JPH05247695A - Electrode for surface treatment - Google Patents

Abstract

PURPOSE:To provide the electrode for a surface treatment which can prevent the corrosion at the end of an electrode body and can be reduced in size and cost in an electrochemical treatment using an electrolyte for metal plating, resin electrodeposition, etc., as a medium. CONSTITUTION:A blind cylindrical member 6 having the corrosion resistance higher than the corrosion resistance of the electrode body 1 is fitted to the end of the electrode body 1 having a copper core material 3 having an electrical conductivity, an outer layer 2a of platinum consisting of a material having the higher corrosion resistance than the corrosion resistance of this copper core material 3 and an intermediate layer 2b of niobium. The above-mentioned electrode is constituted by fitting a cylindrical member 5 onto this blind cylindrical member 6. This cylindrical member 5 extends by a length L to the base end side of the electrode body 1 from the blind cylindrical member 6. This length L is set at >=5 times the spacing (t) between the inside surface of the magnetic cylindrical members 5 and the electrode body 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode for surface treatment used for electrochemical treatment using an electrolytic solution such as metal plating and resin electrodeposition as a medium.

[0002]

2. Description of the Related Art Lead electrodes and stainless steel electrodes are used as electrode materials used for surface treatment such as metal plating and resin electrodeposition. However, since such an electrode material has a drawback that it is often lost during use of an electric current, there is an increasing demand for an electrode with little loss from the viewpoint of operation stability of surface treatment and improvement of the quality of the treated material. Therefore, noble metals and intermetallic compounds, which are less lost and have excellent corrosion resistance, have already been used as electrode materials. Since such an electrode material with little loss is expensive and inferior in workability, it is not used alone, but a corrosion resistant material such as titanium is placed on the core material and the electrode function is provided on the surface of the core material. It is used as a composite structure electrode in the state where the material is coated. In this case, the electrode material whose core material is made of titanium is applied to the short material because titanium has a high electric resistance, and for the long material, a material such as copper having excellent electrical conductivity should be placed on the core material. Is proposed.

In the composite structure electrode in which the surface of the core material is coated with the above-mentioned electrode functional material, the electrode core material is exposed at the end portion, so that the end portion is corroded by the electrolyte solution. There is a problem that it is easy. Therefore, it is proposed to bend the electrode, immerse the bent portion in the electrolyte solution, and take the end of the electrode out of the electrolyte solution so that the electrode core material at the end does not come into contact with the electrolyte solution. It has been (Japanese Patent Application No. 2-243268).

[0004]

However, in the case of bending the electrode in this way, the electrode needs to be bent at least once, which increases the processing cost of the electrode. Further, in order to take out the electrode end portion to the outside of the electrolyte solution, the electrode needs an extra length only for that portion.
In addition, there are inconveniences such as structural restrictions in electrode design.

The present invention has been made in view of the above problems, and provides an electrode having a composite structure which is excellent in operation stability and surface treatment quality in surface treatment such as metal plating and electrodeposition of resin. An object of the present invention is to provide a surface treatment electrode having a highly reliable electrode end portion and an end portion structure capable of suppressing the wear of the electrode functional material at the electrode end portion.

[0006]

SUMMARY OF THE INVENTION An electrode for surface treatment according to the present invention comprises an electrode body having an electrically conductive core material and an outer layer made of a material having a corrosion resistance superior to that of the core material, and an electrode body of the electrode body. A bottomed cylindrical member made of a material that is fitted to the end portion and has a higher corrosion resistance than the core material; and a cylindrical member that is fitted to the bottomed cylindrical member and has a higher corrosion resistance than the core material, This cylindrical member extends to the base end side of the electrode main body by a length L from the bottomed cylindrical member, and the length L is 5 times the distance t between the inner surface of the cylindrical member and the electrode main body. It is characterized by being set as described above.

[0007]

Since the bottomed cylindrical member made of a material having better corrosion resistance than the core material of the electrode body is fitted to the end portion of the electrode body, the core material is prevented from being exposed at the end portion of the electrode body. Corrosion of the electrode body by the corrosive electrolyte solution is prevented.

Further, a cylindrical member made of a material having excellent corrosion resistance is externally fitted to the bottomed cylindrical member, and the length of the cylindrical member is a length L closer to the base end side of the electrode body than the bottomed cylindrical member. It has been extended. Since this length L is set to be 5 times or more the distance t between the inner surface of the cylindrical member and the electrode body, the discontinuity in the current density at the boundary between the electrode body and the bottomed cylindrical member is alleviated. As a result, it is possible to suppress the wear of the electrode functional material that occurs at the boundary between the electrode body and the bottomed cylindrical member.

[0009]

Embodiments of the present invention will now be specifically described with reference to the accompanying drawings. FIG. 1 is a vertical sectional view of an electrode end portion according to an embodiment of the present invention. The electrode body 1 is, for example, a composite structure electrode formed of a platinum outer layer 2a, a niobium intermediate layer 2b, and a copper core material 3 in order from the surface. The outer diameter of the electrode body 1 is, for example, 10 mm. The breakdown is, for example, that the platinum outer layer 2a has a thickness of 2 μm, the niobium intermediate layer 2b has a thickness of 100 μm, and the balance is made of the copper core material 3. .. A bottomed cylindrical member 6 is fitted to the end of the electrode body 1. The bottomed cylindrical member 6 is formed of a material having a higher corrosion resistance than the copper core material 3 of the electrode body 1, such as vinyl chloride. In this case, the bottomed cylindrical member 6 is previously coated with the epoxy resin adhesive 7 and fitted into the electrode body 1, and the end portion of the electrode body 1 is covered with the bottomed cylindrical member 6, By solidifying the epoxy resin adhesive 7, the epoxy resin adhesive 7 is embedded in the contact boundary portion between the bottomed cylindrical member 6 and the electrode body 1. As a result, the gap with the electrode body 1 is eliminated, and the invasion of the electrolyte solution is prevented.

Further, the cylindrical member 5 is fitted on the bottomed cylindrical member 6 and both are fixed by an epoxy resin adhesive 7. In this case, the cylindrical member 5 extends to the base end side of the electrode body 1 by a length L from the bottomed cylindrical member 6, and this length L
Is set to be 5 times or more the distance t between the inner surface of the cylindrical member 5 and the electrode body 1, and the extending portion of the cylindrical member 5 forms the current interruption space 4. The cylindrical member 5 has an inner diameter of 13 mm, for example.
Made of vinyl chloride, the length L of the non-contact part with the composite structure electrode
Has a cylindrical shape of 8 mm.

In the surface treatment electrode thus constructed, the bottomed cylindrical member 6 made of a material having a higher corrosion resistance than the copper core material 3 of the electrode body 1 is bonded to the end portion of the electrode body 1 by epoxy resin. Since the agent 7 is applied and fitted, it is possible to prevent the copper core material 3 from being exposed at the end of the electrode body 1 and prevent the electrode body 1 from being corroded by the corrosive electrolyte solution.

Further, a cylindrical member 5 made of a material having excellent corrosion resistance is externally fitted to the bottomed cylindrical member 6, and this cylindrical member 5 is closer to the base end side of the electrode body 1 than the bottomed cylindrical member 6. The length L of the cylindrical member 5.
Since the distance t between the inner surface of the electrode body and the electrode body 1 is set to 5 times or more, the discontinuity of the current density at the boundary between the electrode body 1 and the bottomed cylindrical member 6 is alleviated, and the electrode body 1 and It is possible to suppress wear of the electrode functional material that occurs at the boundary with the bottom cylindrical member 6.

The surface treatment electrode according to the above-mentioned embodiment is actually manufactured, and the end portion of the electrode is subjected to, for example, a coating temperature of 40 ° C. to 45 ° C.
As a result of soaking in the above cationic electrodeposition coating composition for 6 months, no change with time was observed and it was sufficiently durable for practical use.

Further, the insulating cylindrical member 5 cuts off the electric current in a non-contact state so that the bottomed cylindrical member 6 and the electrode body 1
The discontinuity in the current density at the boundary with is relaxed. As a result, it was possible to suppress the wear of the electrode functional material at the boundary portion.

On the other hand, FIG. 2 is a vertical sectional view of an electrode end portion of a comparative example. On the outer periphery of the steel core material 13 and the niobium intermediate layer 12b,
The outer layer 12a made of niobium and nickel alloy is coated as an electrode functional material. When only the bottomed cylindrical member 14 similar to that in the above embodiment is attached to the end portion of the electrode body 11 with the epoxy resin adhesive material 15, when electricity is used, an electrode is generated at the boundary between the bottomed cylindrical member 14 and the electrode body 11. Significant wear of the functional material occurred, and the wear tended to spread to the electrode body side with use.

Next, the results of testing the characteristics of the current interruption space by changing the length L of the non-contact portion of the surface treatment electrode according to the embodiment of the present invention are compared with the comparative example outside the scope of the claims of the present application. And explain.

Table 1 shows the test results of Example 1 and Comparative Examples 1 to 3. 22 mm inner diameter for a composite structure electrode with an outer diameter of 20 mm
The cylindrical member 5 of mm is used as the current interrupting material. Further, the electrode body 1 is made of an intermetallic compound, niobium and steel, and the electrolyte solution uses the above-mentioned cationic electrodeposition coating,
A comparative test was conducted by changing the length L of the non-contact portion of the current interruption space. As is clear from Table 1, Comparative Examples 1, 2, and 3
In comparison with Example 1, the time taken for the electrode functional material to melt and the niobium to be exposed is shorter. Therefore, in the case of the example, the time until the electrode functional material is melted is extremely long.

[0018]

[Table 1]

[0019]

As described above, in the surface treatment electrode according to the present invention, the contact of the electrode end portion with the electrolyte solution is avoided and the wear of the electrode functional material is also prevented. The reliability of the edges is significantly improved.

As a result, there is no need to bend the surface treatment electrode to take out the electrode end portion to the outside of the electrolyte solution, and in the state where the end portion of the surface treatment electrode is immersed in the electrolyte solution using a straight-drawn material. Can be used. Therefore, the present invention can miniaturize the electrode for surface treatment, reduce the manufacturing cost, and make a great contribution to the field of electrochemical treatment using an electrolytic solution such as metal plating and resin electrodeposition as a medium. is there.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing an end portion of a surface treatment electrode according to an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view showing an end portion of a surface treatment electrode of a comparative example.

[Explanation of symbols]

 1, 11; electrode body (composite structure electrode) 2a, platinum outer layer (electrode functional material) 2b, 12b; niobium intermediate layer 3; copper core material 4; current interruption space 5; cylindrical member 6, 14; bottomed cylindrical member 7 , 15; Epoxy resin adhesive 12a; Niobium and nickel outer layer (electrode functional material) 13; Steel core material

Claims (1)

[Claims] 1. An electrode body provided with a conductive core material and an outer layer made of a material having a corrosion resistance superior to that of the core material, and a corrosion resistance superior to that of the core material fitted to an end portion of the electrode body. A cylindrical member having a bottom and a cylindrical member fitted to the cylindrical member having a better corrosion resistance than the core material, the cylindrical member having the electrode body more than the cylindrical member having a bottom. For the surface treatment, which is extended to the base end side by a length L, and the length L is set to be 5 times or more the distance t between the inner surface of the cylindrical member and the electrode body. electrode.