Patent ID: 6128924
Filing Date: 2000-10-10
Classification: C03B,C03C

Abstract:
A commercially manufactured silicate sheet glass having a melting point greater than about 1500.degree. C. and comprising at least one fining agent selected from the group consisting of Sb.sub.2 O.sub.3, CeO.sub.2, SnO.sub.2, Fe2O.sub.3, halide containing compounds, and mixtures thereof, said glass (i) having an As.sub.2 O.sub.3 content of less than 0.02 mole percent, (ii) having a .beta.-OH value below about 0.5/mm, (iii) having a liquidus viscosity greater than 400,000 poise, and (iv) consisting essentially, expressed in terms of mole percent on the oxide basis, of: SiO.sub.2 60-73 MgO 0-5 Al.sub.2 O.sub.3 8-14 CaO 1-13 B.sub.2 O.sub.3 5-17 SrO 0-8 TiO.sub.2 0-5 BaO 0-14 Ta.sub.2 O.sub.5 0-5  wherein said glass has a level of gaseous inclusions that is less than or equal to 0.26 inclusions per pound.