JPH0648521B2 - Method of manufacturing perpendicular magnetic recording medium - Google Patents
Method of manufacturing perpendicular magnetic recording mediumInfo
- Publication number
- JPH0648521B2 JPH0648521B2 JP16117485A JP16117485A JPH0648521B2 JP H0648521 B2 JPH0648521 B2 JP H0648521B2 JP 16117485 A JP16117485 A JP 16117485A JP 16117485 A JP16117485 A JP 16117485A JP H0648521 B2 JPH0648521 B2 JP H0648521B2
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- film
- recording medium
- substrate
- magnetic recording
- perpendicular magnetic
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- Manufacturing Of Magnetic Record Carriers (AREA)
Description
【発明の詳細な説明】 〔発明の技術分野〕 本発明は高分子フィルム基板上に磁性層が形成されてな
る垂直磁気記録媒体の製造方法に関するものである。TECHNICAL FIELD OF THE INVENTION The present invention relates to a method for producing a perpendicular magnetic recording medium in which a magnetic layer is formed on a polymer film substrate.
近年、磁気記録媒体の媒体面に垂直な方向の残留磁化を
利用して高密度な記録を行なう垂直磁気記録方式が注目
されている。2. Description of the Related Art In recent years, a perpendicular magnetic recording method has been attracting attention, which performs high density recording by utilizing residual magnetization in a direction perpendicular to the medium surface of a magnetic recording medium.
この垂直磁気記録のための垂直磁気記録媒体の代表的な
ものとしては、膜面に垂直な方向に磁化容易軸を有する
Co-Cr系合金層をスパッタリングにより形成して磁性層
とするものが知られている。A typical perpendicular magnetic recording medium for this perpendicular magnetic recording has an easy magnetization axis in a direction perpendicular to the film surface.
It is known that a Co—Cr alloy layer is formed by sputtering to form a magnetic layer.
次に垂直磁気記録媒体の１例を第２図により説明する
と、ポリイミド，ポリエチレンテレフタレート，芳香族
ポリアミド等の耐熱性高分子フィルタからなる基板(1)
と、この基板(1)の少くとも１方の表面に Co-Cr系合金
層などからなる磁性層(2)を形成し、この磁性層(2)上に
保護膜(3)及び潤滑層(4)を順に設けることにより垂直記
録媒体を完成している。この垂直記録媒体は磁気テープ
やフロッピーディスクへの使用が考えられている。Next, an example of the perpendicular magnetic recording medium will be described with reference to FIG. 2. A substrate (1) made of a heat-resistant polymer filter such as polyimide, polyethylene terephthalate, and aromatic polyamide.
And a magnetic layer (2) composed of a Co-Cr alloy layer or the like is formed on at least one surface of the substrate (1), and a protective film (3) and a lubricating layer ( The vertical recording medium is completed by providing 4) in order. This perpendicular recording medium is considered to be used for a magnetic tape or a floppy disk.
ところで磁性層としての Co-Cr合金層はアルゴン雰囲気
中で通常のコンベンショナル・スパッタリング法あるい
はマグネトロン・スパッタリング法で形成される。そし
て形成された Co-Cr系合金層はＣ軸に配向された柱状構
成であり、磁気特性は主として Co-Cr系合金層の組成に
よって決まる飽和磁化Msの他に膜面に垂直な磁気異方性
エネルギーKuが大きく、膜面に垂直方向の保磁力Ｈc⊥
が大きく高密度記録が可能となる条件を揃えている。By the way, the Co-Cr alloy layer as the magnetic layer is formed by a conventional conventional sputtering method or magnetron sputtering method in an argon atmosphere. The formed Co-Cr alloy layer has a columnar structure oriented along the C-axis, and the magnetic characteristics are magnetic anisotropy perpendicular to the film surface in addition to the saturation magnetization Ms determined mainly by the composition of the Co-Cr alloy layer. Coercive force Hc ⊥ in the direction perpendicular to the film surface
Is large and the conditions for high density recording are available.
しかるに上述した製造法によって所望の磁気特性を有す
る Co-Cr系合金層を形成する場合、基板である高分子フ
ィルムを真空中で80℃乃至 200℃に加熱する必要があ
る。このため、より耐熱性のポリイミドフィルムや芳香
族ポリアミドフィルムの方がポリエステルフィルムより
成膜上取り扱い容易でオリゴマーの表面析出などの問題
点もない。However, when the Co—Cr alloy layer having desired magnetic properties is formed by the above-mentioned manufacturing method, it is necessary to heat the polymer film as the substrate to 80 ° C. to 200 ° C. in vacuum. For this reason, a more heat-resistant polyimide film or aromatic polyamide film is easier to handle than a polyester film in terms of film formation, and there is no problem such as surface precipitation of oligomers.
しかし、ポリイミドフィルムや芳香族ポリアミドフィル
ムのように流延法で成膜し、加熱処理によって容媒を除
去する工程が必要なフィルムにおいては容媒が残留する
という問題がある。However, there is a problem that the solvent remains in a film such as a polyimide film or an aromatic polyamide film that requires a step of removing the solvent by a heat treatment to form a film.
有機容媒の具体例として、Ｎ，Ｎ′−ジメチルアセトア
ミド，ジメチルスルホキシド，ヘキサメチル，ホスホル
アミド，Ｎ−メチル−２−ピロリドン，テトラメチル尿
素，テトラメチレンスルホン，フェノール，モノハロゲ
ン化フェノール，モノハロゲン化クレゾール，クレゾー
ル，キシレン等が挙げられる。Specific examples of the organic solvent include N, N'-dimethylacetamide, dimethyl sulfoxide, hexamethyl, phosphoramide, N-methyl-2-pyrrolidone, tetramethylurea, tetramethylene sulfone, phenol, monohalogenated phenol, monohalogenated cresol. , Cresol, xylene and the like.
このため、耐熱性の優れたポリイミドフィルムや芳香族
ポリアミドフィルムを基板として真空中で加熱し、強磁
性合金層を形成する場合、これらフィルム中に含有され
た容媒が基板表面へにじみ出し、強磁性合金層の付着強
度が低下するという問題点がある。この付着強度の低下
は、磁気ヘッドによる同一トラック上での走行試験にお
いて、強磁性合金層の基板からのはがれやすさを伴なう
ため、垂直磁気記録媒体の寿命、信頼性という観点から
致命的な問題点である。Therefore, when a polyimide film or an aromatic polyamide film having excellent heat resistance is heated in a vacuum as a substrate to form a ferromagnetic alloy layer, the solvent contained in these films oozes out to the substrate surface, There is a problem that the adhesion strength of the magnetic alloy layer is reduced. This decrease in adhesion strength is fatal from the viewpoint of the life and reliability of the perpendicular magnetic recording medium, because it is easily peeled off from the substrate of the ferromagnetic alloy layer in a running test on the same track by a magnetic head. It is a problem.
上記のような問題点は、スパッタリングや蒸着の前工程
として行なわれる加熱脱ガス処理のような通常の基板の
表面処理では解決できない。The above-mentioned problems cannot be solved by ordinary surface treatment of the substrate such as thermal degassing treatment performed as a pre-process of sputtering or vapor deposition.
例えば特開昭 59-129956号公報には、光磁気記録媒体の
アクリル樹脂基板を10−４Torr以下の真空下で70〜85℃
で１時間以上熱処理することにより、アクリル樹脂基板
の表面の脱ガスを行ない、基板上に形成される磁性層の
磁気特性を向上させるということが記載されている。し
かしながら、光磁気記録媒体では、ヘッドと非接触で使
用されるため、垂直磁気記録媒体のようにヘッドと接触
状態で使用させるものとは異なり、基板と磁性層との付
着強度は問題とはならない。For example, in Japanese Patent Laid-Open No. 59-129956, an acrylic resin substrate of a magneto-optical recording medium is placed at 70 to 85 ° C. under a vacuum of 10 −4 Torr or less.
It is described that the surface of the acrylic resin substrate is degassed and the magnetic characteristics of the magnetic layer formed on the substrate are improved by heat treatment for 1 hour or more. However, since the magneto-optical recording medium is used in non-contact with the head, unlike the perpendicular magnetic recording medium which is used in contact with the head, the adhesion strength between the substrate and the magnetic layer does not matter. .
これに対して、ポリイミドフィルム，芳香族ポリアミド
フィルム等の膜中に残留している溶媒が主にＮ，Ｎ′−
ジメチルアセトアミド（沸点 165℃［760mmHg］63℃［1
2mmHg］）の場合、10−４Torrよりもよい真空下で 100
℃、１時間程度の脱ガス処理を行なってもフィルム全体
の残存溶媒量はほとんど変らない。そのため、強磁性合
金層の付着強度も改善されず、フィルム中の残存溶媒に
よると考えられている磁気ヘッド走行経過に伴なう基板
フィルムと磁性層との間の球状部分はくりの数も軽減さ
れない。この原因は、残存溶媒とポリマー分子が相互作
用していて溶媒がフィルムから蒸発しにくなっているた
めである。実際に上記溶媒の場合、大気中での熱天秤装
置評価結果では、 260℃以上でないと試料フィルムの重
量変化は観測されない。On the other hand, the solvent remaining in the film such as a polyimide film or an aromatic polyamide film is mainly N, N'-
Dimethylacetamide (boiling point 165 ° C [760mmHg] 63 ° C [1
2 mmHg]) 100 under vacuum better than 10 -4 Torr
Even if the degassing treatment is carried out at a temperature of about 1 hour, the amount of residual solvent in the whole film is hardly changed. Therefore, the adhesion strength of the ferromagnetic alloy layer is not improved, and the number of spherical peeling between the substrate film and the magnetic layer due to the running of the magnetic head, which is considered to be due to the solvent remaining in the film, is also reduced. Not done. This is because the residual solvent interacts with the polymer molecules and the solvent is less likely to evaporate from the film. In fact, in the case of the above-mentioned solvent, the weight change of the sample film is not observed unless the temperature is 260 ° C or higher in the evaluation result of the thermobalance in the atmosphere.
また、表面だけでなくフィルム全体の残存溶媒量の減少
は、上記磁気ヘッド走行による球状部分はくりに加え
て、強磁性合金層及び保護膜形成時の温度上昇に伴なう
残存溶媒のフィルム内部からフィルムと強磁性合金層と
の界面への熱拡散による付着強度の低下等から重要であ
る。Further, not only the surface but also the amount of residual solvent in the entire film decreases, in addition to the spherical part peeling due to the magnetic head running, the residual solvent inside the film due to the temperature rise during the formation of the ferromagnetic alloy layer and the protective film. Is important from the viewpoint of reduction in adhesion strength due to thermal diffusion to the interface between the film and the ferromagnetic alloy layer.
本発明は、上述の諸問題点に鑑みてなされたものであ
り、長寿命、かつ高信頼性の垂直磁気記録媒体を得る製
造方法を提供するものである。The present invention has been made in view of the above problems, and provides a method of manufacturing a perpendicular magnetic recording medium having a long life and high reliability.
本発明は、高分子フィルム基板中に残存する溶媒量を0.
7 重量％以下とするように基板を加熱する工程と、この
工程の後、基板上に膜面に垂直な方向に磁化容易軸を有
する磁性層を形成する工程とを有する垂直磁気記録媒体
の製造方法である。The present invention, the amount of solvent remaining in the polymer film substrate is 0.
Manufacture of a perpendicular magnetic recording medium having a step of heating the substrate so that the content is 7% by weight or less, and a step of forming a magnetic layer having an easy axis of magnetization on the substrate in a direction perpendicular to the film surface after this step. Is the way.
以下本発明を完成するに至った実験について説明する。The experiments that have completed the present invention will be described below.
即ち、まず残存溶媒量の異なるポリイミドフィルムの基
板上に強磁性合金層として Co-Cr膜をアルゴン雰囲気中
でスパッタリング法で5000Å形成し、 Co-Cr膜の基板へ
の付着強度を評価した。That is, first, a Co-Cr film was formed as a ferromagnetic alloy layer on a substrate of a polyimide film having a different amount of residual solvent in an argon atmosphere by a sputtering method to a thickness of 5000 liters, and the adhesion strength of the Co-Cr film to the substrate was evaluated.
このフィルム中の残存溶媒量の測定方法としては、ガス
クロマトグラフィ法、溶媒抽出法、熱天秤法等があるが
一番簡便である熱天秤法によって残存溶媒分の蒸発に伴
なう重量変化から求めた。The method for measuring the amount of residual solvent in this film includes a gas chromatography method, a solvent extraction method, a thermobalance method, etc., but the simplest thermobalance method is used to determine the weight change accompanying evaporation of the residual solvent content. It was
この場合、 Co-Cr膜の形成は条件を一定とし、かつポリ
イミドフィルムは厚さおよび表面性などの同一なものを
用い、残存溶媒だけを変化したものを使用した。この条
件により作製した垂直磁気記録媒体については、まず C
o-Cr膜とポリイミドフィルムとの間の付着強度を次のよ
うな方法で評価した。即ち、格子状に切り目をいれた C
o-Cr膜に付着力が６kg／cm2の接着テープを Co-Cr膜の
表面に均一に接着し、一定速度、一定方向へ引きはが
し、ポリイミドフィルム上に残存している Co-Cr膜の面
積量を求めることによって相当付着強度を評価した。In this case, the Co-Cr film was formed under the same conditions, and the polyimide film was the same in thickness and surface property, and the residual solvent was changed. For the perpendicular magnetic recording media manufactured under these conditions,
The adhesion strength between the o-Cr film and the polyimide film was evaluated by the following method. That is, C with a grid cut
Adhesive tape with an adhesive force of 6 kg / cm 2 on the o-Cr film was evenly adhered to the surface of the Co-Cr film and peeled off at a constant speed and in a constant direction to remove the remaining Co-Cr film on the polyimide film. The equivalent adhesion strength was evaluated by determining the area amount.
その結果、残存溶媒量 0.7wt％以下のポリイミドフィル
ムでは Co-Cr膜のはがれが起きなかったが、 1.0重量％
以上のポリイミドフィルムでは30乃至80％程度のはがれ
が生じた。この結果から Co-Cr膜の相対付着強度が残存
溶楳量 0.7重量％を越すと著しく低下することがわかっ
た。As a result, peeling of the Co-Cr film did not occur in the polyimide film with a residual solvent amount of 0.7 wt% or less, but 1.0 wt%
With the above polyimide film, peeling of about 30 to 80% occurred. From this result, it was found that the relative bond strength of the Co-Cr film was remarkably lowered when the residual melt content exceeded 0.7% by weight.
次に、 Co-Cr膜とポリイミドフィルムとの付着強度と関
連があると思われる耐久性寿命の変化を調べた。この評
価は Co-Cr膜上に Al2O3 保護膜を 200Å程度形成し、
更にフロロカーボンを潤滑層として塗布した垂直磁気記
録媒体を磁気ヘッドを用いて同一トラック上を走行さ
せ、寿命にいいたるまでの走行回数を測定することによ
って行なった。第１図ポリイミドフィルムの残存溶媒量
と走行回数の結果、得られた曲線(11)を示す。この測定
結果はサンプル数をそれぞれ10個とした時の平均値であ
る。この曲線(11)は付着強度試験とよく対応している。Next, the change in durability life which seems to be related to the adhesion strength between the Co-Cr film and the polyimide film was investigated. In this evaluation, an Al 2 O 3 protective film was formed on the Co-Cr film to about 200 Å,
Further, the perpendicular magnetic recording medium coated with fluorocarbon as a lubricating layer was run on the same track by using a magnetic head, and the number of runs until the end of its life was measured. FIG. 1 shows the curve (11) obtained as a result of the amount of remaining solvent of the polyimide film and the number of running times. This measurement result is an average value when the number of samples is 10, respectively. This curve (11) corresponds well with the bond strength test.
この場合、残存溶楳量の多いポリイミドフィルム上に形
成した Co-Cr膜の方が局部的なはがれが起き易いため
か、ドロップアウトの増加速度が非常に速くなるという
傾向にある。In this case, the rate of increase in dropout tends to be very fast, probably because the local peeling is more likely to occur in the Co-Cr film formed on the polyimide film having a large amount of residual melt.
また、フィルム基板の内部から Co-Cr膜との界面への溶
楳の熱拡散による付着強度低下の調査した。結果を第３
図に示す。これは保護膜形成時の温度上昇に伴なう溶媒
の熱拡散によるフィルムと Co-Cr膜の付着強度への影響
を調べる上で重要である。基板温度が高い方が媒体のカ
ール、保護膜の膜質等の観点から望ましい。第３図は
0.3重量％と 1.26 重量％の残存溶媒量のポリイミドフ
ィルムに Co-Cr膜を形成し、各温度である時間加熱した
のち相対付着強度低下率を示したものである。ここで、
相対付着強度の低下率とは、加熱処理する前の相対付着
強度を 100％とした場合の相対付着強度を示している。
残存溶媒量が 0.3重量％のものでは 200℃、２時間の加
熱処理後も相対付着強度に変化はみられない。しかしな
がら 1.26重量％のものでは、 150℃の温度では50分以
上、 175℃では10分以上、200℃では７分以上で相対付
着強度の著しい低下がおきる。このことは、フィルムと
Co-Cr膜との界面まで拡散してきた溶媒が薄い層を形成
し、付着強度をさらに下げるものと考えられる。We also investigated the decrease in adhesion strength due to thermal diffusion of the Ume from the inside of the film substrate to the interface with the Co-Cr film. The result is the third
Shown in the figure. This is important for investigating the influence on the adhesion strength between the film and the Co-Cr film due to the thermal diffusion of the solvent accompanying the temperature rise during the formation of the protective film. A higher substrate temperature is desirable from the viewpoint of curling of the medium, film quality of the protective film, and the like. Figure 3 shows
Co-Cr films are formed on polyimide films having residual solvent amounts of 0.3% by weight and 1.26% by weight, and the relative adhesion strength reduction rate is shown after heating at each temperature for a certain period of time. here,
The rate of decrease in relative adhesion strength refers to the relative adhesion strength when the relative adhesion strength before heat treatment is 100%.
When the residual solvent amount is 0.3% by weight, the relative adhesion strength does not change even after the heat treatment at 200 ° C. for 2 hours. However, in the case of 1.26% by weight, the relative bond strength significantly decreases at a temperature of 150 ° C for 50 minutes or longer, at 175 ° C for 10 minutes or longer, and at 200 ° C for 7 minutes or longer. This is a film
It is considered that the solvent that has diffused to the interface with the Co-Cr film forms a thin layer and further reduces the adhesion strength.
以上の結果から Co-Crなどの強磁性合金層をスパッタリ
ング法などで高分子フィルム基板上に形成して磁気媒体
を作成する場合、高分子フィルム基板中の残存溶媒量が
0.7重量％以下のものを用いることが必要であり、そう
することによって垂直磁気記録媒体の耐久性寿命が飛躍
的に改善される。From the above results, when forming a magnetic medium by forming a ferromagnetic alloy layer such as Co-Cr on a polymer film substrate by a sputtering method, etc., the residual solvent amount in the polymer film substrate is
It is necessary to use 0.7 wt% or less, and by doing so, the durability life of the perpendicular magnetic recording medium is dramatically improved.
また以上の理由により使用する高分子フィルム基板中の
残存溶媒量を 0.7重量％以下にしなければならない。も
し、最初から残存溶媒の少ないフィルムの入手が難しい
場合は、大気中または真空中で加熱前処理をして 0.7重
量％以下にしてから、強磁性合金層を形成しなければな
らない。For the above reasons, the amount of residual solvent in the polymer film substrate used must be 0.7% by weight or less. If it is difficult to obtain a film with little residual solvent from the beginning, the ferromagnetic alloy layer must be formed after heat pretreatment in air or vacuum to 0.7 wt% or less.
以下に高分子フィルム基板中の残存溶媒量を減少させる
加熱処理条件の例について説明する。加熱処理条件の決
定には、特に大気中処理の場合において、熱天秤装置に
よる溶媒蒸発に伴なう重量変化測定が有効である。当然
残存している溶媒の種類によって処理温度を変える必要
がある。そこで処理温度は熱天秤測定結果の重量変化が
始まる温度以上に設定し、処理時間に伴なって残存溶媒
量を調べ処理時間を決定するとよい。ただし、真空装置
内で行なう場合は温度は上記よりも当然低くてもよい。
例えばＮ，Ｎ′−ジメチルアセトアミドが主にポリイミ
ドフィルム中に残存している場合、熱天秤の測定結果に
よると毎分15℃の昇温速度で 260℃程度から重量変化が
はじまり、 360℃程度で終了する。この結果に基づいて
種々の条件の実験を行ない処理法を決定した。Hereinafter, an example of heat treatment conditions for reducing the amount of residual solvent in the polymer film substrate will be described. To determine the heat treatment conditions, particularly in the case of treatment in the atmosphere, measurement of weight change due to solvent evaporation by a thermobalance device is effective. Naturally, it is necessary to change the treatment temperature depending on the type of the remaining solvent. Therefore, it is advisable to set the treatment temperature to a temperature equal to or higher than the temperature at which the weight change of the thermobalance measurement result starts, and to examine the residual solvent amount along with the treatment time to determine the treatment time. However, the temperature may naturally be lower than the above when performing in a vacuum apparatus.
For example, when N, N'-dimethylacetamide mainly remains in the polyimide film, the measurement result of the thermobalance shows that the weight change starts from 260 ° C at a heating rate of 15 ° C / min, and at 360 ° C. finish. Based on these results, experiments were conducted under various conditions to determine the treatment method.
従って、ポリイミドフィルムを例にとれば、大気中では
260℃以上に加熱するとが好ましい。また真空度10−５
Torrでは 220℃以上に加熱することが好ましい。なお、
加熱温度の上限は、高分子フィルムの分解温度によって
制限される。一般的に高分子フィルム基板中の残存溶媒
量を減少させる加熱する処理は、大気中で行なうのが、
処理整備を容易に構成でき実用的である。Therefore, taking a polyimide film as an example,
It is preferable to heat to 260 ° C or higher. Vacuum degree 10-5
In Torr, it is preferable to heat to 220 ° C or higher. In addition,
The upper limit of the heating temperature is limited by the decomposition temperature of the polymer film. Generally, the heating treatment for reducing the amount of residual solvent in the polymer film substrate is performed in the atmosphere,
It is practical because the maintenance can be easily configured.
実施例１ 残存溶媒量が 1.3重量％、厚さ75μｍのポリイミドフィ
ルムを、大気中で320℃、１時間加熱処理を施した。こ
の結果、残存溶媒量は 0.3重量％であった。第２図に示
すように、このポリイミドフィルムを基体(1)として、
両面に磁性層(2)として Co-Cr合金層を直流マグネトロ
ンスパタリングにより厚さ 0.5μｍ、保護層(3)として
Al2O3 をスパッタリングにより厚さ 200Å、また潤滑層
(4)としてフロロカーボンを 200Å以下の厚さにスピン
塗布して垂直磁気記録媒体を作成した。Example 1 A polyimide film having a residual solvent amount of 1.3% by weight and a thickness of 75 μm was heat-treated at 320 ° C. for 1 hour in the air. As a result, the amount of residual solvent was 0.3% by weight. As shown in FIG. 2, this polyimide film is used as a substrate (1),
Co-Cr alloy layer as magnetic layer (2) on both sides by DC magnetron sputtering, 0.5μm thick, as protective layer (3)
Al 2 O 3 is sputtered to a thickness of 200Å, and a lubricating layer
As (4), fluorocarbon was spin-coated to a thickness of 200 Å or less to prepare a perpendicular magnetic recording medium.
この垂直磁気記録媒体は寿命試験を行なったところ、10
00万パス以上の寿命特性が得られた。This perpendicular magnetic recording medium was subjected to a life test and found to be 10
The life characteristics of more than, 000,000 passes were obtained.
実施例２ 残存溶媒量が 1.3重量％、厚さ75μｍのポリイミドフィ
ルムを、真空度10−５Torr、 250℃、30分間熱処理を施
した。この結果、残存溶媒量は、上述実施例と同様に
0.3重量％であった。以上上述の実施例と同様にして垂
直磁気記録媒体を作成した。この垂直磁気記録媒体は、
1000万パス以上の寿命特性が得られた。Example 2 A polyimide film having a residual solvent amount of 1.3% by weight and a thickness of 75 μm was heat-treated at 250 ° C. for 30 minutes at a vacuum degree of 10 −5 Torr. As a result, the amount of residual solvent was the same as in the above-mentioned example.
It was 0.3% by weight. A perpendicular magnetic recording medium was prepared in the same manner as in the above-mentioned embodiment. This perpendicular magnetic recording medium
The life characteristics of more than 10 million passes were obtained.
実施例３ 残存溶媒量が２重量％、厚さ50μｍ芳香族ポリアミドフ
ィルムを、大気中 300℃、20分間熱処理を施した。この
残存溶媒量は 0.5重量％であった。以下上述の実施例と
同様にして垂直磁気記録媒体を作成した。この垂直磁気
記録媒体も、1000万パス以上の寿命特性が得られた。Example 3 An aromatic polyamide film having a residual solvent amount of 2% by weight and a thickness of 50 μm was heat-treated in the air at 300 ° C. for 20 minutes. The residual solvent amount was 0.5% by weight. Thereafter, a perpendicular magnetic recording medium was prepared in the same manner as in the above-mentioned embodiment. This perpendicular magnetic recording medium also has a life characteristic of 10 million passes or more.
また実施例では強磁性合金層が Co-Cr膜単層の場合につ
いて述べたが、これに限定されるものではなく Co-Cr膜
下に Fe-Ni合金を基とするパーマロイ等の軟磁性層を裏
打ちした場合にも本発明が適用されるのは勿論である。
また、 Co-Cr合金のみでなく、Coを基とする他の強磁性
合金層などをスパッタリング或は蒸着法によって磁性層
を形成する場合にもそのまま適用できる。Although the ferromagnetic alloy layer is described as a single layer of Co-Cr film in the examples, the present invention is not limited to this, and a soft magnetic layer such as permalloy based on Fe-Ni alloy is formed under the Co-Cr film. Needless to say, the present invention is applied to the case where the lining is performed.
Further, not only the Co—Cr alloy but also other ferromagnetic alloy layers based on Co, etc. can be applied as they are when the magnetic layer is formed by the sputtering or vapor deposition method.
〔発明の効果〕 上述のように本発明によれば高分子フィルムの残存溶媒
量を 0.7重量％以下にすることにより磁性層の付着強度
を上げることにより高寿命、高信頼性の垂直磁気記録媒
体を提供することができる。[Advantages of the Invention] As described above, according to the present invention, the residual solvent amount of the polymer film is set to 0.7% by weight or less to increase the adhesion strength of the magnetic layer, thereby increasing the service life and reliability of the perpendicular magnetic recording medium. Can be provided.
第１図は本発明の垂直磁気記録媒体のフィルムの残存溶
媒量と走行回数の関係を示す図、第２図は垂直磁気記録
媒体の断面図、第３図は加熱処理による Co-Cr膜の相対
付着強度低下率を示す図である。 １……基体、２……磁性層 ３……保護膜、４……潤滑層FIG. 1 is a diagram showing the relationship between the amount of residual solvent in the film of the perpendicular magnetic recording medium of the present invention and the number of times of running, FIG. 2 is a sectional view of the perpendicular magnetic recording medium, and FIG. It is a figure which shows a relative adhesive strength reduction rate. 1 ... Substrate, 2 ... Magnetic layer 3 ... Protective film, 4 ... Lubrication layer
───────────────────────────────────────────────────── フロントページの続き (72)発明者 大内 義昭 神奈川県川崎市幸区堀川町72 株式会社東 芝堀川町工場内 (56)参考文献 特開 昭60−121532（ＪＰ，Ａ) ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yoshiaki Ouchi 72 Horikawa-cho, Sachi-ku, Kawasaki-shi, Kanagawa Higashi-shiba, Higashi Shiba Co., Ltd. (56) References JP-A-60-121532 (JP, A)
Claims (2)
る基板を加熱して前記基板中に残存する前記溶媒を0.7
重量％以下にする第１の工程と、この工程の後前記基板
上に膜面に垂直な方向に磁化容易軸を有する磁性層を形
成する第２の工程とを有することを特徴とする垂直磁気
記録媒体の製造方法。1. A substrate made of a polymer film containing a residual solvent is heated to remove 0.7% of the solvent remaining in the substrate.
Perpendicular magnetic field, which comprises a first step of making the content of the magnetic material less than or equal to wt% and a second step of forming a magnetic layer having an easy axis of magnetization in a direction perpendicular to the film surface on the substrate after this step. Recording medium manufacturing method.
でなり、且つ前記第１の工程は大気中で前記基板を260
℃以上に加熱する工程を含むことを特徴とする特許請求
の範囲第１項記載の垂直磁気記録媒体の製造方法。2. The polymer film is a polyimide film, and the first step is to coat the substrate in the atmosphere.
The method of manufacturing a perpendicular magnetic recording medium according to claim 1, further comprising a step of heating to a temperature of not less than ° C.
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16117485A JPH0648521B2 (en) | 1985-07-23 | 1985-07-23 | Method of manufacturing perpendicular magnetic recording medium |
| KR1019850008243A KR890004258B1 (en) | 1984-11-14 | 1985-11-05 | Magnetic recording carrier and its method |
| EP19850114473 EP0182287B1 (en) | 1984-11-14 | 1985-11-14 | Perpendicular magnetic recording medium and method for preparing the same |
| DE8585114473T DE3573852D1 (en) | 1984-11-14 | 1985-11-14 | Perpendicular magnetic recording medium and method for preparing the same |
| US07/245,945 US4923763A (en) | 1984-11-14 | 1988-09-19 | Perpendicular magnetic recording medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16117485A JPH0648521B2 (en) | 1985-07-23 | 1985-07-23 | Method of manufacturing perpendicular magnetic recording medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6222242A JPS6222242A (en) | 1987-01-30 |
| JPH0648521B2 true JPH0648521B2 (en) | 1994-06-22 |
Family
ID=15729990
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP16117485A Expired - Lifetime JPH0648521B2 (en) | 1984-11-14 | 1985-07-23 | Method of manufacturing perpendicular magnetic recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0648521B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0664735B2 (en) * | 1985-07-26 | 1994-08-22 | 赤井電機株式会社 | Method for manufacturing perpendicular magnetic recording medium having permalloy thin film soft magnetic layer |
| JP2616711B2 (en) * | 1994-09-14 | 1997-06-04 | 東レ株式会社 | Magnetic recording media |
-
1985
- 1985-07-23 JP JP16117485A patent/JPH0648521B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6222242A (en) | 1987-01-30 |
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