Abstract: Provided is a non-alkali glass having a strain point of 680° C. or higher, having an average thermal expansion coefficient of from 30×10?7/° C. to 45×10?7/° C. at from 50° C. to 350° C., containing, indicated by mass % on the basis of oxides: SiO2: 54% to 66%, Al2O3: 10% to 27%, B2O3: 0.2% to 5.5%, MgO: 0% to 10%, CaO: 0% to 15%, SrO: 0% to 15%, BaO: 0% to 15%, and MgO+CaO+SrO+BaO: 8% to 25%, containing 600 mass ppm or less of Na2O, and satisfying a mass ratio (Na2O/B2O3) between Na2O and B2O3 being from 0.001 to 0.3.

Abstract: The present invention relates to an alkali-free glass substrate, in which when two arbitrary sites in one main surface thereof are selected, an absolute value of a difference between a thermal shrinkage ratio in an arbitrary direction at one site and a thermal shrinkage ratio in a direction orthogonal to the arbitrary direction at another site is 2 ppm or less, provided that the thermal shrinkage ratio is calculated by measuring a deformation amount in a measuring direction of the glass substrate between before and after a heat treatment of raising a temperature from normal temperature to 600° C. at 100° C./hour, holding the glass substrate at 600° C. for 80 minutes, and lowering the temperature from 600° C. to normal temperature at 100° C./hour.

Abstract: The present invention relates to an alkali-free glass substrate, having a strain point of 680° C. or higher, a Young's modulus of 78 GPa or greater, an UV transmittance at a wavelength of 300 nm of from 40% to 85% in terms of 0.5 mm thickness, an in-plane distribution of the UV transmittance at a wavelength of 300 nm in a G6-sized substrate of 1% or less in terms of 0.5 mm thickness, an average cooling rate around the glass transition point obtained according to a rate cooling method of 400° C./min or lower, and an in-plane distribution of the average cooling rate of 40° C./min or less.

Abstract: Provided is a non-alkali glass having a strain point of 680° C. or higher, having an average thermal expansion coefficient of from 30×10?7/° C. to 45×10?7/° C. at from 50° C. to 350° C., containing, indicated by mass % on the basis of oxides: SiO2: 54% to 66%, Al2O3: 10% to 27%, B2O3: 0.2% to 5.5%, MgO: 0% to 10%, CaO: 0% to 15%, SrO: 0% to 15%, BaO: 0% to 15%, and MgO+CaO+SrO+BaO: 8% to 25%, containing 600 mass ppm or less of Na2O, and satisfying a mass ratio (Na2O/B2O3) between Na2O and B2O3 being from 0.001 to 0.3.

Abstract: The present invention relates to an alkali-free glass substrate, having a strain point of 680° C. or higher, a Young's modulus of 78 GPa or greater, an UV transmittance at a wavelength of 300 nm of from 40% to 85% in terms of 0.5 mm thickness, an in-plane distribution of the UV transmittance at a wavelength of 300 nm in a G6-sized substrate of 1% or less in terms of 0.5 mm thickness, an average cooling rate around the glass transition point obtained according to a rate cooling method of 400° C./min or lower, and an in-plane distribution of the average cooling rate of 40° C./min or less.

Abstract: The present invention relates to an alkali-free glass having a strain point of from 680 to 735° C., an average thermal expansion coefficient at from 50 to 350° C. of from 30×10?7 to 43×10?7/° C., and a specific gravity of 2.60 or less, and containing, indicated by mol % on the basis of oxides, SiO2 65 to 69%, Al2O3 11.5 to 14%, B2O3 3 to 6.5%, MgO 1 to 5%, CaO 7.5 to 12%, SrO 0 to 1%, BaO 0.5 to 6%, and ZrO2 0 to 2%.

Abstract: The present invention relates to an alkali-free float sheet glass having a glass transition point of from 730 to 850° C. and a temperature T4 of from 1220 to 1350° C., and containing, indicated by mass % on the basis of oxides: SiO2: 57 to 65%, Al2O3: 14 to 23%, B2O3: 0 to 5.5%, MgO: 1 to 8.5%, CaO: 3 to 12%, SrO: 0 to 10%, and BaO: 0 to 5%, satisfying MgO+CaO+SrO+BaO of from 12 to 23%, containing F in an amount of from 0.1 to 0.35 mass %, containing Cu in an amount of from 0.3 to 3 mass ppm, containing Cl in an amount of from 0 to 0.05 mass %, and satisfying a ratio f1/f2 of from 0.05 to 0.5.

Abstract: The present invention relates to a non-alkali glass having a strain point of from 710° C. to lower than 725° C., an average thermal expansion coefficient at from 50 to 300° C. of from 30×10?7 to 43×10?7/° C., a temperature T2 at which glass viscosity reaches 102 dPa·s of 1710° C. or lower, a temperature T4 at which the glass viscosity reaches 104 dPa·s of 1320° C. or lower, and containing, indicated by mol % on the basis of oxides, SiO2 66 to 70, Al2O3 12 to 14, B2O3 exceeding 0 to 1.5, MgO exceeding 9.5 to 13 (or 5 to 9.5), CaO 4 to 9 (or 4 to 11), SrO 0.5 to 4.5, BaO 0 to 0.5 and ZrO 0 to 2.

Abstract: The present invention relates to a non-alkali glass substrate, having a strain point of 685° C. or higher and 750° C. or lower, an average thermal expansion coefficient at 50 to 350° C. of from 35×10?7 to 43×10?7/° C., a specific gravity of from 2.50 to 2.80, a photoelastic constant of 25 nm/MPa/cm or more and less than 29 nm/MPa/cm, and a temperature (T4) at which viscosity reaches 104 dPa·s of 1,250° C. or higher and lower than 1,350° C., and having a prescribed composition.

Abstract: The present invention relates to a non-alkali glass having a strain point of from 710° C. to lower than 725° C., an average thermal expansion coefficient at from 50 to 300° C. of from 30×10?7 to 43×10?7/° C., a temperature T2 at which glass viscosity reaches 102 dPa·s of 1710° C. or lower, a temperature T4 at which the glass viscosity reaches 104 dPd·s of 1320° C. or lower, and containing, indicated by mol % on the basis of oxides, SiO2 66 to 70, Al2O3 12 to 14, B2O3 exceeding 0 to 1.5, MgO exceeding 9.5 to 13 (or 5 to 9.5), CaO 4 to 9 (or 4 to 11), SrO 0.5 to 4.5, BaO 0 to 0.5 and ZrO 0 to 2.

Abstract: The present invention relates to a non-alkali glass having a strain point of from 710° C. to lower than 725° C., an average thermal expansion coefficient at from 50 to 300° C. of from 30×10?7 to 43×10?7/° C., a temperature T2 at which glass viscosity reaches 102 dPa·s of 1710° C. or lower, a temperature T4 at which the glass viscosity reaches 104 dPa·s of 1320° C. or lower, and containing, indicated by mol % on the basis of oxides, SiO2 66 to 70, Al2O3 12 to 14, B2O3 exceeding 0 to 1.5, MgO exceeding 9.5 to 13 (or 5 to 9.5), CaO 4 to 9 (or 4 to 11), SrO 0.5 to 4.5, BaO 0 to 0.5 and ZrO 0 to 2.

Abstract: The present invention relates to a non-alkali glass substrate, having a strain point of 685° C. or higher and 750° C. or lower, an average thermal expansion coefficient at 50 to 350° C. of from 35×10?7 to 43×10?7/° C., a specific gravity of from 2.50 to 2.80, a photoelastic constant of 25 nm/MPa/cm or more and less than 29 nm/MPa/cm, and a temperature (T4) at which viscosity reaches 104 dPa·s of 1,250° C. or higher and lower than 1,350° C., and having a prescribed composition.

Abstract: The present invention relates to an alkali-free glass having a strain point of from 680 to 735° C., an average thermal expansion coefficient at from 50 to 350° C. of from 30×10?7 to 43×10?7/° C., and a specific gravity of 2.60 or less, and containing, indicated by mol % on the basis of oxides, SiO2 65 to 69%, Al2O3 11.5 to 14%, B2O3 3 to 6.5%, MgO 1 to 5%, CaO 7.5 to 12%, SrO 0 to 1%, BaO 0.5 to 6%, and ZrO2 0 to 2%.

Abstract: The present invention relates to an alkali-free glass having a strain point of 680 to 735° C., an average thermal expansion coefficient at from 50 to 350° C. of from 30×10?7 to 43×10?7/° C., a temperature T2 at which glass viscosity reaches 102 dPa.s of 1,710° C. or lower, and a temperature T4 at which the glass viscosity reaches 104 dPa.s of 1,310° C. or lower, and containing, indicated by mol % on the basis of oxides, SiO2 63 to 74, Al2O3 11.5 to 16, B2O3 exceeding 1.5 to 5, MgO 5.5 to 13, CaO 1.5 to 12, SrO 1.5 to 9, BaO 0 to 1, and ZrO2 0 to 2, in which MgO+CaO+SrO+BaO is from 15.5 to 21, MgO/(MgO+CaO+SrO+BaO) is 0.35 or more, CaO/(MgO+CaO+SrO+BaO) is 0.50 or less, and SrO/(MgO+CaO+SrO+BaO) is 0.50 or less.

Abstract: The present invention relates to an alkali-free glass having a strain point of 710° C. or higher, an average thermal expansion coefficient at from 50 to 350° C. of from 30×10?7 to 43×10?7/° C., a temperature T2 at which glass viscosity reaches 102 dPa·s of 1,710° C. or lower, and a temperature T4 at which the glass viscosity reaches 104 dPa·s of 1,320° C. or lower, containing, indicated by % by mass on the basis of oxides: SiO2 58.5 to 67.5, Al2O3 18 to 24, B2O3 0 to 1.7, MgO 6.0 to 8.5, CaO 3.0 to 8.5, SrO 0.5 to 7.5, BaO 0 to 2.5, and ZrO2 0 to 4.0, containing 0 to 0.35% by mass of Cl, 0.01 to 0.15% by mass of F, and 0.01 to 0.3% by mass of SnO2, and having a ?-OH value of the glass of from 0.15 to 0.60 mm?1.

Abstract: The present invention relates to an alkali-free glass substrate with a thickness of 0.4 mm or less, which has been reduced in thickness by 5 ?m or more by a hydrofluoric acid (HF) etching treatment, in which the alkali-free glass substrate contains an alkali-free glass described below, and the alkali-free glass substrate after reduced in thickness has a specific modulus of 32 MNm/kg or more and a photoelastic constant of 31 nm/MPa/cm or less, the alkali-free glass having a strain point of 710° C. or higher, an average thermal expansion coefficient at 50 to 350° C. of from 30×10?7to 43×10?7/° C., a temperature T2 at which a glass viscosity reaches 102 dPa·s of 1710° C. or lower, a temperature T4 at which the glass viscosity reaches 104 dPa·s of 1320° C. or lower.

Abstract: The present invention relates to a non-alkali glass having a strain point of 710° C. or higher, an average thermal expansion coefficient at from 50 to 300° C. of from 30×10?7 to 43×10?7/° C., a temperature T2 at which glass viscosity reaches 102 dPa·s of 1,710° C. or lower, a temperature T4 at which the glass viscosity reaches 104 dPa·s of 1,320° C. or lower, containing, indicated by percentage by mass on the basis of oxides, SiO2 58.5 to 67.5, Al2O3 18 to 24, B2O3 0 to 1.7, MgO 6.0 to 8.5, CaO 3.0 to 8.5, SrO 0.5 to 7.5, BaO 0 to 2.5 and ZrO2 0 to 4.0, containing Cl in an amount of from 0.15 to 0.35% by mass, F in an amount of from 0.01 to 0.15% by mass and SO3 in an amount of from 1 to 25 ppm and having a ?-OH value of the glass of from 0.15 to 0.45 mm?1, in which (MgO/40.3)+(CaO/56.1)+(SrO/103.6)+(BaO/153.3) is from 0.27 to 0.35, (MgO/40.3)/((MgO/40.3)+(CaO/56.1)+(SrO/103.6)+(BaO/153.3)) is 0.40 or more, (MgO/40.3)/((MgO/40.3)+(CaO/56.1)) is 0.40 or more, and (MgO/40.3)/((MgO/40.3)+(SrO/103.6)) is 0.

Abstract: The present invention relates to a non-alkali glass having a strain point of from 710° C. to lower than 725° C., an average thermal expansion coefficient at from 50 to 300° C. of from 30×107 to 43×10?7/° C., a temperature T2 at which glass viscosity reaches 102dPa.s of 1710° C. or lower, a temperature T4 at which the glass viscosity reaches 104 dPd.s of 1320° C. or lower, and containing, indicated by mol % on the basis of oxides, SiO2 66 to 70, Al2O3 12 to 14, B2O3 exceeding 0 to 1.5, MgO exceeding 9.5 to 13 (or 5 to 9.5), CaO 4 to 9 (or 4 to 11), SrO 0.5 to 4.5, BaO 0 to 0.5 and ZrO 0 to 2.

Abstract: The present invention relates to a production method for a non-alkali glass, containing putting glass raw materials in a melting furnace, heating to a temperature of 1,350 to 1,750° C. to prepare a molten glass, and forming the molten glass into a sheet shape by float method, in which the heating in the melting furnace concurrently utilizes heating by combustion flame of burners and electrical heating of the molten glass by heating electrodes arranged so as to be dipped in the molten glass in the melting furnace, and in which when electrical resistivity at 1,350° C. of the molten glass is represented by Rg (?cm) and electrical resistivity at 1,350° C. of a refractory constituting the melting furnace is represented by Rb (?cm), the glass raw materials and the refractory are selected so as to achieve Rb>Rg.

Abstract: A method for manufacturing an alkali-free glass includes heating the glass raw material at a temperature of 1,400 to 1,800° C. in a melting furnace to thereby prepare a molten glass, and forming the molten glass into a sheet shape, wherein heating by combustion flame of a burner and electrical heating of the molten glass by a heating electrode arranged so as to be dipped in the molten glass in the melting furnace are used in combination in the heating in the melting furnace, and when an electrical resistivity of the molten glass at 1,400° C. is Rg (?cm) and an electrical resistivity of a refractory constituting the melting furnace at 1,400° C. is Rb (?cm), the glass raw material and the refractory are selected so as to satisfy Rb>Rg.