JP4411505B2 - POLYMER SOLID ELECTROLYTE MOLDED BODY, POLYMER SOLID ELECTROLYTE MEMBRANE AND METHOD FOR PRODUCING THEM - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a polymer solid electrolyte molded article and membrane excellent in durability and ion conductivity, and a method for producing the same.
[0002]
[Prior art]
As an example of an electrochemical device using a polymer solid electrolyte as an ionic conductor instead of a liquid electrolyte, a water electrolysis tank and a fuel cell can be mentioned. The polymer membrane used for these must have high proton conductivity as a cation exchange membrane and be sufficiently stable chemically, thermally, electrochemically and mechanically. For this reason, perfluorocarbon sulfonic acid membranes, mainly “Nafion (registered trademark)” manufactured by DuPont, USA, have been used as long-term usable products. However, if it is attempted to operate at a temperature exceeding 100 ° C., the moisture content of the membrane drops rapidly, and the membrane softens significantly. For this reason, in a fuel cell using methanol as a fuel, performance degradation occurs due to methanol permeation in the membrane, and sufficient performance cannot be exhibited. Further, even in a fuel cell that is currently studied mainly using hydrogen as a fuel and operated at around 80 ° C., it is pointed out that the cost of the membrane is too high as an obstacle to the establishment of fuel cell technology.
[0003]
As electrolyte membranes that can replace perfluorocarbon sulfonic acid membranes, so-called hydrocarbon polymer solid electrolytes in which ionic groups such as sulfonic acid groups are introduced into polymers such as polyether ether ketone, polyether sulfone, and polysulfone have been actively studied in recent years. ing. However, the hydrocarbon-based polymer solid electrolyte is more easily hydrated and swollen than perfluorocarbon sulfonic acid, and has a problem in durability under high humidity.
[0004]
As one of the measures for suppressing the swelling, mixing with a basic polymer is performed. This intends to suppress swelling by crosslinking the sulfonic acid group in the polymer solid electrolyte with a basic polymer. For example, a mixture of polyethersulfone having a sulfonic acid group or polyetheretherketone having a sulfonic acid group (acidic polymer) and polybenzimidazole (basic polymer) (International Patent Publication No. WO99 / 54389) Are known.
[0005]
Further, as described in JP-A-6-93114, International Publication No. WO99 / 6111, and JP-A-2001-522401, sulfonic acid groups that are ionic groups are crosslinked by covalent bonds. Therefore, the swelling is also suppressed.
[0006]
Although any of the above methods can suppress swelling, there is a problem that the ionic conductivity is lowered because the ionic group does not exhibit ionicity due to the crosslinking reaction.
[0007]
A sulfonated product of a styrene / divinylbenzene copolymer as a polymer solid electrolyte having a crosslinked structure is well known for being used in an early polymer electrolyte fuel cell. This polymer solid electrolyte was poor in durability of the polymer skeleton itself and did not show satisfactory properties as a fuel cell. JP-A-2-248434 and JP-A-2-245535 describe ion exchangers obtained by crosslinking reaction of chloromethyl groups in a polymer using a Lewis acid as a catalyst. However, a catalyst is required for the crosslinking reaction. Therefore, when a polymer and a catalyst are mixed to obtain a molded product, the catalyst remains, and when the polymer molded product is treated with a catalyst, a cross-linking reaction hardly occurs inside.
[0008]
[Problems to be solved by the invention]
An object of the present invention is to provide a crosslinked polymer solid electrolyte molded article, a crosslinked polymer solid electrolyte molded article excellent in ion conductivity and durability, suitable for a proton exchange membrane such as a fuel cell, and a method for producing the same. is there.
[0009]
[Means for Solving the Problems]
As a result of intensive research, the inventors have formed a film with a polymer having a crosslinkable group, and after the film has been subjected to a crosslinking treatment to form a crosslinked film, an ionic group is introduced into the polymer. The present inventors have found that a crosslinked polymer solid electrolyte membrane excellent in durability and ion conductivity can be obtained.
[0010]
That is, the present invention
(1) In a molded article of a polymer composition containing a polymer having one or more crosslinkable groups in the molecule alone or as a component, the crosslinkable groups are first subjected to a cross-linking reaction, and then an ionic group is added to the polymer. A method for producing a polymer solid electrolyte molded body, characterized in that it is introduced,
(2) The method for producing a solid polymer electrolyte molded article according to (1), wherein the ionic group is a sulfonic acid group or a phosphonic acid group,
(3) The method for producing a solid polymer electrolyte molded article according to either (1) or (2), wherein the crosslinkable group is a photocrosslinkable group or a heat crosslinkable group,
(4) The polymer solid electrolyte molded body according to any one of (1) to (3), wherein the crosslinkable group has a structure represented by the following general formulas (1) to (7): Production method,
[0011]
[Chemical formula 2]
(Wherein R ¹ ~ R ⁹ Is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a phenyl group, an aromatic group having 6 to 20 carbon atoms, or a halogen, ^Ten Represents a hydrocarbon group having 1 to 10 carbon atoms, Z represents a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, a halogen, or a nitro group, and n represents an integer of 1 to 4. )
(5) The method for producing a solid polymer electrolyte molded article according to any one of (1) to (4), wherein the polymer is polyethersulfone or polyetherketone,
(6) A polymer solid electrolyte molded body obtained by the method of (1) to (5),
(7) The method for producing a solid polymer electrolyte molded body according to (1) to (6), wherein the molded body is a film,
(8) A solid polymer electrolyte membrane obtained by the method according to (7),
It is.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail.
The number average molecular weight of the crosslinkable polymer is preferably between 1,000 and 1,000,000, and preferably between 5,000 and 500,000 because the physical properties and processability can be balanced.
[0013]
The ionic group represents a group capable of dissociating into ions such as a sulfonic acid group, a phosphonic acid group, a phosphoric acid group, and a carboxylic acid group. A sulfonic acid group or a phosphonic acid group is more preferable. A sulfonic acid group is preferable because it has high ion conductivity and a phosphonic acid group exhibits ion conductivity even at high temperatures. The amount of ionic groups in the polymer is preferably 0.1 to 5.0 mmol / g, more preferably 1.0 to 3.0 mmol / g. An ionic group can be introduced into the polymer by copolymerization or reaction.
[0014]
Examples of the crosslinkable group include a heat crosslinkable group, a photocrosslinkable group, and a reactive group. It is necessary that one or more of these crosslinkable groups be present in one molecule of the polymer, and it is preferably between 1 and 5,000 mmol / kg. These crosslinkable groups can be cross-linked by treating with a method according to the reactivity of each.
[0015]
Examples of the thermally crosslinkable group include multiple bonds such as ethylene group and ethynyl group, benzoxazine group, and oxazole group. These may have a substituent such as a methyl group or a phenyl group. More preferably, the following groups can be mentioned.
[0016]
[Chemical 3]
(Wherein R ¹ ~ R ⁹ Is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a phenyl group, an aromatic group having 6 to 20 carbon atoms, or a halogen, Z is a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, halogen, nitro In any group, n represents an integer of 1 to 4. These groups can be present as side chains or end groups in the polymer. The amount of the thermally crosslinkable group in the polymer is preferably 1 to 1,000 mmol / kg, more preferably 5 to 500 mmol / kg. It is preferably present as a terminal group of the polymer. The thermally crosslinkable group can be introduced into the polymer by reacting a compound having a thermally crosslinkable group as a copolymerization monomer or a terminal terminator.
[0017]
Crosslinking of the thermally crosslinkable group can be performed by heat treatment. The heat treatment is preferably performed in an inert gas such as nitrogen or argon. The temperature of heat processing can be performed in the range of 100-400 degreeC. The heat treatment time can be performed between 1 second and 100 hours. Depending on the case, you may add arbitrary well-known polymerization initiators, such as an azo polymerization initiator and a peroxide polymerization initiator.
[0018]
Examples of photocrosslinkable groups include benzophenone groups, α-diketone groups, acyloin groups, acyloin ether groups, benzyl alkyl ketal groups, acetophenone groups, polynuclear quinones, thioxanthone groups, acylphosphine groups, and ethylenically unsaturated groups. Can be mentioned. Among them, a combination of a group capable of generating a radical by light such as a benzophenone machine and a group capable of reacting with a radical such as an aromatic group having a hydrocarbon group such as a methyl group or an ethyl group is preferable. The following groups can be mentioned as
[0019]
[Formula 4]
These groups can exist as main chains, side chains, and end groups in the polymer. The amount of the heat crosslinkable group in the polymer is preferably 1 to 5,000 mmol / kg, and more preferably 5 to 5,000 mmol / kg. Such groups can be introduced into the polymer as copolymerizable monomers or terminal terminators. When using an ethylenically unsaturated group, light from benzophenones, α-diketones, acyloins, acyloin ethers, benzyl alkyl ketals, acetophenones, polynuclear quinones, thioxanthones, acylphosphines, etc. It is preferable to add a polymerization initiator.
[0020]
Crosslinking of the photocrosslinkable group can be performed by light irradiation. The light irradiation is preferably performed in an inert gas such as nitrogen or argon. The temperature during the treatment can be performed in the range of room temperature to 250 ° C. The irradiation time can be performed between 1 second and 100 hours.
[0021]
Examples of the reactive group include an amino group, an epoxy group, a hydroxy group, a halogen group, a halomethyl group, and a carboxyl group.
[0022]
Any known polymer can be used for the main chain of the polymer. Polyethersulfone, polyetherketone, polysulfide, polyphenylene, polybenzoxazole, polybenzimidazole, polybenzthiazole, polyketone, polysulfone and the like are preferable because of their excellent durability. Of these, polyethersulfone and polyetherketone are preferred because of ease of synthesis.
[0023]
Polyether sulfone and polyether ketone can be obtained by condensing an aromatic dihalogen compound having an electron-withdrawing group and a bisphenol compound. The condensation reaction can be carried out by a known method. For example, condensation can be performed by heating in the presence of a base in an organic solvent. Examples of the organic solvent include aprotic polar solvents such as N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N, N-dimethylformamide, sulfolane, and dimethyl sulfoxide. Of these, N-methyl-2-pyrrolidone is preferred. Examples of the base include potassium carbonate, sodium carbonate, potassium hydroxide, sodium hydroxide and the like. Of these, potassium carbonate is preferred. The water produced by the reaction of the bisphenol compound and the base can be removed by azeotropy with toluene or benzene. The azeotropic dehydration is preferably performed at 100 to 150 ° C. After the dehydration is completed, a condensation reaction can be performed. The condensation reaction can be carried out at 120 to 300 ° C. The reaction is preferably carried out in an inert gas atmosphere such as nitrogen or argon. After completion of the reaction, the solution can be reprecipitated by adding it to a solvent insoluble in polymers such as water and acetone. The reprecipitated polymer can be purified by a known method.
[0024]
Examples of the aromatic dihalogen compound include the following compounds.
[Chemical formula 5]
[0025]
Examples of the bisphenol compound include the following compounds.
[Chemical 6]
[0026]
Examples of the compound for introducing a thermally crosslinkable group into the polymer include the following compounds.
[Chemical 7]
[0027]
These compounds may be added to the system as raw materials from the beginning, or may be added when the condensation reaction has progressed to some extent.
[0028]
The thermally crosslinkable group represented by the general formula 3 can be obtained by reacting a phenolic hydroxyl group-terminated polymer with formaldehyde and an amine as described below.
[Chemical 8]
(Wherein R to R represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a phenyl group, or an aromatic group having 6 to 20 carbon atoms)
[0029]
Examples of the monomer for introducing a radical generating group into the polymer include the following compounds.
[Chemical 9]
[0030]
Examples of the monomer for introducing a group that reacts with a radical into the polymer include the following compounds.
[Chemical Formula 10]
[0031]
The radical generating group and the radical reactive group may be in the same polymer or in separate polymers. Two or more polymers having each group may be mixed, or a polymer having two groups may be used. When two or more kinds of polymers are used, the ionic group may be present in any polymer.
[0032]
Although the example of a crosslinkable polymer is shown below, it is not limited to these.
Embedded image
[0033]
The crosslinked polymer solid electrolyte of the present invention can be obtained by introducing an ionic group into the polymer after crosslinking the molded crosslinkable polymer. The crosslinkable polymer can be formed by any known method such as melting, kneading, casting, spinning, or stretching. A film is preferred as the molded body. The film can be formed by any method such as casting or melt molding, but it is preferably produced by casting from a solution. As the solvent, an aprotic polar solvent such as dimethyl sulfoxide, dimethylacetamide, N-methyl-2-pyrrolidone or dimethylformamide can be used. The concentration of the solution is preferably 1 to 50 wt%. A film can be obtained by casting the solution on a glass plate and drying the solvent. The thickness of the film is preferably 1 to 500 μm, more preferably 5 to 100 μm. As needed, you may mix inorganic compounds, such as a silica, another polymer. When the ionic group is a salt, it can be converted into an acid form by treatment with an acid after forming into a film. In that case, it is preferable to perform acid conversion after completion of the crosslinking reaction. When heat-treating the film, it is preferable to heat it while fixing it to a suitable jig in order to prevent shrinkage. When cross-linking is performed, a molded body made of the polymer electrolyte of the present invention can be made into a cross-linked body structure, but it can also be cross-linked after forming a composition molded body with another non-crosslinkable polymer. In that case, the non-crosslinkable polymer may contain an ionic group in the molecular chain or may not contain an ionic group. Examples of the basic structure of the non-crosslinkable polymer include polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, polyamides such as nylon 6, nylon 6,6, nylon 6,10, and nylon 12, polymethyl methacrylate, Polyacrylates such as polymethacrylates, polymethylacrylates, polyacrylates, polyacrylate resins, polymethacrylate resins, various polyolefins including diene polymers, polyurethane resins, cellulose acetate, ethyl cellulose Cellulosic resins such as polyarylate, aramid, polycarbonate, polyphenylene sulfide, polyphenylene oxide, polysulfone, polyethersulfone, polyetheretherketone Polyetherimide, polyimide, polybenzoxazole, polybenzthiazole, polybenzimidazole, and aromatic polymers such as polyamide-imide, not particularly limited.
[0034]
The ionic group represents a group capable of dissociating into ions such as a sulfonic acid group, a phosphonic acid group, a phosphoric acid group, and a carboxylic acid group. A sulfonic acid group or a phosphonic acid group is more preferable. A sulfonic acid group is preferable because it has high ion conductivity and a phosphonic acid group exhibits ion conductivity even at high temperatures. The amount of ionic groups in the polymer is preferably 0.1 to 5.0 mmol / g, more preferably 1.0 to 3.0 mmol / g.
[0035]
Examples of the treatment for introducing an ionic group into the polymer include treating the polymer molded body with a sulfonating agent such as sulfuric anhydride, a complex of sulfuric anhydride, fuming sulfuric acid, concentrated sulfuric acid, and chlorosulfonic acid. A method of reacting a sulfonating agent in a state where the polymer is dissolved in a solvent inert to the sulfonating agent, a method of reacting a sulfonating agent in a state where the polymer is swollen with an appropriate solvent, or a direct sulfonation of the polymer The sulfonation reaction can be carried out by a method such as a method of reacting with an agent. The sulfonating agent may be used as it is, or may be used in a state dissolved and dispersed in an appropriate solvent. The reaction can be carried out in the gas phase or liquid phase. Appropriate conditions can be used for the reaction temperature between −100 and 100 ° C. Further, in the molded article containing the crosslinkable group of the present invention, as a unit constituting the polymer, the ratio of the unit susceptible to the sulfonation reaction and the unit difficult to undergo the sulfonation reaction may be adjusted, the reaction temperature, the reaction time, and the like. The amount of sulfonic acid groups introduced into the polymer can be controlled by changing the sulfonation conditions such as.
[0036]
The polymer solid electrolyte membrane of the present invention can be used as a proton exchange membrane for water electrolysis or a fuel cell. Moreover, the polymer solid electrolyte of this invention can be used as a binder at the time of joining a catalyst to an electrode.
[0037]
【Example】
EXAMPLES Hereinafter, although this invention is demonstrated concretely using an Example, this invention is not limited to these Examples. Various measurements were performed as follows.
[0038]
(Measurement of film thickness)
The thickness of the film was measured using a film thickness meter (PEAKOCK DIGITAL GAUGE D-10 / OZAKI MFG. CO., LTD). The thickness of three random points in the sample was measured, and the average of them was taken as the film thickness.
[0039]
(Ion conductivity measurement)
A platinum wire (diameter: 0.2 mm) was pressed against the surface of a strip-shaped membrane sample on a probe for self-made measurement (made of polytetrafluoroethylene), and a constant temperature and humidity oven at 80 ° C and 95% RH (Nagano Science Co., Ltd.) The sample was held in Machine Works, LH-20-01), and the AC impedance at 10 KHz between the platinum wires was measured by SOLARTRON 1250 FREQUENCY RESPONSE ANALYSER. The measurement was performed while changing the distance between the electrodes, and the conductivity in which the contact resistance between the film and the platinum wire was canceled was calculated from the gradient obtained by plotting the distance between the electrodes and the measured resistance value.
Conductivity [S / cm] = 1 / film width [cm] × film thickness [cm] × resistance interelectrode gradient [Ω / cm]
[0040]
(Polymer logarithmic viscosity)
The N-methyl-2-pyrrolidone solution having a polymer concentration of 0.25 g / dl was measured at 30 ° C. using an Ostwald viscometer.
[0041]
(Water resistance test)
50 mg of polymer electrolyte membrane was sealed in a glass ampoule together with 5 ml of ion exchange water. The ampoule was heated at 105 ° C. for 3 days. After cooling, the ampule was opened, and the solid matter was collected with a 1G2 glass filter. The filter was dried under reduced pressure at 80 ° C. overnight, and the weight of solid content was determined from the weight before and after filtration to determine the weight reduction rate.
Weight reduction rate [%] = residue weight [mg] / 50 × 100
[0042]
(Quantification of ionic groups)
100 mg of the polymer electrolyte membrane was immersed in 50 ml of 0.01N NaOH aqueous solution and stirred at 25 ° C. overnight. Then, neutralization titration with 0.05N HCl aqueous solution was performed. For neutralization titration, a potentiometric titrator COMMITITE-980 manufactured by Hiranuma Sangyo Co., Ltd. was used. The amount of ionic groups is determined by the following formula.
Ionic group content [meq / g] = (10-titer [ml]) / 2
[0043]
Example 1
2.872 g (10.0 mmol) of 4,4′-dichlorodiphenylsulfone, 3.329 g (9.5 mmol) of biphenol, 1.589 g (11.5 mmol) of potassium carbonate, 17 ml of N-methyl-2-pyrrolidone and 3 ml of toluene The flask was placed in a 100 ml branch flask equipped with a nitrogen introduction tube, a stirring blade, a Dean Stark trap, and a thermometer, and heated in a nitrogen stream while stirring in an oil bath. After dehydration by azeotropy with toluene at 140 ° C., all the toluene was distilled off. Thereafter, the temperature was raised to 200 ° C. and heated for 15 hours. After the reaction solution was cooled to 140 ° C., 3 ml of N-methyl-2-pyrrolidone containing 0.060 g (0.5 mmol) of 4-hydroxystyrene and 3 ml of toluene were added and further stirred for 2 hours. Thereafter, the solution cooled to room temperature was poured into 500 ml of pure water to reprecipitate the polymer. The filtered polymer was dried at 50 ° C. under reduced pressure. Thereafter, the polymer was dissolved in N, N-dimethylacetamide and purified by reprecipitation in acetone. The logarithmic viscosity of the polymer was 0.58 dl / g. A solution obtained by dissolving 0.4 g of the obtained polymer in 1.6 g of dimethylacetamide was cast on a glass plate with a thickness of 0.02 cm, and dried under reduced pressure at 70 ° C. for 3 days. After peeling off the film from the glass plate, it was fixed to a metal frame and treated at 200 ° C. for 1 hour in a nitrogen atmosphere. The obtained membrane was immersed in concentrated sulfuric acid at 50 ° C. for 5 hours, and then washed with water until no acid could be detected. When the washed film was air-dried, a transparent film having a thickness of 0.0039 cm was obtained. The ionic group concentration of the membrane was 3.1 meq / g. In the water resistance test, the weight loss rate was 0%, and the ionic conductivity was 0.43 S / cm, indicating good durability and ionic conductivity.
[0044]
(Example 2)
4,4′-dichlorodiphenyl sulfone 1.198 g (4.2 mmol), 4,4′-difluorobenzophenone 1.272 g (5.8 mmol), 2,2-bis (4-hydroxy-3-methylphenyl) propane 2 .563 g (10.0 mmol), 1.589 g (11.5 mmol) of potassium carbonate, 20 ml of N-methyl-2-pyrrolidone, 3 ml of toluene with a 100 ml branch equipped with a nitrogen inlet tube, stirring blade, Dean-Stark trap and thermometer It put into the flask and heated under nitrogen stream, stirring in an oil bath. After dehydration by azeotropy with toluene at 140 ° C., all the toluene was distilled off. Thereafter, the temperature was raised to 200 ° C. and heated for 15 hours. Thereafter, the solution cooled to room temperature was poured into 500 ml of pure water to reprecipitate the polymer. The filtered polymer was dried at 50 ° C. under reduced pressure. Thereafter, the polymer was dissolved in N, N-dimethylacetamide and purified by reprecipitation in acetone. The logarithmic viscosity of the polymer was 0.61 dl / g. A solution obtained by dissolving 0.4 g of the obtained polymer in 1.6 g of dimethylacetamide was cast on a glass plate with a thickness of 0.02 cm, and dried under reduced pressure at 70 ° C. for 3 days. After peeling off the film from the glass plate, it was fixed to a metal frame and irradiated with a UV lamp at 50 ° C. for 1 hour in a nitrogen atmosphere. The obtained film was immersed in concentrated sulfuric acid at 30 ° C. for 7 hours, and then washed with water until no acid could be detected. When the washed film was air-dried, a transparent film having a thickness of 0.0036 cm was obtained. The ionic group concentration of the membrane was 3.4 meq / g. In the water resistance test, the weight loss rate was 0%, and the ionic conductivity was 0.44 S / cm, indicating good durability and ionic conductivity.
[0045]
(Comparative Example 1)
3.04 g (6.2 mmol) of 4,4′-dichlorodiphenylsulfone-3,3′-disulfonic acid sodium salt, 1.091 g (3.8 mmol) of 4,4′-dichlorodiphenylsulfone, 1.862 g (10.10) of biphenol. 0 mmol), 1.589 g (11.5 mmol) of potassium carbonate, 17 ml of N-methyl-2-pyrrolidone and 3 ml of toluene into a 100 ml branch flask equipped with a nitrogen inlet tube, stirring blade, Dean-Stark trap, thermometer, and oil. The mixture was heated in a nitrogen stream while stirring in a bath. After dehydration by azeotropy with toluene at 140 ° C., all the toluene was distilled off. Thereafter, the temperature was raised to 200 ° C. and heated for 15 hours. The solution cooled to room temperature was poured into 500 ml of pure water to reprecipitate the polymer. The filtered polymer was dried at 50 ° C. under reduced pressure. The logarithmic viscosity of the polymer was 0.78 dl / g. A solution obtained by dissolving 0.4 g of the obtained polymer in 1.6 g of dimethylacetamide was cast on a glass plate with a thickness of 0.02 cm, and dried under reduced pressure at 70 ° C. for 3 days. Thereafter, the membrane was treated with 1 mol / L sulfuric acid at 80 ° C. for 1 hour to convert the sulfonic acid group to the acid form, and further washed with water until no acid could be detected. When the washed film was air-dried, a transparent film having a thickness of 0.0033 cm was obtained. The ionic group concentration of the membrane was 2.2 meq / g. In the water resistance test, the membrane was dissolved and the solid content could not be recovered. The ionic conductivity was 0.29 S / cm.
[0046]
(Comparative Example 2)
1.081 g (2.2 mmol) of sodium 4,4′-dichlorodiphenylsulfone-3,3′-disulfonate, 2.240 g (7.8 mmol) of 4,4′-dichlorodiphenylsulfone, 1.862 g (10.10) of biphenol. 0 mmol), 1.589 g (11.5 mmol) of potassium carbonate, 17 ml of N-methyl-2-pyrrolidone and 3 ml of toluene into a 100 ml branch flask equipped with a nitrogen inlet tube, stirring blade, Dean-Stark trap, thermometer, and oil. The mixture was heated in a nitrogen stream while stirring in a bath. After dehydration by azeotropy with toluene at 140 ° C., all the toluene was distilled off. Thereafter, the temperature was raised to 200 ° C. and heated for 15 hours. The solution cooled to room temperature was poured into 500 ml of pure water to reprecipitate the polymer. The filtered polymer was dried at 50 ° C. under reduced pressure. The logarithmic viscosity of the polymer was 0.82 dl / g. A solution obtained by dissolving 0.4 g of the obtained polymer in 1.6 g of dimethylacetamide was cast on a glass plate with a thickness of 0.02 cm, and dried under reduced pressure at 70 ° C. for 3 days. Thereafter, the membrane was treated with 1 mol / L sulfuric acid at 80 ° C. for 1 hour to convert the sulfonic acid group to the acid form, and further washed with water until no acid could be detected. When the washed film was air-dried, a transparent film having a thickness of 0.0035 cm was obtained. The ionic group concentration of the membrane was 0.6 meq / g. The weight loss rate in the water resistance test was 0%. The ionic conductivity was as low as 0.06 S / cm.
[0047]
【The invention's effect】
According to the present invention, a solid polymer electrolyte membrane having excellent durability and ion conductivity can be obtained.

Claims (7)

In a molded article of a polymer composition containing a polymer having one or more crosslinkable groups in the molecule alone or as a component, the crosslinkable groups are first subjected to a crosslinking reaction, and then ionic groups are introduced into the polymer. A method for producing a polymer solid electrolyte molded body characterized by the above. Ionic group is sulfonic acid group The method for producing a polymer solid electrolyte molded body according to claim 1, wherein:  The method for producing a solid polymer electrolyte molded body according to any one of claims 1 to 2, wherein the crosslinkable group is a photocrosslinkable group or a heat crosslinkable group. The method for producing a polymer solid electrolyte molded body according to any one of claims 1 to 3, wherein the crosslinkable group has a structure represented by the following general formula (4) or (7).
(Wherein R ^{4 to} R ⁶ are any one of a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a phenyl group, an aromatic group having 6 to 20 carbon atoms, and a halogen, and R ¹⁰ is one having 1 to ¹⁰ carbon atoms. (Z represents a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, a halogen, or a nitro group, and n represents an integer of 1 to 4).  The method for producing a solid polymer electrolyte molded article according to any one of claims 1 to 4, wherein the polymer is polyethersulfone or polyetherketone.   A polymer solid electrolyte molded body obtained by the method according to claim 1. A polymer solid electrolyte membrane, wherein the molded product according to claim 6 is a membrane .