Lead-free optical glasses
AssigneeSchott Glas
InventorsMarc Clement, Silke Wolff, Magdalena Winkler-Trudewig
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Abstract
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 number νd 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.
Claims10
An essentially lead-free or lead-free optical glass having a refractive index nd of from 1.65 to 1.87 and an Abbe number νd of from 27 to 43, and comprising in % by weight, based on oxide:
- SiO2 10-25 B2O3 ≧10-25 Na2O 2.5-10 K2O 0-3 CaO 0.5-5 BaO 15-30 ZnO 5-15 TiO2 6-15 ZrO2 0.5-8 Y2O3 0.1-2 La2O3 0.5-8 Nb2O5 6-12 with La2O3 + Nb2O5 ≦17 Ta2O5 0-1 Gd2O3 0-1
- and optionally a fining agent.
An essentially lead-free or lead-free optical glass having a refractive index nd of from 1.65 to 1.87 and an Abbe number νd of from 27 to 43, and comprising in % by weight, based on oxide:
- SiO2 about 10-about 25 B2O3 ≧ about 10-about 25 Na2O about 2.5-about 10 K2O about 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 Gd2O3 0-about 1
- and optionally a fining agent.
Dependencies are inferred from the claim text.