JPS5831724B2 - Manufacturing method of magnetic powder for magnetic recording - Google Patents
Manufacturing method of magnetic powder for magnetic recordingInfo
- Publication number
- JPS5831724B2 JPS5831724B2 JP742317A JP231774A JPS5831724B2 JP S5831724 B2 JPS5831724 B2 JP S5831724B2 JP 742317 A JP742317 A JP 742317A JP 231774 A JP231774 A JP 231774A JP S5831724 B2 JPS5831724 B2 JP S5831724B2
- Authority
- JP
- Japan
- Prior art keywords
- powder
- polyvinyl alcohol
- magnetic
- goethite
- iron oxide
- 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
Links
Landscapes
- Compounds Of Iron (AREA)
- Paints Or Removers (AREA)
- Magnetic Record Carriers (AREA)
- Hard Magnetic Materials (AREA)
Description
【発明の詳細な説明】
本発明は、磁気記録用磁性酸化鉄粉末の製造法の改良に
係り、特に配向性の改善された磁気記録用磁性酸化鉄粉
末の製造法に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved method for producing magnetic iron oxide powder for magnetic recording, and more particularly to a method for producing magnetic iron oxide powder for magnetic recording with improved orientation.
従来、δ−Ｆｅ２０３粉などの磁気記録用磁性酸化鉄粉
末は、鉄塩とアルカリ溶液から生成したゲーサイト粉末
を口過、水洗して乾燥したのち、水素ガスなどの還元雰
囲気中で還元し、次いで空気などの酸化雰囲気中で酸化
処理を施こして製造されている。Conventionally, magnetic iron oxide powder for magnetic recording, such as δ-Fe203 powder, is produced by sifting goethite powder produced from iron salt and an alkaline solution, washing it with water, drying it, and then reducing it in a reducing atmosphere such as hydrogen gas. It is then manufactured by performing oxidation treatment in an oxidizing atmosphere such as air.
しかし、この方法では、前記還元酸化時の加熱処理によ
って、磁性酸化鉄粉末粒子間で焼結を起して、樹枝状や
団塊状となり磁性塗膜の形成時に磁性酸化鉄粉末を十分
に配向することができず、角型のよい磁気記録体を得る
ことが困難であった。However, in this method, the heat treatment during the reduction and oxidation causes sintering between the magnetic iron oxide powder particles, resulting in dendritic or nodular shapes, and the magnetic iron oxide powder is sufficiently oriented when forming the magnetic coating film. Therefore, it was difficult to obtain a magnetic recording body with a good square shape.
本発明者は、かかる欠点について検討した結果、針状の
ゲーサイト粉末をポリビニルアルコール水溶液中に混練
して粒子表面をポリビニルアルコールで被覆し、還元処
理および／または酸化処理時に加熱処理すると粉末粒子
間の焼結が防止されて磁性塗膜の形成時に良好な配向性
を有することを究明した。As a result of studying these drawbacks, the present inventor found that if acicular goethite powder is kneaded in an aqueous polyvinyl alcohol solution and the particle surface is coated with polyvinyl alcohol, and then heat-treated during reduction treatment and/or oxidation treatment, there will be a gap between the powder particles. It was found that the sintering of the magnetic coating film was prevented and good orientation was achieved during the formation of the magnetic coating film.
ポリビニルアルコールに代えて、水溶性の多価アルコー
ルを用いた場合では、分子量が小さいのでゲーサイト粉
末を十分に被覆せず、還元処理ないしは還元、酸化処理
時に加熱処理を行なうと容易に蒸発ないし分解して消失
してしまいポリビニルアルコールの場合のように炭化物
が粉末粒子表面に残存しない。When a water-soluble polyhydric alcohol is used instead of polyvinyl alcohol, the molecular weight is small, so it does not cover the goethite powder sufficiently, and it easily evaporates or decomposes when subjected to reduction treatment or heat treatment during reduction or oxidation treatment. As a result, carbide does not remain on the powder particle surface as in the case of polyvinyl alcohol.
ポリビニルアルコール水溶液はゲーサイト粉末と親和性
を有し、ゲーサイト粉末とともに混練すると、ゲーサイ
ト粉末が均一に分散して、その表面に、ポリビニルアル
コールの被覆を形成する。The polyvinyl alcohol aqueous solution has an affinity for goethite powder, and when kneaded together with the goethite powder, the goethite powder is uniformly dispersed and a polyvinyl alcohol coating is formed on the surface thereof.
このポリビニルアルコールの被膜は、前記還元酸化処理
時に加熱処理をすることによって炭化し、この炭化物が
粉末粒子表面に残存して粉末粒子間の焼結を良好に防止
する。This polyvinyl alcohol coating is carbonized by heat treatment during the reduction-oxidation treatment, and this carbide remains on the surface of the powder particles to effectively prevent sintering between the powder particles.
しかもこのように処理された磁性酸化鉄粉末は、有機バ
インダーとの親和性が強く、有機バインダーとの混練時
の分散性が改善され、有機バインダーとの結着性が増加
し耐摩耗性が向上する効果もある。Moreover, the magnetic iron oxide powder treated in this way has a strong affinity with organic binders, improving dispersibility when kneading with organic binders, increasing binding with organic binders, and improving wear resistance. It also has the effect of
この粉末粒子の焼結は、ゲーサイト粉末に対するポリビ
ニルアルコールの混合量が多い程よく防止されるか、ゲ
ーサイト粉末の還元および酸化反応を低下させることに
なるので、ゲーサイト粉末に対するポリビニルアルコー
ルの混合量は１０〜５０重量％範囲に選定するのが適当
である。This sintering of powder particles is better prevented as the amount of polyvinyl alcohol mixed with the goethite powder increases, or the reduction and oxidation reactions of the goethite powder are reduced, so the amount of polyvinyl alcohol mixed with the goethite powder is is appropriately selected in the range of 10 to 50% by weight.
またポリビニルアルコールの被覆はゲーサイト粉末粒子
にできるだけ薄く形成されることが望ましいので、１０
〜３０重量％のポリビニルアルコール水溶液を使用する
のが望ましい。In addition, it is desirable that the coating of polyvinyl alcohol be formed on the goethite powder particles as thinly as possible;
It is preferred to use a ˜30% by weight aqueous solution of polyvinyl alcohol.
次に本発明の実施例について説明する。Next, examples of the present invention will be described.
水分を約５０重量％含有するゲーサイト粉末的１ｏｏｙ
に２０重量％ポリビニルアルコール水溶液を約３１’を
加え充分に混練する。Goethite powder containing approximately 50% water by weight
About 31' of a 20% by weight aqueous polyvinyl alcohol solution was added to the mixture and thoroughly kneaded.
このものを走行しているエンドレスベルト上に約０．１
ｍ／ｍ厚に塗布、乾燥してゲーサイト粉末を含むポリビ
ニルアルコールの薄膜を形成する。Approximately 0.1 on the endless belt running this thing
It is applied to a thickness of m/m and dried to form a thin film of polyvinyl alcohol containing goethite powder.
しかる後、この薄膜を水素ガス雰囲気中３５０℃に加熱
し、続いて空気中で２００〜２５０℃で加熱し、磁性酸
化鉄粉末を得る。Thereafter, this thin film is heated to 350° C. in a hydrogen gas atmosphere, and then heated at 200 to 250° C. in air to obtain magnetic iron oxide powder.
実施例で得た磁性酸化鉄粉末および従来の方法で得た磁
性酸化鉄粉末を用いて磁気テープを作り、これの角型比
を測定した結果、実施例のものは０．８１、従来のもの
は０．７５である。Magnetic tapes were made using the magnetic iron oxide powder obtained in the example and the magnetic iron oxide powder obtained by the conventional method, and the squareness ratios of the tapes were measured. is 0.75.
Claims (1)
液とともに混練して、ゲーサイト粉末粒子表面をポリビ
ニルアルコールで被覆し、還元および／または酸化処理
時に加熱処理することによって粉末粒子表面に炭化物を
残存せしめたことを特徴とする磁気記録用磁性酸化鉄粉
末の製造法。1. Acicular goethite powder is kneaded with an aqueous polyvinyl alcohol solution, the surface of the goethite powder particles is coated with polyvinyl alcohol, and carbide is left on the surface of the powder particles by heat treatment during reduction and/or oxidation treatment. A method for producing magnetic iron oxide powder for magnetic recording, characterized by:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP742317A JPS5831724B2 (en) | 1973-12-20 | 1973-12-20 | Manufacturing method of magnetic powder for magnetic recording |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP742317A JPS5831724B2 (en) | 1973-12-20 | 1973-12-20 | Manufacturing method of magnetic powder for magnetic recording |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5092499A JPS5092499A (en) | 1975-07-23 |
| JPS5831724B2 true JPS5831724B2 (en) | 1983-07-08 |
Family
ID=11525941
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP742317A Expired JPS5831724B2 (en) | 1973-12-20 | 1973-12-20 | Manufacturing method of magnetic powder for magnetic recording |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5831724B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57342B2 (en) * | 1974-04-08 | 1982-01-06 | ||
| JP6162981B2 (en) * | 2013-03-01 | 2017-07-12 | 日本化学工業株式会社 | Method for producing lithium sulfide and method for producing inorganic solid electrolyte |
-
1973
- 1973-12-20 JP JP742317A patent/JPS5831724B2/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5092499A (en) | 1975-07-23 |
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