摘要 |
Glass compositions having a refractive index of over 2.10 composed of the following metal oxides, in weight percent; 40.0 to 54.0% of TiO2, 24.0 to 44.0% of BaO, 5.0 to 15.0% of ZnO, 3.0 to 13.0% of ZrO2, 0.2 to 3.0% of CaO, 0.2 to 3.0% of MgO, 0.2 to 2.0% of SiO2, 0.1 to 0.5% of Na2O and/or K2O, and whose total weight exceeds 98.0% and moreover essentially without containing B2O3. |