JPS62219902A - Manufacture of metal magnetic powder - Google Patents
Manufacture of metal magnetic powderInfo
- Publication number
- JPS62219902A JPS62219902A JP61063777A JP6377786A JPS62219902A JP S62219902 A JPS62219902 A JP S62219902A JP 61063777 A JP61063777 A JP 61063777A JP 6377786 A JP6377786 A JP 6377786A JP S62219902 A JPS62219902 A JP S62219902A
- Authority
- JP
- Japan
- Prior art keywords
- nickel
- metal magnetic
- powder
- magnetic powder
- salt
- 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
- 239000006247 magnetic powder Substances 0.000 title claims abstract description 45
- 239000002184 metal Substances 0.000 title claims abstract description 43
- 229910052751 metal Inorganic materials 0.000 title claims abstract description 43
- 238000004519 manufacturing process Methods 0.000 title claims description 5
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims abstract description 50
- 239000000843 powder Substances 0.000 claims abstract description 32
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 25
- 239000002245 particle Substances 0.000 claims abstract description 24
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 claims abstract description 21
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 claims abstract description 20
- 150000002816 nickel compounds Chemical class 0.000 claims abstract description 20
- 239000004202 carbamide Substances 0.000 claims abstract description 19
- 238000010438 heat treatment Methods 0.000 claims abstract description 18
- 150000002815 nickel Chemical class 0.000 claims abstract description 18
- 239000000725 suspension Substances 0.000 claims abstract description 15
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 19
- CUPCBVUMRUSXIU-UHFFFAOYSA-N [Fe].OOO Chemical compound [Fe].OOO CUPCBVUMRUSXIU-UHFFFAOYSA-N 0.000 claims description 10
- 229910021519 iron(III) oxide-hydroxide Inorganic materials 0.000 claims description 10
- 229910052742 iron Inorganic materials 0.000 claims description 9
- 239000002994 raw material Substances 0.000 abstract description 20
- 238000000034 method Methods 0.000 abstract description 17
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 abstract description 10
- 150000003839 salts Chemical class 0.000 abstract description 6
- 239000002131 composite material Substances 0.000 abstract description 4
- 230000007062 hydrolysis Effects 0.000 abstract description 3
- 238000006460 hydrolysis reaction Methods 0.000 abstract description 3
- 229920001807 Urea-formaldehyde Polymers 0.000 abstract description 2
- 239000007864 aqueous solution Substances 0.000 description 8
- 230000000052 comparative effect Effects 0.000 description 7
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 6
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 6
- 239000007789 gas Substances 0.000 description 6
- LGQLOGILCSXPEA-UHFFFAOYSA-L nickel sulfate Chemical compound [Ni+2].[O-]S([O-])(=O)=O LGQLOGILCSXPEA-UHFFFAOYSA-L 0.000 description 6
- 229910000363 nickel(II) sulfate Inorganic materials 0.000 description 6
- 230000007423 decrease Effects 0.000 description 5
- 239000000243 solution Substances 0.000 description 5
- JZQOJFLIJNRDHK-CMDGGOBGSA-N alpha-irone Chemical compound CC1CC=C(C)C(\C=C\C(C)=O)C1(C)C JZQOJFLIJNRDHK-CMDGGOBGSA-N 0.000 description 4
- 238000007796 conventional method Methods 0.000 description 4
- 229910000859 α-Fe Inorganic materials 0.000 description 4
- 229910002092 carbon dioxide Inorganic materials 0.000 description 3
- 239000001569 carbon dioxide Substances 0.000 description 3
- 239000002244 precipitate Substances 0.000 description 3
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 description 3
- 235000012239 silicon dioxide Nutrition 0.000 description 3
- 238000003756 stirring Methods 0.000 description 3
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 2
- 238000007664 blowing Methods 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- SZVJSHCCFOBDDC-UHFFFAOYSA-N ferrosoferric oxide Chemical compound O=[Fe]O[Fe]O[Fe]=O SZVJSHCCFOBDDC-UHFFFAOYSA-N 0.000 description 2
- -1 nickel salt Chemical class 0.000 description 2
- BFDHFSHZJLFAMC-UHFFFAOYSA-L nickel(ii) hydroxide Chemical compound [OH-].[OH-].[Ni+2] BFDHFSHZJLFAMC-UHFFFAOYSA-L 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- POWFTOSLLWLEBN-UHFFFAOYSA-N tetrasodium;silicate Chemical compound [Na+].[Na+].[Na+].[Na+].[O-][Si]([O-])([O-])[O-] POWFTOSLLWLEBN-UHFFFAOYSA-N 0.000 description 2
- 229910021586 Nickel(II) chloride Inorganic materials 0.000 description 1
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical group [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 229910001566 austenite Inorganic materials 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 239000011247 coating layer Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical compound [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 description 1
- 229910021506 iron(II) hydroxide Inorganic materials 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- NCNCGGDMXMBVIA-UHFFFAOYSA-L iron(ii) hydroxide Chemical compound [OH-].[OH-].[Fe+2] NCNCGGDMXMBVIA-UHFFFAOYSA-L 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 230000005415 magnetization Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 230000003472 neutralizing effect Effects 0.000 description 1
- QMMRZOWCJAIUJA-UHFFFAOYSA-L nickel dichloride Chemical compound Cl[Ni]Cl QMMRZOWCJAIUJA-UHFFFAOYSA-L 0.000 description 1
- 229910000480 nickel oxide Inorganic materials 0.000 description 1
- KBJMLQFLOWQJNF-UHFFFAOYSA-N nickel(ii) nitrate Chemical compound [Ni+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O KBJMLQFLOWQJNF-UHFFFAOYSA-N 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- GNRSAWUEBMWBQH-UHFFFAOYSA-N oxonickel Chemical compound [Ni]=O GNRSAWUEBMWBQH-UHFFFAOYSA-N 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 238000004381 surface treatment Methods 0.000 description 1
- 229910006540 α-FeOOH Inorganic materials 0.000 description 1
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
この発明は各種磁気記録媒体の磁気記録素子としてを用
な金属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 manufacturing metal magnetic powder used as a magnetic recording element of various magnetic recording media.
一般に鉄を主体とした金属磁性粉末は、第一鉄塩水溶液
にアルカリ水溶液を加えて生成する水酸化第一鉄の沈澱
物を生成し、これを空気酸化するなどの方法で得られた
針状のα−オキシ水酸化鉄やこれを焼成した針状のγ−
Ｆｅ２Ｏ３あるいはＦｅ３Ｏ４を原料とし、これを加熱
還元して針状の金属鉄とすることにより製造されており
、酸化物系磁性粉末に比較して非常に高い保磁力を備え
ている。しかるに、このような高保磁力の金属磁性粉末
を用いた磁気記録媒体は消去特性および記録再生のポジ
ションなどの面から専用の記録再生機器が必要であるた
め、近年においては酸化物系磁性粉末を用いた磁気記録
媒体との互換性をもたらす消去特性およびポジションに
対応できるように、１．０００工ルステツド程度以下の
保磁力を備えた金属磁性粉末が要望されている。In general, metal magnetic powder mainly composed of iron is produced by adding an alkaline aqueous solution to a ferrous salt aqueous solution to produce a ferrous hydroxide precipitate, which is then oxidized in the air. α-Iron oxyhydroxide and acicular γ-
It is manufactured by using Fe2O3 or Fe3O4 as a raw material and heating and reducing it to form needle-shaped metallic iron, and has a much higher coercive force than oxide-based magnetic powder. However, magnetic recording media using such metal magnetic powders with high coercive force require specialized recording and reproducing equipment in terms of erase characteristics and recording/reproducing positions, so in recent years, oxide-based magnetic powders have been used. There is a need for a metal magnetic powder having a coercive force on the order of 1.000 millimeters or less to accommodate erasing characteristics and positions that provide compatibility with other magnetic recording media.
ところで、鉄を主体とした金属磁性粉末はその粒子中に
ニッケル成分が存在すると保磁力の低下を招くことが知
られている。そこで上記要望に対処する有用な一手段と
してニッケル成分を上記金属磁性粉末に含有させて１，
０００工ルステツド程度以下の適度の保磁力とすること
が考えられる。By the way, it is known that the presence of a nickel component in the particles of metal magnetic powder mainly composed of iron causes a decrease in coercive force. Therefore, as a useful means to meet the above requirements, a nickel component is included in the metal magnetic powder.
It is conceivable to have an appropriate coercive force of about 0,000 millimeters or less.
従来、金属磁性粉末にニッケル成分を含有させる代表的
方法としては、オキシ水酸化鉄または酸化鉄のアルカリ
性懸濁液にニッケル塩の水溶液を添加し、懸濁粒子の表
面に水酸化ニッケルを沈着させ、これを気相中で加熱還
元することにより、粉末粒子表面にニッケルまたはその
化合物からなる被覆層を有する金属磁性粉末を得る方法
が提案されている（特願昭５７−１４１３９９号）。Conventionally, a typical method for incorporating nickel into metal magnetic powder is to add an aqueous solution of nickel salt to an alkaline suspension of iron oxyhydroxide or iron oxide, and deposit nickel hydroxide on the surface of the suspended particles. A method has been proposed in which a metal magnetic powder having a coating layer of nickel or its compound on the surface of the powder particles is obtained by thermally reducing the nickel in a gas phase (Japanese Patent Application No. 141399/1983).
しかしながら、上記提案法によって保磁力が、１、００
０エルステツド以下の金属磁性粉末を得ようとする場合
、多量のニッケルを添加する必要があり、これにより針
状形状の崩壊を伴う軸比の低下ならびに角型（σｒ／σ
Ｓ）の大幅な低下を招くという問題点があった。However, the above proposed method reduces the coercive force to 1,00
When trying to obtain metal magnetic powder with a particle size of 0 oersted or less, it is necessary to add a large amount of nickel, which causes a decrease in the axial ratio accompanied by the collapse of the acicular shape and a square shape (σr/σ
There was a problem in that it caused a significant decrease in S).
したがって、この発明は、上記問題点を解決し、少量の
ニッケルの添加により保磁力が低く良好な針状形状およ
び角型を有する金属磁性粉末を得る方法を提供すること
を目的としている。Therefore, an object of the present invention is to solve the above-mentioned problems and provide a method for obtaining a metal magnetic powder having a low coercive force and a good acicular shape and square shape by adding a small amount of nickel.
〔問題点を解決するための手段〕
この発明者らは、上記目的において鋭意検討を重ねた結
果、原料であるオキシ水酸化鉄または酸化鉄を主体とす
る粉末にニッケル成分を付着させるにあたり、ニッケル
塩と特定成分とを上記粉末の懸濁液中に存在させて加熱
する方法を採用することにより、上記ニッケル塩の使用
量を少なくしても最終的に得られる金属磁性粉末の保磁
力が非常に低くなり、かつ針状形状が損なわれず高軸比
で角型も良好となることを見い出し、この発明をなすに
至った。[Means for Solving the Problems] As a result of intensive studies for the above-mentioned purpose, the inventors found that when attaching a nickel component to powder mainly composed of iron oxyhydroxide or iron oxide, which is a raw material, nickel By adopting a method in which the salt and specific components are present in a suspension of the above-mentioned powder and then heated, the coercive force of the final metal magnetic powder obtained is extremely high even if the amount of the above-mentioned nickel salt used is reduced. The inventors have discovered that the angular shape can be improved with a high axial ratio without impairing the acicular shape, and have achieved this invention.
すなわちこの発明は、オキシ水酸化鉄または酸化鉄を主
体とした粉末の懸濁液をニッケル塩と尿素の存在下で８
０℃以上に加熱して上記粉末の粒子表面にニッケル化合
物を付着させたのち、この粉末を気相中で加熱還元して
ニッケルを主体とした金属磁性粉末を得ることを特徴と
する金属磁性粉末の製造方法に係る。That is, in this invention, a suspension of powder mainly composed of iron oxyhydroxide or iron oxide is heated to 80% in the presence of nickel salt and urea.
A metal magnetic powder characterized in that a nickel compound is attached to the particle surface of the powder by heating to 0°C or higher, and then the powder is heated and reduced in a gas phase to obtain a metal magnetic powder mainly composed of nickel. It pertains to the manufacturing method.
この発明方法の特徴点は、上述の如く、金属磁性粉末の
原料となるオキシ水酸化鉄または酸化鉄を主体とした粉
末にニッケル化合物を付着させるために、上記原料粉末
の懸濁液をニッケル塩と尿素の存在下で８０℃以上に加
熱することにある。The feature of the method of this invention is that, as mentioned above, in order to attach a nickel compound to powder mainly composed of iron oxyhydroxide or iron oxide, which is the raw material for metal magnetic powder, a suspension of the raw material powder is mixed with nickel salt. and heating to 80°C or higher in the presence of urea.
すなわち、ニッケル塩と尿素とは水′中において安定な
複合塩を形成しているが、この複合塩が８０℃以上の加
熱によって加水分解し、懸濁しているオキシ水酸化鉄ま
たは酸化鉄を主体としな粉末の粒子表面にニッケル化合
物が付着される。そしてこのニッケル化合物を付着した
原料粉末を常法に準じて気相中で加熱還元して得られる
金属磁性粉末は、ニッケルの含有量が少なくても低い保
磁力を有するものとなる。したがって、この発明方法に
よれば１．０００工ルステツド程度以下の低い保磁力を
備えてかつ高軸比で角型も良好な針状粒子からなる金属
磁性粉末が容易に得られる。In other words, nickel salt and urea form a stable composite salt in water, but this composite salt is hydrolyzed by heating above 80°C, and the suspended iron oxyhydroxide or iron oxide becomes the main component. A nickel compound is attached to the surface of the toshina powder particles. The metal magnetic powder obtained by heating and reducing the raw material powder to which the nickel compound is attached in a gas phase according to a conventional method has a low coercive force even if the nickel content is small. Therefore, according to the method of the present invention, a metal magnetic powder comprising acicular particles having a low coercive force of about 1.000 millimeters or less, a high axial ratio, and a good square shape can be easily obtained.
上述のようにこの発明方法によってニッケルの含有量が
少なくても低い保磁力の金属磁性粉末が得られる理由は
明確ではないが、オキシ水酸化鉄または酸化鉄を主体と
した粉末の粒子表面にニッケル化合物を被着させる場合
、既述提案法の如くニッケル塩にアルカリを作用させる
よりも、尿素の存在下での加水分解の方が形成されるニ
ッケル化合物の沈澱が均一になり、粒子表面に均質にニ
ッケル化合物が沈着する結果、最終的に得られる金属磁
性粉末の粒子内部にニッケルがより均一に分布する状態
になるためと推測される。As mentioned above, it is not clear why a metal magnetic powder with a low coercive force can be obtained even with a small nickel content by the method of this invention, but it is possible to When depositing a compound, hydrolysis in the presence of urea makes the precipitate of the nickel compound more uniform than that of applying an alkali to the nickel salt as in the previously proposed method, resulting in a more uniform precipitate of the nickel compound on the particle surface. It is presumed that this is because nickel is more uniformly distributed inside the particles of the finally obtained metal magnetic powder as a result of the nickel compound being deposited on the particles.
この発明において使用する上記ニッケル塩としてはこれ
と尿素とを含む水溶液を酸性とする硫酸ニッケル、硝酸
ニッケル、塩化ニッケルなどが好適であり、これらは既
述の如く水中において尿素との間で安定な複合塩を形成
する。As the nickel salt used in this invention, nickel sulfate, nickel nitrate, nickel chloride, etc., which make an acidic aqueous solution containing the nickel salt and urea, are suitable, and as mentioned above, these are stable with urea in water. Forms complex salts.
このようなニッケル塩と尿素との使用割合は、ニッケル
塩／尿素のモル比で０．５〜５程度とするのがよく、尿
素が多すぎるとニッケル化合物の沈澱化に使用されない
尿素が多くなり、効率が悪くなる。また尿素が少なすぎ
ると加熱によるニッケル化合物の原料粉末の粒子表面へ
の付着がうまく進まない。The ratio of nickel salt and urea to be used is preferably about 0.5 to 5 in molar ratio of nickel salt/urea; if there is too much urea, a lot of urea will not be used for precipitation of the nickel compound. , efficiency becomes worse. Moreover, if the amount of urea is too small, the adhesion of the raw material powder of the nickel compound to the particle surface due to heating will not proceed properly.
またニッケル塩の使用量は、必要とする金属磁性粉末の
保磁力、軸比、角型などによって異なるが、磁気記録媒
体の消去特性などに好結果を与える１、 ｏ ｏ ｏエ
ルステッド程度以下の保磁力を有する金属磁性粉末を対
象とする場合、原料のオキシ水酸化鉄または酸化鉄を主
体とした粉末１００重量部に対して１０〜８０重量部程
度とするのがよい。The amount of nickel salt to be used varies depending on the coercive force, axial ratio, square shape, etc. of the metal magnetic powder required, but it is necessary to obtain a coercive force of less than 1,000 Oersted, which gives good results for the erasing characteristics of the magnetic recording medium. When the target is metal magnetic powder having magnetic force, the amount is preferably about 10 to 80 parts by weight per 100 parts by weight of powder mainly composed of iron oxyhydroxide or iron oxide as a raw material.
なお、ニッケル塩と尿素とを原料粉末の懸濁液中に存在
させる手段としては、通常ニッケル塩と尿素とを含む水
溶液中に原料粉末を添加して懸濁液とする方法が採用さ
れるが、原料粉末を水中に懸濁した液中にニッケル塩と
尿素とを添加混合しても差し支えない。In addition, as a means for making the nickel salt and urea exist in the suspension of the raw material powder, a method is usually adopted in which the raw material powder is added to an aqueous solution containing the nickel salt and urea to form a suspension. , nickel salt and urea may be added and mixed into a solution in which the raw material powder is suspended in water.
この発明では既述の如く原料粉末の懸濁液をニッケル塩
と尿素の存在下で８０℃以上に加熱することにより原料
粉末の粒子表面にニッケル化合物を付着させるが、この
加熱温度が８０℃より低（なると、加水分解がうまく起
こらず、ニッケル化合物の付着を定量的に行うことが困
難になるので好ましくない。なお、上記付着したニッケ
ル化合物は明確ではないが水酸化ニッケルないし酸化ニ
ッケルの形態であるものと推定される。In this invention, as described above, a nickel compound is attached to the particle surface of the raw material powder by heating the suspension of the raw material powder to 80°C or higher in the presence of nickel salt and urea, but this heating temperature is higher than 80°C. This is not desirable because hydrolysis does not occur well and it becomes difficult to quantify the adhesion of nickel compounds.Although it is not clear that the nickel compounds adhered above are in the form of nickel hydroxide or nickel oxide, It is estimated that there is.
一方、原料粉末であるオキシ水酸化鉄または酸化鉄とし
ては、たとえば第一鉄塩水溶液とアルカリとから生成す
る水酸化第一鉄を空気酸化して得られるα−オキシ水酸
化鉄（α−ＦｅＯＯＨ）などの種々の方法で得られた針
状粒子からなるオキシ水酸化鉄、ならびにこれを焼成し
て得られる針状粒子からなるγ−Ｆｅ、Ｏ８またはＦｅ
：１０４あるいはこれらの中間的酸化物が挙げられる。On the other hand, as the raw material powder iron oxyhydroxide or iron oxide, for example, α-iron oxyhydroxide (α-FeOOH ) Iron oxyhydroxide consisting of acicular particles obtained by various methods such as γ-Fe, O8 or Fe consisting of acicular particles obtained by firing the iron oxyhydroxide
:104 or intermediate oxides thereof.
そしてこれらは軸比３〜１５、平均長軸径０．０５〜１
μｍ程度のものが好適である。And these have an axial ratio of 3 to 15 and an average major axis diameter of 0.05 to 1.
A thickness on the order of μm is suitable.
この発明では、上述のようにして得られたニッケル化合
物を付着した原料粉末を常法に準じて加熱還元すること
により、ニッケルを含有する鉄を主体とした金属磁性粉
末とする。In this invention, the raw material powder to which the nickel compound adhered obtained as described above is heated and reduced in accordance with a conventional method to obtain a metal magnetic powder mainly composed of iron containing nickel.
この場合、上記加熱還元の前に原料粉末の粒子表面にケ
イ酸被膜を形成する表面処理を施してもよい。すなわち
ケイ酸被膜は加熱還元に際して粉末粒子相互間の焼結を
防ぎ、原料粉末の針状形状を保つ機能を示し、最終的に
得られる金属磁性粉末の磁気特性に好結果を与える。こ
の処理手段としては、たとえばニッケル化合物を付着し
た原料粉末を水中に再分散させ、この懸濁液中に水溶性
ケイ酸塩を添加混合したのち、炭酸ガスを吹き込んで中
和する方法がある。なおケイ酸の付着量は金属鉄に対す
るケイ素原子換算重量が０．１〜１５重量％となるよう
にするのがよい。In this case, a surface treatment may be performed to form a silicic acid film on the particle surface of the raw material powder before the thermal reduction. In other words, the silicic acid coating prevents sintering between powder particles during thermal reduction and maintains the acicular shape of the raw material powder, giving good results to the magnetic properties of the finally obtained metal magnetic powder. As a method for this treatment, for example, there is a method of redispersing the raw material powder to which the nickel compound is attached in water, adding and mixing a water-soluble silicate to this suspension, and then neutralizing it by blowing carbon dioxide gas. The amount of silicic acid deposited is preferably 0.1 to 15% by weight in terms of silicon atoms relative to metal iron.
またこの発明においては通常、上記加熱還元に先立って
３００〜１．０００℃程度で加熱処理することが推奨さ
れる。すなわち、この加熱処理によって原料粉末の粒子
表面に付着したニッケル化合物が完全な酸化物になると
共に、加熱還元時に鉄とニッケルとが合金化され易くな
る。Further, in the present invention, it is usually recommended to perform a heat treatment at about 300 to 1,000°C prior to the above-mentioned thermal reduction. That is, by this heat treatment, the nickel compound attached to the particle surface of the raw material powder becomes a complete oxide, and at the same time, iron and nickel are easily alloyed during thermal reduction.
このような加熱処理後に行う上記加熱還元は、一般に水
素ガス中３００〜６００℃程度の温度とすればよい。そ
してこの加熱還元を経ることによって原料粉末はニッケ
ルを含む鉄を主体とした金属磁性粉末となる。The above-mentioned thermal reduction performed after such heat treatment may generally be carried out at a temperature of about 300 to 600° C. in hydrogen gas. Through this thermal reduction, the raw material powder becomes a metal magnetic powder mainly composed of iron containing nickel.
なお、このようにして得られる金属磁性粉末は、その酸
化安定性を向上させるために、トルエンなどの有機溶媒
中に分散させてこれに空気を吹き込むなどの方法によっ
て粒子表面に薄い酸化被膜を設けることが望ましい。In order to improve the oxidation stability of the metal magnetic powder obtained in this way, a thin oxide film is formed on the particle surface by dispersing it in an organic solvent such as toluene and blowing air into it. This is desirable.
この発明の製造方法により得られるニッケルを含む鉄を
主体とした金属磁性粉末は、上記ニッケルの含有量が少
なくても低い保磁力を有し、かつ針状形状が損なわれず
高軸比で角型も良好なものとなる。したがって、この発
明によれば磁気記録媒体の消去特性や記録再生における
ポジション面より有用な１．ＯＱＯエルステッド程度以
下の磁気特性にすぐれる金属磁性粉末を容易に製造する
ことができる。The metal magnetic powder mainly composed of iron containing nickel obtained by the production method of the present invention has a low coercive force even if the nickel content is low, and has a square shape with a high axial ratio without losing its acicular shape. will also be good. Therefore, according to the present invention, 1. Metal magnetic powder having excellent magnetic properties of OQO Oersted or less can be easily produced.
以下、この発明の実施例を比較例と対比して説明する。 Examples of the present invention will be described below in comparison with comparative examples.
実施例１
硫酸ニッケル１．５０ ｇと尿素３．４２ ｇを水２０
０ ｍ １２に溶解させ、これに平均長軸径０．５μｍ
、軸比１５のα−オキシ水酸化鉄１００ｇを加えて懸濁
させた。次いでこの懸濁液を９０℃で６時間加熱した。Example 1 1.50 g of nickel sulfate and 3.42 g of urea were mixed with 20 g of water.
0 m 12 and an average major axis diameter of 0.5 μm.
, 100 g of α-iron oxyhydroxide having an axial ratio of 15 was added and suspended. This suspension was then heated at 90° C. for 6 hours.
そののち、懸濁物を充分水洗し、１゜０℃で乾燥し、さ
らに５００ｍｌの水中に懸濁させ、０．５モルのオルト
ケイ酸ナトリウム水溶液３５、５ ｍ ｌを一時に加え
て１０分間攪拌したのち、炭酸ガスをＩＮ／分の割合で
液のｐＨが８以下となるまで吹き込んだ。次に懸濁物を
充分水洗し、１００℃で乾燥したのち、この乾燥物をマ
ツフル炉中で８００℃で加熱処理し、さらに導入量１２
／分の水素気流中で５００℃にて４時間の加熱還元処理
を行った。次に還元物をトルエン中に浸漬し、攪拌しな
がら空気を吹き込んで粒子表面に薄い酸化被膜を形成し
、金属磁性粉末を得た。Thereafter, the suspension was thoroughly washed with water, dried at 1°0°C, further suspended in 500 ml of water, and 35.5 ml of a 0.5 mol sodium orthosilicate aqueous solution was added at once and stirred for 10 minutes. Thereafter, carbon dioxide gas was blown into the solution at a rate of IN/min until the pH of the solution became 8 or less. Next, the suspended matter was thoroughly washed with water and dried at 100°C, and then the dried product was heat-treated at 800°C in a Matsufuru furnace, and the amount introduced was 12°C.
Thermal reduction treatment was performed at 500° C. for 4 hours in a hydrogen flow of 1/min. Next, the reduced product was immersed in toluene, and air was blown in while stirring to form a thin oxide film on the particle surface, thereby obtaining metal magnetic powder.
実施例２
硫酸ニッケルの使用量を３．００ ｇ、尿素の使用量を
６．８４ ｇとした以外は実施例１と同様にして金属磁
性粉末を得た。Example 2 Metal magnetic powder was obtained in the same manner as in Example 1, except that the amount of nickel sulfate used was 3.00 g, and the amount of urea used was 6.84 g.
実施例３
硫酸ニッケルの使用量を６．ＯＯｇ、尿素の使用量を１
３．６８ｇとした以外は実施例１と同様にして金属磁性
粉末を得た。Example 3 The amount of nickel sulfate used was 6. OOg, the amount of urea used is 1
A metal magnetic powder was obtained in the same manner as in Example 1 except that the amount was 3.68 g.
比較例１
ニッケル化合物の付着処理を行わなかった以外は実施例
１と同様にして金属磁性粉末を得た。Comparative Example 1 Metal magnetic powder was obtained in the same manner as in Example 1 except that the nickel compound adhesion treatment was not performed.
比９例２
実施例１と同様のα−オキシ水酸化鉄１０ｇを含むｐ
Ｈ１１以上のアルカリ性懸濁液８００ｍｌを調製し、こ
の液中に攪拌下で０．１モルの硫酸ニッケル水溶液５７
．１ ｍ ｌを２．５ ｍ Ｉｔ／分の割合で滴下した
のち、０．５モルのオルトケイ酸ナトリウム水溶液３５
．６ ｍ ｊ！を一時に加え、さらに１０分間攪拌を続
けたのち、炭酸ガスを１１７分の割合で液のｐＨが８以
下となるまで吹き込んだ。つぎに懸濁物を充分に水洗し
たのち吸引ろ過し、１００℃で乾燥した。この乾燥物を
用いて実施例１と同様に加熱処理、加熱還元処理、酸化
被膜形成処理を施し、金属磁性粉末を得た。Ratio 9 Example 2 P containing 10 g of α-iron oxyhydroxide similar to Example 1
Prepare 800 ml of an alkaline suspension of H11 or higher, and add 0.1 mol of nickel sulfate aqueous solution 57 to this solution while stirring.
．． After dropping 1 ml at a rate of 2.5 m It/min, 0.5 mol of sodium orthosilicate aqueous solution 35
．． 6 m j! was added at once, stirring was continued for another 10 minutes, and then carbon dioxide gas was blown into the solution at a rate of 117 minutes until the pH of the liquid became 8 or less. Next, the suspension was thoroughly washed with water, filtered under suction, and dried at 100°C. This dried material was subjected to heat treatment, heat reduction treatment, and oxide film forming treatment in the same manner as in Example 1 to obtain metal magnetic powder.
比較例３
硫酸ニッケルの使用量を１１４．２ｍＡ！、滴下割合を
２．５ ｍ ｉ！ ／分とした以外は比較例２と同様に
して金属磁性粉末を得た。Comparative Example 3 The amount of nickel sulfate used was 114.2mA! , the dropping rate was 2.5 m i! A metal magnetic powder was obtained in the same manner as in Comparative Example 2 except that the heating time was changed to /min.
以上の実施例および比較例にて得られた金属磁性粉末の
平均長軸径、軸比、保磁力（Ｈｃ）、飽和磁化ｆｆ１（
σＳ）、角型σｒ／σＳを測定した結果を、各実施例お
よび比較例におけるニッケル塩の使用量（Ｎｉ／α−Ｆ
ｅＯＯＨ重量％）と共に下表で示す。The average major axis diameter, axial ratio, coercive force (Hc), and saturation magnetization ff1(
σS) and the square shape σr/σS are calculated based on the amount of nickel salt used (Ni/α-F
It is shown in the table below along with eOOH weight %).
上表から明らかなように、この発明方法によれば、ニッ
ケルの含有量が少な（でも（実施例１）１．０００工ル
ステツド程度の低い保磁力を有する金属磁性粉末が得ら
れ、しかもこの金属磁性粉末は通常の加熱還元にて得ら
れるニッケルを含まない金属磁性粉末（比較例１）と同
等の平均長軸径および軸比を有し、かつ角型も良好であ
る。これに対して、従来の方法にてニッケルを含有させ
た場合は、ニッケルの含有量が少ない（比較例２）と保
磁力の低下が少なく、しかも平均長軸径および軸比が小
さくなって針状形状の崩壊が生じていることが判る。さ
らに、ニッケル含有量を増大させた場合、この発明によ
る金属磁性粉末（実施例２）に比較して、従来方法によ
る金属磁性粉末（比較例３）は保磁力の低下が少ないに
もかかわらず、角型が著しく悪化し、かつ粒子形状の崩
壊が大きいことが判る。As is clear from the above table, according to the method of the present invention, a metal magnetic powder having a low nickel content ((Example 1) but a low coercive force of about 1,000 milliseconds) can be obtained. The magnetic powder has the same average major axis diameter and axial ratio as the nickel-free metal magnetic powder obtained by normal thermal reduction (Comparative Example 1), and also has a good square shape. When nickel is added using the conventional method, the lower the nickel content (comparative example 2), the less the coercive force decreases, and the average major axis diameter and axial ratio become smaller, preventing the collapse of the acicular shape. Furthermore, when the nickel content is increased, the coercive force of the metal magnetic powder produced by the conventional method (Comparative Example 3) decreases compared to the metal magnetic powder produced by the present invention (Example 2). It can be seen that even though the particle size is small, the square shape is significantly deteriorated and the particle shape is greatly disrupted.
Claims (1)
懸濁液をニッケル塩と尿素の存在下で８０℃以上に加熱
して上記粉末の粒子表面にニッケル化合物を付着させた
のち、この粉末を気相中で加熱還元してニッケルを含有
する鉄を主体とした金属磁性粉末を得ることを特徴とす
る金属磁性粉末の製造方法。(1) After heating a suspension of powder mainly composed of iron oxyhydroxide or iron oxide to 80°C or higher in the presence of nickel salt and urea to attach a nickel compound to the particle surface of the powder, A method for producing metal magnetic powder, which comprises heating and reducing the powder in a gas phase to obtain a metal magnetic powder mainly composed of iron containing nickel.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61063777A JPS62219902A (en) | 1986-03-20 | 1986-03-20 | Manufacture of metal magnetic powder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61063777A JPS62219902A (en) | 1986-03-20 | 1986-03-20 | Manufacture of metal magnetic powder |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS62219902A true JPS62219902A (en) | 1987-09-28 |
Family
ID=13239141
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61063777A Pending JPS62219902A (en) | 1986-03-20 | 1986-03-20 | Manufacture of metal magnetic powder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62219902A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100507638B1 (en) * | 2002-11-29 | 2005-08-10 | 한국화학연구원 | A method for producing ultrafine spherical nickel particles |
-
1986
- 1986-03-20 JP JP61063777A patent/JPS62219902A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100507638B1 (en) * | 2002-11-29 | 2005-08-10 | 한국화학연구원 | A method for producing ultrafine spherical nickel particles |
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