JPH0757691B2 - Magnetic powder for plastic or rubber magnet and method for producing the same - Google Patents
Magnetic powder for plastic or rubber magnet and method for producing the sameInfo
- Publication number
- JPH0757691B2 JPH0757691B2 JP61220299A JP22029986A JPH0757691B2 JP H0757691 B2 JPH0757691 B2 JP H0757691B2 JP 61220299 A JP61220299 A JP 61220299A JP 22029986 A JP22029986 A JP 22029986A JP H0757691 B2 JPH0757691 B2 JP H0757691B2
- Authority
- JP
- Japan
- Prior art keywords
- magnetic powder
- ferrite
- plastic
- carbon
- powder
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 239000006247 magnetic powder Substances 0.000 title claims description 36
- 239000004033 plastic Substances 0.000 title claims description 32
- 229920003023 plastic Polymers 0.000 title claims description 32
- 238000004519 manufacturing process Methods 0.000 title claims description 6
- 229910000859 α-Fe Inorganic materials 0.000 claims description 31
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 30
- 229910052799 carbon Inorganic materials 0.000 claims description 21
- 239000011230 binding agent Substances 0.000 claims description 12
- 239000011248 coating agent Substances 0.000 claims description 12
- 238000000576 coating method Methods 0.000 claims description 12
- 238000010304 firing Methods 0.000 claims description 9
- 239000000203 mixture Substances 0.000 claims description 7
- 239000002245 particle Substances 0.000 claims description 7
- 125000004432 carbon atom Chemical group C* 0.000 claims description 5
- 230000001590 oxidative effect Effects 0.000 claims description 4
- 239000011261 inert gas Substances 0.000 claims description 3
- 238000010298 pulverizing process Methods 0.000 claims description 2
- 239000002994 raw material Substances 0.000 description 9
- 239000004677 Nylon Substances 0.000 description 3
- 238000001816 cooling Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 229920001778 nylon Polymers 0.000 description 3
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 2
- 239000004372 Polyvinyl alcohol Substances 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 239000013590 bulk material Substances 0.000 description 2
- 238000005336 cracking Methods 0.000 description 2
- 238000000280 densification Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 229920002451 polyvinyl alcohol Polymers 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 235000011187 glycerol Nutrition 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 238000001746 injection moulding Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Compounds Of Iron (AREA)
- Hard Magnetic Materials (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 プラスチツク又はゴム磁石を作る時に使用するフエライ
ト磁性粉及びその製造方法に関する。DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a ferrite magnetic powder used for producing plastic or rubber magnets and a method for producing the same.
従来のBaフエライト又はSrフエライトのプラスチツク磁
石は次の（１）〜（６）の工程を含んで製造されてい
る。A conventional Ba-ferrite or Sr-ferrite plastic magnet is manufactured by including the following steps (1) to (6).
（１） BaCO3あるいはSrCO3と、FeCO3とを所定の比率
に秤量する。(1) Weigh BaCO 3 or SrCO 3 and FeCO 3 in a predetermined ratio.
（２） 上記材料粉末を湿式混合し、脱水、乾燥して、
塊状原料を得る。(2) The above material powders are wet mixed, dehydrated and dried,
Obtain a bulk material.
（３） 得られた塊状原料を２〜3mmに解砕する。(3) Crush the obtained bulk material to 2-3 mm.
（４） 得られた解砕物を大気中、1150〜1300℃で焼成
する。(4) The obtained crushed product is fired in the air at 1150 to 1300 ° C.
（５） 得られた焼成済み材料を衝撃式微粉砕機により
粉砕する。(5) The fired material obtained is crushed by an impact type fine crusher.
（６） 得られた粉末とナイロンとを混合し、磁場中で
射出成形する。(6) The obtained powder and nylon are mixed and injection molded in a magnetic field.
プラスチツク磁石の最大エネルギー積は、焼結磁石の約
50％程度しか得られないので、最大エネルギー積を向上
させるためにはプラスチツク磁石中の磁性粉の含有率
（vol％）を高める必要がある。しかしながら、従来のB
aフエライトあるいはSrフエライト等の磁性粉を用いた
プラスチツク磁石では、最大エネルギー積を向上させる
ために磁性粉の含有率を大きくすると、加圧成形で得ら
れたプラスチツク磁石成形体を熱処理で硬化させる際に
クラツクが発生しやすく、製品歩留まりが著しく低かつ
た。このため実用上、BaフエライトあるいはSrフエライ
ト等の磁性粉の含有率は60vol％以下に制限され、最大
エネルギー積の高いプラスチツク磁石を得ることは困難
であつた。The maximum energy product of plastic magnets is about that of sintered magnets.
Since only about 50% can be obtained, it is necessary to increase the content rate (vol%) of the magnetic powder in the plastic magnet in order to improve the maximum energy product. However, conventional B
In a plastic magnet using magnetic powder such as a ferrite or Sr ferrite, if the content of the magnetic powder is increased in order to improve the maximum energy product, the plastic magnet obtained by pressure molding will be hardened by heat treatment. Cracks tended to occur, and the product yield was extremely low. Therefore, practically, the content of magnetic powder such as Ba ferrite or Sr ferrite was limited to 60 vol% or less, and it was difficult to obtain a plastic magnet with a high maximum energy product.
そこで、本願の第１番目の発明の目的は、プラスチツク
又はゴムに対する結合力が大きいフエライト磁性粉を提
供することにある。Therefore, an object of the first invention of the present application is to provide a ferrite magnetic powder having a large binding force to plastics or rubber.
本願の第２番目の発明は、プラスチツク又はゴムに対す
る結合力の大きいフエライト磁性粉を容易に得ることが
できる製造方法を提供することにある。A second invention of the present application is to provide a manufacturing method capable of easily obtaining a ferrite magnetic powder having a large binding force to plastic or rubber.
上記問題点を解決し、上記目的を達成するための本願の
第１番目の発明に係わるプラスチツク又はゴム磁石用磁
性粉は、フエライト磁性粉の表面に炭素（カーボン）被
膜又は粒子を有することを特徴とするものである。The magnetic powder for plastics or rubber magnets according to the first invention of the present application for solving the above problems and achieving the above object is characterized in that the surface of the ferrite magnetic powder has a carbon coating or particles. It is what
本願の第２番目の発明は、BaCO3又はSrCO3とFe2O3と炭
素原子を含む有機バインダ及び／又は炭素粉末の混合物
を得る工程と、前記混合物を不活性ガス雰囲気中で焼成
し、その後酸化性雰囲気中で冷却させる工程と、前記焼
成で得られた物を粉砕し、炭素被膜又は炭素粒子を表面
に有するフエライト磁性粉を得る工程とを含むことを特
徴とするプラスチツク又はゴム磁石用磁性粉の製造方法
に係わるものである。A second invention of the present application is a step of obtaining a mixture of BaCO 3 or SrCO 3 , Fe 2 O 3 , an organic binder containing carbon atoms and / or carbon powder, and firing the mixture in an inert gas atmosphere, A plastic or rubber magnet characterized by including a step of cooling in an oxidizing atmosphere and a step of pulverizing the product obtained by the firing to obtain a ferrite magnetic powder having a carbon coating or carbon particles on the surface. The present invention relates to a method for producing magnetic powder.
本願の第１及び第２の発明に係わる炭素被膜又は粒子
は、磁性粉とプラスチツク又はゴムとの間に介在して両
者を強固に結合させるために寄与する。The carbon coating or particles according to the first and second inventions of the present application serve to intervene between the magnetic powder and the plastic or the rubber to firmly bond the two.
本願の第２番目の発明において、原料中に炭素原子を含
む有機バインダ及び／又は炭素粉末を混入させ、熱処理
を不活性ガス雰囲気中で行うと、炭素の少なくとも一部
が燃えないで残る。その後の冷却期間で酸化性雰囲気に
すれば、フエライト製造時に要求される酸素の供給が可
能になり、目的とするフエライトが得られる。この冷却
期間において炭素が燃えようとするが、温度及び期間を
調整すれば、全部が燃えることはない。焼成前の原料に
有機バインダ及び／又は炭素粉末が混入され、焼成後も
炭素が残つているので、焼成時のフエライト粒子の緻密
化が妨げられ、容易に解砕することができる。In the second invention of the present application, when an organic binder containing carbon atoms and / or carbon powder is mixed in the raw material and the heat treatment is performed in an inert gas atmosphere, at least a part of carbon remains without burning. If an oxidizing atmosphere is set in the subsequent cooling period, the supply of oxygen required during the production of ferrite becomes possible and the desired ferrite can be obtained. Carbon tries to burn during this cooling period, but if the temperature and period are adjusted, not all will burn. Since the organic binder and / or carbon powder is mixed in the raw material before firing, and the carbon remains after firing, densification of the ferrite particles during firing is hindered and can be easily crushed.
次に、本発明に実施例に係わるフエライト磁性粉及びこ
れを使用したプラスチツク磁石を説明する。Next, the ferrite magnetic powder according to the embodiment of the present invention and the plastic magnet using the same will be described.
（実施例１） まず、BaCO3を19.73gとFe2O3を95.81gと炭素原子を含む
有機バインダとしてのポリビニルアルコール７％水溶液
10gとを秤量し、これ等をボールミルにて混合し、乾燥
器内で水分を除去し、塊状原料混合物を得た。(Example 1) First, 7% aqueous solution of polyvinyl alcohol as an organic binder containing 19.73 g of BaCO 3 and 95.81 g of Fe 2 O 3 and carbon atoms.
10 g was weighed and mixed with a ball mill to remove water in a dryer to obtain a lumped raw material mixture.
次に、この塊状原料混合物を２〜3mmに解砕した。Next, this massive raw material mixture was crushed to 2-3 mm.
次に、解砕した原料混合物をN2ガ雰囲気中で1200℃、２
時間焼成し、しかる後、大気中（酸化性雰囲気中）で冷
却した。Next, 1200 ° C. The pulverized raw material mixture in an N 2 gas atmosphere, 2
It was fired for an hour and then cooled in the air (in an oxidizing atmosphere).
次に、上記焼成によつて得られた物をプラスチツク玉石
を用いるボールミルで24時間湿式粉砕して、第１図に示
す如くフエライト磁性粉（１）の表面に炭素被膜（２）
を有するプラスチツク磁石用磁性粉を得た。なお、有機
バインダ中の炭素によつて焼成時のフエライトの緻密化
が妨げられるので、従来に比べて容易に解砕することが
できる。Next, the product obtained by the above-mentioned firing is wet pulverized for 24 hours by a ball mill using plastic boulders, and a carbon coating (2) is formed on the surface of the ferrite magnetic powder (1) as shown in FIG.
Magnetic powder for plastic magnet having Since carbon in the organic binder hinders densification of the ferrite during firing, it can be crushed more easily than before.
次に、プラスチツク磁石を得るために、射出成形物にお
ける磁性粉の含有率が表で示す如く種々の値（50、60、
70、80vol％）となるように炭素被膜（２）を有するフ
エライト磁性粉（１）とナイロンとを混合し、磁場中で
射出成形を行い、第２図に原理的に示すようなプラスチ
ツク磁石を得た。なお、各磁性粉含有率において50個の
試料（プラスチツク磁石）を作つた。Next, in order to obtain a plastic magnet, the content ratio of the magnetic powder in the injection-molded product was set to various values (50, 60,
70%, 80% by volume) Ferrite magnetic powder (1) having carbon coating (2) is mixed with nylon, injection molding is performed in a magnetic field, and a plastic magnet as shown in principle in FIG. 2 is obtained. Obtained. Note that 50 samples (plastic magnets) were made at each magnetic powder content.
しかる後、各磁性粉含有率のプラスチツク磁石のクラツ
クの発生率（％）を調べたところ、表に示す通りであつ
た。この結果から明らかな如く、磁性粉を70vol％混入
させてもクラツクが発生しない。After that, the crack occurrence rate (%) of the plastic magnet having each magnetic powder content was examined, and it was as shown in the table. As is clear from this result, cracking does not occur even if 70 vol% of magnetic powder is mixed.
比較のために、ポリビニルアルコールに基づく炭素被膜
（２）を設けない磁性粉を実施例１と同一の方法で作
り、実施例１と同一の方法でBaフエライト、Srフエライ
トのプラスチツク磁石を作り、クラツクの発生を調べた
ところ、表の従来例の欄に示す結果となつた。実施例１
と従来例との比較から明らかな如く、従来例ではBaフエ
ライトのプラスチツク磁石、Srフエライトのプラスチツ
ク磁石の両方において磁性粉含有率70vol％からクラツ
クの発生が見られるが、本発明に係わる実施例１では80
vol％まではクラツクの発生が見られない。従つて、本
発明の磁性粉を使用すると、この含有率を多くしてプラ
スチツク磁石の最大エネルギー積を向上させることが可
能になる。For comparison, a magnetic powder not provided with the polyvinyl alcohol-based carbon coating (2) was prepared in the same manner as in Example 1, and Ba ferrite and Sr ferrite plastic magnets were prepared in the same manner as in Example 1 and cracked. When the occurrence of is examined, the results are shown in the column of the conventional example in the table. Example 1
As is clear from the comparison between the conventional example and the conventional example, cracking was observed in both the Ba ferrite plastic magnet and the Sr ferrite plastic magnet from the magnetic powder content of 70 vol%. Then 80
No cracks are seen up to vol%. Therefore, when the magnetic powder of the present invention is used, it is possible to increase the content rate and improve the maximum energy product of the plastic magnet.
（実施例２） Srフエライトのプラスチツク磁石にも本発明を適用する
ことができることを確かめるために、SrCO3を14.76gとF
e2O3を95.81g、炭素原子を含む有機バインダとしてグリ
セリン20重量％水溶液20gとを秤量し、実施例１と同様
な処理を施してSrフエライト磁性粉を得た。 (Example 2) In order to confirm that the present invention can also be applied to the plastic magnet of Sr ferrite, SrCO 3 of 14.76 g and F
95.81 g of e 2 O 3 and 20 g of a 20% by weight aqueous solution of glycerin as an organic binder containing carbon atoms were weighed, and the same treatment as in Example 1 was performed to obtain Sr ferrite magnetic powder.
この磁性粉を使用して実施例１と同一の方法でプラスチ
ツク磁石を作り、クラツクの発生率を調べたところ、表
に示す結果が得られた。この結果から明らかな如く、Sr
フエライトのプラスチツク磁石であつても、Baフエライ
トのプラスチツク磁石と同一の作用効果を得ることがで
きる。Using this magnetic powder, a plastic magnet was made in the same manner as in Example 1 and the incidence of cracks was examined. The results shown in the table were obtained. As is clear from this result, Sr
Even with a ferrite magnetic magnet, it is possible to obtain the same effects as those of a Ba ferrite plastic magnet.
本発明は、上述の実施例に限定されるものでなく、変形
可能なものである。例えば、フエライト原料に有機バイ
ンダの代りに炭素粉末、又は有機バインダと炭素粉末と
の両方を混合してもよい。また、フエライト原料に加え
る有機バインダ及び／又は炭素粉末の量は、フエライト
原料に対して炭素として0.01〜５重量％の範囲が好まし
いことが確認されている。0.01重量％未満になると、炭
素被膜の効果が明らかには判別できなくなり、５重量％
を越えると、磁性粉に固着されない炭素が存在するよう
になり、成形性が悪化する。The present invention is not limited to the above embodiments, but can be modified. For example, carbon powder may be mixed with the ferrite raw material instead of the organic binder, or both the organic binder and the carbon powder may be mixed. It has been confirmed that the amount of the organic binder and / or carbon powder added to the ferrite raw material is preferably in the range of 0.01 to 5% by weight as carbon based on the ferrite raw material. If it is less than 0.01% by weight, the effect of the carbon coating cannot be clearly discerned, and it is 5% by weight.
When it exceeds, the carbon that is not fixed to the magnetic powder comes to exist, and the moldability deteriorates.
上述から明らかな如く、本願の第１番目及び第２番目の
発明によれば、プラスチツク又はゴムに対する結合力の
強い磁性粉を提供することができる。従つて、磁性粉の
含有率を高めてもプラスチツク又はゴム磁石のクラツク
が発生しにくくなり、最大エネルギー積の向上が可能に
なる。As is clear from the above, according to the first and second inventions of the present application, it is possible to provide magnetic powder having a strong binding force to plastic or rubber. Therefore, even if the content ratio of the magnetic powder is increased, the plastic or the crack of the rubber magnet is less likely to occur, and the maximum energy product can be improved.
また、本願の第２番目の発明によれば、原料の焼成前に
有機バインダ及び／又は炭素粉末を加えるので、磁性粉
の表面に強く固着した炭素被膜又は粒子を容易に得るこ
とができる。また、有機バインダ及び／又は炭素粉末を
加えることにより、焼成物を従来のような強い機械的粉
砕方法によらずに容易に解砕することができる。Further, according to the second invention of the present application, since the organic binder and / or the carbon powder is added before firing the raw material, it is possible to easily obtain the carbon coating or particles strongly adhered to the surface of the magnetic powder. Further, by adding the organic binder and / or carbon powder, the fired product can be easily crushed without relying on the conventional strong mechanical crushing method.
第１図は本発明の実施例に従う炭素被膜を有する磁性粉
を原理的に示す断面図、 第２図は本発明の実施例に従うプラスチツク磁石を原理
的に示す断面図である。 （１）……磁性粉、（２）……炭素被膜、（３）……ナ
イロン。FIG. 1 is a sectional view showing in principle a magnetic powder having a carbon coating according to the embodiment of the present invention, and FIG. 2 is a sectional view showing in principle a plastic magnet according to the embodiment of the present invention. (1) ... magnetic powder, (2) ... carbon coating, (3) ... nylon.
Claims (2)
素粒子を固着させたことを特徴とするプラスチツク又は
ゴム磁石用磁性粉。1. A magnetic powder for plastics or rubber magnets, wherein a carbon coating or carbon particles are fixed to the surface of the ferrite magnetic powder.
機バインダ及び／又は炭素粉末との混合物を得る工程
と、 前記混合物を不活性ガス雰囲気中で焼成し、その後酸化
性雰囲気中で冷却させる工程と、 前記焼成で得られた物を粉砕し、炭素被膜又は炭素粒子
で表面に有するフエライト磁性粉を得る工程と を含むことを特徴とするプラスチツク又はゴム磁石磁性
粉の製造方法。2. A step of obtaining a mixture of BaCO 3 or SrCO 3 , FeO 3, and an organic binder containing carbon atoms and / or carbon powder, the mixture being fired in an inert gas atmosphere, and then in an oxidizing atmosphere. And a step of pulverizing the product obtained by the firing to obtain a ferrite magnetic powder having a carbon coating or carbon particles on the surface thereof, a method for producing a plastic or rubber magnet magnetic powder.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61220299A JPH0757691B2 (en) | 1986-09-18 | 1986-09-18 | Magnetic powder for plastic or rubber magnet and method for producing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61220299A JPH0757691B2 (en) | 1986-09-18 | 1986-09-18 | Magnetic powder for plastic or rubber magnet and method for producing the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6374919A JPS6374919A (en) | 1988-04-05 |
| JPH0757691B2 true JPH0757691B2 (en) | 1995-06-21 |
Family
ID=16748980
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61220299A Expired - Lifetime JPH0757691B2 (en) | 1986-09-18 | 1986-09-18 | Magnetic powder for plastic or rubber magnet and method for producing the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0757691B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07297015A (en) * | 1994-04-25 | 1995-11-10 | Fuji Elelctrochem Co Ltd | Oxide magnetic material and method for producing the same |
| CN105753059B (en) * | 2016-03-23 | 2018-06-15 | 上海理工大学 | A kind of preparation method of carbon-based magnesium ferrite composite wave-absorbing film |
-
1986
- 1986-09-18 JP JP61220299A patent/JPH0757691B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6374919A (en) | 1988-04-05 |
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