JPS63114201A - Manufacture of super-fine barium ferrite grain - Google Patents
Manufacture of super-fine barium ferrite grainInfo
- Publication number
- JPS63114201A JPS63114201A JP61260352A JP26035286A JPS63114201A JP S63114201 A JPS63114201 A JP S63114201A JP 61260352 A JP61260352 A JP 61260352A JP 26035286 A JP26035286 A JP 26035286A JP S63114201 A JPS63114201 A JP S63114201A
- Authority
- JP
- Japan
- Prior art keywords
- barium ferrite
- barium
- temperature
- grain
- magnetic recording
- 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
Links
- AJCDFVKYMIUXCR-UHFFFAOYSA-N oxobarium;oxo(oxoferriooxy)iron Chemical compound [Ba]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O AJCDFVKYMIUXCR-UHFFFAOYSA-N 0.000 title claims abstract description 27
- 238000004519 manufacturing process Methods 0.000 title claims description 7
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 14
- 238000010438 heat treatment Methods 0.000 claims abstract description 10
- 238000002844 melting Methods 0.000 claims abstract description 9
- 230000008018 melting Effects 0.000 claims abstract description 9
- 229910001854 alkali hydroxide Inorganic materials 0.000 claims abstract description 6
- 150000008044 alkali metal hydroxides Chemical class 0.000 claims abstract description 6
- 229910052788 barium Inorganic materials 0.000 claims abstract description 5
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 claims abstract description 5
- 238000006243 chemical reaction Methods 0.000 claims abstract description 5
- 239000000203 mixture Substances 0.000 claims abstract description 5
- 239000002002 slurry Substances 0.000 claims abstract description 5
- 229910052742 iron Inorganic materials 0.000 claims abstract description 4
- 229910052751 metal Inorganic materials 0.000 claims abstract description 3
- 239000002184 metal Substances 0.000 claims abstract description 3
- 150000003839 salts Chemical class 0.000 claims abstract description 3
- 239000002245 particle Substances 0.000 claims description 12
- 239000002244 precipitate Substances 0.000 claims description 6
- 239000000843 powder Substances 0.000 abstract description 14
- 239000000463 material Substances 0.000 abstract description 6
- 238000003756 stirring Methods 0.000 abstract description 5
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 9
- 238000000034 method Methods 0.000 description 8
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- 239000007864 aqueous solution Substances 0.000 description 5
- 230000000694 effects Effects 0.000 description 4
- VCJMYUPGQJHHFU-UHFFFAOYSA-N iron(3+);trinitrate Chemical compound [Fe+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O VCJMYUPGQJHHFU-UHFFFAOYSA-N 0.000 description 4
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- 238000001027 hydrothermal synthesis Methods 0.000 description 3
- 238000010335 hydrothermal treatment Methods 0.000 description 3
- 230000005415 magnetization Effects 0.000 description 3
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 2
- 239000003513 alkali Substances 0.000 description 2
- RQPZNWPYLFFXCP-UHFFFAOYSA-L barium dihydroxide Chemical compound [OH-].[OH-].[Ba+2] RQPZNWPYLFFXCP-UHFFFAOYSA-L 0.000 description 2
- 229910001863 barium hydroxide Inorganic materials 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- UFMZWBIQTDUYBN-UHFFFAOYSA-N cobalt dinitrate Chemical compound [Co+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O UFMZWBIQTDUYBN-UHFFFAOYSA-N 0.000 description 2
- 229910001981 cobalt nitrate Inorganic materials 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 238000005245 sintering Methods 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- XJDNKRIXUMDJCW-UHFFFAOYSA-J titanium tetrachloride Chemical compound Cl[Ti](Cl)(Cl)Cl XJDNKRIXUMDJCW-UHFFFAOYSA-J 0.000 description 2
- 239000011882 ultra-fine particle Substances 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 229910052787 antimony Inorganic materials 0.000 description 1
- 150000001805 chlorine compounds Chemical class 0.000 description 1
- 239000011362 coarse particle Substances 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 150000004679 hydroxides Chemical class 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 239000006247 magnetic powder Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 150000002823 nitrates Chemical class 0.000 description 1
- 229910052573 porcelain Inorganic materials 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 1
- 229910052715 tantalum Inorganic materials 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、磁気記録用の微粒子状バリウムフェライトご
製造する方法に関する。DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing fine particulate barium ferrite for magnetic recording.
特に、水熱合成法の改良による高密度磁気記録用の微粒
子状バリウムフェライトを製造する方法に関するもので
ある。In particular, the present invention relates to a method for producing particulate barium ferrite for high-density magnetic recording by improving a hydrothermal synthesis method.
バリウムフェライトは高保持力特性？利用して、従来よ
り永久磁石材料として広く用いられてきたが、年々記録
の高密度化指向が高まる中で、垂直磁気記録という高密
度化でさる新しい記録方式が提唱されてから、その材料
の一つとして一躍注目され、研究開発が進行中である。Does barium ferrite have high coercivity? It has traditionally been widely used as a permanent magnet material, but as the trend towards higher density recording increases year by year, a new recording method called perpendicular magnetic recording with higher density was proposed, It has quickly attracted attention, and research and development is currently underway.
バリウムフェライト粉末は六角板状結晶であり、磁化容
易軸が板面に対して垂直方向にあるので、垂直磁気記録
方式には理想的な材料である。Barium ferrite powder is a hexagonal plate-shaped crystal with an axis of easy magnetization perpendicular to the plate surface, making it an ideal material for perpendicular magnetic recording.
又、従来より実績のある塗布方式に使用でさることから
、これまで蓄積された塗布技術が活用でき、量産性に優
れ且つ安価であるというメリットがある。Furthermore, since it can be used in a coating method that has been proven in the past, it has the advantage of being able to utilize the coating techniques that have been accumulated up to now, being superior in mass production, and being inexpensive.
しかし、従来法によるバリウムフェライト粉末のま＼で
は保磁力が５００００ｅ以上と高過ぎて、磁気記録用と
しては使えない為、通常Ｅａｓｅ Ｏ（７）Ｆｅの一
部’５；ＡｌＴｉ、Ｃｏ ％ Ｍｎ ｓ Ｏｒ ％ Ｎ
ｉ、Ｃｕ、Ｚｎ。However, barium ferrite powder produced by the conventional method has a coercive force that is too high (more than 50,000e) and cannot be used for magnetic recording. Or%N
i, Cu, Zn.
Ｎｂ、 Ｓｂ、 Ｔａなどの一種以上で置換して磁気記
録用に適した保磁力（５００〜１５０００ｅ）に調整し
ている。The coercive force (500 to 15,000 e) suitable for magnetic recording is adjusted by substituting one or more of Nb, Sb, Ta, etc.
バリウムフェライト粉末を高密度磁気記録材料として用
いる場合には、粒径が０．１μｍ以下で粒度分布が狭く
均一で、且つ粒子の凝集、焼結がないことが必要である
が、従来より知られている水熱合成法では種々の欠点が
あり、未だ満足できる材料を得るに至っていない。When using barium ferrite powder as a high-density magnetic recording material, it is necessary to have a particle size of 0.1 μm or less, a narrow and uniform particle size distribution, and no agglomeration or sintering of the particles. The hydrothermal synthesis method currently used has various drawbacks, and a satisfactory material has not yet been obtained.
本発明の目的は、上記の欠点がなく優れた微粒子の磁気
記録用バリウム７エライトコ製造する方法、特に水熱合
成法の改良による高密度垂直磁気記録用の微粒子状バリ
ウムフェライトを製造する方法を提供することにある。An object of the present invention is to provide an excellent method for producing fine-grained barium 7-elite for magnetic recording without the above-mentioned drawbacks, and in particular, to provide a method for producing fine-grained barium ferrite for high-density perpendicular magnetic recording by improving the hydrothermal synthesis method. It's about doing.
鉄及びバリウム等が六方晶系バリウムフェライトを生成
する組成で浴解し且つ該金属塩に対して水酸化アルカリ
を反応当量よりも３ ｍｏｌ／ｌ以上過剰に含有する溶
液を７０Ｃ以上に保持して攪拌した後、生成したスラリ
ーをオートクレープに装入して１３０〜２５０Ｃで処理
し、生成した沈殿物に低融点酸化物を混合した後、６０
０〜９００ｃで熱処理してバリウムフェライト超微粒子
企製造するというものである。A solution in which iron, barium, etc. are bath-dissolved with a composition that produces hexagonal barium ferrite, and which contains alkali hydroxide in excess of 3 mol/l or more than the reaction equivalent with respect to the metal salt, is maintained at a temperature of 70C or higher. After stirring, the generated slurry was charged into an autoclave and treated at 130 to 250C, and a low melting point oxide was mixed with the generated precipitate.
Barium ferrite ultrafine particles are manufactured by heat treatment at 0 to 900c.
本発明の方法において使用するＦｅ（１）及びＢａ（１
））は、各々公知の硫酸塩、硝酸塩、塩化物、水酸化物
等であり、水酸化アルカリとしては、水酸化ナトリウム
、水酸化カリウムが好ましい。Fe(1) and Ba(1) used in the method of the present invention
)) are known sulfates, nitrates, chlorides, hydroxides, etc., and the alkali hydroxide is preferably sodium hydroxide or potassium hydroxide.
低融点酸化物としては特定するものではないが、Ｂ２Ｏ
３、Ｐ２Ｏ５、Ｐｂ０％ ｖ２ｏ、、Ｂ１２Ｏ３等が好
ましい。Although not specified as a low melting point oxide, B2O
3, P2O5, Pb0% v2o, B12O3, etc. are preferred.
本発明法において、Ｆｅ（１）とＢ ａ （Ｉｔ）イオ
ンの混合比（Ｆｅ／Ｂａ）は６〜１２が好ましい。６未
満では非磁性のＢａＯが過剰に存在し、１２以上ではα
・Ｆｅ ０が混在してくる為である。In the method of the present invention, the mixing ratio (Fe/Ba) of Fe(1) and B a (It) ions is preferably 6 to 12. If it is less than 6, non-magnetic BaO exists in excess, and if it is more than 12, α
- This is because Fe 0 is mixed.
水酸化アルカリの過剰濃度を３ ｍｏｌ／ｌ以上とする
理由は、３ ｍｏｌ／ｌ未満では、生成するバリウムフ
ェライトの粒度が粗大となり好ましくない。The reason why the excessive concentration of alkali hydroxide is set to 3 mol/l or more is that if it is less than 3 mol/l, the particle size of the barium ferrite produced becomes coarse, which is not preferable.
尚、過剰濃度３ ｒｎｏｌ／ｌを超えても格別の効果は
得られないので３〜８ ｍｏｌ／ｌが好ましい。Incidentally, even if the excessive concentration exceeds 3 rnol/l, no particular effect can be obtained, so a range of 3 to 8 mol/l is preferable.
水酸化アルカリは、鉄及びバリウム等を溶解した水溶液
を７０ Ｃ以上に加温してから添加するか、室温で添加
した後、７０ Ｃ以上に加温するか、いずれの方法を採
っても良い。Alkali hydroxide may be added after heating an aqueous solution containing iron, barium, etc. to 70 C or higher, or added at room temperature and then heated to 70 C or higher. .
７０ Ｃ以上での攪拌保持時間は０．５〜３時間時間刃
充分である。The stirring holding time at 70 C or higher is sufficient for 0.5 to 3 hours.
次にオートクレープでの水熱処理温度は、１３０〜２５
０Ｃ，好ましくは１８０〜２３０Ｃの範囲とする。Next, the hydrothermal treatment temperature in the autoclave is 130 to 25
0C, preferably in the range of 180 to 230C.
この温度以下では反応速度が遅く生産性に欠け、六角板
状以外の結晶が混在したり、あるいはバリウムフェライ
ト相まで反応が進まない。２５０″Ｃ以上では粒子の成
長により目的とするバリウムフェライト超微粒子が得ら
れないからである。オートクレープによる水熱処理時間
は１〜１０時間程度で完了する。Below this temperature, the reaction rate is slow and productivity is lacking, crystals other than hexagonal plate shapes are mixed, or the reaction does not proceed to the barium ferrite phase. This is because if the temperature exceeds 250''C, the target barium ferrite ultrafine particles cannot be obtained due to particle growth.The hydrothermal treatment using an autoclave is completed in about 1 to 10 hours.
このようにして得られたバリウムフェライト粉は、Ｘ線
回折の同定によりバリウムフェライトな生成しているが
、飽和磁化値（以下σＢと記す）が小さい為、次工程の
熱処理によりσＳを向上させるが、熱処理する前に低融
点酸化物を添加する理由は、熱処理による粒子間焼結に
より、粒子が粗大化するのを防ぐためである。The barium ferrite powder thus obtained is identified as barium ferrite by X-ray diffraction, but since the saturation magnetization value (hereinafter referred to as σB) is small, the σS is improved by heat treatment in the next step. The reason why a low melting point oxide is added before heat treatment is to prevent particles from becoming coarse due to interparticle sintering caused by heat treatment.
添加量としては、バリウムフェライト粉に対して重量比
で１以上とする。これ以下では低融点酸化物の十分な効
果が得られない。The amount added is 1 or more in weight ratio to the barium ferrite powder. Below this range, the sufficient effect of the low melting point oxide cannot be obtained.
低融点酸化物を添加したバリウムフェライト粉の熱処理
は大気中６００〜９００Ｃの範囲とする。この温度以下
では５０ ｅｍｕ／ｇ以上の高０８値を有するバリウム
フェライトが得られず、９００Ｃを超える温度で行なう
と、急激な粒成長により粒子が粗大化する。The barium ferrite powder to which the low melting point oxide is added is heat treated in the air at a temperature of 600 to 900C. Below this temperature, barium ferrite having a high 08 value of 50 emu/g or more cannot be obtained, and if it is carried out at a temperature exceeding 900C, the particles become coarse due to rapid grain growth.
本発明によれば、高密度磁気記録用材料に望まれる特性
な有したバリウムフェライト超微粒子が効率良く得られ
る。尚、公知であるＡｌ、Ｔｉ、ＣＯｌＭｕ ｓ ｃｒ
ｓ Ｎｉ、Ｃｕｓ Ｚｎｓ Ｎｂｓ ５ｂＳＴａなど
の一種以上でＦｅの一部を置換し、保磁力を制御する方
法も適用可能なことは勿論である。According to the present invention, ultrafine barium ferrite particles having characteristics desired for high-density magnetic recording materials can be efficiently obtained. In addition, publicly known Al, Ti, COlMuscr
Of course, a method of controlling the coercive force by replacing a part of Fe with one or more types of Fe, such as sNi, CusZnsNbs, and 5bSTa, is also applicable.
以下実施例について説明する。 Examples will be described below.
実施例１
硝酸第二鉄０．４８ ｍｏｌ、水酸化バリウム０．０６
ｍｏｌ、硝酸コバルト及び四塩化チタンな各々０．０３
４９ ｍｏｌを水４７０ｍ１に溶解し、加温して７０Ｃ
に攪拌保持しながら、これに水酸化ナトリウム３８６ｇ
を４８ｗｔ％の水溶液とし、全量１）になるように添加
したところ茶褐色沈殿が生成した。Example 1 Ferric nitrate 0.48 mol, barium hydroxide 0.06
mol, cobalt nitrate and titanium tetrachloride each 0.03
Dissolve 49 mol in 470ml of water and heat to 70C.
While stirring, add 386 g of sodium hydroxide to this.
was made into a 48 wt % aqueous solution and added so that the total amount was 1), and a brown precipitate was formed.
この温度に３０分間保持した後、得られたスラリーの全
量をオートクレープに装入し、２３０Ｃで４時間水熱処
理を行ない、生成した沈殿を温水洗浄によりアルカリを
除去した後、弱酸で過剰のＢａを除去し、再び水洗した
。その後アルコール処理を行ない真空乾燥した。After maintaining this temperature for 30 minutes, the entire amount of the obtained slurry was charged into an autoclave and subjected to hydrothermal treatment at 230C for 4 hours. After washing the generated precipitate with hot water to remove alkali, excess Ba was was removed and washed again with water. Thereafter, it was treated with alcohol and dried in vacuum.
得られた乾燥粉末に重量比で１対２のＢ２Ｏ３を加えて
ボールミルで混合し、この混合物を磁製ルツボに入れ、
８１０Ｃで２時間加熱処理した後、放冷し次いで該粉末
を２．５重量％の酢酸水溶液で洗浄処理し、ＢＯを完全
に除去した後乾燥した。B2O3 in a weight ratio of 1:2 was added to the obtained dry powder, mixed in a ball mill, and this mixture was placed in a porcelain crucible.
After heat treatment at 810C for 2 hours, the powder was allowed to cool, and then the powder was washed with a 2.5% by weight acetic acid aqueous solution to completely remove BO, and then dried.
得られた生成物の粉末特性及び磁気特性結果を表１に示
す。Table 1 shows the powder properties and magnetic properties of the obtained product.
実施例２
硝酸第二鉄０．５ ｍｏｌ ％水酸化バリウム０．０６
ｍｏｌ 。Example 2 Ferric nitrate 0.5 mol% Barium hydroxide 0.06
mol.
硝酸コバルト及び四塩化チタンを各々０．０３４９ ｍ
ｏｔご水７１５ｍ１に溶解し、加温して８０Ｃに攪拌保
持しながら、これに水酸化ナトリウム２０６ｇを４８ｗ
ｔ％の水溶液とし、全量１ｔになるように添加したとこ
ろ茶褐色沈殿が生成した。0.0349 m each of cobalt nitrate and titanium tetrachloride
Dissolve in 715ml of water, heat and stir and maintain at 80C, add 48w of 206g of sodium hydroxide to this.
When the solution was made into an aqueous solution with a total concentration of 1 t, a brown precipitate was formed.
この温度に３０分間保持した後、得られたスラリーの全
量号オートクレープに装入し、１９０Ｃで７時間水熱処
理を行ない、生成した沈殿を温水洗浄によりアルカリを
除去した後、弱酸で過剰のＢａご除去し、再び水洗した
。その後アルコール処理を行ない真空乾燥した。After maintaining this temperature for 30 minutes, the entire amount of the slurry obtained was charged into a No. 1 autoclave, and hydrothermally treated at 190C for 7 hours. After washing the generated precipitate with hot water to remove alkali, excess Ba was It was removed and washed again with water. Thereafter, it was treated with alcohol and dried in vacuum.
得られた乾燥粉末に重量比で１対１のＢｉ Ｏを加えて
ボールミルで混合し、この混合物を磁性ルツボに入れ、
８４０Ｃで２時間加熱処理した後、放を
冷し次いで該粉梁４．５重量％の酢酸水溶液で洗浄し、
Ｂｉ Ｏを完全に除去した後乾燥した。得られた生成物
の粉末特性及び磁気特性結果を表１に示す０
比較例
低融点酸化物を使用しなかった以外は、実施例１と同様
に処理し、磁性粉末を得た。その結果表１に示すように
粒子が粗大化し微細粒子は得られなかった。BiO was added to the obtained dry powder in a weight ratio of 1:1, mixed in a ball mill, and this mixture was placed in a magnetic crucible.
After heat treatment at 840C for 2 hours, the powder was cooled and then washed with a 4.5% by weight acetic acid aqueous solution.
After completely removing Bi 2 O, it was dried. The results of the powder properties and magnetic properties of the obtained product are shown in Table 1. Comparative Example A magnetic powder was obtained in the same manner as in Example 1 except that the low melting point oxide was not used. As a result, as shown in Table 1, the particles became coarse and fine particles were not obtained.
表 １
〔発明の効果〕
本発明によれば、高密度磁気記録媒体用として好適な平
均粒径０．１μｍ以下で且つ高飽和磁化値を有する板状
バリウムフェライト粒子が効率良く得られる。Table 1 [Effects of the Invention] According to the present invention, plate-shaped barium ferrite particles having an average particle diameter of 0.1 μm or less and a high saturation magnetization value suitable for use in high-density magnetic recording media can be efficiently obtained.
Claims (1)
を生成する組成で溶解され且つ該金属塩に対して水酸ア
ルカリを反応当量よりも３ｍｏｌ／ｌ以上過剰に含有す
る溶液を７０℃以上に保持して攪拌し、生成したスラリ
ーをオートクレープに装入して、１３０〜２５０℃で処
理し、生成した沈殿物に低融点酸化物を混合した後、６
００〜９００℃で熱処理することを特徴とするバリウム
フェライト超微粒子の製造方法。(1) A solution in which iron, barium, etc. are dissolved in a composition that produces hexagonal barium ferrite, and which contains an alkali hydroxide in excess of 3 mol/l or more relative to the reaction equivalent of the metal salt, is maintained at 70°C or higher. The resulting slurry was charged into an autoclave and treated at 130 to 250°C, and a low melting point oxide was mixed with the resulting precipitate.
A method for producing ultrafine barium ferrite particles, characterized by heat treatment at 00 to 900°C.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61260352A JPS63114201A (en) | 1986-10-31 | 1986-10-31 | Manufacture of super-fine barium ferrite grain |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61260352A JPS63114201A (en) | 1986-10-31 | 1986-10-31 | Manufacture of super-fine barium ferrite grain |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS63114201A true JPS63114201A (en) | 1988-05-19 |
Family
ID=17346768
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61260352A Pending JPS63114201A (en) | 1986-10-31 | 1986-10-31 | Manufacture of super-fine barium ferrite grain |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63114201A (en) |
-
1986
- 1986-10-31 JP JP61260352A patent/JPS63114201A/en active Pending
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