JP4218176B2 - Glass composition - Google Patents

Glass composition Download PDF

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Publication number
JP4218176B2
JP4218176B2 JP2000100822A JP2000100822A JP4218176B2 JP 4218176 B2 JP4218176 B2 JP 4218176B2 JP 2000100822 A JP2000100822 A JP 2000100822A JP 2000100822 A JP2000100822 A JP 2000100822A JP 4218176 B2 JP4218176 B2 JP 4218176B2
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Prior art keywords
less
glass
crystal
exceeds
improved
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JP2001287935A (en
Inventor
英喜 長田
博 遊亀
登史晴 森
秀樹 河合
和彦 石丸
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Konica Minolta Opto Inc
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Konica Minolta Opto Inc
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    • CCHEMISTRY; METALLURGY
    • C03GLASS; MINERAL OR SLAG WOOL
    • C03CCHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C10/00Devitrified glass ceramics, i.e. glass ceramics having a crystalline phase dispersed in a glassy phase and constituting at least 50% by weight of the total composition
    • C03C10/0036Devitrified glass ceramics, i.e. glass ceramics having a crystalline phase dispersed in a glassy phase and constituting at least 50% by weight of the total composition containing SiO2, Al2O3 and a divalent metal oxide as main constituents
    • C03C10/0045Devitrified glass ceramics, i.e. glass ceramics having a crystalline phase dispersed in a glassy phase and constituting at least 50% by weight of the total composition containing SiO2, Al2O3 and a divalent metal oxide as main constituents containing SiO2, Al2O3 and MgO as main constituents

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Dispersion Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Glass Compositions (AREA)

Description

【0001】
【発明の属する技術分野】
本発明は結晶化ガラス組成物に関する。さらに詳しくは、結晶化ガラス磁気ディスクの組成に関する。
【0002】
【従来の技術】
従来、磁気ディスク用の基板としては、アルミニウム基板、ガラス基板等が実用化されている。中でもガラス基板は、表面の平滑性や機械的強度が優れていることから、最も注目されている。そのようなガラス基板としては、ガラス基板表面をイオン交換で強化した化学強化ガラス基板や、基板に結晶成分を析出させて結合の強化を図る結晶化ガラス基板が知られている。
【0003】
ところで最近の基板に対する性能の要求は、日に日に厳しくなってきており、とくに高速回転時のたわみやそりに直接的に関わる強度に対する性能の向上が求められている。これは基板材料のヤング率によって表すことができ、数値が高ければ高いほど望ましい。
【0004】
例えば特開平11−322362に示される組成においては、ヤング率は130以上を達成している。しかし、上記先行技術においては熱処理温度が1次処理温度で800度、2次処理温度で1000度と非常に高く、製造が困難である。
【0005】
【発明が解決しようとする課題】
したがって最近は高いヤング率を達成しながら、生産性の向上が求めらることになる。そこで本発明は、ガラスのヤング率が向上し、さらに生産性の高いを組成を提供することを目的とする。
【0006】
【課題を解決するための手段】
上記目的を達成するために請求項1に記載された発明は、結晶化ガラス組成物であって、主成分の組成範囲を、
SiO2が35wt%以上で且つ 50wt%以下、
Al23が5wt%以上で且つ 30wt%以下、
MgOが10wt%以上で且つ 30wt%以下、
TiO2が5wt%以上で且つ 20wt%以下、
Li2Oが5.2wt%以上で且つ 6.8wt%以下、
Sb23が0.1wt%以上で且つ 9wt%以下とし
主析出結晶相がクリノエンスタタイトであることを特徴とする。
【0007】
【発明の実施の形態】
以下、本発明の実施形態について説明する。
本発明に係る実施形態のガラス基板は、主成分の組成範囲が、SiO2が35wt%以上で且つ50wt%以下、Al23が5wt%以上で且つ30wt%以下、MgOが10wt%以上で且つ30wt%以下、TiO2が5wt%以上で且つ20wt%以下、Li2Oが5.2wt%以上で且つ6.8wt%以下、であることを特徴としている。
【0008】
SiO2はガラス形成酸化物のため組成比が35wt%より少ないと、溶融性が悪くなり、50wt%を越えるとガラスとして安定状態になるため、結晶が析出しにくくなる。
【0009】
Al23はガラス中間酸化物であり、熱処理によって析出する結晶相であるマグネシウムアルミニウム系結晶の構成成分である。組成比が5wt%より少ないと析出結晶が少なく、強度が得られず、30wt%を越えると溶融温度が高くなり失透しやすくなる。
【0010】
MgOは融剤であり、それを加えているため粒状の結晶を凝集させ結晶粒子塊を形成する。ただし、組成比が10wt%より少ないと作業温度幅が狭くなりう、ガラスマトリクス相の化学的耐久性が向上しない。30wt%を越えると、他の結晶相が析出して求める強度を得ることが難しくなる。
【0011】
TiOは結晶核剤としてマグネシウムシリケート系結晶析出には不可欠な成分である。また融剤として働くため生産時の安定性が向上している。組成比が5wt%より少ないと溶融性が悪くなると共に、結晶成長がしにくくなり、20wt%を越えると結晶化が急激に促進され、結晶化状態の制御が困難となり析出結晶の粗大化、結晶相の不均質が発生し、微細で均質な結晶構造が得られなくなり、研磨加工においてディスク基板として必要な平滑面が得られなくなる。さらに溶融成形時に失透しやすくなり、生産性が低下する。
【0012】
Li2Oは融剤として働くため生産時の安定性が向上している。組成比が5.2wt%より少ないと溶融性が悪くなり、6.8wt%を越えると、また研磨−洗浄工程における安定性が悪くなる。
【0013】
以下製造方法を説明する。最終的に生成されるガラス基板の主成分の組成を含む原料を所定の割合にて充分に混合し、これを白金るつぼに入れ溶融を行う。溶融後金型に流し概略の形状を形成する。これを室温までアニールする。続いて、500〜680度の1次熱処理温度と1次処理時間により保持し(熱処理)、結晶核生成が行われる。引き続き、680〜800度の2次熱処理温度と2次処理時間により保持し結晶核成長を行う。これを除冷することにより目的とする結晶化ガラスが得られる。
【0014】
さらにこれを所望の形状、厚さに研磨等の加工を施すことにより、ディスク基板として利用できる。
【0015】
以上の製造方法によって得られたガラス基板は、主成分の組成範囲が、SiO2が35wt%以上で且つ50wt%以下、Al23が5wt%以上で且つ30wt%以下、MgOが10wt%以上で且つ30wt%以下、TiO2が5wt%以上で且つ20wt%以下、Li2Oが5.2wt%以上で且つ6.8wt%以下、とするために、非常に高いヤング率と高い生産性を得ることが可能となった。
【0016】
また以下の組成を適正な範囲において加えることにより、よりよい性能が得られる。
【0017】
融剤として働くZnOを加えているため均一な結晶析出を補助する。ただし、組成比が0.1wt%より少ないと十分な結晶均質化の改善がなされない。22wt%を越えると、ガラスが安定となり結晶化が抑制され、求める強度が得られにくくなる。
【0018】
融剤として働くP2O5は、シリケート系結晶を析出させる核形成剤であり、ガラス全体に結晶を均一に析出させるために重要な成分である。組成比が0.1wt%より少ないと十分な結晶核が形成されにくくなり、結晶粒子が粗大化したり結晶が不均質に析出し、微細で均質な結晶構造が得られにくくなり、研磨加工においてディスク基板として必要な平滑面が得られなくなる。5.0wt%を越えると、溶融時の炉剤に対する反応性が増し、また失透性も強くなることから溶融成形時の生産性が低下する。また化学的耐久性が低下し、磁気膜に影響を与える恐れがあると共に、研磨−洗浄工程における安定性が悪くなる。
【0019】
ガラス修飾酸化物として働くZrO2を加えているためガラスの結晶核剤が有効に機能する。組成比が0.1wt%より少ないと十分な結晶核が形成されなくにくくなり、結晶粒子が粗大化したり結晶が不均質に析出し、微細で均質な結晶構造が得られなくなり、研磨加工においてディスク基板として必要な平滑面が得られなくなる。また化学的耐久性および耐マイグレーションが低下し、磁気膜に影響を与える恐れがあるとともに、研磨−洗浄工程において安定性が悪くなる。また12wt%を越えると溶融温度が高くなり、また失透しやすくなり溶融成形が困難となる。また析出結晶相が変化し求める特性が得られにくくなる。
【0020】
融剤として働くCaOを加えているため均一な結晶析出を補助する。ただし、組成比が0.1wt%より少ないと十分な結晶均質化の改善がなされない。9wt%を越えると、化学的耐久性を向上させることができなくなる。
【0021】
融剤として働くNb25を加えているため結晶核剤物質が増加することになる。ただし、組成比が0.1wt%より少ないと十分な剛性の向上がなされない。9wt%を越えると、ガラスの結晶化が不安定となり、析出結晶相を制御できなくなり、求める特性が得られにくくなる。
【0022】
融剤として働くTa25を加えているため溶融性、強度を向上させ、またガラスマトリクス相の化学的耐久性を向上させる。ただし、組成比が0.1wt%より少ないと十分な剛性の向上がなされない。9wt%を越えると、ガラスの結晶化が不安定となり、析出結晶相を制御できなくなり、求める特性が得られにくくなる。
【0023】
融剤として働くK2Oを加えているため生産時の安定性が向上している。ただし、組成比が0.1wt%より少ないと十分な溶融性改善がなされない。9wt%を越えると、ガラスが安定となり結晶化が抑制され、また化学的耐久性が低下し、磁気膜に影響を与える恐れがあると共に、研磨−洗浄工程における安定性が悪くなる。
【0024】
フォーマーとして働くB23を加えているためガラスの分相を促し、結晶析出および成長を促進させる。ただし、組成比が0.1wt%より少ないと十分な溶融性改善がなされない。9wt%を越えると、ガラスが失透しやすくなり成形が困難になると共に、結晶が粗大化し微細な結晶が得られなくなる。
【0025】
融剤として働くY23を加えているため剛性が向上している。ただし、組成比が0.1wt%より少ないと十分な剛性向上が得られない。9wt%を越えると、結晶析出が抑制され、十分な結晶化度が得られず、所望の特性が達成されない。
【0026】
清澄剤として働くSb23を加えているため生産時の安定性が向上している。ただし、組成比が0.1wt%より少ないと十分な清澄効果が得られなくなり、生産性が低下する。9wt%を越えると、ガラスの結晶化が不安定となり析出結晶相を制御できなくなり、求める特性が得られにくくなる。
【0027】
清澄剤として働くAs23を加えているため生産時の安定性が向上している。ただし、組成比が0.1wt%より少ないと十分な清澄効果が得られなくなり、生産性が低下する。9wt%を越えると、ガラスの結晶化が不安定となり析出結晶相を制御できなくなり、求める特性が得られにくくなる。
【0028】
【実施例】
以下に実施例をあげて本発明を詳細に説明するが、本発明はこれらの実施例に限定されるものではない。表1〜4には実施例1〜6、参考例1〜27のガラス組成を重量%で示した。これらの数値に従って、先述した製造方法によりガラス基板を得た。
【0029】
【表1】

Figure 0004218176
C1 MgSiO3:クリノエンスタタイト
C2 MgSiO3:エンスタタイト
M1 (Mg,Al)SiO3:マグネシウム・アルミニウム・シリケート
Z1 Zn2Ti3O8:チタン酸亜鉛
Z2 Zn2TiO4:チタン酸亜鉛
【0030】
【表2】
Figure 0004218176
【0031】
【表3】
Figure 0004218176
【0032】
【表4】
Figure 0004218176
【0033】
【発明の効果】
本発明によると、ヤング率が110以上かつ生産性の高いガラス基板を得ることができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a crystallized glass composition. More specifically, it relates to the composition of a crystallized glass magnetic disk.
[0002]
[Prior art]
Conventionally, aluminum substrates, glass substrates, and the like have been put to practical use as magnetic disk substrates. Among them, the glass substrate has received the most attention because of its excellent surface smoothness and mechanical strength. As such a glass substrate, a chemically strengthened glass substrate in which the surface of the glass substrate is strengthened by ion exchange, and a crystallized glass substrate that strengthens bonding by depositing a crystal component on the substrate are known.
[0003]
By the way, performance requirements for recent substrates are becoming stricter day by day, and in particular, there is a demand for improvement in performance for strength directly related to deflection and warpage during high-speed rotation. This can be expressed by the Young's modulus of the substrate material, and the higher the value, the more desirable.
[0004]
For example, in the composition disclosed in JP-A-11-322362, the Young's modulus is 130 or more. However, in the above prior art, the heat treatment temperature is very high at 800 degrees for the primary treatment temperature and 1000 degrees for the secondary treatment temperature, and it is difficult to manufacture.
[0005]
[Problems to be solved by the invention]
Therefore, recently, improvement in productivity is demanded while achieving a high Young's modulus. Accordingly, an object of the present invention is to provide a composition having an improved Young's modulus of glass and high productivity.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the invention described in claim 1 is a crystallized glass composition, wherein the composition range of the main component is
SiO 2 is 35 wt% or more and 50 wt% or less,
Al 2 O 3 is 5 wt% or more and 30 wt% or less,
MgO is 10 wt% or more and 30 wt% or less,
TiO 2 is 5 wt% or more and 20 wt% or less,
Li 2 O is 5.2 wt% or more and 6.8 wt% or less,
Sb 2 O 3 is 0.1 wt% or more and 9 wt% or less ,
The main precipitation crystal phase is clinoenstatite .
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described.
In the glass substrate of the embodiment according to the present invention, the composition range of the main component is that SiO 2 is 35 wt% or more and 50 wt% or less, Al 2 O 3 is 5 wt% or more and 30 wt% or less, and MgO is 10 wt% or more. 30 wt% or less, TiO 2 is 5 wt% or more and 20 wt% or less, and Li 2 O is 5.2 wt% or more and 6.8 wt% or less.
[0008]
Since SiO 2 is a glass-forming oxide, if the composition ratio is less than 35 wt%, the meltability becomes poor, and if it exceeds 50 wt%, the glass becomes stable and the crystals are difficult to precipitate.
[0009]
Al 2 O 3 is a glass intermediate oxide and is a constituent component of a magnesium aluminum-based crystal that is a crystal phase precipitated by heat treatment. When the composition ratio is less than 5 wt%, the number of precipitated crystals is small and the strength cannot be obtained, and when it exceeds 30 wt%, the melting temperature becomes high and the glass tends to devitrify.
[0010]
MgO is a flux, and since it is added, the granular crystals are aggregated to form a crystal particle lump. However, when the composition ratio is less than 10 wt%, the working temperature range is narrowed, and the chemical durability of the glass matrix phase is not improved. When it exceeds 30 wt%, it becomes difficult to obtain the required strength by precipitation of other crystal phases.
[0011]
TiO is an essential component for the precipitation of magnesium silicate crystals as a crystal nucleating agent. Moreover, since it acts as a flux, stability during production is improved. If the composition ratio is less than 5 wt%, the meltability is deteriorated and crystal growth is difficult, and if it exceeds 20 wt%, crystallization is rapidly promoted, and the control of the crystallization state becomes difficult, resulting in coarsening of the precipitated crystals, crystals Phase heterogeneity occurs, and a fine and homogeneous crystal structure cannot be obtained, and a smooth surface required as a disk substrate in polishing processing cannot be obtained. Furthermore, it becomes easy to devitrify at the time of melt molding, and productivity is lowered.
[0012]
Since Li 2 O works as a flux, stability during production is improved. When the composition ratio is less than 5.2 wt%, the meltability is deteriorated, and when it exceeds 6.8 wt%, the stability in the polishing-cleaning process is deteriorated.
[0013]
A manufacturing method will be described below. The raw material containing the composition of the main component of the finally produced glass substrate is sufficiently mixed at a predetermined ratio, and this is put into a platinum crucible and melted. After melting, it is poured into a mold to form a rough shape. This is annealed to room temperature. Subsequently, crystal nucleation is performed by maintaining the temperature at a primary heat treatment temperature of 500 to 680 degrees and a primary treatment time (heat treatment). Subsequently, crystal nucleus growth is performed by holding at a secondary heat treatment temperature of 680 to 800 degrees and a secondary treatment time. The objective crystallized glass can be obtained by removing the temperature.
[0014]
Furthermore, it can be used as a disk substrate by subjecting it to a desired shape and thickness, such as polishing.
[0015]
The glass substrate obtained by the above manufacturing method has a composition range of main components of SiO 2 of 35 wt% or more and 50 wt% or less, Al 2 O 3 of 5 wt% or more and 30 wt% or less, and MgO of 10 wt% or more. And 30 wt% or less, TiO 2 of 5 wt% or more and 20 wt% or less, and Li 2 O of 5.2 wt% or more and 6.8 wt% or less. It became possible to get.
[0016]
Moreover, a better performance can be obtained by adding the following composition in an appropriate range.
[0017]
Since ZnO acting as a flux is added, uniform crystal precipitation is assisted. However, if the composition ratio is less than 0.1 wt%, sufficient crystal homogenization cannot be improved. If it exceeds 22 wt%, the glass becomes stable, crystallization is suppressed, and the required strength is hardly obtained.
[0018]
P2O5 acting as a flux is a nucleating agent for precipitating silicate crystals, and is an important component for precipitating crystals uniformly over the entire glass. When the composition ratio is less than 0.1 wt%, it is difficult to form sufficient crystal nuclei, and crystal grains become coarse or crystals are deposited inhomogeneously, making it difficult to obtain a fine and homogeneous crystal structure. A smooth surface required as a substrate cannot be obtained. If it exceeds 5.0 wt%, the reactivity to the furnace agent at the time of melting will increase, and the devitrification will become strong, so the productivity at the time of melt molding will decrease. Further, the chemical durability is lowered, which may affect the magnetic film, and the stability in the polishing-cleaning process is deteriorated.
[0019]
Since ZrO 2 acting as a glass modifying oxide is added, the glass nucleating agent functions effectively. If the composition ratio is less than 0.1 wt%, it becomes difficult to form sufficient crystal nuclei, crystal grains become coarse or crystals are heterogeneously precipitated, and a fine and homogeneous crystal structure cannot be obtained. A smooth surface required as a substrate cannot be obtained. In addition, chemical durability and migration resistance are lowered, which may affect the magnetic film, and stability is deteriorated in the polishing-cleaning process. On the other hand, if it exceeds 12 wt%, the melting temperature becomes high, and devitrification easily occurs, so that melt molding becomes difficult. In addition, the precipitated crystal phase changes, making it difficult to obtain the desired characteristics.
[0020]
Since CaO acting as a flux is added, uniform crystal precipitation is assisted. However, if the composition ratio is less than 0.1 wt%, sufficient crystal homogenization cannot be improved. If it exceeds 9 wt%, the chemical durability cannot be improved.
[0021]
Since Nb 2 O 5 acting as a flux is added, the crystal nucleating agent substance increases. However, if the composition ratio is less than 0.1 wt%, sufficient rigidity cannot be improved. If it exceeds 9 wt%, the crystallization of the glass becomes unstable, and the precipitated crystal phase cannot be controlled, making it difficult to obtain the desired characteristics.
[0022]
Since Ta 2 O 5 acting as a flux is added, the melting property and strength are improved, and the chemical durability of the glass matrix phase is improved. However, if the composition ratio is less than 0.1 wt%, sufficient rigidity cannot be improved. If it exceeds 9 wt%, the crystallization of the glass becomes unstable, and the precipitated crystal phase cannot be controlled, making it difficult to obtain the desired characteristics.
[0023]
Since K 2 O acting as a flux is added, stability during production is improved. However, if the composition ratio is less than 0.1 wt%, sufficient meltability cannot be improved. If it exceeds 9 wt%, the glass becomes stable and crystallization is suppressed, the chemical durability is lowered, the magnetic film may be affected, and the stability in the polishing-cleaning process is deteriorated.
[0024]
Since B 2 O 3 acting as a former is added, glass phase separation is promoted, and crystal precipitation and growth are promoted. However, if the composition ratio is less than 0.1 wt%, sufficient meltability cannot be improved. If it exceeds 9 wt%, the glass tends to be devitrified, making it difficult to mold, and the crystals become coarse and fine crystals cannot be obtained.
[0025]
Since Y 2 O 3 acting as a flux is added, the rigidity is improved. However, when the composition ratio is less than 0.1 wt%, sufficient rigidity cannot be obtained. If it exceeds 9 wt%, crystal precipitation is suppressed, sufficient crystallinity cannot be obtained, and desired characteristics cannot be achieved.
[0026]
Since Sb 2 O 3 acting as a fining agent is added, the stability during production is improved. However, if the composition ratio is less than 0.1 wt%, a sufficient clarification effect cannot be obtained and productivity is lowered. If it exceeds 9 wt%, the crystallization of the glass becomes unstable, and the precipitated crystal phase cannot be controlled, making it difficult to obtain the desired characteristics.
[0027]
Since As 2 O 3 that works as a fining agent is added, stability during production is improved. However, if the composition ratio is less than 0.1 wt%, a sufficient clarification effect cannot be obtained and productivity is lowered. If it exceeds 9 wt%, the crystallization of the glass becomes unstable, and the precipitated crystal phase cannot be controlled, making it difficult to obtain the desired characteristics.
[0028]
【Example】
EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. Tables 1 to 4 show the glass compositions of Examples 1 to 6 and Reference Examples 1 to 27 in terms of% by weight. According to these numerical values, a glass substrate was obtained by the production method described above.
[0029]
[Table 1]
Figure 0004218176
C1 MgSiO 3 : Clinoenstatite
C2 MgSiO 3 : Enstatite
M1 (Mg, Al) SiO 3 : Magnesium, aluminum, silicate
Z1 Zn 2 Ti 3 O 8 : Zinc titanate
Z2 Zn 2 TiO 4 : Zinc titanate [0030]
[Table 2]
Figure 0004218176
[0031]
[Table 3]
Figure 0004218176
[0032]
[Table 4]
Figure 0004218176
[0033]
【The invention's effect】
According to the present invention, a glass substrate having a Young's modulus of 110 or more and high productivity can be obtained.

Claims (1)

主成分の組成範囲を、
SiO2が35wt%以上で且つ 50wt%以下、
Al23が5wt%以上で且つ 30wt%以下、
MgOが10wt%以上で且つ 30wt%以下、
TiO2が5wt%以上で且つ 20wt%以下、
Li2Oが5.2wt%以上で且つ 6.8wt%以下、
Sb23が0.1wt%以上で且つ 9wt%以下とし、
主析出結晶相がクリノエンスタタイトであることを特徴とする結晶化ガラス組成物。
The composition range of the main component
SiO 2 is 35 wt% or more and 50 wt% or less,
Al 2 O 3 is 5 wt% or more and 30 wt% or less,
MgO is 10 wt% or more and 30 wt% or less,
TiO 2 is 5 wt% or more and 20 wt% or less,
Li 2 O is 5.2 wt% or more and 6.8 wt% or less,
Sb 2 O 3 is 0.1 wt% or more and 9 wt% or less ,
A crystallized glass composition characterized in that a main precipitated crystal phase is clinoenstatite.
JP2000100822A 2000-04-03 2000-04-03 Glass composition Expired - Fee Related JP4218176B2 (en)

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JP4218176B2 true JP4218176B2 (en) 2009-02-04

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Publication number Priority date Publication date Assignee Title
JP4795522B2 (en) * 2000-10-24 2011-10-19 株式会社オハラ High rigidity glass ceramic substrate and information magnetic storage medium disk

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