JP2021042457A - Electrolysis cell and ozone water generator including the same, and conductive diamond electrode and its manufacturing method - Google Patents

Abstract

To provide a method for efficiently manufacturing a conductive diamond electrode to be applied for an electrolysis cell capable of generating high-concentration ozone water.SOLUTION: A method for manufacturing a conductive diamond electrode according to an aspect of the present disclosure includes: a step (a) of preparing a plate-like base material having a plurality of combinations of a first comb-like part and a second comb-like part engaging with the first comb-like part; a step (b) of forming a conductive diamond layer on at least one surface of the base material; and a step (c) of, after the step (b), dividing the base material into the plurality of combinations and then dividing the combinations into the first comb-like part and the second comb-like part.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to an electrolytic cell, an ozone water generator including the electrolytic cell, a conductive diamond electrode, and a method for producing the same.

Ozone water is used for disinfection or sterilization due to its oxidizing action. Patent Document 1 discloses an electrolytic cell that electrolyzes raw material water to generate ozone water.

Japanese Patent No. 6258566

The present disclosure provides an electrolytic cell capable of generating high-concentration ozone water and an ozone water generator including the electrolytic cell. The present disclosure also provides a conductive diamond electrode applicable to the electrolytic cell and a method for efficiently producing the conductive diamond electrode.

One aspect of the present disclosure relates to a method for manufacturing a conductive diamond electrode. This manufacturing method includes the following steps.
(A) Step of preparing a plate-shaped base material having a plurality of combinations of a first comb-shaped portion and a second comb-shaped portion that fits into the first comb-shaped portion (b) At least one of the above-mentioned base materials. After the step (c) step (b) of forming the conductive diamond layer on the surface of the above, the base material is divided into a plurality of the above combinations, and the combination is divided into a first comb-shaped portion and a second comb-shaped portion. The process of separating into

As described above, in the step (b), a conductive diamond layer is formed, for example, by chemical vapor deposition on the base material prepared in the step (a). As a result, the conductive diamond electrode can be produced more efficiently than preparing a plurality of first comb-shaped portions and a plurality of second comb-shaped portions in advance and individually forming a conductive diamond layer on them. Can be manufactured.

The conductive diamond electrode according to one aspect of the present disclosure is manufactured by the above manufacturing method. That is, the conductive diamond electrode has a comb-shaped portion having an electrolytic portion made of a plurality of metal members extending apart from each other and extending in parallel, and a frame portion connecting one end of the plurality of metal members. A conductive diamond layer formed on at least one surface of the comb-shaped portion.

In the base material prepared in the step (a) of the above manufacturing method, when the width of the gap of the first comb-shaped portion is the same as the width of the gap of the second comb-shaped portion, from one of the above combinations, substantially Two conductive diamond electrodes having the same electrolytic part to each other are obtained (see FIGS. 4 (a) and 4 (b)).

On the other hand, in the base metal prepared in the step (a) of the above manufacturing method, when the width of the gap of the first comb-shaped portion is larger than the width of the gap of the second comb-shaped portion, the first comb-shaped portion is The second comb-shaped member has an electrolytic part composed of a plurality of relatively thick metal members, while the second comb-shaped member has an electrolytic part composed of a plurality of relatively thick metal members (FIGS. 6A and 6). See (b)). If the metal member of the first comb-shaped portion is too thin, the area that contributes to the electrolysis of water is insufficient. In order to prevent this, one conductive diamond electrode may be obtained by combining the two first comb-shaped portions obtained in the step (c) so as to fit each other. That is, in this case, the conductive diamond electrode according to one aspect of the present disclosure includes a first electrode made of the conductive diamond electrode and a second electrode made of the conductive diamond electrode, and is a first electrode. The comb-shaped portion of the second electrode and the comb-shaped portion of the second electrode may be configured to fit each other (see FIG. 7).

The electrolytic cell according to one aspect of the present disclosure is for electrolyzing raw material water to generate ozone water, and is arranged between the anode and the cathode made of the conductive diamond electrode and between the anode and the cathode. It is provided with an ion exchange membrane. According to this electrolytic cell, since the anode has a complicated shape (comb shape), it is possible to sufficiently secure a region (three-phase surface) in which both water and the ion exchange membrane are in contact with the anode. As a result, according to the electrolytic cell, high-concentration ozone water can be generated.

The ozone water generator according to one aspect of the present disclosure includes the electrolytic cell, a container for accommodating the electrolytic cell and raw material water, a pump for supplying raw material water to the electrolytic cell, and a power source for supplying electricity to the electrolytic cell. To be equipped. Ozone can be generated in the electrolytic cell by supplying electricity to the electrolytic cell and supplying raw water to the electrolytic cell by a pump. Ozone water is obtained by dissolving this ozone in the water (raw material water) in the container.

According to the present disclosure, an electrolytic cell capable of generating high-concentration ozone water and an ozone water generator including the electrolytic cell are provided. Further, the present disclosure provides a conductive diamond electrode applicable to the electrolytic cell and a method for efficiently producing the conductive diamond electrode.

FIG. 1 is a plan view schematically showing an example of a base material subjected to precut processing. FIG. 2 is an enlarged plan view showing the base material shown in FIG. FIG. 3 is a vertical cross-sectional view schematically showing a base material after the conductive diamond layer is formed. 4 (a) and 4 (b) are plan views schematically showing the first and second conductive diamond electrodes according to the first embodiment. FIG. 5 is a plan view schematically showing a combination of the first comb-shaped portion and the second comb-shaped portion according to the second embodiment. 6 (a) and 6 (b) are plan views schematically showing the first and second conductive diamond electrodes according to the second embodiment. FIG. 7 is a plan view schematically showing a conductive diamond electrode configured by combining two conductive diamond electrodes. FIG. 8 is an exploded perspective view schematically showing an embodiment of the electrolytic cell according to the present disclosure. FIG. 9 is a cross-sectional view schematically showing an embodiment of the electrolytic cell according to the present disclosure. FIG. 10 is a cross-sectional view schematically showing an embodiment of the ozone water generator according to the present disclosure.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the following description, the same reference numerals will be used for the same elements or elements having the same function, and duplicate description will be omitted.

<Conductive diamond electrode>
(First Embodiment)
The conductive diamond electrode according to the present embodiment will be described with reference to FIGS. 1 to 4. The method for manufacturing the conductive diamond electrode of the present embodiment is as follows.
(A) A step of preparing a plate-shaped base material 10A having a plurality of combinations 5A of a first comb-shaped portion 1A and a second comb-shaped portion 2A that fits into the first comb-shaped portion 1A.
(B) A step of forming the conductive diamond layer 12 on at least one surface of the base material 10A, and
(C) After the step (b), the base material 10A is divided into a plurality of combinations 5A, and the combination 5A is separated into a first comb-shaped portion 1A and a second comb-shaped portion 2A.
The width W1 of the gap of the first comb-shaped portion 1A is the same as the width W2 of the gap of the second comb-shaped portion 2A (see FIG. 4). Hereinafter, each step will be described.

[Step (a)]
The step (a) is a step of preparing the base material 10A. The base material 10A is made of, for example, a plate-shaped member having a thickness of about 0.8 to 1.5 mm. Examples of the material of the base material 10A include niobium, tantalum, titanium, zirconium and alloys thereof. The base material 10A is precut, and as shown in FIG. 2, a plurality of openings H1 and H2 and a plurality of cuts L1 are formed. The combination 5A is defined by the plurality of openings H1 and H2 and the plurality of cuts L1. The plurality of combinations 5 are connected to each other via the connecting portion C1 and have such strength that the base material 10A is not divided into the plurality of combinations 5 in the step (b). The combination 5A according to the present embodiment is an octagon, and four of the eight vertices are connected to each other combination 5A adjacent to each vertex via a connecting portion C1 (see FIG. 2).

Combination 5 is composed of a first comb-shaped portion 1A and a second comb-shaped portion 2A. In the combination 5A, the first comb-shaped portion 1A and the second comb-shaped portion 2A are formed so as to fit each other. The first comb-shaped portion 1A comprises an electrolytic portion 1c composed of a plurality of metal members 1b extending apart from each other and extending in parallel, and a frame portion 1d connecting one end of the plurality of metal members 1b. Has (see FIG. 4 (a)). The second comb-shaped portion 2A comprises an electrolytic portion 2c composed of a plurality of metal members 2b extending apart from each other and extending in parallel, and a frame portion 2d connecting one end of the plurality of metal members 2b. Has (see FIG. 4 (b)). The length of the metal member 1b is, for example, 3 to 20 mm, and may be 20 to 50 mm. The length of the metal member 2b is similar to this.

Although the first comb-shaped portion 1A and the second comb-shaped portion 2A are separated by the zigzag cut L2, they are connected at the connecting portion C2 (see the enlarged view in FIG. 2). As a result, in the step (b), the combination 5 has a strength that does not separate into the first comb-shaped portion 1A and the second comb-shaped portion 2A. The connecting portion C2 is formed between the tip of the metal member 1b of the first comb-shaped portion 1A and the frame portion 2d of the second comb-shaped portion 2A. In the present embodiment, as shown in the enlarged view in FIG. 2, the connecting portion C2 is composed of two openings H3 and is located between the two openings H3. By adopting the connecting portion C2 having such a configuration, there is an advantage that the first comb-shaped portion 1A and the second comb-shaped portion 2A can be easily separated in the step (c). The connecting portion C2 may be formed between the tip of the metal member 2b of the second comb-shaped portion 2A and the frame portion 1d of the first comb-shaped portion 1A.

The openings H1, H2, H3 and the cuts L1, L2 can be formed by, for example, a laser. Since the base material 10A is precut, in the step (c), the base material 10A after forming the conductive diamond layer 12 can be divided into a plurality of combinations 5A, and the combination 5A is used as the first comb. It can be separated into a shaped portion 1A and a second comb-shaped portion 2A.

[Step (b)]
The step (b) is a step of forming the conductive diamond layer 12 on the surface of the base material 10A. After surface-treating the base material 10A as necessary, for example, a conductive diamond layer 12 is formed on the surface of the base material 10A by chemical vapor deposition. The conductive diamond layer 12 contains diamond and an element doped thereto (for example, nitrogen or boron). FIG. 3 is a vertical cross-sectional view schematically showing the base material 10A after the conductive diamond layer 12 is formed. The thickness of the conductive diamond layer 12 is, for example, 3 to 10 μm.

[Step (c)]
The step (c) is a step of individualizing the base material 10A on which the conductive diamond layer 12 is formed into a plurality of conductive diamond electrodes. That is, the base material 10A is divided into a plurality of combinations 5A, and the combination 5A is separated into a first comb-shaped portion 1A and a second comb-shaped portion 2A. By cutting the connecting portion C1, the base material 10A is divided into a plurality of combinations 5A. By cutting the connecting portion C2, the combination 5A is separated into a first comb-shaped portion 1A and a second comb-shaped portion 2A. Since the conductive diamond layer 12 is sufficiently thin as described above, when the combination 5A is separated into the first comb-shaped portion 1A and the second comb-shaped portion 2A, the conductive diamond layer 12 is accompanied by this. 12 is also separated into the same shape as the first comb-shaped portion 1A and the second comb-shaped portion 2A.

Through the above steps, the first conductive diamond electrode 3A including the first comb-shaped portion 1A and the conductive diamond layer 12 formed on the surface thereof is obtained. Further, a second conductive diamond electrode 4A including the second comb-shaped portion 2A and the conductive diamond layer 12 formed on the surface thereof can be obtained. FIG. 4A is a plan view showing the first conductive diamond electrode 3A, and FIG. 4B is a plan view showing the second conductive diamond electrode 4A. The width W1 of the gap (same as the gap of the first comb-shaped portion 1A) of the first conductive diamond electrode 3A is, for example, 0.05 to 10 mm, and may be 0.2 to 0.5 mm. .. In the present embodiment, the width W2 of the gap (same as the gap of the second comb-shaped portion 2A) of the second conductive diamond electrode 4A is the same as the width W1. If the ratio of the width W1 to the width W2 (W1 / W2) is about 0.9 to 1.1, it can be said that the width W1 is the same as or substantially the same as the width W2.

(Second Embodiment)
In the first embodiment, the aspect in which the ratio (W1 / W2) of the width W1 and the width W2 of the gap is the same (including the case where they are substantially the same) is illustrated, but the width of the gap in the first comb-shaped portion is illustrated. May be greater than the width of the gap in the second comb. Hereinafter, the differences between the second embodiment and the first embodiment will be mainly described.

FIG. 5 is a plan view schematically showing a combination 5B of the first comb-shaped portion 1B and the second comb-shaped portion 2B according to the second embodiment. FIG. 6A is a plan view showing the first conductive diamond electrode 3B obtained from the first comb-shaped portion 1B, and FIG. 6B is a second view obtained from the second comb-shaped portion 2B. It is a top view which shows the conductive diamond electrode 4B of. From the viewpoint of strength, as shown in FIG. 5, the connecting portion C2 is formed between the tip of the metal member 2b of the second comb-shaped portion 2B and the frame portion 1d of the first comb-shaped portion 1B. There is.

The gap width W1 of the first conductive diamond electrode 3B is larger than the gap width W2 of the second conductive diamond electrode 4B. In the present embodiment, the width W1 is, for example, 0.07 to 10 mm and may be 0.25 to 0.5 mm. On the other hand, the width W2 is, for example, 0.05 to 9 mm and may be 0.2 to 0.45 mm. The ratio of the width W1 to the width W2 (W1 / W2) is, for example, 1.8 to 2.2, and may be 1.9 to 2.1 or about 2. If the precut process is performed in the step (a) so that the first conductive diamond electrode 3B having the shape shown in FIG. 6 (a) and the second conductive diamond electrode 4B shown in FIG. 6 (b) can be obtained. Good.

The second conductive diamond electrode 4B shown in FIG. 6B has a sufficiently narrow gap width W2, in other words, the electrode member 4c has a sufficiently wide width, and thus functions independently as an anode of an electrolytic cell. Can be done. The electrode member 4c is composed of a metal member 2b and a conductive diamond layer 12 formed on the surface thereof. The electrode member 3c, which will be described later, is composed of a metal member 1b and a conductive diamond layer 12 formed on the surface thereof. On the other hand, the first conductive diamond electrode 3B shown in FIG. 6A has a wide gap width W1, in other words, the electrode member 3c has a narrow width, so that it can function as an anode of an electrolytic cell. Two first conductive diamond electrodes 3B are used in combination. FIG. 7 is a plan view schematically showing a conductive diamond electrode 6 configured by combining two first conductive diamond electrodes 3B and 3B (first electrode and second electrode). It is presumed that the conductive diamond electrode 6 composed of the combination has substantially the same performance as the second conductive diamond electrode 4B.

<Electrolytic cell>
FIG. 8 is an exploded perspective view schematically showing an embodiment of the electrolytic cell. Here, an embodiment in which the first conductive diamond electrode 3A is used as the anode will be described as an example. The electrolytic cell 50 shown in FIG. 8 has a first conductive diamond electrode 3A as an anode (hereinafter, simply referred to as “anode 3A”), a cathode 20, and ions arranged between the anode 3A and the cathode 20. It is provided with an exchange membrane 30. The electrolytic cell 50 is a type called a separable type. That is, the ion exchange membrane 30 is airtight, and oxygen and ozone generated at the anode 3A and hydrogen generated at the cathode 20 are not mixed. Hereinafter, the specific configuration of the electrolytic cell will be described.

The case of the electrolytic cell 50 is composed of a holder 51 and a lid 52. As shown in FIG. 8, the holder 51 has a recess 51a for accommodating the anode 3A. On the other hand, the lid 52 is configured to accommodate the packing 53 inside. With these configurations, when the lid 52 is attached to the holder 51, a pressing force is applied to the laminate of the anode 3A, the ion exchange membrane 30 and the cathode 20 in the thickness direction in the case (FIG. 9). reference).

As shown in FIG. 9, a water intake port 51b for taking in the raw material water RW and a discharge port 51c for discharging the ozone water OW are formed in the lower part of the holder 51. An ozone water guide tube 74a is connected to the discharge port 51c. A through hole 52a is formed in the central portion of the lid 52. A through hole 53a is also formed in the central portion of the packing 53. These through holes 52a and 53a are for discharging hydrogen generated at the cathode 20. A hydrogen guide tube 74b may be connected to the through hole 52a of the lid 52. A plurality of grooves 53b are provided on the peripheral edge of the packing 53. The raw material water RW is supplied to the cathode 20 side through these grooves 53b.

The cathode 20 is made of a material that does not become embrittled with respect to the generated hydrogen. Examples of such a material include platinum group metals, nickel, stainless steel, titanium, zirconium, gold, silver, carbon, diamond and the like. The shape of the cathode 20 may be a plate shape, a plate shape having a plurality of holes, or a mesh shape. In particular, when the cathode 20 has a plate shape or a mesh shape having a plurality of holes, the contact area with the raw material water RW can be increased, and the efficiency of electrolysis is improved. The cathode 20 is connected to a power source via the electrode wire 20a. The anode 3A is connected to the power supply via the electrode wire 25a.

The ion exchange membrane 30 is a membrane having proton conductivity. Examples of the ion exchange membrane 30 include a fluororesin-based membrane and a hydrocarbon resin-based membrane. Of these, a fluororesin-based film is preferable from the viewpoint of resistance to ozone and peroxide. A preferred example of the fluororesin-based film is a Nafion (registered trademark) film. Nafion (registered trademark) is a copolymer of a fluororesin based on sulfonated tetrafluoroethylene, and is a polymer having ionic conductivity. The proton conductivity of Nafion is due to the incorporation of perfluorovinyl into sulfo group-modified tetrafluoroethylene, where anions and electrons do not move within the membrane, only ^{protons (H +) move within the membrane.} .. The thickness of the ion exchange membrane 30 is, for example, 0.1 to 1 mm.

According to the electrolytic cell 50, since the anode 3A has a complicated shape (comb shape), a region (three-phase surface) in which both the raw material water RW and the ion exchange membrane 30 are in contact with the anode 3A should be sufficiently secured. Can be done. As a result, according to the electrolytic cell 50, high-concentration ozone water can be generated.

<Ozone water generator>
An ozone water spray will be described as an example of the ozone water generator. The ozone water spray 100 shown in FIG. 10 includes an electrolytic cell 50, a container 60 containing the electrolytic cell 50 and raw water RW, a spray head 70, an ozone water guide tube 74a, a hydrogen guide tube 74b, and an electrolytic cell 50. A power source 80 for supplying electricity to the water supply and a control unit 90 are provided.

The container 60 includes a container body 61 for accommodating the raw material water RW, a mounting portion 62 for mounting the spray head 70 on the container body 61, and a jacket 65 for wrapping the container body 61 and the mounting portion 62. The container body 61 includes a water supply port 66 for injecting the raw material water RW and additives to be used as needed. Normally, the water supply port 66 is closed by the cap 66a. A power supply 80 and a control unit 90 are housed in the lower part of the jacket 65.

The spray head 70 includes a head main body 71, a trigger 72 provided on the front lower side of the head main body 71, and a nozzle 73 provided in the front center of the head main body 71. The trigger 72 serves as a pump that sucks the raw material water RW in the container body 61 and supplies it to the electrolytic cell 50. When the trigger 72 is operated, the power supply 80 is turned on by the control unit 90. As a result, ozone is generated in the electrolytic cell 50, and the ozone water OW reaches the nozzle 73 through the ozone water guide tube 74a and is ejected from the nozzle 73. _{The hydrogen H 2} generated in the electrolytic cell 50 is discharged to the outside of the ozone water spray 100 through the hydrogen guide tube 74b.

1A, 1B ... 1st comb-shaped part, 1b, 2b ... Metal member, 1c, 2c ... Electrolytic part, 1d, 2d ... Frame part, 2A, 2B ... Second comb-shaped part, 3A, 3B ... First Conductive diamond electrode, 4A, 4B ... Second conductive diamond electrode, 5A, 5B ... Combination, 3c, 4c ... Electrode member, 6 ... Conductive diamond electrode, 10A ... Base material, 12 ... Conductive diamond layer, 20 ... Electrode, 30 ... Ion exchange membrane, 50 ... Electrolytic cell, 51 ... Holder, 51a ... Recess, 51b ... Water intake, 51c ... Discharge port, 52 ... Lid, 52a ... Through hole, 53 ... Packing, 53a ... Through hole, 53b ... Groove, 60 ... Container, 70 ... Spray head (pump), 71 ... Head body, 72 ... Trigger, 73 ... Nozzle, 74a ... Ozone water guide tube, 74b ... Hydrogen guide tube, 80 ... Power supply, 90 ... Control unit , 100 ... ozone water spray (ozone water generator), C1, C2 ... connecting portion, H1, H2 ... opening, L1, L2 ... cut, H 2 _... hydrogen, OW ... ozone water, RW ... raw water, W1 ... first Width of the gap in the first comb-shaped part, W2 ... Width of the gap in the second comb-shaped part

Claims (8)

(A) A step of preparing a plate-shaped base material having a plurality of combinations of a first comb-shaped portion and a second comb-shaped portion that fits into the first comb-shaped portion.
(B) A step of forming a conductive diamond layer on at least one surface of the base material, and
(C) After the step (b), the base material is divided into a plurality of the combinations, and the combination is separated into the first comb-shaped portion and the second comb-shaped portion.
A method for manufacturing a conductive diamond electrode, including. The method for manufacturing a conductive diamond electrode according to claim 1, wherein the width of the gap of the first comb-shaped portion is the same as the width of the gap of the second comb-shaped portion. The method for manufacturing a conductive diamond electrode according to claim 1, wherein the width of the gap of the first comb-shaped portion is larger than the width of the gap of the second comb-shaped portion. The conductive diamond electrode according to claim 3, further comprising a step of obtaining one conductive diamond electrode by combining the two first comb-shaped portions obtained through the step (c) so as to fit each other. Production method. A comb-shaped portion having an electrolytic portion composed of a plurality of metal members separated from each other and extending in parallel, and a frame portion connecting one end of the plurality of metal members.
A conductive diamond layer formed on at least one surface of the comb-shaped portion,
Conductive diamond electrode. The first electrode made of the conductive diamond electrode according to claim 5 and
The second electrode made of the conductive diamond electrode according to claim 5 and the second electrode.
With
A conductive diamond electrode configured such that the comb-shaped portion of the first electrode and the comb-shaped portion of the second electrode are fitted to each other. An electrolytic cell for electrolyzing raw water to generate ozone water.
The anode made of the conductive diamond electrode according to claim 5 or 6,
With the cathode
An ion exchange membrane arranged between the anode and the cathode,
Electrolyzed cell. The electrolytic cell according to claim 7 and
A container for accommodating the electrolytic cell and raw water,
A pump that supplies the raw material water to the electrolytic cell,
A power supply that supplies electricity to the electrolytic cell and
Ozone water generator equipped with.

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