JPH09139304A - Mnnibi alloy magnetic powder - Google Patents
Mnnibi alloy magnetic powderInfo
- Publication number
- JPH09139304A JPH09139304A JP7319475A JP31947595A JPH09139304A JP H09139304 A JPH09139304 A JP H09139304A JP 7319475 A JP7319475 A JP 7319475A JP 31947595 A JP31947595 A JP 31947595A JP H09139304 A JPH09139304 A JP H09139304A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic powder
- mnnibi
- alloy magnetic
- alloy
- mnbi
- 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
- 239000006247 magnetic powder Substances 0.000 title claims abstract description 50
- 229910045601 alloy Inorganic materials 0.000 title claims abstract description 46
- 239000000956 alloy Substances 0.000 title claims abstract description 46
- 229910016629 MnBi Inorganic materials 0.000 claims abstract description 18
- 239000002245 particle Substances 0.000 claims abstract description 13
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 7
- 239000012298 atmosphere Substances 0.000 abstract description 12
- 230000007797 corrosion Effects 0.000 abstract description 10
- 238000005260 corrosion Methods 0.000 abstract description 10
- 239000013078 crystal Substances 0.000 abstract description 8
- 238000004090 dissolution Methods 0.000 abstract description 3
- 239000002253 acid Substances 0.000 abstract description 2
- 238000012423 maintenance Methods 0.000 abstract 1
- 230000005415 magnetization Effects 0.000 description 10
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 9
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 9
- 239000000843 powder Substances 0.000 description 9
- 230000000052 comparative effect Effects 0.000 description 7
- 238000010438 heat treatment Methods 0.000 description 6
- 238000010298 pulverizing process Methods 0.000 description 6
- 229910016897 MnNi Inorganic materials 0.000 description 5
- 230000002378 acidificating effect Effects 0.000 description 5
- 230000007423 decrease Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 5
- 239000004570 mortar (masonry) Substances 0.000 description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- 239000011261 inert gas Substances 0.000 description 4
- 239000010410 layer Substances 0.000 description 4
- 239000002994 raw material Substances 0.000 description 4
- 238000002441 X-ray diffraction Methods 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 238000000354 decomposition reaction Methods 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 238000002844 melting Methods 0.000 description 3
- 230000008018 melting Effects 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 229910052757 nitrogen Inorganic materials 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- 238000004663 powder metallurgy Methods 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- 229910005578 NiBi Inorganic materials 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 229910052797 bismuth Inorganic materials 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 238000005245 sintering Methods 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 238000006467 substitution reaction Methods 0.000 description 2
- RZVAJINKPMORJF-UHFFFAOYSA-N Acetaminophen Chemical compound CC(=O)NC1=CC=C(O)C=C1 RZVAJINKPMORJF-UHFFFAOYSA-N 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 238000005238 degreasing Methods 0.000 description 1
- 230000005347 demagnetization Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000007578 melt-quenching technique Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000012299 nitrogen atmosphere Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 239000011241 protective layer Substances 0.000 description 1
- 239000005297 pyrex Substances 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000004381 surface treatment Methods 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 229910002058 ternary alloy Inorganic materials 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】この発明は室温で容易に消去
されることのない情報記録用携帯カ−ド等に用いられる
ＭｎＮｉＢｉ合金磁性粉末に関し、さらに詳しくは、特
に、酸性雰囲気の腐食環境下において、安定で分解しに
くい前記のＭｎＮｉＢｉ合金磁性粉末に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic powder of MnNiBi alloy which is not easily erased at room temperature and is used for portable information recording cards, and more particularly, particularly in a corrosive environment in an acidic atmosphere. The present invention relates to the above MnNiBi alloy magnetic powder, which is stable and hardly decomposed.
【０００２】[0002]
【従来の技術】ＭｎＢｉ合金磁性粉末を記録素子として
使用する磁気記録媒体は、一旦記録すると室温では容易
に書き換えができないという特徴を有し、特に、デ−タ
が誤って消去されたり、故意に書き換えらるなどの事故
や犯罪が多発しているクレジットカ−ド、プリペイドカ
−ドなどにおいて、事故や不正使用を防止できるものと
して注目されている。（特公昭５２−４６８０１号、特
公昭５４−１９２４４号、特公昭５４−３３７２５号、
特公昭５７−３８９６２号、特公昭５７−３８９６３
号、特公昭５９−３１７６４号）2. Description of the Related Art A magnetic recording medium using magnetic powder of MnBi alloy as a recording element has a characteristic that once it is recorded, it cannot be easily rewritten at room temperature, and in particular, data is erroneously erased or intentionally written. In credit cards, prepaid cards, and the like, where accidents and crimes such as rewriting occur frequently, they are attracting attention as being able to prevent accidents and unauthorized use. (Japanese Patent Publication No. 52-46801, Japanese Patent Publication No. 54-19244, Japanese Patent Publication No. 54-33725,
Japanese Patent Publication No. 57-38962, Japanese Patent Publication No. 57-38963
No. 59/31764)
【０００３】[0003]
【発明が解決しようとする課題】ところが、この種の磁
気記録媒体の記録素子として使用されるＭｎＢｉ合金磁
性粉末は、腐食環境下において分解しやすいという欠点
を有し、磁気テ−プに使用される場合は、リ−ルに巻か
れた状態で、使用、保管されるため、磁性層が腐食ガス
等にさらされることが少なくあまり問題とならないが、
情報記録用携帯カ−ドに使用される場合は、磁性層が露
出し、人体に直接触れる頻度が高いため、人体から発す
る塩分、水分、炭酸ガス、アンモニア等により腐食され
やすく、腐食環境下における分解を未然に防止すること
が問題となる。However, the MnBi alloy magnetic powder used as a recording element of this type of magnetic recording medium has a drawback that it is easily decomposed in a corrosive environment and is used for a magnetic tape. When used, the magnetic layer is not exposed to corrosive gas or the like because it is used and stored in a state of being wound on a reel, but it is not a serious problem.
When used in a portable information recording card, the magnetic layer is exposed and frequently comes into direct contact with the human body. Preventing decomposition is a problem.
【０００４】そこで、このようなＭｎＢｉ合金磁性粉末
の腐食を防止するため、ＭｎＢｉ合金磁性粉末の腐食の
原因となる特定の化学成分をＭｎＢｉ合金磁性粉末とと
もに使用する結合剤樹脂から除外したり、また腐食を助
長する水分や炭酸ガスなどが磁性層中に侵入するのを防
止したり、ＭｎＢｉ合金磁性粉末の粒子表面に保護層を
設けたりすることが行われているが、これらの方法で
は、未だ、充分に腐食環境下における分解を未然に防止
することができない。Therefore, in order to prevent such corrosion of the MnBi alloy magnetic powder, specific chemical components that cause the corrosion of the MnBi alloy magnetic powder are excluded from the binder resin used together with the MnBi alloy magnetic powder, or It has been attempted to prevent moisture or carbon dioxide gas that promotes corrosion from entering the magnetic layer, or to provide a protective layer on the particle surface of the MnBi alloy magnetic powder, but these methods have not yet been used. However, it is not possible to sufficiently prevent decomposition in a corrosive environment.
【０００５】この発明は、かかる現状に鑑み種々検討を
行った結果なされたもので、ＭｎＢｉ合金磁性粉末に第
３の元素としてＮｉを添加することにより、この種の合
金磁性粉末の腐食を充分に防止し、特に、酸性雰囲気の
腐食環境下において、安定で分解しにくいＭｎＮｉＢｉ
合金磁性粉末を提供しようとするものである。The present invention has been made as a result of various investigations in view of the present situation. By adding Ni as the third element to the MnBi alloy magnetic powder, the corrosion of this type of alloy magnetic powder is sufficiently performed. MnNiBi which is stable and hard to decompose, especially in a corrosive environment of acidic atmosphere
It is intended to provide an alloy magnetic powder.
【０００６】[0006]
【課題を解決するための手段】この発明のＭｎＮｉＢｉ
合金磁性粉末は、六方晶ＭｎＢｉ合金磁性粉末のＭｎの
位置にＮｉをＭｎとＮｉとの合計量に対して２〜１０原
子％置換して存在するようにしている。Means for Solving the Problems MnNiBi of the present invention
The alloy magnetic powder is made to exist at the Mn position of the hexagonal MnBi alloy magnetic powder by substituting Ni by 2 to 10 atom% with respect to the total amount of Mn and Ni.
【０００７】また、ＭｎＮｉＢｉ合金磁性粉末の平均粒
子径を0.５〜５μｍとし、２０℃における保磁力を４０
００〜１８０００エルステッドとなるようにしている。The MnNiBi alloy magnetic powder has an average particle size of 0.5 to 5 μm and a coercive force of 40 at 20 ° C.
It is set to be 00 to 18000 Oersted.
【０００８】[0008]
【発明の実施の形態】この発明のＭｎＮｉＢｉ合金磁性
粉末は、六方晶ＭｎＢｉ合金磁性粉末のＭｎの位置にＮ
ｉをＭｎとＮｉとの合計量に対して２〜１０原子％置換
して存在させているため、六方晶構造を乱すことなく、
Ｍｎの位置にその一部が置換されて存在する第３の元素
としてのＮｉが、詳しいメカニズムについては不明であ
るが、電気化学的に結晶構造を安定化させる作用をし
て、腐食環境下における分解が未然に防止され、特に、
酸性雰囲気の腐食環境下において安定となり、分解が未
然に防止される。BEST MODE FOR CARRYING OUT THE INVENTION The MnNiBi alloy magnetic powder of the present invention has an N-position at the Mn position of the hexagonal MnBi alloy magnetic powder.
Since i is made to exist by substituting 2 to 10 atomic% with respect to the total amount of Mn and Ni, without disturbing the hexagonal crystal structure,
Although the detailed mechanism of Ni, which is present as a third element partially present in the Mn position by substitution, is unknown, it acts electrochemically to stabilize the crystal structure, so that it can be used in a corrosive environment. Disassembly is prevented beforehand, especially
It becomes stable in a corrosive environment in an acidic atmosphere and decomposition is prevented in advance.
【０００９】このような六方晶ＭｎＢｉ合金磁性粉末の
Ｍｎの位置に置換されて存在するＮｉの量は、ＭｎとＮ
ｉとの合計量に対して２原子％より少ないと、酸性雰囲
気の腐食環境下における耐食性が充分に向上されず、１
０原子％より多くすると結晶構造が乱れ、磁気特性が著
しく低下して磁気記録媒体用として適さなくなるため、
２〜１０原子％の範囲内にするのが好ましい。[0009] The amount of Ni present in the hexagonal MnBi alloy magnetic powder by substitution at the Mn position is Mn and N.
If it is less than 2 atomic% with respect to the total amount with i, the corrosion resistance in a corrosive environment of an acidic atmosphere will not be sufficiently improved, and 1
If it is more than 0 atom%, the crystal structure will be disturbed and the magnetic properties will be significantly deteriorated, making it unsuitable for magnetic recording media.
It is preferably in the range of 2 to 10 atomic%.
【００１０】また、この種の六方晶ＭｎＢｉ合金磁性粉
末のＭｎの位置にＮｉを置換して存在させたＭｎＮｉＢ
ｉ合金磁性粉末は、平均粒子径が0.５μｍより小さい
と、微細な粉末粒子の割合が増大するため耐食性の低下
が増大し、また、５μｍより大きいと、磁気記録媒体の
表面平滑性の低下による出力の低下が著しいため、平均
粒子径は0.５〜５μｍの範囲内であることが好ましく、
さらに、保磁力は４０００エルステッドより小さいと、
不正使用防止の効果が小さく、１８０００エルステッド
より大きいと、記録電流特性を確保することが困難とな
るため、保磁力は４０００〜１８０００エルステッドの
範囲内であることが好ましい。Further, MnNiB which is present by substituting Ni at the Mn position of this type of hexagonal MnBi alloy magnetic powder
When the average particle diameter of the i alloy magnetic powder is smaller than 0.5 μm, the proportion of fine powder particles increases, so that the corrosion resistance decreases, and when it is larger than 5 μm, the surface smoothness of the magnetic recording medium decreases. Since the output decreases remarkably, the average particle size is preferably within the range of 0.5 to 5 μm,
Furthermore, if the coercive force is less than 4000 Oersted,
If the effect of preventing unauthorized use is small, and if it is larger than 18000 Oersted, it becomes difficult to secure the recording current characteristic. Therefore, the coercive force is preferably in the range of 4000 to 18000 Oersted.
【００１１】このようなＭｎＮｉＢｉ合金磁性粉末は、
図１の液体窒素温度から室温における保磁力の温度依存
性のグラフに示すように、ＭｎＢｉ合金磁性粉末と同じ
性質を有し、室温では保磁力が１００００エルステッド
と高いが、温度が下がると低下して、−１００℃以下で
は１０００エルステッド以下と低くなり、この性質を利
用することにより、低温では容易に消磁でき、消磁後
は、室温で容易に着磁できる。Such MnNiBi alloy magnetic powder is
As shown in the graph of temperature dependence of coercive force from liquid nitrogen temperature to room temperature in FIG. 1, it has the same properties as MnBi alloy magnetic powder, and the coercive force is as high as 10000 Oersted at room temperature, but decreases as the temperature decreases. At −100 ° C. or lower, it becomes as low as 1000 oersted or lower, and by utilizing this property, it is possible to easily demagnetize at low temperature and easily magnetize at room temperature after demagnetization.
【００１２】また、図２はＭｎＮｉＢｉ合金磁性粉末を
用いた磁気記録媒体の初期磁化曲線を示したもので、こ
の図からも明らかなように、ＭｎＢｉ合金磁性粉末と同
じ性質を有し、２０００エルステッド程度の低い磁界で
容易に磁化することができる。また、この磁気記録媒体
は、一度磁化すると１４０００エルステッド程度の高い
保磁力を示すようになり、その後のデ−タの消去や書き
換えがほとんど不可能になる。Further, FIG. 2 shows an initial magnetization curve of a magnetic recording medium using the MnNiBi alloy magnetic powder. As is clear from this figure, it has the same properties as the MnBi alloy magnetic powder and has 2000 Oersted. It can be easily magnetized in a low magnetic field. In addition, this magnetic recording medium exhibits a high coercive force of about 14000 Oersted once magnetized, making it almost impossible to erase or rewrite data thereafter.
【００１３】しかして、このＭｎＮｉＢｉ合金磁性粉末
を用いた磁気記録媒体は、予め−１００℃以下で消去し
てから室温で通常の方法で記録し、次いで安定化処理を
施すことにより記録信号を容易に消去できなくするとい
う記録再生方法に使用され、再記録が極めて困難なた
め、故意の改ざんがほとんど不可能となり、最近社会問
題となっているデ−タ改ざんによるカ−ドの不正使用な
どを防止することができる。However, the magnetic recording medium using this MnNiBi alloy magnetic powder is easily erased at -100 ° C. or less, recorded at room temperature by a usual method, and then subjected to a stabilization treatment to facilitate the recording signal. It is used in a recording and reproducing method that makes it impossible to erase, and since re-recording is extremely difficult, it is almost impossible to intentionally tamper with it, and the unauthorized use of the card due to data tampering has become a social problem recently. Can be prevented.
【００１４】このようなＭｎＮｉＢｉ合金磁性粉末は、
予めＭｎとＮｉをア−ク炉、高周波溶解炉等により合金
インゴットとし、これとＢｉとを粉末冶金法により合金
とし、粉砕することによりつくられ、この他、Ｍｎ，Ｎ
ｉ，Ｂｉの三元合金をア−ク炉、高周波溶解炉、溶融急
冷法等により作製し、これを粉砕することによってもつ
くられる。Such MnNiBi alloy magnetic powder is
The alloy ingot is prepared by previously using Mn and Ni in an arc furnace, a high-frequency melting furnace, etc., and this is alloyed with Bi by powder metallurgy, and crushed.
It can also be produced by producing a ternary alloy of i and Bi by an arc furnace, a high-frequency melting furnace, a melt-quenching method, etc., and crushing this.
【００１５】たとえば、粉末冶金法でＭｎＮｉＢｉイン
ゴットを作製するときは、まず、ア−ク炉を用いてＭｎ
とＮｉの合金を作製する。このときＭｎは予め酸等によ
り表面をエッチングし、表面の酸化物を除去しておくの
が好ましい。また、溶解時の電流値としては、その溶解
量にもよるが、１００Ａから３００Ａが好ましく、充分
に溶解させることが必要であるが電流値が高すぎるとＭ
ｎの蒸気圧が上昇し、組成が仕込み値に比べて変化する
ので好ましくない。For example, when manufacturing an MnNiBi ingot by powder metallurgy, first, an Mn is used in an arc furnace.
And an alloy of Ni are produced. At this time, it is preferable that the surface of Mn is previously etched with an acid or the like to remove the oxide on the surface. The current value at the time of dissolution is preferably 100 A to 300 A, though it depends on the amount of dissolution, and it is necessary to sufficiently dissolve it, but if the current value is too high, M
The vapor pressure of n increases and the composition changes as compared with the charged value, which is not preferable.
【００１６】このようにして得られたＭｎＮｉ合金は、
次いで、酸化を防ぎながら機械的に１００〜３００メッ
シュにまで粉砕し、これと同じく１００〜３００メッシ
ュのＢｉ粉とを不活性雰囲気中にて充分混合する。Ｍｎ
ＮｉとＢｉの比率は、モル比で５０：５０から５５：４
５であることが好ましく、原料とするＢｉ粉としては、
あらかじめ粉砕してあるものを用いてもよいし、フレ−
クあるいはショット等の塊を粉砕により微粉化して用い
てもよい。また、焼結反応により合成する場合には、原
料の表面性に大きく反応が左右されるため、原料表面の
酸化被膜を除去しておくことが好ましく、このためあら
かじめ酸等により表面をエッチングしたり、溶剤により
脱脂するなど、粉末冶金法で行われている表面処理を施
しておくことが好ましい。なお、混合は自動乳鉢、ボ−
ルミル等任意の手段により行うことができる。The MnNi alloy thus obtained is
Then, the powder is mechanically ground to 100 to 300 mesh while preventing oxidation, and Bi powder of 100 to 300 mesh is mixed sufficiently in an inert atmosphere in the same manner. Mn
The molar ratio of Ni and Bi is 50:50 to 55: 4.
5 is preferable, and as the Bi powder used as a raw material,
It is also possible to use those that have been crushed in advance.
A lump such as black or shot may be pulverized into fine powder for use. In the case of synthesis by a sintering reaction, the reaction is greatly affected by the surface properties of the raw material. Therefore, it is preferable to remove the oxide film on the surface of the raw material. It is preferable to perform a surface treatment performed by powder metallurgy, such as degreasing with a solvent. The mixing was performed using an automatic mortar,
It can be performed by any means such as Lumil.
【００１７】混合が終わった原料は、加圧プレスを用い
て成型体とされ、これにより焼結反応が促進され、均一
なＭｎＮｉＢｉインゴットが作製される。このときの加
圧としては、１〜８ｔ／ｃｍ2 とするのが好ましく、加
圧力が低ければＭｎＮｉＢｉインゴットの均一性が得ら
れず、高すぎる場合には、加圧装置が高価となる割りに
ＭｎＮｉＢｉインゴットの特性が向上しない。The raw material after the mixing is formed into a compact by using a pressure press, whereby the sintering reaction is promoted and a uniform MnNiBi ingot is produced. The pressure applied at this time is preferably 1 to 8 t / cm 2, and if the applied pressure is low, the uniformity of the MnNiBi ingot cannot be obtained. If the applied pressure is too high, the pressurizing device is expensive. The characteristics of the MnNiBi ingot are not improved.
【００１８】得られた成型体は、ガラス容器あるいは金
属容器に密封され、容器内は真空あるいは不活性ガス雰
囲気として熱処理中の酸化が防止されて、電気炉に入れ
られ、２６０〜２７０℃で２〜１５日間熱処理が行われ
る。この熱処理の温度が低いと熱処理に時間がかかり、
また、得られるＭｎＮｉＢｉインゴットの磁化量も低く
なる。反対に熱処理温度が高すぎると、Ｂｉが融解し、
均一なＭｎＮｉＢｉインゴットが得られなくなる。The obtained molded body is sealed in a glass container or a metal container, and the inside of the container is placed in an electric furnace at a temperature of 260 to 270 ° C. under a vacuum or an inert gas atmosphere to prevent oxidation during heat treatment. Heat treatment is performed for ~ 15 days. If the temperature of this heat treatment is low, the heat treatment takes time,
Moreover, the amount of magnetization of the obtained MnNiBi ingot is also low. Conversely, if the heat treatment temperature is too high, Bi will melt,
A uniform MnNiBi ingot cannot be obtained.
【００１９】このようにして作製されたＭｎＮｉＢｉイ
ンゴットは、取り出されて自動乳鉢により不活性ガス雰
囲気中で粗粉砕され、粒子サイズを１００〜５００μｍ
とした後、ボ−ルミル、遊星ボ−ルミル等を用いた湿式
粉砕、あるいはジエットミル等の乾式粉砕により微粒子
化される。元々、ＭｎＮｉＢｉは六方晶構造を有するた
め、薄片状に劈開する性質を示し、このため高いエネル
ギ−をかけて粉砕する必要はない。湿式粉砕の場合の液
体としては、トルエン等の水分を含まない溶剤を用い、
乾式粉砕の場合は不活性ガス雰囲気にして行われる。粉
砕後の平均粒子サイズは約0.０５〜３μｍであり、粉砕
条件によりコントロ−ルできる。粒子サイズが0.０５μ
ｍより小さいと、最終的に得られる磁性粉末が充分な磁
気特性を示さなくなり、３μｍを越えると、最終的に得
られる磁性粉末を用いた磁気記録媒体の表面平滑性が低
下し、充分な記録が行えない。粉砕後、酸素を微量含む
不活性ガス雰囲気中で加熱することにより、表面に安定
な酸化被膜を形成することが好ましい。The MnNiBi ingot thus produced was taken out and coarsely crushed in an inert gas atmosphere by an automatic mortar to have a particle size of 100 to 500 μm.
After that, fine particles are formed by wet pulverization using a ball mill, planetary ball mill or the like, or dry pulverization such as a jet mill. Originally, since MnNiBi has a hexagonal crystal structure, it exhibits the property of cleaving into flakes, and therefore, it is not necessary to grind with high energy. As the liquid in the case of wet pulverization, a solvent containing no water such as toluene is used,
In the case of dry pulverization, it is carried out in an inert gas atmosphere. The average particle size after pulverization is about 0.05 to 3 μm, and it can be controlled depending on the pulverization conditions. Particle size is 0.05μ
When it is smaller than m, the finally obtained magnetic powder does not show sufficient magnetic characteristics, and when it exceeds 3 μm, the surface smoothness of the magnetic recording medium using the finally obtained magnetic powder is deteriorated and sufficient recording is performed. Cannot be done. After crushing, it is preferable to form a stable oxide film on the surface by heating in an inert gas atmosphere containing a small amount of oxygen.
【００２０】以上の工程により飽和磁化が２０ｅｍｕ／
ｇ以上あり、保磁力が３０００〜１００００エルステッ
ドのＭｎＮｉＢｉ磁性粉末が得られる。By the above steps, the saturation magnetization is 20 emu /
It is possible to obtain MnNiBi magnetic powder having g or more and coercive force of 3000 to 10,000 Oersted.
【００２１】[0021]
【実施例】次に、この発明の実施例について説明する。 実施例１ Ｍｎフレ−ク（フルウチ化学社製；純度９9.９％）、Ｎ
ｉロッド（フルウチ化学社製；純度９9.９％）を用い、
このＭｎフレ−クを4.８５重量部、Ｎｉロッドを0.１１
重量部秤量して、ア−ク溶解炉（大亜真空技研社製；Ａ
ＣＭ−０１）を用いて溶解し、均一な固溶体を作製し
た。このようにして得られたＭｎＮｉ合金を酸化を防ぎ
ながら機械的に粉砕し、１００メッシュのふるい掛けを
した。EXAMPLES Next, examples of the present invention will be described. Example 1 Mn flakes (Furuuchi Chemical Co., Ltd .; purity 99.9%), N
Using an i-rod (Furuuchi Chemical Co., Ltd .; purity 99.9%),
4.85 parts by weight of this Mn flakes and 0.11 parts of Ni rods
Weigh parts by weight, and arc melting furnace (Dia Vacuum Engineering Co., Ltd .; A
CM-01) was used to dissolve and prepare a uniform solid solution. The MnNi alloy thus obtained was mechanically crushed while preventing oxidization, and sieved with 100 mesh.
【００２２】次いで、Ｂｉショット（フルウチ化学社
製；純度９9.９％）を乳鉢を用いて粉砕し、１００メッ
シュのふるい掛けをした後、このＢｉ粉を8.７重量部、
前記のようにして得られたＭｎＮｉ粉を2.８重量部秤量
し、乳鉢を用いて充分に混合した。Next, Bi shot (Furuuchi Chemical Co., Ltd .; purity 99.9%) was crushed using a mortar and sieved with 100 mesh, and 8.7 parts by weight of this Bi powder was added.
2.8 parts by weight of the MnNi powder obtained as described above was weighed and thoroughly mixed using a mortar.
【００２３】次に、これを加圧プレス機を用いて４ｔ／
ｃｍ2 の圧力で直径×長さが６ｍｍ×６ｍｍの円柱状に
成型し、この成型体をパイレックスガラス管に真空封入
し、電気炉中にて２６５℃で１０日間熱処理して、Ｍｎ
ＮｉＢｉインゴットを作製した。Next, this was pressed at 4 t /
It was molded into a cylinder having a diameter of 6 mm x 6 mm in diameter at a pressure of 2 cm2, and the molded body was vacuum-sealed in a Pyrex glass tube and heat-treated at 265 ° C for 10 days in an electric furnace to obtain Mn.
A NiBi ingot was produced.
【００２４】次いで、得られたＭｎＮｉＢｉインゴット
をグロ−ボックスを使用し、不活性雰囲気中で乳鉢を用
いて粗粉砕し、さらに、遊星ボ−ルミルを用いてトルエ
ン中にて、１５０ｒｐｍで２時間粉砕した。トルエンを
除去した後、１０００ｐｐｍの酸素を含有するＮ2 雰囲
気中で保持することにより安定化処理を行った。このよ
うにして得られたＭｎＮｉＢｉ磁性粉末の平均粒径は、
約２μｍであり、ＶＳＭを用いて測定した磁気特性は、
保磁力が９１００エルステッド、飽和磁化が４6.５ｅｍ
ｕ／ｇ、最大印加磁界は１６Ｋエルステッドであった。Then, the obtained MnNiBi ingot was roughly crushed in a glove box in an inert atmosphere using a mortar, and further pulverized in toluene using a planetary ball mill at 150 rpm for 2 hours. did. After removing the toluene, a stabilizing treatment was carried out by holding it in an N 2 atmosphere containing 1000 ppm of oxygen. The average particle size of the MnNiBi magnetic powder thus obtained is
It is about 2 μm, and the magnetic characteristics measured using VSM are
Coercive force 9100 oersted, saturation magnetization 46.5 em
u / g, the maximum applied magnetic field was 16K oersted.
【００２５】実施例２〜３、比較例１〜６ 実施例１において、ＭｎＮｉ合金作製時に用いるＭｎ
量、Ｎｉ量およびＭｎＮｉＢｉ合金作製時におけるＭｎ
Ｎｉ粉末、Ｂｉ粉末の使用量を、それぞれ下記の表１に
示すように変更した以外は、実施例１と同様にしてＭｎ
ＮｉＢｉ磁性粉末を作製した。Examples 2 to 3 and Comparative Examples 1 to 6 In Example 1, Mn used in the preparation of the MnNi alloy.
Amount, Ni amount, and Mn at the time of producing MnNiBi alloy
Mn was prepared in the same manner as in Example 1 except that the amounts of Ni powder and Bi powder used were changed as shown in Table 1 below.
NiBi magnetic powder was produced.
【００２６】 [0026]
【００２７】図３は、このようにして得られた各実施例
および比較例のＭｎＮｉＢｉ合金磁性粉末およびＭｎＢ
ｉ合金磁性粉末のＸ線回析図であり、このＸ線回析図か
らＮｉが２０原子％を超えると結晶構造が乱れ、単相の
合金磁性粉末を得ることができないことがわかる。FIG. 3 shows the MnNiBi alloy magnetic powders and MnB of the respective Examples and Comparative Examples thus obtained.
It is an X-ray diffraction diagram of the i alloy magnetic powder. From this X-ray diffraction diagram, it is understood that if Ni exceeds 20 atomic%, the crystal structure is disturbed and a single-phase alloy magnetic powder cannot be obtained.
【００２８】また、各実施例および比較例で得られたＭ
ｎＮｉＢｉ合金磁性粉末について、２種の条件下で腐食
テストを行った。第１の腐食条件は、１気圧、６０℃，
９０％の加湿環境下に１日保持し、第２の条件は、５重
量％の酢酸水溶液中に２４時間保持して、それぞれ保持
後の飽和磁化を測定し、初期の飽和磁化に対する減少量
から劣化率を算出して調べた。下記表２はその結果であ
る。Further, M obtained in each example and comparative example
Corrosion tests were performed on the nNiBi alloy magnetic powder under two conditions. The first corrosion condition is 1 atm, 60 ° C,
The second condition was maintained in a humidified environment of 90% for 1 day, and the second condition was maintained in a 5 wt% acetic acid aqueous solution for 24 hours, and the saturation magnetization after each retention was measured. The deterioration rate was calculated and examined. Table 2 below shows the results.
【００２９】 [0029]
【００３０】[0030]
【発明の効果】上記表２から明らかなように、Ｎｉを２
０原子％以上有する比較例２ないし６のＭｎＮｉＢｉ合
金磁性粉末は、初期の飽和磁化が約２９ｅｍｕ／ｇ以下
ともともと低く、記録に適さないが、この発明で得られ
たＭｎＮｉＢｉ合金磁性粉末（実施例１ないし３）は、
初期の飽和磁化が約４０ｅｍｕ／ｇ以上と高く、記録に
適している。また、この発明で得られたＭｎＮｉＢｉ合
金磁性粉末（実施例１ないし３）は、加湿条件下におけ
る磁化減少率が、比較例１のＭｎＢｉ合金磁性粉末とあ
まり変わらず、酢酸テストにおける劣化率は、比較例１
のＭｎＢｉ合金磁性粉末が９9.５％とほとんど磁化が消
失しているのに比べ、この発明で得られたＭｎＮｉＢｉ
合金磁性粉末（実施例１ないし３）は、７０％から９０
％にとどまり、大幅に耐酢酸性が改善されている。これ
らのことから、この発明で得られるＭｎＮｉＢｉ合金磁
性粉末は、特に、酸性雰囲気の腐食環境下において、安
定で分解しにくく、実用に適した耐食性を有し、室温で
容易に消去されることのない情報記録用携帯カ−ド等の
磁気記録媒体に適した磁性粉末であることがわかる。As is clear from Table 2 above, the Ni content is 2%.
The MnNiBi alloy magnetic powders of Comparative Examples 2 to 6 having 0 atomic% or more are low in initial saturation magnetization of about 29 emu / g or less and are not suitable for recording, but the MnNiBi alloy magnetic powders obtained by the present invention (Examples 1 to 3) is
The initial saturation magnetization is as high as about 40 emu / g or more, which is suitable for recording. Further, the MnNiBi alloy magnetic powders obtained in the present invention (Examples 1 to 3) did not show much difference in the magnetization reduction rate under humidified conditions from the MnBi alloy magnetic powder of Comparative Example 1, and the deterioration rate in the acetic acid test was Comparative Example 1
The magnetic powder of MnBi alloy of No. 9 has almost disappeared the magnetization of 99.5%.
The alloy magnetic powder (Examples 1 to 3) contains 70% to 90%.
%, And the acetic acid resistance is greatly improved. From these facts, the MnNiBi alloy magnetic powder obtained in the present invention is stable and hard to decompose, especially in a corrosive environment of an acidic atmosphere, has a corrosion resistance suitable for practical use, and is easily erased at room temperature. It can be seen that the magnetic powder is suitable for a magnetic recording medium such as a portable information recording card.
【図１】液体窒素温度から室温の範囲におけるＭｎＮｉ
Ｂｉ粒子の保磁力の温度依存性を示す保磁力と絶対温度
との関係図である。FIG. 1 MnNi in the range of liquid nitrogen temperature to room temperature
FIG. 4 is a relationship diagram of a coercive force showing the temperature dependence of the coercive force of Bi particles and the absolute temperature.
【図２】ＭｎＮｉＢｉ磁性粉末を長手方向に配向した磁
性層の初期磁化曲線図である。FIG. 2 is an initial magnetization curve diagram of a magnetic layer in which MnNiBi magnetic powder is oriented in the longitudinal direction.
【図３】各実施例および比較例で得られたＭｎＮｉＢｉ
磁性粉末粒子のＸ線回析図である。FIG. 3 shows MnNiBi obtained in each example and comparative example.
It is an X-ray diffraction diagram of magnetic powder particles.
Claims (2)
ｎとＮｉとの合計量に対して２〜１０原子％置換して存
在させたことを特徴とするＭｎＮｉＢｉ合金磁性粉末1. Ni in the position of Mn of hexagonal MnBi is mixed with M
MnNiBi alloy magnetic powder characterized by being present by substituting 2 to 10 atomic% with respect to the total amount of n and Ni.
おける保磁力が４０００〜１８０００エルステッドであ
る請求項１記載のＭｎＮｉＢｉ合金磁性粉末2. The MnNiBi alloy magnetic powder according to claim 1, which has an average particle diameter of 0.5 to 5 μm and a coercive force at 20 ° C. of 4000 to 18000 oersteds.
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|---|---|---|---|
| JP31947595A JP3490201B2 (en) | 1995-11-14 | 1995-11-14 | MnNiBi alloy magnetic powder |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31947595A JP3490201B2 (en) | 1995-11-14 | 1995-11-14 | MnNiBi alloy magnetic powder |
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| Publication Number | Publication Date |
|---|---|
| JPH09139304A true JPH09139304A (en) | 1997-05-27 |
| JP3490201B2 JP3490201B2 (en) | 2004-01-26 |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2015055010A (en) * | 2013-09-12 | 2015-03-23 | トヨタ モーター エンジニアリング アンド マニュファクチャリング ノース アメリカ，インコーポレイティド | METHOD OF PREPARING MANGANESE-BISMUTH ALLOY NANOPARTICLE, MnBi NANOPARTICLE AND HARD MAGNET CONTAINING THE SAME |
| CN107408438A (en) * | 2015-03-06 | 2017-11-28 | 户田工业株式会社 | MnBi based magnetic powders and its manufacture method and bonded permanent magnet mixture, bonded permanent magnet and metallic magnet |
| KR20180101424A (en) | 2016-01-07 | 2018-09-12 | 도다 고교 가부시끼가이샤 | MnBi magnetic powder, process for producing the same, compound for bonded magnet, bonded magnet, MnBi-based metal magnet and manufacturing method thereof |
-
1995
- 1995-11-14 JP JP31947595A patent/JP3490201B2/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2015055010A (en) * | 2013-09-12 | 2015-03-23 | トヨタ モーター エンジニアリング アンド マニュファクチャリング ノース アメリカ，インコーポレイティド | METHOD OF PREPARING MANGANESE-BISMUTH ALLOY NANOPARTICLE, MnBi NANOPARTICLE AND HARD MAGNET CONTAINING THE SAME |
| US10410773B2 (en) | 2013-09-12 | 2019-09-10 | Toyota Motor Engineering & Manufacturing North America, Inc. | Synthesis and annealing of manganese bismuth nanoparticles |
| CN107408438A (en) * | 2015-03-06 | 2017-11-28 | 户田工业株式会社 | MnBi based magnetic powders and its manufacture method and bonded permanent magnet mixture, bonded permanent magnet and metallic magnet |
| KR20180101424A (en) | 2016-01-07 | 2018-09-12 | 도다 고교 가부시끼가이샤 | MnBi magnetic powder, process for producing the same, compound for bonded magnet, bonded magnet, MnBi-based metal magnet and manufacturing method thereof |
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