abstract |
An alkali free glass is characterized in including 50 to 70% of SiO2, 9 to 15% of Al2O3, 11 to 20% of B2O3, 8 to 12% of CaO based on mol% as composition of the glass. A value of mole ratio of (MgO+CaO+SrO+BaO)/Al2O3 is 0.8 to 1.2, a density is 2.37 g/cm<SP>3</SP> or less, a temperature at 10<SP>2.5</SP>dPa.s is 1600 DEG C. |