Zirconia compatible, ion exchangeable glass with high damage resistance

Patent metadata

Field	Value
Publication number	US-9822032-B2
Application number	US-201514591361-A
Country	US
Kind code	B2
Filing date	Jan 7, 2015
Priority date	May 31, 2012
Publication date	Nov 21, 2017
Grant date	Nov 21, 2017

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, B 2 O 3 , 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 10 kilogram force (kgf).

First claim

The invention claimed is:

1. A glass comprising:
66-74 mol % SiO 2 ;
9-20 mol % Na 2 O;
9-22 mol % Al 2 O 3 ;
at least 2.7 mol % B 2 O 3 ;
at least 0.1 mol % of at least one of MgO and ZnO,
wherein R 2 O(mol %)+CaO(mol %)+SrO(mol %)+BaO(mol %)−Al 2 O 3 (mol %)−B 2 O 3 (mol %)<0 mol %.

2. The glass of claim 1 wherein the glass comprises 3-4.5 mol % B 2 O 3 .

3. The glass of claim 1 wherein the glass comprises 2.7-4.5 mol % B 2 O 3 .

4. The glass of claim 1 wherein the glass comprises 3-10 mol % B 2 O 3 .

5. The glass of claim 1 wherein the glass comprises at least about 10 mol % R 2 O.

6. The glass of claim 1 wherein the glass is substantially free of Li 2 O.

7. The glass of claim 1 wherein the glass comprises at least one of CaO, BaO, and SrO.

8. The glass of claim 1 , wherein the glass comprises: from about 10 mol % to about 20 mol % Na 2 O; from 0 mol % to about 5 mol % K 2 O; 0 mol %≦MgO≦6 mol %; 0 mol % ≦ZnO≦6 mol %; and 0 mol %≦CaO(mol %)+SrO(mol %)+BaO(mol %)≦2 mol %.

9. The glass of claim 1 , wherein B 2 O 3 (mol %)-(R 2 O(mol%) - Al 2 O 3 (mol %))≦4.5 mol %.

10. The glass of claim 1 wherein B 2 O 3 (mol %)−(R 2 O(mol %)−Al 2 O 3 (mol %))≧3 mol %.

11. The glass of claim 1 wherein 3 mol %≦B 2 O 3 (mol %)−(R 2 O(mol %)−Al 2 O 3 (mol %))≦4.5 mol %.

12. The glass of claim 1 wherein the glass has a zirconia breakdown temperature that is equal to the temperature at which the glass has a viscosity in a range from about 30 kPoise to about 40 kPoise.

13. The glass of claim 1 , wherein the glass contains less than about one inclusion per kilogram of glass, the inclusion having a diameter of at least 50 μm.

14. The glass of claim 1 wherein the glass is ion exchangeable.

15. 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 μm.

16. The glass of claim 1 wherein the compressive stress is at least about 800 MPa.

17. The glass of claim 1 wherein the glass is ion exchanged and has a Vickers crack initiation threshold in a range from about 20 kgf to about 30 kgf.

18. The glass of claim 1 , wherein the glass is ion exchanged and has a Vickers crack initiation threshold in a range from about 30 kgf to about 35 kgf.

Assignees

• Corning Inc

Inventors

• Dejneka Matthew John
• Ellison Adam James
• Mauro John Christopher

Classifications

• C03C3/087

  containing calcium oxide, e.g. common sheet or container glass · CPC title

• C03C3/091 Primary

  containing aluminium · CPC title

• C03C3/093 Primary

  containing zinc or zirconium · CPC title

• C03C21/005

  to introduce in the glass such metals or metallic ions as Ag, Cu · CPC title

• C03C21/002

  to perform ion-exchange between alkali ions (C03C21/005 takes precedence) · CPC title