Lamp bulbs for discharge lamps made from aluminosilicate glass, discharge lamps made with same and method of making same

摘要

The lamp bulb for discharge lamps is made from an aluminosilicate glass with a transformation temperature Tg>600° C. The aluminosilicate glass has a composition (in % by weight, based on oxide content) of SiO2>55-64; Al2O3, 13-18; B2O3, 0-5.5; MgO, 0-7; CaO, 5-14; SrO, 0-8; BaO, 6-17; ZrO2, 0-2; TiO2, 0-5, but may contain small amounts of CeO2 and/or Fe2O3, for anti-solarization and fining agents, such as SnO2, Sb2O3 and/or As2O3. The lamp bulbs for the discharge lamps of the invention may include a melted-in molybdenum electrode and/or an electrode feed or they may be free of any internal electrodes. A method for making the lamp bulbs is also described.