Silicate glasses having low seed concentration

• US 8,431,502 B2
• Filed: 06/13/2012
• Issued: 04/30/2013
• Est. Priority Date: 02/26/2008
• Status: Active Grant

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Dejneka, Matthew John, Gomez, Sinue
• Primary Examiner(s): Group, Karl
• Assistant Examiner(s): Bolden, Elizabeth A
• Application Number:
  US13/495,355
• Publication Number:
  US 20120252652A1
• Time in Patent Office: 321 Days
• Field of Search: 501/66, 501/67, 501/68, 501/69
• US Class Current: 501/68
• CPC Class Codes: C03B 17/064 by the overflow downdraw fusion process; Isopipes therefor
• CPC Class Codes: C03B 5/225 Refining C03B5/18 takes precedence ; Refining agents C03C1/004
• CPC Class Codes: C03C 1/004 Refining agents refining C03B5/225
• CPC Class Codes: C03C 14/008 the non-glass component being in molecular form
• CPC Class Codes: C03C 21/002 to perform ion-exchange between alkali ions C03C21/005 takes precedence
• CPC Class Codes: C03C 3/083 containing aluminium oxide or an iron compound
• CPC Class Codes: C03C 3/085 containing an oxide of a divalent metal
• CPC Class Codes: C03C 3/087 containing calcium oxide, e.g. common sheet or container glass
• CPC Class Codes: C03C 3/091 containing aluminium
• CPC Class Codes: C03C 3/095 containing rare earths
• CPC Class Codes: Y02A 40/28 specially adapted for farming
• CPC Class Codes: Y10T 428/315 Surface modified glass [e.g., tempered, strengthened, etc.]

Abstract

A fusion formable and ion exchangeable silicate glass having a seed concentration of less than about 1 seed/cm³.

Claims

1. A silicate glass, the silicate glass having a seed concentration of less than about 1 seed/cm³, wherein the silicate glass comprises:

60-72 mol % SiO₂;

6-14 mol % Al₂O₃;

0-3 mol % B₂O₃;

0-1 mol % Li₂O;

0-20 mol % Na₂O;

0-10 mol % K₂O;

0-2.5 mol % CaO;

0-5 mol % ZrO₂;

0-1 mol % SnO₂; and

0-1 mol % CeO₂, wherein 12 mol %≦

Li₂O+Na₂O+K₂O≦

20 mol %, and wherein the silicate glass comprises less than 50 ppm As₂O₃ and less than 50 ppm Sb₂O₃.

2. The silicate glass of claim 1, wherein the silicate glass further comprises up to about 8 mol % MgO.

3. The silicate glass of claim 2, wherein 0 mol %≦

MgO+CaO≦

10 mol %.

4. The silicate glass of claim 1, wherein the silicate glass comprises 0.1-1 mol % SnO₂.

5. The silicate glass of claim 1, wherein the silicate glass comprises 0.1-1 mol % CeO₂.

6. The silicate glass of claim 1, wherein the silicate glass is formed from batch or raw materials that include at least one of a hydrate fining agent, a hydroxide fining agent, or an oxidizer fining agent.

7. The silicate glass of claim 1, wherein the silicate glass is formed from batch or raw materials that include up to 4 mol % of at least one oxidizer fining agent.

8. The silicate glass of claim 7, wherein the at least one oxidizer fining agent comprises sodium sulfate, aluminum nitrate, alkali metal nitrates, alkaline earth metal nitrates, zirconium nitrate, ammonium nitrate, or combinations thereof.

9. The silicate glass of claim 7, wherein the at least one oxidizer fining agent comprises sodium sulfate.

10. The silicate glass of claim 1, wherein the silicate glass is ion-exchangeable, and when ion exchanged, has a surface compressive stress of at least about 200 MPa and a surface compressive layer having a depth of at least about 30 μ

m.

11. The silicate glass of claim 1, wherein the silicate glass comprises 0% SO₃.

12. The silicate glass of claim 1, wherein the silicate glass comprises 60-70 mol % SiO₂ and 8-18 mol % Na₂O.

13. A silicate glass, the silicate glass having a seed concentration of less than about 1 seed/cm³, wherein the silicate glass comprises:

60-72 mol % SiO₂;

6-14 mol % Al₂O₃;

0.63-3 mol % B₂O₃;

0-1 mol % Li₂O;

0-20 mol % Na₂O;

0-10 mol % K₂O;

0.57-10 mol % CaO;

0-5 mol % ZrO₂;

0-1 mol % SnO₂; and

0-1 mol % CeO₂, wherein 12 mol %≦

Li₂O+Na₂O+K₂O≦

20 mol %, wherein the silicate glass comprises less than 50 ppm As₂O₃.

14. The silicate glass of claim 13, wherein the silicate glass further comprises up to about 8 mol % MgO.

15. The silicate glass of claim 14, wherein 0 mol %≦

MgO+CaO≦

10 mol %.

16. The silicate glass of claim 13, wherein the silicate glass comprises less than 50 ppm of Sb₂O₃.

17. The silicate glass of claim 13, wherein the silicate glass comprises 0.1-1 mol % SnO₂.

18. The silicate glass of claim 13, wherein the silicate glass comprises 0.1-1 mol % CeO₂.

19. The silicate glass of claim 13, wherein the silicate glass comprises 0.57-2.5 mol % CaO.

20. The silicate glass of claim 13, wherein the silicate glass is formed from batch or raw materials that include at least one of a hydrate fining agent, a hydroxide fining agent, or an oxidizer fining agent.

21. The silicate glass of claim 13, wherein the silicate glass is formed from batch or raw materials that include up to 4 mol % of at least one oxidizer fining agent.

22. The silicate glass of claim 13, wherein the at least one oxidizer fining agent comprises sodium sulfate, aluminum nitrate, alkali metal nitrates, alkaline earth metal nitrates, zirconium nitrate, ammonium nitrate, or combinations thereof.

23. The silicate glass of claim 13, wherein the silicate glass is ion-exchangeable, and when ion exchanged, has a surface compressive stress of at least about 200 MPa and a surface compressive layer having a depth of at least about 30 μ

m.

24. The silicate glass of claim 13, wherein the silicate glass comprises greater than 0% ZrO₂.

25. The silicate glass of claim 13, wherein the silicate glass comprises 60-70 mol % SiO₂ and 8-18 mol % Na₂O.

26. A silicate glass, the silicate glass having a seed concentration of less than about 1 seed/cm³, wherein the silicate glass comprises:

60-72 mol % SiO₂;

6-14 mol % Al₂O₃;

0-15 mol % B₂O₃;

0-1 mol % Li₂O;

0-20 mol % Na₂O;

0-10 mol % K₂O;

0-10 mol % CaO;

0-5 mol % ZrO₂;

0-1 mol % SnO₂; and

0-1 mol % CeO₂, wherein 12 mol %≦

Li₂O+Na₂O+K₂O≦

20 mol %, wherein 0.1 mol % SnO₂+CeO₂≦

2 mol %, and wherein the silicate glass is formed from batch or raw materials that include at least one oxidizer fining agent.

27. The silicate glass of claim 26, wherein the silicate glass comprises 0.1-1 mol % CeO₂.

28. The silicate glass of claim 26, wherein the silicate glass comprises less than 50 ppm As₂O₃ and less than 50 ppm of Sb₂O₃.

29. The silicate glass of claim 26, wherein the silicate glass comprises 0.63-15 mol % B₂O₃.

30. The silicate glass of claim 26, wherein the silicate glass comprises 0.57-10 mol % CaO.