Ion exchangeable glass with high crack initiation threshold

• US 9,156,724 B2
• Filed: 11/15/2012
• Issued: 10/13/2015
• Est. Priority Date: 11/16/2011
• Status: Active Grant

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Gross, Timothy Michael
• Primary Examiner(s): Green, Anthony J
• Assistant Examiner(s): Bolden, Elizabeth A
• Application Number:
  US13/678,013
• Publication Number:
  US 20130122284A1
• Time in Patent Office: 1,062 Days
• Field of Search: 501/63, 501/68, 501/69, 501/70, 501/66
• US Class Current: 1/1
• CPC Class Codes: C03C 14/006 the non-glass component being in the form of microcrystallites, e.g. of optically or electrically active material
• 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 2204/00 Glasses, glazes or enamels with special properties
• CPC Class Codes: C03C 3/04 containing silica
• CPC Class Codes: C03C 3/062 with less than 40% silica by weight
• CPC Class Codes: C03C 3/064 containing boron
• 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 3/087 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: C03C 3/097 containing phosphorus, niobium or tantalum
• CPC Class Codes: C03C 4/02 for coloured glass
• CPC Class Codes: C03C 4/18 for ion-sensitive glass
• CPC Class Codes: Y10T 428/265 1 mil or less
• CPC Class Codes: Y10T 428/315 Surface modified glass [e.g., tempered, strengthened, etc.]

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 % P₂O₅ and, when ion exchanged, have a Vickers indentation crack initiation load of at least about 7 kgf.

Claims

1. An alkali aluminosilicate glass comprising at least about 4% P₂O₅ and from 0 mol % to about 4 mol % B₂O₃, wherein the alkali aluminosilicate glass is Li₂O-free and wherein:

1.3<

[(P₂O₅+R₂O)/M₂O₃]≦

2.3;

 

 

ii.

where M₂O₃=Al₂O₃+B₂O₃, and R₂O 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<

[(P₂O₅+R₂O)/M₂O₃]≦

2.0.

3. The alkali aluminosilicate glass of claim 1, wherein the glass comprises less than 1 mol % K₂O.

4. The alkali aluminosilicate glass of claim 3, wherein the alkali aluminosilicate glass comprises 0 mol % K₂O.

5. The alkali aluminosilicate glass of claim 1, wherein the glass comprises less than 1 mol % B₂O₃.

6. The alkali aluminosilicate glass of claim 5, wherein the alkali aluminosilicate glass comprises 0 mol % B₂O₃.

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

m.

8. The alkali aluminosilicate glass of claim 7, wherein the glass is ion exchanged to a depth of layer of at least about 30 μ

m.

9. The alkali aluminosilicate glass of claim 7, 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.

10. The alkali aluminosilicate glass of claim 9, wherein the compressive stress is at least about 500 MPa.

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

12. The alkali aluminosilicate glass of claim 11, wherein the ion exchanged alkali aluminosilicate glass has a Vickers indentation crack initiation load of at least about 12 kgf.

13. The alkali aluminosilicate glass of claim 1, wherein the monovalent and divalent cation oxides are selected from the group consisting of Na₂O, K₂O, Rb₂O, Cs₂O, MgO, CaO, SrO, BaO, and ZnO.

14. The alkali aluminosilicate glass of claim 1, wherein the alkali aluminosilicate glass comprises from about 40 mol % to about 70 mol % SiO₂;

from about 11 mol % to about 25 mol % Al₂O₃;

from about 4 mol % to about 15 mol % P₂O₅; and

from about 13 mol % to about 25 mol % Na₂O.

15. The alkali aluminosilicate glass of claim 14, wherein the alkali aluminosilicate glass comprises from about 50 mol % to about 65 mol % SiO₂;

from about 14 mol % to about 20 mol % Al₂O₃;

from about 4 mol % to about 10 mol % P₂O₅; and

from about 14 mol % to about 20 mol % Na₂O.

16. The alkali aluminosilicate glass of claim 14, wherein the alkali aluminosilicate glass comprises less than 1 mol % K₂O.

17. The alkali aluminosilicate glass of claim 16, wherein the alkali aluminosilicate glass comprises 0 mol % K₂O.

18. The alkali aluminosilicate glass of claim 14, wherein the alkali aluminosilicate glass comprises less than 1 mol % B₂O₃.

19. The alkali aluminosilicate glass of claim 16, wherein the alkali aluminosilicate glass comprises 0 mol % B₂O₃.

20. 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<sup>−

10</sup> cm²/s at 410°

C.

21. The alkali aluminosilicate glass of claim 20, wherein the potassium/sodium interdiffusion coefficient is in a range from about 2.4×

10<sup>−

10</sup> cm²/s up to about 1.5×

10<sup>−

9</sup> cm²/s at 410°

C.