Method for manufacturing electrolytic cell

Abstract

The present invention relates to a method for manufacturing an electrolytic cell, which is a method for manufacturing a new electrolytic cell by disposing a laminate in an original electrolytic cell provided with a positive electrode, a negative electrode facing the positive electrode, and a separator disposed between the positive electrode and the negative electrode, the method for manufacturing the electrolytic cell comprises: a step (A) in which the laminate is obtained by integrating an electrode for electrolysis and a new separator at a temperature at which the separator does not melt; and a step (B) in which, after the step (A), the separator and the laminate in the original electrolytic cell are exchanged.

Description

[0001] This application is a divisional application of 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". The application number of the divisional application of the original application corresponding to this application is 202210236925.0, the filing date is March 10, 2022, and the name of the invention is "laminate, electrolytic cell and method for manufacturing the same, 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 producing an electrolytic cell, a method for renewing an electrode, a method for renewing a laminate, and a method for producing a wound body. Background Art

[0003] In the electrolysis of aqueous alkali metal chloride solutions such as saline and the electrolysis of water (hereinafter referred to as "electrolysis"), a method using an electrolytic cell is used, which has a diaphragm, more specifically, an ion exchange membrane or a microporous membrane. In most cases, the electrolytic cell has a large number of electrolytic cells connected in series. Electrolysis is performed by interposing a diaphragm between each electrolytic cell. In the electrolytic cell, the cathode chamber having a cathode and the anode chamber having an anode are arranged back to back with a partition wall (back plate) or by pressing using pressing pressure, bolting, etc.

[0004] At present, 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) or the like. 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 cells 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 the electrolysis operation is started and continued, due to various reasons, each component will deteriorate, the electrolysis performance will decrease, and each component will need to be replaced at a certain point. 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, and the old electrode must be peeled off, and then a new electrode must be set, and then fixed by welding or the like, and transported to the electrolysis factory and returned to the electrolytic cell. This is a problem of 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 an electrolysis unit of actual commercial size (for example, 1.5m high and 3m wide). In addition, due to the significantly poor electrolytic performance (electrolytic 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 electrode, laminate, wound body, electrolytic cell, electrolytic cell manufacturing method, electrode renewal method, laminate renewal method and wound body manufacturing method.

[0012] (1st Purpose)

[0013] One of the objects of the present invention is to provide an electrode, a laminate and a wound body for electrolysis which are easy to transport and handle, can greatly simplify the operation when starting 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 also exhibit excellent electrolytic performance after the 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 from a different aspect from the second object described above, and can also exhibit excellent electrolytic performance after the replacement.

[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 updating a laminated body, which have excellent electrolytic performance and can prevent damage to the diaphragm.

[0020] (Purpose 5)

[0021] One of the objects of the present invention is to provide a method for manufacturing an electrolytic cell, a method for updating an electrode, and a method for manufacturing a wound body, which can improve the work efficiency when updating an electrode 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 which can improve the working efficiency when the electrodes in the electrolytic cell are renewed from a different aspect from the fifth object mentioned above.

[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 operating efficiency when the electrodes in the electrolytic cell are renewed from a different aspect from the fifth and sixth objects mentioned above.

[0026] Means for solving problems

[0027] The inventors have repeatedly conducted in-depth research to achieve the first object, and found that by making an electrolysis electrode with a small mass per unit area and capable of bonding to a diaphragm such as an ion exchange membrane and a microporous membrane or a deteriorated electrode with a relatively weak force, transportation and handling become easy, and the operation when starting a new electrolytic cell or updating a deteriorated component can be greatly simplified, thereby greatly improving the performance compared to the electrolysis performance of the prior art. In addition, it was found that the electrolysis performance can be equal to or improved to that of an existing electrolysis unit with complicated updating operations, thereby completing 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 are applied to both sides of a membrane of a perfluorocarbon polymer having an ion exchange group, and the obtained membrane (170 mm square) and an electrode sample for electrolysis (130 mm square) are sequentially laminated. Under the conditions of a temperature of 23±2°C and a relative humidity of 30±5%, the laminate is placed on a curved surface of a polyethylene tube (outer diameter 145 mm) in such a manner that the electrode sample for electrolysis in the laminate is on the outside, and the laminate and the tube are fully immersed in pure water to remove excess water attached to the surface of the laminate and the tube. After 1 minute, the ratio (%) of the area of ​​the membrane of the perfluorocarbon polymer having an ion exchange group applied with inorganic particles and a binder on both sides and the electrode sample for electrolysis are measured.

[0034] [4] The electrode for electrolysis according to any one of [1] to [3], wherein the electrode for electrolysis has a porous structure and 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 temperature 23±2°C and relative humidity 30±5%, a sample of a laminated ion exchange membrane and the above-mentioned electrolytic electrode was wound and fixed on the curved surface of a vinyl chloride core material with an outer diameter of Φ32mm. After standing for 6 hours, the electrolytic electrode was separated and placed on a horizontal plate. The vertical height L of both ends of the electrolytic electrode was measured. 1 and L 2 , and take their average value 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 of the present invention have conducted repeated and in-depth studies to achieve the second objective, and have found that the following laminated body can facilitate transportation and handling, greatly simplify the operation of 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 a power supply body 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 diaphragm 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 / unit area of ​​the electrolytic electrode to the separator or the power supply exceeds 0.005 N / mg·cm 2 .

[0053] [2-3]

[0054] The laminate as described in [2-1] or [2-2], wherein the power supply body is a metal mesh, a metal nonwoven fabric, a punched metal, a metal plate 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 containing 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 a separator and an electrolytic electrode 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 diaphragm,

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

[0066] [3-2]

[0067] A 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.

[0072] [3-5]

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

[0074] [3-6]

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

[0076] [3-7]

[0077] In the laminate described in [3-5] or [3-6], at least a portion of the fixing member fixes the diaphragm and the electrolytic 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 above-mentioned anode frame;

[0092] A cathode facing the above-mentioned anode;

[0093] A cathode frame supporting the above-mentioned cathode;

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

[0095] A laminate, which is a laminate of a separator and an electrolysis electrode, and is disposed between the above-mentioned anode-side gasket and the above-mentioned cathode-side gasket,

[0096] At least a part of the above-mentioned laminate is clamped by the above-mentioned anode-side gasket and the above-mentioned cathode-side gasket,

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

[0098] [4-2]

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

[0100] [4-3]

[0101] The electrolytic cell according to [4-1] or [4-2], wherein the value measured for the above-mentioned electrolysis electrode 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 formed by laminating an ion exchange membrane and the above-mentioned electrolysis electrode is wound and fixed to the curved surface of a vinyl chloride core material with an outer diameter of Φ32 mm. After standing for 6 hours, when the electrolysis electrode is separated and placed on a horizontal plate, the vertical heights L1 and L2 at both ends of the electrolysis electrode are measured, and their average value is 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 above-mentioned electrolysis electrode is 48 mg / cm 2 or less.

[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 as described in 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 inside the separator and fixed thereto.

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

[0120] [4-12]

[0121] In the electrolytic cell described in [4-10] or [4-11], in the laminate, the fixing member includes a soluble material that is soluble in an electrolyte solution.

[0122] [4-13]

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

[0124] [4-14]

[0125] The electrolytic cell as described in 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 electrolytic 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 laminated body 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 as described in any one of [4-1] to [4-16], wherein:

[0136] The updating method has the following steps:

[0137] The step of separating the laminate from the anode-side gasket and the cathode-side gasket to thereby 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, which is a method for manufacturing a new electrolytic cell by arranging an electrolytic electrode or a laminate of the electrolytic electrode and a new diaphragm 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 electrolytic electrode or the wound body of the laminate.

[0144] [5-2]

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

[0146] [5-3]

[0147] The method for producing an electrolytic cell according to [5-1] or [5-2], further comprising a 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], wherein the method 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 electrolytic electrode.

[0153] [5-6]

[0154] The electrode renewal method according to [5-5] further comprises a step (A') of obtaining the wound body by keeping the electrolytic 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 releasing the wound state of 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 is 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 arranged between the anode and the cathode, wherein:

[0161] The method for producing the wound body comprises 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, which is a method for manufacturing a new electrolytic cell by arranging a laminate 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:

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

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

[0168] Step (B), after the step (A), replacing the diaphragm in the existing electrolytic cell with the laminate.

[0169] [6-2]

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

[0171] The present inventors have conducted repeated and intensive studies to achieve the seventh objective, 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, which is a method for manufacturing a new electrolytic cell by arranging a laminate including an electrolytic electrode and a new diaphragm 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:

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

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

[0177] Step (B) is to replace the separator and the laminate after the step (A).

[0178] [7-2]

[0179] The method for manufacturing an electrolytic cell as described in [7-1], wherein the step (A) is performed by sliding the anode and the cathode in their arrangement directions, respectively.

[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 in 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 step (B), the laminate is fixed to at least one surface of the anode and the cathode at a temperature at which the laminate does not melt.

[0184] [7-5]

[0185] A method for manufacturing an electrolytic cell, which is a method for manufacturing a new electrolytic cell by arranging an electrolytic 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 manufacturing method of the electrolytic cell comprises the following steps:

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

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

[0189] Effects of the Invention

[0190] (1) The electrolytic electrode of the present invention can be easily transported and handled, and the operation when starting a new electrolytic cell or replacing a deteriorated electrode can be greatly simplified, and the electrolytic performance can be maintained or improved.

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

[0192] (3) According to the laminate of the present invention, it is possible to improve the work efficiency when the electrodes in the electrolytic cell are renewed from a different aspect from the above (2), and further, to exhibit excellent electrolytic performance even after renewal.

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

[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 the electrodes in the electrolytic cell are renewed 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 renewed from a different aspect from the above (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 2is a schematic cross-sectional view showing one embodiment of an ion exchange membrane.

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

[0200] Figure 4 This is a schematic diagram for explaining a method of forming the communicating pores of the 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] Fig. 9 This is a schematic cross-sectional view of a reverse current absorber included in an electrolytic cell.

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

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

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

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

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

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

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

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

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

[0215] Fig.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] Fig. 20 This is a schematic diagram of the electrode produced in Comparative Example 15.

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

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

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

[0220] Fig.24 It is a schematic diagram for explaining the opening ratio of the reinforcing core material constituting the ion exchange membrane.

[0221] Fig.25 This is a schematic diagram for explaining a method of forming the communicating pores of the ion exchange membrane.

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

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

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

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

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

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

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

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

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

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

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

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

[0234] Fig.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] Fig.39 This is a schematic diagram of the electrode produced in Example 35.

[0236] Fig.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] Fig.41 This is a schematic diagram of the electrode produced in Example 36.

[0238] Fig.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] Fig.43 This is a schematic cross-sectional view of an electrode for electrolysis in one embodiment of the present invention.

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

[0241] Fig.45 It is a schematic diagram for explaining the opening ratio of the reinforcing core material constituting the ion exchange membrane.

[0242] Fig.46 This is a schematic diagram for explaining a method of forming the communicating pores of the ion exchange membrane.

[0243] Fig.47 middle, Fig.47 A is a schematic cross-sectional view of a laminated body illustrating a mode in which at least a part of the electrolytic electrode is fixed through a separator. Fig.47 B is shown for obtaining Fig.47 A diagram illustrating the process of the structure of A.

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

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

[0246] Fig.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 a separator and an electrode for electrolysis.

[0247] Fig.51 middle, Fig.51 A is a schematic cross-sectional view of a laminated body illustrating a mode in which at least a part of a fixing member holds and fixes a separator and an electrolytic electrode from the outside. Fig.51 B is a schematic cross-sectional view of a laminated body illustrating a mode in which at least a part of a fixing member fixes the diaphragm and the electrolytic electrode by magnetic force.

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

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

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

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

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

[0253] Fig.57 This is an explanatory diagram showing a laminate in Example 1.

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

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

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

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

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

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

[0260] Fig.64 middle, Fig.64 A is a schematic cross-sectional view showing a state in which two electrolytic units in a conventional electrolytic cell are connected in series. Fig.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] Fig.65 is a schematic diagram of an electrolytic cell.

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

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

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

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

[0266] Fig.70 It is a schematic diagram for explaining the opening ratio of the reinforcing core material constituting the ion exchange membrane.

[0267] Fig.71 This is a schematic diagram for explaining a method of forming the communicating pores of the ion exchange membrane.

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

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

[0270] Fig.74 middle, Fig.74 A is a schematic cross-sectional view of a laminated body illustrating a mode in which at least a part of the electrolytic electrode is fixed through a separator. Fig.74 B is shown for obtaining Fig.74 A diagram illustrating the process of the structure of A.

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

[0272] Fig.76 middle, Fig.76 A~ Fig.76 C is a schematic cross-sectional view 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 electrolytic electrode.

[0273] Fig.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 a separator and an electrode for electrolysis.

[0274] Fig.78 middle, Fig.78 A is a schematic cross-sectional view of a laminated body illustrating a mode in which at least a part of a fixing member holds and fixes a separator and an electrolytic electrode from the outside. Fig.78 B is a schematic cross-sectional view of a laminated body illustrating a mode in which at least a part of a fixing member fixes the diaphragm and the electrolytic electrode by magnetic force.

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

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

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

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

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

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

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

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

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

[0284] Fig.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] Fig.89 This is a schematic diagram of the electrode produced in Example 37.

[0286] Fig.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] Fig.91 is a schematic cross-sectional view of an electrolysis cell.

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

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

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

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

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

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

[0294] Fig.98 It is a schematic diagram for explaining the opening ratio of the reinforcing core material constituting the ion exchange membrane.

[0295] Fig.99 This is a schematic diagram for explaining a method of forming the communicating pores of the ion exchange membrane.

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

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

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

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

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

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

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

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

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

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

[0306] Fig.110 It is a schematic diagram for explaining the opening ratio of the reinforcing core material constituting the ion exchange membrane.

[0307] Fig.111 This is a schematic diagram for explaining a method of forming the communicating pores of the ion exchange membrane.

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

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

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

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

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

[0313] Fig.117 middle, Fig.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. Fig.117 (B) is Fig.117 (A) Corresponding schematic stereogram.

[0314] Fig.118 middle, Fig.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. Fig.118 (B) is Fig.118 (A) Corresponding schematic stereogram.

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

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

[0317] Fig.121 It is a schematic diagram for explaining the opening ratio of the reinforcing core material constituting the ion exchange membrane.

[0318] Fig.122 This is a schematic diagram for explaining a method of forming the communicating pores of the ion exchange membrane.

[0319] Explanation of symbols

[0320] <Diagram corresponding to the first embodiment>

[0321] for Figure 1 Explanation of symbols

[0322] 10···electrode substrate for electrolysis, 20···first layer, 30···second layer, 100···electrode for electrolysis.

[0323] for Figures 2 to 4 Explanation of symbols

[0324] 1···ion exchange membrane, 2···carboxylic acid layer, 3···sulfonic acid layer, 4···reinforced core material, 10···membrane body, 11a, 11b···coating layer, 21, 22···reinforced core material, 100···electrolyzer, 200···anode, 300···cathode, 52···reinforced wire, 504a···sacrificial wire, 504···connecting hole.

[0325] for Figures 5 to 9 Explanation of symbols

[0326] 1···electrolysis unit, 2···ion exchange membrane, 4···electrolytic cell, 5···pressurizer, 6···cathode terminal, 7···anode terminal, 10···anode chamber, 11···anode, 12···anode gasket, 13···cathode gasket, 18···reverse current absorber, 18a···substrate, 18b···reverse current absorbing layer, 19···bottom of anode chamber, 20···cathode chamber, 21···cathode, 22···metal elastic body, 23···current collector, 24···support body, 30···separation wall, 40···cathode structure for electrolysis.

[0327] for Fig.10 Explanation of symbols

[0328] 1···Clamping jig (SUS), 2···Electrode, 3···Diaphragm, 4···Nickel plate (sandblasted with alumina of grain number 320), 100···Front surface, 200···Side surface.

[0329] for Figures 11 to 13 Explanation of symbols

[0330] 1···diaphragm, 2a···polyethylene tube having an outer diameter of 280 mm, 2b···polyethylene tube having an outer diameter of 145 mm, 3···peeling portion, 4···closed portion, 5···electrode.

[0331] for Fig.14 Explanation of symbols

[0332] 1···PVC (polyvinyl chloride) pipe, 2···ion exchange membrane, 3···electrode, 4···fixed plate

[0333] for Fig.15 Explanation of symbols

[0334] 1···fixed plate, 2···deformed electrode, 10···fixed electrode fixture, 20···direction of applied force

[0335] for Figures 16 to 21 Explanation of symbols

[0336] 1···110mm nickel wire, 2···950mm nickel wire, 3···frame

[0337] <Diagram corresponding to the second embodiment>

[0338] for Fig. 22 Explanation of symbols

[0339] 10···electrode substrate for electrolysis, 20···first layer, 30···second layer, 100···electrode for electrolysis.

[0340] for Figures 23 to 25 Explanation of symbols

[0341] 1···ion exchange membrane, 2···carboxylic acid layer, 3···sulfonic acid layer, 4···reinforced core material, 10···membrane body, 11a, 11b···coating layer, 21, 22···reinforced core material, 100···electrolyzer, 200···anode, 300···cathode, 52···reinforced wire, 504a···sacrificial wire, 504···connecting hole 504.

[0342] for Figures 26-30 Explanation of symbols

[0343] 1···electrolysis unit, 2···ion exchange membrane, 4···electrolytic cell, 5···pressurizer, 6···cathode terminal, 7···anode terminal, 10···anode chamber, 11···anode, 12···anode gasket, 13···cathode gasket, 18···reverse current absorber, 18a···substrate, 18b···reverse current absorbing layer, 19···bottom of anode chamber, 20···cathode chamber, 21···cathode, 22···metal elastic body, 23···current collector, 24···support body, 30···separation wall, 40···cathode structure for electrolysis.

[0344] for Fig.31 Explanation of symbols

[0345] 1···Clamping jig (SUS), 2···Electrode, 3···Diaphragm, 4···Nickel plate (sandblasted with alumina of grain number 320), 100···Front surface, 200···Side surface.

[0346] for Figures 32-34 Explanation of symbols

[0347] 1···diaphragm, 2a···polyethylene tube having an outer diameter of 280 mm, 2b···polyethylene tube having an outer diameter of 145 mm, 3···peeling portion, 4···closed portion, 5···electrode.

[0348] for Fig.35 Explanation of symbols

[0349] 1···PVC (polyvinyl chloride) pipe, 2···ion exchange membrane, 3···electrode, 4···fixed plate

[0350] for Fig.36 Explanation of symbols

[0351] 1···fixed plate, 2···deformed electrode, 10···fixed electrode fixture, 20···direction of applied force

[0352] for Figures 37-42Explanation of symbols

[0353] 1···110mm nickel wire, 2···950mm nickel wire, 3···frame

[0354] <Diagram corresponding to the third embodiment>

[0355] for Fig.43 Explanation of symbols

[0356] 10···electrode substrate for electrolysis, 20···first layer, 30···second layer, 100···electrode for electrolysis.

[0357] for Figures 44-46 Explanation of symbols

[0358] 1···ion exchange membrane, 2···carboxylic acid layer, 3···sulfonic acid layer, 4···reinforced core material, 10···membrane body, 11a, 11b···coating layer, 21, 22···reinforced core material, 100···electrolyzer, 200···anode, 300···cathode, 52···reinforced wire, 504a···sacrificial wire, 504···connecting hole 504.

[0359] for Figures 47 to 51 Explanation of symbols

[0360] 1···Laminate, 2···Electrode for electrolysis, 2a···Inner surface of the electrode for electrolysis, 2b···Outer surface of the electrode for electrolysis, 3···Separator, 3a···Inner surface of the separator, 3b···Outer surface of the separator, 7···Fixing member.

[0361] for Figures 52-56 Explanation of symbols

[0362] 1···electrolysis unit, 2···ion exchange membrane, 4···electrolytic cell, 5···pressurizer, 6···cathode terminal, 7···anode terminal, 10···anode chamber, 11···anode, 12···anode gasket, 13···cathode gasket, 18···reverse current absorber, 18a···substrate, 18b···reverse current absorbing layer, 19···bottom of anode chamber, 20···cathode chamber, 21···cathode, 22···metal elastic body, 23···current collector, 24···support body, 30···separation wall, 40···cathode structure for electrolysis.

[0363] <Diagram corresponding to the fourth embodiment>

[0364] for Figures 63-67 Explanation of symbols

[0365] 1···electrolysis unit, 2···ion exchange membrane, 4···electrolytic cell, 5···pressurizer, 6···cathode terminal, 7···anode terminal, 10···anode chamber, 11···anode, 12···anode gasket, 13···cathode gasket, 18···reverse current absorber, 18a···substrate, 18b···reverse current absorbing layer, 19···bottom of anode chamber, 20···cathode chamber, 21···cathode, 22···metal elastic body, 23···current collector, 24···support body, 30···separation wall, 40···cathode structure for electrolysis.

[0366] for Fig.68 Explanation of symbols

[0367] 10···electrode substrate for electrolysis, 20···first layer, 30···second layer, 100···electrode for electrolysis.

[0368] for Figures 69-71 Explanation of symbols

[0369] 1···ion exchange membrane, 2···carboxylic acid layer, 3···sulfonic acid layer, 4···reinforced core material, 10···membrane body, 11a, 11b···coating layer, 21, 22···reinforced core material, 100···electrolyzer, 200···anode, 300···cathode, 52···reinforced wire, 504a···sacrificial wire, 504···connecting hole.

[0370] for Figures 72-78 Explanation of symbols

[0371] 1···laminate, 2···electrode for electrolysis, 2a···inner surface of electrode for electrolysis, 2b···outer surface of electrode for electrolysis, 3···diaphragm, 3a···inner surface of diaphragm, 3b···outer surface of diaphragm, 7···fixing member, A···gasket, B···diaphragm, C···electrode for electrolysis, A1···outermost peripheral edge of gasket, B1···outermost peripheral edge of diaphragm, C1···outermost peripheral edge of electrode for electrolysis.

[0372] for Fig.79 Explanation of symbols

[0373] 1···Clamping jig (SUS), 2···Electrode, 3···Diaphragm, 4···Nickel plate (sandblasted with alumina of grain number 320), 100···Front surface, 200···Side surface.

[0374] for Figures 80-82 Explanation of symbols

[0375] 1···diaphragm, 2a···polyethylene tube having an outer diameter of 280 mm, 2b···polyethylene tube having an outer diameter of 145 mm, 3···peeling portion, 4···closed portion, 5···electrode.

[0376] for Fig.84 Explanation of symbols

[0377] 1···fixed plate, 2···deformed electrode, 10···fixed electrode fixture, 20···direction of applied force

[0378] for Figures 85-90 Explanation of symbols

[0379] 1···110mm nickel wire, 2···950mm nickel wire, 3···frame

[0380] <Figure corresponding to the fifth embodiment>

[0381] for Figures 91 to 95 Explanation of symbols

[0382] 1···electrolysis unit, 2···ion exchange membrane, 4···electrolytic cell, 5···pressurizer, 6···cathode terminal, 7···anode terminal, 10···anode chamber, 11···anode, 12···anode gasket, 13···cathode gasket, 18···reverse current absorber, 18a···substrate, 18b···reverse current absorbing layer, 19···bottom of anode chamber, 20···cathode chamber, 21···cathode, 22···metal elastic body, 23···current collector, 24···support body, 30···separation wall, 40···cathode structure for electrolysis.

[0383] for Fig.96 Explanation of symbols

[0384] 10···electrode substrate for electrolysis, 20···first layer, 30···second layer, 100···electrode for electrolysis.

[0385] for Figures 97 to 99 Explanation of symbols

[0386] 1···ion exchange membrane, 2···carboxylic acid layer, 3···sulfonic acid layer, 4···reinforced core material, 10···membrane body, 11a, 11b···coating layer, 21, 22···reinforced core material, 100···electrolyzer, 200···anode, 300···cathode, 52···reinforced wire, 504a···sacrificial wire, 504···connecting hole.

[0387] <Figure Corresponding to Sixth Embodiment>

[0388] for Figures 103-107Explanation of symbols

[0389] 1···electrolysis unit, 2···ion exchange membrane, 4···electrolytic cell, 5···pressurizer, 6···cathode terminal, 7···anode terminal, 10···anode chamber, 11···anode, 12···anode gasket, 13···cathode gasket, 18···reverse current absorber, 18a···substrate, 18b···reverse current absorbing layer, 19···bottom of anode chamber, 20···cathode chamber, 21···cathode, 22···metal elastic body, 23···current collector, 24···support body, 30···separation wall, 40···cathode structure for electrolysis.

[0390] for Fig.108 Explanation of symbols

[0391] 10···electrode substrate for electrolysis, 20···first layer, 30···second layer, 100···electrode for electrolysis.

[0392] for Figures 109-111 Explanation of symbols

[0393] 1···ion exchange membrane, 2···carboxylic acid layer, 3···sulfonic acid layer, 4···reinforced core material, 10···membrane body, 11a, 11b···coating layer, 21, 22···reinforced core material, 100···electrolyzer, 200···anode, 300···cathode, 52···reinforced wire, 504a···sacrificial wire, 504···connecting hole.

[0394] <Figure corresponding to the seventh embodiment>

[0395] for Figures 112-118 Explanation of symbols

[0396] 1···electrolytic unit, 2···ion exchange membrane, 2a···novel ion exchange membrane, 4···electrolytic cell, 5···pressurizer, 6···cathode terminal, 7···anode terminal, 8···electrolytic cell frame, 9···laminate, 10···anode chamber, 11···anode, 12···anode gasket, 13···cathode gasket, 18···reverse current absorber, 18a···substrate, 18b···reverse current absorbing layer, 19···bottom of anode chamber, 20···cathode chamber, 21···cathode, 22···metal elastic body, 23···current collector, 24···support, 30···separation wall, 40···electrolytic cathode structure, 100···electrolytic electrode.

[0397] for Fig.119 Explanation of symbols

[0398] 10···electrode substrate for electrolysis, 20···first layer, 30···second layer, 100···electrode for electrolysis.

[0399] for Figures 120-122 Explanation of symbols

[0400] 1···ion exchange membrane, 2···carboxylic acid layer, 3···sulfonic acid layer, 4···reinforced core material, 10···membrane body, 11a, 11b···coating layer, 21, 22···reinforced core material, 100···electrolyzer, 200···anode, 300···cathode, 52···reinforced wire, 504a···sacrificial wire, 504···connecting hole. DETAILED DESCRIPTION

[0401] 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 according to <1st embodiment> to <7th embodiment>, respectively, as needed. The following embodiments are examples for illustrating the present invention, and the present invention is not limited to the following contents. In addition, the accompanying drawings show an example of an embodiment, but the embodiment is not limited to this and is interpreted. The present invention can be implemented with appropriate deformation within the scope of its main points. It should be noted that the positional relationships such as up, down, left, and right in the accompanying drawings are based on the positional relationships shown in the accompanying drawings unless otherwise stated. The dimensions and proportions of the accompanying drawings are not limited to the dimensions and proportions shown in the drawings.

[0402] <First Embodiment>

[0403] Here, refer to Figures 1 to 21 , the first embodiment of the present invention is described in detail.

[0404] [Electrode for electrolysis]

[0405] The mass per unit area of ​​the electrode for electrolysis of the first embodiment (hereinafter referred to as "the present embodiment" in the section <the first embodiment>) is 48 mg / cm in terms of good handling properties, good adhesion to diaphragms such as ion exchange membranes or microporous membranes, deteriorated electrodes, and power supply bodies that are not coated with catalysts, and 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.

[0406] The mass per unit area can be within the above range by, for example, appropriately adjusting the aperture ratio, the thickness of the electrode, etc. More specifically, for example, if the thickness is the same, the mass per unit area tends to decrease when the aperture ratio is increased, and the mass per unit area tends to increase when the aperture ratio is decreased.

[0407] The electrolytic electrode of this embodiment has a force of 0.08 N / (mg·cm2) per unit mass·unit area 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 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) 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 1.6 N / (mg·cm 2 ), and more preferably less than 1.5 N / (mg·cm 2 ), and more preferably 1.2 N / mg·cm 2 Below, more preferably 1.20 N / mg·cm 2 More preferably, it is 1.1 N / 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.

[0408] When the electrode for electrolysis of the present embodiment is an electrode with a wide elastic deformation region, the thickness of the electrode for electrolysis is preferably 315 μm or less, more preferably 220 μm or less, more preferably 170 μm or less, and even more preferably 150 μm or less, particularly preferably 145 μm or less, 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 obtaining better handling properties and better adhesion to diaphragms such as ion exchange membranes or microporous membranes, degraded electrodes, and power supply bodies that are not coated with catalysts. If it is 135 μm or less, good handling properties can be obtained. In addition, from the same aspects as above, it is preferably 130 μm or less, more preferably less than 130 μm, 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 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, in the present embodiment, "wide elastic deformation region" means that the electrolysis electrode is wound into a wound body, and after the wound state is unwound, it is difficult to produce warping from the winding. In addition, the thickness of the electrolysis electrode, when including the catalyst layer described later, refers to the thickness of the electrolysis electrode substrate and the catalyst layer combined.

[0409] 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 updating the diaphragm without complicated replacement operations such as peeling off the electrode fixed to the electrolysis unit, so the operating efficiency is greatly improved. 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), the electrode for electrolysis of the present embodiment can be used as an electrode by simply sticking it to the power supply, so the catalyst coating can also be greatly reduced or completely eliminated.

[0410] Furthermore, according to the electrode for electrolysis of this embodiment, the electrolysis performance can be made equal to or further improved as that of a new product.

[0411] The electrode for electrolysis of the present embodiment can be stored in a state (in a roll or the like) wound around a tube made of polyvinyl chloride, for example, and can be transported to a customer, and thus can be handled very easily.

[0412] 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.

[0413] The above-mentioned applied force can be within the above-mentioned range by appropriately adjusting the aperture ratio, electrode thickness, arithmetic mean surface roughness, etc., which will be described later. More specifically, for example, if the aperture ratio is increased, the applied force tends to decrease, and if the aperture ratio is decreased, the applied force tends to increase.

[0414] [Method (i)]

[0415] A nickel plate (thickness 1.2 mm, 200 mm square) obtained by sandblasting with alumina of 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 of a perfluorocarbon polymer having an ion exchange group, and an electrode sample for electrolysis (130 mm square) are sequentially stacked, and the stack is fully immersed in pure water, and the excess water attached to the surface of the stack is removed to obtain a sample for measurement. It should be noted that the arithmetic mean surface roughness (Ra) of the nickel plate after sandblasting is 0.7 μm. The specific calculation method of the arithmetic mean surface roughness (Ra) is as described in the examples.

[0416] Under the conditions of temperature 23±2°C and relative humidity 30±5%, only the electrolysis electrode sample in the measurement sample was raised in the vertical direction at 10 mm / min using a tension-compression tester, and the load when the electrolysis electrode sample was raised in the vertical direction by 10 mm was measured. This measurement was performed 3 times, and the average value was calculated.

[0417] The average value was 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 to calculate the force applied per unit mass / unit area (1) (N / mg·cm 2 ).

[0418] The force (1) applied per unit mass / unit area obtained by the method (i) 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 more preferably 0.2 N / (mg·cm ) from the perspective of easier handling in large-scale (e.g., 1.5 m×2.5 m) conditions. 2 The upper limit is not particularly limited, but is preferably 1.6 N / (mg·cm 2 ) or less, more preferably less than 1.6 N / (mg·cm 2 ), and more preferably less than 1.5 N / (mg·cm 2 ), and more preferably 1.2 N / mg·cm 2 Below, more preferably 1.20 N / mg·cm 2 More preferably, it is 1.1 N / mg·cm 2 Below, more preferably 1.10 N / mg·cm 2 Below, particularly preferably 1.0 N / mg·cm 2 Below, especially preferably 1.00 N / mg·cm 2 the following.

[0419] If the electrode for electrolysis of the present 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 updated, it is not necessary to replace the cathode and anode fixed to the electrolysis unit by welding or the like, thereby greatly improving the working efficiency. In addition, by using the electrode for electrolysis of the present embodiment as an integrated electrode with an ion exchange membrane, the electrolysis performance can be made the same as that of a new product or further improved.

[0420] When shipping a new electrolysis unit, in the prior art, the electrode fixed to the electrolysis unit is coated with a catalyst, but by combining the electrode for electrolysis of the present embodiment with the electrode that has not been coated with a catalyst, it can be used as an electrode, so that the manufacturing process or the amount of catalyst for the catalyst coating can be greatly reduced or completely eliminated. The electrode of the prior art in which the catalyst coating is greatly reduced or completely eliminated can be electrically connected to the electrode for electrolysis of the present embodiment and function as a power supply for circulating current.

[0421] [Method (ii)]

[0422] A nickel plate (1.2 mm thick, 200 mm square, the same nickel plate as in the above method (i)) obtained by sandblasting with alumina of grain number 320 and an electrolytic electrode sample (130 mm square) were sequentially stacked, and the stack was fully immersed in pure water, and the excess water attached to the surface of the stack was removed to obtain a measurement sample. Under the conditions of temperature 23±2°C and relative humidity 30±5%, only the electrolytic electrode sample in the measurement sample was raised in the vertical direction at 10 mm / min using a tension and compression tester, and the load when the electrolytic electrode sample was raised in the vertical direction by 10 mm was measured. This measurement was carried out 3 times, and the average value was calculated.

[0423] 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 / unit area (2) (N / mg·cm 2 ).

[0424] The force (2) applied per unit mass / unit area obtained by method (ii) 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 1.6 N / (mg·cm 2 ), and more preferably less than 1.5 N / (mg·cm 2 ), and more preferably 1.2 N / mg·cm 2 Below, more preferably 1.20 N / mg·cm 2 More preferably, it is 1.1 N / mg·cm 2 Below, more preferably 1.10 N / mg·cm 2 Below, particularly preferably 1.0 N / mg·cm 2 Below, especially preferably 1.00 N / mg·cm 2 the following.

[0425] If the electrolysis electrode of the present embodiment satisfies the applied force (2), it can be stored in a state of being wound around a tube made of polyvinyl chloride (in a roll, etc.), and transported to a customer, etc., and handling becomes very easy. In addition, by attaching the electrolysis electrode of the present embodiment to a deteriorated electrode, the electrolysis performance can be made the same as that of a new one or further improved.

[0426] In the present embodiment, the liquid between the diaphragm such as ion exchange membrane or microporous membrane and the electrode for electrolysis, or the power supply (degraded electrode or 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, organic solvent, etc. 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 large surface tension is preferred. As liquid, the following substances (the numerical value in brackets is the surface tension of the liquid) can be cited.

[0427] Hexane (20.44mN / m), acetone (23.30mN / m), methanol (24.00mN / m), ethanol (24.05mN / m), ethylene glycol (50.21mN / m), water (72.76mN / m)

[0428] If the liquid has a large surface tension, the diaphragm and the electrode for electrolysis, or the metal porous plate or the metal plate (electric power source) and the electrode for electrolysis are integrated (formed into a laminate), and the electrode renewal becomes easy. The amount of liquid between the diaphragm and the electrode for electrolysis, or the metal porous plate or the metal plate (electric power source) and the electrode for electrolysis is sufficient to be adhered to each other by surface tension, and the amount of liquid is small, so even if it is mixed into the electrolyte after the electrolysis unit is set in the laminate, it will not affect the electrolysis itself.

[0429] 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 is water, or dissolving caustic soda, potassium hydroxide, lithium hydroxide, sodium bicarbonate, potassium bicarbonate, sodium carbonate, potassium carbonate, etc. in water to become an alkaline aqueous solution. In addition, it is also possible to make these liquids contain a surfactant and adjust the surface tension. By including a surfactant, the adhesion between the diaphragm and the electrode for electrolysis or the metal plate and the electrode for electrolysis changes, and the processability can be adjusted. As a surfactant, there is no particular restriction, and any of an ionic surfactant and a nonionic surfactant can be used.

[0430] The electrode for electrolysis of the present embodiment preferably includes an electrode substrate for electrolysis and a catalyst layer. The thickness (gauge thickness) of the electrode substrate for electrolysis is not particularly limited, and is preferably 300 μm or less, more preferably 205 μm or less, more preferably 155 μm or less, and more preferably 135 μm or less, more preferably 125 μm or less, more preferably 120 μm or less, and more preferably 100 μm or less, and from the perspective of processability and economy, it is more preferably 50 μm or less. The lower limit is not particularly limited, for example, 1 μm, preferably 5 μm, and more preferably 15 μm.

[0431] The electrode for electrolysis of the present embodiment is not particularly limited, but the ratio measured by the following method (2) is preferably 90% or more, more preferably 92% or more, from the perspective of obtaining good handling properties and good adhesion to diaphragms such as ion exchange membranes or microporous membranes, deteriorated electrodes, and power supply bodies that are not coated with catalysts. Furthermore, from the perspective of facilitating handling under large sizes (e.g., sizes of 1.5 m×2.5 m), it is further preferably 95% or more. The upper limit is 100%.

[0432] [Method (2)]

[0433] An ion exchange membrane (170 mm square) and an electrode sample for electrolysis (130 mm square) were stacked in sequence. The stack was placed on a 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 electrode sample for electrolysis on the outside. The stack and the tube were fully immersed in pure water to remove excess water attached to the surface of the stack and the tube. After 1 minute, the ratio (%) of the area of ​​the portion where the ion exchange membrane (170 mm square) and the electrode sample for electrolysis were in close contact was measured.

[0434] The electrode for electrolysis of the present embodiment is not particularly limited, but the ratio measured by the following method (3) is preferably 75% or more, more preferably 80% or more, from the perspective of obtaining good handling properties, good adhesion to diaphragms such as ion exchange membranes or microporous membranes, degraded electrodes, and power supply bodies that are not coated with catalysts, and being able to be rolled up appropriately and bent well. Furthermore, from the perspective of facilitating handling under large sizes (e.g., sizes of 1.5 m×2.5 m), it is further preferably 90% or more. The upper limit is 100%.

[0435] [Method (3)]

[0436] An ion exchange membrane (170 mm square) and an electrode sample for electrolysis (130 mm square) were stacked in sequence. The stack was placed on a 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 electrode sample for electrolysis on the outside. The stack and the tube were fully immersed in pure water to remove excess water attached to the surface of the stack and the tube. After 1 minute, the ratio (%) of the area of ​​the portion where the ion exchange membrane (170 mm square) and the electrode sample for electrolysis were in close contact was measured.

[0437] The electrode for electrolysis of the present embodiment is not particularly limited, but preferably has a porous structure from the perspective of obtaining good handling properties, having good adhesion to a separator such as an ion exchange membrane or a microporous membrane, a deteriorated electrode, and a power supply body that is not coated with a catalyst, and preventing the retention of gas generated during electrolysis, and the porosity or void ratio thereof is 5 to 90% or less. The porosity is more preferably 10 to 80% or less, and further preferably 20 to 75%.

[0438] It should be noted that the porosity refers to the ratio of the openings per unit volume. The openings are calculated in various ways, depending on whether the openings are considered up to the submicron level or only considered to be visible to the eye. In this embodiment, the volume V is calculated from the values ​​of the gauge thickness, width, and length of the electrode, and the weight W is actually measured, thereby calculating the porosity A by the following formula.

[0439] A=(1-(W / (V×ρ))×100

[0440] 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 adjustment of the opening ratio can be appropriately adjusted by the following methods: if it is punched metal, change the area of ​​the metal punched per unit area; if it is a metal plate mesh, change the values ​​of SW (short diameter), LW (long diameter), and feed; if it is a mesh, change the wire diameter and mesh count of the metal fiber; if it is electroforming, change the pattern of the photoresist used; if it is a non-woven fabric, change the metal fiber diameter and fiber density; if it is a foamed metal, change the mold used to form the gap; and so on.

[0441] Regarding the electrode for electrolysis 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 further preferably 6.5 mm or less. It should be noted that the specific measurement method is as described in the Examples.

[0442] [Method (A)]

[0443] Under the conditions of temperature 23±2°C and relative humidity 30±5%, a sample of a laminated ion exchange membrane and the above-mentioned electrolytic electrode was wound and fixed on the curved surface of a vinyl chloride core material with an outer diameter of Φ32mm. After standing for 6 hours, the electrolytic electrode was separated and placed on a horizontal plate. The vertical height L of both ends of the electrolytic electrode was measured. 1 and L 2 , and take their average value as the measured value.

[0444] 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 a ventilation volume 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 24kPa·s / m or less. A large ventilation resistance means that air is difficult to flow, which refers to a high density state. 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, so there is a tendency to cause damage to the diaphragm, and also cause a voltage increase and membrane damage on the cathode side, and membrane damage on the anode side. In this embodiment, in order to prevent these undesirable conditions, it is preferred that the ventilation resistance is less than 24kPa·s / m. From the same aspects as above, it is more preferably less than 0.19kPa·s / m, further preferably less than 0.15kPa·s / m, and further preferably less than 0.07kPa·s / m.

[0445] 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 brine supply 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.

[0446] On the other hand, when the ventilation resistance is low, the area of ​​the electrode is reduced, so there is a tendency that the electrolysis area is reduced and the electrolysis performance (voltage, etc.) deteriorates. When the ventilation resistance is zero, since no electrolysis electrode is provided, the power supply functions as an electrode, and there is a tendency that the electrolysis performance (voltage, etc.) deteriorates significantly. From this aspect, the preferred lower limit value specified as the ventilation resistance 1 is not particularly limited, and is preferably greater than 0 kPa·s / m, more preferably 0.0001 kPa·s / m or more, and further preferably 0.001 kPa·s / m or more.

[0447] It should be noted that, regarding the ventilation resistance 1, from the perspective of its measurement method, it is sometimes impossible to obtain sufficient measurement accuracy when it is below 0.07 kPa·s / m. 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 the measurement condition under which 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.

[0448] The specific method for measuring ventilation resistance 1 and 2 is as described in the examples.

[0449] The ventilation resistances 1 and 2 can be within the above ranges by, for example, appropriately adjusting the aperture ratio, electrode thickness, etc., which will be described later. More specifically, for example, if the thickness is the same, the ventilation resistances 1 and 2 tend to decrease when the aperture ratio is increased, and the ventilation resistances 1 and 2 tend to increase when the aperture ratio is decreased.

[0450] Hereinafter, one form of the electrode for electrolysis according to the present embodiment will be described.

[0451] The electrolysis electrode of the present embodiment preferably includes an electrolysis electrode substrate and a catalyst layer. The catalyst layer may be composed of a plurality of layers or a single layer structure as described below.

[0452] like Figure 1 As shown in FIG. 1 , the electrolysis electrode 100 of the present 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. Thus, the catalytic activity and durability of the electrode are easily improved. It should be noted that the first layer 20 may be laminated only on one surface of the electrolysis electrode substrate 10.

[0453] 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. In addition, the second layer 30 may be laminated on only one surface of the first layer 20.

[0454] (Electrode substrate for electrolysis)

[0455] The electrolysis electrode substrate 10 is not particularly limited, and for example, nickel, nickel alloy, stainless steel, and valve metals represented by titanium can be used. Preferably, it contains at least one element selected from nickel (Ni) and titanium (Ti). That is, the electrolysis electrode substrate preferably contains at least one element selected from nickel (Ni) and titanium (Ti).

[0456] When stainless steel is used in a high-concentration alkaline aqueous solution, a substrate composed of nickel (Ni) is preferably used as the electrolytic electrode substrate, taking into account the elution of iron and chromium and the fact that the conductivity of stainless steel is about 1 / 10 of that of nickel.

[0457] 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.

[0458] 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, metal plate mesh, metal porous foil formed by electroforming, and the so-called woven mesh made by weaving metal wires can be used. Among them, punching metal or metal plate mesh is preferred. It should be noted that electroforming refers to the technology of combining photoengraving and electroplating to make a metal film with a precise pattern. It is a method of forming a pattern on a substrate using a photoresist, and electroplating is performed on the part not protected by the resist to obtain a metal film.

[0459] The shape of the electrolysis electrode substrate has suitable specifications according to the distance between the anode and the cathode in the electrolytic cell. Although not particularly limited, in the case where the anode and the cathode have a limited distance, a metal plate mesh or a punched metal shape can be used. In the case of a so-called zero-gap electrolytic cell where the ion exchange membrane and the electrode are in contact, a woven mesh woven from fine wires, a foamed metal, a metal nonwoven fabric, a metal plate mesh, a punched metal, a metal porous foil, etc. can be used.

[0460] Examples of the electrolytic electrode substrate 10 include metal foil, metal mesh, metal nonwoven fabric, punched metal, expanded metal, and foamed metal.

[0461] 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.

[0462] In addition, as described above, the thickness of the electrolysis electrode substrate 10 is preferably 300 μm or less, more preferably 205 μm or less, further preferably 155 μm or less, still more preferably 135 μm or less, further preferably 125 μm or less, further preferably 120 μm or less, further preferably 100 μm or less, and further preferably 50 μm or less from the perspective of handling and economic efficiency. The lower limit is not particularly limited, and is, for example, 1 μm, preferably 5 μm, and more preferably 15 μm.

[0463] In the electrolysis electrode substrate, it is preferred to anneal the electrolysis electrode substrate in an oxidizing atmosphere to relieve residual stress during processing. In addition, in order to improve the adhesion with the catalyst layer coated on the surface, it is preferred to form unevenness on the surface of the electrolysis electrode substrate using a steel grid, an alumina grid, etc., and then increase the surface area by acid treatment. It is preferred to perform plating treatment using the same element as the substrate to increase the surface area.

[0464] In order to make the first layer 20 adhere closely to the surface of the electrolysis electrode substrate 10, it is preferred to perform a treatment to increase the surface area. Examples of the treatment to increase the surface area include: sandblasting using cut wire, steel grid, alumina grid, etc.; acid treatment using sulfuric acid or hydrochloric acid; plating treatment using the same element as the substrate; etc. 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.

[0465] Next, a description will be given of a case where the electrode for electrolysis of the present embodiment is used as an anode for electrolysis of sodium chloride.

[0466] (First floor)

[0467] Figure 1 In the embodiment, the first layer 20 as the catalyst layer contains at least one oxide selected from ruthenium oxide, iridium oxide and titanium oxide. Examples of ruthenium oxide include RuO 2 As iridium oxide, IrO 2 As titanium oxide, TiO 2 The first layer 20 preferably includes two oxides of ruthenium oxide and titanium oxide, or three oxides of ruthenium oxide, iridium oxide, and titanium oxide. Thus, the first layer 20 becomes a more stable layer, and the adhesion with the second layer 30 is further improved.

[0468] When the first layer 20 contains both ruthenium oxide and titanium oxide, the 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. When the composition ratio of the two oxides is within this range, the electrolytic electrode 100 exhibits excellent durability.

[0469] When the first layer 20 contains three oxides of ruthenium oxide, iridium oxide, and titanium oxide, the 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 the ruthenium oxide contained in the first layer 20. In addition, the 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 the ruthenium oxide contained in the first layer 20. By setting the composition ratio of the three oxides to this range, the electrolysis electrode 100 exhibits excellent durability.

[0470] 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.

[0471] In addition to the above composition, as long as it contains at least one oxide of ruthenium oxide, iridium oxide and titanium oxide, various compositions can be used. For example, an oxide coating containing ruthenium, iridium, tantalum, niobium, titanium, tin, cobalt, manganese, platinum, etc., which is called DSA (registered trademark), can also be used as the first layer 20.

[0472] 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 including three oxides and a layer including two oxides. The thickness of the first layer 20 is preferably 0.05 to 10 μm, more preferably 0.1 to 8 μm.

[0473] (Second floor)

[0474] The second layer 30 preferably contains ruthenium and titanium. This can further reduce the overvoltage of chlorine immediately after electrolysis.

[0475] 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.

[0476] 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 is preferably 0.05 to 3 μm.

[0477] Next, a description will be given of a case where the electrode for electrolysis of the present embodiment is used as a cathode for electrolysis of sodium chloride.

[0478] (First floor)

[0479] The components of the first layer 20 serving as the catalyst layer 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.

[0480] 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 contains at least one platinum group metal of platinum, palladium, rhodium, ruthenium, and iridium.

[0481] As the platinum group metal, platinum is preferably contained.

[0482] As the platinum group metal oxide, ruthenium oxide is preferably contained.

[0483] As the platinum group metal hydroxide, ruthenium hydroxide is preferably contained.

[0484] As the platinum group metal alloy, an alloy containing platinum, nickel, iron, or cobalt is preferred.

[0485] Furthermore, it is preferable to contain an oxide or hydroxide of a lanthanoid element as the second component as necessary. Thereby, the electrode for electrolysis 100 exhibits excellent durability.

[0486] 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.

[0487] Furthermore, if necessary, it is preferred to contain an oxide or hydroxide of a transition metal as a third component.

[0488] By adding the third component, the electrolysis electrode 100 exhibits more excellent durability and the electrolysis voltage can be reduced.

[0489] Examples of preferred combinations include only ruthenium, ruthenium + nickel, ruthenium + cerium, ruthenium + lanthanum, ruthenium + lanthanum + platinum, ruthenium + lanthanum + palladium, ruthenium + praseodymium, ruthenium + praseodymium + platinum, ruthenium + praseodymium + platinum, 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, alloy of platinum and nickel, alloy of platinum and cobalt, alloy of platinum and iron, etc.

[0490] When no platinum group metal, platinum group metal oxide, platinum group metal hydroxide or alloy containing a platinum group metal is contained, the main component of the catalyst is preferably nickel element.

[0491] Preferably, it contains at least one of nickel metal, oxide, and hydroxide.

[0492] A transition metal may be added as a second component. The second component to be added preferably contains at least one element selected from titanium, tin, molybdenum, cobalt, manganese, iron, sulfur, zinc, copper, and carbon.

[0493] Preferred combinations include nickel+tin, nickel+titanium, nickel+molybdenum, and nickel+cobalt.

[0494] 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.

[0495] As the intermediate layer, an intermediate layer having affinity with both the first layer 20 and the electrolysis electrode substrate 10 is preferred. As the intermediate layer, nickel oxide, platinum group metal, platinum group metal oxide, platinum group metal hydroxide is preferred. As the intermediate layer, it can be formed by applying a solution containing components forming the intermediate layer and firing it, or by heat treating the substrate at a temperature of 300 to 600° C. in an air atmosphere to form a surface oxide layer. In addition, it can also be formed by known methods such as thermal spraying and ion plating.

[0496] (Second floor)

[0497] The components of the first layer 30 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. It may contain at least one of platinum group metals, platinum group metal oxides, platinum group metal hydroxides, and alloys containing platinum group metals, or it may not contain. As examples of preferred combinations of elements contained in the second layer, there are combinations listed in the first layer, etc. The combination of the first layer and the second layer can be a combination with the same composition but different composition ratios, or a combination of different compositions.

[0498] As the thickness of the catalyst layer, the thickness of the formed catalyst layer and the intermediate layer combined is preferably 0.01 μm to 20 μm. If it is 0.01 μm or more, it can fully function as a catalyst. If it is 20 μm or less, there is less detachment from the substrate, and a strong catalyst layer can be formed. It is more preferably 0.05 μm to 15 μm. It is more preferably 0.1 μm to 10 μm. It is further preferably 0.2 μm to 8 μm.

[0499] As the thickness of the electrode, that is, the total thickness of the electrode substrate for electrolysis and the catalyst layer, from the aspect of the handleability of the electrode, it is preferably 315 μm or less, more preferably 220 μm or less, more preferably 170 μm or less, and even more preferably 150 μm or less, particularly preferably 145 μm or less, more preferably 140 μm or less, further preferably 138 μm or less, and even more 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 even more preferably 65 μm or less. The lower limit is not particularly limited, preferably 1 μm or more, from a practical aspect, 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., minimum display 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.

[0500] (Method for producing an electrolytic electrode)

[0501] Next, one embodiment of a method for producing the electrode for electrolysis 100 will be described in detail.

[0502] In this 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. Among them, thermal decomposition method, plating method, and ion plating method are preferred because they can form a catalyst layer while suppressing the deformation of the electrolysis electrode substrate. Further, from the perspective of productivity, plating method and thermal decomposition method are further preferred. This manufacturing method of the present embodiment can achieve high productivity of the electrolysis electrode 100. Specifically, in the case of thermal decomposition method, a catalyst layer is formed on the electrolysis electrode substrate by a coating step of coating 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. Depending on the type of metal used, the type of salt, the atmosphere for thermal decomposition, etc., the decomposition product will be different, but in an oxidizing atmosphere, many metals have a tendency to easily form oxides. In the industrial production process of electrodes for electrolysis, thermal decomposition usually takes place in air, and in most cases metal oxides or metal hydroxides are formed.

[0503] (Formation of the First Layer of the Anode)

[0504] (Coating process)

[0505] The first layer 20 is obtained by applying a solution (first coating liquid) in which at least one metal salt of ruthenium, iridium and titanium is dissolved to the electrolytic electrode substrate, and then thermally decomposing (firing) the solution in the presence of oxygen. The content of ruthenium, iridium and titanium in the first coating liquid is substantially equal to that of the first layer 20.

[0506] The metal salt may be any of chloride salts, nitrates, sulfates, metal alkoxides, and other salts. The solvent of the first coating solution may be selected according to the type of metal salt, and water and alcohols such as butanol may be used. As the solvent, water or a mixed solvent of water and alcohols is preferred. The total metal concentration in the first coating solution in which the metal salt is dissolved is not particularly limited, but is preferably in the range of 10 to 150 g / L in consideration of the thickness of the coating formed by one coating.

[0507] As a method for applying the first coating liquid to the electrolytic electrode substrate 10, there are used an immersion method in which the electrolytic 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, an electrostatic coating method in which the electrolytic electrode substrate 10 and the first coating liquid are sprayed with opposite charges, etc. Among them, the roller method or the electrostatic coating method is preferred because of its excellent industrial productivity.

[0508] (Drying process, thermal decomposition process)

[0509] After the first coating liquid is applied to the electrolysis electrode substrate 100, 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, pre-firing can be performed at 100 to 350°C as needed. The drying, pre-firing and thermal decomposition temperatures can be appropriately selected according to the composition of the first coating liquid or the type of solvent. It is preferred that the time for each thermal decomposition is long, and from the perspective of electrode productivity, it is preferably 3 to 60 minutes, and more preferably 5 to 20 minutes.

[0510] The above-mentioned cycle of coating, drying and thermal decomposition is repeated to form the coating (first layer 20) to a predetermined thickness. After the first layer 20 is formed, it can be further heated after further calcination for a long time as needed to further improve the stability of the first layer 20.

[0511] (Formation of the Second Layer of the Anode)

[0512] The second layer 30 is formed as necessary, 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.

[0513] (Formation of the First Layer of the Cathode by Thermal Decomposition Method)

[0514] (Coating process)

[0515] The first layer 20 is obtained by applying a solution (first coating solution) in which various combinations of metal salts are dissolved 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 .

[0516] The metal salt may be any of chloride salts, nitrates, sulfates, metal alkoxides, and other salts. The solvent of the first coating solution may be selected according to the type of metal salt, and water and alcohols such as ethanol and butanol may be used. As the solvent, water or a mixed solvent of water and alcohols is preferred. The total metal concentration in the first coating solution in which the metal salt is dissolved is not particularly limited, but is preferably in the range of 10 to 150 g / L in consideration of the thickness of the coating formed by one coating.

[0517] As a method for applying the first coating liquid to the electrolytic electrode substrate 10, there are used an immersion method in which the electrolytic 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, an electrostatic coating method in which the electrolytic electrode substrate 10 and the first coating liquid are sprayed with opposite charges, etc. Among them, the roller method or the electrostatic coating method is preferred because of its excellent industrial productivity.

[0518] (Drying process, thermal decomposition process)

[0519] 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, pre-firing can be performed at 100 to 350°C as needed. The drying, pre-firing and thermal decomposition temperatures can be appropriately selected according to the composition of the first coating liquid or the type of solvent. It is preferred that the time for each thermal decomposition is long, and from the perspective of electrode productivity, it is preferably 3 to 60 minutes, and more preferably 5 to 20 minutes.

[0520] The coating, drying and thermal decomposition cycles are repeated to form the coating (first layer 20) to a predetermined thickness. After the first layer 20 is formed, it can be further heated at 350°C to 650°C for 1 minute to 90 minutes after further sintering for a long time as needed to further improve the stability of the first layer 20.

[0521] (Formation of the middle layer)

[0522] The intermediate layer is formed as needed, for example, by applying a solution (second coating solution) containing a palladium compound or a platinum compound to the substrate and then thermally decomposing it in the presence of oxygen. Alternatively, the nickel oxide intermediate layer may be formed on the substrate surface by heating the substrate at a temperature of 300°C to 580°C for 1 to 60 minutes without applying the solution.

[0523] (Formation of the First Layer of the Cathode by Ion Plating)

[0524] The first layer 20 can also be formed by ion plating.

[0525] As an example, a method can be cited in which a substrate is fixed in a chamber and an electron beam is irradiated on a metal ruthenium target. The evaporated metal ruthenium particles are positively charged in the plasma in the chamber and deposited on the negatively charged substrate. The plasma atmosphere is argon and oxygen, and ruthenium is deposited on the substrate in the form of ruthenium oxide.

[0526] (Formation of the First Layer of the Cathode by Plating)

[0527] The first layer 20 can also be formed by a plating method.

[0528] 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.

[0529] (Formation of the First Layer of the Cathode by Thermal Spraying)

[0530] The first layer 20 can also be formed by thermal spraying.

[0531] 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.

[0532] 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, so it can be used as a membrane-integrated electrode, and the cathode and anode need not be replaced when the electrode is updated, thereby greatly improving the operating efficiency.

[0533] The electrode for electrolysis of this embodiment forms a laminate with a separator such as an ion exchange membrane or a microporous membrane, and the separator and the electrode are integrated, thereby making the electrolysis performance the same as that of a new product or further improving it. The separator is not particularly limited as long as it can form a laminate with the electrode, and is described in detail below.

[0534] [Ion exchange membrane]

[0535] The ion exchange membrane comprises: a membrane body comprising a hydrocarbon polymer or a fluorine-containing polymer having an ion exchange group; and a coating layer provided on at least one surface of the membrane body. In addition, 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 / g. 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.

[0536] The above-mentioned ion exchange membrane has an ion exchange group (-SO 3 - The sulfonic acid layer having a sulfonic acid group (hereinafter also referred to as a "sulfonic acid group") and the ion exchange group (-CO 2 - The group represented by (hereinafter also referred to as "carboxylic acid group") is any one of the carboxylic acid layers. From the viewpoint of strength and dimensional stability, it is preferred to further have a reinforcing core material.

[0537] The inorganic particles and the binder will be described in detail below in the section of description of the coating layer.

[0538] Figure 2 The ion exchange membrane 1 includes a membrane body 10 made of a hydrocarbon polymer or a fluorine-containing polymer having an ion exchange group, and coating layers 11 a and 11 b formed on both surfaces of the membrane body 10 .

[0539] In the ion exchange membrane 1, the membrane body 10 includes the sulfonic acid layer 3 and the carboxylic acid layer 2, and the strength and dimensional stability are enhanced by the reinforcing core material 4. Since the ion exchange membrane 1 includes the sulfonic acid layer 3 and the carboxylic acid layer 2, it is suitable for use as an ion exchange membrane.

[0540] 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.

[0541] (Membrane body)

[0542] First, the membrane main body 10 constituting the ion exchange membrane 1 will be described.

[0543] The membrane body 10 has a function of selectively permeating cations and may include a hydrocarbon polymer or a fluorine-containing polymer having an ion exchange group. The structure and material thereof are not particularly limited, and an appropriate structure or material may be appropriately selected.

[0544] The hydrocarbon polymer or fluorine-containing polymer having an ion exchange group 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, etc. Specifically, for example, a polymer having a main chain composed of a fluorinated hydrocarbon, having a group (ion exchange group precursor) that can be converted into an ion exchange group by hydrolysis, etc. as a side chain, and capable of melt processing (hereinafter referred to as "fluorine-containing polymer (a)" depending on the situation) 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, thereby obtaining the membrane body 10.

[0545] 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.

[0546] As the monomer of the first group, for example, fluorinated vinyl compounds can be cited. As the fluorinated vinyl compounds, for example, fluorinated vinyl, tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, trifluoroethylene, trifluorochloroethylene, perfluoroalkyl vinyl ether, etc. can be cited. 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.

[0547] As the monomer of the second group, for example, there can be mentioned a vinyl compound having a functional group that can be converted into a carboxylic acid type ion exchange group (carboxylic acid group). As the vinyl compound having a functional group that can be converted into a carboxylic acid group, for example, there can be mentioned CF 2 =CF(OCF 2 CYF) s -O(CZF) t-COOR (herein, s represents an integer of 0 to 2, t represents an integer of 1 to 12, Y and Z each independently represent F or CF 3 , R represents a lower alkyl group. The lower alkyl group is, for example, an alkyl group having 1 to 3 carbon atoms. ).

[0548] Among these, CF is preferred. 2 =CF(OCF 2 CYF) n -O(CF 2 ) m -COOR. Here, n represents an integer of 0 to 2, m represents an integer of 1 to 4, and Y represents F or CF 3 , R represents CH 3 , C 2 H 5 , or C 3 H 7 .

[0549] It should be noted that when using an ion exchange membrane as a cation exchange membrane for alkaline electrolysis, it is preferred to use at least a perfluoro compound as a monomer, but 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.

[0550] As the monomer of the second group, among the above, the monomers shown below are more preferable.

[0551] CF 2 =CFOCF 2 -CF(CF 3 )OCF 2 COOCH 3 ,

[0552] CF 2 =CFOCF 2 CF(CF 3 )O(CF 2 ) 2 COOCH 3 ,

[0553] CF 2 =CF[OCF 2 -CF(CF 3 )] 2 O(CF 2 ) 2 COOCH 3 ,

[0554] CF 2 =CFOCF 2 CF(CF 3)O(CF 2 ) 3 COOCH 3 ,

[0555] CF 2 =CFO(CF 2 ) 2 COOCH 3 ,

[0556] CF 2 =CFO(CF 2 ) 3 COOCH 3 .

[0557] As the monomer of the third group, for example, there can be mentioned a vinyl compound having a functional group that can be converted into a sulfone type ion exchange group (sulfonic acid group). As the vinyl compound having a functional group that can be converted into a sulfonic acid group, for example, CF 2 =CFO-X-CF 2 -SO 2 A monomer represented by F (here, X represents a perfluoroalkylene group). Specific examples thereof include the following monomers.

[0558] CF 2 =CFOCF 2 CF 2 SO 2 F.

[0559] CF 2 =CFOCF 2 CF(CF 3 )OCF 2 CF 2 SO 2 F.

[0560] CF 2 =CFOCF 2 CF(CF 3 )OCF 2 CF 2 CF 2 SO 2 F.

[0561] CF 2 =CF(CF 2 ) 2 SO 2 F.

[0562] CF 2 =CFO[CF 2 CF(CF 3 )O] 2 CF 2 CF2 SO 2 F.

[0563] CF 2 =CFOCF 2 CF(CF 2 OCF 3 )OCF 2 CF 2 SO 2 F.

[0564] Among these, CF is more preferred. 2 =CFOCF 2 CF(CF 3 )OCF 2 CF 2 CF 2 SO 2 F, and CF 2 =CFOCF 2 CF(CF 3 )OCF 2 CF 2 SO 2 F.

[0565] The copolymers obtained from these monomers can be produced by the polymerization methods developed for homopolymerization and copolymerization of ethylene fluoride, especially the general polymerization methods used for tetrafluoroethylene. For example, in the non-aqueous method, the polymerization reaction can be carried out at a temperature of 0 to 200° C. and a pressure of 0.1 to 20 MPa in the presence of a free radical polymerization initiator such as a perfluorocarbon peroxide or an azo compound using an inert solvent such as a perfluorocarbon or a chlorofluorocarbon.

[0566] 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 group to be given 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 the second group 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 monomers of the above-mentioned first group and the third group 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 monomers of the above-mentioned first group, the second group and the third group for copolymerization. In this case, copolymers consisting of the above-mentioned first group and the second group and copolymers consisting of the above-mentioned first group and the third group are polymerized respectively, and then mixed, thereby the target fluorine-containing polymer can also be obtained. 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, as long as the ratio of monomers selected from the above-mentioned second group and the third group is increased.

[0567] The total ion exchange capacity of the fluorine-containing 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. Here, the total ion exchange capacity refers to the equivalent of exchange groups per unit weight of dry resin, and can be measured by neutralization titration or the like.

[0568] The sulfonic acid layer 3 comprising a fluorine-containing polymer having a sulfonic acid group and the carboxylic acid layer 2 comprising a fluorine-containing polymer having a carboxylic acid group are stacked in the membrane body 10 of the ion exchange membrane 1. By forming the membrane body 10 with such a layer structure, the selective permeability of cations such as sodium ions can be further improved.

[0569] When the ion exchange membrane 1 is disposed in an electrolytic cell, it is usually disposed 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.

[0570] The sulfonic acid layer 3 is preferably made of a material with low 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.

[0571] The carboxylic acid layer 2 preferably has high anion exclusion properties even when the membrane thickness is thin. The anion exclusion property here refers to the property of preventing anions from entering or passing through the ion exchange membrane 1. In order to improve the anion exclusion property, it is effective to arrange a carboxylic acid layer having a smaller ion exchange capacity than the sulfonic acid layer.

[0572] As the fluorine-containing polymer used for the sulfonic acid layer 3, for example, CF 2 =CFOCF 2 CF(CF 3 )OCF 2 CF 2 SO 2 F is suitable as the polymer obtained by using the monomer of group 3.

[0573] As the fluorine-containing polymer used for the carboxylic acid layer 2, for example, CF 2 =CFOCF 2 CF(CF 2 )O(CF 2 ) 2 COOCH 3 The polymers obtained as monomers of group 2 are suitable.

[0574] (Coating layer)

[0575] The ion exchange membrane has a coating layer on at least one surface of the membrane body. Figure 2As shown, in the ion exchange membrane 1, coating layers 11a and 11b are formed on both surfaces of a membrane body 10, respectively.

[0576] The coating layer contains inorganic particles and a binder.

[0577] The average particle size of the inorganic particles is more preferably 0.90 μm or more. When the average particle size of the inorganic particles is 0.90 μm or more, not only the durability to gas adhesion but also to impurities is extremely improved. That is, by increasing the average particle size of the inorganic particles and satisfying the above-mentioned specific surface area value, a particularly significant effect can be obtained. Since such average particle size and specific surface area are satisfied, irregular inorganic particles are preferred. Inorganic particles obtained by melting and inorganic particles obtained by crushing raw ore can be used. Preferably, inorganic particles obtained by crushing raw ore can be suitably used.

[0578] 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.

[0579] Here, the average particle size can be measured using a particle size distribution meter ("SALD2200" manufactured by Shimadzu Corporation).

[0580] The shape of the inorganic particles is preferably irregular. The resistance to impurities will be further improved. In addition, the particle size distribution of the inorganic particles is preferably wide.

[0581] The inorganic particles preferably contain at least one inorganic substance selected from the group consisting of oxides of Group IV elements, nitrides of Group IV elements, and carbides of Group IV elements. In terms of durability, particles of zirconium oxide are more preferred.

[0582] The inorganic particles are preferably inorganic particles produced by pulverizing raw ore of inorganic particles, or spherical particles having a uniform particle size obtained by melting and refining raw ore of inorganic particles.

[0583] As the raw ore crushing 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 cited. In addition, preferably after crushing, cleaning is performed, and at this moment, as a cleaning method, acid treatment is preferably performed. Thus, impurities such as iron attached to the surface of inorganic particles can be reduced.

[0584] The coating layer preferably contains a binder. The binder is a component that holds inorganic particles on the surface of the ion exchange membrane to form the coating layer. From the perspective of resistance to electrolyte or electrolysis products, the binder preferably contains a fluorine-containing polymer.

[0585] 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.

[0586] In the coating layer, the content of the inorganic particles 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.

[0587] 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 shape on the surface, the distribution density of the coating layer is preferably 2 0.5~2mg.

[0588] The method for forming the coating layer is not particularly limited, and a known method can be used. For example, there can be mentioned a method in which inorganic particles are dispersed in a solution containing a binder and the obtained coating solution is applied by spraying or the like.

[0589] (Reinforced core material)

[0590] The ion exchange membrane preferably has a reinforcing core material disposed inside the membrane body.

[0591] The reinforcing core material is a component for reinforcing the strength and dimensional stability of the ion exchange membrane. By arranging the reinforcing core material inside the membrane body, the expansion and contraction of the ion exchange membrane can be controlled to a desired range. The ion exchange membrane will not expand or contract to a greater extent than necessary during electrolysis, and can maintain excellent dimensional stability for a long time.

[0592] The composition of the reinforcing core material is not particularly limited, for example, a filament called a reinforcing filament can be spun to form it. The reinforcing filament mentioned here is a member constituting the reinforcing core material, and refers to a filament that can impart the desired dimensional stability and mechanical strength to the ion exchange membrane and can stably exist in the ion exchange membrane. By using the reinforcing core material formed by spinning the reinforcing filament, it is possible to impart more excellent dimensional stability and mechanical strength to the ion exchange membrane.

[0593] The materials of the reinforcing core material and the reinforcing yarn used for the reinforcing core material 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 preferred.

[0594] 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, trifluorochloroethylene-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.

[0595] The diameter of the reinforcing yarn used to strengthen the core material is not particularly limited, and is preferably 20 to 300 deniers, and more preferably 50 to 250 deniers. The weaving density (the number of wefts per unit length) is preferably 5 to 50 strands / inch. There is no particular limitation on the method of reinforcing the core material, and for example, woven fabric, non-woven fabric, knitted fabric, etc. are used, and woven fabric is preferred. In addition, regarding the thickness of the woven fabric, a woven fabric of preferably 30 to 250 μm, and more preferably 30 to 150 μm is used.

[0596] The woven or knitted fabric may be made of monofilament, multifilament or yarn thereof, slit yarn or the like, and may be woven in various ways, such as plain weave, leno weave, knit, groove weave, and crepe-striped thin weave.

[0597] 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 use environment, and the like.

[0598] For example, a reinforcing core material can be arranged along a specified direction of the membrane body, but from the aspect of dimensional stability, it is preferred to arrange the reinforcing core material along a specified first direction, and arrange other reinforcing core materials along a second direction substantially perpendicular to the first direction. By arranging a plurality of reinforcing core materials in a substantially 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 along the longitudinal direction and a reinforcing core material (weft) arranged along the transverse direction into the surface of the membrane body. From the aspects of dimensional stability, mechanical strength and ease of manufacturing, it is more preferred to: make the warp and weft alternately float and sink and beat the weft to form a plain weave; twist two warps while weaving them into the weft; for two or more warps that are respectively aligned, beat the same number of wefts to form a square plain weave; and so on.

[0599] 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 wires, sacrificial wires described later, etc.) are transported 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 wire woven along the MD direction is called MD wire, and the wire woven along the TD direction is called TD wire. Usually, the ion exchange membrane used for electrolysis is mostly rectangular, and the length direction is the MD direction and the width direction is the TD direction. By weaving in a reinforcing core material as an MD wire and a reinforcing core material as a TD wire, it is possible to impart better dimensional stability and mechanical strength in multiple directions.

[0600] The arrangement interval of the reinforcing core material is not particularly limited, and can be appropriately set to an appropriate arrangement in consideration of the desired physical properties of the ion exchange membrane, the use environment, and the like.

[0601] 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. The opening ratio is preferably 30% or more from the perspective of electrochemical properties of the ion exchange membrane, and preferably 90% or less from the perspective of mechanical strength of the ion exchange membrane.

[0602] The opening ratio of the reinforcing core material refers to 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 in the area (A) of any surface of the membrane body. The total surface area (B) through which substances such as ions can pass refers to the total area of ​​the region in the ion exchange membrane where cations, electrolytes, etc. are not blocked by the reinforcing core material, etc. contained in the ion exchange membrane.

[0603] Figure 3 It is a schematic diagram for explaining the opening ratio of the reinforcing core material constituting the ion exchange membrane. Figure 3 A portion of the ion exchange membrane is enlarged to show only the arrangement of the reinforcing core materials 21 and 22 in this region, and other members are omitted from illustration.

[0604] The total area (B) of the area through which substances such as ions can pass can be obtained by subtracting the total area (C) of the reinforcing core material from the area (A) of the region (the region is the region surrounded by the reinforcing core material 21 arranged in the longitudinal direction and the reinforcing core material 22 arranged in the transverse direction, and the area (A) includes the area of ​​the reinforcing core material. That is, the aperture ratio can be obtained by the following formula (I).

[0605] Opening ratio=(B) / (A)=((A)-(C)) / (A)…(I)

[0606] In the reinforcing core material, from the perspective of chemical resistance and heat resistance, a particularly preferred method is a flat yarn or highly oriented monofilament containing PTFE. Specifically, it is more preferred to cut a high-strength porous sheet composed of PTFE into a strip-shaped flat yarn; or to use a highly oriented monofilament composed of PTFE with a denier of 50 to 300 and a weaving density of 10 to 50 strands / inch, and a thickness of 50 to 100 μm. The opening ratio of the ion exchange membrane containing the reinforcing core material is more preferably 60% or more.

[0607] Examples of the shape of the reinforcing yarn include round yarns and ribbon-shaped yarns.

[0608] (Connecting hole)

[0609] The ion exchange membrane preferably has communicating pores inside the membrane body.

[0610] The connecting hole refers to a hole that can become a flow channel for ions and electrolytes generated during electrolysis. In addition, the connecting hole refers to a tubular hole formed inside the membrane body, which is formed by the dissolution of the sacrificial core material (or sacrificial wire) described later. The shape and diameter of the connecting hole can be controlled by selecting the shape and diameter of the sacrificial core material (sacrificial wire).

[0611] By forming the communicating holes in the ion exchange membrane, the mobility of the electrolyte can be ensured during electrolysis. The shape of the communicating holes is not particularly limited, and can be the shape of the sacrificial core material used to form the communicating holes according to the production method described below.

[0612] The connecting holes are preferably formed in a manner that alternately passes through the anode side (sulfonic acid layer side) and the cathode side (carboxylic acid layer side) of the reinforcing core material. With this structure, in the portion where the connecting holes are formed on the cathode side of the reinforcing core material, ions (e.g., sodium ions) transported by the electrolyte that fills the connecting holes can also flow to the cathode side of the reinforcing core material. As a result, the flow of cations is not hindered, thereby further reducing the resistance of the ion exchange membrane.

[0613] 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.

[0614] [Manufacturing method]

[0615] As a preferred method for producing the ion exchange membrane, there can be mentioned a method comprising the following steps (1) to (6).

[0616] (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.

[0617] (2) Step: A step of weaving at least a plurality of reinforcing core materials and sacrificial wires that are soluble in acid or alkali and form continuous pores as necessary to obtain a reinforcing material having sacrificial wires disposed between adjacent reinforcing core materials.

[0618] (3) Step: a step of forming a membrane of the fluorine-containing polymer having an ion exchange group or an ion exchange group precursor capable of becoming an ion exchange group by hydrolysis.

[0619] (4) Step: A step of embedding the reinforcing material in the film as necessary to obtain a film body having the reinforcing material disposed therein.

[0620] Step (5): A step of hydrolyzing the membrane body obtained in step (4) (hydrolysis step).

[0621] Step (6): A step of providing a coating layer on the film body obtained in step (5) (coating step).

[0622] Hereinafter, each step will be described in detail.

[0623] (1) Process: Process for producing fluorine-containing polymer

[0624] In step (1), a fluorine-containing polymer is produced using the raw material monomers described in Groups 1 to 3. In order to control the ion exchange capacity of the fluorine-containing polymer, the mixing ratio of the raw material monomers may be adjusted in the production of the fluorine-containing polymer forming each layer.

[0625] (2) Process: Manufacturing process of reinforcement materials

[0626] The reinforcing material refers to a woven fabric woven from reinforcing yarns. By embedding the reinforcing material in the membrane, a reinforcing core material is formed. When an ion exchange membrane having interconnecting holes is made, the sacrificial yarn is also woven into the reinforcing material. The mixed weaving amount of the sacrificial yarn at this time is preferably 10 to 80% by mass of the entire reinforcing material, more preferably 30 to 70% by mass. By weaving in the sacrificial yarn, the dislocation of the reinforcing core material can also be prevented.

[0627] The sacrificial fiber is soluble in the membrane manufacturing process or electrolytic environment, and rayon, polyethylene terephthalate (PET), cellulose, polyamide, etc. are used. In addition, polyvinyl alcohol, etc. having a thickness of 20 to 50 deniers and composed of monofilaments or multifilaments is also preferred.

[0628] It should be noted that in the 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.

[0629] (3) Process: Membrane process

[0630] In step (3), the fluorine-containing polymer obtained in step (1) is formed into a film by 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.

[0631] As a method of forming a membrane, for example, the following method can be mentioned.

[0632] A method of separately forming a film of a fluorinated polymer having a carboxylic acid group and a fluorinated polymer having a sulfonic acid group.

[0633] 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.

[0634] 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.

[0635] (4) Step: Step of obtaining the membrane body

[0636] In step (4), the reinforcing material obtained in step (2) is embedded in the interior of the film obtained in step (3), thereby obtaining a film body having the reinforcing material inside.

[0637] As a preferred method for forming the membrane body, there can be cited the following: (i) a fluorine-containing polymer having a carboxylic acid precursor (e.g., a carboxylate functional group) located on the cathode side (the layer formed by it is hereinafter referred to as the first layer) and a fluorine-containing polymer having a sulfonic acid precursor (e.g., a sulfonyl fluoride functional group) (the layer formed by it is hereinafter referred to as the second layer) are formed into a film by co-extrusion, and a heating source and a vacuum source are used as needed to stack them in the order of a reinforcing material, a second layer / first layer composite film, and a heat-resistant release paper having air permeability on a flat plate or cylinder having a large number of pores on the surface, and the reinforcing material is stacked on each polymer. (ii) a method in which the fluorine-containing polymer (third layer) having a sulfonic acid group precursor is preliminarily formed into a film separately from the second layer / first layer composite film, and a heating source and a vacuum source are used as needed to laminate the third layer film, a reinforcing core material, and a composite film consisting of the second layer / first layer 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 the pressure at the melting temperature of each polymer, and the composite film is integrated at the same time.

[0638] Here, coextrusion of the first layer and the second layer helps to improve the bonding strength of the interface.

[0639] In addition, the method of integrating under reduced pressure has the characteristic that the thickness of the third layer on the reinforcing material is increased compared to the pressure pressing method. In addition, since the reinforcing material is fixed to the inner surface of the membrane body, it has the performance of being able to fully maintain the mechanical strength of the ion exchange membrane.

[0640] It should be noted that the lamination variation described here is an example, and a suitable lamination pattern (eg, combination of layers, etc.) may be appropriately selected in consideration of the desired layer structure or physical properties of the film body, and then co-extrusion may be performed.

[0641] 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 may 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 may be used instead of the second layer.

[0642] 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.

[0643] When the fourth layer is an ion exchange membrane, the first and fourth layers can be formed into a coextruded film, and the third and second layers can be formed separately from them and laminated using the above method; or the three layers of the first layer / fourth layer / second layer can be formed into a film by coextrusion at one time.

[0644] In this case, the direction in which the extruded film flows is the MD direction. In this way, a film body including a fluorine-containing polymer having an ion exchange group can be formed on the reinforcing material.

[0645] In addition, the ion exchange membrane preferably has a protruding part, i.e., a convex portion, consisting of a fluoropolymer having a sulfonic acid group on the surface side consisting of the sulfonic acid layer. As a method for forming such a convex portion, it is not particularly limited, and a known method for forming a convex portion on a resin surface can be adopted. Specifically, for example, a method for embossing the surface of a membrane body can be cited. For example, when the above-mentioned composite membrane and a reinforcing material etc. are integrated, the above-mentioned convex portion can be formed by using a release paper that has been embossed in advance. In the case of 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.

[0646] (5) Hydrolysis process

[0647] In the step (5), the membrane body obtained in the step (4) is hydrolyzed to convert the ion exchange group precursor into the ion exchange group (hydrolysis step).

[0648] In addition, in step (5), the sacrificial silk contained in the membrane body can be dissolved and removed by acid or alkali, thereby forming dissolution holes in the membrane body. It should be noted that the sacrificial silk can also remain in the connecting holes and is not completely dissolved and removed. In addition, the sacrificial silk remaining in the connecting holes can be dissolved and removed by the electrolyte when the ion exchange membrane is supplied to electrolysis.

[0649] The sacrificial wire is soluble in acid or alkali in the electrolytic environment during the manufacturing process of the ion exchange membrane, and the sacrificial wire is eluted to form a communication hole at the location.

[0650] 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.

[0651] The mixed solution preferably contains 2.5 to 4.0 N KOH and 25 to 35 mass % DMSO.

[0652] The hydrolysis temperature is preferably 70 to 100°C. The higher the temperature, the greater the apparent thickness. The more preferred temperature is 75 to 100°C.

[0653] The hydrolysis time is preferably 10 to 120 minutes. The longer the time, the greater the apparent thickness. More preferably, it is 20 to 120 minutes.

[0654] Here, the step of dissolving the sacrificial wire 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.

[0655] 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.

[0656] First, the reinforcing material is prepared by weaving the reinforcing wire 52 constituting the reinforcing core material in the ion exchange membrane and the sacrificial wire 504a for forming the communicating pores 504 in the ion exchange membrane. The communicating pores 504 are formed by dissolving the sacrificial wire 504a in step (5).

[0657] According to the above method, the weaving method of the reinforcing yarn 52 and the sacrificial yarn 504a can be adjusted according to the arrangement of the reinforcing core material and the communicating holes in the membrane body of the ion exchange membrane, so it is simple.

[0658] exist Figure 4 In (a), a plain woven reinforcing material is illustrated in which reinforcing yarns 52 and sacrificial yarns 504a are woven in both the longitudinal and transverse directions on the paper surface. However, the arrangement of the reinforcing yarns 52 and sacrificial yarns 504a in the reinforcing material can be changed as needed.

[0659] (6) Coating process

[0660] In step (6), a coating liquid containing inorganic particles obtained by pulverizing 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.

[0661] 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.

[0662] The adhesive is dissolved in a solution mixed with water and ethanol. It should be noted that the preferred volume ratio of water to ethanol is 10:1 to 1:10, more preferably 5:1 to 1:5, and further preferably 2:1 to 1:2. Inorganic particles are dispersed in the thus obtained solution using a ball mill to obtain a coating solution. At this time, the average particle size of the particles can also be adjusted by adjusting the time and rotation speed during the dispersion. It should be noted that the preferred mixing amounts of the inorganic particles and the adhesive are as described above.

[0663] The concentrations of the inorganic particles and the binder in the coating liquid are not particularly limited, but a dilute coating liquid is preferred so that the coating can be uniformly applied to the surface of the ion exchange membrane.

[0664] In addition, when dispersing the inorganic particles, a surfactant may be added to the dispersion. As the surfactant, a nonionic surfactant is preferred, and examples thereof include HS-210, NS-210, P-210, and E-212 manufactured by NOF Corporation.

[0665] 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.

[0666] [Microporous membrane]

[0667] As described above, the microporous membrane of the present embodiment is not particularly limited as long as it can form a laminate with the electrolytic electrode, and various microporous membranes can be applied.

[0668] The porosity of the microporous film 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.

[0669] Porosity = (1-(weight of the film in a dry state) / (weight calculated from the volume calculated from the thickness, width, and length of the film and the density of the film raw material)) × 100

[0670] The average pore size of the microporous membrane of the present embodiment is not particularly limited, and can be, for example, 0.01 μm to 10 μm, preferably 0.05 μm to 5 μm. The average pore size can be obtained by, for example, cutting the membrane perpendicularly to the thickness direction and observing the cross section by FE-SEM. The diameter of the observed pores is measured at about 100 points and averaged.

[0671] The thickness of the microporous membrane of the present embodiment is not particularly limited, and may be, for example, 10 μm to 1000 μm, and preferably 50 μm to 600 μm. The thickness can be measured using, for example, a micrometer (manufactured by Mitutoyo Corporation).

[0672] Specific examples of the microporous membrane include Zirfon Perl UTP 500 manufactured by Agfa (also referred to as Zirfon membrane in the present embodiment), microporous membranes described in International Publication No. 2013-183584, International Publication No. 2016-203701, and the like.

[0673] [laminated body]

[0674] The laminate of this embodiment comprises the electrode for electrolysis of this embodiment and a diaphragm or a power supply body in contact with the electrode for electrolysis. Due to such a structure, the laminate of this embodiment can improve the working efficiency when the electrode in the electrolytic cell is updated, and further can show excellent electrolysis performance after the update.

[0675] That is, according to the laminate of the present embodiment, when the electrode is renewed, the electrode can be renewed by the same simple operation as the renewal of the separator without complicated operations such as peeling off the electrode fixed to the electrolytic cell, so the working efficiency is greatly improved.

[0676] In addition, according to the laminate of the present invention, the performance of the new product can be maintained or the electrolysis performance can be improved. In addition, in the case where the new electrolysis unit is only provided with a power supply (i.e., an electrode without a catalyst layer is provided), the electrolysis electrode of this embodiment can function as an electrode simply by pasting it on the power supply, so the catalyst coating can be greatly reduced or completely eliminated.

[0677] The laminate of the present embodiment can be stored in a state (in a roll or the like) wound around a tube made of polyvinyl chloride, for example, and can be transported to a customer, and thus can be handled very easily.

[0678] In addition, as the power supply body in this embodiment, various substrates described later, such as a deteriorated electrode (that is, an existing electrode) or an electrode not coated with a catalyst, can be applied.

[0679] In the laminate of the present embodiment, the force applied per unit mass / 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 1.6 N / (mg·cm 2), and more preferably less than 1.5 N / (mg·cm 2 ), and more preferably 1.2 N / mg·cm 2 Below, more preferably 1.20 N / mg·cm 2 More preferably, it is 1.1 N / mg·cm 2 Below, more preferably 1.10 N / mg·cm 2 Below, particularly preferably 1.0 N / mg·cm 2 Below, especially preferably 1.00 N / mg·cm 2 the following.

[0680] [Wound body]

[0681] The wound body of the present embodiment includes the electrode for electrolysis of the present embodiment, or the laminate of the present embodiment. That is, the wound body of the present embodiment is formed by winding the electrode for electrolysis of the present embodiment, or the laminate of the present embodiment. As in the wound body of the present embodiment, the electrode for electrolysis of the present embodiment, or the laminate of the present embodiment is wound to reduce the size, thereby further improving the handling properties.

[0682] [Electrolyzer]

[0683] The electrolytic cell of the present embodiment includes the electrolysis electrode of the present embodiment. Hereinafter, an embodiment of the electrolytic cell will be described in detail by taking the case of electrolyzing salt using an ion exchange membrane as a diaphragm as an example.

[0684] [Electrolysis unit]

[0685] Figure 5 is a cross-sectional view of the electrolysis unit 1.

[0686] The electrolytic unit 1 includes an anode chamber 10, a cathode chamber 20, a partition wall 30 disposed between the anode chamber 10 and the cathode chamber 20, an anode 11 disposed in the anode chamber 10, and a cathode 21 disposed in the cathode chamber 20. If necessary, a reverse current absorber 18 disposed 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 disposed in the cathode chamber 20, and a reverse current absorber 18 disposed in the cathode chamber 20, and the reverse current absorber 18 is as follows: Fig. 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 collector 23, a support 24 supporting the collector, and a metal elastic body 22. The metal elastic body 22 is arranged between the collector 23 and the cathode 21. The support 24 is arranged between the collector 23 and the partition wall 30. The collector 23 is electrically connected to the cathode 21 through the metal elastic body 22. The partition wall 30 is electrically connected to the collector 23 through the support 24. Therefore, the partition wall 30, the support 24, the 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 through the 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. In addition, the electrical connection method may be as follows: the partition wall 30 and the support body 24 are directly mounted, the support body 24 and the collector 23 are directly mounted, the collector 23 and the metal elastic body 22 are directly mounted, and the cathode 21 is stacked on the metal elastic body 22. As a method of directly mounting these components to each other, welding, etc. can be cited. In addition, the reverse current absorber 18, the cathode 21, and the collector 23 can also be collectively referred to as the cathode structure 40.

[0687] Figure 6 It is a cross-sectional view of two adjacent electrolytic units 1 in the electrolytic cell 4 . Figure 7 An electrolytic cell 4 is shown. Figure 8 4 shows the process of assembling the electrolytic cell 4. Figure 6 As shown, the electrolytic unit 1, the cation exchange membrane 2, and the electrolytic unit 1 are arranged in series. The ion exchange membrane 2 is arranged between the anode chamber of one electrolytic unit 1 and the cathode chamber of the other electrolytic unit 1 in the two adjacent electrolytic units in the electrolytic cell. That is, the anode chamber 10 of the electrolytic unit 1 and the cathode chamber 20 of the adjacent electrolytic 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 ion exchange membranes 2 interposed therebetween and connecting them with a pressurizer 5 .

[0688] 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. The current during electrolysis flows from the anode terminal 7 side to the cathode terminal 6 via the anode and cathode of each electrolytic cell 1. It should be noted that an electrolytic cell (anode terminal cell) having only an anode chamber and an electrolytic cell (cathode terminal cell) having only a cathode chamber may also be configured at both ends of the connected electrolytic cell 1. In this case, the anode terminal 7 is connected to the anode terminal cell configured at one end thereof, and the cathode terminal 6 is connected to the cathode terminal cell configured at the other end.

[0689] When the electrolysis of salt water is performed, salt water 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 salt water 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. Along with the electrolysis of the salt water, chlorine gas is generated on the anode 11 side, and sodium hydroxide (solute) and hydrogen gas are generated on the cathode 21 side.

[0690] (Anode chamber)

[0691] The anode chamber 10 has an anode 11 or an anode power supply 11. When the electrode for electrolysis of the present embodiment is inserted into the anode side, 11 functions as an anode power supply. When the electrode for electrolysis of the present embodiment is not inserted into the anode side, 11 functions as an anode. In addition, the anode chamber 10 preferably has: an anode side electrolyte supply unit for supplying electrolyte to the anode chamber 10; a baffle plate arranged above the anode side electrolyte supply unit and arranged approximately parallel to or obliquely to the partition wall 30; and an anode side gas-liquid separation unit arranged above the baffle plate and separating gas from the electrolyte mixed with gas.

[0692] (anode)

[0693] 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 so-called DSA (registered trademark) can be used as the anode 11. DSA refers to an electrode of a titanium base material whose surface is coated with oxides containing ruthenium, iridium, and titanium as components.

[0694] As the shape, any of punched metal, nonwoven fabric, foamed metal, expanded metal, porous metal foil formed by electroforming, so-called woven mesh produced by weaving metal wires, and the like can be used.

[0695] (Anode power supply)

[0696] When the electrode for electrolysis of the present embodiment is inserted into the anode side, an anode power supply 11 is provided in 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 without catalyst coating can be used. In addition, DSA with a reduced catalyst coating thickness can also be used. In addition, a used anode can also be used.

[0697] As the shape, any of punched metal, nonwoven fabric, foamed metal, expanded metal, porous metal foil formed by electroforming, so-called woven mesh produced by weaving metal wires, and the like can be used.

[0698] (Anode side electrolyte supply unit)

[0699] 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 tube) 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.

[0700] (Gas-liquid separation section on the anode side)

[0701] The anode-side gas-liquid separator is preferably disposed above the baffle. In electrolysis, the anode-side gas-liquid separator has the function of separating generated gas such as chlorine and 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 refers to Figure 5 The electrolysis unit 1 is in a downward direction.

[0702] 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, the pressure inside the electrolysis unit 1 will vibrate, 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 be separated into electrolyte and gas. As a result, vibration during electrolysis can be prevented.

[0703] (Baffle)

[0704] The baffle is preferably arranged above the electrolyte supply part 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 setting the baffle, the electrolyte (brine, etc.) can be circulated internally in the anode chamber 10 to make its concentration uniform. In order to produce internal circulation, the baffle is preferably arranged in a manner to separate 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 the electrolysis proceeds, the electrolyte concentration (brine concentration) decreases, and chlorine and other generated gases are generated. As a result, a gas-liquid specific gravity difference 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, and the concentration distribution of the electrolyte in the anode chamber 10 can be made more uniform.

[0705] It should be noted that although it is not shown in Figure 5 , but a current collector may be separately provided inside the anode chamber 10. The current collector 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.

[0706] (Separation wall)

[0707] 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 and the cathode chamber 20. As the partition wall 30, a material known as a separator plate for electrolysis can be used, for example, a partition wall formed by welding a nickel plate on the cathode side and a titanium plate on the anode side.

[0708] (Cathode chamber)

[0709] Regarding the cathode chamber 20, when the electrode for electrolysis of the present embodiment is inserted into the cathode side, 21 functions as a cathode power supply body, and when the electrode for electrolysis 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 body 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 the parts constituting the anode chamber 10.

[0710] (cathode)

[0711] When the electrode for electrolysis 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 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 required. In addition, the cathode 21 may be subjected to reduction treatment as required. It should be noted that as the substrate of the cathode 21, nickel, nickel alloy, or a substrate obtained by plating iron or stainless steel with nickel may also be used.

[0712] As the shape, any of punched metal, nonwoven fabric, foamed metal, expanded metal, porous metal foil formed by electroforming, so-called woven mesh produced by weaving metal wires, and the like can be used.

[0713] (Cathode power supply)

[0714] When the electrolysis electrode of the present embodiment is inserted into the cathode side, a cathode power supply 21 is provided in the frame of the cathode chamber 20. The cathode power supply 21 may be coated with a catalyst component. The catalyst component may 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 metal may be cited. As the formation method of the catalyst layer, plating, alloy plating, dispersion composite plating, CVD, PVD, thermal decomposition and spraying may be cited. These methods may also be combined. The catalyst layer may have a plurality of layers and a plurality of elements as required. It should be noted that as the base material of the cathode current supply body 21, nickel, a nickel alloy, or a base material obtained by plating iron or stainless steel with nickel may be used.

[0715] Alternatively, the power supply body 21 may be made of nickel, a nickel alloy, or iron or stainless steel plated with nickel without being coated with a catalyst.

[0716] As the shape, any of punched metal, nonwoven fabric, foamed metal, expanded metal, porous metal foil formed by electroforming, so-called woven mesh produced by weaving metal wires, and the like can be used.

[0717] (Reverse current absorption layer)

[0718] As the material of the reverse current absorption layer, a material having a redox potential lower than the redox potential of the element used for the cathode catalyst layer can be selected, for example, nickel, iron, etc.

[0719] (Current Collector)

[0720] The cathode chamber 20 preferably includes a current collector 23 . This improves the current collection effect. In the present embodiment, the current collector 23 is preferably a porous plate, and is disposed substantially parallel to the surface of the cathode 21 .

[0721] The collector 23 is preferably made of a conductive metal such as nickel, iron, copper, silver, or titanium. The collector 23 may also be a mixture, alloy, or composite oxide of these metals. It should be noted that the shape of the collector 23 may be any shape as long as it functions as a collector, and may be a plate or mesh.

[0722] (Metallic Elastomer)

[0723] 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, and the distance between each anode 11 and each cathode 21 is shortened, so that the voltage applied to the plurality of electrolytic cells 1 connected in series as a whole can be reduced. By reducing the voltage, the power consumption can be reduced. In addition, by providing the metal elastic body 22, when the laminate including the electrolytic electrode of the present invention is provided in the electrolytic cell, the pressing pressure generated by the metal elastic body 22 can be used to stably maintain the electrolytic electrode in a fixed position.

[0724] As the metal elastic body 22, a spring member such as a spiral spring, a coil, a cushioning pad, etc. can be used. As the metal elastic body 22, a suitable metal elastomer can be appropriately used in consideration of the stress of pressing the ion exchange membrane, etc. The metal elastomer 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, etc., it is preferred to arrange the metal elastomer 22 between the collector 23 of the cathode chamber 20 and the cathode 21. In addition, the metal elastomer 23 is preferably composed of a conductive metal such as nickel, iron, copper, silver, titanium, etc.

[0725] (Support)

[0726] The cathode chamber 20 preferably includes a support 24 that electrically connects the current collector 23 and the partition wall 30. This allows current to flow efficiently.

[0727] The support 24 is preferably made of a conductive metal such as nickel, iron, copper, silver, titanium, etc. In addition, the shape of the support 24 can be any shape as long as it can support the collector 23, and can be a rod, a plate, or a mesh. The support 24 is, for example, in the form of a plate. A plurality of supports 24 are arranged between the partition wall 30 and the collector 23. A plurality of supports 24 are arranged in such a way that their respective faces are parallel to each other. The support 24 is arranged substantially perpendicular to the partition wall 30 and the collector 23.

[0728] (Anode side gasket, cathode side gasket)

[0729] 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 units 1 are connected in series via the ion exchange membrane 2 .

[0730] Gasket refers to a component that seals between an ion exchange membrane and an electrolytic unit. As a specific example of a gasket, a rubber sheet having a picture frame shape with an opening in the center can be cited. For the gasket, it is required to be resistant to corrosive electrolytes or generated gases, and can be used for a long time. Therefore, from the aspects of chemical resistance and hardness, a vulcanized product or a peroxide cross-linked product of ethylene propylene diene rubber (EPDM rubber) and diethylene propylene diene rubber (EPM rubber) is usually used as a gasket. In addition, as required, a gasket coated with a fluorine resin such as polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) in the area in contact with the liquid (liquid contact portion) can also be used. These gaskets are not particularly limited in shape as long as they have openings so as not to hinder the flow of the electrolyte. For example, a picture frame-shaped gasket is pasted with an adhesive or the like along 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. In addition, for example, when two electrolytic cells 1 are connected via an ion exchange membrane 2 (see Figure 6 ), each electrolytic unit 1 with a gasket attached thereto can be fastened through the ion exchange membrane 2. Thus, leakage of the electrolyte, alkali metal hydroxide, chlorine, hydrogen, etc. generated by electrolysis to the outside of the electrolytic unit 1 can be suppressed.

[0731] (Ion exchange membrane 2)

[0732] The ion exchange membrane 2 is as described in the above-mentioned section of the ion exchange membrane.

[0733] (Water Electrolysis)

[0734] The electrolytic cell of the present embodiment is an electrolytic cell for water electrolysis, and it has the following structure: the ion exchange membrane in the electrolytic cell for the above-mentioned salt electrolysis is changed to a microporous membrane. In addition, the raw material supplied is water, which is different from the electrolytic cell for the above-mentioned salt electrolysis. Regarding other structures, the electrolytic cell for water electrolysis can also adopt the same structure as the electrolytic cell for 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 etc. can be cited. In addition, the anode coating is suitable for the catalyst coating for oxygen generation. As an example of catalyst coating, metals, oxides, hydroxides, etc. of platinum group metals and transition metals can be cited. For example, elements such as platinum, iridium, palladium, ruthenium, nickel, cobalt, and iron can be used.

[0735] <Second Embodiment>

[0736] Here, refer to Figures 22 to 42 The second embodiment of the present invention will be described in detail.

[0737] [laminated body]

[0738] A laminate according to a second embodiment (hereinafter referred to as “the present embodiment” in the section “the second embodiment”) comprises an electrode for electrolysis, and a diaphragm or a power supply body in contact with the electrode for electrolysis, wherein a force per unit mass / unit area of ​​the electrode for electrolysis applied to the diaphragm or the power supply body 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 renewed, and can also exhibit excellent electrolytic performance after renewal.

[0739] That is, according to the laminate of this embodiment, when the electrode is renewed, the electrode can be renewed by the same simple operation as the renewal of the separator without complicated operations such as peeling off the existing electrode fixed to the electrolytic cell, so the working efficiency is greatly improved.

[0740] Furthermore, the laminate of the present invention can maintain the performance of a new product or improve the electrolytic performance. Therefore, the electrodes fixed to the existing new electrolytic unit and functioning as anodes and cathodes only need to function as power supply bodies, and the catalyst coating can be greatly reduced or completely eliminated.

[0741] The laminate of the present embodiment can be stored in a state (in a roll or the like) wound around a tube made of polyvinyl chloride, for example, and can be transported to a customer, and thus can be handled very easily.

[0742] In addition, as the power supply body in this embodiment, various substrates described later, such as a deteriorated electrode (that is, an existing electrode) and an electrode not coated with a catalyst, can be applied.

[0743] In addition, the laminate of the present embodiment may partially have a fixing portion as long as it has the above-mentioned structure. That is, when the laminate of the present 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 electrolysis electrode is less than 1.5 N / mg·cm 2 That's it.

[0744] [Electrode for electrolysis]

[0745] The electrolytic electrode of the present embodiment has a force of less than 1.5 N / mg·cm per unit mass·unit area in order to obtain good handling properties and good adhesion to a separator such as an ion exchange membrane or a microporous membrane, a power supply (a degraded electrode or an electrode not coated with a catalyst), etc. 2 , preferably 1.2N / mg·cm 2 Below, more preferably 1.20 N / mg·cm2 More preferably, it is 1.1 N / mg·cm 2 Below, more preferably 1.10 N / mg·cm 2 Less than 1.0 N / mg·cm 2 Below, more preferably 1.00 N / mg·cm 2 the following.

[0746] From the perspective of further improving electrolytic performance, it is preferred that the concentration of 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 (e.g., 1.5 m × 2.5 m) environments, 0.2 N / (mg·cm 2 )above.

[0747] The above-mentioned applied force can be within the above-mentioned range by appropriately adjusting the aperture ratio, electrode thickness, arithmetic mean surface roughness, etc., which will be described later. More specifically, for example, if the aperture ratio is increased, the applied force tends to decrease, and if the aperture ratio is decreased, the applied force tends to increase.

[0748] In addition, the mass per unit area is preferably 48 mg / cm from the perspectives of good handling, good adhesion to ion exchange membranes, microporous membranes, and other separators, deteriorated electrodes, and non-catalyst-coated power supplies, and economic efficiency. 2 Below, more 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.

[0749] The mass per unit area can be within the above range by, for example, appropriately adjusting the aperture ratio, the thickness of the electrode, etc. More specifically, for example, if the thickness is the same, the mass per unit area tends to decrease when the aperture ratio is increased, and the mass per unit area tends to increase when the aperture ratio is decreased.

[0750] 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 either value is less than 1.5 N / mg·cm 2 .

[0751] [Method (i)]

[0752] A nickel plate (thickness 1.2 mm, 200 mm square) obtained by sandblasting with alumina of 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 of a perfluorocarbon polymer having an ion exchange group, and an electrode sample (130 mm square) are sequentially stacked, and the stack is fully immersed in pure water, and then the excess water attached to the surface of the stack is removed to obtain a sample for measurement. It should be noted that the arithmetic mean surface roughness (Ra) of the nickel plate after sandblasting is 0.5 to 0.8 μm. The specific calculation method of the arithmetic mean surface roughness (Ra) is as described in the examples.

[0753] Under the conditions of temperature 23±2°C and relative humidity 30±5%, use a tension-compression tester to raise only the electrode sample in the test sample in the vertical direction at 10 mm / min, and measure the load when the electrode sample is raised in the vertical direction by 10 mm. Perform this measurement three times and calculate the average value.

[0754] 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 / unit area (1) (N / mg·cm 2 ).

[0755] The force (1) applied per unit mass / unit area obtained by the method (i) 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 1.20 N / mg·cm 2 Below, more preferably 1.1 N / mg·cm 2 Less than 1.10 N / mg·cm 2 Less than 1.0 N / mg·cm2 Below, more preferably 1.00 N / mg·cm 2 In addition, from the perspective of further improving the electrolytic performance, the applied force (1) is preferably greater than 0.005 N / (mg·cm 2 ), more preferably 0.08N / (mg·cm 2 ) or more, more preferably 0.1 N / (mg·cm 2 ) or more, and further preferably 0.14 N / (mg·cm 2 ) or more, and more preferably 0.2 N / (mg·cm 2 )above.

[0756] If the electrode for electrolysis of the present embodiment satisfies the applied force (1), it can be used in an integrated manner (i.e., as a laminate) with a separator such as an ion exchange membrane or a microporous membrane or a power supply, so that when the electrode is updated, it is not necessary to replace the cathode and anode fixed to the electrolysis unit by welding or the like, thereby greatly improving the operating efficiency. In addition, by using the electrode for electrolysis of the present embodiment as a laminate integrated with an ion exchange membrane or a microporous membrane or a power supply, the electrolysis performance can be made the same as that of a new product or further improved.

[0757] When shipping a new electrolysis unit, in the prior art, the electrode fixed to the electrolysis unit is coated with a catalyst, but by combining the electrode for electrolysis of the present embodiment with the electrode that has not been coated with a catalyst, it can be used as an electrode, so that the manufacturing process or the amount of catalyst for the catalyst coating can be greatly reduced or completely eliminated. The electrode of the prior art in which the catalyst coating is greatly reduced or completely eliminated can be electrically connected to the electrode for electrolysis of the present embodiment and function as a power supply for circulating current.

[0758] [Method (ii)]

[0759] A nickel plate (1.2 mm thick, 200 mm square, the same nickel plate as in the above method (i)) obtained by sandblasting with alumina of grain number 320 and an electrode sample (130 mm square) were sequentially stacked, and the stack was fully immersed in pure water, and the excess water attached to the surface of the stack was removed to obtain a sample for measurement. Under the conditions of temperature 23±2°C and relative humidity 30±5%, only the electrode sample in the sample for measurement was raised in the vertical direction at 10 mm / min using a tensile compression tester, and the load when the electrode sample was raised in the vertical direction by 10 mm was measured. This measurement was carried out 3 times, and the average value was calculated.

[0760] 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 overlapping portion with the nickel plate to calculate the adhesive force per unit mass / unit area (2) (N / mg·cm 2 ).

[0761] The force (2) applied per unit mass / unit area obtained by method (ii) 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 1.20 N / mg·cm 2 Below, more preferably 1.1 N / mg·cm 2 Less than 1.10 N / mg·cm 2 Less than 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 0.1 N / (mg·cm 2 ) or more, and further preferably 0.14 N / (mg·cm 2 )above.

[0762] If the electrolysis electrode of the present embodiment satisfies the applied force (2), it can be stored in a state of being wound around a tube made of polyvinyl chloride (in a roll, etc.), and transported to a customer, etc., and handling becomes very easy. In addition, by pasting the electrolysis electrode of the present embodiment to a deteriorated existing electrode to form a laminate, the electrolysis performance can be made the same as that of a new product or further improved.

[0763] When the electrode for electrolysis of the present embodiment is an electrode with a wide elastic deformation region, the thickness of the electrode for electrolysis is preferably 315 μm or less, more preferably 220 μm or less, more preferably 170 μm or less, and even more preferably 150 μm or less, particularly preferably 145 μm or less, 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 obtaining better handling properties and better adhesion to diaphragms such as ion exchange membranes or microporous membranes, degraded electrodes, and power supply bodies that are not coated with catalysts. If it is 135 μm or less, good handling properties can be obtained. In addition, from the same aspects as above, it is preferably 130 μm or less, more preferably less than 130 μm, 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 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, in the present embodiment, "wide elastic deformation region" means that the electrolysis electrode is wound into a wound body, and after the wound state is unwound, it is difficult to produce warping from the winding. In addition, the thickness of the electrolysis electrode, when including the catalyst layer described later, refers to the thickness of the electrolysis electrode substrate and the catalyst layer combined.

[0764] The electrode for electrolysis of the present embodiment preferably includes an electrode substrate for electrolysis and a catalyst layer. The thickness (gauge thickness) of the electrode substrate for electrolysis is not particularly limited, and is preferably 300 μm or less, more preferably 205 μm or less, more preferably 155 μm or less, and more preferably 135 μm or less, more preferably 125 μm or less, more preferably 120 μm or less, and more preferably 100 μm or less, and from the perspective of processability and economy, it is more preferably 50 μm or less. The lower limit is not particularly limited, for example, 1 μm, preferably 5 μm, and more preferably 15 μm.

[0765] In the present embodiment, 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, so a liquid with a large surface tension is preferred. As a liquid, the following substances can be cited (the numerical value in the bracket is the surface tension of the liquid at 20°C).

[0766] Hexane (20.44mN / m), acetone (23.30mN / m), methanol (24.00mN / m), ethanol (24.05mN / m), ethylene glycol (50.21mN / m) water (72.76mN / m)

[0767] If the liquid has a large surface tension, the diaphragm and the electrode for electrolysis, or the metal porous plate or the metal plate (electric power source) and the electrode for electrolysis are integrated (formed into a laminate), and the electrode renewal becomes easy. The amount of liquid between the diaphragm and the electrode for electrolysis, or the metal porous plate or the metal plate (electric power source) and the electrode for electrolysis is sufficient to be adhered to each other by surface tension, and the amount of liquid is small, so even if it is mixed into the electrolyte after the electrolysis unit is set in the laminate, it will not affect the electrolysis itself.

[0768] From a practical aspect, as liquid, it is preferred to use a liquid with 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, potassium bicarbonate, 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 to adjust 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 (electricity supply body) and the electrode for electrolysis changes, and the processability can be adjusted. As a surfactant, there is no particular restriction, and any of an ionic surfactant and a nonionic surfactant can be used.

[0769] The electrode for electrolysis of the present embodiment is not particularly limited, but the ratio measured by the following method (2) is preferably 90% or more, more preferably 92% or more, from the perspective of obtaining good handling properties and good adhesion to diaphragms such as ion exchange membranes or microporous membranes, degraded electrodes (electrical conductors), and electrodes (electrical conductors) not coated with catalysts, and further preferably 95% or more from the perspective of facilitating handling under large sizes (e.g., sizes of 1.5 m×2.5 m). The upper limit is 100%.

[0770] [Method (2)]

[0771] The ion exchange membrane (170 mm square) and the electrode sample (130 mm square) were stacked in sequence. Under the conditions of temperature 23±2°C and relative humidity 30±5%, the stack was placed on the curved surface of a polyethylene tube (280 mm outer diameter) in such a way that the electrode sample in the stack was on the outside. The stack and the tube were fully immersed in pure water, and the excess water attached to the surface of the stack and the tube was removed. After 1 minute, the ratio (%) of the area of ​​the part where the ion exchange membrane (170 mm square) and the electrode sample were in close contact was measured.

[0772] The electrode for electrolysis of the present embodiment is not particularly limited, but the ratio measured by the following method (3) is preferably 75% or more, more preferably 80% or more, from the perspective of obtaining good handling properties, good adhesion to diaphragms such as ion exchange membranes or microporous membranes, degraded electrodes (electrical conductors), and electrodes (electrical conductors) not coated with catalysts, and being able to be rolled up appropriately and bent well. Furthermore, from the perspective of facilitating handling under large sizes (e.g., sizes of 1.5 m×2.5 m), it is further preferably 90% or more. The upper limit is 100%.

[0773] [Method (3)]

[0774] The ion exchange membrane (170 mm square) and the electrode sample (130 mm square) were stacked in sequence. Under the conditions of temperature 23±2°C and relative humidity 30±5%, the stack was placed on the curved surface of a polyethylene tube (outer diameter 145 mm) in such a way that the electrode sample in the stack was on the outside. The stack and the tube were fully immersed in pure water, and the excess water attached to the surface of the stack and the tube was removed. After 1 minute, the ratio (%) of the area of ​​the part where the ion exchange membrane (170 mm square) and the electrode sample were in close contact was measured.

[0775] The electrode for electrolysis of the present embodiment is not particularly limited, but preferably has a porous structure from the perspective of obtaining good handling properties, having good adhesion to a separator such as an ion exchange membrane or a microporous membrane, a deteriorated electrode (electrical source), and an electrode (electrical source) not coated with a catalyst, and preventing the retention of gas generated during electrolysis, and the porosity or void ratio thereof is 5 to 90% or less. The porosity is more preferably 10 to 80% or less, and further preferably 20 to 75%.

[0776] It should be noted that the porosity refers to the ratio of the openings per unit volume. The openings are calculated in various ways, depending on whether the openings are considered up to the submicron level or only considered to be visible to the eye. In this embodiment, the volume V is calculated from the values ​​of the gauge thickness, width, and length of the electrode, and the weight W is actually measured, thereby calculating the porosity A by the following formula.

[0777] A=(1-(W / (V×ρ))×100

[0778] 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 adjustment of the opening ratio can be appropriately adjusted by the following methods: if it is punched metal, change the area of ​​the metal punched per unit area; if it is a metal plate mesh, change the values ​​of SW (short diameter), LW (long diameter), and feed; if it is a mesh, change the wire diameter and mesh count of the metal fiber; if it is electroforming, change the pattern of the photoresist used; if it is a non-woven fabric, change the metal fiber diameter and fiber density; if it is a foamed metal, change the mold used to form the gap; and so on.

[0779] Regarding the electrode for electrolysis 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 further preferably 6.5 mm or less. It should be noted that the specific measurement method is as described in the Examples.

[0780] [Method (A)]

[0781] Under the conditions of temperature 23±2°C and relative humidity 30±5%, a sample of a laminated ion exchange membrane and the above-mentioned electrolytic electrode was wound and fixed on the curved surface of a vinyl chloride core material with an outer diameter of Φ32mm. After standing for 6 hours, the electrolytic electrode was separated and placed on a horizontal plate. The vertical height L of both ends of the electrolytic electrode was measured. 1 and L 2 , and take their average value as the measured value.

[0782] 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 a ventilation volume 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 24kPa·s / m or less. A large ventilation resistance means that air is difficult to flow, which refers to a high density state. 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, so there is a tendency to cause damage to the diaphragm, and also cause a voltage increase and membrane damage on the cathode side, and membrane damage on the anode side. In this embodiment, in order to prevent these undesirable conditions, it is preferred that the ventilation resistance is less than 24kPa·s / m. From the same aspects as above, it is more preferably less than 0.19kPa·s / m, further preferably less than 0.15kPa·s / m, and further preferably less than 0.07kPa·s / m.

[0783] 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 brine supply 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.

[0784] On the other hand, when the ventilation resistance is low, the area of ​​the electrode is reduced, so there is a tendency that the electrolysis area is reduced and the electrolysis performance (voltage, etc.) deteriorates. When the ventilation resistance is zero, since no electrolysis electrode is provided, the power supply functions as an electrode, and there is a tendency that the electrolysis performance (voltage, etc.) deteriorates significantly. From this aspect, the preferred lower limit value specified as the ventilation resistance 1 is not particularly limited, and is preferably greater than 0 kPa·s / m, more preferably 0.0001 kPa·s / m or more, and further preferably 0.001 kPa·s / m or more.

[0785] It should be noted that, regarding the ventilation resistance 1, from the perspective of its measurement method, it is sometimes impossible to obtain sufficient measurement accuracy when it is below 0.07 kPa·s / m. 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 the measurement condition under which 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.

[0786] The specific method for measuring ventilation resistance 1 and 2 is as described in the examples.

[0787] The ventilation resistances 1 and 2 can be within the above ranges by, for example, appropriately adjusting the aperture ratio, electrode thickness, etc., which will be described later. More specifically, for example, if the thickness is the same, the ventilation resistances 1 and 2 tend to decrease when the aperture ratio is increased, and the ventilation resistances 1 and 2 tend to increase when the aperture ratio is decreased.

[0788] As described above, the electrolysis electrode of the present embodiment has a force per unit mass / 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, etc.) with a moderate adhesive force, thereby being able to form 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 relatively weak forces such as the surface tension of water that may be contained in diaphragms such as ion exchange membranes or microporous membranes can be bonded to form a laminate, so that a laminate can be easily formed regardless of the scale. In addition, this laminate can show excellent electrolytic performance, so 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 related to the renewal of the component.

[0789] Hereinafter, one form of the electrode for electrolysis according to the present embodiment will be described.

[0790] The electrolysis electrode of the present embodiment preferably includes an electrolysis electrode substrate and a catalyst layer. The catalyst layer may be composed of a plurality of layers or a single layer structure as described below.

[0791] like Fig. 22As shown in FIG. 1 , the electrolysis electrode 100 of the present 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. Thus, the catalytic activity and durability of the electrolysis electrode are easily improved. It should be noted that the first layer 20 may be laminated only on one surface of the electrolysis electrode substrate 10.

[0792] In addition, if Fig. 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. In addition, the second layer 30 may be laminated on only one surface of the first layer 20.

[0793] (Electrode substrate for electrolysis)

[0794] The electrolysis electrode substrate 10 is not particularly limited, and for example, nickel, a nickel alloy, stainless steel, or a valve metal represented by titanium or the like can be used. Preferably, the substrate contains at least one element selected from nickel (Ni) and titanium (Ti).

[0795] When stainless steel is used in a high-concentration alkaline aqueous solution, a substrate composed of nickel (Ni) is preferably used as the electrolytic electrode substrate, taking into account the elution of iron and chromium and the fact that the conductivity of stainless steel is about 1 / 10 of that of nickel.

[0796] 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.

[0797] 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, metal plate mesh, metal porous foil formed by electroforming, and the so-called woven mesh made by weaving metal wires can be used. Among them, punching metal or metal plate mesh is preferred. It should be noted that electroforming refers to the technology of combining photoengraving and electroplating to make a metal film with a precise pattern. It is a method of forming a pattern on a substrate using a photoresist, and electroplating is performed on the part not protected by the resist to obtain a metal film.

[0798] The shape of the electrolysis electrode substrate has suitable specifications according to the distance between the anode and the cathode in the electrolytic cell. Although not particularly limited, in the case where the anode and the cathode have a limited distance, a metal plate mesh or a punched metal shape can be used. In the case of a so-called zero-gap electrolytic cell where the ion exchange membrane and the electrode are in contact, a woven mesh, a metal wire mesh, a foamed metal, a metal nonwoven fabric, a metal plate mesh, a punched metal, a metal porous foil, etc., which are woven from fine wires, can be used.

[0799] Examples of the electrolytic electrode substrate 10 include porous metal foil, metal mesh, metal nonwoven fabric, punched metal, expanded metal, and foamed metal.

[0800] 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.

[0801] In addition, as described above, the thickness of the electrolysis electrode substrate 10 is preferably 300 μm or less, more preferably 205 μm or less, further preferably 155 μm or less, still more preferably 135 μm or less, further preferably 125 μm or less, further preferably 120 μm or less, further preferably 100 μm or less, and further preferably 50 μm or less from the perspective of handling and economic efficiency. The lower limit is not particularly limited, and is, for example, 1 μm, preferably 5 μm, and more preferably 15 μm.

[0802] In the electrolysis electrode substrate, it is preferred to anneal the electrolysis electrode substrate in an oxidizing atmosphere to relieve residual stress during processing. In addition, in order to improve the adhesion with the catalyst layer coated on the surface, it is preferred to form unevenness on the surface of the electrolysis electrode substrate using steel grids, aluminum oxide powder, etc., and then increase the surface area by acid treatment. Alternatively, it is preferred to perform plating treatment using the same element as the substrate to increase the surface area.

[0803] In order to make the first layer 20 adhere closely to the surface of the electrolysis electrode substrate 10, it is preferred to perform a treatment to increase the surface area. Examples of the treatment to increase the surface area include: sandblasting using cut wire, steel grid, alumina grid, etc.; acid treatment using sulfuric acid or hydrochloric acid; plating treatment using the same element as the substrate; etc. 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.

[0804] Next, a description will be given of a case where the electrode for electrolysis of the present embodiment is used as an anode for electrolysis of sodium chloride.

[0805] (First floor)

[0806] Fig. 22 In the embodiment, the first layer 20 as the catalyst layer contains at least one oxide selected from ruthenium oxide, iridium oxide and titanium oxide. Examples of ruthenium oxide include RuO 2 As iridium oxide, IrO 2 As titanium oxide, TiO 2The first layer 20 preferably includes two oxides of ruthenium oxide and titanium oxide, or three oxides of ruthenium oxide, iridium oxide, and titanium oxide. Thus, the first layer 20 becomes a more stable layer, and the adhesion with the second layer 30 is further improved.

[0807] When the first layer 20 contains both ruthenium oxide and titanium oxide, the 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. When the composition ratio of the two oxides is within this range, the electrolytic electrode 100 exhibits excellent durability.

[0808] When the first layer 20 contains three oxides of ruthenium oxide, iridium oxide, and titanium oxide, the 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 the ruthenium oxide contained in the first layer 20. In addition, the 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 the ruthenium oxide contained in the first layer 20. By setting the composition ratio of the three oxides to this range, the electrolysis electrode 100 exhibits excellent durability.

[0809] 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.

[0810] In addition to the above composition, various compositions can be used as long as at least one oxide of ruthenium oxide, iridium oxide and titanium oxide is included. For example, an oxide coating containing ruthenium, iridium, tantalum, niobium, titanium, tin, cobalt, manganese, platinum, etc., which is called DSA (registered trademark), can also be used as the first layer 20.

[0811] 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 including three oxides and a layer including two oxides. The thickness of the first layer 20 is preferably 0.05 to 10 μm, more preferably 0.1 to 8 μm.

[0812] (Second floor)

[0813] The second layer 30 preferably contains ruthenium and titanium. This can further reduce the overvoltage of chlorine immediately after electrolysis.

[0814] 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.

[0815] 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 is preferably 0.05 to 3 μm.

[0816] Next, a description will be given of a case where the electrode for electrolysis of the present embodiment is used as a cathode for electrolysis of sodium chloride.

[0817] (First floor)

[0818] The components of the first layer 20 serving as the catalyst layer 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.

[0819] The alloy 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 of the above.

[0820] 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 contains at least one platinum group metal of platinum, palladium, rhodium, ruthenium, and iridium.

[0821] As the platinum group metal, platinum is preferably contained.

[0822] As the platinum group metal oxide, ruthenium oxide is preferably contained.

[0823] As the platinum group metal hydroxide, ruthenium hydroxide is preferably contained.

[0824] As the platinum group metal alloy, an alloy containing platinum, nickel, iron, or cobalt is preferred.

[0825] Furthermore, it is preferable to contain an oxide or hydroxide of a lanthanoid element as the second component as necessary. Thereby, the electrode for electrolysis 100 exhibits excellent durability.

[0826] 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.

[0827] Furthermore, if necessary, it is preferred to contain an oxide or hydroxide of a transition metal as a third component.

[0828] By adding the third component, the electrolysis electrode 100 exhibits more excellent durability and the electrolysis voltage can be reduced.

[0829] 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.

[0830] In the case of not containing platinum group metals, platinum group metal oxides, platinum group metal hydroxides, and alloys containing platinum group metals, the main component of the catalyst is preferably nickel element.

[0831] It is preferably included at least one of nickel metal, oxide, and hydroxide.

[0832] As the second component, a transition metal can also be added. As the added second component, it is preferably included at least one element of titanium, tin, molybdenum, cobalt, manganese, iron, sulfur, zinc, copper, and carbon.

[0833] Examples of preferred combinations include nickel + tin, nickel + titanium, nickel + molybdenum, nickel + cobalt, etc.

[0834] As needed, an intermediate layer can 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.

[0835] As the intermediate layer, an intermediate layer having affinity with both the first layer 20 and the electrolysis electrode substrate 10 is preferred. As the intermediate layer, nickel oxide, platinum group metals, platinum group metal oxides, and platinum group metal hydroxides are preferred. As the intermediate layer, it can be formed by coating a solution containing the components for forming the intermediate layer and firing, or by subjecting the substrate to heat treatment at a temperature of 300 to 600 °C in an air atmosphere to form a surface oxide layer. In addition to this, it can also be formed by known methods such as thermal spraying and ion plating.

[0836] (Second layer)

[0837] The components of the first layer 30 serving as the catalyst layer 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.

[0838] 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 of the above. Examples of preferred combinations of elements contained in the second layer include the combinations given in the first layer. The combination of the first layer and the second layer may have the same composition but different composition ratios, or may have different compositions.

[0839] As the thickness of the catalyst layer, the thickness of the formed catalyst layer and the intermediate layer combined is preferably 0.01 μm to 20 μm. If it is 0.01 μm or more, it can fully function as a catalyst. If it is 20 μm or less, there is less detachment from the substrate, and a strong catalyst layer can be formed. It is more preferably 0.05 μm to 15 μm. It is more preferably 0.1 μm to 10 μm. It is further preferably 0.2 μm to 8 μm.

[0840] 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, more preferably 170 μm or less, and even more preferably 150 μm or less, particularly preferably 145 μm or less, more preferably 140 μm or less, further preferably 138 μm or less, and even more 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 even more preferably 65 μm or less. The lower limit is not particularly limited, preferably 1 μm or more, from a practical point of view, 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., minimum display 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.

[0841] (Method for producing an electrolytic electrode)

[0842] Next, one embodiment of a method for producing the electrode for electrolysis 100 will be described in detail.

[0843] 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 coating 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 the electrode, thermal decomposition is usually carried out in air, and in most cases metal oxides or metal hydroxides are formed.

[0844] (Formation of the First Layer of the Anode)

[0845] (Coating process)

[0846] The first layer 20 is obtained by applying a solution (first coating liquid) in which at least one metal salt of ruthenium, iridium and titanium is dissolved to the electrolytic electrode substrate, and then thermally decomposing (firing) the solution in the presence of oxygen. The content of ruthenium, iridium and titanium in the first coating liquid is substantially equal to that of the first layer 20.

[0847] The metal salt may be any of chloride salts, nitrates, sulfates, metal alkoxides, and other salts. The solvent of the first coating solution may be selected according to the type of metal salt, and water and alcohols such as butanol may be used. As the solvent, water or a mixed solvent of water and alcohols is preferred. The total metal concentration in the first coating solution in which the metal salt is dissolved is not particularly limited, but is preferably in the range of 10 to 150 g / L in consideration of the thickness of the coating formed by one coating.

[0848] As a method for applying the first coating liquid to the electrolytic electrode substrate 10, there are used an immersion method in which the electrolytic 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, an electrostatic coating method in which the electrolytic electrode substrate 10 and the first coating liquid are sprayed with opposite charges, etc. Among them, the roller method or the electrostatic coating method is preferred because of its excellent industrial productivity.

[0849] (Drying process, thermal decomposition process)

[0850] After the first coating liquid is applied to the electrolysis electrode substrate 100, 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, pre-firing can be performed at 100 to 350°C as needed. The drying, pre-firing and thermal decomposition temperatures can be appropriately selected according to the composition of the first coating liquid or the type of solvent. It is preferred that the time for each thermal decomposition is long, and from the perspective of electrode productivity, it is preferably 3 to 60 minutes, and more preferably 5 to 20 minutes.

[0851] The above-mentioned cycle of coating, drying and thermal decomposition is repeated to form the coating (first layer 20) to a predetermined thickness. After the first layer 20 is formed, it can be further heated after further calcination for a long time as needed to further improve the stability of the first layer 20.

[0852] (Formation of the Second Layer)

[0853] The second layer 30 is formed as necessary, 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.

[0854] (Formation of the First Layer of the Cathode by Thermal Decomposition Method)

[0855] (Coating process)

[0856] The first layer 20 is obtained by applying a solution (first coating solution) in which various combinations of metal salts are dissolved 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 .

[0857] The metal salt may be any of chloride salts, nitrates, sulfates, metal alkoxides, and other salts. The solvent of the first coating solution may be selected according to the type of metal salt, and water and alcohols such as butanol may be used. As the solvent, water or a mixed solvent of water and alcohols is preferred. The total metal concentration in the first coating solution in which the metal salt is dissolved is not particularly limited, but is preferably in the range of 10 to 150 g / L in consideration of the thickness of the coating formed by one coating.

[0858] As a method for applying the first coating liquid to the electrolytic electrode substrate 10, there are used an immersion method in which the electrolytic 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, an electrostatic coating method in which the electrolytic electrode substrate 10 and the first coating liquid are sprayed with opposite charges, etc. Among them, the roller method or the electrostatic coating method is preferred because of its excellent industrial productivity.

[0859] (Drying process, thermal decomposition process)

[0860] 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, pre-firing can be performed at 100 to 350°C as needed. The drying, pre-firing and thermal decomposition temperatures can be appropriately selected according to the composition of the first coating liquid or the type of solvent. It is preferred that the time for each thermal decomposition is long, and from the perspective of electrode productivity, it is preferably 3 to 60 minutes, and more preferably 5 to 20 minutes.

[0861] The above-mentioned cycle of coating, drying and thermal decomposition is repeated to form the coating (first layer 20) to a predetermined thickness. After the first layer 20 is formed, it can be further heated after further calcination for a long time as needed to further improve the stability of the first layer 20.

[0862] (Formation of the middle layer)

[0863] The intermediate layer is formed as needed, for example, by applying a solution (second coating solution) containing a palladium compound or a platinum compound to the substrate and then thermally decomposing it in the presence of oxygen. Alternatively, the nickel oxide intermediate layer may be formed on the substrate surface by simply heating the substrate without applying the solution.

[0864] (Formation of the First Layer of the Cathode by Ion Plating)

[0865] The first layer 20 can also be formed by ion plating.

[0866] As an example, a method can be cited in which a substrate is fixed in a chamber and an electron beam is irradiated on a metal ruthenium target. The evaporated metal ruthenium particles are positively charged in the plasma in the chamber and deposited on the negatively charged substrate. The plasma atmosphere is argon and oxygen, and ruthenium is deposited on the substrate in the form of ruthenium oxide.

[0867] (Formation of the First Layer of the Cathode by Plating)

[0868] The first layer 20 can also be formed by a plating method.

[0869] 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.

[0870] (Formation of the First Layer of the Cathode by Thermal Spraying)

[0871] The first layer 20 can also be formed by thermal spraying.

[0872] 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.

[0873] 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, so it can be used as a membrane-integrated electrode, and the cathode and anode need not be replaced when the electrode is updated, thereby greatly improving the operating efficiency.

[0874] In addition, 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.

[0875] Hereinafter, the ion exchange membrane will be described in detail.

[0876] [Ion exchange membrane]

[0877] The ion exchange membrane comprises: a membrane body comprising a hydrocarbon polymer or a fluorine-containing polymer having an ion exchange group; and a coating layer provided on at least one surface of the membrane body. In addition, 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 / g. 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.

[0878] The perfluorocarbon polymer membrane into which the ion exchange group is introduced is a membrane having an ion exchange group (-SO 3 - The sulfonic acid layer having a sulfonic acid group (hereinafter also referred to as a "sulfonic acid group") and the ion exchange group (-CO 2 - The film is preferably a 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.

[0879] The inorganic particles and the binder will be described in detail below in the section of description of the coating layer.

[0880] Fig.23 The ion exchange membrane 1 includes a membrane body 10 made of a hydrocarbon polymer or a fluorine-containing polymer having an ion exchange group, and coating layers 11 a and 11 b formed on both surfaces of the membrane body 10 .

[0881] In the ion exchange membrane 1, the membrane body 10 has an ion exchange group (-SO 3 - The sulfonic acid layer 3 has a group represented by (hereinafter also referred to as a "sulfonic acid group"), and an ion exchange group derived from a carboxyl group (-CO 2 -The carboxylic acid layer 2 having a group represented by (hereinafter also referred to as "carboxylic acid group") has strength and dimensional stability 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 a cation exchange membrane.

[0882] 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 Fig.23 Example.

[0883] (Membrane body)

[0884] First, the membrane main body 10 constituting the ion exchange membrane 1 will be described.

[0885] The membrane body 10 has a function of selectively permeating cations and may include a hydrocarbon polymer or a fluorine-containing polymer having an ion exchange group. The structure and material thereof are not particularly limited, and an appropriate structure or material may be appropriately selected.

[0886] The hydrocarbon polymer or fluorine-containing polymer having an ion exchange group 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, etc. Specifically, for example, a polymer having a main chain composed of a fluorinated hydrocarbon, having a group (ion exchange group precursor) that can be converted into an ion exchange group by hydrolysis, etc. as a side chain, and capable of melt processing (hereinafter referred to as "fluorine-containing polymer (a)" depending on the situation) 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, thereby obtaining the membrane body 10.

[0887] 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.

[0888] As the monomer of the first group, for example, fluorinated vinyl compounds can be cited. As the fluorinated vinyl compounds, for example, fluorinated vinyl, tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, trifluoroethylene, trifluorochloroethylene, perfluoroalkyl vinyl ether, etc. can be cited. 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.

[0889] As the monomer of the second group, for example, there can be mentioned a vinyl compound having a functional group that can be converted into a carboxylic acid type ion exchange group (carboxylic acid group). As the vinyl compound having a functional group that can be converted into a carboxylic acid group, for example, there can be mentioned CF 2 =CF(OCF 2 CYF) s -O(CZF) t -COOR (herein, s represents an integer of 0 to 2, t represents an integer of 1 to 12, Y and Z each independently represent F or CF 3 , R represents a lower alkyl group. The lower alkyl group is, for example, an alkyl group having 1 to 3 carbon atoms. ).

[0890] Among these, CF is preferred. 2 =CF(OCF 2 CYF) n -O(CF 2 ) m -COOR. Here, n represents an integer of 0 to 2, m represents an integer of 1 to 4, and Y represents F or CF 3 , R represents CH 3 , C 2 H 5 , or C 3 H 7 .

[0891] It should be noted that when using an ion exchange membrane as a cation exchange membrane for alkaline electrolysis, it is preferred to use at least a perfluoro compound as a monomer, but 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.

[0892] As the monomer of the second group, among the above, the monomers shown below are more preferable.

[0893] CF 2 =CFOCF 2 -CF(CF 3 )OCF 2 COOCH 3 ,

[0894] CF 2 =CFOCF 2 CF(CF 3 )O(CF 2 ) 2 COOCH 3 ,

[0895] CF 2 =CF[OCF 2 -CF(CF3 )] 2 O(CF 2 ) 2 COOCH 3 ,

[0896] CF 2 =CFOCF 2 CF(CF 3 )O(CF 2 ) 3 COOCH 3 ,

[0897] CF 2 =CFO(CF 2 ) 2 COOCH 3 ,

[0898] CF 2 =CFO(CF 2 ) 3 COOCH 3 .

[0899] As the monomer of the third group, for example, there can be mentioned a vinyl compound having a functional group that can be converted into a sulfone type ion exchange group (sulfonic acid group). As the vinyl compound having a functional group that can be converted into a sulfonic acid group, for example, CF 2 =CFO-X-CF 2 -SO 2 A monomer represented by F (here, X represents a perfluoroalkylene group). Specific examples thereof include the following monomers.

[0900] CF 2 =CFOCF 2 CF 2 SO 2 F.

[0901] CF 2 =CFOCF 2 CF(CF 3 )OCF 2 CF 2 SO 2 F.

[0902] CF 2 =CFOCF 2 CF(CF 3 )OCF 2 CF 2 CF 2 SO 2 F.

[0903] CF 2 =CF(CF2 ) 2 SO 2 F.

[0904] CF 2 =CFO[CF 2 CF(CF 3 )O] 2 CF 2 CF 2 SO 2 F.

[0905] CF 2 =CFOCF 2 CF(CF 2 OCF 3 )OCF 2 CF 2 SO 2 F.

[0906] Among these, CF is more preferred. 2 =CFOCF 2 CF(CF 3 )OCF 2 CF 2 CF 2 SO 2 F and CF 2 =CFOCF 2 CF(CF 3 )OCF 2 CF 2 SO 2 F.

[0907] The copolymers obtained from these monomers can be produced by the polymerization methods developed for homopolymerization and copolymerization of ethylene fluoride, especially the general polymerization methods used for tetrafluoroethylene. For example, in the non-aqueous method, the polymerization reaction can be carried out at a temperature of 0 to 200° C. and a pressure of 0.1 to 20 MPa in the presence of a free radical polymerization initiator such as a perfluorocarbon peroxide or an azo compound using an inert solvent such as a perfluorocarbon or a chlorofluorocarbon.

[0908] 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 group to be given 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 the second group 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 monomers of the above-mentioned first group and the third group 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 monomers of the above-mentioned first group, the second group and the third group for copolymerization. In this case, copolymers consisting of the above-mentioned first group and the second group and copolymers consisting of the above-mentioned first group and the third group are polymerized respectively, and then mixed, thereby the target fluorine-containing polymer can also be obtained. 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, as long as the ratio of monomers selected from the above-mentioned second group and the third group is increased.

[0909] The total ion exchange capacity of the fluorine-containing 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. Here, the total ion exchange capacity refers to the equivalent of exchange groups per unit weight of dry resin, and can be measured by neutralization titration or the like.

[0910] The sulfonic acid layer 3 comprising a fluorine-containing polymer having a sulfonic acid group and the carboxylic acid layer 2 comprising a fluorine-containing polymer having a carboxylic acid group are stacked in the membrane body 10 of the ion exchange membrane 1. By forming the membrane body 10 with such a layer structure, the selective permeability of cations such as sodium ions can be further improved.

[0911] When the ion exchange membrane 1 is disposed in an electrolytic cell, it is usually disposed 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.

[0912] The sulfonic acid layer 3 is preferably made of a material with low 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.

[0913] The carboxylic acid layer 2 preferably has high anion exclusion properties even when the membrane thickness is thin. The anion exclusion property here refers to the property of preventing anions from entering or passing through the ion exchange membrane 1. In order to improve the anion exclusion property, it is effective to arrange a carboxylic acid layer having a smaller ion exchange capacity than the sulfonic acid layer.

[0914] As the fluorine-containing polymer used for the sulfonic acid layer 3, for example, CF 2 =CFOCF 2 CF(CF3 )OCF 2 CF 2 SO 2 F is suitable as the polymer obtained by using the monomer of group 3.

[0915] As the fluorine-containing polymer used for the carboxylic acid layer 2, for example, CF 2 =CFOCF 2 CF(CF 2 )O(CF 2 ) 2 COOCH 3 The polymers obtained as monomers of group 2 are suitable.

[0916] (Coating layer)

[0917] The ion exchange membrane has a coating layer on at least one surface of the membrane body. Fig.23 As shown, in the ion exchange membrane 1, coating layers 11a and 11b are formed on both surfaces of a membrane body 10, respectively.

[0918] The coating layer contains inorganic particles and a binder.

[0919] The average particle size of the inorganic particles is more preferably 0.90 μm or more. When the average particle size of the inorganic particles is 0.90 μm or more, not only the durability to gas adhesion but also to impurities is extremely improved. That is, by increasing the average particle size of the inorganic particles and satisfying the above-mentioned specific surface area value, a particularly significant effect can be obtained. Since such average particle size and specific surface area are satisfied, irregular inorganic particles are preferred. Inorganic particles obtained by melting and inorganic particles obtained by crushing raw ore can be used. Preferably, inorganic particles obtained by crushing raw ore can be suitably used.

[0920] 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.

[0921] Here, the average particle size can be measured using a particle size distribution meter ("SALD2200" manufactured by Shimadzu Corporation).

[0922] The shape of the inorganic particles is preferably irregular. The resistance to impurities will be further improved. In addition, the particle size distribution of the inorganic particles is preferably wide.

[0923] The inorganic particles preferably contain at least one inorganic substance selected from the group consisting of oxides of Group IV elements, nitrides of Group IV elements, and carbides of Group IV elements. In terms of durability, particles of zirconium oxide are more preferred.

[0924] The inorganic particles are preferably inorganic particles produced by pulverizing raw ore of inorganic particles, or spherical particles having a uniform particle size obtained by melting and refining raw ore of inorganic particles.

[0925] As the raw ore crushing 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 cited. In addition, preferably after crushing, cleaning is performed, and at this moment, as a cleaning method, acid treatment is preferably performed. Thus, impurities such as iron attached to the surface of inorganic particles can be reduced.

[0926] The coating layer preferably contains a binder. The binder is a component that holds inorganic particles on the surface of the ion exchange membrane to form the coating layer. From the perspective of resistance to electrolyte or electrolysis products, the binder preferably contains a fluorine-containing polymer.

[0927] 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.

[0928] In the coating layer, the content of the inorganic particles 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.

[0929] 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 shape on the surface, the distribution density of the coating layer is preferably 2 0.5~2mg.

[0930] The method for forming the coating layer is not particularly limited, and a known method can be used. For example, there can be mentioned a method in which inorganic particles are dispersed in a solution containing a binder and the obtained coating solution is applied by spraying or the like.

[0931] (Reinforced core material)

[0932] The ion exchange membrane preferably has a reinforcing core material disposed inside the membrane body.

[0933] The reinforcing core material is a component for reinforcing the strength and dimensional stability of the ion exchange membrane. By arranging the reinforcing core material inside the membrane body, the expansion and contraction of the ion exchange membrane can be controlled to a desired range. The ion exchange membrane will not expand or contract to a greater extent than necessary during electrolysis, and can maintain excellent dimensional stability for a long time.

[0934] The composition of the reinforcing core material is not particularly limited, for example, a filament called a reinforcing filament can be spun to form it. The reinforcing filament mentioned here is a member constituting the reinforcing core material, and refers to a filament that can impart the desired dimensional stability and mechanical strength to the ion exchange membrane and can stably exist in the ion exchange membrane. By using the reinforcing core material formed by spinning the reinforcing filament, it is possible to impart more excellent dimensional stability and mechanical strength to the ion exchange membrane.

[0935] The materials of the reinforcing core material and the reinforcing yarn used for the reinforcing core material 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 preferred.

[0936] 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, trifluorochloroethylene-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.

[0937] The diameter of the reinforcing yarn used to strengthen the core material is not particularly limited, and is preferably 20 to 300 deniers, and more preferably 50 to 250 deniers. The weaving density (the number of wefts per unit length) is preferably 5 to 50 strands / inch. There is no particular limitation on the method of reinforcing the core material, and for example, woven fabric, non-woven fabric, knitted fabric, etc. are used, and woven fabric is preferred. In addition, regarding the thickness of the woven fabric, a woven fabric of preferably 30 to 250 μm, and more preferably 30 to 150 μm is used.

[0938] The woven or knitted fabric may be made of monofilament, multifilament or yarn thereof, slit yarn or the like, and may be woven in various ways, such as plain weave, leno weave, knit, groove weave, and crepe-striped thin weave.

[0939] 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 use environment, and the like.

[0940] For example, a reinforcing core material can be arranged along a specified direction of the membrane body, but from the aspect of dimensional stability, it is preferred to arrange the reinforcing core material along a specified first direction, and arrange other reinforcing core materials along a second direction substantially perpendicular to the first direction. By arranging a plurality of reinforcing core materials in a substantially 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 along the longitudinal direction and a reinforcing core material (weft) arranged along the transverse direction into the surface of the membrane body. From the aspects of dimensional stability, mechanical strength and ease of manufacturing, it is more preferred to: make the warp and weft alternately float and sink and beat the weft to form a plain weave; twist two warps while weaving them into the weft; for two or more warps that are respectively aligned, beat the same number of wefts to form a square plain weave; and so on.

[0941] 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 wires, sacrificial wires described later, etc.) are transported 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 wire woven along the MD direction is called MD wire, and the wire woven along the TD direction is called TD wire. Usually, the ion exchange membrane used for electrolysis is mostly rectangular, and the length direction is the MD direction and the width direction is the TD direction. By weaving in a reinforcing core material as an MD wire and a reinforcing core material as a TD wire, it is possible to impart better dimensional stability and mechanical strength in multiple directions.

[0942] The arrangement interval of the reinforcing core material is not particularly limited, and can be appropriately set to an appropriate arrangement in consideration of the desired physical properties of the ion exchange membrane, the use environment, and the like.

[0943] 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. The opening ratio is preferably 30% or more from the perspective of electrochemical properties of the ion exchange membrane, and preferably 90% or less from the perspective of mechanical strength of the ion exchange membrane.

[0944] The opening ratio of the reinforcing core material refers to 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 in the area (A) of any surface of the membrane body. The total surface area (B) through which substances such as ions can pass refers to the total area of ​​the region in the ion exchange membrane where cations, electrolytes, etc. are not blocked by the reinforcing core material, etc. contained in the ion exchange membrane.

[0945] Fig.24 It is a schematic diagram for explaining the opening ratio of the reinforcing core material constituting the ion exchange membrane. Fig.24 A portion of the ion exchange membrane is enlarged to show only the arrangement of the reinforcing core materials 21 and 22 in this region, and other members are omitted from illustration.

[0946] The total area (B) of the area through which substances such as ions can pass can be obtained by subtracting the total area (C) of the reinforcing core material from the area (A) of the region (the region is the region surrounded by the reinforcing core material 21 arranged in the longitudinal direction and the reinforcing core material 22 arranged in the transverse direction, and the area (A) includes the area of ​​the reinforcing core material. That is, the aperture ratio can be obtained by the following formula (I).

[0947] Opening ratio=(B) / (A)=((A)-(C)) / (A)…(I)

[0948] In the reinforcing core material, from the perspective of chemical resistance and heat resistance, a particularly preferred method is a flat yarn or highly oriented monofilament containing PTFE. Specifically, it is more preferred to cut a high-strength porous sheet composed of PTFE into a strip-shaped flat yarn; or to use a highly oriented monofilament composed of PTFE with a denier of 50 to 300 and a weaving density of 10 to 50 strands / inch, and a thickness of 50 to 100 μm. The opening ratio of the ion exchange membrane containing the reinforcing core material is more preferably 60% or more.

[0949] Examples of the shape of the reinforcing yarn include round yarns and ribbon-shaped yarns.

[0950] (Connecting hole)

[0951] The ion exchange membrane preferably has communicating pores inside the membrane body.

[0952] The connecting hole refers to a hole that can become a flow channel for ions and electrolytes generated during electrolysis. In addition, the connecting hole refers to a tubular hole formed inside the membrane body, which is formed by dissolving the sacrificial core material (or sacrificial wire) described later. The shape and diameter of the connecting hole can be controlled by selecting the shape and diameter of the sacrificial core material (sacrificial wire).

[0953] By forming the communicating holes in the ion exchange membrane, the mobility of the electrolyte can be ensured during electrolysis. The shape of the communicating holes is not particularly limited, and can be the shape of the sacrificial core material used to form the communicating holes according to the production method described below.

[0954] The connecting holes are preferably formed in a manner that alternately passes through the anode side (sulfonic acid layer side) and the cathode side (carboxylic acid layer side) of the reinforcing core material. With this structure, in the portion where the connecting holes are formed on the cathode side of the reinforcing core material, ions (e.g., sodium ions) transported by the electrolyte that fills the connecting holes can also flow to the cathode side of the reinforcing core material. As a result, the flow of cations is not hindered, thereby further reducing the resistance of the ion exchange membrane.

[0955] 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.

[0956] [Manufacturing method]

[0957] As a preferred method for producing the ion exchange membrane, there can be mentioned a method comprising the following steps (1) to (6).

[0958] (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.

[0959] (2) Step: A step of weaving at least a plurality of reinforcing core materials and sacrificial wires that are soluble in acid or alkali and form continuous pores as necessary to obtain a reinforcing material having sacrificial wires disposed between adjacent reinforcing core materials.

[0960] (3) Step: a step of forming a membrane of the fluorine-containing polymer having an ion exchange group or an ion exchange group precursor capable of becoming an ion exchange group by hydrolysis.

[0961] (4) Step: A step of embedding the reinforcing material in the film as necessary to obtain a film body having the reinforcing material disposed therein.

[0962] Step (5): A step of hydrolyzing the membrane body obtained in step (4) (hydrolysis step).

[0963] Step (6): A step of providing a coating layer on the film body obtained in step (5) (coating step).

[0964] Hereinafter, each step will be described in detail.

[0965] (1) Process: Process for producing fluorine-containing polymer

[0966] In step (1), a fluorine-containing polymer is produced using the raw material monomers described in Groups 1 to 3. In order to control the ion exchange capacity of the fluorine-containing polymer, the mixing ratio of the raw material monomers may be adjusted in the production of the fluorine-containing polymer forming each layer.

[0967] (2) Process: Manufacturing process of reinforcement materials

[0968] The reinforcing material refers to a woven fabric woven from reinforcing yarns. By embedding the reinforcing material in the membrane, a reinforcing core material is formed. When an ion exchange membrane having interconnecting holes is made, the sacrificial yarn is also woven into the reinforcing material. The mixed weaving amount of the sacrificial yarn at this time is preferably 10 to 80% by mass of the entire reinforcing material, more preferably 30 to 70% by mass. By weaving in the sacrificial yarn, the dislocation of the reinforcing core material can also be prevented.

[0969] The sacrificial fiber is soluble in the membrane manufacturing process or electrolytic environment, and rayon, polyethylene terephthalate (PET), cellulose, polyamide, etc. are used. In addition, polyvinyl alcohol, etc. having a thickness of 20 to 50 deniers and composed of monofilaments or multifilaments is also preferred.

[0970] It should be noted that in the 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.

[0971] (3) Process: Membrane process

[0972] In step (3), the fluorine-containing polymer obtained in step (1) is formed into a film by 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.

[0973] As a method of forming a membrane, for example, the following method can be mentioned.

[0974] A method of separately forming a film of a fluorinated polymer having a carboxylic acid group and a fluorinated polymer having a sulfonic acid group.

[0975] 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.

[0976] 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.

[0977] (4) Step: Step of obtaining the membrane body

[0978] In step (4), the reinforcing material obtained in step (2) is embedded in the interior of the film obtained in step (3), thereby obtaining a film body having the reinforcing material inside.

[0979] As a preferred method for forming the membrane body, there can be cited the following: (i) a fluorine-containing polymer having a carboxylic acid precursor (e.g., a carboxylate functional group) located on the cathode side (the layer formed by it is hereinafter referred to as the first layer) and a fluorine-containing polymer having a sulfonic acid precursor (e.g., a sulfonyl fluoride functional group) (the layer formed by it is hereinafter referred to as the second layer) are formed into a film by co-extrusion, and a heating source and a vacuum source are used as needed to stack them in the order of a reinforcing material, a second layer / first layer composite film, and a heat-resistant release paper having air permeability on a flat plate or cylinder having a large number of pores on the surface, and the reinforcing material is stacked on each polymer. (ii) a method in which the fluorine-containing polymer (third layer) having a sulfonic acid group precursor is preliminarily formed into a film separately from the second layer / first layer composite film, and a heating source and a vacuum source are used as needed to laminate the third layer film, a reinforcing core material, and a composite film consisting of the second layer / first layer 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 the pressure at the melting temperature of each polymer, and the composite film is integrated at the same time.

[0980] Here, coextrusion of the first layer and the second layer helps to improve the bonding strength of the interface.

[0981] In addition, the method of integrating under reduced pressure has the characteristic that the thickness of the third layer on the reinforcing material is increased compared to the pressure pressing method. In addition, since the reinforcing material is fixed to the inner surface of the membrane body, it has the performance of being able to fully maintain the mechanical strength of the ion exchange membrane.

[0982] It should be noted that the lamination variation described here is an example, and a suitable lamination pattern (eg, combination of layers, etc.) may be appropriately selected in consideration of the desired layer structure or physical properties of the film body, and then co-extrusion may be performed.

[0983] 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 may 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 may be used instead of the second layer.

[0984] 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.

[0985] When the fourth layer is an ion exchange membrane, the first and fourth layers can be formed into a coextruded film, and the third and second layers can be formed separately from them and laminated using the above method; or the three layers of the first layer / fourth layer / second layer can be formed into a film by coextrusion at one time.

[0986] In this case, the direction in which the extruded film flows is the MD direction. In this way, a film body including a fluorine-containing polymer having an ion exchange group can be formed on the reinforcing material.

[0987] In addition, the ion exchange membrane preferably has a protruding part, i.e., a convex portion, consisting of a fluoropolymer having a sulfonic acid group on the surface side consisting of the sulfonic acid layer. As a method for forming such a convex portion, it is not particularly limited, and a known method for forming a convex portion on a resin surface can be adopted. Specifically, for example, a method for embossing the surface of a membrane body can be cited. For example, when the above-mentioned composite membrane and a reinforcing material etc. are integrated, the above-mentioned convex portion can be formed by using a release paper that has been embossed in advance. In the case of 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.

[0988] (5) Hydrolysis process

[0989] In the step (5), the membrane body obtained in the step (4) is hydrolyzed to convert the ion exchange group precursor into the ion exchange group (hydrolysis step).

[0990] In addition, in step (5), the sacrificial silk contained in the membrane body can be dissolved and removed by acid or alkali, thereby forming dissolution holes in the membrane body. It should be noted that the sacrificial silk can also remain in the connecting holes and is not completely dissolved and removed. In addition, the sacrificial silk remaining in the connecting holes can be dissolved and removed by the electrolyte when the ion exchange membrane is supplied to electrolysis.

[0991] The sacrificial wire is soluble in acid or alkali in the electrolytic environment during the manufacturing process of the ion exchange membrane, and the sacrificial wire is eluted to form a communication hole at the location.

[0992] 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.

[0993] The mixed solution preferably contains 2.5 to 4.0 N KOH and 25 to 35 mass % DMSO.

[0994] The hydrolysis temperature is preferably 70 to 100°C. The higher the temperature, the greater the apparent thickness. The more preferred temperature is 75 to 100°C.

[0995] The hydrolysis time is preferably 10 to 120 minutes. The longer the time, the greater the apparent thickness. More preferably, it is 20 to 120 minutes.

[0996] Here, the step of dissolving the sacrificial wire to form the communicating holes will be described in more detail. Fig.25 (a) and (b) are schematic diagrams for explaining a method of forming continuous pores in an ion exchange membrane.

[0997] exist Fig.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.

[0998] First, the reinforcing material is prepared by weaving the reinforcing wire 52 constituting the reinforcing core material in the ion exchange membrane and the sacrificial wire 504a for forming the communicating pores 504 in the ion exchange membrane. The communicating pores 504 are formed by dissolving the sacrificial wire 504a in step (5).

[0999] According to the above method, the weaving method of the reinforcing yarn 52 and the sacrificial yarn 504a can be adjusted according to the arrangement of the reinforcing core material and the communicating holes in the membrane body of the ion exchange membrane, so it is simple.

[1000] exist Fig.25 In (a), a plain woven reinforcing material is illustrated in which reinforcing yarns 52 and sacrificial yarns 504a are woven in both the longitudinal and transverse directions on the paper surface. However, the arrangement of the reinforcing yarns 52 and sacrificial yarns 504a in the reinforcing material can be changed as needed.

[1001] (6) Coating process

[1002] In step (6), a coating liquid containing inorganic particles obtained by pulverizing 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.

[1003] 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.

[1004] The adhesive is dissolved in a solution mixed with water and ethanol. It should be noted that the preferred volume ratio of water to ethanol is 10:1 to 1:10, more preferably 5:1 to 1:5, and further preferably 2:1 to 1:2. Inorganic particles are dispersed in the thus obtained solution using a ball mill to obtain a coating solution. At this time, the average particle size of the particles can also be adjusted by adjusting the time and rotation speed during the dispersion. It should be noted that the preferred mixing amounts of the inorganic particles and the adhesive are as described above.

[1005] The concentrations of the inorganic particles and the binder in the coating liquid are not particularly limited, but a dilute coating liquid is preferred so that the coating can be uniformly applied to the surface of the ion exchange membrane.

[1006] In addition, when dispersing the inorganic particles, a surfactant may be added to the dispersion. As the surfactant, a nonionic surfactant is preferred, and examples thereof include HS-210, NS-210, P-210, and E-212 manufactured by NOF Corporation.

[1007] 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.

[1008] [Microporous membrane]

[1009] As described above, the microporous membrane of the present embodiment is not particularly limited as long as it can form a laminate with the electrolytic electrode, and various microporous membranes can be applied.

[1010] The porosity of the microporous film 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.

[1011] Porosity = (1-(weight of the film in a dry state) / (weight calculated from the volume calculated from the thickness, width, and length of the film and the density of the film raw material)) × 100

[1012] The average pore size of the microporous membrane of the present embodiment is not particularly limited, and can be, for example, 0.01 μm to 10 μm, preferably 0.05 μm to 5 μm. The average pore size can be obtained by, for example, cutting the membrane perpendicularly to the thickness direction and observing the cross section by FE-SEM. The diameter of the observed pores is measured at about 100 points and averaged.

[1013] The thickness of the microporous membrane of the present embodiment is not particularly limited, and may be, for example, 10 μm to 1000 μm, and preferably 50 μm to 600 μm. The thickness can be measured using, for example, a micrometer (manufactured by Mitutoyo Corporation).

[1014] Specific examples of the microporous membrane include Zirfon Perl UTP 500 manufactured by Agfa (also referred to as Zirfon membrane in the present embodiment), microporous membranes described in International Publication No. 2013-183584, International Publication No. 2016-203701, and the like.

[1015] 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 bonded physically. 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 body 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 body contacts the electrode for electrolysis with appropriate bonding force, although the diaphragm or the power supply body and the electrode for electrolysis become one body, it is possible to show excellent electrolytic performance.

[1016] [Wound body]

[1017] The wound body of the present embodiment includes the laminate of the present embodiment. That is, the wound body of the present embodiment is formed by winding the laminate of the present embodiment. As in the wound body of the present embodiment, the laminate of the present embodiment is wound to reduce its size, thereby further improving the handling properties.

[1018] [Electrolyzer]

[1019] The electrolytic cell of the present embodiment includes the laminate of the present embodiment. Hereinafter, an embodiment of the electrolytic cell will be described in detail by taking the case of electrolyzing salt using an ion exchange membrane as a diaphragm as an example.

[1020] [Electrolysis unit]

[1021] Fig.26 is a cross-sectional view of the electrolysis unit 1.

[1022] The electrolytic unit 1 includes an anode chamber 10, a cathode chamber 20, a partition wall 30 disposed between the anode chamber 10 and the cathode chamber 20, an anode 11 disposed in the anode chamber 10, and a cathode 21 disposed in the cathode chamber 20. If necessary, a reverse current absorber 18 disposed 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 disposed in the cathode chamber 20, and a reverse current absorber 18 disposed in the cathode chamber 20, and the reverse current absorber 18 is as follows: Fig.30 As 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 collector 23, a support 24 supporting the collector, and a metal elastic body 22. The metal elastic body 22 is arranged between the collector 23 and the cathode 21. The support 24 is arranged between the collector 23 and the partition wall 30. The collector 23 is electrically connected to the cathode 21 through the metal elastic body 22. The partition wall 30 is electrically connected to the collector 23 through the support 24. Therefore, the partition wall 30, the support 24, the 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 through the 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. In addition, the electrical connection method may be as follows: the partition wall 30 and the support body 24 are directly mounted, the support body 24 and the collector 23 are directly mounted, the collector 23 and the metal elastic body 22 are directly mounted, and the cathode 21 is stacked on the metal elastic body 22. As a method of directly mounting these components to each other, welding, etc. can be cited. In addition, the reverse current absorber 18, the cathode 21, and the collector 23 can also be collectively referred to as the cathode structure 40.

[1023] Fig. 27 It is a cross-sectional view of two adjacent electrolytic units 1 in the electrolytic cell 4 . Fig.28 An electrolytic cell 4 is shown. Fig.29 4 shows the process of assembling the electrolytic cell 4. Fig. 27 As shown, the electrolytic unit 1, the cation exchange membrane 2, and the electrolytic unit 1 are arranged in series. The ion exchange membrane 2 is arranged between the anode chamber of one electrolytic unit 1 and the cathode chamber of the other electrolytic unit 1 in the two adjacent electrolytic units in the electrolytic cell. That is, the anode chamber 10 of the electrolytic unit 1 and the cathode chamber 20 of the adjacent electrolytic unit 1 are separated by the cation exchange membrane 2. Fig.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. Fig.29 As shown, the electrolytic cell 4 is assembled by arranging a plurality of electrolytic cells 1 in series with ion exchange membranes 2 interposed therebetween and connecting them with a pressurizer 5 .

[1024] 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. The current during electrolysis flows from the anode terminal 7 side to the cathode terminal 6 via the anode and cathode of each electrolytic cell 1. It should be noted that an electrolytic cell (anode terminal cell) having only an anode chamber and an electrolytic cell (cathode terminal cell) having only a cathode chamber may also be configured at both ends of the connected electrolytic cell 1. In this case, the anode terminal 7 is connected to the anode terminal cell configured at one end thereof, and the cathode terminal 6 is connected to the cathode terminal cell configured at the other end.

[1025] When the electrolysis of salt water is performed, salt water 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 salt water 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. Along with the electrolysis of the salt water, chlorine gas is generated on the anode 11 side, and sodium hydroxide (solute) and hydrogen gas are generated on the cathode 21 side.

[1026] (Anode chamber)

[1027] The anode chamber 10 has an anode 11 or an anode power supply 11. When the electrode for electrolysis of the present embodiment is inserted into the anode side, 11 functions as an anode power supply. When the electrode for electrolysis of the present embodiment is not inserted into the anode side, 11 functions as an anode. In addition, the anode chamber 10 preferably has: an anode side electrolyte supply unit for supplying electrolyte to the anode chamber 10; a baffle plate arranged above the anode side electrolyte supply unit and arranged approximately parallel to or obliquely to the partition wall 30; and an anode side gas-liquid separation unit arranged above the baffle plate and separating gas from the electrolyte mixed with gas.

[1028] (anode)

[1029] 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 so-called DSA (registered trademark) can be used as the anode 11. DSA refers to an electrode of a titanium base material whose surface is coated with oxides containing ruthenium, iridium, and titanium as components.

[1030] As the shape, any of punched metal, nonwoven fabric, foamed metal, expanded metal, porous metal foil formed by electroforming, so-called woven mesh produced by weaving metal wires, and the like can be used.

[1031] (Anode power supply)

[1032] When the electrode for electrolysis of the present embodiment is inserted into the anode side, an anode power supply 11 is provided in 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 without catalyst coating can be used. In addition, DSA with a reduced catalyst coating thickness can also be used. In addition, a used anode can also be used.

[1033] As the shape, any of punched metal, nonwoven fabric, foamed metal, expanded metal, porous metal foil formed by electroforming, so-called woven mesh produced by weaving metal wires, and the like can be used.

[1034] (Anode side electrolyte supply unit)

[1035] 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 tube) 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.

[1036] (Gas-liquid separation section on the anode side)

[1037] The anode-side gas-liquid separator is preferably disposed above the baffle. In electrolysis, the anode-side gas-liquid separator has the function of separating generated gas such as chlorine and electrolyte. It should be noted that, unless otherwise stated, the above refers to Fig.26 The upward direction of the electrolytic unit 1, the downward direction refers to Fig.26 The electrolysis unit 1 is in a downward direction.

[1038] 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, the pressure inside the electrolysis unit 1 will vibrate, 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 be separated into electrolyte and gas. As a result, vibration during electrolysis can be prevented.

[1039] (Baffle)

[1040] The baffle is preferably arranged above the electrolyte supply part 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 setting the baffle, the electrolyte (brine, etc.) can be circulated internally in the anode chamber 10 to make its concentration uniform. In order to produce internal circulation, the baffle is preferably arranged in a manner to separate 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 the electrolysis proceeds, the electrolyte concentration (brine concentration) decreases, and chlorine and other generated gases are generated. As a result, a gas-liquid specific gravity difference 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, and the concentration distribution of the electrolyte in the anode chamber 10 can be made more uniform.

[1041] It should be noted that although it is not shown Fig.26 , but a current collector may be separately provided inside the anode chamber 10. The current collector 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.

[1042] (Separation wall)

[1043] 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 and the cathode chamber 20. As the partition wall 30, a material known as a separator plate for electrolysis can be used, for example, a partition wall formed by welding a nickel plate on the cathode side and a titanium plate on the anode side.

[1044] (Cathode chamber)

[1045] Regarding the cathode chamber 20, when the electrode for electrolysis of the present embodiment is inserted into the cathode side, 21 functions as a cathode power supply body, and when the electrode for electrolysis 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 body 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 the parts constituting the anode chamber 10.

[1046] (cathode)

[1047] When the electrode for electrolysis 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 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 required. In addition, the cathode 21 may be subjected to reduction treatment as required. It should be noted that as the substrate of the cathode 21, nickel, nickel alloy, or a substrate obtained by plating iron or stainless steel with nickel may also be used.

[1048] As the shape, any of punched metal, nonwoven fabric, foamed metal, expanded metal, porous metal foil formed by electroforming, so-called woven mesh produced by weaving metal wires, and the like can be used.

[1049] (Cathode power supply)

[1050] When the electrolysis electrode of the present embodiment is inserted into the cathode side, a cathode power supply 21 is provided in the frame of the cathode chamber 20. The cathode power supply 21 may be coated with a catalyst component. The catalyst component may 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 metal may be cited. As the formation method of the catalyst layer, plating, alloy plating, dispersion composite plating, CVD, PVD, thermal decomposition and spraying may be cited. These methods may also be combined. The catalyst layer can have multiple layers and multiple elements as required. In addition, nickel, nickel alloy, iron or stainless steel plated with nickel without catalyst coating can also be used. It should be noted that, as the base material of the cathode power supply body 21, nickel, nickel alloy, iron or stainless steel plated with nickel can also be used.

[1051] As the shape, any of punched metal, nonwoven fabric, foamed metal, expanded metal, porous metal foil formed by electroforming, so-called woven mesh produced by weaving metal wires, and the like can be used.

[1052] (Reverse current absorption layer)

[1053] As the material of the reverse current absorption layer, a material having a redox potential lower than the redox potential of the element used for the cathode catalyst layer can be selected, for example, nickel, iron, etc.

[1054] (Current Collector)

[1055] The cathod...

Claims

1. A manufacturing method of an electrolytic cell, which is a method for manufacturing a new electrolytic cell by laminating a laminate on an original electrolytic cell. The original electrolytic cell includes an anode, a cathode facing the anode, and a diaphragm disposed between the anode and the cathode. Among them, The manufacturing method of the electrolytic cell has the following steps: Step (A), integrating an electrolysis electrode and a new diaphragm at a temperature at which the diaphragm does not melt, thereby obtaining the laminate; And Step (B), after step (A), replacing the diaphragm in the original electrolytic cell with the laminate.

2. The manufacturing method of the electrolytic cell according to claim 1, Among them, The integration is carried out under normal pressure.

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