JPH044653B2 - - Google Patents
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- Publication number
- JPH044653B2 JPH044653B2 JP59079909A JP7990984A JPH044653B2 JP H044653 B2 JPH044653 B2 JP H044653B2 JP 59079909 A JP59079909 A JP 59079909A JP 7990984 A JP7990984 A JP 7990984A JP H044653 B2 JPH044653 B2 JP H044653B2
- Authority
- JP
- Japan
- Prior art keywords
- magnetic
- magnetic recording
- recording medium
- layer
- powder
- 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
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- Paints Or Removers (AREA)
- Magnetic Record Carriers (AREA)
Description
【発明の詳細な説明】
本発明は新規な垂直磁気記録媒体に関するもの
である。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel perpendicular magnetic recording medium.
従来、オーデイオ・ビデオテープ、フロツピー
デイスク、ハードデイスクなどの磁気記録媒体
は、第１図に示すように、ポリマーフイルムや金
属などの非磁化性支持体１上に磁性を有する鉄、
酸化クロム、酸化鉄あるいは酸化鉄の表面にコバ
ルトを被着させたものなどの微粉体（磁性粉）３
をバインダー４中に分散させたものをコーテイン
グにより磁気記録層２として形成したものが広く
用いられてきている。コーテイング法によるこの
磁気記録層においては針状磁性粉が基板に対し水
平方向に配列されている。 Conventionally, magnetic recording media such as audio/video tapes, floppy disks, hard disks, etc. have magnetic recording media such as magnetic iron, magnetic metal, etc.
Fine powder (magnetic powder) such as chromium oxide, iron oxide, or cobalt coated on the surface of iron oxide3
It has been widely used to form the magnetic recording layer 2 by coating a material obtained by dispersing the magnetic material in a binder 4. In this magnetic recording layer formed by the coating method, acicular magnetic powder is arranged horizontally with respect to the substrate.
近年、基板に対して垂直方向に磁化しやすい磁
気記録層を用いる垂直磁気記録媒体が注目されて
いる。この場合、第２図に示すように磁性層６と
しては、スパツターや蒸着により形成されたCo
−Cr系合金が一般的で直径0.05μｍ程度以下の金
属繊維束が基板１上に垂直に配列された柱状粒子
構造を有する。 In recent years, perpendicular magnetic recording media that use a magnetic recording layer that is easily magnetized in a direction perpendicular to a substrate have been attracting attention. In this case, as shown in FIG. 2, the magnetic layer 6 is a Co
-Cr alloy is common and has a columnar particle structure in which metal fiber bundles with a diameter of about 0.05 μm or less are vertically arranged on the substrate 1.
基板としては金属、ガラス、ポリマーなど、ま
たはそれらにパーマロイ（Ni−Fe系など）のよ
うな軟磁性層５を薄く被覆したものが用いられ
る。ここで軟磁性層は磁気ヘツドによる記録およ
び再生の感度を著しく増大する役割をはたしてい
る。従来のコーテイング法による水平磁気記録媒
体の記録容量が１インチ平方当り数100万ビツト
であるのに対し垂直磁気記録媒体は１〜数億ビツ
トの記録容量をもつと言われる。しかし、現在垂
直磁気記録媒体として用いられているCo−Cr系
合金はコーテイング法による水平磁気記録媒体に
比べ媒体の機械的強度が著しく低く、記録あるい
は再生時におけるヘツドとの接触により容易に損
傷をうけるという致命的欠陥があり実用化に至つ
てはいない。 The substrate used is metal, glass, polymer, or the like, or a material thinly coated with a soft magnetic layer 5 such as permalloy (Ni--Fe system, etc.). Here, the soft magnetic layer plays the role of significantly increasing the sensitivity of recording and reproduction by the magnetic head. While the recording capacity of a horizontal magnetic recording medium formed by a conventional coating method is several million bits per square inch, a perpendicular magnetic recording medium is said to have a recording capacity of one to several hundred million bits. However, the Co-Cr alloy currently used as perpendicular magnetic recording media has significantly lower mechanical strength than horizontal magnetic recording media using a coating method, and is easily damaged by contact with the head during recording or reproduction. However, it has a fatal flaw in that it cannot be put into practical use.
本発明は上記の欠点を解決すべくなされたもの
で大きな記録容量と高い信頼性の垂直磁気記録媒
体を提供するものである。原理的には、第３図に
示すように従来のコーテイング法水平磁気記録媒
体の形成に用いた磁性塗料を、非磁化性支持体１
上に軟磁性層５を形成した基板上にコーテイング
し、針状磁性粉３を基板の垂直方向に配向配列さ
せた磁気記録層２′を作ることにある。従来のコ
ーテイング法という技術がそのまま利用できるこ
とや磁性塗料（針状磁性粉３とバインダー４とを
主成分とする塗料）の配合設計により、機械的・
電気的に信頼性の高い垂直磁気記録媒体が提供で
きること、また非磁化性支持体と磁気記録媒体の
中間に、軟磁性層を設けることにより針状磁性粉
の垂直配向性が著しく向上するという特長があ
る。 The present invention has been made to solve the above-mentioned drawbacks and provides a perpendicular magnetic recording medium with a large recording capacity and high reliability. In principle, as shown in FIG.
The purpose is to form a magnetic recording layer 2' by coating a substrate on which a soft magnetic layer 5 is formed, and having acicular magnetic powder 3 aligned in a direction perpendicular to the substrate. Due to the fact that the conventional coating method can be used as is and the formulation design of the magnetic paint (a paint whose main components are acicular magnetic powder 3 and binder 4), mechanical and
The feature is that it can provide a perpendicular magnetic recording medium with high electrical reliability, and that the perpendicular orientation of the acicular magnetic powder is significantly improved by providing a soft magnetic layer between the non-magnetic support and the magnetic recording medium. There is.
従来、スパツター法などで形成した垂直磁気記
録媒体の記録、再生感度の向上のために軟磁性層
を設けることは前述したように公知であるが、コ
ーテイング法においてこれを設け針状磁性粉の垂
直配向性を高めたという例はなく、本発明におけ
る軟磁性層の導入はコーテイング法における新し
い磁気記録媒体の構成を提供するものである。 As mentioned above, it has been known to provide a soft magnetic layer in order to improve the recording and reproducing sensitivity of perpendicular magnetic recording media formed by the sputtering method. There is no example of improved orientation, and the introduction of a soft magnetic layer in the present invention provides a new magnetic recording medium configuration using a coating method.
本発明において非磁化性支持体１としては、一
般にアルミのような金属やガラスのような金属酸
化物の円板やポリエチレンテレフタレートやポリ
イミドのようなポリマーフイルムなどが用いられ
る。この非磁化性支持体表面に高透磁率性の軟磁
性層５として、一般にはNi−Fe系のパーマロイ
がスパツタリング、蒸着、電着などの方法により
0.5〜1μｍ前後の膜厚で被覆される。 In the present invention, as the non-magnetizable support 1, a disk of metal such as aluminum or a metal oxide such as glass, a polymer film such as polyethylene terephthalate or polyimide, etc. are generally used. A soft magnetic layer 5 with high magnetic permeability is formed on the surface of this non-magnetic support by generally using Ni-Fe based permalloy by sputtering, vapor deposition, electrodeposition, etc.
It is coated with a film thickness of around 0.5 to 1 μm.
この基板上に、通常の水平磁気記録媒体に用い
られると同様の針状磁性紛２とバインダー４をふ
くむ磁性塗料が塗布される。ただし、塗布ののち
溶剤が飛散したりバインダーが反応したりして塗
膜の流動性が減少もしくはなくなるまでの間に、
塗布面に対し垂直方向に磁場配向を施こすことに
より磁性塗膜中の針状磁性粉を垂直方向に配列さ
せる。この時、支持体と磁性塗膜の中間に軟磁性
層を有するため、磁束集中効果により著しい垂直
磁気異方性膜が形成される。磁性塗膜として、実
用的に十分な機械強度をもつ通常の磁性塗料を用
いているため、信頼性の高い磁気記録媒体が提供
できる。 A magnetic paint containing acicular magnetic powder 2 and a binder 4 similar to those used in ordinary horizontal magnetic recording media is applied onto this substrate. However, after application, before the fluidity of the coating film decreases or disappears due to solvent scattering or binder reaction,
By applying a magnetic field orientation perpendicular to the coating surface, the acicular magnetic powder in the magnetic coating film is aligned in the perpendicular direction. At this time, since a soft magnetic layer is provided between the support and the magnetic coating, a film with remarkable perpendicular magnetic anisotropy is formed due to the magnetic flux concentration effect. Since a normal magnetic paint having practically sufficient mechanical strength is used as the magnetic coating film, a highly reliable magnetic recording medium can be provided.
以下実施例により本発明を具体的に説明する。 The present invention will be specifically explained below using Examples.
実施例
Co被着γ−Fe2O3粉末（HC＝540Oe） 320ｇ
アルミナ粉末 10ｇ
エポキシ樹脂／フエノール樹脂／ポリピニルブ
チラール＝40／50／10（重量％） 270ｇ
酢酸セロソルブ／ブチルセロソルブ＝50／50
（重量％） 1600ｇ
の組成を有する磁性塗料をニーダとボールミルを
用いて常法により混練してえた。Example Co-adhered γ-Fe 2 O 3 powder (HC=540Oe) 320g Alumina powder 10g Epoxy resin/phenolic resin/Polypinyl butyral = 40/50/10 (wt%) 270g Cellosolve acetate/Butyl cellosolve = 50/50
(% by weight) A magnetic paint having a composition of 1600 g was kneaded by a conventional method using a kneader and a ball mill.
これを直径５インチのアルミニウム円板上に
Fe−Niをスパツター法により0.5μｍ被覆した基
板に回転塗布法により乾燥膜厚が1μｍとなるよ
うに塗布した。 Place this on an aluminum disk with a diameter of 5 inches.
A substrate coated with Fe-Ni to a thickness of 0.5 μm using a sputtering method was coated using a spin coating method so that the dry film thickness was 1 μm.
直ちに磁力線が基板の垂直方向に走る磁場内に
この円板を置き低速で回転しつつ垂直磁場配向を
行ない、塗膜を乾燥したのち熱硬化（200℃、２
時間）して磁気記録媒体をえた。 Immediately, this disc was placed in a magnetic field in which lines of magnetic force run perpendicularly to the substrate, and rotated at low speed to perform vertical magnetic field orientation. After drying the coating film, it was thermally cured (200℃, 2
time) and obtained a magnetic recording medium.
この磁気記録媒体の磁化曲線を膜面に垂直な方
向と膜面に水平な方向とについて測定し、垂直方
向での保磁力（Hc⊥）及び水平方向での保磁力
（Hc）を求め、水平方向での保磁力に対する垂
直方向での保磁力の値（Hc⊥／Hc）で垂直異
方性を評価した。 The magnetization curve of this magnetic recording medium is measured in the direction perpendicular to the film surface and the direction horizontal to the film surface, and the coercive force in the vertical direction (Hc⊥) and the coercive force in the horizontal direction (Hc) are determined. Perpendicular anisotropy was evaluated by the value of coercive force in the perpendicular direction (Hc⊥/Hc) with respect to the coercive force in the direction.
第１図のような通常の水平磁気記録媒体では、
磁性粉の種類にもよるが一般にはほぼ１に近く、
第２図の垂直磁気記録媒体では、磁性材料や軟磁
性材の種類や成膜条件などによつて異なるが一般
に２〜５であると言われているが、実施例による
ものはこの値が180ときわめて大きい。 In a normal horizontal magnetic recording medium as shown in Figure 1,
Although it depends on the type of magnetic powder, it is generally close to 1,
In the perpendicular magnetic recording medium shown in FIG. 2, it is generally said that the value is 2 to 5, although it varies depending on the type of magnetic material or soft magnetic material, film formation conditions, etc., but in the example according to the example, this value is 180 It's extremely large.
なお、本実施例において基板に軟磁性層を施こ
さないことを除いては実施例と同一条件でえた磁
気記録媒体においては約２であつた。また、磁性
層の機械的な強度は磁気記録媒体を20ｍ／secの
速度で回転させた上にアルミナ球（曲率30mm）を
10ｇの荷重で接触させたときに磁性層が破壊され
るまでの時間で評価した。本実施例によるものは
ほぼ50秒であるのに対し、Co−Crスパツター膜
はほぼ２秒であつた。 In this example, the magnetic recording medium obtained under the same conditions as in the example except that a soft magnetic layer was not formed on the substrate had a value of about 2. In addition, the mechanical strength of the magnetic layer was determined by rotating the magnetic recording medium at a speed of 20 m/sec and then inserting an alumina sphere (curvature of 30 mm) into the magnetic recording medium.
The evaluation was based on the time until the magnetic layer was destroyed when brought into contact with a load of 10 g. The time required for the Co--Cr sputtered film was approximately 2 seconds, while the time required for the Co--Cr sputter film was approximately 50 seconds.
第１図は従来のコーテイング型水平磁気記録媒
体の、第２図は垂直磁気記録媒体の、第３図は本
発明によるコーテイング型垂直磁気記録媒体の断
面図である。
図において、１は非磁性支持体、２はコーテイ
ングによる水平配向の磁気記録層、２′はコーテ
イングによる垂直配向の磁気記録層、３は磁性
粉、４はバインダー、５は軟磁性層、６はスパツ
ター法による垂直磁気記録層である。
FIG. 1 is a cross-sectional view of a conventional coated horizontal magnetic recording medium, FIG. 2 is a cross-sectional view of a perpendicular magnetic recording medium, and FIG. 3 is a cross-sectional view of a coated perpendicular magnetic recording medium according to the present invention. In the figure, 1 is a nonmagnetic support, 2 is a horizontally oriented magnetic recording layer by coating, 2' is a vertically oriented magnetic recording layer by coating, 3 is magnetic powder, 4 is a binder, 5 is a soft magnetic layer, and 6 is a magnetic recording layer with vertical orientation. This is a perpendicular magnetic recording layer made by sputtering.
Claims (1)
ー中に分散した磁気記録層が形成された磁気記録
媒体において、非磁化性支持体と磁気記録層の中
間に軟磁性層を設け、さらに針状磁性粉を磁気記
録層の垂直方向に磁場配向させたことを特徴とす
る垂直磁気記録媒体。1. In a magnetic recording medium in which a magnetic recording layer in which acicular magnetic powder is dispersed in a binder is formed on a non-magnetizable support, a soft magnetic layer is provided between the non-magnetizable support and the magnetic recording layer, and A perpendicular magnetic recording medium characterized in that acicular magnetic powder is oriented in a magnetic field in a direction perpendicular to a magnetic recording layer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7990984A JPS60224118A (en) | 1984-04-20 | 1984-04-20 | Magnetic recording medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7990984A JPS60224118A (en) | 1984-04-20 | 1984-04-20 | Magnetic recording medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60224118A JPS60224118A (en) | 1985-11-08 |
| JPH044653B2 true JPH044653B2 (en) | 1992-01-29 |
Family
ID=13703408
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7990984A Granted JPS60224118A (en) | 1984-04-20 | 1984-04-20 | Magnetic recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60224118A (en) |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS548410U (en) * | 1977-06-20 | 1979-01-20 | ||
| JPS54138607U (en) * | 1978-03-20 | 1979-09-26 |
-
1984
- 1984-04-20 JP JP7990984A patent/JPS60224118A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60224118A (en) | 1985-11-08 |
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