JPH01220417A - Manufacture of resin magnet - Google Patents

Abstract

PURPOSE:To facilitate a mass production by employing as a bonding agent component one or more kinds of microcapsules with a thermally polymerizable resin component as an enclosed substance, mechanically damaging part or all of the capsules to discharge the substance at the time of forming a green body of bonding agent and a magnet material, and then polymerizing and curing the agent. CONSTITUTION:One or more types of microcapsules with a thermally polymerizable resin component as an enclosed substance are employed as a bonding agent component at the time of manufacturing a resin magnet, and part of all of the capsules are mechanically damaged to discharge the substance at the time of forming a green body of the agent and a magnet material. The agent component is polymerized and cured to manufacture the resin magnet. The magnet has Fe100-x-y-zCOxNdyBz (where 0<=x>=30, 10<=y<=28, 2<=z<=12, y+x<=34, 6z+y>=34, and the x, y, z represent the atomic% of the CO, Nd, B) and several tens to several hundreds of particles each including magnetic anisotropy.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for producing a resin magnet using a thermopolymerizable resin composition as a binder, and more specifically to a method for producing a resin magnet using a thermopolymerizable resin composition as an encapsulating material. The present invention relates to a method for producing a resin magnet using one or more of these as a binder component.

Conventional technology As a resin magnet that exhibits advanced magnetic performance, for example, Ss
(Co, Cu, Fe, M)n (However, M is one or two of the elements belonging to Groups ■, V, ■, and ■ of the periodic table.
A combination of more than one species, n is generally an integer from 5 to 9)
Resin magnets are known that are made by compression molding in a magnetic field with 2 to 6% by weight of a binder. As the binder for the resin magnet, an epoxy resin composition that is liquid at room temperature is generally used. Here, the epoxy resin composition refers to an epoxy resin and 3
It is composed of a curing agent that creates dimensional cross-linking, and various additives such as curing accelerators and plasticizers that are added as necessary.The binder, that is, the epoxy resin composition, determines the quality of the resin magnet. It is known to have a significant impact on maintenance and security.

The above-mentioned epoxy resin is a general term for compounds having at least two or more oxirane rings in one molecule as shown in the following general formula.

However, Y in the above formula is a polyfunctional halohydrin, for example, a residue of a reaction product of epichlorohydrin and polyhydric phenol. Polyhydric phenols useful herein are resorcinol and various bisphenols obtained by condensation of phenol with aldehydes or ketones. A typical bisphenol is 2,2'-bis(P-
Bisphenol A (hydroxyphenylpropane)
.

Examples include 4,4'-dihydroxybiphenyl, 4,4'-di□hydroxybiphenylmethane, and 2,2'-dihydroxydiphenyl oxide. Specifically, the most common epoxy resin is represented by the following general formula.

However, in the above formula, R is a divalent group selected from a saturated alkylene group having 1 to 8 carbon atoms, oxygen, and a sulfone group, y is O or an integer of 25, and n is 0 or 1.

Condensate of epichlorohydrin and bisphenol A (D
GEBA) can be exemplified by To(.

Next, the above-mentioned epoxy resin curing agent is used, for example, in resin magnets as disclosed in JP-A-60-37106 and JP-A-60.
JP-A-207302 discloses an azole compound having an amino group, which is specifically imidazoles represented by the following general formula.

In the above formula, R1, R2, R3 and R4 are individually selected from hydrogen, a lower alkyl group, a phenyl group and a lower alkylphenyl group. For example, imidazole, 2-
Ethyl-4-methylimidazole.

These include 1-benzyl-2-methylimidazole, 1-methylimidazole, 1,2-dimethylimidazole, and the like.

Problems to be Solved by the Invention However, imidazoles generally have a high melting point (generally 200%
Since it is a solid with a temperature of 100.degree. Furthermore, an epoxy resin composition in which an epoxy resin and its curing agent are mixed gradually polymerizes, thereby increasing its viscosity. The thickening of the epoxy resin composition is the same even when mixed with a magnet material.
(Co, Cu, Fe, M) When manufacturing a resin magnet that generally requires magnetic anisotropy, the degree of magnetic field orientation decreases due to the thickening of the epoxy resin composition, for example, the residual magnetic flux of the resin magnet The density will decrease depending on the degree of viscosity increase. This eventually leads to gelation, and as a result, it becomes difficult to manufacture the resin magnet itself. Furthermore, Ss
(Co, Cu, Fe.

When magnetic anisotropy needs to be applied as in M)n, the epoxy resin composition is usually liquid at room temperature in order to facilitate magnetic field orientation. Since the epoxy resin composition used as the binder is liquid at room temperature, it does not have the fluidity as a powder molding material, making it extremely difficult to mold green bodies of arbitrary shapes. Furthermore, the mechanical strength of the green body itself is extremely low, making it extremely difficult to maintain and ensure quality and performance. In order to overcome this drawback, many ideas and proposals have been made regarding the form of the binder used in green body molding. For example, Japanese Unexamined Patent Publication No. 55-63808 discloses molding a green body using a tri-blend of a magnet material and a finely powdered thermopolymerizable resin. Although this method is effective in ensuring the quality of the green body, it requires a large amount of binder component in order to homogeneously wet the surface of both sides of the magnet material with fine powder thermal polymerization resin when heating the green body. As a result, the density of the magnet material decreases, which inevitably leads to a decrease in magnetic performance. On the other hand, JP-A-60-19
No. 4509 discloses that a magnet material is coated with a thermopolymerizable resin composition that is solid at room temperature, and a green body is molded at a temperature higher than the softening temperature of the thermopolymerizable resin composition to soften the thermopolymerizable resin composition. It is disclosed that the green body is demolded from the mold at a temperature lower than the above temperature. Although this method has a certain effect on maintaining and ensuring the quality and performance of the green body, it requires heating and cooling based on the softening temperature of the binder during molding of the green body, which requires a large amount of resin magnets to be used industrially. Production involved extremely difficult problems in terms of equipment maintenance and management.

Means for Solving the Problems The present invention has been made in view of the above background, and includes one or more types of microcapsules containing a thermopolymerizable resin component as a binder component. When a green body is formed with a magnetic material and a magnetic material, part or all of the microcapsules are mechanically destroyed to elute the substance contained in the capsules, and then the binder is polymerized and hardened.

action The present invention will be explained in more detail below.

First, the thermopolymerizable resin component referred to in the present invention can be exemplified by an epoxy resin composition commonly used as a binder for resin magnets. The constituent components of the epoxy resin composition as used herein generally include the epoxy resin, a curing agent for three-dimensionally cross-linking the epoxy resin, and various additives added as necessary. The above-mentioned epoxy resin is a general term for compounds having two or more oxirane rings in at least one molecule. Further, as curing agents for the epoxy resin, aliphatic polyamines, polyamides, heterocyclic diamines, and aromatic polyamines are used.

Any compound that undergoes ring-opening polymerization of the oxirane ring, such as acid anhydrides, aromatic nuclear aliphatic polyamines, imidazoles, dicyandiamide and its derivatives, organic acid didrazide and its derivatives, can be used. . Furthermore, a simple epoxy resin composition may be composed of an epoxy resin and the above-mentioned curing agent, and if necessary, various plasticizers such as a monoepoxy compound having one oxirane ring in one molecule, etc. Various curing accelerators such as tertiary amines can also be added as constituents.

Next, the microcapsules in which the above thermopolymerizable resin constituents are included as encapsulating substances as used in the present invention are, for example, microcapsules containing appropriately selected microcapsules (also known as 1n-situ polymerization in which suspension polymerization is carried out in the presence of liquid encapsulating substances at room temperature). Monomers generally used to form microcapsules include vinyl chloride, vinylidene chloride, and acrylonitrile.

Styrene, vinyl acetate, methacrylic acid esters and various crosslinking agents may be mentioned, which are used as copolymers. The thermopolymerizable resin component used as the encapsulating material here is one or more appropriately selected from epoxy resins, curing agents, and various additives added as necessary, and they are liquid at least at room temperature. Furthermore, it is necessary that the encapsulating substance and the microcapsules are chemically inert to each other. In addition, the form of the microcapsule is preferably a mononuclear spherical capsule, which is smaller in diameter than the particle size of the magnetic material.

Next, the magnet material that can be used in the present invention is 5ffi (Co
, Cu, Fe, M)n, Mo-nFe203 (where M is one or more selected from the group of B a T S t and P b, and n is 4.5 to 6.2). Any particulate material commonly used in resin magnets, such as 1:'e+0o, can be used, but 1:'e+0o is particularly preferable.
-X-y-z Cox Ry Bz (However, R
is Nd or/and Pr, o≦X≦30.10≦y≦
28.2≦2≦12. y+z ≦ 34.6z
+ y ≧ 34, and x, y, z are each C
The particles are Fe-B-R particles having a particle diameter of several tens to hundreds of μm and have a magnetic anisotropy expressed as (representing atomic % of R, B). However, such Fe-B-R magnet materials can be produced by an ultra-quenching method such as a single roll method as described in JP-A No. 59-6439, and can be used as is, or after heat treatment, the grain size can be adjusted as appropriate. It is possible to use even magnetically isotropic materials such as those that have been adjusted. In addition, AQ, Si, Gu, etc. may be added to the Fe-B-R magnet material as long as it does not impair the characteristics of the basic permanent magnet material.
, Zn, and other elements may be mixed or regularly substituted.

As described above, microcapsules containing at least one or more thermosetting resin constituents are used as the binder component of a resin magnet, and the combination is a thermopolymerizable resin that is solid at room temperature. When a resin magnet is composed of the thermopolymerizable resin component ■ that is liquid at room temperature, and the microcapsule O1 magnet material 0 that contains the thermopolymerizable resin component that is liquid at room temperature as an encapsulating material, [■10 10 + (1)
].

[■10+O1], to+o+o1. [O+Q] can be mentioned. However, when using (2), care must be taken so as not to have a significant effect on the fluidity of the powder molding material, which is one of the important effects of the present invention, and on the mechanical strength of the green body.

The above-mentioned combination, that is, a resin magnet material prepared by preparing microcapsules containing at least 181 or more types of thermopolymerizable resin constituents as a binder component together with a magnet material, is made into a green body according to the conventional method of powder molding. If necessary, apply a magnetic field. The mold for applying a magnetic field has a structure in which non-magnetic yokes and magnetic yokes are alternately combined to surround the cavity as required, and a magnetizing coil is arranged on the outside. Alternatively, a structure may be used in which a magnetizing coil is embedded in the outer periphery of the cavity. In this method, a magnetizing coil is connected to a high voltage, low current type power source to generate a magnetic field of a predetermined strength within the cavity. Furthermore, a mold is used in which an alignment yoke having corresponding magnetic pole portions is installed at predetermined positions around the cavity, and a conductive wire is provided within the yoke. In this method, conductive wires installed in the orientation yoke are energized by passing current through them. Therefore, an instantaneous DC power source that inputs a commercial frequency AC power source and generates a pulse current using an all-thyristor full-wave phase control method, or a predetermined DC voltage. Step-up rectification to
Connect to an instantaneous DC power source that charges the capacitor group and then discharges it via a thyristor.

However, if the magnet material is magnetically isotropic, a mold having the above configuration is not necessary. In either case, the resin magnet material filled in the cavity is compressed to increase its density. At the stage of increasing the density, the microcapsules are mechanically destroyed by the magnetic material, and the thermopolymerizable resin component that is the encapsulated substance is eluted. The thermopolymerizable resin constituents eluted from the microcapsules are densified (or, if necessary, the magnet material is By mixing them with each other at the stage of magnetic field orientation), they become a normal thermopolymerizable resin composition, that is, a binder. The green body, which has been sufficiently densified, is then demagnetized as necessary in the cavity and removed from the mold.

Furthermore, after demolding, a thermopolymerizable resin composition, ie, a binder, is polymerized and cured to form a resin magnet.

As described above, according to the method for manufacturing a resin magnet according to the present invention, it is easy to mix the binder, that is, the thermopolymerizable resin constituent components. In addition, even after mixing, the chemically active ingredients are isolated by microcapsules, so they have good storage stability (based on the polymerization reaction) and do not thicken.Furthermore, fluidity as a powder molding material is ensured. Alternatively, it has advantages such as having almost no effect on the movement of the magnetic material that requires magnetic field orientation, and no need for heating and cooling based on the softening temperature of the binder during green body molding, and has advanced magnetic performance. Quality when manufacturing resin magnets.

This results in an effective effect on maintaining and securing performance.

Example Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1゜Sm (Co o, sse, CB o, +o+, F
e O, 2+4. zr0.017) 7. The alloy consisting of z3 was solution treated at 1150°C for 24 hours, then aged at 800°C for 24 hours, and subsequently at 600°C for 1 hour. This alloy is crushed and classified according to conventional methods,
By blending, a magnet material having a particle size of 53 to 200 μm was prepared. On the other hand, diglycidyl phenyl ether represented by the following general formula, that is, 4,4'-bis(2,3
- By suspension polymerization of methyl methacrylate and acrylonitrile in the presence of (epoxypropyl) phenyl ether, a so-called 1n-situ polymerization method, an epoxy resin that is liquid at room temperature is used as an encapsulating material, and methyl methacrylate and acrylonitrile are co-polymerized. Microcapsules with polymer cells were prepared. The content of the epoxy resin as an encapsulating substance was 70% by weight, and the average particle diameter was 16 μm. In addition, 2-ethyl-4-methylimidazole was prepared as one of the thermopolymerizable resin constituents to obtain a resin magnet material having the following composition and capable of being subjected to powder molding.

5s (Co, Cu, Fe, Zr) 7...9
5.9% by weight microcapsules・・・・・・・・・・・・
・・・・・・・・・・・・4.0% by weight 2-ethyl-4-methylimidazole・・・・・・・・・・・・・・・・・・0.1% by weight Above A powder molding machine that can make resin magnet material magnetically anisotropic in the axial direction inside a cylindrical cavity produces 15 KO
A green body with a diameter of 10 mm was molded under a pressure of 8 tons/cnf in a magnetic field of e. In addition, at the stage before molding, it takes 50 to 60 seconds.
Powder flowability of ec/50g was observed, but the surface of the green body was slightly moist due to diglycidyl phenyl ether eluted by mechanical destruction of the microcapsules. Furthermore, no cracks or partial loss of the magnetic material were observed in the obtained green body. By heating such a green body at 120°C for 30 minutes, the density becomes 6.
The magnetic properties of the 85g/cj resin magnet are a residual magnetic flux density of 7.6KG and a maximum energy product of 12.5MGOe.
Met. Furthermore, even if resin magnets are manufactured under the same conditions at the stage before green body molding, that is, from resin magnet materials stored at 40°C for 30 days, no changes are observed in moldability, green body appearance, or magnetic properties. There wasn't.

Comparative example 1゜ Sm (Co) prepared under the same conditions as Example 1.

Cu, Fe, Zr) 796.0% by weight, diglycidyl phenyl ether, i.e. 4,4′-bis(2°3-epoxypropyl)phenyl ether, 3.8 parts by weight, 2
-0.2 parts by weight of ethyl-4-methylimidazole was mixed to immediately produce a resin magnet. Because the fluidity of the powder molding material is impaired due to diglycidyl phenyl ether, it is difficult to fill the cavity homogeneously, and part of the magnet material easily falls off at the green body stage (difficult to handle). The magnetic properties of a resin magnet with a density of 6.5 g/- were as follows: residual magnetic flux density of 6.8 K G
.

The maximum energy product was 10.6 MGOe, and when it was stored as a resin magnet material at 40° C. for 3 days, it was already difficult to form a green body.

Example 2 A quenched ribbon of Nd+s, F67s, 3TO was compressed at room temperature to form a green body, hot compressed at 700°C, and then diamond tube centered to obtain a relative density of 98-99% and an axis of easy magnetization. The alloy was taken in the direction of compression. This alloy was pulverized, classified, and blended according to a conventional method to prepare a magnet material having a particle size of 53 to 200 μm. On the other hand, 11% butyl glycidyl ether substituted DG
Microcapsules are produced using a so-called 1n-situ polymerization method in which vinylidene chloride and acrylonitrile are suspended and polymerized in the presence of EBA, using an epoxy resin that is liquid at room temperature as an encapsulating material, and using a copolymer of vinylidene chloride and acrylonitrile as cells. adjusted.

Furthermore, microcapsules were prepared in which 4-methylhexahydrophthalic anhydride was used as an encapsulating material and cells were made of a copolymer of vinylidene chloride and acrylonitrile. The content of the encapsulated substance in these microcapsules is 70% by weight, and the average particle diameter is 10 μm. In addition, imidazole is prepared as a curing accelerator as a component of the thermopolymerizable resin.
A resin magnet material having the following composition was used.

Nd15. Fe75. B10...97% by weight Microcapsule I...2.0% by weight Microcapsule ■...0.9% by weight Curing accelerator...
・・・・・・・・・・・・・・・0.1% by weight However, the above microcapsules ■ and ■ contain 11% butyl glycidyl ether-substituted DGEBA and 4-methylhexahydrophthalic anhydride as encapsulating substances, respectively. This is what I did.

The above resin magnet material was molded into a diameter of 1 in a magnetic field of 15 KOe at a pressure of 8 ton/cj using a powder molding machine under the same conditions as in Example 1.
It was made into a green body of 0 mm. In addition, at the stage before molding, 5
Powder fluidity of 0 to 60 sec/50 g was observed, but the surface of the green body was in a wet state due to elution of the substance contained in the microcapsules. The magnetic properties of a resin magnet made by heating such a green body at 120° C. for 1 hour were a residual magnetic flux density of 8.9 KG and a maximum energy product of 16 MGOe. In addition, in the stage before forming the green body, that is, the resin magnet material was heated at 40℃ for 30 minutes.
Even when resin magnets were manufactured under the same conditions from those stored for several days, no change was observed in the moldability, appearance of the green body, or magnetic properties.

Effects of the Invention As described above, according to the method for producing a resin magnet based on the present invention, it is easy to mix the binder, that is, the thermopolymerizable resin constituent components. Furthermore, even if the thermopolymerizable resin component is liquid at room temperature, it can be molded into a green body while being isolated from other components using microcapsules, which not only ensures fluidity as a powder molding material, but also allows chemical It also has excellent storage stability as it can maintain an inactive state.

(During storage as a resin magnet material, the thermopolymerizable resin components do not thicken due to mutual polymerization, and the magnet material can move freely as individual independent particles.) It is effective in increasing the degree of orientation in medium powder molding.It is also highly effective because it does not require heating or cooling based on the softening temperature of the binder, which is a thermopolymerizable resin composition, during green body molding. It is clear that this method is effective in maintaining quality and performance in manufacturing resin magnets with magnetic performance.

Claims (1)

[Claims] (1) One or more types of microcapsules containing a thermopolymerizable resin component as an encapsulating material are used as a binder component, and a part or all of the microcapsules are used when forming a green body with the binder and a magnetic material. A method for producing a resin magnet, in which the encapsulated substance is eluted by mechanically breaking the magnet, and the binder component is then polymerized and cured. 2 Magnet material is Fe100-x-y-zCOxNdyB
z (however, o≦x≧30, 10≦y≦28, 2≦z≦1
2, y+x≦34, 6z+y≧34, and x, y, z
are respectively expressed as atomic percent of Co, Nd, and B),
2. The method for producing a resin magnet according to claim 1, wherein the resin magnet has magnetic anisotropy and is a particle of several to several hundred micrometers.