摘要 |
Zirconium-containing BaO- and PbO-free X-ray opaque glasses having a refractive index nd of about 1.518 to about 1.533 and a high X-ray opacity with an aluminum equivalent thickness of at least about 180% are provided. Such glasses are based on a SiO2—Al2O3—B2O3 system with additions of K2O, ZrO2, and one or both of La2O3 and Cs2O. Such glasses may be used, in particular, as dental glasses or as optical glasses. |