JPH11238611A - Process for rust prevention of rare earth permanent magnet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain in a simple step proper magnetic characteristics at low cost by a method, wherein rare earth permanent magnet raw material after the surface processing is contained in a vessel to coat the surface of the rare earth permanent magnet with a resin rust preventive point by having the vessel rotate. SOLUTION: Numerous raw materials 2 (Nd magnetic raw material) of Nd- Fe-B sintered magnet are cut out of sintered alloy blank material of Nd-Fe-B magnet. Next, the edge parts formed on the angle parts of the Nd magnet raw material 2 is chamfered. Next, the surface of the the Nd magnet is surface- processed by wet blasting process for roughening into irregular mode. Subsequently, the Nd magnet surface is immersed in a rust preventive agent as the preprocessing of the resin painting. Later, the surface of the Nd magnet raw material is coated with a rust preventive paint. Furthermore, as for a barrel device 31, a hollow barrel vessel 32 is used to be turned around an axle by a rotary drive mechanism.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for rust-preventing a rare-earth permanent magnet in which the surface of the rare-earth permanent magnet is coated with a resin.

[0002]

2. Description of the Related Art Permanent magnets are widely used in various fields. In recent years, rare earth permanent magnets have been used as high performance magnets. This rare earth permanent magnet has good magnetic properties, but since it easily generates rust, various techniques for performing rust prevention treatment on the surface have been conventionally proposed and put into practical use.

[0003] As such a conventional rust prevention treatment method,
Nickel plating, aluminum chromate, parylene coat,
In addition to those that have been provided with a corrosion-resistant coating such as polyimide,
As described in Japanese Patent Publication No. 8-4047 and the like, a resin coating is proposed.

[0004]

However, in the case of forming a corrosion-resistant coating such as nickel plating, there is a problem that the magnetic force tends to be short-circuited because the corrosion-resistant coating is made of a magnetic material, so that the magnetic properties are apt to deteriorate. is there. Further, the cost is high because expensive equipment is required. On the other hand, even when performing resin coating, productivity is not good because labor-intensive work is required.

Accordingly, an object of the present invention is to provide a method for rust-preventing rare-earth permanent magnets, which can produce rare-earth permanent magnets having good magnetic properties at a low cost with simple steps. I do.

[0006]

In order to achieve the above object, according to the first aspect of the present invention, a rare earth permanent magnet made of a predetermined resin material is coated on the surface of a rare earth permanent magnet. In the rust-prevention treatment method of the permanent magnet, a surface treatment step of roughening the surface of the rare earth permanent magnet material to make it rough, and a large number of rare earth permanent magnet materials after the surface treatment step are stored in a predetermined container, A barrel coating step of applying a resin rust preventive paint on the surface of the rare earth permanent magnet material while stirring the rare earth permanent magnet materials by rotating the container.

In the invention according to claim 2, the rare earth permanent magnet material according to claim 1 is made of a sintered magnet or a bonded magnet material represented by Fe-BR (R is a rare earth element). .

Further, in the invention according to claim 3, the surface treatment step according to claim 1 is performed by a wet blast method.

Further, in the invention according to the fourth aspect, in a stage prior to the barrel coating step according to the first aspect, a chamfer for processing an edge portion formed at a corner of each rare earth permanent magnet material into a curved surface. It has a processing step.

[0010] On the other hand, in the invention according to claim 5, the chamfering step according to claim 4 is performed by a roller barrel device which stores a large number of rare earth permanent magnet materials in a predetermined container and rotates the container. Like that.

Further, in the invention according to the sixth aspect, a rust preventive for improving adhesion is immersed in each rare earth permanent magnet material before the barrel coating step according to the first aspect while applying ultrasonic waves. Like that.

Further, in the invention according to claim 7, the barrel coating step according to claim 1 includes a base coating step and a top coating step, and in each of these steps, a resin rust preventive paint having a different component from each other is used. I have to.

[0013] According to the above-described means,
Rare earth permanent magnet material whose surface has been roughened by the surface treatment process is coated with resin rust preventive paint well, and a large amount of rare earth permanent magnet material is simultaneously and efficiently applied by the barrel coating process. It has become so.

Such an effect is particularly effective for a sintered magnet or a bonded magnet represented by Fe-BR (R is a rare earth element) as described in the second aspect.

According to the wet blasting method, the surface treatment step is performed efficiently.

Further, if the chamfering step is performed as in the means of claim 4, in the barrel coating step, the edge portion of each rare earth permanent magnet material is removed.
The resin rust-preventive paint is applied well without peeling off.

Further, such a chamfering step is
According to the fifth aspect of the present invention, when the processing is performed by the roller barrel device, a large number of rare earth permanent magnet materials can be efficiently treated.

On the other hand, if the rust preventive is immersed as a pre-treatment in the barrel coating step, the adhesion of the resin rust preventive paint in the barrel coating step is improved.

Further, if the barrel coating step is repeatedly performed using resin rust preventive paints of different components as in the means according to claim 7, the rust preventive paint can enhance the adhesion of the resin rust preventive paint. Becomes possible.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a rust-preventing process for a rare-earth permanent magnet according to an embodiment of the present invention will be described with reference to Fe-BR (R).
A rare-earth permanent magnet represented by a rare-earth element will be described by taking a sintered magnet using Nd (neodymium) as a rare-earth element as an example.

The whole process is as shown in FIG. 1. First, as shown in FIG. 2 (a), a sintered alloy of a Nd—Fe—B magnet formed into a block shape is used. As shown in FIG. 2B, a large number of thin plate-like Nd—Fe—B sintered magnet materials 2 (hereinafter simply referred to as Nd magnet materials) 2 are cut out from the blank material 1 by cutting. Step 1 of 1).

Next, for each of the thin Nd magnet materials 2 before magnetization prepared as described above, a roller barrel device 11 as shown in FIG.
The edge portion formed at the corner of the magnet material 2 is chamfered (step 2 in FIG. 1). Roller barrel device 11
Represents a large number of Nd magnet materials 2 as shown in FIG.
In a cylindrical container 12 for rotation, and a pair of rotary drive rollers 1 arranged substantially in parallel and horizontally.
The cylindrical container 12 is placed on the sides 3 and 13 in a horizontal direction. The cylindrical container 12 is placed in a state where its outer surface is in linear contact with the pair of rotary drive rollers 13, 13. At least one of the drive rollers 13 is driven to rotate to form a cylindrical shape. The container 12 is configured to rotate.

Inside the cylindrical container 12, a large number of N
Approximately the same number of media together with the d magnet material 2, for example, φ3 to
The ceramic balls 14 of φ10 mm are accommodated in a mixed manner, and the cylindrical container 12 is
For example, it is rotated at 60 rpm for 30 to 120 minutes. As a result, a large number of N accommodated in the cylindrical
Each of the d magnet materials 2 collides with each other, and FIG.
As shown in (1), the edges formed at the corners of the respective Nd magnet blanks 2 are gradually shaved into curved surfaces 3.

Next, the surface of the Nd magnet material 2 is subjected to a surface treatment by a wet blast method (Step 3 in FIG. 1). In this wet blast method, for example, a large number of Nd magnet materials 2 are housed in a cone-shaped barrel container 21 as shown in FIG. This is performed by rotating the barrel container 21 while discharging the medium (abrasive) 22 into the barrel container 21.

In the present embodiment, the rotation speed of the barrel container 21 is set at 5 to 10 rpm, and the air pressure at the air nozzle 23 is 0.5 to 2.0 k.
g / cm ² , and the processing time at this time is 1
It is set to 0 to 30 minutes. Also, the above McCorundum # 2
For example, the medium 22 such as 20 is prepared by diluting a rust-preventive oil such as SC600 (trade name of Yushilo Chemical Manufacturing Co., Ltd.) with water at a ratio of 1% by volume to water, and adding 10 to 20% by volume to a base oil. Mix and use in proportions.

By the surface treatment by the wet blast method, the surface of the Nd magnet material 2 is roughened into an uneven rough surface. At the same time, in the chamfering process by the roller barrel device 11 described above. The generated dust and the like are removed from the surface of the Nd magnet material 2.

In this case, a so-called drive last method can be adopted without using the wet blast method as in this embodiment. This drive last method
Only the abrasive is blown together with the compressed air from the air nozzle 23, and no rust-preventive oil or water is used.

Next, the surface of the Nd magnet material 2 is coated with a resin. As a pretreatment step, a rust preventive such as SC600 (trade name of Yushiro Chemical Manufacturing) or the like is dipped ( Step 4 in FIG. 1). This immersion is for improving the adhesion of the resin coating film, but a good immersion state can be obtained by performing the immersion while applying ultrasonic waves.

After such a pretreatment, a rust-preventive paint composed of a predetermined undercoat resin material is coated on the surface of the Nd magnet material 2 by using a barrel coating device 31 as shown in FIG. The undercoat is applied (step 5 in FIG. 1). As shown in FIG. 5, the barrel coating device 31 used for this undercoating includes a hollow barrel container 32 in the form of a substantially hexagonal column disposed horizontally, and the hollow barrel container 32
Are configured to be rotationally driven around an axis by a rotational drive mechanism (not shown).

In the hollow barrel container 32, a ventilation plate (not shown) made of a material through which hot air can pass, such as a wire mesh or a porous material, is provided to cover the inner wall surface of the hollow barrel container 32. The Nd magnet material 2 after the above-described surface treatment step is placed on the ventilation plate so as to be placed thereon. In the hollow barrel container 32, for example, 2000 to 500
Zero Nd magnet material 2 is stored as one lot,
The hollow barrel container 32 is rotationally driven at 50 rpm.

A coating liquid supply pipe 33 is disposed at an upper position inside the hollow barrel container 32 so as to extend therefrom, and a liquid discharge nozzle provided at a tip end of the coating liquid supply pipe 33. 34 is disposed so as to face the Nd magnet material 2 in the hollow barrel container 32 described above from above. The coating liquid supply pipe 33 is connected to a coating liquid storage tank (not shown) via a pressure pump. Then, by rotating the hollow barrel container 32 and stirring each Nd magnet material 2, an undercoating rust preventive paint made of a predetermined resin material is sprayed through the liquid discharge nozzle 34 to spray each Nd magnet material 2. An undercoat is applied by applying a resin rust preventive paint on the surface.

As the undercoat resin rust preventive paint, for example, a paint having a function of improving adhesion such as fastite (trade name of Ohashi Chemical Manufacturing Co., Ltd.) is used.
The liquid is supplied at 0 ml / min. By using such an undercoating resin rust preventive paint, the adherence of the paint to the surface of the Nd magnet material 2, particularly to the corners, is improved.

The hollow barrel container 32 is supplied with hot air heated to a predetermined temperature from a heating means (not shown), and the hot air passing through the Nd magnet material 2 is exhausted by an exhaust gas having an exhaust duct. It is configured to escape from the container out of the means. Hot air at this time is 1-3kg
/ Cm ² , the temperature is constantly monitored by the temperature detecting means, and the temperature is set and maintained at a predetermined temperature within a range from normal temperature to 100 ° C.

A large number of Nd magnet blanks 2 thus undercoated with a resin anticorrosive paint were set in a transfer device (not shown), and each Nd magnet blank 2 was aligned in a state of being separated from each other. In the state (Step 6 in FIG. 1), a curing process is performed in a vacuum atmosphere (Step 7 in FIG. 1).
Thereby, the undercoat resin rust preventive paint described above is cured.

Further, using the same barrel coating device 31 as described above, a rust-preventive paint made of a predetermined top-coating resin material is applied to the surface of the Nd magnet material 2 to perform top-coating (step 8 in FIG. 1). ). For example, OFRON F1SK2 (trade name of Ohashi Chemical Co., Ltd.) is used as the rust preventive paint for the top coat. Then, by this top coating barrel coating, as shown in FIG.
A 0 μm resin rust preventive paint is applied as a resin coat layer on the surface of the Nd magnet material 2 to obtain a rust-proof Nd magnet material 4.

After that, the Nd magnet blanks 4 on which the resin rust preventive paint has been applied in this manner are set again in a transfer device (not shown), and the respective Nd magnet blanks are arranged in a separated state. In this state (Step 9 in FIG. 1), a curing process is performed in a vacuum atmosphere (Step 10 in FIG. 1), whereby the above-mentioned rust-preventive paint is hardened to complete the rust-preventive process (FIG. 1). Step 1 of 1
1).

The Nd magnet material 4 completed by applying the resin rust-preventive paint is finally magnetized as required, and FIG.
Is attached to a predetermined device as a plate-like magnet 5 as shown in FIG.

In such an embodiment, the Nd magnet blank 2 whose surface has been roughened by the surface treatment step is coated with the resin rust preventive paint satisfactorily. The Nd magnet material 2 is simultaneously and efficiently coated. That is, with respect to the Nd magnet material 2 as a rare earth permanent magnet material represented by Fe—BR (R is a rare earth element) as in the present embodiment,
By performing the resin rust prevention treatment efficiently, productivity can be improved while obtaining good magnetic properties, which is particularly effective.

Further, if the surface treatment step by the wet blast method and the chamfering step by the roller barrel device 11 as in this embodiment are performed, each step can be performed more efficiently.

Further, if the chamfering step as in this embodiment is performed, in the barrel coating step, the peeling-off of the resin rust preventive paint applied to the corners of each Nd magnet material 2 is minimized. Furthermore, if a rust preventive is immersed as a pretreatment in the barrel coating process as in the present embodiment, the adhesion of the rust preventive paint in the barrel coating process is improved. In addition, if the barrel coating process is repeatedly performed using different rust-preventive paints as in the present embodiment, rust-preventive paint such as enhancing the adhesion of the rust-preventive paint becomes possible,
Good rust-proof coating film is obtained.

Although the embodiments of the present invention made by the inventor have been specifically described above, the present invention is not limited to the above-described embodiments, and can be variously modified without departing from the gist thereof. Needless to say. For example, in the above-described embodiment, a magnet employing Nd as a rare earth element is used, but the present invention can be similarly applied to a magnet having another rare earth element.

In the above-described embodiment, the barrel coating step is performed twice. However, the barrel coating step may be set to be performed only once or three or more times.

Further, although the above-described embodiment is directed to a sintered magnet, the present invention can be similarly applied to a rare-earth bonded magnet.

[0044]

As described above, according to the first aspect of the present invention, the surface is roughened by the surface treatment step, whereby the rare-earth permanent magnet material can be satisfactorily coated with the resin rust preventive paint. A large number of rare-earth permanent magnets with good magnetic properties can be manufactured in large quantities at a low cost by a simple process, since a large amount of rare-earth permanent magnet materials are simultaneously and efficiently coated by the barrel coating process. And the usefulness of the rare earth permanent magnet can be greatly improved.

That is, as in the second aspect of the present invention,
It is possible to efficiently perform a resin rust prevention treatment on a rare earth permanent magnet material represented by Fe-BR (R is a rare earth element).

Such an effect can be further enhanced by performing a surface treatment step by a wet blast method as described in the third aspect of the invention and a chamfering step by a roller barrel apparatus according to the fifth aspect.

Further, the chamfering step as described in the fourth aspect minimizes the peeling off of the rust preventive paint applied to the corners of each material of the rare earth permanent magnet in the barrel coating step. As a pretreatment of the barrel coating step as in the invention according to claim 6, a rust preventive agent is immersed in the barrel coating step to improve the adhesion of the rust preventive paint in the barrel coating step, or the invention according to claim 7 By repeatedly performing the barrel coating process using different rust-preventive paints as described above, if the rust-preventive paint adhesion is to be improved, a better rust-preventive paint film will be obtained, and the above-mentioned effect will be further improved. Can be enhanced.

[Brief description of the drawings]

FIG. 1 is a flow chart showing the whole process of a rust prevention treatment method for a rare earth permanent magnet according to an embodiment of the present invention.

FIG. 2 is an external perspective explanatory view showing a form of a magnet manufactured by the process shown in FIG.

FIG. 3 is an external perspective explanatory view showing a schematic structure of a roller barrel (chamfering) device used in the present invention.

FIG. 4 is a wet blast (surface treatment) used in the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an external perspective explanatory view showing a schematic structure of an apparatus for performing a method.

FIG. 5 is an external perspective explanatory view showing a schematic structure of a barrel coating device used in the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Nd-Fe-B magnet sintered alloy blank material 2 Nd magnet material 11 Roller barrel device 21 Wet blast barrel container 31 Barrel coating device

Claims (7)

[Claims] A rust-preventive treatment method for a rare-earth permanent magnet, wherein a rust-preventive paint made of a predetermined resin material is applied to the surface of the rare-earth permanent magnet, wherein the surface of the rare-earth permanent magnet material is roughened. A surface treatment step to be performed, and a large number of rare earth permanent magnet materials after the surface treatment step are housed in a predetermined container, and the rare earth permanent magnet material is stirred while stirring the rare earth permanent magnet materials by rotating the container. A barrel coating step of applying a resin rust preventive paint on the surface of the magnet material; and a rust prevention method for rare earth permanent magnets. 2. The rare earth permanent magnet material according to claim 1,
A rustproofing method for a rare-earth permanent magnet, comprising a material of a sintered magnet or a bonded magnet represented by Fe-BR (R is a rare-earth element). 3. A method for rustproofing rare earth permanent magnets, wherein the surface treatment step according to claim 1 is performed by a wet blast method. 4. The method according to claim 1, further comprising, prior to the barrel coating step, a chamfering step of processing an edge portion formed at a corner of each rare earth permanent magnet material into a curved surface. Rust prevention treatment method for rare earth permanent magnets. 5. The rare earth element according to claim 4, wherein the chamfering step according to claim 4 is performed by a roller barrel device that stores a large number of rare earth permanent magnet materials in a predetermined container and rotates the container. Rust prevention method for permanent magnets. 6. A rare earth element, wherein a rust preventive for improving adhesion is immersed in each rare earth permanent magnet material before the barrel coating step according to claim 1 while applying ultrasonic waves. Rust prevention method for permanent magnets. 7. The rare earth permanent coating method according to claim 1, wherein the barrel coating step comprises a base coating step and a top coating step, and in each of these steps, a resin rust preventive paint having a mutually different component is used. Rust prevention method for magnets.