JPS60113403A - Manufacture of rare earth resin magnet - Google Patents

Abstract

PURPOSE:To improve the heat resistance by injection molding with or without applying a magnetic field with the predetermined termperature and within the predetermined pressure range after mixing polyphenylene sulfide resin or the like with intermetallic compound magnetic powder. CONSTITUTION:Polyphenylene sulfide resin (specific gravity is 1.6-20.0 or less) of 20-40vol% or polyether etherketone resin (specific gravity is 1.2-1.3 or less) is mixed with the magnetic powder consisting of cobalt and samarium a residual part of which is subjected to surface treatment with silane coupling agent within a range of temperature from a melting point to a decomposition temperature. After that, the obtained mixture is injection-molded with or without applying a magnetic field within the range of temperature and that of pressure of 1,000- 2,000kg/cm<2>.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention utilizes samarium and cobal 1, which are rare earth magnet powders.
The main component of intermetallic compound powder and polyphenylene sulfide resin t7t relates to a method for manufacturing an anisotropic or isotropic permanent magnet using a mixture consisting of polyether ether lactone resin. 〇Resin magnet by injection molding Compared to sintered magnets, (1) it has better formability and can be made into complex shapes;

(2) Good dimensional accuracy of the molded product.

(3) Good mass productivity.

(4) Mechanical strength is improved.

(5) Magnetic properties are stabilized.

There are advantages such as However, the heat resistance of this resin magnet is
It is significantly inferior to that of sintered magnets.

Therefore, attempts have been made to produce resin magnets with improved heat resistance, and among them, known intermetallic compound magnets whose main components are polycarbonate resin with a capacity of 35% or more, and the balance being samarium and cobalt. Powder (specific gravity 8.2
~8.6. (hereinafter referred to as magnet powder) at a temperature of 260°C.
After kneading at about ℃, the obtained mixture was kneaded at a temperature of about 260℃ and a pressure of 1,300 to 1,500 degrees (a magnetic field was applied with an uneven degree).
A method of manufacturing an anisotropic or isotropic heat-resistant resin magnet by injection molding without any heat-resistance is known.

However, the heat resistance of resin magnets manufactured by such a method is limited to a heat distortion temperature of approximately 140°C (ASTMD
648) was not sufficient, and there was a desire to develop a method for manufacturing base resin magnets with further improved heat resistance.

In view of the above-mentioned viewpoints, the present inventors conducted extensive research in order to provide a method for producing resin magnets with further improved heat resistance from a mixture of a thermoplastic resin and the remainder being magnet powder, and as a result, they found that By using polyphenylene sulfide resin and polyether ether ketone resin from among various thermoplastic resins having heat resistance of about 250 to 300 degrees Celsius, and by surface treating magnet powder with a silane coupling agent, The inventors have discovered that the above object can be achieved and have arrived at the present invention.

That is, the present invention uses polyphenylene sulfide resin (specific gravity 1.6 to 2.01 or less, PP
Mata uses polyetheretherketone resin (specific gravity 1.2 to 1.3, hereinafter referred to as PEEK resin) and magnet powder whose surface has been treated with a 7-run coupling agent to determine the melting point and decomposition of the resin. After kneading in a temperature range between 1000 and 1000
It is characterized by injection molding in the pressure range of ~2000 Kg, with or without applying a magnetic field.

The present invention will be explained in detail below.

In the present invention, PPS resin or PEEK resin is used as the thermoplastic resin. And the usage amount is 2
It is necessary to have a capacity of 0 to 40.

If the capacity is less than 20, molding by injection becomes extremely difficult, and if the capacity exceeds 40, the magnetic properties will be lower than that of conventional products.

Furthermore, it is necessary to use magnet powder that has been surface-treated with a silane coupling agent. Examples of the silane coupling agent include r-mercapto-propyl-trimethoxysilane, 2-styryl-ethyl-trimethoxysilane, N-β-(aminoethyl)r-amino-propyl-trimethoxysilane, β-( Single substances such as 3,4-epoxycyclohexyl]ethyltrimethoxysilane, r-amino-propyl-trimethoxysilane, γ-glycidoxyprobyltrimethoxysilane, phenyltrimethoxysilane, methyldimethoxysilane, and mixtures thereof can be used.

The surface treatment is performed by moistening the magnet powder with a solution of 5 to 20 volumes of a silane coupling agent such as alcohol, and then
This may be carried out by drying at room temperature or higher, preferably at 120 to 150°C. Surface treatment with such a coupling agent imparts water repellency and lubricity to the magnet powder, and improves mainly the mechanical strength of the resulting resin magnet.

The magnet powder that has been surface-treated with a coupling agent is then kneaded with a resin to obtain a mixture. To avoid decomposition, the temperature range is below the decomposition temperature of the resin, i.e. 290-400°C when using PPS resin.
, When PEEK resin is used, it is necessary to carry out the process at 330 to 560°C.

The mixture obtained by kneading is further injection molded in a mold, but the temperature at this time needs to be in the same range as the temperature range during mixing, and the pressure needs to be in the 5-5 range of 1000 to 2000 Iveri. There is. The temperature range is set in this way for the same reason as during kneading (hv), and the pressure is set as above in order to maintain good molding processability.Specifically, If it is less than 1000 V-, the flow of the mixture will be poor and it will be difficult to obtain a molded product with excellent dimensional accuracy, and if it exceeds 2000 Kg/cd, cracks will easily occur in the molded product.

By performing injection molding while applying a magnetic field, it is possible to manufacture an anisotropic resin magnet in which the magnet powder is oriented in a certain direction, and by performing injection molding without applying a magnetic field, it is possible to magnetize in any direction. isotropic resin magnets can be manufactured.

The magnetic properties and mechanical strength of the resin magnet manufactured in this manner are on a par with conventional products, but the heat resistance is significantly improved compared to that of conventional products.

The present invention will be further explained below with reference to Examples.

Example SmCo56 (SmCoB system) and Sm (Coqe* F'6[
120Cu((16Zrqol)z4(Sm2C
ol□ series) magnet powder (average particle size is 5 μm each.

35 μm), pps resin (manufactured by Hodogaya Chemical Co., Ltd., trade name Rydon), PEEK resin (manufactured by Mitsui Toatsu Chemical Co., Ltd., trade name P
EEK National) or polycarbonate resin (manufactured by Engineering Plastics Co., Ltd., trade name: Clastic Dish, referred to as PC resin in the table below), injection molding is performed, and various anisotropies (applied magnetic field of 1.2 to 1 , 60,000 Gauss) and isotropic resin magnets. At this time, the surface treatment of the magnet powder is carried out by stirring the magnet powder in a 7-volume alcoholic solution of a silane coupling agent, filtering it, and then drying the solution adhering to the surface in an oven at 120°C. I went to Yofu. Other manufacturing conditions for these resin magnets are shown in Tables 1 and 2.

The heat distortion temperature, magnetic properties, and transverse rupture strength of the obtained resin magnet were measured according to ASTM D 648.

Transverse rupture strength is 7'l according to ASTM D 790 test method:
), the results are also shown in Tables 1 and 2.

From Tables 1 and 2, the resin magnets manufactured by the method of the present invention have comparable magnetic properties and transverse rupture strength, but have significantly improved heat resistance compared to resin magnets manufactured by the conventional method. I can see that you are doing it.

Claims (1)

[Claims] 20 to 40 volumes of polyphenylene sulfide resin or polyether ether lactone resin. Intermetallic compound magnet powder whose main components are samarium and cobalt, the remainder of which has been surface-treated with a silane coupling agent,
After kneading in a temperature range between the melting point and the decomposition temperature of the resin, the resulting mixture is
A method for producing a rare earth resin magnet, characterized by injection molding in a pressure range of 00015 dl while applying a magnetic field or without applying a magnetic field.