JPS61154013A - Manufacture of needle iron fine particle for magnetic recording - Google Patents

Manufacture of needle iron fine particle for magnetic recording

Info

Publication number
JPS61154013A
JPS61154013A JP59273709A JP27370984A JPS61154013A JP S61154013 A JPS61154013 A JP S61154013A JP 59273709 A JP59273709 A JP 59273709A JP 27370984 A JP27370984 A JP 27370984A JP S61154013 A JPS61154013 A JP S61154013A
Authority
JP
Japan
Prior art keywords
fine particles
powder
iron
magnetic
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.)
Pending
Application number
JP59273709A
Other languages
Japanese (ja)
Inventor
Kazufuyu Sudou
須藤 和冬
Kazufumi Oshima
一史 大島
Kimiteru Tagawa
公照 田川
Shigeo Koba
繁夫 木場
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsui Toatsu Chemicals Inc
Original Assignee
Mitsui Toatsu Chemicals Inc
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Mitsui Toatsu Chemicals Inc filed Critical Mitsui Toatsu Chemicals Inc
Priority to JP59273709A priority Critical patent/JPS61154013A/en
Publication of JPS61154013A publication Critical patent/JPS61154013A/en
Pending legal-status Critical Current

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  • Hard Magnetic Materials (AREA)
  • Paints Or Removers (AREA)
  • Manufacture Of Metal Powder And Suspensions Thereof (AREA)
  • Magnetic Record Carriers (AREA)

Abstract

PURPOSE:To obtain the magnetic metal fine particles which is extraminute magnetic metal fine particles and in which secondary aggregates are extremely diminished and is capable of easy compounding of the highly dispersible mag netic coating compositions by milling the surface denaturated iron oxyhydroxide or iron oxide till 90% or over of secondary aggregates of which pass the screen of 100 mesh particle degree followed by gas-phase catalytic reduction to make them ferromagnetic iron fine particles. CONSTITUTION:A specific surface area 20-150m<2>/gr. of alpha-iron oxyhydroxide or alpha-iron oxyhydroxide in which at least one element selected out of Al. Ti, Cr, Mn, Co, Ni, Zn and etc. coprecipitates is coated with at least one element selected out of B, Al, Si, P, Ti, Zn, Cr, Mn, Co, Ni, Cu, Zr, Sn, Pb, Ca, Ba and etc. Then the dried surface denaturated alpha-iron oxyhydroxide is milled to compound the powder 90% of secondary aggregate of which pass the screen of 100 mesh, more preferably, 200 mesh particle degree. If necessary, calcination at 300-800 deg.C is done to make the powder the surface denaturated alpha-iron oxide, after which that is subjected to the gas-phase catalytic reduction at 300-500 deg.C by use of a reducing gas consisting of hydrogen gas.

Description

【発明の詳細な説明】 〈産業上の利用分野〉 本発明ば、音声及び映像を主とした高密度磁気記碌媒体
用磁性素材としての強磁性金属粉微粒子及びその製造方
法に関するものである。
DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to ferromagnetic metal powder particles as a magnetic material for high-density magnetic recording media mainly used for audio and video, and a method for producing the same.

〈従来技術〉 磁気テープ、磁気記録媒体として有用な磁性粉末は、γ
−酸化秩が主体であったが、近年vT訓や高級オーディ
オ用の高密度記録媒体が望まれるようになり、オキシ水
酸化鉄あるいは酸化鉄を主体とする粉末を還元性ガスに
よる気相接触還元反応によって得られる金属鉄もしくは
コバルト或いはニッケルと鉄との合金を主体とする高い
保磁力を有する磁性粉末が用いられる様になってきた。
<Prior art> Magnetic powders useful as magnetic tapes and magnetic recording media are
- Oxide was mainly used, but in recent years there has been a demand for high-density recording media for vT-kun and high-end audio, and gas-phase catalytic reduction of iron oxyhydroxide or iron oxide-based powder using reducing gas Magnetic powders having a high coercive force and mainly composed of metallic iron or cobalt obtained by reaction, or an alloy of nickel and iron have come to be used.

金属磁性微粒子の保磁力は形状異方性が強い為、粒子サ
イズ、針状性等に依存するが、テープ記録用としては再
生ヘッド、消去ヘッドの能力との兼合いで適性な保磁力
が必要である。
The coercive force of metal magnetic fine particles has strong shape anisotropy, so it depends on particle size, acicularity, etc., but for tape recording, an appropriate coercive force is required in consideration of the capabilities of the playback head and erase head. It is.

磁気記録用媒体はオーディオ用、ビデオ用を問わず広い
記録周波数帯域での高出力化、低ノイズ・化、即ち磁性
粉末としてはその形状は微細化の傾向にあり、尚且塗料
用樹脂との1和性や分散性、塗膜の配向性・充填性を更
に向上する事が望まれ、バインダー樹脂・各種添加剤の
改良及び塗料分散・媒体加工技術の改良研究さが成され
ている(:例えば明石丘部「磁気テープの進歩」、日本
応用磁気学会誌、7(3)、185(1983)、)。
Magnetic recording media, whether used for audio or video, have a tendency to achieve higher output and lower noise in a wide recording frequency band. It is desired to further improve the compatibility, dispersibility, orientation and filling properties of coating films, and research is being carried out to improve binder resins and various additives, as well as paint dispersion and media processing technology (e.g. Okabe Akashi, "Advances in magnetic tape," Journal of the Japan Society of Applied Magnetics, 7(3), 185 (1983),).

−役に、粒子が微細化すると表面エネルギーが大きくな
り、その為に二次凝集性が強くなる。即ち、磁性粉末の
場合、素材の一次粒子の微細化により、塗料分散は必然
的に難しくなる。
-As the particles become finer, their surface energy increases, which leads to stronger secondary agglomeration. That is, in the case of magnetic powder, the finer primary particles of the material inevitably make it difficult to disperse the paint.

磁性素材としての金属微粒子は飽和磁化(δS)が大き
いことなどから凝集し易く、又表面変性オキシ水酸化鉄
の気相還元で製造すると、粒子間の焼結が生成する事も
あり、分散操作も困難になる。
Fine metal particles as a magnetic material tend to aggregate due to their large saturation magnetization (δS), and when they are produced by gas-phase reduction of surface-modified iron oxyhydroxide, sintering between particles may occur, so dispersion operation is difficult. It also becomes difficult.

従って、磁性金属微粒子の二次凝集塊を少なくする事、
バインダー樹脂との親和性の改善等の目的で分散操作の
前に個々の粒子にバラバラにほぐす、−次粒子化の技術
が重要になってきた。
Therefore, reducing the secondary agglomerates of magnetic metal fine particles,
In order to improve the affinity with the binder resin, the technique of breaking up particles into individual particles before dispersion has become important.

磁性粉をカップリング剤による表面処理・表面活性剤の
吸着・有機モノマーの重合樹脂処理・マイクロカプセル
化処理等の化学的処理、所謂表面改質がホモミキサー・
ディスパー等による機械的分散処理と併用する系で成さ
れている(例えば、小石真綿、角田光雄「粉体の表面化
学」日刊工業新聞社)。
Chemical treatments such as surface treatment of magnetic powder with a coupling agent, adsorption of surface active agents, polymerization resin treatment of organic monomers, and microencapsulation treatment, so-called surface modification, are performed using homomixers.
This is done in a system that is used in combination with mechanical dispersion treatment using a disper or the like (for example, Mawata Koishi and Mitsuo Tsunoda, "Surface Chemistry of Powder", Nikkan Kogyo Shimbun).

表面変性オキシ水酸化鉄の還元で製造した磁性金属微粒
子はその本質として、形蟲粒子は多孔性となる為、γ−
Fe2es等の酸化鉄系の磁性粉に比べて、機械的強度
がきわめて弱い。従って、各種の表面改質操作、特に凝
集塊を一次粒子化する微粒化処理は細心の注意をはらっ
て行うのが普通である。
Magnetic metal fine particles produced by reduction of surface-modified iron oxyhydroxide are inherently porous, so γ-
The mechanical strength is extremely weak compared to iron oxide magnetic powder such as Fe2es. Therefore, various surface modification operations, especially atomization treatment for converting aggregates into primary particles, are usually performed with extreme caution.

く本発明の解決しようとする問題点〉 音声及び映像を主対象とした高密度磁気記録媒体用の磁
性素材としての針状性磁性金属粉はγ−Fe11Ost
c イはコバルト含有γ−Fe20gに比して、凝集性
・焼結性が大きく、表面改質に於いて併用する微粒化処
理により粒子崩壊が起り易い為、その針状性の形状を保
持されない場合がある。
Problems to be Solved by the Present Invention> Acicular magnetic metal powder as a magnetic material for high-density magnetic recording media mainly intended for audio and video is γ-Fe11Ost.
C A has greater cohesiveness and sinterability than 20g of cobalt-containing γ-Fe, and its acicular shape cannot be maintained because particles tend to collapse due to the atomization treatment used in conjunction with surface modification. There are cases.

二次凝集塊を少な(する為の微粒化の機種の選定、使用
条件等が難しく、磁性粉の磁気特性、特に保磁力の低下
や媒体加工した場合の角型比(Br/8m)の低下等、
必ずしも本来の目的である微粒化処理が達成されていな
いのが現状である。
It is difficult to select an atomization model and use conditions to reduce the number of secondary agglomerates, and the magnetic properties of magnetic powder, especially a decrease in coercive force and a decrease in squareness ratio (Br/8m) when processed with media, are difficult. etc,
At present, the original purpose of atomization processing is not necessarily achieved.

本発明の目的は以上の問題を考慮して、超微細な磁性金
属微粒子に於いて二次凝集塊の極めて少ない、容易に高
分散性磁性塗料の調製可能な磁性金属微粒子の製造方法
を提供しようとするものである。
SUMMARY OF THE INVENTION In view of the above-mentioned problems, the object of the present invention is to provide a method for producing magnetic metal fine particles that can easily produce a highly dispersible magnetic paint with extremely few secondary agglomerates in ultrafine magnetic metal fine particles. That is.

く問題点を解決する為の手段〉 本発明者等は、上記の問題点の解決を計る為に、禮々の
検肘乞加えた結果、よ(知られた湿式法による微細な針
状性オキシ水酸化鉄微粒子を合成し、次いで形状保持成
分類による被着変性処理を施し、以後必要に応じて洗浄
・乾燥した後、ふるい粒度100mesh ’1通過す
る迄に粉砕し、水素ガスを主体とする還元性ガスにより
気相接触還元反応に供した粉体が、その形状は粗原料と
したオキシ水酸化鉄微粒子のそれを破損・破壊する事な
(良(継承した針状性を示し得る事、且二次凝集塊・粒
子間焼結の極めて少なく、高分散性磁性塗料調製が容易
である事を見い出し、本発明に到達した。
Means for Solving the Problems> In order to solve the above problems, the inventors of the present invention have conducted extensive research and have discovered that fine needle-like Iron oxyhydroxide fine particles are synthesized, then subjected to adhesion modification treatment using a shape-retaining component, washed and dried as necessary, and then crushed until they pass through a sieve with a particle size of 100 mesh '1. The shape of the powder subjected to a gas phase catalytic reduction reaction with a reducing gas is such that it does not damage or destroy that of the iron oxyhydroxide fine particles used as the crude raw material. , and found that secondary agglomerates and interparticle sintering are extremely small, making it easy to prepare a highly dispersible magnetic paint, and have arrived at the present invention.

以下本発明について更に詳しく述べると、比表面積20
〜150♂/gr−のα−オキシ水酸化鉄もしくはAI
−、Ti、 Cr、 Mn、 Co、 Ni、 Zn等
の元素から選ばれた少なくとも一種の元素が共沈したα
−オキシ水酸化鉄に焼結回避・形状保持・保磁力制御・
耐蝕性の向上等の為に、B、 At、 Si、 P、 
Ti、 Zn、Cr、Mn、Co、 Ni、 Cu、 
Zr、 Sn、 Pb、 Ca、 Ba等の元素から選
ばれた少なくとも一種の元素を表面被着し、乾燥した表
面変性α−オキシ水酸化鉄を粉砕し、ふるい粒度100
mesh 、好ましくはふるい粒度200meshを通
過する粉体を調製し、必要に応じて300〜800℃に
おいて仮焼し表面変性α−酸化鉄とした後、水素ガスを
主体とする還元性ガスにより、300〜500℃で気相
接触還元反応に供して製造された鉄を主体とした金属磁
性微粒子である。
To describe the present invention in more detail below, specific surface area 20
~150♂/gr- α-iron oxyhydroxide or AI
α in which at least one element selected from elements such as -, Ti, Cr, Mn, Co, Ni, and Zn is co-precipitated.
- Iron oxyhydroxide to avoid sintering, maintain shape, control coercive force,
To improve corrosion resistance, etc., B, At, Si, P,
Ti, Zn, Cr, Mn, Co, Ni, Cu,
At least one element selected from elements such as Zr, Sn, Pb, Ca, Ba, etc. is adhered to the surface, and the dried surface-modified α-iron oxyhydroxide is ground and sieved to a particle size of 100.
A powder that passes through a mesh, preferably a sieve particle size of 200 mesh is prepared, and if necessary, calcined at 300 to 800°C to form a surface-modified α-iron oxide. These are metal magnetic fine particles mainly made of iron produced by subjecting them to a gas phase catalytic reduction reaction at ~500°C.

表面変性し、必要に応じて洗浄した後、100〜180
℃で乾燥したオキシ水酸化鉄粉体の粉砕には市販の衝撃
式粉砕機、例えば不二パウダル■裂ニックサンプルミル
或いは■奈良製作所製自由粉砕機等が使用可能である。
After surface modification and cleaning as necessary, 100-180
For pulverizing the iron oxyhydroxide powder dried at .degree. C., a commercially available impact pulverizer, such as Fuji Powder's cracked nick sample mill or Nara Seisakusho's free pulverizer, can be used.

即ち後者の場合、回転数1000〜3000 rpm、
 、供給量5 C1〜500Ky/ hr、に於いて粉
砕ミルの下部或いは側面出口に0.1〜3.0.5zl
の穴径のスクリーン暑装着して1回或いは2回以上粉砕
丁ればioo〜200mesh以下の乾燥粉体が待る事
ができる。必ずしも、装着するスクリーンメツシュの穴
径は極端に小さくする必要はな(、既述の穴径で充分に
その効果を発現するものである。むしろ、極端な微粉砕
は装置の粉砕締力の低下、粉体の一次粒子であるオキシ
水酸化鉄の針状性の形状を破壊する事もあり、好ましく
ない。
That is, in the latter case, the rotation speed is 1000 to 3000 rpm,
, 0.1 to 3.0.5 zl to the bottom or side outlet of the grinding mill at a feed rate of 5 C1 to 500 Ky/hr.
If you attach a screen with a hole diameter of 200 mm and crush it once or twice, you can expect a dry powder of less than 200 mesh. It is not necessarily necessary to make the hole diameter of the attached screen mesh extremely small (the hole diameter mentioned above is sufficient to achieve the effect. Rather, extreme fine pulverization is due to the crushing force of the device. This is not preferable because it may cause the acicular shape of iron oxyhydroxide, which is the primary particle of the powder, to deteriorate.

該粉砕粉を必要に応じて300〜800℃において仮焼
し表面変性α−Fezesとした後、還元炉に充填し、
水素ガスを主体とする還元性ガスにより、300〜50
0℃で気相接触還元して得られた金属磁性微粒子の粒度
は該粉砕粉の粒度と同様もしくはそれ以上に微細化され
たものとなる。
The pulverized powder is calcined at 300 to 800°C as necessary to form surface-modified α-Fezes, and then charged into a reduction furnace.
300 to 50 by reducing gas mainly composed of hydrogen gas
The particle size of the metal magnetic fine particles obtained by vapor phase catalytic reduction at 0° C. is similar to or even finer than the particle size of the pulverized powder.

該金属磁性微粒子は極めて微細な粒子から構成されてい
るので、そのままでは大気中で自然発火し酸化鉄に戻っ
てしまう事から、通常の方法により酸化被膜を形成し、
安定化する。
Since the metal magnetic fine particles are composed of extremely fine particles, they will spontaneously ignite in the atmosphere and return to iron oxide, so an oxide film is formed using a normal method.
Stabilize.

該金属微粒子を各種有機溶剤に浸漬したスラリーはギア
ーポンプ・バイキングポンプ等で容易釦送液する事が可
能であり、送液において磁性金属粉の針状性の形状を破
壊する事もない。
The slurry obtained by soaking the metal fine particles in various organic solvents can be easily pumped using a gear pump, Viking pump, etc., and the acicular shape of the magnetic metal powder is not destroyed during the feeding.

該金属磁性微粒子の塗料haにおいては二次凝集塊が小
さい為、バインダー樹脂との親和性・分散性の助剤とし
て加えられる各種添加剤ともすみやかに、尚且均−に吸
着が進行し、容易に磁性塗料とする事が出来、その結果
としてテープ媒体の配向性・充填性の向上が著しい。
Since the secondary agglomerates in the paint ha of the metal magnetic fine particles are small, adsorption of various additives added as auxiliary agents for affinity and dispersibility with the binder resin progresses quickly and evenly, making it easy to absorb. It can be used as a magnetic coating material, and as a result, the orientation and filling properties of tape media are significantly improved.

更に本発明の効果は、均一な仮焼・還元を行う目的で粉
体を流動する場合に顕著である。即ち、回転式或いは攪
拌式加熱炉により強制的に粉体を流動混合し、仮焼成い
は気相接触還元反応を行う場合、本発明で規定する微粉
砕に比較して荒(粉砕された粉体は固く数置な砂粒状の
所謂造粒された粉体になり、製造された磁性金属微粒子
の有機溶剤スラリーの流動性は極めて悪(、塗料調製の
前処理としての微粒化処理が必須条件となり、工程も複
雑になり、好ましくない。しかるに本発明の如<100
mesh以下迄に微粉砕された粉体は、造粒されること
もなく、製造された磁性金属微粒子の有機溶剤スラリー
の流動性は良好となり、塗料分散性も極めて容易になる
Further, the effects of the present invention are remarkable when the powder is fluidized for the purpose of uniform calcination and reduction. That is, when powder is forcibly fluidized and mixed in a rotary or stirring heating furnace and calcined or gas phase catalytic reduction reaction is performed, the powder is rough (pulverized powder) compared to the fine pulverization specified in the present invention. The body becomes a so-called granulated powder with a hard, sand-like shape, and the fluidity of the organic solvent slurry of the manufactured magnetic metal fine particles is extremely poor (atomization treatment as a pretreatment for paint preparation is an essential condition). Therefore, the process becomes complicated, which is undesirable.However, as in the present invention, <100
Powder that has been pulverized to a size smaller than a mesh is not granulated, and the organic solvent slurry of the produced magnetic metal particles has good fluidity, and paint dispersibility is extremely easy.

く作 月〉 本発明の強磁性金属微粒子の特徴は一次粒子サイズと対
比して、従来より凝集塊が少ない事であり、該有機溶剤
スラリーの流動性が良好であり、塗料分散性が曵好な事
である。
Tsuki Kusaku〉 The characteristics of the ferromagnetic metal fine particles of the present invention are that compared to the primary particle size, there are fewer agglomerates than conventional ones, and the organic solvent slurry has good fluidity, which improves paint dispersibility. That's what it is.

特に、原料である表面変性オキシ水酸化鉄の乾燥粉体を
回転式或いは攪拌式加熱炉により強制的に粉体を流動混
合し仮焼成いは気相接触還元反応を行う場合、造粒され
ることもなく、製造された磁性金属微粒子の有機溶剤ス
ラリーの流動性・塗料分散性も良好となり、極めて好ま
しい。
In particular, when dry powder of surface-modified iron oxyhydroxide, which is a raw material, is forcibly fluidized and mixed in a rotary or stirring heating furnace and calcined or subjected to a gas phase catalytic reduction reaction, granulation occurs. Without this, the fluidity and paint dispersibility of the produced organic solvent slurry of magnetic metal fine particles are also improved, which is extremely preferable.

又、近年の磁性微粒子の微細化傾向にある中で、長軸径
:0.5μ以下の針状性金属微粒子系の使抛二必要とな
る8 m / mビデオ用途等に於いて本発明の強磁性
金属微粒子製造方法は極めて有用な手段となり得る。
In addition, with the recent trend toward miniaturization of magnetic fine particles, the present invention is suitable for applications such as 8 m / m video applications, which require the use of acicular metal fine particles with a major axis diameter of 0.5 μ or less. A method for producing ferromagnetic metal fine particles can be an extremely useful means.

この結果、媒体加工を施した場合、より微細化を計った
微粒子系を素材粉として使用可能になり、磁気特性上は
殆んど変わる事のないシステムにする事が可能となる。
As a result, when media processing is performed, finer particles can be used as the raw material powder, making it possible to create a system with almost no change in magnetic properties.

この事の直接的結果として、磁性粉の粒子サイズに強く
支配される磁気記8%性、即ち高周波数域での電磁変換
特性(:感度・出力)およびノイズが極めて大きく改善
される事となる。
As a direct result of this, the magnetic properties, which are strongly controlled by the particle size of the magnetic powder, that is, the electromagnetic conversion characteristics (sensitivity/output) and noise in the high frequency range, will be greatly improved. .

〈実施例〉 以下、実施例及び比較例により、本発明の方法及び効果
を詳細に述べる。
<Example> Hereinafter, the method and effects of the present invention will be described in detail with reference to Examples and Comparative Examples.

実施例−1 本実施例は、8 m 7mビデオ用途の、金属鉄を主要
成分とした強磁性金属鉄微粒子についての本発明の方法
及びその効果の大要を示す例である。
Example 1 This example is an example showing an overview of the method of the present invention and its effects regarding ferromagnetic metal iron fine particles containing metal iron as a main component for use in 8m x 7m video.

〔原料粉の製造〕[Manufacture of raw material powder]

特開昭57−106527及び57−96504記載の
方法により、P、及びSi成分を重量比でP/Fe=0
.3/100及びSi /Fe = 1.5/ 100
だけ含む針状性オキシ水酸化鉄微粒子を合成した。
By the method described in JP-A No. 57-106527 and No. 57-96504, the weight ratio of P and Si components is P/Fe=0.
.. 3/100 and Si/Fe = 1.5/100
We synthesized acicular iron oxyhydroxide microparticles containing iron oxyhydroxide.

該微粒子の形状は、窒素ガスの吸着特性から算出した比
表面積(:SA)は95.Or//gr、又6乃至9万
倍の透過電子顕微鏡像から算出した長軸径(:L)と短
軸径(:D)との比、即ち軸比(:L/D)は15であ
った。
The shape of the fine particles has a specific surface area (SA) of 95. Or//gr, and the ratio of the major axis diameter (:L) to the minor axis diameter (:D), that is, the axial ratio (:L/D), calculated from a transmission electron microscope image at 60,000 to 90,000 times, is 15. there were.

次いで、特開昭58−48612記載の方法によりホウ
酸亜鉛の被着変性処理を加え(B/Fe=0.6/10
0重量比)、120℃で一夜乾燥した。
Next, adhesion modification treatment with zinc borate was added by the method described in JP-A-58-48612 (B/Fe=0.6/10
0 weight ratio) and dried at 120°C overnight.

〔乾燥粉の粉砕及び粒度分布測定〕[Crushing of dry powder and measurement of particle size distribution]

該乾燥粉を不二パクダル■製ニックサンプルミルでスク
リーン・メッシ:L1m、1’l用いて1回粉砕した。
The dry powder was pulverized once using a nick sample mill manufactured by Fuji Pakudal ■ using a screen mesh: L1m, 1'l.

該粉砕粉の粒度分布測定は以下の様にして行った。即ち
、粉体10 gr、を粒度100mesh及び200m
eshのふるい(75w5l )を用いて、振と5機に
5−0かける事により分級操作を行った。次いで、分級
された粉体の重量測定を行い、各粒度分布を重量パーセ
ントで表示しく以下、粒度分布測定はこの方法で行う)
その結果を表に示す。
The particle size distribution of the pulverized powder was measured as follows. That is, powder 10 gr, particle size 100 mesh and 200 m
Using an esh sieve (75w5l), a classification operation was performed by shaking and multiplying by 5-0. Next, the weight of the classified powder is measured, and each particle size distribution is expressed as a weight percentage (hereinafter, particle size distribution measurements will be performed using this method).
The results are shown in the table.

〔還元鉄粉の製造〕[Manufacture of reduced iron powder]

該粉体を固定床方式の還元炉に充填し、水素ガスによる
気相接触還元反応(:温度=375℃、ガス空間速度=
 20 Nni’ −H2/ kgr −Fe、 Hr
、 )により還元鉄粉とした。
The powder was charged into a fixed-bed reduction furnace, and a gas phase catalytic reduction reaction using hydrogen gas (temperature = 375°C, gas hourly space velocity =
20 Nni'-H2/kgr-Fe, Hr
) to obtain reduced iron powder.

次いで、該微粒子を充分トルエンに浸漬して後、該微粒
子スラリーをホーロー梨バット上に1tMt程の厚味に
なる様に移し、大気中でトルエンの飛散処理を加えた。
Next, after thoroughly immersing the fine particles in toluene, the fine particle slurry was transferred onto an enamel pear vat to a thickness of about 1 tMt, and subjected to toluene scattering treatment in the atmosphere.

溶剤臭が無くなった段階で磁性粉を回収し、風乾金属鉄
粉とした。
When the smell of the solvent disappeared, the magnetic powder was collected and made into air-dried metal iron powder.

該風乾金属鉄粉の粒度分布及び東英工業社製振動式磁気
特性測定装置:VSM−III型による磁性の評価の結
果を表に示す。
The particle size distribution of the air-dried metallic iron powder and the results of magnetic evaluation using a vibrating magnetic property measuring device (Model VSM-III manufactured by Toei Kogyo Co., Ltd.) are shown in the table.

〔風乾金属鉄粉の塗料化、塗工及びテープ特性の評価〕[Evaluation of air-dried metal iron powder into paint, coating and tape properties]

該風乾金属鉄粉10 gr、を採取して、下記材料とぐ 共に、内容積550−ポットに投入し、米国レット・デ
ビル社製ペイント・シェーカーで5時間混合・分散を続
けた。分散メディアとしては、211x grのα−ア
ルミナ・ビーズを用いた。
10 grams of the air-dried metal iron powder was collected and put into a 550-pot pot along with the following materials, and mixed and dispersed for 5 hours using a paint shaker manufactured by Rhett Deville, USA. 211x gr α-alumina beads were used as the dispersion media.

−UCC社袈塩酢ピ系ポリマー  VAGH: 0.8
 gr・三井東圧化学社表ポリウレタンNL−2448
:1.2gr ・大人化学社製リン酸エステル AP−13: 0.5
r ・住人化学社製α−アルミナ AKP−50: 0.5
r ・溶剤 )ルエy:15gr、、MEK:15gr。
-UCC Co., Ltd. Salt and Vinegar Polymer VAGH: 0.8
gr・Mitsui Toatsu Chemical Co., Ltd. table polyurethane NL-2448
: 1.2gr ・Phosphate ester AP-13 manufactured by Otona Kagaku Co., Ltd.: 0.5
r ・α-Alumina AKP-50 manufactured by Sumima Kagaku Co., Ltd.: 0.5
r・Solvent) Luey: 15gr, MEK: 15gr.

次いで、分散メディアを分離して磁性塗料とし、磁気テ
ープ仕様の精密コーターにてアプリケーターを利用して
13μ厚のトーレ社製ポリエステル・フィルム(ニルミ
ラー13W−QO6S)上に塗工した。その後、カレン
ダー・ロール処理して塗膜面の平滑化処理を加え、50
℃にて2日間熱処理を加えてポリウレタン硬化反応を完
結させた。該シートを8.00mに裁断して、8 m 
7mビデオ・カセット仕様サイズの磁気テープを製造し
た。
Next, the dispersion media was separated to obtain a magnetic paint, which was coated onto a 13 μm thick polyester film (Nilmirror 13W-QO6S) manufactured by Toray Industries using an applicator in a precision coater equipped with magnetic tape. After that, the coating surface was smoothed by calender roll treatment, and
The polyurethane curing reaction was completed by heat treatment at ℃ for 2 days. The sheet was cut to 8.00 m, and 8 m
A magnetic tape with the size specified for a 7m video cassette was manufactured.

該磁気テープの磁気特性を、既述の測定装置にて測定し
た結果を表に示す。
The results of measuring the magnetic properties of the magnetic tape using the above-mentioned measuring device are shown in the table.

実施例−2 攪拌式(1rpm)還元炉を用い、粉体を流動させなが
ら還元した事以外は、原料粉の製造、乾燥粉の粉砕及び
粒度分布測定、還元鉄粉の辺造及び風乾金属鉄粉の塗料
化、塗工及びテープ特性の評価は実施例−1と同様の方
法で行い、金属鉄微粒子を得た。その結果を表に示す。
Example-2 Except for reducing the powder while fluidizing it using a stirring type (1 rpm) reduction furnace, the following steps were taken: production of raw material powder, pulverization of dry powder, measurement of particle size distribution, production of reduced iron powder, and air-drying of metallic iron. The powder was made into a paint, applied, and the tape properties were evaluated in the same manner as in Example 1 to obtain metallic iron fine particles. The results are shown in the table.

比較例−1 乾燥粉を乳バチを用いて粉砕し、16meshのふるい
を通過した粉体を使用した事以外は、原料粉の製造、粒
度分布測定、還元鉄粉の製造及び風乾金属鉄粉の塗料化
、塗工及びテープ特性の評価は実施例−1と同様の方法
で行い、金属鉄微粒子を得た。その結果乞表に示す。
Comparative Example-1 The production of raw material powder, particle size distribution measurement, production of reduced iron powder, and air-dried metal iron powder were carried out except that dry powder was crushed using a milk wasp and the powder passed through a 16 mesh sieve was used. The coating, coating, and evaluation of tape properties were carried out in the same manner as in Example-1, and metallic iron fine particles were obtained. The results are shown in the table below.

実施例−3 比表面積90.1♂/grのα−オキシ水酸化鉄微粒子
を使用した事以外は、原料粉の製造、乾燥粉の粉砕及び
粒度分布測定、還元鉄粉の製造及び風乾金属鉄粉の塗料
化、塗工及びテープ特性の評価は実施例−1と同様の方
法で行い、金属鉄微粒子を得た。その結果を表に示す。
Example-3 Except for using α-iron oxyhydroxide fine particles with a specific surface area of 90.1♂/gr, the following steps were taken: production of raw material powder, pulverization of dry powder, measurement of particle size distribution, production of reduced iron powder, and air-drying of metallic iron. The powder was made into a paint, applied, and the tape properties were evaluated in the same manner as in Example 1 to obtain metallic iron fine particles. The results are shown in the table.

実施例−4 比表面積90.1 m”/ grのα−オキシ水酸化鉄
微粒子乞使甲した事及び粉砕に於いて■奈良製作所製自
由粉砕機(型式M−4,200Orpm、、スクリーン
・メツシュ2m32F)を用いて3回粉砕した事以外は
、原料粉の製造、及び粒度分布測定、還元鉄粉の製造及
び風乾金属鉄粉の塗料化、塗工及びテープ特性の評価は
実施例−2と同様の方法で行い、金属鉄微粒子を得た。
Example 4 α-iron oxyhydroxide fine particles with a specific surface area of 90.1 m”/gr The production of raw material powder, particle size distribution measurement, production of reduced iron powder, making air-dried metal iron powder into paint, coating, and evaluation of tape properties were the same as in Example-2, except that it was crushed three times using 2m32F). The same method was used to obtain metallic iron fine particles.

その結果を表に示す。The results are shown in the table.

比較例−2 粉砕に於いて■奈良製作所製自由粉砕機(型式%式%) を用いて1回粉砕した事以外は、原料粉の製造、及び粒
度分布測定、還元鉄粉の製造及び風乾金属鉄粉の塗料化
、塗工及びテープ特性の評価は実施例−4と同様の方法
で行い、金属鉄微粒子を得た。
Comparative Example-2 In the pulverization process, the manufacturing of raw material powder, measurement of particle size distribution, manufacturing of reduced iron powder, and air-drying of metal, except that the material was pulverized once using a free crusher manufactured by Nara Seisakusho (model % formula %). The coating of the iron powder, the coating, and the evaluation of the tape properties were carried out in the same manner as in Example 4, and metallic iron fine particles were obtained.

その結果を表に示す。The results are shown in the table.

比較例−5 比表面積74.2r+?/grのα−オキシ水酸化鉄微
粒子を使用した事以外は、原料粉の製造、及び粒度分布
測定、還元鉄粉の製造及び風乾金属鉄粉の塗料化、塗工
及びテープ特性の評価は比較例−2と同様の方法で行い
、金属鉄微粒子を得た。その結果を表に示す。
Comparative Example-5 Specific surface area 74.2r+? Except for the use of α-iron oxyhydroxide fine particles of /gr, the production of raw material powder, particle size distribution measurement, production of reduced iron powder, making paint from air-dried metallic iron powder, coating, and evaluation of tape properties were compared. Metallic iron fine particles were obtained in the same manner as in Example-2. The results are shown in the table.

く効 果〉 実施例及び比較例の結果から本発明の作用・効果をまと
めると以下の通りとなる。
Effects> The effects and effects of the present invention can be summarized as follows from the results of Examples and Comparative Examples.

即ち、高密度磁気記録に適した磁気記録素材としての針
状性強磁性金属鉄粉微粒子において、被着変性された針
状性オキシ水酸化鉄微粒子を衝撃式粉砕機等で微粉砕し
た後、還元性ガスによる気相接触還元反応によって強磁
性還元鉄微粒子とする事によって、 (1)金属鉄微粒子自体に関しては、原料であるオキシ
水酸化鉄の形状を良(継承した針状性を示しつつ、 (2)二次凝集塊の粒度が極めて微細になり、該金属鉄
微粒子の有機溶剤スラリーの流動性が大きく改良された
事、 (3)塗料分散操作が容易になり、媒体加工すると磁気
特性、特に残留磁化(Br)及び角型比(Br/8m)
が向上する娯、 が判明した。
That is, in acicular ferromagnetic metal iron powder fine particles as a magnetic recording material suitable for high-density magnetic recording, after finely pulverizing acicular iron oxyhydroxide fine particles that have been adhered and modified using an impact crusher or the like, By producing ferromagnetic reduced iron fine particles through a gas-phase catalytic reduction reaction using a reducing gas, (1) As for the metallic iron fine particles themselves, the shape of the raw material iron oxyhydroxide can be improved (while still exhibiting the inherited acicularity). , (2) The particle size of the secondary agglomerates has become extremely fine, and the fluidity of the organic solvent slurry of the metal iron particles has been greatly improved. , especially residual magnetization (Br) and squareness ratio (Br/8m)
It has been found that entertainment improves.

以上の様に、本発明は従前の製造工程・設備の殆んど大
部分を変更する事なく、品質改良の著しい強磁性金属鉄
微粒子のス造方法を提供するものである。
As described above, the present invention provides a method for manufacturing fine ferromagnetic metal iron particles that significantly improves quality without changing most of the conventional manufacturing processes and equipment.

Claims (2)

【特許請求の範囲】[Claims] (1)表面変性オキシ水酸化鉄あるいは酸化鉄を還元性
ガスによる気相接触還元反応によって磁気記録媒体用磁
性素材に好適な強磁性鉄微粒子を製造する方法において
該得られる強磁性鉄微粒子の二次凝集体が90%以上1
00meshのふるい粒度を通過する粒子となっている
事を特徴とする針状性の強磁性鉄微粒子の製造方法。
(1) In a method for producing ferromagnetic iron fine particles suitable for magnetic materials for magnetic recording media by a gas phase catalytic reduction reaction of surface-modified iron oxyhydroxide or iron oxide with a reducing gas, two of the obtained ferromagnetic iron fine particles are obtained. 90% or more of secondary aggregates1
A method for producing acicular ferromagnetic iron fine particles, characterized in that the particles pass through a 00 mesh sieve particle size.
(2)表面変性オキシ水酸化鉄あるいは酸化鉄を二次凝
集体が90%以上100meshのふるい粒度を通過す
るまで粉砕した後、還元性ガスによる気相接触還元反応
によって強磁性鉄微粒子にする特許請求の範囲第1項記
載の方法。
(2) A patent that grinds surface-modified iron oxyhydroxide or iron oxide until more than 90% of the secondary aggregates pass through a 100-mesh sieve, and then transforms the surface into ferromagnetic iron fine particles through a gas-phase catalytic reduction reaction using a reducing gas. The method according to claim 1.
JP59273709A 1984-12-27 1984-12-27 Manufacture of needle iron fine particle for magnetic recording Pending JPS61154013A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP59273709A JPS61154013A (en) 1984-12-27 1984-12-27 Manufacture of needle iron fine particle for magnetic recording

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP59273709A JPS61154013A (en) 1984-12-27 1984-12-27 Manufacture of needle iron fine particle for magnetic recording

Publications (1)

Publication Number Publication Date
JPS61154013A true JPS61154013A (en) 1986-07-12

Family

ID=17531462

Family Applications (1)

Application Number Title Priority Date Filing Date
JP59273709A Pending JPS61154013A (en) 1984-12-27 1984-12-27 Manufacture of needle iron fine particle for magnetic recording

Country Status (1)

Country Link
JP (1) JPS61154013A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH03136214A (en) * 1989-07-28 1991-06-11 Tdk Corp Magnetic recording medium
EP0436041A1 (en) * 1989-07-21 1991-07-10 TDK Corporation Magnetic recording medium

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5022297A (en) * 1973-07-02 1975-03-10
JPS56169707A (en) * 1980-05-30 1981-12-26 Hitachi Maxell Ltd Manufacture of magnetic metal powder
JPS5944809A (en) * 1982-07-31 1984-03-13 バスフ アクチエンゲゼルシヤフト Method of producing substantially acicular ferromagnetic metal particles

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5022297A (en) * 1973-07-02 1975-03-10
JPS56169707A (en) * 1980-05-30 1981-12-26 Hitachi Maxell Ltd Manufacture of magnetic metal powder
JPS5944809A (en) * 1982-07-31 1984-03-13 バスフ アクチエンゲゼルシヤフト Method of producing substantially acicular ferromagnetic metal particles

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0436041A1 (en) * 1989-07-21 1991-07-10 TDK Corporation Magnetic recording medium
JPH03136214A (en) * 1989-07-28 1991-06-11 Tdk Corp Magnetic recording medium

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