| 摘要 |
The present invention relates to a glass composition including, in terms of mol % on the basis of oxides: from 55 to 70% of SiO2, from 5 to 10% of Al2O3, from 0 to 0.5% of B2O3, from 3 to 15% of MgO, from 3 to 15% of CaO, from 2 to 10% of SrO, from 1 to 10% of BaO, from 0 to 3% of ZrO2, from 0 to 1.8% of Na2O, and from 0 to 1% of K2O, provided that MgO+CaO+SrO+BaO is from 20 to 35%, and Na2O+K2O is from 0 to 2%, in which the glass composition has a glass transition temperature of 680° C. or higher, an average thermal expansion coefficient of from 50×10-7 to 70×10-7/° C., and a temperature at which a viscosity is 102 dPa·s of 1,600° C. or lower. |
