| abstract |
The invention relates to a glass composition for electric lamps which glass composition comprises SiO2, Al2O3, Na2O, K2O, Li2O, B2O3, BaO and SrO and optionally CaO, MgO, ZnO, P2O5, Sb2O3, TiO2, MnO2, Fe2O3 and/or CeO2. The composition according to the invention has a B2O3 content of 1 to 2.8 mass %, a SrO content of 2.1 to 4.5 mass %, a BaO content of 3 to 6 mass % and of the components being present optionally, the amount of CaO is maximum 1 mass %, that of MgO is maximum 2.4 mass % and that of ZnO is maximum 3 mass %, on the condition that the total amount of SrO and B2O3 is at least 3.6 mass %, the total amount of CaO and MgO is maximum 2.4 mass % and the total amount of MgO and ZnO is maximum 4.5 mass %. |