JP5294150B2 - Method for producing tempered glass - Google Patents
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本発明は、強化ガラスの製造方法に関し、具体的には、ディスプレイ用基板、タッチパネルディスプレイのカバーガラス、携帯電話のカバーガラス、太陽電池のカバーガラスおよび基板、外装部品等の高強度が要求されるデバイス・ツール等に好適な強化ガラスの製造方法に関する。 The present invention relates to a method for producing tempered glass, and specifically, high strength is required for a display substrate, a cover glass for a touch panel display, a cover glass for a mobile phone, a cover glass and substrate for a solar cell, an exterior component, and the like. The present invention relates to a method for producing tempered glass suitable for a device / tool.
タッチパネルを搭載した携帯電話が普及しており、携帯電話のカバーガラスには、イオン交換等で強化処理したガラス（所謂、強化ガラス）が用いられつつある。強化ガラスは、未強化のガラスに比べて、機械的強度が高いため、本用途に好適である（特許文献１、非特許文献１参照）。 Mobile phones equipped with a touch panel are widely used, and glass (so-called tempered glass) tempered by ion exchange or the like is being used as a cover glass for mobile phones. Since tempered glass has higher mechanical strength than unstrengthened glass, it is suitable for this application (see Patent Document 1 and Non-Patent Document 1).
近年、携帯電話以外の用途でもタッチパネルが搭載されつつあり、用途によっては、特定形状、例えば曲面形状を有する外装部品が必要になる。これらの用途に強化ガラスを適用するためには、強化ガラスを特定形状、例えば曲面形状に加工する必要がある。特定形状の強化ガラスは、まず溶融ガラスを成形して平板形状のガラス等を作製し、次いで熱加工で特定形状に変形させた後、強化処理を行うことで作製することができる（特許文献２、３参照）。 In recent years, touch panels are being installed in applications other than mobile phones, and depending on the application, exterior parts having a specific shape, for example, a curved shape, are required. In order to apply tempered glass to these uses, it is necessary to process the tempered glass into a specific shape, for example, a curved shape. The tempered glass having a specific shape can be prepared by first forming molten glass to produce a flat plate-shaped glass, etc., and then deforming the glass into a specific shape by thermal processing, followed by a tempering treatment (Patent Document 2). 3).
したがって、これらの強化ガラスは、機械的強度が高いことに加えて、熱加工性に優れることが求められる。 Accordingly, these tempered glasses are required to have excellent thermal workability in addition to high mechanical strength.
表面に形成される圧縮応力層の圧縮応力値を高くし、且つ圧縮応力層の厚み（深さ）を大きくすれば、強化ガラスの機械的強度を高めることができる。 If the compressive stress value of the compressive stress layer formed on the surface is increased and the thickness (depth) of the compressive stress layer is increased, the mechanical strength of the tempered glass can be increased.
しかし、圧縮応力層の圧縮応力値を高めつつ、圧縮応力層の厚みを大きくすることは困難である。圧縮応力層の厚みを大きくするためには、イオン交換温度を高くする、或いはイオン交換時間を長くする必要があるが、このような処理を行うと、圧縮応力層の圧縮応力値が大幅に低下するからである。 However, it is difficult to increase the thickness of the compressive stress layer while increasing the compressive stress value of the compressive stress layer. In order to increase the thickness of the compressive stress layer, it is necessary to increase the ion exchange temperature or lengthen the ion exchange time. However, when such treatment is performed, the compressive stress value of the compressive stress layer is significantly reduced. Because it does.
従来、この問題を解決するために、ガラス組成中にＡｌ２Ｏ３等のイオン交換性能を向上させる成分を導入することが検討されてきた。しかし、これらの成分を多量に導入すると、ガラスの粘性が高くなり、ガラスを熱加工することが困難になる。 Conventionally, in order to solve this problem, it has been studied to introduce a component that improves ion exchange performance such as Al 2 O 3 into the glass composition. However, when these components are introduced in a large amount, the viscosity of the glass increases and it becomes difficult to heat-process the glass.
ところで、ハードディスクの一部には、強化ガラスが用いられており、この強化ガラスは、例えばガラスをプレス成形した後に強化処理することで作製されている。しかし、ハードディスクは、一旦、デバイスに組み込まれると、取り扱い傷が発生しないため、圧縮応力層の厚みを大きくする必要性がない。それどころか、ハードディスクは、表面の平滑性を重視するが故に、強化処理後に、表面を研磨して圧縮応力層を除去する場合もある。したがって、ハードディスクに用いられる強化ガラスは、そのまま外装部品に転用することが困難である。 By the way, tempered glass is used for a part of the hard disk, and this tempered glass is produced by, for example, press-molding glass and then tempering it. However, once a hard disk is incorporated into a device, handling scratches do not occur, so there is no need to increase the thickness of the compressive stress layer. On the contrary, since the hard disk emphasizes the smoothness of the surface, the surface of the hard disk may be polished to remove the compressive stress layer after the strengthening treatment. Therefore, it is difficult to divert tempered glass used for a hard disk as it is to exterior parts.
そこで、本発明は、高い機械的強度が得られるように、圧縮応力層の圧縮応力値と厚みを適正化することができ、しかも熱加工を容易に行うことができる強化ガラスの製造方法を創案することを技術的課題とする。 Therefore, the present invention has devised a method for producing a tempered glass that can optimize the compressive stress value and thickness of the compressive stress layer so that high mechanical strength can be obtained, and that can be easily heat-processed. Doing this is a technical issue.
本発明者は、種々の検討を行った結果、ガラスを構成する原子の網目構造の隙間が強化特性に影響を与えること、具体的には同一のガラス組成でも、熱加工後（或いは成形直後）に、特定温度範囲において特定の冷却処理を行えば、強化処理後に形成される圧縮応力層の圧縮応力値と厚みを適正化できることを見出した。すなわち、本発明の強化ガラスの製造方法は、オーバーフローダウンドロー法で溶融ガラスを平板形状のガラスに成形した上で、成形後のガラスを熱加工した後に冷却し、得られたガラスに対して強化処理を行う強化ガラスの製造方法であって、該冷却は、徐冷点から歪点までの温度域を２００℃／分以下の冷却速度で冷却する工程を含むことを特徴とする。「徐冷点」は、ＡＳＴＭ Ｃ３３６の方法に基づいて測定した値を指し、「歪点」もＡＳＴＭ Ｃ３３６の方法に基づいて測定した値を指す。 As a result of various studies, the present inventor has found that the gap in the network structure of atoms constituting the glass affects the strengthening properties. Specifically, even with the same glass composition, after thermal processing (or immediately after molding). Furthermore, it has been found that if a specific cooling process is performed in a specific temperature range, the compressive stress value and thickness of the compressive stress layer formed after the strengthening process can be optimized. That is, the manufacturing method of the tempered glass of the present invention is a method in which the molten glass is formed into a flat plate glass by the overflow downdraw method, and then the formed glass is cooled after being heat-processed and tempered with respect to the obtained glass. A method for producing a tempered glass, wherein the cooling includes a step of cooling a temperature range from an annealing point to a strain point at a cooling rate of 200 ° C./min or less . “ Annealing point” refers to a value measured based on the method of ASTM C336, and “strain point” also refers to a value measured based on the method of ASTM C336.
このようにすれば、ガラスの粘性を不当に上昇させずに、圧縮応力層の圧縮応力値と厚みを適正化、具体的には圧縮応力層の厚みを確保した上で、圧縮応力層の圧縮応力値を高めることができ、結果として、強化ガラスの機械的強度を高めることができるとともに、熱加工により特定形状、特に平板形状以外の形状の強化ガラスを容易に作製することができる。なお、強化処理を行った後に、徐冷点付近まで熱処理すると、ほとんどの圧縮応力層が消失し、強化ガラスの機械的強度が低下する。 In this way, the compression stress value and thickness of the compression stress layer are optimized without specifically increasing the viscosity of the glass. Specifically, the compression stress layer is compressed after securing the thickness of the compression stress layer. The stress value can be increased. As a result, the mechanical strength of the tempered glass can be increased, and a tempered glass having a specific shape, particularly a shape other than a flat plate shape, can be easily produced by thermal processing. In addition, when it heat-processes to the annealing point vicinity after performing a tempering process, most compressive-stress layers will lose | disappear and the mechanical strength of tempered glass will fall.
本発明の強化ガラスの製造方法は、徐冷点から歪点までの温度域を５０℃／分以下の冷却速度で冷却することが好ましい。 In the method for producing tempered glass of the present invention, it is preferable to cool the temperature range from the annealing point to the strain point at a cooling rate of 50 ° C./min or less.
本発明の強化ガラスの製造方法は、ガラスを熱加工した後に冷却することを特徴とする。このようにすれば、圧縮応力層の圧縮応力値を高めつつ、強化ガラスのデザイン性を高めることができる。 The method for producing tempered glass of the present invention is characterized in that the glass is cooled after being thermally processed. If it does in this way, the design property of tempered glass can be raised, raising the compression stress value of a compression stress layer.
本発明の強化ガラスの製造方法は、強化処理がガラスの表面に圧縮応力層を形成する化学強化処理であり、且つ圧縮応力層の圧縮応力値が５０ＭＰａ以上、圧縮応力層の厚みが１０μｍ以上になるように化学強化処理を行うことが好ましい。 The method for producing tempered glass of the present invention is a chemical tempering treatment in which the tempering treatment forms a compressive stress layer on the surface of the glass, the compressive stress value of the compressive stress layer is 50 MPa or more, and the thickness of the compressive stress layer is 10 μm or more. It is preferable to perform the chemical strengthening treatment.
本発明の強化ガラスの製造方法は、ガラス組成として、質量％で、ＳｉＯ２ ４５〜７５％、Ａｌ２Ｏ３ ０〜３０％、Ｌｉ２Ｏ＋Ｎａ２Ｏ＋Ｋ２Ｏ（Ｌｉ２Ｏ、Ｎａ２Ｏ、Ｋ２Ｏの合量） ０〜３０％含有するように、ガラス原料（カレットを含む）を調合した後、ガラス原料を溶融し、得られた溶融ガラスをガラスに成形することが好ましい。 Method for producing a tempered glass of the present invention has a glass composition, in mass%, SiO 2 45~75%, Al 2 O 3 0~30%, Li 2 O + Na 2 O + K 2 O (Li 2 O, Na 2 O, (Total amount of K 2 O) After preparing glass raw materials (including cullet) so as to contain 0 to 30%, it is preferable to melt the glass raw materials and shape the resulting molten glass into glass.
本発明の強化ガラスの製造方法は、ガラス組成として、質量％で、ＳｉＯ２ ４５〜７５％、Ａｌ２Ｏ３ １０〜２２％、Ｂ２Ｏ３ ０〜５％、Ｎａ２Ｏ ８〜２０％、Ｋ２Ｏ ０〜１０％含有するように、ガラス原料を調合することが好ましい。 The method of producing glass of the present invention has a glass composition, in mass%, SiO 2 45~75%, Al 2 O 3 10~22%, B 2 O 3 0~5%, Na 2 O 8~20% It is preferable to prepare the glass raw material so as to contain 0 to 10% of K 2 O.
本発明の強化ガラスの製造方法は、オーバーフローダウンドロー法で溶融ガラスを平板形状のガラスに成形することを特徴とする。このようにすれば、未研磨で表面精度が良好な平板形状のガラスを容易に作製することができ、またガラスを熱加工しやすくなる。 The method for producing tempered glass of the present invention is characterized in that molten glass is formed into flat glass by an overflow downdraw method. In this way, it is possible to easily produce a glass plate that is unpolished and has good surface accuracy, and it is easy to thermally process the glass.
本発明の強化ガラスの製造方法は、軟化点が８６０℃以下になるようにガラス原料を調合することが好ましい。このようにすれば、ガラスを熱加工しやすくなる。ここで、「軟化点」はＡＳＴＭ Ｃ３３８の方法に基づいて測定した値を指す。 In the method for producing tempered glass of the present invention, the glass raw material is preferably prepared so that the softening point is 860 ° C. or lower. If it does in this way, it will become easy to heat-process glass. Here, the “softening point” refers to a value measured based on the method of ASTM C338.
本発明の強化ガラスの製造方法は、熱膨張係数が６０〜１１０×１０−７／℃になるようにガラス原料を調合することが好ましい。ここで、「熱膨張係数」は、ディラトメーターで測定した値であり、３０〜３８０℃の温度範囲における平均値を指す。 In the method for producing tempered glass of the present invention, the glass raw material is preferably prepared so that the thermal expansion coefficient is 60 to 110 × 10 −7 / ° C. Here, the “thermal expansion coefficient” is a value measured with a dilatometer, and indicates an average value in a temperature range of 30 to 380 ° C.
本発明の強化ガラスの製造方法は、液相温度が１２００℃以下になるようにガラス原料を調合することが好ましい。ここで、「液相温度」は、ガラスを粉砕し、標準篩３０メッシュ（篩目開き５００μｍ）を通過し、５０メッシュ（篩目開き３００μｍ）に残るガラス粉末を白金ボートに入れ、温度勾配炉中に２４時間保持して、結晶の析出する温度を指す。 In the method for producing tempered glass of the present invention, the glass raw material is preferably prepared so that the liquidus temperature is 1200 ° C. or lower. Here, “liquid phase temperature” refers to a temperature gradient furnace in which glass is crushed, passed through a standard sieve 30 mesh (a sieve opening of 500 μm), and glass powder remaining in a 50 mesh (a sieve opening of 300 μm) is placed in a platinum boat. It is held for 24 hours to indicate the temperature at which crystals precipitate.
本発明の強化ガラスの製造方法は、液相粘度が１０４．０ｄＰａ・ｓ以上になるようにガラス原料を調合することが好ましい。ここで、「液相粘度」は、液相温度におけるガラスの粘度を白金球引き上げ法で測定した値を指す。 In the method for producing tempered glass of the present invention, it is preferable to prepare the glass raw material so that the liquid phase viscosity is 10 4.0 dPa · s or more. Here, “liquid phase viscosity” refers to a value obtained by measuring the viscosity of glass at the liquid phase temperature by a platinum ball pulling method.
本発明の強化ガラスは、上記の製造方法により作製されてなることが好ましい。 It is preferable that the tempered glass of this invention is produced by said manufacturing method.
本発明の強化ガラスは、平板形状以外の形状、例えば曲面形状、凹凸形状、波型形状、段付形状等を有することが好ましい。 Glass of the present invention, the shape other than the plate shape, for example curved, uneven, wavy shape, preferably has a stepped shape.
本発明の強化ガラスは、ディスプレイ用基板に用いることが好ましい。 The tempered glass of the present invention is preferably used for a display substrate.
本発明の強化ガラスは、タッチパネルディスプレイのカバーガラスに用いることが好ましい。 The tempered glass of the present invention is preferably used for a cover glass of a touch panel display.
本発明の強化ガラスは、携帯電話のカバーガラスに用いることが好ましい。 The tempered glass of the present invention is preferably used for a cover glass of a mobile phone.
本発明の強化ガラスは、太陽電池の基板またはカバーガラスに用いることが好ましい。 The tempered glass of the present invention is preferably used for a solar cell substrate or cover glass.
本発明の強化ガラスは、外装部材に用いることが好ましい。 The tempered glass of the present invention is preferably used for an exterior member.
本発明の強化ガラスの製造方法は、徐冷点から歪点までの温度域を２００℃／分以下の冷却速度で冷却する工程を有し、１００℃／分以下、５０℃／分以下、１０℃／分以下、５℃／分以下、３℃／分以下、２℃／分以下、１℃／分以下、０．５℃／分以下、特に０．２℃／分以下の冷却速度で冷却する工程を有することが好ましい。冷却速度が２００℃／分より速いと、ガラスの構造が疎になり過ぎて、イオン交換処理を行っても高い圧縮応力値を得難くなる。一方、冷却速度が０．２℃／分より遅いと、強化ガラスの生産性が低下する。特に、熱加工によりガラスを特定形状に変形させた後、上記温度域において上記冷却速度で冷却すると、高い圧縮応力値が得られるとともに、強化ガラスのデザイン性を高めることができる。なお、ガラスを特定形状にプレス成形した後、上記温度域において上記冷却速度で冷却した場合も、圧縮応力層の圧縮応力値が高まるとともに、強化ガラスのデザイン性を高めることができる。 The manufacturing method of the tempered glass of this invention has the process of cooling the temperature range from an annealing point to a strain point with the cooling rate of 200 degrees C / min or less, 100 degrees C / min or less, 50 degrees C / min or less, 10 Cooling at a cooling rate of 5 ° C / min or less, 5 ° C / min or less, 3 ° C / min or less, 2 ° C / min or less, 1 ° C / min or less, 0.5 ° C / min or less, particularly 0.2 ° C / min or less It is preferable to have the process to do. When the cooling rate is faster than 200 ° C./min, the glass structure becomes too sparse, and it is difficult to obtain a high compressive stress value even if ion exchange treatment is performed. On the other hand, when the cooling rate is slower than 0.2 ° C./min, the productivity of the tempered glass decreases. In particular, when the glass is deformed into a specific shape by thermal processing and then cooled at the cooling rate in the temperature range, a high compressive stress value can be obtained and the design of the tempered glass can be enhanced. In addition, also when it cools with the said cooling rate in the said temperature range after press-molding glass to a specific shape, while the compressive-stress value of a compressive-stress layer increases, the design property of tempered glass can be improved.
本発明の強化ガラスの製造方法は、強化処理を行う工程、つまりガラスに圧縮応力層を形成する工程を有する。ガラスに圧縮応力層を形成する方法には、物理強化法と化学強化法があるが、本発明の強化ガラスの製造方法は、化学強化法で圧縮応力層を形成することが好ましい。化学強化法は、ガラスの歪点以下の温度で、イオン交換によりガラスの表面にイオン半径の大きいアルカリイオン等を導入する方法である。化学強化法で圧縮応力層を形成すれば、ガラスの厚みが薄くても、イオン交換処理を行うことができ、所望の機械的強度を得ることができる。さらに、化学強化法で圧縮応力層を形成すれば、風冷強化法等の物理強化法とは異なり、強化処理後に強化ガラスを切断した場合でも、強化ガラスが容易に破壊することがない。 The manufacturing method of the tempered glass of this invention has the process of performing a tempering process, ie, the process of forming a compression stress layer in glass. There are a physical tempering method and a chemical tempering method as a method for forming a compressive stress layer on glass, but it is preferable that the method for producing tempered glass of the present invention forms a compressive stress layer by a chemical tempering method. The chemical strengthening method is a method in which alkali ions having a large ion radius are introduced into the surface of the glass by ion exchange at a temperature below the strain point of the glass. If the compressive stress layer is formed by the chemical strengthening method, the ion exchange treatment can be performed even if the glass is thin, and a desired mechanical strength can be obtained. Furthermore, if the compressive stress layer is formed by a chemical tempering method, unlike a physical tempering method such as an air cooling tempering method, even if the tempered glass is cut after the tempering treatment, the tempered glass is not easily broken.
本発明の強化ガラスの製造方法において、イオン交換処理は、例えば４００〜５５０℃の硝酸カリウム溶液中にガラスを１〜８時間浸漬することで行うことができる。イオン交換条件は、ガラスの粘度特性や、用途、板厚、内部の引っ張り応力等を考慮して最適な条件を選択すればよい。 In the method for producing tempered glass of the present invention, the ion exchange treatment can be performed by immersing the glass in a potassium nitrate solution at 400 to 550 ° C. for 1 to 8 hours, for example. What is necessary is just to select optimal conditions for the ion exchange conditions in consideration of the viscosity characteristics of glass, application, plate thickness, internal tensile stress, and the like.
本発明の強化ガラスの製造方法において、圧縮応力層の圧縮応力値が５０ＭＰａ以上、１００ＭＰａ以上、３００ＭＰａ以上、５００ＭＰａ以上、６００ＭＰａ以上、特に７００ＭＰａ以上になるように化学強化処理を行うことが好ましい。圧縮応力値が大きくなるにつれて、強化ガラスの機械的強度が高くなる。一方、表面に極端に大きな圧縮応力が形成されると、表面にマイクロクラックが発生しやすくなり、逆に強化ガラスの機械的強度が低下する虞がある。また、表面に極端に大きな圧縮応力が形成されると、内部の引っ張り応力が極端に高くなる虞があるため、圧縮応力層の圧縮応力が１３００ＭＰａ以下となるように化学強化処理を行うことが好ましい。なお、ガラス組成中のＡｌ２Ｏ３、ＴｉＯ２、ＺｒＯ２、ＭｇＯ、ＺｎＯの含有量を増加、ＳｒＯ、ＢａＯの含有量を低減すると、圧縮応力層の圧縮応力値を高めることができる。また、イオン交換時間を短くしたり、イオン交換温度を下げると、圧縮応力層の圧縮応力値を高めることができる。 In the method for producing tempered glass of the present invention, it is preferable to perform chemical strengthening treatment so that the compressive stress value of the compressive stress layer is 50 MPa or more, 100 MPa or more, 300 MPa or more, 500 MPa or more, 600 MPa or more, and particularly 700 MPa or more. As the compressive stress value increases, the mechanical strength of the tempered glass increases. On the other hand, when an extremely large compressive stress is formed on the surface, microcracks are likely to occur on the surface, and conversely, the mechanical strength of the tempered glass may be reduced. In addition, if an extremely large compressive stress is formed on the surface, the internal tensile stress may become extremely high. Therefore, it is preferable to perform chemical strengthening so that the compressive stress of the compressive stress layer is 1300 MPa or less. . In addition, if the content of Al 2 O 3 , TiO 2 , ZrO 2 , MgO, ZnO in the glass composition is increased and the content of SrO, BaO is decreased, the compressive stress value of the compressive stress layer can be increased. Moreover, when the ion exchange time is shortened or the ion exchange temperature is lowered, the compressive stress value of the compressive stress layer can be increased.
本発明の強化ガラスの製造方法において、圧縮応力層の厚みが１０μｍ以上、２０μｍ以上、３０μｍ以上、４０μｍ以上、５０μｍ以上、特に６０μｍ以上になるように化学強化処理を行うことが好ましい。強化ガラスを外装部品に用いる場合、強化ガラスの表面が直接接触される機会が多くなり、取り扱い傷により、強化ガラスの機械的強度が著しく低下することがある。そこで、圧縮応力層の厚みを大きくすれば、強化ガラスに深い傷がついても、強化ガラスが割れ難くなる。一方、切断加工しやすくするために、圧縮応力層の厚みを２００μｍ以下とするのが好ましい。なお、ガラス組成中のＡｌ２Ｏ３、ＴｉＯ２、ＺｒＯ２、ＭｇＯ、ＺｎＯの含有量を増加、ＳｒＯ、ＢａＯの含有量を低減すると、圧縮応力層の厚みを大きくすることができる。さらに、イオン交換時間を長くしたり、イオン交換温度を上げると、圧縮応力層の厚みを大きくすることができる。 In the method for producing tempered glass of the present invention, it is preferable to perform the chemical strengthening treatment so that the thickness of the compressive stress layer is 10 μm or more, 20 μm or more, 30 μm or more, 40 μm or more, 50 μm or more, particularly 60 μm or more. When tempered glass is used for exterior parts, the surface of the tempered glass is often contacted directly, and the mechanical strength of the tempered glass may be significantly reduced due to handling flaws. Therefore, if the thickness of the compressive stress layer is increased, the tempered glass is hardly broken even if the tempered glass is deeply damaged. On the other hand, the thickness of the compressive stress layer is preferably 200 μm or less in order to facilitate cutting. In addition, if the content of Al 2 O 3 , TiO 2 , ZrO 2 , MgO, ZnO in the glass composition is increased and the content of SrO, BaO is decreased, the thickness of the compressive stress layer can be increased. Furthermore, when the ion exchange time is lengthened or the ion exchange temperature is raised, the thickness of the compressive stress layer can be increased.
本発明の強化ガラスの製造方法において、以下の数式１で計算される内部の引っ張り応力値が２００ＭＰａ以下、１５０ＭＰａ以下、１００ＭＰａ以下、特に５０ＭＰａ以下になるように化学強化処理を行うことが好ましい。内部の引っ張り応力値が小さい程、内部の欠陥によって、強化ガラスが破損する確率が低くなる。ただし、内部の引っ張り応力値を極端に小さくし過ぎると、圧縮応力層の圧縮応力値が低下しやすくなり、また圧縮応力層の厚みが小さくなりやすいため、内部の引っ張り応力値は１ＭＰａ以上、１０ＭＰａ以上、特に１５ＭＰａ以上が好ましい。 In the method for producing tempered glass of the present invention, it is preferable to perform chemical strengthening treatment so that the internal tensile stress value calculated by the following formula 1 is 200 MPa or less, 150 MPa or less, 100 MPa or less, and particularly 50 MPa or less. The smaller the internal tensile stress value, the lower the probability that the tempered glass will break due to internal defects. However, if the internal tensile stress value is made extremely small, the compressive stress value of the compressive stress layer tends to decrease and the thickness of the compressive stress layer tends to be small, so the internal tensile stress value is 1 MPa or more and 10 MPa. Above, especially 15 MPa or more is preferable.
本発明の強化ガラスの製造方法において、ガラス組成として、質量％で、ＳｉＯ２ ４５〜７５％、Ａｌ２Ｏ３ ０〜３０％、Ｌｉ２Ｏ＋Ｎａ２Ｏ＋Ｋ２Ｏ ０〜３０％含有するように、ガラス原料を調合することが好ましい。本発明の強化ガラスの製造方法において、上記のようにガラス組成範囲を規制した理由を下記に示す。 The method of manufacturing a tempered glass of the present invention, as a glass composition, in mass%, SiO 2 45~75%, Al 2 O 3 0~30%, Li 2 O + Na 2 O + K 2 O so as to contain 0-30%, It is preferable to prepare a glass raw material. The reason why the glass composition range is regulated as described above in the method for producing tempered glass of the present invention will be described below.
ＳｉＯ２は、ガラスのネットワークを形成する成分であり、その含有量は４５〜７５％、好ましくは５０〜７０％、より好ましくは５０〜６６％、更に好ましくは５２〜６３％、特に好ましくは５４〜６３％である。ＳｉＯ２の含有量が多過ぎると、溶融性や成形性が低下することに加えて、熱膨張係数が低くなり過ぎて、周辺材料の熱膨張係数に整合させ難くなる。一方、ＳｉＯ２の含有量が少な過ぎると、ガラス化し難くなることに加えて、熱膨張係数が高くなり過ぎて、耐熱衝撃性が低下しやすくなる。 SiO 2 is a component that forms a glass network, and the content thereof is 45 to 75%, preferably 50 to 70%, more preferably 50 to 66%, still more preferably 52 to 63%, and particularly preferably 54. ~ 63%. If the content of SiO 2 is too large, the meltability and moldability are lowered, and the thermal expansion coefficient is too low, making it difficult to match the thermal expansion coefficient of the surrounding materials. On the other hand, if the content of SiO 2 is too small, it becomes difficult to vitrify, the thermal expansion coefficient becomes too high, and the thermal shock resistance tends to be lowered.
Ａｌ２Ｏ３は、イオン交換性能を向上させる成分であり、また歪点やヤング率を高める成分であり、その含有量は０〜３０％である。Ａｌ２Ｏ３の含有量が多過ぎると、ガラスに失透結晶が析出しやすくなり、例えばオーバーフローダウンドロー法等でガラスを成形し難くなる。また、Ａｌ２Ｏ３の含有量が多過ぎると、熱膨張係数が低くなり過ぎて、周辺材料の熱膨張係数に整合させ難くなったり、高温粘性が高くなり、ガラスを溶融し難くなったり、軟化点が高くなり過ぎて、熱加工・プレス成形時の温度が高くなり、成形金型の寿命が低下する虞がある。一方、Ａｌ２Ｏ３の含有量が少な過ぎると、イオン交換性能を十分に発揮できない虞がある。上記観点を総合的に判断すると、Ａｌ２Ｏ３の上限範囲は２５％以下、２３％以下、２２％以下、２０％以下、１９％以下、１８％以下、１７％以下、特に１６．５％以下が好ましい。また、Ａｌ２Ｏ３の下限範囲は３％以上、５％以上、１０％以上、１２％以上、１３％以上、特に１４％以上が好ましい。 Al 2 O 3 is a component that improves ion exchange performance, and is a component that increases the strain point and Young's modulus, and its content is 0 to 30%. When Al 2 O 3 content is too large, devitrification crystal glass is easily precipitated, it becomes difficult to mold the glass, for example, an overflow down draw method and the like. Also, if the content of Al 2 O 3 is too large, the thermal expansion coefficient becomes too low, making it difficult to match the thermal expansion coefficient of the surrounding material, increasing the high temperature viscosity, making it difficult to melt the glass, Since the softening point becomes too high, the temperature at the time of heat processing / press molding becomes high, and the life of the molding die may be reduced. On the other hand, when the content of Al 2 O 3 is too small, there is a possibility which can not be sufficiently exhibited ion exchange performance. Judging from the above viewpoint, the upper limit range of Al 2 O 3 is 25% or less, 23% or less, 22% or less, 20% or less, 19% or less, 18% or less, 17% or less, particularly 16.5%. The following is preferred. Further, the lower limit range of Al 2 O 3 is preferably 3% or more, 5% or more, 10% or more, 12% or more, 13% or more, particularly 14% or more.
Ｌｉ２Ｏ＋Ｎａ２Ｏ＋Ｋ２Ｏは、イオン交換成分であり、高温粘度を低下させて、溶融性や成形性を高める成分である。Ｌｉ２Ｏ＋Ｎａ２Ｏ＋Ｋ２Ｏが多過ぎると、ガラスが失透しやすくなることに加えて、熱膨張係数が高くなり過ぎて、耐熱衝撃性が低下したり、周辺材料の熱膨張係数に整合させ難くなる。また、Ｌｉ２Ｏ＋Ｎａ２Ｏ＋Ｋ２Ｏが多過ぎると、歪点が低下し過ぎて、圧縮応力層の圧縮応力値を高め難くなる場合がある。さらに、Ｌｉ２Ｏ＋Ｎａ２Ｏ＋Ｋ２Ｏが多過ぎると、液相温度付近の粘性が低下し、高い液相粘度を確保し難くなる場合がある。よって、Ｌｉ２Ｏ＋Ｎａ２Ｏ＋Ｋ２Ｏの含有量は３０％以下、好ましくは２５％以下、より好ましくは２０％以下である。一方、Ｌｉ２Ｏ＋Ｎａ２Ｏ＋Ｋ２Ｏが少な過ぎると、イオン交換性能や溶融性が低下したり、軟化点が高くなり過ぎる場合がある。よって、Ｌｉ２Ｏ＋Ｎａ２Ｏ＋Ｋ２Ｏの含有量は、０．１％以上、８％以上、１０％以上、１３％以上、特に１５％以上が好ましい。 Li 2 O + Na 2 O + K 2 O is an ion exchange component, and is a component that lowers the high-temperature viscosity and improves the meltability and moldability. If there is too much Li 2 O + Na 2 O + K 2 O, in addition to the glass becoming more devitrified, the thermal expansion coefficient becomes too high, the thermal shock resistance is lowered, or the thermal expansion coefficient of the surrounding material is matched. It becomes difficult. Further, when the Li 2 O + Na 2 O + K 2 O is too large, the strain point excessively lowers, it may become difficult to increase the compression stress value of the compressive stress layer. Further, when the Li 2 O + Na 2 O + K 2 O is too large, there are cases where the viscosity is lowered in the vicinity of the liquidus temperature, it is difficult to ensure a high liquidus viscosity. Therefore, the content of Li 2 O + Na 2 O + K 2 O is 30% or less, preferably 25% or less, more preferably 20% or less. On the other hand, there is a case where the Li 2 O + Na 2 O + K 2 O is too small, or decreased the ion exchange performance and meltability, softening point becomes too high. Therefore, the content of Li 2 O + Na 2 O + K 2 O is preferably 0.1% or more, 8% or more, 10% or more, 13% or more, and particularly preferably 15% or more.
Ｌｉ２Ｏは、イオン交換成分であり、高温粘度を低下させて、溶融性や成形性を高める成分である。また、Ｌｉ２Ｏは、ヤング率を高める成分であるとともに、アルカリ金属酸化物の中では圧縮応力値を高めやすい成分である。しかし、Ｌｉ２Ｏの含有量が多過ぎると、液相粘度が低下して、ガラスが失透しやすくなることに加えて、熱膨張係数が高くなり過ぎて、耐熱衝撃性が低下したり、周辺材料の熱膨張係数に整合させ難くなる。さらに、Ｌｉ２Ｏの含有量が多過ぎると、低温粘性、特に歪点が低下し過ぎて、イオン交換時に応力緩和が起こりやすくなり、逆に圧縮応力層の圧縮応力値が低くなる場合がある。したがって、Ｌｉ２Ｏの含有量は０〜１０％、０〜８％、０〜６％、０〜４％、０〜３％、０〜２％、０〜１％、特に０〜０．１％が好ましい。 Li 2 O is an ion exchange component, and is a component that lowers the high-temperature viscosity and improves the meltability and moldability. Li 2 O is a component that increases the Young's modulus and is a component that easily increases the compressive stress value among alkali metal oxides. However, if the content of Li 2 O is too large, the liquid phase viscosity is lowered and the glass is liable to be devitrified, the thermal expansion coefficient is too high, and the thermal shock resistance is lowered. It becomes difficult to match the thermal expansion coefficient of the surrounding material. Furthermore, if the content of Li 2 O is too large, the low-temperature viscosity, particularly the strain point, is too low, and stress relaxation is likely to occur during ion exchange, and conversely, the compressive stress value of the compressive stress layer may be low. . Therefore, the content of Li 2 O is 0 to 10%, 0 to 8%, 0 to 6%, 0 to 4%, 0 to 3%, 0 to 2%, 0 to 1%, particularly 0 to 0.1. % Is preferred.
Ｎａ２Ｏは、イオン交換成分であり、ガラスの高温粘度を低下させて、溶融性や成形性を高める成分であるとともに、耐失透性を改善する成分であり、その含有量は８〜２０％、８〜１６％、８〜１５％、９〜１５％、１０〜１５％、１１〜１５％、特に１２〜１５％が好ましい。Ｎａ２Ｏの含有量が多過ぎると、熱膨張係数が高くなり過ぎて、耐熱衝撃性が低下したり、周辺材料の熱膨張係数に整合させ難くなる。また、Ｎａ２Ｏの含有量が多過ぎると、歪点が低下し過ぎたり、ガラス組成の成分バランスが損なわれて、逆に耐失透性が低下する傾向がある。一方、Ｎａ２Ｏの含有量が少な過ぎると、溶融性が低下したり、熱膨張係数が低くなり過ぎたり、軟化点が高くなり過ぎたり、イオン交換性能が低下する。 Na 2 O is an ion exchange component, is a component that lowers the high temperature viscosity of glass and improves meltability and moldability, and is a component that improves devitrification resistance, and its content is 8-20. %, 8 to 16%, 8 to 15%, 9 to 15%, 10 to 15%, 11 to 15%, particularly 12 to 15% are preferable. When the content of Na 2 O is too large, the thermal expansion coefficient becomes too high, the thermal shock resistance becomes difficult to match or decreased, the thermal expansion coefficient with those of peripheral materials. Further, when the content of Na 2 O is too large, or too low the strain point, it is impaired balance of components glass composition, devitrification resistance conversely tends to decrease. On the other hand, if too small content of Na 2 O, lowered the melting property, become too coefficient of thermal expansion is low, or too high softening point, decreases the ion exchange performance.
Ｋ２Ｏは、イオン交換性能を向上させる成分であり、アルカリ金属酸化物の中では圧縮応力層の厚みを大きくする効果が高い成分である。また、Ｋ２Ｏは、高温粘度を低下させて、溶融性や成形性を高める成分である。さらに、Ｋ２Ｏは、耐失透性を改善する成分でもある。Ｋ２Ｏの含有量が多過ぎると、熱膨張係数が高くなり過ぎて、耐熱衝撃性が低下したり、周辺材料の熱膨張係数に整合させ難くなる。また、Ｋ２Ｏの含有量が多過ぎると、歪点が低下し過ぎたり、ガラス組成の成分バランスが損なわれて、逆に耐失透性が低下する傾向がある。上記点を考慮すると、Ｋ２Ｏの上限範囲は１０％以下、８％以下、７％以下、６％以下、特に５％以下が好ましい。一方、圧縮応力層の厚みを大きくするためには、Ｋ２Ｏの下限範囲は０．１％以上、０．５％以上、１％以上、特に２％以上が好ましい。 K 2 O is a component that improves ion exchange performance, and is a component that has a high effect of increasing the thickness of the compressive stress layer among alkali metal oxides. K 2 O is a component that lowers the high-temperature viscosity and improves the meltability and moldability. Furthermore, K 2 O is also a component that improves devitrification resistance. When the content of K 2 O is too large, the thermal expansion coefficient becomes too high, the thermal shock resistance becomes difficult to match or decreased, the thermal expansion coefficient with those of peripheral materials. If the content of K 2 O is too large, or too low the strain point, it is impaired balance of components glass composition, devitrification resistance conversely tends to decrease. Considering the above points, the upper limit range of K 2 O is preferably 10% or less, 8% or less, 7% or less, 6% or less, and particularly preferably 5% or less. On the other hand, in order to increase the thickness of the compressive stress layer, the lower limit range of K 2 O is preferably 0.1% or more, 0.5% or more, 1% or more, particularly 2% or more.
上記成分以外にも下記の成分をガラス組成中に導入してもよい。 In addition to the above components, the following components may be introduced into the glass composition.
ＭｇＯ＋ＣａＯ＋ＳｒＯ＋ＢａＯ（ＭｇＯ、ＣａＯ、ＳｒＯ、ＢａＯの合量）は、高温粘度を低下させて、溶融性や成形性を高めたり、歪点やヤング率を高める成分であり、その含有量は０〜１５％、０〜１０％、０〜６％、特に０〜５％が好ましい。しかし、ＭｇＯ＋ＣａＯ＋ＳｒＯ＋ＢａＯの含有量が多過ぎると、密度や熱膨張係数が高くなり過ぎたり、耐失透性が低下したり、イオン交換性能が低下する傾向がある。 MgO + CaO + SrO + BaO (total amount of MgO, CaO, SrO, BaO) is a component that lowers the high-temperature viscosity to increase meltability and formability, and increases the strain point and Young's modulus, and its content is 0 to 15%. 0 to 10%, 0 to 6%, particularly 0 to 5% is preferable. However, when there is too much content of MgO + CaO + SrO + BaO, there exists a tendency for a density and a thermal expansion coefficient to become high too much, devitrification resistance to fall, or ion exchange performance to fall.
ＭｇＯは、高温粘度を低下させて、溶融性や成形性を高めたり、歪点やヤング率を高める成分であり、特にアルカリ土類金属酸化物の中では、イオン交換性能を向上させる効果が高い成分であり、その含有量は０〜１０％、０〜６％、０〜４％、特に０〜３％が好ましい。しかし、ＭｇＯの含有量が多過ぎると、密度や熱膨張係数が高くなり過ぎたり、ガラスが失透しやすくなる。 MgO is a component that lowers the viscosity at high temperature to increase the meltability and formability, and increases the strain point and Young's modulus. Especially in alkaline earth metal oxides, the effect of improving ion exchange performance is high. It is a component, and its content is preferably 0 to 10%, 0 to 6%, 0 to 4%, particularly preferably 0 to 3%. However, when there is too much content of MgO, a density and a thermal expansion coefficient will become high too much, or it will become easy to devitrify glass.
ＣａＯは、高温粘度を低下させて、溶融性や成形性を高めたり、歪点やヤング率を高める成分である。また、アルカリ土類金属酸化物の中では、イオン交換性能を向上させる効果が比較的高い成分であり、その含有量は０〜１０％、０〜８％、０〜６％、特に０〜３％が好ましい。しかし、ＣａＯの含有量が多過ぎると、密度や熱膨張係数が高くなり過ぎたり、ガラスが失透しやすくなる。また、ガラス組成の成分バランスが損なわれて、逆にイオン交換性能が低下する場合がある。 CaO is a component that lowers the high-temperature viscosity to increase meltability and moldability, and increases the strain point and Young's modulus. Further, among alkaline earth metal oxides, it is a component having a relatively high effect of improving ion exchange performance, and its content is 0 to 10%, 0 to 8%, 0 to 6%, particularly 0 to 3%. % Is preferred. However, when there is too much content of CaO, a density and a thermal expansion coefficient will become high too much, or it will become easy to devitrify glass. Moreover, the component balance of a glass composition may be impaired, and on the contrary, ion exchange performance may fall.
ＳｒＯやＢａＯは、高温粘度を低下させて、溶融性や成形性を高めたり、歪点やヤング率を高める成分であり、その含有量は各々０〜５％が好ましい。ＳｒＯやＢａＯの含有量が多過ぎると、イオン交換性能が低下する傾向があることに加えて、密度や熱膨張係数が高くなり過ぎたり、ガラスが失透しやすくなる。ＳｒＯの含有量は３％以下、２％以下、１％以下、０．５％以下、特に０．１％以下が望ましい。また、ＢａＯの含有量は３％以下、２％以下、１％以下、０．８％以下、０．５％以下、特に０．１％以下が望ましい。 SrO and BaO are components that lower the viscosity at high temperature to increase the meltability and moldability, and increase the strain point and Young's modulus, and their content is preferably 0 to 5%. When there is too much content of SrO and BaO, in addition to the tendency for ion exchange performance to fall, a density and a thermal expansion coefficient will become high too much, or it will become easy to devitrify glass. The SrO content is preferably 3% or less, 2% or less, 1% or less, 0.5% or less, and particularly preferably 0.1% or less. The BaO content is preferably 3% or less, 2% or less, 1% or less, 0.8% or less, 0.5% or less, and particularly preferably 0.1% or less.
ＳｒＯ＋ＢａＯ（ＳｒＯ、ＢａＯの合量）を０〜５％、０〜３％、０〜２．５％、０〜２％、０〜１％、特に０〜０．１％に規制すれば、イオン交換性能がより効果的に向上する。既述の通り、ＳｒＯ＋ＢａＯは、イオン交換反応を阻害する作用があるため、ＳｒＯ＋ＢａＯが過剰であると、強化ガラスの機械的強度を高め難くなる。 If SrO + BaO (total amount of SrO and BaO) is regulated to 0 to 5%, 0 to 3%, 0 to 2.5%, 0 to 2%, 0 to 1%, particularly 0 to 0.1%, ions Exchange performance improves more effectively. As described above, SrO + BaO has an action of inhibiting the ion exchange reaction. Therefore, if SrO + BaO is excessive, it is difficult to increase the mechanical strength of the tempered glass.
ＭｇＯ＋ＣａＯ＋ＳｒＯ＋ＢａＯをＬｉ２Ｏ＋Ｎａ２Ｏ＋Ｋ２Ｏで除した値、つまり質量分率（ＭｇＯ＋ＣａＯ＋ＳｒＯ＋ＢａＯ）／（Ｌｉ２Ｏ＋Ｎａ２Ｏ＋Ｋ２Ｏ）が大きくなると、耐失透性が低下する傾向が現れる。よって、質量分率（ＭｇＯ＋ＣａＯ＋ＳｒＯ＋ＢａＯ）／（Ｌｉ２Ｏ＋Ｎａ２Ｏ＋Ｋ２Ｏ）は０．５以下、０．４以下、特に０．３以下が望ましい。 When the value obtained by dividing MgO + CaO + SrO + BaO by Li 2 O + Na 2 O + K 2 O, that is, the mass fraction (MgO + CaO + SrO + BaO) / (Li 2 O + Na 2 O + K 2 O) increases, the devitrification resistance tends to decrease. Therefore, the mass fraction (MgO + CaO + SrO + BaO) / (Li 2 O + Na 2 O + K 2 O) is preferably 0.5 or less, 0.4 or less, and particularly preferably 0.3 or less.
ＺｎＯは、イオン交換性能を向上させる成分であり、特に圧縮応力層の圧縮応力値を高める効果が大きい成分であるとともに、低温粘性を低下させずに高温粘性を低下させる成分であり、その含有量は０〜１０％、０〜５％、０〜３％、特に０〜１％が好ましい。しかし、ＺｎＯの含有量が多過ぎると、ガラスが分相したり、耐失透性が低下したり、密度が高くなり過ぎる。 ZnO is a component that improves the ion exchange performance, and in particular, is a component that has a large effect of increasing the compressive stress value of the compressive stress layer, and is a component that lowers the high temperature viscosity without lowering the low temperature viscosity. Is preferably 0 to 10%, 0 to 5%, 0 to 3%, particularly preferably 0 to 1%. However, when there is too much content of ZnO, glass will phase-divide, devitrification resistance will fall, or a density will become high too much.
以下のように質量分率を規制すれば、熱加工性（低い軟化点）と、耐失透性と、イオン交換性能を高いレベルで両立させることができる。 If the mass fraction is regulated as follows, thermal workability (low softening point), devitrification resistance, and ion exchange performance can be achieved at a high level.
第一に、質量分率Ｎａ２Ｏ／ＳｉＯ２は０．０５〜０．５が好ましい。質量分率Ｎａ２Ｏ／ＳｉＯ２が０．０５より小さくなると、軟化点が高くなり過ぎたり、高温粘性が高くなり過ぎて、泡品位が低下したり、液相温度が高くなったり、イオン交換性能が低下しやすくなる。一方、質量分率Ｎａ２Ｏ／ＳｉＯ２が０．５より大きくなると、熱膨張係数や密度が高くなり過ぎたり、歪点が低下し過ぎて、逆にイオン交換性能が低下する場合がある。質量分率Ｎａ２Ｏ／ＳｉＯ２の下限範囲は０．１以上、０．１５以上、０．２以上、０．２２以上、特に０．２４以上が好ましく、上限範囲は０．５以下、０．４５以下、０．４以下、０．３５以下、０．３２以下、特に０．３以下が好ましい。 First, the mass fraction Na 2 O / SiO 2 is preferably 0.05 to 0.5. When the mass fraction Na 2 O / SiO 2 is smaller than 0.05, the softening point becomes too high, the high-temperature viscosity becomes too high, the foam quality is lowered, the liquidus temperature becomes high, or ion exchange The performance tends to decrease. On the other hand, if the mass fraction Na 2 O / SiO 2 is greater than 0.5, the thermal expansion coefficient and density may be too high, or the strain point may be too low, and the ion exchange performance may be reduced. The lower limit range of the mass fraction Na 2 O / SiO 2 is 0.1 or more, 0.15 or more, 0.2 or more, 0.22 or more, particularly preferably 0.24 or more, and the upper limit range is 0.5 or less, 0 .45 or less, 0.4 or less, 0.35 or less, 0.32 or less, and particularly preferably 0.3 or less.
第二に、質量分率Ａｌ２Ｏ３／ＳｉＯ２は０．０５〜０．５が好ましい。質量分率Ａｌ２Ｏ３／ＳｉＯ２が０．０５より小さくなると、所望のイオン交換性能を得難くなる。また、質量分率Ａｌ２Ｏ３／ＳｉＯ２が０．５より大きくなると、軟化点が高くなり過ぎたり、高温粘性が高くなり過ぎて、泡品位が低下したり、液相温度が高くなる。質量分率Ａｌ２Ｏ３／ＳｉＯ２の下限範囲は０．１以上、０．１５以上、０．２以上、０．２２以上、特に０．２４以上が好ましく、上限範囲は０．４５以下、０．４以下、０．３５以下、０．３２以下、０．３以下、０．２９以下、０．２８以下、特に０．２７以下が好ましい。 Secondly, the mass fraction Al 2 O 3 / SiO 2 is preferably 0.05 to 0.5. When the mass fraction Al 2 O 3 / SiO 2 is smaller than 0.05, it is difficult to obtain desired ion exchange performance. Further, when the mass fraction Al 2 O 3 / SiO 2 is greater than 0.5, or too high softening point, too high temperature viscosity, or reduces the bubble quality, the liquidus temperature increases. The lower limit range of the mass fraction Al 2 O 3 / SiO 2 is preferably 0.1 or more, 0.15 or more, 0.2 or more, 0.22 or more, particularly preferably 0.24 or more, and the upper limit range is 0.45 or less. 0.4 or less, 0.35 or less, 0.32 or less, 0.3 or less, 0.29 or less, 0.28 or less, and particularly 0.27 or less are preferable.
第三に、質量分率ＣａＯ／ＭｇＯは０〜３、０〜２、特に０〜１が好ましい。質量分率ＣａＯ／ＭｇＯが３より大きくなると、イオン交換性能が低下する傾向にあり、特に短時間で圧縮応力層の厚みを大きくすることが困難になる。 Third, the mass fraction CaO / MgO is preferably 0 to 3, 0 to 2, particularly preferably 0 to 1. When the mass fraction CaO / MgO is larger than 3, the ion exchange performance tends to be lowered, and it is particularly difficult to increase the thickness of the compressive stress layer in a short time.
ＺｒＯ２は、イオン交換性能を顕著に向上させるとともに、液相粘度付近の粘性や歪点を高める成分であり、その含有量は０〜１０％、０〜９％、０．００１〜８％、０．０１〜７％、１〜７％、２〜７％、３〜６％、特に３〜５％が好ましい。ＺｒＯ２の含有量が多過ぎると、耐失透性が極端に低下する場合がある。 ZrO 2 is a component that significantly improves the ion exchange performance and increases the viscosity and strain point in the vicinity of the liquid phase viscosity, and its content is 0 to 10%, 0 to 9%, 0.001 to 8%, 0.01 to 7%, 1 to 7%, 2 to 7%, 3 to 6%, particularly 3 to 5% are preferable. When the content of ZrO 2 is too high, there are cases where the devitrification resistance is extremely lowered.
Ｂ２Ｏ３は、液相温度、高温粘度、密度を低下させるとともに、イオン交換性能、特に圧縮応力層の圧縮応力値を高める成分であり、その含有量は０〜１０％、０〜５％、０〜３％、特に０〜２％が好ましい。Ｂ２Ｏ３の含有量が多過ぎると、イオン交換処理によりガラスの表面にヤケが発生したり、耐水性が低下したり、液相粘度が低下する虞がある。また、Ｂ２Ｏ３の含有量が多過ぎると、圧縮応力層の厚みが小さくなる傾向がある。 B 2 O 3 is a component that lowers the liquidus temperature, high-temperature viscosity, and density and increases ion exchange performance, particularly the compressive stress value of the compressive stress layer, and its content is 0 to 10%, 0 to 5%. 0 to 3%, particularly 0 to 2% is preferable. When the content of B 2 O 3 is too large, or occurs burnt on the surface of the glass by ion exchange treatment, or water resistance is lowered, the liquidus viscosity may be decreased. Further, when the content of B 2 O 3 is too large, the thickness of the compressive stress layer tends to decrease.
ＴｉＯ２は、イオン交換性能を向上させる成分であるとともに、高温粘度を低下させる成分であるが、その含有量が多過ぎると、ガラスが着色したり、耐失透性が低下しやすくなるため、その含有量は１％以下、０．５％以下、特に０．１％以下が好ましい。 TiO 2 is a component that improves the ion exchange performance and is a component that lowers the high temperature viscosity, but if its content is too large, the glass is colored or the devitrification resistance is likely to be reduced. The content is preferably 1% or less, 0.5% or less, particularly preferably 0.1% or less.
Ｐ２Ｏ５は、イオン交換性能を高める成分であり、特に圧縮応力層の厚みを大きくする効果が大きい成分であり、その含有量は８％以下、５％以下、４％以下、２％以下、０．５％以下、特に０．１％以下が好ましい。しかし、Ｐ２Ｏ５の含有量が多過ぎると、ガラスが分相したり、耐水性が低下しやすくなる。 P 2 O 5 is a component that enhances the ion exchange performance, and is a component that is particularly effective in increasing the thickness of the compressive stress layer, and its content is 8% or less, 5% or less, 4% or less, 2% or less. 0.5% or less, particularly 0.1% or less is preferable. However, when the content of P 2 O 5 is too large, or glass phase separation, the water resistance tends to lower.
清澄剤として、Ａｓ２Ｏ３、Ｓｂ２Ｏ３、ＣｅＯ２、ＳｎＯ２、Ｆ、Ｃｌ、ＳＯ３の群から選択された一種または二種以上を０〜３％添加することができる。ただし、Ａｓ２Ｏ３、Ｓｂ２Ｏ３、Ｆ、特にＡｓ２Ｏ３、Ｓｂ２Ｏ３は、環境的観点から、その使用を極力控えることが好ましく、各々の含有量は０．１％未満が好ましい。好ましい清澄剤は、ＳｎＯ２、ＳＯ３、Ｃｌである。ＳｎＯ２の含有量は０〜１％、０．０１〜０．５％、特に０．０５〜０．４％が好ましい。ＳｎＯ２の含有量が１％より多いと、耐失透性が低下しやすくなる。ＳＯ３の含有量は０〜０．１％、０．０００１〜０．１％、０．０００３〜０．０８％、０．０００５〜０．０５％、特に０．００１〜０．０３％が好ましい。ＳＯ３の含有量が０．１％より多いと、溶融時にＳＯ３がリボイルして、泡品位が低下しやすくなる。Ｃｌの含有量は０〜０．５％、０．００５〜０．３％、０．０１〜０．２％、０．０１〜０．１％、特に０．０１〜０．０９％が好ましい。Ｃｌの含有量が０．５％より多いと、強化ガラス上に金属配線パターン等を形成した時に金属配線が腐食しやすくなる。 As a fining agent, 0 to 3% of one or more selected from the group of As 2 O 3 , Sb 2 O 3 , CeO 2 , SnO 2 , F, Cl, and SO 3 can be added. However, As 2 O 3 , Sb 2 O 3 , F, particularly As 2 O 3 , Sb 2 O 3 are preferably refrained from use as much as possible from an environmental point of view, and each content is less than 0.1% Is preferred. Preferred fining agents are SnO 2, SO 3, Cl. The SnO 2 content is preferably 0 to 1%, 0.01 to 0.5%, particularly preferably 0.05 to 0.4%. When the content of SnO 2 is more than 1%, the devitrification resistance tends to decrease. The content of SO 3 is 0 to 0.1%, 0.0001 to 0.1%, 0.0003 to 0.08%, 0.0005 to 0.05%, particularly 0.001 to 0.03%. preferable. When the content of SO 3 is more than 0.1%, SO 3 is reboiled at the time of melting, and the bubble quality tends to be lowered. The Cl content is preferably 0 to 0.5%, 0.005 to 0.3%, 0.01 to 0.2%, 0.01 to 0.1%, and particularly preferably 0.01 to 0.09%. . When the Cl content is more than 0.5%, the metal wiring is easily corroded when a metal wiring pattern or the like is formed on the tempered glass.
Ｎｂ２Ｏ５やＬａ２Ｏ３等の希土類酸化物は、ヤング率を高める成分である。しかし、原料自体のコストが高く、また多量に添加すると、耐失透性が低下しやすくなる。よって、希土類酸化物の含有量は３％以下、２％以下、１％以下、０．５％以下、特に０．１％以下が好ましい。 Rare earth oxides such as Nb 2 O 5 and La 2 O 3 are components that increase the Young's modulus. However, the cost of the raw material itself is high, and if it is added in a large amount, the devitrification resistance tends to be lowered. Therefore, the rare earth oxide content is preferably 3% or less, 2% or less, 1% or less, 0.5% or less, and particularly preferably 0.1% or less.
Ｃｏ、Ｎｉ等の遷移金属酸化物は、ガラスを強く着色させ、透過率を低下させる成分である。よって、遷移金属酸化物の含有量が０．５％以下、０．１％以下、０．０５％以下になるように、ガラス原料の使用量を調整することが望ましい。 Transition metal oxides such as Co and Ni are components that strongly color the glass and lower the transmittance. Therefore, it is desirable to adjust the usage amount of the glass raw material so that the content of the transition metal oxide is 0.5% or less, 0.1% or less, or 0.05% or less.
ＰｂＯやＢｉ２Ｏ３は、環境的観点から、使用は極力控えるべきであり、その含有量は０．１％未満が好ましい。 PbO and Bi 2 O 3 should be used as little as possible from an environmental point of view, and their content is preferably less than 0.1%.
各成分の好適な含有範囲を適宜選択し、好適なガラス組成範囲とすることができるが、その中でも、より好適なガラス組成範囲は、以下の通りである。
（１）質量％で、ＳｉＯ２ ４５〜７５％、Ａｌ２Ｏ３ ０〜３０％、Ｌｉ２Ｏ＋Ｎａ２Ｏ＋Ｋ２Ｏ ０〜３０％含有、
（２）質量％で、ＳｉＯ２ ４５〜７５％、Ａｌ２Ｏ３ １０〜３０％、Ｌｉ２Ｏ＋Ｎａ２Ｏ＋Ｋ２Ｏ ０〜３０％含有し、且つ質量分率Ｎａ２Ｏ／ＳｉＯ２が０．０５〜０．５、質量分率Ａｌ２Ｏ３／ＳｉＯ２が０．０５〜０．５、質量分率ＣａＯ／ＭｇＯが０〜３、
（３）質量％で、ＳｉＯ２ ４５〜７５％、Ａｌ２Ｏ３ １０〜３０％、Ｌｉ２Ｏ＋Ｎａ２Ｏ＋Ｋ２Ｏ ０〜３０％含有し、且つ質量分率Ｎａ２Ｏ／ＳｉＯ２が０．１〜０．４、質量分率Ａｌ２Ｏ３／ＳｉＯ２が０．１〜０．４、質量分率ＣａＯ／ＭｇＯが０〜２、
（４）質量％で、ＳｉＯ２ ４５〜７５％、Ａｌ２Ｏ３ １０〜３０％、Ｌｉ２Ｏ ０〜１０％、Ｎａ２Ｏ ５〜２０％ Ｋ２Ｏ ０〜１０％含有し、且つ質量分率Ｎａ２Ｏ／ＳｉＯ２が０．２〜０．３、質量分率Ａｌ２Ｏ３／ＳｉＯ２が０．２〜０．３、質量分率ＣａＯ／ＭｇＯが０〜１、
（５）質量％で、ＳｉＯ２ ５２〜７０％、Ａｌ２Ｏ３ １０〜２５％、Ｌｉ２Ｏ ０〜６％、Ｎａ２Ｏ ５〜２０％、Ｋ２Ｏ ０〜１０％含有し、且つ質量分率Ｎａ２Ｏ／ＳｉＯ２が０．２〜０．３、質量分率Ａｌ２Ｏ３／ＳｉＯ２が０．２〜０．３、質量分率ＣａＯ／ＭｇＯが０〜１、
（６）質量％で、ＳｉＯ２ ５２〜６５％、Ａｌ２Ｏ３ １０〜２０％、Ｌｉ２Ｏ ０〜２％、Ｎａ２Ｏ １０〜２０％、Ｋ２Ｏ ０〜５％、ＺｎＯ ０〜１％，ＴｉＯ２ ０〜０．１％含有し、且つ質量分率Ｎａ２Ｏ／ＳｉＯ２が０．２１〜０．２８、質量分率Ａｌ２Ｏ３／ＳｉＯ２が０．２１〜０．２８、質量分率ＣａＯ／ＭｇＯが０〜１。
Although the suitable content range of each component can be selected suitably and it can be set as the suitable glass composition range, the more suitable glass composition range is as follows among them.
(1) in mass%, SiO 2 45~75%, Al 2 O 3 0~30%, Li 2 O + Na 2 O + K 2 O 0~30% containing,
(2) in mass%, SiO 2 45~75%, Al 2 O 3 10~30%, Li 2 O + Na 2 O + K 2 O containing 0-30%, and the mass fraction Na 2 O / SiO 2 is 0. 05 to 0.5, mass fraction Al 2 O 3 / SiO 2 is 0.05 to 0.5, mass fraction CaO / MgO is 0 to 3,
(3) mass%, SiO 2 45~75%, Al 2 O 3 10~30%, Li 2 O + Na 2 O + K 2 O containing 0-30%, and the mass fraction Na 2 O / SiO 2 is 0. 1 to 0.4, mass fraction Al 2 O 3 / SiO 2 is 0.1 to 0.4, mass fraction CaO / MgO is 0 to 2,
(4) in mass%, SiO 2 45~75%, Al 2 O 3 10~30%, Li 2 O 0~10%, Na 2 O 5~20% K 2 O containing 0 to 10%, and the mass The fraction Na 2 O / SiO 2 is 0.2 to 0.3, the mass fraction Al 2 O 3 / SiO 2 is 0.2 to 0.3, the mass fraction CaO / MgO is 0 to 1,
(5) in mass%, SiO 2 52~70%, Al 2 O 3 10~25%, Li 2 O 0~6%, Na 2 O 5~20%, K 2 O containing 0-10%, and The mass fraction Na 2 O / SiO 2 is 0.2 to 0.3, the mass fraction Al 2 O 3 / SiO 2 is 0.2 to 0.3, the mass fraction CaO / MgO is 0 to 1,
(6) mass%, SiO 2 52~65%, Al 2 O 3 10~20%, Li 2 O 0~2%, Na 2 O 10~20%, K 2 O 0~5%, ZnO 0~ 1%, TiO 2 0 to 0.1%, and a mass fraction Na 2 O / SiO 2 of 0.21 to 0.28, a mass fraction of Al 2 O 3 / SiO 2 of 0.21 to 0. 28, mass fraction CaO / MgO is 0-1.
本発明の強化ガラスの製造方法において、密度が２．７ｇ／ｃｍ３以下、２．６ｇ／ｃｍ３以下、特に２．５５ｇ／ｃｍ３以下になるようにガラス原料を調合することが好ましい。密度が小さい程、ガラスを軽量化することができる。ここで、「密度」とは、周知のアルキメデス法で測定した値を指す。密度を低下させるには、ガラス組成中のＳｉＯ２、Ｐ２Ｏ５、Ｂ２Ｏ３の含有量を増加、或いはアルカリ金属酸化物、アルカリ土類金属酸化物、ＺｎＯ、ＺｒＯ２、ＴｉＯ２の含有量を低減すればよい。 In the manufacturing method of the tempered glass of this invention, it is preferable to prepare a glass raw material so that a density may be 2.7 g / cm < 3 > or less, 2.6 g / cm < 3 > or less, especially 2.55 g / cm < 3 > or less. The smaller the density, the lighter the glass. Here, “density” refers to a value measured by the well-known Archimedes method. In order to reduce the density, the content of SiO 2 , P 2 O 5 , B 2 O 3 in the glass composition is increased, or alkali metal oxide, alkaline earth metal oxide, ZnO, ZrO 2 , TiO 2 What is necessary is just to reduce content.
本発明の強化ガラスの製造方法において、歪点が４５０℃以上、４６０℃以上、４８０℃以上、５００℃以上、５１０℃以上、特に５２０℃以上になるようにガラス原料を調合することが好ましい。歪点が高い程、耐熱性が向上し、強化ガラスを熱処理しても、圧縮応力層が消失し難くなる。また、歪点が高いと、イオン交換処理で応力緩和が生じ難くなるため、高い圧縮応力値を得やすくなる。歪点を高くするためには、ガラス組成中のアルカリ金属酸化物、特にＬｉ２Ｏの含有量を低減、或いはアルカリ土類金属酸化物、Ａｌ２Ｏ３、ＺｒＯ２、Ｐ２Ｏ５の含有量を増加すればよい。 In the method for producing tempered glass of the present invention, it is preferable to prepare the glass raw material so that the strain point is 450 ° C. or higher, 460 ° C. or higher, 480 ° C. or higher, 500 ° C. or higher, 510 ° C. or higher, particularly 520 ° C. or higher. The higher the strain point, the better the heat resistance, and the compressive stress layer is less likely to disappear even if the tempered glass is heat-treated. In addition, when the strain point is high, stress relaxation is less likely to occur in the ion exchange treatment, so that a high compressive stress value is easily obtained. In order to increase the strain point, the content of alkali metal oxide, particularly Li 2 O in the glass composition is reduced, or the content of alkaline earth metal oxide, Al 2 O 3 , ZrO 2 , P 2 O 5 Just increase the amount.
本発明の強化ガラスの製造方法において、軟化点が８６０℃以下、８５０℃以下、８４０℃以下、８３０℃以下、８２０℃以下、８００℃以下、７８０℃以下、７７０℃以下、特に７６０℃以下になるようにガラス原料を調合することが好ましい。軟化点が低い程、熱加工しやすくなり、また熱加工を低温で行うことができる。また、プレス成形する場合においても、軟化点が低い程、成形金型の負担が小さくなるため、成形金型の寿命が長くなり、成形コストが低下しやすくなる。 In the method for producing tempered glass of the present invention, the softening point is 860 ° C. or lower, 850 ° C. or lower, 840 ° C. or lower, 830 ° C. or lower, 820 ° C. or lower, 800 ° C. or lower, 780 ° C. or lower, 770 ° C. or lower, especially 760 ° C. or lower. It is preferable to prepare the glass raw material so as to be. The lower the softening point, the easier the heat processing is possible, and the heat processing can be performed at a low temperature. Also in the case of press molding, the lower the softening point, the smaller the burden on the molding die, so the life of the molding die becomes longer and the molding cost tends to decrease.
本発明の強化ガラスの製造方法において、高温粘度１０２．５ｄＰａ・ｓに相当する温度が１５００℃以下、１４５０℃以下、１４３０℃以下、１４２０℃以下、特に１４００℃以下になるようにガラス原料を調合することが好ましい。高温粘度１０２．５ｄＰａ・ｓに相当する温度が低い程、溶融炉等のガラス製造設備に与える負担が小さくなるとともに、ガラスの泡品位を向上させることができ、結果として、ガラスの製造コストを低廉化することができる。なお、高温粘度１０２．５ｄＰａ・ｓに相当する温度は、溶融温度に相当しており、高温粘度１０２．５ｄＰａ・ｓに相当する温度が低い程、低温でガラスを溶融することができる。１０２．５ｄＰａ・ｓに相当する温度を低下させるには、ガラス組成中のアルカリ金属酸化物、アルカリ土類金属酸化物、ＺｎＯ、Ｂ２Ｏ３、ＴｉＯ２の含有量を増加、或いはＳｉＯ２、Ａｌ２Ｏ３の含有量を低減すればよい。 In the method for producing tempered glass of the present invention, the glass raw material is adjusted so that the temperature corresponding to the high temperature viscosity of 10 2.5 dPa · s is 1500 ° C. or lower, 1450 ° C. or lower, 1430 ° C. or lower, 1420 ° C. or lower, particularly 1400 ° C. or lower. Is preferably prepared. The lower the temperature corresponding to a high temperature viscosity of 10 2.5 dPa · s, the smaller the burden on glass manufacturing equipment such as a melting furnace, and the higher the bubble quality of the glass, resulting in glass manufacturing costs. Can be reduced. The temperature corresponding to the high temperature viscosity of 10 2.5 dPa · s corresponds to the melting temperature, and the lower the temperature corresponding to the high temperature viscosity of 10 2.5 dPa · s, the more the glass can be melted at a low temperature. it can. To lower the temperature corresponding to 10 2.5 dPa · s, increase the content of alkali metal oxide, alkaline earth metal oxide, ZnO, B 2 O 3 , TiO 2 in the glass composition, or SiO 2 , The content of Al 2 O 3 may be reduced.
本発明の強化ガラスの製造方法において、熱膨張係数が７０〜１１０×１０−７／℃、７５〜１００×１０−７／℃、特に８０〜１００×１０−７／℃になるようにガラス原料を調合することが好ましい。熱膨張係数を上記範囲とすれば、金属、有機系接着剤等の部材の熱膨張係数に整合させやすくなり、金属、有機系接着剤等の部材の剥離を防止することができる。熱膨張係数を高めるには、ガラス組成中のアルカリ金属酸化物、アルカリ土類金属酸化物の含有量を増加すればよく、逆に熱膨張係数を低下させるには、ガラス組成中のアルカリ金属酸化物、アルカリ土類金属酸化物の含有量を低減すればよい。 In the method for producing tempered glass of the present invention, the glass raw material has a thermal expansion coefficient of 70 to 110 × 10 −7 / ° C., 75 to 100 × 10 −7 / ° C., particularly 80 to 100 × 10 −7 / ° C. Is preferably prepared. When the thermal expansion coefficient is in the above range, it becomes easy to match the thermal expansion coefficient of a member such as a metal or an organic adhesive, and it is possible to prevent peeling of the member such as a metal or an organic adhesive. In order to increase the coefficient of thermal expansion, it is only necessary to increase the content of alkali metal oxides and alkaline earth metal oxides in the glass composition. Conversely, in order to decrease the coefficient of thermal expansion, alkali metal oxidation in the glass composition is required. And the content of alkaline earth metal oxides may be reduced.
本発明の強化ガラスの製造方法において、液相温度が１２００℃以下、１０５０℃以下、１０００℃以下、９５０℃以下、９００℃以下、特に８６０℃以下になるようにガラス原料を調合することが好ましい。液相温度が低い程、耐失透性、熱加工性、成形性に優れている。特に、液相温度が低い程、ガラス中から結晶が析出し難いため、熱加工を比較的低温で行うことができ、これに伴い成形金型の寿命を高めることができる。液相温度を低下させるには、ガラス組成中のＮａ２Ｏ、Ｋ２Ｏ、Ｂ２Ｏ３の含有量を増加、或いはＡｌ２Ｏ３、Ｌｉ２Ｏ、ＭｇＯ、ＺｎＯ、ＴｉＯ２、ＺｒＯ２の含有量を低減すればよい。 In the method for producing tempered glass of the present invention, it is preferable to prepare the glass raw material so that the liquidus temperature is 1200 ° C. or lower, 1050 ° C. or lower, 1000 ° C. or lower, 950 ° C. or lower, 900 ° C. or lower, particularly 860 ° C. or lower. . The lower the liquidus temperature, the better the devitrification resistance, thermal processability and moldability. In particular, the lower the liquidus temperature, the more difficult it is for crystals to precipitate out of the glass, so heat processing can be performed at a relatively low temperature, and the life of the molding die can be increased accordingly. To lower the liquidus temperature, the content of Na 2 O, K 2 O, B 2 O 3 in the glass composition is increased, or Al 2 O 3 , Li 2 O, MgO, ZnO, TiO 2 , ZrO 2. The content of can be reduced.
本発明の強化ガラスの製造方法において、液相粘度が１０４．０ｄＰａ・ｓ以上、１０４．５ｄＰａ・ｓ以上、１０５．０ｄＰａ・ｓ以上、１０５．２ｄＰａ・ｓ以上、１０５．３ｄＰａ・ｓ以上、１０５．５ｄＰａ・ｓ以上、１０５．７ｄＰａ・ｓ以上、１０５．８ｄＰａ・ｓ以上、１０６．０ｄＰａ・ｓ以上、１０６．２．ｄＰａ・ｓ以上になるようにガラス原料を調合することが好ましい。液相粘度が高い程、耐失透性や成形性に優れている。液相粘度を高めるには、ガラス組成中のＮａ２Ｏ、Ｋ２Ｏの含有量を増加、或いはＡｌ２Ｏ３、Ｌｉ２Ｏ、ＭｇＯ、ＺｎＯ、ＴｉＯ２、ＺｒＯ２の含有量を低減すればよい。 In the method for producing tempered glass of the present invention, the liquid phase viscosity is 10 4.0 dPa · s or more, 10 4.5 dPa · s or more, 10 5.0 dPa · s or more, 10 5.2 dPa · s or more, 10 5.3 dPa · s or more, 10 5.5 dPa · s or more, 10 5.7 dPa · s or more, 10 5.8 dPa · s or more, 10 6.0 dPa · s or more, 10 6.2. It is preferable to prepare the glass raw material so as to be dPa · s or more. The higher the liquidus viscosity, the better the devitrification resistance and moldability. To increase the liquid phase viscosity, increase the content of Na 2 O, K 2 O in the glass composition, or decrease the content of Al 2 O 3 , Li 2 O, MgO, ZnO, TiO 2 , ZrO 2. That's fine.
一般的に、ガラスは、ガラス原料を連続溶融炉に投入し、このガラス原料を１５００〜１６００℃で加熱溶融し、清澄した後、成形装置に供給した上で溶融ガラスを成形し、徐冷することにより製造することができる。 In general, for glass, a glass raw material is charged into a continuous melting furnace, the glass raw material is heated and melted at 1500 to 1600 ° C., clarified, then supplied to a molding apparatus, and then the molten glass is formed and gradually cooled. Can be manufactured.
本発明の強化ガラスは、オーバーフローダウンドロー法で溶融ガラスを平板形状のガラスに成形されてなる。このようにすれば、未研磨で表面品位が良好な平板形状のガラスを製造することができる。その理由は、オーバーフローダウンドロー法の場合、ガラスの表面となるべき面は樋状耐火物に接触せず、自由表面の状態で成形されるからである。ここで、オーバーフローダウンドロー法は、溶融ガラスを耐熱性の樋状構造物の両側から溢れさせて、溢れた溶融ガラスを樋状構造物の下端で合流させながら、下方に延伸成形して平板形状のガラスを製造する方法である。樋状構造物の構造や材質は、ガラスの寸法や表面精度を所望の状態とし、所望の品位を実現できるものであれば、特に限定されない。また、下方への延伸成形を行うためにガラスに対してどのような方法で力を印加するものであってもよい。例えば、充分に大きい幅を有する耐熱性ロールをガラスに接触させた状態で回転させて延伸する方法を採用してもよいし、複数の対になった耐熱性ロールをガラスの端面近傍のみに接触させて延伸する方法を採用してもよい。 The tempered glass of the present invention is formed by forming molten glass into flat glass by an overflow down draw method. By doing so, it is possible to produce a flat plate-shaped glass that is unpolished and has good surface quality. The reason is that in the case of the overflow downdraw method, the surface to be the surface of the glass is not in contact with the bowl-like refractory and is molded in a free surface state. Here, the overflow down draw method is a flat plate shape in which molten glass overflows from both sides of a heat-resistant bowl-shaped structure, and the overflowed molten glass is stretched downward and joined at the lower end of the bowl-shaped structure. It is a method of manufacturing the glass. The structure and material of the bowl-shaped structure are not particularly limited as long as the dimensions and surface accuracy of the glass are in a desired state and a desired quality can be realized. Further, a force may be applied to the glass by any method in order to perform downward stretching. For example, a method may be adopted in which a heat-resistant roll having a sufficiently large width is rotated and stretched in contact with glass, or a plurality of pairs of heat-resistant rolls are contacted only near the end face of the glass. It is also possible to adopt a method of stretching by stretching.
本発明の強化ガラスの製造方法において、基板またはカバーガラスとして用いる場合、強化ガラスの軽量化を図るために、その板厚を３．０ｍｍ以下、１．５ｍｍ以下、０．７ｍｍ以下、０．５ｍｍ以下、特に０．３ｍｍ以下とするのが好ましく、外装部品として用いる場合、強化ガラスの機械的強度を維持するために、その厚みを０．３ｍｍ以上、０．５ｍｍ以上、０．７ｍｍ以上、１．０ｍｍ以上、１．３ｍｍ以上、１．５ｍｍ以上とするのが好ましい。 In the method for producing tempered glass of the present invention, when used as a substrate or cover glass, in order to reduce the weight of the tempered glass, the plate thickness is 3.0 mm or less, 1.5 mm or less, 0.7 mm or less, 0.5 mm. Hereinafter, it is particularly preferably 0.3 mm or less, and when used as an exterior part, in order to maintain the mechanical strength of the tempered glass, the thickness is 0.3 mm or more, 0.5 mm or more, 0.7 mm or more, 1 It is preferably 0.0 mm or more, 1.3 mm or more, or 1.5 mm or more.
本発明の強化ガラスの製造方法において、表面（切断面を除く）の研磨を省略することが好ましい。ガラスの理論強度は、本来非常に高いのであるが、理論強度よりも遥かに低い応力でも破壊に至ることが多い。これは、ガラスの表面にグリフィスフローと呼ばれる小さな欠陥が溶融ガラスの成形後の工程、例えば研磨工程等で生じるからである。よって、研磨を省略すれば、本来の機械的強度を損ない難くなり、強化ガラスが破壊し難くなる。また、本発明の強化ガラスの製造方法において、未研磨の表面の平均表面粗さ（Ｒａ）が１０Å以下、５Å以下、特に２Å以下になるように溶融ガラスを成形することが好ましい。外装部品として用いる場合、このような表面形状であれば、強化ガラスに適度な光沢を付与することができる。「平均表面粗さ（Ｒａ）」は、ＳＥＭＩ Ｄ７−９７「ＦＰＤガラス基板の表面粗さの測定方法」に準拠した方法で測定した値を指す。なお、本発明の強化ガラスにおいて、切断面から破壊に至る事態を防止するため、切断面に面取り加工等を施してもよい。 In the method for producing tempered glass of the present invention, it is preferable to omit the polishing of the surface (excluding the cut surface). The theoretical strength of glass is inherently very high, but breakage often occurs even at a stress much lower than the theoretical strength. This is because a small defect called Griffith flow occurs on the surface of the glass in a process after molding of the molten glass, such as a polishing process. Therefore, if the polishing is omitted, the original mechanical strength is hardly lost, and the tempered glass is hardly broken. Moreover, in the manufacturing method of the tempered glass of this invention, it is preferable to shape | mold molten glass so that the average surface roughness (Ra) of the unpolished surface may be 10 or less, 5 or less, especially 2 or less. When used as an exterior component, such a surface shape can impart an appropriate gloss to the tempered glass. “Average surface roughness (Ra)” refers to a value measured by a method based on SEMI D7-97 “Measurement method of surface roughness of FPD glass substrate”. In the tempered glass of the present invention, a chamfering process or the like may be applied to the cut surface in order to prevent a situation from breaking to the cut surface.
以下、実施例に基づいて本発明を詳細に説明する。 Hereinafter, the present invention will be described in detail based on examples.
表１は、表２に示す実験で用いたガラス試料のガラス組成および特性を示している。 Table 1 shows the glass composition and characteristics of the glass samples used in the experiments shown in Table 2.
表１のガラス試料は、次のようにして作製した。まず、表１に示すガラス組成となるようにガラス原料を調合した後、ガラス原料を溶融し、得られた溶融ガラスをオーバーフローダウンドロー法で平板形状のガラスに成形した。得られたガラスにつき、表１に示す特性を測定した。成形体下部にアニーラーを配置し、アニーラー上部の温度を７００℃、アニーラー下部の温度を４５０℃に設定し、アニーラー内を１２００ｍｍ／分の速度で通過させた。 The glass samples in Table 1 were produced as follows. First, after preparing a glass raw material so that it might become the glass composition shown in Table 1, the glass raw material was fuse | melted and the obtained molten glass was shape | molded by the overflow down draw method into the flat glass. About the obtained glass, the characteristic shown in Table 1 was measured. An annealer was placed at the bottom of the molded body, the temperature at the top of the annealer was set to 700 ° C., the temperature at the bottom of the annealer was set to 450 ° C., and the inside of the annealer was passed at a speed of 1200 mm / min.
密度は、周知のアルキメデス法によって測定した値である。 The density is a value measured by a well-known Archimedes method.
歪点Ｐｓ、徐冷点Ｔａは、ＡＳＴＭ Ｃ３３６の方法に基づいて測定した値である。 The strain point Ps and the annealing point Ta are values measured based on the method of ASTM C336.
軟化点Ｔｓは、ＡＳＴＭ Ｃ３３８の方法に基づいて測定した値である。 The softening point Ts is a value measured based on the method of ASTM C338.
高温粘度１０４．０ｄＰａ・ｓ、１０３．０ｄＰａ・ｓ、１０２．５ｄＰａ・ｓに相当する温度は、白金球引き上げ法で測定した値である。 The temperature corresponding to the high temperature viscosity of 10 4.0 dPa · s, 10 3.0 dPa · s, 10 2.5 dPa · s is a value measured by a platinum ball pulling method.
熱膨張係数は、ディラトメーターで測定した値であり、３０〜３８０℃の温度範囲における平均値である。 The thermal expansion coefficient is a value measured with a dilatometer, and is an average value in a temperature range of 30 to 380 ° C.
液相温度は、ガラスを粉砕し、標準篩３０メッシュ（篩目開き５００μｍ）を通過し、５０メッシュ（篩目開き３００μｍ）に残るガラス粉末を白金ボートに入れ、温度勾配炉中に２４時間保持して、結晶の析出する温度を測定した値である。 The liquid phase temperature is obtained by crushing glass, passing through a standard sieve 30 mesh (a sieve opening of 500 μm), putting the glass powder remaining at 50 mesh (a sieve opening of 300 μm) in a platinum boat, and keeping it in a temperature gradient furnace for 24 hours. Then, the temperature at which the crystal is deposited is measured.
液相粘度は、液相温度におけるガラスの粘度を白金球引き上げ法で測定した値である。 The liquid phase viscosity is a value obtained by measuring the viscosity of glass at the liquid phase temperature by a platinum ball pulling method.
表２は、本発明の実施例を示しており、表中の徐冷点から歪点までの温度域における冷却条件、イオン交換条件で処理した場合にガラス表面に形成される圧縮応力層の圧縮応力値と厚みを示している。なお、１２０℃／分の冷却速度は、本明細書の段落［００８２］に示すアニーラーを通過した際の冷却速度を例示している。また、２℃／分の冷却速度は、一旦、成形した後のガラスを再び徐冷点以上に熱処理し、冷却する際の冷却速度を例示している。また、０．２℃／分の冷却速度は、一旦、成形した後のガラスを再び徐冷点以上に熱処理し、冷却する際の冷却速度、更に言えば、所謂、精密アニールを行ったときの冷却速度を例示している。 Table 2 shows examples of the present invention, and compression of the compressive stress layer formed on the glass surface when treated under cooling conditions and ion exchange conditions in the temperature range from the annealing point to the strain point in the table. The stress value and thickness are shown. The cooling rate of 120 ° C./min exemplifies the cooling rate when passing through the annealer shown in paragraph [0082] of this specification. The cooling rate of 2 ° C./min exemplifies the cooling rate when the glass once formed is heat-treated again above the annealing point and cooled. Further, the cooling rate of 0.2 ° C./min is the cooling rate when the glass once formed is heat-treated again to the annealing point or higher, and more specifically, when so-called precision annealing is performed. The cooling rate is illustrated.
表面応力計（株式会社東芝製ＦＳＭ−６０００）を用いて干渉縞の本数とその間隔を観察し、ガラス表面の圧縮応力値と圧縮応力層の厚みを算出した。算出に際し、各試料の屈折率を１．５２、光学弾性定数を２８［（ｎｍ／ｃｍ）／ＭＰａ］とした。 The number of interference fringes and the distance between the interference fringes were observed using a surface stress meter (FSM-6000 manufactured by Toshiba Corporation), and the compressive stress value on the glass surface and the thickness of the compressive stress layer were calculated. In the calculation, the refractive index of each sample was 1.52, and the optical elastic constant was 28 [(nm / cm) / MPa].
表２から明らかなように、同一のガラス組成、同一条件のイオン交換処理であっても、冷却速度を遅くすれば、圧縮応力層の圧縮応力値を高めることができる。なお、圧縮応力層の厚みは、冷却速度が遅くなると、多少小さくなる傾向にあるが、イオン交換処理の条件を調整すれば、圧縮応力層の圧縮応力値を高めつつ、圧縮応力層の厚みを大きくすることができる。 As is clear from Table 2, even if the ion exchange treatment has the same glass composition and the same conditions, the compression stress value of the compression stress layer can be increased by lowering the cooling rate. The thickness of the compressive stress layer tends to be somewhat smaller when the cooling rate is slow. However, if the ion exchange treatment conditions are adjusted, the thickness of the compressive stress layer can be increased while increasing the compressive stress value of the compressive stress layer. Can be bigger.
なお、本発明の説明の便宜上、オーバーフローダウンドロー法等で成形した平板形状のガラスを冷却しているが、平板形状のガラスを熱加工し、特定形状に変形させたガラス、またガラスを特定形状にプレス成形したガラスも同様の温度域において同様の冷却条件を付与すれば、同様の効果が得られるものと考えられる。 In addition, for convenience of explanation of the present invention, the flat glass formed by the overflow down draw method or the like is cooled. However, the flat glass is heat-processed and deformed into a specific shape, or the glass is in a specific shape. It is considered that the same effect can be obtained by applying the same cooling condition to the glass press-molded in the same temperature range.
本発明の強化ガラスの製造方法は、携帯電話、デジタルカメラ、ＰＤＡ、タッチパネルディスプレイ等のカバーガラスに用いられる強化ガラスの製造方法として好適である。また、本発明の強化ガラスの製造方法は、熱加工を施した携帯電話、モバイルＰＣ、ポインティングデバイス等の外装部品、特に平板形状以外の形状を有する外装部品に用いる強化ガラスの製造方法として好適である。さらに、本発明の強化ガラスの製造方法は、これらの用途以外にも、高い機械的強度が要求される用途（例えば、窓ガラス、磁気ディスク用基板、フラットパネルディスプレイ用基板、太陽電池の基板およびカバーガラス、固体撮像素子用カバーガラス、食器）の強化ガラスの製造方法としても好適である。 The manufacturing method of the tempered glass of this invention is suitable as a manufacturing method of the tempered glass used for cover glasses, such as a mobile telephone, a digital camera, PDA, a touch panel display. Further, the method for producing tempered glass of the present invention is suitable as a method for producing tempered glass used for exterior parts such as cellular phones, mobile PCs, pointing devices, etc. subjected to heat processing, in particular, exterior parts having a shape other than a flat plate shape. is there. Furthermore, the method for producing tempered glass of the present invention can be applied to applications requiring high mechanical strength in addition to these applications (for example, window glass, magnetic disk substrates, flat panel display substrates, solar cell substrates and It is also suitable as a method for producing tempered glass of a cover glass, a cover glass for a solid-state imaging device, and tableware.
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| CN103097315B (en) * | 2010-09-27 | 2015-10-14 | 旭硝子株式会社 | Chemical enhanced glass, chemically reinforced glass and glass plate for display devices |
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| CN102531384B (en) * | 2010-12-29 | 2019-02-22 | 安瀚视特股份有限公司 | Cover glass and its manufacturing method |
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