JPH0250530B2 - - Google Patents
Info
- Publication number
- JPH0250530B2 JPH0250530B2 JP5724184A JP5724184A JPH0250530B2 JP H0250530 B2 JPH0250530 B2 JP H0250530B2 JP 5724184 A JP5724184 A JP 5724184A JP 5724184 A JP5724184 A JP 5724184A JP H0250530 B2 JPH0250530 B2 JP H0250530B2
- Authority
- JP
- Japan
- Prior art keywords
- magnetic
- magnetic coating
- coating film
- resin
- lubricant
- 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
- 238000000576 coating method Methods 0.000 claims description 41
- 239000011248 coating agent Substances 0.000 claims description 39
- 239000000314 lubricant Substances 0.000 claims description 28
- 229920005989 resin Polymers 0.000 claims description 26
- 239000011347 resin Substances 0.000 claims description 26
- 229920005992 thermoplastic resin Polymers 0.000 claims description 23
- 229920001187 thermosetting polymer Polymers 0.000 claims description 15
- 239000002904 solvent Substances 0.000 claims description 11
- 238000000034 method Methods 0.000 claims description 10
- 239000006247 magnetic powder Substances 0.000 claims description 9
- 239000000758 substrate Substances 0.000 claims description 6
- 239000008199 coating composition Substances 0.000 claims description 5
- 239000011230 binding agent Substances 0.000 claims description 2
- 238000004519 manufacturing process Methods 0.000 claims description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 10
- 229920002432 poly(vinyl methyl ether) polymer Polymers 0.000 description 9
- 238000005470 impregnation Methods 0.000 description 7
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 6
- 239000002202 Polyethylene glycol Substances 0.000 description 6
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 6
- 238000000605 extraction Methods 0.000 description 6
- 239000000203 mixture Substances 0.000 description 6
- 229920001223 polyethylene glycol Polymers 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 5
- 239000003822 epoxy resin Substances 0.000 description 5
- 235000019441 ethanol Nutrition 0.000 description 5
- 229920000647 polyepoxide Polymers 0.000 description 5
- 229920000178 Acrylic resin Polymers 0.000 description 4
- 239000004925 Acrylic resin Substances 0.000 description 4
- 239000005011 phenolic resin Substances 0.000 description 4
- 238000001179 sorption measurement Methods 0.000 description 4
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 3
- 230000003247 decreasing effect Effects 0.000 description 3
- 238000007654 immersion Methods 0.000 description 3
- 229940057995 liquid paraffin Drugs 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 238000005498 polishing Methods 0.000 description 3
- 239000011148 porous material Substances 0.000 description 3
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 2
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical compound CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 description 2
- 239000004698 Polyethylene Substances 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- LNEPOXFFQSENCJ-UHFFFAOYSA-N haloperidol Chemical compound C1CC(O)(C=2C=CC(Cl)=CC=2)CCN1CCCC(=O)C1=CC=C(F)C=C1 LNEPOXFFQSENCJ-UHFFFAOYSA-N 0.000 description 2
- 239000003960 organic solvent Substances 0.000 description 2
- 229920001568 phenolic resin Polymers 0.000 description 2
- -1 polyethylene Polymers 0.000 description 2
- 229920000573 polyethylene Polymers 0.000 description 2
- 238000004381 surface treatment Methods 0.000 description 2
- 229920002554 vinyl polymer Polymers 0.000 description 2
- 239000008096 xylene Substances 0.000 description 2
- DURPTKYDGMDSBL-UHFFFAOYSA-N 1-butoxybutane Chemical compound CCCCOCCCC DURPTKYDGMDSBL-UHFFFAOYSA-N 0.000 description 1
- KXGFMDJXCMQABM-UHFFFAOYSA-N 2-methoxy-6-methylphenol Chemical compound [CH]OC1=CC=CC([CH])=C1O KXGFMDJXCMQABM-UHFFFAOYSA-N 0.000 description 1
- 229920001342 Bakelite® Polymers 0.000 description 1
- 239000004640 Melamine resin Substances 0.000 description 1
- 229920000877 Melamine resin Polymers 0.000 description 1
- 239000004372 Polyvinyl alcohol Substances 0.000 description 1
- 229920000297 Rayon Polymers 0.000 description 1
- 229920001807 Urea-formaldehyde Polymers 0.000 description 1
- 229920000180 alkyd Polymers 0.000 description 1
- 150000005215 alkyl ethers Chemical class 0.000 description 1
- 229910001566 austenite Inorganic materials 0.000 description 1
- 239000004637 bakelite Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- MTHSVFCYNBDYFN-UHFFFAOYSA-N diethylene glycol Chemical compound OCCOCCO MTHSVFCYNBDYFN-UHFFFAOYSA-N 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000005007 epoxy-phenolic resin Substances 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- NBVXSUQYWXRMNV-UHFFFAOYSA-N fluoromethane Chemical compound FC NBVXSUQYWXRMNV-UHFFFAOYSA-N 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 238000004898 kneading Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- XJRBAMWJDBPFIM-UHFFFAOYSA-N methyl vinyl ether Chemical compound COC=C XJRBAMWJDBPFIM-UHFFFAOYSA-N 0.000 description 1
- 239000003973 paint Substances 0.000 description 1
- 229920002451 polyvinyl alcohol Polymers 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- 229920001169 thermoplastic Polymers 0.000 description 1
- 229920002803 thermoplastic polyurethane Polymers 0.000 description 1
- 239000004416 thermosoftening plastic Substances 0.000 description 1
- 239000000052 vinegar Substances 0.000 description 1
- 235000021419 vinegar Nutrition 0.000 description 1
Description
発明の技術分野
本発明は磁気記録媒体の製造方法に係り、磁性
塗膜に含浸する潤滑剤の量を増加する技術に関す
る。
技術の背景
磁気記録媒体はアルミニウム等の基板上に形成
した磁性粉を含む磁性塗膜からなる。コンタク
ト・スタート・ストツプと呼ばれる操作では、磁
気ヘツドを直接に磁気記録媒体上に置き、磁気記
録媒体の回転によつて磁気ヘツドを浮上させて使
用する。従つて、磁気ヘツドと磁気記録媒体の間
に摩擦抵抗が働き、磁気記録媒体が傷つけられ
る。そこで、磁気記録媒体の表面に潤滑剤を塗布
し、磁気記録媒体と磁気ヘツドの間の接触抵抗を
低減させている。
従来技術と問題点
上記のように、磁気記録媒体表面に潤滑剤を塗
布して使用するが、潤滑剤が表面に多くあると、
磁気ヘツドが磁気記録媒体表面に吸着され（吸着
現象）、磁気記録媒体の回転時にヘツドクラツシ
ユを起こしてしまう。従つて、磁気記録媒体表面
に潤滑剤を塗布するといつても、多量に潤滑剤を
塗布するわけにいかず、磁気記録媒体の機械的強
度（耐久力）には不安がある。
そこで、磁性塗膜の表面に機械的キズを形成し
たり、流動パラフインを用いて磁性塗膜内部に機
械的な孔を形成して、潤滑剤をより多量に含浸さ
せれば（特開昭54−076699）、確かに磁気記録媒
体（磁性塗膜）の機械的強度は上昇するが、キズ
や孔の寸法がどうしても数μmのオーダーになり、
信号の記録にエラーが発生し、信頼性が低下す
る。
発明の目的
本発明は、以上の如き従来技術に鑑み、信号エ
ラーの心配のない形で、より多くの潤滑剤を磁性
塗膜に含浸する方法を提供することを目的とす
る。
発明の構成
本発明では、上記目的を達成するために、磁性
粉を熱硬化性樹脂で結合してなる磁性塗膜におい
て、磁性塗料組成物中に熱硬化性樹脂と相溶性の
ある熱可塑性樹脂を配合しておき、磁性塗料を基
板上に塗布した後、熱硬化性樹脂を不完全に硬化
させて（一次焼付け）溶媒に不溶化させてから、
熱可塑性樹脂をアルコール、水等の溶媒で抽出除
去する。それから、磁性塗膜を完全に硬化させ
（二次焼付け）、表面仕上げを行なつた後、潤滑剤
を含浸する。
この方法では、熱可塑性樹脂を抽出することに
よつて磁性塗膜中に形成されるミクロな孔に潤滑
剤を含浸するものである。熱可塑性樹脂は他の樹
脂とは反応せず、単独で存在し、また他の樹脂の
反応自体もまだ完全ではなく、塗膜中で緩く結合
しているために、熱可塑性樹脂は溶媒によつて容
易に抽出される。また、熱硬化性樹脂と相溶性の
ある熱可塑性樹脂を用いるので、熱可塑性樹脂は
磁性塗料中に均一かつ微細に分散し、そのため熱
可塑性樹脂抽出後のミクロな孔は極めて微細であ
る。こうして、多量の潤滑剤を含浸でき、かつ信
号エラー発生のない磁性塗膜が得られる。
なお、熱可塑性樹脂を抽出除去してから磁性塗
膜（熱硬化性樹脂）を再度硬化するが、それによ
つて磁性塗膜中のミクロな孔が塞がれ、潤滑剤が
含浸できなくなることはなかつた。一方、熱可塑
性樹脂の抽出除去処理前に、磁性塗膜（熱硬化性
樹脂）を高温で処理するなどして完全に硬化させ
ると、熱可塑性樹脂の抽出が困難さらには不可能
になることが確認された。
磁気デイスクの磁性塗膜において磁性粉を結合
する熱硬化性樹脂としては、エポキシ樹脂または
エポキシ・フエノール系樹脂が一般的な骨格材料
として用いられているが、その他にもアクリル樹
脂、熱可塑性ポリウレタン樹脂、尿素樹脂、アル
キド樹脂、メラミン樹脂等が副バインダ的に使用
されている。こうした熱硬化性樹脂に対して相溶
性のある熱可塑性樹脂としては、ポリビニルメチ
ルエーテル、ポリビニルエチルエーテル、または
ポリビニルブチルエーテルのようなポリビニルア
ルキルエーテル（PVAE）、ポリエチレングリコ
ール（PEG）、ポリエチレングリコールエステ
ル、ポリエチレングリコールエーテル酢酸繊維束
等のように溶解パラメータがフエノール樹脂、エ
ポキシ樹脂に近いものが良い。特にPVAEは好ま
しい相溶性熱可塑性樹脂である。PVAEは少なく
ともフエノール樹脂、エポキシ樹脂、アクリル樹
脂の各樹脂と相溶性があることが確認されてい
る。
一次焼付け後に熱可塑性樹脂を抽出する溶媒と
しては、基本的に熱可塑性樹脂を溶解するもので
あれば何でもよく、有機溶剤に限らず、水その他
であつてもよい。熱硬化性樹脂は一次焼付け（１
次硬化）されているので一般的にいつて溶媒に溶
解しにくいからである。熱可塑性樹脂はトルエ
ン、キシレン等の有機溶剤に溶解しやすいが、
PVAEやPEGなどでは水にも溶解するので、水
を抽出溶媒として用いることができる。水を抽出
溶媒として用いる場合には作業環境が良好であ
る、防爆装置が不要である等の利点がある。
磁性塗膜は、一般に、磁性粉45〜85重量％と残
りが樹脂からなり、熱可塑性樹脂は全樹脂中３〜
15重量％であり、ただし磁性粉が多い場合は少な
い方がよい。好ましくは、磁性粉55〜75重量％と
残りが樹脂からなり、熱可塑性樹脂は全樹脂中５
〜30重量％である。
発明の実施例
例 １
下記の組成（重量部）の磁性塗料組成物を作成
した。
磁性粉（γ−Fe2O3.長軸0.5〜0.8μm） 55.0
熱硬化性樹脂：
エポキシ樹脂（シエル化学社、エピコート
Ep1001） 20.5
フエノール樹脂（昭和ユニオン合成社、ベー
クライトBKR2620） 8.0
アクリル樹脂（三菱レーヨン社、デユラクロ
ンSE5437） 6.5
熱可塑性樹脂；
ポリビニルメチルエーテル樹脂（BASF、ル
トナールM40） 10.0
溶剤：
トルエン 180.0
キシレン 170.0
酢錯セロソルブ 60.0
上記成分をボールミルあるいはサンドミルで混
練し、８〜14インチのアルミニウム基板にスピン
コートし、厚さ1μmの磁性塗膜を形成し、170℃
で１時間硬化させた。次いで、エチルアルコール
（一般にアルコール、セルソルブが好ましい）中
に浸漬した。抽出物を分析したところ、ポリビニ
ルメチルエーテル樹脂だけが検出された。また、
浸漬前後の重量測定から、磁性塗膜中のポリビニ
ルメチルエーテルは殆んど抽出されることが確認
できた。
続いて、250℃で１時間再度硬化させた。それ
から、磁性塗膜表面を研摩し、表面処理を行なう
等、通常の磁気デイスク同様の手順で加工した。
こうして得られた磁性塗膜の断面を電子顕微鏡
観察したが、孔を観察することはできなかつた。
従つて、磁性塗膜中の熱可塑性樹脂抽出後の空所
（ミクロな孔）は極めて小さい寸法であることが
窺える。
こうして作成した磁気デイスクの磁性塗膜に既
定量の潤滑剤（フルオロカーボン系オイル、デユ
ポン社の商品名「クライトツクス」）を塗布し、
ヘツドを載せて磁気デイスクを回転させてみて、
ヘツドの吸着力を測定した。塗布する潤滑剤を増
加してゆき、吸着力が急に増大する直前の潤滑剤
塗布量をもつて潤滑剤を含浸量とした。
ヘツド吸着が大きくならない範囲でできるだけ
多くの潤滑剤を含浸させた磁気デイスクで、コン
タクト・スタート・ストツプ（CSS）の操作を操
り返し、操作が可能であつた回数を調べ、CSS強
度とした。
潤滑剤を含浸した磁気デイスクに正弦波の信号
を書き込み、その信号を読み出す際に所定のスレ
ツシヨルドレベルの読み出しができなかつた場合
を信号エラーとして、磁気デイスクの全面での信
号エラー数を数えた。
以上の結果は後出の表に示す。その際、潤滑剤
含浸量は、本例の含浸量を1.0とする相対値（相
対含浸量）で表わしている。
添付図面は、１次焼付け温度に関する相対含浸
性を示すグラフである。これは、上記と同じ手順
に従うが、ポリビニルメチルエーテルの抽出前の
磁性塗膜硬化処理（１次焼きつけ）の温度を種々
変えて（１次焼付け時間は１時間、そして２次焼
付けは250℃、１時間として一定にした）磁気デ
イスクを作成し、そのそれぞれについて潤滑剤含
浸量を測定して、作成したものである。グラフか
ら、１次焼付け温度が高いと（即ち、磁性塗膜が
硬化しすぎると）、含浸量が低下すること（即ち、
熱可塑性樹脂の抽出が困難または不可能になるこ
と）がわかる。また、１次焼付け温度が低すぎる
と、エラーの発生がみられるようになる。この例
では、160〜200℃程度が１次焼付けの好ましい温
度であることがわかる。
例 ２〜10
これらの例ではすべて例１と同様の手法で磁気
デイスクを作成し、その特性を評価した。但し、
樹脂の組成を下記表の如くした（参考のため例１
の組成も示す）。なお、例１〜９は実施例、例10
は比較例である。
TECHNICAL FIELD OF THE INVENTION The present invention relates to a method of manufacturing a magnetic recording medium, and more particularly to a technique for increasing the amount of lubricant impregnated into a magnetic coating film. Background of the Technology A magnetic recording medium consists of a magnetic coating film containing magnetic powder formed on a substrate such as aluminum. In an operation called contact start/stop, the magnetic head is placed directly on the magnetic recording medium, and the magnetic head is levitated by the rotation of the magnetic recording medium. Therefore, frictional resistance acts between the magnetic head and the magnetic recording medium, damaging the magnetic recording medium. Therefore, a lubricant is applied to the surface of the magnetic recording medium to reduce the contact resistance between the magnetic recording medium and the magnetic head. Prior Art and Problems As mentioned above, lubricant is applied to the surface of a magnetic recording medium, but if there is too much lubricant on the surface,
The magnetic head is attracted to the surface of the magnetic recording medium (adsorption phenomenon), causing head crash when the magnetic recording medium rotates. Therefore, even if a lubricant is applied to the surface of a magnetic recording medium, it is impossible to apply a large amount of the lubricant, and there is concern about the mechanical strength (durability) of the magnetic recording medium. Therefore, it is possible to impregnate a larger amount of lubricant by forming mechanical scratches on the surface of the magnetic coating film or by forming mechanical holes inside the magnetic coating film using liquid paraffin (Japanese Unexamined Patent Publication No. 54 -076699), it is true that the mechanical strength of magnetic recording media (magnetic coatings) increases, but the dimensions of scratches and holes inevitably become on the order of several μm.
Errors occur in signal recording, reducing reliability. OBJECTS OF THE INVENTION In view of the above-mentioned prior art, it is an object of the present invention to provide a method for impregnating a magnetic coating film with more lubricant without worrying about signal errors. Structure of the Invention In order to achieve the above object, the present invention provides a magnetic coating film formed by bonding magnetic powder with a thermosetting resin, in which a thermoplastic resin that is compatible with the thermosetting resin is included in the magnetic coating composition. After mixing the magnetic paint and applying it to the substrate, the thermosetting resin is completely cured (primary baking) to make it insoluble in the solvent.
The thermoplastic resin is extracted and removed using a solvent such as alcohol or water. Then, the magnetic coating film is completely cured (secondary baking), the surface is finished, and then a lubricant is impregnated. In this method, a lubricant is impregnated into the micropores formed in the magnetic coating by extracting the thermoplastic resin. Thermoplastic resins do not react with other resins and exist alone, and the reaction of other resins itself is not yet complete and they are loosely bonded in the coating film, so thermoplastic resins do not react with solvents. It is easily extracted. Furthermore, since a thermoplastic resin that is compatible with the thermosetting resin is used, the thermoplastic resin is uniformly and finely dispersed in the magnetic coating material, so that the microscopic pores after the thermoplastic resin is extracted are extremely fine. In this way, a magnetic coating film that can be impregnated with a large amount of lubricant and that does not cause signal errors can be obtained. Note that the magnetic coating film (thermosetting resin) is hardened again after the thermoplastic resin is extracted and removed, but this will close the microscopic pores in the magnetic coating film and prevent the lubricant from impregnating it. Nakatsuta. On the other hand, if the magnetic coating film (thermosetting resin) is completely cured by processing it at high temperature before the extraction and removal process of the thermoplastic resin, extraction of the thermoplastic resin may become difficult or even impossible. confirmed. Epoxy resin or epoxy-phenolic resin is commonly used as a frame material for the thermosetting resin that binds magnetic powder in the magnetic coating film of magnetic disks, but acrylic resin and thermoplastic polyurethane resin are also used. , urea resin, alkyd resin, melamine resin, etc. are used as secondary binders. Thermoplastic resins that are compatible with these thermosetting resins include polyvinyl alkyl ethers (PVAE) such as polyvinyl methyl ether, polyvinylethyl ether, or polyvinyl butyl ether, polyethylene glycol (PEG), polyethylene glycol ester, polyethylene It is preferable to use materials with solubility parameters similar to those of phenol resins and epoxy resins, such as glycol ether acetic acid fiber bundles. In particular, PVAE is a preferred compatible thermoplastic. It has been confirmed that PVAE is compatible with at least phenolic resins, epoxy resins, and acrylic resins. The solvent for extracting the thermoplastic resin after the primary baking may basically be any solvent as long as it dissolves the thermoplastic resin, and is not limited to organic solvents, and may be water or other solvents. Thermosetting resins undergo primary baking (1
This is because they are generally difficult to dissolve in solvents because they have been cured (after curing). Thermoplastic resins are easily dissolved in organic solvents such as toluene and xylene, but
Since PVAE and PEG are also soluble in water, water can be used as an extraction solvent. When water is used as an extraction solvent, there are advantages such as a good working environment and no need for explosion-proof equipment. Magnetic coatings generally consist of 45 to 85% by weight of magnetic powder and the remainder resin, with thermoplastic resin accounting for 3 to 85% of the total resin.
The amount is 15% by weight, but if there is a lot of magnetic powder, less is better. Preferably, the magnetic powder is 55 to 75% by weight and the remainder is resin, with the thermoplastic resin accounting for 5% of the total resin.
~30% by weight. Examples of the Invention Example 1 A magnetic coating composition having the following composition (parts by weight) was prepared. Magnetic powder (γ-Fe 2 O 3 . Long axis 0.5 to 0.8 μm) 55.0 Thermosetting resin: Epoxy resin (Ciel Chemical Co., Ltd., Epicoat
Ep1001) 20.5 Phenol resin (Showa Union Gosei Co., Ltd., Bakelite BKR2620) 8.0 Acrylic resin (Mitsubishi Rayon Co., Ltd., Duracron SE5437) 6.5 Thermoplastic resin; Polyvinyl methyl ether resin (BASF, Lutonal M40) 10.0 Solvent: Toluene 180.0 Xylene 170.0 Vinegar complex cellosol Bu 60.0 Knead the above ingredients in a ball mill or sand mill, spin coat on an 8-14 inch aluminum substrate to form a 1 μm thick magnetic coating, and heat at 170°C.
It was cured for 1 hour. It was then immersed in ethyl alcohol (generally alcohol, Cellsolve being preferred). When the extract was analyzed, only polyvinyl methyl ether resin was detected. Also,
Weight measurements before and after dipping confirmed that most of the polyvinyl methyl ether in the magnetic coating was extracted. Subsequently, it was cured again at 250°C for 1 hour. Then, the surface of the magnetic coating was polished and processed in the same manner as a normal magnetic disk. A cross section of the magnetic coating thus obtained was observed under an electron microscope, but no pores could be observed.
Therefore, it can be seen that the voids (micropores) in the magnetic coating film after the thermoplastic resin has been extracted have extremely small dimensions. A predetermined amount of lubricant (fluorocarbon oil, Dupont's product name "Kritex") is applied to the magnetic coating film of the magnetic disk created in this way.
Try rotating the magnetic disk with the head on it,
The adsorption force of the head was measured. The amount of lubricant applied was increased, and the amount of lubricant applied just before the adsorption force suddenly increased was defined as the amount of lubricant impregnated. Using a magnetic disk impregnated with as much lubricant as possible without increasing head adsorption, contact start/stop (CSS) operations were repeated, and the number of times the operation was possible was determined and the CSS strength was determined. When a sine wave signal is written to a magnetic disk impregnated with lubricant, and when the signal cannot be read at a predetermined threshold level, it is considered a signal error, and the number of signal errors on the entire surface of the magnetic disk is counted. Ta. The above results are shown in the table below. In this case, the lubricant impregnation amount is expressed as a relative value (relative impregnation amount), with the impregnation amount in this example being 1.0. The accompanying drawing is a graph showing relative impregnability with respect to primary bake temperature. This follows the same procedure as above, but by varying the temperature of the magnetic coating hardening treatment (primary baking) before extraction of the polyvinyl methyl ether (primary baking time is 1 hour, and secondary baking is 250°C, The results were prepared by preparing magnetic disks (which were set at a constant rate of 1 hour) and measuring the amount of lubricant impregnated on each disk. The graph shows that when the primary baking temperature is high (i.e., the magnetic coating is too hardened), the amount of impregnation decreases (i.e., when the magnetic coating film is hardened too much).
This makes extraction of the thermoplastic resin difficult or impossible. Furthermore, if the primary baking temperature is too low, errors may occur. In this example, it can be seen that the preferred temperature for the primary baking is about 160 to 200°C. Examples 2 to 10 In all of these examples, magnetic disks were created using the same method as in Example 1, and their characteristics were evaluated. however,
The composition of the resin was as shown in the table below (for reference, Example 1
(also shows the composition of). In addition, Examples 1 to 9 are Examples, Example 10
is a comparative example.
【表】【table】
【表】
例 11（比較例）
例１におけると同じ組成で、１次焼付けの条件
を170℃、１時間ではなく、250℃、１時間（通常
の完全硬化の処理条件）とし、以降例１と同じ手
順で磁気デイスクを作成し、特性を評価した。
例 12（比較例）
例１と同じ組成物を、同じ手順で混練、塗布、
１次焼付け、アルコールを浸漬した後、２次焼付
けを行なうことなく、直ちに塗膜研摩、表面処理
等の加工を行なつて、磁気デイスクを作成した。
そして、磁気デイスクの特性を評価した。
例 13（比較例）
例12と同じ手順により混練、塗布、１次焼付
け、アルコール浸漬、塗膜研摩した後、２次焼付
けを行ない、それから表面処理等の加工を行な
い、磁気デイスクを評価した。
例 14（比較例）
例１の組成でポリビニルメチルエーテルの代り
に市販の流動パラフイン（ポリエチレン等）を加
え、以下例１と同様の手順で処理して、磁気デイ
スクを作成した。そして、その特性を評価した。
以上の実験で得られた結果を下記の表にまとめ
て示す。[Table] Example 11 (Comparative Example) The same composition as in Example 1, but the primary baking conditions were 250°C for 1 hour (normal complete hardening treatment conditions) instead of 170°C for 1 hour, and Example 1 is as follows. A magnetic disk was created using the same procedure as above, and its characteristics were evaluated. Example 12 (Comparative Example) The same composition as in Example 1 was kneaded, applied, and
After primary baking and alcohol immersion, processing such as coating film polishing and surface treatment was immediately performed without performing secondary baking to produce a magnetic disk.
Then, the characteristics of the magnetic disk were evaluated. Example 13 (Comparative Example) After kneading, coating, primary baking, alcohol immersion, and polishing the coating using the same procedure as in Example 12, secondary baking was performed, and processing such as surface treatment was performed, and the magnetic disk was evaluated. Example 14 (Comparative Example) A magnetic disk was prepared by using the composition of Example 1, adding commercially available liquid paraffin (polyethylene, etc.) instead of polyvinyl methyl ether, and following the same procedure as in Example 1. Then, its characteristics were evaluated. The results obtained in the above experiments are summarized in the table below.
【表】
止した。
表から、本発明の実施例（例１〜例９）では、
熱硬化性樹脂だけを用いるもの（例10）に較べ
て、潤滑剤の含漬可能量が大幅に増加し、その結
果、磁性塗膜の機械的強度（CSS強度）も大幅に
改良され、しかも、信号エラー数はほとんど変わ
らないことが見られる。１次焼付けの温度が高い
と（例11）、潤滑剤含浸可能量の増加が非常に少
ない。２次焼付けを行なわないと（例12）、磁性
塗膜の機械的強度が低下し、信号エラー数も増加
している。２次焼付けを研摩後に行なうと（例
13）、強度はでるが、加工傷によりエラーが増加
したものが回復しない。流動パラフインで孔を形
成した場合には（例14）、信号エラー数が大きく
増加している。
例 15
例１において熱硬化性樹脂として
エポキシ樹脂 17.5重量部
フエノール樹脂 7.0重量部
アクリル樹脂 10.5重量部
そして熱可塑性樹脂として
ポリビニルメチルエーテル樹脂（分子量３〜
５万） 10.0重量部
を用いて例１同様に混練し、塗布、１次焼付け
（170℃、１時間）した後、この例では塗膜を30〜
60分間30〜50℃の温水に浸漬して熱可塑性樹脂
（ポリビニルメチルエーテル樹脂）を抽出した。
温水でなく水でもよいが、水を用いると抽出に時
間がかかる。それから例１同様に、250℃で１時
間再硬化（２次焼付け）し、研摩、潤滑剤塗布等
を行なつた。
この磁気デイスクを例１同様の手順で特性の評
価を行なつたところ、潤滑剤相対含浸量1.0、
CSS強度10万回以上、信号エラー数20であつた。
例 16
例15においてポリビニルメチルエーテルをポリ
エチレングリコールにおきかえると、相対含浸量
とCSS強度は同様に向上した。しかし、水への浸
漬時間が２時間必要であり、かつ信号エラー数が
60〜80個に増えた。そこで信号エラー数を減らす
べく１次焼付け温度を下げたところ、信号エラー
数は減つたが潤滑剤の相対含浸量が0.6に低下し
た。従つて、ポリエチレングリコールの効果はポ
リビニルアルコールよりも少し劣つている。
発明の効果
以上の説明から明らかなように、本発明に依
り、より多くの潤滑剤が含浸されて機械的強度が
改良されかつ信号エラーが少ない磁気記録媒体が
提供される。[Table] Stopped.
From the table, in the examples of the present invention (Example 1 to Example 9),
Compared to the case where only thermosetting resin is used (Example 10), the amount of lubricant that can be impregnated is significantly increased, and as a result, the mechanical strength (CSS strength) of the magnetic coating is also greatly improved. , it can be seen that the number of signal errors remains almost unchanged. When the temperature of the primary baking is high (Example 11), the increase in the amount of lubricant that can be impregnated is very small. Without secondary baking (Example 12), the mechanical strength of the magnetic coating decreased and the number of signal errors increased. If secondary baking is performed after polishing (e.g.
13) Although it is strong, it does not recover from increased errors due to processing scratches. When holes were formed using liquid paraffin (Example 14), the number of signal errors increased significantly. Example 15 In Example 1, the thermosetting resins were: 17.5 parts by weight of epoxy resin, 7.0 parts by weight of phenolic resin, 10.5 parts by weight of acrylic resin, and polyvinyl methyl ether resin (molecular weight 3~
50,000 parts by weight) was kneaded in the same manner as in Example 1, coated, and first baked (170°C, 1 hour).
The thermoplastic resin (polyvinyl methyl ether resin) was extracted by immersing it in hot water at 30-50°C for 60 minutes.
You can use water instead of hot water, but using water will take longer to extract. Then, in the same manner as in Example 1, it was rehardened (secondary baking) at 250°C for 1 hour, polished, and coated with lubricant. The characteristics of this magnetic disk were evaluated in the same manner as in Example 1, and the relative lubricant impregnation amount was 1.0.
The CSS strength was over 100,000 times and the number of signal errors was 20. Example 16 When polyvinyl methyl ether was replaced with polyethylene glycol in Example 15, the relative pick-up and CSS strength were similarly improved. However, it requires two hours of immersion in water, and the number of signal errors is low.
The number has increased to 60-80. Therefore, when the primary baking temperature was lowered to reduce the number of signal errors, the number of signal errors decreased, but the relative amount of lubricant impregnation decreased to 0.6. Therefore, polyethylene glycol is slightly less effective than polyvinyl alcohol. Effects of the Invention As is clear from the above description, the present invention provides a magnetic recording medium that is impregnated with more lubricant, has improved mechanical strength, and has fewer signal errors.
添付図面は第一次硬化温度に関する潤滑油含浸
性を表わすグラフである。
The accompanying drawing is a graph representing lubricant impregnation with respect to primary curing temperature.
Claims (1)
磁性塗膜を有する磁気記録媒体の製造方法であつ
て、 磁性粉、熱硬化性樹脂、および該熱硬化性樹脂
と相溶性のある熱可塑性樹脂を含む磁性塗料組成
物を作成し；基体上に該磁性塗料組成物を塗布し
て磁性塗膜を形成し；該磁性塗膜を塗布した該基
体を一次焼付して該磁性塗膜を不完全に硬化さ
せ；溶媒を用いて該不完全硬化磁性塗膜から前記
熱可塑性樹脂を抽出除去し；該磁性塗膜を有する
該基体を二次焼付して該磁性塗膜を完全に硬化さ
せ；該完全硬化磁性塗膜を表面仕上げ処理し；そ
して、該完全硬化磁性塗膜に潤滑剤を含浸する工
程を含むことを特徴とする方法。[Scope of Claims] 1. A method for producing a magnetic recording medium having a magnetic coating film in which magnetic powder is bound with a thermosetting resin binder, comprising: magnetic powder, thermosetting resin, and compatibility with the thermosetting resin. A magnetic coating composition containing a certain thermoplastic resin is prepared; the magnetic coating composition is applied onto a substrate to form a magnetic coating film; the substrate coated with the magnetic coating film is primarily baked to form the magnetic coating composition; incompletely curing the coating film; extracting and removing the thermoplastic resin from the incompletely cured magnetic coating film using a solvent; and secondary baking the substrate having the magnetic coating film to completely cure the magnetic coating film. A method comprising: curing the fully cured magnetic coating; surface finishing the fully cured magnetic coating; and impregnating the fully cured magnetic coating with a lubricant.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5724184A JPS60202541A (en) | 1984-03-27 | 1984-03-27 | Manufacture of magnetic recording medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5724184A JPS60202541A (en) | 1984-03-27 | 1984-03-27 | Manufacture of magnetic recording medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60202541A JPS60202541A (en) | 1985-10-14 |
| JPH0250530B2 true JPH0250530B2 (en) | 1990-11-02 |
Family
ID=13050033
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5724184A Granted JPS60202541A (en) | 1984-03-27 | 1984-03-27 | Manufacture of magnetic recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60202541A (en) |
-
1984
- 1984-03-27 JP JP5724184A patent/JPS60202541A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60202541A (en) | 1985-10-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| DE2255028A1 (en) | METHOD OF MANUFACTURING MAGNETIC RECORDING DISCS | |
| JPH0250530B2 (en) | ||
| JPS5837612B2 (en) | Liquid composition forming thermosetting film | |
| US4985295A (en) | Magnetic recording medium and method for producing the same | |
| US4046932A (en) | Magnetic recording discs | |
| DE1804393A1 (en) | Process for the production of magnetic recording media | |
| JPH0256728B2 (en) | ||
| DE3727197C2 (en) | Magnetic recording medium and method for its production | |
| JPH0224836A (en) | Production of magnetic recording medium | |
| JPS63181121A (en) | Production of magnetic recording medium | |
| US4603080A (en) | Magnetic recording media comprising fine particles of organosilica gel in the magnetic recording layer | |
| EP0191323B1 (en) | Magnetic recording disk and method of fabricating same | |
| JPH022220B2 (en) | ||
| JPH02260124A (en) | Magnetic recording medium | |
| JPS63193325A (en) | Magnetic recording medium and its production | |
| JPS6132218A (en) | Manufacture of magnetic disk | |
| JPS5987623A (en) | Magnetic storage body | |
| JP2959802B2 (en) | Method of manufacturing continuous magnetic film type magnetic recording medium | |
| JPS6156561B2 (en) | ||
| KR840000873B1 (en) | Magnetic recording medium | |
| KR0148754B1 (en) | Method of manufacturing magnetic recording medium | |
| JPH0258688B2 (en) | ||
| DE2312848A1 (en) | Ground magnetic recording discs contg. corundum - for smoother travel of flying heads and fewer recording dropouts | |
| JP3272789B2 (en) | Method of manufacturing magnetic disk and method of manufacturing optical disk | |
| JPS5925284B2 (en) | Method for manufacturing magnetic disk recording media |