JP2018155603A - Method for producing silver-silver chloride electrode - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a silver/silver chloride electrode short in the time taken to reach a stable state by being thrown into the sea water, suppressing deterioration of the silver/silver chloride electrode, and high in sensitivity in the measurement of intensity of the electric field.SOLUTION: A manufacturing method of a silver/silver chloride electrode includes: a formation step of forming a silver powder forming body; a sintering step of sintering the silver powder forming body; and a surface chlorination step of chloritizing the surface of a sintered compact having a sintered silver powder. The silver powder comprises agglomerated particles whose spherical equivalent diameter is equal to or more than 30 μm and less than 150 μm, and a particle size of a single particle configuring the agglomerated particles is equal to or more than 1 μm and less than 50 μm, and a spherical equivalent diameter of the integrated weight 50% of the agglomerated particles is equal to or more than 70 μm and less than 100 μm, and contains more than 20 wt% and less than 35 wt% of the agglomerated particles whose aspect ratio is equal to more than 2.0 and less than 2.5 and contains more than 5 wt% and less than 10 wt% of the agglomerated particles whose aspect ratio is more than 2.5 and less than 5.0.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a method for producing a silver-silver chloride electrode for measuring electric field strength in seawater or soil.

  As a silver-silver chloride electrode for measuring the electric field strength in sea water or soil, a silver-silver chloride electrode by a sintering method is used. This electrode is obtained by compression-molding silver powder and chlorinating the surface of the compression-molded molded body.

  As a silver-silver chloride electrode, those disclosed in Patent Documents 1 and 2 are known. In the techniques of Patent Documents 1 and 2, a silver-silver chloride electrode composed of a silver-silver chloride mixed powder sintered body and a silver plate integrally bonded to one side is used.

  As a method for producing a silver-silver chloride electrode, one disclosed in Patent Document 3 is known. In the technique of Patent Document 3, a conductive paste composed of silver oxide having a particle diameter of 1 μm or more and 2 μm or less, silver chloride having a particle diameter of 1 μm or more and 2 μm or less, and a heat resistant paste is printed on an alumina substrate. A method of producing a silver-silver chloride electrode prepared by baking at 10 ° C. for 10 minutes is used.

  As a method for manufacturing a biomedical electrode, one disclosed in Patent Document 4 is known. In the technique of Patent Document 4, a method of manufacturing a biomedical electrode in which a conductive electrode base and a mixture of silver, silver chloride and boron oxide are pelletized and then supported on the electrode base is used. Patent Document 4 exemplifies an anodizing method, a sintering method, a paste method, and the like as a method for producing a silver-silver chloride electrode.

  Moreover, what was disclosed by the nonpatent literature 1 and 2 is known as a silver-silver chloride electrode which measures bioelectric potential. In the techniques of Non-Patent Documents 1 and 2, an electrode obtained by chlorinating the surface of silver having a thin wire shape or a disk shape is used. These electrodes are used to measure a weak current in a living body.

JP-A-5-176903 JP-A-5-176904 Japanese Patent Laid-Open No. 5-142189 JP 2006-280735 A

WARNER INSTRUMENTS “Ag / AgCl Pellet, Disc and Wire Electrodes; Silver Wire” BaSi “Silver / Silver Chloride Reference Electrode” Tomono Honma and Toshimichi Watanabe “Bioelectric potential measurement and potential fluctuation in tea tree” (summary) Osaka University Graduate School of Medicine / Graduate School of Life Sciences “History of Bioelectric Signal Research”

  As the silver-silver chloride electrode, those disclosed in Patent Documents 1 to 4 and Non-Patent Documents 1 and 2 are known. However, there are many things which are not premise used as a silver-silver chloride electrode which measures the electric field strength in seawater or soil.

  Here, a silver-silver chloride electrode having a dried surface is put into seawater. In a silver-silver chloride electrode having fine open pores, seawater penetrates deeply into the open pores, the surface of the particles is uniformly wetted, the potential difference between the pair of silver-silver chloride electrodes is reduced, and a stable state is reached. In order to be in this stable state, the conventional silver-silver chloride electrode has a problem that requires a long time.

  Further, when the silver-silver chloride electrode is thin, it is suitable for measuring the electric field intensity in a region where a weak current of μA level flows. However, in the region where a current of mA or more flows, there is a problem that the intergranular corrosion proceeds rapidly and the silver-silver chloride electrode is consumed quickly.

  Furthermore, in the conventional silver powder, since the diameter of the particles is small, a large number of closed pores are formed, and the specific surface area of the compact that contributes to the measurement of the electric field strength cannot be increased. Here, the closed pore is a cavity having no opening on the surface of the molded body. For this reason, it is difficult to reduce the detectable electric field strength. For this reason, there existed a subject that the sensitivity in the measurement of the electric field strength of a silver-silver chloride electrode was low.

  The present invention is for solving the above-mentioned problems, and it takes a short time to reach a stable state after being put into seawater, the deterioration of the silver-silver chloride electrode is suppressed, and the sensitivity in measuring the electric field strength is high. It aims at obtaining the manufacturing method of a high silver-silver chloride electrode.

  (1) The method for producing a silver-silver chloride electrode according to the present invention comprises a molding step for molding a silver powder compact, a sintering step for sintering the silver powder compact, and the sintered silver. And a surface chlorination step of chlorinating the surface of the powder sintered body, wherein the silver powder is composed of aggregated particles having a sphere equivalent diameter of 30 μm or more and 150 μm or less. The particle size of single particles constituting the particles is 1 μm or more and 50 μm or less, the sphere equivalent diameter of the accumulated weight 50% of the aggregated particles is 70 μm or more and 100 μm or less, and the aspect ratio is over 2.0 and 2.5 or less The composition includes 20 to 35% by weight of the aggregated particles and 5 to 10% by weight of the aggregated particles having an aspect ratio of more than 2.5 and 5.0 or less.

Here, the reason why the spherical equivalent diameter is composed of aggregated particles of 30 μm or more is to avoid that the pores of the chlorinated surface of the sintered body of silver powder become too small and the permeation rate of seawater decreases. It is.
The reason why the spherical equivalent diameter is composed of aggregated particles having a diameter equal to or less than 150 μm is to maintain a surface area and a low level of contact resistance with seawater with respect to a predetermined thickness of the sintered body of silver powder.
The reason why the particle size of the single particles is 1 μm or more is that when isolated, the pores are easily clogged with a relatively small amount.
The reason why the particle size of the single particles is 50 μm or less is that if the particle size is too large, it is difficult to mold and there is a limitation in the production process of the silver powder.
The reason why the equivalent sphere diameter of the aggregate weight of 50% of the aggregated particles is 70 μm or more is to avoid that the pore diameter becomes too small and the permeation rate of seawater decreases.
The reason why the equivalent sphere diameter of the aggregate weight of 50% of the aggregated particles is 100 μm or less is to avoid the decrease in the surface area of the silver powder compact and the sensitivity as an electrode.
The reason for including aggregated particles having an aspect ratio exceeding 2.0 and not more than 2.5 is that when particles having a large aspect ratio are mixed, the filling rate can be lowered and the pore volume can be increased.
The reason why 20% by weight or more of aggregated particles having an aspect ratio of more than 2.0 and less than 2.5 is contained is that the effect of lowering the filling rate is lowered when the ratio is lowered.
The reason why 50% by weight or less of aggregated particles having an aspect ratio of more than 2.0 and not more than 2.5 is included is that, if too much, it is difficult to mold and there is a limitation in the production process of silver powder.
The reason for the inclusion of agglomerated particles having an aspect ratio of more than 2.5 and not more than 5.0 is that when long particles having a large aspect ratio are mixed, the filling rate is lowered while maintaining the strength of the molded body, and the pore volume is reduced. It is because it can raise.
The reason for containing 5% by weight or more of aggregated particles having an aspect ratio of more than 2.5 and not more than 5.0 is that when the ratio is lowered, the effect of maintaining the strength of the molded body is small.
The reason why 10% by weight or less of aggregated particles having an aspect ratio of more than 2.5 and less than 5.0 is included is that when the amount is too much, on the contrary, it becomes difficult to mold.

  (2) In the forming step, the formed body of the silver powder is compression-molded, and in the sintering step, the thickness of the sintered body of the silver powder is formed to be 2 mm or more and 3 mm or less.

The reason why the thickness of the sintered body of the silver powder is 2 mm or more is to suppress a decrease in the adhesive strength of the silver wire when compression molding is performed while a silver wire having a diameter of 1 mm is incorporated as a lead wire.
The reason why the sintered body of silver powder is formed to have a thickness of 3 mm or less is to avoid that it takes time for the seawater to penetrate into the pores and that it takes time to reach a stable state.

  (3) In the molding step, a silver wire or strip-shaped silver whose tip is chemically treated is inserted into the molded body of the silver powder and molded integrally.

  (4) In the forming step, the formed body of the silver powder is formed on a base material.

  (5) As the base material, silver or a metal plate with a small ionization tendency in seawater having electrical characteristics close to this, and the molded body of the silver powder formed on the base material in the molding step The thickness is from 0.3 mm to 1.0 mm.

(6) As the substrate, a porous or ceramic plate to which the silver powder is easily attached is used.
The thickness of the compact of the silver powder formed on the base material in the molding step is 0.3 mm to 1.0 mm.

The reason why the thickness of the silver powder compact is 0.3 mm or more is to avoid a decrease in surface area and sensitivity as an electrode.
The reason why the thickness of the silver powder molded body is 1.0 mm or less is to avoid the time from becoming long until the potential difference between the pair of electrodes is stabilized due to the penetration rate of seawater.

According to the method for producing a silver-silver chloride electrode according to the present invention, no special mechanism is required for storage and maintenance, and when the surface is installed in seawater from a dried state, the seawater quickly enters the pores. It is possible to manufacture a silver-silver chloride electrode that permeates into the substrate and operates stably in a short time.
In addition, a silver chloride thin film layer can be formed deep inside the pores, and a silver-silver chloride electrode can be manufactured in which deterioration is suppressed even when the detection signal level is large.
Furthermore, it is possible to produce a silver-silver chloride electrode that is small in size and has a small interval between electrodes and higher sensitivity in measurement of electric field strength than a conventional electrode.

It is a flowchart figure which shows the manufacturing method of the silver-silver chloride electrode which concerns on Embodiment 1 of this invention. It is a figure which shows the cross-sectional photograph of the silver-silver chloride wire from which a part of silver chloride layer peeled off. It is a figure which shows the SEM photograph of the silver powder in Example 1 of Embodiment 1 of this invention. It is a figure which shows the SEM photograph of the silver powder in the comparative example 2 of Embodiment 1 of this invention. It is a figure which shows the SEM photograph of the silver powder in the comparative example 3 of Embodiment 1 of this invention. It is a figure which shows the characteristic of the silver-silver chloride electrode in Example 1, 2 of Embodiment 1 of this invention, and Comparative Examples 1-3. It is explanatory drawing which shows the cross section of the structure of the silver-silver chloride electrode which concerns on Embodiment 2 of this invention. It is a figure which shows the characteristic of the silver-silver chloride electrode in Examples 3-6 of Embodiment 1 of this invention, and Comparative Examples 4 and 5. FIG. It is a figure which shows the relationship between the thickness of the silver-silver chloride electrode in Examples 3-6 of Embodiment 2 of this invention, and Comparative Examples 4 and 5, and a stable time.

  Embodiments of the method for producing a silver-silver chloride electrode according to the present invention will be described below. In addition, the form of drawing is an example and does not limit this invention. Moreover, what attached | subjected the same code | symbol in each figure is the same, or is equivalent to this, and this is common in the whole text of a specification. Furthermore, in the following drawings, the relationship between the sizes of the constituent members may be different from the actual one.

Embodiment 1 FIG.
The silver-silver chloride electrode manufacturing method uses silver powder having the following composition. Specifically, the silver powder is composed of aggregated particles having a sphere equivalent diameter of 30 μm to 150 μm. In the silver powder, the particle size of single particles constituting the aggregated particles is 1 μm or more and 50 μm or less. The silver powder has a spherical equivalent diameter of 70% to 100 μm with a cumulative weight of 50% of the aggregated particles. The silver powder contains 20% by weight or more and 35% by weight or less of aggregated particles having an aspect ratio exceeding 2.0 and 2.5 or less. The silver powder has a composition containing 5% by weight or more and 10% by weight or less of aggregated particles having an aspect ratio of more than 2.5 and 5.0 or less.

FIG. 1 is a flowchart showing a method for producing a silver-silver chloride electrode according to Embodiment 1 of the present invention.
As shown in FIG. 1, the method for producing a silver-silver chloride electrode includes a forming step, a sintering step, and a surface chlorination step. Hereinafter, it demonstrates in order of each process.

(Molding process)
In the molding step, a compact of silver powder having the above composition is compression molded. Further, in the molding step, a silver wire whose tip is chemically treated is inserted into a molded body of silver powder and molded integrally.
Instead of a silver wire having a chemically treated tip, strip-shaped silver having a chemically treated tip may be inserted into a molded body of silver powder and molded integrally.

Specifically, the tip of a silver wire having a diameter of 1 mm as a lead wire is bent within a range smaller than the size of the silver-silver chloride electrode. The bent portion and the silver wire extending from the bent portion to the lead portion are boiled and washed with alcohol such as methyl alcohol or ethyl alcohol.
Next, the bent portion and the lead portion of the silver wire are immersed in a 5 to 20 wt% nitric acid aqueous solution at 50 to 70 ° C. for about 3 minutes.
The silver wire washed with pure water is annealed in an electric furnace at 450 to 600 ° C. for 5 minutes.
Using a mold, this bending portion and the silver powder having the above composition are integrally molded to a predetermined thickness at a molding pressure of 1.5 MPa or less. Thereby, a molded body of silver powder is obtained.

(Sintering process)
In the sintering process, the silver powder compact is sintered. In the sintering step, the thickness of the silver powder sintered body is formed to be 2 mm or more and 3 mm or less.

  Specifically, the silver powder compact is sintered in an electric furnace at 450 to 600 ° C. for 15 minutes. Thereby, the sintered compact of the silver powder formed in thickness 2 mm or more and 3 mm or less is obtained.

(Surface chlorination process)
In the surface chlorination step, the surface of the sintered silver powder sintered body is chlorinated.

  Specifically, in the case of producing a silver-silver chloride electrode for measuring the electric field strength in the sea, a silver powder sintered body is placed on the anode in a sodium chloride aqueous solution of about 3.5% by weight and the silver electrode. Is placed on the cathode, and a direct current of 5 to 20 mA is applied for about 24 hours to form a silver chloride film on the surface of the sintered body of silver powder. Thereby, the surface of the sintered body of silver powder is chlorinated.

  In the case of a silver-silver chloride electrode for measuring the electric field strength in the soil, a sintered body of silver powder is disposed at the anode and the silver electrode is disposed at the cathode in an approximately 3.8% by weight potassium chloride aqueous solution. A direct current of 5 to 20 mA is applied for 20 hours or more to form a silver chloride film on the surface of the sintered body of silver powder. Thereby, the surface of the sintered body of silver powder is chlorinated.

(Function, effect)
Generally, particles formed and sintered have pores having a diameter proportional to the average particle diameter of the constituent particles. It is known that the amount of liquid leakage from a pinhole or the like is proportional to the fourth power of the hole diameter and inversely proportional to the viscosity.
Based on the formula of this analysis example, the permeation rate in the pores in seawater is calculated. For example, when the pore diameter is 1 μmφ, the infiltration rate of seawater is about 0.16 μm / s in the sea at a depth of 50 m.
On the other hand, when the pore diameter is 10 μmφ, the penetration speed of seawater is about 16 μm / s in the sea at a depth of 50 m, which is 100 times that when the pore diameter is 1 μmφ.
That is, if the average pore diameter when composed of particles having an average particle diameter of 6 μm is about 1 μmφ, the average pore diameter when composed of particles having an average particle diameter of 60 μm is about 10 μmφ, It turns out that it becomes 1/100 of the case where it consists of a particle with an average particle diameter of 6 micrometers.

In the method for producing a silver-silver chloride electrode according to Embodiment 1, the sphere equivalent diameter is composed of aggregated particles having a diameter of 30 μm or more and 150 μm or less, and the particle size of single particles constituting the aggregated particles is 1 μm or more and 50 μm or less. A silver powder having a composition with a sphere equivalent diameter of 70% to 100 μm and a cumulative weight of aggregated particles of 50% is used. Thereby, the pore diameter after shaping | molding and sintering this silver powder can be enlarged.
Here, when the equivalent sphere diameter is smaller than 30 μm, the generated pore diameter becomes too small, the permeation rate of seawater decreases, and it takes time to stabilize as a pair of electrodes. On the other hand, if the equivalent sphere diameter exceeds 150 μm, the surface area of the silver powder compact decreases, so that the detectable electric field strength increases and the sensitivity decreases.
Further, when the particle size of the single particles is smaller than 1 μm, the pores can be easily blocked with a relatively small amount when isolated. On the other hand, when the particle size of the single particles exceeds 50 μm, if the particle size is too large, it is difficult to mold, and the production process of silver powder is limited.
Furthermore, when the equivalent sphere diameter of the aggregate weight of 50% of the aggregated particles is smaller than 70 μm, the pore diameter becomes too small, the seawater permeation rate decreases, and it takes time to stabilize as a pair of electrodes. It will be. On the other hand, when the sphere equivalent diameter of the aggregate weight of 50% of the aggregated particles exceeds 100 μm, the surface area of the silver powder compact becomes small and the sensitivity as an electrode is lowered.

In the method for producing a silver-silver chloride electrode according to Embodiment 1, the silver-silver chloride electrode contains 20 wt% or more and 35 wt% or less of aggregated particles having an aspect ratio of more than 2.0 and 2.5 or less, and Silver powder having a composition containing 5 wt% or more and 10 wt% or less of aggregated particles having an aspect ratio of more than 2.5 and 5.0 or less is used. Thereby, the filling property at the time of shaping | molding improves by the blocking effect, the shrinkage | contraction and densification at the time of sintering are prevented, the pore diameter after sintering can be maintained, and many open pores on the surface can be maintained. In addition, the thickness of compression molding can be reduced while using silver powder having a large sphere equivalent diameter.
Here, the aspect ratio is the ratio of the major axis to the minor axis of the aggregated particles (= major axis / minor axis). Spherical particles having a particle size distribution tend to have high packing properties. It is well known that when spheres with a particle size ratio of 1:10 are mixed, the maximum packing density is reached when particles with a small particle size have a mixing ratio of 20 to 30% by weight, and the pores contained therein are reduced. It has been. On the other hand, when long particles having a large aspect ratio are mixed, the filling rate can be lowered and the pore volume can be increased while maintaining the strength of the compact.
Here, in the case of containing aggregated particles having an aspect ratio exceeding 2.0 and not more than 2.5, if particles having a large aspect ratio are mixed, the filling rate can be lowered and the pore volume can be increased. When the agglomerated particles having an aspect ratio of more than 2.0 and less than 2.5 are contained in an amount of less than 20% by weight, the ratio becomes too low and the effect of reducing the filling rate is lowered. On the other hand, in the case where the aggregated particles having an aspect ratio of more than 2.0 and less than 2.5 are contained in excess of 35% by weight, if the amount is too much, it is difficult to mold, and it is caught by restrictions on the production process of silver powder. End up.
In addition, in the case of containing aggregated particles having an aspect ratio of more than 2.5 and 5.0 or less, if long aggregated particles having a large aspect ratio are mixed, the filling rate is lowered while maintaining the strength of the molded product. , The pore volume can be increased. When the agglomerated particles having an aspect ratio of more than 2.5 and less than 5.0 are contained in an amount of less than 5% by weight, if the ratio is too low, the effect of maintaining the strength of the molded product is reduced. On the other hand, when it contains more than 10% by weight of aggregated particles having an aspect ratio of more than 2.5 and less than 5.0, if it is too much, it becomes difficult to mold.

In the method for producing a silver-silver chloride electrode according to Embodiment 1, the silver-silver chloride electrode uses silver powder having a composition containing 5% by weight or more of aggregated particles having an aspect ratio of more than 2.5 and 5.0 or less. Thus, silver powder having a large equivalent sphere diameter can be used. Thereby, the thickness of the sintered compact of the silver powder which compresses and sinters, incorporating the silver wire of diameter 1mm as a lead wire, can be formed in 2 mm or more and 3 mm or less.
When long aggregate particles having a large aspect ratio are mixed, the filling rate can be lowered while maintaining the strength of the silver powder compact, and the thickness of the silver powder sintered body can be reduced to 3 mm or less. When the thickness of the sintered body of silver powder is 2 mm or less, there is a drawback that the adhesive strength of the silver wire as the lead wire inserted into the silver-silver chloride electrode is lowered. On the other hand, when the equivalent sphere diameter exceeds 150 μm, the adhesive strength further decreases.

  In the method for producing a silver-silver chloride electrode according to Embodiment 1, a silver wire or strip-shaped silver whose tip is chemically treated is inserted into a molded body, integrally molded, sintered, and silver-chlorinated. A silver electrode is manufactured. Thereby, the adhesive strength of the lead wire of the silver-silver chloride electrode can be increased.

In the case where a conventional silver powder is compression-molded and the surface thereof is chlorinated, the average particle diameter of the silver-silver chloride electrode is as small as 4 μm or more and 8 μm or less. For this reason, the average pore diameter of the conventional silver-silver chloride electrode is also as small as 0.7 μm or more and 1.3 μm or less. Therefore, when a conventional silver-silver chloride electrode having a dry surface is introduced into seawater, the seawater penetrates deeply into the pores and the particle surface is uniformly wetted, so that the gap between the pair of silver-silver chloride electrodes The potential difference is reduced, and it takes a long time to reach a stable state.
On the other hand, in the silver-silver chloride electrode produced by the method for producing a silver-silver chloride electrode according to Embodiment 1, the average pore diameter is as large as 4 μm or more and 10 μm or less. Therefore, when a silver-silver chloride electrode with a dry surface is put into seawater, the seawater penetrates deeply into the pores and the particle surface is uniformly wetted, and the potential difference between the pair of silver-silver chloride electrodes is It takes a short time to reach a stable state as it becomes smaller.

Moreover, the average pore diameter of the conventional silver-silver chloride electrode is as small as 0.7 μm or more and 1.3 μm or less, and the packing density is high. For this reason, the ratio which occupies for the surface of an open pore was also small. Such a conventional silver-silver chloride electrode cannot increase the specific surface area of the molded article that contributes to the measurement of electric field strength. Therefore, to increase the sensitivity, the area of the silver-silver chloride electrode has to be increased.
On the other hand, in the silver-silver chloride electrode manufactured by the method for manufacturing a silver-silver chloride electrode according to Embodiment 1, the average pore diameter is as large as 4 μm or more and 10 μm or less as described above. Therefore, the specific surface area of the molded body that contributes to the measurement of the electric field strength can be increased. Therefore, it is not necessary to increase the area of the silver-silver chloride electrode in order to increase sensitivity, and the size can be reduced.

Further, the conventional silver powder has a large number of closed pores because the particle diameter is small and the packing density is high. For this reason, the specific surface area of the molded body contributing to the measurement of the electric field strength cannot be increased, and it has been difficult to reduce the detectable electric field strength. Here, the closed pore means a cavity having no opening on the surface of the molded body.
On the other hand, in the silver-silver chloride electrode produced by the method for producing a silver-silver chloride electrode according to Embodiment 1, the diameter of the silver powder particles is as large as 30 μm or more and the packing density is low. Can be suppressed. For this reason, the specific surface area of the molded body contributing to the measurement of the electric field strength can be increased, and the detectable electric field strength can be reduced. Therefore, the sensitivity is high.

FIG. 2 is a view showing a cross-sectional photograph of a silver-silver chloride wire in which a part of the silver chloride layer is corroded and peeled off.
A conventional thin-line silver-silver chloride electrode is suitable for measuring the electric field strength in a region where a weak current of μA level flows. However, as shown in FIG. 2, in this electrode, in the region where a current of mA or more flows, the intergranular corrosion rapidly proceeds and the silver-silver chloride electrode is consumed quickly.
On the other hand, in the silver-silver chloride electrode produced by the method for producing a silver-silver chloride electrode according to Embodiment 1, the area of the junction between the particles is large, so even in a region where a current of μA level or more than mA flows. The progress of intergranular corrosion is alleviated and the durability of the silver-silver chloride electrode is improved.

In the conventional method for producing a silver-silver chloride electrode, the method of directly fixing the end of the lead wire to the sintered body with the silver paste has a low adhesive strength of the lead wire, and the lead wire may be peeled off.
On the other hand, in the silver-silver chloride electrode manufactured by the method for manufacturing a silver-silver chloride electrode according to the first embodiment, since it is sintered integrally with the particles, the lead wire has high adhesive strength and the lead wire is peeled off. It is difficult to improve the durability of the silver-silver chloride electrode.

As mentioned above, according to the manufacturing method of the silver-silver chloride electrode which concerns on Embodiment 1, when a special mechanism is not required for storage and maintenance management, and when it installs in the seawater from the state which dried the surface It is possible to produce a silver-silver chloride electrode in which seawater quickly penetrates into the pores and operates stably in a short time.
In addition, a silver chloride thin film layer can be formed deep inside the pores, and a silver-silver chloride electrode can be manufactured in which deterioration is suppressed even when the detection signal level is large.
Furthermore, since the distance between the electrodes is small and the distance between the electrodes is small, it is easy to specify the position of the target object even at a relatively short distance. Moreover, since the specific surface area is large and the potential difference between the pair of electrodes is very small, it is possible to produce a silver-silver chloride electrode whose sensitivity in measuring the electric field strength is 1000 times higher than that of the conventional electrode.

Example 1
FIG. 3 is a diagram showing an SEM photograph of the silver powder in Example 1 of Embodiment 1 of the present invention.
The silver powder of Example 1 shown in FIG. 3 has the same composition as that of Embodiment 1. The silver powder of Example 1 is composed of aggregated particles having a sphere equivalent diameter of 30 μm to 140 μm. The silver powder of Example 1 has a spherical equivalent diameter of 89 μm with a cumulative weight of 50% of the aggregated particles. Further, the silver powder of Example 1 has an average particle diameter of 26 μm when dispersed with a 40 W homogenizer. The silver powder of Example 1 contained 7.8% by weight of aggregated particles having an aspect ratio of more than 2.5 and 5.0 or less. Using this silver powder, a molded body having a diameter of 25 mm was prepared, sintered, and a silver-silver chloride electrode having a silver chloride film formed on the surface thereof was prepared. The thickness of this electrode was 3.1 mm.

(Example 2)
Using the same silver powder as in Example 1, a molded body having a diameter of 25 mm was prepared, sintered, and a silver-silver chloride electrode having a silver chloride film formed on the surface thereof was prepared. The thickness of this electrode was 2.9 mm.

(Comparative Example 1)
Using the same silver powder as in Example 1, a molded body having a diameter of 25 mm was prepared, sintered, and a silver-silver chloride electrode having a silver chloride film formed on the surface thereof was prepared. The thickness of this electrode was 3.6 mm.

(Comparative Example 2)
FIG. 4 is a diagram showing an SEM photograph of silver powder in Comparative Example 2 of Embodiment 1 of the present invention.
The silver powder of Comparative Example 2 shown in FIG. 4 is composed of aggregated particles having a sphere equivalent diameter of 20 μm to 85 μm. The silver powder of Comparative Example 2 has a sphere equivalent diameter of 53 μm with a cumulative weight of aggregated particles of 50%. The silver powder of Comparative Example 2 has an average particle size of 26 μm when dispersed with a 40 W homogenizer. The silver powder of Comparative Example 2 has 3.1% by weight of particles having an aspect ratio of more than 2.5 and 5.0 or less. Using this silver powder, a molded body having a diameter of 25 mm was prepared, sintered, and an electrode having a silver chloride film formed on the surface thereof was prepared. The thickness of this electrode was 3.2 mm.

(Comparative Example 3)
FIG. 5 is a diagram showing an SEM photograph of silver powder in Comparative Example 3 of Embodiment 1 of the present invention.
The silver powder of Comparative Example 3 shown in FIG. 5 is composed of aggregated particles having a sphere equivalent diameter of 10 μm to 95 μm. The silver powder of Comparative Example 3 has a spherical equivalent diameter of 53 μm with a cumulative weight of 50% of the aggregated particles. The silver powder of Comparative Example 3 has an average particle size of single particles of 6.9 μm when dispersed with a 40 W homogenizer. The silver powder of Comparative Example 3 has 0.5% by weight of particles having an aspect ratio of more than 2.5 and 5.0 or less. Using this silver powder, a molded body having a diameter of 25 mm was prepared, sintered, and an electrode having a silver chloride film formed on the surface thereof was prepared. The thickness of this electrode was 3.3 mm.

FIG. 6 is a diagram showing the characteristics of the silver-silver chloride electrode in Examples 1 and 2 and Comparative Examples 1 to 3 of Embodiment 1 of the present invention.
In actual use in seawater, it is desirable that the stabilization time is 30 minutes or less and the offset potential between the silver-silver chloride electrodes is low. The stability of the offset potential depends on the method for producing the silver chloride film. The stabilization time depends on the thickness of the sintered body of the silver powder, the shape of the particles composing the silver powder, and the average particle diameter. This is clear from FIG.

  As shown in FIG. 6, in the silver-silver chloride electrodes of Examples 1 and 2, the stabilization time from reaching the stable state after being put into seawater could be 30 minutes or less. The silver-silver chloride electrodes according to Examples 1 and 2 have been confirmed to exhibit stable characteristics in a one-year actual sea level test.

On the other hand, the silver-silver chloride electrode of Comparative Example 1 had a long stabilization time while using the same silver powder as in Example 1. This is because the thickness of the silver powder sintered body was larger than 3 mm.
Moreover, in the silver-silver chloride electrodes of Comparative Examples 2 and 3, the stabilization time was longer than that of the silver-silver chloride electrode of Comparative Example 1. The silver-silver chloride electrodes of Comparative Examples 1 to 3 each have a high bulk density of a sintered silver powder and a low open porosity.
The silver-silver chloride electrodes of Comparative Examples 2 and 3 were all difficult to mold, and both had to increase the pressure during molding. As a result, the open porosity was small and the average pore diameter was small.
The reason why it was difficult to form the silver-silver chloride electrodes of Comparative Examples 2 and 3 is considered to be due to the shape, particle diameter, and particle size distribution of the silver powder.
The raw material silver powder of the silver-silver chloride electrode of Comparative Example 2 had a small proportion of aggregated particles having a large aspect ratio and a small sphere-equivalent maximum particle size. Moreover, the raw material silver powder of the silver-silver chloride electrode of Comparative Example 3 had almost no aggregated particles having a large aspect ratio, and the average diameter of single particles was small.

Embodiment 2. FIG.
The second embodiment will be described below. In the second embodiment, the description will mainly focus on differences from the first embodiment.
The silver-silver chloride electrode manufacturing method uses silver powder having the same composition as in the first embodiment. The method for producing a silver-silver chloride electrode includes a forming step, a sintering step, and a surface chlorination step, as in the first embodiment shown in FIG.

FIG. 7 is an explanatory view showing a cross section of the structure of the silver-silver chloride electrode 100 according to Embodiment 2 of the present invention.
As shown in FIG. 7, the silver-silver chloride electrode 100 manufactured in the second embodiment includes a silver-silver chloride electrode portion 1 composed of a sintered body of silver powder whose surface is chlorinated, and a silver- A base material 2 that supports the silver chloride electrode portion 1 and a thin round bar 3 of the same material that is integrally processed, screwed, or silver brazed with the base material 2 are provided.

(Molding process)
In the molding step, a compact of silver powder having the above composition is compression molded. Further, in the molding step, a silver wire whose tip is chemically treated is inserted into a molded body of silver powder and molded integrally. In the molding step, a silver powder compact is formed on the substrate. Moreover, the thickness of the molded object of the silver powder formed on a base material at a formation process shall be 0.3 mm or more and 1.0 mm or less.
Instead of a silver wire having a chemically treated tip, strip-shaped silver having a chemically treated tip may be inserted into a molded body of silver powder and molded integrally.

The case where a metal plate with a small ionization tendency in silver or seawater having electrical characteristics close to this is used as the base material of the silver-silver chloride electrode will be described.
Specifically, a predetermined shape of a metal plate such as silver, gold, or platinum serving as the base material of the silver-silver chloride electrode is boiled and washed with alcohol such as methyl alcohol or ethyl alcohol. Next, one side of the metal plate is coated with a resin, and immersed in a 5 to 20% by weight nitric acid aqueous solution at 50 to 70 ° C. for about 3 minutes.
This metal plate is washed with pure water, and after removing the resin coating layer, it is further annealed in an electric furnace at 450 to 600 ° C. for 5 minutes.
Using a metal mold, a silver powder having the above composition is formed on the chemically treated surface of the metal plate at a molding pressure of 1.5 MPa or less, and the thickness of the silver powder compact is from 0.3 mm to 1.0 mm. Integrated molding process. Thereby, the molded object of the silver powder formed on the base material is obtained.

Further, the case where a ceramic plate to which porous or silver powder having the above composition easily adheres is used as the base material of the silver-silver chloride electrode will be described.
Specifically, a ceramic material such as cordierite, alumina, or magnesia, which is a base material for the silver-silver chloride electrode, is used as the base material for the silver-silver chloride electrode. In this case, in the case of a dense ceramic material, it is desirable that the surface roughness is 20 μm or more, and it is desirable to perform sandblasting or the like on one side as necessary.
The ceramic substrate is washed with pure water to remove inorganic deposits on the surface. At this time, an ultrasonic cleaner can also be used.
Next, the substrate of the ceramic material is boiled and washed with alcohol such as methyl alcohol or ethyl alcohol.

When a ceramic material is used as a base material, a strip-shaped silver plate having a thickness of 0.3 mm is prepared as a material for attaching a lead wire.
This silver plate is boiled and washed with alcohol such as methyl alcohol or ethyl alcohol.
Next, the silver plate is immersed in a 5 to 20 wt% nitric acid aqueous solution at 50 to 70 ° C. for about 3 minutes. Further, the silver plate is washed with pure water and annealed in an electric furnace at 450 to 600 ° C. for 5 minutes.
Using a mold, a ceramic material made of silver powder having the above composition on a surface having a surface roughness of 20 μm or more and a strip-shaped silver plate chemically treated with a molding pressure of 1.5 MPa or less Then, the thickness of the silver powder compact is integrally molded to 0.3 mm or more and 1.0 mm or less. Thereby, the molded object of the silver powder formed on the base material is obtained.

(Sintering process)
In the sintering process, the silver powder compact is sintered.

  Specifically, the silver powder compact is sintered in an electric furnace at 450 to 600 ° C. for 15 minutes.

(Surface chlorination process)
In the surface chlorination step, the surface of the sintered silver powder sintered body is chlorinated.

  When using a metal plate for the substrate, after attaching the lead wire to the side from which the resin coating layer has been removed, it is coated again with the resin, and the silver powder is baked in about 3.5% by weight aqueous sodium chloride solution. The aggregate is placed on the anode and the silver electrode is placed on the cathode, and a direct current of 5 to 20 mA is applied for about 24 hours to form a silver chloride film on the surface of the sintered body of silver powder. Thereby, the surface of the sintered body of silver powder is chlorinated.

  On the other hand, when a ceramic material is used as the base material, a lead wire is attached to a strip-shaped silver plate, and then a sintered body of this silver powder is placed on the anode in a 3.5% by weight sodium chloride aqueous solution. At the same time, a silver electrode is placed on the cathode, and a direct current of 5 to 20 mA is applied for about 24 hours to form a silver chloride film on the surface of the sintered body of silver powder. Thereby, the surface of the sintered body of silver powder is chlorinated.

(Function, effect)
In the method for producing a silver-silver chloride electrode according to the second embodiment, the silver-silver chloride electrode has a thickness of a compact of silver powder of 0.3 mm to 1.0 mm. In this case, a molded body of silver powder is formed on a metal substrate such as silver, gold, platinum, or a porous substrate, and this is chlorinated to form a silver-silver chloride electrode. Alternatively, a formed body of silver powder is formed on a base material of a ceramic material such as cordierite, alumina, or magnesia or a porous base material, and this is chlorinated to form a silver-silver chloride electrode.
Here, when the thickness of the compact of the silver powder is less than 0.3 mm, the surface area becomes small, so that the sensitivity as an electrode is lowered. On the other hand, if the thickness of the silver powder molded body is greater than 1.0 mm, the stabilization time until the potential difference between the pair of electrodes is stabilized becomes longer due to the influence of the penetration rate of seawater.

In the case where a conventional silver powder and silver chloride powder are applied in a paste form on a substrate and sintered, the melting point of silver chloride is 449 ° C. For this reason, it must be sintered at a temperature of 449 ° C. or lower. In this case, the sintering strength was low, and the bond with the substrate and the bond strength between the particles were small. Moreover, when a small particle diameter is used, it is difficult to form a porous sintered body having a large specific surface area. Therefore, it has been necessary to take a procedure such as using a mixture of silver, silver chloride and boron oxide after pelletizing. These silver-silver chloride electrodes can measure the potential level of a living body due to the presence of inclusions, but are not suitable for measuring a very weak electric field strength below that level.
On the other hand, since the silver-silver chloride electrode produced by the method for producing a silver-silver chloride electrode according to Embodiment 2 can be sintered at a temperature exceeding 450 ° C., the bond with the substrate and the bond strength between the particles Can be raised.

In a conventional silver-silver chloride electrode, particularly for a living body, the measured potential is at the following level. For example, in the case of tea trees, the fluctuation is about 10 mV with or without solar radiation, and the fluctuation is about 30 mV with ammonium sulfate fertilization. In addition, in the squid experiment, it has been confirmed that the membrane potential changes to the positive side due to the temporary influx of sodium ions in the nerve cells, and the action potential is generated. Since this phenomenon is electrochemical, the relationship with the ion concentration is large, and the magnitude of the potential is several tens of mV or more. Therefore, if the DCO (Direct Current Offset voltage) is about 1 to 10 mV, it can be used sufficiently.
On the other hand, in the silver-silver chloride electrode manufactured by the method for manufacturing a silver-silver chloride electrode according to Embodiment 2, the DCO is 10 μV or less, and therefore the sensitivity can be increased to the background noise level in seawater.

A large silver-silver chloride electrode is installed in a container for holding the silver-silver chloride electrode in an aqueous chloride solution in order to maintain surface stability, and is porous to maintain contact with the outside world. Have ceramics. When not installed in seawater, it must have an airtight cap to prevent moisture from escaping from the container, and the salinity of the aqueous chloride solution must match that of seawater. Otherwise, there is a problem that the offset potential between the pair of electrodes cannot be lowered.
On the other hand, in the silver-silver chloride electrode produced by the method for producing a silver-silver chloride electrode according to Embodiment 2, the thickness can be reduced to 1.0 mm or less without reducing the strength of the silver-silver chloride electrode. The pores can be controlled to a length effective for measuring the electric field strength, and the time required for stabilizing the potential of the pair of electrodes can be shortened.

(Example 3)
The silver powder of Example 3 has the same composition as that of Embodiment 1. The silver powder of Example 3 is composed of aggregated particles having a sphere equivalent diameter of 30 μm to 140 μm. The silver powder of Example 3 has a spherical equivalent diameter of 89 μm with a cumulative weight of 50% of the aggregated particles. The silver powder of Example 3 has an average particle size of 26 μm when dispersed with a 40 W homogenizer. The silver powder of Example 3 has 7.8% by weight of aggregated particles having an aspect ratio of more than 2.5 and 5.0 or less. Using this silver powder, on a chemically treated surface of a silver plate having a thickness of 1.0 mm, a mold is compression-molded to a diameter of 25 mm and a thickness of 0.5 mm, and sintered to produce a silver chloride film on the surface. A silver-silver chloride electrode was prepared.

Example 4
A silver plate shown in Example 3 having a thickness of 1.0 mm and a 0.3 mm thick strip-shaped silver plate chemically processed on a cordierite-ceramics plate as a base material are compression molded, sintered, and silver chloride on the surface. An electrode that produced a film was prepared.

(Example 5)
A silver cord shown in Example 3 having a thickness of 1.0 mm and a chemically processed 0.3 mm thick strip-shaped silver plate are integrally compression-molded on a porous cordierite-ceramics plate as a substrate, sintered, An electrode having a silver chloride film formed on the surface was prepared.

(Example 6)
On the chemically treated surface of a silver plate having a thickness of 1.0 mm, 5.1 weight of aggregated particles having an average particle diameter almost equal to that of the silver powder shown in Example 3 and an aspect ratio of more than 2.5 and 5.0 or less. % Silver powder is used. Then, compression molding was performed to a diameter of 25 mm and a thickness of 0.5 mm using a mold, and sintering was performed to create an electrode having a silver chloride film formed on the surface.

(Comparative Example 4)
The silver powder of Comparative Example 4 is composed of aggregated particles having a sphere equivalent diameter of 10 μm to 95 μm. The silver powder of Comparative Example 4 has a sphere equivalent diameter of 53 μm with a cumulative weight of aggregated particles of 50%. The silver powder of Comparative Example 4 has an average particle size of single particles of 6.9 μm when dispersed with a 40 W homogenizer. The silver powder of Comparative Example 4 has 0.5% by weight of aggregated particles having an aspect ratio of more than 2.5 and 5.0 or less. Using this silver powder, a 1.0 mm thick silver powder and a chemically treated 0.3 mm thick silver strip are compression molded on a porous cordierite-ceramics plate, sintered, and chlorinated on the surface. An electrode on which a silver film was formed was prepared.

(Comparative Example 5)
The silver powder of Comparative Example 5 is composed of aggregated particles having a sphere equivalent diameter of 20 μm to 85 μm. The silver powder of Comparative Example 5 has a spherical equivalent diameter of 53 μm with a cumulative weight of 50% of the aggregated particles. The silver powder of Comparative Example 5 has an average particle diameter of 26 μm when dispersed with a 40 W homogenizer. The silver powder of Comparative Example 5 has 3.1% by weight of aggregated particles having an aspect ratio of more than 2.5 and 5.0 or less. Using this silver powder, one side of a 1.0 mm thick silver plate was chemically treated on a chemically treated surface, compression molded to a diameter of 25 mm and a thickness of 0.5 mm with a mold, sintered, and a silver chloride film on the surface The electrode which produced | generated was produced.

FIG. 8 is a diagram showing the characteristics of the silver-silver chloride electrode in Examples 3 to 6 and Comparative Examples 4 and 5 of Embodiment 1 of the present invention. FIG. 9 is a diagram showing the relationship between the thickness of the silver-silver chloride electrode and the stabilization time in Examples 3 to 6 and Comparative Examples 4 and 5 of Embodiment 2 of the present invention.
In actual use in seawater, it is desirable that the stabilization time is 30 minutes or less and the offset potential between the silver-silver chloride electrodes is low. The stability of the offset potential depends on the method for producing the silver chloride film. The stabilization time depends on the thickness of the sintered body of the silver powder, the shape of the particles composing the silver powder, and the average particle diameter. This is clear from FIG.

  As shown in FIGS. 8 and 9, in the silver-silver chloride electrodes of Examples 3 to 6, the stabilization time from reaching the stable state after being put into seawater could be 18 minutes or less. It has been confirmed that the silver-silver chloride electrodes according to Examples 3 to 6 show stable characteristics in a one-year actual sea level test.

  On the other hand, in Comparative Examples 4 and 5, it took 35 minutes or more for the electrode stabilization time.

As mentioned above, according to Embodiment 1, 2, the manufacturing method of a silver-silver chloride electrode includes the shaping | molding process which shape | molds the molded object of silver powder. The method for producing a silver-silver chloride electrode includes a sintering step of sintering a compact of silver powder. The method for producing a silver-silver chloride electrode includes a surface chlorination step of chlorinating the surface of a sintered body of sintered silver powder. In the method for producing a silver-silver chloride electrode, the silver powder is composed of aggregated particles having a sphere equivalent diameter of 30 μm to 150 μm. In the silver powder, the particle size of single particles constituting the aggregated particles is 1 μm or more and 50 μm or less. The silver powder has a spherical equivalent diameter of 70% to 100 μm with a cumulative weight of 50% of the aggregated particles. The silver powder contains 20% by weight or more and 50% by weight or less of aggregated particles having an aspect ratio exceeding 2.0 and 2.5 or less. The silver powder contains 5% by weight or more and 10% by weight or less of aggregated particles having an aspect ratio exceeding 2.5 and 5.0 or less. The silver-silver chloride electrode is made of silver powder having the above composition.
According to this configuration, no special mechanism is required for storage or maintenance, and when the surface is installed in seawater from a dried state, seawater quickly penetrates into the pores and is stable in a short time. A working silver-silver chloride electrode can be produced.
In addition, a silver chloride thin film layer can be formed deep inside the pores, and a silver-silver chloride electrode can be manufactured in which deterioration is suppressed even when the detection signal level is large.
Furthermore, it is possible to produce a silver-silver chloride electrode that is small in size and has a small interval between electrodes and higher sensitivity in measurement of electric field strength than a conventional electrode.

In the method for producing a silver-silver chloride electrode, a compact of silver powder is compression-molded in the molding step. In the method for producing a silver-silver chloride electrode, the thickness of the sintered body of silver powder is formed to be 2 mm or more and 3 mm or less in the sintering step.
According to this configuration, since the thickness of the sintered body of silver powder is formed to be 2 mm or more, when the compression molding is performed while incorporating a silver wire having a diameter of 1 mm as a lead wire, a reduction in the adhesive strength of the silver wire is suppressed. can do. Moreover, since the thickness of the sintered body of silver powder is formed to be 3 mm or less, the time to reach a stable state can be shortened regardless of the time for the penetration of seawater into the pores.

In the method for producing a silver-silver chloride electrode, in the molding step, a silver wire or strip-shaped silver whose tip is chemically treated is inserted into a molded body of silver powder and molded integrally.
According to this configuration, a silver wire or strip-shaped silver whose tip is chemically processed as a lead wire is inserted into a molded body of silver powder and molded as a single body, so that a silver-silver chloride electrode can be easily manufactured. Yes. Moreover, the coupling | bonding of the electrode of a silver-silver chloride electrode and a lead wire can be performed easily.

In the method for producing a silver-silver chloride electrode, a molded body of silver powder is formed on a substrate in the molding step.
According to this configuration, since the thickness can be reduced to 1.0 mm or less without reducing the strength of the silver-silver chloride electrode, the pore can be controlled to a length effective for measuring the electric field strength, and the pair of electrodes can be controlled. The time required for stabilizing the potential can be shortened.

In the method for producing a silver-silver chloride electrode, a metal plate having a small ionization tendency in silver or seawater having electrical characteristics close to this is used as a base material. In the method for producing a silver-silver chloride electrode, the thickness of the molded body of silver powder formed on the substrate in the molding step is set to 0.3 mm or more and 1.0 mm or less.
According to this configuration, it is easy to give a curvature by matching the shape of the base material with the shape of the attachment portion and to attach the lead wire to the silver-silver chloride electrode.

In the method for producing a silver-silver chloride electrode, a porous or ceramic plate to which silver powder easily adheres is used as a substrate. In the method for producing a silver-silver chloride electrode, the thickness of the molded body of silver powder formed on the substrate in the molding step is set to 0.3 mm or more and 1.0 mm or less.
According to this configuration, in the case of a porous base material, there is seawater permeation from the back surface. Therefore, when silver powder is attached to the cylindrical inner surface, the background noise of the electric field signal due to seawater disturbance is reduced. Reduced. In the case of a ceramic plate to which silver powder easily adheres, a large area electrode can be formed as a towed or stationary electrode by attaching silver powder to the cylindrical inner surface. A weak electric field signal can be measured.

  Each embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  1 Silver chloride electrode part, 2 base material, 3 round bar, 100 silver chloride electrode.

Claims (6)

A molding step of molding a molded body of silver powder;
A sintering step of sintering the compact of the silver powder;
A surface chlorination step of chlorinating the surface of the sintered silver powder sintered body;
A method for producing a silver-silver chloride electrode comprising
The silver powder is
It is composed of aggregated particles having a sphere equivalent diameter of 30 μm to 150 μm,
The particle size of single particles constituting the aggregated particles is 1 μm or more and 50 μm or less,
A spherical equivalent diameter of 50% of the cumulative weight of the aggregated particles is 70 μm or more and 100 μm or less,
20% by weight or more and 50% by weight or less of the aggregated particles having an aspect ratio of more than 2.0 and 2.5 or less, and 5% by weight or more of the aggregated particles having an aspect ratio of more than 2.5 and 5.0 or less A method for producing a silver-silver chloride electrode having a composition containing 10% by weight or less. In the molding step, the molded body of the silver powder is compression molded,
2. The method for producing a silver-silver chloride electrode according to claim 1, wherein in the sintering step, a thickness of the sintered body of the silver powder is formed to be 2 mm or more and 3 mm or less.   3. The silver-silver chloride electrode according to claim 1, wherein in the molding step, silver wire or strip-shaped silver whose tip is chemically treated is inserted into the molded body of the silver powder and molded integrally. Production method.   The method for producing a silver-silver chloride electrode according to claim 1, wherein in the molding step, the molded body of the silver powder is formed on a base material. As the base material, using a metal plate having a small ionization tendency in seawater having silver or electrical characteristics close thereto,
The manufacturing method of the silver-silver chloride electrode of Claim 4 which sets the thickness of the said molded object of the said silver powder formed on the said base material at the said formation process to 0.3 mm or more and 1.0 mm or less. As the base material, a porous or ceramic plate to which the silver powder easily adheres,
The manufacturing method of the silver-silver chloride electrode of Claim 4 which sets the thickness of the said molded object of the said silver powder formed on the said base material at the said formation process to 0.3 mm or more and 1.0 mm or less.

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