Lead-free and arsenic-free niobium phosphate optical glass

US7553785B2 · kind B2 · utility

Assignee

• Schott AG · DE

Inventors

• Simone Monika Ritter · Mainz, DE
• Ute Woelfel · Bingen, DE
• Stefanie Hansen · Gensingen, DE

Key dates

• Filing date: Aug 15, 2006
• Grant date: Jun 30, 2009
• Expiry date: Jun 6, 2027

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C03C3/253
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

The lead-free, arsenic-free, preferably gadolinium-free and fluorine-free, optical glass has a refractive index of 1.86≦nd≦1.95, an Abbe number of 19≦vd≦24, a transformation temperature of ≦595° C., preferably ≦550° C., good crystallization stability, good processing properties and production properties. The optical glass is free of Na2O, frre of B2O3 and has a composition (based on oxide content in % by weight) of P2O5, 14-31; Nb2O5, 22-50; Bi2O3, 5-36; WO3, >10-25; GeO2, 0-14; Li2O, 0-6; K2O, 0-6; Cs2O, 1-7; MgO, 0-6; CaO, 0-6; SrO, 0-6; BaO, 0-6; ZnO, 0-6; TiO2, 0-4; Σ alkali oxides, 2-12; Σ alkaline earth oxides, 0-10; Σ Nb2O5, WO3, Bi2O3≦50 and fining agents, 0-2.