JPH078959A - Electrolytic water forming device - Google Patents

Abstract

PURPOSE:To lower the bonding speed of scale to the surface of an electrode, to facilitate the removal of scale due to washing and to stably use the electrode for a long period of time. CONSTITUTION:A platinum layer 22 with a thickness of 0.3-1mum is formed on a Ti base material 20 having a smooth surface and an interface layer 24 of oxide containing platinum is arranged to the boundary part of the Ti base material 20 and the platinum layer 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrolyzed water generator which produces alkaline water and acid water by electrolyzing water used mainly as drinking water in an electrolyzer.

[0002]

2. Description of the Related Art Conventionally, as this type of electrolyzed water generator, FIG.
There are those shown in. This electrolyzed water generator is shown in FIG.
As shown in the schematic view of (a), it is composed of a purification cartridge portion for purifying raw water supplied from a water supply or the like, and an electrolytic tank portion for electrolyzing purified raw water (purified water).

First, the raw water flowing into the electrolyzed water generator is filtered by the hollow fiber filter 50 in the water purification cartridge,
Fine particles and microorganisms in raw water are removed. Further, the activated carbon 52 reduces the hypochlorous acid added for killing the microorganisms such as bacteria and converts it into chlorine ions, and also removes the chlorine odor. The purified water obtained by being purified in this way flows into the electrolytic cell section. This electrolytic cell section is composed of a diaphragm 54, an anode 56 and a cathode 58.
Here, the purified water is electrolyzed by applying a DC voltage or a full-wave rectified AC voltage between both electrodes, acidic water is generated on the anode side, and alkaline water is generated on the cathode side. .

The electrodes installed in the electrolytic cell are shown in FIG. 3 (b).
In order to secure the adhesiveness of the surface layer of the electrode to the electrode base material, the surface of the Ti base material, which is the electrode base material, is subjected to surface treatment by etching or blasting treatment so as to produce irregularities, as shown in FIG. The surface of the Ti base material subjected to the treatment was coated with platinum, platinum alloys and oxides thereof, and the electrode surface itself was uneven.

In such an electrolyzed water generator, the electrolysis strength is switched by changing the value of the DC voltage applied between the electrodes or the number of pulses of the AC voltage subjected to full-wave rectification, and the p-level is changed in several steps.
Electrolyzed water having an H value can be obtained. In addition, after a certain amount of raw water is passed through the electrolytic treatment, in order to remove the scale mainly composed of sodium, calcium, potassium, magnesium, etc. adhering to the electrodes, while passing water for a certain period of time, The electrode surface is cleaned by reversing the polarity of the voltage applied between the electrodes.

[0006]

However, in the conventional electrolyzed water generator, scale is deposited and deposited on the cathode and its vicinity during electrolysis with the generation of electrolyzed water, resulting in deterioration of electrolysis capacity. . When an electrode having irregularities on the surface is used, the scale deposition rate becomes high, and at the same time, the removal of the scale by cleaning becomes particularly incomplete in the recesses, resulting in a problem that the life of the electrode is shortened.

The present invention has been made in order to solve the above-mentioned problems, and has a low rate of scale adhesion to the electrode surface, easy removal of scale by washing, and stable use of the electrode for a long period of time. It is an object of the present invention to provide an electrolyzed water generator that can be used.

[0008]

In order to achieve this object, the electrolyzed water generator of the present invention comprises applying an electric voltage to an electrode provided in an electrolyzer to electrolyze the water so that alkaline water or In an electrolyzed water generator that generates acidic water, the electrode is formed on a conductive base material and the conductive base material,
In addition, it is formed by an interface layer made of an oxide containing a noble metal, and a noble metal layer or a noble metal alloy layer coated on the interface layer.

[0009]

According to the electrolyzed water generator of the present invention having the above structure, an interface layer made of an oxide containing a noble metal is formed on a conductive substrate, and a noble metal layer or a noble metal alloy layer is formed on the interface layer. Since the electrode is formed by coating with, the adhesive force of platinum or platinum alloy to the conductive substrate is sufficiently secured even when the conductive substrate having a smooth surface is used.

[0010]

An embodiment of an electrolyzed water generator embodying the present invention will be described below with reference to the drawings.

The electrolyzed water generator has substantially the same structure as the conventional one, and has an electrolytic cell having a structure in which an anode 10 and a cathode 12 are separated by a diaphragm 14 for electrolysis as shown in FIG. 1 (a). 10 and the cathode 12 are installed so that the distance between the electrodes is constant. A flow path 16 is connected to the outlet side of the electrolytic cell section so that the electrolyzed water generated on the anode side and the electrolyzed water generated on the cathode side are separated so as not to mix.

The electrode has a structure as shown in FIG. 1B, and a noble metal having a thickness of 0.3 μm to 1 μm is formed on a Ti base material 20 which constitutes a conductive base material having a smooth surface form. A platinum layer 22 forming a layer is formed, and an interface layer 24 of an oxide containing platinum is provided at a boundary portion between the Ti base material 20 and the platinum layer 22. The platinum-containing oxide interface layer 24 is preferably made of PtO, PtO ₂ , oxides or cermets containing Ti or Ta added thereto, or conductive oxides containing Ir, and the thickness thereof. Is several nm to several tens of nm.

Next, the manufacturing process of the electrode of this embodiment is shown in FIG. For the Ti base material 20 which is the base material of the electrode, a material corresponding to JIS type 1 or type 2 is used, and after the machining step 26 of cutting to the size of the electrode is applied, to remove the stains on the surface Degreasing 28 is performed. In the degreasing step 28, an alkaline degreasing liquid containing sodium hydroxide, sodium carbonate, a surfactant and the like is used. In the etching step 30, the natural oxide film layer existing on the surface of the Ti base material 20 is removed by an etching solution containing oxalic acid to clean the surface. In the water washing step 32, the etching liquid and the dissolved dirt are washed off, and then, the drying step 34 dries.
In the subsequent oxide layer forming step 36, the platinum-containing oxide interface layer 24 is formed to a desired thickness on the dried Ti substrate 20. Further, the platinum layer forming step 38 forms the platinum layer 22 on the interface layer 24 of the oxide containing platinum. The platinum layer 22 and the interfacial layer 24 of platinum-containing oxide are formed by a well-known method such as a sputtering method or an ion plating method that utilizes an impact effect of a high energy particle on a growing film surface.

Here, the formation of the oxide-containing interfacial layer 24 containing platinum by the sputtering method will be briefly described.

Ti substrate 20 obtained through the above-mentioned steps
Are held on the electrode in an atmosphere of Ar of several millitorr to several tens of millitorr and oxygen. A target made of platinum and an additive such as Ti or Ta is installed on an electrode facing this electrode, and a discharge is generated between both electrodes by applying direct current or high frequency power between both electrodes. . By the reactive sputtering performed in such an atmosphere containing oxygen, the interface layer 24 of an oxide containing platinum is formed on the Ti base material 20. In this case, the growing platinum-containing oxide interface layer 24 is always bombarded with high-energy particles. Therefore, the film surface is always cleaned, the shape of the surface is deformed in a microscopic sense, and the surface energy is kept high. That is, the oxide interface layer 24 containing platinum, which has high adhesiveness, is formed on the Ti base material 20.

Further, an interfacial layer 2 of an oxide containing platinum
4 is formed, a reverse sputtering process is performed in which electric power is applied to the electrode on which the Ti base material 20 is installed so that the surface of the Ti base material 20 is sputter cleaned. Adhesive force of the platinum-containing oxide to the Ti base material 20 is obtained by performing bias sputtering treatment that accelerates the impact effect of high-energy particles on the growing film surface by applying electric power to the electrode on which the material 20 is installed. Will improve further.

After the oxide-containing interface layer 24 containing platinum having a desired thickness is formed in this manner, platinum is sputtered in an Ar atmosphere to form a platinum-containing oxide interface layer 24 on the oxide-containing interface layer 24. A platinum layer 22 is formed. By the way, when forming the oxide interface layer 24 containing platinum, after forming the oxide interface layer 24 containing platinum of a desired thickness, the supply of oxygen to the discharge region is gradually reduced. As a result, a transition region having a continuous composition change from the oxide layer to the metal layer is formed, and the adhesion of the platinum layer 22 formed thereafter is improved.

As described above, a platinum electrode based on Ti having a smooth surface morphology can be obtained.

Next, the operation of the electrolyzed water generator of this embodiment will be described.

The raw water flowing into the electrolytic cell is divided into the anode side and the cathode side by the diaphragm 14. Here, a predetermined voltage is applied to the anode 10 and the cathode 12, a current flows through the diaphragm 14, and at the same time, the divided raw water is electrolyzed.
In this case, the applied voltage is about 30V. Then, on the anode side, H ⁺ is mainly generated and the raw water becomes acidic water, while on the cathode side, OH ⁻ is mainly generated and the raw water becomes alkaline water. These electrolyzed water are separately taken out of the electrolyzed water generator by the flow paths 16 connected to the outlet side of the electrolyzer.

By the way, on the cathode side where alkaline water is produced, calcium ions, magnesium ions, sodium ions and the like contained in water are deposited and grow on the cathode 12 as a scale. When the total amount of water flow reaches a certain amount, a voltage having the opposite polarity to that during electrolysis is applied to the anode 10 and the cathode 12 in order to remove the scale adhering to the cathode 12. When the polarity is reversed, the electrode that worked as the cathode during electrolysis acts as the anode, acidic water is generated near the cathode 12, and the scale containing calcium, magnesium, sodium, etc. as the main component dissolves, and the electrode is washed. Is done. In this case, since the surface of the electrode is smooth, the rate of scale deposition on the surface of the cathode 12 during electrolysis is low, and the scale can be easily removed by washing. Therefore, the electrode can be cleaned by cleaning in a short time, the amount of waste water generated during this time can be reduced, and the electric power required in the reverse polarity can be reduced.

[0022]

As is clear from the above description, according to the electrolyzed water generator of the present invention, the electrode is made of a conductive base material,
The electrode surface is formed by the interface layer formed on the conductive base material and made of an oxide containing a noble metal, and the noble metal layer or the noble metal alloy layer coated on the interface layer. It can be made smooth, the rate of scale attachment to the electrode surface is low, the scale can be easily removed by washing, and the electrode can be used stably for a long period of time.

[Brief description of drawings]

FIG. 1 (a) is a plan view schematically showing the vicinity of the electrolytic cell of the present invention. (B) It is a top view which shows the structure of the electrode of this invention typically.

FIG. 2 is a process drawing showing a manufacturing process of an electrode of the present invention.

FIG. 3 (a) is a plan view showing a configuration of a main part of a conventional electrolyzed water generator. (B) It is a top view which shows the structure of the conventional electrode typically.

[Explanation of symbols]

 10 Anode 12 Cathode 20 Ti Base Material 22 Platinum Layer 24 Interface Layer

Claims (1)

[Claims] 1. An electrolyzed water generator for producing alkaline water or acidic water by applying a voltage to an electrode provided in an electrolysis tank to perform electrolysis of water, wherein the electrode is a conductive base material. An interface layer formed on the conductive base material and made of an oxide containing a noble metal,
An electrolyzed water generator formed by a noble metal layer or a noble metal alloy layer coated on the interface layer.