| 摘要 |
<p>A glass composition that can optically replace, for example, conventional cover glass, and that exhibits high ultraviolet transmission in the region of 250 to 260 nm wavelength. There is provided a glass composition containing, as a fundamental glass formulation, expressed by mass proportion per hundred or mass proportion per million, 60 to 79% SiO<SUB>2</SUB>, over 0 to 10% Al<SUB>2</SUB>O<SUB>3</SUB>, 0 to 10% Li<SUB>2</SUB>O, 5 to 25% Na<SUB>2</SUB>O, 0 to 15% K<SUB>2</SUB>O, 0 to 10% MgO, 0 to 15% CaO, 0 to 15% SrO, 0 to 15% BaO, 0.5 to 20 ppm T-Fe<SUB>2</SUB>O<SUB>3</SUB> (provided that T-Fe<SUB>2</SUB>O<SUB>3 </SUB>is the content of all iron oxides expressing all iron compounds in terms of Fe<SUB>2</SUB>O<SUB>3</SUB>) and 0 to 200 ppm TiO<SUB>2</SUB>, which glass composition is characterized by having a refractive index (n<SUB>d</SUB>) of 1.519 to 1.530.</p> |
