JPS63184306A - Stabilization of ferromagnetic metal powder - Google Patents
Stabilization of ferromagnetic metal powderInfo
- Publication number
- JPS63184306A JPS63184306A JP62198252A JP19825287A JPS63184306A JP S63184306 A JPS63184306 A JP S63184306A JP 62198252 A JP62198252 A JP 62198252A JP 19825287 A JP19825287 A JP 19825287A JP S63184306 A JPS63184306 A JP S63184306A
- Authority
- JP
- Japan
- Prior art keywords
- metal powder
- ferromagnetic metal
- compound
- heat treatment
- powder
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 229910052751 metal Inorganic materials 0.000 title claims abstract description 102
- 239000002184 metal Substances 0.000 title claims abstract description 102
- 239000000843 powder Substances 0.000 title claims abstract description 92
- 230000005294 ferromagnetic effect Effects 0.000 title claims abstract description 72
- 230000006641 stabilisation Effects 0.000 title 1
- 238000011105 stabilization Methods 0.000 title 1
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims abstract description 42
- -1 alkoxide compound Chemical class 0.000 claims abstract description 33
- 150000001875 compounds Chemical class 0.000 claims abstract description 19
- 238000010438 heat treatment Methods 0.000 claims abstract description 19
- 239000012298 atmosphere Substances 0.000 claims abstract description 16
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims abstract description 15
- 239000007789 gas Substances 0.000 claims abstract description 13
- 239000001257 hydrogen Substances 0.000 claims abstract description 12
- 229910052739 hydrogen Inorganic materials 0.000 claims abstract description 12
- 239000003960 organic solvent Substances 0.000 claims abstract description 12
- 238000000034 method Methods 0.000 claims description 56
- 230000005291 magnetic effect Effects 0.000 claims description 26
- 239000011261 inert gas Substances 0.000 claims description 3
- 230000000087 stabilizing effect Effects 0.000 claims description 3
- 150000002739 metals Chemical class 0.000 claims 1
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 abstract description 45
- 238000000151 deposition Methods 0.000 abstract description 12
- IMNFDUFMRHMDMM-UHFFFAOYSA-N N-Heptane Chemical compound CCCCCCC IMNFDUFMRHMDMM-UHFFFAOYSA-N 0.000 abstract description 6
- 239000002923 metal particle Substances 0.000 abstract description 6
- 230000001376 precipitating effect Effects 0.000 abstract description 3
- VOITXYVAKOUIBA-UHFFFAOYSA-N triethylaluminium Chemical compound CC[Al](CC)CC VOITXYVAKOUIBA-UHFFFAOYSA-N 0.000 abstract 1
- JLTRXTDYQLMHGR-UHFFFAOYSA-N trimethylaluminium Chemical compound C[Al](C)C JLTRXTDYQLMHGR-UHFFFAOYSA-N 0.000 abstract 1
- 230000000694 effects Effects 0.000 description 17
- 230000006866 deterioration Effects 0.000 description 16
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 11
- 239000010419 fine particle Substances 0.000 description 10
- 239000010410 layer Substances 0.000 description 10
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 9
- 230000005415 magnetization Effects 0.000 description 8
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 7
- 230000003647 oxidation Effects 0.000 description 7
- 238000007254 oxidation reaction Methods 0.000 description 7
- 239000002904 solvent Substances 0.000 description 7
- 230000000052 comparative effect Effects 0.000 description 6
- 239000002245 particle Substances 0.000 description 6
- 239000011347 resin Substances 0.000 description 6
- 229920005989 resin Polymers 0.000 description 6
- 150000004703 alkoxides Chemical class 0.000 description 5
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 5
- 239000000463 material Substances 0.000 description 5
- 239000001301 oxygen Substances 0.000 description 5
- 229910052760 oxygen Inorganic materials 0.000 description 5
- 239000002344 surface layer Substances 0.000 description 5
- 229910052782 aluminium Inorganic materials 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 4
- 230000007062 hydrolysis Effects 0.000 description 4
- 238000006460 hydrolysis reaction Methods 0.000 description 4
- 229910052742 iron Inorganic materials 0.000 description 4
- 229910000000 metal hydroxide Inorganic materials 0.000 description 4
- 150000004692 metal hydroxides Chemical class 0.000 description 4
- 125000000956 methoxy group Chemical group [H]C([H])([H])O* 0.000 description 4
- 239000002798 polar solvent Substances 0.000 description 4
- 239000002244 precipitate Substances 0.000 description 4
- 239000011241 protective layer Substances 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 3
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 description 3
- 239000003795 chemical substances by application Substances 0.000 description 3
- 229910001873 dinitrogen Inorganic materials 0.000 description 3
- 230000007774 longterm Effects 0.000 description 3
- 239000000696 magnetic material Substances 0.000 description 3
- VLKZOEOYAKHREP-UHFFFAOYSA-N n-Hexane Chemical compound CCCCCC VLKZOEOYAKHREP-UHFFFAOYSA-N 0.000 description 3
- 238000006722 reduction reaction Methods 0.000 description 3
- 239000002002 slurry Substances 0.000 description 3
- 239000004094 surface-active agent Substances 0.000 description 3
- 238000005979 thermal decomposition reaction Methods 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 2
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 2
- 238000007605 air drying Methods 0.000 description 2
- 125000000217 alkyl group Chemical group 0.000 description 2
- 150000001412 amines Chemical class 0.000 description 2
- 239000011230 binding agent Substances 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- DIOQZVSQGTUSAI-UHFFFAOYSA-N decane Chemical compound CCCCCCCCCC DIOQZVSQGTUSAI-UHFFFAOYSA-N 0.000 description 2
- 238000005137 deposition process Methods 0.000 description 2
- 238000001704 evaporation Methods 0.000 description 2
- 239000001307 helium Substances 0.000 description 2
- 229910052734 helium Inorganic materials 0.000 description 2
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 2
- 150000002431 hydrogen Chemical class 0.000 description 2
- 230000003301 hydrolyzing effect Effects 0.000 description 2
- 229910001872 inorganic gas Inorganic materials 0.000 description 2
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 2
- 239000006247 magnetic powder Substances 0.000 description 2
- 150000002736 metal compounds Chemical class 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 239000002480 mineral oil Substances 0.000 description 2
- 235000010446 mineral oil Nutrition 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- BKIMMITUMNQMOS-UHFFFAOYSA-N nonane Chemical compound CCCCCCCCC BKIMMITUMNQMOS-UHFFFAOYSA-N 0.000 description 2
- 239000011368 organic material Substances 0.000 description 2
- 229920001296 polysiloxane Polymers 0.000 description 2
- 230000003449 preventive effect Effects 0.000 description 2
- RSJKGSCJYJTIGS-UHFFFAOYSA-N undecane Chemical compound CCCCCCCCCCC RSJKGSCJYJTIGS-UHFFFAOYSA-N 0.000 description 2
- DKPFZGUDAPQIHT-UHFFFAOYSA-N Butyl acetate Natural products CCCCOC(C)=O DKPFZGUDAPQIHT-UHFFFAOYSA-N 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 241000195493 Cryptophyta Species 0.000 description 1
- OTMSDBZUPAUEDD-UHFFFAOYSA-N Ethane Chemical compound CC OTMSDBZUPAUEDD-UHFFFAOYSA-N 0.000 description 1
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical compound CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- 150000001338 aliphatic hydrocarbons Chemical class 0.000 description 1
- 125000003545 alkoxy group Chemical group 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 150000004945 aromatic hydrocarbons Chemical class 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 125000004432 carbon atom Chemical group C* 0.000 description 1
- 238000010531 catalytic reduction reaction Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- FUZZWVXGSFPDMH-UHFFFAOYSA-N hexanoic acid Chemical compound CCCCCC(O)=O FUZZWVXGSFPDMH-UHFFFAOYSA-N 0.000 description 1
- 150000004679 hydroxides Chemical class 0.000 description 1
- 229910017053 inorganic salt Inorganic materials 0.000 description 1
- 150000002576 ketones Chemical class 0.000 description 1
- 238000004898 kneading Methods 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 239000006249 magnetic particle Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000012299 nitrogen atmosphere Substances 0.000 description 1
- TVMXDCGIABBOFY-UHFFFAOYSA-N octane Chemical compound CCCCCCCC TVMXDCGIABBOFY-UHFFFAOYSA-N 0.000 description 1
- 239000012044 organic layer Substances 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 239000012071 phase Substances 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 239000011164 primary particle Substances 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- OGHBATFHNDZKSO-UHFFFAOYSA-N propan-2-olate Chemical compound CC(C)[O-] OGHBATFHNDZKSO-UHFFFAOYSA-N 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000005204 segregation Methods 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 239000000344 soap Substances 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 239000008096 xylene Substances 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
- H01F1/04—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
- H01F1/061—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 with a protective layer
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
本発明は、高密度記録に適した磁気記録媒体に於ける磁
性素材としての強磁性金属粉微粒子の製造方法に関する
。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for producing fine ferromagnetic metal powder particles as a magnetic material in a magnetic recording medium suitable for high-density recording.
従来技術
磁気記録用磁性素材については、広い記録波長域での高
出力・低ノイズを計る為に、均一性の高い微細形状粒子
で、高い保磁力（Ｈｅ）を有し、飽和磁化（σＳ）・残
留磁化（σｒ）共に大きく、かつ角形比（Ｒｓ＝σｒ／
σＳ）も可及的に大きい磁気特性が基本的に要求される
。このうち、磁性素材としての磁性粉については、強磁
性金属粉が、その優れた磁気特性から、まずオーディオ
用磁気テープの素材として実用化され、又、８闘ビデオ
用素材として実用化されている。鉄を主要成分とした針
状性金属粉微粒子の場合、Ｈｃ値及びσＳ値の充分な高
さに基づく優れた磁気的ポテンシャリティが利用されて
いる事となる訳であるが、通常は１μｍ以下の微粒子で
ある事から、空気に対する酸化活性が極めて強く、磁気
記録媒体としての適用性を確保し、かつ信顧性を付与せ
しめる為の安定性が重要な物性として位置づけられてい
る。Conventional magnetic materials for magnetic recording have highly uniform fine-shaped particles, high coercive force (He), and saturation magnetization (σS) in order to achieve high output and low noise in a wide recording wavelength range.・Both residual magnetization (σr) is large and the squareness ratio (Rs=σr/
σS) is also basically required to have as large a magnetic property as possible. Of these, regarding magnetic powder as a magnetic material, ferromagnetic metal powder was first put to practical use as a material for audio magnetic tapes due to its excellent magnetic properties, and was also put into practical use as a material for 8-fight videos. . In the case of acicular metal powder particles containing iron as the main component, excellent magnetic potential based on sufficiently high Hc and σS values is utilized, but usually magnetic particles with a diameter of 1 μm or less are utilized. Since they are fine particles, they have extremely strong oxidizing activity against air, and stability is considered an important physical property to ensure applicability as a magnetic recording medium and to provide credibility.
従来この種の安定性を確保する手段として、（１）微粒
子表層部に酸化層を設ける方法、（２）微粒子表面に特
殊な保護層を被膜形成させる方法、
（３）微粒子表層部に酸化層を設けた後加熱処理を加え
ることにより酸化被膜層の緻密化をはかる方法等が提案
されている。Conventionally, methods for ensuring this kind of stability include (1) a method of forming an oxide layer on the surface layer of the fine particles, (2) a method of forming a special protective layer on the surface of the fine particles, and (3) a method of forming an oxide layer on the surface layer of the fine particles. A method has been proposed in which the oxide film layer is densified by applying heat treatment after providing the oxide film.
（１）に属する方法としては、酸化層を気相接触反応で
行なう方法、及び液相反応で行なう方法等があり、例え
ば特開昭５５−１２５２０５．５６−６９３０１．５６
−１２７７０１ 、５２−８５０５４ 、５５−１６４
００１ 、５７−８５９０１ 、５７−９３５０４．５
８−１１０４３３、５８−１５９３０等が挙げられる。Methods belonging to (1) include a method in which the oxidation layer is formed by a gas phase contact reaction and a method in which the oxidation layer is formed by a liquid phase reaction.
-127701, 52-85054, 55-164
001, 57-85901, 57-93504.5
Examples include 8-110433 and 58-15930.
更に（２）に属する方法としては、有機物の保護層を被
着する方法としてシリコーンに代表される特殊な界面活
性剤的性格の強い低分子量有機物を被着する方法、例え
ば特開昭４６−５０５７．５０−１０４１６４．５１−
１２２６５５ 、５１−１４０８６０ 、５２−１５５
３９８ 、５３−５７９８ 、５３−７６９５８、５４
−２４０００ 、５５−３９６６０ 、５５−３９６６
１ 、５５−３９６６２ 、５６−２９８４１．５６−
５４０１３．５６−１４８７２６等が挙げられる。Furthermore, as a method belonging to (2), a method of depositing a protective layer of an organic material is a method of depositing a low molecular weight organic material with strong surfactant properties, typified by silicone, such as JP-A-46-5057. .50-104164.51-
122655, 51-140860, 52-155
398, 53-5798, 53-76958, 54
-24000, 55-39660, 55-3966
1, 55-39662, 56-29841.56-
54013.56-148726 and the like.
また更に樹脂類の保護層を被着する方法として、特開昭
５３−１３９０６．５３−７８０９９．５４−１３９５
０８．５６−１３０８３１等がある。また無機塩を被着
する方法として、特開昭５３−８７９８．５６−９８４
０１．５７−９８０２．５７−６３６０１．５８−１５
９３０６．５８−１５９３０７．５８−１５９３０８．
５８−１６１７０８．５１３−１６１７０９゜５８−１
６１７２５等が挙げられる。Furthermore, as a method for applying a protective layer of resin, JP-A-53-13906.53-78099.54-1395
08.56-130831 etc. In addition, as a method of depositing inorganic salt, Japanese Patent Application Laid-Open No. 53-8798.56-984
01.57-9802.57-63601.58-15
9306.58-159307.58-159308.
58-161708.513-161709゜58-1
61725 and the like.
また気化性防錆剤を使用する方法として、特公昭６０−
４５６５に開示の方法が挙げられ、またアミン、鉱物油
を保護層の形成に使用する方法として、特開昭５３−７
８０９６．５３．７８０９や本発明者等が提案した、特
願昭６０−２９２８７５等が挙げられる。In addition, as a method of using a volatile rust preventive agent,
4565, and a method using amine and mineral oil to form a protective layer is disclosed in JP-A No. 53-7.
8096.53.7809 and Japanese Patent Application No. 60-292875 proposed by the present inventors.
さらに無機ガスを利用する方法として本発明者等が提案
した、特願昭６０−２９２８７等が挙げられる。Further, as a method of utilizing an inorganic gas, there is a method proposed by the present inventors, such as Japanese Patent Application No. 60-29287.
（３）に属する方法としては本発明者等が提案した特願
昭５９−２７３７１１が挙げられる。A method belonging to (3) includes Japanese Patent Application No. 59-273711 proposed by the present inventors.
本 日が解決しようとする問題点
強磁性金属粉微粒子の表面に、前記の方法により安定性
に付与することが行なわれてきたわけであるが、（１）
の方法として挙げられる、強磁性金属粉微粒子表層部に
金属粉自身の酸化物を設ける方法では、酸化物層を持た
ない金属粉に比較して安定性は高いが、これだけでは充
分な酸化防止効果を持つことが出来なかった。又（２）
の方法例えばシリコーンに代表される特殊な低分子量の
界面活性剤等を被着する方法は、劣化の原因となる酸素
及び水分を存機層により遮断する事を特徴とするもので
あり、強磁性金属微粒子の劣化を防止する効果は、上記
の酸化被膜だけに比較して著しく向上するし、又同様な
一例として樹脂等を被着する方法が挙げられる。しかし
ながら、低分子量の界面活性剤及び樹脂等は、酸素及び
水藻気の分子に比較して大きい為に、比較的多量に使用
する必要性があった。又、磁気記録媒体として使用する
場合、強磁性金属粉末は、常にバインダー樹脂と混合し
て使用する。この場合、上記の方法同様にバインダー樹
脂に強磁性金属粉末が覆われる訳であり、この様な有機
物及び樹脂処理の効果は低減して仕舞うのである。The problem that we are trying to solve today Stability has been imparted to the surface of ferromagnetic metal powder particles by the method described above, but (1)
The method of providing the metal powder's own oxide on the surface layer of the ferromagnetic metal powder fine particles is more stable than metal powder without an oxide layer, but this method alone is not sufficient to prevent oxidation. I couldn't have it. Also (2)
For example, the method of depositing a special low-molecular-weight surfactant, such as silicone, is characterized by blocking oxygen and moisture, which cause deterioration, with an organic layer. The effect of preventing the deterioration of metal fine particles is significantly improved compared to the above-mentioned oxide film alone, and a similar example is a method in which a resin or the like is applied. However, since low molecular weight surfactants, resins, etc. are larger than molecules of oxygen and water algae, it is necessary to use them in relatively large amounts. Furthermore, when used as a magnetic recording medium, ferromagnetic metal powder is always mixed with a binder resin. In this case, as in the above method, the ferromagnetic metal powder is covered with the binder resin, and the effects of such organic substance and resin treatment are reduced.
また無機塩を被着する方法として、金属石鹸及び金属ア
ルコキシド及び金属水酸化物を被着する方法等が挙げら
れるが、この場合は、前記の有機物より分子量は小さく
酸素、水蒸気等の劣化原因となる分子を比較的透過せし
めずらいのではあるが、強磁性金属微粒子との結合力が
弱い為に安定性を向上する効果はやはり低いものでしか
ない。In addition, methods of depositing inorganic salts include methods of depositing metal soaps, metal alkoxides, and metal hydroxides, but in this case, the molecular weight is smaller than the organic substances mentioned above, and oxygen, water vapor, etc. are the cause of deterioration. Although it is relatively difficult for other molecules to pass through, the effect of improving stability is still low because the bonding force with the ferromagnetic metal fine particles is weak.
また特開昭５８−１２０７０４記載の方法として、強磁
性金属粉末に対して不活性でかつ金属アルコキシドを溶
解しうる溶媒に金属アルコキシドを溶解し、得られた溶
液を用いて強磁性金属粉末を湿潤し、次いで該金属粉末
の表面またはその附近に存在する金属アルコキシドを徐
々に加水分解することにより、該金属アルコキシドの完
全または不完全加水分解物の被膜を該金属粉末の表面に
形成し、次いで溶媒を蒸散またほろ別する強磁性金属粉
末の安定化方法が提案されている。この方法においては
、強磁性金属粉末表面に金属水和物の被膜が形成される
わけであるが、かかる方法では、後記比較例３に示すよ
うに、金属水和物の被膜が強磁性粉末との結合力を持た
ない為に安定性を向上する効果は少なかった。また、強
磁性金属表面にＨ＋：＋４１＋ａ、ｚｎ＋ｚ等の水酸化
物を存機極性溶媒に溶解し被着する方法も特開昭６１−
４０００５に提案されているように公知である。この方
法は、金属水酸化物を有機極性溶媒に熔解し、極性溶媒
を蒸発して該金属水酸化物を析出しめて被着するのであ
るが、かかる方法では、溶媒乾燥時に偏析が避けられな
いことと、有機極性溶媒蒸発後析出残留した金属水酸化
物と強磁性金属とは強い結合力を持たない為に酸化安定
性を向上する被膜としての効果は少なかった。In addition, as a method described in JP-A-58-120704, a metal alkoxide is dissolved in a solvent that is inert to ferromagnetic metal powder and can dissolve the metal alkoxide, and the resulting solution is used to wet the ferromagnetic metal powder. Then, by gradually hydrolyzing the metal alkoxide present on or near the surface of the metal powder, a film of complete or incomplete hydrolysis of the metal alkoxide is formed on the surface of the metal powder, and then a solvent is added to the metal powder. A method has been proposed for stabilizing ferromagnetic metal powder by evaporating or breaking it down. In this method, a metal hydrate film is formed on the surface of the ferromagnetic metal powder. Since it does not have the binding force of , the effect of improving stability was small. Additionally, a method of dissolving hydroxides such as H+:+41+a, zn+z, etc. in a polar solvent and depositing them on the surface of a ferromagnetic metal is also disclosed in JP-A-61-
40005 is known. In this method, the metal hydroxide is dissolved in an organic polar solvent, and the polar solvent is evaporated to precipitate and deposit the metal hydroxide. However, with this method, segregation is inevitable when the solvent dries. However, since the metal hydroxide that precipitated and remained after evaporation of the organic polar solvent and the ferromagnetic metal did not have a strong bonding force, the film had little effect on improving oxidation stability.
また気化性防錆剤を使用する方法は、前記の有機物の利
用と同様に基本的な安定性向上とはならない。またアミ
ン、鉱物油を使用する方法に於いても前記の有機物の利
用と同様に基本的な安定性向上とはならない。また、無
機ガスを利用する方法としてＳＯ□は結合力は強いので
あるが、水蒸気による酸化に対しての安定性付与に難点
があり、ＣＯ２は、酸化速度を低下せしめる効果はある
が、結合力が弱い為に酸素及び水蒸気と置換し易く、や
はり安定性確保に難点があった。Furthermore, the method of using a volatile rust preventive agent does not fundamentally improve stability, similar to the use of organic substances described above. Also, in the method of using amine or mineral oil, the basic stability cannot be improved like the above-mentioned use of organic substances. In addition, as a method of using inorganic gases, SO□ has a strong bonding force, but it has the disadvantage of providing stability against oxidation by water vapor, and CO2 has the effect of reducing the oxidation rate, but has a strong bonding force. Since it is weak, it is easily replaced by oxygen and water vapor, which again poses a problem in ensuring stability.
（３）の方法として微粒子表層部に酸化層を設けた後加
熱処理を加えて酸化被膜層の緻密化をはかる方法は、微
粒子表層部が緻密な酸化被膜となる為に有効な手段であ
るが、強磁性金属の酸化物被膜はこれを緻密化したとし
てもそれ自身だけではまだ完全に酸素及び水蒸気による
腐食を防止することは出来なかった。As method (3), the method of forming an oxide layer on the surface layer of the fine particles and then applying heat treatment to make the oxide layer denser is an effective method for forming a dense oxide layer on the surface layer of the fine particles. Even if the ferromagnetic metal oxide film was made denser, it was still not able to completely prevent corrosion by oxygen and water vapor by itself.
なお、その他、還元前にＡｌ化合物を被着し強磁性金属
粉末を製造する特公昭５６−２８９６７記載の方法が知
られている。この場合は、還元以前に被着する為に水素
等の還元性ガスにより金属表面に被膜としてのＡｌ化合
物は、必然的に均一には存在出来ず、安定性を向上する
効果は劣っていた。In addition, a method described in Japanese Patent Publication No. 56-28967 is known in which a ferromagnetic metal powder is produced by depositing an Al compound before reduction. In this case, since the Al compound is deposited before reduction, the Al compound cannot uniformly exist as a film on the metal surface due to the reducing gas such as hydrogen, and the effect of improving stability is poor.
問題点を解決する為の手段
本発明者等は上記の問題点の解決を図る為に、鋭意検討
を加えた結果、強磁性金属粉末をＡ１アルコキシド化合
物又は／及びＡｌアルキル化合物を溶解した有機溶媒中
へ浸漬し、メタノールを添加して該強磁性金属粉末にＡ
ｌ化合物を析出被着せしめ、その後不活性ガス雰囲気下
で又は水素ガス若しくは水素を主体とする還元性ガス雰
囲気下で熱処理する事により極めて安定性の高い強磁性
金属粉末が得られることを見い出し本発明に到達した。Means for Solving the Problems In order to solve the above-mentioned problems, the inventors of the present invention have made intensive studies and found that the ferromagnetic metal powder is mixed with an organic solvent in which an A1 alkoxide compound or/and an Al alkyl compound is dissolved. and add methanol to the ferromagnetic metal powder.
It was discovered that an extremely stable ferromagnetic metal powder can be obtained by precipitating and depositing a ferromagnetic metal compound and then heat-treating it in an inert gas atmosphere or in an atmosphere of hydrogen gas or a reducing gas mainly composed of hydrogen. invention has been achieved.
以下、本発明を説明する。The present invention will be explained below.
本発明に於いて、使用出来るＡｌアルコキシド化合物又
はＡｌアルキル化合物としては、トルエン。In the present invention, the Al alkoxide compound or Al alkyl compound that can be used is toluene.
ヘプタン等の強磁性金属粒子と結合しにくくまたメタノ
ールを溶解する一般的な有機溶媒に易溶解性のものであ
ればいかなるものでも使用可能である。例えば、Ａｌア
ルコキシド化合物としては、Ａｌ（ＯＣｚＨｓ）＋、Ａ
ｌ（ｉｓｏ−ＯＣＪ、）ｉ、 Ａｌ（ｓｅｅ−ＯＣＪ、
）ｓ等が利用出来、また、Ａｌアルキル化合物としては
、Ａｌ（ＣＨ３）１．Ａｌ（ＣＪｓ）ｓ、Ａｌ（ＣＪｖ
）３．Ａｌ（ＣＪ、）３等が利用出来るものとして挙げ
られる。ただし、より高次の炭素原子数を有するアルコ
キシド化合物若しくはアルキル化合物であっても、かか
る溶媒に実質的に溶解するものである限り、使用可能で
あることば勿論である。Any material can be used as long as it is difficult to bond with ferromagnetic metal particles such as heptane and is easily soluble in common organic solvents that dissolve methanol. For example, Al alkoxide compounds include Al(OCzHs)+, A
l(iso-OCJ,)i, Al(see-OCJ,
)s etc. can be used, and as the Al alkyl compound, Al(CH3)1. Al(CJs)s, Al(CJv
)3. Examples of materials that can be used include Al(CJ, )3. However, it goes without saying that an alkoxide compound or alkyl compound having a higher number of carbon atoms can also be used as long as it is substantially soluble in the solvent.
本発明はかかるＡｌアルコキシド化合物若しくはＡｌア
ルキル化合物に由来するＡｌ化合物を溶液中で強磁性金
属粉末に被着した後、特定の条件で熱処理するものであ
るが、以下、強磁性金属粉末として最も一般的な、鉄を
主体とする強磁性金属化合物を出発原料とし水素又は水
素を主体とする還元性ガスとの接触還元反応によって得
られた磁気記録用強磁性金属粉末（長軸の平均粒径２〜
０．０５μｍ好ましくは１〜０．１μｍ程度 、長軸／
短軸比５〜２０好ましくは１０〜１５程度）を例として
被着方法及び熱処理方法を示す。In the present invention, an Al compound derived from such an Al alkoxide compound or an Al alkyl compound is applied to a ferromagnetic metal powder in a solution, and then heat-treated under specific conditions. A ferromagnetic metal powder for magnetic recording obtained by a catalytic reduction reaction of a ferromagnetic metal compound mainly composed of iron as a starting material with hydrogen or a reducing gas mainly composed of hydrogen (average particle size on the long axis 2 ~
0.05 μm, preferably about 1 to 0.1 μm, long axis/
The adhesion method and heat treatment method will be described by taking as an example a case where the short axis ratio is about 5 to 20, preferably about 10 to 15.
本発明で使用しうる溶媒としては、例えば、ベンゼン、
トルエン、キシレンのごとき芳香族炭化水素類；ヘキサ
ン、ヘプタン、オクタン、ノナン、デカン、ウンデカン
のごとき脂肪族炭化水素類；アセトン、ＭＥＫ 、 Ｍ
ＩＢＫのごときケトン類；エタノール、イソプロパツー
ルのごときアルコール類；酢酸エチル、酢酸ブチルのご
ときエステル類等が好ましいものとして挙げられる。Examples of solvents that can be used in the present invention include benzene,
Aromatic hydrocarbons such as toluene and xylene; aliphatic hydrocarbons such as hexane, heptane, octane, nonane, decane, and undecane; acetone, MEK, M
Preferred examples include ketones such as IBK; alcohols such as ethanol and isopropanol; and esters such as ethyl acetate and butyl acetate.
まず、Ａｌアルコキシド化合物又は／及びＡｌアルキル
化合物をこれらの有機溶媒、例えばトルエン等の有機溶
媒に溶解し、上記の如き強磁性金属粉末をこの溶液に浸
漬する。First, an Al alkoxide compound or/and an Al alkyl compound are dissolved in an organic solvent such as toluene, and the above-mentioned ferromagnetic metal powder is immersed in this solution.
強磁性金属粉末は、還元直後の徐酸化されていないもの
でも良いし、又公知の手段で徐酸化して表面に酸化層を
設けたものでも良い。該強磁性金属粉末の溶液浸漬物を
好ましくはスラリー状又はペースト状で混合し金属粉末
とＡ１アルコキシド化合物等を溶解した溶液を充分接触
させる。この際念のため粉末を浸漬したまま数分から数
１０時間程度放置してもよい。しかる後、該溶解してい
るＡｌアルコキシド化合物若しくはＡｌアルキル化合物
をある種のＡｔ化合物として析出セしめうるような析出
剤、例えばメタノールを系に添加し、該強磁性金属粉末
に該Ａｔ化合物を析出被着せしめるのである。析出被着
を出来るだけ完全ならしめるため、数分から数時間程度
ニーダ−等により混合するのが望ましい。また、温度は
特に制限は無いが、室温〜６０゛Ｃ程度が操作上好まし
い。なお、アルミニウムの被着量は、八ｌ／Ｆｅ＝０．
０５χ〜２０χ、好ましくは０．１χ〜１０χ（ＷｔＸ
）程度である。また、メタノールの添加量は、化学量
論的に少なくともモル比で３倍量以上程度が好ましく、
上限は特に制限はないが、１０倍量以上加えることは効
果の点からいっても実質的な意味が無い。The ferromagnetic metal powder may be one that has not been slowly oxidized immediately after reduction, or may be one that has been slowly oxidized by known means to provide an oxidized layer on the surface. The ferromagnetic metal powder soaked in the solution is preferably mixed in the form of a slurry or paste, and the metal powder is brought into sufficient contact with the solution in which the A1 alkoxide compound and the like are dissolved. At this time, as a precaution, the powder may be left immersed for several minutes to several tens of hours. Thereafter, a precipitating agent such as methanol that can precipitate the dissolved Al alkoxide compound or Al alkyl compound as a certain At compound is added to the system, and the At compound is precipitated onto the ferromagnetic metal powder. It covers it. In order to make the precipitation adhesion as complete as possible, it is desirable to mix with a kneader or the like for several minutes to several hours. Further, the temperature is not particularly limited, but it is preferably from room temperature to about 60°C for operational reasons. The amount of aluminum deposited is 8l/Fe=0.
05χ~20χ, preferably 0.1χ~10χ (WtX
). Further, the amount of methanol added is preferably at least 3 times or more in terms of stoichiometric molar ratio,
Although there is no particular upper limit, adding more than 10 times the amount has no practical meaning in terms of effectiveness.
さらに、取扱の便宜上、該スラリーを濾過した後、また
はそのまま、窒素中又は空気中で乾燥を行いＡｌｌ化合
物こより析出被着処理された強磁性金属粉末とする。Further, for convenience of handling, the slurry is filtered or dried in nitrogen or air to obtain a ferromagnetic metal powder which has been subjected to a deposition treatment with an All compound.
なお、実際に本発明を実施する場合、スラリー状若しく
はペースト状で処理す操作を行うための混合機としては
、スラリー状で処理する場合はディシルバー又はホモジ
ナイザー等が好適に利用出来、又ペースト状で処理する
場合はニーダ−等が好適に利用出来る。In addition, when actually carrying out the present invention, a disilver or homogenizer can be suitably used as a mixer for processing slurry or paste. When processing with a kneader or the like, a kneader or the like can be suitably used.
斯くして得られたＡｔ化合物を析出被着せしめた該強磁
性金属粉末を熱処理するのであるが、熱処理方法として
は、本発明者等が特願昭５９−２７３７１１において提
案した、窒素やヘリウム、メタン、アルゴン等の鉄に対
して不活性なガス雰囲気下で熱処理を加える方法により
行う事が好ましい。又その他、水素又は水素を主体とし
た還元性ガス雰囲気下に於いて熱処理する事によっても
同様の効果を奏することが出来る。該熱処理の温度とし
ては２００℃〜７０００℃の温度範囲が好ましい。２０
０°Ｃ未満では、熱分解が実質的に進行しないためか、
熱処理の効果が充分奏されず、又、７００°Ｃを越える
と、磁気記録用利用される強磁性金属粉末は、前記した
ごとく通常１μｍ以下の微粒子である為に焼結が過剰に
進行し、磁気記録用としては、不適当な金属粉末となる
。処理時間は温度によって変わりうるが、３０分〜１０
時間程度である。The ferromagnetic metal powder on which the At compound is precipitated and deposited is heat-treated.The heat treatment method is performed using nitrogen, helium, helium, It is preferable to carry out heat treatment in an atmosphere of a gas inert to iron, such as methane or argon. In addition, the same effect can be achieved by heat treatment in an atmosphere of hydrogen or a reducing gas mainly composed of hydrogen. The temperature of the heat treatment is preferably in the range of 200°C to 7000°C. 20
This may be because thermal decomposition does not substantially proceed below 0°C.
If the heat treatment is not sufficiently effective and the temperature exceeds 700°C, sintering will proceed excessively because the ferromagnetic metal powder used for magnetic recording is usually fine particles of 1 μm or less as described above. The resulting metal powder is unsuitable for magnetic recording. The processing time may vary depending on the temperature, but it takes between 30 minutes and 10 minutes.
It takes about an hour.
発明の作用効果
本発明の作用につき詳細に説明する。本発明は、強磁性
金属粉末をへ１アルコキシド化合物又は／及びＡｌアル
キル化合物を溶解した有機溶媒中へ浸漬し、メタノール
を添加して該強磁性金属粉末にｌ化合物を析出被着せし
め、その後不活性ガス雰囲気下で又は水素ガス若しくは
水素を主体とする還元性ガス雰囲気下で熱処理する事を
特徴とするものであるが、Ａ１アルコキシド化合物又は
へ１アルキル化合物は単に有機溶媒中に溶解した状態で
は、強磁性金属粉末を浸漬しても、該粉末に対し特に強
い結合性は示さない。Effects of the Invention The effects of the present invention will be explained in detail. In the present invention, a ferromagnetic metal powder is immersed in an organic solvent in which an alkoxide compound or/and an Al alkyl compound is dissolved, methanol is added to precipitate and deposit a compound on the ferromagnetic metal powder, and then an aluminum compound is deposited on the ferromagnetic metal powder. It is characterized by heat treatment under an active gas atmosphere or under a hydrogen gas or a reducing gas atmosphere mainly consisting of hydrogen, but the A1 alkoxide compound or the he1 alkyl compound is not simply dissolved in an organic solvent. , even when ferromagnetic metal powder is immersed, it does not exhibit particularly strong binding to the powder.
しかして、前記したごとく、水を添加し力Ｕ水分解反応
を行い金属水和物を析出し強磁性粉末表面に該金属水和
物を堆積させ被膜を形成する方法が知られているが、ト
ルエン等の強磁性金属粉末に不活性な有機溶媒では、水
の溶解炭は非常に低い為に、またＡ１アルコキシド化合
物又はＡｌアルキル化合物の加水分解速度が非常に速い
為に、溶媒中で部分的、局部的に加水分解が進行して仕
舞い、均質な被膜を粉末表面に形成することは極めて困
難なのである。As mentioned above, a method is known in which water is added and a water decomposition reaction is carried out to precipitate a metal hydrate, and the metal hydrate is deposited on the surface of a ferromagnetic powder to form a film. In organic solvents such as toluene that are inert to ferromagnetic metal powders, the amount of dissolved carbon in water is very low, and the rate of hydrolysis of Al alkoxide compounds or Al alkyl compounds is very fast. However, hydrolysis progresses locally and ends, making it extremely difficult to form a homogeneous film on the powder surface.
しかるに、本発明においては、トルエン等の有機溶媒に
溶解するメタノールを添加する事により、アルコキシ基
とメトキシ基の交換反応、若しくは、アルキル基とノド
キシ基の交換反応が起り、恐らくは、Ａｌ （ＯＣＨ３
） ３が生成するとともに、該Ａｌ （ＯＣＩｈ） ：
＋はトルエン等の有機溶媒中よりゆっくりと析出し、強
磁性金属粒子表面に均一に付着すると推察されるのであ
る。けだし、ｇｌ Ａ ｌ化合物は、均一な溶液中から
析出するのであるから、必然的に、該溶液と接触してい
る金属粒子表面にまんべんなく析出し均一な皮膜を形成
するのである。However, in the present invention, by adding methanol that is dissolved in an organic solvent such as toluene, an exchange reaction between an alkoxy group and a methoxy group or an exchange reaction between an alkyl group and a nodoxy group occurs, and perhaps Al (OCH3
) 3 is generated, and the Al (OCIh):
It is inferred that + precipitates more slowly than in an organic solvent such as toluene and adheres uniformly to the surface of the ferromagnetic metal particles. However, since the gl A l compound precipitates from a uniform solution, it inevitably precipitates evenly and forms a uniform film on the surface of the metal particles that are in contact with the solution.
しかして、本発明においては、該Ａ１化合物の均−な皮
膜を有する金属粒子に対し、更に熱処理を加える事によ
り、該皮膜を構成するＡｌ化合物の熱分解、恐らくはＡ
ｌ （ＯＣＨ３） ３のＡｌ酸化物への熱分解が進行し
、Ａｌ （ＯＣＨ３） ３からなる皮膜は、より強固か
つ緻密な、Ａｌ酸化物からなる皮膜へと変化するのであ
る。斯くして、該皮膜が、強磁性金属粒子の酸化に対す
る安定性をさらに飛躍的に向上せしめる作用効果を奏す
ることになるのである。Therefore, in the present invention, by further applying heat treatment to the metal particles having a uniform film of the A1 compound, thermal decomposition of the Al compound constituting the film, and possibly A
Thermal decomposition of l (OCH3) 3 into Al oxide progresses, and the film made of Al (OCH3) 3 changes into a stronger and denser film made of Al oxide. In this way, the coating has the effect of further dramatically improving the stability of the ferromagnetic metal particles against oxidation.
災施開
以下実施例比較例により更に詳細に本発明の方法及び効
果を説明する。DESCRIPTION OF THE PREFERRED EMBODIMENTS The method and effects of the present invention will be explained in more detail with reference to Examples and Comparative Examples.
実施例１
一次粒子の長袖の平均粒径０．１５μｍ軸比１０の鉄を
主体とした強磁性金属粉末を１００ｇ用意した。Example 1 100 g of a ferromagnetic metal powder mainly composed of iron having a long-sleeved primary particle average particle size of 0.15 μm and an axial ratio of 10 was prepared.
振動試料型磁力計（ＶＳＭ）により外部磁場１０ｋＯｅ
で磁気特性を測定したところ、Ｈｃ＝１３８００ｅ、
σＳ−５−１６８ｅ／ｇ、 Ｒｓ＝０．４９３であ
った。Ａｌ （ｉｓｏ−ＯＣＪｑ） ＊２２．７ｇをト
ルエン１５０ｇに溶解した。該金属粉末を上記溶媒に浸
漬し念の為−晩装置した。Ａｌ／Ｆｅ＝３／１００Ｗｔ
比である。メタノールを１０．６８ｇ（３倍モル）添加
した後、ニーダ−により４時間混練を行い充分被着せし
めた。ひきつづいて空気中で風乾処理した。磁気特性を
測定したところＨｃ＝ １４８００ｅ。An external magnetic field of 10 kOe was applied using a vibrating sample magnetometer (VSM).
When the magnetic properties were measured, Hc=13800e,
σS-5-168e/g, Rs=0.493. 22.7 g of Al (iso-OCJq) * was dissolved in 150 g of toluene. The metal powder was immersed in the above solvent and kept overnight for precaution. Al/Fe=3/100Wt
It is a ratio. After adding 10.68 g (3 times the mole) of methanol, kneading was carried out for 4 hours using a kneader to ensure sufficient adhesion. This was followed by air-drying in the air. When the magnetic properties were measured, Hc=14800e.
ａ ｓ＝１３６ｅｍｕ／ｇ、 Ｒｓ＝０．５０１であっ
た。該処理金属粉末を特願昭５９−２７３７１１記載の
方法により窒素ガス雰囲気下で４００°Ｃ，２時間熱処
理を加えた。該熱処理金属粉末の磁気特性を測定したと
ころｔｔｃ＝１５４００ｅ、σｓ＝１３４ｅｍｕ／ｇ、
Ｒｓ＝０．５０２であった。８亥熱処理金属粉末をト
ルエンに浸漬し更に風乾を行った。その後、該処理金属
粉末を、５０’Ｃ，８０χＲＨの恒温恒湿器に放置して
、劣化試験を行った。６０時間経過後、該処理金属粉末
を恒温恒温器から取り出し磁気特性を測定したところ、
飽和磁化（σＳ）は、１２２８ｍｕ／ｇであった。また
−週間経過後、該処理した金属粉末の飽和磁化（σＳ）
を測定したところ、１２１ｅｍｕ／ｇであった。この結
果、磁気記録用金属磁性粉末として充分な安定性を持つ
事が分かった。a s = 136 emu/g, Rs = 0.501. The treated metal powder was heat treated at 400 DEG C. for 2 hours in a nitrogen gas atmosphere according to the method described in Japanese Patent Application No. 59-273711. When the magnetic properties of the heat-treated metal powder were measured, ttc = 15400e, σs = 134emu/g,
Rs=0.502. The heat-treated metal powder was immersed in toluene for 8 hours and then air-dried. Thereafter, the treated metal powder was left in a constant temperature and humidity chamber at 50'C and 80χRH to conduct a deterioration test. After 60 hours, the treated metal powder was taken out of the thermostat and its magnetic properties were measured.
The saturation magnetization (σS) was 1228 mu/g. Also, after a week has passed, the saturation magnetization (σS) of the treated metal powder
When measured, it was 121 emu/g. As a result, it was found that the powder had sufficient stability as a metal magnetic powder for magnetic recording.
実施例２ 実施例１と同様の強磁性金属粉末を使用した。Example 2 The same ferromagnetic metal powder as in Example 1 was used.
Ａｌ （ｉｓｏ−ＯＣ３Ｈｔ） ３をトルエン中に溶解
し、メタノールを添加し、強磁性金属粉末にＡｌ化合物
を被着処理する迄は実施例１と同様の方法で行なった。The same method as in Example 1 was followed except that Al (iso-OC3Ht) 3 was dissolved in toluene, methanol was added, and the Al compound was deposited on the ferromagnetic metal powder.
該処理金属粉末を水素雰囲気下で４００°Ｃ１２時間熱
処理を加えた。該処理金属粉末の磁気特性を測定したと
ころ、Ｈｃ＝１３７００ｅ、 σｓ＝１６０ｅｍｕ／
ｇ、Ｒｓ＝０．４９０であった。該処理金属粉末をトル
エンに浸漬後風乾した粉体として空気中に取り出した。The treated metal powder was heat treated at 400° C. for 12 hours in a hydrogen atmosphere. When the magnetic properties of the treated metal powder were measured, Hc=13700e, σs=160emu/
g, Rs=0.490. The treated metal powder was immersed in toluene and then taken out into the air as an air-dried powder.
・該金属粉末の磁気特性を測定したところＨｃ・１４４
５０ｅ、 ａ ｓ＝１３９ｅｍｕ／ｇ、 Ｒｓ＝０．
５００であった。実施例１と同様の方法で劣化試験を行
った。６０時間経過後該金属粉末のσＳ値は１２０ｅｍ
ｕ／ｇであった。また−週間経過後のσＳ値は同様に１
２０ｅｍｕ／ｇであった。この結果、水素雰囲気下での
熱処理によっても安定性を増加する効果がある事が分か
った。・Measurement of the magnetic properties of the metal powder revealed Hc・144
50e, a s=139emu/g, Rs=0.
It was 500. A deterioration test was conducted in the same manner as in Example 1. After 60 hours, the σS value of the metal powder is 120em
It was u/g. Similarly, the σS value after − weeks is 1
It was 20 emu/g. As a result, it was found that heat treatment in a hydrogen atmosphere also has the effect of increasing stability.
実施例３ 実施例１記載の強磁性金属粉末を使用した。Example 3 The ferromagnetic metal powder described in Example 1 was used.
Ａｌ（ｉｓｏ−ＣＪｔ） ３をＡｌ（ＣＪｓ）３ とし
た以外は実施例１と同様の方法で行った。Ａｌ（ＣｚＨ
５）＊の添加量はＡｌと強磁性金属との重量比で３／１
００とした。メタノール添加と同時にエタンガスが発生
した。被着処理後実施例１記載の方法により、熱処理を
加えた。該熱処理金属粉末の磁気特性を測定したところ
、Ｈｃ＝１５４００ｅ、 ａ ｓ＝１３４ｅｍｕ／ｇ、
Ｒｓ＝０．５０２であった。更にトルエンに浸漬後、風
乾処理を行なった後、実施例１記載の方法により劣化試
験を行なった。６０時間後の飽和磁化値は１２１ｅｍｕ
／ｇであった。The same method as in Example 1 was conducted except that Al(iso-CJs)3 was used instead of Al(iso-CJt)3. Al(CzH
5) The amount of * added is 3/1 in weight ratio of Al and ferromagnetic metal.
It was set as 00. Ethane gas was generated simultaneously with the addition of methanol. After the adhesion treatment, heat treatment was applied by the method described in Example 1. When the magnetic properties of the heat-treated metal powder were measured, Hc=15400e, a s=134emu/g,
Rs=0.502. Further, after being immersed in toluene and air-drying, a deterioration test was conducted using the method described in Example 1. The saturation magnetization value after 60 hours is 121 emu
/g.
また−週間経過後の飽和磁化値は、１２０ｅｍｕ／ｇで
あった。この結果Ａｌアルキル化合物を使用しても安定
性を増す効果を発揮することが確認された。Further, the saturation magnetization value after -week had passed was 120 emu/g. As a result, it was confirmed that even when an Al alkyl compound is used, the effect of increasing stability is exhibited.
実施例４ 実施例１記載の強磁性金属粉末を使用した。Example 4 The ferromagnetic metal powder described in Example 1 was used.
Ａｌ （ｉｓｏ−ＱＣ３）１＋） ｚの量を変化し更に
Ａｌ（ｉｓｏ−Ｃｄ５）ｓの量に応じて添加するメタノ
ールの量を変化した以外は、実施例１の方法で被着処理
した。窒素雰囲気下で４００°Ｃ１２時間熱処理した金
属粉末の実施例１と同様にして測定した劣化試験結果を
第１図に示す。なお、図において、○は６０時間後、Δ
は１週間後の値を示す。The deposition process was carried out in the same manner as in Example 1, except that the amount of Al(iso-QC3)1+)z was changed and the amount of methanol added was changed depending on the amount of Al(iso-Cd5)s. FIG. 1 shows the results of a deterioration test conducted in the same manner as in Example 1 for metal powder heat-treated at 400° C. for 12 hours in a nitrogen atmosphere. In addition, in the figure, ○ means after 60 hours, Δ
indicates the value after one week.
比較例１
実施例１記載の強磁性金属粉末をトルエンに浸漬し風乾
を行い強磁性金属粉末とした。該金属粉末の磁気特性を
測定した結果、Ｈｃ＝１５０００ｅ、 σｓ２１３Ｌ
ｅｍｕ／ｇ、 Ｒｓ＝０．５０２であった。実施例１と
同様の方法で劣化試験を行った。６０時間経過後のσＳ
値は９５ｅｍｕ／ｇであった。また−週間経過後のσＳ
値は９０ｅｍｕ／ｇであった。実施例に記載の方法によ
って得られた強磁性金属粉末より安定性が著しく劣る結
果であった。Comparative Example 1 The ferromagnetic metal powder described in Example 1 was immersed in toluene and air-dried to obtain a ferromagnetic metal powder. As a result of measuring the magnetic properties of the metal powder, Hc=15000e, σs213L
emu/g, Rs=0.502. A deterioration test was conducted in the same manner as in Example 1. σS after 60 hours
The value was 95 emu/g. Also - σS after a week has passed
The value was 90 emu/g. The stability was significantly inferior to that of the ferromagnetic metal powder obtained by the method described in the Examples.
比較例２ 実施例１記載の強磁性金属粉末を使用した。Comparative example 2 The ferromagnetic metal powder described in Example 1 was used.
Ａｌ（ｉｓｏ〜０ＣＪ７）３をトルエンに溶解し、強磁
性金属粉末を浸漬処理する迄は、実施例１と同様の方法
で被着処理した。該浸漬物をそのまま空気中で風乾処理
し強磁性金属粉末とした。該金属粉末の磁気特性を測定
した結果、Ｈｃ＝１４９５０ｅ、 σｓ＝１３２ｅｍ
ｕ／ｇ、 Ｒｓ＝０．５０２であった。該処理金属粉末
を実施例１記載の方法により劣化試験を行なった。６０
時間後の飽和磁化値は、９８ ｅｍｕ／ｇであった。ま
た−週間経過後の飽和磁化値は、９Ｑｅｍｕ／ｇであっ
た。この結果、被着処理により劣化初期の安定性を向上
する効果はわずかにあるもののが、到底充分な安定性付
与効果を発揮することは出来なかった。The deposition process was carried out in the same manner as in Example 1, except that Al(iso~0CJ7)3 was dissolved in toluene and the ferromagnetic metal powder was immersed. The soaked material was air-dried as it was in the air to obtain ferromagnetic metal powder. As a result of measuring the magnetic properties of the metal powder, Hc=14950e, σs=132em
u/g, Rs=0.502. The treated metal powder was subjected to a deterioration test using the method described in Example 1. 60
The saturation magnetization value after hours was 98 emu/g. Moreover, the saturation magnetization value after -week had passed was 9 Qemu/g. As a result, although the adhesion treatment had a slight effect of improving stability at the initial stage of deterioration, it was not possible to exhibit a sufficient stability imparting effect.
比較例３ 実施例１記載の強磁性金属粉末を使用した。Comparative example 3 The ferromagnetic metal powder described in Example 1 was used.
Ａｌ （ｉｓｏ−ＯＣ３Ｈ７） ３２２．７ｇをトルエ
ン１５０ｇに？容解した。該強磁性金属粉末を上記の溶
媒に浸漬し一晩放置した（Ａｌ／Ｆｅ・３／１００ ｗ
ｔ比）。該浸漬物に純水を６．０ｇ （イソプロポキシ
ドの３倍モル景）添加し加水分解した後、ニーダ−によ
り４時間混練を行い空気中で風乾処理した。これの磁気
特性を測定したところＨｃ＝１４８５０ｅ、 σ５＝
１３５ ｅｍｕ／ｇ、Ｒｓ＝０．５０１であった。該処
理金属粉末を実施例１記戦の方法により劣化試験を行っ
た。６０時間経過後のσＳ値は、１０６ ｅｍｕ／ｇで
あり、また−週間経過後のσＳ値は、９５ ｅｍｕ／ｇ
であった。この結果、単に加水分解を行い、へ１水
和物を強磁性金属粉末表面に堆積する方法では、初期の
劣化速度を低下する作用はある程度有するものの長期の
劣化に対しては存効な手段とはならないことが確認され
た。その為に磁気記録用強磁性金属粉末としては到底満
足できない結果となった。Al (iso-OC3H7) 322.7g to toluene 150g? I understand. The ferromagnetic metal powder was immersed in the above solvent and left overnight (Al/Fe・3/100 w
t ratio). After adding 6.0 g of pure water (3 times the molar mass of isopropoxide) to the soaked product and hydrolyzing it, the mixture was kneaded for 4 hours using a kneader and air-dried in the air. When we measured the magnetic properties of this, Hc=14850e, σ5=
135 emu/g, Rs=0.501. The treated metal powder was subjected to a deterioration test using the method described in Example 1. The σS value after 60 hours was 106 emu/g, and the σS value after − weeks was 95 emu/g.
Met. As a result, although the method of simply performing hydrolysis and depositing hemohydrate on the surface of ferromagnetic metal powder has the effect of reducing the initial deterioration rate to some extent, it is not an effective means of preventing long-term deterioration. It was confirmed that this is not the case. Therefore, the result was completely unsatisfactory as a ferromagnetic metal powder for magnetic recording.
実施例５、比較例４
実施例１記載の強磁性金属粉末を使用した。窒素ガスに
よる熱処理温度を変化した以外は、実施例１の方法で行
った。処理後の強磁性金属粉末の劣化試験結果を第２図
に示す。図において、○は６０時間後、Δは１週間後の
値を示す。この結果、熱処理温度が２００ ’Ｃ未満の
場合、初期の劣化防止に対してはある程度の効果を発揮
するものの時間と共に劣化が進行する為に、長期の安定
性に難点があることが判明した。したがって、長期安定
性を考慮した場合、実用的な観点から採用しろる熱処理
温度としては、２００°Ｃ以上が効果を発揮することが
解った。Example 5, Comparative Example 4 The ferromagnetic metal powder described in Example 1 was used. The method of Example 1 was followed except that the heat treatment temperature with nitrogen gas was changed. Figure 2 shows the results of a deterioration test on the ferromagnetic metal powder after treatment. In the figure, ○ indicates the value after 60 hours, and Δ indicates the value after 1 week. As a result, it was found that when the heat treatment temperature is less than 200'C, although it is effective to some extent in preventing initial deterioration, the deterioration progresses over time, resulting in problems in long-term stability. Therefore, when considering long-term stability, it was found that a heat treatment temperature of 200°C or higher is effective from a practical standpoint.
以上、実施例、比較例の記載から明らかな様に本発明に
従えば、強磁性金属粉末をＡ１アルコキシド化合物又は
／及びＡｌアルキル化合物を溶解した有機溶媒中へ浸漬
し、メタノールを添加して該強磁性金属粉末上にＡｌ化
合物を析出被着せしめ、均一な被膜を形成し、その後不
活性ガス雰囲気下で又は水素ガス若しくは水素を主体と
する還元性ガス雰囲気下で熱処理し、該被膜をより強固
・緻密な被膜にすることにより、結局、安定性の極めて
高い磁気記録用強磁性金属粉末を提供する事が出来るの
である。As is clear from the descriptions of Examples and Comparative Examples above, according to the present invention, ferromagnetic metal powder is immersed in an organic solvent in which an A1 alkoxide compound or/and an Al alkyl compound is dissolved, and methanol is added to dissolve the ferromagnetic metal powder. An Al compound is precipitated and deposited on ferromagnetic metal powder to form a uniform film, and then heat-treated in an inert gas atmosphere or hydrogen gas or a reducing gas atmosphere mainly composed of hydrogen to further improve the film. By creating a strong and dense coating, it is possible to provide extremely stable ferromagnetic metal powder for magnetic recording.
第１図は、Ａｌ化合物の被着量に対する強磁性金属粉末
の安定性を示すグラフであり、第２図は、耐化合物被着
強磁性金属粉末を窒素ガス雰囲気下で熱処理した場合の
処理温度に対する安定性の関係を示すグラフである。
なお、図において、Ｏは６０時間後、△は１週間後の値
を示す。Figure 1 is a graph showing the stability of ferromagnetic metal powder with respect to the amount of Al compound deposited, and Figure 2 is a graph showing the treatment temperature when the compound-resistant ferromagnetic metal powder is heat-treated in a nitrogen gas atmosphere. It is a graph showing the relationship of stability to. In the figure, O indicates the value after 60 hours, and Δ indicates the value after one week.
Claims (2)
及びＡｌアルキル化合物を溶解した有機溶媒中へ浸漬し
、メタノールを添加して該強磁性金属粉末にＡｌ化合物
を析出被着せしめ、その後不活性ガス雰囲気下で又は水
素ガス若しくは水素を主体とする還元性ガス雰囲気下で
熱処理する事を特徴とする強磁性金属の安定化方法。(1) Ferromagnetic metal powder with Al alkoxide compound or/
The ferromagnetic metal powder is immersed in an organic solvent in which an Al alkyl compound is dissolved, and methanol is added to precipitate and adhere the Al compound to the ferromagnetic metal powder, followed by reduction in an inert gas atmosphere or using hydrogen gas or hydrogen as the main component. A method for stabilizing ferromagnetic metals characterized by heat treatment in a magnetic gas atmosphere.
特許請求の範囲第１項記載の強磁性金属粉末の安定化方
法。(2) The method for stabilizing ferromagnetic metal powder according to claim 1, wherein the temperature range of the heat treatment is 200°C to 7000°C.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22211886 | 1986-09-22 | ||
| JP61-222118 | 1986-09-22 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS63184306A true JPS63184306A (en) | 1988-07-29 |
Family
ID=16777437
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62198252A Pending JPS63184306A (en) | 1986-09-22 | 1987-08-10 | Stabilization of ferromagnetic metal powder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63184306A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5711783A (en) * | 1994-02-15 | 1998-01-27 | H.C. Starck, Gmbh & Co., Kg | Preparation from metal alkoxides of high purity metal powder |
-
1987
- 1987-08-10 JP JP62198252A patent/JPS63184306A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5711783A (en) * | 1994-02-15 | 1998-01-27 | H.C. Starck, Gmbh & Co., Kg | Preparation from metal alkoxides of high purity metal powder |
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