REINFORCED GLASS, REINFORCED GLASS SUBSTRATE, AND METHOD FOR PRODUCING THE SAME

• US 20110014475A1
• Filed: 09/18/2008
• Published: 01/20/2011
• Est. Priority Date: 09/27/2007
• Status: Abandoned Application

• Current Assignee: Nippon Electric Glass Company Limited
• Original Assignee: Nippon Electric Glass Company Limited
• Inventors: Murata, Takashi
• Application Number:
  US12/677,178
• Publication Number:
  US 20110014475A1
• Time in Patent Office: Days
• US Class Current: 428/410
• CPC Class Codes: C03B 17/064 by the overflow downdraw fusion process; Isopipes therefor
• 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 3/091 containing aluminium
• CPC Class Codes: G02F 1/133331 Cover glasses
• CPC Class Codes: Y10T 428/315 Surface modified glass [e.g., tempered, strengthened, etc.]

Abstract

Provided is a tempered glass, which has a compressive stress layer on a surface thereof, comprising, in terms of mol %, 40 to 80% of SiO₂, 5 to 15% of Al₂O₃, 0 to 8% of B₂O₃, 0 to 10% of Li₂O, 5 to 20% of Na₂O, 0.5 to 20% of K₂O, 0 to 10% of MgO, and 8 to 16.5% of Al₂O₃+MgO, wherein the glass has, in terms of a molar ratio, a (Li₂O+Na₂O+K₂O)/Al₂O₃ ratio of 1.4 to 3, an Na₂O/Al₂O₃ ratio of 1 to 3, and an MgO/Al₂O₃ ratio of 0 to 1, and is substantially free of As₂O₃, PbO, and F.

Claims

1. A tempered glass, which has a compression stress layer on a surface thereof, comprising, in terms of mol %, 40 to 80% of SiO₂, 5 to 15% of Al₂O₃, 0 to 8% of B₂O₃, 0 to 10% of Li₂O, 5 to 20% of Na₂O, 0.5 to 20% of K₂O, 0 to 10% of MgO, and 8 to 16.5% of Al₂O₃+MgO, wherein the glass has, in terms of a molar ratio, a (Li₂O+Na₂O+K₂O)/Al₂O₃ ratio of 1.4 to 3, an Na₂O/Al₂O₃ ratio of 1 to 3, and an MgO/Al₂O₃ ratio of 0 to 1, and is substantially free of As₂O₃, PbO, and F.

2. The tempered glass according to claim 1, which has a compression stress layer on a surface thereof, comprising, in terms of mol %, 45 to 80% of SiO₂, 8 to 11% of Al₂O₃, 0 to 5% of B₂O₃, 0 to 10% of Li₂O, 5 to 20% of Na₂O, 0.5 to 8% of K₂O, 0 to 6% of CaO, 0 to 6% of MgO, 8 to 16.5% of Al₂O₃+MgO, and 0 to 7% of CaO+MgO, wherein the glass has, in terms of a molar ratio, a (Li₂O+Na₂O+K₂O)/Al₂O₃ ratio of 1.4 to 3, an Na₂O/Al₂O₃ ratio of 1 to 3, an MgO/Al₂O₃ ratio of 0 to 1, and a K₂O/Na₂O ratio of 0.1 to 0.8, and is substantially free of As₂O₃, PbO, and F.

3. The tempered glass according to claim 1, comprising 0.01 to 6% of SnO₂.

4. The tempered glass according to claim 1, wherein an average breaking stress is 300 MPa or more, and a Weibull coefficient is 15 or more.

5. The tempered glass according to claim 1, wherein a compression stress of the surface is 300 MPa or more, and a depth of the compression stress layer is 10 μ

m or more.

6. A tempered glass substrate comprising the tempered glass according to claim 1.

7. The tempered glass substrate according to claim 6, wherein the tempered glass is formed into a plate shape by an overflow down-draw method.

8. The tempered glass substrate according to claim 6, wherein the tempered glass substrate has an unpolished surface.

9. The tempered glass substrate according to claim 6, wherein the tempered glass substrate has a liquidus temperature of 1075°

C. or lower.

10. The tempered glass substrate according to claim 6, wherein the tempered glass substrate is formed of a glass having a liquidus viscosity of 10^4.0 dPa·

s or more.

11. The tempered glass substrate according to claim 6, which is used for a touch panel display.

12. The tempered glass substrate according to claim 6, which is used for a cover glass of a cellular phone.

13. The tempered glass substrate according to claim 6, which is used for a cover glass of a solar cell.

14. The tempered glass substrate according to claim 6, which is used as a protective member of a display.

21. The tempered glass according to claim 2, wherein an average breaking stress is 300 MPa or more, and a Weibull coefficient is 15 or more.

22. The tempered glass according to claim 2, wherein a compression stress of the surface is 300 MPa or more, and a depth of the compression stress layer is 10 μ

m or more.

23. A tempered glass substrate comprising the tempered glass according to claim 2.

15. A glass comprising, in terms of mol %, 40 to 80% of SiO₂, 5 to 15% of Al₂O₃, 0 to 8% of B₂O₃, 0 to 10% of Li₂O, 5 to 20% of Na₂O, 0.5 to 20% of K₂O, 0 to 10% of MgO, and 8 to 16.5% of Al₂O₃+MgO, wherein the glass has, in terms of a molar ratio, a (Li₂O+Na₂O+K₂O)/Al₂O₃ ratio of 1.4 to 3, an Na₂O/Al₂O₃ ratio of 1 to 3, and an MgO/Al₂O₃ ratio of 0 to 1, and is substantially free of As₂O₃, PbO, and F.

16. The glass according to claim 15, comprising 0.01 to 6% of SnO₂.

17. A method of producing a tempered glass substrate, comprising the steps of:

melting a glass raw material blended so as to have a glass composition comprising, in terms of mol %, 40 to 80% of SiO₂, 5 to 15% of Al₂O₃, 0 to 8% of B₂O₃, 0 to 10% of Li₂O, 5 to 20% of Na₂O, 0.5 to 20% of K₂O, 0 to 10% of MgO, and 8 to 16.5% of Al₂O₃+MgO, wherein the glass has, in terms of a molar ratio, a (Li₂O+Na₂O+K₂O)/Al₂O₃ ratio of 1.4 to 3, an Na₂O/Al₂O₃ ratio of 1 to 3, and an MgO/Al₂O₃ ratio of 0 to 1, and is substantially free of As₂O₃, PbO, and F;

forming the glass into a plate shape; and

subjecting the glass to an ion exchange treatment, to thereby form a compression stress layer on a surface of the glass.

18. The method of producing a tempered glass substrate according to claim 17, wherein the tempered glass substrate comprises 0.01 to 6% of SnO₂.

19. The method of producing a tempered glass substrate according to claim 17, wherein the glass is formed into a plate shape by a down-draw method.

20. The method of producing a tempered glass substrate according to claim 17, wherein the glass is formed into a plate shape by an overflow down-draw method.

24. The method of producing a tempered glass substrate according to claim 18, wherein the glass is formed into a plate shape by an overflow down-draw method.