Abstract: Provided are: a glass substrate that achieves a high strain point while having a low devitrification temperature; and a method for producing said glass substrate. This glass substrate for a display is made of a glass comprising SiO2 and Al2O3, comprising 0% or more to less than 3% B2O3 and from 5 to 14% BaO in mass %, and substantially devoiding Sb2O3, wherein the devitrification temperature is 1235° C. or lower and the strain point is 720° C. or higher. Alternatively, this glass substrate for a display is made of a glass comprising SiO2 and Al2O3, comprising 0% or more to less than 3% B2O3, 1.8% or more MgO, and from 5 to 14% BaO in mass %, and substantially devoiding Sb2O3, wherein (SiO2+MgO+CaO)—(Al2O3+SrO+BaO) is less than 42%, the devitrification temperature is 1260° C. or lower, and the strain point is 720° C. or higher.

Abstract: A glass substrate that achieves a high strain point while having a low devitrification temperature; and a method for producing the glass substrate. This glass substrate for a display is made of a glass comprising SiO2 and Al2O3, comprising 0% or more to less than 4% B2O3 in mass %, and substantially devoiding Sb2O3, wherein 3×BaO/(MgO+CaO+SrO) is 5 or less, MgO/(CaO+SrO) is 0.36 or greater, the devitrification temperature is 1235° C. or lower, and the strain point is 700° C. or higher. The method comprises: melting, by using at least direct electrical heating, a glass material prepared to have a predetermined composition; forming, into a flat glass sheet, the molten glass that has been melted in the melting step; and annealing the flat glass sheet, wherein a condition for cooling the flat glass sheet is controlled so as to reduce the heat shrinkage rate of the flat glass sheet.

Abstract: A method for manufacturing a glass substrate comprises a surface processing step of performing surface processing for forming unevenness on a glass surface. In the surface processing step, protruded portions having a height of 1nm or more from an average line of a roughness curve are dispersedly formed on the glass surface. In the surface processing step, the surface processing is performed such that a protruded portion area ratio is 0.5 to 10%. The protruded portion area ratio is a ratio of an area of the protruded portions with respect to an area of any rectangular region. The rectangular region has a square shape with a side length of 1 ?m. In the surface processing step, in a case where the rectangular region is equally divided into at least one hundred divided regions having a square shape, the surface processing is performed such that a protruded portion content ratio is 80% or more.

Abstract: Provided are: a glass substrate that achieves a high strain point while having a low devitrification temperature; and a method for producing said glass substrate. This glass substrate for a display is made of a glass comprising SiO2 and Al2O3, comprising 0% or more to less than 3% B2O3 and from 5 to 14% BaO in mass %, and substantially devoiding Sb2O3, wherein the devitrification temperature is 1235° C. or lower and the strain point is 720° C. or higher. Alternatively, this glass substrate for a display is made of a glass comprising SiO2 and Al2O3, comprising 0% or more to less than 3% B2O3, 1.8% or more MgO, and from 5 to 14% BaO in mass %, and substantially devoiding Sb2O3, wherein (SiO2+MgO+CaO)—(Al2O3+SrO+BaO) is less than 42%, the devitrification temperature is 1260° C. or lower, and the strain point is 720° C. or higher.

Abstract: A glass substrate that achieves a high strain point while having a low devitrification temperature; and a method for producing the glass substrate. This glass substrate for a display is made of a glass comprising SiO2 and Al2O3, comprising 0% or more to less than 4% B2O3 in mass %, and substantially devoiding Sb2O3, wherein 3×BaO/(MgO+CaO+SrO) is 5 or less, MgO/(CaO+SrO) is 0.36 or greater, the devitrification temperature is 1235° C. or lower, and the strain point is 700° C. or higher. The method comprises: melting, by using at least direct electrical heating, a glass material prepared to have a predetermined composition; forming, into a flat glass sheet, the molten glass that has been melted in the melting step; and annealing the flat glass sheet, wherein a condition for cooling the flat glass sheet is controlled so as to reduce the heat shrinkage rate of the flat glass sheet.

Abstract: The method for producing a glass sheet by down-drawing includes an air pressure controlling step of controlling the air pressure of a furnace outside space formed between a furnace and a covering part that covers the furnace, the furnace including a forming furnace and a lehr, a melting step of melting glass raw materials to form molten glass, a supplying step of supplying the molten glass to a forming cell disposed inside the forming furnace, a forming step of forming a glass sheet by allowing the molten glass to flow down the forming cell, an annealing step of cooling the glass sheet while allowing the glass sheet to flow in one direction in the lehr, and a cutting step of cutting the glass sheet that has been cooled. In the air pressure controlling step, air pressure is controlled such that the air pressure is higher, inside the furnace outside space, at a position more toward the upstream side of the flow direction of the glass sheet.

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 method for manufacturing a glass substrate comprises a surface processing step of performing surface processing for forming unevenness on a glass surface. In the surface processing step, protruded portions having a height of 1 nm or more from an average line of a roughness curve are dispersedly formed on the glass surface. In the surface processing step, the surface processing is performed such that a protruded portion area ratio is 0.5 to 10%. The protruded portion area ratio is a ratio of an area of the protruded portions with respect to an area of any rectangular region. The rectangular region has a square shape with a side length of 1 ?m. In the surface processing step, in a case where the rectangular region is equally divided into at least one hundred divided regions having a square shape, the surface processing is performed such that a protruded portion content ratio is 80% or more.

Abstract: A glass-substrate manufacturing method which includes a forming step and a cooling step. In the forming step, a molten glass is formed into a sheet glass by a down-draw process. In the cooling step, the sheet glass is cooled. The cooling step includes first, second and third coating steps as defined herein.

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: 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-plate manufacturing method employing a down-draw process includes: a forming step of forming a sheet glass by making a molten glass flow downward along opposite side surfaces of a forming member and merge at a lower section of the forming member; and a cooling step of cooling the sheet glass while drawing the sheet glass downward with rollers. In the cooling step, an above-glass-strain-point temperature control step is performed which is a step of performing a temperature control in the width direction of the sheet glass in a temperature region ranging from the lower section of the forming member to where the temperature of the sheet glass falls below a temperature region near the glass strain point, and includes: first, second and third temperature control steps as defined herein.

Abstract: A glass substrate for p-Si TFT flat panel displays that 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. A method for manufacturing a glass substrate involves: a melting step of obtaining a molten glass by melting, by employing at least direct electrical heating, glass raw materials blended so as to provide the aforementioned 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 p-Si TFT flat panel displays that 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. A method for manufacturing a glass substrate involves: a melting step of obtaining a molten glass by melting, by employing at least direct electrical heating, glass raw materials blended so as to provide the aforementioned 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: 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 for manufacturing a glass substrate for a display includes a step of producing a glass substrate and a step of performing a surface treatment on one glass surface of major surfaces of the glass substrate to form surface unevenness. The surface treatment is performed such that protruded portions having a height of 1 nm or more from the surface roughness central plane of the surface unevenness are dispersedly provided on the glass surface after the surface treatment and the area ratio of the protruded portions with respect to the area of the glass surface is 0.5-10%. Using this glass substrate, semiconductor elements are formed on a major surface of the glass substrate opposite to the glass surface. Accordingly, a display panel is produced.

Abstract: A method for manufacturing a glass substrate for a display includes a step of producing a glass substrate and a step of performing a surface treatment on one glass surface of major surfaces of the glass substrate to form surface unevenness. The surface treatment is performed such that protruded portions having a height of 1 nm or more from the surface roughness central plane of the surface unevenness are dispersedly provided on the glass surface after the surface treatment and the area ratio of the protruded portions with respect to the area of the glass surface is 0.5-10%. Using this glass substrate, semiconductor elements are formed on a major surface of the glass substrate opposite to the glass surface. Accordingly, a display panel is produced.

Abstract: A glass-substrate manufacturing method according to an aspect of the invention is a method for manufacturing glass substrates by employing a down-draw process. In down-draw processing, a molten glass is made to overflow from a forming member and formed into a sheet glass and the sheet glass is then cooled while being drawn in a downward-flow direction. In this glass-substrate manufacturing method, after the sheet glass has separated from the forming member and when the temperature of the sheet glass is within a temperature region ranging from a temperature higher than the softening point to a temperature near the annealing point, the sheet glass is cooled by maintaining the viscosity of side sections of the sheet glass within a range of 109.0-1014.5 poise while applying a tension toward the side sections.

Abstract: A glass-substrate manufacturing method which includes a forming step and a cooling step. In the forming step, a molten glass is formed into a sheet glass by a down-draw process. In the cooling step, the sheet glass is cooled. The cooling step includes first, second and third coating steps as defined herein.

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.