Bubble generating electrode and surface forming method for bubble generating electrode

Abstract

Provided is an electrode for bubble generation, whereby clouding bubbles can be efficiently generated even other than on the periphery of a through hole penetrating through an electrode plate. The present invention has a recess group comprising a plurality of recesses in the surface thereof, and is configured so that the root-mean-square height Rq in the same recess is 1.5-20.0 µm. The present invention is also characterized in that the recesses are linear recessed grooves, the recess group being constituted from a plurality of recessed grooves each extending in substantially the same direction, or in that the recesses are linear recessed grooves, the recess group being constituted from a plurality of first recessed grooves which extend in the first direction and are substantially parallel to each other, and a plurality of second recessed grooves which extend in a second direction crossing the first direction and are substantially parallel to each other.

Description

[Technical field]

[0001] The present invention relates to a bubble-generating electrode and a method for forming a surface of the bubble-generating electrode. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there has been known an apparatus that generates hydrogen, oxygen, and a gas corresponding to an additive by electrolysis of water and adds the gas to water to generate electrolyzed water (hereinafter, referred to as an electrolyzed water generating apparatus).

[0003] The electrolytic water generating device has built-in electrodes for electrolyzing water. For example, in the case of an electrolytic hydrogen water generating device that contains hydrogen, the hydrogen generated on the surface of the cathode is diffused and dissolved in the water to generate electrolytic hydrogen water.

[0004] It has been reported that electrolyzed hydrogen water reduces oxidative stress in the body and inhibits increases in blood LDL levels, and it is expected that the generated electrolyzed hydrogen water, if used for drinking or bathing, will help improve the health of users.

[0005] Therefore, many users of electrolytic hydrogen water generating devices are very health conscious, and one of their biggest concerns is how much hydrogen is contained in the electrolytic hydrogen water they use.

[0006] Therefore, in order to obtain high user satisfaction, it is important that the dissolved hydrogen concentration in the generated electrolytic hydrogen water is high when it is measured.

[0007] However, the more frequently a person uses an electrolytic hydrogen water generating device, the more cumbersome it becomes to measure the hydrogen concentration every time, which is difficult to say is realistic.

[0008] In response to this, the inventors believed that visually indicating the generation of a large amount of hydrogen bubbles would serve as an indication of a high concentration of dissolved or dispersed hydrogen, and would therefore contribute greatly to user satisfaction.

[0009] In particular, among the various electrolyzed hydrogen water generators, electrolyzed hydrogen water generators of the type in which the device itself is immersed in stored water, such as bath water in a bathtub, and used in a bottom-mounted or floating state (hereinafter also referred to as submersible type devices), and electrolyzed hydrogen water generators of the type in which water is stored in a water storage space within the device and electrolyzed to generate electrolyzed hydrogen water, such as electrolyzed hydrogen water generators equipped with an electrolysis function in a water bottle or kettle (hereinafter also referred to as water storage type devices), are types of electrolyzed hydrogen water generators in which the water to be electrolyzed is still water and which are suitable for the user to visually check for hydrogen bubbles.

[0010] The inventors previously discovered that it is possible to generate bubbles by forming a sharp-pointed charge concentration area around the periphery of the through-hole portion (air bubble passage hole) of a punched metal electrode plate, and proposed an electrode structure as an example of the use of an underwater immersion type device (see Patent Document 1).

[0011] The electrode with the structure disclosed in Patent Document 1 generates extremely distinctive bubbles. That is, the disclosed electrode is specialized for generating cloudy hydrogen bubbles (about 0.1 to 100 μm, hereinafter simply referred to as cloudy bubbles) that float in water like smoke, rather than small bubbles with a diameter of less than 0.1 μm that are difficult to see with the naked eye and have excellent dissolution efficiency, or large bubbles with a diameter of more than 100 μm and excellent visibility that makes it possible to recognize them as gas.

[0012] Furthermore, an electrode with this structure overcomes the problems of not being able to obtain the visual effect of small bubbles and of large bubbles having an extremely short residence time in water and poor dissolution efficiency, by allowing the bubbles to float in the water for a relatively long period of time like smoke, while producing the extremely distinctive visual effect of a cloudy white appearance, thereby creating a third new bubble form and inducing a great sense of satisfaction in the user. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] JP 2017-205749 A Summary of the Invention [Problem to be solved by the invention]

[0014] However, the above-mentioned Patent Document 1 merely discloses a structure capable of generating cloudy bubbles, and does not propose any technology from the viewpoint of how to efficiently generate cloudy bubbles.

[0015] That is, although the above-mentioned Patent Document 1 discloses that milky bubbles can be generated from the peripheral parts of the bubble passage holes that penetrate the electrode plate, if one were to aim to increase the efficiency of milky bubble generation based on this, it would be necessary to form through-holes all over the electrode plate, which would reduce the opposing area and, as a result, would reduce the efficiency of milky bubble generation.

[0016] Furthermore, not only in electrolytic hydrogen water generating devices one of whose purposes is to generate hydrogen, but also in electrolytic water generating devices one of whose purposes is to generate a gas other than hydrogen, such as oxygen, visually indicating that a large amount of that gas is being generated and providing the user with an indication of the concentration of the dissolved or dispersed gas contributes to the satisfaction of users who purchase the device with the aim of generating that gas.

[0017] The present invention has been made in consideration of the above circumstances, and provides a bubble-generating electrode that can efficiently generate cloudy bubbles even when not on the periphery of a through hole that penetrates an electrode plate, and a method for forming the surface of a bubble-generating electrode. [Means for solving the problem]

[0018] As mentioned above, if the bubbles generated are too small, they will collapse and disappear in a short time. On the other hand, if the bubbles are large, they will rise to the water surface immediately after generation, and neither of these bubbles will remain floating in the water for a long period of time and turn the water cloudy. The inventors have discovered that the size of the bubbles generated varies depending on the uneven shape of the electrode surface, and have obtained the conditions for a bubble-generating electrode that can generate an abundance of cloudy bubbles that float in the water like smoke. That is, in order to solve the above-mentioned problems of the prior art, the bubble-generating electrode of the present invention has the following features: (1) The present invention comprises a folded electrode in which a plurality of electrode plate sections are overlapped and connected to each other while forming a certain gap by a bridge section bent into a substantially semicircular arc shape, and an intermediate electrode plate interposed in the gap between the folded electrodes, and the folded electrode is provided on both the inner and outer sides thereof. surface teeth The surface has a recess group consisting of a plurality of recesses, and the root mean square height Rq of the recesses on the surface is set to 1.5 to 20.0 μm.

[0019] The bubble-generating electrode according to the present invention also has the following features. (2) A through hole is formed in the electrode plate portion of the folded electrode and / or the intermediate electrode plate, and a sharp-pointed charge concentration portion is formed on the periphery of the through hole. . ( 3 1. The recesses are linear grooves, and the recess group is formed by a plurality of grooves each extending in approximately the same direction. ( 4 ) The recesses are linear grooves, and the recess group is composed of a plurality of first grooves that are approximately parallel to each other and extend in a first direction, and a plurality of second grooves that are approximately parallel to each other and extend in a second direction intersecting the first direction. ( 5 ) The width of the grooves varies randomly in the extension direction. ( 6 1.) The recesses are dot-shaped. ( 7 ) The inner and outer surfaces of the folded electrode are provided with a group of recesses each having a plurality of recesses. Pear-textured To be . ( 8 ) The recesses are wavy grooves, and the recess group has peaks and valleys of the multiple grooves aligned with each other. ( 9 ) said surface is coated with platinum at a coverage of greater than 61%.

[0020] In addition, in the method for forming a surface of a bubble generating electrode according to the present invention, 10 ) A method for forming a surface of a bubble generating electrode, comprising the steps of: The bubble generating electrode includes a folded electrode in which a bridge portion of an electrode plate assembly is connected to a plurality of electrode plate portions and the bridge portion is bent into a substantially semicircular arc shape to overlap the plurality of electrode plate portions while forming a certain gap, and an intermediate electrode plate is interposed in the gap of the folded electrode, and both inner and outer surfaces of the folded electrode are formed into a matte finish having a group of recesses consisting of a plurality of recesses. The electrode plate assembly is The above-mentioned is obtained by etching. Inside and outside table Face The area was then treated with a matte finish. Under conditions where both the inner and outer surfaces are smoothed, After blasting, the root mean square height Rq of the same area was measured. While making it smaller The thickness was set to 1.5 to 20.0 μm. Effect of the Invention

[0022] According to the present invention, The present invention comprises a folded electrode in which a plurality of electrode plate sections are overlapped and connected to each other while forming a certain gap by a bridge section bent into a substantially semicircular arc shape, and an intermediate electrode plate interposed in the gap between the folded electrodes, and the folded electrode is provided on both the inner and outer sides thereof. surface teeth By having a group of recesses consisting of a plurality of recesses and setting the root mean square height Rq of the surface due to the recesses to 1.5 to 20.0 μm, it is possible to provide a bubble-generating electrode that can efficiently generate cloudy bubbles even when not on the periphery of a through-hole penetrating the electrode plate.

[0023] Furthermore, if the recesses are linear grooves and the recess group is configured by extending a plurality of grooves in approximately the same direction, it is possible to efficiently generate opaque bubbles, and a bubble generating electrode having a plurality of linear patterns aligned in the same direction can be obtained. Furthermore, if the recess group is configured by extending a plurality of grooves in approximately the same direction, bubbles can grow along the extension direction when they are generated, and can expand smoothly, which can also promote the growth of the bubbles.

[0024] Furthermore, if the recesses are linear grooves and the recess group is composed of a plurality of first grooves extending in a first direction and substantially parallel to each other, and a plurality of second grooves extending in a second direction intersecting the first direction and substantially parallel to each other, then it is possible to provide a bubble generating electrode having a surface design in which a plurality of linear patterns aligned in the same direction toward the first direction intersect with a plurality of linear patterns aligned in the same direction toward the second direction. In addition, in a configuration having such intersecting linear grooves, when bubbles grow, the bubbles grow in the direction in which the grooves extend, and can also grow in an expanding direction toward the intersecting grooves, thereby further promoting the growth of the bubbles.

[0025] In addition, if the width of the grooves is randomly changed in the extension direction, it is possible to efficiently generate cloudy bubbles, and the sharpened edge of the randomly changing width can function as a charge concentration area, which can promote bubble generation from the same area. In addition, the grooves have a randomly changing width in the extension direction, which causes the bubbles generated to have a distribution in size, and it is possible to create a texture in which small bubbles that float for a long time and bubbles that rise to the surface in a relatively short time are mixed.

[0026] Furthermore, if the recesses are dot-shaped, it is possible to efficiently generate opaque bubbles, and the bubble generating electrode can have a dot-like pattern. By forming the dots to be approximately uniform in size, it is possible to make the size of the bubbles escaping from the electrode surface approximately uniform to a predetermined size.

[0027] Furthermore, if the recesses are formed in a matte finish, it is possible to efficiently generate opaque bubbles, and to provide a bubble generating electrode with a matte finish pattern. By forming the recesses in a matte finish, the recesses can be made to have an indefinite shape with a predetermined width in addition to their size. This allows the size of the bubbles detaching from the electrode surface to have a predetermined distribution, and it is also possible to create an appearance of a mixture of small bubbles that float for a long time and bubbles that rise to the water surface in a relatively short time.

[0028] Furthermore, if the recesses are wavy grooves and the recess group is made by aligning the peaks and valleys of the multiple grooves, it is possible to efficiently generate milky bubbles, and furthermore, to provide a bubble generating electrode having a wavy pattern. Furthermore, the wavy grooves allow bubbles to be generated along them, thereby forming a flow of bubbles that has a wavy, trailing texture.

[0029] Furthermore, if the surface is covered with platinum at a coverage rate of more than 61%, the exposed portion of the substrate made of a metal plate such as titanium or an alloy containing titanium is small, and the bubble generating electrode has excellent durability. In addition, it is possible to prevent an increase in voltage due to the formation of an oxide film on the exposed portion of the substrate such as titanium, and generate milky bubbles with lower power.

[0030] Further, according to the method for forming a surface of a bubble generating electrode according to the present invention, the method for forming a surface of a bubble generating electrode includes the steps of: The bubble generating electrode includes a folded electrode in which a bridge portion of an electrode plate assembly is connected to a plurality of electrode plate portions and the bridge portion is bent into a substantially semicircular arc shape to overlap the plurality of electrode plate portions while forming a certain gap, and an intermediate electrode plate is interposed in the gap of the folded electrode, and both inner and outer surfaces of the folded electrode are formed into a matte finish having a group of recesses consisting of a plurality of recesses. The electrode plate assembly is The above-mentioned is obtained by etching. Inside and outside table Face The area was then treated with a matte finish. Under conditions where both the inner and outer surfaces are smoothed, After blasting, the root mean square height Rq of the same area was measured. While making it smaller Since the thickness is set to 1.5 to 20.0 μm, it is possible to provide a surface formation method for a bubble-generating electrode that can efficiently generate cloudy bubbles even if not on the periphery of a through-hole that penetrates an electrode plate, and in particular, a surface formation method for a bubble-generating electrode that can be controlled to form an electrode surface that has a roughness suitable for generating cloudy bubbles and has sufficient adhesion for a platinum plating film, based on an etched surface.

[0031] Furthermore, if the blasting process is a process for reducing the value of the root mean square height Rq of the matte surface after the etching process, the occurrence rate of cloudy bubbles can be increased. [Brief description of the drawings]

[0032] [Figure 1] FIG. 2 is an explanatory diagram showing a basic configuration of a bubble generating electrode according to the present embodiment. [Diagram 2] FIG. 2 is an explanatory diagram showing a basic configuration of a bubble generating electrode according to the present embodiment. [Diagram 3] FIG. 2 is an explanatory diagram showing a basic configuration of a bubble generating electrode according to the present embodiment. [Figure 4] FIG. 2 is an explanatory diagram showing a surface structure of the bubble-generating electrode according to the first embodiment. [Diagram 5] FIG. 11 is an explanatory diagram showing a surface structure of a bubble-generating electrode according to Example 2. [Figure 6] FIG. 11 is an explanatory diagram showing a surface structure of a bubble-generating electrode according to Example 3. [Figure 7] FIG. 11 is an explanatory diagram showing a surface structure of a bubble-generating electrode according to Example 4. [Figure 8] FIG. 11 is an explanatory diagram showing the surface structure of the bubble-generating electrodes according to Examples 5 and 6. [Figure 9] FIG. 11 is an explanatory diagram showing the surface structure of the bubble-generating electrodes according to Examples 7 and 8. [Figure 10] FIG. 13 is an explanatory diagram showing the surface structure of the bubble-generating electrodes according to Examples 9 and 10. [Figure 11] FIG. 13 is an explanatory diagram showing the surface structure of the bubble-generating electrodes according to Examples 11 and 12. [Figure 12] FIG. 21 is an explanatory diagram showing the surface structure of a bubble-generating electrode according to Example 13. [Figure 13] FIG. 21 is an explanatory diagram showing the surface structure of a bubble-generating electrode according to Example 14. [Figure 14] FIG. 21 is an explanatory diagram showing the surface structure of a bubble-generating electrode according to Example 15. [Figure 15] FIG. 21 is an explanatory diagram showing the surface structure of a bubble-generating electrode according to Example 16. [Figure 16] FIG. 21 is an explanatory diagram showing the surface structure of a bubble-generating electrode according to Example 17. [Figure 17] FIG. 2 is an explanatory diagram showing the test contents of a cloudy bubble generation test. [Figure 18] FIG. 2 is an explanatory diagram showing the test contents of a cloudy bubble generation test. [Figure 19] 1 shows microscopic images of the surfaces of each bubble-generating electrode formed by a combination of etching and blasting. [Figure 20] FIG. 13 is a diagram showing the root mean square height (Rq) on the surface of each bubble-generating electrode formed by a combination of etching and blasting. [Figure 21] FIG. 1 is a schematic diagram of a typical bubble-generating electrode surface formed by a combination of etching and blasting. [Figure 22]13 shows the evaluation results of the state of bubble generation in each bubble generating electrode formed by each combination of etching and blasting. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] The present invention relates to a bubble-generating electrode, and in particular to provide a bubble-generating electrode that can efficiently generate cloudy bubbles even when not at the periphery of a through-hole penetrating an electrode plate.

[0034] As mentioned above, several electrodes have been proposed so far for the sole purpose of efficiently generating bubbles.

[0035] However, apart from the previous application filed by the present inventors, no proposal has yet been made that specifically targets the generation of milky bubbles (opaque bubbles) that float in water for a relatively long period of time, like smoke.

[0036] Therefore, the bubble generating electrode according to this embodiment has a recess group consisting of a plurality of recesses on its surface, and the root mean square height Rq of the recesses on the surface is 1.5 to 20.0 μm, so that opaque bubbles can be efficiently generated on the entire surface of the electrode plate, not just on the periphery of the through-hole. Note that the through-hole may be present in the electrode plate, and does not prevent the formation of the through-hole in the electrode plate.

[0037] Here, the recesses formed on the electrode surface may be grooves or may be dots.

[0038] The shape of the grooves is not particularly limited, and may be linear, curved, or wavy. In this case, the group of recesses, which is a collection of multiple grooves, may have a structure in which all the straight lines extend in approximately the same direction, such as a structure similar to a metal surface that has been subjected to hairline processing.

[0039] The width of the groove may be varied randomly, so that the sharpened edge of the varying width can function as a charge concentration area, promoting bubble generation from the area.

[0040] Also, the recesses may be of an irregular shape and may form a matte finish as a group of recesses.

[0041] Furthermore, if the surface is covered with platinum at a coverage of 61% or more, more preferably at a coverage of 66% or more, the exposed portion of the substrate can be reduced, thereby reducing the power required for electrolysis, and the generation of cloudy bubbles due to the recesses can be further promoted. Also, the bubble generating electrode can have excellent durability.

[0042] The gas components constituting the cloudy bubbles are not particularly limited, and may include, for example, gases generated by electrolysis of water, such as hydrogen, oxygen, ozone, or gases corresponding to the solutes in the water to be electrolyzed, such as chlorine when saline water is being electrolyzed, or may include a combination of these.

[0043] Below, regarding the bubble generating electrode according to this embodiment, first the electrode body structure common to each electrode will be explained with reference to the drawings, and then 20 examples each having a different recess structure on the surface will be explained.

[0044] [1. Electrode body structure] Fig. 1 is an explanatory diagram showing the appearance of the bubble-generating electrode B according to this embodiment, which employs a so-called folded electrode A. As shown in Fig. 1, the bubble-generating electrode B includes an electrode laminate 10 and two conductive rods 11a and 11b extending from the electrode laminate 10. By applying voltages with relatively different potentials to the conductive rods 11a and 11b, water in contact with the electrode laminate 10 is electrolyzed, and opaque bubbles can be generated by the surface structure shown in each of Examples 1 to 20 described later.

[0045] The electrode laminated section 10 is composed of folded electrodes A and interposed electrode plates 12 interposed in the gaps between the folded electrodes A, and has a structure in which a plurality of plate-shaped electrode plates (three in the case of the bubble generating electrode B according to this embodiment) are stacked with a certain gap therebetween. In particular, in this embodiment, the gap between the electrodes of the electrode laminated section 10 is set to 0.3 to 1.0 mm, forming a narrow electrode body with excellent electrolysis efficiency.

[0046] 2(a), the intermediate electrode plate 12 is a metal plate having substantially the same shape (substantially rectangular in plan view) as the electrode plate portion 14 of the folded electrode A described later, and functions as a counter electrode of the folded electrode A. Although this is an optional configuration, the intermediate electrode plate 12 has a plurality of elongated holes 12a formed therein, which are configured to facilitate the introduction of water between the electrode plates. In addition, a conductive rod 11b is connected to the intermediate electrode plate 12, as shown by the dashed line.

[0047] In addition, although this is also an optional configuration, when the intermediate electrode plate 12 is used as a cathode (hydrogen generation electrode), a sharp-pointed charge concentration portion may be provided on the periphery of the hole 12a, and hydrogen bubbles that appear as opaque clouds may be generated by concentrating electric charge on the charge concentration portion and partially promoting electrolysis. The charge concentration portion can be formed, for example, by punching the titanium substrate used as the material for forming the intermediate electrode plate 12 and making the perforated edges sharp.

[0048] On the other hand, the folded electrode A shown in Fig. 1 is formed by bending the electrode plate connector 13 shown in Fig. 2(b). The electrode plate connector 13 is obtained by punching or the like from a single metal flat plate, and includes a plurality of electrode plate sections 14 (two in this embodiment) and bridging sections 15 that electrically connect the electrode plate sections 14. The folded electrode A is formed by bending the electrode plate connector 13 along a line that crosses each bridging section 15, which is indicated by a dashed line.

[0049] The electrode plate portion 14 is a portion that functions as an electrode plate that is the counter electrode of the interposed electrode plate 12 and exerts the electrolytic function of the folded electrode A. Although this is an optional configuration, the folded electrode A according to this embodiment also has a plurality of elongated holes 14a formed in the electrode plate portion 14 that extend in the connection direction of the electrode plate portion 14 (the up-down direction in FIG. 2(a)), so that water can be easily introduced between the electrode plates.

[0050] In addition, although this is also an optional configuration like the above-mentioned intermediate electrode plate 12, when the folded electrode A is used as a cathode (hydrogen generation electrode), a sharp-pointed charge concentration portion may be provided on the periphery of the hole 14a, and the charge may be concentrated on the charge concentration portion to partially promote electrolysis, thereby generating hydrogen bubbles that are visually recognized as cloudy. The charge concentration portion can be formed, for example, by punching the titanium substrate used as the material for forming the electrode plate portion 14 and making the perforated edge portion sharp.

[0051] In addition, a conductive rod 11a is connected to the electrode plate portion 14 as shown by the dashed line, making it possible to supply a current at a predetermined voltage to the folded electrode A. The conductive rod 11a may be attached to the electrode plate portion 14 before the electrode plate connecting body 13 is folded, or it may be attached after folding.

[0052] The bridge portion 15 is a portion for electrically connecting the electrode plate portions 14 and forming an integrated structure. In particular, as shown in FIG. 1, a feature of the folded electrode A in this embodiment is that the bent structure formed in the bridge portion 15 is substantially semicircular. The number of bridge portions 15 is not particularly limited, and may be a single bridge portion, but multiple bridge portions may be provided as shown in FIG. 2(b). When multiple bridge portions 15 are provided, when the electrode plate connector 13 is bent to form a folded electrode, a parallel electrode plate structure, or a laminated electrode pair, it is easy to accurately ensure the parallelism between the electrode plates, and the structural strength can also be increased, which is preferable.

[0053] Fig. 3 is an explanatory diagram showing a schematic cross section of the bubble-generating electrode B in Fig. 1 taken along the line P1-P1. For convenience of explanation, the distance, thickness, positional relationship, detailed configuration, etc. between the folded electrode A and the interposed electrode plate 12 may be partially omitted or exaggerated, and the same applies to other drawings. When forming the folded electrode A, the bridging portion 15 is folded along the folding line shown on the electrode plate connector 13 in Fig. 2(b), and at this time, a substantially semicircular arc-shaped bent structure is formed in the bridging portion 15 as shown in Fig. 3.

[0054] By adopting such a configuration, the bending operation can be made extremely simple without the need for the complicated operation of bending the two roots of the bridge portion at right angles with high accuracy as in the conventional folded electrode. The bent structure can be formed by pressing or the like in addition to bending. The bent structure is typically a natural bent structure formed by bending, and therefore the bent structure does not need to be an accurate semicircular arc shape. The electrode plate parts 14 and the intermediate electrode plate 12 of the folded electrode A can have a plate thickness of, for example, 0.1 mm to 1.0 mm, more preferably 0.2 mm to 0.5 mm, and can be made of, for example, a platinum-plated titanium plate. Plating with platinum may be performed after punching the titanium plate, or punching may be performed on the plated titanium plate.

[0055] The bubble-generating electrodes shown in the embodiments described below have the above-mentioned body structure as a common structure, and when an electric current is passed through them while they are in contact with water, hydrogen, oxygen, and other gases are generated as cloudy bubbles from the surface structure shown in each embodiment of the intermediate electrode plate 12 or electrode plate portion 14, which serves as the cathode or anode.

[0056] [2.Surface structure] Next, the surface structure of the bubble generating electrode B described above will be further described with reference to each embodiment. In the following, the folded electrode A will be described as a cathode (hydrogen generating electrode) and the interposed electrode plate 12 as an anode (oxygen generating electrode), but the present invention is not limited thereto. In addition, when describing the structure of the bubble generating electrode B, the vertical direction when the electrode is placed in water will be referred to as the up-down direction, the longitudinal direction of the bubble generating electrode B will be referred to as the left-right direction, and the stacking direction will be referred to as the thickness direction. In each of the present embodiments, the up-down direction of the paper in the front view shown in FIG. 4(a) will be described as the up-down direction, the left-right direction of the paper will be referred to as the left-right direction, and the depth direction of the paper will be referred to as the thickness direction. In addition, it should be noted that the surface structure shown on the drawing is not necessarily accurately shown in terms of the formation density and size of the recesses per unit area, the interval and shape of the recessed grooves, etc., but is shown schematically as necessary in the scratch lines, matte finish, and other surface structures to facilitate understanding of the invention.

[0057] In addition, the surface structure mentioned in each of the following examples can be formed on only one of the electrodes, but may be formed on both electrodes. For example, the bubble generating electrodes B1 to B20 described below are electrodes that are attached to a bath hydrogen generating device F (see FIG. 17) described later for the main purpose of generating hydrogen, and the surface structure can be formed not only on the hydrogen generating electrode (cathode; in this embodiment, the folded electrode A) but also on the oxygen generating electrode (anode; in this embodiment, the interposed electrode plate 12). With this configuration, in addition to the cloudy hydrogen bubbles generated by the hydrogen generating electrode, cloudy oxygen bubbles can be generated from the oxygen generating electrode, and more cloudy bubbles can be visually recognized by the user, thereby further enhancing the visual effect described above.

[0058] (2-1) Example 1 4(a) shows a front view of the bubble-generating electrode B1 according to Example 1. The bubble-generating electrode B1 is composed of a folded electrode A1 and an interposed electrode plate 12 interposed between the folded electrode A1.

[0059] The bubble generating electrode B1 has a surface of the electrode plate portion 14 of the folded electrode A1 functioning as a cathode (hydrogen generating electrode), and has a plurality of linear grooves formed approximately parallel to each other as recesses extending in the vertical direction on the surface facing the intermediate electrode plate 12 (hereinafter simply referred to as the inner surface of the folded electrode A1) and the surface not facing the intermediate electrode plate 12 (hereinafter simply referred to as the outer surface of the folded electrode A1), and the group of grooves gives the electrode a so-called hairline finish. For ease of explanation, the surfaces subjected to this finish are referred to as upper and lower hairline surfaces T1.

[0060] 4(b) shows a microscopic image (×160) of the upper and lower hairline surfaces T1. The upper and lower hairline surfaces T1 can be formed by polishing the inner and outer surfaces of the folded electrode A1 with a wire brush wheel or a hairline polishing wheel.

[0061] This polishing can be performed on inner and outer surfaces that have already been platinum plated (post-processing), or it is also possible to polish inner and outer surfaces that have not been platinum plated and then platinum plate them to form the bubble-generating electrode B1 (pre-processing). In particular, if the inner and outer surfaces including the upper and lower hairline surfaces T1 are plated with platinum at a coverage rate of more than 61%, it is possible to form a bubble-generating electrode B1 that is extremely durable while being capable of generating milky bubbles at low power.

[0062] In the bubble generating electrode B1 of this embodiment, both the inner and outer surfaces of the folded electrode A1 are made into upper and lower hairline surfaces T1, but only the inner surface facing the interposed electrode plate 12, which serves as the anode, may be made into the upper and lower hairline surfaces T1.

[0063] In other words, since the outer surface does not face the interposed electrode plate 12 and therefore contributes little to the generation of hydrogen bubbles, not making the outer surface the upper and lower hairline surfaces T1 is advantageous in terms of reducing the amount of work required in the manufacturing process of the bubble generating electrode B1.

[0064] However, as in this embodiment, by forming both the inner and outer surfaces of the folded electrode A1 into upper and lower hairline surfaces T1, it is possible to prevent warping of the electrode plate portion 14 due to polishing. This is extremely useful in preventing short circuits caused by contact between the electrode plate portion 14 and the interposed electrode plate 12 and in performing uniform electrolysis, particularly in narrow laminated electrodes such as the bubble generating electrode B. This configuration is similar in the following embodiments.

[0065] The root mean square height of the upper and lower hairline surfaces T1 of the bubble generating electrode B1 according to this embodiment was calculated to be Rq = 3.41. In addition, since the polishing process was a pre-processing process, the platinum coverage rate was 100%.

[0066] (2-2) Example 2 5(a) shows a front view of the bubble-generating electrode B2 according to Example 2. The bubble-generating electrode B2 is composed of a folded electrode A2 and an interposed electrode plate 12 interposed between the folded electrode A2.

[0067] The bubble generating electrode B2 has a plurality of generally linear grooves (hereinafter also referred to as scratch lines) whose width changes randomly in the extension direction, extending vertically at a predetermined interval, formed generally parallel to each other on the inner and outer surfaces of the folded electrode A2 functioning as a cathode (hydrogen generating electrode), and the grooves are in a scratch line processing state. For convenience of explanation, the surfaces subjected to the processing are referred to as upper and lower scratch line surfaces T2.

[0068] FIG. 5(b) shows a microscopic image (×80) of the upper and lower scratch line surfaces T2. The upper and lower scratch line surfaces T2 can be formed by scratching the inner and outer surfaces of the folded electrode A2 with a sharp tip of a hard metal or mineral. It is also possible to efficiently form a plurality of grooves by scratching the inner and outer surfaces of the folded electrode A2 using a tool such as a saw blade having a plurality of sharp tips. In this embodiment, the line width of the scratch line is approximately 100 to 300 μm, with an average of about 200 μm, and the line spacing is about 1 mm.

[0069] The scribing may be performed before (pre-processing) or after (post-processing) the platinum plating process. The bubble generating electrode B2 according to this embodiment is post-processed.

[0070] In the bubble generating electrode B2 of this embodiment, both the inner and outer surfaces of the folded electrode A2 are made into upper and lower scratch line surfaces T2, but only the inner surface facing the interposed electrode plate 12, which serves as the anode, may be made into the upper and lower scratch line surfaces T2.

[0071] The root mean square height of the upper and lower scratch line surfaces T2 of the bubble generating electrode B2 according to this embodiment was calculated to be Rq = 3.44. In addition, since the scratch processing was a post-processing, the platinum coverage rate was 93%.

[0072] (2-3) Example 3 6 shows a front view of the bubble-generating electrode B3 according to Example 3. The bubble-generating electrode B3 is composed of a folded electrode A3 and an interposed electrode plate 12 interposed between the folded electrode A3.

[0073] The bubble generating electrode B3 has a plurality of linear grooves extending in the left-right direction formed approximately parallel on the inner and outer surfaces of the folded electrode A3 that functions as a cathode (hydrogen generating electrode), and the group of grooves is what is called a hairline finish. For ease of explanation, the surfaces that have been subjected to this finish are referred to as left-right hairline surfaces T3.

[0074] The microscopic images of the left and right hairline surfaces T3, the polishing method, the plating finish, and the formation of only the inner surface are the same as those of the upper and lower hairline surfaces T1 described above, so a description thereof will be omitted.

[0075] The root mean square height of the left and right hairline surfaces T3 of the bubble generating electrode B3 according to this embodiment was calculated to be Rq = 2.77. In addition, since the polishing process was a pre-processing process, the platinum coverage rate was 100%.

[0076] (2-4) Example 4 7 shows a front view of the air bubble-generating electrode B4 according to Example 4. The air bubble-generating electrode B4 is composed of a folded electrode A4 and an interposed electrode plate 12 interposed between the folded electrode A4.

[0077] The bubble generating electrode B4 is formed by forming a plurality of substantially linear scratch lines as recesses extending in the left-right direction at a predetermined interval on the inner and outer surfaces of the folded electrode A4 functioning as a cathode (hydrogen generating electrode), and the scratch line processing is performed by the group of recessed grooves. For convenience of explanation, the processed surfaces are referred to as left-right scratch line surfaces T4.

[0078] The microscopic images of the left and right scratch line surfaces T4, the method of marking, the plating finish, and the formation of only the inner surface are the same as those of the upper and lower scratch line surfaces T2 described above, so the explanation will be omitted.

[0079] The root mean square height of the left and right scratch line surfaces T4 of the bubble generating electrode B4 according to this embodiment was calculated to be Rq = 4.51. In addition, since the scratch processing was a post-processing, the platinum coverage rate was 91%.

[0080] (2-5) Example 5 8(a) shows a front view of the bubble-generating electrode B5 according to Example 5. The bubble-generating electrode B5 is composed of a folded electrode A5 and an interposed electrode plate 12 interposed between the folded electrode A5.

[0081] The bubble generating electrode B5 has a plurality of linear grooves formed in parallel on the inner and outer surfaces of the folded electrode A5 functioning as a cathode (hydrogen generating electrode) as recesses extending in an upward and rightward direction at an inclination of approximately 45 degrees with respect to the vertical direction in a front view, and the group of grooves forms a so-called hairline finish. For convenience of explanation, the surface subjected to the above-mentioned finish is referred to as an obliquely upward and rightward hairline surface T5.

[0082] The microscopic image of the diagonally upward-to-the-right hairline surface T5, the polishing method, the plating finish, and the formation of only the inner surface are the same as those of the upper and lower hairline surfaces T1 described above, so a description thereof will be omitted.

[0083] The root mean square height of the obliquely upward-right hairline surface T5 of the bubble generating electrode B5 according to this embodiment was Rq = 2.52. In addition, since the polishing process was a pre-processing process, the platinum coverage rate was 100%.

[0084] (2-6) Example 6 8(b) shows a front view of the bubble-generating electrode B6 according to Example 6. The bubble-generating electrode B6 is composed of a folded electrode A6 and an interposed electrode plate 12 interposed between the folded electrode A6.

[0085] The bubble generating electrode B6 has a plurality of linear grooves formed in parallel on the inner and outer surfaces of the folded electrode A6 functioning as a cathode (hydrogen generating electrode) as recesses extending in a right downward direction at an inclination of about 45 degrees with respect to the up-down direction when viewed from the front, and the group of grooves is in a so-called hairline processed state. For convenience of explanation, the processed surface is referred to as a diagonally downward right hairline surface T6.

[0086] The microscopic image of the diagonally downward right hairline surface T6, the polishing method, the plating finish, and the formation of only the inner surface are the same as those of the upper and lower hairline surfaces T1 described above, so a description thereof will be omitted.

[0087] The root mean square height of the diagonally downward right hairline surface T6 of the bubble generating electrode B6 according to this embodiment was Rq = 3.07. In addition, since the polishing process was a pre-processing, the platinum coverage rate was 100%.

[0088] (2-7) Example 7 9(a) shows a front view of the bubble-generating electrode B7 according to Example 7. The bubble-generating electrode B7 is composed of a folded electrode A7 and an interposed electrode plate 12 interposed between the folded electrode A7.

[0089] The bubble generating electrode B7 has a plurality of substantially linear scratch lines as recesses formed at a predetermined interval on the inner and outer surfaces of the folded electrode A7 functioning as a cathode (hydrogen generating electrode), extending in an upward and rightward direction at an inclination of approximately 45 degrees with respect to the vertical direction in a front view, and is in a state in which scratch line processing has been performed by this group of recessed grooves. For convenience of explanation, the surface subjected to this processing is referred to as an obliquely upward and rightward scratch line surface T7.

[0090] The microscopic image of the diagonally upward-to-the-right scratch line surface T7, the method of marking, the plating finish, and the formation of only the inner surface are the same as those of the upper and lower scratch line surfaces T2 described above, so a description thereof will be omitted.

[0091] For the bubble generating electrode B7 according to this embodiment, the root mean square height of the diagonally upward-right scratch line surface T7 was calculated to be Rq = 3.92. In addition, since the scratch processing was a post-processing, the platinum coverage rate was 90%.

[0092] (2-8) Example 8 9(b) shows a front view of the bubble-generating electrode B8 according to Example 8. The bubble-generating electrode B8 is composed of a folded electrode A8 and an interposed electrode plate 12 interposed between the folded electrode A8.

[0093] The bubble generating electrode B8 has a plurality of substantially linear scratch lines as recesses formed at a predetermined interval on the inner and outer surfaces of the folded electrode A8 functioning as a cathode (hydrogen generating electrode), extending in a downward right direction at an inclination of approximately 45 degrees with respect to the up-down direction in a front view, and is in a state where scratch line processing is performed by this group of recessed grooves. For convenience of explanation, the surface subjected to this processing is referred to as an obliquely downward right scratch line surface T8.

[0094] The microscopic image of the diagonally downward right scratch line surface T8, the method of marking, the plating finish, and the formation of only the inner surface are the same as those of the upper and lower scratch line surfaces T2 described above, so a description thereof will be omitted.

[0095] For the bubble generating electrode B8 according to this embodiment, the root mean square height of the diagonally downward right scratch line surface T8 was calculated to be Rq = 4.17. In addition, since the scratch processing was a post-processing, the platinum coverage rate was 92%.

[0096] (2-9) Example 9 10(a) shows a front view of a bubble-generating electrode B9 according to Example 9. The bubble-generating electrode B9 is composed of a folded electrode A9 and an interposed electrode plate 12 interposed between the folded electrode A9.

[0097] The bubble generating electrode B9 has a plurality of linear upper and lower grooves (first grooves) formed substantially parallel to each other as recesses extending in the vertical direction as a first direction on the inner and outer surfaces of the folded electrode A9 functioning as a cathode (hydrogen generating electrode), and a plurality of linear left and right grooves (second grooves) formed substantially parallel to each other as recesses extending in the horizontal direction as a second direction intersecting the upper and lower grooves (substantially perpendicular in this embodiment), and these grooves form a cross hairline pattern in the vertical and horizontal directions. For ease of explanation, the surface on which this patterning has been applied is referred to as the vertical and horizontal cross hairline surface T9.

[0098] 10(b) shows a microscopic image (×240) of the vertical and horizontal cross hairline surface T9. The vertical and horizontal cross hairline surface T9 can be formed by polishing the inner and outer surfaces of the folded electrode A9 with a wire brush wheel or a hairline polishing wheel in both the up-down direction as a first direction and the left-right direction as a second direction.

[0099] The plating of the vertical and horizontal cross hairline surfaces T9 and the formation of only the inner surfaces are the same as those of the upper and lower hairline surfaces T1 described above, so the explanation will be omitted.

[0100] The root mean square height of the vertical and horizontal cross hair line surface T9 of the bubble generating electrode B9 according to this embodiment was calculated to be Rq = 1.90. In addition, since the polishing process was a pre-processing process, the platinum coverage rate was 100%.

[0101] (2-10) Example 10 10(c) shows a front view of a bubble-generating electrode B10 according to Example 10. The bubble-generating electrode B10 is composed of a folded electrode A10 and an interposed electrode plate 12 interposed between the folded electrode A10.

[0102] The bubble generating electrode B10 is formed on the inner and outer surfaces of the folded electrode A10 functioning as a cathode (hydrogen generating electrode) with a plurality of straight right-upward grooves (first grooves) extending in a direction that is inclined to the right and upward at an angle of about 45 degrees with respect to the vertical direction when viewed from the front, and a plurality of straight right-downward grooves (second grooves) extending in a direction that is inclined to the right and downward at an angle of about 45 degrees with respect to the vertical direction when viewed from the front, and are formed in parallel to each other, intersecting the right-upward grooves (in this embodiment, perpendicular to them), and a cross hairline processing is performed in an oblique direction by these groove groups. For convenience of explanation, the surface that has been processed is referred to as an oblique cross hairline surface T10.

[0103] The microscopic image of the diagonal cross hairline surface T10, the polishing method, the plating back and forth, the formation of only the inner surface, etc. are the same as those of the vertical and horizontal cross hairline surface T9 described above, so the explanation will be omitted.

[0104] The root mean square height of the oblique cross hairline surface T10 of the bubble generating electrode B10 according to this embodiment was calculated to be Rq = 2.17. In addition, since the polishing process was a pre-processing process, the platinum coverage rate was 100%.

[0105] (2-11) Example 11 11(a) shows a front view of a bubble-generating electrode B11 according to Example 11. The bubble-generating electrode B11 is composed of a folded electrode A11 and an interposed electrode plate 12 interposed between the folded electrode A11.

[0106] The bubble generating electrode B11 has a plurality of linear upper and lower scratch lines (first grooves) formed substantially parallel to each other as recesses extending in the vertical direction as a first direction on the inner and outer surfaces of the folded electrode A11 functioning as a cathode (hydrogen generating electrode), and a plurality of linear left and right scratch lines (second grooves) formed substantially parallel to each other as recesses extending in the horizontal direction as a second direction intersecting the upper and lower scratch lines (substantially perpendicular in this embodiment), and these grooves form cross scratch lines in the vertical and horizontal directions. For convenience of explanation, the surface on which the processing has been performed is referred to as the vertical and horizontal cross scratch line surface T11.

[0107] In the microscopic image of the vertical and horizontal cross scratch line surface T11, in addition to the scratch lines of the upper and lower scratch line surface T2 shown in Figure 5 (b), an image in which scratch lines in the left and right directions are added is observed. Note that the method of scribing, the plating back and forth, the formation of only the inner surface, etc. are the same as those of the upper and lower scratch line surface T2 described above, so explanations are omitted here.

[0108] The root mean square height of the longitudinal and transverse cross scratch line surface T11 of the bubble generating electrode B11 according to this embodiment was calculated to be Rq = 3.23. In addition, since the scratch processing was a post-processing, the platinum coverage rate was 83%.

[0109] (2-12) Example 12 11(b) shows a front view of a bubble-generating electrode B12 according to Example 12. The bubble-generating electrode B12 is composed of a folded electrode A12 and an interposed electrode plate 12 interposed between the folded electrode A12.

[0110] The bubble generating electrode B12 is formed on the inner and outer surfaces of the folded electrode A12, which functions as a cathode (hydrogen generating electrode), with a plurality of linear diagonal right-upward scratch lines (first grooves) extending in a right-upward direction (first direction) at an inclination of approximately 45 degrees with respect to the vertical direction in a front view, and a plurality of linear diagonal right-downward scratch lines (second grooves) extending in a right-downward direction (second direction) at an inclination of approximately 45 degrees with respect to the vertical direction in a front view, and are formed approximately parallel to each other, intersecting the diagonal right-upward scratch lines (approximately perpendicular in this embodiment), and a cross scratch line processing is performed in the diagonal direction by these groove groups. For convenience of explanation, the surface subjected to the processing is referred to as the diagonal cross scratch line surface T12.

[0111] The microscopic image of the diagonal cross scratch line surface T12, the method of marking, the plating finish, and the formation of only the inner surface are similar to those of the vertical and horizontal cross scratch line surface T11 described above, so a description thereof will be omitted.

[0112] The root mean square height of the oblique cross scratch line surface T12 of the bubble generating electrode B12 according to this embodiment was calculated to be Rq = 2.82. In addition, since the scratch processing was a post-processing, the platinum coverage rate was 81%.

[0113] (2-13) Example 13 12(a) shows a front view of a bubble-generating electrode B13 according to Example 13. The bubble-generating electrode B13 is composed of a folded electrode A13 and an interposed electrode plate 12 interposed between the folded electrode A13.

[0114] In the bubble generating electrode B13, a plurality of irregularly shaped recesses are formed on the inner and outer surfaces of the folded electrode A13 functioning as a cathode (hydrogen generating electrode), and the recesses are so-called textured. For convenience of explanation, the textured surface is referred to as textured surface T13.

[0115] FIG. 12(b) shows a microscopic image (×160) of the matte surface T13. The matte surface here refers to a surface that has been subjected to a non-directional matte finish (matte finish) in which multiple irregular fine irregularities are uniformly formed on the surface by mechanical or chemical processing, and includes, for example, matte finishes of JIS H 0201 303 and JIS H 0201 304. A typical mechanical processing method for matte finish is a method in which a matte uneven pattern is transferred to the electrode surface by pressing with a roll-shaped or flat die on which a predetermined uneven pattern is formed. A typical chemical processing method is a so-called etching method in which fine recesses are formed on the surface by immersing the electrode in a liquid that dissolves metals, such as an acid such as hydrochloric acid, sulfuric acid, nitric acid, or hydrofluoric acid.

[0116] This matte finish can be applied to inner and outer surfaces that have already been platinum plated (post-processing), or it can be applied to the inner and outer surfaces of the raw metal plate or electrode plate assembly 13 that has not been platinum plated, and then platinum plating is applied to produce the bubble-generating electrode B13 (pre-processing). In particular, when post-processing is performed, the matte finish is applied so that the platinum plating remains on the inner and outer surfaces including the matte surface T13 at a coverage rate of more than 61%, thereby producing a bubble-generating electrode B13 that is capable of generating milky bubbles at low power and has excellent durability.

[0117] Other than that, the formation of only the inner surface of the matte finish surface T13 and the like are the same as those in the above-described embodiments, and therefore the explanation will be omitted.

[0118] The root mean square height of the matte surface T13 of the bubble generating electrode B13 according to this embodiment was calculated to be Rq = 7.71. In addition, since the matte finish was pre-processed, the platinum coverage was 100%.

[0119] (2-14) Example 14 13(a) shows a front view of a bubble-generating electrode B14 according to Example 14. The bubble-generating electrode B14 is composed of a folded electrode A14 and an interposed electrode plate 12 interposed between the folded electrode A14.

[0120] The bubble generating electrode B14 has a plurality of dot-shaped recesses formed on the inner and outer surfaces of the folded electrode A14 functioning as a cathode (hydrogen generating electrode), and is in a dot-like pattern formed by the recesses. For ease of explanation, the surface to which the recesses have been processed is referred to as a dot surface T14.

[0121] Fig. 13(b) shows a microscopic image (x160) of the dot surface T14. The dot-shaped recesses may be aligned as shown in Fig. 13(a) or may be randomly formed as shown in Fig. 13(b). Typical methods for forming the dot-shaped recesses include a method of forming dents on the inner or outer surface of the folded electrode with a needle-shaped tool such as a hard metal or mineral with a sharp tip or a bundle of such tools, and a method of transferring a predetermined dot-shaped recessed and raised pattern by pressing the surface with a roll-shaped or flat die on which the recessed and raised pattern is formed.

[0122] This dot processing can be performed on inner and outer surfaces that have already been platinum plated (post-processing), or dot processing can be performed on inner and outer surfaces that have not been platinum plated, and then platinum plating can be performed to create the bubble-generating electrode B14 (pre-processing). In particular, when post-processing is performed, the dot processing is performed so that platinum plating remains on the inner and outer surfaces including the dotted surface T14 at a coverage rate of more than 61%, thereby making it possible to create a bubble-generating electrode B14 that is capable of generating milky bubbles at low power while also having excellent durability.

[0123] Other than that, the formation of only the inner surface of the dot surface T14 and the like is the same as in each of the above-mentioned embodiments, so the explanation will be omitted.

[0124] The root mean square height of the dot surface T14 of the bubble generating electrode B14 according to this embodiment was calculated to be Rq = 1.50. In addition, since the dot processing was a post-processing, the platinum coverage rate was 95%.

[0125] (2-15) Example 15 14 shows a front view of a bubble-generating electrode B15 according to Example 15. The bubble-generating electrode B15 is composed of a folded electrode A15 and an interposed electrode plate 12 interposed between the folded electrode A15.

[0126] The bubble generating electrode B15 is formed by forming a plurality of wavy grooves as recesses extending in the vertical direction substantially parallel to each other on the inner and outer surfaces of the folded electrode A15 functioning as a cathode (hydrogen generating electrode), and is in a state in which the recesses are processed to have a concave-convex shape by the group of grooves. For convenience of explanation, the processed surfaces are referred to as upper and lower wavy surfaces T15.

[0127] The uneven processing to form this upper and lower wavy surface T15 can be performed by using a tool similar to a saw blade that has multiple sharp tips spaced at a predetermined interval, and scratching the surface while moving it back and forth perpendicular to the direction of travel to form grooves in the upper and lower wavy surface.

[0128] The plating of the upper and lower wavy line surfaces T15, the formation of only the inner surface, etc. are the same as those of the upper and lower hairline surfaces T1 described above, so the explanation will be omitted.

[0129] The root mean square height of the upper and lower wavy surface T15 of the bubble generating electrode B15 according to this embodiment was calculated to be Rq = 13.2. In addition, since the uneven processing was performed after processing, the platinum coverage rate was 75%.

[0130] (2-16) Example 16 15 shows a front view of a bubble-generating electrode B16 according to Example 16. The bubble-generating electrode B16 is composed of a folded electrode A16 and an interposed electrode plate 12 interposed between the folded electrode A16.

[0131] The bubble generating electrode B16 is formed by forming a plurality of wavy grooves extending in the left-right direction substantially parallel to each other on the inner and outer surfaces of the folded electrode A16 functioning as a cathode (hydrogen generating electrode), and is in a state where the electrode is processed to have a concave-convex shape by the group of grooves. For convenience of explanation, the processed surface is referred to as the left-right wavy surface T16.

[0132] The method of processing the left and right wavy line surfaces T16 into uneven shapes, the plating finish, and the formation of only the inner surface are the same as those of the upper and lower wavy line surfaces T15 described above, so explanations will be omitted.

[0133] The root mean square height of the upper and lower wavy surface T16 of the bubble generating electrode B16 according to this embodiment was calculated to be Rq = 11.7. In addition, since the uneven processing was performed after processing, the platinum coverage rate was 72%.

[0134] (2-17) Example 17 16 shows a front view of a bubble-generating electrode B17 according to Example 17. The bubble-generating electrode B17 is composed of a folded electrode A17 and an interposed electrode plate 12 interposed between the folded electrode A17.

[0135] The bubble generating electrode B17 is a folded electrode A17 that functions as a cathode (hydrogen generating electrode) and has an inner and outer surfaces that are sandblasted to form a plurality of recesses. For ease of explanation, the surface that has been subjected to the sandblasting is referred to as a blasted surface T17.

[0136] The blasted surface T17 can be formed by continuously colliding fine particles for sandblasting against the surface of the metal plate or electrode plate assembly 13 to be processed by using air pressure or the like.

[0137] The plating process of the blasted surface T17, the formation of the inner surface only, etc. are the same as those of the upper and lower hairline surfaces T1 described above, so the explanation will be omitted.

[0138] As for the bubble generating electrode B17 according to this embodiment, the root mean square height of the blasted surface T17 was calculated to be Rq = 4.33. In addition, since the sandblasting was performed as a pre-processing, the platinum coverage rate was 100%.

[0139] (2-18) Example 18 The bubble generating electrode B18 according to the embodiment 18 is composed of a folded electrode A18 and an interposed electrode plate 12 interposed between the folded electrode A18, and like the above-mentioned bubble generating electrode B1, a plurality of linear grooves are formed in parallel as recesses extending in the vertical direction on the inner and outer surfaces of the folded electrode A18 functioning as a cathode (hydrogen generating electrode), and the group of grooves is in a state where a so-called hairline processing is performed, but it is different in that the hairline processing is performed after platinum plating (post-processing). For convenience of explanation, the surface subjected to the processing is referred to as the upper and lower hairline post-processing surface T18.

[0140] The root mean square height of the upper and lower hairline post-processed surfaces T18 of the bubble generating electrode B18 according to this embodiment was calculated to be Rq = 2.68. In addition, since the polishing process was a post-processing, the platinum coverage rate was 61%.

[0141] (2-19) Example 19 The bubble generating electrode B19 according to the embodiment 19 is composed of a folded electrode A19 and an interposed electrode plate 12 interposed between the folded electrode A19, and has a configuration similar to that of the above-mentioned bubble generating electrode B18, but has a different platinum coverage. For convenience of explanation, the surface subjected to the processing is referred to as an upper and lower hairline post-processing surface T19.

[0142] The root mean square height of the upper and lower hairline post-processed surfaces T19 of the bubble generating electrode B19 according to this embodiment was calculated to be Rq = 2.34. In addition, the polishing process was a post-processing process, and the platinum coverage rate was 66%.

[0143] (2-20) Example 20 The bubble generating electrode B20 according to the embodiment 20 is composed of a folded electrode A20 and an interposed electrode plate 12 interposed between the folded electrode A20, and like the above-mentioned bubble generating electrode B1, a plurality of linear grooves as recesses extending in the vertical direction are formed approximately parallel on the inner and outer surfaces of the folded electrode A20 functioning as a cathode (hydrogen generating electrode), and the group of grooves is in a state where a so-called hairline processing is performed. However, it is different in that the processing strength of the hairline processing is strong, that is, the depth of the grooves is made deeper. For convenience of explanation, the surface subjected to the processing is referred to as the upper and lower hairline processing (strong) surface T20.

[0144] For the bubble generating electrode B19 according to this embodiment, the root mean square height of the upper and lower hairline processed (strong) surfaces T20 was calculated to be Rq = 20.0. In addition, since the polishing process was a pre-processing, the platinum coverage rate was 100%.

[0145] [3. Cloudy bubble generation test] Next, a test for generating cloudy bubbles was conducted using the above-mentioned bubble generating electrodes B1 to B20. Specifically, as shown in Fig. 17(a), a bath hydrogen generating device F equipped with the bubble generating electrode B shown in each embodiment was placed in a water tank, and electricity was supplied to generate cloudy bubbles G. The degree of cloudiness was visually observed to confirm the generation status.

[0146] The bath hydrogen generator F is a submersible type device. As shown in Fig. 17(b), it is composed of a main body 20, a lower cover 21, and an upper cover 22. A bubble generating electrode B is attached to the upper surface of the main body 20, and hydrogen bubbles (cloudy bubbles G) can be generated by passing electricity through it. The generated hydrogen is diffused into the water from a diffusion port 22a provided in the upper cover 22.

[0147] This test was performed by submerging the bath hydrogen generator F in 20 L of water (electrical conductivity approximately 150 μS / cm) placed in a water tank at approximately 40°C, and visually observing the electrolysis five minutes after it began.

[0148] Figure 18 is an explanatory diagram of the criteria for visual observation in this test. Figure 18(a) shows the tank 5 minutes after the start of the test. The bubble generating electrode B attached to the hydrogen generator F for bathing efficiently generates cloudy bubbles G, and when viewed from above, the hydrogen generator F is barely observable with the naked eye, even though there is a depth of about 20 cm from the water surface to the top of the hydrogen generator F for bathing. In this test, this state was evaluated as "◎".

[0149] On the other hand, Figure 18(b) shows the tank after 5 minutes from the start of the test, and this bubble generating electrode B, which is different from the above and is attached to the bath hydrogen generator F, is capable of generating cloudy bubbles G, but not very efficiently, and the bath hydrogen generator F can be visually observed from above. In this test, this state was evaluated as "△".

[0150] In addition, although there was more cloudy air bubbles G than in the state "△" of Figure 18(b), visual observation of the bath hydrogen generation device F was not as difficult as in the state "◎" of Figure 18(a), that is, the state roughly halfway between "◎" and "△" was evaluated as "○".

[0151] Moreover, a state in which the amount of opaque bubbles G generated was less than that in the state (△) of FIG. 18(b) was evaluated as "X". Among these evaluations, the bubble-generating electrodes B that were evaluated as "◎" and "○" were determined to be bubble-generating electrodes capable of efficiently generating opaque bubbles. Table 1 shows the test results of the bubble-generating electrodes B1 to B20. [Table 1]

[0152] As can be seen from Table 1, it was confirmed that the bubble-generating electrode B according to this embodiment, i.e., the bubble-generating electrodes B1 to B20 according to Examples 1 to 20, are all bubble-generating electrodes capable of efficiently generating cloudy bubbles.

[0153] In addition, with regard to the root mean square height (Rq), with reference to Example 14, it was confirmed that good generation of turbid air bubbles G was also confirmed at Rq = 1.5, and with reference to Example 20, it was confirmed that good generation of turbid air bubbles G was also confirmed at Rq = 20.0. Therefore, in order to efficiently generate turbid air bubbles G, it was considered that 1.5 ≦ Rq ≦ 20.0 is desirable.

[0154] With regard to the platinum coverage, referring to Example 18, good generation of cloudy bubbles G was confirmed even at a coverage of 61%, and in Example 19 having a similar configuration, even better generation of cloudy bubbles G was confirmed at a coverage of 66%. In addition, in other examples, relatively good generation was confirmed at a coverage of 61% or more and 100% or less. Therefore, in order to efficiently generate cloudy bubbles G, it was considered that the coverage should be 61% to 100%, and taking into consideration the relationship with Examples 18 and 19, it is more preferable to set the platinum coverage to a high level of 66% to 100%.

[0155] In addition, in this test, four comparison electrodes were also subjected to the same test for comparative study. The first one is an electrode that has no recesses formed on the inner and outer surfaces of the folded electrode A. Hereinafter, this electrode is referred to as the normal electrode, and the surface of this electrode is referred to as the normal surface H1.

[0156] The second electrode is a folded electrode A with an Rq value below 1.5, in which the inner and outer surfaces are lightly blasted. Since the blasting is pre-processed, the platinum coverage is 100%. This electrode is called the lightly blasted electrode, and its surface is called the lightly blasted surface H2.

[0157] The third electrode is a folded electrode A with a rough matte finish applied to the inner and outer surfaces, with an Rq value of more than 20. The matte finish is pre-finished, so the platinum coverage is 100%. This electrode is called the rough matte electrode, and its surface is called the rough matte surface H3.

[0158] The fourth is an electrode in which the inner and outer surfaces of the folded electrode A are blasted after plating to reduce the platinum coverage to less than 61%. This electrode is called the blasted electrode and its surface is called the blasted surface H4. Table 2 shows the test results of the comparative electrodes H1 to H4. [Table 2]

[0159] As can be seen from Table 2, in any of Comparative Examples 1 to 4, efficient generation of cloudy bubbles could not be confirmed.

[0160] In particular, the root mean square height is less than 1.5 in Comparative Example 1 and Comparative Example 2, and more than 20.0 in Comparative Example 3, resulting in a decrease in the generation efficiency of the cloudy bubbles G. When the root mean square height Rq is a small value less than 1.5 μm as in Comparative Example 1 and Comparative Example 2, the bubbles generated are too small and collapse in a short time, resulting in their disappearance. On the other hand, when the root mean square height Rq is a large value exceeding 20.0 μm as in Comparative Example 3, the bubbles generated are too large and immediately rise to the water surface, and in either case, it is believed that this is because the bubbles do not float in the water for a long time to cause cloudiness.

[0161] Furthermore, with reference to Comparative Example 4 regarding the platinum coverage rate, at 55%, which is below 61%, there was a large amount of exposed titanium used in the substrate, and the formation of an oxide coating increased the power required for electrolysis and reduced the generation of bubbles, so the generation of cloudy bubbles G was not good.

[0162] [4. Surface formation based on matte surface] Next, the surface formation of the bubble generating electrode based on the above-mentioned matte surface will be described. In the surface treatment such as hairline or scratch shown in the above-mentioned Examples 1 to 8, the formed recesses or recess groups are anisotropically formed with a predetermined directionality (directivity) on the surface of the electrode plate, whereas the surface formed by the matte treatment shown in Example 13 or the blast treatment shown in Example 17 does not have a predetermined directionality and is isotropic. In the bubble generating electrode, such an isotropic surface is an advantageous configuration for generating uniform bubbles, and the matte surface and the blast surface are one of the good bubble generating surfaces.

[0163] Furthermore, among textured surfaces, textured surfaces obtained by etching (hereinafter also referred to as etched textured surfaces) tend to generate more bubbles as the etching depth increases (as the amplitude of the recesses increases).

[0164] Therefore, it can be said that the etched matte surface is a surface in which the amount of bubbles generated can be relatively easily controlled by adjusting the etching treatment time.

[0165] However, increasing the etching depth also leads to an increase in the amount of normal bubbles having a diameter of more than 100 μm.

[0166] Therefore, in this section, we provide a method for forming the surface of a bubble-generating electrode that is controllable so as to form an electrode surface that is based on an etched surface and has a roughness suitable for generating cloudy bubbles, while also having sufficient adhesion for a platinum plating film.

[0167] Such a surface processing method is a surface formation method for a bubble generating electrode having a group of recesses consisting of a plurality of recesses on the surface, in which the group of recesses on the surface is made matte by etching, and then the matte-finished portion is further subjected to blasting to make the root mean square height Rq of the same portion 1.5 to 20.0 μm.

[0168] When titanium or a titanium alloy is used as the material for the bubble-generating electrode, the chemical etching method that can be used is, for example, a method of treating with a hydrofluoric acid-nitric acid mixture, a hydrofluoric acid-hydrogen peroxide mixture, a hydrogen peroxide-aqueous ammonia-ethylenediaminetetraacetic acid (salt) mixture, or a hydrogen peroxide-phosphate mixture, as shown in Japanese Patent No. 4535232.

[0169] Blasting is a method of processing in which blasting material (also called abrasives or media) is sprayed onto an object and collided with it to treat the surface. The blasting material can be metal, slag, natural stone sand, glass, plastic, or plant-based. By selecting the material, shape, and particle size of the blasting material, as well as the blasting conditions, the surface condition, such as roughness, can be controlled according to the desired surface treatment of the object.

[0170] In general, blasting can roughen a surface or reduce unevenness to make it smooth, depending on the conditions. For example, grid-type projection materials with sharp edges can increase the unevenness of the target surface. On the other hand, round, spherical projection materials called shot-type projection materials can smooth the surface by blasting.

[0171] In particular, in this embodiment, round spherical shot-type blasting materials are used in the blasting process, and the root mean square height Rq of the matte surface after etching is reduced.

[0172] By adopting such a configuration, it is possible to further increase the rate at which cloudy bubbles are generated from the etched surface.

[0173] Next, the surface forming method of the bubble generating electrode in this section will be further explained with reference to test results.

[0174] Specifically, an experiment was conducted to form surfaces with various isotropic irregularities by combining the chemical etching used to form the matte surface in Example 13 with the blasting used in Example 17. Conditions for increasing the irregularities were selected for the chemical etching, and conditions for smoothing were selected and combined for the blasting. In this way, several surfaces were formed by isotropic surface treatment processes such as matte finish and blasting, and the relationship with the generation of bubbles and the proportion of cloudy bubbles was investigated.

[0175] The etching process used a solution of 50% hydrofluoric acid:water = 1:50 (volume ratio). The etching time was changed to immersion time of 10, 50, 100, and 200 minutes. In the following explanation, etching for 10 minutes will be indicated as "Et10min", etching for 50 minutes as "Et50min", etching for 100 minutes as "Et100min", and etching for 200 minutes as "Et200min".

[0176] For the blasting treatment, round spherical shot-type projection material was used, and shot blasting processing was performed using silica beads with an average particle size of 50 μm. The blasting treatment time was changed to 0 seconds (no blasting), 20 seconds, 60 seconds, and 120 seconds. In the following explanation, no blasting treatment is indicated as "Bla0sec", 20 seconds of blasting treatment is indicated as "Bla20sec", 60 seconds of blasting treatment is indicated as "Bla60sec", and 120 seconds of blasting treatment is indicated as "Bla120sec".

[0177] We created 16 types of bubble generating electrodes with different surface conditions by combining four different etching times and four different blasting times. All of these electrode plates were etched, blasted, and then platinum-plated. The platinum coverage was 100%.

[0178] Fig. 19 is an explanatory diagram showing the surfaces of the bubble-generating electrodes thus formed. As can be seen from Fig. 19, the longer the etching process time, the greater the roughness of the unevenness becomes, whereas the longer the blasting process time, the smoother the surface becomes.

[0179] In addition, the root mean square height (Rq) was measured as an index of surface roughness that indicates the state of unevenness. The root mean square height (Rq) is a factor that indicates the degree of undulations (herein also referred to as amplitude) in the direction perpendicular to the surface unevenness.

[0180] As shown in Figure 20, as the etching process time increases, Rq increases and the amplitude of the unevenness becomes larger. The unevenness also changes in a relatively sharper direction. In contrast, with blasting, Rq decreases with processing time and the surface becomes smoother.

[0181] Although details are omitted, the average length of the elements (RSm) was measured as a factor expressing the length of the undulations (hereinafter referred to as the period) of the surface unevenness in the in-plane direction of the electrode plate. The values ​​of Rq and RSm showed that it was possible to create electrode surfaces with various combinations of amplitude and period by combining etching and blasting. Specifically, the amplitude and period of the electrode surfaces at the four corners of the matrix of each bubble generating electrode shown in Figure 19, (Et10min, Bla0sec), (Et10min, Bla120sec), (E200min, Bla0sec), and (Et200min, Bla120sec), are shown in Figure 21. In this way, it was shown that it is possible to create an electrode surface with an adjusted amplitude of the undulations in the direction perpendicular to the electrode surface and an adjusted period in the in-plane direction.

[0182] Additionally, the state of bubble generation in each bubble generating electrode was observed and evaluated in the same manner as in [3. Cloudy bubble generation test] above. The results are shown in Figure 22. The value below each evaluation symbol is the Rq value of each surface.

[0183] As shown in Figure 22, in general, the greater the surface roughness, the better the bubble generation. It was confirmed that an Rq value of 1.5 μm or more resulted in good bubble generation. In addition, when deep etching was performed, such as Et100min and Et200min, sufficient bubble generation was confirmed, even when blasting was performed repeatedly, such as Bla20sec and Bla60sec, as with Bla0sec. As will be described later, blasting can strengthen the adhesion between the titanium substrate and the platinum plating film, so by combining etching and blasting in this way, a bubble generating electrode can be constructed that achieves both bubble generation and adhesion of the platinum plating film.

[0184] Considering the points mentioned in this section, first, etching the surface of the bubble generating electrode increased the generation of bubbles by increasing the roughness of the surface. The blasting treatment that was then performed was performed under conditions that smoothed the surface, and it was found that the generation of bubbles generally decreased.

[0185] That is, in this experiment, the rougher the surface condition of the bubble generating electrode, the better the generation of bubbles.

[0186] However, if the surface roughness is too high, the bubbles that are generated will become too large and will immediately rise to the surface, rather than becoming cloudy bubbles that float in the water for a long period of time.

[0187] Therefore, by combining this smoothing blasting treatment, it is effective to achieve a balance and control so that the surface roughness does not become too high.

[0188] Furthermore, in the blast treatment, it plays an important role in strengthening the adhesive force between the titanium or titanium alloy substrate of the bubble generating electrode and the platinum plating film.

[0189] Therefore, by combining the blasting treatment and the etching treatment, it is possible to control the formation of an electrode surface that has a suitable roughness for generating bubbles and has sufficient adhesive strength for the platinum plating film.

[0190] As described above, the bubble-generating electrode of this embodiment is characterized in that it has a group of recesses consisting of a plurality of recesses on its surface, and the root-mean-square height Rq of the surface due to the recesses is 1.5 to 20.0 μm. Therefore, it is possible to provide a bubble-generating electrode that can efficiently generate cloudy bubbles even if not on the periphery of the through-hole penetrating the electrode plate.

[0191] Furthermore, with the bubble generating electrode according to this embodiment, the rate at which cloudy bubbles are generated can be increased compared to other types of bubbles, allowing the user to visually recognize milky fine bubbles floating in the water like smoke, and visually indicating that a large amount of hydrogen is being released.

[0192] Finally, the above-mentioned embodiments are merely examples of the present invention, and the present invention is not limited to the above-mentioned embodiments. Therefore, even if the above-mentioned embodiments are different, various modifications can be made depending on the design, etc., as long as they do not deviate from the technical idea of ​​the present invention.

[0193] In this embodiment, a folded electrode is used as the bubble generating electrode, but the invention is not limited to this and electrodes of any shape can be used.

[0194] In other words, the present invention is characterized by the surface shape of the electrode rather than the structure of the electrode itself. However, this does not prevent the applicant from claiming the type or structure of the electrode as a constituent element of the present invention when patenting the present invention. [Explanation of symbols]

[0195] 10 Electrode stacking section 11a Continuity rod 11b Continuity rod 12 Interposed electrode plate 12a hole 13 Electrode plate connection body 14 Electrode plate section 14a hole 15 Crosslinked part 20 Main body 21 Lower cover 22 Top cover 22a Diffusion port A Folded electrode A1~A20 Folded electrodes B Bubble generating electrode B1~B20 Bubble generating electrodes F Hydrogen bath generator G. Cloudy bubbles T1~T20 surface

Claims

1. An electrode for generating bubbles, comprising: a folded electrode in which a plurality of electrode plate sections are overlapped and connected while forming a fixed gap by a bridging section bent into an approximately semicircular arc; and an intervening electrode plate interposed in the gap between the folded electrode, wherein both inner and outer surfaces of the folded electrode have a group of recesses consisting of a plurality of recesses, and the root mean square height Rq of the surface due to the recesses is 1.5 to 20.0 μm.

2. The bubble generating electrode according to claim 1, characterized in that a through hole is formed in the electrode plate portion of the folded electrode and / or the intermediate electrode plate, and a sharp-pointed charge concentration portion is formed on the periphery of the through hole.

3. 3. The bubble generating electrode according to claim 1, wherein the recesses are linear grooves, and the recess group is formed by a plurality of grooves each extending in approximately the same direction.

4. The bubble generating electrode according to claim 1 or claim 2, characterized in that the recesses are linear grooves, and the group of recesses is composed of a plurality of first grooves that are approximately parallel to each other and extend in a first direction, and a plurality of second grooves that are approximately parallel to each other and extend in a second direction intersecting the first direction.

5. 5. The bubble generating electrode according to claim 3, wherein the width of the groove varies randomly in the extension direction.

6. 3. The bubble generating electrode according to claim 1, wherein the recess is dot-shaped.

7. An electrode for generating bubbles as described in claim 1 or claim 2, characterized in that both the inner and outer surfaces of the folded electrode are matte-finished with a group of recesses consisting of a plurality of recesses.

8. 3. The bubble generating electrode according to claim 1, wherein the recesses are wavy grooves, and the recess group is formed by aligning peaks and valleys of a plurality of grooves.

9. The bubble generating electrode according to any one of claims 1 to 8, characterized in that the surface is covered with platinum at a coverage rate of more than 61%.

10. A method for forming a surface of a bubble generating electrode, comprising the steps of: The bubble generating electrode includes a folded electrode in which a bridge portion of an electrode plate assembly is connected to a plurality of electrode plate portions and the bridge portion is bent into a substantially semicircular arc shape to overlap the plurality of electrode plate portions while forming a certain gap therebetween, and an intermediate electrode plate is interposed in the gap between the folded electrode, and both inner and outer surfaces of the folded electrode are formed into a matte finish having a group of recesses consisting of a plurality of recesses; The electrode plate connecting body is characterized in that both inner and outer surfaces are made matte by etching, and then the matte-finished areas are blasted under conditions that smooth both inner and outer surfaces, thereby reducing the root mean square height Rq of the areas to 1.5 to 20.0 μm.

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