Abstract: Provided is a glass composition suitable for a glass substrate for a flat panel display such as a liquid crystal display. This glass composition has high thermal stability, and is substantially free of BaO but has a low devitrification temperature. It is suitable for the production of a glass substrate by a downdraw process. This glass composition contains, in terms of mass %; 54 to 62% of SiO2; 4 to 11% of B2O3; 15 to 20% of Al2O3; 2 to 5% of MgO; 0 to 7% of CaO; 0 to 13.5% of SrO; 0 to 1% of K2O; 0 to 1% of SnO2; and 0 to 0.2% of Fe2O3, and is substantially free of BaO. In this glass composition, the total content of alkaline earth metal oxides (MgO+CaO+SrO) is 10 to 18.5 mass %. The devitrification temperature of the glass composition is 1200° C. or lower.

Abstract: A method of manufacturing glass comprises a stirring step in which molten glass MG is stirred. The stirring step comprises a first stirring step and a second stirring step. In the first stirring step, the molten glass MG is stirred while being directed upward from below in a first stirred tank 100a. In the second stirring step, the molten glass MG stirred in the first stirring step is stirred while being directed downward from above in a second stirred tank 100b. The first stirred tank 100a has a first discharge pipe 110a capable of discharging the molten glass MG from the bottom of a first chamber 101a. The second stirred tank 100b has a second discharge pipe 110b capable of discharging the molten glass MG from the liquid level LL of the molten glass MG in a second chamber 101b.

Abstract: A method of manufacturing a glass sheet includes creating split flows of molten glass in a forming body (10) and causing the molten glass to flow down, subsequently merging the flows at a merging point to form a glass sheet G and causing the glass sheet to flow downward in the vertical direction. A plurality of chambers (42b, 42c, . . . ) separated by heat-insulating plates (40a, 40b, . . . ) in the direction of movement of the glass sheet G are provided. A heater (60a, 60b, . . . ) is provided for each of the chambers (42b, 42c, . . . ) so that the temperature decreases in the direction of movement. The heat-insulating plates (40a, 40b, . . . ) are disposed facing the glass sheet G, and facing surfaces of the heat-insulating plates (40a, 40b, . . . ) are shaped so as to correspond to a sheet thickness variation of the glass sheet G.

Abstract: A glass composition which is reduced in the amount of residual bubbles and is produced using smaller amounts of an environmentally unfriendly component such as arsenic oxide and antimony oxide. This glass composition comprises, in terms of mass %; 40-70% SiO2; 5-20% B2O3; 10-25% Al2O3; 0-10% MgO; 0-20% CaO; 0-20% SrO; 0-10% BaO; 0.001-0.5% Li2O; 0.01-0.5% Na2O; 0.002-0.5% K2O; and 0-1.0%, excluding 0%, Cl.

Abstract: A flat panel display glass substrate includes a glass comprising, in mol %, 55-80% SiO2, 3-20% Al2O3, 3-15% B2O3, and 3-25% RO (the total amount of MgO, CaO, SrO, and BaO). The contents in mol % of SiO2, Al2O3, and B2O3 satisfy a relationship (SiO2+Al2O3)/(B2O3)=7.5-17. The strain point of the glass is 665° C. or more. The devitrification temperature of the glass is 1250° C. or less. The substrate has a heat shrinkage rate of 75 ppm or less. The rate of heat shrinkage is calculated from the amount of shrinkage of the substrate measured after a heat treatment which is performed at a rising and falling temperature rate of 10° C./min and at 550° C. for 2 hours by the rate of heat shrinkage (ppm)={the amount of shrinkage of the substrate after the heat treatment/the length of the substrate before the heat treatment}×106.

Abstract: A substrate for p-Si TFT flat panel displays made of a glass having a high low-temperature-viscosity characteristic temperature and manufactured while avoiding erosion/wear of a melting tank during melting through direct electrical heating. The glass substrate comprises 52-78 mass % of SiO2, 3-25 mass % of Al2O3, 3-15 mass % of B2O3, 3-20 mass % of RO, wherein RO is total amount of MgO, CaO, SrO, and BaO, 0.01-0.8 mass % of R2O, wherein R2O is total amount of Li2O, Na2O, and K2O, and 0-0.3 mass % of Sb2O3, and substantially does not comprise As2O3, wherein the mass ratio CaO/RO is equal to or greater than 0.65, the mass ratio (SiO2+Al2O3)/B2O3 is in a range of 7-30, and the mass ratio (SiO2+Al2O3)/RO is equal to or greater than 5. A related method involves melting glass raw materials blended to provide the glass composition; a forming step of forming the molten glass into a flat-plate glass; and an annealing step of annealing the flat-plate glass.

Abstract: A glass substrate for a display, which is formed of a glass having a light weight and having high refinability with decreasing environmental burdens, the glass comprising, by mass %, 50 to 70% of SiO2, 5 to 18% of B2O3, 10 to 25% of Al2O3, 0 to 10% of MgO, 0 to 20% of CaO, 0 to 20% of SrO, 0 to 10% of BaO, 5 to 20% of RO (in which R is at least one member selected from the group consisting of Mg, Ca, Sr and Ba), and over 0.20% but not more than 2.0% of R?2O (in which R? is at least one member selected from the group consisting of Li, Na and K), and containing, by mass %, 0.05 to 1.5% of oxide of metal that changes in valence number in a molten glass, and substantially containing none of As2O3, Sb2O3 and PbO.

Abstract: Provided are: a glass substrate for p-Si TFT flat panel displays that is composed of a glass having high characteristic temperatures in the low-temperature viscosity range, typified by the strain point and glass transition point, having a small heat shrinkage rate, and being capable of avoiding the occurrence of the problem regarding the erosion/wear of a melting tank at the time of melting through direct electrical heating; and a method for manufacturing same. The present glass substrate is composed of a glass comprising 52-78 mass % of SiO2, 3-25 mass % of Al2O3, 3-15 mass % of B2O3, 3-25 mass % of RO, wherein RO is total amount of MgO, CaO, SrO, and BaO, 0.01-1 mass % of Fe2O3, and 0-0.3 mass % of Sb2O3, and substantially not comprising As2O3, the glass having a mass ratio (SiO2+Al2O3)/B2O3 in a range of 7-30 and a mass ratio (SiO2+Al2O3)/RO equal to or greater than 6.

Abstract: A flat panel display glass substrate according to the present invention includes a glass comprising, as expressed in mol %, 55-80% SiO2, 3-20% Al2O3, 3-15% B2O3, 3-25% RO (the total amount of MgO, CaO, SrO, and BaO), and substantially no As2O3 and Sb2O3. The devitrification temperature of the glass is 1250° C. or less. The glass substrate has a heat shrinkage rate of 75 ppm or less. The heat shrinkage rate is calculated from the amount of shrinkage of the glass substrate measured after a heat treatment which is performed at a temperature rising and falling rate of 10° C./min and at 550° C. for 2 hours by the heat shrinkage rate (ppm)={the amount of shrinkage of the glass substrate after the heat treatment/the length of the glass substrate before the heat treatment}×106.

Abstract: A method of manufacturing a glass sheet according to the present invention comprises the steps of creating split flows of molten glass in a forming body 10 and causing the molten glass to flow down, subsequently merging the flows at a merging point to form a glass sheet G and causing the glass sheet to flow downward in the vertical direction. In this method of manufacturing a glass sheet, a partition member 20 is disposed facing the glass sheet G in the vicinity of a location below the forming body 10, and a facing surface of the partition member 20 is shaped so as to correspond to a sheet thickness variation of the glass sheet G, so that a gap between the glass sheet G and the partition member 20 is substantially uniform.

Abstract: A stirring device 100 comprises a chamber 101, and a stirrer 102 for stirring molten glass 7 in the chamber 101. The stirrer 102 has a shaft 105 as a rotation axis, and blades 106a-106e disposed in a plurality of tiers on a side wall of the shaft 105. The blades 106a-106e have support plates 108 and ancillary plates 109. The ancillary plates 109 create, in the molten glass 7, a flow in the radial direction of the shaft 105.

Abstract: A cover glass having a compressive-stress layer on the principal surfaces thereof, and having a glass composition containing 50% to 70% by mole of SiO2, 3% to 20% by mole of Al2O3, 5% to 25% by mole of Na2O, more than 0% by mole and less than or equal to 2.5% by mole of Li2O, 0% to 5.5% by mole of K2O, and 0% to less than 3% by mole of B2O3. Also disclosed is a method for producing a cover glass which includes: (i) preparing molten glass by melting a glass raw material; (ii) forming the prepared molten glass into a plate-like shape by a down-draw process and thereby obtaining a glass substrate; and (iii) forming a compressive-stress layer on the surface of the glass substrate.

Abstract: A method for manufacturing a glass plate includes preparing an accommodating part made of platinum or a platinum alloy, fining molten glass of a melted feedstock, stirring and homogenizing the molten glass, and supplying the molten glass to a forming apparatus. The fining the molten glass includes causing gas bubbles to float up and out from the molten glass, and causing absorption of the gas component in the molten glass and eliminating gas bubbles. The water vapor partial pressure of an atmosphere in the causing the gas bubbles is lower than the water vapor partial pressure in at least a portion of the causing the absorption of the gas component. A boundary between the causing the gas bubbles and the causing the absorption of the gas component is a temperature lower than the maximum temperature by 30° C. or more after the molten glass has reached the maximum temperature.

Abstract: A glass composition which is reduced in the amount of residual bubbles and is produced using smaller amounts of an environmentally unfriendly component such as arsenic oxide and antimony oxide. This glass composition contains, in terms of mass %: 40-70% SiO2; 5-20% B2O3; 10-25% Al2O3; 0-10% MgO; 0-20% CaO; 0-20% SrO; 0-10% BaO; 0-0.5% Li2O; 0-1.0% Na2O; 0-1.5% K2O; and 0-1.5%, excluding 0%, Cl, Li2O+Na2O+K2O exceeding 0.06%. The glass composition can be produced suitably using, for example, a chloride as part of the raw glass materials.

Abstract: Provided is a method of producing a glass, including, in order to obtain an excellent refining effect: preparing a raw glass batch including: an antimony compound containing pentavalent antimony; and an oxidizing agent (a cerium oxide, a sulfate, a nitrate); and melting the raw glass batch. In preparing the raw glass batch, it is preferable that the antimony compound be premixed with the oxidizing agent. When the nitrate is used as the oxidizing agent, the raw glass batch is prepared so as to include the antimony compound in an amount of more than 0.5 parts by mass and at most 3 parts by mass, in terms of an amount of antimony pentoxide, per 100 parts by mass of a base glass composition expressed in terms of an amount of an oxide.

Abstract: The disclosed cover glass is produced by etching a glass substrate that has been formed by a down-drawing process, and chemically strengthening the glass substrate to provide the glass substrate with a compressive-stress layer on the principal surfaces thereof. The glass substrate contains, as components thereof, 50% to 70% by mass of SiO2, 5% to 20% by mass of Al2O3, 6% to 30% by mass of Na2O, and 0% to less than 8% by mass of Li2O. The glass substrate may also contain 0% to 2.6% by mass of CaO, if necessary. The glass substrate has an etching characteristic in which the etching rate is at least 3.7 ?m/minute in an etching environment having a temperature of 22° C. and containing hydrogen fluoride with a concentration of 10% by mass.

Abstract: A glass composition which is reduced in the amount of residual bubbles and is produced using smaller amounts of an environmentally unfriendly component such as arsenic oxide and antimony oxide. This glass composition contains, in terms of mass %: 40-70% SiO2; 5-20% B2O3; 10.25% Al2O3; 0-10% MgO; 0-20% CaO; 0-20% SrO; 0-10% BaO; 0-0.5% Li2O; 0-1.0% Na2O; 0-1.5% K2O; and 0-1.5%, excluding 0%, Cl, Li2O+Na2O+K2O exceeding 0.06%. The glass composition can be produced suitably using, for example, a chloride as part of the raw glass materials.

Abstract: Provided is a cover glass having a down-drawable composition including, in mass percent: 50%-70% SiO2, 5%-20% Al2O3, 6%-20% Na2O, 0%-10% K2O, 0%-10% MgO, above 2%-20% CaO, and 0%-4.8% ZrO2 wherein, (i) 46.5%?(SiO2?½Al2O3)?59%, (ii) 0.3<CaO/RO, where RO represents a total mass percent of one or more compounds selected from the group consisting of MgO, CaO, SrO and BaO included in the glass substrate, (iii) SrO+BaO<10%, (iv) 0?(ZrO2+TiO2)/SiO2)<0.07, and (v) 0?B2O3/R12O<0.1, where R12O represents a total mass percent of one or more compounds selected from the group consisting of Li2O, Na2O and K2O included in the glass substrate.

Abstract: A glass composition which is reduced in the amount of residual bubbles and is produced using smaller amounts of an environmentally unfriendly component such as arsenic oxide and antimony oxide. This glass composition comprises, in terms of mass %; 40-70% SiO2; 5-20% B2O3; 10-25% Al2O3; 0-10% MgO; 0-20% CaO; 0-20% SrO; 0-10% BaO; 0.001-0.5% Li2O; 0.01-0.5% Na2O; 0.002-0.5% K2O; and 0-1.

Abstract: Provided is a glass composition suitable for a glass substrate for a flat panel display such as a liquid crystal display. This glass composition has high thermal stability, and is substantially free of BaO but has a low devitrification temperature. It is suitable for the production of a glass substrate by a downdraw process. This glass composition contains, in terms of mass %; 54 to 62% of SiO2; 4 to 11% of B2O3; 15 to 20% of Al2O3; 2 to 5% of MgO; 0 to 7% of CaO; 0 to 13.5% of SrO; 0 to 1% of K2O; 0 to 1% of SnO2; and 0 to 0.2% of Fe2O3, and is substantially free of BaO. In this glass composition, the total content of alkaline earth metal oxides (MgO+CaO+SrO) is 10 to 18.5 mass %. The devitrification temperature of the glass composition is 1200° C. or lower.