JP6835379B1 - Manufacturing method of titanium substrate coated electrode for electrolysis - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a titanium substrate-coated electrode for electrolysis, which can make the amount of a carrier uniform and exhibit a predetermined electrode performance. SOLUTION: A coating step of applying a coating solution containing a platinum group metal compound and / or a metal compound other than a platinum group metal and a solvent onto a titanium substrate forming an electrode substrate, and the coating solution are applied. A drying step of drying the titanium substrate to evaporate the solvent, and heating the titanium substrate after the drying step in an oxygen-containing gas atmosphere to thermally decompose the applied metal compound to form a metal and / or metal. In the method for producing a titanium substrate-coated electrode for electrolysis including a thermal decomposition step of changing to an oxide, the coating step, the drying step, and the thermal decomposition step are repeated a plurality of times, and the coating step is a platinum group metal compound. And / or a coating solution prepared by dissolving a metal compound other than a platinum group metal in a solvent having a relative dielectric constant of 29 to 50 and a surface tension of 0.029 to 0.050 Nm-1 was positively charged by applying a voltage of 14 to 16 kV. The coating liquid is pushed out from the nozzle, and 99% or more of the coating liquid amount is atomized with a particle size of 80 to 200 μm by a repulsive force and adhered to the grounded surface of the titanium substrate. [Selection diagram] None

Description

The present invention relates to a method for manufacturing a titanium substrate-coated electrode for electrolysis. More specifically, the present invention relates to a method for producing a titanium substrate-coated electrode for electrolysis in which a solution containing a platinum group metal salt is applied onto a titanium substrate, dried, and thermally decomposed to form an electrode catalyst layer.

As a method for producing a titanium substrate-coated electrode for electrolysis, there are a plating method, a sputtering method, a thermal decomposition method (coating, drying, and thermal decomposition of a solution containing a catalyst component).

In Patent Document 1, a predetermined amount of a butanol solution of iridium chloride and an ethanol solution of tantalum chloride are mixed in order to provide an outer layer composed of a mixed metal oxide composed of iridium oxide and a metal oxide of tantalum oxide. It is described that after preparing a coating solution, a predetermined amount of this coating solution is applied and fired. Conventionally, this coating has been performed mainly by a brush coating method.

Japanese Patent Application Laid-Open No. 2-190491

When a coated electrode is manufactured by coating, drying, and thermal decomposition using a large titanium substrate and pressed to obtain a small piece-shaped electrode, the average amount of platinum group metal carrier supported is 0.2 g · dm ^{-2, especially in terms of metal.} When the following catalyst layers are manufactured by a coating method such as brush coating or dipping, the value obtained by dividing the amount of one small piece of carrier by the average amount of carrier varies, so that the design life is less than the lower limit of the carrier that can be obtained. There is a problem that the production cost increases because it is necessary to increase the average amount of the carrier so as not to prevent it.
In electrostatic coating, the repulsive force of the applied liquid suppresses the bias of the liquid and makes the film uniform, but the surface area of the atomized coating liquid is large and is affected by hydrolysis due to moisture in the air. However, there is a problem that the predetermined electrode performance cannot be obtained.
When a high voltage is applied to the coating liquid, the solvent is positively charged, and when it is pushed out from the nozzle, it is separated into fine particles by repulsive force and adheres to the lower grounded titanium substrate surface. Usually, when the coating liquid is atomized and brought into contact with air, there is a problem that the durability of the produced electrode is significantly deteriorated due to the strong influence of hydrolysis or the like due to the moisture in the air.

Therefore, an object of the present invention is to provide a method for producing a titanium substrate-coated electrode for electrolysis, which can make the amount of a carrier uniform and exhibit predetermined electrode performance.

As a result of diligent studies to achieve the above problems, the present inventors specifically increase the particle size of the coating liquid to be atomized by applying a high voltage and using a specific solvent in the electrostatic coating method. As a result, they have found that the influence of contact between the mist-like coating liquid and the moisture in the air can be suppressed, and have reached the present invention.
That is, by applying a high voltage and using a solvent having a relative permittivity of 29 to 50 and a surface tension of 0.029 to 0.050 Nm- ¹ , the particle size of the mist-like coating liquid is specifically increased in the air. We have developed this manufacturing method that can stabilize the life characteristics of individual electrodes by suppressing the influence of moisture and reducing the variation in the amount of carried on each of the small piece-shaped electrodes.

That is, the above problem is
A coating step of applying a coating solution containing a platinum group metal compound and / or a metal compound other than a platinum group metal and a solvent onto a titanium substrate forming an electrode substrate.
A drying step of drying the titanium substrate to which the coating liquid is applied to evaporate the solvent, and
A titanium substrate for electrolysis including a thermal decomposition step of heating the titanium substrate after the drying step in an oxygen-containing gas atmosphere to thermally decompose the applied metal compound into a metal and / or a metal oxide. In the method of manufacturing a coated electrode
The coating step, the drying step, and the thermal decomposition step are repeated a plurality of times (a series of steps including these steps are repeated a plurality of times).
In the coating step, the voltage is 14 to 16 kV in a coating solution prepared by dissolving a platinum group metal compound and / or a metal compound other than the platinum group metal in a solvent having a relative permittivity of 29 to 50 and a surface tension of 0.029 to 0.050 Nm- ^1. Is applied, and the positively charged coating liquid is pushed out from the nozzle, and 99% or more of the coating liquid amount is atomized with a particle size of 80 to 200 μm by repulsive force, and the surface of the titanium substrate after the pretreatment step is grounded. It is achieved by a method for manufacturing a titanium substrate-coated electrode for electrolysis, which is a step of adhering to a metal.

Further, the solvent of the coating liquid may contain 2ethoxyethanol or a solvent in which 50 wt% or less thereof is replaced with a lower alcohol.

Further, in the coating step, the inner diameter of the nozzle may be 0.1 to 0.3 mm, and the amount of the coating liquid to be extruded may be 0.01 to 0.03 mL / sec.

Further, the amount of the platinum group metal carried by the titanium substrate-coated electrode for electrolysis is 0.2 g · dm ^-2 or less in terms of metal, and
A press working step of pressing out the titanium substrate-coated electrode for electrolysis to obtain a small piece-shaped electrode may be further included.

Further, in the above manufacturing method, the titanium substrate has a rectangular plate shape, and in the coating step, dielectric plates are installed in parallel on each of the long sides of the rectangle of the titanium substrate through predetermined voids. The coating liquid may be applied in this state.

According to the present invention, it is possible to provide a method for producing a titanium substrate-coated electrode for electrolysis, which can make the amount of a carrier uniform and exhibit predetermined electrode performance.

That is, by applying a high voltage and using a specific solvent to increase the particle size of the mist-like charged coating liquid, it is possible to achieve both uniform support and stabilization of electrode life characteristics. The specific solvent is, for example, a solvent in which 2ethoxyethanol or 50 wt% or less thereof is replaced with a lower alcohol. When a coated electrode is manufactured by electrostatic coating, drying, and thermal decomposition using a large plate titanium substrate and pressed to obtain a small piece-shaped electrode, the amount of supported material on the small piece-shaped electrode is small, so the average Even if the amount of the carrier is reduced, the minimum amount of the carrier can secure the required amount of the carrier, so that the manufacturing cost can be reduced.
Further, when the average amount of the carrier is the same as that of the brush coating, the lower limit amount of the small piece shape by the electrostatic coating method increases, so that the electrode life can be extended. That is, the design life can be extended without increasing the material cost. The design life referred to here is the life of the electrode having the lower limit of the amount of the carrier. In particular, when a catalyst layer having a platinum group metal carrier amount of 0.2 g · dm ^-2 or less in terms of metal is produced, the above effect becomes remarkable.

Hereinafter, the method for producing the titanium substrate-coated electrode for electrolysis of the present invention will be described in more detail.

<Electrode substrate>
Examples of the material of the electrode substrate used in the present invention include titanium equivalent to JIS Class 1 or JIS Class 2. For example, a large plate titanium substrate (t 0.5 mm × w 500 mm × l 1000 mm) can be used as an electrode substrate.

<Titanium substrate pretreatment process>
In order to improve the adhesion of the titanium substrate, the surface of the substrate is treated in a pretreatment step as necessary. The pretreatment step can take any one or more of the following acid treatment, titanium hydride treatment, and titanium oxide formation, for example.

(Acid treatment)
It is desirable that the electrode substrate as described above is preliminarily acid-treated as is usually performed. Preferable specific examples of such pretreatment include those described below. First, the surface of the titanium substrate described above is washed with, for example, alcohol, acetone, etc. and / or degreased by electrolysis in an alkaline solution according to a conventional method, and then hydrofluoric acid having a hydrogen fluoride concentration of 1 to 20% by weight or By treating with a mixed acid of hydrofluoric acid and other acids such as nitric acid and sulfuric acid, the oxide film on the surface of the titanium substrate is removed and the surface of the titanium crystal grain boundary unit is roughened. The acid treatment can be carried out at room temperature to about 40 ° C. for several minutes to ten and several minutes depending on the surface condition of the titanium substrate.

(Titanium hydride treatment)
The surface of the titanium substrate treated with acid in this way is brought into contact with concentrated sulfuric acid to finely roughen the inner surface of the titanium crystal grain boundaries in a protruding shape and to form a thin layer of titanium hydride on the surface of the titanium substrate. The concentrated sulfuric acid used is generally 40 to 80% by weight, preferably 50 to 60% by weight, and if necessary, a small amount of sodium sulfate or the like is used for the purpose of stabilizing the treatment. Sulfate and the like may be added. Contact with the concentrated sulfuric acid can usually be performed by immersing the titanium substrate in a bath of concentrated sulfuric acid, and the bath temperature at that time is generally in the range of about 100 to about 150 ° C., preferably about 110 to about 130 ° C. The temperature can be set to the inside temperature, and the immersion time is usually about 0.5 to about 10 minutes, preferably about 1 to about 3 minutes. By this sulfuric acid treatment, the inner surface of the titanium crystal grain boundaries can be finely roughened like protrusions, and a very thin titanium hydride film can be formed on the surface of the titanium substrate. The sulfuric acid-treated titanium substrate is taken out of the sulfuric acid bath and rapidly cooled in an atmosphere of an inert gas such as nitrogen or argon to lower the surface temperature of the titanium substrate to about 60 ° C. or lower. It is appropriate to use a large amount of cold water for this rapid cooling, which also serves as cleaning.

The titanium substrate having a very thin titanium hydride film layer formed on the surface in this way is immersed in a dilute hydrofluoric acid or dilute fluoride aqueous solution (for example, an aqueous solution of sodium fluoride, potassium fluoride, etc.). Then, the titanium hydride film is grown to make the film uniform and stable. The concentration of hydrogen fluoride in the dilute hydrofluoric acid or dilute fluoride aqueous solution that can be used here can be generally in the range of 0.05 to 3% by weight, preferably 0.3 to 1% by weight. Further, the temperature at the time of the immersion treatment with these solutions can be generally in the range of 10 to 40 ° C, preferably 20 to 30 ° C. The treatment can be carried out until a uniform film of titanium hydride having a thickness of usually 0.5 to 10 microns, preferably 1 to 3 microns is formed on the surface of the titanium substrate. Since this titanium hydride (TiHy, where y is a number of 1.5 to 2) exhibits a grayish brown to dark brown color depending on the degree of hydrogenation, the formation of a titanium hydride film having a thickness in the above range is not possible. Empirically, the change in color tone on the surface of the substrate can be controlled by contrasting the brightness with a standard color source.

(Formation of titanium oxide)
The titanium substrate is then heated in the air, if necessary. This heating can be generally carried out by heating at a temperature of about 300 to about 600 ° C., preferably about 300 to about 400 ° C. for about 10 minutes to 4 hours. By this heating, the layer of the titanium hydride film is thermally decomposed, and the titanium hydride in the layer is substantially returned to the titanium metal, and a very thin conductive titanium oxide is formed on the surface of the titanium substrate. The thickness of the titanium oxide is generally preferably in the range of 10 to 100 nm, preferably 20 to 60 nm, and the composition of titanium oxide is such that x is generally 1 <x <2, particularly 1.9 as TiOx. It is desirable that it is in the range of <x <2. Alternatively, the titanium substrate may be directly subjected to the next step without heating as described above. In this case, the layer of the titanium hydride film on the surface of the titanium substrate is converted into titanium metal and titanium oxide in a low oxidation state during the thermal decomposition treatment in the next step. In this way, electrically conductive titanium oxide (passivation film) is formed, and chemical stability can be enhanced.

The pretreatment step of the titanium substrate is not limited to the above, and various treatment steps can be adopted.

As the pretreatment step of the titanium substrate, surface area expansion and roughening by blasting can be adopted. Pickling can be performed with other acids such as hot oxalic acid and concentrated hydrochloric acid.

Next, the coating step, the drying step, and the thermal decomposition step are repeated a plurality of times, for example, three times to prepare an electrode catalyst layer.

In the preparation of the electrode catalyst layer, the metal compound used in the coating liquid may be a platinum group metal compound only, a platinum group metal compound, or a metal compound other than the platinum group metal.

Depending on the electrode, an intermediate layer may be provided on the titanium substrate, and an electrode catalyst layer may be formed on the intermediate layer. In that case, the coating step, the drying step, and the thermal decomposition step are repeated once or a plurality of times to prepare an intermediate layer.

When the intermediate layer is produced, the metal compound used in the coating liquid may be only a platinum group metal compound, only a non-platinum group metal compound, or a platinum group metal compound or a non-platinum group metal compound. is there.

That is, when the electrode catalyst layer is formed on the electrode substrate, the coating liquid is other than the platinum group metal compound and / or the platinum group metal, including the case where the intermediate layer is prepared in advance and the electrode catalyst layer is formed on the intermediate layer. Includes metal compounds and solvents.

<Coating liquid>
The coating liquid contains a platinum group metal compound and / or a metal compound other than the platinum group metal, and a solvent ^{having a relative permittivity of 29 to 50 and a surface tension of 0.029 to 0.050 Nm-1.} As the solvent, for example, a solvent containing at least one of 2ethoxyethanol, dimethyl sulfoxide, ethylene glycol, and dimethylformamide can be used. Further, a solvent in which 50 wt% or less of those solvents is replaced with a lower alcohol can be used.
For example, a solvent in which 2ethoxyethanol or 50 wt% or less thereof is replaced with a lower alcohol can be used. The lower alcohol can include at least one of ethanol, isopropyl alcohol and butanol. Further, a metal compound other than the platinum group metal may be contained.

As the platinum group metal compound and the metal compound other than the platinum group metal, for example, a platinum compound, an iridium compound and a tantalum compound can be used. Here, the platinum compound, the iridium compound, and the tantalum compound are compounds that can be decomposed under predetermined conditions and converted into platinum, iridium oxide, and tantalum oxide, respectively, and examples of the platinum compound include platinum chloride acid, platinum chloride, and dinitro. Examples include diammine platinum. Examples of the iridium compound include iridium chloride, iridium chloride, potassium iridium chloride and the like. Further, examples of the tantalum compound include tantalum chloride, tantalum ethoxide and the like.

<Applying process of coating liquid>
A voltage of 14 to 16 kV was applied to the surface of the titanium substrate after the pretreatment step of the titanium substrate, and the positively charged coating liquid was extruded from a nozzle with an inner diameter of 0.1 to 0.3 mm at a coating liquid volume of 0.01 to 0.03 mL / sec, and repulsive force was applied. 99% or more of the coating liquid amount is atomized with a particle size of 80 to 200 μm, preferably 100 to 200 μm, and adhered to the grounded titanium substrate surface.

It is considered that the relative permittivity of the solvent and the surface tension are greatly involved in increasing the particle size of the coating liquid to be atomized, but it is indispensable that the platinum group metal compound can be dissolved as the coating liquid.

Table 1 shows the relative permittivity and surface tension values of 2ethoxyethanol and the like.

When the particle size of the coating liquid is smaller than 80 μm, it is easily affected by hydrolysis or the like due to moisture in the air. On the other hand, if the particle size exceeds 200 μm, the amount of protrusion at the end of the titanium substrate increases and the coating efficiency deteriorates.

Further, in the above manufacturing method, the titanium substrate has a rectangular plate shape, and in the coating process, dielectric plates are installed in parallel on each of the long sides of the rectangle of the titanium substrate through predetermined voids. , The coating liquid can be applied.

In the electrostatic coating device for performing the coating step, the nozzle pushes out the coating liquid from the nozzle while moving relative to the titanium substrate to apply the coating liquid onto the titanium substrate. In the coating process, it is preferable to apply evenly only on the titanium substrate, and it is desired to avoid adhering to other parts of the device or the side surface and the back surface of the titanium substrate as much as possible.

Therefore, in the coating process, it is conceivable to place a shielding plate on each of the long sides of the rectangle of the titanium substrate, which is a rectangular plate, via a predetermined gap. However, when a metal plate is placed as the shielding plate, a positive potential (14) ~ 16kV) The lines of electric force emitted from the nozzle are vertically incident on the metal titanium substrate, but since they are also input vertically to the metal of the shielding plate that is not directly under the nozzle, the electricity of the shielding plate other than the titanium substrate is charged. The lines of force also become dense. Therefore, the shielding plate is made of a dielectric material. The relative permittivity of the dielectric is, for example, 2 to 10. As the dielectric, for example, an acrylic plate is used. Since the lines of electric force emitted from the nozzle do not vertically enter the dielectric material that is not directly under the nozzle but enter diagonally, the lines of electric force of the portion of the shielding plate other than the titanium substrate are relatively sparse. Therefore, the ratio of the coating liquid reaching other than the titanium substrate decreases, and as a result, the ratio of the coating liquid adhering to the side surface and the back side of the titanium substrate decreases.

<Drying process>
The titanium substrate to which the coating liquid containing the platinum group metal compound, the metal compound other than the platinum group metal, and the solvent is coated is generally dried at a relatively low temperature in the range of about 20 to about 100 ° C. and the solvent. Evaporate much or most of the solvent. For example, dry at room temperature.

<Pyrolysis process>
The titanium substrate after the drying step is heated in an oxygen-containing gas atmosphere to thermally decompose the applied metal compound and change it into a metal and / or a metal oxide.

Specifically, the titanium substrate after the drying step is heated in an oxygen-containing gas atmosphere, for example, in air. The heating can be carried out in a suitable heating furnace such as an electric furnace, a gas furnace, an infrared furnace or the like in a temperature generally in the range of about 450 to about 650 ° C, preferably about 500 to about 600 ° C. The heating time can be about 3 to 30 minutes depending on the size of the substrate. For example, it can be heated in the air at 550 ° C for 10 minutes. By this heating, the platinum group metal compound and the metal compound other than the platinum group metal are thermally decomposed to form a metal, a metal oxide, or a composite of the metal and the metal oxide.

<Pressing process>
The large titanium substrate on which the electrode catalyst layer is formed is pressed out to prepare a small piece-shaped electrode having a predetermined size.

In the electrode catalyst layer, the amount of the platinum group metal carrier is not particularly limited, and electrodes having various platinum group metal carriers can be produced. In particular, the present production method is suitable for producing an electrode having an average amount of platinum group metal carrier of 0.2 g · dm ^{-2 or less in terms of metal.} That is, in the present manufacturing method, after the coated electrode is manufactured by coating, drying, and thermal decomposition using a large plate titanium substrate, the amount of the carrier of each small piece-shaped electrode manufactured by pressing is reduced. This is because the required amount of carrier can be secured even if the average amount of carrier is reduced. Further, when the average carrier amount is the same, the lower limit carrier amount of each of the small piece-shaped electrodes is increased as compared with the case of brush coating, so that the design life can be extended.

Hereinafter, the present invention will be described in more detail with reference to Examples.

(Example 1)
After washing a large titanium plate (t 0.5 mm x w 500 mm x l 1000 mm) equivalent to JIS Class 1 with alcohol, in an 8 wt% hydrofluoric acid aqueous solution at 20 ° C for 2 minutes, and in a 60 wt% sulfuric acid aqueous solution at 120 ° C. Treated for 3 minutes. Then, the titanium substrate was taken out from the sulfuric acid aqueous solution, and cold water was sprayed and rapidly cooled. Further, it was immersed in a 0.3 wt% hydrofluoric acid aqueous solution at 20 ° C. for 2 minutes and then washed with water. After washing with water, it was heat-treated in the air at 400 ° C. for 1 hour to form a thin titanium oxide intermediate layer on the surface of the titanium substrate.

Next, a voltage of 15 kV was applied to a 2ethoxyethanol coating solution adjusted to an iridium concentration of 60 g / L (iridium: tantalum = 1: 1) using iridium chloride and tantalum ethoxydo to apply a positively charged coating solution. It was placed downward from a φ0.2 mm nozzle at 0.025 mL / sec and extruded toward the grounded titanium substrate. The extruded coating liquid became mist-like particles (see Table 1 for particle size) by repulsive force and adhered to the intermediate layer on the surface of the titanium substrate. At this time, the nozzle was moved at 100 mm / sec and adhered to the entire intermediate layer on the upper surface of the titanium substrate. It was then dried at room temperature and further heated in the air at 550 ° C for 10 minutes. After repeating this coating, drying, and thermal decomposition three times, the electrode of Example 1 was prepared.

(Example 2)
The electrode of Example 2 was prepared in the same manner as in Example 1 except that the solvent of the coating liquid was 2ethoxyethanol: isopropyl alcohol = 1: 1 (weight ratio).

(Comparative Example 1)
The electrode of Comparative Example 1 was prepared in the same manner as in Example 1 except that the solvent of the coating liquid was ethanol, the Ir concentration was changed to 30 g / L, and the coating / drying pyrolysis was repeated 6 times.

(Comparative example 2)
The electrode of Comparative Example 2 was prepared in the same manner as in Example 1 except that the solvent of the coating liquid was butanol and a single coating amount of 23 ml was applied with a brush.

The particle size of the mist-like coating liquid was determined by photographing the mist-like particles with image analysis software. The results are shown in Table 2.

The electrodes thus obtained were pressed out to prepare 660 small piece-shaped (t 0.5 mm × w 15 mm × l 40 mm) electrodes. The amount of these Ir carriers was measured with a Keiko X-ray film thickness meter, and the minimum carrier amount, the maximum carrier amount, the average carrier amount, and the standard deviation were determined.

The results are shown in Table 2.

In addition, the small piece electrodes of Examples 1 and 2 and Comparative Examples 1 and 2 having the minimum amount of Ir carrier were electrolyzed in an accelerated test of 200 A · dm ^{-2 in} _{a 1 M H 2} SO ₄ + 1 M Na ₂ SO _{4 aqueous solution at room temperature.} Table 3 shows the life when it is used. Here, the life means the time until the cell voltage becomes twice the initial voltage.

In Example 1 in which 2ethoxyethanol was used as a solvent and in Example 2 in which 50 wt% of 2ethoxyethanol was replaced with isopropyl alcohol in a small piece electrode having a minimum Ir carrying amount, ethanol was used as a solvent. The electrode life is longer than that of Comparative Example 1. In addition, in the small piece electrode with the minimum Ir-carrying amount, Examples 1 and 2 have a longer electrode life than Comparative Example 2 coated with a brush. Further, the particle size occupying 99% or more of the coating liquid amount of Example 1 is 100 to 200 μm, and the particle size occupying 99% or more of the coating liquid amount of Example 2 is 80 to 180 μm, and the particle size of Comparative Example 1 is It is considered that the electrode life was extended because the influence of hydrolysis due to moisture in the air could be suppressed, which was larger than that of 20 μm or less.
Further, in Examples 1 and 2, the standard deviation of the amount of the Ir carrier of the small piece electrode is smaller than that of Comparative Example 2 coated with a brush, the variation in the amount of the carrier of the catalyst layer is suppressed, and the uniformity is achieved, and the average. Although the supported amount is as small as about 90%, the minimum Ir-supported amount can be increased, so that the life of the small piece electrode with the minimum Ir-supported amount is extended.

Claims (5)

A coating step of applying a coating solution containing a platinum group metal compound and / or a metal compound other than a platinum group metal and a solvent onto a titanium substrate forming an electrode substrate.
A drying step of drying the titanium substrate to which the coating liquid is applied to evaporate the solvent, and
A titanium substrate for electrolysis including a thermal decomposition step of heating the titanium substrate after the drying step in an oxygen-containing gas atmosphere to thermally decompose the applied metal compound into a metal and / or a metal oxide. In the method of manufacturing a coated electrode
The coating step, the drying step, and the thermal decomposition step are repeated a plurality of times, and
In the coating step, the voltage is 14 to 16 kV in a coating solution prepared by dissolving a platinum group metal compound and / or a metal compound other than the platinum group metal in a solvent having a relative permittivity of 29 to 50 and a surface tension of 0.029 to 0.050 Nm- ^1. Is applied, and the positively charged coating liquid is pushed out from the nozzle, and 99% or more of the coating liquid amount is atomized with a particle size of 80 to 200 μm by repulsive force and adhered to the grounded titanium substrate surface. A method for manufacturing a titanium substrate-coated electrode for electrolysis, which is characterized by the above. The method for producing a titanium substrate-coated electrode for electrolysis according to claim 1, wherein the solvent of the coating liquid contains 2ethoxyethanol or a solvent in which 50 wt% or less thereof is replaced with a lower alcohol. The method for producing a titanium substrate-coated electrode for electrolysis according to claim 1 or 2, wherein in the coating step, the inner diameter of the nozzle is 0.1 to 0.3 mm and the amount of the coating liquid to be extruded is 0.01 to 0.03 mL / sec. The amount of platinum group metal carried by the titanium substrate-coated electrode for electrolysis is 0.2 g · dm ^-2 or less in terms of metal, and
Further including a press working step of pressing out the titanium substrate-coated electrode for electrolysis to obtain a small piece-shaped electrode.
The method for manufacturing a titanium substrate-coated electrode for electrolysis according to any one of claims 1 to 3. The titanium substrate has a rectangular plate shape and has a rectangular plate shape.
Claims 1 to 4 are characterized in that, in the coating step, the coating liquid is applied in a state where dielectric plates are installed in parallel on each of the long sides of the rectangle of the titanium substrate via predetermined voids. The method for manufacturing a titanium substrate-coated electrode for electrolysis according to any one of.