Laminate

Abstract

The present invention relates to a laminate. A laminate comprising an electrode for electrolysis and a diaphragm or a power supply body in contact with the electrode for electrolysis, wherein the force applied by the electrode for electrolysis per unit mass / unit area to the diaphragm or the power supply body is less than 1.5 N / mg·cm 2 .

Description

[0001] This application is a divisional application. The international application number of the original application is PCT / JP2018 / 011535, the international application date is March 22, 2018, the Chinese national application number is 201880015823.8, the date of entry into China is September 4, 2019, and the name of the invention is "Electrode for electrolysis, laminate, wound body, electrolytic cell, method for manufacturing electrolytic cell, method for updating electrode, method for updating laminate, and method for manufacturing wound body". Technical Field

[0002] The present invention relates to an electrode for electrolysis, a laminate, a wound body, an electrolytic cell, a method for manufacturing an electrolytic cell, a method for renewing an electrode, a method for renewing a laminate, and a method for manufacturing a wound body. Background Art

[0003] The electrolysis of aqueous alkali metal chloride solutions such as saline solution and the electrolysis of water (hereinafter referred to as "electrolysis") utilizes an electrolytic cell equipped with a diaphragm, more specifically, an ion exchange membrane or a microporous membrane. In most cases, the electrolytic cell comprises a large number of electrolytic cells connected in series. Electrolysis is performed with a diaphragm interposed between the electrolytic cells. Within the electrolytic cells, a cathode chamber having a cathode and an anode chamber having an anode are arranged back-to-back, separated by a partition wall (back plate) or by pressing using pressure, bolt fastening, or the like.

[0004] Currently, the anodes and cathodes used in these electrolytic cells are fixed to the anode chambers and cathode chambers of the electrolytic cells by welding, clamping, etc., and then stored and transported to the customer. On the other hand, the diaphragm is stored and transported to the customer in a state where it is wound alone on a tube made of vinyl chloride (polyvinyl chloride). At the customer's site, the electrolytic cells are arranged on the frame of the electrolytic cell, and the diaphragm is clamped between the electrolytic cells to assemble the electrolytic cell. The manufacture of the electrolytic cells and the assembly of the electrolytic cell at the customer's site are carried out in this way. As a structure that can be applied to such an electrolytic cell, a structure in which a diaphragm and an electrode are integrated is disclosed in Patent Documents 1 and 2.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 58-048686

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 55-148775 Summary of the Invention

[0009] Problems to be solved by the invention

[0010] If electrolysis is started and continued, due to various reasons, each component will deteriorate and the electrolysis performance will decrease, and each component will need to be replaced at a certain time. The diaphragm can be simply updated by extracting it from the electrolysis unit and inserting a new diaphragm. On the other hand, the anode and cathode are fixed to the electrolysis unit, so when the electrode is updated, the electrolysis unit must be taken out of the electrolytic cell, transported to a dedicated update factory, and fixed by welding or the like. After the old electrode is peeled off, a new electrode is set, and then fixed by welding or other methods, transported to the electrolysis factory, and returned to the electrolysis cell. This is a problem that produces very complicated operations. Here, it is considered to use a structure formed by integrating the diaphragm and electrode described in Patent Documents 1 and 2 by thermal compression for the above-mentioned update, but although the structure can be manufactured relatively easily at the laboratory level, it is not easy to manufacture according to the actual commercial size of the electrolysis unit (for example, 1.5m high and 3m wide). In addition, due to the significantly poor electrolytic performance (electrolysis voltage, current efficiency, salt concentration in caustic soda, etc.) and durability, and the generation of chlorine and hydrogen on the diaphragm and interface electrodes, if used for electrolysis for a long time, it will completely peel off and cannot be used in practice.

[0011] The present invention has been made in view of the problems existing in the above-mentioned prior art, and its purpose is to provide the following electrolytic electrodes, laminates, wound bodies, electrolytic cells, methods for manufacturing electrolytic cells, methods for renewing electrodes, methods for renewing laminates, and methods for manufacturing wound bodies.

[0012] (Purpose 1)

[0013] One of the objects of the present invention is to provide an electrolytic electrode, a laminate, and a wound body that are easy to transport and handle, can greatly simplify the operation when starting up a new electrolytic cell or when replacing a deteriorated electrode, and can also maintain or improve the electrolytic performance.

[0014] (Second Purpose)

[0015] One of the objects of the present invention is to provide a laminate that can improve the work efficiency when replacing electrodes in an electrolytic cell and can exhibit excellent electrolytic performance even after replacement.

[0016] (Purpose 3)

[0017] One of the objects of the present invention is to provide a laminate that can improve the work efficiency when replacing electrodes in an electrolytic cell, and further exhibit excellent electrolytic performance even after replacement, from a different aspect from the second object.

[0018] (Purpose 4)

[0019] One of the objects of the present invention is to provide an electrolytic cell, a method for producing the electrolytic cell, and a method for renewing a laminated body that have excellent electrolytic performance and can prevent damage to the diaphragm.

[0020] (Purpose 5)

[0021] One object of the present invention is to provide a method for manufacturing an electrolytic cell, a method for replacing an electrode, and a method for manufacturing a wound body, which can improve the work efficiency when replacing electrodes in the electrolytic cell.

[0022] (Purpose 6)

[0023] One of the objects of the present invention is to provide a method for manufacturing an electrolytic cell that can improve the work efficiency when replacing electrodes in the electrolytic cell from a different aspect from the fifth object.

[0024] (Purpose 7)

[0025] One of the objects of the present invention is to provide a method for manufacturing an electrolytic cell that can improve the work efficiency when replacing electrodes in the electrolytic cell from a different aspect from the fifth and sixth objects mentioned above.

[0026] Means for solving problems

[0027] The present inventors conducted extensive research to achieve the first objective and discovered that by producing electrolysis electrodes with a low mass per unit area that can be bonded to diaphragms such as ion exchange membranes and microporous membranes, or to deteriorated electrodes with relatively weak force, transportation and handling can be facilitated, significantly simplifying the operation of starting up new electrolytic cells or replacing deteriorated components, and thereby significantly improving electrolytic performance compared to conventional electrolytic cells. Furthermore, the inventors discovered that electrolytic performance can be equal to or improved over that of conventional electrolytic cells, which require complex replacement procedures. This led to the completion of the present invention.

[0028] That is, the present invention includes the following aspects.

[0029] [1] An electrode for electrolysis, wherein the mass per unit area of ​​the electrode for electrolysis is 48 mg / cm 2 Below, the force applied per unit mass and unit area is 0.08N / mg·cm 2 above.

[0030] [2] The electrode for electrolysis according to [1], wherein the electrode for electrolysis comprises an electrode substrate for electrolysis and a catalyst layer, and the thickness of the electrode substrate for electrolysis is 300 μm or less.

[0031] [3] The electrode for electrolysis according to [1] or [2], wherein the ratio measured by the following method (3) is 75% or more.

[0032] [Method (3)]

[0033] Inorganic particles and a binder were applied to both surfaces of a membrane containing a perfluorocarbon polymer having ion exchange groups. The resulting membrane (170 mm square) and an electrolytic electrode sample (130 mm square) were sequentially laminated. The laminate was placed on the curved surface of a polyethylene tube (outer diameter 145 mm) at a temperature of 23±2°C and a relative humidity of 30±5%, with the electrolytic electrode sample facing outward. The laminate and tube were thoroughly immersed in pure water, and excess water adhering to the laminate surface and tube was removed. After one minute, the area ratio (%) of the portion of the membrane containing the inorganic particles and a binder applied to both surfaces of the membrane containing the ion exchange groups and the electrolytic electrode sample in close contact with the membrane was measured.

[0034] [4] The electrode for electrolysis according to any one of [1] to [3], wherein the electrode for electrolysis has a porous structure with an open porosity of 5 to 90%.

[0035] [5] The electrode for electrolysis according to any one of [1] to [4], wherein the electrode for electrolysis has a porous structure with an open porosity of 10 to 80%.

[0036] [6] The electrode for electrolysis according to any one of [1] to [5], wherein the thickness of the electrode for electrolysis is 315 μm or less.

[0037] [7] The electrode for electrolysis according to any one of [1] to [6], wherein the value of the electrode for electrolysis measured by the following method (A) is 40 mm or less.

[0038] [Method (A)]

[0039] Under the conditions of a temperature of 23±2°C and a relative humidity of 30±5%, a sample consisting of a laminated ion exchange membrane and the above-mentioned electrolysis electrode was wound and fixed onto the curved surface of a vinyl chloride core material having an outer diameter of Φ32 mm. After standing for 6 hours, the electrolysis electrode was separated and placed on a horizontal plate. The vertical heights L1 and L2 of the two ends of the electrolysis electrode were measured, and their average value was used as the measured value.

[0040] [8] The electrode for electrolysis as described in any one of [1] to [7], wherein the size of the electrode for electrolysis is 50 mm × 50 mm, and the electrode is subjected to the conditions of temperature 24°C, relative humidity 32%, piston speed 0.2 cm / s and ventilation volume 0.4 cc / cm 2 / s, the ventilation resistance is 24 kPa·s / m or less.

[0041] [9] The electrode for electrolysis according to any one of [1] to [8], wherein the substrate of the electrode for electrolysis contains at least one element selected from nickel (Ni) and titanium (Ti).

[0042]

[10] A laminate comprising the electrode for electrolysis according to any one of [1] to [9].

[0043]

[11] A wound body comprising the electrode for electrolysis according to any one of [1] to [9], or the laminate according to

[10] .

[0044] The inventors have conducted repeated and in-depth research to achieve the second purpose, and found that the following laminated body makes transportation and handling easier, which can greatly simplify the operation when starting a new electrolytic cell or replacing deteriorated parts, and further maintain or improve the electrolytic performance. The above-mentioned laminated body has electrodes that are bonded to power conductors such as ion exchange membranes and microporous membranes or deteriorated original electrodes with relatively weak force, thereby completing the present invention.

[0045] That is, the present invention includes the following aspects.

[0046] [2-1]

[0047] A laminate comprising:

[0048] Electrodes for electrolysis; and

[0049] a diaphragm or power supply in contact with the above-mentioned electrolysis electrode,

[0050] The force applied per unit mass and per unit area of ​​the electrolysis electrode to the separator or power supply is less than 1.5 N / mg·cm 2 .

[0051] [2-2]

[0052] The laminate according to [2-1], wherein the force applied per unit mass and per unit area of ​​the electrolysis electrode to the separator or the power supply exceeds 0.005 N / mg·cm 2 .

[0053] [2-3]

[0054] The laminate according to [2-1] or [2-2], wherein the power supply is a metal mesh, a metal nonwoven fabric, a punched metal, a metal expansion mesh, or a foamed metal.

[0055] [2-4]

[0056] The laminate according to any one of [2-1] to [2-3], wherein the separator has, as at least one surface layer, a layer comprising a mixture of hydrophilic oxide particles and a polymer into which an ion exchange group is introduced.

[0057] [2-5]

[0058] The laminate according to any one of [2-1] to [2-4], wherein a liquid is interposed between the electrolysis electrode and the separator or the power supply.

[0059] The present inventors have conducted intensive studies to achieve the third object and have found that the above-mentioned problems can be solved by a laminate in which the separator and the electrolysis electrodes are partially fixed, thereby completing the present invention.

[0060] That is, the present invention includes the following aspects.

[0061] [3-1]

[0062] A laminate comprising:

[0063] diaphragm; and

[0064] an electrolysis electrode fixed to at least one region of the surface of the separator,

[0065] The ratio of the region on the surface of the separator is greater than 0% and less than 93%.

[0066] [3-2]

[0067] The laminate as described in [3-1], wherein the above-mentioned electrode for electrolysis contains at least one catalyst component selected from the group consisting of Ru, Rh, Pd, Ir, Pt, Au, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ag, Ta, W, Re, Os, Al, In, Sn, Sb, Ga, Ge, B, C, N, O, Si, P, S, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb and Dy.

[0068] [3-3]

[0069] The laminate according to [3-1] or [3-2], wherein in the region, at least a portion of the electrolysis electrode is fixed through the separator.

[0070] [3-4]

[0071] The laminate according to any one of [3-1] to [3-3], wherein in the region, at least a portion of the electrolysis electrode is located inside the separator and fixed thereto.

[0072] [3-5]

[0073] The laminate according to any one of [3-1] to [3-4] further comprises a fixing member for fixing the separator and the electrolysis electrode.

[0074] [3-6]

[0075] In the laminate according to [3-5], at least a portion of the fixing member grips the diaphragm and the electrolysis electrode from the outside.

[0076] [3-7]

[0077] In the laminate according to [3-5] or [3-6], at least a portion of the fixing member fixes the diaphragm and the electrolysis electrode using a magnetic force.

[0078] [3-8]

[0079] The laminate according to any one of [3-1] to [3-7], wherein the separator comprises an ion exchange membrane having a surface layer containing an organic resin.

[0080] The above-mentioned organic resin exists in the above-mentioned region.

[0081] [3-9]

[0082] The laminate according to any one of [3-1] to [3-8], wherein the separator includes a first ion exchange resin layer and a second ion exchange resin layer having an EW different from that of the first ion exchange resin layer.

[0083] [3-10]

[0084] The laminate according to any one of [3-1] to [3-8], wherein the separator includes a first ion exchange resin layer and a second ion exchange resin layer having a functional group different from that of the first ion exchange resin layer.

[0085] The present inventors have conducted intensive studies to achieve the fourth object and have found that the above-mentioned problems can be solved by sandwiching at least a portion of a laminate of a separator and an electrolytic electrode between an anode-side gasket and a cathode-side gasket, thereby completing the present invention.

[0086] That is, the present invention includes the following aspects.

[0087] [4-1]

[0088] An electrolytic cell comprising:

[0089] anode;

[0090] an anode frame supporting the anode;

[0091] an anode side gasket disposed on the anode frame;

[0092] a cathode facing the anode;

[0093] a cathode frame supporting the cathode;

[0094] A cathode side gasket disposed on the cathode frame and facing the anode side gasket; and

[0095] A laminate comprising a separator and an electrolysis electrode, arranged between the anode-side gasket and the cathode-side gasket.

[0096] At least a portion of the laminate is sandwiched between the anode-side gasket and the cathode-side gasket.

[0097] The electrolysis electrode was made into a size of 50 mm × 50 mm and the temperature was 24°C, the relative humidity was 32%, the piston speed was 0.2 cm / s and the ventilation volume was 0.4 cc / cm 2 / s, the ventilation resistance is 24 kPa·s / m or less.

[0098] [4-2]

[0099] The electrolytic cell according to [4-1], wherein the thickness of the electrolysis electrode is 315 μm or less.

[0100] [4-3]

[0101] The electrolytic cell according to [4-1] or [4-2], wherein the value of the electrolysis electrode measured by the following method (A) is 40 mm or less.

[0102] [4-Method (A)]

[0103] Under the conditions of a temperature of 23±2°C and a relative humidity of 30±5%, a sample consisting of a laminated ion exchange membrane and the above-mentioned electrolysis electrode was wound and fixed onto the curved surface of a vinyl chloride core material having an outer diameter of Φ32 mm. After standing for 6 hours, the electrolysis electrode was separated and placed on a horizontal plate. The vertical heights L1 and L2 of the two ends of the electrolysis electrode were measured, and their average value was used as the measured value.

[0104] [4-4]

[0105] The electrolytic cell according to any one of [4-1] to [4-3], wherein the mass per unit area of ​​the electrolysis electrode is 48 mg / cm 2 the following.

[0106] [4-5]

[0107] The electrolytic cell according to any one of [4-1] to [4-4], wherein the force applied per unit mass / unit area of ​​the electrolysis electrode exceeds 0.005 N / mg·cm 2 .

[0108] [4-6]

[0109] The electrolytic cell according to any one of [4-1] to [4-5], wherein the outermost peripheral edge of the stack is located outside in the current-carrying surface direction relative to the outermost peripheral edges of the anode-side gasket and the cathode-side gasket.

[0110] [4-7]

[0111] An electrolytic cell as described in any one of [4-1] to [4-6], wherein the above-mentioned electrode for electrolysis contains at least one catalyst component selected from the group consisting of Ru, Rh, Pd, Ir, Pt, Au, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ag, Ta, W, Re, Os, Al, In, Sn, Sb, Ga, Ge, B, C, N, O, Si, P, S, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb and Dy.

[0112] [4-8]

[0113] The electrolytic cell according to any one of [4-1] to [4-7], wherein in the laminate, at least a portion of the electrolysis electrode is fixed through the separator.

[0114] [4-9]

[0115] The electrolytic cell according to any one of [4-1] to [4-7], wherein in the laminate, at least a portion of the electrolysis electrode is located and fixed inside the separator.

[0116] [4-10]

[0117] The electrolytic cell according to any one of [4-1] to [4-9], further comprising a fixing member for fixing the diaphragm and the electrolysis electrode in the laminate.

[0118] [4-11]

[0119] The electrolytic cell according to [4-10], wherein in the laminate, at least a portion of the fixing member passes through the diaphragm and the electrolysis electrode to be fixed.

[0120] [4-12]

[0121] In the electrolytic cell according to [4-10] or [4-11], in the laminate, the fixing member includes a soluble material soluble in the electrolyte.

[0122] [4-13]

[0123] The electrolytic cell according to any one of [4-10] to [4-12], wherein in the laminate, at least a portion of the fixing member grips the diaphragm and the electrolysis electrode from the outside.

[0124] [4-14]

[0125] The electrolytic cell according to any one of [4-10] to [4-13], wherein in the laminate, at least a portion of the fixing member fixes the diaphragm and the electrolysis electrode using a magnetic force.

[0126] [4-15]

[0127] The electrolytic cell according to any one of [4-1] to [4-14], wherein the diaphragm comprises an ion exchange membrane having a surface layer containing an organic resin,

[0128] The electrolysis electrode is fixed to the organic resin.

[0129] [4-16]

[0130] The electrolytic cell according to any one of [4-1] to [4-15], wherein the separator includes a first ion exchange resin layer and a second ion exchange resin layer having an EW different from that of the first ion exchange resin layer.

[0131] [4-17]

[0132] A method for manufacturing an electrolytic cell, which is the method for manufacturing an electrolytic cell according to any one of [4-1] to [4-16], wherein:

[0133] This manufacturing method includes the step of sandwiching the laminate between the anode-side gasket and the cathode-side gasket.

[0134] [4-18]

[0135] A method for renewing a laminate, which is the method for renewing a laminate in an electrolytic cell according to any one of [4-1] to [4-16], wherein:

[0136] The updating method has the following steps:

[0137] a step of separating the laminate from the anode-side gasket and the cathode-side gasket to remove the laminate from the electrolytic cell; and

[0138] A step of sandwiching the new laminate between the anode-side gasket and the cathode-side gasket.

[0139] The present inventors have conducted intensive studies to achieve the fifth object and have found that the above-mentioned problems can be solved by using an electrolysis electrode or a wound body of a laminate of the electrolysis electrode and a novel separator, thereby completing the present invention.

[0140] That is, the present invention includes the following aspects.

[0141] [5-1]

[0142] A method for manufacturing an electrolytic cell, wherein an electrolytic electrode or a laminate of the electrolytic electrode and a new diaphragm is arranged in an existing electrolytic cell, wherein the existing electrolytic cell comprises an anode, a cathode facing the anode, and a diaphragm arranged between the anode and the cathode, wherein:

[0143] The method for producing the electrolytic cell uses the electrolysis electrode or the wound body of the laminate.

[0144] [5-2]

[0145] The method for producing an electrolytic cell according to [5-1] further comprises the step (A) of obtaining the wound body by holding the electrolysis electrode or the laminate in a wound state.

[0146] [5-3]

[0147] The method for producing an electrolytic cell according to [5-1] or [5-2], further comprising the step (B) of releasing the wound state of the wound body.

[0148] [5-4]

[0149] The method for producing an electrolytic cell as described in [5-3] further comprises, after the step (B), the step (C) of disposing the electrolysis electrode or the laminate on at least one surface of the anode and the cathode.

[0150] [5-5]

[0151] A method for updating an electrode is a method for updating an existing electrode by using an electrode for electrolysis, wherein:

[0152] The above-mentioned renewal method uses the wound body of the above-mentioned electrolysis electrode.

[0153] [5-6]

[0154] The electrode renewal method according to [5-5] further comprises the step (A') of obtaining the wound body by keeping the electrolysis electrode in a wound state.

[0155] [5-7]

[0156] The electrode renewal method according to [5-5] or [5-6], further comprising a step (B') of unwinding the electrolysis electrode.

[0157] [5-8]

[0158] The electrode renewal method described in [5-7] further comprises, after the step (B'), the step (C') of disposing the electrolysis electrode on the surface of the existing electrode.

[0159] [5-9]

[0160] A method for manufacturing a wound body for updating an existing electrolytic cell, wherein the existing electrolytic cell comprises an anode, a cathode facing the anode, and a separator disposed between the anode and the cathode, wherein:

[0161] The method for producing the wound body includes the step of winding an electrode for electrolysis or a laminate of the electrode for electrolysis and a new separator to obtain the wound body.

[0162] The present inventors have conducted intensive studies to achieve the sixth object and have found that the above-mentioned problems can be solved by integrating an electrolytic electrode and a novel separator at a temperature at which the separator does not melt, thereby completing the present invention.

[0163] That is, the present invention includes the following aspects.

[0164] [6-1]

[0165] A method for manufacturing an electrolytic cell, wherein a laminate is disposed in an existing electrolytic cell to manufacture a new electrolytic cell, wherein the existing electrolytic cell comprises an anode, a cathode facing the anode, and a separator disposed between the anode and the cathode, wherein:

[0166] The method for manufacturing the electrolytic cell comprises the following steps:

[0167] Step (A), integrating the electrolysis electrode and a new separator at a temperature at which the separator does not melt, thereby obtaining the laminate; and

[0168] Step (B) is to replace the diaphragm in the existing electrolytic cell with the laminate after the step (A).

[0169] [6-2]

[0170] The method for manufacturing an electrolytic cell as described in [6-1], wherein the above-mentioned integration is performed under normal pressure.

[0171] The present inventors have conducted repeated and intensive studies to achieve the seventh object, and as a result, have found that the above-mentioned problems can be solved by operating within the electrolytic cell frame, thereby completing the present invention.

[0172] That is, the present invention includes the following aspects.

[0173] [7-1]

[0174] A method for manufacturing an electrolytic cell, wherein a laminate comprising an electrolytic electrode and a new diaphragm is arranged in an existing electrolytic cell, wherein the existing electrolytic cell comprises an anode, a cathode facing the anode, a diaphragm fixed between the anode and the cathode, and an electrolytic cell frame supporting the anode, the cathode, and the diaphragm.

[0175] The method for manufacturing the electrolytic cell comprises the following steps:

[0176] Step (A), releasing the diaphragm from the electrolytic cell frame; and

[0177] Step (B): After the step (A), the separator is replaced with the laminate.

[0178] [7-2]

[0179] The method for producing an electrolytic cell according to [7-1], wherein the step (A) is performed by sliding the anode and the cathode in their respective arrangement directions.

[0180] [7-3]

[0181] The method for manufacturing an electrolytic cell as described in [7-1] or [7-2], wherein after the step (B), the laminate is fixed within the electrolytic cell frame by pressing from the anode and the cathode.

[0182] [7-4]

[0183] The method for manufacturing an electrolytic cell as described in any one of [7-1] to [7-3], wherein in the above step (B), the laminate is fixed to at least one surface of the above anode and the above cathode at a temperature at which the above laminate does not melt.

[0184] [7-5]

[0185] A method for manufacturing an electrolytic cell, wherein the method is used to manufacture a new electrolytic cell by arranging an electrolysis electrode in an existing electrolytic cell, wherein the existing electrolytic cell comprises an anode, a cathode facing the anode, a diaphragm fixed between the anode and the cathode, and an electrolytic cell frame supporting the anode, the cathode, and the diaphragm, wherein:

[0186] The method for manufacturing the electrolytic cell comprises the following steps:

[0187] Step (A), releasing the diaphragm from the electrolytic cell frame; and

[0188] Step (B') is a step of placing the electrolysis electrode between the diaphragm and the anode or cathode after the step (A).

[0189] Effects of the Invention

[0190] (1) The electrolysis electrode of the present invention can be easily transported and handled, which greatly simplifies the operation when starting a new electrolytic cell or replacing a deteriorated electrode, and furthermore, maintains or improves the electrolysis performance.

[0191] (2) According to the laminate of the present invention, the work efficiency during electrode renewal in the electrolytic cell can be improved, and excellent electrolytic performance can be exhibited even after renewal.

[0192] (3) According to the laminate of the present invention, the work efficiency during electrode renewal in the electrolytic cell can be improved from a different aspect from (2) above, and excellent electrolytic performance can be exhibited even after renewal.

[0193] (4) The electrolytic cell of the present invention can prevent damage to the diaphragm while providing excellent electrolytic performance.

[0194] (5) According to the method for manufacturing an electrolytic cell of the present invention, it is possible to improve the work efficiency when replacing electrodes in the electrolytic cell.

[0195] (6) According to the method for manufacturing an electrolytic cell of the present invention, it is possible to improve the work efficiency when replacing electrodes in the electrolytic cell from a different aspect from the above-mentioned (5).

[0196] (7) According to the method for manufacturing an electrolytic cell of the present invention, it is possible to improve the work efficiency when the electrodes in the electrolytic cell are updated from a different aspect from the above-mentioned (5) and (6). BRIEF DESCRIPTION OF THE DRAWINGS

[0197] Figure 1 This is a schematic cross-sectional view of an electrode for electrolysis according to one embodiment of the present invention.

[0198] Figure 2 It is a schematic cross-sectional view showing one embodiment of an ion exchange membrane.

[0199] Figure 3 This is a schematic diagram for explaining the aperture ratio of the reinforcing core material constituting the ion exchange membrane.

[0200] Figure 4This is a schematic diagram for explaining a method of forming continuous pores in an ion exchange membrane.

[0201] Figure 5 is a schematic cross-sectional view of an electrolysis cell.

[0202] Figure 6 is a schematic cross-sectional view showing a state where two electrolytic cells are connected in series.

[0203] Figure 7 is a schematic diagram of an electrolytic cell.

[0204] Figure 8 It is a schematic perspective view showing the process of assembling the electrolytic cell.

[0205] Figure 9 This is a schematic cross-sectional view of a reverse current absorber included in an electrolytic cell.

[0206] Figure 10 This is a schematic diagram of the evaluation method of the force applied per unit mass and unit area (1) described in the Examples.

[0207] Figure 11 This is a schematic diagram of the 280 mm diameter cylindrical winding evaluation method (1) described in the Examples.

[0208] Figure 12 This is a schematic diagram of the 280 mm diameter cylindrical winding evaluation method (2) described in the Examples.

[0209] Figure 13 This is a schematic diagram of the 145 mm diameter cylindrical winding evaluation method (3) described in the Examples.

[0210] Figure 14 This is a schematic diagram of the elastic deformation test of the electrode described in the Examples.

[0211] Figure 15 This is a schematic diagram of the evaluation method of softness after plastic deformation.

[0212] Figure 16 This is a schematic diagram of the electrode produced in Comparative Example 13.

[0213] Figure 17 This is a schematic diagram of a structure used to place the electrode produced in Comparative Example 13 on a nickel mesh current feeder.

[0214] Figure 18 This is a schematic diagram of the electrode produced in Comparative Example 14.

[0215] Figure 19 This is a schematic diagram of a structure used to place the electrode produced in Comparative Example 14 on a nickel mesh current feeder.

[0216] Figure 20 This is a schematic diagram of the electrode produced in Comparative Example 15.

[0217] Figure 21 This is a schematic diagram of a structure used to place the electrode produced in Comparative Example 15 on a nickel mesh current feeder.

[0218] Figure 22 This is a schematic cross-sectional view of an electrode for electrolysis in one embodiment of the present invention.

[0219] Figure 23 It is a schematic cross-sectional view showing one embodiment of an ion exchange membrane.

[0220] Figure 24 This is a schematic diagram for explaining the aperture ratio of the reinforcing core material constituting the ion exchange membrane.

[0221] Figure 25 This is a schematic diagram for explaining a method of forming continuous pores in an ion exchange membrane.

[0222] Figure 26 is a schematic cross-sectional view of an electrolysis cell.

[0223] Figure 27 is a schematic cross-sectional view showing a state where two electrolytic cells are connected in series.

[0224] Figure 28 is a schematic diagram of an electrolytic cell.

[0225] Figure 29 It is a schematic perspective view showing the process of assembling the electrolytic cell.

[0226] Figure 30 This is a schematic cross-sectional view of a reverse current absorber included in an electrolytic cell.

[0227] Figure 31 This is a schematic diagram of the evaluation method of the force applied per unit mass and unit area (1) described in the Examples.

[0228] Figure 32 This is a schematic diagram of the 280 mm diameter cylindrical winding evaluation method (1) described in the Examples.

[0229] Figure 33 This is a schematic diagram of the 280 mm diameter cylindrical winding evaluation method (2) described in the Examples.

[0230] Figure 34 This is a schematic diagram of the 145 mm diameter cylindrical winding evaluation method (3) described in the Examples.

[0231] Figure 35 This is a schematic diagram of the elastic deformation test of the electrode described in the Examples.

[0232] Figure 36 This is a schematic diagram of the evaluation method of softness after plastic deformation.

[0233] Figure 37 This is a schematic diagram of the electrode produced in Example 34.

[0234] Figure 38 This is a schematic diagram of the structure used to place the electrode produced in Example 34 on the nickel mesh current conductor.

[0235] Figure 39 This is a schematic diagram of the electrode produced in Example 35.

[0236] Figure 40 This is a schematic diagram of the structure used to place the electrode produced in Example 35 on the nickel mesh current conductor.

[0237] Figure 41 This is a schematic diagram of the electrode produced in Example 36.

[0238] Figure 42 This is a schematic diagram of the structure used to place the electrode produced in Example 36 on the nickel mesh current conductor.

[0239] Figure 43 This is a schematic cross-sectional view of an electrode for electrolysis in one embodiment of the present invention.

[0240] Figure 44 is a schematic cross-sectional view illustrating one embodiment of an ion exchange membrane.

[0241] Figure 45 This is a schematic diagram for explaining the aperture ratio of the reinforcing core material constituting the ion exchange membrane.

[0242] Figure 46 This is a schematic diagram for explaining a method of forming continuous pores in an ion exchange membrane.

[0243] Figure 47 middle, Figure 47 A is a schematic cross-sectional view of a laminate illustrating a mode in which at least a portion of an electrode for electrolysis is fixed through a separator. Figure 47 B is shown for obtaining Figure 47 A diagram illustrating the process of the structure of A.

[0244] Figure 48 middle, Figure 48 A is a schematic cross-sectional view of a laminate illustrating a mode in which at least a portion of an electrode for electrolysis is located inside a separator and fixed thereto. Figure 48 B is shown for obtaining Figure 48 A diagram illustrating the process of the structure of A.

[0245] Figure 49 middle, Figure 49 A to C are schematic cross-sectional views of a laminated body illustrating an embodiment in which a filament-shaped fixing member is used as a fixing member for fixing the separator and the electrolysis electrode.

[0246] Figure 50 This is a schematic cross-sectional view of a laminated body illustrating an embodiment in which an organic resin is used as a fixing member for fixing the separator and the electrolytic electrode.

[0247] Figure 51 middle, Figure 51 A is a schematic cross-sectional view of a laminated body illustrating a mode in which at least a portion of a fixing member grips and fixes the separator and the electrolysis electrode from the outside. Figure 51 B is a schematic cross-sectional view of a laminated body illustrating a mode in which at least a portion of a fixing member fixes the separator and the electrolysis electrode using a magnetic force.

[0248] Figure 52 is a schematic cross-sectional view of an electrolysis cell.

[0249] Figure 53 is a schematic cross-sectional view showing a state where two electrolytic cells are connected in series.

[0250] Figure 54 is a schematic diagram of an electrolytic cell.

[0251] Figure 55 It is a schematic perspective view showing the process of assembling the electrolytic cell.

[0252] Figure 56 This is a schematic cross-sectional view of a reverse current sink that may be included in an electrolytic cell.

[0253] Figure 57 This is an explanatory diagram showing the laminate in Example 1.

[0254] Figure 58 This is an explanatory diagram showing a laminate in Example 2.

[0255] Figure 59 This is an explanatory diagram showing a laminate in Example 3.

[0256] Figure 60 This is an explanatory diagram showing a laminate in Example 4.

[0257] Figure 61 This is an explanatory diagram showing a laminate in Example 5.

[0258] Figure 62 This is an explanatory diagram showing a laminate in Example 6.

[0259] Figure 63is a schematic cross-sectional view of an electrolysis cell.

[0260] Figure 64 middle, Figure 64 A is a schematic cross-sectional view showing a state in which two electrolytic units in a conventional electrolytic tank are connected in series. Figure 64 B is a schematic cross-sectional view showing a state in which two electrolytic units in the electrolytic cell of the present embodiment are connected in series.

[0261] Figure 65 is a schematic diagram of an electrolytic cell.

[0262] Figure 66 It is a schematic perspective view showing the process of assembling the electrolytic cell.

[0263] Figure 67 This is a schematic cross-sectional view of a reverse current sink that may be included in an electrolytic cell.

[0264] Figure 68 This is a schematic cross-sectional view of an electrode for electrolysis in one embodiment of the present invention.

[0265] Figure 69 is a schematic cross-sectional view illustrating one embodiment of an ion exchange membrane.

[0266] Figure 70 This is a schematic diagram for explaining the aperture ratio of the reinforcing core material constituting the ion exchange membrane.

[0267] Figure 71 This is a schematic diagram for explaining a method of forming continuous pores in an ion exchange membrane.

[0268] Figure 72 This is an explanatory diagram for explaining the positional relationship between the laminate and the gasket.

[0269] Figure 73 This is an explanatory diagram for explaining the positional relationship between the laminate and the gasket.

[0270] Figure 74 middle, Figure 74 A is a schematic cross-sectional view of a laminate illustrating a mode in which at least a portion of an electrode for electrolysis is fixed through a separator. Figure 74 B is shown for obtaining Figure 74 A diagram illustrating the process of the structure of A.

[0271] Figure 75 middle, Figure 75 A is a schematic cross-sectional view of a laminate illustrating a mode in which at least a portion of an electrode for electrolysis is located inside a separator and fixed thereto. Figure 75 B is shown for obtaining Figure 75 A diagram illustrating the process of the structure of A.

[0272] Figure 76 middle, Figure 76 A to C are schematic cross-sectional views of a laminated body illustrating an embodiment in which a filament-shaped fixing member is used as a fixing member for fixing the separator and the electrolysis electrode.

[0273] Figure 77 This is a schematic cross-sectional view of a laminated body illustrating an embodiment in which an organic resin is used as a fixing member for fixing the separator and the electrolytic electrode.

[0274] Figure 78 middle, Figure 78 A is a schematic cross-sectional view of a laminated body illustrating a mode in which at least a portion of a fixing member grips and fixes the separator and the electrolysis electrode from the outside. Figure 78 B is a schematic cross-sectional view of a laminated body illustrating a mode in which at least a portion of a fixing member fixes the separator and the electrolysis electrode using a magnetic force.

[0275] Figure 79 This is a schematic diagram of the evaluation method of the force applied per unit mass and unit area (1) described in the Examples.

[0276] Figure 80 This is a schematic diagram of the 280 mm diameter cylindrical winding evaluation method (1) described in the Examples.

[0277] Figure 81 This is a schematic diagram of the 280 mm diameter cylindrical winding evaluation method (2) described in the Examples.

[0278] Figure 82 This is a schematic diagram of the 145 mm diameter cylindrical winding evaluation method (3) described in the Examples.

[0279] Figure 83 This is a schematic diagram of the evaluation of the flexibility of the electrode described in the Examples.

[0280] Figure 84 This is a schematic diagram of the evaluation method of softness after plastic deformation.

[0281] Figure 85 This is a schematic diagram of the electrode produced in Example 35.

[0282] Figure 86 This is a schematic diagram of the structure used to place the electrode produced in Example 35 on the nickel mesh current conductor.

[0283] Figure 87 This is a schematic diagram of the electrode produced in Example 36.

[0284] Figure 88 This is a schematic diagram of the structure used to place the electrode produced in Example 36 on the nickel mesh current conductor.

[0285] Figure 89 This is a schematic diagram of the electrode produced in Example 37.

[0286] Figure 90 This is a schematic diagram of the structure used to place the electrode produced in Example 37 on the nickel mesh current conductor.

[0287] Figure 91 is a schematic cross-sectional view of an electrolysis cell.

[0288] Figure 92 is a schematic cross-sectional view showing a state where two electrolytic cells are connected in series.

[0289] Figure 93 is a schematic diagram of an electrolytic cell.

[0290] Figure 94 It is a schematic perspective view showing the process of assembling the electrolytic cell.

[0291] Figure 95 This is a schematic cross-sectional view of a reverse current sink that may be included in an electrolytic cell.

[0292] Figure 96 This is a schematic cross-sectional view of an electrode for electrolysis in one embodiment of the present invention.

[0293] Figure 97 is a schematic cross-sectional view illustrating one embodiment of an ion exchange membrane.

[0294] Figure 98 This is a schematic diagram for explaining the aperture ratio of the reinforcing core material constituting the ion exchange membrane.

[0295] Figure 99 This is a schematic diagram for explaining a method of forming continuous pores in an ion exchange membrane.

[0296] Figure 100 This is a schematic diagram of the laminate produced in Example 1.

[0297] Figure 101 This is a schematic diagram of a case where the laminate produced in Example 1 is wound to form a wound body.

[0298] Figure 102 This is a schematic diagram of the laminate produced in Example 4.

[0299] Figure 103 is a schematic cross-sectional view of an electrolysis cell.

[0300] Figure 104 is a schematic cross-sectional view showing a state where two electrolytic cells are connected in series.

[0301] Figure 105is a schematic diagram of an electrolytic cell.

[0302] Figure 106 It is a schematic perspective view showing the process of assembling the electrolytic cell.

[0303] Figure 107 This is a schematic cross-sectional view of a reverse current sink that may be included in an electrolytic cell.

[0304] Figure 108 This is a schematic cross-sectional view of an electrode for electrolysis in one embodiment of the present invention.

[0305] Figure 109 is a schematic cross-sectional view illustrating one embodiment of an ion exchange membrane.

[0306] Figure 110 This is a schematic diagram for explaining the aperture ratio of the reinforcing core material constituting the ion exchange membrane.

[0307] Figure 111 This is a schematic diagram for explaining a method of forming continuous pores in an ion exchange membrane.

[0308] Figure 112 is a schematic cross-sectional view of an electrolysis cell.

[0309] Figure 113 is a schematic cross-sectional view showing a state where two electrolytic cells are connected in series.

[0310] Figure 114 is a schematic diagram of an electrolytic cell.

[0311] Figure 115 It is a schematic perspective view showing the process of assembling the electrolytic cell.

[0312] Figure 116 This is a schematic cross-sectional view of a reverse current sink that may be included in an electrolytic cell.

[0313] Figure 117 middle, Figure 117 (A) is a schematic diagram of an electrolytic cell for explaining an example of each step of the first aspect of the present embodiment. Figure 117 (B) is Figure 117 (A) Corresponding schematic stereogram.

[0314] Figure 118 middle, Figure 118 (A) is a schematic diagram of an electrolytic cell for explaining an example of each step of the second aspect of the present embodiment. Figure 118 (B) is Figure 118 (A) Corresponding schematic stereogram.

[0315] Figure 119 This is a schematic cross-sectional view of an electrode for electrolysis in one embodiment of the present invention.

[0316] Figure 120 is a schematic cross-sectional view illustrating one embodiment of an ion exchange membrane.

[0317] Figure 121 This is a schematic diagram for explaining the aperture ratio of the reinforcing core material constituting the ion exchange membrane.

[0318] Figure 122 This is a schematic diagram for explaining a method of forming continuous pores in an ion exchange membrane. DETAILED DESCRIPTION

[0319] Hereinafter, the embodiments of the present invention (hereinafter also referred to as the present embodiment) will be described in detail with reference to the accompanying drawings as needed according to <First Embodiment> to <Seventh Embodiment>. The following embodiments are examples for illustrating the present invention, and the present invention is not limited to the following contents. In addition, the drawings show an example of an embodiment, but the embodiment is not limited to this and is not interpreted. The present invention can be implemented with appropriate modifications within the scope of its main points. It should be noted that the positional relationships such as up, down, left, and right in the drawings are based on the positional relationships shown in the drawings unless otherwise stated. The dimensions and proportions of the drawings are not limited to the dimensions and proportions shown.

[0320] <First embodiment>

[0321] Here, refer to Figures 1 to 21 , the first embodiment of the present invention is described in detail.

[0322] [Electrolysis Electrode]

[0323] Regarding the electrolysis electrode of the first embodiment (hereinafter referred to as "the present embodiment"), the mass per unit area is 48 mg / cm2 from the perspectives of good handling, good adhesion to separators such as ion exchange membranes and microporous membranes, deteriorated electrodes, and non-catalyst-coated power supplies, as well as economic efficiency. 2 From the above aspects, it is preferably 30 mg / cm 2 Below, more preferably 20 mg / cm 2 From the perspective of handling, adhesion and economic efficiency, 15 mg / cm 2 The lower limit is not particularly limited, but is, for example, 1 mg / cm 2 about.

[0324] The mass per unit area can be adjusted to the above range by, for example, appropriately adjusting the aperture ratio, electrode thickness, etc., as described later. More specifically, for example, if the thickness is the same, increasing the aperture ratio tends to reduce the mass per unit area, while decreasing the aperture ratio tends to increase the mass per unit area.

[0325] The electrolysis electrode of this embodiment has a force of 0.08 N / (mg·cm2) per unit mass and per unit area in order to achieve good handling properties and good adhesion to separators such as ion exchange membranes and microporous membranes, deteriorated electrodes, and power supply bodies that are not coated with catalysts. 2 ) or more. In addition, from the above aspects, it is preferably 0.1N / (mg·cm 2 ) or more, more preferably 0.14N / (mg·cm 2 ) or more, and from the perspective of easier handling in large-scale (for example, 1.5 m × 2.5 m) sizes, 0.2 N / (mg·cm 2 The upper limit is not particularly limited, but is preferably 1.6 N / (mg·cm 2 ) or less, more preferably less than 1.6N / (mg·cm 2 ), more preferably less than 1.5N / (mg·cm 2 ), and more preferably 1.2 N / mg·cm 2 Below, more preferably 1.20 N / mg·cm 2 Below. More preferably, it is 1.1N / mg·cm 2 Below, more preferably 1.10 N / mg·cm 2 Below, particularly preferably 1.0 N / mg·cm 2 Below, particularly preferably 1.00 N / mg·cm 2 the following.

[0326] When the electrolysis electrode of this embodiment has a wide elastic deformation range, the thickness of the electrolysis electrode is preferably 315 μm or less, more preferably 220 μm or less, even more preferably 170 μm or less, even more preferably 150 μm or less, particularly preferably 145 μm or less, even more preferably 140 μm or less, even more preferably 138 μm or less, and even more preferably 135 μm or less, from the perspective of achieving better handling properties and better adhesion to separators such as ion exchange membranes or microporous membranes, degraded electrodes, and non-catalyst-coated power supplies. A thickness of 135 μm or less provides good handling properties. Furthermore, from the same perspective as above, the thickness is preferably 130 μm or less, more preferably less than 130 μm, even more preferably 115 μm or less, and even more preferably 65 μm or less. The lower limit is not particularly limited, but is preferably 1 μm or greater. From a practical perspective, it is more preferably 5 μm or greater, and even more preferably 20 μm or greater. It should be noted that, in this embodiment, the term "wide elastic deformation region" refers to the fact that, after the electrolysis electrode is wound into a wound body, warping due to the winding is less likely to occur after the body is unwound. Furthermore, the thickness of the electrolysis electrode, when including the catalyst layer described below, refers to the combined thickness of the electrolysis electrode substrate and the catalyst layer.

[0327] According to the electrode for electrolysis of the present embodiment, as described above, it has good adhesion to diaphragms such as ion exchange membranes or microporous membranes, degraded electrodes, and power supplies that are not coated with catalysts, and can be used in an integrated manner with diaphragms such as ion exchange membranes or microporous membranes. Therefore, when updating the electrode, the electrode can be updated using the same simple operation as that for updating the diaphragm without complicated replacement operations such as peeling off the electrode fixed to the electrolysis unit, thereby greatly improving operating efficiency. In addition, even in the case where a new electrolysis unit is only provided with a power supply (i.e., an electrode without a catalyst layer is provided), it can function as an electrode simply by pasting the electrode for electrolysis of the present embodiment onto the power supply, so that the catalyst coating can also be significantly reduced or completely eliminated.

[0328] Furthermore, according to the electrode for electrolysis of this embodiment, the electrolysis performance can be made equal to or further improved than that of a new product.

[0329] The electrolysis electrode of the present embodiment can be stored in a state of being wound around a polyvinyl chloride tube or the like (in a roll or the like) and transported to a customer, etc., and thus can be handled very easily.

[0330] The applied force can be measured by the following method (i) or (ii), and the details are as described in the Examples. Regarding the applied force, the value obtained by the measurement of method (i) (also referred to as "applied force (1)") and the value obtained by the measurement of method (ii) (also referred to as "applied force (2)") may be the same or different, but both values ​​are 0.08 N / (mg·cm 2 )above.

[0331] The applied force can be brought into the above range by, for example, appropriately adjusting the aperture ratio, electrode thickness, arithmetic mean surface roughness, etc., which will be described later. More specifically, for example, increasing the aperture ratio tends to reduce the applied force, while decreasing the aperture ratio tends to increase the applied force.

[0332] [Method (i)]

[0333] A nickel plate (1.2 mm thick, 200 mm square) obtained by sandblasting alumina with particle number 320, an ion exchange membrane (170 mm square, details of the ion exchange membrane mentioned here are as described in the examples) coated with inorganic particles and a binder on both sides of a membrane having an ion exchange group, and an electrolysis electrode sample (130 mm square) were stacked in sequence. After the stack was fully immersed in pure water, excess water attached to the surface of the stack was removed to obtain a sample for measurement. It should be noted that the arithmetic mean surface roughness (Ra) of the nickel plate after sandblasting was 0.7 μm. The specific calculation method of the arithmetic mean surface roughness (Ra) is as described in the examples.

[0334] Under the conditions of a temperature of 23±2°C and a relative humidity of 30±5%, use a tension-compression testing machine to vertically elevate only the electrolysis electrode sample among the test samples at a rate of 10 mm / minute. The load applied when the electrolysis electrode sample is vertically elevated by 10 mm is measured. This measurement is repeated three times, and the average value is calculated.

[0335] The average value was divided by the area of ​​the overlapping portion of the electrolysis electrode sample and the ion exchange membrane and the mass of the electrolysis electrode sample in the portion overlapping the ion exchange membrane to calculate the force applied per unit mass and unit area (1) (N / mg·cm 2 ).

[0336] The force (1) applied per unit mass and unit area obtained by method (i) is 0.08 N / (mg·cm ) from the viewpoint of obtaining good handling properties and good adhesion to separators such as ion exchange membranes or microporous membranes, deteriorated electrodes, and power supply bodies not coated with catalysts. 2) or more, preferably 0.1N / (mg·cm 2 ) or more, and from the perspective of easier handling in large-scale (for example, 1.5 m × 2.5 m) conditions, 0.2 N / (mg·cm 2 The upper limit is not particularly limited, but is preferably 1.6 N / (mg·cm 2 ) or less, more preferably less than 1.6N / (mg·cm 2 ), more preferably less than 1.5N / (mg·cm 2 ), and more preferably 1.2 N / mg·cm 2 Below, more preferably 1.20 N / mg·cm 2 Below. More preferably, it is 1.1N / mg·cm 2 Below, more preferably 1.10 N / mg·cm 2 Below, particularly preferably 1.0 N / mg·cm 2 Below, particularly preferably 1.00 N / mg·cm 2 the following.

[0337] If the electrolysis electrode of this embodiment satisfies the applied force (1), it can be used in an integrated manner with a diaphragm such as an ion exchange membrane or a microporous membrane. Therefore, when the electrode is replaced, it is not necessary to replace the cathode and anode fixed to the electrolysis unit by welding or other methods, thereby significantly improving work efficiency. In addition, by using the electrolysis electrode of this embodiment as an integrated electrode with an ion exchange membrane, the electrolysis performance can be made equal to or further improved compared to the performance of the new product.

[0338] When shipping a new electrolysis unit, conventional electrodes attached to the electrolysis unit are catalytically coated. However, simply combining the uncatalytically coated electrodes with the electrolysis electrodes of this embodiment allows them to be used as electrodes. This significantly reduces or eliminates the manufacturing process and amount of catalyst required for catalytic coating. Conventional electrodes with significantly reduced or no catalytic coating can be electrically connected to the electrolysis electrodes of this embodiment, functioning as current supply sources.

[0339] [Method (ii)]

[0340] A nickel plate (1.2 mm thick, 200 mm square, the same nickel plate as in method (i) above) sandblasted with alumina with grain number 320 and an electrolytic electrode sample (130 mm square) were stacked in sequence. The stack was thoroughly immersed in pure water, and excess water adhering to the surface of the stack was removed to obtain a measurement sample. Using a tensile-compression tester, only the electrolytic electrode sample was vertically elevated at a rate of 10 mm / minute under conditions of 23±2°C and 30±5% relative humidity. The load applied when the electrolytic electrode sample was elevated 10 mm in the vertical direction was measured. This measurement was repeated three times, and the average value was calculated.

[0341] The average value was divided by the area of ​​the overlapping portion of the electrolytic electrode sample and the nickel plate and the mass of the electrolytic electrode sample in the overlapping portion with the nickel plate to calculate the adhesive force per unit mass per unit area (2) (N / mg·cm 2 ).

[0342] Regarding the force (2) applied per unit mass and unit area obtained by method (ii), the force (2) applied was 0.08 N / (mg·cm ) from the viewpoint of obtaining good handling properties and good adhesion to separators such as ion exchange membranes or microporous membranes, deteriorated electrodes, and power supply bodies not coated with catalysts. 2 ) or more, preferably 0.1N / (mg·cm 2 ) or more, and from the perspective of easier handling in large-scale (for example, 1.5 m × 2.5 m) conditions, 0.14 N / (mg·cm 2 The upper limit is not particularly limited, but is preferably 1.6 N / (mg·cm 2 ) or less, more preferably less than 1.6N / (mg·cm 2 ), more preferably less than 1.5N / (mg·cm 2 ), and more preferably 1.2 N / mg·cm 2 Below, more preferably 1.20 N / mg·cm 2 Below. More preferably, it is 1.1N / mg·cm 2 Below, more preferably 1.10 N / mg·cm 2 Below, particularly preferably 1.0 N / mg·cm 2 Below, particularly preferably 1.00 N / mg·cm 2 the following.

[0343] If the electrolysis electrode of this embodiment satisfies the applied force (2), it can be stored in a state (e.g., in a roll) wound around a polyvinyl chloride tube, for example, and transported to a customer, thereby greatly facilitating handling. Furthermore, by attaching the electrolysis electrode of this embodiment to a deteriorated electrode, the electrolysis performance can be made equal to or even improved from that of a new electrode.

[0344] In the present embodiment, the liquid present between the diaphragm such as ion exchange membrane or microporous membrane and the electrode for electrolysis or the current supply body (degraded electrode or the electrode not coated with catalyst) and the electrode for electrolysis can be any liquid as long as it is a substance that generates surface tension such as water, an organic solvent. The larger the surface tension of the liquid, the larger the force applied between the diaphragm and the electrode for electrolysis or the metal plate and the electrode for electrolysis, so the liquid with a large surface tension is preferred. As liquid, the following substances (the numerical value in the brackets is the surface tension of the liquid) can be cited.

[0345] Hexane (20.44 mN / m), acetone (23.30 mN / m), methanol (24.00 mN / m), ethanol (24.05 mN / m), ethylene glycol (50.21 mN / m), water (72.76 mN / m)

[0346] If the liquid has a high surface tension, the diaphragm and the electrolysis electrode, or the porous metal plate or metal plate (electrical source) and the electrolysis electrode, are integrated (forming a laminate), making electrode replacement easier. The amount of liquid between the diaphragm and the electrolysis electrode, or the porous metal plate or metal plate (electrical source) and the electrolysis electrode, is small enough to allow adhesion due to surface tension. Consequently, even if the liquid mixes with the electrolyte after being installed in the electrolysis cell of the laminate, it will not affect the electrolysis itself.

[0347] From a practical aspect, as liquid, it is preferred to use a liquid with a surface tension of 20mN / m to 80mN / m, such as ethanol, ethylene glycol, water. Particularly preferred water or dissolving caustic soda, potassium hydroxide, lithium hydroxide, sodium bicarbonate, saleratus, sodium carbonate, potassium carbonate etc. in water to become an alkaline aqueous solution. In addition, these liquids can also be made to include a surfactant and regulate the surface tension. By including a surfactant, the adhesion of the diaphragm and the electrolysis electrode or the metal plate and the electrolysis electrode changes, and processability can be adjusted. As a surfactant, there is no particular restriction, and any one of an ionic surfactant or a nonionic surfactant can be used.

[0348] The electrolysis electrode of the present embodiment preferably includes an electrolysis electrode substrate and a catalyst layer. The thickness (gauge thickness) of the electrolysis electrode substrate is not particularly limited. From the perspective of obtaining good handling properties, having good adhesion to diaphragms such as ion exchange membranes or microporous membranes, degraded electrodes, and power supply bodies that are not catalyst-coated, being able to be appropriately rolled into a roll, being well bent, and being easy to handle under large sizes (for example, sizes of 1.5m×2.5m), it is preferably 300μm or less, more preferably 205μm or less, further preferably 155μm or less, further more preferably 135μm or less, further preferably 125μm or less, further preferably 120μm or less, further preferably 100μm or less, and from the perspective of handling properties and economy, it is further preferably 50μm or less. The lower limit is not particularly limited, for example, 1μm, preferably 5μm, and more preferably 15μm.

[0349] The electrolysis electrode of this embodiment is not particularly limited. However, from the perspective of achieving good handling properties and good adhesion to separators such as ion exchange membranes or microporous membranes, deteriorated electrodes, and power supply bodies that are not coated with catalysts, the ratio measured by the following method (2) is preferably 90% or more, more preferably 92% or more. Furthermore, from the perspective of facilitating handling of large-scale electrodes (e.g., 1.5 m × 2.5 m), it is even more preferably 95% or more. The upper limit is 100%.

[0350] [Method (2)]

[0351] An ion exchange membrane (170 mm square) and an electrolytic electrode sample (130 mm square) were stacked in this order. The stack was placed on the curved surface of a polyethylene tube (280 mm outer diameter) at a temperature of 23±2°C and a relative humidity of 30±5%, with the electrolytic electrode sample facing outward. The stack and tube were thoroughly immersed in pure water, and excess water adhering to the stack surface and tube was removed. After one minute, the area ratio (%) of the portion where the ion exchange membrane (170 mm square) and the electrolytic electrode sample were in close contact was measured.

[0352] The electrode for electrolysis of this embodiment is not particularly limited. However, from the perspectives of achieving good handling properties, good adhesion to separators such as ion exchange membranes or microporous membranes, deteriorated electrodes, and power supply bodies not coated with catalysts, and being able to be appropriately rolled up and bent well, the ratio measured by the following method (3) is preferably 75% or more, more preferably 80% or more. Furthermore, from the perspective of facilitating handling of large-scale electrodes (e.g., 1.5 m × 2.5 m), it is even more preferably 90% or more. The upper limit is 100%.

[0353] [Method (3)]

[0354] An ion exchange membrane (170 mm square) and an electrolytic electrode sample (130 mm square) were stacked in this order. The stack was placed on the curved surface of a polyethylene tube (145 mm outer diameter) at a temperature of 23±2°C and a relative humidity of 30±5%, with the electrolytic electrode sample facing outward. The stack and tube were thoroughly immersed in pure water, and excess water adhering to the stack surface and tube was removed. After one minute, the area ratio (%) of the portion where the ion exchange membrane (170 mm square) and the electrolytic electrode sample were in close contact was measured.

[0355] The electrolysis electrode of this embodiment is not particularly limited. However, from the perspectives of achieving good handling, maintaining good adhesion to separators such as ion exchange membranes or microporous membranes, deteriorated electrodes, and non-catalyst-coated power supplies, and preventing the accumulation of gases generated during electrolysis, it is preferably a porous structure with an open porosity or void ratio of 5 to 90%. The open porosity is more preferably 10 to 80%, and even more preferably 20 to 75%.

[0356] It should be noted that the porosity refers to the ratio of open areas per unit volume. The number of open areas can be calculated in various ways, depending on whether the consideration is down to the submicron level or only visible openings. In this embodiment, the volume V is calculated from the gauge thickness, width, and length of the electrode, and the weight W is then measured to calculate the porosity A using the following formula.

[0357] A=(1-(W / (V×ρ))×100

[0358] ρ is the density of the electrode material (g / cm 3 For example, in the case of nickel, it is 8.908 g / cm 3 , in the case of titanium it is 4.506 g / cm 3 The porosity can be appropriately adjusted by the following methods: if punching metal is used, the area of ​​the metal punched per unit area is changed; if metal mesh is used, the values ​​of SW (short diameter), LW (long diameter), and feed are changed; if it is a mesh, the wire diameter and mesh count of the metal fiber are changed; if electroforming is used, the pattern of the photoresist used is changed; if it is a non-woven fabric, the metal fiber diameter and fiber density are changed; if it is a foamed metal, the mold used to form the gap is changed; and so on.

[0359] Regarding the electrolysis electrode in this embodiment, from the perspective of handling, the value measured by the following method (A) is preferably 40 mm or less, more preferably 29 mm or less, further preferably 10 mm or less, and even more preferably 6.5 mm or less. The specific measurement method is as described in the Examples.

[0360] [Method (A)]

[0361] Under the conditions of a temperature of 23±2°C and a relative humidity of 30±5%, a sample consisting of a laminated ion exchange membrane and the above-mentioned electrolysis electrode was wound and fixed onto the curved surface of a vinyl chloride core material having an outer diameter of Φ32 mm. After standing for 6 hours, the electrolysis electrode was separated and placed on a horizontal plate. The vertical heights L1 and L2 of the two ends of the electrolysis electrode were measured, and their average value was used as the measured value.

[0362] The electrolysis electrode in this embodiment has a size of 50 mm × 50 mm and is subjected to a temperature of 24° C., a relative humidity of 32%, a piston speed of 0.2 cm / s, and an air flow rate of 0.4 cc / cm 2 / s (hereinafter also referred to as "measurement condition 1"), the ventilation resistance (hereinafter also referred to as "ventilation resistance 1") is preferably 24 kPa·s / m or less. A large ventilation resistance means that air is difficult to flow, which refers to a state of high density. In this state, the products produced by electrolysis remain in the electrodes, and the reaction matrix is ​​difficult to diffuse into the interior of the electrodes, so there is a tendency for the electrolysis performance (voltage, etc.) to deteriorate. In addition, there is a tendency for the concentration on the membrane surface to increase. Specifically, there is a tendency for the caustic concentration to increase on the cathode side and the supply of brine to decrease on the anode side. As a result, the product stays at a high concentration at the interface where the diaphragm contacts the electrode, and there is a tendency to cause damage to the diaphragm, and also cause a voltage increase and membrane damage on the cathode side, and damage to the membrane on the anode side. In this embodiment, in order to prevent these adverse conditions, it is preferred that the ventilation resistance is 24 kPa·s / m or less. From the same aspects as above, it is more preferred to be less than 0.19 kPa·s / m, further preferably less than 0.15 kPa·s / m, and further preferably less than 0.07 kPa·s / m.

[0363] It should be noted that in the present embodiment, if the ventilation resistance is greater than a certain value, in the case of the cathode, the NaOH produced at the electrode stays at the interface between the electrode and the diaphragm, and tends to become a high concentration; in the case of the anode, the supply of brine is reduced, and the brine concentration tends to become a low concentration. From the perspective of preventing possible damage to the diaphragm caused by such retention, it is preferably less than 0.19 kPa·s / m, more preferably below 0.15 kPa·s / m, and even more preferably below 0.07 kPa·s / m.

[0364] On the other hand, when the air resistance is low, the electrode area is reduced, resulting in a reduced electrolysis area and a tendency for electrolysis performance (voltage, etc.) to deteriorate. When the air resistance is zero, since no electrolysis electrodes are provided, the power supply functions as an electrode, and there is a tendency for electrolysis performance (voltage, etc.) to deteriorate significantly. From this perspective, the preferred lower limit value of the air resistance 1 is not particularly limited, but is preferably greater than 0 kPa·s / m, more preferably 0.0001 kPa·s / m or greater, and even more preferably 0.001 kPa·s / m or greater.

[0365] It should be noted that regarding the ventilation resistance 1, from the perspective of its measurement method, sufficient measurement accuracy may not be obtained when it is 0.07 kPa·s / m or less. From this perspective, for an electrolysis electrode with a ventilation resistance 1 of 0.07 kPa·s / m or less, the ventilation resistance (hereinafter also referred to as "ventilation resistance 2") can also be evaluated using the following measurement method (hereinafter also referred to as "measurement condition 2"). That is, the ventilation resistance 2 is measured when the electrolysis electrode has a size of 50 mm × 50 mm, a temperature of 24°C, a relative humidity of 32%, a piston speed of 2 cm / s, and a ventilation volume of 4 cc / cm 2 / s ventilation resistance.

[0366] The specific method for measuring ventilation resistance 1 and 2 is as described in the Examples.

[0367] The ventilation resistances 1 and 2 can be adjusted to the above ranges by, for example, appropriately adjusting the porosity, electrode thickness, etc., as described later. More specifically, for example, when the thickness is constant, increasing the porosity tends to decrease the ventilation resistances 1 and 2, while decreasing the porosity tends to increase the ventilation resistances 1 and 2.

[0368] Hereinafter, one form of the electrode for electrolysis according to the present embodiment will be described.

[0369] The electrolysis electrode of this embodiment preferably includes an electrolysis electrode substrate and a catalyst layer. The catalyst layer may be composed of multiple layers or a single layer structure as described below.

[0370] like Figure 1 As shown, the electrolysis electrode 100 of this embodiment includes an electrolysis electrode substrate 10 and a pair of first layers 20 covering both surfaces of the electrolysis electrode substrate 10. The first layer 20 preferably covers the entire electrolysis electrode substrate 10. This facilitates improving the catalytic activity and durability of the electrode. It should be noted that the first layer 20 may be deposited on only one surface of the electrolysis electrode substrate 10.

[0371] In addition, if Figure 1As shown, the surface of the first layer 20 may be covered by the second layer 30. The second layer 30 preferably covers the entire first layer 20. Alternatively, the second layer 30 may be laminated on only one surface of the first layer 20.

[0372] (Electrode base material for electrolysis)

[0373] The electrolysis electrode substrate 10 is not particularly limited; for example, nickel, nickel alloys, stainless steel, and valve metals such as titanium can be used. Preferably, the electrolysis electrode substrate contains at least one element selected from nickel (Ni) and titanium (Ti). Specifically, the electrolysis electrode substrate preferably contains at least one element selected from nickel (Ni) and titanium (Ti).

[0374] When stainless steel is used in a high-concentration alkaline aqueous solution, a substrate composed of nickel (Ni) is preferably used as the electrolysis electrode substrate, considering the elution of iron and chromium and the fact that the conductivity of stainless steel is about 1 / 10 of that of nickel.

[0375] Furthermore, when the electrolysis electrode substrate 10 is used in a nearly saturated, high-concentration saline solution or in a chlorine gas generating atmosphere, the material is preferably titanium having high corrosion resistance.

[0376] The shape of the electrolysis electrode substrate 10 is not particularly limited, and an appropriate shape can be selected according to the purpose. As the shape, any one of punching metal, non-woven fabric, foamed metal, expanded metal, a metal porous foil formed by electroforming, a so-called woven mesh made by weaving metal wires, etc. can be used. Among them, punching metal or expanded metal is preferred. It should be noted that electroforming refers to a technology for making a metal film of a precise pattern by combining photoengraving and electroplating. It is a method of forming a pattern on a substrate using a photoresist and electroplating the portion not protected by the resist to obtain a metal film.

[0377] The shape of the electrolytic electrode substrate has appropriate specifications depending on the distance between the anode and cathode in the electrolytic cell. While not particularly limited, expanded metal or perforated metal can be used when the distance between the anode and cathode is limited. In the case of a so-called zero-gap electrolytic cell where the ion exchange membrane and the electrodes are in contact, woven mesh made of fine wires, foamed metal, non-woven metal fabric, expanded metal, perforated metal, or porous metal foil can be used.

[0378] Examples of the electrolysis electrode substrate 10 include metal foil, metal mesh, metal nonwoven fabric, punched metal, expanded metal, and foamed metal.

[0379] As the sheet material before being processed into punched metal or expanded metal, preferably a rolled sheet material, electrolytic foil, etc. As a post-treatment, the electrolytic foil is preferably further plated with the same element as the base material to form irregularities on the surface.

[0380] As described above, the thickness of the electrolysis electrode substrate 10 is preferably 300 μm or less, more preferably 205 μm or less, even more preferably 155 μm or less, still more preferably 135 μm or less, even more preferably 125 μm or less, even more preferably 120 μm or less, and even more preferably 100 μm or less. From the perspective of handling and economic efficiency, it is even more preferably 50 μm or less. The lower limit is not particularly limited, but is, for example, 1 μm, preferably 5 μm, and more preferably 15 μm.

[0381] In the electrolysis electrode substrate, it is preferred to anneal the substrate in an oxidizing atmosphere to alleviate residual stress during processing. Furthermore, to improve adhesion to the catalyst layer coated on the surface, the surface of the electrolysis electrode substrate is preferably formed with irregularities using a steel grid, an alumina grid, or the like, and then acid-treated to increase the surface area. Plating with the same element as the substrate is preferred to increase the surface area.

[0382] In order to ensure close contact between the first layer 20 and the surface of the electrolysis electrode substrate 10, the electrolysis electrode substrate 10 is preferably subjected to a treatment to increase its surface area. Examples of treatments to increase the surface area include sandblasting using cut wire, steel grid, alumina grid, etc.; acid treatment using sulfuric acid or hydrochloric acid; and plating using the same element as the substrate. The arithmetic mean surface roughness (Ra) of the substrate surface is not particularly limited, but is preferably 0.05 μm to 50 μm, more preferably 0.1 to 10 μm, and even more preferably 0.1 to 5 μm.

[0383] Next, a description will be given of a case where the electrode for electrolysis of this embodiment is used as an anode for electrolysis of sodium chloride.

[0384] (First floor)

[0385] Figure 1 In the embodiment of the present invention, the first layer 20 serving as the catalyst layer comprises at least one oxide selected from the group consisting of ruthenium oxide, iridium oxide, and titanium oxide. Examples of ruthenium oxides include RuO2, IrO2, and TiO2. Preferably, the first layer 20 comprises both ruthenium oxide and titanium oxide, or alternatively, comprises all three oxides, namely, ruthenium oxide, iridium oxide, and titanium oxide. This makes the first layer 20 more stable, further improving its adhesion to the second layer 30.

[0386] When the first layer 20 contains both ruthenium oxide and titanium oxide, the amount of titanium oxide contained in the first layer 20 is preferably 1 to 9 mol, more preferably 1 to 4 mol, per 1 mol of ruthenium oxide contained in the first layer 20. By setting the composition ratio of the two oxides within this range, the electrolytic electrode 100 exhibits excellent durability.

[0387] When the first layer 20 contains three oxides of ruthenium oxide, iridium oxide, and titanium oxide, the amount of iridium oxide contained in the first layer 20 is preferably 0.2 to 3 mol, more preferably 0.3 to 2.5 mol, per 1 mol of ruthenium oxide contained in the first layer 20. Furthermore, the amount of titanium oxide contained in the first layer 20 is preferably 0.3 to 8 mol, more preferably 1 to 7 mol, per 1 mol of ruthenium oxide contained in the first layer 20. By setting the composition ratio of the three oxides within this range, the electrolytic electrode 100 exhibits excellent durability.

[0388] When the first layer 20 contains at least two oxides selected from ruthenium oxide, iridium oxide, and titanium oxide, these oxides preferably form a solid solution. By forming an oxide solid solution, the electrolytic electrode 100 exhibits excellent durability.

[0389] In addition to the above-mentioned composition, any composition may be used as long as it contains at least one oxide of ruthenium oxide, iridium oxide, and titanium oxide. For example, an oxide coating containing ruthenium, iridium, tantalum, niobium, titanium, tin, cobalt, manganese, platinum, etc., known as DSA (registered trademark), may also be used as the first layer 20.

[0390] The first layer 20 does not need to be a single layer and may include multiple layers. For example, the first layer 20 may include a layer containing three oxides and a layer containing two oxides. The thickness of the first layer 20 is preferably 0.05 to 10 μm, more preferably 0.1 to 8 μm.

[0391] (Second floor)

[0392] The second layer 30 preferably contains ruthenium and titanium. This can further reduce the overvoltage of chlorine immediately after electrolysis.

[0393] The second layer 30 preferably contains palladium oxide, a solid solution of palladium oxide and platinum, or an alloy of palladium and platinum. This can further reduce the overvoltage of chlorine immediately after electrolysis.

[0394] When the second layer 30 is thick, the period during which the electrolytic performance can be maintained becomes longer. However, from the viewpoint of economic efficiency, the thickness of the second layer 30 is preferably 0.05 to 3 μm.

[0395] Next, a description will be given of a case where the electrode for electrolysis of this embodiment is used as a cathode for electrolysis of sodium chloride.

[0396] (First floor)

[0397] The components of the first layer 20 serving as the catalyst layer can include metals such as C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and oxides or hydroxides of the metals.

[0398] In the case of containing at least one of a platinum group metal, a platinum group metal oxide, a platinum group metal hydroxide, and an alloy containing a platinum group metal, the platinum group metal, the platinum group metal oxide, the platinum group metal hydroxide, and the alloy containing a platinum group metal preferably contain at least one platinum group metal of platinum, palladium, rhodium, ruthenium, and iridium.

[0399] As the platinum group metal, platinum is preferably contained.

[0400] As the platinum group metal oxide, ruthenium oxide is preferably contained.

[0401] As the platinum group metal hydroxide, ruthenium hydroxide is preferably contained.

[0402] As the platinum group metal alloy, an alloy containing platinum, nickel, iron, or cobalt is preferable.

[0403] Furthermore, if necessary, it is preferable to contain an oxide or hydroxide of a lanthanoid element as the second component. This allows the electrolytic electrode 100 to exhibit excellent durability.

[0404] The oxide or hydroxide of the lanthanoid element preferably contains at least one selected from lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, and dysprosium.

[0405] Furthermore, it is preferred to contain an oxide or hydroxide of a transition metal as a third component as necessary.

[0406] By adding the third component, the electrolysis electrode 100 exhibits more excellent durability and the electrolysis voltage can be reduced.

[0407] Examples of preferred combinations include ruthenium alone, ruthenium + nickel, ruthenium + cerium, ruthenium + lanthanum, ruthenium + lanthanum + platinum, ruthenium + lanthanum + palladium, ruthenium + praseodymium, ruthenium + praseodymium + platinum, ruthenium + praseodymium + platinum + palladium, ruthenium + neodymium, ruthenium + neodymium + platinum, ruthenium + neodymium + manganese, ruthenium + neodymium + iron, ruthenium + neodymium + cobalt, ruthenium + neodymium + zinc, ruthenium + neodymium + gallium, ruthenium + neodymium + sulfur, ruthenium + neodymium + lead, ruthenium + neodymium + nickel, ruthenium + Neodymium + copper, ruthenium + samarium, ruthenium + samarium + manganese, ruthenium + samarium + iron, ruthenium + samarium + cobalt, ruthenium + samarium + zinc, ruthenium + samarium + gallium, ruthenium + samarium + sulfur, ruthenium + samarium + lead, ruthenium + samarium + nickel, platinum + cerium, platinum + palladium + cerium, platinum + palladium + lanthanum + cerium, platinum + iridium, platinum + palladium, platinum + iridium + palladium, platinum + nickel + palladium, platinum + nickel + ruthenium, alloys of platinum and nickel, alloys of platinum and cobalt, alloys of platinum and iron, etc.

[0408] When no platinum group metals, platinum group metal oxides, platinum group metal hydroxides or alloys containing platinum group metals are contained, the main component of the catalyst is preferably nickel.

[0409] Preferably, it contains at least one of nickel metal, oxide, and hydroxide.

[0410] A transition metal may be added as a second component. The second component preferably contains at least one element selected from titanium, tin, molybdenum, cobalt, manganese, iron, sulfur, zinc, copper, and carbon.

[0411] Preferred combinations include nickel + tin, nickel + titanium, nickel + molybdenum, and nickel + cobalt.

[0412] If necessary, an intermediate layer may be provided between the first layer 20 and the electrolysis electrode substrate 10. By providing the intermediate layer, the durability of the electrolysis electrode 100 can be improved.

[0413] The intermediate layer is preferably one having an affinity for both the first layer 20 and the electrolytic electrode substrate 10. Preferred intermediate layers include nickel oxide, platinum group metals, platinum group metal oxides, and platinum group metal hydroxides. The intermediate layer can be formed by applying a solution containing components for forming the intermediate layer and then firing it. Alternatively, the substrate can be heat-treated in an air atmosphere at a temperature of 300 to 600°C to form a surface oxide layer. Alternatively, the intermediate layer can be formed using known methods such as thermal spraying and ion plating.

[0414] (Second floor)

[0415] The first layer 30, which serves as the catalyst layer, may be composed of metals such as C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, as well as oxides or hydroxides thereof. It may or may not contain at least one of platinum group metals, platinum group metal oxides, platinum group metal hydroxides, and alloys containing platinum group metals. Preferred examples of combinations of elements to be included in the second layer include the combinations listed for the first layer. The combination of the first and second layers may have the same composition but different composition ratios, or may have different compositions.

[0416] The thickness of the catalyst layer (combined thickness of the catalyst layer and the intermediate layer) is preferably 0.01 μm to 20 μm. A thickness of 0.01 μm or greater allows for full catalytic performance. A thickness of 20 μm or less minimizes detachment from the substrate, allowing for a robust catalyst layer. A thickness of 0.05 μm to 15 μm is more preferred. A thickness of 0.1 μm to 10 μm is even more preferred. A thickness of 0.2 μm to 8 μm is even more preferred.

[0417] As the thickness of the electrode, that is, the total thickness of the electrode substrate for electrolysis and the catalyst layer, from the perspective of the handleability of the electrode, it is preferably 315 μm or less, more preferably 220 μm or less, further preferably 170 μm or less, further more preferably 150 μm or less, particularly preferably 145 μm or less, further preferably 140 μm or less, further preferably 138 μm or less, and further preferably 135 μm or less. If it is 135 μm or less, good handleability can be obtained. In addition, from the same aspect as above, it is preferably 130 μm or less, more preferably less than 130 μm, further preferably 115 μm or less, and further preferably 65 μm or less. The lower limit is not particularly limited, and is preferably 1 μm or more. From a practical perspective, it is more preferably 5 μm or more, and more preferably 20 μm or more. It should be noted that the thickness of the electrode can be measured by using a digital thickness gauge (Mitutoyo Co., Ltd., with a minimum display of 0.001 mm). The thickness of the electrolysis electrode substrate is measured in the same manner as the thickness of the electrode. The thickness of the catalyst layer can be determined by subtracting the thickness of the electrolysis electrode substrate from the thickness of the electrode.

[0418] (Method for Manufacturing Electrode for Electrolysis)

[0419] Next, one embodiment of a method for manufacturing the electrode for electrolysis 100 will be described in detail.

[0420] In this embodiment, the first layer 20 and preferably the second layer 30 are formed on the electrolysis electrode substrate by firing (thermal decomposition) of the coating under an oxygen atmosphere, or by ion plating, coating, thermal spraying, etc., thereby manufacturing the electrolysis electrode 100. Among them, thermal decomposition, plating, and ion plating are preferred because they can form a catalyst layer while suppressing the deformation of the electrolysis electrode substrate. Furthermore, from the perspective of productivity, plating and thermal decomposition are more preferred. This manufacturing method of the present embodiment can achieve high productivity of the electrolysis electrode 100. Specifically, in the case of the thermal decomposition method, the catalyst layer is formed on the electrolysis electrode substrate through a coating step of applying a coating liquid containing a catalyst, a drying step of drying the coating liquid, and a thermal decomposition step of thermal decomposition. Here, thermal decomposition refers to heating a metal salt as a precursor and decomposing it into a metal or metal oxide and a gaseous substance. The decomposition products will vary depending on the type of metal used, the type of salt, the atmosphere for thermal decomposition, etc., but many metals have a tendency to easily form oxides in an oxidizing atmosphere. In the industrial manufacturing process of electrodes for electrolysis, thermal decomposition usually takes place in air, and in most cases metal oxides or metal hydroxides are formed.

[0421] (Formation of the First Layer of the Anode)

[0422] (Coating process)

[0423] The first layer 20 is formed by applying a solution containing a metal salt of at least one of ruthenium, iridium, and titanium (a first coating solution) to the electrolytic electrode substrate and then thermally decomposing (firing) the solution in the presence of oxygen. The ruthenium, iridium, and titanium contents of the first coating solution are substantially equal to those of the first layer 20.

[0424] The metal salt may be any of chlorides, nitrates, sulfates, metal alkoxides, or other salts. The solvent for the first coating solution can be selected according to the type of metal salt, and water and alcohols such as butanol can be used. Water or a mixed solvent of water and an alcohol is preferred. The total metal concentration in the first coating solution containing the dissolved metal salt is not particularly limited; however, it is preferably in the range of 10 to 150 g / L to ensure the thickness of the coating formed by a single coating.

[0425] As a method for applying the first coating liquid to the electrolysis electrode substrate 10, a dipping method in which the electrolysis electrode substrate 10 is immersed in the first coating liquid, a method of applying the first coating liquid with a brush, a roller method using a sponge-like roller impregnated with the first coating liquid, and an electrostatic coating method in which the electrolysis electrode substrate 10 and the first coating liquid are sprayed with opposite charges are used. Among them, the roller method and the electrostatic coating method are preferred because they have excellent industrial productivity.

[0426] (Drying process, thermal decomposition process)

[0427] After applying the first coating liquid to the electrolytic electrode substrate 100, the liquid is dried at a temperature of 10 to 90°C and thermally decomposed in a firing furnace heated to 350 to 650°C. During the drying and thermal decomposition, a pre-firing process at 100 to 350°C may be performed as needed. The drying, pre-firing, and thermal decomposition temperatures can be appropriately selected based on the composition of the first coating liquid and the type of solvent. A long thermal decomposition time per cycle is preferred; from the perspective of electrode productivity, it is preferably 3 to 60 minutes, and more preferably 5 to 20 minutes.

[0428] The above-mentioned coating, drying and thermal decomposition cycles are repeated to form the coating (first layer 20) to a predetermined thickness. After forming the first layer 20, if necessary, further heating after calcining for a long time can further improve the stability of the first layer 20.

[0429] (Formation of the Second Layer of the Anode)

[0430] The second layer 30 is formed as needed, for example, by applying a solution containing a palladium compound and a platinum compound or a solution containing a ruthenium compound and a titanium compound (second coating solution) onto the first layer 20 and then thermally decomposing the solution in the presence of oxygen.

[0431] (Formation of the First Layer of the Cathode by Thermal Decomposition Method)

[0432] (Coating process)

[0433] The first layer 20 is obtained by applying a solution containing various combinations of metal salts (first coating solution) onto an electrolytic electrode substrate and then thermally decomposing (firing) the solution in the presence of oxygen. The metal content in the first coating solution is substantially equal to that in the first layer 20 .

[0434] The metal salt may be any of chlorides, nitrates, sulfates, metal alkoxides, or other salts. The solvent for the first coating solution can be selected according to the type of metal salt, and water, alcohols such as ethanol and butanol, and the like can be used. Water or a mixed solvent of water and an alcohol is preferred as the solvent. The total metal concentration in the first coating solution containing the dissolved metal salt is not particularly limited; however, it is preferably in the range of 10 to 150 g / L to ensure the thickness of the coating formed by a single coating.

[0435] As a method for applying the first coating liquid to the electrolysis electrode substrate 10, a dipping method in which the electrolysis electrode substrate 10 is immersed in the first coating liquid, a method of applying the first coating liquid with a brush, a roller method using a sponge-like roller impregnated with the first coating liquid, and an electrostatic coating method in which the electrolysis electrode substrate 10 and the first coating liquid are sprayed with opposite charges are used. Among them, the roller method and the electrostatic coating method are preferred because they have excellent industrial productivity.

[0436] (Drying process, thermal decomposition process)

[0437] After the first coating liquid is applied to the electrolysis electrode substrate 10, it is dried at a temperature of 10 to 90°C and thermally decomposed in a firing furnace heated to 350 to 650°C. During the drying and thermal decomposition, a pre-firing process at 100 to 350°C may be performed as needed. The drying, pre-firing, and thermal decomposition temperatures can be appropriately selected based on the composition of the first coating liquid and the type of solvent. A long thermal decomposition time per cycle is preferred; from the perspective of electrode productivity, it is preferably 3 to 60 minutes, and more preferably 5 to 20 minutes.

[0438] The coating, drying, and thermal decomposition cycles described above are repeated to form the coating (first layer 20) to a predetermined thickness. After forming the first layer 20, the stability of the first layer 20 can be further improved by further calcining for a longer period of time as needed and then heating at a temperature of 350°C to 650°C for 1 to 90 minutes.

[0439] (Formation of the Intermediate Layer)

[0440] The intermediate layer is formed as needed, for example, by applying a solution containing a palladium compound or a platinum compound (second coating solution) to the substrate and then thermally decomposing it in the presence of oxygen. Alternatively, the nickel oxide intermediate layer can be formed on the substrate surface by simply heating the substrate at a temperature between 300°C and 580°C for 1 to 60 minutes without applying the solution.

[0441] (Formation of the First Layer of the Cathode by Ion Plating)

[0442] The first layer 20 can also be formed by ion plating.

[0443] One example involves irradiating a ruthenium metal target with electron beams while securing the substrate within a chamber. The evaporated ruthenium metal particles become positively charged in the plasma within the chamber and deposit on the negatively charged substrate. The plasma atmosphere is composed of argon and oxygen, and the ruthenium deposits on the substrate as ruthenium oxide.

[0444] (Formation of the First Layer of the Cathode by Plating)

[0445] The first layer 20 can also be formed by plating.

[0446] For example, by using the substrate as a cathode and performing electroplating in an electrolyte solution containing nickel and tin, an alloy plating layer of nickel and tin can be formed.

[0447] (Formation of the First Layer of the Cathode by Thermal Spraying)

[0448] The first layer 20 can also be formed by thermal spraying.

[0449] As an example, by plasma spraying nickel oxide particles onto a substrate, a catalyst layer composed of a mixture of metallic nickel and nickel oxide can be formed.

[0450] The electrolysis electrode of this embodiment can be used in an integrated manner with a separator such as an ion exchange membrane or a microporous membrane. Therefore, it can be used as a membrane-integrated electrode, eliminating the need to replace the cathode and anode when replacing the electrode, significantly improving operating efficiency.

[0451] The electrolysis electrode of this embodiment forms a laminate with a separator such as an ion exchange membrane or a microporous membrane, thereby integrating the separator and electrode. This allows electrolysis performance to be equal to or even improved upon that of a new product. The separator is not particularly limited as long as it can form a laminate with the electrode, and is described in detail below.

[0452] [Ion exchange membrane]

[0453] The ion exchange membrane comprises: a membrane body comprising a hydrocarbon polymer or a fluorine-containing polymer having ion exchange groups; and a coating layer provided on at least one surface of the membrane body. The coating layer comprises inorganic particles and a binder, and the specific surface area of ​​the coating layer is 0.1 to 10 m 2 For the ion exchange membrane of this structure, the gas generated during electrolysis has little effect on the electrolytic performance, and can exert stable electrolytic performance.

[0454] The above-mentioned ion exchange membrane has an ion exchange group (-SO3 - The sulfonic acid layer having the group represented by (hereinafter also referred to as "sulfonic acid group") and the ion exchange group (-CO2 - The carboxylic acid layer preferably further comprises a reinforcing core material from the viewpoint of strength and dimensional stability.

[0455] The inorganic particles and the binder will be described in detail below in the section describing the coating layer.

[0456] Figure 2 The ion exchange membrane 1 includes a membrane body 10 made of a hydrocarbon polymer or a fluorine-containing polymer having ion exchange groups, and coating layers 11 a and 11 b formed on both surfaces of the membrane body 10 .

[0457] In the ion exchange membrane 1, the membrane body 10 includes a sulfonic acid layer 3 and a carboxylic acid layer 2, and the strength and dimensional stability are enhanced by the reinforcing core material 4. The ion exchange membrane 1 includes the sulfonic acid layer 3 and the carboxylic acid layer 2 and is therefore suitable for use as an ion exchange membrane.

[0458] It should be noted that the ion exchange membrane may also have only one of the sulfonic acid layer and the carboxylic acid layer. In addition, the ion exchange membrane does not necessarily need to be reinforced by the reinforcing core material, and the configuration state of the reinforcing core material is not limited to Figure 2 example.

[0459] (Membrane body)

[0460] First, the membrane body 10 constituting the ion exchange membrane 1 will be described.

[0461] The membrane body 10 has a function of selectively permeating cations and may be composed of a hydrocarbon polymer or a fluorine-containing polymer having ion exchange groups. The structure and material thereof are not particularly limited, and appropriate structures and materials may be selected as appropriate.

[0462] The hydrocarbon polymer or fluorine-containing polymer having ion-exchange groups in the membrane body 10 can be obtained, for example, from a hydrocarbon polymer or fluorine-containing polymer having an ion-exchange group precursor that can be converted into an ion-exchange group by hydrolysis or the like. Specifically, for example, a polymer having a main chain composed of a fluorinated hydrocarbon, having groups (ion-exchange group precursors) as side chains that can be converted into ion-exchange groups by hydrolysis or the like, and capable of melt processing (hereinafter referred to as "fluorine-containing polymer (a)") can be used to prepare a precursor of the membrane body 10, and then the ion-exchange group precursor can be converted into an ion-exchange group to obtain the membrane body 10.

[0463] The fluorine-containing polymer (a) can be produced, for example, by copolymerizing at least one monomer selected from the following Group 1 with at least one monomer selected from the following Group 2 and / or the following Group 3. Alternatively, the fluorine-containing polymer (a) can be produced by homopolymerizing one monomer selected from any one of the following Group 1, the following Group 2, and the following Group 3.

[0464] As monomers of the first group, for example, fluorinated vinyl compounds can be mentioned. Examples of fluorinated vinyl compounds include vinyl fluoride, tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, trifluoroethylene, chlorotrifluoroethylene, and perfluoroalkyl vinyl ether. In particular, when an ion exchange membrane is used as the membrane for alkaline electrolysis, the fluorinated vinyl compound is preferably a perfluoromonomer, preferably a perfluoromonomer selected from the group consisting of tetrafluoroethylene, hexafluoropropylene, and perfluoroalkyl vinyl ether.

[0465] As monomers of the second group, for example, vinyl compounds having a functional group that can be converted into a carboxylic acid type ion exchange group (carboxylic acid group) can be cited. As vinyl compounds having a functional group that can be converted into a carboxylic acid group, for example, CF2=CF(OCF2CYF) can be cited. s -O(CZF) t-COOR, etc. (here, s represents an integer of 0 to 2, t represents an integer of 1 to 12, Y and Z each independently represent F or CF3, and R represents a lower alkyl group. A lower alkyl group is, for example, an alkyl group having 1 to 3 carbon atoms.)

[0466] Among these, CF2=CF(OCF2CYF) is preferred. n -O(CF2) m -COOR wherein n represents an integer of 0 to 2, m represents an integer of 1 to 4, Y represents F or CF3, and R represents CH3, C2H5, or C3H7.

[0467] It should be noted that when an ion exchange membrane is used as a cation exchange membrane for alkaline electrolysis, it is preferred to use at least a perfluoro compound as a monomer. However, since the alkyl group of the ester group (refer to R above) is removed from the polymer at the time of hydrolysis, the alkyl group (R) may not be a perfluoroalkyl group in which all hydrogen atoms are replaced by fluorine atoms.

[0468] As the monomer of the second group, among the above, the monomers shown below are more preferable.

[0469] CF2=CFOCF2-CF(CF3)OCF2COOCH3,

[0470] CF2=CFOCF2CF(CF3)O(CF2)2COOCH3,

[0471] CF2=CF[OCF2-CF(CF3)]2O(CF2)2COOCH3,

[0472] CF2=CFOCF2CF(CF3)O(CF2)3COOCH3,

[0473] CF2=CFO(CF2)2COOCH3、

[0474] CF2=CFO(CF2)3COOCH3.

[0475] Examples of monomers in Group 3 include vinyl compounds having a functional group that can be converted into a sulfone-type ion exchange group (sulfonic acid group). Preferred examples of vinyl compounds having a functional group that can be converted into a sulfonic acid group include monomers represented by CF2=CFO-X-CF2-SO2F (where X represents a perfluoroalkylene group). Specific examples thereof include the following monomers.

[0476] CF2=CFOCF2CF2SO2F、

[0477] CF2=CFOCF2CF(CF3)OCF2CF2SO2F,

[0478] CF2=CFOCF2CF(CF3)OCF2CF2CF2SO2F,

[0479] CF2=CF(CF2)2SO2F,

[0480] CF2=CFO[CF2CF(CF3)O]2CF2CF2SO2F,

[0481] CF2=CFOCF2CF(CF2OCF3)OCF2CF2SO2F.

[0482] Among these, CF2=CFOCF2CF(CF3)OCF2CF2CF2SO2F and CF2=CFOCF2CF(CF3)OCF2CF2SO2F are more preferable.

[0483] Copolymers obtained from these monomers can be produced using polymerization methods developed for the homopolymerization and copolymerization of ethylene fluoride, particularly general polymerization methods used for tetrafluoroethylene. For example, in non-aqueous methods, polymerization can be carried out using an inert solvent such as a perfluorocarbon or chlorofluorocarbon in the presence of a free radical polymerization initiator such as a perfluorocarbon peroxide or an azo compound at a temperature of 0 to 200°C and a pressure of 0.1 to 20 MPa.

[0484] In the above-mentioned copolymerization, the type and ratio of the combination of the above-mentioned monomers are not particularly limited, and are selected and determined according to the type and amount of the functional groups that are desired to be imparted to the obtained fluorine-containing polymer. For example, in the case of forming a fluorine-containing polymer containing only carboxylic acid groups, at least one monomer is selected from the above-mentioned first group and second group respectively for copolymerization. In addition, in the case of forming a fluorine-containing polymer containing only sulfonic acid groups, at least one monomer is selected from the above-mentioned first group and third group respectively for copolymerization. In addition, in the case of forming a fluorine-containing polymer with carboxylic acid groups and sulfonic acid groups, at least one monomer is selected from the above-mentioned first group, second group and third group respectively for copolymerization. In this case, copolymers consisting of the above-mentioned first group and second group, and copolymers consisting of the above-mentioned first group and third group are polymerized respectively, and then mixed, thereby obtaining the target fluorine-containing polymer. In addition, the mixing ratio of each monomer is not particularly limited, and in the case of increasing the amount of functional groups per unit polymer, it is sufficient to increase the ratio of monomers selected from the above-mentioned second group and third group.

[0485] The total ion exchange capacity of the fluorinated copolymer is not particularly limited, but is preferably 0.5 to 2.0 mg equivalent / g, more preferably 0.6 to 1.5 mg equivalent / g. The total ion exchange capacity refers to the equivalent of exchange groups per unit weight of the dry resin and can be measured by neutralization titration or the like.

[0486] Ion exchange membrane 1 comprises a laminated sulfonic acid layer 3 comprising a fluorinated polymer having sulfonic acid groups and a laminated carboxylic acid layer 2 comprising a fluorinated polymer having carboxylic acid groups in membrane body 10. This layered membrane body 10 further enhances the permselectivity of cations such as sodium ions.

[0487] When the ion exchange membrane 1 is placed in an electrolytic cell, it is usually placed so that the sulfonic acid layer 3 is located on the anode side of the electrolytic cell and the carboxylic acid layer 2 is located on the cathode side of the electrolytic cell.

[0488] The sulfonic acid layer 3 is preferably made of a material with low electrical resistance and is preferably thicker than the carboxylic acid layer 2 in terms of film strength. The sulfonic acid layer 3 is preferably 2 to 25 times thicker than the carboxylic acid layer 2, more preferably 3 to 15 times thicker.

[0489] The carboxylic acid layer 2 preferably has high anion exclusion properties even when the membrane thickness is thin. The anion exclusion property referred to here refers to the property of preventing anions from entering or permeating the ion exchange membrane 1. To improve the anion exclusion property, it is effective to configure a carboxylic acid layer with a smaller ion exchange capacity than the sulfonic acid layer.

[0490] As the fluorine-containing polymer used for the sulfonic acid layer 3, for example, a polymer obtained by using CF2=CFOCF2CF(CF3)OCF2CF2SO2F as a monomer of the third group is suitable.

[0491] As the fluorine-containing polymer used for the carboxylic acid layer 2, for example, a polymer obtained by using CF2=CFOCF2CF(CF2)O(CF2)2COOCH3 as the monomer of the second group is suitable.

[0492] (Coating layer)

[0493] The ion exchange membrane has a coating layer on at least one surface of the membrane body. Figure 2 As shown, in the ion exchange membrane 1 , coating layers 11 a and 11 b are formed on both surfaces of a membrane body 10 , respectively.

[0494] The coating layer contains inorganic particles and a binder.

[0495] The average particle size of the inorganic particles is more preferably 0.90 μm or greater. When the average particle size of the inorganic particles is 0.90 μm or greater, the durability against not only gas adhesion but also impurities is greatly improved. That is, by increasing the average particle size of the inorganic particles while satisfying the above-mentioned specific surface area value, a particularly significant effect can be obtained. Due to the satisfaction of this average particle size and specific surface area, irregular inorganic particles are preferred. Inorganic particles obtained by melting or by crushing raw ore can be used. Preferably, inorganic particles obtained by crushing raw ore can be suitably used.

[0496] The average particle size of the inorganic particles may be 2 μm or less. If the average particle size of the inorganic particles is 2 μm or less, the membrane can be prevented from being damaged by the inorganic particles. The average particle size of the inorganic particles is more preferably 0.90 to 1.2 μm.

[0497] Here, the average particle size can be measured using a particle size distribution meter ("SALD2200" manufactured by Shimadzu Corporation).

[0498] The inorganic particles are preferably irregular in shape. This further improves resistance to impurities. Furthermore, the inorganic particles preferably have a wide particle size distribution.

[0499] The inorganic particles preferably contain at least one inorganic substance selected from the group consisting of oxides, nitrides, and carbides of Group IV elements of the periodic table. From the perspective of durability, zirconium oxide particles are more preferred.

[0500] The inorganic particles are preferably inorganic particles produced by pulverizing raw ore of the inorganic particles, or spherical particles having a uniform particle size obtained by melting and refining raw ore of the inorganic particles.

[0501] As the raw ore pulverization method, it is not particularly limited, and ball mill, bead mill, colloid mill, cone mill, disc mill, edge mill, pulverizing mill, hammer mill, particle mill, VSI mill, Wiley pulverizer, roller mill, jet mill etc. can be enumerated. In addition, preferably after pulverization, clean, now as cleaning method, preferably carry out acid treatment. Thus, it is possible to reduce impurities such as iron attached to the surface of the inorganic particles.

[0502] The coating layer preferably includes a binder. The binder is a component that holds the inorganic particles on the surface of the ion exchange membrane to form the coating layer. From the perspective of resistance to the electrolyte or electrolysis products, the binder preferably includes a fluorine-containing polymer.

[0503] As adhesive, from the aspect of the resistance of the product produced by the electrolyte or electrolysis and the adhesiveness on the surface of the ion exchange membrane, it is more preferably a fluorine-containing polymer with a carboxylic acid group or a sulfonic acid group. In the case where a coating layer is set on the layer (sulfonic acid layer) comprising the fluorine-containing polymer with a sulfonic acid group, as the adhesive of the coating layer, it is further preferred to use a fluorine-containing polymer with a sulfonic acid group. In addition, in the case where a coating layer is set on the layer (carboxylic acid layer) comprising the fluorine-containing polymer with a carboxylic acid group, as the adhesive of the coating layer, it is further preferred to use a fluorine-containing polymer with a carboxylic acid group.

[0504] The content of the inorganic particles in the coating layer is preferably 40 to 90% by mass, more preferably 50 to 90% by mass, and the content of the binder is preferably 10 to 60% by mass, more preferably 10 to 50% by mass.

[0505] The distribution density of the coating layer in the ion exchange membrane is preferably 2 In the case where the ion exchange membrane has a concavo-convex surface, the distribution density of the coating layer is preferably 0.05 to 2 mg per 1 cm 2 0.5 to 2 mg.

[0506] The method for forming the coating layer is not particularly limited, and a known method can be used. For example, a method in which inorganic particles are dispersed in a solution containing a binder and the resulting coating solution is applied by spraying or the like can be mentioned.

[0507] (Reinforced core material)

[0508] The ion exchange membrane preferably has a reinforcing core material disposed inside the membrane body.

[0509] The reinforcing core material enhances the strength and dimensional stability of the ion exchange membrane. By placing the reinforcing core material within the membrane body, the membrane's expansion and contraction can be controlled to a desired range. This prevents the membrane from expanding or contracting beyond necessary levels during electrolysis, maintaining excellent dimensional stability over extended periods.

[0510] The composition of the reinforcing core material is not particularly limited; for example, it can be formed by spinning a yarn called a reinforcing yarn. The reinforcing yarn herein refers to a member constituting the reinforcing core material, and refers to a yarn that can impart the desired dimensional stability and mechanical strength to the ion exchange membrane and can be stably present in the ion exchange membrane. By using a reinforcing core material spun from this reinforcing yarn, it is possible to impart even greater dimensional stability and mechanical strength to the ion exchange membrane.

[0511] The materials of the reinforcing core material and the reinforcing yarn used therein are not particularly limited, but are preferably materials resistant to acids, alkalis, etc. Since heat resistance and chemical resistance are required for a long time, fibers composed of fluorine-containing polymers are preferably used.

[0512] As the fluorine-containing polymer for strengthening the core material, for example, polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-ethylene copolymer (ETFE), tetrafluoroethylene-hexafluoropropylene copolymer, chlorotrifluoroethylene-ethylene copolymer and vinylidene fluoride polymer (PVDF) etc. can be mentioned. Among these, from the aspect of heat resistance and chemical resistance, it is particularly preferred to use the fiber consisting of polytetrafluoroethylene.

[0513] The diameter of the reinforcing yarn used to reinforce the core material is not particularly limited, but is preferably 20 to 300 denier, more preferably 50 to 250 denier. The weave density (the number of picks per unit length) is preferably 5 to 50 strands / inch. The method of reinforcing the core material is not particularly limited, and examples include woven fabrics, non-woven fabrics, and knitted fabrics, with woven fabrics being preferred. Furthermore, the thickness of the woven fabric is preferably 30 to 250 μm, more preferably 30 to 150 μm.

[0514] The woven or knitted fabric can be made of monofilament, multifilament or yarns thereof, slit yarn, etc., and can be made of various weaving methods such as plain weave, leno weave, knit, groove weave, and crepe stripe weave.

[0515] The weaving method and arrangement of the reinforcing core material in the membrane body are not particularly limited and can be appropriately arranged in consideration of the size and shape of the ion exchange membrane, the desired physical properties of the ion exchange membrane, the usage environment, and the like.

[0516] For example, a reinforcing core material can be arranged along a prescribed direction of the membrane body, but from the perspective of dimensional stability, it is preferred to arrange the reinforcing core material along a prescribed first direction, and to arrange other reinforcing core materials along a second direction roughly perpendicular to the first direction. By arranging a plurality of reinforcing core materials in a roughly straight manner inside the longitudinal membrane body of the membrane body, it is possible to impart better dimensional stability and mechanical strength in multiple directions. For example, it is preferred to weave a reinforcing core material (warp) arranged in the longitudinal direction and a reinforcing core material (weft) arranged in the transverse direction into the surface of the membrane body. From the perspective of dimensional stability, mechanical strength and ease of manufacture, it is more preferred to: make the warp and weft alternately float and sink and beat up to form a plain weave; twist two warps while weaving them into the weft; square weave woven by beating up the same number of wefts for two or more warps that are aligned and arranged; and so on.

[0517] It is particularly preferred to configure the reinforcing core material in two directions, the MD direction (Machine Direction direction, longitudinal) and the TD direction (Transverse Direction direction, transverse) of the ion exchange membrane. That is, it is preferably woven flat in the MD direction and the TD direction. Here, the MD direction refers to the direction (flow direction) in which the membrane body and various core materials (for example, reinforcing core materials, reinforcing yarns, sacrificial yarns described later) are conveyed in the manufacturing process of the ion exchange membrane described later, and the TD direction refers to the direction roughly perpendicular to the MD direction. In addition, the yarn woven along the MD direction is called MD yarn, and the yarn woven along the TD direction is called TD yarn. Typically, the ion exchange membranes used for electrolysis are mostly rectangular, with the length direction being the MD direction and the width direction being the TD direction. By weaving in a reinforcing core material as an MD yarn and a reinforcing core material as a TD yarn, it is possible to impart more excellent dimensional stability and mechanical strength in multiple directions.

[0518] The arrangement interval of the reinforcing core members is not particularly limited, and they can be appropriately arranged in consideration of the desired physical properties of the ion exchange membrane, the usage environment, and the like.

[0519] The opening ratio of the reinforcing core material is not particularly limited, but is preferably 30% or more, more preferably 50% or more and 90% or less. Regarding the opening ratio, it is preferably 30% or more from the perspective of the electrochemical properties of the ion exchange membrane, and preferably 90% or less from the perspective of the mechanical strength of the ion exchange membrane.

[0520] The opening ratio of the reinforcing core material is the ratio (B / A) of the total surface area (B) through which substances such as ions (electrolyte and cations contained therein (e.g., sodium ions)) can pass, relative to the area (A) of any one surface of the membrane body. The total surface area (B) through which substances such as ions can pass is the total area of ​​the region of the ion exchange membrane where cations, electrolyte, etc. are not blocked by the reinforcing core material contained in the ion exchange membrane.

[0521] Figure 3 This is a schematic diagram for explaining the aperture ratio of the reinforcing core material constituting the ion exchange membrane. Figure 3 A portion of the ion exchange membrane is enlarged to illustrate only the arrangement of the reinforcing core materials 21 and 22 in this region, with other components omitted from illustration.

[0522] The total area (B) of the area (A) through which substances such as ions can pass can be calculated by subtracting the total area (C) of the reinforcing core material from the area (A) of the region (the region surrounded by the longitudinally arranged reinforcing core material 21 and the transversely arranged reinforcing core material 22, where the area (A) includes the area of ​​the reinforcing core material. That is, the aperture ratio can be calculated using the following formula (I).

[0523] Opening ratio=(B) / (A)=((A)-(C)) / (A)…(I)

[0524] Among reinforcing core materials, flat yarns or highly oriented monofilaments containing PTFE are particularly preferred from the perspectives of chemical resistance and heat resistance. Specifically, a flat yarn obtained by cutting a high-strength porous sheet made of PTFE into a tape-shaped shape is more preferred, or a reinforcing core material using highly oriented monofilaments made of PTFE, with a plain weave of 50 to 300 denier, a weave density of 10 to 50 strands / inch, and a thickness of 50 to 100 μm is more preferred. The aperture ratio of the ion exchange membrane containing this reinforcing core material is more preferably 60% or greater.

[0525] Examples of the shape of the reinforcing yarn include round yarns and ribbon-shaped yarns.

[0526] (Connecting hole)

[0527] The ion exchange membrane preferably has continuous pores inside the membrane body.

[0528] Connecting pores are holes that serve as channels for the ions and electrolyte generated during electrolysis. Furthermore, connecting pores are tubular holes formed within the membrane body, created by the dissolution of the sacrificial core material (or sacrificial wire) described below. The shape and diameter of the connecting pores can be controlled by selecting the shape and diameter of the sacrificial core material (or sacrificial wire).

[0529] The formation of the through holes in the ion exchange membrane ensures the mobility of the electrolyte during electrolysis. The shape of the through holes is not particularly limited and can be adapted to the shape of the sacrificial core material used to form the through holes according to the production method described below.

[0530] The interconnecting holes are preferably formed so as to alternately pass through the anode side (sulfonic acid layer side) and cathode side (carboxylic acid layer side) of the reinforcing core material. This structure allows ions (e.g., sodium ions) transported through the electrolyte filling the interconnecting holes on the cathode side of the reinforcing core material to flow toward the cathode side of the reinforcing core material. As a result, the flow of cations is not hindered, further reducing the resistance of the ion exchange membrane.

[0531] The communicating pores may be formed in only one predetermined direction of the membrane body constituting the ion exchange membrane, but are preferably formed in both the longitudinal and lateral directions of the membrane body in order to exhibit more stable electrolytic performance.

[0532] [Manufacturing method]

[0533] As a preferred method for producing an ion exchange membrane, there can be mentioned a method comprising the following steps (1) to (6).

[0534] (1) Step: A step of producing a fluorine-containing polymer having an ion-exchange group or an ion-exchange group precursor capable of becoming an ion-exchange group by hydrolysis.

[0535] (2) Step: A step of weaving at least a plurality of reinforcing core materials and sacrificial filaments soluble in acid or alkali and forming continuous pores as needed to obtain a reinforcing material having sacrificial filaments arranged between adjacent reinforcing core materials.

[0536] (3) Step: a step of forming a membrane from the fluorine-containing polymer having an ion-exchange group or an ion-exchange group precursor capable of becoming an ion-exchange group by hydrolysis.

[0537] (4) Step: A step of embedding the reinforcing material in the membrane as needed to obtain a membrane body having the reinforcing material disposed therein.

[0538] Step (5): A step of hydrolyzing the membrane body obtained in step (4) (hydrolysis step).

[0539] Step (6): A step of providing a coating layer on the film body obtained in step (5) (coating step).

[0540] Hereinafter, each step will be described in detail.

[0541] (1) Process: Process for producing fluorine-containing polymers

[0542] In step (1), a fluorine-containing polymer is produced using the raw material monomers described in Groups 1 to 3. To control the ion exchange capacity of the fluorine-containing polymer, the mixing ratio of the raw material monomers can be adjusted during the production of the fluorine-containing polymer forming each layer.

[0543] (2) Process: Manufacturing process of reinforcement materials

[0544] The reinforcing material refers to a woven fabric, etc., made from reinforcing yarns. By embedding the reinforcing material within the membrane, a reinforcing core material is formed. When an ion exchange membrane having interconnecting pores is formed, sacrificial yarns are also woven into the reinforcing material. The sacrificial yarns preferably comprise 10-80% by mass of the overall reinforcing material, more preferably 30-70% by mass. Weaving in sacrificial yarns can also prevent the reinforcing core material from misaligning.

[0545] The sacrificial yarn is soluble in the membrane manufacturing process or electrolysis environment, and rayon, polyethylene terephthalate (PET), cellulose, polyamide, etc. are used. In addition, polyvinyl alcohol having a thickness of 20 to 50 denier and composed of monofilaments or multifilaments is also preferred.

[0546] It should be noted that in step (2), by adjusting the arrangement of the reinforcing core material and the sacrificial wire, the opening ratio, the arrangement of the communicating holes, etc. can be controlled.

[0547] (3) Process: Membrane process

[0548] In step (3), the fluorine-containing polymer obtained in step (1) is formed into a film using an extruder. The film may have a single-layer structure, a two-layer structure of a sulfonic acid layer and a carboxylic acid layer as described above, or a multilayer structure of three or more layers.

[0549] As a method of forming a membrane, for example, the following method can be mentioned.

[0550] A method in which a fluorinated polymer having a carboxylic acid group and a fluorinated polymer having a sulfonic acid group are separately formed into membranes.

[0551] A method of preparing a composite film by coextruding a fluorinated polymer having a carboxylic acid group and a fluorinated polymer having a sulfonic acid group.

[0552] It should be noted that the films may be two or more. In addition, co-extrusion of different types of films is preferred because it helps to improve the bonding strength of the interface.

[0553] (4) Process: Process of obtaining the membrane body

[0554] In step (4), the reinforcing material obtained in step (2) is embedded in the interior of the membrane obtained in step (3), thereby obtaining a membrane body having the reinforcing material therein.

[0555] As a preferred method for forming the membrane body, there are the following: (i) a fluorine-containing polymer having a carboxylic acid precursor (for example, a carboxylate functional group) located on the cathode side (the layer composed of which is hereinafter referred to as the first layer) and a fluorine-containing polymer having a sulfonic acid precursor (for example, a sulfonyl fluoride functional group) (the layer composed of which is hereinafter referred to as the second layer) are formed into a membrane by co-extrusion, and a heating source and a vacuum source are used as needed to stack them in the order of reinforcing material, second layer / first layer composite membrane on a flat plate or cylinder having a large number of pores on the surface, separated by air-permeable heat-resistant release paper, and each polymer is laminated in the order of reinforcing material, second layer / first layer composite membrane, and a heating source and a vacuum source are used as needed to laminate them in the order of reinforcing material, second layer / first layer composite membrane, and a heating source and a vacuum source are used ... (ii) a method in which the air between the layers is removed by reducing pressure at a temperature at which the composite film is melted and the layers are integrated at the same time; (iii) a method in which a fluorine-containing polymer having a sulfonic acid group precursor (third layer) is separately formed into a film in advance in a separate operation from the second layer / first layer composite film, a heating source and a vacuum source are used as needed, and a third layer of film, a reinforcing core material, and a composite film consisting of the second layer / first layer are layered in this order on a flat plate or cylinder having a large number of pores on the surface, with air-permeable heat-resistant release paper interposed therebetween, and the air between the layers is removed by reducing pressure at a temperature at which the polymers are melted and the layers are integrated at the same time.

[0556] Here, coextrusion of the first layer and the second layer helps to improve the bonding strength at the interface.

[0557] In addition, compared with the pressurized pressing method, the integration method under reduced pressure has the characteristic of increasing the thickness of the third layer on the reinforcing material. In addition, since the reinforcing material is fixed to the inner surface of the membrane body, it has the performance of fully maintaining the mechanical strength of the ion exchange membrane.

[0558] It should be noted that the lamination transformation described here is an example, and a suitable lamination pattern (for example, combination of layers, etc.) may be appropriately selected in consideration of the desired layer composition or physical properties of the film body, and then co-extrusion may be performed.

[0559] It should be noted that in order to further improve the electrical performance of the ion exchange membrane, a fourth layer composed of a fluorine-containing polymer having both a carboxylic acid precursor and a sulfonic acid precursor can be further sandwiched between the first layer and the second layer, or a fourth layer composed of a fluorine-containing polymer having both a carboxylic acid precursor and a sulfonic acid precursor can be used instead of the second layer.

[0560] The fourth layer may be formed by separately preparing a fluorine-containing polymer having a carboxylic acid group precursor and a fluorine-containing polymer having a sulfonic acid group precursor and then mixing them, or by using a copolymer of a monomer having a carboxylic acid group precursor and a monomer having a sulfonic acid group precursor.

[0561] When the fourth layer is composed of an ion exchange membrane, the first and fourth layers can be formed into a co-extruded film, and the third and second layers can be formed into films separately from them, and then stacked using the above method; or the first layer / fourth layer / second layer can be formed into films by co-extrusion at one time.

[0562] In this case, the direction in which the extruded film flows is the MD direction. In this way, a membrane body including a fluorine-containing polymer having ion exchange groups can be formed on the reinforcing material.

[0563] In addition, the ion exchange membrane preferably has a prominent part, i.e., a convex portion, consisting of a fluoropolymer with a sulfonic acid group on the surface side consisting of a sulfonic acid layer. As the method for forming this convex portion, there is no particular limitation, and the known method of forming a convex portion on the resin surface can be adopted. Specifically, for example, the method of embossing the surface of the membrane body can be cited. For example, when the above-mentioned composite membrane and reinforcing material etc. are integrated, the above-mentioned convex portion can be formed by using a release paper that has been embossed in advance. When forming a convex portion by embossing, the control of the height and configuration density of the convex portion can be carried out by controlling the embossed shape (shape of the release paper) that is transferred.

[0564] (5) Hydrolysis process

[0565] In step (5), the membrane body obtained in step (4) is hydrolyzed to convert the ion exchange group precursor into an ion exchange group (hydrolysis step).

[0566] In addition, in step (5), the sacrificial filaments contained in the membrane body can be dissolved and removed with an acid or alkali, thereby forming dissolution pores in the membrane body. It should be noted that the sacrificial filaments may remain in the connecting pores and not be completely dissolved and removed. In addition, the sacrificial filaments remaining in the connecting pores can be dissolved and removed by the electrolyte when the ion exchange membrane is subjected to electrolysis.

[0567] The sacrificial wire is soluble in acid or alkali during the manufacturing process of the ion exchange membrane and in an electrolytic environment, and the sacrificial wire is dissolved to form a continuous pore at that location.

[0568] The step (5) can be performed by immersing the membrane body obtained in the step (4) in a hydrolysis solution containing an acid or an alkali. As the hydrolysis solution, for example, a mixed solution containing KOH and DMSO (dimethyl sulfoxide) can be used.

[0569] The mixed solution preferably contains 2.5 to 4.0 N KOH and 25 to 35 mass % DMSO.

[0570] The hydrolysis temperature is preferably 70 to 100°C. The higher the temperature, the greater the apparent thickness. 75 to 100°C is more preferred.

[0571] The hydrolysis time is preferably 10 to 120 minutes. A longer time increases the apparent thickness. A more preferred time is 20 to 120 minutes.

[0572] Here, the step of dissolving the sacrificial filaments to form the communicating holes will be described in more detail. Figure 4 (a) and (b) are schematic diagrams for explaining a method of forming continuous pores in an ion exchange membrane.

[0573] exist Figure 4 In (a) and (b), only the reinforcing wire 52, the sacrificial wire 504a, and the communicating hole 504 formed by the sacrificial wire 504a are shown, and other members such as the membrane body are omitted from the illustration.

[0574] First, the reinforcing material is made by weaving in the reinforcing filaments 52 that form the reinforcing core material in the ion exchange membrane and the sacrificial filaments 504a that form the communicating pores 504 in the ion exchange membrane. Furthermore, the communicating pores 504 are formed by dissolving the sacrificial filaments 504a in step (5).

[0575] According to the above method, the weaving method of the reinforcing yarns 52 and the sacrificial yarns 504a can be adjusted according to the arrangement of the reinforcing core material and the communication holes in the membrane body of the ion exchange membrane, which is very convenient.

[0576] exist Figure 4 In (a), a plain-woven reinforcing material is shown in which reinforcing yarns 52 and sacrificial yarns 504a are woven in both the longitudinal and transverse directions of the paper. However, the arrangement of the reinforcing yarns 52 and sacrificial yarns 504a in the reinforcing material can be changed as needed.

[0577] (6) Coating process

[0578] In step (6), a coating liquid containing inorganic particles obtained by crushing or melting raw ore and a binder is prepared, and the coating liquid is applied to the surface of the ion exchange membrane obtained in step (5) and dried to form a coating layer.

[0579] As the binder, a binder obtained by hydrolyzing a fluorine-containing polymer having an ion exchange group precursor with an aqueous solution containing dimethyl sulfoxide (DMSO) and potassium hydroxide (KOH) and then immersing the polymer in hydrochloric acid to replace the counter ions of the ion exchange group with H + (For example, a fluorine-containing polymer having a carboxyl group or a sulfonic group.) This is preferred because it is easily soluble in water or ethanol described later.

[0580] The binder is dissolved in a solution of water and ethanol. The preferred volume ratio of water to ethanol is 10:1 to 1:10, more preferably 5:1 to 1:5, and even more preferably 2:1 to 1:2. Inorganic particles are dispersed in the resulting solution using a ball mill to form a coating solution. The average particle size of the particles can be adjusted by adjusting the dispersion time and rotation speed. The preferred blending amounts of the inorganic particles and binder are as described above.

[0581] The concentrations of the inorganic particles and the binder in the coating solution are not particularly limited, but a dilute coating solution is preferred so that the surface of the ion exchange membrane can be uniformly coated.

[0582] In addition, when dispersing the inorganic particles, a surfactant can be added to the dispersion. As the surfactant, a nonionic surfactant is preferred, for example, HS-210, NS-210, P-210, E-212 manufactured by NOF Corporation can be mentioned.

[0583] The obtained coating liquid is applied to the surface of the ion exchange membrane by spray coating or roll coating to obtain an ion exchange membrane.

[0584] [Microporous membrane]

[0585] As described above, the microporous membrane of the present embodiment is not particularly limited as long as it can form a laminate with the electrolysis electrode, and various microporous membranes can be applied.

[0586] The porosity of the microporous membrane of the present embodiment is not particularly limited, and may be, for example, 20 to 90, and preferably 30 to 85. The porosity can be calculated, for example, by the following formula.

[0587] Porosity = (1 - (weight of the membrane in a dry state) / (weight calculated from the volume calculated from the thickness, width, and length of the membrane and the density of the membrane material)) × 100

[0588] The average pore diameter of the microporous membrane of this embodiment is not particularly limited, but may be, for example, 0.01 μm to 10 μm, preferably 0.05 μm to 5 μm. The average pore diameter can be determined by, for example, cutting the membrane perpendicularly to the thickness direction and observing the cross section using FE-SEM. The diameter of the observed pores is measured at approximately 100 points and the average is calculated.

[0589] The thickness of the microporous membrane of the present embodiment is not particularly limited, and may be, for example, 10 μm to 1000 μm, preferably 50 μm to 600 μm. The thickness can be measured using, for example, a micrometer (manufactured by Mitutoyo Co., Ltd.).

[0590] Specific examples of the microporous membrane include Zirfon Perl UTP 500 manufactured by Agfa (also referred to as Zirfon membrane in this embodiment), and microporous membranes described in International Publication No. 2013-183584 and International Publication No. 2016-203701.

[0591] [laminated body]

[0592] The laminate of this embodiment comprises the electrolysis electrode of this embodiment and a separator or power supply in contact with the electrolysis electrode. Due to this configuration, the laminate of this embodiment can improve the efficiency of electrode replacement in an electrolytic cell, thereby exhibiting excellent electrolysis performance even after replacement.

[0593] That is, according to the laminate of this embodiment, when replacing the electrodes, the electrodes can be replaced by the same simple operation as replacing the separators without complicated operations such as peeling off the electrodes fixed to the electrolytic cell, thereby significantly improving work efficiency.

[0594] Furthermore, the laminate of the present invention can maintain or improve electrolysis performance at the time of a new product. Furthermore, in the case of a new electrolysis cell equipped only with a power supply (i.e., an electrode without a catalyst layer), simply attaching the electrolysis electrode of this embodiment to the power supply allows it to function as an electrode, thereby significantly reducing or completely eliminating the need for catalyst coating.

[0595] The laminate of the present embodiment can be stored in a state of being wound around a polyvinyl chloride tube or the like (in a roll or the like) and transported to a customer, etc., and thus can be handled very easily.

[0596] In addition, various substrates described later, such as a deteriorated electrode (ie, an existing electrode) or an electrode not coated with a catalyst, can be applied as the power supply in this embodiment.

[0597] In the laminate of the present embodiment, the force applied per unit mass and per unit area of ​​the electrolysis electrode to the separator or the power supply is preferably 0.08 N / (mg·cm 2 ) or more, more preferably 0.1N / (mg·cm 2 ) or more, more preferably 0.14N / (mg·cm 2 ) or more, and from the perspective of easier handling in large-scale (for example, 1.5 m × 2.5 m) conditions, 0.2 N / (mg·cm 2 The upper limit is not particularly limited, but is preferably 1.6 N / (mg·cm 2 ) or less, more preferably less than 1.6N / (mg·cm 2 ), more preferably less than 1.5N / (mg·cm 2 ), and more preferably 1.2 N / mg·cm 2 Below, more preferably 1.20 N / mg·cm 2 Below. More preferably, it is 1.1N / mg·cm 2 Below, more preferably 1.10 N / mg·cm 2 Below, particularly preferably 1.0 N / mg·cm 2 Below, particularly preferably 1.00 N / mg·cm 2 the following.

[0598] [Wound body]

[0599] The wound body of this embodiment includes the electrode for electrolysis of this embodiment or the laminate of this embodiment. That is, the wound body of this embodiment is formed by winding the electrode for electrolysis of this embodiment or the laminate of this embodiment. By winding the electrode for electrolysis of this embodiment or the laminate of this embodiment to reduce its size, as in the wound body of this embodiment, it is possible to further improve handling.

[0600] [Electrolyzer]

[0601] The electrolytic cell of this embodiment includes the electrolysis electrode of this embodiment. Hereinafter, an embodiment of the electrolytic cell will be described in detail, taking the case of performing salt electrolysis using an ion exchange membrane as a diaphragm as an example.

[0602] [Electrolysis unit]

[0603] Figure 5 is a cross-sectional view of the electrolysis unit 1.

[0604] The electrolytic unit 1 includes an anode chamber 10, a cathode chamber 20, a partition wall 30 provided between the anode chamber 10 and the cathode chamber 20, an anode 11 provided in the anode chamber 10, and a cathode 21 provided in the cathode chamber 20. If necessary, a reverse current absorber 18 provided in the cathode chamber may also be provided, and the reverse current absorber 18 has a substrate 18a and a reverse current absorption layer 18b formed on the substrate 18a. The anode 11 and the cathode 21 belonging to one electrolytic unit 1 are electrically connected to each other. In other words, the electrolytic unit 1 includes the following cathode structure. The cathode structure 40 includes a cathode chamber 20, a cathode 21 provided in the cathode chamber 20, and a reverse current absorber 18 provided in the cathode chamber 20, and the reverse current absorber 18 is as follows: Figure 9As shown, it has a substrate 18a and a reverse current absorption layer 18b formed on the substrate 18a, and the cathode 21 and the reverse current absorption layer 18b are electrically connected. The cathode chamber 20 further has a current collector 23, a support 24 that supports the current collector, and a metal elastic body 22. The metal elastic body 22 is arranged between the current collector 23 and the cathode 21. The support 24 is arranged between the current collector 23 and the partition wall 30. The current collector 23 is electrically connected to the cathode 21 via the metal elastic body 22. The partition wall 30 is electrically connected to the current collector 23 via the support 24. Therefore, the partition wall 30, the support 24, the current collector 23, the metal elastic body 22 and the cathode 21 are electrically connected. The cathode 21 and the reverse current absorption layer 18b are electrically connected. The cathode 21 and the reverse current absorption layer can be directly connected or indirectly connected via the current collector, the support, the metal elastic body or the partition wall. The entire surface of the cathode 21 is preferably covered with a catalyst layer used for the reduction reaction. Alternatively, the electrical connection may be achieved by directly attaching the partition wall 30 to the support 24, directly attaching the support 24 to the current collector 23, or directly attaching the current collector 23 to the metal elastic body 22, with the cathode 21 stacked on the metal elastic body 22. Examples of methods for directly attaching these components include welding. Alternatively, the reverse current absorber 18, cathode 21, and current collector 23 may be collectively referred to as the cathode structure 40.

[0605] Figure 6 It is a cross-sectional view of two adjacent electrolytic units 1 in the electrolytic cell 4 . Figure 7 An electrolysis cell 4 is shown. Figure 8 FIG4 shows the process of assembling the electrolytic cell 4. Figure 6 As shown, the electrolysis unit 1, the cation exchange membrane 2, and the electrolysis unit 1 are arranged in series. The ion exchange membrane 2 is arranged between the anode chamber of one electrolysis unit 1 and the cathode chamber of the other electrolysis unit 1 in the two adjacent electrolysis units in the electrolytic cell. That is, the anode chamber 10 of the electrolysis unit 1 and the cathode chamber 20 of the adjacent electrolysis unit 1 are separated by the cation exchange membrane 2. Figure 7 As shown, the electrolytic cell 4 is composed of a plurality of electrolytic units 1 connected in series via an ion exchange membrane 2. That is, the electrolytic cell 4 is a bipolar electrolytic cell having a plurality of electrolytic units 1 arranged in series and an ion exchange membrane 2 arranged between adjacent electrolytic units 1. Figure 8 As shown, the electrolytic cell 4 is assembled by arranging a plurality of electrolytic cells 1 in series with an ion exchange membrane 2 interposed therebetween and connecting them with a pressurizer 5 .

[0606] The electrolytic cell 4 has an anode terminal 7 and a cathode terminal 6 connected to a power source. The anode 11 of the electrolytic cell 1 located at the end of the plurality of electrolytic cells 1 connected in series in the electrolytic cell 4 is electrically connected to the anode terminal 7. The cathode 21 of the electrolytic cell located at the end opposite to the anode terminal 7 of the plurality of electrolytic cells 2 connected in series in the electrolytic cell 4 is electrically connected to the cathode terminal 6. During electrolysis, the current flows from the anode terminal 7 side through the anode and cathode of each electrolytic cell 1 to the cathode terminal 6. It should be noted that an electrolytic cell having only an anode chamber (anode terminal cell) and an electrolytic cell having only a cathode chamber (cathode terminal cell) can also be configured at both ends of the connected electrolytic cells 1. In this case, the anode terminal 7 is connected to the anode terminal cell configured at one end, and the cathode terminal 6 is connected to the cathode terminal cell configured at the other end.

[0607] When electrolysis of brine is performed, brine is supplied to each anode chamber 10, and pure water or a low-concentration sodium hydroxide aqueous solution is supplied to the cathode chamber 20. Each liquid is supplied to each electrolysis unit 1 from an electrolyte supply pipe (omitted in the figure) via an electrolyte supply hose (omitted in the figure). In addition, the electrolyte and the products produced by electrolysis are recovered by an electrolyte recovery pipe (omitted in the figure). During electrolysis, sodium ions in the brine move from the anode chamber 10 of one electrolysis unit 1 to the cathode chamber 20 of the adjacent electrolysis unit 1 via the ion exchange membrane 2. As a result, the current in the electrolysis flows in the direction in which the electrolysis units 1 are connected in series. That is, the current flows from the anode chamber 10 to the cathode chamber 20 via the cation exchange membrane 2. As the brine is electrolyzed, chlorine gas is generated on the anode 11 side, and sodium hydroxide (solute) and hydrogen gas are generated on the cathode 21 side.

[0608] (Anode chamber)

[0609] The anode chamber 10 includes an anode 11 or an anode power supply 11. When the electrode for electrolysis of this embodiment is inserted into the anode side, 11 functions as an anode power supply. When the electrode for electrolysis of this embodiment is not inserted into the anode side, 11 functions as an anode. In addition, the anode chamber 10 preferably includes: an anode-side electrolyte supply unit for supplying electrolyte to the anode chamber 10; a baffle disposed above the anode-side electrolyte supply unit and disposed approximately parallel to or obliquely to the partition wall 30; and an anode-side gas-liquid separator disposed above the baffle for separating gas from the electrolyte mixed with gas.

[0610] (anode)

[0611] When the electrolysis electrode of this embodiment is not inserted into the anode side, an anode 11 is provided in the frame of the anode chamber 10. A metal electrode such as DSA (registered trademark) can be used as the anode 11. DSA is an electrode having a titanium base material whose surface is coated with oxides containing ruthenium, iridium, and titanium as components.

[0612] As the shape, any of punched metal, nonwoven fabric, foamed metal, expanded metal, porous metal foil formed by electroforming, and so-called woven mesh produced by weaving metal wires can be used.

[0613] (Anode power supply)

[0614] When the electrolysis electrode of this embodiment is inserted into the anode side, an anode power supply 11 is provided within the frame of the anode chamber 10. As the anode power supply 11, a metal electrode such as so-called DSA (registered trademark) can be used, or titanium that is not coated with a catalyst can be used. Alternatively, DSA with a reduced catalyst coating thickness can be used. Furthermore, a used anode can also be used.

[0615] As the shape, any of punched metal, nonwoven fabric, foamed metal, expanded metal, porous metal foil formed by electroforming, and so-called woven mesh produced by weaving metal wires can be used.

[0616] (Anode side electrolyte supply unit)

[0617] The anode side electrolyte supply unit supplies electrolyte to the anode chamber 10, and is connected to the electrolyte supply pipe. The anode side electrolyte supply unit is preferably arranged below the anode chamber 10. As the anode side electrolyte supply unit, for example, a tube (dispersion pipe) having an opening formed on the surface can be used. The tube is more preferably arranged parallel to the bottom 19 of the electrolysis unit along the surface of the anode 11. The tube is connected to the electrolyte supply tube (liquid supply nozzle) that supplies electrolyte to the electrolysis unit 1. The electrolyte supplied by the liquid supply nozzle is conveyed to the electrolysis unit 1 through the tube, and is supplied to the inside of the anode chamber 10 from the opening provided on the surface of the tube. It is preferred that the tube is arranged parallel to the bottom 19 of the electrolysis unit along the surface of the anode 11, so that the electrolyte can be uniformly supplied to the inside of the anode chamber 10.

[0618] (Anode side gas-liquid separation section)

[0619] The anode side gas-liquid separator is preferably arranged above the baffle. In electrolysis, the anode side gas-liquid separator has the function of separating the generated gas such as chlorine and the electrolyte. It should be noted that, unless otherwise stated, the above refers to Figure 5 The upward direction of the electrolytic unit 1, the downward direction is Figure 5 The electrolysis unit 1 is in a downward direction.

[0620] During electrolysis, if the generated gas and electrolyte produced in the electrolysis unit 1 become a mixed phase (gas-liquid mixed phase) and are discharged outside the system, vibration will occur due to the pressure fluctuation inside the electrolysis unit 1, sometimes causing physical damage to the ion exchange membrane. In order to suppress this phenomenon, the electrolysis unit 1 of the present embodiment is preferably provided with an anode side gas-liquid separation unit for separating gas and liquid. A defoaming plate for eliminating bubbles is preferably provided in the anode side gas-liquid separation unit. When the gas-liquid mixed phase flow passes through the defoaming plate, the bubbles burst, thereby being able to separate into electrolyte and gas. As a result, vibration during electrolysis can be prevented.

[0621] (Baffle)

[0622] The baffle is preferably arranged above the electrolyte supply portion on the anode side and is arranged approximately parallel to or obliquely to the partition wall 30. The baffle is a partition that controls the flow of the electrolyte in the anode chamber 10. By providing the baffle, the electrolyte (brine, etc.) can be internally circulated in the anode chamber 10 to make its concentration uniform. In order to produce internal circulation, the baffle is preferably arranged in a manner that separates the space near the anode 11 and the space near the partition wall 30. From this aspect, the baffle is preferably arranged to face the surfaces of the anode 11 and the partition wall 30. In the space near the anode separated by the baffle, as electrolysis proceeds, the electrolyte concentration (brine concentration) decreases, and chlorine and other generated gases are generated. As a result, a difference in specific gravity between gas and liquid is generated in the space near the anode 11 separated by the baffle and the space near the partition wall 30. By utilizing this specific gravity difference, the internal circulation of the electrolyte in the anode chamber 10 can be promoted, making the concentration distribution of the electrolyte in the anode chamber 10 more uniform.

[0623] It should be noted that although not shown Figure 5 , but a current collector may be separately provided inside the anode chamber 10. As the current collector, it may be made of the same material or structure as the current collector of the cathode chamber described later. In addition, in the anode chamber 10, the anode 11 itself may function as a current collector.

[0624] (Separation Wall)

[0625] The partition wall 30 is disposed between the anode chamber 10 and the cathode chamber 20. The partition wall 30 is sometimes referred to as a separator plate, and divides the anode chamber 10 from the cathode chamber 20. As the partition wall 30, a material known as a separator plate for electrolysis can be used, and for example, a partition wall having a nickel plate welded to the cathode side and a titanium plate welded to the anode side can be used.

[0626] (Cathode chamber)

[0627] Regarding the cathode chamber 20, when the electrolysis electrode of the present embodiment is inserted into the cathode side, 21 functions as a cathode power supply. When the electrolysis electrode of the present embodiment is not inserted into the cathode side, 21 functions as a cathode. In the case of having a reverse current absorber, the cathode or cathode power supply 21 is electrically connected to the reverse current absorber. In addition, the cathode chamber 20 also preferably has a cathode side electrolyte supply unit and a cathode side gas-liquid separation unit, similarly to the anode chamber 10. It should be noted that, among the various parts constituting the cathode chamber 20, the description is omitted for the parts that are the same as those constituting the anode chamber 10.

[0628] (cathode)

[0629] When the electrolysis electrode of the present embodiment is not inserted into the cathode side, a cathode 21 is provided in the frame of the cathode chamber 20. The cathode 21 preferably has a nickel substrate and a catalyst layer coated with the nickel substrate. As the components of the catalyst layer on the nickel substrate, metals such as Ru, C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Rh, Pd, Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and oxides or hydroxides of the metals can be enumerated. As the formation method of the catalyst layer, plating, alloy plating, dispersion composite plating, CVD, PVD, thermal decomposition and spraying can be enumerated. These methods can also be combined. The catalyst layer may have multiple layers and multiple elements as needed. In addition, the cathode 21 may be subjected to a reduction treatment as needed. It should be noted that, as the substrate of the cathode 21, nickel, a nickel alloy, or a substrate obtained by plating nickel on iron or stainless steel may also be used.

[0630] As the shape, any of punched metal, nonwoven fabric, foamed metal, expanded metal, porous metal foil formed by electroforming, and so-called woven mesh produced by weaving metal wires can be used.

[0631] (Cathode current supply)

[0632] When the electrolysis electrode of the present embodiment is inserted into the cathode side, a cathode current supply body 21 is provided in the frame of the cathode chamber 20. The cathode current supply body 21 can be coated with a catalyst component. The catalyst component can be a substance that was originally used as a cathode and remains. As the component of the catalyst layer, metals such as Ru, C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Rh, Pd, Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and oxides or hydroxides of the metals can be cited. As the formation method of the catalyst layer, plating, alloy plating, dispersion composite plating, CVD, PVD, thermal decomposition and spraying can be cited. These methods can also be combined. The catalyst layer may have multiple layers and multiple elements as needed. It should be noted that as the base material of the cathode current supply 21, nickel, nickel alloy, or nickel-plated iron or stainless steel may also be used.

[0633] Alternatively, the power supply 21 may be made of nickel, a nickel alloy, or iron or stainless steel plated with nickel without a catalyst coating.

[0634] As the shape, any of punched metal, nonwoven fabric, foamed metal, expanded metal, porous metal foil formed by electroforming, and so-called woven mesh produced by weaving metal wires can be used.

[0635] (Reverse current absorption layer)

[0636] As the material of the reverse current absorption layer, a material having a redox potential lower than that of the element used in the cathode catalyst layer can be selected, for example, nickel, iron, etc.

[0637] (Current Collector)

[0638] The cathode chamber 20 preferably includes a current collector 23 . This improves the current collection effect. In this embodiment, the current collector 23 is preferably a porous plate and is arranged substantially parallel to the surface of the cathode 21 .

[0639] The current collector 23 is preferably made of a conductive metal such as nickel, iron, copper, silver, or titanium. The current collector 23 may also be a mixture, alloy, or composite oxide of these metals. It should be noted that the shape of the current collector 23 can be any shape as long as it functions as a current collector, and may be a plate or mesh.

[0640] (Metal Elastomer)

[0641] By providing the metal elastic body 22 between the current collector 23 and the cathode 21, each cathode 21 of the plurality of electrolytic cells 1 connected in series is pressed against the ion exchange membrane 2, shortening the distance between each anode 11 and each cathode 21. This reduces the voltage applied to the entire plurality of electrolytic cells 1 connected in series. This reduction in voltage can reduce power consumption. Furthermore, by providing the metal elastic body 22, when the laminate comprising the electrolytic electrode of the present invention is placed in the electrolytic cell, the pressing pressure generated by the metal elastic body 22 can stably maintain the electrolytic electrode in a fixed position.

[0642] As the metal elastic body 22, a spring member such as a coil or a coil, a cushioning pad, etc. can be used. As the metal elastic body 22, a suitable metal elastic body can be appropriately adopted in consideration of the stress of pressing the ion exchange membrane, etc. The metal elastic body 22 can be arranged on the surface of the collector 23 on the cathode chamber 20 side, or on the surface of the partition wall on the anode chamber 10 side. Usually, the two chambers are divided in such a way that the cathode chamber 20 is smaller than the anode chamber 10. Therefore, from the perspective of the strength of the frame, it is preferred that the metal elastic body 22 is arranged between the collector 23 of the cathode chamber 20 and the cathode 21. In addition, the metal elastic body 23 is preferably composed of a conductive metal such as nickel, iron, copper, silver, or titanium.

[0643] (Support)

[0644] The cathode chamber 20 preferably includes a support 24 that electrically connects the current collector 23 and the partition wall 30. This allows efficient flow of current.

[0645] The support 24 is preferably made of a conductive metal such as nickel, iron, copper, silver, or titanium. The support 24 may be in any shape as long as it can support the current collector 23, and may be in the form of a rod, a plate, or a mesh. For example, the support 24 is in the form of a plate. A plurality of supports 24 are positioned between the separator 30 and the current collector 23. The plurality of supports 24 are arranged so that their surfaces are parallel to one another. The supports 24 are positioned approximately perpendicular to the separator 30 and the current collector 23.

[0646] (Anode side gasket, cathode side gasket)

[0647] The anode side gasket is preferably arranged on the surface of the frame constituting the anode chamber 10. The cathode side gasket is preferably arranged on the surface of the frame constituting the cathode chamber 20. The electrolysis units are connected to each other in such a manner that the anode side gasket of one electrolysis unit and the cathode side gasket of the adjacent electrolysis unit sandwich the ion exchange membrane 2 (see Figure 5 、 6 ) These gaskets can provide airtightness to the connection points when a plurality of electrolytic cells 1 are connected in series via the ion exchange membrane 2 .

[0648] A gasket refers to a component that seals between an ion exchange membrane and an electrolytic cell. As a specific example of a gasket, a picture frame-shaped rubber sheet with an opening in the center can be cited. The gasket is required to be resistant to corrosive electrolytes or generated gases and to be able to be used for a long time. Therefore, from the perspective of chemical resistance and hardness, vulcanized products or peroxide cross-linked products of ethylene propylene diene monomer (EPDM rubber) and ethylene propylene diene monomer (EPM rubber) are usually used as gaskets. In addition, as needed, a gasket coated with a fluorine-based resin such as polytetrafluoroethylene (PTFE) or tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) in the area in contact with the liquid (liquid contact portion) can also be used. As long as these gaskets have openings so as not to hinder the flow of the electrolyte, their shapes are not particularly limited. For example, a picture frame-shaped gasket is attached to the periphery of each opening of the anode chamber frame constituting the anode chamber 10 or the cathode chamber frame constituting the cathode chamber 20 using an adhesive. For example, when two electrolytic cells 1 are connected via an ion exchange membrane 2 (see Figure 6 ), the electrolytic cells 1 to which the gaskets are attached are fastened via the ion exchange membrane 2. This can prevent the electrolyte, alkali metal hydroxides generated by electrolysis, chlorine, hydrogen, etc. from leaking to the outside of the electrolytic cell 1.

[0649] (Ion exchange membrane 2)

[0650] The ion exchange membrane 2 is as described in the above-mentioned section of the ion exchange membrane.

[0651] (Water Electrolysis)

[0652] The electrolytic cell of the present embodiment is an electrolytic cell for performing water electrolysis, and has the following structure: the ion exchange membrane in the electrolytic cell for performing salt electrolysis is replaced with a microporous membrane. In addition, the raw material supplied is water, which is different from the electrolytic cell for performing salt electrolysis. As for other structures, the electrolytic cell for performing water electrolysis can also adopt the same structure as the electrolytic cell for performing salt electrolysis. In the case of salt electrolysis, chlorine is produced in the anode chamber, so the material of the anode chamber uses titanium, but in the case of water electrolysis, only oxygen is produced in the anode chamber, so the same material as the cathode chamber can be used. For example, nickel and the like can be mentioned. In addition, the anode coating is preferably a catalyst coating for oxygen generation. Examples of catalyst coatings include metals, oxides, hydroxides, etc. of platinum group metals and transition metals. For example, elements such as platinum, iridium, palladium, ruthenium, nickel, cobalt, and iron can be used.

[0653] <Second embodiment>

[0654] Here, refer to Figures 22-42 The second embodiment of the present invention will be described in detail.

[0655] [laminated body]

[0656] A laminate according to a second embodiment (hereinafter referred to as "the present embodiment" in the section "Second embodiment") comprises an electrolysis electrode and a diaphragm or a power supply in contact with the electrolysis electrode, wherein the force applied per unit mass and per unit area of ​​the electrolysis electrode to the diaphragm or the power supply is less than 1.5 N / mg·cm 2 Due to such a configuration, the laminate of the present embodiment can improve the work efficiency when the electrodes in the electrolytic cell are replaced, and can also exhibit excellent electrolytic performance after replacement.

[0657] That is, according to the laminate of this embodiment, when replacing electrodes, the electrodes can be replaced by the same simple operation as replacing the separators without complicated operations such as peeling off the existing electrodes fixed to the electrolytic cell, thereby significantly improving work efficiency.

[0658] Furthermore, the laminate of the present invention can maintain or improve electrolytic performance at the time of new products. Therefore, the electrodes fixed to existing new electrolysis cells that function as anodes and cathodes only need to function as power supplies, significantly reducing or completely eliminating the need for catalyst coating.

[0659] The laminate of the present embodiment can be stored in a state of being wound around a polyvinyl chloride tube or the like (in a roll or the like) and transported to a customer, etc., and thus can be handled very easily.

[0660] In addition, as the power supply in this embodiment, various substrates described later, such as a deteriorated electrode (ie, an existing electrode) and an electrode not coated with a catalyst, can be applied.

[0661] Furthermore, the laminate of this embodiment may partially have a fixing portion as long as it has the above-mentioned configuration. That is, when the laminate of this embodiment has a fixing portion, the portion without the fixing portion is subjected to measurement, and the force applied per unit mass / unit area of ​​the obtained electrolytic electrode is less than 1.5 N / mg·cm 2 That's it.

[0662] [Electrolysis Electrode]

[0663] The electrolysis electrode of this embodiment has a force of less than 1.5 N / mg·cm per unit mass and per unit area in order to achieve good handling properties and good adhesion to separators such as ion exchange membranes and microporous membranes, and to power supply bodies (degraded electrodes and electrodes not coated with catalysts). 2 , preferably 1.2N / mg·cm 2 Below, more preferably 1.20N / mg·cm2 More preferably, it is 1.1 N / mg·cm 2 Below, more preferably 1.10 N / mg·cm 2 Below, more preferably 1.0 N / mg·cm 2 Below, more preferably 1.00 N / mg·cm 2 the following.

[0664] From the perspective of further improving electrolytic performance, it is preferred to exceed 0.005 N / (mg·cm 2 ), more preferably 0.08N / (mg·cm 2 ) or more, more preferably 0.1 N / mg·cm 2 More preferably, 0.14 N / (mg·cm 2 ) or more. From the perspective of facilitating handling in large-scale applications (e.g., 1.5 m × 2.5 m), 0.2 N / (mg·cm 2 )above.

[0665] The applied force can be brought into the above range by, for example, appropriately adjusting the aperture ratio, electrode thickness, arithmetic mean surface roughness, etc., which will be described later. More specifically, for example, increasing the aperture ratio tends to reduce the applied force, while decreasing the aperture ratio tends to increase the applied force.

[0666] In addition, the mass per unit area is preferably 48 mg / cm2 from the perspectives of good handling, good adhesion to separators such as ion exchange membranes and microporous membranes, deteriorated electrodes, and non-catalyst-coated power supplies, as well as economic efficiency. 2 Less than 30 mg / cm 2 Below, more preferably 20 mg / cm 2 From the perspective of handling, adhesion and economic efficiency, 15 mg / cm 2 The lower limit is not particularly limited, but is, for example, 1 mg / cm 2 about.

[0667] The mass per unit area can be adjusted to the above range by, for example, appropriately adjusting the aperture ratio, electrode thickness, etc., as described later. More specifically, for example, if the thickness is the same, increasing the aperture ratio tends to reduce the mass per unit area, while decreasing the aperture ratio tends to increase the mass per unit area.

[0668] The applied force can be measured by the following method (i) or (ii), and the details are as described in the Examples. Regarding the applied force, the value obtained by the measurement of method (i) (also referred to as "applied force (1)") and the value obtained by the measurement of method (ii) (also referred to as "applied force (2)") may be the same or different, but both values ​​are less than 1.5 N / mg·cm 2 .

[0669] [Method (i)]

[0670] A nickel plate (1.2 mm thick, 200 mm square) sandblasted with alumina grain number 320, an ion exchange membrane (170 mm square) coated with inorganic particles and a binder on both sides of a perfluorocarbon polymer membrane containing ion exchange groups (details of the ion exchange membrane are described in the Examples), and an electrode sample (130 mm square) were sequentially stacked. The stack was thoroughly immersed in pure water, and excess water adhering to the surface of the stack was removed to obtain a sample for measurement. The arithmetic mean surface roughness (Ra) of the sandblasted nickel plate was 0.5 to 0.8 μm. The specific method for calculating the arithmetic mean surface roughness (Ra) is described in the Examples.

[0671] At a temperature of 23±2°C and a relative humidity of 30±5%, use a tension-compression tester to vertically elevate only the electrode sample in the test sample at a rate of 10 mm / minute. Measure the load when the electrode sample is vertically elevated by 10 mm. Perform this measurement three times and calculate the average value.

[0672] The average value was divided by the area of ​​the overlapped portion of the electrode sample and the ion exchange membrane and the mass of the portion of the electrode sample overlapping the ion exchange membrane to calculate the force applied per unit mass and unit area (1) (N / mg·cm 2 ).

[0673] Regarding the force (1) applied per unit mass and unit area obtained by method (i), the force (1) applied is less than 1.5 N / mg·cm from the viewpoint of obtaining good handling properties and good adhesion to separators such as ion exchange membranes or microporous membranes, deteriorated electrodes, and power supply bodies not coated with catalysts. 2 , preferably 1.2N / mg·cm 2 Below, more preferably 1.20N / mg·cm 2 Below, more preferably 1.1 N / mg·cm 2 less than 1.10 N / mg·cm 2 Below, more preferably 1.0 N / mg·cm2 Below, more preferably 1.00 N / mg·cm 2 In addition, from the perspective of further improving electrolytic performance, the applied force (1) is preferably greater than 0.005N / (mg·cm 2 ), more preferably 0.08N / (mg·cm 2 ) or more, more preferably 0.1N / (mg·cm 2 ) or more, and further preferably 0.14 N / (mg·cm 2 ) or more, and more preferably 0.2N / (mg·cm 2 )above.

[0674] If the electrolysis electrode of this embodiment satisfies the applied force (1), it can be used as an integrated body with a separator such as an ion exchange membrane or a microporous membrane, or a power supply (i.e., as a laminate). Therefore, when the electrode is updated, it is not necessary to replace the cathode and anode fixed to the electrolysis unit by welding or other methods, thereby greatly improving the working efficiency. In addition, by using the electrolysis electrode of this embodiment as a laminate integrated with an ion exchange membrane or a microporous membrane, or a power supply, the electrolysis performance can be made equal to or further improved compared to the performance of the new product.

[0675] When shipping a new electrolysis unit, conventional electrodes attached to the electrolysis unit are catalytically coated. However, simply combining the uncatalytically coated electrodes with the electrolysis electrodes of this embodiment allows them to be used as electrodes. This significantly reduces or eliminates the manufacturing process and amount of catalyst required for catalytic coating. Conventional electrodes with significantly reduced or no catalytic coating can be electrically connected to the electrolysis electrodes of this embodiment, functioning as current supply sources.

[0676] [Method (ii)]

[0677] A nickel plate (1.2 mm thick, 200 mm square, the same nickel plate as in method (i) above) sandblasted with alumina with grain number 320 and an electrode sample (130 mm square) were stacked in this order. The stack was thoroughly immersed in pure water, and excess water adhering to the surface of the stack was removed to obtain a measurement sample. Using a tensile-compression tester, only the electrode sample of the measurement sample was vertically elevated at a rate of 10 mm / minute at a temperature of 23 ± 2°C and a relative humidity of 30 ± 5%. The load applied when the electrode sample was elevated 10 mm in the vertical direction was measured. This measurement was repeated three times, and the average value was calculated.

[0678] The average value was divided by the area of ​​the overlapping portion of the electrode sample and the nickel plate and the mass of the electrode sample in the portion overlapping the nickel plate to calculate the adhesive force per unit mass per unit area (2) (N / mg·cm 2 ).

[0679] Regarding the force (2) applied per unit mass and unit area obtained by method (ii), the force (2) applied is less than 1.5 N / mg·cm from the viewpoint of obtaining good handling properties and good adhesion to separators such as ion exchange membranes or microporous membranes, deteriorated electrodes, and power supply bodies not coated with catalysts. 2 , preferably 1.2N / mg·cm 2 Below, more preferably 1.20N / mg·cm 2 Below, more preferably 1.1 N / mg·cm 2 less than 1.10 N / mg·cm 2 Below, more preferably 1.0 N / mg·cm 2 Below, more preferably 1.00 N / mg·cm 2 From the perspective of further improving electrolytic performance, the applied force (2) is preferably greater than 0.005 N / (mg·cm 2 ), more preferably 0.08N / (mg·cm 2 ) or more, more preferably 0.1N / (mg·cm 2 ) or more, and further preferably 0.14 N / (mg·cm 2 )above.

[0680] If the electrolysis electrode of this embodiment satisfies the applied force (2), it can be stored in a state wound around a polyvinyl chloride tube (in a roll, etc.) and transported to a customer, etc., making handling very easy. In addition, by attaching the electrolysis electrode of this embodiment to a deteriorated existing electrode to form a laminate, the electrolysis performance can be made equal to or even improved from that of a new electrode.

[0681] When the electrolysis electrode of this embodiment has a wide elastic deformation range, the thickness of the electrolysis electrode is preferably 315 μm or less, more preferably 220 μm or less, even more preferably 170 μm or less, even more preferably 150 μm or less, particularly preferably 145 μm or less, even more preferably 140 μm or less, even more preferably 138 μm or less, and even more preferably 135 μm or less, from the perspective of achieving better handling properties and better adhesion to separators such as ion exchange membranes or microporous membranes, degraded electrodes, and non-catalyst-coated power supplies. A thickness of 135 μm or less provides good handling properties. Furthermore, from the same perspective as above, the thickness is preferably 130 μm or less, more preferably less than 130 μm, even more preferably 115 μm or less, and even more preferably 65 μm or less. The lower limit is not particularly limited, but is preferably 1 μm or greater. From a practical perspective, it is more preferably 5 μm or greater, and even more preferably 20 μm or greater. It should be noted that, in this embodiment, the term "wide elastic deformation region" refers to the fact that, after the electrolysis electrode is wound into a wound body, warping due to the winding is less likely to occur after the body is unwound. Furthermore, the thickness of the electrolysis electrode, when including the catalyst layer described below, refers to the combined thickness of the electrolysis electrode substrate and the catalyst layer.

[0682] The electrolysis electrode of the present embodiment preferably includes an electrolysis electrode substrate and a catalyst layer. The thickness (gauge thickness) of the electrolysis electrode substrate is not particularly limited. From the perspective of obtaining good handling properties, having good adhesion to diaphragms such as ion exchange membranes or microporous membranes, degraded electrodes (electrical feeders), and electrodes (electrical feeders) not coated with catalysts, being able to be appropriately rolled into a roll, being well bent, and being easy to handle under large sizes (for example, 1.5m×2.5m), it is preferably 300μm or less, more preferably 205μm or less, further preferably 155μm or less, further more preferably 135μm or less, further preferably 125μm or less, further preferably 120μm or less, further preferably 100μm or less, and from the perspective of handling properties and economic efficiency, it is further preferably 50μm or less. The lower limit is not particularly limited, for example, 1μm, preferably 5μm, and more preferably 15μm.

[0683] In the present embodiment, a liquid is preferably mixed between a diaphragm such as an ion exchange membrane or a microporous membrane and an electrode, or a metal porous plate or a metal plate (i.e., a power supply) such as a degraded original electrode or an electrode not coated with a catalyst and an electrode for electrolysis. Any liquid can be used as long as the liquid is a substance that generates surface tension such as water or an organic solvent. The greater the surface tension of the liquid, the greater the force applied between the diaphragm and the electrode for electrolysis, or the metal porous plate or the metal plate and the electrode for electrolysis, and therefore a liquid with a large surface tension is preferred. As liquids, the following substances can be cited (the numerical values ​​in brackets are the surface tensions of the liquid at 20°C).

[0684] Hexane (20.44 mN / m), acetone (23.30 mN / m), methanol (24.00 mN / m), ethanol (24.05 mN / m), ethylene glycol (50.21 mN / m), water (72.76 mN / m)

[0685] If the liquid has a high surface tension, the diaphragm and the electrolysis electrode, or the porous metal plate or metal plate (electrical source) and the electrolysis electrode, are integrated (forming a laminate), making electrode replacement easier. The amount of liquid between the diaphragm and the electrolysis electrode, or the porous metal plate or metal plate (electrical source) and the electrolysis electrode, is small enough to allow adhesion due to surface tension. Consequently, even if the liquid mixes with the electrolyte after being installed in the electrolysis cell of the laminate, it will not affect the electrolysis itself.

[0686] From practical aspect, as liquid, it is preferred to use a liquid having a surface tension of 24mN / m to 80mN / m such as ethanol, ethylene glycol, water. Particularly preferred water or dissolving caustic soda, potassium hydroxide, lithium hydroxide, sodium bicarbonate, saleratus, sodium carbonate, potassium carbonate etc. in water and becoming an alkaline aqueous solution. In addition, these liquids can also be made to include a surfactant and regulate the surface tension. By including a surfactant, the adhesion between the diaphragm and the electrode for electrolysis or a metal porous plate or a metal plate (electrical conductor) and the electrode for electrolysis changes, and processability can be adjusted. As a surfactant, there is no particular restriction, and any one of an ionic surfactant or a nonionic surfactant can be used.

[0687] The electrolysis electrode of this embodiment is not particularly limited. However, from the perspective of achieving good handling properties and good adhesion to separators such as ion exchange membranes or microporous membranes, deteriorated electrodes (electrical conductors), and electrodes (electrical conductors) not coated with a catalyst, the ratio measured by the following method (2) is preferably 90% or more, more preferably 92% or more. Furthermore, from the perspective of facilitating handling of large-scale electrodes (e.g., 1.5 m × 2.5 m), it is even more preferably 95% or more. The upper limit is 100%.

[0688] [Method (2)]

[0689] An ion exchange membrane (170 mm square) and an electrode sample (130 mm square) were stacked in this order. With the electrode sample facing outward, the stack was placed on the curved surface of a polyethylene tube (280 mm outer diameter) at a temperature of 23±2°C and a relative humidity of 30±5%. The stack and tube were thoroughly immersed in pure water, and any excess water adhering to the stack and tube was removed. After one minute, the area ratio (%) of the portion where the ion exchange membrane (170 mm square) and the electrode sample were in close contact was measured.

[0690] The electrode for electrolysis of this embodiment is not particularly limited. However, from the perspectives of achieving good handling properties, good adhesion to separators such as ion exchange membranes or microporous membranes, deteriorated electrodes (electrical conductors), and electrodes (electrical conductors) not coated with catalysts, and being able to be rolled up and bent well, the ratio measured by the following method (3) is preferably 75% or more, more preferably 80% or more. Furthermore, from the perspective of facilitating handling of large-scale electrodes (e.g., 1.5 m × 2.5 m), it is even more preferably 90% or more. The upper limit is 100%.

[0691] [Method (3)]

[0692] An ion exchange membrane (170 mm square) and an electrode sample (130 mm square) were stacked in this order. With the electrode sample facing outward, the stack was placed on the curved surface of a polyethylene tube (145 mm outer diameter) at a temperature of 23±2°C and a relative humidity of 30±5%. The stack and tube were thoroughly immersed in pure water, and any excess water adhering to the stack and tube was removed. After one minute, the area ratio (%) of the portion where the ion exchange membrane (170 mm square) and the electrode sample were in close contact was measured.

[0693] The electrolysis electrode of this embodiment is not particularly limited, but preferably has a porous structure from the perspectives of achieving good handling, good adhesion to separators such as ion exchange membranes or microporous membranes, degraded electrodes (electrical conductors), and electrodes (electrical conductors) not coated with catalysts, and preventing the accumulation of gases generated during electrolysis. The porosity or void ratio is preferably 5 to 90% or less. The porosity is more preferably 10 to 80%, and even more preferably 20 to 75%.

[0694] It should be noted that the porosity refers to the ratio of open areas per unit volume. The number of open areas can be calculated in various ways, depending on whether the consideration is down to the submicron level or only visible openings. In this embodiment, the volume V is calculated from the gauge thickness, width, and length of the electrode, and the weight W is then measured to calculate the porosity A using the following formula.

[0695] A=(1-(W / (V×ρ))×100

[0696] ρ is the density of the electrode material (g / cm 3 For example, in the case of nickel, it is 8.908 g / cm 3 , in the case of titanium it is 4.506 g / cm 3 The porosity can be appropriately adjusted by the following methods: if punching metal is used, the area of ​​the metal punched per unit area is changed; if metal mesh is used, the values ​​of SW (short diameter), LW (long diameter), and feed are changed; if it is a mesh, the wire diameter and mesh count of the metal fiber are changed; if electroforming is used, the pattern of the photoresist used is changed; if it is a non-woven fabric, the metal fiber diameter and fiber density are changed; if it is a foamed metal, the mold used to form the gap is changed; and so on.

[0697] Regarding the electrolysis electrode in this embodiment, from the perspective of handling, the value measured by the following method (A) is preferably 40 mm or less, more preferably 29 mm or less, further preferably 10 mm or less, and even more preferably 6.5 mm or less. The specific measurement method is as described in the Examples.

[0698] [Method (A)]

[0699] Under the conditions of a temperature of 23±2°C and a relative humidity of 30±5%, a sample consisting of a laminated ion exchange membrane and the above-mentioned electrolysis electrode was wound and fixed onto the curved surface of a vinyl chloride core material having an outer diameter of Φ32 mm. After standing for 6 hours, the electrolysis electrode was separated and placed on a horizontal plate. The vertical heights L1 and L2 of the two ends of the electrolysis electrode were measured, and their average value was used as the measured value.

[0700] The electrolysis electrode in this embodiment has a size of 50 mm × 50 mm and is subjected to a temperature of 24° C., a relative humidity of 32%, a piston speed of 0.2 cm / s, and an air flow rate of 0.4 cc / cm 2 / s (hereinafter also referred to as "measurement condition 1"), the ventilation resistance (hereinafter also referred to as "ventilation resistance 1") is preferably 24 kPa·s / m or less. A large ventilation resistance means that air is difficult to flow, which refers to a state of high density. In this state, the products produced by electrolysis remain in the electrodes, and the reaction matrix is ​​difficult to diffuse into the interior of the electrodes, so there is a tendency for the electrolysis performance (voltage, etc.) to deteriorate. In addition, there is a tendency for the concentration on the membrane surface to increase. Specifically, there is a tendency for the caustic concentration to increase on the cathode side and the supply of brine to decrease on the anode side. As a result, the product stays at a high concentration at the interface where the diaphragm contacts the electrode, and there is a tendency to cause damage to the diaphragm, and also cause a voltage increase and membrane damage on the cathode side, and damage to the membrane on the anode side. In this embodiment, in order to prevent these adverse conditions, it is preferred that the ventilation resistance is 24 kPa·s / m or less. From the same aspects as above, it is more preferred to be less than 0.19 kPa·s / m, further preferably less than 0.15 kPa·s / m, and further preferably less than 0.07 kPa·s / m.

[0701] It should be noted that in the present embodiment, if the ventilation resistance is greater than a certain value, in the case of the cathode, the NaOH produced at the electrode stays at the interface between the electrode and the diaphragm, and tends to become a high concentration; in the case of the anode, the supply of brine is reduced, and the brine concentration tends to become a low concentration. From the perspective of preventing possible damage to the diaphragm caused by such retention, it is preferably less than 0.19 kPa·s / m, more preferably below 0.15 kPa·s / m, and even more preferably below 0.07 kPa·s / m.

[0702] On the other hand, when the air resistance is low, the electrode area is reduced, resulting in a reduced electrolysis area and a tendency for electrolysis performance (voltage, etc.) to deteriorate. When the air resistance is zero, since no electrolysis electrodes are provided, the power supply functions as an electrode, and there is a tendency for electrolysis performance (voltage, etc.) to deteriorate significantly. From this perspective, the preferred lower limit value of the air resistance 1 is not particularly limited, but is preferably greater than 0 kPa·s / m, more preferably 0.0001 kPa·s / m or greater, and even more preferably 0.001 kPa·s / m or greater.

[0703] It should be noted that regarding the ventilation resistance 1, from the perspective of its measurement method, sufficient measurement accuracy may not be obtained when it is 0.07 kPa·s / m or less. From this perspective, for an electrolysis electrode with a ventilation resistance 1 of 0.07 kPa·s / m or less, the ventilation resistance (hereinafter also referred to as "ventilation resistance 2") can also be evaluated using the following measurement method (hereinafter also referred to as "measurement condition 2"). That is, the ventilation resistance 2 is measured when the electrolysis electrode has a size of 50 mm × 50 mm, a temperature of 24°C, a relative humidity of 32%, a piston speed of 2 cm / s, and a ventilation volume of 4 cc / cm 2 / s ventilation resistance.

[0704] The specific method for measuring ventilation resistance 1 and 2 is as described in the Examples.

[0705] The ventilation resistances 1 and 2 can be adjusted to the above ranges by, for example, appropriately adjusting the porosity, electrode thickness, etc., as described later. More specifically, for example, when the thickness is constant, increasing the porosity tends to decrease the ventilation resistances 1 and 2, while decreasing the porosity tends to increase the ventilation resistances 1 and 2.

[0706] As described above, the electrolysis electrode of this embodiment has a force per unit mass and per unit area of ​​less than 1.5 N / mg·cm2 applied to the diaphragm or the power supply. 2 . In this way, the electrode for electrolysis of the present embodiment contacts the diaphragm or the power supply (for example, the original anode or cathode in the electrolytic cell) with a moderate adhesive force, thereby being able to constitute a laminate with the diaphragm or the power supply. That is, there is no need to firmly bond the diaphragm or the power supply to the electrode for electrolysis by complicated methods such as thermocompression bonding. For example, even a relatively weak force such as the surface tension of water that may be contained in a diaphragm such as an ion exchange membrane or a microporous membrane can be bonded to form a laminate, so that a laminate can be easily constituted regardless of the scale. In addition, this laminate can exhibit excellent electrolytic performance, and thus the laminate of the present embodiment is suitable for electrolysis purposes, for example, it can be particularly preferably used for components of an electrolytic cell or uses involved in the renewal of the component.

[0707] Hereinafter, one form of the electrode for electrolysis according to the present embodiment will be described.

[0708] The electrolysis electrode of this embodiment preferably includes an electrolysis electrode substrate and a catalyst layer. The catalyst layer may be composed of multiple layers or a single layer structure as described below.

[0709] like Figure 22As shown, the electrolysis electrode 100 of this embodiment includes an electrolysis electrode substrate 10 and a pair of first layers 20 covering both surfaces of the electrolysis electrode substrate 10. The first layer 20 preferably covers the entire electrolysis electrode substrate 10. This facilitates improving the catalytic activity and durability of the electrolysis electrode. It should be noted that the first layer 20 may be deposited on only one surface of the electrolysis electrode substrate 10.

[0710] In addition, if Figure 22 As shown, the surface of the first layer 20 may be covered by the second layer 30. The second layer 30 preferably covers the entire first layer 20. Alternatively, the second layer 30 may be laminated on only one surface of the first layer 20.

[0711] (Electrode base material for electrolysis)

[0712] The electrolysis electrode substrate 10 is not particularly limited, and for example, nickel, nickel alloys, stainless steel, or valve metals represented by titanium can be used. It preferably contains at least one element selected from nickel (Ni) and titanium (Ti).

[0713] When stainless steel is used in a high-concentration alkaline aqueous solution, a substrate composed of nickel (Ni) is preferably used as the electrolysis electrode substrate, considering the elution of iron and chromium and the fact that the conductivity of stainless steel is about 1 / 10 of that of nickel.

[0714] Furthermore, when the electrolysis electrode substrate 10 is used in a nearly saturated, high-concentration saline solution or in a chlorine gas generating atmosphere, the material is preferably titanium having high corrosion resistance.

[0715] The shape of the electrolysis electrode substrate 10 is not particularly limited, and an appropriate shape can be selected according to the purpose. As the shape, any one of punching metal, non-woven fabric, foamed metal, expanded metal, a metal porous foil formed by electroforming, a so-called woven mesh made by weaving metal wires, etc. can be used. Among them, punching metal or expanded metal is preferred. It should be noted that electroforming refers to a technology for making a metal film of a precise pattern by combining photoengraving and electroplating. It is a method of forming a pattern on a substrate using a photoresist and electroplating the portion not protected by the resist to obtain a metal film.

[0716] The shape of the electrolytic electrode substrate has appropriate specifications depending on the distance between the anode and cathode in the electrolytic cell. While not particularly limited, expanded metal or perforated metal can be used when the distance between the anode and cathode is limited. In the case of a so-called zero-gap electrolytic cell where the ion exchange membrane and the electrodes are in contact, woven mesh made of fine wires, wire mesh, foamed metal, non-woven metal fabric, expanded metal, perforated metal, or porous metal foil can be used.

[0717] Examples of the electrolysis electrode substrate 10 include porous metal foil, metal mesh, metal nonwoven fabric, punched metal, expanded metal, and foamed metal.

[0718] As the sheet material before being processed into punched metal or expanded metal, preferably a rolled sheet material, electrolytic foil, etc. As a post-treatment, the electrolytic foil is preferably further plated with the same element as the base material to form irregularities on one or both sides.

[0719] As described above, the thickness of the electrolysis electrode substrate 10 is preferably 300 μm or less, more preferably 205 μm or less, even more preferably 155 μm or less, still more preferably 135 μm or less, even more preferably 125 μm or less, even more preferably 120 μm or less, and even more preferably 100 μm or less. From the perspective of handling and economic efficiency, it is even more preferably 50 μm or less. The lower limit is not particularly limited, but is, for example, 1 μm, preferably 5 μm, and more preferably 15 μm.

[0720] In the electrolysis electrode substrate, it is preferred to anneal the substrate in an oxidizing atmosphere to alleviate residual stress during processing. Furthermore, to improve adhesion to the catalyst layer coated on the surface, the surface of the electrolysis electrode substrate is preferably formed with irregularities using a steel grid, alumina powder, or the like, and then acid-treated to increase the surface area. Alternatively, the surface area is preferably increased by plating with the same element as the substrate.

[0721] In order to ensure close contact between the first layer 20 and the surface of the electrolysis electrode substrate 10, the electrolysis electrode substrate 10 is preferably subjected to a treatment to increase its surface area. Examples of treatments to increase the surface area include sandblasting using cut wire, steel grid, alumina grid, etc.; acid treatment using sulfuric acid or hydrochloric acid; and plating using the same element as the substrate. The arithmetic mean surface roughness (Ra) of the substrate surface is not particularly limited, but is preferably 0.05 μm to 50 μm, more preferably 0.1 to 10 μm, and even more preferably 0.1 to 8 μm.

[0722] Next, a description will be given of a case where the electrode for electrolysis of this embodiment is used as an anode for electrolysis of sodium chloride.

[0723] (First floor)

[0724] Figure 22In the embodiment of the present invention, the first layer 20 serving as the catalyst layer comprises at least one oxide selected from the group consisting of ruthenium oxide, iridium oxide, and titanium oxide. Examples of ruthenium oxides include RuO2, IrO2, and TiO2. Preferably, the first layer 20 comprises both ruthenium oxide and titanium oxide, or alternatively, comprises all three oxides, namely, ruthenium oxide, iridium oxide, and titanium oxide. This makes the first layer 20 more stable, further improving its adhesion to the second layer 30.

[0725] When the first layer 20 contains both ruthenium oxide and titanium oxide, the amount of titanium oxide contained in the first layer 20 is preferably 1 to 9 mol, more preferably 1 to 4 mol, per 1 mol of ruthenium oxide contained in the first layer 20. By setting the composition ratio of the two oxides within this range, the electrolytic electrode 100 exhibits excellent durability.

[0726] When the first layer 20 contains three oxides of ruthenium oxide, iridium oxide, and titanium oxide, the amount of iridium oxide contained in the first layer 20 is preferably 0.2 to 3 mol, more preferably 0.3 to 2.5 mol, per 1 mol of ruthenium oxide contained in the first layer 20. Furthermore, the amount of titanium oxide contained in the first layer 20 is preferably 0.3 to 8 mol, more preferably 1 to 7 mol, per 1 mol of ruthenium oxide contained in the first layer 20. By setting the composition ratio of the three oxides within this range, the electrolytic electrode 100 exhibits excellent durability.

[0727] When the first layer 20 contains at least two oxides selected from ruthenium oxide, iridium oxide, and titanium oxide, these oxides preferably form a solid solution. By forming an oxide solid solution, the electrolytic electrode 100 exhibits excellent durability.

[0728] In addition to the above-mentioned composition, any composition may be used as long as it contains at least one oxide of ruthenium oxide, iridium oxide, and titanium oxide. For example, an oxide coating containing ruthenium, iridium, tantalum, niobium, titanium, tin, cobalt, manganese, platinum, etc., known as DSA (registered trademark), may also be used as the first layer 20.

[0729] The first layer 20 does not need to be a single layer and may include multiple layers. For example, the first layer 20 may include a layer containing three oxides and a layer containing two oxides. The thickness of the first layer 20 is preferably 0.05 to 10 μm, more preferably 0.1 to 8 μm.

[0730] (Second floor)

[0731] The second layer 30 preferably contains ruthenium and titanium. This can further reduce the overvoltage of chlorine immediately after electrolysis.

[0732] The second layer 30 preferably contains palladium oxide, a solid solution of palladium oxide and platinum, or an alloy of palladium and platinum. This can further reduce the overvoltage of chlorine immediately after electrolysis.

[0733] When the second layer 30 is thick, the period during which the electrolytic performance can be maintained becomes longer. However, from the viewpoint of economic efficiency, the thickness of the second layer 30 is preferably 0.05 to 3 μm.

[0734] Next, a description will be given of a case where the electrode for electrolysis of this embodiment is used as a cathode for electrolysis of sodium chloride.

[0735] (First floor)

[0736] The components of the first layer 20 serving as the catalyst layer can include metals such as C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, and oxides or hydroxides of the metals.

[0737] It may or may not contain at least one of a platinum group metal, a platinum group metal oxide, a platinum group metal hydroxide, and an alloy containing a platinum group metal.

[0738] In the case of containing at least one of a platinum group metal, a platinum group metal oxide, a platinum group metal hydroxide, and an alloy containing a platinum group metal, the platinum group metal, the platinum group metal oxide, the platinum group metal hydroxide, and the alloy containing a platinum group metal preferably contain at least one platinum group metal of platinum, palladium, rhodium, ruthenium, and iridium.

[0739] As the platinum group metal, platinum is preferably contained.

[0740] As the platinum group metal oxide, ruthenium oxide is preferably contained.

[0741] As the platinum group metal hydroxide, ruthenium hydroxide is preferably contained.

[0742] As the platinum group metal alloy, an alloy containing platinum, nickel, iron, or cobalt is preferable.

[0743] Furthermore, if necessary, it is preferable to contain an oxide or hydroxide of a lanthanoid element as the second component. This allows the electrolytic electrode 100 to exhibit excellent durability.

[0744] The oxide or hydroxide of the lanthanoid element preferably contains at least one selected from lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, and dysprosium.

[0745] Furthermore, it is preferred to contain an oxide or hydroxide of a transition metal as a third component as necessary.

[0746] By adding the third component, the electrolysis electrode 100 exhibits more excellent durability and the electrolysis voltage can be reduced.

[0747] Examples of preferred combinations include ruthenium alone, ruthenium + nickel, ruthenium + cerium, ruthenium + lanthanum, ruthenium + lanthanum + platinum, ruthenium + lanthanum + palladium, ruthenium + praseodymium, ruthenium + praseodymium + platinum, ruthenium + praseodymium + platinum + palladium, ruthenium + neodymium, ruthenium + neodymium + platinum, ruthenium + neodymium + manganese, ruthenium + neodymium + iron, ruthenium + neodymium + cobalt, ruthenium + neodymium + zinc, ruthenium + neodymium + gallium, ruthenium + neodymium + sulfur, ruthenium + neodymium + lead, ruthenium + neodymium + nickel, ruthenium + Neodymium + copper, ruthenium + samarium, ruthenium + samarium + manganese, ruthenium + samarium + iron, ruthenium + samarium + cobalt, ruthenium + samarium + zinc, ruthenium + samarium + gallium, ruthenium + samarium + sulfur, ruthenium + samarium + lead, ruthenium + samarium + nickel, platinum + cerium, platinum + palladium + cerium, platinum + palladium + lanthanum + cerium, platinum + iridium, platinum + palladium, platinum + iridium + palladium, platinum + nickel + palladium, platinum + nickel + ruthenium, alloys of platinum and nickel, alloys of platinum and cobalt, alloys of platinum and iron, etc.

[0748] When no platinum group metals, platinum group metal oxides, platinum group metal hydroxides or alloys containing platinum group metals are contained, the main component of the catalyst is preferably nickel.

[0749] Preferably, it contains at least one of nickel metal, oxide, and hydroxide.

[0750] A transition metal may be added as a second component. The second component preferably contains at least one element selected from titanium, tin, molybdenum, cobalt, manganese, iron, sulfur, zinc, copper, and carbon.

[0751] Preferred combinations include nickel + tin, nickel + titanium, nickel + molybdenum, and nickel + cobalt.

[0752] If necessary, an intermediate layer may be provided between the first layer 20 and the electrolysis electrode substrate 10. By providing the intermediate layer, the durability of the electrolysis electrode 100 can be improved.

[0753] The intermediate layer is preferably one having an affinity for both the first layer 20 and the electrolytic electrode substrate 10. Preferred intermediate layers include nickel oxide, platinum group metals, platinum group metal oxides, and platinum group metal hydroxides. The intermediate layer can be formed by applying a solution containing components for forming the intermediate layer and then firing it. Alternatively, the substrate can be heat-treated in an air atmosphere at a temperature of 300 to 600°C to form a surface oxide layer. Alternatively, the intermediate layer can be formed using known methods such as thermal spraying and ion plating.

[0754] (Second floor)

[0755] The components of the first layer 30 serving as the catalyst layer can include metals such as C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, and oxides or hydroxides of the metals.

[0756] The second layer may contain at least one of a platinum group metal, a platinum group metal oxide, a platinum group metal hydroxide, and an alloy containing a platinum group metal, or may not contain any. Preferred combinations of elements for the second layer include the combinations listed for the first layer. The first and second layers may have the same composition but different composition ratios, or may have different compositions.

[0757] The thickness of the catalyst layer (combined thickness of the catalyst layer and the intermediate layer) is preferably 0.01 μm to 20 μm. A thickness of 0.01 μm or greater allows for full catalytic performance. A thickness of 20 μm or less minimizes detachment from the substrate, allowing for a robust catalyst layer. A thickness of 0.05 μm to 15 μm is more preferred. A thickness of 0.1 μm to 10 μm is even more preferred. A thickness of 0.2 μm to 8 μm is even more preferred.

[0758] As the thickness of the electrolysis electrode, that is, the total thickness of the electrolysis electrode substrate and the catalyst layer, from the perspective of the handleability of the electrolysis electrode, it is preferably 315 μm or less, more preferably 220 μm or less, further preferably 170 μm or less, further more preferably 150 μm or less, particularly preferably 145 μm or less, further preferably 140 μm or less, further preferably 138 μm or less, and further preferably 135 μm or less. If it is 135 μm or less, good handleability can be obtained. In addition, from the same aspect as above, it is preferably 130 μm or less, more preferably less than 130 μm, further preferably 115 μm or less, and further preferably 65 μm or less. The lower limit is not particularly limited, but is preferably 1 μm or more. From a practical perspective, it is more preferably 5 μm or more, and more preferably 20 μm or more. It should be noted that the thickness of the electrode can be measured by using a digital thickness gauge (Mitutoyo Co., Ltd., with a minimum display of 0.001 mm). The thickness of the electrolysis electrode substrate can be measured in the same manner as the thickness of the electrolysis electrode. The thickness of the catalyst layer can be determined by subtracting the thickness of the electrolysis electrode substrate from the thickness of the electrolysis electrode.

[0759] (Method for Manufacturing Electrode for Electrolysis)

[0760] Next, one embodiment of a method for manufacturing the electrode for electrolysis 100 will be described in detail.

[0761] In the present embodiment, the first layer 20, preferably the second layer 30, is formed on the electrolysis electrode substrate by firing (thermal decomposition) of the coating under an oxygen atmosphere, or by methods such as ion plating, plating, and thermal spraying, thereby manufacturing the electrolysis electrode 100. This manufacturing method of the present embodiment can achieve high productivity of the electrolysis electrode 100. Specifically, a catalyst layer is formed on the electrolysis electrode substrate by a coating process of applying a coating liquid containing a catalyst, a drying process of drying the coating liquid, and a thermal decomposition process of thermal decomposition. Here, thermal decomposition refers to heating a metal salt as a precursor and decomposing it into a metal or metal oxide and a gaseous substance. Depending on the type of metal used, the type of salt, the atmosphere for thermal decomposition, etc., the decomposition products will be different, but in an oxidizing atmosphere, many metals have a tendency to easily form oxides. In the industrial manufacturing process of electrodes, thermal decomposition is usually carried out in air, and in most cases metal oxides or metal hydroxides are formed.

[0762] (Formation of the First Layer of the Anode)

[0763] (Coating process)

[0764] The first layer 20 is formed by applying a solution containing a metal salt of at least one of ruthenium, iridium, and titanium (a first coating solution) to the electrolytic electrode substrate and then thermally decomposing (firing) the solution in the presence of oxygen. The ruthenium, iridium, and titanium contents of the first coating solution are substantially equal to those of the first layer 20.

[0765] The metal salt may be any of chlorides, nitrates, sulfates, metal alkoxides, or other salts. The solvent for the first coating solution can be selected according to the type of metal salt, and water and alcohols such as butanol can be used. Water or a mixed solvent of water and an alcohol is preferred. The total metal concentration in the first coating solution containing the dissolved metal salt is not particularly limited; however, it is preferably in the range of 10 to 150 g / L to ensure the thickness of the coating formed by a single coating.

[0766] As a method for applying the first coating liquid to the electrolysis electrode substrate 10, a dipping method in which the electrolysis electrode substrate 10 is immersed in the first coating liquid, a method of applying the first coating liquid with a brush, a roller method using a sponge-like roller impregnated with the first coating liquid, and an electrostatic coating method in which the electrolysis electrode substrate 10 and the first coating liquid are sprayed with opposite charges are used. Among them, the roller method and the electrostatic coating method are preferred because they have excellent industrial productivity.

[0767] (Drying process, thermal decomposition process)

[0768] After applying the first coating liquid to the electrolytic electrode substrate 100, the liquid is dried at a temperature of 10 to 90°C and thermally decomposed in a firing furnace heated to 350 to 650°C. During the drying and thermal decomposition, a pre-firing process at 100 to 350°C may be performed as needed. The drying, pre-firing, and thermal decomposition temperatures can be appropriately selected based on the composition of the first coating liquid and the type of solvent. A long thermal decomposition time per cycle is preferred; from the perspective of electrode productivity, it is preferably 3 to 60 minutes, and more preferably 5 to 20 minutes.

[0769] The above-mentioned coating, drying and thermal decomposition cycles are repeated to form the coating (first layer 20) to a predetermined thickness. After forming the first layer 20, if necessary, further heating after calcining for a long time can further improve the stability of the first layer 20.

[0770] (Formation of the Second Layer)

[0771] The second layer 30 is formed as needed, for example, by applying a solution containing a palladium compound and a platinum compound or a solution containing a ruthenium compound and a titanium compound (second coating solution) onto the first layer 20 and then thermally decomposing the solution in the presence of oxygen.

[0772] (Formation of the First Layer of the Cathode by Thermal Decomposition Method)

[0773] (Coating process)

[0774] The first layer 20 is obtained by applying a solution containing various combinations of metal salts (first coating solution) onto an electrolytic electrode substrate and then thermally decomposing (firing) the solution in the presence of oxygen. The metal content in the first coating solution is substantially equal to that in the first layer 20 .

[0775] The metal salt may be any of chlorides, nitrates, sulfates, metal alkoxides, or other salts. The solvent for the first coating solution can be selected according to the type of metal salt, and water and alcohols such as butanol can be used. Water or a mixed solvent of water and an alcohol is preferred. The total metal concentration in the first coating solution containing the dissolved metal salt is not particularly limited; however, it is preferably in the range of 10 to 150 g / L to ensure the thickness of the coating formed by a single coating.

[0776] As a method for applying the first coating liquid to the electrolysis electrode substrate 10, a dipping method in which the electrolysis electrode substrate 10 is immersed in the first coating liquid, a method of applying the first coating liquid with a brush, a roller method using a sponge-like roller impregnated with the first coating liquid, and an electrostatic coating method in which the electrolysis electrode substrate 10 and the first coating liquid are sprayed with opposite charges are used. Among them, the roller method and the electrostatic coating method are preferred because they have excellent industrial productivity.

[0777] (Drying process, thermal decomposition process)

[0778] After the first coating liquid is applied to the electrolysis electrode substrate 10, it is dried at a temperature of 10 to 90°C and thermally decomposed in a firing furnace heated to 350 to 650°C. During the drying and thermal decomposition, a pre-firing process at 100 to 350°C may be performed as needed. The drying, pre-firing, and thermal decomposition temperatures can be appropriately selected based on the composition of the first coating liquid and the type of solvent. A long thermal decomposition time per cycle is preferred; from the perspective of electrode productivity, it is preferably 3 to 60 minutes, and more preferably 5 to 20 minutes.

[0779] The above-mentioned coating, drying and thermal decomposition cycles are repeated to form the coating (first layer 20) to a predetermined thickness. After forming the first layer 20, if necessary, further heating after calcining for a long time can further improve the stability of the first layer 20.

[0780] (Formation of the Intermediate Layer)

[0781] The intermediate layer is formed as needed, for example, by applying a solution containing a palladium compound or a platinum compound (second coating solution) to the substrate and then thermally decomposing it in the presence of oxygen. Alternatively, the nickel oxide intermediate layer can be formed on the substrate surface by simply heating the substrate without applying the solution.

[0782] (Formation of the First Layer of the Cathode by Ion Plating)

[0783] The first layer 20 can also be formed by ion plating.

[0784] One example involves irradiating a ruthenium metal target with electron beams while securing the substrate within a chamber. The evaporated ruthenium metal particles become positively charged in the plasma within the chamber and deposit on the negatively charged substrate. The plasma atmosphere is composed of argon and oxygen, and the ruthenium deposits on the substrate as ruthenium oxide.

[0785] (Formation of the First Layer of the Cathode by Plating)

[0786] The first layer 20 can also be formed by plating.

[0787] For example, by using the substrate as a cathode and performing electroplating in an electrolyte solution containing nickel and tin, an alloy plating layer of nickel and tin can be formed.

[0788] (Formation of the First Layer of the Cathode by Thermal Spraying)

[0789] The first layer 20 can also be formed by thermal spraying.

[0790] As an example, by plasma spraying nickel oxide particles onto a substrate, a catalyst layer composed of a mixture of metallic nickel and nickel oxide can be formed.

[0791] The electrolysis electrode of this embodiment can be used in an integrated manner with a separator such as an ion exchange membrane or a microporous membrane. Therefore, it can be used as a membrane-integrated electrode, eliminating the need to replace the cathode and anode when replacing the electrode, significantly improving operating efficiency.

[0792] Furthermore, by integrating the electrode with a separator such as an ion exchange membrane or a microporous membrane, the electrolytic performance can be made equal to or further improved than that of a new product.

[0793] Hereinafter, the ion exchange membrane will be described in detail.

[0794] [Ion exchange membrane]

[0795] The ion exchange membrane comprises: a membrane body comprising a hydrocarbon polymer or a fluorine-containing polymer having ion exchange groups; and a coating layer provided on at least one surface of the membrane body. The coating layer comprises inorganic particles and a binder, and the specific surface area of ​​the coating layer is 0.1 to 10 m 2 For the ion exchange membrane of this structure, the gas generated during electrolysis has little effect on the electrolytic performance, and can exert stable electrolytic performance.

[0796] The perfluorocarbon polymer membrane having an ion exchange group introduced therein is a membrane having an ion exchange group (-SO3 - The sulfonic acid layer having the group represented by (hereinafter also referred to as "sulfonic acid group") and the ion exchange group (-CO2 - The film of any one of the carboxylic acid layers having a group represented by (hereinafter also referred to as a "carboxylic acid group"). From the viewpoint of strength and dimensional stability, it is preferred to further have a reinforcing core material.

[0797] The inorganic particles and the binder will be described in detail below in the section describing the coating layer.

[0798] Figure 23 The ion exchange membrane 1 includes a membrane body 10 made of a hydrocarbon polymer or a fluorine-containing polymer having ion exchange groups, and coating layers 11 a and 11 b formed on both surfaces of the membrane body 10 .

[0799] In the ion exchange membrane 1, the membrane body 10 has an ion exchange group (-SO3 - The sulfonic acid layer 3 has a group represented by, hereinafter also referred to as "sulfonic acid group"), and an ion exchange group derived from a carboxyl group (-CO2 - The carboxylic acid layer 2 (hereinafter also referred to as "carboxylic acid group") is reinforced with strength and dimensional stability by the reinforcing core material 4. The ion exchange membrane 1 includes the sulfonic acid layer 3 and the carboxylic acid layer 2 and is therefore suitable for use as a cation exchange membrane.

[0800] It should be noted that the ion exchange membrane may also have only one of the sulfonic acid layer and the carboxylic acid layer. In addition, the ion exchange membrane does not necessarily need to be reinforced by the reinforcing core material, and the configuration state of the reinforcing core material is not limited to Figure 23 example.

[0801] (Membrane body)

[0802] First, the membrane body 10 constituting the ion exchange membrane 1 will be described.

[0803] The membrane body 10 has a function of selectively permeating cations and may be composed of a hydrocarbon polymer or a fluorine-containing polymer having ion exchange groups. The structure and material thereof are not particularly limited, and appropriate structures and materials may be selected as appropriate.

[0804] The hydrocarbon polymer or fluorine-containing polymer having ion-exchange groups in the membrane body 10 can be obtained, for example, from a hydrocarbon polymer or fluorine-containing polymer having an ion-exchange group precursor that can be converted into an ion-exchange group by hydrolysis or the like. Specifically, for example, a polymer having a main chain composed of a fluorinated hydrocarbon, having groups (ion-exchange group precursors) as side chains that can be converted into ion-exchange groups by hydrolysis or the like, and capable of melt processing (hereinafter referred to as "fluorine-containing polymer (a)") can be used to prepare a precursor of the membrane body 10, and then the ion-exchange group precursor can be converted into an ion-exchange group to obtain the membrane body 10.

[0805] The fluorine-containing polymer (a) can be produced, for example, by copolymerizing at least one monomer selected from the following Group 1 with at least one monomer selected from the following Group 2 and / or the following Group 3. Alternatively, the fluorine-containing polymer (a) can be produced by homopolymerizing one monomer selected from any one of the following Group 1, the following Group 2, and the following Group 3.

[0806] As monomers of the first group, for example, fluorinated vinyl compounds can be mentioned. Examples of fluorinated vinyl compounds include vinyl fluoride, tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, trifluoroethylene, chlorotrifluoroethylene, and perfluoroalkyl vinyl ether. In particular, when an ion exchange membrane is used as the membrane for alkaline electrolysis, the fluorinated vinyl compound is preferably a perfluoromonomer, preferably a perfluoromonomer selected from the group consisting of tetrafluoroethylene, hexafluoropropylene, and perfluoroalkyl vinyl ether.

[0807] As monomers of the second group, for example, vinyl compounds having a functional group that can be converted into a carboxylic acid type ion exchange group (carboxylic acid group) can be cited. As vinyl compounds having a functional group that can be converted into a carboxylic acid group, for example, CF2=CF(OCF2CYF) can be cited. s -O(CZF) t-COOR, etc. (here, s represents an integer of 0 to 2, t represents an integer of 1 to 12, Y and Z each independently represent F or CF3, and R represents a lower alkyl group. A lower alkyl group is, for example, an alkyl group having 1 to 3 carbon atoms.)

[0808] Among these, CF2=CF(OCF2CYF) is preferred. n -O(CF2) m -COOR wherein n represents an integer of 0 to 2, m represents an integer of 1 to 4, Y represents F or CF3, and R represents CH3, C2H5, or C3H7.

[0809] It should be noted that when an ion exchange membrane is used as a cation exchange membrane for alkaline electrolysis, it is preferred to use at least a perfluoro compound as a monomer. However, since the alkyl group of the ester group (refer to R above) is removed from the polymer at the time of hydrolysis, the alkyl group (R) may not be a perfluoroalkyl group in which all hydrogen atoms are replaced by fluorine atoms.

[0810] As the monomer of the second group, among the above, the monomers shown below are more preferable.

[0811] CF2=CFOCF2-CF(CF3)OCF2COOCH3,

[0812] CF2=CFOCF2CF(CF3)O(CF2)2COOCH3,

[0813] CF2=CF[OCF2-CF(CF3)]2O(CF2)2COOCH3,

[0814] CF2=CFOCF2CF(CF3)O(CF2)3COOCH3,

[0815] CF2=CFO(CF2)2COOCH3、

[0816] CF2=CFO(CF2)3COOCH3.

[0817] Examples of monomers in Group 3 include vinyl compounds having a functional group that can be converted into a sulfone-type ion exchange group (sulfonic acid group). Preferred examples of vinyl compounds having a functional group that can be converted into a sulfonic acid group include monomers represented by CF2=CFO-X-CF2-SO2F (where X represents a perfluoroalkylene group). Specific examples thereof include the following monomers.

[0818] CF2=CFOCF2CF2SO2F、

[0819] CF2=CFOCF2CF(CF3)OCF2CF2SO2F,

[0820] CF2=CFOCF2CF(CF3)OCF2CF2CF2SO2F,

[0821] CF2=CF(CF2)2SO2F,

[0822] CF2=CFO[CF2CF(CF3)O]2CF2CF2SO2F,

[0823] CF2=CFOCF2CF(CF2OCF3)OCF2CF2SO2F.

[0824] Among these, CF2=CFOCF2CF(CF3)OCF2CF2CF2SO2F and CF2=CFOCF2CF(CF3)OCF2CF2SO2F are more preferable.

[0825] Copolymers obtained from these monomers can be produced using polymerization methods developed for the homopolymerization and copolymerization of ethylene fluoride, particularly general polymerization methods used for tetrafluoroethylene. For example, in non-aqueous methods, polymerization can be carried out using an inert solvent such as a perfluorocarbon or chlorofluorocarbon in the presence of a free radical polymerization initiator such as a perfluorocarbon peroxide or an azo compound at a temperature of 0 to 200°C and a pressure of 0.1 to 20 MPa.

[0826] In the above-mentioned copolymerization, the type and ratio of the combination of the above-mentioned monomers are not particularly limited, and are selected and determined according to the type and amount of the functional groups that are desired to be imparted to the obtained fluorine-containing polymer. For example, in the case of forming a fluorine-containing polymer containing only carboxylic acid groups, at least one monomer is selected from the above-mentioned first group and second group respectively for copolymerization. In addition, in the case of forming a fluorine-containing polymer containing only sulfonic acid groups, at least one monomer is selected from the above-mentioned first group and third group respectively for copolymerization. In addition, in the case of forming a fluorine-containing polymer with carboxylic acid groups and sulfonic acid groups, at least one monomer is selected from the above-mentioned first group, second group and third group respectively for copolymerization. In this case, copolymers consisting of the above-mentioned first group and second group, and copolymers consisting of the above-mentioned first group and third group are polymerized respectively, and then mixed, thereby obtaining the target fluorine-containing polymer. In addition, the mixing ratio of each monomer is not particularly limited, and in the case of increasing the amount of functional groups per unit polymer, it is sufficient to increase the ratio of monomers selected from the above-mentioned second group and third group.

[0827] The total ion exchange capacity of the fluorinated copolymer is not particularly limited, but is preferably 0.5 to 2.0 mg equivalent / g, more preferably 0.6 to 1.5 mg equivalent / g. The total ion exchange capacity refers to the equivalent of exchange groups per unit weight of the dry resin and can be measured by neutralization titration or the like.

[0828] Ion exchange membrane 1 comprises a laminated sulfonic acid layer 3 comprising a fluorinated polymer having sulfonic acid groups and a laminated carboxylic acid layer 2 comprising a fluorinated polymer having carboxylic acid groups in membrane body 10. This layered membrane body 10 further enhances the permselectivity of cations such as sodium ions.

[0829] When the ion exchange membrane 1 is placed in an electrolytic cell, it is usually placed so that the sulfonic acid layer 3 is located on the anode side of the electrolytic cell and the carboxylic acid layer 2 is located on the cathode side of the electrolytic cell.

[0830] The sulfonic acid layer 3 is preferably made of a material with low electrical resistance and is preferably thicker than the carboxylic acid layer 2 in terms of film strength. The sulfonic acid layer 3 is preferably 2 to 25 times thicker than the carboxylic acid layer 2, more preferably 3 to 15 times thicker.

[0831] The carboxylic acid layer 2 preferably has high anion exclusion properties even when the membrane thickness is thin. The anion exclusion property referred to here refers to the property of preventing anions from entering or permeating the ion exchange membrane 1. To improve the anion exclusion property, it is effective to configure a carboxylic acid layer with a smaller ion exchange capacity than the sulfonic acid layer.

[0832] As the fluorine-containing polymer used for the sulfonic acid layer 3, for example, a polymer obtained by using CF2=CFOCF2CF(CF3)OCF2CF2SO2F as a monomer of the third group is suitable.

[0833] As the fluorine-containing polymer used for the carboxylic acid layer 2, for example, a polymer obtained by using CF2=CFOCF2CF(CF2)O(CF2)2COOCH3 as the monomer of the second group is suitable.

[0834] (Coating layer)

[0835] The ion exchange membrane has a coating layer on at least one surface of the membrane body. Figure 23 As shown, in the ion exchange membrane 1 , coating layers 11 a and 11 b are formed on both surfaces of a membrane body 10 , respectively.

[0836] The coating layer contains inorganic particles and a binder.

[0837] The average particle size of the inorganic particles is more preferably 0.90 μm or greater. When the average particle size of the inorganic particles is 0.90 μm or greater, the durability against not only gas adhesion but also impurities is greatly improved. That is, by increasing the average particle size of the inorganic particles while satisfying the above-mentioned specific surface area value, a particularly significant effect can be obtained. Due to the satisfaction of this average particle size and specific surface area, irregular inorganic particles are preferred. Inorganic particles obtained by melting or by crushing raw ore can be used. Preferably, inorganic particles obtained by crushing raw ore can be suitably used.

[0838] The average particle size of the inorganic particles may be 2 μm or less. If the average particle size of the inorganic particles is 2 μm or less, the membrane can be prevented from being damaged by the inorganic particles. The average particle size of the inorganic particles is more preferably 0.90 to 1.2 μm.

[0839] Here, the average particle size can be measured using a particle size distribution meter ("SALD2200" manufactured by Shimadzu Corporation).

[0840] The inorganic particles are preferably irregular in shape. This further improves resistance to impurities. Furthermore, the inorganic particles preferably have a wide particle size distribution.

[0841] The inorganic particles preferably contain at least one inorganic substance selected from the group consisting of oxides, nitrides, and carbides of Group IV elements of the periodic table. From the perspective of durability, zirconium oxide particles are more preferred.

[0842] The inorganic particles are preferably inorganic particles produced by pulverizing raw ore of the inorganic particles, or spherical particles having a uniform particle size obtained by melting and refining raw ore of the inorganic particles.

[0843] As the raw ore pulverization method, it is not particularly limited, and ball mill, bead mill, colloid mill, cone mill, disc mill, edge mill, pulverizing mill, hammer mill, particle mill, VSI mill, Wiley pulverizer, roller mill, jet mill etc. can be enumerated. In addition, preferably after pulverization, clean, now as cleaning method, preferably carry out acid treatment. Thus, it is possible to reduce impurities such as iron attached to the surface of the inorganic particles.

[0844] The coating layer preferably includes a binder. The binder is a component that holds the inorganic particles on the surface of the ion exchange membrane to form the coating layer. From the perspective of resistance to the electrolyte or electrolysis products, the binder preferably includes a fluorine-containing polymer.

[0845] As adhesive, from the aspect of the resistance of the product produced by the electrolyte or electrolysis and the adhesiveness on the surface of the ion exchange membrane, it is more preferably a fluorine-containing polymer with a carboxylic acid group or a sulfonic acid group. In the case where a coating layer is set on the layer (sulfonic acid layer) comprising the fluorine-containing polymer with a sulfonic acid group, as the adhesive of the coating layer, it is further preferred to use a fluorine-containing polymer with a sulfonic acid group. In addition, in the case where a coating layer is set on the layer (carboxylic acid layer) comprising the fluorine-containing polymer with a carboxylic acid group, as the adhesive of the coating layer, it is further preferred to use a fluorine-containing polymer with a carboxylic acid group.

[0846] The content of the inorganic particles in the coating layer is preferably 40 to 90% by mass, more preferably 50 to 90% by mass, and the content of the binder is preferably 10 to 60% by mass, more preferably 10 to 50% by mass.

[0847] The distribution density of the coating layer in the ion exchange membrane is preferably 2 In the case where the ion exchange membrane has a concavo-convex surface, the distribution density of the coating layer is preferably 0.05 to 2 mg per 1 cm 2 0.5 to 2 mg.

[0848] The method for forming the coating layer is not particularly limited, and a known method can be used. For example, a method in which inorganic particles are dispersed in a solution containing a binder and the resulting coating solution is applied by spraying or the like can be mentioned.

[0849] (Reinforced core material)

[0850] The ion exchange membrane preferably has a reinforcing core material disposed inside the membrane body.

[0851] The reinforcing core material enhances the strength and dimensional stability of the ion exchange membrane. By placing the reinforcing core material within the membrane body, the membrane's expansion and contraction can be controlled to a desired range. This prevents the membrane from expanding or contracting beyond necessary levels during electrolysis, maintaining excellent dimensional stability over extended periods.

[0852] The composition of the reinforcing core material is not particularly limited; for example, it can be formed by spinning a yarn called a reinforcing yarn. The reinforcing yarn herein refers to a member constituting the reinforcing core material, and refers to a yarn that can impart the desired dimensional stability and mechanical strength to the ion exchange membrane and can be stably present in the ion exchange membrane. By using a reinforcing core material spun from this reinforcing yarn, it is possible to impart even greater dimensional stability and mechanical strength to the ion exchange membrane.

[0853] The materials of the reinforcing core material and the reinforcing yarn used therein are not particularly limited, but are preferably materials resistant to acids, alkalis, etc. Since heat resistance and chemical resistance are required for a long time, fibers composed of fluorine-containing polymers are preferably used.

[0854] As the fluorine-containing polymer for strengthening the core material, for example, polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-ethylene copolymer (ETFE), tetrafluoroethylene-hexafluoropropylene copolymer, chlorotrifluoroethylene-ethylene copolymer and vinylidene fluoride polymer (PVDF) etc. can be mentioned. Among these, from the aspect of heat resistance and chemical resistance, it is particularly preferred to use the fiber consisting of polytetrafluoroethylene.

[0855] The diameter of the reinforcing yarn used to reinforce the core material is not particularly limited, but is preferably 20 to 300 denier, more preferably 50 to 250 denier. The weave density (the number of picks per unit length) is preferably 5 to 50 strands / inch. The method of reinforcing the core material is not particularly limited, and examples include woven fabrics, non-woven fabrics, and knitted fabrics, with woven fabrics being preferred. Furthermore, the thickness of the woven fabric is preferably 30 to 250 μm, more preferably 30 to 150 μm.

[0856] The woven or knitted fabric can be made of monofilament, multifilament or yarns thereof, slit yarn, etc., and can be made of various weaving methods such as plain weave, leno weave, knit, groove weave, and crepe stripe weave.

[0857] The weaving method and arrangement of the reinforcing core material in the membrane body are not particularly limited and can be appropriately arranged in consideration of the size and shape of the ion exchange membrane, the desired physical properties of the ion exchange membrane, the usage environment, and the like.

[0858] For example, a reinforcing core material can be arranged along a prescribed direction of the membrane body, but from the perspective of dimensional stability, it is preferred to arrange the reinforcing core material along a prescribed first direction, and to arrange other reinforcing core materials along a second direction roughly perpendicular to the first direction. By arranging a plurality of reinforcing core materials in a roughly straight manner inside the longitudinal membrane body of the membrane body, it is possible to impart better dimensional stability and mechanical strength in multiple directions. For example, it is preferred to weave a reinforcing core material (warp) arranged in the longitudinal direction and a reinforcing core material (weft) arranged in the transverse direction into the surface of the membrane body. From the perspective of dimensional stability, mechanical strength and ease of manufacture, it is more preferred to: make the warp and weft alternately float and sink and beat up to form a plain weave; twist two warps while weaving them into the weft; square weave woven by beating up the same number of wefts for two or more warps that are aligned and arranged; and so on.

[0859] It is particularly preferred to configure the reinforcing core material in two directions, the MD direction (Machine Direction direction, longitudinal) and the TD direction (Transverse Direction direction, transverse) of the ion exchange membrane. That is, it is preferably woven flat in the MD direction and the TD direction. Here, the MD direction refers to the direction (flow direction) in which the membrane body and various core materials (for example, reinforcing core materials, reinforcing yarns, sacrificial yarns described later) are conveyed in the manufacturing process of the ion exchange membrane described later, and the TD direction refers to the direction roughly perpendicular to the MD direction. In addition, the yarn woven along the MD direction is called MD yarn, and the yarn woven along the TD direction is called TD yarn. Typically, the ion exchange membranes used for electrolysis are mostly rectangular, with the length direction being the MD direction and the width direction being the TD direction. By weaving in a reinforcing core material as an MD yarn and a reinforcing core material as a TD yarn, it is possible to impart more excellent dimensional stability and mechanical strength in multiple directions.

[0860] The arrangement interval of the reinforcing core members is not particularly limited, and they can be appropriately arranged in consideration of the desired physical properties of the ion exchange membrane, the usage environment, and the like.

[0861] The opening ratio of the reinforcing core material is not particularly limited, but is preferably 30% or more, more preferably 50% or more and 90% or less. Regarding the opening ratio, it is preferably 30% or more from the perspective of the electrochemical properties of the ion exchange membrane, and preferably 90% or less from the perspective of the mechanical strength of the ion exchange membrane.

[0862] The opening ratio of the reinforcing core material is the ratio (B / A) of the total surface area (B) through which substances such as ions (electrolyte and cations contained therein (e.g., sodium ions)) can pass, relative to the area (A) of any one surface of the membrane body. The total surface area (B) through which substances such as ions can pass is the total area of ​​the region of the ion exchange membrane where cations, electrolyte, etc. are not blocked by the reinforcing core material contained in the ion exchange membrane.

[0863] Figure 24 This is a schematic diagram for explaining the aperture ratio of the reinforcing core material constituting the ion exchange membrane. Figure 24 A portion of the ion exchange membrane is enlarged to illustrate only the arrangement of the reinforcing core materials 21 and 22 in this region, with other components omitted from illustration.

[0864] The total area (B) of the area (A) through which substances such as ions can pass can be calculated by subtracting the total area (C) of the reinforcing core material from the area (A) of the region (the region surrounded by the longitudinally arranged reinforcing core material 21 and the transversely arranged reinforcing core material 22, where the area (A) includes the area of ​​the reinforcing core material. That is, the aperture ratio can be calculated using the following formula (I).

[0865] Opening ratio=(B) / (A)=((A)-(C)) / (A)…(I)

[0866] Among reinforcing core materials, flat yarns or highly oriented monofilaments containing PTFE are particularly preferred from the perspectives of chemical resistance and heat resistance. Specifically, a flat yarn obtained by cutting a high-strength porous sheet made of PTFE into a tape-shaped shape is more preferred, or a reinforcing core material using highly oriented monofilaments made of PTFE, with a plain weave of 50 to 300 denier, a weave density of 10 to 50 strands / inch, and a thickness of 50 to 100 μm is more preferred. The aperture ratio of the ion exchange membrane containing this reinforcing core material is more preferably 60% or greater.

[0867] Examples of the shape of the reinforcing yarn include round yarns and ribbon-shaped yarns.

[0868] (Connecting hole)

[0869] The ion exchange membrane preferably has continuous pores inside the membrane body.

[0870] Connecting pores are holes that serve as channels for the ions and electrolyte generated during electrolysis. Furthermore, connecting pores are tubular holes formed within the membrane body, created by the dissolution of the sacrificial core material (or sacrificial wire) described below. The shape and diameter of the connecting pores can be controlled by selecting the shape and diameter of the sacrificial core material (or sacrificial wire).

[0871] The formation of the through holes in the ion exchange membrane ensures the mobility of the electrolyte during electrolysis. The shape of the through holes is not particularly limited and can be adapted to the shape of the sacrificial core material used to form the through holes according to the production method described below.

[0872] The interconnecting holes are preferably formed so as to alternately pass through the anode side (sulfonic acid layer side) and cathode side (carboxylic acid layer side) of the reinforcing core material. This structure allows ions (e.g., sodium ions) transported through the electrolyte filling the interconnecting holes on the cathode side of the reinforcing core material to flow toward the cathode side of the reinforcing core material. As a result, the flow of cations is not hindered, further reducing the resistance of the ion exchange membrane.

[0873] The communicating pores may be formed in only one predetermined direction of the membrane body constituting the ion exchange membrane, but are preferably formed in both the longitudinal and lateral directions of the membrane body in order to exhibit more stable electrolytic performance.

[0874] [Manufacturing method]

[0875] As a preferred method for producing an ion exchange membrane, there can be mentioned a method comprising the following steps (1) to (6).

[0876] (1) Step: A step of producing a fluorine-containing polymer having an ion-exchange group or an ion-exchange group precursor capable of becoming an ion-exchange group by hydrolysis.

[0877] (2) Step: A step of weaving at least a plurality of reinforcing core materials and sacrificial filaments soluble in acid or alkali and forming continuous pores as needed to obtain a reinforcing material having sacrificial filaments arranged between adjacent reinforcing core materials.

[0878] (3) Step: a step of forming a membrane from the fluorine-containing polymer having an ion-exchange group or an ion-exchange group precursor capable of becoming an ion-exchange group by hydrolysis.

[0879] (4) Step: A step of embedding the reinforcing material in the membrane as needed to obtain a membrane body having the reinforcing material disposed therein.

[0880] Step (5): A step of hydrolyzing the membrane body obtained in step (4) (hydrolysis step).

[0881] Step (6): A step of providing a coating layer on the film body obtained in step (5) (coating step).

[0882] Hereinafter, each step will be described in detail.

[0883] (1) Process: Process for producing fluorine-containing polymers

[0884] In step (1), a fluorine-containing polymer is produced using the raw material monomers described in Groups 1 to 3. To control the ion exchange capacity of the fluorine-containing polymer, the mixing ratio of the raw material monomers can be adjusted during the production of the fluorine-containing polymer forming each layer.

[0885] (2) Process: Manufacturing process of reinforcement materials

[0886] The reinforcing material refers to a woven fabric, etc., made from reinforcing yarns. By embedding the reinforcing material within the membrane, a reinforcing core material is formed. When an ion exchange membrane having interconnecting pores is formed, sacrificial yarns are also woven into the reinforcing material. The sacrificial yarns preferably comprise 10-80% by mass of the overall reinforcing material, more preferably 30-70% by mass. Weaving in sacrificial yarns can also prevent the reinforcing core material from misaligning.

[0887] The sacrificial yarn is soluble in the membrane manufacturing process or electrolysis environment, and rayon, polyethylene terephthalate (PET), cellulose, polyamide, etc. are used. In addition, polyvinyl alcohol having a thickness of 20 to 50 denier and composed of monofilaments or multifilaments is also preferred.

[0888] It should be noted that in step (2), by adjusting the arrangement of the reinforcing core material and the sacrificial wire, the opening ratio, the arrangement of the communicating holes, etc. can be controlled.

[0889] (3) Process: Membrane process

[0890] In step (3), the fluorine-containing polymer obtained in step (1) is formed into a film using an extruder. The film may have a single-layer structure, a two-layer structure of a sulfonic acid layer and a carboxylic acid layer as described above, or a multilayer structure of three or more layers.

[0891] As a method of forming a membrane, for example, the following method can be mentioned.

[0892] A method in which a fluorinated polymer having a carboxylic acid group and a fluorinated polymer having a sulfonic acid group are separately formed into membranes.

[0893] A method of preparing a composite film by coextruding a fluorinated polymer having a carboxylic acid group and a fluorinated polymer having a sulfonic acid group.

[0894] It should be noted that the films may be two or more. In addition, co-extrusion of different types of films is preferred because it helps to improve the bonding strength of the interface.

[0895] (4) Process: Process of obtaining the membrane body

[0896] In step (4), the reinforcing material obtained in step (2) is embedded in the interior of the membrane obtained in step (3), thereby obtaining a membrane body having the reinforcing material therein.

[0897] As a preferred method for forming the membrane body, there are the following: (i) a fluorine-containing polymer having a carboxylic acid precursor (for example, a carboxylate functional group) located on the cathode side (the layer composed of which is hereinafter referred to as the first layer) and a fluorine-containing polymer having a sulfonic acid precursor (for example, a sulfonyl fluoride functional group) (the layer composed of which is hereinafter referred to as the second layer) are formed into a membrane by co-extrusion, and a heating source and a vacuum source are used as needed to stack them in the order of reinforcing material, second layer / first layer composite membrane on a flat plate or cylinder having a large number of pores on the surface, separated by air-permeable heat-resistant release paper, and each polymer is laminated in the order of reinforcing material, second layer / first layer composite membrane, and a heating source and a vacuum source are used as needed to laminate them in the order of reinforcing material, second layer / first layer composite membrane, and a heating source and a vacuum source are used ... (ii) a method in which the air between the layers is removed by reducing pressure at a temperature at which the composite film is melted and the layers are integrated at the same time; (iii) a method in which a fluorine-containing polymer having a sulfonic acid group precursor (third layer) is separately formed into a film in advance in a separate operation from the second layer / first layer composite film, a heating source and a vacuum source are used as needed, and a third layer of film, a reinforcing core material, and a composite film consisting of the second layer / first layer are layered in this order on a flat plate or cylinder having a large number of pores on the surface, with air-permeable heat-resistant release paper interposed therebetween, and the air between the layers is removed by reducing pressure at a temperature at which the polymers are melted and the layers are integrated at the same time.

[0898] Here, coextrusion of the first layer and the second layer helps to improve the bonding strength at the interface.

[0899] In addition, compared with the pressurized pressing method, the integration method under reduced pressure has the characteristic of increasing the thickness of the third layer on the reinforcing material. In addition, since the reinforcing material is fixed to the inner surface of the membrane body, it has the performance of fully maintaining the mechanical strength of the ion exchange membrane.

[0900] It should be noted that the lamination transformation described here is an example, and a suitable lamination pattern (for example, combination of layers, etc.) may be appropriately selected in consideration of the desired layer composition or physical properties of the film body, and then co-extrusion may be performed.

[0901] It should be noted that in order to further improve the electrical performance of the ion exchange membrane, a fourth layer composed of a fluorine-containing polymer having both a carboxylic acid precursor and a sulfonic acid precursor can be further sandwiched between the first layer and the second layer, or a fourth layer composed of a fluorine-containing polymer having both a carboxylic acid precursor and a sulfonic acid precursor can be used instead of the second layer.

[0902] The fourth layer may be formed by separately preparing a fluorine-containing polymer having a carboxylic acid group precursor and a fluorine-containing polymer having a sulfonic acid group precursor and then mixing them, or by using a copolymer of a monomer having a carboxylic acid group precursor and a monomer having a sulfonic acid group precursor.

[0903] When the fourth layer is composed of an ion exchange membrane, the first and fourth layers can be formed into a co-extruded film, and the third and second layers can be formed into films separately from them, and then stacked using the above method; or the first layer / fourth layer / second layer can be formed into films by co-extrusion at one time.

[0904] In this case, the direction in which the extruded film flows is the MD direction. In this way, a membrane body including a fluorine-containing polymer having ion exchange groups can be formed on the reinforcing material.

[0905] In addition, the ion exchange membrane preferably has a prominent part, i.e., a convex portion, consisting of a fluoropolymer with a sulfonic acid group on the surface side consisting of a sulfonic acid layer. As the method for forming this convex portion, there is no particular limitation, and the known method of forming a convex portion on the resin surface can be adopted. Specifically, for example, the method of embossing the surface of the membrane body can be cited. For example, when the above-mentioned composite membrane and reinforcing material etc. are integrated, the above-mentioned convex portion can be formed by using a release paper that has been embossed in advance. When forming a convex portion by embossing, the control of the height and configuration density of the convex portion can be carried out by controlling the embossed shape (shape of the release paper) that is transferred.

[0906] (5) Hydrolysis process

[0907] In step (5), the membrane body obtained in step (4) is hydrolyzed to convert the ion exchange group precursor into an ion exchange group (hydrolysis step).

[0908] In addition, in step (5), the sacrificial filaments contained in the membrane body can be dissolved and removed with an acid or alkali, thereby forming dissolution pores in the membrane body. It should be noted that the sacrificial filaments may remain in the connecting pores and not be completely dissolved and removed. In addition, the sacrificial filaments remaining in the connecting pores can be dissolved and removed by the electrolyte when the ion exchange membrane is subjected to electrolysis.

[0909] The sacrificial wire is soluble in acid or alkali during the manufacturing process of the ion exchange membrane and in an electrolytic environment, and the sacrificial wire is dissolved to form a continuous pore at that location.

[0910] The step (5) can be performed by immersing the membrane body obtained in the step (4) in a hydrolysis solution containing an acid or an alkali. As the hydrolysis solution, for example, a mixed solution containing KOH and DMSO (dimethyl sulfoxide) can be used.

[0911] The mixed solution preferably contains 2.5 to 4.0 N KOH and 25 to 35 mass % DMSO.

[0912] The hydrolysis temperature is preferably 70 to 100°C. The higher the temperature, the greater the apparent thickness. 75 to 100°C is more preferred.

[0913] The hydrolysis time is preferably 10 to 120 minutes. A longer time increases the apparent thickness. A more preferred time is 20 to 120 minutes.

[0914] Here, the step of dissolving the sacrificial filaments to form the communicating holes will be described in more detail. Figure 25 (a) and (b) are schematic diagrams for explaining a method of forming continuous pores in an ion exchange membrane.

[0915] exist Figure 25 In (a) and (b), only the reinforcing wire 52, the sacrificial wire 504a, and the communicating hole 504 formed by the sacrificial wire 504a are shown, and other members such as the membrane body are omitted from the illustration.

[0916] First, the reinforcing material is made by weaving in the reinforcing filaments 52 that form the reinforcing core material in the ion exchange membrane and the sacrificial filaments 504a that form the communicating pores 504 in the ion exchange membrane. Furthermore, the communicating pores 504 are formed by dissolving the sacrificial filaments 504a in step (5).

[0917] According to the above method, the weaving method of the reinforcing yarns 52 and the sacrificial yarns 504a can be adjusted according to the arrangement of the reinforcing core material and the communication holes in the membrane body of the ion exchange membrane, which is very convenient.

[0918] exist Figure 25 In (a), a plain-woven reinforcing material is shown in which reinforcing yarns 52 and sacrificial yarns 504a are woven in both the longitudinal and transverse directions of the paper. However, the arrangement of the reinforcing yarns 52 and sacrificial yarns 504a in the reinforcing material can be changed as needed.

[0919] (6) Coating process

[0920] In step (6), a coating liquid containing inorganic particles obtained by crushing or melting raw ore and a binder is prepared, and the coating liquid is applied to the surface of the ion exchange membrane obtained in step (5) and dried to form a coating layer.

[0921] As the binder, a binder obtained by hydrolyzing a fluorine-containing polymer having an ion exchange group precursor with an aqueous solution containing dimethyl sulfoxide (DMSO) and potassium hydroxide (KOH) and then immersing the polymer in hydrochloric acid to replace the counter ions of the ion exchange group with H + (For example, a fluorine-containing polymer having a carboxyl group or a sulfonic group.) This is preferred because it is easily soluble in water or ethanol described later.

[0922] The binder is dissolved in a solution of water and ethanol. The preferred volume ratio of water to ethanol is 10:1 to 1:10, more preferably 5:1 to 1:5, and even more preferably 2:1 to 1:2. Inorganic particles are dispersed in the resulting solution using a ball mill to form a coating solution. The average particle size of the particles can be adjusted by adjusting the dispersion time and rotation speed. The preferred blending amounts of the inorganic particles and binder are as described above.

[0923] The concentrations of the inorganic particles and the binder in the coating solution are not particularly limited, but a dilute coating solution is preferred so that the surface of the ion exchange membrane can be uniformly coated.

[0924] In addition, when dispersing the inorganic particles, a surfactant can be added to the dispersion. As the surfactant, a nonionic surfactant is preferred, for example, HS-210, NS-210, P-210, E-212 manufactured by NOF Corporation can be mentioned.

[0925] The obtained coating liquid is applied to the surface of the ion exchange membrane by spray coating or roll coating to obtain an ion exchange membrane.

[0926] [Microporous membrane]

[0927] As described above, the microporous membrane of the present embodiment is not particularly limited as long as it can form a laminate with the electrolysis electrode, and various microporous membranes can be applied.

[0928] The porosity of the microporous membrane of the present embodiment is not particularly limited, and may be, for example, 20 to 90, and preferably 30 to 85. The porosity can be calculated, for example, by the following formula.

[0929] Porosity = (1 - (weight of the membrane in a dry state) / (weight calculated from the volume calculated from the thickness, width, and length of the membrane and the density of the membrane material)) × 100

[0930] The average pore diameter of the microporous membrane of this embodiment is not particularly limited, but may be, for example, 0.01 μm to 10 μm, preferably 0.05 μm to 5 μm. The average pore diameter can be determined by, for example, cutting the membrane perpendicularly to the thickness direction and observing the cross section using FE-SEM. The diameter of the observed pores is measured at approximately 100 points and the average is calculated.

[0931] The thickness of the microporous membrane of the present embodiment is not particularly limited, and may be, for example, 10 μm to 1000 μm, preferably 50 μm to 600 μm. The thickness can be measured using, for example, a micrometer (manufactured by Mitutoyo Co., Ltd.).

[0932] Specific examples of the microporous membrane include Zirfon Perl UTP 500 manufactured by Agfa (also referred to as Zirfon membrane in this embodiment), and microporous membranes described in International Publication No. 2013-183584 and International Publication No. 2016-203701.

[0933] The reason why the laminated body of the present embodiment and the diaphragm shows excellent electrolytic performance is inferred as follows. When the diaphragm and the electrode are firmly bonded by methods such as thermocompression bonding as in the prior art, the electrode becomes trapped in the diaphragm and is physically bonded. The bonding portion hinders the intramembrane movement of sodium ions, and the voltage rises significantly. On the other hand, by contacting the electrode for electrolysis with the diaphragm or the power supply with appropriate bonding force as in the present embodiment, the situation of hindering the intramembrane movement of sodium ions that has become a problem in the prior art disappears. Thus, when the diaphragm or the power supply contacts the electrode for electrolysis with appropriate bonding force, although the diaphragm or the power supply and the electrode for electrolysis become one body, it is possible to show excellent electrolytic performance.

[0934] [Wound body]

[0935] The wound body of this embodiment includes the laminate of this embodiment. That is, the wound body of this embodiment is formed by winding the laminate of this embodiment. By winding the laminate of this embodiment and reducing its size, as in the wound body of this embodiment, it is possible to further improve handling.

[0936] [Electrolyzer]

[0937] The electrolytic cell of this embodiment includes the laminate of this embodiment. Hereinafter, an embodiment of the electrolytic cell will be described in detail, taking the case of performing salt electrolysis using an ion exchange membrane as a diaphragm as an example.

[0938] [Electrolysis unit]

[0939] Figure 26 is a cross-sectional view of the electrolysis unit 1.

[0940] The electrolytic unit 1 includes an anode chamber 10, a cathode chamber 20, a partition wall 30 provided between the anode chamber 10 and the cathode chamber 20, an anode 11 provided in the anode chamber 10, and a cathode 21 provided in the cathode chamber 20. If necessary, a reverse current absorber 18 provided in the cathode chamber may also be provided, and the reverse current absorber 18 has a substrate 18a and a reverse current absorption layer 18b formed on the substrate 18a. The anode 11 and the cathode 21 belonging to one electrolytic unit 1 are electrically connected to each other. In other words, the electrolytic unit 1 includes the following cathode structure. The cathode structure 40 includes a cathode chamber 20, a cathode 21 provided in the cathode chamber 20, and a reverse current absorber 18 provided in the cathode chamber 20, and the reverse current absorber 18 is as follows: Figure 30As shown, it has a substrate 18a and a reverse current absorption layer 18b formed on the substrate 18a, and the cathode 21 and the reverse current absorption layer 18b are electrically connected. The cathode chamber 20 further has a current collector 23, a support 24 that supports the current collector, and a metal elastic body 22. The metal elastic body 22 is arranged between the current collector 23 and the cathode 21. The support 24 is arranged between the current collector 23 and the partition wall 30. The current collector 23 is electrically connected to the cathode 21 via the metal elastic body 22. The partition wall 30 is electrically connected to the current collector 23 via the support 24. Therefore, the partition wall 30, the support 24, the current collector 23, the metal elastic body 22 and the cathode 21 are electrically connected. The cathode 21 and the reverse current absorption layer 18b are electrically connected. The cathode 21 and the reverse current absorption layer can be directly connected or indirectly connected via the current collector, the support, the metal elastic body or the partition wall. The entire surface of the cathode 21 is preferably covered with a catalyst layer used for the reduction reaction. Alternatively, the electrical connection may be achieved by directly attaching the partition wall 30 to the support 24, directly attaching the support 24 to the current collector 23, or directly attaching the current collector 23 to the metal elastic body 22, with the cathode 21 stacked on the metal elastic body 22. Examples of methods for directly attaching these components include welding. Alternatively, the reverse current absorber 18, cathode 21, and current collector 23 may be collectively referred to as the cathode structure 40.

[0941] Figure 27 It is a cross-sectional view of two adjacent electrolytic units 1 in the electrolytic cell 4 . Figure 28 An electrolysis cell 4 is shown. Figure 29 FIG4 shows the process of assembling the electrolytic cell 4. Figure 27 As shown, the electrolysis unit 1, the cation exchange membrane 2, and the electrolysis unit 1 are arranged in series. The ion exchange membrane 2 is arranged between the anode chamber of one electrolysis unit 1 and the cathode chamber of the other electrolysis unit 1 in the two adjacent electrolysis units in the electrolytic cell. That is, the anode chamber 10 of the electrolysis unit 1 and the cathode chamber 20 of the adjacent electrolysis unit 1 are separated by the cation exchange membrane 2. Figure 28 As shown, the electrolytic cell 4 is composed of a plurality of electrolytic units 1 connected in series via an ion exchange membrane 2. That is, the electrolytic cell 4 is a bipolar electrolytic cell having a plurality of electrolytic units 1 arranged in series and an ion exchange membrane 2 arranged between adjacent electrolytic units 1. Figure 29 As shown, the electrolytic cell 4 is assembled by arranging a plurality of electrolytic cells 1 in series with an ion exchange membrane 2 interposed therebetween and connecting them with a pressurizer 5 .

[0942] The electrolytic cell 4 has an anode terminal 7 and a cathode terminal 6 connected to a power source. The anode 11 of the electrolytic cell 1 located at the end of the plurality of electrolytic cells 1 connected in series in the electrolytic cell 4 is electrically connected to the anode terminal 7. The cathode 21 of the electrolytic cell located at the end opposite to the anode terminal 7 of the plurality of electrolytic cells 2 connected in series in the electrolytic cell 4 is electrically connected to the cathode terminal 6. During electrolysis, the current flows from the anode terminal 7 side through the anode and cathode of each electrolytic cell 1 to the cathode terminal 6. It should be noted that an electrolytic cell having only an anode chamber (anode terminal cell) and an electrolytic cell having only a cathode chamber (cathode terminal cell) can also be configured at both ends of the connected electrolytic cells 1. In this case, the anode terminal 7 is connected to the anode terminal cell configured at one end, and the cathode terminal 6 is connected to the cathode terminal cell configured at the other end.

[0943] When electrolysis of brine is performed, brine is supplied to each anode chamber 10, and pure water or a low-concentration sodium hydroxide aqueous solution is supplied to the cathode chamber 20. Each liquid is supplied to each electrolysis unit 1 from an electrolyte supply pipe (omitted in the figure) via an electrolyte supply hose (omitted in the figure). In addition, the electrolyte and the products produced by electrolysis are recovered by an electrolyte recovery pipe (omitted in the figure). During electrolysis, sodium ions in the brine move from the anode chamber 10 of one electrolysis unit 1 to the cathode chamber 20 of the adjacent electrolysis unit 1 via the ion exchange membrane 2. As a result, the current in the electrolysis flows in the direction in which the electrolysis units 1 are connected in series. That is, the current flows from the anode chamber 10 to the cathode chamber 20 via the cation exchange membrane 2. As the brine is electrolyzed, chlorine gas is generated on the anode 11 side, and sodium hydroxide (solute) and hydrogen gas are generated on the cathode 21 side.

[0944] (Anode chamber)

[0945] The anode chamber 10 includes an anode 11 or an anode power supply 11. When the electrode for electrolysis of this embodiment is inserted into the anode side, 11 functions as an anode power supply. When the electrode for electrolysis of this embodiment is not inserted into the anode side, 11 functions as an anode. In addition, the anode chamber 10 preferably includes: an anode-side electrolyte supply unit for supplying electrolyte to the anode chamber 10; a baffle disposed above the anode-side electrolyte supply unit and disposed approximately parallel to or obliquely to the partition wall 30; and an anode-side gas-liquid separator disposed above the baffle for separating gas from the electrolyte mixed with gas.

[0946] (anode)

[0947] When the electrolysis electrode of this embodiment is not inserted into the anode side, an anode 11 is provided in the frame of the anode chamber 10. A metal electrode such as DSA (registered trademark) can be used as the anode 11. DSA is an electrode having a titanium base material whose surface is coated with oxides containing ruthenium, iridium, and titanium as components.

[0948] As the shape, any of punched metal, nonwoven fabric, foamed metal, expanded metal, porous metal foil formed by electroforming, and so-called woven mesh produced by weaving metal wires can be used.

[0949] (Anode power supply)

[0950] When the electrolysis electrode of this embodiment is inserted into the anode side, an anode power supply 11 is provided within the frame of the anode chamber 10. As the anode power supply 11, a metal electrode such as so-called DSA (registered trademark) can be used, or titanium that is not coated with a catalyst can be used. Alternatively, DSA with a reduced catalyst coating thickness can be used. Furthermore, a used anode can also be used.

[0951] As the shape, any of punched metal, nonwoven fabric, foamed metal, expanded metal, porous metal foil formed by electroforming, and so-called woven mesh produced by weaving metal wires can be used.

[0952] (Anode side electrolyte supply unit)

[0953] The anode side electrolyte supply unit supplies electrolyte to the anode chamber 10, and is connected to the electrolyte supply pipe. The anode side electrolyte supply unit is preferably arranged below the anode chamber 10. As the anode side electrolyte supply unit, for example, a tube (dispersion pipe) having an opening formed on the surface can be used. The tube is more preferably arranged parallel to the bottom 19 of the electrolysis unit along the surface of the anode 11. The tube is connected to the electrolyte supply tube (liquid supply nozzle) that supplies electrolyte to the electrolysis unit 1. The electrolyte supplied by the liquid supply nozzle is conveyed to the electrolysis unit 1 through the tube, and is supplied to the inside of the anode chamber 10 from the opening provided on the surface of the tube. It is preferred that the tube is arranged parallel to the bottom 19 of the electrolysis unit along the surface of the anode 11, so that the electrolyte can be uniformly supplied to the inside of the anode chamber 10.

[0954] (Anode side gas-liquid separation section)

[0955] The anode side gas-liquid separator is preferably arranged above the baffle. In electrolysis, the anode side gas-liquid separator has the function of separating the generated gas such as chlorine and the electrolyte. It should be noted that, unless otherwise stated, the above refers to Figure 26 The upward direction of the electrolytic unit 1, the downward direction is Figure 26 The electrolysis unit 1 is in a downward direction.

[0956] During electrolysis, if the generated gas and electrolyte produced in the electrolysis unit 1 become a mixed phase (gas-liquid mixed phase) and are discharged outside the system, vibration will occur due to the pressure fluctuation inside the electrolysis unit 1, sometimes causing physical damage to the ion exchange membrane. In order to suppress this phenomenon, the electrolysis unit 1 of the present embodiment is preferably provided with an anode side gas-liquid separation unit for separating gas and liquid. A defoaming plate for eliminating bubbles is preferably provided in the anode side gas-liquid separation unit. When the gas-liquid mixed phase flow passes through the defoaming plate, the bubbles burst, thereby being able to separate into electrolyte and gas. As a result, vibration during electrolysis can be prevented.

[0957] (Baffle)

[0958] The baffle is preferably arranged above the electrolyte supply portion on the anode side and is arranged approximately parallel to or obliquely to the partition wall 30. The baffle is a partition that controls the flow of the electrolyte in the anode chamber 10. By providing the baffle, the electrolyte (brine, etc.) can be internally circulated in the anode chamber 10 to make its concentration uniform. In order to produce internal circulation, the baffle is preferably arranged in a manner that separates the space near the anode 11 and the space near the partition wall 30. From this aspect, the baffle is preferably arranged to face the surfaces of the anode 11 and the partition wall 30. In the space near the anode separated by the baffle, as electrolysis proceeds, the electrolyte concentration (brine concentration) decreases, and chlorine and other generated gases are generated. As a result, a difference in specific gravity between gas and liquid is generated in the space near the anode 11 separated by the baffle and the space near the partition wall 30. By utilizing this specific gravity difference, the internal circulation of the electrolyte in the anode chamber 10 can be promoted, making the concentration distribution of the electrolyte in the anode chamber 10 more uniform.

[0959] It should be noted that although not shown Figure 26 , but a current collector may be separately provided inside the anode chamber 10. As the current collector, it may be made of the same material or structure as the current collector of the cathode chamber described later. In addition, in the anode chamber 10, the anode 11 itself may function as a current collector.

[0960] (Separation Wall)

[0961] The partition wall 30 is disposed between the anode chamber 10 and the cathode chamber 20. The partition wall 30 is sometimes referred to as a separator plate, and divides the anode chamber 10 from the cathode chamber 20. As the partition wall 30, a material known as a separator plate for electrolysis can be used, and for example, a partition wall having a nickel plate welded to the cathode side and a titanium plate welded to the anode side can be used.

[0962] (Cathode chamber)

[0963] Regarding the cathode chamber 20, when the electrolysis electrode of the present embodiment is inserted into the cathode side, 21 functions as a cathode power supply. When the electrolysis electrode of the present embodiment is not inserted into the cathode side, 21 functions as a cathode. In the case of having a reverse current absorber, the cathode or cathode power supply 21 is electrically connected to the reverse current absorber. In addition, the cathode chamber 20 also preferably has a cathode side electrolyte supply unit and a cathode side gas-liquid separation unit, similarly to the anode chamber 10. It should be noted that, among the various parts constituting the cathode chamber 20, the description is omitted for the parts that are the same as those constituting the anode chamber 10.

[0964] (cathode)

[0965] When the electrolysis electrode of the present embodiment is not inserted into the cathode side, a cathode 21 is provided in the frame of the cathode chamber 20. The cathode 21 preferably has a nickel substrate and a catalyst layer coated with the nickel substrate. As the components of the catalyst layer on the nickel substrate, metals such as Ru, C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Rh, Pd, Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and oxides or hydroxides of the metals can be enumerated. As the formation method of the catalyst layer, plating, alloy plating, dispersion composite plating, CVD, PVD, thermal decomposition and spraying can be enumerated. These methods can also be combined. The catalyst layer may have multiple layers and multiple elements as needed. In addition, the cathode 21 may be subjected to a reduction treatment as needed. It should be noted that, as the substrate of the cathode 21, nickel, a nickel alloy, or a substrate obtained by plating nickel on iron or stainless steel may also be used.

[0966] As the shape, any of punched metal, nonwoven fabric, foamed metal, expanded metal, porous metal foil formed by electroforming, and so-called woven mesh produced by weaving metal wires can be used.

[0967] (Cathode current supply)

[0968] When the electrolysis electrode of the present embodiment is inserted into the cathode side, a cathode current supply body 21 is provided in the frame of the cathode chamber 20. The cathode current supply body 21 can be coated with a catalyst component. The catalyst component can be a substance that was originally used as a cathode and remains. As the component of the catalyst layer, metals such as Ru, C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Rh, Pd, Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and oxides or hydroxides of the metals can be cited. As the formation method of the catalyst layer, plating, alloy plating, dispersion composite plating, CVD, PVD, thermal decomposition and spraying can be cited. These methods can also be combined. The catalyst layer may have multiple layers or multiple elements as needed. Alternatively, nickel, a nickel alloy, or a material obtained by plating nickel on iron or stainless steel without a catalyst coating may be used. It should be noted that nickel, a nickel alloy, or a material obtained by plating nickel on iron or stainless steel may also be used as the substrate for the cathode current source 21.

[0969] As the shape, any of punched metal, nonwoven fabric, foamed metal, expanded metal, porous metal foil formed by electroforming, and so-called woven mesh produced by weaving metal wires can be used.

[0970] (Reverse current absorption layer)

[0971] As the material of the reverse current absorption layer, a material having a redox potential lower than that of the element used in the cathode catalyst layer can be selected, for example, nickel, iron, etc.

[0972] (Current Collector)

[0973] The cathode chamber 20 preferably includes a current collector 23 . This improves the current collection effect. In this embodiment, the current collector 23 is preferably a porous plate and is arranged substantially parallel to the surface of the cathode 21 .

[0974] The current collector 23 is preferably made of a conductive metal such as nickel, iron, copper, silver, or titanium. The current collector 23 may also be a mixture, alloy, or composite oxide of these metals. It should be noted that the shape of the current collector 23 can be any shape as long as it functions as a current collector, and may be a plate or mesh.

[0975] (Metal Elastomer)

[0976] By providing the metal elastic body 22 between the current collector 23 and the cathode 21, each cathode 21 of the plurality of electrolytic cells 1 connected in series is pressed against the ion exchange membrane 2, shortening the distance between each anode 11 and each cathode 21. This reduces the voltage applied to the plurality of electrolytic cells 1 connected in series as a whole. This reduction in voltage can reduce power consumption. Furthermore, by providing the metal elastic body 22, when the laminate including the electrolytic electrode of this embodiment is placed in the electrolytic cell, the pressing pressure generated by the metal elastic body 22 can stably maintain the electrolytic electrode in a fixed position.

[0977] As the metal elastic body 22, a spring member such as a coil or a coil, a cushioning pad, etc. can be used. As the metal elastic body 22, a suitable metal elastic body can be appropriately adopted in consideration of the stress of pressing the ion exchange membrane, etc. The metal elastic body 22 can be arranged on the surface of the collector 23 on the cathode chamber 20 side, or on the surface of the partition wall on the anode chamber 10 side. Usually, the two chambers are divided in such a way that the cathode chamber 20 is smaller than the anode chamber 10. Therefore, from the perspective of the strength of the frame, it is preferred that the metal elastic body 22 is arranged between the collector 23 of the cathode chamber 20 and the cathode 21. In addition, the metal elastic body 23 is preferably composed of a conductive metal such as nickel, iron, copper, silver, or titanium.

[0978] (Support)

[0979] The cathode chamber 20 preferably includes a support 24 that electrically connects the current collector 23 and the partition wall 30. This allows efficient flow of current.

[0980] The support 24 is preferably made of a conductive metal such as nickel, iron, copper, silver, or titanium. The support 24 may be in any shape as long as it can support the current collector 23, and may be in the form of a rod, a plate, or a mesh. For example, the support 24 is in the form of a plate. A plurality of supports 24 are positioned between the separator 30 and the current collector 23. The plurality of supports 24 are arranged so that their surfaces are parallel to one another. The supports 24 are positioned approximately perpendicular to the separator 30 and the current collector 23.

[0981] (Anode side gasket, cathode side gasket)

[0982] The anode side gasket is preferably arranged on the surface of the frame constituting the anode chamber 10. The cathode side gasket is preferably arranged on the surface of the frame constituting the cathode chamber 20. The electrolysis units are connected to each other in such a manner that the anode side gasket of one electrolysis unit and the cathode side gasket of the adjacent electrolysis unit sandwich the ion exchange membrane 2 (see Figure 26 、 27 ) These gaskets can provide airtightness to the connection points when a plurality of electrolytic cells 1 are connected in series via the ion exchange membrane 2 .

[0983] A gasket refers to a component that seals between an ion exchange membrane and an electrolytic cell. As a specific example of a gasket, a picture frame-shaped rubber sheet with an opening in the center can be cited. The gasket is required to be resistant to corrosive electrolytes or generated gases and to be able to be used for a long time. Therefore, from the perspective of chemical resistance and hardness, vulcanized products or peroxide cross-linked products of ethylene propylene diene monomer (EPDM rubber) and ethylene propylene diene monomer (EPM rubber) are usually used as gaskets. In addition, as needed, a gasket coated with a fluorine-based resin such as polytetrafluoroethylene (PTFE) or tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) in the area in contact with the liquid (liquid contact portion) can also be used. As long as these gaskets have openings so as not to hinder the flow of the electrolyte, their shapes are not particularly limited. For example, a picture frame-shaped gasket is attached to the periphery of each opening of the anode chamber frame constituting the anode chamber 10 or the cathode chamber frame constituting the cathode chamber 20 using an adhesive. For example, when two electrolytic cells 1 are connected via an ion exchange membrane 2 (see Figure 27 ), the electrolytic cells 1 to which the gaskets are attached are fastened via the ion exchange membrane 2. This can prevent the electrolyte, alkali metal hydroxides generated by electrolysis, chlorine, hydrogen, etc. from leaking to the outside of the electrolytic cell 1.

[0984] (Ion Exchange Membrane)

[0985] The ion exchange membrane 2 is as described in the above-mentioned section of the ion exchange membrane.

[0986] (Water Electrolysis)

[0987] The electrolytic cell of the present embodiment is an electrolytic cell for performing water electrolysis, and has the following structure: the ion exchange membrane in the electrolytic cell for performing salt electrolysis is replaced with a microporous membrane. In addition, the raw material supplied is water, which is different from the electrolytic cell for performing salt electrolysis. As for other structures, the electrolytic cell for performing water electrolysis can also adopt the same structure as the electrolytic cell for performing salt electrolysis. In the case of salt electrolysis, chlorine is produced in the anode chamber, so the material of the anode chamber uses titanium, but in the case of water electrolysis, only oxygen is produced in the anode chamber, so the same material as the cathode chamber can be used. For example, nickel and the like can be mentioned. In addition, the anode coating is preferably a catalyst coating for oxygen generation. Examples of catalyst coatings include metals, oxides, hydroxides, etc. of platinum group metals and transition metals. For example, elements such as platinum, iridium, palladium, ruthenium, nickel, cobalt, and iron can be used.

[0988] (Applications of Laminated Body)

[0989] As described above, the laminate of this embodiment can improve the efficiency of replacing electrodes in an electrolytic cell, thereby exhibiting excellent electrolytic performance even after replacement. In other words, the laminate of this embodiment can be suitably used as a laminate for replacing components in an electrolytic cell. It should be noted that the laminate used in this application is specifically referred to as a "membrane electrode assembly."

[0990] (Packaging)

[0991] The laminate of the present embodiment is preferably transported and other operations are performed in a state of being sealed in a packaging material. That is, the packaging body of the present embodiment includes the laminate of the present embodiment and the packaging material for packaging the above-mentioned laminate. The packaging body of the present embodiment is constructed as above, so that it can prevent the adhesion of dirt and damage that may occur when the laminate of the present embodiment is transported and other operations are performed. In the case of using it as a component replacement of the electrolytic cell, it is particularly preferred to carry out operations such as transportation in the form of the packaging body of the present embodiment. There is no particular limitation on the packaging material in the present embodiment, and various well-known packaging materials can be applied. In addition, the packaging body of the present embodiment can be manufactured by, but is not limited to, the following methods: for example, the laminate of the present embodiment is packaged with a packaging material in a clean state and then sealed; etc.

[0992] <Third embodiment>

[0993] Here, refer to Figures 43-62 A third embodiment of the present invention will be described in detail.

[0994] [laminated body]

[0995] A laminate according to a third embodiment (hereinafter referred to as "this embodiment" in the section "Third embodiment") comprises a separator and an electrolysis electrode fixed to at least one region of the separator's surface (hereinafter referred to as the "fixed region"), wherein the ratio of the region to the separator's surface is greater than 0% and less than 93%. Due to this configuration, the laminate according to this embodiment can improve the efficiency of electrode replacement in an electrolytic cell, thereby exhibiting excellent electrolysis performance even after replacement.

[0996] That is, according to the laminate of this embodiment, when replacing electrodes, the electrodes can be replaced by the same simple operation as replacing the separators without complicated operations such as peeling off the existing electrodes fixed to the electrolytic cell, thereby significantly improving work efficiency.

[0997] Furthermore, the laminate of this embodiment can maintain or improve the electrolytic performance of the existing electrolysis cell to the same level as when it was new. Therefore, the electrodes fixed to the existing electrolysis cell and functioning as anodes and cathodes only need to function as power supplies, significantly reducing or completely eliminating the need for catalyst coating. The power supplies referred to herein include degraded electrodes (i.e., existing electrodes) and electrodes that are not catalyst-coated.

[0998] [Electrolysis Electrode]

[0999] The electrolysis electrode in this embodiment is not particularly limited as long as it is an electrode used for electrolysis. The area of ​​the surface of the electrolysis electrode facing the diaphragm (corresponding to the area S2 of the current-carrying surface described later) is preferably 0.01 m 2 The "surface facing the diaphragm" refers to the surface of the electrolysis electrode on the side where the diaphragm is present. In other words, the surface facing the diaphragm in the electrolysis electrode may also refer to the surface in contact with the surface of the diaphragm. The area of ​​the surface facing the diaphragm in the electrolysis electrode is 0.01 m 2 In the above case, there is a tendency that sufficient productivity can be ensured, and in particular, sufficient productivity can be obtained in terms of industrial electrolysis. Thus, from the perspective of ensuring sufficient productivity and ensuring the practicality of the laminate used for renewal of the electrolysis unit, the area of ​​the surface of the electrolysis electrode facing the diaphragm is more preferably 0.1 m 2 More than 1m, more preferably 2 This area can be measured, for example, by the method described in the Examples.

[1000] The electrolysis electrode in this embodiment preferably has a force per unit mass / unit area of ​​1.6 N / (mg·cm ) from the viewpoint of achieving good handling properties and good adhesion to separators such as ion exchange membranes or microporous membranes, and power supply bodies (degraded electrodes and electrodes not coated with catalysts). 2 ) or less, more preferably less than 1.6N / (mg·cm 2 ), more preferably less than 1.5N / (mg·cm 2 ), and more preferably 1.2 N / mg·cm 2 Below, more preferably 1.20 N / mg·cm 2 Below. More preferably, it is 1.1N / mg·cm 2 Below, more preferably 1.10 N / mg·cm 2 Below, particularly preferably 1.0 N / mg·cm 2 Below, particularly preferably 1.00 N / mg·cm 2 the following.

[1001] From the perspective of further improving electrolytic performance, it is preferred to exceed 0.005 N / (mg·cm 2 ), more preferably 0.08N / (mg·cm 2 ) or more, more preferably 0.1 N / mg·cm 2 More preferably, 0.14 N / (mg·cm 2 ) or more. From the perspective of facilitating handling in large-scale applications (e.g., 1.5 m × 2.5 m), 0.2 N / (mg·cm 2 )above.

[1002] The applied force can be brought into the above range by, for example, appropriately adjusting the aperture ratio, electrode thickness, arithmetic mean surface roughness, etc., which will be described later. More specifically, for example, increasing the aperture ratio tends to reduce the applied force, while decreasing the aperture ratio tends to increase the applied force.

[1003] In addition, the mass per unit area is preferably 48 mg / cm2 from the perspectives of good handling, good adhesion to separators such as ion exchange membranes and microporous membranes, deteriorated electrodes, and non-catalyst-coated power supplies, as well as economic efficiency. 2 Less than 30 mg / cm 2 Below, more preferably 20 mg / cm 2 Next, from the comprehensive aspects of handling, adhesion and economy, 15 mg / cm 2 The lower limit is not particularly limited, but is, for example, 1 mg / cm 2 about.

[1004] The mass per unit area can be adjusted to the above range by, for example, appropriately adjusting the aperture ratio, electrode thickness, etc., as described later. More specifically, for example, if the thickness is the same, increasing the aperture ratio tends to reduce the mass per unit area, while decreasing the aperture ratio tends to increase the mass per unit area. [10...

Claims

1. A laminate comprising: Electrodes for electrolysis; and a diaphragm or a power supply body in contact with the electrolysis electrode, The mass per unit area of ​​the electrolysis electrode is 20 mg / cm 2 Hereinafter, the force applied per unit mass·unit area of ​​the electrolysis electrode to the separator or the power supply is less than 1.5 N / mg·cm 2 , The applied force is measured using the following method (i) or method (ii): [Method (i)] A nickel plate of 200 mm square with an arithmetic mean surface roughness Ra of 0.7 μm, a thickness of 1.2 mm, and a 170 mm square ion exchange membrane and a 130 mm square electrolytic electrode sample are sequentially stacked, and the stack is fully immersed in pure water, and then excess water attached to the surface of the stack is removed to obtain a measurement sample; under the conditions of a temperature of 23±2°C and a relative humidity of 30±5%, only the electrolytic electrode sample in the measurement sample is raised in the vertical direction at a rate of 10 mm / min using a tensile compression testing machine, and the load when the electrolytic electrode sample is raised in the vertical direction by 10 mm is measured; the measurement is performed three times, and an average value is calculated; the average value is divided by the area of ​​the overlapping portion of the electrolytic electrode sample and the ion exchange membrane, and the mass of the electrolytic electrode sample in the portion overlapping the ion exchange membrane, and the force applied per unit mass and unit area is calculated; The ion exchange membrane is the following ion exchange membrane A: As a reinforcing core material, a 90-denier monofilament made of polytetrafluoroethylene, namely, a PTFE yarn, is used; as a sacrificial yarn, a 35-denier, 6-filament polyethylene terephthalate yarn, namely, a yarn twisted 200 times / m, namely, a PET yarn, is used; first, in the two directions of TD and MD, 24 PTFE yarns / inch and 2 sacrificial yarns are arranged between adjacent PTFE yarns to obtain a woven fabric; the obtained woven fabric is crimped with a roller to obtain a woven fabric with a thickness of 70 μm; Next, prepare resin A, which is a copolymer of CF2=CF2 and CF2=CFOCF2CF(CF3)OCF2CF2COOCH3, and resin B, which is a copolymer of CF2=CF2 and CF2=CFOCF2CF(CF3)OCF2CF2SO2F, which is a dry resin with an ion exchange capacity of 0.85 mg equivalent / g; Using these resins A and B, a two-layer film X having a thickness of 15 μm for the resin A layer and a thickness of 104 μm for the resin B layer was obtained by a co-extrusion T-die method; Next, on a hot plate having a heating source and a vacuum source inside and having fine pores on its surface, a release paper with a cone-shaped embossing process of 50 μm in height, a reinforcing material and a film X were sequentially stacked, and the release paper was removed after heating and decompression for 2 minutes under the conditions of a hot plate surface temperature of 223° C. and a vacuum degree of 0.067 MPa, thereby obtaining a composite film; The obtained composite membrane was immersed in an aqueous solution containing 30% by mass of dimethyl sulfoxide and 15% by mass of potassium hydroxide at 80°C for 20 minutes to perform saponification; thereafter, it was immersed in an aqueous solution containing 0.5N sodium hydroxide at 50°C for 1 hour to replace the counter ion of the ion exchange group with Na, and then washed with water; and then dried at 60°C; In addition, 20% by mass of zirconium oxide having a primary particle size of 1 μm was added to a 5% by mass ethanol solution of the acidic resin of resin B and dispersed to prepare a suspension, which was sprayed onto both sides of the composite membrane by a suspension spray method to form a zirconium oxide coating on the surface of the composite membrane to obtain an ion exchange membrane A; the zirconium oxide coating density measured by fluorescent X-ray was 0.5 mg / cm 2 ; [Method (ii)] A nickel plate of 200 mm square with an arithmetic mean surface roughness Ra of 0.7 μm, a thickness of 1.2 mm, and a 130 mm square electrolytic electrode sample, which was obtained by sandblasting using alumina with grain number 320, and which was then stacked in sequence, and the stack was fully immersed in pure water, and then excess water attached to the surface of the stack was removed, thereby obtaining a measurement sample; under the conditions of a temperature of 23±2°C and a relative humidity of 30±5%, only the electrolytic electrode sample in the measurement sample was raised in the vertical direction at a rate of 10 mm / min using a tensile compression testing machine, and the load when the electrolytic electrode sample was raised 10 mm in the vertical direction was measured; the measurement was carried out 3 times, and an average value was calculated; the average value was divided by the area of ​​the overlapping portion of the electrolytic electrode sample and the nickel plate, and the mass of the electrolytic electrode sample in the portion overlapping the nickel plate, and the force applied per unit mass / unit area was calculated.

2. The laminate according to claim 1, wherein The force applied per unit mass and unit area of ​​the electrolytic electrode to the separator or the power supply exceeds 0.005 N / mg·cm 2 .

3. The laminate according to claim 1 or 2, wherein: The power supply body is a metal wire mesh, a metal non-woven fabric, a punched metal, a metal plate mesh, or a foamed metal.

4. The laminate according to claim 1 or 2, wherein: The separator has, as at least one surface layer, a layer containing a mixture of hydrophilic oxide particles and a polymer into which an ion exchange group is introduced.

5. The laminate according to claim 1 or 2, wherein: A liquid is interposed between the electrolysis electrode and the diaphragm or the power supply body.

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