JP3089428B2 - Method for producing insulating high magnetic permeability alloy - Google Patents

Description

The present invention relates to a method for producing an insulated high-permeability alloy when a high-permeability alloy is used as an iron core of a transformer or the like with high-frequency alternating current.

(Prior art) When high permeability alloys are used as high frequency alternating current as iron cores for transformers, etc., it is necessary to make the alloy thin and to insulate the layers between them in order to reduce eddy current loss and prevent reduction in effective permeability. There is.

As an insulating method for high permeability alloys, for example, an MgO film is formed on an alloy plate by brush painting or electrophoresis, and then annealed in a hydrogen stream to give high permeability, and then interlayer insulation using lacquer or the like Is applied. If the core is to be wound directly after annealing as in the case of a wound core, use MgO to prevent adhesion during annealing.
Although the film also serves as interlayer insulation of the iron core, in the case of a punched iron core in which iron cores are weighted after annealing, an organic insulator is applied or oxidized.

(Problems to be Solved by the Invention) In these conventional methods, when an MgO film is formed by brush painting or electrophoresis, or when an organic insulator is applied, the applied film is thick (thus, an extremely thin coated film is required). It is difficult to realize, so the space factor of the iron core is poor).

Further, even if a high magnetic permeability alloy is subjected to oxide insulation, if the magnetic permeability is extremely high, the magnetic permeability deteriorates due to oxidative strain, and there is a drawback that the use is limited.

Therefore, a technical problem of the present invention is to provide a method for manufacturing a high-permeability alloy having a thin oxide film that can be used as an insulating material by a simple method.

(Means for Solving the Problems) The present inventor has reported that the titanium oxide thin film obtained by electrolytic deposition of titanium is dense, has good adhesion, and has excellent heat resistance and insulation properties. Deemed very suitable for insulation.

Furthermore, titanium is difficult to electrodeposit in an aqueous solution electrolysis method using an aqueous solution as a solvent, and good results have not been obtained. Therefore, the present inventor has proposed that titanium is prepared by an organic electroplating method using an organic solvent as a solvent for the plating solution. An insulating method of a high magnetic permeability alloy using titanium oxide obtained by an electrolytic deposition method is considered.

According to the present invention, there is provided an insulating method characterized by forming a titanium oxide film on a substrate made of a high magnetic permeability alloy from a plating solution containing a titanium metal salt and an organic solvent for solubilizing the same by an electrolytic deposition method. And a method for producing a conductive high magnetic permeability alloy.

Here, as the titanium metal salt used in the present invention, salts such as TiCl ₃ , TiCl ₄ , K ₂ TiF ₆ and (NH ₄ ) ₂ TiF ₆ can be used.

However, in general, when a metal is deposited from a non-aqueous solvent-based plating bath, it is not preferable to mix water, and titanium has a high degree of d-orbital electron deficiency due to its electron configuration. It easily bonds to oxyanine, and it is difficult to remove this oxygen electron from the d orbit.
Therefore, it is preferable to perform electrolysis in a state where oxygen is completely removed from the electrolytic bath, and therefore, it is preferable to use an anhydrous compound as the titanium metal salt. The above titanium metal salt can be used because it is relatively easy to obtain its anhydride.

In the present invention, an organic solvent having a high dielectric constant is preferably used as the organic solvent for dissolving the titanium metal salt. The reason why the use of a solvent having a high dielectric constant of an organic solvent is suitable is that 1) the solubility of various metal salts of titanium is high and 2) electrolysis at a high current density is possible.

In addition, titanium oxide obtained by such an electrolytic deposition method of titanium can easily become titanium oxide in room temperature air because the titanium to be electrolytically deposited is very fine.
Furthermore, it is possible to improve the adhesion by heating at a high temperature.

By using such a plating method of the present invention, titanium which could not be electrolytically plated in an aqueous solution can be easily deposited by a plating method, and the titanium oxide obtained by the electrolytic deposition method can be deposited on the surface of a high permeability alloy. By obtaining, it is possible to insulate a high magnetic permeability alloy.

(Example) Hereinafter, an example of the present invention will be described.

TiCl ₃ , TiCl ₄ , K ₂ TiF ₆ , (NH ₄ ) ₂ TiF as titanium metal salt
_In each case, an anhydride was used, and formamide, acetamide, and dimethylformamide were purified by distillation under reduced pressure under nitrogen as an organic solvent.

These compounds are mixed in predetermined amounts as shown in Table 1,
A plating bath was used. In addition, a closed type electrolytic vessel was used.

A platinum plate was used for the anode, and Mo permalloy and 50% Ni with strong magnetic anisotropy were selected for the cathode. The Mo permalloy was cleaned after punching, subjected to electrolytic deposition of titanium in the electrolyte described in Table 1, dried at room temperature to form a titanium oxide thin film, and then subjected to magnetic annealing in hydrogen at 1050 ° C. for 3 hours. . 50% Ni permalloy was formed into a wound iron core after forming a titanium oxide thin film, annealed at 1050 ° C in hydrogen, and the wound copper wire was applied as it was.

Table 2 shows the value of the inductance at each frequency. In the table, column 54, "54 sheet inductance" is the result of interlayer insulation applied by spray coating with black lacquer after annealing, the space factor is poor, and only 54 sheets can be stacked. Was. For comparison, the inductance value converted to the value when 61 sheets are stacked is shown as “61 sheet converted inductance” in the fourth column. From the table, no difference in magnetic permeability was recognized in the practically punched iron core, and the titanium oxide insulated core had a higher space factor, and thus a higher inductance could be obtained.

(Effects of the Invention) As described above, according to the present invention, insulation with a titanium oxide film obtained by electrolytic deposition of titanium can produce a thin insulating thin film as compared with the conventional insulation method.
It is possible to provide a method for producing a high magnetic permeability alloy that can improve the space factor and simplify the method of forming a film.

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Claims (1)

(57) [Claims] 1. An insulating material, comprising: forming a titanium oxide film on a substrate made of a high magnetic permeability alloy from a plating solution containing a titanium metal salt and an organic solvent for solubilizing the same by an electrolytic deposition method. Manufacturing method of high permeability alloy.