초록 ▼

An alkali-free glass consists essentially of, in mass percent, 58-70% SiO2, 10-19% Al2O3, 6.5-15% B2O3, 0-2% MgO, 3-12% CaO, 0.1-5% BaO, 0-4% SrO, 0.1-6% BaO+SrO, 0-5% ZnO, 5-15% MgO+CaO+BaO+SrO+ZnO, 0-5% ZrO2, 0-5% TiO2, and 0-5% P2O5. The alkali-free glass contains substantially no alkali metal ox

An alkali-free glass consists essentially of, in mass percent, 58-70% SiO2, 10-19% Al2O3, 6.5-15% B2O3, 0-2% MgO, 3-12% CaO, 0.1-5% BaO, 0-4% SrO, 0.1-6% BaO+SrO, 0-5% ZnO, 5-15% MgO+CaO+BaO+SrO+ZnO, 0-5% ZrO2, 0-5% TiO2, and 0-5% P2O5. The alkali-free glass contains substantially no alkali metal oxide and has a density of 2.45g/cm3 or less, an average coefficient of thermal expansion of 25×10?7/° C.-36×10?7/° C. within a temperature range between 30 and 380° C., and a strain point not lower than 640° C.

대표청구항 ▼

1. An alkali-free glass cons sting essentially of, in mass percent, 58-70% SiO2, 10-19% Al2O3, 6.5-15% B2O3, 0-2% MgO, greater than 8%-12% CaO, 0.1-2% BaO, 0-4% SrO, 0.1-6% BaO+SrO, 0-5% ZnO, 5-12% MgO+CaO+BaO+SrO+ZnO, 0-5% ZrO2, 0-5% TiO2, and 0-5% P2O5, containing substantially no alkali metal oxi

1. An alkali-free glass cons sting essentially of, in mass percent, 58-70% SiO2, 10-19% Al2O3, 6.5-15% B2O3, 0-2% MgO, greater than 8%-12% CaO, 0.1-2% BaO, 0-4% SrO, 0.1-6% BaO+SrO, 0-5% ZnO, 5-12% MgO+CaO+BaO+SrO+ZnO, 0-5% ZrO2, 0-5% TiO2, and 0-5% P2O5, containing substantially no alkali metal oxide, being formed into a plate shape by the down-drawn process, and having a density of 2.40 g/cm3 or less, an average coefficient of thermal expansion of 25×10?7/° C.-36×10?7/° C. within a temperature range between 30 and 380° C. and a strain point not lower than 640° C., in which the liquidus temperature is not higher than 1130° C., and the viscosity at the liquidus temperature being not lower than 105.4 dPa·s.2. An alkali-free glass according to claim 1, wherein a ratio (BaO+SrO)/BaO falls within a range of 1.1-10 in mass ratio.3. An alkali-free glass according to claim 1, wherein the erosion of the alkali-free glass is not greater than 10 μm after treatment by a 10% HCl aqueous solution under the condition of 80° C. and 24 hours and neither haze nor roughness of the alkali-free glass is confirmed by visual observation after treatment by a 10% HCl aqueous solution under the condition of 80° C. and 3 hours.4. An alkali-free glass according to claim 1, wherein the erosion of the alkali-free glass is not greater than 0.8 μm after treatment by a 130 BHF solution under the condition of 20° C. and 30 minutes and neither haze nor roughness of the alkali-free glass is confirmed by visual observation after treatment by a 63 BHF solution under the condition of 20° C. and 30 minutes.5. An alkali-free glass according to claim 1, wherein the alkali-free glass has a specific modulus not smaller than 27.5 GPa/(g·cm?3).6. An alkali-free glass according to claim 1, wherein the alkali-free glass does not contain As2O3 but contains 0.5-3.0 wt % Sb2O3+Sb2O5+SnO2+Cl.7. An alkali-free glass according to claim 1, wherein the alkali-free glass consists essentially of, in mass percent, 60-68% SiO2, 12-18% Al2O3, 7-12% B2O3, 0-2% MgO, greater than 8%-10% CaO, 0.3-2% BaO, 0.1-2.7% SrO, 0.4% or more and less than 3% BaO+SrO, 0-0.9% ZnO, 5-12% MgO+CaO+BaO+SrO+ZnO, 0-1% ZrO2, 0-1% TiO2, and 0-1% P2O5.8. A glass plate formed by a alkali-free glass consisting essentially of, in mass percent, 58-70% SiO2, 10-19% Al2O3, 6.5-15% B2O3, 0-2% MgO, greater than 8%-12% CaO, 0.1-2% BaO, 0-4% SrO, 0.1-6% BaO+SrO, 0-5% ZnO, 5-12% MgO+CaO+BaO+SrO+ZnO, 0-5% ZrO2, 0-5% TiO2, and 0-5% P2O5, containing substantially no alkali metal oxide, being formed into a plate shape by the down-draw process and having a density of 2.40 g/cm3 or less, an average coefficient of thermal expansion of 25×10?7/° C.-36×10?7/° C. within a temperature rang between 30 and 380° C., and a strain point not lower than 640° C., in which the liquidus temperature is not higher than 1130° C., and the viscosity at the liquidus temperature being not lower than 105.4 dPa·s.9. A glass plate according to claim 8, wherein the glass plate is used for a flat display.10. A glass plate according to claim 8, wherein the glass plate has a thickness of 0.6 mm or less.11. A glass plate according to claim 8, wherein the alkali-free glass consists essentially of, in mass percent, 60-68% SiO2, 12-18% Al2O3, 7-12% B2O3, 0-2% MgO, greater than 8%-10% CaO, 0.3-2% BaO, 0.1-2.7% SrO, 0.4% or more and less than 3% BaO+SrO, 0-0.9% ZnO, 5-12% MgO+CaO+BaO+SrO+ZnO, 0-1% ZrO2, 0-1% TiO2, and 0-1% P2O5.12. A polycrystal silicon TFT liquid crystal display comprising a glass plate claimed in claim 8.13. A liquid crystal display comprising a glass plate formed by an alkali-free glass consisting essentially of, in mass percent, 58-70% SiO2, 10-19% Al2O3, 6.5-15% B2O3, 0-2% MgO, greater than 8%-12% CaO, 0.1-2% BaO, 0-4% SrO, 0.1-6% BaO+SrO, 0-5% ZnO, 5-12% MgO+CaO+BaO+SrO+ZnO, 0-5% ZrO2, 0-5% TiO2, and 0-5% P2O5, containing substantially no alkali metal oxide, being formed into a plate shape by the down-draw process and having a density of 2.40 q/cm3 or less, an average coefficient of thermal expansion of 25×10?7/° C.-36×10?7/° C. within a temperature range between 30 and 380° C., and a strain point not lower than 640° C., in which the liquidus temperature is not higher than 1130° C., and the Viscosity at the liquidus temperature being not lower than 105.4 dPa·s.14. A liquid crystal display according to claim 13, wherein the alkali-free glass consists essentially of, in mass percent, 60-68% SiO2, 12-18% Al2O3, 7-12% B2O3, 0-2% MgO, greater than 8%-10% CaO, 0.3-2% BaO, 0.1-2.7% SrO, 0.4% or more and less than 3% BaO+SrO, 0-0.9% ZnO, 5-12% MgO+CaO+BaO+SrO+ZnO, 0-1% ZrO2, 0-1% TiO2, and 0-1% P2O5.