Photochromic glass with sharp cutoff

Patent metadata

Field	Value
Publication number	US-10683232-B2
Application number	US-201816121920-A
Country	US
Kind code	B2
Filing date	Sep 5, 2018
Priority date	Dec 18, 2015
Publication date	Jun 16, 2020
Grant date	Jun 16, 2020

Abstract

A photochromic glass that includes a base glass and a photochromic agent is described. The base glass is a modified boroaluminosilicate glass and the photochromic agent is a nanocrystalline cuprous halide phase. The photochromic glass exhibits a sharp cutoff in the UV or short wavelength visible portion of the spectrum along with an absorption band at longer wavelengths in the visible. The nanocrystalline cuprous halide phase includes Cu2+, which provides states within the bandgap of the cuprous halide that permit the glass to absorb visible light. Absorption of visible light drives a photochromic transition without compromising the sharp cutoff. The nanocrystalline cuprous halide phase may optionally include Ag.

First claim

What is claimed is:

1. A method of making a photochromic glass comprising:
melting a batch composition, said batch composition including 19 wt %-39 wt % B 2 O 3 , 0.5 wt %-15 wt % Al 2 O 3 , 46 wt %-65 wt % SiO 2 , 3.5 wt %-12.5 wt % alkali metal oxide, 0.40 wt %-2.5 wt % CuO, 0.01 wt %-1.3 wt % halide, and silver oxide.

2. The method of claim 1 , wherein said batch composition includes 22 wt %-35 wt % B 2 O 3 , 1.0 wt %-11 wt % Al 2 O 3 , 50 wt %-61 wt % SiO 2 , 4.5 wt %-10.5 wt % alkali metal oxide, 0.60 wt %-1.8 wt % CuO, and 0.10 wt %-0.60 wt % halide.

3. The method of claim 1 , wherein said halide includes Cl.

4. The method of claim 3 , said batch composition includes 0.01 wt %-0.80 wt % of said halide.

5. The method of claim 3 , said batch composition includes 0.05 wt %-0.50 wt % of said halide.

6. The method of claim 1 , wherein said halide includes Cl and Br.

7. The method of claim 6 , wherein said batch composition includes 0.01 wt %-0.60 wt % of said Cl and 0.01 wt %-0.70 wt % of said Br.

8. The method of claim 6 , wherein said batch composition includes 0.01 wt %-0.40 wt % of said Cl and 0.01 wt %-0.50 wt % of said Br.

9. The method of claim 1 , wherein said batch composition further includes a redox agent.

10. The method of claim 9 , wherein said redox agent comprises Sn.

11. The method of claim 10 , wherein said batch composition includes up to 0.80 wt % of said redox agent.

12. The method of claim 1 , further comprising cooling said batch composition, said cooling occurring after said melting.

13. The method of claim 12 , wherein said cooling includes maintaining said batch composition at a temperature in the range from 480° C.-550° C. for at least 1 hour.

14. The method of claim 12 , wherein said cooling includes maintaining said batch composition at a temperature in the range from 480° C.-550° C. for at least 4 hours.

15. The method of claim 12 , wherein said cooling includes maintaining said batch composition at a temperature in the range from 480° C.-550° C. for at least 8 hours.

16. The method of claim 12 , wherein said cooling solidifies said batch composition to form a glass.

17. The method of claim 16 , further comprising heating said glass, said heating including maintaining said glass at a temperature in the range from 480° C.-550° C. for a time in the range from 1 min to 24 hour.

18. The method of claim 17 , wherein heating includes maintaining said glass at a temperature in the range from 480° C.-550° C. for a time in the range from 1 min-12 hours.

19. The method of claim 17 , wherein heating includes maintaining said glass at a temperature in the range from 480° C.-550° C. for a time in the range from 1 hour-10 hours.

20. A method of making a photochromic glass comprising:
melting a batch composition, said batch composition including 19 wt %-39 wt % B 2 O 3 , 0.5 wt %-15 wt % Al 2 O 3 , 46 wt %-65 wt % SiO 2 , 3.5 wt %-12.5 wt % alkali metal oxide, 0.40 wt %-2.5 wt % CuO, and 0.01 wt %-1.3 wt % halide; and
cooling said batch composition, said cooling occurring after said melting, said cooling includes maintaining said batch composition at a temperature in the range from 480° C.-550° C. for at least 1 hour.

21. The method of claim 20 , wherein said batch composition includes 22 wt %-35 wt % B 2 O 3 , 1.0 wt %-11 wt % Al 2 O 3 , 50 wt %-61 wt % SiO 2 , 4.5 wt %-10.5 wt % alkali metal oxide, 0.60 wt %-1.8 wt % CuO, and 0.10 wt %-0.60 wt % halide.

22. The method of claim 20 , wherein said halide includes Cl.

23. The method of claim 22 , said batch composition includes 0.01 wt %-0.80 wt % of said halide.

24. The method of claim 22 , said batch composition includes 0.05 wt %-0.50 wt % of said halide.

25. The method of claim 20 , wherein said halide includes Cl and Br.

26. The method of claim 25 , wherein said batch composition includes 0.01 wt %-0.60 wt % of said Cl and 0.01 wt %-0.70 wt % of said Br.

27. The method of claim 25 , wherein said batch composition includes 0.01 wt %-0.40 wt % of said Cl and 0.01 wt %-0.50 wt % of said Br.

28. The method of claim 20 , wherein said batch composition further includes a redox agent.

29. The method of claim 20 , wherein said cooling includes maintaining said batch composition at a temperature in the range from 480° C.-550° C. for at least 4 hours.

30. The method of claim 20 , wherein said cooling solidifies said batch composition to form a glass.

31. The method of claim 30 , further comprising heating said glass, said heating including maintaining said glass at a temperature in the range from 480° C.-550° C. for a time in the range from 1 min to 24 hour.

Assignees

• Corning Inc

Inventors

• Araujo Roger Jerome
• Borrelli Nicholas Francis
• Lönnroth Nadja Teresia
• Morse David Lathrop
• Seward Iii Thomas Philip

Classifications

• C03C14/006 Primary

  the non-glass component being in the form of microcrystallites, e.g. of optically or electrically active material · CPC title

• C03C2204/00

  Glasses, glazes or enamels with special properties · CPC title

• Y02P40/57

  Improving the yield, e-g- reduction of reject rates · CPC title

• C03C4/085

  for ultraviolet absorbing glass · CPC title

• G02B5/226

  Glass filters · CPC title