JPH01294810A - Production of magnetic metal powder for magnetic recording - Google Patents
Production of magnetic metal powder for magnetic recordingInfo
- Publication number
- JPH01294810A JPH01294810A JP63123306A JP12330688A JPH01294810A JP H01294810 A JPH01294810 A JP H01294810A JP 63123306 A JP63123306 A JP 63123306A JP 12330688 A JP12330688 A JP 12330688A JP H01294810 A JPH01294810 A JP H01294810A
- Authority
- JP
- Japan
- Prior art keywords
- iron oxide
- acicular iron
- powder
- metal magnetic
- magnetic 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.)
- Granted
Links
- 229910052751 metal Inorganic materials 0.000 title claims abstract description 60
- 239000002184 metal Substances 0.000 title claims abstract description 60
- 239000000843 powder Substances 0.000 title claims abstract description 28
- 238000004519 manufacturing process Methods 0.000 title claims description 8
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 claims abstract description 80
- 239000002245 particle Substances 0.000 claims abstract description 34
- 230000009467 reduction Effects 0.000 claims abstract description 26
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 20
- 238000007254 oxidation reaction Methods 0.000 claims abstract description 18
- 230000003647 oxidation Effects 0.000 claims abstract description 13
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 9
- 239000001301 oxygen Substances 0.000 claims abstract description 9
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 claims abstract description 8
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 8
- 238000011282 treatment Methods 0.000 claims abstract description 8
- 229910052725 zinc Inorganic materials 0.000 claims abstract description 7
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 4
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 4
- 239000006247 magnetic powder Substances 0.000 claims description 45
- 238000000034 method Methods 0.000 claims description 40
- 239000007789 gas Substances 0.000 claims description 29
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 24
- 239000002994 raw material Substances 0.000 claims description 8
- 230000000087 stabilizing effect Effects 0.000 claims description 6
- 238000010301 surface-oxidation reaction Methods 0.000 claims description 5
- 239000000463 material Substances 0.000 claims description 4
- 239000011261 inert gas Substances 0.000 claims description 3
- 229910052709 silver Inorganic materials 0.000 claims description 2
- 238000010438 heat treatment Methods 0.000 abstract description 6
- 239000007858 starting material Substances 0.000 abstract description 6
- 230000032683 aging Effects 0.000 abstract 1
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 42
- 235000013980 iron oxide Nutrition 0.000 description 28
- -1 aluminum ions Chemical class 0.000 description 16
- WNROFYMDJYEPJX-UHFFFAOYSA-K aluminium hydroxide Chemical compound [OH-].[OH-].[OH-].[Al+3] WNROFYMDJYEPJX-UHFFFAOYSA-K 0.000 description 15
- 239000000243 solution Substances 0.000 description 15
- 239000000084 colloidal system Substances 0.000 description 13
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 11
- 239000007864 aqueous solution Substances 0.000 description 9
- 239000000203 mixture Substances 0.000 description 9
- 239000003960 organic solvent Substances 0.000 description 9
- 239000011734 sodium Substances 0.000 description 8
- 239000006249 magnetic particle Substances 0.000 description 7
- 239000002002 slurry Substances 0.000 description 7
- 230000000052 comparative effect Effects 0.000 description 6
- 239000000047 product Substances 0.000 description 6
- 238000000576 coating method Methods 0.000 description 5
- SZVJSHCCFOBDDC-UHFFFAOYSA-N ferrosoferric oxide Chemical compound O=[Fe]O[Fe]O[Fe]=O SZVJSHCCFOBDDC-UHFFFAOYSA-N 0.000 description 5
- 230000001590 oxidative effect Effects 0.000 description 5
- 238000005245 sintering Methods 0.000 description 5
- 239000011248 coating agent Substances 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 238000000635 electron micrograph Methods 0.000 description 4
- 238000010304 firing Methods 0.000 description 4
- 229910052742 iron Inorganic materials 0.000 description 4
- 150000002739 metals Chemical class 0.000 description 4
- 230000006641 stabilisation Effects 0.000 description 4
- 238000011105 stabilization Methods 0.000 description 4
- 238000005406 washing Methods 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- ANBBXQWFNXMHLD-UHFFFAOYSA-N aluminum;sodium;oxygen(2-) Chemical compound [O-2].[O-2].[Na+].[Al+3] ANBBXQWFNXMHLD-UHFFFAOYSA-N 0.000 description 3
- 238000007664 blowing Methods 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 239000003795 chemical substances by application Substances 0.000 description 3
- 230000003247 decreasing effect Effects 0.000 description 3
- 238000002474 experimental method Methods 0.000 description 3
- 230000004927 fusion Effects 0.000 description 3
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical compound [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 description 3
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 3
- 239000012071 phase Substances 0.000 description 3
- 238000012545 processing Methods 0.000 description 3
- 150000003839 salts Chemical class 0.000 description 3
- 229910001388 sodium aluminate Inorganic materials 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 2
- 229910002588 FeOOH Inorganic materials 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 239000003513 alkali Substances 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 2
- 230000003197 catalytic effect Effects 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 150000004679 hydroxides Chemical class 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 229910000358 iron sulfate Inorganic materials 0.000 description 2
- VBMVTYDPPZVILR-UHFFFAOYSA-N iron(2+);oxygen(2-) Chemical class [O-2].[Fe+2] VBMVTYDPPZVILR-UHFFFAOYSA-N 0.000 description 2
- 238000006386 neutralization reaction Methods 0.000 description 2
- 230000003472 neutralizing effect Effects 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- 238000004381 surface treatment Methods 0.000 description 2
- 229910052726 zirconium Inorganic materials 0.000 description 2
- 235000010582 Pisum sativum Nutrition 0.000 description 1
- 240000004713 Pisum sativum Species 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 102220502023 Ubiquitin-like modifier-activating enzyme 1_H25N_mutation Human genes 0.000 description 1
- CUPCBVUMRUSXIU-UHFFFAOYSA-N [Fe].OOO Chemical compound [Fe].OOO CUPCBVUMRUSXIU-UHFFFAOYSA-N 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 238000004220 aggregation Methods 0.000 description 1
- DIZPMCHEQGEION-UHFFFAOYSA-H aluminium sulfate (anhydrous) Chemical compound [Al+3].[Al+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O DIZPMCHEQGEION-UHFFFAOYSA-H 0.000 description 1
- BFNBIHQBYMNNAN-UHFFFAOYSA-N ammonium sulfate Chemical compound N.N.OS(O)(=O)=O BFNBIHQBYMNNAN-UHFFFAOYSA-N 0.000 description 1
- 229910052921 ammonium sulfate Inorganic materials 0.000 description 1
- 235000011130 ammonium sulphate Nutrition 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 229910052797 bismuth Inorganic materials 0.000 description 1
- 238000001354 calcination Methods 0.000 description 1
- 229910002091 carbon monoxide Inorganic materials 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000008602 contraction Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000010908 decantation Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 239000002270 dispersing agent Substances 0.000 description 1
- 238000002848 electrochemical method Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 239000011790 ferrous sulphate Substances 0.000 description 1
- 235000003891 ferrous sulphate Nutrition 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 229910052598 goethite Inorganic materials 0.000 description 1
- 239000008187 granular material Substances 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- AEIXRCIKZIZYPM-UHFFFAOYSA-M hydroxy(oxo)iron Chemical compound [O][Fe]O AEIXRCIKZIZYPM-UHFFFAOYSA-M 0.000 description 1
- 235000014413 iron hydroxide Nutrition 0.000 description 1
- 229910000359 iron(II) sulfate Inorganic materials 0.000 description 1
- 229910021519 iron(III) oxide-hydroxide Inorganic materials 0.000 description 1
- NCNCGGDMXMBVIA-UHFFFAOYSA-L iron(ii) hydroxide Chemical compound [OH-].[OH-].[Fe+2] NCNCGGDMXMBVIA-UHFFFAOYSA-L 0.000 description 1
- 235000010746 mayonnaise Nutrition 0.000 description 1
- 239000008268 mayonnaise Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000012452 mother liquor Substances 0.000 description 1
- LGQLOGILCSXPEA-UHFFFAOYSA-L nickel sulfate Chemical compound [Ni+2].[O-]S([O-])(=O)=O LGQLOGILCSXPEA-UHFFFAOYSA-L 0.000 description 1
- 229910000363 nickel(II) sulfate Inorganic materials 0.000 description 1
- 239000003973 paint Substances 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000006722 reduction reaction Methods 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 238000004513 sizing Methods 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000000967 suction filtration Methods 0.000 description 1
- 239000006228 supernatant Substances 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- 239000012808 vapor phase Substances 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
- 229910006297 γ-Fe2O3 Inorganic materials 0.000 description 1
Abstract
Description
【発明の詳細な説明】 本発明は針状酸化鉄またはＮｉ、Ｃｏ、Ｚｎ。[Detailed description of the invention] The present invention uses acicular iron oxides or Ni, Co, and Zn.
Ｍｎ等の元素を含む変性針状酸化鉄を水素ガス等の還元
性ガスで加熱還元することからなる、Ｆｅを主成分とす
る金属磁性粉末の製造方法に関する。The present invention relates to a method for producing metal magnetic powder containing Fe as a main component, which comprises heating and reducing modified acicular iron oxide containing elements such as Mn with a reducing gas such as hydrogen gas.
さらに詳しくは、Ｓｉまたはｌの水酸化物のコロイド溶
液を厳密に制御した条件の下で生成させ、このコロイド
溶液を用いて原料である針状酸化鉄を処理することによ
り針状酸化鉄表面にＳｉまたはＡｆｌの均一な被着層を
形成させ、ついでこれを還元することにより針状酸化鉄
の針状形骸に由来する形状異方性を保持しており、かつ
Ｈｅが１，４００〜１．８０００ｅである金属磁性粉末
を製造する方法、あるいは、所望によりさらにその金属
磁性粉末をＨとＣＯ２の混合ガスで処理することによっ
て粉末の表面を酸化物として安定化させた、針状性と分
散性に優れ、空気中で安定な金属磁性粉末を製造する方
法を提供するものである。More specifically, a colloidal solution of Si or l hydroxide is generated under strictly controlled conditions, and the raw material acicular iron oxide is treated with this colloidal solution to form a surface of acicular iron oxide. By forming a uniform adhesion layer of Si or Afl and then reducing it, the shape anisotropy derived from the acicular shape of the acicular iron oxide is maintained, and the He content is 1,400 to 1. 8000e, or if desired, the metal magnetic powder is further treated with a mixed gas of H and CO2 to stabilize the surface of the powder as an oxide, with acicularity and dispersibility. The present invention provides a method for producing metal magnetic powder that has excellent properties and is stable in the air.
尚、上記のＨとＣＯ２の混合ガスで前処理して安定化さ
せる方法は、他の任意の方法で針状酸化鉄を還元してつ
くられた金属磁性粉末の安定化にも有効である。Note that the method of stabilizing by pretreatment with a mixed gas of H and CO2 described above is also effective for stabilizing metal magnetic powder produced by reducing acicular iron oxide by any other method.
［従来の技術］
オキシ水酸化鉄または酸化鉄を還元性ガス、例えばＮ２
で還元して得られる金属磁性粉末は、本質的に、酸化物
系磁性粉末例えばγ−Ｆｅ２Ｏ３等に比べて高い保磁力
（Ｈｅ）、大きな飽和磁気モーメント（σＳ）を保有し
ているので高密度磁気記録用材料として優れた特性を有
しており、近年８ｍ■ビデオテープおよびＤＡＴテープ
に使用され始め、実用化されつつある。[Prior art] Iron oxyhydroxide or iron oxide is exposed to a reducing gas such as N2.
The metal magnetic powder obtained by reduction essentially has a higher coercive force (He) and a larger saturation magnetic moment (σS) than oxide-based magnetic powders such as γ-Fe2O3, so it has a high density. It has excellent properties as a magnetic recording material, and has recently begun to be used in 8m video tapes and DAT tapes, and is being put into practical use.
これらメタル粉と称されるＦｅを主成分とした金属磁性
粉末粒子の製造には一般に気相還元法が用いられている
。しかし、この気相還元法では粉末粒子がα−Ｆ ｅ
００ Ｈ→ａ −Ｆ ｅ ２０ ａ →Ｆｅ３Ｏ４→α
−Ｆｅという反応過程を通るので、結晶構造の変化とそ
れに伴なう体積収縮が起こる。A gas phase reduction method is generally used to produce metal magnetic powder particles containing Fe as a main component, which are called metal powders. However, in this gas phase reduction method, the powder particles are α-Fe
00 H→a −F e 20 a →Fe3O4→α
Since it passes through the -Fe reaction process, a change in crystal structure and an accompanying volume contraction occur.
この体積収縮は最終的に約４７％にも達するので、上記
の変態の過程において粒子相互の融着や粒子自体の焼結
が発生し、形状が崩れる。その結果、従来の気相還元法
で得られる金属磁性粉末は、−般に、形状磁気異方性が
低く、したがってＨｅが低く又分散性の悪いものとなり
がちであった。This volumetric shrinkage ultimately reaches about 47%, so that during the above-mentioned transformation process, particles are fused together and the particles themselves are sintered, causing the shape to collapse. As a result, metal magnetic powders obtained by conventional gas phase reduction methods generally have low shape magnetic anisotropy, and therefore tend to have low He content and poor dispersibility.
そこで、この粒子相互の融着や粒子自体の焼結を防止し
て所定の特性を有する金属磁性粉末を得る方法がいろい
ろと研究され、その成果として、原料酸化鉄をＰ、Ｓｉ
、Ａｌｌ 、Ｚｎ 、Ｚｒ 、Ｔｉ ＊８１等の金属
の塩またはそれらの金属の水酸化物で表面処理した後に
還元することによって、得られるＦｅを主成分とする磁
性粉末の形骸を良好に保持する方法が種々開示されてい
る（例えば、特開昭４８−７９１５３、特公昭５１−５
８０８等多数）。これらの開示された方法はＰ、Ｓｉ、
Ａｇ、Ｚｎ。Therefore, various researches have been conducted on methods to obtain metal magnetic powder with predetermined characteristics by preventing the fusion of the particles and the sintering of the particles themselves.
, All, Zn, Zr, Ti*81, etc., by surface treatment with salts of metals or hydroxides of those metals, and then reduction, the resulting magnetic powder containing Fe as its main component retains its shape well. Various methods have been disclosed (for example, Japanese Patent Publication No. 48-79153, Japanese Patent Publication No. 51-5
808 etc.). These disclosed methods include P, Si,
Ag, Zn.
Ｚｒ、ＴＩ 、Ｂｉ等種々の金属の塩またはそれらの金
属の水酸化物を酸化鉄の表面に生成させることにより、
粒子相互の融着と粒子自体の焼結を防止して針状形骸を
保持させようとする方法であり、一応の成果をあげてい
るが、これらの方法によって得られる金属磁性粉の針状
性は十分に良好とは言い難く、近年−層求められている
高密度磁気記録媒体用金属磁性粉末としては十分満足で
きるものではなかった。By generating salts of various metals such as Zr, TI, Bi, or hydroxides of these metals on the surface of iron oxide,
This method attempts to retain the acicular shape by preventing the particles from fusing together and sintering the particles themselves, and has achieved some success, but the acicular nature of the metal magnetic powder obtained by these methods is It cannot be said that the results are sufficiently good, and the metal magnetic powder is not fully satisfactory as a metal magnetic powder for high-density magnetic recording media, which has been in demand in recent years.
又、これらの金属磁性粉末は極めて酸化され易く、その
取扱いは非常に注意を要した。その対策としては、還元
終了したメタル粉をトルエン等の有機溶剤中に取出した
後風乾する方法や、あるいはトルエン中に浸漬したまま
トルエン中に空気を吹きこむことにより金属磁性粒子の
表面を酸化して安定化させた後、有機溶剤を乾燥除去し
て空気中に取出す方法や、還元して得た金属磁性粉末を
室温に冷却後、Ｎ２と空気との混合気体に接触させ、徐
々に混合ガスの酸素分圧（Ｐｏ。）を増加することによ
り金属磁性粒子表面を徐々に酸化してゆき、燃焼させる
ことなく空気中に取出す方法（特公昭４７−３０４７７
、同５１−５６０８）等に頼ることが一般に行なわれて
いる。Furthermore, these metal magnetic powders are extremely susceptible to oxidation, and their handling requires great care. As a countermeasure, the metal powder after reduction is taken out in an organic solvent such as toluene and air-dried, or the surface of the metal magnetic particles is oxidized by blowing air into the toluene while immersed in the toluene. After stabilization, the organic solvent is removed by drying and taken out into the air.The metal magnetic powder obtained by reduction is cooled to room temperature, and then brought into contact with a gas mixture of N2 and air, and the mixed gas is gradually removed. A method of gradually oxidizing the surface of metal magnetic particles by increasing the oxygen partial pressure (Po.
, 51-5608) and the like.
しかしながら、トルエン等の有機溶剤を使用して金属磁
性粒子表面を安定化する方法は金属磁性粒子の触媒作用
により有機溶剤の変性物が生成する現象を伴うことが認
められており、塗布型磁気記録媒体を作製するための塗
料化に際して、分散剤やバインダーの組成によっては凝
集が著しく、塗布によって得られる製品が角形比、表面
性の劣るものとなるので好ましくないと指摘されている
。However, it has been recognized that the method of stabilizing the surface of metal magnetic particles using an organic solvent such as toluene is accompanied by a phenomenon in which a modified product of the organic solvent is generated due to the catalytic action of the metal magnetic particles. It has been pointed out that when making a coating for producing a medium, it is undesirable because depending on the composition of the dispersant and binder, aggregation may be significant and the product obtained by coating may have poor squareness and surface properties.
一方、Ｎ と空気の混合ガスを用い、そのＰ ０２（酸
素分圧）を制御しながら固−気反応により粒子表面に徐
々に酸化物被膜を生成させていく方法は、トルエン等の
有機溶剤を使用する場合と異なり、有機溶剤の変性物の
生成という問題は起こらず、さらにまた、大量の有機溶
剤の使用という必要性もないためコスト的にも有利であ
る。しかし、反面著しく酸素に対して活性な金属磁性粉
末粒子に気相にて酸素を導入する方法であるため、それ
に使用する装置仕様や被酸化物の性状（粉末、グラニュ
ー状、クラム等）、酸素分圧増加のスケジュール、Ｎ２
−空気混合ガスの流量等種々多数の因子により熱収支が
大きく左右され、酸化途中あるいは取出時に燃焼するこ
ともあり、微妙な制御を必要とする。又この方法では、
所定の経時安定性を確保するためには金属磁性粉末の表
面活性点を、できるだけ少なくしなければならないため
、やや焼結気味の金属磁性粉が得られる温度において還
元することや、あるいは還元温度より高い温度に保った
Ｎ２等の不活性ガス雰囲気中で熱処理すること（特開昭
６１−５６２０１）等が必要となり、そのために得られ
る製品の分散性、針状性を犠牲にする場合もあるのが現
状である。On the other hand, a method that uses a mixed gas of N and air to gradually form an oxide film on the particle surface through a solid-gas reaction while controlling the P02 (oxygen partial pressure) Unlike when using organic solvents, the problem of generation of modified organic solvents does not occur, and furthermore, there is no need to use large amounts of organic solvents, which is advantageous in terms of cost. However, on the other hand, since it is a method of introducing oxygen in the vapor phase into metal magnetic powder particles that are extremely active against oxygen, the specifications of the equipment used, the properties of the material to be oxidized (powder, granules, crumbs, etc.) Schedule of partial pressure increase, N2
-The heat balance is greatly affected by a large number of factors such as the flow rate of the air mixture gas, and combustion may occur during oxidation or during extraction, so delicate control is required. Also, in this method,
In order to ensure the desired stability over time, the number of surface active sites in the metal magnetic powder must be reduced as much as possible. Heat treatment in an inert gas atmosphere such as N2 kept at a high temperature (Japanese Unexamined Patent Publication No. 61-56201) is required, which may sacrifice the dispersibility and acicularity of the resulting product. is the current situation.
［発明が解決しようとする問題点コ
本発明は上記従来技術の欠点を改良して、還元時に、形
状の崩れおよび粒子同士の融着を生ずることが少なく、
塗料にして使用したときの角形比と分散性に優れ、又、
経時安定性にも優れた金属磁性粉末を製造する方法を提
供するものである。[Problems to be Solved by the Invention] The present invention improves the above-mentioned drawbacks of the prior art, and reduces the occurrence of shape collapse and fusion of particles during reduction.
It has excellent squareness ratio and dispersibility when used as a paint, and
The object of the present invention is to provide a method for producing metal magnetic powder that also has excellent stability over time.
［問題点を解決するための手段］
本発明者らはこれらの問題点を解決するため、主として
Ａｇ系処理剤を用いての表面処理について鋭意研究を重
ねた結果、針状酸化鉄を加熱還元する際の焼結や形骸の
崩れを防止し、出発原料たる針状酸化鉄の粒子形状をよ
く継承した金属磁性粉末を得る方法として、アルミニウ
ム水酸化物コロイドを処理剤として使用する方法を開発
した。[Means for Solving the Problems] In order to solve these problems, the present inventors have conducted extensive research on surface treatment mainly using Ag-based treatment agents, and as a result, we have succeeded in reducing acicular iron oxide by heating. In order to prevent sintering and loss of shape during processing, and to obtain metal magnetic powder that retains the particle shape of the acicular iron oxide starting material, we have developed a method that uses aluminum hydroxide colloid as a processing agent. .
本発明の方法に従い、アルミニウム水酸化物コロイドを
、その生成条件を厳密に制御して調製することにより、
微細かつ均一な分布のアルミニウム水酸化物コロイドを
生成させ、これを針状酸化鉄スラリーと混合して電気化
学的方法により針状酸化鉄表面に吸着または被着させる
ならば、従来行なわれてきた針状酸化鉄のスラリー中で
溶解したアルミニウムイオンを中和して針状酸化鉄表面
に水酸化アルミニウムを吸着または被着させる方法に比
べ、−段とアルミニウム水酸化物の吸着層が緻密かつ均
一となり、従来得られていたものより優れた角形比、分
散性を有するメタル粉を製造できることが見出された。According to the method of the present invention, aluminum hydroxide colloid is prepared by strictly controlling the production conditions.
If a fine and uniformly distributed aluminum hydroxide colloid is produced, mixed with an acicular iron oxide slurry, and adsorbed or deposited on the acicular iron oxide surface by an electrochemical method, this method has been conventionally carried out. Compared to the method in which aluminum ions dissolved in a slurry of acicular iron oxide are neutralized and aluminum hydroxide is adsorbed or deposited on the surface of acicular iron oxide, the adsorption layer of aluminum hydroxide is dense and uniform. It has been found that it is possible to produce metal powder having a better squareness ratio and dispersibility than those previously obtained.
本発明において、原料として用いる針状酸化鉄としては
、一般に針状のα−Ｆｅ００Ｈが用いられるがａ−Ｆｅ
２０３および７−ＦｅＯＯＨも使用できる。In the present invention, as the acicular iron oxide used as a raw material, acicular α-Fe00H is generally used, but a-Fe
203 and 7-FeOOH can also be used.
これら針状酸化鉄にはＧｏ、Ｎｌ 、Ｚｎ、Ｍｎ等が含
まれていてもさしつかえな〈従来公知のいずれの方法（
例えば、特公昭５３−２７７１９．同５５−２３７７３
）で製造されたものであってもよい。−船釣には硫酸鉄
水溶液と水酸化ナトリウム水溶液を反応させ、ついで空
気に代表される酸化性ガスを吹きこむ方法で製造される
長軸長０．１−０．５μ、軸比１０〜２０のα−Ｆｅ０
０Ｈが好適であり、特に保磁力（Ｈｃ）が１．４０Ｑ
〜１．６ＱＯＯｅである８■ビデオテープおよびＤＡＴ
テープ用磁外磁性粉末料となる針状酸化鉄としては、硫
酸鉄水溶液に硫酸塩、塩化物等の水溶液としてＮ１また
はＣｏを添加した水溶液を水酸化ナトリウム水溶液と反
応させ、ついで酸化反応を行なうことにより製造したα
−ＦｅＯＯＨが好適である。These acicular iron oxides may contain Go, Nl, Zn, Mn, etc. (using any conventionally known method).
For example, Special Publication No. 53-27719. 55-23773
) may be manufactured. - For boat fishing, manufactured by a method of reacting an aqueous iron sulfate solution with an aqueous sodium hydroxide solution and then blowing an oxidizing gas such as air into the product.Major axis length 0.1-0.5μ, axial ratio 10-20 α-Fe0
0H is suitable, especially coercive force (Hc) is 1.40Q
8 ■ Videotape and DAT with ~1.6QOOe
Acicular iron oxide, which is used as an extramagnetic powder material for tapes, is obtained by reacting an aqueous solution of iron sulfate with N1 or Co as an aqueous solution of sulfate, chloride, etc. with an aqueous sodium hydroxide solution, and then carrying out an oxidation reaction. α manufactured by
-FeOOH is preferred.
又、本発明においては酸化反応後の針状水酸化鉄は反応
母液から分離した後、Ｎ ａ ２ Ｓ Ｏ４等に代表さ
れる雑塩を十分に洗浄、除去することが特に重要である
。本発明者らはアルミニウム水酸化物を針状酸化鉄に被
着させるための処理を種々の方法で行なって不純物元素
が金属磁性粉末の特性に与える影響について詳細に検討
を重ねた結果、酸化鉄粒子の表面または内部に存在する
ＮａおよびＳ０３は加熱還元時における粒子同士の融着
や粒子形態の崩れや軸比の低下をひき起こす原因となり
、金属磁性粉のＨｅに対し著しい影響を与えることを見
出した。特に、アルミニウム化合物を針状酸化鉄に被着
処理する場合にはＳｉを被着処理する場合よりも、上記
影響が大きく現われることを知った。Ｎａ及びＳ０３の
含有量を、Ｎａは０．０７％以下、好ましくは０．０５
％以下に、Ｓ０３は０．５％以下、好ましくは０．３％
以下に制御すれば１．４００〜１．８０００ｅという所
望のＨＣを保持した分散性および角形比が極めて良好な
金属磁性粉末が得られる。したがって、上記の指針にし
たがい、ＮａおよびＳ０３を十分に洗浄、除去した針状
酸化鉄にアルミニウム化合物を被着処理した後整粒、乾
燥、焼成及び還元、酸化して金属磁性粉末をつくるべき
である。本発明はアルミニウム化合物を被着処理するに
際し、水酸化アルミニウムのコロイドを用いて、被還元
物である酸化鉄粒子表面を処理するのが重要な特徴の一
つである。水酸化アルミニウムのコロイド溶液は次のよ
うにしてつくることができる。すなわち、水溶性アルミ
ニウム化合物の水溶液を２０℃以下の温度で完全中和す
ることにより、水溶性アルミニウム化合物を水酸化アル
ミニウムとして沈澱させ、この沈澱を洗浄した後ＨＣＪ
Ｉ！で解膠してコロイド溶液とする。又、別の方法とし
て、Ａｆｆ （ＳＯ２）３゜Ｎ ａ Ａ ＩＩ ０
２ 、Ｐ Ａ Ｃ等のアルミニウム化合物の水溶液をつ
くり、これらを２０℃以下の温度に調整して、それぞれ
の中和当量の６０％相当分のアルカリまたは酸を加えて
溶液を部分中和し、残存の酸またはアルカリで解膠して
コロイド溶液とすることもできる。上記いずれの場合に
おいても、溶液の温度が２０℃以上では生成する水酸化
アルミニウムが完全にはコロイドとなりにくいので好ま
しくない。Furthermore, in the present invention, after the acicular iron hydroxide is separated from the reaction mother liquor after the oxidation reaction, it is particularly important to sufficiently wash and remove miscellaneous salts such as Na 2 SO 4 and the like. The present inventors conducted various treatments to deposit aluminum hydroxide on acicular iron oxide, and as a result of detailed studies on the effects of impurity elements on the properties of metal magnetic powder, we found that iron oxide Na and S03 present on the surface or inside the particles cause fusion between particles, collapse of particle morphology, and decrease in axial ratio during thermal reduction, and have a significant effect on He in metal magnetic powder. I found it. In particular, it has been found that when an aluminum compound is applied to acicular iron oxide, the above-mentioned influence appears more greatly than when Si is applied. The content of Na and S03 is 0.07% or less, preferably 0.05%.
%, S03 is 0.5% or less, preferably 0.3%
If controlled as follows, a metal magnetic powder having a desired HC of 1.400 to 1.8000e and having extremely good dispersibility and squareness ratio can be obtained. Therefore, according to the above guidelines, metal magnetic powder should be produced by coating acicular iron oxide, which has been thoroughly cleaned and removed from Na and S03, and then applying an aluminum compound, followed by sizing, drying, firing, reduction, and oxidation. be. One of the important features of the present invention is that when applying an aluminum compound, a colloid of aluminum hydroxide is used to treat the surface of iron oxide particles, which are to be reduced. A colloidal solution of aluminum hydroxide can be prepared as follows. That is, by completely neutralizing an aqueous solution of a water-soluble aluminum compound at a temperature of 20° C. or lower, the water-soluble aluminum compound is precipitated as aluminum hydroxide, and after washing this precipitate, HCJ
I! peptize it to make a colloidal solution. Also, as another method, Aff (SO2)3゜N a A II 0
2. Prepare an aqueous solution of an aluminum compound such as PAC, adjust the temperature to 20 ° C. or lower, and partially neutralize the solution by adding an alkali or acid equivalent to 60% of the neutralization equivalent of each solution, It can also be peptized with residual acid or alkali to form a colloidal solution. In any of the above cases, if the temperature of the solution is 20° C. or higher, it is not preferable because the aluminum hydroxide produced is difficult to completely turn into a colloid.
このようにして得たコロイド溶液による酸化鉄の処理は
、コロイド溶液の所定量を針状酸化鉄のスラリーに添加
混合して６０℃に加温することにより行なう。これによ
りアルミニウム化合物を針状酸化鉄表面に均一に被着さ
せることができる。水溶性アルミニウム化合物としては
アルミン酸ナトリウム、硫酸アルミニウム、ポリ塩化ア
ルミニウム等が使用できる。Treatment of iron oxide with the colloidal solution thus obtained is carried out by adding and mixing a predetermined amount of the colloidal solution to a slurry of acicular iron oxide and heating the mixture to 60°C. This allows the aluminum compound to be uniformly deposited on the surface of the acicular iron oxide. As the water-soluble aluminum compound, sodium aluminate, aluminum sulfate, polyaluminum chloride, etc. can be used.
本発明の方法によれば、従来公知の方法すなわち、例え
ば、針状酸化鉄のスラリーに水溶性アルミニウム化合物
を加えた後中和を行なうことにより酸化鉄粒子表面にア
ルミニウム化合物を被着させる方法に比べ、形骸粒子の
針状性が優れ、かつ融着合体粒子の存在が少ない金属磁
性粉末が得られる。According to the method of the present invention, an aluminum compound is deposited on the surface of iron oxide particles by adding a water-soluble aluminum compound to a slurry of acicular iron oxide and then neutralizing the slurry. In comparison, a metal magnetic powder with excellent acicularity of skeleton particles and less presence of fused aggregate particles can be obtained.
上記本発明の方法にしたがい、Ｎ１の共存下に、アルミ
ニウム化合物を主処理剤として金属磁性粉を製造する場
合には、用いるアルミニウム化合物の量が、原料酸化鉄
中のＦｅの量に対し１７として１〜１０重量％、好まし
くは３〜６重量％の範囲となるような条件の下でアルミ
ニウム化合物の被着処理を行なった後、洗浄、乾燥し、
ついで非還元性雰囲気中で焼成して結晶性を高めた後、
水素気流中で３２０〜４００℃、好ましくは３５０”Ｃ
近傍で加熱還元すれば、保磁力（Ｈｅ）が１，４００〜
１，６０００ｃを示す金属磁性粉が得られる。When producing metal magnetic powder using an aluminum compound as a main treatment agent in the coexistence of N1 according to the method of the present invention, the amount of the aluminum compound used is 17% relative to the amount of Fe in the raw material iron oxide. After applying an aluminum compound under conditions such that the amount is in the range of 1 to 10% by weight, preferably 3 to 6% by weight, the aluminum compound is washed, dried,
Then, after increasing the crystallinity by firing in a non-reducing atmosphere,
320-400°C, preferably 350”C in a hydrogen stream
If heated and reduced in the vicinity, the coercive force (He) will increase from 1,400 to
A metal magnetic powder having a particle diameter of 1,6000c is obtained.
この場合、非還元性雰囲気での焼成温度が余りにも高い
場合はこの時点でα−Ｆｅ２０３の焼結が起こるので、
焼成温度は６５０〜８００℃の範囲とするのが好ましい
。また、場合によっては上記の熱処理を行なわずに、次
工程の還元工程で温度を調節することにより上記焼成と
同等な効果をあげることができる場合もある。In this case, if the firing temperature in a non-reducing atmosphere is too high, sintering of α-Fe203 will occur at this point.
The firing temperature is preferably in the range of 650 to 800°C. Further, in some cases, the same effect as the above-mentioned calcination can be achieved by adjusting the temperature in the next reduction step without performing the above-mentioned heat treatment.
還元温度が、例えば４５０℃というような高い温度とな
った場合には、本発明のコロイド溶液処理方法によって
も加熱還元時におけるＦｅ結晶同士の焼結が起こるのを
回避することが困難となり、その結果、得られる粉末は
、軸比が減少し保磁力（Ｈｅ）の低下したものとなる。When the reduction temperature is as high as 450°C, it becomes difficult to avoid sintering of Fe crystals during thermal reduction even with the colloidal solution treatment method of the present invention. As a result, the obtained powder has a reduced axial ratio and a reduced coercive force (He).
次に安定化の方法について説明する。Next, the stabilization method will be explained.
還元の完了により得られた金属磁性粉末は、それを通常
室温にまで冷却した後、Ｎ２と空気の混合ガス中で酸素
分圧を調節しながら金属磁性粒子表面に徐々に酸化物層
を形成していく方法や、金属粉末をトルエン等の有機溶
剤中に取出し、該溶剤に空気等の酸化性ガスを導入して
磁性粉の表面を酸化していく等の方法によって安定化す
ることが一般に行なわれている。After the metal magnetic powder obtained by completing the reduction is cooled to normal room temperature, an oxide layer is gradually formed on the surface of the metal magnetic particles while adjusting the oxygen partial pressure in a mixed gas of N2 and air. Generally, stabilization is carried out by a method such as taking the metal powder into an organic solvent such as toluene and introducing an oxidizing gas such as air into the solvent to oxidize the surface of the magnetic powder. It is.
これらの方法のうち、トルエン等の有機溶剤中で酸化す
る方法は、酸化途中において鉄磁性粉の触媒作用により
有機物の重合、変性が発生し、塗料化工程で悪影響を及
ぼすことが認められ、又Ｎ２と空気の混合ガスを用いて
、その酸素分圧を制御する方法は、好ましい方法ではあ
るが時として酸化反応が急激に進み金属磁性粉の特性を
劣化することがある。Among these methods, the method of oxidizing in an organic solvent such as toluene is known to cause polymerization and modification of organic substances due to the catalytic action of iron magnetic powder during oxidation, which has an adverse effect on the coating process. Although the method of controlling the oxygen partial pressure using a mixed gas of N2 and air is a preferable method, the oxidation reaction sometimes progresses rapidly and the characteristics of the metal magnetic powder deteriorate.
本発明者らは上記の問題点を解決するため、次のような
方法を開発した。すなわち、２００〜４５０℃という還
元温度程度の温度でＮ２とＣＯ２の混合ガスに金属粉末
を接触させ、この場合のＮ２とＣＯ２の混合比を熱力学
的計算に基づいて制御することにより、Ｆｅを主成分と
する金属磁性粒子の表面近傍を酸化物の状態とし、しか
る後に、この金属粉末をＮ２と空気の混合ガスに接触さ
せ、その際のＮ２と空気の混合比を以下に述べるように
変えることによって、すなわち、比較的低い温度におい
て酸素分圧（Ｐｏ ）をＩＯ’ａＬｍから徐々に増加
していくことにより、表面酸化を徐々に進行させ、緻密
なα−Ｆｅ２０３層を形成させる方法である。The present inventors developed the following method in order to solve the above problems. That is, by bringing metal powder into contact with a mixed gas of N2 and CO2 at a temperature of 200 to 450°C, which is about the reduction temperature, and controlling the mixing ratio of N2 and CO2 in this case based on thermodynamic calculations, Fe can be removed. The vicinity of the surface of the metal magnetic particles as the main component is made into an oxide state, and then this metal powder is brought into contact with a mixed gas of N2 and air, and the mixing ratio of N2 and air at that time is changed as described below. In other words, by gradually increasing the oxygen partial pressure (Po) from IO'aLm at a relatively low temperature, surface oxidation is gradually progressed to form a dense α-Fe203 layer. .
ＨとＣＯ２の混合ガスによる金属磁性粒子の表面酸化反
応は次式で示される。The surface oxidation reaction of metal magnetic particles by a mixed gas of H and CO2 is expressed by the following equation.
Ｈ＋ＣＯ−ＨＯ＋ＣＯ（１）
３Ｆｅ ＋４Ｈ２０−Ｆｅ３０４＋４Ｈ２（２）（１）
、 （２）式の平衡関係を、熱力学的計算によってＦ
ｅ３Ｏ４の存在が安定である領域に相当するＨ とＣＯ
２の組成比を決定する。しかし、酸化の反応速度は物質
移動現象に支配されるので、制御可能な酸化速度とする
ために入念な実験を行なって、実際のＮ２：ＣＯ２の組
成比およびガス流量の絶対量を決定した。例えば、前述
の処理例の場合、３５０℃では全圧１ ａｔｌｌに対し
Ｐｃｏ２−０、ｌａｔｍでは酸化が急速すぎて、適正な
表面酸化度に制御することが困難であるが、Ｐ ＣＯ２
＝０．００２ａｔａ＋では制御可能な酸化速度となる。H+CO-HO+CO(1) 3Fe +4H20-Fe304+4H2(2)(1)
, The equilibrium relationship in equation (2) is calculated by thermodynamic calculation as F
H and CO corresponding to the region where the presence of e3O4 is stable
Determine the composition ratio of 2. However, since the oxidation reaction rate is controlled by mass transfer phenomena, careful experiments were conducted to determine the actual N2:CO2 composition ratio and the absolute amount of gas flow rate in order to obtain a controllable oxidation rate. For example, in the case of the above-mentioned treatment example, oxidation is too rapid at Pco2-0, latm for a total pressure of 1 atll at 350°C, and it is difficult to control the degree of surface oxidation to an appropriate level.
=0.002 ata+ provides a controllable oxidation rate.
３５０℃ではＰｃｏ２は０．００１〜０．０５ａｔｉが
好ましく、酸化時間は５分〜３００分が適当である。３
５０℃−Ｎ２流ｆｆｉ ４．５Ｎ１／ｍｉｎ −Ｃ０２
流量０．５Ｎｇ／ｓｉｎという条件（Ｐｃｏ２０．１ａ
ｔｆｆｌに相当する）では酸化反応は急速に進行し、１
５分でσ５（Ｆｅ）は２００ｅｍｕ／ ｇ−Ｆ ｅから
１２０ｅｍｕ／ ｇ −Ｆ ｅにまで低下し、Ｈｅも１
．４８００ｅから８６００ｅまで低下した。At 350°C, Pco2 is preferably 0.001 to 0.05ati, and the oxidation time is suitably 5 minutes to 300 minutes. 3
50℃-N2 flow ffi 4.5N1/min -C02
Conditions of flow rate 0.5Ng/sin (Pco20.1a
(corresponding to tffl), the oxidation reaction proceeds rapidly, and 1
In 5 minutes, σ5(Fe) decreased from 200 emu/g-Fe to 120 emu/g-Fe, and He also decreased to 1
．． It decreased from 4800e to 8600e.
この様にしてあらかじめ表面に適正量の酸化物層を生成
させた金属磁性粉末は、Ｎ２ガス等の不活性ガス雰囲気
中で室温近傍にまで冷却した後、Ｎ と空気を混合して
Ｐ ｏ ＝ １０−”ａｔＩｍから酸化を始め、徐々
にＰ Ｏ２を増加していく公知の技術（特公昭４７−３
０４７７、同５１−５８０８）と同様の操作によりＦ
ｅ ｓ Ｏ４をα−Ｆｅ２０３へと酸化させて安定化し
、空気中へ取出すことができる。この方法によれば金属
磁性粉末の安定化に必要な処理時間も短かく、σＳの経
時変化は通常のＰ Ｏ２制御法に比べて少ないことが認
められた。The metal magnetic powder, on which an appropriate amount of oxide layer has been formed on the surface in advance, is cooled to near room temperature in an inert gas atmosphere such as N2 gas, and then mixed with N and air to form P o = A known technique (Japanese Patent Publication No. 47-3
F by the same operation as 0477, 51-5808).
The e s O4 is oxidized to α-Fe203, stabilized, and can be taken out into the air. According to this method, the processing time required for stabilizing the metal magnetic powder is short, and it has been found that the change in σS over time is smaller than in the normal PO2 control method.
［実 施 例］ 以下実施例により本発明を具体的に説明する。[Example] The present invention will be specifically explained below using Examples.
実施例 １゜
硫酸第１鉄および硫酸ニッケルの混合水溶液（Ｎｌ／Ｆ
ｅ−３％）と水酸化ナトリウム水溶液とを反応させ、中
和生成物をさらに空気で酸化して生成させたα−Ｆｅ０
０Ｈ（長軸長平均ＯＪμ、平均軸比１８）のスラリーを
ろ過、洗浄後リパルプしてＮａおよびＳ０３を十分に除
去した。Example 1゜Mixed aqueous solution of ferrous sulfate and nickel sulfate (Nl/F
α-Fe0 produced by reacting (e-3%) with an aqueous sodium hydroxide solution and further oxidizing the neutralized product with air.
The slurry of 0H (long axis length average OJμ, average axis ratio 18) was filtered, washed, and repulped to sufficiently remove Na and S03.
ａ −Ｆ ｅ ＯＯＨノスラリ−（２０ｇ／Ｉで１００
ｇ。a -F e OOH Noslary (100 at 20g/I
g.
２５℃）にあらかじめ別個に調製した水酸化アルミニウ
ムコロイドを所定量（ＡｊＪ／Ｆｅ −６％となる量）
加え、３０分間攪拌を続けた。その後ｌＮ−ＮａＯＨ水
溶液によりｐＨを８〜９に調節し、６０℃に昇温しで１
時間熟成し、水酸化アルミニウムコロイドで処理された
針状ゲーサイトをつくった。A predetermined amount (amount giving AjJ/Fe -6%) of aluminum hydroxide colloid prepared separately in advance at 25°C)
and continued stirring for 30 minutes. After that, the pH was adjusted to 8 to 9 with a 1N-NaOH aqueous solution, and the temperature was raised to 60°C.
Time-aged and treated with aluminum hydroxide colloid made acicular goethite.
く水酸化アルミニウムコロイドの調整〉アルミン酸ナト
リウムの水溶液（Ａ ｉ） ２０ ａとして２９９ｇ／
ｉｔ）を１００ｍ１取り、純水を２００ｍ１加えた後、
１５℃に保持しつつＩＮ−Ｈ（Ｊ）水溶液９２０ ｍｌ
を加えてｐＨを７．５に調整した。次いで、純水を５０
０ｍ１加えた後、攪拌を止めて静置し、上澄を捨てデカ
ンテーション洗浄を行ない、ヌッチェで吸引ろ過し洗浄
した。次いでケーキを純水３００ｍ１にてリパルプしＩ
Ｎ−ＨＣｇ水溶液１７８ｍ１を加え、このコロイドを解
膠した。Preparation of aluminum hydroxide colloid> Aqueous solution of sodium aluminate (A i) 299g/20a
After taking 100ml of it) and adding 200ml of pure water,
920 ml of IN-H(J) aqueous solution while maintaining at 15℃
was added to adjust the pH to 7.5. Next, add 50% pure water
After adding 0 ml, stirring was stopped and the mixture was allowed to stand, the supernatant was discarded and the mixture was washed by decantation, followed by suction filtration with a Nutsche filter and washing. The cake was then repulped with 300 ml of pure water.
178 ml of N-HCg aqueous solution was added to peptize the colloid.
水酸化アルミニウムコロイドの添加によって、水酸化ア
ルミニウムを被着させたＮｉ含含有−Ｆｅ００Ｈを純水
で十分洗浄し、ＮａおよびＳ０３を除去した。洗浄後の
α−Ｆｅ００ＨのＮａ含有量は０．０４５％、Ｓ０３含
有量は０．０２％であった。By adding aluminum hydroxide colloid, the Ni-containing -Fe00H coated with aluminum hydroxide was sufficiently washed with pure water to remove Na and S03. The Na content of α-Fe00H after washing was 0.045%, and the S03 content was 0.02%.
このα−Ｆｅ００Ｈを長さ約’７ｒｒｓｓ直径３ｍｍの
円柱状クラムに造粒整像後乾燥した。さらに、７００℃
で３０分間焼成した後、たて型固定層還元装置に２５ｇ
挿入し、Ｈ２ガス流量５Ｎｇ／ｒＡｉｎで３５０℃−１
０ｈ「還元を行なった。一部をトルエン中へ取出し、Ｖ
ＳＭ （印加磁場１０ＫＯｅ）にて粉体磁気特性を測定
したところ、ｐＨｃ −１，４８００ｅ 。This α-Fe00H was granulated into cylindrical crumbs with a length of about 7 mm and a diameter of 3 mm, and then dried. Furthermore, 700℃
After baking for 30 minutes, 25g was placed in a vertical fixed bed reduction device.
Insert and heat at 350℃-1 with H2 gas flow rate of 5Ng/rAin.
0h "Reduction was carried out. Take out a part in toluene and
When the powder magnetic properties were measured under SM (applied magnetic field: 10 KOe), the pHc was −1,4800e.
ｃｙｓ（Ｆｅ）−１９５ｅｗｕ／ ｇ −Ｆｅ 、 ａ
ｒ ／ａｓ −０，５１２であり、良好に還元されてい
た。この金属磁性粉末を３５０℃の温度でＨ２５Ｎ 、
ｌ！ ／ ｍ Ｉ ｎ １ＣＯ２０−０１Ｎ ｆ） ／
ｗｉｎの混合ガス流により１５分間酸化した。得られ
た酸化物の一部をトルエン中へ取出し、ＶＳＭにて粉体
磁気特性を測定したところ、ｐＨｃ −１，４５００ｅ
、 ｃｙｓ −Ｆｅ −１７０ｃｍｕ／ｇ −Ｆｅ
、 ａｒ ／ｌｙｓ ＝０．５１４であり、適正に酸化
されていた。Ｎ２気流中で２０℃まで冷却後、Ｎ ２２
Ｎ ｉ’ ／ ｍ ｉ ｎ １空気０．０１Ｎｉ）
／ａｋｉｎの混合ガス流によりＰ ｏ −１１０−３
ａｔとして、酸化を始め、徐々にＰ Ｏ２を増加してゆ
き、最終的には空気のみ４Ｎｊ）／ｗｉｎの気流とした
。生成物を炉外の空気中へ取出し、磁気特性を１ｐＪ定
したところ、ｐＨｃ −１，４５００ｅ 、 ａｓ −
１２８ｅｍｕ／ ｇｓσｒ ／ａｓ−０，５１５であっ
た。cys(Fe)-195ewu/g-Fe,a
r/as -0,512, indicating good reduction. This metal magnetic powder was heated with H25N at a temperature of 350℃,
l! / m I n 1CO20-01N f) /
The mixture was oxidized for 15 minutes with a mixed gas flow of When a part of the obtained oxide was taken out into toluene and the powder magnetic properties were measured using VSM, the pHc was -1,4500e.
, cys -Fe -170cmu/g -Fe
, ar /lys =0.514, indicating proper oxidation. After cooling to 20°C in a N2 stream, N22
Ni' / min 1 air 0.01Ni)
P o -110-3 due to the mixed gas flow of /akin
At, oxidation was started, and P O2 was gradually increased, and finally an air flow of 4 Nj)/win was made. When the product was taken out into the air outside the furnace and its magnetic properties were determined at 1 pJ, pHc -1,4500e, as -
It was 128 emu/gsσr/as-0,515.
本実施例で得られた金属磁性粉末粒子の３０．０００倍
の電子顕微鏡写真を第１図に示す。針状性が良好に保た
れ融着粒子も少ないことがわかる。この粉末の６０℃−
空気中における３日目のσＳは１２３ｅｍｕ／ ｇであ
り、良好であった。又、６０℃−９０％ＲＨ−７日目の
σＳは１０１０５ｅ ／ ｇであり、良好であった。FIG. 1 shows an electron micrograph of the metal magnetic powder particles obtained in this example at a magnification of 30,000 times. It can be seen that the acicularity is well maintained and there are few fused particles. This powder at 60℃-
The σS on the third day in air was 123 emu/g, which was good. Moreover, the σS on the 7th day at 60° C. and 90% RH was 10105 e/g, which was good.
シート特性を測定した結果、５ｑ−０，７８、ｅｏ’−
ｅｏ°グロス−７０％であった。これら特性値の測定結
果は比較例についての測定結果とともに第１表に示した
。As a result of measuring the sheet properties, 5q-0,78,eo'-
eo° gloss was -70%. The measurement results of these characteristic values are shown in Table 1 together with the measurement results of the comparative examples.
塗料化条件は次のとおりであった。The coating conditions were as follows.
金属磁性粉 ８．０ １００．０トルエン
３．８ ４５．０
次いで、
（マヨネーズびん１５０ｍ１゜
ガラスピーズ８３．３ｇ使用）
比較例 １゜
コロイド添加後の洗浄を調節することによりｌ Ｎａ分
を０．２７％としたこと以外は実施例１と同様の条件で
実験を行なった。還元後トルエン中へサンプリングし、
ＶＳＭにて粉体磁気特性を測定した。ｐＨｃ −９０５
０ｅ ％ ｃｒｓ（Ｆｅ）−２００ｅｍｕ／ｇ −Ｆｅ
、 ａｒ ／ ａｓ ＝０．３８２であった。得られ
た金属磁性粉末粒子は粒子同士の融着が進み、形骸の軸
比も低下し丸味を帯びていた。第２図にその磁性粉末粒
子の３０．０００倍の電子顕微鏡写真を示す。粉末の特
性は第１表に示す通りであった。Metal magnetic powder 8.0 100.0 Toluene
3.8 45.0 Next, (150 ml of mayonnaise bottle, 83.3 g of glass peas used) Comparative Example 1 Example 1 except that the Na content was adjusted to 0.27% by adjusting the washing after adding the colloid. The experiment was conducted under the same conditions. After reduction, sample into toluene,
Powder magnetic properties were measured using VSM. pHc -905
0e% crs(Fe)-200emu/g-Fe
, ar/as = 0.382. In the obtained metal magnetic powder particles, the particles were fused to each other, and the axial ratio of the skeleton was reduced, giving it a rounded shape. FIG. 2 shows an electron micrograph of the magnetic powder particles magnified 30,000 times. The properties of the powder were as shown in Table 1.
比較例 ２゜
コロイド添加後の洗浄したα−Ｆｅ００Ｈに硫安を添加
することにより、Ｓ０３のみ不純物として１．１％残留
させたこと以外は実施例１と同様の条件により還元し、
還元後の金属磁性粉末をトルエン中へサンプリングし、
磁気特性を測定した。 ｐＨｃ ｍｌ、２３００ｅ 、
ｃｙｓ（Ｆｅ）−１９６ｅｒａｕ／ｚ −Ｆｅ ｓ
ｃｙｒ ／ａｓ−０，４９１であった。これらの結果は
第１表に示した。Comparative Example 2゜By adding ammonium sulfate to the washed α-Fe00H after adding colloid, reduction was carried out under the same conditions as in Example 1 except that only S03 remained as an impurity at 1.1%.
Sampling the metal magnetic powder after reduction into toluene,
The magnetic properties were measured. pHc ml, 2300e,
cys(Fe)-196erau/z-Fes
cyr/as-0,491. These results are shown in Table 1.
比較例 ３゜
アルミニウム化合物の添加をコロイドによらず、α−Ｆ
ｅＯＯＨの水性スラリーにアルミン酸ナトリウムを加え
るという形でＡＭを添加し、次いでＩＮ−ＨＣΩを用い
て室温において中和したこと以外は実施例１と同様の条
件で実験を行なった。Comparative example 3゜Aluminum compound addition without colloid α-F
The experiment was conducted under the same conditions as in Example 1, except that AM was added in the form of sodium aluminate to the aqueous slurry of eOOH, followed by neutralization at room temperature with IN-HCΩ.
還元後トルエン中へサンプリングし粉体磁気特性を測定
した。ｐＨｃ ＝１，３５００ｅ ｓ ｃｙｓ（Ｆｅ）
−１８２ｅｉｕ／ ｇ −Ｆ ｅ 、σｒ／σｓ−０
，４９０であった。After reduction, the powder was sampled into toluene and its magnetic properties were measured. pHc = 1,3500 e s cys (Fe)
−182eiu/g −F e , σr/σs−0
,490.
次に、実施例１と同様の条件で酸化安定化して、空気中
へ取出して粉体磁気特性、シート特性、経時安定性を調
べたｏ ｐＨｃ −１，３４００ｅ 、 ａｓ −１
２８ｅｍｕ／ ｇ 、 ａ ｒ ／ ａ ｓ −０，４
９２であった。又、５Ｑ−０，７４、グロス−６０％で
あった。６０℃−空気中の３日目のσＳは１１３ｅｉｕ
／ ｇであり劣化率は１２％、３０℃−９０％ＲＨ−７
日目のａｓは９８ｅｍｕ ／ ｇであった。これらの測
定結果を実施例１の結果と対比して第１表および第２表
に示した。Next, it was oxidized and stabilized under the same conditions as in Example 1, taken out into the air, and examined for powder magnetic properties, sheet properties, and stability over time. pHc -1,3400e, as -1
28 emu/g, a r/a s -0,4
It was 92. Also, 5Q - 0.74, gross - 60%. σS on the third day at 60℃-air is 113eiu
/g and the deterioration rate is 12%, 30℃-90%RH-7
The as on day was 98 emu/g. These measurement results are shown in Tables 1 and 2 in comparison with the results of Example 1.
比較例 ４゜
還元後、トルエン中へ取出してトルエン中に空気を吹き
こみ酸化したこと以外は実施例１と同様のことをくり返
した。その結果は第２表に示す通りであった。Comparative Example The same procedure as in Example 1 was repeated except that after 4° reduction, the sample was taken out into toluene and oxidized by blowing air into the toluene. The results were as shown in Table 2.
比較例 ５゜
Ｈ２とＣＯ２の混合ガスによる粒子表面のＦｅ３Ｏ４化
を行なわずに、還元後室温まで冷却してその後Ｎ と空
気により徐々にＰ Ｏ２を増加して酸化安定化を行なっ
た以外は実施例１と同様のことをくり返した。その結果
は第２表に示す通りであった。Comparative example 5゜The particle surface was not converted to Fe3O4 using a mixed gas of H2 and CO2, except that it was cooled to room temperature after reduction, and then oxidation stabilization was performed by gradually increasing P O2 with N and air. The same procedure as in Example 1 was repeated. The results were as shown in Table 2.
第１図は本発明の方法で製造した金属磁性粉末の粒子構
造を示す３０，０００倍の電子顕微鏡写真である。
第２図は従来の方法で製造した金属磁性粉末の粒子構造
を示す３０．０００倍の電子顕微鏡写真である。
特許出願人 チタン工業株式会社FIG. 1 is a 30,000x electron micrograph showing the particle structure of the metal magnetic powder produced by the method of the present invention. FIG. 2 is an electron micrograph at a magnification of 30,000 times showing the particle structure of a metal magnetic powder produced by a conventional method. Patent applicant Titan Kogyo Co., Ltd.
Claims (3)
うちから選ばれた１種類もしくは２種類以上の元素を含
む変性針状酸化鉄を原料とし、該原料を、あらかじめ調
製したＳｉまたはＡｌの水酸化物のコロイド溶液と接触
させることによりＳｉまたはＡｇの水酸化物を表面に被
着させた針状酸化鉄をつくり、該被着針状酸化鉄を還元
することからなる磁気記録用金属磁性粉末の製造方法。(1) Use acicular iron oxide or modified acicular iron oxide containing one or more elements selected from Ni, Co, Zn, and Mn as a raw material, and use the raw material as a raw material with previously prepared Si or Al A metal for magnetic recording, which comprises making acicular iron oxide with Si or Ag hydroxide deposited on its surface by contacting it with a colloidal solution of hydroxide, and reducing the deposited acicular iron oxide. Method for manufacturing magnetic powder.
うちから選ばれた１種類もしくは２種類以上の元素を含
む変性針状酸化鉄を原料とし、該原料を、あらかじめ調
製したＳｉまたはＡｌの水酸化物のコロイド溶液と接触
させることによりＳｉまたはＡｌの水酸化物を表面に被
着させた針状酸化鉄をつくり、該被着針状酸化鉄を還元
してＦｅを主成分とする金属磁性粉末とし、該金属磁性
粉末を２００〜４５０℃の温度でＨ＿２とＣＯ＿２との
混合ガスに接触させて粉末粒子の表面を予備的に酸化処
理した後、処理後の粉末粒子を室温近傍で、不活性ガス
と空気との混合ガスに接触させ、該混合ガスの酸素分圧
（Ｐｏ＿２）を徐々に増加させることによって粉末粒子
を表面酸化により安定化させることからなる、磁気記録
用金属磁性粉末の製造方法。(2) Use acicular iron oxide or modified acicular iron oxide containing one or more elements selected from Ni, Co, Zn, and Mn as a raw material, and use the raw material as a material with pre-prepared Si or Al By contacting with a colloidal solution of hydroxide, acicular iron oxide with Si or Al hydroxide deposited on the surface is produced, and the deposited acicular iron oxide is reduced to make Fe the main component. The metal magnetic powder is brought into contact with a mixed gas of H_2 and CO_2 at a temperature of 200 to 450°C to preliminarily oxidize the surface of the powder particles, and then the treated powder particles are heated near room temperature. , a metal magnetic powder for magnetic recording, which consists of stabilizing the powder particles by surface oxidation by bringing them into contact with a mixed gas of an inert gas and air and gradually increasing the oxygen partial pressure (Po_2) of the mixed gas. manufacturing method.
金属磁性粉末を２００〜４５０℃の温度でＨ＿２とＣＯ
＿２との混合ガスに接触させて粉末粒子の表面を予備的
に酸化処理した後、処理後の粉末粒子を室温近傍で不活
性ガスと空気との混合ガスに接触させ、該混合ガスの酸
素分圧（Ｐｏ＿２）を徐々に増加させることによって粉
末粒子を表面酸化により安定化させることからなる、磁
気記録用金属磁性粉末の製造方法。(3) Metal magnetic powder mainly composed of Fe produced by reduction of iron oxide is heated with H_2 and CO at a temperature of 200 to 450℃.
After preliminary oxidation treatment of the surfaces of the powder particles by contacting them with a mixed gas of A method for producing metal magnetic powder for magnetic recording, comprising stabilizing powder particles by surface oxidation by gradually increasing pressure (Po_2).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63123306A JPH01294810A (en) | 1988-05-20 | 1988-05-20 | Production of magnetic metal powder for magnetic recording |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63123306A JPH01294810A (en) | 1988-05-20 | 1988-05-20 | Production of magnetic metal powder for magnetic recording |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01294810A true JPH01294810A (en) | 1989-11-28 |
| JPH0445561B2 JPH0445561B2 (en) | 1992-07-27 |
Family
ID=14857277
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63123306A Granted JPH01294810A (en) | 1988-05-20 | 1988-05-20 | Production of magnetic metal powder for magnetic recording |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01294810A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1440752A1 (en) | 2003-01-23 | 2004-07-28 | General Electric Company | Fabrication and utilization of metallic powder prepared without melting |
| US10100386B2 (en) | 2002-06-14 | 2018-10-16 | General Electric Company | Method for preparing a metallic article having an other additive constituent, without any melting |
| US10604452B2 (en) | 2004-11-12 | 2020-03-31 | General Electric Company | Article having a dispersion of ultrafine titanium boride particles in a titanium-base matrix |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58161705A (en) * | 1982-03-16 | 1983-09-26 | Hitachi Maxell Ltd | Production of magnetic metallic powder |
| JPS59107503A (en) * | 1982-12-13 | 1984-06-21 | Kanto Denka Kogyo Kk | Method of manufacturing magnetic powders with iron as main constituent for magnetic recording |
-
1988
- 1988-05-20 JP JP63123306A patent/JPH01294810A/en active Granted
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58161705A (en) * | 1982-03-16 | 1983-09-26 | Hitachi Maxell Ltd | Production of magnetic metallic powder |
| JPS59107503A (en) * | 1982-12-13 | 1984-06-21 | Kanto Denka Kogyo Kk | Method of manufacturing magnetic powders with iron as main constituent for magnetic recording |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10100386B2 (en) | 2002-06-14 | 2018-10-16 | General Electric Company | Method for preparing a metallic article having an other additive constituent, without any melting |
| EP1440752A1 (en) | 2003-01-23 | 2004-07-28 | General Electric Company | Fabrication and utilization of metallic powder prepared without melting |
| US6968990B2 (en) | 2003-01-23 | 2005-11-29 | General Electric Company | Fabrication and utilization of metallic powder prepared without melting |
| US10604452B2 (en) | 2004-11-12 | 2020-03-31 | General Electric Company | Article having a dispersion of ultrafine titanium boride particles in a titanium-base matrix |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0445561B2 (en) | 1992-07-27 |
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