JPH07313980A - Electrode for ion water making apparatus, production thereof and ion water making apparatus - Google Patents

Abstract

PURPOSE:To extend the life of an electrode even when the electrode is used as an anode and a cathode by reversing polarity, to reduce the generation of chlorine by using the electrode as the anode, to prevent the mixing of chlorine into alkaline ion water and to obtain ion water fitted to drinking. CONSTITUTION:An electrode for an ion water making apparatus is obtained by providing a coating layer consisting of platinum metal containing 85-97mol% of platinum and 5-13mol% of tantalum in terms of metal on a conductive substrate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode for an ionized water generator, a method for producing the same, and an ionized water generator using this electrode as an electrode for electrolysis.

[0002]

2. Description of the Related Art Conventionally, metallic titanium has been used as a conductive substrate.
A metal electrode having a platinum group metal or its oxide coating layer formed thereon is used in various fields of the electrolytic industry.
However, the above-mentioned electrodes are rarely used for drinking water, especially for sterilizing tap water or for ionized water, except for some electrodes. Electrolysis of tap water has important purposes as follows. That is, river lake water, which is the source of tap water, contains metal ions such as silicon, sodium, potassium, aluminum, magnesium, and iron that are the main components of the crust. These metal ions have a content of a few ppm to a few tens of ppm, and are sources of mineral water suitable for living organisms.

On the other hand, tap water is different from the above-mentioned mineral water in that sterilization is insufficient by filtration alone, and it must be safe even if the water pipe is contaminated.
Sustainable chlorine is injected as a disinfectant. This amount is stipulated in the Enforcement Regulations of the Water Supply Act so that the residual chlorine amount at the end of the distribution pipe is 0.1 ppm or more for the free form and 0.4 ppm or more for the combined form. However, this chlorine having bactericidal activity not only impairs the taste of water but also produces chlorine compounds such as trihalomethane which may be a carcinogen, so it is desirable to remove chlorine as much as possible.

[0004] Therefore, as a conventional chlorine removal method, household water purifiers have been widely used for improving the quality of drinking water by removing free chlorine and decalcifying tap water before drinking. The water purifier has a structure in which an activated carbon filter bed or the like is attached to a tap water faucet, and is a method of keeping a wet state at all times.

As another removing method, drinking water is introduced into the electrolysis chamber, electrolyzed and sterilized, and then taken out, and then ice-making is performed.

As still another method, an electrolytic cell (electrolytic chamber) is defined by a microporous diaphragm, a platinum-plated titanium or ferrite anode and a stainless steel cathode are immersed in the electrolytic cell, An ionized water generator that applies a DC voltage has been proposed, and this device is in widespread use. This device forms direct current electrolysis between electrodes to collect metal ions such as sodium, potassium and calcium on the cathode side, while collecting anions such as chloride ion and bicarbonate ion on the anode side, in the electrolytic cell on the cathode side. Is an alkaline mineral water (ionized water) containing a lot of metal ions and anions, which are produced by electrolysis of water.

However, in the case of producing ionized water using the conventional ferrite electrode as the anode,
It is not limited to a plate or rod, and does not become thin. Also, because it is ceramic, it is susceptible to shock.

Further, an electrode obtained by plating or coating a titanium base material with a noble metal or a noble metal oxide is also used for this purpose. For example, an electrode coated with an oxide of ruthenium and titanium or an electrode coated with an oxide of ruthenium and tin is known as an anode for chlorine generation (Japanese Patent Publication Nos. 46-21884 and 4).
No. 8-3954, Japanese Patent Publication No. 50-11330). However, ruthenium-based oxide electrodes cannot be used because ruthenium oxide is a harmful substance for food hygiene. Further, electrodes having a high efficiency of generating hypochlorous acid such as palladium oxide (Japanese Patent Publication No. 55-35473, Japanese Patent Publication No. 55-8).
In Japanese Patent No. 595), hypochlorous acid leaks into treated water such as alkaline water and has a chlorine odor, which is not suitable as drinking water.

It has also been proposed to use a platinum-plated titanium electrode or a platinum-coated titanium electrode in an ionized water generator (JP-A-5-57283). This electrode is safe from the viewpoint of food hygiene, has a low hypochlorous acid generation efficiency at the anode, and is suitable because there is little leakage of hypochlorous acid in alkaline water. However, in this ionized water generator, calcium ions or magnesium ions adhere to the surface of the cathode as hydroxides during electrolysis, which hinders the performance of the device. Therefore, it is necessary to switch the anode and cathode to remove these scales, but under high voltage,
Since the anode and cathode are switched, these electrodes have a short electrode life. Further, in these electrodes, when used as an anode and also as an oxygen generating electrode, the electrode life is shortened.
This problem becomes more remarkable as the frequency of use increases.

Further, as an oxygen generating electrode, an iridium oxide system and an iridium oxide-tantalum oxide system (Japanese Patent Laid-Open No. 63-235493, Japanese Patent Laid-Open No. 2-61083, Japanese Patent Laid-Open No. 3-1938989, Japanese Patent Publication No. 60). -2
No. 1232, Japanese Patent Publication No. 60-2207, Japanese Patent Application Laid-Open No. 57-116786, Japanese Patent Application Laid-Open No. 60-184690.
No.) is known, but this one also does not have sufficient corrosion resistance at the time of polarity reversal under high voltage. Further, there is a problem that the cost becomes commercially high.

Further, as the electrode for disinfecting drinking water, 40 to 90 mol% of platinum and Ti are deposited on a titanium substrate.
O ₂ , Ta ₂ O ₅ , ZrO ₂ , Nb ₂ O ₅ and SnO
It has been proposed to use an electrode (JP-A-6-33280) having a coating containing at least one selected from ₂ and 60 to 10 mol%. In this proposal Ta ₂ O ₅
In the case of using the -Pt (Ta ₂ O ₅ 10~60 mol%), Ta is 18.2 to 75% in terms of metal. It is said that the life of the tap water is long when the polarity is reversed at regular intervals in disinfecting tap water. However, in tap water disinfection, no diaphragm is provided, and in order to disinfect tap water, it is necessary that the electrode generate a large amount of chlorine and have a high residual chlorine concentration. When collecting alkaline ionized water, it is necessary to provide a diaphragm and generate less chlorine on the anode side and less residual chlorine flowing into the cathode side. This is because alkaline water with a high residual chlorine content is not suitable for drinking due to its chlorine odor. Therefore, this electrode cannot be used in an ionized water generator.

[0012]

SUMMARY OF THE INVENTION A first object of the present invention is to obtain alkaline ionized water which produces less chlorine and has a long life and excellent durability even when the polarity reversal between electrodes is repeated. Providing an electrode for a generator. Still another object is to provide a manufacturing method capable of advantageously manufacturing this electrode, and an ionized water generator using this electrode.

[0013]

The present inventors have found that tantalum oxide is added in a specific ratio to platinum metal on a conductive substrate such as titanium, which has excellent durability, low chlorine generation. As a result, it was found that the adhesion strength is strong without increasing the electric resistance, and further deterioration of the substrate due to titanium oxidation can be suppressed when it is used as an anode after polarity reversal, and the present invention has been completed based on these findings.

That is, the above-mentioned objects are as follows (1)-
This is achieved by the configuration of (5). (1) A cathode and an anode are arranged in the electrolysis chamber via a diaphragm, and both electrodes are energized, alkaline ionized water is obtained on the cathode side, acidic water is obtained on the anode side, and the polarities of the cathode and the anode are reversed at any time. Used in an ionized water generator used as a metal, on a conductive substrate, platinum 85 to 97 mol% and tantalum 3 on a metal basis.
An electrode for an ionized water generator provided with a coating layer of platinum metal containing tantalum oxide containing 15 to 15 mol%. (2) The contents of platinum and tantalum are 87-
The electrode for an ionized water generator according to (1) above, which is 95 mol% and 5 to 13 mol%. (3) The electrode for an ionized water generator of (1) or (2) above, which is used as an anode and a cathode. (4) After coating a solution containing a platinum compound and a tantalum compound on a conductive substrate, heat treatment is performed in an oxidizing atmosphere to obtain 85 to 97 mol% of platinum and 3 to 15 mol% of tantalum in terms of metal. A method for producing an electrode for an ionized water generator, which comprises forming a coating layer of platinum metal and tantalum oxide contained therein. (5) 2 inside the electrolysis chamber having the purified water inlet through the diaphragm
One or more electrodes are arranged to define compartments, each compartment is provided with an outlet, and operation is performed by energizing between the electrodes to obtain alkaline ionized water or acidic water from the outlet, and not operating. An ionized water generator for reversing the polarity of the electrodes between the electrodes and energizing the electrodes at least, wherein at least the electrode used as an anode during the operation uses the electrode according to any one of (1) to (3) above. Generator.

[0015]

Specific Structure The specific structure of the present invention will be described in detail below. Examples of the conductive substrate used in the electrode of the present invention include valve metals such as titanium, tantalum, zirconium, and niobium, or alloys of two or more metals selected from these valve metals.

In the electrode of the present invention, a coating layer made of platinum metal and tantalum oxide is provided on these conductive substrates. The ratio of platinum and tantalum in this layer is 85 mol% to 97 mol% of platinum, especially 8 mol% in terms of metal.
It is necessary that 7 to 95 mol% and tantalum be in the range of 3 to 15 mol%, especially 5 to 13 mol%. Good results are obtained only within this range.
If tantalum exceeds 15 mol%, residual chlorine will increase, and if tantalum exceeds 70 mol%,
This causes an increase in overvoltage and shortens the life. Moreover, the electrode life is shortened when the polarity is reversed. On the other hand, tantalum is 3 mol%
If it is less than the above range, the adhesion strength is not obtained, and the effect of suppressing the oxidation of the substrate is not sufficiently exerted. In addition, the electrode life due to polarity reversal becomes insufficient.

[0017] To fully achieve the intended effect, 0.01 mg / cm ² platinum in terms of metal in the coating layer to 5 mg / cm ²
It is preferable to apply it in such a ratio. 0.01 mg / cm ²
If it is less than 5%, the effect of the present invention cannot be obtained, and if it exceeds 5 mg / cm ² , the adhesion strength is lowered. Thus, in the present invention, the coating layer is made of platinum metal and tantalum oxide.

Next, a method for manufacturing the water electrolysis electrode will be described. In the case of a coating layer of platinum metal and tantalum oxide, after applying a solution containing a platinum compound and a tantalum compound on a conductive substrate, heat treatment is performed in an oxidizing atmosphere to obtain platinum of 97 mol% to 85 mol% and A coating layer made of tantalum oxide and platinum metal containing 3 to 15 mol% of tantalum is provided.

At this time, the coating solution used is a compound that becomes platinum metal by thermal decomposition, such as chloroplatinic acid (H ₂ Pt).
Cl ₆ .6H ₂ O), a platinum compound such as platinum chloride, and a compound that becomes tantalum oxide by thermal decomposition, for example, a tantalum halide such as tantalum chloride or a tantalum compound such as tantalum alkoxide such as ethoxy tantalum are prescribed. It can be prepared by dissolving in a suitable solvent in a ratio. The heat treatment in an oxidizing atmosphere is carried out by applying the coating solution on the conductive substrate, drying, and then firing in the presence of oxygen, preferably at a temperature in the range of 400 to 650 ° C. This operation is repeated a plurality of times until the required loading amount is obtained, and the electrode of the present invention is obtained.

The oxygen partial pressure in the oxidizing atmosphere is generally 0.05 atm or more. By thus performing the heat treatment for forming the coating layer in an oxidizing atmosphere, the tantalum oxide is sufficiently oxidized and the durability of the electrode is improved. On the other hand, when the heat treatment for forming the coating layer is not performed in an oxidizing atmosphere, the oxidation becomes insufficient,
Since the metal exists in a free state, the durability of the electrode is reduced.

The electrode of the present invention is arranged as an anode in an electrolytic cell or an electrolytic chamber of drinking water. At this time, the oxygen overvoltage is low and the life is long. Also, less chlorine is generated. At this time, it can also be used as a cathode. More specifically, the electrode of the present invention is used as a cathode and an anode of an ion water generator for performing electrolysis by appropriately reversing polarities between electrodes, when alkaline ionized water is generated on the cathode side to make drinking water. To be During the production of such alkaline ionized water, calcium or magnesium adheres to the cathode to lower the electrolysis efficiency. For this reason, the cathode and the anode are reversed to energize to remove these deposits (scales) and recover the electrolytic efficiency, that is, the water-forming efficiency. The electrode of the present invention has a long life even if polarity reversal is repeated, which is advantageous when such a usage method is adopted. Further, when the electrode of the present invention is used as an anode, chlorine (that is, hypochlorous acid) is hardly generated by electrolysis. Therefore, the alkaline ionized water obtained by electrolysis on the cathode side has no chlorine leakage and has a good flavor as drinking water.

FIG. 1 shows an example of the construction of an ionized water producing device (water making device) having an electrolytic cell for obtaining alkaline ionized water. As shown in FIG. 1, the water generator 1
Are calcium adding means 11 for adding calcium according to the water quality of the raw water W ₀ introduced from the water source 2, purifying means 12 for purifying the water after adding calcium, alkaline ionized water and acidic water by electrolyzing the purified water. It has an electrolysis means 13 which is an electrolysis tank for obtaining

The calcium adding means 11 is for adding calcium to make it easy to make alkaline as well as supplementing ions as minerals when well water or the like is used as raw water. Usually, calcium addition is not so necessary in tap water containing hypochlorous acid.
Calcium is added as calcium lactate or the like. The purifying means 12 is provided with antibacterial activated carbon and a hollow fiber membrane,
It purifies water by removing the odor of chlorine, red rust, and other bacteria.

The electrolysis means 13 has a cathode 31 and an anode 32 arranged in a tank 131 via a diaphragm M, and has a structure in which purified water is introduced through an inlet 131a to energize both electrodes 31, 32. Has become. Electrodes for electrolysis of the present invention are used for the cathode 31 and the anode 32.

In FIG. 1, a hot water prevention valve 14 for preventing hot water from flowing into the calcium adding means 11 is installed upstream of the calcium adding means 11. Further, a water drain valve 16 for draining water of the calcium adding means 11 is installed. Further, a flow rate sensor 17 is installed downstream of the purification means 12 and upstream of the electrolysis means 13, and controls so that the amount of water flowing into the electrolysis means 13 is an appropriate amount. A solenoid valve 19 is installed downstream of the outlet 131c of the electrolyzing means 13. Further, at the downstream of the other outlet 131b, a pH adjusting means 18 for setting the pH when alkaline ionized water is obtained via this flow path 18
Is provided. Further, the electrolysis means 13 is provided with a switching means 15 for reversing the polarities of the cathode 31 and the anode 32 in the electrolysis means 13. In addition, in the configuration of FIG.
Water W ₁ obtained via the adjusting means 18 is alkaline ionized water, and water W ₂ obtained via the solenoid valve 19 is acidic water.

In the structure of FIG. 1, the raw water W ₀ of the water source 2 is introduced into the calcium adding means 11 via the hot water prevention valve 14 (arrow f1 in the figure). However, when the water is hot water, the action of the hot water prevention valve 14 prevents the water from flowing into the calcium adding means 11 and flows in the direction of the arrow f2 in the figure. The water to which calcium has been added by the calcium adding means 11 is introduced into the purifying means 12. Here, the purified water obtained is introduced into the tank 131 of the electrolysis means 13 from the inlet 131a via the flow rate sensor 17. The purified water is electrolyzed here. By this electrolysis, alkaline ionized water W ₁ is obtained in the cathode chamber which is partitioned by the diaphragm M and in which the cathode 31 is arranged. In this case, the flow rate sensor 17 selects the optimum flow rate, and the pH adjusting means 18 sets the pH value of the alkaline ionized water W ₁ . The alkaline ionized water W ₁ thus obtained is taken out from the outlet 131b and used for drinking water or the like. On the other hand, acidic water W ₂ is obtained in the anode chamber in which the anode 32 is arranged. This is exit 13
It may be taken out from 1c through the solenoid valve 19 and used appropriately or may be discarded together with other unnecessary water in some cases. Since the generation of hypochlorous acid is suppressed in the acidic water W ₂ at this time, it is possible to prevent the chlorine content from flowing into the alkaline ionized water W ₁ and making it unsuitable for drinking water.

It should be noted that the diaphragm M is capable of moving ions, circulating a liquid, etc., has no problem in food hygiene, and can be separated by forming a flow path of alkaline ionized water and acidic water. There is no particular limitation and it can be used. Examples of such a material include polyethylene-based, polypropylene-based, nylon-based resin membranes, ion exchange membranes, and ceramic porous membranes.

The electrolysis conditions described above are such that a voltage of about 5 to 50 V is applied and the current density is about 0.1 to 10 A / dm ² . The electrodes 31 and 32 are plate-shaped in FIG. 1, but the distance between the electrodes at this time is 1 to 20 mm.
The electrolytic cell capacity is about 0.1 to 5 liters, and the flow rate of purified water to the electrolytic cell is about 0.5 to 20 liters / minute.

The alkaline ionized water thus obtained has a pH of about 7 to 10 and a chlorine content of about 0.01 to 1 ppm in terms of Cl ₂ . Further, the alkaline ionized water contains a mineral component such as Ca about 1.2 times or more that of the raw water. On the other hand, the pH of the acidic water is about 3 to 6 and the chlorine content is about 0.1 to 10 ppm in terms of Cl ₂ . Generally, alkaline ionized water is used as drinking water, and acidic water is used as lotion, cooking water, cleaning water, and the like. The raw water W ₀ in the above may be tap water, well water, or the like.

In the structure shown in FIG. 1, the purpose was mainly to take out alkaline ionized water. However, when the purpose is to take out acidic water, the switching means 15 reverses the polarities of the electrodes 31 and 32. , Outlet 13 of tank 131
The water taken out from 1b is made acidic. That is, electrolysis is performed using the electrode 31 as an anode and the electrode 32 as a cathode.

Further, in the electrode arrangement having the configuration shown in FIG. 1, when calcium or the like adheres to the cathode 31 and the electrolysis efficiency is lowered, the polarity of the electrode may be reversed and electricity may be applied. That is, the electrode 31 serves as an anode and the electrode 32 serves as a cathode. This restores the electrolysis efficiency.

The electrode of the present invention has a long life even when used in such polarity reversal. Further, it has a long life even when used under high voltage.

In FIG. 1, a plate-shaped electrode is used.
The shape of the electrode of the present invention is not particularly limited and may be rod-shaped, columnar,
It may be cylindrical or the like. For example, in FIG.
As shown in (a) and (b), both are cylindrical cathodes 33.
It is also preferable that the anode 34 and the cathode 34 are arranged coaxially with the anode 34 inside and the cathode 33 outside, and the cylindrical diaphragm M1 is arranged between them.

The purified water is supplied from the inlet 131a to the tank 131.
The alkaline ionized water is taken out through the outlet 131b and the acidic water is taken out through the outlet 131c.

The electrode arrangement in the electrolysis means 13 may be that shown in FIGS. 3 (a) and 3 (b). Figure 3
2A and 2B, a cylindrical cathode 35 is additionally provided inside the anode 34 to separate the cathode 35 and the anode 34 from each other in FIGS. 2A and 2B. Diaphragm M2
Is arranged.

In FIG. 3, purified water is introduced from the inlet 131a, alkaline ionized water is taken out from the outlets 131d and 131e, and acidic water is taken out from the outlet 131f.

Although the electrode arrangement of the water generator has been described above with reference to the illustrated example, the arrangement is not limited to this and may be various.

[0038]

EXAMPLES The present invention will be described in more detail below by showing specific examples of the present invention.

Example 1 A predetermined chloroplatinic acid (H ₂ PtCl ₆ .6H ₂ O) and tantalum ethoxide (Ta (OC ₂ H ₅ ) ₅ ) were dissolved in butanol to change the platinum / tantalum composition ratio. A coating solution having a metal equivalent concentration of 80 g / l was prepared.

Separately, the coating solution was applied onto a titanium substrate etched with hot oxalic acid with a brush, dried, and then placed in an electric furnace and baked at 550 ° C. while blowing air. The operations of coating, drying and baking were repeated an appropriate number of times until a predetermined loading amount was reached to prepare an electrode sample of a coating layer of platinum metal and tantalum oxide. Sample these
No. 1 to No. 7

About these electrodes, 60 ° C., 1 mol / l
A life test was performed in a sulfuric acid aqueous solution. Platinum was used for the cathode, the current density was 30 A / dm ² , and the samples No. 1 to No.
Electrolysis was performed using the electrode of No. 7 as an anode. The results are shown in Table 1.

Further, this electrode was prepared at 30 ° C. in standard synthetic water [sodium hydrogen carbonate (NaHCO ₃ ) 21 ppm,
Calcium chloride (CaCl ₂ ) 28 ppm, magnesium sulfate (MgSO ₄ ) 30 ppm, potassium hydrogen carbonate (KH
CO ₃ ) 2.5 ppm] and a life test with polarity reversal was performed. The same type of electrode is used for both the anode and cathode, and the current density is 5 A / dm
^{At 2} , electrolysis was performed by reversing the polarity every 15 minutes. The results are shown in Table 1.

Furthermore, regarding these electrodes, 30
After 30 minutes of electrolysis with standard synthetic water at ℃, the generation efficiency of chlorine was measured. That is, take 150 ml of standard synthetic water in a glass beaker, use a platinum electrode as the cathode, and make the electrode area 20 cm.
As ^2, after 12coul energized at 2A / dm ² at 20 ° C., it was measured of the generated amount of chlorine. For this measurement, residual chlorine was measured by the orthotolidine method, and then current efficiency (%) was calculated from the amount of electricity and the amount of chlorine generated. The results are shown in Table 1.

[0044]

[Table 1]

The electrode life indicates the time during which electrolysis can be performed, and the current efficiency of chlorine generation is based on the following criteria in the table.

Life: 1 mol / l aqueous sulfuric acid solution ◯: 2000 hours or more Δ: more than 1000 hours to less than 2000 hours ×: less than 1000 hours Life with polarity reversal ◯: 1500 hours or more Δ: more than 500 hours to less than 1500 hours × : Less than 500 hours Current efficiency of chlorine generation ○: Less than 5% △: 5% or more and less than 6% ×: 6% or more

As is clear from these results, the electrode of the present invention has a longer life at the time of polarity reversal than the comparative electrode,
The current efficiency of chlorine generation is low. When the current efficiency of chlorine generation was 6% or more, the smell of chlorine was so strong that it was difficult to drink.

Example 2 Sample No. 2 of Example 1 was used as a cathode and an anode in the water vaporizer shown in FIG. The structure of the electrolysis cell (electrolysis means) was as shown in FIG. The size of the cathode is 60mm,
Height 90mm, thickness 0.5mm, anode height is 40mm
mm, height 70 mm, and thickness 0.5 mm. The distance between the cathode and the anode was 3 mm, and a polypropylene diaphragm was provided in close contact with the anode to partition the cathode and the anode. The tank volume is 0.5 liter. The capacity of the anode chamber is 0.13 liter.

The above-mentioned water conditioner was subjected to electrolysis conditions of a flow rate of 3.5 liters / minute, a voltage of 30 V and a current density of 2 A / dm ² , and the total operation time per day for obtaining alkaline ionized water was 1
I used it for 6 months. In this case, the operation was performed for 15 minutes each, and after operating for 15 minutes, the polarity of the electrode was reversed for 3 to 4 minutes to recover the performance of the cathode. That is, the operation was performed for a total of 1 hour per day, the polarity of the electrode was reversed, and the operation was performed for a total of 0.25 hours.

During such 6 months of operation, the pH
Alkaline ionized water having a concentration of 9.9, a chlorine concentration (Cl ₂ conversion) of 0.1 ppm, and a calcium concentration (Ca conversion of 20 ppm) was stably obtained. There were almost no changes in pH, chlorine concentration and calcium concentration during this period.

During the operation for 6 months, the polarity of the electrode was reversed and used for the purpose of recovering the performance of the cathode.
In this case, acidic water having a pH of 5.7 was stably obtained.

When the same operation as above was carried out in the above-mentioned water producer except that the cathode and the anode were sample No. 5 of Example 1, electrolysis became impossible at the stage of use for 6 months.
It was also confirmed that the electrode performance gradually deteriorates during this period of use.

[0053]

INDUSTRIAL APPLICABILITY The electrode of the present invention exhibits sufficient durability even under electrolysis by polarity reversal and under high voltage, especially in anodic reaction after polarity reversal, and can be used for a long period of time. And the residual chlorine content is sufficiently low. Thus, the electrode of the present invention is suitable as an electrode for an ionized water generator.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an ionized water generator (water generator) of the present invention.

2A and 2B show an electrolytic cell according to the present invention, in which FIG. 2A is a vertical sectional view and FIG. 2B is a sectional view taken along line AA of FIG.

3A and 3B show an electrolytic cell according to the present invention, in which FIG. 3A is a vertical sectional view, and FIG. 3B is a sectional view taken along line BB of FIG.

[Explanation of symbols]

 1 water condenser 31-35 electrode M, M1-M2 diaphragm

Claims (5)

[Claims] 1. A cathode and an anode are provided through a diaphragm in an electrolysis chamber, and both electrodes are energized to obtain alkaline ionized water on the cathode side and acidic water on the anode side. Used in an ion water generator used in reverse, a coating layer of platinum metal and tantalum oxide containing 85 to 97 mol% of platinum and 3 to 15 mol% of tantalum in terms of metal is provided on a conductive substrate. Electrodes for ionized water generators. 2. The electrode for a deionized water generator according to claim 1, wherein the contents of platinum and tantalum are 87 to 95 mol% and 5 to 13 mol%, respectively. 3. The electrode for an ionized water generator according to claim 1, which is used as an anode and a cathode. 4. A conductive substrate is coated with a solution containing a platinum compound and a tantalum compound, and then heat-treated in an oxidizing atmosphere to obtain 85 to 97 mol% of platinum and 3 to 15 mol of tantalum in terms of metal. % Of platinum metal containing tantalum oxide and a method for producing an electrode for an ionized water generator, which comprises forming a coating layer of tantalum oxide. 5. An electrolysis chamber having a purified water inlet is provided with two or more electrodes via a diaphragm to define the compartments, each compartment is provided with an outlet, and electricity is applied between the electrodes. An ionized water generator that performs an operation to obtain alkaline ionized water or acidic water from the outlet and reverses the polarity of the electrodes between the electrodes when not in operation to supply electricity, and is used as an anode at least during the operation. An ionized water generator using the electrode according to any one of claims 1 to 3 as an electrode.