TW201213258A - Method for manufacturing non-alkali glass - Google Patents

Abstract

The manufacture method of non-alkali glass of this invention comprises a step of formulating raw materials to a non-alkali glass having a composition of SiO2-Al2O3-B2O3-RO (RO is at least one of MgO, CaO, BaO, SrO, and ZnO), a step of melting glass materials using a melting furnace made of high zirconium refractories, a step of supplying melting glass to molding device using a supply passage made of platinum or platinum alloy, and a step of molding the melting glass supplied to molding device to a specified configuration.

Description

201213258 VI. Description of the Invention: [Technical Field] The present invention relates to a non-inspective glass used for a flat panel display such as a liquid crystal display or an EL display II (electroluminescence display). [Prior Art] In the conventional flat panel display panels such as liquid crystal displays and EL displays, non-authentic glass substrates have been widely used. In particular, electronic devices such as thin film transistor active matrix liquid crystal displays (tft_lcd) are used in car navigation and digital camera finder because of their thinness and low power consumption. In recent years, they have been used in personal computer screens. TV and other uses. The TFT-LCD panel factory is manufactured on a glass substrate (unprocessed board) formed in a glass factory, and after making a plurality of parts, the product is divided and cut into products to form a product, thereby improving productivity and reducing costs. . In recent years, in terms of applications such as TVs and personal computer screens, even larger devices have been required. In order to carry out the multi-layer state of such devices, a large-area glass substrate of 1000 x 1200 mm is required. In addition, the portable device such as a mobile phone or a notebook computer is required to be lightweight, and the glass substrate is required to be lighter in weight. In order to reduce the weight of the glass substrate, it is an effective method for thinning the substrate. Currently, the thickness of the glass substrate for TFT_LCD is about 7 nm. However, the large, thin-walled glass substrate as described above undergoes a large bending due to its own weight of 3 316 263 D01 201213258, which causes a major problem in the manufacturing steps. In other words, the glass substrate is formed into a glass factory and then subjected to steps such as cutting, cooling, inspection, and cleaning. In these steps, the glass substrate will enter and exit the cassette forming the plurality of shelves. The cassette is formed on a frame having two sides on the inner side of the length and the width, or three sides on the inner side of the length, the width, and the height, and is horizontally held in a state in which the glass substrate is placed on both sides or three sides, but the large and thin glass substrate is used. The amount of bending is large, so when the glass substrate is placed on the cassette truss, part of the glass substrate will be damaged by contact with the cassette or other glass substrate' or when the glass substrate is taken out from the frame of the cassette, It is easy to form an unstable state by shaking a lot. In addition, in the display factory, the same problem occurs because the same type of cassette is used. The amount of bending due to the weight of the glass substrate itself is proportional to the glass duty and inversely proportional to the elastic modulus (Y〇ung, s modulus). Therefore, it is possible to reduce the amount of bending of the glass substrate. Therefore, it is necessary to increase the specific elastic modulus represented by the elastic coefficient/density ratio. In order to improve the specific elastic coefficient, it is necessary to become a glass material with a high modulus of elasticity and a low density. However, even if the glass has a lower specific modulus and a lower density, the reduced weight of the glass can increase the thickness of the same weight glass. . Since the amount of glass is inversely proportional to the square of the thickness, the effect of reducing the thickness is greatly reduced. Since lowering the density of the glass is also very effective in achieving weight reduction of the glass, it is preferable to minimize the density of the glass. In general, a relatively large amount of an alkaline earth metal oxide is contained in such an alkali-free glass. In order to reduce the density of the alkali glass, it is effective to reduce the content of the alkaline earth metal oxide 4 316263D01 201213258. However, since the alkaline earth metal oxide promotes the meltability of the glass, the meltability is lowered when the content is lowered. When the meltability of the glass is lowered, internal defects such as bubbles and impurities are more likely to occur in the glass. Since bubbles and impurities in the glass impede the penetration of light, it is a fatal defect of the glass substrate for a display, and it is necessary to melt the glass at a high temperature for a long time to suppress such internal defects. On the other hand, melting at high temperatures will increase the burden on the glass melting kiln. The higher the temperature, the more refractory the refractory used in the kiln is, resulting in a shortened kiln life cycle. Further, thermal shock resistance is also an important requirement for such a glass substrate. Even if the end surface of the glass substrate is subjected to the truncation treatment, there are fine flaws or cracks. When the tensile stress is concentrated on the scratches or cracks due to heat, the glass substrate may occasionally crack. The breakage of the glass not only lowers the operation rate of the production line, but also causes the fine glass powder generated at the time of damage to adhere to the glass substrate, which may cause a disconnection or the like. The processing of the & ® case is not only the recent development direction of TFT-LCD, but also the high-definition, high-speed change, such as high-definition and high-speed change. The development of performance direction, especially in recent years, 乂-^ α λλ in the high-temperature moonlight and light Donghua of the night crystal display, is enthusiastically developing the multi-facestone TFT-LCD (P-Si · TFT- The direction of the LCD is advanced from the p-Si · TFT-LCD because the temperature of the manufacturing step is as high as 0 or higher, so only the quartz glass substrate can be used. However, in the development situation of Zhaozhaowei, although the manufacturing process temperature has been reduced to 400 to 600, it is like the amorphous 矽 TFT-LCD (a-Si TFT-LCD produced by 316263D01 5 201213258). ), still using an alkali-free glass substrate. The manufacturing steps of p-Si·TFT-LCD are more than the manufacturing steps of a-Si·TFT-LCD, because the glass substrate repeats rapid heating and rapid cooling, so the thermal shock to the glass substrate is more serious. Further, as described above, the glass substrate is increased in size, and not only the glass substrate is likely to have a temperature difference, but also the probability of occurrence of minute scratches and cracks at the end faces is improved. Therefore, the probability of damage of the substrate during the thermal process is increased. The most fundamental and effective way to solve this problem is to reduce the thermal stress caused by the difference in thermal expansion, thus requiring a glass with a lower coefficient of thermal expansion. In addition, when the difference in thermal expansion between the material and the thin film transistor (TFT) material becomes large, since the glass substrate is warped, it is required to have a thermal expansion coefficient with a TFT material such as p-Si (about 30 to 33 x 1 (T7/). °C) The similar thermal expansion coefficient. Furthermore, the manufacturing step temperature of the p_Si_TFT-LCD has been lowered recently, but it is still high compared with the manufacturing step temperature of the a-Si TFT-LCD. When the properties are low, in the p-Si·TFT-LCD manufacturing step, when the glass substrate is at a high temperature of 400 to 600 ° C, a shrinkage of a so-called heat shrinkage of a small size is caused, which causes a pixel pitch of the TFT. If the heat resistance of the glass substrate is lower, the glass substrate may be deformed or warped. In addition, in the liquid crystal manufacturing step such as film formation, in order to prevent the glass from being damaged When the substrate is caused to be shifted due to heat shrinkage, a glass having excellent heat quality is required. Further, on the surface of the glass substrate for TFT-LCD, a transparent conductive 6 316263D01 201213258 film or insulating film is formed. A semiconductor film, a metal film, or the like, and various circuits or patterns are formed by photolithography (photolithography). Further, in the film formation and the etching process, various heat treatments and drug treatments are performed on the glass substrate. When an alkali metal oxide (Na 2 〇, K 2 〇, LizO) is contained in the glass substrate, alkali ions are diffused into the formed semiconductor material during the heat treatment, and it is judged that the film characteristics are deteriorated, so that substantially no An alkali metal oxide, or a drug that does not cause deterioration due to various acids, tests, and the like used in the optical remnant step. Further, the glass substrate for TFT-LCD is mainly used by downdraw (downdraw) The process is formed by a floating process. Examples of the down-draw method are a slot downdraw process, an overflow downdraw process, and the like, and a glass substrate formed by a down-draw method. There is no need for grinding processing, and therefore, there is an advantage that it is easy to achieve cost reduction. However, when the glass substrate is formed by the down-draw method, the glass substrate is more likely to be devitrified ( Devitrification), therefore, also requires glass with excellent resistance to devitrification. Therefore, there are proposals to satisfy the above characteristics, especially for non-inspective glass for substrates characterized by low density, low visibility, and south strain point. The alkali-free glass disclosed in Japanese Laid-Open Patent Publication No. 2002-308643, the melting temperature of which is equivalent to a temperature of 1〇2·5 poise (p〇ise). Above about 1580 ° C, high temperature melting is required, and the average thermal expansion coefficient in the temperature range of 30 to 380 C below the density of 2 45 g/cm 3 is 25 to 36 x 1 (T7 / ° C, strain point is above 64 ° C) , is satisfied with the above requirements. 7 316263D01 201213258 However, if such low-density, low-swelling, and strain-free, alkali-free glass is produced on an industrial scale, devitrification may occur during molding due to slight variations in manufacturing conditions. DISCLOSURE OF THE INVENTION An object of the present invention is to provide a method for producing an amorphous glass which can be molded without causing devitrification of the glass, and an alkali-free glass obtained by the method, even if it is produced on an industrial scale. When producing an alkali-free glass that requires high-temperature melting on an industrial scale, it is considered that a high-zirconium refractory excellent in corrosion resistance is used to constitute a molten kiln or downstream thereof from the viewpoint of long life of the manufacturing equipment. Various equipment (such as: clarification tank, adjustment tank, etc.). However, according to the study by the inventors of the present invention, it has been found that when the non-alkali glass disclosed in the above-mentioned Japanese Patent Laid-Open Publication No. 2002-308643 is smelted by the use of a high zirconium refractory manufacturing apparatus, The Zr〇2 component is prepared from the refractory, and the concentration of Zr〇2 in the glass is increased, which is extremely likely to be devitrified. The method for producing the alkali-free glass of the present invention comprises: preparing the raw material to have a mass percentage of Si〇2: 5〇 to 7〇%, Ah〇3:1〇 to 25%, and B2〇3:8. 4 Up to 20%, Mg0: 〇 to 1〇%, Ca0: 3 to 15%, Ba〇: 〇 to 〇. 1/〇, Sr〇: 〇 to 1〇%, Zn〇: 〇 to 1〇%, Ti〇 2: 〇 to 5%, p2〇5: 〇 to 5/» composition, density below 2.45g/cm3, temperature range of .30 to 380 °C = average thermal expansion coefficient within 25 to 36xl (m: Non-experimental glass and in the use of high-cone refractory melt-smoke, the glass raw material is smelted for the use of at least part of the w-road formed by the # alloy to supply the molten glass to the forming device a supply step; and 316263D01 8 201213258 a molding step of molding the molten glass supplied to the molding apparatus into a predetermined shape. Also, in the present invention, the cullet is also included in the glass raw material. Further, in the present invention, "no alkalinity" "The alkali metal oxide (Li2〇, Na20, K20) is 0.2% by mass or less. As in the production method according to the present invention, the melting kiln has a high corrosion resistance. The refractory material can perform stable operation for a long time even when the alkali-free glass which has to be subjected to high-temperature melting is dissolved. Further, the molten glass which is sent from the smelting kiln is supplied to the supply passage of the molding apparatus. At least a part of the platinum or platinum alloy is used to reduce the glass contamination caused by the melting of Zr〇2, so that it can be formed into glass without devitrification. If the electrode is strictly fused, or raw material impurities, or When the glass contains Snn2 as a π agent, the devitrification can be further improved. If the amount of water in the glass is increased, the viscosity of the glass can be lowered. Therefore, it is particularly advantageous for the melting of the glass at the time of manufacture. The non-alkaline glass refers to the case of an amorphous glass which reduces the devitrification due to the reduction of the alkaline earth component and has a low degree of enthalpy and a low expansion. Further, the alkali-free glass of the present invention is low in density. Low expansion and high strain point', and the amount of heat shrinkage and bending are small, the thermal shock resistance is excellent, and the warpage phenomenon is less likely to occur. At the same time, it is not easy to devitrify even if it is produced on an industrial scale. It is quite suitable for glass for substrate of liquid crystal display and EL display. [Embodiment] The glass system obtained by the method of the present invention has

Si〇2-Al2〇3_B2〇3_R〇(R〇 is MgO, CaO, BaO, SrO, and

An alkali-free glass having a composition of one or more kinds of ZnO. Among them, 9 316263D01 201213258 is especially suitable for the manufacture of glass with low density, low expansion and high strain point which must be melted at high temperature. Further, the glass system contains Z r 〇 2 in an amount of 〇 6 % or less, preferably 0.5% or less, more preferably 〇 3% or less, more preferably 〇 2% or less, particularly in terms of a mass percentage. It is most preferably 〇.1% or less, and is preferably 0.02% or more, particularly preferably 0.02% or more. If the Zr〇2 content exceeds 〇 6% or more, it is easily devitrified. From the viewpoint of improving the devitrification, the less Zr〇2 is, the better. This trend is more pronounced when forming a glass that is closer to a low density, low expansion, high strain point. However, even if Zr〇2 is added in a small amount, it has an effect of improving the chemical durability of the alkali-free glass, so it is preferable to contain the compound. Further, it is possible to completely prevent the Zr〇2 from being mixed into the glass raw material with impurities, which will lead to the improvement of the raw material cost. Moreover, it is also possible to mix Zr〇2 from cullet (for example, when glass made of sorghum refractory is used as cullet, the possibility of containing Zr〇2 in cullet is extremely high). In addition, cullet is less susceptible to melting, such as alkali-free glass, and is a suitable material for glass. Moreover, from the viewpoint of the current high environmental awareness, the necessity of recycling and recycling using broken glass as a raw material has gradually increased. From this point of view, in the present invention, it is preferable to set the lower limit of Zr 〇 2 to 0.01%. By containing &〇2 at Ο·〇1°/〇 or more, especially 0.02% or more, it is expected that the chemical durability of the glass will be improved. In addition, there is no need to use a high-purity raw material for Zr〇2, so that an increase in raw material cost can be avoided. It is possible to use broken glass. Further, the content of the glass-based Sn〇2 is preferably 〇3〇/〇 or less, particularly preferably 0.28% or less, and more preferably 〇〇〇5% or more, particularly 316263D01 10 201213258 at 0.02%. Above, it is more preferable to use 3% or more. In the present invention, although Sn02 is not an essential component, it is a component which can be added as a clarifying agent. Further, when the glass is electrically melted by the Sn 〇 2 electrode, Sn02 which is an electrode component is melted from the glass. The sn〇2 content is closely related to the devitrification of the glass caused by Zr02. If the amount of Sn02 is too large, it is easy to devitrify. Further, as in the case of Zr 〇 2, from the viewpoint of improving the devitrification property, the Sn02 is as small as possible. However, 'Sn02 is one of the few components that can exert a clarifying effect in a high temperature region, and a higher clarification effect can be expected with a small amount. Therefore, in the glass of the present invention which is required to be melted at a high temperature and which is difficult to clarify, in order to improve the clarification property and reduce the amount of As203 used, Sn02 is preferably contained in an amount of 0.005% or more, particularly preferably 0.01% or more. In addition, the clarifying effect of Sn02 is that even the Sn02 melted from the electrode can exert the same effect. Specific examples of the preferred glass obtained by the production method of the present invention include, for example, a density of 2.55 g/cm 3 or less (preferably 2.4 μ; g/cm 3 or less, more preferably 2.42 g/cm 3 or less). , the average coefficient of thermal expansion in the temperature range of 30 to 380 ° C is 25 to 4 〇 xl (T7 / ° C (preferably 25 to 36xl (T7 / ° C, especially 28 to 35xl0_7 / ° C is better), A glass having a strain point of 640 ° C or higher (preferably 650 ° C or higher). Glass having such characteristics generally has to be melted at a high temperature, but has excellent thermal shock resistance, and is not caused by the thermal expansion coefficient of the TFT material. The curvature phenomenon can be lightened, and the bending amount can be reduced, and the heat shrinkage is small. For example, the Si〇2-Al203-B203-RO glass mentioned above generally corresponds to a temperature of W2·5 poise at 1580°C or higher. It is necessary to carry out high-temperature melting. Such 11 316263D01 201213258 must be melted at a high temperature, and the viscosity is improved even if the viscosity is slightly lowered. In terms of lowering the viscosity of the high temperature, it is an effective method to increase the moisture of the glass. In the substrate glass of the present invention, the amount of water of the glass depends on /3 - The OH value means 'preferably adjusted to be 〇2/mm or more, preferably 〇25/guagua or more' to be more preferably 〇3/mm or more, and more preferably 〇4/mm or more. From the viewpoint of improvement in meltability, the higher the value of _〇H, the better, but the higher the tendency to lower the strain point. From this point of view, the upper limit of the value is preferably 〇.65/mm or less. Especially in 〇, 6/mm or less is preferable. In addition, the _〇H value of the glass is in the infrared absorbing light of the glass, and the β β -OH value is determined according to the following formula: ^l/xyogiOd/Tz) X: Glass Thickness (mm) Τι: light transmittance in the reference wavelength 3846cm_1 (%) D. 2. Minimum light transmittance (%) near the base absorption wavelength of 3600cm 1 Furthermore, in addition to the above characteristics, the liquid phase temperature is the best At 115 〇 <3 (: or less (especially 113 (TC or less is preferable, especially 11 〇〇. (hereinafter, more preferably), the viscosity in the liquidus temperature is preferably 105.4 dPa · s or more (especially LoWdPa · s or more is preferable. By satisfying this condition, even if it is formed into a plate shape by the lower drawing method, devitrification does not occur, the polishing step can be omitted, and the production cost can be reduced. In a 10% HCl aqueous solution, when the treatment was carried out under the conditions of 8 (TC-24 hours, the amount of erosion was below 1 〇 #m, and in a 1% HCl aqueous solution, the treatment was carried out under conditions of 80 ° C - 1 hour. When the surface was visually observed, no white turbidity and roughness were observed, and when the treatment was carried out in a 130 BHF solution at a temperature of 20 ° C for 30 minutes, the amount of erosion was 〇m at 12 316 263 D01 201213258 'and when at 63 BHF When the solution was used in the solution of 2 (rc_3 〇 minutes), no turbidity or roughness was observed on the surface by visual observation, and a favorable condition was exhibited. Further, the specific elastic modulus is preferably 27.5 GPa/g·cm·3 or more (especially preferably 29_0GPa s or more). By satisfying this condition, the amount of bending of the glass substrate can be reduced. If the glass melt temperature in the viscosity of 102.5 dPa · s is below 1650 ° C, the meltability will be better. Further, a preferred glass composition exemplified by the production method of the present invention can be exemplified by, for example, a mass ratio of si〇2:5〇 to 7〇0/〇,

Al2〇3:10 to 25%, B2〇3:8.4 to 20%, MgO:0 to 10%, CaO:3 to 15%, BaO:0 to 10%, SrO:0 to ι〇〇/0, ZnO : 0 to 10%, Τι〇2: 〇 to 5%, P2 〇 5: 〇 to 5% glass. A glass having such a composition generally has to be subjected to high-temperature melting, but the strain point, density, thermal expansion coefficient, chemical resistance, specific modulus of elasticity, meltability, moldability, and the like which are required for use as a substrate such as a liquid crystal display can be obtained as described above. characteristic. The reasons for limiting the composition range are explained below.

The Si〇2 content is 50 to 70%. If it is less than 5% by weight, the chemical resistance, in particular, the acid resistance will be deteriorated, and it is difficult to achieve a low density. On the other hand, when it is more than 70%, the high-temperature viscosity is increased and the meltability is deteriorated, and at the same time, defects of devitrified foreign matter (white smectite) are easily generated in the glass. The content of Si〇2 is preferably 58 〇/〇 or more, particularly preferably 60% or more, more preferably 62% or more, and most preferably 68% or less, and particularly preferably 66% or less.

The Al2〇3 content is from 1〇 to 25%. If it is less than 1〇%, it is quite difficult to reach the strain point above 640°C. Also, Al2〇3 has the effect of increasing the glass elastic modulus and increasing the specific elastic modulus. If it is less than 1〇%, the elastic coefficient is 316263D01. 13 201213258 Lower. The content of Al2〇3 is preferably at least 12%, more preferably 145% or more, and most preferably 19% or less, particularly preferably 18.7% or less. Further, when it is more than 19%, the liquidus temperature rises and the devitrification resistance decreases. ΒΖ〇3 has the function of a flux, which is a tool for reducing the viscosity and improving the meltability. However, although the glass substrate used in the liquid crystal display requires high acid resistance, if the hydrazine is more resistant to acidity, The tendency to decrease. The B2〇3 content is 8.4 to 20%. If it is less than 8.4%, the role as a flux will be insufficient, and the buffer-resistant hydrofluoric acid will deteriorate. On the other hand, if it is more than this, the strain point of the glass is lowered, the heat resistance is lowered, and the acid resistance is deteriorated. In particular, since the modulus of elasticity is lowered, the specific modulus of elasticity is also lowered. ^b2〇3 contains 1 is preferably 8.6% or more, and preferably 15% or less, especially 14. Below /0 is better, and 12% or less is preferred.

The MgO content is 〇 to 1% by weight. Mg〇 does not cause the strain point to decrease, but lowers the high temperature viscosity and improves the glass meltability. And in alkaline earth metal oxides, the effect of reducing density is the most. However, when a large amount is contained, the liquidus temperature rises and the devitrification resistance decreases. Moreover, since Mg 〇 will react with buffered hydrofluoric acid to form a product 'fixed on the element on the surface of the glass substrate, or attached to the glass substrate, but this situation may cause white turbidity, so the content thereof There are restrictions. Therefore, the content of Mg〇 is preferably from 〇 to 2%, particularly preferably from 1% to 5%, more preferably from 〇 to 5%, particularly in the case of non-containing ones.

CaO is also like MgO, which is a component that does not lower the strain point, but reduces the viscosity to the temperature and significantly improves the glass meltability, and its content is 3 to 15%. Such an amorphous glass substrate is generally important in order to increase the solubility of the glass substrate which is difficult to melt and which is less expensive than 14 316263D01 201213258. Reducing si〇2 in the glass composition system of the present invention is the most effective method for improving the smelting property. However, if the amount of Si〇2 is decreased, the acid resistance will be extremely lowered' and the density and thermal expansion coefficient of the glass are increased. So it is best to avoid it. Therefore, in the present invention, in order to improve the meltability of the glass, CaO is contained in an amount of 3% or more. On the other hand, if the CaO is more than 15%, the resistance of the glass to the buffered hydrofluoric acid deteriorates. 'The surface of the glass substrate is more susceptible to intrusion' and the reaction product is attached to the surface of the glass substrate to make the glass white and cloudy, and because of the coefficient of thermal expansion. Become too high and therefore best avoided. The CaO content is preferably 4°/❶ or more, more preferably 5% or more, more preferably 6% or more, and most preferably 12% or less, particularly preferably 1% or less, and 9% or less. For better. B aO is a component that enhances the durability and devitrification of glass, and contains 0 to 10%. However, it is a component that greatly increases the density of glass and the coefficient of thermal expansion. When low density and low expansion, it is best not to include it. Moreover, from the point of view of the environment, it is best not to contain too much. The Ba content is preferably 5% or less, and particularly preferably 2% or less. However, in order to reduce the density and the low expansion of the glass, it is preferably 1% or less, more preferably 〇 1% or less.

Sr〇 is a component that enhances glass resistance and devitrification resistance and contains 0 to 10%. However, if too much is contained, the density and thermal expansion coefficient of the glass will increase. The SrO content is preferably 4% or less, particularly 2.7% or less, more preferably 1.5% or less. Further, 'BaO and SrO are components which have a property of improving the resistance to buffer hydrofluoric acid 15 316263D01 201213258 (BHF resistance). Therefore, in order to improve the bhF resistance, the total amount of the components is preferably 0.1% or more (especially preferably 0.3% or more, and more preferably 0.5% or more). However, as described above, when too much BaO and SrO are contained, the total amount of the glass is preferably suppressed to 6% or less because of the increase in the density and thermal expansion coefficient of the glass. In this range, the total amount of BaO and SrO is preferably as large as possible from the viewpoint of improving BHF and resistance to devitrification, and vice versa, from the viewpoint of density or coefficient of thermal expansion, or environmental concerns. In terms of content, it is best to reduce the content as much as possible.

ZnO is a component which improves the buffer-resistant hydrofluoric acidity of the glass substrate and improves the meltability. When the content is too large, the glass is easily devitrified, and the strain point is lowered and the density is increased, so that it is preferably avoided. Therefore, the content thereof is 0 to 10%, preferably 0 to 7%, particularly preferably 5% or less, more preferably 3 Å/〇 or less, particularly preferably 0.9% or less, and most preferably 0.5%. the following. Each component containing MgO, CaO, BaO, SrO, and ZnO is formed by mixing, and the liquidus temperature of the glass is remarkably lowered, and the melting property and moldability of the glass are improved by making it difficult to crystallize foreign matter in the glass. effect. However, when the total amount of each of the above components is too small, the effect of the flux is deteriorated, and the thermal expansion coefficient is too low to reduce the integrable property with the TFT material. On the other hand, if it is too large, the density is increased, and the glass substrate is not reduced in weight, and the specific modulus is lowered, so that it is preferably avoided. The total amount of the components is preferably from 6 to 2% by weight, preferably from 6 to 15%, particularly preferably from 6 to 12%.

Ti〇2 is an improvement of the resistance of glass, especially to improve the acid resistance, and to make the ifj temperature viscosity and improve the melting property, but if the content is too much 316263D01 16 201213258, the glass will be colored, and Reduce the light transmission, so it does not. Suitable for glass substrates for displays. Therefore, Ti〇2 should be limited to 5% ‘, preferably 0 to 3%, especially 〇 to 1%. P2〇5 is a component that enhances the devitrification resistance of glass. However, if the content is too large, it is best avoided because it causes phase separation and opalescence in the glass and the acid resistance is also significantly deteriorated. and so,! >2〇5 should be limited to 〇, preferably 0 to 3%, and % is preferably 〇 to 1〇/〇. Further, in addition to the above components, in the present invention, γ 〇 Nb 〇〇 τ 3 may be contained, and the total amount of La 2 〇 3 may be within about 5%. Although these components have the functions of raising the point and the flatness coefficient, if the content is too large, it is preferable to avoid the density of the force D, ΓΏ '. Further, the clarifying agent such as metal powder such as As2〇3, Sb203, Sb205, F2, Cl2, S03, C, or S1 may be contained before the glass characteristics are not impaired, and the total amount is within 5%. It may also contain a clarifying agent such as Ce〇2, Fe203, etc. within 5°/〇. In addition, As2〇3 is broken from the environmental point of view, it is best not to use. Next, the manufacturing method of the non-inspective glass of the present invention will be described in detail. The method of the present invention comprises a compounding step, a melting step, a supplying step, and a forming step. , the mixing step is a batch preparation to prepare the glass raw material to have a composition of S1〇2, Al2〇3-B2〇3-R〇 (R〇MgO, CaO, BaO, SrO, and: one or more) The steps of the glass. In particular, as described above, it is preferably formulated to have a density of 2.55 g/cm3 or less and 30 to 380. (: temperature range: the average thermal expansion coefficient in the circumference is 25 to 40><1〇-7/. (:, the characteristic of the strain point at 640, and in terms of mass percentage, contains si〇2:5〇 17 316263D01 201213258 to 70%, Al2〇3: l〇 to 25%, B203: 8.4 to 20%, MgO: 0 to 10%, CaO: 3 to 15%, Ba〇: 〇 to 1〇%, SrO: 0 Up to 10%, ZnO: 0 to 10%, TiO2: 0 to 5%, ?2〇5: 〇 to 5% glass. Furthermore, the Zr〇2 component causing devitrification causes fear of subsequent 'melting In the step, the content is increased from the melting of the fossils. It is important that the Zr02 component is prevented from being mixed into the glass raw material as much as possible, and even if it is used in an attempt to improve chemical durability, the amount of addition is still It must be kept at the minimum limit. If the Sn02 component that strengthens the devitrification of Zr02 is electrically melted by the Sn02 electrode, it will increase the content due to the melting from the electrode. Therefore, it is important to limit the amount of glass from the raw material. When Sn02 is mixed in, and 'deliberately used for clarification, etc., the amount of addition must remain at the minimum limit. The step is a step of melting the raw material by a melting kiln using a high lanthanum refractory. The high-cone refractory is preferably a Zr02 f-bonded refractory which is excellent in corrosion resistance and can be used for a long period of time. The composition of the non-alkaline glass raft is about 15 〇〇 to 165 〇ΐ. Further, by using Sn 〇, 番 Ώ amp & upper electrode, pt electrode, Μ〇 electrode, etc., electric heating is performed. Electrical melting, # can be easily carried out at high temperature. In the case of course, it is of course possible to combine the use of the tongue, the upper +h heavy oil or the burning of the rolled body to perform the melting. In addition, the 'electrode type is as follows, 乂, 乂, , and special restrictions, only consider the factors such as the degree of erosion of the electrode life, and then determine the appropriate type. In addition, the electrode used is not necessarily only one type, but also the soil and the ^ can be considered After various conditions, the group uses two or more kinds of electrodes. For example, when Dan Xuan is secreted in the glass, it is used in the part where the electrode component is easy to appear.

Sn〇2 electrode or 1N 316263D01 18 201213258 =Pt electrode is used in other parts of Fen. In particular, the post electrode is composed of a male oxide, and therefore, even if the electrode component is dissolved in the glass, it is difficult to adversely affect the glass. (4) The step of supplying the molten smelting in the molten nest to at least a portion of the passage formed by the turning or the first alloy is supplied to the forming step. The reason for using m to form a supply passage from the alloy is to prevent further melting into the glass. In addition, the addition of 2 does not affect the devitrification of the glass, and also affects the uniformity. In the case of breakage which can be used even in the case of easy-to-use red grinding, it is necessary to improve the homogeneity of the glass, and it is therefore necessary to prevent the occurrence of glass contamination due to (10) melting in the supply passage. The secret private alloy keeps the secret of supply and has an effect on the homogeneity of the glass. Therefore, the more the core formed by the shell or the surface alloy, the better, and the ideal situation is that the contact surface with the glass is formed by the turn or age. In addition, the so-called "supply channel" refers to the Wei position set between the bright and the smoked and the (four). These include clarification tanks, adjustment tanks, slabs, and joints that connect the tanks. In addition, it is better to clarify and homogenize the glass in the supply of the food.

In addition, the term "supply passage formed by the use of inscriptions or alloys" means that not only the supply passage of (4) or the alloy is covered with the refractory (four) surface. The MB plastic forming step is a step of molding the molten glass supplied to the molding apparatus into a predetermined shape. In terms of display use, the glass can be subjected to overflow down-draw method, slot d〇wn draw pr〇(10)s, floating method 316263D01 19 201213258 (floating method), roll out method, etc. The method is formed into a thin plate shape. In particular, when molding is carried out by the overflow down-draw method, a glass plate excellent in surface quality can be obtained without polishing, which is preferable. According to the above, the alkali-free glass of the present invention can be obtained. Further, in the production method of the present invention, the Zr〇2 tolerance amount should be limited to the content of the obtained glass in terms of mass percentage, below 0.6%, preferably from the viewpoint of preventing devitrification in the molding step. 〇 5% or less, particularly preferably 0.3% or less, more preferably 0.2% or less, and most preferably 〇 1% or less. Further, it is preferably 0.01% or more, and particularly preferably 〇.〇2〇/0 or more. When the Zr 〇 2 content in the obtained glass is 0.6% or less, the devitrification property can be improved. In addition, the amount of Zr〇2 in the glass can be used according to 21 of the compounding step, 原料2 raw material usage or impurity management, refractory temperature management or current amount adjustment in the melting step, and use of platinum or platinum alloy in the supply step. Adjustments such as area and other factors. Further, in the same manner, the Sn 〇 2 tolerance is preferably in the range of 1% by mass of the obtained glass, preferably 0.3% or less, particularly preferably 〇 28% or less, and preferably at G. (K) 5%. Above, especially above _% is preferred. When Sn 〇 2 in the obtained glass contains 1 or less, 3% or less, the devitrification caused by Zr 〇 2 can be greatly suppressed. Further, the amount of Sn 〇 2 in the glass can be adjusted depending on factors such as the amount of Sn 〇 2 raw material used in the compounding step or the management of impurities, the number of electrodes used in the melting step, or the temperature management of the electrodes. Further, in the case where the glass is made low-viscosity and the meltability is improved as much as possible, it is preferable to increase the moisture content of the glass. Specifically, according to the -OH value, it is better to adjust it to 0.2/mm or more, especially 〇25/mm or more, and 316263D01 20 201213258 is more (U/mm or more is the water content of the glass. More than mm is better. In the adjustment of the raw material), in the raw material, j is used to select the raw material with a higher water content (for example, the component with a reduced amount of hydroxy group), and the water in the glass is limited, such as gas, ^ ^ φ , In the case where the glass is melted, oxygen combustion is used to increase the amount of the material in the furnace, and the direct remaining water is guided by a method such as water vapor bubbles in the molten glass. (Example 1) Tables 1 and 2 An experimental result indicating the influence of the Sn 〇 2 content on the devitrification phenomenon caused by Zr 〇 2. The glass 1 is based on % by mass, and contains: SiO 2 : 60% > Al 2 〇 3: 15% - Β 2 〇 3: 10 ο / 0 ' CaO:; 5% ' BaO: 5 ° / 〇 ' SrO: 5%, and the thermal expansion coefficient of 37xl0_7 / ° C in the density of 2.5g / cm3, 30 to 380 ° C:, the strain point is 655 ° C Glass. Glass 2 is based on % by mass: SiO2: 64%, Al203: 16%, B2〇3: 11%, CaO: 8%, SrO: 1% ' at a density of 2.4 g/cm3, 30 to 380 Thermal expansion coefficient in °C 32x10_7/ °C Glass with strain point at 660 ° C. Table 1 Glass 1 SnO, content (% by mass) 0.0 0.2 Zr02 Content (% by mass) 0.0 - 0.1 _ - 0.2 - 0.3 - - 0.4 0.5 _ - 0.6 $1000 0.7 1100 0.8 1138 - 0.9 >1180 - 21 316263D01 201213258 Table 2 Glass 2 Sn02 content (% by mass) 0.0 0.2 Zr02 Content (% by mass) 0.0 - 0.1 - 0.2 - ^ 1000 0.3 ^ 1000 ^ 1000 0.4 1100 1107 0.5 1108 1112 0.6 1158 1160 0.7 1182 1186 0.8 > 1190 - 0.9 - - Each sample was prepared as follows. First, the glass raw material was prepared so that the amount of Zr02 and the amount of Sn02 were changed to the above composition. The raw material was batch-packed into a platinum crucible, Molding was carried out after melting for 24 hours at 1600 ° C. Then, the obtained glass was pulverized and passed through a standard sieve 30 mesh (500 # m) to remove the glass powder remaining in 50 mesh (3 〇〇 ym). Load into the original boat and remove it in a temperature-gradient furnace for 24 hours. For the obtained sample, the maximum temperature exhibited by the crystal of Zr02·SiO 2 in the glass was observed by a microscope. In addition, the "-" part in the table refers to the uninvestigated person. From the above results, it is known that the glass 2 which is reduced in density, low expansion, and high strain point by reducing the soil component such as BaO is more likely to be devitrified by a small amount of Zr 〇 2 . Moreover, it is confirmed that the higher the content of Zr〇2 and the content of Sn〇2, the more the 316263D01 22 201213258 is more permeable. (Embodiment 2) Next, with respect to the actual state of the present invention, the root_indicates; Fig. 1 is a schematic view showing the structure of a glass made by the method for producing the present invention. First, the construction of the glass manufacturing equipment will be described. The glass manufacturing " is further provided with: a silvery-shaped smelting banana 2 constituting a molten glass supply source, a clarification tank 3 disposed at a downstream end of the melting kiln 2, and an adjustment tank 4 disposed at a downstream end of the clarification tank 3. And the molding device 5 provided at the downstream end of the adjustment tank 4; and the melting kiln 2, the clarification tank 3, the adjustment tank 4, and the molding apparatus 5 are connected by the contact flow paths 6, 7, and 8. The melting kiln 2 has a bottom wall, a side sill, and a top wall. The walls are formed of a sorghum refractory such as a Zr Ο 2 electroformed refractory. The side wall system is designed to have a thin wall thickness to make the refractory easy to cool. Further, a plurality of pairs of electrodes are disposed on the lower end and the bottom wall of the side walls on the left and right sides, and a plurality of burners are respectively disposed at the upper ends of the side walls on the left and right sides. A cooling device is provided in each of the electrodes so that the temperature of the electrodes does not rise excessively. Further, when the burner is subjected to oxy-combustion heating using an oxygen burner, higher temperature heating can be performed and the moisture of the glass can be easily increased. Then, by applying electric power between the electrodes, the glass can be directly energized and heated. Further, by radiating the flame of the burner toward the upper end space of the molten glass, it is possible to heat and melt the soil from above. An outflow enthalpy is formed on the side wall of the downstream end of the melting kiln 2, and the 兮, 宁 outlet passes through the narrow collateral flow path 6 provided at the upstream end, and communicates with the smelting/fuming 2 and the clarifying tank 3. 316263D01 23 201213258 The above clarification tank 3 has a bottom wall, a side wall, and a top wall, and these are formed of a high (four) refractory. x, the above-mentioned contact flow path is a bottom wall, a side wall, and a top wall, and these wall systems are formed by an ancient knot system such as *Zr〇2 electric scale refractory. The clarification tank 3 has a small volume and melts the smoke on the inner wall surface of the bottom wall and the side wall (at least in contact with the inner wall surface of the smelting glass), and the lap shaft alloy is adhered to the venting flow path 6 and the side wall. Platinum or platinum alloy is also adhered to the inner wall surface. This clarification is provided on the side of the upstream end m downstream of the above-mentioned contact flow path 6. The clarification tank 3 is mainly used for the clarification of the glass, and the fine bubbles in (4) will be removed from the glass by the clarification of the clarification shot. The mantle forms an outflow port on the downstream end side wall of the clarification tank 3, and the outlet port has a narrow contact flow path 7 at the upstream end, and communicates with the adjustment groove 4 at the downstream end of the stalking machine. The adjustment groove 4 has a bottom wall, a side wall, and a top wall formed of a high-stagger refractory. And the above-mentioned contact flow path & wall bottom wall, side wall, and top wall, these walls are also formed by Zr02 electroforming//, high lanthanide refractory. The bottom wall of the adjusting groove 4 and the side wall 2 are at the same surface (at least in contact with the inner wall surface portion of the glazed glass), and the inner wall is Q gold, and the bottom wall and the side wall of the connecting flow path 7 or the molybdenum is attached to the platinum.痞钿人,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, The downstream end of the contact flow is connected to the forming device 5. 8. In the adjustment of the groove forming device 5, the plate glass forming device used in the stencil type such as the liquid crystal panel glass, for example, the overflow center = glass = the bottom wall of the connecting flow path 8 and the inner wall surface of the (four), Feeding the alloy. Further, in the present embodiment, the "supply flow path" means from the contact flow path 6 provided downstream of the melting cold to the contact flow path 8 provided at the upstream end of the molding apparatus. Further, although the glass manufacturing equipment including the melting kiln, the clarification tank, the adjusting tank, and the plastic forming apparatus has been exemplified as described above, for example, it is also possible to provide homogenization of the glass stirring between the adjusting tank and the molding apparatus. Stirring tank. Further, each of the above-described apparatuses is exemplified by the case where the platinum or the initial alloy is attached to the refractory, but it is of course possible to use a device composed of the original or the alloy itself. A method of manufacturing a glass using a glass manufacturing apparatus having the above configuration will be described. First, the glass raw material is blended into a glass having a composition of Si〇2-Al203-B2〇3-RO (one or more of RO-based MgO, CaO, BaO, SrO, and ZnO). Specifically, the glass raw material is formulated to contain SiO2: 50 to 70%, A12 〇 3:1 〇 to 25%, Β2 〇 3:8·4 to 20%, MgO: 0 to 10%, CaO. : 3 to 15%, Ba〇: 〇 to 10%, SrO: 0 to 10%, ZnO: 0 to 10%, TiO2: 0 to 5%, p2 〇 5: 0 to 5% glass. Further, in addition to the above components, various components such as a clarifying agent may be added, but it is extremely important to avoid the incorporation of the ZrO 2 or Sn02 component from the glass raw material as much as possible. Moreover, when deliberately using these components, it is necessary to carefully consider the amount of mixing from the manufacturing equipment before the 25 316263D01 201213258 is mixed, and carefully determine the amount of addition. In addition, when it is desired to increase the amount of moisture in the glass, a raw material such as a hydride is used. Next, the prepared glass raw material is put into the melting kiln 2 to be melted and vitrified. A voltage is applied to the electrodes in the melting kiln 2, and the glass is directly energized and heated. Moreover, the glass is heated from above by the combustion flame of the burner. Accordingly, the glass is melted at a high temperature of about 1500 to 165 (when the side wall and the electrode are sufficiently cooled while being melted simultaneously), the melting of Zr〇2 or Sn〇2 can be effectively suppressed. The glass-melted molten glass in the kiln 2 is introduced into the clarification tank 3 through the connection flow path 6. The molten glass contains initial bubbles generated during the vitrification reaction, but in the clarification tank 3, the initial bubble The clarified gas released from the clarifier component is removed by expansion and removal. The clarified molten glass in the clarification tank 3 is introduced into the adjustment tank through the collateral flow path 7. Melting introduced into the adjustment tank 4 The glass is a high temperature 'point low' and cannot be directly molded by the molding device in this state. Here, it is convenient to use the adjustment groove to lower the temperature of the glass and adjust it to a viscosity suitable for molding. The adjustment groove 4 is used to adjust the viscosity. The molten glass is introduced into the overflow lowering device through the connecting flow path 8, and is formed into a thin plate shape, and then cut, end surface processing, etc., thereby obtaining an alkali-free glass. Substrate glass. According to the above method, the glass obtained from the melting kiln will be contacted only with less contaminated platinum or platinum alloy, without being exposed to high zirconium refractories, etc., and supplied to the molding apparatus' so as not to cause excessive Zr〇2 In addition, 316263D01 26 201213258 can also strictly control the content of Sn〇2. Moreover, the moisture can be adjusted. Therefore, the obtained alkali-free glass can form the Zr〇2 content at 〇6/ ° "The content of Sn 〇 2 is 0.3% or less, and the / 3-OH value is in the range of 〇 2 / mm or more, and a glass which is less likely to cause devitrification and is excellent in meltability is formed. (Example 3) ' Next, The glass obtained by the method of the invention is described. First, the glass raw materials such as cerium, alumina, boric acid, calcium carbonate, and nitric acid are blended and mixed according to the mass%: Si〇2: 64%, Al2〇3: The composition of 16%, B2〇3.ll%, CaO: 8%, and SrO: 1%. Further, both the Zr〇2 content and the Sn〇2 content in the above raw materials are 〇〇1% or less. Use bismuth pentoxide converted to L0% according to Sb2〇3. Then 'send glass raw materials to The molten ruthenium consisting of high zirconium refractories is combined with direct electric heating and oxycombustion heating by the 811 〇 2 electrode, and melted at a maximum temperature of 165 Torr. Then, in the clarification tank and the septic tank The molten glass is clarified and homogenized while being adjusted to a viscosity suitable for molding. Then, 'after the brittle glass is supplied to the overflow lowering device and formed into a plate shape, 'the glass sample having a thickness of 7 minutes is obtained by cutting off. The molten glass obtained from the melting kiln is supplied to the forming apparatus while being in contact with only the platinum or the platinum alloy. For the obtained glass sample, the contents of &02 and Sn02, and the /3-oh value of the glass are confirmed. 'At the same time, it is evaluated for the presence or absence of devitrification. The results are shown in Table 3. 27 316263D01 201213258 Table 3 Glass sample content (% by mass) Zr02 0.2 Sn02 0.1 Call-OH 値 (/mm) 450 Devitrification without clarification (pieces/kg) 0.1 Density (g/cm3> 2.4 Thermal expansion coefficient (xlO' 7/°C) 32 Viscosity characteristic strain point 670 Xu cold point 725 104 1325 103 1500 1〇2.5 1605 The Zr02 and Sn02 contents in the glass are confirmed by fluorescent X-ray analysis. The /5 -OH value of the glass is FT -IR (F〇urier transform infrared spectrophotometer) to measure the transmittance of glass, and obtain the following formula: -OH value ^l/xyogiOd/Tz) X: glass thickness (mm) Τι: reference Light transmittance (%) at a wavelength of 3846 CHT1 Τ2: Minimum light transmittance (%) in the vicinity of a hydroxyl absorption wavelength of 3,600 cm·1 Devitrification is obtained by observing the presence or absence of devitrification by a microscopic observation of the obtained substrate glass. 28 316263D01 201213258 The clarification system counts the number of bubbles of 100/im or more in the glass substrate and evaluates it by the number of bubbles converted to an average of 1 kg. Density is measured using the well-known sub-mimimeter method. The coefficient of thermal expansion is measured by a dilatometer to measure the average coefficient of thermal expansion in the temperature range of 30 to 380 °C. The strain point and the cold spot were measured in accordance with the method of ASTM C336-71. The softening point was measured in accordance with the method of ASTM C338-73. Further, each temperature corresponding to the viscosity of 104, 1〇3, and 1〇2·5 was measured by a platinum ball drawing method. The alkali-free glass which can be manufactured according to the method of the present invention is not only suitable for display applications, but also can be used for image sensors such as a charge coupled device (CCD), a double contact solid image sensor (CIS), Glass substrate material for solar cells. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic explanatory view showing a glass manufacturing apparatus used in the production method of the present invention. [Explanation of main component symbols] 1 Glass manufacturing equipment 2 Refining kiln 3 Clarification tank 4 Adjustment tank 5 Molding device 6,7,8 Connection flow path 29 316263D01

Claims (1)

201213258 VII. Patent application scope: 1. A method for manufacturing alkali-free glass, comprising: compounding raw materials into SiO2 with mass percentage: 50 to 70%, Al2〇3: 10 to 25%, B203: 8.4 to 20%, MgO: 0 to 10%, CaO: 3 to 15%, BaO: 0 to 0.1%, SrO: 0 to 10%, ZnO: 0 to 10%, TiO2: 0 to 5%, P2O5: 0 to 5 a composition of %, a density of 2.45 g/cm3 or less, a step of having an average coefficient of thermal expansion of 25 to 36 x 10 _7 / ° C in the temperature range of 30 to 380 ° C; using a melting kiln using a high zirconium refractory a melting step of melting the glass raw material; a supply step of supplying the molten glass to the molding apparatus by using at least a part of a supply passage formed of platinum or a platinum alloy; and molding the molten glass supplied to the molding apparatus into a shape of a predetermined shape step. 1 316263D01