| 摘要 |
The invention can relate to essentially lead-free optical glasses having a refractive index nd of from about 1.65 to about 1.87 and an Abbe numberνd of from about 27 to about 43 and a composition (in % by weight, based on oxide) of SiO2 about 10-about 25, B2O3>about 10-about 25, Na2O about 2.5-about 10, K2O 0-about 3, CaO about 0.5-about 5, BaO about 15-about 30, ZnO about 5-about 15, TiO2 about 6-about 15, ZrO2 about 0.5-about 8, Y2O3 about 0.1-about 2, La2O3 about 0.5-about 8, Nb2O5 about 6-about 12, with La2O3+Nb2O5<=about 17,Ta2O5 0-about 1, and Gd2O3 0-about 1.
|
