Preferably Pb-free and As-free optical glasses with Tg less than or equal to 500 degree centigrade

• US 20040132606A1
• Filed: 12/02/2003
• Published: 07/08/2004
• Est. Priority Date: 12/03/2002
• Status: Active Grant

• Current Assignee: Schott AG (Carl-Zeiss-Stiftung)
• Original Assignee: Schott AG (Carl-Zeiss-Stiftung)
• Inventors: Woelfel, Ute, Wolff, Silke
• Granted Patent: US 6,960,545 B2
• Time in Patent Office: Days
• US Class Current: 501/66
• CPC Class Codes: C03C 3/118 containing aluminium
• CPC Class Codes: Y10S 501/902 having ABBE number at least 70
• CPC Class Codes: Y10S 501/903 having refractive index less than 1.8 and ABBE number less than 70

Abstract

The present invention relates to preferably lead-free and arsenic-free optical glasses, having a refractive index of 1.48≦n_d≦1.56, an Abbe number of 64 ≦vd≦72, a low transformation temperature (Tg≦500° C.) and good ion exchange properties, as well as good chemical resistance and crystallization stability, and comprising the following composition (in % by weight):

SiO₂53-58B₂O₃11-15Al₂O₃16-20Na₂O 0-13K₂O 0-13ΣM₂O 9-13F0.5-4  

The glass may additionally contain standard refining agents. The invention also relates to the use of the optical glasses according to the invention in the application areas of imaging, projection, telecommunications, optical communication technology and/or laser technology.

Claims

1. Optical glass having a refractive index n_d of 1.48 ≦

nd≦

1.56, an Abbe number V_d of 64≦

V_d≦

72 and a transformation temperature Tg≦

500°

C., which comprises the following composition (in % by weight);

2. Optical glass according to claim 1, which comprises the following composition (in % by weight):

3. Optical glass according to claim 1 or 2, which comprises the following composition (in % by weight):

4. Optical glass according to one of the preceding claims, which as refining agents contains the following components (in % by weight):

5. Use of a glass according to one of claims 1 to 4 for an optical element in the application areas of imaging, projection, telecommunications, optical communication technology and/or laser technology.