Spectacle glass with increased refractive index

US4508834A · kind A · utility

Assignee

• Schott Glaswerke · DE

Inventors

• Georg Gliemeroth · Eltville am Rhein, DE
• Ludwig Ross · Klein-Winternheim, DE
• Burkhard Speit · Mainz, DE
• Volkmar Geiler · Ingelheim am Rhein, DE
• Hans-Georg Krolla · Mainz, DE
• Lothar Meckel

Key dates

• Filing date: Feb 10, 1983
• Grant date: Apr 2, 1985
• Expiry date: Feb 10, 2003

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S501/903
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A spectacle glass which is colorless in the visible spectrum range, not transmissive in the ultraviolet spectrum range below 350 nm, has a refractive index n.sub.d higher than 1.56 and an Abbe number of more than 45, and which has an extremely low density, has the following composition (in % by weight): ______________________________________ 12-40 P.sub.2 O.sub.5 13-34 Al.sub.2 O.sub.3 8-30 SiO.sub.2 0-16 B.sub.2 O.sub.3 4-12 TiO.sub.2 0-4 ZrO.sub.2 2-18 CaO 0-4 MgO 0-15 Na.sub.2 O 0-11 K.sub.2 O 0-6 Li.sub.2 O 0-12 Nb.sub.2 O.sub.5 0-8 ZnO. ______________________________________