| abstract |
Glass compositions having from 50 to 80 mol% SiO 2 , less than or equal to 25 mol% Al 2 O 3 , from 6.5 to 10.0 mol% Li 2 O and, optionally, other components, such as alkali metal oxides, alkaline earth metal oxides, zinc oxide, phosphorus oxides, rare earth metal oxides, boron oxide, and small amounts of other species, such as titania, zirconia, and tin oxide. The glass compositions are characterized by zero or positive values of the ratios, in terms of mol%: Al 2 O 3 - ΣR 2 O≥ 0, or Al 2 O 3 - ΣR 2 O - ΣRO ≥0, or Al 2 O 3 - ΣR 2 O - ΣRO - P 2 O 5 ≥ 0, where R 2 O means alkali metal oxides and RO means divalent metal oxides. The glass compositions may have a liquidus viscosity greater than or equal to 1000 Poises to less than or equal to 300,000 Poises. |