JP2018154908A - Electrode for electrolysis, electrolytic unit and electrolyzed water generating apparatus using the electrode for electrolysis - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power-saving electrode for electrolysis, an electrolytic unit and an electrolyzed water generating apparatus using the same.SOLUTION: An electrode for electrolysis 11 comprises: a flat electrolysis substrate having a first main surface 18 and a second main surface opposite to the first main surface 18; an opening 16 disposed at least on the first main surface 18; wherein the first main surface 18 has a groove 3 having a first depth ranging from 100 to 1500 nm arranged from one end part of the opening 16 to around thereof. An electrolytic unit comprises: an electrode for electrolysis 6; a second electrode disposed so as to confront the electrode for electrolysis 6; and a first separating membrane disposed between the electrode for electrolysis 11 and the second electrode.SELECTED DRAWING: Figure 4

Description

  Embodiments described herein relate generally to an electrode for electrolysis, an electrolysis unit using the electrode, and an electrolyzed water generating apparatus.

  2. Description of the Related Art In recent years, electrolyzers have been provided that generate electrolyzed water having various functions by electrolyzing water, such as alkali ion water, ozone water, or hypochlorous acid water. Among electrolyzed water, hypochlorous acid water has an excellent sterilizing power and is safe for the human body and approved as a food additive. The electrolyzer is also used for hydrogen production and the like.

  As an electrolysis apparatus, for example, an electrolyzed water generation apparatus having a three-chamber electrolysis tank has been proposed. The inside of the electrolytic cell is divided into three chambers, an intermediate chamber, and an anode chamber and a cathode chamber located on both sides of the intermediate chamber, by a cation exchange membrane and an anion exchange membrane. The anode chamber and the cathode chamber are provided with an anode and a cathode, respectively. As the electrode, a porous electrode in which a large number of holes are processed by expanding, etching, or punching on a metal plate substrate is used, but there is a problem that the voltage is high.

  In such an electrolysis apparatus, for example, salt water is passed through the intermediate chamber, and water is circulated through the anode chamber and the cathode chamber, respectively. By electrolyzing the salt water in the intermediate chamber at the cathode and the anode, hypochlorous acid water and chlorine are generated at the anode, and sodium hydroxide water and hydrogen are generated at the cathode chamber. The generated hypochlorous acid water is used as sterilizing / disinfecting water, and sodium hydroxide water is used as washing water. Hydrogen is used as hydrogen water or fuel. In particular, when chlorine and hydrogen are mainly produced, electrolysis is performed with a larger current.

International Publication No. 2016/043109 Japanese Patent No. 5777752

  An object of an embodiment of the present invention is to provide a power-saving electrolysis electrode.

The electrode for electrolysis according to the embodiment includes a planar electrode substrate having a first main surface and a second main surface opposite to the first main surface;
At least an opening provided in the first main surface;
The first main surface includes a groove having a first depth in the range of 100 to 1500 nm provided from an end of the opening to the periphery of the opening.

It is a schematic diagram showing the mode of the opening periphery of the electrode for electrolysis which concerns on embodiment. It is a schematic sectional drawing showing an example of the electrode for electrolysis which concerns on embodiment. It is a schematic sectional drawing showing an example of the composition of the electrolysis unit concerning an embodiment. It is a figure showing the mode around the opening of the electrode for electrolysis of FIG. It is a figure showing the mode around the opening of the electrode for a comparison electrolysis. It is a figure showing the mode around the opening of the modification of the electrode for electrolysis concerning embodiment. It is the schematic which shows the state of the oxide film of the electrode for electrolysis concerning embodiment. It is the schematic which shows the state of the oxide film of the electrode for electrolysis concerning other embodiment. It is the schematic showing the schematic showing another example of the member used for formation of a groove | channel. It is the schematic showing the schematic showing another example of the member used for formation of a groove | channel. It is a schematic sectional drawing showing an example of the structure of the electrolyzed water generating apparatus which concerns on embodiment. It is an optical microscope photograph of the groove | channel of the electrode for electrolysis which concerns on embodiment. FIG. 13 is an AFM image showing the in-plane roughness of a part of the groove in FIG. 12. It is a graph showing the analysis data of the cross section of FIG. It is a graph showing the analysis data of the cross section of FIG. It is an optical microscope photograph of the groove | channel of the electrode for electrolysis which concerns on embodiment. It is an AFM image showing the in-plane roughness of a part of the groove of FIG. It is a graph showing the analysis data of the cross section of FIG.

  Hereinafter, embodiments will be described with reference to the drawings.

  In addition, the same code | symbol shall be attached | subjected to a common structure through embodiment, and the overlapping description is abbreviate | omitted. In addition, each drawing is a schematic diagram for promoting the embodiment and its understanding, and its shape, dimensions, ratio, etc. are different from the actual device, but these are considered in consideration of the following description and known techniques. The design can be changed as appropriate. For example, in the drawing, the electrodes are drawn on a plane, but may be bent in accordance with the shape of the electrolysis unit or may be cylindrical.

  The electrode for electrolysis according to the embodiment includes a planar electrode base material having a first main surface and a second main surface opposite to the first main surface. An opening is included in at least the first main surface of both main surfaces.

  The number of openings is one or more.

  At least a first groove is provided from the end of at least one of the openings to the periphery.

  In FIG. 1, the schematic diagram showing the mode of the opening periphery of the electrode for electrolysis which concerns on embodiment is shown.

  As shown in the figure, the electrode 6 for electrolysis has an opening 1 provided in the planar electrode base 5 and a first groove 3 provided from the end 2 of the opening 1 to the periphery.

  The depth of the first groove 3 is 100 to 1500 nm.

  The depth of the groove is determined by taking four measurement points around the opening, and using an optical microscope, confirming the groove at a magnification capable of sufficiently observing the groove at the opening end of 200 times, for example, AFM (Atomic Force Microscope) Measure with a force microscope.

  The electrolysis unit according to the embodiment includes the electrolysis electrode, a counter electrode disposed to face the electrolysis electrode, and a first diaphragm disposed between the electrolysis electrode and the counter electrode.

  The electrolyzed water generating apparatus according to the embodiment is equipped with the electrolysis unit.

  For example, the electrolyzed water generating apparatus can have an electrolytic cell, an electrolytic unit incorporated in the electrolytic cell, a first electrode chamber and a second electrode chamber partitioned by the electrolytic unit. The electrolysis unit can be equipped with a mechanism for applying a voltage, for example, a power source for applying a voltage to the electrodes, a control device, and the like.

  According to the embodiment, since the hydrophilicity of the planar electrode substrate is improved by using the electrode for electrolysis having a groove provided from the end of the opening to the periphery, the bubbles generated in the opening during the electrolysis and the opening end In between, the electrolyte efficiently enters, and the bubbles are detached from the opening without increasing in size. Thereby, since it becomes easy to contact electrolyte solution and an electrode base material, a raise of a voltage can be prevented.

  As a method for producing an electrode for electrolysis, a planar electrode substrate having a first main surface and a second main surface opposite to the first main surface and having an opening provided at least on the first main surface is prepared, At least from the end of the opening to the periphery of the opening, a rough file is contacted and rubbed to form a groove.

  According to the embodiment, since the hydrophilicity of the planar electrode base material is improved by forming a plurality of grooves from the end of the opening to the periphery, the gap between the bubble generated in the opening and the opening end during electrolysis is improved. The electrolytic solution enters efficiently, bubbles are detached from the opening without increasing in size, and the electrolytic solution and the electrode substrate are easily brought into contact with each other, so that an increase in voltage can be prevented.

  Also, depending on the material of the electrode base material, such as stainless steel, when a thick oxide film is chemically formed on the surface in the process of providing an opening, etc., if a groove is physically formed by a file or the like, a thick oxide film is formed. By removing the film, the resistance of the electrode can be lowered and the voltage rise can be prevented. When the oxide film is physically removed, a natural oxide film is formed. However, the oxide film is much thinner than a chemically formed oxide film, and the effect of reducing the resistance of the electrode can be sufficiently obtained. Furthermore, in the planar electrode substrate, the resistance of the electrode can be further reduced by widening the filed area.

  The first groove having the first depth has a deflection width of 50 μm or less in the in-plane direction and 20 μm near the end of the opening on the electrode surface in an 1 mm square optical microscope observation near the end of the opening on the electrode surface. It can have a deflection width of 5 μm or more and 20 μm or less in the in-plane direction in the four-way atomic force microscope observation.

  In the embodiment, the groove refers to a recess having a length of 10 times or more of the width in 20 μm square atomic force microscope observation.

  A method for producing such an electrode is provided with a planar electrode substrate having a first principal surface and a second principal surface opposite to the first principal surface, and at least an opening is provided in the first principal surface. It is produced by stretching and pressing the electrode material substrate using a rolling roller having irregularities of 100 to 1500 nm formed on the surface.

  According to the embodiment, by forming a plurality of substantially linear grooves in a wide area from the end of the opening to the periphery, the hydrophilicity of the planar electrode base material is improved, so that bubbles generated in the opening during electrolysis Since the electrolytic solution efficiently enters between the opening and the opening, bubbles are detached from the opening without increasing in size, and the electrolytic solution and the electrode base material are easily brought into contact with each other, voltage increase and variation can be reduced. In addition, in a narrow region, the voltage can be lowered because the electrode area increases in a groove having undulations.

  The electrode for electrolysis according to the embodiment is provided from the end of the opening to the periphery of the opening, and further includes one or more grooves having a second depth different from the first depth, and the maximum of the second depths. The depth can be 200 μm or less.

  The presence of a plurality of grooves further increases hydrophilicity and facilitates bubble detachment. However, when the maximum depth exceeds 200 μm, mechanical strength, particularly when hydrogen embrittlement occurs, the strength decreases.

  The groove having the second depth is a width of 50 μm or less in the in-plane direction in the 1 mm square optical microscope observation near the edge of the opening on the electrode surface, and in the plane in the 20 μm square AFM observation near the edge of the opening. It can be confirmed that there is a undulation having a swing width of 5 μm or more and 20 μm or less in the direction.

  The groove used in the embodiment may be provided in one direction. When there is a water flow, it is better that the grooves are parallel to the water flow to eliminate bubbles. If there is no water flow and bubbles naturally escape by gravity, the groove should be in the horizontal direction.

  The groove used in the embodiment is preferably provided on both the first main surface and the second main surface. By providing on both sides, air bubbles are more likely to escape.

(First and second embodiments)
FIG. 2 is a schematic cross-sectional view illustrating an example of the electrode for electrolysis according to the first embodiment.

  FIG. 3 is a schematic sectional view showing an example of the configuration of the electrolysis unit according to the second embodiment.

  As shown in FIG. 2, the first electrode 11 for electrolysis has a first main surface 18 and a second main surface 19 opposite to the first main surface 18. An opening 16 is provided in the first main surface 18, and an opening 17 is provided in the second main surface 19. In FIG. 1, the opening 16 and the opening 17 are penetrating. The first electrolysis electrode 11 has a porous structure provided with a plurality of such through holes. The opening 16 and the opening 17 do not need to penetrate, and the opening only needs to be provided on at least the first main surface.

  As shown in FIG. 3, the electrolysis unit 10 includes a first electrolysis electrode 11 shown in FIG. 2, a second electrolysis electrode 12 disposed opposite to the first electrolysis electrode 11, a first electrolysis electrode 11 and a second electrolysis electrode. A first diaphragm 13 disposed between the electrodes 12 is included. The second electrolytic electrode 12 and the first diaphragm 13 can be disposed on the first main surface 18 side of the first electrolysis electrode 11. As the first diaphragm, a cation-permeable membrane, for example, Nafion, a porous Teflon (registered trademark) which is a porous membrane having a negative zeta potential, a polyvinylidene fluoride membrane, silicon oxide, tungsten oxide or titanium oxide is used. A coated porous membrane or the like can be used.

  The second electrolysis electrode 12 may have a porous structure as shown in FIG. Alternatively, there may be no holes. Further, the first electrolysis electrode 11 and the first diaphragm 13 can be contacted as shown in FIG. Alternatively, other structures can be interposed. In addition, a second diaphragm 14 can be provided between the first diaphragm 13 and the second electrolysis electrode 12. Thereby, the structure 15 which hold | maintains electrolyte solution between the 1st diaphragm 13 and the 2nd diaphragm 14 can be formed. The second electrolytic electrode and the first diaphragm can be disposed on the first main surface side of the first electrolysis electrode. As the second membrane, an anion-permeable porous membrane, such as an anion exchange membrane having a quaternary ammonium salt as a measurement, or a teflon coated with alumina, titania or zirconia having a neutral or acidic zeta potential and positive Or a porous film of vinylidene fluoride can be used.

  FIG. 4 is a diagram illustrating a state around the opening of the electrode for electrolysis in FIG.

  As shown in the drawing, a circular opening 16 is provided on the first main surface 18 of the first electrode 11 for electrolysis made of stainless steel (SUS), for example, by punching. A first groove 21 provided from the opening end 31 of the opening 16 to the flat portion around the opening 32 is provided.

  According to the embodiment, the groove having a depth in the range of 100 nm to 1500 nm exists, and the hydrophilicity of the electrode is increased, so that hydrophobic gas desorption at the open end is successful.

  The groove may have any cross-sectional shape, but is preferably V-shaped or U-shaped. V-shaped and U-shaped may have rounded corners. The cross-sectional depth and cross-sectional shape of the groove are measured by AFM at least at three locations in a 20 μm square region.

  The directionality of the groove may be random, may be unidirectional, or may be orthogonal. If it is random, the hydrophilicity can be increased.

  As shown in FIG. 4, when a groove is provided from the opening end to the periphery of the opening, the bubbles tend to spread out from the opening, but since the grooves are in the direction of spreading, water can easily enter the grooves and the bubbles should be large. Desorption occurs.

  When the number of grooves extending from the end of the opening of the electrode for electrolysis to the periphery of the opening is less than 2, there is a tendency that bubbles are not easily detached.

  The plurality of grooves including the first groove and the second groove can be provided over a wide range at least on the first main surface.

  The material of the planar electrode substrate can be titanium or stainless steel.

  An opening and a groove can be provided on the second main surface of the electrode for electrolysis according to the embodiment in the same manner as the first main surface.

  When the first electrode is a cathode, the generated gas is mainly hydrogen. Oxygen, chlorine, etc. are generated at the second electrode as the anode. The groove structure is effective for removing bubbles such as hydrogen and oxygen.

  FIG. 5 is a diagram illustrating a state around the opening of a comparative electrolysis electrode.

  The electrode 33 for electrolysis is a porous electrode base material in which a large number of holes are processed by punching, and an opening periphery 34 is smoothed during punching. Here, the groove from the opening end to the periphery of the opening is not formed. For this reason, sufficient hydrophilicity of the electrode cannot be obtained, and the hydrogen bubbles 35 tend to be difficult to desorb. If the hydrogen bubbles generated during electrolysis do not desorb, electrolysis does not occur in the electrode region, and therefore the voltage increases in an attempt to increase electrolysis in other regions during constant current operation.

This tendency becomes more prominent as driving at a high current density of 100 mA / cm ² or more.

On the other hand, when the first electrolysis electrode according to the embodiment is used, even when connected to a power source that operates at a current density of 100 mA / cm ² or more, hydrogen bubbles are detached, so that it is difficult for voltage increase to occur. can do.

  FIG. 6 is a diagram illustrating a state around an opening of a modified example of the electrode for electrolysis according to the embodiment.

  This electrode 45 for electrolysis is a porous electrode base material in which a large number of holes are processed by punching, and is the same as FIG. 4 except that the opening periphery 34 ′ is smoothed during punching. The surface roughness of the opening periphery 34 ′ is smaller than the surface roughness of the outer region 32 ′ with the end 36 of the opening periphery 34 ′ as a boundary.

  Even when the opening periphery 34 'is smoothed during punching, the first electrode 21 is formed from the opening end 31 to the opening periphery 34'. Therefore, the electrode 45 for electrolysis is opened through these grooves. Water can easily enter 16 and hydrogen bubbles can be detached without increasing.

  FIG. 7 is a schematic diagram illustrating a state of an oxide film of the electrode for electrolysis according to the embodiment.

  As shown in the drawing, a thick oxide is formed on the surface of the electrode substrate 40 for electrolysis made of SUS having an opening by a process such as punching or etching. According to the method for manufacturing an electrode substrate for electrolysis according to the embodiment, when the groove 21 is formed by contacting a file, the oxide layer is greatly scraped, and this action is physical. Since the object is a thin native oxide, the final oxide layer 41 is thinner than before the file is contacted. Thereby, the resistance of the electrode substrate for electrolysis 40 can be reduced, and the electrolysis drive voltage can be reduced. In the embodiment, since the file is used, the oxide can be physically removed. However, depending on the jig and the chemical used in the operation for forming the groove, the oxide can hardly be removed. If it remains thick, it is difficult to obtain the effect of reducing the resistance of the electrode substrate for electrolysis.

  FIG. 8 is a schematic view showing a state of an oxide film of an electrode for electrolysis according to another embodiment.

  As shown in the drawing, unless a groove is formed by contacting a file, the driving voltage is likely to increase because the oxide 42 having a thickness exists on the entire surface of the electrode substrate 50 for metal electrolysis.

  The method for producing an electrode for electrolysis comprises preparing a planar electrode substrate having a first main surface and a second main surface opposite to the first main surface, and at least an opening provided in the first main surface, It includes contacting a rubbing file from the end of the opening to the periphery of the opening and rubbing to form a plurality of grooves.

  The file used preferably has a particle size of # 80 to # 1000. More preferably, it has a particle size of # 80 to # 100.

  When it is less than # 80, the maximum depth of the groove tends to be less than 100 nm, and when it exceeds # 1000, the maximum depth of the groove tends to be larger than 1500 nm.

  In the above method, a rough file is used in the step of forming a plurality of grooves, but other members can be used for forming the grooves.

  FIG. 9 is a schematic diagram illustrating another example of a member used for forming a groove.

  A groove can be formed on the electrode surface by arranging a grinder as shown in the figure or a paper file on the surface of the electrode for electrolysis and processing the electrode for electrolysis.

  The grinder 60 accommodated a disc-shaped grinding wheel 62, a spindle (not shown) connected to a motor that rotates the grinding wheel 62, a spindle collar 64 that covers the spindle, and a gear that changes the rotation of the grinding wheel 62. A gear housing 65 and a main body 61 indicating the gear housing 65 are included.

  FIG. 10 is a schematic diagram illustrating another example of a member used for forming a groove.

  As shown in the figure, for example, a hard roller 77 provided with a convex portion 76 is disposed on the surface of an electrode base 74 for electrolysis made of a flat metal substrate 72 provided with an oxide layer 73, and the electrode base for electrolysis is provided. By rotating the roller 77 in the direction of arrow 71 on 74, a groove can be formed on the surface of the electrode base material 74 for electrolysis.

(Third embodiment)
The electrolysis apparatus of the embodiment can mount the electrolysis unit of the first embodiment.

  The electrode for electrolysis according to the embodiment can be used as a cathode.

  Thereby, a power-saving electrolysis apparatus can be obtained.

  FIG. 11 is a schematic cross-sectional view illustrating an example of the configuration of the electrolyzed water generating device according to the third embodiment.

  The electrolyzed water generating device 550 includes a three-chamber electrolysis unit 508 and an electrode unit 507. The electrolysis unit 508 is formed in a flat rectangular box shape, and the inside thereof is partitioned into three chambers of an anode chamber 510, a cathode chamber 511, and an intermediate chamber 506 formed between electrodes by a partition wall 509 and an electrode unit 507. It has been.

  The electrode unit 507 includes a second electrode 503 positioned in the anode chamber 510, a first electrode 504 positioned in the cathode chamber 511 and having a plurality of predetermined through holes, and a second electrode side of the first electrode 504. A first porous diaphragm (electrolyte membrane) 502 is provided on the surface. A second porous diaphragm 501 can be provided on the first electrode side surface of the second electrode 503. The second electrode 503 and the first electrode 504 face each other in parallel with a gap therebetween, and an intermediate chamber (electrolytic chamber) that holds an electrolytic solution between the second porous diaphragm 501 and the first porous diaphragm 502. Liquid chamber) 506 is formed. A holding body (not shown) that holds the electrolytic solution may be provided in the intermediate chamber 506. The second electrode 503 and the first electrode 504 may be connected to each other by a plurality of bridges (not shown) having insulating properties.

  The electrolyzed water generating device 550 includes a power source 514 for applying a voltage to the second electrode 503 and the first electrode 504 of the electrode unit 507, and a control device 513 for controlling the power source 514. An ammeter 516 and a voltmeter 515 can be provided between the power source 514 and the second electrode 503 and the first electrode 504. An ammeter 516 and a voltmeter 515 can be connected to the control device 513.

  A liquid channel can be provided in the anode chamber 510 and the cathode chamber 511. From the line L1 for introducing an electrolyte solution containing chloride ions into the intermediate chamber 506, the electrolyte solution tank 517 connected to the line L1, the line L3 for supplying water from the water supply source to the anode chamber 510 and the cathode chamber 511, from the anode chamber 510 A line L4 for taking out the acidic electrolyzed water and a line L5 for taking out the alkaline electrolyzed water from the cathode chamber 511 can be further provided. Further, a line L2 for recovering an excess electrolyte solution containing chloride ions from the intermediate chamber 506 and circulating it to the electrolyte solution tank 517 may be provided. Instead of the line L2, an electrolyte solution containing chloride ions may be provided. A line for discharging can be provided. A conductivity sensor 518 can be attached to the line L4 for taking out the acidic electrolyzed water as a water quality sensor, and a pH sensor 519 can be attached to the line L5 for taking out the alkaline electrolyzed water.

Example 1
An electrolysis unit having the same configuration as that of FIG. 3 is produced.

  As the cathode electrode base material, 0.5 mm-thick flat SUS310S is used, and 2 mm-diameter holes are punched at a pitch of 3 mm. The surface of this electrode is scraped on both surfaces using a paper file having a particle size of # 100 to form a groove.

  FIG. 12 shows an optical micrograph of the groove formed from the end of the opening to the periphery.

  As shown in FIG. 12, it can be seen from the optical micrograph that a groove is formed from the open end toward the electrode surface.

  FIG. 13 shows an AFM image representing the in-plane roughness of a part of the groove of FIG.

  FIG. 14 is a graph showing analysis data of the cross section of the electrode surface represented by X in FIG.

  FIG. 15 is a graph showing analysis data of the cross section of the electrode surface represented by Y in FIG.

  As shown in FIGS. 14 and 15, it can be seen from AFM measurement that the depth of the deep groove is 1000 nm at the maximum and from 100 nm to 300 nm from the opening end to the periphery of the opening in FIG. 12. There are also grooves shallower than 100 nm.

A flat titanium substrate having a thickness of 0.5 mm is used as the anode electrode substrate, and holes having a diameter of 2 mm are formed by punching in a staggered manner at a pitch of 3 mm. This electrode is treated at 80 ° C. for 1 hour in a 10 wt% aqueous oxalic acid solution. After applying a solution prepared by adding 1-butanol to iridium chloride (IrCl ₃ .nH ₂ O) to 0.25 M (Ir) on the surface of the small opening of the anode electrode substrate, drying and baking are performed. To do. In this case, drying is performed at 80 ° C. for 10 minutes, and baking is performed at 450 ° C. for 10 minutes. Such a coating, drying, and firing are repeated five times to obtain a positive electrode for producing an iridium oxide catalyst.

  An anion exchange membrane having a quaternary ammonium salt as an ion exchange group is used as the porous membrane on the positive electrode side. An electrolysis unit having the same configuration as that shown in FIG. 3 is prepared using Nafion 117 as the negative electrode-side porous diaphragm.

  Using this electrolysis unit, an electrolyzed water generating apparatus having the same configuration as in FIG. 11 is produced.

  The size of the opening of both electrodes is 10 cm × 14 cm.

  A positive electrode chamber and a negative electrode chamber made of vinyl chloride with straight channels formed therein are formed, and a tank for supplying saturated saline is connected to the electrolysis unit. In addition, a control device, power supply, voltmeter, and ammeter are installed, piping and pumps for supplying tap water to the anode chamber and cathode chamber, and a saturated saline reservoir for circulating and supplying saturated saline to porous polystyrene. And piping and pumps.

  Using this electrolyzed water generator, hypochlorous acid water is produced on the anode side and sodium hydroxide water is produced on the cathode side. The drive voltage when electrolyzed at 30 A is 8.0V.

(Examples 2 to 5)
As shown in Table 1, an electrolysis unit and an electrolysis apparatus are produced in the same manner as in Example 1 except that the type of paper file is changed.

  The electrode has a groove included in a depth range of 100 nm to 1500 nm.

  The obtained results are shown in Table 1 below.

(Comparative Example 1)
An electrolytic device is manufactured in the same manner as in Example 1 except that the surface is not cut using a paper file having a particle size of # 100. The drive voltage when electrolyzed at 30A is 9.0V.

(Comparative Example 2)
The surface was not cut using a paper file having a particle size of # 100, but the electrode was immersed in 1N hydrochloric acid for 7 minutes, washed with water and dried, and then the surface was cut to create irregularities. To prepare an electrolysis apparatus. The drive voltage when electrolyzed at 30A is 9.0V.

(Comparative Examples 3-5)
An electrolysis unit and an electrolysis apparatus are produced in the same manner as in Example 1 except that a paper file having a large particle size is used instead of a paper file having a particle size of # 100. Table 1 below shows the maximum groove depth and the driving voltage when electrolysis is performed at 30A. As shown in Table 1, the driving voltage is 8.5V or higher.

(Example 6)
An electrolysis unit and an electrolysis apparatus are produced in the same manner as in Example 1 except that only the electrode surface on the porous diaphragm side is scraped with a paper file instead of the electrode surfaces.

  The drive voltage when electrolyzed at 30 A is 8.2V.

(Example 7)
An electrolysis unit and an electrolysis apparatus are produced in the same manner as in Example 1 except that titanium is used instead of SUS310S.

The drive voltage when electrolyzed at 30A is 8.1V.

(Example 8)
An electrolysis unit and an electrolysis apparatus are produced in the same manner as in Example 1 except that the paper file is scraped in parallel with the upper direction from which hydrogen gas generated at the negative electrode is desorbed.

  The drive voltage when electrolyzed at 30 A is 7.9V.

Example 9
Instead of punching the polished electrode material, a photoresist is applied to the polished electrode material on both sides, the pattern is exposed on one side, the resist is removed, etching with acid, and the unexposed resist is removed by removing the resist. An electrolysis unit and an electrolysis device are produced in the same manner as in Example 1 except that 2 mm diameter openings similar to those in Example 1 are formed in a staggered manner at a pitch of 3 mm on the electrode substrate.

  The drive voltage when electrolyzed at 30 A is 8.0V.

(Example 10)
Instead of punching the polished electrode material, a photoresist is applied to the polished electrode material on both sides, the pattern is exposed on one side, the resist is removed, etching with acid, and the unexposed resist is removed by removing the resist. An electrolysis unit and an electrolysis apparatus are produced in the same manner as in Example 1 except that an opening and a groove having a depth of 200 μm are produced in the electrode base as in Example 1.

  The drive voltage when electrolyzed at 30 A is 8.2V.

(Example 11)
As the cathode electrode base material, 0.5 mm-thick flat SUS310S is used, and 2 mm-diameter holes are punched at a pitch of 3 mm. Next, it rolls and presses with the roller whose unevenness | corrugation is 30-500 nm.

  An optical micrograph of this electrode is shown in FIG. 16, and AFM is shown in FIG.

  FIG. 18 shows cross-sectional analysis data.

As shown in FIG. 16, the groove observed with the optical microscope is substantially straight. FIG. 17 shows an example of the surface shape of the electrode observed with an AFM of 20 μm square.

  As shown in the figure, in the 20 μm square AFM observation, waviness is observed in the groove. The depth of the groove is 200 to 300 nm.

A flat titanium substrate having a thickness of 0.5 mm is used as the anode electrode substrate, and holes having a diameter of 2 mm are formed by punching in a staggered manner at a pitch of 3 mm. This electrode is treated at 80 ° C. for 1 hour in a 10 wt% aqueous oxalic acid solution. After applying a solution prepared by adding 1-butanol to iridium chloride (IrCl ₃ .nH ₂ O) to 0.25 M (Ir) on the surface of the small opening of the anode electrode substrate, drying and baking are performed. To do. In this case, drying is performed at 80 ° C. for 10 minutes, and baking is performed at 450 ° C. for 10 minutes. Such a coating, drying, and firing are repeated five times to obtain a positive electrode for producing an iridium oxide catalyst.

  An anion exchange membrane having a quaternary ammonium salt as an ion exchange group is used as the porous membrane on the positive electrode side. An electrolysis unit having the same configuration as that shown in FIG. 3 is prepared using Nafion 117 as the negative electrode-side porous diaphragm.

  Using this electrolysis unit, an electrolyzed water generating apparatus having the same configuration as in FIG. 11 is produced.

  The size of the opening of both electrodes is 10 cm × 14 cm.

  A positive electrode chamber and a negative electrode chamber made of vinyl chloride with straight channels formed therein are formed, and a tank for supplying saturated saline is connected to the electrochemical unit. In addition, a control device, a power source, a voltmeter, and an ammeter are installed, and piping and pumps for supplying tap water to the anode chamber and the cathode chamber, and saturated saline for circulating and supplying saturated saline to porous polystyrene Useless pipes and pumps will be installed.

  Using this electrolyzed water generator, hypochlorous acid water is produced on the anode side and sodium hydroxide water is produced on the cathode side. The drive voltage when electrolyzed at 30 A is 7.8V.

(Comparative Example 6)
Next, an electrolyzed water generating apparatus is produced in the same manner as in Example 1 except that an electrode on which no surface groove is observed with an optical microscope is used by rolling and pressing with a mirror surface roller having an unevenness of 10 to 50 nm. The drive voltage when electrolyzed at 30A is 9.0V.

Table 1 below shows the maximum depth of the first groove, the maximum depth of the second groove included in the range of 100 nm to 1500 nm from the AFM measurement of Examples 1 to 11, and the driving voltage when electrolyzed at 30A.

  In the table, the item of the maximum depth of 100 to 1500 nm of the first depth describes the value of the maximum depth when there is a groove having the first depth in the range of 100 to 1500 nm. When there is no groove having a depth, “None” is described.

  In addition, the item of the maximum depth of <100 nm of the second depth is that when there is a groove having the second depth in the range of less than 100 nm, the maximum depth can be measured if it can be measured. Indicates that the groove is “present”. On the other hand, when there is no groove having the second depth in the range of less than 100 nm, “None” is described.

  Further, in the item of the second depth exceeding 1500 nm to 500 μm maximum depth, when there is a groove having the second depth in the range of more than 1500 nm and 500 μm or less, the value of the maximum depth is described. On the other hand, if there is no groove having a second depth in the range of greater than 1500 nm and less than or equal to 500 μm, it is described as “none”.

  As shown in Table 1, the electrolyzed water generating apparatus using this electrode has a driving voltage of 8.3 V or less during electrolysis and can be operated at a low voltage.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 10 ... Electrolytic unit, 11 ... 1st electrode for electrolysis, 12 ... Electrode for 2nd electrolysis, 13 ... 1st diaphragm, 14 ... 2nd diaphragm, 16 ... Opening, 17 ... Opening, 18 ... 1st main surface, 19 ... 2nd main surface, 21 ... 1st groove | channel, 22 ... 2nd groove | channel, 31 ... opening edge, 32 ... opening periphery, 41, 42 ... oxide film, 501 ... 2nd porous diaphragm, 502 ... 1st porous 503 ... second electrode, 504 ... first electrode, 507 ... electrode unit, 508 ... electrolyzer, 509 ... partition wall, 510 ... anode chamber, 511 ... cathode chamber, 513 ... control device, 514 ... power source, 515 ... voltage 516 ... Ammeter 517 ... Salt water tank 518 ... Conductivity sensor 519 ... pH sensor

Claims (9)

A planar electrode substrate having a first main surface and a second main surface opposite to the first main surface;
At least an opening provided in the first main surface;
The first main surface is an electrode for electrolysis including a groove having a first depth in a range of 100 to 1500 nm provided from an end of the opening to the periphery of the opening.   The groove having the first depth has a swing width of 50 μm or less in an optical microscope observation of 1 mm square near the end of the opening, and 5 μm or more and 20 μm in 20 μm square atomic force microscope observation near the end of the opening. The electrode for electrolysis of Claim 1 which has the following runout width.   1 or 2 or more groove | channels provided from the edge part of the said opening to the circumference | surroundings of the said opening, and having the 2nd depth different from the said 1st depth, The maximum depth is 200 micrometers or less among the said 2nd depth. The electrode for electrolysis according to claim 1 or 2.   The groove having the second depth has a swing width of 50 μm or less in the 1 mm square optical microscope observation near the end of the opening, and 5 μm or more and 20 μm in the 20 μm square atomic force microscope observation near the end of the opening. The electrode for electrolysis of Claim 3 which has the following deflection widths.   The electrode for electrolysis according to claim 1, wherein the groove is provided in one direction.   The electrode for electrolysis according to any one of claims 1 to 5, wherein the groove is provided on both the first main surface and the second main surface.   A first electrode comprising the electrode for electrolysis according to any one of claims 1 to 6, a second electrode disposed opposite to the first electrode, and disposed between the first electrode and the second electrode. An electrolysis unit including the first diaphragm.   The electrolysis unit according to claim 7, wherein the first electrode is a cathode.   The electrolyzed water generating apparatus carrying the electrolysis unit of the said Claim 7 or 8.

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