Alkali and alkaline earth alumino-boro-silico-phosphate glass - also contg. zinc and lead, having good wetting properties without misting under high humidity conditions

摘要

Glass compsn. comprises (in mol.%) 47-65% P2O5, 0-12% SiO2, 0-10% B2O3, 6-15% SiO2+B2O3, 0-30% alkali metal oxides, 20-45% alkali(ne earth) metal oxides, 0-5% Al2O3, 0-10% ZnO and 0-5% PbO. The alkaline earth metal oxides are composed of e.g., 0-25% MgO, 0-30% CaO, 0-25% SrO and 0-14% BaO. The above components are well admixed and are poured directly into a platinum crucible heated at 1150 degrees C in electric furnace, then being clarified, and are cast for moulding. The glass displays wetting even when exposed to an atmos. of R.H. >60%, showing no clouding, with improved water resistance and increased hardness. It is suitable for use in glasses, windows, mirrors, and other optical devices.