BROWN GLASS WHICH ABSORBS ULTRAVIOLET RADIATION

摘要

The invention relates to brown glasses which absorb ultraviolet radiation, characterized by the fact that they have the following composition, expressed in wt.% based on the oxides: SiO2 59-78; Al2O3 2-6; B2O3 0-3; Na2O 7-16; K2O 29; CaO 0-7; BaO 0-12; ZnO 0-12; ZrO2 0-6; TiO2 0-6; MnO2 0.25-6; V2O5 1-3; Fe2O3 0-1.5; NiO 0-0.5; CoO 0-0.1; Sb2O3 0-0.7; As2O3 0-0.7; F 0.05-1.0; with MnO2 + Fe2O3 + V2O5 > 1.5 and Al2O3 + SiO2 65. Used for the production of ophthalmic sun glasses.