Ion exchangeable glass with high crack initiation threshold

Patent metadata

Field	Value
Publication number	US-9783453-B2
Application number	US-201514842122-A
Country	US
Kind code	B2
Filing date	Sep 1, 2015
Priority date	Nov 16, 2011
Publication date	Oct 10, 2017
Grant date	Oct 10, 2017

Abstract

Alkali aluminosilicate glasses that are resistant to damage due to sharp impact and capable of fast ion exchange are provided. The glasses comprise at least 4 mol % P 2 O 5 and, when ion exchanged, have a Vickers indentation crack initiation load of at least about 7 kgf.

First claim

The invention claimed is:

1. An alkali aluminosilicate glass comprising MgO, from about 40 mol % to about 70 mol % SiO 2 , from about 4 mol % to about 15 mol % P 2 O 5 , about 11 mol % to about 25 mol % Al 2 O 3 , about 13 mol % to about 20 mol % Na 2 O, and less than 1 mol % K 2 O, wherein:
i. the alkali aluminosilicate glass is free of Li 2 O; and
ii. 1.3<[(P 2 O 5 +R 2 O)/M 2 O 3 ]≦2.3, where M 2 O 3 =Al 2 O 3 +B 2 O 3 , and R 2 O is the sum of monovalent cation oxides present in the alkali aluminosilicate glass.

2. The alkali aluminosilicate glass of claim 1 , wherein the glass satisfies:
1.5<[(P 2 O 5 +R 2 O)/M 2 O 3 ]≦2.0.

3. The alkali aluminosilicate glass of claim 1 , wherein the alkali aluminosilicate glass comprises 0 mol % K 2 O.

4. The alkali aluminosilicate glass of claim 1 , wherein the monovalent cation oxides are selected from the group consisting of Na 2 O, K 2 O, Rb 2 O, and Cs 2 O.

5. The alkali aluminosilicate glass of claim 1 , wherein the alkali aluminosilicate glass comprises from about 50 mol % to about 65 mol % SiO 2 ; from about 14 mol % to about 20 mol % Al 2 O 3 ; from about 4 mol % to about 10 mol % P 2 O 5 ; and from about 14 mol % to about 20 mol % Na 2 O.

6. The alkali aluminosilicate glass of claim 1 , comprises less than 1 mol % B 2 O 3 .

7. The alkali aluminosilicate glass of claim 6 , wherein the alkali aluminosilicate glass comprises 0 mol % B 2 O 3 .

8. The alkali aluminosilicate glass of claim 1 , wherein the alkali aluminosilicate glass has a potassium/sodium interdiffusion coefficient of at least about 2.4×10 −10 cm 2 /s at 410° C.

9. The alkali aluminosilicate glass of claim 8 , wherein the potassium/sodium interdiffusion coefficient is in a range from about 2.4×10 −10 cm 2 /s up to about 1.5×10 −9 cm 2 /s at 410° C.

10. The alkali aluminosilicate glass of claim 1 , wherein the glass is ion exchanged to a depth of layer of at least about 10 μm.

11. The alkali aluminosilicate glass of claim 10 , wherein the alkali aluminosilicate glass has a compressive layer extending from a surface of the glass to the depth of layer, and wherein the compressive layer is under a compressive stress of at least about 300 MPa.

12. The alkali aluminosilicate glass of claim 10 , wherein the ion exchanged alkali aluminosilicate glass has a Vickers indentation crack initiation load of at least about 7 kgf.

13. The alkali aluminosilicate glass of claim 12 , wherein the ion exchanged alkali aluminosilicate glass has a Vickers indentation crack initiation load of at least about 12 kgf.

14. An electronic device comprising the alkali aluminosilicate glass of claim 1 .

Assignees

• Corning Inc

Inventors

• Gross Timothy Michael

Classifications

• C03C2204/00

  Glasses, glazes or enamels with special properties · CPC title

• C03C4/02

  for coloured glass · CPC title

• C03C14/006

  the non-glass component being in the form of microcrystallites, e.g. of optically or electrically active material · CPC title

• C03C3/087

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

• C03C21/002

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