Avanstrate Inc.

Manabu Ichikawa

Akihiro Koyama

Satoshi Ami

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 SiOand AlO, comprising 0% or more to less than 3% BOand from 5 to 14% BaO in mass %, and substantially devoiding SbO, wherein the devitrification temperature is 1235&#xb0; C. or lower and the strain point is 720&#xb0; C. or higher. Alternatively, this glass substrate for a display is made of a glass comprising SiOand AlO, comprising 0% or more to less than 3% BO, 1.8% or more MgO, and from 5 to 14% BaO in mass %, and substantially devoiding SbO, wherein (SiO+MgO+CaO)&#x2014;(AlO+SrO+BaO) is less than 42%, the devitrification temperature is 1260&#xb0; C. or lower, and the strain point is 720&#xb0; C. or higher. This method for producing said glass substrate for a display comprises: a melting step for melting, by using at least direct electrical heating, a glass material prepared to have a predetermined composition; a forming step for forming, into a flat glass sheet, the molten glass that has been melted in the melting step; and an annealing step for 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.

Glass substrate for display and method for producing same

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 SiOand AlO, comprising 0% or more to less than 4% BOin mass %, and substantially devoiding SbO, wherein 3&#xd7;BaO/(MgO+CaO+SrO) is 5 or less, MgO/(CaO+SrO) is 0.36 or greater, the devitrification temperature is 1235&#xb0; C. or lower, and the strain point is 700&#xb0; 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.

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 SiO, 3-25 mass % of AlO, 3-15 mass % of BO, 3-20 mass % of RO, wherein RO is total amount of MgO, CaO, SrO, and BaO, 0.01-0.8 mass % of RO, wherein RO is total amount of LiO, NaO, and KO, and 0-0.3 mass % of SbO, and substantially does not comprise AsO, wherein the mass ratio CaO/RO is equal to or greater than 0.65, the mass ratio (SiO+AlO)/BOis in a range of 7-30, and the mass ratio (SiO+AlO)/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.

Glass substrate for flat panel display and method for manufacturing same

A flat panel display glass substrate according to the present invention includes a glass comprising, as expressed in mol %, 55-80% SiO, 3-20% AlO, 3-15% BO, 3-25% RO (the total amount of MgO, CaO, SrO, and BaO), and substantially no AsO, and SbO. The devitrification temperature of the glass is 1250&#xb0; 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&#xb0; C./min and at 550&#xb0; 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}&#xd7;10.

Glass substrate for flat panel display and manufacturing method thereof

A glass substrate for p-Si TFT flat panel displays that is composed of a glass comprising 52-78 mass % of SiO, 3-25 mass % of AlO, 3-15 mass % of BO, 3-25 mass % of RO, wherein RO is total amount of MgO, CaO, SrO, and BaO, 0.01-1 mass % of FeO, and 0-0.3 mass % of SbO, and substantially not comprising AsO, the glass having a mass ratio (SiO+AlO)/BOin a range of 7-30 and a mass ratio (SiO+AlO)/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.

A flat panel display glass substrate includes a glass comprising, in mol %, 55-80% SiO, 3-20% AlO, 3-15% BO, and 3-25% RO (the total amount of MgO, CaO, SrO, and BaO). The contents in mol % of SiO, AlO, and BOsatisfy a relationship (SiO+AlO)/(BO)=7.5-17. The strain point of the glass is 665&#xb0; C. or more. The devitrification temperature of the glass is 1250&#xb0; 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&#xb0; C./min and at 550&#xb0; 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}&#xd7;10.

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 SiO, 3-25 mass % of AlO, 3-15 mass % of BO, 3-25 mass % of RO, wherein RO is total amount of MgO, CaO, SrO, and BaO, 0.01-1 mass % of FeO, and 0-0.3 mass % of SbO, and substantially not comprising AsO, the glass having a mass ratio (SiO+AlO)/BOin a range of 7-30 and a mass ratio (SiO+AlO)/RO equal to or greater than 6. The present 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.

A flat panel display glass substrate according to the present invention includes a glass comprising, as expressed in mol %, 55-80% SiO, 3-20% AlO, 3-15% BO, 3-25% RO (the total amount of MgO, CaO, SrO, and BaO), and substantially no AsOand SbO. The devitrification temperature of the glass is 1250&#xb0; 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&#xb0; C./min and at 550&#xb0; 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}&#xd7;10.

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Yokkaichi, Japan

Manabu Ichikawa