Patent ID: 6537937
Filing Date: 2003-03-25
Classification: C03C

Abstract:
An alkali-free glass consisting essentially of:SiO269.5 to 76 mol %,â€ƒâ€‰Al2O35 to 12.5 mol %,B2O35 to 16 mol %,MgO1.5 to 12 mol %,CaO2 to 14 mol %,SrO0 to 3 mol %, andBaO0 to 1.5 mol %, whereinAl2O3/B2O3&lE;1.7, CaO/(MgO+CaO+SrO) is from 0.52 to 0.85, MgO/(MgO+CaO+SrO+BaO) is at least 0.15, the alkali-free glass has a specific gravity of &lE;2.46, and a surface of said alkali-free glass is not turbidified when the glass is immersed in an aqueous hydrochloric acid solution having a concentration of 0.1 mol/l at 90Â° C. for 20 hours.