Block copolymer for polymer electrolyte materials and its manufacturing method, polymer electrolyte material, polymer electrolyte molded body, polymer electrolyte membrane, electrolyte membrane with catalyst layer, membrane electrode composite, solid polymer fuel cell, and water electrolysis hydrogen generator.

Abstract

To provide a block copolymer which can achieve high proton conductivity under low humidification condition, excellent mechanical strength and chemical stability, and improvement of processability, and a polyelectrolyte material using the same.SOLUTION: A block copolymer has each of one or more segments containing ionic groups (hereinafter referred to as "ionic segment"), and segments containing no ionic group (hereinafter referred to as "non-ionic segment"), wherein at least one of the ionic segment and the non-ionic segment has a constitutional unit (hereinafter referred to as "constitutional unit ") composed of an aromatic hydrocarbon-based polymer, and a first linker connecting between the constitutional units.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to block copolymers, methods for producing the same, polymer electrolyte materials, polymer electrolyte molded bodies, polymer electrolyte membranes, electrolyte membranes with catalyst layers, membrane electrode composites, solid polymer fuel cells, and water electrolysis type hydrogen generators using block copolymers. [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 a cell unit in which a membrane electrode assembly (MEA) is 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 by an electrochemical reaction when a hydrogen-containing fuel gas comes into contact with the anode electrode and air comes into contact with 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 been actively pursued. Hydrocarbon-based electrolyte materials are excellent in low gas permeability and heat resistance, and electrolyte materials using aromatic polyether ketones and aromatic polyether sulfones have been particularly actively studied.

[0005] Among them, as a hydrocarbon-based polymer electrolyte material that has excellent proton conductivity even under low-humidity conditions and also has excellent mechanical strength and chemical stability, a block copolymer in which a segment containing an ionic group (hereinafter, "containing an ionic group" is referred to as "ionic") and a segment not containing an ionic group (hereinafter, "not containing an ionic group" is referred to as "non-ionic") are linked by a linker has been proposed (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] However, even when using the block copolymers described in Patent Documents 1 and 2, the effects of improving proton conductivity, mechanical strength, and chemical stability under low-humidity conditions are not complete, and further improvement has been desired for the block copolymers and the polymer electrolyte materials using them.

[0008] In view of the background of the prior art, the present invention aims to realize a block copolymer and a polymer electrolyte material using the same that have excellent proton conductivity even under low humidity conditions, as well as excellent mechanical strength and physical durability. [Means for solving the problem]

[0009] The inventors of the present invention believe that the reason the prior art had the above problems was that segments in block copolymers were synthesized to the desired number-average molecular weight solely by monomer copolymerization. They then discovered that by using polymers with a number-average molecular weight smaller than the desired number-average molecular weight as the constituent units of the segments, and linking the constituent units with a highly reactive linker, precise control to the desired number-average molecular weight becomes easy, the processability is excellent, and it is also possible to increase the molecular weight of the segments.

[0010] To solve the above problems, the block copolymer of the present invention has the following configuration. That is, A block copolymer having one or more segments containing ionic groups (hereinafter referred to as "ionic segments") and one or more segments not containing ionic groups (hereinafter referred to as "nonionic segments"), wherein the ionic segments and the nonionic segments The ionic segment and the nonionic segment include an aromatic hydrocarbon polymer. At least one of the components comprises a constituent unit made of an aromatic hydrocarbon polymer (hereinafter referred to as "constituent unit") and a first linker connecting the constituent units. death, The first linker has a structure represented by any of the following general formulas (M1) to (M8), The segment having the aforementioned structural unit and the first linker has a structure represented by the following general formula (C1). Block copolymer. [ka] (In general formulas (M1) to (M4), W to Z are independently H and NO.) 2 CN, CF 3 In general formula (M6), R represents a group selected from the group consisting of F, Cl, Br, and I. r1 to r4 each independently represent integers from 1 to 4. In general formula (M6), R represents any organic group; in general formula (M7), Ar represents any arylene group; and in general formula (M8), E represents an oxygen atom or a sulfur atom. General formulas (M1) to (M8) may be further substituted with electron-withdrawing groups. * represents a bonding site between general formulas (M1) to (M8) and the constituent unit. [ka] In general formula (C1), A is a constituent unit, X is a structure represented by general formula (C2), and n is an integer greater than or equal to 1. In general formula (C2), A is a constituent unit, L1 is the first linker, and m is an integer greater than or equal to 1. If n is 2 or greater, multiple m values ​​may be the same or different from each other.

[0011] The method for producing block copolymers of the present invention has the following configuration: A method for producing the block copolymer, comprising at least a step (1) of reacting a compound that provides the constituent units with a compound that provides the first linker.

[0012] The polymer electrolyte material of the present invention has the following configuration: This is a polymer electrolyte material containing the block copolymer described above.

[0013] The polymer electrolyte molded body of the present invention has the following configuration: This is a polymer electrolyte molded body containing the above-mentioned polymer electrolyte material.

[0014] The polymer electrolyte membrane of the present invention has the following configuration: This is a polymer electrolyte membrane made using the above-mentioned polymer electrolyte material.

[0015] The catalyst-layered electrolyte membrane of the present invention has the following configuration: This is an electrolyte membrane with a catalyst layer, constructed using the above-mentioned polymer electrolyte material.

[0016] The membrane electrode composite of the present invention has the following configuration: This is a membrane electrode composite constructed using the above-mentioned polymer electrolyte material.

[0017] The present invention has the following configuration: This is a solid polymer fuel cell constructed using the above-mentioned polymer electrolyte material.

[0018] The water electrolysis hydrogen generator of the present invention has the following configuration: This is a water electrolysis type hydrogen generator constructed using the above-mentioned polymer electrolyte material.

[0019] In the block copolymer of the present invention, it is preferable that the ionic segment comprises the constituent units and a first linker connecting the constituent units.

[0020] The block copolymer of the present invention is characterized in that the first linker is represented by any of the following general formulas (M1) to (M8). ru.

[0021] [ka]

[0022] (In general formulas (M1) to (M4), W to Z each independently represent a group selected from the group consisting of H, NO2, CN, CF3, F, Cl, Br, and I; r1 to r4 each independently represent an integer from 1 to 4; in general formula (M6), R represents any organic group; in general formula (M7), Ar represents any arylene group; and in general formula (M8), E represents an oxygen atom or a sulfur atom. General formulas (M1) to (M8) may be further substituted with electron-withdrawing groups. * represents a bonding site between general formulas (M1) to (M8) and the constituent unit.) The block copolymer of the present invention preferably has alternating ionic segments and nonionic segments.

[0023] In the present invention, it is preferable that the block copolymer has a second linker region that connects the ionic segment and the nonionic segment.

[0024] In the block copolymer of the present invention, it is preferable that the ionic segment contains an aromatic polyether structure.

[0025] In the block copolymer of the present invention, it is preferable that the ionic segment contains an aromatic polyetherketone structure.

[0026] The block copolymer of the present invention preferably contains an ionic segment with a structure represented by the following general formula (S1).

[0027] [Chemical formula]

[0028] (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 another structure.) The block copolymer of the present invention preferably has a structure represented by the general formula (S1) being a structure represented by the following general formula (S2).

[0029] [Chemical formula]

[0030] (In the general formula (S2), Y 1 and Y 2 each independently represents a ketone group or a protecting group that can be derived from a ketone group. M 1 ~M 4 each independently represents a hydrogen atom, a metal cation or an ammonium cation. n1 to n4 are each independently 0 or 1, and at least one of n1 to n4 is 1. * represents a bond with the general formula (S2) or another structure.) The block copolymer of the present invention preferably has the non-ionic segment containing an aromatic polyether structure.

[0031] The block copolymer of the present invention preferably has the non-ionic segment containing an aromatic polyether ketone structure.

[0032] The block copolymer of the present invention preferably contains a structure represented by the following general formula (S3) in the non-ionic segment.

[0033] [ka]

[0034] (In general formula (S3), Ar 5 ~Ar 8 Each of these independently represents an arylene group. However, Ar 5 ~Ar 8 None of them have ionic groups. 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 (S3) or another structure. In the block copolymer 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).

[0035] [ka]

[0036] (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 another structure. The block copolymer of the present invention preferably has a co-continuous phase separation structure.

[0037] The method for producing a block copolymer of the present invention preferably includes, after step (1), step (2), a step in which the compound obtained in step (1) is reacted with a compound that gives the other segment.

[0038] The method for producing a block copolymer of the present invention preferably includes a step (1') prior to step (2) in which a compound that gives an ionic segment and a compound that gives a nonionic segment are reacted with a compound that gives a second linker to introduce a second linker to both ends of the compound that gives an ionic segment.

[0039] In the method for producing the block copolymer of the present invention, it is preferable that the compound giving the first linker and the second linker is represented by any of the following general formulas (N1) to (N8).

[0040] [ka]

[0041] (In general formulas (N1) to (N8), V represents Cl or F. In general formulas (N1) to (N4), W to Z each independently represent a group selected from the group consisting of H, NO2, CN, CF3, F, Cl, Br, and I; r1 to r4 each independently represent an integer from 1 to 4; in general formula (N6), R represents any organic group; in general formula (N7), Ar represents any arylene group; and in general formula (N8), E represents an oxygen atom or a sulfur atom. General formulas (N1) to (N8) may be further substituted with electron-withdrawing groups.) [Effects of the Invention]

[0042] The block copolymer of the present invention exhibits excellent processability as a polymer electrolyte material, possesses good physical durability, and can demonstrate high proton conductivity, including under low humidity conditions. [Modes for carrying out the invention]

[0043] 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.

[0044] (Block copolymer) The block copolymer of the present invention is a block copolymer having one or more ionic segments and one or more nonionic segments.

[0045] In the present invention, a segment is a partial structure within a block copolymer of a macromonomer used in the synthesis of the block copolymer. The block copolymer of the present invention contains both ionic and nonionic segments. In the present invention, although referred to as a nonionic segment, such a segment may contain a small amount of ionic groups as long as it does not adversely affect the effects of the present invention. Hereinafter, "nonionic, without ionic groups" may be used interchangeably.

[0046] The block copolymer of the present invention is formed by linking two or more mutually immiscible segment chains, namely hydrophilic segments containing ionic groups and hydrophobic segments not containing ionic groups, 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 micro domains 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 micro phase separation structure. Here, a domain refers to a cluster formed by the aggregation of similar segments in one or more polymer chains. For ionic conduction in polymer electrolyte membranes, the spatial arrangement of ion-conducting segments in the membrane, i.e., the nano or micro phase separation structure, is important.

[0047] By appropriately adjusting the molecular chain length of the segments, i.e., the molecular weight of the segments, the cohesiveness of each segment when forming a phase separation structure is increased. When the molecular chain length of ionic segments is increased, the structure of the ionic domains becomes larger, improving proton conductivity under low humidity conditions. When the molecular chain length of nonionic segments is increased, the structure of the nonionic domains becomes larger, improving mechanical strength, dimensional change rate, and mechanical durability.

[0048] The block copolymer of the present invention has at least one of an ionic segment and a nonionic segment comprising a constituent unit (hereinafter referred to as "constituent unit") made of an aromatic hydrocarbon polymer and a first linker connecting the constituent units. In the present invention, a constituent unit refers to the polymer that constitutes the segment.

[0049] In the present invention, the first linker is defined as a structure contained within a segment, which connects the constituent units that make up the segment, and which has a different chemical structure from the constituent units. The constituent units connected by the first linker may be the same constituent unit or a combination of multiple different constituent units.

[0050] The block copolymer of the present invention may contain the first linker in only one of the ionic segment and the nonionic segment, or it may contain the first linker in both the ionic segment and the nonionic segment.

[0051] The first linker links the constituent units while suppressing randomization of oligomers, molecular chain severance, terminal deactivation, and other side reactions that may occur during copolymer synthesis. By linking the constituent units within a segment with linkers, the number-average molecular weight of the segment can be easily and precisely adjusted to the desired number-average molecular weight.

[0052] In conventional synthesis methods that synthesize segments solely by monomer copolymerization, the number-average molecular weight of the resulting segments can vary significantly from the target number-average molecular weight. Furthermore, the larger the target number-average molecular weight, the greater the range of variation tends to be. Possible contributing factors include slight differences in the purity and water content of the monomers, solvents, and catalysts used in the synthesis, as well as environmental conditions in the reaction system, stirring efficiency, and reaction temperature. Eliminating all of these factors is practically impossible. In short, conventional synthesis methods result in variations in the number-average molecular weight of segments between batches, making it difficult to consistently obtain the target number-average molecular weight.

[0053] If the number-average molecular weight of a segment is smaller or larger than the desired number-average molecular weight, the block copolymer synthesized using the compound that gives these segments may have decreased number-average and weight-average molecular weight. This is presumed to be because the terminal ratio of the segment-giving compound fell outside the appropriate range during the synthesis of the block copolymer. As a result, the mechanical strength (e.g., tensile strength and elongation) of the resulting block copolymer may decrease.

[0054] From the above perspective, precise molecular weight control of segments is important for the production of block copolymers, and this molecular weight control is made possible by linking the constituent units within the segments with linkers. That is, the block copolymer of the present invention, in which at least one of the ionic segments and nonionic segments is linked by linkers between its constituent units, has good and stable mechanical strength. Furthermore, it is preferable that at least the ionic segments are linked by linkers between their constituent units.

[0055] Furthermore, by linking the constituent units of the segments with linkers, it becomes possible to synthesize high-molecular-weight segments.

[0056] For example, if a polymer with a number-average molecular weight of 30,000 is used as a constituent unit and linked by a first linker, a segment with a number-average molecular weight of 60,000 will be formed as a dimer, and a segment with a number-average molecular weight of 90,000 will be formed as a trimer. However, it is not necessary to link all the constituent units of the segment with a linker; it is also possible to use a polymer with a number-average molecular weight of 30,000 as a constituent unit and link only some of the constituent units with a first linker to adjust the segment to have a number-average molecular weight of 45,000. In this case, the block copolymer will contain both a dimer with a structure containing the first linker and a monomer with a structure without the first linker as segments, resulting in non-uniform molecular chain lengths of the segments. Therefore, it is preferable to link all the constituent units with a first linker.

[0057] When an ionic segment has a first linker that connects the constituent units, the constituent units may be either ionic or nonionic. However, at least one constituent unit in the ionic segment is ionic. From the viewpoint of increasing the density of ionic groups, it is preferable that all constituent units of the ionic segment are ionic.

[0058] If a nonionic segment has a first linker that connects its constituent units, then all constituent units of the nonionic segment are nonionic.

[0059] Compared to nonionic polymers, ionic polymers have lower polymerizability, making it difficult to achieve high molecular weights or control molecular weights. Therefore, it is preferable that at least the ionic segment has a first linker that connects the constituent units. While it was difficult to obtain ionic segments with a number-average molecular weight of 60,000 or more using conventional synthesis methods, it has become possible to easily and stably synthesize them by linking the constituent units with a linker.

[0060] In this invention, the number-average molecular weight and weight-average molecular weight are defined as standard polystyrene equivalent values ​​measured using gel permeation chromatography (GPC), as described in the examples below.

[0061] A segment used in the present invention, having a constituent unit and a first linker connecting the constituent units, can be expressed as follows, using the general formula (C1), where the constituent unit is denoted as (A) and the first linker as (L1).

[0062] [ka]

[0063] In general formula (C1), X is a structure represented by general formula (C2), and n is an integer greater than or equal to 1. In general formula (C2), m is an integer greater than or equal to 1. If n is 2 or greater, multiple m values ​​may be the same or different. If m is 2 or greater, it indicates that two or more -A- structures are linked to L1. That is, it indicates that the segment has a branched structure.

[0064] To obtain the above segments, the compound that forms the first linker site must be a highly reactive compound that can link the constituent units while suppressing randomization of the copolymer and segment cleavage. Therefore, (L1) has a structure such as the following general formulas (M1) to (M8). ru.

[0065] [ka]

[0066] In general formulas (M1) to (M4), W to Z each independently represent a group selected from the group consisting of H, NO2, CN, CF3, F, Cl, Br, and I; r1 to r4 each independently represent an integer from 1 to 4; in general formula (M6), R represents any organic group; in general formula (M7), Ar represents any arylene group; and in general formula (M8), E represents an oxygen atom or a sulfur atom. General formulas (M1) to (M8) may be further substituted with electron-withdrawing groups. * represents a bonding site between general formulas (M1) to (M8) and constituent unit A.

[0067] As the compound that gives (L1) as described above (hereinafter referred to as the "linker compound"), at least one selected from the following general formulas (N1) to (N12) is preferred, but is not limited to these. In the present invention, the linker compound is a dihalide compound or a multihalide compound that becomes the linker site after the reaction. A multihalide compound is a compound that has three or more halides as substituents. When a linear segment is to be obtained, it is preferable to use a dihalide compound as the linker, and when a branched structure is to be formed in the segment, it is preferable to use a multihalide compound as the linker. A combination of a dihalide compound and a multihalide compound may also be used.

[0068] [ka]

[0069] In general formulas (N1) to (N8), V represents either Cl or F. W to Z, r1 to r4, R, Ar, and E are the same as those in general formulas (M1) to (M8).

[0070] Specific examples of linker compounds that satisfy (N1) include 1,2-difluorobenzene, 1,3-difluorobenzene, 1,4-difluorobenzene, 2,4-difluorobenzonitrile, 1,2,4-trifluorobenzene, 1,3,5-trifluorobenzene, 1,2,3,4-tetrafluorobenzene, 1-chloro-2,4,5-trifluorobenzene, 2,4,5-trifluorobenzonitrile, 1,2,4-trifluoro-5-nitrobenzene, 1,2,4-trifluoro-5-(trifluoromethyl)benzene, hexafluorobenzene, Examples include 1-chloro-2,3,4,5,6-pentafluorobenzene, 2,3,4,5,6-pentafluorobenzonitrile, 1,2,3,4,5-pentafluoro6-(trifluoromethyl)benzene, 2,3,5,6-tetrafluoroterephthalonitrile, 2,4,5,6-tetrafluoroisophthalonitrile, 2,3,5-trifluoroisophthalonitrile, 2,4,6-trifluoroisophthalonitrile, 1,2,3,4,5-pentafluoro-6-(trifluoromethyl)benzene, and 1,2,3,4,5-pentafluoro-6-nitrobenzene.

[0071] For example, compounds that satisfy (N2) include 2,2'-dichloro-1,1'-biphenyl, 4,4'-dichloro-1,1'-biphenyl, 2,2'-difluoro-1,1'-biphenyl, 4,4'-difluoro-1,1'-biphenyl, decafluorobiphenyl, 2,2',3,3',4,4',6,6'-octafluoro-5,5'-dinitro-1,1'-biphenyl, and 2,2',3,3',4,4',5,6,6'-nonafluoro-5'-nitro-1,1'-biphenyl.

[0072] For example, compounds that satisfy (N3) include 4,4'-difluorodiphenylsulfone, 4,4'-dichlorodiphenylsulfone, 5,5'-sulfonylbis(2-fluorobenzonitrile), 4,4'-sulfonylbis(1-fluoro-2-nitrobenzene), 4,4'-sulfonylbis(1-fluoro-2-(trifluoromethyl)benzene), and 2-fluoro-5-((4-fluoro-3-(trifluoromethyl)phenyl)sulfonyl)benzonitrile.

[0073] For example, compounds that satisfy (N4) include bis(4-fluorophenyl)ketone, 5,5'-carbonylbis(2-fluorobenzonitrile), bis(4-fluoro-3-(trifluoromethyl)phenyl)ketone, and bis(4-fluoro-3-nitrophenyl).

[0074] For example, compounds that satisfy (N5) include 2,6-difluoropyridine and 2,6-dichloropyridine.

[0075] For example, compounds that satisfy (N6) include 2,4-difluoro-6-methoxy-1,3,5-triazine and 2,4-dichloro-6-methoxy-1,3,5-triazine.

[0076] For example, compounds that satisfy (N7) include 1,4-bis(6-fluoroquinoxalin-2-yl)benzene and 1,4-bis(6-chloroquinoxalin-2-yl)benzene.

[0077] For example, compounds that satisfy (N8) include 3,4-bis(4-fluorophenyl)-1,2,5-oxadiazole and 3,4-bis(4-fluorophenyl)-1,2,5-thiadiazole.

[0078] The block copolymer of the present invention contains a structural unit having an aromatic hydrocarbon polymer in at least one of its ionic segment and nonionic segment. Hydrocarbon means anything other than perfluoro polymers, and aromatic hydrocarbon polymer is a polymer other than perfluoro polymers that is mainly composed of aromatic rings.

[0079] In the present invention, the aromatic rings contained in the aromatic hydrocarbon polymer may include not only hydrocarbon aromatic rings but also heterocycles. Furthermore, some aliphatic units may constitute the polymer together 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 together with aromatic rings. Among these, aromatic polyether polymers are preferred from the viewpoint of cost and polymerizability.

[0080] Aromatic polyether polymers are polymers mainly composed of aromatic rings in which at least ether bonds are included in the repeating units as a way in which aromatic ring units are linked. Examples of aromatic polyether polymer structures include, but are not limited to, aromatic polyethers, aromatic polyether ketones, aromatic polyether ether ketones, aromatic polyether ketone ketones, aromatic polyether ether ketone ketones, aromatic polyether ketone ether ketone ketones, aromatic polyether imide, and aromatic polyether sulfone. From the viewpoint of chemical stability and cost, aromatic polyether ketone polymers and polyether sulfone polymers are preferred, and from the viewpoint of mechanical strength, dimensional stability, and physical durability, aromatic polyether ketone polymers are most preferred.

[0081] Aromatic polyetherketone polymers are polymers primarily composed of aromatic rings, in which the repeating units contain at least ether bonds and ketone bonds as a way in which the aromatic ring units are linked.

[0082] Aromatic polyethersulfone polymers are polymers primarily composed of aromatic rings, in which the aromatic ring units are linked in a manner that includes at least ether bonds and sulfone bonds.

[0083] The block copolymer of the present invention preferably has alternating ionic and nonionic segments. By having these segments alternately, a block copolymer with excellent low humidification proton conductivity is obtained, with a precisely controlled phase separation structure and domain size. Here, "alternating" means that a second linker moiety, as described later, may be present between the ionic and nonionic segments.

[0084] The block copolymer of the present invention preferably contains one or more second linker (L2) sites that connect the ionic segment and the nonionic segment. In the present invention, the second linker is defined as a site that connects the ionic segment and the nonionic segment and has a chemical structure different from that of the ionic segment or the nonionic segment.

[0085] The second linker may have the same structure as the first linker described above, or it may have a different structure. This second linker links different segments while suppressing randomization of the copolymer by ether exchange reactions, segment cleavage, and other side reactions that may occur during copolymer synthesis. Therefore, by using a compound that gives such a second linker as a raw material, a block copolymer can be obtained without reducing the molecular weight of each segment.

[0086] Suitable specific examples of the second linker include decafluorobiphenyl, hexafluorobenzene, 4,4'-difluorodiphenylsulfone, and 2,6-difluorobenzonitrile, but the present invention is not limited to these.

[0087] (Ionic segment) In the block copolymer of the present invention, from the viewpoint of cost and polymerizability, it is preferable that the ionic segment contains an aromatic polyether structure, and from the viewpoint of mechanical strength, dimensional stability, and physical durability, it is most preferable that it contains an aromatic polyetherketone structure. An aromatic polyether structure is mainly composed of aromatic rings, and the repeating unit contains at least an ether bond as a way in which the aromatic ring units are linked. An aromatic polyetherketone structure is mainly composed of aromatic rings, and the repeating unit contains at least an ether bond and a ketone bond as a way in which the aromatic ring units are linked.

[0088] In the block copolymer of the present invention, it is preferable that the ionic segment contains a structure represented by the following general formula (S1) from the viewpoint of dimensional stability, mechanical strength, and chemical stability.

[0089] [ka]

[0090] In general formula (S1), Ar 1 ~Ar 4 Each of these independently represents a substituted or unsubstituted arylene group, and Ar 1 ~Ar 4 At least one of them has an ionic group. 1 and Y 2 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 (S1) or other structures.

[0091] Furthermore, the ionic segment may include structures other than those represented by the general formula (S1).

[0092] Here, Ar 1 ~Ar 4 Preferred aromatic rings 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.

[0093] The ionic groups used in the block copolymer of the present invention are preferably negatively charged atomic groups, and preferably those having proton exchange ability. Suitable functional groups include sulfonic acid groups, sulfonimide groups, sulfate groups, phosphonic acid groups, phosphoric acid groups, and carboxylic acid groups, as shown below.

[0094] [ka]

[0095] Such ionic groups include cases where the functional groups (f1) to (f7) are salts. Examples of cations that form such salts include any metal cation, NR4 + Examples include (where R is any organic group). There are no particular restrictions on the metal cation, but Na, K, and Li are preferred because they are inexpensive and can be easily proton-substituted.

[0096] Two or more of these ionic groups can be included in the block copolymer, and the combination is determined appropriately depending on the polymer structure and other factors. In particular, from the viewpoint of high proton conductivity, it is more preferable to have at least a sulfonic acid group, a sulfonimide group, and a sulfate group, and from the viewpoint of raw material cost, it is most preferable to have a sulfonic acid group.

[0097] As for the block copolymer of the present invention, it is preferable that the structure represented by general formula (S1) is the structure represented by the following general formula (P1) from the viewpoint of dimensional stability and raw material availability, and it is even more preferable that the structure represented by the following general formula (S2) is the structure represented by the following general formula from the viewpoint of raw material availability and polymerizability.

[0098] [ka]

[0099] In general formulas (P1) and (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.

[0100] 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.

[0101] The content of the ionic segment represented by the general formula (S1) is more preferably 20 mol% or more, even more preferably 50 mol% or more, and most preferably 80 mol% or more.

[0102] Examples of ionic monomers used to synthesize 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 for use in the ionic segments due to its chemical stability, manufacturing cost, and the ability to precisely control the amount of ionic groups. 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.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] [ka]

[0107] (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.

[0108] 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.

[0109] 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.

[0110] [ka]

[0111] (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 in particular, aromatic diphenol compounds having a protecting group, as described later, are preferred.

[0112] The monomers used to synthesize the constituent units of ionic segments have been described above.

[0113] When an ionic segment has the aforementioned constituent units and a first linker connecting the constituent units, it is preferable from the viewpoint of dimensional stability, mechanical strength, and chemical stability that the structures represented by general formulas (S1), (P1), and (S2) are included in the constituent units.

[0114] A preferred example of an ionic segment that may include structures other than the structure represented by general formula (S1) is an aromatic polyether ketone structure consisting of the structures represented by the following general formulas (T1) and (T2).

[0115] [ka]

[0116] 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.

[0117] 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).

[0118] Among these, ionic segments having a structure represented by general formula (P1) and structures represented by general formulas (T1) and (T2) are particularly preferred. In such ionic segments, when the amounts of the constituent units represented by general formulas (P1), (T1), and (T2) are p1, t1, and t2, respectively, with the total molar amount of t1 and t2 being 100 mole parts, it is preferable that p1 is 75 mole parts or more, more preferably 90 mole parts or more, and even more preferably 100 mole parts or more.

[0119] 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.

[0120] 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).

[0121] [ka]

[0122] 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).

[0123] (Nonionic segment) Regarding the block copolymer of the present invention, from the viewpoint of cost and polymerizability, it is preferable that the nonionic segment contains an aromatic polyether structure, and from the viewpoint of mechanical strength, dimensional stability, and physical durability, it is more preferable that it is an aromatic polyetherketone polymer. An aromatic polyether structure is one in which aromatic groups and ether bonds are contained as repeating unit structures. An aromatic polyetherketone structure is one that is mainly composed of aromatic rings, and in the repeating unit, at least ether bonds and ketone bonds are included as a way in which aromatic ring units are linked.

[0124] In the block copolymer of the present invention, it is preferable that the nonionic segment contains a structure represented by the following general formula (S3) from the viewpoint of dimensional stability, mechanical strength, and chemical stability.

[0125] [ka]

[0126] In general formula (S3), Ar 5 ~Ar 8 Each of these independently represents an arylene group. However, Ar 5 ~Ar 8 None of them have ionic groups. 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 (S3) or other structures.

[0127] Here, Ar 5 ~Ar 8 Preferred aromatic rings 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.

[0128] In the block copolymer of the present invention, it is preferable from the viewpoint of raw material availability that the nonionic segment contains a structure represented by the following formula (P2). In particular, it is even more preferable from the viewpoint of mechanical strength due to crystallinity, dimensional stability, and physical durability that the copolymer contains a constituent unit represented by the following formula (S4).

[0129] [ka]

[0130] 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 the general formulas (P2) and (S4) or other structures.

[0131] The content of the structure represented by general formula (S3) or (S4) in the nonionic segment is preferably more than 20 mol%, more preferably 50 mol% or more, and most preferably 80 mol% or more.

[0132] When a nonionic segment has the constituent units and a first linker connecting the constituent units, it is preferable from the viewpoint of dimensional stability, mechanical strength, and chemical stability that the structures represented by general formulas (S3), (P2), and (S4) are included in the constituent units. (Detailed description of block copolymer) The block copolymer of the present invention is preferably composed of an ionic segment containing the structure represented by the general formula (S1) and a block copolymer having a nonionic segment containing the structure represented by the general formula (S3).

[0133] A nonionic segment is a crystalline segment if it contains a structure represented by the general formula (S3). A block copolymer containing such a nonionic segment can be produced by molding a block copolymer precursor in which protecting groups have been introduced to at least the nonionic segment, and then deprotecting at least a portion of the protecting groups 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 protecting groups to at least the nonionic segment to improve processability, and it is also preferable to introduce protecting groups to the ionic segment if it results in poor processability.

[0134] Examples of such protecting groups include, preferably, those containing at least one selected from the following general formulas (P3) and (P4).

[0135] [ka]

[0136] (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, E represents O or S, and each may represent two or more different groups. The groups represented by formulas (P3) and (P4) may be substituted as desired. In particular, in terms of the odor, reactivity, and stability of the compound, the method in which E is O in the general formulas (P3) and (P4), that is, the method of protecting / deprotecting the ketone moiety with the ketal moiety, is the most preferred.

[0137] 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.

[0138] 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 14Both are p-phenylene groups.

[0139] 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.

[0140] 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.

[0141] 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.

[0142] 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.

[0143] 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.

[0144] Even when the aromatic polyether polymer contains bonding modes other than ether bonding, such as direct bonding, it is more preferable for the protective group to be introduced to be in the aromatic ether polymer portion, from the viewpoint of improving processability.

[0145] 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.

[0146] [ka]

[0147] (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 is any alkylene group, and E represents O or S. Compounds represented by general formulas (P3-1) and (P4-1) may be optionally substituted. The preferred protecting groups have been described above.

[0148] By controlling the number-average molecular weight of the ionic segments and / or nonionic segments constituting the block copolymer in the present invention, it is possible to adjust the average period size of the phase separation structure of the block copolymer, improve the dimensional change rate, and enhance mechanical durability. 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 expanding the average period size of the phase separation structure and improving proton conductivity. On the other hand, the number-average molecular weight of the nonionic 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 improving the dimensional change rate and mechanical durability.

[0149] By having the structure of the first linker in the present invention within the segment, it is possible to increase the molecular weight of the segment even when it is difficult to achieve the desired number-average molecular weight by monomer copolymerization reaction alone, and the molecular weight of the segment can be easily adjusted to the above preferred range of number-average molecular weight.

[0150] Furthermore, in the block copolymer 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 because the block copolymerization reaction proceeds appropriately, a high molecular weight block copolymer can be obtained, and a phase separation structure suitable for proton conduction can be formed. 1.7≦Mn1 / Mn2≦7.0 (Formula 1) 2.0≦Mn1 / Mn2≦5.0 (Equation 2).

[0151] In the block copolymer of the present invention, when the average molecular weight of the block copolymer is Mn3, it is preferable that the following formula 3 is satisfied, and more preferably that the following formula 4 is satisfied. Mn3 / (Mn1+Mn2)>1 (Equation 3) Mn3 / (Mn1+Mn2)≧1.2 (Equation 4).

[0152] When the relationship in Equation 3 is satisfied, a phase separation suitable for proton conductivity is easily formed in the polymer electrolyte material containing the block copolymer, and high proton conductivity is achieved under low humidity conditions.

[0153] The ion exchange capacity of the block copolymer of the present invention is preferably 0.1 to 5 meq / g, more preferably 1.5 meq / g or more, and most preferably 2 meq / g or more, from the viewpoint of balancing proton conductivity and water resistance. Furthermore, 3.5 meq / g or less is more preferable, and most preferably 3 meq / g or less.

[0154] The ion exchange capacity of the ionic segment is preferably high, more preferably 2.5 meq / g or higher, even more preferably 3 meq / g or higher, and most preferably 3.5 meq / g or higher, from the viewpoint of proton conductivity under low humidity conditions. Furthermore, 6.5 meq / g or less is more preferable, 5 meq / g or less is even more preferable, and most preferably 4.5 meq / g or less.

[0155] The ion exchange capacity of the nonionic segment is preferably low, more preferably 1 meq / g or less, even more preferably 0.5 meq / g, and most preferably 0.1 meq / g or less, from the viewpoint of hot water resistance, mechanical strength, dimensional stability, and physical durability.

[0156] Here, ion exchange capacity refers to the molar amount of ion exchange groups introduced per unit dry weight of a block copolymer, polymer electrolyte material, and polymer electrolyte membrane. Ion exchange capacity 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 it is difficult to measure when a sulfur source other than a sulfonic acid group is included. Therefore, in this invention, ion exchange capacity is defined as the value obtained by the neutralization titration method described later.

[0157] (Method of manufacturing block copolymers) The following are examples of methods for producing the block copolymer of the present invention, but the present invention is not limited to these.

[0158] The method for producing a block copolymer of the present invention comprises at least the following step (1), and preferably includes the following step (2) after step (1).

[0159] Step (1): A step of reacting a compound that gives the above-mentioned structural units with a compound that gives the first linker. In this step, at least one of the compounds that gives an ionic segment and a nonionic segment is obtained, in which the structural units are linked by the first linker.

[0160] Step (2): A step in which the product obtained in step (1), i.e., the compound that gives the ionic segment or the compound that gives the nonionic segment, is reacted with the compound that gives the other segment. The compound that gives the other segment means the compound that gives the nonionic segment if the compound obtained in step (1) is the compound that gives the ionic segment, and the compound that gives the ionic segment if the compound obtained in step (1) is the compound that gives the nonionic segment.

[0161] In step (1), either a compound giving an ionic segment or a compound giving a nonionic segment may be obtained, or compounds giving both an ionic segment and a nonionic segment may be obtained. If both compounds are obtained in step (1), in step (2), the compounds obtained in step (1) are reacted with each other to obtain a block copolymer.

[0162] By incorporating these steps (1) and (2), it is possible to obtain a block copolymer with excellent processability and low humidification proton conductivity, in which the phase separation structure and domain size are strictly controlled by the alternating introduction of both segments.

[0163] In step (1), if the desired number-average molecular weight is not reached when reacting the compound that provides the constituent units with the compound that provides the first linker to obtain the segment-forming compound, the compound that provides the first linker may be added to the reaction system. By sequentially adding the compound that provides the first linker to the reaction system, the desired number-average molecular weight of the segment-forming compound can be easily and precisely adjusted.

[0164] The method for producing the block copolymer of the present invention is more preferably to include the following step (1') before step (2).

[0165] Step (1'): A step in which a compound that gives an ionic segment and a compound that gives a nonionic segment are reacted with a compound that gives a second linker to introduce a second linker to both ends of one of the compounds.

[0166] In this step, the segment reacted with the compound that gives the second linker may be the segment in which the first linker was introduced in step (1), or it may be the segment in which the first linker was not introduced. By including step (1'), it is possible to link different segments while suppressing side reactions in the block copolymerization reaction, and a block copolymer with a more precisely controlled structure can be obtained.

[0167] More specific methods for producing block copolymers according to the present invention are illustrated below. However, the present invention is not limited to these.

[0168] Each segment and constituent unit used in the present invention is preferably synthesized by aromatic nucleophilic substitution reaction because it is process-friendly. 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, and any solvent that can be used as a stable solvent in aromatic nucleophilic substitution reaction is acceptable. These organic solvents may be used individually or as a mixture of two or more.

[0169] 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.

[0170] 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.

[0171] The block copolymer in 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.

[0172] The above steps (1) and (2) are specifically illustrated as methods for producing the block copolymer of the present invention. However, the present invention is not limited to these.

[0173] Step (1): A step of reacting a compound that gives a structural unit having -OM groups (where M represents a hydrogen atom, a metal cation, or an ammonium cation) at both ends with a compound that gives a first linker having two or more halide reaction groups to obtain at least one of a compound that gives an ionic segment having -OM groups at both ends and a compound that gives a nonionic segment, with the structural units linked by a linker (L1).

[0174] Step (1'): A step of reacting one of the compounds that gives an ionic segment having -OM groups at both ends and one of the compounds that gives a nonionic segment with a compound that gives a second linker having two or more halide reaction groups to introduce a second linker moiety to both ends of one of the compounds.

[0175] Step (2): A step of reacting the -OM groups at both ends of a compound that gives an ionic segment or a nonionic segment with the second linker moieties at both ends of a compound that gives the other segment.

[0176] Specific examples of compounds that yield a segment represented by general formula (S1) having -OM groups at both ends, and a segment represented by general formula (S3) having -OM groups at both ends, include segments with structures represented by the following general formulas (H3-1) and (H3-2), respectively. Furthermore, when the segments with structures represented by general formulas (H3-1) and (H3-2) are reacted with a halide linker as a second linker, and linkers (L2) are introduced at both ends, examples of structures that can be obtained are those represented by the following general formulas (H3-3) and (H3-4), respectively. However, the present invention is not limited to these.

[0177] [ka]

[0178] In the above general formulas (H3-1) to (H3-4), N1, N2, N3, and N4 each independently represent integers from 1 to 200.

[0179] When the ionic segment has a linker (L1), a specific example of a compound that gives an ionic segment with a linker moiety introduced by step (1) above is the structure represented by the following general formula (H3-1L), and a specific example in which a second linker is introduced at both ends is the structure represented by the following general formula (H3-3L). When the nonionic segment has a linker (L1), a specific example of a compound that gives a nonionic segment with a linker moiety introduced by step (1) above is the structure represented by the following general formula (H3-2L), and a specific example in which a second linker is introduced at both ends is the structure represented by the following general formula (H3-4L). However, the present invention is not limited to these.

[0180] [ka]

[0181] In the above general formulas (H3-1L) to (H3-4L), N5, N6, N7, and N8 each independently represent integers from 1 to 200.

[0182] In the general formulas (H3-1)~(H3-4) and (H3-1L)~(H3-4L), 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 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.

[0183] Furthermore, in the general formulas (H3-1) to (H3-4) and (H3-1L) to (H3-4L), 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.

[0184] The block copolymer of the present invention preferably has a phase separation structure. The phase separation structure can be formed by controlling the molecular chain length, aggregation state, and shape of the ionic and nonionic segments. Examples of phase separation structures include cylinder structures, sea-island structures, lamellar structures, and co-continuous structures. Among these, the co-continuous structure is preferred. When the block copolymer has a co-continuous phase separation structure, three-dimensionally continuous proton conduction channels are formed, thus achieving excellent proton conductivity. Similarly, the nonionic hydrophobic segments also form three-dimensionally continuous domains, resulting in excellent fuel barrier properties, solvent resistance, dimensional stability, mechanical strength, and physical durability.

[0185] The existence of a phase-separated structure in a block copolymer can be confirmed by analyzing a "film" obtained by coating a solution of the block copolymer dissolved or dispersed in a suitable solvent onto a support substrate and drying it, using a transmission electron microscope (TEM), small-angle X-ray scattering (SAXS), atomic force microscope (AFM), etc.

[0186] Furthermore, the polymer electrolyte material, polymer electrolyte molded body, and polymer electrolyte membrane containing the block copolymer of the present invention preferably have a phase separation structure, and are particularly preferably co-continuous phase separation structure. Details will be described later.

[0187] (polymer electrolyte molded body) The block copolymer of the present invention is suitable as a polymer electrolyte material and can be processed into a polymer electrolyte molded body. The form of the molded body is not particularly limited, but examples include binders for electrode catalyst layers, fibers, membranes, rods, etc. Among these, membranes and binders are preferred, and membranes are particularly preferred. The molded body preferably has a phase separation structure, and is particularly preferred to have a co-continuous phase separation structure.

[0188] (polymer electrolyte membrane) A polymer electrolyte membrane using the block copolymer of the present invention as the electrolyte material preferably has a phase separation structure, and is particularly preferably a co-continuous phase separation structure. The phase separation structure can be analyzed by transmission electron microscopy (TEM), small-angle X-ray scattering (SAXS), atomic force microscopy (AFM), etc., as described above.

[0189] The polymer electrolyte molded articles and polymer electrolyte membranes using the block copolymer of the present invention are preferably those in which a phase separation structure is observed when observed by TEM at 50,000x magnification, and the average period size measured by image processing is 8 nm or more and 300 nm or less. In particular, an average period size of 10 nm or more and 200 nm or less is more preferable, and most preferably 15 nm or more and 150 nm or less. The period size refers to the period length of the domains formed by the aggregation of ionic segments and the domains formed by the aggregation of nonionic segments.

[0190] When forming the block copolymer of the present invention into a film, methods such as forming the film from a solution state or from a molten state are possible at the stage where a protecting group such as a ketal is present. In the former method, for example, one example is to dissolve the polymer electrolyte material in a solvent such as N-methyl-2-pyrrolidone, cast the solution onto a glass plate or the like, and then remove the solvent to form a film.

[0191] The solvent used for film formation can be any solvent that dissolves the block copolymer 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 preferred; ester solvents such as γ-butyrolactone and butyl acetate are preferred; carbonate solvents such as ethylene carbonate and propylene carbonate are preferred; alkylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, and propylene glycol monoethyl ether are preferred; or alcohol solvents such as isopropanol, water, and mixtures thereof are preferred. However, aprotic polar solvents have the highest solubility and are therefore preferred. In addition, it is preferable to add crown ethers such as 18-crown-6 to increase the solubility of the ionic segment.

[0192] Furthermore, in the present invention, when forming a solution film using a block copolymer, the choice of solvent is important for the phase separation structure, and a mixture of an aprotic polar solvent and a less polar solvent is also a suitable method.

[0193] A preferred method for obtaining a tough film is to remove foreign matter present in the polymer electrolyte solution by subjecting the polymer solution, which has been prepared to the required solid content concentration, to atmospheric pressure filtration or pressurized filtration. The filter material used here is not particularly limited, but glass filters or metallic filters are also preferred. A filter is preferred. In this filtration, the minimum pore size of the filter through which the polymer solution passes is preferably 1 μm or less.

[0194] One method for converting the block copolymer of the present invention into a polymer electrolyte membrane is to fabricate a membrane composed of the block copolymer using the above method, and then deprotect 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 fabricate a solution membrane of a block copolymer with poor solubility, and to achieve both proton conductivity, mechanical strength, and physical durability.

[0195] Alternatively, after forming the electrolyte membrane with the ionic groups forming 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 formed membrane with an acidic aqueous solution, and more preferably a step of immersing the formed membrane in an acidic aqueous solution. In this step, protons in the acidic aqueous solution are replaced by cations ionically bonded to the ionic groups, and residual water-soluble impurities, residual monomers, solvents, and residual salts are simultaneously removed.

[0196] 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.

[0197] In the present invention, the film thickness of the polymer electrolyte membrane is preferably 1 μm or more to obtain mechanical strength and physical durability of a membrane that can withstand practical use, and preferably 2,000 μm or less to reduce membrane resistance, i.e., to improve power generation performance. A more preferable range for film thickness is 3 μm to 200 μm. The film thickness can be controlled by the solution concentration or the coating thickness on the substrate.

[0198] Furthermore, the polymer electrolyte membrane in the present invention 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.

[0199] Furthermore, the polymer electrolyte membrane made of the block copolymer obtained by the present invention may contain various polymers, elastomers, fillers, fine particles, various additives, etc., to improve mechanical strength, thermal stability, processability, etc., within a range that does not adversely affect the aforementioned properties. The polymer electrolyte membrane may also be reinforced with a microporous membrane, nonwoven fabric, mesh, etc.

[0200] The block copolymer of the present invention can be applied to various uses as a polymer electrolyte material, such as polymer electrolyte molded bodies and polymer electrolyte membranes. For example, it can be applied to 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. Among these, it is most preferably used in 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.

[0201] In polymer electrolyte fuel cells, electrochemical hydrogen pumps, and water electrolysis hydrogen generators, polymer electrolyte membranes are used in structures in which a catalyst layer, an electrode substrate, and a separator are sequentially laminated on both sides. Of these, those in which catalyst layers are laminated on both sides of the electrolyte membrane (i.e., a layer configuration of catalyst layer / electrolyte membrane / catalyst layer) are called catalyst-coated electrolyte membranes (CCMs), and those in which a catalyst layer and a gas diffusion substrate are sequentially laminated on both sides of the electrolyte membrane (i.e., a layer configuration of gas diffusion substrate / catalyst layer / electrolyte membrane / catalyst layer / gas diffusion substrate) are called membrane electrode composites (MEAs). The block copolymer of the present invention is particularly suitable for use as a polymer electrolyte membrane constituting such CCMs and MEAs. [Examples]

[0202] (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.

[0203] (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 defined as the point at which 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).

[0204] (3) Change rate of dimensions when 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 (%).

[0205] (4) Observation of phase separation structure using a transmission electron microscope (TEM) The sample pieces were immersed in a 2 wt% lead acetate aqueous solution as a staining agent and left at 25°C for 72 hours. The stained samples were removed and embedded in epoxy resin. Using an ultramicrotome, 80 nm thin sections were cut at room temperature, and the obtained thin sections were collected on a Cu grid and subjected to TEM observation. Observation was performed at an accelerating voltage of 100 kV, and images were taken at magnifications of ×20,000 and ×40,000. The instrument used was an HT7700 (manufactured by Hitachi High-Tech Corporation).

[0206] (5) Observation of phase separation structure by transmission electron microscopy (TEM) tomography The thin section samples prepared by the method described in (4) 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.

[0207] 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.

[0208] (6) 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. An electrolyte membrane 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 film 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.

[0209] 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).

[0210] 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%.

[0211] [Chemical formula]

[0212] 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 reagent) at 100 °C for 10 hours. Then, it was gradually added to a large amount of water, neutralized with NaOH, and 200 g of sodium chloride (NaCl) was added to precipitate the synthesized product. The obtained precipitate was filtered off and recrystallized with an aqueous ethanol solution to obtain disodium-3,3'-disulfonate-4,4'-difluorobenzophenone. The purity was 99.3%.

[0213] [Chemical formula]

[0214] Synthesis Example 3 (Synthesis of sodium 3,3'-disulfonate-4,4'-difluorodiphenyl sulfone represented by the following formula (G3)) 109.1 g of 4,4-difluorodiphenyl sulfone (Aldrich reagent) was reacted in 150 mL of fuming sulfuric acid (50% SO3) (Wako Pure Chemical reagent) at 100 °C for 10 hours. Then, it was gradually added to a large amount of water, neutralized with NaOH, and 200 g of sodium chloride was added to precipitate the synthesized product. The obtained precipitate was filtered off and recrystallized with an aqueous ethanol solution to obtain sodium 3,3'-disulfonate-4,4'-difluorodiphenyl sulfone. The purity was 99.3%.

[0215] [Chemical formula]

[0216] Example 1 (Synthesis of non-ionic 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 carried out at 150°C, followed by heating to remove the toluene, and polymerization was carried out at 170°C for 3 hours. Reprecipitation and purification in a large amount of methanol were performed to obtain the terminal hydroxyl form of nonionic oligomer a1. The number-average molecular weight of the terminal hydroxyl form of this nonionic oligomer a1 was 20,000.

[0217] 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.

[0218] [ka]

[0219] (Synthesis of ionic oligomer a2 represented by the general formula (G5) below) 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 was purified by reprecipitation with a large amount of isopropyl alcohol to obtain the ionic oligomer a2 (terminal: hydroxyl group) represented by the following general formula (G5). 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.

[0220] [ka]

[0221] (Synthesis of the ionic oligomer a2' represented by the general formula (G6) below) 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) 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.

[0222] [ka]

[0223] (Synthesis of block copolymer b1 containing oligomer a2' as the ionic segment and oligomer a1 as the nonionic segment) 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.

[0224] The obtained block copolymer b1 was dissolved in a 20 wt% NMP solution, which was pressure filtered through a glass fiber filter. The solution was then cast onto a glass substrate and dried at 100°C for 4 hours to obtain a film-like molded body. This molded body was immersed in a 10 wt% sulfuric acid aqueous solution at 80°C for 24 hours to undergo proton substitution and deprotection reactions. After that, it was thoroughly washed by immersion in a large excess of pure water for 24 hours to obtain a polymer electrolyte membrane A (film thickness 10 μm). TEM and TEM tomography observations confirmed a co-continuous-like phase separation structure, with both hydrophilic domains containing ionic groups and hydrophobic domains not containing ionic groups forming a continuous phase.

[0225] Example 2 (Synthesis of nonionic oligomer a3 represented by general formula (G4)) The terminal hydroxy compound of oligomer a3 was obtained in the same manner as the synthesis of the terminal hydroxy compound of oligomer a1, except that 21.45 g of 4,4'-difluorobenzophenone was used. The number-average molecular weight of this terminal hydroxy compound of oligomer a3 was 25,000.

[0226] 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.

[0227] (Synthesis of block copolymer b2 containing oligomer a2’ as the ionic segment and oligomer a3 as the nonionic segment) A block copolymer b2 was obtained in the same manner as the synthesis of block copolymer b1, except that nonionic oligomer a3 (12.3 g) was used instead of nonionic oligomer a1 (7.65 g). The number average molecular weight of this block copolymer b3 was 160,000, and the weight average molecular weight was 390,000.

[0228] A polymer electrolyte membrane B (membrane thickness: 10 μm) was obtained in the same manner as in Example 1, except that block copolymer b2 was used instead of block copolymer b1. By TEM and TEM tomography observations, a co-continuous-like phase separation structure was confirmed, and both the hydrophilic domain containing ionic groups and the hydrophobic domain containing no ionic groups formed continuous phases.

[0229] Example 3 (Synthesis of nonionic oligomer a1’ represented by the following general formula (G7)) 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 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 a1' (terminal: fluoro group) represented by the following general formula (G7). The number-average molecular weight of this nonionic oligomer a1' was 21,000. In general formula (G7), m represents an integer of 1 or greater.

[0230] [ka]

[0231] (Synthesis of ionic oligomer a4 represented by 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.

[0232] (Synthesis of ionic oligomer a4' represented by the general formula (G8) below) In a 2,000 mL SUS 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 oligomer a4 containing ionic groups 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 a4' (terminus: OM) represented by general formula (G8). The number-average molecular weight of this ionic oligomer a4' was 70,000. In general formula (G8), M represents a hydrogen atom, Na, or K, and n represents an integer of 1 or more.

[0233] [ka]

[0234] (Synthesis of block copolymer b3 containing oligomer a4' as an ionic segment and oligomer a1' as a nonionic segment) Block copolymer b3 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 the amount of nonionic oligomer a1' used was 5.80 g. The number-average molecular weight of this block copolymer b3 was 100,000, and the weight-average molecular weight was 260,000.

[0235] A polymer electrolyte membrane C (thickness 10 μm) was obtained in the same manner as in Example 1, except that block copolymer b3 was used instead of block copolymer b1. TEM and TEM tomography observations confirmed a co-continuous phase separation structure, with both hydrophilic domains containing ionic groups and hydrophobic domains not containing ionic groups forming a continuous phase.

[0236] Example 4 (Synthesis of nonionic oligomer a5 represented by the general formula (G9) below) The terminal hydroxyl derivative of oligomer a5 was obtained in the same manner as the synthesis of the terminal hydroxyl derivative of oligomer a1, except that 4,4'-difluorodiphenylsulfone (24.92 g) was used instead of 4,4'-difluorobenzophenone. The number-average molecular weight of this terminal hydroxyl derivative of oligomer a5 was 20,000.

[0237] Nonionic oligomer a5 (terminal fluoro group) represented by general formula (G9) was obtained in the same manner as the synthesis of oligomer a1, except that 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 21,000. In general formula (G9), m represents an integer of 1 or more.

[0238] [ka]

[0239] (Synthesis of ionic oligomer a6 represented by the general formula (G10) below) Ionic oligomer a6 (terminal hydroxyl group) represented by general formula (G10) 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 a6 was 41,000. In general formula (G10), M represents a hydrogen atom, Na, or K, and n represents an integer of 1 or more.

[0240] [ka]

[0241] (Synthesis of ionic oligomer a6' represented by the general formula (G11) below) An NMP solution containing the ionic oligomer a6' (terminus: OM) represented by general formula (G11) was obtained in the same manner as the synthesis of ionic oligomer a2', except that ionic oligomer a6 (45.76 g) was used instead of ionic oligomer a2 (49.0 g), and 16.35 g of 2,6-difluorobenzonitrile / NMP solution (1 wt%) was used instead of 19.8 g of hexafluorobenzene / NMP solution (1 wt%). The number-average molecular weight of this ionic oligomer a6' was 82,000. In general formula (G11), M represents a hydrogen atom, Na, or K, and n represents an integer of 1 or more.

[0242] [ka]

[0243] (Synthesis of block copolymer b4 containing oligomer a6' as the ionic segment and oligomer a5 as the nonionic segment) Block copolymer b4 was obtained in the same manner as the synthesis of block copolymer b1, except that ionic oligomer a6' (45.76 g) was used instead of ionic oligomer a2' (49.0 g), and nonionic oligomer a5 (13.12 g) was used instead of nonionic oligomer a1 (7.65 g). The number-average molecular weight of this block copolymer b4 was 160,000, and the weight-average molecular weight was 380,000.

[0244] A polymer electrolyte membrane D (thickness 12 μm) was obtained in the same manner as in Example 1, except that block copolymer b4 was used instead of block copolymer b1. TEM and TEM tomography observations confirmed a co-continuous phase separation structure, with both hydrophilic domains containing ionic groups and hydrophobic domains not containing ionic groups forming a continuous phase.

[0245] Example 5 (Synthesis of ionic oligomer precursor a7 represented by the general formula (G12) below) In a 2,000 mL SUS polymerization apparatus equipped with a stirrer, nitrogen inlet tube, and Dean-Stark trap, 200 mL of dry N,N-dimethylacetamide (DMAc), 16.9 g (42 mmol) of neopentyl 3-(2,5-dichlorobenzoyl)benzenesulfonic acid, and 0.09 g (0.7 mmol) of 4-chlorophenol were added and stirred at 80°C for 2 hours under a nitrogen atmosphere. Then, 30 g (109 mmol) of bis(1,5-cyclooctadiene)nickel was added and stirred for 4 hours. Dilution with 300 mL of dry DMAc, 1 L of acetone was added, and after coagulation, the mixture was vacuum-dried at 80°C to obtain ionic oligomer precursor a7 (terminus: hydroxyl group) represented by the following general formula (G12). The number-average molecular weight was 22,000. In general formula (G12), n represents an integer of 1 or more.

[0246] [ka]

[0247] (Synthesis of the ionic oligomer precursor a7' represented by the general formula (G13) below) In a 2,000 mL SUS polymerization apparatus equipped with a stirrer, nitrogen inlet tube, and Dean-Stark trap, 0.56 g of potassium carbonate (Aldrich reagent, 400 mmol) and 11.1 g of ionic oligomer a12 were added. After purging the apparatus with nitrogen, 200 mL of dry DMAc was added, and the contents were dissolved at 60°C. Then, 30.6 g of hexafluorobenzene / DMAc solution (1 wt%) was added. The reaction was carried out at 80°C for 24 hours to obtain a DMAc solution containing the ionic oligomer precursor a7' (terminus: OM) represented by the following formula (G13). The number-average molecular weight of the ionic oligomer precursor a7' was 67,000. In the general formula (G13), M represents a hydrogen atom, Na, or K, and n represents an integer of 1 or more.

[0248] [ka]

[0249] (Synthesis of nonionic oligomer a8 represented by the general formula (G14) below) In a 2,000 mL SUS polymerization apparatus equipped with a stirrer, nitrogen inlet tube, and Dean-Stark trap, 200 mL of dry NMP, 10.08 g (40 mmol) of 2,5-dichlorobenzophenone, and 0.12 g (0.9 mmol) of 4-chlorophenol were added and stirred at 80°C for 2 hours under a nitrogen atmosphere. Then, 30 g (109 mmol) of bis(1,5-cyclooctadiene)nickel was added and the mixture was stirred for 4 hours. The mixture was diluted with 300 mL of dry NMP, precipitated in 1 L of 10 wt% hydrochloric acid aqueous solution, and then vacuum-dried at 80°C to obtain the terminal hydroxyl derivative of the nonionic oligomer a8 represented by the following general formula (G14). The number-average molecular weight was 9,000.

[0250] Nonionic oligomer a8 (terminal fluoro group), represented by the following general formula (G14), was obtained in the same manner as the synthesis of nonionic oligomer a1, except that 9.0 g (1 mmol) of the terminal hydroxyl form of nonionic oligomer a8 was used instead of 20.0 g of the terminal hydroxyl form of nonionic oligomer a1. The number-average molecular weight of this nonionic oligomer a8 was 10,000. In general formula (G14), m represents an integer of 1 or more.

[0251] [ka]

[0252] (Synthesis of block copolymer b5, represented by the general formula (G15) below, containing ionic oligomer a7'' as an ionic segment and oligomer a8 as a nonionic segment) In a 2,000 mL stainless steel polymerization apparatus equipped with a stirrer, nitrogen inlet tube, and Dean-Stark trap, 11.1 g of ionic oligomer precursor a7' and 5.71 g of nonionic oligomer a8 were added. DMAc was added to bring the total amount of oligomers to 7 wt%, and the reaction was carried out at 105°C for 24 hours. The polymerization reaction solution was diluted with 500 mL of DMAc, stirred for 30 minutes, and filtered using Celite as a filter aid.

[0253] The filtrate was concentrated using an evaporator, and 21.9 g (0.253 mol) of lithium bromide was added to the residue. The mixture was reacted at an internal temperature of 110°C for 7 hours under a nitrogen atmosphere. After the reaction, it was cooled to room temperature, poured into 3 L of acetone, and allowed to solidify. The solidified material was filtered, air-dried, pulverized in a mixer, and washed with 1500 mL of 1N hydrochloric acid while stirring. After filtration, the product was washed with deionized water until the pH of the washing solution was 5 or higher. The mixture was then dried overnight at 80°C to obtain block copolymer b5 having the ionic oligomer a7'' represented by the following general formula (G15). From the structural formula and number-average molecular weight of the ionic oligomer precursor a7' represented by general formula (G13), the number-average molecular weight of the ionic oligomer a7'' is calculated to be 53,000. The number-average molecular weight of block copolymer b5 was 90,000, and the weight-average molecular weight was 210,000. In general formula (G15), * represents a bond with a nonionic segment, and n represents an integer greater than or equal to 1.

[0254] [ka]

[0255] Block copolymer b5 was dissolved in a solvent consisting of NMP / methanol = 30 / 70 (mass%) at a concentration of 0.1 g / g. After pressure filtration through a glass fiber filter, the solution was cast onto a glass substrate and dried at 100°C for 4 hours to obtain a film-like molded body. This molded body was immersed in a 10 mass% sulfuric acid aqueous solution at 80°C for 24 hours, and then thoroughly washed by immersion in a large excess of pure water for 24 hours to obtain a polymer electrolyte membrane E (film thickness 10 μm). TEM and TEM tomography observations confirmed a co-continuous-like phase separation structure, with both hydrophilic domains containing ionic groups and hydrophobic domains not containing ionic groups forming a continuous phase.

[0256] Comparative Example 1 (Synthesis of nonionic oligomer a9 represented by 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 20.84 g of 4,4'-difluorobenzophenone was used. The number-average molecular weight of this terminal hydroxyl derivative of nonionic oligomer a9 was 9,000.

[0257] 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 9.0 g (1 mmol) of the terminal hydroxyl group of nonionic oligomer a9 was used instead of 20.0 g of the terminal hydroxyl group of nonionic oligomer a1. The number-average molecular weight of this nonionic oligomer a9 was 10,000.

[0258] (Synthesis of ionic oligomer a10 represented by 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- 26.40 g of Crown-6 (100 mmol from Wako Pure Chemical Industries) 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 the ionic oligomer a10 (terminus: hydroxyl group) represented by general formula (G5). The number-average molecular weight of this ionic oligomer a10 was 42,000.

[0259] (Synthesis of block copolymer b6 containing oligomer a10 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 a10 (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.

[0260] A polymer electrolyte membrane F (thickness 10 μm) was obtained in the same manner as in Example 1, except that block copolymer b6 was used instead of block copolymer b1. TEM and TEM tomography observations confirmed a co-continuous-like phase separation structure, with both hydrophilic domains containing ionic groups and hydrophobic domains not containing ionic groups forming a continuous phase.

[0261] Comparative Example 2 (Synthesis of nonionic oligomer a11 represented by 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.

[0262] 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 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. 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.

[0263] (Synthesis of block copolymer b7 containing oligomer a10 as an ionic segment and oligomer a11 as a nonionic segment) 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.

[0264] A polymer electrolyte membrane G (thickness 10 μm) was obtained in the same manner as in Example 1, except that block copolymer b7 was used instead of block copolymer b1. TEM and TEM tomography observations confirmed a co-continuous-like phase separation structure, with both hydrophilic domains containing ionic groups and hydrophobic domains not containing ionic groups forming a continuous phase, although some discontinuous structures were observed.

[0265] Comparative Example 3 (Synthesis of nonionic oligomer a12 represented by general formula (G9)) The terminal hydroxyl derivative of nonionic oligomer a12 was obtained in the same manner as the synthesis of the terminal hydroxyl derivative 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 derivative of nonionic oligomer a12 was 10,000.

[0266] Nonionic oligomer a12 (terminal fluoro group) represented by general formula (G9) 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 a12 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 a12 was 11,000.

[0267] (Synthesis of block copolymer b8 containing oligomer a6 as an ionic segment and oligomer a12 as a nonionic segment) In a 2,000 mL stainless steel polymerization apparatus equipped with a stirrer, nitrogen inlet tube, and Dean-Stark trap, 45.76 g of ionic oligomer a6 and 8.93 g of nonionic oligomer a12 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 b8. The number-average molecular weight of this block copolymer b8 was 120,000, and the weight-average molecular weight was 290,000.

[0268] A polymer electrolyte membrane H (thickness 10 μm) was obtained in the same manner as in Example 1, except that block copolymer b8 was used instead of block copolymer b1. TEM and TEM tomography observations confirmed a co-continuous-like phase separation structure, with both hydrophilic domains containing ionic groups and hydrophobic domains not containing ionic groups forming a continuous phase.

[0269] Example 6 (Synthesis of nonionic oligomer a13 (terminal: hydroxyl group) represented by the general formula (G16) below) In a 2,000 mL SUS 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 20.79 g of 4,4'-difluorobenzophenone (Aldrich reagent, 95.2 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, then the temperature was increased 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 nonionic oligomer a13 (terminated: hydroxyl group). The number-average molecular weight of this nonionic oligomer a13 (terminated: hydroxyl group) was 8,000. In general formula (G16), M represents a hydrogen atom, Na, or K, and m represents an integer of 1 or more.

[0270] [ka]

[0271] (Synthesis of nonionic oligomer a14 (terminal: hydroxyl group) represented by the general formula (G17) below) 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 50.0 g of nonionic oligomer a14 were added. After purging the apparatus with nitrogen, 500 mL of NMP was added, and the contents were dissolved at 60°C. Then, 58.1 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 nonionic oligomer a14 (terminus: hydroxyl group) represented by general formula (G17). The number-average molecular weight of this ionic oligomer a2' was 16,000. In general formula (G17), M represents a hydrogen atom, Na, or K, and m represents an integer of 1 or more.

[0272] [ka]

[0273] (Synthesis of nonionic oligomer a15 (terminal: fluoro group) represented by the general formula (G18) below) 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 16.0 g (1 mmol) of the above nonionic oligomer a14 (terminus: hydroxyl group) 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, then heated 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 a15 (terminus: fluoro group) represented by the following general formula (G18). The number-average molecular weight of this nonionic oligomer a15 was 17,000. In general formula (G18), m represents an integer of 1 or more.

[0274] [ka]

[0275] (Synthesis of ionic oligomer a16 represented by 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 (50 mmol) of 4,4'-biphenol (Aldrich reagent, 50 mmol), 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 apparatus with nitrogen, 300 mL of dimethyl sulfoxide (DMSO) and 100 mL of toluene were added. Dehydration was carried out at 133°C, followed by heating to remove toluene, polymerization was carried out at 150°C for 2 hours, and then the temperature was raised to 155°C for a further 1 hour. Purification was performed by reprecipitation with a large amount of isopropyl alcohol to obtain the ionic oligomer a16 (terminus: hydroxyl group) represented by general formula (G5). The number-average molecular weight of this ionic oligomer a16 was 56,000.

[0276] (Synthesis of block copolymer b9 containing oligomer a16 as an ionic segment and oligomer a15 as a nonionic segment) Block copolymer b9 was obtained in the same manner as the synthesis of block copolymer b1, except that ionic oligomer a16 (49.0 g) was used instead of ionic oligomer a2' (49.0 g), and nonionic oligomer a15 (12.3 g) was used instead of nonionic oligomer a1 (7.65 g). The number-average molecular weight of this block copolymer b9 was 170,000, and the weight-average molecular weight was 390,000.

[0277] A polymer electrolyte membrane I (thickness 10 μm) was obtained in the same manner as in Example 1, except that block copolymer b9 was used instead of block copolymer b1. Co-continuous phase separation structure was confirmed by TEM and TEM tomography observation, and both the hydrophilic domain containing ionic groups and the hydrophobic domain not containing ionic groups formed a continuous phase.

[0278] Example 7 (Synthesis of nonionic oligomer a17 (terminal: hydroxyl group) represented by general formula (G16)) Nonionic oligomer a17 (terminal: hydroxyl group) was obtained in the same manner as the synthesis of nonionic oligomer a13 (terminal: hydroxyl group), except that the amount of 4,4'-difluorobenzophenone used was 20.88 g. The number-average molecular weight of this nonionic oligomer a17 (terminal: hydroxyl group) was 10,000.

[0279] (Synthesis of nonionic oligomer a18 (terminal: hydroxyl group) represented by general formula (G17)) Nonionic oligomer a18 (terminal: hydroxyl group) was obtained in the same manner as the synthesis of nonionic oligomer a14 (terminal: hydroxyl group), except that 46.5 g of hexafluorobenzene / NMP solution (1 wt%) was used. The number-average molecular weight of this nonionic oligomer a18 (terminal: hydroxyl group) was 20,000.

[0280] (Synthesis of nonionic oligomer a19 (terminal: fluoro group) represented by general formula (G18)) Nonionic oligomer a19 (terminal: fluoro group), represented by general formula (G18), was obtained in the same manner as the synthesis of nonionic oligomer a15 (terminal: fluoro group), except that 20.0 g (1 mmol) of nonionic oligomer a18 (terminal: hydroxyl group) was used instead of 16.0 g of nonionic oligomer a14 (terminal: hydroxyl group). The number-average molecular weight of this nonionic oligomer a19 was 21,000.

[0281] (Synthesis of block copolymer b10 containing oligomer a16 as an ionic segment and oligomer a19 as a nonionic segment) Block copolymer b10 was obtained in the same manner as the synthesis of block copolymer b1, except that ionic oligomer a16 (49.0 g) was used instead of ionic oligomer a2' (49.0 g), and nonionic oligomer a19 (17.3 g) was used instead of nonionic oligomer a1 (7.65 g). The number-average molecular weight of block copolymer b10 was 170,000, and the weight-average molecular weight was 380,000.

[0282] A polymer electrolyte membrane J (thickness 10 μm) was obtained in the same manner as in Example 1, except that block copolymer b10 was used instead of block copolymer b1. TEM and TEM tomography observations confirmed a co-continuous-like phase separation structure, with both hydrophilic domains containing ionic groups and hydrophobic domains not containing ionic groups forming a continuous phase.

[0283] Example 8 (Synthesis of nonionic oligomer a20 (terminal: hydroxyl group) represented by general formula (G16)) Nonionic oligomer a20 (terminal: hydroxyl group) was obtained in the same manner as the synthesis of nonionic oligomer a13 (terminal: hydroxyl group), except that the amount of 4,4'-difluorobenzophenone used was 21.18 g. The number-average molecular weight of this nonionic oligomer a20 (terminal: hydroxyl group) was 15,000.

[0284] (Synthesis of nonionic oligomer a21 (terminal: hydroxyl group) represented by general formula (G17)) Nonionic oligomer a21 (terminal: hydroxyl group) was obtained in the same manner as the synthesis of nonionic oligomer a14 (terminal: hydroxyl group), except that 31.0 g of hexafluorobenzene / NMP solution (1 wt%) was used. The number-average molecular weight of this nonionic oligomer a21 (terminal: hydroxyl group) was 30,000.

[0285] (Synthesis of nonionic oligomer a22 (terminal: fluoro group) represented by general formula (G18)) Nonionic oligomer a22 (terminal: fluoro group), represented by general formula (G18), was obtained in the same manner as the synthesis of nonionic oligomer a15 (terminal: fluoro group), except that 30.0 g (1 mmol) of nonionic oligomer a21 (terminal: hydroxyl group) was used instead of 16.0 g of nonionic oligomer a14 (terminal: hydroxyl group). The number-average molecular weight of this nonionic oligomer a22 was 31,000.

[0286] (Synthesis of block copolymer b11 containing oligomer a2' as an ionic segment and oligomer a22 as a nonionic segment) Block copolymer b11 was obtained in the same manner as the synthesis of block copolymer b1, except that nonionic oligomer a22 (15.0 g) was used instead of nonionic oligomer a1 (7.65 g). The number-average molecular weight of block copolymer b11 was 180,000, and the weight-average molecular weight was 390,000.

[0287] A polymer electrolyte membrane K (thickness 10 μm) was obtained in the same manner as in Example 1, except that block copolymer b11 was used instead of block copolymer b1. TEM and TEM tomography observations confirmed a co-continuous phase separation structure, with both hydrophilic domains containing ionic groups and hydrophobic domains not containing ionic groups forming a continuous phase. [Measurement results] Table 1 shows the measurement results of the block copolymers obtained in the examples and comparative examples, and the polymer electrolyte membranes using the block copolymers.

[0288] [Table 1]

[0289] Reference example 1 Six batches of ionic segments (oligomers) with a target number-average molecular weight of 40,000 were synthesized under identical conditions according to the synthesis method described below.

[0290] (Synthesis of oligomers a101-a106 of the constituent units represented by 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 (50 mmol) of 4,4'-biphenol (Aldrich reagent, 50 mmol), 40.11 g (95.0 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 oligomers were purified by reprecipitation with a large amount of isopropyl alcohol to obtain ionic oligomers a101-a106 (terminus: hydroxyl group) represented by general formula (G5). The number-average molecular weights of these oligomers a101-a106 are shown in Table 2.

[0291] (Synthesis of ionic oligomers a101'~a106' represented by general formula (G8)) In a 2,000 mL SUS polymerization apparatus equipped with a stirrer, nitrogen inlet tube, and Dean-Stark trap, 0.56 g of potassium carbonate (Aldrich reagent, 400 mmol) and 45.00 g of an oligomer of the above constituent unit (one of a101 to a106) were added. After purging the apparatus with nitrogen, 400 mL of NMP was added, and the contents were dissolved at 60°C. Then, 22.0 g of 2,6-difluorobenzonitrile / NMP solution (1 wt%) was added. The reaction was carried out at 80°C for 10 hours, and the number-average molecular weight of 40,000 was confirmed by GPC measurement. If the number-average molecular weight of 40,000 was not reached, 2.0 g of 2,6-difluorobenzonitrile / NMP solution (1 wt%) was added, and the reaction was carried out at 80°C for 2 hours. The process of confirming the number-average molecular weight by GPC measurement was repeated until the number-average molecular weight of 40,000 was reached. Using this synthesis method, six batches were synthesized, yielding an NMP solution containing ionic oligomers a101'~a106' (terminus: hydroxyl group) represented by general formula (G8).

[0292] Table 2 shows the number-average molecular weight of the oligomers obtained in each batch and the amount of linker L1 (2,6-difluorobenzonitrile / NMP solution (1 wt%)) added. The number-average molecular weight of the ionic oligomers a101' to a106' was all 40,000, which was the same as the target number-average molecular weight (40,000).

[0293] Reference example 2 Six batches of ionic segments (oligomers) with a target number-average molecular weight of 40,000 were synthesized under identical conditions according to the synthesis method described below. No linker compounds were used in this synthesis.

[0294] (Synthesis of ionic oligomers a201-a206 represented by 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), 41.43 g (98.1 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 oligomers were purified by reprecipitation with a large amount of isopropyl alcohol to obtain ionic oligomers a201-a206 (terminus: hydroxyl group) represented by general formula (G5). Their number-average molecular weights are shown in Table 2.

[0295] The number-average molecular weights of the ionic oligomers a201-a206 obtained from the synthesis of 6 batches showed considerable variation compared to the target number-average molecular weight.

[0296] [Table 2]

[0297] Reference example 3 An ionic segment (oligomer) with a target number-average molecular weight of 90,000 was synthesized according to the following synthesis method.

[0298] (Synthesis of ionic oligomer a301 represented by general formula (G8)) 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 45.0 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, 15.0 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 a301 (terminus: hydroxyl group) represented by general formula (G8). The number-average molecular weight of this ionic oligomer a301 was 90,000, which was the same as the target number-average molecular weight.

[0299] Reference example 4 An ionic segment (oligomer) with a target number-average molecular weight of 90,000 was synthesized according to the following synthetic method. No linker compound was used in this synthesis.

[0300] (Synthesis of ionic oligomer a401 represented by 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), 41.93 g (99.3 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 DMSO and 100 mL of toluene were added. Dehydration was carried out at 130°C, then the temperature was raised to remove the toluene, polymerization was carried out at 150°C for 2 hours, and then the temperature was raised to 155°C for a further 3 hours of polymerization. The oligomer a401 (terminus: hydroxyl group), represented by general formula (G5), was purified by reprecipitation with a large amount of isopropyl alcohol. The number-average molecular weight of the ionic oligomer a401 obtained by this synthesis was 56,000, and the target number-average molecular weight of 90,000 could not be achieved.

[0301] Reference example 5 The target nonionic segment (oligomer) with a number-average molecular weight of 30,000 was synthesized in six batches under identical conditions according to the synthesis method described below.

[0302] (Synthesis of oligomers a501-a506 of the constituent units represented by general formula (G16)) 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 21.19 g of 4,4'-difluorobenzophenone (Aldrich reagent, 97.1 mmol) were added. After purging the apparatus with nitrogen, 300 mL of N-methylpyrrolidone (NMP) and 100 mL of toluene were added. Dehydration was carried out at 150°C, followed by heating to remove the toluene, and polymerization was carried out at 170°C for 3 hours. Reprecipitation and purification in a large amount of methanol were performed to obtain nonionic oligomers a501 to a506 (terminus: hydroxyl group) represented by general formula (G16). The number-average molecular weights of these oligomers a501 to a506 are shown in Table 3.

[0303] (Synthesis of nonionic oligomers a501'~a506' represented by the general formula (G19) below) In a 2,000 mL SUS polymerization apparatus equipped with a stirrer, nitrogen inlet tube, and Dean-Stark trap, 0.56 g of potassium carbonate (Aldrich reagent, 400 mmol) and 50.00 g of an oligomer of the above constituent unit (one of a501 to a506) were added. After purging the apparatus with nitrogen, 400 mL of NMP was added, and the contents were dissolved at 60°C. Then, 18.0 g of 2,6-difluorobenzonitrile / NMP solution (1 wt%) was added. The reaction was carried out at 80°C for 8 hours, and the number average molecular weight was confirmed by GPC measurement to determine if it reached 30,000. If the number average molecular weight was not reached, 2.0 g of 2,6-difluorobenzonitrile / NMP solution (1 wt%) was added, and the reaction was carried out at 80°C for 2 hours. The process of confirming the number average molecular weight by GPC measurement was repeated until the number average molecular weight reached 30,000. Using this synthesis method, six batches were synthesized, yielding an NMP solution containing the nonionic oligomers a501'~a506' (terminus: hydroxyl group) represented by general formula (G19).

[0304] Table 3 shows the number-average molecular weight of the oligomers obtained in each batch and the amount of linker L1 (2,6-difluorobenzonitrile / NMP solution (1 wt%)) added. The number-average molecular weight of the ionic oligomers a501' to a506' was all 30,000, which was the same as the target number-average molecular weight (30,000). In general formula (G19), M represents a hydrogen atom, Na, or K, and m represents an integer of 1 or more.

[0305] [ka]

[0306] Reference example 6 Six batches of nonionic segments (oligomers) with a target number-average molecular weight of 30,000 were synthesized under identical conditions according to the synthetic method described below. No linker compounds were used in this synthesis.

[0307] (Synthesis of ionic oligomers a601-a606 represented by general formula (G16)) 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 21.52 g of 4,4'-difluorobenzophenone (Aldrich reagent, 98.1 mmol) were added. After purging the apparatus with nitrogen, 300 mL of N-methylpyrrolidone (NMP) and 100 mL of toluene were added. Dehydration was carried out at 150°C, followed by heating to remove the toluene, and polymerization was carried out at 170°C for 3 hours. Reprecipitation and purification in a large amount of methanol were performed to obtain nonionic oligomers a601 to a606 (terminus: hydroxyl group) represented by general formula (G16). The number-average molecular weights of these oligomers are shown in Table 3.

[0308] The number-average molecular weights of the ionic oligomers a601 to a606 obtained from the synthesis of 6 batches showed considerable variation compared to the target number-average molecular weight.

[0309] [Table 3]

Claims

1. A block copolymer having one or more segments containing ionic groups (hereinafter referred to as "ionic segments") and one or more segments not containing ionic groups (hereinafter referred to as "nonionic segments"), wherein the ionic segments and the nonionic segments contain aromatic hydrocarbon polymers, and at least one of the ionic segments and the nonionic segments has a constituent unit made of an aromatic hydrocarbon polymer (hereinafter referred to as "constituent unit") and a first linker connecting the constituent units, A block copolymer for polymer electrolyte materials, wherein the first linker has a structure represented by any of the following general formulas (M1) to (M8), and the segment having the constituent unit and the first linker has a structure represented by the following general formula (C1). 【Chemistry 1】 (In general formulas (M1) to (M4), W to Z are independently H and NO.) ２ ,CN,CF ３ In general formula (M6), R represents a group selected from the group consisting of F, Cl, Br, and I. r1 to r4 each independently represent integers from 1 to 4. In general formula (M6), R represents any organic group; in general formula (M7), Ar represents any arylene group; and in general formula (M8), E represents an oxygen atom or a sulfur atom. General formulas (M1) to (M8) may be further substituted with electron-withdrawing groups. * represents a bonding site between general formulas (M1) to (M8) and the constituent unit. 【Chemistry 2】 In general formula (C1), A is a constituent unit, X is a structure represented by general formula (C2), and n is an integer greater than or equal to 1. In general formula (C2), A is a constituent unit, L1 is the first linker, and m is an integer greater than or equal to 1. If n is 2 or greater, the multiple values ​​of m may be the same or different from each other.

2. The block copolymer for polymer electrolyte material according to claim 1, wherein the ionic segment comprises the constituent units and a first linker connecting the constituent units.

3. The block copolymer for polymer electrolyte material according to claim 1 or 2, having alternating ionic segments and nonionic segments.

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

5. The block copolymer for polymer electrolyte materials according to any one of claims 1 to 4, wherein the ionic segment comprises an aromatic polyether structure.

6. The block copolymer for polymer electrolyte materials according to claim 5, wherein the ionic segment comprises an aromatic polyether ketone structure.

7. The block copolymer for polymer electrolyte materials according to any one of claims 1 to 6, wherein the ionic segment contains a structure represented by the following general formula (S1). 【Transformation 3】 (In general formula (S1), Ar １ ~Ar ４ Each of these independently represents a substituted or unsubstituted arylene group, and Ar １ ~Ar ４ At least one of them has an ionic group. １ and Y ２ 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 (S1) or another structure.

8. The block copolymer for polymer electrolyte materials according to claim 7, wherein the structure represented by the general formula (S1) is the structure represented by the following general formula (S2). 【Chemistry 4】 (In general formula (S2), Y １ and Y ２ each independently represents a ketone group or a protecting group that can be derived from a ketone group. M １ to M ４ each independently represents a hydrogen atom, a metal cation or an ammonium cation. n １ to n ４ each independently is 0 or 1, and at least one of n １ to n ４ is 1. * represents a bond to general formula (S2) or another structure.)

9. The block copolymer for polymer electrolyte materials according to any one of claims 1 to 8, wherein the nonionic segment comprises an aromatic polyether structure.

10. The block copolymer for polymer electrolyte materials according to claim 9, wherein the nonionic segment comprises an aromatic polyether ketone structure.

11. The block copolymer for polymer electrolyte materials according to any one of claims 1 to 10, wherein the nonionic segment contains a structure represented by the following general formula (S3). 【Transformation 5】 (In general formula (S3), Ar ５ ~Ar ８ Each of these independently represents an arylene group. However, Ar ５ ~Ar ８ None of them have ionic groups. 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 (S3) or another structure.

12. The block polymer for polymer electrolyte material according to claim 11, wherein the structure represented by the general formula (S3) is the structure represented by the following general formula (S4). 【Transformation 6】 (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 another structure.

13. A block copolymer for polymer electrolyte materials according to any one of claims 1 to 12, having a co-continuous phase separation structure.

14. A method for producing a block copolymer for polymer electrolyte materials according to any one of claims 1 to 13, comprising at least a step (1) of reacting a compound that provides the constituent units with a compound that provides the first linker.

15. A method for producing a block copolymer for a polymer electrolyte material according to claim 14, further comprising step (2) of reacting the compound obtained in step (1) with a compound that gives the other segment, after step (1).

16. A method for producing a block copolymer for a polymer electrolyte material according to claim 15, comprising step (1') before step (2) above, in which a compound that gives an ionic segment and a compound that gives a nonionic segment are reacted with a compound that gives a second linker to introduce a second linker to both ends of the compound that gives an ionic segment.

17. A method for producing a block copolymer for polymer electrolyte materials according to any one of claims 14 to 16, wherein the compound that gives the first linker and the second linker is represented by any one of the following general formulas (N1) to (N8). 【Transformation 7】 (In general formulas (N1) to (N8), V represents Cl or F. In general formulas (N1) to (N4), W to Z independently represent H and NO.) ２ ,CN,CF ３ In general formula (N6), R represents a group selected from the group consisting of F, Cl, Br, and I; r1 to r4 each independently represent an integer from 1 to 4; in general formula (N7), R represents any organic group; in general formula (N8), Ar represents any arylene group; and in general formula (N8), E represents an oxygen atom or a sulfur atom. General formulas (N1) to (N8) may be further substituted with electron-withdrawing groups.

18. A polymer electrolyte material comprising a block copolymer for polymer electrolyte materials according to any one of claims 1 to 13.

19. A polymer electrolyte molded article comprising the polymer electrolyte material according to claim 18.

20. A polymer electrolyte membrane comprising the polymer electrolyte material described in claim 18.

21. An electrolyte membrane with a catalyst layer, constructed using the polymer electrolyte material described in claim 18.

22. A membrane electrode composite comprising the polymer electrolyte material described in claim 18.

23. A solid polymer fuel cell comprising the polymer electrolyte material described in claim 18.

24. A water electrolysis type hydrogen generator configured using the polymer electrolyte material described in claim 18.

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