Ion exchangeable glass with high compressive stress

• US 9,290,413 B2
• Filed: 06/26/2012
• Issued: 03/22/2016
• Est. Priority Date: 07/01/2011
• Status: Active Grant

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Dejneka, Matthew John, Ellison, Adam James, Mauro, John Christopher
• Primary Examiner(s): SAMPLE, DAVID R
• Application Number:
  US13/533,298
• Publication Number:
  US 20130004758A1
• Time in Patent Office: 1,365 Days
• Field of Search: 428/410
• US Class Current: 1/1
• CPC Class Codes: C03C 21/002 to perform ion-exchange between alkali ions C03C21/005 takes precedence
• 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 3/093 containing zinc or zirconium
• CPC Class Codes: Y10T 428/315 Surface modified glass [e.g., tempered, strengthened, etc.]

Abstract

An aluminosilicate glass article having a high compressive stress layer. The glass article comprises at least about 50 mol % SiO₂ and at least about 11 mol % Na₂O, and has a layer under a compressive stress of at least about 900 MPa and the depth of layer that extends at least about 30 μm from the surface of the glass article into the glass. A method of making such a glass article is also provided.

Claims

1. A glass article having a surface and a layer under compressive stress extending from the surface to a depth of layer wherein the compressive stress CS is at least about 900 Mpa and the depth of layer DOL is at least about 30 μ

m, wherein the glass article comprises;

at least about 50 mol % SiO₂;

from about 7 mol % to about 26 mol % Al₂O₃;

from about 11 mol % to about 25 mol % Na₂O;

from 0 mol % to about 9 mol % B₂O₃;

from 0 mol % to 2.5 mol % K₂O;

from 0 mol % to about 8.5 mol % MgO; and

from 0 mol % to 1.5 mol % CaO;

wherein the glass article exhibits a CS criterion defined by the equation −

340+27.1*Al₂O₃−

28.7*B₂O₃+15.6*Na₂O−

61.4*K₂O+8.1*(MgO+ZnO)≧

40 mol % and a compensation criterion defined by the equation 0.7 mol %≦

Na₂O+K₂O−

Al₂O₃−

MgO−

ZnO≦

2 mol %.

2. The glass article of claim 1, wherein the compensation criterion is 1.0 mol %≦

Na₂O+K₂O−

Al₂O₃−

MgO−

ZnO≦

2 mol %.

3. The glass article of claim 1, wherein the CS criterion defined by the equation −

340+27.1*Al₂O₃−

28.7*B₂O₃+15.6*Na₂O −

61.4*K₂O+8.1*(MgO+ZnO)≧

80 mol %.

4. The glass article of claim 3, wherein the CS criterion defined by the equation −

340+27.1*Al₂O₃−

28.7*B₂O₃+15.6*Na₂O−

61.4*K₂O +8.1*(MgO+ZnO)≧

100 mol %.

5. The glass article of claim 1, wherein the glass article further comprises 0-0.1 mol % of one or more of ZrO₂, TiO₂, Fe₂O₃, Cr₂O₃, Co2O₃, or V₂O₃.

6. The glass article of claim 1, wherein the glass article is substantially free of Li₂O.

7. The glass article of claim 1, wherein the glass article further comprises at least one fining agent selected from the group consisting of F, Cl, Br, I, As₂O₃, Sb₂O₃, CeO₂, SnO₂, and combinations thereof.

8. The glass article of claim 1, wherein the glass article has a thickness of up to about 1 mm.

9. The glass article of claim 1, wherein the glass article exhibits a load to failure of at least about 300 kgf.

10. The glass article of claim 1, wherein the DOL is at least about 40 μ

m.

11. The glass article of claim 1, wherein the CS is at least 1000 MPa.

12. The glass article of claim 1, wherein SiO₂+Al₂O₃+B₂O₃+Na₂O +K₂O+MgO+ZnO≧

95 mol %.

13. The glass article of claim 1, wherein Na₂O+Al₂O₃+MgO+ZnO>

25 mol %.

14. The glass article of claim 1, wherein the glass comprises greater than 0 to 8.5 mol % MgO.

15. The glass article of claim 1, wherein the glass comprises 0-0.1 mol % ZrO2.