JPH09208260A - Crystallized glass substrate for magnetic disk - Google Patents
Crystallized glass substrate for magnetic diskInfo
- Publication number
- JPH09208260A JPH09208260A JP4214496A JP4214496A JPH09208260A JP H09208260 A JPH09208260 A JP H09208260A JP 4214496 A JP4214496 A JP 4214496A JP 4214496 A JP4214496 A JP 4214496A JP H09208260 A JPH09208260 A JP H09208260A
- Authority
- JP
- Japan
- Prior art keywords
- crystallized glass
- magnetic disk
- glass
- substrate
- cristobalite
- 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.)
- Granted
Links
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、磁気ディスク用基
板に関し、特にコンタクト・レコーディングに適した磁
気ディスク用ガラスセラミック基板に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk substrate, and more particularly to a glass ceramic substrate for a magnetic disk suitable for contact recording.
【０００２】[0002]
【従来の技術】パーソナルコンピュータのマルチメディ
ア化に伴い大容量の磁気ディスク装置が必要となってい
る。その結果、磁気ディスクは、面記録密度を大きくす
るために、ビットおよびトラック密度を増加させ、ビッ
トセルのサイズを縮少化する必要がある。ビットセルの
縮少化に対応して磁気ヘッドはディスク表面により接近
して作動する必要が生じ、磁気ヘッドのディスク表面か
らの浮上量を０．０２５μｍ以下として磁気ヘッドとデ
ィスクがほとんど接触した状態で記録が行われるコンタ
クト・レコーディング方式が求められている。2. Description of the Related Art As personal computers become multimedia, a large-capacity magnetic disk device is required. As a result, in the magnetic disk, it is necessary to increase the bit and track densities and reduce the bit cell size in order to increase the areal recording density. The magnetic head needs to operate closer to the disk surface in response to the shrinking of bit cells, and the flying height of the magnetic head from the disk surface is 0.025 μm or less and recording is performed with the magnetic head and disk almost in contact with each other. The contact recording method is required.
【０００３】[0003]
【発明が解決しようとする課題】このようなコンタクト
・レコーディング方式においては、磁気ディスクは、
０．０２５μｍ以下の磁気ヘッドの浮上量を可能にする
ため、表面粗度（Ｒａ）が１０Å以下であることが要求
される上に、磁気ヘッドとの接触に耐えられる充分に高
い耐摩耗性を有することが要求される。In such a contact recording system, the magnetic disk is
In order to enable the flying height of the magnetic head to be 0.025 μm or less, the surface roughness (Ra) is required to be 10 Å or less, and the wear resistance is sufficiently high to withstand contact with the magnetic head. Required to have.
【０００４】従来磁気ディスク基板材には、アルミニウ
ム合金が使用されているが、アルミニウム合金基板で
は、種々の材料欠陥の影響により、研磨工程における基
板表面の突起またはスポット状の凹凸を生じ平坦性、平
滑性の点で十分でなく、またアルミニウム合金は軟かい
材料であるため、変形が生じやすく薄形化に対応するこ
とがむずかしく、さらにはヘッドの接触による変形傷を
生じメディアを損傷させてしまう等今日の高密度記録化
に十分対応できない。Conventionally, an aluminum alloy has been used as a magnetic disk substrate material. However, in the aluminum alloy substrate, due to the influence of various material defects, protrusions or spot-like irregularities are formed on the substrate surface in the polishing step, and flatness, The smoothness is not sufficient, and aluminum alloy is a soft material, so it is easy to deform and it is difficult to cope with thinning, and further, deformation damage due to contact of the head and damage to the media It is not possible to cope with today's high density recording.
【０００５】また、アルミニウム合金基板の問題点を解
消する材料として化学強化ガラスのソーダライムガラス
（ＳｉＯ2 −ＣａＯ−Ｎａ2 Ｏ）とアルミノシリケート
ガラス（ＳｉＯ2 −Ａｌ2 Ｏ−Ｎａ2 Ｏ）が知られてい
るが、この場合（イ）研磨は化学強化後に行なわれ、デ
ィスクの薄板化における強化層の不安定要素が高い。
（ロ）ガラス中にＮａ2 Ｏ成分を必須成分として含有す
るため、成膜特性が悪化し、Ｎａ2 Ｏ溶出防止のための
全面バリアコート処理が必要となり、製品の低コスト安
定生産性が難しいという欠点がある。As materials for solving the problems of the aluminum alloy substrate, chemically strengthened soda lime glass (SiO 2 —CaO—Na 2 O) and aluminosilicate glass (SiO 2 —Al 2 O—Na 2 O) are used. As is known, in this case, (a) polishing is performed after chemical strengthening, and the instability factor of the strengthening layer in the thinning of the disk is high.
(B) Since the glass contains the Na 2 O component as an essential component, the film forming characteristics are deteriorated, and it is necessary to perform a full-scale barrier coat treatment to prevent Na 2 O elution. There is a drawback that.
【０００６】さらに、アルミニウム合金基板や化学強化
ガラス基板に対していくつかの結晶化ガラスが知られて
いる。例えば、特開平６−３２９４４０号公報記載のＳ
ｉＯ2 −Ｌｉ2 Ｏ−ＭｇＯ−Ｐ2 Ｏ5 系結晶化ガラス
は、主結晶相として二珪酸リチウム（Ｌｉ2 Ｏ・２Ｓｉ
Ｏ2 ）およびα−クオーツ（α−ＳｉＯ2 ）を有し、α
−クオーツ（α−ＳｉＯ2 ）の球状粒子サイズをコント
ロールすることができるが、研磨して成る表面粗度（Ｒ
ａ）が１５〜５０Åの範囲であって、目標とする表面粗
度（Ｒａ）が１０Å以下の急速に進む記録容量向上に合
せた低浮上化に十分対応することができない。Further, some crystallized glasses are known for aluminum alloy substrates and chemically strengthened glass substrates. For example, S described in JP-A-6-329440
iO 2 —Li 2 O—MgO—P 2 O 5 -based crystallized glass has lithium disilicate (Li 2 O · 2Si) as a main crystal phase.
O 2 ) and α-quartz (α-SiO 2 );
-The size of the spherical particles of quartz (α-SiO 2 ) can be controlled, but the surface roughness (R
a) is in the range of 15 to 50 Å, the target surface roughness (Ra) cannot sufficiently cope with the low flying height corresponding to the rapid increase in recording capacity of 10 Å or less.
【０００７】本発明の目的は、ハードディスクの高密度
化によるコンタクト・レコーディング方式に対応するた
め、前記従来技術の欠点を解消し、１０Å以下の表面粗
度を有するとともに高い耐摩耗性を有する磁気ディスク
用結晶化ガラス基板を提供することにある。The object of the present invention is to cope with the contact recording method by increasing the density of the hard disk, so that the drawbacks of the prior art described above are solved, and the magnetic disk has a surface roughness of 10 Å or less and a high wear resistance. It is to provide a crystallized glass substrate for use.
【０００８】[0008]
【課題を解決するための手段】本発明者は、上記目的を
達成するため研究と実験を重ねた結果、ＳｉＯ2 −Ｌｉ
2 Ｏ−Ａｌ2 Ｏ3 −Ｐ2 Ｏ5 系においてＭｇＯ成分とＺ
ｎＯ成分を必須成分とする原ガラスを厳密に限定された
熱処理条件下で熱処理することにより得られる主結晶相
がα−クリストバライト（α−ＳｉＯ2 ）および二珪酸
リチウム（Ｌｉ2 Ｏ・２ＳｉＯ2 ）からなる結晶化ガラ
スにおいて、二珪酸リチウムに対するα−クリストバラ
イトの構成比率を０．２５〜０．３５という狹い範囲に
限定することにより、磁気ディスク基板の研磨してなる
表面粗度（Ｒａ）が２〜１０Åであり、かつ摩耗度（Ａ
ａ）が５〜１５の範囲内にあるというコンタクト・レコ
ーディングに理想的な磁気ディスク基板が得られること
を見出し、本発明に到達した。SUMMARY OF THE INVENTION The present inventor has extensive research and experimentation in order to achieve the above object, SiO 2 -Li
In the 2 O-Al 2 O 3 -P 2 O 5 system, MgO component and Z
The main crystal phases obtained by heat-treating the raw glass containing the nO component as an essential component under strictly defined heat-treatment conditions are α-cristobalite (α-SiO 2 ) and lithium disilicate (Li 2 O · 2SiO 2 ). In the crystallized glass consisting of, by limiting the composition ratio of α-cristobalite to lithium disilicate within a narrow range of 0.25 to 0.35, the surface roughness (Ra) obtained by polishing the magnetic disk substrate is 2 to 10Å and wear degree (A
The inventors have found that an ideal magnetic disk substrate can be obtained for contact recording in which a) is in the range of 5 to 15, and reached the present invention.
【０００９】すなわち、上記本発明の目的を達成する請
求項１記載の磁気ディスク用結晶化ガラス基板は、結晶
化ガラスの主結晶相がα−クリストバライト（α−Ｓｉ
Ｏ2）および二珪酸リチウム（Ｌｉ2 Ｏ．２ＳｉＯ2 ）
であって、該結晶相の構成比率はα−クリストバライト
／二珪酸リチウムが０．２５〜０．３５であり、結晶粒
子の粒径が０．１〜１．０μｍの範囲の値を有し、磁気
ディスク基板の研磨してなる表面粗度（Ｒａ）が２〜１
０Åであり、かつ、摩耗度（Ａａ）が５〜１５の範囲内
であることを特徴とするものである。That is, in the crystallized glass substrate for a magnetic disk according to claim 1 which achieves the object of the present invention, the main crystal phase of the crystallized glass is α-cristobalite (α-Si).
O 2 ) and lithium disilicate (Li 2 O.2SiO 2 )
The composition ratio of the crystal phase is α-cristobalite / lithium disilicate of 0.25 to 0.35, and the particle size of the crystal particles has a value in the range of 0.1 to 1.0 μm. The surface roughness (Ra) obtained by polishing the magnetic disk substrate is 2-1.
It is characterized in that it is 0Å and the degree of wear (Aa) is in the range of 5 to 15.
【００１０】また、請求項２記載の磁気ディスク用結晶
化ガラス基板は、請求項１記載の磁気ディスク用基板に
おいて、結晶化ガラスは重量百分率で、ＳｉＯ2 ７５
〜８３％、Ｌｉ2 Ｏ ７〜１３％、Ａｌ2 Ｏ3 １〜５
％、Ｐ2 Ｏ5 １〜３％、ＭｇＯ ０．５〜３％、Ｚｎ
Ｏ ０．５〜３％、Ｋ2 Ｏ ０〜５％、Ａｓ2 Ｏ3 及び
／又はＳｂ2 Ｏ3 ０〜２％からなる原ガラスを熱処理
することによって得られることを特徴とする。The crystallized glass substrate for a magnetic disk according to claim 2 is the same as the magnetic disk substrate according to claim 1, in which the crystallized glass is SiO 2 75% by weight.
~83%, Li 2 O 7~13% , Al 2 O 3 1~5
%, P 2 O 5 1~3% , 0.5~3% MgO, Zn
It is characterized by being obtained by heat-treating a raw glass composed of O 0.5 to 3%, K 2 O 0 to 5%, As 2 O 3 and / or Sb 2 O 3 0 to 2%.
【００１１】本発明の結晶化ガラスの組成は、原ガラス
と同様酸化物基準で表示し得るが、原ガラスの組成範囲
を上記のように限定した理由について以下に述べる。The composition of the crystallized glass of the present invention can be expressed on the basis of oxides like the original glass, but the reason why the composition range of the original glass is limited as described above will be described below.
【００１２】ＳｉＯ2 成分は、原ガラスの熱処理によ
り、主結晶相として二珪酸リチウム（Ｌｉ2 Ｏ・２Ｓｉ
Ｏ2 ）およびα−クリストバライトを生成する極めて重
要な成分であるが、その量が７５．０％未満では、得ら
れるガラスの析出結晶が不安定で組織が粗大化しやす
く、また８３．０％を超えると原ガラスの溶融が困難と
なる。The SiO 2 component is a main crystal phase of lithium disilicate (Li 2 O.2Si) produced by heat treatment of the raw glass.
O 2 ) and α-cristobalite are extremely important components, but if the amount is less than 75.0%, the precipitated crystals of the glass obtained are unstable and the structure tends to become coarse. If it exceeds, it becomes difficult to melt the raw glass.
【００１３】Ｌｉ2 Ｏ成分は、ガラスの加熱処理により
主結晶相として二珪酸リチウム（Ｌｉ2 Ｏ・２Ｓｉ
Ｏ2 ）結晶を生成するきわめて重要な成分であるが、そ
の量が７％未満では上記結晶の析出が困難となると同時
に、原ガラスの溶融が困難となり、また、１３％を超え
ると得られる結晶化ガラスの析出結晶が不安定となり、
組織が粗大化しやすいうえ、化学的耐久性および硬度が
悪化する。Ｋ2 Ｏ成分はガラスの溶融性を向上させる成
分であり、５％まで含有できる。The Li 2 O component is a main crystal phase of lithium disilicate (Li 2 O.2Si) produced by heat treatment of glass.
O 2 ) is an extremely important component for forming crystals, but if the amount is less than 7%, it becomes difficult to precipitate the above-mentioned crystals, and at the same time, it becomes difficult to melt the raw glass, and if it exceeds 13%, the obtained crystals are obtained. The precipitated crystals of fog glass become unstable,
The structure tends to become coarse, and the chemical durability and hardness deteriorate. The K 2 O component is a component that improves the meltability of glass and can be contained up to 5%.
【００１４】ＭｇＯは析出結晶を規定する重要な成分で
あり、その量が０．５％未満であるとα−クリストバラ
イトの析出が増大し、耐摩耗性が悪化する。また、３％
を超えるとα−クオーツの析出が増大し、かつ粒子が粗
大化するため表面粗度が悪化する。またＺｎＯも同等の
効果があるので添加し得るが３％までとすべきである。MgO is an important component for defining precipitated crystals, and if its amount is less than 0.5%, the precipitation of α-cristobalite increases and wear resistance deteriorates. Also, 3%
If it exceeds, the precipitation of α-quartz increases and the particles become coarse, so that the surface roughness deteriorates. ZnO also has the same effect and can be added, but it should be up to 3%.
【００１５】Ｐ2 Ｏ5 成分がガラスの結晶核形成剤とし
て不可欠であるが、その量が１％未満であるとＬｉ2 Ｏ
・２ＳｉＯ2 ，α−ＳｉＯ2 結晶の粒子が粗大化し所望
の表面粗度、摩耗度が得られない。また３％を超えると
ガラス成形時に失透しやすく、この失透による粒子の粗
大化が起こる。The P 2 O 5 component is indispensable as a crystal nucleating agent for glass, but if its amount is less than 1%, Li 2 O 5
The particles of 2SiO 2 , α-SiO 2 crystals become coarse, and the desired surface roughness and wear cannot be obtained. On the other hand, if it exceeds 3%, devitrification is likely to occur during glass forming, and the devitrification causes coarsening of particles.
【００１６】Ａｌ2 Ｏ3 成分は、結晶化ガラスの化学的
耐久性を向上させる有効な成分であるが含有量が１％未
満ではその目的を達成することができず、またその含有
量が５％を超えると溶融性が悪化する。Ａｓ2 Ｏ3 およ
び、またはＳｂ2 Ｏ3 成分は、ガラス溶融の際の清澄剤
として添加し得るが、これらの１種または、２種の合計
量は２％以下で充分である。The Al 2 O 3 component is an effective component for improving the chemical durability of crystallized glass, but if the content is less than 1%, the object cannot be achieved, and the content is 5%. If it exceeds%, the meltability will deteriorate. The As 2 O 3 and / or Sb 2 O 3 component can be added as a fining agent during glass melting, but the total amount of one or two of them is 2% or less.
【００１７】なお本発明においては、使用するガラスに
上記成分の他に所望の特性を損なわない程度で少量のＢ
2 Ｏ3 ，ＣａＯ，ＳｒＯ，ＢａＯ，ＴｉＯ2 ，ＳｎＯ，
およびＺｒＯ2 の成分を含有させることができる。In the present invention, in addition to the above-mentioned components, a small amount of B is added to the glass used so long as the desired characteristics are not impaired.
2 O 3 , CaO, SrO, BaO, TiO 2 , SnO,
And ZrO 2 can be included.
【００１８】また本発明の結晶化ガラス基板は、結晶化
した際の構成結晶相の比についてα−クリストバライト
／二珪酸リチウム＝０．２５〜０．３５に規定した。こ
れはＸＲＤのピーク高さにより各結晶相の割合を見、α
−クリストバライト（１０１），二珪酸リチウム（１３
０）のピーク面をそれぞれ使用し比を決定した。この比
を０．２５〜０．３５に限定した理由は、この構成比が
０．２５〜０．３５の範囲において研磨後の基板の表面
粗度が２〜１０Åという理想的な表面粗度が得られる上
に、図１に示すように、構成比が０．２５未満であるか
または０．３５を超えると摩耗度（Ａａ）が急激に悪化
し、０．２５〜０．３５の範囲内において摩耗度（Ａ
ａ）がおおむね１５以下の望ましい表面特性が得られる
ことが多くの実験の結果判明したからである。In the crystallized glass substrate of the present invention, the ratio of constituent crystal phases when crystallized was defined as α-cristobalite / lithium disilicate = 0.25 to 0.35. This is because the ratio of each crystal phase is determined by the peak height of XRD and α
-Cristobalite (101), lithium disilicate (13
The ratio was determined using each of the 0) peak planes. The reason for limiting this ratio to 0.25 to 0.35 is that the ideal surface roughness of 2 to 10 Å is the surface roughness of the substrate after polishing in the range of 0.25 to 0.35. In addition, as shown in FIG. 1, when the composition ratio is less than 0.25 or exceeds 0.35, the wear degree (Aa) sharply deteriorates and falls within the range of 0.25 to 0.35. Wear degree (A
This is because it was found as a result of many experiments that the desired surface characteristics of a) were about 15 or less.
【００１９】本発明の結晶化ガラス基板は摩耗度（Ａ
ａ）が５〜１５、好ましくは５〜１２の範囲内にあり、
これによって磁気ヘッドの浮上量が０．０２５μｍ以下
のコンタクト・レコーディングにおいても充分な耐摩耗
性を有する。The crystallized glass substrate of the present invention has a wear degree (A
a) is in the range 5 to 15, preferably 5 to 12,
As a result, sufficient wear resistance is obtained even in contact recording in which the flying height of the magnetic head is 0.025 μm or less.
【００２０】つぎに本発明にかかる磁気ディスク用結晶
化ガラスを製造するには、上記の組成を有するガラスを
溶解し熱間または／および冷間成形を行った後、核形成
４００℃〜５５０℃、結晶化７２０℃〜８２０℃の温度
で結晶化熱処理を行い、さらに熱処理結晶化したガラス
を通常一般に広く知られている方法でラッピングのあと
ポリッシングし表面粗度（Ｒａ）を２〜１０Åの範囲と
する。Next, in order to produce the crystallized glass for a magnetic disk according to the present invention, the glass having the above composition is melted, hot and / or cold forming is carried out, and then nucleation is carried out at 400 ° C. to 550 ° C. Crystallization, heat treatment for crystallization at a temperature of 720 ° C. to 820 ° C., and further heat treatment of the crystallized glass are lapped by a generally widely known method and then polished to obtain a surface roughness (Ra) in the range of 2 to 10 Å. And
【００２１】[0021]
【発明の実施の形態】つぎに本発明にかかる好適な実施
例につき説明する。表１〜表４は本発明の磁気ディスク
用結晶化ガラス基板の実施組成例（Ｎｏ．１〜１０）と
従来のＳｉＯ2 −Ｌｉ2 Ｏ−Ａｌ2 Ｏ3 −Ｐ2 Ｏ5 系結
晶化ガラスの比較組成例２例を、これらの結晶化ガラス
の核形成温度、結晶化温度、析出結晶相、結晶粒径、研
磨後の表面粗度（Ｒａ）、摩耗度の測定結果とともに示
す。なお組成は重量百分率で示す。BEST MODE FOR CARRYING OUT THE INVENTION Next, preferred embodiments of the present invention will be described. Tables 1 to 4 show examples of compositions of crystallized glass substrates for magnetic disks of the present invention (No. 1 to 10) and conventional SiO 2 —Li 2 O—Al 2 O 3 —P 2 O 5 based crystallized glass. The second comparative composition example is shown with the measurement results of the nucleation temperature, crystallization temperature, precipitated crystal phase, crystal grain size, surface roughness (Ra) after polishing, and abrasion degree of these crystallized glasses. The composition is shown by weight percentage.
【００２２】[0022]
【表１】 [Table 1]
【００２３】[0023]
【表２】 [Table 2]
【００２４】[0024]
【表３】 [Table 3]
【００２５】[0025]
【表４】 [Table 4]
【００２６】また本発明の実施例３および比較例１、２
の粒子状態を示す電子顕微鏡写真をそれぞれ図２、図３
および図４に示す。Example 3 of the present invention and Comparative Examples 1 and 2
2 and 3 are electron micrographs showing the state of the particles in FIG.
And FIG.
【００２７】上記実施例のガラスは、いずれも酸化物、
炭酸塩、硝酸塩等の原料を混合し、これを通常の溶解装
置を用いて約１３５０℃〜１５００℃の温度で溶融し、
攪拌均質化した後、所望の形状に成形して冷却し、ガラ
ス成形体を得た。その後これを熱処理して核形成後（４
００℃〜５５０℃）、結晶化温度（７２０℃〜８２０
℃）の間で約１〜５時間保持して、所望の結晶化ガラス
を得た。なお表面粗度測定試料製作にあたっては、上記
結晶化ガラスを平均粒径９〜１２μｍの砥粒にて約１０
分〜２０分間ポリッシングして仕上げた。摩耗度につい
ては日本光学硝子工業会で指定された方法により行っ
た。すなわち、試料の大きさ３０×３０×１０ｍｍのガ
ラス角板を水平に毎分６０回転する鋳鉄製平面皿（２５
０ｍｍφ）の中心から８０ｍｍの定位置にのせ、９．８
Ｎ｛１ｋｇｆ｝の荷重を垂直にかけながら、＃８００
（平均粒度２０μｍ）のラップ材（アルミナ質Ａ砥粒）
を１０ｇ添加した水２０ｍｌを５分間均等に供給して摩
耗させ、ラップ前後の試料質量を測定して摩耗質量を求
めた。また、同様にして日本工学硝子工業会で指定され
た標準試料の摩耗質量を求め次式によって算出した値を
摩耗度（Ａａ）とした。The glasses of the above examples are all oxides,
Raw materials such as carbonates and nitrates are mixed and melted at a temperature of about 1350 ° C to 1500 ° C using an ordinary melting device,
After stirring and homogenizing, it was molded into a desired shape and cooled to obtain a glass molded body. After that, this is heat treated to form nuclei (4
00 ° C to 550 ° C, crystallization temperature (720 ° C to 820 ° C)
C.) for about 1-5 hours to obtain the desired crystallized glass. In producing the sample for measuring the surface roughness, the above-mentioned crystallized glass was polished with an abrasive having an average particle size of 9 to 12 μm for about 10 times.
Finished by polishing for 20 minutes. The abrasion degree was measured by the method specified by the Japan Optical Glass Industry Association. That is, a glass square plate having a size of 30 × 30 × 10 mm of a sample is cast on a flat plate (25
0mmφ) at a fixed position of 80mm from the center, 9.8
Applying a load of N {1kgf} vertically, # 800
Wrap material (alumina A abrasive grain) with an average grain size of 20 μm
20 ml of water to which 10 g of was added was evenly supplied for 5 minutes to cause abrasion, and the sample mass before and after the lapping was measured to obtain the abrasion mass. Further, similarly, the wear mass of the standard sample designated by the Japan Engineering Glass Industry Association was obtained, and the value calculated by the following formula was defined as the wear degree (Aa).
【００２８】 [0028]
【００２９】表１にみられるとおり、実施例の結晶化ガ
ラスは、比較例に対し、いずれも表面粗度（Ｒａ）の値
が１０Å未満で、表面特性に優れており、目的の改善の
効果は顕著である。また摩耗度においてもいずれも１２
以下の小さな値を示し、優れた耐摩耗性を有しているこ
とがわかる。As can be seen from Table 1, the crystallized glasses of the examples have surface roughness (Ra) values of less than 10 Å as compared with the comparative examples. Is remarkable. Also, the degree of wear is 12
The following small values are shown, and it is understood that it has excellent wear resistance.
【００３０】[0030]
【発明の効果】以上述べたように、本発明によれば、結
晶化ガラスの主結晶相がα−クリストバライト（α−Ｓ
ｉＯ2 ）および二珪酸リチウム（Ｌｉ2 Ｏ．２Ｓｉ
Ｏ2 ）であって、該結晶相の構成比率はα−クリストバ
ライト／二珪酸リチウムが０．２５〜０．３５であり、
結晶粒子の粒径が０．１〜１．０μｍの範囲の値を有
し、磁気ディスク基板の研磨してなる表面粗度（Ｒａ）
が２〜１０Åであり、かつ、摩耗度（Ａａ）が５〜１５
の範囲内であることにより、コンタクト・レコーディン
グ用として好適な磁気ディスク用結晶化ガラス基板が得
られる。As described above, according to the present invention, the main crystal phase of crystallized glass is α-cristobalite (α-S).
iO 2 ) and lithium disilicate (Li 2 O.2Si
O 2 ), and the composition ratio of the crystal phase is α-cristobalite / lithium disilicate is 0.25 to 0.35,
Surface roughness (Ra) obtained by polishing a magnetic disk substrate having a crystal grain size in the range of 0.1 to 1.0 μm.
Is 2 to 10Å, and the wear degree (Aa) is 5 to 15
Within the range, a crystallized glass substrate for a magnetic disk suitable for contact recording can be obtained.
【図１】α−クリストバライト／二珪酸リチウム構成比
と摩耗度との関係を示すグラフである。FIG. 1 is a graph showing the relationship between the α-cristobalite / lithium disilicate composition ratio and the degree of wear.
【図２】本発明の実施例の粒子状態を示す電子顕微鏡写
真である。FIG. 2 is an electron micrograph showing a particle state of an example of the present invention.
【図３】比較例１の粒子状態を示す電子顕微鏡写真であ
る。FIG. 3 is an electron micrograph showing a particle state of Comparative Example 1.
【図４】比較例２の粒子状態を示す電子顕微鏡写真であ
る。FIG. 4 is an electron micrograph showing a particle state of Comparative Example 2.
Claims (2)
バライト（α−ＳｉＯ2 ）および二珪酸リチウム（Ｌｉ
2 Ｏ．２ＳｉＯ2 ）であって、該結晶相の構成比率はα
−クリストバライト／二珪酸リチウムが０．２５〜０．
３５であり、結晶粒子の粒径が０．１〜１．０μｍの範
囲の値を有し、磁気ディスク基板の研磨してなる表面粗
度（Ｒａ）が２〜１０Åであり、かつ、摩耗度（Ａａ）
が５〜１５の範囲内であることを特徴とする磁気ディス
ク用結晶化ガラス基板。1. The main crystal phase of crystallized glass is α-cristobalite (α-SiO 2 ) and lithium disilicate (Li.
2 O. 2SiO 2 ) and the composition ratio of the crystal phase is α
-Cristobalite / lithium disilicate 0.25-0.
35, the grain size of the crystal particles has a value in the range of 0.1 to 1.0 μm, the surface roughness (Ra) obtained by polishing the magnetic disk substrate is 2 to 10 Å, and the degree of wear is (Aa)
Is in the range of 5 to 15. A crystallized glass substrate for a magnetic disk, wherein:
Ｏ2 ７５〜８３％、Ｌｉ2 Ｏ ７〜１３％、Ａｌ2 Ｏ
3 １〜５％、Ｐ2 Ｏ5 １〜３％、ＭｇＯ０．５〜３
％、ＺｎＯ ０．５〜３％、Ｋ2 Ｏ ０〜５％、Ａｓ2
Ｏ3 及び／又はＳｂ2 Ｏ3 ０〜２％からなる原ガラス
を熱処理することによって得られることを特徴とする請
求項１に記載の磁気ディスク用結晶化ガラス基板。2. The crystallized glass, in percentage by weight, is Si
O 2 75~83%, Li 2 O 7~13%, Al 2 O
3 1~5%, P 2 O 5 1~3%, MgO0.5~3
%, 0.5~3% ZnO, K 2 O 0~5%, As 2
The crystallized glass substrate for a magnetic disk according to claim 1, wherein the crystallized glass substrate for a magnetic disk is obtained by heat-treating a raw glass made of O 3 and / or Sb 2 O 3 0 to 2%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP08042144A JP3131138B2 (en) | 1996-02-05 | 1996-02-05 | Crystallized glass substrate for magnetic disk |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP08042144A JP3131138B2 (en) | 1996-02-05 | 1996-02-05 | Crystallized glass substrate for magnetic disk |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP29613398A Division JP3152905B2 (en) | 1996-02-05 | 1998-10-02 | Crystallized glass substrate for magnetic disk |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH09208260A true JPH09208260A (en) | 1997-08-12 |
| JP3131138B2 JP3131138B2 (en) | 2001-01-31 |
Family
ID=12627755
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP08042144A Expired - Fee Related JP3131138B2 (en) | 1996-02-05 | 1996-02-05 | Crystallized glass substrate for magnetic disk |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3131138B2 (en) |
Cited By (29)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6284340B1 (en) | 1999-09-29 | 2001-09-04 | Ngk Insulators, Ltd. | Crystallized glass, magnetic disc substrate and magnetic disc |
| US6372319B1 (en) | 1998-09-10 | 2002-04-16 | Ngk Insulators, Ltd. | Nucleating agents for crystallized glasses, crystallized glasses, magnetic discs substrate and magnetic discs |
| US6458728B1 (en) | 1999-07-06 | 2002-10-01 | Minolta Co., Ltd. | Glass-ceramic composition for recording disk substrate |
| US6458730B1 (en) | 1999-07-14 | 2002-10-01 | Minolta Co., Ltd. | Glass-ceramic composition for recording disk substrate |
| US6458729B1 (en) | 1999-07-14 | 2002-10-01 | Minolta Co., Ltd. | Glass-ceramic composition for recording disk substrate |
| US6514890B1 (en) | 1999-07-06 | 2003-02-04 | Minolta Co., Ltd. | Glass-ceramic composition for recording disk substrate |
| US6524982B1 (en) | 1999-07-06 | 2003-02-25 | Minolta Co., Ltd. | Glass-ceramic composition for recording disk substrate |
| US6569791B1 (en) | 1999-07-14 | 2003-05-27 | Minolta Co., Ltd. | Glass-ceramic composition for recording disk substrate |
| US6569790B1 (en) | 1999-07-14 | 2003-05-27 | Minolta Co., Ltd. | Glass-ceramic composition for recording disk substrate |
| US6573206B1 (en) | 1999-07-14 | 2003-06-03 | Minolta Co., Ltd. | Glass-ceramic composition for recording disk substrate |
| US6583077B1 (en) | 1999-07-14 | 2003-06-24 | Minolta Co., Ltd. | Glass-ceramic composition for recording disk substrate |
| US6583078B1 (en) | 1999-07-14 | 2003-06-24 | Minolta Co., Ltd. | Glass-ceramic composition for recording disk substrate |
| US6593259B1 (en) | 1999-07-14 | 2003-07-15 | Minolta Co., Ltd. | Glass-ceramic composition for recording disk substrate |
| US6593257B1 (en) | 1999-07-06 | 2003-07-15 | Minolta Co., Ltd. | Glass-ceramic composition for recording disk substrate |
| US6596659B1 (en) | 1999-07-14 | 2003-07-22 | Minolta Co., Ltd. | Glass-ceramic composition for recording disk substrate |
| US6610620B1 (en) | 1999-07-14 | 2003-08-26 | Minolta Co., Ltd. | Glass-ceramic composition for recording disk substrate |
| US6624101B1 (en) | 1999-07-14 | 2003-09-23 | Minolta Co., Ltd. | Glass-ceramic composition for recording disk substrate |
| US6627567B1 (en) | 1999-07-14 | 2003-09-30 | Minolta Co., Ltd. | Glass-ceramic composition for recording disk substrate |
| US6635591B2 (en) | 2000-04-03 | 2003-10-21 | Minolta Co., Ltd. | Glass composition for crystallized glass |
| US6642161B2 (en) | 2000-04-03 | 2003-11-04 | Minolta Co., Ltd. | Glass composition for crystallized glass |
| US6642162B2 (en) | 2000-04-03 | 2003-11-04 | Minolta Co., Ltd. | Glass composition for crystallized glass |
| US6645888B2 (en) | 2000-04-03 | 2003-11-11 | Minolta Co., Ltd. | Glass composition for crystallized glass |
| US6645892B2 (en) | 2000-04-03 | 2003-11-11 | Minolta Co., Ltd. | Glass composition for crystallized glass |
| US6645889B2 (en) | 2000-04-03 | 2003-11-11 | Minolta Co., Ltd. | Glass composition for crystallized glass |
| US6645890B2 (en) | 2000-04-03 | 2003-11-11 | Minolta Co., Ltd. | Glass composition for crystallized glass |
| US6645891B2 (en) | 2000-04-03 | 2003-11-11 | Minolta Co., Ltd. | Glass composition for crystallized glass |
| US6649549B2 (en) | 2000-04-03 | 2003-11-18 | Minolta Co., Ltd. | Glass composition for crystallized glass |
| US7589038B2 (en) | 2005-10-07 | 2009-09-15 | Ohara Inc. | Inorganic composition |
| JP2015504399A (en) * | 2011-10-14 | 2015-02-12 | イフォクレール ヴィヴァデント アクチェンゲゼルシャフトＩｖｏｃｌａｒ Ｖｉｖａｄｅｎｔ ＡＧ | Lithium silicate glass ceramic and lithium silicate glass containing divalent metal oxide |
-
1996
- 1996-02-05 JP JP08042144A patent/JP3131138B2/en not_active Expired - Fee Related
Cited By (33)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6372319B1 (en) | 1998-09-10 | 2002-04-16 | Ngk Insulators, Ltd. | Nucleating agents for crystallized glasses, crystallized glasses, magnetic discs substrate and magnetic discs |
| US6514890B1 (en) | 1999-07-06 | 2003-02-04 | Minolta Co., Ltd. | Glass-ceramic composition for recording disk substrate |
| US6458728B1 (en) | 1999-07-06 | 2002-10-01 | Minolta Co., Ltd. | Glass-ceramic composition for recording disk substrate |
| US6593257B1 (en) | 1999-07-06 | 2003-07-15 | Minolta Co., Ltd. | Glass-ceramic composition for recording disk substrate |
| US6524982B1 (en) | 1999-07-06 | 2003-02-25 | Minolta Co., Ltd. | Glass-ceramic composition for recording disk substrate |
| US6624101B1 (en) | 1999-07-14 | 2003-09-23 | Minolta Co., Ltd. | Glass-ceramic composition for recording disk substrate |
| US6458729B1 (en) | 1999-07-14 | 2002-10-01 | Minolta Co., Ltd. | Glass-ceramic composition for recording disk substrate |
| US6569791B1 (en) | 1999-07-14 | 2003-05-27 | Minolta Co., Ltd. | Glass-ceramic composition for recording disk substrate |
| US6569790B1 (en) | 1999-07-14 | 2003-05-27 | Minolta Co., Ltd. | Glass-ceramic composition for recording disk substrate |
| US6573206B1 (en) | 1999-07-14 | 2003-06-03 | Minolta Co., Ltd. | Glass-ceramic composition for recording disk substrate |
| US6583077B1 (en) | 1999-07-14 | 2003-06-24 | Minolta Co., Ltd. | Glass-ceramic composition for recording disk substrate |
| US6583078B1 (en) | 1999-07-14 | 2003-06-24 | Minolta Co., Ltd. | Glass-ceramic composition for recording disk substrate |
| US6593259B1 (en) | 1999-07-14 | 2003-07-15 | Minolta Co., Ltd. | Glass-ceramic composition for recording disk substrate |
| US6458730B1 (en) | 1999-07-14 | 2002-10-01 | Minolta Co., Ltd. | Glass-ceramic composition for recording disk substrate |
| US6596659B1 (en) | 1999-07-14 | 2003-07-22 | Minolta Co., Ltd. | Glass-ceramic composition for recording disk substrate |
| US6610620B1 (en) | 1999-07-14 | 2003-08-26 | Minolta Co., Ltd. | Glass-ceramic composition for recording disk substrate |
| US6627567B1 (en) | 1999-07-14 | 2003-09-30 | Minolta Co., Ltd. | Glass-ceramic composition for recording disk substrate |
| US6284340B1 (en) | 1999-09-29 | 2001-09-04 | Ngk Insulators, Ltd. | Crystallized glass, magnetic disc substrate and magnetic disc |
| US6635591B2 (en) | 2000-04-03 | 2003-10-21 | Minolta Co., Ltd. | Glass composition for crystallized glass |
| US6642161B2 (en) | 2000-04-03 | 2003-11-04 | Minolta Co., Ltd. | Glass composition for crystallized glass |
| US6642162B2 (en) | 2000-04-03 | 2003-11-04 | Minolta Co., Ltd. | Glass composition for crystallized glass |
| US6645888B2 (en) | 2000-04-03 | 2003-11-11 | Minolta Co., Ltd. | Glass composition for crystallized glass |
| US6645892B2 (en) | 2000-04-03 | 2003-11-11 | Minolta Co., Ltd. | Glass composition for crystallized glass |
| US6645889B2 (en) | 2000-04-03 | 2003-11-11 | Minolta Co., Ltd. | Glass composition for crystallized glass |
| US6645890B2 (en) | 2000-04-03 | 2003-11-11 | Minolta Co., Ltd. | Glass composition for crystallized glass |
| US6645891B2 (en) | 2000-04-03 | 2003-11-11 | Minolta Co., Ltd. | Glass composition for crystallized glass |
| US6649549B2 (en) | 2000-04-03 | 2003-11-18 | Minolta Co., Ltd. | Glass composition for crystallized glass |
| US7589038B2 (en) | 2005-10-07 | 2009-09-15 | Ohara Inc. | Inorganic composition |
| JP2015504399A (en) * | 2011-10-14 | 2015-02-12 | イフォクレール ヴィヴァデント アクチェンゲゼルシャフトＩｖｏｃｌａｒ Ｖｉｖａｄｅｎｔ ＡＧ | Lithium silicate glass ceramic and lithium silicate glass containing divalent metal oxide |
| US9232989B2 (en) | 2011-10-14 | 2016-01-12 | Ivoclar Vivadent Ag | Lithium silicate glass ceramic and lithium silicate glass comprising a divalent metal oxide |
| US9776912B2 (en) | 2011-10-14 | 2017-10-03 | Ivoclar Vivadent Ag | Lithium silicate glass ceramic and glass with divalent metal oxide |
| JP2017214286A (en) * | 2011-10-14 | 2017-12-07 | イフォクレール ヴィヴァデント アクチェンゲゼルシャフトＩｖｏｃｌａｒ Ｖｉｖａｄｅｎｔ ＡＧ | Lithium silicate glass ceramics and lithium silicate glasses comprising divalent metal oxide |
| US10358380B2 (en) | 2011-10-14 | 2019-07-23 | Ivoclar Vivadent Ag | Lithium silicate glass ceramic and glass with divalent metal oxide |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3131138B2 (en) | 2001-01-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP3131138B2 (en) | Crystallized glass substrate for magnetic disk | |
| KR100188901B1 (en) | A glass-ceramic substrate for a magnetic disk | |
| JP2799544B2 (en) | Crystallized glass for information recording disks | |
| JP2516553B2 (en) | Crystallized glass for magnetic disk and manufacturing method thereof | |
| KR100329000B1 (en) | High rigidity glass-ceramic substrate for a magnetic information storage medium | |
| US5868953A (en) | Method for manufacturing a magnetic disk substrate | |
| US5567217A (en) | Method for manufacturing a crystalized glass magnetic disk substrate | |
| JP3219705B2 (en) | Glass ceramic substrate for magnetic information storage media | |
| JPH11314939A (en) | Glass ceramic substrate for magnetic information record medium | |
| JPH1116143A (en) | Glass ceramic substrate for magnetic information recording medium | |
| KR20070038908A (en) | Inorganic composition | |
| JPH1116142A (en) | Glass ceramic substrate for magnetic information recording medium | |
| US6034011A (en) | Glass-ceramic substrate for a magnetic head and a method for manufacturing the same | |
| US6703332B2 (en) | Glass-ceramic for substrate of magnetic disk having higher strength and process for the production of the same | |
| JP3420192B2 (en) | Glass ceramics | |
| JP4730995B2 (en) | Glass ceramics | |
| JPH0935234A (en) | Substrate for magnetic disk and its production | |
| JP3022524B1 (en) | High-rigidity glass ceramic substrate for information magnetic storage media | |
| JP2000119042A (en) | Glass ceramic substrate for magnetic information recording medium | |
| US6191058B1 (en) | Glass-ceramic substrate for a magnetic disk | |
| JP3011703B1 (en) | High-rigidity glass ceramic substrate for information magnetic storage media | |
| JP3219701B2 (en) | Glass ceramic substrate for magnetic information storage medium and method of manufacturing the same | |
| JP3152905B2 (en) | Crystallized glass substrate for magnetic disk | |
| JP2628460B2 (en) | Magnetic disk substrate and method of manufacturing the same | |
| JP4266095B2 (en) | Glass ceramics |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |