초록 ▼

The alumino-silicate glass for lamp bulbs with molybdenum components contains alkaline earth metals and has the following composition (in % by weight based on oxide): SiO2>58 to 62, Al2O3 15 to 17.5, MgO 0.1 to <1, CaO 5.5 to 14, SrO 0 to 8, BaO 6 to 17, ZrO2 0 to 1, CeO2 0 to 0.3, TiO2 0 to 5

The alumino-silicate glass for lamp bulbs with molybdenum components contains alkaline earth metals and has the following composition (in % by weight based on oxide): SiO2>58 to 62, Al2O3 15 to 17.5, MgO 0.1 to <1, CaO 5.5 to 14, SrO 0 to 8, BaO 6 to 17, ZrO2 0 to 1, CeO2 0 to 0.3, TiO2 0 to 5, MoO3 0 to 2, Bi2O3 0 to 4, with a sum total amount of alkaline earth oxides from 11.6 to 29. In addition, the alumino-silicate glass is free of B2O3 so that it has a high thermal stability. Lamp bulbs made with this glass can withstand a bulb temperature of greater than 650° C.

대표청구항 ▼

We claim: 1. An alumino-silicate glass for lamp bulbs that have molybdenum components, said glass containing alkaline earth metals and having a composition, in % by weight on an oxide basis, of: SiO2 >58-62 Al2O3 15-17.5 MgO 0.1-<1 CaO 5.5-14 SrO 0-8 BaO 6-1

We claim: 1. An alumino-silicate glass for lamp bulbs that have molybdenum components, said glass containing alkaline earth metals and having a composition, in % by weight on an oxide basis, of: SiO2 >58-62 Al2O3 15-17.5 MgO 0.1-<1 CaO 5.5-14 SrO 0-8 BaO 6-17 ZrO2 0-1 CeO2 0-0.3 TiO2 0-5 MoO3 0-2 Bi2O3 0-4 Σ RO 11.6-29, wherein RO is an alkaline earth metal oxide and said glass does not contain any B2O3. 2. An alumino-silicate glass for lamp bulbs that have molybdenum components, said glass containing alkaline earth metals and having a composition, in % by weight on an oxide basis, of: SiO2 59-61 Al2O3 15.3-17.2 MgO 0.2-<1 CaO >8-13.5 SrO 0-8 BaO >7-15 ZrO2 0.05-1 CeO2 0-0.3 TiO2 0-3 MoO3 0-2 Bi2O3 0-4 Σ RO 21-26, wherein RO is an alkaline earth metal oxide and said glass does not contain any B2O3. 3. The glass according to claim 1, having an alkali metal oxide content of <0.03% by weight and a water content of <0.02% by weight. 4. The glass according to claim 1, containing more than 10% by weight of BaO. 5. The glass according to claim 1, containing at least 0.5% by weight of MgO. 6. The glass according to claim 1, containing at least 0.5% by weight of TiO2. 7. The glass according to claim 1, containing at least 0.005% by weight of CeO2. 8. The glass according to claim 1, having a coefficient of thermal expansion, α20/300, of between 4.3·10-6/K and 4.95·10-6/K and a transformation temperature, Tg, of greater than 775° C. 9. A lamp bulb having a bulb temperature of greater than 650° C., said lamp bulb comprising an alumino-silicate glass, said glass containing alkaline earth metals and having a composition, in % by weight on an oxide basis, of: SiO2 >58-62 Al2O3 15-17.5 MgO 0.1-<1 CaO 5.5-14 SrO 0-8 BaO 6-17 ZrO2 0-1 CeO2 0-0.3 TiO2 0-5 MoO3 0-2 Bi2O3 0-4 Σ RO 11.6-29, wherein RO is an alkaline earth metal oxide and said glass does not contain any B2O3.