JPS60221325A - Iron nitride-based ferromagnetic powder excellent in corrosion resistance and its manufacture - Google Patents
Iron nitride-based ferromagnetic powder excellent in corrosion resistance and its manufactureInfo
- Publication number
- JPS60221325A JPS60221325A JP59073066A JP7306684A JPS60221325A JP S60221325 A JPS60221325 A JP S60221325A JP 59073066 A JP59073066 A JP 59073066A JP 7306684 A JP7306684 A JP 7306684A JP S60221325 A JPS60221325 A JP S60221325A
- Authority
- JP
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- Prior art keywords
- iron nitride
- powder
- corrosion resistance
- ferromagnetic powder
- magnetic powder
- Prior art date
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Abstract
Description
【発明の詳細な説明】
〔発明の利用分野〕
本発明は、磁気テープや磁気ディスク等に用いられる窒
化鉄基強磁性粉末ならびにその製造法に係り、特にクロ
ムと窒素またはクロムと酸素および窒素を含有する耐食
性のすぐれた窒化鉄基強磁性粉末およびその製造方法に
関する。Detailed Description of the Invention [Field of Application of the Invention] The present invention relates to an iron nitride-based ferromagnetic powder used for magnetic tapes, magnetic disks, etc. and a method for producing the same. The present invention relates to an iron nitride-based ferromagnetic powder containing excellent corrosion resistance and a method for producing the same.
窒化鉄基強磁性粉末（以下、窒化鉄磁性粉末と略称する
）は、高性能の磁気テープ、ディスクなどに用いられる
磁性粉末として注目されている。Iron nitride-based ferromagnetic powder (hereinafter abbreviated as iron nitride magnetic powder) is attracting attention as a magnetic powder used in high-performance magnetic tapes, disks, and the like.
しかし、窒化鉄磁性粉末は表面活性が大きいために、（
１）空気中で自然発火する、（２）空気中で徐々に酸化
され、時間の経過と共に飽和磁化（σＳ）が劣化する、
などの問題がある。したがって、窒化鉄磁性粉末の耐食
性の向上が必要不可欠の要素となる。窒化鉄磁性粉末の
耐食性を評価する尺度の１つとして、６０℃の温度で、
相対湿度９０％の空気雰囲気中で、１週間放置後のσ６
の維持率が用いられる。この条件は、はぼ３年の加速試
験に相当するが、窒化鉄磁性粉末を磁気テープ等に用い
るためには少なくとも８０％の維持率が望ましい。また
、σ６が大きいという窒化鉄磁性粉末の特徴を生かすた
めには、σ８が８０ｅｍｕ／ｇ以上が好ましく、１０１
００ｅ／ｇ以上がより好ましい。さらに、窒化鉄磁性粉
末は保磁力（Ｈｃ ）が大きく高密度磁気記録に適する
という特徴がある。必要なＨｅは用途によって異なるが
、６０００ ｅ以上のＨｅが好ましく、８０００ｅ以上
がより好ましい。用いる窒化鉄磁性粉末の粒子サイズ、
形状は用途によって異なるが、通常の場合は、粒子の長
軸長０．１〜１．０岬、長軸長と短軸長との比が５〜１
５のものが磁気テープ、ディスクなどの磁気記録媒体用
磁性粉末として適している。さらに、長軸長が０．１〜
０．４ＩＩＩｎのものは雑音レベルが低くなるのでさら
に好ましいＡ
窒化鉄磁性粉末の耐食性処理方法としては、（１）窒化
鉄磁性粉末の表面を酸化する方法、（２）窒化鉄磁性粉
末の表面を特殊な物質（樹脂、金属、金属化合物、非金
属化合物等）で被覆する方法が知られている。」二記の
（１）は、窒化鉄磁性粉末の表面を少量の酸素を含む不
活性ガス雰囲気中などで徐酸化する方法であるが、この
方法では磁気テープ等の媒体ノイズの低減化を目的とし
て窒化鉄磁性粉末を微粒子化すると比表面積が大きくな
るため、大きな粒子の場合と同等の耐食性を維持しよう
とするとσ５を極端に小さくする必要があり、また同等
のσ８を維持しようとすると耐食性が悪くなるという欠
点がある。上記に（２）の方法は窒化鉄磁性粉末の表面
を、樹脂などの特殊な物質で被覆する方法であるが、被
覆物質の選択がむつかしく、表面を特殊な物質で被覆す
ると、その物質によっては磁気テープ等の媒体作成時に
磁性粉末の均一な分散がむずがしくなるという欠点があ
る。However, iron nitride magnetic powder has a high surface activity, so (
1) It spontaneously ignites in the air, (2) It is gradually oxidized in the air, and the saturation magnetization (σS) deteriorates over time.
There are problems such as. Therefore, improving the corrosion resistance of iron nitride magnetic powder is an essential element. As one of the measures for evaluating the corrosion resistance of iron nitride magnetic powder, at a temperature of 60°C,
σ6 after being left for one week in an air atmosphere with relative humidity of 90%
retention rate is used. Although this condition corresponds to an accelerated test of about three years, a retention rate of at least 80% is desirable in order to use the iron nitride magnetic powder in magnetic tapes and the like. In addition, in order to take advantage of the characteristic of iron nitride magnetic powder that σ6 is large, σ8 is preferably 80 emu/g or more, and 101
00e/g or more is more preferable. Furthermore, iron nitride magnetic powder has a large coercive force (Hc) and is suitable for high-density magnetic recording. Although the necessary He differs depending on the application, He of 6000 e or more is preferable, and He of 8000 e or more is more preferable. Particle size of iron nitride magnetic powder used,
The shape varies depending on the application, but usually the long axis length of the particle is 0.1 to 1.0, and the ratio of the long axis length to the short axis length is 5 to 1.
No. 5 is suitable as a magnetic powder for magnetic recording media such as magnetic tapes and disks. Furthermore, the major axis length is 0.1~
A of 0.4IIIn is more preferable because the noise level is lower. Corrosion resistance treatment methods for iron nitride magnetic powder include (1) a method of oxidizing the surface of the iron nitride magnetic powder; (2) a method of oxidizing the surface of the iron nitride magnetic powder; A method of coating with a special substance (resin, metal, metal compound, non-metal compound, etc.) is known. 2. (1) is a method of slowly oxidizing the surface of iron nitride magnetic powder in an inert gas atmosphere containing a small amount of oxygen, but this method is aimed at reducing media noise such as magnetic tape. When iron nitride magnetic powder is made into fine particles, the specific surface area increases, so if you try to maintain the same corrosion resistance as with large particles, you have to make σ5 extremely small, and if you try to maintain the same σ8, the corrosion resistance decreases. The drawback is that it gets worse. Method (2) above is a method of coating the surface of iron nitride magnetic powder with a special substance such as resin, but it is difficult to select the coating substance, and if the surface is coated with a special substance, depending on the substance, A drawback is that it is difficult to uniformly disperse the magnetic powder when producing media such as magnetic tape.
本発明の目的は、−ヒ述の従来技術の問題点を解消し、
飽和磁化および保磁力の大きな、特に磁気テープ、ディ
スク用としてすぐれた耐食性をもつ窒化鉄基強磁性粉末
ならびにその製造方法を提供するにある。The purpose of the present invention is to solve the problems of the prior art described in
An object of the present invention is to provide an iron nitride-based ferromagnetic powder having high saturation magnetization and coercive force, and excellent corrosion resistance especially for use in magnetic tapes and disks, and a method for producing the same.
本発明者らは、０．２〜１ｏ原子％（以下単に％と略称
する）のＣｒを含有する窒化鉄磁性粉末は、特に飽和磁
化および保磁力が大きく、しがも耐食性がすぐれている
ことを種々の実験の結果知見し本発明を完成するに至っ
た。The present inventors have discovered that iron nitride magnetic powder containing 0.2 to 10 at. As a result of various experiments, the present invention was completed.
（１）本発明は、０．２−１０％のＣｒと１．８−３０
％ノＮを含有し、残部が不可避的に混入する不純物およ
びＦｅからなる耐食性のすぐれた窒化鉄磁性粉末を基本
とする。(1) The present invention uses 0.2-10% Cr and 1.8-30%
It is based on iron nitride magnetic powder with excellent corrosion resistance, which contains %N and the remainder is unavoidably mixed impurities and Fe.
（２）本発明は、上記（１）の基本成分の外に１０〜３
０％のＯを含有する耐食性のすぐれた窒化鉄磁性粉末で
ある。(2) In addition to the basic components of (1) above, the present invention provides 10 to 3
Iron nitride magnetic powder with excellent corrosion resistance containing 0% O.
（３）そして本発明は、上記（２）の成分の外に、１０
％以下のＮｊ、 Ｃｏ、 Ｃｕ、 Ａ３ Ｔｉ、 Ｍｏ
、 Ｐ 。(3) In addition to the above component (2), the present invention also provides 10
% or less Nj, Co, Cu, A3 Ti, Mo
, P.
Ｓｎ、Ｚｎ、Ｍｇ、Ｓｉ、Ｗ、Ｂ＋ Ｐｂ、Ｓｂ、Ｍｎ
およびＧｅの１種または２種以上を含有する耐合性のす
ぐれた窒化鉄磁性粉末である。Sn, Zn, Mg, Si, W, B+ Pb, Sb, Mn
It is an iron nitride magnetic powder with excellent resistance to metallization, containing one or more of Ge and Ge.
（４）そして、さらに本発明は、Ｃｒを含有するＦｅ基
合金粉末または、それらの金属酸化物粉末もしくは、そ
れらの金属オキシ水酸化物の粉末の少なくとも１種類を
、Ｈ２またはＨ２を含む雰囲気下で還元するか、もしく
は還元せずして、アンモニアまたはアンモニアを含む雰
囲気下で、窒化処理を行うか、または該窒化処理の後、
徐酸化処理を行なって、耐食性のすぐれた窒化鉄磁性粉
末を製造する方法である。(4) Furthermore, the present invention provides at least one of Fe-based alloy powder containing Cr, metal oxide powder thereof, or powder of metal oxyhydroxide thereof in an atmosphere containing H2 or H2. with or without reduction, nitriding is performed in ammonia or an atmosphere containing ammonia, or after the nitriding,
This is a method for producing iron nitride magnetic powder with excellent corrosion resistance by performing slow oxidation treatment.
本発明の耐食性のすぐれた窒化鉄磁性粉末において、Ｃ
ｒ含有量が０．２〜１０％の範囲がよいのは、０．２％
未満では、耐食性向上効果が少なく、１０％を超える量
では、磁性粉末の飽和磁化が８０ｅｍｕ／ｇ以下と小さ
くなるからであり、Ｃｒの含有量は１〜５％の範囲がよ
り好ましく、さらには１〜３％の範囲が好ましい。また
、Ｃｒは磁性粉末全体に均一に分布していても良いが、
磁性粉末の表面近傍に高濃度のＣｒを存在させれば粉末
内部に均一分布の場合よりも磁性粉末の飽和磁化が大き
くなるのでより好ましい。この磁性粉末の表面近傍に許
容されるＣｒ濃度は最高３０％程度である。In the iron nitride magnetic powder of the present invention with excellent corrosion resistance, C
The preferred r content range is 0.2% to 10%.
If the amount is less than 1%, the effect of improving corrosion resistance will be small, and if the amount exceeds 10%, the saturation magnetization of the magnetic powder will be as small as 80 emu/g or less.The content of Cr is more preferably in the range of 1 to 5%, and A range of 1 to 3% is preferred. Further, Cr may be uniformly distributed throughout the magnetic powder, but
It is more preferable to have a high concentration of Cr in the vicinity of the surface of the magnetic powder because the saturation magnetization of the magnetic powder becomes larger than when Cr is uniformly distributed inside the powder. The maximum Cr concentration allowed near the surface of this magnetic powder is about 30%.
窒化鉄磁性粉末中のＮの含有量は、使用目的ならびにＣ
ｒ量、Ｆｅ以外の添加元素の量によって変化するが、Ｎ
含有量は１８〜３０％の範囲が好ましく、２０〜３０％
の範囲がより好ましい。また、２２〜２８％の範囲がさ
らに好ましい。Ｎ含有量が１８％未満では、金属と窒化
金属に相分離し易いために磁気特性が不安定になり易く
、また耐食性も低下するためである。また、３０％を超
えると飽和磁化が極端に悪くなる。The content of N in the iron nitride magnetic powder depends on the purpose of use and C.
Although it varies depending on the amount of r and the amount of added elements other than Fe, N
The content is preferably in the range of 18 to 30%, and 20 to 30%
The range is more preferable. Moreover, the range of 22 to 28% is more preferable. This is because if the N content is less than 18%, phase separation into metal and metal nitride tends to occur, which tends to make magnetic properties unstable, and also reduces corrosion resistance. Moreover, if it exceeds 30%, the saturation magnetization becomes extremely poor.
次に、窒化鉄磁性粉末の表面を酸化したものは、酸化し
ないものに比べ飽和磁化は若干減少するが耐食性は向上
する。この場合、酸化層の厚さは１０〜５０人で、平均
３０人程度である。０含有量は、磁性粉末全体に対して
、１０〜３０％の範囲が好ましく、１０〜２５％の範囲
がより好ましい。上記の範囲が好ましい理由は、１０％
未満では、耐食性向上効果がほとんどなく、３０％を超
える場合には飽和磁化が小さくなるため゛である。Next, when the surface of the iron nitride magnetic powder is oxidized, the saturation magnetization is slightly reduced compared to the one that is not oxidized, but the corrosion resistance is improved. In this case, the thickness of the oxidized layer is 10 to 50, with an average of about 30. The zero content is preferably in the range of 10 to 30%, more preferably in the range of 10 to 25%, based on the entire magnetic powder. The reason why the above range is preferable is that 10%
If it is less than 30%, there is almost no effect of improving corrosion resistance, and if it exceeds 30%, the saturation magnetization becomes small.
窒化鉄磁性粉末の製造原料としては、
（１）剣状の鉄粉末、ａ−ＦｅＯＯＨ１β−ＦｅＯＯｉ
（、γ−ＦｅＯＯＨ１ａ Ｆ ｅ２０３、Ｆｅ、Ｏ，、
γ−Ｆｅ２０３などの剣状の鉄粉、オキシ水酸化鉄粉末
、酸化鉄粉末、およびそれらのＦｅの一部をＣｒで置換
したもの。Raw materials for producing iron nitride magnetic powder include: (1) Sword-shaped iron powder, a-FeOOH1β-FeOOi
(, γ-FeOOH1a Fe203, Fe, O,,
Sword-shaped iron powder such as γ-Fe203, iron oxyhydroxide powder, iron oxide powder, and those in which part of Fe is replaced with Cr.
（２）剣状の鉄粉末、オキシ水酸化鉄粉末、酸化鉄粉末
等の表面に、Ｃｒを含む金属、酸化物、オキシ酸化物、
水酸化物等を成長、付着、沈着させたもの、
（３）剣状の鉄粉末、オキシ水酸化鉄粉末、酸化鉄粉末
等のＦｅの一部をＣｒと、１０％以下のＮｉ。(2) Metals, oxides, oxyoxides, etc. containing Cr on the surface of sword-shaped iron powder, iron oxyhydroxide powder, iron oxide powder, etc.
(3) Sword-shaped iron powder, iron oxyhydroxide powder, iron oxide powder, etc., in which part of the Fe is Cr and 10% or less of Ni.
Ｇｏ、Ｃｕ、ＡＪ Ｔｉ、Ｍｏ、Ｐ、Ｓｎ、Ｚｎ＋ Ｍ
ｇ。Go, Cu, AJ Ti, Mo, P, Sn, Zn+M
g.
Ｓｉ、Ｗ、Ｂ、Ｐｂ、Ｓｂ、ＭｎおよびＧｅ等の異種元
素で置換したもの、
などを用いることができる。Those substituted with different elements such as Si, W, B, Pb, Sb, Mn, and Ge can be used.
窒化処理時の焼結防止処理剤としては、ＡＡ。AA is used as a sintering prevention treatment agent during nitriding treatment.
Ｓｌｌ Ｔｌｌ Ｃｒ、 Ｓｎ＋ Ｇｅ、 Ｚｎ、 Ｃ
ｕ＋ Ｍｎ、 Ｓｂ＋Ｐｂ、Ｂ等の化合物があるが、Ａ
ｎおよびＳｉ化合物Ｊ−１’ｙ ｄ２１ＸＧ ツク ノ
’ｔ ｌ：ｌｒ Ｉａ １４− Ｍ ｉｎ ＋１ス ↓
÷１ 「） φ１１、 ＾ −ｙ Ｊｗ 山 ＋し１
゜
針状のＦｅ基合金粉末以外の原料を使用する場合には、
窒化に先たち、あらかじめ原料を非還元性雰囲気（空気
、０２、不活性ガス、およびこれらの混合ガス）または
水蒸気を含むＨ２ガスなどの雰囲気中で、４００〜１０
００℃の温度で焼成することが好ましい。原料をあらか
じめ焼成すると良いのは、焼成によってオキシ水酸化物
の脱水時の孔（酸化物も通常オキシ水酸化物から作智り
されるので脱水孔が存在する）が封孔される結果、最終
的に得られる窒化鉄磁性粉末の比表面積が小さくなり耐
食性が向上するためである。Sll Tll Cr, Sn+ Ge, Zn, C
There are compounds such as u+ Mn, Sb+Pb, and B, but A
n and Si compound J-1'y d21XG Tsuku no't l:lr Ia 14- M in +1 s ↓
÷1 ") φ11, ^ -y Jw mountain +shi1
゜When using raw materials other than acicular Fe-based alloy powder,
Prior to nitriding, the raw materials are heated in advance at 400 to 10
Preferably, the firing is carried out at a temperature of 00°C. It is a good idea to pre-calcine the raw materials because the pores during dehydration of the oxyhydroxide are sealed (oxides are usually made from oxyhydroxide, so there are dehydration pores), so that the final This is because the specific surface area of the iron nitride magnetic powder obtained is reduced and the corrosion resistance is improved.
磁性粉末の窒化処理は、２５０〜７００℃の温度範囲で
行うことができるが、３００〜７００℃の温度範囲が生
産性が良く、窒化用ガスの利用効率が高く、かつ窯化鉄
磁性粉末の比表面積が小さくなるために耐食性が向上す
るのでより好ましい。The nitriding treatment of magnetic powder can be carried out at a temperature range of 250 to 700°C, but a temperature range of 300 to 700°C has good productivity, high utilization efficiency of nitriding gas, and It is more preferable because corrosion resistance is improved due to the smaller specific surface area.
また、窒化に先たち、Ｈ２ガス中で還元処理を行なうこ
とが好ましい。あらかじめ還元処理をするとよいのは−
いっｔ−ん学会に全Ｍ４ｋにまでｍ臀されるので、未還
元の酸化物などが無くなり、均一組成の窒化鉄磁性粉末
が得やすいためである。Further, prior to nitriding, it is preferable to perform a reduction treatment in H2 gas. It is better to perform reduction processing in advance -
This is because the iron nitride magnetic powder is reduced to a total M4k at once, so that unreduced oxides and the like are eliminated, making it easier to obtain iron nitride magnetic powder with a uniform composition.
窒化に用いるガスとしては、アンモニアガス、不活性ガ
スで希釈したアンモニアガスまたはＮ２ガスで希釈した
アンモニアガス等をあげることができるが、Ｎ２ガスで
希釈したアンモニアガスが最も好ましい。なお、アンモ
ニアガス含有量は、２０％以上が生産性がよく好ましい
。Examples of the gas used for nitriding include ammonia gas, ammonia gas diluted with an inert gas, or ammonia gas diluted with N2 gas, but ammonia gas diluted with N2 gas is most preferred. Note that an ammonia gas content of 20% or more is preferable for good productivity.
磁性粉末の窒化処理終了後は、
（１）窒化鉄磁性粉末を、エタノール、トルエンまたは
キシレンなどの酸性基を含まない有機溶媒中に懸濁させ
、これに０〜１４０℃の温度で、酸化性ガス（例えば、
空気、空気とＮ、混合ガス等）を吹込むか、
（２）または、窒化鉄磁性粉末を、５００〜５０００ｐ
ｐｍの０２を含む不活性ガス（Ｎ２． Ａｒ、 Ｃ○２
ガス等）中で、０〜１４０℃の温度範囲で熱処理する、
などの方法によって、窒化＃ｉ磁性粉末の表面を徐酸化
して、１０〜３０％の酸素を含有させた窒化鉄磁性粉末
は、酸素を含有させないものに比べて。After nitriding the magnetic powder, (1) suspend the iron nitride magnetic powder in an organic solvent that does not contain acidic groups, such as ethanol, toluene, or xylene, and oxidize it at a temperature of 0 to 140°C. gas (e.g.
(2) Or, add 500 to 5000 p of iron nitride magnetic powder.
Inert gas containing pm 02 (N2. Ar, C○2
heat treatment in a temperature range of 0 to 140°C (gas, etc.),
Iron nitride magnetic powder containing 10 to 30% oxygen by slowly oxidizing the surface of nitrided #i magnetic powder using the method described above is compared to one containing no oxygen.
飽和磁化（σＳ）は若干小さくなるが、耐食性が更に向
上するので好ましい。なお、徐酸化処理の温度について
は、酸化メディアによって異なってくるが、０〜１４０
℃の温度範囲が良く、０℃未満では酸化速度が遅く磁性
粉末の生産性が上がらず、また１４０℃を超えると、酸
化が急激に起り粉末全体が酸化されσ６が極端に低下す
る。好ましい温度範囲は５０〜１２０℃で、９０℃前後
がさらに好ましν１゜
第１図に、Ｃｒを含有するα−ＦｅＯＯＨに水ガラス（
Ｎ ａ ２ Ｓ ｉＯ３）で、焼結防止処理を施し、こ
れを４５０℃の温度でＨ，ガス還元した後、アンモニア
とＮ２の混合比が３＝１の混合ガスを用い、約４００°
Ｃの温度で窒化処理を行なって得た窒化鉄磁性粉末を、
キシレン溶媒中に浸漬して、その後これを空気中で自然
乾燥させた窒化鉄磁性粉末（長軸長；約１０．４７ｍ、
針状比；約８）のＣｒ含有量と、保磁力（Ｈｃ）、飽和
磁化（σ５）ならびに耐食性との関係を示す。Although the saturation magnetization (σS) becomes slightly smaller, corrosion resistance is further improved, which is preferable. The temperature of the gradual oxidation treatment varies depending on the oxidation media, but is between 0 and 140℃.
A temperature range of 0.degree. C. is preferable; below 0.degree. C., the oxidation rate is slow and the productivity of the magnetic powder does not increase; when it exceeds 140.degree. C., oxidation occurs rapidly and the entire powder is oxidized, resulting in an extremely low .sigma.6. The preferred temperature range is 50 to 120°C, more preferably around 90°C.
After applying sintering prevention treatment with Na 2 SiO3) and reducing it with H gas at a temperature of 450°C, it was heated at approximately 400°C using a mixed gas with a mixture ratio of ammonia and N2 of 3=1.
Iron nitride magnetic powder obtained by nitriding at a temperature of C,
Iron nitride magnetic powder (long axis length: approximately 10.47 m,
The relationship between the Cr content with an acicular ratio of about 8), coercive force (Hc), saturation magnetization (σ5), and corrosion resistance is shown.
曲線１は、Ｃｒ含有窒化鉄磁性粉末の保磁力（Ｉ（ｃ）
、曲線２はその飽和磁化（σＳ）、曲線３はＣｒ含有
窒化鉄磁性粉末を６０°Ｃ１相対湿度（ＲＨ）９０％の
空気中に１週間放置した場合の飽和磁化の維持率（σ１
／σ５）を示すグラフである。Curve 1 shows the coercive force (I(c)) of the Cr-containing iron nitride magnetic powder.
, curve 2 shows its saturation magnetization (σS), and curve 3 shows its saturation magnetization retention rate (σ1
/σ5).
なお、これらの窒化鉄磁性粉末は、いずれも約８％の酸
素と約２３％の窒素を含有していた。第１図かられかる
ように、０．２〜１０％のＣｒを含有する窒化鉄磁性粉
末は、Ｈｃが８０００ｅ以上、σ８が１０１００ｅ／ｇ
以」二と大きく、しかも飽和磁化の維持率（σ、／σ、
）は８０％以」―で、耐食性が良いことを示している。Note that each of these iron nitride magnetic powders contained about 8% oxygen and about 23% nitrogen. As can be seen from Figure 1, iron nitride magnetic powder containing 0.2 to 10% Cr has an Hc of 8000e or more and a σ8 of 10100e/g.
The retention rate of saturation magnetization (σ, /σ,
) is 80% or higher, indicating good corrosion resistance.
第２図に、第１図と同様な方法で、１％のＣｒと２２％
のＮを含有する窒化鉄磁性粉末を作製し、その後、空気
中で自然乾燥をする代りに、窒化鉄磁性粉末のキシレン
懸濁液中に空気とＮ２との混合ガス（空気とＮ２の比は
１：１）を吹込み、０〜１４０℃の温度で徐酸化したＣ
ｒ含有窒化鉄磁性粉末の酸素含有量と、飽和磁化（σＳ
）ならび゛に耐食性との関係を調へたグラフである。第
２図中の曲線４は飽和磁化（σ５）、曲線５はＣｒ含有
窒化鉄磁性粉末を６０’Ｃ１相対湿度９０％の空気中に
１週間放置後の飽和磁化の維持率（σｔ／σ６）を示し
たものである。なお、第２図中のム印（曲線４）と■印
（曲線５）は、空気中で自然乾燥したＣｒ含有窒化鉄磁
性粉末である。第２図から明らかなごとく、徐酸化によ
って、１０〜３０％の酸素を含有させたＣｒ含有窒化鉄
磁性粉末のσ８は、空気中で自然乾燥（自然酸化）させ
た試料（ムおよび間開のもので、○含有量約８％）に比
べて、σ５は若干減少するが１．３０ｅｍｕ／ｇ以上の
実用的な値をもち、σ５の維持率（σ、／σ、）も犬き
く耐食性が良い。Figure 2 shows 1% Cr and 22% Cr in the same manner as in Figure 1.
Instead of producing iron nitride magnetic powder containing N and then drying it naturally in air, a mixed gas of air and N2 (the ratio of air and N2 is 1:1) and slowly oxidized at a temperature of 0 to 140°C.
Oxygen content of r-containing iron nitride magnetic powder and saturation magnetization (σS
) and its relationship with corrosion resistance. Curve 4 in Figure 2 is the saturation magnetization (σ5), and curve 5 is the retention rate of saturation magnetization (σt/σ6) after leaving Cr-containing iron nitride magnetic powder in air at 60'C1 relative humidity of 90% for one week. This is what is shown. In addition, the mark (curve 4) and the mark (curve 5) in FIG. 2 are Cr-containing iron nitride magnetic powders that were naturally dried in air. As is clear from Fig. 2, the σ8 of the Cr-containing iron nitride magnetic powder containing 10 to 30% oxygen by slow oxidation is different from that of the sample naturally dried in air (natural oxidation). Although the σ5 is slightly reduced compared to the ○ content of about 8%, it has a practical value of 1.30 emu/g or more, and the σ5 maintenance rate (σ, /σ,) also has excellent corrosion resistance. good.
［発明の実施例〕 以下に、実施例によって本発明の詳細な説明する。[Embodiments of the invention] Hereinafter, the present invention will be explained in detail by way of examples.
（実施例１）
脱イオン水６０ｍ Ｑに、Ｘモル（Ｘ ； Ｏ−０，０
９）のＣｒ５ｏ４”７Ｈ２０と、（０，０６−Ｘ）モル
のＦｅＳＯ４・７Ｈ２０を溶解した。ついで、該溶液を
攪伴しながら、脱イオン水１００ｍＱに溶解し、０．５
モルのＮａＯＨを徐々に加えＣｒｙＦｅｔ−ｙ（ＯＨ）
ｚ （Ｙ ； ０〜０．１５）のスラリーを作製した。(Example 1) In 60 m of deionized water, X moles (X; O-0,0
9) Cr5o4"7H20 and (0,06-X) mol of FeSO4.7H20 were dissolved. Then, while stirring the solution, it was dissolved in 100 mQ of deionized water, and 0.5
Gradually add mol of NaOH to create CryFet-y(OH)
A slurry of z (Y; 0 to 0.15) was prepared.
このスラリーを５０℃まで加温したのち、Ｌｏｏｍ Ｑ
／ ｍｉｎの空気吹込みを行ない、４状のａ−Ｃｒｙ
Ｆｅ、−ｙｏＯＨ（Ｙ ；０〜０．１５）を作製した。After heating this slurry to 50℃, Loom Q
/ min of air was blown into the 4-shaped a-Cry.
Fe, -yoOH (Y; 0-0.15) was prepared.
このようにして作製した（ｚ Ｃｒ ｙ Ｆ ｅ １−
ｙ ＯＯＨに、０．５ｇの水ガラス（ＮａｚＳｊＯ３
）を含む水溶液を加え、１時間攪拌後中和し、生成した
懸濁状の粉末を濾別した。この粉末０．３ｇを、ステン
レス製ボート（長さ３０＋ｎｍ、幅１５ｎｗｎ、高さ７
ｎ＋ｎ＋）に入れて、内径２０Ｔｔｎの石英管に挿入し
、電気炉を用いて８００℃の温度で、３時間加熱して脱
水ならびに封孔処理を行なった。ついで、室温に冷却し
てＮ２ガスで反応容器内を置換した後、Ｎ、の送入を止
め３．５Ｑ／ｍｉｎの割合でＨ，ガスを送入した。再び
４５０℃の温度まで昇温し、４５０°Ｃで３時間Ｎ２還
元して針状のＣｒｙＦｅ、−ｘ （Ｙ ；０〜０．１５
）を作製し、Ｎ２気流中で４００℃まで冷却した後、雰
囲気ガスをアンモニアとＮ２の混合ガス（ＮＨ３／Ｎ２
＝ｌ／３）に切り替え４００°Ｃで５時間窒化処理を行
なった。窒化処理終了後、Ｎ２気流中でキシレン溶媒中
に浸漬し懸濁させた。このＣｒ含有窒化鉄磁性粉末のキ
シレン懸濁物を室温の空気中で乾燥して、磁気特性の測
定ならびに耐食性を評価した。磁気特性の測定は最高磁
場１ＯＫＯｅの条件下で行なった。その結果を、第１図
のＣｒ含有量と磁気特性ならびに耐食性との関係を示す
グラフに示した。図から明らかなごとく、Ｃｒの含有量
を０．２〜１０％の範囲にすることによって、保磁力（
Ｈｃ）１が８０００ ｅ以上、飽和磁化（σＳ）２が１
０１００ｅ／ｇ以上と大きく、かつ飽和磁化の維持率（
σ１／σ５）３も８０％以上と大きく、耐食性のよい窒
化鉄磁性粉末が得られた。Produced in this way (z Cry Fe 1-
y OOH, add 0.5 g of water glass (NazSjO3
) was added thereto, and after stirring for 1 hour, the mixture was neutralized, and the resulting suspended powder was filtered off. 0.3g of this powder was added to a stainless steel boat (length 30+nm, width 15nwn, height 7nm).
n+n+), inserted into a quartz tube with an inner diameter of 20 Ttn, and heated in an electric furnace at 800° C. for 3 hours to perform dehydration and sealing. Then, after cooling to room temperature and purging the inside of the reaction vessel with N2 gas, the supply of N was stopped and H gas was supplied at a rate of 3.5 Q/min. The temperature was raised again to 450°C, and N2 was reduced at 450°C for 3 hours to form acicular CryFe, -x (Y; 0 to 0.15
) was prepared and cooled to 400°C in a N2 stream, and then the atmospheric gas was changed to a mixed gas of ammonia and N2 (NH3/N2
=l/3) and nitriding treatment was performed at 400°C for 5 hours. After the nitriding treatment was completed, it was immersed and suspended in a xylene solvent in a N2 stream. This xylene suspension of the Cr-containing iron nitride magnetic powder was dried in air at room temperature, and its magnetic properties and corrosion resistance were evaluated. The magnetic properties were measured under conditions of a maximum magnetic field of 1 OKOe. The results are shown in the graph of FIG. 1 showing the relationship between Cr content, magnetic properties, and corrosion resistance. As is clear from the figure, by setting the Cr content in the range of 0.2 to 10%, the coercive force (
Hc)1 is 8000 e or more, saturation magnetization (σS)2 is 1
0100e/g or more, and the retention rate of saturation magnetization (
σ1/σ5)3 was also as large as 80% or more, and iron nitride magnetic powder with good corrosion resistance was obtained.
（実施例２）
ＣｒＳＯ４・７Ｈ２０の量を０．０００６モル、ＦｅＳ
Ｏ４・７Ｈ２０の量を０．０５９４モルとしたことを除
き、他の条件は実施例１と同様にしてＣｒ含有窒化鉄磁
性粉末を作製し、これを窒素気流中で溶媒のキシレン中
に浸漬した。このＣｒ含有窒化鉄磁性粉末のキシレン懸
濁液に、空気−Ｎ２混合ガスを吹込み、０〜１４０℃の
温度範囲で徐酸化処理を行なった。この窒化鉄磁性粉末
の酸素含有量と飽和磁化（σ、）飽和磁化の維持率（σ
ｔ／σＳ）ならびに耐食性との関係を第２図に示す。図
から明らかなごとく、酸化処理によって、酸素含有量を
１０〜３０％の範囲としたＣｒ含有窒化鉄磁性粉末は、
σｓ４は、空気中で自然乾燥した試料（ム印（σｓ）、
■印（σ、／σ、）、Ｏ含有量８％）に比べて若干減少
するが１．３０ｅｍｕ／ｇ以上と実用的な値をもち、σ
ｔ／σ、５が大きくなり耐食性がよい。(Example 2) The amount of CrSO4.7H20 was 0.0006 mol, FeS
A Cr-containing iron nitride magnetic powder was prepared in the same manner as in Example 1 except that the amount of O4.7H20 was set to 0.0594 mol, and this was immersed in xylene as a solvent in a nitrogen stream. . Air-N2 mixed gas was blown into the xylene suspension of the Cr-containing iron nitride magnetic powder, and gradual oxidation treatment was performed in a temperature range of 0 to 140°C. Oxygen content and saturation magnetization (σ,) of this iron nitride magnetic powder, retention rate of saturation magnetization (σ
t/σS) and corrosion resistance are shown in FIG. As is clear from the figure, the Cr-containing iron nitride magnetic powder whose oxygen content is in the range of 10 to 30% by oxidation treatment is
σs4 is the sample naturally dried in the air (Mu mark (σs),
Although it is slightly decreased compared to the mark (σ, /σ, ), O content 8%), it has a practical value of 1.30 emu/g or more, and σ
t/σ, 5 becomes large and corrosion resistance is good.
（実施例３）
針状のα−ＦｅＯＯＨの懸濁液に、ＣｒＳＯ４とＦｅＳ
Ｏ４の混合塩を添加して、Ｎ ａ ＯＨで中和して、釘
状のα−ＦｅＯＯＨ表面に、１５％のＣｒと残部がＦｅ
の混合水酸化物を沈着させたことを除き、他の条件は実
施例１と同様な方法で、３％のＣｒを含有する剣状窒化
鉄磁性粉末を作製した。第１表に飽和磁化（σ、）と耐
食性評価の結果を示す。(Example 3) CrSO4 and FeS were added to a suspension of acicular α-FeOOH.
A mixed salt of O4 was added and neutralized with NaOH to form a nail-shaped α-FeOOH surface with 15% Cr and the balance Fe.
A sword-shaped iron nitride magnetic powder containing 3% Cr was prepared in the same manner as in Example 1 except that a mixed hydroxide of 3% was deposited. Table 1 shows the saturation magnetization (σ,) and the results of corrosion resistance evaluation.
第１表Ｎｏ、１は、Ｃｒの分布が表面に存在する場合（
本実施例）の結果を示し、同表Ｎｏ、２は、実施例１と
同じ方法で作製した粉末内部にＣｒ均一固溶（均一分布
）の窒化鉄磁性粉末（Ｃｒ；３％）の耐食性評価結果で
ある。第１表から明らかなごとく、表面にＣｒを分布さ
せた窒化鉄磁性粉末は、Ｃｒを粉末内部に均一分布させ
た磁性粉末よりもσ８が大きく、耐食性も若干良い。Table 1 No. 1 shows that when Cr distribution exists on the surface (
Table No. 2 shows the results of this example), and Table No. 2 shows the corrosion resistance evaluation of iron nitride magnetic powder (Cr; 3%) with Cr uniform solid solution (uniform distribution) inside the powder prepared by the same method as Example 1. This is the result. As is clear from Table 1, the iron nitride magnetic powder with Cr distributed on its surface has a larger σ8 and slightly better corrosion resistance than the magnetic powder with Cr uniformly distributed inside the powder.
（実施例４）
実施例１と同様な方法で、Ｃｒを１％、Ｎを２０％含有
する窒化鉄磁性粉末を作製した。ついで、第２表に示す
２００〜１１００００ｐｐの酸素（０２）を含有する窒
素（Ｎ２）ガスを９０℃の温度で通気し、窒化鉄磁性粉
末を酸化した。第２表に、酸化に使用したＮ２ガス中の
０２濃度と反応時間、飽和磁化（σ。）、飽和磁化の維
持率（σｔ／σ５）ならびに耐食性との関係を示す。第
２表から明らかなごとく、０２濃度が５００．２０００
．５０００ｐｐｍである雰囲気で酸化したものは、空気
中で自然乾燥した試料れもσ５か１２０ｅｍｕ／ｇ以上
で実用的な値をもち、σｔ／σ５は大きく耐食性がよい
。一方、２００ｐｐｍの０２を含有する酸化雰囲気を使
用した場合は、酸化に要する反応時間は２０ｈと極端に
長く、１１００００ｐｐの０２濃度の場合には試料全体
が酸化されてしまい実用性が無いことがわかる。このこ
とから、５００〜５０００ｐｐｍの０２を含有するガス
で酸化することにより、σ９は若干小さくなるが耐食性
にすぐれた窒化鉄磁性粉末が得られることがわかる。(Example 4) Iron nitride magnetic powder containing 1% Cr and 20% N was produced in the same manner as in Example 1. Next, nitrogen (N2) gas containing 200 to 110,000 pp of oxygen (02) as shown in Table 2 was passed through at a temperature of 90 DEG C. to oxidize the iron nitride magnetic powder. Table 2 shows the relationship between the 02 concentration in the N2 gas used for oxidation, reaction time, saturation magnetization (σ), retention rate of saturation magnetization (σt/σ5), and corrosion resistance. As is clear from Table 2, the 02 concentration is 500.2000
．． The sample oxidized in an atmosphere with a concentration of 5000 ppm has a practical value of σ5 of 120 emu/g or more even in the case of a sample air-dried in air, and has a large σt/σ5 and good corrosion resistance. On the other hand, when using an oxidizing atmosphere containing 200 ppm of 02, the reaction time required for oxidation is extremely long, 20 hours, and when the 02 concentration is 110,000 ppm, the entire sample is oxidized, indicating that it is not practical. . From this, it can be seen that by oxidizing with a gas containing 500 to 5000 ppm of 02, iron nitride magnetic powder with excellent corrosion resistance can be obtained although σ9 becomes slightly smaller.
なお、本実施例４と同じ成分のものに、Ｎｉを１０％添
加した場合についてテストした結果、磁気特性および耐
食性は、本実施例に比べて多少よくなる程度であったが
、Ｎｉの添加によって、特に針状の窒化鉄磁性粉末がつ
くり易く、成形性がよくなることを発明者らは実験によ
って確認している。In addition, as a result of testing a case in which 10% Ni was added to the same composition as in this Example 4, the magnetic properties and corrosion resistance were only slightly improved compared to this example, but the addition of Ni In particular, the inventors have confirmed through experiments that acicular iron nitride magnetic powder is easy to produce and has good moldability.
（実施例５）
アンモニアと水素の混合ガスである窒化処理ガス中のア
ンモニアの含有量を変化（１０〜１００容積％）させて
、実施例１と同様な方法で、２％のＣｒを含有し、窒素
含有量の異なる窒化鉄磁性粉末を作製した。第３表に、
窒素含有量と磁気特性の関係を示す。表から明らかなご
とく、窒化鉄磁性粉末の窒素含有量を１８〜３０％の範
囲にすることによって、飽和磁化（σ５）が大きく耐食
性のよい窒化鉄磁性粉末が得られる。一方、窒素含有量
が１５％の窒化鉄磁性粉末は耐食性が悪く、また窒素含
有量が３５％のものはσ８が小さい。(Example 5) The content of ammonia in the nitriding gas, which is a mixed gas of ammonia and hydrogen, was varied (10 to 100% by volume), and 2% Cr was added in the same manner as in Example 1. , we prepared iron nitride magnetic powders with different nitrogen contents. In Table 3,
The relationship between nitrogen content and magnetic properties is shown. As is clear from the table, by setting the nitrogen content of the iron nitride magnetic powder in the range of 18 to 30%, iron nitride magnetic powder with a large saturation magnetization (σ5) and good corrosion resistance can be obtained. On the other hand, iron nitride magnetic powder with a nitrogen content of 15% has poor corrosion resistance, and one with a nitrogen content of 35% has a small σ8.
以上のように、０．２〜１０％のＣｒと１８〜３０％の
窒素を含有する窒化鉄磁性粉末は、飽和磁化が大きく、
かつ耐食性の良いことがわかる。また、上記の窒化鉄磁
性粉末を徐酸化して、酸素含有量を１０〜３０％の範囲
にすることによって、飽和磁化は多少減少するが、いず
れもσ５が１０１００ｅ／ｇ以上と実用的な値をもち、
σ、の維持率も大きくなり耐食性にすぐれていることが
わかる。As described above, iron nitride magnetic powder containing 0.2 to 10% Cr and 18 to 30% nitrogen has a large saturation magnetization.
It can also be seen that it has good corrosion resistance. In addition, by slowly oxidizing the above-mentioned iron nitride magnetic powder and adjusting the oxygen content to a range of 10 to 30%, the saturation magnetization decreases somewhat, but in both cases, σ5 is 10,100 e/g or more, which is a practical value. have,
It can be seen that the retention rate of σ is also large, indicating excellent corrosion resistance.
なお、本発明の実施例には示さなかったが、１０％以下
のＣｏ、 Ｃｕ、Δｎ、 Ｔｉ＋ Ｍｏ、 Ｐ＋ Ｓｎ
、 Ｚｎ。Although not shown in the examples of the present invention, 10% or less of Co, Cu, Δn, Ti+ Mo, P+ Sn
, Zn.
Ｍｇ＋ Ｓｉｔ Ｗ、Ｂ、Ｐｂ、Ｓｂ、Ｍｎ、Ｇｅなど
を含有させた窒化鉄磁性粉末においても同等の磁気特性
ならびに耐食性が得られることを、発明者らは種々テス
トの結果確認している。The inventors have confirmed through various tests that similar magnetic properties and corrosion resistance can be obtained with iron nitride magnetic powder containing Mg+ Sit W, B, Pb, Sb, Mn, Ge, etc.
以上詳細に説明したごとく、本発明による磁性粉末は、
保磁力（Ｈｃ）がＢｏｏ Ｏｅ以上、飽和磁化（σＳ）
が１０１００ｅ／ｇ以上と大きく、かつ飽和磁化の維持
率（σｔ／σ５）が８０％以上というすぐれた耐食性を
もつ、Ｃｒ含有窒化鉄基強磁性粉末であって、磁気テー
プ、ディスクなどの磁気記録媒体用の高性能な磁性粉末
として、その実用的価値は大きい。As explained in detail above, the magnetic powder according to the present invention is
Coercive force (Hc) is Boo Oe or more, saturation magnetization (σS)
It is a Cr-containing iron nitride-based ferromagnetic powder that has a large magnetization of 10,100 e/g or more and a saturation magnetization retention rate (σt/σ5) of 80% or more, which is excellent in corrosion resistance. Its practical value is great as a high-performance magnetic powder for media.
第１図は、本発明による窒化鉄基強磁性粉末のＣｒ含含
有上保磁力、飽和磁化ならびに耐食性との関係を示すグ
ラフ、第２図は本発明による窒化鉄基強磁性粉末のＯ含
有量と飽和磁化ならびに耐食性との関係を示すグラフで
ある。
代理人弁理士 中 村 純之助
牙１ 図
Ｃｒの含、！） 憚゛号２）
１−２ 図
鉱圭含廟量 （原子％）
第１頁の続き
［相］Ｉｎｔ、Ｃ１，’ 識別記号 庁内整理届う１９
−＜
５０− Ｅ
３５４−乏
号
、に
：Ｄ
：ＥFIG. 1 is a graph showing the relationship between Cr-containing coercive force, saturation magnetization, and corrosion resistance of the iron nitride-based ferromagnetic powder according to the present invention, and FIG. 2 is a graph showing the O content of the iron nitride-based ferromagnetic powder according to the present invention. 2 is a graph showing the relationship between saturated magnetization and corrosion resistance. Agent Patent Attorney Junnosuke Nakamura 1 Includes Figure Cr! ) 憚゛issue 2) 1-2 Figure Mineral content (atomic %) Continuation of page 1 [Phase] Int, C1,' Identification symbol Internal organization report 19
-< 50- E 354-Shogo, ni:D:E
Claims (1)
Ｎを含有し、残部が不可避的に混入する不純物およびＦ
ｅからなることを特徴とする耐食性のすぐれた窒化鉄基
強磁性粉末。 ２、窒化鉄基強磁性粉末の組成が、原子％で、０．２〜
１０％（７） Ｃｒ、１８−３０％（７）Ｎと１０−３
０％（７）Ｏを含有し、残部が不可避的に混入する不純
物およびＦｅからなることを特徴とする特許請求の範囲
第１項記載の窒化鉄基強磁性粉末。 ３、窒化鉄基強磁性粉末の組成が、原子％で、０．２〜
１０％（７）Ｃｒ、１８−３０％１７１ Ｎ ト１０−
３０％のＯを含有し、かつ１０％以下のＮｉ、 ｃｏ、
ＣｕｒΔＪ Ｔｉ。 Ｍｏ、ｐ、Ｓｎ、Ｚｎ、Ｍｇｌ ｓｉ、ｗ、Ｂｌ ｐｂ
。 Ｓｂ、Ｍ口およびＧｅの１種または２種以上を含有し、
残部が不可避的に混入する不純物およびＦｅからなるこ
とを特徴とする特許請求の範囲第２項記載の窒化鉄基強
磁性粉本。 ４、Ｃｒを含有するＦｅ基合金粉末または、それらの金
属酸化物粉末もしくは、それらの金属オキシ水酸化物粉
末の少なくとも１種類を、Ｈ２また元せずして、アンモ
ニアまたはアンモニアを含む雰囲気下において、２５０
〜７００°Ｃの温度範囲で窒化処理を行うか、または該
窒化処理の後に、徐酸化処理をほどこすことによって耐
食性のすぐれた窒化鉄基強磁性粉末を製造する方法。 ５、窒化鉄基強磁性粉末の徐酸化処理が、酸性基をもた
ない有機溶媒中に、上記の窒化鉄基強磁性粉末を懸濁し
、該懸濁液に酸化性のガスを吹込むことを特徴とする特
許請求の範囲第４項記載の窒化鉄基強磁性粉末の製造方
法。 ６、窒化鉄基強磁性粉末の徐酸化処理が、上記の窒化鉄
基強磁性粉末を、５００〜５０００ｐｐｍの０２を含む
不活性雰囲気中で行なうことを特徴とする特許請求の範
囲第４項記載の窒化鉄基強磁性粉末の製造方法。[Claims] 1. Contains 0.2-10% Cr and 18-30% N in atomic %, with the remainder being unavoidably mixed impurities and F
An iron nitride-based ferromagnetic powder with excellent corrosion resistance characterized by comprising e. 2. The composition of the iron nitride-based ferromagnetic powder is 0.2 to atomic percent.
10% (7) Cr, 18-30% (7) N and 10-3
The iron nitride-based ferromagnetic powder according to claim 1, characterized in that it contains 0% (7) O, and the remainder consists of unavoidably mixed impurities and Fe. 3. The composition of the iron nitride-based ferromagnetic powder is 0.2 to atomic percent.
10%(7)Cr, 18-30%171N
Contains 30% O and 10% or less Ni, co,
CurΔJTi. Mo, p, Sn, Zn, Mgl si, w, Bl pb
. Contains one or more of Sb, M and Ge,
3. The iron nitride-based ferromagnetic powder according to claim 2, wherein the remainder consists of unavoidably mixed impurities and Fe. 4. At least one type of Fe-based alloy powder containing Cr, metal oxide powder thereof, or metal oxyhydroxide powder thereof is heated in an atmosphere containing ammonia or ammonia without H2 or the like. , 250
A method for producing iron nitride-based ferromagnetic powder with excellent corrosion resistance by performing nitriding treatment in a temperature range of ~700°C, or by performing gradual oxidation treatment after the nitriding treatment. 5. Gradual oxidation treatment of iron nitride-based ferromagnetic powder involves suspending the above-mentioned iron nitride-based ferromagnetic powder in an organic solvent that does not have acidic groups, and blowing an oxidizing gas into the suspension. A method for producing iron nitride-based ferromagnetic powder according to claim 4, characterized in that: 6. The slow oxidation treatment of the iron nitride-based ferromagnetic powder is performed in an inert atmosphere containing 500 to 5000 ppm of 02. A method for producing iron nitride-based ferromagnetic powder.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59073066A JPS60221325A (en) | 1984-04-13 | 1984-04-13 | Iron nitride-based ferromagnetic powder excellent in corrosion resistance and its manufacture |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59073066A JPS60221325A (en) | 1984-04-13 | 1984-04-13 | Iron nitride-based ferromagnetic powder excellent in corrosion resistance and its manufacture |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS60221325A true JPS60221325A (en) | 1985-11-06 |
Family
ID=13507592
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59073066A Pending JPS60221325A (en) | 1984-04-13 | 1984-04-13 | Iron nitride-based ferromagnetic powder excellent in corrosion resistance and its manufacture |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60221325A (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60251513A (en) * | 1984-05-24 | 1985-12-12 | Konishiroku Photo Ind Co Ltd | Magnetic recording medium |
| JPS6217101A (en) * | 1985-07-17 | 1987-01-26 | Kanto Denka Kogyo Kk | Treatment of magnetic metallic powder |
| JPS62271403A (en) * | 1986-05-20 | 1987-11-25 | Taiyo Yuden Co Ltd | Nitrided iron system magnetic powder |
| JPS644001A (en) * | 1987-06-26 | 1989-01-09 | Taiyo Yuden Kk | Manufacture of magnetic powder for magnetic recording medium |
| JP2005268389A (en) * | 2004-03-17 | 2005-09-29 | Dowa Mining Co Ltd | Iron-nitride magnetic powder and its manufacturing method |
| WO2007145301A1 (en) * | 2006-06-14 | 2007-12-21 | Dowa Electronics Materials Co., Ltd. | Iron nitride-based magnetic powder, process for producing the same, and magnetic recording medium |
| JP2015507354A (en) * | 2011-12-15 | 2015-03-05 | ケース ウェスターン リザーヴ ユニヴァーシティ | Rare earth element-free nitride magnet obtained by transition and method for producing the same |
| US10867730B2 (en) | 2011-12-15 | 2020-12-15 | Case Western Reserve University | Transformation enabled nitride magnets absent rare earths and a process of making the same |
-
1984
- 1984-04-13 JP JP59073066A patent/JPS60221325A/en active Pending
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60251513A (en) * | 1984-05-24 | 1985-12-12 | Konishiroku Photo Ind Co Ltd | Magnetic recording medium |
| JPS6217101A (en) * | 1985-07-17 | 1987-01-26 | Kanto Denka Kogyo Kk | Treatment of magnetic metallic powder |
| JPH0557321B2 (en) * | 1985-07-17 | 1993-08-23 | Kanto Denka Kogyo Kk | |
| JPS62271403A (en) * | 1986-05-20 | 1987-11-25 | Taiyo Yuden Co Ltd | Nitrided iron system magnetic powder |
| JPS644001A (en) * | 1987-06-26 | 1989-01-09 | Taiyo Yuden Kk | Manufacture of magnetic powder for magnetic recording medium |
| JP2005268389A (en) * | 2004-03-17 | 2005-09-29 | Dowa Mining Co Ltd | Iron-nitride magnetic powder and its manufacturing method |
| JP4534059B2 (en) * | 2004-03-17 | 2010-09-01 | Ｄｏｗａエレクトロニクス株式会社 | Iron nitride magnetic powder and method for producing the same |
| WO2007145301A1 (en) * | 2006-06-14 | 2007-12-21 | Dowa Electronics Materials Co., Ltd. | Iron nitride-based magnetic powder, process for producing the same, and magnetic recording medium |
| JP2007335592A (en) * | 2006-06-14 | 2007-12-27 | Dowa Electronics Materials Co Ltd | Iron nitride magnetic powder and its manufacturing method and magnetic recording medium |
| JP2015507354A (en) * | 2011-12-15 | 2015-03-05 | ケース ウェスターン リザーヴ ユニヴァーシティ | Rare earth element-free nitride magnet obtained by transition and method for producing the same |
| US9997285B2 (en) | 2011-12-15 | 2018-06-12 | Case Western Reserve University | Transformation enabled nitride magnets absent rare earths and a process of making the same |
| US10867730B2 (en) | 2011-12-15 | 2020-12-15 | Case Western Reserve University | Transformation enabled nitride magnets absent rare earths and a process of making the same |
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