JPH02208819A - Magnetic recording medium - Google Patents
Magnetic recording mediumInfo
- Publication number
- JPH02208819A JPH02208819A JP3089689A JP3089689A JPH02208819A JP H02208819 A JPH02208819 A JP H02208819A JP 3089689 A JP3089689 A JP 3089689A JP 3089689 A JP3089689 A JP 3089689A JP H02208819 A JPH02208819 A JP H02208819A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic recording
- substrate
- recording medium
- magnetic
- synthetic resin
- 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.)
- Pending
Links
- 239000000758 substrate Substances 0.000 claims abstract description 71
- 229920001187 thermosetting polymer Polymers 0.000 claims abstract description 41
- 229920003002 synthetic resin Polymers 0.000 claims abstract description 35
- 239000000057 synthetic resin Substances 0.000 claims abstract description 35
- 229920005989 resin Polymers 0.000 claims abstract description 24
- 239000011347 resin Substances 0.000 claims abstract description 24
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims abstract description 20
- 239000006249 magnetic particle Substances 0.000 claims description 19
- 239000000696 magnetic material Substances 0.000 claims 1
- 239000002245 particle Substances 0.000 abstract description 11
- 239000000428 dust Substances 0.000 abstract description 3
- 238000005299 abrasion Methods 0.000 abstract 2
- 238000004924 electrostatic deposition Methods 0.000 abstract 1
- 239000010410 layer Substances 0.000 description 62
- 239000011248 coating agent Substances 0.000 description 27
- 238000000576 coating method Methods 0.000 description 27
- 239000010408 film Substances 0.000 description 25
- 238000000034 method Methods 0.000 description 14
- 230000007547 defect Effects 0.000 description 12
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 11
- 229910052799 carbon Inorganic materials 0.000 description 11
- 230000003746 surface roughness Effects 0.000 description 8
- 230000000694 effects Effects 0.000 description 7
- 238000005516 engineering process Methods 0.000 description 7
- 239000000203 mixture Substances 0.000 description 7
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 6
- 239000003973 paint Substances 0.000 description 6
- 229910000838 Al alloy Inorganic materials 0.000 description 5
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 5
- 230000005611 electricity Effects 0.000 description 5
- 239000003822 epoxy resin Substances 0.000 description 5
- 229920000647 polyepoxide Polymers 0.000 description 5
- 230000003068 static effect Effects 0.000 description 5
- 229910000531 Co alloy Inorganic materials 0.000 description 4
- JHIVVAPYMSGYDF-UHFFFAOYSA-N cyclohexanone Chemical compound O=C1CCCCC1 JHIVVAPYMSGYDF-UHFFFAOYSA-N 0.000 description 4
- 238000005461 lubrication Methods 0.000 description 4
- 239000004697 Polyetherimide Substances 0.000 description 3
- 229910045601 alloy Inorganic materials 0.000 description 3
- 239000000956 alloy Substances 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 238000010304 firing Methods 0.000 description 3
- 238000001746 injection moulding Methods 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 239000005011 phenolic resin Substances 0.000 description 3
- 238000005498 polishing Methods 0.000 description 3
- 229920001601 polyetherimide Polymers 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- 239000002270 dispersing agent Substances 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 230000001050 lubricating effect Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 230000002093 peripheral effect Effects 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 239000000377 silicon dioxide Substances 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- XOLBLPGZBRYERU-UHFFFAOYSA-N tin dioxide Chemical compound O=[Sn]=O XOLBLPGZBRYERU-UHFFFAOYSA-N 0.000 description 2
- KXGFMDJXCMQABM-UHFFFAOYSA-N 2-methoxy-6-methylphenol Chemical compound [CH]OC1=CC=CC([CH])=C1O KXGFMDJXCMQABM-UHFFFAOYSA-N 0.000 description 1
- -1 Ag and Cu Chemical class 0.000 description 1
- 229920000049 Carbon (fiber) Polymers 0.000 description 1
- 229910020676 Co—N Inorganic materials 0.000 description 1
- 108091081050 CrcZ Proteins 0.000 description 1
- 229920000877 Melamine resin Polymers 0.000 description 1
- 229910000861 Mg alloy Inorganic materials 0.000 description 1
- 239000004952 Polyamide Substances 0.000 description 1
- 239000004695 Polyether sulfone Substances 0.000 description 1
- 239000004642 Polyimide Substances 0.000 description 1
- 239000004734 Polyphenylene sulfide Substances 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- 229920001807 Urea-formaldehyde Polymers 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 229910001566 austenite Inorganic materials 0.000 description 1
- 239000011324 bead Substances 0.000 description 1
- QHIWVLPBUQWDMQ-UHFFFAOYSA-N butyl prop-2-enoate;methyl 2-methylprop-2-enoate;prop-2-enoic acid Chemical compound OC(=O)C=C.COC(=O)C(C)=C.CCCCOC(=O)C=C QHIWVLPBUQWDMQ-UHFFFAOYSA-N 0.000 description 1
- 239000004917 carbon fiber Substances 0.000 description 1
- OKTJSMMVPCPJKN-YPZZEJLDSA-N carbon-10 atom Chemical group [10C] OKTJSMMVPCPJKN-YPZZEJLDSA-N 0.000 description 1
- 229910001567 cementite Inorganic materials 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- NJLLQSBAHIKGKF-UHFFFAOYSA-N dipotassium dioxido(oxo)titanium Chemical compound [K+].[K+].[O-][Ti]([O-])=O NJLLQSBAHIKGKF-UHFFFAOYSA-N 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 239000003365 glass fiber Substances 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 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 1
- 230000001771 impaired effect Effects 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 239000006247 magnetic powder Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 150000001247 metal acetylides Chemical class 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- WHOPEPSOPUIRQQ-UHFFFAOYSA-N oxoaluminum Chemical compound O1[Al]O[Al]1 WHOPEPSOPUIRQQ-UHFFFAOYSA-N 0.000 description 1
- 229920001568 phenolic resin Polymers 0.000 description 1
- 229920002647 polyamide Polymers 0.000 description 1
- 229920006393 polyether sulfone Polymers 0.000 description 1
- 229920001721 polyimide Polymers 0.000 description 1
- 229920000069 polyphenylene sulfide Polymers 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 239000011241 protective layer Substances 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 238000004528 spin coating Methods 0.000 description 1
- 238000009987 spinning Methods 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
本発明は、磁気記録媒体に係り、特に、合成樹脂製の基
板を用いたＣ３Ｓ特性に優れた磁気記録媒体に関する。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a magnetic recording medium, and particularly to a magnetic recording medium with excellent C3S characteristics using a synthetic resin substrate.
［従来の技術］
従来、磁気記録媒体としては、アルミ合金製基板の表面
をアルマイト処理または金属メツキし、さらにその表面
を鏡面研磨仕上した基板を用いたものが知られている。[Prior Art] Conventionally, as a magnetic recording medium, one using an aluminum alloy substrate whose surface is alumite-treated or metal-plated and whose surface is mirror-polished is known.
しかるに、近時、磁気記録媒体にも軽量化及び加工容易
性が強く要請されており、かかる要請に基づき、アルミ
合金製基板よりも軽量で加工が容易な合成樹脂製の基板
が提案されている。しかし、合成樹脂製の基板はアルミ
合金製基板に比べ硬度が十分ではなく、そのため、合成
樹脂製の基板を用いた磁気記録媒体の耐ＣＳＳ特性は不
十分であり、ヘッドクラッシュを生じるという問題があ
る。また、合成樹脂製の基板は一服に絶縁性であり、ハ
ンドリング及び磁気記録層形成の際に基板表面に静電気
が帯電し、異物付着を起こしやすく、信号欠陥も多い。However, in recent years, there has been a strong demand for magnetic recording media to be lighter and easier to process, and based on these demands, synthetic resin substrates, which are lighter and easier to process than aluminum alloy substrates, have been proposed. . However, synthetic resin substrates do not have sufficient hardness compared to aluminum alloy substrates, and as a result, magnetic recording media using synthetic resin substrates have insufficient CSS resistance, leading to the problem of head crashes. be. In addition, synthetic resin substrates are completely insulative, and static electricity is charged on the substrate surface during handling and formation of a magnetic recording layer, which tends to cause foreign matter to adhere and cause many signal defects.
ところで、基板の硬度を高めることにより、磁気記録媒
体のＣＳＳ特性を向上させ、その信頼性を高める技術と
しては、アルミ合金製基板を用いたものについてではあ
るが、次の技術が知られている。By the way, as a technique for improving the CSS characteristics of a magnetic recording medium and increasing its reliability by increasing the hardness of the substrate, the following technique is known, although it uses an aluminum alloy substrate. .
■特開昭６１−２３０６１８号公報に開示された技術
この技術においては、合金基板（Ａｎ−Ｍｇ合金）の上
に、下地層として、シリカ（粒径２５０人）とエポキシ
樹脂とからなるＵＶ硬化膜（０，１μｍ）を設ける。さ
らに、記録層としてスパッタ磁性膜を形成する。この下
地層の効果は、ＣＳＳ時の応力の吸収と微粒子が形成す
る表面の突起によるヘッドに対する摩擦力の低下とであ
り、その結果として磁性膜に傷が入ることを防止してい
る。■Technology disclosed in Japanese Patent Application Laid-Open No. 61-230618 In this technology, a UV-cured base layer consisting of silica (particle size 250) and epoxy resin is placed on an alloy substrate (An-Mg alloy). A membrane (0.1 μm) is provided. Furthermore, a sputtered magnetic film is formed as a recording layer. The effect of this underlayer is to absorb stress during CSS and to reduce the frictional force against the head due to surface protrusions formed by fine particles, thereby preventing scratches on the magnetic film.
■特開昭６２−２５２５２６号公報に開示された技術
この技術は、焼成によりＡｆ１２０ｓまたはｓｉｏ、の
被覆を得る方法である。すなわち、非磁性基板上にＡＪ
２ＣＮＯｘ ）ｓ ２０％メタノール溶液、又は、５ｔ
（ＯＣｓＨｙ）４１５％メタノール溶液をスピンコード
で塗布し、５００℃で１時間焼成し、７μｍ厚のＡｌｌ
２ ｏ、 、または、５Ｌ０２の固化膜を下地層として
形成する。あるいは、Ａｌ２Ｏ２を形成した後、アルゴ
ンビームで表面の粗さＲ、、Ｘで０．０５μｍとした固
化膜とする。これらの下地層上に、磁性層を設け、保護
層を形成する。この磁気記録媒体は、Ｃ５５２００００
回後も磁気記録媒体表面に傷が入らず、かつ、耐食性も
向上している。■Technology disclosed in Japanese Patent Application Laid-Open No. 62-252526 This technology is a method of obtaining Af120s or sio coating by firing. That is, AJ is placed on a non-magnetic substrate.
2CNOx)s 20% methanol solution or 5t
(OCsHy) 415% methanol solution was applied with a spin cord, baked at 500°C for 1 hour, and a 7 μm thick Al
A solidified film of 2 o, or 5L02 is formed as a base layer. Alternatively, after forming Al2O2, a solidified film is formed with a surface roughness R, , X of 0.05 μm using an argon beam. A magnetic layer is provided on these underlayers to form a protective layer. This magnetic recording medium is C5520000
Even after spinning, the surface of the magnetic recording medium is free from scratches, and its corrosion resistance is also improved.
しかし、上記従来技術には次のような問題点が存在する
。However, the above conventional technology has the following problems.
■特開昭６１−２３０６１８号公報に開示された技術
シリカとエポキシ樹脂とからなる下地層は、絶縁体であ
り、かつ、膜厚も０．１μｍと薄い。したがって、基板
には、導電性を持つこと、０．１μｍ程度の下地層でも
十分耐ＣＳＳに効果がある硬度を持つことが要求される
。したがって、この基板は、アルミ合金と限定されてい
るように、合成樹脂製の基板には適応できない。(2) Technology disclosed in Japanese Unexamined Patent Publication No. 61-230618 The base layer made of silica and epoxy resin is an insulator and has a thin film thickness of 0.1 μm. Therefore, the substrate is required to have conductivity and hardness that is sufficiently effective for CSS resistance even with a base layer of about 0.1 μm. Therefore, this substrate cannot be applied to synthetic resin substrates, as it is limited to aluminum alloys.
■特開昭８２−２５２５２６号公報に開示された技術
焼成によりＡｌｌ、０３の被覆を得る方法は、５００℃
という高温下での成膜処理が必要であるため、合成樹脂
製め基板に対しては全く適用することができない。■The method of obtaining All, 03 coating by technical firing disclosed in Japanese Patent Application Laid-Open No. 82-252526 is 500°C.
Since this method requires film formation at high temperatures, it cannot be applied to synthetic resin substrates at all.
また、上記技術における磁気記録媒体のいずれもが、表
面が平坦であり、電磁気特性（特に再生出力、分解能）
において満足すべきものが得られていない。In addition, all of the magnetic recording media in the above technology have flat surfaces and electromagnetic properties (especially reproduction output and resolution).
I have not been able to obtain anything satisfactory.
［発明が解決しようとする課題］
合成樹脂製の基板は、一般に、絶縁性があり、かつ、硬
度が低い。その結果、帯電による異物付着が発生して信
号欠陥を誘発する原因となったり、耐Ｃ８Ｓ性において
硬度不足のためヘッドの損傷を起こすことが問題となっ
ていた。[Problems to be Solved by the Invention] A synthetic resin substrate generally has insulation properties and low hardness. As a result, there have been problems in that foreign matter adhesion due to charging occurs, causing signal defects, and damage to the head occurs due to insufficient hardness in C8S resistance.
本発明は、上記課題を解決し、耐摩耗性、耐擦傷性に優
れ、静電気による塵埃の付着のない、合成樹脂製の基板
を用いた磁気記録媒体を提供することを第１の目的とす
る。The first object of the present invention is to solve the above-mentioned problems and provide a magnetic recording medium using a synthetic resin substrate, which has excellent wear resistance and scratch resistance, and does not attract dust due to static electricity. .
本発明は、軽量かつ安価でＣＳＳ特性に優れ、信頼性に
優れた磁気記録媒体を提供することを第２の目的とする
。A second object of the present invention is to provide a magnetic recording medium that is lightweight, inexpensive, has excellent CSS characteristics, and is highly reliable.
本発明は、高出力、高分解能を有する磁気記録媒体を提
供することを第３の目的とする。A third object of the present invention is to provide a magnetic recording medium having high output and high resolution.
［課題を解決するための手段］
本発明の第１の要旨は、
内周部から外周部に及ぶ半径方向の断面形状が緩やかな
凸部形状となるように成形された合成樹脂製の基板と：
該基板上に形成された、アルミナと比抵抗が１×１０６
Ωｃｍ以下の非磁性粒子とを含有せしめた熱硬化性樹脂
からなる下地層と；
該下地層上に形成された磁性層と；
を有していることを特徴とする磁気記録媒体に存在する
。[Means for Solving the Problems] A first aspect of the present invention is to provide a synthetic resin substrate formed so that the radial cross-sectional shape extending from the inner periphery to the outer periphery has a gentle convex shape. : Alumina formed on the substrate has a specific resistance of 1×106
A magnetic recording medium comprising: an underlayer made of a thermosetting resin containing non-magnetic particles of Ωcm or less; and a magnetic layer formed on the underlayer.
本発明の第２の要旨は、
合成樹脂製の平坦な基板と：
該基板上に、該基板の内周部から外周部に及ぶ半径方向
の断面形状が緩やかな凸部形状となるように形成された
、アルミナと比抵抗が１×１０６Ωｃｍ以下の非磁性粒
子とを含有せしめた熱硬化性樹脂からなる下地層と；
該下地層上に形成された磁性層と；
を有していることを特徴とする磁気記録媒体に存在する
。The second gist of the present invention is to provide: a flat substrate made of synthetic resin; formed on the substrate so that the cross-sectional shape in the radial direction extending from the inner circumference to the outer circumference of the substrate has a gentle convex shape; a base layer made of a thermosetting resin containing alumina and non-magnetic particles having a specific resistance of 1×10 Ωcm or less; a magnetic layer formed on the base layer; Characteristically present in magnetic recording media.
本発明において熱硬化性樹脂は、フェノール樹脂、エポ
キシ樹脂、尿素樹脂、アクリル系反応樹脂、ホルマール
樹脂、メラミン樹脂等が挙げられる。また、これらの混
合物でもかまわない。Examples of thermosetting resins in the present invention include phenol resins, epoxy resins, urea resins, acrylic reaction resins, formal resins, and melamine resins. Also, a mixture of these may be used.
本発明において使用される合成樹脂製の基板としては、
熱硬化性樹脂を熱硬化させるため、耐熱性に優れたポリ
エーテルイミド、ポリアミド、ポリイミド、ポリエーテ
ルサルホン、ポリフェニレンサルファイド等が挙げられ
るが、なかでも、ポリエーテルイミドが好ましい。また
、これらの樹脂にガラス繊維、カーボン繊維、チタン酸
カリウムウィスカー、ガラスピーズ等の充填材を添加し
た複合材料でもかまわない。The synthetic resin substrate used in the present invention includes:
In order to thermoset the thermosetting resin, polyetherimide, polyamide, polyimide, polyether sulfone, polyphenylene sulfide, etc., which have excellent heat resistance, can be used, and among them, polyetherimide is preferable. Alternatively, a composite material in which fillers such as glass fibers, carbon fibers, potassium titanate whiskers, glass beads, etc. are added to these resins may be used.
本発明の第２の要旨においては、この基板として平坦な
ものを使用する。一方、本発明の第１の要旨においては
、内周部から外周部に及ぶ半径方向の断面形状が緩やか
な凸部形状となるように成形された基板（第１図）を使
用する。このような凸部をもたせるためには、かかる形
状に対応した金型を用いて射出成型すれば容易に作製す
ることができる。なお、射出成型に際しては、中心と外
周部との中央部近傍が最もヒケ量が大きいことを本発明
では、この合成樹脂製の基板上にアルミナと非磁性粒子
とを含有せしめた熱硬化性樹脂からなる熱硬化性塗膜（
下地層）が形成されている。非磁性粒子は、比抵抗が１
×１０６Ωｃｍ以下の非磁性粒子である。In the second aspect of the present invention, a flat substrate is used as the substrate. On the other hand, in the first aspect of the present invention, a substrate (FIG. 1) is used which is shaped so that the radial cross-sectional shape extending from the inner circumference to the outer circumference has a gentle convex shape. In order to have such a convex portion, it can be easily produced by injection molding using a mold corresponding to such a shape. It should be noted that during injection molding, the amount of sinkage is greatest near the center between the center and the outer periphery.In the present invention, a thermosetting resin containing alumina and non-magnetic particles is used on this synthetic resin substrate. A thermosetting coating film consisting of (
Underlayer) is formed. Non-magnetic particles have a resistivity of 1
They are non-magnetic particles with a diameter of 106 Ωcm or less.
非磁性粒子としては、例えばＳｉＣ，Ｔｉｃ。Examples of non-magnetic particles include SiC and Tic.
ＣｒＣｚ等の炭化物、ＢＮ、５ｉ３Ｎａ 、ＴｉＮ等の
窒化物、ＴｔＢ２．ＺｒＢｚ等のホク化物、ＳｎＯ□等
の酸化物、Ａｇ、Ｃｕ等の金属、カーボン等があげられ
る。これらの中では、少量でも抵抗の低下が著しい金属
や、安定性に優れる５ｎ０２が好ましく、表面粗さの調
整及び熱硬化性樹脂中での分散が行いやすいという点で
はカーボンが好ましい。また、後に作用として詳述する
熱硬化性塗膜の帯電防止効果は、熱硬化性塗膜の表面抵
抗が１×１０６〜１０１０Ω／口程度で効果が現われる
。したがって、非磁性粒子の比抵抗は１ ｘ １０１１
Ωｃｍ以下であれば、十分に満足できる。Carbides such as CrCz, nitrides such as BN, 5i3Na, TiN, TtB2. Examples include holides such as ZrBz, oxides such as SnO□, metals such as Ag and Cu, and carbon. Among these, metals whose resistance decreases significantly even in small amounts and 5n02 which is excellent in stability are preferable, and carbon is preferable because it is easy to adjust the surface roughness and disperse it in the thermosetting resin. Further, the antistatic effect of the thermosetting coating film, which will be described in detail later as an effect, becomes effective when the surface resistance of the thermosetting coating film is about 1×10 6 to 10 10 Ω/mouth. Therefore, the resistivity of non-magnetic particles is 1 x 1011
If it is Ωcm or less, it is fully satisfactory.
熱硬化性塗膜を形成するには、まず非磁性粒子と熱硬化
性樹脂とを混練し、この非磁性粒子を含有せしめた熱硬
化性樹脂を合成樹脂製の基板上に塗布し、熱硬化処理を
施せばよい。アルミナと非磁性粒子を含有せしめた熱硬
化性樹脂を塗布する方法こしては、例えばスピンコード
法を用しする。To form a thermosetting coating, first, non-magnetic particles and a thermosetting resin are kneaded, the thermosetting resin containing the non-magnetic particles is applied onto a synthetic resin substrate, and then thermosetting. All you have to do is process it. The method of applying the thermosetting resin containing alumina and nonmagnetic particles is, for example, a spin cord method.
このアルミナと非磁性粒子と熱硬化性樹脂からなる熱硬
化性塗膜の厚みは、硬度及び帯電防止効果を十分に満足
するためには、０．５μｍ以上が望ましい。また、適度
な表面の粗さ（Ｒａ５０〜１００人程度）を与えるため
には、アルミナの平均粒径は熱硬化性塗膜の厚み以下が
望ましい。例えば、アルミナの平均粒径を０．５〜１．
０μｍとすれば表面の粗さがＲａ５０〜１００人程度と
なり、ヘッドと磁気記録媒体の間での吸着防止を良好に
行える。アルミナは球状でも破砕状でもかまわない。The thickness of the thermosetting coating film made of alumina, nonmagnetic particles, and thermosetting resin is desirably 0.5 μm or more in order to sufficiently satisfy the hardness and antistatic effect. Further, in order to provide a suitable surface roughness (Ra of about 50 to 100), the average particle size of alumina is desirably equal to or less than the thickness of the thermosetting coating film. For example, the average particle size of alumina is 0.5 to 1.
If it is 0 μm, the surface roughness will be Ra of about 50 to 100, and adhesion between the head and the magnetic recording medium can be effectively prevented. Alumina may be spherical or crushed.
本発明の第２の要旨においては、上記下地層を内周部か
ら外周部に及ぶ半径方向の断面形状が緩やかな凸部形状
となるように形成する。In the second aspect of the present invention, the base layer is formed so that the cross-sectional shape in the radial direction extending from the inner peripheral part to the outer peripheral part has a gentle convex shape.
かかる下地層は、まず、基板に熱硬化性樹脂を平坦に塗
布し、該樹脂を硬化後、基板を回転させながら、加圧部
材により研磨テープを基板表面に押し当て、基板の内周
部から外周部に及ぶ半径方向の断面形状を緩やかな凸部
形状になるように表面研磨すればよい。To form such a base layer, first, a thermosetting resin is applied flatly to the substrate, and after the resin is cured, a polishing tape is pressed against the surface of the substrate using a pressure member while rotating the substrate, and a polishing tape is applied from the inner periphery of the substrate. The surface may be polished so that the cross-sectional shape in the radial direction extending to the outer periphery becomes a gentle convex shape.
熱硬化性塗膜上の磁気記録層は、記録再生に関与する層
であり、かかる作用を奥するならばいかなるものでもよ
い。例えば、Ｃｏ−Ｃｒ％Ｃｏ−Ｎ ｉ−Ｃｒ、酸化鉄
等でもよいし、磁性粉末（例えば、炭化鉄粉、γ−Ｆｅ
、０３粉等）を樹脂で結合したものでもよい。The magnetic recording layer on the thermosetting coating film is a layer that is involved in recording and reproduction, and any layer may be used as long as it has this function. For example, Co-Cr%Co-N i-Cr, iron oxide, etc. may be used, or magnetic powder (e.g. iron carbide powder, γ-Fe
, 03 powder, etc.) bound with a resin.
［作 用］ 以下に本発明の詳細な説明する。[Work] The present invention will be explained in detail below.
本発明では、合成樹脂製の基板に下地層を設け、その下
地層として熱硬化性塗膜を用いている。すなわち、熱硬
化性樹脂塗料を合成樹脂製の基板上に塗布し熱により硬
化させるので、熱硬化性塗膜と合成樹脂製の基板との間
で良好な密着性を得ることができる。さらに、硬化は従
来技術で述べた５００℃での焼成のような高温処理より
もはるかに低い温度で行えるので、合成樹脂製の基板に
過大な熱を加えることなく高硬度な被膜を形成すること
が可能である。In the present invention, a base layer is provided on a synthetic resin substrate, and a thermosetting coating film is used as the base layer. That is, since the thermosetting resin coating is applied onto the synthetic resin substrate and cured by heat, good adhesion can be obtained between the thermosetting coating and the synthetic resin substrate. Furthermore, since curing can be performed at a much lower temperature than the high-temperature treatment such as baking at 500°C as described in the prior art, it is possible to form a highly hard coating without applying excessive heat to the synthetic resin substrate. is possible.
この熱硬化性塗膜にはアルミナが含有されている。これ
により、熱硬化性塗膜を設けた合成樹脂製の基板の硬度
を高めることができる。さらに、このアルミナによって
、磁気記録媒体表面の粗さを調節し、適度な表面の粗さ
（Ｒａ５０〜１００人程度）を得ることができる。表面
の粗さをＲａ５０〜１００λ程度とすれば、ヘッドと磁
気記録媒体との接触面積が小さくなり、よってヘッドと
磁気記録媒体との摩擦係数も小さくなる。これによりヘ
ッドと磁気記録媒体との間での吸着を防止することがで
きる。This thermosetting coating film contains alumina. Thereby, the hardness of the synthetic resin substrate provided with the thermosetting coating can be increased. Furthermore, by using this alumina, the roughness of the surface of the magnetic recording medium can be adjusted to obtain an appropriate surface roughness (Ra about 50 to 100). If the surface roughness is Ra about 50 to 100λ, the contact area between the head and the magnetic recording medium will be small, and the coefficient of friction between the head and the magnetic recording medium will also be small. This can prevent adhesion between the head and the magnetic recording medium.
さらに、本発明では、熱硬化性塗膜の表面電気抵抗値が
１０６〜１０１０Ω／ロ程度以下となるように、熱硬化
性樹脂中に比抵抗ｌＸ１０’Ωｃｍ以下の非磁性粒子を
含有せしめているため、熱硬化性塗膜に導電性が付与さ
れ、磁気記録媒体の帯電が防止される。Furthermore, in the present invention, non-magnetic particles having a specific resistance of 1 x 10' Ωcm or less are contained in the thermosetting resin so that the surface electrical resistance value of the thermosetting coating film is about 106 to 1010 Ω/2 or less. Therefore, conductivity is imparted to the thermosetting coating film, and charging of the magnetic recording medium is prevented.
熱硬化性塗膜の表面抵抗値は、含有せしめる非磁性粒子
の種類、含有量、熱硬化性塗膜内における分布状況等の
条件によって変化するので、１０”〜１０１０Ω／口程
度以下とするには、予めこれらの条件と電気抵抗値との
関係を求めておき適宜決定すればよい。The surface resistance value of a thermosetting coating film varies depending on conditions such as the type of non-magnetic particles contained, the content, and the distribution within the thermosetting coating film, so it should be approximately 10" to 1010Ω/mouth or less. may be determined appropriately by determining the relationship between these conditions and the electrical resistance value in advance.
本発明では以上に述べたような熱硬化性塗膜により、合
成樹脂製の基板に対して充分な硬度を付与することがで
き、よってＣ５Ｓ耐久性が向上する。熱硬化性塗膜であ
るため合成樹脂製の基板との密着性もよい、また、合成
樹脂製の基板の帯電を防止するので、磁気記録層が形成
される面上への異物の付着を誘発しないため、形成され
た磁気記録層の信号欠陥が大幅に減少する。さらに、製
造された磁気記録媒体の表面に適度な粗さを与えること
で、使用時のヘッドと記録媒体との間の吸着が防止でき
る。In the present invention, the above-described thermosetting coating film can impart sufficient hardness to the synthetic resin substrate, thereby improving C5S durability. Since it is a thermosetting coating, it has good adhesion to synthetic resin substrates, and also prevents static electricity on synthetic resin substrates, which induces the adhesion of foreign matter to the surface on which the magnetic recording layer is formed. Therefore, signal defects in the formed magnetic recording layer are significantly reduced. Furthermore, by providing the surface of the manufactured magnetic recording medium with an appropriate roughness, it is possible to prevent adhesion between the head and the recording medium during use.
さらに、本発明では、内周部から外周部に及ぶ半径方向
の断面形状が緩やかな凸部形状をしているため、第１図
に示すように、磁気記録媒体２２の浮上量は、ベツドギ
ャップ部１０（浮上量Ｈ１）がスライダ一部２１（浮上
量Ｈ２）よりも小さくなる。ヘッドギャップ部１０と磁
気記録媒体２２との距離が近い程大きな出力が得られ、
また、分解能も良好になるので、本発明では大出力、高
分解能の磁気記録媒体が得られることとなる。Furthermore, in the present invention, since the radial cross-sectional shape extending from the inner circumference to the outer circumference has a gentle convex shape, the flying height of the magnetic recording medium 22 is smaller than the bed gap, as shown in FIG. The portion 10 (flying height H1) is smaller than the slider portion 21 (flying height H2). The closer the distance between the head gap portion 10 and the magnetic recording medium 22, the greater the output can be obtained.
Furthermore, since the resolution is also improved, the present invention can provide a high-output, high-resolution magnetic recording medium.
［実施例］。[Example].
以下、本発明の具体的な実施例を挙げ、製造工程ととも
にさらに詳細に説明する。Hereinafter, specific examples of the present invention will be given and explained in more detail together with the manufacturing process.
（実施例１）
第２図は本発明の実施例の磁気記録媒体を示す断面図で
あり、第２図において、１は熱硬化性塗膜、２はアルミ
ナ、３は非磁性粒子のＳｎＯ２である。４は合成樹脂製
の基板であり、金型を用いた射出成型により第３図に示
すような形状に成型してこの基板を得た。５はＣｒ層、
６はＣｏ合金層、７はカーボン層、８は潤滑層である。(Example 1) Figure 2 is a cross-sectional view showing a magnetic recording medium according to an example of the present invention. In Figure 2, 1 is a thermosetting coating film, 2 is alumina, and 3 is a non-magnetic particle of SnO2. be. Reference numeral 4 denotes a synthetic resin substrate, which was molded into the shape shown in FIG. 3 by injection molding using a mold. 5 is a Cr layer,
6 is a Co alloy layer, 7 is a carbon layer, and 8 is a lubricating layer.
Ｃｒ層５は下地層、００合、金層６は磁気記録層、カー
ボン層７は保護膜である。The Cr layer 5 is a base layer, the 00 alloy layer, the gold layer 6 a magnetic recording layer, and the carbon layer 7 a protective film.
熱硬化性塗膜（下地層）１を形成する塗料の組成は、以
下の通りである。The composition of the coating material forming the thermosetting coating film (base layer) 1 is as follows.
アルミナ ５０重量部Ｓ ｎ ０２
５０重量部エポキシ樹脂
２５重量部フェノール樹脂 ２５皿量部シ
クロへキサノン ５００重量部分散剤
１０重量部以上の組成でサンドミル型分散機
により１０時間分散を行った後、濾過し、塗料を作製し
た。この塗料をスピンコード法を用いて、ポリエーテル
イミド樹脂製の５．２５インチ基板４上に、硬化後の膜
厚が５μｍになるように塗布した。Alumina 50 parts by weight S n 02
50 parts by weight epoxy resin
25 parts by weight phenolic resin 25 parts by weight cyclohexanone 500 parts by weight Dispersant
After dispersing with a composition of 10 parts by weight or more using a sand mill type disperser for 10 hours, the mixture was filtered to prepare a paint. This paint was applied onto a 5.25-inch substrate 4 made of polyetherimide resin using a spin code method so that the film thickness after curing would be 5 μm.
膜厚の調整は、スピンコーティングの振り切りの回数及
び重ね塗り等で行った。続いてオーブンで２００℃２時
間の熱処理を施して硬化させ、表面の粗さＲａｌＯＯ人
の熱硬化性塗膜１を得た。The film thickness was adjusted by changing the number of times the spin coating was spun off, overcoating, etc. Subsequently, it was cured by heat treatment at 200° C. for 2 hours in an oven to obtain a thermosetting coating film 1 with a surface roughness of RalOO.
その後、ＤＣマグネトロン方式によるスパッタリングで
２０００人のＣｒ層５．８００人のＣ。After that, 2000 Cr layers and 5800 Cr layers were formed by sputtering using a DC magnetron method.
合金層６．３００人のカーボン層７を形成した。An alloy layer 6.300 carbon layer 7 was formed.
さらに潤滑処理を施し潤滑層８を形成し、本発明の実施
例である磁気記録媒体を得た。Further, a lubrication treatment was performed to form a lubrication layer 8, thereby obtaining a magnetic recording medium as an example of the present invention.
上記の熱硬化性塗膜１の厚さ５μｍの磁気記録媒体の他
に、熱硬化性塗膜１の厚さ０．３μｍ、０．５μｍ、１
μｍの磁気記録媒体を作成し、厚さの小さいものから順
に試料Ｎｏ、１〜４（実施例）とした。また、試料Ｎｏ
、５（比較例）として下地層を有しない磁気記録媒体を
、試料Ｎｏ、６（比較例）として平坦な基板上に平坦な
下地層を形成したものを作製した。下地層１の厚さ、基
板形状以外の条件は全て同じである。In addition to the above magnetic recording medium having a thermosetting coating 1 having a thickness of 5 μm, the thermosetting coating 1 having a thickness of 0.3 μm, 0.5 μm, 1
Magnetic recording media with a thickness of μm were prepared and designated as Sample Nos. 1 to 4 (Examples) in descending order of thickness. Also, sample No.
A magnetic recording medium without an underlayer was prepared as Sample No. 5 (Comparative Example), and a magnetic recording medium having a flat underlayer formed on a flat substrate was prepared as Sample No. 6 (Comparative Example). All conditions other than the thickness of the base layer 1 and the shape of the substrate are the same.
以上の試料Ｎ×１０６１〜６について、トラック幅２０
μｍ、３３７０タイプヘツドを用い、信号欠陥の測定、
ＣＳＳ試験および電磁気特性（再生出力）の測定を行っ
た。その結果を表１に示す。For the above samples N×1061~6, the track width is 20
Measurement of signal defects using μm, 3370 type head,
A CSS test and measurement of electromagnetic characteristics (reproduction output) were performed. The results are shown in Table 1.
＊ 再生比カニＲ＝２４ｍｍ、２．５ＭＨｚ＊＊ 表面
観察二〇・・・傷なし、Δ・・・傷発生、Ｘ・・・クラ
・ンシュ■信号欠陥
表１に示すように、下地層を有しない試料Ｎｏ、５の磁
気記録媒体は、ハンドリング及び磁気記録層形成の際に
発生する基板上の静電気のために、異物を付着しやすく
信号欠陥も多い。これに対して本発明の実施例である試
料Ｎ０２１〜４の磁気記録媒体では信号欠陥が全く見ら
れず、きわめて良好であった。* Reproduction ratio crab R = 24 mm, 2.5 MHz ** Surface observation 20...No scratches, Δ...Flaws occurred, In the magnetic recording medium of Sample No. 5, which does not have the magnetic recording medium, foreign matter tends to adhere to it and there are many signal defects due to static electricity generated on the substrate during handling and formation of the magnetic recording layer. On the other hand, in the magnetic recording media of samples Nos. 021 to 4, which are examples of the present invention, no signal defects were observed at all, and the results were extremely good.
■ＣＳＳ試験
表１に示すように、下地層を有しない試料Ｎｏ、１の磁
気記録媒体は、ＣＳＳ回数２０００回でクラッシュを起
こしたのに対し、本発明の実施例である試料Ｎ０１１〜
４の磁気記録媒体ではいずれも比較例（Ｎｏ、５）の１
０倍以上の耐久性を示した。■CSS Test As shown in Table 1, the magnetic recording medium of Sample No. 1, which does not have an underlayer, crashed after 2000 CSS cycles, whereas Samples No. 1 to 1, which are examples of the present invention,
Comparative example (No. 5) No. 1 is used for magnetic recording media No. 4.
It showed 0 times more durability.
また、下地層の厚みが０．５μｍ以上の試料（Ｎｏ、２
〜４）では、Ｃ５Ｓ回数３００００回での表面観察には
表面に傷は発生していなかった。しかし、下地層の厚さ
が０．３μｍの試料（Ｎｏ、１）では、ＣＳＳ回数３０
０００回での表面観察では傷が発生していた。この結果
から、より良好な硬度を得る上では、下地層の厚みを０
．５μｍ以上とすることが望ましいことがわかる。In addition, samples with a base layer thickness of 0.5 μm or more (No. 2
-4), no scratches were observed on the surface when the surface was observed after 30,000 C5S cycles. However, in the sample (No. 1) with a base layer thickness of 0.3 μm, the number of CSS was 30.
When the surface was observed 000 times, scratches were found. From this result, in order to obtain better hardness, the thickness of the base layer should be reduced to 0.
．． It can be seen that it is desirable that the thickness be 5 μm or more.
■電磁気特性
表１に示すように、基板の断面形状を平坦にした試料Ｎ
００６の磁気記録媒体は、再生出力が０．７０ｍＶであ
るのに対し、本発明の実施例である試料Ｎ０９１〜４の
磁気記録媒体は、いずれも試料Ｎｏ、６よりも２０％近
く高い再生出力を出すことができた。■Electromagnetic properties As shown in Table 1, sample N with a flat cross-sectional shape of the substrate
The magnetic recording medium No. 006 has a reproduction output of 0.70 mV, whereas the magnetic recording media of samples Nos. I was able to get it out.
（実施例２）
次に、非磁性粒子としてカーボンを用いた例を示す、構
成は第２図に示す実施例１の磁気記録媒体と同様であり
、第２図において、３が非磁性粒子のカーボン粒子とな
る。(Example 2) Next, an example in which carbon is used as the non-magnetic particles is shown.The structure is the same as that of the magnetic recording medium of Example 1 shown in FIG. 2, and in FIG. 2, 3 is the non-magnetic particle. It becomes carbon particles.
下地層１を形成する塗料の組成は、以下の通りである。The composition of the paint forming the base layer 1 is as follows.
アルミナ ７５重量部カーボン
１０重量部エポキシ樹脂 ２
５重量部フェノール樹脂 ２５重量部シクロ
へキサノン ４００重量部分散剤
２重量部以上の組成でボールミル型分散機によ
り５時間分散を行った後、濾過し、塗料を作製した。こ
の塗料をスピンコード法を用いて、実施例１と同じ合成
樹脂製の基板４上に塗布した。膜厚の調整は実施例１と
同様に行った。Alumina 75 parts by weight Carbon
10 parts by weight epoxy resin 2
5 parts by weight Phenol resin 25 parts by weight Cyclohexanone 400 parts by weight Dispersant
After dispersing with a composition of 2 parts by weight or more using a ball mill type disperser for 5 hours, the mixture was filtered to prepare a paint. This paint was applied onto the same synthetic resin substrate 4 as in Example 1 using a spin code method. The film thickness was adjusted in the same manner as in Example 1.
続いてオーブンで２００℃１時間の熱処理を施して硬化
させ、表面の粗さＲａｌＯＯ人の下地層１とした。Subsequently, it was cured by heat treatment at 200° C. for 1 hour in an oven to obtain a base layer 1 with a surface roughness of RalOO.
その後、実施例１と同様にＤＣマグネトロン方式により
２０００人のＣｒ層５．８００人のＣＯ合金層６．３０
０人のカーボン層７を形成し、さらに潤滑処理を施し潤
滑層８を形成した。Thereafter, as in Example 1, 2000 Cr layers, 5800 CO alloy layers, and 630 CO alloy layers were formed using the DC magnetron method.
A carbon layer 7 was formed on the carbon layer 7, and a lubrication treatment was further performed to form a lubrication layer 8.
下地層１の厚さは０．３μｍ、０．６μｍ、１μｍ、２
μｍの４種類を作製し、順に試料Ｎｏ。The thickness of the base layer 1 is 0.3 μm, 0.6 μm, 1 μm, 2
Four types of μm were prepared, and sample numbers were selected in order.
７〜１０としとした。また、比較例として、下地層を有
しない磁気記録媒体を作製し試料Ｎｏ。It was set as 7 to 10. In addition, as a comparative example, a magnetic recording medium without an underlayer was prepared as sample No.
１１とし、他の比較例として平坦な基板上に平坦な下地
層を形成して作製した磁気記録媒体を試料Ｎｏ、１２と
した。下地層１の厚さ、基板形状以外の条件は全て同じ
である。Sample No. 11 was used as another comparative example, and magnetic recording media prepared by forming a flat underlayer on a flat substrate were used as Sample No. 12. All conditions other than the thickness of the base layer 1 and the shape of the substrate are the same.
以上の試料Ｎｏ、７〜１２について、トラック幅２０μ
ｍ３３７０タイプヘツドで信号欠陥の測定及びＣＳＳ試
験を行った結果を表２に示す。For the above samples No. 7 to 12, the track width is 20μ
Table 2 shows the results of signal defect measurements and CSS tests performed on the m3370 type head.
表２
＊ 再生出カニＲ＝２４ｍｍ、２．５ＭＨｚ＊＊ 表面
観察：Ｏ・・・傷なし、Δ・・・傷発生、×・・・クラ
ッシュ■信号欠陥
表２に示すように、下地層を有しない試料Ｎｏ、１１の
磁気記録媒体では信号欠陥が多いのに対して、本発明の
実施例である試料Ｎｏ。Table 2 * Reproduction crab R = 24 mm, 2.5 MHz ** Surface observation: O...No scratches, Δ...Flaws occurred, ×...Crash ■Signal defects As shown in Table 2, the base layer was Sample No. 11, which does not have the magnetic recording medium, has many signal defects, whereas sample No. 11, which is an example of the present invention, has many signal defects.
７〜１０の磁気記録媒体では信号欠陥が全く見られず、
きわめて良好であった。No signal defects were observed in magnetic recording media Nos. 7 to 10,
It was extremely good.
■ＣＳＳ試験
表２に示すように、下地層を有しない試料Ｎｏ、１１の
磁気記録媒体はＣＳＳ回数２０００回でクラッシュを起
こしたのに対し、本発明の実施例である試料Ｎｏ、７〜
１０の磁気記録媒体ではいずれも試料Ｎｏ、１１の１０
倍以上の耐久性を示した。このうち、下地層が０．３μ
ｍの試料Ｎｏ、７では、ＣＳＳ回数３００００回で表面
に傷が発生していた。この結果から、より良好な硬度を
得る上では下地層の厚みを０．６μｍ以上とすることが
望ましいといえる。■CSS test As shown in Table 2, the magnetic recording medium of sample No. 11 without an underlayer crashed after 2000 CSS cycles, whereas the magnetic recording medium of samples No. 7 to 7, which are examples of the present invention, crashed after 2000 CSS
For the 10 magnetic recording media, sample No. 11 and 10
It showed more than double the durability. Of these, the base layer is 0.3μ
In sample No. 7 of M, scratches were generated on the surface after 30,000 CSS cycles. From this result, it can be said that in order to obtain better hardness, it is desirable that the thickness of the underlayer be 0.6 μm or more.
■電磁気特性
表２に示すように、基板の断面形状を平坦にした試料Ｎ
ｏ、１２の磁気記録媒体は、再生出力が０．７０ｍＶで
あるのに対し、本発明の実施例である試料Ｎ０１７〜１
０の磁気記録媒体は、いずれも試料Ｎｏ、１２よりも２
０％近く高い再生出力を出すことができた。■Electromagnetic properties As shown in Table 2, sample N with a flat cross-sectional shape of the substrate
The magnetic recording medium No. 12 has a reproduction output of 0.70 mV, whereas the magnetic recording medium No. 12 has a reproduction output of 0.70 mV, whereas the magnetic recording medium No.
Both sample No. 2 and No. 1 magnetic recording media have a
I was able to output nearly 0% high playback output.
（実施例３）
本例では、基板として平坦な基板を使用し、下地層形成
後、テープ研磨装置を用いて、研磨テープ（研磨粒子：
白色溶融アルミナ、平均粒度３μｍ）にて下地層の研磨
を行い、全体が内周部から外周部に及ぶ半径方向の断面
形状が緩やかな凸部形状となるようにした。その後、磁
性層を形成し、磁気記録媒体を作製した。(Example 3) In this example, a flat substrate is used as the substrate, and after forming the base layer, a polishing tape (abrasive particles:
The base layer was polished with white fused alumina (average particle size: 3 μm) so that the entire cross-section in the radial direction from the inner circumference to the outer circumference had a gentle convex shape. Thereafter, a magnetic layer was formed to produce a magnetic recording medium.
他の点は実施例１と同様とした。The other points were the same as in Example 1.
本例においても実施例１と同様の良好な結果が得られた
。In this example as well, good results similar to those in Example 1 were obtained.
（実施例４）
実施例３と同様に磁気記録媒体を作製した。ただ、本例
では、下地層として実施例２で使用したものを使用した
。(Example 4) A magnetic recording medium was produced in the same manner as in Example 3. However, in this example, the underlayer used in Example 2 was used.
本例においても実施例２と同様の良好な結果が得られた
。In this example as well, good results similar to those in Example 2 were obtained.
［発明の効果］ 本発明は、次に述べる諸々の効果を有する。[Effect of the invention] The present invention has various effects described below.
■下地層は塗料の状態で塗布した後に硬化させて形成す
るので、合成樹脂製の基板との密着性に優れ、平面性も
良好である。また、焼成の場合とは異なり、合成樹脂製
の基板に対して過大な熱を加えることなく高硬度を付与
することができるため、変形が極めて少なく平面性が損
なわれることがない。これにより、耐摩耗性、耐擦傷性
に優れ、かつＣＳＳ特性に優れた、合成樹脂製の基板を
用いた磁気記録媒体を実現することが可能となる。(2) Since the base layer is formed by applying it as a paint and then curing it, it has excellent adhesion to the synthetic resin substrate and has good flatness. Further, unlike in the case of firing, high hardness can be imparted to the synthetic resin substrate without applying excessive heat, so deformation is extremely small and flatness is not impaired. This makes it possible to realize a magnetic recording medium using a synthetic resin substrate that has excellent wear resistance, scratch resistance, and CSS characteristics.
■磁気記録媒体の表面に適度な粗さを付与でき、よって
ヘッドとの吸着を防止できるｌｉｎ気記録媒体を提供で
きる。(2) Appropriate roughness can be imparted to the surface of the magnetic recording medium, thereby providing a linear recording medium that can prevent adhesion to the head.
■下地層に比抵抗が６Ｘ１０６Ω・ｃｍ無機物の非磁性
粒子を含有させることにより導電性が付与されており、
摩擦等による静電気の帯電と、これによる塵埃の吸着、
信号欠陥の発生という、合成樹脂製の基板を用いた場合
に生ずる特有の問題点を解決することができる。■Conductivity is imparted by containing inorganic non-magnetic particles with a specific resistance of 6 x 106 Ωcm in the underlayer.
Static electricity charging due to friction etc. and the adsorption of dust due to this,
It is possible to solve the problem of occurrence of signal defects, which is unique to the use of synthetic resin substrates.
■本発明において、合成樹脂製の基板に対する高硬度の
付与はアルミナによりて行われるので、導電性を付与す
るための非磁性粒子としてはいかなる硬度のものでも使
用可能である。例えば、カーボンのように硬度の低い材
料でも、非磁性粒子として使用できる。(2) In the present invention, since alumina imparts high hardness to the synthetic resin substrate, any hardness can be used as the nonmagnetic particles to impart conductivity. For example, even materials with low hardness such as carbon can be used as non-magnetic particles.
■高い再生出力、高分解能を有する磁気記録媒体を提供
することができる。(2) A magnetic recording medium with high reproduction output and high resolution can be provided.
以上の様々な効果により、合成樹脂製の基板を用いた磁
気記録媒体の信頼性・実用性を低コストかつ容易に高め
ることができる。Due to the various effects described above, the reliability and practicality of a magnetic recording medium using a synthetic resin substrate can be easily improved at low cost.
第１図は、本発明において使用する基板の形状を示す側
面図である。第２図は本発明の実施例の磁気記録媒体を
示す断面図である。第３図は、磁気ヘッドの磁気記録媒
体表面上での浮上状態を示す概念図である。
（符号の説明）
１・・・下地層、２・・・アルミナ、３・・・非磁性粒
子、４・・・合成樹脂製の基板、５・・・Ｃｒ層、６・
・・ＣＯ合金層、７・・・カーボン層、８・・・潤滑層
、１０・・・ベッドギャブ部、１１・・・スライダ一部
、２１・・・ヘッド、２２・・・磁気記録媒体。
第１図
特許出願人 積水化学工業株式会社
代表者 廣 １） 馨
第３図
簾鴨力FIG. 1 is a side view showing the shape of a substrate used in the present invention. FIG. 2 is a sectional view showing a magnetic recording medium according to an embodiment of the present invention. FIG. 3 is a conceptual diagram showing the flying state of the magnetic head above the surface of the magnetic recording medium. (Explanation of symbols) 1... Base layer, 2... Alumina, 3... Non-magnetic particles, 4... Synthetic resin substrate, 5... Cr layer, 6...
. . . CO alloy layer, 7 . . . carbon layer, 8 . . . lubricating layer, 10 . Figure 1 Patent Applicant Sekisui Chemical Co., Ltd. Representative Hiroshi 1) Kaoru Figure 3 Kamo Riki
Claims (2)
やかな凸部形状となるように成形された合成樹脂製の基
板と； 該基板上に形成された、アルミナと比抵抗が１×１０＾
６Ωｃｍ以下の非磁性粒子とを含有せしめた熱硬化性樹
脂からなる下地層と； 該下地層上に形成された磁性層と； を有していることを特徴とする磁気記録媒体。(1) A synthetic resin substrate formed so that the radial cross-sectional shape extending from the inner circumference to the outer circumference has a gentle convex shape; Alumina formed on the substrate and a resistivity of 1 ×10^
A magnetic recording medium comprising: an underlayer made of a thermosetting resin containing non-magnetic particles of 6 Ωcm or less; and a magnetic layer formed on the underlayer.
の断面形状が緩やかな凸部形状となるように形成された
、アルミナと比抵抗が１×１０＾６Ωｃｍ以下の非磁性
粒子とを含有せしめた熱硬化性樹脂からなる下地層と； 該下地層上に形成された磁性層と； を有していることを特徴とする磁気記録媒体。(2) A flat substrate made of synthetic resin, which is formed on the substrate so that the cross-sectional shape in the radial direction from the inner circumference to the outer circumference of the substrate has a gentle convex shape, compared to alumina. A magnetic material comprising: a base layer made of a thermosetting resin containing non-magnetic particles having a resistance of 1×10^6 Ωcm or less; a magnetic layer formed on the base layer; recoding media.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3089689A JPH02208819A (en) | 1989-02-08 | 1989-02-08 | Magnetic recording medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3089689A JPH02208819A (en) | 1989-02-08 | 1989-02-08 | Magnetic recording medium |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH02208819A true JPH02208819A (en) | 1990-08-20 |
Family
ID=12316494
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3089689A Pending JPH02208819A (en) | 1989-02-08 | 1989-02-08 | Magnetic recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH02208819A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1760699A1 (en) * | 2005-08-30 | 2007-03-07 | Konica Minolta Opto, Inc. | Substrate for magnetic information recording medium, and producing method of substrate for magnetic information recording medium |
| US8767350B2 (en) | 2010-12-06 | 2014-07-01 | HGST Netherlands B.V. | Magnetic recording medium having recording regions and separating regions and methods of manufacturing the same |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5764331A (en) * | 1980-10-07 | 1982-04-19 | Nec Corp | Recording disk |
-
1989
- 1989-02-08 JP JP3089689A patent/JPH02208819A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5764331A (en) * | 1980-10-07 | 1982-04-19 | Nec Corp | Recording disk |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1760699A1 (en) * | 2005-08-30 | 2007-03-07 | Konica Minolta Opto, Inc. | Substrate for magnetic information recording medium, and producing method of substrate for magnetic information recording medium |
| US8767350B2 (en) | 2010-12-06 | 2014-07-01 | HGST Netherlands B.V. | Magnetic recording medium having recording regions and separating regions and methods of manufacturing the same |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4389010A (en) | Magnetic tape guide means | |
| US6491798B2 (en) | Magnetic recording medium and magnetic storage apparatus | |
| JPH02208819A (en) | Magnetic recording medium | |
| JPH0746419B2 (en) | Magnetic recording medium | |
| JPH02130718A (en) | Magnetic recording medium | |
| JPH02132630A (en) | Magnetic recording medium | |
| JPH035913A (en) | Magnetic recording medium and its production | |
| JPH02130717A (en) | Magnetic recording medium | |
| JPH0294111A (en) | Magnetic recording medium | |
| JPH035912A (en) | Magnetic recording medium and its production | |
| JPH0388189A (en) | Magnetic disk device | |
| JP2967698B2 (en) | Manufacturing method of magnetic recording medium | |
| KR910001712B1 (en) | Magnetic recording medium | |
| JP3237154B2 (en) | Floating magnetic head | |
| JPH06325342A (en) | Magnetic recording medium | |
| JP2002074643A (en) | Magnetic recording medium | |
| JPH02161609A (en) | Magnetic recording medium | |
| JPH0294112A (en) | Magnetic recording medium | |
| JPH0628097B2 (en) | Base substrate for magnetic disk | |
| JPH0554171B2 (en) | ||
| JPS62275319A (en) | Magnetic recording medium having crack in protective layer | |
| JPH10247316A (en) | Magnetic recording medium and its production | |
| JPS6173227A (en) | Magnetic recording medium | |
| JPH0262714A (en) | Magnetic recording medium | |
| JPH02189716A (en) | Magnetic recording medium and production thereof |