JP4773085B2 - Polyazole solution - Google Patents

Description

  The present invention relates to a polyazole solution, and relates to a solution obtained by dissolving polyazole in a proton solvent and its use.

  Heat resistant and chemically stable polyazole resins are used as engineering plastic films and electronic substrate materials. In particular, polyazole resin solutions are long, short fibers, non-woven fabrics, carbon fibers obtained by firing the fibers, various membranes, porous films, various paints, various structural materials, various insulating materials, solid polymer electrolyte fuel cell modifiers, fuel It is being studied for battery separator modification other than batteries, coating on various membrane surfaces, surface modification, medical hemodialysis membranes, plasma separation membranes, and the like. However, it is already known that it is difficult to obtain a stable polyazole resin solution (for example, Patent Document 1). Even when a polyazole resin is dissolved in a particular organic solvent, its solubility decreases with time due to the formation of aggregates and other factors. When the polymer concentration, including repeating azole units in solution, is relatively high, azole association occurs rapidly. In particular, when a proton solvent is used as a solvent, the solubility of the proton solvent is inferior, so that it cannot be dissolved at a high concentration.

Polyazole resins are known to dissolve in aprotic solvents such as acetone, dimethyl sulfoxide (DMSO), dimethylacetamide (DMAC), and dimethylformamide (DMF). However, these aprotic solvents themselves are harmful to the human body and are not good for the global environment. Furthermore, these aprotic solvents have a problem that they have high boiling points, require high temperatures for removal, take time for purification, and are inferior in productivity. Further, over time, for example, it decomposes during processing to generate harmful amine compounds, acetates, etc., which may be harmful depending on the purpose of use. In addition, the viscosity of the aprotic solution is poorly stable and may partially gel and become non-uniform.
WO2002 / 036661

  That is, the present invention relates to a polyazole solution, and is to obtain a proton solvent solution of polyazole that is stable over time.

As a result of intensive studies to solve the above problems, the present inventors have found that a polyazole compound can be dissolved in a proton solvent in the presence of an alkali metal oxide, thereby completing the present invention.
That is, the present invention
(1), a polyazole compound (A component), and an alkali metal hydroxide (B component) are dissolved in a protic solvent, and the mass% of the A component in the solution is 0.005 to 25 wt%; A polyazole solution, wherein the mass% of the component is 0.001 to 25 wt%, and the mass ratio (B / A) of the B component to the A component is 1 or less.
(2) The polyazole compound is a polyimidazole compound, a polybenzimidazole compound, a polybenzobisimidazole compound, a polybenzoxazole compound, a polyoxazole compound, a polythiazole compound, or a polybenzothiazole compound. The polyazole solution according to (1), which comprises at least one selected compound.
(3) The polyazole solution according to (1), wherein the polyazole compound is poly [2,2 ′-(m-phenylene) -5,5′-bisbenzimidazole].

  The polyazole solution of the present invention can be used for various industrial applications requiring heat resistance because a highly stable polyazole solution can be obtained over time without using an aprotic solvent harmful to the environment. .

The present invention will be specifically described below.
First, the protic solvent that can be used in the present invention will be described. The protic solvent of the present invention refers to a solvent that dissociates and releases protons such as water, alcohols, and fatty acids. Although the example of a protic solvent is shown below, if it is a solvent which dissociates and discharge | releases a proton, it will not be limited to this. Of the protic solvents, those other than water are used as protic organic solvents. Examples of protic solvents include water, aliphatic alcohols such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2 -Pentanol, 3-pentanol, 2-methyl-1-butanol, isopentyl alcohol, tert-pentyl alcohol, 3-methyl-2-butanol, neopentyl alcohol, 1-hexanol, 2-methyl-1-pentanol 4-methyl-2-pentanol, 2-ethyl-1-butanol, 1-heptanol, 2-heptanol, 3-heptanol, 1-octanol, 2-octanol, 2-methyl-1-hexanol, 1-nonanol, 3,5,5-trimethyl-1-hexano 1-decanol, 1-undecanol, 1-dodecanol, allyl alcohol, propanegyl alcohol, benzyl alcohol, cyclohexanol, 1-methyl-cyclohexanol, 2-methylcyclohexanol, 3-methylcyclohexanol, 4-methylcyclo Hexanol, α-terpineol, abietinol, fusel oil, those having a plurality of functional groups, 2-methoxyethanol, 2-ethoxyethanol, 2- (methoxymethoxy) ethanol, 2-isopropoxyethanol, 2-butoxyethanol, 2 -(Isopentyloxy) ethanol, 2- (hexyloxy) ethanol, 2-phenoxyethanol, 2- (benzyloxy) ethanol, furfuryl alcohol, tetrahydrofurfuryl alcohol , Diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol, triethylene glycol monomethyl ether, tetraethylene glycol, polyethylene glycol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, diethylene glycol Propylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, tripropylene glycol monomethyl ether, polypropylene glycol, diacetone alcohol, 2-chloroethanol, 1-chloro-2-propanol, 3-chloro-1,2- Propanediol, 1,3-dichloro-2-propanol, 2,2,2-to Fluoroethanol, 3-hydroxypropiononitrile, 2-aminoethanol, 2- (diethylamino) ethanol, 2- (diethylamino) ethanol, diethanolamine, N-butyldiethanolamine, triethanolamine, triisopropanolamine, 2,2′-thio Diethanol and diols include 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2, 3-butanediol, 1,5-pentanediol, 2-butene-1,4-diol, 2-methyl-2,4-pentanediol, 2-ethyl-1,3-hexanediol, glycerin, 2-ethyl- 2- (Hydroxymethyl) -1,3-propanedioe , 1,2,6-hexanetriol, as phenols, phenol, cresol, o- cresol, m- cresol, p- cresol, xylenols, as fluorinated alcohols of the general formula _{[CF 3 - (CF 2)} x - _{(CH 2)} y -OH] a and x = 1~20, y = 0~19 a and x + y is halogenated substituted alcohol, etc. 20 following ones or fluorine. These solvents may be used alone or in combination of two or more.

Next, the polyazole compound that can be used in the present invention will be described.
Polyazole compounds (component A) are rings such as polyimidazole compounds, polybenzimidazole compounds, polybenzobisimidazole compounds, polybenzoxazole compounds, polyoxazole compounds, polythiazole compounds, and polybenzothiazole compounds. It refers to a polymer of a hetero five-membered ring compound containing one or more nitrogen atoms, and may contain oxygen and sulfur in addition to nitrogen.
The molecular weight of the polyazole compound may be 300 to 500,000 in terms of weight average molecular weight.

In addition, the polyazole compound includes a hetero five-membered ring compound containing one or more nitrogen atoms in the above ring, p-phenylene group, m-phenylene group, naphthalene group, diphenylene ether group, diphenylene sulfone group, biphenylene group. In order to obtain heat resistance, the polymer is a polymer having a repeating unit of a compound bonded to a divalent aromatic group such as a terphenyl group or a 2,2-bis (4-carboxyphenylene) hexafluoropropane group. Specifically, a polyazole compound composed of polybenzimidazole is preferable. More preferable is poly [2,2 ′-(m-phenylene) -5,5′-bisbenzimidazole].
The polyazole compound that can be used in the present invention may further have an ion exchange group introduced at a free position of the molecular skeleton by using the following general modification method. The modified polyazole compound into which an ion exchange group has been introduced refers to a compound into which one or more amino groups, quaternary ammonium groups, carboxyl groups, sulfonic acid groups, phosphonic acid groups or the like have been introduced. By introducing this ion exchange, when a film is obtained by mixing other polymers described later, the bondability and adhesion between the polyazole resin and the other polymer can be improved, and the interface that occurs between the polyazole and the other polymer. Phenomena such as peeling can be suppressed and mechanical strength can be improved.
In addition, the introduction of an anionic ion exchange group into the polyazole resin can increase the ion exchange capacity of the entire electrolyte membrane when an electrolyte polymer is used as another polymer. When the membrane of the invention is used, a high output can be obtained during battery operation, which is useful. The amount of ion exchange groups introduced into the polyazole compound is preferably 0.1 to 3.5 meq / g, more preferably 0.5 to 2 meq / g, in terms of ion exchange capacity. Moreover, you may mix these with what does not have the above-mentioned ion exchange group.

These polyazole compounds and modified polyazole compounds may be used alone or in combination of two or more.
The method for modifying the polyazole compound is not particularly limited. For example, fuming sulfuric acid, concentrated sulfuric acid, anhydrous sulfuric acid and its complex, sultone such as propane sultone, α-bromotoluenesulfonic acid, chloroalkylphosphonic acid, etc. are used for polyazole. Thus, an ion exchange group may be introduced, or a polymer containing an ion exchange group may be polymerized at the time of synthesizing the monomer of the polyazole compound.
On the other hand, the alkali metal hydroxide (component B) that can be used in the present invention includes monovalent alkali metal hydroxides such as LiOH, NaOH, KOH, RbOH, CsOH, and FrOH. It is preferable from the viewpoint of solubility of the polyazole compound to be mixed.

Next, a method for producing a solution obtained by dissolving the above-mentioned polyazole compound and alkali metal hydroxide in a protic solvent will be described in detail.
For the dissolution of the polyazole compound, a protic solvent composed of a mixture of a protic organic solvent and water is used. However, the polyazole compound is not limited thereto as long as the affinity with the polyazole compound is good. When a mixture of a protic organic solvent and water is used, the mixing ratio of the protic organic solvent and water is preferably 0.5 or less, more preferably 0.3 or less, with respect to 1 for the protic organic solvent. Furthermore, 0.1 or less is preferable in order to increase the solubility of the polyazole compound.

Among the protic solvents, a high-boiling solvent in production requires a high temperature for removal and is not preferable. Therefore, the boiling point is a solvent having a boiling point of 250 ° C. or lower, preferably a solvent having a boiling point of 160 ° C. or lower, more preferably, Aliphatic alcohols having a boiling point of 160 ° C. or less, particularly preferably methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutyl alcohol, tert-butyl alcohol and the like.
On the other hand, the alkali metal hydroxide can use the same protic solvent as the polyazole compound. The alkali metal hydroxide can also be added as an aqueous solution.
In the present invention, the alkali metal hydroxide may be added directly to the polyazole compound solution, or the alkali metal hydroxide solution may be added to the polyazole compound solution. The latter is preferred.

  When mixing the polyazole compound (component A) and the alkali metal hydroxide (component B), the amount of component B added is such that the mass ratio of component B to component A is 1 or less, and the mass% of component A is 0.005 to 25 wt%, B component mass% is 0.001 to 25 wt%, more preferably A component mass% is 0.001 to 20 wt%, and B component mass% is 0.001. More preferably, the mass% of the A component is 0.01 to 15 wt%, and the mass% of the B component is 0.01 to 15 wt%. When the B component is small, an undissolved product of the polyazole compound is generated. When the B component is large, the solubility of the polyazole compound is improved, but precipitation of alkali metal hydroxide occurs.

Further, in order to obtain a molded body, the amount of the B component is preferably as small as possible, and the mass ratio of the B component to the A component is 1 or less, preferably 0.8 or less, and more preferably 0.5 or less.
In the dissolution, a method in which the component A is added to the aqueous solution of the component B, a protic organic solvent is added thereto, and then the mixture is heated is preferable for improving the solubility. Since dissolution temperature can raise solubility, it is so preferable that it is high, and 10-160 degreeC is preferable. Moreover, when exceeding the boiling point of the used protic organic solvent or the mixture of a protic organic solvent and water, it is preferable to use an autoclave. Moreover, it is preferable to perform normal stirring at the time of this dissolution. Further, the time required for heating is preferably 1 hour or longer, more preferably 3 hours or longer.

The polyazole solution can be filtered normally to remove undissolved impurities.
Further, the polyazole solution of the present invention can be used by mixing with other organic or inorganic reinforcing materials. Examples of organic reinforcing materials include polyethylene terephthalate (PET), polyethylene butarate (PBT), polyethylene naphthalate (PEN), polyester including liquid crystal polyesters, triacetyl cellulose (TAC), polyarylate, polyether, polycarbonate (PC ), Polysulfone, polyethersulfone, cellophane, aromatic polyamide, polyvinyl alcohol, polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), acrylonitrile-butadiene-styrene copolymer (ABS), Polymethyl methacrylate (PMMA), polyamide, polyacetal (POM), polyphenylene terephthalate (PPE), polybutylene terephthalate (PBT), polyphenol Rensulfide (PPS), polyamideimide (PAI), polyetheramide (PEI), polyetheretherketone (PEEK), polyimide (PI), polymethylpentene (PMP), polytetrafluoroethylene, (PTFE), fluorination Ethylene-propylene (FEP), tetrafluoroethylene-ethylene (ETFE) copolymer, polyvinylidene fluoride (PVDF), rebenzazole (PBZ) or polybenzoxazole (PBO), polybenzothiazole (PBT), and polybenzimidazole (PBI) Examples thereof include polymers and polyparaphenylene terephthalimide (PPTA). Other reinforcing materials include polysulfone (PSU), polyimide (PI), polyphenylene oxide (PPO), polyphenylene sulfoxide (PPSO), polyphenylene sulfide (PPS), polyphenylene sulfide sulfone (PPS / SO2), polyparaphenylene (PPP). , Polyphenylquinoxaline (PPQ), polyaryl ketone (PK), and polyether ketone (PEK) polymers, polyether sulfone PES), polyether ether sulfone (PEES), polyaryl sulfone, polyaryl ether sulfone (PAS) , Polyphenylsulfone (PPSU), and polyphenylenesulfone (PPSO2) polymers. Preferred polyimide polymers include polyetherimide polymers, as well as fluorinated polyimides, and polyetherketone polymers include polyetherketone (PEK), polyetheretherketone (PEEK), polyetherketone-ketone (PEKK), and polyetherether. Ketone-ketone (PEEKK), and polyetherketone etherketone-ketone (PEKEKK) polymers, and inorganic reinforcing materials such as basic magnesium, magnesium, magnesium borate, titanium diboride, graphite, aluminum oxide and these Hydrate, silicon oxide, titanium oxide, silicon carbide, silicon nitride, potassium titanate, aluminum borate, zinc oxide, magnesium sulfate, and composite materials thereof, aluminum oxide Um and hydrates thereof, silicon oxide, titanium oxide, potassium carbide, silicon nitride, titanate, aluminum borate, magnesium borate, titanium diboride, and graphite.
These reinforcing materials can be appropriately used those dissolved in a solvent that can be mixed with the polyazole solution of the present invention. These reinforcing materials may be used alone or in combination of two or more. Moreover, you may filter an undissolved substance after mixing. Depending on the application, the component derived from the alkali metal hydroxide of the component B is preferably removed after film formation. As a removal method, it may be extracted or neutralized after washing with water or swelling with a free solvent.
As a film forming method, the coating solution is applied to a petri dish, a glass plate, a film, or the like so that the thickness of the coating solution is uniform by using a blade coater, a gravure coater, a comma coater having a mechanism such as a blade, an air knife, or a reverse roll. The film can be cast to form a single-coated film while being controlled, or in the case of a long film, the film can be continuously cast to form a continuous film.

Further, it is possible to control the film thickness again with a blade, an air knife, or a roller before the film once cast or extruded is subjected to a drying process described later.
The manufactured film can be used without any limitation, but for example, engineering plastics for electronic materials and other applications using heat resistance and high strength, chemical resistance, gas barrier properties, and abrasion resistance. It can be used.
The solution of the present invention is applied to the surface of various membranes, membranes for solid polymer electrolyte fuel cells, electrodes and membrane electrode assemblies, battery separators other than fuel cells, membrane reinforcing materials, etc., and a polyazole resin layer Or by obtaining from the solution of the molded product mixed with the solution of the present invention, the decomposition and deterioration of the membrane and separator and the permeation of gas, solution and solvent can be reduced, and the mechanical strength can be improved. In addition, the durability and deterioration resistance of the membrane and separator can be improved. Moreover, the thickness of these polyazole resin layers can be arbitrarily set according to the function of the film | membrane.

The film forming method described above can be selected according to the viscosity of the solution and other properties, and is not limited. The polyazole solution may be applied many times by a free method.
In addition, it is preferable that the coating solution removes bubbles by a vacuum defoaming method as a pretreatment to form a film in terms of controlling the film thickness and quality. Further, in order to make bubbles easier to escape, it is possible to add a high boiling protic solvent having a boiling point higher than that of water in order to make the film thickness uniform. In addition, as a method for removing the solvent present in the formed film, a method such as a solvent dipping method in which a film is placed in an appropriate solution or solvent to remove the solvent can be used.
The film formed by the above method is subjected to normal drying. The drying temperature is preferably 40 to 250 ° C. If this temperature is too high, or if it is heated rapidly, bubbles and uneven thickness will occur during drying, and a normal electrolyte membrane with uniform film thickness accuracy cannot be obtained. Moreover, when too low, drying time will become long and productivity will fall. Also, this heat drying can be carried out in two stages, three stages, etc., and a method of obtaining a film having a uniform film thickness at the first stage and then heating at a higher temperature is also possible. When this method is used, the drying temperature at the first stage is lowered and the drying time is lengthened, whereby a film having no drying spots and high flatness can be obtained.
Heat drying is performed under hot air or low-humidity air, for example, but is constrained by a tenter or a metal frame, or is not constrained, for example, on a support that does not adhere to the membrane of the present invention or airflow. It can be dried by a method such as floating.
The film obtained by the above production method exhibits a yellow or reddish brown color by heat drying, and becomes a uniform film.

  The film obtained by the above production method may be subjected to a washing step of washing with an acid and / or water as necessary. Washing is performed for the purpose of removing the alkali hydroxide in the film. In this washing step, the acid, temperature, time, solvent, etc. can be controlled, and the resulting film can be washed under conditions that swell as necessary, thereby increasing the washing effect. .

  Acids used for cleaning with acids are inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, hydrogen peroxide, phosphonic acid, phosphinic acid, or tartaric acid, oxalic acid, acetic acid, formic acid, trifluoroacetic acid, aspartic acid, aminobenzoic acid. Acid, aminoethylphosphonic acid, inosine, glycerin phosphate, diaminobutyric acid, dichloroacetic acid, cysteine, dimethylcysteine, nitroaniline, nitroacetic acid, picric acid, picolinic acid, histidine, bipyridine, pyrazine, proline, maleic acid, methanesulfonic acid , Trifluoromethanesulfonic acid, toluenesulfonic acid, trichloroacetic acid and the like alone, or these inorganic acids and organic acids are water, methyl ethyl ketone, acetonitrile, propylene carbonate, nitromethane, dimethyl sulfoxide, N, N-dimethylformamide, N −Me -2-pyrrolidone, pyridine, methanol, ethanol, may be used as a solution in acetone.

In addition, since the membrane of the present invention uses a coating solution of a protic solvent, there are few impurities that are difficult to desorb and can be easily cleaned as compared with a method using a conventional aprotic solvent. .
In addition, cleaning with water is performed as necessary, and in particular, when cleaning with acid is performed for the purpose of removing the acid remaining in the film, impurities in the film can be obtained even without cleaning with acid. It can be carried out for the purpose of removal.
As the solvent used for washing, various organic solvents having a pH of 1 to 7 can be used in addition to water. When using water for washing | cleaning, it is preferable to fully carry out until the pH of washing water becomes 6-7.

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. The test methods for various physical properties in the present invention are as follows.
(1) Concentration of solid content The weight of a dry room temperature weighing bottle is precisely weighed and is designated as W0. About 10 g of the measurement object is put into the measured weighing bottle, precisely weighed, and set to W1. This was dried at 110 ° C. and 0.10 MPa or less for 3 hours or more, then cooled in a desiccator containing silica gel, and after reaching room temperature, weighed precisely to obtain W2. (W2-W0) / (W1-W0) is expressed as a percentage, and this is defined as the solid content concentration. The above is measured a total of 5 times and the average is taken as the solid content concentration.
(2) Measurement of polyazole amount The polyazole component in the polyazole solution was precipitated in a poor solvent of a polyazole solution such as water, sufficiently washed with the poor solvent, and then sufficiently dried. After sufficiently pulverizing the polyazole component, the polyazole component is dissolved in a deuterated solvent that can be dissolved at a concentration of 0.5 to 1%, and this solution is then subjected to Fourier Transform Nuclear Magnetic Resonance (FT-NMR). , JEOL Co., Ltd. EX-270 type), and the structure was determined by an organic elemental analysis method (elemental analyzer Yanaco CHN CODER MT-5 type (manufactured by Yanagimoto Co., Ltd.)) The amount of polyazole resin in the solution was calculated from the above azole structure.
(3) Quantification of alkali metal hydroxide Measure several types of samples in which the amount of alkali metal hydroxide added in the solution is changed, and use a plasma emission analyzer (ICPS-7000, manufactured by Shimadzu Corporation), A calibration curve of the added alkali metal oxide concentration and absorbance was prepared. Next, the absorbance of the electrolyte polymer solution of the present invention was measured, and the concentration was determined from a calibration curve.
(4) Water content measurement The water content in the solution was measured using a Karl Fischer moisture meter (MKS-20, manufactured by Kyoto Electronics Industry Co., Ltd.).
(5) Measurement of protic organic solvent other than water The organic solvent in the solution was analyzed and quantified by gas chromatography (GC-14A, manufactured by Shimadzu Corporation).
(6) Absorbance measurement After defoaming the solution to be measured, using a UV-VIS absorbance measurement device (manufactured by JASCO Corporation, V-550), the absorbance in the air of a quartz cell having an optical path length of 10 mm was used as a blank. The absorbance (ABS) at 850 nm when the measurement solution is put in the same cell is measured.
(7) Conductivity measurement A membrane sample is cut out in a wet state (a state immediately after immersing a hot water bath at a hot water temperature of 80 ° C. for 2 hours), and the thickness t is measured. This is mounted on a two-terminal conductivity measuring cell that measures the conductivity in the film length direction having a width of 1 cm and a length of 5 cm. This cell is placed in ion-exchanged water at 80 ° C., the resistance value r of the real component at a frequency of 10 kHz is measured by an alternating current impedance method, and the ionic conductivity σ is derived from the following equation.

σ = 1 / (r × t × w)
σ: Ionic conductivity (S / cm)
t: thickness (cm)
r: Resistance value (Ω)
l (= 5): film length (cm)
w (= 1): film width (cm)
Next, examples and comparative examples will be described.

[Example 1]
After sufficiently pulverizing 1 g of polybenzimidazole (Sigma Aldrich Japan Co., Ltd., weight average molecular weight 27000), adding 10 g of 8 wt% NaOH aqueous solution and 20 g of ethanol, the mixture is heated and stirred at 80 ° C. for 1 hr, and polybenzimidazole is sufficiently added. Then, 75 g of ethanol was added, and the mixture was heated and stirred at 80 ° C. The polybenzimidazole was dissolved and a reddish brown transparent polybenzimidazole solution was obtained. The absorbance of this solution was 0.01. Filtration was possible without applying pressure with a 0.45 μ polypropylene filter.
In this solution, polybenzimidazole was 1.0 wt%, NaOH (converted Na in the solution as a hydroxide) was 0.8 wt%, water was 8.7 wt%, and ethanol was 89.5 wt%. The same solution was placed in a sealed container of 30 ml and allowed to stand at room temperature for 30 days, but no precipitate was found.

In this solution, a perfluorocarbon sulfonic acid resin film (Asaplex (registered trademark), S1002, S1002, film thickness 50 μ) manufactured by Asahi Kasei Co., Ltd. was previously treated at 200 ° C. for 10 minutes, then immersed for 1 hour, pulled up, and 160 ° C. For 1 hour. Next, the film was immersed in a large amount of 2N-HCl aqueous solution for 2 hours at room temperature and washed. This membrane was dried at 25 ° C. and 55% RH to obtain a membrane in which the membrane surface layer portion was bonded to polybenzimidazole.
This membrane was installed so as to divide the tank in two and so as not to leak from each layer, so as to form a diaphragm having an area of 5 cm ² . A 10% aqueous methanol solution was added to one tank, and pure water was added to the other, and the amount of methanol in the pure water-side solution after 1 hr was measured by gas chromatography. As a result, when a similar experiment conducted without applying the solution of the present invention was performed, the amount of methanol in pure water was 0.1 wt% with respect to 0.5 wt%. In addition, the ionic conductivity was 0.19 S / cm before coating (only S1002), but 0.14 S / cm and the ionic conductivity did not decrease so much, and it was found that the permeation of methanol can be effectively suppressed. It was.

[Example 2]
A polybenzimidazole solution was prepared in the same manner as in Example 1. This solution is placed in a petri dish so that the thickness after drying is 10 μm, dried on a 45 ° C. hot plate kept horizontal for 2 hours, and then dried by heating in the same manner at 60 ° C. for 1 hour and at 80 ° C. for 1 hour. did. This membrane was placed in a solution of N, N-dimethylacetamide at 40 ° C. to swell, then placed in a 2N aqueous sulfuric acid solution at room temperature for 2 hours, washed and dried to obtain a brown membrane having a thickness of about 20 μm. It measured in 25 degreeC and 55-% RH atmosphere using the tension tester (Shimadzu Corp. make, AGS-1KNG) by the method prescribed | regulated to JISK7127. As a result, the tensile strength was 1000 kgf / cm ² , the tensile modulus was 4010 kgf / cm ² , the elongation was 30%, and the strength was equivalent to that of a normal engineering plastic film. This film has a strength equivalent to that of a conventional polybenzimidazole film, is obtained from a polyazole resin dissolved in a protic solvent, and can be used as a heat-resistant film for electronics because there are few impurities in the film.

[Example 3]
1 g of polybenzimidazole (manufactured by Sigma-Aldrich Japan Co., Ltd., weight average molecular weight 27000) was sufficiently pulverized, 5 g of 16 wt% NaOH aqueous solution and 20 g of ethanol were added, and the mixture was heated and stirred at 80 ° C. for 1 hr. The absorbance of this solution was 0.05. Filtration was possible without applying pressure with a 0.45 μ polypropylene filter.
In this solution, polybenzimidazole was 3.8 wt%, NaOH (converted Na in the solution as a hydroxide) was 3.1 wt%, water was 16.1 wt%, and ethanol was 77.0 wt%. The same solution was placed in a sealed container of 30 ml and allowed to stand at room temperature for 30 days, but no precipitate was found.

[Example 4]
5 g of polybenzimidazole (manufactured by Sigma-Aldrich Japan Co., Ltd., weight average molecular weight 27000) was sufficiently pulverized, and 10 g of 25 wt% NaOH aqueous solution and 20 g of ethanol were added, followed by heating and stirring at 80 ° C. for 1 hr. The absorbance of this solution was 0.08.
This solution was 14.3 wt% polybenzimidazole, 8.6 wt% NaOH (converted Na in the solution as a hydroxide), 20.0 wt% water, and 57.1 wt% ethanol. The same solution was placed in a sealed container of 30 ml and allowed to stand at room temperature for 30 days, but no precipitate was found.

[Comparative Example 1]
Polybenzimidazole (manufactured by Sigma-Aldrich Japan Co., Ltd., weight average molecular weight 27000) was sufficiently pulverized. The obtained powder was dried at 110 ° C. to a constant weight.
This powder was charged with 1 g and 99 g of ethanol in an inert gasification reactor and treated at 80 ° C. for 3 hours. The polybenzimidazole powder did not dissolve and resulted in precipitation.
[Comparative Example 2]
8 g of polybenzimidazole (manufactured by Sigma-Aldrich Japan Co., Ltd., weight average molecular weight 27000) was sufficiently pulverized, added with 5 g of 25 wt% NaOH aqueous solution and 5 g of ethanol, and then heated and stirred at 80 ° C. for 1 hr. The polybenzimidazole powder did not dissolve and resulted in precipitation.

  The polyazole solution of the present invention includes long, short fibers, non-woven fabrics, carbon fibers obtained by firing the fibers, various membranes, porous films, various paints, various structural materials, various insulating materials, solid polymer electrolyte fuel cell modifiers, Used for reforming battery separators other than fuel cells, applied to various membrane surfaces and used for surface reforming, medical hemodialysis membranes, plasma separation membranes, and the like.

Claims (3)

A polyazole compound (A component) and an alkali metal hydroxide (B component) are dissolved in a protic solvent, and the mass% of the A component in the solution is 0.005 to 25 wt%, and the mass% of the B component. 0.001 to 25 wt%, and the mass ratio (B / A) of the B component to the A component is 1 or less. The polyazole compound is one kind selected from a polyimidazole compound, a polybenzimidazole compound, a polybenzobisimidazole compound, a polybenzoxazole compound, a polyoxazole compound, a polythiazole compound, and a polybenzothiazole compound. The polyazole solution according to claim 1, comprising the above compound. The polyazole solution according to claim 1, wherein the polyazole compound is poly [2,2 '-(m-phenylene) -5,5'-bisbenzimidazole].