JP2018095903A - Diamond electrode, method for producing diamond electrode, and electrolyzed water generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a diamond electrode, a method for producing a diamond electrode and an electrolytic water generator suppressing the deformation and cracks of a substrate for an electrode upon diamond vapor deposition and also improved in the generation efficiency of electrolyzed water.SOLUTION: Provided is a diamond electrode obtained by forming boron-doped diamond on the surface of a substrate for a rectangular electrode by vapor deposition. In the substrate for an electrode, a plurality of hole parts passing through both the faces of the substrate for an electrode are formed so as to be drawn up along the longitudinal direction and the transverse direction of the substrate for an electrode. In the substrate for an electrode, the respective hole parts mutually adjacent in the longitudinal direction or in the transverse direction have lines formed at pitch intervals P1, the respective hole parts mutually adjacent in the longitudinal direction or in the transverse direction have lines formed at pitch intervals P2 larger than the pitch intervals P1, and the number of the lines formed at the pitch intervals P1 is greater than the number of the lines formed at the pitch intervals P2.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a diamond electrode, a method for producing a diamond electrode, and an electrolyzed water generating apparatus.

In recent years, ozone water has been widely used for applications such as sterilization of foods and deodorization of malodorous gases, and many examples of knowledge have begun to be published in the fields of medical care and nursing care. Also in the semiconductor manufacturing area, the feature of ozone oxidation with respect to the ultrafine structure is recognized, and the use of ozone water is essential.
As such a method for producing ozone water, the anode electrode is pressed against one surface of the cation exchange membrane, and the raw material water is brought into direct contact with the electrolytic surface of the catalyst electrode formed by pressing the cathode electrode against the other surface. A method using a direct electrolysis method in which ozone water is generated by electrolysis of benzene is known.
The catalyst electrode used in the direct electrolysis method is generally made of platinum, gold, platinum-coated titanium, or the like. However, when the above materials are used, a phenomenon occurs in which the electrodes are consumed and eluted as the raw water is electrolyzed. As a result, since the eluted metal ions adhere to the cation exchange membrane and inhibit the reaction, there is a problem that the generation efficiency of ozone water is lowered.
Moreover, although salt solution was used as raw material water, since impurities generate with ozone generation, it is considered preferable to use pure water or purified water. However, when water with low electrical conductivity, such as pure water or purified water, is used, it is difficult for the electrolysis current to flow through the above-described catalyst electrode made of platinum or the like, and generation of ozone was very small.
Therefore, an autostereoscopic conductive diamond plate formed by a microwave plasma CVD method is used as an anode (see, for example, Patent Document 1), or an anode or cathode in which a diamond thin film is formed on a substrate for electrodes such as titanium by a CVD method. Is known to use.

As described above, when a diamond thin film is formed on an electrode substrate by a CVD method, the electrode substrate is generally porous or mesh-like in terms of ozone water generation efficiency (for example, patents). Reference 2).
However, when a diamond film is deposited on such a porous or mesh-like thin electrode substrate by vapor deposition such as CVD, the electrode substrate is exposed to a high temperature of about 1000 to 1500 ° C., so that the electrode substrate has a bow shape. It sometimes warped or cracked.
In the case of the self-stereoscopic conductive diamond plate, the above deformation and cracking problems do not occur.

JP 2007-44630 A Japanese Patent No. 4970115

  The present invention has been made in view of the above circumstances, and suppresses deformation and cracking of the electrode substrate when the diamond film is formed on the electrode substrate by vapor deposition. It is an object of the present invention to provide a diamond electrode, a method of manufacturing a diamond electrode, and an electrolyzed water generating apparatus that can increase the efficiency of generating electrolyzed water such as water.

In order to solve the above problems, the present inventor, in the process of examining the cause of the above problems, when forming a plurality of holes in the electrode substrate, a row of holes formed at a pitch interval P1, and a pitch Electrode generated at the time of vapor deposition by providing a row of holes formed at a pitch interval P2 larger than the interval P1, and by increasing the number of columns formed at the pitch interval P1 to be greater than the number of columns formed at the pitch interval P2. The present inventors have found that the deformation and cracking of the substrate can be suppressed and the generation efficiency of the electrolyzed water is increased.
That is, the said subject which concerns on this invention is solved by the following means.

1. A diamond electrode formed by vapor-depositing boron-doped diamond on the surface of a rectangular plate electrode substrate,
In the electrode substrate, a plurality of holes penetrating both surfaces of the electrode substrate are formed in alignment along the vertical and horizontal directions of the electrode substrate,
The electrode substrate has a row in which holes adjacent to each other in the vertical direction or the horizontal direction of the electrode substrate are formed at a pitch interval P1, and
The holes adjacent to each other in the vertical direction or the horizontal direction of the electrode substrate have a row formed with a pitch interval P2 larger than the pitch interval P1,
The diamond electrode, wherein the number of rows formed at the pitch interval P1 is larger than the number of rows formed at the pitch interval P2.

  2. 2. The diamond according to claim 1, wherein the row formed at the pitch interval P <b> 2 is located at a central portion within a range of 1 to 15% of the length in the vertical or horizontal direction of the electrode substrate. electrode.

3. The pitch interval P1 is within a range of 0.1 to 10.0 mm,
The said pitch space | interval P2 exists in the range of 0.7-15 mm, The diamond electrode of 1st term | claim or 2nd term | claim characterized by the above-mentioned.

  4). The diameter of the said hole part exists in the range of 0.5-10.0 mm, The diamond electrode as described in any one of Claim 1 to 3 characterized by the above-mentioned.

  5. The diamond electrode according to any one of Items 1 to 4, wherein the hole portion has a trapezoidal shape in a side sectional view in the thickness direction of the electrode substrate.

6). A method for producing a diamond electrode according to any one of items 1 to 5,
When forming a plurality of holes penetrating both surfaces of the electrode substrate in the electrode substrate in alignment along the vertical and horizontal directions of the electrode substrate,
A row in which holes adjacent to each other in the vertical direction or the horizontal direction of the electrode substrate are formed in the electrode substrate at a pitch interval P1,
A row in which holes adjacent to each other in the vertical direction or the horizontal direction of the electrode substrate are formed at a pitch interval P2 larger than the pitch interval P1, and
A method for manufacturing a diamond electrode, wherein the number of rows formed at the pitch interval P1 is larger than the number of rows formed at the pitch interval P2.

  7). An electrolyzed water generating apparatus comprising the diamond electrode according to any one of items 1 to 5.

ADVANTAGE OF THE INVENTION According to this invention, when forming diamond into a film by vapor deposition on the electrode substrate, it can suppress that an electrode substrate warps and deform | transforms or cracks. Moreover, the production efficiency of electrolyzed water can be improved.
The expression mechanism or action mechanism of the effect of the present invention is not clear, but is presumed as follows.
In the present invention, the electrode substrate is provided with a row in which holes adjacent in the vertical direction or the horizontal direction are formed at a pitch interval P1, and a row formed at a pitch interval P2 larger than the pitch interval P1, Since the number of rows formed at the pitch interval P1 is larger than the number of rows formed at the pitch interval P2, when the electrode substrate is exposed to a high temperature atmosphere during vapor deposition, all the pitch intervals P1 are used. Compared with the case of the formed electrode substrate, the row of holes formed at the pitch interval P2 larger than the pitch interval P1 is reinforced, the strength of the electrode substrate is increased, and the bow of the electrode substrate is warped or cracked. It will not be.
In general, as a method for increasing the strength of the electrode substrate, it is conceivable to provide a row in which no hole is formed at all. Rather than forming a row without forming a portion, a row of holes with a large pitch interval (a row formed with a pitch interval P2) is less than a row of hole portions with a small pitch interval (a row formed with a pitch interval P1). However, by forming it to some extent, the generation efficiency of electrolyzed water can be increased while maintaining the strength.

(A) is a top view of the diamond electrode of this invention, (b) is arrow sectional drawing in the XX of (a). It is a modification of this invention and is a top view of a diamond electrode. It is a modification of this invention and is sectional drawing of a diamond electrode. It is the sectional side view which showed the outline of the ozone water production | generation apparatus typically. (A)-(d) is a top view of the diamond electrode of a comparative example, (e) And (f) is a top view of the diamond electrode of this invention.

The diamond electrode of the present invention is a diamond electrode formed by vapor-depositing boron-doped diamond on the surface of a rectangular plate-like electrode substrate, and penetrates both sides of the electrode substrate through the electrode substrate. A plurality of holes are formed in alignment along the vertical and horizontal directions of the electrode substrate, and the electrode substrates are adjacent to each other in the vertical or horizontal direction of the electrode substrate. A row formed with a pitch interval P1 and a row where holes adjacent to each other in the vertical or horizontal direction of the electrode substrate are formed with a pitch interval P2 larger than the pitch interval P1. And the number of columns formed at the pitch interval P1 is larger than the number of columns formed at the pitch interval P2. This feature is a technical feature common to the claimed invention.
As an embodiment of the present invention, from the viewpoint of the effect of the present invention, the rows formed with the pitch interval P2 are within the range of 1 to 15% of the length in the vertical or horizontal direction of the electrode substrate. It is preferable that it is located in the center part from the point which can suppress more effectively the curvature and crack of the electrode substrate at the time of vapor deposition.
It is preferable in terms of strength of the electrode substrate that the pitch interval P1 is in the range of 0.1 to 10.0 mm and the pitch interval P2 is in the range of 0.7 to 15 mm.
The diameter of the hole is preferably in the range of 0.5 to 10.0 mm from the viewpoint of increasing the efficiency of electrolyzed water generation.
It is preferable that the hole portion has a trapezoidal shape in a side sectional view in the thickness direction of the electrode substrate in terms of increasing the surface area of the hole portion and increasing the generation efficiency of electrolyzed water.

In the method for producing a diamond electrode according to the present invention, a plurality of holes penetrating both surfaces of the electrode substrate are formed in the electrode substrate so as to be aligned along the vertical direction and the horizontal direction of the electrode substrate. Further, the electrode substrate is adjacent to each other in a row in which holes adjacent to each other in the vertical or horizontal direction of the electrode substrate are formed at a pitch interval P1, and in the vertical or horizontal direction of the electrode substrate. A row in which the hole portions are formed at a pitch interval P2 larger than the pitch interval P1 is provided, and the number of rows formed at the pitch interval P1 is larger than the number of rows formed at the pitch interval P2. It is characterized by that.
The diamond electrode of this invention is used suitably for an electrolyzed water generating apparatus.

  Hereinafter, the present invention, its components, and modes and modes for carrying out the present invention will be described in detail. In addition, in this application, "-" is used in the meaning which includes the numerical value described before and behind that as a lower limit and an upper limit.

[Diamond electrode]
FIG. 1A is a plan view of the diamond electrode of the present invention, and FIG. 1B is a cross-sectional view taken along line XX in FIG.
The diamond electrode 200 of the present invention is a diamond electrode formed by depositing boron-doped diamond on the surface of a rectangular plate-shaped electrode substrate 201.
The electrode substrate 201 may have a square shape in plan view or a rectangular shape in plan view, but is preferably in a rectangular shape in plan view from the viewpoint of obtaining an effect of preventing warpage. .
In the case of a rectangular shape in plan view, the length in the longitudinal direction of the electrode substrate 201 is preferably in the range of 15 to 750 mm, and the length in the lateral direction is preferably in the range of 10 to 500 mm.
In the case of a square shape in plan view, the length of one side is preferably in the range of 10 to 750 mm.
The thickness of the electrode substrate 201 is preferably in the range of 0.5 to 5.0 mm.

  As the electrode substrate 201, for example, titanium, tungsten, platinum, gold, or a coating metal thereof is preferably used in terms of stability. In particular, the use of a metal in which titanium is coated with platinum is preferable in that the manufacturing cost can be kept low. In addition to metals, bending ceramics can also be used. Furthermore, a silicon wafer is most preferable from the viewpoint of good adhesion in diamond film formation (it can prevent peeling).

In the electrode substrate 201, a plurality of holes 202 penetrating both surfaces of the electrode substrate 201 in the thickness direction are formed in alignment along the vertical direction and the horizontal direction of the electrode substrate 201.
When such a plurality of holes 202 are used as an electrode for generating ozone, the raw water is brought into contact with the cation exchange membrane through the holes 202, and the generated ozone bubbles and hydrogen It becomes a channel through which ions, water, and the like move.
Further, such a plurality of hole portions 202 form a shape that does not adhere so as to completely cover a cation exchange membrane described later. As a result, when the anode electrode (diamond electrode) is pressed against the cation exchange membrane, a portion where the anode electrode is in contact with a portion where the anode electrode is in contact with the cation exchange membrane is generated, so that eddy current is generated when the raw material water flows. Ozone bubbles generated at the anode electrode can be entrained to accelerate dissolution.

  The electrode substrate 201 is adjacent to a row in which holes 202, 202 adjacent to each other in the vertical or horizontal direction of the electrode substrate 201 are formed at a pitch interval P <b> 1 and in the vertical or horizontal direction of the electrode substrate 201. The hole portions 202, 202 to be formed have a row formed with a pitch interval P2 larger than the pitch interval P1. In the present invention, the number of columns formed at the pitch interval P1 is larger than the number of columns formed at the pitch interval P2.

In the present invention, the pitch interval P1 is in the range of 0.1 to 10.0 mm, and the pitch interval P2 is in the range of 0.7 to 15 mm. In terms of surface.
Furthermore, it is preferable that the diameter of the hole 202 is in the range of 0.5 to 10.0 mm from the viewpoint of increasing the efficiency of generating electrolyzed water such as ozone water.

Specifically, for example, in FIG. 1, in the first row in the vertical direction of the electrode substrate 201, seven hole portions 202 are formed at equal intervals with a pitch interval P1 along the horizontal direction. In the second, fourth, and fifth rows in the vertical direction, seven hole portions 202 are formed at equal intervals with a pitch interval P1 along the horizontal direction. On the other hand, in the third row in the vertical direction, four holes 202 are formed at equal intervals with a pitch interval P2 larger than the pitch interval P1 along the horizontal direction.
In the first, third, fifth, and seventh rows from the right in the horizontal direction, five holes 202 are formed at equal intervals in the vertical direction at a pitch interval P1. Note that the holes 202 in the second row, the fourth row, and the sixth row in the horizontal direction are mixed at the intervals P1 and P2, and are not formed at equal intervals.
Thus, in the diamond electrode 200, the number of rows formed at the pitch interval P1 is larger than the number of rows formed at the pitch interval P2. In the case of FIG. 1, the number of columns formed at the pitch interval P1 is eight, and the number of columns formed at the pitch interval P2 is one.

In the case of the diamond electrode 200 shown in FIG. 2, the first row, the third row, and the fifth row in the vertical direction have holes 202 formed at equal intervals along the horizontal direction at a pitch interval P1. In the second row and the fourth row, the holes 202 are formed at equal intervals along the horizontal direction at a pitch interval P2. In the horizontal direction, the first row, the third row, the fifth row, and the seventh row from the right are formed at equal intervals along the vertical direction with the hole portions 202 formed at the pitch interval P1, and the second row, the fourth row. In the sixth row, the holes 202 are formed at equal intervals along the vertical direction at a pitch interval P2.
Also in this diamond electrode 200, the number of rows formed with the pitch interval P1 (7) is larger than the number of rows formed with the pitch interval P2 (5).

In the present invention, in particular, the row formed at the pitch interval P2 is a row located in the center within the range of 1 to 15% of the length of the electrode substrate 201 in the vertical or horizontal direction. However, it is preferable at the point which can suppress more effectively the curvature and the crack of the electrode substrate 201 at the time of vapor deposition.
In the case of FIG. 1, the row formed at the pitch interval P2 is located in the center within the range of 1 to 15% of the length in the vertical direction of the electrode substrate 201, that is, in the third row in the vertical direction. . Note that the row formed at the pitch interval P2 is not limited to the third row in the vertical direction, and may be located at the center within the range of 1 to 15% in the vertical or horizontal direction of the electrode substrate 201. For example, although not shown, the position may be the fourth column from the right in the horizontal direction.

  Furthermore, the number of rows formed at the pitch interval P2 is not limited to one, and may be two or more. In the case of two or more rows, for example, it is preferable to reduce the diameter of the hole 202 and increase the number of the holes 202.

  Further, the hole 202 shown in FIG. 1 is circular in a plan view and rectangular in a side sectional view, but is not limited to this, for example, in a plan view like the hole 203 shown in FIG. It may have a circular shape or a trapezoidal shape in a side sectional view. That is, the diameter of the hole 203 opened on the upper surface of the electrode substrate 201 is larger than the diameter of the hole 203 opened on the lower surface of the electrode substrate 201. By forming the trapezoidal hole 203 in such a side sectional view, the surface area can be made larger than the rectangular hole 202 in the side sectional view as shown in FIG. This is advantageous in the efficiency of electrolyzed water generation. When the hole 203 having a trapezoidal shape in a side sectional view shown in FIG. 3 is formed, it is preferable that the electrode surface having the larger diameter of the hole 203 is disposed on the ion exchange membrane side.

  Further, the shape of the hole 202 can be changed to various other shapes.

  The diamond electrode 200 of the present invention is preferably obtained by depositing boron-doped diamond on the surface of the electrode substrate 201 as described above (at least the surface on the cation exchange membrane side described later). When the diamond electrode 200 of the present invention is used as an electrode for generating electrolyzed water (slightly acidic water, strongly acidic water, alkaline water, etc.), both sides of the electrode substrate 201 are doped with boron. It is preferable that a diamond film is formed.

The doping amount of boron is preferably in the range of 0.1 to 8.0%, more preferably in the range of 1.0 to 5.0% with respect to the carbon of the diamond.
The reason why the boron doping amount is in the range of 0.1 to 8.0% is that when the doping amount is less than 0.1%, the conductivity decreases, for example, generation of ozone or the like decreases. This is because it is theoretically difficult to increase the doping amount to more than 8.0%. By making the boron doping amount in the range of 0.1 to 8.0%, the conductivity is increased and the current efficiency is improved, which is advantageous for ozone generation.

[Diamond Electrode Manufacturing Method]
In the method for producing a diamond electrode according to the present invention, a plurality of holes penetrating both surfaces of the electrode substrate are formed in the electrode substrate so as to be aligned along the vertical direction and the horizontal direction of the electrode substrate. Further, the electrode substrate is adjacent to each other in a row in which holes adjacent to each other in the vertical or horizontal direction of the electrode substrate are formed at a pitch interval P1, and in the vertical or horizontal direction of the electrode substrate. A row in which the hole portions are formed at a pitch interval P2 larger than the pitch interval P1 is provided, and the number of rows formed at the pitch interval P1 is larger than the number of rows formed at the pitch interval P2. It is characterized by that.

  As a method of forming a plurality of holes in the electrode substrate, for example, it can be formed using a laser processing machine.

Examples of a method for forming a boron-doped diamond film include a plasma CVD method and a thermal fermentation CVD method.
In the case of the plasma CVD method, specifically, an electrode substrate is placed in a chamber, hydrogen gas is introduced into the chamber in advance, and plasma is generated by the hydrogen gas. Next, acetone or methane gas or the like as a carbon source, trimethoxyborane or trimethylboron or the like as a boron source is vaporized by bubbling with hydrogen, nitrogen, Ar or the like as a carrier gas, and this raw material gas is Hydrogen gas for plasma generation is introduced into the chamber from a separate line. Thus, a boron-doped diamond film is formed on the electrode substrate disposed in the chamber. The temperature in the chamber is preferably in the range of 1000 to 1500 ° C.

In order to dope boron in the range of 0.1 to 8.0% with respect to the carbon of diamond, the carbon / boron ratio is adjusted by changing the amounts of liquid raw material acetone and trimethoxyborane, The dope amount should be set as follows.
In addition, when doping boron at a high concentration, the liquid raw material is vaporized by bubbling a carrier gas to form a raw material gas, which is then introduced into the chamber. The flow rate of the raw material gas introduced into the chamber at that time Is controlled by, for example, throttling with a needle valve.
Specifically, the conditions for adjusting the doping amount in the range of 0.1 to 8.0% are as follows: plasma output 2500 to 5000 W, chamber internal pressure 110 to 130 Trr, carbon source pressure 2000 to 3500 Pa, film formation time 8 It is preferable that the time be about. The carbon source pressure referred to here is the above-mentioned vaporized source gas (carbon source vaporized by bubbling acetone + trimethoxyborane with a carrier gas (boron source)) introduced into the chamber under the control of a valve. Say the pressure before being done. That is, the pressure of the vaporized carbon source (boron source) before passing through the valve.

The diamond electrode 200 of the present invention can be applied to an electrolyzed water generator. As an example of the electrolyzed water generating device, an ozone water generating device that generates ozone water, a hydrogen water generating device that generates hydrogen water, a device that generates strongly acidic electrolyzed water, a device that generates alkaline electrolyzed water, and a weakly acidic electrolyzed water Examples thereof include a device for generating, a device for generating slightly acidic electrolyzed water, a device for generating electrolytic hyposulfite, and a device for generating alkaline ionized water.
Below, the case where the diamond electrode 200 of this invention is applied to an ozone water production | generation apparatus is demonstrated.

[Ozone water generator]
The ozone water generator includes the diamond electrode of the present invention described above.
FIG. 4 is a side sectional view schematically showing an outline of the ozone water generating apparatus.
The ozone water generating apparatus 100 is configured by arranging a catalyst electrode 2 in a casing 1 to which raw water is supplied.
The catalyst electrode 2 includes a cation exchange membrane 21, an anode electrode 22 that is in pressure contact with one surface of the cation exchange membrane 21, and a cathode electrode 23 that is in pressure contact with the other surface. Then, by applying a DC voltage between the anode electrode 22 and the cathode electrode 23 of the catalyst electrode 2, ozone bubbles are generated on the anode electrode 22 side, and ozone water is generated by dissolving the ozone bubbles in the raw material water. The present invention is a direct electrolysis type ozone water generator.

The casing 1 is composed of a first housing 13 and a second housing 14 that are arranged to face each other.
The first casing 13 and the second casing 14 have a plate shape, and recesses 131 and 141 are formed on opposing surfaces facing each other. The housing chamber 3 is formed by making the concave portions 131 and 141 of the first housing 13 and the second housing 14 face each other. A catalyst electrode 2 is accommodated in the accommodating chamber 3.
Supply channels 11 a and 11 b for supplying raw water into the storage chamber 3 are formed on the lower surfaces of the first casing 13 and the second casing 14, and the first casing 13 and the second casing 14 Discharge passages 12a and 12b are formed on the upper surface for discharging ozone water on the anode electrode 22 side and cathode water on the cathode electrode 23 side generated in the storage chamber 3.
A cation exchange membrane 21 is sandwiched between the opposing surfaces of the first housing 13 and the second housing 14. That is, the outer periphery of the cation exchange membrane 21 is held and fixed by the first housing 13 and the second housing 14.
An anode electrode 22 is provided on the surface of the cation exchange membrane 21 on the first housing 13 side, and a cathode electrode 23 is provided on the surface of the second housing 14 side. Further, the holding plate 15 is disposed on the surface of the anode electrode 22 opposite to the cation exchange membrane 21, and the holding plate 16 is disposed on the surface of the cathode electrode 23 opposite to the cation exchange membrane 21. Yes. The holding plate 15 is fitted into the inner wall surface of the first housing 13, and the holding plate 16 is fitted into the inner wall surface of the second housing 14.
The anode electrode 22, the cathode electrode 23, and the cation exchange membrane 21 are appropriately pressed by the holding plate 15 fitted into the first housing 13 and the holding plate 16 fitted into the second housing 14. .
In this way, the interior of the storage chamber 3 is divided into the anode electrode 22 side and the cathode electrode 23 side by the cation exchange membrane 21. Further, the raw water, ozone water, cathode water, and the like are sealed so as not to leak to the outside from between the facing surfaces of the first housing 13 and the second housing 14.

  The raw water is supplied from the supply channels 11a and 11b, and water flows are generated from the supply channels 11a and 11b to the discharge channels 12a and 12b. The raw water supplied from the supply channels 11a and 11b is in continuous contact with the anode electrode 22 and the cathode electrode 23 in the storage chamber 3, respectively.

Next, the catalyst electrode 2 will be described in detail.
As the cation exchange membrane 21, a conventionally known one can be used, and a fluorine-based cation exchange membrane having a high durability against the generated ozone can be used. For example, the thickness is in the range of 100 to 300 μm. preferable.

As the anode electrode 22, the diamond electrode 200 of the present invention described above can be used.
The cathode electrode 23 is also preferably the diamond electrode 200 of the present invention described above. The cathode electrode 23 can be made of titanium, tungsten, platinum, gold, or a coating metal thereof in addition to the diamond electrode of the present invention, and particularly a metal in which titanium is coated with platinum. If used, the manufacturing cost can be kept low.

The cation exchange membrane 21, the anode electrode 22, and the cathode electrode 23 described above are formed in a flat plate shape to serve as the catalyst electrode 2. The catalyst electrode 2 is held in pressure contact with holding plates 15 and 16 in the casing 1.
Further, the output terminal of the power supply device 80 is electrically connected between the anode electrode 22 and the cathode electrode 23 so that a DC voltage is applied. In other words, the anode electrode 22 and the cathode electrode 23 are connected to the power supply device 80 via the conductive wires 24 to the electrodes 22 and 23. The DC voltage to be applied is preferably in the range of 6 to 15 volts, for example.

The upstream side of the supply channels 11 a and 11 b of the anode electrode 22 and the cathode electrode 23 is connected to the raw water supply unit 60.
Examples of the raw water supply unit 60 include a tank in which raw water is stored and a small pump having a low discharge pressure connected to the tank. Pure water is used as raw material water. The pure water as referred to in the present invention refers to that having a conductivity in the range of 0.5 to 5 μS / cm.

  Although not shown, the supply flow channel 11a and the discharge flow channel 12a on the anode electrode 22 side may be connected by piping to be circulated in a loop. In this way, the pipe can be washed with ozone water. Furthermore, although not shown, the source electrode water may be reused by connecting the supply flow channel 11b and the discharge flow channel 12b in a loop by circulating them in a loop.

A concentration detection sensor 50 that detects the concentration of the ozone water generated on the anode electrode 22 side is provided on the downstream side of the discharge channel 12 a of the anode electrode 22.
As described above, when the supply channel 11a on the anode electrode 22 side and the discharge channel 12a are connected by piping to form a loop shape, the raw water is not limited to the position immediately downstream of the discharge channel 12a. Supply unit 6
It may be provided at a position immediately upstream of 0, may be provided in any of the loop-shaped pipes, and may be provided at a plurality of locations.

The concentration detection sensor 50 is not particularly limited as long as it can measure the concentration of ozone water. For example, the detection electrode (not shown), the comparison electrode (not shown), and these detection electrode and comparison electrode And an ammeter (not shown) that measures the current value by connecting to one of the ends. The concentration detection sensor 50 is a galvanic concentration detection sensor that obtains a current value corresponding to the ozone concentration of ozone water from an electromotive force generated by immersing the comparison electrode and the detection electrode in ozone water.
The ammeter is electrically connected to the control unit 70 of the ozone water generating apparatus 100, and an output value measured by the ammeter is output to the control unit 70.
As the detection electrode, it is preferable to use, for example, an electrode made of platinum or gold, and as the comparison electrode, silver or silver chloride is used.
Such a detection electrode and a comparison electrode are in contact with ozone water flowing through the discharge channel 12a of the anode electrode 22. Then, when the detection electrode and the comparison electrode are in contact with the ozone water, the current value due to the ozone concentration change of the detection electrode is detected and the concentration is measured.

  As a method for measuring the ozone concentration, in addition to the above-described galvanic method, for example, an ultraviolet absorption method for measuring the ozone water concentration from the ultraviolet absorption rate may be used.

Next, a method for generating ozone water using the ozone water generating apparatus 100 having the above-described configuration will be described.
First, raw water (pure water) is supplied into the casing 1 from the supply channels 11 a and 11 b on the anode electrode 22 and cathode electrode 23 side. Then, these raw material waters are brought into continuous contact with each surface of the anode electrode 22 and the cathode electrode 23.
At the same time, a predetermined voltage is applied between the anode electrode 22 and the cathode electrode 23 by driving the power supply device 80. By this energization, the raw water is electrolyzed, and hydrogen in the raw water passes through the cation exchange membrane 21 from the anode electrode 22 side and accelerates and moves to the cathode electrode 23 side. As a result, ozone bubbles are generated on the anode electrode 22 side, and hydrogen bubbles are generated on the cathode electrode 23 side.

Here, on the anode electrode 22 side, the direction of the flow of raw material water is complicated due to slight unevenness of the anode electrode 22 and becomes a vortex. Therefore, on the anode electrode 22 side, the generated ozone bubbles are quickly taken into water and dissolved to generate ozone water, and between the anode electrode 22 and the cation exchange membrane 21 (more precisely, the anode electrode 22 and the cathode electrode). 23), a state where a large amount of current flows is ensured.
When ozone water is generated in this way, the ozone water is discharged to the discharge flow path 12a. On the other hand, on the cathode electrode 23 side, hydrogen bubbles are generated and discharged as hydrogen water (cathode water) from the discharge channel 12b.

  Further, the ozone concentration is measured by the concentration detection sensor 50 during energization. Then, the measured concentration of ozone water is output to the control unit 70, and the control unit 70 adjusts the output of the power supply device 80 so that the output measured concentration becomes a preset concentration. The applied voltage between the anode 32 and the cathode 33 is controlled. Thus, the density | concentration of produced | generated ozone water is maintained by setting density | concentration, a density | concentration fall can be prevented and high concentration ozone water can be produced | generated stably.

The ozone water generating apparatus 100 can be used, for example, in a hand washing apparatus capable of hand washing with ozone water.
Moreover, although the ozone water production | generation apparatus 100 was demonstrated as an example of the electrolyzed water production | generation apparatus of this invention, you may apply to the apparatus which produces | generates each of the following electrolyzed water (functional water). In addition, each electrolyzed water shown below is the pH of electrolyzed water, the electrolysis layer for producing electrolyzed water (two-chamber type (with a diaphragm), one-chamber type (non-diaphragm)), the produced | generated production | generation electrode, and electrolysis It is classified according to the type of liquid.
(1) Strongly acidic electrolyzed water: pH 2.2 to 2.7, a two-chamber type, the production electrode is an anode, and the saline solution is less than 0.2% (2) Alkaline electrolyzed water: pH 11 to 11.5, The two-chamber type cathode is a cathode, the electrolyte solution is less than 0.2% saline (3) weakly acidic electrolyzed water: pH 2.7-5, two-chamber type, the electrolyte solution is less than 0.1% salt Water (4) Slightly acidic electrolyzed water: pH 5 to 6.5, one-chamber type, dilute hydrochloric acid or hydrochloric acid / saline solution with an electrolyzed solution of 2 to 6% Type, saline solution with less than 0.1% electrolyte (6) Alkaline ionized water: pH 8-10, two-chamber type, cathode is produced, electrolyte solution is tap water Therefore, the above electrolyzed water is produced When the diamond electrode 200 of the present invention is used in the apparatus, basically, instead of the raw water used in the ozone water generating apparatus 100 described above. In the case of the one-chamber type, the ion exchange membrane is not provided, and in the case of the two-chamber type, the same configuration as that of the ozone water generating apparatus 100 may be used. In particular, the diamond electrode 200 is preferably formed by depositing diamond doped with boron on both surfaces of the electrode substrate 201.
In addition, as an example of the electrolyzed water generating apparatus, an apparatus for generating hydrogen water may be the same as the ozone water generating apparatus 100 described above. That is, hydrogen water is generated from the cathode side in the ozone water generator 100.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

(1) Example 1
[Production of diamond electrode (1)]
As the electrode substrate 201, a titanium substrate having a size of 80 mm × 80 mm and a thickness of 3.0 mm was prepared. Then, as shown in FIG. 5A, five holes 202 in the vertical direction and the horizontal direction were formed in the electrode substrate 201 at equal intervals with a pitch interval P1 using a laser processing machine. The diameter and pitch interval P1 of the holes 202 are as shown in Table I below.

The electrode substrate in which the hole portion was formed as described above was placed in the chamber, and plasma was generated by introducing hydrogen gas for plasma generation into the chamber. Next, acetone is used as a carbon source, trimethoxyborane is used as a boron source, hydrogen gas is used as a carrier gas, and acetone and trimethoxyborane are bubbled with hydrogen gas as a carrier gas to be vaporized to obtain a raw material gas. Above, the source gas was introduced into the chamber on a separate line from the plasma hydrogen gas. The mixing amount of trimethoxyborane and acetone was adjusted so that the boron doping amount was 3.0%.
In addition, the flow rate of hydrogen gas for generating plasma into the chamber is 532 sccm, the flow rate of source gas into the chamber is 10.8 sccm, the plasma output is 4991 W, the pressure in the chamber is 121.5 Torr, the carbon source pressure is 3061 Pa, and the deposition time is 8 hours. It was.
As a result, a diamond electrode (1) having a boron doping amount of 3.0% with respect to carbon of diamond was obtained on the upper surface of the silicon wafer.

[Production of diamond electrode (2)]
A diamond electrode (2) was produced in the same manner as in the production of the diamond electrode (1) except that the hole pattern was changed to the pattern shown in FIG. 5 (b) instead of FIG. 5 (a). The diameter of the hole, the number of holes, the pitch interval P1, and the pitch interval P2 are as shown in Table I below.

[Production of diamond electrode (3)]
A diamond electrode (3) was produced in the same manner as in the production of the diamond electrode (1) except that the hole pattern was changed to the pattern shown in FIG. 5 (c) instead of FIG. 5 (a). That is, the arrangement pattern shown in FIG. 5C is a pattern in which holes are not formed in diagonal rows extending to the corners through the center of the electrode substrate. The diameter of the hole, the number of holes, the pitch interval P1, and the pitch interval P2 are as shown in Table I below.

[Production of diamond electrode (4)]
A diamond electrode (4) was produced in the same manner as in the production of the diamond electrode (1) except that the hole pattern was changed to the pattern shown in FIG. 5 (d) instead of FIG. 5 (a). That is, the arrangement pattern shown in FIG. 5D is a pattern in which a row in which no hole is formed is provided in the central portion (third row) in the vertical direction of the electrode substrate. The diameter of the hole, the number of holes, the pitch interval P1, and the pitch interval P2 are as shown in Table I below.

[Production of diamond electrode (5)]
In the production of the diamond electrode (1), a diamond electrode (5) was produced in the same manner except that the hole pattern was changed to the pattern shown in FIG. 5 (e) instead of FIG. 5 (a). That is, in the arrangement pattern shown in FIG. 5E, the pitch interval P2 of the holes arranged in the center portion (third row) in the vertical direction of the electrode substrate is set to the other first row, second row, fourth row. And a pattern that is larger than the pitch interval P1 of the holes arranged in the fifth row. The diameter of the hole, the number of holes, the pitch interval P1, and the pitch interval P2 are as shown in Table I below.

[Production of diamond electrode (6)]
A diamond electrode (6) was produced in the same manner as in the production of the diamond electrode (1) except that the hole pattern was changed to the pattern shown in FIG. 5 (f) instead of FIG. 5 (a). That is, in the arrangement pattern shown in FIG. 5F, the pitch intervals P2 of the holes arranged in the second and fourth rows in the vertical direction of the electrode substrate are arranged in the first, third, and fifth rows. The pattern is larger than the pitch interval P1 of the holes. The diameter of the hole, the number of holes, the pitch interval P1, and the pitch interval P2 are as shown in Table I below.

(2) Example 2
[Production of diamond electrode (7)]
In the production of the diamond electrode (1), an electrode substrate having a size of 40 mm × 40 mm was used, and the diameter of the hole, the number of holes, and the pitch interval P1 were as shown in Table I below. Produced a diamond electrode (7) in the same manner. That is, the holes were formed at equal intervals with a pitch interval P1 along the vertical and horizontal directions of the electrode substrate.

[Production of diamond electrode (8)]
In the production of the diamond electrode (5), an electrode substrate having a size of 40 mm × 40 mm is used, and the diameter of the hole, the number of the holes, the pitch interval P1, and the pitch interval P2 are shown in Table I below. A diamond electrode (8) was produced in the same manner as described above. That is, only one central row in the vertical direction of the electrode substrate was formed with a pitch interval P2, and the other rows were formed with a pitch interval P1.

[Evaluation method]
The following evaluations were performed and the results are shown in Table I below.
<Warpage amount>
About the diamond electrode manufactured as mentioned above, the curvature amount from the electrode substrate before vapor-depositing diamond was measured. The amount of warpage was measured at a location where the amount of warpage was the largest. A warp amount of 3 mm or less is regarded as practically no problem.

<Ozone concentration>
The diamond electrode produced as described above was used as an anode and a cathode, and was pressed against both surfaces of a cation exchange membrane (naphth ion membrane) to produce an ozone water generator shown in FIG. Then, a potential of 2.0 to 2.8 V was applied to the anode electrode and the cathode electrode for 10 minutes, and simultaneously, raw water was supplied to the anode electrode and the cathode electrode to generate ozone water. As raw material water to be supplied, pure water having 23.1 ° C., conductivity of 0.685 μS / cm, and a flow rate of 1.070 L / min was used. Then, the maximum ozone concentration of the generated ozone water was measured using a known concentration sensor.

From the results shown in Table I above, when the diamond electrodes (1) are all formed at the same pitch interval P1, the generated ozone concentration is high and the ozone generation efficiency is good, but warpage occurs during vapor deposition. did. Further, when the number of rows formed at the pitch interval P1 is smaller than the number of rows formed at the pitch interval P2 as in the diamond electrode (2), the occurrence of warpage can be suppressed, but the ozone concentration is low. .
On the other hand, even when there is no row formed with the pitch interval P1 as in the diamond electrode (3) or when there is no row formed with the pitch interval P2 as in the diamond electrode (4), the ozone concentration is high. Low.
As in the diamond electrodes (5) and (6) of the present invention, the number of rows formed at the pitch interval P1 includes rows formed at the pitch interval P1 and rows formed at the pitch interval P2. When the number of rows formed with the pitch interval P2 is smaller, a high ozone concentration was obtained while suppressing the occurrence of warpage.
As can be seen from the evaluation results of the diamond electrodes (7) and (8), this tendency is the same when the size of the electrode substrate, the number of holes, and the diameter of the holes are changed.

Moreover, in Example 1 and Example 2, it carried out about the case where the electrode substrate has a square shape in plan view. However, the same arrangement pattern shown in FIGS. 5A to 5F also applies to a rectangular shape in plan view. As a result of the experiment, the number of columns formed at the pitch interval P2 is equal to the number of columns formed at the pitch interval P2 and the columns formed at the pitch interval P1. When the number is less than the number (in the case of the arrangement patterns of FIGS. 5E and 5F), a high ozone concentration was obtained while suppressing the occurrence of warping.
Further, in Examples 1 and 2 described above, the diamond electrode was used for generating ozone water. However, when the above-described electrolytic water other than ozone water is used, the diamond electrode of the present invention has a high concentration. Electrolyzed water was obtained.

2 Catalytic electrode 21 Cation exchange membrane 22 Anode electrode 23 Cathode electrode 100 Ozone water generator 200 Diamond electrode 201 Electrode substrate 202, 203 Hole P1 Pitch interval P2 Pitch interval

1. A diamond electrode formed by vapor-depositing boron-doped diamond on the surface of a rectangular plate electrode substrate,
In the electrode substrate, a plurality of holes penetrating both surfaces of the electrode substrate are formed in alignment along the vertical and horizontal directions of the electrode substrate,
The electrode substrate has a row in which holes adjacent to each other in the vertical direction or the horizontal direction of the electrode substrate are formed at a pitch interval P1, and
The holes adjacent to each other in the vertical direction or the horizontal direction of the electrode substrate have a row formed with a pitch interval P2 larger than the pitch interval P1,
The number of columns that are formed at a pitch interval P1 is, rather multi than the number of rows formed by the pitch distance P2,
The pitch interval P1 is in the range of 0.1 to 10 mm, the pitch interval P2 is in the range of 0.7 to 15 mm, and the diameter of the hole is in the range of 0.5 to 10.0 mm. The diamond electrode characterized by being.

3 . The diamond electrode according to claim 1 or 2 , wherein the hole portion has a trapezoidal shape in a side sectional view in the thickness direction of the electrode substrate.

4 . The method for producing a diamond electrode according to any one of items 1 to 3 ,
When forming a plurality of holes penetrating both surfaces of the electrode substrate in the electrode substrate in alignment along the vertical and horizontal directions of the electrode substrate,
A row in which holes adjacent to each other in the vertical direction or the horizontal direction of the electrode substrate are formed in the electrode substrate at a pitch interval P1,
A row in which holes adjacent to each other in the vertical direction or the horizontal direction of the electrode substrate are formed at a pitch interval P2 larger than the pitch interval P1, and
A method for manufacturing a diamond electrode, wherein the number of rows formed at the pitch interval P1 is larger than the number of rows formed at the pitch interval P2.

5 . An electrolyzed water generating apparatus comprising the diamond electrode according to any one of items 1 to 3 .

Claims (7)

A diamond electrode formed by vapor-depositing boron-doped diamond on the surface of a rectangular plate electrode substrate,
In the electrode substrate, a plurality of holes penetrating both surfaces of the electrode substrate are formed in alignment along the vertical and horizontal directions of the electrode substrate,
The electrode substrate has a row in which holes adjacent to each other in the vertical direction or the horizontal direction of the electrode substrate are formed at a pitch interval P1, and
The holes adjacent to each other in the vertical direction or the horizontal direction of the electrode substrate have a row formed with a pitch interval P2 larger than the pitch interval P1,
The diamond electrode, wherein the number of rows formed at the pitch interval P1 is larger than the number of rows formed at the pitch interval P2.   2. The diamond according to claim 1, wherein the row formed at the pitch interval P <b> 2 is located at a central portion within a range of 1 to 15% of a length in the vertical direction or the horizontal direction of the electrode substrate. electrode. The pitch interval P1 is within a range of 0.1 to 10 mm,
The diamond electrode according to claim 1 or 2, wherein the pitch interval P2 is in a range of 0.7 to 15 mm.   The diameter of the said hole part exists in the range of 0.5-10.0 mm, The diamond electrode as described in any one of Claim 1- Claim 3 characterized by the above-mentioned.   The diamond electrode according to any one of claims 1 to 4, wherein the hole portion has a trapezoidal shape in a side sectional view in the thickness direction of the electrode substrate. A method for producing a diamond electrode according to any one of claims 1 to 5,
When forming a plurality of holes penetrating both surfaces of the electrode substrate in the electrode substrate in alignment along the vertical and horizontal directions of the electrode substrate,
A row in which holes adjacent to each other in the vertical direction or the horizontal direction of the electrode substrate are formed in the electrode substrate at a pitch interval P1,
A row in which holes adjacent to each other in the vertical direction or the horizontal direction of the electrode substrate are formed at a pitch interval P2 larger than the pitch interval P1, and
A method for manufacturing a diamond electrode, wherein the number of rows formed at the pitch interval P1 is larger than the number of rows formed at the pitch interval P2.   An electrolyzed water generating apparatus comprising the diamond electrode according to any one of claims 1 to 5.

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