WO2014119708A1 - Method for manufacturing glass substrate - Google Patents

Method for manufacturing glass substrate Download PDF

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Publication number
WO2014119708A1
WO2014119708A1 PCT/JP2014/052211 JP2014052211W WO2014119708A1 WO 2014119708 A1 WO2014119708 A1 WO 2014119708A1 JP 2014052211 W JP2014052211 W JP 2014052211W WO 2014119708 A1 WO2014119708 A1 WO 2014119708A1
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WIPO (PCT)
Prior art keywords
glass
glass substrate
partition wall
internal partition
heating element
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PCT/JP2014/052211
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French (fr)
Japanese (ja)
Inventor
伸広 前田
裕介 塩地
Original Assignee
ＡｖａｎＳｔｒａｔｅ株式会社
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Application filed by ＡｖａｎＳｔｒａｔｅ株式会社 filed Critical ＡｖａｎＳｔｒａｔｅ株式会社
Priority to CN201480006297.0A priority Critical patent/CN104955775B/en
Priority to JP2014559763A priority patent/JP5981570B2/en
Publication of WO2014119708A1 publication Critical patent/WO2014119708A1/en

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    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B17/00—Forming molten glass by flowing-out, pushing-out, extruding or drawing downwardly or laterally from forming slits or by overflowing over lips
    • C03B17/06—Forming glass sheets
    • C03B17/064—Forming glass sheets by the overflow downdraw fusion process; Isopipes therefor
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P40/00—Technologies relating to the processing of minerals
    • Y02P40/50—Glass production, e.g. reusing waste heat during processing or shaping
    • Y02P40/57—Improving the yield, e-g- reduction of reject rates

Definitions

  • the present invention relates to a method for producing a glass substrate by a downdraw method.
  • a down draw method is used as a method for forming glass.
  • molten glass is poured into a groove of a molded body, and then the molten glass is overflowed from the groove. The molten glass then flows down along the side of the molded body. Molten glass merges at the lower end of the molded body, and then leaves the molded body to become sheet-like glass (sheet glass).
  • sheet glass is pulled and conveyed by a roller and cooled by the atmosphere in the furnace. Thereafter, the sheet glass is cut into a desired size and further processed into a glass substrate.
  • the glass plate manufacturing apparatus described in Patent Document 1 below includes an internal partition that partitions a heating element and a molded body in the furnace chamber.
  • the heat of the molten glass in the furnace chamber is exchanged with the internal partition wall heated by the heating element mainly through radiant heat transfer. A temperature distribution will occur in the direction. For this reason, as a material of an internal partition, a thing with large heat conductivity and high homogeneity is desirable.
  • Patent Document 1 describes that, for example, a SiC plate can be used for the internal partition.
  • an object of the present invention is to provide a method for producing a glass substrate that can suppress the oxidative expansion of an internal partition wall when producing the glass substrate by a downdraw method.
  • the method for producing a glass substrate of the present invention has the following aspects.
  • a method for producing a glass substrate having a step of forming molten glass into sheet glass by a downdraw method In the molding furnace chamber, provided with a heating element, the molded body, and an internal partition that partitions the heating element and the molded body, An SiC sintered body having an open porosity of 1% or less is used for the internal partition wall, A method for producing a glass substrate, comprising: heating the molten glass flowing through the molded body through the internal partition by the heating element.
  • the said internal partition is a manufacturing method of the glass substrate of the aspect 1 whose heat conductivity is 20 W / (m * K) or more at 1200 degreeC.
  • the said molten glass is a manufacturing method of the glass substrate of the aspect 1 or 2 which is 1000 degreeC or more when the viscosity of 10 ⁇ 5 > poise.
  • the method for producing a glass substrate which is an embodiment of the present invention, when a glass substrate is produced by the downdraw method, it is possible to suppress the occurrence of problems associated with the oxidative expansion of the internal partition walls.
  • FIG. 1 is a flowchart showing a part of the glass substrate manufacturing method according to the present embodiment.
  • the glass substrate is manufactured through various processes including a melting process ST1, a clarification process ST2, a homogenization process ST3, a molding process ST4, a cooling process ST5, and a cutting process ST6.
  • the melting process ST1 a clarification process ST2, a homogenization process ST3, a molding process ST4, a cooling process ST5, and a cutting process ST6.
  • the glass raw material is heated and melted.
  • Glass raw material is a composition such as SiO 2, Al 2 O 3.
  • the completely melted glass raw material becomes molten glass.
  • the molten glass is clarified. Specifically, the gas component contained in the molten glass is released from the molten glass, or the gas component is absorbed into the molten glass.
  • the homogenization step ST3 the molten glass is homogenized.
  • the molten glass is formed into a sheet-like glass, that is, a sheet glass by a downdraw method (specifically, an overflow downdraw method).
  • the sheet glass formed in the forming step ST4 is gradually cooled.
  • the sheet glass is cooled to near room temperature.
  • the cutting step ST6 the sheet glass cooled to near room temperature is cut every predetermined length to obtain a base glass.
  • disconnected for every predetermined length is cut
  • FIG. 2 is a schematic diagram showing the glass substrate manufacturing apparatus 100.
  • the glass substrate manufacturing apparatus 100 mainly includes a melting apparatus 200 and a forming apparatus 300.
  • the dissolution apparatus 200 is an apparatus for performing the dissolution process ST1, the clarification process ST2, and the homogenization process ST3. As shown in FIG. 2, the dissolution apparatus 200 includes a dissolution tank 201, a clarification tank 202, a stirring tank 203, a first pipe 204, and a second pipe 205.
  • the melting tank 201 is a tank for melting the glass raw material.
  • the dissolution step ST1 is performed.
  • the clarification tank 202 is a tank for removing bubbles from the molten glass melted in the melting tank 201. By further heating the molten glass fed from the melting tank 201 in the clarification tank 202, defoaming of the molten glass is promoted.
  • a clarification step ST2 is performed in the clarification tank 202.
  • the stirring tank 203 stirs the molten glass with a stirrer.
  • the homogenization step ST3 is performed.
  • the first pipe 204 and the second pipe 205 are pipes made of platinum group elements or platinum group element alloys.
  • the first pipe 204 is a pipe that connects the clarification tank 202 and the stirring tank 203.
  • the second pipe 205 is a pipe that connects the stirring tank 203 and the molding apparatus 300.
  • the molding apparatus 300 is an apparatus for performing the molding process ST4 and the cooling process ST5.
  • FIG. 3 is a schematic side view showing the forming furnace chamber 30 included in the forming apparatus 300.
  • the molding apparatus 300 includes a molding furnace chamber 30 at the top.
  • the forming furnace chamber 30 includes a furnace wall 24 as an outer wall, and is partitioned from the lower furnace chamber by a partition member 20.
  • a molded body 14 and a plurality of heating elements 28 are arranged inside the molding furnace chamber 30, a molded body 14 and a plurality of heating elements 28 are arranged.
  • an internal partition wall 16 that partitions the molded body 14 and the heating element 28 is provided.
  • the molded body 14 is an apparatus for performing the molding step ST4 and is provided in the molding furnace chamber 30.
  • the formed body 14 has a function of forming the molten glass flowing from the melting apparatus 200 into a sheet-like glass substrate (sheet glass G) by an overflow down draw method.
  • the molded body 14 has a wedge-shaped cross-sectional shape cut in the vertical direction, and is composed of, for example, refractory bricks made of zircon, zirconia, YPO 4 , Al 2 O 3 , SiO 2 , SiC, SiN, and combinations thereof. ing.
  • a groove portion 18 that receives the molten glass MG flowing from the melting device 200 is formed in the upper portion of the molded body 14.
  • the side surface 14b of the molded body 14 is formed along the vertical direction so that the molten glass MG overflowed from the groove 18 flows down.
  • the inclined surface 14c of the molded body 14 has a side surface 14b so that the molten glass MG flowing down the both side surfaces 14b, 14b of the molded body 14 joins at the lowermost end portion 14d, which is the apex of the wedge-shaped cross section of the molded body 14. It is inclined with respect to.
  • the inner partition wall 16 is disposed between the heating element 28 and the molded body 14 and is disposed around the molded body 14 so as to surround the molded body 14.
  • the internal partition 16 is made of a SiC sintered body, and more specifically, is made of a high-density sintered SiC plate.
  • the internal partition 16 is preferably composed of a SiC sintered body having a SiC content of 95 wt% (wt%) or more. Further, from the viewpoint of improving the temperature uniformity of the internal partition wall 16, the thermal conductivity at 1200 ° C. is 20 W / (m ⁇ K) or more, more preferably 25 W / (m ⁇ K) or more, and further preferably 30 W / (m.
  • the SiC sintered compact which is more than K).
  • the upper limit of the thermal conductivity is, for example, 490 W / (m ⁇ K).
  • the open porosity of the SiC sintered body constituting the internal partition wall 16 is set to 1% or less.
  • the open porosity of the SiC sintered body is preferably 0.8% or less, and more preferably 0.6% or less.
  • the open porosity of the SiC sintered body is, for example, more than 0%.
  • the open porosity is a percentage of the volume of the open pore portion in the sample when the outer volume of the sample is 1, and is measured by a measurement method defined in JIS R 1634: 1998, for example. Can do.
  • a horizontal partition wall 26 is provided between the furnace wall 24 and the internal partition wall 16 to partition the space between the furnace wall 24 and the internal partition wall 16 in the lateral direction.
  • the horizontal partition wall 26 is a plate-like member that partitions the space between the furnace wall 24 of the molding furnace chamber 30 and the internal partition wall 16 into a plurality of vertically adjacent spaces.
  • zircon, zirconia, YPO 4 , Al It is a heat insulating member made of 2 O 3 , SiO 2 , SiC, SiN and combinations thereof.
  • a heating element 28 is disposed in each of the small spaces partitioned by the horizontal partition wall 26.
  • the molding furnace chamber 30 may be partitioned into a plurality of spaces, and the temperature of each partitioned space may be controlled by the heating element 28, and the position and number of the horizontal partition walls 26 are arbitrary.
  • the horizontal partition wall 26 is disposed at a position where the distance from the adjacent heating element 28 is constant at regular intervals.
  • the thickness of the horizontal partition 26 can be set arbitrarily, for example, it can be made the same as the thickness of the internal partition 16 and the thickness of the furnace wall 24.
  • the heat transfer amount transmitted by the horizontal partition wall 26 and the internal partition wall 16 is made equal by making the thickness the same, and the molten glass MG is uniformly heated in the width direction. can do.
  • the thermal conductivity of the internal partition 16 provided at a position closer to the molten glass MG is set.
  • the thermal conductivity of the horizontal partition wall 26 can be made higher.
  • the open porosity of the internal partition wall 16 can be made lower than the open porosity of the horizontal partition wall 26.
  • the thermal conductivity of the internal partition wall 16 located at the position facing the lowermost end portion 14d is set to both side surfaces 14b, 14b.
  • the open porosity of the internal partition wall 16 at the position facing the lowermost end portion 14d can be made lower than the open porosity of the internal partition wall 16 at the position facing both side surfaces 14b, 14b.
  • the heating element 28 is composed of, for example, a sheathed heater, a cartridge heater, or a ceramic heater that generates heat by resistance heating, dielectric heating, microwave heating, induction heating, etc., and the amount of generated heat (temperature) can be arbitrarily adjusted.
  • Each heating element 28 disposed in the molding furnace chamber 30 can independently control the amount of heat generated. For example, when the molten glass MG travels downward in the molding furnace chamber 30, the grooves 18 and both side surfaces of the molding body 14. A temperature gradient can be formed so that the temperature sequentially decreases toward 14b, 14b, the inclined surface 14c, and the lowermost end portion 14d. That is, the amount of heat generated by the plurality of heating elements 28 is adjusted so that the temperature of the wall surface facing the molded body 14 of the internal partition wall 16 decreases as the molten glass MG flows. Is preferred.
  • the partition member 20 is a plate-like member disposed in the vicinity of the lowermost end portion 14d of the forming body 14, for example, zircon, zirconia, YPO 4, Al 2 O 3 , SiO 2, SiC, SiN and a combination thereof It is the heat insulation member which consists of.
  • a pair of partition members 20 are provided such that the ends thereof are opposed to each other.
  • the partition member 20 is disposed so as to be horizontal on both sides in the thickness direction of the sheet glass G flowing down from the lowermost end portion 14d of the molded body 14.
  • the partition member 20 suppresses the movement of heat from the upper side to the lower side of the partition member 20 by partitioning and insulating the upper and lower atmospheres leaving a gap through which the sheet glass passes.
  • a cooling roller 22 is disposed below the partition member 20.
  • the cooling roller 22 is disposed in a furnace chamber located below the partition member 20. Moreover, the cooling roller 22 is arrange
  • the cooling roller 22 is air-cooled by, for example, an air-cooling tube passed through the inside.
  • the cooling roller 22 pulls the sheet glass G downward by transmitting the driving force of the driving motor.
  • a slow cooling furnace chamber (not shown) for performing the cooling step ST5 is provided below the forming furnace chamber 30, a slow cooling furnace chamber (not shown) for performing the cooling step ST5 is provided.
  • the slow cooling furnace chamber is partitioned into a plurality of furnace chambers along the flow of the sheet glass G, and a plurality of tension rollers are provided along the flow of the sheet glass G.
  • the pulling roller is driven by a motor and conveys the seed glass G while pulling it downward.
  • Each furnace chamber is provided with a heater for adjusting the temperature of the atmosphere around the sheet glass G. By controlling the temperature of the atmosphere around the sheet glass G using this heater, the temperature of the sheet glass G is controlled, and the sheet glass is subjected to a temperature profile that reduces the thickness deviation, warpage, and distortion of the sheet glass G. G is gradually cooled.
  • the cutting step ST6 is performed by a cutting device (not shown).
  • the cutting device is disposed below the slow cooling furnace chamber.
  • the cutting device is a device that cuts the sheet glass G flowing down in the forming device 300 in a direction perpendicular to the longitudinal surface thereof.
  • the sheet-like sheet glass G becomes a plurality of base plates having a predetermined length by being cut by a cutting device.
  • the base plate is further cut, packaged through end face processing, cleaning, and inspection, and shipped as a glass substrate.
  • the molten glass MG that has flowed through the groove 18 of the molded body 14 overflows at the top of the groove 18 and flows down along both side surfaces 14b and 14b of the molded body 14.
  • the molten glass G which flowed down along the both side surfaces 14b and 14b of the molded object 14 merges in the lowest end part 14d of the molded object 14 via the inclined surfaces 14c and 14c, and becomes the sheet glass G.
  • the sheet glass G is supplied to a slow cooling furnace chamber below the forming furnace chamber 30 through a slit-like gap between the pair of partition members 20 and 20.
  • the internal partition 16 is heated by the heating element 28, heat exchange is performed between the heated internal partition 16 and the molten glass MG flowing through the molded body 14, and the molten glass MG is cooled.
  • the atmosphere containing oxygen in the forming furnace chamber 30 is maintained at a temperature of 1000 ° C. or more, for example, about 1200 ° C., but the internal partition wall 16 is exposed to the atmosphere containing oxygen at such a high temperature,
  • the SiC sintered body constituting the partition 16 is oxidized from the portion in contact with oxygen and changed to SiO 2 .
  • the open porosity of the SiC sintered body is larger than 1%, the oxidation tends to proceed not only from the surface but also from the inside. In a place where internal oxidation has progressed, the volume increases, leading to deformation and even cracking.
  • the SiC sintered body is a material that is resistant to high temperatures and excellent in heat resistance and oxidation resistance.
  • the oxidation start temperature at which the SiC sintered body reacts with oxygen is about 700 ° C., and when this temperature is exceeded, oxidation starts, leading to deformation and further cracking. Since the temperature in the molding furnace chamber 30 is 1000 ° C. or higher as described above, the SiC sintered body is easily oxidized in the molding furnace chamber 30.
  • a SiC sintered body having an open porosity of 1% or less is used for the internal partition wall 16. Therefore, only the surface comes into contact with the high temperature atmosphere containing oxygen, and the progress of SiC oxidation inside the tissue can be suppressed. Thereby, abnormal expansion due to internal oxidation of the internal partition wall 16 is suppressed, and deformation, surface cracks, and generation of cracks can be suppressed. Therefore, it is possible to prevent the soaking effect of the internal partition wall 16 from being lowered, and to improve the quality of the glass substrate. Moreover, the lifetime of the internal partition 16 can be extended and the productivity of the glass substrate can be improved. Further, when the SiC sintered body is oxidized, the oxide SiO 2 completely covers the surface of the SiC sintered body and becomes a protective film against oxidation, so that the internal oxidation of the internal partition wall 16 can be suppressed.
  • FIG. 4 is a view for explaining the temperature distribution around the heating element 28, and is a view of the molten glass MG, the internal partition wall 16, and the heating element 18 as viewed from above in FIG.
  • the heating element 28 When the heating element 28 generates heat, the heat generated from the heating element 28 spreads in a spherical shape around the heating element 28, and in the small space surrounded by the internal partition wall 16, the horizontal partition wall 26, and the furnace wall 24, A spherical temperature distribution with a center is formed.
  • the heat spread in a spherical shape reaches the inner partition wall 16, the heat is absorbed by the inner partition wall 16, and heat is accumulated in the inner partition wall 16. Since the internal partition wall 16 has a soaking effect, the heat accumulated in the internal partition wall 16 is released in a planar shape along the side wall of the internal partition wall 16.
  • a substantially constant temperature distribution is formed along the internal partition 16 along at least the width direction of the molten glass MG. Due to the substantially constant temperature distribution along the internal partition wall 16, the temperature of the molten glass MG becomes uniform in the width direction of the molten glass MG, and the temperature of the sheet glass G is, for example, about 1150 at the lowermost end portion 14 d of the molded body 14. It becomes uniform in the width direction at °C.
  • the internal partition 16 of the present embodiment has a thermal conductivity of 20 W / (m ⁇ K) or more at 1200 ° C., more preferably 25 W / (m ⁇ K) or more, and further preferably 30 W / (m ⁇ K). ) That's it. Therefore, even if the temperature of each heating element 28 varies from place to place, the temperature of the internal partition wall 16 is less varied depending on the place in the width direction of the molten glass MG, and the temperature tends to be uniform in the width direction of the molten glass MG.
  • the soaking effect of the internal partition 16 can be improved, and the temperature of the molten glass MG flowing through the molded body 14 can be cooled more uniformly in the width direction of the molten glass MG, thereby improving the quality of the glass substrate.
  • the atmosphere between the furnace wall 24 and the internal partition wall 16 in the molding furnace chamber 30 is maintained at a required temperature by the heating element 28.
  • a horizontal partition wall 26 that partitions the molding furnace chamber 30 into a plurality of vertically adjacent spaces is provided between the furnace wall 24 of the molding furnace chamber 30 and the internal partition wall 16.
  • a plurality of heating elements 28 are provided in the plurality of spaces partitioned by the horizontal partition walls 26, and each heating element 28 can independently control the amount of heat generation.
  • the horizontal partition wall 26 is made of a material having a high heat insulating property, for example, a material having a high heat insulating property compared to the internal partition wall 16.
  • a temperature difference can be given and the quality of a glass substrate can be improved.
  • a heating element based on a temperature measured by a temperature sensor (not shown) such as a resistance temperature detector or a thermocouple installed in the molding furnace chamber 30.
  • the amount of heat generated by 28 can be adjusted. For example, when the temperature measured by the temperature sensor is the same on both side surfaces 14b and 14b of the molded body 14 and the inclined surface 14c, the amount of heat generated by the heating element 28 at a position facing the both side surfaces 14b and 14b. Or by suppressing the amount of heat generated by the heating element 28 at a position facing the inclined surface 14c, a temperature difference is caused in the flow direction in the molten glass MG flowing through the side surfaces 14b, 14b and the inclined surface 14c. Can do.
  • the manufacturing method of this embodiment is suitable when the inside of the molding furnace needs to be kept at a high temperature. Specifically, it is suitable when the inside of the molding furnace is 1000 ° C. or higher, more suitable when it is 1200 ° C. or higher, and particularly suitable when it is 1300 ° C. or higher.
  • this embodiment uses glass (molten glass) having a high high temperature viscosity. Suitable for manufacturing glass substrates.
  • the viscosity of the glass (molten glass) when the viscosity of the glass (molten glass) is 10 5 poise, it is suitable for manufacturing a glass substrate using glass (molten glass) that is 1000 ° C. or higher. Moreover, the upper limit of the temperature of a molten glass when a viscosity is 10 ⁇ 5 > poise is 1700 degreeC, for example.
  • alkali-free glass or alkali-containing glass containing a trace amount of alkali metal has high viscosity at high temperature
  • this embodiment is suitable for manufacturing a glass substrate composed of alkali-free glass or alkali-containing glass.
  • a glass substrate having the following composition range is shown by mass%. SiO 2 : 50 to 70%, Al 2 O 3 : 0 to 25%, B 2 O 3 : 1 to 15%, MgO: 0 to 10%, CaO: 0-20%, SrO: 0 to 20%, BaO: 0 to 10%, RO: Alkali-free glass containing 5 to 30% (where R is the total amount of Mg, Ca, Sr and Ba).
  • the glass substrate may be a glass containing a trace amount of alkali metal containing a trace amount of alkali metal.
  • the total of R ′ 2 O is 0.10% or more and 0.5% or less, preferably 0.20% or more and 0.5% or less (where R ′ is selected from Li, Na, and K) It is preferable that the glass substrate contains at least one kind. Of course, the total of R ′ 2 O may be less than 0.10%. That is, the present invention is suitable for manufacturing a flat panel display using an alkali-free glass or a glass substrate with a small amount of alkali.
  • the glass substrate was manufactured using the glass substrate manufacturing apparatus demonstrated in the above-mentioned embodiment.
  • As the inner partition wall high-density sintered SiC having a SiC content of 99 wt%, a thermal conductivity of 25 W / (m ⁇ K) at 1200 ° C., and an open porosity of 1% was used.
  • a glass substrate was manufactured using the glass substrate manufacturing apparatus described in the above embodiment.
  • high-density sintered SiC having a SiC content of 98 wt%, a thermal conductivity of 30 W / (m ⁇ K) at 1200 ° C., and an open porosity of 0.6% was used.
  • a glass substrate was manufactured using the glass substrate manufacturing apparatus described in the above embodiment.
  • high-density sintered SiC having a SiC content of 95 wt%, a thermal conductivity of 35 W / mK at 1200 ° C., and an open porosity of 0.5% was used.
  • Molded body 16 Internal partition wall 24 Furnace wall 26 Horizontal partition wall 28 Heating element 30 Molding furnace chamber MG Molten glass G Sheet glass

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Furnace Details (AREA)
  • Glass Compositions (AREA)
  • Re-Forming, After-Treatment, Cutting And Transporting Of Glass Products (AREA)
  • Ceramic Products (AREA)

Abstract

In a method for manufacturing a glass substrate with a down draw method, a bushing chamber (30) is provided with a heating element (28), a molding body (14) and an inner partition wall (16) that divides the heating element (28) and the molding body (14). An SiC sintered body with an open porosity of 1% or less is used for the inner partition wall (16), and molten glass (MG) which flows over the molding body (14) is heated by the heating element (28) via the inner partition wall (16). Thus, oxidation expansion of the inner partition wall (16) can be suppressed.

Description

ガラス基板の製造方法Manufacturing method of glass substrate
　本発明は、ダウンドロー法によるガラス基板の製造方法に関する。 The present invention relates to a method for producing a glass substrate by a downdraw method.
　ガラス基板の製造工程において、ガラスを成形する方法としてダウンドロー法が用いられている。ダウンドロー法では、成形体の溝に溶融ガラスを流し込んだ後、溶融ガラスを溝からオーバーフローさせる。溶融ガラスは、その後、成形体の側面に沿って流下する。溶融ガラスは、成形体の下端部で合流し、その後、成形体を離れてシート状のガラス（シートガラス）となる。シートガラスは、ローラによって下方に引っ張られて搬送され、炉内の雰囲気によって冷却される。その後、シートガラスは、所望の大きさに切断され、さらに加工されてガラス基板となる。 In the manufacturing process of a glass substrate, a down draw method is used as a method for forming glass. In the downdraw method, molten glass is poured into a groove of a molded body, and then the molten glass is overflowed from the groove. The molten glass then flows down along the side of the molded body. Molten glass merges at the lower end of the molded body, and then leaves the molded body to become sheet-like glass (sheet glass). The sheet glass is pulled and conveyed by a roller and cooled by the atmosphere in the furnace. Thereafter, the sheet glass is cut into a desired size and further processed into a glass substrate.
　下記の特許文献１に記載されたガラス板の製造装置は、炉室内の発熱体と成形体とを仕切る内部隔壁を備えている。炉室内の溶融ガラスの熱は発熱体により加熱された内部隔壁との間で主に輻射熱伝達を介して熱交換されるため、内部隔壁面に温度分布あると対向する溶融ガラスの面にも幅方向に温度分布が発生することになる。このため、内部隔壁の材質としては、熱伝導率が大きく、かつ均質度の高いものが望ましい。特許文献１では、上記内部隔壁に、例えばＳｉＣ製の板が使用できることが記載されている。 The glass plate manufacturing apparatus described in Patent Document 1 below includes an internal partition that partitions a heating element and a molded body in the furnace chamber. The heat of the molten glass in the furnace chamber is exchanged with the internal partition wall heated by the heating element mainly through radiant heat transfer. A temperature distribution will occur in the direction. For this reason, as a material of an internal partition, a thing with large heat conductivity and high homogeneity is desirable. Patent Document 1 describes that, for example, a SiC plate can be used for the internal partition.
登録実用新案第２５３００６０号公報Registered Utility Model No. 2530060
　しかし、熱伝導率が大きくかつ均質度の高いＳｉＣ製の板を内部隔壁として用いた場合であっても、気孔率が高い材料で作られた内部隔壁の場合は、成形炉室内の高温雰囲気に長時間曝されると内部隔壁の内部に、内部の気孔によりＳｉが酸化してＳｉＯ２が形成されることで異常膨張し、変形したり、表面に亀裂が入ったり、割れたりすることがある。このような内部隔壁の変形、表面の亀裂、割れが発生すると、内部隔壁の均熱効果が低下してガラス基板の品質が低下したり、内部隔壁の交換が必要になってガラス基板の生産性が低下したりする。
　そこで、本発明は、ダウンドロー法によってガラス基板を製造するに際し、内部隔壁の酸化膨張を抑制することができるガラス基板の製造方法を提供することを目的とする。 However, even when a SiC plate having a high thermal conductivity and high homogeneity is used as the internal partition wall, the internal partition wall made of a material with high porosity has a high temperature atmosphere in the molding furnace chamber. When exposed to a long period of time, inside the internal partition wall, Si is oxidized by the internal pores and SiO 2 is formed, which causes abnormal expansion, deformation, cracking on the surface, and cracking. . When such deformation of the internal partition walls, cracks on the surface, or cracks occur, the soaking effect of the internal partition walls decreases, and the quality of the glass substrate deteriorates or the internal partition walls need to be replaced, resulting in the productivity of the glass substrate. Or drop.
Therefore, an object of the present invention is to provide a method for producing a glass substrate that can suppress the oxidative expansion of an internal partition wall when producing the glass substrate by a downdraw method.
　本発明のガラス基板の製造方法は、以下の態様を有する。 The method for producing a glass substrate of the present invention has the following aspects.
［態様１］
　ダウンドロー法により溶融ガラスをシートガラスに成形する工程を有するガラス基板の製造方法であって、
　成形炉室に、発熱体と、前記成形体と、前記発熱体と前記成形体とを仕切る内部隔壁と、を設け、
　前記内部隔壁に開気孔率が１％以下のＳｉＣ焼結体を用い、
　前記発熱体により前記内部隔壁を介して前記成形体を流れる前記溶融ガラスを加熱することを特徴とするガラス基板の製造方法。 [Aspect 1]
A method for producing a glass substrate having a step of forming molten glass into sheet glass by a downdraw method,
In the molding furnace chamber, provided with a heating element, the molded body, and an internal partition that partitions the heating element and the molded body,
An SiC sintered body having an open porosity of 1% or less is used for the internal partition wall,
A method for producing a glass substrate, comprising: heating the molten glass flowing through the molded body through the internal partition by the heating element.
［態様２］
　前記内部隔壁は、熱伝導率が１２００℃で２０Ｗ／（ｍ・Ｋ）以上である、態様１に記載のガラス基板の製造方法。 [Aspect 2]
The said internal partition is a manufacturing method of the glass substrate of the aspect 1 whose heat conductivity is 20 W / (m * K) or more at 1200 degreeC.
［態様３］
　前記溶融ガラスは、１０５ｐｏｉｓｅの粘度のとき、１０００℃以上である、態様１又は２に記載のガラス基板の製造方法。 [Aspect 3]
The said molten glass is a manufacturing method of the glass substrate of the aspect 1 or 2 which is 1000 degreeC or more when the viscosity of 10 < 5 > poise.
［態様４］
　前記ガラス基板は、無アルカリガラス又はアルカリ微量含有ガラスである、態様1～３のいずれか１項に記載のガラス基板の製造方法。 [Aspect 4]
The method for producing a glass substrate according to any one of aspects 1 to 3, wherein the glass substrate is an alkali-free glass or a glass containing a trace amount of alkali.
［態様５］
　前記成形炉室の炉壁と前記内部隔壁との間の空間を、水平隔壁によって上下に隣接する複数の小空間に区画し、
　前記小空間の各々に前記発熱体を配置する、態様１～４のいずれか１項に記載のガラス基板の製造方法。 [Aspect 5]
The space between the furnace wall of the molding furnace chamber and the internal partition is partitioned into a plurality of small spaces adjacent to each other by a horizontal partition,
The method for producing a glass substrate according to any one of aspects 1 to 4, wherein the heating element is disposed in each of the small spaces.
［態様６］
　前記内部隔壁の前記成形体の側に面する壁面の温度は、前記熔融ガラスの流れる方向に進むにしたがって、温度が下がるように、前記発熱体の発熱量を調整する、態様５に記載のガラス基板の製造方法。 [Aspect 6]
The glass according to aspect 5, wherein a temperature of a wall surface facing the molded body side of the inner partition wall is adjusted in a calorific value of the heating element such that the temperature decreases as the molten glass proceeds in a flowing direction. A method for manufacturing a substrate.
　本発明の一態様であるガラス基板の製造方法によれば、ダウンドロー法によってガラス基板を製造するに際し、内部隔壁の酸化膨張に伴う問題の発生を抑制することができる。 According to the method for producing a glass substrate which is an embodiment of the present invention, when a glass substrate is produced by the downdraw method, it is possible to suppress the occurrence of problems associated with the oxidative expansion of the internal partition walls.
本実施形態に係るガラス基板の製造方法の一部のフローチャートである。It is a flowchart of a part of manufacturing method of the glass substrate which concerns on this embodiment. 本実施形態のガラス基板の製造方法に用いるガラス基板製造装置を示す模式図である。It is a schematic diagram which shows the glass substrate manufacturing apparatus used for the manufacturing method of the glass substrate of this embodiment. 図２に示すガラス基板製造装置に含まれる成形装置の一部を示す側面図である。It is a side view which shows a part of shaping | molding apparatus contained in the glass substrate manufacturing apparatus shown in FIG. 本実施形態の発熱体周辺の温度分布を説明する図である。It is a figure explaining the temperature distribution around the heat generating body of this embodiment.
　以下、図面を参照しながら、本実施形態のガラス基板の製造方法について説明する。
　図１は、本実施形態に係るガラス基板の製造方法の一部を示すフローチャートである。
　図１に示すように、ガラス基板は、溶解工程ＳＴ１と、清澄工程ＳＴ２と、均質化工程ＳＴ３と、成形工程ＳＴ４と、冷却工程ＳＴ５と、切断工程ＳＴ６とを含む種々の工程を経て製造される。 Hereinafter, the manufacturing method of the glass substrate of this embodiment is demonstrated, referring drawings.
FIG. 1 is a flowchart showing a part of the glass substrate manufacturing method according to the present embodiment.
As shown in FIG. 1, the glass substrate is manufactured through various processes including a melting process ST1, a clarification process ST2, a homogenization process ST3, a molding process ST4, a cooling process ST5, and a cutting process ST6. The
　溶解工程ＳＴ１では、ガラス原料を加熱して溶解する。ガラス原料は、ＳｉＯ２、Ａｌ２Ｏ３等の組成からなる。完全に溶解したガラス原料は、溶融ガラスとなる。
　清澄工程ＳＴ２では、溶融ガラスを清澄する。具体的には、溶融ガラス中に含まれるガス成分を溶融ガラスから放出する、或いは、ガス成分を溶融ガラス中に吸収する。
　均質化工程ＳＴ３では、溶融ガラスを均質化する。
　成形工程ＳＴ４では、ダウンドロー法（具体的には、オーバーフローダウンドロー法）により溶融ガラスをシート状のガラス、すなわちシートガラスに成形する。
　冷却工程ＳＴ５では、成形工程ＳＴ４で成形されたシートガラスの徐冷を行う。当該冷却工程ＳＴ５において、シートガラスは、室温近くまで冷却される。
　切断工程ＳＴ６では、室温近くまで冷却されたシートガラスを、所定の長さ毎に切断して素板ガラスとする。
　なお、所定の長さ毎に切断された素板ガラスは、その後、さらに切断されて、研削・研磨、洗浄、検査が行われてガラス基板となり、液晶ディスプレイ等のフラットパネルディスプレイに使用される。 In the melting step ST1, the glass raw material is heated and melted. Glass raw material is a composition such as SiO 2, Al 2 O 3. The completely melted glass raw material becomes molten glass.
In the clarification step ST2, the molten glass is clarified. Specifically, the gas component contained in the molten glass is released from the molten glass, or the gas component is absorbed into the molten glass.
In the homogenization step ST3, the molten glass is homogenized.
In the forming step ST4, the molten glass is formed into a sheet-like glass, that is, a sheet glass by a downdraw method (specifically, an overflow downdraw method).
In the cooling step ST5, the sheet glass formed in the forming step ST4 is gradually cooled. In the cooling step ST5, the sheet glass is cooled to near room temperature.
In the cutting step ST6, the sheet glass cooled to near room temperature is cut every predetermined length to obtain a base glass.
In addition, the base glass cut | disconnected for every predetermined length is cut | disconnected further after that, grinding | polishing / polishing, washing | cleaning, and an inspection are performed, it becomes a glass substrate, and is used for flat panel displays, such as a liquid crystal display.
　次に、本実施形態のガラス基板の製造方法に用いるガラス基板製造装置について説明する。
　図２は、ガラス基板製造装置１００を示す模式図である。
　ガラス基板の製造装置１００は、主として、溶解装置２００と、成形装置３００とを有する。 Next, the glass substrate manufacturing apparatus used for the manufacturing method of the glass substrate of this embodiment is demonstrated.
FIG. 2 is a schematic diagram showing the glass substrate manufacturing apparatus 100.
The glass substrate manufacturing apparatus 100 mainly includes a melting apparatus 200 and a forming apparatus 300.
　溶解装置２００は、溶解工程ＳＴ１、清澄工程ＳＴ２、及び、均質化工程ＳＴ３を行うための装置である。溶解装置２００は、図２に示すように、溶解槽２０１、清澄槽２０２、攪拌槽２０３、第１配管２０４、及び、第２配管２０５を有する。
　溶解槽２０１は、ガラス原料を溶解するための槽である。溶解槽２０１では、溶解工程ＳＴ１を行う。
　清澄槽２０２は、溶解槽２０１で溶解された溶融ガラスから泡を除去するための槽である。溶解槽２０１より送り込まれた溶融ガラスを、清澄槽２０２でさらに加熱することで、溶融ガラスの脱泡が促進される。清澄槽２０２では、清澄工程ＳＴ２を行う。
　攪拌槽２０３は、スターラーによって溶融ガラスを攪拌する。攪拌槽２０３では、均質化工程ＳＴ３を行う。
　第１配管２０４及び第２配管２０５は、白金族元素又は白金族元素の合金製の配管である。第１配管２０４は、清澄槽２０２と攪拌槽２０３とを接続する配管である。第２配管２０５は、攪拌槽２０３と成形装置３００とを接続する配管である。 The dissolution apparatus 200 is an apparatus for performing the dissolution process ST1, the clarification process ST2, and the homogenization process ST3. As shown in FIG. 2, the dissolution apparatus 200 includes a dissolution tank 201, a clarification tank 202, a stirring tank 203, a first pipe 204, and a second pipe 205.
The melting tank 201 is a tank for melting the glass raw material. In the dissolution tank 201, the dissolution step ST1 is performed.
The clarification tank 202 is a tank for removing bubbles from the molten glass melted in the melting tank 201. By further heating the molten glass fed from the melting tank 201 in the clarification tank 202, defoaming of the molten glass is promoted. In the clarification tank 202, a clarification step ST2 is performed.
The stirring tank 203 stirs the molten glass with a stirrer. In the stirring tank 203, the homogenization step ST3 is performed.
The first pipe 204 and the second pipe 205 are pipes made of platinum group elements or platinum group element alloys. The first pipe 204 is a pipe that connects the clarification tank 202 and the stirring tank 203. The second pipe 205 is a pipe that connects the stirring tank 203 and the molding apparatus 300.
　成形装置３００は、成形工程ＳＴ４、及び、冷却工程ＳＴ５を行うための装置である。
　図３は、成形装置３００に含まれる成形炉室３０を示す概略の側面図である。
　成形装置３００は、図３に示すように、最上部に成形炉室３０を備えている。成形炉室３０は、外壁として炉壁２４を備え、仕切り部材２０によって下側の炉室と区画されている。成形炉室３０の内部には、成形体１４と、複数の発熱体２８とが配置されている。成形体１４の周囲には、成形体１４と発熱体２８とを仕切る内部隔壁１６が設けられている。 The molding apparatus 300 is an apparatus for performing the molding process ST4 and the cooling process ST5.
FIG. 3 is a schematic side view showing the forming furnace chamber 30 included in the forming apparatus 300.
As shown in FIG. 3, the molding apparatus 300 includes a molding furnace chamber 30 at the top. The forming furnace chamber 30 includes a furnace wall 24 as an outer wall, and is partitioned from the lower furnace chamber by a partition member 20. Inside the molding furnace chamber 30, a molded body 14 and a plurality of heating elements 28 are arranged. Around the molded body 14, an internal partition wall 16 that partitions the molded body 14 and the heating element 28 is provided.
　成形体１４は、成形工程ＳＴ４を行うための装置であり、成形炉室３０に設けられている。成形体１４は、溶解装置２００から流れてくる溶融ガラスを、オーバーフローダウンドロー法によりシート状のガラス基板（シートガラスＧ）に成形する機能を有する。成形体１４は、垂直方向に切断した断面形状が楔形形状を有し、例えば、ジルコン、ジルコニア、ＹＰＯ４、Ａｌ２Ｏ３、ＳｉＯ２、ＳｉＣ、ＳｉＮ及びそれらの組合せからなる耐火レンガにより構成されている。成形体１４の上部には、溶解装置２００から流れてくる溶融ガラスＭＧを受け入れる溝部１８が形成されている。成形体１４の側面１４ｂは、溝部１８からオーバーフローした溶融ガラスＭＧが流下するように、鉛直方向に沿って形成されている。成形体１４の傾斜面１４ｃは、成形体１４の両側面１４ｂ，１４ｂを流下した溶融ガラスＭＧが、成形体１４の楔形形状の断面の頂点である最下端部１４ｄで合流するように、側面１４ｂに対して傾斜している。 The molded body 14 is an apparatus for performing the molding step ST4 and is provided in the molding furnace chamber 30. The formed body 14 has a function of forming the molten glass flowing from the melting apparatus 200 into a sheet-like glass substrate (sheet glass G) by an overflow down draw method. The molded body 14 has a wedge-shaped cross-sectional shape cut in the vertical direction, and is composed of, for example, refractory bricks made of zircon, zirconia, YPO 4 , Al 2 O 3 , SiO 2 , SiC, SiN, and combinations thereof. ing. A groove portion 18 that receives the molten glass MG flowing from the melting device 200 is formed in the upper portion of the molded body 14. The side surface 14b of the molded body 14 is formed along the vertical direction so that the molten glass MG overflowed from the groove 18 flows down. The inclined surface 14c of the molded body 14 has a side surface 14b so that the molten glass MG flowing down the both side surfaces 14b, 14b of the molded body 14 joins at the lowermost end portion 14d, which is the apex of the wedge-shaped cross section of the molded body 14. It is inclined with respect to.
　内部隔壁１６は、発熱体２８と成形体１４との間に配置され、成形体１４を取り囲むように、成形体１４の周囲に配置されている。内部隔壁１６はＳｉＣ焼結体で構成されており、より詳しくは、高密度の焼結ＳｉＣの板で構成されている。内部隔壁１６は、ＳｉＣの含有率が９５ｗｔ％（重量％）以上のＳｉＣ焼結体で構成されていることが好ましい。また、内部隔壁１６の温度の均一性を高める観点から、熱伝導率が１２００℃で２０Ｗ／（ｍ・Ｋ）以上、より好ましくは２５Ｗ／（ｍ・Ｋ）以上、さらに好ましくは３０Ｗ／（ｍ・Ｋ）以上であるＳｉＣ焼結体を用いることが好ましい。上記熱伝導率の上限は、例えば４９０Ｗ／（ｍ・Ｋ）とする。また、内部隔壁１６の酸化膨張を防止する観点から、内部隔壁１６を構成するＳｉＣ焼結体の開気孔率は１％以下とする。ＳｉＣ焼結体の開気孔率は、好ましくは０．８％以下であり、さらに好ましくは、０．６％以下である。また、ＳｉＣ焼結体の開気孔率は、例えば０％超とする。ここで、開気孔率とは、試料の外形容積を１とした場合、この中に占める開気孔部分の容積の百分比であり、例えば、ＪＩＳ　Ｒ　１６３４：１９９８に規定される測定方法により測定することができる。 The inner partition wall 16 is disposed between the heating element 28 and the molded body 14 and is disposed around the molded body 14 so as to surround the molded body 14. The internal partition 16 is made of a SiC sintered body, and more specifically, is made of a high-density sintered SiC plate. The internal partition 16 is preferably composed of a SiC sintered body having a SiC content of 95 wt% (wt%) or more. Further, from the viewpoint of improving the temperature uniformity of the internal partition wall 16, the thermal conductivity at 1200 ° C. is 20 W / (m · K) or more, more preferably 25 W / (m · K) or more, and further preferably 30 W / (m. -It is preferable to use the SiC sintered compact which is more than K). The upper limit of the thermal conductivity is, for example, 490 W / (m · K). Further, from the viewpoint of preventing the oxidative expansion of the internal partition wall 16, the open porosity of the SiC sintered body constituting the internal partition wall 16 is set to 1% or less. The open porosity of the SiC sintered body is preferably 0.8% or less, and more preferably 0.6% or less. Further, the open porosity of the SiC sintered body is, for example, more than 0%. Here, the open porosity is a percentage of the volume of the open pore portion in the sample when the outer volume of the sample is 1, and is measured by a measurement method defined in JIS R 1634: 1998, for example. Can do.
　炉壁２４と内部隔壁１６との間には、炉壁２４と内部隔壁１６との間の空間を横方向に仕切る水平隔壁２６が設けられている。水平隔壁２６は、成形炉室３０の炉壁２４と内部隔壁１６との間の空間を、上下に隣接した複数の空間に仕切る板状の部材であり、例えば、ジルコン、ジルコニア、ＹＰＯ４、Ａｌ２Ｏ３、ＳｉＯ２、ＳｉＣ、ＳｉＮ及びそれらの組合せからなる断熱部材である。水平隔壁２６によって区画された小空間にはそれぞれ発熱体２８が配置されている。成形炉室３０を複数の空間に仕切り、仕切った各空間の温度を発熱体２８により制御できればよく、水平隔壁２６を配置する位置、数は、任意である。例えば、一定間隔ごと、隣り合う発熱体２８からの距離が一定になる位置等に水平隔壁２６を配置する。また、水平隔壁２６の厚さは、任意に設定でき、例えば、内部隔壁１６の厚さと同一、炉壁２４の厚さと同一にすることもできる。水平隔壁２６と内部隔壁１６とが同一の材料である場合、厚さを同一にすることにより、水平隔壁２６及び内部隔壁１６が伝える伝熱量を等しくし、溶融ガラスＭＧを幅方向に均一に加熱することができる。また、内部隔壁１６及び水平隔壁２６にＳｉＣ焼結体を用いる場合、溶融ガラスＭＧを幅方向に均一に加熱するために、溶融ガラスＭＧにより近い位置に設けられた内部隔壁１６の熱伝導率を、水平隔壁２６の熱伝導率より高くすることもできる。また、内部隔壁１６の開気孔率を、水平隔壁２６の開気孔率より低くすることもできる。また、成形体１４の最下端部１４ｄに位置する溶融ガラスＭＧの温度の均一性を高めるために、最下端部１４ｄに対向する位置にある内部隔壁１６の熱伝導率を、両側面１４ｂ，１４ｂに対向する位置にある内部隔壁１６の熱伝導率より高くすることもできる。また、最下端部１４ｄに対向する位置にある内部隔壁１６の開気孔率を、両側面１４ｂ，１４ｂに対向する位置にある内部隔壁１６の開気孔率より低くすることもできる。 A horizontal partition wall 26 is provided between the furnace wall 24 and the internal partition wall 16 to partition the space between the furnace wall 24 and the internal partition wall 16 in the lateral direction. The horizontal partition wall 26 is a plate-like member that partitions the space between the furnace wall 24 of the molding furnace chamber 30 and the internal partition wall 16 into a plurality of vertically adjacent spaces. For example, zircon, zirconia, YPO 4 , Al It is a heat insulating member made of 2 O 3 , SiO 2 , SiC, SiN and combinations thereof. A heating element 28 is disposed in each of the small spaces partitioned by the horizontal partition wall 26. The molding furnace chamber 30 may be partitioned into a plurality of spaces, and the temperature of each partitioned space may be controlled by the heating element 28, and the position and number of the horizontal partition walls 26 are arbitrary. For example, the horizontal partition wall 26 is disposed at a position where the distance from the adjacent heating element 28 is constant at regular intervals. Moreover, the thickness of the horizontal partition 26 can be set arbitrarily, for example, it can be made the same as the thickness of the internal partition 16 and the thickness of the furnace wall 24. When the horizontal partition wall 26 and the internal partition wall 16 are made of the same material, the heat transfer amount transmitted by the horizontal partition wall 26 and the internal partition wall 16 is made equal by making the thickness the same, and the molten glass MG is uniformly heated in the width direction. can do. Moreover, when using a SiC sintered compact for the internal partition 16 and the horizontal partition 26, in order to heat the molten glass MG uniformly in the width direction, the thermal conductivity of the internal partition 16 provided at a position closer to the molten glass MG is set. The thermal conductivity of the horizontal partition wall 26 can be made higher. Further, the open porosity of the internal partition wall 16 can be made lower than the open porosity of the horizontal partition wall 26. Further, in order to improve the uniformity of the temperature of the molten glass MG located at the lowermost end portion 14d of the molded body 14, the thermal conductivity of the internal partition wall 16 located at the position facing the lowermost end portion 14d is set to both side surfaces 14b, 14b. It is also possible to make it higher than the thermal conductivity of the internal partition wall 16 at the position opposite to. Further, the open porosity of the internal partition wall 16 at the position facing the lowermost end portion 14d can be made lower than the open porosity of the internal partition wall 16 at the position facing both side surfaces 14b, 14b.
　発熱体２８は、例えば、抵抗加熱、誘電加熱、マイクロ波加熱、誘導加熱によって発熱するシーズヒータ、カートリッジヒータ、あるいはセラミックヒータ等から構成され、発熱量（温度）を任意に調整できる。成形炉室３０に配置された各発熱体２８は、発熱量を独立して制御でき、例えば、熔融ガラスＭＧが成形炉室３０内を下方に進むときに、成形体１４の溝部１８、両側面１４ｂ，１４ｂ、傾斜面１４ｃ、最下端部１４ｄへと順次温度が下がるように、温度勾配を形成することができる。すなわち、内部隔壁１６の成形体１４の側に面する壁面の温度は、熔融ガラスＭＧの流れる方向に進むにしたがって、温度が下がるように、複数の発熱体２８の発熱量は調整される、ことが好ましい。 The heating element 28 is composed of, for example, a sheathed heater, a cartridge heater, or a ceramic heater that generates heat by resistance heating, dielectric heating, microwave heating, induction heating, etc., and the amount of generated heat (temperature) can be arbitrarily adjusted. Each heating element 28 disposed in the molding furnace chamber 30 can independently control the amount of heat generated. For example, when the molten glass MG travels downward in the molding furnace chamber 30, the grooves 18 and both side surfaces of the molding body 14. A temperature gradient can be formed so that the temperature sequentially decreases toward 14b, 14b, the inclined surface 14c, and the lowermost end portion 14d. That is, the amount of heat generated by the plurality of heating elements 28 is adjusted so that the temperature of the wall surface facing the molded body 14 of the internal partition wall 16 decreases as the molten glass MG flows. Is preferred.
　仕切り部材２０は、成形体１４の最下端部１４ｄの近傍に配置される板状の部材であり、例えば、ジルコン、ジルコニア、ＹＰＯ４、Ａｌ２Ｏ３、ＳｉＯ２、ＳｉＣ、ＳｉＮ及びそれらの組合せからなる断熱部材である。仕切り部材２０は、先端が互いに対向するように一対設けられている。仕切り部材２０は、成形体１４の最下端部１４ｄから流下していくシートガラスＧの厚み方向の両側に、水平となるように配置されている。仕切り部材２０は、シートガラスが通過する隙間を残してその上下の雰囲気を仕切り、断熱することにより、仕切り部材２０の上側から下側への熱の移動を抑制している。仕切り部材２０の下方には、冷却ローラ２２が配置されている。 The partition member 20 is a plate-like member disposed in the vicinity of the lowermost end portion 14d of the forming body 14, for example, zircon, zirconia, YPO 4, Al 2 O 3 , SiO 2, SiC, SiN and a combination thereof It is the heat insulation member which consists of. A pair of partition members 20 are provided such that the ends thereof are opposed to each other. The partition member 20 is disposed so as to be horizontal on both sides in the thickness direction of the sheet glass G flowing down from the lowermost end portion 14d of the molded body 14. The partition member 20 suppresses the movement of heat from the upper side to the lower side of the partition member 20 by partitioning and insulating the upper and lower atmospheres leaving a gap through which the sheet glass passes. A cooling roller 22 is disposed below the partition member 20.
　冷却ローラ２２は、仕切り部材２０の下方に位置する炉室に配置されている。また、冷却ローラ２２は、シートガラスＧの厚み方向の両側に、且つ、その幅方向の両端部分に対向するように配置されている。冷却ローラ２２は、例えば、内部に通された空冷管により空冷されている。シートガラスＧは、冷却ローラ２２を通る際に、空冷された冷却ローラ２２に接触する幅方向の両端部分の表裏面が冷却される。これにより、当該両端部の粘度は、所定値以上、例えば、１０９．０ｐｏｉｓｅ(１０ｐｏｉｓｅ＝１Ｐａ・秒)以上に調整される。冷却ローラ２２は、駆動モータによる駆動力が伝達されることにより、シートガラスＧを下方に引っ張る。 The cooling roller 22 is disposed in a furnace chamber located below the partition member 20. Moreover, the cooling roller 22 is arrange | positioned so as to oppose the both ends of the thickness direction of the sheet glass G, and the both ends of the width direction. The cooling roller 22 is air-cooled by, for example, an air-cooling tube passed through the inside. When the sheet glass G passes through the cooling roller 22, the front and back surfaces of both end portions in the width direction in contact with the air-cooled cooling roller 22 are cooled. Thereby, the viscosity of the both ends is adjusted to a predetermined value or more, for example, 10 9.0 poise (10 poise = 1 Pa · sec) or more. The cooling roller 22 pulls the sheet glass G downward by transmitting the driving force of the driving motor.
　成形炉室３０の下方には、冷却工程ＳＴ５を行う不図示の徐冷炉室が設けられている。徐冷炉室は、シートガラスＧの流れに沿って複数の炉室に区画され、シートガラスＧの流れに沿って複数の引張りローラが設けられている。引張りローラはモータにより駆動され、シードガラスＧを下方に引張りながら搬送する。また、各炉室には、シートガラスＧの周囲の雰囲気の温度を調節するためのヒータが設けられている。このヒータを用いてシートガラスＧの周囲の雰囲気の温度を制御することにより、シートガラスＧの温度を制御し、シートガラスＧの板厚偏差、反り、歪、を低減する温度プロファイルに従って、シートガラスＧを徐冷する。 Below the forming furnace chamber 30, a slow cooling furnace chamber (not shown) for performing the cooling step ST5 is provided. The slow cooling furnace chamber is partitioned into a plurality of furnace chambers along the flow of the sheet glass G, and a plurality of tension rollers are provided along the flow of the sheet glass G. The pulling roller is driven by a motor and conveys the seed glass G while pulling it downward. Each furnace chamber is provided with a heater for adjusting the temperature of the atmosphere around the sheet glass G. By controlling the temperature of the atmosphere around the sheet glass G using this heater, the temperature of the sheet glass G is controlled, and the sheet glass is subjected to a temperature profile that reduces the thickness deviation, warpage, and distortion of the sheet glass G. G is gradually cooled.
　切断工程ＳＴ６は、不図示の切断装置によって行う。切断装置は、徐冷炉室の下方に配置されている。切断装置は、成形装置３００において流下するシートガラスＧを、その長手面に対して垂直な方向に切断する装置である。シート状のシートガラスＧは、切断装置によって切断されることで、所定の長さを有する複数の素板となる。素板はさらに切断され、端面加工、洗浄、検査を経て梱包され、ガラス基板として出荷される。 The cutting step ST6 is performed by a cutting device (not shown). The cutting device is disposed below the slow cooling furnace chamber. The cutting device is a device that cuts the sheet glass G flowing down in the forming device 300 in a direction perpendicular to the longitudinal surface thereof. The sheet-like sheet glass G becomes a plurality of base plates having a predetermined length by being cut by a cutting device. The base plate is further cut, packaged through end face processing, cleaning, and inspection, and shipped as a glass substrate.
　次に、本実施形態の作用について説明する。
　成形工程ＳＴ４において、成形体１４の溝部１８を流れた溶融ガラスＭＧは、当該溝部１８の頂部においてオーバーフローし、成形体１４の両側面１４ｂ，１４ｂに沿って流下する。そして、成形体１４の両側面１４ｂ，１４ｂを沿って流下した溶融ガラスＧは、傾斜面１４ｃ，１４ｃを経て、成形体１４の最下端部１４ｄで合流してシートガラスＧとなる。シートガラスＧは、一対の仕切り部材２０，２０の間のスリット状の隙間を通して、成形炉室３０の下方の徐冷炉室に供給される。 Next, the operation of this embodiment will be described.
In the molding step ST4, the molten glass MG that has flowed through the groove 18 of the molded body 14 overflows at the top of the groove 18 and flows down along both side surfaces 14b and 14b of the molded body 14. And the molten glass G which flowed down along the both side surfaces 14b and 14b of the molded object 14 merges in the lowest end part 14d of the molded object 14 via the inclined surfaces 14c and 14c, and becomes the sheet glass G. The sheet glass G is supplied to a slow cooling furnace chamber below the forming furnace chamber 30 through a slit-like gap between the pair of partition members 20 and 20.
　このとき、発熱体２８により内部隔壁１６が加熱され、加熱された内部隔壁１６と成形体１４を流れる溶融ガラスＭＧとの間で熱交換が行われ、溶融ガラスＭＧは冷却される。 At this time, the internal partition 16 is heated by the heating element 28, heat exchange is performed between the heated internal partition 16 and the molten glass MG flowing through the molded body 14, and the molten glass MG is cooled.
　成形炉室３０内の酸素を含む雰囲気は、１０００℃以上、例えば１２００℃程度の温度に保たれるが、内部隔壁１６がこのような高い温度で酸素を含む雰囲気に曝されることで、内部隔壁１６を構成するＳｉＣ焼結体は酸素に接する部分から酸化されＳｉＯ２に変化する。このとき、ＳｉＣ焼結体の開気孔率が１％よりも大きいと、表面からだけでなく内部からも酸化が進行しやすくなる。内部酸化が進行した場所では体積が増すため、変形や更には割れにつながることになる。特に、高温粘性が高い、無アルカリガラスやアルカリ金属を微量含んだアルカリ微量含有ガラスを成形炉室３０で形成する場合、成形炉室３０内の温度を、従来より高温に保つ必要がある。成形炉室３０内の温度を従来より高くすると、内部隔壁１６の変形が促進され、割れにつながる。ＳｉＣ焼結体は、高温に強く、また、耐熱性や耐酸化性に優れる材料である。しかし、ＳｉＣ焼結体が酸素と反応する酸化開始温度は、約７００℃であり、この温度以上になると酸化が始まり、変形や更には割れにつながる。成形炉室３０内の温度は、上述したように１０００℃以上であるため、ＳｉＣ焼結体は、成形炉室３０内において酸化され易い。 The atmosphere containing oxygen in the forming furnace chamber 30 is maintained at a temperature of 1000 ° C. or more, for example, about 1200 ° C., but the internal partition wall 16 is exposed to the atmosphere containing oxygen at such a high temperature, The SiC sintered body constituting the partition 16 is oxidized from the portion in contact with oxygen and changed to SiO 2 . At this time, if the open porosity of the SiC sintered body is larger than 1%, the oxidation tends to proceed not only from the surface but also from the inside. In a place where internal oxidation has progressed, the volume increases, leading to deformation and even cracking. In particular, when forming the alkali-free glass or alkali-containing glass containing a trace amount of alkali metal in the molding furnace chamber 30 with high high-temperature viscosity, it is necessary to keep the temperature in the molding furnace chamber 30 higher than before. When the temperature in the molding furnace chamber 30 is higher than the conventional temperature, the deformation of the internal partition wall 16 is promoted, leading to cracking. The SiC sintered body is a material that is resistant to high temperatures and excellent in heat resistance and oxidation resistance. However, the oxidation start temperature at which the SiC sintered body reacts with oxygen is about 700 ° C., and when this temperature is exceeded, oxidation starts, leading to deformation and further cracking. Since the temperature in the molding furnace chamber 30 is 1000 ° C. or higher as described above, the SiC sintered body is easily oxidized in the molding furnace chamber 30.
　本実施形態においては、内部隔壁１６に開気孔率が１％以下であるＳｉＣ焼結体を用いる。そのため、酸素を含む高温の雰囲気と接するのは表面のみとなり、組織内部にＳｉＣの酸化が進行することを抑制することができる。これにより、内部隔壁１６の内部酸化による異常膨張が抑制され、変形、表面の亀裂、割れの発生を抑制することができる。したがって、内部隔壁１６の均熱効果が低下することを防止して、ガラス基板の品質を向上させることができる。また、内部隔壁１６の寿命を延長し、ガラス基板の生産性を改善することができる。また、ＳｉＣ焼結体が酸化すると、酸化物であるＳｉＯ２がＳｉＣ焼結体表面を完全に覆って酸化に対する保護膜となるため、内部隔壁１６の内部の酸化を抑制することができる。 In the present embodiment, a SiC sintered body having an open porosity of 1% or less is used for the internal partition wall 16. Therefore, only the surface comes into contact with the high temperature atmosphere containing oxygen, and the progress of SiC oxidation inside the tissue can be suppressed. Thereby, abnormal expansion due to internal oxidation of the internal partition wall 16 is suppressed, and deformation, surface cracks, and generation of cracks can be suppressed. Therefore, it is possible to prevent the soaking effect of the internal partition wall 16 from being lowered, and to improve the quality of the glass substrate. Moreover, the lifetime of the internal partition 16 can be extended and the productivity of the glass substrate can be improved. Further, when the SiC sintered body is oxidized, the oxide SiO 2 completely covers the surface of the SiC sintered body and becomes a protective film against oxidation, so that the internal oxidation of the internal partition wall 16 can be suppressed.
　また、成形体１４上の溶融ガラスＭＧは、発熱体２８と直接熱交換するのではなく、内部隔壁１６を介する。したがって、各発熱体２８の温度が場所によりばらついていても、内部隔壁１６の均熱効果により成形体１４上の溶融ガラスＭＧの温度にはほとんどその温度ばらつきの影響を及ぼすことがない。図４は、発熱体２８周辺の温度分布を説明する図であり、溶融ガラスＭＧと内部隔壁１６と発熱体１８を、図３の上方から下方に見た図である。発熱体２８が発熱すると、発熱体２８から出た熱は発熱体２８を中心として球状に広がっていき、内部隔壁１６と水平隔壁２６と炉壁２４で囲まれた小空間では、発熱体２８を中心とした球状の温度分布が形成される。球状に広がった熱が内部隔壁１６に達すると、内部隔壁１６に熱が吸収され、内部隔壁１６には熱が蓄積される。内部隔壁１６には均熱効果があるため、内部隔壁１６に蓄積された熱は、内部隔壁１６の側壁に沿って平面状に放出される。このため、内部隔壁１６内の空間では、内部隔壁１６に沿って、少なくとも溶融ガラスＭＧの幅方向に沿ってほぼ一定の温度分布が形成される。この内部隔壁１６に沿ったほぼ一定の温度分布により、溶融ガラスＭＧの温度が溶融ガラスＭＧの幅方向で均一になり、成形体１４の最下端部１４ｄにおいて、シートガラスＧの温度が例えば約１１５０℃で幅方向に均一になる。 Further, the molten glass MG on the molded body 14 does not directly exchange heat with the heating element 28 but passes through the internal partition wall 16. Therefore, even if the temperature of each heating element 28 varies from place to place, the temperature variation of the molten glass MG on the molded body 14 is hardly affected by the soaking effect of the internal partition wall 16. FIG. 4 is a view for explaining the temperature distribution around the heating element 28, and is a view of the molten glass MG, the internal partition wall 16, and the heating element 18 as viewed from above in FIG. When the heating element 28 generates heat, the heat generated from the heating element 28 spreads in a spherical shape around the heating element 28, and in the small space surrounded by the internal partition wall 16, the horizontal partition wall 26, and the furnace wall 24, A spherical temperature distribution with a center is formed. When the heat spread in a spherical shape reaches the inner partition wall 16, the heat is absorbed by the inner partition wall 16, and heat is accumulated in the inner partition wall 16. Since the internal partition wall 16 has a soaking effect, the heat accumulated in the internal partition wall 16 is released in a planar shape along the side wall of the internal partition wall 16. For this reason, in the space in the internal partition 16, a substantially constant temperature distribution is formed along the internal partition 16 along at least the width direction of the molten glass MG. Due to the substantially constant temperature distribution along the internal partition wall 16, the temperature of the molten glass MG becomes uniform in the width direction of the molten glass MG, and the temperature of the sheet glass G is, for example, about 1150 at the lowermost end portion 14 d of the molded body 14. It becomes uniform in the width direction at ℃.
　また、本実施形態の内部隔壁１６は、熱伝導率が１２００℃で２０Ｗ／（ｍ・Ｋ）以上であり、より好ましくは２５Ｗ／（ｍ・Ｋ）以上、さらに好ましくは３０Ｗ／（ｍ・Ｋ）以上である。したがって、各発熱体２８の温度が場所によりばらついていても、内部隔壁１６の温度は溶融ガラスＭＧの幅方向で場所によるばらつきが少なくなり、温度が溶融ガラスＭＧの幅方向で均一になりやすい。すなわち、内部隔壁１６の均熱効果を向上させ、成形体１４を流れる溶融ガラスＭＧの温度を溶融ガラスＭＧの幅方向でより均一に冷却して、ガラス基板の品質を向上させることができる。 Further, the internal partition 16 of the present embodiment has a thermal conductivity of 20 W / (m · K) or more at 1200 ° C., more preferably 25 W / (m · K) or more, and further preferably 30 W / (m · K). ) That's it. Therefore, even if the temperature of each heating element 28 varies from place to place, the temperature of the internal partition wall 16 is less varied depending on the place in the width direction of the molten glass MG, and the temperature tends to be uniform in the width direction of the molten glass MG. That is, the soaking effect of the internal partition 16 can be improved, and the temperature of the molten glass MG flowing through the molded body 14 can be cooled more uniformly in the width direction of the molten glass MG, thereby improving the quality of the glass substrate.
　成形炉室３０内の炉壁２４と内部隔壁１６との間の雰囲気は、発熱体２８によって所要温度に保たれる。一方、成形体１４を流れる溶融ガラスＭＧは流下に伴い、徐々に温度を下げる必要がある。 The atmosphere between the furnace wall 24 and the internal partition wall 16 in the molding furnace chamber 30 is maintained at a required temperature by the heating element 28. On the other hand, it is necessary to gradually lower the temperature of the molten glass MG flowing through the molded body 14 as it flows down.
　本実施形態では、成形炉室３０の炉壁２４と内部隔壁１６との間に、成形炉室３０を上下に隣接する複数の空間に仕切る水平隔壁２６を設けている。水平隔壁２６で仕切られた複数の空間には複数の発熱体２８が設けられ、各発熱体２８は、発熱量を独立して制御できる。水平隔壁２６は、断熱性の高い材料、例えば、内部隔壁１６に比べて断熱性の高い材料で構成されている。これにより、成形体の表面を流下する溶融ガラスの対向面である内部隔壁面の温度を流下方向で任意に変えることができるようになり、溶融ガラスに対して、溶融ガラスの流下方向で所望の温度差をつけることができ、ガラス基板の品質を向上させることができる。なお、溶融ガラスに流下方向で所望の温度差をつけるために、成形炉室３０に設置された測温抵抗体、熱電対等の温度センサ（図示せず）が計測した温度に基づいて、発熱体２８の発熱量を調整することもできる。例えば、温度センサで計測した温度が、成形体１４の両側面１４ｂ，１４ｂと、傾斜面１４ｃとで同一である場合には、両側面１４ｂ，１４ｂに対向する位置にある発熱体２８の発熱量を増加する、または、傾斜面１４ｃに対向する位置になる発熱体２８の発熱量を抑制することにより、両側面１４ｂ，１４ｂ及び傾斜面１４ｃを流れる熔融ガラスＭＧにおいて流下方向で温度差をつけることができる。 In this embodiment, a horizontal partition wall 26 that partitions the molding furnace chamber 30 into a plurality of vertically adjacent spaces is provided between the furnace wall 24 of the molding furnace chamber 30 and the internal partition wall 16. A plurality of heating elements 28 are provided in the plurality of spaces partitioned by the horizontal partition walls 26, and each heating element 28 can independently control the amount of heat generation. The horizontal partition wall 26 is made of a material having a high heat insulating property, for example, a material having a high heat insulating property compared to the internal partition wall 16. As a result, the temperature of the inner partition wall surface, which is the facing surface of the molten glass flowing down the surface of the molded body, can be arbitrarily changed in the flowing direction. A temperature difference can be given and the quality of a glass substrate can be improved. In addition, in order to make a desired temperature difference in the flow direction in the molten glass, a heating element based on a temperature measured by a temperature sensor (not shown) such as a resistance temperature detector or a thermocouple installed in the molding furnace chamber 30. The amount of heat generated by 28 can be adjusted. For example, when the temperature measured by the temperature sensor is the same on both side surfaces 14b and 14b of the molded body 14 and the inclined surface 14c, the amount of heat generated by the heating element 28 at a position facing the both side surfaces 14b and 14b. Or by suppressing the amount of heat generated by the heating element 28 at a position facing the inclined surface 14c, a temperature difference is caused in the flow direction in the molten glass MG flowing through the side surfaces 14b, 14b and the inclined surface 14c. Can do.
　本実施形態の製造方法は、成形炉内を、高温に保つ必要がある場合に適している。具体的には、成形炉内が１０００℃以上である場合に適しており、１２００℃以上である場合にさらに適しており、１３００℃以上である場合に特に適している。
　高温粘性が大きいガラス（熔融ガラス）を用いてガラス基板を製造する場合には、成形炉内を高温に保つ必要があるので、本実施形態は、高温粘性が大きいガラス（溶融ガラス）を用いてガラス基板を製造する際に適している。具体的には、本実施形態では、ガラス（溶融ガラス）の粘度が１０５ｐｏｉｓｅのとき、１０００℃以上であるガラス（溶融ガラス）を用いてガラス基板を製造する際に適している。また、粘度が１０５ｐｏｉｓｅのときの溶融ガラスの温度の上限は、例えば１７００℃である。 The manufacturing method of this embodiment is suitable when the inside of the molding furnace needs to be kept at a high temperature. Specifically, it is suitable when the inside of the molding furnace is 1000 ° C. or higher, more suitable when it is 1200 ° C. or higher, and particularly suitable when it is 1300 ° C. or higher.
When manufacturing a glass substrate using glass (molten glass) having a high high temperature viscosity, it is necessary to keep the inside of the molding furnace at a high temperature, so this embodiment uses glass (molten glass) having a high high temperature viscosity. Suitable for manufacturing glass substrates. Specifically, in this embodiment, when the viscosity of the glass (molten glass) is 10 5 poise, it is suitable for manufacturing a glass substrate using glass (molten glass) that is 1000 ° C. or higher. Moreover, the upper limit of the temperature of a molten glass when a viscosity is 10 < 5 > poise is 1700 degreeC, for example.
　また、無アルカリガラスやアルカリ金属を微量含んだアルカリ微量含有ガラスは、高温粘性が高いので、本実施形態は、無アルカリガラスやアルカリ微量含有ガラスから構成されるガラス基板を製造する場合に適している。無アルカリガラスの一例として、質量％で表示して、以下の組成範囲のガラス基板が挙げられる。
ＳｉＯ２：５０～７０％、
Ａｌ２Ｏ３：０～２５％、
Ｂ２Ｏ３：1～１５％、
ＭｇＯ：０～１０％、
ＣａＯ：０～２０％、
ＳｒＯ：０～２０％、
ＢａＯ：０～１０％、
ＲＯ：５～３０％（ただし、ＲはＭｇ、Ｃａ、Ｓｒ及びＢａの合量)、を含有する無アルカリガラス。
　なお、上述したように、ガラス基板はアルカリ金属を微量含んだアルカリ微量含有ガラスであってもよい。アルカリ金属を含有させる場合、Ｒ’２Ｏの合計が０．１０％以上０．５％以下、好ましくは０．２０％以上０．５％以下(ただし、Ｒ’はＬｉ、Ｎａ及びＫから選ばれる少なくとも１種であり、ガラス基板が含有するものである)含むことが好ましい。勿論、Ｒ’２Ｏの合計が０．１０％未満でもよい。すなわち、本発明は、無アルカリガラスやアルカリ微量のガラス基板が使用されるフラットパネルディスプレイを製造する場合に適している。 In addition, since alkali-free glass or alkali-containing glass containing a trace amount of alkali metal has high viscosity at high temperature, this embodiment is suitable for manufacturing a glass substrate composed of alkali-free glass or alkali-containing glass. Yes. As an example of the alkali-free glass, a glass substrate having the following composition range is shown by mass%.
SiO 2 : 50 to 70%,
Al 2 O 3 : 0 to 25%,
B 2 O 3 : 1 to 15%,
MgO: 0 to 10%,
CaO: 0-20%,
SrO: 0 to 20%,
BaO: 0 to 10%,
RO: Alkali-free glass containing 5 to 30% (where R is the total amount of Mg, Ca, Sr and Ba).
As described above, the glass substrate may be a glass containing a trace amount of alkali metal containing a trace amount of alkali metal. When an alkali metal is contained, the total of R ′ 2 O is 0.10% or more and 0.5% or less, preferably 0.20% or more and 0.5% or less (where R ′ is selected from Li, Na, and K) It is preferable that the glass substrate contains at least one kind. Of course, the total of R ′ 2 O may be less than 0.10%. That is, the present invention is suitable for manufacturing a flat panel display using an alkali-free glass or a glass substrate with a small amount of alkali.
　以上、本発明の実施形態について詳細に説明したが、本発明は上記実施形態に限定されず、本発明の主旨を逸脱しない範囲において、種々の改良や変更してもよい。 As mentioned above, although embodiment of this invention was described in detail, this invention is not limited to the said embodiment, You may change and change variously in the range which does not deviate from the main point of this invention.
［実施例］
　上述の実施形態において説明したガラス基板製造装置を用いて、ガラス基板を製造した。内部隔壁として、ＳｉＣの含有率が９９ｗｔ％であり、熱伝導率が１２００℃で２５Ｗ／（ｍ・Ｋ）であり、開気孔率が１％である高密度の焼結ＳｉＣを用いた。
　内部隔壁の使用を開始して２年以内では、内部隔壁の酸化膨張により変形する事例は見られず、ガラス基板を安定して製造することができた。
　上述の実施形態において説明したガラス基板の製造装置を用いて、ガラス基板を製造した。内部隔壁として、ＳｉＣの含有率が９８ｗｔ％であり、熱伝導率が１２００℃で３０Ｗ／（ｍ・Ｋ）であり、開気孔率が０．６％である高密度の焼結ＳｉＣを用いた。
　上述の実施形態において説明したガラス基板の製造装置を用いて、ガラス基板を製造した。内部隔壁として、ＳｉＣの含有率が９５ｗｔ％であり、熱伝導率が１２００℃で３５Ｗ／ｍＫであり、開気孔率が０．５％である高密度の焼結ＳｉＣを用いた。
　内部隔壁の使用を開始して３年以内では、内部隔壁の酸化膨張により変形する事例は見られず、ガラス基板を安定して製造することができた。
［比較例］
　内部隔壁としてＳｉＣの含有率が７４ｗｔ％であり、熱伝導率が３５０℃で１２．６Ｗ／（ｍ・Ｋ）であり、開気孔率が１４．６％である窒ケイ素結合ＳｉＣを用いた以外は、実施例と同様にガラス基板を製造した。
　内部隔壁の使用を開始してから約１８ヶ月後に、内部隔壁の酸化膨張による変形が許容できないほど大きくなり、内部隔壁の交換が必要になるものが３０％程度の頻度で発生した。
　以上の結果から、上記実施形態の効果は明確である。 [Example]
The glass substrate was manufactured using the glass substrate manufacturing apparatus demonstrated in the above-mentioned embodiment. As the inner partition wall, high-density sintered SiC having a SiC content of 99 wt%, a thermal conductivity of 25 W / (m · K) at 1200 ° C., and an open porosity of 1% was used.
Within 2 years since the use of the internal partition wall was started, there was no case of deformation due to oxidative expansion of the internal partition wall, and the glass substrate could be stably manufactured.
A glass substrate was manufactured using the glass substrate manufacturing apparatus described in the above embodiment. As the inner partition wall, high-density sintered SiC having a SiC content of 98 wt%, a thermal conductivity of 30 W / (m · K) at 1200 ° C., and an open porosity of 0.6% was used. .
A glass substrate was manufactured using the glass substrate manufacturing apparatus described in the above embodiment. As the internal partition wall, high-density sintered SiC having a SiC content of 95 wt%, a thermal conductivity of 35 W / mK at 1200 ° C., and an open porosity of 0.5% was used.
Within 3 years from the start of use of the internal partition wall, there was no case of deformation due to oxidative expansion of the internal partition wall, and the glass substrate could be stably manufactured.
[Comparative example]
Other than using silicon nitride-bonded SiC having an SiC content of 74 wt% as an internal partition, a thermal conductivity of 12.6 W / (m · K) at 350 ° C., and an open porosity of 14.6% Manufactured the glass substrate like the Example.
About 18 months after the start of use of the internal partition wall, deformation due to oxidative expansion of the internal partition wall became unacceptably large, and it was necessary to replace the internal partition wall with a frequency of about 30%.
From the above results, the effect of the embodiment is clear.
１４　成形体
１６　内部隔壁
２４　炉壁
２６　水平隔壁
２８　発熱体
３０　成形炉室
ＭＧ　溶融ガラス
Ｇ　シートガラス 14 Molded body 16 Internal partition wall 24 Furnace wall 26 Horizontal partition wall 28 Heating element 30 Molding furnace chamber MG Molten glass G Sheet glass

Claims (6)

  1. 　ダウンドロー法により溶融ガラスをシートガラスに成形する工程を有するガラス基板の製造方法であって、
    　成形炉室に、発熱体と、前記成形体と、前記発熱体と前記成形体とを仕切る内部隔壁と、を設け、
    　前記内部隔壁に開気孔率が１％以下のＳｉＣ焼結体を用い、
    　前記発熱体により前記内部隔壁を介して前記成形体を流れる前記溶融ガラスを加熱することを特徴とするガラス基板の製造方法。     A method for producing a glass substrate having a step of forming molten glass into sheet glass by a downdraw method,
    In the molding furnace chamber, provided with a heating element, the molded body, and an internal partition that partitions the heating element and the molded body,
    An SiC sintered body having an open porosity of 1% or less is used for the internal partition wall,
    A method for producing a glass substrate, comprising: heating the molten glass flowing through the molded body through the internal partition by the heating element.
  2. 　前記内部隔壁は、熱伝導率が１２００℃で２０Ｗ／（ｍ・Ｋ）以上である、請求項１に記載のガラス基板の製造方法。 The method for producing a glass substrate according to claim 1, wherein the internal partition wall has a thermal conductivity of 20 W / (m · K) or more at 1200 ° C.
  3. 　前記溶融ガラスは、１０５ｐｏｉｓｅの粘度のとき、１０００℃以上である、請求項１又は２に記載のガラス基板の製造方法。 The said molten glass is a manufacturing method of the glass substrate of Claim 1 or 2 which is 1000 degreeC or more when the viscosity of 10 < 5 > poise.
  4. 　前記ガラス基板は、無アルカリガラス又はアルカリ微量含有ガラスである、請求項1～３のいずれか１項に記載のガラス基板の製造方法。 The method for producing a glass substrate according to any one of claims 1 to 3, wherein the glass substrate is an alkali-free glass or a glass containing a trace amount of alkali.
  5. 　前記成形炉室の炉壁と前記内部隔壁との間の空間を、水平隔壁によって上下に隣接する複数の小空間に区画し、
    　前記小空間の各々に前記発熱体を配置する、請求項１～４のいずれか１項に記載のガラス基板の製造方法。     The space between the furnace wall of the molding furnace chamber and the internal partition is partitioned into a plurality of small spaces adjacent to each other by a horizontal partition,
    The method for manufacturing a glass substrate according to any one of claims 1 to 4, wherein the heating element is disposed in each of the small spaces.
  6. 　前記内部隔壁の前記成形体の側に面する壁面の温度は、前記熔融ガラスの流れる方向に進むにしたがって、温度が下がるように、前記発熱体の発熱量を調整する、請求項５に記載のガラス基板の製造方法。 The temperature of the wall surface facing the molded body side of the internal partition wall is adjusted as the amount of heat generated by the heating element so that the temperature decreases as the molten glass proceeds in the flowing direction. A method for producing a glass substrate.
PCT/JP2014/052211 2013-01-31 2014-01-31 Method for manufacturing glass substrate WO2014119708A1 (en)

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CN107602153A (en) * 2017-08-03 2018-01-19 彩虹（合肥）液晶玻璃有限公司 A kind of method that SiC plate surfaces oxide layer quickly thickens
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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010527891A (en) * 2007-05-18 2010-08-19 コーニング インコーポレイテッド Method and apparatus for minimizing inclusions in glass manufacturing processes
WO2011145387A1 (en) * 2010-05-21 2011-11-24 日本碍子株式会社 Si-SiC-BASED COMPOSITE MATERIAL AND PROCESS FOR PRODUCTION THEREOF, HONEYCOMB STRUCTURE, HEAT-CONDUCTIVE MATERIAL, AND HEAT EXCHANGER
JP2013001608A (en) * 2011-06-17 2013-01-07 Nippon Electric Glass Co Ltd Production apparatus of glass, and method for producing glass using the same

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7799375B2 (en) * 2004-06-30 2010-09-21 Poco Graphite, Inc. Process for the manufacturing of dense silicon carbide
US8490432B2 (en) * 2009-11-30 2013-07-23 Corning Incorporated Method and apparatus for making a glass sheet with controlled heating
TWI535672B (en) * 2010-05-28 2016-06-01 康寧公司 Composite isopipe
TWI454435B (en) * 2011-03-31 2014-10-01 Avanstrate Inc Glass plate manufacturing method
CN102674661A (en) * 2012-03-31 2012-09-19 彩虹显示器件股份有限公司 Temperature control method of glass plate shaping zone of overflow drop-down device

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010527891A (en) * 2007-05-18 2010-08-19 コーニング インコーポレイテッド Method and apparatus for minimizing inclusions in glass manufacturing processes
WO2011145387A1 (en) * 2010-05-21 2011-11-24 日本碍子株式会社 Si-SiC-BASED COMPOSITE MATERIAL AND PROCESS FOR PRODUCTION THEREOF, HONEYCOMB STRUCTURE, HEAT-CONDUCTIVE MATERIAL, AND HEAT EXCHANGER
JP2013001608A (en) * 2011-06-17 2013-01-07 Nippon Electric Glass Co Ltd Production apparatus of glass, and method for producing glass using the same

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