same manner as in Reference Example 1, the peak temperature of α dispersion observed by tan δ was 128 ° C., and the amount of creep deformation after 20 hours was approximately When the proton conductivity in water at 85% and 80 ° C. was measured, it was 0.19 S / cm.

(Example 1 )
Tetrafluoroethylene and _{CF 2 = CFO (CF 2)} ( after alkaline hydrolysis and acid treatment Ew: 730) polymerization obtained precursor polymer with -SO ₂ F and 99 g, more zinc phthalocyanine (manufactured by Wako Pure Chemical Industries, (Purchase) 1g was melt kneaded at 270 ° C with a lab plast mill, and after cooling, 20g was formed into a film using a flat plate press at 280 ° C. This film was contacted in an aqueous solution in which potassium hydroxide (15% by weight) and dimethyl sulfoxide (30% by weight) were dissolved at 80 ° C. for 2 hours for alkali hydrolysis treatment. This film was washed with ion-exchanged water, then treated in a 2N aqueous hydrochloric acid solution at 65 ° C. for 2 hours, further washed with ion-exchanged water and air-dried to obtain an electrolyte membrane having a thickness of about 67 μm.
With respect to this electrolyte membrane, proton conductivity in vibron, tensile creep, and 80 ° C. water was measured in the same manner as in Reference Example 1. As a result, the peak temperature of α dispersion observed in tan δ was 141 ° C., and 20 hours later. The creep deformation was about 43%, and the proton conductivity measured in water at 80 ° C. was 0.22 S / cm.

(Comparative Example 3)
20 g of the precursor polymer (Ew after alkali hydrolysis and acid treatment: 730) obtained by polymerization of tetrafluoroethylene and CF ₂ = CFO (CF ₂ ) -SO ₂ F was added to a flat plate press at 280 ° C. Used to form a film. This film was contacted in an aqueous solution in which potassium hydroxide (15% by weight) and dimethyl sulfoxide (30% by weight) were dissolved at 80 ° C. for 2 hours for alkali hydrolysis treatment. This film was washed with ion-exchanged water, then treated in a 2N aqueous hydrochloric acid solution at 65 ° C. for 2 hours, further washed with ion-exchanged water and air-dried to obtain an electrolyte membrane having a thickness of about 67 μm. With respect to this electrolyte membrane, proton conductivity in vibron, tensile creep and 80 ° C. water was measured in the same manner as in Reference Example 1. As a result, the peak temperature of α dispersion as seen by tan δ was 128 ° C., and 20 hours later. The creep deformation was about 68%, and the proton conductivity measured in water at 80 ° C. was 0.25 S / cm.
The examples , reference examples and comparative examples are summarized in Table 1 below.

  The present invention exhibits an effect of improving high temperature durability and is suitable as a polymer solid electrolyte membrane for a fuel cell.

Claims (1)

A polymer solid electrolyte membrane comprising a perfluorocarbon sulfonic acid polymer and an additive, wherein the perfluorocarbon sulfonic acid polymer occupies a weight fraction of 60% or more and 99.9% or less with respect to the polymer solid electrolyte, A solid polymer electrolyte membrane, wherein the additive is phthalocyanine .