Boron aluminosilicate glass

US7323427B2 · kind B2 · utility

Assignee

• Schott AG · DE

Inventors

• Silke Wolff · Hückeswagen, DE
• Ute Woelfel · Bingen, DE
• Uwe Kolberg · Mainz, DE
• Holger Kasprzik · Eltville am Rhein, DE

Key dates

• Filing date: Feb 27, 2004
• Grant date: Jan 29, 2008
• Expiry date: Apr 11, 2025

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C03C3/095
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A short optical glass is disclosed which is particularly suited for the applications imaging, projection, telecommunication, optical information technology and/or laser technology, also particularly suited for fiber applications (light guides or imaging guides). Preferably, the glass has a refractive index of 1.54≦nd≦1.62 and an Abbe coefficient of 48≦vd=57. It further has good attenuating and ion exchange characteristics, good chemical stability and good crystallization stability. The glass comprises 35 to 50 wt.-% SiO2, 0.1 to 6 wt.-% B2O3, 0.1 to 7 wt.-% Al2O3, 0.1 to 4 wt.-% P2O5, 4 to 24 wt.-% R2O (alkali oxides), 6 to 14.5 wt.-% BaO, 0 to 12 wt.-% other RO (alkaline earth oxides), 14 to 25 wt.-% ZnO, 0 to 5 wt.-% La2O3, 0 to 10 wt.-% ZrO2, wherein R2O is an alkali oxide, RO is an alkaline earth oxide other than BaO, wherein Li2O is 6 wt.-% at the most, wherein the glass does not contain any GeO2, SnO, SnO2, AgO, Sb2O3 and, preferably, no rare earth oxides, and wherein the glass may be molten while adding suitable purifying agents.