Fluorine-free optical glass

US8114796B2 · kind B2 · utility

Assignee

• Schott AG · DE

Inventors

• Simone Monika Ritter · Mainz, DE
• Ute Woelfel · Bingen, DE

Key dates

• Filing date: Oct 2, 2007
• Grant date: Feb 14, 2012
• Expiry date: May 4, 2030

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C03C3/19
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

The lead-free and fluorine-free optical glass has a refractive index of 1.60≦nd≦1.64 and an Abbe number of from 56≦vd≦64, a transformation temperature less than or equal to 590° C., can be precise pressed and is stable to cystallization. The glass has the following, composition (in weight-% based on oxide content. P2O5, 26-35; B2O3, 10-15; Al2O3, 5.5-10; BaO, 25-37; SrO, 0-6; CaO, 8-15; ZnO, 3-10; Bi2O3, 0-8; Na2O, 0-2; K2O, 0-2; WO3, 0-10; La2O3, 0-2; Nb2O5, 0-1; TiO2,0-<1; Σ alkaline earth metal oxides ≧40; Σ alkali metal oxides, 0-2 and at least one fining agent, 0-0.5.