Polymer electrolyte materials, polymer electrolyte molded bodies using the same, electrolyte membranes with catalyst layers, membrane electrode assemblies, solid polymer fuel cells, and water electrolysis hydrogen generators.

Abstract

Provided is a polymer electrolyte material which comprises a block copolymer having both of a segment having an ionic group (which is also referred to as an "ionic segment", hereinafter) and a segment containing no ionic group (which is also referred to as a "non-ionic segment", hereinafter), in which the polymer electrolyte material has a phase-separated structure and satisfies at least one of requirement 1 and requirement 2. <Requirement 1> The saturated crystallization degree of the polymer electrolytic material which is measured by wide-angle X-ray diffraction is 5% to 30% inclusive. <Requirement 2> The ion exchange capacity (IEC) of the polymer electrolyte material is 1.8 meq / g to 3.0 meq / g inclusive, and the product of the IEC (meq / g) of the polymer electrolyte material and the quantity of heat of crystallization (J / g) of the polymer electrolyte material which is measured by a differential scanning calorimetric method is 35.0 to 47.0 inclusive.　A polymer electrolyte material is provided, which has satisfactory mechanical durability and excellent proton conductivity.

Description

[Technical Field]

[0001] The present invention relates to polymer electrolyte materials, polymer electrolyte molded bodies using the same, electrolyte membranes with catalyst layers, membrane electrode assemblies, solid polymer fuel cells, and water electrolysis type hydrogen generators. [Background technology]

[0002] Fuel cells are a type of power generation device that extracts electrical energy by electrochemically oxidizing fuels such as hydrogen and methanol, and have recently attracted attention as a clean energy source. Among them, polymer electrolyte fuel cells have a low standard operating temperature of around 100°C and high energy density, making them promising for a wide range of applications as power generation devices in relatively small-scale distributed power generation facilities and in mobile devices such as automobiles and ships. Polymer electrolyte fuel cells are also attracting attention as a power source for small mobile devices and portable devices, and are expected to be used as a replacement for secondary batteries such as nickel-metal hydride batteries and lithium-ion batteries in mobile phones and personal computers.

[0003] Fuel cells typically consist of cells, each containing a membrane electrode assembly (MEA) sandwiched between separators. An MEA has catalyst layers on both sides of an electrolyte membrane, with gas diffusion layers further positioned on either side of the catalyst layers. In an MEA, the catalyst layers and gas diffusion layers on either side of the electrolyte membrane form a pair of electrode layers, one of which is the anode electrode and the other the cathode electrode. Electricity is generated through an electrochemical reaction when a hydrogen-containing fuel gas contacts the anode electrode and air contacts the cathode electrode. The electrolyte membrane is primarily composed of polymer electrolyte material. Polymer electrolyte material is also used as a binder for the catalyst layer.

[0004] Conventionally, "Nafion" (registered trademark) (manufactured by Chemours Co., Ltd.), a fluorine-based polymer electrolyte, has been widely used as a polymer electrolyte material. On the other hand, in recent years, the development of hydrocarbon-based electrolyte materials that can replace "Nafion" (registered trademark), are inexpensive, and have excellent membrane properties has also been actively pursued. Hydrocarbon-based electrolyte materials are excellent in low gas permeability and heat resistance, and electrolyte materials using aromatic polyether ketone and aromatic polyether sulfone have been particularly actively studied. However, conventional hydrocarbon-based electrolyte materials have insufficient proton conductivity while showing proton conductivity equivalent to or more excellent than that of fluorine-based electrolyte materials under high humidification conditions.

[0005] In response to the above problems, an electrolyte membrane having a phase separation structure has been proposed as a hydrocarbon-based polymer electrolyte membrane with improved proton conductivity and mechanical durability (see, for example, Patent Documents 1 and 2).

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] The polymer electrolyte membranes disclosed in the above patent documents can be expected to have improved proton conductivity and mechanical durability.

[0008] However, proton conductivity and mechanical durability generally have a trade-off relationship, that is, increasing proton conductivity reduces mechanical durability, and conversely, increasing mechanical durability reduces proton conductivity. There is still a problem that it is difficult to achieve both of these characteristics at a relatively high level even when using the electrolyte membranes described in Patent Documents 1 to 2.

[0009] Therefore, in view of the background of the prior art, the present invention aims to provide a polymer electrolyte material that achieves a relatively high level of both proton conductivity and mechanical durability. [Means for solving the problem]

[0010] The polymer electrolyte material of the present invention adopts the following configuration in order to solve the above problems. That is, A polymer electrolyte material comprising a block copolymer having segments containing ionic groups and segments not containing ionic groups, wherein the polymer electrolyte material has a phase separation structure. When the number-average molecular weight of the ionic segment is Mn1 and the number-average molecular weight of the nonionic segment is Mn2, if Mn2 is 15,000 or more, then the following equation 1 is satisfied, Furthermore, it is a polymer electrolyte material that satisfies at least one of the following conditions 1 and 2. 1.7≦Mn1 / Mn2≦7.0 (Formula 1) <Condition 1> The saturation crystallinity of the polymer electrolyte material, as measured by wide-angle X-ray diffraction, is 5% or more and 30% or less. <Condition 2> The ion exchange capacity (IEC) of the polymer electrolyte material is 1.8 meq / g or more and 3.0 meq / g or less, and the product of the IEC (meq / g) of the polymer electrolyte material and the crystallization heat (J / g) of the polymer electrolyte material measured by differential scanning calorimetry is 35.0 or more and 47.0 or less.

[0011] To solve the above problems, the polymer electrolyte molded body of the present invention adopts the following configuration. That is, This is a polymer electrolyte molded body containing the above-mentioned polymer electrolyte material.

[0012] The catalyst-layered electrolyte membrane of the present invention adopts the following configuration to solve the above problems. That is, This is an electrolyte membrane with a catalyst layer, constructed using the above-mentioned polymer electrolyte molded body.

[0013] To solve the above problems, the membrane electrode assembly of the present invention adopts the following configuration: that is, a membrane electrode assembly constructed using the above polymer electrolyte molded body.

[0014] The solid polymer fuel cell of the present invention adopts the following configuration in order to solve the above problems. That is, it is a solid polymer fuel cell constructed using the above polymer electrolyte molded body.

[0015] In the present invention, it is preferable that the polymer electrolyte material has a co-continuous or lamellar phase separation structure.

[0016] The polymer electrolyte material of the present invention preferably has an average period size of 15 to 100 nm in the phase separation structure.

[0017] In the polymer electrolyte material of the present invention, it is preferable that the block copolymer is an aromatic polyether copolymer.

[0018] In the polymer electrolyte material of the present invention, it is preferable that the block copolymer is an aromatic polyether ketone copolymer.

[0019] In the polymer electrolyte material of the present invention, it is preferable that the block copolymer has linker portions that bond between the ionic segment and the nonionic segment.

[0020] In the polymer electrolyte material of the present invention, it is preferable that the nonionic segment contains a structure represented by the following general formula (S3).

[0021] [ka]

[0022] (In general formula (S3), Ar 5 ~Ar 8 Each of these independently represents a substituted or unsubstituted arylene group. However, Ar 5 ~Ar 8 None of them have ionic groups. 3 and Y 4The symbols (*) independently represent a ketone group and a protecting group that can be converted to a ketone group. The asterisk (*) represents a bond with the general formula (S3) or other constituent units. In the polymer electrolyte material of the present invention, it is preferable that the structure represented by the general formula (S3) is the structure represented by the following general formula (S4).

[0023] [ka]

[0024] (In general formula (S4), Y 3 and Y 4 Each of these independently represents a ketone group or a protecting group that can be converted to a ketone group. * represents a bond with the general formula (S4) or other constituent units.

[0025] In the present invention, the polymer electrolyte material preferably has a number-average molecular weight of 15,000 or more for the nonionic segment. [Effects of the Invention]

[0026] According to the present invention, it is possible to provide a polymer electrolyte material that achieves a relatively high level of both proton conductivity and mechanical durability. [Brief explanation of the drawing]

[0027] [Figure 1] Figure 1 is a schematic diagram of the phase separation structure in a polymer electrolyte material. [Modes for carrying out the invention]

[0028] The embodiments of the present invention will be described in detail below, but the present invention is not limited to the embodiments described below and can be implemented with various modifications depending on the purpose and application.

[0029] The polymer electrolyte material of the present invention consists of a block copolymer having segments containing ionic groups (hereinafter referred to as "ionic segments") and segments not containing ionic groups (hereinafter referred to as "nonionic segments"). A polymer electrolyte material made of such a block polymer has the advantage of readily forming a phase-separated structure. Hereinafter, the polymer electrolyte material may simply be referred to as "electrolyte material".

[0030] The electrolyte material of the present invention has a phase separation structure and satisfies at least one of the following conditions 1 and 2. Such an electrolyte material has performance that balances mechanical durability and proton conductivity at a relatively high level. <Condition 1> The saturation crystallinity of the polymer electrolyte material, as measured by wide-angle X-ray diffraction, is between 5% and 30%. <Condition 2> The ion exchange capacity (IEC) of the polymer electrolyte material is 1.8 meq / g or more and 3.0 meq / g or less, and the product of the IEC (meq / g) of the polymer electrolyte material and the heat of crystallization of the polymer electrolyte material (J / g) measured by differential scanning calorimetry is 35.0 or more and 47.0 or less.

[0031] Hereinafter, the saturation crystallinity of polymer electrolyte materials measured by wide-angle X-ray diffraction will be abbreviated as "saturation crystallinity," the ion exchange capacity as "IEC," and the heat of crystallization measured by differential scanning calorimetry as "heat of crystallization."

[0032] In this invention, achieving a relatively high level of both mechanical durability and proton conductivity specifically means having relatively good mechanical durability and excellent proton conductivity, or having relatively good proton conductivity and excellent mechanical durability.

[0033] In this invention, good mechanical durability means that the dimensional change rate of the electrolyte membrane, which is made of electrolyte material, is small. Here, the dimensional change rate of the electrolyte membrane can be determined by the following measurement: A wet-dry cycle is repeatedly performed in which an electrolyte membrane test piece is subjected to a constant stress and alternately exposed to a dry atmosphere (30% RH) and a humidified atmosphere (90% RH). The dimensional change rate (%) at 30% RH and 90% RH after 10 cycles is measured, and the difference is taken as the wet-dry dimensional change rate (%).

[0034] In this invention, the phase separation structure of the electrolyte material, the degree of saturation crystallinity and heat of crystallization of the electrolyte material, and the mechanical durability (dry and wet dimensional change rate) and proton conductivity of the electrolyte material are all performed using a film (hereinafter referred to as "electrolyte film") obtained by coating a solution of the electrolyte material dissolved or dispersed in a suitable solvent onto a support substrate and drying it. Hereafter, the electrolyte material may be replaced with the electrolyte film in the explanation.

[0035] [Phase separation structure] The electrolyte material of the present invention has a phase separation structure. Here, the statement that the electrolyte material has a phase separation structure means that the phase separation structure can be confirmed when the electrolyte membrane is observed with a transmission electron microscope (TEM).

[0036] Figure 1 shows examples of the morphology of the phase separation structure of an electrolyte membrane. Phase separation structures are broadly classified into four types: co-continuous (M1), lamellar (M2), cylindrical (M3), and sea-island (M4). The electrolyte material of the present invention has one of the phase separation structures (M1) to (M4).

[0037] In Figure 1 (M1) to (M4), the continuous phase (Phase 1) in the white area is formed by one segment selected from the ionic segment and the nonionic segment, and the continuous or dispersed phase (Phase 2) in the gray area is formed by the other segment.

[0038] The above phase separation structure is described, for example, in the Annual Review of Physical Chemistry, 41, 1990, p. 525.

[0039] By controlling the higher-order structure and shape of the ionic and nonionic segments, excellent proton conductivity can be achieved even under low humidity and low temperature conditions. Specifically, the electrolyte membrane having a phase separation structure of (M1) to (M4) enables the formation of continuous proton conduction channels, thereby improving proton conductivity.

[0040] In a phase separation structure consisting of co-continuous (M1) and lamellar (M2) phases, both ionic and nonionic segments form a continuous phase. Electrolyte membranes having such a phase separation structure exhibit excellent proton conductivity due to the formation of continuous proton conduction channels, and simultaneously possess excellent mechanical durability due to the crystallinity of the domains consisting of nonionic segments. In other words, the electrolyte material of the present invention preferably has a co-continuous (M1) or lamellar (M2) phase separation structure, and preferably a co-continuous (M1) phase separation structure.

[0041] The domains mentioned above refer to aggregates of similar segments within one or more polymer chains.

[0042] The presence of a co-continuous (M1) or lamellar (M2) phase separation structure in an electrolyte membrane can be confirmed by the following method. Specifically, the presence of this structure is defined as occurring when the desired image is observed using the following method. This method involves comparing three digital slice views, cut from the length, width, and height directions, of a three-dimensional image obtained by TEM tomography observation. For example, in an electrolyte membrane containing a block copolymer having ionic and nonionic segments, if the phase separation structure is co-continuous (M1) or lamellar (M2), then in all three views, the hydrophilic domain containing the ionic segment and the hydrophobic domain containing the nonionic segment will both form a continuous phase.

[0043] In the case of cocontinuous (M1) patterns, each continuous phase exhibits an intricate design, while in the case of lamellar (M2) patterns, each continuous phase exhibits a layered design. Here, a continuous phase refers to a phase in which, macroscopically, individual domains are connected rather than isolated, although some unconnected parts are acceptable.

[0044] On the other hand, in the case of a cylindrical structure (M3) or a sea-island structure (M4), at least one of the domains does not form a continuous phase, so it can be distinguished from the co-continuous (M1) and lamellar (M2) structures, and the structure can also be identified from the patterns shown in each of the three views.

[0045] In observing the phase separation structure, to clarify the aggregation state and contrast of ionic and nonionic segments, for example, the electrolyte membrane can be immersed in a 2 wt% lead acetate aqueous solution for two days to exchange the ionic groups with lead, and then subjected to transmission electron microscopy (TEM) and TEM tomography observation.

[0046] The size of a phase-separated structure can be expressed as the periodic size of the hydrophilic domain containing the ionic segment and the hydrophobic domain containing the nonionic segment. This periodic size of the phase-separated structure can be estimated from the autocorrelation function obtained by image processing of the phase-separated structure, which is acquired through transmission electron microscopy (TEM) observation.

[0047] From the viewpoint of proton conductivity and mechanical durability, the average period size of the above phase separation structure is preferably in the range of 15 to 100 nm, more preferably in the range of 35 to 80 nm, even more preferably in the range of 40 to 67 nm, and particularly preferably in the range of 48 to 67 nm. Furthermore, if the average period size of the phase separation structure becomes larger than 100 nm, it becomes difficult to form a co-continuous-like phase separation structure. Therefore, from the viewpoint of obtaining a co-continuous-like phase separation structure, the average period size is preferably within the above range.

[0048] [Electrolyte material according to the first embodiment] The electrolyte material according to the first embodiment of the present invention (hereinafter referred to as "electrolyte material (I)") satisfies condition 1. That is, electrolyte material (I) has a saturation crystallinity of 5% or more and 30% or less.

[0049] (saturated crystallinity) Saturated crystallinity refers to the degree of crystallinity at which crystallinity can no longer proceed, i.e., the maximum degree of crystallinity. Specifically, an electrolyte membrane made of the aforementioned electrolyte material is heated and pressed at 4.5 MPa at a temperature above the glass transition temperature (Tg) of the electrolyte material, and the degree of crystallinity is measured by wide-angle X-ray diffraction every 5 minutes. The degree of crystallinity at which the degree of crystallinity stops changing is defined as the saturated crystallinity. The heating temperature (T (°C)) during heating and pressing should be in the range of Tg ≤ T ≤ Tg + 40°C. Specifically, Tg + 5°C is appropriate.

[0050] From the viewpoint of improving mechanical durability, the saturation crystallinity of the electrolyte material (I) is preferably 7% or more, more preferably 9% or more, and particularly preferably 10% or more. On the other hand, if the saturation crystallinity of the electrolyte material (I) exceeds 30%, the proton conductivity and processability decrease. From the viewpoint of proton conductivity and processability, the above saturation crystallinity is preferably 25% or less, more preferably 23% or less, even more preferably 20% or less, and particularly preferably 17% or less.

[0051] When electrolyte materials are applied to electrochemical applications such as polymer electrolyte fuel cells and water electrolysis hydrogen generators, they are generally processed into electrolyte molded membranes as described below. While the crystallinity of an electrolyte molded membrane using electrolyte material (I) can reach the saturation crystallinity described above, it is not always necessary to reach the saturation crystallinity.

[0052] An electrolyte-molded film using electrolyte material (I), specifically an electrolyte-molded film made from an electrolyte material consisting of a block copolymer having ionic and nonionic segments, exhibits good mechanical durability and excellent proton conductivity even if its crystallinity does not reach the saturation crystallinity of the electrolyte material. For example, it was confirmed that the electrolyte-molded film exhibits good mechanical durability and excellent proton conductivity even when crystallinity has hardly progressed.

[0053] The crystallinity of an electrolyte-molded film using electrolyte material (I) can be increased by heating it to a temperature above the glass transition temperature of electrolyte material (I). This further improves the proton conductivity and mechanical durability of the electrolyte-molded film. In this case, the crystallinity of the electrolyte-molded film may be increased to the same level as the saturation crystallinity of electrolyte material (I), or it may be increased to approximately 1-99% of the saturation crystallinity of electrolyte material (I). A method for adjusting the crystallinity of the electrolyte-molded film will be described later.

[0054] The IEC of electrolyte material (I) is not particularly limited, but is preferably 1.5 meq / g or more, more preferably 1.8 meq / g or more, even more preferably 1.9 meq / g or more, and particularly preferably 2.0 meq / g or more. Furthermore, the IEC of electrolyte material (I) is preferably 3.5 meq / g or less, more preferably 3.0 meq / g or less, even more preferably 2.9 meq / g or less, and particularly preferably 2.8 meq / g or less.

[0055] IEC refers to the molar amount of ion exchange groups introduced per unit dry mass of an electrolyte material (block copolymer). IEC can be measured by elemental analysis, neutralization titration, etc. When the ion exchange group is a sulfonic acid group, it can also be calculated from the S / C ratio using elemental analysis, but measurement is difficult when sulfur sources other than sulfonic acid groups are present. Therefore, in this invention, IEC is defined as the value obtained by the neutralization titration method described later.

[0056] [Electrolyte material according to the second embodiment] The electrolyte material according to the second embodiment of the present invention (hereinafter referred to as "electrolyte material (II)") satisfies condition 2. That is, the electrolyte material (II) has an IEC of 1.8 meq / g or more and 3.0 meq / g or less, and the product of the IEC and the heat of crystallization is 35.0 or more and 47.0 or less.

[0057] (IEC) The electrolyte material (II) has an IEC of 1.8 meq / g or more and 3.0 meq / g or less. Electrolyte material (II) with an IEC in the above range exhibits excellent proton conductivity. From the viewpoint of enhancing proton conductivity, the IEC of electrolyte material (II) is preferably 1.9 meq / g or more, more preferably 2.0 meq / g or more, even more preferably 2.1 meq / g or more, and particularly preferably 2.2 meq / g or more. Furthermore, from the viewpoint of ensuring high mechanical durability, the IEC is preferably 2.9 meq / g or less, more preferably 2.8 meq / g or less, and particularly preferably 2.6 meq / g or less.

[0058] (crystallization heat) Electrolyte material (II) is crystalline. Here, "crystalline" means that it has the property of crystallizing when heated. The degree of crystallinity can be expressed as the heat of crystallization measured by differential scanning calorimetry (DSC). One indicator of whether an electrolyte material is crystalline is that its heat of crystallization is 0.1 J / g or higher.

[0059] The following analytical methods can be used as differential scanning calorimetry (DSC) in this invention.

[0060] After pre-drying 10 mg of the sample (electrolyte membrane) in a DSC instrument at 110°C for 3 hours, the sample is heated to 200°C under the following conditions without removing it from the DSC instrument, and temperature-modulated differential scanning calorimetry is performed during the heating stage. Here, the electrolyte membrane obtained by coating a solution of the electrolyte material dissolved or dispersed in a suitable solvent onto a support substrate and drying it is used as the sample. • Measurement temperature range: 30℃ to 200℃ • Temperature control: AC temperature control • Heating rate: 2°C / min ·Amplitude: ±3℃ ·Applied frequency: 0.02Hz • Sample pan: Aluminum crimped pan • Measurement and pre-drying atmosphere: 100 mL / min nitrogen.

[0061] The differential scanning calorimetry (DSC) method described above has the advantage of not exposing the sample to the atmosphere (air) from pre-drying to measurement, compared to conventional analytical methods, as the sample is less affected by moisture in the atmosphere, thereby improving measurement accuracy.

[0062] (Product of IEC and heat of crystallization) Electrolyte material (II) has a product of its IEC (meq / g) and crystallization heat (J / g) of 35.0 to 47.0.

[0063] As mentioned earlier, proton conductivity and mechanical durability generally have a trade-off relationship. However, in the region where the IEC is between 1.8 meqJ / g and 3.0 meq / g, if the product of the IEC and the heat of crystallization is between 35.0 and 47.0, it is possible to achieve a relatively high level of both proton conductivity and mechanical durability.

[0064] As mentioned above, in electrolyte membranes, there is generally a trade-off relationship between proton conductivity and mechanical durability. Furthermore, there is a general correlation between proton conductivity and IEC, and between mechanical durability and crystallization heat. That is, IEC and crystallization heat have characteristics with vectors moving in opposite directions. The inventors have found that the physical quantity obtained by multiplying IEC and crystallization heat is effective as an indicator for achieving both proton conductivity and mechanical durability, and that in the region where IEC is between 1.8 meq / g and 3.0 meq / g, the physical quantity obtained by multiplying IEC and crystallization heat is particularly effective, and that when the range of this physical quantity is between 35.0 and 47.0, it is possible to achieve a relatively high level of balance between proton conductivity and mechanical durability.

[0065] From the above viewpoint, the product of IEC and the heat of crystallization is preferably 36.0 or more and 47.0 or less, and more preferably 37.0 or more and 44.0 or less.

[0066] The heat of crystallization of the electrolyte material (II) is designed so that the product of the IEC and the heat of crystallization falls within the above range. Specifically, the heat of crystallization is preferably 12.0 J / g or more, more preferably 13.0 J / g or more, and particularly preferably 14.0 J / g or more. Furthermore, the heat of crystallization of the electrolyte material (II) is preferably 25.0 J / g or less, more preferably 24.0 J / g or less, and particularly preferably 23.0 J / g or less. If the heat of crystallization exceeds the above range, the electrolyte membrane tends to become brittle, while if the heat of crystallization falls below the above range, the mechanical durability tends to decrease.

[0067] The IEC of electrolyte material (II) can be adjusted, for example, by controlling the density of sulfonic acid groups in the block copolymer and the content of ionic segments in the block copolymer. The heat of crystallization of electrolyte material (II) can be adjusted, for example, by controlling the structure of nonionic segments, the molecular weight of nonionic segments, and the content of nonionic segments in the block copolymer. Further details will be described later.

[0068] The following describes matters common to the electrolyte materials of the present invention, including the electrolyte material according to the first embodiment and the electrolyte material according to the second embodiment described above. In the following description, when "electrolyte material of the present invention" is used, it naturally includes electrolyte material (I) and electrolyte material (II).

[0069] [Block copolymer] The electrolyte material of the present invention consists of a block copolymer having an ionic segment and a nonionic segment. In the present invention, a segment is a partial structure within the block copolymer of a macromonomer used in the synthesis of the block copolymer. Although the nonionic segment is described as not containing ionic groups, it may contain a small amount of ionic groups as long as it does not adversely affect the effects of the present invention, particularly its crystallinity.

[0070] The block copolymer constituting the polymer electrolyte material of the present invention is formed by linking two or more mutually immiscible segment chains, namely hydrophilic ionic segments and hydrophobic nonionic segments, to form a single polymer chain. In the block copolymer, short-range interactions arising from repulsion between chemically different segment chains cause phase separation into nano or microdomains composed of each segment chain. Then, because the segment chains are covalently bonded to each other, long-range interactions occur, and as a result, each domain is arranged in a specific order. The higher-order structure created by the aggregation of domains composed of each segment chain is called a nano or microphase separation structure. Here, a domain refers to a cluster formed by the aggregation of similar segments in one or more polymer chains. For ion conduction in electrolyte membranes, the spatial arrangement of ion-conducting segments in the membrane, i.e., the nano or microphase separation structure, is important.

[0071] [Ionic segment] The ionic segments in the block copolymer constituting the polymer electrolyte material of the present invention are preferably hydrocarbon polymers from the viewpoint of crystallinity and mechanical durability. Here, hydrocarbon polymer means a polymer other than a perfluoro polymer, and hydrocarbon polymer means a polymer other than a perfluoro polymer.

[0072] Furthermore, from the viewpoint of crystallinity and mechanical durability, the ionic segment is preferably a hydrocarbon polymer having an aromatic ring in the main chain (hereinafter referred to as "aromatic hydrocarbon polymer").

[0073] The aromatic rings in aromatic hydrocarbon polymers may include not only hydrocarbon aromatic rings but also heterocycles. Furthermore, some aliphatic units may constitute the polymer along with the aromatic ring units. Specific examples of aromatic hydrocarbon polymers include polymers having structures selected from polysulfone, polyethersulfone, polyphenylene oxide, polyarylene ether polymers, polyphenylene sulfide, polyphenylene sulfide sulfone, polyparaphenylene, polyarylene polymers, polyarylene ketone, polyether ketone, polyarylene phosphine foxide, polyetherphosphine foxide, polybenzoxazole, polybenzothiazole, polybenzimidazole, polyamide, polyimide, polyetherimide, and polyimide sulfone in the main chain along with aromatic rings. Among these, aromatic polyether polymers are preferred from the viewpoint of cost and polymerizability.

[0074] Aromatic polyether polymers are polymers mainly composed of aromatic rings in which at least ether bonds are included in the manner in which the aromatic ring units are linked within the repeating units. Examples of aromatic polyether polymer structures include, but are not limited to, aromatic polyethers, aromatic polyether ketones, aromatic polyetherimides, and aromatic polyethersulfones. From the viewpoint of chemical stability and cost, aromatic polyether ketone polymers and aromatic polyethersulfone polymers are preferred, and from the viewpoint of mechanical and physical durability, aromatic polyether ketone polymers are most preferred.

[0075] Aromatic polyetherketone polymers are polymers primarily composed of aromatic rings in which at least ether and ketone bonds are included in the manner in which the aromatic ring units are linked within the repeating unit. Aromatic polyetherketone polymers include aromatic polyetherketones, aromatic polyether ether ketones, aromatic polyether ketone ketones, aromatic polyether ether ketone ketones, aromatic polyether ketone ether ketone ketones, and aromatic polyether ketone ether ketone ketones.

[0076] Aromatic polyethersulfone polymers are polymers mainly composed of aromatic rings in which at least ether bonds and sulfone bonds are included in the manner in which the aromatic ring units are linked within the repeating unit.

[0077] The ionic segments used in this invention can be synthesized by aromatic nucleophilic substitution reactions, coupling reactions, and the like.

[0078] The ionic segment is preferably an aromatic polyether polymer, as described above, and the aromatic polyether polymer preferably contains a structure represented by the following general formula (S1).

[0079] [ka]

[0080] In the general formula (S1), Ar 1 ~Ar 4 each independently represents a substituted or unsubstituted arylene group, and at least one of Ar 1 ~Ar 4 has an ionic group. Y 1 and Y 2 each independently represents a ketone group or a protecting group that can be derived from a ketone group. * represents a bond with the general formula (S1) or other structural units.

[0081] Here, examples of the arylene group represented by Ar 1 ~Ar 4 include hydrocarbon-based arylene groups such as phenylene group, naphthylene group, biphenylene group, fluorenediyl group, and heteroarylene groups such as pyridinediyl, quinoxalinediyl, thiophenediyl, etc., but are not limited thereto. The ionic group preferably has an atomic group with a negative charge and a proton exchange ability. Examples of such functional groups include sulfonic acid group, sulfonimide group, sulfuric acid group, phosphonic acid group, phosphoric acid group, carboxylic acid group, but are not limited thereto.

[0082] The above ionic group includes the case where it is in the form of a salt. Examples of the cation forming such a salt include any metal cation, NR4 + (R is any organic group), etc. There is no particular limitation on the metal cation, but Na, K, Li, which are inexpensive and easily proton-substitutable, are preferred.

[0083] These ionic groups can contain two or more types in the ionic segment, and the combination can be appropriately determined depending on the structure of the block copolymer, etc. Among them, it is more preferable to contain at least a sulfonic acid group, a sulfonimide group, and a sulfuric acid group from the viewpoint of high proton conductivity, and it is particularly preferable to contain a sulfonic acid group from the viewpoint of raw material cost.

[0084] Also, in the general formula (S1), Y 1 and Y2 From the viewpoint of forming a phase-separated structure, it is preferable that the protecting group is a ketone group or a protecting group that can be converted to a ketone group. That is, it is preferable that the ionic segment is an aromatic polyether ketone polymer. Protecting groups that can be converted to a ketone group will be described later.

[0085] From the viewpoint of raw material availability, it is preferable that the structure represented by the above general formula (S1) is the structure represented by the following general formula (P1), and among these, it is even more preferable from the viewpoint of raw material availability and polymerizability that the structure represented by the following general formula (S2) is.

[0086] [ka]

[0087] In general formula (P1) and general formula (S2), Y 1 and Y 2 Each of these independently represents a ketone group or a protecting group that can be converted to a ketone group. 1 ~M 4 Each of the following independently represents a hydrogen atom, a metal cation, or an ammonium cation. Each of n1 to n4 is independently 0 or 1, and at least one of n1 to n4 is 1. * represents a bond with the general formula (P1), (S2) or other constituent units.

[0088] Furthermore, from the standpoint of raw material availability and polymerizability, it is most preferable that n1=1, n2=1, n3=0, n4=0 or n1=0, n2=0, n3=1, n4=1.

[0089] Examples of ionic monomers used to synthesize the constituent units of the ionic segments described above include aromatic active dihalide compounds. Using compounds obtained by introducing an ionic acid group into an aromatic active dihalide compound is preferable as the aromatic active dihalide compound used in the ionic segment due to its chemical stability, manufacturing cost, and the ability to precisely control the amount of ionic group. Suitable specific examples of monomers having a sulfonic acid group as an ionic group include, but are not limited to, 3,3'-disulfonate-4,4'-dichlorodiphenylsulfone, 3,3'-disulfonate-4,4'-difluorodiphenylsulfone, 3,3'-disulfonate-4,4'-dichlorodiphenylketone, 3,3'-disulfonate-4,4'-difluorodiphenylketone, 3,3'-disulfonate-4,4'-dichlorodiphenylphenylphosphine oxide, and 3,3'-disulfonate-4,4'-difluorodiphenylphenylphosphine oxide.

[0090] From the viewpoint of proton conductivity and hydrolysis resistance, a sulfonic acid group is the most preferred ionic group, but monomers having the above-mentioned ionic group may also have other ionic groups.

[0091] Among the monomers having sulfonic acid groups described above, 3,3'-disulfonate-4,4'-dichlorodiphenyl ketone and 3,3'-disulfonate-4,4'-difluorodiphenyl ketone are more preferred in terms of chemical stability and physical durability, and 3,3'-disulfonate-4,4'-difluorodiphenyl ketone is most preferred in terms of polymerization activity.

[0092] As monomers having ionic groups, ionic segments synthesized using 3,3'-disulfonate-4,4'-dichlorodiphenyl ketone and 3,3'-disulfonate-4,4'-difluorodiphenyl ketone contain the constituent units represented by the following general formula (p1) and are preferably used. These aromatic polyether polymers, in addition to the high crystallinity properties of ketone groups, are components with superior heat and water resistance compared to sulfone groups, and are therefore more preferably used as effective components for materials with excellent dimensional stability, mechanical strength, and physical durability under high temperature and high humidity conditions. When polymerizing these sulfonic acid groups, it is preferable that the sulfonic acid groups are salts with monovalent cation species. The monovalent cation species may be sodium, potassium, other metal species, or various amines, and is not limited to these. These aromatic active dihalide compounds can be used individually, but it is also possible to use multiple aromatic active dihalide compounds in combination.

[0093] [ka]

[0094] (In general formula (p1), M 1 and M 2 (where a1 and a2 represent integers from 1 to 4, where a1 represents hydrogen, a metal cation, or an ammonium cation.) Furthermore, the density of ionic groups in aromatic active dihalide compounds can be controlled by copolymerizing compounds with and without ionic groups. However, from the viewpoint of ensuring the continuity of the proton conduction path, it is more preferable not to copolymerize aromatic active dihalide compounds without ionic groups into the ionic segment.

[0095] More suitable examples of aromatic active dihalide compounds that do not have ionic groups include 4,4'-dichlorodiphenyl sulfone, 4,4'-difluorodiphenyl sulfone, 4,4'-dichlorodiphenyl ketone, 4,4'-difluorodiphenyl ketone, 4,4'-dichlorodiphenylphenylphosphine oxide, 4,4'-difluorodiphenylphenylphosphine oxide, 2,6-dichlorobenzonitrile, and 2,6-difluorobenzonitrile. Among these, 4,4'-dichlorodiphenyl ketone and 4,4'-difluorodiphenyl ketone are more preferred in terms of imparting crystallinity, mechanical strength, physical durability, and hot water resistance, while 4,4'-difluorodiphenyl ketone is most preferred in terms of polymerization activity. These aromatic active dihalide compounds can be used individually, but it is also possible to use multiple aromatic active dihalide compounds in combination.

[0096] A polymer electrolyte material synthesized using 4,4'-dichlorodiphenyl ketone and 4,4'-difluorodiphenyl ketone as aromatic active dihalide compounds further contains the constituent units represented by the following general formula (p2), and is preferably used. These constituent units serve as components that impart intermolecular cohesive force and crystallinity, resulting in a material with excellent dimensional stability, mechanical strength, and physical durability under high temperature and high humidity conditions, and is therefore preferably used.

[0097] [ka]

[0098] (The constituent units represented by general formula (p2) may be substituted as desired, but ionic groups are not included.) Furthermore, examples of nonionic monomers used to synthesize ionic segments include aromatic diphenol compounds, and it is particularly preferable that these are aromatic diphenol compounds having a protecting group, as described later.

[0099] The monomers used to synthesize the constituent units of ionic segments have been described above.

[0100] As an ionic segment, or as a constituent unit of an ionic segment, structures represented by the following general formulas (T1) and (T2) may be included in addition to the structure represented by general formula (S1).

[0101] [ka]

[0102] In general formulas (T1) and (T2), B represents a divalent organic group containing an aromatic ring. 5 and M 6 Each of these independently represents a hydrogen atom, a metal cation, or an ammonium cation.

[0103] In this aromatic polyether ketone copolymer, the ion exchange capacity can be controlled by changing the composition ratio of the constituent units represented by general formulas (T1) and (T2).

[0104] It is particularly preferable that the ionic segment has a structure represented by general formula (P1) and structures represented by general formulas (T1) and (T2). In such an ionic segment, when the amounts of the constituent units represented by general formulas (P1), (T1), and (T2) are p1, t1, and t2, respectively, it is preferable that p1 is 75 moles or more, more preferably 90 moles or more, and even more preferably 100 moles or more, per 100 moles of the total molar amount of t1 and t2.

[0105] Examples of divalent organic groups B containing aromatic rings in general formulas (T1) and (T2) include residues of various divalent phenol compounds that can be used in the polymerization of aromatic polyether polymers by aromatic nucleophilic substitution reactions, as well as those to which a sulfonic acid group has been introduced. Suitable examples of divalent organic group B containing an aromatic ring include, but are not limited to, the groups represented by the following general formulas (X'-1) to (X'-6).

[0106] [ka]

[0107] These may have ionic or aromatic groups. They can also be used in combination as needed. In particular, from the viewpoint of crystallinity, dimensional stability, toughness, and chemical stability, groups represented by general formulas (X'-1) to (X'-4) are more preferred, and most preferably are groups represented by general formulas (X'-2) and (X'-3).

[0108] [Nonionic segment] The nonionic segments constituting the block copolymer of the present invention are preferably hydrocarbon polymers, and more preferably aromatic hydrocarbon polymers, from the viewpoint of crystallinity and mechanical durability. Hereinafter, the definition of hydrocarbon polymers and specific examples of aromatic hydrocarbon polymers are as described above.

[0109] Among aromatic hydrocarbon polymers, aromatic polyether polymers are preferred from the viewpoint of cost and polymerizability, and aromatic polyether ketone polymers and aromatic polyether sulfone polymers are preferred from the viewpoint of mechanical durability and physical durability, with aromatic polyether ketone polymers being particularly preferred.

[0110] The nonionic segment is preferably an aromatic polyether polymer, as described above, and the aromatic polyether polymer preferably contains a structure represented by the following general formula (S3).

[0111] [ka]

[0112] In general formula (S3), Ar 5 ~Ar 8 Each of these independently represents a substituted or unsubstituted arylene group. However, Ar 5 ~Ar 8 None of them have ionic groups. 3and Y 4 The symbols * represent, independently, a ketone group and a protecting group that can be converted to a ketone group. The asterisk (*) represents a bond with the general formula (S3) or other constituent units.

[0113] Here, Ar 5 ~Ar 8 Examples of arylene groups represented by include, but are not limited to, hydrocarbon arylene groups such as phenylene groups, naphthylene groups, biphenylene groups, and fluoroorangeyl groups, and heteroarylene groups such as pyridinediyl, quinoxalinediyl, and thiophenediyl.

[0114] Furthermore, in the general formula (S3), Y 3 and Y 4 Since it is a ketone group or a protecting group that can be converted to a ketone group, from the viewpoint of forming a phase-separated structure, the block copolymer is crystalline and readily forms a phase-separated structure. In other words, the nonionic segment is preferably an aromatic polyether ketone polymer.

[0115] From the viewpoint of raw material availability, it is preferable that the structure represented by the above general formula (S3) contains the structure represented by the following general formula (P2), and in particular, it is even more preferable from the viewpoint of mechanical durability, dimensional stability, and physical durability due to crystallinity if it contains the constituent unit represented by the following general formula (S4).

[0116] [ka]

[0117] In general formulas (P2) and (S4), Y 3 and Y 4 Each of these independently represents a ketone group or a protecting group that can be converted to a ketone group. * represents a bond with general formulas (P2) and (S4) or other constituent units.

[0118] The content of the structure represented by the general formula (P2) or (S4) in the nonionic segment is preferably 20 mol% or more, more preferably 50 mol% or more, and particularly preferably 80 mol% or more, from the viewpoint of mechanical durability, dimensional stability, and physical durability.

[0119] Preferred protecting groups that can be converted to a ketone group include, for example, those containing at least one selected from the following general formulas (P3) and (P4).

[0120] [ka]

[0121] (In general formulas (P3) and (P4), Ar 11 ~Ar 14 R is any divalent arylene group. 1 and R 2 H is at least one group selected from alkyl groups, R 3 represents any alkylene group, each of which may represent two or more different groups. The groups represented by general formulas (P3) and (P4) may be substituted as desired. R in the general formula (P3) 1 and R 2 In terms of stability, alkyl groups are more preferable, even more preferably alkyl groups having 1 to 6 carbon atoms, and most preferably alkyl groups having 1 to 3 carbon atoms. Also, R in general formula (P4) 3 In terms of stability, an alkylene group having 1 to 7 carbon atoms is more preferable, and most preferably an alkylene group having 1 to 4 carbon atoms. 3 Specific examples include, but are not limited to, -CH2CH2-, -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -C(CH3)2CH(CH3)-, -C(CH3)2O(CH3)2-, -CH2CH2CH2-, -CH2C(CH3)2CH2-, etc.

[0122] Ar in the above general formulas (P3) and (P4) 11~Ar 14 Preferred organic groups are phenylene groups, naphthylene groups, or biphenylene groups. These may be optionally substituted. As for aromatic polyether polymers, due to their solubility and the ease of obtaining raw materials, Ar in the general formula (P4) is preferred. 13 and Ar 14 It is more preferable that both are phenylene groups, and most preferably Ar 13 and Ar 14 Both are p-phenylene groups.

[0123] One method for protecting the ketone moiety with a ketal involves reacting a precursor compound having a ketone group with a monofunctional and / or bifunctional alcohol in the presence of an acid catalyst. For example, it can be produced by reacting the ketone precursor 4,4'-dihydroxybenzophenone with a monofunctional and / or bifunctional alcohol in a solvent such as an aliphatic or aromatic hydrocarbon in the presence of an acid catalyst such as hydrogen bromide. The alcohol is an aliphatic alcohol having 1 to 20 carbon atoms.

[0124] An improved method for producing ketal monomers involves reacting a ketone precursor, 4,4'-dihydroxybenzophenone, with a difunctional alcohol in the presence of an alkyl orthoester and a solid catalyst.

[0125] The method for deprotecting at least a portion of the ketone moiety protected with ketal to create the ketone moiety is not particularly limited. The deprotection reaction can be carried out in the presence of water and acid under heterogeneous or homogeneous conditions, but from the viewpoint of mechanical strength, physical durability and solvent resistance, a method of acid treatment after forming into a film is more preferable. Specifically, deprotection can be carried out by immersing the formed film in an aqueous hydrochloric acid solution or an aqueous sulfuric acid solution, and the concentration of the acid and the temperature of the aqueous solution can be appropriately selected.

[0126] The required weight ratio of acidic aqueous solution to polymer is preferably 1 to 100 times, but even larger amounts of water can be used. The acid catalyst is preferably used at a concentration of 0.1 to 50% by weight of the present water. Suitable acid catalysts include strong mineral acids such as hydrochloric acid, nitric acid, fluorosulfonic acid, and sulfuric acid, and strong organic acids such as p-toluenesulfonic acid and trifluoromethanesulfonic acid. The amount of acid catalyst and excess water, reaction pressure, etc., can be appropriately selected depending on the polymer film thickness, etc.

[0127] For example, a film with a thickness of 50 μm can be almost completely deprotected by immersing it in an acidic aqueous solution, such as a 6N hydrochloric acid aqueous solution, and heating it at 95°C for 1 to 48 hours. Alternatively, immersion in a 1N hydrochloric acid aqueous solution at 25°C for 24 hours can also deprotect most of the protecting groups. However, the deprotection method is not limited to these methods; deprotection can also be performed using acidic gases, organic acids, or heat treatment.

[0128] Even when the aromatic polyether polymer includes bonding modes other than ether bonding, such as direct bonding, it is more preferable for the protective group to be introduced to be located in the aromatic ether polymer portion, from the viewpoint of improving processability.

[0129] Specifically, for example, aromatic polyether polymers containing the constituent units represented by the general formulas (P3) and (P4) can be synthesized by aromatic nucleophilic substitution reaction with aromatic active dihalide compounds, using compounds represented by the following general formulas (P3-1) and (P4-1) as aromatic diphenol compounds, respectively. The constituent units represented by the general formulas (P3) and (P4) may originate from either the aromatic diphenol compound or the aromatic active dihalide compound, but it is more preferable to use those derived from the aromatic diphenol compound, considering the reactivity of the monomer.

[0130] [ka]

[0131] (In general formulas (P3-1) and (P4-1), Ar 11 ~Ar 14 R is any divalent arylene group. 1 and R 2 H is at least one group selected from alkyl groups, R 3 represents any alkylene group. Compounds represented by general formulas (P3-1) and (P4-1) may be optionally substituted.) The preferred protecting groups have been described above.

[0132] [Detailed explanation of block copolymers] In the block copolymer constituting the polymer electrolyte material of the present invention, it is preferable that both the ionic and nonionic segments are aromatic polyether polymers, and more preferably aromatic polyether ketone polymers. In such a block copolymer, the IEC and heat of crystallization can be adjusted by controlling the molecular structure of each segment, the molecular weight of each segment, the molecular weight ratio of both segments, the density of sulfonic acid groups, and so on.

[0133] For example, the IEC of a block copolymer can be adjusted by controlling the density of sulfonic acid groups in the ionic segment and the content of the ionic segment in the block copolymer.

[0134] Furthermore, the degree of saturation crystallinity and heat of crystallization of the block copolymer can be adjusted, for example, by adjusting the molecular weight of the nonionic segment and the content of the nonionic segment in the block copolymer. Specifically, by setting the number-average molecular weight of the nonionic segment to 15,000 or more, the degree of saturation crystallinity and heat of crystallization of the block copolymer can be increased to a desired range. In other words, it is more preferable that the nonionic segment constituting the block copolymer in the present invention is an aromatic polyether ketone polymer with a number-average molecular weight of 15,000 or more. In particular, the block copolymer constituting the polymer electrolyte material of the present invention preferably includes an ionic segment containing a structural unit represented by the general formula (S1) and a nonionic segment containing a structural unit represented by the general formula (S3).

[0135] When a nonionic segment contains a constituent unit represented by the general formula (S3), it is a crystalline segment, and by controlling the molecular weight of this nonionic segment and its content in the block copolymer, the desired degree of saturated crystallinity and heat of crystallization can be adjusted.

[0136] A block copolymer containing a nonionic segment with a structural unit represented by general formula (S3) can be produced, for example, by molding a block copolymer precursor in which a protecting group has been introduced to at least the nonionic segment, and then deprotecting at least a portion of the protecting group contained in the molded article. Block copolymers tend to have poorer processability than random copolymers due to the crystallization of the polymer that forms domains; therefore, it is preferable to introduce a protecting group to at least the nonionic segment to improve processability, and it is also preferable to introduce a protecting group to the ionic segment if it results in poor processability.

[0137] The block copolymer constituting the polymer electrolyte material of the present invention has a phase-separated structure. That is, in the block copolymer of the present invention, which has ionic segments and nonionic segments, the hydrophilic domains formed by the aggregation of the ionic segments exhibit excellent proton conductivity due to their locally high concentration of ionic groups. The hydrophobic domains formed by the aggregation of the nonionic segments exhibit excellent dimensional stability due to their strong intermolecular interactions caused by their crystallinity.

[0138] The formation of a phase separation structure is facilitated when both the ionic and nonionic segments constituting the block copolymer are aromatic polyether polymers, preferably aromatic polyether ketone polymers. Furthermore, from the above viewpoint, it is preferable that the block copolymer in the present invention includes an ionic segment containing the constituent unit represented by the general formula (S1) and a nonionic segment containing the constituent unit represented by the general formula (S3).

[0139] Furthermore, the block copolymer constituting the polymer electrolyte material of the present invention preferably contains one or more linker moieties that connect the ionic segment and the nonionic segment, and such a block copolymer is more preferable because it readily forms a co-continuous or lamellar phase separation structure.

[0140] The linker described above is defined as a region that connects an ionic segment and a nonionic segment, and which has a different chemical structure from the ionic segment or the nonionic segment.

[0141] Linkers have the function of linking different segments while suppressing randomization of copolymers by ether exchange reactions, segment cleavage, and other side reactions that may occur during copolymer synthesis. Therefore, by using compounds that give such linkers as raw materials, block copolymers can be obtained without reducing the molecular weight of each segment. Examples of linkers include, but are not limited to, decafluorobiphenyl, hexafluorobenzene, 4,4'-difluorodiphenylsulfone, and 2,6-difluorobenzonitrile.

[0142] By controlling the number-average molecular weight of the ionic segments and non-ionic segments constituting the block copolymer constituting the polymer electrolyte material of the present invention, the IEC, saturation crystallinity, heat of crystallization, and average period size of the phase separation structure of the block copolymer can be adjusted to the desired ranges described above. For example, the number-average molecular weight of the ionic segments is preferably in the range of 10,000 to 150,000, more preferably in the range of 20,000 to 120,000, and particularly preferably in the range of 45,000 to 100,000, from the viewpoint of adjusting the IEC and average period size of the phase separation structure to the desired range. On the other hand, the number-average molecular weight of the non-ionic segments is preferably in the range of 5,000 to 50,000, more preferably in the range of 10,000 to 40,000, and particularly preferably in the range of 15,000 to 30,000, from the viewpoint of adjusting the saturation crystallinity, heat of crystallization, and average period size of the phase separation structure to the desired range.

[0143] To achieve a relatively high number-average molecular weight of the ionic segment, for example, to achieve a number-average molecular weight of 45,000 or more, it is preferable to link the constituent units within the ionic segment with linkers. The use of linkers facilitates the synthesis of long-chain polymers. Examples of linkers include, but are not limited to, decafluorobiphenyl, hexafluorobenzene, 4,4'-difluorodiphenylsulfone, and 2,6-difluorobenzonitrile.

[0144] Furthermore, in the block copolymer constituting the polymer electrolyte material of the present invention, when the number-average molecular weight of the ionic segment is Mn1 and the number-average molecular weight of the nonionic segment is Mn2, it is preferable that the following formula 1 is satisfied, and more preferably that the following formula 2 is satisfied. Such a block copolymer is preferable from the viewpoint of adjusting the IEC, heat of crystallization, and average period size of the phase separation structure to the aforementioned range.

[0145] 1.7≦Mn1 / Mn2≦7.0 (Formula 1) 2.0≦Mn1 / Mn2≦5.0 (Equation 2).

[0146] In particular, it is preferable that the number-average molecular weight (Mn2) of the nonionic segments is 15,000 or more and that the above equations 1 and 2 are satisfied, from the viewpoint of adjusting the IEC, saturated crystallinity, heat of crystallization, and average periodic size of the phase separation structure to the aforementioned range.

[0147] The following are examples of specific synthesis methods for the block copolymers constituting the polymer electrolyte material of the present invention. However, the present invention is not limited to these.

[0148] Each segment in the block copolymer constituting the polymer electrolyte material of the present invention is preferably synthesized by an aromatic nucleophilic substitution reaction, as this is process-wise easy. The aromatic nucleophilic substitution reaction is a method of reacting a monomer mixture of a dihalide compound and a diol compound in the presence of a basic compound. Polymerization can be carried out in a temperature range of 0 to 350°C, but is preferably 50 to 250°C. The reaction can be carried out without a solvent, but is preferably carried out in a solvent. Examples of usable solvents include aprotic polar solvents such as N,N-dimethylacetamide, N,N-dimethylformamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, sulfolane, 1,3-dimethyl-2-imidazolidinone, and hexamethylphosphontriamide, but is not limited to these; any solvent that can be used as a stable solvent in the aromatic nucleophilic substitution reaction is acceptable. These organic solvents may be used individually or as a mixture of two or more.

[0149] Examples of basic compounds include sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate. However, any compound that can convert diols into an active phenoxide structure is acceptable and is not limited to these. In addition, it is preferable to add crown ethers such as 18-crown-6 to enhance the nucleophilicity of the phenoxide. Crown ethers can coordinate with the sodium or potassium ions of the sulfonic acid group, improving the solubility of the sulfonate portion of the monomer or polymer in organic solvents, and are therefore preferable to use.

[0150] In aromatic nucleophilic substitution reactions, water may be produced as a by-product. In such cases, the water can be removed from the system as an azeotrope by introducing toluene or other solvents into the reaction system, regardless of the polymerization solvent. Another method for removing water from the system is to use water-absorbing agents such as molecular sieves.

[0151] The block copolymer constituting the polymer electrolyte material of the present invention can be produced by synthesizing a block copolymer precursor and then deprotecting at least a portion of the protecting groups contained in the precursor. The method for producing the block copolymer and block copolymer precursor of the present invention preferably comprises at least the following steps (1) to (2). By comprising these steps, it is possible to achieve improved mechanical durability and durability through high molecular weight, and to obtain a block copolymer with excellent low-humidity proton conductivity, in which the phase separation structure and domain size are strictly controlled by the alternating introduction of both segments.

[0152] Step (1): A step in which, for one of two segments, an ionic segment having -OM groups (where M represents a hydrogen atom, a metal cation, or an ammonium cation) at both ends, and a nonionic segment having -OM groups at both ends, the -OM groups at both ends of that segment are reacted with a linker compound to introduce linker moieties at both ends of that segment. Step (2): A step to produce a block copolymer or block copolymer precursor having an ionic segment and a nonionic segment by polymerizing the linker moieties at both ends of the segment into which the linker moieties synthesized in step (1) are introduced with the -OM groups at both ends of the other segment.

[0153] Specific examples of segments represented by general formula (S1) and general formula (S2), where both ends are -OM groups, include segments with structures represented by the following general formulas (H3-1) and (H3-2), respectively. Furthermore, examples of structures obtained by reacting segments with structures represented by general formulas (H3-1) and (H3-2) with a halide linker include structures represented by the following general formulas (H3-3) and (H3-4), respectively. However, the present invention is not limited to these.

[0154] [ka]

[0155] In the above general formulas (H3-1) to (H3-4), N1, N2, N3, and N4 each independently represent integers from 1 to 200.

[0156] When the ionic segment has a linker, specific examples of the ionic segment with the linker portion introduced by step (1) above include structures represented by the following general formulas (H3-1L) and (H3-3L). However, the present invention is not limited to these.

[0157] [ka]

[0158] In the above general formulas (H3-1L) to (H3-3L), N5 and N6 each independently represent integers from 1 to 200.

[0159] In the general formulas (H3-1) to (H3-4), (H3-1L), and (H3-3L), halogen atoms are represented by F, terminal -OM groups by -OK groups, and alkali metals by Na and K, respectively. However, these formulas are not limited to these representations and can be used in any other way. Furthermore, these general formulas are inserted to aid the reader's understanding and do not necessarily accurately represent the chemical structure, exact composition, arrangement, position, number, or molecular weight of the polymer's polymerization components, nor are they limited to these representations.

[0160] Furthermore, in general formulas (H3-1) to (H3-4), (H3-1L), and (H3-3L), a ketal group was introduced as a protecting group for each segment. However, in the present invention, it is sufficient to introduce the protecting group to the component with high crystallinity and low solubility. Therefore, a protecting group is not necessarily required for the above ionic segments, and from the viewpoint of durability and dimensional stability, those without a protecting group can also be preferably used.

[0161] [Polymer electrolyte molded body] The electrolyte material of the present invention is suitable as a polymer electrolyte molded body. Here, a polymer electrolyte molded body means a molded body containing the electrolyte material of the present invention. Such polymer electrolyte molded bodies can take various forms depending on the application, including membranes (including films and film-like materials), plates, fibers, hollow fibers, parts, lumps, microporous materials, coatings, foams, etc. Among these, membranes are preferred because they can be adapted to a wide range of applications. Hereinafter, polymer electrolyte molded bodies of membrane type will be referred to as "electrolyte molded membranes." Hereinafter, electrolyte molded membranes will be described as representative examples of polymer electrolyte molded bodies, but the present invention is not limited to these.

[0162] Methods for manufacturing electrolyte-molded films include methods for forming films from a solution state at a stage where a protecting group such as ketal is present, or methods for forming films from a molten state. In the former method, for example, an electrolyte material can be dissolved in a solvent such as N-methyl-2-pyrrolidone, and the solution can be cast onto a glass plate or polyethylene terephthalate film (hereinafter referred to as PET film), and the solvent can be removed to form a film.

[0163] The solvent used for film formation can be any solvent that dissolves the electrolyte material and can then be removed. For example, aprotic polar solvents such as N,N-dimethylacetamide, N,N-dimethylformamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, sulfolane, 1,3-dimethyl-2-imidazolidinone, and hexamethylphosphontriamide are suitable; ester solvents such as γ-butyrolactone and butyl acetate are suitable; carbonate solvents such as ethylene carbonate and propylene carbonate are suitable; alkylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, and propylene glycol monoethyl ether are suitable; or alcohol solvents such as isopropanol, water, and mixtures thereof are suitable. However, aprotic polar solvents are preferred because they have the highest solubility. In addition, it is preferable to add crown ethers such as 18-crown-6 to increase the solubility of the ionic segment.

[0164] One method for converting the electrolyte material of the present invention into an electrolyte molded film involves, for example, forming a film composed of the electrolyte material using the above method, and then deprotecting at least a portion of the protected portion with a protecting group. For example, if the protecting group has a ketal moiety, at least a portion of the ketone moiety protected by the ketal is deprotected to become a ketone moiety. This method makes it possible to form a solution film of block copolymers with poor solubility, and to achieve both proton conductivity and mechanical and physical durability.

[0165] Alternatively, after forming a film in which the contained ionic groups have formed salts with alkali metal or alkaline earth metal cations, a step may be performed to exchange the alkali metal or alkaline earth metal cations for protons. This step is preferably a step of contacting the molded film with an acidic aqueous solution, and more preferably a step of immersing the molded film in an acidic aqueous solution. In this step, the protons in the acidic aqueous solution are replaced by the cations ionically bonded to the ionic groups, and residual water-soluble impurities, residual monomers, solvents, and residual salts are simultaneously removed.

[0166] The acidic aqueous solution is not particularly limited, but it is preferable to use sulfuric acid, hydrochloric acid, nitric acid, acetic acid, trifluoromethanesulfonic acid, methanesulfonic acid, phosphoric acid, citric acid, etc. The temperature and concentration of the acidic aqueous solution should be determined as appropriate, but from the viewpoint of productivity, it is preferable to use a sulfuric acid aqueous solution with a concentration of 3% to 30% by mass at a temperature of 0°C to 80°C.

[0167] In the present invention, the thickness of the electrolyte molded film is preferably 1 μm or more, more preferably 2 μm or more, and particularly preferably 3 μm or more, from the viewpoint of mechanical and physical durability. On the other hand, from the viewpoint of power generation performance, it is preferably 500 μm or less, more preferably 300 μm or less, and particularly preferably 200 μm or less.

[0168] Furthermore, the electrolyte-molded membrane may contain additives such as crystallization nucleating agents, plasticizers, stabilizers, antioxidants, or mold release agents commonly used in polymer compounds, to the extent that they do not contradict the objectives of the present invention.

[0169] Furthermore, the electrolyte molded membrane may contain various polymers, elastomers, fillers, fine particles, and various additives to improve mechanical strength, thermal stability, processability, etc., within limits that do not adversely affect the aforementioned properties. The electrolyte molded membrane may also be reinforced with microporous membranes, nonwoven fabrics, meshes, etc.

[0170] Electrolyte-molded membranes can be applied to a variety of uses. For example, they can be used in medical applications such as artificial skin, filtration applications, ion exchange resin applications such as chlorine-resistant reverse osmosis membranes, various structural material applications, electrochemical applications, humidifying membranes, anti-fogging membranes, antistatic membranes, deoxygenation membranes, solar cell membranes, and gas barrier membranes. They are particularly suitable for various electrochemical applications. Examples of electrochemical applications include polymer electrolyte fuel cells, redox flow batteries, water electrolyzers, chloro-alkali electrolyzers, electrochemical hydrogen pumps, and water electrolysis hydrogen generators.

[0171] In polymer electrolyte fuel cells, electrochemical hydrogen pumps, and water electrolysis hydrogen generators, the electrolyte molded membrane is used in a structure in which a catalyst layer, an electrode substrate, and a separator are sequentially laminated on both sides. Of these, the one in which a catalyst layer is laminated on both sides of the electrolyte molded membrane (i.e., a layer configuration of catalyst layer / electrolyte molded membrane / catalyst layer) is called a catalyst-layered electrolyte membrane (CCM), and the one in which a catalyst layer and a gas diffusion substrate are sequentially laminated on both sides of the electrolyte molded membrane (i.e., a layer configuration of gas diffusion substrate / catalyst layer / electrolyte molded membrane / catalyst layer / gas diffusion substrate) is called a membrane electrode assembly (MEA). The electrolyte material of the present invention is particularly suitable as an electrolyte molded membrane constituting such CCMs and MEAs.

[0172] Electrolyte molded films can be manufactured, for example, by casting an electrolyte solution (prepared by dissolving or dispersing an electrolyte material in a suitable solvent) onto a support substrate (such as a glass plate or PET film) and drying it. The electrolyte molded film thus obtained is subjected to acid treatment as needed, washed with water, and dried. In the drying process, the degree of crystallinity of the electrolyte molded film can be increased by drying at or above the glass transition temperature of the electrolyte material, or by heating at the above temperature after drying. The degree of crystallinity of the electrolyte molded film can be adjusted by controlling the heating temperature and heating time.

[0173] Furthermore, in the heating and pressing process when manufacturing the catalyst-layered electrolyte membrane (CCM) described above, the degree of crystallinity of the formed electrolyte membrane can be adjusted by controlling the heating temperature and pressing pressure. [Examples]

[0174] The present invention will be specifically described with reference to examples. However, the present invention is not limited to these examples. The measurement methods used in these examples are shown below. In the measurement methods described below, if measurement with block copolymers is difficult or if there are concerns about measurement accuracy, the following electrolyte membranes were used as samples instead of block copolymers.

[0175] <Preparation of electrolyte membrane (sample)> A 25 wt% N-methylpyrrolidone (NMP) solution containing a dissolved block copolymer was pressure-filtered using a glass fiber filter, then cast onto a glass substrate. After drying at 100°C for 4 hours, the film was heat-treated at 150°C under nitrogen for 10 minutes to obtain a 10 μm thick film. This film was then immersed in a 10 wt% sulfuric acid aqueous solution at 95°C for 24 hours to undergo proton substitution and deprotection reactions. After that, it was thoroughly washed and dried by immersion in a large excess of pure water for 24 hours to obtain an electrolyte film. The crystallinity of this electrolyte film (sample) by wide-angle X-ray diffraction (XRD) was 0%.

[0176] (1) Molecular weight of polymer The number-average molecular weight and weight-average molecular weight of polymers were measured by GPC. A Tosoh Corporation HLC-8022GPC integrated system with a UV detector and differential refractometer was used, along with a Tosoh Corporation TSKgelGuardColumnSuperH-H (4.6 mm inner diameter, 3.5 cm length) as the guard column and two Tosoh Corporation TSKgelSuperHM-H (6.0 mm inner diameter, 15 cm length) GPC columns. Measurements were taken in N-methyl-2-pyrrolidone solvent (containing 10 mmol / L lithium bromide) at a sample concentration of 0.1 wt%, a flow rate of 0.2 mL / min, a temperature of 40°C, and a measurement wavelength of 265 nm. The number-average molecular weight and weight-average molecular weight were then determined using standard polystyrene equivalents.

[0177] (2) Ion exchange capacity (IEC) The measurement was performed using the neutralization titration method described in 1) to 4) below. Three measurements were taken, and the average value was calculated. 1) After proton substitution and thorough washing with pure water, the moisture from the block copolymer was wiped off, and then vacuum-dried at 100°C for more than 12 hours, and the dry weight was determined. 2) 50 mL of 5 wt% sodium sulfate aqueous solution was added to the block copolymer and allowed to stand for 12 hours for ion exchange. 3) The resulting sulfuric acid was titrated using a 0.01 mol / L sodium hydroxide aqueous solution. A commercially available 0.1 w / v% titration phenolphthalein solution was added as an indicator, and the endpoint was reached when the solution turned a pale reddish-purple. 4) IEC was calculated using the following formula. IEC (meq / g) = [Concentration of sodium hydroxide solution (mmol / mL) × Droplet volume (mL)] / Dry weight of sample (g).

[0178] (3) Measurement of glass transition temperature Tg 10 mg of electrolyte material was pre-dried in a DSC instrument at 110°C for 3 hours. Then, without removing the sample from the DSC instrument, it was heated to 200°C under the following conditions, and temperature-modulated differential scanning calorimetry was performed during the heating phase. At this time, the glass transition temperature was defined as the midpoint of the two intersection points obtained from the two extensions of the baseline and the tangent to the endothermic curve. DSC device: DSC7000X (manufactured by Hitachi High-Tech Corporation) Measurement temperature range: 30℃~200℃ Temperature control: AC temperature control Heating rate: 2°C / min Amplitude: ±3℃ Applied frequency: 0.02Hz Sample pan: Aluminum crimped pan Measurement, pre-drying atmosphere: 100 mL / min nitrogen Pre-drying: 110°C, 3 hours.

[0179] (4) Measurement of saturation crystallinity The electrolyte membrane (sample) was cut into a 5cm x 5cm square, and this sample was sandwiched between two polyimide films (50μm thick). This was then heated and pressed in a heating press at a temperature of +5°C above the glass transition temperature of each block copolymer and a pressure of 4.5 MPa for 5 minutes. The degree of crystallinity was then measured, and this process was repeated until the degree of crystallinity stopped changing, which was defined as the saturated degree of crystallinity. The method for measuring the degree of crystallinity is described below. <Measuring crystallinity by wide-angle X-ray diffraction (XRD)> The sample, after being heated and pressed, was placed in a diffractometer, and X-ray diffraction measurements were performed under the following conditions. X-ray diffractometer: RIGAK RINT2500V X-ray: Cu-Kα X-ray output: 50kV-300mA Optical system: Concentration optical system Scan speed: 2θ = 2° / min Scanning method: 2θ-θ Scan range: 2θ = 5~60° Slits: Divergent slit -1 / 2°, Receiving slit -0.15mm, Scattering slit -1 / 2° By performing profile fitting on the X-ray diffraction measurement results, each component was separated, and the diffraction angle and integrated intensity of each component were determined. The degree of crystallinity was then calculated using the integrated intensities of the obtained crystalline peaks and amorphous halos from the following general formula (s2).

[0180] Crystallinity (%) = (Sum of integrated intensities of all crystalline peaks) / (Sum of integrated intensities of all crystalline peaks and amorphous halos) × 100 ... (s²).

[0181] (5) Measurement of crystallization calorimetry by differential scanning calorimetry (DSC) After pre-drying 10 mg of electrolyte membrane (sample) in a DSC instrument at 110°C for 3 hours, the sample was heated to 200°C under the following conditions without removing it from the DSC instrument, and temperature-modulated differential scanning calorimetry was performed during the heating stage. • Measurement temperature range: 30℃ to 200℃ • Temperature control: AC temperature control • Heating rate: 2°C / min ·Amplitude: ±3℃ ·Applied frequency: 0.02Hz • Sample pan: Aluminum crimped pan • Measurement and pre-drying atmosphere: 100 mL / min nitrogen.

[0182] (6) Observation of phase separation structure using a transmission electron microscope (TEM) Phase separation structure was confirmed using an electrolyte membrane (sample). The sample piece was immersed in a 2 wt% lead acetate aqueous solution as a staining agent and left at 25°C for 72 hours. The stained sample was removed and embedded in epoxy resin. An 80 nm thin section was cut using an ultramicrotome at room temperature, and the obtained thin section was collected on a Cu grid and subjected to TEM observation. Observation was performed at an acceleration voltage of 100 kV, and images were taken at magnifications of 10,000 to 100,000 times. The above magnifications were set appropriately according to the size of the phase separation structure. The instrument used was the HT7700 (manufactured by Hitachi High-Tech Corporation).

[0183] Furthermore, the TEM image was subjected to a Fast Fourier Transform (FFT), and the spatial frequencies in the TD and ZD directions were measured from the resulting ring-shaped FFT pattern. From this, the periodic size of the phase-separated structure was calculated. The spatial frequency was measured by the distance from the center of the image to the center of the ring's thickness. FFT and measurement were performed using a DigitalMicrograph (Gatan).

[0184] (7) Observation of phase separation structure by transmission electron microscopy (TEM) tomography The thin section samples prepared by the method described in (6) above were mounted on a collodion film, and observations were performed according to the following conditions. Equipment: Field emission electron microscope (HRTEM), JEOL Ltd. JEM 2100F Image acquisition: DigitalMicrograph (Gatan Corporation) System: Marker Method Acceleration voltage: 200kV Magnification: 30,000x Tilt angle: +60° to -62° Reconstruction resolution: 0.71nm / pixel Three-dimensional reconstruction was performed using the marker method. Au colloidal particles attached to a collodion film were used as alignment markers during three-dimensional reconstruction. Using the markers as a reference, the sample was tilted in 1° increments within the range of +61° to -62°, and TEM images were acquired from a series of 124 TEM images. CT reconstruction was performed based on these images, and the three-dimensional phase separation structure was observed.

[0185] (8) Proton conductivity An isopropanol-based carbon paste (G7711, manufactured by EM Japan Co., Ltd.) was applied to the platinum electrode of the cell, and a diffusion layer electrode (ELAT GDL 140-HT, manufactured by E-TEK) cut to 18 mm x 6 mm was attached. A rectangular electrolyte membrane (sample) cut to 30 mm x 8 mm was placed between the electrodes of the cell, and the cell was fastened at 1 MPa and placed inside the chamber of the MTS740. The proton resistance in the film thickness direction of the electrolyte membrane was evaluated using the MTS740 membrane resistance measurement system (manufactured by Scribner). The MTS740 housed the cell in a temperature-controlled chamber, and air gas was supplied into the chamber via a mass flow controller through a humidifier. A frequency response analyzer PSM1735 (manufactured by Newtons4th) was connected to the cell, and the resistance could be determined by sweeping the AC signal from 1 MHz to 1 kHz.

[0186] The MTS740 and PSM1735 can be connected to a PC and controlled by software. After setting the chamber temperature to 80°C, 90%RH air gas was supplied and held for 1 hour to sufficiently moisten the electrolyte membrane. Then, 20%RH air was supplied to dry it, and 30%RH air was supplied and held for 30 minutes, and the resistance was measured. During this time, the frequency was swept from 1MHz to 1kHz. Then, 80%RH air was supplied and held for 30 minutes, and the resistance was measured again. A Cole-Cole plot was created from the measured resistance data. Since the frequency band around 1MHz is affected by the inductance component of the cable connecting the cell and the PSM1735, the value on the real axis at 200kHz, where this effect is minimal, was used as the resistance value (Ω). The proton conductivity when 30%RH air was supplied was defined as low-humidified proton conductivity, and the proton conductivity when 80%RH air was supplied as high-humidified proton conductivity. The proton conductivity was calculated using the measured resistance values ​​with the following formula. Proton conductivity (mS / cm) = 1 / (resistance (Ω) × active area (cm) 2 ) / Sample thickness (cm).

[0187] The low-humidified proton conductivity is preferably 0.85 mS / cm or higher, more preferably 0.90 mS / cm or higher, even more preferably 1.00 mS / cm or higher, and particularly preferably 1.10 mS / cm or higher. The high-humidified proton conductivity is preferably 9.00 mS / cm or higher, more preferably 9.50 mS / cm or higher, even more preferably 11.00 mS / cm or higher, and particularly preferably 13.00 mS / cm or higher.

[0188] (9) Dimensional change rate between dry and wet The electrolyte membrane (sample) was cut into a 3mm x 20mm rectangle to prepare a sample piece. The sample piece was placed in the sample holder of a thermomechanical analyzer TMA / SS6100 (manufactured by Hitachi High-Tech Science Co., Ltd.) equipped with a temperature and humidity control furnace, with the longer side facing the measurement direction, and the stress was set to 20mN. The sample was allowed to stabilize in the furnace at 23°C and 50%RH for 1 hour, and the length of this sample piece was set as the zero point. The furnace temperature was fixed at 23°C, and the humidity was adjusted to 30%RH (dry conditions) over 30 minutes and held for 20 minutes. Next, the humidity was adjusted to 90%RH (humidified conditions) over 30 minutes. This dry-wet cycle (30%RH-90%RH) was considered one cycle, and the difference between the dimensional change rate (%) at 30%RH and the dimensional change rate (%) at 90%RH in the 10th cycle was defined as the dry-wet dimensional change rate (%). The dry-wet dimensional change rate is preferably 7.0% or less, more preferably 6.5% or less, even more preferably 6.0% or less, and particularly preferably 5.7% or less.

[0189] [Polymer synthesis] The structure of the compound obtained in the following synthesis example is: 1 The purity was confirmed by 1H-NMR. Purity was quantitatively analyzed by capillary electrophoresis (organic substances) and ion chromatography (inorganic substances).

[0190] <Synthesis Example 1> (Synthesis of 2,2-bis(4-hydroxyphenyl)-1,3-dioxolane (K-DHBP), represented by the following formula (G1)) In a 500 mL flask equipped with a stirrer, thermometer, and distillation tube, 49.5 g of 4,4'-dihydroxybenzophenone, 134 g of ethylene glycol, 96.9 g of trimethyl orthoformate, and 0.50 g of p-toluenesulfonic acid monohydrate were charged to form a solution. The solution was then kept warm and stirred at 78-82°C for 2 hours. The internal temperature was then gradually increased to 120°C and maintained at 120°C until the distillation of methyl formate, methanol, and trimethyl orthoformate completely stopped. After cooling the reaction solution to room temperature, it was diluted with ethyl acetate. The organic layer was washed with 100 mL of 5% potassium carbonate aqueous solution, and after liquid-liquid extraction, the solvent was removed by distillation. 80 mL of dichloromethane was added to the residue to precipitate crystals, which were filtered and dried to obtain 52.0 g of 2,2-bis(4-hydroxyphenyl)-1,3-dioxolane. The purity was 99.9%.

[0191] [ka]

[0192] <Synthesis Example 2> (Synthesis of disodium-3,3'-disulfonate-4,4'-difluorobenzophenone represented by the following formula (G2)) 109.1 g of 4,4'-difluorobenzophenone (Aldrich reagent) was reacted in 150 mL of fuming sulfuric acid (50% SO3) (Wako Pure Chemical Industries reagent) at 100°C for 10 hours. Then, the mixture was gradually added to a large volume of water, neutralized with NaOH, and 200 g of sodium chloride (NaCl) was added to precipitate the product. The resulting precipitate was filtered and recrystallized in an aqueous ethanol solution to obtain disodium-3,3'-disulfonate-4,4'-difluorobenzophenone. The purity was 99.3%.

[0193] [ka]

[0194] <Synthesis Example 3> (Synthesis of 3,3'-sodium disulfonate-4,4'-difluorodiphenyl sulfone, represented by the formula (G3) below) 109.1 g of 4,4-difluorodiphenylsulfone (Aldrich reagent) was reacted in 150 mL of fuming sulfuric acid (50% SO3) (Wako Pure Chemical Industries reagent) at 100°C for 10 hours. Then, the mixture was gradually added to a large volume of water, neutralized with NaOH, and 200 g of sodium chloride was added to precipitate the product. The precipitate was filtered and recrystallized in an aqueous ethanol solution to obtain 3,3'-disulfonate sodium salt-4,4'-difluorodiphenylsulfone. The purity was 99.3%.

[0195] [ka]

[0196] [Electrolyte material (I)] [Example 1] <Synthesis of nonionic oligomer a1 represented by the following general formula (G4)> In a 2,000 mL stainless steel polymerization apparatus equipped with a stirrer, nitrogen inlet tube, and Dean-Stark trap, 16.59 g of potassium carbonate (Aldrich reagent, 120 mmol), 25.83 g (100 mmol) of K-DHBP obtained in Synthesis Example 1, and 21.38 g of 4,4'-difluorobenzophenone (Aldrich reagent, 98 mmol) were added. After purging the apparatus with nitrogen, 300 mL of N-methylpyrrolidone (NMP) and 100 mL of toluene were added. Dehydration was performed at 150°C, followed by heating to remove the toluene, and polymerization was carried out at 170°C for 3 hours. Reprecipitation purification in a large amount of methanol was performed to obtain the terminal hydroxyl group of nonionic oligomer a1. The number-average molecular weight of the terminal hydroxyl group of this nonionic oligomer a1 was 20,000.

[0197] In a 500 mL three-necked flask equipped with a stirrer, nitrogen inlet tube, and Dean-Stark trap, 1.1 g of potassium carbonate (Aldrich reagent, 8 mmol) and 20.0 g (1 mmol) of the terminal hydroxyl group of the nonionic oligomer a1 were added. After purging the apparatus with nitrogen, 100 mL of NMP and 30 mL of toluene were added, and the mixture was dehydrated at 100 °C. The temperature was then raised to remove the toluene. Furthermore, 1.1 g of hexafluorobenzene (Aldrich reagent, 6 mmol) was added, and the reaction was carried out at 105 °C for 12 hours. Purification was performed by reprecipitation with a large amount of isopropyl alcohol to obtain nonionic oligomer a1 (terminal: fluoro group) represented by the following general formula (G4). The number-average molecular weight of this nonionic oligomer a1 was 21,000. In general formula (G4), m represents an integer of 1 or more.

[0198] [ka]

[0199] <Synthesis of ionic oligomer a2 represented by the following general formula (G5)> In a 2,000 mL stainless steel polymerization apparatus equipped with a stirrer, nitrogen inlet tube, and Dean-Stark trap, 27.64 g of potassium carbonate (Aldrich reagent, 200 mmol), 12.91 g (50 mmol) of K-DHBP obtained in Synthesis Example 1, 9.31 g of 4,4'-biphenol (Aldrich reagent, 50 mmol), 41.60 g (98.5 mmol) of disodium-3,3'-disulfonate-4,4'-difluorobenzophenone obtained in Synthesis Example 2, and 26.40 g of 18-crown-6 (Wako Pure Chemical Industries, 100 mmol) were added. After purging the apparatus with nitrogen, 300 mL of NMP and 100 mL of toluene were added, dehydration was performed at 150°C, the temperature was raised to remove the toluene, and polymerization was carried out at 170°C for 6 hours. The oligomer a2 (terminal: OM group) represented by the following general formula (G5) was purified by reprecipitation with a large amount of isopropyl alcohol. The number-average molecular weight of this ionic oligomer a2 was 45,000. In general formula (G5), M represents a hydrogen atom, Na, or K, and n represents an integer of 1 or more.

[0200] [ka]

[0201] <Synthesis of the ionic oligomer a2' represented by the following general formula (G6)> In a 2,000 mL stainless steel polymerization apparatus equipped with a stirrer, nitrogen inlet tube, and Dean-Stark trap, 0.56 g of potassium carbonate (Aldrich reagent, 400 mmol) and 49.0 g of ionic oligomer a2 were added. After purging the apparatus with nitrogen, 500 mL of NMP was added, and the contents were dissolved at 60°C. Then, 19.8 g of hexafluorobenzene / NMP solution (1 wt%) was added. The reaction was carried out at 80°C for 18 hours to obtain an NMP solution containing ionic oligomer a2' (terminus: OM group) represented by general formula (G6). The number-average molecular weight of this ionic oligomer a2' was 90,000. In general formula (G6), M represents a hydrogen atom, Na, or K, and n represents an integer of 1 or more.

[0202] [ka]

[0203] <Synthesis of block copolymer b1> The block copolymer b1 contains the above oligomer a2' as an ionic segment and the above oligomer a1 as a nonionic segment.

[0204] In a 2,000 mL stainless steel polymerization apparatus equipped with a stirrer, nitrogen inlet tube, and Dean-Stark trap, 49.0 g of ionic oligomer a2' and 7.65 g of nonionic oligomer a1 were added. NMP was added to bring the total amount of oligomers to 7 wt%, and the reaction was carried out at 105°C for 24 hours. Reprecipitation was performed in a large amount of isopropyl alcohol / NMP mixture (weight ratio 2 / 1), and purification was performed with a large amount of isopropyl alcohol to obtain block copolymer b1. The number-average molecular weight of this block copolymer b1 was 170,000, and the weight-average molecular weight was 410,000.

[0205] The saturation crystallinity of block copolymer b1 was 11.6%, the glass transition temperature was 157 °C, and the IEC was 2.5 meq / g. For the electrolyte membrane prepared using block copolymer b1, a co-continuous phase separation structure (both the hydrophilic domain containing ionic groups and the hydrophobic domain not containing ionic groups form continuous phases) was confirmed.

[0206] [Example 2] [Synthesis of block copolymer b2] Block copolymer b2 contains the above oligomer a2’ as the ionic segment and the above oligomer a1 as the non-ionic segment.

[0207] Block copolymer b2 was obtained in the same manner as in Example 1 except that the amount of non-ionic oligomer a1 used was 5.4 g. The number average molecular weight of this block copolymer b2 was 180,000, and the weight average molecular weight was 430,000.

[0208] The saturation crystallinity of block copolymer b2 was 9.2%, the glass transition temperature was 160 °C, and the IEC was 2.7 meq / g. For the electrolyte membrane prepared using block copolymer b2, a co-continuous phase separation structure (both the hydrophilic domain containing ionic groups and the hydrophobic domain not containing ionic groups form continuous phases) was confirmed.

[0209] [Example 3] [Synthesis of non-ionic oligomer a3 represented by the above general formula (G4)] The terminal hydroxy form of oligomer a3 was obtained in the same manner as the synthesis of the terminal hydroxy form of oligomer a1 except that the amount of 4,4'-difluorobenzophenone used was 21.45 g. The number average molecular weight of this terminal hydroxy form of oligomer a3 was 25,000.

[0210] A nonionic oligomer a3 (terminal: fluoro group) represented by the general formula (G4) was obtained in the same manner as the synthesis of oligomer a1, except that 25.0 g of the terminal hydroxy form of oligomer a3 was used instead of the terminal hydroxy form of oligomer a1. The number average molecular weight of this nonionic oligomer a3 was 26,000.

[0211] <Synthesis of block copolymer b3> The block copolymer b3 contains the above oligomer a2’ as an ionic segment and the above oligomer a3 as a nonionic segment.

[0212] A block copolymer b3 was obtained in the same manner as the synthesis of block copolymer b1, except that 12.3 g of nonionic oligomer a3 was used instead of 7.65 g of nonionic oligomer a1. The number average molecular weight of this block copolymer b3 was 160,000, and the weight average molecular weight was 390,000.

[0213] The saturated crystallinity of the block copolymer b3 was 15.6%, the glass transition temperature was 160 °C, and the IEC was 2.1 meq / g. An electrolyte membrane prepared using the block copolymer b3 was confirmed to have a co-continuous-like phase separation structure (both a hydrophilic domain containing ionic groups and a hydrophobic domain containing no ionic groups form continuous phases).

[0214] [Example 4] <Synthesis of nonionic oligomer a5 represented by the above general formula (G4)> A terminal hydroxy form of oligomer a5 was obtained in the same manner as the synthesis of the terminal hydroxy form of oligomer a1, except that the amount of 4,4'-difluorobenzophenone used was 21.51 g. The number average molecular weight of this terminal hydroxy form of oligomer a5 was 29,000.

[0215] Nonionic oligomer a5 (terminal: fluoro group), represented by general formula (G4), was obtained in the same manner as the synthesis of oligomer a1, except that 29.0 g of the terminal hydroxyl group of oligomer a5 was used instead of the terminal hydroxyl group of oligomer a1. The number-average molecular weight of this nonionic oligomer a5 was 30,000.

[0216] <Synthesis of ionic oligomer a4 represented by the above general formula (G5)> Ionic oligomer a4 was obtained in the same manner as the synthesis of ionic oligomer a2, except that the amount of disodium-3,3'-disulfonate-4,4'-difluorobenzophenone used was 41.38 g (98.0 mmol). The number-average molecular weight of this ionic oligomer a4 was 35,000.

[0217] <Synthesis of ionic oligomer a4' represented by the following general formula (G7)> In a 2,000 mL stainless steel polymerization apparatus equipped with a stirrer, nitrogen inlet tube, and Dean-Stark trap, 0.56 g of potassium carbonate (Aldrich reagent, 400 mmol) and 37.16 g of ionic oligomer a4 were added. After purging the apparatus with nitrogen, 400 mL of NMP was added, and the contents were dissolved at 60°C. Then, 11.4 g of 2,6-difluorobenzonitrile / NMP solution (1 wt%) was added. The reaction was carried out at 80°C for 18 hours to obtain an NMP solution containing ionic oligomer a4' (terminus: OM group) represented by general formula (G7). The number-average molecular weight of this ionic oligomer a4' was 70,000. In general formula (G7), M represents a hydrogen atom, Na, or K, and n represents an integer of 1 or more.

[0218] [ka]

[0219] <Synthesis of block copolymer b4> The block copolymer b4 contains the above oligomer a4' as an ionic segment and the above oligomer a5 as a nonionic segment.

[0220] Block copolymer b4 was obtained in the same manner as the synthesis of block copolymer b1, except that ionic oligomer a4' (37.16 g) was used instead of ionic oligomer a2' (49.0 g), and nonionic oligomer a5 (12.39 g) was used instead of nonionic oligomer a1 (7.65 g). The number-average molecular weight of this block copolymer b4 was 120,000, and the weight-average molecular weight was 360,000.

[0221] The saturated crystallinity of block copolymer b4 was 18.0%, the glass transition temperature was 160°C, and the IEC was 1.9 meq / g. The electrolyte membrane fabricated using block copolymer b4 showed a co-continuous-like phase separation structure (where hydrophilic domains containing ionic groups and hydrophobic domains not containing ionic groups both form a continuous phase).

[0222] [Example 5] <Synthesis of nonionic oligomer a7 represented by the above general formula (G4)> The terminal hydroxyl derivative of nonionic oligomer a7 was obtained in the same manner as the synthesis of the terminal hydroxyl derivative of nonionic oligomer a1, except that 21.27 g of 4,4'-difluorobenzophenone was used. The number-average molecular weight of this terminal hydroxyl derivative of nonionic oligomer a7 was 16,000.

[0223] Nonionic oligomer a7 (terminal: fluoro group), represented by general formula (G4), was obtained in the same manner as the synthesis of nonionic oligomer a1, except that the terminal hydroxyl form (16.0 g) of nonionic oligomer a7 was used instead of the terminal hydroxyl form (20.0 g) of nonionic oligomer a1. The number-average molecular weight of this nonionic oligomer a7 was 17,000.

[0224] <Synthesis of ionic oligomer a6 represented by the above general formula (G5)> In a 2,000 mL SUS polymerization apparatus equipped with a stirrer, a nitrogen introduction tube, and a Dean-Stark trap, 27.64 g (Aldrich reagent, 200 mmol) of potassium carbonate, 12.91 g (50 mmol) of K-DHBP obtained in Synthesis Example 1, 9.31 g (Aldrich reagent, 50 mmol) of 4,4'-biphenol, and 41.85 g (99.1 mmol) of disodium-3,3'-disulfonate-4,4'-difluorobenzophenone obtained in Synthesis Example 2 were added. After purging the inside of the apparatus with nitrogen, 300 mL of dimethyl sulfoxide (DMSO) and 100 mL of toluene were added. After dehydration at 133 °C, the temperature was raised to remove toluene, and polymerization was carried out at 150 °C for 2 hours. The temperature was further raised to 155 °C and polymerization was carried out for another 1 hour. Purification was performed by reprecipitation with a large amount of isopropyl alcohol to obtain an ionic oligomer a6 (end: OM group) represented by the general formula (G5). The number average molecular weight of this ionic oligomer a6 was 56,000.

[0225] <Synthesis of block copolymer b5> The block copolymer b5 contains the oligomer a6 as an ionic segment and the oligomer a7 as a non-ionic segment.

[0226] A block copolymer b5 was obtained in the same manner as the synthesis of the block copolymer b1, except that the ionic oligomer a6 (32.79 g) was used instead of the ionic oligomer a2' (49.0 g), and the non-ionic oligomer a7 (8.19 g) was used instead of the non-ionic oligomer a1 (7.65 g). The number average molecular weight of this block copolymer b5 was 140,000, and the weight average molecular weight was 360,000.

[0227] The saturated crystallinity of the block copolymer b5 was 13.5%, the glass transition temperature was 159 °C, and the IEC was 2.1 meq / g. In the electrolyte membrane prepared using the block copolymer b5, a co-continuous phase separation structure (both a hydrophilic domain containing an ionic group and a hydrophobic domain not containing an ionic group form a continuous phase) was confirmed.

[0228] [Comparative Example 1] <Synthesis of nonionic oligomer a9 represented by the above general formula (G4)> The terminal hydroxyl derivative of nonionic oligomer a9 was obtained in the same manner as the synthesis of the terminal hydroxyl derivative of nonionic oligomer a1, except that 20.4 g of 4,4'-difluorobenzophenone was used. The number-average molecular weight of this terminal hydroxyl derivative of nonionic oligomer a9 was 7,000.

[0229] Nonionic oligomer a9 (terminal: fluoro group), represented by general formula (G4), was obtained in the same manner as the synthesis of nonionic oligomer a1, except that the terminal hydroxyl form (9.0 g: 1 mmol) of nonionic oligomer a9 was used instead of the terminal hydroxyl form (20.0 g) of nonionic oligomer a1. The number-average molecular weight of this nonionic oligomer a9 was 8,000.

[0230] <Synthesis of ionic oligomer a8 represented by the above general formula (G5)> In a 2,000 mL SUS polymerization apparatus equipped with a stirrer, nitrogen inlet tube, and Dean-Stark trap, 27.64 g of potassium carbonate (Aldrich reagent, 200 mmol), 12.91 g (50 mmol) of K-DHBP obtained in Synthesis Example 1, 9.31 g of 4,4'-biphenol (Aldrich reagent, 50 mmol), 41.47 g (98.2 mmol) of disodium-3,3'-disulfonate-4,4'-difluorobenzophenone obtained in Synthesis Example 2, and 18- Crown-6 (26.40 g: Wako Pure Chemical Industries 100 mmol) was added. After purging the apparatus with nitrogen, 300 mL of NMP and 100 mL of toluene were added, and dehydration was performed at 150°C. The temperature was then raised to remove the toluene, and polymerization was carried out at 170°C for 6 hours. Purification was performed by reprecipitation with a large amount of isopropyl alcohol to obtain ionic oligomer a8 (terminus: hydroxyl group) represented by general formula (G5). The number average molecular weight of this ionic oligomer a8 was 42,000.

[0231] <Synthesis of block copolymer b6> The block copolymer b6 contains oligomer a8 as an ionic segment and oligomer a9 as a nonionic segment. Block copolymer b6 was obtained in the same manner as the synthesis of block copolymer b1, except that ionic oligomer a8 (43.57 g) was used instead of ionic oligomer a2' (49.0 g), and nonionic oligomer a9 (10.89 g) was used instead of nonionic oligomer a1 (7.65 g). The number-average molecular weight of this block copolymer b6 was 140,000, and the weight-average molecular weight was 400,000.

[0232] The saturated crystallinity of block copolymer b6 was 4.1%, the glass transition temperature was 157°C, and the IEC value was 2.2 meq / g. Electrolyte membranes fabricated using block copolymer b6 exhibited a co-continuous-like phase separation structure (where hydrophilic domains containing ionic groups and hydrophobic domains without ionic groups form a continuous phase).

[0233] [Comparative Example 2] (Synthesis of nonionic oligomer a11 represented by the above general formula (G4)) The terminal hydroxyl derivative of nonionic oligomer a11 was obtained in the same manner as the synthesis of the terminal hydroxyl derivative of nonionic oligomer a1, except that 20.18 g of 4,4'-difluorobenzophenone was used. The number-average molecular weight of this terminal hydroxyl derivative of nonionic oligomer a11 was 5,000.

[0234] In a 500 mL three-necked flask equipped with a stirrer, nitrogen inlet tube, and Dean-Stark trap, 2.2 g of potassium carbonate (Aldrich reagent, 16 mmol) and 10.0 g of the terminal hydroxyl group of nonionic oligomer a11 were placed. After purging the apparatus with nitrogen, 100 mL of NMP and 30 mL of toluene were added, and the mixture was dehydrated at 100 °C. After raising the temperature to remove the toluene, 2.2 g of hexafluorobenzene (Aldrich reagent, 12 mmol) was added, and the reaction was carried out at 105 °C for 12 hours. Purification was performed by reprecipitation with a large amount of isopropyl alcohol to obtain nonionic oligomer a11 (terminal: fluoro group) represented by general formula (G4). The number-average molecular weight of this nonionic oligomer a11 was 6,000.

[0235] <Synthesis of block copolymer b7> The block copolymer b7 contains the above oligomer a8 as an ionic segment and the above oligomer a11 as a nonionic segment.

[0236] Block copolymer b7 was obtained in the same manner as the synthesis of block copolymer b6, except that nonionic oligomer a11 (6.81 g) was used instead of nonionic oligomer a9 (10.89 g). The number-average molecular weight of block copolymer b7 was 130,000, and the weight-average molecular weight was 400,000.

[0237] The saturated crystallinity of block copolymer b7 was 0.8%, the glass transition temperature was 157°C, and the IEC was 2.4 meq / g. Electrolyte membranes fabricated using block copolymer b7 exhibited a co-continuous-like phase separation structure (where hydrophilic domains containing ionic groups and hydrophobic domains without ionic groups form a continuous phase), although some discontinuous structures were observed.

[0238] [Comparative Example 3] <Synthesis of nonionic oligomer a13 represented by the following general formula (G8)> The terminal hydroxyl group of nonionic oligomer a13 was obtained in the same manner as the synthesis of the terminal hydroxyl group of nonionic oligomer a1, except that 23.65 g of 4,4'-difluorodiphenylsulfone was used instead of 4,4'-difluorobenzophenone. The number-average molecular weight of this terminal hydroxyl group of nonionic oligomer a13 was 10,000.

[0239] Nonionic oligomer a13 (terminal fluoro group), represented by general formula (G8), was obtained in the same manner as the synthesis of nonionic oligomer a1, except that 10.0 g of the terminal hydroxyl group of nonionic oligomer a13 was used instead of 20.0 g of the terminal hydroxyl group of nonionic oligomer a11. The number-average molecular weight of this nonionic oligomer a13 was 11,000. In general formula (G8), m represents an integer of 1 or more.

[0240] [ka]

[0241] <Synthesis of ionic oligomer a12 represented by the following general formula (G9)> Ionic oligomer a12 (terminus: OM group) represented by general formula (G9) was obtained in the same manner as the synthesis of ionic oligomer a2, except that 44.94 g (98.1 mmol) of sodium 3,3'-disulfonate-4,4'-difluorodiphenylsulfone obtained in Synthesis Example 3 was used instead of 41.60 g of disodium-3,3'-disulfonate-4,4'-difluorobenzophenone. The number-average molecular weight of this ionic oligomer a12 was 41,000. In general formula (G9), M represents a hydrogen atom, Na, or K, and n represents an integer of 1 or more.

[0242] [ka]

[0243] <Synthesis of block copolymer b8> The block copolymer b8 contains the above oligomer a12 as an ionic segment and the above oligomer a13 as a nonionic segment.

[0244] In a 2,000 mL SUS polymerization apparatus equipped with a stirrer, nitrogen inlet tube, and Dean-Stark trap, ionic oligomer a12 (45.76 g) and nonionic oligomer a13 (8.93 g) were added, and NMP was added to bring the total amount of oligomers to 7 wt%, and the reaction was carried out at 105°C for 24 hours. Reprecipitation was performed in a large amount of isopropyl alcohol / NMP mixture (weight ratio 2 / 1), and purification was performed with a large amount of isopropyl alcohol to obtain block copolymer b8. The number-average molecular weight of this block copolymer b8 was 120,000, and the weight-average molecular weight was 290,000.

[0245] The saturated crystallinity of block copolymer b8 was 0.0%, the glass transition temperature was 231°C, and the IEC value was 2.4 meq / g. Electrolyte membranes fabricated using block copolymer b8 exhibited a co-continuous-like phase separation structure (where hydrophilic domains containing ionic groups and hydrophobic domains not containing ionic groups form a continuous phase).

[0246] [Measurement results] Table 1 shows the measurement results of the electrolyte materials obtained in Examples 1-5 and Comparative Examples 1-3, as well as the evaluation results of proton conductivity and wet / dry dimensional change rate.

[0247] [Table 1]

[0248] In Examples 1 to 5, an electrolyte material (I) with a saturation crystallinity of 5% to 30% was used, resulting in a small change in dimensional properties between dry and wet conditions, and high proton conductivity at both low and high humidity levels. In other words, a relatively high level of both mechanical durability and proton conductivity was achieved.

[0249] On the other hand, Comparative Examples 1-3 all have a saturation crystallinity of less than 5%. As a result, they exhibit inferior dimensional change rates (both wet and dry) or proton conductivity. In other words, they do not achieve both mechanical durability and proton conductivity.

[0250] [Examples 11-15] Electrolyte membranes (samples) with a "crystallinity of 0%" prepared using the electrolyte materials of Examples 1 to 5 described above were heated and pressed under the conditions described in "(4) Measurement of Saturated Crystallinity" when the crystallinity no longer changed. These samples were then used to measure the dry-wet dimensional change rate and proton conductivity. The results are shown in Table 2.

[0251] [Table 2]

[0252] As shown in Examples 1 to 5 of Table 1, electrolyte membranes (samples) made from the electrolyte material (I) of the present invention exhibit a relatively high level of both mechanical durability (dry / wet dimensional change rate) and proton conductivity even without crystallization (even if the degree of crystallinity is 0%). However, by promoting crystallization, the mechanical durability (dry / wet dimensional change rate) and proton conductivity are further improved, as shown in Table 2.

[0253] [Electrolyte material (II)] [Example 21] <Block copolymer b21> The aforementioned block copolymer b1 was used as block copolymer b21. A crystallization peak was observed in block copolymer b21 by DSC, and the heat of crystallization was 15.8 J / g. Therefore, the product of IEC and the heat of crystallization was 39.5.

[0254] [Example 22] <Block copolymer b22> The aforementioned block copolymer b2 was used as block copolymer b22. A crystallization peak was observed in block copolymer b22 by DSC, and the heat of crystallization was 13.2 J / g. Therefore, the product of IEC and the heat of crystallization was 35.6.

[0255] [Example 23] <Synthesis of ionic oligomer a24 represented by the above general formula (G5)> Ionic oligomer a24 was obtained in the same manner as the synthesis of ionic oligomer a2, except that the amount of disodium-3,3'-disulfonate-4,4'-difluorobenzophenone used was 41.38 g (98.0 mmol). The number-average molecular weight of this ionic oligomer a24 was 35,000.

[0256] <Synthesis of the ionic oligomer a24' represented by the above general formula (G6)> An NMP solution containing the ionic oligomer a24' (terminus: OM group), represented by general formula (G6), was obtained in the same manner as the synthesis of ionic oligomer a2', except that ionic oligomer a24 (37.16 g) was used instead of ionic oligomer a2 (49.0 g), the amount of NMP used was 400 mL, and the amount of hexafluorobenzene / NMP solution (1 wt%) used was 15.3 g. The number-average molecular weight of this oligomer a24' was 70,000.

[0257] <Synthesis of block copolymer b23> The block copolymer b23 contains the above oligomer a24' as an ionic segment and the above oligomer a1 as a nonionic segment.

[0258] Block copolymer b23 was obtained in the same manner as the synthesis of block copolymer b1, except that ionic oligomer a24' (37.16 g) was used instead of ionic oligomer a2' (49.0 g) in a 2,000 mL SUS polymerization apparatus equipped with a stirrer, nitrogen inlet tube, and Dean-Stark trap, and the amount of nonionic oligomer a1 used was 5.80 g. The number average molecular weight of this block copolymer b23 was 190,000, and the weight average molecular weight was 440,000.

[0259] The IEC of the block copolymer b23 was 2.4 meq / g. The electrolyte membrane prepared using the block copolymer b23 showed a co-continuous-like phase separation structure (where hydrophilic domains containing ionic groups and hydrophobic domains not containing ionic groups form a continuous phase). Furthermore, a crystallization peak was observed by DSC, and the heat of crystallization was 16.6 J / g. Therefore, the product of IEC and heat of crystallization was 39.8.

[0260] [Example 24] <Synthesis of nonionic oligomer a21 represented by the following general formula (G10)> In a 500 mL three-necked flask equipped with a stirrer, nitrogen inlet tube, and Dean-Stark trap, 1.1 g of potassium carbonate (Aldrich reagent, 8 mmol) and 20.0 g (1 mmol) of the terminal hydroxyl group of nonionic oligomer a1 were added. After purging the apparatus with nitrogen, 100 mL of NMP and 30 mL of toluene were added, and the mixture was dehydrated at 100 °C. The temperature was then raised to remove the toluene. Subsequently, 0.84 g of 2,6-difluorobenzonitrile (Aldrich reagent, 6 mmol) was added, and the reaction was carried out at 105 °C for 12 hours. Purification was performed by reprecipitation with a large amount of isopropyl alcohol to obtain nonionic oligomer a21 (terminal: fluoro group) represented by the following general formula (G10). The number-average molecular weight of this nonionic oligomer a21 was 21,000. In general formula (G10), m represents an integer of 1 or greater.

[0261] [ka]

[0262] <Synthesis of the ionic oligomer a24'' represented by the following general formula (G11)> In a 2,000 mL stainless steel polymerization apparatus equipped with a stirrer, nitrogen inlet tube, and Dean-Stark trap, 0.56 g of potassium carbonate (Aldrich reagent, 400 mmol) and 37.16 g of ionic oligomer a24 were added. After purging the apparatus with nitrogen, 400 mL of NMP was added, and the contents were dissolved at 60°C. Then, 11.4 g of 2,6-difluorobenzonitrile / NMP solution (1 wt%) was added. The reaction was carried out at 80°C for 18 hours to obtain an NMP solution containing the ionic oligomer a24'' (terminus: OM group) represented by general formula (G11). The number-average molecular weight of this ionic oligomer a24'' was 70,000. In general formula (G11), M represents a hydrogen atom, Na, or K, and n represents an integer of 1 or more.

[0263] [ka]

[0264] <Synthesis of block copolymer b24> The block copolymer b24 contains the above oligomer a24'' as an ionic segment and the above oligomer a21 as a nonionic segment.

[0265] Block copolymer b24 was obtained in the same manner as the synthesis of block copolymer b1, except that ionic oligomer a24'' (37.16 g) was used instead of ionic oligomer a2' (49.0 g), and the amount of nonionic oligomer a21 used was 5.80 g. The number-average molecular weight of this block copolymer b24 was 100,000, and the weight-average molecular weight was 260,000.

[0266] The IEC of the block copolymer b24 was 2.2 meq / g. The electrolyte membrane prepared using the block copolymer b24 showed a co-continuous-like phase separation structure (where hydrophilic domains containing ionic groups and hydrophobic domains not containing ionic groups form a continuous phase). Furthermore, a crystallization peak was observed by DSC, and the heat of crystallization was 20.1 J / g. Therefore, the product of IEC and heat of crystallization was 44.2.

[0267] [Example 25] <Synthesis of block copolymer b25> The block copolymer b25 contains the above oligomer a24'' as an ionic segment and the above oligomer a1 as a nonionic segment.

[0268] Block copolymer b25 was obtained in the same manner as the synthesis of block copolymer b24, except that nonionic oligomer a1 (9.29 g) was used instead of nonionic oligomer a21 (5.80 g). The number-average molecular weight of this block copolymer b25 was 150,000, and the weight-average molecular weight was 380,000.

[0269] The IEC of the block copolymer b25 was 2.1 meq / g. The electrolyte membrane prepared using the block copolymer b25 showed a co-continuous-like phase separation structure (where hydrophilic domains containing ionic groups and hydrophobic domains not containing ionic groups form a continuous phase). Furthermore, a crystallization peak was observed by DSC, and the heat of crystallization was 22.0 J / g. Therefore, the product of IEC and heat of crystallization was 46.2.

[0270] [Example 26] <Block copolymer b26> The aforementioned block copolymer b5 was used as block copolymer b26. A crystallization peak was observed in block copolymer b26 by DSC, and the heat of crystallization was 21.1 J / g. Therefore, the product of IEC and the heat of crystallization was 44.3.

[0271] [Example 27] <Synthesis of block copolymer b27> The block copolymer b27 contains the above oligomer a2' as an ionic segment and the above oligomer a1 as a nonionic segment.

[0272] Block copolymer b27 was obtained in the same manner as in Example 1, except that the amount of nonionic oligomer a1 used was 4.1 g. The number-average molecular weight of this block copolymer b27 was 160,000, and the weight-average molecular weight was 410,000.

[0273] The IEC of the block copolymer b27 was 2.9 meq / g. The electrolyte membrane prepared using the block copolymer b27 showed a co-continuous-like phase separation structure (where hydrophilic domains containing ionic groups and hydrophobic domains not containing ionic groups form a continuous phase). Furthermore, a crystallization peak was observed by DSC, and the heat of crystallization was 12.1 J / g. Therefore, the product of IEC and heat of crystallization was 35.1.

[0274] [Comparative Example 21] <Synthesis of nonionic oligomer a31 represented by the following general formula (G12)> In a 2,000 mL stainless steel polymerization apparatus equipped with a stirrer, nitrogen inlet tube, and Dean-Stark trap, 16.59 g of potassium carbonate (Aldrich reagent, 120 mmol), 25.8 g (100 mmol) of K-DHBP obtained in Synthesis Example 1, and 20.3 g of 4,4'-difluorobenzophenone (Aldrich reagent, 93 mmol) were added. After purging the apparatus with nitrogen, 300 mL of NMP and 100 mL of toluene were added, and dehydration was performed at 160 °C. The temperature was then increased to remove the toluene, and polymerization was carried out at 180 °C for 1 hour. Reprecipitation and purification in a large amount of methanol were performed to obtain the terminal hydroxyl group of the nonionic oligomer a31. The number-average molecular weight of the terminal hydroxyl group of this nonionic oligomer a31 was 10,000.

[0275] In a 500 mL three-necked flask equipped with a stirrer, nitrogen inlet tube, and Dean-Stark trap, 1.1 g of potassium carbonate (Aldrich reagent, 8 mmol) and 20.0 g (2 mmol) of the terminal hydroxyl group of nonionic oligomer a31 were added. After purging the apparatus with nitrogen, 100 mL of NMP and 30 mL of cyclohexane were added, and dehydration was carried out at 100 °C. The temperature was then raised to remove the cyclohexane, and 4.0 g of decafluorobiphenyl (Aldrich reagent, 12 mmol) was added. The reaction was carried out at 105 °C for 1 hour. Purification was performed by reprecipitation with a large amount of isopropyl alcohol to obtain nonionic oligomer a31 (terminal: fluoro group) represented by the following general formula (G12). The number-average molecular weight of this nonionic oligomer a31 was 11,000. In general formula (G12), m represents an integer of 1 or more.

[0276] [ka]

[0277] <Synthesis of ionic oligomer a32 represented by the above general formula (G5)> A 2,000 mL SUS polymerization apparatus equipped with a stirrer, nitrogen inlet tube, and Dean-Stark trap contained 27.6 g of potassium carbonate (Aldrich reagent, 200 mmol), 12.9 g (50 mmol) of K-DHBP obtained in Synthesis Example 1, 9.3 g of 4,4'-biphenol (Aldrich reagent, 50 mmol), 39.3 g (93 mmol) of disodium-3,3'-disulfonate-4,4'-difluorobenzophenone obtained in Synthesis Example 2, and 17.9 g of 18-crown-6 ether (Wako Pure Chemical Industries, 82 mmol). After purging the apparatus with nitrogen, 300 mL of NMP and 100 mL of toluene were added. Dehydration was performed at 170 °C, then the temperature was increased to remove the toluene, and polymerization was carried out at 180 °C for 1 hour. The oligomer a22 (terminus: OM group) represented by the above general formula (G5) was purified by reprecipitation with a large amount of isopropyl alcohol. The number-average molecular weight of this ionic oligomer a32 was 16,000.

[0278] <Synthesis of block copolymer b31> The block copolymer b31 contains the above oligomer a32 as an ionic segment and the above oligomer a31 as a nonionic segment.

[0279] In a 500 mL three-necked flask equipped with a stirrer, nitrogen inlet tube, and Dean-Stark trap, 0.56 g of potassium carbonate (Aldrich reagent, 4 mmol) and 16 g (1 mmol) of ionic oligomer a32 were added. After purging the apparatus with nitrogen, 100 mL of NMP and 30 mL of cyclohexane were added, and dehydration was carried out at 100 °C. The temperature was then raised to remove the cyclohexane, and 11 g (1 mmol) of nonionic oligomer a31 was added. The reaction was carried out at 105 °C for 24 hours. Block copolymer b31 was obtained by reprecipitation and purification with a large amount of isopropyl alcohol. The number-average molecular weight of this block copolymer b31 was 150,000, and the weight-average molecular weight was 340,000.

[0280] The IEC of the block copolymer b31 was 1.7 meq / g. The electrolyte membrane prepared using the block copolymer b31 showed a co-continuous-like phase separation structure (where hydrophilic domains containing ionic groups and hydrophobic domains not containing ionic groups form a continuous phase). Furthermore, a crystallization peak was observed by DSC, and the heat of crystallization was 22.5 J / g. Therefore, the product of IEC and heat of crystallization was 38.3.

[0281] [Comparative Example 22] (Synthesis of nonionic group oligomer a33 represented by the following general formula (G13)) In the synthesis of nonionic oligomer 31 in Comparative Example 21, 18.62 g of 4,4'-biphenol (Aldrich reagent, 100 mmol) was used instead of 25.8 g (100 mmol) of K-DHBP, and the amount of 4,4'-difluorobenzophenone added was changed to 21.41 g. The nonionic oligomer a33 was synthesized in the same manner as in Comparative Example 21. The number-average molecular weight was 22,000.

[0282] Furthermore, nonionic oligomer a33 (terminal: fluoro group) was synthesized in the same manner as in Comparative Example 21, except that 50.0 g (2 mmol) of the terminal hydroxyl form of nonionic oligomer a33 was added instead of the terminal hydroxyl form of nonionic oligomer a31. The number-average molecular weight was 23,000. In general formula (G13), m represents an integer of 1 or more.

[0283] [ka]

[0284] <Synthesis of ionic group oligomer a34 represented by the above general formula (G5)> A 2,000 mL SUS polymerization apparatus equipped with a stirrer, nitrogen inlet tube, and Dean-Stark trap contained 27.6 g of potassium carbonate (Aldrich reagent, 200 mmol), 25.8 g (100 mmol) of K-DHBP obtained in Synthesis Example 1, 41.4 g (98.1 mmol) of disodium-3,3'-disulfonate-4,4'-difluorobenzophenone obtained in Synthesis Example 2, and 17.9 g (82 mmol) of 18-crown-6 ether. After purging the apparatus with nitrogen, 300 mL of NMP and 100 mL of toluene were added. Dehydration was performed at 170°C, then the temperature was increased to remove the toluene, and polymerization was carried out at 180°C for 1 hour. Purification was performed by reprecipitation with a large amount of isopropyl alcohol to obtain the ionic oligomer a34 (terminus: OM group) represented by the above general formula (G5). The number-average molecular weight of this ionic oligomer a34 was 28,000.

[0285] <Synthesis of block copolymer b32> The block copolymer b32 contains the above oligomer a34 as an ionic segment and the above oligomer a33 as a nonionic segment.

[0286] Block copolymer b32 was obtained in the same manner as in Comparative Example 21, except that 26 g (1 mmol) of ionic oligomer a34 was added instead of ionic oligomer a32, and 21 g (1 mmol) of nonionic oligomer a33 was added instead of nonionic oligomer a31. The number-average molecular weight of this block copolymer b32 was 110,000, and the weight-average molecular weight was 380,000.

[0287] The IEC of the block copolymer b32 was 1.9 meq / g. The electrolyte membrane prepared using the block copolymer b32 showed a co-continuous-like phase separation structure (where hydrophilic domains containing ionic groups and hydrophobic domains not containing ionic groups form a continuous phase). Furthermore, a crystallization peak was observed by DSC, and the heat of crystallization was 25.3 J / g. Therefore, the product of IEC and heat of crystallization was 48.1.

[0288] [Comparative Example 23] Synthesis of the ionic group oligomer a36 represented by the above general formula (G5) Ionic oligomer a36 (terminus: OM group) was obtained in the same manner as in Comparative Example 21, except that the amount of disodium-3,3'-disulfonate-4,4'-difluorobenzophenone used was changed to 40.1 g (95 mmol). The number-average molecular weight of this ionic oligomer a36 was 21,000.

[0289] <Synthesis of block copolymer b33> The block copolymer b33 contains the above oligomer a36 as an ionic segment and the above oligomer a31 as a nonionic segment.

[0290] Block copolymer b33 was obtained in the same manner as in Comparative Example 21, except that 21 g (1 mmol) of ionic oligomer a36 was added instead of ionic oligomer a32. The number-average molecular weight of this block copolymer b33 was 140,000 and the weight-average molecular weight was 350,000.

[0291] The IEC of the block copolymer b33 was 2.1 meq / g. The electrolyte membrane prepared using the block copolymer b33 showed a co-continuous-like phase separation structure (where hydrophilic domains containing ionic groups and hydrophobic domains not containing ionic groups form a continuous phase). Furthermore, a crystallization peak was observed by DSC, and the heat of crystallization was 16.0 J / g. Therefore, the product of the IEC and the heat of crystallization was 33.6.

[0292] [Comparative Example 24] <Synthesis of nonionic oligomer a35 represented by the following general formula (G14)> A 2,000 mL SUS polymerization apparatus equipped with a stirrer, nitrogen inlet tube, and Dean-Stark trap contained 16.59 g of potassium carbonate (Aldrich reagent, 120 mmol), 25.8 g (100 mmol) of K-DHBP obtained in Synthesis Example 1, and 20.3 g of 4,4'-difluorobenzophenone (Aldrich reagent, 93 mmol). After purging the apparatus with nitrogen, 300 mL of NMP and 100 mL of toluene were added. Dehydration was performed at 160°C, followed by heating to remove the toluene, and polymerization was carried out at 180°C for 1 hour. Purification was performed by reprecipitation with a large amount of methanol to obtain the terminal hydroxyl group of the nonionic oligomer a35. The number-average molecular weight of the terminal hydroxyl group of this nonionic oligomer a35 was 10,000.

[0293] In a 500 mL three-necked flask equipped with a stirrer, nitrogen inlet tube, and Dean-Stark trap, 1.1 g of potassium carbonate (Aldrich reagent, 8 mmol) and 20.0 g (2 mmol) of the terminal hydroxyl form of nonionic oligomer a35 were added. After purging the apparatus with nitrogen, 100 mL of NMP and 30 mL of cyclohexane were added, and the mixture was dehydrated at 100 °C. The temperature was then raised to remove the cyclohexane, and 3.0 g of bis(4-fluorophenylsulfone) (Aldrich reagent, 12 mmol) was added. The reaction was carried out at 105 °C for 1 hour. Purification was performed by reprecipitation with a large amount of isopropyl alcohol to obtain the nonionic oligomer a35 (terminal fluoro group) represented by the following general formula (G14). The number-average molecular weight of this nonionic oligomer a35 was 11,000. In general formula (G14), m represents an integer of 1 or more.

[0294] [ka]

[0295] <Synthesis of ionic group oligomer a38 represented by the above general formula (G5)> A 2,000 mL SUS polymerization apparatus equipped with a stirrer, nitrogen inlet tube, and Dean-Stark trap contained 27.6 g of potassium carbonate (Aldrich reagent, 200 mmol), 12.9 g (50 mmol) of K-DHBP obtained in Synthesis Example 1, 9.3 g of 4,4'-biphenol (Aldrich reagent, 50 mmol), 40.1 g (95 mmol) of disodium-3,3'-disulfonate-4,4'-difluorobenzophenone obtained in Synthesis Example 2, and 17.9 g of 18-crown-6 (Wako Pure Chemical Industries, 82 mmol). After purging the apparatus with nitrogen, 300 mL of NMP and 100 mL of toluene were added. Dehydration was carried out at 1170 °C, followed by heating to remove toluene, and polymerization was carried out at 180 °C for 1 hour. Purification was performed by reprecipitation with a large amount of isopropyl alcohol to obtain the ionic oligomer a38 (terminus: OM group) represented by the above general formula (G5). The number-average molecular weight of this ionic oligomer a38 was 21,000.

[0296] <Synthesis of block copolymer b34> The block copolymer b34 contains the above oligomer a38 as an ionic segment and the above oligomer a35 as a nonionic segment.

[0297] In a 500 mL three-necked flask equipped with a stirrer, nitrogen inlet tube, and Dean-Stark trap, 0.56 g of potassium carbonate (Aldrich reagent, 4 mmol) and 21 g (1 mmol) of ionic oligomer a38 were added. After purging the apparatus with nitrogen, 100 mL of NMP and 30 mL of cyclohexane were added, and the mixture was dehydrated at 100 °C. The temperature was then raised to remove the cyclohexane, and 11 g (1 mmol) of nonionic oligomer a35 was added. The reaction was carried out at 105 °C for 24 hours. The mixture was purified by reprecipitation with a large amount of isopropyl alcohol to obtain block copolymer b34. The number-average molecular weight of this block copolymer b34 was 140,000, and the weight-average molecular weight was 320,000.

[0298] The IEC of the block copolymer b34 was 2.2 meq / g. The electrolyte membrane prepared using the block copolymer b34 showed a lamellar phase separation structure. Furthermore, a crystallization peak was observed by DSC, and the heat of crystallization was 12.5 J / g. Therefore, the product of the IEC and the heat of crystallization was 27.5.

[0299] [Comparative Example 25] (Synthesis of nonionic oligomer a37 represented by the following general formula (G15)) In a 500 mL three-necked flask equipped with a stirrer, nitrogen inlet tube, and Dean-Stark trap, 13.82 g of potassium carbonate (Aldrich reagent, 100 mmol), 20.66 g (80 mmol) of K-DHBP obtained in Synthesis Example 1, and 20.95 g of 4,4'-difluorobenzophenone (Aldrich reagent, 96 mmol) were added. After purging the apparatus with nitrogen, 90 mL of NMP and 45 mL of toluene were added, and dehydration was carried out at 180 °C. The temperature was then raised to remove the toluene, and polymerization was carried out at 210 °C for 1 hour. Purification was performed by reprecipitation with a large amount of water, and washing with hot methanol to obtain the nonionic oligomer a37 represented by the following general formula (G15). The number-average molecular weight of this nonionic oligomer a37 was 3,000. In general formula (G15), N3 represents an integer of 1 or more.

[0300] [ka]

[0301] (Synthesis of block copolymer b35) In a 500 mL three-necked flask equipped with a stirrer, nitrogen inlet tube, and Dean-Stark trap, 8.29 g of potassium carbonate (Aldrich reagent, 60 mmol), 8.94 g of 4,4'-biphenol (Aldrich reagent, 48 mmol), and 16.89 g (40 mmol) of disodium-3,3'-disulfonate-4,4'-difluorobenzophenone obtained in Synthesis Example 2 were added. After purging the apparatus with nitrogen, 90 mL of NMP and 45 mL of toluene were added, and dehydration was carried out at 180 °C. The temperature was then raised to remove the toluene, and polymerization was carried out at 210 °C for 1 hour to obtain ionic oligomer a40. The number-average molecular weight of this ionic oligomer a40 was 4,000.

[0302] Next, 17.46 g (40 mmol) of nonionic oligomer a37 and 20 mL of toluene were added, and the mixture was dehydrated again at 180°C. After raising the temperature to remove the toluene, polymerization was carried out at 230°C for 8 hours to obtain block copolymer b35. The number-average molecular weight of this block copolymer b35 was 110,000, and the weight-average molecular weight was 271,000.

[0303] The IEC of the block copolymer b35 was 2.1 meq / g. The electrolyte membrane prepared using the block copolymer b35 showed a sea-island-like phase separation structure. Furthermore, a crystallization peak was observed by DSC, and the heat of crystallization was 11.1 J / g. Therefore, the product of the IEC and the heat of crystallization was 23.3.

[0304] [Comparative Example 26] <Block copolymer b36> The aforementioned block copolymer b8 was used as block copolymer b36. No crystallization peak was observed in block copolymer b36 by DSC. Therefore, the product of IEC and the heat of crystallization could not be calculated.

[0305] [Measurement results] Table 3 shows the measurement results of the electrolyte materials obtained in Examples 21-27 and Comparative Examples 21-26.

[0306] [Table 3]

[0307] In Examples 21-27, an electrolyte material (II) was used in which the IEC was between 1.8 meq / g and 3.0 meq / g, and the product of the IEC and the heat of crystallization (J / g) was between 35.0 and 47.0. As a result, the dimensional change rate in dry and wet conditions was small, and the proton conductivity was high at both low and high humidity levels. In other words, mechanical durability and proton conductivity were achieved at a relatively high level.

[0308] On the other hand, in Comparative Examples 21 to 26, either the IEC or the product of the IEC and the heat of crystallization (J / g) falls outside the above range, resulting in inferior dry-wet dimensional change rate or proton conductivity. In other words, mechanical durability and proton conductivity are not compatible.

[0309] In the present invention, from the viewpoint of achieving a relatively high level of both mechanical durability and proton conductivity, it is preferable that the dry-wet dimensional change rate is 7.0% or less, the low-humidified proton conductivity is 0.85 mS / cm or more, and the high-humidified proton conductivity is 9.00 mS / cm or more; it is more preferable that the dry-wet dimensional change rate is 6.5% or less, the low-humidified proton conductivity is 0.90 mS / cm or more, and the high-humidified proton conductivity is 9.50 mS / cm or more; it is even more preferable that the dry-wet dimensional change rate is 6.0% or less, the low-humidified proton conductivity is 1.00 mS / cm or more, and the high-humidified proton conductivity is 11.00 mS / cm or more; and it is particularly preferable that the dry-wet dimensional change rate is 5.7% or less, the low-humidified proton conductivity is 1.10 mS / cm or more, and the high-humidified proton conductivity is 13.00 mS / cm or more. [Explanation of symbols]

[0310] 1 phase 1 2 phase 2

Claims

1. A polymer electrolyte material comprising a block copolymer having segments containing ionic groups (hereinafter referred to as "ionic segments") and segments not containing ionic groups (hereinafter referred to as "nonionic segments"), wherein the polymer electrolyte material has a phase separation structure. The block copolymer is formed by alternately introducing the ionic segments and the nonionic segments. Both the ionic segment and the nonionic segment are aromatic polyether ketone polymers. A polymer electrolyte material in which, when the number average molecular weight of the ionic segment is Mn1 and the number average molecular weight of the nonionic segment is Mn2, Mn2 is 15,000 or more, satisfies the following formula 1, and satisfies at least one of the following conditions 1 and 2. 1.7≦Mn1 / Mn2≦7.0 (Formula 1) <Condition 1> The degree of saturation crystallinity of the polymer electrolyte material, as measured by wide-angle X-ray diffraction, is 5% or more and 30% or less. <Condition 2> The ion exchange capacity (IEC) of the polymer electrolyte material is 1.8 meq / g or more and 3.0 meq / g or less, and the product of the IEC (meq / g) of the polymer electrolyte material and the heat of crystallization of the polymer electrolyte material (J / g) measured by differential scanning calorimetry is 35.0 or more and 47.0 or less.

2. The polymer electrolyte material according to claim 1, wherein the polymer electrolyte material has a cocontinuous or lamellar phase separation structure.

3. The polymer electrolyte material according to claim 1 or 2, wherein the average period size of the phase separation structure is 15 to 100 nm.

4. The polymer electrolyte material according to any one of claims 1 to 3, wherein the block copolymer has a linker portion that connects the ionic segment and the nonionic segment.

5. The polymer electrolyte material according to any one of claims 1 to 4, wherein the ionic segment contains a structure represented by the following general formula (S1), and the nonionic segment contains a structure represented by the following general formula (S3). 【Chemistry 1】 (In general formula (S1), Ar1 to Ar4 each independently represent a substituted or unsubstituted arylene group, and at least one of Ar1 to Ar4 has an ionic group. Y1 and Y2 each independently represent a ketone group and a protecting group that can be converted to a ketone group. * represents a bond with general formula (S1) or other constituent units.) 【Chemistry 2】 (In general formula (S3), Ar ５ ~Ar ８ Each of these independently represents a substituted or unsubstituted arylene group. However, Ar ５ ~Ar ８ None of them have ionic groups. ３ and Y ４ These symbols independently represent a ketone group and a protecting group that can be converted to a ketone group. * represents a bond with the general formula (S3) or other constituent units.

6. The polymer electrolyte material according to claim 5, wherein the structure represented by the general formula (S3) is the structure represented by the following general formula (S4). 【Transformation 3】 (In general formula (S4), Y ３ and Y ４ Each of these independently represents a ketone group or a protecting group that can be converted to a ketone group. * represents a bond with the general formula (S4) or other constituent units.

7. A polymer electrolyte molded article comprising the polymer electrolyte material according to any one of claims 1 to 6.

8. An electrolyte membrane with a catalyst layer, constructed using the polymer electrolyte molded body described in claim 7.

9. A membrane electrode assembly constructed using the polymer electrolyte molded body described in claim 7.

10. A solid polymer fuel cell comprising a polymer electrolyte molded body as described in claim 7.

11. A water electrolysis type hydrogen generator configured using the polymer electrolyte molded body described in claim 7.

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