JPH0575807B2 - - Google Patents

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Publication number
JPH0575807B2
JPH0575807B2 JP61314169A JP31416986A JPH0575807B2 JP H0575807 B2 JPH0575807 B2 JP H0575807B2 JP 61314169 A JP61314169 A JP 61314169A JP 31416986 A JP31416986 A JP 31416986A JP H0575807 B2 JPH0575807 B2 JP H0575807B2
Authority
JP
Japan
Prior art keywords
particles
magnetic
iron
isotropic shape
particle size
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.)
Expired - Lifetime
Application number
JP61314169A
Other languages
Japanese (ja)
Other versions
JPS63162802A (en
Inventor
Tatsuya Nakamura
Harumi Kurokawa
Hiromitsu Misawa
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toda Kogyo Corp
Original Assignee
Toda Kogyo Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Toda Kogyo Corp filed Critical Toda Kogyo Corp
Priority to JP61314169A priority Critical patent/JPS63162802A/en
Publication of JPS63162802A publication Critical patent/JPS63162802A/en
Publication of JPH0575807B2 publication Critical patent/JPH0575807B2/ja
Granted legal-status Critical Current

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  • Compounds Of Iron (AREA)
  • Manufacture Of Metal Powder And Suspensions Thereof (AREA)
  • Hard Magnetic Materials (AREA)

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、等方的形状を呈した鉄を主成分とす
る金属磁性粒子粉末の製造法、詳しくは、高い保
磁力Hcと大きな飽和磁化σsを有し、しかも、粒
度が均斉である等方的形状を呈した鉄を主成分と
する金属磁性粒子粉末の製造法に関するものであ
る。
[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing metal magnetic particles having an isotropic shape and having iron as a main component. The present invention relates to a method for producing metal magnetic particles containing iron as a main component, which have an isotropic shape with a uniform particle size and have σs.

本発明によつて製造される等方的形状を呈した
鉄を主成分とする金属磁性粒子粉末の主な用途
は、静電複写用の磁性トナー用材料粉末及び磁気
記録用磁性粒子粉末である。
The main uses of the iron-based metal magnetic particles having an isotropic shape produced by the present invention are as material powder for magnetic toner for electrostatic copying and as magnetic particle powder for magnetic recording. .

〔従来の技術〕[Conventional technology]

近年における静電複写機の普及はめざましく、
それに伴い、現像剤である磁性トナーの研究開発
が盛んであり、その特性向上が要求されている。
The spread of electrostatic copying machines has been remarkable in recent years.
Along with this, research and development of magnetic toner, which is a developer, is active, and improvements in its properties are required.

磁性トナーは、一般に、等方的形状を呈した磁
性粒子粉末を合成樹脂中に分散させることにより
製造されるが、その特性向上の為には、材料粉末
である磁性粒子粉末が、高い保磁力Hcと大きな
飽和磁化σsを有し、しかも、粒度が均斉であるこ
とが必要である。
Magnetic toner is generally produced by dispersing isotropically shaped magnetic particles in a synthetic resin, but in order to improve its properties, the material powder, the magnetic particles, must have a high coercive force. It is necessary to have Hc and a large saturation magnetization σs, and the grain size must be uniform.

この現象は、例えば、特公昭57−60765号公報
の「……搬送性の向上の為には、磁性トナー粒子
の磁化の強さ、即ち、残留磁束Brが高いことが
必要であり、そのような特性を有する磁気トナー
粒子を得る為には該磁気トノーの原料である粒状
磁性粒子粉末ができるだけ大きな飽和磁化σsと高
い抗磁力Hcを有することが必要である。……」
なる記載及び特公昭53−21656号公報の「……酸
化鉄を現像剤粒子全体に均一に分散させることに
より静電潜像の顕像化に必要な帯磁性を得……」
なる記載の通りである。
This phenomenon is explained, for example, in Japanese Patent Publication No. 57-60765, "...In order to improve conveyance, it is necessary that the strength of magnetization of magnetic toner particles, that is, the residual magnetic flux Br, be high. In order to obtain magnetic toner particles with such characteristics, it is necessary that the granular magnetic particle powder, which is the raw material for the magnetic tonneau, has as large a saturation magnetization σs as possible and a high coercive force Hc.
and the description in Japanese Patent Publication No. 53-21656, ``...By uniformly dispersing iron oxide throughout the developer particles, the magnetic susceptibility necessary for visualizing the electrostatic latent image is obtained...''
This is as described.

一方、磁気的に等方性である磁気記録媒体、特
に、フロツピーデイスクはオフイスコンピユータ
ーやワードプロセツサー等の普及に伴い情報の入
出力用磁気記録媒体として広く用いられている。
フロツピーデイスクは、一般にソノシート状のポ
リエステルベースの片面或いは両面に等方的形状
を呈した磁性粒子粉末がコーテイングされたデイ
スクである。
On the other hand, magnetically isotropic magnetic recording media, especially floppy disks, are widely used as magnetic recording media for inputting and outputting information with the spread of office computers, word processors, and the like.
A floppy disk is generally a disk in which one or both sides of a sonosheet-like polyester base is coated with isotropically shaped magnetic particles.

近時、磁気記録再生機器の小型軽量化が進むに
つれて磁気記録媒体であるフロツピーデイスクに
対する高性能化の必要性が益々生じてきている。
即ち、高記録密度特性及び高出力特性が要求され
ている。
In recent years, as magnetic recording and reproducing equipment has become smaller and lighter, there has been an increasing need for higher performance in floppy disks, which are magnetic recording media.
That is, high recording density characteristics and high output characteristics are required.

磁気記録媒体の上記の要求を満足させる為に適
した等方的形状を呈した磁性粒子粉末の特性は、
高い保磁力Hcと大きな飽和磁化σsとを有し、し
かも、粒度が均斉であることである。この現象
は、例えば、特公昭61−31057号公報に「……高
記録密度特性、高出力特性……が要求されてい
る。フロツピーデイスクに対する上記の要求を満
足させる為に適した磁気記録用磁性粒子粉末の特
性は、高い保磁力Hcと大きな飽和磁化σs……を
有し、……」なる記載及び株式会社総合技術セン
ター発行「磁性材料の開発と磁粉の高分散化技
術」(1982年)の第74頁の「……高密度記録のた
めの要因を克服するために課せられる磁性塗膜層
の設計上の大きな課題は、(1)磁性粒子の均一分散
……という点である。」なる記載の通りである。
The characteristics of magnetic particles with an isotropic shape suitable for satisfying the above requirements for magnetic recording media are as follows:
It has a high coercive force Hc and a large saturation magnetization σs, and the grain size is uniform. This phenomenon is explained, for example, in Japanese Patent Publication No. 61-31057, which states that ``...high recording density characteristics and high output characteristics are required.'' In order to satisfy the above requirements for floppy disks, suitable magnetic recording The characteristics of magnetic particles are as follows: "They have a high coercive force Hc and a large saturation magnetization σs..." and "Development of Magnetic Materials and Highly Dispersed Magnetic Powder Technology" published by Sogo Technological Center Co., Ltd. (1982) ), page 74, ``...The major challenges in the design of magnetic coating layers to overcome the factors for high-density recording are (1) uniform dispersion of magnetic particles... ” as stated.

上述した通り、等方的形状を呈した磁性粒子粉
末は、様々の分野で使用されているが、いずれの
分野においても共通して要求される磁性粒子粉末
の特性は、高い保磁力Hcと大きな飽和磁化σsと
を有し、しかも粒度が均斉であることである。
As mentioned above, magnetic particles with an isotropic shape are used in various fields, but the characteristics commonly required for magnetic particles in all fields are high coercive force Hc and large It has a saturation magnetization σs and a uniform grain size.

等方的形状を呈した磁性粒子粉末としては、一
般に、マグネタイト粒子、マグヘマイト粒子等の
酸性酸化鉄粒子が広く使用されているが、近年、
磁気トナー、磁気記録媒体の高性能化に伴い、こ
れら磁性酸化鉄粒子に比べ、高い保磁力Hcと大
きな飽和磁化σsとを有する等方的形状を呈した鉄
を主成分とする金属磁性粒子粉末が注目を浴びて
おり、該粒子の特性向上が強く要求されている。
Generally, acidic iron oxide particles such as magnetite particles and maghemite particles are widely used as magnetic particles exhibiting an isotropic shape.
As the performance of magnetic toners and magnetic recording media improves, metal magnetic particles whose main component is iron and which exhibit an isotropic shape and have a higher coercive force Hc and a larger saturation magnetization σs than these magnetic iron oxide particles. are attracting attention, and there is a strong demand for improving the properties of these particles.

従来、等方的形状を呈した鉄を主成分とする金
属磁性粒子粉末の製造法としては、第一鉄塩水溶
液とアルカリとを反応させて得られた水酸化第一
鉄を含む反応水溶液に酸素含有ガスを通気するこ
とにより、水溶液中からマグネタイト粒子を生成
させ、該マグネタイト粒子粉末を還元性ガス中で
加熱還元する方法が知られている。
Conventionally, the method for producing isotropically shaped metal magnetic particles containing iron as a main component involves reacting a reaction aqueous solution containing ferrous hydroxide obtained by reacting an aqueous ferrous salt solution with an alkali. A method is known in which magnetite particles are generated from an aqueous solution by passing an oxygen-containing gas through the solution, and the magnetite particles are reduced by heating in a reducing gas.

〔発明が解決しようとする問題点〕[Problem that the invention seeks to solve]

高い保磁力Hcと大きな飽和磁化σsとを有し、
しかも、粒度が均斉である等方的形状を呈した鉄
を主成分とする金属磁性粒子粉末は、現在最も要
求されているところであるが、上述した通りの公
知方法により得られた等方的形状を呈した鉄を主
成分とする金属磁性粒子粉末の磁気特性は、保磁
力Hcが高々240Oe程度、飽和磁化σsが高々
150emu/g程度であり、未だ十分なものとは言
い難いものである。
It has a high coercive force Hc and a large saturation magnetization σs,
Moreover, metal magnetic particles mainly composed of iron having an isotropic shape with uniform particle size are currently in high demand, but the isotropic shape obtained by the known method as described above is The magnetic properties of metal magnetic particles mainly composed of iron exhibiting a coercive force Hc of about 240 Oe and a saturation magnetization σs of about 240 Oe at most.
The amount is about 150 emu/g, which is still far from being sufficient.

また、公知方法による場合には、水溶液中から
生成したマグネタイト粒子粉末の粒度は不均斉で
あり、該マグネタイト粒子を加熱還元することに
より得られた鉄を主成分とする金属磁性粒子粉末
も当然不均斉なものとなる。
In addition, in the case of using a known method, the particle size of the magnetite particles produced from an aqueous solution is asymmetric, and the metal magnetic particles whose main component is iron obtained by thermally reducing the magnetite particles are naturally also asymmetric. It becomes symmetrical.

そこで、高い保磁力Hcと大きな飽和磁化σsと
を有し、しかも粒度が均斉である等方的形状を呈
した鉄を主成分とする金属磁性粒子粉末を得る為
の技術手段が強く要望されている。
Therefore, there is a strong need for a technical means to obtain iron-based magnetic metal particles having a high coercive force Hc and a large saturation magnetization σs, and exhibiting an isotropic shape with uniform particle size. There is.

〔問題点を解決する為の手段〕[Means for solving problems]

本発明者は、高い保磁力Hcと大きな飽和磁化
σsを有し、しかも、粒度が均斉である等方的形状
を呈した鉄を主成分とする金属磁性粒子粉末を得
るべく種々検討を重ねた結果本発明に到達したの
である。
The present inventor has conducted various studies in order to obtain iron-based magnetic metal particles having a high coercive force Hc and a large saturation magnetization σs, and exhibiting an isotropic shape with uniform particle size. As a result, the present invention was achieved.

即ち、本発明は、比表面積が150m2/g以上で
あるβ−FeOOH粒子を0.1mol/未満の濃度で
含む酸性懸濁液を100〜130℃の温度範囲で水熱処
理することにより、粒度の均斉な等方的形状を呈
したヘマタイト粒子を生成させ、該ヘマタイト粒
子を還元性ガス中で加熱還元して粒度の均斉な等
方的形状を呈した鉄を主成分とする金属磁性粒子
粉末とすることからなる等方的形状を呈した鉄を
主成分とする金属磁性粒子粉末の製造法である、 〔作用〕 先ず、本発明において最も重要な点は、比表面
積が150m2/g以上であるβ−FeOOH粒子を
0.1mol/未満の濃度で含む酸性懸濁液を100〜
130℃の温度範囲で水熱処理することにより、粒
度が均斉なヘマタイト粒子を生成させ、該ヘマタ
イト粒子を還元性ガス中で加熱還元した場合に
は、高い保磁力Hc、殊に、250Oe以上を有し、
且つ、大きな飽和磁化σs、殊に、170emu/g以
上を有する等方的形状を呈した鉄を主成分とする
金属磁性粒子粉末が得られるという事実である。
That is, the present invention reduces the particle size by hydrothermally treating an acidic suspension containing β-FeOOH particles with a specific surface area of 150 m 2 /g or more at a concentration of less than 0.1 mol/g in a temperature range of 100 to 130°C. Hematite particles with a uniform isotropic shape are generated, and the hematite particles are heated and reduced in a reducing gas to produce metal magnetic particle powder mainly composed of iron, which has an isotropic shape with a uniform particle size. [Operation] First, the most important point in the present invention is that the specific surface area is 150 m 2 /g or more. A certain β-FeOOH particle
Acidic suspension containing less than 0.1mol/100~
Hydrothermal treatment in a temperature range of 130°C produces hematite particles with uniform particle size, and when the hematite particles are heated and reduced in a reducing gas, they have a high coercive force Hc, especially 250 Oe or more. death,
Another fact is that it is possible to obtain iron-based metal magnetic particles having an isotropic shape and having a large saturation magnetization σs, in particular, 170 emu/g or more.

本発明においては、水溶液中から粒度が均斉で
あるヘマタイト粒子を生成させることができるこ
とに起因して、該ヘマタイト粒子を加熱還元して
得られる等方的形状を呈した鉄を主成分とする金
属磁性粒子粉末もまた、粒度が均斉なものであ
る。
In the present invention, since it is possible to generate hematite particles with uniform particle size from an aqueous solution, it is possible to produce iron-based metals with an isotropic shape obtained by heating and reducing the hematite particles. The magnetic particle powder is also uniform in particle size.

次に、本発明実施にあたつての諸条件について
述べる。
Next, various conditions for implementing the present invention will be described.

本発明におけるβ−FeOOH粒子粉末は、比表
面積が150m2/g以上であることが必要である。
150m2/g未満である場合には、粒度が均斉なヘ
マタイト粒子を得ることは困難であり、また、ヘ
マタイト粒子の生成反応に長時間を要する。150
m2/g以上のβ−FeOOH粒子粉末は、塩化第二
鉄水溶液を70〜90℃の温度範囲で加熱処理するこ
とにより加水分解する方法等により得ることがで
きる。
The β-FeOOH particles in the present invention need to have a specific surface area of 150 m 2 /g or more.
When it is less than 150 m 2 /g, it is difficult to obtain hematite particles with uniform particle size, and the reaction for producing hematite particles takes a long time. 150
β-FeOOH particles having a particle size of m 2 /g or more can be obtained by a method of hydrolyzing a ferric chloride aqueous solution by heating it in a temperature range of 70 to 90°C.

本発明におけるβ−FeOOHを含む懸濁液は、
酸性であることが必要であり、酸性でない場合、
100〜130℃の温度領域においてはβ−FeOOHが
安定して生成する為ヘマタイト粒子が生成しな
い。
The suspension containing β-FeOOH in the present invention is
It must be acidic, and if it is not acidic,
In the temperature range of 100 to 130°C, β-FeOOH is generated stably, so hematite particles are not generated.

本発明におけるβ−FeOOH粒子を含む酸性懸
濁液の濃度は0.1mol/未満である。0.1mol/
以上である場合にはヘマタイト粒子が生成しな
い。
The concentration of the acidic suspension containing β-FeOOH particles in the present invention is less than 0.1 mol/. 0.1mol/
If it is above, hematite particles will not be generated.

本発明における反応温度は、100〜130℃であ
る。100℃未満である場合には、β−FeOOHの
溶解が十分に進行しない為ヘマタイト粒子が生成
しない。130℃を越える場合にもヘマタイト粒子
は生成するが、高圧容器等特殊の装置を必要とす
る為、工業的、経済的ではない。
The reaction temperature in the present invention is 100 to 130°C. If the temperature is less than 100°C, the dissolution of β-FeOOH does not proceed sufficiently, so that hematite particles are not generated. Although hematite particles are generated when the temperature exceeds 130°C, it is not industrially or economically viable because special equipment such as a high-pressure container is required.

本発明における還元性ガス中における加熱還元
処理は常法により行うことができる。
The heating reduction treatment in a reducing gas in the present invention can be carried out by a conventional method.

また、出発原料であるヘマタイト粒子は、加熱
処理に先立つて通常行われるSi、Al、P化合物
等の焼結防止効果を有する物質によつてあらかじ
め被覆処理しておくことにより、より分散性の優
れた等方的形状を呈した鉄を主成分とする金属磁
性粒子粉末を得ることができる。
In addition, the hematite particles, which are the starting material, can be coated with a substance that has a sintering prevention effect, such as Si, Al, or P compounds, which is usually carried out prior to heat treatment, so that they have better dispersibility. It is possible to obtain metal magnetic particles having an isotropic shape and containing iron as a main component.

本発明における加熱還元後の鉄を主成分とする
金属磁性粒子粉末は周知の方法、例えば、トルエ
ン等の有機溶媒中に浸漬する方法及び還元後の鉄
を主成分とする磁性粒子粉末の雰囲気を一旦不活
性ガスに置換した後、不活性ガス中の酸素含有量
を徐々に増加させながら最終的に空気とすること
によつて徐酸化する方法等により空気中に取り出
すことができる。
In the present invention, the heat-reduced metal magnetic particle powder containing iron as the main component can be obtained by a well-known method, for example, by immersing it in an organic solvent such as toluene, or by immersing the reduced iron-based magnetic particle powder in an atmosphere. After the gas is once replaced with an inert gas, it can be taken out into the air by a method of gradual oxidation by gradually increasing the oxygen content in the inert gas and finally turning it into air.

〔実施例〕〔Example〕

次に、実施例並びに比較例により本発明を説明
する。
Next, the present invention will be explained with reference to Examples and Comparative Examples.

尚、以下の実施例における粒子の平均径は、電
子顕微鏡写真から測定した数値の平均値であり、
比表面積はBET法により測定した値である。
In addition, the average diameter of particles in the following examples is the average value of numerical values measured from electron micrographs,
The specific surface area is a value measured by the BET method.

実施例 1 Fe3+0.05mol/を含むFeCl3水溶液500mlを80
℃で30分間加熱して、黄褐色沈澱粒子を生成させ
た。この時の懸濁液のPHは1.3であつた。反応液
の一部を抜き取り、水洗、過、乾燥して得られ
た黄褐色粒子粉末の電子顕微鏡写真(×50000)
を図1に示す。この黄褐色粒子粉末は、X線回折
の結果β−FeOOHであり、比表面積は190m2
gであつた。
Example 1 500 ml of FeCl 3 aqueous solution containing 0.05 mol of Fe 3+ was added to 80
Heating at 0C for 30 minutes produced yellow-brown precipitated particles. The pH of the suspension at this time was 1.3. Electron micrograph (×50000) of yellowish brown particles obtained by extracting a portion of the reaction solution, washing with water, filtering, and drying.
is shown in Figure 1. As a result of X-ray diffraction, this yellowish brown particle powder was found to be β-FeOOH, and the specific surface area was 190 m 2 /
It was hot at g.

上記0.05mol/のβ−FeOOH粒子を含むPH
1.3の酸性懸濁液を密閉容器中に入れ、125℃で15
時間水熱処理して赤褐色沈澱を生成させた。赤褐
色沈澱を水洗、過、乾燥して得られた粒子粉末
は、図2に示すX線回折に示す通りヘマタイトで
あり、図3に示す電子顕微鏡写真(×20000)か
ら明らかな通り、平均粒子径が0.6μmの等方的形
状を呈した粒子であり、粒度が均斉で、且つ、
個々の粒子が独立した粒子であつた。
PH containing the above 0.05 mol/β-FeOOH particles
Place the acidic suspension of 1.3 in a closed container and heat it at 125℃ for 15 minutes.
Hydrothermal treatment for hours produced a reddish-brown precipitate. The particles obtained by washing the reddish brown precipitate with water, filtering, and drying are hematite as shown in the X-ray diffraction shown in Figure 2, and the average particle size is clear from the electron micrograph (x20000) shown in Figure 3. The particles have an isotropic shape of 0.6 μm, the particle size is uniform, and
Each particle was an independent particle.

上記ヘマタイト粒子粉末70gを1のレトルト
還元容器中に投入し、駆動回転させながらH2
スを毎分10の割合で通気し、還元温度420℃で
還元した。
70 g of the above-mentioned hematite particle powder was put into a retort reduction container (No. 1), and H 2 gas was passed through the container at a rate of 10 per minute while driving and rotating the container, and the container was reduced at a reduction temperature of 420°C.

還元して得られた等方的形状を呈した鉄を主成
分とする金属磁性粒子粉末は、空気中に取り出し
た時急激な酸化を起こさないように、一旦、トル
エン液中に浸漬して、これを蒸発させることによ
り、粒子表面に安定な酸化被膜を施した。
The metal magnetic particle powder, which is mainly composed of iron and exhibits an isotropic shape obtained by reduction, is once immersed in a toluene solution to prevent rapid oxidation when taken out into the air. By evaporating this, a stable oxide film was formed on the particle surface.

このようにして得られた鉄を主成分とする金属
磁性粒子粉末は、電子顕微鏡観察の結果、平均径
0.6μmの等方的形状を呈した粒子であり、粒度の
均斉なものであつた。また、磁気測定の結果、保
磁力Hcは、263Oe、飽和磁化σsは、187emu/g
であつた。
As a result of electron microscopy observation, the metal magnetic particle powder whose main component is iron obtained in this way has an average diameter of
The particles had an isotropic shape of 0.6 μm and were uniform in particle size. Also, as a result of magnetic measurement, the coercive force Hc is 263 Oe, and the saturation magnetization σs is 187 emu/g.
It was hot.

実施例 2 β−FeOOHを生成する際のFeCl3濃度を
0.01mol/とした以外は実施例1と同様にして
比表面積が240m2/gのβ−FeOOHを得た。
Example 2 FeCl 3 concentration when producing β-FeOOH
β-FeOOH with a specific surface area of 240 m 2 /g was obtained in the same manner as in Example 1 except that the amount was 0.01 mol/g.

上記0.01mol/のβ−FeOOH粒子を含むPH
1.4の酸性懸濁液を密閉容器中に入れ、105℃でで
12時間水熱処理して赤褐色沈澱を生成させた。赤
褐色沈澱を水洗、過、乾燥して得られた粒子粉
末は、X線回折の結果ヘマタイトであり、図4に
示す電子顕微鏡写真(×20000)から明らかな通
り、平均粒子径が0.15μmの等方的形状を呈した
粒子であり、粒子が均斉で、且つ、個々の粒子が
独立した粒子であつた。
PH containing the above 0.01mol/β-FeOOH particles
Put the acidic suspension of 1.4 into a closed container and heat it at 105℃.
Hydrothermal treatment for 12 hours produced a reddish brown precipitate. The particles obtained by washing the reddish-brown precipitate with water, filtering, and drying were found to be hematite as a result of X-ray diffraction, and as is clear from the electron micrograph (×20000) shown in Figure 4, the particles had an average particle diameter of 0.15 μm. The particles had a square shape, were symmetrical, and each particle was independent.

上記ヘマタイト粒子粉末70gを1のレトルト
還元容器中に投入し、駆動回転させながらH2
スを毎分10の割合で通気し、還元温度400℃で
還元した。
70 g of the above-mentioned hematite particles were put into a retort reduction container (No. 1), and H 2 gas was passed through the container at a rate of 10 per minute while the container was driven and rotated, thereby being reduced at a reduction temperature of 400°C.

還元して得られた等方的形状を呈した鉄を主成
分とする金属磁性粒子粉末は、空気中に取り出し
た時急激な酸化を起こさないように、一旦、トル
エン液中に浸漬して、これを蒸発させることによ
り、粒子表面に安定な酸化被膜を施した。
The metal magnetic particle powder, which is mainly composed of iron and exhibits an isotropic shape obtained by reduction, is once immersed in a toluene solution to prevent rapid oxidation when taken out into the air. By evaporating this, a stable oxide film was formed on the particle surface.

このようにして得られた鉄を主成分とする金属
磁性粒子粉末は、電子顕微鏡観察の結果、平均径
0.15μmの等方的形状を呈した粒子であり、粒度
の均斉なものであつた。また、磁気測定の結果、
保磁力Hcは、280Oe、飽和磁化σsは、
177.5emu/gであつた。
As a result of electron microscopy observation, the metal magnetic particle powder whose main component is iron obtained in this way has an average diameter of
The particles had an isotropic shape of 0.15 μm and were uniform in particle size. In addition, as a result of magnetic measurement,
Coercive force Hc is 280Oe, saturation magnetization σs is
It was 177.5 emu/g.

比較例 1 Fe2+1.5mol/を含む硫酸第一鉄水溶液20
を、あらかじめ、反応器中に準備された3.45−N
のNaOH水溶液20に加え(Fe2+に対し1.15当量
に該当する。)、PH12.8、温度90℃においてFe
(OH)2を含む第一鉄塩水溶液の生成を行つた。
Comparative example 1 Ferrous sulfate aqueous solution containing 1.5 mol/Fe 2+ 20
3.45-N prepared in advance in the reactor
In addition to NaOH aqueous solution 20 (corresponds to 1.15 equivalents to Fe 2+ ), Fe
An aqueous ferrous salt solution containing (OH) 2 was produced.

上記Fe(OH)2を含む第一鉄塩水溶液に温度90
℃において毎分100の空気を220分間通気してマ
グネタイト粒子粉末を生成した。
The above ferrous salt aqueous solution containing Fe(OH) 2 was heated to a temperature of 90°C.
Magnetite particle powder was produced by bubbling air at 100 °C per minute for 220 minutes.

得られたマグネタイト粒子粉末は、図5に示す
電子顕微鏡写真(×20000)から明らかな通り、
平均径0.2μmの等方的形状を呈した粒子であつ
た。
As is clear from the electron micrograph (×20000) shown in FIG. 5, the obtained magnetite particle powder has the following properties:
The particles had an isotropic shape with an average diameter of 0.2 μm.

上記マグネタイト粒子を実施例1と同様にして
加熱還元し、更に、粒子表面に安定な酸化被膜を
施した。
The above magnetite particles were heated and reduced in the same manner as in Example 1, and a stable oxide film was further formed on the particle surface.

このようにして得られた鉄を主成分とする金属
磁性粒子粉末は、電子顕微鏡観察の結果、平均径
0.2μmの等方的形状を有する粒子であり、粒度が
不均斉なものであつた。また、磁気測定の結果、
保磁力Hcは236Oe、飽和磁化σsは147emu/gで
あつた。
As a result of electron microscopy observation, the metal magnetic particle powder whose main component is iron obtained in this way has an average diameter of
The particles had an isotropic shape of 0.2 μm, and the particle size was asymmetric. In addition, as a result of magnetic measurement,
The coercive force Hc was 236 Oe, and the saturation magnetization σs was 147 emu/g.

〔発明の効果〕〔Effect of the invention〕

本発明における等方的形状を呈した鉄を主成分
とする金属磁性粒子粉末の製造法によれば、前出
実施例並びに比較例に示した通り、高い保磁力
Hcと大きな飽和磁化σsとを有し、しかも、粒度
が均斉である等方的形状を呈した鉄を主成分とす
る金属磁性粒子粉末であるので、静電複写用の磁
性トナー用材料粉末及び磁気記録用磁性粒子粉末
として好適なものである。
According to the method for producing iron-based metal magnetic particles exhibiting an isotropic shape according to the present invention, as shown in the above-mentioned Examples and Comparative Examples, a high coercive force is obtained.
It is a metal magnetic particle powder mainly composed of iron, which has Hc and a large saturation magnetization σs, and has an isotropic shape with a uniform particle size. It is suitable as a magnetic particle powder for magnetic recording.

【図面の簡単な説明】[Brief explanation of drawings]

図1、図3乃至図5は、いずれも電子顕微鏡写
真であり、図1は、実施例1でヘマタイトを生成
する際に用いたβ−FeOOH粒子粉末、図3及び
図4は、それぞれ実施例1及び実施例2で得られ
たヘマタイト粒子粉末、図5は比較例1で得られ
たマグネタイト粒子粉末である。図2は、実施例
1で得られたヘマタイト粒子粉末のX線回折図で
ある。
1, 3 to 5 are electron micrographs, and FIG. 1 is the β-FeOOH particle powder used in producing hematite in Example 1, and FIGS. 3 and 4 are respectively 1 and Example 2, and FIG. 5 shows the magnetite particles obtained in Comparative Example 1. FIG. 2 is an X-ray diffraction diagram of the hematite particles obtained in Example 1.

Claims (1)

【特許請求の範囲】[Claims] 1 比表面積が150m2/g以上であるβ−
FeOOH粒子を0.1mol/未満の濃度で含む酸性
懸濁液を100〜130℃の温度範囲で水熱処理するこ
とにより、粒度の均斉な等方的形状を呈したヘマ
タイト粒子を生成させ、該ヘマタイト粒子を還元
性ガス中で加熱還元して粒度の均斉な等方的形状
を呈した鉄を主成分とする金属磁性粒子とするこ
とを特徴とする等方的形状を呈した鉄を主成分と
する金属磁性粒子粉末の製造法。
1 β- with a specific surface area of 150 m 2 /g or more
By hydrothermally treating an acidic suspension containing FeOOH particles at a concentration of less than 0.1 mol/in at a temperature range of 100 to 130°C, hematite particles having an isotropic shape with uniform particle size are generated, and the hematite particles are is heated and reduced in a reducing gas to produce iron-based magnetic particles with an isotropic shape with uniform particle size. Method for producing metal magnetic particle powder.
JP61314169A 1986-12-25 1986-12-25 Production of metallic magnetic particle powder consisting essentially of iron of isotropic shape Granted JPS63162802A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP61314169A JPS63162802A (en) 1986-12-25 1986-12-25 Production of metallic magnetic particle powder consisting essentially of iron of isotropic shape

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP61314169A JPS63162802A (en) 1986-12-25 1986-12-25 Production of metallic magnetic particle powder consisting essentially of iron of isotropic shape

Publications (2)

Publication Number Publication Date
JPS63162802A JPS63162802A (en) 1988-07-06
JPH0575807B2 true JPH0575807B2 (en) 1993-10-21

Family

ID=18050076

Family Applications (1)

Application Number Title Priority Date Filing Date
JP61314169A Granted JPS63162802A (en) 1986-12-25 1986-12-25 Production of metallic magnetic particle powder consisting essentially of iron of isotropic shape

Country Status (1)

Country Link
JP (1) JPS63162802A (en)

Also Published As

Publication number Publication date
JPS63162802A (en) 1988-07-06

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