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US 5,843,856 AGranted
Glass composition
AssigneeGeneral Electric Company
InventorsZoltan Suha, Zsuzsanna Varga
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AssigneeGeneral Electric Company
InventorsZoltan Suha, Zsuzsanna Varga
Estimating the term…
The invention relates to a glass composition for electric lamps which glass composition comprises SiO.sub.2, Al.sub.2 O.sub.3, Na.sub.2 O, K.sub.2 O and B.sub.2 O.sub.3 as well as optionally Li.sub.2 O, CaO, MgO, SrO, Sb.sub.2 O.sub.3, Fe.sub.2 O.sub.3, MnO.sub.2 and/or CeO.sub.2. The composition according to the invention is characterized in that it, in addition to the components listed, comprises ZnO and optionally TiO.sub.2 and/or P.sub.2 O.sub.5 as well, its Al.sub.2 O.sub.3 content is 0.3 to 2 mass %, ZnO content is 2.5 to 8 mass %, B.sub.2 O.sub.3 content is 1.5 to 7.5 mass % and the total amount of Al.sub.2 O.sub.3 and TiO.sub.2 is at least 1 mass %, while the total amount of MgO and ZnO is equal to or greater than the amount of B.sub.2 O.sub.3. The invention also relates to stems and bulbs made of the glass composition according to the invention.
An electric lamp glass composition which is substantially free of PbO and BaO and comprising, expressed in terms of mass percent:
Stem for electric lamps, across which current feedthroughs are introduced and sealed in a vacuum-tight manner, and the said stem is sealed in a vacuum tight-manner in a bulb of the lamp, the stem comprising a glass composition comprising, expressed in terms of mass percent:
Bulb for electric lamps, the bulb comprising with a glass composition comprising, expressed in terms of mass percent:
Dependencies are inferred from the claim text.