Highly refractive and highly transparent optical glass

US8476177B2 · 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: Dec 2, 2010
• Grant date: Jul 2, 2013
• Expiry date: Oct 11, 2031

Classification

• Technology area (CPC G): Physics
• CPC primary: G02B1/00
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

The optical glass has a refractive index nd of 1.945≦nd≦1.97, an Abbe number νd of 33≦νd≦36, and a composition with the following components in amounts expressed in % of their cations, with respect to the total number of cations in the composition: B3+, 35-46; La3+, 25-35; Ta5+, 6-14; W6+, 6-13; Zr4+, 1-7; Gd3+, 0-5; Nb5+, 0-4; Y+3, 0-4; Ba2+, 0-2; Σ alkaline earth metal cations, 0-2, Σ La3++Ta3++W6++Zr4++Gd3++Nb5++Y3+≧50; and at least one fining agent, 0-0.3. Also a ratio of B3+ to La+3 is 1.1 to 1.6 and a ratio of B3+ to Σ Si+4+B3+ is ≧0.5. The glass is free of lead, arsenic, Ti4+, Th4+, Zn2+, F−, and Hf+4.