JP2007262346A - Solid electrolyte film and method for producing the same, production equipment and electrode composite and fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To mass-produce a solid electrolyte film having constant quality and high proton conductivity. <P>SOLUTION: The solid electrolyte film 70 is obtained by preparing a dope containing a precursor of the solid electrolyte, casting the dope from a casting die onto a running casting band, forming a cast film on the casting band and peeling the cast film as a precursor film 65 from the casting band. A coating apparatus 110 is designed to coat one surface 301 of the precursor film 65 with a first liquid 300, thereby afford a hydrogen-substituted film 65a from the precursor film 65 by coating the first liquid 300 and wash the hydrogen-substituted film 65a after the acid treatment with water. In a drying chamber 84, the hydrogen-substituted film 65a is dried to provide the solid electrolyte film 70. The acid treatment can be carried out in an online system. That is, the film 70 having the high proton conductivity can continuously be mass-produced. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a solid electrolyte film, a manufacturing method thereof, a manufacturing facility, an electrode membrane composite, and a fuel cell, and more particularly, a solid electrolyte film having proton conductivity and used in a fuel cell, and a manufacturing method thereof, The present invention relates to a manufacturing facility, an electrode membrane composite, and a fuel cell.

  Fuel cells are attracting attention as next-generation fuels that can improve environmental pollution and energy problems. The fuel cell has a plurality of stacked fuel cells (also referred to as electrode membrane composite (MEA)), and these fuel cells are electrically connected in series. The fuel cell has an anode electrode and a cathode electrode connected by an external circuit, and a solid electrolyte film sandwiched between these electrodes. A typical process in which the fuel cell generates an electromotive force is as follows. First, when a hydrogen atom-containing substance is supplied to the cathode electrode, the hydrogen atoms become protons in the cathode electrode. Next, this proton passes through the solid electrolyte film and combines with oxygen at the anode electrode, so that an electromotive force can be generated between the two electrodes of the fuel cell.

  Recently, solid electrolyte films (referred to as organic polymer type films) formed of polymers have attracted attention among solid electrolytes. Since this organic polymer film has the characteristics that the operating temperature is low and it can be reduced in size and weight, it is expected to be used for a fuel cell for home use or in-vehicle use. Therefore, the organic polymer type film is required to have characteristics such as high proton conductivity, excellent heat resistance, and uniform in-plane characteristics.

  By the way, as a method for forming a polymer into a film, there are a melt film forming method and a solution film forming method as well known. The former can produce a film without using a solvent, but there are problems that the polymer is modified by heating and impurities in the raw polymer remain in the film as they are. On the other hand, although the latter has problems in equipment such as solution production equipment and solvent recovery equipment, the temperature during heating may be low, and it is possible to remove impurities in the polymer in the solution production process. There is. Furthermore, the latter also has an advantage that a film excellent in flatness and smoothness can be produced as compared with the former film.

  In the solution casting method, a dope containing an organic compound as a raw material and a solvent is cast on a support to form a cast film, and then the cast film is peeled off from the support and further dried by a drying means. This is a method of drying to form a film, and is widely used not only as a method for producing an organic polymer film but also as a method for producing a polymer film for optical applications. However, the organic polymer film is an organic polymer that satisfies the above-mentioned requirements because it is made of a polymer compound and is sensitive to temperature and humidity, and it is difficult to adjust the reaction level. It is difficult to manufacture a mold film.

  Therefore, first, as a method for producing an organic polymer film excellent in quality and heat resistance, for example, a method of producing by a solution casting method using a dope containing an acidic group-containing polymer (see, for example, Patent Document 1) Alternatively, a method has been proposed in which a dope containing an acidic group-containing polymer is made into a gel film by a solution casting method, and then washed with water and dried to form a film (see, for example, Patent Document 2). In addition, as a method for producing an organic polymer film excellent in high proton conductivity, heat stability and processability, a film formed by a solution casting method is water-soluble and an organic compound having a boiling point of 100 ° C. or higher. There has been proposed a method of dipping in an aqueous compound solution to cause equilibrium swelling and then drying it (see, for example, Patent Document 3).

  In addition, as a method for producing an organic polymer film having high proton conductivity and excellent mechanical strength, a dope containing an ion conductive component is formed into a film by a casting method, and then immersed in a solvent to dissolve in water. A method of removing the compound and drying it has been proposed (see, for example, Patent Document 4). Further, Patent Documents 5 to 7 propose an organic polymer film having high proton conductivity formed from a dope containing a predetermined polyarylene by a solution casting method.

In addition, as a method for producing an organic polymer film having high proton conductivity, a film is formed from a dope containing a polymer containing a polymer having a sulfonic acid group (see, for example, Patent Document 8) or a dope containing a polymer. Thereafter, a method of acid-treating and sulfonating this has been proposed (for example, see Patent Document 9).
JP-A-2005-232240 JP 2005-235466 A Japanese Patent Laid-Open No. 2005-248128 JP 2005-310443 A JP 2004-079378 A JP-A-2005-146018 JP 2005-239833 A JP 2005-268144 A JP 2005-268145 A

  Since both methods of Patent Documents 8 and 9 are so-called off-line manufacturing methods in which film formation and acid treatment are performed in different production lines, it is difficult to manufacture films continuously and in large quantities. Regardless of these methods, Patent Documents 1 to 7 are also manufacturing methods on a small scale, and are not considered methods for mass production. Further, Patent Documents 5 to 7 describe that various organic polymer films can be produced by a solution casting method, but no specific method is described.

  The present invention aims to solve the above-mentioned problems, and has a high proton conductivity and a uniform proton conductivity, and a manufacturing method and a manufacturing method capable of continuously and mass-producing this solid electrolyte film. The present invention relates to an equipment, and an electrode membrane composite and a fuel cell using the solid electrolyte film.

  In the method for producing a solid electrolyte film of the present invention, in the method for producing a solid electrolyte film, a precursor film containing a polymer which is a precursor of a solid electrolyte is contacted with a liquid containing an acid which is a proton donor. A first step of bringing the liquid having a proton concentration of 0.05 mol / l or more into contact with one side of the precursor film having a hydrogen-substituted film in which the cation species are replaced with hydrogen atoms; and the hydrogen substitution A second step of cleaning the film; and a third step of drying the hydrogen-substituted film to form a solid electrolyte film containing the solid electrolyte.

  It is preferable that the temperature of the precursor film is 30 ° C. or higher and the glass transition temperature of the precursor film or lower.

  In the first step, it is preferable to heat the other surface side after bringing a solution having a proton concentration lower than that of the liquid into contact with the other surface of the precursor film. The difference in proton concentration between the liquid and the solution is preferably 0.05 mol / l or more. Furthermore, it is preferable that the formula amount of the liquid and the anion contained in the solution is 40 or more and 1000 or less. Pure water may be used for the solution.

  The first step, the second step, and the third step are preferably performed continuously.

  It is preferable that at least one temperature of the solution and the solution is 30 ° C. or higher and a glass transition temperature of the precursor film or lower.

  A fourth step of casting a dope containing an organic solvent and the polymer on a traveling support from a casting die to form a casting film; and using the casting film as the precursor film from the support. And a fifth step of peeling. Moreover, it is preferable that the said 1st process, the said 2nd process, the said 3rd process, the said 4th process, and the said 5th process are performed continuously.

（ただし、Ｘは水素原子を除くカチオン種、ＹはＳＯ_２ 、Ｚは化４の（Ｉ）または（II）に示す構造であり、ｎとｍとは０．１≦ｎ／（ｍ＋ｎ）≦０．５を満たす。）

The polymer is preferably a hydrocarbon polymer. The hydrocarbon polymer is preferably an aromatic polymer. Furthermore, the aromatic polymer is preferably a copolymer composed of structural units represented by the general formulas (I) to (III) of Chemical Formula 3.

(However, X is a cation species excluding a hydrogen atom, Y is SO ₂ , Z is a structure shown in Chemical Formula (I) or (II), and n and m are 0.1 ≦ n / (m + n) ≦ 0.5 is satisfied.)

  Further, the present invention provides the precursor film having a cationic species in a manufacturing facility for a solid electrolyte film in which a liquid containing an acid as a proton donor is brought into contact with a precursor film containing a polymer as a solid electrolyte precursor. A contact device for bringing the liquid into contact with one side of the heating device, a heating device for heating the one side of the precursor film, and generating a hydrogen-substituted film in which the cation species are replaced with hydrogen atoms from the precursor film, and It has a washing | cleaning apparatus which wash | cleans a hydrogen substitution film, and the drying apparatus which dries the said hydrogen substitution film and carries out the solid electrolyte film containing the said solid electrolyte, It is characterized by the above-mentioned.

  The contact device includes an other surface contact device for bringing a solution having a proton concentration lower than that of the liquid into contact with the other surface of the precursor film, and the heating device heats the other surface side of the precursor film. It is preferable that the other surface heating device generates a hydrogen substitution film in which the cation species is substituted with hydrogen atoms from the precursor film.

  A cast film forming apparatus for forming a cast film by casting a dope containing a polymer that is a precursor of a solid electrolyte and an organic solvent from a casting die on a traveling support; and It is preferable to have a peeling device that peels off as a precursor film from a support.

  The electrode membrane composite of the present invention comprises a solid electrolyte film manufactured by the above-described manufacturing method, and is closely attached to one surface of the solid electrolyte film, and the protons from a hydrogen atom-containing substance supplied from the outside. An anode electrode for generating, and a cathode electrode that is provided in close contact with the other surface of the solid electrolyte film, and synthesizes the proton that has passed through the solid electrolyte film and water composed of gas supplied from the outside. It is characterized by having.

  A fuel cell according to the present invention comprises: the electrode membrane composite according to claim 18; and an assembly provided in contact with an electrode of the electrode membrane composite for transferring electrons between the anode electrode and the cathode electrode and the outside. It is characterized by having.

  According to the method for producing a solid electrolyte film of the present invention, one side of the precursor film having a cationic species is brought into contact with the liquid having a proton concentration of 0.05 mol / l or more, and the one side is heated, A first step of forming a hydrogen-substituted film in which the cation species are replaced with hydrogen atoms; a second step of washing the hydrogen-substituted film; and drying the hydrogen-substituted film to form a solid electrolyte film containing the solid electrolyte. Therefore, the solid electrolyte film having high proton conductivity and uniform proton conductivity, and the solid electrolyte film can be produced continuously and in large quantities. In addition, an electrode membrane assembly using this solid electrolyte film exhibits excellent proton conductivity. In addition, a fuel cell using this electrode membrane assembly exhibits an excellent electromotive force.

  Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the embodiments described here. First, the solid electrolyte film according to the present invention will be described, and then the method for producing the solid electrolyte film will be described.

〔material〕
In the present invention, a compound having a cationic species is used as the polymer component of the dope used in the production method described later. In particular, the polymer composed of the substance shown in Chemical Formula 3 is a so-called solid electrolyte precursor. By subjecting a film containing this precursor (hereinafter referred to as a precursor film) to proton substitution, a solid electrolyte is generated from the precursor in the precursor film. Thus, a film including a solid electrolyte (hereinafter referred to as a solid electrolyte film) can be produced from the precursor film by proton substitution. In the present specification, proton substitution refers to substitution of a cation species other than a hydrogen atom in a polymer with a hydrogen atom. The cationic species means an atom or an atomic group that generates a cation when ionized. This cationic species need not be monovalent. In the present specification, unless otherwise specified, a cation refers to a cation other than a proton, and a cation species refers to an atom that can be a cation except a hydrogen atom.

  For example, when producing a precursor film, a dope containing the precursor shown in Chemical Formula 3 is prepared, the dope is cast on a support, and the cast film formed on the support is peeled off. A precursor film can be produced. And this solid precursor film can be manufactured by carrying out proton substitution of this precursor film, and substituting X of the substance shown in chemical formula 3 contained in a precursor film to H.

  Moreover, the precursor film which consists of a precursor shown to Chemical formula 3 makes the moisture absorption expansion coefficient and proton conductivity of the solid electrolyte film manufactured by proton substitution compatible. When n / (m + n) <0.1 in the substance shown in Chemical Formula 3, there are few proton acceptors in the precursor film, and proton conduction paths, so-called proton channels may not be formed sufficiently. Therefore, a solid electrolyte film produced by proton substitution may not exhibit proton conductivity sufficient for practical use. On the other hand, when n / (m + n)> 0.5 in the substance shown in Chemical Formula 3, the water absorption of the solid electrolyte film is increased, so that the expansion coefficient due to water absorption, that is, the water absorption expansion coefficient is increased. The solid electrolyte film tends to deteriorate.

  Preferred cations in the substance shown in Chemical Formula 3 are preferably alkali metal cations, alkaline earth metal cations, and ammonium cations, and more preferably calcium ions, barium ions, quaternary ammonium ions, lithium ions, sodium ions, and potassium ions. In addition, even if it manufactures a film with a cationic seed | species without replacing X in the compound shown in Chemical formula 3 with H (hydrogen atom), the film has a function as a solid electrolyte film. However, the proton conductivity tends to increase as the ratio of X substituted with H (hereinafter referred to as proton substitution rate) increases. That is, it is preferable that the proton substitution rate is high in proton substitution for producing a solid electrolyte film from a precursor film.

As solid electrolyte, what has the following various performance is preferable. The ionic conductivity is preferably 0.005 S / cm or more, and more preferably 0.01 S / cm or more, for example, at 25 ° C. and a relative humidity of 70%. Further, the ionic conductivity after being immersed in a 64% by weight aqueous methanol solution at 18 ° C. for one day is preferably 0.003 S / cm or more, more preferably 0.008 S / cm or more, particularly before immersion. What the fall rate of the ionic conductivity after immersion with respect to 20% or less is preferable. The methanol diffusion coefficient is preferably 4 × 10 ⁻⁷ cm ² / s or less, and particularly preferably 2 × 10 ⁻⁷ cm ² / s or less.

  As for strength, those having an elastic modulus of 10 MPa or more are preferred, and those having a modulus of 20 MPa or more are particularly preferred. The method for measuring the elastic modulus is described in detail in paragraph [0138] of JP-A-2005-104148, and the above value of the elastic modulus is a value obtained by a tensile tester manufactured by Toyo Baldwin. Therefore, when obtaining the elastic modulus using another test method or tester, it is preferable to obtain the correlation with the value obtained by the test method or tester in advance.

  As for durability, it is preferable that each change rate of weight, ion exchange capacity, and methanol diffusion coefficient is 20% or less before and after a time-lapse test immersed in a 64 wt% methanol aqueous solution at a constant temperature, and 15% The following are particularly preferred. Further, before and after the time-lapse test in hydrogen peroxide, the rate of change in weight, ion exchange capacity, and methanol diffusion coefficient is preferably 20% or less, and particularly preferably 10% or less. Further, in a 64 wt% aqueous methanol solution, the volume swelling rate at a constant temperature is preferably 10% or less, and particularly preferably 5% or less.

  Further, those having a stable water absorption and water content are preferred. Moreover, it is preferable that it is so small that solubility is substantially negligible with respect to alcohols, water, and a mixed solvent of alcohol and water. Further, it is preferable that the weight loss and the shape change when immersed in the liquid are small enough to be substantially ignored.

  The ionic conduction performance of the solid electrolyte film is expressed by a so-called index which is a ratio between the ionic conductivity and the methanol permeability coefficient. And it can be said that the larger the index in a certain direction, the higher the ion conduction performance in that direction. In the thickness direction of the solid electrolyte film, the ionic conductivity is proportional to the thickness, and the methanol permeability coefficient is inversely proportional to the thickness. Therefore, the ionic conductivity of the solid electrolyte film can be controlled by changing the thickness. In a solid electrolyte film used for a fuel cell, an anode electrode is provided on one side and a cathode electrode is provided on the other side. Therefore, the index in the thickness direction of the solid electrolyte film is larger than the index in the other direction. Is preferred. The thickness of the solid electrolyte film is preferably 10 to 300 μm. For example, in the case of a solid electrolyte having both high ionic conductivity and methanol diffusion coefficient, it is particularly preferable to produce a film having a thickness of 50 to 200 μm, and a solid having both low ionic conductivity and methanol diffusion coefficient. In the case of an electrolyte, it is particularly preferable to produce a film so that the thickness is 20 to 100 μm.

  The heat resistant temperature is preferably 200 ° C. or higher, more preferably 250 ° C. or higher, and particularly preferably 300 ° C. or higher. The heat-resistant temperature here means a temperature when heating is performed at a heating rate of 1 ° C./min and weight loss reaches 5%. Note that this weight reduction is calculated excluding the amount of evaporation such as moisture.

Furthermore, when a solid electrolyte is used as a film for a fuel cell, the solid electrolyte is preferably a solid electrolyte having a maximum output density of 10 mW / cm ² or more.

  By using the polymer which is the precursor of the above solid electrolyte, a dope suitable for the production of the precursor film can be produced. Moreover, the solid electrolyte film suitable as a fuel cell can be manufactured by carrying out proton substitution using this precursor film. The solution suitable for the production of the precursor film is, for example, a solution having a relatively low viscosity and easily removing foreign matters by filtration.

  The dope solvent may be an organic compound that can dissolve the polymer that is the precursor of the solid electrolyte. Examples include aromatic hydrocarbons (eg, benzene, toluene, etc.), halogenated hydrocarbons (eg, dichloromethane, chlorobenzene, etc.), alcohols (eg, methanol, ethanol, n-propanol, n-butanol, diethylene glycol, etc.), Ketones (eg, acetone, methyl ethyl ketone, etc.), esters (eg, methyl acetate, ethyl acetate, propyl acetate, etc.), ethers (eg, tetrahydrofuran, methyl cellosolve, etc.), and nitrogen-containing compounds (N-methylpyrrolidone (NMP)) N, N-dimethylformamide (DMF), N, N′-dimethylacetamide (DMAc) and the like), dimethyl sulfoxide (DMSO) and the like.

  The dope solvent may be a mixture of a plurality of substances. When the solvent is a mixture, it is preferable to use a mixture of a good solvent and a poor solvent for the polymer. In the case of producing a precursor film having the structure of Chemical Formula 3, it is preferable to use a mixture of a good solvent and a poor solvent of a polymer as a solvent. Mixing the solvent and polymer so that the polymer is 5% by weight of the total weight, it is possible to determine whether the solvent used is a poor solvent or a good solvent of the polymer, depending on the presence or absence of insoluble matter it can. The good solvent of the polymer, that is, the substance that dissolves the polymer, has a relatively high boiling point among the compounds generally used as the solvent, while the poor solvent has a comparative boiling point among the compounds generally used as the solvent. The lower one. Therefore, by mixing the poor solvent with the good solvent, the efficiency and effect of removing the solvent in the film production process can be enhanced, and in particular, the drying efficiency of the cast film can be greatly improved.

  In a mixture of a good solvent and a poor solvent, the weight ratio of the poor solvent is preferably as large as possible, specifically 10% or more and less than 100%. More preferably, (weight of good solvent) :( weight of poor solvent) is 90:10 to 10:90. Thereby, since the ratio of the low boiling-point component in the weight of all the solvents becomes large, the drying efficiency and the drying effect in the manufacturing process of a solid electrolyte film can be improved more.

  As the good solvent component, DMF, DMAc, DMSO, and NMP are preferable. Among them, DMSO is particularly preferable in terms of safety and relatively low boiling point. As the poor solvent component, a so-called lower alcohol having 1 to 5 carbon atoms, methyl acetate, and acetone are preferable. Among them, a lower alcohol having 1 to 3 carbon atoms is more preferable, and when DMSO is used as a good solvent. Methyl alcohol is particularly preferred from the viewpoint of the most excellent compatibility with it.

  In order to improve various properties of the solid electrolyte film, an additive can be added to the dope. Examples of the additive include an antioxidant, fibers, fine particles, a water absorbing agent, a plasticizer, and a compatibilizer. The addition rate of these additives is preferably in the range of 1% by weight to 30% by weight when the total solid content in the dope is 100% by weight. However, the addition rate and the type of substance do not adversely affect proton conductivity. The additive will be specifically described below.

  Antioxidants include (hindered) phenolic, monovalent or divalent sulfur, trivalent phosphorus, benzophenone, benzotriazole, hindered amine, cyanoacrylate, salicylate, oxalic acid anilide These compounds are listed as preferred examples. Specific examples thereof include compounds described in JP-A-8-53614, JP-A-10-101873, JP-A-11-114430, and JP-A-2003-151346.

  Preferred examples of the fibers include perfluorocarbon fibers, cellulose fibers, glass fibers, polyethylene fibers, and the like, and specifically, JP-A-10-31815, JP-A-2000-231938, JP-A-2001-307545. And fibers described in JP-A Nos. 2003-317748, 2004-63430, and 2004-107461.

  Examples of the fine particles include titanium oxide, zirconium oxide, and the like. Specific examples include various fine particles described in JP-A Nos. 2003-178777 and 2004-217931.

  Water-absorbing agents, that is, hydrophilic substances include cross-linked polyacrylate, starch-acrylate, poval, polyacrylonitrile, carboxymethylcellulose, polyvinylpyrrolidone, polyglycol dialkyl ether, polyglycol dialkyl ester, synthetic zeolite, titania gel, zirconia gel And yttria gel are preferable examples. Specific examples include water absorbing agents described in JP-A Nos. 7-135033, 8-20716, and 9351857.

  Preferred examples of the plasticizer include phosphate ester compounds, chlorinated paraffins, alkylnaphthalene compounds, sulfone alkylamide compounds, oligoethers, and aromatic nitriles. Examples thereof include plasticizers described in JP-A Nos. 288916 and 2003-317539.

  As the compatibilizer, those having a boiling point or sublimation point of 250 ° C. or higher are preferable, and those having a boiling point or 300 ° C. or higher are more preferable.

  The dope may further contain various polymers different from the precursor for the purpose of (1) increasing the mechanical strength of the film and (2) increasing the acid concentration in the solid electrolyte film.

  Among the above objects, a polymer having a molecular weight of about 10,000 to 1,000,000 and having good compatibility with the precursor is suitable for (1). For example, perfluorinated polymers, polystyrene, polyethylene glycol, polyoxetane, polyether ketone, polyether sulfone, and polymers containing two or more polymer repeating units are preferred. Moreover, it is preferable to contain these substances in dope so that it may become the range of 1-30 weight% with respect to the total weight when it is set as a film. In addition, you may improve compatibility with a precursor by using a compatibilizer. As the compatibilizer, those having a boiling point or sublimation point of 250 ° C. or higher are preferable, and those having a boiling point of 300 ° C. or higher are more preferable.

  Among the above objects, (2) is preferably a polymer having a proton acid site. Examples of such a polymer include perfluorosulfonic acid polymers such as Nafion (registered trademark), sulfonated polyetheretherketone having a phosphate group in the side chain, sulfonated polyethersulfone, sulfonated polysulfone, and sulfonated polybenzimidazole. Examples thereof include sulfonated products of heat-resistant aromatic polymer compounds such as Moreover, it is preferable to contain these substances in dope so that it may become the range of 1-30 weight% with respect to the total weight when it is set as a film.

  Furthermore, when the obtained solid electrolyte film is used in a fuel cell, an active metal catalyst that promotes the redox reaction between the anode fuel and the cathode fuel may be added to the dope. As a result, the fuel that has permeated into the solid electrolyte film from one electrode is consumed in the solid electrolyte without reaching the other electrode, so that the crossover phenomenon can be prevented. The active metal catalyst is not particularly limited as long as it functions as an electrode catalyst, but platinum or an alloy based on platinum is particularly suitable.

[Dope production]
Below, dope used for manufacture of the film of this invention is demonstrated. FIG. 1 shows a dope manufacturing facility according to the present invention. However, the present invention is not limited to the dope manufacturing apparatus and method shown here.

  The dope manufacturing facility 10 includes a solvent tank 11 for storing the solvent 11a, a hopper 12 for supplying the precursor 12a, an additive tank 15 for storing the additive, a solvent 11a and the precursor 12a, A mixing tank 17 that mixes the additive into the mixed solution 16, a heating device 18 that heats the mixed solution 16, a temperature regulator 21 that adjusts the temperature of the heated mixed solution 16, and a temperature A first filtration device 22 that filters the mixed solution 16 exiting the regulator 21 to form a dope 24, a flash device 26 for adjusting the concentration of the dope 24, and a first filter for filtering the concentration-adjusted dope 24. 2 filtration device 27. Further, the dope manufacturing facility 10 is provided with a recovery device 28 for recovering the solvent that volatilizes in the flash device 26 and a regeneration device 29 for regenerating the recovered solvent. The dope manufacturing facility 10 is connected to a film manufacturing facility 33 via a stock tank 32. In addition, although the valves 36-38 for adjusting the amount of liquid feeding and the pumps 41 and 42 for liquid feeding are provided in the dope manufacturing equipment 10, about the increase / decrease in the position and number where these are arrange | positioned It is changed appropriately.

  The process of manufacturing the dope 24 using the dope manufacturing facility 10 will be described below. By opening the valve 37, the solvent 11 a is sent from the solvent tank 11 to the mixing tank 17. Next, the precursor 12 a is sent from the hopper 12 to the mixing tank 17. At this time, the precursor 12a may be continuously fed to the mixing tank 17 by a sending unit that continuously measures and feeds, or the mixing tank 17 is fed by a sending unit that measures and sends a predetermined amount. May be sent intermittently. In addition, the required amount of the additive solution is sent from the additive tank 15 to the mixing tank 17 by opening and closing the valve 36.

  In addition to the method of sending the additive as a solution, for example, when the additive is liquid at room temperature, the additive can be fed into the mixing tank 17 in the liquid state. Further, when the additive is solid, a method of feeding into the mixing tank 17 using a hopper or the like is also possible. When a plurality of types of additives are added, a solution in which a plurality of types of additives are dissolved can be placed in the additive tank 15. Alternatively, it is also possible to use a plurality of additive tanks and put a solution in which the additive is dissolved in each of them and send them to the mixing tank 17 through independent pipes.

  In the above description, the order of putting in the mixing tank 17 is the solvent 11a, the precursor 12a, and the additive, but is not limited to this order. For example, after the precursor 12a is fed into the mixing tank 17, a preferable amount of the solvent 11a can be fed. In addition, the additive is not necessarily limited to mixing the precursor 12a and the solvent 11a in the mixing tank 17, and may be mixed in a mixture of the precursor 12a and the solvent 11a by an in-line mixing method or the like in a later step.

  The mixing tank 17 encloses the outer surface thereof, a jacket 46 supplied with a heat transfer medium between the mixing tank 17, a first stirrer 48 rotated by a motor 47, and a second stirrer 52 rotated by a motor 51, It has. The mixing tank 17 supplies the heat transfer medium to the inside of the jacket 46 and circulates it to adjust the temperature inside. The internal temperature of the mixing tank 17 is preferably in the range of −10 ° C. to 55 ° C. By appropriately selecting and using the types of the first stirrer 48 and the second stirrer 52, the mixed liquid 16 in which the precursor 12a is swollen with the solvent 11a is obtained. The first stirrer 48 preferably has an anchor blade, and the second stirrer 52 is preferably a dissolver type eccentric stirrer.

  Next, the liquid mixture 16 is sent to the heating device 18 by the pump 41. The heating device 18 is preferably a jacketed tube having a tube body (not shown) and a jacket (not shown) for passing a heat transfer medium between the tube body, and further, the mixed liquid 16 is added. It is preferable to have a pressurizing part (not shown) for pressing. By using such a heating device 18, the solid content in the mixed solution 16 can be effectively and efficiently dissolved under heating conditions or pressure heating conditions. Hereinafter, this method of dissolving the solid component in the solvent 11a by heating is referred to as a heating dissolution method. In the heating dissolution method, it is preferable to heat the mixed solution 16 so as to be 60 ° C to 250 ° C.

  Note that the solid component may be dissolved in the solvent 11a by a cooling dissolution method instead of the heating dissolution method. The cooling dissolution method is a method of proceeding dissolution while cooling the mixed solution 16 so that the temperature of the mixed solution 16 is maintained or lower. In the cooling dissolution method, the mixed solution 16 is preferably cooled to a temperature of −100 ° C. to −10 ° C. The precursor 12a can be sufficiently dissolved in the solvent 11a by the heating dissolution method or the cooling dissolution method as described above.

  After the liquid mixture 16 is brought to about room temperature by the temperature controller 21, it is filtered by the first filtration device 22 to remove foreign matters such as impurities and aggregates, thereby obtaining a dope 24. The filter used in the first filtration device 22 preferably has an average pore diameter of 10 μm or less.

  The dope 24 after filtration is sent to the stock tank 32 by the valve 38 and temporarily stored, and then used for film production.

  By the way, as described above, the method in which the solid component is once swollen and then dissolved to form a solution increases the time required for the dope production as the concentration of the precursor 12a in the solution increases. May be problematic in terms. In such a case, it is preferable to once make a dope having a concentration lower than the target concentration and then carry out a concentration step to achieve the target concentration. For example, the dope 24 filtered by the first filtration device 22 can be sent to the flash device 26 by the valve 38, and the dope 24 can be concentrated by evaporating a part of the solvent 11 a of the dope 24. . The concentrated dope 24 is extracted from the flash device 26 by the pump 42 and sent to the second filtration device 27. The temperature of the dope 24 during filtration is preferably 0 ° C to 200 ° C. The dope 24 from which foreign matter has been removed by the second filtration device 27 is sent to the stock tank 32 and once stored, and then used for film production. In addition, since the concentrated dope 24 may contain bubbles, it is preferable to perform a bubble removal process before sending it to the second filtration device 27. As the bubble removal method, for example, various known methods such as an ultrasonic irradiation method for irradiating the dope 24 with ultrasonic waves are applied.

  Further, the solvent gas generated by the flash evaporation in the flash device 26 is condensed by the recovery device 28 having a condenser (not shown) and recovered as a liquid. The recovered solvent is regenerated and reused as a solvent for dope production by the regenerator 29. Such recovery and recycling have an advantage in terms of manufacturing cost, and since the manufacturing process of the dope 24 is performed in a closed system, there is an effect of preventing adverse effects on the human body and the environment.

  In addition, when impurities such as coarse particles or foreign matters are contained in the dope 24, when the dope 24 is used as a solid electrolyte film, the proton conductivity of the solid electrolyte film decreases, or the solid electrolyte film itself May deteriorate. Therefore, it is preferable to filter the dope 24 by using a filtering device at least once in the course of manufacturing the dope 24. In addition, the installation number and installation location of the filtration apparatus in the dope manufacturing facility 10 and the frequency | count of filtering dope are not specifically limited, What is necessary is just to determine as needed.

  By the above manufacturing method, the dope 24 in which the concentration of the precursor 12a is 5% by weight or more and 50% by weight or less with respect to the total weight can be manufactured. More preferably, the concentration of the precursor 12a of the dope 24 is in the range of 10 wt% to 40 wt% with respect to the total weight. Further, the concentration of the additive is preferably in the range of 1% by weight to 30% by weight when the entire solid content in the dope is 100% by weight. In the dope 24, whether the solid content is dissolved in the solvent 11 a can be confirmed by illuminating the filtered dope 24 with a fluorescent lamp.

[Solid electrolyte film manufacturing process]
Next, the manufacturing method of the solid electrolyte film of this invention is demonstrated. In FIG. 2, the flow of the solid electrolyte film manufacturing process 60 which concerns on this invention is shown. In FIG. 2, only the flow of the process will be described briefly, and details of each process will be described with reference to FIG. In the following description, the solid electrolyte film may be referred to as a film.

  The solid electrolyte film manufacturing process 60 includes a casting film forming process 63 for forming the casting film 61 from the dope 24, an immersing process 64 for immersing the formed casting film 61 in the liquid, and a casting film 61 from the support. A hydrogen-replacement film 65a, which is brought into contact with a stripping process 66 to be peeled off to form a precursor film 65, a first drying process 67 for drying the precursor film 65, and a liquid precursor film 65 containing an acid as a proton donor. An acid treatment step 68, a water washing step 69 for washing the hydrogen-substituted film 65a that has undergone the acid treatment step 68, and a second drying step 72 that dries the washed hydrogen-substituted film 65a to form a solid electrolyte film 70. Have.

  In the cast film forming step 63, the dope is cast on the support to form the cast film 61. The support is wound around the drive roller and travels endlessly, and the casting film 61 moves with the travel of the support until it is stripped off as the precursor film 65 in the stripping step 63.

  In the dipping process 64, the casting film 61 on the support is dipped in a liquid (hereinafter referred to as dipping liquid). By this immersion step 64, a part of the solvent contained in the casting film 61 and the immersion liquid are replaced (hereinafter referred to as solvent replacement), and the amount of the solvent remaining in the casting film 61 is reduced. Then, by performing this solvent substitution until the amount of the solvent becomes a certain amount or less, the casting film 61 can exhibit self-supporting properties. Subsequently, in the stripping step 66, the casting film 61 having self-supporting properties is stripped from the support to obtain a precursor film 65. The stripping step 66 may be performed while the casting film 61 is immersed in the immersion liquid, or may be performed after the casting film 61 is taken out from the immersion liquid. Further, instead of the dipping step 64, the cast film 61 is made to have a self-supporting property by applying a dry wind to the cast film 61 in the cast film forming step 63, and the cast film is peeled off. It may be a body film.

  In the first drying step 67, the precursor film 65 is dried by a drying means. Any drying means may be used as long as the precursor film 65 can be dried. For example, a tenter that includes a drying device and a number of gripping means (for example, clips) and promotes drying while transporting the gripping means while fixing both side ends of the precursor film 65 can be cited. Adopted. Further, it is preferable to drain the surface of the precursor film 65 with an air knife or the like before drying the precursor film 65 with a tenter. The tenter will be described later.

  In the acid treatment step 68, the first liquid 300 containing acid is brought into contact with one surface 301 of the precursor film 65 that has been subjected to the drying treatment, using a contact means. The first liquid 300 may be formed on any one surface of the precursor film 65. By the contact of the precursor film 65 and the first liquid 300, the precursor contained in the precursor film 65 is proton-substituted to become a solid electrolyte. That is, in this acid treatment step 68, a hydrogen substitution film 65 a is generated from the precursor film 65.

  In the water washing step 69, the hydrogen replacement film 65a after the acid treatment and the cleaning liquid are brought into contact with each other to remove the excess first liquid 300 attached to the surface of the hydrogen replacement film 65a or included in the hydrogen replacement film 65a. . This washing step 69 can also prevent the polymer or the like constituting the hydrogen-substituted film 65a from being contaminated with acid.

  In addition, by performing the acid treatment step 68 and the water washing step 69 as described above, an effect of removing impurities such as inorganic salts in the solid electrolyte contained in the hydrogen-substituted film 65a can also be obtained, so the film to be manufactured The deterioration of 70 can also be prevented. In addition, it is preferable that content of the metal contained in the hydrogen substitution film 65a after the water washing process 69 is 1000 ppm or less by performing the acid treatment process 68 and the water washing process 69, More preferably, it is 100 ppm or less. Examples of the metal include Na, K, Ca, Fe, Ni, Cr, and Zn. The content of these metals can be grasped by, for example, measuring with a commercially available atomic absorption photometer.

  In the second drying step 72, the hydrogen substitution film 65a is dried again by a drying means. Usually, since the water film can be sufficiently removed with a draining means such as an air knife, a drying step is not necessary, but before winding the transparent resin film into a roll, it is heated and dried to adjust to a preferred moisture content, Conversely, the humidity can be adjusted with wind having a set humidity. Thereby, the solid electrolyte film 70 which expresses the outstanding proton conductivity can be obtained.

  Next, the details of the dipping process 64, the stripping process 66, the acid treatment process 68, and the water washing process 69 will be described.

In the dipping process 64, the precursor film exhibits self-supporting properties by dipping the casting film 61 in the dipping solution. Factors that cause the precursor film to exhibit self-supporting properties are as follows.
(1) The amount of residual solvent is reduced by replacing water with a part of the solvent contained in the casting film 61. (2) The precursor film 65 is solidified by being immersed in water which is a poor solvent for the precursor.
Thus, in the stripping step 66, the casting film 61 having self-supporting property can be easily stripped as the precursor film 65, and at the same time, the residual solvent of the precursor film 65 in the subsequent first drying step 67 is removed. Can be removed.

  This immersion liquid has a boiling point lower than that of the solvent 11a and may be a poor solvent with respect to the precursor 12a. Moreover, you may perform this immersion process in multiple times. When performing an immersion process in multiple times, it is preferable to select the immersion liquid of each process so that a boiling point may become low as it becomes a subsequent immersion process. Since it becomes possible to reduce the boiling point of the residual solvent contained in the precursor film by this multiple dipping process, the drying process performed after the dipping process can be facilitated.

  The immersion liquid preferably has a lower boiling point than the solvent contained in the cast film 61 and is a good organic solvent. When the casting film 61 is immersed in such an immersion liquid, the speed at which the organic solvent contained in the casting film 61 is extracted is improved, and the organic solvent remaining on the casting film 61 in the subsequent drying step is removed. It becomes easy to do. It is preferable to use pure water as the immersion liquid.

  In addition, the method of solvent replacement of the casting film 61 is not limited to the method of immersing the casting film 61 in the immersion liquid. For example, a method of bringing the immersion film into contact with the casting film 61 may be used. Specific examples of the method for bringing the immersion liquid into contact include a method of spraying or applying the immersion liquid to the casting film 61 on the support.

  As a contact method between the first liquid 300 and the one side 301 of the precursor film 65 in the acid treatment step 68, (1) the first liquid 300 can be uniformly contacted with the precursor film 65 (2) on the one side 301 A method that satisfies the requirement that the amount of the first liquid 300 in contact with the first liquid 300 is easy is preferable. As the contact system, a die coater such as extrusion or slide, a roll coater such as a forward roll, a reverse roll or a gravure, a rod coater wound with a thin metal wire, or the like can be preferably used. These coating methods are summarized in Modern Coating and Drying Technology, Edward Cohen and Edgar B. Gutoff, Edits., VCH Publishers, Inc, 1992. Since the first liquid 300 to be applied is then removed by washing with water, it is desirable to suppress the application amount as much as possible when considering waste liquid treatment for environmental protection. From this viewpoint, a rod coater, a gravure coater, and a blade coater that can be stably operated even in a small coating amount region can be preferably used.

  The first liquid 300 is not limited to an acidic aqueous solution, and any liquid that can give protons to the precursor proton acceptor in proton substitution may be used. For example, when the acid is ionized into an anion and a proton, an acid having a higher proton acceptability than the anion may be used as the precursor.

  Moreover, as an acid contained in the 1st liquid 300, a sulfuric acid, phosphoric acid, nitric acid, organic sulfonic acid etc. can be used, for example. Among the acids listed above, when an acid having an anion formula weight of 40 or more and 1000 or less is used, an anion that inhibits proton substitution is less likely to enter the precursor film 65, so that highly efficient proton substitution is performed. Can do. Specific examples include sulfuric acid, phosphoric acid, and nitric acid. Among them, it is preferable to use sulfuric acid having a large anion formula weight.

  As the 1st liquid 300, what dissolved the acid in the liquid which mixed the acid mentioned above into water or an organic solvent, and water can be used. Pure water is used as the water used in the present invention. The pure water used in the present invention has a specific electric resistance of at least 1 MΩ or more, particularly metal ions such as sodium, potassium, magnesium and calcium are less than 1 ppm, and anions such as chloro and nitric acid are less than 0.1 ppm. Pure water can be easily obtained by a simple substance such as a reverse osmosis membrane, an ion exchange resin, distillation, or a combination thereof.

  The organic solvent used in the present invention may be one kind or a combination of two or more kinds, but it is necessary to select one that does not dissolve or swell the precursor film 65. Examples of the organic solvent used in the present invention include New Edition Solvent Pocket Book (Ohm, published in 1994), but the present invention is not limited thereto. For example, alcohols (methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, cyclohexanol, benzyl alcohol, fluorinated alcohol), ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone), esters (methyl acetate, Ethyl acetate, butyl acetate), polyhydric alcohols (ethylene glycol, diethylene glycol, propylene glycol, ethylene glycol diethyl ether), N, N-dimethylformamide, perfluorotributylamine, triethylamine, dimethylformamide, dimethyl sulfoxide, methyl cellosolve, etc. Is mentioned.

  The concentration of protons contained in the first liquid 300 (hereinafter referred to as proton concentration) is 0.05 mol / l or more. When the proton concentration of the first liquid 300 is less than 0.05 mol / l, the proton substitution in the precursor film 65 is not sufficiently performed, which is not preferable. The proton concentration is a concept representing the normality conventionally used, and the proton concentration of the first liquid represents the concentration of hydrogen atoms contained in the first liquid 300 and capable of becoming protons.

  In proton substitution, proton substitution is promoted as the temperature of one surface 301 of the precursor film 65 increases. In particular, in the vicinity of the glass transition temperature Tg of the precursor film 65, the proton substitution reaction rate is the highest. Therefore, (1) the precursor film 65 in the acid treatment step 68 is heated (2) the first liquid 300 maintained at a desired temperature is brought into contact with the precursor film 65, or these methods By combining the methods, the time required for proton substitution in the acid treatment step 68 can be shortened.

  In the present invention, the temperature of the first liquid 300 is preferably equal to the temperature at which the reaction is desired (= the glass transition temperature Tg of the precursor film 65). However, depending on the type of the first liquid 300 used, the Tg is the first liquid. The boiling point of 300 may be exceeded. In order to perform stable coating, the temperature is set to be lower than the boiling point of the first liquid 300, preferably less than 90% of the boiling point (° C.), more preferably less than 80% of the boiling point (° C.). In consideration of the environment in which the film production line is installed, the temperature of the first liquid 300 is preferably room temperature or higher, and more preferably adjusted to 30 degrees or higher.

  In the acid treatment step 68, as a heating means for the one surface 301 of the precursor film 65a, collision of hot air with the one surface 301, contact heat transfer with a heating roll, induction heating with a microwave, radiant heat heating with an infrared heater, or the like can be preferably used. In particular, the infrared heater is preferable because it can be performed without contact and without the flow of air, so that the influence on the one surface 301 coated with the first liquid 300 can be minimized. As the type of the infrared heater, for example, various far infrared ceramic heaters such as electric type, gas type, oil type and steam type manufactured by Noritake Company Limited can be used. In particular, the oil type and the steam type in which the heat medium uses oil or steam are preferable from the viewpoint of explosion prevention in an atmosphere in which an organic solvent coexists. The temperature of the hydrogen substitution film 65a is 25 ° C. or higher and lower than 150 ° C., preferably 25 ° C. or higher and lower than 100 ° C., more preferably 40 ° C. or higher and lower than 80 ° C. For the detection of the film temperature, a commercially available non-contact infrared thermometer can be used. In order to control the temperature within the above temperature range, feedback control may be performed on the heating means.

  In this acid treatment step 68, in order to perform high-efficiency proton substitution on the precursor film 65, the residual solvent amount of the precursor film 65 is 1% by weight or more and 100% by weight or less based on the dry weight standard. Is preferred. If the residual solvent amount advances to 1% by weight or less with respect to the dry weight standard, the drying time becomes longer, which is not preferable, and the precursor film 65 having the residual solvent amount of 100% by weight or more with respect to the dry weight standard is acid-treated. If this is performed, the porosity of the film increases, which is not preferable. The amount of residual solvent based on the dry amount is a value calculated by {(xy) / y} × 100, where x is the film weight at the time of sampling and y is the weight after the sampling film is dried. It is.

  In the acid treatment step 68, the ratio of the precursor of the precursor film 65 substituted with protons (hereinafter referred to as proton substitution rate) is preferably 80 mol% or more, and the proton substitution rate is 90 mol% or more. More preferably. By performing proton substitution with such a high proton substitution rate, an excellent proton conductive solid electrolyte film 70 can be manufactured.

  In consideration of carrying out the hydrogen replacement film 65a while continuously transporting the hydrogen replacement film 65a in the water washing step 69, a method of applying the cleaning liquid, a method of spraying the cleaning liquid, a hydrogen replacement film in a container containing the cleaning liquid The method of immersing the whole 65a is mentioned, and any of these methods may be used.

The amount of the cleaning solution used for washing with water must be at least an amount exceeding the theoretical dilution rate defined below.
Theoretical dilution factor = application amount of cleaning liquid [ml / m ² ] ÷ application amount of first liquid 300 [ml / m ² ]
That is, the theoretical dilution ratio is defined on the assumption that all of the cleaning liquid used for the water washing contributed to the dilution and mixing of the first liquid 300. Actually, since complete mixing does not occur, a cleaning liquid amount exceeding the theoretical dilution rate is used. Although it depends on the proton concentration of the first liquid used, the secondary additives, and the type of solvent, it is a cleaning liquid that can be diluted at least 100 to 1000 times, preferably 500 to 10,000 times, more preferably 1000 to 100,000 times. Is used.

  In the case of using a certain amount of cleaning liquid, the water-washing method is preferably a batch-type cleaning method in which it is divided and applied several times, rather than being applied all at once. That is, the amount of the cleaning liquid is divided into several parts and supplied to a plurality of water washing means installed in tandem in the transport direction of the hydrogen substitution film 65a. An appropriate time (distance) is provided between one water washing means and the next water washing means, and the first liquid 300 is diluted by diffusion. More preferably, if the cleaning liquid on the film flows along the film surface by providing an inclination to the transferred hydrogen substitution film 65a, mixed dilution by flow can be obtained in addition to diffusion. As a most preferable method, the water washing dilution efficiency can be further improved by providing a water draining means for removing the film of the cleaning liquid on the hydrogen substitution film 65a between the water washing means and the water washing means. Specific examples of draining means include a blade used in a blade coater, an air knife used in an air knife coater, a rod used in a rod coater, and a roll used in a roll coater. Although it is advantageous that the number of water washing means arranged in such a tandem is large, 2 to 10 stages, preferably 2 to 5 stages are usually used from the viewpoint of installation space and equipment cost.

  The thickness of the cleaning liquid film (hereinafter referred to as the water film) after the draining means is preferably thin, but the thickness of the water film remaining on the hydrogen-substituted film 65a differs depending on the type of the cutting means used. In the method of physically bringing a solid into contact with the hydrogen-substituted film 65a, such as a blade, a rod, or a roll, even if the solid is an elastic body with low hardness such as rubber, the surface of the hydrogen-substituted film 65a is scratched. It is necessary to leave a finite water film as a lubricating fluid because the elastic body is worn away. Usually, a water film of several μm or more, preferably 10 μm or more is left as a lubricating fluid.

  An air knife is preferably used as a draining means that can reduce the thickness of the water film to the limit. By setting a sufficient air volume and pressure, the water film thickness can be brought close to zero. However, if the amount of air blown from the air knife is too large, it may affect the transport stability of the hydrogen-substituted film 65a, such as flapping and deviation, so there is a preferable range. Although depending on the original water film thickness on the hydrogen substitution film 65a and the transport speed of the hydrogen substitution film 65a, the wind speed is usually 10 to 500 m / sec, preferably 20 to 300 m / sec, more preferably 30 to 200 m / sec. Is used. In order to uniformly remove the water film, the air supply to the air knife outlet and the air knife is set so that the wind speed distribution in the width direction of the hydrogen-substituted film 65a is usually within 10%, preferably within 5%. Adjust the method. As the gap between the surface of the transparent resin film to be conveyed and the air knife outlet becomes narrower, the draining ability increases. However, the possibility of being damaged by contact with the hydrogen-substituted film 65a increases, so there is an appropriate range. Usually, an air knife is installed with a gap of 10 μm to 10 cm, preferably 100 μm to 5 cm, more preferably 500 μm to 1 cm. Furthermore, by setting a backup roll on the opposite side of the water-washing surface of the hydrogen replacement film 65a so as to face the air knife, the setting of the gap is stabilized and the influence of fluttering, wrinkles, deformation, etc. of the hydrogen replacement film 65a is stabilized. It is preferable because it can be relaxed.

  It is preferable to use pure water as the cleaning liquid. In order to obtain a high effect of washing out the acid, the temperature of the cleaning liquid used is preferably 30 ° C. or higher and the boiling point of the cleaning liquid or lower. However, the temperature of the cleaning liquid is not particularly limited as long as it is in a temperature range from approximately room temperature to boiling.

[Solid electrolyte film manufacturing equipment]
FIG. 3 shows a film manufacturing facility 33 used in this embodiment. The film manufacturing facility 33 is a facility designed based on the solid electrolyte film manufacturing process 60. However, this film manufacturing equipment 33 is an example of the present invention and does not limit the present invention.

  The film production facility 33 includes a casting chamber 80 for casting the dope 24 on a support to form a casting film 61, and a drying means while the casting film 61 is transported as the support travels. A transport chamber 81 for drying the film 61, a tenter 83 for accelerating the drying of the precursor film 65 after peeling off the casting film 61 from the support to obtain the precursor film 65, and further drying the precursor film 65 Is provided with a drying chamber 84 for making the film 70, a humidity control chamber 85 for adjusting the humidity of the film 70, and a winding chamber 86 for winding the film 70 after the humidity control into a roll shape. Further, an acid treatment chamber 88 is disposed between the ear clip device 105 and the drying chamber 84.

  The film manufacturing facility 33 is connected to the dope manufacturing facility 10 via the stock tank 32. The stock tank 32 is provided with a stirrer 91 that is rotated by a motor 90. The dope 24 prepared in the dope manufacturing facility 10 is stored in the stock tank 32. Since the stirrer 91 is always rotating, it is possible to keep the dope 24 in a uniform state by suppressing the precipitation and aggregation of solids in the dope 24. In addition, when the dope 24 is stirred in this way, various additives can be appropriately mixed with the dope 24.

The casting chamber 80 includes a casting die 93 that flows out of the dope 24, and a casting band 94 that is a traveling support. As a material of the casting die 93, precipitation hardening type stainless steel is preferable, and its thermal expansion coefficient is preferably 2 × 10 ⁻⁵ (° C. ⁻¹ ) or less. And it has almost the same corrosion resistance as SUS316 in the forced corrosion test with electrolyte aqueous solution, and even if it is immersed in a mixed solution of dichloromethane, methanol and water for 3 months, pitting (opening) occurs at the gas-liquid interface. Those having corrosion resistance that do not occur are preferred. The casting die 93 is preferably produced by grinding a material that has passed for one month or more after casting. As a result, the dope 24 flows uniformly in the casting die 93, and a flow described later. It is possible to prevent streaks or the like from occurring in the spread film 61. The so-called wetted surface that is in contact with the dope 24 of the casting die 93 preferably has a finishing accuracy of 1 μm or less in terms of surface roughness and a straightness of 1 μm / m or less in any direction. The slit clearance of the casting die 93 can be adjusted in the range of 0.5 mm to 3.5 mm by automatic adjustment. The chamfer radius R of the corner portion of the liquid contact portion at the tip of the lip of the casting die 93 is constant and 50 μm or less over the entire width of the casting die 93. The casting die 93 is preferably a coat hanger type die.

  The width of the casting die 93 is not particularly limited, but is preferably about 1.1 to 2.0 times the width of the film 70 as the final product. In addition, a temperature controller that controls the temperature of the casting die 93 is preferably attached to the casting die 93 so that the temperature of the dope 24 during film formation is maintained at a predetermined temperature. Furthermore, it is more preferable that the casting die 93 is provided with a plurality of thickness adjusting bolts (heat bolts) provided at predetermined intervals in the width direction and an automatic thickness adjusting mechanism that adjusts the gap between the slits with the heat bolt. . The heat bolt is preferably subjected to film formation by setting a profile according to the amount of pump 95 (preferably a high precision gear pump) according to a preset program. In order to precisely control the dope feeding amount, the pump 95 is preferably a high-precision gear pump. In addition, a thickness measuring machine such as an infrared thickness gauge is provided in the film manufacturing facility 33, and feedback control to the automatic thickness adjusting mechanism is performed by an adjustment program based on the thickness profile and a detection result by the thickness measuring machine. Also good. It is preferable to use a casting die 93 that can adjust the slit interval of the tip lip to be ± 50 μm or less so that the difference in thickness at any two positions excluding both ends of the film 70 as a product is within 1 μm.

It is more preferable that a cured film is formed at the lip end of the casting die 93. The method for forming the cured film is not particularly limited, and examples thereof include ceramic coating, hard chrome plating, and a nitriding method. In the case of using ceramics as the cured film, it is preferable to use a ceramic that can be ground, has a low porosity, is not brittle, has good corrosion resistance, and has no affinity or adhesion to the dope 24. Specific examples include tungsten carbide (WC), Al ₂ O ₃ , TiN, Cr ₂ O _{3 and the} like. Among them, WC is particularly preferable. The WC coating can be performed by a thermal spraying method.

  In order to prevent the dope 24 from locally drying and solidifying at the lip tip of the casting die 93, it is preferable to attach a solvent supply device (not shown) for supplying a solvent to the lip tip in the vicinity of the lip tip. The position where the solvent is supplied is preferably a peripheral portion of a three-phase contact line formed by both ends of the casting bead, both ends of the lip tip, and the outside air. The flow rate of the supplied solvent is preferably 0.1 mL / min to 1.0 mL / min for each side. Thereby, it is possible to prevent foreign matters such as solid components precipitated from the dope 24 and those mixed in the casting bead from the outside from being mixed in the casting film 61. In addition, as a pump which supplies a solvent, it is preferable to use a pulsation rate of 5% or less.

  A casting band 94 is provided below the casting die 93 so as to span the rotating rollers 97 and 98. The casting band 94 is continuously conveyed by the driving rotation of at least one of the rotating rollers. The casting band 94 is transported endlessly so as to circulate around the casting chamber 80, the transport chamber 81, and a tank described later.

  The width of the casting band 94 is not particularly limited, but it is preferable to use a casting band 94 having a range of 1.1 to 2.0 times the casting width of the dope 24. Further, it is preferable that the length is 20 m to 200 m, the thickness is 0.5 mm to 2.5 mm, and the surface roughness is polished to be 0.05 μm or less.

  The material of the casting band 94 is not particularly limited, and may be, for example, an inorganic material such as stainless steel or a plastic film made of an organic material. Examples of the plastic film include non-woven plastic films such as polyethylene terephthalate (PET) film, polybutylene terephthalate (PBT) film, nylon 6 film, nylon 6,6 film, polypropylene film, polycarbonate film, and polyimide film. It is preferably a long product having chemical stability and heat resistance that can correspond to the solvent to be used and the film forming temperature. In this embodiment, a PET film that is a plastic film is used as the casting band 94.

  It is preferable to use a roller having a heat transfer medium attached inside the rotary rollers 97 and 98 so that the surface temperature of the casting band 94 is set to a predetermined value. In the present embodiment, a heat transfer medium flow path (not shown) is formed in the rotation rollers 97 and 98, and the heat transfer medium maintained at a predetermined temperature passes through the flow path to rotate. The temperature of the rollers 97 and 98 is held at a predetermined value. The surface temperature of the casting band 94 is appropriately set according to the type of solvent, the type of solid component, the concentration of the dope 24, and the like.

Instead of the rotating rollers 97 and 98 and the casting band 94, a rotating drum (not shown) can be used as a support. In this case, it is preferable that the rotation can be performed with high accuracy so that the rotation speed unevenness is 0.2% or less. The rotating drum preferably has an average surface roughness of 0.01 μm or less, and preferably has a surface subjected to a hard chrome plating treatment or the like. Thereby, sufficient hardness and durability can be improved. In addition, it is preferable that the surface defects of the rotating drum, the casting band 94, and the rotating rollers 97 and 98 are minimized. Specifically, there is no pinhole of 30 μm or more, and the number of pinholes of 10 μm or more and less than 30 μm is 1 / m ² or less, and the number of pinholes of less than 10 μm is preferably ² / m ² or less.

  In the vicinity of the casting die 93, a decompression chamber is provided to control the pressure on the upstream side in the running direction of the casting band 94 of the ribbon-shaped dope 24, that is, the casting bead formed from the casting die 93 to the casting band 94. (Not shown) is preferably provided. Further, it is preferable to provide a blower (not shown) in the vicinity of the casting band 94 and to blow air to evaporate the solvent of the casting film 61. In addition, it is preferable to provide a wind-shielding plate in the above-described air blower to suppress the wind that disturbs the shape of the casting film 61 from hitting the casting film 61. In addition, the casting chamber 80 is provided with a temperature controller for keeping the internal temperature at a predetermined value, and a condenser (condenser) (both not shown) for condensing and recovering the volatile organic solvent. It is done. This capacitor is preferably in the form of being provided with a recovery device for recovering the condensed organic solvent.

  Inside the transfer chamber 81 is provided a blower (not shown) that sends dry air adjusted to a desired temperature to promote drying of the casting film 61. Moreover, it is preferable that the transfer chamber 81 is divided into a plurality of sections and further adjusted to have different drying temperatures by attaching a drying device in each section. Thereby, since the casting film 61 can be dried gradually, it can suppress that a solvent volatilizes rapidly and shape changes, such as a wrinkle and a twist, generate | occur | produce. The number of compartments in the transfer chamber 81 is not particularly limited, but it is preferable to adjust the drying temperature in the transfer chamber 81 to be in the range of 30 ° C. or more and 60 ° C. or less. Further, the transfer chamber 81 is provided with a condenser (condenser) 99 for recovering the volatile solvent generated when the casting film 61 is dried. The condenser 99 is preferably provided with a recovery device for recovering the condensed and liquefied organic solvent.

  A tank 101 including a peeling roller 100 is provided downstream of the transfer chamber 81. In the tank 101 of this embodiment, pure water is stored as an immersion liquid, and the casting film 61 is immersed in the tank 101 together with the casting band 94.

  A pair of air knives 103 having a blowing port directed in the both-side direction of the precursor film 65 is provided downstream of the tank 101 and upstream of the tenter 83. Further, the tenter 83 is provided with a drying device that sends drying air and a number of clips 104 that travel as the chain (not shown) travels. Further, at the downstream side of the tenter 83, an ear cutting device 105 for cutting off both end portions (ear portions) of the precursor film 65 is provided. The crusher 105a for finely cutting the scraps on both side ends (called ears) of the cut precursor film 65 is connected to the ear clip device 105.

  As shown in FIG. 4, the acid treatment chamber 88 is provided with a coating device 110 and a first water tank 111 and a second water tank 112 disposed downstream of the coating apparatus 110.

  The coating device 110 is an extrusion type die coater. The coating apparatus 110 includes a supply port 116 connected to the tank 115 in which the first liquid 300 containing acid is stored, and an outlet 117 through which the first liquid 300 supplied from the supply port 116 flows out. The outflow port 117 includes an opening extending in the width direction of the precursor film 65. When the first liquid 300 is supplied from the supply device 115, the coating apparatus 110 discharges the first liquid 300 from the opening and uniformly applies the first liquid 300 to one surface of the precursor film 65. By applying the first liquid 300, a coating film 301a is formed on the one surface of the precursor film 65.

  A pump and a valve are provided between the pipe 118 connecting the tank 115 and the coating apparatus 110. A desired amount of the first liquid 300 can be applied on one surface of the precursor film 65 by operating the pump and the valve. Furthermore, the tank 115 includes a temperature adjusting unit 115 a for the first liquid 300. The temperature of the first liquid 300 is maintained at a desired temperature by the temperature adjustment unit 115a.

In addition, it is preferable that the quantity of the 1st liquid 300 apply | coated on one side of the precursor film 65 with such a coating device 110 shall be ² ml / m < ² > or more and 100 ml / m < ² > or less. When the coating amount of the first liquid 300 is 2 ml / m ² or less, the proton substitution reaction in the precursor film 65 is not sufficiently performed, and when the coating amount of the first liquid 300 is 100 ml / m ² or more. The film cannot be stably conveyed, which is not preferable.

  An infrared heater (hereinafter referred to as a heater) 120 is disposed on the downstream side of the coating apparatus 110. The heater 120 heats the hydrogen substitution film 65a, and can bring one side 301 of the hydrogen substitution film 65a to a desired temperature. In this embodiment, since the sulfuric acid aqueous solution is used as the first liquid 300, the temperature of the one surface 301 by the heating of the heater 120 is preferably 80 ° C. or higher and 100 ° C. or lower.

  The first water tank 111 stores water 200 as a cleaning liquid. In the second water tank 112, water 201 is stored as a cleaning liquid. The 1st water tank 111 and the 2nd water tank 112 are connected to the temperature control part 111a. The temperature adjusting unit 111a can independently maintain the temperatures of the waters 200 and 201 stored in the first water tank 111 and the second water tank 112. In addition, a set of air knives (not shown) are disposed downstream of the first water tank 111 and the second water tank 112 so as to face the conveyance path of the hydrogen substitution film 65a.

  As shown in FIG. 3, the drying chamber 84 includes a number of pass rollers 127, an adsorption / recovery device 128 for recovering the volatile solvent inside the drying chamber 84, and a drying device (not shown) for supplying drying air. Is provided. Further, the humidity control chamber 85 disposed downstream of the drying chamber 84 is provided with the same pass roller 127, temperature controller, and humidity controller (both not shown) as the drying chamber 84. A neutralization device (not shown) such as a neutralization bar is provided downstream of the humidity control chamber 85 to adjust the charged voltage of the hydrogen displacement film 65a to a predetermined range (for example, −3 kV to +3 kV). More preferably, a knurling roller pair (not shown) is provided, and knurling is preferably embossed on both side ends of the hydrogen-substituted film 65a. Inside the take-up chamber 86, a take-up roll 130 for taking up the film 70 and a press roller 131 for controlling the tension during take-up are provided.

  Next, an example of a method for manufacturing the film 70 using the film manufacturing facility 33 will be described.

  The dope 24 stored in the stock tank 32 is sent to a filtering device 96 by a pump 95 and filtered to remove fine particles and foreign matters larger than a predetermined particle size contained in the dope 24, gel-like foreign matters, and the like.

After the filtered dope 24 is fed into the casting die 93, it is cast on the casting band 94 while forming a casting bead from the casting die 93. In this case, the relative positions of the rotary rollers 97 and 98 and at least one of the rotational speeds are adjusted so that the tension generated in the casting band 94 becomes 10 ³ N / m × 10 ⁶ N / m. Further, the relative speed difference between the casting band 94 and the rotating rollers 97 and 98 is adjusted to be 0.01 m / min or less. At the time of casting, the casting amount of the dope 24 is determined in consideration of the concentration of the dope 24 to be used and the desired thickness of the film product.

  The speed fluctuation of the casting band 94 is preferably 0.5% or less, and the meandering in the width direction that occurs when the casting band 94 makes one round is preferably 1.5 mm or less. In order to suppress the meandering, a detector (not shown) that detects the positions of both ends of the casting band 94 and a position adjustment that adjusts the position of the casting band 94 according to the detection data by the detector. More preferably, a machine (not shown) is provided to feedback control the position of the casting band 94. In addition, it is preferable that the vertical position variation of the casting band 94 immediately below the casting die 93 with the rotation of the rotary rollers 97 and 98 be within 200 μm. The casting chamber 80 is preferably provided with a temperature controller (not shown), so that the temperature is set to -10 ° C to 57 ° C. Solvent evaporated in the casting chamber 80 is recovered by a recovery device (not shown) and then regenerated and reused as a solvent for dope production, which is also preferable for obtaining effects such as reduction in manufacturing cost.

  In order to stabilize the state of the casting bead, it is preferable to control in the decompression chamber so that the upstream area of the bead has a predetermined pressure value. The reduced pressure value by the decompression chamber is preferably −2500 Pa to −10 Pa from the downstream area with respect to the bead. It is preferable to attach a jacket (not shown) to the decompression chamber so that the internal temperature is kept at a predetermined temperature. In order to keep the shape of the casting bead desired, it is preferable to attach a suction device (not shown) to the edge portion of the casting die 93 to suck both sides of the casting bead. The edge suction air volume is preferably in the range of 1 L / min to 100 L / min.

  The casting film 61 on the casting band 94 is transported through the casting chamber 80 and the conveyance chamber 81 by driving the rotary rollers 97 and 98 to drive the casting band 94. In the transfer chamber 81, drying air is supplied from a drying device (not shown) to promote drying of the casting film 61. The capacitor 99 condenses and recovers the volatile solvent inside the transfer chamber 81.

  Subsequently, the casting band 94 on which the casting film 61 is formed is fed into the tank 101 and immersed in the immersion liquid. In this embodiment, water is used as the immersion liquid. Then, the casting film 61 is peeled off from the casting band 94 by the peeling roller 100 to obtain the precursor film 65. The precursor film 65 is guided in a predetermined direction by a guide roller. Further, since the casting band 94 after the casting film 61 has been peeled off travels endlessly as the rotary rollers 97 and 98 are driven, the casting band 94 is fed into the casting chamber 80 again.

  The form in which the casting film 61 is immersed in water in the tank 101 is not particularly limited, but the time for immersing the casting film 61 in the aqueous solution is 1 minute or more and 60 minutes or less. The self-supporting property of the cast film 61 can be expressed, and the precursor film 65 can be peeled off from the casting band 94.

  Subsequently, the precursor film 65 is sent out from the tank 101 by the guide roller. Air is blown onto the surface of the precursor film 65 by the air knife 103 to remove moisture adhering to the surface of the precursor film 65. This precursor film 65 is fed into the tenter 83. In the tenter 83, the clip 104 grips both end portions of the precursor film 65 and conveys the chain as the chain travels. During the conveyance of the precursor film 65, drying air adjusted to a desired temperature is applied to the precursor film 65 to promote drying of the precursor film 65. However, the clip 104 may be replaced with a pin, and this pin may be transported after being held by being pierced at both end portions of the precursor film 65. At this time, it is preferable to adjust the temperature of the tenter 83 to 80 ° C. or more and 140 ° C. or less by adjusting the temperature of the drying air. In this embodiment, the internal temperature is adjusted to be about 120 ° C. In the present embodiment, it is preferable to divide the inside of the tenter 83 into four temperature zones that differ in the transport direction, and to adjust the drying conditions appropriately for each zone.

  In the tenter 83, the precursor film 65 can be stretched in the width direction. It is also possible to stretch the precursor film 65 in the transport direction by adjusting the tension in the transport direction applied to the precursor film 65 before being fed into the tenter 83. Moreover, when extending | stretching the precursor film 65, it extends | stretches so that it may become a dimension of 100.5%-300% with respect to the dimension before extending | stretching at least 1 direction of the conveyance direction and the width direction of the precursor film 65. It is preferable to do. Thereby, the molecular orientation of the precursor film 65 can be adjusted.

  The precursor film 65 is fed into the ear-cutting device 105, where both side end portions are cut and removed. Thus, the film 70 which is excellent in planarity can be obtained by excising the both ends of the precursor film 65 damaged by the clip. In addition, the cut | disconnected both side edge part is sent into the crusher 105a with a cutter blower (not shown), and it grind | pulverizes here, and becomes a chip | tip. When this chip is reused as a polymer raw material for dope production, it is possible to effectively use the raw material or reduce production costs. In addition, although the process of cut | disconnecting the both-ends part of the precursor film 65 can also be abbreviate | omitted, after peeling off from the support body as the precursor film 65, it is preferable to carry out in any until it winds up a film.

  Using the coating apparatus 110, the first liquid 300 containing acid is applied to one side of the precursor film 65 whose both ends are cut. And using the heater 120, the single side | surface 301 of this precursor film 65 is heated to 80 degreeC or more and 100 degrees C or less. By the heating of the heater 120, the precursor film 65 is sufficiently subjected to proton substitution, and the precursor film 65 becomes the hydrogen substitution film 65a.

  Next, the hydrogen substitution film 65a that has been sufficiently subjected to proton substitution is fed into the first water tank 111, and the hydrogen substitution film 65a is immersed in the water 200 and washed. The washed hydrogen replacement film 65a is removed from the water 200. Next, the water 200 adhering to this hydrogen substitution film 65a is drained using an air knife. The drained hydrogen replacement film 65a is fed into the first water tank 112, and the hydrogen replacement film 65a is immersed in the water 201 and washed. The washed hydrogen replacement film 65a is removed from the water 200. The water 200 adhering to this hydrogen substitution film 65a is drained using an air knife. Moreover, in the 1st water tank 111 and the 2nd water tank 112, since the temperature of water 200,201 is hold | maintained at 30 degreeC or more, the removal effect of the acid adhering to the hydrogen substitution film 65a in a washing | cleaning process improves.

  Subsequently, the hydrogen substitution film 65 a is sent into the drying chamber 84. In the drying chamber 84, drying air is supplied from a drying device while the hydrogen-substituted film 65 a is being conveyed while being wound around the pass roller 127 and is dried. The internal temperature of the drying chamber 84 is not particularly limited, but is determined according to the heat resistance (glass transition point Tg, heat distortion temperature, melting point Tm, continuous use temperature, etc.) of the solid electrolyte, and is Tg or less. In the present invention, the internal temperature of the drying chamber 84 is preferably 80 ° C. or more and 200 ° C. or less, and the film 70 is dried until the residual solvent amount of the film 70 is less than 10% by weight with respect to the dry weight standard. Is preferred. The solvent gas generated by evaporation from the film 70 is adsorbed and collected by the adsorption / recovery device 108, and after removing the solvent component, is sent again into the drying chamber 84 as drying air.

  It is more preferable that the drying chamber 84 is divided into a plurality of sections in the transport direction in order to change the blowing temperature. In addition, when a preliminary drying chamber (not shown) is provided between the ear opener 105 and the drying chamber 84 to preliminarily dry the hydrogen-substituted film 65a, the temperature of the hydrogen-substituted film 65a is prevented from rapidly rising in the drying chamber 84. Therefore, a significant shape change of the hydrogen-substituted film 65a in the drying chamber 84 can be suppressed, and the film 70 with little shape change can be obtained.

  The film 70 is carried into the humidity control chamber 85. In the humidity control chamber 85, the humidity is adjusted by adjusting the temperature control device and the humidity control device to a desired temperature and humidity while the film 70 is conveyed while being wound around the pass roller 127 as in the drying chamber 84. And control its water content. The temperature and humidity in the humidity control chamber 85 are not particularly limited, but the temperature is preferably 20 ° C. or higher and 30 ° C. or lower, and the humidity is preferably 40 RH% or higher and 70 RH% or lower. Thereby, it can suppress that a curling generate | occur | produces on the surface of the film 70, or a winding defect generate | occur | produces when winding. In addition, it is preferable to provide a cooling chamber (not shown) between the drying chamber 84 and the humidity control chamber 85 and cool the film 70 to approximately room temperature because it is possible to suppress the shape change of the film 70 due to a temperature change. .

  A static eliminator (not shown) is provided between the humidity control chamber 85 and the winding chamber 86, and the charged voltage is set to a predetermined value while the film 70 is being conveyed. The charged voltage after neutralization is preferably -3 kV to +3 kV. Furthermore, it is preferable that the film 70 is provided with a knurling roller pair to be knurled. In addition, it is preferable that the uneven | corrugated height of the location which provided the knurling is 1 micrometer-200 micrometers.

  Finally, the film 70 is fed into the take-up chamber 86 and taken up on the take-up roll 130 while applying a tension with the press roller 131. Thereby, the roll-shaped film 70 can be obtained, suppressing generation | occurrence | production of a wrinkle, a twist, etc. Thus, it is preferable to wind the film while applying a desired tension to the film 70 with the press roller 131, because a roll-shaped film product having excellent flatness can be obtained. In order to prevent excessive winding in the film roll, it is more preferable to gradually change the tension from the start to the end of winding. In addition, the width of the film 70 to be wound is preferably 100 mm or more, but the present invention is also applied when manufacturing a thin film having a thickness of 5 μm or more and 300 μm or less.

  As described above, in the present invention, since the film 70 is manufactured using the film manufacturing facility 33 in which a plurality of apparatuses are combined based on each step of the solid electrolyte film manufacturing process 10, it has been performed offline until now. In addition, any process including acid treatment can be continuously performed online. This makes it possible to continuously produce a large number of films 70 having high proton conductivity.

  In the above embodiment, in the water washing step 69, a method of spraying the cleaning liquid onto the hydrogen replacement film 65a may be used instead of the method of immersing the hydrogen replacement film 65a in the cleaning liquid. Specific examples of the water spraying method used in the present invention include a method using an application head such as ectrusion, fountain coater, frog mouth coater, etc., spray nozzle used for air humidification and painting, automatic tank cleaning, etc. The method using is mentioned. These coating methods are summarized in “All about Coating” edited by Masayoshi Araki, Processing Technology Research Group (1999). In addition, the spray nozzles can be installed so that the water flow collides with the entire width by arranging spray nozzles such as conical and fan shapes from Ikeuchi Co., Ltd. in the width direction of the transparent resin film. .

  The higher the water spray speed, the higher the turbulent mixing, but there is a preferable range because there is a risk of impairing the transport stability of the transparent resin film that is continuously transported. Usually, it sprays on the alkaline coating liquid surface with the impact speed of 50-1000 cm / sec, Preferably it is 100-700 cm / sec, More preferably, it is 100-500 cm / sec.

  In the solid electrolyte film manufacturing process 10 described above, the coating apparatus 110 that applies the first liquid 300 to one surface of the precursor film 65 is used in the acid treatment process 68. In addition, the other surface of the precursor film 65 is used. Alternatively, a coating apparatus 170 that applies the second liquid 302 may be used. FIG. 5 shows an outline of the acid treatment chamber 88 when a rod coater type coating device 170 is used in addition to the coating device 110. In addition, about the apparatus and member similar to embodiment mentioned above, the same code | symbol is used and description of these details is abbreviate | omitted.

  In the acid treatment chamber 88 described above, the coating device 170 is disposed on the upstream side of the coating device 110. The coating device 170 includes a roller 171, a container 172, and guide rollers 173 a and 173 b. The heater 175 is disposed at a position facing the heater 120 with the precursor film 65 interposed therebetween. The container 172 stores a second liquid 302 containing an acid. The container 172 is connected to a temperature adjustment unit 172a, and the temperature of the second liquid 302 is maintained at a predetermined value by the temperature adjustment unit 172a. The roller 171 is formed in a cylindrical shape. The roller 171 is disposed in the container 172 such that a part of the peripheral surface of the roller 171 is immersed in the second liquid 302. The shaft 151a of the roller 171 is connected to a motor (not shown). By driving the motor, the roller 171 rotates around the shaft 171a in a predetermined direction at a predetermined speed. Due to the rotation of the roller 171, the peripheral surface of the roller 171 immersed in the second liquid 302 is exposed from the second liquid 302. A predetermined amount of the second liquid 302 adheres to the exposed peripheral surface of the roller 171. As the roller 171 rotates, the second liquid 302 attached to the peripheral surface is guided to the precursor film 65.

  The guide roller 173 a is disposed on the upstream side of the roller 171, and the guide roller 173 b is disposed on the downstream side of the roller 171. These guide rollers 173a and 173b convey the precursor film 65 sent from the edge-cutting device 105 to the acid treatment chamber 88 in a predetermined direction.

  The other surface 303 of the precursor film 65 conveyed by the guide rollers 173a and 173b, that is, the surface opposite to the one surface is in contact with the peripheral surface of the roller 171 that conveys the second liquid 302. Due to the contact between the other surface 303 of the precursor film 65 and the peripheral surface of the roller 171, the second liquid 302 on the peripheral surface of the roller 171 is continuously applied onto the other surface 303 of the precursor film 65. Thus, a coating film 303a is formed on the other surface 303 of the precursor film 65.

  The precursor film 65 having the coating film 303a formed on the other surface 303 is guided to the coating apparatus 110 by the guide rollers 173a and 173b. The coating device 110 applies the first liquid 300 to one side 301 of the precursor film 65, and forms a coating film 301a on the one side 301.

  The precursor film 65 on which the coating films 301a and 303a of the first liquid 300 and the second liquid 302 are formed on both surfaces is conveyed to the heaters 120 and 175. The heater 120 heats one surface 301 of the precursor film 65, and the heater 175 heats the other surface 303 of the precursor film 65. In this way, the one surface 301 and the other surface 303 to which the first liquid 300 and the second liquid 302 are applied are heated to a desired temperature, and the precursor 12a included in the precursor film 65 is proton-substituted to become a solid electrolyte. The hydrogen substitution film 65b obtained in this way becomes the film 70b through the water washing step 69 and the second drying step 72, as in the above-described embodiment.

  The heater 175 can heat the other surface 303 of the precursor film 65 at a desired temperature. The temperature of the precursor film 65 due to the heating of the heater 175 is preferably 80 ° C. or higher and 100 ° C. or lower, like the heater 120.

  The first liquid 300 is the same as that in the above-described embodiment. As the second liquid 302, either pure water or a liquid containing an acid may be used. When the second liquid 302 is an acid-containing liquid, the proton concentration is lower than that of the first liquid 300, and the difference in proton concentration between the first liquid 300 and the second liquid 302 is 0.05 mol / l or more. Is used. If the difference in proton concentration between the first liquid 300 and the second liquid 302 is less than 0.05 mol / l, proton substitution in the precursor film 65 is not sufficiently performed, which is not preferable. Similarly to the first liquid 300, by using an acid having an anion formula weight of 40 or more and 1000 or less as the second liquid 302, highly efficient proton substitution can be performed in the acid treatment step 68. Furthermore, like the first liquid 300, the proton substitution rate can be further improved by adjusting the temperature of the second liquid 302 to 30 ° C. or higher and lower than the boiling point of the second liquid 302.

With this coating device 170, it is preferable that the coating amount of the second liquid 302 on the other surface 303 of the precursor film 65 is 2 ml / m ² or more and 100 ml / m ² or less. When the coating amount of the second liquid 302 is 2 ml / m ² or less, the proton replacement in the precursor film 65 is not sufficiently performed. On the other hand, when the application amount of the second liquid 302 is 100 ml / m ² or more, the film cannot be stably conveyed, which is not preferable. Instead of the above-described coating apparatus 170, known coating means such as the above-described coating means, coating apparatus 110, rod coater or gravure coater may be used. It is more preferable to use the coating apparatus 110 or 170 in consideration of performing the solid electrolyte film manufacturing process 60 on-line and ease of adjusting the coating amount of the first liquid 300 and the second liquid 300.

  In the above embodiment, (1) Application of the second liquid 302 to the other surface 303 of the precursor film 65 (2) Application of the first liquid 300 to one surface 301 of the precursor film 65 (3) Application of the precursor film 65 Although each process was performed in the order of heating on both sides, the present invention is not limited to this and may be performed in another order. That is, the first and second liquids 302 having a predetermined acid concentration may be applied to each surface, each surface may be heated at a predetermined temperature, and proton substitution may be performed with the precursor film 65. For example, the first liquid 300 is applied to one side 301 of the precursor film 65, the one side 301 is heated, and then the second liquid 302 is applied to the other side 303 of the precursor film 65, and the other side 303 is heated. Etc.

  The above-described precursor film 65 is dried and wound on a roll, or the precursor film piece 189 cut out from the precursor film 65 is subjected to an acid treatment step 68, a water washing step 69, and a second drying step 72. Can be obtained sequentially to obtain a solid electrolyte film. In addition, the manufacturing process of these solid electrolyte films is not restricted to an online system, You may perform each process by an offline system.

  Hereinafter, as an example of an apparatus that performs acid treatment on both surfaces of the precursor film 65 in an offline manner, an acid treatment apparatus 190 will be described as an example. In addition, the acid treatment apparatus used for this invention is not restricted to the following. As shown in FIG. 6, the acid treatment device 190 includes a pipe 191, a mantle heater 193, and a fixing ring 195. The mantle heater 193 includes a container 193a and a temperature control unit 193b. The temperature control unit 193b heats the container 193a with a predetermined heating amount. A first liquid 300 is stored in the container 193a.

  The pipe 191 includes an opening 191a and an opening 191b at both ends thereof. A fitting groove is formed on the peripheral surface on the opening 191a side. The fixing ring 195 has a hollow portion. The inner diameter of the hollow portion on the one end 195 a side of the fixing ring 195 is formed to be approximately the same as the outer diameter of the pipe 191. On the other hand, a fixing portion 195 is formed on the inner peripheral surface of the hollow portion on the other end 195b side. By forming the fixing portion 195, the inner diameter of the hollow portion on the other end 195 side is formed to have substantially the same dimension as the inner diameter of the pipe 191. A groove that can be fitted into the fitting groove of the pipe 191 is formed on the inner peripheral surface of the fixing ring 195 on the one end 195a side. In this way, the inner diameter of the fixing portion 195 c can fit the one end 195 a side of the fixing ring 195 and the opening portion 191 a side of the pipe 191.

  A precursor film piece 189 cut out to a predetermined size from the precursor film 65 is disposed between the opening 191 a of the pipe 191 and the end surface 195 a of the fixing ring 195. When the fixing ring 195 and the pipe 191 are fitted, the fixing portion 195c and the end surface 191c come into contact with each other through the precursor film piece 189. Thus, the precursor film piece 189 is held so as to close the opening 191a of the fixing ring 195.

  The pipe 191 is immersed in the first liquid 300 from the opening 191a. Then, a predetermined amount of the second liquid 302 is poured from the opening 191 c at the other end of the pipe 191. The container 193a is heated by the temperature controller 193b of the mantle heater 193, and the precursor film piece 189 is heated at a desired temperature through the heating of the first liquid 300 and the second liquid 302. In this way, the acid treatment apparatus 190 can perform the acid treatment by bringing the first liquid 300 and the second liquid 302 into contact with both surfaces of the precursor film piece 189.

  In the solution casting method, various steps such as a drying step and a side edge portion excision and removal step are performed before the film (solid electrolyte film) peeled off from the support is wound up. In each of these processes or between each process, the film is mainly supported or conveyed by a roller. These rollers include a driving roller and a non-driving roller, and the non-driving roller is mainly used for determining a film conveyance path and improving conveyance stability.

  In the present embodiment, the case where one kind of dope is cast is shown. However, in the present invention, two or more kinds of dopes may be co-cast simultaneously to form a laminated type casting film, or sequentially. Alternatively, a laminated type cast film may be formed by co-casting. In the case where two or more kinds of dopes are co-cast simultaneously, a casting die provided with a feed block may be used, or a multi-manifold casting die may be used. However, as for the film which consists of a multilayer by co-casting, it is preferable that any one of the two layers exposed on the surface is 0.5% to 30% of the total thickness of the film. In addition, when co-casting at the same time, when dope is cast from the die slit to the support, the concentration of each dope is adjusted in advance so that the high-viscosity dope is wrapped and cast by the low-viscosity dope. In the bead formed from the die slit to the support, it is preferable that the dope in contact with the outside world, that is, the exposed dope has a larger proportion of the poor solvent than the inner dope.

  In addition, it replaces with the said method the method of manufacturing a precursor film, a precursor film different from the said embodiment is made to hold | maintain a precursor to the pore of what is called a porous base material in which multiple pores are formed. Can be manufactured. As a method for producing such a precursor film, a method in which a sol-gel reaction liquid containing a precursor is applied onto a porous substrate and the precursor is put into pores, and the porous substrate includes the precursor. There is a method of immersing in a sol-gel reaction solution to fill the precursor in the pores. Preferable examples of the porous substrate include porous polypropylene, porous polytetrafluoroethylene, porous cross-linked heat-resistant polyethylene, and porous polyimide. Alternatively, the precursor film can be formed by processing the precursor into a fiber shape, filling the voids in the fiber with another polymer compound, and forming the film using the fiber. In this case, examples of the other polymer compound for filling the void include the substances mentioned as additives in the present specification. About each of these precursor films, a solid electrolyte film can be manufactured by performing proton substitution by the acid treatment mentioned above.

  The solid electrolyte film of the present invention can be suitably used as a proton conductive membrane for a fuel cell, in particular, a direct methanol fuel cell, and also used as a solid electrolyte film sandwiched between two electrodes of a fuel cell. Can do. Furthermore, as electrolytes, display elements, electrochemical sensors, signal transmission media, capacitors, electrodialysis, electrolytic membranes for electrolysis, gel actuators, salt electrolytic membranes, proton exchange resins in various batteries (redox flow batteries, lithium batteries, etc.) The solid electrolyte film of the present invention can be used.

(Fuel cell)
Hereinafter, an example in which the solid electrolyte film is used for an electrode membrane composite (hereinafter referred to as MEA) and an example in which the electrode membrane composite is used for a fuel cell will be described. However, the modes of the MEA and the fuel cell shown here are examples of the present invention, and the present invention is not limited thereto. The solid electrolyte film used in this embodiment may be either the film 70 or the film 70b described above. Hereinafter, the case of using the film 70 will be described as an example, and aspects of the MEA and the fuel cell will be described. FIG. 7 is a schematic cross-sectional view of the MEA. The MEA 161 includes a film 70 and an anode electrode 162 and a cathode electrode 163 that are opposed to each other with the film 70 interposed therebetween.

  The anode electrode 132 has a porous conductive sheet 132 a and a catalyst layer 132 b in contact with the film 70, and the cathode electrode 133 has a porous conductive sheet 133 a and a catalyst layer 133 b in contact with the film 70. Examples of the porous conductive sheets 132a and 133a include carbon paper. The catalyst layers 132b and 133b are made of a dispersion in which carbon particles carrying a catalyst metal such as platinum particles are dispersed in a proton conductive material. Examples of the carbon particles include ketjen black, acetylene black, and carbon nanotube. Examples of the proton conductive material include Nafion (registered trademark).

As the manufacturing method of the MEA 131, the following four methods are preferable.
(1) Proton conductive material coating method: A catalyst paste (ink) containing active metal-carrying carbon, proton conductive material, and solvent is directly applied to both surfaces of the film 70, and the porous conductive sheets 132a and 133a are applied to the (heat) coating layer. A MEA having a five-layer structure is manufactured by pressure bonding.
(2) Porous conductive sheet coating method: After a liquid containing the material of the catalyst layers 132b and 133b, for example, a catalyst paste, is applied to the surfaces of the porous conductive sheets 132a and 133a to form the catalyst layers 132b and 133b. Then, the film 70 is pressure-bonded to form a MEA 131 having a five-layer structure.
(3) Decal method: a catalyst paste is applied on PTFE to form catalyst layers 132b and 133b, and then only the catalyst layers 132b and 133b are formed on the film 70 to form a three-layer structure. The sheets 132a and 133a are pressure-bonded to produce a MEA 131 having a five-layer structure.
(4) Post-catalyst support method: After coating and forming a film 70, porous conductive sheets 132a, 133a or PTFE with an ink in which a platinum non-supported carbon material is mixed with a proton conductive material, the film is applied to a liquid containing platinum ions. 70 is impregnated, and platinum particles are reduced and deposited in the film to form the catalyst layers 132b and 133b. After the formation of the catalyst layers 132b and 133b, the MEA 131 is produced by the above methods (1) to (3).

  However, the method of making the MEA is not limited to the above method, and various known methods can be applied. For example, in addition to the above methods (1) to (4), there are the following methods. A coating solution containing the materials of the catalyst layers 132b and 133b is prepared in advance, and this coating solution is applied to a support and dried. The support on which the catalyst layers 132b and 133b are formed is pressure-bonded on the both surfaces of the film 70 so that the catalyst layers 132b and 133b are in contact with the film 70, respectively. And after peeling a support body, the film 70 in which the catalyst layers 132b and 133b were formed in both surfaces is pinched | interposed with the porous conductive sheets 132a and 133a. And MEA can be manufactured by closely contacting the porous conductive sheets 132a and 133a and the catalyst layers 132b and 133b.

  FIG. 8 is a schematic view of a fuel cell. The fuel cell 141 includes an MEA 131, a pair of separators 142 and 143 that sandwich the MEA 131, a current collector 146 made of a stainless net attached to the separators 142 and 143, and a packing 147. An anode pole side opening 151 is provided in the anode pole side separator 142, and a cathode pole side opening 152 is provided in the cathode pole side separator 143. Gas fuel such as hydrogen and alcohols (such as methanol) or liquid fuel such as an alcohol aqueous solution is supplied from the anode electrode side opening 151, and oxidant gas such as oxygen gas and air is supplied from the cathode electrode side opening 152. Is supplied.

  A catalyst in which active metal particles such as platinum are supported on a carbon material is used for the anode electrode 132 and the cathode electrode 133. Commonly used active metal particle sizes are in the range of 2 to 10 nm. However, the smaller the particle size, the greater the surface area per unit weight, which increases the activity and is advantageous. However, if it is too small, it is difficult to disperse without agglomeration, so about 2 nm is said to be the small limit. .

  The active polarization in the hydrogen-oxygen fuel cell is larger in the cathode electrode, that is, the air electrode than in the anode electrode, that is, the hydrogen electrode. This is because the rate of the cathode electrode reaction, that is, the oxygen reduction reaction, is slower than that of the anode electrode. For the purpose of improving the activity of the oxygen electrode, various platinum-based binary metals such as Pt—Cr, Pt—Ni, Pt—Co, Pt—Cu, and Pt—Fe can be used. In a direct methanol fuel cell using a methanol aqueous solution as the anode fuel, in order to suppress catalyst poisoning by CO generated during the oxidation process of methanol, Pt—Ru, Pt—Fe, Pt—Ni, Pt—Co, and Pt—Mo are used. Pt-Ru-Mo, Pt-Ru-W, Pt-Ru-Co, Pt-Ru-Fe, Pt-Ru-Ni, Pt-Ru-Cu, Pt-Ru-Sn, etc. A platinum group ternary metal such as Pt—Ru—Au can be used. As the carbon material for supporting the active metal, acetylene black, Vulcan XC-72, ketjen black, carbon nanohorn (CNH), and carbon nanotube (CNT) are preferably used.

The catalyst layers 132b and 133b are generated by (1) transporting the fuel to the active metal, (2) providing a field for the oxidation (anode electrode) and reduction (cathode electrode) reaction of the fuel, and (3) oxidation / reduction. And (4) transports protons generated by the reaction to the solid electrolyte, that is, the film 70. For (1), the catalyst layers 132b and 133b are made porous so that liquid and gaseous fuel can permeate deeply. For (2), the active metal catalyst supported on the carbon material is responsible, and (3) is also responsible for the carbon material. In order to fulfill the function (4), a proton conductive material is mixed in the catalyst layers 132b and 133b. The proton conductive material of the catalyst layer is not limited as long as it is a solid having a proton donating group, but a polymer compound having an acid residue, for example, perfluorosulfonic acid represented by Nafion (registered trademark), side chain A sulfonated product of a heat-resistant aromatic polymer such as phosphoric acid group poly (meth) acrylate, sulfonated polyetheretherketone, and sulfonated polybenzimidazole is preferably used. When the solid electrolyte contained in the film 70 is used for the catalyst layers 132b and 133b, the catalyst layers 132b and 133b and the film 70 are made of the same material, so that the electrochemical adhesion between the solid electrolyte and the catalyst layer is increased, and protons More advantageous in terms of conduction. It is suitable from a viewpoint of battery output and economical efficiency to make the usage-amount of an active metal into the range of 0.03-10 mg / cm < ² >. The amount of the carbon material supporting the active metal is preferably 1 to 10 times the weight of the active metal. The amount of the proton conductive material is preferably 0.1 to 0.7 times the weight of the active metal-carrying carbon.

  The catalyst layers 132b and 133b are also referred to as an electrode base material, a permeable layer, or a backing material, and play a role of preventing current collection and deterioration of gas permeation and accumulation of water. Usually, carbon paper or carbon cloth can be used, and polytetrafluoroethylene (PTFE) treated for water repellency can be used.

MEA is incorporated into a battery, preferably having an area resistance value of 3Omucm ² below by the AC impedance method in a state filled with fuel, more preferably those of 1 .OMEGA.cm ² or less, and most preferably those 0.5Omucm ² below. The area resistance value is obtained from the product of the actually measured resistance value and the area of the sample.

  What can be used as a fuel of a fuel cell will be described. Examples of the anode fuel include hydrogen, alcohols (such as methanol, isopropanol, and ethylene glycol), ethers (such as dimethyl ether, dimethoxymethane, and trimethoxymethane), formic acid, borohydride complex, and ascorbic acid. Examples of the cathode fuel include oxygen (including oxygen in the atmosphere) and hydrogen peroxide.

In the direct methanol fuel cell, a methanol aqueous solution having a methanol concentration of 3 to 64% by weight is used as the anode fuel. According to the anode reaction formula (CH ₃ OH + H ₂ O → CO ₂ + 6H ⁺ + 6e ⁻ ), 1 mol of water is required for 1 mol of methanol, and the methanol concentration at this time corresponds to 64% by weight. The higher the methanol concentration, there is an advantage that the weight and volume of the battery including the fuel tank with the same energy capacity can be reduced. However, as the methanol concentration is higher, the so-called crossover phenomenon, in which methanol permeates the solid electrolyte film and reacts with oxygen on the cathode side to lower the voltage, becomes more prominent, and the output tends to decrease. Therefore, the optimum concentration is determined by the methanol permeability of the solid electrolyte film to be used. The cathode reaction formula of the direct methanol fuel cell is (3/2) O ₂ + 6H ⁺ + 6e ⁻ → H ₂ O, and oxygen (usually oxygen in the air) is used as the fuel.

  As a method of supplying the anode fuel and the cathode fuel to the respective catalyst layers 132b and 133b, (1) a method of forcibly feeding using an auxiliary device such as a pump (active type), and (2) an auxiliary device There are two methods that are not used, for example, a passive type in which the fuel is exposed to the atmosphere by exposing the catalyst layer to the atmosphere due to capillary action or natural fall when the fuel is a liquid, and ( It is also possible to combine 1) and (2). (1) has the advantage that by extracting the water produced on the cathode side, high-concentration methanol can be used as the fuel, and high output can be achieved by air supply, but a fuel supply system is provided. Therefore, there is a drawback that miniaturization is difficult. Although (2) has the advantage that it can be downsized, it has a drawback that the fuel supply is likely to be rate-limiting and it is difficult to produce a high output.

  Since the single cell voltage of the fuel cell is generally 1 V or less, the single cells are used by stacking in series according to the required voltage of the load. As the stacking method, “planar stacking” in which single cells are arranged on a plane and “bipolar stacking” in which single cells are stacked via separators having fuel flow paths formed on both sides thereof are used. The former is suitable for a small fuel cell because the cathode electrode (air electrode) comes out on the surface, so that air can be easily taken in and can be made thin. In addition to this, a method of applying MEMS technology, performing fine processing on a silicon wafer, and stacking has been proposed.

  Fuel cells are considered for various uses such as for automobiles, homes, and portable devices.In particular, direct methanol fuel cells are advantageous in that they can be reduced in size and weight and do not require charging. It is expected to be used as an energy source for various portable devices and portable devices. For example, mobile devices that can be preferably applied include mobile phones, mobile laptop computers, electronic still cameras, PDAs, video cameras, portable game machines, mobile servers, wearable personal computers, mobile displays, and the like. Examples of portable devices that can be preferably applied include portable generators, outdoor lighting devices, flashlights, and electric (assist) bicycles. It can also be preferably used as a power source for industrial or household robots or other toys. Furthermore, it is also useful as a power source for charging secondary batteries mounted on these devices.

  Next, examples of the present invention will be described. In each of the following Examples, Examples 1 to 5 are examples of embodiments of the present invention, and Examples 6 to 10 are comparative experiments with respect to Examples 1 to 5.

A compound in which X in Chemical Formula 3 is a cationic species other than H was used as a precursor. This precursor is referred to as raw material A. Further, the compound of Chemical Formula 3 in this example is such that X is Na, Y is SO ₂ , Z is Chemical Formula (I), n is 0.33, m is 0.67, number average molecular weight Mn is 61000, amount The average molecular weight Mw is 159000. The solvent is a mixture of the solvent component 1 and the solvent component 2. The solvent component 1 is a good solvent for the raw material A, and the solvent component 2 is a poor solvent for the raw material A. The raw material A and the solvent were mixed in a predetermined composition, and the solid content of the raw material A was dissolved in the solvent to produce a dope containing 20% by weight of the precursor based on the total weight. This dope is referred to as dope A in the following description.
-Raw material A; 100 parts by weight-Solvent component 1; 256 parts by weight of dimethyl sulfoxide-Solvent component 2; 171 parts by weight of methanol

[Production of solid electrolyte film]
A casting film is cast from the casting die 93 to the PET film running on the dope A to form a casting film 61, and a dry air of 45 ° C./10% RH is blown for 30 minutes by a blow duct, and the residual solvent amount is 200 with respect to the dry amount standard. The cast membrane was dried until weight percent. The casting film 61 was immersed in water at 30 ° C. together with the PET film, and the casting film 61 was peeled off from the PET film to obtain a precursor film 65. And the precursor film 65 was immersed in water as it was, and solvent substitution was performed. The peeling time from the PET film and the time required for solvent replacement were 5 minutes. Thus, a precursor film 65 having a self-supporting property and having a residual solvent amount of 150% by weight based on the dry weight standard was obtained. This precursor film 65 was sent to the tenter 83 and conveyed inside the tenter 83 while the clip 104 held both side ends thereof. In the tenter 83, the precursor film 65 was dried with a drying air at 120 ° C. for 10 minutes. Thus, a precursor film 65 having a residual solvent amount of 10% by weight with respect to the dry weight standard was obtained. The precursor film 65 was detached from the clip 104 at the outlet of the tenter 83, and both end portions gripped by the clip 104 were cut and removed by the ear clip device 105 provided downstream of the tenter 83. Using the coating apparatus 110, the first liquid 300 was applied to one side of the precursor film 65 at 50 ml / m ² , and a coating film was formed on one side of the precursor film 65. As the first liquid 300, an aqueous sulfuric acid solution having a proton concentration of 2.0 mol / l at 70 ° C. was used. The precursor film 65 to be conveyed was heated at 80 to 100 ° C. using the heater 120. By this heating, the precursor film 65 becomes the hydrogen substitution film 65a. This hydrogen substitution film 65a was immersed in the 1st water tank 111 in which the water 200 with a water temperature of 70 degreeC was stored, and washed with water. Furthermore, this hydrogen substitution film 65a was immersed in the 2nd water tank 112 in which the water 201 with a water temperature of 70 degreeC was stored, and was washed with water again. Subsequently, the hydrogen-substituted film 65a was drained using an air knife. The drained hydrogen-substituted film 65 a was sent to the drying chamber 84 and dried at 60 to 120 ° C. while being conveyed by a plurality of rollers 127. And the film 70 by which the solvent residual amount was made into less than 5% with respect to the dry weight standard was obtained. The evaluation results for the obtained film 70 are shown in Table 1.

  In the solid electrolyte film manufacturing process 10, the formed precursor film 65 is passed through the first drying process 67 and the second drying process 72 to obtain a dried precursor film. Then, the acid treatment was performed to the precursor film piece 189 cut out to the predetermined dimension from the dry precursor film using the acid treatment apparatus 190 mentioned above. As the first liquid 300, an aqueous sulfuric acid solution having a proton concentration of 1.0 mol / l was used. As the second liquid 302, ion-exchanged water was used. With the first liquid 300 in contact with one side of the precursor film piece 198 and the second liquid 302 in contact with the other side, the first and second liquids 302 were boiled for 2 hours for acid treatment. Ion exchange water was poured into the precursor film piece 189 after the acid treatment and washed with water. After performing this water washing twice, the precursor film piece 189 was immersed in distilled water and boiled for 2 hours. The evaluation results for the solid electrolyte film thus obtained are shown in Table 1.

A compound in which X in Chemical Formula 3 is a cationic species other than H was used as a precursor. This precursor is referred to as raw material B. In addition, the compound of Chemical Formula 3 in this example has X as Na, Y as SO ₂ , Z as Chemical Formula (I), n as 0.33, m as 0.67, number average molecular weight Mn as 68000, amount The average molecular weight Mw is 200,000. The solvent is a mixture of the solvent component 1 and the solvent component 2. The solvent component 1 is a good solvent for the raw material B, and the solvent component 2 is a poor solvent for the raw material B. The raw material B and the solvent were mixed in a predetermined composition, and the solid content of the raw material B was dissolved in the solvent to produce a dope containing 20% by weight of the precursor based on the total weight. This dope is referred to as dope B in the following description.
-Raw material B; 100 parts by weight-Solvent component 1; 200 parts by weight of dimethyl sulfoxide-Solvent component 2; 135 parts by weight of methanol Using this dope B, a solid electrolyte film was produced. The method for producing the solid electrolyte film was the same as in Example 1. The evaluation results for the obtained solid electrolyte film are shown in Table 1.

  Using Dope B, a solid electrolyte film was produced in the same manner as in Example 2. However, in the acid treatment step, a sulfuric acid aqueous solution having a proton concentration of 2.0 mol / l was used for the first liquid 300. The evaluation results for the obtained solid electrolyte film are shown in Table 1.

  A solid electrolyte film was produced in the same manner as in Example 4. However, in the acid treatment step, a sulfuric acid aqueous solution having a proton concentration of 1.0 mol / l was used for the first liquid 300, and a sulfuric acid aqueous solution having a proton concentration of 0.5 mol / l was used for the second liquid 302, respectively. The evaluation results for the obtained solid electrolyte film are shown in Table 1.

  In the same manner as in Example 1, a solid electrolyte film was produced using Dope A. However, in the acid treatment step, the precursor film was immersed in an aqueous sulfuric acid solution with a proton temperature of 1.0 mol / l at a liquid temperature of 70 ° C. to obtain a hydrogen-substituted film. The hydrogen-substituted film was immersed in pure water at 70 ° C. and washed with water. Furthermore, the same water washing was performed using new pure water. After washing with water and draining with an air knife, it was sent to the drying chamber 84 and dried at 60 to 120 ° C. while being conveyed by a plurality of rollers 127. The evaluation results for the obtained solid electrolyte film are shown in Table 1.

  In the same manner as in Example 2, a solid electrolyte film was produced using Dope A. However, in the acid treatment step, the precursor film piece was immersed in a sulfuric acid aqueous solution having a proton concentration of 1.0 mol / l and boiled for 2 hours. The evaluation results for the obtained solid electrolyte film are shown in Table 1.

  About dope B, it carried out similarly to Example 6, and manufactured the solid electrolyte membrane. The evaluation results for the obtained solid electrolyte film are shown in Table 1.

  About dope B, it carried out similarly to Example 7, and manufactured the solid electrolyte membrane. The evaluation results for the obtained solid electrolyte film are shown in Table 1.

  A solid electrolyte film was produced in the same manner as in Example 5. However, in the acid treatment step, a sulfuric acid aqueous solution having a proton concentration of 1.0 mol / l was used for the first liquid 300, and a sulfuric acid aqueous solution having a proton concentration of 0.95 mol / l was used for the second liquid 302, respectively. The evaluation results for the obtained solid electrolyte film are shown in Table 1.

  The characteristics of the obtained solid electrolyte film were evaluated by measuring the following items. The following measurements are common to all Examples 1 to 10, and the evaluation results in each example are summarized in Table 1. The numbers of the evaluation items in Table 1 correspond to the numbers given to the following evaluation items.

1. Proton substitution rate After measuring the weight of the dried film, it was immersed in an aqueous NaOH solution having a concentration of 0.2 mol / l for 2 hours for alkali treatment. Moreover, the NaOH aqueous solution was stirred during immersion. After the alkali-treated film was taken out, it was subjected to back titration with an aqueous hydrochloric acid solution to determine the ion exchange capacity (ICE). And the amount of the sulfonic acid group substituted by the proton was calculated by comparison with the theoretical value calculated from the introduction amount of the sulfonic acid group (n = 0.33), and this was evaluated as the proton substitution rate.

2. Proton conductivity The proton conductivity was measured using a four-terminal AC method according to Journal of the Electronic Society 143, No. 4, 1254-1259 (1996). Specifically, first, a sample obtained by cutting out the solid electrolyte film produced in Examples 1 to 10 to a length of 2 cm and a width of 1 cm was used as a sample. Next, after placing the previous sample on a PTFE plate with four platinum wires fixed at intervals of 5 mm, a PTFE plate was further placed thereon, and these were fixed with screws to form a test cell. Then, using this test cell and an impedance analyzer combining Solartron 1480 type and 1225B type, proton conductivity was measured by an AC impedance method in 80 ° C. on water.

3. Output density of fuel cell A fuel cell 141 was produced using the solid electrolyte films obtained in Examples 1 to 10, and the output of the fuel cell 141 was measured. The production method of the fuel cell 141 and the measurement method of the power density are as follows.

(1) Preparation of catalyst sheet A as catalyst layers 132b and 133b 2g of platinum-supported carbon (50% by weight of platinum supported on Vulcan XC72) and 5% alcohol aqueous solution as Nafion solution (registered trademark DuPont) 15 g was mixed and dispersed with an ultrasonic disperser for 30 minutes for 0 minutes. The average particle size of the dispersion was about 500 nm. The obtained dispersion was coated on a polytetraethylene film containing a reinforcing material (manufactured by Saint-Gobain Co., Ltd.), dried, and then punched into a circle having a diameter of 9 mm to prepare a catalyst sheet A.

(2) Production of MEA 131 The catalyst sheet A was laminated on both sides of the solid electrolyte film obtained in Examples 1 to 10 so that the coating film was in contact with the solid electrolyte film, and thermocompression bonded at 210 ° C., 3 MPa for 10 minutes, pressure After the temperature was lowered while applying MEA, the support of the catalyst sheet A was peeled to prepare MEAs in order.

(3) Output density of fuel cell 141 After stacking a gas diffusion electrode (manufactured by E-TEK) cut to the same size as the electrode on the MEA obtained in (2), a standard fuel cell test cell (manufactured by Electrochem) ). The test cell was connected to a fuel cell evaluation system (As-510, manufactured by NF Circuit Design Block Co., Ltd.). Then, a humidified hydrogen gas was supplied to the anode side, and a humidified simulated atmosphere was supplied to the one cathode side until the voltage was stabilized. Thereafter, a load was applied between the anode electrode and the cathode electrode, current-voltage characteristics at that time were recorded, and this was measured as the output density (W / cm ² ).

  As mentioned above, it turns out that the solid electrolyte film manufactured by Examples 1-5 is equipped with the outstanding proton conductivity compared with Examples 6-10 from the result of each Example. Moreover, the power density of a fuel cell provided with the solid electrolyte film manufactured in Examples 1-5 also shows the value excellent as a fuel cell compared with Examples 6-10. On the other hand, regarding the proton substitution rate, the solid electrolyte films produced in Examples 1 to 5 are not significantly different from those in Examples 6 to 10. From this result, it is understood that the proton conductivity of the solid electrolyte film is not improved only by the proton substitution rate. That is, it can be said that the method for producing a solid electrolyte film of the present invention has led to a factor for improving the proton conductivity of the solid electrolyte film. This improvement in proton conductivity can be presumed to be due to the acid treatment performed on only one side of the precursor film 65. Moreover, when the difference of the proton concentration of the 1st liquid 300 and the 2nd liquid 302 which contacts the single side | surface of the precursor film 65 in an acid treatment and the other surface is compared with Example 5 and Example 10 is more than fixed. Further, it can be seen that the effect of the present invention is exhibited.

  Therefore, according to the present invention, a high proton conductivity film can be continuously produced in large quantities while maintaining a high proton substitution rate while performing on-line acid treatment. Moreover, when the solid electrolyte film obtained by this manufacturing method is used as a solid electrolyte layer of a fuel cell, an excellent output density can be realized.

It is the schematic of an example of the dope manufacturing equipment used by this embodiment. It is a manufacturing-process figure of the film which concerns on this invention. It is the schematic of an example of the film manufacturing equipment which concerns on this invention. It is explanatory drawing which shows the outline | summary of the acid treatment chamber which concerns on this invention. It is explanatory drawing which shows the outline | summary of the acid treatment chamber which concerns on this invention. It is explanatory drawing which shows the outline | summary of the acid treatment apparatus which concerns on this invention. It is sectional drawing of an electrode membrane composite. It is sectional drawing of a fuel cell.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Dope manufacturing equipment 11a Solvent 12a Precursor 24 Dope 33 Film manufacturing equipment 60 Solid electrolyte film manufacturing process 61 Casting film 65 Precursor film 65a, 65b Hydrogen substitution film 68 Acid treatment process 70, 70b Solid electrolyte film 88 Acid treatment chamber 110 , 170 Coating device 120, 175 Heater 131 Electrode membrane composite (MEA)
132 Anode electrode 133 Cathode electrode 141 Fuel cell 146 Current collector 300 First liquid 301 One side 302 Second liquid 303 Other side

Claims (19)

In the method for producing a solid electrolyte film, a liquid containing an acid that is a proton donor is brought into contact with a precursor film that contains a polymer that is a precursor of a solid electrolyte.
A first step of bringing the liquid having a proton concentration of 0.05 mol / l or more into contact with one surface of the precursor film having a cation species to form a hydrogen-substituted film in which the cation species are substituted with hydrogen atoms;
A second step of cleaning the hydrogen-substituted film;
A third step of drying the hydrogen-substituted film and solid electrolyte film containing the solid electrolyte;
A method for producing a solid electrolyte film, comprising:   2. The method for producing a solid electrolyte film according to claim 1, wherein the temperature of the precursor film is 30 ° C. or more and the glass transition temperature of the precursor film or less.   3. The solid according to claim 1, wherein, in the first step, the other surface side is heated after contacting a solution having a lower proton concentration than the liquid with the other surface of the precursor film. Manufacturing method of electrolyte film.   The method for producing a solid electrolyte film according to claim 3, wherein a difference in the proton concentration between the liquid and the solution is 0.05 mol / l or more.   The method for producing a solid electrolyte film according to any one of claims 1 to 4, wherein the formula amount of the anion contained in the liquid or the solution is 40 or more and 1000 or less.   The method for producing a solid electrolyte film according to claim 3, wherein the solution is pure water.   The method for producing a solid electrolyte film according to claim 1, wherein the first step, the second step, and the third step are continuously performed.   8. The method for producing a solid electrolyte film according to claim 1, wherein at least one temperature of the solution and the liquid is set to 30 ° C. or more and a glass transition temperature of the precursor film or less. . A fourth step of casting a dope containing an organic solvent and the polymer on a traveling support from a casting die to form a casting film;
A fifth step of peeling the cast film from the support as the precursor film;
The method for producing a solid electrolyte film according to claim 1, comprising:   The solid electrolyte film according to any one of claims 1 to 9, wherein the fourth step, the fifth step, the first step, the second step, and the third step are continuously performed. Production method.   The method for producing a solid electrolyte film according to claim 1, wherein the polymer is a hydrocarbon-based polymer.   The method for producing a solid electrolyte film according to claim 11, wherein the hydrocarbon polymer is an aromatic polymer. 13. The method for producing a solid electrolyte film according to claim 12, wherein the aromatic polymer is a copolymer composed of structural units represented by general formulas (I) to (III) of Chemical Formula 1.

(However, X is a cation species excluding a hydrogen atom, Y is SO ₂ , Z is a structure shown in Chemical Formula (I) or (II), and n and m are 0.1 ≦ n / (m + n) ≦ 0.5 is satisfied.)

In a production facility for a solid electrolyte film in which a liquid containing an acid as a proton donor is brought into contact with a precursor film containing a polymer that is a precursor of a solid electrolyte,
A contact device for bringing the liquid into contact with one side of the precursor film having a cationic species;
A heating device that heats the one side of the precursor film, and generates a hydrogen-substituted film in which the cationic species are replaced with hydrogen atoms from the precursor film;
A cleaning device for cleaning the hydrogen-substituted film;
A drying apparatus for drying the hydrogen-substituted film and solid electrolyte film containing the solid electrolyte;
A facility for producing a solid electrolyte film, comprising: The contact device comprises an other surface contact device for contacting a solution having a lower proton concentration than the liquid with the other surface of the precursor film;
The other surface heating device that heats the other surface side of the precursor film and generates a hydrogen substitution film in which the cation species are replaced with hydrogen atoms from the precursor film; and
The solid electrolyte film manufacturing facility according to claim 14, comprising: A casting film forming apparatus for casting a dope containing a polymer that is a precursor of a solid electrolyte and an organic solvent on a traveling support to form a casting film;
A stripping device for stripping the cast film as the precursor film from the support;
16. The facility for producing a solid electrolyte film according to claim 14 or 15, characterized by comprising:   A solid electrolyte film produced by the method for producing a solid electrolyte film according to claim 1. A solid electrolyte film according to claim 17,
An anode electrode that is provided in close contact with one surface of the solid electrolyte film and generates the proton from a hydrogen atom-containing substance supplied from the outside;
A cathode electrode that is provided in close contact with the other surface of the solid electrolyte film, and synthesizes water composed of the proton that has passed through the solid electrolyte film and a gas supplied from the outside;
An electrode membrane composite comprising:   19. An electrode membrane composite according to claim 18, and an assembly that is provided in contact with an electrode of the electrode membrane composite and delivers electrons to and from the anode electrode and the cathode electrode. Fuel cell.

Images