JP2552682B2 - Magnetic disk substrate and manufacturing method thereof - Google Patents
Magnetic disk substrate and manufacturing method thereofInfo
- Publication number
- JP2552682B2 JP2552682B2 JP62238672A JP23867287A JP2552682B2 JP 2552682 B2 JP2552682 B2 JP 2552682B2 JP 62238672 A JP62238672 A JP 62238672A JP 23867287 A JP23867287 A JP 23867287A JP 2552682 B2 JP2552682 B2 JP 2552682B2
- Authority
- JP
- Japan
- Prior art keywords
- silica sol
- magnetic disk
- disk substrate
- sio
- sol
- 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
Landscapes
- Magnetic Record Carriers (AREA)
- Manufacturing Of Magnetic Record Carriers (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 この発明はゾル・ゲル法によりSiO2の被覆を設けた耐
熱性を向上させた磁気ディスク用基板に関する。TECHNICAL FIELD The present invention relates to a magnetic disk substrate having a SiO 2 coating formed by a sol-gel method to improve heat resistance.
近年高密度記録媒体としてめっき法もしくはスパッタ
法による金属薄膜媒体が実用化されはじめた。これら記
録媒体用の磁気ディスク用基板としては次のような特性
が要求される。In recent years, a metal thin film medium by a plating method or a sputtering method has begun to be put into practical use as a high density recording medium. The following characteristics are required for magnetic disk substrates for these recording media.
すなわち、(1)磁気ヘッドの浮上高さの減少にとも
ない磁気ヘッドの安定な浮上性を確保するため、表面粗
度が優れていること、(2)基板表面に突起、孔状のへ
こみがないこと、(3)機械加工あるいは使用時の高速
回転に十分に耐える機械的強度を有すること、そして
(4)耐食性、耐候性、耐熱性に優れていることであ
る。そのため通常はアルミニウム合金円板上にNi−Pめ
っき層を設け、ポリッシング加工を施こし上記の特性を
満たしている。That is, (1) the surface roughness is excellent in order to ensure stable flying of the magnetic head as the flying height of the magnetic head decreases, and (2) there is no protrusion or hole-like dent on the substrate surface. That is, (3) it has sufficient mechanical strength to withstand high-speed rotation during machining or use, and (4) it has excellent corrosion resistance, weather resistance, and heat resistance. Therefore, a Ni-P plating layer is usually provided on an aluminum alloy disk, and a polishing process is performed to satisfy the above characteristics.
しかしながら、Ni−Pめっき膜は鏡面にするためのポ
リッシング加工が不可欠であり、製造工程が長くなるう
えに250℃以上の加熱処理により、Ni−Pめっき膜が磁
化してしまうという問題がある。とくに、スパッタ法に
よる金属磁性薄膜の形成には磁気ディスク用基板に加熱
処理を施す必要があるが、記録特性を向上させるために
は少なくとも300℃の加熱に耐える基板が望まれてい
る。However, the Ni-P plated film needs a polishing process to make it a mirror surface, and there is a problem that the manufacturing process becomes long and the Ni-P plated film is magnetized by the heat treatment at 250 ° C. or higher. In particular, it is necessary to subject the magnetic disk substrate to heat treatment in order to form a metal magnetic thin film by the sputtering method, but a substrate that can withstand heating of at least 300 ° C. is desired in order to improve recording characteristics.
本発明は上記の問題点を解決し、300℃以上の耐熱性
をもつアルミニウム合金系の磁気ディスク用基板を提供
することを目的とする。An object of the present invention is to solve the above problems and provide an aluminum alloy-based magnetic disk substrate having a heat resistance of 300 ° C. or higher.
本発明の第1はアルミニウム合金円板の表面にゾル・
ゲル法によるSiO2の被覆を設けた磁気ディスク用基板で
ある。また、本発明の第2はアルミニウム合金円板の表
面にアルコール性シリカゾルと水分散シリカゾルの混合
物を塗布し、加熱・硬化させることを特徴とするSiO2の
被覆を設けた磁気ディスク用基板の製造法である。The first of the present invention is that the sol.
A magnetic disk substrate provided with a SiO 2 coating by a gel method. A second aspect of the present invention is the production of a magnetic disk substrate provided with a SiO 2 coating characterized by applying a mixture of an alcoholic silica sol and a water-dispersed silica sol to the surface of an aluminum alloy disk and heating and curing the mixture. Is the law.
本発明においてゾル・ゲル法とは末端基が部分的ある
いは、すべてOH基になったゾル(液体、コロイド)よ
り、縮合(シロキサン結合の生成)を進め、ゲル(固
体)化させる方法である。In the present invention, the sol-gel method is a method of promoting condensation (formation of siloxane bond) from a sol (liquid or colloid) having terminal groups partially or wholly OH groups to form a gel (solid).
ゾル・ゲル法に用いる原料にはSiO2分10〜41重量%の
アルコール性シリカゾルとSiO2分20〜50重量%の水分散
シリカゾルの混合物を使用する。その混合比はアルコー
ル性シリカゾルを2〜40重量%にすることが適当であ
る。また、水分散シリカゾルはNa2O 0.7重量%以下を
含有し、pH8〜11のものが好ましい。The raw material used in the sol-gel process using a mixture of SiO 2 minutes 10-41% by weight of the alcoholic silica sol and SiO 2 minutes 20-50 wt% of water dispersed silica sol. The mixing ratio of the alcoholic silica sol is preferably 2 to 40% by weight. Further, the water-dispersed silica sol preferably contains 0.7% by weight or less of Na 2 O and has a pH of 8-11.
アルコール性シリカゾルを加えるのは、水分散性シリ
カゲル単独ではガラス状に固化させるために高温での焼
成が必要となるが、アルコール性シリカゾルを加えるこ
とにより比較的低温でのガラス化が可能となるためであ
る。Addition of alcoholic silica sol requires water-dispersible silica gel alone to be fired at a high temperature in order to solidify into glass, but addition of alcoholic silica sol enables vitrification at a relatively low temperature. Is.
なお、アルコール性シリカゾルはアルキルシリケート
を酸性または塩基性触媒下でエタノール、イソプロパノ
ール等のアルコール類を溶媒として加水分解して得たも
のがとくに好ましい。The alcoholic silica sol is particularly preferably one obtained by hydrolyzing an alkyl silicate in the presence of an alcohol such as ethanol or isopropanol under an acidic or basic catalyst as a solvent.
シリカゾルの粒径は0.005μm〜0.1μmのものを使用
する。ガラス状に固化したときの基板表面の平滑性を考
慮すると、シリカゾルの粒径は0.05μm以下が望まし
い。The particle size of the silica sol used is 0.005 μm to 0.1 μm. Considering the smoothness of the substrate surface when it is solidified into glass, the particle size of silica sol is preferably 0.05 μm or less.
必要に応じてアルコール性シリカゾルと水分散シリカ
ゾルの混合物に充てん剤を加える。充てん剤はAl2O3、T
iO2、ZrO2、Cr2O3、CoO、SnO2等の金属酸化物あるい
は、SiC、カーボンブラック、Si3N4等である。これらの
充てん剤は混合液に対して0〜20重量%加えるのが適当
である。アルミニウム合金円板の表面を脱脂処理したの
ち、シリカゾルを塗布する。塗布の方法はディッピング
法が望ましい。シリカゾルを塗布した後、加熱処理を行
なう。加熱は50〜700℃で3〜60分行ない硬化させる。
硬化後のSiO2の被膜の厚みはピンホールをなくすために
少なくとも10μm以上あることが好ましい。If necessary, a filler is added to the mixture of alcoholic silica sol and water-dispersed silica sol. The filler is Al 2 O 3 , T
Metal oxides such as iO 2 , ZrO 2 , Cr 2 O 3 , CoO, and SnO 2 , or SiC, carbon black, Si 3 N 4, and the like. It is appropriate to add these fillers in an amount of 0 to 20% by weight based on the mixed solution. After degreasing the surface of the aluminum alloy disc, silica sol is applied. The coating method is preferably a dipping method. After applying the silica sol, heat treatment is performed. Heating is performed at 50 to 700 ° C. for 3 to 60 minutes to cure.
The thickness of the SiO 2 coating after curing is preferably at least 10 μm or more in order to eliminate pinholes.
以下に本発明の実施例について詳細を説明する。 Examples of the present invention will be described in detail below.
エチルシリケートを酢酸触媒でエタノールを溶媒とし
て加水分解してアルコール性シリカゾルを得た。SiO2分
40重量%のエチルシリケート75重量部に対してエタノー
ル16重量部、水8重量部、酢酸1重量部を混合し、撹拌
しながら12時間放置した。このアルコール性シリカゾル
は30重量のSiO2分を含む。Ethyl silicate was hydrolyzed with an acetic acid catalyst using ethanol as a solvent to obtain an alcoholic silica sol. SiO 2 minutes
16 parts by weight of ethanol, 8 parts by weight of water and 1 part by weight of acetic acid were mixed with 75 parts by weight of ethyl silicate of 40% by weight, and the mixture was left for 12 hours while stirring. This alcoholic silica sol contains 30 parts by weight of SiO 2 .
このアルコール性シリカゾルが20重量%、粒径70〜90
Åの水分散シリカゾルを76重量%、粒径350〜550Åの水
分散性シリカゾルを4重量%混合し、この混合液に対し
て20重量%のAl2O3を加えた。水分散シリカゾルはSiO2
分30〜40重量%でNa2O 0.7重量%以下、pH9〜10.5であ
った。20% by weight of this alcoholic silica sol, particle size 70-90
76 wt% of the water-dispersible silica sol of Å and 4 wt% of the water-dispersible silica sol having a particle diameter of 350 to 550 Å were mixed, and 20 wt% of Al 2 O 3 was added to this mixed solution. Water-dispersed silica sol is SiO 2
At 30-40% by weight, the content of Na 2 O was 0.7% by weight or less and the pH was 9-10.5.
アルミニウム合金円板を脱脂処理した後、上記のシリ
カゾルをディッピング法で塗布した。次にオーブンで70
℃より徐々に温度を上げ、200℃で30分加熱した。得ら
れたSiO2の被膜の厚みは10μmであった。上記の磁気デ
ィスク用基板は表面粗度Ra 0.003μm、Rmax 0.020μm
以下であり、表面の平滑性が非常に優れていた。また、
表面にはピンホールも突起もなかった。After degreasing the aluminum alloy disc, the above silica sol was applied by a dipping method. Then in the oven 70
The temperature was gradually raised from ℃ and heated at 200 ℃ for 30 minutes. The thickness of the obtained SiO 2 film was 10 μm. The above magnetic disk substrate has a surface roughness Ra of 0.003 μm and Rmax of 0.020 μm.
And the surface smoothness was very excellent. Also,
There were no pinholes or protrusions on the surface.
本発明の実施例の磁気ディスク用基板を350℃に加熱
し、スパッタリング法によりCoNiCr磁性層、C保護膜を
順次成膜したところ、磁気ディスクとしての磁気特性、
記録特性とも優れていた。すなわち、保持力、再生出力
が増加した。The magnetic disk substrate of the example of the present invention was heated to 350 ° C., and a CoNiCr magnetic layer and a C protective film were sequentially formed by a sputtering method.
The recording characteristics were also excellent. That is, the holding power and the reproduction output increased.
アルミニウム合金円板の表面にゾル・ゲル法によるSi
O2膜被膜を設けた本発明の磁気ディスク用基板は従来の
Ni−P膜を被覆したものより耐熱性が優れており、より
高温に加熱して磁性層を設けることができる。その結
果、磁気ディスクの特性を向上せることができる。Si by sol-gel method on the surface of aluminum alloy disc
The magnetic disk substrate of the present invention provided with the O 2 film coating is
It has better heat resistance than the Ni-P film coated, and can be heated to a higher temperature to form the magnetic layer. As a result, the characteristics of the magnetic disk can be improved.
さらに、本発明の磁気ディスク用基板はポリッシング
加工が不用であり、従来のNi−Pを被覆した基板より簡
単な工程で製造できる。Further, the magnetic disk substrate of the present invention does not require polishing, and can be manufactured by a simpler process than the conventional Ni-P coated substrate.
Claims (2)
法によるSiO2の被覆を設けた磁気ディスク用基板。1. A magnetic disk substrate having a surface of an aluminum alloy disk coated with SiO 2 by a sol-gel method.
性シリカゾルと水分散シリカゾルの混合物を塗布し、加
熱・硬化させることを特徴とするSiO2の被覆を設けた磁
気ディスク用基板の製造法。 2. A method for producing a magnetic disk substrate provided with a SiO 2 coating, which comprises coating a mixture of an alcoholic silica sol and a water-dispersed silica sol on the surface of an aluminum alloy disk and heating and curing the mixture.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP62238672A JP2552682B2 (en) | 1987-09-25 | 1987-09-25 | Magnetic disk substrate and manufacturing method thereof |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP62238672A JP2552682B2 (en) | 1987-09-25 | 1987-09-25 | Magnetic disk substrate and manufacturing method thereof |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS6482331A JPS6482331A (en) | 1989-03-28 |
JP2552682B2 true JP2552682B2 (en) | 1996-11-13 |
Family
ID=17033599
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP62238672A Expired - Fee Related JP2552682B2 (en) | 1987-09-25 | 1987-09-25 | Magnetic disk substrate and manufacturing method thereof |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP2552682B2 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2014051088A1 (en) | 2012-09-29 | 2014-04-03 | 京セラ株式会社 | Silicon nitride sintered compact, heating device and adsorption device |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2007024207A (en) * | 2005-07-19 | 2007-02-01 | Ntn Corp | Needle roller bearing |
EP2060808B1 (en) | 2006-09-04 | 2012-10-10 | NTN Corporation | Roller bearing, cam shaft support structure, internal combustion engine, and method of assembling roller bearing |
JP2008232310A (en) * | 2007-03-21 | 2008-10-02 | Jtekt Corp | Roller bearing |
JP2008232311A (en) * | 2007-03-21 | 2008-10-02 | Jtekt Corp | Roller bearing |
KR20110061288A (en) * | 2009-12-01 | 2011-06-09 | 삼성전자주식회사 | Charge roller for image forming apparatus and method of manufacturing the same |
JP6085209B2 (en) * | 2013-03-27 | 2017-02-22 | 株式会社神戸製鋼所 | Method for producing SiO2 film-coated aluminum plate |
JP6261399B2 (en) * | 2014-03-17 | 2018-01-17 | 株式会社神戸製鋼所 | Aluminum substrate for magnetic recording media |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS59108028A (en) * | 1982-12-13 | 1984-06-22 | Teijin Ltd | Manufacture of polyester film for magnetic recording medium |
JPS59207422A (en) * | 1983-05-12 | 1984-11-24 | Matsushita Electric Ind Co Ltd | Magnetic recording medium |
-
1987
- 1987-09-25 JP JP62238672A patent/JP2552682B2/en not_active Expired - Fee Related
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2014051088A1 (en) | 2012-09-29 | 2014-04-03 | 京セラ株式会社 | Silicon nitride sintered compact, heating device and adsorption device |
Also Published As
Publication number | Publication date |
---|---|
JPS6482331A (en) | 1989-03-28 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
LAPS | Cancellation because of no payment of annual fees |