JPS6331924B2 - - Google Patents
Info
- Publication number
- JPS6331924B2 JPS6331924B2 JP57216658A JP21665882A JPS6331924B2 JP S6331924 B2 JPS6331924 B2 JP S6331924B2 JP 57216658 A JP57216658 A JP 57216658A JP 21665882 A JP21665882 A JP 21665882A JP S6331924 B2 JPS6331924 B2 JP S6331924B2
- Authority
- JP
- Japan
- Prior art keywords
- phase
- magnetic
- particles
- magnetic recording
- ferrite
- 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
Links
- 230000005291 magnetic effect Effects 0.000 claims description 37
- 239000002245 particle Substances 0.000 claims description 32
- 239000006249 magnetic particle Substances 0.000 claims description 13
- 230000005415 magnetization Effects 0.000 claims description 12
- 238000000034 method Methods 0.000 claims description 10
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 7
- 238000004519 manufacturing process Methods 0.000 claims description 7
- 239000001301 oxygen Substances 0.000 claims description 7
- 229910052760 oxygen Inorganic materials 0.000 claims description 7
- 239000000843 powder Substances 0.000 claims description 6
- 239000002994 raw material Substances 0.000 claims description 6
- 229910052788 barium Inorganic materials 0.000 claims description 5
- 229910052712 strontium Inorganic materials 0.000 claims description 5
- 239000002184 metal Substances 0.000 claims description 4
- 229910052751 metal Inorganic materials 0.000 claims description 4
- 229910052793 cadmium Inorganic materials 0.000 claims description 3
- 229910052802 copper Inorganic materials 0.000 claims description 3
- 229910052742 iron Inorganic materials 0.000 claims description 3
- 229910052748 manganese Inorganic materials 0.000 claims description 3
- 150000002739 metals Chemical class 0.000 claims description 3
- 229910052759 nickel Inorganic materials 0.000 claims description 3
- 239000012299 nitrogen atmosphere Substances 0.000 claims description 3
- 229910052725 zinc Inorganic materials 0.000 claims description 3
- 229910052749 magnesium Inorganic materials 0.000 claims description 2
- 239000012071 phase Substances 0.000 description 32
- 229910000859 α-Fe Inorganic materials 0.000 description 25
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 11
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 9
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 8
- 230000027311 M phase Effects 0.000 description 8
- 238000010304 firing Methods 0.000 description 8
- 238000000227 grinding Methods 0.000 description 6
- 238000005516 engineering process Methods 0.000 description 5
- 239000000654 additive Substances 0.000 description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 238000004891 communication Methods 0.000 description 3
- 239000011347 resin Substances 0.000 description 3
- 229920005989 resin Polymers 0.000 description 3
- 238000004544 sputter deposition Methods 0.000 description 3
- 230000018199 S phase Effects 0.000 description 2
- 238000002441 X-ray diffraction Methods 0.000 description 2
- 230000000996 additive effect Effects 0.000 description 2
- AYJRCSIUFZENHW-UHFFFAOYSA-L barium carbonate Chemical compound [Ba+2].[O-]C([O-])=O AYJRCSIUFZENHW-UHFFFAOYSA-L 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 238000007740 vapor deposition Methods 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 1
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 238000000975 co-precipitation Methods 0.000 description 1
- 229910052681 coesite Inorganic materials 0.000 description 1
- 229910052906 cristobalite Inorganic materials 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 229910001882 dioxygen Inorganic materials 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 239000011019 hematite Substances 0.000 description 1
- 229910052595 hematite Inorganic materials 0.000 description 1
- LIKBJVNGSGBSGK-UHFFFAOYSA-N iron(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Fe+3].[Fe+3] LIKBJVNGSGBSGK-UHFFFAOYSA-N 0.000 description 1
- LDHBWEYLDHLIBQ-UHFFFAOYSA-M iron(3+);oxygen(2-);hydroxide;hydrate Chemical compound O.[OH-].[O-2].[Fe+3] LDHBWEYLDHLIBQ-UHFFFAOYSA-M 0.000 description 1
- 229910052745 lead Inorganic materials 0.000 description 1
- 239000006247 magnetic powder Substances 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 229910021645 metal ion Inorganic materials 0.000 description 1
- 239000011812 mixed powder Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000003973 paint Substances 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 238000004062 sedimentation Methods 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 238000003746 solid phase reaction Methods 0.000 description 1
- 239000011029 spinel Substances 0.000 description 1
- 229910052596 spinel Inorganic materials 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 229910052682 stishovite Inorganic materials 0.000 description 1
- 229910052905 tridymite Inorganic materials 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 229910052727 yttrium Inorganic materials 0.000 description 1
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/62—Record carriers characterised by the selection of the material
- G11B5/68—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent
- G11B5/70—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer
- G11B5/706—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material
- G11B5/70626—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material containing non-metallic substances
- G11B5/70642—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material containing non-metallic substances iron oxides
- G11B5/70678—Ferrites
Landscapes
- Magnetic Ceramics (AREA)
- Paints Or Removers (AREA)
- Magnetic Record Carriers (AREA)
- Hard Magnetic Materials (AREA)
Description
本発明は磁気記録媒体に関するもので、特に六
方晶フエライト粒子を磁性粒子に用いたしかも塗
布法によつて得られる高密度記録を可能とする磁
気記録媒体用粒子の製造法の提供にある。
磁気デイスクの出現以来、高密度な磁気記録の
技術が一層発展するとともに、数多くの研究機関
で研究がなされている。
これらについては、例えば日本応用磁気学会誌
Vol.3、No.2昭和54年、あるいは電子通信学会誌
Vol.63、No.41980年４月などで明らかであるが、
高密度磁気記録の技術の進歩は、記録媒体、磁気
ヘツド、位置決め方式、記録再生方式、機構等多
岐にわかる技術が蓄積されたものと言える。
高密度化には、記録媒体の長手方向に記録再生
する方式（以下、水平磁気録と呼ぶ）と、媒体に
垂直方向に行う方式（以下、垂直磁気記録と呼
ぶ）とが互いにしのぎを削つている。
このような高密度な磁気記録において、磁気記
録媒体の技術は磁気ヘツドの技術とともに大きな
ウエイトを占める。
高密度化の磁気媒体では、水平記録については
前出の電子通信学会誌（Vol.63、No.41980年月
末PP329〜）にあるように媒体の保磁力Hcを大
きくし、角形比を大きく、残留磁束密度Brと媒
体の厚さｔとしたときの積t.Brを小さくすること
が望まれる。一方、垂直磁化においては、媒体の
飽和磁化Msが高く、残留磁化を保持するための
高い保磁力Hc（水平磁化とは逆に、低密度側で必
要）が要求されるとともに、垂直磁化膜となる。
Hk4πMsまたはKu2πMs2 ……(1)
但し、Hk異方性磁界
Ku結晶性異方性定数
の条件が必要で、このためには前述とは逆にMs
が低くしなければならない。
また、これらの磁気媒体は、その媒体のみの特
性だけでなく、例えば電子通信学会研究会資料
MR82−15（1982、９月14日）あるいは同研究資
料MR82−19（1982、８月11日）で明らかなよう
に記録再生に使用する磁気ヘツドの特性を考慮し
なければならない。このようなことから、フエラ
イトをヘツドに用いた場合、磁気記録媒体の特性
は保磁力Hcは600〜1500エルステツド、飽和磁化
3000〜5000ガウスが好適と言われている。
このようなことから、本発明者らは、六角板状
を呈したＷ相フエライト粒子の磁化容易軸は板状
面に垂直な方向であるから、磁気配向させながら
ベーステープに塗布すれば、一軸異方性をとるこ
とができ、 IHCが600〜1500（O¨e）で、フエライ
粒子の単位重量当り飽和磁化モーメントσSが
60emu／gr以上の磁気記録媒体用の磁性粒子を提
供可能とするものである。
本発明によれば、一般式RMe2Fe16O27（但し、
ＲはBa、Sr、Crの一種又は二種以上の組み合わ
せであり、MeはFe、Cu、Zn、Cd、Ni、Mn、
Mgの二価金属の一種又は二種以上の組み合わ
せ）で表わされるＷ相酸化物磁性粒子よりなる磁
気記録媒体の製造方法において、上記一般式を満
足するように原料粉末を混合後、これを酸素分圧
（PO2）が10-2（atm）以下の窒素雰囲気中で、
1250℃以上の温度にて焼成し、その後0.01〜0.5μ
ｍの平均粒子径を有するように微粉砕して、保磁
力 IHCが600（Oe）以上、単位重量当りの飽和磁
化σSが60（e.m.u.／gr）以上を有する磁気記録媒
体用粒子の製造方法にある。
ここで、酸素分圧PO2が10-2より高いと、ま
た、焼成温度が1250℃未満では、Ｍ相、Ｈ相、Ｓ
相等の異相が発生し、Ｗ相単相のものが得られな
い。
六方晶フエライトは、例えば外国書
「Ferrites」（J.Smih、H.P.J.Wijn著、John
Willey and Sons1959）で明らかなように、
Ｍ相 BaFe12O19
Ｗ相 BaMc2Fe16O27
Ｙ相 Ba2Me2Fe12O22
Ｚ相 Ba2Me2Fe24O41
のように分類される。これら六方晶フエライトは
結晶構造が非常に類似し、フエライト磁石として
実用化されているＭ相以外のＷ、Ｙ、Ｚ相のフエ
ライト粒子はフエロツクス・プレーナと呼ばれて
いる。これら六晶フエライトではＭ相以外はあま
り実用に供されていない。
Ｍ相、いわゆるマグネツトプランバイト型フエ
ライト粒子粉末は焼結磁石及びゴム、プラスチツ
ク磁石の原料として使用されており、このような
フエライト磁石の特性は一般に粒度が数ミクロン
殊に１ミクロン程度であり保磁力 IHCは出来る
丈高いこと（一般には3000O¨e以上）並びにエネ
ルギー糧（BH）maxができるだけ大きなものが
要求される。
これに対し、磁気記録媒体用磁性粒子として
は、前述のような（磁性粒子として IHC、σSの）
磁性特性が必要であるとともに、記録媒体用とし
て使用される六角板状を呈した粒子粉末の特性と
しては粒度が出来るだけ微細で0.01〜0.5ミクロ
ン程度で、その値をもつことが重要である。これ
は、フエライト粒子と溶剤および樹脂バインダと
を混合して塗料化する際、フエライト微粒子の磁
化容易軸を磁場配向装置を用いてベースフイルム
に配向させ、記録密度を大幅に向上させるために
必要な条件である。
実施例をもちいて本発明をさらに説明する。
実施例 １
炭酸バリウムBaCO3と酸化鉄Fe2O3をモル比で
１：９モルとなるように原料を秤量し、全量を、
50grとしてメチルアルコール50c.c.とともに撹拌機
で１時間撹拌混合した後、自然乾燥して混合粉と
し、重量5.5grずつプレス成型し、1350℃で１時
間一次焼成した。この焼成では気密性炉心管を用
い、酸素ガスと窒素ガスを流して、酸素分圧Po2
＝１×10-4（atm）の雰囲気で行い、急冷した。
この焼成物をメノー鉢で325メツシユ下に粗粉
砕し、Ｘ線回折したところＷ相単相のフエライト
粒化が確認された。
さらにこのＷ相化したフエライト粉末120grと
メチルアルコールを混入してボールミルで粉砕し
た。粉砕時間毎に少量の粉末を採取して、粉末の
IHCとσSとの関係を示したのが第１図である。
Ｗ相では、粉砕時間とともにσSがやや低下する
が、保磁力 IHCはＴ＝168時間まで増加傾向にあ
り72時間以上になると IHC＝800（O¨e）となり、
Ｔ＝168時間では IHC＝1000（O¨e）となり、それ
以上はほぼ同じ値をとる。
電子顕微鏡で粒子の平均粒径を観察したところ
粉砕時間が90時間では平均粒子径は0.5μｍとな
り、それ以上ではさらに微細とな、312時間では
0.01から0.15μｍが分布する粒度であつた。
このように、粒子径が0.01〜0.5ミクロンにお
いて、σSが60emu／gr以上、 IHC＝600〜1500
（O¨e）の条件を満足できるフエライト粒子が得ら
れた。
なお図の IHCにおいて白点は磁化容易軸と平
行な場合、黒点は垂直な場合を示す。
実施例 ２
実施例１と同じ方法でBaO・9Fe2O3（＝
BaO2Fe〓O8Fe〓2O3）、SrO・9Fe2O3（＝SrO・
2Fe〓Ｏ・8Fe〓2O3）及びBaとSrとを夫々Caで置
換した（BaO）0.6（CaO）0.49Fe2O3〔＝（Ba0.6
Ca0.4）Ｏ・2Fe〓Ｏ・8Fe〓2O3〕、（SrO）0.6（CaO）0
.
４9Fe2O3〔＝（Sr0.6Ca0.4）Ｏ・2Fe〓Ｏ・8Fe〓2O3〕
の六方晶フエライト粒子を作製した。
一次焼成での酸素分圧Po2を変化した時の磁気
特性を第一表に示した。
同表から明らかなように、PO2が10-2（atm）
以下で、σSが（e.m.u.／gr）以上、 IHCが600Oe
以上のものが得られることがわかる。
実施例 ２
The present invention relates to magnetic recording media, and more particularly to a method for producing particles for magnetic recording media that uses hexagonal ferrite particles as magnetic particles and enables high-density recording obtained by a coating method. Since the advent of magnetic disks, high-density magnetic recording technology has further developed and research is being conducted at numerous research institutions. Regarding these, for example, see the Journal of the Japanese Society of Applied Magnetics.
Vol.3, No.2 1978, or Journal of the Institute of Electronics and Communication Engineers
As is clear from Vol.63, No.4 April 1980,
Advances in high-density magnetic recording technology can be said to be the result of the accumulation of a wide variety of technologies, including recording media, magnetic heads, positioning systems, recording and reproducing systems, and mechanisms. To achieve higher density, two methods are competing with each other: a method that records and plays in the longitudinal direction of the recording medium (hereinafter referred to as horizontal magnetic recording) and a method that performs recording and reproduction in the direction perpendicular to the medium (hereinafter referred to as perpendicular magnetic recording). There is. In such high-density magnetic recording, magnetic recording medium technology plays a large role along with magnetic head technology. For high-density magnetic media, for horizontal recording, the coercive force Hc of the medium is increased, the squareness ratio is increased, as stated in the above-mentioned Journal of the Institute of Electronics and Communication Engineers (Vol. 63, No. 4, PP 329 ~ end of 1980). It is desirable to reduce the product t.Br between the residual magnetic flux density Br and the medium thickness t. On the other hand, in perpendicular magnetization, the saturation magnetization Ms of the medium is high, and a high coercive force Hc (contrary to horizontal magnetization, required on the low density side) is required to maintain residual magnetization. Become. Hk4πMs or Ku2πMs 2 ...(1) However, the conditions of Hk anisotropy magnetic field Ku crystalline anisotropy constant are required, and for this purpose contrary to the above, Ms
must be low. In addition, these magnetic media are characterized not only by the characteristics of the medium alone, but also by the materials of the Institute of Electronics and Communication Engineers study group.
As is clear from MR82-15 (September 14, 1982) or the same research material MR82-19 (August 11, 1982), the characteristics of the magnetic head used for recording and reproduction must be taken into consideration. For this reason, when ferrite is used for the head, the characteristics of the magnetic recording medium are that the coercive force Hc is 600 to 1500 oersteds, and the saturation magnetization is
It is said that 3000 to 5000 Gauss is suitable. Based on this, the present inventors found that since the axis of easy magnetization of the hexagonal plate-shaped W-phase ferrite particles is perpendicular to the plate-like surface, if the magnetically oriented W-phase ferrite particles are coated on the base tape, the uniaxial It can be anisotropic, I H C is 600 to 1500 (O¨e), and the saturation magnetization moment σ S per unit weight of the Ferrite particles is
It is possible to provide magnetic particles for magnetic recording media of 60 emu/gr or more. According to the invention, the general formula RMe 2 Fe 16 O 27 (provided that
R is one or a combination of two or more of Ba, Sr, and Cr; Me is Fe, Cu, Zn, Cd, Ni, Mn,
In a method for manufacturing a magnetic recording medium made of W-phase oxide magnetic particles represented by Mg (one type or a combination of two or more divalent metals), raw material powders are mixed so as to satisfy the above general formula, and then mixed with oxygen. In a nitrogen atmosphere with a partial pressure (PO 2 ) of 10 -2 (atm) or less,
Fired at a temperature of 1250℃ or higher, then 0.01~0.5μ
Particles for magnetic recording media that are finely pulverized to have an average particle diameter of It's in the manufacturing method. Here, if the oxygen partial pressure PO 2 is higher than 10 -2 and the firing temperature is lower than 1250°C, M phase, H phase, S
Different phases occur, and a single W phase cannot be obtained. Hexagonal ferrite is described, for example, in the foreign book "Ferrites" (written by J.Smih, HPJWijn, John
Willey and Sons1959), it is classified as follows: M phase BaFe 12 O 19 W phase BaMc 2 Fe 16 O 27 Y phase Ba 2 Me 2 Fe 12 O 22 Z phase Ba 2 Me 2 Fe 24 O 41 . These hexagonal ferrites have very similar crystal structures, and ferrite particles of W, Y, and Z phases other than the M phase that are put into practical use as ferrite magnets are called ferrox planers. Among these hexcrystalline ferrites, phases other than the M phase are not put to practical use. M-phase, so-called magnetoplumbite-type ferrite particle powder, is used as a raw material for sintered magnets, rubber, and plastic magnets, and the characteristics of such ferrite magnets are that the particle size is generally several microns, especially about 1 micron, and it is difficult to maintain. Magnetic IHC is required to be as high as possible (generally 3000O¨e or more) and to have as large an energy source (BH) max as possible. On the other hand, as magnetic particles for magnetic recording media, the above-mentioned ( I H C , σ S as magnetic particles)
In addition to necessary magnetic properties, it is important that the grain size be as fine as possible, about 0.01 to 0.5 microns, as a characteristic of the hexagonal plate-shaped particles used for recording media. This is necessary to significantly improve recording density by orienting the axis of easy magnetization of ferrite particles to the base film using a magnetic field orientation device when mixing ferrite particles with a solvent and resin binder to form a paint. It is a condition. The present invention will be further explained using examples. Example 1 Raw materials were weighed so that the molar ratio of barium carbonate BaCO 3 and iron oxide Fe 2 O 3 was 1:9, and the total amount was
50 gr was stirred and mixed with 50 c.c. of methyl alcohol using a stirrer for 1 hour, air-dried to form a mixed powder, press-molded into 5.5 gr portions, and primarily fired at 1350°C for 1 hour. This firing uses an airtight furnace tube, flows oxygen gas and nitrogen gas, and raises the oxygen partial pressure Po 2
= 1×10 -4 (atm) and rapidly cooled. This fired product was coarsely ground in an agate bowl to a size of 325 mesh and subjected to X-ray diffraction, and it was confirmed that ferrite grains were formed in a single W phase. Furthermore, 120g of this W-phase ferrite powder was mixed with methyl alcohol and ground in a ball mill. Collect a small amount of powder at each grinding time and analyze the powder.
Figure 1 shows the relationship between I H C and σ S. In the W phase, σ S decreases slightly with the grinding time, but the coercive force I H C tends to increase until T = 168 hours, and after 72 hours, I H C = 800 (O¨e),
At T=168 hours, I H C =1000 (O¨e), and after that it takes almost the same value. When the average particle size of the particles was observed using an electron microscope, the average particle size was 0.5 μm when the grinding time was 90 hours, and it became even finer when the grinding time was longer than 90 hours.
The particle size ranged from 0.01 to 0.15 μm. In this way, when the particle size is 0.01 to 0.5 microns, σ S is 60 emu/gr or more, I H C = 600 to 1500
Ferrite particles satisfying the condition (O¨e) were obtained. Note that in the I H C in the figure, white dots indicate the case parallel to the axis of easy magnetization, and black dots indicate the case perpendicular. Example 2 BaO・9Fe 2 O 3 (=
BaO2Fe〓O8Fe〓 2 O 3 ), SrO・9Fe 2 O 3 (=SrO・
2Fe〓O・8Fe〓 2 O 3 ) and Ba and Sr were each replaced with Ca (BaO) 0.6 (CaO) 0.4 9Fe 2 O 3 [=(Ba 0.6
Ca 0.4 )O・2Fe〓O・8Fe〓 2 O 3 ], (SrO) 0.6 (CaO) 0
.
4 9Fe 2 O 3 [= (Sr 0.6 Ca 0.4 )O・2Fe〓O・8Fe〓 2 O 3 ]
Hexagonal ferrite particles were prepared. Table 1 shows the magnetic properties when the oxygen partial pressure Po 2 during primary firing was changed. As is clear from the table, PO 2 is 10 -2 (atm)
Below, σ S is (emu/gr) or more, I H C is 600 Oe
It can be seen that the above can be obtained. Example 2
【表】
実施例 ３
粉末BaCO3、ZnO、CuO、CdO、Fe2O3を出発
原料に用い、BaO・２（Zn1-xCux）Ｏ・8Fe2O3
〔以下（ZnCu）2W相〕及びBaO・２（Zn1-xCdx）
Ｏ・8Fe2O3〔以下（ZnCd）2W相〕となるよう夫々
原料を秤量し、らいかい機で30分間混合し、シリ
コニツト炉で1150℃の温度で１時間大気中で一次
焼成し、この後さらに粗粉砕後、らいかい機で15
分混合した後1.2×1.2cmの角板を個片重量5.5grに
て3.4tonの圧力で押圧し、1150℃×１時間、1200
℃×15分、1250℃×15分、1300℃×15分（酸素分
圧Po2が１×10-2（atm）の窒素雰囲気）で二次焼
成した。これらをＸ線回折した結果、前記組成の
（ZnCu）2W相および（ZnCd）2W相のいずれもｘ
に関係なく二次焼成が1150℃×１時間では、Ｍ相
とスピネル相（Ｓ相）が生成し、Ｗ相は、観察さ
れなかつた。
また、二次焼成温度が1200℃以上では、
（ZnCu）2W相、（ZnCd）2W相のフエライトのう
ち、二価金属でZnが含有しないものには、Ｗ相
が生成せず、Ｍ相、Ｓ相あるいはヘマタイト相
（以下Ｈ相）しかなかつた。Ｗ相単相とするには、
夫々のフエライトで前記ｘは０〜0.6が好適であ
る。
1250℃で二次焼成したものを、粗粉砕後、ボー
ルミルでメタノール中で微粉砕し、その時の六方
晶フエライト粒子の磁気特性を第２表に示す。[Table] Example 3 Using powdered BaCO 3 , ZnO, CuO, CdO, and Fe 2 O 3 as starting materials, BaO・2(Zn 1-x Cu x )O・8Fe 2 O 3
[Hereafter (ZnCu) 2 W phase] and BaO・2 (Zn 1-x Cd x )
The raw materials were weighed so as to form O.8Fe 2 O 3 [hereinafter referred to as (ZnCd) 2 W phase], mixed for 30 minutes in a sieve machine, and primary fired in air at a temperature of 1150°C for 1 hour in a siliconite furnace. After this, after further coarse grinding, 15
After mixing, a square plate of 1.2 x 1.2 cm was pressed with a pressure of 3.4 tons with an individual piece weight of 5.5 gr, and heated at 1150℃ x 1 hour at 1200℃.
Secondary firing was performed at 15 minutes at 1250°C, 15 minutes at 1300°C (in a nitrogen atmosphere with an oxygen partial pressure Po 2 of 1 x 10 -2 (atm)). As a result of X-ray diffraction of these, both the (ZnCu) 2 W phase and the (ZnCd) 2 W phase with the above composition were x
Regardless of the temperature, when the secondary firing was performed at 1150° C. for 1 hour, an M phase and a spinel phase (S phase) were formed, and a W phase was not observed. In addition, if the secondary firing temperature is 1200℃ or higher,
(ZnCu) 2 W phase, (ZnCd) 2 W phase ferrites, which are divalent metals and do not contain Zn, do not generate W phase, and instead have M phase, S phase, or hematite phase (hereinafter referred to as H phase). It was all I could do. To make W phase single phase,
For each ferrite, x is preferably 0 to 0.6. After secondary firing at 1250° C., the particles were coarsely pulverized and then finely pulverized in methanol using a ball mill, and the magnetic properties of the hexagonal ferrite particles are shown in Table 2.
【表】
（ZnCu）2W系及び（ZnCd）2W系フエライト
は、Ｍ相に比し、磁場配向がしやすく、また、残
留磁化の温度係数が小さく、磁気記録媒体用粒子
としては実用的価値が極めて大である。
実施例 ４
BaO2Fe〓Ｏ・8Fe〓2O3を主成分とするように、
原料BaCO3と、酸化鉄を秤量し、さらに
SiO20.5wt％とBaFe2O41wt％の添加物を添加し、
1250℃で１時間一次焼成した。但し1.0×10-3
（atm）の酸素分圧とするようN2ガスとO2ガスを
流した。
比較のため、添加物のあるものと含有しないも
のを併記した。なお添加したものは添加しないも
のよりは図のように少し IHCが小さくなるが、σS
は11〜20％の向上をもたらしている。
以上、本発明について説明したが、化学式
RMe2Fe16O27但しＲはBa、Sr、Pb、Caの一種、
又は二種以上の組合わせ、またMeはFe、Cu、
Zn、Cd、Ni、Mn、Mg等の二価金属イオンの一
種又は二種以上の組合わせで表わされるＷ相酸化
物磁性粒子を磁気記録媒体用の磁性粒子に用いる
ことにより高密度な磁気記録を可能とし、産業上
極めて有意義である。
なお、上記化学式RMe2Fe16O27はRO・２
（Me〓Ｏ）・8Fe2O3とも表わされるが、RO・ｕ
（MeO）・ｖ・Fe2O3とし（但し、ＲはBa、Sr、
Pb、Caの一種以上、Meは二価金属）、ｕ＝1.7〜
2.3、ｖ＝7.6〜8.4の領域も含まれる。これらはい
ずれもＷ相を示す。
また、これらの主成分の他にCaOあるいは
SiO2、BaFe2O4などの添加物を2wt％以下二次焼
成以前の工程で添加することによつても、 IHC、
σS及び粒径の制御に好適であり、本発明に含まれ
るものである。
前述したように、磁気テープの製造法には、現
在塗布法のほかに蒸着法とスパツタ法などがある
が、スパツタ法や蒸着法は高密度化が図れるが、
生産性や品質に問題があり、一般的には酸化鉄を
磁性粉とした塗布型テープが主流である。
本発明はこの生産性の極めて良い塗布型テープ
に用いるための磁性粒子で、超微粒子の六角板状
Ｗ相フエライト粒子を用い、従来の塗布型方法と
同じ製造設備を用いて樹脂に一様に分散し、塗布
するためのものである。
好ましくは六角板状フエライト粒子を磁気配向
させれば、さらに高密度ができる。さらに本発明
による磁性粒子は垂直磁気記録方式には最適であ
る。本発明の磁性粒子を従来の酸化鉄を用いた
VTRテープに比べ、磁気記録密度は50％以上向
上し、最適なものは２倍以上にも実現可能であ
る。
なお、本発明は、塗布法について述べたが、ス
パツタリング法による磁気記録媒体膜にも適用で
きるものである。
さらに、本発明は、粒子の作製を固相反応によ
る場合について述べたが、化学的によつて得られ
る、いわゆる、非沈法によつて得られる粒子にも
適用できる。共沈法による場合は、粒子の粒度分
布が均一であり、樹脂溶剤への分散が容易にでき
る点では有利である。[Table] Compared to the M phase, (ZnCu) 2 W-based and (ZnCd) 2 W-based ferrites are easier to align in a magnetic field and have a smaller temperature coefficient of residual magnetization, making them practical as particles for magnetic recording media. The value is extremely great. Example 4 BaO2Fe〓O・8Fe〓 So that 2 O 3 is the main component,
Weigh the raw materials BaCO 3 and iron oxide, and
Adding additives of 0.5wt% SiO2 and 1wt % BaFe2O4 ,
Primary firing was performed at 1250°C for 1 hour. However, 1.0×10 -3
N 2 gas and O 2 gas were flowed to maintain an oxygen partial pressure of (atm). For comparison, samples with and without additives are also shown. As shown in the figure, the I H C of the additive is slightly smaller than that of the non-additive, but σ S
has resulted in improvements of 11-20%. The present invention has been explained above, but the chemical formula
RMe 2 Fe 16 O 27 However, R is a type of Ba, Sr, Pb, Ca,
or a combination of two or more, and Me is Fe, Cu,
High-density magnetic recording is achieved by using W-phase oxide magnetic particles represented by one or a combination of two or more divalent metal ions such as Zn, Cd, Ni, Mn, and Mg as magnetic particles for magnetic recording media. It is extremely meaningful industrially. In addition, the chemical formula RMe 2 Fe 16 O 27 above is RO・2
It is also expressed as (Me〓O)・8Fe 2 O 3 , but RO・u
(MeO)・v・Fe 2 O 3 (where R is Ba, Sr,
Pb, one or more types of Ca, Me is a divalent metal), u=1.7~
2.3, the region of v=7.6 to 8.4 is also included. All of these exhibit W phase. In addition to these main components, CaO or
IHC , _ _ _
It is suitable for controlling σ S and particle size and is included in the present invention. As mentioned above, in addition to coating methods, there are currently methods for manufacturing magnetic tape, such as vapor deposition and sputtering methods. Although sputtering and vapor deposition methods can achieve higher density,
There are problems with productivity and quality, and in general, coated tapes made of iron oxide magnetic powder are mainstream. The present invention is a magnetic particle for use in this coating-type tape with extremely high productivity, using ultrafine hexagonal plate-shaped W-phase ferrite particles, and using the same manufacturing equipment as the conventional coating-type method, it can be uniformly applied to the resin. It is for dispersing and applying. Preferably, even higher density can be achieved by magnetically orienting the hexagonal plate-shaped ferrite particles. Furthermore, the magnetic particles according to the present invention are optimal for perpendicular magnetic recording systems. The magnetic particles of the present invention were made using conventional iron oxide.
Compared to VTR tape, the magnetic recording density has been improved by more than 50%, and in the optimal case it is possible to achieve more than double the density. Although the present invention has been described with respect to a coating method, it can also be applied to a magnetic recording medium film formed by a sputtering method. Furthermore, although the present invention has been described with respect to the case in which particles are produced by a solid phase reaction, it is also applicable to particles obtained by a so-called non-sedimentation method, which is obtained chemically. The coprecipitation method is advantageous in that the particles have a uniform particle size distribution and can be easily dispersed in a resin solvent.
第１図は本発明の実施例１で得られたBaO・
9Fe2O3とするＷ相磁性粒子の粉砕時間と保磁力 I
HCと飽和磁化σSとの関係を示す図。第２図は実
施例４でのＷ相磁性粒子の粉砕特性を示す図。
Figure 1 shows the BaO obtained in Example 1 of the present invention.
Grinding time and coercive force I of W-phase magnetic particles with 9Fe 2 O 3
A diagram showing the relationship between H C and saturation magnetization σ S. FIG. 2 is a diagram showing the crushing characteristics of W-phase magnetic particles in Example 4.
Claims (1)
Caの一種又は二種以上の組み合わせであり、Me
はFe、Cu、Zn、Cd、Ni、Mn、Mgの二価金属
の一種又は二種以上の組み合わせ）で表わされる
Ｗ相酸化物磁性粒子よりなる磁気記録媒体の製造
方法において、上記一般式を満足するように原料
粉末を混合後、これを酸素分圧（PO2）が10-2
（atm）以下の窒素雰囲気中で、1250℃以上の温
度にて焼成し、その後0.01〜0.5μｍの平均粒子径
を有するように微粉砕して、保磁力 IHCが600
（Oe）以上、単位重量当りの飽和磁化σSが60
（ｅ・ｍ・u.／gr）以上を有する磁気記録媒体用
粒子の製造方法。1 General formula RMe 2 Fe 16 O 27 (where R is Ba, Sr,
One or a combination of two or more types of Ca, Me
In the method for manufacturing a magnetic recording medium made of W-phase oxide magnetic particles represented by one or a combination of two or more divalent metals of Fe, Cu, Zn, Cd, Ni, Mn, and Mg, the above general formula is After mixing the raw material powder to a satisfactory level, the oxygen partial pressure (PO 2 ) is 10 -2
(ATM) or less in a nitrogen atmosphere at a temperature of 1250℃ or higher, and then finely pulverized to have an average particle size of 0.01 to 0.5μm, and the coercive force I H C is 600℃.
(Oe) or more, saturation magnetization σ S per unit weight is 60
(e・m・u./gr) or more, a method for producing particles for magnetic recording media.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57216658A JPS59106107A (en) | 1982-12-10 | 1982-12-10 | Magnetic recording medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57216658A JPS59106107A (en) | 1982-12-10 | 1982-12-10 | Magnetic recording medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59106107A JPS59106107A (en) | 1984-06-19 |
| JPS6331924B2 true JPS6331924B2 (en) | 1988-06-27 |
Family
ID=16691899
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP57216658A Granted JPS59106107A (en) | 1982-12-10 | 1982-12-10 | Magnetic recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59106107A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3537623A1 (en) * | 1985-10-23 | 1987-04-23 | Bayer Ag | FINE-PARTIC ISOMETRIC HEXAFERRITE PIGMENTS WITH W STRUCTURE, METHOD FOR THEIR PRODUCTION AND THEIR USE |
| US5358660A (en) * | 1988-01-14 | 1994-10-25 | Showa Denko Kabushiki Kaisha | Magnetic particles for perpendicular magnetic recording |
-
1982
- 1982-12-10 JP JP57216658A patent/JPS59106107A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59106107A (en) | 1984-06-19 |
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