STRENGTHENED GLASS WITH DEEP DEPTH OF COMPRESSION

• US 20150239775A1
• Filed: 10/31/2014
• Published: 08/27/2015
• Est. Priority Date: 02/24/2014
• Status: Active Grant

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Amin, Jaymin, Pesansky, Jonathan David, Reiman, Kevin Barry, Roussev, Rostislav Vatchev, Strines, Brian Paul, Egboiyi, Benedict Osobomen
• Granted Patent: US 10,118,858 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 3/085 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 3/095 containing rare earths
• CPC Class Codes: C03C 3/097 containing phosphorus, niobium or tantalum
• CPC Class Codes: C03C 4/18 for ion-sensitive glass
• CPC Class Codes: G06F 1/1637 Details related to the display arrangement, including those related to the mounting of the display in the housing
• CPC Class Codes: G06F 2200/1634 Integrated protective display lid, e.g. for touch-sensitive display in handheld computer
• CPC Class Codes: H04B 1/3827 Portable transceivers
• CPC Class Codes: Y10T 428/315 Surface modified glass [e.g., tempered, strengthened, etc.]

Abstract

Chemically strengthened glass articles having at least one deep compressive layer extending from a surface of the article to a depth of at least about 45 μm within the article are provided. In one embodiment, the compressive stress profile includes a single linear segment extending from the surface to the depth of compression DOC. Alternatively, the compressive stress profile includes two linear portions: the first portion extending from the surface to a relatively shallow depth and having a steep slope; and a second portion extending from the shallow depth to the depth of compression. The strengthened glass has a 60% survival rate when dropped from a height of 80 cm in an inverted ball drop test and an equibiaxial flexural strength of at least 10 kgf as determined by abraded ring-on-ring testing. Methods of achieving such stress profiles are also described.

Claims

1. A glass article, the glass article having thickness t and a compressive region having a compressive stress CS of from about 100 MPa up to about 1200 MPa at a surface of the glass article, wherein:

a. the compressive region extends from the surface to a depth of compression DOC, wherein DOC≧

0.1·

t when t<

0.5 mm and DOC≧

50 μ

m when t≧

0.5 mm, and wherein the compressive region has a compressive stress profile; and

b. the compressive region has a compressive stress profile having a first portion having a first slope, wherein the first slope is less than or equal to about −

2 MPa/μ

m and greater than or equal to about −

8 MPa/μ

m and, optionally, a second portion extending from the surface to at least about 3 μ

m and up to about 15 μ

m within the glass article and having a second slope, wherein the second slope is less than or equal to −

40 MPa/μ

m and greater than or equal to −

200 MPa/μ

m.

2. The glass article of claim 1, wherein the first portion extends from the surface to the depth of compression DOC.

3. The glass article of claim 2, wherein the first slope is less than or equal to about −

3 MPa/μ

m and greater than or equal to about −

6 MPa/μ

m.

4. The glass article of claim 1, wherein DOC≧

0.11·

t when t<

0.5 mm and 55 μ

m DOC≦

100 μ

m when t≧

0.5 mm.

5. The glass article of claim 1, wherein the compressive stress profile comprises the second portion, and wherein the second slope is less than or equal to −

40 MPa/μ

m and greater than or equal to −

120 MPa/μ

m.

6. The glass article of claim 1, wherein the thickness t is in a range from about 0.15 mm up to about 2.0 mm.

7. The glass article of claim 1, wherein the glass article comprises an alkali aluminosilicate glass.

8. The glass article of claim 7, wherein the alkali aluminosilicate glass further comprises up to about 10 mol % Li₂O.

9. The glass article of claim 7, where the alkali aluminosilicate glass comprises at least about 4 mol % P₂O₅ and from 0 mol % to about 4 mol % B₂O₃, wherein 1.3<

[(P₂O₅+R₂O)/M₂O₃]≦

2.3, where M₂O₃═

Al₂O₃+B₂O₃, and R₂O is the sum of monovalent cation oxides present in the alkali aluminosilicate glass.

10. The glass article of claim 7, wherein the glass consists essentially of 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;

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

from about 13 to about 30 mol % R_xO, wherein R_xO is the sum of the alkali metal oxides, alkaline earth metal oxides, and transition metal monoxides present in the glass;

from about 11 to about 30 mol % M₂O₃, where M₂O₃═

Al₂O₃+B₂O₃;

from 0 mol % to about 1 mol % K₂O;

from 0 mol % to about 4 mol % B₂O₃, and 3 mol % or less of one or more of TiO₂, MnO, Nb₂O₅, MoO₃, Ta₂O₅, WO₃, ZrO₂, Y₂O₃, La₂O₃, HfO₂, CdO, SnO₂, Fe₂O₃, CeO₂, As₂O₃, Sb₂O₃, Cl, and Br; and

1.3<

[(P₂O₅+R₂O)/M₂O₃]≦

2.3, where R₂O is the sum of monovalent cation oxides present in the glass.

11. The alkali aluminosilicate glass of claim 7, wherein the glass is lithium-free.

12. The glass article of claim 1, wherein the compressive stress profile comprises the second portion, and wherein the compressive stress CS at the surface is in a range from about 700 MPa to about 1200 MPa.

13. The glass article of claim 1, wherein at least one of the first portion and the second portion is substantially linear.

14. The glass article of claim 1, wherein the glass article has at least a 60% survival rate when subjected to an inverted ball drop test from a height of about 80 cm onto a drop surface.

15. The glass article of claim 1, wherein the glass article has an equibiaxial flexural strength in a range from about 10 kgf to about 50 kgf as determined by abraded ring-on-ring testing.

16. A glass article, the glass article having a thickness t and a compressive layer having a compressive stress CS of in a range from about 700 MPa up to about 1200 MPa at a surface of the glass article, wherein:

a. the compressive layer extends from the surface to a depth of compression DOC, wherein DOC≧

0.1·

t when t<

0.5 mm and DOC≧

50 μ

m when t≧

0.5 mm, and wherein the compressive layer has a compressive stress profile; and

b. the compressive stress profile comprises;

i. a first portion b extending from the surface to a depth d_c and having a slope m_b, wherein 3 μ

m≦

d_c≦

15 μ

m and −

40 MPa/μ

m m_b≧

−

0.200 MPa/μ

m; and

ii. a second portion c extending from d_c up to the depth of compression DOC and having a slope m_c, wherein −

2 MPa/μ

m≧

m_c≧

−

8 MPa/μ

m.

17. The glass article of claim 16, wherein −

40 MPa/μ

m≧

m_b≧

−

120 MPa/μ

m.

18. The glass article of claim 16, wherein thickness t is in a range from about 0.15 mm up to about 2.0 mm.

19. The glass article of claim 16, wherein the glass article comprises an alkali aluminosilicate glass.

20. The glass article of claim 19, wherein the alkali aluminosilicate glass further comprises up to about 10 mol % Li₂O.

21. The glass article of claim 19, wherein the alkali aluminosilicate glass comprises at least about 4 mol % P₂O₅ and from 0 mol % to about 4 mol % B₂O₃, wherein 1.3<

[(P₂O₅+R₂O)/M₂O₃]≦

2.3, where M₂O₃═

Al₂O₃+B₂O₃, and R₂O is the sum of monovalent cation oxides present in the alkali aluminosilicate glass.

22. The glass article of claim 16, wherein the glass article has at least a 60% survival rate when subjected to an inverted ball drop test from a height of about 80 cm onto a drop surface.

23. The glass article of claim 16, wherein the glass article has an equibiaxial flexural strength in a range from about 10 kgf up to about 50 kgf as determined by abraded ring-on-ring testing.

24. A glass article, the glass article having thickness t and a compressive region having a compressive stress CS in a range from about 100 MPa to about 400 MPa at a surface of the glass article, wherein:

a. the compressive region extends from the surface to a depth of compression DOC and has a compressive stress profile, wherein DOC≧

0.1·

t when t<

0.5 mm and DOC≧

50 μ

m when t≧

0.5 mm; and

b. the compressive stress profile has a portion a extending from the surface to a depth d_a and a slope m_a, wherein −

2 MPa/μ

m≧

m_a≧

−

8 MPa/μ

m.

25. The glass article of claim 24, wherein the depth d_a is equal to the depth of compression DOC.

26. The glass article of claim 24, wherein −

3 MPa/μ

m≧

m_a≧

−

6 MPa/μ

m.

27. The glass article of claim 24, wherein the thickness t is in a range from about 0.15 mm up to about 2.0 mm.

28. The glass article of claim 24, wherein the glass article comprises an alkali aluminosilicate glass.

29. The glass article of claim 28, wherein the alkali aluminosilicate glass further comprises up to about 10 mol % Li₂O.

30. The glass article of claim 28, wherein the alkali aluminosilicate glass comprises at least about 4 mol % P₂O₅ and from 0 mol % to about 4 mol % B₂O₃, wherein 1.3<

[(P₂O₅+R₂O)/M₂O₃]≦

2.3, where M₂O₃═

Al₂O₃+B₂O₃, and R₂O is the sum of monovalent cation oxides present in the alkali aluminosilicate glass.

31. The glass article of claim 24, wherein the glass article has an equibiaxial flexural strength in a range from about 10 kgf up to 50 kgf as determined by abraded ring-on-ring testing.

32. A strengthened glass, the strengthened glass having a thickness t, an inner region under a central tension CT, and at least one compressive layer under a compressive stress CS, the compressive stress layer extending from a surface of the glass to a depth of compression DOC≧

0.1·

t when t<

0.5 mm and DOC≧

50 μ

m when t≧

0.5 mm, and being adjacent to the inner region, wherein the strengthened glass has at least a 60% survival rate when dropped in an inverted ball drop test from a height of about 80 cm onto the surface of the glass.

33. The strengthened glass of claim 32, wherein the compressive layer has a compressive stress CS_s in a range from about 700 MPa to about 1200 MPa at a surface of the glass article, wherein the compressive layer has a compressive stress profile comprising:

a. a first portion b extending from the surface to a depth d_c and having a slope m_b, wherein 3 μ

m≦

d_c≦

8 μ

m and −

40 MPa/μ

m≧

m_b≧

−

200 MPa/μ

m; and

b. a second portion c extending from about d_c to the depth of compression DOC and having a slope m_c, wherein −

2 MPa/μ

m≧

m_c≧

−

8 MPa/μ

m.

34. The strengthened glass of claim 33, wherein −

40 MPa/μ

m≧

m_b≧

−

120 MPa/μ

m.

35. The strengthened glass of claim 32, wherein the thickness t is in a range from about 0.15 mm up to about 2.0 mm.

36. The strengthened glass of claim 32, wherein the strengthened glass comprises an alkali aluminosilicate glass.

37. The strengthened glass of claim 36, wherein the alkali aluminosilicate glass comprises at least about 4 mol % P₂O₅ and from 0 mol % to about 4 mol % B₂O₃, wherein 1.3<

[(P₂O₅+R₂O)/M₂O₃]≦

2.3, where M₂O₃═

Al₂O₃+B₂O₃, and R₂O is the sum of monovalent cation oxides present in the alkali aluminosilicate glass.

38. The strengthened glass of claim 36, wherein the alkali aluminosilicate glass further comprises up to about 10 mol % Li₂O.

39. The strengthened glass of claim 32, wherein the strengthened glass has an equibiaxial flexural strength in a range from about 10 kgf to about 50 kgf as determined by abraded ring-on-ring testing.

40. A strengthened glass, the strengthened glass having a thickness t, an inner region under a central tension CT, and at least one compressive stress layer under a compressive stress CS, the compressive stress layer extending from a surface of the glass to a depth of compression DOC, wherein DOC≧

0.1·

t when t<

0.5 mm and DOC≧

50 μ

m when t≧

0.5 mm, and being adjacent to the inner region, wherein the strengthened glass has an equibiaxial flexural strength of at least about 10 kgf as determined by abraded ring-on-ring testing.

41. The strengthened glass of claim 40, wherein the compressive layer has a compressive stress CS, in a range from about 700 MPa to about 1200 MPa at a surface of the glass article, wherein the compressive layer has a compressive stress profile comprising:

a. a first portion b extending from the surface to a depth d_c and having a slope m_b, wherein 3 μ

m≦

d_c≦

15 μ

m and −

40 MPa/μ

m≧

m_b≧

−

200 MPa/μ

m; and

b. a second portion c extending from about d_c to the depth of compression DOC and having a slope m_c, wherein −

2 MPa/μ

m≧

m_c≧

−

8 MPa/μ

m.

42. The strengthened glass of claim 41, wherein −

40 MPa/μ

m≧

m_b−

120 MPa/μ

m.

43. The strengthened glass of claim 40, wherein the compressive layer has a surface compressive stress CS in a range from about 100 MPa to about 400 MPa at a surface of the glass article and a compressive stress profile having a linear portion a extending from the surface to the depth of compression DOC and a slope m_a, wherein −

2 MPa/μ

m≧

m_a≧

−

8 MPa/m.

44. The strengthened glass article of claim 40, wherein the thickness t is in a range from about 0.15 mm up to about 2.0 mm.

45. The strengthened glass of claim 40, wherein the strengthened glass comprises an alkali aluminosilicate glass.

46. The strengthened glass article of claim 45, wherein the alkali aluminosilicate glass further comprises up to about 10 mol % Li₂O.

47. The strengthened glass of claim 45, wherein the alkali aluminosilicate glass comprises at least about 4 mol % P₂O₅ and from 0 mol % to about 4 mol % B₂O₃, wherein 1.3<

[(P₂O₅+R₂O)/M₂O₃]≦

2.3, where M₂O₃═

Al₂O₃+B₂O₃, and R₂O is the sum of monovalent cation oxides present in the alkali aluminosilicate glass.

48. The glass article of claim 45, wherein the glass consists essentially of 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;

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

from about 13 to about 30 mol % R_xO, wherein R_xO is the sum of the alkali metal oxides, alkaline earth metal oxides, and transition metal monoxides present in the glass;

from about 11 to about 30 mol % M₂O₃, where M₂O₃═

Al₂O₃+B₂O₃;

from 0 mol % to about 1 mol % K₂O;

from 0 mol % to about 4 mol % B₂O₃, and 3 mol % or less of one or more of TiO₂, MnO, Nb₂O₅, MoO₃, Ta₂O₅, WO₃, ZrO₂, Y₂O₃, La₂O₃, HfO₂, CdO, SnO₂, Fe₂O₃, CeO₂, As₂O₃, Sb₂O₃, Cl, and Br; and

1.3<

[(P₂O₅+R₂O)/M₂O₃]≦

2.3, where R₂O is the sum of monovalent cation oxides present in the glass.

49. The glass article of claim 40, wherein the glass article has at least a 60% survival rate when dropped in an inverted ball drop test from a height of about 80 cm onto a drop surface.