초록 ▼

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-

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.

대표청구항 ▼

We claim: 1. An electrode-free discharge-lamp bulb without any internal electrode, said discharge-lamp bulb comprising an aluminosilicate glass, wherein said aluminosilicate glass has a transformation temperature Tg >600° C. and a composition, in % by weight, based on oxide content, comprising:

We claim: 1. An electrode-free discharge-lamp bulb without any internal electrode, said discharge-lamp bulb comprising an aluminosilicate glass, wherein said aluminosilicate glass has a transformation temperature Tg >600° C. and a composition, in % by weight, based on oxide content, comprising: SiO2 >55-64; Al2O3 13-18; B2O3 3-5.5; MgO 0-7; CaO 5-14; SrO 0-8; BaO 6-17; ZrO2 0-2; TiO2 0.2-5. 2. The discharge-lamp bulb as defined in claim 1, wherein said aluminosilicate glass has a composition, in % by weight, based on oxide content, comprising: SiO2 59-62; Al2O3 13.5-15.5; B2O3 3-5.5; MgO 2.3-5; CaO 8.2-10.5; SrO 0-8; BaO 8.5-9.5; ZrO2 0-1.5; TiO2 0.2-3. 3. The discharge-lamp bulb as defined in claim 1, wherein said aluminosilicate glass includes at least one fining agent selected from the group consisting of SnO2, Sb2O3 and As2O3 and at least one dopant selected from the group consisting of CeO2 and Fe2O3 and wherein said at least one fining agent is present in said aluminosilicate glass in an amount of from 0 to 1% by weight, based on oxide content, and said at least one dopant is present in said aluminosilicate glass in an amount of from 0 to 5% by weight, based on oxide content. 4. The discharge-lamp bulb as defined in claim 3, wherein said amount of said at least one dopant is from 0 to 1% by weight, based on oxide content. 5. The discharge-lamp bulb as defined in claim 1, wherein said aluminosilicate glass includes at least one dopant selected from the group consisting of CeO2 and Fe2O3 and wherein said at least one dopant is present in said aluminosilicate glass in an amount greater than or equal to 0.01% by weight, based on oxide content. 6. The discharge-lamp bulb as defined in claim 5, wherein said amount of said at least one dopant is greater than or equal to 0.1% by weight, based on oxide content. 7. The discharge-lamp bulb as defined in claim 5, wherein said amount of said at least one dopant is greater than or equal to 0.2% by weight, based on oxide content. 8. The discharge-lamp bulb as defined in claim 1, wherein said transformation temperature of said aluminosilicate glass ≧700° C. and said aluminosilicate glass has a coefficient of thermal expansion, α20/300, of from4.3×10-6/K to4.95×10-6/K. 9. A discharge lamp comprising a discharge-lamp bulb without any internal electrode, said discharge-lamp bulb comprising an aluminosilicate glass, wherein said aluminosilicate glass has a transformation temperature Tg >600° C. and a composition, in % by weight, based on oxide content, comprising: SiO2 >55-64; Al2O3 13-18; B2O3 3-5.5; MgO 0-7; CaO 5-14; SrO 0-8; BaO 6-17; ZrO2 0-2; TiO2 0.2-5; and CeO2 + Fe2O3 0-1. 10. The discharge lamp as defined in claim 9, wherein said aluminosilicate glass comprises at least one fining agent selected from the group consisting of SnO2, Sb2O3 and As2O3 and wherein said at least one fining agent is present in said aluminosilicate glass in an amount of from 0 to 1% by weight, based on oxide content. 11. The discharge lamp as defined in claim 9, consisting of a miniaturized discharge lamp for background illumination of a display. 12. The discharge lamp as defined in claim 9, further comprising respective metal strips acting as external electrodes, which are bonded to opposite ends of the discharge-lamp bulb. 13. A discharge-lamp bulb comprising an aluminosilicate glass, said aluminosilicate glass having a transformation temperature Tg >600° C. and comprising from 0.2 to 5% by weight of TiO2, from 0.2 to 5.5 percent by weight B2O3, from 0.0025 to 0.5 percent by weight of Fe2O3, from 0.002 to 0.5 percent by weight of CeO2, and from 0 to 8 percent by weight SrO; wherein the aluminosilicate glass has a solarization resistance, given as a difference in respective transmissions (τ) at λ=300 nm between a sample that has not been irradiated and a specimen that has been irradiated for 15 hours with a high-pressure mercury discharge lamp with a main emission at 365 nm and an irradiation strength of 850 μW/cm2 at wavelengths between 200 to 280 nm at a distance of 1 m, as Δ15, τ(300 nm), of >10% for a sample of thickness 0.2 mm. 14. The discharge-lamp bulb as defined in claim 13, wherein said transformation temperature is greater than or equal to 700° C., and said aluminosilicate glass has a coefficient of thermal expansion of α20/300=4.3 to 4.95 ×10-6/K. 15. A discharge lamp comprising a discharge-lamp bulb, said discharge-lamp bulb consisting of an aluminosilicate glass, said aluminosilicate glass having a transformation temperature Tg >600° C. and comprising from 0.2 to 5% by weight of TiO2, from 0.2 to 5.5 percent by weight B2O3, from 0.0025-0.5 percent by weight of Fe2O3, from 0.002 to 0.5 percent by weight of CeO2, and from 0 to 8 percent by weight SrO; wherein the aluminosilicate glass has a solarization resistance, given as a difference in respective transmissions (τ) at λ=300 nm between a sample that has not been irradiated and a specimen that has been irradiated for 15 hours with a high-pressure mercury discharge lamp with a main emission at 365 nm and an irradiation strength of 850 μW/cm2 at wavelengths between 200 to 280 nm at a distance of 1 m, as Δ15, τ (300 nm), of <10% for a sample of thickness 0.2 mm. 16. The discharge lamp as defined in claim 15, wherein said transformation temperature is greater than or equal to 700° C., and said aluminosilicate glass has a coefficient of thermal expansion of α20/300=4.3 to 4.95 ×10-/K. 17. A discharge-lamp bulb comprising an aluminosilicate glass having a transformation temperature Tg >600° C., an internal diameter of from 1 to 4.8 mm, and an external diameter of from 2 to 5 mm; wherein said aluminosilicate glass has a composition, in % by weight, based on oxide content, comprising: SiO2 >55-64; Al2O3 13-18; B2O3 3-5.5; MgO 0-7; CaO 5-14; SrO 0-8; BaO 6-17; ZrO2 0-2; and TiO2 0.2-5. 18. A discharge lamp comprising a discharge-lamp bulb with an internal diameter of from 1 to 4.8 mm and with an external diameter of from 2 to 5 mm and a phosphor applied to said discharge-lamp bulb; wherein said discharge-lamp bulb consists of an aluminosilicate glass having a transformation temperature Tg >600° C. and said aluminosilicate glass has a composition, in % by weight, based on oxide content, comprising: SiO2 >55-64; Al2O3 13-18; B2O3 0.2-5.5; MgO 0-7; CaO 5-14; SrO 0-8; BaO 6-17; ZrO2 0-2; TiO2 0.2-5; Fe2O3 0.0025-0.5; CeO2 0.002-0.5.