KR20130082118A - Sterilizing water generation apparatus - Google Patents

Abstract

PURPOSE: A sterilized water generating device is provided to reduce the size of a sterilized water generating device, improve the capability of the device, and extend the lifespan of an electrode for generating sterilized water. CONSTITUTION: A sterilized water generating device comprises an electrode and a control unit. The electrode is installed in an electrolytic bath through which water containing chloride ions passes. The control unit generates hypochlorous acid in the electrolytic bath by conducting the electrode. The electrode is prepared by installing a catalytic layer on an electrode substrate based on titanium or a titanium alloy. The catalytic layer is made of a complex of metal and/or metal oxide containing at least iridium oxide and tantalum oxide. The complex contains 35 or more mole% of titanium oxide based on a metal and contains 0.92-1.86 times of tantalum oxide based on the molar ratio to iridium oxide. The control unit conducts the electrode with electric current density of 7-20 A/dm^2. [Reference numerals] (AA) Duration time [hr]

Description

[0001] Sterilizing water generation apparatus [

The present invention relates to a sterilizing water generating device for producing electrolytic water having high sterilization performance by directly electrolyzing water containing chloride ions (Cl ⁻ ). Specifically, the present invention relates to chlorine (Cl 2) by directly electrolyzing water containing chloride ions. _It relates to a sterilizing water generating device for generating ₂ ) to generate hypochlorous acid water.

Water containing chloride ions is directly electrolyzed by an electrode to generate chlorine at the anode, and by using the sterilization property of hypochlorous acid generated by the reaction of this chlorine and water, It is known to sterilize hands, humidifying water, bath water, toilets, nozzles of hot water toilets, and the like. In such electrolysis, since tap water is mainly used, calcium in the tap water may adhere to the surface of the cathode as calcium carbonate (hereinafter referred to as scale) to block the narrow electrode or the cleaning nozzle. In order to prevent this, it is generally known to perform a 'pole change' which periodically switches the polarity of the cathode and anode to remove the scale attached to the cathode.

In addition, in order to obtain stable and high chlorine generation effect characteristics in dilute saline, it is common to use an electrode having an electrode catalyst layer formed of a composite of platinum, iridium oxide, rhodium oxide, and tantalum oxide on a conductive substrate (Japanese Patent Laid-Open 2009-052069).

However, in the electrode having the composition described in JP-A-2009-052069, the electrode life is remarkably lowered when the frequency of pole switching is increased in order to suppress the blocking of small diameter flow paths such as cleaning nozzles by the scale. The problem which needs to be solved in the point of high lifetime of the sterilizing water production | generation apparatus has arisen. Specifically, for such an electrode, increasing the frequency of polar switching for switching the polarity of the positive electrode and the negative electrode desorbs iridium oxide necessary for generating hypochlorous acid from the catalyst layer, thereby lowering the electrolytic performance and shortening the electrode life. As a countermeasure, it has generally been adopted to increase the surface area of the electrode. In this countermeasure, the amount of expensive metal catalysts increases, resulting in high cost, and the electrolytic cell is also enlarged, so that the storage in a limited space such as a hot water toilet is very large. There was a problem of difficulty.

The present invention has been made on the basis of the recognition of the above problems, and the sterilizing water generating apparatus capable of achieving a high level of miniaturization of the sterilizing water generating apparatus, improvement of the ability to generate sterilizing water, and high life of the electrode for generating the sterilizing water. Is to provide a line.

In order to achieve the above object, the present invention provides a chlorine to the positive electrode by directly electrolyzing water containing chloride ions, and in the sterilizing water generating apparatus for generating sterilized water of hypochlorous acid by the reaction of the chlorine and water, An electrode provided with a catalyst layer on an electrode body made of titanium or a titanium alloy provided in an electrolytic cell through which water containing ions passes, and control means for energizing the electrode to generate hypochlorous acid in the electrolytic cell; The catalyst layer of the electrode consists of a complex of metals and / or metal oxides comprising at least iridium oxide and tantalum oxide, the complex containing more than 35 mole percent tantalum oxide in terms of metal, and in a molar ratio relative to iridium oxide It contains 0.92 to 1.85 times tantalum oxide, the control means is a current mill with respect to the electrode It is comprised so that electricity may be supplied to FIG. 7A / dm <2> -20A / dm <2>.

Based on this configuration, the supporting capacity of iridium oxide to the catalyst layer is increased by increasing the amount of tantalum oxide than the electrode generally used in the past, and the life of the electrode is increased by preventing the iridium oxide from leaving the catalyst layer due to the polar change. It becomes possible.

On the other hand, since tantalum oxide itself is an insulating material, by simply increasing the tantalum oxide, in a general product in which the applied voltage is limited, the electrical resistance increases and the hypochlorous acid generating ability is lowered. In addition, as the tantalum oxide increases, the conductive portion in the catalyst layer decreases, so that charge concentration to iridium oxide which becomes a limited conductive portion occurs, thereby degrading iridium oxide. In addition, when charge concentration occurs, there is a concern that the valence of iridium oxide is reduced, the pressure breakdown due to the pressure rise due to the generation of excess hydrogen gas, and the excessive heat rise are also concerned. There was a risk of this being made. Therefore, it was found that not only the performance deterioration but also the deterioration of the electrode is promoted depending on the degree of increasing tantalum oxide.

In the present invention, the composite contains more than 35 mol% of tantalum oxide in terms of metal, and contains 0.92 to 1.85 times of tantalum oxide in molar ratio with respect to iridium oxide, and then the electrode by the control means. By setting the current carrying amount of 7A / dm 2 to 20 A / dm 2, new problems such as securing the amount of hypochlorous acid produced and deterioration due to charge concentration to iridium oxide can be suppressed. In an electrode in which the amount of tantalum oxide is more than 35 mol% and is 0.92 to 1.85 times the molar ratio with respect to iridium oxide, when the current density is less than 7 A / dm 2, sufficient hypochlorous acid production concentration is achieved by increasing the electrical resistance. It is difficult to secure the surface area, and the amount exceeding 20 A / dm 2 becomes remarkable when the iridium oxide is promoted or deteriorated due to charge concentration. These peculiar constitutions can suppress catalyst deterioration due to iridium oxide detachment even when polarization is performed to suppress the generation of scale, and performance deterioration due to increased tantalum oxide and charge concentration to iridium oxide It is possible to provide a practically excellent sterilizing water generating device capable of suppressing deterioration acceleration due to.

Moreover, it is more preferable that the said composite further contains rhodium oxide. Rhodium oxide has the effect of reducing the overvoltage of the hydrogen formation reaction and promoting the formation reaction of hypochlorous acid. Therefore, by further containing rhodium oxide, the promotion and detachment of deterioration due to charge concentration to iridium oxide can be suppressed, and the life of the electrode can be extended.

The composite further contains platinum, and more than 4 mol% of platinum, 37-57 mol% of iridium oxide, 3-11 mol% of rhodium oxide, and 35 mol% of tantalum oxide, and 53 mol% or less of the complex. More preferred. It is a suitable formulation for obtaining durability under predetermined operating conditions.

Moreover, as for tantalum oxide of the said catalyst layer, it is more preferable that 42-48 mol% is mix | blended. While ensuring sufficient sterilization performance, it is possible to provide a practically excellent sterilizing water generator that can be made compact and have a good balance of long life.

Further, the control means is more preferably configured to energize the electrode at a current density of 12 A / dm 2 to 17 A / dm 2. While ensuring sufficient sterilization performance, it is possible to provide a practically excellent sterilizing water generating device which is more compact and has a long life optimum balance.

In addition, the water containing chloride ions supplied to the electrolytic cell is more preferably configured as an oil-flow formula that does not circulate water. By increasing the amount of tantalum oxide, as described above, charge concentration to iridium oxide due to the reduction of the conductive portion is likely to occur. When such charge concentration occurs, there is a strong acid atmosphere around the iridium oxide on the anode side. When the anode is converted from the anode to the cathode in a state of strong acid atmosphere, the valence of iridium oxide is reduced, and the bonding force to the catalyst layer is remarkably decreased. It is guessed that it will fall.

In the present invention, since the electrolyzer is flown, near-neutral water before electrolysis is supplied to the electrode, thereby suppressing the strong acid atmosphere around the iridium oxide on the electrode side, which becomes the cathode after the polarization, thereby reducing the bond strength of the iridium oxide. It can suppress and release of iridium oxide from a catalyst layer can be suppressed. This also reduces the influence of increasing the amount of tantalum oxide. In other words, when the electrolytic cell is made into a low water type in which water is stored, a strong acid atmosphere tends to be around the electrode on the cathode side, which leads to a decrease in life.

Further, it is more preferable that the control means is configured to perform a polarity switching for switching the polarity of the electrode to the anode and the cathode at intervals within 30 seconds with respect to the electrode. As a result, charge concentration occurs by increasing the amount of tantalum oxide, so that a strong acidic atmosphere around the iridium oxide on the cathode side after the polarization can be suppressed with a simple configuration. If the interval of pole switching is widened in the state of high current density, a strong acid atmosphere will be around the iridium oxide on the anode side. Therefore, the fall of the bonding force of iridium oxide in the reaction at the cathode side electrode after the pole switching is promoted for the above reason. In the present invention, even when the amount of tantalum oxide is increased, it is possible to suppress an acidic atmosphere by making the polar transition within 30 seconds, and to suppress the decrease in the bonding force of the iridium oxide after the polar transition.

In addition, the control means is more preferably configured to perform the polarity switching to switch the positive electrode and the negative electrode of the electrode at intervals of 4 to 15 seconds with respect to the electrode. As a result, the reduction in the bonding force of the iridium oxide after the polar change can be more surely suppressed, and a practically excellent sterilizing water generating device can be provided which is more compact and has a long life optimum balance while ensuring sufficient sterilizing performance.

According to the present invention, miniaturization of the sterilizing water generator, improvement of the ability to generate sterilizing water, and high life of the electrode for generating sterilizing water can be achieved at a high level.

1 is a schematic view for explaining an electrolyzer used in a sanitary washing apparatus having a sterilizing water producing device according to an embodiment of the present invention.
FIG. 2 is a graph showing the relationship between the drainage time after the pole switching in the electrolytic cell shown in FIG. 1 and the adhesion amount of calcium (scale) attached to the electrode plate.
3 is a perspective view showing a flush toilet with a sanitary washing apparatus according to an embodiment of the present invention.
4 is a flow diagram of the flow path of the sanitary washing apparatus shown in Fig.
FIG. 5 is a view for explaining the operation of each element during sterilization cleaning in the sanitary washing apparatus shown in FIG. 3, (A) is a graph showing the voltage applied between the electrode plates of the electrolytic cell, and (B) is a control unit. The graph which shows the measured electrolysis time of the electrolyzer, (C) is the graph which shows the quantity of water which flows through a discharge flow path, (D) is the graph which shows the quantity of water which flows through a discharge flow path.
6 is a cross-sectional view of the electrode plates 2 and 4 taken with an electron microscope.
7 is a graph showing the relationship between the molar ratio of tantalum oxide to iridium oxide and the amount of chlorine produced in the catalyst layer of the electrode plate.
Fig. 8 is a graph showing the relationship between the molar ratio of tantalum oxide to iridium oxide and the endurance time of the catalyst layer of the electrode plate.
Fig. 9 is a graph showing the relationship between the current density and the electrode lifespan applied between electrode plates.
FIG. 10 is a schematic cross-sectional view of an electrode plate schematically showing a mechanism in which the electrode plate deteriorates when the pole is switched in the comparative example. FIG.
Fig. 11 is a schematic cross-sectional view of the electrode plate, which schematically shows a mechanism in which the electrode plate deteriorates when the pole is switched in the present invention.
12 is a principle explanatory diagram showing changes in pH in the vicinity of the electrode plate when the intervals between pole switching are different.

Hereinafter, a sanitary washing apparatus having a sterilizing water producing apparatus according to an embodiment of the present invention will be described with reference to the drawings.

First, with respect to the sanitary washing apparatus of the present embodiment, the problems found by the inventors of the present invention will be described.

1 is a schematic diagram for explaining an electrolyzer used in a sanitary washing apparatus having a sterilizing water producing device according to an embodiment of the present invention. As shown in FIG. 1, the electrolytic cell 1 has a pair of electrode plates 2 and 4, and electrolyzes water by applying a voltage between these electrode plates 2 and 4. 1A shows a state in which a voltage is applied such that the electrode plate 2 becomes a cathode and the electrode plate 4 becomes an anode.

Since tap water contains chloride ions, chlorine is generated in the electrode 4 on the anode side by electrolyzing tap water. The chlorine generated in this way is dissolved in water and hypochlorous acid is generated. In this way, the electrolytic bath 1 can generate sterilized water containing hypochlorous acid.

At this time, in the electrode plate 2 on the cathode side, calcium ions contained in the tap water are attached to the electrode plate 2 as calcium carbonate (scale). When calcium carbonate adheres to the electrode plate 2 in this manner, the ability to generate sterilizing water is reduced.

Therefore, the electrolytic cell 1 of the sanitary washing apparatus of the present embodiment is, for example, at a predetermined timing such as the cumulative generation time of the sterilizing water reaching a predetermined time, in the state shown in FIG. So-called pole switching is performed inverting the voltage applied between the electrode plates 2, 4 in the state shown in 1B. By pole switching in the state shown in FIG. 1B, the electrode plate 2 functioning as the cathode becomes an anode, and the electrode plate 4 functioning as an anode becomes a cathode. For this reason, acid is produced | generated in the electrode plate 2 with calcium carbonate, and calcium carbonate dissolves by this acid, and the calcium carbonate adhering to the electrode plate 2 can be peeled off.

Next, since the present inventors examined the relationship between the drainage time after pole switching in the electrolytic cell 1, and the adhesion amount of calcium (scale) to an electrode, it demonstrates below. In this study, the relationship between the drainage time after the pole switching and the deposition amount of calcium (scale) in the state where the voltage applied between the electrodes was 10V and 5V was investigated.

FIG. 2 is a graph showing the relationship between the elapsed time after the pole switching in the electrolytic cell shown in FIG. 1 and the amount of scale attached to the electrode after the elapsed time. As shown in FIG. 2, after predetermined time passes, the amount of calcium peeled from an electrode decreases significantly after polar switching. From this fact, it can be seen that most of the scale attached to the electrode is peeled off immediately after the polar change.

As shown in FIG. 2, when the voltage applied to the electrode is 10 V, the amount of scale attached to the electrode after the pole switching is reduced by about half as compared with the case where the voltage applied to the electrode is 5 V. FIG. From this fact, it can be seen that the larger the voltage applied to the electrode, the larger the scale is peeled off in a short time after the pole switching.

Based on the above results, in the sanitary washing apparatus according to the embodiment of the present invention described below, when sterilizing by operating the electrolytic cell, the sterilizing water generated at a predetermined time after the pole switching is discharged upstream of the nozzle. I do it. Hereinafter, the sanitary washing apparatus of the present embodiment will be described in detail.

3 is a perspective view showing a flush toilet with a sanitary washing apparatus according to an embodiment of the present invention. As shown in FIG. 3, the sanitary washing apparatus 100 is provided and used on the toilet bowl 120 of the flush toilet 110. As shown in FIG. Then, by operating by the controller, the washing nozzle 14 enters the toilet bowl 120, and the human body can be washed by blowing the sewage water from the tip of the washing nozzle 14 toward the human body (hip, etc.). .

4 is a flow diagram of a sanitary washing apparatus according to an embodiment of the present invention. In addition, although illustration of the element which is not related to sterilization washing | cleaning is abbreviate | omitted in FIG. 4, the sanitary washing apparatus of this embodiment is equipped with the structure required in order to wash | clean a well-known human body location.

As shown in FIG. 4, the flow path system 10 of the sanitary washing apparatus at the time of sterilization washing | cleaning which concerns on this embodiment is the water supply source 12, such as a water pipe, and the washing nozzle 14, The flow path 16, 18), the electrolytic cell 1 described above is provided in this flow path 16. The branch part 20 is provided downstream of the electrolytic cell 1 of the flow path 16, and the discharge flow path 18 which extends from the branch part 20 to the cleaning nozzle 14 and the lower part from the branch part 20 are provided. It is branched to the discharge flow path 22 extending toward.

The discharge flow path 18 is comprised so that the cross-sectional area (that is, the minimum flow path cross-sectional area of the discharge flow path 18) in the water discharge port of the washing | cleaning nozzle 14 may become small compared with the cross-sectional area of the minimum flow path of the discharge flow path 22. As shown in FIG. As a result, the pressure loss of the discharge passage 22 is smaller than that of the discharge passage 18.

A pump 26 communicably connected to the control section 24 is provided downstream of the branching section 20 of the discharge flow passage 18. The pump 26 pressurizes the water flowing through the discharge passage 18 on the basis of the command of the control section 24.

On the downstream side of the pump 26 of the discharge passage 18, a washing valve 28 connected to the control unit 24 so as to be communicable is provided. The washing valve 28 is opened and closed based on the command of the control unit 24 to control the inflow of water into the discharge passage 18.

A washing nozzle 14 is connected downstream of the washing valve 28 of the discharge passage 18, and the sterilizing water supplied through the discharge passage 18 is discharged from the discharge port of the washing nozzle 14. As a result, the body of the cleaning nozzle 14 can be sterilized and cleaned.

On the downstream side of the branch part 20 of the discharge flow path 22, the discharge valve 30 connected to the control part 24 so that communication is possible is provided. The discharge valve 30 is opened and closed based on the command of the control unit 24 to control the inflow of water into the discharge flow path 22. The discharge mechanism 32 is constituted by these discharge passages 22 and the discharge valve 30. In addition, in this embodiment, although the flow path 16 is branched off and the discharge flow path 22 is provided, it is not limited to this, You may just provide an opening in the lower surface of the flow path 16. FIG. In addition, in this embodiment, although the discharge valve 30 is provided in the discharge flow path 22, the flow of the water which flows through the discharge flow path 22 is controlled, It is not limited to this, It discharges using a pump etc. The flow of water flowing through the flow passage 22 may be controlled.

When the control part 24 drives the electrolytic cell 1, the control part 24 measures the cumulative accumulation time T of the time which the electrolytic treatment of the electrolytic cell 1 was performed. In addition, the control unit 24 is set in advance a predetermined cumulative time set value T _PC for determining the timing for performing the polarity change, and the cumulative electrolytic time T is set to this cumulative time set value T _PC . When it reaches | attains, pole switching of the electrolytic cell 1 is performed. Therefore, by shortening the accumulation time set value T _PC , the amount of adhesion of the scale to the electrode plate can be reduced. From the standpoint of the deposition amount of the scale, the cumulative time set value T _PC may be about 60 seconds, for example, when the voltage applied between the electrode plates is 5V.

In addition, the control unit 24 is set in advance a predetermined discharge time setting value T _OP for closing the washing valve 28 immediately after the pole switching and simultaneously opening the discharge valve 30. As described with reference to FIG. 1, when the discharge time set value T _OP for opening the discharge valve 30 is large, when the voltage applied between the electrode plates 2 and 4 is large, the discharge valve 30 is shortly after the pole switching. Since the scale is peeled off, the scale may be shortened. If the voltage applied between the electrode plates 2 and 4 is small, the scale may be long.

Hereinafter, the operation of the sanitary washing apparatus during sterilization and cleaning will be described.

FIG. 5 is a view for explaining the operation of each element during sterilization cleaning in the sanitary washing apparatus shown in FIG. 3, and (A) is a graph showing the voltage applied between the electrode plates 2 and 4 of the electrolytic cell 1. , (B) is a graph showing the cumulative electrolysis time of the electrolytic cell 1 measured by the control unit 24, (C) is a graph indicating the amount of water flowing through the discharge flow path, (D) is a graph showing the amount of water flowing through the discharge flow path to be. In addition, the graph of FIGS. 5A-D is described so that a horizontal axis (time axis) may correspond.

If the cumulative electrolytic time measured by the control unit 24 does not reach the cumulative time set value T _PC , and there is an input to perform sterilization cleaning on an operation unit (not shown) of the sanitary washing apparatus by the user. (I.e., t1, t3 in FIG. 5) and the electrolytic cell 1, the control unit 24 opens the cleaning valve 28 and closes the discharge valve 30. FIG. As a result, as shown in FIG. 5C, the sterilizing water generated in the electrolytic cell 1 flows into the discharge flow path 18, and is discharged from the discharge port of the cleaning nozzle 14, thereby removing the cleaning nozzle 14. Sterilization can be cleaned. After the sterilization cleaning of the cleaning nozzle 14 is completed, the sterilization cleaning is terminated at t2 and t4. Between these t1-t2 and t3-t4, as shown to FIG. 5 (B), the cumulative electrolyte time T of the electrolytic cell 1 measured by the control part 24 increases.

Next, when the sterilization cleaning is performed as described above, when the cumulative electrolytic time T reaches the cumulative time set value T _PC (that is, t5 in FIG. 5A), The polarization of the electrolytic cell 1 is performed. In addition, the control unit 24 simultaneously closes the washing valve 28 between immediately after the pole switching (t = t5) and the discharge time set value T _OP , and simultaneously opens the discharge valve 30. At the same time, the control unit 24 stops the pressure pump 26 provided in the discharge passage 18.

By performing pole switching in the electrolytic cell 1, as shown in FIG. 5A, the voltage applied to the electrode plates 2, 4 is reversed. As a result, the scale attached to the electrode plate 2 on the side which was the negative electrode until then is peeled off. On the other hand, since the washing valve 28 is closed and the discharge valve 30 is open, the sterilizing electrolyzed water is discharged to the bowl ball through the discharge passage 22. As a result, the sterilizing water including the scale is discharged into the bowl of the toilet bowl and does not flow into the washing nozzle 14, so that the water jetting port of the washing nozzle 14 can be prevented from being blocked by the scale.

Then, when the discharge time set value T _OP has elapsed in the pole switching (that is, t = t6), the control unit 24 closes the discharge valve 30 and simultaneously opens the cleaning valve 28, and further, the pump ( 26). As a result, the sterilizing water is supplied to the cleaning nozzle 14 again, and the cleaning nozzle 14 can be sterilized and cleaned.

As described above, according to the present embodiment, since the sterilizing water is discharged to the toilet in the upstream of the cleaning nozzle 14 of the flow path 16 for a predetermined time immediately after the pole switching, it is separated from the electrode immediately after the pole switching. It is possible to suppress the flow of the sterilizing water including the large scale to the washing nozzle 14 and to prevent the scale from clogging in the water discharge port of the washing nozzle 14.

As a result, in the electrolytic cell 1, the polar change can be performed more frequently, and stable sterilizing water can be supplied in the long term. In addition, since the sterilizing water 1 having a cleaning action is discharged to the toilet, the washing water for cleaning the toilet can be saved, and the toilet itself can be sterilized.

Further, according to this embodiment, during the discharge flow path 18 are provided, and, immediately after the polarity switching discharge time set value (T _OP), the washing valve 28 on, because by closing the washing valve 28, Immediately after the polar change, the electrolytic water supplied from the electrolytic cell 1 can be prevented from flowing into the discharge passage 18.

In addition, according to the present embodiment, since the discharge passage 18 is configured to extend upward, the discharge passage 22 has a smaller pressure loss than the discharge passage 18, and at the same time, the discharge passage 18 Existing water flows back toward the branch portion 20, thereby discharging the scale introduced into the discharge passage 18.

Moreover, according to this embodiment, by providing the discharge flow path 22 so that it may extend downward from the branch part 20, the electrolytic water containing a scale may be accelerated | emitted to the discharge flow path 22 by gravity, and discharge will be carried out. The flow of the sterilizing water including a scale into the flow path 18 can be suppressed.

On the other hand, in the above embodiment, the discharge flow path 18 that leads to the cleaning nozzle 14 by the cleaning valve 28 is closed during the discharge time set value T _OP immediately after the pole change, but the discharge flow path 18 must be closed. ) Need not be closed. As described above, in the sanitary washing apparatus of the present embodiment, the discharge passage 22 is configured such that the minimum passage section is larger than the discharge passage 18, and the discharge passage 22 is larger than the discharge passage 18. This pressure loss is small. For this reason, even if the discharge flow path 18 is not closed, when the discharge valve 30 is opened, the sterilizing water flows into the discharge flow path 18 and the discharge flow path 22.

Furthermore, in the sanitary washing apparatus of the present embodiment, since the pressurizing pump 26 is provided in the discharge passage 18, the pressurized pump 26 is stopped for the discharge time set value T _OP immediately after the pole change. In comparison with the discharge passage 18, the pressure passage 22 has a smaller pressure loss. For this reason, when the discharge valve 30 is opened, a large amount of sterilization water flows into the discharge flow passage 22 as compared with the discharge flow passage 18, so that the sterilization water including the scale flowing into the discharge flow passage 18 can be reduced. .

In the above embodiment, the control unit 24 closes the washing valve 28 and opens the discharge valve 30 at the same time as the pole switching of the electrolytic cell 1, but the present invention is not limited thereto. The sterilizing water generated in the electrolytic cell 1 may be discharged by the discharge mechanism 32 within a predetermined time. That is, when the discharge mechanism 32 is provided away from the electrolytic cell 1, the cleaning valve 28 may be closed and the discharge valve 30 may be opened after a predetermined time has passed after the pole switching.

6 is a cross-sectional view of the electrode plates 2 and 4 taken with an electron microscope. Titanium or a titanium-based alloy may be mentioned as a material of the electrode base 41 of the electrode plates 2 and 4. As the titanium alloy, a conductive alloy having corrosion resistance mainly composed of titanium is used. For example, Ti-type alloy used as a normal electrode material which consists of a combination of Ti-Ta-Nb, Ti-Pd, Ti-Zr, Ti-Al, etc. is mentioned. These electrode materials can be processed into a predetermined shape such as a plate shape, a plate shape with holes, a rod shape, a mesh plate shape, and the like, and can be used as the electrode body 41.

As described above, it is preferable that the electrode body 41 be pretreated in advance, as is usually done. Suitable examples of such pretreatment include those described below. First, the surface of the electrode substrate (hereinafter also referred to as titanium substrate) made of titanium or a titanium-based alloy is degreased by washing with alcohol or the like and / or electrolysis in an alkaline solution, according to a conventional method. The hydrofluoric acid having a hydrogen fluoride concentration of 1 to 20% by weight or a mixed acid of hydrofluoric acid and other acids such as nitric acid and sulfuric acid can be used to remove the oxide film on the surface of the titanium gas 41 while Coarse cotton is performed. The acid treatment can be carried out for several minutes to several tens of minutes at a temperature from normal temperature to about 40 ° C. depending on the surface state of the titanium gas 41. On the other hand, in order to sufficiently perform coarse cotton, you may combine blasting process.

The surface of the acid-treated titanium gas 41 is brought into contact with hot sulfuric acid to finely roughen the inner surface of the titanium crystal grain boundary into a projection shape, and at the same time, the surface of the titanium gas 41 has a thin surface of titanium hydride. To form a layer. The concentrated sulfuric acid to be used is generally suitable at a concentration of 40 to 80% by weight, preferably 50 to 60% by weight, and a small amount of sulfate and the like are used for the purpose of stabilizing the treatment as necessary. You may add. The contact with the hot concentrated sulfuric acid can be usually performed by immersing the titanium gas 41 in a solution of concentrated sulfuric acid, and the solution temperature at that time is generally about 100 to 150 ° C, preferably about 110 to 130 ° C. It can be set as the temperature in the range, and the immersion time is usually about 0.5 to 10 minutes, preferably about 1 to 3 minutes is sufficient. By such a hot concentrated sulfuric acid treatment, the inner surface of the titanium crystal grain boundary can be finely roughened in a projection shape, and a very thin film of titanium hydride can be formed on the surface of the titanium gas 41. The hot concentrated sulfuric acid-treated titanium gas 41 is taken out from the sulfuric acid tank, preferably quenched in an inert gas atmosphere such as nitrogen and argon, and the surface temperature of the titanium gas 41 is lowered to about 60 ° C or lower. For such quenching, it is also suitable to use a large amount of cold water as well as washing.

The pre-treated titanium gas 41 is calcined in the air to thermally decompose the coating layer of titanium hydride to return the titanium hydride in the layer to substantially almost titanium metal, further reducing the titanium in the vicinity of the surface of the titanium gas 41. Can be replaced with titanium oxide in the oxidized state. Such firing can generally be performed by heating at about 300-600 degreeC, Preferably it is about 300 to 400 degreeC about 10 minutes-about 4 hours. As a result, a very thin conductive titanium oxide layer is formed on the surface of the titanium substrate 41. The thickness of the titanium oxide layer is generally in the range of 100 to 1,000 kPa, preferably 200 to 600 kPa, and the composition of the titanium oxide is TiO _x where x is generally 1 <x <2, in particular 1.9 < It is preferred to be in the range of x <2. As another method, the pretreated titanium gas may be added directly to the next step without firing as described above. In this case, during the thermal decomposition treatment in the next step, the coating layer of titanium hydride on the surface of the titanium gas 41 is converted into titanium metal and titanium oxide in a low oxidation state.

Thereafter, the titanium oxide surface on the calcined titanium gas 41 was passed through the intermediate layer 42 by 4 mol% or more of platinum, 37-57 mol% of iridium oxide, 3-11 mol% of rhodium oxide, and 35 mol% of tantalum oxide. It is covered with a catalyst layer 43, which is a composite of more than 53 mol%.

As a platinum compound, an iridium compound, a rhodium compound, and a tantalum compound used here, the compound which decomposes on the conditions described below and converts into platinum, iridium oxide, rhodium oxide, and tantalum oxide, respectively, is specifically, As a platinum compound, platinum chloride, platinum chloride, etc. are mentioned, for example, A platinum chloride is especially suitable. Examples of the iridium compound include iridium chloride, iridium chloride, iridium nitrate, and the like, and iridium chloride is particularly preferable. Furthermore, examples of the rhodium compound include rhodium chloride and rhodium nitrate, and rhodium chloride is particularly suitable. As a tantalum compound, tantalum chloride, a tantalum ethoxide, etc. are mentioned, for example, A tantalum ethoxide is especially suitable.

On the other hand, a lower alcohol is suitable as a solvent for dissolving these platinum compounds, iridium compounds, rhodium compounds, and tantalum compounds to adjust the solution. For example, methanol, ethanol, propanol, butanol, etc., or mixtures thereof.

The total concentration of the platinum compound, the iridium compound, the rhodium compound, and the tantalum compound in the lower alcohol solution is generally in the range of 20 to 200 g / L, preferably 40 to 150 g / L in terms of total metal concentration. When this metal concentration is lower than 20 g / L, catalyst carrying efficiency becomes worse, and when it exceeds 200 g / L, there exists a possibility that problems, such as catalyst activity, carrying strength, and unevenness of a carrying amount, may arise.

In addition, the relative use ratios of the platinum compound, the iridium compound, the rhodium compound and the tantalum compound are in terms of metals, and the platinum compound is generally 4 mol% or more, preferably 5-10 mol%, and the iridium compound is generally 37-57. Mol%, preferably 42-50 mol%, the rhodium compound is generally 3-11 mol%, preferably 4-9 mol%, and the tantalum compound is generally more than 35 mol% and 53 mol% or less, preferably Can be in the range of 42-48 mol%.

The gas which the solution was apply | coated to the titanium oxide layer on the titanium base 41 is dried to the temperature within the range of about 20-150 degreeC as needed, and is baked in oxygen-containing gas atmosphere, for example in air. Firing can be performed by heating to a temperature within the range of generally about 450-600 degreeC, Preferably it is about 500-550 degreeC in suitable heating furnaces, such as an electric furnace, a gas furnace, and an infrared furnace, for example. The heating time can be approximately 5 to 30 minutes, depending on the size of the gas to be fired. By this baking, a platinum-iridium oxide-rhodium oxide-tantalum oxide composite can be supported on the surface of the titanium oxide layer. When a sufficient amount of the platinum-iridium oxide-rhodium oxide-tantalum oxide composite cannot be supported by one supporting operation, the above-described process of application-drying-firing of the solution can be repeated as many times as desired.

Herein, the term "platinum-iridium oxide-rhodium oxide-tantalum oxide complex" refers to a composition in which the four components of platinum, iridium oxide, rhodium oxide and tantalum oxide are mixed or in intimate contact with each other.

7 is a graph showing the relationship between the molar ratio of tantalum oxide to iridium oxide in the catalyst layer 43 and the amount of chlorine produced. In the verification of the present inventors, 0.45 L / min Kanagawa Ken Jigasaki was used for the electrode plates 2 and 4 provided in the electrolytic cell 1 shown in FIG. While passing the tap water of the city, the amount of chlorine produced when energized between the electrode plates 2 and 4 is measured. Since the amount of chlorine produced by energization is also correlated with the amount of hypochlorous acid produced, this measurement result can be used as an index indicating the ability to generate hypochlorous acid before the electrode plates 2 and 4 deteriorate. The current densities between the electrode plates 2 and 4 were six cases ranging from 3.0 A / dm 2 to 20 A / dm 2.

As a result, in the verification by the electrode plates 2 and 4 in which the molar ratio of tantalum oxide to iridium oxide in the catalyst layer 43 was 0.10 to 1.85, the molar ratio of tantalum oxide to iridium oxide was increased at any current density. Even though the amount of chlorine produced was almost unchanged, it was found to be maintained at about 0.6 ppm or much higher. When the amount of chlorine produced is 0.6 ppm or more, as a result, as a general sterilizing water generator used for sterilizing nozzles and toilets of sanitary washing apparatuses, it has been found by the present inventors to obtain a hypochlorous acid having a sufficient concentration at initial performance.

On the other hand, in the verification by the electrodes 2 and 4 in which the molar ratio of tantalum oxide to iridium oxide to 2.31 in the catalyst layer 43 is 2.31, the amount of chlorine decreases rapidly at any current density, particularly, the current density is 3.0 A / d. In the case of m 2 and 5.0 A / dm 2, it is well below 0.6 ppm, and it can be seen that the general sterilizing water generating device is out of the practical area. This is presumably due to the increase in the molar ratio of tantalum oxide to iridium oxide, whereby most of the iridium oxide in the catalyst layer 43 is covered with tantalum oxide, and the iridium oxide function as a catalyst is greatly lost.

In addition, in the electrodes 2 and 4 produced by making the molar ratio of tantalum oxide to iridium oxide in the catalyst layer 43 smaller than 0.10, the supporting force was extremely weak so that the release of iridium oxide could be visually observed before use. Therefore, it was clear that sufficient performance and lifespan could not be obtained, and it could be judged that it was not practical without conducting verification by energization such as this verification. From these verification results, it can be said that the molar ratio of tantalum oxide to iridium oxide in the catalyst layer 43 is preferably 0.10 to 2.31 from the viewpoint of the generation ability of hypochlorous acid.

8 is a graph showing the relationship between the molar ratio of tantalum oxide to iridium oxide in the catalyst layer 43 and the endurance times of the electrode plates 2 and 4. In the verification of the present inventors, while supplying 0.45 L / min of tap water to the electrolytic cell 1 shown in FIG. 4, it energized, repeating pole switching between the electrode plates 2 and 4. Specifically, first, the current is supplied between the electrode plates 2 and 4 at a current density of 15 A / dm 2 for 5 seconds, after which the current is stopped for 1 second. 4) This cycle was repeated, making a series of processes which energize for 5 second at a current density of 15 A / dm <2>, and stopping electricity supply for 1 second after that as 1 cycle. In addition, the applied voltage made the upper limit the voltage through which a predetermined current density flows initially. The term "endurance time" used herein refers to the time from the start of the same cycle until the amount of chlorine produced by energization is less than 0.6 ppm. That is, it is an index indicating the lifetime of the electrode (the time at which hypochlorous acid of sufficient concentration can be continuously obtained as a general sterilizing water generator after starting use).

As a result, in the verification by the electrode plates 2 and 4 of 0.10 to 1.38 in the molar ratio of tantalum oxide to iridium oxide in the catalyst layer 43, as the molar ratio of tantalum oxide to iridium oxide increases, the endurance becomes remarkable. It was found that there was a tendency to improve. This is considered to be the result of the carrying capacity of iridium oxide being improved by the increase of tantalum oxide, and suppression of iridium oxide release, and the electrolytic performance being kept high for a long time.

On the other hand, when the molar ratio of tantalum oxide to iridium oxide of the catalyst layer 43 exceeds 1.38, it turned out that endurance tends to fall on the contrary. And, if the molar ratio is 1.85, the use of the sanitary washing apparatus nozzle or toilet bowl is reduced to 400 hours corresponding to the use for about 10 years. The mechanism of this endurance reduction is estimated as follows. That is, since tantalum oxide is an insulating material, as the tantalum oxide increases, the conductive portion of the catalyst layer may decrease, thereby causing charge concentration to iridium oxide, which becomes a limited conductive portion, thereby degrading iridium oxide. Furthermore, when charge concentration occurs, there is also a concern that a decrease in the valence of iridium oxide, a pressure breakage due to a pressure rise due to excess hydrogen gas generation, excessive heat rise, and the like.

Accordingly, the molar ratio of tantalum oxide to iridium oxide in the catalyst layer 43 is in the range of 0.92 to 1.85 in consideration of the balance between the generation ability of hypochlorous acid and the life of the electrode, and the current between the electrode plates 2 and 4. The density should be 7 A / dm 2 to 20 A / dm 2. When the current density is set to 7 A / dm 2 or less, it is difficult to secure a sufficient hypochlorous acid concentration as the resistance increases, and when the amount exceeds 20 A / dm 2, the acceleration or deterioration due to the charge concentration of iridium oxide described above is eliminated. This is because it becomes remarkable. These unique structures can suppress catalyst deterioration due to iridium oxide detachment even when the polarity change is suppressed to suppress the generation of scale, and performance deterioration by increasing tantalum oxide and charge concentration to iridium oxide. It is possible to provide a practically excellent sterilizing water generating device capable of suppressing deterioration acceleration due to.

The content of tantalum oxide in the catalyst layer 43 is more preferably in the range of 42 mol% to 48 mol%. This is because it is possible to provide a practically excellent sterilizing water generating device capable of achieving a good balance of small size and high life while ensuring sufficient sterilizing performance.

The electrode plates 2 and 4 are more preferably configured to conduct electricity at a current density of 12 A / dm 2 to 17 A / dm 2. This is because it is possible to provide a practically excellent sterilizing water generating device which is more compact and has a long life, while ensuring sufficient sterilizing performance. The content of tantalum oxide in the catalyst layer 43 between the electrode plates 2 and 4 is in the range of 42 mol% to 48 mol%, and the current density at the time of energization is 12 A / dm 2 to 17 A / dm 2, thereby providing chlorine. A very practical and versatile electrode can be obtained in which the amount of generation exhibits a high level exceeding the 2.0 ppm line indicated by the dotted line in FIG. 7, and the endurance time exceeds the 500 hour line indicated by the dotted line in FIG. 8. Moreover, since the content of platinum used to extend the endurance time up to this time can be made small, it also contributes to cost reduction.

FIG. 9 shows the electrode densities of the catalyst layers 43 using the electrode plates 2 and 4 having a content rate of 45 mol%, and the current density and the electrode plates 2 and 4 passing through the electrode plates 2 and 4, respectively. It is a graph showing the relationship with electrode life. In the verification of the present inventors, while supplying 0.45 L / min of tap water to the electrolytic cell 1 shown in FIG. 4, it energized, repeating pole switching between the electrode plates 2 and 4. Specifically, first, the current is energized between the electrode plates 2 and 4 for 5 seconds, after that, the current is stopped for 1 second, and then the current is supplied to the electrode plates 2 and 4 for 5 seconds with the opposite polarity as the last time. Then, this cycle was repeated, making 1 cycle the series process of stopping electricity supply for 1 second. In addition, the applied voltage made the upper limit the voltage through which a predetermined current density flows initially. The term "electrode life" as used herein refers to the time from the start of the same cycle until the amount of chlorine produced by energization is less than 0.6 ppm.

As a result, in the case where the current density flowing between the electrode plates 2 and 4 is set to 500 A / m 2 to 1000 A / m 2 (5 A / dm 2 to 10 A / dm 2), the electrode life is remarkably increased as the current density increases. It can be seen that there is a tendency to improve. On the other hand, at low current densities of less than 500 A / m 2, no more than 0.6 ppm of chlorine is originally produced.

On the other hand, when the current density which flows between the electrode plates 2 and 4 exceeds 1000 A / m <2> (10 A / dm <2>), it turned out that electrode lifetime tends to fall in reverse. This is considered to be accelerated deterioration of iridium oxide by becoming high current density.

Also from this, it is preferable that the current density between the electrode plates 2 and 4 is 7 A / dm <2> -20A / dm <2>.

In addition, the electrode plate used in FIGS. 7-9 was produced as follows.

Titanium gas (t0.5 mm x w100 mm x l100 mm) equivalent to JIS type 1 was washed with alcohol, followed by 2 minutes in an aqueous 8% by weight aqueous hydrofluoric acid solution at 20 ° C, and 3 in a 60% by weight aqueous 60% sulfuric acid solution at 120 ° C. Immerse for minutes. Next, the titanium gas was taken out from the sulfuric acid aqueous solution, and cold water was sprayed and quenched. Furthermore, water was rinsed after immersing in 20 degreeC 0.3 weight% hydrofluoric acid aqueous solution for 2 minutes. After washing with water, heat treatment was performed for 1 hour in an air at 400 ° C to form a thin titanium oxide layer on the surface of the titanium gas.

Then, butanol solution of rhodium chloride adjusted to rhodium concentration 100g / L, butanol solution of iridium chloride adjusted to iridium concentration 200g / L, tantalum ethoxide butanol solution adjusted to tantalum concentration 200g / L, and platinum concentration The butanol solution of chloroplatinic acid adjusted to 200 g / L was respectively measured so that the composition ratio of Pt-Ir-Rh-Ta became mol% shown in Table 1 below, and then diluted with butanol so that the metal conversion concentration of Ir was 50 g / L. To prepare a coating solution.

0.27 ml of this solution was pipetted, which was applied to the titanium oxide layer and dried at room temperature for 20 minutes. After drying, the mixture was further calcined for 10 minutes in an atmosphere of 550 ° C. This application-drying-firing process was repeated six times to prepare an electrode shown in Table 1 on which a platinum-iridium oxide-rhodium oxide-tantalum oxide composite was supported on the titanium oxide layer.

Composition of Electrocatalyst Layer (mol%) Ta / Ir Ta Ir Pt Rh 0.23 12% 52% 29% 7% 0.46 21% 46% 26% 6% 0.92 35% 38% 21% 5% 1.38 45% 33% 18% 4% 1.85 52% 28% 16% 4% 2.31 58% 25% 14% 3%

Next, in the case of increasing the tantalum oxide contained in the catalyst layer 43 of the electrode plates 2 and 4 in the present invention, FIG. 10 shows a mechanism in which the detachment reaction of iridium oxide from the electrode is suppressed and the durability is improved. It demonstrates with and FIG. Fig. 10 is a schematic cross-sectional view of an electrode plate schematically showing a mechanism in which the electrode plate deteriorates when the pole switching in the comparative example is performed, and Fig. 11 schematically shows a mechanism in which the electrode plate deteriorates when the pole switching in the present invention is performed. It is a cross-sectional schematic diagram of the electrode plate shown normally.

As a general mechanism when electrolysis is performed in the electrode plate, the polarity of the electrode plate on the anode side, which has been generating chlorine before the pole switching, is polarized, thereby changing the polarity to the cathode side. By doing so, a different reaction occurs on the surface of the electrode than in the case of the anode, thereby deteriorating the electrode. Specifically, iridium oxide (IrO ₂ ) having tetravalent iridium present in the catalyst layer of the electrode plate is reduced, thereby eluting to iridium oxide (Ir ₂ O ₃ ) having trivalent iridium. Usually, it is thought that such reaction occurs gradually from the polar surface of the catalyst layer, so that iridium oxide, which functions as a catalyst, is eluted and reduced step by step at the polar surface of the catalyst layer, and deterioration of the electrode plate proceeds by decreasing the amount of chlorine produced. And the reaction which generate | occur | produces on the surface of the cathode side electrode plate which shows such a mechanism is shown by Formula (1). In addition, the "pole surface" as used here means the molecular layer located in the outermost surface of a catalyst layer.

_{^{IrO 2 + 2H + + 2e -}} ⇒Ir 2 O 3 + H 2 O ... (One)

By the way, in Fig less tantalum oxide carrying an IrO ₂ in the same catalyst bed shown in Comparative Example 10 (no more than 35 mole%), the electrode plate, a chlorine production is disposed of in a short period of time to reduce the degradation proceeds rapidly. This is as shown in (A) 10, the tantalum oxide is thought to be a state in which to discard, without exposure to the coating IrO ₂ causes. When the exposed IrO ₂ not present on the surface of the electrode becomes Ir ₂ O ₃ due to the reduction reaction and is eluted, as shown in FIG. 10 (B), IrO ₂ that does not occur on the surface of the reduction occurs. The supporting force for the titanium gas 41 is lost. And, it is considered a case, as shown in 10 (C), a reduction reaction that is IrO ₂ 're entirety departure occur. As a result, much more iridium oxide is eluted than iridium oxide is eluted stepwise at the polar surface, so that the function of the iridium oxide as a catalyst is largely lost, and the deterioration of the electrode plate proceeds more quickly.

On the other hand, in Fig. 11 corresponding to the embodiment of the present invention, the amount of tantalum oxide in the catalyst layer is increased by a predetermined amount (more than 35 mol%). This state is shown schematically in FIG. 11A, whereby the tantalum oxide enhances the supporting force between the titanium gas 41 and iridium oxide.

In Fig. 11B, even in the case where a reduction reaction of iridium oxide occurs in a portion other than the pole surface of the catalyst layer, since the tantalum oxide which does not function as a catalyst remains without leaving, the oxidation that was present on the pole surface Iridium does not escape before it produces chlorine. For this reason, as shown in FIG.11 (C), the iridium oxide of an extreme surface can exert the function of a catalyst, without eluting. Thereby, the time which can generate | occur | produce chlorine becomes long, and it becomes possible to provide an electrode plate with high durability.

On the other hand, as mentioned above, when tantalum oxide is excessively increased (58 mol% or more), most of the iridium oxide of a catalyst layer is coat | covered with tantalum oxide, and it is estimated that the function as a catalyst of iridium oxide is largely impaired. . For this reason, the increase in a predetermined range is suitable for increasing the tantalum oxide.

12 is a principle explanatory diagram showing changes in pH in the vicinity of the electrode plate when the intervals between pole switching are different. In order to prevent adhesion of the scale to the electrode plates 2 and 4 with increased tantalum oxide, the energization time to the electrode plate until the pole switching, which is a control for switching the positive electrode and the negative electrode of the electrode plate with a constant energizing time, is performed. Are set to 10 seconds, 30 seconds, and 60 seconds, respectively.

In this FIG. 12, the comparative example in which the electrode plate containing a lot of tantalum oxide was energized in the state of high current density, and the energization time until switching to pole is set to 60 second is demonstrated.

When the energization time is relatively long (60 seconds), the pH near the electrode plate is biased. For this reason, the pH of the vicinity of the anode side before the pole switching is lowered. This is considered to be an environment where metals are easily corroded, and it is thought that separation of iridium oxide becomes remarkable. The release of iridium oxide is thought to further promote charge concentration and deterioration to the remaining iridium oxide.

Therefore, in the present invention, the electrode plates 2, 4 containing a lot of tantalum oxide are energized in a high current density state, and the constant energization time until the pole switching is shortened to 30 seconds. As a result, even if the polarity is changed in the electrode plate in which the tantalum oxide content is increased, catalyst deterioration due to detachment of iridium oxide and detachment of iridium oxide can be suppressed.

Moreover, since generation | occurrence | production of scale can be greatly reduced by making polar switching into less than 30 second, scale adhesion to iridium oxide can be suppressed. Since the scale is an insulating material, excessive adhesion to iridium oxide reduces the conduction portion to further concentrate the charge on specific iridium oxide without scale adhesion, but inhibiting scale adhesion can significantly reduce deterioration of the electrode plate even by increasing tantalum oxide. Will be.

In addition, it is possible to prevent the pH in the vicinity of the anode side before the polar shift can be prevented, so that the polar shift can be performed in an environment where metal is hard to corrode, and performance deterioration due to the increase of tantalum oxide or charge to iridium oxide. It can suppress deterioration promotion by continuing to concentrate.

On the other hand, although the energization time until the polarization is not shown, for example, in an extremely short case such as 3 seconds, while the charge to the iridium oxide is not concentrated, the chlorine is not stably generated between the energizing plates. The polarity of is changed and the possibility of not being able to stabilize the amount of chlorine generated is considered.

Therefore, in the present invention, more preferably, the constant energization time until the polar change is 4 to 15 seconds, so that even if the electrode plate contains a lot of tantalum oxide in the catalyst layer, By suppressing the charge concentration of, it is possible to control the release of iridium oxide.

Furthermore, it is possible to prevent the pH near the anode side from being too low before the polar change, and to achieve a certain chlorine generating ability, while the polar change can be performed in an environment where metal is hard to corrode, thereby increasing tantalum oxide. It is possible to suppress deterioration of performance due to application and deterioration due to charge concentration to iridium oxide, and to provide a sterilizing water generator having an optimal balance of long life while ensuring sufficient sterilization performance.

On the other hand, in the embodiment of the present invention, as a sterilizing water generating device, the sanitary washing device is applied to, for example, water containing chloride ions, such as bathrooms, kitchens, medical equipment and vending machines that require a clean environment. Any product can be applied as long as it is capable of generating sterile water by electrolysis.

1: electrolyzer 2, 4: electrode plate
10: euro system 12: water source
14: cleaning nozzle 16: flow path
18: discharge passage 20: branch portion
22: discharge passage 24: control unit
26: pump 28: cleaning valve
30: discharge valve 32: discharge mechanism
41: titanium gas (electrode gas) 42: intermediate layer
43: catalyst layer 100: sanitary washing apparatus
110: toilet 120: toilet

Claims (8)

In the sterilized water generating device for directly generating electrolytic water containing chloride ions to generate chlorine at the positive electrode, and to generate sterilized water of hypochlorous acid by the reaction of the chlorine and water,
An electrode provided with a catalyst layer on an electrode body made of titanium or a titanium alloy provided in an electrolytic cell through which water containing chloride ions pass;
Control means for energizing the electrode to generate hypochlorous acid in the electrolytic cell,
The catalyst layer of the electrode consists of a complex of metals and / or metal oxides comprising at least iridium oxide and tantalum oxide,
The composite contains more than 35 mol% of tantalum oxide in terms of metal, and contains tantalum oxide of 0.92 to 1.85 times in molar ratio with respect to iridium oxide,
And said control means is configured to energize said electrode at a current density of 7 A / dm 2 to 20 A / dm 2. The method of claim 1,
The complex is a sterilizing water generating device further comprises rhodium oxide. 3. The method of claim 2,
The composite further contains platinum, sterilized by containing 4 mol% or more of platinum, 37-57 mol% of iridium oxide, 3-11 mol% of rhodium oxide, and 35 mol% of tantalum oxide, and 53 mol% or less. Number generating device. The method of claim 3, wherein
Tantalum oxide of the catalyst layer is a sterilizing water generating device, characterized in that the mixture is 42 to 48 mol%. The method according to any one of claims 1 to 4,
The control means is a sterilizing water generating device, characterized in that configured to energize the electrode at a current density of 12A / dm 2 ~ 17A / dm 2, The method of claim 5, wherein
Wherein the water containing chloride ions supplied to the electrolytic cell is of a water-soluble type which does not circulate water. The method according to claim 6,
And the control means is configured to perform a polarity switching for switching the positive electrode and the negative electrode of the electrode at intervals within 30 seconds with respect to the electrode. The method of claim 7, wherein
The control means is a sterilizing water generator, characterized in that for performing the polarity switching to switch the polarity of the electrode to the positive electrode and the negative electrode at intervals of 4 to 15 seconds with respect to the electrode.

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