Method for improving anion conductivity in anion exchange resin, composite anion exchange resin, water electrolysis device, and method for producing composite anion exchange resin membrane

Abstract

The present invention is characterized in that an anion exchange resin having a plurality of ion exchange groups is combined with an electron deficient pi-conjugated molecular compound exhibiting anion-pi interaction to thereby promote dissociation and transport of anions of the anion exchange resin due to the anion-pi interaction. In the present invention, it is desirable to improve anion conductivity while achieving stabilization of the anions on the surface of the anion exchange resin by an electrostatic relaxation effect due to the anion-pi interaction exhibited by the molecular compound in the presence of electrostatic interaction exhibited by the anion exchange resin.

Description

Method for improving anion conductivity in anion exchange resin, composite anion exchange resin, water electrolysis device, and method for manufacturing a composite anion exchange resin membrane.

[0001] The present invention relates to a method for improving the anion conductivity of an anion exchange resin, a composite anion exchange resin, a water electrolysis device, and a method for manufacturing a composite anion exchange resin membrane. This application claims priority based on Japanese Patent Application No. 2025-025903, filed in Japan on February 20, 2025, the contents of which are incorporated herein by reference.

[0002] Water electrolysis using anion exchange membranes made of anion exchange resin has recently attracted attention as a technology that can produce hydrogen efficiently and inexpensively. By using anion exchange membranes, water electrolysis can be performed without the need for precious metal catalysts used in conventional cation exchange membrane type water electrolysis, and it has the advantage of higher efficiency because the distance between electrodes is shorter than in conventional alkaline water electrolysis using high-concentration alkaline aqueous solutions. Furthermore, in water electrolysis using anion exchange membranes, dry cathode operation, in which electrolyte is not supplied to the hydrogen generation electrode (cathode), eliminates or simplifies the process of removing water from the produced hydrogen, and is expected to reduce the cost of hydrogen production.

[0003] Non-Patent Document 1 below introduces the development of various anion exchange resins. The technologies described in Non-Patent Document 1 can all be said to be technologies that focus on the chemical structure of the polymer back chain or anion exchange group. Non-Patent Document 2 below is a document relating to a technology previously published by the present inventors, and discloses the matrix material for anion exchange resins. Furthermore, Non-Patent Document 3 reports electron-deficient pi-conjugated molecules that interact with various anions, but the technology described in Non-Patent Document 3 is intended for the academic understanding of the interaction and its application to anion sensing technology.

[0004] EJ Park et al., "Aryl ether-free polymer electrolytes for electrochemical and energy devices", Chem. Soc. Rev., 2024, 53, 5704-5780.Y. Nara, M. Tanaka, et al., "Development of highly alkaline stable anion conductive polymers with fluorene backbone for water electrolysis ", Polym. Adv. Technol., 2022, 33, 2863.M. Savastano et al., "Halide and hydroxide anion binding in water", Dalton Trans., 2018, 47, 3329.

[0005] Non-Patent Document 1 describes the development of various anion exchange resins, but all of them focus on the chemical structure of the polymer backbone or anion exchange group, and no examples of anion exchange resin development focusing on non-covalent interactions are shown. Non-Patent Document 2 concerns a technology that utilizes the matrix material of anion exchange resin as a single material, but does not disclose other technologies. The technology described in Non-Patent Document 3 is an application technology for anion sensing technology, etc., and does not disclose any technologies related to anion exchange resins or water electrolysis.

[0006] As mentioned above, water electrolysis using anion exchange membranes has attracted attention as a hydrogen production technology, but in conventional technology, electrolyte solution must be supplied to both the cathode and anode sides. If a structure is adopted in conventional technology that does not supply electrolyte solution to the cathode side, both the anion exchange membrane and the anion exchange ionomer used in the cathode will be in a low-water-content environment, resulting in a significant decrease in anion conductivity and chemical stability.

[0007] As a result of diligent research, the inventors focused on electron-deficient pi-conjugated molecules that interact with anions and discovered that by mixing these molecules with anion exchange resin, unprecedentedly superior ionic conductivity is achieved in low-water or non-water environments. The present invention aims to provide a technology that enables the achievement of excellent anionic conductivity and chemical stability even in low-water conditions by promoting the dissociation and diffusion of anions, which are conductive ion species, through the expression of anion-pi interactions within the anion exchange resin, and by reducing alkali attack due to the presence of bulky molecules near the anion exchange group. Furthermore, the present invention aims to provide a water electrolysis apparatus equipped with a composite anion exchange resin membrane utilizing this technology and a method for manufacturing the composite anion exchange resin membrane.

[0008] The present invention provides a method for improving the anion conductivity of an anion exchange resin, characterized by combining an anion exchange resin having multiple ion exchange groups with an electron-deficient pi-conjugated molecule compound that exhibits anion-pi interactions, thereby promoting the dissociation and movement of anions in the anion exchange resin through anion-pi interactions.

[0009] According to the present invention, by utilizing an electron-deficient pi-conjugated molecule compound that exhibits anion-pi interaction with multiple anion exchange groups in an anion exchange resin, anions can be moved along the anion exchange groups by hopping, thereby obtaining good anion conductivity. Furthermore, anion conduction using an electron-deficient pi-conjugated molecule compound that exhibits anion-pi interaction with anion exchange groups exhibits good ionic conductivity even when water is not present around the conducting anions. In addition, in the case of anion conduction in the case of anion conduction in the case of water not present, the conventional anion conduction mechanism by hydration may cause the anions to attack and decompose the anion exchange groups or polymer backbone formed in the anion exchange resin, resulting in a lack of chemical stability in environments without water or with low water content. In contrast, the anion conduction mechanism using an electron-deficient pi-conjugated molecule compound that exhibits anion-pi interaction according to the present invention can mitigate the electrostatic interaction between the anion exchange groups and anions. Electron-deficient pi-conjugated molecular compounds that exhibit anion-pi interactions reduce the nucleophilicity of anions and suppress the decomposition reactions of anion exchange groups and polymer backbone structures. Therefore, they can provide a stable anion conduction mechanism with good ionic conductivity.

[0010] A schematic cross-sectional view of a water electrolysis apparatus according to the first embodiment of the present invention. A schematic cross-sectional view showing an example of a conventional water electrolysis apparatus. An explanatory diagram showing an example of the reaction mode on the anode and cathode sides of a water electrolysis apparatus according to the first embodiment. An explanatory diagram showing an example of the reaction mode on the anode and cathode sides of a conventional water electrolysis apparatus. An explanatory diagram showing the direction of electroosmotic water and concentrated water diffusion in a water electrolysis apparatus according to the first embodiment. An explanatory diagram showing a model state of anion conduction in relation to an anion exchange group used in the anion conduction mechanism according to the present invention and a molecular compound exhibiting anion-pi interaction. An explanatory diagram showing the relationship between an anion exchange group and a molecular compound exhibiting anion-pi interaction in the anion conduction mechanism according to the present invention. An explanatory diagram showing a model state of anion conduction in relation to an anion exchange group and anion used in a conventional hydration-based anion conduction mechanism. An explanatory diagram showing the relationship between an anion exchange group, a molecular compound exhibiting anion-pi interaction, and anion in the anion conduction mechanism according to the present invention. An explanatory diagram showing a typical structure of a polymer material having an anion exchange group. An explanatory diagram showing a typical structure of a polymer material having an anion exchange group. Figures 10 and 11 show examples of compounds used as main chain 1 for the structure shown in Figures 10 and 11. Figures 10 and 11 show examples of compounds used as main chain 1 for the structure shown in Figures 10 and 11. Figures 10 and 11 show examples of compounds used as main chain 2 for the structure shown in Figures 10 and 11. Figures 10 and 11 show examples of compounds used as spacers for the structure shown in Figures 10 and 11. Figures 10 and 11 show examples of compounds used as anion exchange groups for the structure shown in Figures 10 and 11. Figures 10 and 11 show examples of compounds used as anion interacting molecules for the structure shown in Figures 10 and 11. Figures 10 and 11 show examples of compounds used as anion interacting molecules for the structure shown in Figures 10 and 11. (a) is a photograph of the film obtained in Example 1, (b) is a photograph of the film obtained in Comparative Example 2a, (c) is a photograph of the film obtained in Comparative Example 2b, and (d) is a photograph of the film obtained in Comparative Example 2c. (a) is a photograph of the film obtained in Comparative Example 2d, (b) is a photograph of the film obtained in Comparative Example 2e, (c) is a photograph of the film obtained in Comparative Example 2f, (d) is a photograph of the film obtained in Comparative Example 4, (e) is a photograph of the film obtained in Example 5, and (f) is a photograph of the film obtained in Example 8.An explanatory diagram showing the method for measuring the anion conductivity of the anion exchange membranes of the examples and comparative examples. A graph showing the simulation results of density functional theory (DFT) regarding the effect of dissociating anions (Cl-) with and without molecular compounds exhibiting anion-pi interactions. A graph showing the simulation results of the stabilization energy according to the distance between the anion exchange group and the Cl- ion, in relation to molecular compounds exhibiting anion-pi interactions and ion exchange groups. A graph showing the simulation results of density functional theory (DFT) regarding the effect of dissociating anions (Br-) with and without molecular compounds exhibiting anion-pi interactions. A graph showing the simulation results of the stabilization energy according to the distance between the anion exchange group and the Br- ion, in relation to molecular compounds exhibiting anion-pi interactions and ion exchange groups. A graph showing the simulation results of density functional theory (DFT) regarding the effect of dissociating anions (I-) with and without molecular compounds exhibiting anion-pi interactions. A graph showing the simulation results using density functional theory (DFT) regarding the relationship between the anion dissociation effect and stabilization energy for three molecules exhibiting anion-pi interaction. A graph showing the water electrolysis evaluation results using the anion exchange resin (TMA-PF w / Tz2_4 / 1) compounded with the anion-pi interaction molecules prepared in Example 10, and the anion exchange resin alone (TMA-PF) prepared in Comparative Example 6. A graph showing the water electrolysis evaluation results with the same configuration as in Figure 30, but with IR resistance removed. A graph showing the IR resistance results for the water electrolysis evaluation results with the same configuration as in Figure 30. Part of the alkali stability test results are shown. １ 1H NMR spectrum. Diagram showing the structural formula of the estimated compound after the alkaline stability test. Diagram showing the dry alkaline stability test being conducted in an anhydrous environment. Each sample obtained after the dry alkaline stability test. １ 1H NMR spectrum. Figure showing Hoffmann elimination presumed to occur during dry alkali stability testing. １ 1H NMR spectrum. The results obtained for each sample in the dry alkali stability test. １A magnified section of the 1H NMR spectrum. A graph showing the first example of dry cathode water electrolysis test results. A graph showing the second example of dry cathode water electrolysis test results. Results of dry alkali stability tests for various samples in an anhydrous environment. １ ¹H NMR spectrum. Figure showing Hoffmann desorption presumed to occur during dry alkali stability testing in an anhydrous environment. Graph showing the temperature dependence of anion conductivity after dry alkali stability testing in a high humidity environment. Graph showing the results of anion conductivity measurement in a composite film with Tz2. Figure showing the chemical structure of Dim(Br)-PF. Graph showing simulation results of stabilization energy depending on the distance between the anion exchange group and the Cl- ion, relating to molecular compounds exhibiting anion-pi interaction and ion exchange groups. Graph showing the simulation results of density functional theory (DFT) for the effect of anion (Cl-) separation due to the presence or absence of molecular compounds exhibiting anion-pi interaction (relationship between cation-anion distance and λ). Graph showing the simulation results of density functional theory (DFT) for the effect of anion (Cl-) separation due to the presence or absence of molecular compounds exhibiting anion-pi interaction (relationship between the difference in cation-anion distance and λ).

[0011] Hereinafter, with reference to the drawings, a water electrolysis apparatus and an anion exchange resin used in the water electrolysis apparatus according to the first embodiment of the present invention will be described. The embodiments described below are provided specifically to better illustrate the spirit of the invention and do not limit the present invention unless otherwise specified. Furthermore, the drawings used in the following description may be enlarged for convenience to clearly illustrate the features of the present invention.

[0012] Figure 1 shows an example of a water electrolysis apparatus A according to the first embodiment. An anion exchange membrane 3 is positioned between a planar gas-diffusive positive electrode 1 and a negative electrode 2 that are facing each other. A positive electrode side catalyst layer 5 is provided on the positive electrode side of the anion exchange membrane 3, and a negative electrode side catalyst layer 6 is provided on the negative electrode side of the anion exchange membrane 3. A positive electrode side separator 7 is positioned outside the positive electrode 1 to form a flow path for the electrolyte, and a negative electrode side separator 8 is positioned outside the negative electrode 2. The positive electrode side separator 7 and the negative electrode side separator 8 are provided so as to sandwich the laminate of the positive electrode side catalyst layer 5, the positive electrode 1, the anion exchange membrane 3, the negative electrode 2, and the negative electrode side catalyst layer 6 from both sides in the direction of their stacking. The positive electrode 1 corresponds to a gas-permeable anode electrode, and the negative electrode 2 corresponds to a gas-permeable cathode electrode. The positive electrode side separator 7 is electrically connected to the positive electrode side of the power supply 9, and the negative electrode side separator 8 is electrically connected to the negative electrode side of the power supply 9. This configuration allows power to be supplied from the power supply 9 to the positive electrode separator 7 and the negative electrode separator 8, electrolyzing the electrolyte supplied between them and generating hydrogen gas on the negative electrode side.

[0013] When the outer periphery of the positive electrode separator 7 and the negative electrode separator 8 in Figure 1 are enclosed with a case not shown, a flow path is formed between the positive electrode separator 7 and the anion exchange membrane 3. Part of this flow path is connected to the electrolyzed water supply tank 10 via a water supply pipe as an inlet 7a. The other part of the flow path is connected to the electrolyzed water recovery tank 11 via a water distribution pipe as an outlet 7b. Furthermore, when enclosed with a case not shown, a passage is also formed between the negative electrode separator 8 and the anion exchange membrane 3, and a hydrogen gas outlet 8a is formed in part of this passage.

[0014] The positive electrode 1 is, for example, made of a gas-diffusible metal mesh. The metal mesh can be made of metal fibers such as Ti. For example, the thickness of the metal mesh is about 300 μm. The negative electrode 2 is, for example, made of gas-diffusible conductive carbon paper. For example, the thickness of the negative electrode 2 can be about 300 μm. The positive electrode side catalyst layer 5 is, for example, made of iridium oxide particles (IrO ２It can be composed of a metal mesh supporting anode-side catalyst particles such as (particle). The negative electrode-side catalyst layer 6 can be composed of, for example, a carbon layer supporting cathode-side catalyst particles such as platinum nanoparticles (Pt particles).

[0015] The water electrolysis device A with the configuration shown in FIG. 1 has a configuration similar to a water electrolysis device generally referred to as an anion exchange membrane (AEM: Anion Exchange Membrane)type water electrolysis device. However, while a general anion exchange membrane type water electrolysis device has water inlet and outlet parts on both the negative electrode side and the positive electrode side, in the water electrolysis device A of FIG. 1, the water inlet part on the negative electrode side can be omitted. Moreover, the point that dry H ２ gas is discharged from the outlet part 8a of the water electrolysis device A is different from a general anion exchange membrane type water electrolysis device. As shown in the structure of FIG. 2 described later, it may be configured so that the electrolysis characteristics can be evaluated as a configuration capable of supplying water. In the water electrolysis device A, the electrolytic solution that has passed through the anion exchange membrane 3 is immediately reduced on the negative electrode body 2 side, and H ２ gas is discharged from the outlet part 8a on the negative electrode side separator 8 side, and OH － generated as an anion passes through the anion exchange membrane 3 and heads toward the positive electrode side separator 7 side. The above state is shown in FIG. 1 by an arrow labeled H ２ [[ID=ll]]O and an arrow labeled OH － .

[0016] The water electrolysis device applied to the present invention is such that the electrolytic solution on the positive electrode side (anode side)moves to the negative electrode side [[ID=l6]](cathode side), H ２ gas is generated on the negative electrode side, and the purpose can be achieved if OH － moves from the negative electrode side to the positive electrode side. Therefore, various configurations can be adopted for the configuration of the water electrolysis device.

[0017] Figure 2 shows a conventional water electrolysis apparatus B. In this water electrolysis apparatus B, a positive electrode catalyst layer 5 is arranged on one side of the thickness direction of the anion exchange membrane 3, and a negative electrode catalyst layer 6 is arranged on the other side. A porous metal transport layer 12 and a positive electrode separator 13 are arranged outside the positive electrode catalyst layer 5 to form a flow path for the electrolyte, and a porous transport layer 15 made of porous carbon paper or the like and a negative electrode separator 16 are arranged outside the negative electrode catalyst layer 6. The porous metal transport layer 12 can be made of nickel foam or the like, and the porous transport layer 15 can be made of carbon paper or the like. The general outline of the water electrolysis apparatus B is constructed by surrounding the entire laminate, which includes the positive electrode separator 13, the porous metal transport layer 12, the positive electrode catalyst layer 5, the anion exchange membrane 3, the negative electrode catalyst layer 6, the porous transport layer 15, and the negative electrode separator 16 shown in Figure 2, with a case or the like (not shown).

[0018] When enclosed in a case (not shown), the porous metal transport layer 12 becomes a channel for the electrolyte. By forming an inlet in a part of the case that leads to the porous metal transport layer 12, an electrolyte inlet 17 can be formed, and by forming an outlet in another part of the case that leads to the porous metal transport layer 12, an oxygen or electrolyte outlet 18 can be formed. When enclosed in a case (not shown), the porous transport layer 15 becomes the electrolyte containment section. By forming an inlet in a part of the case that leads to the porous transport layer 15, an electrolyte inlet 19 can be formed, and by forming an outlet in another part of the case that leads to the porous transport layer 15, a hydrogen gas outlet 20 can be formed. By configuring the system to allow electrolyte supply to the negative electrode side as shown in Figure 2, it becomes possible to evaluate the electrolytic properties described later.

[0019] In water electrolysis apparatus A, OH moves in the direction of the film thickness of the anion exchange membrane 3. － Figures 3 and 5 show the direction of ion and electrolyzed water movement, the direction of electron movement supplied from power supply 9, and an overview of the substances generated on the positive and negative electrode sides. Figure 3 shows the schematic configuration of water electrolysis apparatus A, including the arrangement and connection relationships of the anion exchange membrane 3, positive electrode 1, negative electrode 2, and power supply 9, as well as an overview of the direction of charge movement and the substances generated on the positive and negative electrode sides. In contrast, Figure 4 shows an overview of a conventional water electrolysis apparatus B. In conventional water electrolysis apparatus B, OH moves in the direction of the film thickness of the anion exchange membrane 3. －Figure 4 shows an overview of the direction of ion movement, the direction of charge movement supplied from the power supply 9, and the substances generated on the positive and negative electrode sides. In the conventional water electrolysis apparatus B, a positive electrode structure 22 is provided on one side in the thickness direction of the anion exchange membrane 21, comprising a positive electrode separator 13, a metal porous transport layer 12, and a positive electrode catalyst layer 5, while a negative electrode structure 23 is provided on the other side in the thickness direction of the anion exchange membrane 21, comprising a negative electrode separator 16, a metal porous transport layer 15, and a negative electrode catalyst layer 6.

[0020] In the water electrolysis apparatus A of this embodiment, H permeates through the anion exchange membrane 3. ２ O is immediately electrolyzed, and H is produced on the negative electrode side. ２ Only the generated OH － The ions pass through the anion exchange membrane 3, and H is present on the positive electrode side. ２ O and O ２ The following reaction is generated. The reaction on the positive electrode side (anode side) and the reaction on the negative electrode side (cathode side) are shown in the following equations. Anode side reaction: 2OH － →2e － +H ２ O + (1 / 2) O ２ Cathode reaction: 2H ２ O + 2e － →H ２ +2OH －

[0021] In contrast, in the conventional water electrolysis apparatus B, water (H) is also present on the negative electrode side (cathode side). ２ O) needs to be supplied. In this device, H is on the negative side. ２ O is generated, and water is also present on the negative electrode side. Also, electrolyzed water is supplied on the positive electrode side (anode side), ２ It generates.

[0022] As is clear from comparing Figures 3 and 4, in the water electrolysis apparatus A according to this embodiment, water is not required on the negative electrode side, and H is used on the negative electrode side. ２ Only gas is produced. This indicates that water electrolysis device A can operate in a dry cathode configuration, which does not require water on the negative electrode side (cathode side). Conversely, this means that water is essential for conventional water electrolysis device B.

[0023] In order to realize a water electrolysis device A and obtain good water electrolysis capacity, anions (OH) in an anion exchange membrane 3 under an anhydrous environment － ) requires good conductivity. Therefore, in the water electrolysis apparatus A of this embodiment, an anion exchange membrane 3 is used, which is made of a mixed resin in which an electron-deficient π-conjugated molecule compound is added to an anion exchange resin having multiple anion exchange groups. This anion exchange membrane 3 exhibits good anionic conductivity even in low water content or low humidity environments.

[0024] Figure 6 shows a state in which a molecular compound 27 exhibiting anion-pi interaction (anion π interaction) coexists on the surface of an anion exchange resin 26 having multiple ion exchange groups 25, and one type of anion is OH － An example of a model in which conduction occurs is shown. An example of a model molecule of the anion exchange resin 26 having anion exchange groups can be represented by the following equation (1).

[0025]

[0026] As a more specific example of a polymer that can be applied to the anion exchange resin 26, tetramethylammonium polyfluorene (TMA-PF) shown in the following formula (2) can be used.

[0027]

[0028] The model of anion exchange resin having multiple anion exchange groups, as mentioned above, and the molecular model shown in equation (2) below as an electron-deficient pi-conjugated molecule compound exhibiting anion-pi interaction are explained below. Pi-conjugated molecules shown in equation (2) below, such as benzene rings substituted with electron-withdrawing fluorine, are known to become slightly positively charged overall due to electron deficiency (deficiency), and to form non-covalent interactions with anions.

[0029]

[0030] The inventors conceived the idea that by utilizing an electron-deficient pi-conjugated molecular compound exhibiting anion-pi interactions and an anion exchange resin having the aforementioned anion exchange group, it might be possible to mitigate the electrostatic interactions when anions move while hopping between multiple anion exchange groups, thereby promoting their movement. Based on this idea, various studies were conducted. As a result, it was discovered that a novel anion conduction mechanism previously unknown emerges by using the tetrazine derivative shown in equation (4) below.

[0031]

[0032] Furthermore, a more specific tetrazine derivative can be selected from the tetrazine derivatives shown in formula (5) below. This tetrazine derivative is 3,6-Bis(morpholin-4-ylethyl)-1,2,4,5-tetrazine. In this specification, this tetrazine derivative may be abbreviated as Tz2 below.

[0033]

[0034] When a molecular compound of a tetrazine derivative shown in formula (4) or formula (5) is present near the anion exchange group of an anion exchange resin, an OH group is present nearby. － When ions are present, the low-water-content OH shown in Figure 6 － The conduction mechanism is obtained, and this low-water-content OH － The conduction mechanism is thought to be a result of the interaction shown in Figure 7. As shown in Figure 7, in low-water or anhydrous environments, OH － The ion and the nitrogen atom located outside the tetrazine skeleton form a hydrogen bond, and the tetrazine derivative undergoes an OH interaction. － It relaxes the negative charge of the ions, and OH － The goal is to stabilize ions, dissociate ion exchange groups, and improve anionic conductivity. These effects related to improving anionic conductivity are thought to be achievable by synthesizing a polymer compound having a tetrazine skeleton in its main chain or side chains, and then compounding (compounding) it with an anionic conductive polymer to form a composite anion exchange resin film.

[0035] Low-water content OH as illustrated in Figure 7 － Regarding the conduction mechanism, conventionally known general OH － The conduction mechanism is as shown in Figure 8, involving the hydrated state of OH － This is known as a mechanism that allows ions to move along anion exchange groups. － Water is required for ions to hydrate. － In the conduction mechanism, OH in hydrated state － Ions are required, and in low-water or anhydrous environments, anions have difficulty dissociating from anion exchange groups due to electrostatic interactions. In anhydrous environments, anionic conductivity may decrease to less than 1 / 1000th compared to conditions in water. Also, unhydrated OH in low-water environments － The ions become highly nucleophilic, which poses a problem as they decompose the ion exchange groups and polymer backbone of anion exchange resins. Therefore, conventional OH － The conduction mechanism suffers from poor alkaline stability. Therefore, it is desirable that the anion exchange membrane itself exhibits high conductivity and high stability, even in low-water or anhydrous states.

[0036] In the anion exchange membrane 3 applied to water electrolyzers A and B, even in a low water content or anhydrous state, as shown in Figure 9, OH － This suppresses the decrease in nucleophilicity of ions and the decomposition reaction of ion exchange groups. As a result, even in an anhydrous state, the decomposition reaction of ion exchange groups can be suppressed, thus preventing damage to the anion exchange resin. In other words, stable anionic conductivity can be obtained.

[0037] By synthesizing the molecular compound having the aforementioned tetrazine skeleton and compounding it with an anion-conducting polymer (polycation), an anion-conducting resin that exhibits the desired effect can be obtained, and by obtaining a film made of this resin, the aforementioned anion exchange membrane 3 can be obtained. For example, a solution of the anion exchange resin (anion-conducting polymer) can be prepared, a tetrazine derivative can be added to this solution, and an anion exchange membrane can be fabricated by solvent casting. In the obtained anion exchange membrane, the tetrazine derivative is a counteranion (OH) of the ion exchange group. － , Cl － , Br －, I － It interacts broadly with (etc.). When forming films by solvent casting, a method can be applied in which the solution on a hot plate is dried in the air at a temperature of about 60-80°C.

[0038] The formation of anion-pi interactions and anion conductivity characteristics can be evaluated by electrochemical impedance measurements and the calculation of diffusion coefficients using quantum chemical calculations. Therefore, tests are conducted using these methods in the examples described later. These tests reveal the OH reaction due to anion-pi interactions. － This allows us to verify the reduction in nucleophilicity and the suppression of the decomposition reaction of ion exchange groups. Furthermore, it can be presumed that electrostatic relaxation due to anion-pi interactions also plays a role. These tests have revealed that anion-pi interactions are effective in improving anion conductivity and alkaline stability in low-water or anhydrous environments.

[0039] Furthermore, no studies have been reported worldwide to date that have achieved improved and stable anion conductivity under low-moisture or anhydrous conditions. Therefore, the proposed anion conduction mechanism based on the results of this invention is of great academic significance. Moreover, the provision of an anion exchange membrane type water electrolysis device utilizing an anion conduction mechanism under low-moisture or anhydrous conditions is expected to be applicable not only to dry cathode type water electrolysis technology, but also to the application of anion exchange membranes to metal-air secondary batteries where humidification is difficult, and to the practical application and cost reduction of anion exchange membrane type fuel cells, which have challenges in high-temperature and low-humidity operation.

[0040] Furthermore, the tetrazine derivatives shown in equations (4) and (5) above are OH － , Cl － , Br － , I － SO ４ ２－ , PF ６ － NO ３ － F － Among these anions, one or more are thought to contribute to anion conduction as counterion species.

[0041] By the way, in the examples mentioned above, several examples were shown of polymer materials constituting the anion exchange membrane that serves as the base material, and electron-deficient pi-conjugated molecular compounds exhibiting anion-pi interactions that should be blended. However, the present invention is not limited to these exemplified materials. Any combination of polymer materials having multiple anion exchange groups and molecular compounds exhibiting anion-pi interactions can be realized. For example, various structures shown in Figures 10 and 11 can be applied as polymer materials having multiple anion exchange groups. The basic structure consists of a polymer backbone and anion exchange groups, with a backbone 1 to which anion exchange groups are bound, a backbone 2 without anion exchange groups, and a spacer molecule interposed between the anion exchange groups and backbone 1.

[0042] Examples of main chain 1 include polyethylene skeletons obtained by polymerization of vinyl monomers, polyethylene oxide skeletons containing ether oxygen, polyphenylene oxide skeletons in which phenyl rings and ethers are alternately bonded, polyarylene ether ketones, polyarylene ether sulfones, and polyimide skeletons, which are known as engineering plastics, as well as polyphenylene skeletons in which the main chain consists entirely of aromatic carbon atoms, polyarylene methylene skeletons composed of aromatic hydrocarbons and aliphatic hydrocarbons, and polyfluorene skeletons having a five-membered ring formed by the fusion of two six-membered rings. Examples of polymer skeletons applicable as main chain 1 are shown in Figures 12 (A) to (Z) and Figures 13 (A) to (W). Similar polymer skeletons can also be used for main chain 2, differing from main chain 1 in that they do not have bonding sites for anion exchange groups. These main chains 1 and 2 can take various bonding modes, such as alternating copolymers, block copolymers, and random copolymers, and the ratio of main chain 1 to main chain 2 can be freely set considering solubility, stability, ionic conductivity, etc. Examples of polymer skeletons applicable as main chain 2 include those shown in Figures 14(A) to (Z) and Figures 15(A) to (O).

[0043] Spacer molecules are important for enhancing the mobility of anion exchange groups and improving their chemical durability. Various types of anion exchange groups can be applied, including alkyl-substituted quaternary ammonium, cyclic quaternary ammonium, ammonium with two linked rings, three-dimensional cyclic ammonium, aromatic quaternary amines such as piperidium and imidazolium, quaternary nitrogen with an N-C=N structure, sulfonium other than nitrogen cations, phosphonium, and phosphazenium. Examples of polymer skeletons that can be applied as spacers are shown in Figures 16 (A) to (E).

[0044] Examples of polymer compounds that can be used as anion exchange groups include those shown in Figures 17(A) to (O) and Figures 18(A) to (O).

[0045] For example, examples of electron-deficient pi-conjugated molecular compounds that exhibit anion-pi interactions include polyfluorinated benzenes, naphthalenes, biphenyls, quinoid molecules with halogens or cyano groups attached, electron-withdrawing trifluoromethane or nitro groups, benzenes with multiple cyano groups substituted, naphthalenediimides and perylenediimides with high planarity, planar fused ring molecules with alternating nitrogen and carbon bonds, and cyclic molecules containing boron or phosphorus. Applicable polymer compounds as electron-deficient pi-conjugated molecular compounds that exhibit anion-pi interactions include examples shown in Figures 19 (A) to (T) and Figures 20 (A) to (N).

[0046] The following describes examples in detail and further explains the anion exchange membrane and water electrolysis apparatus according to the present invention. It should be noted that the anion exchange membrane and water electrolysis apparatus according to the present invention are not limited to the descriptions in the following examples.

[0047] (Synthesis Example 1) [Synthesis of Precursor Polyfluorene (Br-PF)] In accordance with a report previously published by the present inventors (Y. Nara, et al., Polymers for Advanced Technology, 33, 2863-2871 (2022)), under a nitrogen atmosphere, a three-necked flask was prepared with tetrahydrofuran (68 mL, manufactured by Kanto Chemical Co., Ltd.), 2,7-dibromo-9,9-bis(6-bromohexyl)fluorene 2.275 g (3.5 mmol, manufactured by Tokyo Chemical Co., Ltd.), 9,9-dioctylfluorene-2,7-diboronic acid bis(1,3-propanediol) ester 1.954 g (3.5 mmol, manufactured by Sigma-Aldrich), bistriphenylphosphine palladium dichloride 61.4 mg (0.0875 mmol, manufactured by Sigma-Aldrich), and potassium carbonate aqueous solution 34 mL (2 A mol / L solution (prepared from Kanto Chemical Co., Ltd.) was added and stirred at 70°C for 7 hours to synthesize precursor polyfluorene (Br-PF). The synthesized Br-PF was precipitated using a hydrochloric acid-ethanol mixed solvent, and then recovered by washing with hot water. Furthermore, the recovered Br-PF was vacuum dried at 60°C for 12 hours to completely remove the solvent.

[0048] Next, the 1H NMR spectrum of Br-PF was measured using a Bruker-500 FT / NMR spectrometer (manufactured by Bruker). The proton ratios of the aromatic main chain skeleton and the alkyl side chains confirmed that the target substance was obtained without side reactions.

[0049] Next, using a gel permeation chromatograph (JASCO HPLC pump PU-2080PLUS, JASCO detector UV-2075, and Resonaq SHODEX KF-805L column), the molecular weight of Br-PF was measured using THF (tetrahydrofuran) as the solvent. The molecular weight, calculated on a polystyrene basis, was found to be 2.6 × 10⁻⁶. ５ The polydispersity Mw / Mn was 6.2.

[0050] (Synthesis Example 2) [Synthesis of tetramethylammonium polyfluorene (TMA(Br)-PF) having bromide ions as counterion species] The Br-PF synthesized in (Synthesis Example 1) was dissolved in chloroform at a concentration of about 3% by mass to prepare an anion exchange resin solution, which was poured onto a petri dish and left to stand at room temperature overnight or longer to evaporate the solvent and form a film. Subsequently, the Br-PF film peeled off the petri dish was immersed in a 30% trimethylamine solution (manufactured by Tokyo Chemical Industry Co., Ltd.) and subjected to a quaternary ammonia reaction at room temperature for 72 hours to synthesize tetramethylammonium polyfluorene (TMA(Br)-PF). The obtained TMA(Br)-PF film was washed several times with distilled water and then immersed in distilled water for 24 hours to remove residual solvent and impurities. After that, it was vacuum dried at 60°C for 12 hours.

[0051] Next, the 1H NMR spectrum of TMA-PF was measured using a Bruker-500 FT / NMR spectrometer (manufactured by Bruker). Tetramethylammonium group CH4 was detected at 2.95 ppm and 1.49 ppm. ２ and CH ３ A peak originating from this was observed, indicating that the quaternary ammoniation reaction proceeded. The peak integral ratio around 8.0 ppm, which is unaffected by the quaternary ammoniation reaction, and the CH groups of 2.95 ppm and 1.49 ppm of the tetramethylammonium group were observed. ２ and CH ３ From the integral ratio of the peaks derived from this, it became clear that two quaternary ammonia groups are introduced per repeating unit.

[0052] (Synthesis Example 3) [Synthesis of tetramethylammonium polyfluorene (TMA(OH)-PF) having hydroxide ions as counterion species] The TMA(Br)-PF membrane obtained in Synthesis Example 2 was immersed in a 1 M sodium hydroxide aqueous solution (prepared from Kanto Chemical Co., Ltd.) at room temperature for 12 hours to exchange the counterion species, and tetramethylammonium polyfluorene (TMA(OH)-PF) having hydroxide ions as counterions was obtained.

[0053] (Synthesis Example 4) [Synthesis of tetramethylammonium polyfluorene (TMA(Cl)-PF) having chloride ions as counterion species] The TMA(OH)-PF membrane obtained in Synthesis Example 3 was immersed in a 1 M aqueous solution of sodium chloride (prepared from Kanto Chemical Co., Ltd.) at room temperature for 12 hours to exchange the counterion species, thereby obtaining tetramethylammonium polyfluorene (TMA(Cl)-PF) having chloride ions as counterions.

[0054] (Synthesis Example 5) [Synthesis of tetramethylammonium polyfluorene (TMA(I)-PF) having iodide ions as counterion species] The TMA(Br)-PF) membrane obtained in Synthesis Example 2 was immersed in a 1 M aqueous solution of potassium iodide (prepared from Kanto Chemical Co., Ltd.) at room temperature for 12 hours to exchange the counterion species, thereby obtaining tetramethylammonium polyfluorene (TMA(I)-PF) having iodide ions as counterions.

[0055] (Synthesis Example 6) [Synthesis of 3,6-Bis(morpholin-4-ylmethyl)-1,2,4,5-tetrazine (Tz1)] Following the previously reported method (M. Melguizo et al., Dalton Trans., 2018, 47, 3329.), under a nitrogen atmosphere, using methanol (10 mL, Kanto Chemical Co., Ltd.) as the solvent, 1.262 g (10 mmol, Tokyo Chemical Co., Ltd.), 1.632 g (10 mmol, Tokyo Chemical Co., Ltd.) of morpholinoacetonitrile and 1.6 mL (25.6 mmol, Tokyo Chemical Co., Ltd.) of N-acetyl-L-cysteine ​​and 1.6 mL (25.6 mmol, Tokyo Chemical Co., Ltd.) of hydrazine monohydrate were stirred at room temperature for 7 days to synthesize the Tz1 precursor. The synthesized Tz1 precursor was washed with methanol and recovered. Furthermore, the recovered Tz1 precursor was stirred in dimethyl sulfoxide and deprotonated to synthesize Tz1. Tz1 was vacuum-dried at 60°C for 12 hours to completely remove the solvent.

[0056] Next, the 1H NMR spectrum of Tz1 was measured using a Bruker-500 FT / NMR spectrometer (manufactured by Bruker). This confirmed that the target product was synthesized with high purity. Tz1, as described here, is the molecular compound shown in equation (6) below.

[0057]

[0058] (Synthesis Example 7) [Synthesis of 3,6-Bis(morpholin-4-ethyl)-1,2,4,5-tetrazine (Tz2)] Following a report previously published by the inventors (M. Melguizo et al., Dalton Trans., 2018, 47, 3329.), 5.2 g (37 mmol, Tokyo Chemical Industry Co., Ltd.), 6.12 g (37.5 mmol, Tokyo Chemical Industry Co., Ltd.), and 26.8 mL (55.1 mmol, Tokyo Chemical Industry Co., Ltd.) of morpholine, N-2-cyanoethyl)morpholine, and 26.8 mL (55.1 mmol, Tokyo Chemical Industry Co., Ltd.) of hydrazine monohydrate were stirred at room temperature for 7 days under a nitrogen atmosphere to synthesize a Tz2 precursor. The synthesized Tz2 precursor was recovered by extraction with dichloromethane. Furthermore, the recovered Tz2 precursor was stirred in a methanol / dimethyl sulfoxide mixed solvent and deprotonated to synthesize Tz2. Tz2 was vacuum-dried at 60°C for 12 hours to completely remove the solvent.

[0059] Next, the 1H NMR spectrum of Tz2 was measured using a Bruker-500 FT / NMR spectrometer (manufactured by Bruker). This confirmed that the target product was synthesized with high purity. The Tz2 described here is the molecular compound shown in equation (7) below.

[0060]

[0061] (Example 1) [Preparation of TMA(Cl)-PF(Tz2) composite film (4:1)] The TMA(Cl)-PF obtained in Synthesis Example 4 and the Tz2 obtained in Synthesis Example 7 were mixed so that the molar ratio of trimethylammonium (TMA) to Tz2 was 4:1. This mixture was then dissolved in dimethyl sulfoxide (manufactured by Kanto Chemical Co., Ltd.) to a solid content of approximately 3% by mass to obtain a homogeneous solution. The above manufacturing method involves dissolving the anion exchange resin in a solvent to prepare an anion exchange resin solution, dissolving the electron-deficient π-conjugated molecule compound in a solvent to prepare a molecular solution, and then mixing the anion exchange resin solution and the molecular solution to prepare a mixed solution. After pouring the mixed solution onto a petri dish, the solvent was evaporated on a hot plate (Corning PC-420D) at 70°C to form a film. The shape of the obtained film is summarized in Table 1 below, and a photograph of its appearance is shown in Figure 21(a).

[0062] (Example 1A) [Fabrication of TMA(Cl)-PF(Tz2) composite film (80°C hot plate)] TMA(Cl)-PF obtained in Synthesis Example 4 and Tz2 obtained in Synthesis Example 7 were mixed so that the molar ratio of trimethylammonium (TMA) to Tz2 was 4:1. This mixture was dissolved in dimethyl sulfoxide (manufactured by Kanto Chemical Co., Ltd.) to a solid content of approximately 3% by mass to obtain a homogeneous solution. The mixed solution was poured onto a petri dish and then deposited on a hot plate (Corning PC-420D) at 80°C to evaporate the solvent and form a film. The shapes of the obtained films are summarized in Table 1.

[0063] (Example 1B) [Fabrication of TMA(Cl)-PF(Tz2) composite film (60°C hot plate)] TMA(Cl)-PF obtained in Synthesis Example 4 and Tz2 obtained in Synthesis Example 7 were mixed so that the molar ratio of trimethylammonium (TMA) to Tz2 was 4:1. This mixture was then dissolved in dimethyl sulfoxide (manufactured by Kanto Chemical Co., Ltd.) to a solid content of approximately 3% by mass to obtain a homogeneous solution. The mixed solution was poured onto a petri dish, and the solvent was evaporated on a hot plate (Corning PC-420D) at 60°C to form a film. The shapes of the obtained films are summarized in Table 1.

[0064] (Example 1C) [Fabrication of TMA(Cl)-PF(Tz2) composite film (70°C constant temperature bath)] TMA(Cl)-PF obtained in Synthesis Example 4 and Tz2 obtained in Synthesis Example 7 were mixed so that the molar ratio of trimethylammonium (TMA) to Tz was 4:1. This mixture was dissolved in dimethyl sulfoxide (manufactured by Kanto Chemical Co., Ltd.) to a solid content of approximately 3% by mass to obtain a homogeneous solution. The mixed solution was poured onto a petri dish and then the solvent was evaporated in a constant temperature bath (DKS200, manufactured by Yamato Scientific Co., Ltd.) at 80°C to form a film. The shape of the obtained film is summarized in Table 1.

[0065] (Example 1D) [Fabrication of TMA(Cl)-PF(Tz2) composite film (vacuum drying at room temperature)] TMA(Cl)-PF obtained in Synthesis Example 4 and Tz2 obtained in Synthesis Example 7 were mixed so that the molar ratio of trimethylammonium (TMA) to Tz2 was 4:1. The mixture was dissolved in dimethyl sulfoxide (manufactured by Kanto Chemical Co., Ltd.) to a solid content of approximately 3% by mass to obtain a homogeneous solution. The mixed solution was poured onto a petri dish and the solvent was evaporated at room temperature in a vacuum dryer (DP200, manufactured by Yamato Scientific Co., Ltd.) to form a film. The shape of the obtained film is summarized in Table 1.

[0066] (Example 1E) [Fabrication of TMA(Cl)-PF(Tz2) composite film (vacuum drying at 70°C)] TMA(Cl)-PF obtained in Synthesis Example 4 and Tz2 obtained in Synthesis Example 7 were mixed so that the molar ratio of trimethylammonium (TMA) to Tz2 was 4:1. This mixture was dissolved in dimethyl sulfoxide (manufactured by Kanto Chemical Co., Ltd.) to a solid content of approximately 3% by mass to obtain a homogeneous solution. The mixed solution was poured onto a petri dish, and the solvent was evaporated at 80°C in a vacuum dryer (DP200, manufactured by Yamato Scientific Co., Ltd.) to form a film. The shape of the obtained film is summarized in Table 1.

[0067] As shown in Table 1, the results of Example 1 and Reference Examples 1A to 1E indicate that it is important to carefully evaporate the solvent while heating to an appropriate temperature in air rather than under reduced pressure during film formation. It is preferable to form the film while heating at around 70°C at atmospheric pressure and evaporating the solvent. Since the film curved when heated at 60°C and 80°C, it is considered desirable that the temperature for evaporating the solvent be around 65 to 75°C.

[0068] (Comparative Example 2a) [Preparation of TMA(Cl)-PF(TzC) composite film (2:1, methanol / chloroform)] TMA(Cl)-PF obtained in Synthesis Example 4 and 3,6-diphenyl-1,2,4,5-tetrazine (TzC) (manufactured by Tokyo Chemical Industry Co., Ltd.) were mixed so that the molar ratio of trimethylammonium (TMA) to TzC was 2:1. This mixture was then dissolved in a mixed solution of methanol (manufactured by Kanto Chemical Co., Ltd.) and chloroform (manufactured by Kanto Chemical Co., Ltd.) (volume ratio 1:3) so that the solid content was approximately 3% by mass. The mixed solution was poured onto a petri dish and left to stand at room temperature to evaporate the solvent and form a film. The shape of the obtained film is summarized in Table 1, and a photograph of its appearance is shown in Figure 21(b). The TzC described here is the molecular compound shown in formula (8) below.

[0069]

[0070] (Comparative Example 2b) [Preparation of TMA(Cl)-PF(TzC) composite film (2:1, methanol / tetrachloroethane)] The TMA(Cl)-PF and TzC (manufactured by Tokyo Chemical Industry Co., Ltd.) obtained in Synthesis Example 4 were mixed so that the molar ratio of trimethylammonium (TMA) to TzC was 2:1, and dissolved in a mixed solution of methanol (manufactured by Kanto Chemical Co., Ltd.) and 1,1,2,2-tetrachloroethane (manufactured by Kanto Chemical Co., Ltd.) (volume ratio 1:1) so that the solid content was approximately 3% by mass. After pouring the mixed solution onto a petri dish, it was left to stand at room temperature to evaporate the solvent and form a film. The shape of the obtained film is summarized in Table 1, and a photograph of its appearance is shown in Figure 21(c).

[0071] (Comparative Example 2c) [Preparation of TMA(Cl)-PF(TzC) composite film (1:1, methanol / chloroform)] TMA(Cl)-PF obtained in Synthesis Example 4 and 3,6-diphenyl-1,2,4,5-tetrazine (TzC) (manufactured by Tokyo Chemical Industry Co., Ltd.) were mixed so that the molar ratio of trimethylammonium (TMA) to TzC was 1:1. This mixture was then dissolved in a mixed solution of methanol (manufactured by Kanto Chemical Co., Ltd.) and chloroform (manufactured by Kanto Chemical Co., Ltd.) (volume ratio 1:3) so that the solid content was approximately 3% by mass. The mixed solution was poured onto a petri dish and left to stand at room temperature to evaporate the solvent and form a film. The shape of the obtained film is summarized in Table 1, and a photograph of its appearance is shown in Figure 21(d).

[0072] (Comparative Example 2d) [Preparation of TMA(Cl)-PF(TzC) composite film (1:1, methanol / tetrachloroethane)] The TMA(Cl)-PF and TzC (manufactured by Tokyo Chemical Industry Co., Ltd.) obtained in Synthesis Example 4 were mixed so that the molar ratio of trimethylammonium (TMA) to TzC was 1:1, and dissolved in a mixed solution of methanol (manufactured by Kanto Chemical Co., Ltd.) and 1,1,2,2-tetrachloroethane (manufactured by Kanto Chemical Co., Ltd.) (volume ratio 1:1) so that the solid content was approximately 3% by mass. After pouring the mixed solution onto a petri dish, it was left to stand at room temperature to evaporate the solvent and form a film. The shape of the obtained film is summarized in Table 1, and a photograph of its appearance is shown in Figure 22(a).

[0073] (Comparative Example 2e) [Preparation of TMA(Cl)-PF(Tz1) composite film (8:1, methanol / chloroform)] TMA(Cl)-PF obtained in Synthesis Example 4 and Tz1 obtained in Synthesis Example 6 were mixed so that the molar ratio of trimethylammonium (TMA) to Tz1 was 8:1, and dissolved in a mixed solution of methanol (manufactured by Kanto Chemical) and chloroform (manufactured by Kanto Chemical) (volume ratio 1:3) so that the solid content was approximately 3% by mass. The mixed solution was poured onto a petri dish and left to stand at room temperature to evaporate the solvent and form a film. The shape of the obtained film is summarized in Table 1, and a photograph of its appearance is shown in Figure 22(b).

[0074] (Comparative Example 2f) [Preparation of TMA(Cl)-PF(Tz1) composite film (8:1, methanol / tetrachloroethane)] TMA(Cl)-PF obtained in Synthesis Example 4 and Tz1 obtained in Synthesis Example 6 were mixed so that the molar ratio of trimethylammonium (TMA) to Tz1 was 8:1. This mixture was then dissolved in a mixed solution of methanol (manufactured by Kanto Chemical) and 1,1,2,2-tetrachloroethane (manufactured by Kanto Chemical) (volume ratio 1:3) so that the solid content was approximately 3% by mass. The mixed solution was poured onto a petri dish and left to stand at room temperature to allow the solvent to evaporate and form a film. The shape of the obtained film is summarized in Table 1, and a photograph of its appearance is shown in Figure 22(c).

[0075] The mixed solution of TMA-PF and Tz2 used for film formation in Example 1 was a uniform film without precipitates, as shown in Figure 21(a). Therefore, a homogeneous anion exchange resin film could be obtained by forming a film using this mixed solution. In contrast, when we attempted to form films by mixing TMA-PF with Tz1 or TzC in various molar ratios, aggregation of Tz1 or TzC occurred within the film, as shown in the external appearance photographs in Figures 21(b) to 22(c), and a uniform film could not be obtained, resulting in the failure to form a uniform film.

[0076]

[0077] [Measurement of Anionic Conductivity of TMA(Cl)-PF(Tz2) Composite Film (4:1)] The TMA(Cl)-PF(Tz2) composite film (4:1) prepared in (Example 1) was cut into 1cm x 3cm pieces, and the resistance values ​​of various films (at a distance of 1cm between electrodes) were measured by frequency response measurement from 50kHz to 5MHz using an LCR HiTester 3532-50 (HIOKI E.C.). The temperature and humidity during resistance measurement were maintained at 90°C 90%RH, 90°C 60%RH, and 90°C 30%RH, respectively, using a constant temperature and humidity chamber SH-221 (ESPEC), and measurements were taken under each condition. The anionic conductivity of the film was calculated using the following formula: Anionic conductivity [S / cm] = Distance between electrodes [cm] / (Film thickness [cm] × Film width [cm] × Resistance [Ω])

[0078] Figure 23 is an explanatory diagram showing the arrangement of platinum electrodes and anion exchange membrane when measuring anion conductivity. Bar-shaped platinum electrodes are placed parallel to each other along the membrane width direction on one side of the anion exchange membrane surface in the length direction (depth direction) and on the other side of the back surface of the anion exchange membrane in the length direction (depth direction). The distance between electrodes along the direction perpendicular to the membrane width (W) is defined as the inter-electrode distance (D), the cross-sectional area (A) is the area of ​​the surface indicated by the arrow, and the membrane thickness (t) is shown in Figure 23. The aforementioned formula for calculating anion conductivity is given by: σ: anion conductivity (S / cm), D: inter-electrode distance (cm), R: impedance (Ω), and membrane cross-sectional area A (= W × t: cm²). ２ If we assume that σ = D / (R × A), then it can be expressed by the following formula: σ = D / (R × A). The results of the anionic conductivity measurement are summarized in Table 2 below.

[0079] (Example 2) [Preparation of TMA(Cl)-PF(Tz2) composite film (8:1)] The TMA(Cl)-PF obtained in Synthesis Example 4 and the Tz2 obtained in Synthesis Example 7 were mixed so that the molar ratio of trimethylammonium (TMA) to Tz was 8:1. This mixture was dissolved in dimethyl sulfoxide (manufactured by Kanto Chemical Co., Ltd.) to a solid content of approximately 3% by mass to obtain a homogeneous solution. The mixed solution was poured onto a petri dish, and the solvent was evaporated on a hot plate (Corning PC-420D) at 70°C to form a film.

[0080] [Measurement of Anionic Conductivity of TMA(Cl)-PF(Tz2) Composite Film (8:1)] The TMA(Cl)-PF(Tz2) composite film (8:1) prepared in (Example 2) was subjected to anionic conductivity measurements at 90°C 90% RH, 90°C 60% RH, and 90°C 30% RH according to the method described in the paragraph above which the formula for determining anionic conductivity is described. The anionic conductivity measurement results are summarized in Table 2.

[0081] (Example 3) [Preparation of TMA(Cl)-PF(Tz2) composite film (2:1)] The TMA(Cl)-PF obtained in Synthesis Example 4 and the Tz2 obtained in Synthesis Example 7 were mixed so that the molar ratio of trimethylammonium (TMA) to Tz was 2:1. This mixture was dissolved in dimethyl sulfoxide (manufactured by Kanto Chemical Co., Ltd.) to a solid content of approximately 3% by mass to obtain a homogeneous solution. The mixed solution was poured onto a petri dish, and the solvent was evaporated at 70°C on a hot plate (Corning PC-420D) to form a film.

[0082] [Measurement of Anionic Conductivity of TMA(Cl)-PF(Tz2) Composite Film (2:1)] The TMA(Cl)-PF(Tz2) composite film (2:1) prepared in (Example 3) was subjected to anionic conductivity measurements at 90°C 90% RH, 90°C 60% RH, and 90°C 30% RH according to the method described in the paragraph above which the formula for determining anionic conductivity is described. The anionic conductivity measurement results are summarized in Table 2.

[0083] (Comparative Example 3) [Preparation of TMA(Cl)-PF Single Film] The TMA(Cl)-PF obtained in Synthesis Example 4 was dissolved in dimethyl sulfoxide (manufactured by Kanto Chemical Co., Ltd.) to a solid content of approximately 3% by mass to obtain a homogeneous solution. The mixed solution was poured onto a petri dish, and the solvent was evaporated at 70°C on a hot plate (Corning PC-420D) to form a film.

[0084] [Measurement of Anionic Conductivity of TMA(Cl)-PF Single Film] The TMA(Cl)-PF single film prepared in (Comparative Example 3) was subjected to anionic conductivity measurements at 90°C 90% RH, 90°C 60% RH, and 90°C 30% RH according to the method described in the paragraph above which the formula for determining anionic conductivity is described. The anionic conductivity measurement results are summarized in Table 2.

[0085] (Example 4) [Preparation of TMA(Br)-PF(Tz2) composite film (8:1)] The TMA(Br)-PF obtained in Synthesis Example 2 and the Tz2 obtained in Synthesis Example 7 were mixed so that the molar ratio of trimethylammonium (TMA) to Tz was 8:1. Dimethyl sulfoxide (manufactured by Kanto Chemical Co., Ltd.) was dissolved in it so that the solid content was approximately 3% by mass to obtain a homogeneous solution. The mixed solution was poured onto a petri dish, and the solvent was evaporated on a hot plate (Corning PC-420D) at 70°C to form a film.

[0086] [Measurement of Anionic Conductivity of TMA(Br)-PF(Tz2) Composite Film (8:1)] The TMA(Br)-PF(Tz2) composite film (8:1) prepared in (Example 4) was subjected to the method described in the paragraph above, which outlines the formula for determining anionic conductivity, and the anionic conductivity was calculated at 90°C 90% RH, 90°C 60% RH, and 90°C 30% RH. The results of the anionic conductivity measurement are summarized in Table 2.

[0087] (Example 5) [Preparation of TMA(Br)-PF(Tz2) composite film (4:1)] The TMA(Br)-PF obtained in Synthesis Example 2 and the Tz2 obtained in Synthesis Example 7 were mixed so that the molar ratio of trimethylammonium (TMA) to Tz was 4:1. This mixture was dissolved in dimethyl sulfoxide (manufactured by Kanto Chemical Co., Ltd.) to a solid content of approximately 3% by mass to obtain a homogeneous solution. The mixed solution was poured onto a petri dish, and the solvent was evaporated on a hot plate (Corning PC-420D) at 70°C to form a film. A photograph of the appearance is shown in Figure 22(e).

[0088] [Measurement of Anionic Conductivity of TMA(Br)-PF(Tz2) Composite Film (4:1)] The TMA(Br)-PF(Tz2) composite film (4:1) prepared in Example 5 was subjected to the method described in the paragraph above, which specifies the formula for determining anionic conductivity, and the anionic conductivity was calculated at 90°C 90% RH, 90°C 60% RH, and 90°C 30% RH. The results of the anionic conductivity measurement are summarized in Table 2.

[0089] (Example 6) [Preparation of TMA(Br)-PF(Tz2) composite film (2:1)] The TMA(Br)-PF obtained in Synthesis Example 2 and the Tz2 obtained in Synthesis Example 7 were mixed so that the molar ratio of trimethylammonium (TMA) to Tz was 2:1. This mixture was dissolved in dimethyl sulfoxide (manufactured by Kanto Chemical Co., Ltd.) to a solid content of approximately 3% by mass to obtain a homogeneous solution. The mixed solution was poured onto a petri dish, and the solvent was evaporated on a hot plate (Corning PC-420D) at 70°C to form a film.

[0090] [Measurement of Anionic Conductivity of TMA(Br)-PF(Tz2) Composite Film (2:1)] The TMA(Br)-PF(Tz2) composite film (2:1) prepared in (Example 6) was subjected to the calculation of anionic conductivity at 90°C 90% RH, 90°C 60% RH, and 90°C 30% RH according to the method described in the paragraph above which the formula for determining anionic conductivity is described. The results of the anionic conductivity measurement are summarized in Table 2.

[0091] (Comparative Example 4) [Preparation of TMA(Br)-PF Single Film] The TMA(Br)-PF obtained in Synthesis Example 2 was dissolved in dimethyl sulfoxide (manufactured by Kanto Chemical Co., Ltd.) to a solid content of approximately 3% by mass to obtain a homogeneous solution. The mixed solution was poured onto a petri dish, and the solvent was evaporated at 70°C on a hot plate (Corning PC-420D) to form a film. A photograph of the appearance is shown in Figure 22(d).

[0092] [Measurement of Anionic Conductivity of TMA(Br)-PF Single Film] The TMA(Br)-PF single film prepared in (Comparative Example 3) was measured for anionic conductivity at 90°C 90% RH, 90°C 60% RH, and 90°C 30% RH according to the method described in the paragraph above which the formula for determining anionic conductivity is described. The results of the anionic conductivity measurement are summarized in Table 2.

[0093] (Example 7) [Preparation of TMA(I)-PF(Tz2) composite film (8:1)] The TMA(I)-PF obtained in Synthesis Example 5 and the Tz2 obtained in Synthesis Example 7 were mixed so that the molar ratio of trimethylammonium (TMA) to Tz was 8:1. This mixture was dissolved in dimethyl sulfoxide (manufactured by Kanto Chemical Co., Ltd.) to a solid content of approximately 3% by mass to obtain a homogeneous solution. The mixed solution was poured onto a petri dish, and the solvent was evaporated at 70°C on a hot plate (Corning PC-420D) to form a film.

[0094] [Measurement of Anionic Conductivity of TMA(I)-PF(Tz2) Composite Film (8:1)] The anionic conductivity of the TMA(I)-PF(Tz2) composite film (8:1) prepared in Example 7 was calculated at 90°C and 90°C and 60°C according to the method described in the paragraph above, which describes the formula for determining anionic conductivity. The results of the anionic conductivity measurement are summarized in Table 2.

[0095] (Example 8) [Preparation of TMA(I)-PF(Tz2) composite film (4:1)] The TMA(I)-PF obtained in Synthesis Example 5 and the Tz2 obtained in Synthesis Example 7 were mixed so that the molar ratio of trimethylammonium (TMA) to Tz was 4:1. This mixture was dissolved in dimethyl sulfoxide (manufactured by Kanto Chemical Co., Ltd.) to a solid content of approximately 3% by mass to obtain a homogeneous solution. The mixed solution was poured onto a petri dish, and the solvent was evaporated on a hot plate (Corning PC-420D) at 70°C to form a film. A photograph of the appearance is shown in Figure 22(f).

[0096] [Measurement of Anionic Conductivity of TMA(I)-PF(Tz2) Composite Film (4:1)] The anionic conductivity of the TMA(I)-PF(Tz2) composite film (4:1) prepared in Example 8 was calculated at 90°C and 90°C and 60°C according to the method described in the paragraph above, which describes the formula for determining anionic conductivity. The results of the anionic conductivity measurement are summarized in Table 2.

[0097] (Example 9) [Preparation of TMA(I-PF(Tz2) composite film (2:1)] The TMA(I-PF) obtained in Synthesis Example 5 and the Tz2 obtained in Synthesis Example 7 were mixed so that the molar ratio of trimethylammonium (TMA) to Tz was 2:1. Dimethyl sulfoxide (manufactured by Kanto Chemical Co., Ltd.) was dissolved in it so that the solid content was about 3% by mass to obtain a homogeneous solution. The mixed solution was poured onto a petri dish, and the solvent was evaporated on a hot plate (Corning PC-420D) at 70°C to form a film.

[0098] [Measurement of Anionic Conductivity of TMA(I)-PF(Tz2) Composite Film (2:1)] The anionic conductivity of the TMA(I)-PF(Tz2) composite film (2:1) prepared in (Example 9) was calculated at 90°C 90% RH and 90°C 60% RH according to the method described in the paragraph above which the formula for determining anionic conductivity is described. The results of the anionic conductivity measurement are summarized in Table 2.

[0099] (Comparative Example 5) [Preparation of TMA(I)-PF Single Film] The TMA(I)-PF obtained in Synthesis Example 5 was dissolved in dimethyl sulfoxide (manufactured by Kanto Chemical Co., Ltd.) to a solid content of approximately 3% by mass to obtain a homogeneous solution. The mixed solution was poured onto a petri dish, and the solvent was evaporated at 70°C on a hot plate (Corning PC-420D) to form a film.

[0100] [Measurement of Anionic Conductivity of TMA(Br)-PF Single Film] The TMA(Br)-PF single film prepared in (Comparative Example 3) was measured for anionic conductivity at 90°C and 90°C and 60°C according to the method described in the paragraph above, which describes the formula for determining anionic conductivity. The results of the anionic conductivity measurement are summarized in Table 2.

[0101]

[0102] As shown in Table 2, when TMA(Cl)-PF(Tz2) composite films or TMA(Br)-PF(Tz2) composite films were fabricated from a solution in which TMA-PF and Tz2 were mixed in a solvent in a molar ratio of 2:1 to 8:1, they exhibited excellent anionic conductivity in environments ranging from high humidity to low humidity.

[0103] (Example 10) [Preparation of TMA(OH)-PF(Tz2) composite membrane (4:1)] The TMA(Cl)-PF(Tz2) composite membrane (4:1) obtained in Synthesis Example 1 was placed in a glove bag (manufactured by AS ONE) filled with dry nitrogen or humidified nitrogen, and immersed in a 1 M sodium hydroxide aqueous solution (manufactured by Kanto Chemical Co., Ltd.) at room temperature for 24 hours to completely remove the counterions OH － This was replaced to obtain a TMA(OH)-PF(Tz2) composite film (4:1).

[0104] [Measurement of Anionic Conductivity of TMA(OH)-PF(Tz2) Composite Film (4:1)] The TMA(OH)-PF(Tz2) composite film (4:1) prepared in Example 10 was subjected to impedance measurement according to the method described in the paragraph above which the formula for determining anionic conductivity is described, and the anionic conductivity was measured at 25°C 37% RH (humidified nitrogen atmosphere) and 25°C 14% RH (dry nitrogen atmosphere). The anionic conductivity measurement results are summarized in Table 3 below.

[0105] (Comparative Example 6) [Preparation of TMA(OH)-PF single membrane] The TMA(Cl)-PF single membrane obtained in Comparative Example 3 was placed in a glove bag (manufactured by AS ONE) filled with dry nitrogen or humidified nitrogen, and immersed in a 1 M sodium hydroxide aqueous solution (manufactured by Kanto Chemical Co., Ltd.) at room temperature for 24 hours to completely remove the counterions OH － This was replaced to obtain a TMA(OH)-PF monolayer film.

[0106] [Measurement of Anionic Conductivity of TMA(OH)-PF Single Film] The TMA(OH)-PF single film prepared in (Comparative Example 6) was subjected to impedance measurement according to the method described in the paragraph above which the formula for determining anionic conductivity is described, and the anionic conductivity was measured at 25°C 37% RH (humidified nitrogen atmosphere) and 25°C 14% RH (dry nitrogen atmosphere). The results of the anionic conductivity measurement are summarized in Table 3.

[0107]

[0108] As shown in Table 3, the TMA(OH)-PF(Tz2) composite film exhibited superior anionic conductivity in low-humidity environments compared to the TMA(OH)-PF single film.

[0109] (Example 11) [Alkali Stability Test of TMA(OH)-PF(Tz2) Composite Film (4:1)] The TMA(OH)-PF(Tz2) composite film (4:1) prepared in Example 10 was immersed in an 8M sodium hydroxide aqueous solution at 80°C for 72 hours. After immersion, it was washed with pure water in a glove bag under a nitrogen atmosphere, and impedance measurements were performed according to the method described in the paragraph above which the formula for determining anionic conductivity is described, and the anionic conductivity at 25°C and 14% RH (dry nitrogen atmosphere) was measured. The results of the anionic conductivity measurement before and after the alkali stability test are shown in Table 4 below. The same results were obtained before and after immersion in an 8M sodium hydroxide aqueous solution at 80°C for 72 hours. 1 1H NMR measurements were performed. The ratio of protons derived from the anion exchange group to protons in the main chain was calculated from the integral values, and the percentage change in the integral value ratio before and after the stability test is shown in Table 5.

[0110] (Comparative Example 7) [Alkali Stability Test of TMA(OH)-PF Single Film] The TMA(OH)-PF single film prepared in Comparative Example 6 was immersed in an 8M sodium hydroxide aqueous solution at 80°C for 72 hours. After immersion, it was washed with pure water in a glove bag under a nitrogen atmosphere, and impedance measurements were performed according to the method described in the paragraph above which the formula for determining anionic conductivity is described, and the anionic conductivity at 25°C and 14% RH (dry nitrogen atmosphere) was measured. The anionic conductivity before and after the alkali stability test is shown in Table 4. The same immersion in an 8M sodium hydroxide aqueous solution at 80°C for 72 hours was also performed. 1 1H NMR measurements were performed. The ratio of protons derived from the anion exchange group to protons in the main chain was calculated from the integral values, and the percentage change in the integral value ratio before and after the stability test is shown in Table 5.

[0111]

[0112]

[0113] As shown in Table 4, the TMA(OH)-PF(Tz2)(4:1) composite film showed almost no decrease in conductivity before and after the alkaline stability test, demonstrating excellent anionic conductivity. Furthermore, as shown in Table 5, the TMA(OH)-PF(Tz2)(4:1) composite film showed less change in polymer structure before and after the alkaline stability test compared to the TMA(OH)-PF single film, indicating improved alkaline stability due to the composite. As shown in Table 4, the slight improvement in conductivity of TMA(OH)-PF after the alkaline stability test compared to before the test is thought to be due to decomposition progressing in the alkaline test, generating hydrophilic functional groups, etc., which improved water retention capacity at low humidity and resulted in slightly higher conductivity. However, the conductivity of TMA(OH)-PF after the test was lower than that of the TMA(OH)-PF(Tz2)(4:1) composite film, indicating that the TMA(OH)-PF(Tz2)(4:1) composite film is superior.

[0114] (Example 12) [Water electrolysis evaluation of TMA(OH)-PF(Tz2) composite membrane (4:1)] According to the method described in Non-Patent Literature 2, a water electrolysis cell (YNU cell model 21B, electrode area 1 × 1 cm²) was used. ２A clamping pressure of 0.5 MPa was assembled. A TMA(OH)-PF(Tz2) composite membrane (4:1) was used as the anion exchange membrane, and a commercially available Pt / C electrode (0.3 mg cm) was used as the cathode. －２ ,40% Platinum on Vulcan-Carbon Cloth Electrode (W11011), purchased from Fuel Cell Store), commercially available IrO for the anode ２ Ti mesh (purchased from Tanaka Kikinzoku Kogyo) was used. The measurement temperature was 30°C, and the electrolyte was either (1) 1.0 mol / L potassium hydroxide aqueous solution was passed through both the anode and cathode electrodes at a rate of 10 mL / min each, or (2) 1.0 mol / L potassium hydroxide aqueous solution was passed through only the anode at a rate of 10 mL / min (dry cathode operation). Water electrolysis was evaluated using an electrochemical analyzer (BioLogic 9490-F1-TK) at 0.05 A / cm². ２ After conditioning for 60 minutes with a constant current of 0.001 A / cm², ２ From 2.0 A / cm ２ Constant current tests were performed for 3 minutes at each current density, and the potential was measured at that time. The electrolytic test results are shown in Table 6. In addition, the electrochemical impedance method using the current interruption method yielded 0.02 A / cm². ２ From 0.1 A / cm ２ The IR resistance (mainly the ion conduction resistance of the anion exchange membrane) was calculated in the low current density range. Table 7 shows the IR resistance values.

[0115] (Comparative Example 8) [Water electrolysis evaluation of TMA(OH)-PF single membrane] Similar to Example 12, a water electrolysis cell was prepared using a TMA(OH)-PF single membrane as the anion exchange membrane. Water electrolysis evaluation was performed under the same test conditions as in Example 12. The electrolysis test results are shown in Table 6. Similarly, the IR resistance (mainly the ion conduction resistance of the anion exchange membrane) was calculated. The IR resistance values ​​are shown in Table 7.

[0116]

[0117]

[0118] The results shown in Tables 6 and 7 indicate that (1) under bipolar electrolyte supply conditions, there was almost no difference between the TMA(OH)-PF(Tz2)(4:1) composite membrane and the TMA(OH)-PF single membrane, whereas (2) under dry cathode operation, the TMA(OH)-PF(Tz2)(4:1) composite membrane showed significantly lower cell voltage and IR resistance than the TMA(OH)-PF single membrane. This clearly supports the idea that when the water content decreases due to dry cathode operation, efficient conduction occurs in the TMA(OH)-PF(Tz2)(4:1) composite membrane through anion-pi interaction. Based on these test results, it can be said that the TMA(OH)-PF(Tz2) composite membrane is superior for dry cathode operation in anion exchange membrane type hydroelectricity.

[0119] [Simulation using Density Functional Theory (DFT)] Computational chemistry simulations were performed using a Real Computing workstation (RC Viento) and Gaussian software (HPC Systems Version 16) to investigate the anion-pi interaction's effect on anion separation and cation stabilization. The functional and basis functions used were b3lyp and cc-pvdz, respectively.

[0120] (Calculation Example 1) [HTMA] As a model molecule for the TMA group, the structure of one molecule of hexyltrimethylammonium was optimized under vacuum, and the total energy E(HTMA) was calculated. The results are shown in Table 8 below.

[0121] (Calculation Example 2) [HTMA_Cl] One chloride ion was added to the hexyltrimethylammonium optimized in Calculation Example 1, and structural optimization was performed under the same conditions as in Calculation Example 1 under vacuum. The total energy E(HTMA_Cl) and the cation-anion distance were calculated. Multiple initial configurations of the chloride ion were tried to minimize the dependence on the initial configuration. The results are shown in Table 8.

[0122] (Calculation example 3) [HTMA_Cl_1H ２ O] First, H ２ Total energy E(H) ２(O) was calculated under the same conditions as in Calculation Example 1. Subsequently, one water molecule was added to hexyltrimethylammonium chloride optimized in Calculation Example 2, and structure optimization was performed under vacuum, and the total energy E(HTMA_Cl_1H ２ O) and the cation-anion distance were calculated. The dependence on the initial arrangement was minimized by trying multiple initial arrangements of the water molecule. The results are shown in Table 8.

[0123] (Calculation Example 4) [HTMA_Cl_2H ２ O] One more water molecule was added to hexyltrimethylammonium chloride-1H optimized in Calculation Example 3, and structure optimization was performed under vacuum under the same conditions as in Calculation Example 1, and the total energy E(HTMA_Cl_2H ２ O) and the cation-anion distance were calculated. The dependence on the initial arrangement was minimized by trying multiple initial arrangements of the water molecule. The results are shown in Table 8. ２ O) and the cation-anion distance were calculated. The dependence on the initial arrangement was minimized by trying multiple initial arrangements of the water molecule. The results are shown in Table 8.

[0124] (Calculation Example 5) [HTMA_Cl_3H ２ O] One more water molecule was added to hexyltrimethylammonium chloride-2H optimized in Calculation Example 4, and structure optimization was performed under vacuum under the same conditions as in Calculation Example 1, and the total energy E(HTMA_Cl_3H ２ O) and the cation-anion distance were calculated. The dependence on the initial arrangement was minimized by trying multiple initial arrangements of the water molecule. The results are shown in Table 8. ２ O) and the cation-anion distance were calculated. The dependence on the initial arrangement was minimized by trying multiple initial arrangements of the water molecule. The results are shown in Table 8.

[0125] (Calculation Example 6) [Tz1] Structure optimization of one molecule of 3,6-bis(morpholin-4-ylmethyl)-1,2,4,5-tetrazine (Tz1) under vacuum was performed under the same conditions as in Calculation Example 1, and the total energy E(Tz1) was calculated. The results are shown in Table 8.

[0126] (Calculation Example 7) [Tz2] Structure optimization of one molecule of 3,6-bis(morpholin-4-yl)ethyl)-1,2,4,5-tetrazine (Tz2) under vacuum was performed under the same conditions as in Calculation Example 1, and the total energy E(Tz2) was calculated. The results are shown in Table 8.

[0127] (Calculation Example 8) [HTMA_Cl_Tz1] The HTMA_Cl optimized in Calculation Example 2 and the Tz1 optimized in Calculation Example 6 were arranged, and structural optimization was performed under vacuum under the same conditions as in Calculation Example 1 to calculate the total energy E(HTMA_Cl_Tz1) and the cation-anion distance. The dependence on the initial arrangement was minimized by trying multiple initial arrangements of Tz1. Furthermore, the energy change (ΔE) due to the presence or absence of Tz1 was calculated according to the following formula using the total energy E(HTMA_Cl) of HTMA_Cl calculated in Calculation Example 2 and the total energy E(Tz1) of Tz1 calculated in Calculation Example 5. ΔE = E(HTMA_Cl_Tz1) - {E(HTMA_Cl) + E(Tz1)} The results are shown in Table 8.

[0128] (Calculation Example 9) [HTMA_Cl_1H ２ O_Tz1] The HTMA_Cl_1H ２ O optimized in Calculation Example 3 and the Tz1 optimized in Calculation Example 6 were arranged, and structural optimization was performed under vacuum under the same conditions as in Calculation Example 1 to calculate the total energy E(HTMA_Cl_1H ２ O_Tz1) and the cation-anion distance. The dependence on the initial arrangement was minimized by trying multiple initial arrangements of Tz1. Furthermore, the energy change (ΔE) due to the presence or absence of Tz1 was calculated according to the following formula using the total energy E(HTMA_Cl) of HTMA_Cl calculated in Calculation Example 2, the total energy E(H ２ O) of H ２ [[ID=十三]]O calculated in Calculation Example 3, and the total energy E(Tz1) of Tz1 calculated in Calculation Example 5. ΔE = E(HTMA_Cl_1H ２ O_Tz1) - {E(HTMA_Cl) + 1 × E(H ２ O) + E(Tz1)} The results are shown in Table 8.

[0129] (Calculation Example 10) [HTMA_Cl_2H ２ O_Tz1] The HTMA_Cl_2H ２ O optimized in Calculation Example 4 and the Tz1 optimized in Calculation Example 6 were arranged, and structural optimization was performed under vacuum under the same conditions as in Calculation Example 1 to calculate the total energy E(HTMA_Cl_2H ２The cation-anion distance was calculated for O_Tz1. Multiple initial configurations of Tz1 were tried to minimize dependence on the initial configuration. Furthermore, the energy change (ΔE) with and without Tz1 was calculated using the total energy E (HTMA_Cl) calculated in calculation example 2 and the H calculated in calculation example 3. ２ Total energy of O E(H) ２ O), using the total energy E(Tz1) of Tz1 calculated in calculation example 5, the following formula was used to calculate ΔE = E(HTMA_Cl_2H) ２ O_Tz1)-{E(HTMA_Cl)+2×E(H ２ O) + E(Tz1)} The results are shown in Table 8.

[0130] (Calculation example 11) [HTMA_Cl_3H ２ O_Tz1] Optimized HTMA_Cl_3H in Calculation Example 5 ２ O and Tz1 optimized in Calculation Example 6 are placed, and structural optimization is performed under vacuum conditions the same as in Calculation Example 1, and the total energy E(HTMA_Cl_3H) ２ The cation-anion distance between O_Tz1 was calculated. Multiple initial configurations of Tz1 were tried to minimize dependence on the initial configuration. Similar to calculation example 10, the energy change (ΔE) with and without Tz1 was calculated. The results are shown in Table 8.

[0131] (Calculation Example 12) [HTMA_Cl_Tz2] The HTMA_Cl optimized in Calculation Example 2 and the Tz2 optimized in Calculation Example 7 were arranged, and structural optimization under vacuum conditions was performed under the same conditions as in Calculation Example 1, and the total energy E (HTMA_Cl_Tz2) and the cation-anion distance were calculated. Multiple initial arrangements of Tz2 were tried to minimize the dependence on the initial arrangement. As in the case of Calculation Example 8, the energy change (ΔE) with and without Tz2 was calculated. The results are shown in Table 8.

[0132] (Calculation example 13) [HTMA_Cl_1H ２ O_Tz2] Optimized HTMA_Cl_1H in Calculation Example 3 ２ By placing O and the optimized Tz2 from Calculation Example 7, and performing structural optimization under vacuum under the same conditions as Calculation Example 1, the total energy E(HTMA_Cl_1H) ２The cation-anion distance and the O_Tz2 were calculated. Multiple initial configurations of Tz2 were tried to minimize dependence on the initial configuration. Similar to calculation example 10, the energy change (ΔE) with and without Tz2 was calculated. The results are shown in Table 8.

[0133] (Calculation example 14) [HTMA_Cl_2H ２ O_Tz2] Optimized HTMA_Cl_2H in Calculation Example 4 ２ By placing O and the optimized Tz2 from Calculation Example 7, and performing structural optimization under vacuum under the same conditions as Calculation Example 1, the total energy E(HTMA_Cl_2H) ２ The cation-anion distance and the O_Tz2 were calculated. Multiple initial configurations of Tz2 were tried to minimize dependence on the initial configuration. Similar to calculation example 10, the energy change (ΔE) with and without Tz2 was calculated. The results are shown in Table 8.

[0134] (Calculation example 15) [HTMA_Cl_3H ２ O_Tz2] Optimized HTMA_Cl_3H in Calculation Example 5 ２ By placing O and the optimized Tz2 from Calculation Example 7, and performing structural optimization under vacuum under the same conditions as Calculation Example 1, the total energy E(HTMA_Cl_3H) ２ The cation-anion distance and the O_Tz2 were calculated. Multiple initial configurations of Tz2 were tried to minimize dependence on the initial configuration. Similar to calculation example 10, the energy change (ΔE) with and without Tz2 was calculated. The results are shown in Table 8.

[0135] (Calculation Example 16) [HTMA_Br] One bromide ion was added to the hexyltrimethylammonium optimized in Calculation Example 1, and structural optimization was performed under the same conditions as in Calculation Example 1 under vacuum. The total energy E(HTMA_Br) and the cation-anion distance were calculated. Multiple initial configurations of the bromide ion were tried to minimize the dependence on the initial configuration. The results are shown in Table 8.

[0136] (Calculation example 17) [HTMA_Br_1H ２ O] Add one water molecule to the hexyltrimethylammonium bromide optimized in Calculation Example 16, and perform structural optimization under vacuum conditions the same as in Calculation Example 1, and the total energy E(HTMA_Br_1H２ The cation-anion distance was calculated for O). Multiple initial configurations of water molecules were tested to minimize dependence on the initial configuration. The results are shown in Table 8.

[0137] (Calculation example 18) [HTMA_Br_2H ２ O] Optimized hexyltrimethylammonium bromide 1H in calculation example 17 ２ By adding one more water molecule to O and performing structural optimization under vacuum conditions the same as in calculation example 1, the total energy E(HTMA_Br_2H) was obtained. ２ The cation-anion distance was calculated for O). Multiple initial configurations of water molecules were tested to minimize dependence on the initial configuration. The results are shown in Table 8.

[0138] (Calculation example 19) [HTMA_Br_3H ２ O] Optimized hexyltrimethylammonium bromide 2H in calculation example 18 ２ By adding one more water molecule to O, and performing structural optimization under vacuum conditions the same as in calculation example 1, the total energy E(HTMA_Br_3H) was obtained. ２ The cation-anion distance was calculated for O). Multiple initial configurations of water molecules were tested to minimize dependence on the initial configuration. The results are shown in Table 8.

[0139] (Calculation Example 20) [HTMA_Br_Tz2] The HTMA_Br optimized in Calculation Example 16 and the Tz2 optimized in Calculation Example 7 were arranged, and structural optimization under vacuum conditions was performed under the same conditions as in Calculation Example 1, and the total energy E (HTMA_Br_Tz2) and the cation-anion distance were calculated. Multiple initial arrangements of Tz2 were tried to minimize the dependence on the initial arrangement. As in the case of Calculation Example 10, the energy change (ΔE) with and without Tz2 was calculated. The results are shown in Table 8.

[0140] (Calculation example 21) [HTMA_Br_1H ２In Calculation Example 17, the optimized HTMA_Br_1H2O was used, and in Calculation Example 7, the optimized Tz2 was used. Structural optimization was performed under vacuum conditions, the same as in Calculation Example 1, and the total energy E(HTMA_Br_1H2O_Tz2) and the cation-anion distance were calculated. Multiple initial configurations of Tz2 were tried to minimize dependence on the initial configuration. As in Calculation Example 10, the energy change (ΔE) with and without Tz2 was calculated. The results are shown in Table 8.

[0141] (Calculation example 22) [HTMA_Br_2H ２ O_Tz2] Optimized HTMA_Br_2H in Calculation Example 18 ２ By placing O and the optimized Tz2 from Calculation Example 7, and performing structural optimization under vacuum conditions the same as in Calculation Example 1, the total energy E(HTMA_Br_2H) ２ The cation-anion distance and the O_Tz2 were calculated. Multiple initial configurations of Tz2 were tried to minimize dependence on the initial configuration. Similar to calculation example 10, the energy change (ΔE) with and without Tz2 was calculated. The results are shown in Table 8.

[0142] (Calculation example 23) [HTMA_Br_3H ２ O_Tz2] Optimized HTMA_Br_3H in Calculation Example 19 ２ By placing O and Tz2 optimized in Calculation Example 7, and performing structural optimization under vacuum under the same conditions as in Calculation Example 1, the total energy E(HTMA_Br_3H) ２ The cation-anion distance and the O_Tz2 were calculated. Multiple initial configurations of Tz2 were tried to minimize dependence on the initial configuration. Similar to calculation example 10, the energy change (ΔE) with and without Tz2 was calculated. The results are shown in Table 8.

[0143]

[0144] Figure 24 shows the results of the calculation described above, where the counterion is Cl － In that case, the N atom of the ion exchange group shown in equation (9) below and Cl －The calculation results for ion distance are shown for both cases: when either Tz2 or Tz1 is used as the molecular compound exhibiting anion-pi interaction, and when neither Tz2 nor Tz1 is used (w / out Tz).

[0145]

[0146] In the calculation example shown in Figure 24, w / Tz2 represents the calculation result when a molecular compound exhibiting anion-pi interaction (Tz2) and an anion exchange resin model (hexyltrimethylammonium chloride: HTMA_Cl) are combined. w / Tz1 represents the calculation result when a molecular compound exhibiting anion-pi interaction (Tz1) and an anion exchange resin model (HTMA_Cl) are combined. w / out Tz represents the calculation result of the anion exchange resin model (HTMA_Cl) when a molecular compound exhibiting anion-pi interaction is not combined.

[0147] Similarly, the counterion ion Br － In that case, the N atom and Br of the ion exchange group shown in equation (9) － Figure 26 shows the calculation results for ion distance, both when using one of the molecular compounds exhibiting anion-pi interaction (Tz2, Tz1, or Tz) and when not using one. In Figure 26, w / Tz2 shows the calculation results when combining the molecular compound exhibiting anion-pi interaction (Tz2) with the anion exchange resin model (hexyltrimethylammonium bromide: HTMA_Br). w / Tz1 shows the calculation results when combining the molecular compound exhibiting anion-pi interaction (Tz1) with the anion exchange resin model (HTMA_Br). w / out Tz shows the calculation results for the anion exchange resin model (HTMA_Br) without combining it with a molecular compound exhibiting anion-pi interaction.

[0148] Furthermore, counterions － In this case, the N atom and I of the ion exchange group shown in equation (9) －Figure 28 shows the calculation results for ion distance, both when using either Tz2 or Tz as a molecular compound exhibiting anion-pi interaction, and when not using either. Of the calculation results shown in Figure 28, w / Tz2 shows the calculation result when combining the molecular compound exhibiting anion-pi interaction (Tz2) with the anion exchange resin model (hexyltrimethylammonium iodide: HTMA_I). w / out Tz shows the calculation result for the anion exchange resin model (HTMA_I) when the molecular compound exhibiting anion-pi interaction is not combined.

[0149] Furthermore, Figure 25 shows that in the calculation results mentioned above, the counterion is Cl － The calculation results for the stabilization energy in this case are shown, and Figure 27 shows the case where the counterion is Br － The calculation results for the stabilization energy in this case are shown below.

[0150] In the calculation example shown in Figure 25, ΔE_Tz2 represents the calculated stabilization energy when a molecular compound exhibiting anion-pi interaction (Tz2) is combined with the anion exchange resin model (HTMA_Cl). ΔE_Tz1 represents the calculated stabilization energy when a molecular compound exhibiting anion-pi interaction (Tz1) is combined with the anion exchange resin model (HTMA_Cl). In the calculation example shown in Figure 27, ΔE_Tz2 represents the stabilization energy result when a molecular compound exhibiting anion-pi interaction (Tz2) is combined with the anion exchange resin model (HTMA_Br), and ΔE_Tz1 represents the stabilization energy result when a molecular compound exhibiting anion-pi interaction (Tz1) is combined with the anion exchange resin model (HTMA_Br).

[0151] The calculation results shown in Figures 24, 26, and 28 provide an indication of the degree of interaction between anion-pi interactions and molecules when a particular molecule is placed at a specific position. In Figures 24, 26, and 28, a horizontal axis of 0 means there is no water, a horizontal axis of 1 means there is one water molecule, a horizontal axis of 2 means there are two water molecules, and a horizontal axis of 3 means there are three water molecules. In the calculation results shown in Figures 24, 26, and 28, the calculated values ​​diverge vertically depending on the presence or absence of Tz when the number of water molecules is the same. The effect is weaker when there are many water molecules, but the fact that divergence occurs vertically even when there are few water molecules or no water molecules indicates that the effect is significant. From these results, it can be inferred that molecular compounds exhibiting anion-pi interactions have the effect of mitigating the electrostatic interaction of anions.

[0152] Figure 29 shows the results of density functional theory (DFT) simulations for tetrazine derivatives, specifically for molecular compounds without a morpholine ring, molecular compounds with one morpholine ring, and molecular compounds with two morpholine rings, regarding the relationship between the N atom and Cl of the ion exchange group. － Ion distance and counterion Cl － The calculation results for the stabilization energy in this case are shown below.

[0153] In Figure 29, Tz2_0morpholine shows the results when a triazine (Tz2_0morpholine) with two hexyl groups introduced as a molecular compound exhibiting anion-pi interaction is combined with the anion exchange resin model (HTMA_Cl). Tz2_1morpholine shows the results when a triazine (Tz2_1morpholine) with one morpholine group and one hexyl group introduced as a molecular compound exhibiting anion-pi interaction is combined with the anion exchange resin model (HTMA_Cl). Tz2_2morpholine shows the results when a triazine (Tz2_2morpholine) with two morpholine groups introduced as a molecular compound exhibiting anion-pi interaction is combined with the anion exchange resin model (HTMA_Cl). From these calculation results, it can be seen that molecular compounds containing two morpholine rings are promising among tetrazine derivatives.

[0154] Table 9 below summarizes the ion exchange capacity results for each anion in a composite anion exchange membrane and a TMA-PF single membrane (w / out Tz2) obtained by incorporating Tz2 obtained in the above-mentioned examples into an ion exchange resin.

[0155]

[0156] As shown in Table 9, compared to the theoretical IEC of a TMA-PF single membrane (w / out Tz2), the composite ion exchange membrane obtained by blending the ion exchange resin and Tz2 in a molar ratio of 8:1 to 2:1 has an ion exchange capacity of approximately 1.5 to 2.0 meq g, which is a balance between conductivity and stability. ―1 It can be seen that this shows an appropriate value. Therefore, it is considered that a blending ratio of ion exchange resin and Tz2 in the range of 8:1 to 2:1 molar ratio is desirable for manufacturing a composite anion exchange membrane.

[0157] In the examples described so far, excellent properties were obtained in a composite anion exchange membrane obtained by compounding the ion exchange resin with Tz2, a tetrazine derivative having two morpholine rings on the tetrazine skeleton. This result may be due to the fact that a common solvent was obtained for both the anion exchange resin and Tz2 with two morpholine rings. However, according to simulations using density functional theory (DFT), as shown in Figure 25, even with tetrazine derivatives that do not have morpholine rings, and tetrazine derivatives that have only one morpholine ring, Cl － Since dissociation occurs at the interatomic positions of ions, if a common solvent is found, there is a possibility of creating an effective composite anion exchange membrane.

[0158] Figures 30 to 32 are graphs showing the IV characteristics measured when the apparatus configured as shown in Figure 2, using a TMA(OH)-PF(Tz2) composite membrane and a TMA(OH)-PF single membrane with a molar ratio of (4:1), was operated in a dry cathode state in the Tafel region. In the calculation examples shown in Figures 30 to 32, those described as "bothside" indicate (1) the results of bipolar electrolyte supply, and those described as "drycathode" indicate (2) the results of dry cathode operation. From the results shown in Figures 30 to 32, it was confirmed that using a TMA(OH)-PF(Tz2) composite membrane resulted in high anionic conductivity during dry cathode operation and a reduction in activation overpotential due to water diffusion, as seen from the comparison of the Tafel plot and the IR component. In particular, during dry cathode operation, TMA-PF w / Tz2 with composite interacting molecules exhibits a significantly lower electrolysis voltage. Furthermore, the IR resistance, as shown in Figure 32, has also decreased significantly. This can be interpreted as an effect of the interaction molecule complexation.

[0159] (Example 13) [Alkali stability test of TMA(OH)-PF(Tz2) composite membrane (4:1)] The TMA(OH)-PF(Tz2) composite membrane (4:1) prepared in Example 10 was immersed in an 8M sodium hydroxide aqueous solution at 80°C for 720 hours. After immersion, it was immersed in a 1M sodium chloride aqueous solution (prepared from Kanto Chemical Co., Ltd.) at room temperature for 12 hours, and then washed with pure water. Before and after immersion １¹H NMR measurements were performed. The ratio of the main chain protons to the phenolic protons derived from the decomposition products after testing was calculated from the integrated values, and the results are shown in Table 10.

[0160] [Fabrication of TMA(OH)-PF(Tz2) composite membrane (2:1)] The TMA(Cl)-PF(Tz2) composite membrane (2:1) obtained in Example 3 was placed in a glove bag (manufactured by AS ONE Corporation) filled with dry nitrogen, and immersed in a 1M sodium hydroxide aqueous solution (manufactured by Kanto Chemical Co., Ltd.) at room temperature for 24 hours to completely remove the counterions from the OH group. － This was replaced to obtain a TMA(OH)-PF(Tz2) composite film (2:1).

[0161] (Example 14) [Alkali stability test of TMA(OH)-PF(Tz2) composite membrane (2:1)] The TMA(OH)-PF(Tz2) composite membrane (2:1) prepared as described above was immersed in an 8M sodium hydroxide aqueous solution at 80°C for 720 hours. After immersion, it was immersed in a 1M sodium chloride aqueous solution (prepared from Kanto Chemical Co., Ltd.) at room temperature for 12 hours, and then washed with pure water. Before and after immersion １ ¹H NMR measurements were performed. The ratio of the main chain protons to the phenolic protons derived from the decomposition products after testing was calculated from the integrated values, and the results are shown in Table 10.

[0162] (Comparative Example 9) [Alkali Stability Test of TMA(OH)-PF Single Film] The TMA(OH)-PF single film prepared in Comparative Example 6 was immersed in an 8 M sodium hydroxide aqueous solution at 80°C for 720 hours. After immersion, it was immersed in a 1 M sodium chloride aqueous solution (prepared from Kanto Chemical Co., Ltd.) at room temperature for 12 hours, and then washed with water. Before and after immersion １ ¹H NMR measurements were performed. The ratio of the main chain protons to the phenolic protons derived from the decomposition products after testing was calculated from the integral values, and the results are shown in Table 10. Figure 33 shows the results obtained in Examples 13, 14, and Comparative Example 9. １ Figure 34 shows the 1H NMR spectrum. １ The decomposition structure estimated from the 1H NMR spectrum is shown.

[0163]

[0164] As shown in Table 10, the TMA(OH)-PF(Tz2)(4:1) composite film and the TMA(OH)-PF(Tz2)(2:1) composite film showed fewer phenolic protons derived from decomposition products after testing compared to the TMA(OH)-PF single film. This indicates an improvement in alkali stability due to the composite film structure.

[0165] (Example 15) [Dry Alkali Stability Test of TMA(OH)-PF(Tz2) Composite Film (4:1)] The TMA(OH)-PF(Tz2) composite film (4:1) prepared in Example 10 was left to stand under vacuum at room temperature for 48 hours. Before and after the test... １ 1H NMR measurements were performed. The ratio of main chain protons to terminal vinyl protons derived from the decomposition products after testing was calculated from the integral values ​​of both, as shown in Table 11.

[0166] (Example 16) [Dry Alkali Stability Test of TMA(OH)-PF(Tz2) Composite Film (2:1)] The TMA(OH)-PF(Tz2) composite film (2:1) prepared in Example 10 was left to stand under vacuum at room temperature for 48 hours. Before and after the test... １ 1H NMR measurements were performed. The ratio of main chain protons to terminal vinyl protons derived from the decomposition products after testing was calculated from the integral values ​​of both, as shown in Table 11.

[0167] (Comparative Example 10) [Dry Alkali Stability Test of TMA(OH)-PF Single Film] The TMA(OH)-PF single film prepared in Example 10 was left to stand under vacuum at room temperature for 48 hours. Before and after the test... １ 1H NMR measurements were performed. The ratio of main chain protons to terminal vinyl protons derived from the decomposition products after testing was calculated from the integral values ​​of both, as shown in Table 11.

[0168]

[0169] As shown in Table 11, the TMA(OH)-PF(Tz2)(4:1) composite film and the TMA(OH)-PF(Tz2)(2:1) composite film have fewer terminal vinyl protons derived from decomposition products after testing compared with the TMA(OH)-PF single film. This demonstrates improved dry alkali stability due to the composite film structure.

[0170] Figure 35 shows the measurement state in which the sample 31 is contained in a heat-insulated, airtight container 30 capable of reduced pressure evacuation, and a dry alkali accelerated degradation test is being conducted in an anhydrous environment. For samples equivalent to those in Examples 13, 14, and Comparative Example 9, measurement results were obtained after 20 hours in a reduced pressure anhydrous atmosphere at room temperature. Figure 36 shows the results. １ Figure 37 shows the 1H NMR spectrum. １ Figures 38 and 39 show the structural changes (degraded structure) due to Hoffmann elimination, as estimated from the 1H NMR spectrum. The results obtained when a 48-hour dry alkali stability test was performed on the composite film and the individual film mentioned above. １ The 1H NMR spectrum and a magnified section thereof are shown.

[0171] (Example 17) [Water electrolysis evaluation of TMA(OH)-PF(Tz2) composite membrane (4:1)] According to the method described in Non-Patent Literature 2, a water electrolysis cell (YNU cell model 21 B, electrode area 1 × 1 cm²) was used. ２ A galvanic electrode was assembled with a clamping pressure of 1.5 MPa. A TMA(OH)-PF(Tz2) composite membrane (4:1) was used as the anion exchange membrane, a commercially available Ni-Fe electrode (Catrode® alkaline water electrolysis electrode (PGM-free), purchased from Fuel Cell Store) was used as the cathode, and a commercially available Ni-Fe electrode (HXP-an, manufactured by HydroXpand, purchased from Mitsuwa Frontec) was used as the anode. The measurement temperature was 60°C, and a 1.0 mol / L potassium hydroxide aqueous solution was passed through the anode only at a rate of 0.5 mL / min as the electrolyte (dry cathode operation).

[0172] Water electrolysis was evaluated using an electrochemical measuring device (PWR401ML, manufactured by Kikusui Electronics Co., Ltd.), with a voltage sweep of 2.5 mV / s in the range of 1 V to 2.5 V. This was repeated six times for conditioning. After 60 minutes of conditioning, the current was 0.05 A / cm². ２ From 5.0 A / cm ２ Constant current tests were performed at each current density for 1.5 minutes, and the potential was measured at each time. Figure 40 and Table 12 show the results of the electrolytic tests.

[0173] (Example 18) [Evaluation of water electrolysis of TMA(OH)-PF(Tz2) composite membrane (2:1)] A water electrolysis cell was prepared using a TMA(OH)-PF(Tz2) composite membrane (2:1) as the anion exchange membrane, with the same configuration as in Example 17. Water electrolysis was evaluated under the same test conditions as in Example 17. The electrolysis test results are shown in Table 12.

[0174] (Comparative Example 11) [Evaluation of Water Electrolysis of a Single TMA(OH)-PF Membrane] A water electrolysis cell was prepared using a single TMA(OH)-PF membrane as the anion exchange membrane, with the same configuration as in Example 17. Water electrolysis was evaluated under the same test conditions as in Example 17. Figure 40 and Table 12 show the electrolysis test results.

[0175]

[0176] As shown in Table 12, the TMA(OH)-PF(Tz2) composite membrane exhibited a significantly lower cell voltage than the TMA(OH)-PF single membrane. This clearly supports the idea that efficient conduction occurs in the TMA(OH)-PF(Tz2) composite membrane through anion-pi interactions when the water content decreases due to dry cathode operation. Based on these test results, it can be said that the TMA(OH)-PF(Tz2) composite membrane is superior for dry cathode operation in anion exchange membrane type water electrolysis.

[0177] [Preparation of TMA(I)-PF(Tz2) Binder (4:1) Coated Catrode®] The TMA(I)-PF obtained in Synthesis Example 5 and the Tz2 obtained in Synthesis Example 7 were mixed so that the molar ratio of trimethylammonium (TMA) to Tz was 4:1. This mixture was dissolved in a dimethyl sulfoxide (manufactured by Kanto Chemical Co., Ltd.) / methanol mixed solvent (v:v = 1:4) so ​​that the TMA(I)-PF fraction was approximately 3% by mass, and a homogeneous solution was obtained. Catrode® was immersed in this solution for 24 hours. Catrode® was removed from the solution and then vacuum-dried overnight.

[0178] [Preparation of TMA(I)-PF(Tz2) Binder (2:1) Coated Catrode®] The TMA(I)-PF obtained in Synthesis Example 5 and the Tz2 obtained in Synthesis Example 7 were mixed so that the molar ratio of trimethylammonium (TMA) to Tz was 2:1. This mixture was dissolved in a dimethyl sulfoxide (manufactured by Kanto Chemical Co., Ltd.) / methanol mixed solvent (v:v=1:4) so ​​that the TMA(I)-PF fraction was approximately 3% by mass, and a homogeneous solution was obtained. Catrode® was immersed in this solution for 24 hours. Catrode® was removed from the solution and then vacuum-dried overnight.

[0179] [Preparation of TMA(I)-PF Binder Coated Catrode®] The TMA(I)-PF obtained in Synthesis Example 5 was dissolved in a dimethyl sulfoxide (manufactured by Kanto Chemical Co., Ltd.) / methanol mixed solvent (v:v = 1:4) so ​​that the TMA(I)-PF fraction was approximately 3% by mass, and a homogeneous solution was obtained. Catrode® was immersed in the solution for 24 hours. Catrode® was removed from the solution and then vacuum-dried overnight.

[0180] (Example 19) [Water electrolysis evaluation of TMA(I)-PF(Tz2) binder (4:1) coated Catrode®] According to the method described in Non-Patent Literature 2, a water electrolysis cell (YNU cell model 21 B, electrode area 1 × 1 cm²) was used. ２ A clamping pressure of 2.0 MPa was assembled. A commercially available PiperION-A40 (manufactured by Versogen, purchased from K&R Creation) was used as the anion exchange membrane, a previously prepared TMA(I)-PF(Tz2) binder (4:1) coated Catrode (registered trademark) was used as the cathode, and a commercially available Ni-Fe electrode (HXP-an, manufactured by HydroXpand, purchased from Mitsuwa Frontec) was used as the anode.

[0181] The measurement temperature was 60°C, and a 1.0 mol / L potassium hydroxide aqueous solution was passed through the anode only as the electrolyte at a rate of 0.5 mL / min (dry cathode operation). For water electrolysis evaluation, an electrochemical analyzer (Kikusui Electronics PWR401ML) was used to sweep the voltage from 1 V to 2.5 V at a rate of 2.5 mV / s. This was repeated six times for conditioning. After 60 minutes of conditioning, the current was 0.05 A / cm². ２ From 5.0 A / cm ２ Constant current tests were performed at each current density for 1.5 minutes, and the potential was measured at each time. Figure 41 and Table 13 show the results of the electrolytic tests.

[0182] (Example 20) [Water electrolysis evaluation of TMA(I)-PF(Tz2) binder (2:1) coated Catrode (registered trademark)] Similar to Example 19, a water electrolysis cell was prepared using TMA(I)-PF(Tz2) binder (2:1) coated Catrode (registered trademark) as the cathode. Water electrolysis evaluation was performed under the same test conditions as in Example 21. Figure 41 and Table 13 show the electrolysis test results.

[0183] (Comparative Example 12) [Water electrolysis evaluation of TMA(I)-PF coated Catrode®] Similar to Example 19, a water electrolysis cell was prepared using TMA(I)-PF binder coated Catrode® as the cathode. Water electrolysis evaluation was performed under the same test conditions as in Example 19. Figure 41 and Table 13 show the electrolysis test results.

[0184]

[0185] As shown in Table 13, the TMA(I)-PF(Tz2) binder-coated Catrode® exhibited a significantly lower cell voltage than the TMA(I)-PF binder-coated Catrode®. This clearly supports the idea that when the water content decreases due to dry cathode operation, efficient anion conduction occurs in the catalyst layer of the TMA(I)-PF(Tz2) binder-coated Catrode® due to anion-pi interactions. Based on these test results, it can be said that the TMA(I)-PF(Tz2) binder-coated Catrode® is superior for dry cathode operation in anion exchange membrane type water electrolysis.

[0186] [Recast PiperION Single Film Preparation] PiperION-A40 (manufactured by Versogen, purchased from K&R Creation) was dissolved in methanol (manufactured by Kanto Chemical Co., Ltd.) to a solid content of approximately 3% by mass to obtain a homogeneous solution. The mixed solution was poured onto a petri dish, and the solvent was evaporated at room temperature to form a film.

[0187] [Preparation of Recast PiperION (OH) Single-Layer Film] The Recast PiperION single-layer film prepared as described above was immersed in a 1 M sodium hydroxide aqueous solution (prepared from Kanto Chemical Co., Ltd.) at room temperature for 12 hours to exchange the counterion species, thereby obtaining a Recast PiperION (OH) single-layer film having hydroxide ions as counterions.

[0188] [Preparation of PiperION (Tz2) composite film (4:1)] PiperION-A40 (manufactured by Versogen, purchased from K&R Creation) and Tz2 obtained in Synthesis Example 7 were mixed so that the molar ratio of piperidinium cation (Pip) to Tz2 was 4:1. The mixture was then dissolved in methanol (manufactured by Kanto Chemical Co., Ltd.) to a solid content of approximately 3% by mass to obtain a homogeneous solution. The mixed solution was poured onto a petri dish, and the solvent was evaporated at room temperature to form a film.

[0189] [Preparation of PiperION(OH)(Tz2) composite membrane (4:1)] The PiperION(Tz2) composite membrane (4:1) obtained in the previous example was immersed in a 1M sodium hydroxide aqueous solution (prepared from Kanto Chemical Co., Ltd.) at room temperature for 12 hours to exchange the counterion species, thereby obtaining a PiperION(OH)(Tz2) composite membrane (4:1) having hydroxide ions as counterions.

[0190] (Example 21) Dry Alkali Stability Test of PiperION(OH)(Tz2) Composite Film (4:1) The PiperION(OH)(Tz2) composite film (4:1) prepared in the previous example was left to stand under vacuum at room temperature for 48 hours. Before and after the test... １¹H NMR measurements and ion exchange capacity measurements were performed. The ratio of the main chain protons to the protons derived from the piperidinium cation (Pip) after testing was calculated from the integral values ​​of both, and the ion exchange capacity maintenance rate is shown in Table 14.

[0191] (Comparative Example 13) [Dry Alkali Stability Test of Recast PiperION (OH) Single Film] The previously prepared Recast PiperION (OH) single film was left to stand under vacuum at room temperature for 48 hours. Before and after the test... １ ¹H NMR measurements and ion exchange capacity measurements were performed. The ratio of the main chain protons to the protons derived from the piperidinium cation (Pip) after testing was calculated from the integral values ​​of both, and the ion exchange capacity maintenance rate is shown in Table 14.

[0192] [Preparation of PiperION(OH)-A40] PiperION-A40 was immersed in a 1M sodium hydroxide aqueous solution (prepared from Kanto Chemical Co., Ltd.) at room temperature for 12 hours to exchange the counterion species, and PiperION(OH)-A40 having hydroxide ions as counterions was obtained.

[0193] (Comparative Example 14) [Dry Alkali Stability Test of PiperION(OH)-A40] PiperION(OH)-A40 was left standing under vacuum at room temperature for 48 hours. Before and after the test １ ¹H NMR measurements and ion exchange capacity measurements were performed. The ratio of the main chain protons to the protons derived from the piperidinium cation (Pip) after testing was calculated from the integral values ​​of both, and the ion exchange capacity retention rate is shown in Table 14. Figure 42 shows the results of 48 hours of vacuum degradation of each film obtained as described above. １ Figure 43 shows the 1H NMR spectrum. １ This shows the structural changes (degraded structure) of PiperION due to Hoffmann elimination, as estimated from the 1H NMR spectrum.

[0194]

[0195] As shown in Table 14, the PiperION (Tz2) composite film (4:1) produced more piperidinium cations (Pip) after testing compared to the Recast PiperION single film, demonstrating improved dry alkali stability due to the composite film structure.

[0196] Figure 44 shows the temperature dependence of anionic conductivity after dry alkali stability testing of the PiperION-A40 film, Recast PiperION single film, and PiperION (Tz2) composite film (4:1) in a high humidity environment of 95% RH.

[0197] Figure 44 shows that the PiperION (Tz2) composite film (4:1) has a higher retention rate of anionic conductivity after dry alkali stability testing compared to the Recast PiperION single film. This indicates that the anionic-pi interaction contributes to the improvement of stability.

[0198] (Example 22) [Evaluation of water electrolysis of PiperION(OH)(Tz2) composite membrane (4:1)] According to the method described in Non-Patent Literature 2, a water electrolysis cell (YNU cell model 21 B, electrode area 1 × 1 cm²) was used. ２ A composite membrane (4:1) of PiperION(OH)(Tz2) was assembled as the anion exchange membrane, a commercially available Ni-Fe electrode (Catrode® alkaline water electrolysis electrode (PGM-free), purchased from Fuel Cell Store) was used for the cathode, and a commercially available Ni-Fe electrode (HXP-an, HydroXpand, purchased from Mitsuwa Frontech) was used for the anode.

[0199] The measurement temperature was 60°C, and a 1.0 mol / L potassium hydroxide aqueous solution was passed through only the anode at a rate of 0.5 mL / min (dry cathode operation). For water electrolysis evaluation, a voltage sweep was performed in the range of 1 V to 2.5 V at 2.5 mV / s using an electrochemical measuring device (Kikusui Electronics PWR401ML). This was repeated six times for conditioning. After 60 minutes of conditioning, the current was 0.05 A / cm². ２ From 5.0 A / cm ２ Constant current tests were performed at each current density for 1.5 minutes, and the potential was measured at each time. Figure 45 and Table 15 show the results of the electrolytic tests.

[0200] (Comparative Example 15) [Evaluation of Water Electrolysis with Recast PiperION (OH) Single Membrane] A water electrolysis cell was prepared using the same configuration as in Example 22, with a Recast PiperION (OH) single membrane as the anion exchange membrane. Water electrolysis was evaluated under the same test conditions as in Example X. Figure 45 and Table 15 show the electrolysis test results.

[0201] (Comparative Example 16) [Evaluation of Water Electrolysis of PiperION(OH)-A40] A water electrolysis cell was prepared using the same configuration as in Example 22 and PiperION(OH)-A40 as the anion exchange membrane. Water electrolysis was evaluated under the same test conditions as in Example X. Figure 45 and Table 15 show the electrolysis test results.

[0202]

[0203] As shown in Table 15, the PiperION(OH)(Tz2) composite film (4:1) exhibited a significantly lower cell voltage than the PiperION(OH)-A40 and Recast PiperION(OH) single films. This clearly supports the idea that, when the water content decreases due to dry cathode operation, the PiperION(OH)(Tz2) composite film (4:1), like the TMA(OH)-PF(Tz2) composite film, efficiently conducts electricity through anion-pi interactions. From these test results, it can be said that anion conduction using electron-deficient pi-conjugated molecular compounds exhibiting anion-pi interactions enables the achievement of excellent anion conductivity at low water content in anion exchange resins with various other anion exchange groups and polymer backbone structures.

[0204] (Synthesis Example 8) [Synthesis of dimethylimidazolylated polyfluorene (Dim(Br)-PF) having bromide ions as counterion species] Under a nitrogen atmosphere, 0.6031 g (0.66 mmol) of Br-PF synthesized in (Synthesis Example 1), 1.275 g (13 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) of 1,2-Dimethylimidazole and 10 mL (1.2 × 10) of tetrahydrofuran were used. ２mmol (manufactured by Kanto Chemical Co., Ltd.) was stirred at 70°C for 2 days to synthesize Dim(Br)-PF. The synthesized Dim(Br)-PF was recovered by precipitation purification in acetone. The Dim(Br)-PF was vacuum dried at 60°C for 6 hours to completely remove the solvent.

[0205] Next, the 1H NMR spectrum of Dim(Br)-PF was measured using a Bruker-500 FT / NMR spectrometer (manufactured by Bruker). Dimethylimidazolium group CH4 was detected at 4.03 ppm and 3.77 ppm. ３ Peaks originating from this were observed, indicating that the dimethylimidazolium reaction proceeded. The peak integration ratio around 8.0 ppm, which is unaffected by the dimethylimidazolium reaction, and the CH groups at 4.03 ppm and 3.77 ppm of the dimethylimidazolium group were observed. ３ From the integral ratio of the peaks derived from [the specified source], it became clear that two dimethylimidazolium groups are introduced per repeating unit. Figure 46 shows the chemical structure of Dim(Br)-PF.

[0206] [Preparation of Dim(Br)-PF single film] The previously obtained Dim(Br)-PF was dissolved in dimethyl sulfoxide at a concentration of approximately 3% by mass to prepare an anion exchange resin solution. This solution was poured onto a petri dish and left to stand at room temperature overnight or longer to allow the solvent to evaporate and form a film.

[0207] [Synthesis of Dimethylimidazolium-Polyfluorene (Dim(OH)-PF) Having Hydroxide Ions as Counterion Species] The Dim(Br)-PF film obtained in the previous example was immersed in a 1 M sodium hydroxide aqueous solution (prepared from Kanto Chemical Co., Ltd.) at room temperature for 12 hours to exchange the counterion species, thereby obtaining Dimethylimidazolium-Polyfluorene (Dim(OH)-PF) having hydroxide ions as counterions.

[0208] [Synthesis of Dimethylimidazolylated Polyfluorene (Dim(Cl)-PF) Having Chloride Ions as Counterion Species] The Dim(OH)-PF membrane obtained in the previous example was immersed in a 1 M aqueous solution of sodium chloride (prepared from Kanto Chemical Co., Ltd.) at room temperature for 12 hours to exchange the counterion species, thereby obtaining Dimethylimidazolylated Polyfluorene (Dim(Cl)-PF) having chloride ions as counterions.

[0209] [Synthesis of Dimethylimidazolylated Polyfluorene (Dim(I)-PF) Having Iodide Ions as Counterion Species] The Dim(OH)-PF film obtained in the previous example was immersed in a 1 M aqueous solution of potassium iodide (prepared from Kanto Chemical Co., Ltd.) at room temperature for 12 hours to exchange the counterion species, thereby obtaining Dimethylimidazolylated Polyfluorene (Dim(I)-PF) having iodide ions as counterions.

[0210] (Comparative Example 17) [Measurement of Anionic Conductivity of Dim(Br)-PF Single Film] The Dim(Br)-PF single film prepared in the previous example was subjected to anionic conductivity measurements at 90°C 90% RH, 90°C 60% RH, and 90°C 30% RH according to the method described in the formula for determining anionic conductivity. The anionic conductivity measurement results are summarized in Table 16.

[0211] [Preparation of Dim(Br)-PF(Tz2) composite film (4:1)] Dim(Br)-PF obtained in Synthesis Example 8 and Tz2 obtained in Synthesis Example 7 were mixed so that the molar ratio of dimethylimidazolium group to Tz was 4:1. This mixture was dissolved in dimethyl sulfoxide (manufactured by Kanto Chemical Co., Ltd.) to a solid content of approximately 3% by mass to obtain a homogeneous solution. The mixed solution was poured onto a petri dish, and the solvent was evaporated on a hot plate (Corning PC-420D) at 70°C to form a film.

[0212] (Example 23) [Measurement of Anionic Conductivity of Dim(Br)-PF(Tz2) Composite Film (4:1)] The anionic conductivity of the Dim(Br)-PF(Tz2) composite film (4:1) prepared in the previous example was measured at 90°C 90% RH, 90°C 60% RH, and 90°C 30% RH according to the formula for determining anionic conductivity described above. The results of the anionic conductivity measurement are summarized in Table 16.

[0213] [Preparation of Dim(I)-PF single film] The Dim(I)-PF obtained in synthesis example X was dissolved in dimethyl sulfoxide at a concentration of approximately 3% by mass to prepare an anion exchange resin solution. This solution was poured onto a petri dish and left to stand at room temperature overnight or longer to allow the solvent to evaporate and form a film.

[0214] (Comparative Example 18) [Measurement of Anionic Conductivity of Dim(I)-PF Single Film] The Dim(I)-PF single film prepared in the previous example was measured for anionic conductivity at 90°C 90% RH, 90°C 60% RH, and 90°C 30% RH according to the formula for determining anionic conductivity described above. The results of the anionic conductivity measurement are summarized in Table 16.

[0215] [Preparation of Dim(I)-PF(Tz2) composite film (4:1)] The Dim(I)-PF obtained in the previous example and the Tz2 obtained in the previous example were mixed so that the molar ratio of dimethylimidazolium groups to Tz was 4:1. This mixture was dissolved in dimethyl sulfoxide (manufactured by Kanto Chemical Co., Ltd.) to a solid content of approximately 3% by mass to obtain a homogeneous solution. The mixed solution was poured onto a petri dish, and the solvent was evaporated on a hot plate (Corning PC-420D) at 70°C to form a film.

[0216] (Example 24) [Measurement of Anionic Conductivity of Dim(I)-PF(Tz2) Composite Film (4:1)] The anionic conductivity of the Dim(I)-PF(Tz2) composite film (4:1) prepared in the previous example was measured at 90°C 90% RH, 90°C 60% RH, and 90°C 30% RH according to the method described in the paragraph above which the formula for determining anionic conductivity is described. The anionic conductivity measurement results are summarized in Table 16.

[0217]

[0218] As shown in Table 16, the Dim(I)-PF(Tz2) composite film exhibited superior anionic conductivity compared to the Dim(I)-PF single film in environments ranging from high to low humidity. Even the Dim(Br)-PF(Tz2) composite film, despite having a lower ion exchange capacity than the Dim(Br)-PF single film, showed comparable anionic conductivity at high humidity and superior conductivity at low humidity.

[0219] The results shown in Table 16 indicate that combining electron-deficient pi-conjugated molecule compounds that exhibit anion-pi interactions improves anion conductivity. In particular, I, which has been reported to exhibit strong anion-pi interactions, ― The usefulness of the present invention, which utilizes anion-pi interactions, was demonstrated by the fact that anion conductivity is significantly improved when the conductive anion is used, and even more so under low humidity conditions.

[0220] (Calculation Example 24) [HDim] As a model molecule for the dimethylimidazolium group, the structure of one molecule of hexyltodimethylimidazolium (HDim) was optimized under vacuum, and the total energy E (HDIM) was calculated. The results are shown in Table 17.

[0221] (Calculation Example 25) [HDim_Cl] One chloride ion was added to the hexyltodimethylimidazolium (HDim) optimized in Calculation Example 24, and structural optimization was performed under vacuum conditions the same as in Calculation Example 24. The total energy E (HDim_Cl) and the cation-anion distance were calculated. Multiple initial configurations of the chloride ion were tried to minimize the dependence on the initial configuration. The results are shown in Table 17.

[0222] (Calculation Example 26) [HDim_Cl_Tz2] The HDim_Cl optimized in Calculation Example 25 and the Tz2 optimized in Calculation Example 7 were arranged, and structural optimization was performed under vacuum conditions the same as in Calculation Example 25 to calculate the total energy E(HDim_Cl_Tz2) and the cation-anion distance. Multiple initial arrangements of Tz2 were tried to minimize dependence on the initial arrangement. As in the case of Calculation Example 25, the energy change (ΔE) with and without Tz2 was calculated. The results are shown in Table 17. When HDim_Cl and Tz2 are combined, the cation-anion distance expands compared to the case of HDim_Cl, and the energy change (ΔE) becomes more stable, indicating that anion-pi interaction occurs in HDim_Cl as well as in HTMA_Cl shown in Calculation Example 12. Similar effects were observed not only with ammonium but also with imidazolium, making it clear that the anion-pi interaction is effective in a wide range of ion combinations in this invention.

[0223]

[0224] Figures 47, 48, and 49 summarize the results of calculations similar to those described above, performed in the presence of water molecules. They serve as an indicator of the degree of interaction between molecules exhibiting anion-pi interactions when a particular molecule is placed at a specific position. In Figures 47, 48, and 49, a horizontal axis of 0 means there is no water, a horizontal axis of 1 means there is one water molecule, and a horizontal axis of 2 means there are two water molecules.

[0225] In the calculation results shown in Figures 47, 48, and 49, the calculated values ​​diverge vertically depending on the presence or absence of Tz when the number of water molecules is equal. The effect is weaker when there are many water molecules, but the fact that vertical divergence occurs even when there are few water molecules or when there are no water molecules indicates that the effect is significant. From these results, it can be inferred that the effect of mitigating the electrostatic interaction of anions is obtained by the influence of molecular compounds that exhibit anion-pi interactions.

[0226] [Preparation of Impregnated PiperION (Tz2) Composite Film] A PiperION-A40 film was immersed in a 0.1 M Tz2 acetonitrile solution at 60°C for 72 hours to obtain an impregnated PiperION (Tz2) composite film. The amount of Tz2 introduced was calculated from the weight change before and after impregnation, and the results are shown in Table 18.

[0227]

[0228] [Preparation of Impregnated PiperION(OH)(Tz2) Composite Film] The impregnated PiperION(Tz2) composite film was immersed in a 1 M sodium hydroxide aqueous solution (prepared from Kanto Chemical Co., Ltd.) at room temperature for 12 hours to exchange counterion species, thereby obtaining an impregnated PiperION(OH)(Tz2) composite film having hydroxide ions as counterions.

[0229] (Example 25) [Dry Alkali Stability Test of Impregnated PiperION(OH)(Tz2) Composite Film] The previously prepared impregnated PiperION(OH)(Tz2) composite film was left to stand under vacuum at room temperature for 48 hours. Before and after the test... １ 1H NMR measurements were performed. The ratio of the main chain protons to the protons derived from the piperidinium cation (Pip) after testing was calculated from the integral values, and the results are shown in Table 19.

[0230]

[0231] As shown in Table 19, the impregnated PiperION(OH)(Tz2) composite film had a higher amount of piperidinium cation (Pip) after testing compared to PiperION(OH)-A40, indicating improved stability due to the composite. Similar stability improvements were confirmed in Tz2 composite formation by impregnation, suggesting that the process of dissolving the anion exchange resin in a solvent can be omitted and that the material can be applied to crosslinked films that are insoluble in solvents.

[0232] The method for improving anionic conductivity according to the present invention provides a technology that enables the achievement of excellent anionic conductivity and chemical stability even in low-water content conditions by promoting the dissociation and diffusion of anions, which are conductive ion species, through the manifestation of anion-pi interactions within the anion exchange resin, and by improving alkaline stability due to the presence of bulky molecular compounds near the anion exchange group, thereby contributing to industrial development.

[0233] A, B...Water electrolysis device, 1...Positive electrode, 2...Negative electrode, 3...Anion exchange membrane, 5...Positive electrode side catalyst layer, 6...Negative electrode side catalyst layer, 7...Positive electrode side separator, 7a...Inlet, 7b...Outlet, 8...Negative electrode side separator, 8c...Outlet, 9...Power supply, 10...Supply tank, 11...Recovery tank, 12...Metal porous transport layer, 13...Positive electrode side separator, 17...Inlet, 18...Outlet, 19...Inlet, 20...Outlet.

Claims

1. A method for improving the anion conductivity of an anion exchange resin, characterized by combining an anion exchange resin having multiple ion exchange groups with an electron-deficient pi-conjugated molecule compound that exhibits anion-pi interactions, thereby promoting the dissociation and movement of anions in the anion exchange resin through anion-pi interactions.

2. A method for improving the anion conductivity of an anion exchange resin according to claim 1, characterized in that, in the presence of electrostatic interactions exhibited by the anion exchange resin, the electrostatic relaxation effect due to the anion-pi interaction exhibited by the electron-deficient pi-conjugated molecule compound stabilizes the anions on the surface of the anion exchange resin, while promoting the dissociation and movement of the anions and ion exchange groups in the anion exchange resin, thereby improving the anion conductivity.

3. As the anion, Cl － , Br － , I － , OH － , SO ４ － , PF ６ － [[ID=, 14]] NO ３ － , F － is used, the negative charge of the anion is relaxed by relaxing the electrostatic interaction on the surface of the anion exchange resin due to the anion-π interaction exhibited by the electron-deficient π-conjugated molecular compound, and the anion conductivity is improved by the dissociation of the anion and the ion exchange group on the surface of the anion exchange resin. A method for improving the anion conductivity of the anion exchange resin according to claim 1, characterized in that 4. A method for improving the anion conductivity of an anion exchange resin according to any one of claims 1 to 3, characterized in that a composite anion exchange resin is used which contains the anion exchange resin and the electron-deficient π-conjugated molecule compound in a molar ratio of 2:1 to 8:

1.

5. A method for improving anion conductivity in an anion exchange resin according to any one of claims 1 to 3, characterized in that the electron-deficient pi-conjugated molecule compound is a tetrazine derivative represented by the following formula (1).

6. A method for improving anion conductivity in an anion exchange resin according to any one of claims 1 to 3, characterized by using an anion exchange resin having a model molecule of an ion exchange group shown in the following formula (2).

7. A method for improving the anion conductivity of an anion exchange resin according to any one of claims 1 to 3, characterized by using the anion exchange resin shown in the following formula (3).

8. A method for improving anion conductivity in an anion exchange resin according to any one of claims 1 to 3, characterized in that the electron-deficient pi-conjugated molecule compound is a tetrazine derivative represented by the following formula (4).

9. A composite anion exchange resin characterized by having an anion exchange resin as a base material, and the base material being compounded with an electron-deficient π-conjugated molecule compound, exhibiting excellent anion conductivity and excellent alkali stability in low-water or anhydrous environments.

10. The composite anion exchange resin according to claim 9, characterized in that, in the presence of electrostatic interactions exhibited by the anion exchange resin constituting the base material, the electrostatic relaxation effect due to anion-pi interactions exhibited by the electron-deficient pi-conjugated molecule compound stabilizes anions on the surface of the base material and improves anion conductivity.

11. The anion is Cl － , Br － , I － , OH － SO ４ － , PF ６ － NO ３ － F － A composite anion exchange resin exhibiting excellent anion conductivity and excellent alkali stability in a low-water content environment or an anhydrous environment, characterized in that the negative charge of the anion is relaxed by the relaxation of the electrostatic interaction on the surface of the matrix material due to the anion-pi interaction exhibited by the electron-deficient pi-conjugated molecule compound, and the anion conductivity is improved by the dissociation of the anion and the ion exchange group on the surface of the matrix material, as described in 9.

12. The composite anion exchange resin according to any one of claims 9 to 11, characterized in that the electron-deficient pi-conjugated molecular compound is a molecular compound having a tetrazine skeleton in its main chain or side chain, exhibiting excellent anionic conductivity and excellent alkaline stability in a low-water content environment or an anhydrous environment.

13. A composite anion exchange resin that exhibits excellent anion conductivity and excellent alkali stability in a low-water content environment or an anhydrous environment, as described in any one of claims 9 to 11, characterized by containing the anion exchange resin and the electron-deficient π-conjugated molecule compound in a molar ratio of 2:1 to 8:

1.

14. A composite anion exchange resin exhibiting excellent anionic conductivity and excellent alkaline stability in a low-water content environment or an anhydrous environment, characterized in that the electron-deficient pi-conjugated molecule compound is a tetrazine derivative represented by the following formula (5), as described in any one of claims 9 to 11.

15. The composite anion exchange resin described in any one of claims 9 to 11, characterized in that the anion exchange resin has a model molecule of an ion exchange group shown in formula (6) below, exhibiting excellent anion conductivity and excellent alkali stability in a low-water content environment or an anhydrous environment.

16. A composite anion exchange resin exhibiting excellent anion conductivity and excellent alkali stability in a low-water-content environment or an anhydrous environment, as described in any one of claims 9 to 11, characterized in that the anion exchange resin is an anion exchange resin represented by the following formula (7).

17. A composite anion exchange resin exhibiting excellent anionic conductivity and excellent alkaline stability in a low-water content environment or an anhydrous environment, characterized in that the electron-deficient pi-conjugated molecule compound is a tetrazine derivative represented by the following formula (8), as described in any one of claims 9 to 11.

18. A water electrolysis apparatus characterized by comprising a composite anion exchange resin membrane, which is based on an anion exchange resin and compounded with an electron-deficient π-conjugated molecule compound; a gas-permeable anode electrode provided on one side of the composite anion exchange resin membrane; and a gas-permeable cathode electrode provided on the other side of the composite anion exchange resin membrane.

19. The water electrolysis apparatus according to claim 18, characterized in that, in the presence of electrostatic interactions exhibited by the anion exchange resin constituting the base material, the electrostatic relaxation effect due to the anion-pi interaction exhibited by the electron-deficient pi-conjugated molecule compound stabilizes the anions on the surface of the base material and improves anion conductivity.

20. The anion is Cl － , Br － , I － , OH － SO ４ － , PF ６ － NO ３ － F － The water electrolysis apparatus according to claim 18, wherein the negative charge of the anion is relaxed by the relaxation of the electrostatic interaction on the surface of the matrix material due to the anion-pi interaction exhibited by the electron-deficient pi-conjugated molecule compound, and the anion conductivity is improved by the dissociation of the anion and the ion exchange group on the surface of the matrix material.

21. The water electrolysis apparatus according to any one of claims 18 to 20, characterized in that the electron-deficient pi-conjugated molecular compound is a molecular compound having a tetrazine skeleton in its main chain or side chain.

22. The water electrolysis apparatus according to any one of claims 18 to 20, characterized in that the composite anion exchange resin membrane is a composite anion exchange resin membrane containing the anion exchange resin and the electron-deficient π-conjugated molecule compound in a molar ratio of 2:1 to 8:

1.

23. The water electrolysis apparatus according to any one of claims 18 to 20, characterized in that the electron-deficient pi-conjugated molecule compound is a tetrazine derivative represented by the following formula (9).

24. The water electrolysis apparatus according to any one of claims 18 to 20, characterized in that the anion exchange resin is an anion exchange resin having a model molecule of an ion exchange group shown in the following formula (10).

25. The water electrolysis apparatus according to any one of claims 18 to 20, characterized in that the anion exchange resin is an anion exchange resin represented by the following formula (11).

26. The water electrolysis apparatus according to any one of claims 18 to 20, characterized in that the electron-deficient pi-conjugated molecule compound is a tetrazine derivative represented by the following formula (12).

27. A method for producing a composite anion exchange resin membrane, characterized by: dissolving an anion exchange resin in a solvent to prepare an anion exchange resin solution; dissolving an electron-deficient pi-conjugated molecule compound in a solvent to prepare a molecular solution; mixing the anion exchange resin solution and the molecular solution to prepare a mixed solution; and heating and drying this mixed solution to produce a composite anion exchange resin membrane in which the anion exchange resin matrix and the electron-deficient pi-conjugated molecule compound are combined.

28. A method for producing a composite anion exchange resin film according to 27, characterized in that, in the presence of electrostatic interactions exhibited by the anion exchange resin constituting the base material, the electrostatic relaxation effect due to the anion-pi interaction exhibited by the electron-deficient pi-conjugated molecule compound stabilizes anions on the surface of the base material and improves anion conductivity.

29. The anion is Cl － , Br － , I － , OH － SO ４ － , PF ６ － NO ３ － F － A method for producing a composite anion exchange resin film according to claim 27, characterized in that the composite anion exchange film is one of the above, and the negative charge of the anion is relaxed by the relaxation of the electrostatic interaction on the surface of the matrix material due to the anion-pi interaction exhibited by the electron-deficient pi-conjugated molecule compound, and the anion conductivity is improved by the dissociation of the anion and the ion exchange group on the surface of the matrix material.

30. A method for producing a composite anion exchange resin membrane according to any one of claims 27 to 29, characterized in that a molecular compound having a tetrazine skeleton in its main chain or side chain is used as the electron-deficient pi-conjugated molecular compound.

31. A method for producing a composite anion exchange resin membrane according to any one of claims 27 to 29, characterized in that the composite anion exchange resin membrane contains the anion exchange resin and the electron-deficient π-conjugated molecule compound in a molar ratio of 2:1 to 8:

1.

32. A method for producing a composite anion exchange resin membrane according to any one of claims 27 to 29, characterized in that the electron-deficient pi-conjugated molecule compound is a tetrazine derivative represented by the following formula (13).

33. A method for producing a composite anion exchange resin membrane according to any one of claims 27 to 29, characterized in that the anion exchange resin is an anion exchange resin having a model molecule of an ion exchange group shown in the following formula (14).

34. A method for producing a composite anion exchange resin membrane, characterized by impregnating a membrane made of an anion exchange resin with a molecular solution in which an electron-deficient π-conjugated molecule compound is dissolved in a solvent, thereby producing a composite anion exchange resin membrane in which the anion exchange resin membrane and the electron-deficient π-conjugated molecule compound are combined.

35. A method for producing a composite anion exchange resin membrane according to any one of claims 27 to 29, characterized in that the anion exchange resin is an anion exchange resin represented by the following formula (15).

36. A method for producing a composite anion exchange resin membrane according to any one of claims 27 to 29, characterized in that the electron-deficient pi-conjugated molecule compound is a tetrazine derivative represented by the following formula (16).

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