JPH0581971B2 - - Google Patents
Info
- Publication number
- JPH0581971B2 JPH0581971B2 JP61295370A JP29537086A JPH0581971B2 JP H0581971 B2 JPH0581971 B2 JP H0581971B2 JP 61295370 A JP61295370 A JP 61295370A JP 29537086 A JP29537086 A JP 29537086A JP H0581971 B2 JPH0581971 B2 JP H0581971B2
- Authority
- JP
- Japan
- Prior art keywords
- powder
- ferrite
- sintered body
- hexagonal ferrite
- magnetic powder
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 229910000859 α-Fe Inorganic materials 0.000 claims description 40
- 230000005291 magnetic effect Effects 0.000 claims description 26
- 239000006247 magnetic powder Substances 0.000 claims description 19
- 239000002245 particle Substances 0.000 claims description 15
- 238000004519 manufacturing process Methods 0.000 claims description 13
- 239000000843 powder Substances 0.000 claims description 12
- 239000002253 acid Substances 0.000 claims description 9
- 230000005290 antiferromagnetic effect Effects 0.000 claims description 8
- 238000007496 glass forming Methods 0.000 claims description 8
- 239000000203 mixture Substances 0.000 claims description 8
- 238000010438 heat treatment Methods 0.000 claims description 7
- 229910052751 metal Inorganic materials 0.000 claims description 7
- 239000002184 metal Substances 0.000 claims description 7
- 239000013078 crystal Substances 0.000 claims description 6
- 229910001111 Fine metal Inorganic materials 0.000 claims description 4
- 238000001816 cooling Methods 0.000 claims description 2
- 238000002844 melting Methods 0.000 claims description 2
- 230000008018 melting Effects 0.000 claims description 2
- 239000012768 molten material Substances 0.000 claims description 2
- 238000010298 pulverizing process Methods 0.000 claims description 2
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 9
- 239000010419 fine particle Substances 0.000 description 8
- 230000000694 effects Effects 0.000 description 6
- 238000005054 agglomeration Methods 0.000 description 5
- 230000002776 aggregation Effects 0.000 description 5
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 4
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 4
- 229910052804 chromium Inorganic materials 0.000 description 4
- 239000011651 chromium Substances 0.000 description 4
- 239000011521 glass Substances 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 229910010413 TiO 2 Inorganic materials 0.000 description 3
- 238000007796 conventional method Methods 0.000 description 3
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
- 150000007513 acids Chemical class 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 230000005389 magnetism Effects 0.000 description 2
- 239000000155 melt Substances 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 229910020517 Co—Ti Inorganic materials 0.000 description 1
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- 238000010306 acid treatment Methods 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 229910052738 indium Inorganic materials 0.000 description 1
- 229910052745 lead Inorganic materials 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 238000005303 weighing Methods 0.000 description 1
Landscapes
- Hard Magnetic Materials (AREA)
- Compounds Of Iron (AREA)
- Paints Or Removers (AREA)
- Magnetic Record Carriers (AREA)
- Manufacturing Of Magnetic Record Carriers (AREA)
Description
［発明の目的］
（産業上の利用分野）
本発明は、高密度磁気記録媒体の製造に用いら
れる磁性粉末の製造方法に係り、特に分散性に優
れた六方晶系フエライトからなる磁性粉末の製造
方法に関する。
（従来の技術）
従来から、高密度磁気記録媒体を製造する方法
として、六方晶系フエライトの微粒子を用いた塗
布法が知られており、また単一の六方晶系フエラ
イトでは保磁力が大きく記録時に磁気ヘツドが飽
和して磁気記録が困難となるため、六方晶系フエ
ライトの構成原子の一部を特定の他の原子で置換
することにより、その保磁力を磁気記録に適する
値まで低減させることも知られている。
このような垂直磁気記録に用いられる六方晶系
フエライト微粒子の粒径は、0.01μｍ未満では磁
気記録に要する強い磁性を呈することができず、
0.3μｍを越えると高密度記録としての垂直磁気記
録を有利に行い難いため、0.01〜0.3μｍの範囲の
ものが適している。
上記のような条件に適合する磁性粉末を製造す
る方法としては、六方晶系フエライトの基本成
分、保磁力低減のための置換成分およびガラス形
成成分を混合して加熱溶融させ、この溶融物を急
速に冷却して非晶質体とし、これを熱処理して六
方晶系フエライト微粒子を析出させた後、これを
粉砕して、得られた微粒子をリン酸および酢酸等
の希酸で処理してガラス形成成分を溶解除去する
ことによつて六方晶系フエライトを分離抽出する
といういわゆるガラス結晶化法が採用されてい
る。
（発明が解決しようとする問題点）
しかしながら、このような従来の磁性粉末の製
造方法では、得られるフレーク状の非晶質体が熱
処理後もほとんど形成変化しないこととフエライ
ト成分の比較的大きい硬度のため、希酸処理に有
効な形成まで微粉末化することが難しく、また六
方晶系フエライトの基本成分が、ガラス形成成分
に対して40重量％を越えるような場合には、生成
したフエライト微粒子の間隔が接近しているの
で、ガラス形成成分がフエライト粒子間に挟まれ
た状態となる。これらのことから希酸の浸透によ
るガラス形成成分の溶解除去が困難となり、得ら
れるフエライト粒子の表面活性が大きく凝集性が
高くなるため、堅固な凝集塊を形成しやすく、分
散性が低下するという問題があつた。
本発明はこのような従来の事情に対処してなさ
れたもので、フエライト粒子とガラス形成成分の
分離を促進し、かつフエライト粒子の凝集を抑制
して、分散性に優れた磁性粉末を製造する方法を
提供することを目的とする。
［発明の構成］
（問題点を解決するための手段）
本発明の磁性粉末の製造方法は、
(イ) 六方晶系フエライトの基本成分、保磁力低減
のための置換成分およびガラス形成成分の混合
物を加熱溶融させる工程と、
(ロ) この溶融物を急冷して非晶質体とする工程
と、
(ハ) この非晶質体に熱処理を施して六方晶系フエ
ライトの結晶を析出させる工程と、
(ニ) 熱処理の施された焼結体を微粉砕する工程
と、
(ホ) この微粉砕された焼結体を希酸で処理して六
方晶系フエライトの結晶を抽出する工程と
からなる磁性粉末の製造方法において、
前記(ホ)の希酸で処理する工程を、前記微粉砕さ
れた焼結体に軟磁性または反強磁性の金属微粉末
を添加し、かつ高周波磁界を印加しながら行うこ
とを特徴としている。
本発明で使用する軟磁性または反強磁性の金属
微粉末としては、例えばクロム、ニツケル、マン
ガン、モリブデン等が上げられ、その粒径は0.01
〜0.5μｍの範囲が好ましく、また添加量は熱処理
後の微粉砕された焼結体に対して0.01〜0.5重量
％が好ましい。この金属微粉末の粒径が0.01μｍ
未満であると金属微粉末の表面活性が増大し、金
属粉末どうしが凝集しやすくなり、また0.5μｍを
超えると磁気媒体として使用したときのノイズの
原因となりＣ／Ｎ比が低下する。また、その添加
量が0.01重量％未満であるとその効果が十分に得
られず、0.5重量％を超えると得られるフエライ
ト結晶の磁性に悪影響をおよぼす可能性がある。
なお、本発明方法は、
一般式：AFe12-xMxO19
（式中、ＡはBa、Sr、Pbから選ばれた１種以上
の元素を、ＭはIn、Zn−Ge、Zn−Nb、Zn−Ｖ、
Co−Ti、Co−Geの１種以上の置換元素または元
素の組合わせを、またＸは０〜2.5の正の数をそ
れぞれ表す。）で示されるような置換型六方晶系
フエライトからなる磁性粉末の製造に適している
が、これに限定されるものではない。
（作用）
本発明の磁性粉末の製造方法において、熱処理
後の微粉砕した焼結体に軟磁性または反強磁性の
金属微粉末を添加して、かつ高周波磁界を印加し
ながら希酸で処理することにより、フエライト内
に磁歪効果が生じフエライト結晶とガラス相との
分離が促進されるとともに、軟磁性または反強磁
性の金属微粒子がフエライト粒子間に入り込み、
フエライト粒子の凝集を抑制して分散性を向上さ
せる。
（実施例）
次に本発明を、Fe3+イオンの一部をCo2+、
Ti4+イオンで置換した一般式
BaFe10.4Ti0.08Co0.80O19
で表される置換マグネトプランバイト型Baフエ
ライトからなる磁性粉末の製造に適用した実施例
について説明する。
実施例 １
まず、Baフエライトのフエライト成分Fe2O3
と、保磁力低減のための置換成分TiO2、CoOと、
ガラス形成成分BaO、B2O3とが重量比で、それ
ぞれFe2O331.2％、TiO22.58％、CoO2.42％、
Ba46.9％、B2O316.9％の組成比となるように、
BaCO3、Fe2O3、TiO2、CoOおよびH3BO3を所
定量秤量し、これらを混合した後、この混合物を
白金るつぼに収容し、高周波加熱ヒータを用いて
1350℃で加熱溶融した後、この溶融物を直径50
cm、回転数500r.p.m.、線圧５トンの水冷双ロー
ル上に注いで急冷し非晶質体を作成した。次い
で、この非晶質体を所定容器に充填して電気炉内
に収容し、適切な温度条件のもとで結晶化させた
後、この結晶化物をブラウン型クラツシヤーで
100メツシユ以下になるよう粉砕した。次に、得
られた結晶化物の微粉末に対して0.05重量％のク
ロム微粒子（平均粒径0.12μｍ）を添加して、80
℃の10％酢酸溶液中で103〜105Hzの高周波の交番
磁界を印加しながら処理を行い、BaO−B2O3相
やBaO相等のガラス成分を溶解除去する。なお
この際、結晶化物の量は酢酸溶液に対して20重量
％とした。次いで、この酸処理後の処理物を繰返
し水洗して、液のPHが６以上になつたところで水
洗を終了し、脱水および乾燥をおこなつてBaフ
エライト粒子を得た。
このBaフエライト粒子の凝集塊の径を測定し、
さらに常法に従つてテープ状の磁気記録媒体を作
製し、その媒体保磁力および角型比を測定した。
その結果を次表に示す。
また、本発明との比較のため、クロム微粒子の
添加と高周波磁界の印加を行わない以外は実施例
と同一条件でBaフエライトの磁性粉末を製造し、
この磁性粉末のフエライト凝集径を測定し、実施
例１と同様にテープ状の磁気記録媒体を作製し
て、その媒体保磁力および角形比を測定した。そ
の結果を次表に示す。
[Object of the Invention] (Industrial Application Field) The present invention relates to a method for producing magnetic powder used in producing high-density magnetic recording media, and in particular to a method for producing magnetic powder made of hexagonal ferrite with excellent dispersibility. Regarding the method. (Prior art) A coating method using fine particles of hexagonal ferrite has been known as a method for manufacturing high-density magnetic recording media, and a single hexagonal ferrite has a large coercive force and is difficult to record. Sometimes the magnetic head becomes saturated, making magnetic recording difficult, so by replacing some of the constituent atoms of hexagonal ferrite with specific other atoms, the coercive force can be reduced to a value suitable for magnetic recording. is also known. If the particle size of the hexagonal ferrite fine particles used in such perpendicular magnetic recording is less than 0.01 μm, it cannot exhibit the strong magnetism required for magnetic recording.
If the thickness exceeds 0.3 μm, it is difficult to advantageously perform perpendicular magnetic recording as high-density recording, so a thickness in the range of 0.01 to 0.3 μm is suitable. A method for producing magnetic powder that meets the above conditions is to mix the basic component of hexagonal ferrite, a substitute component for reducing coercive force, and a glass-forming component, heat and melt the mixture, and rapidly melt this melt. This is cooled to an amorphous state, which is heat-treated to precipitate hexagonal ferrite fine particles, which are then crushed and the resulting fine particles are treated with dilute acids such as phosphoric acid and acetic acid to form glass. A so-called glass crystallization method is employed in which hexagonal ferrite is separated and extracted by dissolving and removing the forming components. (Problems to be Solved by the Invention) However, in such a conventional method for producing magnetic powder, the resulting flake-like amorphous material hardly changes in shape even after heat treatment, and the ferrite component has a relatively high hardness. Therefore, it is difficult to micronize the hexagonal ferrite to a form that is effective for dilute acid treatment, and if the basic component of hexagonal ferrite exceeds 40% by weight based on the glass-forming components, the fine ferrite particles formed Since the distance between the ferrite particles is close, the glass-forming component is sandwiched between the ferrite particles. These factors make it difficult to dissolve and remove the glass-forming components through penetration of dilute acids, and the surface activity of the resulting ferrite particles increases, making them more cohesive, making it easier to form solid agglomerates and reducing dispersibility. There was a problem. The present invention has been made in response to such conventional circumstances, and aims to promote separation of ferrite particles and glass-forming components, suppress agglomeration of ferrite particles, and produce magnetic powder with excellent dispersibility. The purpose is to provide a method. [Structure of the Invention] (Means for Solving the Problems) The method for producing magnetic powder of the present invention includes (a) a mixture of a basic component of hexagonal ferrite, a substitution component for reducing coercive force, and a glass-forming component; (b) a step of rapidly cooling this molten material to form an amorphous body; (c) a step of subjecting this amorphous body to a heat treatment to precipitate hexagonal ferrite crystals. , (d) pulverizing the heat-treated sintered body; and (e) treating the pulverized sintered body with dilute acid to extract hexagonal ferrite crystals. In the method for producing magnetic powder, the step (e) of treating with dilute acid is performed by adding soft magnetic or antiferromagnetic metal fine powder to the finely pulverized sintered body and applying a high frequency magnetic field. It is characterized by doing. Examples of the soft magnetic or antiferromagnetic metal fine powder used in the present invention include chromium, nickel, manganese, molybdenum, etc., and the particle size thereof is 0.01.
The range of 0.5 μm is preferable, and the amount added is preferably 0.01 to 0.5% by weight based on the finely pulverized sintered body after heat treatment. The particle size of this fine metal powder is 0.01μm
If it is less than 0.5 μm, the surface activity of the metal fine powder will increase and the metal powders will tend to aggregate with each other, and if it exceeds 0.5 μm, it will cause noise when used as a magnetic medium and the C/N ratio will decrease. Further, if the amount added is less than 0.01% by weight, the effect will not be sufficiently obtained, and if it exceeds 0.5% by weight, it may adversely affect the magnetism of the ferrite crystal obtained. The method of the present invention has a general formula: AFe 12-x M x O 19 (wherein A is one or more elements selected from Ba, Sr, and Pb, and M is In, Zn-Ge, and Zn- Nb, Zn-V,
Each represents one or more substituting elements or a combination of elements such as Co-Ti and Co-Ge, and X represents a positive number from 0 to 2.5. ), but is not limited thereto. (Function) In the method for producing magnetic powder of the present invention, soft magnetic or antiferromagnetic fine metal powder is added to the finely pulverized sintered body after heat treatment, and the mixture is treated with dilute acid while applying a high frequency magnetic field. As a result, a magnetostrictive effect occurs within the ferrite, promoting the separation of the ferrite crystals and the glass phase, and soft magnetic or antiferromagnetic metal fine particles enter between the ferrite particles.
Improves dispersibility by suppressing agglomeration of ferrite particles. (Example) Next, the present invention was carried out by converting some of the Fe 3+ ions to Co 2+ ,
An example in which the present invention is applied to the production of magnetic powder consisting of substituted magnetoplumbite Ba ferrite represented by the general formula BaFe 10.4 Ti 0.08 Co 0.80 O 19 substituted with Ti 4+ ions will be described. Example 1 First, the ferrite component of Ba ferrite Fe 2 O 3
and replacement components TiO 2 and CoO to reduce coercive force,
The glass-forming components BaO and B 2 O 3 have a weight ratio of Fe 2 O 3 31.2%, TiO 2 2.58%, CoO 2.42%, respectively.
The composition ratio was 46.9% Ba and 16.9% B 2 O 3 .
After weighing a predetermined amount of BaCO 3 , Fe 2 O 3 , TiO 2 , CoO and H 3 BO 3 and mixing them, the mixture was placed in a platinum crucible and heated using a high-frequency heater.
After heating and melting at 1350°C, this melt is made into a diameter of 50mm.
The mixture was poured onto water-cooled twin rolls with a rotation speed of 500 rpm and a linear pressure of 5 tons to rapidly cool the mixture to produce an amorphous material. Next, this amorphous material is filled into a specified container, placed in an electric furnace, and crystallized under appropriate temperature conditions.
It was crushed to less than 100 mesh. Next, 0.05% by weight of chromium fine particles (average particle size 0.12 μm) was added to the obtained crystallized fine powder, and 80%
Treatment is performed in a 10% acetic acid solution at 10° C. while applying a high-frequency alternating magnetic field of 10 3 to 10 5 Hz to dissolve and remove glass components such as BaO-B 2 O 3 phase and BaO phase. At this time, the amount of crystallized material was 20% by weight based on the acetic acid solution. Next, the acid-treated product was repeatedly washed with water, and when the pH of the liquid reached 6 or more, the water washing was completed, followed by dehydration and drying to obtain Ba ferrite particles. Measure the diameter of the agglomerates of this Ba ferrite particles,
Further, a tape-shaped magnetic recording medium was prepared according to a conventional method, and its coercive force and squareness ratio were measured.
The results are shown in the table below. In addition, for comparison with the present invention, Ba ferrite magnetic powder was produced under the same conditions as in the example except that chromium fine particles were not added and no high-frequency magnetic field was applied.
The ferrite agglomeration diameter of this magnetic powder was measured, and a tape-shaped magnetic recording medium was prepared in the same manner as in Example 1, and its coercive force and squareness ratio were measured. The results are shown in the table below.
【表】
上表より明らかなように、この実施例で製造し
たBaフエライトは、従来の方法により製造した
ものに比べて、フエライト凝集径が小さくなり、
分散性が向上していることがわかり、またこれに
より、媒体保磁力が上昇し、かつ角形比も向上し
て、得られる磁気記録媒体の特性が良好となる。
実施例 ２
実施例１におけるクロム微粉末の代わりに、ニ
ツケル微粉末を0.02重量％添加する以外は実施例
１と同一条件でBaフエライトの磁性粉末を製造
した。この磁性粉末を用いて、実施例１と同様に
各特性を測定したところ、平均フエライト凝集径
0.55μｍ、媒媒体保磁力748Oe、媒体角型比0.89と
実施例１と同様な効果が得られることを確認し
た。
［発明の効果］
以上の説明からも明らかなように、本発明の磁
性粉末の製造方法によれば、熱処理後の微粉砕し
た焼結体に軟磁性または反強磁性の金属微粒子を
添加して、かつ高周波磁界を印加しながら希酸で
処理することにより、フエライトの凝集を抑制す
るして、分散性のより向上した磁性粉末を得るこ
とができる。[Table] As is clear from the above table, the Ba ferrite produced in this example has a smaller ferrite aggregate diameter than that produced by the conventional method.
It was found that the dispersibility was improved, and as a result, the medium coercive force was increased and the squareness ratio was also improved, resulting in good characteristics of the resulting magnetic recording medium. Example 2 Ba ferrite magnetic powder was produced under the same conditions as in Example 1 except that 0.02% by weight of nickel fine powder was added instead of the chromium fine powder in Example 1. Using this magnetic powder, various properties were measured in the same manner as in Example 1, and the average ferrite agglomeration diameter was
It was confirmed that the same effects as in Example 1 were obtained, with a medium coercivity of 0.55 μm, a medium coercive force of 748 Oe, and a medium squareness ratio of 0.89. [Effects of the Invention] As is clear from the above description, according to the method for producing magnetic powder of the present invention, soft magnetic or antiferromagnetic metal fine particles are added to a finely pulverized sintered body after heat treatment. By treating with dilute acid while applying a high-frequency magnetic field, agglomeration of ferrite can be suppressed and a magnetic powder with improved dispersibility can be obtained.
Claims (1)
低減のための置換成分およびガラス形成成分の
混合物を加熱溶融させる工程と、 (ロ) この溶融物を急冷して非晶質体とする工程
と、 (ハ) この非晶質体に熱処理を施して六方晶系フエ
ライトの結晶を析出させる工程と、 (ニ) 熱処理の施された焼結体を微粉砕する工程
と、 (ホ) この微粉砕された焼結体を希酸で処理して六
方晶系フエライトの結晶を抽出する工程と からなる磁性粉末の製造方法において、 前記(ホ)の希酸で処理する工程を、前記微粉砕さ
れた焼結体に軟磁性または反強磁性の金属微粉末
を添加し、かつ高周波磁界を印加しながら行うこ
とを特徴とする磁性粉末の製造方法。 ２ 軟磁性または反強磁性の金属微粉末の粒径
が、0.01〜0.5μｍの範囲である特許請求の範囲第
１項記載の磁性粉末の製造方法。 ３ 軟磁性または反強磁性の金属微粉末の添加量
が、微粉砕された焼結体に対して0.01〜0.5重量
％の範囲である特許請求の範囲第１項または第２
項記載の磁性粉末の製造方法。[Claims] 1. (a) A step of heating and melting a mixture of a basic component of hexagonal ferrite, a substitute component for reducing coercive force, and a glass-forming component, and (b) rapidly cooling the molten material to (c) a step of heat-treating this amorphous body to precipitate hexagonal ferrite crystals; (d) a step of finely pulverizing the heat-treated sintered body. , (E) A method for producing magnetic powder comprising the step of treating the finely ground sintered body with a dilute acid to extract hexagonal ferrite crystals, the step of treating with a dilute acid as described in (E) above. A method for producing magnetic powder, characterized in that adding soft magnetic or antiferromagnetic fine metal powder to the finely pulverized sintered body and applying a high frequency magnetic field. 2. The method for producing magnetic powder according to claim 1, wherein the soft magnetic or antiferromagnetic fine metal powder has a particle size in the range of 0.01 to 0.5 μm. 3. Claim 1 or 2, wherein the amount of soft magnetic or antiferromagnetic metal fine powder added is in the range of 0.01 to 0.5% by weight based on the finely pulverized sintered body.
2. Method for producing magnetic powder as described in Section 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61295370A JPS63148413A (en) | 1986-12-11 | 1986-12-11 | Production of magnetic powder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61295370A JPS63148413A (en) | 1986-12-11 | 1986-12-11 | Production of magnetic powder |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63148413A JPS63148413A (en) | 1988-06-21 |
| JPH0581971B2 true JPH0581971B2 (en) | 1993-11-17 |
Family
ID=17819748
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61295370A Granted JPS63148413A (en) | 1986-12-11 | 1986-12-11 | Production of magnetic powder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63148413A (en) |
-
1986
- 1986-12-11 JP JP61295370A patent/JPS63148413A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS63148413A (en) | 1988-06-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4493874A (en) | Production of a magnetic powder having a high dispersibility | |
| JPS6136685B2 (en) | ||
| JPH0430086B2 (en) | ||
| JPH01200605A (en) | Magnetic powder | |
| JPH0581971B2 (en) | ||
| JPS6324935B2 (en) | ||
| JP3083891B2 (en) | Magnetic powder for magnetic recording medium and method for producing the same | |
| JP2802653B2 (en) | Magnetic powder for high-density magnetic recording and method for producing the same | |
| JP2691790B2 (en) | Method for producing magnetic powder for magnetic recording medium | |
| JPH05326233A (en) | Production of magnetic powder | |
| JP2717735B2 (en) | Method for producing magnetic powder for magnetic recording medium | |
| KR960000501B1 (en) | Manufacturing method of hexagonal ferrite fine powder for high density magnetic recording | |
| JPH0359008B2 (en) | ||
| JPS63260821A (en) | Method for producing potassium titanate fiber | |
| JPS60161341A (en) | Manufacturing method of hexagonal ferrite | |
| JPS6233403A (en) | Manufacture of magnetic powder | |
| KR960000502B1 (en) | Manufacturing method of hexagonal ferrite fine powder for magnetic recording | |
| JPH0581970B2 (en) | ||
| JPH0348139B2 (en) | ||
| JP2717720B2 (en) | Method for producing magnetic powder for magnetic recording medium | |
| JPH0825745B2 (en) | Method for producing magnetic powder | |
| JPS6127329B2 (en) | ||
| JPS6121921A (en) | Preparation of magnetic powder | |
| JPS6281007A (en) | Manufacture of magnetic powder | |
| JPH0518442B2 (en) |