JPH0461302A - Metal magnetic particle powder mainly made of spindle type iron - Google Patents
Metal magnetic particle powder mainly made of spindle type ironInfo
- Publication number
- JPH0461302A JPH0461302A JP2173871A JP17387190A JPH0461302A JP H0461302 A JPH0461302 A JP H0461302A JP 2173871 A JP2173871 A JP 2173871A JP 17387190 A JP17387190 A JP 17387190A JP H0461302 A JPH0461302 A JP H0461302A
- Authority
- JP
- Japan
- Prior art keywords
- particles
- axis diameter
- spindle
- iron
- metal magnetic
- 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
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 title claims abstract description 120
- 239000006249 magnetic particle Substances 0.000 title claims abstract description 87
- 229910052751 metal Inorganic materials 0.000 title claims abstract description 58
- 239000002184 metal Substances 0.000 title claims abstract description 58
- 229910052742 iron Inorganic materials 0.000 title claims abstract description 56
- 239000000843 powder Substances 0.000 title claims abstract description 43
- 230000005415 magnetization Effects 0.000 claims abstract description 20
- 229910052796 boron Inorganic materials 0.000 claims abstract description 11
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 6
- 229910052725 zinc Inorganic materials 0.000 claims abstract description 6
- 229910052749 magnesium Inorganic materials 0.000 claims abstract description 5
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 5
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 4
- 229910052698 phosphorus Inorganic materials 0.000 claims abstract description 4
- 239000002245 particle Substances 0.000 abstract description 145
- 238000007254 oxidation reaction Methods 0.000 abstract description 29
- 230000003647 oxidation Effects 0.000 abstract description 20
- 239000000203 mixture Substances 0.000 abstract description 2
- 239000000463 material Substances 0.000 abstract 1
- 229920006395 saturated elastomer Polymers 0.000 abstract 1
- 229910052598 goethite Inorganic materials 0.000 description 68
- AEIXRCIKZIZYPM-UHFFFAOYSA-M hydroxy(oxo)iron Chemical compound [O][Fe]O AEIXRCIKZIZYPM-UHFFFAOYSA-M 0.000 description 68
- 239000007789 gas Substances 0.000 description 50
- XBDQKXXYIPTUBI-UHFFFAOYSA-N dimethylselenoniopropionate Natural products CCC(O)=O XBDQKXXYIPTUBI-UHFFFAOYSA-N 0.000 description 22
- 238000000034 method Methods 0.000 description 21
- 239000000725 suspension Substances 0.000 description 21
- 239000007864 aqueous solution Substances 0.000 description 20
- 238000006722 reduction reaction Methods 0.000 description 17
- 230000009467 reduction Effects 0.000 description 15
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 13
- 229910052760 oxygen Inorganic materials 0.000 description 13
- 239000001301 oxygen Substances 0.000 description 13
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 12
- 239000003513 alkali Substances 0.000 description 12
- 230000000052 comparative effect Effects 0.000 description 12
- 239000002244 precipitate Substances 0.000 description 12
- 239000000243 solution Substances 0.000 description 12
- 230000007423 decrease Effects 0.000 description 11
- 238000004519 manufacturing process Methods 0.000 description 11
- 235000019260 propionic acid Nutrition 0.000 description 11
- IUVKMZGDUIUOCP-BTNSXGMBSA-N quinbolone Chemical compound O([C@H]1CC[C@H]2[C@H]3[C@@H]([C@]4(C=CC(=O)C=C4CC3)C)CC[C@@]21C)C1=CCCC1 IUVKMZGDUIUOCP-BTNSXGMBSA-N 0.000 description 11
- 150000003839 salts Chemical class 0.000 description 11
- 230000001747 exhibiting effect Effects 0.000 description 10
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical compound [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 description 10
- 239000007858 starting material Substances 0.000 description 10
- 238000010438 heat treatment Methods 0.000 description 9
- 229910052595 hematite Inorganic materials 0.000 description 9
- 239000011019 hematite Substances 0.000 description 9
- LIKBJVNGSGBSGK-UHFFFAOYSA-N iron(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Fe+3].[Fe+3] LIKBJVNGSGBSGK-UHFFFAOYSA-N 0.000 description 9
- 229910001854 alkali hydroxide Inorganic materials 0.000 description 8
- 150000008044 alkali metal hydroxides Chemical class 0.000 description 8
- 238000006243 chemical reaction Methods 0.000 description 8
- 238000000635 electron micrograph Methods 0.000 description 8
- 238000007796 conventional method Methods 0.000 description 7
- 238000011049 filling Methods 0.000 description 7
- JXKPEJDQGNYQSM-UHFFFAOYSA-M sodium propionate Chemical compound [Na+].CCC([O-])=O JXKPEJDQGNYQSM-UHFFFAOYSA-M 0.000 description 7
- 235000010334 sodium propionate Nutrition 0.000 description 7
- 239000004324 sodium propionate Substances 0.000 description 7
- 229960003212 sodium propionate Drugs 0.000 description 7
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 6
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 6
- 230000032683 aging Effects 0.000 description 6
- 238000002156 mixing Methods 0.000 description 6
- 239000011248 coating agent Substances 0.000 description 5
- 238000000576 coating method Methods 0.000 description 5
- 150000001875 compounds Chemical class 0.000 description 5
- 239000013078 crystal Substances 0.000 description 5
- 150000002736 metal compounds Chemical class 0.000 description 5
- 230000005070 ripening Effects 0.000 description 5
- 239000012266 salt solution Substances 0.000 description 5
- 238000005245 sintering Methods 0.000 description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 5
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 4
- 230000008859 change Effects 0.000 description 4
- TZWGXFOSKIHUPW-UHFFFAOYSA-L cobalt(2+);propanoate Chemical compound [Co+2].CCC([O-])=O.CCC([O-])=O TZWGXFOSKIHUPW-UHFFFAOYSA-L 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 230000004907 flux Effects 0.000 description 4
- 230000001590 oxidative effect Effects 0.000 description 4
- 239000011164 primary particle Substances 0.000 description 4
- 238000010301 surface-oxidation reaction Methods 0.000 description 4
- 239000011701 zinc Substances 0.000 description 4
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 description 3
- 239000011790 ferrous sulphate Substances 0.000 description 3
- 235000003891 ferrous sulphate Nutrition 0.000 description 3
- 229910000359 iron(II) sulfate Inorganic materials 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 239000011777 magnesium Substances 0.000 description 3
- 239000002923 metal particle Substances 0.000 description 3
- 238000012545 processing Methods 0.000 description 3
- 238000003756 stirring Methods 0.000 description 3
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 2
- 238000002441 X-ray diffraction Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 2
- 239000010931 gold Substances 0.000 description 2
- 229910052737 gold Inorganic materials 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 150000002505 iron Chemical class 0.000 description 2
- 229910000015 iron(II) carbonate Inorganic materials 0.000 description 2
- 239000003973 paint Substances 0.000 description 2
- BWHMMNNQKKPAPP-UHFFFAOYSA-L potassium carbonate Chemical compound [K+].[K+].[O-]C([O-])=O BWHMMNNQKKPAPP-UHFFFAOYSA-L 0.000 description 2
- 230000002265 prevention Effects 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 239000010902 straw Substances 0.000 description 2
- 230000002195 synergetic effect Effects 0.000 description 2
- 238000009423 ventilation Methods 0.000 description 2
- XDWXRAYGALQIFG-UHFFFAOYSA-L zinc;propanoate Chemical compound [Zn+2].CCC([O-])=O.CCC([O-])=O XDWXRAYGALQIFG-UHFFFAOYSA-L 0.000 description 2
- WRIDQFICGBMAFQ-UHFFFAOYSA-N (E)-8-Octadecenoic acid Natural products CCCCCCCCCC=CCCCCCCC(O)=O WRIDQFICGBMAFQ-UHFFFAOYSA-N 0.000 description 1
- YIWGJFPJRAEKMK-UHFFFAOYSA-N 1-(2H-benzotriazol-5-yl)-3-methyl-8-[2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidine-5-carbonyl]-1,3,8-triazaspiro[4.5]decane-2,4-dione Chemical compound CN1C(=O)N(c2ccc3n[nH]nc3c2)C2(CCN(CC2)C(=O)c2cnc(NCc3cccc(OC(F)(F)F)c3)nc2)C1=O YIWGJFPJRAEKMK-UHFFFAOYSA-N 0.000 description 1
- KNDAEDDIIQYRHY-UHFFFAOYSA-N 2-[4-[2-(2,3-dihydro-1H-inden-2-ylamino)pyrimidin-5-yl]-3-(piperazin-1-ylmethyl)pyrazol-1-yl]-1-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)ethanone Chemical compound C1C(CC2=CC=CC=C12)NC1=NC=C(C=N1)C=1C(=NN(C=1)CC(=O)N1CC2=C(CC1)NN=N2)CN1CCNCC1 KNDAEDDIIQYRHY-UHFFFAOYSA-N 0.000 description 1
- JVKRKMWZYMKVTQ-UHFFFAOYSA-N 2-[4-[2-(2,3-dihydro-1H-inden-2-ylamino)pyrimidin-5-yl]pyrazol-1-yl]-N-(2-oxo-3H-1,3-benzoxazol-6-yl)acetamide Chemical compound C1C(CC2=CC=CC=C12)NC1=NC=C(C=N1)C=1C=NN(C=1)CC(=O)NC1=CC2=C(NC(O2)=O)C=C1 JVKRKMWZYMKVTQ-UHFFFAOYSA-N 0.000 description 1
- LQJBNNIYVWPHFW-UHFFFAOYSA-N 20:1omega9c fatty acid Natural products CCCCCCCCCCC=CCCCCCCCC(O)=O LQJBNNIYVWPHFW-UHFFFAOYSA-N 0.000 description 1
- QSBYPNXLFMSGKH-UHFFFAOYSA-N 9-Heptadecensaeure Natural products CCCCCCCC=CCCCCCCCC(O)=O QSBYPNXLFMSGKH-UHFFFAOYSA-N 0.000 description 1
- ATRRKUHOCOJYRX-UHFFFAOYSA-N Ammonium bicarbonate Chemical compound [NH4+].OC([O-])=O ATRRKUHOCOJYRX-UHFFFAOYSA-N 0.000 description 1
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 1
- 238000004438 BET method Methods 0.000 description 1
- BCZXFFBUYPCTSJ-UHFFFAOYSA-L Calcium propionate Chemical compound [Ca+2].CCC([O-])=O.CCC([O-])=O BCZXFFBUYPCTSJ-UHFFFAOYSA-L 0.000 description 1
- -1 Co Inorganic materials 0.000 description 1
- FEWJPZIEWOKRBE-JCYAYHJZSA-N Dextrotartaric acid Chemical compound OC(=O)[C@H](O)[C@@H](O)C(O)=O FEWJPZIEWOKRBE-JCYAYHJZSA-N 0.000 description 1
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- ZQPPMHVWECSIRJ-UHFFFAOYSA-N Oleic acid Natural products CCCCCCCCC=CCCCCCCCC(O)=O ZQPPMHVWECSIRJ-UHFFFAOYSA-N 0.000 description 1
- 239000005642 Oleic acid Substances 0.000 description 1
- 206010037660 Pyrexia Diseases 0.000 description 1
- FEWJPZIEWOKRBE-UHFFFAOYSA-N Tartaric acid Natural products [H+].[H+].[O-]C(=O)C(O)C(O)C([O-])=O FEWJPZIEWOKRBE-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 238000005273 aeration Methods 0.000 description 1
- 239000001099 ammonium carbonate Substances 0.000 description 1
- 235000012501 ammonium carbonate Nutrition 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 235000010331 calcium propionate Nutrition 0.000 description 1
- 239000004330 calcium propionate Substances 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 150000001735 carboxylic acids Chemical class 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 229910001882 dioxygen Inorganic materials 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 229960002089 ferrous chloride Drugs 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 230000020169 heat generation Effects 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- NMCUIPGRVMDVDB-UHFFFAOYSA-L iron dichloride Chemical compound Cl[Fe]Cl NMCUIPGRVMDVDB-UHFFFAOYSA-L 0.000 description 1
- 229910021506 iron(II) 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
- QXJSBBXBKPUZAA-UHFFFAOYSA-N isooleic acid Natural products CCCCCCCC=CCCCCCCCCC(O)=O QXJSBBXBKPUZAA-UHFFFAOYSA-N 0.000 description 1
- CQQJGTPWCKCEOQ-UHFFFAOYSA-L magnesium dipropionate Chemical compound [Mg+2].CCC([O-])=O.CCC([O-])=O CQQJGTPWCKCEOQ-UHFFFAOYSA-L 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- ZQPPMHVWECSIRJ-KTKRTIGZSA-N oleic acid Chemical compound CCCCCCCC\C=C/CCCCCCCC(O)=O ZQPPMHVWECSIRJ-KTKRTIGZSA-N 0.000 description 1
- 229910000027 potassium carbonate Inorganic materials 0.000 description 1
- BWILYWWHXDGKQA-UHFFFAOYSA-M potassium propanoate Chemical compound [K+].CCC([O-])=O BWILYWWHXDGKQA-UHFFFAOYSA-M 0.000 description 1
- 235000010332 potassium propionate Nutrition 0.000 description 1
- 239000004331 potassium propionate Substances 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 229910000029 sodium carbonate Inorganic materials 0.000 description 1
- 239000006228 supernatant Substances 0.000 description 1
- 239000011975 tartaric acid Substances 0.000 description 1
- 235000002906 tartaric acid Nutrition 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
Landscapes
- Paints Or Removers (AREA)
- Magnetic Record Carriers (AREA)
- Hard Magnetic Materials (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、高密度記録用を目的とする高出力特性及び低
ノイズレベルを有する磁性粒子粉末として最適である軸
比（長軸径：短軸径）が大きく、粒度が均斉であって、
樹枝状粒子が混在しておらず、しかも、結晶子サイズが
小さく、適当な大きさの比表面積であって、且つ、高い
保磁力と適当な大きさの飽和磁化を有し、酸化安定性に
優れている紡錘形を呈した鉄を主成分とする金属磁性粒
子粉末に関するものである。Detailed Description of the Invention [Industrial Field of Application] The present invention is directed to an axial ratio (long axis diameter: short The axial diameter) is large, the particle size is uniform,
It does not contain dendritic particles, has a small crystallite size, has an appropriate specific surface area, has a high coercive force and an appropriate saturation magnetization, and has good oxidation stability. This invention relates to metal magnetic particles whose main component is iron and exhibits an excellent spindle shape.
近年、ビデオ用、オーディオ用の磁気記録再生用機器の
長時間記録化、小型軽量化が激化しており、特に、昨今
におけるＶＴＲ（ビデオ・テープ・レコーダー）の普及
は目覚ましく、長時間記録化並びに小型軽量化を目指し
たＶＴＲの開発が盛んに行われている。一方においては
、磁気記録媒体である磁気テープに対する高性能化、高
密度記録化の要求が益々高まってきている。In recent years, magnetic recording and playback devices for video and audio have become increasingly compact and lightweight. VTRs are being actively developed with the aim of making them smaller and lighter. On the other hand, demands for higher performance and higher recording density for magnetic tape, which is a magnetic recording medium, are increasing.
即ち、磁気記録媒体の高画像画質、高出力特性、殊に周
波数特性の向上及びノイズレベルの低下が要求され、そ
の為には、残留磁束密度８「の向上、高保磁力化並びに
、分散性、充填性、テープ表面の平滑性の向上が必要で
あり、益＝ Ｓ／Ｎ比の向上が要求されてきている。In other words, magnetic recording media are required to have high image quality, high output characteristics, especially improved frequency characteristics, and lower noise levels. It is necessary to improve the filling properties and the smoothness of the tape surface, and there is a demand for an improvement in the S/N ratio.
磁気記録媒体のこれらの緒特性は磁気記録媒体に使用さ
れる磁性粒子粉末と密接な関係を有するものであるが、
近年においては、従来の酸化鉄磁性粒子粉末に比較して
高い保磁力と大きな飽和磁化を有する鉄を主成分とする
金属磁性粒子粉末が注目され、ディジタｌレオーディオ
テーブ（ＤＡＴ ）、８■−ビデオテープ、Ｈｉ−８テ
ープ並びにヒ゛デオフロッピー等の磁気記録媒体に使用
され実用化されている。しかしながら、これらの鉄を主
成分とする金属磁性粒子粉末についても更に特性改善が
強く望まれている。These characteristics of magnetic recording media are closely related to the magnetic particles used in magnetic recording media.
In recent years, metal magnetic particles whose main component is iron, which have higher coercive force and larger saturation magnetization than conventional iron oxide magnetic particles, have attracted attention, and have been published in Digital Audiotapes (DAT), 8. It has been put to practical use in magnetic recording media such as video tapes, Hi-8 tapes, and video floppies. However, there is a strong desire to further improve the characteristics of these metal magnetic particles whose main component is iron.
今、磁気記録媒体の緒特性と使用される磁性粒子粉末の
特性との関係について詳述すれば次の通りである。The relationship between the characteristics of the magnetic recording medium and the characteristics of the magnetic particles used will now be detailed as follows.
ビデオ用磁気記録媒体として高画像画質を得る為には、
日経エレクトロニクス（１９７６年）５月３日号第８２
〜１０５頁の記載からも明らかな通り、■ビデオＳ／Ｎ
比、■クロマＳ／Ｎ比、■ビデオ周波数特性の向上が要
求される。In order to obtain high image quality as a magnetic recording medium for video,
Nikkei Electronics (1976) May 3rd issue No. 82
~As is clear from the description on page 105, ■Video S/N
Improvements are required in the ratio, (1) chroma S/N ratio, and (2) video frequency characteristics.
ビデオＳ／Ｎ比の向上をはかる為には、磁性粒子粉末の
微粒子化及びその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こと、並びに、磁気記録媒
体の表面平滑性を改良することが重要である。In order to improve the video S/N ratio, it is necessary to make the magnetic particles finer, improve their dispersibility in the vehicle, improve their orientation and filling properties in the coating film, and improve the surface of the magnetic recording medium. It is important to improve smoothness.
即ち、ビデオＳ／Ｎ比の向上を計る一つの方法としては
磁気記録媒体に起因するノイズレベルを低下させること
が重要であり、そのためには、上記記載から明らかなよ
うに使用される磁性粒子粉末の粒子サイズを微細化する
方法が有効であることが知られている。That is, as one method for improving the video S/N ratio, it is important to reduce the noise level caused by the magnetic recording medium, and for this purpose, as is clear from the above description, it is necessary to reduce the magnetic particle powder used. It is known that a method of reducing the particle size of is effective.
磁性粒子粉末の粒子サイズを表す一つの方法として粒子
粉末の比表面積の値がしばしば用いられるが、磁気記録
媒体に起因するノイズレベルは使用される磁性粒子粉末
の比表面積が大きくなる程低くなる傾向にあることも一
般的に知られているところである。The value of the specific surface area of the magnetic particles is often used as one way to express the particle size of the magnetic particles, but the noise level caused by the magnetic recording medium tends to decrease as the specific surface area of the magnetic particles used increases. It is also generally known that there are
この現象は、例えば特開昭５８−１５９２３１号公報の
「第１図ｊ等に示されている。「第１図」は金属磁性粒
子粉末を用いて得られる磁気テープにおける粒子の比表
面積とノイズレベルとの関係を示す図であり、粒子の比
表面積が大きくなる程ノイズレベルは直線的に低下して
いる。This phenomenon is shown, for example, in ``Figure 1 j'' of JP-A No. 58-159231. ``Figure 1'' shows the specific surface area of particles and noise in a magnetic tape obtained using metal magnetic particle powder. It is a diagram showing the relationship with the level, and the noise level decreases linearly as the specific surface area of particles increases.
従って、ビデオＳ／Ｎ比の向上をはかり、ノイズレベル
を低下させる為には、磁性粒子粉末の比表面積が出来る
だけ大きいことが要求されている。Therefore, in order to improve the video S/N ratio and reduce the noise level, it is required that the specific surface area of the magnetic particles be as large as possible.
しかしながら、磁性粒子粉末の比表面積があまりにも大
きくなると、磁性粒子の単位表面積当たりのバインダー
量が減り、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を上げることが困難となり、表
面平滑性が得られなくなるのでビデオＳ／Ｎ比が低下す
る原因となり、−概に磁性粒子粉末の比表面積のみを大
きくすることはかえって好ましく無い場合もある。その
為、磁性粒子粉末のビークル中への分散技術との兼ね合
わせて最適な大きさの比表面積を選ぶことが重要となっ
てくる。However, if the specific surface area of the magnetic particles becomes too large, the amount of binder per unit surface area of the magnetic particles decreases, which increases the dispersibility of the magnetic particles in the vehicle, the orientation and filling properties in the coating film. This makes it difficult to obtain surface smoothness, which causes a decrease in the video S/N ratio.In general, it may not be preferable to increase only the specific surface area of the magnetic particles. Therefore, it is important to select an optimal specific surface area in consideration of the dispersion technology of the magnetic particles in the vehicle.
一方、金属磁性粒子粉末のノイズに関して言えば、金属
磁性粒子粉末の結晶子サイズとも関係があることが知ら
れている。On the other hand, regarding the noise of metal magnetic particles, it is known that there is a relationship with the crystallite size of the metal magnetic particles.
この現象は、例えば「総合電子リサーチ発行、ｒｌ気記
録媒体総合責料集」 （昭和６０年８月１５日）の第１
２３頁」の「図３８ｊ等に示されている。This phenomenon can be seen, for example, in the first article of ``Comprehensive Collection of Recording Media Responsibilities, Published by Sogo Denshi Research'' (August 15, 1985).
38j etc. on page 23.
「図３８」は鉄を主成分とする金属磁性粒子粉末を用い
て得られる磁気テープにおける粒子の結晶子サイズとノ
イズの相関を示す図であり、粒子の結晶子サイズが小さ
くなる程ノイズが小さくなることを示している。"Figure 38" is a diagram showing the correlation between particle crystallite size and noise in a magnetic tape obtained using metal magnetic particle powder containing iron as a main component. The smaller the particle crystallite size, the smaller the noise. It shows what will happen.
従って、磁気記録媒体に起因するノイズレベルを低下さ
せる為には、金属磁性粒子の結晶子サイズを出来るだけ
小さくすることも有効な手段である。Therefore, in order to reduce the noise level caused by the magnetic recording medium, it is an effective means to reduce the crystallite size of the metal magnetic particles as much as possible.
上述した通り、ビデオＳ／Ｎ比の向上をはかり、ノイズ
レベルを低下させる為には、磁性粒子粉末の結晶子サイ
ズが出来るだけ小さく、しかも、適当な大きさの比表面
積、殊に、３０〜６０ｒｒｆ／ｇ程度を有し、且つ、粒
度が均斉であり、樹枝状粒子が混在していないことによ
って、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が要求されている
。As mentioned above, in order to improve the video S/N ratio and reduce the noise level, the crystallite size of the magnetic particles should be as small as possible, and the specific surface area should be an appropriate size, especially 30~ 60rrf/g, the particle size is uniform, and dendritic particles are not mixed, so the magnetic particle powder has excellent dispersibility in the vehicle, orientation in the coating film, and filling property. It is required that the
次に、クロマＳ／Ｈの向上を図る為には、磁気記録媒体
の表面性の改良、配向度の改良が重要であり、その為に
は分散性、配向性の良い磁性粒子粉末がよく、そのよう
な磁性粒子粉末としては、軸比（長軸径：短軸径）が大
きく、粒度が均斉であって、樹枝状粒子が混在しておら
ず、しかも、適当な大きさの比表面積を有していること
が要求される。Next, in order to improve chroma S/H, it is important to improve the surface properties and degree of orientation of the magnetic recording medium, and for this purpose, magnetic particle powder with good dispersibility and orientation is recommended. Such magnetic particles must have a large axial ratio (long axis diameter: short axis diameter), uniform particle size, no dendritic particles, and a specific surface area of an appropriate size. You are required to have one.
更に、ビデオ周波数特性の向上を図る為には、磁気記録
媒体の保磁力Ｈｃが高く、且つ、残留磁束密度Ｂｒが大
きいことが必要である。Furthermore, in order to improve the video frequency characteristics, it is necessary that the magnetic recording medium has a high coercive force Hc and a high residual magnetic flux density Br.
磁気記録媒体の保磁力Ｈｃを高める為には、磁性粒子粉
末の保磁力）１ｃができるだけ高いことが要求されてお
り、現在、ビデオフロッピー用、ＤＡＴ用、８−−ビデ
オ用、Ｈｉ−８用等に使用される磁性粒子粉末の保磁力
は、１３０００ｅ〜１７０００ｃ程度が要求されている
。In order to increase the coercive force Hc of a magnetic recording medium, it is required that the coercive force (1c) of magnetic particles is as high as possible. The coercive force of magnetic particles used in such applications is required to be approximately 13,000e to 17,000c.
磁性粒子粉末の保磁力は、一般にはその形状異方性に起
因して生じる為粒子の軸比（長軸径：短軸径）が大きく
なる程保磁力は増加する傾向にあるが、一方、結晶子サ
イズが小さくなる程保磁力は小さくなる傾向にある為、
上述したビデオＳ／Ｎ比の向上をはかる目的でノイズレ
ベルを低下させる為に結晶子サイズを小さくすると、保
磁力が低下し、ビデオ周波数特性を向上させることが困
難となる。従って、磁性粒子粉末の保磁力を出来るだけ
高く維持しながら、小さい結晶子サイズを有する磁性粒
子粉末が強く要求されている。The coercive force of magnetic particles is generally caused by its shape anisotropy, so the coercive force tends to increase as the axial ratio (major axis diameter: minor axis diameter) of the particles increases. Since the coercive force tends to decrease as the crystallite size decreases,
If the crystallite size is reduced in order to reduce the noise level in order to improve the video S/N ratio as described above, the coercive force decreases, making it difficult to improve the video frequency characteristics. Therefore, there is a strong need for magnetic particles having a small crystallite size while maintaining the coercive force of the magnetic particles as high as possible.
残留磁束密度Ｂｒを上げる為には、磁性粒子粉末の飽和
磁化σＳが出来るだけ大きいことが必要であり、また、
磁性粒子粉末のビークル中での分散性、塗膜中での配向
性及び充填性に依存している。In order to increase the residual magnetic flux density Br, it is necessary that the saturation magnetization σS of the magnetic particle powder is as large as possible, and
It depends on the dispersibility of the magnetic particles in the vehicle, the orientation and filling properties in the coating film.
鉄を主成分とする金属磁性粒子粉末は、前述した通り、
酸化鉄磁性粒子粉末に比較して大きな飽和磁化を有する
ものであるが、１μ麟以下の非常に微細な粒子である為
、粒子の表面活性が非常に大きく、還元後に表面酸化し
て酸化被膜を形成した後、空気中に取り出したとしても
、空気中の酸素と反応して、大幅な磁気特性、殊に飽和
磁化の低下を来たすことになる。また、これを塗料化し
て磁気記録媒体として塗布した後においても磁気記録媒
体の飽和磁束密度Ｂｍ、残留磁束密度Ｂｒが、時間とと
もに劣化する原因となる。飽和磁化の低下は、鉄を主成
分とする金属磁性粒子粉末が微粒子化する程大きくなる
傾向にある。従って、磁性粒子粉末の微粒子化が急激に
進んでいる昨今においては、飽和磁化の大きさと酸化安
定性のバランスがとれていることが強く要求されており
、還元後の鉄を主成分とする金属磁性粒子粉末の表面酸
化方法は重要な課題となっている。As mentioned above, the metal magnetic particle powder whose main component is iron is
It has a larger saturation magnetization than iron oxide magnetic particles, but since it is a very fine particle of less than 1 μm, the surface activity of the particle is very high, and after reduction, the surface oxidizes and forms an oxide film. Even if it is taken out into the air after being formed, it will react with oxygen in the air, resulting in a significant decrease in magnetic properties, especially saturation magnetization. Further, even after this is made into a paint and applied as a magnetic recording medium, the saturation magnetic flux density Bm and residual magnetic flux density Br of the magnetic recording medium deteriorate over time. The decrease in saturation magnetization tends to increase as the metal magnetic particles containing iron as a main component become finer. Therefore, in these days when magnetic particles are rapidly becoming finer, there is a strong demand for a balance between the size of saturation magnetization and oxidation stability. The surface oxidation method of magnetic particles has become an important issue.
鉄を主成分とする金属磁性粒子粉末は、一般に、出発原
料であるゲータイト粒子、これを加熱脱水して得られる
ヘマタイト粒子、又はこれらに鉄以外の異種金属を含有
する粒子を還元性ガス中、加熱還元することにより得ら
れている。Metal magnetic particles containing iron as a main component are generally produced by combining goethite particles as a starting material, hematite particles obtained by heating and dehydrating these particles, or particles containing a different metal other than iron in a reducing gas. It is obtained by heating reduction.
従来、出発原料であるゲータイト粒子粉末を製造する方
法としては、第一鉄塩水溶液に当量以上の水酸化アルカ
リ水溶液を加えて得られる水酸化第一鉄を含む懸濁液を
ｐ）１１１以上にて８０℃以下の温度で酸素含有ガスを
通気して酸化反応を行うことにより針状ゲータイト粒子
を生成させる方法、及び、第一鉄塩水溶液と炭酸アルカ
リ水溶液又は炭酸アルカリ・水酸化アルカリ水溶液とを
反応させて得られたＦｅＣ０，又はＦｅ含存沈澱物を含
む懸濁液に酸素含有ガスを通気して酸化反応を行うこと
により紡錘状を呈したゲータイト粒子を生成させる方法
等が知られている。Conventionally, as a method for producing goethite particle powder, which is a starting material, a suspension containing ferrous hydroxide obtained by adding an equivalent or more aqueous alkali hydroxide solution to a ferrous salt aqueous solution is mixed with p) 111 or more. A method of generating acicular goethite particles by conducting an oxidation reaction by passing an oxygen-containing gas at a temperature of 80° C. or lower, and a method of producing acicular goethite particles using a ferrous salt aqueous solution and an alkali carbonate aqueous solution or an alkali carbonate/alkali hydroxide aqueous solution. A method is known in which spindle-shaped goethite particles are produced by carrying out an oxidation reaction by passing an oxygen-containing gas through a suspension containing FeCO obtained by the reaction or a Fe-containing precipitate. .
軸比（長軸径：短軸径）が大きく、粒度が均斉であって
、樹枝状粒子が混在しておらず、しかも結晶子サイズが
小さく、適当な大きさの比表面積と高い保磁力を有して
いる鉄を主成分とする金属磁性粒子粉末は、現在、最も
要求されているところであるが、前述公知方法のうち前
者の方法によって得られた針状晶ゲータイト粒子は、軸
比（長軸径：短軸径）が１０以上と大きいものであるが
、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とは言い難く、該針状晶ゲータ
イト粒子を加熱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、軸比（長軸径：短軸径）が大きいこと
によって高い保磁力を有するものではあるが、樹枝状粒
子が混在しており、均斉な粒度を有したものとは言い難
い。The axial ratio (long axis diameter: short axis diameter) is large, the particle size is uniform, there are no dendritic particles mixed in, the crystallite size is small, and it has an appropriate specific surface area and high coercive force. At present, metal magnetic particles containing iron as a main component are most in demand, but the acicular goethite particles obtained by the former known method have a low axial ratio (length). Although it has a large axis diameter (short axis diameter) of 10 or more, it contains dendritic particles, and in terms of particle size,
It is difficult to say that the particles have a uniform particle size, and the metal magnetic particles whose main component is iron obtained by thermal reduction of the acicular goethite particles have an axial ratio (major axis diameter: minor axis diameter). Although it has a high coercive force due to its large size, it is difficult to say that it has a uniform particle size because dendritic particles are mixed therein.
前述公知方法のうち後者の方法によって得られた紡錘形
を呈したゲータイト粒子は、粒度が均斉であり、また、
樹枝状粒子が混在していない粒子ではあるが、一方、軸
比（長軸径：短軸径）の大きな粒子が生成し難いという
欠点があり、殊に、この現象は生成粒子の長袖径が小さ
くなる程顕著になるという傾向にある。この紡錘形を呈
したゲータイト粒子を加熱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、粒度が均斉であり、また、
樹枝状粒子が混在していないことによってビークル中に
おける分散性、塗膜中での配向性及び充填性が優れたも
のではあるが、軸比（長軸径：短軸径）が小さい為高い
保磁力を持つ粒子を得ることが困難であるという欠点を
有している。The spindle-shaped goethite particles obtained by the latter method among the above-mentioned known methods have uniform particle size, and
Although these particles do not contain dendritic particles, they have the disadvantage that particles with a large axial ratio (major axis diameter: short axis diameter) are difficult to generate. It tends to become more noticeable as it gets smaller. The metal magnetic particles whose main component is iron obtained by heating and reducing these spindle-shaped goethite particles have uniform particle size, and
Although the absence of dendritic particles allows for excellent dispersibility in the vehicle, orientation and filling properties in the coating film, the small axial ratio (major axis diameter: minor axis diameter) results in high retention. It has the disadvantage that it is difficult to obtain particles with magnetic force.
更に、後述のような軸比改良の検討により比較的高い保
磁力を持つ粒子も得られるようになっているが、これら
の粒子は、その結晶子サイズが大きいという欠点を有し
ている。粒度が均斉であって、樹枝状粒子が混在してお
らず、しかも、高い保磁力を持ちながら、結晶子サイズ
が小さく、且つ、適当な大きさの比表面積を有する鉄を
主成分とする金属磁性粒子は、未だ得られていない。Furthermore, studies on improving the axial ratio as described below have made it possible to obtain particles with a relatively high coercive force, but these particles have the drawback of large crystallite size. A metal whose main component is iron, which has uniform particle size, does not contain dendritic particles, has a high coercive force, has a small crystallite size, and has an appropriate specific surface area. Magnetic particles have not yet been obtained.
従来、粒度が均斉であり、樹枝状粒子が混在しておらず
、しかも、高い保磁力を有する紡錘形を呈した鉄を主成
分とする金Ｉｌｉ磁性粒子粉末を得る為、紡錘形を呈し
たゲータイト粒子の軸比（長軸径：短軸径）を大きくす
る方法が種々試みられており、例えば、特開昭５９−２
３２９２２号公報、特開昭６０−２１３０７号公報、特
開昭６０−２１８１９号公報、特開昭６０−３６６０３
号公報及び特開平２−５１４２９号公報に記載の方法が
あるが、これらの方法により得られた紡錘形を呈した鉄
を主成分とする金属磁性粒子粉末は、後出図２及び図３
に示す通り、結晶子サイズが小さく、適当な大きさの比
表面積と高い保磁力を有する粒子であるとは言い難い。Conventionally, spindle-shaped goethite particles were used to obtain spindle-shaped gold Ili magnetic particles whose main component was iron, which had uniform particle size, no dendritic particles, and high coercive force. Various methods have been attempted to increase the axial ratio (long axis diameter: short axis diameter) of
32922, JP 60-21307, JP 60-21819, JP 60-36603
There are methods described in Japanese Patent Application Laid-open No. 2-51429 and spindle-shaped metal magnetic particles mainly composed of iron obtained by these methods as shown in FIGS. 2 and 3 below.
As shown in the figure, the crystallite size is small, and it is difficult to say that the particles have an appropriate specific surface area and a high coercive force.
そこで、本発明は、軸比（長軸径：短軸径）が大きく、
粒度が均斉であって樹枝状粒子が混在しておらず、しか
も、結晶子サイズが小さく、適当な大きさの比表面積で
あって、高い保磁力と大きな飽和磁化を有し、且つ、酸
化安定性に優れている紡錘形を呈した鉄を主成分とする
金属磁性粒子粉末を得ることを技術的課題とする。Therefore, the present invention has a large axial ratio (long axis diameter: short axis diameter),
It has a uniform grain size and no dendritic particles, a small crystallite size, an appropriate specific surface area, a high coercive force and a large saturation magnetization, and is oxidation stable. The technical problem is to obtain spindle-shaped metal magnetic particles mainly composed of iron, which have excellent properties.
〔課題を解決する為の手段］
前記技術的課題は、次の通りの本発明によって達成でき
る。[Means for Solving the Problems] The above technical problems can be achieved by the present invention as follows.
即ち、本発明は、長軸径０．０５〜０．４０μ■、結晶
子サイズ１１０〜１８０人であって、比表面積が３０〜
６０ｒｒｒ／ｇであり、且つ、保磁力Ｈｃが１３００〜
１７０００ｅであって、飽和磁化σｓが１００〜１４０
ｅｍｕ／ｇであるＮｉ、＾１、Ｓｉ、 Ｐ 、 Ｃｏ
、Ｍｇ、 Ｂ及びＺｎから選ばれた元素の１種又は２種
以上を含有している紡錘形を呈した鉄を主成分とする金
属磁性粒子粉末である。That is, the present invention has a major axis diameter of 0.05 to 0.40μ, a crystallite size of 110 to 180, and a specific surface area of 30 to 30.
60rrr/g, and coercive force Hc is 1300~
17000e, and the saturation magnetization σs is 100 to 140
emu/g Ni, ^1, Si, P, Co
, Mg, B, and Zn, and is spindle-shaped metal magnetic particle powder mainly composed of iron.
先ず、本発明において最も重要な点は、本発明に係る長
軸径０．０５〜０．４０μｍ、結晶子サイズ１１０〜１
８０人であって、比表面積が３０〜６０ぼたであり、且
つ、保磁力ｌ（Ｃが１３００〜１７０００ｅであって、
飽和磁化σＳが１００〜１４０ ｅ＋ｗｕ／ｇである鉄
を主成分とする金属磁性粒子粉末は、軸比（長軸径：短
軸径）が大きく、粒度が均斉であって樹枝状粒子が混在
しておらず、しかも、結晶子サイズが小さく、適当な大
きさの比表面積であって、且つ、高い保磁力と大きな飽
和磁化を有し、酸化安定性に優れている紡錘形を呈した
鉄を主成分とする金属磁性粒子粉末であるという事実で
ある。First, the most important point in the present invention is that the major axis diameter of the present invention is 0.05 to 0.40 μm and the crystallite size is 110 to 1
80 people, the specific surface area is 30 to 60 volts, and the coercive force l (C is 1300 to 17000e,
Metal magnetic particle powder mainly composed of iron with a saturation magnetization σS of 100 to 140 e+wu/g has a large axial ratio (long axis diameter: short axis diameter), uniform particle size, and contains dendritic particles. It mainly consists of spindle-shaped iron, which has a small crystallite size, an appropriate specific surface area, high coercive force, large saturation magnetization, and excellent oxidation stability. The fact is that it is a metal magnetic particle powder as a component.
本発明に係る紡錘形を呈した鉄を主成分とする金属磁性
粒子粉末は、炭酸アルカリ水溶液又は炭酸アルカリ・水
酸化アルカリ水溶液と第一鉄塩水溶液とを反応させて得
られたＰｅＣＯ５又はＰｅ含有沈澱物を含む懸濁液を非
酸化性雰囲気において熟成した後、該ＦｅＣＯ２又はＰ
ｅ含有沈澱物を含む懸濁液中に酸素含有ガスを通気して
酸化することにより紡錘形を呈したゲータイト粒子粉末
を生成させるにあたり、前記炭酸アルカリ水溶液、前記
炭酸アルカリ・水酸化アルカリ水溶液、前記第−鉄塩水
溶液及び酸素含有ガスを通気して酸化する前の前記ｐｅ
ｃＯｓ又はＦｅ含有沈澱物を含む懸濁液のいずれかに、
あらかじめプロピオン酸又はその塩を存在させておくこ
とにより紡錘形を呈したゲータイト粒子を生成させ、必
要により該紡錘形を呈したゲータイト粒子又は、該紡錘
形を呈したゲータイト粒子を加熱脱水して得られた紡錘
形を呈したヘマタイト粒子をＮｉ、＾Ｉ、 Ｓｔ、 Ｐ
、 Ｃｏ、、Ｍｇ、 Ｂ及びＺｎから選ばれる金属化
合物の少なくとも１種で被着処理し、次いで、被着処理
をしていないか若しくは被着処理をしている上記紡錘形
を呈したゲータイト粒子又は、これら粒子を非還元性雰
囲気中、３００〜８００°Ｃの温度範囲で加熱処理を行
って得られた紡錘形を呈したヘマタイト粒子を還元性ガ
ス中で加熱還元して紡錘形を呈した鉄を主成分とする金
属磁性粒子とした後、該紡錘形を呈した鉄を主成分とす
る金属磁性粒子を酸素含有ガスとＮ２ガスとの混合ガス
雰囲気中３０〜２００°Ｃの温度範囲で積極的に表面酸
化処理することによって得ることができる。The spindle-shaped metal magnetic particle powder containing iron as a main component according to the present invention is obtained by reacting an aqueous alkali carbonate solution or an alkali carbonate/alkali hydroxide solution with an aqueous ferrous salt solution, such as PeCO5 or a Pe-containing precipitate. After aging the suspension containing FeCO2 or P in a non-oxidizing atmosphere,
In producing spindle-shaped goethite particle powder by passing an oxygen-containing gas into the suspension containing the e-containing precipitate for oxidation, the alkali carbonate aqueous solution, the alkali carbonate/alkali hydroxide aqueous solution, the alkali carbonate/alkali hydroxide aqueous solution, the - the pe before being oxidized by passing through an aqueous iron salt solution and an oxygen-containing gas;
either to a suspension containing cOs or a Fe-containing precipitate;
Goethite particles exhibiting a spindle shape are produced by pre-existing propionic acid or a salt thereof, and if necessary, the goethite particles exhibiting the spindle shape or the spindle shape obtained by heating and dehydrating the goethite particles exhibiting the spindle shape. Hematite particles exhibiting Ni, ^I, St, P
, Co, Mg, B, and Zn, and then the spindle-shaped goethite particles or The spindle-shaped hematite particles obtained by heat-treating these particles at a temperature range of 300 to 800°C in a non-reducing atmosphere are heated and reduced in a reducing gas to produce mainly spindle-shaped iron. After forming the metal magnetic particles as a component, the spindle-shaped metal magnetic particles mainly composed of iron are actively surface-treated in a mixed gas atmosphere of oxygen-containing gas and N2 gas in a temperature range of 30 to 200°C. It can be obtained by oxidation treatment.
本発明において、軸比（長軸径：短軸径）の大きな紡錘
形を呈したゲータイト粒子が得られる理由について、本
発明者は、後出の比較例に示す通り、プロピオン酸又は
その塩を存在させずに熟成のみを行った場合、熟成を行
わずにプロピオン酸又はその塩を存在させた場合のいず
れの場合にも軸比（長軸径：短軸径）の大きな紡錘形を
呈したゲータイト粒子が得られないことから、熟成工程
とプロピオン酸又はその塩との相乗効果によるものと考
えている。In the present invention, the reason why spindle-shaped goethite particles with a large axial ratio (major axis diameter: minor axis diameter) are obtained is that the present inventors explained that propionic acid or its salt is present as shown in the comparative example below. Goethite particles exhibiting a spindle shape with a large axial ratio (major axis diameter: minor axis diameter) in both cases, when only ripening is performed without ripening, and when propionic acid or its salt is present without ripening. This is thought to be due to the synergistic effect of the aging process and propionic acid or its salt.
本発明において、結晶子サイズが小さいにもかかわらず
適当な大きさの比表面積と高い保磁力を有する鉄を主成
分とする金属磁性粒子粉末が得られる理由について、本
発明者は下記のように考えている。In the present invention, the reason why iron-based magnetic metal particles having an appropriate specific surface area and high coercive force despite having a small crystallite size can be obtained is as follows. thinking.
従来、炭酸アルカリ水溶液又は炭酸アルカリ・水酸化ア
ルカリ水溶液と第一鉄塩水溶液とを反応させて得られた
ＰｅＣＯ２又はＦｅ含有沈澱物を含む懸濁液を得た後、
該ＦｅＣＯ５又はＦｅ含有沈澱物を含む懸濁液中に酸素
含有ガスを通気して酸化することにより得られた紡錘形
を呈したゲータイト粒子は、電子顕微鏡で注意深く観察
すると、細長い１次粒子が藁を束ねたような結晶成長を
しており、１次粒子の個数が増えることによりゲータイ
ト粒子の粒子の幅方向が大きく成長する為に軸比（長軸
径：短軸径）の小さい紡錘形を呈したゲータイト粒子が
得られ易い。Conventionally, after obtaining a suspension containing PeCO2 or Fe-containing precipitate obtained by reacting an aqueous alkali carbonate solution or an aqueous alkali carbonate/alkali hydroxide solution with an aqueous ferrous salt solution,
When the spindle-shaped goethite particles obtained by oxidizing the FeCO5 or Fe-containing precipitate-containing suspension by passing an oxygen-containing gas through the suspension, careful observation with an electron microscope reveals that elongated primary particles form straw. The crystals grow in a bundled manner, and as the number of primary particles increases, the width direction of the goethite particles grows larger, resulting in a spindle shape with a small axial ratio (major axis diameter: minor axis diameter). Goethite particles are easily obtained.
しかも、該紡錘形を呈したゲータイト粒子を通常の方法
で、焼結防止処理を施して還元性ガス中で加熱処理を行
うことによって金属磁性粒子粉末を得た場合、前記藁を
束ねたような細長いＩ次粒子間の結晶成長が進むため、
得られた金属磁性粒子粉末の結晶子サイズは、Ｆｅ （
ＯＨ） ｔの酸化反応によって得られた針状のゲータイ
トを出発原料とした金属磁性粒子粉末の結晶子サイズに
比較して大きい値のものしか得られていない。Moreover, when the spindle-shaped goethite particles are subjected to sintering prevention treatment and heated in a reducing gas to obtain metal magnetic particles, the spindle-shaped goethite particles become elongated like bundles of straw. Because crystal growth between primary particles progresses,
The crystallite size of the obtained metal magnetic particle powder was Fe (
Only crystallite sizes larger than those of metal magnetic particles using acicular goethite obtained by the oxidation reaction of OH) t as a starting material have been obtained.
一方、本発明における紡錘形を呈したゲータイト粒子は
、熟成工程とプロピオン酸又はその塩との相乗効果に起
因して、粒子の幅方向をせばめることか出来ることによ
って軸比（長軸径：短軸径）が向上しており、粒子成長
過程でゲータイト粒子の幅方向の成長を制御することに
よって還元時の一次粒子の幅方向の成長が抑えられ、そ
の結果、結晶子サイズが小さくなったものと考えられ今
、本発明者が行った数多くの実験例からその一部を抽出
して説明すれば、以下の通りである。On the other hand, the goethite particles exhibiting a spindle shape in the present invention have an axial ratio (major axis diameter: short axis diameter) due to the synergistic effect of the aging process and propionic acid or its salt. By controlling the growth of goethite particles in the width direction during the particle growth process, the growth of the primary particles in the width direction during reduction is suppressed, resulting in a smaller crystallite size. Considering this, some of the many experimental examples conducted by the present inventor will be extracted and explained as follows.
図１は、プロピオン酸ナトリウムの存在量と紡錘形を呈
したゲータイト粒子の軸比（長軸径：短軸径）との関係
を示したものである。FIG. 1 shows the relationship between the amount of sodium propionate present and the axial ratio (long axis diameter: short axis diameter) of spindle-shaped goethite particles.
即ち、プロピオン酸ナトリウムをＦｅに対し０〜１０．
０モル％を存在させた以外は、後出実施例１、実施例５
及び実施例７の各実施例と同様にして得れた紡錘形を呈
したゲータイト粒子の軸比（長軸径：短軸径）とプロピ
オン酸ナトリウムの存在量との関係を示したものである
。That is, sodium propionate is 0 to 10.
Example 1 and Example 5 described below except that 0 mol% was present.
The graph shows the relationship between the axial ratio (long axis diameter: short axis diameter) of spindle-shaped goethite particles obtained in the same manner as in each example of Example 7 and the amount of sodium propionate present.
図１中、曲線Ａ、Ｂ及びＣは、それぞれ長軸径０．３〜
０．５μ−程度、長軸径０．２μ蒙程度及び長軸径０．
１ μ−程度の紡錘形を呈したゲータイト粒子粉末であ
る。In FIG. 1, curves A, B, and C each have a major axis diameter of 0.3 to
0.5 μm, major axis diameter approximately 0.2 μm, and major axis diameter 0.5 μm.
It is a goethite particle powder exhibiting a spindle shape of about 1 μm.
図１から明らかな通り、プロピオン酸ナトリウムの存在
量が増加する程得られる紡錘形を呈したゲータイト粒子
の軸比（長軸径：短軸径）が大きくなる１頃向にある。As is clear from FIG. 1, as the amount of sodium propionate increases, the axial ratio (long axis diameter: short axis diameter) of the resulting spindle-shaped goethite particles increases, which is around 1.
従来、炭酸アルカリ水溶液と第一鉄塩水溶液とを反応さ
せて得られたＦｅＣＯ５を含む懸濁液中に酸素含有ガス
を通気して酸化することにより紡錘形を呈したゲータイ
ト粒子粉末を生成させる方法において、クエン酸、酒石
酸等のカルボン酸及びその塩を存在させるものとして特
開昭５０−８０９９９号公報に開示の方法があるが、こ
の場合には、「紡錘状から球状に近い回転ダ円体の粒子
が得られる。」なる記載の通り、軸比（長軸径：短軸径
）の小さいゲータイト粒子が得られており、本発明にお
けるプロピオン酸又はその塩の作用、効果とは全く相違
するものである。Conventionally, in a method of producing spindle-shaped goethite particle powder by passing an oxygen-containing gas through a suspension containing FeCO5 obtained by reacting an aqueous alkali carbonate solution and an aqueous ferrous salt solution to oxidize the suspension. There is a method disclosed in JP-A-50-80999 in which carboxylic acids such as citric acid, tartaric acid, and their salts are present, but in this case, "a rotating spherical body with a shape ranging from a spindle shape to a shape close to a sphere" is used. Goethite particles with a small axial ratio (major axis diameter: minor axis diameter) are obtained, which is completely different from the action and effect of propionic acid or its salt in the present invention. It is.
図２は、紡錘形を呈した鉄を主成分とする金属磁性粒子
粉末のＢＥＴ比表面積と結晶子サイズとの関係を示した
ものである。FIG. 2 shows the relationship between the BET specific surface area and the crystallite size of spindle-shaped metal magnetic particles whose main component is iron.
図２中、Δ印及び×印は、いずれも従来法により得られ
た紡錘形を呈した鉄を主成分とする金属磁性粒子粉末で
あり、それぞれ、前出特開昭６０−３６６０３号公報及
び前出特開平２−５１４２９号公報に記載する方法によ
り得られた鉄を主成分とする金属磁性粒子粉末である。In FIG. 2, the marks Δ and × are spindle-shaped metal magnetic particle powders containing iron as a main component obtained by the conventional method, respectively. This is a metal magnetic particle powder containing iron as a main component obtained by the method described in JP-A-2-51429.
また、○印は、本発明に係る紡錘形を呈した鉄を主成分
とする金属磁性粒子粉末である。In addition, the symbol ◯ indicates the spindle-shaped metal magnetic particle powder containing iron as a main component according to the present invention.
本発明に係る紡錘形を星した鉄を主成分とする金属磁性
粒子粉末は、従来法により得られた紡錘形を呈した鉄を
主成分とする金属磁性粒子粉末に比べ結晶子サイズが小
さいにもかかわらず適当な大きさの比表面積を有するも
のである。Although the spindle-shaped star metal magnetic particle powder of the present invention is mainly composed of iron, the crystallite size is smaller than that of the spindle-shaped metal magnetic particle powder mainly composed of iron obtained by conventional methods. First, it has a specific surface area of an appropriate size.
図３は、紡錘形を呈した鉄を主成分とする金属磁性粒子
粉末の保磁力と結晶子サイズとの関係を示したものであ
る。FIG. 3 shows the relationship between the coercive force and the crystallite size of spindle-shaped metal magnetic particles whose main component is iron.
図３中、△印及びＸ印は、いずれも従来法により得られ
た紡錘形を呈した鉄を主成分とする金属磁性粒子粉末で
あり、それぞれ、前出特開昭６０−３６６０３号公報及
び前出特開平２−５１４２９号公報に記載する方法によ
り得られた鉄を主成分とする金属磁性粒子粉末である。In FIG. 3, marks △ and This is a metal magnetic particle powder containing iron as a main component obtained by the method described in JP-A-2-51429.
また、Ｏ印は、本発明に係る紡錘形を呈した鉄を主成分
とする金属磁性粒子粉末である。Further, the symbol O indicates a spindle-shaped metal magnetic particle powder containing iron as a main component according to the present invention.
本発明に係る紡錘形を呈した金属磁性粒子粉末は、従来
法により得られた紡錘形を呈した鉄を主成分とする金属
粒子粉末に比べ、結晶子サイズが小さいにもかかわらず
高い保磁力を有するものである。The spindle-shaped metal magnetic particles according to the present invention have a higher coercive force despite having a smaller crystallite size than the spindle-shaped metal particles mainly composed of iron obtained by conventional methods. It is something.
一般に、結晶子サイズ、比表面積等は還元条件、出発原
料の粒子サイズ等に依存して、その値が変わるものであ
るが、図２及び図３から分るように、従来法により得ら
れた紡錘形を呈したゲータイト粒子を出発原料とした場
合、還元条件等によってそのバランスをとることが困難
であることが分る。In general, the values of crystallite size, specific surface area, etc. change depending on the reduction conditions, particle size of the starting material, etc., but as can be seen from Figures 2 and 3, the values obtained by the conventional method When spindle-shaped goethite particles are used as a starting material, it is found that it is difficult to maintain a balance depending on reduction conditions and the like.
次に、本発明の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.
本発明において使用される第一鉄塩水溶液としては、硫
酸第一鉄水溶液、塩化第−鉄水溶液等がある。Examples of the ferrous salt aqueous solution used in the present invention include a ferrous sulfate aqueous solution and a ferrous chloride aqueous solution.
本発明における炭酸アルカリ水溶液としては、炭酸ナト
リウム、炭酸カリウム、炭酸アンモニウム等の水溶液が
、水酸化アルカリ水溶液としては、水酸化ナトリウム、
水酸化カリウム等の水溶液を使用することができる。Examples of the aqueous alkali carbonate solution in the present invention include aqueous solutions of sodium carbonate, potassium carbonate, ammonium carbonate, etc.; examples of the aqueous alkali hydroxide solution include sodium hydroxide,
Aqueous solutions such as potassium hydroxide can be used.
本発明における熟成は、Ｎエガス等の不活性ガスを液中
に通気することにより不活性雰囲気下において行い、ま
た、当該通気ガスや機械的操作等により撹拌しながら行
う。Aging in the present invention is carried out in an inert atmosphere by passing an inert gas such as N gas into the liquid, and is carried out while stirring using the aeration gas or mechanical operation.
本発明におけるＦｅＣＯ３又はＰｅ含有沈澱物を含む懸
濁液の熟成温度は３５〜６０°Ｃ１熟成時間は５０〜５
００分間である。In the present invention, the aging temperature of the suspension containing FeCO3 or Pe-containing precipitate is 35 to 60°C, and the aging time is 50 to 50°C.
00 minutes.
３５℃未満の場合には、軸比（長軸径：短軸径）が小さ
くなり、目的とする軸比（長軸径−短軸径）の大きい紡
錘形を呈したゲータイト粒子粉末が得られない。６０℃
を越える場合にも、目的とする軸比（長軸径：短軸径）
の大きい紡錘形を呈したゲータイト粒子粉末を得ること
ができるが、必要以上に熟成温度を上げる意味がない。If the temperature is lower than 35°C, the axial ratio (long axis diameter: short axis diameter) will be small, and it will not be possible to obtain spindle-shaped goethite particles with the desired axial ratio (long axis diameter - short axis diameter). . 60℃
Even when exceeding the target axial ratio (major axis diameter: short axis diameter)
Although it is possible to obtain goethite particles having a large spindle shape, there is no point in raising the ripening temperature more than necessary.
５０分間未満である場合には、目的とする軸比（長軸径
：短軸径）の大きい紡錘形を呈したゲータイト粒子粉末
が得られない、５００分間を越える場合にも、目的とす
る軸比（長軸径：短軸径）の大きい紡錘形を呈したゲー
タイト粒子粉末を得ることができるが、必要以上に長時
間にする意味がない。If the time is less than 50 minutes, spindle-shaped goethite particles with a large desired axial ratio (long axis diameter: short axis diameter) cannot be obtained; if the time exceeds 500 minutes, the desired axial ratio cannot be obtained. Although it is possible to obtain goethite particle powder exhibiting a spindle shape with a large (major axis diameter: minor axis diameter), there is no point in making the process longer than necessary.
本発明におけるｐＨは７〜１１である。７未満、又は１
１を越える場合には、紡錘形を呈したゲータイト粒子粉
末を得ることができない。The pH in the present invention is 7-11. less than 7 or 1
If it exceeds 1, it is impossible to obtain spindle-shaped goethite particles.
本発明のゲータイト生成反応の酸化時における反応温度
は、３５〜７０°Ｃである。３５℃未満である場合には
、目的とする軸比（長軸径：短軸径）の大きい紡錘形を
呈したゲータイト粒子粉末を得ることができない。The reaction temperature during oxidation of the goethite production reaction of the present invention is 35 to 70°C. If the temperature is less than 35° C., goethite particles having a spindle shape with a desired axial ratio (long axis diameter: short axis diameter) cannot be obtained.
７０℃を越える場合には、紡錘形を呈したゲータイト粒
子中に粒状へマタイト粒子粉末が混在してく る。When the temperature exceeds 70°C, granular hematite particles become mixed in the spindle-shaped goethite particles.
本発明のゲータイト生成反応の酸化時における酸化手段
は、酸素含有ガス（例えば空気）を液中に通気すること
により行い、また、当該通気ガスや機械的操作等により
撹拌しながら行う。The oxidation means during the oxidation of the goethite production reaction of the present invention is carried out by aerating an oxygen-containing gas (for example, air) into the liquid, and is carried out while stirring by the aerating gas or mechanical operation.
本発明におけるプロピオン酸又はその塩は、生成する紡
錘形を呈したゲータイト粒子の軸比（長軸径：短軸径）
及び短軸径に関与するものであるから、酸素含有ガスを
通気して酸化する前の段階で反応中に存在させておく必
要があり、炭酸アルカリ水溶液、炭酸アルカリ・水酸化
アルカリ水溶液、第−鉄塩水溶液及び酸素含有ガスを通
気して酸化する前のＦｅＣ０，又はＰｅ含有沈澱物を含
む懸濁液のいずれかの段階で存在さゼることかできる。In the present invention, propionic acid or its salt has an axial ratio (long axis diameter: short axis diameter) of spindle-shaped goethite particles to be produced.
Since it is involved in the short axis diameter and short axis diameter, it is necessary to make it present in the reaction at a stage before oxidation by aerating oxygen-containing gas. It can be present at any stage in the suspension containing the FeC0 or Pe-containing precipitate before oxidation by passing an aqueous iron salt solution and an oxygen-containing gas through it.
本発明におけるプロピオン酸の塩としては、プロピオン
酸ナリトウム、プロピオン酸カリウム、プロピオン酸カ
ルシウム、プロピオン酸亜鉛、プロピオン酸コバルト、
プロピオン酸マグネシウＬ等を使用することができる。Salts of propionic acid in the present invention include sodium propionate, potassium propionate, calcium propionate, zinc propionate, cobalt propionate,
Magnesium propionate L and the like can be used.
本発明におけるプロピオン酸又はその塩の存在量は、Ｆ
ｅに対し０．１〜１０，０モル％の範囲である。The amount of propionic acid or its salt in the present invention is F
It is in the range of 0.1 to 10.0 mol% with respect to e.
０．１モル％未満である場合には、目的とする軸比（長
軸径：短軸径）の大きい紡錘形を呈したゲータイト粒子
粉末を得ることができない、 ｉｏ、ｏモル％を越える
場合にも、目的とする軸比（長軸径：短軸径）の大きい
紡錘形を呈したゲータイト粒子粉末を得ることができる
が、必要以上に添加する意味がない。If the amount is less than 0.1 mol%, it is impossible to obtain goethite particles having a spindle shape with a large axial ratio (major axis diameter: minor axis diameter).If it exceeds io, o mol%, Although it is also possible to obtain spindle-shaped goethite particles with a desired axial ratio (major axis diameter: minor axis diameter), there is no point in adding more than necessary.
本発明において、加熱還元時の粒子形状のくずれ及び粒
子間の焼結を防止する為に、あらかじめ出発原料をＮｉ
、 Ａｌ、Ｓｉ、、Ｐ 、、Ｃｏ、 Ｊｉｇ、、Ｂ及び
Ｚｎから選ばれる金属化合物の少なくとも１種で被着処
理を施すことが好ましい、これらの金属化合物は焼結防
止効果を有するだけでなく、還元速度を制御する働きも
有するので、必要に応じて組み合わせて使用することが
好ましい。In the present invention, in order to prevent deformation of the particle shape and sintering between particles during thermal reduction, the starting material is made of Ni in advance.
, Al, Si, , P , , Co, Jig, , B, and Zn. These metal compounds not only have a sintering prevention effect but also , also has the function of controlling the reduction rate, so it is preferable to use them in combination as necessary.
上記金属化合物で被着処理を施した出発原料は、そのま
ま還元しても目的とする鉄を主成分とする金属磁性粒子
粉末を得ることができるが、磁気特性、粉体特性のコン
トロール及び形状のコントロールの為には、常法により
、還元に先立って、あらかじめ、非還元性ガス雰囲気中
において加熱処理を施しておくことが好ましい。The starting material coated with the above metal compound can be reduced as it is to obtain the desired metal magnetic particle powder whose main component is iron, but it is possible to control the magnetic properties and powder properties, and to control the shape. For control purposes, it is preferable to perform heat treatment in advance in a non-reducing gas atmosphere by a conventional method prior to reduction.
上記非還元性ガス雰囲気中における加熱処理は、空気、
酸素ガス、窒素ガス流下、３００〜８００℃の温度範囲
で行うことができ、該加熱処理温度は、出発原料粒子の
被着処理に用いた金属化合物の神頼に応じて適宜選択す
ることがより好ましい。The heat treatment in the non-reducing gas atmosphere includes air,
It can be carried out under a flow of oxygen gas or nitrogen gas at a temperature in the range of 300 to 800°C, and the heat treatment temperature can be appropriately selected depending on the requirements of the metal compound used for the deposition treatment of the starting material particles. preferable.
８００″Ｃを越える場合には、粒子の変形と粒子及び粒
子相互間の焼結を引き起こしてしまう。If the temperature exceeds 800''C, deformation of the particles and sintering of the particles and each other will occur.
本発明における加熱還元の温度範囲は、３００〜５５０
°Ｃが好ましい。The temperature range of thermal reduction in the present invention is 300 to 550
°C is preferred.
５５０℃を越える場合には、還元反応が急激に進行して
粒子の変形と、粒子及び粒子相互間の焼結を引き起こし
てしまう。If the temperature exceeds 550° C., the reduction reaction rapidly progresses, causing deformation of the particles and sintering of the particles and each other.
３００°Ｃ未満である場合には、還元反応の進行が遅く
、長時間を要する。If the temperature is less than 300°C, the reduction reaction progresses slowly and takes a long time.
本発明における加熱還元後の鉄を主成分とする金属磁性
粒子粉末は、酸素含有ガスとＮ２ガスとの混合ガス雰囲
気中３０〜２００°Ｃの温度範囲で表面酸化処理を施す
ことにより、安定化される。In the present invention, the metal magnetic particles mainly composed of iron after thermal reduction are stabilized by surface oxidation treatment at a temperature range of 30 to 200°C in a mixed gas atmosphere of oxygen-containing gas and N2 gas. be done.
混合ガスの割合は、空気：Ｎ２ガスの比率で１＝１００
０〜ｌ二〇の範囲が好ましく、処理温度との兼ね合いで
適当な混合比率を選べば良い。混合比率が１ ： １０
００未満の低い割合の空気量で処理をしても良いが、酸
化反応の進行が長くなる。The ratio of mixed gas is air:N2 gas ratio 1=100
A range of 0 to 120 is preferable, and an appropriate mixing ratio may be selected in consideration of the processing temperature. Mixing ratio is 1:10
Although the treatment may be performed with a low air amount of less than 0.00, the oxidation reaction will take a long time to proceed.
処理温度が３０”Ｃ未満の場合でも何ら問題はないが、
酸化反応の進行が遅く、処理時間が長くなるので好まし
くない。２００“Ｃを越える場合には、前記混合ガス比
率の場合、酸化反応が過度に進行してしまう為、磁気特
性、殊に、飽和磁化σＳの低下をきたすので好ましくな
い。There is no problem if the processing temperature is less than 30"C, but
This is not preferable because the oxidation reaction progresses slowly and the treatment time becomes long. If the temperature exceeds 200"C, the oxidation reaction proceeds excessively in the case of the above-mentioned mixed gas ratio, resulting in a decrease in magnetic properties, particularly saturation magnetization σS, which is not preferable.
本発明における表面酸化処理方法としては、後出実施例
に示すように、前記混合比率のガスによる酸化反応によ
る発熱がピークに達した後、酸素含有ガスの比率を順次
上げて更に酸化処理を繰り返す方法で多段階に行うこと
が望ましい。In the surface oxidation treatment method of the present invention, as shown in the examples below, after the heat generated by the oxidation reaction by the gas at the above-mentioned mixing ratio reaches its peak, the oxidation treatment is repeated by increasing the ratio of the oxygen-containing gas one after another. It is desirable to carry out the method in multiple steps.
本発明においては、従来から鉄を主成分とする金属磁性
粒子粉末の各種特性の向上の為に、出発原料であるゲー
タイト粒子の生成に際し、通常添加されるＣｏ、 Ｎｉ
、 Ｃｒ、 ＺｎＳＡｌ、ＰＩｎ等のＦｅ以外の異種金
属を添加することができ、この場合にも、本発明の目的
とする軸比（長軸径：短軸径）が大きく、しかも、結晶
子サイズが小さく、適当な大きさの比表面積と高い保磁
力を有しているゲータイト粒子粉末を得ることができる
。In the present invention, in order to improve various properties of metal magnetic particles whose main component is iron, Co and Ni, which are usually added when producing goethite particles as a starting material, are used.
, Cr, ZnSAl, PIn, and other metals other than Fe can be added, and in this case as well, the axial ratio (long axis diameter: short axis diameter) targeted by the present invention is large, and the crystallite size is small. It is possible to obtain goethite particles having a small surface area, an appropriate specific surface area, and a high coercive force.
〔実施例］ 次に、実施例並びに比較例により、本発明を説明する。〔Example] Next, the present invention will be explained with reference to Examples and Comparative Examples.
尚、以下の実施例並びに比較例における粒子の長袖径、
軸比（長軸径：短軸径）は、いずれも電子顕微鏡写真か
ら測定した数値の平均値で示した値であり、また、比表
面積はＢＥＴ法によるＮ２ガス吸着量から測定した値で
示した。In addition, the long sleeve diameter of particles in the following examples and comparative examples,
The axial ratio (long axis diameter: short axis diameter) is the average value of values measured from electron micrographs, and the specific surface area is the value measured from the amount of N2 gas adsorbed by the BET method. Ta.
結晶子サイズは、Ｘ線回折法で測定される結晶粒子の大
きさを（１１０）結晶面に垂直な方向における結晶粒子
の径で表したものであり、その測定は、結晶の（１１０
）面の回折線のラインプロファイルから、下記のシェラ
−の式を用いて計算した値で示した。Crystallite size is the size of crystal grains measured by X-ray diffraction method expressed as the diameter of crystal grains in the direction perpendicular to the (110) crystal plane;
) from the line profile of the diffraction line of the plane using the following Scherrer equation.
β ｃｏｓθ
但し、β＝装置による機械幅を差し引いた真の回折ピー
クの半値幅
に−シェラ一定数（０，９）
λ＝特性Ｘ線の波長
θ＝回折角
酸化安定性は、飽和磁化の経時変化率（％）で示し、温
度４０’Ｃ１相対湿度７０％の雰囲気で、４日間放置し
た後の飽和磁化減少率（％）で示した。β cos θ However, β = half-width of the true diffraction peak after subtracting the mechanical width due to the device - Scherrer constant (0,9) λ = wavelength of characteristic X-ray θ = diffraction angle Oxidation stability is the change in saturation magnetization over time It is expressed as a rate of change (%), and it is expressed as a rate of decrease in saturation magnetization (%) after being left for 4 days in an atmosphere with a temperature of 40'C1 and a relative humidity of 70%.
〈紡錘形を呈したゲータイト粒子粉末の製造シ実施例１
〜９、比較例１〜３；
実施例１
毎秒３．４ｃｍの速度でＮ、ガスを流すことによって非
酸化性雰囲気に保持された反応容器中に、１９４５ｇの
プロピオン酸ナトリウム（Ｆｅに対し５．０モル％に該
当する。）を含む・１．３５ｍｏＩ／ ｌのＮａ 、Ｃ
Ｏ３水溶液６００１を添加した後、Ｆｅ！′１．３５ｓ
＋ｏｌ／ Ｑを含む硫酸第一鉄水溶液３００７！を添加
、混合し、温度５０’ＣにおいてＰｅＣ０，の生成を行
った。<Production of spindle-shaped goethite particle powder Example 1
-9, Comparative Examples 1-3; Example 1 Into a reaction vessel maintained in a non-oxidizing atmosphere by flowing N, gas at a rate of 3.4 cm/sec, 1945 g of sodium propionate (5.5 cm/sec for Fe) was added. 1.35 mol/l of Na, C
After adding O3 aqueous solution 6001, Fe! '1.35s
Ferrous sulfate aqueous solution containing +ol/Q 3007! were added and mixed to generate PeCO, at a temperature of 50'C.
上記ＦｅＣ０ｚを含む懸濁液中に、引き続きＮｔガスを
毎秒３．４０−の速度で吹き込みながら、温度５０℃で
３００分間保持した後、当該ＦｅＣ０，を含む懸濁液中
に、温度５０°Ｃにおいて毎秒２．８０−の速度で空気
を５．５時間通気して黄褐色沈澱粒子を生成させた。The suspension containing FeC0z was kept at a temperature of 50°C for 300 minutes while continuously blowing Nt gas at a rate of 3.40-per second, and then the suspension containing FeC0z was kept at a temperature of 50°C. Air was bubbled through the tube at a rate of 2.80 mm per second for 5.5 hours to form a tan precipitate.
尚、空気通気中におけるｐＨは８．５〜９．５であった
。Note that the pH during air ventilation was 8.5 to 9.5.
黄色褐色沈澱粒子は、常法により、炉別、水洗、乾燥、
粉砕した。The yellow-brown precipitated particles are separated by furnace, washed with water, dried, and
Shattered.
得られた黄褐色粒子粉末は、Ｘ線回折の結果、ゲータイ
トであり、図４に示す電子顕微鏡写真（Ｘ ３００００
）から明らかな通り、平均値で長軸径０．３１μｍ、軸
比（長軸径：短軸径＞１５．８：１の紡錘形を呈した粒
子からなり、粒度が均斉で樹枝状粒子が混在しないもの
であった。As a result of X-ray diffraction, the obtained yellow-brown particles were found to be goethite, and the electron micrograph shown in FIG. 4 (X 30,000
), it consists of spindle-shaped particles with an average major axis diameter of 0.31 μm and an axial ratio (major axis diameter: minor axis diameter > 15.8:1), the particle size is uniform, and dendritic particles are mixed. It was something I wouldn't do.
実施例２〜７、比較例■〜３
ＰｅＣ０３又はＢｅ含有沈澱物の生成反応における炭酸
アルカリ水溶液の種類、濃度及び使用量、水酸化アルカ
リ水溶液の使用の有無、プロピオン酸又はその塩の種類
、蓋及び存在時期、第一鉄塩水溶液の種類、濃度及び使
用量、温度、熟成工程における温度及び時間並びに酸化
工程における温度及び反応時間を種々変化させた以外は
、実施例Ｉと同様にして紡錘形を呈したゲータイト粒子
粉末を得た。Examples 2 to 7, Comparative Examples 1 to 3 Type, concentration, and amount of alkali carbonate aqueous solution used in reaction for producing PeC03 or Be-containing precipitate, presence or absence of use of alkali hydroxide aqueous solution, type of propionic acid or its salt, lid The spindle shape was prepared in the same manner as in Example I, except that the presence period, the type, concentration and amount of the ferrous salt aqueous solution, temperature, temperature and time in the ripening step, and temperature and reaction time in the oxidation step were varied. Goethite particle powder with the following properties was obtained.
この時の主要製造条件及び緒特性を表１及び表２に示す
。The main manufacturing conditions and characteristics at this time are shown in Tables 1 and 2.
実施例２〜７で得られた紡錘形を呈したゲータイト粒子
粉末は、いずれも粒度が均斉で樹枝状粒子が混在しない
ものであった。The spindle-shaped goethite particles obtained in Examples 2 to 7 all had uniform particle sizes and did not contain dendritic particles.
実施例５で得られた紡錘形を呈したゲータイト粒子粉末
の電子顕微鏡写真（ｘ ３００００）を図５に示す。An electron micrograph (x 30,000) of the spindle-shaped goethite particles obtained in Example 5 is shown in FIG.
また、比較例１で得られた紡錘形を呈したゲータイト粒
子粉末は図６の電子顕微鏡写真（ｘ ３００００）に示
される通り、短軸径が大きく、軸比（長軸径：短軸径）
が小さいものであった。In addition, as shown in the electron micrograph (x 30000) of FIG. 6, the spindle-shaped goethite particles obtained in Comparative Example 1 have a large short axis diameter and an axial ratio (long axis diameter: short axis diameter).
was small.
実施例８
２、Ｏｍｏｌ／ｅのＣｏ５０ａ Ｈ７ｎｌｏ水溶液９．
１ ｆｆｉに、撹拌しながら１０．Ｏｗｏｌ／ ｌのＮ
ａＯＨ溶液３．６５１を添加してＣｏ（ＯＨ）よの沈澱
を生成した。このＣｏ （ＯＨ） ｚ沈澱物の上澄液を
できるだけ排出した後、３６．５＊ｏｌのプロピオン酸
を添加して全容積を２５１としたプロピオン酸コバルト
溶液を用意する。Example 8 2. Co50a H7nlo aqueous solution of Omol/e9.
1 ffi, stirring 10. Owol/N of l
3.65 ml of aOH solution was added to form a Co(OH) precipitate. After draining as much of the supernatant liquid of this Co(OH)z precipitate as possible, a cobalt propionate solution is prepared by adding 36.5*ol of propionic acid to make the total volume 251.
毎秒３．４ｃｍの速度で６ガスを流すことによって非酸
化性雰囲気に保持された反応容器中に、１，３５ｍｏｌ
／ｊ！のＮａｇＣＯ＝水溶液６００１を添加した後、Ｆ
ｅ”１．３５層ｏ１／ Ｒを含む硫酸第一鉄水溶液３０
０ ｆを添加、混合し、温度４８℃においてＦｅＣ０ｔ
の生成を行った。1,35 mol into a reaction vessel maintained in a non-oxidizing atmosphere by flowing 6 gases at a rate of 3.4 cm per second.
/j! After adding NagCO=aqueous solution 6001 of F
Ferrous sulfate aqueous solution containing 1.35 layers o1/R 30
0 f was added and mixed, and FeC0t was added at a temperature of 48°C.
was generated.
上記ＦｅＣＯ５を含む懸濁液中、あらかじめ用意した前
記プロピオン酸コバルト溶液を添加する。The cobalt propionate solution prepared in advance is added to the suspension containing FeCO5.
得られたＦｅＣＯ３を含む懸濁液中に、引き続きＮ２ガ
スを毎秒３．４ｃｍの速度で吹き込みながら、温度４８
°Ｃで３００分間保持した後、該ＦｅＣＯ５を含む懸濁
液中に、温度４８℃において毎秒２．８ｃ曽の速度で空
気を５．１時間通気して黄褐色沈澱粒子を生成させた。While continuing to blow N2 gas into the resulting suspension containing FeCO3 at a rate of 3.4 cm/sec, the temperature was increased to 48 cm.
After being held at 0.degree. C. for 300 minutes, air was bubbled through the FeCO.sub.5-containing suspension at a temperature of 48.degree. C. at a rate of 2.8 centimeters per second for 5.1 hours to form yellow-brown precipitated particles.
尚、空気通気中におけるｐＨは８．４〜９．５であった
。Note that the pH during air ventilation was 8.4 to 9.5.
黄褐色沈澱粒子は、常法により、炉別、水洗、乾燥、粉
砕した。The yellow-brown precipitated particles were separated in a furnace, washed with water, dried, and pulverized by a conventional method.
得られた黄褐色粒子粉末は、ｘ１回折の結果、ゲータイ
トであり、平均値で長軸径０．２７μ謹、軸比（長軸径
：短軸径）１４．８：Ｉの紡錘形を呈した粒子からなり
、粒度が均斉で樹枝状粒子が混在しないものであった。As a result of x1 diffraction, the obtained yellow-brown particles were found to be goethite, exhibiting a spindle shape with an average major axis diameter of 0.27μ and an axial ratio (major axis diameter: minor axis diameter) of 14.8:I. It consisted of particles, the particle size was uniform, and dendritic particles were not mixed.
実施例９
プロピオン酸コバルト４゜５ｍｏＩ／ Ｎを使用する代
わりにプロピオン酸亜鉛３．抛０１／ｌを使用した以外
は、実施例８と同様にして紡錘形を呈したゲータイト粒
子粉末を得た。Example 9 Instead of using cobalt propionate 4°5mol/N, zinc propionate 3. Goethite particles having a spindle shape were obtained in the same manner as in Example 8, except that 01/l was used.
この時の主要製造条件及び緒特性を表１及び表２に示す
。The main manufacturing conditions and characteristics at this time are shown in Tables 1 and 2.
実施例９で得られた紡錘形を呈したゲータイト粒子粉末
は、いずれも粒度が均斉で樹枝状粒子が混在しないもの
であった。All of the spindle-shaped goethite particles obtained in Example 9 had a uniform particle size and did not contain dendritic particles.
〈紡錘形を呈したヘマタイト粒子の製造〉実施例１Ｏ〜
１１：
実施例１０〜１１
実施例２及び実施例５で得られた紡錘形を呈したゲータ
イト粒子を空気中３００“Ｃで脱水して紡錘形を呈した
ヘマタイト粒子を得た。<Production of spindle-shaped hematite particles> Example 1O~
11: Examples 10 to 11 The spindle-shaped goethite particles obtained in Examples 2 and 5 were dehydrated in air at 300"C to obtain spindle-shaped hematite particles.
得られたヘマタイト粒子は、電子顕微鏡観察の結果、そ
れぞれ平均値で長軸径が０．３６ｐｍ 、軸比（長軸径
：短軸径）１５．０：ｌ、及び、長軸径０．１８μ■、
軸比（長軸径：短軸径）１１．０：ｌであった。As a result of electron microscopic observation, the obtained hematite particles had an average major axis diameter of 0.36 pm, an axial ratio (major axis diameter: minor axis diameter) of 15.0:l, and a major axis diameter of 0.18 μ. ■,
The axial ratio (long axis diameter: short axis diameter) was 11.0:l.
〈紡錘形を呈したゲータイト粒子粉末の金属化合物によ
る被着処理〉実施例１２〜２０、比較例４〜６；実施例
１２
実施例１で得られた炉別、水洗した紡錘形を呈したゲー
タイト粒子１０Ｋｇ分のプレスケーキを２００！の水中
に懸濁させた。この時の懸濁液のｐＨは９．２であった
。<Adhesion treatment of spindle-shaped goethite particles with a metal compound> Examples 12 to 20, Comparative Examples 4 to 6; Example 12 10 kg of spindle-shaped goethite particles obtained in Example 1, separated by furnace and washed with water. 200 pieces of pressed cake! suspended in water. The pH of the suspension at this time was 9.2.
次いで、上記懸濁液にゲータイトに対し１３．０重量％
となるようにＡＩ（Ｎ（ｈ）ｓ・９Ｈ２０を１．３Ｋｇ
添加し、更に、ゲータイトに対し２３．２重量％となる
ようにＣｏ（ＣＨｚＣＯＯ）ｚ ・４）１２０２．３２
Ｋｇを 添加した後１５分間撹拌した。この時の懸濁液
のｐ）Ｉは４．７０であった。Next, 13.0% by weight of goethite was added to the suspension.
1.3Kg of AI (N(h)s・9H20 so that
Co(CHzCOO)z 4) 1202.32 was added so that the amount was 23.2% by weight based on the goethite.
Kg was added and stirred for 15 minutes. The p)I of the suspension at this time was 4.70.
次いで、上記懸濁液にＮａＯＨを添加してｐＨを９．８
に調整したのち、ゲータイトに対し１．５重量％となる
ようにオレイン酸１５０ｇを添加した後、ロータリーフ
ィルターを用いて６０°Ｃの温水で十分洗浄した後、ゲ
ータイトに対し１５重￥％となるように）ＩＪＯｙを１
．５Ｋｇ添加して２０分間撹拌した。Then, NaOH was added to the above suspension to adjust the pH to 9.8.
After adjusting to 150g of oleic acid to make it 1.5% by weight based on goethite, after thoroughly washing with warm water at 60°C using a rotary filter, the content becomes 15% by weight based on goethite. ) IJOy 1
．． 5 kg was added and stirred for 20 minutes.
更に、フィルタープレスで炉別し、乾燥してＡ１、Ｃｏ
、 Ｂ化合物が被着されたゲータイトを得た。Furthermore, it is separated in a furnace using a filter press and dried to obtain A1, Co
, Goethite coated with B compound was obtained.
得られたゲータイト中のＡ１、Ｃｏ、 Ｂの含有量は、
それぞれ八ｌとして０．８９ｗｔχ、ｃｏは５．３２ｗ
ｔχ、Ｂとし７０．６＋３ｗｔχであった。The contents of A1, Co, and B in the obtained goethite are as follows:
Each 8l is 0.89wtχ, co is 5.32w
tχ, B was 70.6+3wtχ.
実施例１３〜２０、比較例４〜６
被処理粒子の種類、Ａｌ、 Ｓｉ、 Ｐ 、、Ｎｉ、
Ｍｇ、 Ｃｏ。Examples 13-20, Comparative Examples 4-6 Types of particles to be treated: Al, Si, P, Ni,
Mg, Co.
Ｂ及びＺｎ化合物の種類及び添加量を種々変化させて、
実施例１２と同様の方法で金属化合物が被着された紡錘
形を呈したゲータイト粒子を得た。By varying the types and amounts of B and Zn compounds,
Spindle-shaped goethite particles coated with a metal compound were obtained in the same manner as in Example 12.
この時の主要処理条件を表３に示す。Table 3 shows the main processing conditions at this time.
〈紡錘形を呈した鉄を主成分とする金属磁性粒子粉末の
製造〉実施例２１〜３０、比較例７〜９；実施例２１
実施例１２で得られた＾１、Ｃｏ、 Ｂ化合物が被着さ
れた紡錘形を呈したゲータイト粒子粉末５．０Ｋｇを空
気中４００°Ｃで加熱処理してＡｌ、 Ｃｏ、 Ｂ化合
物が被着されている紡錘形を呈したヘマタイト粒子粉末
を得た。<Production of spindle-shaped metal magnetic particles mainly composed of iron> Examples 21 to 30, Comparative Examples 7 to 9; Example 21 The ^1, Co, and B compounds obtained in Example 12 were deposited. 5.0 kg of spindle-shaped goethite particles were heat-treated in air at 400°C to obtain spindle-shaped hematite particles coated with Al, Co, and B compounds.
上記Ａｌ、 Ｃｏ、 Ｂ化合物が被着された紡錘形を呈
したヘマタイト粒子粉末２０００ｇを流動層加熱還元炉
に投入し、Ｈ２ガスを毎分１８０１の割合で通気し、還
元温度３９０°Ｃで１５時時間光した。2000 g of spindle-shaped hematite particles coated with the Al, Co, and B compounds were placed in a fluidized bed heating reduction furnace, H2 gas was passed through at a rate of 1801/min, and the reduction temperature was 390°C for 15 hours. The time was shining.
還元終了後、■！ガスを一旦Ｎ２ガスで置換した後、Ｎ
、ガスを１６ＯＮ １ ／ｗｉｎ流しなから５０°Ｃま
で冷却した。After the reduction,■! After replacing the gas with N2 gas, N
Then, the gas was cooled to 50° C. at a flow rate of 16 ON 1 /win.
次いで、炉温を５０°Ｃに保ちなからＮ□ガス１６ＯＮ
ｌ ／ｗｉｎ中に空気を０．２Ｎ ｌ ／ｗｉｎの割
合で混入した空気ｋｙｔガスの混合ガスを通気した。そ
の混合ガス比率での酸化反応による発熱ピークが観測さ
れた後、空気量を０．４Ｎ ｌ ／ｗｉｎに上げ、混合
ガス中の空気混合比率を増加させた。このようにして、
その混合ガス比率での酸化反応による発熱ピークが観測
された後に混合ガス中の空気の比率を上昇させる方法で
段階的に空気混合比率を上げて、最終的に空気１．２Ｎ
ｌ ／ｗｉｎ、 Ｎ、ガス１６ＯＮ ｌ ／ｗｉｎの
割合の混合ガスで酸化処理を継続し、酸化による発熱が
無くなって、品物の温度が炉温とほぼ同じ約５０℃にな
るまで酸化処理を行った。この間品物の温度は最高７５
°Ｃまで到達した。Next, while keeping the furnace temperature at 50°C, turn on N□ gas for 16 hours.
A mixed gas of air kyt gas mixed with air at a ratio of 0.2Nl/win was vented. After an exothermic peak due to the oxidation reaction at that mixed gas ratio was observed, the air amount was increased to 0.4 Nl/win to increase the air mixing ratio in the mixed gas. In this way,
After the exothermic peak due to the oxidation reaction was observed at that mixed gas ratio, the air mixing ratio was gradually increased by increasing the air ratio in the mixed gas, and finally the air was 1.2N.
The oxidation treatment was continued with a mixed gas at a ratio of 1/win, N, and gas at a ratio of 16ON/win, and the oxidation treatment was performed until the heat generation due to oxidation disappeared and the temperature of the item reached approximately 50°C, which is almost the same as the furnace temperature. . During this time, the temperature of the item will be up to 75
It reached °C.
続いて、炉温を５０°Ｃ，Ｈｚガス流量を１６ＯＮ Ｉ
ｔ ／ｓ＋ｉｎに保ったまま、空気の混合比率を徐々に
上げ、最終的に空気量を２ＯＮ１７ｓｉｎとした。この
間、発熱は観測されなかった。Next, the furnace temperature was set to 50°C, and the Hz gas flow rate was set to 16ON.
The air mixing ratio was gradually increased while maintaining the temperature at t/s+in, and the air amount was finally set to 2ON17sin. No fever was observed during this time.
更に、空気４０ Ｎｌ／ｓｉｎ、 Ｈｚガス１４ＯＮ
ｌ ／ｓｉｎの混合ガスを通気しながら、室温まで冷却
した。Furthermore, air 40Nl/sin, Hz gas 14ON
The mixture was cooled to room temperature while passing a mixed gas of 1/sin.
−旦、空気流量をＯＩ！、／−１ｎとして、ｈガスに置
換した後、このようにして得られた、表面に酸化被膜を
形成した紡錘形を呈した鉄を主成分とする金属粒子粉末
を回収した。-Dan, change the air flow rate! , /-1n, and after replacing with h gas, the thus obtained spindle-shaped metal particle powder mainly composed of iron with an oxide film formed on the surface was collected.
この＾１、Ｃｏ及びＢを含有する鉄を主成分とする金属
磁性粒子粉末は、図７に示す電子顕微鏡写真（Ｘ ３０
０００）から明らかな通り、平均長軸０．２８μｍ、軸
比（長軸径：短軸径）１５．０；ｌ、比表面積４９，２
ｒｄ／ｇ及び結晶子サイズ１５５人であり、粒度が均斉
で柑技状粒子の混在しない微細なものであった。This ^1, metal magnetic particle powder mainly composed of iron containing Co and B can be seen in the electron micrograph (X 30
000), the average major axis is 0.28 μm, the axial ratio (major axis diameter: minor axis diameter) is 15.0; l, and the specific surface area is 49.2
rd/g and crystallite size of 155, the particle size was uniform and fine without any citrus-like particles.
また、磁気特性は、保磁力Ｈｃ １５３００ｅ、飽和磁
化σｓ １３５．４ ｅｍｕ／ｇ 、ΔσＳ／σｓは−
４，２％であった。In addition, the magnetic properties are as follows: coercive force Hc 15300e, saturation magnetization σs 135.4 emu/g, ΔσS/σs -
It was 4.2%.
実施例２２〜３０、比較例７〜９
出発原料の種類、加熱処理温度及び非還元性雰囲気の種
類並びに還元温度及びＨ２流量並びに表面酸化処理条件
を種々変化させた以外は実施例２１と同様にして紡錘形
を呈した鉄を主成分とする金属磁性粒子粉末を得た。Examples 22 to 30, Comparative Examples 7 to 9 Same as Example 21 except that the type of starting material, heat treatment temperature, type of non-reducing atmosphere, reduction temperature, H2 flow rate, and surface oxidation treatment conditions were variously changed. A spindle-shaped metal magnetic particle powder mainly composed of iron was obtained.
この時の主要製造条件及び緒特性を表４に示す。Table 4 shows the main manufacturing conditions and characteristics at this time.
実施例２２乃至３０で得られた紡錘形を呈した鉄を主成
分とする金ｒｌ！磁性粒子粉末は、いずれも、粒度が均
斉で樹枝状粒子が混在しないものであった。The spindle-shaped gold rl mainly composed of iron obtained in Examples 22 to 30! All of the magnetic particles had a uniform particle size and did not contain dendritic particles.
実施例２６で得られた鉄を主成分とする金属磁性粒子粉
末の電子顕微鏡写真（ｘ３００００）を図８に示す。FIG. 8 shows an electron micrograph (x30000) of the metal magnetic particle powder containing iron as a main component obtained in Example 26.
尚、比較例７〜９の各比較例における還元後の鉄を主成
分とする金属磁性粒子粉末は、空気中に取り出した時や
激な酸化を起こさないように、トルエン液中に浸漬して
取り出した。測定の為、−部を取り出し、トルエンを蒸
発させながら表面に安定な酸化被膜を形成した。In addition, in each of Comparative Examples 7 to 9, the reduced metal magnetic particles containing iron as a main component were immersed in a toluene solution to prevent them from being violently oxidized when taken out into the air. I took it out. For measurement, the - portion was taken out and a stable oxide film was formed on the surface while toluene was evaporated.
表
〔発明の効果〕
本発明に係る紡錘形を呈した鉄を主成分とする金属磁性
粒子粉末は、前出実施例に示した通り、軸比（長軸径：
短軸径）が大きく粒度が均斉であフて、樹枝状粒子が混
在しておらず、しかも、結晶子サイズが小さく、適当な
大きさの比表面積であって、且つ、高い保磁力と適当な
大きさの飽和磁化を有し、酸化安定性に優れている紡錘
形を呈した鉄を主成分とする金属磁性粒子粉末であるの
で、高密度記録用、低ノイズレベル用の磁性粒子粉末と
して好適である。Table [Effects of the Invention] As shown in the above-mentioned examples, the spindle-shaped metal magnetic particles powder mainly composed of iron according to the present invention have an axial ratio (major axis diameter:
It has a large short axis diameter), a uniform particle size, no dendritic particles mixed in, a small crystallite size, an appropriate specific surface area, and a high coercive force. It is a spindle-shaped metal magnetic particle powder mainly composed of iron, which has a saturation magnetization of a large size and excellent oxidation stability, so it is suitable as a magnetic particle powder for high-density recording and low noise level. It is.
更に、磁性塗料の製造に際して、本発明に係る鉄を主成
分とする金属磁性粒子粉末を用いた場合には、ビークル
中への分散が良好であり、充填性が極めて優れ、Ｓ／Ｎ
比が大きい好ましい磁気記録媒体を得ることができる。Furthermore, when the metal magnetic particle powder containing iron as a main component according to the present invention is used in the production of magnetic paint, it is well dispersed in the vehicle, has extremely excellent filling properties, and has a low S/N ratio.
A preferable magnetic recording medium with a large ratio can be obtained.
図１は、プロピオン酸ナトリウムの存在量と紡錘形を呈
したゲータイト粒子粉末の軸比（長軸径：短軸径）との
関係を示したものである。
図１中、曲線Ａ、、Ｂ及びＣは、それぞれ、長軸径０３
〜０．５ μ−程度 、長軸径０．２μ−程度、長袖径
０．１ μ−程度の紡錘形を呈したゲータイト粒子粉末
である。
図２は、紡錘形を呈した鉄を主成分とする金属磁性粒子
粉末のＢＥＴ比表面積と結晶子サイズとの関係を示した
ものである。
図２中、△印及びＸ印は、従来法により得られた紡錘形
を呈した鉄を主成分とする金属磁性粒子粉末、○印は、
本発明における鉄を主成分とする金属磁性粒子粉末であ
る。
図３は、紡錘形を呈した鉄を主成分とする金属磁性粒子
粉末の保磁力と結晶子サイズとの関係を示したものであ
る。
図３中、Δ印及びＸ印は、従来法により得られた紡錘形
を呈した鉄を主成分とする金属磁性粒子粉末、０印は、
本発明における鉄を主成分とする金属磁性粒子粉末であ
る。
図４乃至図６は、それぞれ、実施例１、実施例５及び比
較例１で得られた紡錘形を呈したゲルタイト粒子粉末の
粒子構造を示す電子顕微鏡写真（ｘ ３００００）であ
る。
図７及び図８は、実施例２１及び実施例２６で得られた
紡錘形を呈した鉄を主成分とする金属磁性粒子粉末の粒
子構造を示す電子顕微鏡写真（ｘ３０（１００）である
。FIG. 1 shows the relationship between the amount of sodium propionate present and the axial ratio (major axis diameter: minor axis diameter) of spindle-shaped goethite particles. In FIG. 1, curves A, B, and C each have a major axis diameter of 03
It is a goethite particle powder exhibiting a spindle shape with a diameter of about 0.5 .mu.m, a long axis diameter of about 0.2 .mu.m, and a long axis diameter of about 0.1 .mu.m. FIG. 2 shows the relationship between the BET specific surface area and the crystallite size of spindle-shaped metal magnetic particles whose main component is iron. In FIG. 2, △ and
This is a metal magnetic particle powder containing iron as a main component in the present invention. FIG. 3 shows the relationship between coercive force and crystallite size of spindle-shaped metal magnetic particles whose main component is iron. In FIG. 3, marks Δ and X are spindle-shaped metal magnetic particle powders mainly composed of iron obtained by the conventional method, and marks 0 are
This is a metal magnetic particle powder containing iron as a main component in the present invention. 4 to 6 are electron micrographs (x 30,000) showing the particle structure of spindle-shaped geltite particles obtained in Example 1, Example 5, and Comparative Example 1, respectively. FIGS. 7 and 8 are electron micrographs (x30 (100)) showing the particle structure of the spindle-shaped metal magnetic particles mainly composed of iron obtained in Example 21 and Example 26.
Claims (1)
１０〜１８０Åであって、比表面積が３０〜６０ｍ＾２
／ｇであり、且つ、保磁力Ｈｃが１３００〜１７００Ｏ
ｅであって、飽和磁化σｓが１００〜１４０ｅｍｕ／ｇ
であるＮｉ、Ａｌ、Ｓｉ、Ｐ、Ｃｏ、Ｍｇ、Ｂ及びＺｎ
から選ばれた元素の１種又は２種以上を含有している紡
錘形を呈した鉄を主成分とする金属磁性粒子粉末。(1) Major axis diameter 0.05 to 0.40 μm, crystallite size 1
10 to 180 Å and a specific surface area of 30 to 60 m^2
/g, and the coercive force Hc is 1300 to 1700O
e, and the saturation magnetization σs is 100 to 140 emu/g
Ni, Al, Si, P, Co, Mg, B and Zn
A spindle-shaped metal magnetic particle powder whose main component is iron and which contains one or more elements selected from the following.
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17387190A JP3144683B2 (en) | 1990-06-29 | 1990-06-29 | Spindle-shaped iron-based metal magnetic particle powder |
| DE69115579T DE69115579T2 (en) | 1990-06-26 | 1991-06-13 | Magnetic spindle-shaped iron alloy particles and process for their production |
| EP91305339A EP0466338B1 (en) | 1990-06-26 | 1991-06-13 | Spindle-shaped magnetic iron based alloy particles and process for producing the same |
| US08/118,287 US5466306A (en) | 1990-06-26 | 1993-09-09 | Spindle-shaped magnetic iron based alloy particles |
| US08/450,205 US5599378A (en) | 1988-12-22 | 1995-05-25 | Spindle-shaped magnetic iron based alloy particles and process for producing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17387190A JP3144683B2 (en) | 1990-06-29 | 1990-06-29 | Spindle-shaped iron-based metal magnetic particle powder |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0461302A true JPH0461302A (en) | 1992-02-27 |
| JP3144683B2 JP3144683B2 (en) | 2001-03-12 |
Family
ID=15968679
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP17387190A Expired - Lifetime JP3144683B2 (en) | 1988-12-22 | 1990-06-29 | Spindle-shaped iron-based metal magnetic particle powder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3144683B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5951138A (en) * | 1995-09-12 | 1999-09-14 | Enplas Corporation | Surface light source device of side light type |
| US6167182A (en) * | 1996-10-25 | 2000-12-26 | Omron Corporation | Surface light source device and liquid crystal display device, portable telephone and information terminal employing the surface light source device |
| EP1220208A1 (en) * | 2000-12-27 | 2002-07-03 | Toda Kogyo Corporation | Spindle-shaped magnetic alloy particles for magnetic recording, and magnetic recording medium |
| US7901102B2 (en) | 2004-10-22 | 2011-03-08 | Samsung Electronics Co., Ltd. | Backlight unit and liquid crystal display apparatus employing the same |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01156001A (en) * | 1987-12-14 | 1989-06-19 | Um Kogyo:Kk | Shank for saw |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2640817B2 (en) | 1987-10-27 | 1997-08-13 | 戸田工業株式会社 | Spindle-shaped goethite particles and method for producing the same |
-
1990
- 1990-06-29 JP JP17387190A patent/JP3144683B2/en not_active Expired - Lifetime
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01156001A (en) * | 1987-12-14 | 1989-06-19 | Um Kogyo:Kk | Shank for saw |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5951138A (en) * | 1995-09-12 | 1999-09-14 | Enplas Corporation | Surface light source device of side light type |
| US6167182A (en) * | 1996-10-25 | 2000-12-26 | Omron Corporation | Surface light source device and liquid crystal display device, portable telephone and information terminal employing the surface light source device |
| EP1220208A1 (en) * | 2000-12-27 | 2002-07-03 | Toda Kogyo Corporation | Spindle-shaped magnetic alloy particles for magnetic recording, and magnetic recording medium |
| US7901102B2 (en) | 2004-10-22 | 2011-03-08 | Samsung Electronics Co., Ltd. | Backlight unit and liquid crystal display apparatus employing the same |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3144683B2 (en) | 2001-03-12 |
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