JP2767982B2 - Manufacturing method of rare earth iron based resin magnet structure - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a permanent magnet structure having a permanent magnet formed on an outer periphery of a support member and used as a magnet of a motor, and more particularly to a rare earth element. The present invention relates to a method for manufacturing a rare earth iron-based resin magnet structure in which a super-quenched powder of an iron-based alloy is fixed in a bulk state with a resin and is integrated with a supporting member.

2. Description of the Related Art FIG. 1 is a block diagram showing an example of a conventional manufacturing process of a rotor magnet used for a motor. The figure is a structural process diagram of a rotor magnet in which a rare earth iron-based resin magnet is directly integrated with a laminated electromagnetic steel sheet support member (Japanese Patent Application No. 63-46232). In the figure, process A is a process in which a magnetic powder and a resin component are mixed. , Compounding process, process B is integral molding, process C is resin curing,
Step D is shaft insertion, and step E is magnetization.

Next, the steps A and B, which are the main points in the figure, will be described in more detail.

First, in step A, an ultra-quenched powder of a rare-earth iron-based alloy and a liquid epoxy resin-encapsulated capsule made of a solid epoxy resin at room temperature are used as a granular intermediate, and a powder epoxy resin hardener and a lubricant are mixed with the intermediate. The compound.

The step B is based on a powder molding method in which the compound obtained in the step A is compressed at room temperature. However, when the compound is compressed in the mold cavity, a green body integrated with the laminated electromagnetic steel sheet is formed. There is a feature in the place.

However, the low molecular weight compound component contained in the epoxy resin which is solid at room temperature causes blocking of the granular compound, and as a result, the step of producing the granular intermediate in the step A, or There was a drawback that the powder moldability in step B was significantly reduced. On the other hand, the polymer compound component contained in the epoxy resin which is solid at room temperature has a drawback that the dimensional accuracy and the integration strength of the green body integrated with the support member obtained in the step B are reduced.

An object of the present invention is to provide a method for producing a rare earth iron-based resin magnet structure having stable dimensional accuracy and integrated strength while maintaining stable powder moldability against the above-mentioned drawbacks.

Means for Solving the Problems The present invention provides a bisphenol A diglycidyl ether having an epoxy equivalent of 600 to 700 at room temperature, 2 to 5 parts by weight, a super-quenched powder of a rare earth alloy of 93 to 96 parts by weight, and an epoxy equivalent of 300 or less. 1 to 2 parts by weight of a capsule containing a liquid epoxy resin is used as a granular intermediate, and 100 parts by weight of the intermediate is mixed with an appropriate amount of a powdered epoxy resin curing agent and 0.2 to 0.5 parts by weight of a lubricant to be compounded. The main points are a process, a process of forming the compound integrally with the support member to form a green body, and a process of integrally heating and curing the resin component of the green body into a steel body. It is.

Operation Hereinafter, the present invention will be described in more detail.

First, the reason for using 2 to 5 parts by weight of bisphenol A diglycidyl ether which is a solid at room temperature and having an epoxy equivalent of 600 to 700 in the present invention is that it has an alcoholic hydroxyl group in its molecular chain, so that it has good affinity with metals. That is, the level of integration strength and dimensional accuracy with the support member can be increased and stabilized, and the powder moldability as a compound can be ensured over a wide temperature range. If the amount is less than 2 parts by weight, it is difficult to maintain the level of the integrated strength, and the compound is not granulated to lower the workability, but the super-quenched powder of the rare-earth iron-based alloy is covered with the resin. This is because unformed portions are generated and rust is generated from these portions. On the other hand, if the content exceeds 5 parts by weight, the content of the ultra-quenched powder of the rare-earth iron-based alloy relatively decreases, and it becomes difficult to secure magnetic properties.

The ultra-quenched powder of a rare-earth alloy referred to in the present invention is, for example, an R ₂ -TM ₁₄ B phase (R is Nd, Rr, TM is Fe, Co) by ultra-quenching a rare-earth iron-based alloy by a melt spinning method. And a metastable state of a permanent magnet material sharing an amorphous phase.
This material is magnetically isotropic, does not require magnetic anisotropy during bulk molding, and generally has a residual flux density of 7.5 kG or more, so it is relatively high even if it is molded into a bulk with resin This is because magnetic properties can be secured. The reason why the ultra-quenched powder of the rare-earth iron-based alloy is specified as 93 to 96 parts by weight is that if it exceeds 96 parts by weight, the integrated strength and dimensional accuracy of the rare-earth-iron-based resin magnet structure decrease. On the other hand, if the amount is less than 93 parts by weight, the magnetic properties are deteriorated though the level of the integration strength and the dimensional accuracy are almost constant.

Next, the microcapsules referred to in the present invention are those in which a liquid epoxy resin is contained. For example, a mononuclear spherical capsule using a formalin condensation resin as a cell is preferable.
The mononuclear spherical capsule ensures uniform dispersibility in the compound, prevents thermal softening of the cell by adjusting the crosslink density of the cell, and increases the chemical resistance to increase the encapsulation amount of the liquid epoxy resin to 70- Up to 85% by weight. The reason why the epoxy equivalent of the encapsulated liquid epoxy resin is set to 300 or less is that if it exceeds 300, the level of integration strength and dimensional accuracy as a rare earth iron based resin magnet structure cannot be maintained. Also, the reason why the weight is specified to be 1 to 2 parts by weight is that if it is less than 1 part by weight, the integration strength and dimensional accuracy as a rare earth iron-based resin magnet structure decrease, and if it exceeds 2 parts by weight, the liquid that flows out during molding This is because the handleability of the green body is reduced due to the epoxy resin. The role in the integral molding of the microcapsules is first to ensure the powder fluidity of the compound and the storage stability due to polymerization inertness. Next is the outflow of the encapsulated liquid epoxy resin due to physical breakage of the microcapsules that occurs when the compound filled in the cavity is compressed. Also, it is a statement that the viscous liquid component flows out due to the breakage of the cell, thereby alleviating the compressive stress and adhering to the support member.

Next, the powdered epoxy resin curing agent referred to in the present invention is dicyandiamide having latent curability and derivatives thereof, various carboxylic acid dihydrazides, amines and derivatives thereof,
One or more powdered epoxy resin hardeners selected from the group such as those described above are required to heat-cur at room temperature both the solid epoxy resin and the liquid epoxy resin encapsulated in microcapsules. The amount is appropriately used.

Next, as the lubricant in the present invention, a lubricant generally used for powder molding materials such as fatty acid metal soaps can be used. However, its melting point is desirably at least higher than the curing temperature of the powdered epoxy resin curing agent used. The reason for setting the melting point higher than the curing temperature is that the liquefaction and vaporization of the lubricant forms a layer with a high concentration of the lubricant at the interface between the green body and the support member and in the green body, thereby deteriorating the integration strength and dimensional accuracy. It is to prevent. In addition, the reason specified in 0.2 to 0.5 parts by weight is 0.5
When the amount exceeds the weight part, the lubricant forms a high-concentration layer at the time of heat curing of the green body and causes a decrease in integration strength.
If the amount is less than 2 parts by weight, hardening for improving powder moldability can hardly be obtained.

Examples Hereinafter, the present invention will be described with reference to Examples.

First, the supporting member used in the embodiment of the present invention has a thickness of 0.5 mm.
This is an example of a thin-walled annular resin magnet structure that is a laminated electromagnetic steel sheet obtained by punching out an electromagnetic steel sheet of 48 mm in outer diameter and 8 mm in inner diameter and laminating 22 sheets, and integrally forming an annular resin magnet having a thickness of 1.10 mm on the outer peripheral surface thereof. However, the present invention is not limited to this.

Next, the components of the present invention and comparative examples were based on the following parts by weight.

Epoxy resin solid at room temperature 4.0 Ultra quenched powder of rare-earth iron-based alloy 93.7 Microcapsules containing liquid epoxy resin 1.3 Powder epoxy resin hardener 0.52 Lubricant 0.4 However, in the present invention, the epoxy equivalent of room temperature solid epoxy resin has an epoxy equivalent of 600 to 700. The liquid epoxy resin which is bisphenol A diglycidyl ether and is encapsulated in microcapsules needs to have an epoxy equivalent of 300 or less.

Next, the steps of manufacturing the rare earth iron-based resin magnet structures of the present invention example and the comparative example were based on the following (a) and (b) in step A of FIG.

(A) A step of using a rapidly quenched powder of an epoxy resin, a rare earth iron-based alloy, and microcapsules, which are solid at room temperature, as a granular intermediate having a particle diameter of 53 to 500 μm.

(B) A step of mixing the granular intermediate with a latent amine-based epoxy resin curing agent having an average particle diameter of 10 μm and a lubricant (calcium stearate) having an average particle diameter of 6 μm to form a compound.

 Next, in the step B of FIG. 1, the following (c) was used as a reference.

(C) a step of directly molding a green body integral with the support member which has been previously heated at room temperature or higher to the softening temperature of the solid epoxy resin while consolidating the compound.

 Next, FIG. 1 step C was based on the following (d).

(D) a step of integrally hardening the green body and the support member by heating and curing the green body epoxy resin component;

In addition, the integrated strength of the rare earth iron-based resin magnet structure obtained by the above process is determined by fixing the laminated electromagnetic steel sheet as a support member and uniformly setting the crosshead speed on one end face of the resin magnet.
As the shear fracture load when a load was applied at a rate of 10 mm / min, the dimensional accuracy was obtained by changing the rate of expansion (expansion) of the outer diameter of the rare-earth iron-based resin magnet structure on the basis of a mold.

(Effect of Bisphenol A Diglycidyl Ether having Epoxy Equivalent of 600 to 700) A rare earth iron-based resin magnet structure was prepared using four kinds of bisphenol A diglycidyl ether having different epoxy equivalents.

FIG. 2 is a characteristic diagram showing dimensional accuracy and integration strength of bisphenol A diglycidyl ether with respect to the epoxy equivalent, and FIG. 3 is based on 10 ° C. with respect to the epoxy equivalent of bisphenol A diglycidyl ether with 45 ° C. at room temperature. 3 is a characteristic diagram showing stability of powder flowability of the compound. (Powder fluidity is based on JIS or 2502) As is clear from FIGS. 2 and 3, the epoxy equivalent is 600
Within the range of ~ 700, the dimensional accuracy and the integration strength are excellent, and the compound powder formability is also excellent. That is, when the epoxy equivalent is less than 600, blocking occurs due to the low molecular weight compound component contained in the resin component, and the yield at the stage of obtaining the granular intermediate in the step A in FIG. Not only does the powder moldability in step B decrease, but also the level of integration strength and dimensional accuracy become unstable.
On the other hand, when the epoxy equivalent exceeds 700, the dimensional accuracy and the integration strength are reduced due to the influence of the polymer compound component.

(Effect of epoxy equivalent of liquid epoxy resin encapsulated in microcapsule being 300 or less) FIG. 4 shows a microcapsule using bisphenol A diglycidyl ether having an epoxy equivalent of 600 to 700 as a solid epoxy resin at room temperature. FIG. 4 is a characteristic diagram showing the integration strength of a rare earth iron-based resin magnet structure with respect to the epoxy equivalent of a contained liquid epoxy resin.

As is clear from the figure, the liquid epoxy resin to be encapsulated in the microcapsules cannot maintain the level of integrated strength unless the epoxy equivalent is 300 or less. (Lubricant 0.2 ~
The effect of 0.5 parts by weight) The presence of the lubricant is effective in smoothly and continuously repeating the molding operation in the step B in FIG. 1, and is also effective in transmitting pressure in the cavity.

FIG. 5 is a characteristic diagram showing the dimensional accuracy and the integrated strength with respect to the lubricant content, and FIG. 6 is a graph showing the flow rate based on JIS or 2502 of the compound with respect to the lubricant content at 20 ° C. It is a characteristic view which shows the ratio based on 0.1 weight part.

If the amount of the lubricant is less than 0.2 parts by weight, the dimensional accuracy and the fluidity decrease, and if the amount exceeds 0.5 parts by weight, a portion having a high concentration of the lubricant or a layer of the lubricant itself is formed, so that the integral strength decreases.

Effects of the Invention According to the method for producing a rare earth iron-based resin magnet structure of the present invention, it is possible to improve the productivity of the compound and stabilize the powder moldability, and particularly to specify the resin composition component and its amount. As a result, the productivity of the compound and the powder moldability thereof can be improved, and a rare earth iron-based resin magnet structure having improved dimensional accuracy and integrated strength can be obtained, and its industrial value is great.

[Brief description of the drawings]

FIG. 1 is a block diagram of the manufacture of a rotor magnet according to the present invention, FIG. 2 is a characteristic diagram showing dimensional accuracy and integrated strength with respect to an epoxy equivalent of an epoxy resin solid at room temperature, and FIG. Characteristic diagram showing the stability of the fluidity of the compound to the temperature with respect to the epoxy equivalent of the resin,
FIG. 4 is a characteristic diagram showing the integration strength with respect to the epoxy equivalent of the liquid epoxy resin contained in the microcapsule, FIG. 5 is a characteristic diagram showing the integration strength and dimensional accuracy with respect to the lubricant content, and FIG. FIG. 4 is a characteristic diagram showing a fluidity with respect to a lubricant content.

Claims (2)

(57) [Claims] (1) 2 to 5 parts by weight of bisphenol A diglycidyl ether solid at room temperature having an epoxy equivalent of 600 to 700, 93 to 96 parts by weight of a super-quenched powder of a rare earth alloy, and 1 to 2 parts by weight of a capsule containing a liquid epoxy resin. Into a granular intermediate, mixing 100 parts by weight of this intermediate with an appropriate amount of a powdered epoxy resin curing agent and 0.2 to 0.5 parts by weight of calcium stearate to form a compound, and molding the compound integrally with a support member A method for producing a rare earth iron-based magnet structure, comprising: a step of forming a green body; and a step of integrally hardening the green body and the support member by heat-curing a resin component of the green body. 2. The method according to claim 1, wherein the liquid epoxy resin encapsulated in the capsule has an epoxy equivalent of 300 or less.