Boron-doped titania-silica glass having very low CTE slope

Patent metadata

Field	Value
Publication number	US-9382150-B2
Application number	US-201514637516-A
Country	US
Kind code	B2
Filing date	Mar 4, 2015
Priority date	Mar 14, 2014
Publication date	Jul 5, 2016
Grant date	Jul 5, 2016

Abstract

A boron-doped titania-silica glass containing 0.1 wt % to 8.0 wt % boron, 9.0 wt % to 16.0 wt % TiO 2 , and 76.0 wt % to 90.9 wt % SiO 2 . The glass may further include F, Nb, Ta, Al, Li, Na, K, Ca, and Mg, individually or in combinations of two or more, at levels up to 4 wt %. The glass may have an OH concentration of more than 10 ppm. The glass features a CTE slope at 20° C. of less than 1 ppb/K 2 . The fictive temperature of the glass is less than 825° C. and the peak CTE of the glass is less than 30 ppb/K. The glass has two crossover temperatures and a wide temperature interval over which CTE is close to zero. The uniformity of each crossover temperature relative to its average over a volume of at least 50 cm 3 is within ±5° C.

First claim

The invention claimed is:

1. A glass comprising 0.1 wt % to 8.0 wt % B 2 O 3 , 9.0 wt % to 16.0 wt % TiO 2 , and 76.0 wt % to 90.9 wt % SiO 2 , said glass having an expansivity slope less than 1 ppb/K 2 at 20° C.

2. The glass of claim 1 , wherein said glass has an expansivity slope less than 0.6 ppb/K 2 at 20° C.

3. The glass of claim 1 , wherein the glass has a first crossover temperature and a second crossover temperature, said second crossover temperature being higher than said first crossover temperature, said first crossover temperature and said second crossover temperature occurring between 10° C. and 150° C., said glass having an expansivity slope of 0±1.5 ppb/K 2 at all temperatures between said first crossover temperature and said second crossover temperature, said glass having a maximum expansivity of less than 30 ppb/K between said first crossover temperature and said second crossover temperature.

4. The glass of claim 3 , wherein said first crossover temperature and said second crossover temperature occur between 20° C. and 60° C., said glass having an expansivity slope of 0±0.5 ppb/K 2 at all temperatures between said first crossover temperature and said second crossover temperature, said glass having a maximum expansivity of less than or equal to 10 ppb/K between said first crossover temperature and said second crossover temperature.

5. The glass of claim 3 , wherein said first crossover temperature has a first average value over a region of said glass having a volume of at least 300 cm 3 , said first crossover temperature varying from said first average value by less than ±3° C. over said region, and said second crossover temperature has a second average value over said region, said second crossover temperature varying from said second average value by less than ±3° C. over said region.

6. The glass of claim 1 , wherein said glass has a fictive temperature less than 775° C.

7. The glass of claim 1 , wherein said glass comprises 3.0 wt % to 7.0 wt % B 2 O 3 and 77.0 wt % to 88.0 wt % SiO 2 .

8. The glass of claim 1 , wherein said glass comprises 10.0 wt % to 16.0 wt % TiO 2 and 76.0 wt % to 89.9 wt % SiO 2 .

9. The glass of claim 8 , wherein said glass comprises 3.0 wt % to 7.0 wt % B 2 O 3 and 77.0 wt % to 87.0 wt % SiO 2 .

10. The glass of claim 1 , further comprising up to 0.4 wt % combined of one or more of F, Nb 2 O 5 , Ta 2 O 5 , Al 2 O 3 , Li 2 O, Na 2 O, K 2 O, MgO, and CaO.

11. The glass of claim 1 , wherein said glass further comprises at least 300 ppm OH.

12. The glass of claim 1 , further comprising 50 ppm-wt to 0.4 wt % of one of F, Nb 2 O 5 , Ta 2 O 5 , Al 2 O 3 , Li 2 O, Na 2 O, K 2 O, MgO, and CaO.

13. The glass of claim 1 , further comprising two or more of F, Nb 2 O 5 , Ta 2 O 5 , Al 2 O 3 , Li 2 O, Na 2 O, K 2 O, MgO, and CaO at a combined concentration of 50 ppm-wt to 0.4 wt %.

14. The glass of claim 1 , wherein said glass further comprises at least 600 ppm OH.

15. The glass of claim 1 , wherein said glass further comprises at least 800 ppm OH.

16. A glass consisting essentially of 0.1 wt % to 8.0 wt % B 2 O 3 , 9.0 wt % to 16.0 wt % TiO 2 , and the remainder SiO 2 , said glass having an expansivity slope at 20° C. less than 0.8 ppb/K 2 .

17. The glass of claim 16 , wherein the glass has a first crossover temperature and a second crossover temperature, said second crossover temperature being higher than said first crossover temperature, said first crossover temperature and said second crossover temperature occurring between 10° C. and 150° C., said glass having an expansivity slope of 0±1.5 ppb/K 2 at all temperatures between said first crossover temperature and said second crossover temperature said glass having a maximum expansivity of less than 30 ppb/K between said first crossover temperature and said second crossover temperature.

18. The glass of claim 17 , wherein said first crossover temperature and said second crossover temperature occur between 20° C. and 60° C., said glass having an expansivity slope of 0±0.5 ppb/K 2 at all temperatures between said first crossover temperature and said second crossover temperature, said glass having a maximum expansivity of less than or equal to 10 ppb/K between said first crossover temperature and said second crossover temperature.

19. The glass of claim 16 , wherein said glass has a fictive temperature less than 775° C.

20. The glass of claim 16 , wherein said glass consists essentially of 3.0 wt % to 7.0 wt % B 2 O 3 , 9.0 wt % to 16.0 wt % TiO 2 , and the remainder SiO 2 .

Assignees

• Corning Inc

Inventors

• Annamalai Sezhian
• Duran Carlos Alberto
• Hrdina Kenneth Edward

Classifications

• C03C3/091

  containing aluminium · CPC title

• C03C2201/42

  containing titanium · CPC title

• C03C2203/40

  Gas-phase processes · CPC title

• C03C3/06 Primary

  with more than 90% silica by weight, e.g. quartz {(C03C3/045 takes precedence)} · CPC title

• C03B25/02

  in a discontinuous way · CPC title