JPS5898844A - Manufacture of magnetic recording medium - Google Patents

Abstract

PURPOSE:To remarkably reduce aging change of curling, by subjecting a metallic thin film type magnetic recording medium formed on a PET (polyethylene terephthalate) base to 2-step heat treatment. CONSTITUTION:A thin film of ferromagnetic metal is formed on the surface of a PET base by vapor deposition or sputtering to obtain a magnetic recording medium 10. This medium 10 is moved from a feed reel 5 to a winding reel 6, and heated on cylndrical rollers heated electrically or by the like proper method at 90-150 deg.C within 10min. Then, it is heated in a hot air circulation type thermostat or the like at 40-80 deg.C for >=12hr.

Description

【発明の詳細な説明】 ２ＥＱ明はポリエチレンテレフタレ−１−（以下ｐＥＴ
と略称する）基板上に強出ヰ金属の薄膜を形成した磁気
記録媒体の製造法に関する。[Detailed description of the invention] 2EQ light is polyethylene terephthalate-1- (hereinafter pET
The present invention relates to a method for manufacturing a magnetic recording medium in which a thin film of a strong metal is formed on a substrate (abbreviated as .).

磁気記録媒体に蝶、非磁性基板上にγＦｅ２Ｏ３等の針
状結晶を有機バインダで接着したいわゆる塗布型の磁気
記録媒体が従来から一般Ｖ（、便用されているが、近年
、高密度記録１ヒが要望され、これに伴なって金属薄膜
型の磁気記録媒体の研究、開発が進んでいる。So-called coating-type magnetic recording media, in which needle-like crystals such as γFe2O3 are bonded to a non-magnetic substrate using an organic binder, have been commonly used in the past, but in recent years high-density recording 1 In response to this demand, research and development of metal thin film magnetic recording media is progressing.

塗布型テープにおいては、塗布、乾燥、硬（ヒ装のカー
ルは主に塗布液（有機バインダ）の調合によって解決さ
れているが、真空蒸尤・、スパンタリング等り手法でコ
バルト、ニッケル、鉄などの強磁は体薄脇をＰＥＴ承板
表板表面成させる」烏合、高エネルギの金属原子がＰＥ
Ｔ表面に衝突、旬看し冷却する３、この時、付着した金
属の熱膨張係数ＶＣ見合った分だけ収縮し、ＰＥＴ基板
と金属薄膜との間に寸法差が生じ、カール生成の主原因
となる。第１図（ａ）はフィルム状ＰＥＴ基板１表面に
金属薄膜２が形成された直後の状態を示し、金属薄膜２
は１だ高温のままで、ＰＥＴ基板１との間に＝ｊ法差は
ない。同図（ｂ）は金属薄膜２の温度が室温に１で低下
し、その熱膨張係数に相蟲した収縮が起こり、金属薄膜
２とＰＥＴ基板１との間に寸法差が生じた状態を示す。For coated tapes, the problem of coating, drying, and hardening (curling of heat resistant tapes) is mainly solved by mixing the coating liquid (organic binder), but it is possible to remove cobalt, nickel, and iron by methods such as vacuum vaporization and sputtering. Ferromagnetic materials such as ferromagnets form the thin side of the PET plate on the surface of the PET base plate.
It collides with the T surface and is cooled for a while 3. At this time, it contracts by an amount commensurate with the thermal expansion coefficient VC of the attached metal, creating a dimensional difference between the PET substrate and the metal thin film, which is the main cause of curl formation. Become. FIG. 1(a) shows the state immediately after the metal thin film 2 is formed on the surface of the film-like PET substrate 1.
remains at a high temperature of 1, and there is no =j difference between it and the PET substrate 1. The same figure (b) shows a state in which the temperature of the metal thin film 2 drops to room temperature at 1, a gradual contraction occurs in its coefficient of thermal expansion, and a dimensional difference occurs between the metal thin film 2 and the PET substrate 1. .

同図（Ｃ）は両者にり一法差か生じた結果、カールが生
成した状態を示す。FIG. 2C shows a state in which a curl is generated as a result of a slight difference between the two.

本発明は磁性金属Ｎ膜よりなる記録層を備えた磁気記録
媒体の走行性を改唇することを意図するものである。磁
気記録媒体の一つである磁気テープの走行特注けその構
成材不−１の物理的１機械的性質によフて左右されるが
、その他に磁気テープの平坦ｒｔが大きく影響する。す
なわち、磁気テープは表面の平坦なことが望丑しいが、
金属薄膜の形成時にこれを平坦にすることは工業的に困
難であり、丑だ、たとえ金属薄膜形成時に平坦にできて
も、ＰＥＴ基板の残留内部応力が緩和し、寸法が変（ヒ
することにより時間の経過と共にカールする。The present invention is intended to improve the running properties of a magnetic recording medium having a recording layer made of a magnetic metal N film. The running of a magnetic tape, which is one of the magnetic recording media, depends on the physical and mechanical properties of its constituent materials, and is greatly influenced by the flatness of the magnetic tape. In other words, it is desirable for magnetic tape to have a flat surface;
It is industrially difficult to make the metal thin film flat when forming it, and even if it can be made flat when forming the metal thin film, the residual internal stress of the PET substrate will be relaxed and the dimensions will change. It curls over time.

第２図（ａ）〜（ｃ）において３はフィルム状ＰＥＴ基
板、４は金属薄膜で、同図（ｂ）はカールのない正常な
状、＠金、同図（、）は負（逆）のカールをした状態ケ
、同図（ｃ）は正のカールをしだ状７嘘ヲそれぞれ示し
ている。In Fig. 2 (a) to (c), 3 is a film-like PET substrate, 4 is a metal thin film, Fig. 2 (b) is a normal state without curl, @gold, Fig. 2 (,) is a negative (reverse) Figure (c) shows the positive curls in the 7-fold state.

第２図（ａ）　、　（ｃ）　ＶＣ示したような平坦性の
欠除した磁気テープが表向の平坦な磁気テープに比べ走
イ１的ユが劣るのは当然であり、かつリールに巻き取る
とき巻き乱れの原因となる。It is natural that a magnetic tape lacking flatness as shown in Figures 2 (a) and (c) VC has inferior running speed compared to a magnetic tape with a flat surface, and it is also difficult to wind it on a reel. This will cause the winding to become disordered when taking it out.

ところで従来、金属薄膜型磁気を己録媒体の平坦［ヒ法
としては、金属薄膜形成後、／１１１熱された熱ロール
表向−１−にＱ、１〜６０秒間密着させながら走行させ
、高分子成形物基板を熱収縮させて、表面に１ヒ成した
金属薄膜との寸法差をゼロに近づけることにより平坦ｒ
ヒする方法がある。しかしこの方法において月：、熱処
理直装は、幅方向に対して部分的（たとえば中央部分の
み）　Ｖ（ｌは平坦叱が可能であるが、それμ外の部分
は平坦（しできない。すなわち、全幅方向の均一な平坦
［ヒは小可能である０１だ、たとλ−熱処理直後に平坦
であっても、高分子成形物基板の残留内部応力が時間と
共Ｖζ緩和され、・Ｊ−法が経時変（ヒし、金属薄膜と
高分Ｐ成形物基板との間にマＪ法差が生じ、結局カール
してぐる。By the way, in the past, metal thin film magnetism was applied to the flat surface of a self-recording medium. By heat-shrinking the molecular molded substrate and bringing the dimensional difference between it and the metal thin film formed on the surface close to zero, flatness can be achieved.
There is a way to do it. However, in this method, the heat-treated direct mounting can be partially flattened in the width direction (for example, only the center part), but the parts outside μ can be flattened (i.e., Even if the substrate is flat immediately after heat treatment, the residual internal stress of the polymer molded substrate will be relaxed by Vζ over time, and the Over time, there will be a difference in maJ between the metal thin film and the polymer molded substrate, which will eventually curl.

すなわち、カールの大きな経時変［ヒは避けられない。In other words, large changes in curl over time [hi] are unavoidable.

本宛明者らは、このような問題点を解決するため鋭意イ
υＦ究した結果、金属薄膜形成後、９０〜１５０℃で１
０分μ内加熱処理し、その鏝、４０〜８０℃で１２時間
以上加熱処理することにより全幅方向に均一に平坦であ
り、しかも、フィルム状基板の残留内部応力が除去され
るので、カールの経時変ｒヒの極めて少ないテープを得
ることか０丁能となった。なお、９０〜１５０’Ｃで１
０分以内の加熱処理の効果としては、ＰＥＴ基板を急激
に熱収縮させることにより、表面に形成した金属薄膜と
の寸法差をゼロに近づけることである。よって熱処理の
温度が低すぎる場合、ＰＥＴ基板が十分収縮しないで効
果がない場合がある。また逆に熱処理温度が高すぎる場
＠、ＰＥＴ基板は十分に収縮するけれど、機械的強度が
低下し、使用不Ｉｉ］′になる場合がある。またこれら
のことは処理温度だけではなく処理時間にも関係する。As a result of intensive research into υF in order to solve these problems, the present authors found that after forming a metal thin film,
By heating the trowel for 12 hours or more at 40-80°C, it becomes uniformly flat in the entire width direction, and the residual internal stress of the film-like substrate is removed, preventing curling. It was possible to obtain a tape with very little change in temperature over time. In addition, 1 at 90-150'C
The effect of the heat treatment for less than 0 minutes is that by rapidly thermally shrinking the PET substrate, the dimensional difference with the metal thin film formed on the surface approaches zero. Therefore, if the heat treatment temperature is too low, the PET substrate may not shrink sufficiently, resulting in no effect. On the other hand, if the heat treatment temperature is too high, the PET substrate will shrink sufficiently, but its mechanical strength will decrease and it may become unusable. Furthermore, these matters are related not only to the processing temperature but also to the processing time.

すなわち、使用する高分Ｐ成形物基板が、ガラス転移へ
６９℃、融売２６３℃　、熱収縮率１５０℃　、３０分
でＱ、１係以上、５チ以下である一般的ＰＥＴフィルム
の場合、適切な処理温度は９０〜１６０℃であり、適切
な処理時開け１０分間以内であった。９０ｔＪＪ下では
１０分以上熱処理しても効果的に収縮せず、１６０Ｃ１
以上では引張り強度等の機械的特注が劣ｒヒし実用−に
問題があった。また、９０〜１５０℃の熱処理温度であ
っても、その温度で１０分間以上処理し続けると、やは
りＰＥＴ基板の機械的強度が低下し実用的でない。That is, in the case where the high content P molded substrate used is a general PET film having a glass transition temperature of 69°C, a melting temperature of 263°C, a heat shrinkage rate of 150°C, and a Q of 1 or more and 5 or less in 30 minutes, The appropriate processing temperature was 90 to 160°C, and the opening time during proper processing was within 10 minutes. Under 90tJJ, it does not shrink effectively even after heat treatment for more than 10 minutes, and 160C1
In the above, mechanical customization such as tensile strength is inferior and there is a problem in practical use. Further, even if the heat treatment temperature is 90 to 150° C., if the treatment is continued at that temperature for more than 10 minutes, the mechanical strength of the PET substrate will still decrease, making it impractical.

次に具体的に、本究明の実施例として真空蒸着による金
属薄膜型磁気記録媒体を製造する場合について説明する
。Next, as an example of the present invention, a case will be specifically described in which a metal thin film type magnetic recording medium is manufactured by vacuum evaporation.

第３図は′＋発明の実施例において用いられる処理装置
を示し、５は供給ＩＪ　　７ペ６は巻き敗りリール、ア
は電気により加熱された円筒状ロール（直径１００ｍｍ
）、８け補助ロール、９は／リコン製のニップロールで
ある。面上に金属薄膜が形成されたフィルム状基板は供
給リール６を出てニップロール９ＶＣより適当な温度に
加熱された熱ロール７表面に密着され、続いて巻取りリ
ール６［連続的に巻き取られる。Figure 3 shows a processing device used in an embodiment of the invention, 5 is a supply IJ, 7 is a winding reel, 6 is a winding reel, and A is an electrically heated cylindrical roll (diameter 100 mm).
), 8 auxiliary rolls, and 9 are nip rolls made by /Recon. The film-like substrate on which the metal thin film is formed leaves the supply reel 6 and is brought into close contact with the surface of the heat roll 7 which has been heated to an appropriate temperature by the nip roll 9VC, and is then continuously wound onto the take-up reel 6 .

実施例 厚さ１０１１ｍ、幅５００喘のバランスタイプのＰＥＴ
フィルム（熱収縮率１５０℃　３０分で長手方向４％２
幅方向２％）を基板として、これに５×１０　ｔｏｒｒ
の酸素雰囲気中でＣｏ　、　ｉｉｉ　（Ｃｏ　：８０ｗ
ｔ％、　Ｎｉ　：　２０ｗｔ％）を蒸着し膜厚０．１７
１ｍの金属薄膜を形成したもの（以丁蒸着フィルムと略
称する）を１００℃あるいは１２０℃に加熱した前記円
筒状ロールにそれぞれ１ｏ秒間接触させたｔの後、種々
の温度に保った熱風循還式恒温槽中に適当な時間保育し
、熱処理した３、熱処理圀前記蒸着フィルム全１０　ｍ
ｍ　ｌ’ｌ〕のテープ状に裁断し、テープ作成直後の平
坦曲を調べた。第１表に、１００℃の円筒状ロールに接
触させた後、熱処理した場合の結果を示し、第２表に、
１２０℃の円筒状ロールに接触させた陵、熱処理した場
合の結果を示す。なお表中の処理温度は熱風循還式恒温
槽の温度であり、処理時間は熱風循還式恒温槽中に保存
した時間を示す。丑だ、評価法としては、正、逆カール
ＶＣかかわらずカール高さｈ〔第２図（ａ）　、　（Ｃ
）参照〕が１００７１ｍ　　以内の場合（使用可能）０
印、それ以上の場合（使用不可）Ｘ印とした０以下余白 第１表および第２衣から明らかなように、テープ作成直
後においてカールのない平坦なものを得るには処理＠度
４０℃〜８０℃で１２時時間−１−保持した陵テープ状
に裁断すればよい。なおここで、第１表、第２表に示し
た結果において、熱処理効果が処理温度と処理時間との
積に依存した関係になっていないのけ次のような理由に
よるものと考えられる。すなわち、ＰＥＴのガラス転移
機が前述のように６９℃であり、この温度附近でｆｉＰ
ＥＴが微妙な温度差により非常に異りだ熱的挙動全示し
、したがって上記転移点附近の温度では、熱処理効果が
単ｖｃ（温度）×（時間）によるものではなく、（温度
）ｘ×（時間）〔ここでＸ〉１〕によるもので、時間よ
り温度に強く依存するためである。Example: Balance type PET with a thickness of 1011 m and a width of 500 mm.
Film (heat shrinkage rate: 4% in longitudinal direction at 150°C for 30 minutes2)
2% in the width direction) as a substrate, and apply 5×10 torr to this.
Co, iii (Co: 80w
t%, Ni: 20wt%) to a film thickness of 0.17
A 1 m thick metal thin film (hereinafter referred to as an evaporated film) was brought into contact with the cylindrical roll heated to 100°C or 120°C for 10 seconds, after which hot air was circulated at various temperatures. 3. A total of 10 m of the above-mentioned vapor-deposited film was incubated in a thermostatic oven for an appropriate period of time and heat-treated.
ml'l] was cut into a tape shape, and the flat curve immediately after the tape was made was examined. Table 1 shows the results when heat treated after contacting with a 100°C cylindrical roll, and Table 2 shows:
The results are shown when the ribs were brought into contact with a cylindrical roll at 120°C and heat treated. Note that the processing temperature in the table is the temperature of the hot air circulation constant temperature bath, and the processing time indicates the time of storage in the hot air circulation constant temperature bath. However, as an evaluation method, the curl height h [Figure 2 (a), (C
) is within 10071m (available) 0
If it is more than that (cannot be used), the margin is 0 or less marked with an It may be held at 80° C. for 12 hours and then cut into tape shapes. Here, in the results shown in Tables 1 and 2, the following reason is considered to be the reason why the heat treatment effect does not depend on the product of treatment temperature and treatment time. That is, as mentioned above, the glass transition temperature of PET is 69°C, and fiP
ET exhibits very different thermal behavior due to subtle temperature differences; therefore, at temperatures near the above transition point, the heat treatment effect is not simply due to vc (temperature) x (time), but rather due to (temperature) x ( time) [where X>1], and this is because it depends more on temperature than on time.

さて第１表、第２表においてＯ印（１史用可能）となっ
た条件で処理した場合、全幅方向において一様に平坦で
あ、りた。１２０℃に加熱した円筒状ロールに１ｏ秒間
接触させた後、６０’Ｃの恒温槽に２４時間保持した蒸
着フィルム（試料Ａとする）と、１２０℃の円筒状ロー
ルに１０秒間接触させただけの蒸着フィルム（試料Ｂと
する）との幅方向における平坦度の均−ｌを第４図（ａ
）　、　（ｂ）示す。Now, when processed under the conditions marked O in Tables 1 and 2 (possible for one-time use), the surface was uniformly flat in the entire width direction. After contacting a cylindrical roll heated to 120°C for 10 seconds, a vapor-deposited film (referred to as sample A) that was kept in a constant temperature bath at 60'C for 24 hours was contacted with a cylindrical roll heated to 120°C for 10 seconds. The average flatness in the width direction of the vapor-deposited film (sample B) is shown in
), (b) Show.

なお、図の縦軸は１０園幅テープに裁断した時の０ カール高さくＩｌｍ）ｆ表わし、正カールｋ（＋）、逆
カールを（−）で示す。横軸は蒸着フィルムの幅方向を
表わし、中央部（両端から２５０聴の場所）を０とし、
それから両端に向かって１０ｃｍ離れた所を１０．２０
℃ｍ離れた所を２０として表わしである。The vertical axis of the figure represents the 0 curl height (Ilm) f when cut into a 10-width tape, and normal curl k (+) and reverse curl (-) are shown. The horizontal axis represents the width direction of the vapor-deposited film, with the center portion (250 degrees from both ends) being 0;
Then 10.20 at a distance of 10 cm towards both ends.
It is expressed as 20 degrees Celsius.

試＃）Ａ、Ｂとも中央部および中央部から１０ｃｍ離れ
た部分の１０嫡幅テープのカール高さを調べ、全幅方向
における平坦度の均−訃とした。Test #) For both A and B, the curl height of the 10-square width tape at the center and at a portion 10 cm away from the center was examined to determine the uniformity of flatness in the entire width direction.

第４図（ａ）　、　（ｂ）から明らかなように、試料Ａ
はＢに比べ全幅方向において一様に平坦であった。As is clear from Figures 4(a) and (b), sample A
was uniformly flat in the entire width direction compared to B.

また、試料Ａ、Ｈの中央部の１０聰幅テープのカール経
時変ｒヒを調べた。第５丙は両試料を２０℃、６０％Ｒ
Ｈ雰囲気中で保存した時のカール高さの経時変１ヒを示
す。第６図は両試利′ｆｆ：６ｏ℃に保持した熱風循還
式恒温槽中に保存した時のカール高さの経時液ｒヒを示
す。第６図、第６図とも縦軸はカール高さくμｍ）を表
わし、正カールｋ（＋）、逆カールを（−）で示す。横
軸は該環境下での保存日数（対数目盛ンを表わす。In addition, the curl of the 10-width tape at the center of Samples A and H was examined over time. For No. 5, both samples were heated at 20°C and 60% R.
Figure 1 shows the change in curl height over time when stored in an H atmosphere. Figure 6 shows the curl height of the liquid over time when it was stored in a hot air circulation constant temperature bath maintained at 6oC. In both FIGS. 6 and 6, the vertical axis represents the curl height (μm), with positive curl k (+) and reverse curl k (-). The horizontal axis represents the number of days of storage under the environment (logarithmic scale).

＠６図および第６図より明らかなように試料ＡけＢにト
ヒベ著しくカール経時変［ヒが低減されることがわが：
）た。なお、６０℃の恒温槽に２４時間保持した陵、１
２０℃の円筒状ロールに１０秒間接触させることにより
作成した前記と同様な１０醍幅テープのカール経時変（
ヒは試料Ｂと大差なかった０ 捷だ、１２０℃の円筒状ロールに１０秒間接触させた後
、１０ｍ＋ｎ幅に裁断し、その陵、６０℃で２４時間保
持したものは、試料Ａと同等あるいはそれμ上のカール
経時変］ヒの低減に効果があった。As is clear from Figures 6 and 6, there is a marked change in curl over time for samples A and B.
)Ta. In addition, the ribs kept in a constant temperature bath at 60℃ for 24 hours, 1
Curl change over time of a 10-width tape similar to the above, which was made by contacting it with a cylindrical roll at 20°C for 10 seconds (
Sample A was not significantly different from Sample B. The sample was placed in contact with a cylindrical roll at 120°C for 10 seconds, cut into 10m+n width, and held at 60°C for 24 hours. It was effective in reducing curl over time.

以」二のように不発明の方法により製造された磁気記録
媒体は、テープ作成直後幅方向全面に平坦であり、しか
もカール軽時変［ヒが著しく低減される。したがって、
不発明は金属薄膜型の磁気記録媒体の走行特注を改善し
、その防用状態を良好ならしめる上できわめて有用であ
る。The magnetic recording medium manufactured by the uninvented method as described above is flat across the entire width in the width direction immediately after the tape is produced, and the curl variation over time is significantly reduced. therefore,
The invention is extremely useful in improving the running customization of metal thin film type magnetic recording media and in improving its durability.

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

第１図（ａ）　、　（ｂ）　、　（Ｃ）　Ｕそれぞれ磁
気ｎＱ録媒体において生じるカールの主原因を説明する
ための斜視図、第２図（ａ）　、　（ｂ）　、　（Ｃ）
それぞれ磁気記録媒体のカールした状態を説明するだめ
のＷ面図、第３図は本発明の実砲例において用いられる
処理装置を示す図、第４図（ａ）　、　（ｂ）　、第６
図、および第６図はそれぞれ不発明の効果を説明するだ
めの図で、このうち、第４図（ａ）　、　（ｂ）は蒸着
フィルムの幅方向における平坦度の均一性を示す図、第
５図は蒸着フィルムを２０℃、６０％Ｒ１−（雰囲気中
に保存したときのカール高さの経時変１ヒを示す図、第
６図は同じく蒸着フィルムを６０℃雰囲気中に保存した
ときのカール高さの経時変（シラ示す図である。 １．３・・・・・・ＰＥＴ基板、２，４・−・・・金桐
薄膜、７・・・・・・円筒状ローノペ　８・・・・・・
補助ロール。 代理人の氏名　弁理士　中　尾　敏　男　ほか１名第１
図 第２図 第３図 第４図 （α］　　　　　試ｆ″ｌ−ハ Ｃｂ＋　　　　　　試料ル 第５図 第６図Fig. 1 (a), (b), (C) U is a perspective view for explaining the main cause of curl that occurs in magnetic nQ recording media, Fig. 2 (a), (b), (C)
FIG. 3 is a diagram showing a processing device used in an actual gun example of the present invention, FIGS. 4(a) and 6(b), and FIG.
4(a) and 6(b) are diagrams showing the uniformity of the flatness in the width direction of the deposited film, respectively. Figure 5 shows the change in curl height over time when the deposited film was stored at 20°C in a 60%R1- (atmosphere), and Figure 6 shows the change in curl height over time when the deposited film was stored in a 60°C atmosphere. Change in curl height over time (This is a diagram showing the outline. 1.3...PET substrate, 2,4...Kanatau thin film, 7...Cylindrical low-knope 8...・・・・・・
Auxiliary role. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Fig. 2 Fig. 3 Fig. 4 (α) Sample f''l-Cb+ Sample l Fig. 5 Fig. 6

Claims (1)

【特許請求の範囲】[Claims] ポリエチレンテレフタレートよりなる基板表面に真空蒸
着あるいはスパッタリング法により強磁性金属の薄膜を
形成した後、９０℃〜１５Ｑ℃　で１０分間以内加熱し
、さらにその後、４０℃〜８０℃で１２時間以上加熱処
理することを特徴とする磁気記録媒体の製造法。After forming a thin film of ferromagnetic metal on the surface of a substrate made of polyethylene terephthalate by vacuum evaporation or sputtering, heating at 90°C to 15Q°C for less than 10 minutes, and then heat treatment at 40°C to 80°C for 12 hours or more. A method for manufacturing a magnetic recording medium, characterized by: