Strengthened glass with deep depth of compression

Patent metadata

Field	Value
Publication number	US-9567254-B2
Application number	US-201514723815-A
Country	US
Kind code	B2
Filing date	May 28, 2015
Priority date	Feb 24, 2014
Publication date	Feb 14, 2017
Grant date	Feb 14, 2017

Abstract

Chemically strengthened glass articles having at least one deep compressive layer extending from a surface of the article to a depth of layer DOL of about 130 μm up to about 175 μm or, alternatively, to a depth of compression (DOC) in a range from about 90 μm to about 120 μm within the article. The compressive layer has a stress profile that includes a first substantially linear portion extending from a relatively shallow depth to the DOL or DOC and a second portion extending from the surface to the shallow depth. The second portion is substantially linear at a depth from 0 μm to 5 μm and has a steeper slope than that of the first portion of the profile. Methods of achieving such stress profiles are also described.

First claim

The invention claimed is:

1. A glass article, the glass article having a compressive region extending from a surface of the glass article to a depth of layer DOL in a range from about 130 μm to about 175 μm, the compressive region having a compressive stress profile, the compressive stress profile comprising:
a. a first portion extending from at least a first depth D 1 to the depth of layer DOL, wherein a compressive stress CS 1 at a depth d in the first portion is given by the expression 200 MPa−d·1.54 MPa/μm≦CS 1 ≦260 MPa−d·1.49 MPa/μm, where d is expressed in microns (μm) and d>D 1 ; and
b. a second portion extending from the surface to the first depth D 1 , where 10 μm≦D 1 ≦13 μm, the second portion having a maximum compressive stress CS 2 at the surface in a range from about 700 MPa to about 925 MPa and being substantially linear and having a slope m 2 from the surface to a depth of about 5 μm, wherein −74.00 MPa/μm≦m 2 ≦−70.00 MPa/μm.

2. The glass article of claim 1 , wherein 185 MPa≦CS 1 ≦240 MPa at D 1 .

3. The glass article of claim 1 , wherein the glass article has a thickness t in a range from about 0.75 mm up to about 0.85 mm.

4. The article of claim 3 , wherein the glass article exhibits a break load of at least 27 kgf when subjected to abraded ring-on-ring testing.

5. The glass article of claim 1 , wherein the glass article comprises an alkali aluminosilicate glass, the alkali aluminosilicate glass comprising at least about 4 mol % P 2 O 5 and from 0 mol % to about 5 mol % B 2 O 3 , wherein 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.

6. The glass article of claim 4 , wherein the alkali aluminosilicate glass comprises up to about 10 mol % Li 2 O.

7. The glass article of claim 4 , wherein the glass is lithium-free.

8. The glass article of claim 4 , wherein the glass comprises from about 40 mol % to about 70 mol % SiO 2 ; from about 11 mol % to about 25 mol % Al 2 O 3 ; from 0 mol % to about 5 mol % B 2 O 3 ; from about 4 mol % to about 15 mol % P 2 O 5 ; from about 13 mol % to about 25 mol % Na 2 O; and from 0 mol % to about 1 mol % K 2 O.

9. The glass article of claim 8 , wherein 11 mol %≦M 2 O 3 ≦30 mol %.

10. The glass article of claim 8 , wherein R x O is the sum of alkali metal oxides, alkaline earth metal oxides, and transition metal monoxides present in the glass, and wherein 13 mol %≦R x O≦30 mol %.

11. The glass article of claim 8 , wherein the alkali aluminosilicate glass comprises 3 mol % or less of one or more of TiO 2 , MnO, Nb 2 O 5 , MoO 3 , Ta 2 O 5 , WO 3 , ZrO 2 , Y 2 O 3 , La 2 O 3 , HfO 2 , CdO, SnO 2 , Fe 2 O 3 , CeO 2 , As 2 O 3 , Sb 2 O 3 , Cl, and Br.

12. The glass article of claim 1 , wherein the first portion is linear at a depth d and wherein the compressive stress CS 1 , extrapolated from the depth d to zero depth below the surface, is in a range from about 200 MPa to about 260 MPa at zero depth.

13. The glass article of claim 1 , wherein the glass article has at least a 50% survival rate when dropped in an inverted ball drop test from a height of about 80 cm onto a drop surface.

14. The glass article of claim 1 , wherein the glass article forms at least a portion of a cover glass for a consumer electronic device, the consumer electronic device comprising a housing; electrical components provided at least partially internal to the housing, the electrical components including at least a controller, a memory, and a display, the display being provided at or adjacent to a front surface of the housing; wherein the cover glass is provided at or over the front surface of the housing and over the display.

15. An alkali aluminosilicate glass, the alkali aluminosilicate glass comprising at least about 4 mol % P 2 O 5 and from 0 mol % to about 5 mol % B 2 O 3 , wherein 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, the alkali aluminosilicate glass having a compressive region extending from a surface of the glass article to a depth of layer DOL in a range from 130 μm to 175 μm, the compressive region having a maximum compressive stress CS 2 in a range from about 700 MPa to about 925 MPa at the surface and a compressive stress profile, the compressive stress profile comprising:
a. a first portion extending from at least a first depth D 1 to the depth of layer DOL, wherein a compressive stress CS 1 at a depth d in the first portion is given by the expression 200 MPa−d·1.54 MPa/μm≦CS 1 ≦260 MPa−d·1.49 MPa/μm, where d is expressed in microns (μm) and d>D 1 ; and
b. a second portion extending from the surface to the first depth D 1 , where 10 μm≦D 1 ≦13 μm, the second portion being substantially linear and having a slope m 2 from the surface to a depth of about 5 μm, wherein −74.00 MPa/μm≦m 2 ≦−70 MPa/μm.

16. The alkali aluminosilicate glass of claim 15 , wherein the alkali aluminosilicate glass has a thickness t in a range from about 0.75 mm up to about 0.85 mm.

17. The alkali aluminosilicate glass of claim 15 , wherein 185 MPa≦CS 2 ≦240 MPa at D 1 .

18. The alkali aluminosilicate glass of claim 15 , wherein the glass is lithium-free.

19. The alkali aluminosilicate glass of claim 15 , wherein the glass comprises from about 40 mol % to about 70 mol % SiO 2 ; from about 11 mol % to about 25 mol % Al 2 O 3 ; from 0 mol % to about 5 mol % B 2 O 3 ; from about 4 mol % to about 15 mol % P 2 O 5 ; from about 13 mol % to about 25 mol % Na 2 O; and from 0 mol % to about 1 mol % K 2 O.

20. The alkali aluminosilicate glass of claim 19 , wherein 11 mol %≦M 2 O 3 ≦30 mol %.

21. The alkali aluminosilicate glass of claim 19 , wherein R x O is the sum of alkali metal oxides, alkaline earth metal oxides, and transition metal monoxides present in the glass, and wherein 13 mol %≦R x O≦30 mol %.

22. The alkali aluminosilicate glass of claim 19 , wherein the alkali aluminosilicate glass comprises 3 mol % or less of one or more of TiO 2 , MnO, Nb 2 O 5 , MoO 3 , Ta 2 O 5 , WO 3 , ZrO 2 , Y 2 O 3 , La 2 O 3 , HfO 2 , CdO, SnO 2 , Fe 2 O 3 , CeO 2 , As 2 O 3 , Sb 2 O 3 , Cl, and Br.

23. The alkali aluminosilicate glass of claim 15 , wherein the first portion is linear at a depth d, and wherein the compressive stress CS 1 , extrapolated from the depth d to zero depth below the surface, is in a range from about 200 MPa to about 260 MPa at zero depth.

24. The alkali aluminosilicate glass of claim 15 , wherein the glass article has at least a 50% survival rate when dropped in an inverted ball drop test from a height of about 80 cm onto a drop surface.

25. A glass article, the glass article having a compressive region extending from a surface of the glass article to a depth of compression DOC in a range from 90 μm to 120 μm and having a maximum compressive stress CS 2 in a range from about 700 MPa to about 925 MPa at the surface and a compressive stress profile, the compressive stress profile comprising:
a. a first portion extending from at least a first depth D 1 to the depth of compression DOC and having a slope m 1 , where −2.89 MPa/μm≦m 1 ≦−1.67 MPa/μm; and
b. a second portion extending from the surface to the first depth D 1 , where 10 μm≦D 1 ≦13 μm, the second portion being substantially linear and having a slope m 2 from the surface to a depth of about 5 μm, wherein −55 MPa/μm≦m

Assignees

• Corning Inc

Inventors

• Amin Jaymin
• Egboiyi Benedict Osobomen
• Oram Pascale
• Pesansky Jonathan David
• Reiman Kevin Barry
• Roussev Rostislav Vatchev
• Schneider Vitor Marino
• Strines Brian Paul

Classifications

• C03C21/002 Primary

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

• C03C3/091

  containing aluminium · CPC title

• C03C4/18 Primary

  for ion-sensitive glass · CPC title

• C03C21/00

  Treatment of glass, not in the form of fibres or filaments, by diffusing ions or metals in the surface · CPC title

• C03C3/093

  containing zinc or zirconium · CPC title