JPH0712933B2 - Magnetic powder for magnetic recording - Google Patents
Magnetic powder for magnetic recordingInfo
- Publication number
- JPH0712933B2 JPH0712933B2 JP20888886A JP20888886A JPH0712933B2 JP H0712933 B2 JPH0712933 B2 JP H0712933B2 JP 20888886 A JP20888886 A JP 20888886A JP 20888886 A JP20888886 A JP 20888886A JP H0712933 B2 JPH0712933 B2 JP H0712933B2
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- magnetic powder
- magnetic
- coercive force
- magnetic recording
- present
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Description
【発明の詳細な説明】 (産業上の利用分野) 本発明は磁気記録用磁性粉に関し、更に詳しくは、高密
度磁気記録媒体用に適する微細な粒子からなる六方晶系
フェライト磁性粉に関するものである。TECHNICAL FIELD The present invention relates to magnetic powder for magnetic recording, and more specifically to hexagonal ferrite magnetic powder composed of fine particles suitable for high density magnetic recording media. is there.
(従来の技術) 近年、磁気記録に対する高密度化の要求に伴い磁気記録
媒体の厚味方向に磁界を記録する垂直磁気記録方式が注
目されている。このような垂直磁気記録方式において使
用される磁性材料は記録媒体表面に垂直な方向に磁化容
易軸を有することが必要である。(Prior Art) In recent years, along with a demand for higher density in magnetic recording, a perpendicular magnetic recording method for recording a magnetic field in a thickness direction of a magnetic recording medium has been attracting attention. The magnetic material used in such a perpendicular magnetic recording system must have an easy axis of magnetization in a direction perpendicular to the surface of the recording medium.
六方晶系で一軸磁化異方性を有するフェライト、例えば
Baフェライト(BaFe12O19)は六角板状の結晶であっ
て、板面に垂直な方向に磁化容易軸を有しており、塗布
膜タイプの垂直磁気記録用磁性材料として上記の要件を
満足するものである。該磁性材料としては適度な保磁力
(Hc,通常300〜2000Oe程度)とできるだけ大きな飽和磁
化(σs,少くとも40emu/g以上)を有している事、及び
磁性粉の平均粒子径は記録波長の関係から0.3μm以下
であり、かつ超常磁性の関係から0.01μm以上の範囲で
あることが必要である。この範囲では平均粒子径はノイ
ズの関係から小さい方が好ましい。Hexagonal ferrite with uniaxial magnetization anisotropy, for example
Ba ferrite (BaFe 12 O 19 ) is a hexagonal plate-shaped crystal that has an easy axis of magnetization in the direction perpendicular to the plate surface and satisfies the above requirements as a coating film type magnetic material for perpendicular magnetic recording. To do. The magnetic material must have an appropriate coercive force (Hc, usually about 300 to 2000 Oe) and a saturation magnetization as large as possible (σs, at least 40 emu / g or more), and the average particle diameter of the magnetic powder is the recording wavelength. It is necessary to be 0.3 μm or less from the above relationship and 0.01 μm or more from the superparamagnetic relationship. In this range, it is preferable that the average particle diameter is small in view of noise.
ところで、Baフェライトは保磁力が5000Oe以上であり、
このままでは磁気記録用磁性材料としては大きすぎるの
で、Feの一部をCo及びTiで置換して、保磁力を低下させ
る方法が提案されている(例えば特開昭55−86103号公
報、特開昭59−175707号公報、IEEE Trans.on Magn.,MA
G−18,16(1982)P.1122など)。By the way, Ba ferrite has a coercive force of 5000 Oe or more,
Since it is too large as a magnetic material for magnetic recording as it is, a method of substituting a part of Fe with Co and Ti to lower the coercive force has been proposed (for example, JP-A-55-86103, JP-A-55-86103). Sho 59-175707, IEEE Trans.on Magn., MA
G-18, 16 (1982) P.1122 etc.).
(発明が解決しようとする問題点) ところで、磁気記録用磁性材料として、必要とする保磁
力は、通常300〜2000Oe程度であるが、用いられる磁気
記録用磁性材料の用途等によって要求される保磁力の値
は異なるので、各々の用途に合わせて一定の値の保磁力
を有することが必要である。従って、保磁力を単に低下
させるだけでは不充分であり、用途に合わせて一定の保
磁力に制御されなければならない。(Problems to be Solved by the Invention) The coercive force required as a magnetic material for magnetic recording is usually about 300 to 2000 Oe, but the required coercive force is required depending on the use of the magnetic material for magnetic recording. Since the values of magnetic force are different, it is necessary to have a constant value of coercive force according to each application. Therefore, it is not enough to simply reduce the coercive force, and the coercive force must be controlled to a constant value according to the application.
Feの一部をCo及びTiで置換した公知の磁性粉は、構成元
素の組成比がほぼ同一であっても、保磁力や飽和磁化
は、第1表に示すとうり、全くまちまちである。このこ
とは、Feの一部をCo及びTiで置換したのでは、保磁力の
制御は不充分であることを示唆している。In the known magnetic powder in which a part of Fe is replaced with Co and Ti, the coercive force and the saturation magnetization are quite different, as shown in Table 1, even if the composition ratios of the constituent elements are almost the same. This suggests that the control of the coercive force is insufficient when a part of Fe is replaced with Co and Ti.
これを確認する目的で、本発明者は共沈法及び共沈−フ
ラックス法(共沈法の途中の工程で得られた共沈物にフ
ラックスを混入して高温焼成し、その後でフラックスを
水洗除去する方法を用いてFeの一部をCo及びTiで置換し
た磁気記録用六方晶フェライト磁性粉を製造し、これを
同一操作条件下で何回もくり返し、得られた磁性粉の保
磁力が一定の値に制御されているかどうかを試みた。For the purpose of confirming this, the present inventor has studied the coprecipitation method and the coprecipitation-flux method (mixing the flux with the coprecipitate obtained in the intermediate step of the coprecipitation method to perform high temperature firing, and then washing the flux with water. A hexagonal ferrite magnetic powder for magnetic recording in which a part of Fe was replaced by Co and Ti was produced by the removal method, and this was repeated many times under the same operating conditions. I tried to see if it was controlled to a constant value.
その結果、同一な操作条件で製造した場合でも、得られ
た六方晶系フェライトの保磁力,飽和磁化,粒径等は、
製造ロット毎にまちまちであり、特に保磁力のバラツキ
が顕著であった。As a result, even when manufactured under the same operating conditions, the coercive force, saturation magnetization, grain size, etc. of the obtained hexagonal ferrite are
There were variations in each production lot, and the variation in coercive force was particularly remarkable.
このことはFeの一部をCo及びTiで置換した六方晶系フェ
ライトの場合、製造工程中の通常の操作では制御できな
い様な部分的なわずかな条件の不均一性や、製造中の混
入する微小な不純物等によって、保磁力や飽和磁化が敏
感に影響を受けるためであると考えられる。This means that in the case of hexagonal ferrite in which a part of Fe is replaced with Co and Ti, there is a slight non-uniformity of the conditions that cannot be controlled by normal operation during the manufacturing process, and inclusion during manufacturing. It is considered that coercive force and saturation magnetization are sensitively affected by minute impurities and the like.
このことからFeの一部をCo及びTiで置換したのでは、通
常の共沈法や共沈−フラックス法では保磁力の制御は不
可能であることが判明した。From this, it was found that the coercive force cannot be controlled by the ordinary coprecipitation method or the coprecipitation-flux method when a part of Fe is replaced by Co and Ti.
(問題点を解決するための手段) 本発明者等は、従来のこの様な欠点のない垂直磁気記録
用磁性粉を開発すべく鋭意検討した結果、下記の一般組
成式で示される磁気記録用磁性粉が効果的であることを
見出し、本発明を完成するに至った。 (Means for Solving the Problems) The inventors of the present invention have earnestly studied to develop a magnetic powder for perpendicular magnetic recording that does not have such a conventional defect, and as a result, a magnetic recording medium represented by the following general composition formula The inventors have found that magnetic powder is effective and have completed the present invention.
すなわち、本発明により一般組成式 FeaCobTicMI dMII eMIII fOg (ここでMIはBa,Sr,Ca及びPbから選択される少なくとも
一種の金属元素を表わし、MIIはSi及び/またはSnを表
わし、MIIIはNi,Cu,V,Nb,Ta及びZrから選択される少な
くとも一種の元素を表わし、a,b,c,d,e,f及びgはそれ
ぞれFe,Co,Ti,MI,MII,MIII及びoの原子数であり、a
は8〜11.8、b及びcは0.05〜2.0、dは0.5〜3.0及び
e及びfは0.001〜3.0の値をとり、gは他の元素の原子
価を満足する酸素の原子数を表わす。)で表わされ、且
つ平均粒子径0.01〜0.3μmであることを特徴とする磁
気記録用磁性粉が提供される。That is, according to the present invention, the general composition formula Fe a Co b Ti c M I d M II e M III f O g (where M I represents at least one metal element selected from Ba, Sr, Ca and Pb, M II represents Si and / or Sn, M III represents at least one element selected from Ni, Cu, V, Nb, Ta and Zr, and a, b, c, d, e, f and g are The numbers of atoms of Fe, Co, Ti, M I , M II , M III and o, respectively,
8 to 11.8, b and c 0.05 to 2.0, d 0.5 to 3.0 and e and f 0.001 to 3.0, and g represents the number of oxygen atoms satisfying the valences of other elements. ) And having an average particle size of 0.01 to 0.3 μm, a magnetic powder for magnetic recording is provided.
本発明においては、磁性粉の各成分元素の原子数a〜g
が上記の数値範囲内にあることが必要で、この範囲外で
は磁気記録用磁性粉に適した保磁力や飽和磁化を持った
磁性粉は得られ難い。In the present invention, the number of atoms of each component element of the magnetic powder is a to g
Must be within the above numerical range, and outside this range, it is difficult to obtain a magnetic powder having a coercive force and saturation magnetization suitable for magnetic powder for magnetic recording.
好ましい磁性粉の各成分割合は、aは8〜11.8、b及び
cは0.1〜1.5、dは0.8〜2.0及びe及びfは0.005〜2.0
の値をとり、gは他の元素の原子価を満足する酸素の原
子数である。The ratio of each component of the magnetic powder is preferably 8 to 11.8 for a, 0.1 to 1.5 for b and c, 0.8 to 2.0 for d, and 0.005 to 2.0 for e and f.
And g is the number of oxygen atoms satisfying the valences of other elements.
本発明の磁性粉は、製造方法あるいは製造条件などによ
っては、得られる磁性粉粒子の結晶が正常な六角板状を
呈していない粒子が混在している場合もあるが、該原子
数が本発明の範囲内であれば、本発明の目的を充分に達
成することができる。In the magnetic powder of the present invention, depending on the production method or production conditions, there may be mixed particles in which the crystals of the obtained magnetic powder particles do not have a normal hexagonal plate shape, but the number of atoms is the present invention. Within the range, the object of the present invention can be sufficiently achieved.
かかる本発明磁性粉によれば、製造操作条件を同一にし
た場合のロット間の磁性粉特性のバラツキは殆んどみら
れず、磁気記録用磁性粉として具備されていなければな
らない保磁力を有することはもちろんであり、更に優れ
た飽和磁化を有すると共に平均粒径が小さい特徴を有し
ている。このことは、本発明に係る磁性粉が従来のCo及
びTiを含む磁性粉とは全く異なる機能を具備しているこ
とによるものと考えられる。According to the magnetic powder of the present invention, there is almost no variation in the characteristics of the magnetic powder between lots when the manufacturing operation conditions are the same, and the magnetic powder has a coercive force that must be provided as magnetic powder for magnetic recording. Needless to say, it is characterized by having a further excellent saturation magnetization and having a small average particle size. This is considered to be because the magnetic powder according to the present invention has a completely different function from the conventional magnetic powder containing Co and Ti.
本発明による磁性粉は、この分野で公知のいろいろの方
法、例えば、ガラス結晶化法、共沈法、フラックス法、
水熱合成法等によって製造することができる。特に共沈
法及び共沈法の途中の工程で得られた共沈物に、水溶性
のフラックスを混入して高温焼成し、その後でフラック
スを水洗除去する共沈−フラックス法に適している。The magnetic powder according to the present invention may be obtained by various methods known in the art, for example, a glass crystallization method, a coprecipitation method, a flux method,
It can be produced by a hydrothermal synthesis method or the like. In particular, it is suitable for a coprecipitation method and a coprecipitation-flux method in which a water-soluble flux is mixed with a coprecipitate obtained in a step in the middle of the coprecipitation method, the mixture is baked at a high temperature, and then the flux is washed and removed.
本発明の磁性粉の製造について、共沈法及び共沈フラッ
クス法を例にして述べると次のとうりである。The production of the magnetic powder of the present invention will be described below by taking the coprecipitation method and the coprecipitation flux method as an example.
すなわち、本発明にかかわる磁性粉を構成する各金属元
素の原料化合物としては、酸化物、オキシ水酸化物、水
酸化物、アンモニウム塩、硝酸塩、硫酸塩、炭酸塩、有
機酸塩、ハロゲン化物アルカリ金属塩等の塩類、遊離
酸、酸無水物、縮合酸等を挙げることができる。特に水
溶性化合物が好ましい。各金属元素の原料化合物は、水
溶液となる様に水に混合溶解されることが好ましい。ま
た、アルカリ水溶液に混合溶解した方が都合がよい場合
には、後述のアルカリ水溶液中に混合溶解される。That is, as a raw material compound of each metal element constituting the magnetic powder according to the present invention, oxides, oxyhydroxides, hydroxides, ammonium salts, nitrates, sulfates, carbonates, organic acid salts, alkali halides Examples thereof include salts such as metal salts, free acids, acid anhydrides and condensed acids. Water-soluble compounds are particularly preferable. The raw material compounds of the respective metal elements are preferably mixed and dissolved in water so as to form an aqueous solution. When it is more convenient to mix and dissolve in an alkaline aqueous solution, it is mixed and dissolved in an alkaline aqueous solution described later.
一方アルカリ水溶液に用いるアルカリ成分としては、水
溶性のものであればよく、アルカリ金属の水酸化物や炭
酸塩、アンモニア、炭酸アンモニウム等が挙げられる。
例えばNaOH,Na2CO3,NaHCO3,KOH,K2CO3,NH4OH,(NH4)2
CO3等が用いられ、特に水酸化物と炭酸塩の併用が賞用
される。On the other hand, the alkali component used in the alkaline aqueous solution may be any water-soluble one, and examples thereof include alkali metal hydroxides and carbonates, ammonia, and ammonium carbonate.
For example, NaOH, Na 2 CO 3 , NaHCO 3 , KOH, K 2 CO 3 , NH 4 OH, (NH 4 ) 2
CO 3 and the like are used, and the combination of hydroxide and carbonate is especially prized.
しかして、上記金属イオン水溶液とアルカリ水溶液とを
混合し、共沈物を生ぜしめる。得られた共沈物は、充分
に水洗した後別する。この様にして得られたケーキ状
ないしスラリー状の共沈物は、共沈法による場合には、
これを乾燥後、600〜1100℃で10分〜30時間高温焼成し
て、該当する六方晶系フェライト磁性粉を得る。また共
沈−フラックス法による場合には、共沈物に水溶性フラ
ックス(例えば、塩化ナトリウムや塩化カリウム等のハ
ロゲン化アルカリ金属塩、塩化バリウムや塩化ストロン
チウム等のハロゲン化アルカリ土類金属塩、硫酸ナトリ
ウム、硫酸カリウム、硝酸ナトリウム、硝酸カリウム、
及びこれ等の混合物等)を適当量加えてこれを乾燥後、
600〜1100℃で10分〜30時間高温焼成した後、水溶性フ
ラックスを水または、酸水溶液で洗浄別し、必要に応
じ更に水洗した後乾燥して該当する六方晶系フェライト
磁性粉を得る。Then, the metal ion aqueous solution and the alkaline aqueous solution are mixed to form a coprecipitate. The coprecipitate thus obtained is thoroughly washed with water and then separated. The cake-like or slurry-like coprecipitate thus obtained is, in the case of the coprecipitation method,
After drying, it is baked at 600 to 1100 ° C for 10 minutes to 30 hours at high temperature to obtain the corresponding hexagonal ferrite magnetic powder. In the case of the coprecipitation-flux method, the coprecipitate contains a water-soluble flux (for example, an alkali metal halide such as sodium chloride or potassium chloride, an alkaline earth metal halide such as barium chloride or strontium chloride, or a sulfuric acid). Sodium, potassium sulfate, sodium nitrate, potassium nitrate,
And a mixture of these, etc.) is added and dried,
After firing at 600 to 1100 ° C for 10 minutes to 30 hours at high temperature, the water-soluble flux is washed with water or an acid aqueous solution, washed with water if necessary, and dried to obtain the corresponding hexagonal ferrite magnetic powder.
以上、共沈法及び共沈フラックス法を例にして本発明の
磁性粉の製造の具体例を示したが、もちろん製造された
磁性粉が本発明にかかわる一般組成式で示される磁性粉
であれば、いかなる方法によって製造してもよい。Although the specific examples of the production of the magnetic powder of the present invention have been described above by taking the coprecipitation method and the coprecipitation flux method as an example, it goes without saying that the produced magnetic powder may be the magnetic powder represented by the general composition formula of the present invention. However, it may be manufactured by any method.
(発明の効果) 本発明に係る磁性粉は六方晶C面に磁化容易軸を有する
板状粒子であり、同一の操作条件で製造した場合にロッ
ト間でのバラツキが非常に少ないばかりでなく、Feの一
部をCo及びTiで置換した公知の磁性粉よりも飽和磁化が
大きく、平均粒径の小さいものが得られるので、磁気記
録用磁性材料として好適である。(Effect of the invention) The magnetic powder according to the present invention is a plate-like particle having an easy axis of magnetization in the hexagonal C plane, and when manufactured under the same operating conditions, not only there is very little variation among lots, It is suitable as a magnetic material for magnetic recording because it has a saturation magnetization larger than that of a known magnetic powder obtained by substituting a part of Fe with Co and Ti and has a smaller average particle size.
(実施例) 以下に実施例を挙げて、本発明をさらに具体的に説明す
る。なお実施例中の保磁力及び飽和磁化は、VSM(振動
式磁気測定装置)を用い最大印加磁場10KOeで測定し
た。平均粒子径は、透過型電子顕微鏡で得られた写真か
ら400個の粒子の最大直径を測定し算術平均により算出
した。(Example) Hereinafter, the present invention will be described more specifically with reference to Examples. The coercive force and the saturation magnetization in the examples were measured with a maximum applied magnetic field of 10 KOe using a VSM (vibrating magnetometer). The average particle diameter was calculated by calculating the maximum diameter of 400 particles from a photograph obtained with a transmission electron microscope and calculating the arithmetic mean.
また、実施例中に示す磁性粉の組成式は、原料調製時の
各元素の原子比を用いている。磁性粉成分中の酸素の表
示については、簡略化のため省略した。Further, the composition formula of the magnetic powder shown in the examples uses the atomic ratio of each element at the time of preparing the raw materials. The display of oxygen in the magnetic powder component is omitted for simplification.
実施例1 BaCl2・2H2O0.55モル、TiCl40.375モル、CoCl2・6H2O0.
375モル、CuCl2・2H2O0.1モル及びFeCl3・6H2O5.25モル
を10lの蒸留水にこの順に溶解し、これをA液とした。Example 1 BaCl 2 .2H 2 O 0.55 mol, TiCl 4 0.375 mol, CoCl 2 .6H 2 O 0.
375 mol, CuCl 2 .2H 2 O 0.1 mol, and FeCl 3 .6H 2 O 5.25 mol were dissolved in this order in 10 l of distilled water to obtain a solution A.
NaOH17.5モル、Na2CO34.72モル、及びNa2SiO3・9H2O0.2
モルを15lの室温の蒸留水に溶解し、これをB液とし
た。50℃に熱したA液にB液を徐々に加えた後、50℃で
16時間攪拌した。攪拌後のpHは10.25であった。こうし
て得られた共沈物を別し、水洗した後150℃で乾燥
し、880℃で1.5時間電気炉で焼成した。こうして得られ
たBa−フェライトは Ba1.1Fe10.5Co0.75Ti0.75Si0.4Cu0.2で示される。NaOH 17.5 mol, Na 2 CO 3 4.72 mol, and Na 2 SiO 3 · 9H 2 O0.2
The mol was dissolved in 15 l of room temperature distilled water, and this was designated as solution B. After slowly adding Solution B to Solution A heated to 50 ℃, at 50 ℃
It was stirred for 16 hours. The pH after stirring was 10.25. The coprecipitate thus obtained was separated, washed with water, dried at 150 ° C., and fired at 880 ° C. for 1.5 hours in an electric furnace. The Ba-ferrite thus obtained is represented by Ba 1.1 Fe 10.5 Co 0.75 Ti 0.75 Si 0.4 Cu 0.2 .
同様の操作を5回くり返し行い、ロット毎の磁性粉の平
均粒径,保磁力,及び飽和磁化のバラツキを調べた。結
果を第2表に示す。The same operation was repeated 5 times, and the variations in the average particle size, coercive force, and saturation magnetization of the magnetic powder for each lot were examined. The results are shown in Table 2.
第2表から本発明に係る磁性粉は、ロット間のバラツキ
が非常に小さいばかりでなく、比較例1と比べて平均粒
径が小さく、飽和磁化が大きいことがわかる。It can be seen from Table 2 that the magnetic powder according to the present invention has not only a very small variation among lots but also a smaller average particle size and a larger saturation magnetization as compared with Comparative Example 1.
比較例1 メタケイ酸ナトリウム及び塩化第二銅を除いた他は、実
施例1と全く同様の方法でBa−フェライトを製造した。
得られたBa−フェライトはBa1.1Fe10.5Co0.75Ti0.75で
示される。 Comparative Example 1 Ba-ferrite was produced in the same manner as in Example 1 except that sodium metasilicate and cupric chloride were omitted.
The obtained Ba-ferrite is represented by Ba 1.1 Fe 10.5 Co 0.75 Ti 0.75 .
同様の操作を5回くり返して行い、ロット毎の磁性粉の
平均粒径,保磁力,及び飽和磁化のバラツキを調べた。
結果を第3表に示す。The same operation was repeated 5 times to examine the variations in the average particle size, coercive force, and saturation magnetization of the magnetic powder for each lot.
The results are shown in Table 3.
第3表から公知の磁性粉は、ロット間のバラツキが非常
に大きく、実施例1の本発明の如き通常の操作では、保
磁力の制御は不可能であることがわかる。It can be seen from Table 3 that the known magnetic powder has a very large lot-to-lot variation, and the coercive force cannot be controlled by the normal operation of the present invention of Example 1.
実施例2 実施例1で得られた共沈物を別し、水洗して得られた
ケーキ状の共沈物スラリーにフラックスとしてNaCl400g
を加え、充分に混合した後水分を蒸発乾固せしめ、これ
を870℃で1.5時間電気炉で焼成した。この焼成物を水を
用いて可溶物がなくなるまで洗浄した後、過,乾燥し
て実施例1と同様の組成式で示されるBa−フェライトを
得た。 Example 2 The coprecipitate obtained in Example 1 was separated and washed with water to obtain a cake-like coprecipitate slurry, and 400 g of NaCl was used as a flux.
Was added and mixed well, and then the water content was evaporated to dryness, and this was baked in an electric furnace at 870 ° C. for 1.5 hours. The calcined product was washed with water until the soluble matter disappeared, and then dried and dried to obtain Ba-ferrite having the same composition formula as in Example 1.
共沈物のケーキを製造する段階から同様の操作を5回く
り返し行い、ロット毎の磁性粉の平均粒径,保磁力及び
飽和磁化のバラツキを調べた。結果を第4表に示す。The same operation was repeated 5 times from the step of producing the coprecipitate cake, and the variations in the average particle size, coercive force, and saturation magnetization of the magnetic powder for each lot were examined. The results are shown in Table 4.
第4表から、本発明に係る磁性粉はロット間のバラツキ
の少い、均一な磁性粉が得られることがわかる。It can be seen from Table 4 that the magnetic powder according to the present invention can be obtained as a uniform magnetic powder with less variation among lots.
比較例2 比較例1のロット番号C1−1で得られた共沈物を用い
て、実施例2と同様の操作を5回くり返して行い、ロッ
ト毎の磁性粉の平均粒径,保磁力及び飽和磁化のバラツ
キを調べた。結果を第5表に示す。本比較例においては
いずれのロットにおいても同一共沈物を用いたにもかか
わらず、公知の組成を有する磁性粉は、ロット間のバラ
ツキが非常に大きく、本発明の実施例2の如き通常の操
作では、保磁力の制御は不可能であった。 Comparative Example 2 Using the coprecipitate obtained in Lot No. C1-1 of Comparative Example 1, the same operation as in Example 2 was repeated 5 times, and the average particle size of the magnetic powder, the coercive force and The variation of saturation magnetization was investigated. The results are shown in Table 5. Even though the same coprecipitate was used in all the lots in this comparative example, the magnetic powder having a known composition had a very large variation among lots, and thus the magnetic powder having the same composition as that of Example 2 of the present invention was used. In operation, the coercive force could not be controlled.
実施例3 NaOH量を10.0モルとした他は、実施例1と同様にしてA
液及びB液を調製した。 Example 3 A was the same as in Example 1 except that the amount of NaOH was 10.0 mol.
Solution and Solution B were prepared.
50℃に熱したA液とB液を混合し、これを蒸発皿に入
れ、含水率50%となるまで、充分攪拌しながら水分を蒸
発させた。これを更に乾燥器で充分に乾燥した後、870
℃で1.5時間電気炉で焼成した。この焼成物を水を用い
て可溶物がなくなるまで洗浄した後、過,乾燥して実
施例1と同様の組成式で示される。Ba−フェライトを得
た。Liquids A and B heated to 50 ° C. were mixed, placed in an evaporation dish, and water was evaporated with sufficient stirring until the water content became 50%. After further drying this in a dryer, 870
It was baked in an electric furnace at 1.5 ° C for 1.5 hours. The calcined product is washed with water until the soluble product is removed, dried and dried, and the compositional formula similar to that of Example 1 is shown. Ba-ferrite was obtained.
こうして得られた微粒子粉末は、平均粒径0.08μmの板
状であり、保磁力は847Oe、飽和磁化は53emu/gであっ
た。The fine particle powder thus obtained was plate-shaped with an average particle size of 0.08 μm, the coercive force was 847 Oe, and the saturation magnetization was 53 emu / g.
また同様の操作を5回くり返して実験を行ったところ、
ロット毎の磁性粉の平均粒径,及び飽和磁化はいずれも
上記と同一値であり、また保磁力のバラツキは、±1.5
%以内と非常に小さかった。In addition, when the same operation was repeated 5 times and an experiment was conducted,
The average particle size and saturation magnetization of the magnetic powder for each lot are the same as above, and the variation of coercive force is ± 1.5.
It was very small, within%.
実施例4〜23 MI成分,MII成分,MIII成分及び各金属成分の組成比を
変えた他は、実施例2と同様の方法によって第6表に示
す磁性粉を調製した。なおMI成分の原料は、塩化物を使
用し、MII成分の原料は、Siはメタケイ酸ナトリウム,Sn
は塩化物を使用し、MIII成分の原料としてVはアンモニ
ウム塩を、Nb及びTaは酸化物を、Ni及びZrは硝酸塩を、
Cuは塩化物または水酸化物を使用した。Si及びVの原料
化合物は、アルカリ水溶液中に溶解した。Examples 4 to 23 Magnetic powders shown in Table 6 were prepared in the same manner as in Example 2 except that the composition ratios of the M I component, the M II component, the M III component and each metal component were changed. The raw material for the M I component is chloride, and the raw material for the M II component is Si for sodium metasilicate, Sn.
Is a chloride, V is an ammonium salt, Nb and Ta are oxides, Ni and Zr are nitrates as raw materials for the M III component,
For Cu, chloride or hydroxide was used. The raw material compounds of Si and V were dissolved in an alkaline aqueous solution.
また、第6表に示す磁性粉の各々について、同一操作に
よる5回のくり返し実験を行いロット毎の磁性粉の平均
粒径,保磁力,及び飽和磁化のバラツキについても調べ
たが、いずれも、ロット間のバラツキは実施例2と同程
度の範囲であり、非常に小さかった。Further, with respect to each of the magnetic powders shown in Table 6, the experiment was repeated 5 times by the same operation, and the variations in the average particle size, the coercive force, and the saturation magnetization of the magnetic powders from lot to lot were also investigated. The variation between lots was in the same range as in Example 2, and was extremely small.
Claims (1)
径0.01〜0.3μmであることを特徴とする磁気記録用磁
性粉 FeaCobTicMI dMII eMIII fOg (ここでMIはBa,Sr,Ca及びPbから選択される少なくとも
一種の金属元素を表わし、MIIはSi及び/またはSnを表
わし、MIIIはNi,Cu,V,Nb,Ta及びZrから選択される少な
くとも一種の元素を表わし、a,b,c,d,e,f及びgはそれ
ぞれFe,Co,Ti,MI,MII,MIII及びOの原子数であり、a
は8〜11.8、b及びcは0.05〜2.0、dは0.5〜3.0及び
e及びfは0.001〜3.0の値をとり、gは他の元素の原子
価を満足する酸素の原子数である。)。1. A magnetic powder for magnetic recording Fe a Co b Ti c M I d M II e M III f represented by the following general composition formula and having an average particle diameter of 0.01 to 0.3 μm. O g (where M I represents at least one metal element selected from Ba, Sr, Ca and Pb, M II represents Si and / or Sn, and M III represents Ni, Cu, V, Nb, Ta And at least one element selected from Zr, where a, b, c, d, e, f and g are the numbers of Fe, Co, Ti, M I , M II , M III and O atoms, respectively, a
Is 8 to 11.8, b and c are 0.05 to 2.0, d is 0.5 to 3.0, and e and f are 0.001 to 3.0, and g is the number of oxygen atoms satisfying the valences of other elements. ).
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP20888886A JPH0712933B2 (en) | 1986-09-05 | 1986-09-05 | Magnetic powder for magnetic recording |
US07/092,210 US4820433A (en) | 1986-09-05 | 1987-09-02 | Magnetic powder for magnetic recording |
DE19873729497 DE3729497A1 (en) | 1986-09-05 | 1987-09-03 | MAGNETIC POWDER FOR MAGNETIC RECORDING |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP20888886A JPH0712933B2 (en) | 1986-09-05 | 1986-09-05 | Magnetic powder for magnetic recording |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS6364922A JPS6364922A (en) | 1988-03-23 |
JPH0712933B2 true JPH0712933B2 (en) | 1995-02-15 |
Family
ID=16563783
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP20888886A Expired - Lifetime JPH0712933B2 (en) | 1986-09-05 | 1986-09-05 | Magnetic powder for magnetic recording |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH0712933B2 (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2585243B2 (en) * | 1987-02-06 | 1997-02-26 | 株式会社東芝 | Magnetic powder for high density magnetic recording and magnetic recording medium using the same |
WO2015083697A1 (en) | 2013-12-04 | 2015-06-11 | 三菱重工業株式会社 | Squeeze film damper, bearing unit, and turbine |
-
1986
- 1986-09-05 JP JP20888886A patent/JPH0712933B2/en not_active Expired - Lifetime
Also Published As
Publication number | Publication date |
---|---|
JPS6364922A (en) | 1988-03-23 |
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