LEAD-FREE OPTICAL GLASSES WITH A HARD FLINT POSITION

• US 20070225146A1
• Filed: 03/16/2007
• Published: 09/27/2007
• Est. Priority Date: 03/22/2006
• Status: Active Grant

• Current Assignee: Schott AG (Carl-Zeiss-Stiftung)
• Original Assignee: Schott AG (Carl-Zeiss-Stiftung)
• Inventors: Hansen, Stefanie, Woelfel, Ute, Wolff, Silke
• Granted Patent: US 7,501,366 B2
• Time in Patent Office: Days
• US Class Current: 501/46
• CPC Class Codes: C03C 13/048 Silica-free oxide glass compositions
• CPC Class Codes: C03C 3/062 with less than 40% silica by weight
• CPC Class Codes: C03C 3/21 containing titanium, zirconium, vanadium, tungsten or molybdenum
• CPC Class Codes: Y10S 501/901 having R.I. at least 1.8

Abstract

Optical glasses are described, which are useful for imaging, sensors, microscopy, medical technology, digital protection, photolithography, laser technology, wafer/chip technology, as well as telecommunication, optical communications engineering and optics/lighting in the automotive sector, with a refractive index of 1.80≦n_d≦1.95 and an Abbe value from 19≦ν_d≦28 with excellent chemical resistance and stability to crystallization. These optical glasses have a composition, in weight % based on oxide content, of: P₂O₅, 14-35; Nb₂O₅, 45-50; Li₂O, 0-4; Na₂O, 0-4; K₂O, 0.5-5; BaO, 17-23; ZnO, 0.1-5; TiO₂, 1-<5; ZrO₂, 06; and Sb₂O₃, 0.1-2.

Claims

1. An optical glass having a composition, in wt. % based on oxide content, of:

2. The glass according to claim 1, which is B₂O₃-free, contamination-free of amounts of SiO₂, and/or contamination-free of residues of metallic crucible materials.

3. The glass according to claim 1, wherein a total amount of said TiO₂ and said ZrO₂ does not exceed 7 wt. % and/or a total amount of alkali metal oxides present does not exceed 8 wt. %.

4. The glass according to claim 1, containing up to 6 wt. % of aluminium oxide.

5. The glass according to claim 1, containing up to 5 wt. % of Ag₂O.

6. The glass according to claim 1, containing at least one oxide selected from the group consisting of La₂O₃, Y₂O₃, Bi₂O₃, Gd₂O₃, GeO₂, Ta₂O₅, Yb₂O₅ and WO₃, and wherein said at least one oxide is present in a total amount of up to 5 wt. %.

7. The glass according to claim 1, containing at least one ingredient selected from the group consisting of MgO, CaO, SrO and F, and wherein said at least one ingredient is present in a total amount of up to 5 wt. %.

8. The glass according to claim 1, which is free of Pt and free of SiO₂.

9. The glass according to claim 1, further comprising one or more of the following components as fining agents, in wt. %:

10. The glass according to claim 1, having a refractive index n_d of 1.80≦

n_d≦

1.95 and/or an Abbe number ν

_d of 19≦

ν

_d≦

28.

11. A method of producing a glass according to claim 1, said method comprising setting oxidizing conditions in a glass melt from which said glass is made.

12. An optical element, which is a lens, prisms light guide rod, array, optical fiber, gradient component or an optical window, said optical element comprising a glass as defined in claim 1.

13. A method of producing an optical element, said method comprising pressing a glass as defined in claim 1 to form said optical element.

14. An optical part or an optical component for imaging, sensors, microscopy, medical technology, digital protection, telecommunication, optical communications engineering/information transmission, optics/lighting in the automotive sector, photolithography, steppers, excimer lasers, wafers, computer chips, as well as integrated circuits and electronic devices which contain such circuits and chips, said optical part or component comprising a glass as defined in claim 1.