JPS63169707A - Manufacture of magnetic powder for magnetic recording medium - Google Patents
Manufacture of magnetic powder for magnetic recording mediumInfo
- Publication number
- JPS63169707A JPS63169707A JP62001098A JP109887A JPS63169707A JP S63169707 A JPS63169707 A JP S63169707A JP 62001098 A JP62001098 A JP 62001098A JP 109887 A JP109887 A JP 109887A JP S63169707 A JPS63169707 A JP S63169707A
- Authority
- JP
- Japan
- Prior art keywords
- powder
- magnetic powder
- magnetic
- dispersant
- oxidizing
- 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
- 230000005291 magnetic effect Effects 0.000 title claims abstract description 52
- 239000006247 magnetic powder Substances 0.000 title claims abstract description 52
- 238000004519 manufacturing process Methods 0.000 title claims description 7
- 230000001590 oxidative effect Effects 0.000 claims abstract description 26
- 239000002270 dispersing agent Substances 0.000 claims abstract description 21
- 239000003960 organic solvent Substances 0.000 claims abstract description 18
- 238000000034 method Methods 0.000 claims abstract description 8
- 238000003756 stirring Methods 0.000 claims description 9
- 239000000843 powder Substances 0.000 abstract description 43
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 abstract description 18
- -1 ester soda salt Chemical class 0.000 abstract description 16
- 230000003647 oxidation Effects 0.000 abstract description 9
- 238000007254 oxidation reaction Methods 0.000 abstract description 9
- 229910001337 iron nitride Inorganic materials 0.000 abstract description 8
- VLKZOEOYAKHREP-UHFFFAOYSA-N n-Hexane Chemical compound CCCCCC VLKZOEOYAKHREP-UHFFFAOYSA-N 0.000 abstract description 6
- IMNFDUFMRHMDMM-UHFFFAOYSA-N N-Heptane Chemical compound CCCCCCC IMNFDUFMRHMDMM-UHFFFAOYSA-N 0.000 abstract description 4
- 239000000344 soap Substances 0.000 abstract description 4
- 150000001338 aliphatic hydrocarbons Chemical class 0.000 abstract description 3
- 150000004945 aromatic hydrocarbons Chemical class 0.000 abstract description 3
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical compound CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 abstract description 2
- 239000013543 active substance Substances 0.000 abstract description 2
- 238000007654 immersion Methods 0.000 abstract description 2
- TVMXDCGIABBOFY-UHFFFAOYSA-N octane Chemical compound CCCCCCCC TVMXDCGIABBOFY-UHFFFAOYSA-N 0.000 abstract description 2
- 239000008096 xylene Substances 0.000 abstract description 2
- QHOWYOKUKZPTPL-KVVVOXFISA-N (z)-octadec-9-enoic acid;potassium Chemical compound [K].CCCCCCCC\C=C/CCCCCCCC(O)=O QHOWYOKUKZPTPL-KVVVOXFISA-N 0.000 abstract 1
- ZQCUDFIHJAXGTP-KVVVOXFISA-N (z)-octadec-9-enoic acid;sodium Chemical compound [Na].CCCCCCCC\C=C/CCCCCCCC(O)=O ZQCUDFIHJAXGTP-KVVVOXFISA-N 0.000 abstract 1
- 150000001450 anions Chemical class 0.000 abstract 1
- 239000006185 dispersion Substances 0.000 abstract 1
- 238000004090 dissolution Methods 0.000 abstract 1
- 125000003438 dodecyl group Chemical group [H]C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])* 0.000 abstract 1
- 239000007788 liquid Substances 0.000 abstract 1
- 229910052751 metal Inorganic materials 0.000 description 18
- 239000002184 metal Substances 0.000 description 18
- 239000003973 paint Substances 0.000 description 13
- IIZPXYDJLKNOIY-JXPKJXOSSA-N 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphocholine Chemical compound CCCCCCCCCCCCCCCC(=O)OC[C@H](COP([O-])(=O)OCC[N+](C)(C)C)OC(=O)CCC\C=C/C\C=C/C\C=C/C\C=C/CCCCC IIZPXYDJLKNOIY-JXPKJXOSSA-N 0.000 description 11
- 235000010445 lecithin Nutrition 0.000 description 11
- 239000000787 lecithin Substances 0.000 description 11
- 229940067606 lecithin Drugs 0.000 description 11
- 239000007789 gas Substances 0.000 description 9
- 238000006243 chemical reaction Methods 0.000 description 8
- 238000010301 surface-oxidation reaction Methods 0.000 description 8
- 229910045601 alloy Inorganic materials 0.000 description 7
- 239000000956 alloy Substances 0.000 description 7
- 230000000052 comparative effect Effects 0.000 description 7
- ZWEHNKRNPOVVGH-UHFFFAOYSA-N 2-Butanone Chemical compound CCC(C)=O ZWEHNKRNPOVVGH-UHFFFAOYSA-N 0.000 description 6
- 230000006866 deterioration Effects 0.000 description 6
- 230000004907 flux Effects 0.000 description 6
- 229910020630 Co Ni Inorganic materials 0.000 description 5
- 229910002440 Co–Ni Inorganic materials 0.000 description 5
- 238000005259 measurement Methods 0.000 description 5
- 239000000203 mixture Substances 0.000 description 5
- 229920003171 Poly (ethylene oxide) Polymers 0.000 description 4
- 239000002904 solvent Substances 0.000 description 4
- 230000005294 ferromagnetic effect Effects 0.000 description 3
- 150000004767 nitrides Chemical class 0.000 description 3
- LKMJVFRMDSNFRT-UHFFFAOYSA-N 2-(methoxymethyl)oxirane Chemical compound COCC1CO1 LKMJVFRMDSNFRT-UHFFFAOYSA-N 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 229910017061 Fe Co Inorganic materials 0.000 description 2
- 239000004166 Lanolin Substances 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- JHIVVAPYMSGYDF-UHFFFAOYSA-N cyclohexanone Chemical compound O=C1CCCCC1 JHIVVAPYMSGYDF-UHFFFAOYSA-N 0.000 description 2
- 235000014113 dietary fatty acids Nutrition 0.000 description 2
- 229910001873 dinitrogen Inorganic materials 0.000 description 2
- 150000002148 esters Chemical class 0.000 description 2
- 238000001704 evaporation Methods 0.000 description 2
- 230000008020 evaporation Effects 0.000 description 2
- 239000000194 fatty acid Substances 0.000 description 2
- 229930195729 fatty acid Natural products 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 229940039717 lanolin Drugs 0.000 description 2
- 235000019388 lanolin Nutrition 0.000 description 2
- 229940094506 lauryl betaine Drugs 0.000 description 2
- 230000005415 magnetization Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- DVEKCXOJTLDBFE-UHFFFAOYSA-N n-dodecyl-n,n-dimethylglycinate Chemical compound CCCCCCCCCCCC[N+](C)(C)CC([O-])=O DVEKCXOJTLDBFE-UHFFFAOYSA-N 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000003760 tallow Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- FFJCNSLCJOQHKM-CLFAGFIQSA-N (z)-1-[(z)-octadec-9-enoxy]octadec-9-ene Chemical compound CCCCCCCC\C=C/CCCCCCCCOCCCCCCCC\C=C/CCCCCCCC FFJCNSLCJOQHKM-CLFAGFIQSA-N 0.000 description 1
- ZORQXIQZAOLNGE-UHFFFAOYSA-N 1,1-difluorocyclohexane Chemical compound FC1(F)CCCCC1 ZORQXIQZAOLNGE-UHFFFAOYSA-N 0.000 description 1
- WCVOGSZTONGSQY-UHFFFAOYSA-N 2,4,6-trichloroanisole Chemical compound COC1=C(Cl)C=C(Cl)C=C1Cl WCVOGSZTONGSQY-UHFFFAOYSA-N 0.000 description 1
- HVYJSOSGTDINLW-UHFFFAOYSA-N 2-[dimethyl(octadecyl)azaniumyl]acetate Chemical compound CCCCCCCCCCCCCCCCCC[N+](C)(C)CC([O-])=O HVYJSOSGTDINLW-UHFFFAOYSA-N 0.000 description 1
- RNMDNPCBIKJCQP-UHFFFAOYSA-N 5-nonyl-7-oxabicyclo[4.1.0]hepta-1,3,5-trien-2-ol Chemical compound C(CCCCCCCC)C1=C2C(=C(C=C1)O)O2 RNMDNPCBIKJCQP-UHFFFAOYSA-N 0.000 description 1
- DKPFZGUDAPQIHT-UHFFFAOYSA-N Butyl acetate Natural products CCCCOC(C)=O DKPFZGUDAPQIHT-UHFFFAOYSA-N 0.000 description 1
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- 229910001030 Iron–nickel alloy Inorganic materials 0.000 description 1
- NTIZESTWPVYFNL-UHFFFAOYSA-N Methyl isobutyl ketone Chemical compound CC(C)CC(C)=O NTIZESTWPVYFNL-UHFFFAOYSA-N 0.000 description 1
- UIHCLUNTQKBZGK-UHFFFAOYSA-N Methyl isobutyl ketone Natural products CCC(C)C(C)=O UIHCLUNTQKBZGK-UHFFFAOYSA-N 0.000 description 1
- 229910000990 Ni alloy Inorganic materials 0.000 description 1
- 229910003271 Ni-Fe Inorganic materials 0.000 description 1
- 208000000474 Poliomyelitis Diseases 0.000 description 1
- 239000002202 Polyethylene glycol Substances 0.000 description 1
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical class [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 1
- BCKXLBQYZLBQEK-KVVVOXFISA-M Sodium oleate Chemical compound [Na+].CCCCCCCC\C=C/CCCCCCCC([O-])=O BCKXLBQYZLBQEK-KVVVOXFISA-M 0.000 description 1
- BZHJMEDXRYGGRV-UHFFFAOYSA-N Vinyl chloride Chemical compound ClC=C BZHJMEDXRYGGRV-UHFFFAOYSA-N 0.000 description 1
- 229920002433 Vinyl chloride-vinyl acetate copolymer Polymers 0.000 description 1
- PZQBWGFCGIRLBB-NJYHNNHUSA-N [(2r)-2-[(2s,3r,4s)-3,4-dihydroxyoxolan-2-yl]-2-octadecanoyloxyethyl] octadecanoate Chemical compound CCCCCCCCCCCCCCCCCC(=O)OC[C@@H](OC(=O)CCCCCCCCCCCCCCCCC)[C@H]1OC[C@H](O)[C@H]1O PZQBWGFCGIRLBB-NJYHNNHUSA-N 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 150000003973 alkyl amines Chemical class 0.000 description 1
- 239000002280 amphoteric surfactant Substances 0.000 description 1
- 125000000129 anionic group Chemical group 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 239000003093 cationic surfactant Substances 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 150000004985 diamines Chemical class 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
- 229940043264 dodecyl sulfate Drugs 0.000 description 1
- DDXLVDQZPFLQMZ-UHFFFAOYSA-M dodecyl(trimethyl)azanium;chloride Chemical compound [Cl-].CCCCCCCCCCCC[N+](C)(C)C DDXLVDQZPFLQMZ-UHFFFAOYSA-M 0.000 description 1
- HBRNMIYLJIXXEE-UHFFFAOYSA-N dodecylazanium;acetate Chemical compound CC(O)=O.CCCCCCCCCCCCN HBRNMIYLJIXXEE-UHFFFAOYSA-N 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- LRMHFDNWKCSEQU-UHFFFAOYSA-N ethoxyethane;phenol Chemical compound CCOCC.OC1=CC=CC=C1 LRMHFDNWKCSEQU-UHFFFAOYSA-N 0.000 description 1
- 150000004665 fatty acids Chemical class 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- NVVZQXQBYZPMLJ-UHFFFAOYSA-N formaldehyde;naphthalene-1-sulfonic acid Chemical compound O=C.C1=CC=C2C(S(=O)(=O)O)=CC=CC2=C1 NVVZQXQBYZPMLJ-UHFFFAOYSA-N 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- FUZZWVXGSFPDMH-UHFFFAOYSA-N hexanoic acid Chemical compound CCCCCC(O)=O FUZZWVXGSFPDMH-UHFFFAOYSA-N 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 239000012948 isocyanate Substances 0.000 description 1
- 150000002576 ketones Chemical class 0.000 description 1
- 239000000696 magnetic material Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 239000012046 mixed solvent Substances 0.000 description 1
- PSZYNBSKGUBXEH-UHFFFAOYSA-N naphthalene-1-sulfonic acid Chemical compound C1=CC=C2C(S(=O)(=O)O)=CC=CC2=C1 PSZYNBSKGUBXEH-UHFFFAOYSA-N 0.000 description 1
- 239000002736 nonionic surfactant Substances 0.000 description 1
- UPHWVVKYDQHTCF-UHFFFAOYSA-N octadecylazanium;acetate Chemical compound CC(O)=O.CCCCCCCCCCCCCCCCCCN UPHWVVKYDQHTCF-UHFFFAOYSA-N 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920001223 polyethylene glycol Polymers 0.000 description 1
- 229920000139 polyethylene terephthalate Polymers 0.000 description 1
- 239000005020 polyethylene terephthalate Substances 0.000 description 1
- 229920000259 polyoxyethylene lauryl ether Polymers 0.000 description 1
- 239000000244 polyoxyethylene sorbitan monooleate Substances 0.000 description 1
- 235000010482 polyoxyethylene sorbitan monooleate Nutrition 0.000 description 1
- 229920000053 polysorbate 80 Polymers 0.000 description 1
- 229920005749 polyurethane resin Polymers 0.000 description 1
- 229940096992 potassium oleate Drugs 0.000 description 1
- MLICVSDCCDDWMD-KVVVOXFISA-M potassium;(z)-octadec-9-enoate Chemical compound [K+].CCCCCCCC\C=C/CCCCCCCC([O-])=O MLICVSDCCDDWMD-KVVVOXFISA-M 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000004062 sedimentation Methods 0.000 description 1
- 239000001593 sorbitan monooleate Substances 0.000 description 1
- 235000011069 sorbitan monooleate Nutrition 0.000 description 1
- 229940035049 sorbitan monooleate Drugs 0.000 description 1
- 239000003381 stabilizer Substances 0.000 description 1
- 239000004094 surface-active agent Substances 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
本発明は、磁気記録媒体用磁性粉末の製造方法に係り、
特に金属磁性粉末等酸化性磁性粉末を磁気記録媒体に使
用したときの耐酸化性及び分散性を改善した磁性粉末の
製造方法に関する。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for producing magnetic powder for magnetic recording media.
In particular, the present invention relates to a method for producing magnetic powder with improved oxidation resistance and dispersibility when oxidizing magnetic powder such as metal magnetic powder is used in a magnetic recording medium.
従来の技術
磁性粉末は、ビディオテーブ、オーディオテープ、コン
ピュータ用情報記録テープ、フロッピーディスク等の磁
気記録媒体に広く使用されている。この磁性粉末には、
金属粉末、金属窒化物粉末、金属酸化物粉末があり、前
二者は後者より飽和磁束密度、保持力が大きく、これら
磁気特性の点で優れている。しかし、これらの金属粉末
、金属窒化物粉末は、酸化され易く、例えば磁気テープ
として使用されているときに空気に触れて酸化され、そ
の磁気特性を低下させる欠点がある。BACKGROUND OF THE INVENTION Magnetic powders are widely used in magnetic recording media such as videotapes, audio tapes, computer information recording tapes, floppy disks, etc. This magnetic powder has
There are metal powders, metal nitride powders, and metal oxide powders, and the former two have higher saturation magnetic flux density and coercive force than the latter, and are superior in these magnetic properties. However, these metal powders and metal nitride powders are easily oxidized, and have the drawback that, for example, when they are used as a magnetic tape, they are oxidized when exposed to air, reducing their magnetic properties.
このため、金属粉末、金属窒化物粉末の耐酸化性を高め
るために、予めこれらの粉末表面に比較的安定な酸化膜
を形成させる酸化処理を行ない、空気中で使用しても急
激な酸化が起こらないような工夫がいくつか提案されて
いる。Therefore, in order to improve the oxidation resistance of metal powders and metal nitride powders, oxidation treatment is performed in advance to form a relatively stable oxide film on the surface of these powders, so that even when used in air, rapid oxidation will not occur. Several measures have been proposed to prevent this from happening.
例えば、トルエン等の有機溶媒中にそのＩ［ｉ［ｉｌの
１７２〜１７５程度の磁性粉末を浸漬して毎分１〜１０
０回の回転速度で撹拌し、この状態で乾燥空気等の酸化
性ガスを吹き込みながら８０〜１００℃に加温して溶剤
を蒸発させ、これを溶剤が蒸発し尽くすまで行なう方法
が知られている。For example, a magnetic powder of about 172 to 175 of I[i[il] is immersed in an organic solvent such as toluene, and the magnetic powder is
A known method is to evaporate the solvent by stirring at a rotational speed of 0 and then heating it to 80 to 100°C while blowing an oxidizing gas such as dry air into it until the solvent is completely evaporated. There is.
発明が解決しようとする問題点
しかしながら、このような方法で表面酸化処理をした例
えば金属粉末を磁性塗料にし、これを基材に塗布して例
えば磁気テープを作成し、その残留磁束密度（Ｂｒ）、
飽和磁束密度（ＢＳ）を測定し、角形比（Ｂｒ／Ｂｓ）
を求めると、０．６８であり、表面酸化処理しない金属
磁性粉末の同じ条件下における角形比０．７９より小さ
くなる。Problems to be Solved by the Invention However, if a magnetic paint is made from, for example, a metal powder whose surface has been subjected to surface oxidation treatment using such a method, and this is applied to a base material to create, for example, a magnetic tape, the residual magnetic flux density (Br) ,
Measure the saturation magnetic flux density (BS) and calculate the squareness ratio (Br/Bs)
is found to be 0.68, which is smaller than the squareness ratio of 0.79 under the same conditions for metal magnetic powder without surface oxidation treatment.
これは、磁気テープを製造するときに磁性塗料を塗布し
、その未乾燥状態で磁場をかけ配向させる工程で、磁性
粉末の分散性及び配向性が、表面処理した金属磁性粉末
の場合には劣ることを示すものである。This is a process in which magnetic paint is applied when manufacturing magnetic tape, and then a magnetic field is applied to orient the paint in its wet state.The dispersibility and orientation of the magnetic powder are inferior to that of surface-treated metal magnetic powder. This shows that.
このように、金属磁性粉末の耐酸化性を高めると分散性
が低下するという問題点があった。As described above, there is a problem in that increasing the oxidation resistance of the metal magnetic powder reduces the dispersibility.
本発明の目的は、耐酸化性を高めるとともに分散性を向
上させることができる磁気記録媒体用磁性粉末の製造方
法を提供することにある。An object of the present invention is to provide a method for producing magnetic powder for magnetic recording media, which can improve oxidation resistance and dispersibility.
問題点を解決するための手段
本発明は、上記問題点を解決するために、分散剤の存在
下に酸化性磁性粉末を有機溶剤中に浸漬した状態で撹拌
する工程と、この後の工程の少なくとも分散剤を存在さ
せた状態の酸化性磁性粉末と酸化性ガスとを接触させる
工程を有することを特徴とする磁気記録媒体用磁性粉末
の製造方法を提供するものである。Means for Solving the Problems In order to solve the above problems, the present invention includes a step of stirring an oxidizing magnetic powder immersed in an organic solvent in the presence of a dispersant, and a subsequent step. The present invention provides a method for producing magnetic powder for a magnetic recording medium, which comprises a step of bringing oxidizing magnetic powder in the presence of at least a dispersant into contact with an oxidizing gas.
次に本発明の詳細な説明する。Next, the present invention will be explained in detail.
本発明において、酸化性磁性粉末とは、金属磁性粉末、
窒化鉄粉末が挙げられ、これらはその形状、組成に限定
されるものではない。In the present invention, oxidizing magnetic powder refers to metal magnetic powder,
Examples include iron nitride powder, but these are not limited in shape or composition.
金属磁性粉末としては強磁性合金粉末が挙げられ、これ
には金属分が７５重重景以上で、金属分の８０笛量％以
上が少なくともＦｅ、、Ｃｏｓ Ｎｉ、Ｆｅ−Ｃｏ 、
Ｆｅ−Ｎｉ 、 Ｃｏ−Ｎｉ又はＣｏ−Ｎｉ−Ｆｅの一
種の強磁性金属、金属分の２０重量％以下、好ましくは
０．５−５重量％がＡｊ！、Ｓｉｘ Ｓ ５Ｓｃｓ Ｔ
ｉｓ Ｖ 。Examples of the metal magnetic powder include ferromagnetic alloy powder, which has a metal content of 75% or more, and 80% or more of the metal content is at least Fe, Cos Ni, Fe-Co,
Aj! is a kind of ferromagnetic metal such as Fe-Ni, Co-Ni or Co-Ni-Fe, and the metal content is 20% by weight or less, preferably 0.5-5% by weight. , Six S 5Scs T
isV.
ＣｒＳＭｎ、 Ｃｕ、 Ｚｎ、 Ｙ ｓ ＨａＳＲｈＳ
ＰｄＳＡｇ、 Ｓｎｚ Ｓｂ−、。CrSMn, Cu, Zn, Ys HaSRhS
PdSAg, Snz Sb-,.
Ｔｅ５Ｂａｓ Ｔａｓ Ｗ 、Ｒｅ５Ａｕ％Ｈｙ、、Ｐ
ｂｓ Ｂｉｓ Ｌａ、、 Ｃｅ。Te5Bas Tas W, Re5Au%Hy,,P
bs Bis La,, Ce.
Ｐｒｓ Ｎｄ５Ｂ ｓ Ｐなどの組成を有するものであ
り、少量の水、水酸化物又は酸化物を含有する場合があ
る。これらの強磁性合金粉末は長径が０．５μ−以下の
粒子である。It has a composition such as Prs Nd5B s P, and may contain a small amount of water, hydroxide, or oxide. These ferromagnetic alloy powders are particles with a major axis of 0.5 μm or less.
分散剤としては、陰イオン活性剤、例えば、オレイン酸
ソーダ石ケン、オレイン酸カリ石ケン、ラウリル硫酸エ
ステルソーダ塩、ドデシルベンゼンスルフオン酸ソーダ
塩、アルキルナフタレンスルフオン酸ソーダ塩、ナフタ
レンスルフオン酸ソーダ塩、ナフタレンスルフオン酸ホ
ルマリン縮合物、ポリオキシエチレンアルキルサルフェ
ートソーダ塩、ラノリン脂肪酸塩等が挙げられる。また
、非イオン性界面活性剤、例えばポリオキシエチレンラ
ウリルエーテル、ポリオキシエチレンセチルエーテル、
ポリオキシエチレンステアリルエーテル、ポリオキシエ
チレンオレイルエーテル、ポリオキシエチレンオシ
クチルフェノールエーテル、ポリオ判圧チレンノニルフ
ェノールエーテル、ソルビタンジステアレート、ソルビ
タンモノオレエート、ツルとタンセスキオレエート、ポ
リオキシエチレンソルビタンモノラウレート、ポリエチ
レングリコールモノラウレート、メチルグリシジルエー
テル等が挙げられる。また、陽イオン性界面活性剤、例
えばラウリルアミンアセテート、ラウリルトリメチルア
ンモニウムクロライド、ポリオキシエチレンアルキルア
ミン、ディオミンーＮアルキルトリアミン、牛脂アルキ
ルプロピレンジアミン、オクタデシルアミンアセテート
等が挙げられる。また、両性界面活性剤、例えばラウリ
ルベタイン、ステアリルベタイン等が挙げられる。また
、レシチンも使用できる。As a dispersant, anionic active agents such as sodium oleate soap, potassium oleate soap, lauryl sulfate ester sodium salt, dodecylbenzenesulfonate sodium salt, alkylnaphthalene sulfonate sodium salt, naphthalene sulfonic acid Examples include soda salt, naphthalene sulfonic acid formalin condensate, polyoxyethylene alkyl sulfate soda salt, and lanolin fatty acid salt. Also, nonionic surfactants such as polyoxyethylene lauryl ether, polyoxyethylene cetyl ether,
Polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene ocyctyl phenol ether, polio tyrene nonyl phenol ether, sorbitan distearate, sorbitan monooleate, vine and tansesquioleate, polyoxyethylene sorbitan monooleate ester, polyethylene glycol monolaurate, methyl glycidyl ether, and the like. Further, cationic surfactants such as laurylamine acetate, lauryltrimethylammonium chloride, polyoxyethylene alkylamine, diomine-N alkyltriamine, tallow alkylpropylene diamine, octadecylamine acetate, and the like can be mentioned. Also included are amphoteric surfactants such as lauryl betaine and stearyl betaine. Lecithin can also be used.
なお、上記の界面活性剤は併用することもできる。Note that the above surfactants can also be used in combination.
本発明に用いられる有機溶剤は、トルエン、キシレン等
の芳香族炭化水素、ヘキサン、ヘプタン、オクタン等の
脂肪族炭化水素、メチルイソブチルケトン、メチルエチ
ルケトン、シクロヘキサノン等のケトン類、酢酸ブチル
等のエステル類の単独又は混合溶剤が挙げられ、水分含
有量が少ない点からは芳香族炭化水素、脂肪族炭化水素
が好ましい。Organic solvents used in the present invention include aromatic hydrocarbons such as toluene and xylene, aliphatic hydrocarbons such as hexane, heptane, and octane, ketones such as methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone, and esters such as butyl acetate. Single or mixed solvents may be used, and aromatic hydrocarbons and aliphatic hydrocarbons are preferred from the viewpoint of low water content.
本発明においては酸化性磁性粉末を上記有機溶剤中で上
記分散剤の存在下に浸漬するが、この浸漬の方法は、分
散剤を熔解又は分散により含有させた有機溶剤液に酸化
性磁性粉末を加えることもでき、逆にこの有機溶媒液を
酸化性磁性粉末に加えることもでき、さらに酸化性磁性
粉末と有機溶剤との混合物に分散剤を溶解又は分散によ
り含有させても良く、酸化性磁性粉末と分散剤を有機溶
剤に加えても良い。In the present invention, the oxidizing magnetic powder is immersed in the organic solvent in the presence of the dispersing agent, but this immersion method involves adding the oxidizing magnetic powder to the organic solvent solution containing the dispersing agent by melting or dispersing it. Alternatively, this organic solvent solution can be added to the oxidizing magnetic powder, or a dispersing agent may be dissolved or dispersed in the mixture of the oxidizing magnetic powder and the organic solvent. The powder and dispersant may be added to the organic solvent.
これらの各成分の比率については、酸化性磁性粉末を溶
剤の重量の２０％〜２００％、分散剤を酸化性磁性粉末
に対して０．２〜５重量％含有させることが好ましい、
これらの範囲が酸化性磁性粉末に分散剤を効率良く被覆
することができる。Regarding the ratio of each of these components, it is preferable that the oxidizing magnetic powder be contained in an amount of 20% to 200% by weight of the solvent, and the dispersant be contained in an amount of 0.2 to 5% by weight based on the oxidized magnetic powder.
Within these ranges, the oxidizable magnetic powder can be efficiently coated with the dispersant.
このような酸化性磁性粉末、分散剤、有機溶剤は撹拌さ
れる。この撹拌には例えばヘンシェルミキサ、振動型撹
拌機等の回転ミキサが使用され、その回転速度は毎分１
〜１００ 、回転が例示されるが、これにかぎるもので
はない、この撹拌の際、６０℃〜１２０℃に加温するこ
とが分散剤を効率良く被覆する点で好ましい。なお、撹
拌には磁性粉末の凝集を解くような撹拌も含む。Such oxidizable magnetic powder, dispersant, and organic solvent are stirred. For example, a rotary mixer such as a Henschel mixer or a vibratory mixer is used for this stirring, and the rotation speed is 1/min.
-100 degrees centigrade rotation is exemplified, but is not limited thereto.During this stirring, it is preferable to heat the mixture to 60 to 120 degrees Celsius in order to efficiently coat the dispersant. Note that stirring also includes stirring to loosen the agglomeration of the magnetic powder.
このようにして酸化性磁性粉末は有機溶剤中の分散剤に
より処理されるが、この後酸化性ガスと接触される。こ
の接触の方法としては、有機溶剤を常圧下又は減圧下で
蒸発除去するか、あるいは沈降分離、濾別してから酸化
性ガスと接触させる。また、有機溶剤の存在下で酸化性
ガスを吹き込み、溶剤が蒸発した後も継続して酸化性ガ
スを吹き込むことができる。酸化性ガスとしては乾燥空
気、酸素が例示されるが、その酸素量を窒素ガス等の不
活性ガスを混合して調整しても良い、この酸化性ガスと
の接触も常温より６０℃〜１２０℃に加温して行うとさ
らに効果がある。In this way, the oxidizable magnetic powder is treated with a dispersant in an organic solvent, after which it is contacted with an oxidizing gas. As a method for this contact, the organic solvent is removed by evaporation under normal pressure or reduced pressure, or the organic solvent is separated by sedimentation and filtration, and then brought into contact with the oxidizing gas. Further, the oxidizing gas can be blown in in the presence of an organic solvent, and the oxidizing gas can be continuously blown in even after the solvent has evaporated. Examples of the oxidizing gas include dry air and oxygen, but the amount of oxygen may be adjusted by mixing an inert gas such as nitrogen gas. Contact with this oxidizing gas is also carried out at a temperature of 60°C to 120°C above room temperature. It is even more effective when heated to ℃.
実施例 次に本発明の詳細な説明する。Example Next, the present invention will be explained in detail.
実施例１
ヘンシェルミキサ（三井三池工機製）の反応器の中に、
トルエン５ ｋｇと、レシチン（分散剤）４５ｇとＦｅ
−Ｃｏ−Ｎｉ合金針状粉末（長軸０．２ ｕｒｎ、短軸
０．０３μｍ ） ４．５ ｋｇとを混入し、撹拌しな
がら減圧、加温し続けた。トルエンの蒸発回収が終了し
た時点の反応器内の温度は８０℃であった。Example 1 In the reactor of a Henschel mixer (manufactured by Mitsui Miike Koki),
5 kg of toluene, 45 g of lecithin (dispersant) and Fe
4.5 kg of -Co-Ni alloy needle-like powder (long axis: 0.2 urn, short axis: 0.03 μm) was mixed in, and the mixture was kept under reduced pressure and heated while stirring. The temperature inside the reactor was 80° C. when the evaporation and recovery of toluene was completed.
温度を８０℃に保ったまま、減圧を解除し、窒素ガスと
乾燥空気とをｌ：ｌの割合で混合した混合ガスを３０１
／分の流量でヘンシェルミキサの反応器内に流入させた
。これを反応温度を８０℃に保ったまま、４時間継続し
て、粉末の表面酸化処理を終了した。While keeping the temperature at 80°C, the reduced pressure was released and a mixed gas of nitrogen gas and dry air mixed at a ratio of 1:1 was added to 301 °C.
It was flowed into the reactor of a Henschel mixer at a flow rate of /min. This was continued for 4 hours while maintaining the reaction temperature at 80° C. to complete the surface oxidation treatment of the powder.
この表面酸化処理をした粉末を内径２．８ ｍ、高さ４
．３ ｖａのプラスチック筒状容器中に詰めて、粉末の
重量を測定し、次いで振動試料型磁力計（理研電子株式
会社製）によって、保磁力Ｈｃ（ｉｊｅ） 、飽和磁化
σｇ （ｅｍｕ ／ｇ ）を測定して表１に示した。This surface oxidized powder was sized with an inner diameter of 2.8 m and a height of 4 m.
．． The powder was packed in a 3 va plastic cylindrical container, the weight of the powder was measured, and the coercive force Hc (ije) and saturation magnetization σg (emu/g) were measured using a vibrating sample magnetometer (manufactured by Riken Denshi Co., Ltd.). The results are shown in Table 1.
次いで、上記表面酸化処理をした粉末の一部を６０℃−
９０％Ｉ？Ｉ（（相対湿度）の恒温恒湿槽中に７日間放
置した後同様の測定を行ってへの劣化率を求めて表１に
示した。Next, a part of the powder subjected to the above surface oxidation treatment was heated to 60°C.
90% I? After being left in a constant temperature and humidity chamber at (relative humidity) for 7 days, similar measurements were carried out to determine the deterioration rate, which is shown in Table 1.
次に、上記表面酸化処理した磁性粉末１０００ｇと、塩
化ビニール−酢酸ビニル共重合体１１０ｇと、ポリウレ
タン樹ＪＪ１１１０ｇと塩化ビニール安定剤２０ｇと、
イソシアネート化合物２０ｇと、トルエン１３００ｇと
、メチルエチルケトン１３００ｇとを混合分散して磁性
塗料を調製し、ポリエチレンテレフタレートフィルム上
に従来行ワしている公知の方法によって磁気テープを製
作し、前記振動試料型磁力計によって、保磁力Ｈａ （
′６ｅ）、飽和磁束密度Ｂｓ （Ｇａｕｓｓ ） 、残
留磁束密度Ｂｒ（Ｇａｕｓｓ ）とを求め角形比Ｂｒ１
０ｓを計算して表１に示した。Next, 1000 g of the above surface oxidized magnetic powder, 110 g of vinyl chloride-vinyl acetate copolymer, 1110 g of polyurethane resin JJ, and 20 g of vinyl chloride stabilizer,
A magnetic paint was prepared by mixing and dispersing 20 g of an isocyanate compound, 1300 g of toluene, and 1300 g of methyl ethyl ketone, and a magnetic tape was prepared by a known method conventionally applied on a polyethylene terephthalate film. The coercive force Ha (
'6e), the saturation magnetic flux density Bs (Gauss), and the residual magnetic flux density Br (Gauss) are determined, and the squareness ratio Br1 is calculated.
0s was calculated and shown in Table 1.
なお、上記磁気テープを６０℃−９０％ＲＨ恒温恒湿中
に７日間放置した後のＢｓを測定し、Ｂｓの劣化率を求
めて表１に示した。The Bs was measured after the magnetic tape was left in a constant temperature and humidity environment of 60° C. and 90% RH for 7 days, and the deterioration rate of Bs was determined and shown in Table 1.
実施例２
実施例１において、レシチンに代えてデイオミンーＮア
ルキルトリメチンレンジアミンを２２５ｇ用いたことと
、反応温度を６０℃にしたこと以外は実施例１と同様に
して表面酸化処理した磁性粉末を作成し、さらにこれを
用いて磁性塗料を調製して磁気テープを作成し、これら
について実施例１と同様に測定した結果を表１に示す。Example 2 Magnetic powder was subjected to surface oxidation treatment in the same manner as in Example 1 except that 225 g of diomine-N alkyltrimethine diamine was used instead of lecithin and the reaction temperature was set to 60°C. This was used to prepare a magnetic coating material to make a magnetic tape, and the results of measurements on these tapes in the same manner as in Example 1 are shown in Table 1.
実施例３
実施例１において、レシチンに代えてラノリン脂肪酸カ
ルシウム４．５ｇを用いたことと、反応温度を１２０℃
にしたこと以外は実施例１と同様にして表面酸化処理し
た磁性粉末を作成し、さらにこれを用いて磁性塗料を調
製して磁気テープを作成し、これらについて実施例１と
同様に、測定した結果を表１に示す。Example 3 In Example 1, 4.5 g of lanolin fatty acid calcium was used instead of lecithin, and the reaction temperature was changed to 120°C.
A magnetic powder whose surface was oxidized was prepared in the same manner as in Example 1, except that a magnetic paint was prepared using this powder to form a magnetic tape, and these were measured in the same manner as in Example 1. The results are shown in Table 1.
実施例４
実施例１において、Ｆｅ−Ｃｏ−Ｎｉ合金針状粉末に代
えて窒化鉄磁性粉末を用いたことと、レシチンに代えて
メチルグリシジルエーテル４５ｇ用いたことと、反応温
度を６０℃にしたこと以外は実施例１と同様にして表面
酸化処理した磁性粉末を作成し、さらにこれを用いて磁
性塗料を調製して磁気テープを作成し、これらについて
実施例１と同様に測定した結果を表２に示す。Example 4 In Example 1, iron nitride magnetic powder was used instead of Fe-Co-Ni alloy acicular powder, 45 g of methyl glycidyl ether was used instead of lecithin, and the reaction temperature was changed to 60°C. Except for the above, a surface oxidized magnetic powder was prepared in the same manner as in Example 1, and a magnetic paint was prepared using this powder to prepare a magnetic tape, and the results were measured in the same manner as in Example 1. Shown in 2.
実施例５
実施例１において、Ｆｅ−Ｃｏ’−Ｎｉ合金針状粉末に
代えて窒化鉄粉末を用いたことと、レシチンに代えて牛
脂アルキルプロピレンジアミン２２５ｇ用いたことと、
反応温度を６０℃としたこと以外は実施例１と同様にし
て表面酸化処理した磁性粉末を作成し、さらにこれを用
いて磁性塗料を−ｍ製して磁気テープを作成し、これら
について実施例１と同様に測定した結果を表２に示す。Example 5 In Example 1, iron nitride powder was used instead of the Fe-Co'-Ni alloy needle powder, and 225 g of tallow alkylpropylene diamine was used instead of lecithin.
A surface oxidized magnetic powder was prepared in the same manner as in Example 1, except that the reaction temperature was 60°C, and a magnetic paint was made using this powder to prepare a magnetic tape. Table 2 shows the results measured in the same manner as in 1.
実施例６
実施例１において、Ｆｅ−Ｃｏ−Ｎｉ合金針状粉末に代
えて窒化鉄粉末を用いたことと、レシチンに代えてラウ
リルベタイン４．５ｇ用いたことと、反応温度１２０℃
としたこと以外は実施例１と同様にして表面酸化処理し
た磁性粉末を作成し、さらにこれを用いて磁性塗料をｔ
ＩＩｉｉ製して磁気テープを作成し、これらについて実
施例１と同様に測定した結果を表２に示す。Example 6 In Example 1, iron nitride powder was used instead of Fe-Co-Ni alloy needle powder, 4.5 g of lauryl betaine was used instead of lecithin, and the reaction temperature was 120°C.
A magnetic powder whose surface was oxidized was prepared in the same manner as in Example 1 except that the powder was coated with magnetic paint.
Table 2 shows the results of measurements made in the same manner as in Example 1.
比較例１
実施例１において、レシチンを使用しなかったことと、
反応温度を２０℃としたこと以外は実施例１と同様にし
て表面酸化処理した磁性粉末を作成し、さらにこれを用
いて磁性塗料を調製して磁気テープを作成し、これらに
ついて実施例１と同様に測定した結果を表２に示す。Comparative Example 1 In Example 1, lecithin was not used, and
A surface oxidized magnetic powder was prepared in the same manner as in Example 1 except that the reaction temperature was 20°C, and a magnetic paint was prepared using this powder to form a magnetic tape. Table 2 shows the results of similar measurements.
比較例２
実施例１において、レシチンを使用しなかったこと以外
は実施例１と同様にして表面酸化処理した磁性粉末を作
成し、さらにこれを用いて磁性塗料を調製して磁気テー
プを作成し、これらについて実施例１と同様に測定した
結果を表２に示す。Comparative Example 2 A surface oxidized magnetic powder was prepared in the same manner as in Example 1 except that lecithin was not used, and a magnetic paint was prepared using this powder to make a magnetic tape. , these were measured in the same manner as in Example 1, and the results are shown in Table 2.
比較例３
実施例１において、Ｆｅ−Ｃｏ−Ｎｉ合金針状粉末に代
えて窒化鉄粉末を用いたことと、レシチンを使用しなか
ったことと、反応温度を２０℃としたこと以外は実施例
１と同様にして表面酸化処理した磁性粉末を作成し、さ
らにこれを用いて磁性塗料を調製して磁気テープを作成
し、これらについて実施例１と同様に測定した結果を表
２に示す。Comparative Example 3 Example 1 except that iron nitride powder was used instead of Fe-Co-Ni alloy needle powder, lecithin was not used, and the reaction temperature was 20°C. A magnetic powder subjected to surface oxidation treatment was prepared in the same manner as in Example 1, and a magnetic paint was further prepared using the powder to form a magnetic tape. Table 2 shows the results of measurements of these powders in the same manner as in Example 1.
比較例４
実施例１において、Ｆｅ−Ｃｏ−Ｎｊ合金針状粉末に代
えて窒化鉄粉末を用いたことと、レシチンを使用しなか
ったこと以外は実施例１と同様にして表面酸化処理した
磁性粉末を作成し、さらにこれを用いて磁性塗料を調製
して磁気テープを作成し、これらについて実施例１と同
様に測定した結果を表２に示す。Comparative Example 4 Magnetic material subjected to surface oxidation treatment in the same manner as in Example 1 except that iron nitride powder was used instead of Fe-Co-Nj alloy needle powder and lecithin was not used. A powder was prepared, and a magnetic paint was prepared using the powder to prepare a magnetic tape. Table 2 shows the results of measuring the powder in the same manner as in Example 1.
これらのことから、実施例のものは、粉末特性、磁気テ
ープ特性のいずれにおいても飽和磁化へ、飽和磁束密度
ＢＳの劣化率が低く、磁気テープ特性の角形比も高いの
に比べ、比較例１と３は磁気テープ特性の角形比は高い
が、粉末特性、磁気テープ特性のへ及びＢｓの劣化率が
高く、比較例２と４はこれらのへ及びＢｓの劣化率は低
いが、角形比が低いことがわかる。From these facts, the example has low deterioration rate of saturation magnetization and saturation magnetic flux density BS in both powder properties and magnetic tape properties, and high squareness ratio of magnetic tape properties, compared to Comparative Example 1. Comparative Examples 2 and 3 have a high squareness ratio of magnetic tape characteristics, but a high deterioration rate of powder characteristics, magnetic tape characteristics, and Bs. Comparative Examples 2 and 4 have a low deterioration rate of these and Bs, but a high squareness ratio. You can see that it is low.
このように実施例のものはへ及びＢｓの劣化率が低いこ
とから耐酸化性があり、角形比が高いことから分散性が
良いことがわかる。As described above, it can be seen that the samples of Examples have oxidation resistance due to the low deterioration rate of Bs and Bs, and have good dispersibility due to the high squareness ratio.
発明の効果
本発明によれば、酸化性磁性粉末を分散剤の存在下に表
面酸化処理を行ったので、金属磁性粉末、窒化鉄粉末に
ついて耐酸化性が得られるとともに、磁性塗料を塗布し
て得られる例えば磁気テープのような磁気記録媒体にお
ける分散性を向上することができる。これにより磁気記
録媒体の磁気特性を良好にするとともに、空気中繰り返
し長く使用しても磁気特性が劣化するようなことがない
ようにでき、酸化物磁性粉末より飽和磁化の大きい磁性
粉末の特性をよく利用することができる。Effects of the Invention According to the present invention, since the oxidizing magnetic powder is subjected to surface oxidation treatment in the presence of a dispersant, it is possible to obtain oxidation resistance for the metal magnetic powder and iron nitride powder, and to apply a magnetic paint. The dispersibility in the resulting magnetic recording medium, such as a magnetic tape, can be improved. This not only improves the magnetic properties of the magnetic recording medium but also prevents the magnetic properties from deteriorating even after repeated use in the air for long periods of time. It can be used often.
昭和６２年Ｏ１月０８日January 8, 1986
Claims (1)
浸漬した状態で撹拌する工程と、この工程の後の少なく
とも分散剤を存在させた状態の酸化性磁性粉末と酸化性
ガスとを接触させる工程を有することを特徴とする磁気
記録媒体用磁性粉末の製造方法。(1) A step of stirring the oxidizing magnetic powder immersed in an organic solvent in the presence of a dispersant, and after this step, stirring the oxidizing magnetic powder in the presence of at least the dispersing agent and the oxidizing gas. 1. A method for producing a magnetic powder for a magnetic recording medium, the method comprising the step of bringing into contact with a magnetic powder.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62001098A JPS63169707A (en) | 1987-01-08 | 1987-01-08 | Manufacture of magnetic powder for magnetic recording medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62001098A JPS63169707A (en) | 1987-01-08 | 1987-01-08 | Manufacture of magnetic powder for magnetic recording medium |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS63169707A true JPS63169707A (en) | 1988-07-13 |
Family
ID=11492011
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62001098A Pending JPS63169707A (en) | 1987-01-08 | 1987-01-08 | Manufacture of magnetic powder for magnetic recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63169707A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2620640A1 (en) * | 1988-09-16 | 1989-03-24 | Achim Hartmann | Fluid aluminium powder and process for its preparation |
| JPH03291304A (en) * | 1990-04-09 | 1991-12-20 | Tokin Corp | Shape anisotropic and soft magnetic alloy powder and manufacture thereof |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5378096A (en) * | 1976-12-20 | 1978-07-11 | Hitachi Maxell | Magnetic metal powder for magnetic recording and method of manufacturing same |
| JPS60242467A (en) * | 1984-05-17 | 1985-12-02 | Konishiroku Photo Ind Co Ltd | Treatment of magnetic powder |
-
1987
- 1987-01-08 JP JP62001098A patent/JPS63169707A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5378096A (en) * | 1976-12-20 | 1978-07-11 | Hitachi Maxell | Magnetic metal powder for magnetic recording and method of manufacturing same |
| JPS60242467A (en) * | 1984-05-17 | 1985-12-02 | Konishiroku Photo Ind Co Ltd | Treatment of magnetic powder |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2620640A1 (en) * | 1988-09-16 | 1989-03-24 | Achim Hartmann | Fluid aluminium powder and process for its preparation |
| JPH03291304A (en) * | 1990-04-09 | 1991-12-20 | Tokin Corp | Shape anisotropic and soft magnetic alloy powder and manufacture thereof |
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