JP2008106301A - Hollow magnetic spherical body, and method for producing the same - Google Patents
Hollow magnetic spherical body, and method for producing the same Download PDFInfo
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- 230000005291 magnetic effect Effects 0.000 title claims abstract description 63
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 19
- 239000002245 particle Substances 0.000 claims abstract description 42
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims abstract description 7
- 239000011261 inert gas Substances 0.000 claims abstract description 6
- 238000005979 thermal decomposition reaction Methods 0.000 claims abstract description 6
- 239000001257 hydrogen Substances 0.000 claims abstract description 5
- 229910052739 hydrogen Inorganic materials 0.000 claims abstract description 5
- 239000002344 surface layer Substances 0.000 claims abstract description 5
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 4
- 239000001301 oxygen Substances 0.000 claims abstract description 4
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 4
- 239000010419 fine particle Substances 0.000 claims description 24
- 239000007789 gas Substances 0.000 claims description 19
- 229910052742 iron Inorganic materials 0.000 claims description 11
- 229910052759 nickel Inorganic materials 0.000 claims description 11
- 239000000696 magnetic material Substances 0.000 claims description 7
- 229910052761 rare earth metal Inorganic materials 0.000 claims description 7
- 150000002910 rare earth metals Chemical class 0.000 claims description 7
- 229910052788 barium Inorganic materials 0.000 claims description 5
- 229910052804 chromium Inorganic materials 0.000 claims description 5
- 229910052748 manganese Inorganic materials 0.000 claims description 5
- 229910052725 zinc Inorganic materials 0.000 claims description 5
- 239000000126 substance Substances 0.000 claims description 2
- 239000011347 resin Substances 0.000 abstract description 2
- 229920005989 resin Polymers 0.000 abstract description 2
- 239000008246 gaseous mixture Substances 0.000 abstract 1
- 239000006247 magnetic powder Substances 0.000 description 26
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 22
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 15
- 239000002994 raw material Substances 0.000 description 14
- 230000005415 magnetization Effects 0.000 description 13
- 238000000034 method Methods 0.000 description 11
- 239000011257 shell material Substances 0.000 description 9
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 8
- 230000005294 ferromagnetic effect Effects 0.000 description 8
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 7
- 239000000203 mixture Substances 0.000 description 6
- 230000005389 magnetism Effects 0.000 description 5
- BNGXYYYYKUGPPF-UHFFFAOYSA-M (3-methylphenyl)methyl-triphenylphosphanium;chloride Chemical compound [Cl-].CC1=CC=CC(C[P+](C=2C=CC=CC=2)(C=2C=CC=CC=2)C=2C=CC=CC=2)=C1 BNGXYYYYKUGPPF-UHFFFAOYSA-M 0.000 description 4
- 229910052786 argon Inorganic materials 0.000 description 4
- 239000013078 crystal Substances 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 239000007788 liquid Substances 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 239000012159 carrier gas Substances 0.000 description 3
- 238000000354 decomposition reaction Methods 0.000 description 3
- 239000003302 ferromagnetic material Substances 0.000 description 3
- 239000007791 liquid phase Substances 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- KBJMLQFLOWQJNF-UHFFFAOYSA-N nickel(ii) nitrate Chemical compound [Ni+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O KBJMLQFLOWQJNF-UHFFFAOYSA-N 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- 238000001556 precipitation Methods 0.000 description 3
- 239000007921 spray Substances 0.000 description 3
- 239000011701 zinc Substances 0.000 description 3
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 2
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- 229910003310 Ni-Al Inorganic materials 0.000 description 2
- VVTSZOCINPYFDP-UHFFFAOYSA-N [O].[Ar] Chemical compound [O].[Ar] VVTSZOCINPYFDP-UHFFFAOYSA-N 0.000 description 2
- 239000012298 atmosphere Substances 0.000 description 2
- 229910052796 boron Inorganic materials 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 229910001882 dioxygen Inorganic materials 0.000 description 2
- MVFCKEFYUDZOCX-UHFFFAOYSA-N iron(2+);dinitrate Chemical compound [Fe+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O MVFCKEFYUDZOCX-UHFFFAOYSA-N 0.000 description 2
- 239000010410 layer Substances 0.000 description 2
- 238000000634 powder X-ray diffraction Methods 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 239000010453 quartz Substances 0.000 description 2
- 238000006722 reduction reaction Methods 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 238000005211 surface analysis Methods 0.000 description 2
- QTBSBXVTEAMEQO-UHFFFAOYSA-M Acetate Chemical compound CC([O-])=O QTBSBXVTEAMEQO-UHFFFAOYSA-M 0.000 description 1
- CPELXLSAUQHCOX-UHFFFAOYSA-M Bromide Chemical compound [Br-] CPELXLSAUQHCOX-UHFFFAOYSA-M 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- QPLDLSVMHZLSFG-UHFFFAOYSA-N Copper oxide Chemical compound [Cu]=O QPLDLSVMHZLSFG-UHFFFAOYSA-N 0.000 description 1
- 229910002554 Fe(NO3)3·9H2O Inorganic materials 0.000 description 1
- 229910001030 Iron–nickel alloy Inorganic materials 0.000 description 1
- 229910002651 NO3 Inorganic materials 0.000 description 1
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 1
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 description 1
- 229910019142 PO4 Inorganic materials 0.000 description 1
- 229910052772 Samarium Inorganic materials 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- 238000000333 X-ray scattering Methods 0.000 description 1
- 229910001308 Zinc ferrite Inorganic materials 0.000 description 1
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 1
- WNROZLPKEJSTQS-UHFFFAOYSA-N [Fe].[Zn].[Cu].[Ni] Chemical compound [Fe].[Zn].[Cu].[Ni] WNROZLPKEJSTQS-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 239000012300 argon atmosphere Substances 0.000 description 1
- 229910001566 austenite Inorganic materials 0.000 description 1
- 150000001805 chlorine compounds Chemical class 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 230000005307 ferromagnetism Effects 0.000 description 1
- 230000004927 fusion Effects 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 229910052746 lanthanum Inorganic materials 0.000 description 1
- 239000006249 magnetic particle Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000002105 nanoparticle Substances 0.000 description 1
- 229910000480 nickel oxide Inorganic materials 0.000 description 1
- 150000002823 nitrates Chemical class 0.000 description 1
- -1 organic acid salts Chemical class 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- GNRSAWUEBMWBQH-UHFFFAOYSA-N oxonickel Chemical compound [Ni]=O GNRSAWUEBMWBQH-UHFFFAOYSA-N 0.000 description 1
- 239000003002 pH adjusting agent Substances 0.000 description 1
- 230000005298 paramagnetic effect Effects 0.000 description 1
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 1
- 239000010452 phosphate Substances 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 238000003908 quality control method Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000012798 spherical particle Substances 0.000 description 1
- 238000001694 spray drying Methods 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Abstract
Description
本発明は、磁性粉を用いた磁気ヘッドやデジタルビデオテープ、フロッピーデイスク（登録商標）などの磁気記録媒体、また、電子機器から発生する電磁波障害を防止するためのシールド材として用いる磁性粉体に関し、特に直径が10μｍ以下の中空の強磁性球体、及びその製造方法に関するものである。 The present invention relates to a magnetic recording medium such as a magnetic head, a digital video tape, and a floppy disk (registered trademark) using magnetic powder, and a magnetic powder used as a shielding material for preventing electromagnetic interference generated from an electronic device. In particular, the present invention relates to a hollow ferromagnetic sphere having a diameter of 10 μm or less, and a method for producing the same.
磁気記録媒体や電磁波障害を防止するためのシールド材として希土類−遷移金属−ホウ素系、鉄−ニッケル−銅−亜鉛系のフェライト酸化物磁性粉体等が提案され、それぞれ用途に応じた粒径や形状に工夫が凝らされている。 Rare earth-transition metal-boron and iron-nickel-copper-zinc ferrite oxide magnetic powders have been proposed as magnetic recording media and shielding materials for preventing electromagnetic interference. The shape is devised.
例えば、特開2001−181754号公報は、希土類−鉄−ホウ素系の磁性成分を原料溶液から液相沈殿させる方法が開示されている。液相沈殿法の場合、成分毎に沈殿させる物質のpHが異なるため、必ずしも製造された磁性粉の組成が意図した組成にならない。また、攪拌が不十分であると不均一な組成となり、かつ、pH調整剤が必要であるという問題がある。また、沈殿物をろ過、洗浄、焼成した後、水素還元工程が必要であり、コスト高になるという問題がある。 For example, Japanese Patent Application Laid-Open No. 2001-181754 discloses a method for liquid-phase precipitation of a rare earth-iron-boron magnetic component from a raw material solution. In the case of the liquid phase precipitation method, since the pH of the substance to be precipitated is different for each component, the composition of the produced magnetic powder is not necessarily the intended composition. Further, if the stirring is insufficient, there is a problem that the composition becomes non-uniform and a pH adjuster is necessary. In addition, after the precipitate is filtered, washed, and fired, a hydrogen reduction step is necessary, which increases the cost.
複数の磁性粉同士を機械的に混合して焼成するものとして特開2003−282319号公報がある。鉄酸化物粉末、ニッケル酸化物粉末、銅酸化物粉末、亜鉛酸化物粉末を水に懸濁し、スプレードライ法で球状の混合粒子を形成し、これを焼成して目的の酸化物磁性粉を作成している。しかし、この方法では組成成分が多くなると、機械的な混合によるため、均一な組成とすることが難しく、磁性成分の分布が不均一になるという問題がある。 Japanese Patent Laid-Open No. 2003-282319 discloses a technique in which a plurality of magnetic powders are mechanically mixed and fired. Iron oxide powder, nickel oxide powder, copper oxide powder, and zinc oxide powder are suspended in water, and spherical mixed particles are formed by spray drying, which is then fired to produce the desired oxide magnetic powder. is doing. However, this method has a problem that when the composition component is increased, it is difficult to obtain a uniform composition because of mechanical mixing, and the distribution of magnetic components becomes non-uniform.
更に、これらにより製造される磁性粉は、いずれも中空の磁性球体ではなく、本来磁場に関与しない磁性体が球体内に中実され、この結果コスト高になるという問題がある。
そこで本発明の課題は、低コストで均一な中空磁性球体、及びその製造方法を提供することにある。 Therefore, an object of the present invention is to provide a low-cost and uniform hollow magnetic sphere and a method for producing the same.
本発明の中空磁性球体は、平均粒径が10μｍ以下であることを特徴とする。この中空磁性球体は、その磁性体が中空球体の表層又は殻中のいずれかに存在する。中空の殻の表層に存在する磁性成分は、殻材と磁性体との界面にある合金層又は融着層により強固に結合している。 The hollow magnetic sphere of the present invention is characterized in that the average particle size is 10 μm or less. In the hollow magnetic sphere, the magnetic body exists in either the surface layer or the shell of the hollow sphere. The magnetic component present in the surface layer of the hollow shell is firmly bonded by the alloy layer or the fusion layer at the interface between the shell material and the magnetic material.
粒子径は、10μｍからサブミクロンのものまで、供給原料の濃度と液滴の大きさをコントロールすることによって、使用目的に適合した粒子径で且つ粒径分布が狭い粉体が容易に得ることができる。とくに、サブミクロンの中空磁性球体は電波のシールド材として優れた性能を発揮する。 By controlling the concentration of feedstock and droplet size from 10 μm to submicron, it is easy to obtain a powder with a particle size suitable for the purpose of use and a narrow particle size distribution. it can. In particular, submicron hollow magnetic spheres exhibit excellent performance as radio wave shielding materials.
前記磁性体が、Ni、Fe、Coから選ばれた少なくとも1種以上を含む及び/又はNi、Fe、Co、 Ba、Mn、Zn、Cr、希土類から選ばれた少なくとも２種以上を含むことは好適である。
本発明の中空磁性球体の製造方法は、磁性成分が溶解した溶液を微粒子液滴とし、前記微粒子液滴を不活性ガス、又は不活性ガスと水素又は酸素との混合ガスによりプラズマ炎中に導入し、熱分解により生成することを特徴とする。本発明で得られる中空磁性球体は、平均粒径が10μｍ以下で、球体外表面の厚さが数10nｍである。また、球体となる殻の表層に磁性成分が分布していることから、密度が小さく軽量であり、樹脂等との混合性にも優れている。
The magnetic body contains at least one selected from Ni, Fe, Co and / or contains at least two selected from Ni, Fe, Co, Ba, Mn, Zn, Cr, rare earth Is preferred.
In the method for producing a hollow magnetic sphere of the present invention, a solution in which a magnetic component is dissolved is made into fine particle droplets, and the fine particle droplets are introduced into a plasma flame by an inert gas or a mixed gas of an inert gas and hydrogen or oxygen. And produced by thermal decomposition. The hollow magnetic sphere obtained by the present invention has an average particle size of 10 μm or less and a sphere outer surface thickness of several tens of nm. Further, since the magnetic component is distributed on the surface layer of the shell serving as a sphere, the density is small and light, and the mixing property with a resin or the like is excellent.
殻成分及び磁性成分の原料には、水、酸又はアルカリに溶解しやすい硝酸塩、硫酸塩、塩化物又は有機酸塩などのなかから適宜選択すればよい。また、殻成分及び磁性成分の原料溶液は、予め一液にして液滴化するのが好ましいが、混合することが難しい原料液は接近した2本のノズルを用いる衝突型霧発生ノズルによって噴霧し、気流搬送中に合体させてプラズマ炎に供給させてもよい。 The raw materials for the shell component and the magnetic component may be appropriately selected from nitrates, sulfates, chlorides or organic acid salts that are easily dissolved in water, acid or alkali. In addition, it is preferable that the raw material solution of the shell component and the magnetic component is preliminarily formed into one liquid to form droplets, but the raw material liquid that is difficult to mix is sprayed by a collision type fog generating nozzle using two nozzles that are close to each other. Alternatively, they may be united during the air flow conveyance and supplied to the plasma flame.
超音波噴霧器やスプレーノズル方式によって、液滴の平均粒子径を10〜100μｍにコントロールすることは容易であり、このような微粒子液滴は気流によって運ばれやすく、液滴同士が衝突して会合することも少ない。 It is easy to control the average particle size of the droplets to 10-100 μm using an ultrasonic sprayer or a spray nozzle system. Such fine particle droplets are easily carried by the air current, and the droplets collide with each other and associate with each other. There are few things.
また、アルゴンガスを使用することによって、プラズマは安定に維持される。水素ガスの併用は、プラズマ雰囲気を還元性に保持することができ、得られた磁性球体の成分を変えることができる。またフェライトのごとく酸化物で磁性を有する場合は、適宜酸素を加えることが好ましい。アルゴン雰囲気、アルゴン−酸素ガス雰囲気のプラズマ炎中で得られた中空磁性球体をさらに水蒸気を含む水素気流中で加熱還元し、常磁性体である三酸化二鉄を強磁性体の四酸化三鉄に還元する。 Moreover, plasma is maintained stably by using argon gas. The combined use of hydrogen gas can keep the plasma atmosphere reducible and can change the components of the obtained magnetic sphere. Further, when an oxide such as ferrite has magnetism, oxygen is preferably added as appropriate. Hollow magnetic spheres obtained in a plasma flame in an argon atmosphere or an argon-oxygen gas atmosphere are further heated and reduced in a hydrogen stream containing water vapor, and paramagnetic ferric trioxide is converted into a ferromagnetic triiron tetraoxide. To reduce.
前記磁性体が、Ni、Fe、Coから選ばれた少なくとも1種以上を含む及び/又はNi、Fe、Co、 Ba、Mn、Zn、Cr、希土類から選ばれた少なくとも２種以上を含むことは好適であり、また、前記微粒子液滴の平均粒径が100μｍ以下であることは好適である。 The magnetic body contains at least one selected from Ni, Fe, Co and / or contains at least two selected from Ni, Fe, Co, Ba, Mn, Zn, Cr, rare earth It is also preferable that the fine particle droplets have an average particle size of 100 μm or less.
本発明によれば、簡便な製造方法により均一かつ軽量の中空磁性球体を製造することができる。また、磁性材料の使用量を低減でき、低コストな磁性粉体を製造することができる。 According to the present invention, a uniform and lightweight hollow magnetic sphere can be manufactured by a simple manufacturing method. Moreover, the usage-amount of a magnetic material can be reduced and a low-cost magnetic powder can be manufactured.
本発明の実施の形態について図面を参照して説明するが、本発明はこれに限定されるものではない。
図1は本発明で得られる中空磁性球体の概念図を示したものである。本発明により製造される中空磁性球体の平均粒径は10μｍ以下の微細な球体である。また、内部が中空となっている。図1（ａ）は中空形体を構成する殻成分の外表面に均一に磁性成分が分散されている場合である。図1（ｂ）は殻の中に磁性成分が分散されている場合である。図1（ｃ）は殻そのものが磁性成分の場合である。
Embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited thereto.
FIG. 1 is a conceptual diagram of a hollow magnetic sphere obtained by the present invention. The hollow magnetic spheres produced according to the present invention are fine spheres having an average particle size of 10 μm or less. Moreover, the inside is hollow. FIG. 1 (a) shows a case where the magnetic component is uniformly dispersed on the outer surface of the shell component constituting the hollow body. FIG. 1B shows the case where the magnetic component is dispersed in the shell. FIG. 1C shows the case where the shell itself is a magnetic component.
図2は本発明のプラズマ装置を用いた場合の中空磁性球体（以下、中空磁性粉という）の製造装置の概略構成を示した図である。Arガスなどのプラズマを発生するガスをガス導入管1から導入し、流量計3により所定の流量にした後、石英製反応管9内のプラズマ発生部14に導入する。必要に応じてH2などの還元性ガス又はO2などの酸化性ガスを導入管2から導入し流量計4により所定の流量にした後、ガス混合器5で混合する。これらのガスは超音波噴霧器7により磁性成分となる金属塩が溶解している原料溶液8が入っている原料溶液用容器6からの霧状の微粒子液滴16を同伴してプラズマ発生部14に送られる。尚、原料溶液が入っている原料溶液用容器6と超音波噴霧器7は水槽21に設置されている。 FIG. 2 is a diagram showing a schematic configuration of an apparatus for producing a hollow magnetic sphere (hereinafter referred to as hollow magnetic powder) when the plasma apparatus of the present invention is used. A gas that generates plasma, such as Ar gas, is introduced from the gas introduction tube 1, adjusted to a predetermined flow rate by the flow meter 3, and then introduced into the plasma generation unit 14 in the quartz reaction tube 9. If necessary, a reducing gas such as H 2 or an oxidizing gas such as O 2 is introduced from the introduction pipe 2 to obtain a predetermined flow rate by the flow meter 4 and then mixed in the gas mixer 5. These gases are entrained in the plasma generating unit 14 along with the atomized fine particle droplets 16 from the raw material solution container 6 containing the raw material solution 8 in which the metal salt as a magnetic component is dissolved by the ultrasonic atomizer 7. Sent. The raw material solution container 6 containing the raw material solution and the ultrasonic sprayer 7 are installed in the water tank 21.
プラズマ発生部14に送られた微粒子液滴16は、ここで熱分解及び／又は熱分解と還元反応又は酸化反応により、磁性粉18となる。生成した磁性粉18は水が充填されているトラップ容器22内で捕集される。この水は循環ポンプ15でトラップ内を循環されている。得られた磁性粉18はバルブ17を介して取り出し、水洗、乾燥により中空磁性粉を得る。 The fine particle droplets 16 sent to the plasma generating unit 14 become magnetic powder 18 by thermal decomposition and / or thermal decomposition and reduction reaction or oxidation reaction. The produced magnetic powder 18 is collected in a trap container 22 filled with water. This water is circulated in the trap by a circulation pump 15. The obtained magnetic powder 18 is taken out via a valve 17, and washed with water and dried to obtain hollow magnetic powder.
磁性成分を含む原料溶液は、Fe、Co、Niの少なくとも1種以上を含む溶液であることが好ましく、硝酸塩、塩化物、硫酸塩、炭酸塩、酢酸塩、臭化物、リン酸塩、シュウ酸塩などを水に溶解して用いることが好適である。また、磁気特性を向上させるには、Fe、Co、Niの1種以上とBa、Mn、Zn、Crなど酸化物とを組み合わせた酸化物系磁性体及び/又はFe、Co、Niの1種以上とSm、Laなどの希土類を含む希土類磁性体とすることが好適である。このような酸化物系磁性体、希土類磁性体を作成するには、これらを混合液とし、微粒子液滴にしてプラズマ炎中で熱分解することで作成することができる。 The raw material solution containing the magnetic component is preferably a solution containing at least one of Fe, Co, and Ni, and is nitrate, chloride, sulfate, carbonate, acetate, bromide, phosphate, oxalate. It is preferable to use such as dissolved in water. In order to improve the magnetic properties, one or more of Fe, Co, Ni and an oxide-based magnetic material in combination with an oxide such as Ba, Mn, Zn, Cr and / or one of Fe, Co, Ni It is preferable to use a rare earth magnetic material containing rare earth such as Sm and La as described above. In order to prepare such an oxide-based magnetic body and a rare earth magnetic body, they can be prepared by using them as a mixed liquid and making them into fine particle droplets and thermally decomposing them in a plasma flame.
原料溶液を霧状の微粒子液滴にする方法としては、超音波噴霧器、加圧スプレー方式などでよいが、これに限定されるものではない。微粒子液滴の径は、その濃度にも関係するが50μｍ以下が好ましく、望ましくは液滴の径が10μｍ以下であることが適当である。これは50μｍ以上の液滴の場合は生成物が10μｍ以下の微粒子にならないためである。 As a method of making the raw material solution into mist-like fine particle droplets, an ultrasonic sprayer, a pressure spray method, or the like may be used, but the method is not limited thereto. Although the diameter of the fine particle droplet is related to its concentration, it is preferably 50 μm or less, and desirably the droplet diameter is 10 μm or less. This is because in the case of droplets of 50 μm or more, the product does not become fine particles of 10 μm or less.
微粒子液滴をプラズマ発生装置に導入するためのキャリアガスとしてAr及び又はAr-H2、またはAr-O2からなるガスを使用する。キャリアガスは単に噴霧液滴をプラズマ発生部に導入するためだけでなく、プラズマ発生ガスとしての働きをする。即ちArは電離しやすく、安定にプラズマ状態になるので好適である。Arは安定なプラズマ状態にするために必要であるが、分解生成物をより還元状態にする場合には、H2を導入することが望ましい。酸化物が磁性を有する場合はアルゴン−酸素ガスからなるガスを用いることが望ましい。プラズマ源としては、高周波プラズマやマイクロ波プラズマなどがあるが特に限定されない。 A gas composed of Ar and / or Ar—H 2 or Ar—O 2 is used as a carrier gas for introducing fine particle droplets into the plasma generator. The carrier gas serves not only to introduce the spray droplets into the plasma generating part but also as a plasma generating gas. That is, Ar is suitable because it is easily ionized and stably enters a plasma state. Ar is necessary for obtaining a stable plasma state, but it is desirable to introduce H 2 when the decomposition product is more reduced. When the oxide has magnetism, it is desirable to use a gas composed of argon-oxygen gas. Examples of the plasma source include high-frequency plasma and microwave plasma, but are not particularly limited.
本実施例では、大気圧でのマイクロ波プラズマ装置(出力約1kW、2.5GHz)を用いて、Ni―Alを含むプラズマ粒子を製造した。水100ccに硝酸ニッケルNi(NO3)2・6H2Oを4．67g及び硝酸アルミニウムAl(NO3)3・9H2Oを17．7g溶解し、図2に示す原料溶液用容器6に入れた。次いでガス導入管1からアルゴンガスを流量計3で5Ｌ/分に設定して系内に導入した。プラズマ装置の電源を投入しアルゴンプラズマを発生させた。次いで循環ポンプ15の電源を入れ、微粒子トラップ内に水をシャワー方式で滴下するようにした。次いで超音波霧化器7(周波数2.4MHz)の電源を投入し、硝酸ニッケル及び硝酸アルミニウムが溶解した溶液を約3μｍの微粒子液滴とし、プラズマ炎中に導入して熱分解して粒子を製造した。熱分解終了後、微粒子トラップ容器22内に捕集された微粒子をバルブ17を開いて採取し、ろ過、乾燥して微粒子を得た。 In this example, plasma particles containing Ni—Al were produced using a microwave plasma apparatus (output: about 1 kW, 2.5 GHz) at atmospheric pressure. Dissolve 4.67 g of nickel nitrate Ni (NO 3 ) 2 · 6H 2 O and 17.7 g of aluminum nitrate Al (NO 3 ) 3 · 9H 2 O in 100 cc of water and place in the raw material solution container 6 shown in FIG. It was. Subsequently, the argon gas was introduced into the system from the gas introduction pipe 1 with the flow meter 3 set to 5 L / min. The plasma apparatus was turned on to generate argon plasma. Next, the power of the circulation pump 15 was turned on, and water was dropped into the fine particle trap by a shower method. Next, turn on the power of the ultrasonic atomizer 7 (frequency 2.4 MHz), make a solution of nickel nitrate and aluminum nitrate dissolved into about 3 μm fine particle droplets, introduce them into a plasma flame, and thermally decompose to produce particles. did. After completion of the thermal decomposition, the fine particles collected in the fine particle trap container 22 were collected by opening the valve 17, filtered and dried to obtain fine particles.
得られた微粒子の電子顕微鏡による観察結果は次の通りである。図3はNi―Al含有粒子の形状を示した写真である。約5μｍ以下の球状であることが明確に分かる。また図4は図3の粒子中のNiをEDX（蛍光X線散乱）を用いて面分析を行った写真である。Niは粒子全体に分布しているが、球の中心部はNi成分が少ないことが分かる。この分布はAlの分布ともよく対応した。 The observation results of the obtained fine particles with an electron microscope are as follows. FIG. 3 is a photograph showing the shape of Ni—Al-containing particles. It can be clearly seen that the sphere is about 5 μm or less. FIG. 4 is a photograph of Ni in the particles of FIG. 3 subjected to surface analysis using EDX (fluorescence X-ray scattering). Although Ni is distributed throughout the particle, it can be seen that the central part of the sphere has less Ni component. This distribution corresponds well with the distribution of Al.
更に図5はNiの粒子内における分散状態を観察したものであるが、約20nm以下の結晶粒子として均一かつ高密度に分散されていることが分かる。図6はこの粒子を破砕した場合の写真である。破砕することにより球状粒子が壊れた様子が良く分かる。 Further, FIG. 5 is an observation of the dispersion state in the Ni particles, and it can be seen that the particles are uniformly and densely dispersed as crystal particles of about 20 nm or less. FIG. 6 is a photograph when the particles are crushed. It can be clearly seen that the spherical particles are broken by crushing.
破砕片の表面に、均質高分散した約20nm程度のスポットとして見える粒子がNi結晶粒子である。この写真から、図4で球の中心部にNiが少なく見えたのは、Al2O3を殻の主成分とする中空粒子のためであることが分かった。また特徴的なのは、球の内側の表面にはNi結晶粒子は殆んど存在せず、大部分は外側の表面に存在していることが明確に分かる。更にこの粒子を磁石に近づけると強力に吸引され、強磁性体であることが分かった。 Particles that appear as spots of about 20 nm that are homogeneously and highly dispersed on the surface of the crushed pieces are Ni crystal particles. From this photograph, it was found that the reason why Ni was visible in the center of the sphere in FIG. 4 was due to the hollow particles whose main component was Al 2 O 3 . Also, it is clear that there are almost no Ni crystal particles on the inner surface of the sphere, and most exist on the outer surface. Furthermore, when this particle was brought close to the magnet, it was strongly attracted and found to be a ferromagnetic material.
以上の測定結果から、強磁性を持つNiが球の外側表面に密に存在することにより、磁性を持たないAl2O3に混合された場合でも、球全体として強磁性体になるものと思われる。
本結果から明らかなように、磁性成分が含まれている溶液を霧状の微細な液滴にし、該微粒子液滴をArガスをキャリアーガスとしプラズマ炎中に導入することにより10μｍ以下の球状で、その内部が中空である磁性粉を容易に得ることが出来る。該磁性粉は前記したような大きな特徴を有し、磁性体として多くの分野に用いることが可能である。
From the above measurement results, it is believed that Ni with ferromagnetism is densely present on the outer surface of the sphere, so that even when it is mixed with Al 2 O 3 without magnetism, the sphere as a whole becomes a ferromagnet. It is.
As is clear from this result, the solution containing the magnetic component is made into mist-like fine droplets, and the fine particle droplets are introduced into a plasma flame using Ar gas as a carrier gas, and are spherical with a size of 10 μm or less. The magnetic powder having a hollow inside can be easily obtained. The magnetic powder has the great characteristics as described above, and can be used in many fields as a magnetic material.
以上、本発明からなるプラズマ製造法は、球状でその内部が中空体からなる磁性粉を容易に製造できる。本発明の製造法は、工業的にも製造工程が溶液調整、分解、捕集のみであり従来の製造法に比べ大幅に工程を低減させることが出来、低コスト化が可能である。更に液相沈殿法や粒子の混合法に比べ組成の制御が容易でありバラツキが無く、品質管理が容易である。従って大量生産に対しても、工程が少ないので煩雑な装置が不要であり、単純な設備だけで実施可能である。 As mentioned above, the plasma manufacturing method which consists of this invention can manufacture easily the magnetic powder which is spherical and the inside becomes a hollow body. In the manufacturing method of the present invention, the manufacturing process is industrially only solution adjustment, decomposition, and collection, and the process can be greatly reduced as compared with the conventional manufacturing method, and the cost can be reduced. Furthermore, the composition can be easily controlled and there is no variation compared with the liquid phase precipitation method or the particle mixing method, and quality control is easy. Therefore, even for mass production, since the number of processes is small, a complicated apparatus is unnecessary, and it can be implemented with simple equipment.
この粒子を磁石に近づけると強力に吸引され、強磁性体であることが分かった。そこで、強磁性粒子としての性質を更に明確にするため、磁化曲線を測定した。図7は 液体ヘリウム温度5Kにおける磁化曲線を示したものである。磁場をかけることにより磁化され且つヒステリシスを示すことから残留磁場が発生し、強磁性体であることがわかる。又この磁性粒子の飽和磁化は10emu/g以上であることが分かる。 When these particles were brought close to a magnet, they were strongly attracted and found to be ferromagnetic. Therefore, in order to further clarify the properties as ferromagnetic particles, the magnetization curve was measured. Fig. 7 shows the magnetization curve at a liquid helium temperature of 5K. Since it is magnetized by applying a magnetic field and exhibits hysteresis, a residual magnetic field is generated, indicating that it is a ferromagnetic material. It can also be seen that the saturation magnetization of the magnetic particles is 10 emu / g or more.
更に図8には室温(300K)における、磁化曲線を示した。(A)の結果から、5Kの場合と同様に磁場をかけることにより磁化されていることが分かる。飽和磁化は約5emu/gであった。同図の(B)は磁場を拡大した図であり、この図からヒステリシスの存在を確認した。 Further, FIG. 8 shows a magnetization curve at room temperature (300 K). From the result of (A), it can be seen that magnetization is performed by applying a magnetic field as in the case of 5K. The saturation magnetization was about 5 emu / g. (B) in the figure is an enlarged view of the magnetic field, and from this figure, the existence of hysteresis was confirmed.
以上のように、本実施例からなる、粒子は強磁性体であることが確認された。更に粒子の粉末Ｘ線回折を行った結果、磁性を持つ金属状のNiを含むことが分かった。 As described above, it was confirmed that the particles of this example were ferromagnetic. Furthermore, as a result of conducting powder X-ray diffraction of the particles, it was found that metallic Ni containing magnetism was contained.
実施例1と同様にして図2に示すマイクロ波プラズマ装置を用いて、Fe―Alを含むプラズマ粒子を製造した。水100ccに硝酸鉄Fe(NO3)3・9H2Oを2.73ｇ及び硝酸アルミニウム10gを溶解し、実施例1と同様にして製造した。尚、本実施例では、プラズマ炎中に水素ガスをアルゴン中に5％添加した。 Plasma particles containing Fe—Al were produced in the same manner as in Example 1 using the microwave plasma apparatus shown in FIG. In 100 cc of water, 2.73 g of iron nitrate Fe (NO 3 ) 3 · 9H 2 O and 10 g of aluminum nitrate were dissolved and produced in the same manner as in Example 1. In this example, 5% of hydrogen gas was added to argon in the plasma flame.
得られた微粒子は約2μｍであり、磁石に近づけると吸引され、強磁性体であることが分かった。そこでこの粒子についても実施例1と同様に磁化曲線を求めた。その結果、磁場をかけることにより磁化され、飽和磁化は10emu/gであり、ヒステリシスの存在も確認した。粉末Ｘ線回折を行い、結晶構造を調べた結果、磁性を持つγ―Fe2O3を含むことが分かった。 The fine particles obtained were about 2 μm, attracted when approaching the magnet, and were found to be ferromagnetic. Therefore, the magnetization curve of this particle was determined in the same manner as in Example 1. As a result, it was magnetized by applying a magnetic field, the saturation magnetization was 10 emu / g, and the presence of hysteresis was also confirmed. As a result of examining the crystal structure by powder X-ray diffraction, it was found that it contained γ-Fe 2 O 3 having magnetism.
実施例1と同様な方法でNi-Fe-Alからなるプラズマ粒子を製造した。硝酸鉄3.4ｇと硝酸ニッケル2.6ｇ及び硝酸アルミニウム5.0gを水100ccに溶解し、実施例1と同様にして図2に示すマイクロ波プラズマ装置を用いて、Ni-Fe-Alからなる粒子を製造した。 Plasma particles made of Ni—Fe—Al were produced in the same manner as in Example 1. Dissolve 3.4 g of iron nitrate, 2.6 g of nickel nitrate and 5.0 g of aluminum nitrate in 100 cc of water, and manufacture particles made of Ni-Fe-Al using the microwave plasma apparatus shown in FIG. did.
得られた微粒子は約3μｍであり、磁石に近づけると吸引され、強磁性体であることが分かった。そこでこの粒子についても実施例1と同様に磁化曲線を求めた。図9に室温(300K)における結果を示す。同図(A)において、室温でも明らかに磁場をかけることにより磁化され、且つ飽和磁化は約10emu/gであることが分かる。同図の(B)は磁場を拡大したものであり、この図からヒステリシスの存在を確認した。以上のように、本実施例からなる、粒子は強磁性体であることが確認された。 The obtained fine particles were about 3 μm, attracted when approaching the magnet, and were found to be ferromagnetic. Therefore, the magnetization curve of this particle was determined in the same manner as in Example 1. FIG. 9 shows the results at room temperature (300K). In FIG. 5A, it can be seen that the magnetized by applying a magnetic field clearly even at room temperature, and the saturation magnetization is about 10 emu / g. (B) in the figure shows an enlarged magnetic field, and the presence of hysteresis was confirmed from this figure. As described above, it was confirmed that the particles of this example were ferromagnetic.
本発明に係る、球状でその内部が中空体からなる磁性粉及びその製造方法は磁気ヘッドやテープ、フロッピーデイスク（登録商標）などの高密度磁気記録媒体や電子機器から発生する電磁波障害を防止するためのシールド材として用いられる強磁性体材料として極めて有効である。 A magnetic powder having a spherical shape and a hollow body and a method for producing the same according to the present invention prevent electromagnetic interference generated from a high-density magnetic recording medium such as a magnetic head, a tape, and a floppy disk (registered trademark) and an electronic device. Therefore, it is extremely effective as a ferromagnetic material used as a shielding material.
1、2 ガス導入管
3、4 流量計
5 ガス混合器
6 原料溶液用容器
7 超音波霧化器
8 原料溶液
9 石英製反応管
10 ガス出口
11 循環水
12、13 電極
14 プラズマ発生部
15 循環ポンプ
16 微粒子液滴
17 バルブ
18 磁性粉
19 循環水出口
20 遮蔽板
21 水槽
22 微粒子トラップ容器
23 原料タンク
24、26 ポンプ
25 循環水タンク
1, 2 Gas introduction pipe
3, 4 Flow meter
5 Gas mixer
6 Raw material solution container
7 Ultrasonic atomizer
8 Raw material solution
9 Quartz reaction tube
10 Gas outlet
11 Circulating water
12, 13 electrodes
14 Plasma generator
15 Circulation pump
16 Fine particle droplet
17 Valve
18 Magnetic powder
19 Circulating water outlet
20 Shield plate
21 Aquarium
22 Particle trap container
23 Raw material tank
24, 26 pump
25 Circulating water tank
Claims (7)
The method for producing a hollow magnetic sphere according to claim 4, wherein an average particle diameter of the fine particle droplets is 100 μm or less.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010208875A (en) * | 2009-03-09 | 2010-09-24 | Tokyo Institute Of Technology | Magnetic hollow particle and method for producing the same |
| CN109261984A (en) * | 2018-11-23 | 2019-01-25 | 陕西科技大学 | A kind of preparation method of Ni nano-hollow ball |
| US10662316B2 (en) | 2016-03-25 | 2020-05-26 | Fuji Polymer Industries Co., Ltd. | Magneto-rheological elastomer composition, method for producing same, and vibration absorbing device including same |
| US11817245B2 (en) | 2015-07-31 | 2023-11-14 | Murata Manufacturing Co., Ltd. | Soft magnetic powder |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06240309A (en) * | 1993-02-12 | 1994-08-30 | Soken Kagaku Kk | Hollow metal fine grain, metal grain group containing the fine grain and production thereof |
| JPH1180818A (en) * | 1997-09-08 | 1999-03-26 | Sumitomo Metal Mining Co Ltd | Production of metal powder, and metal powder produced by the method |
| JP2005029437A (en) * | 2003-07-08 | 2005-02-03 | Yazaki Corp | Manufacturing method of ferrite hollow particle |
| JP2005324312A (en) * | 2004-04-13 | 2005-11-24 | Toda Kogyo Corp | Nano structure substance |
| JP2006104021A (en) * | 2004-10-06 | 2006-04-20 | Hitachi Maxell Ltd | Composite particle |
-
2006
- 2006-10-24 JP JP2006289215A patent/JP2008106301A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06240309A (en) * | 1993-02-12 | 1994-08-30 | Soken Kagaku Kk | Hollow metal fine grain, metal grain group containing the fine grain and production thereof |
| JPH1180818A (en) * | 1997-09-08 | 1999-03-26 | Sumitomo Metal Mining Co Ltd | Production of metal powder, and metal powder produced by the method |
| JP2005029437A (en) * | 2003-07-08 | 2005-02-03 | Yazaki Corp | Manufacturing method of ferrite hollow particle |
| JP2005324312A (en) * | 2004-04-13 | 2005-11-24 | Toda Kogyo Corp | Nano structure substance |
| JP2006104021A (en) * | 2004-10-06 | 2006-04-20 | Hitachi Maxell Ltd | Composite particle |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010208875A (en) * | 2009-03-09 | 2010-09-24 | Tokyo Institute Of Technology | Magnetic hollow particle and method for producing the same |
| US11817245B2 (en) | 2015-07-31 | 2023-11-14 | Murata Manufacturing Co., Ltd. | Soft magnetic powder |
| US10662316B2 (en) | 2016-03-25 | 2020-05-26 | Fuji Polymer Industries Co., Ltd. | Magneto-rheological elastomer composition, method for producing same, and vibration absorbing device including same |
| CN109261984A (en) * | 2018-11-23 | 2019-01-25 | 陕西科技大学 | A kind of preparation method of Ni nano-hollow ball |
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