JPH0598321A - Production of magnetic metal powder - Google Patents
Production of magnetic metal powderInfo
- Publication number
- JPH0598321A JPH0598321A JP3259173A JP25917391A JPH0598321A JP H0598321 A JPH0598321 A JP H0598321A JP 3259173 A JP3259173 A JP 3259173A JP 25917391 A JP25917391 A JP 25917391A JP H0598321 A JPH0598321 A JP H0598321A
- Authority
- JP
- Japan
- Prior art keywords
- suspension
- temperature
- aqueous solution
- iron oxyhydroxide
- gas
- 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.)
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Links
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- Manufacture Of Metal Powder And Suspensions Thereof (AREA)
- Powder Metallurgy (AREA)
- Hard Magnetic Materials (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は高密度磁気記録媒体用の
磁性粉として用いられる、保磁力が高く、保磁力分布が
シャープであり、分散性に優れ、且つ酸化安定性に優れ
る金属磁性粉末の製造法に関するものである。FIELD OF THE INVENTION The present invention relates to a metal magnetic powder used as a magnetic powder for a high density magnetic recording medium, which has a high coercive force, a sharp coercive force distribution, an excellent dispersibility, and an excellent oxidation stability. It relates to a manufacturing method of.
【０００２】[0002]
【従来の技術】高密度磁気記録媒体用の磁性粉として、
鉄を主成分とする金属磁性粉末の開発が進められ、オー
ディオテープ、ビデオ用テープ、フロッピーディスクと
して実用化されている。金属磁性粉末の現在実用化され
ている一般的な製造法は、鉄を主体とする針状のオキシ
水酸化鉄あるいは酸化鉄を還元性ガス中で加熱還元し
て、金属あるいは合金の粉末とした後、粒子表面に薄い
酸化皮膜を形成させる方法である。近年、磁気記録再生
装置の小型軽量化、高画質化、長時間化が進められ、そ
れに伴い使用する磁気記録媒体の高密度化が強く要望さ
れている。磁気記録媒体の高密度化を達成するために
は、使用する金属磁性粉末が、微細粒子であり、保磁力
が高く、飽和磁束密度が大きく、且つ分散性に優れ、酸
化安定性にも優れる必要がある。2. Description of the Related Art As magnetic powder for high density magnetic recording media,
The development of metal magnetic powders containing iron as a main component has been promoted and put to practical use as audio tapes, video tapes, and floppy disks. A general production method of metallic magnetic powders currently in practical use is to heat and reduce needle-shaped iron oxyhydroxide or iron oxide mainly composed of iron in a reducing gas to obtain a metal or alloy powder. After that, it is a method of forming a thin oxide film on the particle surface. 2. Description of the Related Art In recent years, as magnetic recording / reproducing devices have become smaller and lighter, have higher image quality, and have a longer time, there has been a strong demand for higher density magnetic recording media to be used. In order to achieve high density of the magnetic recording medium, the metal magnetic powder used must be fine particles, high coercive force, high saturation magnetic flux density, excellent dispersibility, and excellent oxidation stability. There is.
【０００３】金属磁性粉末の保磁力は、金属の組成が一
定であるならば、針状粒子の大きさに最も影響される。
一般論として、粒子の太さが一定であれば、針状粒子の
軸比（粒子の長さ／太さ）が大であるほど保磁力は高く
なる。しかるに、最近の高密度化に伴う、より短波長で
の記録再生の必要性から、金属磁性粉末粒子の長さはよ
り短いものが要望され、また磁気記録再生ヘッドの改良
が進められて、保磁力が高いものでも使用できるように
なり、より保磁力の高いものが強く要望されている。粒
子が短いものでも、粒子の太さがより小さくなり、軸比
が大に出来るならば、保磁力を高くすることが可能であ
るが、粒子の太さを小さくすることには限界がある。こ
の理由は、一つには粒子があまり細くなると、超常磁性
が発現して保磁力を示さないことであり、二つめには金
属磁性粉末には大気中で安全に取り扱えるようにするた
めに粒子の表面に酸化皮膜が形成されており、粒子があ
まり細かくなると酸化皮膜ばかりになり、磁性を示さな
くなってしまうからである。したがって微細粒子は必然
的に軸比の小さい粒子になり、保磁力を高くすることは
難しい傾向がある。飽和磁束密度は金属磁性粉末の組
成、粒子の大きさ、酸化皮膜の厚さにより変化する。組
成としては、鉄を主体とした合金を考えた場合、コバル
トの添加が有効である。粒子の大きさでは粒子が大きい
程、粒子表面の酸化皮膜の厚さが同じもの同士を比較す
ると、酸化皮膜の量と金属部分の割合において、金属部
分の割合が大きくなり、飽和磁束密度も当然のことなが
ら大きくなる。粒子体積が同じものを比較すると、酸化
皮膜の厚さが同じものでは、軸比の小さい方が表面積も
小さく、酸化皮膜の割合が小さくなり、飽和磁束密度は
大きくなる。しかし、軸比は保磁力に大きく影響するの
で、極端に小さくはできない。酸化皮膜を薄くすること
により、金属磁性粉末の飽和磁束密度は大きくはなる
が、大気中で安全に取り扱うこと、また磁気記録媒体と
した時の経時安定性を考えた場合、酸化皮膜を薄くする
ことは好ましくない。金属磁性粉末の分散性は、粒子の
形状、および表面の化学的性質が大きく影響し、媒体に
使用する樹脂との相性もあるが、一般論として、粒子が
微細になるほど分散は難しくなる方向である。金属磁性
粉末の酸化安定性（高温、高湿下でのσs の経時変化）
は、酸化皮膜の緻密さや粒子表面に被覆する形状保持剤
の種類によって変化するが、粒子が微細になり、表面積
が大きくなることにより、σs の経時変化が大きくな
り、酸化安定性は悪くなる傾向がある。The coercive force of the magnetic metal powder is most affected by the size of the acicular particles if the metal composition is constant.
As a general theory, if the particle size is constant, the coercive force increases as the axial ratio (particle length / size) of the acicular particles increases. However, due to the need for recording / reproducing at shorter wavelengths with the recent increase in density, it is desired that the length of the metal magnetic powder particles be shorter, and further improvement of the magnetic recording / reproducing head is promoted, and It has become possible to use a material having a high magnetic force, and there is a strong demand for a material having a higher coercive force. Even if the particles are short, the coercive force can be increased if the particle size can be made smaller and the axial ratio can be increased, but there is a limit to reducing the particle size. The reason for this is that if the particles become too thin, superparamagnetism develops and they do not exhibit coercive force. Secondly, the metallic magnetic powder has a particle size that can be handled safely in the atmosphere. This is because an oxide film is formed on the surface of, and if the particles become too fine, only the oxide film will be formed and the magnetism will not be exhibited. Therefore, the fine particles inevitably become particles having a small axial ratio, and it tends to be difficult to increase the coercive force. The saturation magnetic flux density changes depending on the composition of the magnetic metal powder, the size of the particles, and the thickness of the oxide film. As for the composition, when considering an alloy mainly composed of iron, the addition of cobalt is effective. As for the size of the particles, the larger the particles are, the more the thickness of the oxide film on the surface of the particles is the same.Comparing those with each other, the ratio of the metal part in the amount of the oxide film and the ratio of the metal part is larger, and the saturation magnetic flux density is naturally But it grows. When the particles having the same particle volume are compared, when the oxide film has the same thickness, the smaller the axial ratio, the smaller the surface area, the smaller the ratio of the oxide film, and the higher the saturation magnetic flux density. However, the axial ratio has a great influence on the coercive force, and cannot be made extremely small. By making the oxide film thinner, the saturation magnetic flux density of the metal magnetic powder increases, but in consideration of safe handling in the air and stability over time when used as a magnetic recording medium, make the oxide film thinner. Is not preferable. The dispersibility of the metallic magnetic powder is greatly affected by the shape of the particles and the chemical properties of the surface and is compatible with the resin used for the medium, but in general the dispersion becomes more difficult as the particles become finer. is there. Oxidation stability of metallic magnetic powder (change of σs with time at high temperature and high humidity)
Varies depending on the density of the oxide film and the type of shape-retaining agent that coats the surface of the particles, but as the particles become finer and the surface area increases, σs tends to change over time and oxidation stability tends to deteriorate. There is.
【０００４】[0004]
【発明が解決しようとする課題】近年の磁気記録再生装
置の高性能化に伴い、使用する磁気記録媒体の高出力
化、低ノイズ化の要望が強く、使用する金属磁性粉末
も、微細で、保磁力が高く、飽和磁束密度の大きいもの
が望まれている。しかしながら、従来の技術では、上述
の事情によりこれらの項目を全て満足するような金属磁
性粉末は得られない。本発明はこの問題を解決すること
を目的としたものである。With the recent advances in the performance of magnetic recording / reproducing devices, there is a strong demand for higher output and lower noise of the magnetic recording medium used, and the metal magnetic powder used is also fine. A material having a high coercive force and a large saturation magnetic flux density is desired. However, according to the conventional technique, a magnetic metal powder satisfying all of these items cannot be obtained due to the above circumstances. The present invention aims to solve this problem.
【０００５】[0005]
【課題を解決するための手段】本発明者等はこの問題を
解決するために種々の検討を行った結果、第一鉄塩とア
ルカリを混合した水懸濁液に、酸化性ガスを吹き込むこ
とによって得られたオキシ水酸化鉄を主体とする種結晶
の粒子表面に、酸化反応終了後、または酸化反応途中に
おいて、該懸濁液に非酸化性雰囲気下、酸化反応終了後
の場合には懸濁液に第一鉄塩水溶液及び稀土類元素化合
物および／またはケイ素化合物の水溶液を加えた後、酸
化反応途中の場合には稀土類元素化合物および／または
ケイ素化合物の水溶液を加え、酸化反応温度以上の温度
で熟成後、再び酸化性ガスを吹き込んでオキシ水酸化鉄
結晶を成長させた後、該オキシ水酸化鉄の表面に形状保
持剤を被覆し、次いで、非還元性雰囲気下、 500〜800
℃の温度で加熱処理し、しかる後、還元性ガスで加熱還
元することにより、前記の問題が解決できることを見出
し、本発明を完成するに到った。Means for Solving the Problems As a result of various studies to solve this problem, the present inventors have found that an oxidizing gas is blown into a water suspension containing a ferrous salt and an alkali. On the particle surface of the seed crystal mainly composed of iron oxyhydroxide obtained by the above, after the completion of the oxidation reaction or in the middle of the oxidation reaction, the suspension is suspended in a non-oxidizing atmosphere and after the completion of the oxidation reaction. After adding an aqueous solution of ferrous salt and an aqueous solution of a rare earth element compound and / or a silicon compound to the suspension, add an aqueous solution of a rare earth element compound and / or a silicon compound when the oxidation reaction is in progress, and the temperature is higher than the oxidation reaction temperature. After aging at a temperature of 1, the oxidizing gas is blown again to grow iron oxyhydroxide crystals, the surface of the iron oxyhydroxide is coated with a shape-retaining agent, and then, in a non-reducing atmosphere, 500 to 800
It was found that the above problems can be solved by heat treatment at a temperature of ° C and then heat reduction with a reducing gas, and the present invention has been completed.
【０００６】本発明において使用される第一鉄塩として
は、塩化第一鉄、硫酸第一鉄、硝酸第一鉄が使用でき
る。またアルカリとしては、水酸化ナトリウム、水酸化
カリウム等の水酸化アルカリ、炭酸ナトリウム、炭酸ア
ンモニウム等の炭酸アルカリ、アンモニア等が使用でき
る。また、酸化性ガスとしては、酸素ガス、空気等の公
知のガスが使用できる。このようにして得られるオキシ
水酸化鉄としては、α−FeOOH 、β−FeOOH 、γ−FeOO
H 等があげられ、特にα−FeOOH 、γ−FeOOH が好まし
い。なお、該オキシ水酸化鉄の形状は、長軸長が0.05〜
0.3 μm 、軸比が３〜15の、針状、柱状、紡錘状、棒状
のものが好ましく、粒子中にCo，Ni，Cr，Mn，Mg，Ca，
Ba，Sr，Zn，Ti，Mo，Ag，Cu等の金属化合物が含まれる
場合にも有効である。本発明で使用される稀土類元素は
La，Ce，Pr，Nd，Sm，Gd，Dy，Y のうち少なくとも１種
類であり、これらの組合せでも有効である。添加量はオ
キシ水酸化鉄中の鉄に対して 0.3〜10wt％が好ましく、
0.5〜5.0 wt％がより好ましい。ケイ素化合物としては
メタ珪酸ソーダ、オルト珪酸ソーダ、水ガラスが使用出
来、その添加量はオキシ水酸化鉄中の鉄に対してケイ素
として 0.1〜５wt％が好ましく、さらに好ましくは 0.2
〜３wt％である。本発明で使用される形状保持剤として
は、Si，Al，B ，P のうち少なくとも１種類またはその
組合せが使用出来る。As the ferrous salt used in the present invention, ferrous chloride, ferrous sulfate and ferrous nitrate can be used. As the alkali, alkali hydroxides such as sodium hydroxide and potassium hydroxide, alkali carbonates such as sodium carbonate and ammonium carbonate, and ammonia can be used. As the oxidizing gas, known gases such as oxygen gas and air can be used. Examples of the iron oxyhydroxide thus obtained include α-FeOOH, β-FeOOH, and γ-FeOO.
H 2 and the like are mentioned, and α-FeOOH and γ-FeOOH are particularly preferable. The shape of the iron oxyhydroxide has a major axis length of 0.05 to
Needle-shaped, columnar, spindle-shaped, and rod-shaped particles having a diameter of 0.3 μm and an axial ratio of 3 to 15 are preferable, and Co, Ni, Cr, Mn, Mg, Ca,
It is also effective when metal compounds such as Ba, Sr, Zn, Ti, Mo, Ag and Cu are contained. The rare earth elements used in the present invention are
It is at least one of La, Ce, Pr, Nd, Sm, Gd, Dy, and Y, and a combination thereof is also effective. The addition amount is preferably 0.3 to 10 wt% with respect to iron in iron oxyhydroxide,
0.5 to 5.0 wt% is more preferable. Sodium metasilicate, sodium orthosilicate, and water glass can be used as the silicon compound, and the addition amount thereof is preferably 0.1 to 5 wt% as silicon with respect to iron in iron oxyhydroxide, and more preferably 0.2.
~ 3 wt%. As the shape-retaining agent used in the present invention, at least one of Si, Al, B and P or a combination thereof can be used.
【０００７】本発明について、オキシ水酸化鉄を針状の
α−FeOOH とした場合を例として説明する。先ず、第一
鉄塩とアルカリを混合した水懸濁液に、酸化性ガスを吹
き込むことによって針状α−FeOOH を主体とする種結晶
を製造する。この時の酸化反応の温度は40〜70℃で、pH
は10.5以上が望ましい。またこの時、Co，Ni，Cr，Mn，
Mg，Ca，Ba，Sr，Zn，Ti，Mo，Ag，Cu等の金属化合物が
添加されていてもよい。次に種結晶の粒子表面に、酸化
反応終了後、または酸化反応途中において、該懸濁液に
非酸化性雰囲気下、酸化反応終了後の場合には懸濁液に
第一鉄塩水溶液および稀土類元素化合物および／または
ケイ素化合物の水溶液を加えた後、酸化反応途中の場合
には稀土類元素化合物および／またはケイ素化合物の水
溶液を加え、酸化反応温度以上の温度で熟成後、再び酸
化性ガスを吹き込んで針状α−FeOOHの結晶を成長させ
る。この反応で稀土類元素化合物および／またはケイ素
化合物の添加方法は種々あるが、酸化反応終了後の場合
には、添加する第一鉄水溶液と稀土類化合物水溶液を別
々に添加しても、予め混合した水溶液を添加してもよ
い。ケイ素化合物水溶液は酸化反応終了後、第一鉄塩水
溶液を添加する前のα−FeOOH の懸濁液中に添加しても
よいし、また第一鉄塩水溶液を添加した後、この水酸化
第一鉄とα−FeOOH の懸濁液中に添加してもよい。この
工程で添加される第一鉄塩の量は添加される鉄／α−Fe
OOH 中の鉄比で10〜50モル％が好ましい。これより少な
いと添加する稀土類元素化合物および／またはケイ素化
合物が完全に成長時に取り込まれない。これより多いと
成長がうまく行われず、新たにα−ＦｅＯＯＨ結晶の核
の生成が起こり、粒子の揃いが悪くなる。熟成及び成長
反応の温度は酸化反応の温度以上で行うことが望まし
い。成長反応が酸化反応温度以下で行われると成長がう
まく行われず、新たに核の生成が起こり、粒子の揃いが
悪くなる。また反応途中で稀土類元素化合物および／ま
たはケイ素化合物を添加する場合には稀土類化合物の水
溶液を水酸化第一鉄とα−FeOOH の懸濁液に添加しても
よいし、ケイ素化合物の水溶液を水酸化第一鉄とα−Fe
OOH 懸濁液に添加してもよい。また稀土類化合物とケイ
素化合物の両方を添加する場合には、反応途中の水酸化
第一鉄とα−FeOOH 懸濁液にそれぞれの化合物の水溶液
を添加してもよいし、予め両者をよく混合して添加して
もよい。この時の酸化反応率は50〜90％が適当である。
酸化反応率が50％より低いときに添加すると、新たに核
が生成し、粒子の揃いが悪くなり、また酸化反応率が90
％を越えたときに添加すると、添加する稀土類元素化合
物および／またはケイ素化合物が完全に成長時に取り込
まれない。またこの工程で添加される稀土類元素は添加
される鉄＋α−FeOOH 中の鉄に対し、 0.3〜10wt％が好
ましく、またケイ素量は 0.1〜5.0wt ％の範囲が好まし
い。これより量が少ないと期待される形状保持効果が得
られず、保磁力の向上が望めない。これより量が多いと
飽和磁束密度が低下したり、還元に長時間を要する等の
問題が出てくる。この工程で使用される第一鉄塩および
稀土類元素化合物としては、塩化物、硫酸塩、硝酸塩等
の水溶性塩が使用できる。次いで、粒子の表面近傍に稀
土類元素化合物および／またはケイ素化合物をドープし
たα−FeOOH 懸濁液を攪拌しながら、Al，Si，B ，Pの
化合物の単独もしくはこれら化合物の組合せを含む水溶
液を添加し、pHを酸、またはアルカリを添加して５〜10
に調整することで被着し、濾過、洗浄、乾燥する。次い
で、非還元性雰囲気中で 500〜800 ℃の温度で加熱処理
し、しかる後、還元性ガスで加熱還元することで金属磁
性粉末を得る。The present invention will be described with reference to an example in which iron oxyhydroxide is acicular α-FeOOH. First, a seed crystal mainly composed of acicular α-FeOOH is produced by blowing an oxidizing gas into a water suspension prepared by mixing a ferrous salt and an alkali. The temperature of the oxidation reaction at this time is 40-70 ℃, and the pH
Is preferably 10.5 or higher. At this time, Co, Ni, Cr, Mn,
Metal compounds such as Mg, Ca, Ba, Sr, Zn, Ti, Mo, Ag, and Cu may be added. Next, on the surface of the seed crystal particles, after the oxidation reaction is completed or during the oxidation reaction, the suspension is under a non-oxidizing atmosphere, and when the oxidation reaction is completed, the suspension is ferrous salt aqueous solution and rare earth. After adding an aqueous solution of a group element compound and / or a silicon compound, if an oxidation reaction is in progress, add an aqueous solution of a rare earth element compound and / or a silicon compound, and after aging at a temperature equal to or higher than the oxidation reaction temperature, an oxidizing gas is added again. Are blown in to grow acicular α-FeOOH crystals. In this reaction, there are various methods for adding the rare earth element compound and / or the silicon compound, but after the completion of the oxidation reaction, the ferrous iron aqueous solution and the rare earth compound aqueous solution to be added may be added separately and mixed in advance. The aqueous solution may be added. The aqueous solution of the silicon compound may be added to the suspension of α-FeOOH before the addition of the aqueous solution of the ferrous salt after the completion of the oxidation reaction, or after the aqueous solution of the ferrous salt is added, the hydroxide of the ferric salt is added. It may be added to a suspension of ferrous iron and α-FeOOH. The amount of ferrous salt added in this step is iron / α-Fe added
The iron ratio in OOH is preferably 10 to 50 mol%. If the amount is less than this, the rare earth element compound and / or the silicon compound added are not completely incorporated during the growth. If the amount is larger than this, the growth does not proceed well, and new nuclei of α-FeOOH crystals occur, resulting in poor grain alignment. The temperature of the aging and growth reaction is preferably higher than the temperature of the oxidation reaction. If the growth reaction is carried out at a temperature lower than the oxidation reaction temperature, the growth will not be successful, new nucleation will occur, and the uniformity of the particles will deteriorate. When a rare earth element compound and / or a silicon compound is added during the reaction, an aqueous solution of a rare earth compound may be added to a suspension of ferrous hydroxide and α-FeOOH, or an aqueous solution of a silicon compound. Ferrous hydroxide and α-Fe
May be added to OOH suspension. When adding both the rare earth compound and the silicon compound, an aqueous solution of each compound may be added to the ferrous hydroxide and α-FeOOH suspension during the reaction, or both may be mixed well beforehand. You may add it. It is appropriate that the oxidation reaction rate at this time is 50 to 90%.
If it is added when the oxidation reaction rate is lower than 50%, new nuclei are generated, the particle alignment becomes poor, and the oxidation reaction rate becomes 90%.
If it is added when the content exceeds%, the added rare earth element compound and / or silicon compound is not completely incorporated during the growth. Further, the rare earth element added in this step is preferably 0.3 to 10 wt% and the amount of silicon is preferably 0.1 to 5.0 wt% with respect to the iron in the iron + α-FeOOH to be added. If the amount is smaller than this, the expected shape-retaining effect cannot be obtained, and improvement in coercive force cannot be expected. If the amount is larger than this, there arise problems that the saturation magnetic flux density is lowered, and that reduction takes a long time. As the ferrous salt and the rare earth element compound used in this step, water-soluble salts such as chlorides, sulfates and nitrates can be used. Next, while stirring the α-FeOOH suspension doped with the rare earth element compound and / or the silicon compound in the vicinity of the surface of the particles, an aqueous solution containing a single compound of Al, Si, B and P or a combination of these compounds is prepared. Add pH to add acid or alkali 5-10
By adjusting to, it is attached, filtered, washed and dried. Then, heat treatment is performed at a temperature of 500 to 800 ° C. in a non-reducing atmosphere, and thereafter, heat reduction is performed with a reducing gas to obtain a metal magnetic powder.
【０００８】[0008]
【作用】本発明の第一の効果は加熱還元時の粒子の形状
保持効果にある。従来の技術においても粒子表面にAl，
Si，B , P 等の化合物の一種、またはこれらの組合せを
存在させ、形状保持効果を得ているが、本発明では、形
状保持剤の下層に稀土類元素化合物および／またはケイ
素化合物をドープさせておくことにより、形状保持効果
がさらに優れたものになり、その結果として、ほぼ同じ
サイズの粒子で従来技術で製造したものと、粉体磁気特
性を比較すると、保磁力が顕著に高くなり、角型比も向
上する。また、温度＝60℃、相対湿度＝90％雰囲気中で
１週間放置した後の飽和磁束密度（σs ）の保持率も高
く、酸化安定性にも優れている。さらに、この金属磁性
粉末をテープ化して磁気特性を測定すると、Br，角型
比、Ｓ．Ｆ．Ｄ（突発性周波数変動）が従来技術で製造
したものに比較して優れている。このことは、本発明で
製造した金属磁性粉が塗料中での分散性、パッキング性
に優れることを示している。また、テープでのＳ．Ｆ．
Ｄ．が小さいことは、粉体の保磁力分布がシャープであ
ることを示している。本発明で得られた金属磁性粉末の
この優れた特性の発現理由については明らかではない
が、形状保持剤の下層に難還元性で、酸素との親和力の
強い稀土類元素化合物および／またはケイ素化合物が存
在することにより、熱処理時の熱による歪みで粒子表面
の形状保持剤と内部の鉄を主体とする酸化物が遊離した
り、加熱還元時に、内部の酸化物が還元され収縮して粒
子内に空孔を生じたり、粒子がちぎれたり、粒子の一部
分だけが還元が進行してコブのついた粒子になったり、
あるいは粒子同士が焼結すること等を防止する効果が顕
著に現れるためと考えられる。The first effect of the present invention is the effect of retaining the shape of particles during reduction by heating. Even in the conventional technology, Al on the particle surface,
One or a combination of compounds such as Si, B, and P is present to obtain a shape-retaining effect. In the present invention, the lower layer of the shape-retaining agent is doped with a rare earth element compound and / or a silicon compound. By setting it in advance, the shape retention effect becomes more excellent, and as a result, the coercive force becomes remarkably higher when comparing the powder magnetic characteristics with those manufactured by the conventional technique using particles of approximately the same size, The squareness ratio is also improved. Further, it has a high retention rate of saturation magnetic flux density (σs) after being left for 1 week in an atmosphere of temperature = 60 ° C. and relative humidity = 90%, and is excellent in oxidation stability. Further, when the magnetic characteristics were measured by tape-forming this metal magnetic powder, the Br, squareness ratio, S. F. D (sudden frequency fluctuation) is superior to that produced by the conventional technique. This indicates that the magnetic metal powder produced by the present invention is excellent in dispersibility in a paint and packing property. In addition, S. F.
D. A small value indicates that the coercive force distribution of the powder is sharp. The reason why the excellent properties of the metallic magnetic powder obtained in the present invention are expressed is not clear, but a rare earth element compound and / or a silicon compound which is difficult to reduce in the lower layer of the shape-retaining agent and has a strong affinity with oxygen. Due to the presence of the, the heat-induced strain during heat treatment liberates the shape-retaining agent on the surface of the particle and the internal iron-based oxide, and during heat reduction, the internal oxide is reduced and contracts to Vacancies may be generated, particles may be broken, or only part of the particles may be reduced and become particles with bumps,
Alternatively, it is considered that the effect of preventing the particles from sintering is remarkably exhibited.
【０００９】[0009]
【実施例】以下に実施例を挙げて本発明を更に詳しく説
明するが、本発明はこれらに限定されるものではない。The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.
【００１０】実施例１ 窒素ガスを流して酸化性ガスを追い出した容器に、2.0m
ol/lの塩化第一鉄水溶液４リットルと1.5mol/lの水酸化
ナトリウム水溶液20リットルを混合した懸濁液に、空気
を１時間吹き込むことによって、完全に酸化し、針状の
α−FeOOH を得た。この時の反応は40℃の温度で行っ
た。この懸濁液に非酸化性雰囲気下で、0.5mol/lの塩化
第一鉄水溶液２リットルおよび0.1mol/lの塩化ランタン
水溶液１リットルを加え、１時間攪拌した。この時の熟
成は45℃の温度で行った。この後再び空気を吹き込み、
ランタンを表面にドープした針状のα−FeOOH を得た。
このα−FeOOH を濾過、水洗後、再び40リットルの蒸留
水に分散させ、この懸濁液に0.5mol/lの塩化アルミニュ
ーム水溶液２リットルを添加して30分間攪拌した。水酸
化ナトリウム水溶液を徐々に添加して懸濁液のpHを８に
調整して、水酸化アルミニュームを針状のα−FeOOH 粒
子の表面に被覆した。この懸濁液を濾過、水洗後、120
℃の乾燥器中で乾燥した。この乾燥ケーキを窒素雰囲気
中 700℃で３時間熱処理し、次いで、水素ガス流下 470
℃の温度で６時間還元した。還元後、ガスを窒素ガスに
変え、温度を室温まで下げた後、窒素ガス流中に空気を
徐々に流して、常法により安定化処理を行って長軸長
0.2μm、軸比10の金属磁性粉末を得た。透過電子顕微鏡
で粒子を観察したところ、形崩れや焼結のない、また粒
子中に空孔の少ない粒子であった粉末の磁気特性及び温
度＝60℃、相対湿度＝90％中での１週間後の飽和磁束密
度（σs ）の数値を表１に示した。また、得られた金属
磁性粉末をテープ化して測定した磁気特性を表２に示し
た。テープ化は以下の方法で行った。又、以下の実施
例、比較例についても同様に、金属磁性粉末の磁気特性
を表１に、テープにした場合の磁気特性を表２に示し
た。Example 1 In a container in which nitrogen gas was flowed to drive out oxidizing gas, 2.0 m
A mixture of 4 liters of ol / l ferrous chloride aqueous solution and 20 liters of 1.5 mol / l sodium hydroxide aqueous solution was blown with air for 1 hour to completely oxidize and acicular α-FeOOH Got The reaction at this time was carried out at a temperature of 40 ° C. To this suspension, under a non-oxidizing atmosphere, 2 liters of a 0.5 mol / l ferrous chloride aqueous solution and 1 liter of a 0.1 mol / l lanthanum chloride aqueous solution were added and stirred for 1 hour. The aging at this time was performed at a temperature of 45 ° C. After this, blow air again,
Needle-like α-FeOOH having lanthanum doped on the surface was obtained.
The α-FeOOH was filtered, washed with water, dispersed again in 40 liters of distilled water, and 2 liters of a 0.5 mol / l aluminum chloride aqueous solution was added to this suspension, followed by stirring for 30 minutes. The pH of the suspension was adjusted to 8 by gradually adding an aqueous sodium hydroxide solution, and aluminum hydroxide was coated on the surface of the needle-shaped α-FeOOH particles. This suspension is filtered and washed with water, then 120
It was dried in a dryer at 0 ° C. The dried cake was heat-treated at 700 ° C. for 3 hours in a nitrogen atmosphere, and then heated under a flow of hydrogen gas.
Reduction was carried out at a temperature of ° C for 6 hours. After the reduction, the gas was changed to nitrogen gas, the temperature was lowered to room temperature, and then air was gradually flown into the nitrogen gas flow to perform stabilization treatment by a conventional method to obtain a long axis length.
A metal magnetic powder having a diameter of 0.2 μm and an axial ratio of 10 was obtained. Observation of the particles with a transmission electron microscope showed that the particles had no deformation or sintering, and had few voids in the particles. Magnetic properties of the powder and temperature = 60 ° C, relative humidity = 90% for 1 week. The values of the saturation magnetic flux density (σs) after that are shown in Table 1. Further, Table 2 shows the magnetic characteristics measured by tape-forming the obtained metal magnetic powder. Tape formation was performed by the following method. Similarly, in the following Examples and Comparative Examples, the magnetic characteristics of the metal magnetic powder are shown in Table 1, and the magnetic characteristics of the tape are shown in Table 2.
【００１１】テープ化の方法及び評価 金属粉末100gとポリウレタン樹脂11g 、塩化ビニル−酢
酸ビニル共重合体7.75g 、トルエン／メチルエチルケト
ン／シクロヘキサノン＝１／１／１の混合溶液345gとを
混合し、サンドグラインダーで５時間分散を行って磁性
塗料を作成した。この塗料に架橋剤としてコロネートＬ
を2.5g添加したのち、ポリエステルフィルムに塗布し、
3000ガウスの磁界を印加して、50℃の温度で乾燥した。
次いで80℃、線圧200Kg/cmでカレンダー処理を行い、60
℃で24時間熟成を行った後、カットしてＶＳＭ磁力計を
用いて最大印加磁場５kOe で磁気特性を測定した。 Tape forming method and evaluation 100 g of metal powder, 11 g of polyurethane resin, 7.75 g of vinyl chloride-vinyl acetate copolymer, and 345 g of a mixed solution of toluene / methyl ethyl ketone / cyclohexanone = 1/1/1 were mixed, and a sand grinder was used. Was dispersed for 5 hours to prepare a magnetic paint. Coronate L as a cross-linking agent for this paint
After adding 2.5 g, apply it to a polyester film,
A magnetic field of 3000 gauss was applied and drying was performed at a temperature of 50 ° C.
Next, calender at 80 ℃ and linear pressure of 200Kg / cm.
After aging at 24 ° C. for 24 hours, it was cut and the magnetic characteristics were measured using a VSM magnetometer with a maximum applied magnetic field of 5 kOe.
【００１２】実施例２〜４ 稀土類金属元素の種類および添加量を変えた以外は実施
例１と同様にして金属磁性粉末を得た。Examples 2 to 4 Metal magnetic powders were obtained in the same manner as in Example 1 except that the kind and addition amount of rare earth metal elements were changed.
【００１３】実施例５ 窒素ガスを流して酸化性ガスを追い出した容器に、8.0m
olの塩化第一鉄と0.3molの塩化ニッケルを４リットルの
蒸留水に溶解した混合溶液と1.5mol/lの水酸化ナトリウ
ム水溶液20リットルを混合した懸濁液に、空気を１時間
吹き込むことによって完全に酸化し、針状のα−FeOOH
を得た。この時の反応は40℃の温度で行った。この懸濁
液に非酸化性雰囲気下0.5mol/lの塩化第一鉄水溶液２リ
ットルおよびSiO2換算で100g/lの濃度の水ガラスを75ml
加え、１時間攪拌した。この時の熟成は45℃の温度で行
った。この後再び空気を吹き込みケイ素化合物を表面に
ドープした針状のα−FeOOH を得た。この針状のα−Fe
OOH を濾過、水洗後、再び40リットルの蒸留水に分散さ
せ、この懸濁液に0.5mol/lの塩化アルミニューム水溶液
２リットルを添加し、30分攪拌した。水酸化ナトリウム
水溶液を徐々に添加してpHを８に調整して水酸化アルミ
ニュームを針状のα−FeOOH の表面に被覆した。この懸
濁液を濾過、水洗後 120℃の乾燥機中で乾燥した。この
乾燥ケーキを窒素雰囲気下、 700℃で３時間熱処理し、
次いで水素ガス流下、 470℃の温度で６時間還元を行っ
た。還元後、ガスを窒素ガスに変え、温度を室温まで下
げた後、窒素ガス流中に空気を徐々に流して常法により
安定化処理を行って金属磁性粉末を得た。Example 5 In a container in which nitrogen gas was flowed to remove oxidizing gas, 8.0 m
by blowing air for 1 hour into a suspension prepared by mixing ol ferrous chloride and 0.3 mol of nickel chloride in 4 liters of distilled water and 20 liters of a 1.5 mol / l sodium hydroxide aqueous solution. Fully oxidized and needle-shaped α-FeOOH
Got The reaction at this time was carried out at a temperature of 40 ° C. To this suspension, 2 ml of 0.5 mol / l ferrous chloride aqueous solution and 75 ml of water glass having a concentration of 100 g / l in terms of SiO 2 were added in a non-oxidizing atmosphere.
Addition and stirring for 1 hour. The aging at this time was performed at a temperature of 45 ° C. After that, air was blown again to obtain needle-shaped α-FeOOH having a surface doped with a silicon compound. This needle-shaped α-Fe
The OOH was filtered, washed with water, dispersed again in 40 liters of distilled water, and 2 liters of a 0.5 mol / l aluminum chloride aqueous solution was added to this suspension, followed by stirring for 30 minutes. The pH was adjusted to 8 by gradually adding an aqueous sodium hydroxide solution, and aluminum hydroxide was coated on the surface of the needle-shaped α-FeOOH. The suspension was filtered, washed with water, and dried in a dryer at 120 ° C. This dried cake was heat-treated at 700 ° C for 3 hours in a nitrogen atmosphere,
Then, reduction was carried out at a temperature of 470 ° C. for 6 hours under the flow of hydrogen gas. After the reduction, the gas was changed to nitrogen gas, the temperature was lowered to room temperature, and then air was gradually passed through the nitrogen gas flow to carry out a stabilization treatment by a conventional method to obtain a metal magnetic powder.
【００１４】実施例６ 窒素ガスを流して、酸化性ガスを追い出した容器に、8.
0molの塩化第一鉄と0.25mol の塩化ニッケルを４リット
ルの蒸留水に溶解した混合溶液と1.5mol/lの水酸化ナト
リウム水溶液20リットルを混合した懸濁液に、空気を40
分間吹き込むことによって、第一鉄の70％を酸化した。
この時の反応は40℃の温度で行った。この懸濁液に非酸
化性雰囲気下、0.1mol/lの塩化ネオジム１リットルおよ
びSiO2換算で、100g/lの濃度の水ガラスを70ml加え、１
時間攪拌した。この時の熟成は45℃の温度で行った。こ
の後再び空気を吹き込み、ネオジム化合物及びケイ素化
合物をドープした針状のα−FeOOH を得た。この針状の
α−FeOOH を濾過、水洗後、再び40リットルの蒸留水に
分散させ、この懸濁液に0.5mol/lの塩化アルミニューム
水溶液２リットルを添加し、30分攪拌した。水酸化ナト
リウム水溶液を徐々に添加してpHを８に調整し、水酸化
アルミニュームを針状のα−FeOOH の表面に被覆した。
この懸濁液を濾過、水洗後 120℃の乾燥器中で10時間乾
燥した。この乾燥ケーキを窒素雰囲気中 700℃の温度で
３時間熱処理し、次いで水素ガス流下、500 ℃の温度で
６時間還元を行った。還元後、ガスを窒素ガスに変え、
温度を室温まで下げた後、窒素ガス流中に空気を徐々に
流して常法により安定化処理を行って金属磁性粉末を得
た。Example 6 A container in which the oxidizing gas was expelled by flowing a nitrogen gas, 8.
Air was added to a suspension prepared by dissolving 0 mol of ferrous chloride and 0.25 mol of nickel chloride in 4 liters of distilled water and 20 liters of 1.5 mol / l sodium hydroxide aqueous solution.
70% of the ferrous iron was oxidized by bubbling for minutes.
The reaction at this time was carried out at a temperature of 40 ° C. To this suspension, in a non-oxidizing atmosphere, add 1 liter of 0.1 mol / l neodymium chloride and 70 ml of water glass having a concentration of 100 g / l in terms of SiO 2.
Stir for hours. The aging at this time was performed at a temperature of 45 ° C. Thereafter, air was blown again to obtain needle-shaped α-FeOOH doped with the neodymium compound and the silicon compound. This needle-shaped α-FeOOH was filtered and washed with water, then dispersed again in 40 liters of distilled water, and 2 liters of 0.5 mol / l aluminum chloride aqueous solution was added to this suspension, followed by stirring for 30 minutes. The pH was adjusted to 8 by gradually adding an aqueous solution of sodium hydroxide, and the surface of the needle-shaped α-FeOOH was coated with aluminum hydroxide.
This suspension was filtered, washed with water, and then dried in a dryer at 120 ° C. for 10 hours. This dried cake was heat-treated in a nitrogen atmosphere at a temperature of 700 ° C. for 3 hours, and then reduced under a flow of hydrogen gas at a temperature of 500 ° C. for 6 hours. After reduction, change the gas to nitrogen gas,
After the temperature was lowered to room temperature, air was gradually flown into the nitrogen gas stream to carry out stabilization treatment by a conventional method to obtain a metal magnetic powder.
【００１５】実施例７ 窒素ガスを流して酸化性ガスを追い出した容器に、8.0m
olの塩化第一鉄と0.25mol の塩化ニッケルを４リットル
の蒸留水に溶解した混合溶液と1.5mol/lの水酸化ナトリ
ウム水溶液20リットルを混合した懸濁液に、空気を40分
間吹き込むことによって、第一鉄の70％を酸化した。こ
の時の反応は40℃の温度で行った。この懸濁液に非酸化
性雰囲気下、0.1mol/lの塩化ネオジム１リットルおよび
SiO2換算で100g/l濃度の水ガラスを70ml加え、１時間攪
拌した。この時の熟成は45℃の温度で行った。この後再
び空気を吹き込み、ネオジム化合物およびケイ素化合物
をドープした針状のα−FeOOH を得た。この針状のα−
FeOOH を濾過、水洗後、再び40リットルの蒸留水に分散
させ、この懸濁液に成長反応に使用したものと同じ濃度
の水ガラス900ml を添加し、30分攪拌した。塩酸水溶液
を徐々に添加してpHを８に調整してケイ素化合物を針状
のα−FeOOH の表面に被覆した。この懸濁液を濾過、水
洗して 120℃の乾燥器中で10時間乾燥した。この乾燥ケ
ーキを窒素雰囲気中 600℃の温度で３時間熱処理し、次
いで、水素ガス流下 520℃で６時間還元した。安定化は
実施例１と同じように行い金属磁性粉末を得た。Example 7 In a container in which nitrogen gas was flowed to remove oxidizing gas, 8.0 m
By blowing air for 40 minutes into a suspension obtained by mixing ol ferrous chloride and 0.25 mol nickel chloride in 4 liters of distilled water and 20 liters of 1.5 mol / l sodium hydroxide aqueous solution. , Oxidized 70% of ferrous iron. The reaction at this time was carried out at a temperature of 40 ° C. 1 liter of 0.1 mol / l neodymium chloride in a non-oxidizing atmosphere and
70 ml of water glass having a concentration of 100 g / l in terms of SiO 2 was added and stirred for 1 hour. The aging at this time was performed at a temperature of 45 ° C. After that, air was blown again to obtain needle-shaped α-FeOOH doped with the neodymium compound and the silicon compound. This needle-shaped α-
FeOOH was filtered, washed with water, dispersed again in 40 liters of distilled water, 900 ml of water glass having the same concentration as that used in the growth reaction was added to this suspension, and the mixture was stirred for 30 minutes. The pH was adjusted to 8 by gradually adding a hydrochloric acid aqueous solution, and the silicon compound was coated on the surface of the acicular α-FeOOH. This suspension was filtered, washed with water, and dried in a dryer at 120 ° C. for 10 hours. The dried cake was heat-treated in a nitrogen atmosphere at a temperature of 600 ° C. for 3 hours and then reduced under a flow of hydrogen gas at 520 ° C. for 6 hours. Stabilization was performed in the same manner as in Example 1 to obtain a metal magnetic powder.
【００１６】実施例８ 窒素ガスを流して、酸化性ガスを追い出した容器に、2.
0mol/lの塩化第一鉄水溶液４リットルと２mol/l の塩化
コバルト水溶液 200mlおよび1.5mol/lの水酸化ナトリウ
ム水溶液20リットルを混合した懸濁液に、空気を40分間
吹き込むことによって、第一鉄の70％を酸化した。この
時の反応は40℃の温度で行った。この懸濁液に非酸化性
雰囲気下、0.1mol/lの塩化ネオジム水溶液を１リットル
およびSiO2換算で100g/lの濃度の水ガラスを70ml加え、
１時間攪拌した。この時の熟成は45℃の温度で行った。
この後再び空気を吹き込みネオジム化合物およびケイ素
化合物をドープした針状のα−FeOOH を得た。この針状
のα−FeOOH を濾過、水洗後、再び40リットルの蒸留水
に分散させ、この懸濁液に0.5mol/lの塩化アルミニュー
ム水溶液１リットルを添加し、30分攪拌した。水酸化ナ
トリウム水溶液を徐々に添加してpHを８に調整して、水
酸化アルミニュームを針状のα−FeOOH に被覆した。こ
の懸濁液を濾過、水洗後、圧搾して水分を良く絞った湿
ケーキを得た。この湿ケーキに0.25mol の硼酸をできる
だけ少量の蒸留水に溶解した水溶液を加え、十分に混合
し、 120℃の乾燥器中で10時間乾燥した。この乾燥ケー
キを窒素雰囲気下 550℃の温度で熱処理し、次いで、水
素ガス流下、 480℃の温度で６時間還元した。安定化は
実施例１と同様に行い金属磁性粉末を得た。Example 8 In a container in which nitrogen gas was flowed to remove the oxidizing gas, 2.
By blowing air for 40 minutes into a suspension prepared by mixing 4 liters of 0 mol / l ferrous chloride aqueous solution, 200 ml of 2 mol / l cobalt chloride aqueous solution and 20 liters of 1.5 mol / l sodium hydroxide aqueous solution, Oxidized 70% of iron. The reaction at this time was carried out at a temperature of 40 ° C. To this suspension, under a non-oxidizing atmosphere, 1 liter of a 0.1 mol / l neodymium chloride aqueous solution and 70 ml of water glass having a concentration of 100 g / l in terms of SiO 2 were added,
Stir for 1 hour. The aging at this time was performed at a temperature of 45 ° C.
After that, air was blown again to obtain needle-shaped α-FeOOH doped with the neodymium compound and the silicon compound. This needle-shaped α-FeOOH was filtered and washed with water, then dispersed again in 40 liters of distilled water, and 1 liter of a 0.5 mol / l aluminum chloride aqueous solution was added to this suspension, followed by stirring for 30 minutes. The pH was adjusted to 8 by gradually adding an aqueous solution of sodium hydroxide, and the aluminum hydroxide was coated on the needle-shaped α-FeOOH. The suspension was filtered, washed with water, and then pressed to obtain a wet cake whose water content was well squeezed. An aqueous solution prepared by dissolving 0.25 mol of boric acid in as little distilled water as possible was added to the wet cake, mixed well, and dried in a dryer at 120 ° C for 10 hours. The dried cake was heat-treated under a nitrogen atmosphere at a temperature of 550 ° C. and then reduced under a flow of hydrogen gas at a temperature of 480 ° C. for 6 hours. Stabilization was performed in the same manner as in Example 1 to obtain a metal magnetic powder.
【００１７】実施例９ 窒素ガスを流して酸化性ガスを追い出した容器に、2.0m
ol/lの塩化第一鉄水溶液４リットルと2.0mol/lの塩化コ
バルト水溶液200ml 、および0.5mol/lの炭酸ナトリウム
水溶液20リットルを混合した懸濁液に、空気を１時間吹
き込むことによって、完全に酸化し紡錘状のα−FeOOH
を得た。この時の反応は40℃の温度で行った。この懸濁
液に非酸化性雰囲気下、0.5mol/lの塩化第一鉄水溶液２
リットルおよび0.1mol/lの塩化ネオジム水溶液１リット
ルとSiO2換算で100g/lの濃度の水ガラスを36ml加え、１
時間攪拌した。この時の熟成は45℃の温度で行った。こ
の後再び空気を吹き込みネオジム化合物およびケイ素化
合物をドープした紡錘状のα−FeOOH を得た。この紡錘
状のα−FeOOH を濾過、水洗後、再び40リットルの蒸留
水に分散させ、この懸濁液に成長反応で使用したのと同
じ濃度の水ガラス400ml を添加し、30分間攪拌した。塩
酸水溶液を徐々に添加しpHを８に調整し、ついで0.5mol
/lの塩化アルミニューム水溶液１リットルを添加し、30
分間攪拌した。水酸化ナトリウム水溶液を徐々に添加し
pHを８に調整し、紡錘状のα−FeOOHの表面にケイ素化
合物および水酸化アルミニュームを被覆した。この懸濁
液を濾過、水洗後 120℃の乾燥器中で10時間乾燥した。
この乾燥ケーキを窒素雰囲気中 500℃で３時間熱処理
し、次いで、水素ガス流下 480℃で６時間還元した。安
定化処理は実施例１と同様に行い金属磁性粉末を得た。Example 9 In a container in which nitrogen gas was flowed to drive out oxidizing gas, 2.0 m
A suspension of 4 liters of ol / l ferrous chloride aqueous solution, 2.0 mol / l of cobalt chloride aqueous solution 200 ml, and 0.5 mol / l of sodium carbonate aqueous solution of 20 liter was thoroughly blown with air for 1 hour, Spindle-shaped α-FeOOH
Got The reaction at this time was carried out at a temperature of 40 ° C. Into this suspension, in a non-oxidizing atmosphere, 0.5 mol / l ferrous chloride aqueous solution 2
Liter and 1 liter of 0.1 mol / l neodymium chloride aqueous solution and 36 ml of water glass having a concentration of 100 g / l in terms of SiO 2 were added.
Stir for hours. The aging at this time was performed at a temperature of 45 ° C. Thereafter, air was blown again to obtain a spindle-shaped α-FeOOH doped with the neodymium compound and the silicon compound. The spindle-shaped α-FeOOH was filtered, washed with water, dispersed again in 40 liters of distilled water, 400 ml of water glass having the same concentration as used in the growth reaction was added to this suspension, and the mixture was stirred for 30 minutes. Slowly add hydrochloric acid solution to adjust the pH to 8, then 0.5 mol
Add 1 liter of aluminum chloride aqueous solution of 1 / l to 30
Stir for minutes. Gradually add aqueous sodium hydroxide solution
The pH was adjusted to 8, and the surface of the spindle-shaped α-FeOOH was coated with a silicon compound and aluminum hydroxide. This suspension was filtered, washed with water, and then dried in a dryer at 120 ° C. for 10 hours.
The dried cake was heat-treated at 500 ° C. for 3 hours in a nitrogen atmosphere, and then reduced at 480 ° C. for 6 hours under flowing hydrogen gas. The stabilization treatment was performed in the same manner as in Example 1 to obtain a metal magnetic powder.
【００１８】比較例１ ランタン化合物をドープしなかった以外は実施例１と同
様な操作で金属磁性粉末を得た。Comparative Example 1 A metal magnetic powder was obtained in the same manner as in Example 1 except that the lanthanum compound was not doped.
【００１９】金属磁性粉末を透過型電子顕微鏡で観察し
たところ、粒子の形崩れや粒子中に空孔のあるものが目
立った。When the magnetic metal powder was observed with a transmission electron microscope, it was found that the particles were deformed or the particles had voids.
【００２０】比較例２ ケイ素化合物をドープしなかった以外は実施例５と同様
な操作で金属磁性粉末を得た。Comparative Example 2 A magnetic metal powder was obtained in the same manner as in Example 5, except that the silicon compound was not doped.
【００２１】比較例３ ネオジム化合物、ケイ素化合物をドープしなかった以外
は実施例７と同様な操作で金属磁性粉末を得た。Comparative Example 3 A magnetic metal powder was obtained in the same manner as in Example 7, except that the neodymium compound and silicon compound were not doped.
【００２２】比較例４ ネオジム化合物、ケイ素化合物をドープしなかった以外
は実施例９と同様な操作で金属磁性粉末を得た。Comparative Example 4 A metal magnetic powder was obtained in the same manner as in Example 9 except that the neodymium compound and the silicon compound were not doped.
【００２３】[0023]
【表１】 [Table 1]
【００２４】（表１の注） *1 ：（ ）内は種結晶のオキシ水酸化鉄中にドープさ
れている金属。 *2 ：窒素吸着法で測定した比表面積値。 *3 ：温度＝60℃、相対湿度＝90％中に１週間放置した
後のσs 値。(Note in Table 1) * 1: The metal in () is the metal doped in the seed crystal iron oxyhydroxide. * 2: Specific surface area value measured by nitrogen adsorption method. * 3: σs value after standing for 1 week in temperature = 60 ° C, relative humidity = 90%.
【００２５】[0025]
【表２】 [Table 2]
【００２６】[0026]
【発明の効果】表１，２で明らかなように、本発明で得
られた金属磁性粉末は従来の方法で得られたものに比較
して保磁力が高く、分散性も良好であり、且つ酸化安定
性も優れているものである。テープにした時のＳ．Ｆ．
Ｄ値も小さく、保磁力分布もシャープであることを示し
ている。従って、高密度磁気記録媒体用の磁性粉として
好適のものである。特に、金属磁性粉末の軸比が小さく
ても十分な保磁力が得られるので、短波長記録再生用の
媒体の磁性粉として最適のものである。As is apparent from Tables 1 and 2, the metal magnetic powder obtained by the present invention has a high coercive force and a good dispersibility as compared with those obtained by the conventional method, and It also has excellent oxidative stability. S. when taped F.
It shows that the D value is small and the coercive force distribution is sharp. Therefore, it is suitable as a magnetic powder for a high density magnetic recording medium. In particular, since a sufficient coercive force can be obtained even if the axial ratio of the metal magnetic powder is small, it is optimal as a magnetic powder for a medium for short wavelength recording / reproducing.
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.5 識別記号 庁内整理番号 ＦＩ 技術表示箇所 Ｈ０１Ｆ 1/06 (72)発明者 吉田 功 群馬県渋川市金井425番地 関東電化工業 株式会社研究開発センター内─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 5 Identification number Internal reference number FI Technical indication location H01F 1/06 (72) Inventor Isao Yoshida 425 Kanai Shibukawa City Gunma Kanto Denka Kogyo Co., Ltd. R & D In the center
Claims (2)
に、酸化性ガスを吹き込むことによって得られたオキシ
水酸化鉄を主体とする種結晶の粒子表面に、酸化反応途
中において、該懸濁液に非酸化性雰囲気下、稀土類元素
化合物および／またはケイ素化合物の水溶液を加え、酸
化反応温度以上の温度で熟成後、再び酸化性ガスを吹き
込んでオキシ水酸化鉄結晶を成長させた後、該オキシ水
酸化鉄の表面に形状保持剤を被覆し、次いで、非還元性
雰囲気下、 500〜800℃の温度で加熱処理し、しかる
後、還元性ガスで加熱還元することを特徴とする金属磁
性粉末の製造法。1. On the surface of a seed crystal particle mainly composed of iron oxyhydroxide obtained by blowing an oxidizing gas into a water suspension prepared by mixing a ferrous salt and an alkali, during the oxidation reaction, An aqueous solution of a rare earth element compound and / or a silicon compound is added to the suspension under a non-oxidizing atmosphere, the mixture is aged at a temperature equal to or higher than the oxidation reaction temperature, and then an oxidizing gas is blown into the suspension to grow iron oxyhydroxide crystals. After that, the surface of the iron oxyhydroxide is coated with a shape-retaining agent, followed by heat treatment at a temperature of 500 to 800 ° C. in a non-reducing atmosphere, and then heat reduction with a reducing gas. And a method for producing metallic magnetic powder.
に、酸化性ガスを吹き込むことによって得られたオキシ
水酸化鉄を主体とする種結晶の粒子表面に、酸化反応終
了後、該懸濁液に非酸化性雰囲気下、懸濁液に第一鉄塩
水溶液と稀土類元素化合物および／またはケイ素化合物
の水溶液を加えた後、酸化反応温度以上の温度で熟成
後、再び酸化性ガスを吹き込んでオキシ水酸化鉄結晶を
成長させた後、該オキシ水酸化鉄の表面に形状保持剤を
被覆し、次いで、非還元性雰囲気下、 500〜800 ℃の温
度で加熱処理し、しかる後、還元性ガスで加熱還元する
ことを特徴とする金属磁性粉末の製造法。2. The surface of the seed crystal particles mainly composed of iron oxyhydroxide obtained by blowing an oxidizing gas into an aqueous suspension mixture of a ferrous salt and an alkali, after completion of the oxidation reaction, After adding an aqueous solution of ferrous salt and an aqueous solution of a rare earth element compound and / or a silicon compound to the suspension in a non-oxidizing atmosphere, the mixture is aged at a temperature equal to or higher than the oxidation reaction temperature, and then reoxidized. After blowing iron gas to grow iron oxyhydroxide crystals, coat the surface of the iron oxyhydroxide with a shape-retaining agent, and then heat-treat at a temperature of 500 to 800 ° C in a non-reducing atmosphere, After that, the method for producing a metal magnetic powder is characterized by heating and reducing with a reducing gas.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP03259173A JP3142324B2 (en) | 1991-10-07 | 1991-10-07 | Manufacturing method of metal magnetic powder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP03259173A JP3142324B2 (en) | 1991-10-07 | 1991-10-07 | Manufacturing method of metal magnetic powder |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0598321A true JPH0598321A (en) | 1993-04-20 |
| JP3142324B2 JP3142324B2 (en) | 2001-03-07 |
Family
ID=17330377
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP03259173A Expired - Fee Related JP3142324B2 (en) | 1991-10-07 | 1991-10-07 | Manufacturing method of metal magnetic powder |
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| Country | Link |
|---|---|
| JP (1) | JP3142324B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5645652A (en) * | 1994-12-13 | 1997-07-08 | Toda Kogyo Corporation | Spindle-shaped magnetic iron-based alloy particles containing cobalt and iron as the main ingredients and process for producing the same |
| US5989516A (en) * | 1994-12-13 | 1999-11-23 | Toda Kogyo Corporation | Spindle-shaped geothite particles |
| JP2007258427A (en) * | 2006-03-23 | 2007-10-04 | Tdk Corp | Magnetic particle and its manufacturing method |
-
1991
- 1991-10-07 JP JP03259173A patent/JP3142324B2/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5645652A (en) * | 1994-12-13 | 1997-07-08 | Toda Kogyo Corporation | Spindle-shaped magnetic iron-based alloy particles containing cobalt and iron as the main ingredients and process for producing the same |
| US5968226A (en) * | 1994-12-13 | 1999-10-19 | Toda Kogyo Corporation | Process of making goethite or iron-based alloy particles |
| US5989516A (en) * | 1994-12-13 | 1999-11-23 | Toda Kogyo Corporation | Spindle-shaped geothite particles |
| JP2007258427A (en) * | 2006-03-23 | 2007-10-04 | Tdk Corp | Magnetic particle and its manufacturing method |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3142324B2 (en) | 2001-03-07 |
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