Electric lamp comprising a lead-free glass component

Abstract

The electric lamp has a glass component with a composition which, according to the invention, is substantially free of PbO and has the following constituents: 55–70 wt. % SiO2, <0.1 weight % Al2O3, 0.5–4 weight % Li2O, 0.5–3 weight % Na2O, 10–15 wt. % K2O, 0–3 wt. % MgO, 0–4 wt. % CaO, 0.5–5 wt. % SrO, 7–10 wt. % BaO. Preferably, the composition of the glass comprises: 65–70 wt. % SiO2, 1.4–2.2 wt. % Li2O, 1.5–2.5 wt. % Na2O, 11–12.3 wt. % K2O, 1.8–2.6 wt. % MgO, 2.5–5 wt. % CaO, 2–3.5 wt. % SrO, 8–9.5 wt. % BaO. The glass is preferably used as a CFL-envelope glass or as glass for a stem. The electric lamp made with a glass according to the invention has favorable fusion and processing properties, in particular a liquidus temperature Tliq≦800° C.

Dependencies are inferred from the claim text.