JPH01261804A - Manufacture of magnetic hexagonal-cobalt powder - Google Patents
Manufacture of magnetic hexagonal-cobalt powderInfo
- Publication number
- JPH01261804A JPH01261804A JP63089252A JP8925288A JPH01261804A JP H01261804 A JPH01261804 A JP H01261804A JP 63089252 A JP63089252 A JP 63089252A JP 8925288 A JP8925288 A JP 8925288A JP H01261804 A JPH01261804 A JP H01261804A
- Authority
- JP
- Japan
- Prior art keywords
- cobalt
- hexagonal
- hydrogen
- reaction
- water
- 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
- 238000004519 manufacturing process Methods 0.000 title claims description 18
- 229910017052 cobalt Inorganic materials 0.000 claims abstract description 53
- 239000010941 cobalt Substances 0.000 claims abstract description 53
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims abstract description 53
- 239000002245 particle Substances 0.000 claims abstract description 38
- 239000001257 hydrogen Substances 0.000 claims abstract description 29
- 229910052739 hydrogen Inorganic materials 0.000 claims abstract description 29
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims abstract description 28
- 239000006247 magnetic powder Substances 0.000 claims abstract description 23
- 239000002270 dispersing agent Substances 0.000 claims abstract description 19
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 17
- 239000012429 reaction media Substances 0.000 claims abstract description 8
- 238000000034 method Methods 0.000 claims description 44
- 239000010419 fine particle Substances 0.000 claims description 27
- 229910021503 Cobalt(II) hydroxide Inorganic materials 0.000 claims description 26
- ASKVAEGIVYSGNY-UHFFFAOYSA-L cobalt(ii) hydroxide Chemical compound [OH-].[OH-].[Co+2] ASKVAEGIVYSGNY-UHFFFAOYSA-L 0.000 claims description 25
- 239000007791 liquid phase Substances 0.000 claims description 6
- 239000000696 magnetic material Substances 0.000 claims description 2
- 239000000843 powder Substances 0.000 abstract description 28
- 238000006243 chemical reaction Methods 0.000 abstract description 21
- 239000013078 crystal Substances 0.000 abstract description 17
- 230000005415 magnetization Effects 0.000 abstract description 14
- 239000004094 surface-active agent Substances 0.000 abstract description 7
- 150000002431 hydrogen Chemical class 0.000 abstract description 2
- 230000002542 deteriorative effect Effects 0.000 abstract 1
- -1 reaction conditions Substances 0.000 description 13
- 238000006722 reduction reaction Methods 0.000 description 13
- 230000009467 reduction Effects 0.000 description 12
- 239000012071 phase Substances 0.000 description 10
- 238000005245 sintering Methods 0.000 description 9
- 239000002994 raw material Substances 0.000 description 8
- 229910052708 sodium Inorganic materials 0.000 description 8
- 239000011734 sodium Substances 0.000 description 8
- 239000007789 gas Substances 0.000 description 7
- RYYKJJJTJZKILX-UHFFFAOYSA-M sodium octadecanoate Chemical compound [Na+].CCCCCCCCCCCCCCCCCC([O-])=O RYYKJJJTJZKILX-UHFFFAOYSA-M 0.000 description 7
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 5
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 4
- 239000003638 chemical reducing agent Substances 0.000 description 4
- 150000001868 cobalt Chemical class 0.000 description 4
- 238000002474 experimental method Methods 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 239000002002 slurry Substances 0.000 description 4
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 3
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- 239000002202 Polyethylene glycol Substances 0.000 description 3
- 230000002776 aggregation Effects 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- 229920001223 polyethylene glycol Polymers 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 description 2
- 238000005054 agglomeration Methods 0.000 description 2
- 239000008346 aqueous phase Substances 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 238000005345 coagulation Methods 0.000 description 2
- 230000015271 coagulation Effects 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000010408 film Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- AJCDFVKYMIUXCR-UHFFFAOYSA-N oxobarium;oxo(oxoferriooxy)iron Chemical compound [Ba]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O AJCDFVKYMIUXCR-UHFFFAOYSA-N 0.000 description 2
- 230000002265 prevention Effects 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- BDHFUVZGWQCTTF-UHFFFAOYSA-M sulfonate Chemical compound [O-]S(=O)=O BDHFUVZGWQCTTF-UHFFFAOYSA-M 0.000 description 2
- 239000012808 vapor phase Substances 0.000 description 2
- CMCBDXRRFKYBDG-UHFFFAOYSA-N 1-dodecoxydodecane Chemical compound CCCCCCCCCCCCOCCCCCCCCCCCC CMCBDXRRFKYBDG-UHFFFAOYSA-N 0.000 description 1
- RFVNOJDQRGSOEL-UHFFFAOYSA-N 2-hydroxyethyl octadecanoate Chemical compound CCCCCCCCCCCCCCCCCC(=O)OCCO RFVNOJDQRGSOEL-UHFFFAOYSA-N 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 1
- KXDHJXZQYSOELW-UHFFFAOYSA-N Carbamic acid Chemical class NC(O)=O KXDHJXZQYSOELW-UHFFFAOYSA-N 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910019142 PO4 Inorganic materials 0.000 description 1
- 239000004698 Polyethylene Substances 0.000 description 1
- JUJWROOIHBZHMG-UHFFFAOYSA-N Pyridine Chemical class C1=CC=NC=C1 JUJWROOIHBZHMG-UHFFFAOYSA-N 0.000 description 1
- DBMJMQXJHONAFJ-UHFFFAOYSA-M Sodium laurylsulphate Chemical compound [Na+].CCCCCCCCCCCCOS([O-])(=O)=O DBMJMQXJHONAFJ-UHFFFAOYSA-M 0.000 description 1
- NWGKJDSIEKMTRX-AAZCQSIUSA-N Sorbitan monooleate Chemical compound CCCCCCCC\C=C/CCCCCCCC(=O)OC[C@@H](O)[C@H]1OC[C@H](O)[C@H]1O NWGKJDSIEKMTRX-AAZCQSIUSA-N 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical class OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 239000012190 activator Substances 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 238000004220 aggregation Methods 0.000 description 1
- 150000001346 alkyl aryl ethers Chemical class 0.000 description 1
- 150000005215 alkyl ethers Chemical class 0.000 description 1
- 125000000217 alkyl group Chemical group 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
- 150000003863 ammonium salts Chemical class 0.000 description 1
- 239000002280 amphoteric surfactant Substances 0.000 description 1
- 239000003945 anionic surfactant Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 150000001734 carboxylic acid salts Chemical class 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 239000003093 cationic surfactant Substances 0.000 description 1
- 238000005119 centrifugation Methods 0.000 description 1
- 238000003889 chemical engineering Methods 0.000 description 1
- 229910000428 cobalt oxide Inorganic materials 0.000 description 1
- IVMYJDGYRUAWML-UHFFFAOYSA-N cobalt(ii) oxide Chemical compound [Co]=O IVMYJDGYRUAWML-UHFFFAOYSA-N 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- ZBCBWPMODOFKDW-UHFFFAOYSA-N diethanolamine Chemical class OCCNCCO ZBCBWPMODOFKDW-UHFFFAOYSA-N 0.000 description 1
- IJKVHSBPTUYDLN-UHFFFAOYSA-N dihydroxy(oxo)silane Chemical compound O[Si](O)=O IJKVHSBPTUYDLN-UHFFFAOYSA-N 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- GVGUFUZHNYFZLC-UHFFFAOYSA-N dodecyl benzenesulfonate;sodium Chemical compound [Na].CCCCCCCCCCCCOS(=O)(=O)C1=CC=CC=C1 GVGUFUZHNYFZLC-UHFFFAOYSA-N 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 230000005307 ferromagnetism Effects 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- MTNDZQHUAFNZQY-UHFFFAOYSA-N imidazoline Chemical class C1CN=CN1 MTNDZQHUAFNZQY-UHFFFAOYSA-N 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 239000002563 ionic surfactant Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 150000002736 metal compounds Chemical class 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- XKBGEWXEAPTVCK-UHFFFAOYSA-M methyltrioctylammonium chloride Chemical compound [Cl-].CCCCCCCC[N+](C)(CCCCCCCC)CCCCCCCC XKBGEWXEAPTVCK-UHFFFAOYSA-M 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000012299 nitrogen atmosphere Substances 0.000 description 1
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 description 1
- 239000002736 nonionic surfactant Substances 0.000 description 1
- GSGDTSDELPUTKU-UHFFFAOYSA-N nonoxybenzene Chemical compound CCCCCCCCCOC1=CC=CC=C1 GSGDTSDELPUTKU-UHFFFAOYSA-N 0.000 description 1
- 125000005010 perfluoroalkyl group Chemical group 0.000 description 1
- 239000010452 phosphate Substances 0.000 description 1
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 1
- QVLTXCYWHPZMCA-UHFFFAOYSA-N po4-po4 Chemical compound OP(O)(O)=O.OP(O)(O)=O QVLTXCYWHPZMCA-UHFFFAOYSA-N 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 150000003377 silicon compounds Chemical class 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 238000010583 slow cooling Methods 0.000 description 1
- 229940080264 sodium dodecylbenzenesulfonate Drugs 0.000 description 1
- 235000019333 sodium laurylsulphate Nutrition 0.000 description 1
- 239000001488 sodium phosphate Substances 0.000 description 1
- 229910000162 sodium phosphate Inorganic materials 0.000 description 1
- 229940074404 sodium succinate Drugs 0.000 description 1
- ZDQYSKICYIVCPN-UHFFFAOYSA-L sodium succinate (anhydrous) Chemical compound [Na+].[Na+].[O-]C(=O)CCC([O-])=O ZDQYSKICYIVCPN-UHFFFAOYSA-L 0.000 description 1
- DAJSVUQLFFJUSX-UHFFFAOYSA-M sodium;dodecane-1-sulfonate Chemical compound [Na+].CCCCCCCCCCCCS([O-])(=O)=O DAJSVUQLFFJUSX-UHFFFAOYSA-M 0.000 description 1
- 229950004959 sorbitan oleate Drugs 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 150000003871 sulfonates Chemical class 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- 238000011282 treatment Methods 0.000 description 1
- 238000001132 ultrasonic dispersion Methods 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 239000004711 α-olefin 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
- H01F1/065—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys in the form of particles, e.g. powder obtained by a reduction
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は磁性材料や触媒として、特に高密度な磁気記録
を可能とする垂直磁気記録方式のための記録媒体（テー
プ、ディスク、ドラム等）用の磁性粉として有用な新規
な六方晶コバルト六角板状磁性粉の製造法に関する。[Detailed Description of the Invention] [Industrial Application Field] The present invention is applied as a magnetic material or catalyst to recording media (tapes, disks, drums, etc.) for perpendicular magnetic recording systems that enable particularly high-density magnetic recording. The present invention relates to a method for producing a novel hexagonal cobalt hexagonal plate-shaped magnetic powder useful as a magnetic powder for industrial use.
高密度な磁性記録方式としては現行の長手方式と異なっ
た垂直方式が提唱され、その優れた記録性能が蒸着膜、
スパッター膜、メツキ膜の様な薄膜型記録媒体で試験的
に実証されている。この新方式を商業的に有利な塗布型
記録媒体で実用化するために新たな特性を持つ磁性粉と
して、例えばバリウムフェライト微粒子粉末が最近開発
されてきた。A perpendicular method, which is different from the current longitudinal method, has been proposed as a high-density magnetic recording method.
It has been experimentally demonstrated on thin film recording media such as sputtered films and plated films. In order to put this new method into practical use in a commercially advantageous coated recording medium, barium ferrite fine particle powder, for example, has recently been developed as a magnetic powder with new characteristics.
しかして、もし、該バリウムフェライト微粒子（通常的
５５ｅｍｕ／ｇ ）よりも高い飽和磁化（１００ｅａ＋
ｕ７ｇ以上）を有するコバルト微粒子を六方晶系の結晶
格子状で且つ適当な保磁力（５００〜２．００００ｓ）
、サブミクロン以下の粒径と均一な分散性を示す磁性粉
末として製造できれば、これよりもずっと侵れた結晶−
軸磁気異方性を具備する垂直記録用素材となることが期
待される。However, if the saturation magnetization (100ea+
cobalt fine particles having a hexagonal crystal lattice shape and an appropriate coercive force (500 to 2.0000 s)
If it could be produced as a magnetic powder with a submicron particle size and uniform dispersibility, it would be possible to produce a much more eroded crystal.
It is expected that this material will become a perpendicular recording material with axial magnetic anisotropy.
従来、金属状コバルトの粉末またはゾルの製造法として
は、大別すると、（１）コバルト酸化物または水酸化物
を高温で気相水素還元する方法、（２）コバルトカルボ
ニルまたはコバルト塩を液相熱分解する方法、（３）コ
バルト塩を高温で気相水素還元する方法、（４）コバル
ト塩を液相媒体中で水素または還元性試剤により還元す
る方法と、（５）コバルト電極で還元剤存在下に水電解
する方法、（６）金属状コバルトを不活性ガス中で高温
蒸発させる方法等が公知である。Conventionally, methods for producing metallic cobalt powder or sol can be roughly divided into (1) a method in which cobalt oxide or hydroxide is reduced with hydrogen in the vapor phase at high temperatures, and (2) a method in which cobalt carbonyl or cobalt salt is reduced in a liquid phase. (3) a method of reducing a cobalt salt with hydrogen in the vapor phase at high temperature; (4) a method of reducing a cobalt salt with hydrogen or a reducing agent in a liquid phase medium; and (5) a method of reducing a cobalt salt with hydrogen or a reducing agent at a cobalt electrode. A method in which water is electrolyzed in the presence of cobalt, and (6) a method in which metallic cobalt is evaporated at high temperature in an inert gas are known.
本発明の製造法はこの様な方法に属さない全く新規な方
法である。因に、上記の（１）から（６）の方法では純
度、結晶格子、結晶性、粒径または分散性等において本
発明の目的に合致するコバルト微粒子は得られていない
。The production method of the present invention is a completely new method that does not belong to such methods. Incidentally, cobalt fine particles meeting the objectives of the present invention in terms of purity, crystal lattice, crystallinity, particle size, dispersibility, etc., cannot be obtained by methods (1) to (6) above.
コバルト水酸化物を原料とするコバルｉｆｆ性粉の製造
法としては、例えば水酸化コバルトを高温で熱処理して
酸化物としこれを高温で気相水素還元する方法（例えば
特開昭５４−７５５９７号）、水酸化コバルト粒子の表
面に銅、ニッケル、硅素化合物の様な焼結防止剤を付け
てから高温熱処理した後、高温気相で水素還元する方法
（例えば特開昭５９−１７２２０９号、同５９−１７２
２１０号、同５９−１７３２０７号、同５９−１７３２
０８号）や水酸化コバルトを熱処理して酸化物Ｃｏ３Ｏ
４とした後、焼結防止剤の硅酸塩を表面に付け、次いで
高温気相で水素還元する方法（特開昭６０−１００６０
６号）等が知られている。As a method for producing cobalt iff powder using cobalt hydroxide as a raw material, for example, cobalt hydroxide is heat-treated at high temperature to form an oxide, which is then reduced with gas phase hydrogen at high temperature (e.g., JP-A-54-75597). ), a method in which an anti-sintering agent such as copper, nickel, or a silicon compound is applied to the surface of cobalt hydroxide particles, heat treatment is performed at a high temperature, and then hydrogen reduction is performed in a high-temperature gas phase (for example, JP-A-59-172209, 59-172
No. 210, No. 59-173207, No. 59-1732
08) and cobalt hydroxide to form oxide Co3O.
4, apply silicate as an anti-sintering agent to the surface, and then reduce it with hydrogen in a high-temperature gas phase (Japanese Patent Application Laid-Open No. 60-10060).
No. 6) etc. are known.
しかしながら、この様な公知の方法では高温気相還元す
るために面心立方晶コバルトが生成し、基本的に重要な
高純度の六方晶結晶が得られず、その上微粒子の焼結が
起こる。これを防ぐためには、磁性鉄粉の製造法におけ
ると同一の手法を通用し、複雑な工程で焼結防止対策し
ているが、その効果は充分ではなく、本発明の目的物を
製造す゛る方法として、別置実用的に満足できるもので
はない。However, in such known methods, face-centered cubic cobalt is produced due to the high-temperature gas phase reduction, and fundamentally important high-purity hexagonal crystals cannot be obtained, and furthermore, sintering of fine particles occurs. In order to prevent this, the same method as in the manufacturing method of magnetic iron powder is used to prevent sintering through a complicated process, but the effect is not sufficient, and the method for manufacturing the object of the present invention is As such, it is not practical to install separately.
本発明者らは、これら公知の高温気相還元法と全く異な
り、水酸化コバルトを水の反応媒体中で低温液相水素還
元する方法を提案した（特願昭６１−２４５４２７号）
、これは最も経済的な製法であるが、生成磁性粉の磁気
特性等を大巾な範囲で任意に設計するには、更に改良が
必要となった。即ち、保磁力を７０００ｅ程度以上から
高め、また角形比や比表面積も比較的大きく設定できる
様にすることである。The present inventors have proposed a method for reducing cobalt hydroxide with hydrogen in a low-temperature liquid phase in a water reaction medium, which is completely different from these known high-temperature gas-phase reduction methods (Japanese Patent Application No. 61-245427).
Although this is the most economical manufacturing method, further improvements are required in order to arbitrarily design the magnetic properties of the produced magnetic powder over a wide range. That is, the coercive force should be increased from about 7000e or more, and the squareness ratio and specific surface area should also be set relatively large.
本発明は水酸化コバルトを分散剤存在下の水中で、１５
０から３００°Ｃの比較的低温で水素加圧下に液相水素
還元する方法を提供するものであり、より詳しくはかか
る点を特徴とする新規な高純度六方晶コバルト六角また
は多角板状または粒状微粒子磁性粉の製造方法を提供す
るものである。In the present invention, cobalt hydroxide is dissolved in water in the presence of a dispersant for 15
The purpose is to provide a method for liquid phase hydrogen reduction under hydrogen pressure at a relatively low temperature of 0 to 300°C, and more specifically, a novel high-purity hexagonal cobalt hexagonal or polygonal plate-like or granular form characterized by this point. The present invention provides a method for producing fine particle magnetic powder.
金属コバルト粒子の結晶格子には六方晶系と面心立方晶
系があり、前者は低温安定性型のため約３００℃以下の
特定の条件で生成し、４００℃以上の様な高温還元では
通常主として後者が生じる。この再結晶系の転移温度は
約３００から４００℃程度であり、高温からの徐冷によ
り六方晶を増すことは出来るが、十分な転位はできず、
両結晶格子の混合状態となる０本発明の目的たる垂直磁
気記録用磁性粉に使用するためには、結晶性がよ（且つ
一軸結晶磁気異方性を示す出来るだけ純粋な六方晶系コ
バルトが必要である。公知の製造法では高温で気相還元
するために生成する面心立方晶系の混入は避けられず、
かつ結晶性も満足されない。The crystal lattice of metallic cobalt particles has a hexagonal system and a face-centered cubic system, and the former is stable at low temperatures, so it is produced under specific conditions of about 300°C or less, and it usually does not occur under high-temperature reduction such as over 400°C. The latter mainly occurs. The transition temperature of this recrystallized system is about 300 to 400°C, and although it is possible to increase the hexagonal crystal structure by slow cooling from a high temperature, sufficient dislocation cannot occur.
In order to use the magnetic powder for perpendicular magnetic recording, which is the object of the present invention, it is necessary to use hexagonal cobalt that has good crystallinity (and exhibits uniaxial magnetocrystalline anisotropy) as pure as possible. In known production methods, the inclusion of face-centered cubic crystal systems produced due to high-temperature gas phase reduction is unavoidable.
Moreover, crystallinity is also not satisfied.
次に垂直磁気記録用磁性粉の粒子形とサイズは（六角）
板状または粒状粒子で粒径がサブミクロン程度またはそ
れ以下で分布中が狭く、更に焼結や凝結のない均一に分
散した微粒子が望まれる。Next, the particle shape and size of magnetic powder for perpendicular magnetic recording are (hexagonal)
It is desirable to have plate-like or granular particles with a particle size of about submicron or smaller, a narrow distribution, and uniformly dispersed particles without sintering or aggregation.
しかしながら、前記公知の方法では、この様な粒径の水
酸化コバルト微粒子を原料に用いても高温で気相水素還
元する方法のために粒子間の焼結物や凝集物の混入が不
可避となり、粒子の形状と粒径が保持されず、分散性も
悪い、さらに、粒子形は板状であり、粒径並びに粒径と
厚みの比が出来るだけ揃った微粒子から成る磁性粉が望
ましい。However, in the above-mentioned known method, even if cobalt hydroxide fine particles of such a particle size are used as a raw material, the method of gas phase hydrogen reduction at high temperature inevitably causes contamination of sintered substances and aggregates between particles. It is desirable to use a magnetic powder consisting of fine particles whose particle shape and particle size are not maintained and whose dispersibility is poor.Furthermore, the particle shape is plate-like, and the particle size and particle size-to-thickness ratio are as uniform as possible.
また静的磁気特性に関して基本的には飽和磁化、保磁力
と角形比が重要となる。純粋な金属コバルト自身は飽和
磁化が１６１ｅｍｕ／ｇ（２０℃）とバリウムフェライ
トの２倍以上の優れた素材であり、−方探磁力は５００
から２，００００ｅ 、特に７００から１．５０００
ｅの範囲が、また角形比は高い方が実用上望ましい、従
って出来るだけもともと優れている飽和磁化を低下させ
ずに適当な保磁力を有する耐食性のよい安定な磁性粉を
製造できる方法を開発することが肝要である。Regarding static magnetic properties, saturation magnetization, coercive force, and squareness ratio are basically important. Pure metal cobalt itself is an excellent material with a saturation magnetization of 161 emu/g (20°C), more than twice that of barium ferrite, and a -direction magnetic force of 500
from 2,0000e, especially from 700 to 1.5000
It is practically desirable that the range of e is high and the squareness ratio is high.Therefore, we will develop a method that can produce stable magnetic powder with appropriate coercive force and good corrosion resistance without reducing the originally excellent saturation magnetization as much as possible. That is essential.
更に出来るだけ異種の物質を混入させずに簡略な再現性
のよい方法によって、経済的に前記目的に沿うコバルト
磁性粉を量産できる方法であることも特に実用上から重
要な問題となる。Furthermore, it is particularly important from a practical standpoint to find a method that can economically mass-produce cobalt magnetic powder that meets the above objectives by a simple method with good reproducibility and without mixing different types of substances as much as possible.
本発明の目的は、上記の如き垂直磁気記録用磁性粉とし
て要求される（１）結晶性のよい六方晶系格子を有し、
（２）粒径０．０１から１μ曙の分散性のよい安定な六
角または多角板状または粒状粒子で且つ（３）高い飽和
磁化（１００ｅａｕ／ｇ以上）と適当な保磁力（５００
〜２．００００ｅ ）を示すという困難な諸要求を全て
同時に充足した（４）純粋なコバルト微粒子粉末を製造
する方法を提供することにある。The object of the present invention is to (1) have a hexagonal lattice with good crystallinity, which is required for a magnetic powder for perpendicular magnetic recording as described above;
(2) Stable hexagonal or polygonal plate-shaped or granular particles with good dispersibility with a particle size of 0.01 to 1μ; and (3) high saturation magnetization (100 eau/g or more) and appropriate coercive force (500 eau/g or more).
The object of the present invention is to provide (4) a method for producing pure cobalt fine particle powder that simultaneously satisfies all of the difficult requirements of exhibiting .about.2.0000e).
本発明者らは、かかる目的を達成するために鋭意検討を
行った結果、水酸化コバルト微粒子粉末を、面心立方晶
コバルトの生成温度以下でしかも微粒子の焼結や凝結を
起こしに（い様な比較的低温において、適当な分散剤を
用いることにより水中に十分分散させた状態で、しかも
生成する還元コバルト微粒子も同様によく分散された状
態を保つ様な分散系を構築した上で、もし直接水素還元
できれば、上記課題を全て満足するコバルト粒子粉末が
得られるのではと着想し、分散剤や反応条件と生成物の
関係を鋭意研究した結果本発明を完成するに到った。As a result of extensive studies to achieve this objective, the present inventors have determined that fine particles of cobalt hydroxide can be used at a temperature below the formation temperature of face-centered cubic cobalt and in a manner that does not cause sintering or coagulation of the fine particles. At a relatively low temperature, by using an appropriate dispersant, we can construct a dispersion system in which the reduced cobalt particles are sufficiently dispersed in water, and the resulting reduced cobalt fine particles can also be maintained in a well-dispersed state. The idea was that if direct hydrogen reduction could be performed, cobalt particles that would satisfy all of the above problems could be obtained, and as a result of intensive research into the relationship between dispersants, reaction conditions, and products, the present invention was completed.
すなわち、本発明は、コバルト磁性粉の製造方法であっ
て、水酸化コバルトを反応媒体としての水中で分散剤の
存在下、１５０から３００°Ｃで水素加圧下に直接水相
水素還元することを特徴とする六方晶コバルトの板状ま
たは粒状微粒子から成る磁性粉の製造法である。That is, the present invention is a method for producing cobalt magnetic powder, which comprises directly reducing cobalt hydroxide with hydrogen in water as a reaction medium in the presence of a dispersant at 150 to 300°C under hydrogen pressure in the aqueous phase. This is a method for producing magnetic powder consisting of plate-like or granular fine particles of hexagonal cobalt.
本発明は水酸化コバルトを水中に分散させ、分散剤の存
在下に低温高圧で直接液相水素還元することを大きな特
徴とするが、このようなコバルト微粒子粉末の製造方法
は本発明により初めて開示された方法である。コバルト
水酸化物の高温気相還元では、磁性鉄粉の製造方法にお
けるが如き方法と類似な手法を用いることにより、焼結
を防ぐ種々な方法が前記の様に提案されており、また予
め熱処理して生じる酸化物を焼結防止しながら還元する
方法も公知であるが、本発明はこれらが抱える基本的な
問題、特に前記した課題を根本的に解決する全（新規な
経済的方法を提供するものである。A major feature of the present invention is that cobalt hydroxide is dispersed in water and subjected to direct liquid-phase hydrogen reduction at low temperature and high pressure in the presence of a dispersant, and the present invention discloses a method for producing such fine cobalt powder for the first time. This is how it was done. In the high-temperature gas phase reduction of cobalt hydroxide, various methods have been proposed to prevent sintering by using methods similar to those used in the production of magnetic iron powder, and also to prevent sintering by pre-heat treatment. Methods for reducing the oxides produced by oxidation while preventing sintering are also known, but the present invention provides a novel economical method that fundamentally solves the fundamental problems faced by these, especially the problems mentioned above. It is something to do.
本発明の方法に用いられる原料は水酸化コバルトであり
、種々な公知の方法によって製造される六方晶系結晶格
子の六角板状または板状晶で主として粒径が０．０１か
ら１μ−程度の粒子が好ましいものとして使用される。The raw material used in the method of the present invention is cobalt hydroxide, which is a hexagonal plate or plate crystal with a hexagonal crystal lattice produced by various known methods and mainly has a particle size of about 0.01 to 1μ. Particles are preferably used.
しかしながら、かかる水酸化コバルトを主体とするもの
であるかぎり、公知の方法により処理または変性された
水酸化コバルト化合物、たとえば、シリカ、アルミナ、
ニッケル等の種々な金属または金属化合物が添加された
ものを用いてもよい。However, as long as the cobalt hydroxide compound is mainly composed of cobalt hydroxide, cobalt hydroxide compounds treated or modified by known methods, such as silica, alumina,
Materials to which various metals or metal compounds such as nickel are added may also be used.
反応は異相系反応であり、生成コバルト粒子の粒径と分
散性を制御するために、分散剤の存在下に実施すること
が重要且つ不可欠である０分散剤としてはイオン系また
は非イオン系界面活性剤等が用いられる。The reaction is a heterophasic reaction, and it is important and essential to conduct it in the presence of a dispersant in order to control the particle size and dispersibility of the produced cobalt particles.The dispersant may be an ionic or nonionic interface. An activator or the like is used.
かかる界面活性剤としては種々のものを選んで用いるこ
とが出来る０例えば、代表例で示すと、イオン系のもの
として例えばラウリルスルホン酸ソーダ、ドデシルベン
ゼンスルホン酸ソーダ、アルキルナフタレンスルホン酸
ソーダ、ジオクチルスルホこはく酸ソーダ、α−オレフ
ィンスルホン酸ソーダ、Ｎ−アシルアミノスルホン酸ソ
ーダ、パーフルオロアルキルスルホン酸アンモニウム等
の様なスルホン酸塩；例えばステアリン酸ソーダ、アル
キルエーテルカルボン酸ソーダ、Ｎ−アシルアミノ酸ソ
ーダ、パーフルオロアルキルカルボン酸ソーダ等の様な
カルボン酸塩、； 例えばラウリル硫酸ソーダ、アルキ
ルエーテル硫酸ソーダ、アルキルアリールエーテル硫酸
ソーダ、アルキルアミド硫酸ソーダ等の様な硫酸エステ
ルと例えばアルキルリン酸ソーダ、リン酸ジ（ポリエチ
レングリコール−ｐ−ノニルフェニル）ソータ、パーフ
ルオロアルキルリン酸ソーダ等の様なリン酸塩のアニオ
ン界面活性剤；例えばトリオクチルメチルアンモニウム
クロライド、パーフルオロアルキルメチルアンモニウム
クロライド等の様な４級アンモニウム塩；脂肪族アミン
塩；ピリジニウム塩とイミダゾリニウム塩等の様なカチ
オン界面活性剤；ベタイン、パーフルオロアルキルベタ
イン、アミノカルボン酸塩等の様な両性界面活性剤が用
いられる。ノニオン系のものとしては、例えばポリエチ
レングリコールラウリルエーテル、ポリエチレングリコ
ールノニルフェニルエーテル、パーフルオロアルキルポ
リオキシエチレンエタノール等の様なエーテル型のもの
；例えばポリエチレングリコールモノステアレート、ソ
ルビタンオレエート、フルオロアルキルエステル等の様
なエステル型のもの；エーテルエステル型のもの；例え
ばポリオキシエチレンエチルアミン、パーフルオロアル
キルアミンオキシド等の様な窒素含有型のもの等の様な
ノニオン界面活性剤が使い分けられる。Various surfactants can be selected and used as such surfactants. For example, representative examples include ionic surfactants such as sodium lauryl sulfonate, sodium dodecylbenzenesulfonate, sodium alkylnaphthalene sulfonate, and dioctyl sulfonate. Sulfonates such as sodium succinate, sodium α-olefin sulfonate, sodium N-acylaminosulfonate, ammonium perfluoroalkylsulfonate, etc.; e.g. sodium stearate, sodium alkyl ether carboxylate, sodium N-acylamino acid, carboxylic acid salts such as sodium perfluoroalkyl carboxylates; sulfuric acid esters such as sodium lauryl sulfate, sodium alkyl ether sulfate, sodium alkylaryl ether sulfate, sodium alkylamide sulfate, etc.; and phosphoric acid, such as sodium alkyl phosphate, phosphoric acid Phosphate anionic surfactants such as di(polyethylene glycol-p-nonylphenyl)sorta, perfluoroalkyl sodium phosphate, etc.; quaternary surfactants such as trioctylmethylammonium chloride, perfluoroalkylmethylammonium chloride, etc. Ammonium salts; aliphatic amine salts; cationic surfactants such as pyridinium salts and imidazolinium salts; amphoteric surfactants such as betaines, perfluoroalkylbetaines, aminocarboxylate salts, etc. are used. Nonionic ones include ether type ones such as polyethylene glycol lauryl ether, polyethylene glycol nonylphenyl ether, perfluoroalkyl polyoxyethylene ethanol, etc.; for example, polyethylene glycol monostearate, sorbitan oleate, fluoroalkyl ester, etc. Nonionic surfactants such as ester type surfactants; ether ester type surfactants; nitrogen-containing surfactants such as polyoxyethylene ethylamine, perfluoroalkyl amine oxide, etc. can be used.
分散剤の使用量は特別の制限はないが、通常水に対して
０．００１から１重量％であり、特に０．０１から０．
５重量％が望ましい。There is no particular limit to the amount of the dispersant used, but it is usually 0.001 to 1% by weight, particularly 0.01 to 0.0% by weight, based on water.
5% by weight is desirable.
本発明においては、水酸化コバルトの水相加圧水素還元
において適当な分散剤を用いることにより、還元コバル
ト微粉末の保磁力と角形比を高めて磁気特性を改善し、
更に比表面積も大きくすることができる。In the present invention, by using an appropriate dispersant in the aqueous phase pressurized hydrogen reduction of cobalt hydroxide, the coercive force and squareness ratio of the reduced cobalt fine powder are increased and the magnetic properties are improved.
Furthermore, the specific surface area can also be increased.
またコバルト微粒子の表面改質、酸化防止、安定化、凝
集防止、磁性調節等の目的でコバルトその他の金属微粒
子または磁性粉の製造に関して公−知の添加物質やその
処決を本発明の製造法に加味することもできる。In addition, known additives and treatments for the production of cobalt and other metal fine particles or magnetic powders for the purpose of surface modification, oxidation prevention, stabilization, prevention of agglomeration, and magnetic adjustment of cobalt fine particles can be used in the production method of the present invention. It can also be added to.
本発明では還元剤として水素を使用するが、ここで使用
する還元剤の水素は特に純度的制限はな（、反応に関し
ては不活性な成分であれば混入していても勿論構わない
０例えば窒素、炭化水素等の混合した低純度水素も用い
られる。In the present invention, hydrogen is used as a reducing agent, but there are no particular purity restrictions for the reducing agent hydrogen used here (for example, nitrogen may be mixed in as long as it is an inert component with respect to the reaction). , low-purity hydrogen mixed with hydrocarbons, etc. may also be used.
本発明において原料水酸化コバルトは反応媒体の水に対
して通常は０．１から２０重量％、望ましくは１から１
０重量％の範囲で用いられる。水素は加圧することが必
要であるが、その圧力に特に制限はない、しかし圧力を
上げる程、反応速度を高めることが出来るので、通常は
５から３００Ｋｇ／ｃｄの範囲で、望ましくは５０から
１５０Ｋｇ／ｃ＋ａの範囲で選ばれる。また反応温度は
１５０から３００°Ｃの範囲で実施されるが、望ましく
は１７０から２５０°Ｃの範囲である。この温度未満で
あると、反応が実質的に進行しないし、また、この温度
を越えた場合は、高温安定型の面心立方晶が副生ずるよ
うになる。In the present invention, the raw material cobalt hydroxide is usually 0.1 to 20% by weight, preferably 1 to 1% by weight, based on the water of the reaction medium.
It is used in a range of 0% by weight. Hydrogen needs to be pressurized, but there are no particular restrictions on the pressure.However, the higher the pressure, the higher the reaction rate, so it is usually in the range of 5 to 300 kg/cd, preferably 50 to 150 kg/cd. /c+a. Further, the reaction temperature is carried out in the range of 150 to 300°C, preferably in the range of 170 to 250°C. If the temperature is below this temperature, the reaction will not substantially proceed, and if it exceeds this temperature, high-temperature stable face-centered cubic crystals will be produced as by-products.
本発明の方法による水酸化コバルトから六方晶コバルト
微粒子への還元の好ましい実施のＢ様としては、上記の
如き水酸化コバルト微粉末と分散剤を水中へ加えてホモ
ジナイザーや超音波分散装置等により分散させた後１、
効果的な混合撹拌または流動状態を化学工学的に公知の
例えば機械的な手段で与えながら上記反応条件で水素と
加熱反応させることにより実施される。In preferred method B of reducing cobalt hydroxide to hexagonal cobalt fine particles by the method of the present invention, the above-mentioned cobalt hydroxide fine powder and a dispersant are added to water and dispersed using a homogenizer, an ultrasonic dispersion device, etc. After letting 1,
The reaction is carried out by heating and reacting with hydrogen under the above reaction conditions while providing effective mixing and stirring or a fluidized state by means known in chemical engineering, for example, mechanical means.
反応時間は原料の水酸化コバルトとその濃度、水素圧力
、反応温度、ゾル状スラ、リー反応相の混合状態によっ
て大幅に異なりうるが、通常は数秒から２０時間程度の
範囲、好ましくは数分から１０時間程度の範囲である。The reaction time can vary greatly depending on the raw material cobalt hydroxide, its concentration, hydrogen pressure, reaction temperature, sol slurry, and the mixing state of the Lee reaction phase, but it usually ranges from several seconds to about 20 hours, preferably from several minutes to 10 hours. The range is about hours.
還元反応は回文式または連続式の種々属地形式を採用し
て実施できるが、原料と生成物がゾル状スラリーを形成
しこの状態において水素ガスを吸収せしめて反応させる
ことになるので、反応相の混合をよくすることが肝要で
ある。この際に前記の反応条件を適当に選択することに
よって円滑に還元を進行させ、反応中の凝結を抑えて微
粒子の形状を保持することができる。The reduction reaction can be carried out in various forms, such as palindromic or continuous, but since the raw materials and products form a sol-like slurry, and in this state hydrogen gas is absorbed and reacted, the reaction phase is It is important to mix well. At this time, by appropriately selecting the reaction conditions described above, the reduction can proceed smoothly, coagulation during the reaction can be suppressed, and the shape of the fine particles can be maintained.
本発明においては、かくして水酸化コバルト粉末から六
方晶六角または多角板状または粒状のコバルト微粒子粉
末が反応を完結させることによって実質的に１００％の
収率で生成させることができる。In the present invention, hexagonal hexagonal or polygonal plate-like or granular cobalt fine particle powder can be produced from cobalt hydroxide powder in a substantially 100% yield by completing the reaction.
生成するコバルト微粒子は反応器からゾル状スラリー状
で取り出し、反応媒体から１頃斜、濾過、遠心分離等の
公知の方法で分離し、その尽でまたは必要に応じて洗浄
、徐酸化して乾燥することにより空気中で安定なコバル
ト微粒子磁性粉末を製造できる。The produced cobalt fine particles are taken out of the reactor in the form of a sol-like slurry, separated from the reaction medium by a known method such as decanting, filtration, or centrifugation, and then washed, slowly oxidized, and dried when exhausted or as necessary. By doing so, it is possible to produce cobalt fine particle magnetic powder that is stable in the air.
過剰の未反応水素ガス、分離回収された反応媒体と洗液
はその尽または慣用の方法で精製して容易に再使用され
る。Excess unreacted hydrogen gas, separated and recovered reaction medium and washing liquid can be used up or purified by conventional methods and easily reused.
本発明の方法に従えば、結晶性のよい六方晶結晶格子の
高純度コバルト微粒子から成るコバルト微粉末を容易に
製造することができ、この微粒子の形状、サイズと分散
は原料に用いた水酸化コバルト粒子にも依存するが、主
として粒径０．０１から１μｌ、特に０．０３から０．
３μ階の範囲で比較的粒径が揃った六角または多角板状
または粒状を呈し、粒径と厚みの比が約２から１０程度
の分散した微粒子を主とする黒色微粉末である。この微
粉末は飽和磁化１００から１５０ｅｍｕ／ｇの安定した
強磁性を示し、保磁力５００から２，００００ｅ 特
に７００から１．５０００ｅ の値を有するので、特
に垂直磁気録媒体用に最適であり、有用な新規磁性粉と
なる。According to the method of the present invention, it is possible to easily produce cobalt fine powder consisting of high-purity cobalt fine particles in a hexagonal crystal lattice with good crystallinity, and the shape, size and dispersion of the fine particles are determined by the hydroxide used as the raw material. Although it depends on the cobalt particles, the particle size is mainly from 0.01 to 1 μl, especially from 0.03 to 0.0 μl.
It is a black fine powder mainly consisting of dispersed fine particles with a hexagonal or polygonal plate shape or a granular shape with a relatively uniform particle size in the 3μ order range, and a particle size to thickness ratio of about 2 to 10. This fine powder exhibits stable ferromagnetism with a saturation magnetization of 100 to 150 emu/g and a coercive force of 500 to 2,0000e, especially 700 to 1.5000e, making it particularly suitable and useful for perpendicular magnetic recording media. It becomes a new magnetic powder.
以下実施例により本発明の好ましい実施の態様を具体的
に説明する。Hereinafter, preferred embodiments of the present invention will be specifically explained with reference to Examples.
実施例１
水酸化コバルト桃色微粉末（平均粒径０．１０μｍの六
角板状晶で凝集せずによ（分散されるもの）２．３２ｇ
とステアリン酸ソーダ０．０４ｇを水２００ｍｊ２中に
入れ加温しながら十分に分散処理後、これを５００
ｍｌステンレスオートクレーブに窒素雰囲気下に仕込み
、水素をｌｏＯＫｇ／ｃｄ圧大した後、８００ｒｐｍの
速度で攪拌しながら１８０°Ｃで１０分間反応を行った
。冷却、放圧してから内容物を取り出し、水を分離した
０次いで黒色泥状粉末をメタノールで洗浄し、乾燥する
と空気中で安定な黒色コバルト微粉末１．５０ｇが得ら
れた。この粉末はＸ線分析によると結晶性のよい六方晶
系コバルトを示し、面心立方晶は認められず、高純度の
コバルト結晶であることがｆ！認された。電子顕微鏡に
よると、粒径０．０５〜０．１５μｍの主として粒状と
（六角）板状の微粒子から成ることがわかった。この微
粉末は振動試料型磁力計により１０ ＫＯｅまで磁化し
た飽和磁化は１３１ ｅｍｕ／ｇ 、保磁力は８２００
ｅ 、角形比は０．３８８であり、比表面積は１８．２
ｍ”／ｇであった。Example 1 2.32 g of cobalt hydroxide pink fine powder (dispersed without agglomeration in hexagonal plate-like crystals with an average particle size of 0.10 μm)
Add 0.04 g of sodium stearate to 200 mj2 of water and thoroughly disperse while heating.
A stainless steel autoclave was charged under a nitrogen atmosphere, hydrogen was increased to lo OK g/cd, and the reaction was carried out at 180° C. for 10 minutes while stirring at a speed of 800 rpm. After cooling and releasing the pressure, the contents were taken out, water was separated, and the black slurry powder was washed with methanol and dried to obtain 1.50 g of black cobalt fine powder stable in the air. According to X-ray analysis, this powder shows hexagonal cobalt with good crystallinity, and no face-centered cubic crystals are observed, indicating that it is a highly pure cobalt crystal. It has been certified. According to an electron microscope, it was found that it consisted mainly of granular and (hexagonal) plate-like fine particles with a particle size of 0.05 to 0.15 μm. This fine powder was magnetized to 10 KOe using a vibrating sample magnetometer, with a saturation magnetization of 131 emu/g and a coercive force of 8200.
e, squareness ratio is 0.388, specific surface area is 18.2
m”/g.
比較例１
ステアリン酸ソーダを用いない以外は実施例１と同様に
行うと、黒色コバルト微粉末１．２３ｇが得られた。結
晶性のよい高純度の六方晶系結晶であるが 飽和磁化は
１４０ｅ麟ｕ／ｇ 、保磁力は４９００ｅ、角形比は０
．２６０であり、比表面積は７．５Ｎ” ／ｇであった
。Comparative Example 1 In the same manner as in Example 1 except that sodium stearate was not used, 1.23 g of black cobalt fine powder was obtained. It is a high-purity hexagonal crystal with good crystallinity, but the saturation magnetization is 140e/g, the coercive force is 4900e, and the squareness ratio is 0.
．． 260, and the specific surface area was 7.5 N''/g.
実施例２
水酸化コバルト４．６５ｇ とステアリン酸ソーダ０
．２ｇを用いて、２００°Ｃで３０分間反応を行った以
外は実施例１と同様な実験を行ったところ、黒色微粉末
２．８１ ｇが得られた。この粉末は結晶性のよい純粋
な六方晶コバルトから成り、飽和磁化１３５ｅｌｌｕ／
ｇ、保磁カフ７５０ｓ 、角形比０．４０３であり、比
表面積は１８．５ｍ”／ｇを示した。Example 2 4.65 g of cobalt hydroxide and 0 sodium stearate
．． When the same experiment as in Example 1 was conducted except that 2 g was used and the reaction was carried out at 200°C for 30 minutes, 2.81 g of black fine powder was obtained. This powder is made of pure hexagonal cobalt with good crystallinity, and has a saturation magnetization of 135 ellu/
g, coercive cuff 750s, squareness ratio 0.403, and specific surface area 18.5 m''/g.
実施例３
ステアリン酸ソーダ０．３ｇを用いた以外は実施例２と
同様な実験を行ったところ、黒色微粉末２．８５ｇが得
られた。この粉末は結晶性のよい純粋な六方晶コバルト
から成り、飽和磁化１３０ｅｍｕ／ｇ 、保磁力９３５
０ｅ、角形比０．４２６であり、比表面積は１４．７＋
＋＋”／ｇを示した。Example 3 An experiment similar to Example 2 was conducted except that 0.3 g of sodium stearate was used, and 2.85 g of black fine powder was obtained. This powder is made of pure hexagonal cobalt with good crystallinity, has a saturation magnetization of 130 emu/g, and a coercive force of 935.
0e, the squareness ratio is 0.426, and the specific surface area is 14.7+
++”/g.
実施例４
ステアリン酸ソーダ０．４ｇを用いた以外は実施例２と
同様な実験を行ったところ、黒色微粉末２．６２ｇが得
られた。この粉末は結晶性のよい純粋な六方晶コバルト
から成り、飽和磁化１３５ｅｍｕ／ｇ 、保磁カフ８５
０ｅ、角形比０．３９４であり、比表面積は１８．７ｍ
” ／ｇを示した。Example 4 An experiment similar to Example 2 was conducted except that 0.4 g of sodium stearate was used, and 2.62 g of black fine powder was obtained. This powder is made of pure hexagonal cobalt with good crystallinity, has a saturation magnetization of 135 emu/g, and a coercive cuff of 85
0e, squareness ratio 0.394, specific surface area 18.7m
”/g.
比較例２
ステアリン酸ソーダを用いない以外は実施例２と同様な
実験を行ったところ、黒色微粉末２．５５ｇが得られた
。この粉末は結晶性のよい純粋な六方晶コバルトであっ
たが、飽和磁化１３８ｅｍｕ／ｇ 、保磁力４７５０ｓ
、角形比０．２７０であり、比表面積は６．５＋ｓ”
／ｇであった。Comparative Example 2 An experiment similar to Example 2 was conducted except that sodium stearate was not used, and 2.55 g of black fine powder was obtained. This powder was pure hexagonal cobalt with good crystallinity, and had a saturation magnetization of 138 emu/g and a coercive force of 4750 s.
, the squareness ratio is 0.270, and the specific surface area is 6.5+s”
/g.
実施例５〜９
水酸化コバルト粉末（平均粒径０．１５μ清）４．６５
ｇと前記の分散剤０．０４ｇを用いて、水素を３０Ｋｇ
／ ｄ圧入して反応を行った以外は、実施例２と同様に
処理した。得られた結果を分散剤を用いない比較例３と
共に第１表に示した。尚それぞれに還元された黒色微粉
末は結晶性のよい高純度な六方晶コバルトであった。Examples 5 to 9 Cobalt hydroxide powder (average particle size 0.15μ clear) 4.65
g and 0.04 g of the above dispersant, 30 kg of hydrogen
The process was carried out in the same manner as in Example 2, except that the reaction was carried out by press-fitting the sample. The obtained results are shown in Table 1 together with Comparative Example 3 in which no dispersant was used. The reduced black fine powder was highly purified hexagonal cobalt with good crystallinity.
（本発明の効果〕
本発明の方法によれば、水酸化コバルトを原料として、
純粋な六方晶系で粒径０．０１から１μｍの高純度コバ
ルト六角または多角板状または粒状微粒子が分散した粉
末を高収率で経済的に製造することができる。(Effects of the present invention) According to the method of the present invention, cobalt hydroxide is used as a raw material,
A powder in which highly purified cobalt hexagonal or polygonal plate-like or granular fine particles having a pure hexagonal system and a particle size of 0.01 to 1 μm are dispersed can be economically produced in high yield.
また本発明の方法によれば、飽和磁化が十分に高＜ （
ＬＯＯｅ＋ｍｕ／ｇ以上）、且、保磁力が適当な値（５
００から１，５０００ｅ ）を有する新規な六方晶高
純度コバルト板状または粒状粒子（粒径０．０１かう１
μｍ）を含有する有用な磁性粉、特に垂直磁気記録媒体
用に適当な磁性粉が容易に製造されるものである。Furthermore, according to the method of the present invention, the saturation magnetization is sufficiently high < (
LOOe+mu/g or more), and the coercive force is an appropriate value (5
Novel hexagonal high-purity cobalt plate-like or granular particles (particle size 0.01 to 1
.mu.m), useful magnetic powders, particularly magnetic powders suitable for perpendicular magnetic recording media, can be easily produced.
第１表
例 分散剤 飽和磁化保磁力 角形
比（ｅ＋ｎｕ／ｇ） （Ｏｅ）Table 1 Example Dispersant Saturation coercivity Squareness ratio (e+nu/g) (Oe)
Claims (3)
ルトを分散剤の存在下に水を反応媒体として、１５０か
ら３００℃で水素加圧下に直接液相水素還元することを
特徴とする六方晶コバルト微粒子から成る磁性粉の製造
法。(1) A method for producing cobalt magnetic powder, which comprises directly reducing cobalt hydroxide with liquid phase hydrogen under hydrogen pressure at 150 to 300°C in the presence of a dispersant and using water as a reaction medium. A method for producing magnetic powder consisting of crystalline cobalt fine particles.
ｍの六方晶コバルト六角または多角板状または粒状微粒
子である特許請求の範囲第１項記載の方法。(2) The particle size of hexagonal cobalt fine particles is 0.01 to 1μ
The method according to claim 1, wherein the hexagonal cobalt particles are hexagonal cobalt hexagonal or polygonal plate-like or granular fine particles.
して好適に使用しうるものである特許請求の範囲第１項
もしくは第２項に記載の方法。(3) The method according to claim 1 or 2, wherein the obtained magnetic powder can be suitably used as a magnetic material for perpendicular magnetic recording media.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63089252A JPH01261804A (en) | 1988-04-13 | 1988-04-13 | Manufacture of magnetic hexagonal-cobalt powder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63089252A JPH01261804A (en) | 1988-04-13 | 1988-04-13 | Manufacture of magnetic hexagonal-cobalt powder |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH01261804A true JPH01261804A (en) | 1989-10-18 |
Family
ID=13965568
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63089252A Pending JPH01261804A (en) | 1988-04-13 | 1988-04-13 | Manufacture of magnetic hexagonal-cobalt powder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01261804A (en) |
-
1988
- 1988-04-13 JP JP63089252A patent/JPH01261804A/en active Pending
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