JPH047083B2 - - Google Patents
Info
- Publication number
- JPH047083B2 JPH047083B2 JP57172203A JP17220382A JPH047083B2 JP H047083 B2 JPH047083 B2 JP H047083B2 JP 57172203 A JP57172203 A JP 57172203A JP 17220382 A JP17220382 A JP 17220382A JP H047083 B2 JPH047083 B2 JP H047083B2
- Authority
- JP
- Japan
- Prior art keywords
- acicular
- magnetic
- powder
- iron oxide
- inert gas
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 claims description 18
- 230000005291 magnetic effect Effects 0.000 claims description 14
- 229910052751 metal Inorganic materials 0.000 claims description 12
- 239000002184 metal Substances 0.000 claims description 12
- 239000006247 magnetic powder Substances 0.000 claims description 8
- 239000011261 inert gas Substances 0.000 claims description 7
- 239000000843 powder Substances 0.000 claims description 6
- 238000010438 heat treatment Methods 0.000 claims description 4
- 238000004519 manufacturing process Methods 0.000 claims description 4
- 238000003763 carbonization Methods 0.000 claims description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 11
- ZWEHNKRNPOVVGH-UHFFFAOYSA-N 2-Butanone Chemical compound CCC(C)=O ZWEHNKRNPOVVGH-UHFFFAOYSA-N 0.000 description 9
- 239000002245 particle Substances 0.000 description 9
- 238000000034 method Methods 0.000 description 7
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 6
- 239000000696 magnetic material Substances 0.000 description 6
- 230000005415 magnetization Effects 0.000 description 6
- 229910052742 iron Inorganic materials 0.000 description 5
- 229910052799 carbon Inorganic materials 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- 229910001566 austenite Inorganic materials 0.000 description 3
- 239000011248 coating agent Substances 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 229920002239 polyacrylonitrile Polymers 0.000 description 3
- 238000005245 sintering Methods 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- 125000004432 carbon atom Chemical group C* 0.000 description 2
- 230000005294 ferromagnetic effect Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- 239000007858 starting material Substances 0.000 description 2
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- 239000006087 Silane Coupling Agent Substances 0.000 description 1
- CUPCBVUMRUSXIU-UHFFFAOYSA-N [Fe].OOO Chemical compound [Fe].OOO CUPCBVUMRUSXIU-UHFFFAOYSA-N 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 150000001721 carbon Chemical class 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 229910002091 carbon monoxide Inorganic materials 0.000 description 1
- 238000010000 carbonizing Methods 0.000 description 1
- 229940090961 chromium dioxide Drugs 0.000 description 1
- IAQWMWUKBQPOIY-UHFFFAOYSA-N chromium(4+);oxygen(2-) Chemical compound [O-2].[O-2].[Cr+4] IAQWMWUKBQPOIY-UHFFFAOYSA-N 0.000 description 1
- AYTAKQFHWFYBMA-UHFFFAOYSA-N chromium(IV) oxide Inorganic materials O=[Cr]=O AYTAKQFHWFYBMA-UHFFFAOYSA-N 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 239000000543 intermediate Substances 0.000 description 1
- 229910021519 iron(III) oxide-hydroxide Inorganic materials 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 235000019353 potassium silicate Nutrition 0.000 description 1
- 229920002545 silicone oil Polymers 0.000 description 1
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 229910006540 α-FeOOH Inorganic materials 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
- H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
- H01F1/10—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials non-metallic substances, e.g. ferrites, e.g. [(Ba,Sr)O(Fe2O3)6] ferrites with hexagonal structure
- H01F1/11—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials non-metallic substances, e.g. ferrites, e.g. [(Ba,Sr)O(Fe2O3)6] ferrites with hexagonal structure in the form of particles
- H01F1/112—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials non-metallic substances, e.g. ferrites, e.g. [(Ba,Sr)O(Fe2O3)6] ferrites with hexagonal structure in the form of particles with a skin
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
- H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
- H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
- H01F1/06—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys in the form of particles, e.g. powder
- H01F1/065—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys in the form of particles, e.g. powder obtained by a reduction
Description
【発明の詳細な説明】
産業上の利用分野
本発明は高出力、高密度記録用磁気記録媒体の
磁性材料として用いて好適な磁気記録用金属磁性
粉末の製造方法に係る。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for producing metal magnetic powder for magnetic recording, which is suitable for use as a magnetic material for high-output, high-density recording magnetic recording media.
背景技術とその問題点
高出力及び高密度記録用の磁気記録媒体に用い
る磁性材料としては、飽和磁化σSが大きく且つ抗
磁力の高いものが要求されるが、従来広汎に用い
られているγ−Fe2O3、Fe3O4或いはこれらの中
間体、及び強磁性２酸化クロム（CrO2）は飽和
磁化σSが70〜90emu／ｇ程度で抗磁力Hcも250〜
600Oe程度である。Background Art and Problems Magnetic materials used in magnetic recording media for high output and high density recording are required to have a large saturation magnetization σ S and a high coercive force. - Fe 2 O 3 , Fe 3 O 4 or their intermediates, and ferromagnetic chromium dioxide (CrO 2 ) have a saturation magnetization σ S of about 70-90 emu/g and a coercive force Hc of 250-90 emu/g.
It is about 600Oe.
またCo含有酸化鉄粉末は、Coの添加量を調整
することにより抗磁力Hcを高めることは可能で
あるが、飽和磁化σSは60〜80emu／ｇ程度であ
り、いずれの場合も高出力、高密度用磁気記録媒
体を得るための磁性材料としては充分ではない。 In addition, with Co-containing iron oxide powder, it is possible to increase the coercive force Hc by adjusting the amount of Co added, but the saturation magnetization σ S is about 60 to 80 emu/g, and in any case, high output and It is not sufficient as a magnetic material for obtaining a high-density magnetic recording medium.
そこで飽和磁化が大きく高抗磁力を有する磁性
材料としてFe及びFeを主成分としCo、或いはNi
を含有した金属磁性粉末が開発されている。 Therefore, as a magnetic material with large saturation magnetization and high coercive force, Fe and Fe are the main components, and Co or Ni is used as a magnetic material.
Metal magnetic powder containing .
この種金属磁性粉末を得る方法としては湿式還
元法、乾式還元法、蒸発法等が知られている。 Wet reduction methods, dry reduction methods, evaporation methods, etc. are known as methods for obtaining this kind of metal magnetic powder.
乾式還元法としては、針状の磁性酸化鉄或いは
オキシ水酸化鉄を必要に応じてこれらにCo或い
はNi等の金属を添加して還元性ガス中で還元し、
針状の形骸を残すものである。この場合、実際に
は還元時のシンタリング等を防止するためにシリ
コンオイル、シランカツプリング剤、水ガラス等
で出発材料を被覆した後還元する方法が採られ
る。ところがこれらの材料は、これらを針状酸化
鉄の表面に全体的に均一に付着させることが困難
であり、また付着した材料の有機成分が磁性体中
に残存することなどによつて最終的に得られた針
状金属磁性微粉末において充分な磁気特性の向上
がみられないという欠点がある。 In the dry reduction method, acicular magnetic iron oxide or iron oxyhydroxide is reduced in a reducing gas by adding a metal such as Co or Ni to it as necessary.
It leaves needle-like remains. In this case, in practice, in order to prevent sintering and the like during reduction, a method is adopted in which the starting material is coated with silicone oil, a silane coupling agent, water glass, etc. and then reduced. However, it is difficult to uniformly adhere these materials to the entire surface of acicular iron oxide, and the organic components of the adhered materials may remain in the magnetic material, resulting in The resulting acicular metal magnetic fine powder has a drawback in that the magnetic properties are not sufficiently improved.
発明の目的
本発明は磁気特性の改善を図るようにした乾式
還元法に基く針状金属磁性粉末の製造方法を提供
するものである。OBJECTS OF THE INVENTION The present invention provides a method for producing acicular magnetic metal powder based on a dry reduction method in order to improve magnetic properties.
発明の概要
本発明は針状の酸化鉄または含水酸化鉄粉末の
表面に有機物の被覆を形成し、この被膜に炭化処
理を施した後還元して磁気記録用金属磁性粉末を
得るものである。Summary of the Invention The present invention involves forming an organic coating on the surface of acicular iron oxide or hydrated iron oxide powder, carbonizing the coating, and then reducing it to obtain a metal magnetic powder for magnetic recording.
実施例
すなわち本発明においては出発材料としての針
状粒子例えばα−FeOOH（αFe2O3）或いは同様
に針状のγ−Fe2O3の表面に有機物例えばポリア
クリルニトリルを均一に付着させた後、酸化性雰
囲気中で200〜400℃で酸化し、次いでこれを不活
性気体中または少量の酸素O2を含む不活性ガス
中で250℃〜600℃の５分間程度の熱処理による炭
化処理をなして針状粒子表面に炭素の被膜を析出
生成する。次いでこれを還元して目的とする針状
金属磁性粉末を得るものである。この場合、還元
ガスH2中にCO2を混入し粒子表面の炭素Ｃが次
の反応式、
CO2＋Ｃ→2CO ……(1)
によるCOを発生させ、これによつて酸化鉄を
3CO＋Fe2O3→2Fe＋3CO2 ……(2)
なる反応によつて還元することができる。そして
このようにして発生したCO2によつて更に(1)式の
反応を生ぜしめ(1)式と(2)式の反応の繰返し循環を
行わしめ得る。Example In other words, in the present invention, an organic substance such as polyacrylonitrile was uniformly adhered to the surface of acicular particles such as α-FeOOH (αFe 2 O 3 ) or similarly acicular γ-Fe 2 O 3 as a starting material. After that, it is oxidized at 200 to 400℃ in an oxidizing atmosphere, and then carbonized by heat treatment at 250℃ to 600℃ for about 5 minutes in an inert gas or an inert gas containing a small amount of oxygen O2 . A carbon film is deposited on the surface of the acicular particles. This is then reduced to obtain the desired acicular metal magnetic powder. In this case, CO 2 is mixed into the reducing gas H 2 and carbon C on the particle surface generates CO according to the following reaction formula, CO 2 + C → 2CO ... (1), thereby converting iron oxide into 3CO + Fe 2 It can be reduced by the reaction O 3 →2Fe+3CO 2 ……(2). The CO 2 generated in this manner further causes the reaction of formula (1), and the reactions of formulas (1) and (2) can be repeatedly circulated.
実施例 １
長軸0.3〜0.4μｍ、軸比８〜10の針状γ−Fe2O3
にポリアクリルニトリルを有機溶媒メチルエチル
ケトン（MEK）に溶解した溶液を加えて混合し
た後、MEKを蒸発させてポリアクリルニトリル
を針状γ−Fe2O3粒子の表面に均一に付着させ
る。次いでこれを適当なO2の存在下で熱処理し
た後不活性気体（N2）中300℃以上で焼成する。
このようにして炭素原子で表面を均一に被覆した
針状の酸化鉄粒子を得、これをよくほぐした状態
で加熱炉に入れCO2及び／またはH2ガスを流し
ながら300〜500℃で所定時間還元し、針状鉄粒子
を得る。これを空気中に取り出したときこれが燃
焼しないようにメタノール溶液中に浸漬しメタノ
ール溶液を徐々に蒸発されてこの針状鉄粒子の表
面に酸化被膜を形成した。Example 1 Acicular γ-Fe 2 O 3 with a long axis of 0.3 to 0.4 μm and an axial ratio of 8 to 10
A solution of polyacrylonitrile dissolved in the organic solvent methyl ethyl ketone (MEK) is added and mixed, and then MEK is evaporated to uniformly adhere polyacrylonitrile to the surface of the acicular γ-Fe 2 O 3 particles. This is then heat treated in the presence of an appropriate amount of O 2 and then fired at 300° C. or higher in an inert gas (N 2 ).
In this way, acicular iron oxide particles whose surfaces are uniformly coated with carbon atoms are obtained, and after being thoroughly loosened, they are placed in a heating furnace and heated to a predetermined temperature of 300 to 500°C while flowing CO 2 and/or H 2 gas. After time reduction, acicular iron particles are obtained. When taken out into the air, the iron particles were immersed in a methanol solution to prevent them from burning, and the methanol solution was gradually evaporated to form an oxide film on the surface of the needle iron particles.
このようにして得た針状鉄磁性粉末は電子顕微
鏡で観察したところその長さは0.2〜0.3μｍであ
り針状比は７〜８の針状微粒子として形成され、
その抗磁力Hcは1250Oe、磁化量σSは175emu／ｇ
であつた。 When the acicular ferromagnetic powder thus obtained was observed with an electron microscope, its length was 0.2 to 0.3 μm, and the acicular ratio was 7 to 8.
Its coercive force Hc is 1250 Oe, and magnetization σ S is 175 emu/g.
It was hot.
炭化処理は上述したように不活性ガス中若しく
は少量のO2を含む不活性ガス中で250℃〜600℃
以上での熱処理によつて行うことが望ましいが、
これは250℃未満では炭化処理に時間がかかりす
ぎ、また600℃を越える場合、針状粒子どうしの
シンタリング（焼結）の可能性が生じてくること
に因る。 As mentioned above, the carbonization treatment is carried out at 250℃ to 600℃ in an inert gas or an inert gas containing a small amount of O2 .
It is preferable to carry out the heat treatment as described above, but
This is because if the temperature is lower than 250°C, the carbonization process takes too much time, and if the temperature exceeds 600°C, there is a possibility of sintering of the acicular particles.
発明の効果
本発明製法によつて得た磁気記録用金属磁性粉
末は高抗磁力Hcと共に大きな飽和磁化σSを有す
るものであるが、これは金属磁性粉末表面に形成
するシンタリング防止の被膜において炭素原子が
生ずるようにして、この炭素が、１酸化炭素及び
２酸化炭素として気化して飛散消失することによ
つて最終的に金属磁性微粒子表面にはこの炭素の
非磁性被膜がほとんど残存しなくなることによる
ものと思われる。Effects of the Invention The metal magnetic powder for magnetic recording obtained by the manufacturing method of the present invention has a high coercive force Hc and a large saturation magnetization σS , but this is due to the fact that the anti-sintering coating formed on the surface of the metal magnetic powder As carbon atoms are generated, this carbon vaporizes as carbon monoxide and carbon dioxide and scatters and disappears, so that almost no non-magnetic film of carbon remains on the surface of the metal magnetic fine particles. This seems to be due to the following.
Claims (1)
有機物の被膜を形成し、該被膜に不活性ガス中も
しくは少量のO2を含む不活性ガス中で250℃〜
600℃以上での熱処理により、炭化処理を施した
後還元することを特徴とする磁気記録用針状金属
磁性粉末の製法。1. Form an organic film on the surface of acicular iron oxide or hydrated iron oxide powder, and heat the film at 250°C or higher in an inert gas or an inert gas containing a small amount of O2 .
A method for producing acicular metal magnetic powder for magnetic recording, which is characterized by carbonization treatment and reduction by heat treatment at 600°C or higher.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57172203A JPS5961903A (en) | 1982-09-30 | 1982-09-30 | Manufacture of acicular magnetic metal powder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57172203A JPS5961903A (en) | 1982-09-30 | 1982-09-30 | Manufacture of acicular magnetic metal powder |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5961903A JPS5961903A (en) | 1984-04-09 |
| JPH047083B2 true JPH047083B2 (en) | 1992-02-07 |
Family
ID=15937491
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP57172203A Granted JPS5961903A (en) | 1982-09-30 | 1982-09-30 | Manufacture of acicular magnetic metal powder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5961903A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6252904A (en) * | 1985-09-02 | 1987-03-07 | Showa Denko Kk | Manufacture of magnetic iron oxide powder |
| JPS6376305A (en) * | 1986-09-18 | 1988-04-06 | Taiyo Yuden Co Ltd | Magnetic powder for plastic magnet or rubber magnet and manufacture thereof |
| JP2007126755A (en) * | 2006-12-28 | 2007-05-24 | Toyo Tanso Kk | Carbon-coated metal particle and method for manufacturing the same |
-
1982
- 1982-09-30 JP JP57172203A patent/JPS5961903A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5961903A (en) | 1984-04-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JPH047083B2 (en) | ||
| JPS608605B2 (en) | Oxidation treatment method for metal magnetic powder for magnetic recording media | |
| US4369076A (en) | Process for producing magnetic metal powder | |
| JPS60255628A (en) | Fine powder of ba ferrite plate particle for magnetic recording use and its preparation | |
| JP3129414B2 (en) | Manufacturing method of acicular iron alloy magnetic particles for magnetic recording | |
| JPH04230004A (en) | Manufacture of magnetic recording needle ferroalloy magnetic particle powder | |
| JP3242102B2 (en) | Magnetic powder and method for producing the same | |
| JPH0143683B2 (en) | ||
| JPS6411577B2 (en) | ||
| JP2894495B2 (en) | Manufacturing method of metal magnetic powder for magnetic recording media | |
| JPH0469091B2 (en) | ||
| JP2827190B2 (en) | Method for producing acicular iron alloy magnetic particles for magnetic recording | |
| JPH03253505A (en) | Production of ferromagnetic metal powder | |
| JPS61216306A (en) | Magnetic metal powder and manufacture thereof | |
| JP3001830B2 (en) | Manufacturing method of metal magnetic powder for magnetic recording media | |
| JPH02205601A (en) | Ferromagnetic metal powder | |
| JP3171223B2 (en) | Method for producing acicular magnetic particle powder | |
| JPS6452002A (en) | Acicular magnetized metal fine powder having excellent dispersion and its production | |
| JPH0643601B2 (en) | Method for producing metallic iron particle powder or alloy magnetic particle powder mainly composed of iron | |
| JPS6012764B2 (en) | Manufacturing method of ferromagnetic powder | |
| JPH0618131B2 (en) | Method for producing magnetic powder for magnetic recording medium | |
| JPS6116024A (en) | Magnetic recording medium | |
| JPH04210403A (en) | Acicular alloy magnetic powder and magnetic recording medium using this | |
| JPS60166235A (en) | Preparation of gamma-iron oxide | |
| JPS6012763B2 (en) | Manufacturing method of ferromagnetic powder |