JP2794580B2 - Manufacturing method of magnetic recording media - Google Patents
Manufacturing method of magnetic recording mediaInfo
- Publication number
- JP2794580B2 JP2794580B2 JP26825688A JP26825688A JP2794580B2 JP 2794580 B2 JP2794580 B2 JP 2794580B2 JP 26825688 A JP26825688 A JP 26825688A JP 26825688 A JP26825688 A JP 26825688A JP 2794580 B2 JP2794580 B2 JP 2794580B2
- Authority
- JP
- Japan
- Prior art keywords
- thin film
- magnetic
- magnetic recording
- lubricant
- film
- 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 - Fee Related
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05D1/00—Processes for applying liquids or other fluent materials
- B05D1/18—Processes for applying liquids or other fluent materials performed by dipping
- B05D1/185—Processes for applying liquids or other fluent materials performed by dipping applying monomolecular layers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y40/00—Manufacture or treatment of nanostructures
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、非磁性支持体上に磁性薄膜を形成してな
る、薄膜型の磁気記録媒体の製法に関する。Description: TECHNICAL FIELD The present invention relates to a method for producing a thin-film type magnetic recording medium in which a magnetic thin film is formed on a non-magnetic support.
本発明は、非磁性支持体上に磁性薄膜を形成してな
る、薄膜型の磁気記録媒体において、磁性薄膜表面に潤
滑剤の有機溶媒溶液を塗布した直後に、５℃以上25℃以
下の空気を送風してこの温度範囲内で潤滑剤溶液中の溶
媒を蒸発させ、トップコート層を磁性薄膜表面に形成す
ることにより、磁気記録媒体の走行性能並びに耐久性の
改善を図ろうとするものである。The present invention relates to a thin-film magnetic recording medium comprising a magnetic thin film formed on a non-magnetic support, and an air having a temperature of 5 ° C. or more and 25 ° C. or less immediately after the organic solvent solution of the lubricant is applied to the magnetic thin film surface. To evaporate the solvent in the lubricant solution within this temperature range and form a top coat layer on the surface of the magnetic thin film, thereby improving the running performance and durability of the magnetic recording medium. .
従来、磁気記録媒体としては、非磁性支持体上に磁性
粉末および添加剤を分散させた高分子バインダ溶液を塗
布し、磁場配向した後に乾燥して作成される塗布型の磁
気記録媒体が広く実用に供されている。Conventionally, as a magnetic recording medium, a coating type magnetic recording medium that is prepared by applying a polymer binder solution in which a magnetic powder and additives are dispersed on a non-magnetic support, orienting it in a magnetic field, and then drying it is widely used. Has been offered to.
磁性粉末としては、フェリ磁性系に属するγ−Fe
2O3、Fe3o4等の酸化鉄およびCoを含有するこれら酸化
鉄、あるいはBaO・6Fe2O3があり、またフェロ磁性系に
属するFe、Coを主成分とする金属粉末や、CrO2等が代表
的な材料としてあげられる。これらの材料をサブミクロ
ンの大きさの針状、板状、粒状の粒子形状に作成し、使
用される。また前記添加剤としては、Cr2O3、SiO2等の
研磨剤や各種潤滑剤、あるいは安定剤等があげられ、さ
らに前記高分子バインダとしては、塩ビ−酢ビ共重合体
樹脂、ポリウレタン樹脂、ポリエステル樹脂等が一般的
に使用されている。As magnetic powder, γ-Fe belonging to the ferrimagnetic system
2 O 3 , these iron oxides containing iron oxide and Co such as Fe 3 o 4 or BaO.6Fe 2 O 3 and metal powder mainly composed of Fe, Co belonging to ferromagnetic system, CrO 2 is a typical material. These materials are prepared and used in the form of needles, plates, or particles having a submicron size. Examples of the additive include abrasives such as Cr 2 O 3 and SiO 2 , various lubricants, and stabilizers. Further, examples of the polymer binder include a polyvinyl chloride-vinyl acetate copolymer resin and a polyurethane resin. , Polyester resin and the like are generally used.
このような塗布型の磁気記録媒体に対し、近年高まる
高密度磁気記録の要求に応えるものとして、非磁性支持
体上に磁性材料そのものを薄膜の型で直接被着した、い
わゆる薄膜型の磁気記録媒体が注目を集めている。すな
わち、磁性材料として、Co−Ni合金等のフェロ磁性系材
料や、Fe3O4、Co含有Fe3O4等のフェリ磁性系材料を、真
空蒸着、イオンプレーティング、スパッタリング等の真
空薄膜成型技術やメッキ法により、ポリエステルフィル
ム、ポリイミドフィルムあるいはアルミ基板等の非磁性
支持体上に形成した磁気記録媒体である。In response to the demand for high-density magnetic recording, which has been increasing in recent years, for such a coating type magnetic recording medium, a so-called thin film type magnetic recording in which a magnetic material itself is directly applied in a thin film type on a non-magnetic support. The media is getting attention. That is, as a magnetic material, and ferromagnetic material such Co-Ni alloy, Fe 3 O 4, a ferrimagnetic material such as Co-containing Fe 3 O 4, vacuum deposition, ion plating, vacuum film molding such as sputtering A magnetic recording medium formed on a non-magnetic support such as a polyester film, a polyimide film or an aluminum substrate by a technique or a plating method.
この薄膜型の磁気記録媒体は、製造条件の選択によ
り、抗磁力（Hc）や角型比（Rs）を大きくできるばかり
でなく、磁性薄膜中に高分子バインダや添加剤を含有し
ないので、飽和磁束密度（Bm）が大きく、このため磁性
薄膜の厚みを極めて薄くすることが可能である。しかも
塗布型の磁気記録媒体と比較して、磁性薄膜表面は非常
に平滑であり、磁気ヘッドのトラック面との密着性に優
れる。This thin film type magnetic recording medium can not only increase the coercive force (Hc) and squareness ratio (Rs) by selecting the manufacturing conditions, but also does not contain a polymer binder or additive in the magnetic thin film, so it is saturated. The magnetic flux density (Bm) is large, so that the thickness of the magnetic thin film can be made extremely thin. In addition, the surface of the magnetic thin film is very smooth and has excellent adhesion to the track surface of the magnetic head, as compared with a coating type magnetic recording medium.
これらの特徴のため、薄膜型の磁気記録媒体は、反磁
場による記録減磁や磁気ヘッドのトラック面とのスペイ
シングロスが小さく、短波長領域の電磁変換特性に優
れ、高密度磁気記録の要求に充分対応しうる性能をも
つ。Due to these characteristics, thin-film magnetic recording media have low recording demagnetization due to a demagnetizing field and small spacing loss with the track surface of the magnetic head, have excellent electromagnetic conversion characteristics in the short wavelength region, and have high demands for high-density magnetic recording. With sufficient performance to meet
しかしながら、薄膜型の磁気記録媒体においては、磁
性薄膜中に潤滑剤や研磨剤を含有させることが困難であ
り、又磁性薄膜の表面性が極めて良いために、磁気ヘッ
ドのトラック面や磁気ドラム等と凝着現象をおこし易
く、いわゆるスティックスリップやはりつき等実走行上
のトラブルが無視できず、耐久性や走行性等の信頼性に
欠けるきらいがあった。However, in a thin-film type magnetic recording medium, it is difficult to include a lubricant or an abrasive in the magnetic thin film, and the surface properties of the magnetic thin film are extremely good. In addition, it is easy to cause adhesion phenomenon, so that troubles in actual running such as stick-slip can not be ignored, and there is a tendency that reliability such as durability and running performance is lacking.
そこで従来より、薄膜型の磁気記録媒体においては、
磁性薄膜表面に例えばフッ素化合物系の潤滑剤の有機溶
媒溶液を塗布した後、これをドライチャンバ内で熱風乾
燥してトップコート層を設けることにより、前記耐久性
や走行性の改善を試みることが行われてきた。Therefore, conventionally, in a thin film type magnetic recording medium,
After applying an organic solvent solution of, for example, a fluorine compound-based lubricant to the surface of the magnetic thin film, and drying it with hot air in a dry chamber to provide a top coat layer, it is possible to try to improve the durability and running property. Has been done.
しかしながら、前記技術による薄膜型の磁気記録媒体
は、必ずしも満足すべき耐久性や走行性を安定に示すに
は至っていない。当然のことながら、潤滑剤の種類によ
っても改善の効果に差があり、そのため少しでも優秀な
材料を求めて分子構造の異なる潤滑剤が多種合成され、
実用試験に供されており、この方法による走行性、耐久
性の向上も着実な成果が得られつつある。However, the thin-film type magnetic recording medium according to the above-mentioned technology has not yet always exhibited satisfactory durability and running stability. Naturally, there is a difference in the effect of the improvement depending on the type of lubricant, and for this reason, various types of lubricants with different molecular structures are synthesized in search of even better materials.
It has been subjected to practical tests, and steady improvements have been achieved in running performance and durability by this method.
一方、本発明者らは、同じ例えばフッ素化合物系潤滑
剤であっても、磁性薄膜表面への塗布後の乾燥条件の違
いにより、薄膜型の磁気記録媒体の耐久性、走行性が少
なからず変化することを見出し、本発明を完成するに至
った。従って、本発明の課題は、薄膜型の磁気記録媒体
の磁性記録体の磁性薄膜表面に、例えばフッ素化合物系
等の潤滑剤の有機溶媒溶液を塗布・乾燥してトップコー
ト層を設けるにあたり、薄膜型の磁気記録媒体の耐久
性、走行性を最大限に発揮する乾燥条件を提供すること
である。On the other hand, the present inventors have found that even with the same, for example, fluorine compound-based lubricant, the durability and running properties of the thin-film type magnetic recording medium vary considerably due to differences in drying conditions after being applied to the surface of the magnetic thin film. And completed the present invention. Accordingly, an object of the present invention is to provide a top coat layer by applying and drying an organic solvent solution of a lubricant such as a fluorine compound on the surface of a magnetic thin film of a magnetic recording medium of a thin film type magnetic recording medium. An object of the present invention is to provide drying conditions that maximize the durability and running properties of a magnetic recording medium of the type.
前述した課題を解決するため、本発明による磁気記録
媒体の製法は、薄膜型の磁気記録媒体の磁性薄表面に、
例えばフッ素化合物系の潤滑剤のトップコート層を設け
るにあたり、前記フッ素化合物系潤滑剤の有機溶媒溶液
を磁性薄膜表面に塗布した直後に、５℃〜25℃の温度範
囲の空気を送風することにより、この温度範囲内で有機
溶剤を蒸発させ、乾燥することを特徴とするものであ
る。In order to solve the above-mentioned problems, a method for manufacturing a magnetic recording medium according to the present invention includes:
For example, upon providing a top coat layer of a fluorine compound-based lubricant, immediately after applying the organic solvent solution of the fluorine compound-based lubricant to the surface of the magnetic thin film, by blowing air in a temperature range of 5 ° C to 25 ° C. The organic solvent is evaporated and dried within this temperature range.
本発明に用いられる潤滑剤としては、例えば特開昭62
−161744号公報に記載されている一連のカルボン酸パー
フルオロアルキルエステル誘導体等があり、これを有機
溶媒に溶解した溶液を磁性薄膜表面に塗布、もしくはこ
の溶液中に浸漬して用いられる。磁性薄膜表面への潤滑
剤の塗布量は、潤滑剤の分子量にもよるが、磁性薄膜表
面一平方メートルあたり、１〜数mgであり、要は潤滑剤
が単分子吸着膜を形成するに相当する量を塗布すればよ
い。Lubricants used in the present invention include, for example,
There is a series of perfluoroalkyl ester derivatives of carboxylic acid described in JP-A-161744, and a solution obtained by dissolving them in an organic solvent is applied to the surface of the magnetic thin film or used by dipping in the solution. The amount of the lubricant applied to the surface of the magnetic thin film depends on the molecular weight of the lubricant, but is 1 to several mg per square meter of the surface of the magnetic thin film. In other words, the lubricant is equivalent to forming a monomolecular adsorption film. The amount may be applied.
潤滑剤の有機溶媒溶液は、磁性薄膜表面に必要量を塗
布した直後に５℃〜25℃の温度範囲の空気を送風して有
機溶媒を蒸発させ、この温度で乾燥することにより、磁
性薄膜表面に単分子膜層となって強固に吸着し、トップ
コート層を形成する。Immediately after the required amount of the organic solvent solution of the lubricant is applied to the surface of the magnetic thin film, air in a temperature range of 5 ° C. to 25 ° C. is blown to evaporate the organic solvent, and the organic thin film is dried at this temperature. Then, a monomolecular film layer is firmly adsorbed to form a top coat layer.
この単分子膜層は、ラングミュアブロジェット（LB）
膜と同程度と吸着断面積をもち、非常によく配向した膜
であるので、潤滑剤の性能を最大限に発揮することがで
き、磁気記録媒体の耐久性、走行性に優れた効果をもた
らす。This monolayer is made of Langmuir Blodget (LB)
It has the same adsorption cross-sectional area as the film and is a very well-oriented film, so it is possible to maximize the performance of the lubricant and bring about excellent effects on the durability and running properties of the magnetic recording medium .
以下、本発明の具体的な実施例について、図面を参照
しながら説明する。Hereinafter, specific examples of the present invention will be described with reference to the drawings.
本発明による磁気記録媒体の断面を示す第１図におい
て、例えば14μｍ厚さのポリエチレンテレフタレート
（PET）フィルムからなる非磁性支持体３上に、例えばC
o80Ni20合金を斜め蒸着法により1000Åの厚みに連続蒸
着し、磁性薄膜２を形成した。In FIG. 1 which shows a cross section of a magnetic recording medium according to the present invention, for example, a non-magnetic support 3 made of polyethylene terephthalate (PET) film having a thickness of 14 μm, for example,
A magnetic thin film 2 was formed by continuously depositing an o80Ni20 alloy to a thickness of 1000 mm by an oblique deposition method.
潤滑剤として特開昭62−161744号公報記載のペンタデ
カフルオロオクチルリノレナート（C7H29COOCH2C7F15、
M.W.B＝660）をｎ−オクタンに45mg/の濃度で溶解
し、この溶液をグラビア転写方式により磁性薄膜２上に
塗布した、潤滑剤溶液の塗布量は磁性薄膜２の単位表面
積（1m2）あたり29.3mlすなわち潤滑剤重量に換算して
1.32mgとなるようにグラビアロールを選んだ。この塗布
量は、分子量より計算して、磁性薄膜表面に単分子吸着
膜を形成するのに相当するものである。塗布直後に15℃
の乾燥空気を塗布面に送風し、この温度で溶媒を蒸発さ
せて完全に乾燥し、トップコート層１を設けた。得られ
た薄膜型の磁気記録媒体のジャンボロールをスリッタに
より8.0mm幅に裁断してパンケーキとした後、所定の長
さに切断して８ミリVTR用カセットに装填し、測定用サ
ンプルテープとした。Pentadecafluorooctyl Reno Renato of JP 62-161744 Laid described as a lubricant (C 7 H 29 COOCH 2 C 7 F 15,
MWB = 660) was dissolved in n-octane at a concentration of 45 mg /, and this solution was applied on the magnetic thin film 2 by a gravure transfer method. The amount of the lubricant solution applied was per unit surface area (1 m 2 ) of the magnetic thin film 2 29.3ml, i.e. in terms of lubricant weight
The gravure roll was chosen to be 1.32 mg. This coating amount is equivalent to forming a monomolecular adsorption film on the surface of the magnetic thin film, calculated from the molecular weight. 15 ° C immediately after application
Was blown to the coated surface, and the solvent was evaporated at this temperature to complete drying, and the top coat layer 1 was provided. The obtained thin film type magnetic recording medium was cut into a 8.0 mm wide pancake by slitting the jumbo roll into a pancake, cut into a predetermined length, and loaded into an 8 mm VTR cassette, and then attached to a sample tape for measurement. did.
次に、本実施例によるペンタデカフルオロオクチルリ
ノレナートの磁性薄膜２への吸着様式について考察を行
う。Next, the manner of adsorption of pentadecafluorooctyl linolenate to the magnetic thin film 2 according to the present embodiment will be discussed.
第２図はペンタデカフルオロオクチルリノレナートを
通常のLB膜作成装置により水面上に展開したときの表面
圧IIと分子占有面積Ａの関係を示すII−Ａ曲線である。
第２図からは、ペンタデカフルオロオクチルリノレナー
トは、液体膨張膜（ａ〜ｂ領域）より液体凝縮膜となら
ずに、ｂ点で表面圧IIがほぼ一定となるが、このときの
横軸の値から、ペンタデカフルオロオクチルリノレナー
トの分子占有面積は約85Å2/分子であることが判る。FIG. 2 is an II-A curve showing the relationship between surface pressure II and molecular occupied area A when pentadecafluorooctyl linolenate is spread on the water surface by a normal LB film forming apparatus.
From FIG. 2, it can be seen that pentadecafluorooctyl linolenate does not become a liquid condensate film than the liquid expansion film (regions a and b) and the surface pressure II is substantially constant at point b. From the value of 値, it is found that the molecular occupation area of pentadecafluorooctyllinolenate is about 85Å 2 / molecule.
一方第３図は、本実施例で用いた磁性薄膜の合金組成
と同じCo80Ni20組成の酸化物粉へのペンタデカフルオロ
オクチルリノレナートの吸着等温線である。この酸化物
粉の比表面積は、BET法により測定した結果、0.91m2/g
であった。On the other hand, FIG. 3 is an adsorption isotherm of pentadecafluorooctyllinolenate to an oxide powder having the same Co80Ni20 composition as the alloy composition of the magnetic thin film used in this example. The specific surface area of this oxide powder was measured by the BET method and found to be 0.91 m 2 / g
Met.
第３図から求められるペンタデカフルオロオクチルリ
ノレナートの吸着熱は9kcal/molであり、発熱現象であ
る。また、一般的にも潤滑剤の磁性薄膜表面への吸着は
発熱現象であり、従って温度が低いほど吸着量は増加
し、単分子吸着を行う潤滑剤溶液濃度低くてすむことに
なる。第３図からは、吸着量は明らかに低温となるほど
大きくなり、1.2mg/gすなわち表面積換算1.32mg/m2でほ
ぼ単分子飽和吸着量に達するが、25℃を越えるとこの単
分子飽和吸着量に達しないことが判る。この酸化物粉
は、本実施例で用いたCo80Ni20合金からなる磁性薄膜と
同一の表面組成をもつことがESCAによる表面分析により
確認された。これは、磁性薄膜の表面が蒸着装置内の微
量の酸素と化学反応をおこし、ごく薄い酸化物層で覆わ
れていることを示している。The heat of adsorption of pentadecafluorooctyllinolenate determined from FIG. 3 is 9 kcal / mol, which is an exothermic phenomenon. Also, in general, the adsorption of the lubricant on the surface of the magnetic thin film is an exothermic phenomenon. Therefore, the lower the temperature is, the more the amount of adsorption increases, and the lower the concentration of the lubricant solution used for single molecule adsorption becomes. From FIG. 3, it can be seen that the amount of adsorption clearly increases as the temperature becomes lower, and reaches almost a monomolecular saturated adsorption amount at 1.2 mg / g, that is, 1.32 mg / m 2 in terms of surface area. It turns out that quantity is not reached. This oxide powder was confirmed by ESCA to have the same surface composition as the magnetic thin film made of the Co80Ni20 alloy used in this example. This indicates that the surface of the magnetic thin film undergoes a chemical reaction with a small amount of oxygen in the vapor deposition device and is covered with an extremely thin oxide layer.
前記BET法による比表面積測定結果より、ペンタデカ
フルオロオクチルリノレナートの一分子あたりのCo80Ni
20酸化物粉への吸着面積Aoは次式により算出される。From the specific surface area measurement result by the BET method, Co80Ni per molecule of pentadecafluorooctyl linolenate
20 The adsorption area Ao on the oxide powder is calculated by the following equation.
上式において、 Ｓ……被吸着材料の比表面積（Å2/g） Ｍ……吸着物質の分子量 ｍ……被吸着材料の単位重量あたりの飽和吸着量
（mg/g） Ｎ……アボガドロ数 であり、この計算式をCo80Ni20組成の酸化物粉へのペン
タデカフルオロオクチルリノレナートの吸着に適用する
と、 の計算結果が得られる。この値は、先にII−Ａ曲線によ
り求めたペンタデカフルオロオクチルリノレナートの分
子占有面積85（Å2/分子）とほぼ一致する。すなわち、
15℃において潤滑剤溶液を塗布・乾燥させると、LB膜法
により形成した単分子膜とほぼ同程度の非常によく配向
された吸着膜となることがわかる。 In the above formula, S: specific surface area of the material to be adsorbed (Å 2 / g) M: molecular weight of the adsorbed material m: saturated amount of adsorbed material per unit weight (mg / g) N: Avogadro's number Applying this calculation formula to the adsorption of pentadecafluorooctyl linolenate onto oxide powder of Co80Ni20 composition, Is obtained. This value substantially coincides with the molecular occupation area of pentadecafluorooctyllinolenate of 85 (Å 2 / molecule) previously determined from the II-A curve. That is,
It can be seen that when the lubricant solution is applied and dried at 15 ° C., a very well-oriented adsorption film is obtained, which is almost the same as a monomolecular film formed by the LB film method.
比較例 次に比較例として、前記実施例と全く同様に非磁性支
持体上に磁性薄膜を形成し、同じ潤滑剤溶液を同じ塗布
量だけ塗布し、乾燥工程のみ65℃の熱風を送って強制乾
燥した。得られたジャンボロールをスリッタにより8mm
幅に裁断してパンケーキとした後、所定の長さに切断し
て８ミリVTR用カセットに装填し、測定用サンプルテー
プとした。Comparative Example Next, as a comparative example, a magnetic thin film was formed on the non-magnetic support in exactly the same manner as in the above example, the same lubricant solution was applied in the same amount, and hot air at 65 ° C. was sent only in the drying step and forcedly applied. Dried. 8mm obtained jumbo roll by slitter
After being cut into a pancake by cutting into a width, the pancake was cut into a predetermined length and loaded into an 8 mm VTR cassette to obtain a sample tape for measurement.
上述のように作成した各サンプルテープについて、各
測定環境条件下で、動摩擦係数、および家庭用８ミリVT
Rによる実走行試験によるスチル耐久性のシャトル耐久
性を測定した。測定環境条件としては、25℃60％RH、40
℃80％RHおよび−５℃の３条件を選んだ。動摩擦係数
は、ステンレスSUS304製のガイドピンに各サンプルテー
プの磁性薄膜面側を接触させ、一定の荷重をかけて5mm/
secの定速度で走行させて測定した。スチル耐久性は、
各サンプルテープに5.5MHzの試験信号を記録し、スチル
モードでテープの同一個所を再生し続け、再生出力が初
期再生出力の−3dBとなるまでの時間を評価した。ま
た、シャトル耐久性については、各サンプルテープに同
じく5.5MHzの試験信号を記録し、１回あたり２分間のシ
ャトル走行再生を繰り返し、再生出力が初期再生出力の
−3dBとなるまでのシャトル回数を評価対象とした。測
定結果を次表に示す。For each sample tape prepared as described above, the dynamic friction coefficient and the household 8 mm
Shuttle durability of still durability was measured by an actual running test using R. Measurement environment conditions are: 25 ° C 60% RH, 40
Three conditions of 80% RH and -5 ° C were selected. The coefficient of kinetic friction was measured by contacting the magnetic thin film side of each sample tape with a stainless steel SUS304 guide pin, applying a constant load to 5 mm /
It was measured by running at a constant speed of sec. Still durability is
A 5.5 MHz test signal was recorded on each sample tape, and the same portion of the tape was continuously reproduced in the still mode, and the time until the reproduction output became −3 dB of the initial reproduction output was evaluated. Regarding shuttle durability, the same 5.5MHz test signal was recorded on each sample tape, and shuttle playback was repeated for 2 minutes each time, and the number of shuttles until the playback output reached -3dB of the initial playback output was calculated. It was evaluated. The measurement results are shown in the following table.
上表より明らかなように、本発明の実施例によるサンプ
ルテープは、各測定環境条件下において、比較例による
サンプルテープより動摩擦係数が小さく、走行状態が安
定していた。また実走行試験後に磁性薄膜表面を顕微鏡
により拡大観察しても疵や損傷は認められなかったのに
対し、比較例によるサンプルテープは走行がやや不安定
であり、その磁性薄膜表面には、実走行試験後に、疵や
損傷が若干観察された。また、本発明の実施例によるサ
ンプルテープは、各測定条件下においてスチル耐久性18
0分超並びにシャトル耐久性250回超の測定結果が得ら
れ、実用上満足すべき特性であった。これに対し、65℃
の熱風乾燥を施した比較例によるサンプルテープは、ス
チル耐久性、シャトル耐久性とも不満足な特性であっ
た。 As is clear from the above table, the sample tape according to the example of the present invention had a smaller dynamic friction coefficient than the sample tape according to the comparative example and the running state was stable under each measurement environment condition. After the actual running test, no flaw or damage was observed even when the surface of the magnetic thin film was observed under magnification with a microscope. On the other hand, the running of the sample tape according to the comparative example was somewhat unstable. After the running test, some flaws and damage were observed. Further, the sample tape according to the embodiment of the present invention has a still durability of 18 under each measurement condition.
Measurement results of more than 0 minutes and a shuttle durability of more than 250 times were obtained, which were satisfactory characteristics for practical use. 65 ° C
The sample tape according to the comparative example subjected to hot air drying had unsatisfactory still durability and shuttle durability.
本実施例においては、潤滑剤溶液の乾燥温度を15℃に
選んだが、この乾燥温度は５℃〜25℃の間で選ぶことが
可能であり、この温度範囲で潤滑剤溶液を乾燥して作成
したサンプルテープについて測定した結果、前記実施例
によるサンプルテープと同じ摩擦係数と実走行試験結果
が選られ、実用特性上満足すべきものであった。In the present embodiment, the drying temperature of the lubricant solution was selected to be 15 ° C., but the drying temperature can be selected from 5 ° C. to 25 ° C., and the lubricant solution is dried in this temperature range. As a result of the measurement of the sample tape, the same coefficient of friction and the result of the actual running test as those of the sample tape according to the above example were selected, which were satisfactory in practical characteristics.
一方、乾燥温度が25℃を超えると、第３図の吸着等温
線より明らかなように、磁性薄膜表面への潤滑剤の吸着
量が飽和値に達せず、単分子吸着膜を作ることができな
い。また、５℃に満たない冷風乾燥を行うと、吸着等温
曲線からは飽和吸着が可能である。しかし、実際の工程
上では溶媒の蒸発・乾燥が不充分なことや、また潤滑剤
の種類によっては、例えば常温で固体の潤滑剤を選んだ
場合には、塗布むらになり易く、歩留りの低下となり好
ましくない。On the other hand, when the drying temperature exceeds 25 ° C., the amount of the lubricant adsorbed on the surface of the magnetic thin film does not reach the saturation value, as is apparent from the adsorption isotherm in FIG. 3, and a monomolecular adsorption film cannot be formed. . Further, when cold-air drying of less than 5 ° C. is performed, saturation adsorption is possible from the adsorption isotherm curve. However, in the actual process, evaporation and drying of the solvent are insufficient, and depending on the type of lubricant, when a solid lubricant is selected at room temperature, for example, application unevenness is likely to occur, and the yield decreases. Is not preferred.
本発明においては、潤滑剤としてペンタデカフルオロ
オクチルリノレナートを選んだが、他の潤滑剤、例えば
前記特開昭62−161744号公報記載の一連のパーフルオロ
カルボン酸エステル類や他のフッ素化合物系潤滑剤を選
んでも、その溶媒溶液の乾燥温度を５℃〜25℃の範囲に
選択することにより、薄膜型磁気記録媒体としての動摩
擦係数の低下および実走行上の耐久性の向上が認められ
た。また、潤滑剤溶液の塗布方法として、本発明のよう
なグラビア転写方式の他に、リバースロール方式や刷子
による塗布、噴霧による方式、さらには潤滑剤溶液中に
直接浸漬する方法が可能であり、要は潤滑剤が単分子吸
着膜を形成する相当する量を均一に塗布すればよい。さ
らに、第１図には記していないが、磁性薄膜２の反対側
の非磁性支持体３上に、カーボン粉末を主成分とする塗
料を塗布してバックコート層を設けてもよい。さらにま
た、磁性薄膜として、本実施例にはCo−Ni合金の斜め蒸
着による例を示したが、他の薄膜型磁気記録媒体、例え
ばCo−Cr合金のスパッタリングによる垂直記録型ディス
ク等においても、本発明による潤滑剤塗布乾燥方法によ
るトップコート層を設けることにより、動摩擦係数の低
下および走行耐久性の向上が顕著に認められた。In the present invention, pentadecafluorooctyl linolenate was selected as a lubricant, but other lubricants, such as a series of perfluorocarboxylic acid esters and other fluorine compound-based lubricants described in JP-A-62-161744 described above. Regardless of the choice of the agent, by selecting the drying temperature of the solvent solution in the range of 5 ° C. to 25 ° C., it was confirmed that the dynamic friction coefficient as a thin-film magnetic recording medium was reduced and the durability in actual running was improved. Further, as a method of applying a lubricant solution, in addition to the gravure transfer method as in the present invention, a reverse roll method or application by a brush, a method by spraying, and a method of directly immersing in a lubricant solution are possible. In short, it is only necessary to apply a uniform amount of the lubricant to form a monomolecular adsorption film. Further, although not shown in FIG. 1, a back coat layer may be provided by applying a paint containing carbon powder as a main component on the non-magnetic support 3 opposite to the magnetic thin film 2. Furthermore, as the magnetic thin film, the present embodiment shows an example of oblique deposition of a Co-Ni alloy, but other thin-film magnetic recording media, for example, a perpendicular recording type disk by sputtering of a Co-Cr alloy, etc. By providing the top coat layer by the method of applying and drying a lubricant according to the present invention, a reduction in dynamic friction coefficient and an improvement in running durability were remarkably recognized.
以上詳細に説明したように、薄膜型磁気記録媒体の磁
性薄膜表面に潤滑剤のトップコート層を設けるにあた
り、潤滑剤溶液の塗布直後の乾燥条件を５℃〜25℃の温
度範囲に選ぶことにより、潤滑剤の性能を最大限に発揮
する単分子層膜が形成され、熱風乾燥による方法と比較
して、動摩擦係数の低下による走行安定性並びに実走行
における耐久性向上の効果が得られ、信頼性に優れた薄
膜型磁気記録媒体の生産に寄与するところが大きい。As described in detail above, in providing the top coat layer of the lubricant on the surface of the magnetic thin film of the thin film type magnetic recording medium, the drying condition immediately after the application of the lubricant solution is selected in a temperature range of 5 ° C. to 25 ° C. , A monolayer film that maximizes the performance of the lubricant is formed, and compared with the method using hot air drying, the effect of improving the running stability and the durability in actual running due to the reduction of the dynamic friction coefficient is obtained. This greatly contributes to the production of a thin-film magnetic recording medium having excellent performance.
第１図は本発明による磁気記録媒体の断面図、第２図は
ペンタデカフルオロオクチルリノレナートのII−Ａ曲線
を示す図、第３図はペンタデカフルオロオクチルリノレ
ナートのCo80Ni20酸化物粉への吸着等温線を示す図であ
る。 １……トップコート層 ２……磁性薄膜 ３……非磁性支持体FIG. 1 is a cross-sectional view of a magnetic recording medium according to the present invention, FIG. 2 is a diagram showing an II-A curve of pentadecafluorooctyl linolenate, and FIG. 3 is a graph showing pentadecafluorooctyl linolenate to Co80Ni20 oxide powder. It is a figure which shows an adsorption isotherm. 1 top coat layer 2 magnetic thin film 3 non-magnetic support
Claims (1)
磁気記録媒体の前記磁性薄膜表面に潤滑剤溶液を塗布
し、次に５℃以上25℃以下の空気を塗布面に送風して、
この温度範囲内で潤滑剤溶液中の溶媒を蒸発させ、乾燥
することを特徴とする磁気記録媒体の製法。1. A lubricant solution is applied to the surface of a magnetic thin film of a magnetic recording medium having a magnetic thin film formed on a non-magnetic support, and then air of 5 ° C. or more and 25 ° C. or less is blown to the coated surface. hand,
A method for producing a magnetic recording medium, wherein the solvent in the lubricant solution is evaporated and dried within this temperature range.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP26825688A JP2794580B2 (en) | 1988-10-26 | 1988-10-26 | Manufacturing method of magnetic recording media |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP26825688A JP2794580B2 (en) | 1988-10-26 | 1988-10-26 | Manufacturing method of magnetic recording media |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02116027A JPH02116027A (en) | 1990-04-27 |
| JP2794580B2 true JP2794580B2 (en) | 1998-09-10 |
Family
ID=17456051
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP26825688A Expired - Fee Related JP2794580B2 (en) | 1988-10-26 | 1988-10-26 | Manufacturing method of magnetic recording media |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2794580B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU4496799A (en) * | 1998-04-15 | 1999-11-08 | Extreme Energy And Power Company Limited | Loading especially metallic or metal-ceramic technical surfaces with a fluoro-organic compound |
-
1988
- 1988-10-26 JP JP26825688A patent/JP2794580B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH02116027A (en) | 1990-04-27 |
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