Optical and ophthalmic glass with refractive indices greater than or equal to 1.56, Abbe numbers greater than or equal to 40 and densities less than or equal to 2.70 g/cm.sup.3

US4562161A · kind A · utility

Assignee

• Schott Glaswerke · DE

Inventors

• Karl Mennemann · Taunusstein, DE
• 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 18, 1983
• Grant date: Dec 31, 1985
• Expiry date: Feb 18, 2003

Classification

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

Abstract

An optical and ophthalmic glass with high refractive index, high Abbe number and low density, which is distinguished by good chemical stability, good crystallization behavior and capability for chemical hardening, comprises (in % by weight): PA1 SiO.sub.2 --47 to 75 PA1 B.sub.2 O.sub.3 --1 to 20 PA1 Al.sub.2 O.sub.3 --0 to 10 PA1 P.sub.2 O.sub.5 --0 to 5 PA1 Li.sub.2 O--0 to 15 PA1 Na.sub.2 O--0 to 10 PA1 K.sub.2 O--0 to 10 PA1 CaO--0 to 20 PA1 MgO--0 to 15 PA1 SrO--0 to 4 PA1 BaO--0 to 4 PA1 ZnO--0 to 5 PA1 TiO.sub.2 --1 to 15 PA1 ZrO.sub.2 --0 to 8 PA1 Nb.sub.2 O.sub.5 --0 to 5 and PA1 F----0 to 5.