JPS59179638A - Plastic magnet composition - Google Patents

Abstract

PURPOSE:The titled composition having excellent magnetic characteristics and high reliability and prevented from being oxidized in air at high temperatures, prepared by mixing a plastic with a dye-coated magnetic metal powder. CONSTITUTION:A plastic is mixed with a dye-coated magnetic metal powder. More desirably, a plastic is mixed with a magnetic metal powder which is surface-coated first with a dye and then surface-treated with a silicone oil. The magnetic metal powders used are chiefly rare earth-cobalt magnetic metal powders and include those comprising a rare earth element and cobalt and those comprising a rare earth element, cobalt, copper, and a transition metal element. The amount of the dye used in the coating is preferably 0.02-2wt%, based on magnetic metal powder. The amount of the silicon oil used in the surface treatment is preferably 0.02-2wt%, based on the magnetic metal powder.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved plastic magnet composition, and more particularly to a plastic magnet composition comprising dye-coated magnetic metal powder and plastic.

Traditionally known sintered magnets and cast magnets are difficult to process into complex shapes, and when precision machining is required, they inevitably lead to high costs. It is difficult to obtain a product with a good magnetic distribution, and it is difficult to integrally mold it with other parts. Even if an attempt is made to manufacture a radial anisotropic or multipolar anisotropic magnet, there are problems such as damage and manufacturing difficulty. Plastic magnets were developed to solve the problem of intercrystalline points, and instead of ferrite-based magnetic materials, which were initially used as magnetic materials, due to the demand for stronger, smaller, and lighter materials, rare-earth cobalt-based magnets have recently been used. Metal magnetic materials such as are now being used.

However, in manufacturing such plastic magnets,
When magnetic metal powder such as rare earth cobalt is used as a magnetic material, although it originally has high magnetic properties, it rapidly oxidizes in air at temperatures above 200 to 250°C and loses its magnetic properties. However, it has the disadvantage that it can cause a significant drop in the temperature and may catch fire during molding, so it is mixed with plastic and heated and melted to form it (injection molding
(extrusion molding, etc.), it was necessary to take the following measures.

(1) Use an inert gas atmosphere. This prevents the rare earth cobalt magnetic powder from oxidizing to some extent, but
However, it is incomplete, which inevitably leads to decreased productivity and increased costs.

(2) Rare earth cobalt magnetic powder is coated with a titanium or silane surface treatment agent in advance.

This coating treatment C2 suppresses sudden oxidation to some extent, but it is incomplete, and in particular, the oxidation suppressing ability is hardly exhibited at temperatures above 300°C.

(3) Select and use plastics with relatively low flow temperatures. According to this, the molding temperature can be lowered accordingly, and the progress of oxidation is also suppressed, but
On the other hand, as a matter of course, the resulting plastic magnet has the drawbacks of a low In degree and a large change in magnetic properties (performance) over time.

(4) Lower the time required to fill plastic with magnetic powder.

However, in that case, a high-performance magnet cannot be obtained due to the low amount of light*.

The inventors of the present invention have conducted intensive research in view of such technical problems, and have found that by coating magnetic metal powder mixed with plastic with a dye, it is possible to further coat the magnetic metal powder mixed with plastic with silicone oil. The present invention was completed after confirming that by surface treatment with , air oxidation at high temperatures is almost completely prevented, magnetic properties are not deteriorated, and the following two advantages are provided.

(1) Magnetic metal powder coated with the above-mentioned method will not undergo oxidative deterioration or catch fire even if it comes into contact with sudden air at high temperatures (over 300°C) during molding. A plastic magnet with high magnetic properties can be obtained.

(2) Even if special engineering plastics such as polyphenylene thylphide resin and polyphenylene oxide resin, which require high-temperature molding, are used, high-filling molded products of magnetic metal powder can be injection molded and extruded without any inconvenience. It can be easily obtained by forming means such as molding. This plastic magnet can withstand use under high temperatures, and its magnetic properties do not change (degrade) over time, making it highly reliable.

(3) A plastic magnet with high performance radial anisotropy and radial multipolarity can be obtained.

(4) Integral molding is simple, the complex shape C2 can be easily molded, and the cost required for post-processing is significantly reduced.

(5) The obtained plastic magnet exhibits excellent magnetic performance and has high impact resistance, so it can be used as a relay,
It is advantageous for use in buzzers, etc.

(6) As mentioned above, even when molded at high temperatures, it does not undergo oxidative transformation and does not cause ignition, so safety is ensured in the production process, and it can be recycled and used without deteriorating performance. do not have.

The present invention will be explained in detail below.

The magnetic metal powder targeted by the present invention is mainly rare earth cobalt-based magnetic metal powder, which contains rare earth elements, such as R
Examples include those having a composition represented by Oos or R(CoOuFeM)2. Here, R is one kind or a combination of 2N or more of rare earth elements such as 8m and Ce, and M is one kind or a combination of two or more elements belonging to Groups ■, V, ■, and ■ of the periodic table. , which includes T1, Zn, H
f, V, Nb, Ta, Mo, Or.

Examples include W and Mn. 2 is generally a number from 5 to 9.

In the case of RCos, the particle density as magnetic metal powder is preferably 10 μm or less and about 0.1 μm. If it is larger than 10 Itm, not only the coercive force tends to be small, but also the variation in magnetic properties becomes large. When f″- is less than 0.1 μm, the activity as a powder becomes strong and it tends to become unstable in handling. R (CoCuFe M ) type two-phase separated magnets are either single-crystalized or polycrystalline when the alloy is manufactured. The alloy is pulverized, magnetically formed, sintered, and aged to produce a large amount of magnetic force, which is then pulverized and used as raw material for plastic magnets.
Ru. At this time, restrictions on particle size may be taken into consideration only from the viewpoint of use and handling during molding. For example, for back filling, a mixture of fine powder and slightly larger intergranular powder may be used, or a multi-pole radial π-directional magnet (two is an I of 10 of the pole size) is used.
It is preferable to use powder with a sufficiently small particle size under J2I.

On the other hand, dyes used to coat the magnetic metal powder include direct dyes, acid dyes, basic dyes, mordant dyes, sulfur dyes, vat dyes, disperse dyes, oil-soluble dyes, and reactive dyes. Included are fluorescent brighteners. Specific examples of these are as follows.

Direct dye a, X, Direct Yernia-26, 28, 39, 4
4,50,86,88,89,98,100,C0■,
Direct Orange 39.51, 107, C, I, Direct Red 79.80.81.83.84.89.2
18.C! , I, Direct Green 37.63, C9
Engineering, Direct Violet 47.51.90.94,
C, I, Direct Bruf 1.78.86.90.
98.106.160.194.196.202.22
5.226.246, a, r, direct brown 1.
95.106.170.194.211, C,I.

Direct black 19.32.51.75.94.1
05.106.107.108.113.118.14
6 etc.

Acid dye c, r, acid yellow 7.17.23.25.4
0.44.72.75.98.99.114.131.
141.0. I, Acid Orange 19.45.74.
85.95.0,1. Acid Red 6.32.42.
52.57.75.80, 94.111.114.11
5.118.119.130.131.133.134
．． 145.168.180.184.194.198.
217.249.303, OlI, acid violet 34.47.48, C, engineering, acid blue 15.2
9.43.45.54.59.80.100.102.
113.120.130.140.151.154.1
84.187,229, C, ■, acid green 7.
12.16.20.44.57.0, I, Acid Brown 39.301, C01, Acid Black 1.2.
24.26.29.31.48.52.63.131.
140.155 etc.

Basic dye C,1, Paysic Yellow 11.14.19.21.
28.33.34.35.36, O,1, Paysic Orange 2, I4.15.21.32, C,I, Paysic Red 13.14.18.22.23.24.29.
32.35, 36.37.38% 39.40, C6■,
Paysic Violet 7,]0.15.21.25.
26.27, C9■%ii/ツ'/jn, -9,24
, 54, 58, 60% C, I, Paysic Black 8, etc.

Mordant Dye 0, I, Mordant Yellow 1.23.59, C! , I
.

Mordant Yellow 5, C1■, Mordant Red 21
．． 26.63.89, C8I, Mordant Violet 5, C0 Engineering, Mordand Blue 1.29.47.0, I
, Mordand Guerin 11, C6I, Mordand Brown 1, I4.87, C,1, Mordand Black 1.3
．． 7.9.11.13.17.26.38.54.75
．． 84 etc.

Sulfur dye 0, I, Sulfur orange 1.3, c, I, Sulfur blue 2.3.6.7.9.13, C! , 1. Sulfur Red 3.5.04. Sulfur Green 2.6.
11.14, C, 1, Sulfur Brown 7.8.0,
Engineering, Sulfur Yellow 4, OlI, Sulfur Black 1, O,I, Solbilized Sulfur Orange 3,
C01, Solbilized Sulfur Yellow 2.0, Engineering, Solbilized Sulfur Red 7, c, r.

Solbilized Sulfur Blue-4, C0I, Solbilized Sulfur Green 3, C1,r, Solbilized Sulfur Brown 8, etc.

Vat dye 0, I, vat yellow 2.4.10.20.22.2
3, C, I, Bat Orange 1.2.3.5.13.0
, I, Bat Red 1, Engineering 0.13.16.31.52
, C11, Hat Hiore l-1, 2, 13, C0 ■
, Bat Blue 4.5.6, C, I, Solbilized Bat Blue-6, C, 1, Bat Blue 1.4.29.4
1.64, C0I, Bat Green 1.2.3.8.9
．． 43.44, C, 1, Solbilized Bat Green 1, O, ■, Bat Brown 1.3.22.25.39
．． 41, 44.46, C, 1, Bat Black 9.14
．． 25.57 etc.

fractional dye C,I, Deshens Yellow 1.3.4, C,I.

Dispense thread 12, 80% C, ■, dispense blue 27, etc.

Oil-soluble dye C1I, Solvent Yellow 2.6.14.19.21
．． 33.61.0.1. Solvent Orange 1.5.6
．． 14.37.44.45, C, 1, Solvent Red 1.3.8.23.24.25.27.30149.8
1.82.83, 84.100. -109.121, O
, I, Solvent Violet 1, 8.13.14.2
1.27, O,1, Solvent Blue 2.11.12.
25.35.36.55.73, c, I.

Solvent Clean 1.3, C01, Solvent Brown 3.5.20.37, C01, Solvent Black 3
．． 5.7.22.23.123 etc.

Reactive dye 0.1. Reactive Yellow 1.2.7.17.22
,C,1,Reactive Orange 1.5.7.14,C
, 1:, Reactive Red 3.6.12.0, I, Reactive Blue 2.4.5.7.15.19.04.
Reactive Green 7, C, I, Reactive Black 1, etc.

Fluorescent Brightening Agent C, I, Fluorescent Brightening Agent 2
4.84.85.91.162.163.164.16
7.169.172.174.175.176 etc.

The present invention involves dissolving one or more of the dyes exemplified above in a suitable solvent at approximately 0.01 to 5% by weight to form a coating solution, and using this coating solution to immerse the target magnetic metal powder. The coating treatment is carried out by spraying this treatment liquid onto the surface of the magnetic metal powder, and then heating and drying the powder at a temperature ranging from room temperature to about 150°C.

Solvents for dissolving the dye include alcohol solvents, aliphatic hydrocarbon series solvents, aromatic hydrocarbon thread solvents, halogenated hydrocarbon series solvents, ketone solvents, -ether solvents, ester solvents, and Water is exemplified, and one or more of these are used as a mixed solvent.

The amount of coating dye is 0.02 to the magnetic metal powder.
~2% by weight (preferably 0.05-1% by weight)=j? 4 is desirable. If the amount of coating is too small, the anti-oxidation ability will deteriorate, while if it is too large, not only will the cost be high, but the ratio of plastic as a binder will be relatively reduced, so it will also affect the flowability of magnetic metal powder. This will impede high filling. As will be described later, if necessary, surface treatment PI with silicone oil ζ is applied following the dye coating treatment, but in this case, the amount of dye coating can be reduced.

Incidentally, the magnetic metal powder may be surface-treated in advance with a titanium-based or silane-based compound, a silicone compound, or another polymeric compound prior to coating with the above-mentioned dye.

In the present invention, magnetic metal powder is coated with a dye by the method described above, and if necessary, surface treatment can be performed using silicone oil. This silicone oil treatment improves oxidation resistance more than dye coating treatment alone, and provides a lubricity effect during molding. For this purpose (the silicone oil used on the second side is dimethyl silicone oil,
Examples include methylphenyl silicone oil, various other modified silicone oils, and silicone oils such as dimethyl silicone oil that have been added with two oil-prone agents, and these range from low viscosity to relatively high viscosity. Any binary value can be used, but the surface treatment is usually provided as a solution containing two solvents.Any solvent can be used as long as it dissolves silicone oil, but if necessary, It is desirable that the silicone oil be easily removed by volatilization during drying.The concentration of the silicone oil dissolved in the solvent may be approximately 0.01 to 10% by weight.

The surface treatment of the dye-coated magnetic metal powder with silicone oil may be carried out by a dipping method, a spray method, etc., but it is desirable that the drying temperature at that time be approximately 150° C. or lower. The surface treatment amount of silicone oil is 0.02 to 2% by weight (preferably 0.05 to 2% by weight based on magnetic metal powder).
It is desirable to set it to 1w%). If the treatment amount is too small, the effect of further improving oxidation resistance will not be recognized, while if it is too large, the compatibility with plastics will decrease, resulting in a high filling of magnetic metal powder.

The plastic magnet composition according to the present invention is obtained by mixing the above-mentioned coated magnetic metal powder and plastic, and the plastic used here is generally a thermoplastic, and this C: are polyethylene, polypropylene, polystyrene,
In addition to general thermoplastic plastics such as polyvinyl chloride and acrylate resins, so-called engineering plastics such as nylon, polysulfone resin, polyphenylene sulfide resin, and polyphenylene oxide resin are exemplified. These are merely examples, and the present invention is not limited thereto.

According to the present invention, a plastic borosilicate composite with extremely high magnetic metal powder content? However, it is possible to increase the magnetic metal powder content in the composition to a maximum of about 95% by weight. In this regard, in the past, it was difficult to increase the packing density of magnetic metal powder from the viewpoint of moldability and f-polishing orientation, and therefore it was not possible to obtain a plastic magnet with excellent properties. Note that as the content of magnetic metal powder in the composition decreases, the sharpening properties deteriorate accordingly, so it is preferable that this content does not become less than about 8 to 10% by weight.

The molding method for obtaining the plastic magnet may be any conventionally known method such as injection molding, extrusion molding, compression molding, etc., and the molding method itself is not limited.

According to the present invention, there is no need to use inert gas for long-term storage of magnetic metal powder, it is easy to handle because it is not affected by the oxidation effect of air, and it can be easily handled even when it comes into contact with air at high temperatures during molding. The following advantages are provided: oxidative deterioration, ignition, etc. do not occur, the quality is stable, the yield is improved, and the resulting plastic magnet does not change over time and has a long product life. Therefore, according to the present invention, rare earth cobalt plastic magnets and plastic grinding stones made of alloy saltpeter can be manufactured with high performance.

Next, reference examples and examples will be given.

Rare earth cobalt magnetic metal powder SE in a weighing bottle of about 20 pcs.
REMR-22 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd., particle size: 2μ by Fisher method)'&2g was weighed and collected. - Prepare solvent solutions of the various dyes shown in Table 1 (all have a concentration of 0.5% by weight), add a predetermined amount of this to the sample weighed above, and dry it thoroughly to ensure uniformity. Stir until 60 ml.
The sample was dried at 110° C. to remove the solvent, and then heated at 110° C. for 1 hour. The coating amount of the dye was as shown in the table.

In order to examine the oxidation resistance of two dye-coated magnetic metal powder samples C, they were heated at 250°C (2) for 20 minutes in an open state in a blower-type 7JIJ heat furnace. The results were shown in Table S1.

w2-W.

Wl - Weight of weighing bottle w2 = Weight of weighing bottle + sample W3 = Size after inverting and heating at 110°C for 1 hour W4 = Weight after heating at 250°C for 20 minutes From the results in Table 1 As can be seen, the weight increase due to oxidation was large in the case of the sample that was not subjected to the dye coating treatment, whereas the weight increase was small in the sample treated with the dye coating treatment.
The effect of imparting oxidation resistance by the dye coating film is great.

In addition, as shown in the same table, silane coupling agents (*1) and titanium-based coupling agents (*2), which are conventionally used as surface treatment agents for inorganic materials in plastic-inorganic composites, were selected and studied. However, it was found that the weight increase rate due to oxidation during high-temperature heating was large and the anti-oxidation effect was small.Furthermore, compared with epoxy coating (*3) as a conventional resin coating method, Although this was considered as an example, the rate of increase in heavy electric charge due to oxidation during high-temperature heating was large, and the effect was incomparably worse than that of the present invention.

(*1) Nran KBM603: (manufactured by Gietsu Chemical Industry)
*2) Tetane) KR-TTS: Ajinomoto ((□□
Made by □ (*3) Made by Shell Chemical Co., Ltd., Epicoat 828 (
3%) + Cemedine O (2%), cured at 150°C for 1 hour = 1 Example 1 Beaker C of 11 di-rare earth cobalt-based magnetic metal powder SER
EMR-28 (product name of Shin-Etsu Chemical Co., Ltd.) was weighed at IKp, and a 0.5% (by weight) toluene solution of the dye shown in Table 2 was added to it so that the coating amount was as shown in the table, and stirred well. After mixing, if necessary, toluene was added to moisten the whole, followed by drying at 60° C. to volatilize the solvent, and further heat treatment at 110° C. for 1 hour.

Magnetic powder 435I coated with the dye in this way and UBE nylon 12P-3014U (manufactured by Ube Industries, Ltd.) 65.9 were weighed into a beaker No. 11, stirred at room temperature, and then heated using an 8-3000H manufactured by Gravender with a jacket temperature of 200°C. Granulation was carried out by stirring with a mold mixer (two types).

In addition, experiment 48, /I69.1610, %1 in Table 2
1'M and A613 were prepared by adding a 1% toluene solution of various silicone oils to the dye-coated magnetic metal powder, allowing the metal body to absorb moisture, and drying at 110° C. for 30 minutes. Furthermore, A2 shows the case where only silicone curve treatment was applied without dye coating.

This granulated product is processed using Tanabe Kowagyo Co., Ltd.'s fission field injection molding machine TL.
-50MGS was used to measure the ignitability by injection into the air and the magnetic properties of the f2 molded product.

The results were as shown in Table 2.

Injection molding conditions: V cylinder temperature 1 length (from hopper side) 0
1 = 210℃, 02 = 300℃, nozzle temperature 290℃
, mold temperature 110℃, screw rotation speed 300 rpm
()1! (Settings at load), distributed magnetic field 21 koe From the results in Table 2, if no surface coating treatment was performed, C2 would ignite instantaneously (2) when injected into the air, but if C2 was coated with dye, It was found that significant oxidation resistance was imparted and ignition phenomena were suppressed.

Furthermore, when the surface was treated with silicone oil in addition to the dye coating, a strange load (screw rotation increased by ζ2) and the same squareness as above were observed.

As for the silicone oil, I used fertilized silicone oil.

Oi/Licone oil KF96: (trade name manufactured by iiM Kagaku Kogyo, dimethyl silicone oil ov'J corn oil K P 3s s: manufactured by Shin-Etsu Chemical Co., Ltd. Trade name, modified silicone oil Example 2 In the same manner as in Example 1 Rare Dogan Cobalt-based Magnetic Metal Powder S
The surface of EREM R-28 was coated with heat dye and silicone oil. Seven magnetic metal powders and UBE nylon 12
P-3014U was blended with T composition shown in Table 3, and stirred, granulated, and molded under the same conditions as the experimenter.

The results were as shown in Table 3. With conventional technology, filling @1 piece of magnetic metal powder costs 87 times! However, in the present invention, it was possible to increase the amount %C2 by 94%, and therefore the magnetic properties were significantly improved.

Example 3 Rare earth cobalt-based magnetic metal powder 8E8REM R-30 (
The surface of Shin-Etsu Chemical Co., Ltd. (trade name) was coated with 0.1% by weight of C2, C2■ and Solvent Black 7 in the same manner as in Example 1, and further surface treated with 0.5% by weight of silicone oil KP358. . This surface-treated magnetic metal powder and UBE nylon 12P-3014U were mixed at a ratio of 94% by weight of the former to 6% by weight of the latter, and stirred and granulated using the same method as in Example 2.

This granulated product was subjected to magnetic field molding using a magnetic field injection molding machine manufactured by Tanabe Kogyo Co., Ltd., and a portion of the granulated product was χ-pulverized and molded again. This operation was repeated. The changes in magnetic field characteristics at that time were measured and were as shown in Table 4 (Experiments A621-25)
.

In addition, the same table shows surface-untreated SEREM R-30.
Data are also shown for the case of filling and blending at 7% by weight and for the case of molding once recycled (Experiment A626 and Fu27).

As is clear from Table 4, 1 nutrient, 1 raw metal, 10,000 powders; if the surface is untreated, it is recycled once (Real 1.T, Moxibustion A 271
The magnetic properties deteriorate significantly. Even if I (
The angle 11 is said to represent the degree of deterioration of magnetic metal powder.
'> The strength of the ball decreases from 0.87 to 0.81, in the case of the present invention O) (Experimental Situations 21 to 25) Rikihyon et al. 0.8
5i Mr. Futaba's death is due to O], and the extent of this is slight.

Table 4 Example 4 Average particle size 2 μm and average particle size 4 by Fisher method
011m magnetic metal powder sEREM R-30v2:
The mixture was coated with 0.1% by weight of αL Solvent Black 7 in the same manner as in Example 1, and further surface-treated with 0.4% by weight of silicone oil KP358. This surface-treated magnetic metal powder and polyphenylene thylphide resin (using PP8P-4 manufactured by Philips Corporation) were mixed at a ratio of 91% by weight of the former to 9% by weight of the latter. Injection molding machine TL-50MG + 01 = 2 (10℃, C2 =
330 to 360℃, N (nozzle) = 330 to 360℃,
Molding was carried out at a mold temperature of 130° C. and a screw rotation of zsorpm.

The magnetic field application conditions for orientation are 15koe (60K
TA)X10 seconds.

As a result, Er=5.8kG, iH+c=7.0 ko
e.

BHII]ax=7.2MGOe fj'j
A good shaped product was obtained. Further, no ignition occurred during molding.

Patent applicant: 4M Etsu Kagaku W Co., Ltd.

Claims (1)

[Claims] 1. Plastic magnet composition comprising dye-coated magnetic metal powder and plastic 2. Plastic magnet composition 3 according to claim 1, wherein the magnetic metal powder is rare earth cobalt-based magnetic metal powder. , wherein the plastic is a nylon resin or a polyphenylene thylphide resin.Plastic magnet composition 4 according to claim 1, wherein the amount of the dye coated on the magnetic metal powder is 0.02 to 2% by weight. A plastic magnet composition 5 according to claim 1, wherein the content of the dye-coated magnetic metal powder is 8 to 95% by weight.Plastic magnet composition 6 according to claim 1, the surface of which is coated with a dye. Plastic magnet composition 7 consisting of magnetic metal powder and plastic surface-treated with silicone oil, the amount of surface treatment of silicone oil with respect to the magnetic metal powder is 0
．． The plastic magnet composition according to claim 6, which has a content of 0.02% to 2%.