TW201014811A - Glass manufacturing apparatus and method - Google Patents

Abstract

To provide a glass manufacturing apparatus preventing the generation of bubbles during the glass manufacture and preventing the bubbles from remaining in a manufactured glass product, and a glass manufacturing method. The glass manufacturing apparatus has a platinum-made or platinum alloy-made member which comes in contact with molten glass, wherein a layer formed from an alumina-based ceramic particle containing 0.2-5 wt.% Fe expressed in terms of Fe2O3 based on total quantity of the alumina-based ceramic particle and having a changing point where Fe redox (Fe<SP>2+</SP>/Fe<SP>2+</SP>+Fe<SP>3+</SP>) is increased in the molten glass temperature region, is formed on the rear side surface of the surface of the member being in contact with the molten glass.

Description

201014811 IX. Description of the Invention [Technical Field of the Invention] The present invention relates to a glass manufacturing apparatus and a glass manufacturing method. [Prior Art] As a constituent material of a glass manufacturing apparatus (a communication path of a melting tank and a φ φ), platinum, a metal, for example, rhodium (Rh), gold (Au), or a carbon alloy is used (hereinafter, in the present specification, Uranium and). A platinum material which can be used as a constituent material of such a material is a glass which is chemically dissolved in a molten state because it does not form an oxide layer in the atmosphere and is not easily deformed or damaged during the movement. The temperature of the glass manufacturing step is based on the high temperature environment of φ 900 Ό or more. Uranium materials also do not contaminate the interior of the unit to maintain adequate durability in the high temperature environment. However, glass manufacturing equipment using lead materials has problems in the molten glass due to moisture. This is due to the moisture contained in the molten glass and the formation of hydrogen and oxygen. It is considered that although hydrogen passes through the platinum material through the platinum material method and oxygen remaining in the molten glass, bubbles are generated at the interface of the platinum material (the patent uses the glass clearing tank, the stirring tank and the platinum or other precious metal elements of the manufacturing apparatus: (A platinum alloy of ruthenium or rhodium (Ru) is collectively referred to as a platinum material.] The platinum material is not degraded at the melting point, and is excellent in the displacement property of the device, and is not easily contaminated with the treatment content, and is in the above characteristics, even in molten glass. It can be centered for a long period of time, and the platinum material produced at the interface of the platinum material is dissociated and released to the outside during the glass manufacturing process, and the oxygen-free concentration exceeds the solubility limit in the literature 1 to 4 for reference) -5 - 201014811. When the bubbles remain in the glass product to be produced, the quality of the glass product is lowered. In particular, the liquid crystal display (LCD), the organic electroluminescence/display (OLED), the inorganic electroluminescence, the display, etc. are substantially not contained. When the alkali-free glass substrate of the alkali metal oxide is used, the alkali-free glass has a high melting point and is highly viscous compared with the alkali-containing glass, so that bubbles in the molten glass are difficult to float. In order to solve this problem, it is proposed to provide a dense hydrogen-impermeable film on the outer surface of the platinum material (refer to Patent Documents 1 to 4). The material of the dense hydrogen-impermeable film can be exemplified. [Patent Document 1] Japanese Patent Publication No. 2004- 523449 (Patent Document 2) International Publication No. WO2006/030738 (Patent Document 3) International Publication No. WO2005/063634 (Patent Document 4) [Problems to be Solved by the Invention] The hydrogen-impermeable dense film of the prior art proposes a hydrogen-impermeable material by focusing on the molecular diameter or ion diameter of hydrogen. A dense film is applied by coating or the like, and the film is prevented from being released to the outside by the film. However, when the glass is produced, the generation of bubbles cannot be sufficiently reduced. It is considered that the film provided on the outer surface of the enamel material may not necessarily be desired. Hydrogen permeates the film due to a dense film or a high-temperature environment, which causes deterioration of the film or a difference in thermal expansion coefficient between the platinum material and the film. Put it on the outside -6- 201014811 The glass bubble is controlled by the product. And the glass beta rate is made by the manufacturer of the method, and it can be made in the glass. In order to achieve the above object, the present invention is a glass manufacturing apparatus having a Φ presence and the like in order to achieve the above object. The member made of platinum or platinum alloy in contact with the molten glass is provided on the back side of the surface of the member in contact with the molten glass, and is formed to contain the total amount of the alumina-based ceramic particles in terms of Fe 203. A glass manufacturing apparatus characterized by a layer of alumina-based ceramic particles having a change point of Fe redox (Fe2 + /Fe2+ + Fe3+ ) in a molten glass temperature range of 5 mass%. In the glass manufacturing apparatus of the present invention, it is preferable that the member made of platinum or a platinum alloy is a container for accommodating molten glass. φ In the glass manufacturing apparatus of the present invention, the molten glass temperature range is preferably from 1,250 to 1,650 °C. In the glass production apparatus of the present invention, the alumina-based ceramic particles preferably contain 10% by mass or more of mullite. Further, the present invention provides a glass manufacturing method using the glass manufacturing apparatus of the present invention. In the glass manufacturing method of the present invention, the glass produced is represented by mass percentage (the total of SiO 2 , Al 2 〇 3, B 2 〇 3, MgO, CaO, SrO, and BaO is 100%) based on the oxide. : 201014811

Si02 5 0 ~ 7 0 % A 1 2 0 3 5~ 25% ' B 2 Ο 3 1~ 20% ' Μ gO 0~ 10%, CaO 0~ 17%, SrO 0~ 17%, BaO 0~ 2 0 %,

MgO + CaO + SrO + BaO 8 ~ 30 〇 / o is preferably an alkali-free glass. [Effect of the Invention] According to the glass manufacturing apparatus and the glass manufacturing method of the present invention, generation of bubbles at the lead interface or the lead alloy interface in contact with the molten glass can be effectively and stably prevented during the production of the glass. As a result, it is possible to produce a glass of good quality in which bubble residue is suppressed.

In particular, the alkali-free glass produced by the glass manufacturing apparatus and the glass manufacturing method of the present invention is applied to a substrate glass for a flat panel display, in particular, a liquid crystal display (LCD), an organic electroluminescence/display (OLED), Substrate glass for flat panel displays such as electromechanical illumination and displays. BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a glass manufacturing apparatus according to the present invention will be described. Fig. 1 is a schematic view showing an example of the configuration of a glass manufacturing apparatus. The glass manufacturing apparatus 1 of -8-201014811 shown in Fig. 1 has a melting tank 2, a clarification tank 3 provided on the downstream side of the melting tank 2, a stirring tank 4 provided on the downstream side of the clarification tank 3, and a downstream of the stirring tank 4. The side forming apparatus 5, the melting tank 2, the clarification tank 3, the stirring tank 4, and the molding apparatus 5 are connected via the ducts (contact passages) 6, 7, 8 which flow the molten glass respectively. The dissolution tank 2 is provided with a burner, an electrode, etc., and the glass raw material can be melted. On the downstream side of the melting tank 2, an outlet port for molten glass is formed, and the conduit 6 having the outlet port at the upstream end is connected to the melting tank 2 and the clarification tank 3 via φ. The clarification tank 3 is a portion where the glass is mainly clarified, and the fine bubbles contained in the molten glass are floated by the clarified gas discharged from the clarifying agent, and are removed by the molten glass. A flow outlet for molten glass is formed on the downstream side of the clarification tank 3, and the clarification tank 3 and the stirring tank 4 are connected via a conduit 7 whose upstream end is the outlet. The agitation tank 4 is a portion where the molten glass is stirred and homogenized mainly via a stirrer or the like. An outlet port is formed on the downstream side of the agitation vessel 4, and the agitation vessel 4 and the forming device 5 are communicated via a conduit 8 whose upstream end is φ such that the outlet port is φ. The molding device 5 is a portion that mainly shapes the glass into a desired shape, and is appropriately selected in accordance with the shape of the glass product to be produced. For example, when the glass product is a glass substrate for a flat panel display, a float forming apparatus, a pull-down forming apparatus, or the like is used. In the glass manufacturing apparatus 1 shown in Fig. 1, the contact portion with the molten glass of the melting tank 2 to the conduit 8 is required to have a heat resistance to a high temperature environment and corrosion resistance to molten glass, and a uranium material (i.e., platinum) is used. Or uranium alloy) is preferred. -9 - 201014811 The glass manufacturing apparatus of the present invention has a member made of platinum or a lead alloy which is in contact with the molten glass, and is formed on the back side of the surface of the member which is in contact with the molten glass with respect to the alumina-based ceramic particles. The total amount of Fe-containing oxide is 0.2 to 5% by mass of Fe, and the layer of alumina-based ceramic particles having a point of change in Fe redox (Fe2 + /Fe2+ + Fe3+) rise in the molten glass temperature range is characterized. . Here, as a specific example of a member made of platinum or a platinum alloy which is in contact with the molten glass, a container made of platinum or a platinum alloy containing the molten glass may be mentioned. However, the present invention is not limited thereto, and includes a member made of platinum or a platinum alloy which is in contact with the molten glass when the glass manufacturing apparatus is used. In the present specification, a specific example of a member made of platinum or a platinum alloy which is in contact with the molten glass is exemplified by a container made of platinum or a uranium alloy containing molten glass, but a container for accommodating the molten glass is used. The member made of platinum or a platinum alloy is explained as a member made of platinum or a platinum alloy. The container for accommodating the molten glass is generally a container for temporarily holding or accommodating the molten glass in the glass manufacturing step. One configuration example of the glass manufacturing apparatus 1 shown in FIG. 1 is the melting tank 2, the clarification tank 3, the stirring tank 4, and In the glass manufacturing apparatus of the present invention, at least one of the containers for accommodating the molten glass is made of a platinum material, and the back side of the surface of the container made of the platinum material in contact with the molten glass, that is, In a configuration example of the glass manufacturing apparatus shown in Fig. 1, the above-described alumina-based ceramic particle layer is formed on the outside of the container wall surface made of a platinum material. -10-201014811 In the past, it has been considered that a molecular diameter or an ion diameter of hydrogen is applied to form a dense film by coating or the like. However, the inventors of the present invention have diligently studied the results and found that the valence of Fe (Fe3 + e Fe 2+ ) contained in the alumina-based ceramic particles is not inhibited by the dense film formed by the material of hydrogen. effective.

The change in the valence of Fe is caused by an increase in the temperature of the platinum material due to an increase in the temperature of the molten glass (assuming that the temperature φ outside the container made of platinum material is almost the same as the temperature of the molten glass), and it is considered that the valence of Fe is changed. After that, while the temperature of the uranium material is maintained constant, the effect of suppressing the residual bubbles is almost constant. In the present invention, the alumina-based ceramic particle layer needs to contain a sufficient amount of Fe in order to exhibit the residual suppressing effect of the bubbles. Specifically, the alumina-based ceramic particles are preferably contained in an amount of 0.2 to 5% by mass in terms of Fe203 based on the total amount of the alumina-based ceramic particles, and more preferably 0.5% by mass or more. However, when the amount of Fe is large, φ is not mixed into the crystal structure of the alumina-based ceramic, and Fe203 remains in Hematite. Therefore, the change point of the Fe oxidation-reduction rise described later is lowered. Therefore, the content of Fe is preferably 5% by mass or less in terms of Fe203. Further, when the Fe contained in the alumina-based ceramic particles is used in a glass manufacturing apparatus, it is necessary to easily change the valence from Fe3 + to Fe2+. Therefore, the Fe contained in the alumina-based ceramic particles needs to have a change point of Fe redox (Fe2 + /Fe2+ + Fe3+) rise in the molten glass temperature range. When the temperature is plotted on the horizontal axis and Fe redox (Fe2 + /Fe2 + + Fe3+ ) is plotted on the vertical axis, Fe redox (Fe2 + /Fe2 + + Fe3+ ) rises sharply at a specific temperature. -11 - 201014811 In this specification, this temperature is called the point of change in Fe redox (Fe2 + /Fe2+ + Fe3H) rise. More specifically, the point at which the first differential 値 of the approximation curve of the above graph starts to increase with an increase in temperature is referred to as a change point. Further, Fe redox (Fe2 + /Fe2 + + Fe3+ ) of the alumina-based ceramic particles can be obtained by a redox titration method. Specifically, the sample of the alumina-based ceramic particles is heated to a specific temperature at a rate of 300 ° C per hour, and maintained at a specific temperature for 1 hour, and then cooled to room temperature, and Fe 2 is added to the solution in which the sample is dissolved in hydrofluoric acid. + indicator, the amount of Fe2+ was determined by spectrometry. Further, after the measurement sample was dissolved in fluoric acid, the Fe 3 + in the solution was reduced to Fe 2 +, and the amount of Fe 2 + was measured in the same manner as described above to determine the amount of Fe 3 + + Fe 2 + .

When the change in the Fe redox (Fe2 + /Fe2 + + Fe3+) rise is in the molten glass temperature range, when a glass manufacturing apparatus is used, more specifically, the wall surface made of the platinum material in the container for accommodating the molten glass is the molten glass. In the contact state, the valence change (Fe3 + -Fe2+) of Fe contained in the alumina-based ceramic particles is likely to occur. The molten glass temperature domain refers to the temperature domain experienced by the molten glass in the glass manufacturing step from melting to forming. The glass manufacturing apparatus 1 shown in Fig. 1 refers to a temperature range experienced by the molten glass from the melting tank 2 to the duct 8. The temperature range of the molten glass varies depending on the type of glass or the constituent elements of the glass manufacturing apparatus, but in the case of an alkali-free glass, it is usually 1 260 0 to 1 65 0 °C. It is preferable to constitute a molten glass temperature range of the entire glass manufacturing apparatus container which will be described later. The alumina-based ceramic particles used in the present invention have a change point of Fe redox increase in the molten glass temperature range, and the molten glass temperature range is -12-201014811 1250 to 165 (when TC, 10% by mass of mullite is contained) The content of the mullite is preferably 20% by mass or more, more preferably 30% by mass or more, and most preferably 40% by mass or more. The alumina-based ceramic particles may be a crystal phase containing only mullite, but When the mullite content satisfies the above range, it may contain other crystal phases, and specifically, it may contain smectite or steel jade. Further, as other components, it may contain pin stone, sillimanite, etc. φ Alumina ceramic particles The content of the glass phase is preferably 50% by mass or less, more preferably 30% by mass or less, still more preferably 20% by mass or less, and particularly preferably 10% by mass or less. When the content of the glass phase exceeds 50% by mass, the mullite phase The surface of the glass manufacturing apparatus of the present invention tends to exhibit a residual effect of suppressing the bubbles caused by the change in the valence of Fe. The glass manufacturing apparatus of the present invention also faces the back side of the surface of the container made of platinum material that is in contact with the molten glass. When the alumina-based ceramic particle φ sub-layer is formed on the outer side of the wall surface of the container (for example, the side surface and the bottom surface of the crucible container), the alumina-based ceramic particles are filled with a desired thickness on the outer side of the wall surface of the container. In order to exhibit the effect of suppressing the residual of the air bubbles, it is preferably 1 mm or more, more preferably 2 mm or more. Further, if the thickness is too large, it is necessary to use ceramic particles or more, and therefore it is preferably 40 mm or less. Specifically, on the outer side of the wall surface of the container, The container is provided with a fire-resistant block at a predetermined interval, and the alumina-based ceramic particles are filled between the container and the gap of the fire-resistant block. The fire-resistant block is fire-resistant and can retain alumina-based ceramic particles, and is not particularly limited, for example, burned. Into refractory, specifically, such as alumina stone, chrome, sillimanite, burned powder, alumina, magnesia, etc.. However, by the resistance of -13 - 201014811 fire block In view of ease of production (formability, workability, etc.) and cost, it is preferable to use alumina-based smelting. Further, the alumina-based ceramic using particles of the present invention is based on the wall surface of a container made of platinum material. It is convenient to charge, and it can be pulverized to a particle diameter of about 2 mm or less, and does not mean that it can be adjusted to a specific particle size distribution. In the present invention, the particle diameter refers to the size of particles which can be sieved through the size. When the particle diameter is 2 mm or less, it means particles passing through a sieve of 2 mm opening. However, the shape of the ceramic particle may be spherical, square, amorphous @, etc. It is considered to have sufficient contact points with the periphery of the container to fill the ceramic particles. In addition, it is preferable to use a particle size of 2 mm or less, and it is preferable to use a particle size of 10 μm or more in the case of preventing splashing during charging. In the present invention, the alumina-based ceramic particles which are filled on the outer side of the wall surface of the container made of platinum material can be used. The temperature of the molten glass to be accommodated in the container is appropriately selected. The temperature of the molten glass of the glass manufacturing apparatus varies depending on the entire container made of a platinum material, that is, the constituent elements of the glass manufacturing apparatus made of platinum material (the container containing the molten glass). For example, in the case of an alkali-free glass, in the glass manufacturing apparatus 1 shown in Fig. 1, the molten glass temperature in the melting tank 2 is about 1,400 to 1,650 ° C, and the molten glass temperature in the clarification tank 3 is about 1300 to 1550 ° C. The temperature of the molten glass in the stirring tank 4 is about 1250 to 140 ° C, the temperature of the molten glass in the duct 6 is about 1400 to 1600 ° C, and the temperature of the molten glass in the duct 7 is about 1,300 to 150 (about TC, the molten glass in the duct 8) The temperature is about 1250 to 1350 ° C. However, the present invention has a wall surface of a container made of a platinum material constituting the glass manufacturing apparatus, and has a molten glass temperature range accommodated in the container - 14 - 201014811

Alumina ceramic particles in which the point of change in Fe redox (Fe2 + /Fe2 + + Fe3+) rises. The method for producing a glass of the present invention is the same as that of the prior art except that the glass manufacturing apparatus of the present invention described above is used. Further, the melting tank 2 of the glass manufacturing apparatus shown in Fig. 1 is put into a raw material which is adjusted to have a desired glass composition, and the molten glass obtained by heating and melting is sequentially passed through the conduit 6, the clarification tank 3, the conduit 7, and the stirring tank 4. The duct 8 and the forming device 5 obtain a glass product having a desired shape of φ. According to the present invention, various glasses can be produced. An example of the alkali-free glass in the production of a suitable glass of the present invention is shown below. The alkali-free glass shown below is suitable as a substrate glass for a liquid crystal display (LCD). The alkali-free glass is expressed by mass percentage based on oxides and contains:

Si02 50 ～70% Al2〇3 5 - ^ 2 5% ' B 2 0 3 1~ , 2 0%, MgO 0~10%, CaO 0~ '17%, SrO 0~ '17%' BaO 0~ ' 20%,

MgO+CaO+SrO+BaO 8~30%. Further, the above-mentioned mass percentages are expressed as SiO 2 , A 1203 , B 2 〇 3 , ^ 〇 , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , S i Ο 2 is an essential component, and if it exceeds 70%, the meltability of the glass is lowered, or 201014811 becomes easily devitrified. It is preferably 64% or less. When it is less than 50%, the specific gravity increases, the strain point decreases, the coefficient of thermal expansion increases, and the chemical resistance decreases. It is preferably 55% or more.

Al2〇3 is necessary to suppress the phase separation of the glass or to increase the composition of the strain point (Strain Point). When it exceeds 25%, it becomes devitrified and causes a decrease in chemical resistance. It is preferably 2 2 % or less. If it is less than 5%, the glass becomes easy to separate into phases or the strain point is lowered. It is preferably 10% or more. 〇 B2〇3 is a component which makes the specific gravity small, improves the meltability of the glass, and makes it difficult to devitrify. When it exceeds 20%, the strain point is lowered, the chemical resistance is lowered, or the volatilization is remarkable when the glass is melted, and the glass heterogeneity is increased. It is preferably 12% or less. If it is less than 1%, the specific gravity increases' and the meltability of the glass decreases, and it becomes easy to devitrify. More preferably 6% or more 〇

MgO is a component which has a small specific gravity and improves the meltability of the glass. When it exceeds 1%, the glass becomes easily phase-separated, and it becomes easy to devitrify or the chemical resistance is lowered. It is preferably 7% or less. MgO is preferably 1% or more.

CaO is used to increase the melting property of glass and to make it difficult to devitrify to 7%. More than 1 7% ′, the specific gravity increases, and the coefficient of thermal expansion becomes larger, and on the contrary, it becomes devitrified. It is preferably 14% or less. CaO is preferably 2% or more.

In order to suppress the phase separation of the glass, SrO can be contained up to 17%. When it exceeds 7%, the specific gravity increases, and the coefficient of thermal expansion becomes large, and on the contrary, it becomes devitrified. It is preferably 14% or less. SrO is preferably 3% or more. BaO can be contained up to 20% 201014811 in order to suppress glass phase separation and make it difficult to devitrify. When it exceeds 20%, the specific gravity increases and the coefficient of thermal expansion becomes large. It is preferably 1% or less, and substantially does not contain it more preferably. When the total amount of the alkaline earth metal oxide (RO), that is, (MgO + CaO + SrO + BaO) is too small, the melting of the glass is difficult, so that it is 8% or more. On the other hand, if the amount is too large, the density of the glass becomes large, so it is at most 30%. It is preferably 1 0 to 3 0 %. On the other hand, the alkali-free glass is expressed by mass percentage based on the oxide, and contains: Si〇2 55 - -64% 'Al203 1 0 to 2 2 %, B 2 0 3 6 to 1 2 % 'MgO 1~ 7 % ' CaO 2~ 14% ' SrO 3~ 1 4 % ' BaO 0~ 1%,

MgO + CaO + SrO + BaO 10 〜30% is more preferable. Further, the above mass percentage means that the total of SiO 2 , ai 2 o 3 , b 2 o 3 , Mg 〇, CaO, SrO and BaO is 100%. In addition, in order to further suppress the bubbles in the molten glass, F, Cl, S03, Sn02, Fe203 or the like as a clarifying agent with respect to 100% by mass of the glass raw material and a total amount of 5% by mass or less may be added. [Embodiment] [Embodiment] -17- 201014811 Hereinafter, the present invention will be further described by way of Examples, but the present invention is not limited thereto. In the present embodiment, a crucible (made of JIS H6201 (1986.11.1)) made of a platinum alloy (platinum-niobium alloy '铑10% by mass) shown in Fig. 2(a) is used, and as shown in Fig. 2(b) The zirconia-made base (fire-resistant block) evaluates the generation of bubbles at the platinum alloy interface. The dimensions of the crucible shown in Fig. 2(a) and the base shown in Fig. 2(b) are as follows. Shabu pot height: 27mm Upper diameter: 2 5 mm Bottom diameter: 1 5 mm Capacity: 1Occ Mass: 8.0g Abutment outer dimension: 48mmx48mmx48mm Concave depth: 26mm Recessed diameter: 3 5 mm Also, the alumina system used in the examples Ceramic particles are shown in Table 1. The particle diameter is 1 〇 M m~2 mm. In Table 1, the ratio of the crystal phase to the glass phase (% by mass) in the alumina-based ceramic particles was determined by measuring the ratio of each crystal phase by a powder X-ray diffraction (XRD) method. Specifically, the ratio of the crystal phase is determined from the ratio of the XRD intensity of the pure substance (oblique zircon, zircon, mullite, steel jade, etc.) of each crystal phase to the sample, and the difference between the ratio of the sample and each crystal phase Find the ratio of the glass phase. Further, the composition ratio (mass% basis) of the alumina-based ceramic particles -18 to 201014811 was determined by fluorescent ray line analysis. Further, the composition ratio EROx is a total of oxidizing impurities other than A!2〇3, Si〇2, Ζγ02, and Fei〇3, and R is a metal element, lanthanum is oxygen, and X is a stoichiometric ratio. Table 1 Example 1 Example 2 Case 3 Case 4 Case 5 Case 6 Case 7 Crystalline phase zircon 12 Zircon mullite 48 31 40 100 29 97 100 Steel jade 44 41 15 10 Quartz 16 Hematite 3 m Each phase 8 16 45 45 Composition AI2O3 85.5 75 64 69 52 67 71 Si02 12 11 30 27 42 26 28 Zr02 13 Fe2〇3 0.4 0.3 3 3 2 6 0.1 EROx 2.1 0.7 3 1 4 1 0.9 Redox change point (°C) 1350 1350 1250 - 1300 1350 950 950 1350 Bubble occupancy (%) 0% 0.2% 2.8% 0% 36% 17% 15% Regarding the alumina ceramic particles of Examples 1, 3 and 5, the relationship between Fe redox and temperature The graph of the diagram is shown in Fig. 3» The crucible of Fig. 2(a) is placed in the recess of the base of Fig. 2(b) so that the gap is as shown in Fig. 2(c) (the gap between the recess of the abutment and the bottom of the crucible is 3 to 5 mm) The alumina-based ceramic particles shown in Table 1 are placed in a heating furnace and heated to 140 (TC). Then, in the state of TC, the alkali-free glass is placed in the crucible of Fig. 2. To make the melting. The composition of the alkali-free glass is based on the oxide of -19-201014811, expressed as mass percentage, which is SiO 2 59.4%,

Al2〇3 17.6% &gt; B2O37.9% 'MgO 3.3% &gt; CaO 3.8% 'SrO 8.0%' MgO + CaO + SrO 15.1%. After the alkali-free glass was melted, it was further maintained at 1400 ° C for 1 hour, and the generation of bubbles at the platinum alloy interface, that is, the wall surface of the crucible was observed. The results are shown in Table 1. In Table i, Examples 1 to 4 are Examples, and Examples 5 to 7 are Comparative Examples. In Table 1, the bubble occupancy ratio is the ratio of the area occupied by the bubble in the bottom surface of the crucible of Fig. 2(a), and 0% is below the measurement limit. As is clear from the results of Table 1, the alumina-based ceramic particles of Examples 1 to 4 were effective and stable in suppressing the remaining of the bubbles. Further, it is considered that the alumina-based ceramic particles of Examples 5 and 6 have a redox change point of 950 ° C, and in the molten glass temperature (1400 ° C) of the example, the valence change of Fe cannot be exhibited (Fe3 + - The residual suppression effect of bubbles caused by Fe2+). In addition, it is considered that the alumina-based ceramic particles of Example 7 have a redox change point of 1,350 ° C, and the Fe203 content is less than 0.2% by mass, so that bubbles of the valence of Fe (Fe3 + —Fe2+) cannot be sufficiently exhibited. Residual effect of the residue ❺ [Industrial Applicability] The glass-free device and the glass-manufacturing method of the present invention are used as a substrate glass for a flat panel display, particularly a liquid crystal display (LCD) or an organic battery. A substrate glass for a flat panel display such as a light-emitting display (〇LED), a non-electroluminescence, a display, etc. - 201014811 [Simplified description of the drawings] [Fig. 1] Fig. 1 shows an example of a configuration of a glass manufacturing apparatus Fig. 2(a) is a view showing a crucible made of a platinum alloy used in the embodiment, and Fig. 2(b) is a view showing a base of a chrome oxide smelting system used in the embodiment, Fig. 2 (Fig. 2 (Fig. 2) c) is a view showing a state in which the crucible of Fig. 2(a) is placed in the concave portion of the base φ of Fig. 2(b). Fig. 3 is a graph showing the relationship between the oxidation of Fe and the temperature of alumina-based ceramic particles of Examples 1, 3 and 5. t Main component symbol description] 1 : Glass manufacturing equipment 2 : Melting tank 3 : Clarification tank ® 4 : Stirring tank 5 : Forming device 6,7,8 : Catheter -21 -

Claims (1)

201014811 X. Patent Application No. 1 A glass manufacturing apparatus having a member made of platinum or a uranium alloy in contact with molten glass, characterized in that it is formed on the back side of the surface of the member in contact with the molten glass. The total amount of the alumina-based ceramic particles is Fe in an amount of ;.2 to 5% by mass in terms of Fe; i〇3, and has a Fe redox (Fe2 + /Fe2+ + Fe3+) rise in the molten glass temperature range. A layer of alumina ceramic particles that changes point. 2. The glass manufacturing apparatus of claim </ RTI> wherein the platinum or uranium alloy member is a container for containing molten glass. 3. The glass manufacturing apparatus of claim 1 or 2, wherein the molten glass temperature range is from 1250 to 1650 °C. 4. The glass manufacturing apparatus according to any one of claims 1 to 3, wherein the alumina-based ceramic particles contain 10% by mass or more of mullite. A glass manufacturing method characterized by using the glass manufacturing apparatus according to any one of claims 1 to 4. 6. The glass manufacturing method according to any one of claims 5, wherein the glass produced is expressed by mass percentage based on oxides (SiO 2 , Al 2 〇 3, B 2 〇 3, MgO, CaO, SrO, and The total of BaO is 100%) containing: Si02 50 〜70% A 1 2 0 3 5~ ^ 25% ' B2 〇3 1~ , 2 0%, MgO 0~ M0%, 201014811 SrO 0 〜1 7% , B a Ο 0 ～ 2 0 %, 8 〜3 0 % MgO+CaO+SrO+BaO alkali-free glass. -twenty three-