JP3770626B2 - Manufacturing method of electrical contact material - Google Patents

Description

【００１３】
【表２】

【００１４】
表１の接点開閉条件は接触力30ｇ、開離力20ｇ、開閉１回／秒、電圧ＡＣ１00Ｖである。表１の寿命は突入電流１00Ａ、定常電流５Ａ負荷、溶着率は突入電流１00Ａ、定常電流５Ａ負荷、開閉1000回である。
【００１５】
表２の接点開閉条件は接触力30ｇ、開離力20ｇ、開閉１回／秒、電圧ＤＣ24Ｖである。表２の寿命は突入電流１00Ａ、定常電流５Ａ負荷、溶着率は突入電流１00Ａ、定常電流５Ａ負荷、開閉1000回である。
【００１６】
表１の結果から明白なように、本発明にかかる接点材料は全ての接点特性に対して交流・直流共に比較例の銀・酸化カドミウム接点よりも優れていた。また、製造工程も本発明のものは内部酸化を要しないので簡易であり、毒性もなかった。
【００１７】
【発明の効果】
以上のとおり、本発明にかかる接点材料は各種接点特性に優れるとともに、製造工程も簡易化され、さらに毒性もなく、実用上極めて優れた発明である。[0001]
[Industrial application fields]
The present invention relates to a method for producing an electrical contact material that is excellent in various contact characteristics and has a simple production process.
[0002]
[Prior art]
As an electrical contact material, a material produced by internally oxidizing nickel, tin, and silver alloy powder has been known (see Japanese Patent Publication No. 60-56774). Furthermore, a contact material made of a silver-cadmium oxide alloy is also known.
[0003]
[Problems to be solved by the invention]
However, the former electrical contact material requires a process of internal oxidation during manufacture, which makes the manufacturing process troublesome and inferior in contact characteristics. Furthermore, the latter electrical contact material has the disadvantage of being highly toxic.
[0004]
Accordingly, an object of the present invention is to provide a method for producing an electrical contact material which is excellent in various contact characteristics, simplified in the production process, has no toxicity, and has improved the disadvantages existing in the known art.
[0005]
[Means for solving problems]
In order to achieve the above object, according to the present invention, the silver ions are reduced with a reducing agent while the zinc oxide particles and the tin oxide particles are separated into an aqueous solution containing silver dichlorodiamine as silver ions. Each of the particles is uniformly dispersed as an independent powder in a silver matrix.
[0006]
Hydrazine is mainly used as a reducing agent that reduces silver ions.
[0007]
[Action]
The present invention is characterized in that zinc oxide and tin oxide are each dispersed as independent grains in a silver matrix. The present invention having such a configuration is excellent in various contact characteristics, that is, has a long life and exhibits excellent contact resistance. Also, the manufacturing process is simple because it does not require internal oxidation.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail by way of examples.
Example 1
In 1000 ml of pure water, 5 g of zinc oxide granules pulverized in a mortar, 0.1 g of tin oxide granules, and 94.9 ml of 100 g / l dichlorodiamine silver solution were added and mixed.
While maintaining the obtained mixed liquid at 30 ° C. and stirring to disperse the particles in the liquid, 50 ml of 10% hydrazine as a reducing agent was gradually added to the mixed liquid to reduce silver ions. The resulting precipitate was filtered, washed and dried to obtain a powder of 94.9% silver, 5% zinc oxide and 0.1% tin oxide (all by weight).
[0009]
Example 2
In the same manner as in Example 1, a powder of 92.7% silver, 7% zinc oxide, and 0.3% tin oxide (all by weight) was obtained.
[0010]
Each of the powders obtained in Examples 1 and 2 was loaded into a 10 mm diameter inner cylinder mold and molded at a pressure of 5 t / cm ² . Next, these molded bodies were baked at 800 ° C. for 1 hour in a non-oxidizing atmosphere, for example, in nitrogen gas or argon gas. The obtained baked body was drawn into a wire and then riveted to produce a rivet material.
[0011]
Using the rivet material having a diameter of 4.0 mm thus obtained, a contact switching test was conducted. For comparison, a silver / cadmium oxide 13% contact was similarly tested. The results are shown in Tables 1 and 2.
[0012]
[Table 1]

[0013]
[Table 2]

[0014]
The contact opening / closing conditions in Table 1 are a contact force of 30 g, a separation force of 20 g, opening / closing once / second, and a voltage of AC100V. The lifetime in Table 1 is an inrush current of 100 A, a steady current of 5 A load, and the welding rate is an inrush current of 100 A, a steady current of 5 A load, and 1000 times of opening and closing.
[0015]
The contact opening / closing conditions in Table 2 are a contact force of 30 g, a separating force of 20 g, an opening / closing of once per second, and a voltage of 24 VDC. The life in Table 2 is an inrush current of 100 A, a steady current of 5 A load, and the welding rate is an inrush current of 100 A, a steady current of 5 A load, and 1000 times of opening and closing.
[0016]
As is apparent from the results in Table 1, the contact material according to the present invention was superior to the comparative silver / cadmium oxide contact in both AC and DC in all contact characteristics. Also, the production process of the present invention is simple and free of toxicity because it does not require internal oxidation.
[0017]
【The invention's effect】
As described above, the contact material according to the present invention has excellent various contact characteristics, simplifies the manufacturing process, has no toxicity, and is extremely excellent in practical use.

Claims (2)

While dispersing zinc oxide particles and tin oxide particles in an aqueous solution containing dichlorodiamine silver as silver ions, the silver ions are reduced with a reducing agent to uniformly distribute the particles as independent powders in a silver matrix. A method for producing an electrical contact material, characterized by being dispersed. The method for producing an electrical contact material according to claim 1, wherein the reducing agent is hydrazine.