JPS63161603A - Permanent magnet - Google Patents

Abstract

PURPOSE:To obtain a rare earth group permanent magnet having not only excellent magnetic characteristics but also superior corrosion resistance by applying the curing agent of a thermo-setting resin onto the surface of the rare earth permanent magnet such as a sintered rare earth magnet, a rare earth plastic magnet, etc. CONSTITUTION:The curing agent of a thermo-setting resin is applied onto the surface of a rare earth permanent magnet such as a sintered rare earth magnet, a rare earth plastic magnet, a rare earth anisotropic magnet, etc. The curing agent of the thermo-setting resin such as phthalic anhydride having carboxy as a curing agent at a time when a main agent consists of an epoxy resin, an aliphatic group amine, an aromatic group amine, etc. is applied onto the surface of a molded form or a sinter composed of a rare earth magnet alloy, thus improving the corrosion resistance of the molded form or the sinter.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Field of Application) This invention is a magnet with excellent corrosion resistance that is used in fields where permanent magnets are used, such as automobiles, home appliances, audio products, and watches. It concerns permanent magnets.

(Prior technology) In recent years, permanent magnets with excellent magnetic properties have been used in place of conventional alnico magnets and ferrite magnets.

Rare earth permanent magnets such as S m -'Co-based and Nd-Fe-based permanent magnets are becoming popular, and their uses tend to expand more widely.

Conventionally, as this type of rare earth permanent magnet, for example, Nd-
Fe-B-based water 1, Nd-Fe-B manufactured by the process of Nd-Fe-B powder forming → sintering in magnets
Nd manufactured by injection molding or compression molding using sintered magnets or ultra-quenched Nd-Fe-B powder.
-Fe-B plastic magnets, and Nd-Fe-B-based Mizuku magnets manufactured by increasing density and anisotropy by the Horat-Toprene method or the upset method.

(Problems to be Solved by the Invention) Although these rare earth permanent magnets have considerably superior magnetic properties compared to the conventional alnico magnets and ferrite magnets described above, they have a problem in that their corrosion resistance is not very good. there were.

(Purpose of Origin 1j) This invention was made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a permanent magnet of the above-mentioned type that has excellent magnetic properties and excellent corrosion resistance. It is an object.

[Components of the invention (Failure to solve the problem) The permanent magnet according to the present invention is a rare type sintered magnet.

It is characterized by being made by coating the surface of a rare earth permanent magnet such as a rare earth plastic magnet or a rare earth anisotropic magnet with a thermosetting resin curing agent.

The mud permanent magnets to which this invention is applied include rare earth sintered magnets made by powder molding and sintering, plastic rare earth magnets made by injection molding or compression molding using ultra-quenched rare earth magnet powder, and true breath magnets. There are also rare earth magnets that are made with higher density or anisotropy through upsetting.

As for the component composition of the permanent magnet alloy, for example, as a rare earth-cobalt-based permanent magnet, RMS system, for example, Sm (Co, Fe, CuII 66) 5 system, R2M
17 series, for example Sm2 (Co, Fe, Cu number/war) +7
There are rare earth-iron permanent magnets such as Rl, , s, (F e (N i, M
n, Go) 1α Xβ, where R is one or more rare earth elements, X is one or more of B, C, N, St, and P, and M is Ti, Zr, and H.
f, V, Nb, Ta, Cr.

Mo, W, A sentence, Zn, Ga, In, TJI
More preferably, 0.60≦α
There are some that satisfy ≦0.85.0<β≦0.15.0≦γ≦0°01, but there is no particular limitation.

The permanent magnet according to the present invention has a hardening agent for a thermosetting resin, for example, a phthalate containing carboxy, which is a hardening agent when the main material is an epoxy resin, on the surface of a molded or sintered body made of the rare earth magnet alloy. Apply acid anhydrides, aliphatic amines, aromatic amines, etc. to
#It is characterized by improved eating habits.

(Example 1) After adding 2.0% by weight of epoxy resin to ultra-quenched 3ONd-1,0B-Fe magnet powder (particle size 200 gm or less), it was added with a pressure of 7.0 ton/am2. By compression molding, a cylindrical molded body with a diameter of 11 mm and a height of 10 mm was obtained.

Next, the molded body was heated to 150°C! Cure treatment was performed by heating under the conditions of X4Hr.

Next, on the surface of the plastic magnet subjected to the above-mentioned curing treatment, phthalic anhydride (HV-504 manufactured by Nippon Bellnox Co., Ltd.) having carboxy, which is a curing agent for a thermosetting resin (in this case, an epoxy resin), was applied. After applying two types of XV-2230) to a thickness of approximately 30 gm on the entire surface,
It was dried by heating at 120°C for 1 hour.

For comparison, we prepared plastic magnets that were exactly the same except that they were not coated with phthalic anhydride having L carboquine, and each magnet was subjected to conditions of a temperature of 50'C and a humidity of 98% for 9 hours and 98 hours. damp, 7. *A test was conducted to visually check for the presence or absence of rust. For reference, the magnetic properties before and after the wet test (maximum energy XA (B
H) max) was investigated. These results are shown in Table 1.

As is clear from the results shown in Table 1, in the case of samples + and 1 in which no thermosetting resin curing agent was applied to the surface, i!
! ! After the moisture test, rust was observed all over the surface, and it was confirmed that the magnetic properties were degraded due to deterioration near the magnet surface.

On the other hand, in the case of the 2°3 sample coated with phthalic anhydride containing carboxy as a hardening agent, no rust was observed after the wet test, and there was no deterioration in magnetic properties. It did not occur.

(Example 2) A compact with a diameter of 20 mm and a height of 8 mm was obtained by compression molding 33Nd-1,38-Fe alloy fine powder with an average particle size of 4.07 zm at a pressure of 1.0 Lon/cm2cy. 0 Then, the molded body was placed in an Ar atmosphere for 11
After sintering under the conditions of 00℃xiHr, 600℃XIH
Aging treatment was performed under the conditions of r.

Next, aliphatic amines (HY-308, HY-68 manufactured by Nippon Bellnox Co., Ltd.), which are curing agents for thermosetting resins (epoxy resins in this case), are applied to the surface of the obtained sintered magnets.
0) was coated on the entire surface to a thickness of about 30 μLm, and then heated at 120° C. for 1 hour to dry.

For comparison, we also used a sintered magnet that was completely the same except that it was not coated with the aliphatic amine (sample 4 in Table 2).
and the main ingredient epoxy resin (M made by Nippon Bellnox)
The same sintered magnet as above (sample 5 in Table 2) coated only with E-105) to a thickness of about 10 Bm, and the epoxy resin as the main ingredient and the aliphatic resin as the curing agent. Approximately 10p of a mixture of 2:1 and amines is applied to the entire surface.
Prepare the same sintered magnet as above (No. 6 in Table 2) coated with a thickness of m, and apply each magnet (No. 4 to 8).
On the other hand, a humidity test was conducted under the conditions of temperature 50''C2 humidity 98% 9 hours 96 hours.

The presence or absence of rust was visually inspected. For reference, the magnetic properties (maximum energy product (BH) ma
x) was determined. These results are shown in Table 2.

As is clear from the results shown in Table 2, in the case of test sample 4 without a thermosetting resin curing agent applied to the surface,
After the wet test, rust was observed all over the surface, and it was confirmed that the magnetic properties had significantly deteriorated. In addition, in the case of test sample 5, in which only the main compound was applied to the surface of the sintered magnet,
Rust formation was also observed in both cases of test positive and 6 in which the main agent + curing agent (mixing ratio was 2:1) was 97D.
The magnetic properties were also significantly lowered.

On the other hand, in the case of sample 1b, 7.8, in which only the aliphatic amine as a curing agent was applied to the entire surface, 1,'l fl
No occurrence of t^ was observed after the FJ test, and no deterioration of magnetic properties occurred.

[Effects of the Invention] As explained above, the permanent magnet according to the present invention is made by applying a hardening agent of a thermosetting resin to the surface of a rare earth permanent magnet made of a molded body, a sintered body, etc. Therefore, not only does it have excellent magnetic properties, but it also has very good corrosion resistance.

Claims (2)

[Claims] (1) A permanent magnet characterized by applying a hardening agent of a thermosetting resin to the surface of a rare earth permanent magnet such as a rare earth sintered magnet or a rare earth plastic magnet. (2) The permanent magnet according to claim (1), wherein the thermosetting resin curing agent is an epoxy resin curing agent.