Polymer having protonic acid group, film and manufacturing method, ion conductive membrane, solid electrolyte membrane, ion exchange membrane, diaphragm for redox flow device, secondary battery, water electrolysis device, and fuel cell

Abstract

[Problem] The present invention addresses the problem of providing: a polymer which contains a wholly aromatic polyamide, a wholly aromatic polyamide imide, and / or a wholly aromatic polyimide, and which achieves both excellent mechanical properties and high affinity for water and ions; and a film and a method for manufacturing the film. [Solution] Provided is a polymer which contains a wholly aromatic polyamide, a wholly aromatic polyamide imide, and / or a wholly aromatic polyimide, wherein: the number of repeating units of the wholly aromatic polyamide, the wholly aromatic polyamide imide, and / or the wholly aromatic polyimide is 80% or more with respect to the number of all repeating units in the polymer; a protonic acid group A in which the pKa of Ph-A is -3.0 to 2.0 inclusive and / or a group of a conjugate base thereof is contained in the repeating units of the wholly aromatic polyamide, the wholly aromatic polyamide imide, and / or the wholly aromatic polyimide; and ηinh is 1.25 dL / g to 8.00 dL / g inclusive.

Description

Polymers having protonic acidic groups, films and manufacturing methods, ion conductive membranes, solid electrolyte membranes, ion exchange membranes, diaphragms for redox flow devices, secondary batteries, water electrolysis devices, fuel cells

[0001] The present invention relates to a polymer having a protonic acidic group, a film, a method for producing the same, and the like.

[0002] In recent years, the development of solid electrolytes and ion-conducting materials has progressed due to the increasing popularity of secondary batteries and electrolysis technologies. For secondary batteries and electrolysis applications, ion-conducting materials must have high ion conduction efficiency, enable ion conduction between positive and negative electrodes, prevent short circuits due to contact between the electrodes, and be less vulnerable to deformation due to bending or pressure. They must also be thin and maintain strength. Polymer solid electrolytes have recently attracted attention as a solution to these issues. Because ionic conductivity is closely related to polymer segment motion, research has focused on polymers with low glass transition temperatures due to flexible polymer structures, branching, and low molecular weight. However, flexible and / or branched polymers also have reduced elastic modulus and heat resistance, which can impair the ability to suppress contact between positive and negative electrodes. Furthermore, polymers containing ionic functional groups, such as Nafion®, have traditionally been used as materials with excellent affinity for water and ions. However, these materials often have highly flexible main chain structures, such as polyolefins, which pose challenges in terms of mechanical strength. Furthermore, when the gases present in the system (hydrogen gas and oxygen gas) need to be separated, such as in fuel cells and water electrolysis applications, a low gas permeability coefficient for the solid electrolyte membrane is important in addition to the above-mentioned properties.

[0003] Examples of resin materials with excellent mechanical properties and gas barrier properties include aromatic polyamides, aromatic polyamideimides, and aromatic polyimides. However, because these polymers are largely composed of nonpolar and hydrophobic hydrocarbon-based aromatic structures, they are unable to exhibit excellent performance in applications requiring high affinity with water or ionic chemical species. For example, aromatic polyamides with sulfonic acid groups introduced into the repeating units have been reported to improve hydrophilicity. As a method for polymerizing diamine monomers and dicarboxylic acid monomers, for example, Patent Document 1 discloses a method for polymerizing sulfonic acid group-containing polyamides in the presence of a phosphite ester and pyridine, while Non-Patent Documents 1 and 2 disclose a method for polymerizing sulfonic acid group-containing aromatic polyamides by heating diamine monomers and dicarboxylic acid monomers in the presence of sulfuric acid or sulfurous acid. Furthermore, as a method for polymerizing diamine monomers and dicarboxylic acid dichloride monomers that easily yields polymers with a high degree of polymerization, for example, Non-Patent Document 3 discloses a method for polymerizing sulfonic acid group-containing aromatic polyamides in the presence of a large amount of lithium chloride as a solubilizing agent. Furthermore, as a polyamide having a similar structure to these, a polymer containing a sulfone group is disclosed in Patent Document 2. Furthermore, Patent Document 3 discloses a polymer electrolyte membrane containing a fluorine-based polymer and a hydrocarbon-based polymer, which has excellent gas barrier properties and chemical stability.

[0004] Japanese Patent Laid-Open No. 7-258407 Japanese Patent Laid-Open No. 2008-127493 Japanese Patent Laid-Open No. 2014-232663

[0005] J. Polym. Sci. Polym. Chem. 1979, 17, 3535-3542. J. Polym. Sci. Polym. Chem. 1979, 17, 3519-3533. J. Polym. Sci. Polym. Chem. 1989, 27, 3745-3757.

[0006] However, in all of the methods for producing sulfonic acid-containing polyamides disclosed in Patent Document 1 and Non-Patent Documents 1 to 3, the degree of polymerization of the resulting polymer remains at a maximum of 1.2 dL / g or less, and sufficient mechanical strength may not be obtained when used as a material for a film, etc. Furthermore, the polymer having sulfonic groups disclosed in Patent Document 2 has a polar structure but does not have hydrogen bonding or ion-exchangeable functional groups, and therefore has poor performance in terms of hydrophilicity and ionic conductivity. The electrolyte membrane disclosed in Patent Document 3 has difficulty achieving both gas barrier properties and strength.

[0007] The present invention aims to provide a polymer containing a wholly aromatic polyamide, wholly aromatic polyamideimide, and / or wholly aromatic polyimide having a high degree of polymerization and a protonic acid group with a low acid dissociation constant, and a method for producing the same, thereby achieving a film that simultaneously exhibits excellent mechanical properties, gas barrier properties, and high affinity for water and ions.

[0008] The present invention, which has been made to achieve the above object, is characterized as follows: (1) A polymer containing a wholly aromatic polyamide, a wholly aromatic polyamideimide, and / or a wholly aromatic polyimide, in which the number of repeating units of the wholly aromatic polyamide, the wholly aromatic polyamideimide, and / or the wholly aromatic polyimide is 80% or more of the total number of repeating units in the polymer, and a pK ａ a protonic acidic group A (functional group A) and / or a group of its conjugate base, in which η is -3.0 or more and 2.0 or less, is contained in a repeating unit of a wholly aromatic polyamide, a wholly aromatic polyamideimide and / or a wholly aromatic polyimide; ｉｎｈ(2) A polymer having a Young's modulus of 1.25 dL / g or more and 8.00 dL / g or less. (2) The polymer according to (1), wherein the number of repeating units containing functional group A and / or its conjugate base group in the polymer is 10% or more and 100% or less of the number of repeating units of wholly aromatic polyamide, wholly aromatic polyamideimide, and / or wholly aromatic polyimide in the polymer. (3) The polymer according to (2), wherein the functional group A is a sulfonic acid group and / or a phosphonic acid group. (4) A film containing the polymer of (1) to (3) as a main component. (5) The film according to (4), having a Young's modulus of 5.0 GPa or more and 15.0 GPa or less when the film has a thickness of 25 μm. (6) A hydrogen gas permeability coefficient of 1.0×10 at 25°C and a relative humidity of 10%. －１１ cm ３ cm / (s cm ２ ・cmHg) or more 2.0 x 10 －９ cm ３ cm / (s cm ２ 1. The film according to (4) or (5), having a viscosity of 0.1 MPa or less (cmHg). (7) The film according to (4) to (5), wherein, when the film is made to have a thickness of 25 μm, the film weight increases by 5% by weight or more and 150% by weight or less when immersed in water at room temperature for 20 minutes. (8) A method for producing the polymer according to (1), wherein a Brønsted base is added to a monomer containing a functional group A and / or a group of its conjugate base, followed by polycondensation to obtain a polymer, wherein the monomers are an aromatic diamine and an aromatic dicarboxylic acid dichloride. (9) An ion conductive membrane comprising the polymer according to any one of (1) to (3). (10) A solid electrolyte membrane comprising the polymer according to any one of (1) to (3). (11) An ion exchange membrane comprising the polymer according to any one of (1) to (3). (12) A diaphragm for a redox flow device comprising the polymer according to any one of (1) to (3). (13) A secondary battery comprising the ion conductive membrane according to (8). (14) A water electrolysis device comprising the solid electrolyte membrane according to (9). (15) A fuel cell comprising the solid electrolyte membrane according to (9).

[0009] According to the present invention, it is possible to provide a polymer and a film thereof that have both excellent mechanical properties and high water / ion affinity. Therefore, the polymer and film of the present invention can be suitably used as materials and / or components for, in particular, ion-conducting membranes, ion-exchange membranes, solid electrolyte membranes, and the like.

[0010] The polymer of the present invention includes a wholly aromatic polyamide, a wholly aromatic polyamideimide, and / or a wholly aromatic polyimide. Here, the wholly aromatic polyamide, the wholly aromatic polyamideimide, and the wholly aromatic polyimide are polymers in which aromatic groups are directly linked by amide bonds, amide and imide bonds, and imide bonds, respectively. By including the wholly aromatic polyamide, the wholly aromatic polyamideimide, and / or the wholly aromatic polyimide, the polymer can have excellent mechanical properties.

[0011] The polymer of the present invention is characterized in that the number of repeating units of wholly aromatic polyamide, wholly aromatic polyamideimide, and / or wholly aromatic polyimide contained in the polymer is 80% or more of the total number of repeating units in the polymer. If the number of repeating units of wholly aromatic polyamide, wholly aromatic polyamideimide, and / or wholly aromatic polyimide is less than the above range, the rigidity and packing of the polymer structure may decrease, and the mechanical properties may be deteriorated.

[0012] The polymer of the present invention has an acid dissociation constant (pK ａ The polyimide is characterized in that the repeating unit of the wholly aromatic polyamide, wholly aromatic polyamideimide and / or wholly aromatic polyimide contains a protonic acid group A and / or a group of its conjugate base, in which the pK ａ is the value in water at 25°C. The proton acid group is an acidic functional group in the Bronsted definition, and is the one that does not have H ＋ It refers to a functional group that can give the pK of Ph-A. ａIt is preferable that the polymer contains a protonic acid group A having a molecular weight of -2.8 or more and 1.5 or less. The functional group A is not limited to a specific functional group as long as it satisfies the above requirements, but from the viewpoint of ease of introduction and stability, it is preferable that it is, for example, a sulfonic acid group and / or a phosphonic acid group. Furthermore, when it exists as a group of a conjugate base, it may contain a counter ion. When the polymer of the present invention is used in an application for conducting a specific cation, it is particularly preferable to use that cation as a counter ion from the viewpoint of increasing the number of carriers. For example, when the polymer is used as an electrolyte member for a secondary battery using lithium, it is preferable to use Li as a counter cation. ＋ There are no limitations on the counter ion, but it is preferably a cation having a valence equal to or less than the valence of the conjugate base. By including the functional group A and / or a group of its conjugate base, H ＋ The affinity with water and ionic species such as cations and alkali metal ions can be improved, and excellent hydrophilicity and ionic affinity can be obtained. As a polymer satisfying the above characteristics, the wholly aromatic polyamide and / or wholly aromatic polyamideimide of the present invention preferably contains a structural unit represented by the following chemical formula (I): Chemical formula (I):

[0013]

[0014] Ar １ , Ar ２ is any aromatic group, and at least one of them contains the functional group A. Wholly aromatic polyamides that satisfy the above characteristics include, for example, structures such as those shown in the following chemical formulas (II) to (III). However, the structures shown in chemical formulas (II) to (III) are merely examples and do not limit the structure of the wholly aromatic polyamide in the present invention. Chemical formula (II):

[0015]

[0016] Ar ３ is any aromatic group, R １ represents —H, an aliphatic group having 1 to 5 carbon atoms, —CF ３ , -CCl ３ , -OH, -F, -Cl, -Br, -OCH ３, a silyl group, an aromatic group, or a group containing the functional group A. １ does not contain the functional group A, Ar ３ contains the functional group A. Chemical formula (III):

[0017]

[0018] Ar ４ is any aromatic group. ２ , R ３ represents —H, an aliphatic group having 1 to 5 carbon atoms, —CF ３ , -CCl ３ , -OH, -F, -Cl, -Br, -OCH ３ , a silyl group, an aromatic group, or a group containing the functional group A. ４ is -O-, -C(CF ３ ) ２ -, a sulfone group, or a fluorene group, provided that R ２ , R ３ does not contain the functional group A, Ar ４ contains the functional group A.

[0019] The wholly aromatic polyamideimide of the present invention may be, for example, one in which both an amide group and an imide group exist in the structural unit as shown in chemical formula (IV), or one in which a diimide as shown in chemical formula (V) is copolymerized with the wholly aromatic polyamide structure as described above, and either case is acceptable in the present invention. Furthermore, the wholly aromatic polyimide of the present invention may have a structure as shown in chemical formula (V). Chemical formula (IV):

[0020]

[0021] Ar ５ is any aromatic group, R ５ represents —H, an aliphatic group having 1 to 5 carbon atoms, —CF ３ , -CCl ３ , -OH, -F, -Cl, -Br, -OCH ３ , a silyl group, an aromatic group, or a group containing the functional group A. ５ does not contain the functional group A, Ar ５ contains the functional group A. Chemical formula (V):

[0022]

[0023] Ar ６ is any aromatic group, R ６ represents —H, an aliphatic group having 1 to 5 carbon atoms, —CF ３ , -CCl ３ , -OH, -F, -Cl, -Br, -OCH ３ , a silyl group, an aromatic group, or a group containing the functional group A. ６ does not contain the functional group A, Ar ６ contains the functional group A.

[0024] The polymers of the present invention have an inherent viscosity (η ｉｎｈ ) must be 1.25 dL / g or more and 8.00 dL / g or less. ｉｎｈ is more preferably 1.30 dL / g or more and 8.00 dL / g or less, and even more preferably 1.35 dL / g or more and 8.00 dL / g or less. ｉｎｈ By setting η within the above range, the entanglement and interaction between molecular chains increases, which improves the mechanical strength and handling properties when made into a film, thereby reducing the occurrence of breakage or fracture. ｉｎｈ In order to make the value fall within the above range, it is preferable to obtain the polymer by the production method of the present invention in which a diamine monomer and a dicarboxylic acid dichloride monomer are polycondensed in the presence of a Bronsted base.

[0025] In the polymer of the present invention, the number of repeating units containing the functional group A and / or its conjugate base group is preferably 10% to 100% of the number of repeating units of the wholly aromatic polyamide, wholly aromatic polyamideimide, and / or wholly aromatic polyimide. It is more preferably 20% to 100%, and even more preferably 40% to 100%. If the numerical proportion of repeating units containing the functional group A and / or its conjugate base group is less than 10%, the contribution of the functional group A is reduced, and affinity with water and ions may not be achieved. To achieve the numerical proportion of repeating units containing the functional group A within the above range, it is preferable to use a monomer containing the functional group A and adjust the amount of monomer used in polymerization so that the stoichiometric proportion falls within the above range. One embodiment of the present invention is a film containing the polymer of the present invention as a main component. Here, "main component" refers to the component contained in the largest amount in the film. While the component amount is not particularly limited, a component amount of preferably 80% by weight or more, more preferably 90% by weight or more, relative to the entire film can better exhibit the high rigidity inherent in the polymer of the present invention. Furthermore, the film primarily composed of the polymer of the present invention preferably has a thickness of 1 μm to 200 μm, more preferably 1 μm to 150 μm, and even more preferably 30 μm to 80 μm. The film primarily composed of the polymer of the present invention preferably has a Young's modulus of 5.0 GPa to 15.0 GPa when the thickness is 25 μm. By controlling the Young's modulus within the above range, the mechanical strength of the film is increased, making it less susceptible to breakage or rupture. To achieve the Young's modulus within the above range, the polymer preferably contains a wholly aromatic polyamide, a wholly aromatic polyamideimide, and / or a wholly aromatic polyimide. The film primarily composed of the polymer of the present invention can achieve high mechanical properties by using a wholly aromatic polyamide, a wholly aromatic polyamideimide, and / or a wholly aromatic polyimide as the main component of the film and controlling the Young's modulus within the above range, and can therefore achieve, for example, a puncture strength per unit thickness of 0.3 to 3.0 N / μm.When the puncture strength is within the above range, short circuits between electrodes due to unevenness on the electrode surface, contaminants, deposited metal dendrites, etc. can be preferably prevented when used in secondary batteries or electrolysis applications. The puncture strength is more preferably 0.5 to 3.0 N / μm. The film containing the polymer of the present invention as a main component has a hydrogen gas permeability coefficient of 1.0 × 10 at 25°C and a relative humidity of 10%. －１１ cm ３ cm / (s cm ２ ・cmHg) or more 2.0 x 10 －９ cm ３ cm / (s cm ２ It is preferable that the hydrogen gas permeability coefficient is 1.0×10 cmHg or less. －１１ cm ３ cm / (s cm ２ cmHg) or more than 1.0 x 10 －９ cm ３ cm / (s cm ２・cmHg or less. If the hydrogen gas permeability coefficient is smaller than the above range, material transport in the thickness direction of the membrane is retarded, which may result in an insufficient supply of hydrogen gas and oxygen gas necessary for the combustion reaction in a fuel cell, or in difficulty in extracting the hydrogen gas and oxygen gas generated in water electrolysis. If the hydrogen gas permeability coefficient is larger than the above range, direct reaction between hydrogen gas and oxygen gas is more likely to occur, which may result in reduced efficiency and durability and heat generation when used as a diaphragm for water electrolysis. To achieve a hydrogen gas permeability coefficient within the above range, the main component of the film is preferably the polymer described in the present invention, and the number of repeating units of the polymer containing the functional group A and / or its conjugate base group is preferably 10% to 100% of the number of repeating units of the wholly aromatic polyamide, wholly aromatic polyamideimide, and / or wholly aromatic polyimide, and more preferably the polymer is a wholly aromatic polyamide. The hydrogen gas permeability coefficient in the present invention can be measured by a differential pressure steady-state method. The differential pressure steady-state method is a measurement method for estimating the gas permeability of membrane-like molded articles with thicknesses ranging from several micrometers to several hundred micrometers, and is performed according to the following procedure. (1) A test piece with a known sample thickness and gas permeation area is used as a boundary. One side is supplied with a test gas at a constant pressure (high-pressure side), and the other side is evacuated (low-pressure side), creating a pressure difference. (2) After the gas permeation rate reaches a steady state, the evacuation is stopped. (3) While the test gas that has permeated the test piece is stored in the measuring tube, the elapsed time from the stop of the evacuation, i.e., the time from when the test gas begins to accumulate in the measuring tube, is measured, and this time is defined as the measurement time t. (4) The test gas in the measuring tube is introduced into a gas chromatograph using a carrier gas, and after component separation, the permeation rate of each component is quantified. (5) The permeation coefficient is calculated using the following formula: Gas permeation coefficient = (Q x K x L) / (P x A x t), where Q is the test gas permeation rate (cm ３ ) K: Cell constant, a value specific to the cell used L: Membrane thickness of the test piece (cm) P: Pressure difference (cmHg) A: Permeation area (cm ２ ) t: measurement time (sec) Display unit of permeability coefficient: cm ３ cm / s cm ２ ・cmHg.

[0026] When a film having a thickness of 25 μm and composed primarily of the polymer of the present invention is immersed in water at room temperature for 20 minutes, the film preferably experiences a weight increase of 5% to 150% by weight. If the weight increase of the film upon water immersion under the above conditions is less than 5% by weight, the affinity between the polymer and highly polar components may be reduced, resulting in reduced ion conductivity when used as an ion-conductive membrane or solid electrolyte. If the weight increase of the film upon water immersion under the above conditions is greater than 150% by weight, the film may experience reduced rigidity. The film composed primarily of the polymer of the present invention may be composed of a single polymer or a mixture of multiple polymers with different chemical structures, as long as the main component is a polymer having the aforementioned characteristics. Furthermore, the film may contain a different polymer other than wholly aromatic polyamide, wholly aromatic polyamideimide, and wholly aromatic polyimide. Examples of different polymers that can be contained in the film include, but are not limited to, polyester, polyethylene, polypropylene, polyolefin, polysiloxane, polyetherketone, and polysulfone. The film mainly composed of the polymer of the present invention may contain an organic-inorganic hybrid resin such as a thermosetting resin, an ultraviolet curing resin, a hydrolysis / condensation resin, or an alkoxysilane compound, or an electrolyte, for the purpose of improving rigidity and dimensional stability. Furthermore, an electrolyte may be included for the purpose of increasing ion conductivity or the amount of ions contained in the film. For example, in the case of lithium ions, an electrolyte such as LiPF ６ , LiAsF ６ , LiClO ４ , LiBF ４Examples of the electrolyte include lithium salts such as lithium ions, ... ２ ), aluminum oxide (Al ２ O ３ ), zinc oxide (ZnO), zirconium oxide (ZrO ２ ), titanium oxide (TiO ２ ), antimony oxide (Sb ２ O ３) and indium tin oxide (ITO). Furthermore, for the purpose of suppressing deterioration of the film obtained by drying the solution and solvent, the film may contain organic or inorganic pigments, dyes, or antioxidants. The film containing the polymer of the present invention as a main component may be a single film or a laminate film formed on at least one side of an electrode material or a porous substrate. When used as a laminate film with an electrode material, the electrode may be either a positive electrode or a negative electrode. For example, when used for a metal lithium negative electrode, forming the film of the present invention directly on the lithium negative electrode allows the film to function as a protective film, improving ionic conductivity and dendrite resistance. When used as a laminate film with a porous substrate, examples of the porous substrate include a porous membrane, a nonwoven fabric, or a porous membrane sheet made of a fibrous material, which may have through-holes. The resin constituting the porous substrate is preferably a resin that is electrically insulating, electrically stable, and stable to the electrolyte. Furthermore, from the viewpoint of imparting a shutdown function, the resin used is preferably a thermoplastic resin, and more preferably a thermoplastic resin with a melting point of 200°C or less. The term "shutdown function" refers to the ability of a lithium-ion battery to melt due to heat, thereby closing the porous structure and stopping ion migration and power generation when the battery generates abnormal heat. When the chemical structure and composition ratio of the polymer, film, and other components of the present invention need to be identified, the components can be separated using a combination of techniques such as redissolution, extraction, chromatography, distillation, liquid separation, and reprecipitation, and analyzed using a combination of nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FT-IR), mass spectrometry (MS), elemental analysis, single crystal structure analysis, and the like.

[0027] The method for producing a polymer of the present invention is characterized by adding a Brønsted base to a monomer containing the functional group A and / or its conjugate base group, and then polycondensing a diamine monomer and a dicarboxylic acid dichloride monomer to obtain a polymer. Adding the Brønsted base allows the functional group A to remain in the state of its conjugate base during the polymerization reaction, thereby suppressing polymerization termination due to side reactions or reduced solubility and allowing for the production of a high-molecular-weight polymer. While there is no limit to the amount of Brønsted base added, it is preferably 50 mol % or more, and more preferably 100 mol % or more, relative to the functional group A. Furthermore, while there is no limit to the chemical species of the Brønsted base added, it is preferable to use a secondary amine and / or a tertiary amine in terms of affinity with the solvent and the polymer to be produced and removability, and it is more preferable to use a tertiary amine whose side chain is an alkyl group having from 1 to 5 carbon atoms.

[0028] The method for producing the polymer and film of the present invention will be explained below using a wholly aromatic polyamide as an example, but the present invention is not limited thereto.

[0029] Various known methods, such as solution polymerization and precipitation polymerization, can be used to obtain wholly aromatic polyamides. For example, when polymerizing aromatic polyamides by solution polymerization, dicarboxylic acid dichloride and diamine can be used as raw materials and reacted at low temperatures in an aprotic solvent containing a Bronsted base. Here, the aprotic solvent refers to a polar solvent that does not have proton (hydrogen ion) donating properties, such as N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylisobutyramide, 3-methoxy-N,N-dimethylpropanamide, tetrahydrofuran, γ-butyrolactone, ethyl acetate, acetonitrile, dimethylformamide, and dimethyl sulfoxide. To prevent deactivation of the dicarboxylic acid dichloride, the water content of the solvent used in polymerization is preferably 500 ppm or less (by mass, hereinafter), and more preferably 200 ppm or less. Since an equal molar ratio of dicarboxylic acid dichloride to diamine tends to produce an ultrahigh molecular weight polymer, it is preferable to adjust the molar ratio so that one is 96.0 to 99.8%, more preferably 96.0 to 99.0%, of the other. When polymerization is carried out at this molar ratio, the diamine will be in excess relative to the acid dichloride, resulting in amino terminal functional groups. Furthermore, while the polymerization reaction of wholly aromatic polyamides is exothermic, it is preferable to keep the solution temperature below 40°C during polymerization. Temperatures above 40°C can cause side reactions and prevent the degree of polymerization from increasing sufficiently. It is more preferable to keep the solution temperature below 30°C during polymerization. When dicarboxylic acid dichloride and diamine are used as raw materials, hydrogen chloride is by-produced as the reaction progresses, resulting in a highly acidic solution of the resulting wholly aromatic polyamide. This solution is highly corrosive, and if left as is, it can corrode components such as metal substrates used in the production process of molded articles and films, making them unusable. Methods for removing the by-produced hydrogen chloride include a method in which hydrogen chloride is neutralized and removed by adding a neutralizing agent during polymerization, a method in which the polymer is precipitated and isolated, etc. When hydrogen chloride is neutralized and removed during polymerization, for example, a method in which hydrogen chloride is neutralized with an inorganic neutralizing agent such as lithium carbonate, calcium carbonate, or calcium hydroxide can be used.When neutralizing with an inorganic neutralizing agent, the solution contains inorganic salts (e.g., lithium chloride) produced by the neutralization reaction. These inorganic salts ionize in the solvent and coordinate with the amide groups of the wholly aromatic polyamide, acting as a dissolution aid in the solvent and thus improving the pot life of the solution and suppressing polymer aggregation during molding. However, because a washing step to remove the inorganic salt is required during the molding process, this method may not be usable depending on the dimensions of the molded body and / or film and the manufacturing process. Furthermore, when isolating the polymer by precipitation, the polymer solution obtained by solution polymerization can be mixed with a large amount of a poor solvent such as water to precipitate the polymer as a solid, and then separated from the solution by filtration or other methods to separate the polymer and hydrogen chloride. The isolated polymer can be redissolved in the aforementioned aprotic solvent to obtain a solution. Precipitating the polymer and separating it from hydrogen chloride eliminates the neutralization product produced by the reaction between the neutralizing agent and hydrogen chloride, thereby reducing the amount of impurities remaining in the molded body or film. Methods for introducing the functional group A into the aromatic polyamide of the present invention include polymerizing an aromatic polyamide using a monomer that has already been substituted with the functional group A as a starting material, or polymerizing a wholly aromatic polyamide starting material and then introducing the functional group A. When introducing the functional group into a wholly aromatic polyamide, a method of derivatizing the functional group A using a leaving group such as -H or a halogen group introduced on the aromatic as the starting point can be used. However, depending on the functional group conversion reaction used, poor regioselectivity may result in a structure different from the intended target, or insufficient reactivity may result in a low introduction rate of the functional group A. For this reason, a method using a monomer that already contains the functional group A as a starting material is preferred. When polymerization is carried out using a monomer containing the functional group A as a starting material, H dissociates from the functional group A. ＋ However, the functional group A may inhibit the reaction or have low solubility in a polymerization solvent such as an aprotic solvent, resulting in a low degree of polymerization of the resulting polymer. For this reason, in the present invention, it is preferable to carry out polymerization by adding the above-mentioned Bronsted base. By making the functional group A into a conjugate base state in the polymerization step, reaction inhibition and a decrease in solubility can be suppressed, and a polymer with a high degree of polymerization can be obtained.

[0030] As a method for introducing the conjugate base of the functional group A into the polymer of the present invention, a polymer containing the functional group A is polymerized by the above method, and then a basic reagent is allowed to act on the polymer to introduce the H in the functional group A. ＋ Here, the basic reagent is a compound having a pK of the conjugate acid generated from the basic reagent. ａ is the pK of Ph-A ａ Preferably, the reagent has a higher basicity, such as a metal hydride and / or a metal carbonate. Specific examples include, but are not limited to, lithium hydride, sodium hydride, lithium carbonate, and sodium carbonate. When the conjugate base of the functional group A is introduced into the polymer by this method, a metal cation is also contained as its counter ion. Therefore, when the polymer of the present invention is used as a cation-conducting material, it is particularly preferable to use a basic reagent containing the target cation, since this can increase the amount of carriers contained in the film.

[0031] The film of the present invention can be obtained by dissolving the polymer obtained as described above in a solvent and applying the solution to a substrate to form a film. The solvent is not limited as long as it dissolves the polymer, but an aprotic solvent is preferred. Furthermore, this solution may contain the aforementioned resin, electrolyte, particles, etc., for the purpose of improving the film properties. Examples of film formation methods include a dry-wet method in which a pre-drying step, a washing step in a wet bath, and then a heat treatment are performed; a dry method in which solvent drying is performed without a washing step; and a wet method in which a film is introduced into a wet bath without a solvent drying step and then a heat treatment are performed. Any of these methods may be used to form a film, but a dry method is preferred from the standpoint of process simplicity and processability, which allows a film to be formed on an object during device manufacturing.

[0032] The coating method on the substrate can be selected from known methods such as die coating, roller coating, wire bar coating, and gravure coating. The substrate may be made of any material that is not corroded by the raw material solution and does not deform or denature when heated for solvent drying, such as a glass plate, thin glass film, resin film, metal plate, quartz plate, or silicon wafer. The substrate surface may be smooth or have a fine structure. Methods for solvent drying include, but are not limited to, hot air, infrared irradiation, and microwave irradiation. The drying temperature is preferably 50 to 400°C. From the viewpoint of improving thermal dimensional stability, it is more preferable for the drying process to include a step in the temperature range of 150 to 400°C. To prevent surface roughening due to rapid solvent evaporation, it is even more preferable to perform preliminary drying at 50 to 200°C, followed by stepwise solvent drying at 200 to 400°C. When the polymer is to be a wholly aromatic polyamideimide and / or a wholly aromatic polyimide, a precursor of the wholly aromatic polyamideimide and / or a wholly aromatic polyimide can be obtained by polymerization in the same manner as described above, except that some or all of the acid dichloride is replaced with a tetracarboxylic dianhydride. This precursor can be isolated and redissolved in the same manner as described above to obtain a precursor solution. This precursor solution can be formed into a film by the aforementioned film-forming method, whereby a ring-closure reaction proceeds during the heating step during film formation, resulting in a wholly aromatic polyamideimide film and / or a wholly aromatic polyimide film. Furthermore, as described above, the film of the present invention may contain organic-inorganic hybrid resins such as thermosetting resins, UV-curable resins, hydrolysis / condensation resins, and alkoxysilane compounds, inorganic or organic particles, organic or inorganic pigments or dyes, antioxidants, etc., which may be added and dispersed during the preparation of the polymer solution, or may be incorporated into the polymer by adding them to the solvent before polymerization.

[0033] The polymers and films of the present invention can be suitably used as battery separator films, polymer solid electrolytes, ion separation membranes, diaphragms for redox flow devices and materials therefor, and can also be installed in water electrolyzers, secondary batteries, vehicles, aircraft, electronic devices, and the like. Here, redox flow devices refer to water electrolysis devices and fuel cells, and by incorporating the polymers of the present invention into the diaphragms, high proton conductivity and gas barrier properties can be achieved. Furthermore, the term "vehicles" refers to automobiles, motorcycles, bicycles, electric wheelchairs, electric carts, and the like, which are equipped with secondary batteries as part of their power mechanisms. The term "aircraft" refers to manned aircraft, unmanned aircraft, drones, and the like, which are equipped with secondary batteries as part of their propulsion mechanisms. The term "electronic devices" refers to all devices equipped with secondary batteries as power storage devices, including electro-optical devices and information terminal devices. Furthermore, the polymers of the present invention are preferably used as raw materials for films, but can also be suitably used as raw materials for fibers, molded articles, and the like.

[0034] The present invention will be described in more detail below with reference to examples.

[0035] The films used to evaluate the physical properties of the polymers and films of the present invention were evaluated according to the following methods.

[0036] First, the sample solution was cast into a film on a glass plate using an applicator. The temperatures of the sample solution, glass plate, and casting atmosphere were all room temperature. The cast thickness was adjusted so that the film thickness after solvent drying would be 25 μm. Next, the glass plate was placed in a hot air oven and dried at Tb-50°C for 30 minutes, and then at Tb+100°C for 5 minutes, where Tb is the boiling point of the aprotic solvents constituting the solution (in the case of a mixed solvent, the boiling point of the solvent with the highest boiling point among the solvents contained in 30% by mass or more of the total solvent amount).

[0037] In the present invention, the methods for measuring physical properties and evaluating effects were as follows.

[0038] (1) η ｉｎｈA blank solution was prepared by dissolving LiBr in NMP to a concentration of 2.5 wt %. A polymer was added to this blank solution to a polymer concentration of 0.5 g / dL, and the polymer was completely dissolved by maintaining the temperature at 60°C to prepare a sample solution. The flow time of this sample solution and the blank solution in an Ubbelohde viscometer was measured in a water bath at 30°C, and η was calculated from the following equation: ｉｎｈ was calculated. ｉｎｈ (dL / g)=ln(t / t ０ ) / c where t is the flow time of the polymer solution (sec), t ０ is the flow time (sec) of the blank solution, and c is the solution concentration (g / dL). (2) Young's modulus The produced film was cut into a sample having a width of 10 mm and a length of 150 mm, and a tensile test was carried out using a Robot Tensilon AMF / RTA-100 (manufactured by Orientec Co., Ltd.) under the conditions of a chuck distance of 50 mm, a tensile speed of 300 mm / min, a temperature of 23°C, and a relative humidity of 65%, and the Young's modulus was determined from the obtained load-elongation curve.

[0039] The test was carried out in both the longitudinal direction (cast direction) and the transverse direction (cross direction) of the film, and the average value of five tests was calculated for each direction. Table 1 shows the higher Young's modulus value in both directions.

[0040] (3) Hydrogen Gas Permeability Coefficient The hydrogen gas permeability coefficient of each sample film was measured at 25° C. and 50% RH under the following conditions: The gas permeability coefficient was calculated as the average value of three tests.

[0041] Apparatus: Differential pressure gas permeability measurement system GTR-30AX (manufactured by GTR Tech Co., Ltd.) Temperature x relative humidity: 25°C x 10% RH Test gas: hydrogen gas Test gas pressure: total pressure including water vapor was 101.3 kPa (atmospheric pressure) When measuring at 25°C and 10% RH, the partial pressure of each measured gas was 100.0 kPa Gas permeation area: 3.14 cm2 (circular sample with a diameter of 2.0 cm) Number of measurements: 3 (measured using the same sample).

[0042] (4) Weight increase rate due to moisture absorption At 25°C and 65% RH, the sample film was cut into a square of 5 cm length x 5 cm width to obtain a sample piece, and the weight was measured to determine the dry weight (w ０ ) was obtained. This sample piece was completely immersed in pure water and left to stand at 25°C for 20 minutes. Thereafter, the sample piece was taken out of the pure water, and the water droplets adhering to the surface were completely wiped off with Kimwipes®, and the weight was measured to obtain the weight (w) when wet. From the obtained weights when dry and when wet, the moisture content was calculated using the following formula: Weight increase rate due to moisture absorption (%) = 100 (w - w ０ ) / w The same measurement was repeated to determine the weight gain due to hydration of five sample pieces, and the average value was used as the weight gain due to hydration of the sample film. (5) Puncture Strength Using a compression tester KES-G5 (manufactured by Kato Tech Co., Ltd.), measurements were taken at 23°C in accordance with JIS-Z1707 (1997), except that the needle penetration speed was 2 mm / sec. The maximum load at which the sample ruptured was read and divided by the thickness of the sample before the test to determine the puncture strength (N / μm). This measurement was performed five times, and the average value was used as the puncture strength of the sample film. (6) Cation Affinity A sample film cut to a weight of 5.0 g was immersed in a saturated lithium carbonate aqueous solution at room temperature for 1 hour. The sample film was then removed and immersed in pure water for 10 minutes to remove free metal salts present in the film. The sample film was removed from the pure water and dried, and then weighed, sulfuric acid was added to the sample film, and the film was carbonized by heating. The ash was decomposed by heating with sulfuric acid, nitric acid, hydrofluoric acid, and perchloric acid, and dissolved in dilute nitric acid to a constant volume. The solution was decomposed with concentrated sulfuric acid to obtain a homogeneous solution. This solution was subjected to atomic absorption spectrometry (calibration curve method) using a Hitachi High-Tech Science ZA-3300 atomic absorption spectrophotometer to determine the Li content of the sample. ＋ The content was measured as a weight percent based on the total weight of the sample film. ＋When the measured content was less than 0.1% by mass, it was evaluated as D, when it was 0.1% by mass or more but less than 0.3% by mass, it was evaluated as B, and when it was 0.3% by mass or more, it was evaluated as A. (Example 1) 1,4-phenylenediamine-4-sulfonic acid (PDSA) corresponding to 100 mol % of the total amount of diamines and triethylamine corresponding to 50 mol % of the total amount of diamines were dissolved in dehydrated DMAc (boiling point 165°C) under a nitrogen stream, and the liquid temperature was cooled to 5°C in an ice-water bath. While the system was maintained in the ice-water bath under a nitrogen stream, 2-chloroterephthaloyl chloride (CTPC) corresponding to 99 mol % of the total amount of diamines was added over 30 minutes, and after the entire amount was added, the mixture was stirred for about 1 hour to polymerize an aromatic polyamide. The obtained polymerization solution was added to a large amount of t-butanol while stirring to solidify the polymer into a fibrous form, which was then crushed in a mixer for 5 minutes and dried in a hot air oven at 80°C for 1 hour and in a vacuum oven at 120°C for 12 hours, thereby forming a sulfonic acid group (-SO ３ An aromatic polyamide (polymer A) containing benzenesulfonic acid (H) was obtained as a powder. ａis -2.8. A solution was obtained by dissolving polymer A in DMAc to a polymer concentration of 10% by mass. The resulting solution was applied in the form of a film onto a glass plate support and dried in a hot air oven at 130°C for 10 minutes to obtain a self-supporting film. The film was then peeled off from the support. The peeled film was then washed in a water bath for 15 minutes to extract the solvent. The resulting water-containing film was then heat-treated for 1 minute in a hot air oven at 280°C to obtain a 25 μm-thick film made of polymer A. Here, a Safety Oven SPH100 ​​(manufactured by Espec Corporation) was used as the hot air oven, and the oven was used 1 hour after the temperature display reached the set temperature with the open / close damper at 50%. The evaluation results of the obtained sample are shown in Table 1. (Example 2) After polymerizing an aromatic polyamide in the same manner as in Example 1, 50 mol % lithium carbonate relative to the total amount of diamine was added to the polymerization solution, heated to 60°C, and stirred for 1 hour. The resulting polymer solution was added to a large amount of t-butanol while stirring, solidifying the polymer into a fibrous form, and then pulverized in a mixer for 5 minutes to obtain a powder. The powder was stirred in a large amount of water and then filtered to remove neutralized salt components that were not associated with the polymer. The powder was then dried in a hot air oven at 80°C for 1 hour and in a vacuum oven at 120°C for 12 hours, thereby removing the conjugate base group of sulfonic acid (-SO) in the repeating unit. ３ － An aromatic polyamide (polymer B) containing a phosphonic acid group (-PO) in the repeating unit was obtained as a powder. Thereafter, a film of polymer B having a thickness of 25 μm was obtained in the same manner as in Example 1. The evaluation results of the obtained sample are shown in Table 1. (Example 3) An aromatic polyamide (polymer B) containing a phosphonic acid group (-PO) in the repeating unit was obtained in the same manner as in Example 1, except that p-(2,5-diaminophenyl)phosphonic acid in an amount corresponding to 100 mol % based on the total amount of diamine was added instead of PDSA in an amount corresponding to 100 mol % based on the total amount of diamine. ３ H ２ An aromatic polyamide (polymer C) containing phenylphosphonic acid (Ph-A) and a film of polymer C having a thickness of 25 μm were obtained. The evaluation results of the obtained sample are shown in Table 1. Here, the pK ａis 1.9. p-(2,5-diaminophenyl)phosphonic acid was synthesized according to a known method (Nature Communications, 2022, 13, 7123.). (Example 4) A polymer having a sulfonic acid group (-SO) in the repeating unit was prepared in the same manner as in Example 1, except that PDSA corresponding to 80 mol % and 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFMB) corresponding to 20 mol % of the total amount of diamine were added instead of PDSA corresponding to 100 mol % of the total amount of diamine. ３ An aromatic polyamide (polymer D) containing sulfonic acid groups (-SOH) and a film of polymer D having a thickness of 25 μm were obtained. The evaluation results of the obtained sample are shown in Table 1. (Example 5) The same procedure as in Example 1 was carried out except that PDSA corresponding to 60 mol % and TFMB corresponding to 40 mol % of the total amount of diamine were added instead of PDSA corresponding to 100 mol % of the total amount of diamine. ３ An aromatic polyamide (polymer E) containing sulfonic acid groups (-SOH) and a film of polymer E having a thickness of 25 μm were obtained. The evaluation results of the obtained sample are shown in Table 1. (Example 6) The same procedure as in Example 1 was carried out except that PDSA corresponding to 40 mol % and TFMB corresponding to 60 mol % of the total amount of diamine were added instead of PDSA corresponding to 100 mol % of the total amount of diamine. ３ An aromatic polyamide (polymer F) containing a sulfonic acid group (-SOH) and a film made of polymer F having a thickness of 25 μm were obtained. The evaluation results of the obtained sample are shown in Table 1. (Example 7) The same procedure as in Example 1 was carried out except that PDSA corresponding to 20 mol % and TFMB corresponding to 80 mol % of the total amount of diamine were added instead of PDSA corresponding to 100 mol % of the total amount of diamine. ３An aromatic polyamide (polymer G) containing sulfonic acid groups (-SOH) and a film of polymer G having a thickness of 25 μm were obtained. The evaluation results of the obtained sample are shown in Table 1. (Example 8) The same procedure as in Example 1 was carried out except that PDSA corresponding to 10 mol % and TFMB corresponding to 90 mol % of the total amount of diamine were added instead of PDSA corresponding to 100 mol % of the total amount of diamine. ３ An aromatic polyamide (polymer H) containing a sulfonic acid group (-SO H) in the repeating unit was obtained. The evaluation results of the obtained sample are shown in Table 1. (Example 9) The same procedure as in Example 1 was carried out except that PDSA corresponding to 5 mol % and TFMB corresponding to 95 mol % of the total amount of diamine were added instead of PDSA corresponding to 100 mol % of the total amount of diamine. ３ An aromatic polyamide (polymer I) containing sulfonic acid groups (-SO) in the repeating units was obtained. The evaluation results of the obtained sample are shown in Table 1. (Example 10) The same procedure as in Example 1 was repeated except that PDSA corresponding to 80 mol % and hexamethylenediamine corresponding to 20 mol % of the total amount of diamines were added instead of PDSA corresponding to 100 mol % of the total amount of diamines. ３ A polymer (Polymer J) containing methyl methyl acrylate (H) and a 25 μm-thick film composed of Polymer J were obtained. The evaluation results of the obtained sample are shown in Table 1. (Example 11) PDSA, which corresponds to 100 mol % of the total amount of diamines as diamines, was dissolved in dehydrated DMAc under a nitrogen stream, and the liquid temperature was cooled to 5° C. in an ice-water bath. While the system was maintained in the ice-water bath under a nitrogen stream, CTPC, which corresponds to 50 mol % of the total amount of diamines, and pyromellitic anhydride (PMDA), which corresponds to 49 mol %, were added thereto over 30 minutes. After the entire amount was added, the mixture was stirred for about 2 hours to polymerize polyamic acid.

[0043] The resulting solution was applied in the form of a film onto a glass plate support and dried in a hot air oven at 130°C for 10 minutes to ensure the film was self-supporting. The film was then peeled off from the support. The peeled film was then washed in a water bath for 15 minutes to extract the solvent and neutralized salts. The resulting hydrated film was then heat-treated in a hot air oven at 350°C for 2 minutes to imidize it, yielding a 25 μm-thick film of aromatic polyamideimide (Polymer K). The evaluation results of the resulting sample are shown in Table 1. (Example 12) PDSA, equivalent to 90 mol% of the total diamine amount, was dissolved in dehydrated NMP under a nitrogen stream, and the solution was cooled to 5°C in an ice-water bath. PMDA, equivalent to 99 mol% of the total diamine amount, was added to the system under a nitrogen stream and maintained in the ice-water bath over 30 minutes. After the entire amount was added, the mixture was stirred for approximately 2 hours to polymerize the polyamic acid.

[0044] The resulting polyamic acid solution was applied in the form of a film to a glass plate support and dried in a hot air oven at 130°C for 10 minutes to ensure the film was self-supporting. The film was then peeled off from the support. The peeled film was then washed in a water bath for 15 minutes to extract the solvent and neutralized salts. The resulting hydrated film was then heat-treated in a hot air oven at 350°C for 2 minutes to imidize it, yielding a 25 μm-thick film of aromatic polyimide (polymer L). The evaluation results of the resulting sample are shown in Table 1. (Comparative Example 1) A film of aromatic polyamide (polymer M) and polymer M with a thickness of 25 μm was obtained in the same manner as in Example 1, except that TFMB was added in an amount equivalent to 100 mol% of the total diamine amount instead of PDSA in an amount equivalent to 100 mol% of the total diamine amount. The evaluation results of the resulting sample are shown in Table 1. Comparative Example 2 An aromatic polyamide (Polymer N) containing a carboxylic acid group (—COOH) in the repeating unit and a film made of Polymer N having a thickness of 25 μm were obtained in the same manner as in Example 1, except that 2,5-diaminobenzoic acid was added in an amount equivalent to 100 mol % of the total amount of diamines instead of PDSA in an amount equivalent to 100 mol % of the total amount of diamines. The evaluation results of the obtained sample are shown in Table 1. Here, the pK of benzoic acid corresponding to Ph-A was ａ is 4.2. (Comparative Example 3) An aromatic polyamide (polymer O) and a film made of polymer O having a thickness of 25 μm were obtained in the same manner as in Example 1, except that 200 mol % of lithium chloride based on the total amount of diamine was added instead of 50 mol % of triethylamine based on the total amount of diamine. The evaluation results of the obtained sample are shown in Table 1. (Comparative Example 4) An aromatic polyamide (polymer O) and a film made of polymer O having a thickness of 25 μm were obtained in the same manner as in Example 1, except that PDSA equivalent to 70 mol % and hexamethylenediamine equivalent to 30 mol % based on the total amount of diamine were added instead of PDSA equivalent to 100 mol % based on the total amount of diamine. ３ A polymer (polymer P) containing H) and a 25 μm thick film made of polymer P were obtained. The evaluation results of the obtained sample are shown in Table 1.

[0045] Comparative Example 5: Aquivion® P87S-SO 4 was added to 100 parts by mass of a potassium hydroxide-methanol solution having a potassium hydroxide concentration of 23% by mass. ２ 45 parts by mass of F (Sigma-Aldrich) pellets were added and heated at 80°C for 20 hours. The pellets were transferred to water at 60°C and stirred for 4 hours, and then stirred in hydrochloric acid (2N) at 60°C for 1 hour. The same procedure was repeated a total of 5 times. The pellets were then washed by stirring in ion-exchanged water for 1 hour to obtain a perfluorocarbon sulfonic acid resin.

[0046] Next, poly(2,6-dimethyl-1,4-phenylene oxide) (PPE, manufactured by Sigma-Aldrich) was dissolved in chloroform and cooled in an ice-water bath. To this solution, 95 parts by weight of chlorosulfonic acid relative to the PPE was added dropwise over 10 minutes, the ice-water bath was removed, the temperature was raised to room temperature, and stirring was continued for 1 hour. The resulting precipitate was collected by filtration and washed in chloroform by stirring for 10 minutes. After repeating washing with chloroform three times, the precipitate was washed with water in the same manner except that the solvent was ion-exchanged water. After repeated water washing until the pH of the washing solution reached 5 or higher, the precipitate was removed and dried at 50°C for 24 hours to obtain a sulfonated polyphenylene ether resin.

[0047] 100 parts by mass of the perfluorocarbon sulfonic acid resin obtained by the above method and 20 parts by mass of sulfonated polyphenylene ether resin were mixed, and then dissolved in NMP so that the concentration of the mixed resin was 10% by mass to obtain a solution. The obtained solution was applied in the form of a film on a glass plate as a support, dried at 170°C for 1 hour in a hot air oven, and peeled off from the glass plate to obtain a 25 μm thick film composed of perfluorocarbon sulfonic acid resin and sulfonated polyphenylene ether. The Young's modulus of the film was 3.0 GPa, and the hydrogen gas permeability coefficient was 1.5 × 10 －９ cm ３ cm / (s cm ２ ・cmHg).

[0048]

Claims

1. A polymer containing a wholly aromatic polyamide, a wholly aromatic polyamideimide, and / or a wholly aromatic polyimide, in which the number of repeating units of the wholly aromatic polyamide, the wholly aromatic polyamideimide, and / or the wholly aromatic polyimide is 80% or more of the total number of repeating units in the polymer, and the pK ａ a protonic acidic group A (functional group A) and / or a group of its conjugate base, both of which have a molecular weight of -3.0 or more and 2.0 or less, is contained in a repeating unit of a wholly aromatic polyamide, a wholly aromatic polyamideimide and / or a wholly aromatic polyimide, ｉｎｈ The polymer has a viscosity of 1.25 dL / g or more and 8.00 dL / g or less.

2. The polymer according to claim 1, wherein the number of repeating units containing functional group A and / or its conjugate base group in the polymer is 10% or more and 100% or less of the number of repeating units of wholly aromatic polyamide, wholly aromatic polyamideimide and / or wholly aromatic polyimide in the polymer.

3. The polymer according to claim 2, wherein the functional group A is a sulfonic acid group and / or a phosphonic acid group.

4. A film comprising the polymer of claim 1 as a main component.

5. The film of claim 4, which has a Young's modulus of 5.0 GPa or more and 15.0 GPa or less when the film has a thickness of 25 μm.

6. Hydrogen gas permeability coefficient at 25°C and 10% relative humidity is 1.0 x 10 －１１ cm ３ cm / (s cm ２ ・cmHg) or more than 2.0 x 10 －９ cm ３ cm / (s cm ２ 5. The film of claim 4, wherein the viscosity is less than or equal to 1.0 cmHg.

7. The film of claim 4, which, when made to have a thickness of 25 μm, increases in membrane weight by 5% by weight or more and 150% by weight or less when immersed in water at room temperature for 20 minutes.

8. A method for producing the polymer according to claim 1, comprising adding a Bronsted base to a monomer containing the functional group A and / or a group of its conjugate base, followed by polycondensation to obtain a polymer, the method comprising the steps of: (a) preparing a polymer from a monomer containing an aromatic diamine and an aromatic dicarboxylic acid dichloride; 9. An ion-conducting membrane comprising the polymer of claim 1.

10. A solid electrolyte membrane comprising the polymer of claim 1.

11. An ion exchange membrane comprising the polymer of claim 1.

12. A membrane for a redox flow device comprising the polymer of claim 1.

13. A secondary battery comprising the ion conductive membrane according to claim 8.

14. A water electrolysis device comprising the solid electrolyte membrane according to claim 9.

15. A fuel cell comprising the solid electrolyte membrane according to claim 9.