JPH028303A - Manufacture of acicular metal magnetic granular powder containing iron as main component - Google Patents
Manufacture of acicular metal magnetic granular powder containing iron as main componentInfo
- Publication number
- JPH028303A JPH028303A JP4838788A JP4838788A JPH028303A JP H028303 A JPH028303 A JP H028303A JP 4838788 A JP4838788 A JP 4838788A JP 4838788 A JP4838788 A JP 4838788A JP H028303 A JPH028303 A JP H028303A
- Authority
- JP
- Japan
- Prior art keywords
- particles
- acicular
- metal magnetic
- grain
- main component
- 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
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 title claims abstract description 57
- 229910052751 metal Inorganic materials 0.000 title claims abstract description 29
- 239000002184 metal Substances 0.000 title claims abstract description 29
- 229910052742 iron Inorganic materials 0.000 title claims abstract description 27
- 238000004519 manufacturing process Methods 0.000 title claims description 9
- 239000000843 powder Substances 0.000 title abstract description 19
- 229910052595 hematite Inorganic materials 0.000 claims abstract description 29
- 239000011019 hematite Substances 0.000 claims abstract description 29
- LIKBJVNGSGBSGK-UHFFFAOYSA-N iron(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Fe+3].[Fe+3] LIKBJVNGSGBSGK-UHFFFAOYSA-N 0.000 claims abstract description 29
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims abstract description 16
- 229910052698 phosphorus Inorganic materials 0.000 claims abstract description 8
- 239000011574 phosphorus Substances 0.000 claims abstract description 8
- -1 phosphorus compound Chemical class 0.000 claims abstract description 8
- 238000010438 heat treatment Methods 0.000 claims abstract description 7
- 239000002245 particle Substances 0.000 claims description 140
- 239000007900 aqueous suspension Substances 0.000 claims description 31
- 239000006249 magnetic particle Substances 0.000 claims description 31
- 239000007864 aqueous solution Substances 0.000 claims description 16
- 238000010335 hydrothermal treatment Methods 0.000 claims description 7
- 229910003153 β-FeOOH Inorganic materials 0.000 claims description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 abstract description 15
- 238000006243 chemical reaction Methods 0.000 abstract description 7
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 abstract description 6
- 238000002156 mixing Methods 0.000 abstract 2
- VTLYFUHAOXGGBS-UHFFFAOYSA-N Fe3+ Chemical compound [Fe+3] VTLYFUHAOXGGBS-UHFFFAOYSA-N 0.000 abstract 1
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 abstract 1
- 239000002244 precipitate Substances 0.000 description 14
- 230000000052 comparative effect Effects 0.000 description 13
- 239000011148 porous material Substances 0.000 description 13
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 10
- 238000002441 X-ray diffraction Methods 0.000 description 8
- 238000000635 electron micrograph Methods 0.000 description 8
- 239000000203 mixture Substances 0.000 description 8
- 238000001035 drying Methods 0.000 description 7
- 238000001914 filtration Methods 0.000 description 7
- 238000000034 method Methods 0.000 description 7
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 6
- 239000007789 gas Substances 0.000 description 6
- 239000007858 starting material Substances 0.000 description 6
- 235000011007 phosphoric acid Nutrition 0.000 description 5
- 238000005406 washing Methods 0.000 description 5
- 239000013078 crystal Substances 0.000 description 4
- 230000005415 magnetization Effects 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 3
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 3
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- 229910052598 goethite Inorganic materials 0.000 description 3
- AEIXRCIKZIZYPM-UHFFFAOYSA-M hydroxy(oxo)iron Chemical class [O][Fe]O AEIXRCIKZIZYPM-UHFFFAOYSA-M 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- 239000000725 suspension Substances 0.000 description 3
- 206010034016 Paronychia Diseases 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 230000018044 dehydration Effects 0.000 description 2
- 238000006297 dehydration reaction Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000001493 electron microscopy Methods 0.000 description 2
- 229960002089 ferrous chloride Drugs 0.000 description 2
- 238000011049 filling Methods 0.000 description 2
- NMCUIPGRVMDVDB-UHFFFAOYSA-L iron dichloride Chemical compound Cl[Fe]Cl NMCUIPGRVMDVDB-UHFFFAOYSA-L 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 1
- 238000004438 BET method Methods 0.000 description 1
- 229910002588 FeOOH Inorganic materials 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- UEZVMMHDMIWARA-UHFFFAOYSA-N Metaphosphoric acid Chemical compound OP(=O)=O UEZVMMHDMIWARA-UHFFFAOYSA-N 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-N ammonia Natural products N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- XPPKVPWEQAFLFU-UHFFFAOYSA-N diphosphoric acid Chemical compound OP(O)(=O)OP(O)(O)=O XPPKVPWEQAFLFU-UHFFFAOYSA-N 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 230000003301 hydrolyzing effect Effects 0.000 description 1
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical compound [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 description 1
- 229910021506 iron(II) hydroxide Inorganic materials 0.000 description 1
- SZVJSHCCFOBDDC-UHFFFAOYSA-N iron(II,III) oxide Inorganic materials O=[Fe]O[Fe]O[Fe]=O SZVJSHCCFOBDDC-UHFFFAOYSA-N 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- NCNCGGDMXMBVIA-UHFFFAOYSA-L iron(ii) hydroxide Chemical compound [OH-].[OH-].[Fe+2] NCNCGGDMXMBVIA-UHFFFAOYSA-L 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000013528 metallic particle Substances 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- ACVYVLVWPXVTIT-UHFFFAOYSA-N phosphinic acid Chemical compound O[PH2]=O ACVYVLVWPXVTIT-UHFFFAOYSA-N 0.000 description 1
- 150000003018 phosphorus compounds Chemical class 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 229940005657 pyrophosphoric acid Drugs 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 239000012266 salt solution Substances 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- ISIJQEHRDSCQIU-UHFFFAOYSA-N tert-butyl 2,7-diazaspiro[4.5]decane-7-carboxylate Chemical compound C1N(C(=O)OC(C)(C)C)CCCC11CNCC1 ISIJQEHRDSCQIU-UHFFFAOYSA-N 0.000 description 1
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
本発明は、鉄を主成分とする針状金属磁性粒子粉末の製
造法、詳しくは、高密度記録用として好適である粒子表
面並びに粒子内部に空孔が存在しておらず、実質的に高
密度であって、且つ、粒度が均斉で樹枝状粒子が混在し
ていない鉄を主成分とする針状金属磁性粒子粉末の製造
法に関するものである。Detailed Description of the Invention [Industrial Field of Application] The present invention relates to a method for producing acicular metal magnetic particles containing iron as a main component, and more particularly, a method for producing acicular metal magnetic particles containing iron as a main component. A method for producing acicular metal magnetic particles whose main component is iron, which has no pores, has substantially high density, is uniform in particle size, and does not contain dendritic particles. It is.
近年、磁気記録再生用機器の長時間記録化、小型軽量化
が進むにつれて、磁気記録媒体の高性能化、高密度記録
化の要求が高まってきている。BACKGROUND ART In recent years, as magnetic recording and reproducing equipment has become longer recording time and has become smaller and lighter, demands for higher performance and higher density recording of magnetic recording media have been increasing.
磁気記録媒体の上記の要求を満足させる為に適した磁性
粒子粉末の特性は、大きな飽和磁化σＳを有し、且つ、
磁性粒子粉末のビークル中での分散性、塗膜中での配向
性及び充填性が優れていることである。The characteristics of magnetic particles suitable for satisfying the above requirements of magnetic recording media include having a large saturation magnetization σS, and
The magnetic particles have excellent dispersibility in a vehicle, orientation in a coating film, and filling properties.
そして、ビークル中での分散性、塗膜中での配向性及び
充填性を向上させるためには、ビークル中に分散させる
磁性粒子粉末の粒子表面並びに粒子内部に空孔が存在し
ておらず実質的に高密度であって、且つ、粒度が均斉で
樹枝状粒子が混在していない粒子が要求される。In order to improve the dispersibility in the vehicle, the orientation and filling properties in the coating film, it is necessary that the magnetic particles dispersed in the vehicle have no pores on the surface or inside the particles. Particles are required to have high density, uniform particle size, and no dendritic particles.
現在、磁気記録用磁性粒子粉末として主に針状晶マグネ
タイト粒子粉末または、針状晶マグヘマイト粒子粉末が
用いられているが、近年、磁気記録媒体の高性能化に伴
い、これらの磁性酸化鉄粒子に比べ、大きな飽和磁化σ
Ｓを有する鉄を主成分とする針状金属磁性粒子粉末が注
目を浴びており、該粒子の特性向上が強く要求されてい
る。これらは一般に、第一鉄塩水溶液とアルカリとを反
応させて得られる水酸化第一鉄粒子を含むｐＨ１１以上
のコロイド水溶液を空気酸化しく通常、「湿式反応」と
呼ばれている。）で得られる針状α−ＦｅｏｏＨ粒子を
、空気中３００℃付近で加熱、脱水してヘマタイト粒子
となし、更に、水素等還元性ガス中３００〜４００℃で
還元することにより得られている。Currently, acicular magnetite particles or acicular maghemite particles are mainly used as magnetic particles for magnetic recording, but in recent years, with the improvement of the performance of magnetic recording media, these magnetic iron oxide particles Large saturation magnetization σ compared to
Acicular metal magnetic particles containing S as a main component have been attracting attention, and there is a strong demand for improving the characteristics of the particles. These reactions are generally referred to as "wet reactions" in which an aqueous colloidal solution containing ferrous hydroxide particles and having a pH of 11 or more, which is obtained by reacting an aqueous ferrous salt solution with an alkali, is oxidized with air. ) are heated and dehydrated in air at around 300°C to form hematite particles, and further reduced at 300 to 400°C in a reducing gas such as hydrogen.
〔発明が解決しようとする問題点］
粒子表面並びに粒子内部に空孔が存在しておらず実質的
に高密度であって、且つ、粒度が均斉で樹枝状粒子が混
在していない鉄を主成分とする針状金属磁性粒子粉末は
、現在量も要求されているところであるが、出発原料で
ある針状ケータイト粒子を製造する前述の公知方法によ
り得られた粒子粉末は、樹枝状粒子が混在しており、ま
た粒度から言えば、均斉な粒度を有した粒子であるとは
言い難く、該針状ゲータイト粒子を出発原料として用い
、還元して得られた鉄を主成分とする針状金属磁性粒子
粉末もまた、樹枝状粒子が混在しており、また粒度から
言えば、均斉な粒度を有した粒子であるとは言い難いも
のである。[Problems to be solved by the invention] Mainly made of iron, which has no pores on the surface or inside the particles, has a substantially high density, has a uniform particle size, and does not contain dendritic particles. The amount of acicular metal magnetic particles as a component is currently required, but the particles obtained by the above-mentioned known method for producing acicular ketite particles as a starting material have dendritic particles. In addition, considering the particle size, it is difficult to say that the particles have a uniform particle size. Metal magnetic particles also contain dendritic particles, and in terms of particle size, it is difficult to say that the particles have a uniform particle size.
また、このゲータイト粒子粉末を出発原料として常法に
より鉄を主成分とする針状金属磁性粒子粉末を得た場合
、ゲータイト粒子を加熱脱水して得られるヘマタイト粒
子は脱水により、粒子表面並びに粒子内部に多数の空孔
を生じ、次いで、該ヘマタイト粒子を還元して得られる
鉄を主成分とする針状金属磁性粒子もまた粒子表面並び
に粒子内部に多数の空孔が分布していることが観察され
る。In addition, when obtaining acicular metal magnetic particles containing iron as a main component using this goethite particle powder as a starting material by a conventional method, the hematite particles obtained by heating and dehydrating the goethite particles will be dehydrated on the particle surface and inside the particle. It was observed that the acicular metal magnetic particles containing iron as a main component obtained by reducing the hematite particles also had a large number of pores distributed on the particle surface and inside the particles. be done.
ごのように、粒子表面並びに粒子内部に多数の空孔を有
する鉄を主成分とする針状金属磁性粒子粉末は、ビーク
ル中での分散が悪いものである。As shown in FIG. 2, acicular metal magnetic particles whose main component is iron and which have a large number of pores on the particle surface and inside the particles have poor dispersion in a vehicle.
従来、粒子表面並びに粒子内部に空孔のない鉄を主成分
とする針状金属磁性粒子粉末を得る方法が試のられてい
る。Conventionally, methods have been tried to obtain acicular metal magnetic particles whose main component is iron and which have no pores on the surface or inside the particles.
この方法は、水溶液中から直接針状晶へマクイト粒子を
生成さ−せ、該針状晶へマクイト粒子を出発原料として
還元することにより鉄を主成分とする針状金属磁性粒子
を得る方法である。In this method, maquito particles are generated directly into needle crystals from an aqueous solution, and then the maquito particles are reduced to the needle crystals as a starting material to obtain acicular metal magnetic particles containing iron as the main component. be.
即ち、粒子表面並びに粒子内部の空孔は、前述した通り
、針状晶ゲータイト粒子を加熱脱水して針状晶へマクイ
ト粒子とする際の脱水により発生ずるものであるから、
水溶液中から直接３１状品へマクイトを生成させれば、
脱水工程を省略することができ、従って、粒子表面並び
に粒子内部に空孔の全くない針状晶へマクイト粒子を得
ることができ、該ヘマタイト粒子を出発原料として還元
して得られた鉄を主成分とする針状金属磁性粒子もまた
粒子表面並びに粒子内部に空孔が全くないものとなる。That is, as mentioned above, the pores on the particle surface and inside the particles are generated by dehydration when acicular goethite particles are heated and dehydrated to convert them into acicular crystals into maquito particles.
If maquito is produced directly from an aqueous solution into a 31-like product,
The dehydration step can be omitted, and therefore maquito particles can be obtained into acicular crystals with no pores on the particle surface or inside the particles, and iron obtained by reducing the hematite particles as a starting material can be used as the main material. The acicular metal magnetic particles as a component also have no pores on the particle surface or inside the particle.
上述したところから明らかな通り、粒子表面並びに粒子
内部に空孔が全く存在しておらず実質的に高密度であっ
て、且つ、粒子が均斉で樹枝状粒子が混在していない鉄
を主成分とする針状金属磁性粒子粉末を得る為には、粒
子が均斉で樹枝状粒子が混在していない針状ヘマタイト
粒子を水溶液中から直接生成させる方法が強く要望され
ζいるのである。As is clear from the above, the particles have substantially no pores on the surface or inside the particles, have a substantially high density, are uniform in size, and are mainly composed of iron with no dendritic particles mixed in. In order to obtain the acicular metal magnetic particle powder, there is a strong demand for a method of directly producing acicular hematite particles from an aqueous solution, which have uniform particles and do not contain dendritic particles.
本発明者は、粒度が均斉で樹枝状粒子が混在していない
針状ヘマタイト粒子を水溶液中から直接生成させる方法
について種々検討を重ねた結果、本発明に到達したので
ある。The present inventor has arrived at the present invention as a result of various studies on a method for directly producing acicular hematite particles having a uniform particle size and no dendritic particles mixed therein from an aqueous solution.
即ち、本発明は、β−ＦｅＯＯｔｌを含む水懸濁液にア
ルカリ性水溶液を添加してｐＨ８以上の水性懸濁液とし
、次いで、該水性懸濁液に塩酸を添加して得られた前記
β−ＦｅＯＯＨを含むｐＨ７以下の水性懸濁液に、当該
懸濁液中のＦｅ（２）に対しＰ換算で０．１〜２．０原
子％のリン化合物を添加した後、１００〜１３０″Ｃの
温度範囲で水熱処理することにより、針状ヘマタイト粒
子を生成させ、該針状へマクイト粒子を還元性ガス中で
加熱還元して鉄を主成分とする針状金属磁性粒子とする
ことよりなる鉄を主成分とする針状金属磁性粒子粉末の
製造法である。That is, in the present invention, an alkaline aqueous solution is added to an aqueous suspension containing β-FeOOtl to obtain an aqueous suspension having a pH of 8 or more, and then hydrochloric acid is added to the aqueous suspension to obtain the β-FeOOtl-containing aqueous suspension. After adding a phosphorus compound of 0.1 to 2.0 atomic % in terms of P to Fe(2) in the suspension to an aqueous suspension containing FeOOH with a pH of 7 or less, Acicular hematite particles are generated by hydrothermal treatment in a temperature range, and the acicular maquite particles are heated and reduced in a reducing gas to produce acicular metal magnetic particles containing iron as the main component. This is a method for producing acicular metal magnetic particle powder containing as a main component.
先ず、本発明において最も重要な点は、β−Ｆｅ００Ｈ
を含む水懸濁液にアルカリ性水溶液を添加して１１１８
以上の水性懸濁液とし、次いで、該水性懸濁液に塩酸を
添加して得られた前記β−Ｐ ｅ ＯＯｔ＋を含むｐ１
１７以下の水性懸濁液に、当該懸濁液中のＦｅ（２）に
対しＰ換算で０．１〜２．０以十％のリン化合物を添加
した後、１００〜１３０℃の温度範囲で水熱処理した場
合には、粒子内部に空孔が存在しておらず、実質的に高
密度であって、且つ、粒度が均斉で樹枝状粒子が混在し
ていない針状ヘマタイト粒子を水溶液中から直接生成さ
せることができ、該針状へマクイト粒子を加熱還元して
得られる鉄を主成分点する針状金属磁性粒子もまた、出
発原料である針状ヘマタイト粒子の粒子形状を保持継承
していることによって、粒子内部に空孔が存在しておら
ず、実質的に高密度であって、且つ、粒度が均斉で樹枝
状粒子が混在していない鉄を主成分とする針状金属磁性
粒子であるという事実である。First, the most important point in the present invention is that β-Fe00H
1118 by adding an alkaline aqueous solution to an aqueous suspension containing
The above aqueous suspension was obtained, and then hydrochloric acid was added to the aqueous suspension to obtain p1 containing the β-P e OOt+.
After adding a phosphorus compound of 0.1 to 2.0 or more in terms of P to Fe(2) in the suspension to an aqueous suspension of 17 or less, the temperature range is 100 to 130 ° C. When subjected to hydrothermal treatment, acicular hematite particles with no pores inside the particles, substantially high density, uniform particle size, and no dendritic particles are extracted from an aqueous solution. The acicular metal magnetic particles, which can be produced directly and whose main component is iron, obtained by thermally reducing maquito particles into acicular shapes, also retain and inherit the particle shape of the acicular hematite particles that are the starting material. As a result, there are no pores inside the particles, the particles are substantially dense, and the particle size is uniform and there are no dendritic particles mixed in. Acicular metal magnetic particles mainly composed of iron The fact is that
本発明において針状へマクイト粒子が生成する理由につ
いて、本発明者は、後出の比較例に示す通り、リン化合
物を添加しない場合には、等方的なヘマタイト粒子が生
成することから、リン化合物が生成するヘマタイト粒子
の粒子形態に関与しているものと考えている。As for the reason why acicular hematite particles are produced in the present invention, the present inventors believe that isotropic hematite particles are produced when no phosphorus compound is added, as shown in the comparative example below. We believe that the compound is involved in the particle morphology of the hematite particles produced.
本発明においては、１１１８以上の水性懸濁液をｐｕ７
以下の水性懸濁液とする為に使用する酸として塩酸を使
用した場合には、ヘマタイト粒子を生成させることがで
きるが、塩酸以外の酸、例えば、硫酸、酢酸、燐酸等を
使用する場合にはへマクイト粒子を生成させることがで
きない。In the present invention, an aqueous suspension of pu7
When hydrochloric acid is used as the acid used to form the aqueous suspension described below, hematite particles can be generated, but when using acids other than hydrochloric acid, such as sulfuric acid, acetic acid, phosphoric acid, etc. It is not possible to generate Hahemakite particles.
次に、本発明実施にあたっての諸条件について述べる。Next, various conditions for implementing the present invention will be described.
本発明においては、鉄原料としてβ−ＦｅＯＯＨを使用
することが必要である。β−Ｆｅ００１１は、塩化第一
鉄水溶液を加熱処理して加水分解する方法、塩化第−鉄
水溶液に酸素含有ガスを通気して酸化反応を行う方法等
により得ることができ、不定形、針状、紡錘状等いかな
る粒子形態のものでも使用することができる。In the present invention, it is necessary to use β-FeOOH as the iron raw material. β-Fe0011 can be obtained by a method of heating and hydrolyzing a ferrous chloride aqueous solution, a method of conducting an oxidation reaction by passing an oxygen-containing gas through a ferrous chloride aqueous solution, etc. , spindle-shaped, etc. particles can be used.
本発明において、β−Ｆｅｌｏｎを含む水懸濁液のｐＨ
は高々６．０程度であり、当該水懸濁液にアルカリ性水
溶液を添加することによりｐＨ８以上とする。In the present invention, the pH of the aqueous suspension containing β-Felon
is about 6.0 at most, and the pH is adjusted to 8 or higher by adding an alkaline aqueous solution to the aqueous suspension.
本発明におけるアルカリ性水溶液としては、水酸化ナト
リウム、水酸化カリウＪ・、アンモニア水等を使用する
ことができる。アルカリ性水溶液添加後の水性懸濁液の
ｐｌ＋が８以下の場合には、ヘマタイトとβ−Ｆｅ００
１１の混合物が生成する。As the alkaline aqueous solution in the present invention, sodium hydroxide, potassium hydroxide, aqueous ammonia, etc. can be used. If the pl+ of the aqueous suspension after addition of the alkaline aqueous solution is 8 or less, hematite and β-Fe00
A mixture of 11 is produced.
本発明において、１１１８以上の水性懸濁液をＰＩ＋７
以下の水性懸濁液にする為には、塩酸を使用することが
必要である。塩酸添加後の水性懸濁液のｐＨが７以十で
ある場合には、１００〜＋３０“Ｃの温度領域において
はβ−ＦｅＯＯＨが安定して生成する為へマクイト粒子
が生成しない。In the present invention, an aqueous suspension with a PI+7 of 1118 or more is used.
To make the following aqueous suspension it is necessary to use hydrochloric acid. When the pH of the aqueous suspension after addition of hydrochloric acid is 7 or more, maquito particles are not produced because β-FeOOH is stably produced in the temperature range of 100 to +30"C.
本発明においては、β−ＦｅＯＯＨを含む水懸濁液の濃
度が１．０ ｍｏｌ／４２程度の高濃度であってもヘマ
タイト粒子を生成することが可能である。１．０ ｍｏ
ｌ／１以上の場合にもヘマタイト粒子は生成するが、粒
度が不均斉となる。In the present invention, it is possible to produce hematite particles even if the concentration of the aqueous suspension containing β-FeOOH is as high as about 1.0 mol/42. 1.0 mo
Although hematite particles are generated when the ratio is 1/1 or more, the particle size becomes asymmetric.
本発明におけるリン化合物としては、メタリン酸、次亜
リン酸、亜リン酸、正リン酸、ピロリン酸及びこれ等の
塩等無機のリン化合物を用いることができる。As the phosphorus compound in the present invention, inorganic phosphorus compounds such as metaphosphoric acid, hypophosphorous acid, phosphorous acid, orthophosphoric acid, pyrophosphoric acid, and salts thereof can be used.
リン化合物の添加量は、懸濁液中のＦｅ（至）に対し、
■）換算で０．１〜２．０以十％である。０．１以十％
以下である場合には、本発明の目的とする針状ヘマタイ
ト粒子を得ることができない。２．０以十％以卜である
場合にも、針状ヘマタイトが生成するが、反応に長時間
を要する。The amount of the phosphorus compound added is as follows:
(2) It is 0.1 to 2.0 or more in terms of conversion. 0.1 or more 10%
In the following cases, the acicular hematite particles targeted by the present invention cannot be obtained. Acicular hematite is produced when the content is 2.0 or more, but the reaction takes a long time.
本発明における反応温度は、１００〜１３０℃である。The reaction temperature in the present invention is 100 to 130°C.
】００℃以下である場合には、β−Ｆｅｌｏｎの溶解が
十分に進行しない為へマクイト粒子が生成しない。If the temperature is below 00°C, the dissolution of β-Felon will not proceed sufficiently, and maquito particles will not be formed.
１３０℃以Ｊ−である場合にもヘマタイト粒子は生成す
るが、高圧容器等特殊な装置を必要とする為、工業的、
経済的ではない。Hematite particles can also be produced when the temperature is 130°C or higher, but this requires special equipment such as a high-pressure container, so it cannot be used industrially.
It's not economical.
本発明における還元性ガス中における加熱還元処理は常
法により行うことができる。The heating reduction treatment in a reducing gas in the present invention can be carried out by a conventional method.
また、出発原料であるヘマタイト粒子は、加熱処理に先
立って通常行われるＳｉ、 ＡＩ、 Ｐ化合物等の焼結
防止効果を有する物質によってあらかし７め被覆処理し
ておくごとにより、より分散性の優れた鉄を主成分とす
る針状金属磁性粒子粉末を得ることができる。In addition, the hematite particles, which are the starting material, are coated with a substance that has a sintering prevention effect, such as Si, AI, or P compounds, which is usually carried out prior to heat treatment, to improve their dispersibility. It is possible to obtain acicular metal magnetic particles having excellent iron as a main component.
次に、実施例並びに比較例により本発明を説明する。 Next, the present invention will be explained with reference to Examples and Comparative Examples.
尚、以下の実施例における粒子の平均径は、電子８Ｊｉ
微鏡写真から測定した数値の平均値であり、比表面積は
ＢＥＴ法により測定した値である。In addition, the average diameter of particles in the following examples is electron 8Ji
This is the average value of numerical values measured from microscopic photographs, and the specific surface area is a value measured by the BET method.
実施例１
Ｏ，４ｍｏｌ／ｊ２のβ−Ｆｅ００１１粒子（比表面積
５８ｒ＋？／ｇ）を含むｐｌ＋５．５の水懸濁液５００
ｍ ｌにＮａ０１１水溶液を添加してｐＨ９，０の水性
懸濁液を得た。Example 1 500 pl+5.5 aqueous suspension containing β-Fe0011 particles (specific surface area 58r+?/g) of O,4 mol/j2
An aqueous Na011 solution was added to ml to obtain an aqueous suspension with a pH of 9.0.
Ｌ配水性懸濁液にＩＩｃＩＩｃ法を添加して得られたβ
−ＦｅＯＯｔ１粒子を含むｐＨ２，０の水性懸濁液に、
正リン酸０．２０ｇ （Ｆｅｆ面に対しＰ換算で１．０
原子％に該当する。）を添加した後、密閉容器中Ｃに入
れ、１２５℃で１５時間水熱処理し−ζ赤褐色沈澱を生
成させた。赤褐色沈澱を水洗、ｔｐ過、乾燥して得られ
た粒子粉末は、図１に示すＸ線回折に示す通り、ヘマタ
イトであり、図２に示す電子顕微鏡写真（Ｘ ２０ 、
０００）から明らかな通り、平均粒子径が０．８μｍで
ある実質的に高密度な針状粒子であり、粒度が均斉で樹
枝状粒子が混在しておらす、且つ、個々の粒子が独立し
た粒子であった。β obtained by adding IIcIIc method to L water distribution suspension
- an aqueous suspension at pH 2.0 containing 1 particles of FeOOt;
Orthophosphoric acid 0.20g (1.0 in P conversion for FEF surface)
Corresponds to atomic percent. ), the mixture was placed in C in a closed container and hydrothermally treated at 125°C for 15 hours to form a -ζ reddish brown precipitate. The particles obtained by washing the reddish brown precipitate with water, TP filtration, and drying were hematite as shown in the X-ray diffraction shown in FIG. 1, and the electron micrograph (X 20 ,
000), it is a substantially dense acicular particle with an average particle diameter of 0.8 μm, the particle size is uniform, dendritic particles are mixed, and each particle is independent. It was a particle.
１−記へマクイト粒子粉末７０ｇを１！のレトルト還元
容器中に投入し、駆動回転さセなから１１゜ガスを毎分
１！の割合で通気し、還元温度３５０℃で還元した。1-70g of Makuito particle powder to 1! into the retort reducing container, and from the drive rotating mechanism, 11° gas is supplied at 1 minute per minute! The mixture was aerated at a rate of 350° C. and reduced at a reduction temperature of 350°C.
還元して得られた鉄を主成分とする金属磁性粒子粉末は
、空気中に取り出した時、急激な酸化を起こさないよう
に、−旦、トルエン液中に浸漬して、これを蒸発させる
ことにより、粒子表面に安定な酸化被膜を施した。To prevent rapid oxidation from occurring when the metal magnetic particle powder containing iron as the main component obtained through reduction is taken out into the air, it must first be immersed in a toluene solution to evaporate it. A stable oxide film was formed on the particle surface.
得られた鉄を主成分とする金属磁性粒子粉末は、電子顕
微鏡観察の結果、平均粒子径が０．７μｍである実質的
に高密度な針状粒子であり、粒度が均斉で樹枝状粒子が
混在しておらず、且つ、個々の粒子が独立した粒子であ
った。また、磁気測定の結果、保磁力Ｈｅは４７１０ｅ
、飽和磁化σｓは１１８．５ｅｍｕ／ｇであった。As a result of electron microscopy, the obtained metal magnetic particles containing iron as a main component were found to be substantially dense acicular particles with an average particle size of 0.7 μm, with uniform particle size and dendritic particles. They were not mixed and each particle was an independent particle. In addition, as a result of magnetic measurement, the coercive force He was 4710e
, the saturation magnetization σs was 118.5 emu/g.
実施例２
０．５ ｍｏｌ／ｊ２のβ−Ｆｅ００８粒子（比表面積
１１０ ｒｆ／ｇ）を含むｐ＋＋ｓ、ｏの水懸濁液５０
０ｍ Ｉ！にＮＨ４０１１水溶液を添加してｐＨ８，５
の水性懸濁液を得た。Example 2 Aqueous suspension 50 of p++s, o containing 0.5 mol/j2 β-Fe008 particles (specific surface area 110 rf/g)
0m I! Add NH4011 aqueous solution to pH 8.5
An aqueous suspension of was obtained.
−ヒ記水性懸濁液にＩＩｃＩ水溶液を添加して得られた
β−Ｆｅ００８粒子を含むｐＨ，５の水性懸濁液に、正
リン酸０．１２５ｇ （Ｆｅ（２）に対しＰ換算で０．
５原子％に該当する。）を添加した後、密閉容器中に入
れ、１２５℃で１５時間水熱処理して赤褐色沈澱を生成
させた。赤褐色沈澱を水洗、濾過、乾燥して得られた粒
子粉末は、Ｘ線回折の結果へマクイトであり、図３に示
す電子顕微鏡写真（ｘ ２０．０００）から明らかな通
り、平均粒子径が０．５μｍである実質的に高密度な針
状粒子であり、粒度が均斉で樹枝状粒子が混在しておら
ず、且つ、個々の粒子が独立した粒子であった。- 0.125 g of orthophosphoric acid (0.125 g in terms of P for Fe(2) ．．
This corresponds to 5 atom%. ), the mixture was placed in a closed container and hydrothermally treated at 125° C. for 15 hours to form a reddish-brown precipitate. The particles obtained by washing the reddish brown precipitate with water, filtration, and drying were determined by X-ray diffraction, and as is clear from the electron micrograph (x 20,000) shown in Figure 3, the average particle size was 0. The particles were acicular particles with a substantially high density of .5 μm, uniform particle size, no dendritic particles mixed together, and each particle was an independent particle.
上記へマクイト粒子粉末７０ｇを１１のレトルト還元容
器中に投入し、駆動回転させなからＨ２ガスを毎分ＩＩ
！の割合で通気し、還元温度３５０℃で還元した。To the above, 70 g of Makito particle powder was put into the retort reduction container No. 11, and while driving and rotating, H2 gas was supplied every minute.
! The mixture was aerated at a rate of 350° C. and reduced at a reduction temperature of 350°C.
還元して得られた鉄を主成分とする金属磁性粒子粉末は
、空気中に取り出した時、急激な酸化を起こさないよう
に、−旦、トルエン液中に浸漬して、これを蒸発させる
ことにより、粒子表面に安定な酸化被膜を施した。To prevent rapid oxidation from occurring when the metal magnetic particle powder containing iron as the main component obtained through reduction is taken out into the air, it must first be immersed in a toluene solution to evaporate it. A stable oxide film was formed on the particle surface.
得られた鉄を主成分とする金属磁性粒子粉末は、電子顕
微鏡観察の結果、平均粒子径が０．４μｍである実質的
に高密度な針状粒子であり、粒度が均斉で樹枝状粒子が
混在しておらず、且つ、個々の粒子が独立した粒子であ
った。また、磁気測定の結果、保磁力Ｈｃは４６３０ｅ
、飽和磁化ｏｓは１７１３．２ｅｍｕ７ｇであった。As a result of electron microscopy, the obtained metal magnetic particles containing iron as a main component were found to be substantially dense acicular particles with an average particle size of 0.4 μm, with uniform particle size and dendritic particles. They were not mixed and each particle was an independent particle. In addition, as a result of magnetic measurement, the coercive force Hc is 4630e
, the saturation magnetization OS was 1713.2 emu7g.
比較例１
正リン酸を添加しなかった以外は、実施例１と同様に水
熱処理して赤褐色沈澱を生成させた。Comparative Example 1 A reddish-brown precipitate was produced by hydrothermal treatment in the same manner as in Example 1, except that orthophosphoric acid was not added.
赤褐色沈澱を水洗、濾過、乾燥して得られた粒子粉末は
、図４に示すＸ線回折及び図５に示す電子顕微鏡写真（
ｘ２０，０００）から明らかな通り、平均粒径が０．３
μｍの等方的粒子であった。The particles obtained by washing the reddish-brown precipitate with water, filtration, and drying showed the X-ray diffraction shown in Figure 4 and the electron micrograph shown in Figure 5 (
x20,000), the average particle size is 0.3
They were isotropic particles of μm.
比較例２
０．２ ｍｏｌ／ｊ２のβ−Ｆ ｅ ＯＯｆｔ粒子（比
表面積１８０ ｒｒｒ／ｇ）を含むｐＨ１，７の水懸濁
液５００ｍ ｌをＮａ０１１水？６ ？Ｐｉ及び１１Ｃ
１水溶液を用いてｐＨ調整することなく、そのまま密閉
容器中に入れ、実施例１と同様に水熱処理して黄褐色沈
澱を生成させた。Comparative Example 2 500 ml of an aqueous suspension at pH 1.7 containing 0.2 mol/j2 β-F e OOft particles (specific surface area 180 rrr/g) was mixed with Na011 water? 6? Pi and 11C
1 without adjusting the pH using an aqueous solution, the mixture was placed in a closed container as it was, and subjected to hydrothermal treatment in the same manner as in Example 1 to produce a yellow brown precipitate.
黄褐色沈澱を水洗、濾過、乾燥して得られた粒子粉末は
、Ｘ線回折の結果及び図６に示す電子顕微鏡写真（Ｘ２
０．０００）から明らかな通り、β−Ｆｅ００１１のま
まであった。The particles obtained by washing the yellowish brown precipitate with water, filtering and drying are shown in the results of X-ray diffraction and in the electron micrograph (X2
0.000), it remained β-Fe0011.
比較例３
ＮａＯ１ｌ水溶液を添加してｐｌ＋ ６．８の水性懸濁
液とした以外は実施例１と同様に水熱処理して茶褐色沈
澱を生成させた。茶褐色沈澱を水洗、濾過、乾燥して得
られた粒子粉末は、Ｘ線回折の結果及び図７の電子顕微
鏡写真（ｘ ２０．０００）から明らがな通り、β−Ｐ
ｅＯＯＨとへマクイトの混合物であった。Comparative Example 3 A brown precipitate was produced by hydrothermal treatment in the same manner as in Example 1, except that an aqueous suspension of 1 L of NaO was added to obtain an aqueous suspension with a pl+ of 6.8. As is clear from the X-ray diffraction results and the electron micrograph (x 20,000) in Figure 7, the particles obtained by washing the brown precipitate with water, filtering, and drying are β-P.
It was a mixture of eOOH and hemaquite.
比較例４
＋１ｃＩ水溶液を添加してβ−ＦｅＯＯＨを含むｐＨ７
，５の水性懸濁液よした以外は、実施例１と同様に水熱
処理して黄褐色沈澱を生成させた。黄褐色沈澱を水洗、
濾過、乾燥して得られた粒子粉末は、Ｘ線回折の結果及
び図８に示す電子顕微鏡写真（ｘ５０゜０００）から明
らかな通り、β−Ｆｅ００１１のままであった。Comparative Example 4 pH 7 containing β-FeOOH by adding +1cI aqueous solution
, 5 was hydrothermally treated in the same manner as in Example 1, except that the aqueous suspension of No. 5 was used to form a yellow brown precipitate. Wash the yellowish brown precipitate with water.
The particles obtained by filtration and drying remained β-Fe0011, as is clear from the X-ray diffraction results and the electron micrograph (x50°000) shown in FIG.
比較例５
水熱処理の温度を９５゛Ｃとした以外は、実施例１と同
様にして黄褐色沈澱を生成させた。黄褐色沈澱を水洗、
濾過、乾燥して得られた粒子粉末は、図９に示すＸ線回
折及び図１０Ｌ：示す電子顕微鏡写真（ｘ ５０ 、０
００）から明らかな通り、β−ＦｅＯＯＨのままであっ
た。Comparative Example 5 A yellow brown precipitate was produced in the same manner as in Example 1, except that the temperature of the hydrothermal treatment was 95°C. Wash the yellowish brown precipitate with water.
The particles obtained by filtration and drying were subjected to X-ray diffraction as shown in FIG. 9 and an electron micrograph (x 50 , 0
00), it remained β-FeOOH.
〔発明の効果］
本発明における鉄を主成分とする針状金属磁性粒子粉末
の製造法によれば、前出実施例に示した通り、粒子表面
並びに粒子内部に空孔が存在しておらず実質的に高密度
であって、且つ、粒度が均斉で樹枝状粒子が混在してい
ない鉄を主成分とするｉ１状金金属性粒子からなる鉄を
主成分とする針状金属磁性粒子粉末を得るごとができる
ので、高性能、高密度記録用磁性粒子粉末として好適な
ものである。[Effects of the Invention] According to the method for producing acicular metal magnetic particles containing iron as a main component according to the present invention, as shown in the previous example, there are no pores on the particle surface or inside the particles. Iron-based acicular metal magnetic particle powder consisting of iron-based i1-shaped gold metallic particles that have substantially high density, are uniform in particle size, and do not contain dendritic particles. Therefore, it is suitable as a magnetic particle powder for high-performance, high-density recording.
図１、図４及び図９はいずれもＸ線回折図であり、図１
は実施例１で得られたヘマタイト粒子粉末、図４は、比
較例１で得られたヘマタイト粒子粉末、図９は比較例５
で得られたβ−ＦｅＯＯＩＩ粒子粉末である。
図２、図３、図５乃至図８及び図１０は、いずれも電子
顕微鏡写真であり、図２、図３及び図５１ｕｌｌそれぞ
れ、実施例１、実施例２及び比較例１で得られた針状ヘ
マタイト粒子粉末、図６、図８及び図１０はそれぞれ、
比較例２、比較例４及び比較例５で得られたβ−Ｆｅ０
０Ｈ粒子粉末、図７は、ヘマタイトとβ−Ｆｅ００１１
との混合物粒子粉末である。Figures 1, 4, and 9 are all X-ray diffraction diagrams, and Figure 1
4 is the hematite particle powder obtained in Example 1, FIG. 4 is the hematite particle powder obtained in Comparative Example 1, and FIG. 9 is the hematite particle powder obtained in Comparative Example 5.
This is β-FeOOII particle powder obtained in . Figures 2, 3, 5 to 8, and 10 are electron micrographs, and the needles obtained in Example 1, Example 2, and Comparative Example 1 are shown in Figures 2, 3, and 51ull, respectively. 6, 8 and 10, respectively,
β-Fe0 obtained in Comparative Example 2, Comparative Example 4, and Comparative Example 5
0H particle powder, Figure 7 shows hematite and β-Fe0011
It is a mixture of particles and powder.
Claims (1)
液を添加してｐＨ８以上の水性懸濁液とし、次いで、該
水性懸濁液に塩酸を添加して得られた前記β−ＦｅＯＯ
Ｈを含むｐＨ７以下の水性懸濁液に、当該懸濁液中のＦ
ｅ（III）に対しＰ換算で０．１〜２．０原子％のリン
化合物を添加した後、１００〜１３０℃の温度範囲で水
熱処理することにより、針状ヘマタイト粒子を生成させ
、該針状ヘマタイト粒子を還元性ガス中で加熱還元して
鉄を主成分とする針状金属磁性粒子とすることを特徴と
する鉄を主成分とする針状金属磁性粒子粉末の製造法。(1) The β-FeOOH obtained by adding an alkaline aqueous solution to an aqueous suspension containing β-FeOOH to obtain an aqueous suspension with a pH of 8 or higher, and then adding hydrochloric acid to the aqueous suspension.
In an aqueous suspension containing H and having a pH of 7 or less,
After adding 0.1 to 2.0 atom % of a phosphorus compound in terms of P to e(III), hydrothermal treatment is performed in a temperature range of 100 to 130°C to generate acicular hematite particles. 1. A method for producing acicular metal magnetic particles containing iron as a main component, which comprises heating and reducing hematite particles in a reducing gas to obtain acicular metal magnetic particles containing iron as a main component.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4838788A JPH028303A (en) | 1988-02-29 | 1988-02-29 | Manufacture of acicular metal magnetic granular powder containing iron as main component |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4838788A JPH028303A (en) | 1988-02-29 | 1988-02-29 | Manufacture of acicular metal magnetic granular powder containing iron as main component |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH028303A true JPH028303A (en) | 1990-01-11 |
Family
ID=12801892
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4838788A Pending JPH028303A (en) | 1988-02-29 | 1988-02-29 | Manufacture of acicular metal magnetic granular powder containing iron as main component |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH028303A (en) |
-
1988
- 1988-02-29 JP JP4838788A patent/JPH028303A/en active Pending
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