Silicate glasses having low seed concentration

• US 10,040,715 B2
• Filed: 10/11/2017
• Issued: 08/07/2018
• 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): Bolden, Elizabeth A.
• Application Number:
  US15/730,275
• Publication Number:
  US 20180029922A1
• Time in Patent Office: 300 Days
• 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 fining agent for reducing the concentration of seeds or bubbles in a silicate glass. The fining agent includes at least one inorganic compound, such as a hydrate or a hydroxide that acts as a source of water. In one embodiment, the fining agent further includes at least one multivalent metal oxide and, optionally, an oxidizer. A fusion formable and ion exchangeable silicate glass having a seed concentration of less than about 1 seed/cm³ is also provided. Methods of reducing the seed concentration of a silicate glass, and a method of making a silicate glass having a seed concentration of less than about 1 seed/cm³ are also described.

Claims

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

60-70 mol % SiO₂;

6-14 mol Al₂O₃;

0-3 mol % B₂O₃;

0-1 mol % Li₂O;

8-18 mol % Na₂O;

0-5 mol % K₂O;

0-2.5 mol % CaO;

above 0 to 3 mol % ZrO₂;

0-1 mol % SnO₂; and

0-1 mol % CeO₂, wherein

12 mol %<

Li₂O+Na₂O+K₂O≤

20 mol %,

the silicate glass comprises less than 50 ppm As₂O₃, and

the silicate glass is free of halides.

2. The silicate glass of claim 1, wherein the silicate glass is free of SnO₂.

3. The silicate glass of claim 1, wherein the silicate glass comprises 8-12 mol % Al₂O₃.

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

5. The silicate glass of claim 4, wherein the silicate glass comprises 0 mol %≤

MgO+CaO≤

10 mol %.

6. The silicate glass of claim 1, wherein the silicate glass comprises above 0 to 1 mol % Li₂O.

7. The silicate glass of claim 1, wherein the silicate glass is an ion exchanged silicate glass having a surface compressive stress of at least 200 MPa and a surface compressive layer having a depth of at least 30 μ

m.

8. The silicate glass of claim 1, wherein the silicate glass comprises Li₂O+Na₂O+K₂O≥

14 mol %.

9. The silicate glass of claim 1, wherein the silicate glass is formed from an oxidizer fining agent, wherein the oxidizer fining agent is sodium sulfate.

10. The silicate glass of claim 1, wherein the silicate glass is substantially free of barium.

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

60-70 mol % SiO₂;

0-3 mol % B₂O₃;

0-1 mol % Li₂O;

8-18 mol % Na₂O;

0-5 mol % K₂O;

0-2.5 mol % CaO;

above 0 to 3% mol ZrO₂;

0-1 mol % CeO₂; and

Al₂O₃, wherein

12 mol %<

Li₂O+Na₂O+K₂O≤

20 mol %,

the silicate glass is substantially free of As₂O₃,

the silicate glass is free of halides, and

the silicate glass is free of SnO₂.

12. The silicate glass of claim 11, wherein the silicate glass is substantially free of barium.

13. The silicate glass of claim 11, wherein the silicate glass comprises up to 8 mol % MgO.

14. The silicate glass of claim 11, wherein the silicate glass comprises 0 mol %≤

MgO+CaO≤

10 mol %.

15. The silicate glass of claim 14, wherein the silicate glass comprises 2 mol %≤

MgO+CaO≤

7 mol %.

16. The silicate glass of claim 11, wherein the silicate glass is an ion exchanged silicate glass having a surface compressive stress of at least 200 MPa and a surface compressive layer having a depth of at least 30 μ

m.

17. The silicate glass of claim 11, wherein the silicate glass comprises Li₂O+Na₂O+K₂O≥

14 mol %.

18. The silicate glass of claim 11, wherein the silicate glass comprises above 0 to 1 mol % Li₂O.

19. The silicate glass of claim 11, wherein the silicate glass comprises 6-14 mol % Al₂O₃.

20. The silicate glass of claim 11, 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 20, wherein the silicate glass is formed from an oxidizer fining agent, wherein the oxidizer fining agent is sodium sulfate.

22. The silicate glass of claim 11, wherein the silicate glass comprises less than 50 ppm As₂O₃.

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

60-70 mol % SiO₂;

6-14 mol % Al₂O₃;

0-3 mol % B₂O₃;

1-7 mol % MgO;

0-5 mol % Li₂O;

8-18 mol % Na₂O;

0-5 mol % K₂O;

0-2.5 mol % CaO;

above 0 to 3% mol ZrO₂;

0-1 mol % SnO₂; and

0-1 mol % CeO₂, wherein

12 mol %<

Li₂O+Na₂O+K₂O≤

20 mol %,

the silicate glass comprises less than 50 ppm As₂O₃, and

the silicate glass is free of halides.

24. The silicate glass of claim 23, wherein the silicate glass free of SnO₂.

25. The silicate glass of claim 23, wherein the silicate glass is substantially free of barium.

26. The silicate glass of claim 23, wherein the silicate glass is an ion exchanged silicate glass having a surface compressive stress of at least 200 MPa and a surface compressive layer having a depth of at least 30 μ

m.

27. The silicate glass of claim 23, wherein the silicate glass comprises Li₂O+Na₂O+K₂O≥

14 mol %.

28. The silicate glass of claim 23, wherein the silicate glass comprises above 0 to 0.5 mol % Li₂O.

29. The silicate glass of claim 23, wherein the silicate glass comprises above 0 to 1 mol % Li₂O.

30. The silicate glass of claim 23, wherein the silicate glass comprises 8-12 mol % Al₂O₃.