JPH10277551A - Electrolyte water generating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly electrolyze water without using harmful heavy metals by forming a partition wall separating a cathode room with a negative electrode from an anode room with a positive electrode from an ion-exchange membrane and forming the positive electrode of the anode room so as to have a surface area of conductive ferrite. SOLUTION: Ion-exchange water being electrolyte liquid 10 produced at a pure water producing device 14 is injected into an anode room 4 by opening an open/closure valve 16. Next, if a DC voltage is applied between an anode 1 of positive potential and a cathode 5 of negative potential, water molecules in the liquid 10 is oxidized so that oxygen gas and ozone gas is generated from the surface of the anode 1, which gas is dissolved into the liquid 10 to produce electrolytic bactericide water. And on the surface of the cathode 5 of a cathode room 6, oxygen in the outside air from an intake and exhaust mechanism 17, flowing electrons of negative potential of a DC power source 9, and hydrogen ions which are passed through a hydrogen ion conduction type ion exchange membrane 7 are present so that water is produced, which water is discharged from an exhaust port 22 in the form of vapor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive electrode suitable for producing ozone by electrolysis of an aqueous solution for the purpose of cleaning and sterilizing fresh vegetables, sterilizing and cleaning various contaminants, and surface treatment of industrial materials. The present invention relates to an electrolyzed water generation device provided with:

[0002]

2. Description of the Related Art There are two methods of generating ozone: a method of oxidizing oxygen in the air to ozone by electric discharge or ultraviolet rays, a method of electrically decomposing water into hydrogen and oxygen, and generating ozone as a by-product. There is. In the method of generating ozone from oxygen in the air, about 80% of nitrogen in the air undergoes an oxidation reaction at the same time, so that nitrogen oxides such as nitrogen dioxide and nitrogen monoxide are easily generated, and the processing gas is blown into water. When dissolved to produce ozone water, nitrogen oxides become nitric acid and become strongly acidic ozone water.

[0003] Also, due to the 80% nitrogen gas contained in the air, the partial pressure of ozone gas in the processing gas is extremely low, the amount of dissolution is small, and the concentration of ozone water that can be produced is limited. Therefore, in order to dissolve ozone in water at a high concentration and to produce neutral, pure and clean ozone water, a method using water electrolysis is recommended.

Usually, in order to generate ozone by this electrolysis, an electrolytic cell containing water is partitioned into an anode chamber and a cathode chamber by an ion exchange membrane, and air-permeable porous membranes are formed on both sides of the ion exchange membrane. A zero-gap electrolytic cell in which the positive electrode and the negative electrode are pressed is used. The anode compartment has a positive electrode in contact with the electrolytic solution. The positive electrode is formed by electrodepositing lead dioxide on a porous metal titanium mesh substrate via a platinum plating layer.

[0005] The cathode chamber is provided with a negative electrode, which is formed by subjecting a porous titanium metal mesh substrate to platinum plating similarly to the positive electrode. The reason why the porous electrode is used is that hydrogen gas generated at the interface between the ion exchange membrane and the surface of the negative electrode due to electrolysis of water in the cathode chamber is successively passed through the back of the negative electrode and discharged, and is used in the anode chamber. Similarly, oxygen gas and ozone gas generated at the interface between the ion exchange membrane and the positive electrode are sequentially passed through the back surface of the positive electrode and discharged.

[0006] In addition, porous metal titanium is selected as the base material of the positive electrode and the negative electrode, and platinum or lead dioxide is formed on the surface of the electrode substrate because the surface of the ion exchange membrane of the positive electrode becomes strongly acidic. This is because, of course, the electrode film and the counter electrode substrate in contact with this must be made of an acid-resistant material.

Further, the reason why lead dioxide is selected as the surface treatment of the positive electrode is that when the purpose is to generate ozone, the efficiency of other electrode materials is extremely poor. Regarding the relationship between various surface treatment materials for positive electrode and ozone generation efficiency,
P. C. Foller and C.I. W. Tobias, J. et al. E
electrochem. Soc. Vol. 129, page 506 as a relationship between current density and ozone current efficiency, and a graph thereof is shown in FIG.

[0010] Judging from FIG. 5, metal oxides such as lead oxide and tin oxide generate ozone more efficiently than DSE using platinum or ruthenium, and in particular, current efficiency at which β-type lead dioxide generates ozone most. It is clear that the values are high.

However, the physical properties of these metal oxides are very high, and even if they are brought into close contact with metal titanium or platinum by electrodeposition, the adhesion is poor, and the mechanical strength at the time of assembling the electrolytic cell is high. It is easily peeled off by the power of oxygen generation during electrolysis and the flow of electrolyte.

As a method for solving the above problem, Japanese Patent Publication No.
As in JP-A-41553, a lead-like powder is mixed with a fluororesin, molded into a porous plate, and then heated and fired, or the heated and fired is stretched further thinly to form a sheet-like electrode. A substrate has been proposed in which a substrate is oxidized and then the surface is plated with β-type lead dioxide.

According to such a molding method, the electrode substrate has smoothness and flexibility by the binder of the fluororesin, and the electrode is transformed into lower-grade lead oxide by sintering by plating after heating and sintering. Β required surface material
The electrode can be returned to the surface of the lead dioxide of the mold, and a flexible electrode having high ozone generation efficiency can be obtained.

[0012]

However, as described in Japanese Patent Publication No. 3-41553, a powder of lead dioxide is mixed with a fluororesin to form a porous plate, which is then heated and fired. Alternatively, it is inferred from the examples of the gazette that the heated and fired product is further thinned and stretched to form a sheet-shaped electrode substrate, and after the electrode substrate is oxidized, the surface is plated with β-type lead dioxide. Then, there is a disadvantage that it is very complicated and requires a large number of man-hours.

That is, starting from kneading of a fluororesin and lead dioxide, forming a plate by a roll, heating at 300 ° C. for 1 hour, baking at 360 to 390 ° C. for 30 minutes, stretching, and heating at 60 ° C. for 3 hours. An oxidation treatment with an aqueous solution of potassium oxide and a lead dioxide plating treatment with an aqueous solution of lead nitrate are required, and the positive electrode is finally completed through the above steps.

The electrode substrate obtained by heating and sintering has a fluororesin used as a binder for the powder of lead dioxide interposed between the powder and the powder to form a resistor. It is difficult, and ohmic loss tends to occur when the electrolytic solution is finally electrolyzed.

Further, lead dioxide is specified as a harmful substance in the Water Pollution Control Law and the like as a lead compound. When ingested by the human body, it is deposited on bone tissue and causes limb sensory impairment, etc., as well as liver damage and spasm. , Causing dysuria.
That is, if there is a concern that lead ions are eluted, it should be avoided from being used for drinking or sterilizing water for washing food. Therefore, the electrolyte cannot be used as sterile water as it is,
It is necessary to separate the once generated ozone gas, bubbling the water to be treated again, and regenerating ozone water in which ozone is dissolved in water.

[0016] Tin oxide can also be used as a surface treatment material for an ozone generating electrode, but it is in the category of heavy metals and is not safe to use in food applications. Iron, nickel, manganese, titanium and the like are considered to be relatively safe, but their oxides have a fatal problem that they do not have the conductivity required for electrodes.

[0017]

According to the present invention, a cathode chamber having a negative electrode, an anode chamber having a positive electrode in contact with an electrolyte, and a partition partitioning the cathode chamber from the anode chamber are formed by an ion exchange membrane. In the electrolytic cell, the positive electrode of the anode chamber is a kind of oxide, is an electrolyzed water generator characterized by having a surface layer of conductive ferrite,
The partition walls are made of a fluororesin-based ion-exchange membrane, and the same resin as the fluororesin-based ion-exchange membrane is applied to the surface of the ozone generating positive electrode having a ferrite surface layer. It is an electrolyzed water generation device characterized by being closely attached.

The positive electrode may be provided on a corrosion-resistant metal substrate with a base layer containing platinum and / or palladium oxide, or a composite oxide made of titanium and / or tantalum oxide may be provided on the base layer. Has a ferrite surface layer. In addition, it has a surface layer in which ferrite is anodically deposited by electrolysis or electroless plating, and at that time, forms a surface layer by dispersion plating in a plating bath containing a metal oxide of inactive titanium oxide and tantalum oxide, This is an electrolyzed water generating apparatus in which an ozone generating electrode having a magnetic body surface layer is formed by magnetizing after ferrite surface treatment.

[0019]

DETAILED DESCRIPTION OF THE INVENTION According to the first aspect of the present invention, a cathode chamber having a negative electrode, an anode chamber having a positive electrode in contact with an electrolyte, and a partition partitioning the cathode chamber and the anode chamber are provided. An electrolytic cell composed of an ion exchange membrane, the positive electrode of the anode chamber is an electrolyzed water generator having a surface layer of ferrite, and ozone generation is achieved by using conductive ferrite without using β-type lead oxide. To provide a highly efficient electrolyzed water generation device.

According to a second aspect of the present invention, the partition for separating the cathode chamber and the anode chamber is made of a fluorine resin ion exchange membrane, and the ozone generating positive electrode having a ferrite surface layer is made of the same material as the fluorine resin ion exchange membrane. By applying a resin of the system, the coated surface is in close contact with the fluororesin-based ion-exchange membrane, by using a fluororesin-based ion-exchange membrane that efficiently transmits only hydrogen ions with high heat resistance,
Gas diffusion electrodes can be used in the cathode compartment, explosive hydrogen can be replaced with water, and safety can be improved.
Furthermore, by applying the same type of fluororesin as the ion-exchange membrane to the uneven ferrite surface, the contact surface between the positive electrode surface and the ion-exchange membrane can be greatly increased, reducing the contact resistance and further improving the ozone generation efficiency. To obtain a good positive electrode.

According to a third aspect of the present invention, there is provided a positive electrode having a base layer containing platinum and / or palladium oxide on a corrosion-resistant metal base and having a ferrite surface layer on the base layer. The ozone generating positive electrode is capable of improving the electrical conductivity of the interface by increasing the electrical properties and improving the smoothness of the electrolysis of water.

According to a fourth aspect of the present invention, a positive electrode having a ferrite surface layer is provided by providing an underlayer of platinum and / or palladium oxide and an oxide of titanium and / or tantalum on a corrosion-resistant metal substrate. Thus, an ozone generating positive electrode capable of improving the adhesion to the substrate, increasing the electric conduction resistance of the interface, and smoothly electrolyzing water.

According to a fifth aspect of the present invention, the ferrite is precipitated by electrolytic or electroless plating. The formation of the surface layer by the plating at a low temperature can avoid thermal distortion as compared with the sintering method. This makes it possible to form an electrode surface layer having a porous and complicated shape and to easily control the ferrite component.

According to a sixth aspect of the present invention, when the ferrite is precipitated by plating, the composite surface layer is formed by dispersion plating in a plating bath containing an inert titanium oxide or tantalum oxide metal oxide. This has the effect of reducing plating distortion, and has the effect of improving adhesion and greatly extending electrode life.

According to a seventh aspect of the present invention, a positive electrode having a magnetic body surface layer is formed by magnetizing after surface treatment with ferrite, and the ion exchange membrane is formed by adsorbing impurities such as iron during electrolysis. The present invention has the effect of removing the obstructive factors that lower the transmission efficiency of hydrogen ions and the like, has the effect of dramatically extending the life of the ion exchange membrane, and enables efficient generation of ozone.

An embodiment of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 shows a schematic diagram of an electrolyzed water generator 2 using an ozone generating positive electrode 1 according to a first embodiment of the present invention, and a cross-sectional view of an electrolyzer 3.

The electrolytic cell 3 is composed of an anode chamber 4 having an ozone generating positive electrode 1 and a cathode chamber 6 having a negative electrode 5. The anode chamber 4 and the cathode chamber 6 are formed by partition walls 8 formed by an ion exchange membrane 7. It is divided by.

The ion exchange membrane 7 is a membrane mainly composed of a fluororesin having sulfonic acid groups, and has been developed as a hydrogen ion conduction type ion exchange membrane 7 by utilizing the property that hydrogen ions of sulfonic acid groups can freely enter and exit. It is a thing.

The ion-exchange membrane 7 is a polymer having a property of transmitting only hydrogen ions, and does not easily conduct or transmit other ions. The ion exchange membrane 7 of the hydrogen ion conductive type membrane used in the present embodiment is N.N.
117 polymer film was used.

Reference numeral 9 denotes a DC power supply for applying a positive potential to the positive electrode 1 and a negative potential to the negative electrode 5. The DC power source 9 is provided for the oxidation potential measurement electrode 11 immersed in an electrolyte 10 which is ion-exchanged water in the anode chamber 4. The signal is measured by the oxidation potentiometer 12 to control operation and stop.

As the positive electrode 1, a porous corrosion-resistant titanium metal mesh was used as a base, and the uppermost surface layer was formed by forming ferrite by electroless plating.

The negative electrode 5 was made of a porous mesh having through holes, and a mixture of a carbon powder and a fluororesin powder carrying ultrafine platinum particles on the surface was press-molded to give a moderate water repellency. A porous gas diffusion electrode was used.

Both electrodes were attached in close contact with the hydrogen ion conductive membrane 7. Reference numeral 13 denotes an ion-exchanged water injection mechanism including a pure water producing apparatus 14 equipped with an ion-exchange resin and an opening / closing valve 16 automatically opened and closed by a float switch 15. Are sent sequentially to

Reference numeral 17 denotes a suction fan 20 for sucking outside air through a filter 19 attached to a suction port 18, and a balance duct 21 for uniformly introducing outside air to the surface of the negative electrode 5.
And an exhaust port 22 for sequentially feeding outside air containing oxygen into the cathode chamber 6.

Reference numeral 23 denotes the electrolytic solution 1 treated in the anode chamber 4.
This is a drainage mechanism for sequentially discharging 0s. 24 is the anode chamber 4
Is an exhaust port of oxygen gas or ozone gas generated by the electrolysis of the above, and excess ozone gas contained therein is decomposed into oxygen by a treatment tower 25 containing activated carbon as an ozone decomposition catalyst and released to the atmosphere.

Reference numeral 27 denotes a guide for causing the flow of the electrolytic solution 10 together with the stirring device 28 to prevent the electrolytic water 10 from staying.

FIG. 2 is an enlarged sectional view of a main part of a joined body in which the ozone generating positive electrode 1 and the negative electrode 5 are pressure-bonded.

The ion exchange membrane 7 is made of a tantalum oxide dispersant 2
9 and a porous metal titanium mesh corrosion-resistant metal substrate 31 having a surface layer 30 formed of ferrite, sandwiched between a positive electrode 1 having a core as a core material and a negative electrode 5 formed of a diffusion electrode.

Reference numerals 32 and 33 denote current collectors connected to a DC power supply, respectively, for averaging voltages and supplying current to the respective electrode portions. A carbon honeycomb-shaped current collector 34 supporting a platinum catalyst is pressed against the surface of the negative electrode 5 opposite to the hydrogen ion conduction type ion exchange membrane 7 in order to increase the diffusion efficiency.

Reference numeral 35 denotes a resin layer of the same type as the fluororesin-based ion exchange membrane 7 applied before the positive electrode 1 is brought into close contact with the ion exchange membrane 7.

Reference numeral 36 denotes an underlayer formed of a composite metal oxide provided for improving the adhesion between the corrosion-resistant metal base 31 and the surface layer 30 of ferrite.

Here, the surface treatment step of the positive electrode 1 used in the first embodiment of the present invention will be described. First, the porous corrosion-resistant metallic titanium mesh substrate 31 is degreased by ultrasonic cleaning with a 5% surfactant solution, rinsed with ion-exchanged water, and then immersed in boiling water of a 5% oxalic acid solution for 5 minutes. The oxidized layer on the surface was removed, and immediately before the base treatment, 1N sulfuric acid was used as an electrolytic solution and electrolytic reduction was performed on the cathode side at 4 A / dm ² .

Immediately after the pretreatment, the titanium chloride, the tantalum chloride and the chloroplatinic acid were immersed in a mixed solution of hydrochloric acid adjusted to a concentration of 0.1 M, and preliminarily dried at 40 ° C. for 15 minutes.
Bake at 520 ° C. This baking base treatment was repeated three times to provide a conductive composite metal oxide base layer 36 of about 1 μm.

Next, the surface to be treated of the underlayer 36 is treated at 4 A / dm ² for 3 hours.
After performing the electrolytic reduction treatment for 0 seconds, a ferrite plating treatment as the next step was performed. Hereinafter, two methods of ferrite plating will be described with reference to FIGS.

FIG. 3 shows an apparatus used in the first ferrite plating method. First, distilled water from which dissolved nitrogen has been removed by passing a nitrogen gas through the plating tank 37 in advance.
In order to continue the removal of oxygen in the bath 44, 30 mmol of FeCl ₂ .4 (H ₂ O) was injected from the iron chloride supply device 39 while passing nitrogen gas from the nitrogen cylinder 38.
The mixture is stirred and uniformly dissolved with a stirrer 40, and the pH is adjusted to 6 to 7 with 50 mmol of sodium hydroxide filled in a pH adjuster 41. Further, 30 mM of ammonium acetate is added as a pH buffer.

Next, as an oxidizing agent, 50 mmol of sodium nitrite was added to distilled water from which dissolved oxygen had been removed by passing a nitrogen gas in advance, and the oxidation-reduction potential of the redox potential meter was -0.05 with respect to the hydrogen standard potential. The ferrite plating process is started while controlling the voltage at 4 V to -0.5 V.

Since the pH changes to an acidic side as the oxidation proceeds, 50 mmol of sodium hydroxide is injected into the bath 44 from an automatic pH adjuster 41 while measuring the pH with a pH meter 43, and the pH is adjusted to 6-7. Automatically adjust to

By plating for 1 hour, a plating layer having a thickness of about 2 μm is grown. In order to improve corrosion resistance and remove distortion,
Tantalum oxide is formed in the ferrite plating layer by dispersing 2 g / L of tantalum oxide in the bath and plating. The bath temperature at this time is adjusted to 60 ° C. by the heater 45.

FIG. 4 shows a second ferrite plating apparatus. The plating operation is an anodic deposition method.
6, a counter electrode 48 made of pure iron on a positive electrode plate 47 and a corrosion-resistant metal substrate 31 made of a porous metal titanium mesh, and a porous ceramic plate spacer 4 having a thickness of about 2 mm.
9 is sandwiched, and attached and fixed with a screw 50 with a spring.
The substrate surface is heated to 60 to 70 ° C. by the heater 51,
The reaction solution containing 50 mmol of iron (II) oxide was pumped through a pump 52.
And the counter electrode 48 and the corrosion-resistant metal substrate 3 at a flow rate of about 1 L / min.
1 flows through the interposed spacer 49.

At this time, the potential of the base 31 was set to about 0.3 V with respect to the counter electrode, and the current value was 0.1 A / dm ² .
It grows into a plating layer having a thickness of about 2 μm in a processing time of about 20 minutes. The reaction solution 52 in the solution tank 51 contains 30 mmol of Fe
A solution prepared by dissolving Cl ₂ .4 (H ₂ O), dispersing 2 g / L of tantalum oxide, and adjusting the pH to 6 with 50 mmol of sodium hydroxide is used. Also, 30 mM ammonium acetate is added as a pH buffer.

The reaction in ferrite plating by the anodic deposition method will be briefly described. The reaction formula (Chemical Formula 1) is an equilibrium reaction formula between iron and iron ions on the surface of the negative electrode body. When the pH is 6 and the iron ions are 30 mmol, the equilibrium potential is -0.485 V from the Purvey diagram.

The equilibrium potential of the chemical formula (2) is also -0.303.
V. Therefore, when a potential of 0.182 V or higher is applied to the base of the positive electrode with respect to the counter electrode, ferrite is formed.

However, the equilibrium potential of the chemical formula (3) is -0.13.
It is 4 V, and when a potential of 0.351 V or more is applied, trivalent iron oxide is formed and a nonconductive plating layer is formed.

When the pH is 7, the equilibrium potential of (Chemical Formula 1) is -0.485 V, whereas the equilibrium potential of (Chemical Formula 2) is -0.540 V, and The equilibrium potential is-
0.193 V, and ferrite precipitates in a range of 0 V or more and 0.292 V or less. Therefore, the electrolysis conditions of this ferrite plating were set to pH 6 and potential to 0.3 V.

[0055]

Embedded image

[0056]

Embedded image

[0057]

Embedded image

[0058]

Embedded image

When iron (II) chloride and other metal ions (M), for example, ions of nickel, cobalt, zinc, magnesium and the like are added to the bath, various ferrites are formed by the reaction of (Chem. 4).

Hereinafter, the operation of the electrolyzed water generating apparatus 2 of the first embodiment described above and the chemical reaction in the electrolytic cell 3 will be described.

First, the pure water producing apparatus 14 is operated to produce ion-exchanged water. Next, ion exchange water serving as the electrolyte 10 is injected into the anode chamber 4 by opening the on-off valve 16.
The opening / closing valve 16 is open until the float switch 15 detects that the water is full, and is automatically closed when the anode chamber 4 becomes full of the electrolyte 10.

Next, the main power supply terminal 26 of the DC power supply 9 is connected to a commercial power supply to start the operation of electrolysis. The positive electrode 1 was set to a positive potential, the negative electrode 5 was set to a negative potential, and a DC voltage of 3 V was applied between the positive electrode 1 and the negative electrode 5.

The material of the surface of the positive electrode 1 is formed of ferrite having a high corrosion potential and containing reactive oxygen, and there is almost no dissolution of the electrode material. Is oxidized, and the reactions of (Chem. 5) to (Chem. 8) occur.

From the equilibrium potential of the reaction formula, (Chem. 5) and (Chem. 8)
Is mainly formed, oxygen gas and ozone gas are generated from the surface of the positive electrode 1.

Further, the oxygen gas and the ozone gas having a strong oxidizing power are dissolved in the electrolytic solution immediately after the generation, and electrolytic sterilizing water having a sterilizing power is generated. Here, if it is a plating surface such as platinum,
Oxygen overvoltage is low and ozone generation is small due to only the reaction of (Chem. 5), but the reaction of (Chem. 8) is aggressive because the oxygen of the ferrite containing the reactive oxygen is catalyzed in the reaction of (Chem. 5). Ozone is efficiently generated, and the ozone concentration in the generated gas is increased.

[0066]

Embedded image

[0067]

Embedded image

[0068]

Embedded image

[0069]

Embedded image

[0070]

Embedded image

Here, since there is almost no increase in counter ions of hydrogen ions, excess hydrogen ions move to the cathode chamber 6 through the hydrogen ion conductive type membrane 7. for that reason,
No increase in the hydrogen ion concentration was observed in the anode chamber 4,
The pH will remain neutral.

Further, the resin layer 35 of the same type as the fluororesin-based ion exchange membrane 7 coated on the entire surface of the ferrite surface layer 30 allows hydrogen ions not only from the contact surface with the ion exchange membrane 7 but also from the entire positive electrode 1 to be removed. As a result, the current density is reduced and averaged, so that hydrogen ions can be transmitted efficiently.

On the surface of the cathode 5 in the cathode chamber 6, oxygen contained in the outside air sent by the intake / exhaust mechanism 17 and
The three components of the electrons flowing as the negative potential of the DC power supply 9 and the hydrogen ions generated in the anode chamber and passing through the hydrogen ion conduction type ion exchange membrane 7 are interposed, and the reaction of the chemical formula 9 is performed. To generate water. The generated water is adsorbed on the hydrogen ion conduction type ion exchange membrane 7 or is vaporized and discharged from the exhaust port 22.

When hydrogen ions generated on the surface of the positive electrode 1 by electrolysis react with oxygen gas on the surface of the negative electrode 5 and are converted into moisture, unreacted hydrogen may remain without sufficiently reacting. There is. Assuming this case, a carbon honeycomb-shaped auxiliary current collector 34 supporting a platinum catalyst is pressed on the surface of the negative electrode 5 opposite to the hydrogen ion-conducting ion exchange membrane 7, so that the hydrogen treatment is more perfect. It is possible to do.

The cathode 5 is made of a porous mesh having through holes, and has a moderate water repellency by pressure molding a mixture of a carbon powder and a fluororesin powder carrying platinum ultrafine particles on the surface. The porous gas diffusion electrode is attached to the hydrogen ion conduction type ion exchange membrane 7 in close contact, so that oxygen contained in the outside air, electrons transported through the negative electrode 5, and hydrogen ion conduction type The hydrogen ions passing through the exchange membrane 7 can be smoothly reacted by the catalytic action of the ultrafine platinum particles.
When the hydrogen ion-conducting ion exchange membrane 7 is isolated from the hydrogen ion-conducting ion exchange membrane 7, the movement of hydrogen ions is hindered by the nonconductive gas layer. Since the negative electrode 5 blocks the transfer of oxygen to the cathode, the three components cannot react smoothly.

As described above, a porous mesh-like material having through holes such as a porous gas diffusion electrode is used as the negative electrode 5, and the negative electrode 5 is closely attached to the hydrogen ion conduction type ion exchange membrane 7. The generation of moisture by the oxygen fed by the exhaust mechanism 17, the hydrogen ions passing from the anode chamber 4 through the hydrogen ion conduction type ion exchange membrane 7, and the electrons carried through the cathode is performed from the surface of the negative electrode 5. Hydrogen gas can be eliminated, and the danger of fire and explosion due to hydrogen gas can be eliminated. Further, since the cathode chamber 6 does not require an electrolytic solution, purified water, ion-exchanged water, distilled water, pure water, etc., it is not necessary to control the treatment of the electrolytic water and control the concentration, thereby greatly simplifying the structure of the electrolytic cell. And equipment costs can be reduced.

Further, in the anode chamber 4, pure water electrolytic sterilizing water can be produced by utilizing the oxidizing power of oxygen radicals, ozone and hydrogen peroxide water generated by the reactions of (Chem. 5) to (Chem. 8). Because water is close to neutral, it has little effect on the human body,
There will be no pollution problem in drainage.

The oxidation potential measuring electrode 11 and the oxidation potential meter 1
When the result of measuring the oxidation-reduction potential in Step 2 became 1100 mV or more with respect to the silver / silver chloride electrode, the operation of the DC power supply 9 was stopped to stop the electrolysis. The fact that the oxidation-reduction potential at this time is 1100 mV with respect to the silver / silver chloride electrode indicates that the dissolved ozone concentration of the electrolytic solution 10 at this time is 1 ppm or more.

As described above, by using the hydrogen ion-conducting ion exchange membrane 7 as the partition wall 8 of the electrolytic cell 3, only the movement of hydrogen ions occurs, and the electrolytic water in the anode chamber 4 becomes strongly acidic water. Since the electrolyzed water in the cathode chamber 6 does not become strongly alkaline water, it is easy to handle, and it is possible to obtain neutral ozone electrolyzed water that does not require any wastewater or neutralization treatment.

In the first embodiment, the combination of applying the same type of resin as the fluororesin-based ion exchange membrane to the surface of the ferrite surface layer 30 of the positive electrode 1 allows the fluororesin-based ion exchange membrane 7 to be used. The area of contact with the surface of the positive electrode 1 can be increased, and the local increase in current density can be prevented.

Although platinum was used as the binding metal to increase the adhesion between the corrosion-resistant metal substrate 31 and the ferrite, palladium may be used, and these are the most common surface treatment agents and have no corrosive properties and can be applied to living organisms. And gold and platinum group metals such as ruthenium, rhodium, osmium and iridium may be used.

Further, in the embodiment of the first embodiment, the method of producing magnetite is shown as a kind of ferrite, but various ferrites can be formed only by containing other metal ions such as nickel, cobalt and zinc in the plating bath. These ferrite electrodes are also good as ozone generating electrodes, and are not limited to magnetite.

After the ferrite plating, the positive electrode is magnetized by applying a magnetic field of 2000 to 20,000 gauss so that a magnetic force is applied to the surface of the positive electrode. Iron and metal ions, which inhibit ion transmission and reduce the life of the ion exchange membrane, are captured on the surface of the positive electrode, thereby greatly extending the life of the ion exchange membrane.

In the first embodiment, an example was shown in which ozone water was taken out from a drain and directly used as sterilizing water. However, a mixing nozzle was installed and a mixed gas of oxygen gas and ozone gas generated from an outlet was used. There is also a method in which ozone water is produced by directly blowing and mixing into tap water. As described above, the base layer made of platinum and / or palladium oxide and the oxide of titanium and tantalum is provided on the corrosion-resistant metal substrate, and the ferrite layer containing the composite oxide is formed by electrolytic or electroless plating treatment containing tantalum oxide. If the electrolyzed water generating apparatus has an electrolytic tank closely adhered to the ion exchange membrane after applying the same type of fluororesin as the ion exchange membrane on the surface, the adhesion to the electrode substrate is improved, An ozone-generating positive electrode that maintains electrical conductivity and ozone generation efficiency can be obtained. In addition, by using a fluorine resin-based ion exchange membrane that has high heat resistance and efficiently transmits only hydrogen ions, it is possible to use a gas diffusion electrode in the cathode chamber, and it is generated by electrolysis of water, which is a danger of explosion. Hydrogen can be replaced with water, and safety can be improved. In addition, by applying the same type of fluororesin as the ion-exchange membrane on the surface of the uneven composite material, the contact surface between the positive electrode surface and the ion-exchange membrane can be greatly increased, and the contact resistance can be reduced. Obtain a generating positive electrode. In addition, the electrolysis of water can be performed smoothly by priming with gold or palladium, which has high electrical conductivity, and no harmful heavy metals such as lead are used. A water generation device is provided. In addition, iron, which is the main component of ferrite, is a metal that has as little effect on the human body as platinum and titanium, and can be used with confidence in sterilizing water for fresh foods. This not only has the effect of preventing oxidation and suppressing the oxidation of platinum and palladium used in the undercoating process, but also forms a positive electrode surface having good electrical conductivity and ozone generation efficiency.

[0085]

As described above, the apparatus for producing electrolyzed water according to the present invention comprises a cathode chamber having a negative electrode, an anode chamber having a positive electrode in contact with an electrolyte, and a partition partitioning the cathode chamber from the anode chamber. In an electrolytic cell composed of an ion exchange membrane, the positive electrode of the anode chamber is an electrolyzed water generator having a surface layer of ferrite. It is an ozone-generating positive electrode that has good adhesion to the corrosion-resistant metal substrate, does not easily peel off, and can smoothly electrolyze water. It does not use harmful heavy metals such as lead and sterilizes fresh food even in food hygiene. It is intended to provide electrolyzed water that is safe as water and can be used safely for food applications. Further, by applying magnetic force to the electrode surface, impurities affecting the ion exchange membrane can be adsorbed to the electrode surface as much as possible, and the life of the ion exchange membrane can be extended.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an electrolyzed water generator and an electrolyzer according to a first embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a main part of a junction between a positive electrode, an ion exchange membrane and a negative electrode according to the first embodiment of the present invention.

FIG. 3 is a schematic diagram of a ferrite plating apparatus according to the first embodiment of the present invention.

FIG. 4 is a schematic diagram of a ferrite plating apparatus according to the first embodiment of the present invention.

FIG. 5 is a graph showing the relationship between the current density of the positive electrode surface material and the ozone current efficiency.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Positive electrode 2 Electrolyzed water generator 3 Electrolyzer 4 Anode chamber 5 Negative electrode 6 Cathode chamber 7 Ion exchange membrane 8 Partition wall 10 Electrolyte 30 Surface layer 31 Substrate 36 Underlayer

Claims (7)

[Claims] A cathode chamber having a negative electrode, an anode chamber having a positive electrode in contact with an electrolytic solution, and an electrolytic cell in which a partition partitioning the cathode chamber and the anode chamber is formed of an ion exchange membrane. An electrolyzed water generator, wherein the positive electrode of the chamber has a ferrite surface layer. 2. A partition partitioning the cathode chamber and the anode chamber from a fluororesin ion exchange membrane, and a resin of the same type as the fluororesin ion exchange membrane is applied to an ozone generating positive electrode having a ferrite surface layer. An electrolyzed water generating apparatus characterized in that the application surface is brought into close contact with the fluororesin-based ion exchange membrane. 3. The electrolyzed water generating apparatus according to claim 1, wherein an underlayer containing platinum and / or palladium oxide is provided on the corrosion-resistant metal substrate, and a positive electrode having a ferrite surface layer on the underlayer is provided. . 4. A positive electrode having a ferrite surface layer provided on a corrosion-resistant metal substrate by providing an underlayer made of platinum and / or palladium oxide and titanium and / or tantalum oxide. 3. The electrolyzed water generator according to 2. 5. A positive electrode having a surface layer on which ferrite is deposited by electrolytic or electroless plating.
The electrolyzed water generator according to claim 4. 6. The composite surface layer according to claim 1, wherein when the ferrite is deposited by plating, the composite surface layer is formed by dispersive plating in a plating bath containing an inert titanium oxide or tantalum oxide metal oxide. Electrolyzed water generator. 7. The electrolyzed water generating apparatus according to claim 1, wherein the positive electrode having a magnetic material surface layer is formed by magnetizing after surface treatment with ferrite.