Patent ID: 8575050
Filing Date: 2013-11-05
Classification: C03C

Abstract:
1. A glass composition comprising, in terms of mass%: 56.5% or more and less than 58.4% of SiO 8 to 10% of B 18 to 20% of Al 3 to 5% of MgO; 0.2 to 4.5% of CaO; 5 to 11.5% of SrO; 0.1 to 1% of K 0 to 1% of SnO 0 to 0.2% of Fe the glass composition is substantially free of BaO, a total content of alkaline earth metal oxides (MgO+CaO+SrO) is 12 to 16 mass %, and a mass ratio of the content of CaO to the total content of the alkaline earth metal oxides is 0.01 to 0.23, a mass ratio of the content of MgO to the total content of the alkaline earth metal oxides is 0.2 to 0.3, and a mass ratio of the content of SrO to the total content of the alkaline earth metal oxides is 0.4 to 0.74, and a devitrification temperature of the glass composition is 1130° C. or lower.