JPH03181104A - Plastic-bonded magnet - Google Patents

Abstract

PURPOSE:To form a magnet of a good characteristic by mixing ferrite plastic magnet pellets and rare earth plastic magnet pellets in an arbitrary ratio and performing magnetic isotropic compression molding or magnetic anisotropic compression molding. CONSTITUTION:The surfaces of oxide magnetic particles of strontium ferrite and barium ferrite and those of rare earth magnetic particles of Sm1Co, Sm2Co17, and Nd-Fe-B are finished separately with a coupling agent and the oxide and rare earth magnetic particles are kneaded separately with thermosetting resin such as epoxy resin and phenol resin, rubber, or other resin to obtain oxide pellets and rare earth pellets. A good magnetic characteristic is obtained without reducing the oxide pellets and oxidizing the rare earth pellets by compression molding of the oxide pellets and the rare earth pellets in the ratio needed for obtaining the required magnetic characteristic.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a bond with magnetic properties intermediate between conventional ferrite plastic magnets and rare earth plastic magnets, and at the same time, ferrite magnets, N d - Fc-
B Improve the temperature coefficient of fa stone and further propose an Araste 1-k bonded magnet that has a positive temperature coefficient with respect to Yl, and R Propose a plastic magnet that has high mechanical strength and does not cause rust. .

rPrior art] Ferrite magnet &! Since the powder and Nd-Fe-D magnet &a powder are directly mixed and kneaded with resin to form an acid form, magnetic properties cannot be effectively obtained, mechanical strength cannot be obtained, and it is difficult to prevent fishing. There is no effect, and there is no description of the effect of improving the magnetic temperature coefficient.Also, as is already known, hard ferrite & Ii powder and rare-L type = Jikai 6O-2230Q5.
1 Weigh a predetermined amount of each Baltic magnet powder, dry mix it with a ball mill, knead it with the resin, and make each &ll.
It is known that by adjusting the blending ratio of powder, it is possible to achieve a temperature coefficient that is between the temperature coefficients of hard ferrite and rare earth cobalt. However, it was not possible to obtain a positive temperature coefficient from O which was below -0.03%/C.

Moreover, using N d -F e -B magnetic powder instead of rare earth cobalt magnet powder makes it difficult to stably obtain a predetermined temperature coefficient.
74114 known as Hado Fellatio
It is described that the composition is such that after mixing the magnetic powder of the magnet and the Nd-Fe-Bd magnet, the mixture is kneaded with the phenol resin.

Motoyama II proposed a plastic bonded magnet in Patent Application No. 63-200844;
1163-200844 is further improved and proposed.

[Problems to be Solved by the Invention] As mentioned above, in the past, rare earth magnets that are easily oxidized and oxide magnets containing oxygen (strontium ferrite, barium ferrite) were used directly or through surface treatment. Rare earth magnets are oxidized due to mixed t1 crosstalk to the extent that
A deterioration in performance was observed, as described in JP-A-60-223095. When mixed with powder, it is possible to obtain a product with a specified temperature coefficient! Although it is said that it is If, it can be clearly understood from this rationale.

Means and action for solving the F problem] As a solution, oxide-based (strontium ferrite, barium ferrite) and rare earth-based (S mlc O% + S m
ic01? , N d -F C8), each magnetic powder is subjected to surface treatment with a camping agent, etc., and then oxidized with a thermosetting W:A resin (epoxy resin, phenol vA11). Separate pellets for the 1I11 compound and the rare earth compound can be obtained by kneading the compound compound and the rare earth compound to 1rIIllIll, respectively.

During pressure molding, these oxide pellets and rare earth pellets! By converting the oxide into an acid form with a side combination tailored to the required magnetic properties, excellent magnetic properties can be obtained without reducing the oxide type or oxidizing the rare E type.

Furthermore, if a mixed magnet is manufactured with this configuration, the oxide magnetic powder and the rare earth magnetic powder will not come into direct contact with each other, and a resin, which is a non-magnetic material, will be interposed between them, which is based on the theory of permanent magnets. It is thought that the magnetic properties will improve, and the temperature coefficient will go from a negative value to 0, and even to a positive value.

1 Example 1 Oxide magnet (strontium ferrite anisotropic magnetic powder)
05~], mixed with t14wt% epoxy resin surface treated with 5wt% coupling agent,
Knead and process strontune and ferrite plastic magnet pellets. Zero-order one isotropic Nd-Fe-88 magnet powder (2-cold thin film type, produced by sintering, casting, atomization equipment) is 0.5~ f& which was surface treated with 1.5wt% coupling agent, and furthermore -05 degree
After repeating surface treatment with ~1.5 wt% of coupling agent, it is mixed with 4 wt% of epoxy resin and kneaded to produce Nd-Fe-B plastic magnet pellets.

There is no problem in the order of pelletizing the oxide magnetic powder and the pelletizing the rare earth magnetic powder. e IJ & 1 stone beret y
+・10wL%20wt%, 30wt%, 40wt%
, 50*t% 60 wt% , 70 t% , so
wt χ,')Qwt%1 ()Owt% was added and mixed, and a sample was manufactured by anisotropic heating compression molding.

No. 114: Manufactured by the above-mentioned strength: per IC material, I
I Htn: 1x, indicates the base for which IJ r was measured.

According to this dry fruit, Strontium Ferrite Plus I
Comparing the case of 111 pieces each of plastic magnets and N d -F c -)) plastic magnets, each is mixed and the normal to the anisotropic addition heat is anisotropic strontium ferrite &! ! Magnetic properties of powder and N d -F c -D
It can be concluded that the magnetic properties of the sample are improved due to the magnetic synergistic effect with the magnetic properties of the magnetic powder. Furthermore, the temperature coefficient measured is shown in 2nd U4.

Even if -) is present, the effect expressed by the effect of different magnetic particles1
If we cross the Idi fields of 1 Tesla and 10 Tesla,
The temperature coefficient to be cultured is determined by the mixing ratio of magnetic particle beleft by each excitation & Ii & Ii field.

] In the case of Tesler, the variation in characteristics is larger than in the case of ]0 Tesler, and it is judged that the range of applications is wider.

When the sample with the formulation 1- was molded into isotropic F (cotton) without applying &IP4, it was found that there was a similar tendency, although the effect on properties was smaller compared to the +A isotropic compressed layer.

Furthermore, it has been found that similar effects can be obtained when phenol resin, rubber, etc. are used as the matrix ellFy.

In addition, the Sm-Co-based magnet Bereft is made by surface-treating Sm-Co-based &11 powder and pelletizing it by the method described in t-L.
Even if the N d -F cn & 1 stone pellets obtained by method E and the strontium ferrite magnet pellets and/or the barium ferrite magnet pellets are mixed in an arbitrary composition and molded, the same results as described above will be obtained. It has been confirmed that this effect can be obtained.

Next, since the specific gravity of each pellet to be mixed is different, each &! For the 4 cases where the powder dispersion was not good, uniform dispersion was obtained by changing the compounding ratio of each magnetic powder and resin and making the specific gravity of each of the above pellets the same. By mixing each pellet in an arbitrary ratio to obtain kneaded tE mixed pellets,
A molded article with uniform dispersion could be obtained.

Effect 1 of the F invention By taking the method 1-1 below, oxide-based (hazardous)
doferrite) &1! Rare earth elements that are easily oxidized with powder
It is now possible to stably mix powder and produce mixed magnets.

As a result, effects that cannot be seen with ordinary magnets such as first-order magnets were obtained.

(1) Since the expensive rare earth magnet is mixed with the expensive oxide magnet, the cost is reduced in proportion to the mixing ratio.

(2) The &ll powder is strongly entangled with the epoxy resin via the coupling agent, and when the magnet is broken, the magnetic powder does not break on the surface, but breaks on the resin part, so the mechanical strength is 1 to 5 times that of conventional products. indicates the value of

(3) Rare earth magnetic powder (particularly Nd-Fe-B) is thoroughly treated with a coupling agent, and the earthen M magnetic powder alone is kneaded with epoxy resin, etc., so that it is well entangled, so no rust occurs. be.

Conventionally, in order to prevent rust with this magnet, the surface of the magnet was treated with anti-rust treatment after being made into 1 stone.

Therefore, costs were reduced.

(4) It has been found that the temperature coefficient of magnetic properties can be controlled over a wide range from n to positive with respect to temperature rise by changing the mixing ratio of lK+ compound type (hard ferrite) magnetic powder pellets and rare earth type magnetic powder pellets.

This is not only used for applications such as magnetic bubbles, but also has a positive temperature coefficient against temperature increases, making it possible to compensate for the temperature of motors such as Q-E type 3 actuators. .

(5) Fill compound type
) ferrite ) magnetic powder and
Each type of rare &l powder is mixed with resin and kneaded into pellets for each type of &l powder, making production management easier and reducing costs.

4, 14 Surface FJ Ql- Explanation No. 10: i When the rare earth plastic magnet beret according to the present invention and the oxide plastic magnet heel are mixed in various proportions and heated and compression molded in a magnetic field, n r ,
Indicates the value of BHIIax.

No. 21'71 separates the cross-type plastic magnet pellets and oxide-based plastic magnets according to the present invention.
It shows the temperature coefficient when T-mixed and heated and compression molded in a magnetic field, and is also shown for the case of an excitation Vi & I field of 1 Tesla and 10 Tesla.

stand (!]

Claims (2)

[Claims] (1) The surface of magnetic powder of an oxide magnet is treated with a coupling agent, and the surface-treated oxide magnetic powder is kneaded with a thermosetting resin or rubber to produce pellets of ferrite plastic magnet. -Co-based magnet and/or
Treating the surface of the magnetic powder of the Nd-FeB magnet with a coupling agent at least once and repeating the drying process,
Thermosetting resin or rubber is kneaded with rare earth plastic magnet powder that has been surface-treated at least once to produce rare earth plastic magnet pellets, and the ferrite plastic magnet pellets and the rare earth plastic magnet pellets are optionally mixed. 1. A plastic bonded magnet characterized by being mixed in a proportion of 1 to 1 and subjected to magnetic isotropic compression molding or magnetic anisotropic compression molding. (2) By adjusting the mixing ratio of the surface-treated magnetic powder and resin, the specific gravity of the ferrite plastic magnet pellets can be adjusted.
3. The plastic bonded magnet according to claim 1, wherein the rare earth plastic magnet pellets have the same specific gravity. The plastic bonded magnet according to claim 2, wherein the plastic bonded magnet is mixed and kneaded to produce pellets.