JP5396859B2 - Glass for information recording medium substrate - Google Patents
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- JP5396859B2 JP5396859B2JP2008545441AJP2008545441AJP5396859B2JP 5396859 B2JP5396859 B2JP 5396859B2JP 2008545441 AJP2008545441 AJP 2008545441AJP 2008545441 AJP2008545441 AJP 2008545441AJP 5396859 B2JP5396859 B2JP 5396859B2
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- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03C—CHEMICAL 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
- C03C3/00—Glass compositions
- C03C3/04—Glass compositions containing silica
- C03C3/076—Glass compositions containing silica with 40% to 90% silica, by weight
- C03C3/083—Glass compositions containing silica with 40% to 90% silica, by weight containing aluminium oxide or an iron compound
- C03C3/085—Glass compositions containing silica with 40% to 90% silica, by weight containing aluminium oxide or an iron compound containing an oxide of a divalent metal
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03C—CHEMICAL 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
- C03C3/00—Glass compositions
- C03C3/04—Glass compositions containing silica
- C03C3/076—Glass compositions containing silica with 40% to 90% silica, by weight
- C03C3/083—Glass compositions containing silica with 40% to 90% silica, by weight containing aluminium oxide or an iron compound
- C03C3/085—Glass compositions containing silica with 40% to 90% silica, by weight containing aluminium oxide or an iron compound containing an oxide of a divalent metal
- C03C3/087—Glass compositions containing silica with 40% to 90% silica, by weight containing aluminium oxide or an iron compound containing an oxide of a divalent metal containing calcium oxide, e.g. common sheet or container glass
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/62—Record carriers characterised by the selection of the material
- G11B5/73—Base layers, i.e. all non-magnetic layers lying under a lowermost magnetic recording layer, e.g. including any non-magnetic layer in between a first magnetic recording layer and either an underlying substrate or a soft magnetic underlayer
- G11B5/739—Magnetic recording media substrates
- G11B5/73911—Inorganic substrates
- G11B5/73921—Glass or ceramic substrates
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Ceramic Engineering (AREA)
- Inorganic Chemistry (AREA)
- Glass Compositions (AREA)
- Magnetic Record Carriers (AREA)
Description
Translated fromJapanese本発明は、磁気ディスク用ガラス基板などの情報記録媒体用ガラス基板および情報記録媒体用ガラス基板に好適な情報記録媒体基板用ガラスに関する。 The present invention relates to a glass substrate for an information recording medium such as a glass substrate for a magnetic disk and a glass for an information recording medium substrate suitable for a glass substrate for an information recording medium.
情報記録媒体用基板、特に磁気ディスク（ハードディスク）用基板としてガラス基板が広く用いられており、磁気ディスク用ガラス基板としては化学強化されたものと化学強化されていないものが存在する。
化学強化されていない磁気ディスク用ガラス基板としては、ＳｉＯ２−Ａｌ２Ｏ３−Ｌｉ２Ｏ−Ｎａ２Ｏ−Ｋ２Ｏ−ＴｉＯ２系ガラスからなるものが提案されている（特許文献１参照）。A glass substrate is widely used as an information recording medium substrate, particularly a magnetic disk (hard disk) substrate, and there are chemically strengthened and non-chemically strengthened glass substrates for magnetic disks.
As a glass substrate for a magnetic disk that is not chemically strengthened, a glass substrate made of SiO2 —Al2 O3 —Li2 O—Na2 O—K2 O—TiO2 glass has been proposed (see Patent Document 1). ).
特許文献１のガラスはガラス転移点（Ｔｇ）が最高でも５６７℃であり、このガラスを磁気ディスク用ガラス基板に用いた場合、ガラス基板上に磁性層を形成する際の温度を高くすることができず、その結果磁性層の保磁力を大きくすることができないおそれがあるものであった。
本発明はこのような問題を解決できる、情報記録媒体基板用ガラスおよびこれを用いた情報記録媒体用ガラス基板の提供を目的とする。The glass of Patent Document 1 has a maximum glass transition point (Tg) of 567 ° C. When this glass is used for a glass substrate for a magnetic disk, the temperature at which a magnetic layer is formed on the glass substrate may be increased. As a result, the coercive force of the magnetic layer may not be increased.
An object of the present invention is to provide a glass for an information recording medium substrate and a glass substrate for an information recording medium using the same, which can solve such problems.
本発明は、下記酸化物基準のモル％表示で、ＳｉＯ２を５５〜７５％、Ａｌ２Ｏ３を１〜１２％、ＭｇＯを２〜１５％、ＣａＯを０〜１．５％、Ｎａ２ＯまたはＫ２Ｏを合計で１〜２０％、ＴｉＯ２を０〜８％含有し、ＢａＯを含有する場合その含有量は２％以下であり、Ｌｉ２Ｏを含有する場合その含有量は１％以下であり、ＺｒＯ２を含有する場合その含有量は０．５％以下である情報記録媒体基板用ガラスを提供する。
また、前記情報記録媒体基板用ガラスからなる情報記録媒体用ガラス基板を提供する。The present invention is expressed in terms of mol% based on the following oxides: SiO2 is 55 to 75%, Al2 O3 is 1 to 12%, MgO is 2 to 15%, CaO is 0 to 1.5%, Na2 The total content of O or K2 O is 1 to 20%, the content of TiO2 is 0 to 8%, and the content of BaO is 2% or less, and the content of Li2 O is 1 or less. %, And when ZrO2 is contained, the content of the glass for an information recording medium substrate is 0.5% or less.
Moreover, the glass substrate for information recording media which consists of said glass for information recording media substrates is provided.
本発明によれば、Ｔｇが６００℃以上である情報記録媒体基板用ガラスを得ることができる。
また、強度が高い、密度が小さい、またはフロート成形が可能な情報記録媒体基板用ガラスまたは情報記録媒体用ガラス基板を得ることができる。
また、耐候性が高い情報記録媒体用ガラス基板を得ることができるので、在庫中にガラス基板の表面性状が著しく変化し、前記基板上に形成される下地膜、磁性膜、保護膜等の膜がはがれやすくなるという問題が起こりにくくなる。
また、化学強化処理を行うことなく情報記録媒体用ガラス基板を製造できるので、工程を減らすことができ、また化学強化処理後の基板表面への汚れ付着の問題を解決できる。According to the present invention, a glass for an information recording medium substrate having a Tg of 600 ° C. or higher can be obtained.
Further, it is possible to obtain an information recording medium substrate glass or an information recording medium glass substrate having high strength, low density, or float forming.
In addition, since a glass substrate for an information recording medium having high weather resistance can be obtained, the surface properties of the glass substrate change remarkably during inventory, and films such as a base film, a magnetic film, and a protective film formed on the substrate. The problem of easy peeling is less likely to occur.
Moreover, since the glass substrate for information recording media can be manufactured without performing the chemical strengthening treatment, the number of processes can be reduced, and the problem of dirt adhesion to the substrate surface after the chemical strengthening treatment can be solved.
本発明の情報記録媒体基板用ガラス（以下、本発明のガラスという。）のＴｇは６００℃以上であることが好ましい。６００℃未満では磁性層形成熱処理温度を充分高くすることができず、磁性層の保磁力増加が困難になるおそれがある。より好ましくは６１０℃以上、特に好ましくは６２０℃以上である。 The Tg of the glass for an information recording medium substrate of the present invention (hereinafter referred to as the glass of the present invention) is preferably 600 ° C. or higher. If it is less than 600 ° C., the heat treatment temperature for forming the magnetic layer cannot be sufficiently increased, and it may be difficult to increase the coercive force of the magnetic layer. More preferably, it is 610 degreeC or more, Most preferably, it is 620 degreeC or more.
本発明のガラスの５０〜３５０℃における平均線膨張係数（α）は７０×１０−７／℃以上であることが好ましい。７０×１０−７／℃未満では、基板に取り付けるハブの金属の熱膨張係数（典型的には７０×１０−７〜１００×１０−７／℃）との差が大きくなり、基板の割れが起こりやすくなる。より好ましくは７５×１０−７／℃以上、特に好ましくは８０×１０−７／℃以上である。また、αは典型的には９５×１０−７／℃以下である。It is preferable that the average linear expansion coefficient ((alpha)) in 50-350 degreeC of the glass of this invention is 70x10 <-7 > / degreeC or more. If it is less than 70 × 10−7 / ° C., the difference between the thermal expansion coefficient of the metal of the hub attached to the substrate (typically 70 × 10−7 to 100 × 10−7 / ° C.) becomes large, and the substrate cracks. It tends to happen. More preferably, it is 75 × 10−7 / ° C. or more, and particularly preferably 80 × 10−7 / ° C. or more. Α is typically 95 × 10−7 / ° C. or less.
本発明のガラスは、その液相温度をＴＬとし、粘度が１０４Ｐ（ポアズ）となる温度をＴ４とした場合、（ＴＬ−Ｔ４）は５０℃未満であることが好ましい。（ＴＬ−Ｔ４）が５０℃以上ではフロート成形が困難になるおそれがあり、より好ましくは４０℃未満、特に好ましくは３０℃未満である。
本発明のガラスの粘度が１０２Ｐとなる温度Ｔ２は１７００℃以下であることが好ましい。Ｔ２が１７００℃超ではガラスの溶解または清澄が困難になるおそれがある。In the glass of the present invention, when the liquidus temperature isTL and the temperature at which the viscosity is 104 P (poise) is T4 , (TL- T4 ) is preferably less than 50 ° C. If (TL -T4 ) is 50 ° C. or higher, float molding may be difficult, more preferably less than 40 ° C., and particularly preferably less than 30 ° C.
The temperature T2 at which the viscosity of the glass of the present invention becomes 102 P is preferably 1700 ° C. or lower. If T2 exceeds 1700 ° C., it may be difficult to dissolve or clarify the glass.
磁気ディスク用ガラス基板はノートブックパソコン等に用いられる２．５インチ基板（ガラス基板外径：６５ｍｍ）やポータブルＭＰ３プレーヤなどに用いられる１．８インチ基板（ガラス基板外径：４８ｍｍ）などに広く使用され、その市場は年々拡大しており、一方で低価格での供給が求められている。このようなガラス基板に使用されるガラスは、大量生産に適したものであることが好ましい。
板ガラスの大量生産はフロート法、フュージョン法、ダウンドロー法などの連続成形法により広く行われており、本発明のガラスは先に述べたように、たとえばフロート成形が可能なガラスとできるので大量生産に好適である。Glass substrates for magnetic disks are widely used for 2.5 inch substrates (outer diameter of glass substrate: 65 mm) used for notebook personal computers and 1.8 inch substrates (outer diameter of glass substrate: 48 mm) used for portable MP3 players, etc. The market is growing year by year, while low-cost supply is required. It is preferable that the glass used for such a glass substrate is suitable for mass production.
Mass production of sheet glass is widely performed by continuous molding methods such as the float method, fusion method, and downdraw method. As described above, the glass of the present invention can be produced in large quantities because it can be made, for example, glass that can be float molded. It is suitable for.
本発明のガラスの密度は２．５０ｇ／ｃｍ３以下であることが好ましく、より好ましくは２．４８ｇ／ｃｍ３以下、特に好ましくは２．４７ｇ／ｃｍ３以下である。Preferably the density of the glass of the present invention is 2.50 g / cm3 or less, more preferably 2.48 g / cm3 or less, particularly preferably 2.47 g / cm3 or less.
本発明の情報記録媒体用ガラス基板（以下、本発明のガラス基板という。）は本発明のガラスからなる、通常は円形のガラス板である。なお、情報記録媒体としては磁気ディスクが例示される。 The glass substrate for information recording media of the present invention (hereinafter referred to as the glass substrate of the present invention) is a generally circular glass plate made of the glass of the present invention. An example of the information recording medium is a magnetic disk.
本発明のガラス基板は、それを１２０℃、２気圧の水蒸気雰囲気に２０時間保持したとき、その表面に存在する、大きさが１０μｍ以上の付着物の数ＮＬが１個／ｃｍ２以下である、または、大きさが１μｍ以上１０μｍ未満の付着物の数ＮＳが１０５個／ｃｍ２以下であることが好ましい。ＮＬが１個／ｃｍ２超またはＮＳが１０５個／ｃｍ２超では、ガラス基板在庫中にガラス基板表面に付着物（白ヤケ）が発生し、ガラス基板上に形成される下地膜、磁性膜、保護膜等の膜がはがれやすくなる。この付着物は、空気中の水分や炭酸ガスの影響によりガラス基板に生成付着した反応生成物であると考えられ、拭いても除去できないものである。ＮＬはより好ましくは０．８個／ｃｍ２以下、特に好ましくは０．５個／ｃｍ２以下である。ＮＳはより好ましくは０．８×１０５個／ｃｍ２以下、特に好ましくは０．６×１０５個／ｃｍ２以下である。When the glass substrate of the present invention is held in a steam atmosphere at 120 ° C. and 2 atm for 20 hours, the number NL of deposits having a size of 10 μm or more present on the surface is 1 piece / cm2 or less. or, it is preferable that the size adheres the numberN S of less than 10μm or 1μm is 105 / cm2 or less. The NL is 1 / cm2 or greater thanN S 105 cells / cm2, greater than the base film which deposits on the surface of the glass substrate in the glass substrate stock (dimming) is generated, are formed on a glass substrate In addition, films such as magnetic films and protective films are easily peeled off. This deposit is considered to be a reaction product produced and adhered to the glass substrate due to the influence of moisture and carbon dioxide in the air, and cannot be removed by wiping. NL is more preferably 0.8 pieces / cm2 or less, particularly preferably 0.5 pieces / cm2 or less. NS is more preferably 0.8 × 105 / cm2 or less, particularly preferably 0.6 × 105 / cm2 or less.
本発明のガラスのクラック発生率は７０％以下であることが好ましい。７０％超ではガラス強度が不十分となる可能性がある。より好ましくは６０％以下、特に好ましくは５０％以下である。
前記クラック発生率は次のようにして求められる。すなわち、２３℃、相対湿度７０％に制御した室内において、厚さが１〜２ｍｍ、大きさが４ｃｍ×４ｃｍの鏡面研磨したガラス板の表面に荷重５００ｇでビッカース圧子を打ち込み、その４つの頂点から発生するクラック本数を測定する。この測定を１０回繰り返し、１００×（発生したクラック総本数）／４０をクラック発生率とする。
クラック発生率が小さいものはガラス表面にキズがつきにくいので応力集中が発生しにくく、弱い応力で脆性的破壊が起こることがなくなる、または減少する。The crack occurrence rate of the glass of the present invention is preferably 70% or less. If it exceeds 70%, the glass strength may be insufficient. More preferably, it is 60% or less, and particularly preferably 50% or less.
The crack occurrence rate is obtained as follows. That is, in a room controlled at 23 ° C. and a relative humidity of 70%, a Vickers indenter is driven with a load of 500 g on the surface of a mirror-polished glass plate having a thickness of 1 to 2 mm and a size of 4 cm × 4 cm. Measure the number of cracks generated. This measurement is repeated 10 times, and 100 × (total number of cracks generated) / 40 is defined as the crack occurrence rate.
When the crack generation rate is small, the glass surface is hardly scratched, so that stress concentration is difficult to occur, and brittle fracture does not occur or is reduced by weak stress.
本発明のガラスおよびガラス基板の製造方法は特に限定されず、各種方法を適用できる。たとえば、通常使用される各成分の原料を目標組成となるように調合し、これをガラス溶融窯で加熱溶融する。バブリング、撹拌、清澄剤の添加等によりガラスを均質化し、周知のフロート法、プレス法、フュージョン法またダウンドロー法などの方法により所定の厚さの板ガラスに成形し、徐冷後必要に応じて研削、研磨などの加工を行った後、所定の寸法・形状のガラス基板とされる。成形法としては、特に、大量生産に適したフロート法が好適である。また、フロート法以外の連続成形法、すなわち、フュージョン法、ダウンドロー法も好適である。 The method for producing the glass and glass substrate of the present invention is not particularly limited, and various methods can be applied. For example, the raw materials of each component normally used are prepared so as to have a target composition, and this is heated and melted in a glass melting kiln. Homogenize the glass by bubbling, stirring, adding a clarifying agent, etc., and forming it into a sheet glass of a predetermined thickness by methods such as the well-known float method, press method, fusion method or down draw method, and after slow cooling, as necessary After processing such as grinding and polishing, a glass substrate having a predetermined size and shape is obtained. As the molding method, a float method suitable for mass production is particularly suitable. Further, continuous molding methods other than the float method, that is, the fusion method and the downdraw method are also suitable.
次に、本発明のガラスの組成についてモル％表示を用いて説明する。
ＳｉＯ２はガラスの骨格を形成する成分であり、必須である。５５％未満では、ガラスにキズが付きやすくなる、またＴＬが上昇しガラスが不安定になる。好ましくは５８％以上、より好ましくは６０％以上、特に好ましくは６２％以上、典型的には６４％以上、より典型的には６５％以上である。７５％超では、高温粘性が上昇しガラスの溶解が困難となる。好ましくは７２％以下、より好ましくは７１％以下である。Next, the composition of the glass of the present invention will be described using mol% display.
SiO2 is a component that forms a glass skeleton and is essential. If it is less than 55%, the glass tends to be scratched, and theTL rises and the glass becomes unstable. Preferably it is 58% or more, more preferably 60% or more, particularly preferably 62% or more, typically 64% or more, more typically 65% or more. If it exceeds 75%, the high-temperature viscosity rises and it becomes difficult to melt the glass. Preferably it is 72% or less, More preferably, it is 71% or less.
Ａｌ２Ｏ３はＴｇを高くし、耐候性を高める効果を有し、必須である。１％未満では前記効果が小さい。好ましくは１．５％以上、より好ましくは２％以上、特に好ましくは２．５％以上である。１２％超では高温粘性が上昇しガラスの溶解が困難となり、またＴＬが高くなりすぎる。好ましくは１０％以下、より好ましくは８％以下、特に好ましくは７％以下、典型的には６．５％以下である。Al2 O3 has an effect of increasing Tg and improving weather resistance, and is essential. If it is less than 1%, the effect is small. Preferably it is 1.5% or more, More preferably, it is 2% or more, Most preferably, it is 2.5% or more. If it exceeds 12%, the high-temperature viscosity will increase, making it difficult to melt the glass, andTL will be too high. It is preferably 10% or less, more preferably 8% or less, particularly preferably 7% or less, and typically 6.5% or less.
ＭｇＯは、耐候性を維持したままαを大きくする、ガラスを傷つきにくくする、またガラスの溶解性を向上させる効果があり必須成分である。２％未満では前記効果が小さい。好ましくは５％以上、より好ましくは７％以上、最も好ましくは８％以上である。１５％超ではＴＬが高くなりすぎる。好ましくは１４％以下、より好ましくは１３％以下である。 MgO is an essential component with the effect of increasing α while maintaining the weather resistance, making the glass less susceptible to damage, and improving the solubility of the glass. If it is less than 2%, the effect is small. Preferably it is 5% or more, more preferably 7% or more, and most preferably 8% or more. If it exceeds 15%, the TL becomes too high. Preferably it is 14% or less, More preferably, it is 13% or less.
ＣａＯは必須ではないが、耐候性を維持したままαを大きくする、またはガラスの溶解性を向上させるために１．５％まで含有してもよい。１．５％超ではガラスが傷つきやすくなるおそれがある。好ましくは１％以下、より好ましくは０．５％未満、典型的には０．３％以下である。 CaO is not essential, but may be contained up to 1.5% in order to increase α while maintaining the weather resistance or to improve the solubility of the glass. If it exceeds 1.5%, the glass may be easily damaged. Preferably it is 1% or less, more preferably less than 0.5%, typically 0.3% or less.
Ｎａ２ＯおよびＫ２Ｏはαを大きくする、またガラスの溶解性を向上させる効果を有する成分であり、少なくともいずれかを含有しなければならない。Ｎａ２ＯおよびＫ２Ｏの含有量の合計Ｎａ２Ｏ＋Ｋ２Ｏが１％未満では前記効果が小さい。好ましくは２％超、より好ましくは５％以上、特に好ましくは７％以上、典型的には１０％以上である。２０％超では耐候性が低下し、ガラス転移点が低下する。好ましくは１７％以下、より好ましくは１５％以下、特に好ましくは１４％以下、典型的には１３．５％以下である。典型的にはＮａ２Ｏが２〜８％、Ｋ２Ｏが３〜１０％である。
ＳｉＯ２が６０％超、Ａｌ２Ｏ３が１０％以下、Ｎａ２Ｏ＋Ｋ２Ｏが２％超１７％以下であることが好ましい。Na2 O and K2 O are components having an effect of increasing α and improving the solubility of glass, and must contain at least one of them. The effect is small when the total Na2 O + K2 O content of Na2 O and K2 O is less than 1%. It is preferably more than 2%, more preferably 5% or more, particularly preferably 7% or more, and typically 10% or more. If it exceeds 20%, the weather resistance is lowered and the glass transition point is lowered. It is preferably 17% or less, more preferably 15% or less, particularly preferably 14% or less, and typically 13.5% or less. Typically, Na2 O is 2 to 8% and K2 O is 3 to 10%.
It is preferable that SiO2 is more than 60%, Al2 O3 is 10% or less, and Na2 O + K2 O is more than 2% and 17% or less.
ＴｉＯ２は必須成分ではないが、Ｔｇを高くする、耐候性を高くする、またはガラスの溶解性を向上させる効果があり、８％まで含有してもよい。８％超ではＴＬが高くなりすぎるおそれがある、または分相現象が起りやすくなるおそれがある。好ましくは７％以下、より好ましくは６％以下、特に好ましくは５％以下である。また、ＴｉＯ２を含有する場合、その含有量は１％以上であることが好ましい。より好ましくは１．５％以上、特に好ましくは２％以上、最も好ましくは３％以上である。
ＭｇＯおよびＴｉＯ２の含有量の合計ＭｇＯ＋ＴｉＯ２は１０％以上であることが好ましい。１０％未満ではガラスが傷つきやすくなるおそれがある、または高温粘性が上昇しガラスの溶解が困難になるおそれがある。ＭｇＯ＋ＴｉＯ２は典型的には１３％以上である。
典型的には、ＳｉＯ２は６２〜７２％、Ａｌ２Ｏ３は２〜８％、ＭｇＯは７〜１４％、Ｎａ２Ｏ＋Ｋ２Ｏは１０〜１４％、ＴｉＯ２は０〜６％である。TiO2 is not an essential component, but has the effect of increasing Tg, increasing weather resistance, or improving glass solubility, and may be contained up to 8%. If it exceeds 8%,TL may be too high, or a phase separation phenomenon may easily occur. Preferably it is 7% or less, More preferably, it is 6% or less, Most preferably, it is 5% or less. Further, when containing TiO2, its content is preferably at least 1%. More preferably, it is 1.5% or more, particularly preferably 2% or more, and most preferably 3% or more.
The total MgO + TiO2 content of MgO and TiO2 is preferably 10% or more. If it is less than 10%, the glass may be easily damaged, or the high-temperature viscosity may increase and it may be difficult to melt the glass. MgO + TiO2 is typically at least 13%.
Typically, SiO2 is 62~72%,Al 2O 3 is 2 to 8%, MgO is7~14%, Na 2 O + K 2 O is 10 to 14%, TiO2 is 6% .
本発明のガラスは本質的に上記成分からなるが、本発明の目的を損なわない範囲でその他の成分を含有してもよい。その場合、当該他の成分の含有量の合計は好ましくは１０％以下、より好ましくは５％以下、典型的には２％以下である。
たとえばＳＯ３、Ｃｌ、Ａｓ２Ｏ３、Ｓｂ２Ｏ３、ＳｎＯ２等の清澄剤を合計で２％まで含有してもよいが、Ａｓ２Ｏ３、Ｓｂ２Ｏ３、ＳｎＯ２は含有しないことが好ましい。
また、ガラスの溶解性や安定性を向上させるためにＢ２Ｏ３を合計で３％まで含有してもよい。
ただし、次のような観点からはＢ２Ｏ３は実質的に含有しないことが好ましい。すなわち、Ｂ２Ｏ３はアルカリ金属酸化物成分と共存すると蒸気圧の低いアルカリボレート化合物を形成しやすくなってガラス融液から同成分が非常に揮散しやすくなる。これにより脈理などの不均質が発生しガラス品質低下を引き起こすと同時に、揮散物がガラス溶融窯に使用されているれんが物質に凝縮し、れんが強度を著しく低下させる、揮散物の回収処理に莫大な費用がかかる、等の問題が発生するため、このような問題の発生を抑制したい場合にはＢ２Ｏ３を実質的に含有しないことが好ましい。The glass of the present invention consists essentially of the above components, but may contain other components as long as the object of the present invention is not impaired. In that case, the total content of the other components is preferably 10% or less, more preferably 5% or less, and typically 2% or less.
For example, clarifiers such as SO3 , Cl, As2 O3 , Sb2 O3 and SnO2 may be contained up to 2% in total, but As2 O3 , Sb2 O3 and SnO2 are not contained. It is preferable.
It may also be contained in order to improve the solubility and stability of the glass up to 3% B2 O3 in total.
However, B2 O3 is from the following viewpoints are preferably substantially free. That is, when B2 O3 coexists with an alkali metal oxide component, it tends to form an alkali borate compound having a low vapor pressure, and the same component is very easily volatilized from the glass melt. This causes inhomogeneities such as striae and causes glass quality deterioration, and at the same time, the volatilized material is condensed into the brick material used in the glass melting kiln, which significantly reduces the strength of the volatilized material. Therefore, it is preferable that B2 O3 is not substantially contained when it is desired to suppress the occurrence of such a problem.
ＳｒＯまたはＢａＯを、耐候性を維持したままαを大きくする、またガラスの溶解性を向上させるために合計で４％以下の範囲で含有してもよい場合がある。４％超ではガラスが傷つきやすくなるおそれがある。好ましくは２％以下である。ただし、ＢａＯを含有する場合その含有量は２モル％以下としなければならない。
なお、ガラスをより傷つきにくくしたい場合などにはＳｒＯは含有しないか、含有する場合でも０．１％未満であることが好ましい。また、このような場合にはＢａＯは含有しないか、含有する場合でも０．１％未満であることが好ましい。
αを大きくする、またはガラスの溶解性を向上させるためにＬｉ２Ｏを１％まで含有してもよい。１％超ではＴｇが低くなる、耐候性が低下する、またはガラスが傷つきやすくなる。典型的には０．６％以下であるが、実質的に含有しないことが多くの場合好ましい。
Ｔｇを高くするためにＺｒＯ２を０．５％まで含有してもよい。０．５％超ではガラスが傷つきやすくなる。In some cases, SrO or BaO may be contained within a total range of 4% or less in order to increase α while maintaining the weather resistance and to improve the solubility of the glass. If it exceeds 4%, the glass may be easily damaged. Preferably it is 2% or less. However, when it contains BaO, the content must be 2 mol% or less.
In addition, when it is desired to make the glass more difficult to be damaged, SrO is not contained, or even if it is contained, it is preferably less than 0.1%. In such a case, BaO is not contained, or even if contained, it is preferably less than 0.1%.
Li2 O may be contained up to 1% in order to increase α or improve the solubility of glass. If it exceeds 1%, the Tg is lowered, the weather resistance is lowered, or the glass is easily damaged. Typically, it is 0.6% or less, but it is often preferable not to contain it substantially.
In order to increase Tg, ZrO2 may be contained up to 0.5%. If it exceeds 0.5%, the glass tends to be damaged.
ＣａＯ、ＳｒＯまたはＢａＯを含有する場合、ＭｇＯ含有量と（ＭｇＯ、ＣａＯ、ＳｒＯおよびＢａＯの各含有量合計）とのモル比：（ＭｇＯ）／（ＭｇＯ＋ＣａＯ＋ＳｒＯ＋ＢａＯ）は０．６以上であることが好ましい。０．６未満ではガラスが傷つきやすくなる。 When CaO, SrO or BaO is contained, the molar ratio of MgO content to (total content of MgO, CaO, SrO and BaO): (MgO) / (MgO + CaO + SrO + BaO) is preferably 0.6 or more. . If it is less than 0.6, the glass tends to be damaged.
Ｌｉ２Ｏ、Ｎａ２ＯおよびＫ２Ｏの各含有量の合計をＲ’２Ｏとし、アルカリ土類金属酸化物の含有量の合計をＲＯとして、Ｒ’２Ｏと（Ｒ’２Ｏ＋ＲＯ）とのモル比、すなわち、（Ｒ’２Ｏ）／（Ｒ’２Ｏ＋ＲＯ）は０．２５〜０．７５であることが好ましい。この範囲外では、耐候性が低下する、αが小さくなる、またはガラスが傷つきやすくなるおそれがある。より好ましくは０．３〜０．７である。
Ｋ２Ｏを含有する場合、Ｋ２Ｏ含有量とＬｉ２Ｏ、Ｎａ２ＯおよびＫ２Ｏの各含有量の合計とのモル比、すなわち、Ｋ２Ｏ／（Ｌｉ２Ｏ＋Ｎａ２Ｏ＋Ｋ２Ｏ）は０．２以上であることが好ましい。０．２未満ではＴｇが低くなる、または耐候性が低下するおそれがある。より好ましくは０．３以上、特に好ましくは０．４以上である。
Ｔｉよりも原子番号が大きな原子（Ｖなど）の酸化物はガラスを傷つきやすくするおそれがあるので、これらを含有する場合にはそれらの含有量の合計は０．５％以下であることが好ましい。より好ましくは０．３％以下、特に好ましくは０．２％以下、最も好ましくは０．１％以下である。The total content of Li2 O, Na2 O and K2 O is R ′2 O, the total content of alkaline earth metal oxides is RO, and R ′2 O and (R ′2 O + RO) the molar ratio of,i.e., (R '2 O) / (R' 2 O + RO) is preferably 0.25 to 0.75. Outside this range, the weather resistance may be reduced, α may be small, or the glass may be easily damaged. More preferably, it is 0.3-0.7.
When containingK2 O, K2 O content andLi 2 O, molar ratio of the sum of the content of Na2 O andK 2 O,i.e., K 2 O / (Li 2 O + Na 2 O + K 2 O ) Is preferably 0.2 or more. If it is less than 0.2, Tg may be lowered, or the weather resistance may be lowered. More preferably, it is 0.3 or more, and particularly preferably 0.4 or more.
Since oxides of atoms having atomic numbers larger than Ti (such as V) may easily damage the glass, when these are contained, the total content thereof is preferably 0.5% or less. . More preferably, it is 0.3% or less, particularly preferably 0.2% or less, and most preferably 0.1% or less.
各成分の原料を「表」中のＳｉＯ２からＺｒＯ２までの欄にモル％表示で示した組成となるように調合し、白金るつぼを用いて１５５０〜１６００℃の温度で３〜５時間溶解した。溶解にあたっては、白金スターラを溶融ガラス中に挿入し、２時間撹拌してガラスを均質化した。次いで溶融ガラスを流し出して板状に成形し、徐冷した。なお、「表」中のＲＯは、ＭｇＯ、ＣａＯ、ＳｒＯおよびＢａＯの含有量（単位：モル％）の合計、Ｒ’２Ｏは、Ｌｉ２Ｏ、Ｎａ２ＯおよびＫ２Ｏの含有量（単位：モル％）の合計を示している。
例１〜１１のガラスは実施例であり、例１２〜２５のガラスは比較例である。The raw materials of each component were prepared so as to have a composition expressed in mol% in the columns from SiO2 to ZrO2 in the “Table”, and dissolved at a temperature of 1550 to 1600 ° C. for 3 to 5 hours using a platinum crucible. did. In melting, a platinum stirrer was inserted into the molten glass and stirred for 2 hours to homogenize the glass. Next, the molten glass was poured out, formed into a plate shape, and gradually cooled. In Tables, RO is the total content of MgO, CaO, SrO and BaO (unit: mol%), and R ′2 O is the content of Li2 O, Na2 O and K2 O ( (Unit: mol%).
The glass of Examples 1-11 is an Example, The glass of Examples 12-25 is a comparative example.
こうして得られたガラス板について、クラック発生率（単位：％）、ガラス転移点Ｔｇ（単位：℃）、熱膨張係数α（単位：×１０−７／℃）、液相温度ＴＬ（単位：℃）、粘度が１０４Ｐとなる温度Ｔ４（単位：℃）、粘度が１０２Ｐとなる温度Ｔ２（単位：℃）、前記ＮＬ（単位：個／ｃｍ２）、前記ＮＳ（単位：１０５個／ｃｍ２）、および密度（単位：ｇ／ｃｍ３）を測定した。結果を「表」中に、Ｔｇ、α、ＴＬ、Ｔ４、Ｔ２、ＮＬ、ＮＳの測定方法を以下にそれぞれ示す。なお、「表」中の「−」で示す項目は測定しなかった。
Ｔｇ：示差熱膨張計を用いて、石英ガラスを参照試料として室温から５℃／分の割合で昇温した際のガラスの伸び率を、ガラスが軟化してもはや伸びが観測されなくなる温度、すなわち屈伏点まで測定し、得られた熱膨張曲線における屈曲点に相当する温度をガラス転移点とした。About the glass plate obtained in this way, crack generation rate (unit:%), glass transition point Tg (unit: ° C.), thermal expansion coefficient α (unit: × 10−7 / ° C.), liquidus temperature TL (unit: ° C.), the temperatureT 4 at which the viscosity becomes 104 P (unit: ° C.), the temperatureT 2 (unit viscosity becomes 102 P: ℃), whereinN L (unit: pieces /cm 2), saidN S (Unit: 105 pieces / cm2 ) and density (unit: g / cm3 ) were measured. The results in "table" indicatesTg, α, T L, T 4, T 2, N L, theN S measurement methods below, respectively. In addition, the item shown by "-" in a "table" was not measured.
Tg: Using a differential thermal dilatometer, the elongation rate of the glass when the temperature is raised from room temperature at a rate of 5 ° C./minute using quartz glass as a reference sample is the temperature at which the glass softens and no longer can be observed. Measurement was made up to the yield point, and the temperature corresponding to the inflection point in the obtained thermal expansion curve was taken as the glass transition point.
α：示差熱膨張計を用いて、石英ガラスを参照試料として室温から５℃／分の割合で昇温した際のガラスの伸び率を、屈伏点まで測定し、得られた熱膨張曲線から５０〜３５０℃における平均線膨張係数を算出した。 α: Using a differential thermal dilatometer, the elongation of the glass was measured from quartz glass as a reference sample at a rate of 5 ° C./min from room temperature to the yield point. The average linear expansion coefficient at ˜350 ° C. was calculated.
ＴＬ：ガラスを乳鉢で２ｍｍ程度のガラス粒に粉砕し、このガラス粒を白金ボートに並べて置き、温度傾斜炉中で２４時間熱処理した。結晶が析出しているガラス粒の温度の最高値を液相温度とした。
Ｔ４、Ｔ２：回転粘度計により測定した。TL : The glass was crushed into glass particles of about 2 mm with a mortar, and these glass particles were placed side by side on a platinum boat and heat-treated in a temperature gradient furnace for 24 hours. The maximum value of the temperature of the glass grains on which the crystals were precipitated was taken as the liquidus temperature.
T4 , T2 : Measured with a rotational viscometer.
ＮＬ、ＮＳ：厚さが１〜２ｍｍ、大きさが４ｃｍ×４ｃｍのガラス板の両面を鏡面研磨し、炭酸カルシウムおよび中性洗剤を用いて洗浄した後、超加速寿命試験器（不飽和型プレッシャークッカーＴＰＣ−４１０、タバイエスペック（株））に入れて１２０℃、２気圧の水蒸気雰囲気に２０時間静置した。取り出したガラス板の表面２００μｍ角の範囲を微分干渉顕微鏡で観察し、大きさが１０μｍ以上の付着物の個数と大きさが１μｍ以上１０μｍ未満の付着物の個数をカウントした。NL , NS : Both sides of a glass plate having a thickness of 1 to 2 mm and a size of 4 cm × 4 cm are mirror-polished, washed with calcium carbonate and a neutral detergent, and then a super accelerated life tester (unsaturated) Was placed in a mold pressure cooker TPC-410, Tabai Espec Co., Ltd.) and allowed to stand in a steam atmosphere at 120 ° C. and 2 atmospheres for 20 hours. The surface of the surface of the glass plate taken out was observed with a differential interference microscope, and the number of deposits having a size of 10 μm or more and the number of deposits having a size of 1 μm or more and less than 10 μm were counted.
磁気ディスク基板等の情報記録媒体基板、磁気ディスク等の情報記録媒体の製造に利用できる。
なお、２００６年１１月２２日に出願された日本特許出願２００６−３１５１２２号の明細書、特許請求の範囲、図面及び要約書の全内容をここに引用し、本発明の明細書の開示として、取り入れるものである。It can be used for manufacturing information recording medium substrates such as magnetic disk substrates and information recording media such as magnetic disks.
It should be noted that the entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2006-315122 filed on November 22, 2006 are cited herein as disclosure of the specification of the present invention. Incorporated.
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| JP5206261B2 (en) | 2007-10-26 | 2013-06-12 | 旭硝子株式会社 | Glass for information recording medium substrate, glass substrate for magnetic disk and magnetic disk |
| CN102584009A (en) | 2008-01-28 | 2012-07-18 | 旭硝子株式会社 | Glass for data storage medium substrate, glass substrate for data storage medium and magnetic disk |
| EP2535320A3 (en) | 2008-02-26 | 2014-05-14 | Corning Incorporated | Fining agents for silicate glasses |
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| JP5699434B2 (en)* | 2009-04-02 | 2015-04-08 | 旭硝子株式会社 | Glass for information recording medium substrate, glass substrate for information recording medium and magnetic disk |
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| KR101790483B1 (en) | 2010-09-27 | 2017-10-25 | 아사히 가라스 가부시키가이샤 | Glass for chemical strengthening, chemically strengthened glass, and glass plate for display device |
| AR083739A1 (en)* | 2010-10-27 | 2013-03-20 | Asahi Glass Co Ltd | GLASS PLATE AND PROCESS FOR PRODUCTION |
| US8394516B2 (en)* | 2010-10-29 | 2013-03-12 | Hoya Corporation | Glass substrate for magnetic recording medium and magnetic recording medium |
| JPWO2013047246A1 (en)* | 2011-09-30 | 2015-03-26 | 旭硝子株式会社 | CdTe solar cell glass substrate and solar cell using the same |
| KR101999090B1 (en) | 2011-10-25 | 2019-07-10 | 코닝 인코포레이티드 | A Glass For Pharmaceutical Packaging |
| CN109704566B (en) | 2011-10-25 | 2022-08-26 | 康宁股份有限公司 | Alkaline earth aluminosilicate glass compositions having improved chemical and mechanical durability |
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| CN105073668B (en)* | 2013-03-22 | 2017-07-25 | 日本板硝子株式会社 | Glass composition, glass composition for chemical strengthening, tempered glass article, and cover glass for display |
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| JPH1072238A (en)* | 1996-04-26 | 1998-03-17 | Carl Zeiss:Fa | Chemically temperable aluminosilicate glass and its use |
| JPH11191212A (en)* | 1997-12-25 | 1999-07-13 | Toshitomo Morisane | High strength smooth glass substrate |
| JP2001294441A (en)* | 2000-04-11 | 2001-10-23 | Asahi Glass Co Ltd | Glass for substrates |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001348246A (en)* | 2000-06-01 | 2001-12-18 | Asahi Glass Co Ltd | Glass for substrates and glass substrates |
| JP4572453B2 (en)* | 2000-07-19 | 2010-11-04 | 旭硝子株式会社 | Information recording medium substrate glass and information recording medium glass substrate |
- 2007
- 2007-11-21JPJP2008545441Apatent/JP5396859B2/ennot_activeExpired - Fee Related
- 2007-11-21WOPCT/JP2007/072590patent/WO2008062847A1/enactiveApplication Filing
- 2007-11-21CNCNA2007800434511Apatent/CN101541696A/enactivePending
- 2007-11-21MYMYPI20092011Apatent/MY157935A/enunknown
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH1072238A (en)* | 1996-04-26 | 1998-03-17 | Carl Zeiss:Fa | Chemically temperable aluminosilicate glass and its use |
| JPH11191212A (en)* | 1997-12-25 | 1999-07-13 | Toshitomo Morisane | High strength smooth glass substrate |
| JP2001294441A (en)* | 2000-04-11 | 2001-10-23 | Asahi Glass Co Ltd | Glass for substrates |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101541696A (en) | 2009-09-23 |
| WO2008062847A1 (en) | 2008-05-29 |
| JPWO2008062847A1 (en) | 2010-03-04 |
| MY157935A (en) | 2016-08-15 |
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