To provide an alkali-free glass substrate, which has a high Young's modulus, a low linear expansion coefficient, a high strain point and a low density, does not devitrify in the float forming process and is excellent in acid resistance. An alkali-free glass substrate, which contains neither alkali c
To provide an alkali-free glass substrate, which has a high Young's modulus, a low linear expansion coefficient, a high strain point and a low density, does not devitrify in the float forming process and is excellent in acid resistance. An alkali-free glass substrate, which contains neither alkali component nor BaO and consists essentially of, as represented by mol % based on oxide, from 57.0 to 65.0% of SiO2, from 10.0 to 12.0% of Al2O3, from 6.0 to 9.0% of B2O3, from 5.0 to 10.0% of MgO, from 5.0 to 10.0% of CaO and from 2.5 to 5.5% of SrO, provided that MgO+CaO+SrO is from 16.0 to 19.0%, MgO/(MgO+CaO+SrO)≧0.40, and B2O3/(SiO2+Al2O3+B2O3)≦0.12; wherein Young's modulus ≧75 GPa; the linear expansion coefficient at from 50 to 350° C. is from 30×10−7/° C. to 40×10−7/° C.; the strain point ≧640° C.; the temperature T2 (the viscosity η satisfies log η=2)≦1,620° C.; the temperature T4 (the viscosity η satisfies log η=4)≦1,245° C.; the devitrification temperature ≦T4; and weight loss per unit area is at most 0.6 mg/cm2, when immersed in 0.1N HCl at 90° C. for 20 hours.
대표청구항▼
What is claimed is: 1. An alkali metal-free glass substrate, comprising substantially no alkali component or BaO and consisting essentially of, as represented by mol% based on oxide, from 57.0 to 65.0% of SiO2, from 10.0 to 12.0% of Al2O3, from 6.0 to 9.0% of B2O3, from 5.0 to 10.0% of MgO, from 6.
What is claimed is: 1. An alkali metal-free glass substrate, comprising substantially no alkali component or BaO and consisting essentially of, as represented by mol% based on oxide, from 57.0 to 65.0% of SiO2, from 10.0 to 12.0% of Al2O3, from 6.0 to 9.0% of B2O3, from 5.0 to 10.0% of MgO, from 6.0 to 8.0% of CaO and from 2.5 to 5.5% of SrO, provided that MgO+CaO+SrO is from 16.0 to 19.0%, MgO/(MgO+CaO+SrO)≧0.40, and B2O3/(SiO2+Al2O3)≦0.12; wherein Young's modulus ≧75 GPa; the linear expansion coefficient at from 50 to 350° C. is from 30×10−7/° C. to 40×10−7/° C.; the strain point ≧640° C.; the temperature T2 (the viscosity η satisfies logη=2) is at least 1,580° C. and at most 1,620° C.; the temperature T4 (the viscosity η satisfies logη=4) ≦1,245° C.; the devitrification temperature ≦T4; and weight loss per unit area is at most 0.2 mg/cm2, when immersed in 0.1N HCl at 90° C. for 20 hours. 2. The alkali metal-free glass substrate according to claim 1, consisting essentially of, as represented by mol% based on oxide, from 60.0 to 65.0% of SiO2, from 10.0 to 12.0% of Al2O3, from 6.0 to 9.0% of B2O3, from 5.5 to 8.5% of MgO, from 5.0 to 10.0% of CaO and from 2.5 to 5.5% of SrO, provided that MgO+CaO+SrO is from 16.0 to 18.5%, MgO/(MgO+CaO+SrO) ≧0.40, and B2O3/(SiO2+Al2O3+B2O3)≦0.12. 3. The alkali metal-free glass substrate according to claim 1, further comprising from 500 ppm to 1.0 weight % of SnO2. 4. A liquid crystal display panel, comprising at least one alkali metal-free glass substrate as defined in claim 1. 5. A method for producing an alkali metal-free glass substrate, comprising: melting a glass material so as to form a glass composition which comprises neither alkali component nor BaO and consists essentially of, as represented by mol % based on oxide, from 57.0 to 65.0% of SiO2, from 10.0 to 12.0% of Al2O3, from 6.0 to 9.0% of B2O3, from 5.0 to 10.0% of MgO, from 6.0 to 8.0% of CaO and from 2.5 to 5.5% of SrO, provided that MgO+CaO+SrO is from 16.0 to 19.0%; MgO/(MgO+CaO+SrO) ≧0.40, and B2O3/(SiO2+Al2O3+B2O3) ≦0.12, followed by forming said alkali-free glass substrate by a float process, wherein the temperature to melt the glass material is lower than 1,630° C., and the maximum temperature of the glass melt at an inlet of a float bath is 1,250° C. 6. The method for producing an alkali metal-free glass substrate according to claim 5, comprising: melting a glass material so as to form a glass composition which comprises neither alkali component nor BaO and consists essentially of, as represented by mol % based on oxide, from 60.0 to 65.0% of SiO2, from 10.0 to 12.0% of Al2O3, from 6.0 to 9.0% of B2O3, from 5.5 to 8.5% of MgO, from 5.0 to 10.0% of CaO and from 2.5 to 5.5% of SrO; MgO+CaO+SrO is from 16.0 to 18.5%, MgO/(MgO+CaO+SrO) ≧0.40, and B2O3/(SiO2+Al2O3+B2O3) ≦0.12, followed by forming by a float process, wherein the temperature to melt the glass material is lower than 1,620° C., and the maximum temperature of the glass melt at an inlet of a float bath is 1,245° C. 7. The method for producing an alkali metal-free glass substrate according to claim 5, wherein the glass material comprises from 0.1 to 1.0 weight % of SnO2. 8. The method for producing an alkali metal-free glass substrate according to claim 5, wherein the glass material further comprises from 0.1 to 1.0 weight % of SnO2, and the method comprises heating the glass material at a temperature of from 1,450 to 1,580° C. to form molten glass, and subsequent to forming the molten glass, heating the molten glass at a temperature of at least 1,500° C. and lower than 1,630° C. to remove bubbles, wherein the temperature of the molten glass to remove bubbles is higher by at least 30° C. than the temperature of the molten glass to be formed.
Peters, James Carl; Serrano, Juan Camilo; Li, Hong; Richards, Cheryl A.; Parks, Steven Joel, Low density and high strength fiber glass for reinforcement applications.
※ AI-Helper는 부적절한 답변을 할 수 있습니다.