ION EXCHANGEABLE GLASS WITH HIGH DAMAGE RESISTANCE

• US 20140106172A1
• Filed: 05/28/2013
• Published: 04/17/2014
• Est. Priority Date: 05/31/2012
• Status: Active Grant

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Dejneka, Matthew John, Ellison, Adam James, Mauro, John Christopher
• Granted Patent: US 9,517,967 B2
• Time in Patent Office: Days
• US Class Current: 428/410
• CPC Class Codes: C03C 21/00 Treatment of glass, not in the form of fibres or filaments, by diffusing ions or metals in the surface
• CPC Class Codes: C03C 21/002 to perform ion-exchange between alkali ions C03C21/005 takes precedence
• CPC Class Codes: C03C 3/091 containing aluminium
• CPC Class Codes: C03C 3/093 containing zinc or zirconium
• CPC Class Codes: C03C 4/18 for ion-sensitive glass
• CPC Class Codes: Y10T 428/315 Surface modified glass [e.g., tempered, strengthened, etc.]

Abstract

An ion exchangeable glass having a high degree of resistance to damage caused by abrasion, scratching, indentation, and the like. The glass comprises alumina, B₂O₃, and alkali metal oxides, and contains boron cations having three-fold coordination. The glass, when ion exchanged, has a Vickers crack initiation threshold of at least about 30 kilogram force.

Claims

1. A glass comprising:

a. at least about 50 mol % SiO₂;

b. at least about 10 mol % R₂O, wherein R₂O comprises Na₂O;

c. Al₂O₃, wherein −

0.5 mol %≦

Al₂O₃ (mol %)−

R₂O(mol %)≦

2 mol %; and

d. B₂O₃, wherein B₂O₃ (mol %)−

(R₂O(mol %)−

Al₂O₃ (mol %))≧

4.5 mol %, and wherein the glass is ion exchangeable.

2. The glass of claim 1, wherein the glass comprises:

at least about 50 mol % SiO₂, from about 12 mol % to about 22 mol % Al₂O₃;

from about 4.5 mol % to about 10 mol % B₂O₃;

from about 10 mol % to about 20 mol % Na₂O;

from 0 mol % to about 5 mol % K₂O;

at least about 0.1 mol % MgO, ZnO, or combinations thereof, wherein 0 mol %≦

MgO≦

6 and 0≦

ZnO≦

6 mol %; and

, optionally, at least one of CaO, BaO, and SrO, wherein 0 mol %≦

CaO+SrO+BaO≦

2 mol %.

3. The glass of claim 2, wherein the glass comprises from about 60 to 66 mol % SiO₂.

4. The glass of claim 1, wherein the glass comprises at least about 0.1 mol % of at least one of MgO and ZnO.

5. The glass of claim 1, wherein the glass comprises greater than 4.5 mol % B₂O₃ in which boron cations are three-fold coordinated.

6. The glass of claim 1, wherein the glass is ion exchanged and has a layer under a compressive stress of at least about 600 MPa, the layer extending from a surface of the glass into the glass to a depth of layer of at least about 30 μ

m.

7. The glass of claim 6, wherein the compressive stress is at least about 800 MPa.

8. The glass of claim 6, wherein the glass has a Vickers crack initiation threshold of at least about 30 kgf.

9. A glass comprising:

at least about 50 mol % SiO₂;

at least about 10 mol % R₂O, wherein R₂O comprises Na₂O;

Al₂O₃; and

B₂O₃, wherein B₂O₃ (mol %)−

(R₂O(mol %)−

Al₂O₃ (mol %))≧

4.5 mol %, and wherein the glass has a zircon breakdown temperature at which the viscosity of the glass is greater than about 40 kPoise.

10. The glass of claim 9, wherein the glass comprises:

at least about 50 mol % SiO₂, from about 12 mol % to about 22 mol % Al₂O₃;

from about 4.5 mol % to about 10 mol % B₂O₃;

from about 10 mol % to about 20 mol % Na₂O;

from 0 mol % to about 5 mol % K₂O;

at least about 0.1 mol % MgO, ZnO, or combinations thereof, wherein 0 mol %≦

MgO≦

6 and 0≦

ZnO≦

6 mol %; and

, optionally, at least one of CaO, BaO, and SrO, wherein 0 mol %≦

CaO+SrO+BaO<

2 mol %.

11. The glass of claim 10, wherein the glass comprises from about 60 to about 66 mol % SiO₂.

12. The glass of claim 9, wherein the glass comprises at least about 0.1 mol % of at least one of MgO and ZnO.

13. The glass of claim 9, wherein the glass comprises greater than about 4.5 mol % B₂O₃ in which boron cations are three-fold coordinated.

14. The glass of claim 9, wherein the glass is ion exchanged and has a layer under a compressive stress of at least about 600 MPa, the layer extending from a surface of the glass into the glass to a depth of layer of at least about 30 μ

m.

15. The glass of claim 14, wherein the compressive stress is at least about 800 MPa.

16. The glass of claim 14, wherein the glass has a Vickers crack initiation threshold of at least about 30 kgf.

17. A glass, wherein the glass is ion exchanged and has a Vickers crack initiation threshold of at least about 30 kgf, the glass comprising:

a. at least about 50 mol % SiO₂;

b. at least about 10 mol % R₂O, wherein R₂O comprises Na₂O;

c. Al₂O₃, wherein −

0.5 mol %≦

Al₂O₃ (mol %)−

R₂O(mol %)≦

2 mol %; and

d. B₂O₃, wherein B₂O₃ (mol %)−

(R₂O(mol %)−

Al₂O₃ (mol %))≧

4.5 mol %.

18. The glass of claim 17, wherein the glass comprises:

at least about 50 mol % SiO₂, from about 12 mol % to about 22 mol % Al₂O₃;

from about 4.5 mol % to about 10 mol % B₂O₃;

from about 10 mol % to about 20 mol % Na₂O;

from 0 mol % to about 5 mol % K₂O;

at least about 0.1 mol % MgO, ZnO, or combinations thereof, wherein 0 mol %≦

MgO≦

6 and 0≦

ZnO≦

6 mol %; and

, optionally, at least one of CaO, BaO, and SrO, wherein 0 mol %≦

CaO+SrO+BaO≦

2 mol %.

19. The glass of claim 18, wherein the glass comprises from about 66 to about 66 mol % SiO₂.

20. The glass of claim 17, wherein the glass comprises at least about 0.1 mol % of at least one of MgO and ZnO.

21. The glass of claim 17, wherein the glass comprises greater than about 4.5 mol % B₂O₃ in which boron cations are three-fold coordinated.

22. The glass of claim 17, wherein the glass has a layer under a compressive stress of at least about 600 MPa, the layer extending from a surface of the glass into the glass to a depth of layer of at least about 30 μ

m.

23. The glass of claim 22, wherein the compressive stress is at least about 800 MPa.

24. The glass of claim 17, wherein the Vickers crack initiation threshold is in a range from about 30 kgf to about 35 kgf.