| 摘要 |
<p>PURPOSE: An alkali metal oxide-free glass containing SiO2, B2O3, Al2O3, MgO, CaO, SrO, and BaO is provided to ensure light weight and proper fusibility. CONSTITUTION: An alkali metal oxide-free glass contains 60-72% of SiO2, 1-4% of B2O3, 4-12% of Al2O3, 9-14% of MgO, 6-9% of CaO, 1-6% of SrO, and 3-8% of BaO. The alkali metal oxide-free glass contains 19-25% of MgO+CaO+SrO+BaO. A method for manufacturing the glass comprises: a step of heating at 1500-1600 deg. C and fusing(S120); and a step of molding the fused glass(S130). The density and coefficient of thermal expansion of the alkalimetal oxide-free glass are 2.6g/cm^3 or less and 3.0×10^-6-4.6×10^-6/K, respectively. The alkali metal oxide-free glass has a viscosity of 10^2dPas at 1550 deg. C or less and a viscosity of 10^4dPas at 1220 deg. C or less. [Reference numerals] (S110) Combining glass ingredients; (S120) Fusing; (S130) Molding; (S140) Annealing</p> |
