Polymer solid electrolyte membranes, polymer solid electrolyte membrane rolls, and fuel cells

Abstract

This invention provides a polymer solid electrolyte membrane with an improved balance of environmental compatibility and proton conductivity. [Solution] A polymer solid electrolyte membrane that is a self-supporting membrane and contains a polymer comprising the constituent unit (P) shown in formula (1) below. TIFF2026068846000028.tif86153 (In the formula, R 1 ~R 4 This includes organic groups having 1 to 70 carbon atoms, such as R, which contain one or more selected from sulfo groups, hydroxyl groups, and ether bonds. 1 ~R 4 At least one of them is a sulfo group, or an organic group containing a sulfo group.

Description

[Technical Field]

[0001] This invention relates to polymer solid electrolyte membranes, polymer solid electrolyte membrane rolls, and fuel cells. [Background technology]

[0002] Perfluorocarbon sulfonic acid-based polymer electrolyte membranes, such as Nafion (registered trademark), are used as polymer solid electrolyte membranes.

[0003] Patent Document 1 discloses a polymer solid electrolyte membrane for fuel cells that can operate stably even at high temperatures of 90°C or higher, characterized by containing a perfluorocarbon sulfonic acid polymer (a), a compound (b) having at least one amine from among primary and secondary amines in the same molecule, and / or a compound (c) having a tertiary amine in the same molecule and having at least one selected from sulfur, phosphorus, hydrazine, amide, phenolic hydroxyl group, primary amine, secondary amine, hydrogen bonded to a tertiary carbon, and halogen bonded to carbon. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2006-059552 [Overview of the project] [Problems that the invention aims to solve]

[0005] In recent years, there has been a growing demand to minimize the use of perfluoroalkyl compounds, such as perfluoroalkyl compounds and polyfluoroalkyl compounds, which have poor environmental compatibility, in products.

[0006] On the other hand, in the field of polymer solid electrolyte membranes used in fuel cells, polymers containing perfluoroalkyl groups are sometimes used from the viewpoint of proton conductivity.

[0007] This invention provides polymer solid electrolyte membranes, polymer solid electrolyte membrane rolls, and fuel cells with improved balance between environmental compatibility and proton conductivity. [Means for solving the problem]

[0008] The inventors diligently conducted research to solve the above problems. As a result, they discovered that a polymer solid electrolyte membrane, which is a self-supporting membrane containing a polymer with a norbornene skeleton and specific structural units having sulfo groups, can improve the balance between environmental compatibility and proton conductivity, and thus completed the present invention.

[0009] According to the present invention, the following polymer solid electrolyte membrane, polymer solid electrolyte membrane roll, and fuel cell are provided.

[0010] [1] The polymer contains the constituent unit (P) shown in the following formula (1), A self-supporting polymer solid electrolyte membrane. [ka] (In the above formula (1), p is 0, 1 or 2, R 1 ~R 4 Each independently represents a linear or branched organic group having 1 to 70 carbon atoms, containing one or more selected from the group consisting of a sulfo group, a hydroxyl group, and an ether bond, a linear or branched alkyl group having 1 to 70 carbon atoms, a hydrogen atom, a sulfo group, a hydroxyl group, or a halogen atom, in formula (1), R 1 ~R 4 At least one of these groups represents a sulfo group, or a linear or branched organic group with 1 to 70 carbon atoms containing a sulfo group. [2] In equation (1) above, R 1 ~R 4The polymer solid electrolyte membrane according to [1], wherein at least one of them contains an organic group represented by the following formula (2). [Chemical formula] (In the formula (2), X represents a linear or branched alkylene group having 1 to 20 carbon atoms, Y represents a linear or branched alkylene group having 1 to 20 carbon atoms, and n represents an integer of 1 or more.) [3] A polymer solid electrolyte membrane containing a polymer containing a structural unit (Q) represented by the following formula (3), In the IR spectrum measured for the polymer solid electrolyte membrane using a Fourier transform infrared spectrophotometer, 1300 cm -1 above 1400 cm -1 The maximum peak intensity in the following range is I SO , 2800 cm -1 above 3000 cm -1 The maximum peak intensity in the following range is I CH When it is, I SO / I CH The value of is 0.05 or more, A polymer solid electrolyte membrane that is a self-supporting film. [Chemical formula] (In the formula (3), q is 0, 1 or 2, and R 5 ~R 8 Each independently represents a linear or branched organic group having 1 to 70 carbon atoms containing one or more selected from the group consisting of a sulfo group, a hydroxy group and an ether bond, a linear or branched alkyl group having 1 to 20 carbon atoms, a hydrogen atom, a sulfo group, a hydroxy group or a halogen atom.) [4] A polymer solid electrolyte membrane containing a polymer that is a reaction product of a precursor polymer containing a structural unit (T) represented by the following formula (4) and a cyclic sulfonic acid ester, A polymer solid electrolyte membrane that is a self-supporting film. [Chemical formula] (In the formula (4), t is 0, 1 or 2, and R9 ~R 12 Each of these independently represents a linear or branched organic group having 1 to 10 carbon atoms containing at least one of a hydroxyl group and an ether bond, a linear or branched alkyl group having 1 to 10 carbon atoms, a hydrogen atom, a hydroxyl group, or a halogen atom, and in formula (4), R 9 ~R 12 At least one of these represents a hydroxyl group, or a linear or branched hydroxyalkyl group having 1 to 10 carbon atoms. [5] The polymer solid electrolyte membrane according to [4], wherein the cyclic sulfonic acid ester has a structure represented by the following formula (5). [ka] (In formula (5) above, Z represents a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms.) [6] The polymer solid electrolyte membrane according to any one of [1] to [3], further comprising a constituent unit (U) represented by the following formula (6). [ka] (In the above formula (6), u is 0, 1 or 2, R 13 ~R 16 Each of these independently represents a linear or branched organic group having 1 to 10 carbon atoms containing at least one of a hydroxyl group and an ether bond, a linear or branched alkyl group having 1 to 10 carbon atoms, a hydrogen atom, a hydroxyl group, or a halogen atom, and in formula (6), R 13 ~R 16 At least one of these represents a hydroxyl group, or a linear or branched hydroxyalkyl group having 1 to 10 carbon atoms. [7] The polymer further comprises a reaction product of the precursor polymer, the cyclic sulfonic acid ester, and a monomer represented by the following formula (7) as described in [4] or [5]. [ka] (In the above equation (7), v is 0, 1 or 2, R 17 ~R 20 Each of these independently represents a linear or branched organic group having 1 to 10 carbon atoms containing at least one of a hydroxyl group and an ether bond, a linear or branched alkyl group having 1 to 10 carbon atoms, a hydrogen atom, a hydroxyl group, or a halogen atom, and in formula (7), R 17 ~R 20 At least one of these represents a hydroxyl group, or a linear or branched hydroxyalkyl group having 1 to 10 carbon atoms. [8] A polymer solid electrolyte membrane according to any one of [1] to [7], wherein the content of perfluoroalkyl group constituent units in the polymer is 5.0 mol% or less when the total content of all constituent units in the polymer is 100.0 mol%. [9] The polymer solid electrolyte membrane according to any one of [1] to [8], wherein the fluorine content in the polymer solid electrolyte membrane is 5.0% by mass or less when the total amount of the polymer solid electrolyte membrane is 100.0% by mass.

[10] The polymer solid electrolyte membrane described above is cut to 10 mm x 60 mm and does not break when wrapped around a rod with a diameter of 1.33 mm and a curvature of 1.5, as described in any of [1] to [9].

[11] A polymer solid electrolyte membrane as described in any of [1] to

[10] , wherein the proton conductivity σ at a relative humidity of 90% and a temperature of 30°C, as measured by Method 1 below, is 5 mS / cm or more. (Method 1) The polymer solid electrolyte membrane is clamped in a jig and placed in a constant temperature and humidity chamber. An electrochemical measuring instrument is used to measure the resistance under the conditions of a measurement frequency of 1 to 500 kHz, a temperature of 30°C, and a humidity of 90% RH, and the proton conductivity σ (mS / cm) is calculated.

[12] A polymer solid electrolyte membrane according to any of [1] to

[11] , wherein the amount of warpage measured by method 2 below is 5.0 mm or less. (Method 2) The polymer solid electrolyte membrane is cut into a 4cm x 4cm square to prepare a test specimen. The test specimen is then placed on a flat plate and left to stand for 5 minutes. Next, the distance from each of the four vertices of the test specimen to the flat plate is measured, and the average value of these measurements is taken as the amount of warping (mm).

[13] A polymer solid electrolyte membrane as described in any of [1] to

[12] , having a thickness of 1 μm or more and 100 μm or less.

[14] A polymer solid electrolyte membrane, as described in any of [1] to

[13] , that can be used in a fuel cell.

[15] A polymer solid electrolyte membrane roll comprising a core having an outer surface, and a polymer solid electrolyte membrane according to any one of [1] to

[14] wrapped multiple times around the outer surface.

[16] The polymer solid electrolyte membrane roll according to

[15] , wherein the polymer solid electrolyte membrane is wound around the outer surface multiple times, with a release film provided on at least one side.

[17] A fuel cell comprising a polymer solid electrolyte membrane as described in any of [1] to

[14] . [Effects of the Invention]

[0011] According to the present invention, it is possible to provide polymer solid electrolyte membranes, polymer solid electrolyte membrane rolls, and fuel cells with improved balance between environmental compatibility and proton conductivity. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic diagram illustrating an example of the structure of the fuel cell in this embodiment. [Modes for carrying out the invention]

[0013] Embodiments of the present invention will be described in detail below with reference to the drawings. In the drawings, similar components are denoted by the same reference numerals, and explanations are omitted where appropriate. The drawings are for illustrative purposes only. The shapes and dimensional ratios of the components shown in the drawings do not necessarily correspond to those of actual items.

[0014] In this embodiment, "A~B" indicating a numerical range means A or greater and B or less, unless otherwise specified.

[0015] <First Embodiment> The polymer solid electrolyte membrane of the first embodiment comprises a polymer containing the constituent unit (P) shown in the following formula (1), and is a self-supporting membrane. In this specification, "self-supporting membrane" means a membrane that can maintain its shape as a membrane even without the presence of other support structures, at least over a predetermined area.

[0016] [ka]

[0017] In equation (1), p is 0, 1, or 2, and R 1 ~R 4 Each of these independently represents a linear or branched organic group having 1 to 70 carbon atoms, a linear or branched alkyl group having 1 to 70 carbon atoms, a hydrogen atom, a sulfo group, a hydroxyl group, or a halogen atom, each containing one or more selected from the group consisting of a sulfo group, a hydroxyl group, and an ether bond. In formula (1), R 1 ~R 4 At least one of these groups is a sulfo group, or a linear or branched organic group having 1 to 70 carbon atoms that contains a sulfo group.

[0018] According to our investigations, although the detailed mechanism is not clear, we have found that a polymer solid electrolyte membrane containing a polymer with a constituent unit (P) shown in formula (1) and being a self-supporting membrane can improve the balance between environmental compatibility and proton conductivity, thus completing the present invention.

[0019] The polymer solid electrolyte membrane of the first embodiment can be obtained by appropriately selecting the manufacturing procedure and manufacturing conditions. Preferably, the manufacturing procedure and manufacturing conditions involve polymerizing monomers having a norbornene skeleton on and / or within the substrate. Details of these will be described later.

[0020] <Constituent Unit (P)> In formula (1), p is preferably 0 or 1, and more preferably 0, from the viewpoint of further improving the balance between environmental compatibility and proton conductivity performance.

[0021] In formula (1), R 1 ~R 4 From the viewpoint of further improving the balance of environmental compatibility and proton conductivity performance, each is independently preferably a linear or branched organic group having 1 to 70 carbon atoms containing one or more selected from the group consisting of a sulfo group and an ether bond, a linear or branched alkyl group having 1 to 70 carbon atoms, a hydrogen atom, or a sulfo group; more preferably a linear or branched organic group having 1 to 70 carbon atoms containing one or more selected from the group consisting of a sulfo group and an ether bond, or a hydrogen atom; and even more preferably a linear organic group having 1 to 70 carbon atoms containing a sulfo group and an ether bond, or a hydrogen atom.

[0022] In formula (1), R 1 ~R 4 At least one of these is preferably a linear or branched organic group having 1 to 70 carbon atoms containing a sulfo group, more preferably a branched organic group having 1 to 70 carbon atoms containing a sulfo group, and even more preferably an organic group represented by the following formula (2).

[0023] [ka]

[0024] In formula (2), X represents a linear or branched alkylene group having 1 to 20 carbon atoms, Y represents a linear or branched alkylene group having 1 to 20 carbon atoms, and n represents an integer of 1 or more.

[0025] In formula (2), X is preferably a linear alkylene group having 1 to 20 carbon atoms, more preferably a linear alkylene group having 1 to 10 carbon atoms, even more preferably a linear alkylene group having 2 to 6 carbon atoms, and even more preferably a linear alkylene group having 3 to 5 carbon atoms, from the viewpoint of further improving the balance of flexibility, environmental compatibility, and proton conductivity.

[0026] In formula (2), Y is preferably a linear alkylene group having 1 to 20 carbon atoms, more preferably a linear alkylene group having 1 to 10 carbon atoms, even more preferably a linear alkylene group having 1 to 6 carbon atoms, and even more preferably a linear alkylene group having 2 to 4 carbon atoms, from the viewpoint of further improving the balance of flexibility, environmental compatibility, and proton conductivity.

[0027] In formula (2), n is preferably 1 to 10, more preferably 1 to 7, and even more preferably 1 to 5, from the viewpoint of further improving the balance of flexibility, environmental compatibility, and proton conductivity.

[0028] <Second Embodiment> The polymer solid electrolyte membrane of the second embodiment comprises a polymer containing the constituent unit (Q) shown in the following formula (3), and in the IR spectrum measured using a Fourier transform infrared spectrophotometer, it has a wavelength of 1300 cm⁻¹. -1 More than 1400cm -1 The maximum peak intensity within the following range is I SO , 2800cm -1 More than 3000cm -1 The maximum peak intensity within the following range is I CH In that case, I SO / I CH The value is 0.05 or higher, indicating that it is a self-supporting membrane.

[0029] [ka]

[0030] In equation (3), q is 0, 1, or 2, and R 5 ~R 8 Each of these independently represents a linear or branched organic group having 1 to 70 carbon atoms, a linear or branched alkyl group having 1 to 20 carbon atoms, a hydrogen atom, a sulfo group, a hydroxyl group, or a halogen atom, all containing one or more selected from the group consisting of a sulfo group, a hydroxyl group, and an ether bond.

[0031] According to the inventors' investigation, although the detailed mechanism is unclear, the polymer contains the constituent unit (Q) shown in formula (3), and in the IR spectrum measured using a Fourier transform infrared spectrophotometer, 1300 cm⁻¹ -1 More than 1400cm -1 The maximum peak intensity within the following range is I SO , 2800cm -1 More than 3000cm -1 The maximum peak intensity within the following range is I CH In that case, I SO / I CH The present invention was completed by discovering that a polymer solid electrolyte membrane, which is a self-supporting membrane, can improve the balance between environmental compatibility and proton conductivity, as the value of is 0.05 or higher.

[0032] The polymer solid electrolyte membrane of the second embodiment can be obtained by appropriately selecting the manufacturing procedure and manufacturing conditions. Preferably, the manufacturing procedure and manufacturing conditions involve polymerizing monomers having a norbornene skeleton on and / or within the substrate. Details of these will be described later.

[0033] <Constituent Unit (Q)> In formula (3), q is preferably 0 or 1, and more preferably 0, from the viewpoint of further improving the balance between environmental compatibility and proton conductivity performance.

[0034] In formula (3), R5 ~R 8 From the viewpoint of further improving the balance of environmental compatibility and proton conductivity performance, each is independently preferably a linear or branched organic group having 1 to 70 carbon atoms containing one or more selected from the group consisting of a sulfo group and an ether bond, a linear or branched alkyl group having 1 to 70 carbon atoms, a hydrogen atom, or a sulfo group; more preferably a linear or branched organic group having 1 to 70 carbon atoms containing one or more selected from the group consisting of a sulfo group and an ether bond, or a hydrogen atom; and even more preferably a linear organic group having 1 to 70 carbon atoms containing a sulfo group and an ether bond, or a hydrogen atom.

[0035] <IRスペクトル> The polymer solid electrolyte membrane of the second embodiment exhibits an IR spectrum of 1300 cm⁻¹ measured using a Fourier transform infrared spectrophotometer. -1 More than 1400cm -1 The maximum peak intensity within the following range is I SO , 2800cm -1 More than 3000cm -1 The maximum peak intensity within the following range is I CH In that case, I SO / I CH The value of is 0.05 or higher, preferably 0.10 or higher, more preferably 0.15 or higher, even more preferably 0.20 or higher, even more preferably 0.25 or higher, and even more preferably 0.30 or higher. SO / I CH There is no particular upper limit to the value of , but it may be 1.00 or less, 0.60 or less, or 0.40 or less.

[0036] The polymer solid electrolyte membrane of the second embodiment exhibits an IR spectrum of 1300 cm⁻¹ measured using a Fourier transform infrared spectrophotometer. -1 More than 1400cm -1 The maximum peak intensity within the following range is I SO , 2800cm -1 More than 3000cm -1 The maximum peak intensity within the following range is I CHIn that case, I SO / I CH The value of is preferably 0.05 or more and 1.00 or less, more preferably 0.10 or more and 1.00 or less, more preferably 0.15 or more and 1.00 or less, even more preferably 0.20 or more and 1.00 or less, even more preferably 0.25 or more and 0.60 or less, and even more preferably 0.30 or more and 0.40 or less.

[0037] <Third Embodiment> The polymer solid electrolyte membrane of the third embodiment comprises a polymer which is a reaction product of a precursor polymer containing the constituent unit (T) shown in the following formula (4) and a cyclic sulfonic acid ester, and is a self-supporting membrane.

[0038] [ka]

[0039] In equation (4), t is 0, 1, or 2, and R 9 ~R 12 Each of these independently represents a linear or branched organic group having 1 to 10 carbon atoms containing at least one of a hydroxyl group and / or an ether bond, a linear or branched alkyl group having 1 to 10 carbon atoms, a hydrogen atom, a hydroxyl group, or a halogen atom, in formula (4), R 9 ~R 12 At least one of these represents a hydroxyl group or a linear or branched hydroxyalkyl group having 1 to 10 carbon atoms.

[0040] According to our investigations, although the detailed mechanism is not clear, we have found that a polymer solid electrolyte membrane, which is a self-supporting membrane containing a polymer that is a reaction product of a precursor polymer containing the constituent unit (T) shown in formula (4) and a cyclic sulfonic acid ester, can improve the balance of environmental compatibility and proton conductivity performance, and have completed the present invention.

[0041] The polymer solid electrolyte membrane of the third embodiment can be obtained by appropriately selecting the manufacturing procedure and manufacturing conditions. Preferably, the manufacturing procedure and manufacturing conditions involve polymerizing monomers having a norbornene skeleton on and / or within the substrate. Details of these will be described later.

[0042] <Constituent Unit (T)> In formula (4), t is preferably 0 or 1, and more preferably 0, from the viewpoint of further improving the balance between environmental compatibility and proton conductivity performance.

[0043] In formula (4), R 9 ~R 12 From the viewpoint of further improving the balance between environmental compatibility and proton conductivity, each element is preferably, independently, a linear or branched organic group having 1 to 10 carbon atoms containing a hydroxyl group, a linear or branched alkyl group having 1 to 10 carbon atoms, a hydrogen atom, or a hydroxyl group; more preferably, a linear or branched organic group having 1 to 10 carbon atoms containing a hydroxyl group or a hydrogen atom; and even more preferably, a linear or branched organic group having 2 to 6 carbon atoms containing a hydroxyl group or a hydrogen atom.

[0044] In formula (4), R 9 ~R 12 At least one of these is preferably a linear or branched hydroxyalkyl group having 1 to 10 carbon atoms, more preferably a linear hydroxyalkyl group having 2 to 6 carbon atoms, and even more preferably a linear hydroxyalkyl group having 3 to 5 carbon atoms, from the viewpoint of further improving the balance of flexibility, environmental compatibility, and proton conductivity.

[0045] In the constituent unit (T), R 9 ~R 12 The total number of organic groups containing hydroxyl groups and hydroxyl groups is preferably 1 to 3, more preferably 1 to 2, and even more preferably 1, from the viewpoint of further improving the balance between environmental compatibility and proton conductivity performance.

[0046] In the constituent unit (T), the total number of hydroxyl groups is preferably 1 to 6, more preferably 1 to 4, even more preferably 1 to 2, and still more preferably 1, from the viewpoint of further improving the balance of environmental compatibility and proton conductivity performance.

[0047] <Cyclic sulfonic acid ester> The cyclic sulfonic acid ester of the third embodiment preferably has the structure represented by the following formula (5) from the viewpoint of further improving the balance of performance in terms of flexibility, environmental compatibility, and proton conductivity.

[0048] [ka]

[0049] In formula (5), Z represents a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms.

[0050] In formula (5), Z is preferably an unsubstituted alkylene group having 1 to 10 carbon atoms, more preferably an unsubstituted alkylene group having 1 to 6 carbon atoms, and even more preferably an unsubstituted alkylene group having 2 to 4 carbon atoms, from the viewpoint of further improving the balance of flexibility, environmental compatibility, and proton conductivity.

[0051] <Constituent Unit (U)> The polymer in the polymer solid electrolyte membrane of the first and second embodiments preferably further comprises a constituent unit (U) represented by the following formula (6).

[0052] [ka]

[0053] In equation (6), u is 0, 1, or 2, and R 13 ~R 16each independently represents a linear or branched organic group having 1 to 10 carbon atoms containing at least one of a hydroxy group and an ether bond, a linear or branched alkyl group having 1 to 10 carbon atoms, a hydrogen atom, a hydroxy group or a halogen atom, and in formula (6), R 13 ~R 16 at least one of them represents a hydroxy group or a linear or branched hydroxyalkyl group having 1 to 10 carbon atoms.

[0054] In formula (6), u is preferably 0 or 1, more preferably 0, from the viewpoint of further improving the balance of environmental compatibility and proton conductivity performance.

[0055] In formula (6), R 13 ~R 16 each independently is preferably a linear or branched organic group having 1 to 10 carbon atoms containing a hydroxy group, a linear or branched alkyl group having 1 to 10 carbon atoms, a hydrogen atom or a hydroxy group, more preferably a linear or branched organic group having 1 to 10 carbon atoms containing a hydroxy group or a hydrogen atom, still more preferably a linear or branched organic group having 2 to 6 carbon atoms containing a hydroxy group or a hydrogen atom, from the viewpoint of further improving the balance of environmental compatibility and proton conductivity performance.

[0056] In formula (6), at least one of R 13 ~R 16 is preferably a linear or branched hydroxyalkyl group having 1 to 10 carbon atoms, more preferably a linear hydroxyalkyl group having 2 to 6 carbon atoms, still more preferably a linear hydroxyalkyl group having 3 to 5 carbon atoms, from the viewpoint of further improving the balance of flexibility, environmental compatibility and proton conductivity performance.

[0057] In the structural unit (U), R 13 ~R 16The total number of organic groups containing hydroxyl groups and hydroxyl groups is preferably 1 to 3, more preferably 1 to 2, and even more preferably 1, from the viewpoint of further improving the balance between environmental compatibility and proton conductivity performance.

[0058] In the constituent unit (U), the total number of hydroxyl groups is preferably 1 to 6, more preferably 1 to 4, even more preferably 1 to 2, and still more preferably 1, from the viewpoint of further improving the balance of environmental compatibility and proton conductivity performance.

[0059] <Constituent unit (S1), Constituent unit (S2)> From the viewpoint of further improving flexibility, the polymer in the polymer solid electrolyte membrane of the first embodiment may further include a constituent unit (S1) having a structure in which a sulfo group in the constituent unit (P) is bonded to the carbon-carbon double bond of norbornene in the monomer (s) containing norbornene. The polymer in the polymer solid electrolyte membrane of the second embodiment may further include a constituent unit (S2) having a structure in which a sulfo group in the constituent unit (Q) is bonded to the carbon-carbon double bond of norbornene in the norbornene-containing monomer (s). The monomer(s) may further contain one or more selected from the group consisting of a sulfo group, a sulfonyl group, and a hydroxyl group.

[0060] Based on these considerations, the constituent unit (S1) of the first embodiment and the constituent unit (S2) of the second embodiment may include a multi-branch structure such as the one shown below, from the viewpoint of further improving flexibility.

[0061] [ka]

[0062] <Reaction product of precursor polymer, cyclic sulfonic acid ester, and monomer> The polymer in the polymer solid electrolyte membrane of the third embodiment preferably further contains a reaction product of a precursor polymer, a cyclic sulfonic acid ester, and a monomer represented by the following formula (7) from the viewpoint of further improving flexibility. [Chemical formula]

[0063] In formula (7), v is 0, 1 or 2, and R 17 ~R 20 each independently represents a linear or branched organic group having 1 to 10 carbon atoms containing at least one of a hydroxy group and an ether bond, a linear or branched alkyl group having 1 to 10 carbon atoms, a hydrogen atom, a hydroxy group or a halogen atom. In formula (7), at least one of R 17 ~R 20 represents a hydroxy group or a linear or branched hydroxyalkyl group having 1 to 10 carbon atoms.

[0064] In formula (7), v is preferably 0 or 1, more preferably 0, from the viewpoint of further improving the performance balance between environmental compatibility and proton conductivity.

[0065] In formula (7), R 17 ~R 20 each independently is preferably, from the viewpoint of further improving the performance balance between environmental compatibility and proton conductivity, a linear or branched organic group having 1 to 10 carbon atoms containing a hydroxy group, a linear or branched alkyl group having 1 to 10 carbon atoms, a hydrogen atom or a hydroxy group, more preferably a linear or branched organic group having 1 to 10 carbon atoms containing a hydroxy group or a hydrogen atom, and still more preferably a linear or branched organic group having 2 to 6 carbon atoms containing a hydroxy group or a hydrogen atom.

[0066] In formula (7), R 17 ~R 20At least one of these is preferably a linear or branched hydroxyalkyl group having 1 to 10 carbon atoms, more preferably a linear hydroxyalkyl group having 2 to 6 carbon atoms, and even more preferably a linear hydroxyalkyl group having 3 to 5 carbon atoms, from the viewpoint of further improving the balance of flexibility, environmental compatibility, and proton conductivity.

[0067] In the preset, R 17 ~R 20 The total number of organic groups containing hydroxyl groups and hydroxyl groups is preferably 1 to 3, more preferably 1 to 2, and even more preferably 1, from the viewpoint of further improving the balance between environmental compatibility and proton conductivity performance.

[0068] In the monomer, the total number of hydroxyl groups is preferably 1 to 6, more preferably 1 to 4, even more preferably 1 to 2, and still more preferably 1, from the viewpoint of further improving the balance between environmental compatibility and proton conductivity.

[0069] The following describes the features common to the polymer solid electrolyte membranes of the first, second, and third embodiments.

[0070] From the viewpoint of further improving the balance of environmental compatibility and proton conductivity, the content of perfluoroalkyl group constituent units in the polymer of this embodiment is preferably 5.0 mol% or less, more preferably 3.0 mol% or less, even more preferably 1.0 mol% or less, even more preferably 0.5 mol% or less, even more preferably 0.1 mol% or less, even more preferably 0.01 mol% or less, and even more preferably 0.001 mol% or less, when the total content of all constituent units in the polymer is 100.0 mol%. The lower limit of the content of perfluoroalkyl group constituent units in the polymer of this embodiment is not particularly limited, but may be, for example, 0 mol% or more.

[0071] From the viewpoint of further improving the balance of environmental compatibility and proton conductivity performance, the content of perfluoroalkyl group constituent units in the polymer of this embodiment is preferably 0 mol% to 5.0 mol%, more preferably 0 mol% to 3.0 mol%, even more preferably 0 mol% to 1.0 mol%, even more preferably 0 mol% to 0.5 mol%, even more preferably 0 mol% to 0.1 mol%, even more preferably 0 mol% to 0.01 mol%, and even more preferably 0 mol% to 0.001 mol%, when the total content of all constituent units in the polymer is 100.0 mol%.

[0072] In this embodiment, the fluorine content in the polymer solid electrolyte membrane is preferably 5.0% by mass or less, more preferably 3.0% by mass or less, even more preferably 1.0% by mass or less, even more preferably 0.5% by mass or less, and even more preferably 0.1% by mass or less, when the total amount of the polymer solid electrolyte membrane is 100.0% by mass, from the viewpoint of further improving the balance of environmental compatibility and proton conductivity performance. The lower limit of the fluorine content in the polymer solid electrolyte membrane in this embodiment is not particularly limited, but for example, it may be 0% by mass or more.

[0073] From the viewpoint of further improving the balance between environmental compatibility and proton conductivity, the fluorine content in the polymer solid electrolyte membrane of this embodiment is preferably 0% to 5.0% by mass, more preferably 0% to 3.0% by mass, even more preferably 0% to 1.0% by mass, even more preferably 0% to 0.5% by mass, and even more preferably 0% to 0.1% by mass, when the total amount of the polymer solid electrolyte membrane is 100.0% by mass.

[0074] In this embodiment, the following methods can be used to measure the fluorine content in the polymer solid electrolyte membrane. First, approximately 10 mg of polymer solid electrolyte membrane is completely combusted in a sealed flask with oxygen substituted in. The resulting gas is collected in a pre-added hydrogen peroxide alkaline absorption solution in the flask, and the volume is adjusted to 50 mL to obtain the test solution. Next, the test solution and standard solution are introduced into an ion chromatograph, and the fluoride ion concentration is determined using the calibration curve method to calculate the fluorine content in the sample.

[0075] From the viewpoint of further improving the balance of environmental compatibility and proton conductivity, the content of the polymer of this embodiment in the polymer solid electrolyte membrane of this embodiment is preferably 50.0% by mass or more and 100.0% by mass or less, more preferably 80.0% by mass or more and 100.0% by mass or less, even more preferably 90.0% by mass or more and 100.0% by mass or less, even more preferably 95.0% by mass or more and 100.0% by mass or less, and even more preferably 99.0% by mass or more and 100.0% by mass or less.

[0076] The polymer solid electrolyte membrane of this embodiment may further include fibrous substrates such as nonwoven fabrics, or porous substrates formed by stretching or the like, from the viewpoint of further improving mechanical strength.

[0077] <thickness> The thickness of the polymer solid electrolyte membrane in this embodiment is preferably 1 μm to 100 μm, more preferably 10 μm to 90 μm, even more preferably 30 μm to 80 μm, even more preferably 40 μm to 75 μm, even more preferably 50 μm to 70 μm, and even more preferably 55 μm to 65 μm.

[0078] <Mechanical strength> In this embodiment, the polymer solid electrolyte membrane, from the viewpoint of further improving mechanical strength, preferably does not break when cut to 10 mm x 60 mm and wrapped around a rod with a diameter of 1.33 mm and a curvature of 1.5.

[0079] <Proton conductivity> The proton conductivity σ of the polymer solid electrolyte membrane of this embodiment, measured by Method 1 below at a relative humidity of 90% and a temperature of 30°C, is preferably 5 mS / cm or more, more preferably 8 mS / cm or more, even more preferably 10 mS / cm or more, even more preferably 12 mS / cm or more, even more preferably 14 mS / cm or more, even more preferably 16 mS / cm or more, and even more preferably 18 mS / cm or more, from the viewpoint of further improving proton conductivity. The upper limit of the above proton conductivity σ is not particularly limited, but for example it may be 40 mS / cm or less, 30 mS / cm or less, 25 mS / cm or less, or 22 mS / cm or less. (Method 1) A polymer solid electrolyte membrane is clamped in a jig and placed in a constant temperature and humidity chamber. Using an electrochemical measuring instrument, the resistance value is measured under the conditions of a measurement frequency of 1 to 500 kHz, a temperature of 30°C, and a humidity of 90% RH, and the proton conductivity σ (mS / cm) is calculated.

[0080] The proton conductivity σ of the polymer solid electrolyte membrane of this embodiment, measured by Method 1 above at a relative humidity of 90% and a temperature of 30°C, is preferably 5 mS / cm to 40 mS / cm, more preferably 8 mS / cm to 40 mS / cm, even more preferably 10 mS / cm to 40 mS / cm, even more preferably 12 mS / cm to 40 mS / cm, even more preferably 14 mS / cm to 30 mS / cm, even more preferably 16 mS / cm to 25 mS / cm, and even more preferably 18 mS / cm to 22 mS / cm, from the viewpoint of further improving proton conductivity.

[0081] <Amount of curvature> The amount of warpage of the polymer solid electrolyte membrane of this embodiment, as measured by the method 2 described below, is preferably 5.0 mm or less, more preferably 4.0 mm or less, even more preferably 3.0 mm or less, even more preferably 2.0 mm or less, even more preferably 1.5 mm or less, and even more preferably 1.0 mm or less, from the viewpoint of further improving flexibility. The lower limit of the above amount of warpage is not particularly limited, but for example it may be 0.1 mm or more, or 0.5 mm or more. (Method 2) A polymer solid electrolyte membrane is cut into 4cm x 4cm squares to prepare test specimens. The test specimens are then placed on a flat plate and left to stand for 5 minutes. Next, the distance from each of the four vertices of the test specimen to the flat plate is measured, and the average value of these measurements is taken as the amount of warping (mm).

[0082] The amount of warpage of the polymer solid electrolyte membrane of this embodiment, as measured by method 2 above, is preferably 0.1 mm to 5.0 mm, more preferably 0.1 mm to 4.0 mm, even more preferably 0.1 mm to 3.0 mm, even more preferably 0.1 mm to 2.0 mm, even more preferably 0.1 mm to 1.5 mm, and even more preferably 0.5 mm to 1.0 mm, from the viewpoint of further improving flexibility.

[0083] <Application> The polymer solid electrolyte membrane of this embodiment is a self-supporting membrane and has an improved balance of environmental compatibility and proton conductivity, making it suitable for use in fuel cells. The polymer solid electrolyte membrane of this embodiment can preferably be used in a membrane-electrode assembly (MEA) in a fuel cell, either as a solid electrolyte membrane or as a binder that joins the catalyst layer and the solid electrolyte membrane.

[0084] <Method for manufacturing polymer solid electrolyte membranes> The polymer solid electrolyte membrane of this embodiment can be obtained by appropriately selecting the manufacturing procedure, manufacturing conditions, etc. Specifically, the manufacturing method of the polymer solid electrolyte membrane of this embodiment is preferably as follows: Step (A) involves polymerizing a monomer having a norbornene skeleton on and / or inside a substrate to obtain a precursor polymer film, Step (B) involves impregnating a precursor polymer film with a cyclic sulfonic acid ester solution, and then reacting the precursor polymer film with the cyclic sulfonic acid ester to obtain a polymer solid electrolyte membrane. This includes the above. Furthermore, the method for producing a polymer solid electrolyte membrane according to this embodiment may include additional steps other than those mentioned above.

[0085] <Process (A)> In step (A) of this embodiment, a monomer having a norbornene skeleton is polymerized on and / or inside the substrate to obtain a precursor polymer film. This further improves the mechanical strength of the resulting polymer solid electrolyte membrane, making it possible to obtain a polymer solid electrolyte membrane that is self-supporting.

[0086] In step (A) of this embodiment, the substrate used is not particularly limited. For example, an impermeable rigid substrate such as a silicon wafer, glass wafer, or easily bondable PET, or a porous soft substrate such as polyethylene nonwoven fabric or aramid nonwoven fabric can be used. In step (A) of this embodiment, as a method for polymerizing monomers having a norbornene skeleton on and / or inside the substrate, from the viewpoint of further improving mechanical strength, it is preferable to apply a solution obtained by mixing the monomer and the polymerization catalyst by stirring to the substrate on and / or inside the substrate, and then heat by vacuum drying to polymerize the monomer on and / or inside the substrate.

[0087] In step (A) of this embodiment, the polymerization catalyst used for monomer polymerization is not particularly limited, but preferably contains a palladium cation and a weakly coordinating anion, and more preferably contains Pd-1206 and DANFABA (N,N-dimethylanilinium tetrakis(pentafluorophenyl) borate) represented by the following formula.

[0088] [ka]

[0089] In step (A) of this embodiment, the temperature at which the monomer and polymerization catalyst are stirred is preferably 40°C to 80°C, and more preferably 50°C to 70°C, from the viewpoint of further improving mechanical strength.

[0090] In step (A) of this embodiment, the time for stirring the monomer and polymerization catalyst is preferably 0.5 hours or more and 2 hours or less, and more preferably 0.5 hours or more and 1.5 hours or less, from the viewpoint of further improving mechanical strength.

[0091] In step (A) of this embodiment, the method for applying the solution of monomer and polymerization catalyst mixed together onto and / or inside the substrate is not particularly limited, but spin coating is one example.

[0092] In step (A) of this embodiment, the temperature at which the mixed solution of monomer and polymerization catalyst applied to the substrate and / or inside the substrate is heated is preferably 40°C to 80°C, more preferably 50°C to 70°C, from the viewpoint of further improving mechanical strength.

[0093] In step (A) of this embodiment, the time for heating the mixed solution of monomer and polymerization catalyst applied to the substrate and / or inside the substrate is preferably 5 hours or more and 10 hours or less, more preferably 6 hours or more and 8 hours or less, from the viewpoint of further improving mechanical strength.

[0094] <Process (B)> In step (B) of this embodiment, the precursor polymer film obtained in step (A) is impregnated with a cyclic sulfonic acid ester solution, and then the precursor polymer film and the cyclic sulfonic acid ester are reacted to obtain a polymer solid electrolyte membrane. Monomers having a norbornene skeleton cannot efficiently introduce sulfo groups into their side chains by reaction with cyclic sulfonic acid esters in their monomer state. Therefore, by reacting the precursor polymer film with the cyclic sulfonic acid ester in step (B), sulfo groups can be efficiently introduced into the side chains of the norbornene skeleton, thereby further improving the balance between environmental compatibility and proton conductivity.

[0095] In step (B) of this embodiment, the temperature at which the precursor polymer film and the cyclic sulfonic acid ester are reacted is preferably 90°C to 130°C, more preferably 100°C to 120°C, from the viewpoint of further improving the balance between environmental compatibility and proton conductivity.

[0096] In step (B) of this embodiment, the reaction time between the precursor polymer film and the cyclic sulfonic acid ester is preferably 3 hours to 7 hours, more preferably 4 hours to 6 hours, from the viewpoint of further improving the balance between environmental compatibility and proton conductivity.

[0097] <The process immediately preceding process (B)> In the step immediately preceding step (B) of this embodiment, from the viewpoint of further improving flexibility, preferably, a step of peeling the precursor polymer film from the substrate is further included. This makes it easier for the reaction between the precursor polymer film and the cyclic sulfonic acid ester to proceed evenly on both sides of the precursor polymer film in step (B), thereby further improving flexibility.

[0098] In the step immediately preceding step (B) of this embodiment, it is preferable not to immerse the material in alcohol such as ethanol, from the viewpoint of further improving flexibility. As a result, monomers remain on the precursor polymer film, and in step (B), a reaction occurs in which the remaining monomers combine with sulfo groups in the precursor polymer film. As a result, the polymer in the resulting polymer solid electrolyte membrane contains a highly branched structure, which can further improve flexibility.

[0099] In step (B) of this embodiment, the amount of residual monomer in the precursor polymer film is preferably 5 mol% to 15 mol%, and more preferably 8 mol% to 12 mol%, when the total amount of monomer used is considered to be 100 mol%, from the viewpoint of further improving flexibility.

[0100] In this embodiment, the amount of residual monomers in the precursor polymer film can be determined, for example, by quantifying norbornene butanol contained in the cleaning solution when the precursor polymer film is cleaned with ethanol under the following conditions using a GC measuring device. <GC measurement conditions> · Carrier gas: N2 · Detector: Flame ionization detector (FID), FID temperature: 300 °C · Column: SH-RXi-1HT (manufactured by Shimadzu Corporation, inner diameter 0.25, length 30 m, film thickness 0.25 μm) · Vaporization chamber temperature: 210 °C · Column flow rate: 0.64 mL / min · Column temperature rising condition: Hold at 50 °C for 5 min, raise the temperature to 300 °C at 20 °C / min, hold at 300 °C for 10 min

[0101] <Polymer solid electrolyte membrane roll> The polymer solid electrolyte membrane roll of this embodiment includes a core having an outer peripheral surface and the polymer solid electrolyte membrane of this embodiment wound around the outer peripheral surface a plurality of times. The polymer solid electrolyte membrane of this embodiment is a self-supporting membrane and has mechanical strength such that it can maintain its shape as a membrane even without the presence of other supports. Therefore, in the polymer solid electrolyte membrane roll of this embodiment, preferably, it does not break even when wound around the outer peripheral surface of the core a plurality of times.

[0102] From the perspective of further improving the releasability, the polymer solid electrolyte membrane roll of this embodiment is preferably wound around the outer peripheral surface a plurality of times in a state where the polymer solid electrolyte membrane is provided with a release film on at least one side, and more preferably, wound around the outer peripheral surface a plurality of times in a state where the polymer solid electrolyte membrane is provided with release films on both sides. Thereby, since the surfaces of the polymer solid electrolyte membranes do not contact each other, the releasability can be further improved.

[0103] The core of the polymer solid electrolyte membrane roll of this embodiment is not particularly limited. For example, it may be a paper tube. Further, the polymer solid electrolyte membrane roll of this embodiment may be provided with a packaging cylinder on the outermost peripheral surface.

[0104] <Fuel cell> The fuel cell of this embodiment is equipped with the polymer solid electrolyte membrane of this embodiment. Since the polymer solid electrolyte membrane of this embodiment has an improved balance of environmental compatibility and proton conductivity, the fuel cell of this embodiment has an improved balance of environmental compatibility and proton conductivity.

[0105] The fuel cell of this embodiment will be described below using Figure 1, a schematic diagram illustrating an example of the structure of the fuel cell of this embodiment.

[0106] A single cell 10 comprises a pair of separators 1 and a membrane-electrode assembly (MEA) 4 sandwiched between the separators 1. The membrane-electrode assembly 4 is a laminate in which catalyst layers 2 (2a, 2b) and a gas diffusion layer 11 are laminated and bonded in that order to each surface of the polymer solid electrolyte membrane 3 of this embodiment. The combination of the catalyst layer 2 and the gas diffusion layer 11 constitutes the anode and cathode (electrode).

[0107] By supplying hydrogen or methanol to the anode side (between separator 1 and gas diffusion layer 11) and oxygen or air to the cathode side (between the other separator 1 and gas diffusion layer 11), and connecting an external load circuit between the anode and cathode, the single cell 10 operates as a battery. Protons generated by the catalytic reaction at the anode move to the cathode through the polymer solid electrolyte membrane 3, where they react with oxygen to produce water.

[0108] The type of gas diffusion layer 11 is not limited as long as it is suitable for use in fuel cells, and examples include those made of porous carbon material.

[0109] As the catalyst layer 2, for example, a metal-based catalyst (preferably a noble metal-based catalyst) or a non-metallic catalyst supported on an electrically conductive carrier is used, and a noble metal-based catalyst is preferred. The carrier is preferably carbon material particles (carbon particles) such as carbon black. For the noble metal-based catalyst, the anode side is preferably metal particles containing platinum group metals (PGMs), such as platinum catalysts, ruthenium catalysts, and ruthenium-platinum alloy catalysts, and the cathode side is preferably metal particles such as platinum catalysts.

[0110] Although the present invention has been described above, it is not limited thereto. For example, any components may be added to the polymer solid electrolyte membrane and the polymer solid electrolyte membrane roll. Also, any structure may be added to the fuel cell. [Examples]

[0111] Embodiments of the present invention will be described in detail based on examples and comparative examples. However, the present invention is not limited to these examples.

[0112] <Synthesis of monomers> Allyl acetate and dicyclopentadiene (DCPD) were added to a suitable high-pressure tube reactor in a molar ratio of 4:1 relative to cyclopentadiene monomer. The high-pressure tube reactor was then heated in a hot oil bath maintained at 220°C for 4 hours. The high-pressure tube reactor was then removed from the bath and rapidly cooled in a wet ice bath to obtain a crude mixture. The crude mixture was then fractionally distilled to isolate norbornene methyl acetate (purity ≥ 99.6%).

[0113] The mixture of norbornene methyl acetate (4.8 kg) and 1-butanol (11.2 kg) was added to a jacketed reactor of appropriate size equipped with a stirrer, a top condenser, a top condensate receiving tank, and a feed tank with a metering pump. Next, the reactor was purged with nitrogen three times under pressurized / depressurized conditions to remove oxygen from the upper space of the reactor. The reactor was then completely ventilated to the top and receiving tank systems, and then heated to the initial reaction temperature (45°C). Next, a catalyst solution (25 wt%, 0.125 kg) of sodium methoxide dissolved in 1-butanol was added to the glass feed tank and then metered and supplied to the reactor over 15 minutes (addition rate 8.33 g / min), during which the reactor temperature was maintained (45°C). After the metering and addition of the catalyst was completed, the reactor was maintained at 45°C for a further 1.75 hours.

[0114] Next, the reactor was heated to the solvent stripping temperature (60-68°C) with aeration, and a mixture of 1-butanol and methyl acetate (4 kg) was flushed from the top of the column and collected in a condensate receiving tank. Then, an additional 1-butanol (4 kg) was transferred to the reactor, and a second solvent stripping operation was performed to remove the mixture of 1-butanol and methyl acetate (4 kg). Next, a third solvent stripping operation was performed to remove the mixture of 1-butanol and methyl acetate (6 kg). Then, acetic acid (0.04 kg) was added to the reaction concentrate to obtain a norbornene-butanol reaction concentrate.

[0115] Next, the norbornenebutanol reaction concentrate (6 kg) was charged into a vacuum distillation system equipped with appropriate equipment, consisting of an electrically heated mantle-equipped distillation pot, a distillation column with stainless steel packing (4 theoretical stages), a reflux separator, a water-cooled condenser, a top condensate receiving tank, and a vacuum pump, and fractional distillation was performed. After removing the initial top fraction, norbornenebutanol was top-distilled under conditions of a top temperature of 70-75°C, reduced pressure (4-5 mmHg), and a reflux ratio of 2:1 to obtain norbornenebutanol (bicyclo[2.2.1]hept-5-ene-2-butanol) represented by the following formula in high purity (≧99.8% assay).

[0116] [Chemical]

[0117] [Preparation of Polymer Solid Electrolyte Membrane] (Example 1) Norbornene butanol (90 mmol), Pd-1206 (0.009 mmol), and DANFABA (N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate) (0.027 mmol) were weighed under a nitrogen atmosphere and stirred at 60 °C for 1 hour to obtain a solution. Next, the obtained solution was spin-coated onto easy-adhesive PET (A4360), heated at 60 °C for 7 hours, and then vacuum dried at 80 °C overnight to obtain a precursor polymer film (Step (A)). Next, the obtained precursor polymer film was immersed in ethanol together with the easy-adhesive PET at room temperature for 10 hours. At this time, the residual monomer amount of the precursor polymer film was measured by quantifying the norbornene butanol contained in the washing liquid when the precursor polymer film was washed with ethanol under the following conditions using a GC measuring device (manufactured by Shimadzu Corporation, GC-2030AF). As a result, when the total amount of the used norbornene butanol was set to 100 mol%, it was less than 1%. Next, the obtained precursor polymer film was immersed in 1,3-propanesultone together with the easy-adhesive PET and then reacted at 110 °C for 5 hours to obtain a polymer solid electrolyte membrane (Step (B)). Next, the obtained polymer solid electrolyte membrane was peeled off from the easy-adhesive PET, immersed in ethanol at room temperature for 10 hours, and then further vacuum dried at 50 °C overnight to obtain a polymer solid electrolyte membrane of Example 1 with a thickness of 60 μm, which contains polymer (a) represented by the following formula and is a self-supporting film. [GC Measurement Conditions] · Carrier gas: N2 · Detector: Flame ionization detector (FID), FID temperature: 300 °C · Column: SH-RXi-1HT (manufactured by Shimadzu GL Sciences Inc., inner diameter 0.25, length 30 m, film thickness 0.25 μm) · Vaporization chamber temperature: 210 °C · Column flow rate: 0.64 mL / min • Column heating conditions: Hold at 50°C for 5 minutes, heat at 20°C / min up to 300°C, hold at 300°C for 10 minutes.

[0118] [ka] (In the equation, g + h = 100, and n is an integer greater than or equal to 1.)

[0119] (Example 2) Norbornenebutanol (90 mmol), Pd-1206 (0.009 mmol), and DANFABA (N,N-dimethylanilinium tetrakis(pentafluorophenyl) borate) (0.027 mmol) were weighed under a nitrogen atmosphere and stirred at 60°C for 1 hour to obtain a solution. Next, the obtained solution was spin-coated onto a silicon wafer, heated at 60°C for 7 hours, and then vacuum-dried overnight at 80°C to obtain a precursor polymer film (Step (A)). Next, the obtained precursor polymer film was peeled off the silicon wafer. At this time, the amount of norbornenebutanol contained in the washing solution obtained when the precursor polymer film was washed with ethanol was quantified using a GC measuring instrument (Shimadzu Corporation, GC-2030AF) under the same conditions as in Example 1, and the amount of residual monomer in the precursor polymer film was measured to be 10 mol%, when the total amount of norbornenebutanol used was taken as 100 mol%. Next, the obtained precursor polymer film was immersed in 1,3-propanesaltone and reacted at 110°C for 5 hours to obtain a polymer solid electrolyte membrane (step (B)). Then, the obtained polymer solid electrolyte membrane was immersed in ethanol at room temperature for 10 hours, and then vacuum-dried overnight at 50°C to obtain the polymer solid electrolyte membrane of Example 2, which contains polymer (a) and is a self-supporting membrane with a thickness of 60 μm.

[0120] (Comparative Example 1) A Nafion solution-cast film (Chemours, NR211, 25 μm thick) was used as the polymer solid electrolyte membrane in Comparative Example 1.

[0121] (Comparative Example 2) Norbornenebutanol (120 mmol), Pd-1206 (0.120 mmol), DANFABA (0.120 mmol), and 1-butanol (218 mmol) were weighed under a nitrogen atmosphere and stirred at room temperature for 7 days to obtain a solution. The obtained solution was then reprecipitated with acetone to obtain a polymer powder. The obtained polymer powder was then dissolved in 1-butanol to form a polymer solution, which was spin-coated onto a silicon wafer and dried on a hot plate at 80°C for 5 hours to obtain a precursor polymer film. Next, 1,3-propanesalton was dropped onto the obtained precursor polymer film and reacted at 120°C for 5 hours to obtain a polymer solid electrolyte film (step (B)). Next, the silicon wafer to which the polymer solid electrolyte film was attached was immersed in 80°C hot water to peel off the polymer solid electrolyte film. However, a polymer solid electrolyte film as a self-supporting film could not be obtained.

[0122] <IRスペクトル> The IR spectra of the polymer solid electrolyte membranes of Examples 1 and 2 were measured using a Fourier transform infrared spectrophotometer (Thermo Fisher, Nicolet Summit). Subsequently, from the obtained IR spectra, the 1300 cm⁻¹ spectrum was measured. -1 More than 1400cm -1 Maximum peak intensity I within the following range SO , 2800cm -1 More than 3000cm -1 Maximum peak intensity I within the following range CH and I SO / I CH The value of was calculated. The results are shown in Table 1.

[0123] <Mechanical strength> The polymer solid electrolyte membranes of Examples 1-2 and Comparative Example 1 were cut to 10 mm x 60 mm, wrapped around a rod with a diameter of 1.33 mm and a curvature of 1.5, and their mechanical strength was evaluated based on the following evaluation criteria. The results are shown in Table 1. A: The polymer solid electrolyte membrane did not rupture. B: The polymer solid electrolyte membrane ruptured.

[0124] <Proton conductivity σ> For Examples 1 and 2 and Comparative Example 1, polymer solid electrolyte membranes were clamped in a dedicated jig (Scribner BT-110 membrane conductivity clamp), placed in a constant temperature and humidity chamber, and measured using an electrochemical analyzer (BioLogic SP150e) under the conditions of a measurement frequency of 1 to 500 kHz, a temperature of 30°C, and a humidity of 90% RH. The resistance value was then measured, and the proton conductivity σ (mS / cm) was calculated. The results are shown in Table 1.

[0125] <Amount of curvature> For Examples 1 and 2 and Comparative Example 1, a polymer solid electrolyte membrane was cut into a 4cm x 4cm square to prepare test specimens. The test specimens were then placed on a flat plate and left undisturbed for 5 minutes. Next, the distance from each of the four vertices of the test specimen to the flat plate was measured, and the average value was defined as the amount of warping (mm). The results are shown in Table 1. Furthermore, the polymer solid electrolyte membrane in Example 1 had a large degree of curl, making it impossible to measure the amount of warpage. The amount of warpage is an indicator used to evaluate the flexibility of polymer solid electrolyte membranes; the smaller the amount of warpage, the higher the flexibility.

[0126] [Table 1] [Explanation of Symbols]

[0127] 1 Separator 2・2a・2b Catalyst layer 3 Polymer solid electrolyte membrane 4 Membrane-electrode assembly (MEA) 10 single cells 11 Gas diffusion layer

Claims

1. The polymer contains a constituent unit (P) represented by the following formula (1), A self-supporting polymer solid electrolyte membrane. 【Chemistry 1】 (In formula (1) above, p is 0, 1 or 2, R １ ~R ４ Each independently represents a linear or branched organic group having 1 to 70 carbon atoms, a linear or branched alkyl group having 1 to 70 carbon atoms, a hydrogen atom, a sulfo group, a hydroxyl group, or a halogen atom, each containing one or more selected from the group consisting of a sulfo group, a hydroxyl group, and an ether bond. In formula (1), R １ ~R ４ At least one of these represents a sulfo group, or a linear or branched organic group having 1 to 70 carbon atoms that contains a sulfo group.

2. In the above formula (1), R １ ~R ４ The polymer solid electrolyte membrane according to claim 1, wherein at least one of the members comprises an organic group represented by the following formula (2). 【Chemistry 2】 (In formula (2) above, X represents a linear or branched alkylene group having 1 to 20 carbon atoms, Y represents a linear or branched alkylene group having 1 to 20 carbon atoms, and n represents an integer of 1 or more.)

3. A polymer solid electrolyte membrane comprising a polymer containing the constituent unit (Q) shown in the following formula (3), In the IR spectrum measured using a Fourier transform infrared spectrophotometer for the polymer solid electrolyte membrane, the maximum peak intensity in the range of 1300 cm －１ or more and 1400 cm －１ or less is I ＳＯ , and the maximum peak intensity in the range of 2800 cm －１ or more and 3000 cm －１ or less is I ＣＨ . When the value of I ＳＯ / I ＣＨ is 0.05 or more, A self-supporting polymer solid electrolyte membrane. 【Transformation 3】 (In the above formula (3), q is 0, 1 or 2, R ５ ~R ８ Each of these independently represents a linear or branched organic group having 1 to 70 carbon atoms, a linear or branched alkyl group having 1 to 20 carbon atoms, a hydrogen atom, a sulfo group, a hydroxyl group, or a halogen atom, all containing one or more selected from the group consisting of a sulfo group, a hydroxyl group, and an ether bond.

4. The polymer comprises a precursor polymer containing the constituent unit (T) shown in the following formula (4) and a polymer which is a reaction product of a cyclic sulfonic acid ester. A self-supporting polymer solid electrolyte membrane. 【Chemistry 4】 (In the above formula (4), t is 0, 1 or 2, R ９ ~R １２ Each independently represents a linear or branched organic group having 1 to 10 carbon atoms containing at least one of a hydroxyl group and an ether bond, a linear or branched alkyl group having 1 to 10 carbon atoms, a hydrogen atom, a hydroxyl group, or a halogen atom, in formula (4), R ９ ~R １２ At least one of these represents a hydroxyl group, or a linear or branched hydroxyalkyl group having 1 to 10 carbon atoms.

5. The polymer solid electrolyte membrane according to claim 4, wherein the cyclic sulfonic acid ester has a structure represented by the following formula (5). 【Transformation 5】 (In formula (5) above, Z represents a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms.)

6. The polymer solid electrolyte membrane according to any one of claims 1 to 3, wherein the polymer further comprises a constituent unit (U) represented by the following formula (6). 【Transformation 6】 (In formula (6) above, u is 0, 1 or 2, R １３ ~R １６ Each independently represents a linear or branched organic group having 1 to 10 carbon atoms containing at least one of a hydroxyl group and an ether bond, a linear or branched alkyl group having 1 to 10 carbon atoms, a hydrogen atom, a hydroxyl group, or a halogen atom, in formula (6), R １３ ~R １６ At least one of these represents a hydroxyl group, or a linear or branched hydroxyalkyl group having 1 to 10 carbon atoms.

7. The polymer solid electrolyte membrane according to claim 4 or 5, further comprising a reaction product of the precursor polymer, the cyclic sulfonic acid ester, and a monomer represented by the following formula (7). 【Transformation 7】 (In the above formula (7), v is 0, 1 or 2, R １７ ~R ２０ Each independently represents a linear or branched organic group having 1 to 10 carbon atoms containing at least one of a hydroxyl group and an ether bond, a linear or branched alkyl group having 1 to 10 carbon atoms, a hydrogen atom, a hydroxyl group, or a halogen atom, in formula (7), R １７ ~R ２０ At least one of these represents a hydroxyl group, or a linear or branched hydroxyalkyl group having 1 to 10 carbon atoms.

8. The polymer solid electrolyte membrane according to any one of claims 1 to 5, wherein the content of perfluoroalkyl group constituent units in the polymer is 5.0 mol% or less when the total content of all constituent units in the polymer is 100.0 mol%.

9. The polymer solid electrolyte membrane according to any one of claims 1 to 5, wherein the fluorine content in the polymer solid electrolyte membrane is 5.0% by mass or less when the total amount of the polymer solid electrolyte membrane is 100.0% by mass.

10. The polymer solid electrolyte membrane according to any one of claims 1 to 5, wherein the polymer solid electrolyte membrane is cut to 10 mm x 60 mm and does not break when wrapped around a rod with a diameter of 1.33 mm and a curvature of 1.

5.

11. A polymer solid electrolyte membrane according to any one of claims 1 to 5, wherein the proton conductivity σ at a relative humidity of 90% and a temperature of 30°C, as measured by the method 1 below, is 5 mS / cm or more. (Method 1) The polymer solid electrolyte membrane is clamped in a jig and placed in a constant temperature and humidity chamber. An electrochemical measuring instrument is used to measure the resistance value under the conditions of a measurement frequency of 1 to 500 kHz, a temperature of 30°C, and a humidity of 90% RH, and the proton conductivity σ (mS / cm) is calculated.

12. A polymer solid electrolyte membrane according to any one of claims 1 to 5, wherein the amount of warpage measured by the method 2 below is 5.0 mm or less. (Method 2) The polymer solid electrolyte membrane is cut into a 4 cm x 4 cm square to prepare a test specimen. Then, the test specimen is placed on a flat plate and left to stand for 5 minutes. Next, the distance from each of the four vertices of the test piece to the flat plate is measured, and the average value of these measurements is taken as the amount of warping (mm).

13. A polymer solid electrolyte membrane according to any one of claims 1 to 5, wherein the thickness is 1 μm or more and 100 μm or less.

14. A polymer solid electrolyte membrane according to any one of claims 1 to 5, which can be used in a fuel cell.

15. A polymer solid electrolyte membrane roll comprising a core having an outer surface, and a polymer solid electrolyte membrane according to any one of claims 1 to 5 wound around the outer surface multiple times.

16. The polymer solid electrolyte membrane roll according to claim 15, wherein the polymer solid electrolyte membrane is wound around the outer surface multiple times, with a release film provided on at least one side.

17. A fuel cell comprising a polymer solid electrolyte membrane according to any one of claims 1 to 5.

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