Patent ID: 7833919

Claim:
An alkali metal-free glass comprising in mole percent on an oxide basis: SiO 2 64.0-72.0 Al 2 O 3 9.0-16.0 B 2 O 3 1.0-5.0 MgO + La 2 O 3 1.0-7.5 CaO 2.0-7.5 SrO 0.0-4.5 BaO 1.0-7.0 wherein: (i) Σ(MgO+CaO+SrO+BaO+3La 2 O 3 )/(Al 2 O 3 )≧1.15, and (ii) [MgO]:[CaO]:[SrO+BaO]=1±0.15: 1±0.15: 1±0.15, where Al 2 O 3 , MgO, CaO, SrO, BaO, and La 2 O 3 represent the mole percents of the respective oxide components.