Ion exchangeable glass with fast diffusion
Glasses that undergo rapid ion exchange. The glasses comprise SiO 2 , Al 2 O 3 , P 2 O 5 , Na 2 O, K 2 O, and, in some embodiments, at least one of MgO and ZnO. The glass may, for example, be ion exchanged in a molten KNO 3 salt bath in less than 1 hour at temperatures in a range from about 370° C. to about 390° C. to achieve a depth of surface compressive layer of greater than about 45 microns, or in a range from about 0.05t to about 0.22t, where t is the thickness of the glass. The glasses are fusion formable and, in some embodiments, compatible with zircon.
1. A glass comprising:
56 mol % to 67 mol % SiO 2 ;
Al 2 O 3 ;
4 mol % to 8 mol % P 2 O 5 ;
Na 2 O;
greater than 1 mol % K 2 O; and
ZnO,
wherein (R 2 O(mol %)+R′O(mol %))−(Al 2 O 3 (mol %)+P 2 O 5 (mol %))<0, R 2 O=Li 2 O+Na 2 O+K 2 O+Rb 2 O+Cs 2 O, and R′O=ZnO+MgO+CaO+SrO+BaO.
2. The glass of claim 1 , wherein the glass comprises:
57 mol % to 67 mol % SiO 2 ;
9 mol % to 18 mol % Al 2 O 3 ;
13 mol % to 16 mol % Na 2 O; and
greater than 1 mol % to 5 mol % K 2 O.
3. The glass of claim 1 , further comprising less than mol % MgO.
4. The glass of claim 1 , wherein the glass comprises greater than 60 mol % SiO 2 .
5. The glass of claim 1 , wherein R 2 O+R′O is less than 18 mol %.
6. The glass of claim 1 , wherein the glass is substantially free of MgO.
7. The glass of claim 1 , wherein the glass is substantially free of at least one of B 2 O 3 and lithium.
8. The glass of claim 1 , wherein the glass has a coefficient of thermal expansion of at least 92×10 −7 ° C. −1 .
9. The glass of claim 1 , wherein the glass has a liquidus temperature T L , a 160 kP temperature T 160kP , a 35 kP temperature T 35kP , and a zircon breakdown temperature T breakdown , wherein T L <T 160P and T breakdown >T 35kP .
10. The glass of claim 1 , wherein the glass has a compressive layer extending from a surface of the glass to a depth of compression of at least 45 μm.
11. The glass of claim 10 , wherein the depth of compression is in a range from 15 μm up to 200 μm.
12. The glass of claim 10 , wherein the glass has a thickness t and wherein the depth of compression is less than or equal to 0.22t.
13. The glass of claim 10 , wherein the compressive layer comprises a compressive stress of at least 500 MPa.
14. The glass of claim 10 , wherein the glass has been ion exchanged in an ion exchange bath comprising KNO 3 at a temperature in a range from 370° C. to 390° C. for up to one hour.
15. An ion exchanged glass comprising the glass of claim 1 .
16. A consumer electronic product, comprising:
a housing having a front surface, a back surface and side surfaces;
electrical components provided at least partially within the housing, the electrical components including at least a controller, a memory, and a display, the display being provided at or adjacent the front surface of the housing; and
the glass of claim 1 disposed over the display.
17. A glass comprising:
greater than 60 mol % SiO 2 ;
Na 2 O;
4 mol % to 8 mol % P 2 O 5 ;
9 mol % to 18 mol % Al 2 O 3 ;
greater than 1 mol % K 2 O; and
0 mol % B 2 O 3 ,
wherein (R 2 O(mol %)+R′O(mol %)) (Al 2 O 3 (mol %)+P 2 O 5 (mol %))<0, R 2 O=Li 2 O+Na 2 O+K 2 O+Rb 2 O+Cs 2 O, and R′O=ZnO+MgO+CaO+SrO+BaO.
18. The glass of claim 17 , wherein the glass comprises greater than 60 mol % to 65 mol % SiO 2 .
19. The glass of claim 17 , wherein the glass comprises 13 mol % to 16 mol % Na 2 O.
20. The glass of claim 17 , wherein the glass comprises:
greater than 60 mol % to 65 mol % SiO 2 ;
9 mol % to 18 mol % Al 2 O 3 ;
13 mol % to 16 mol % Na 2 O; and
greater than 1 mol % to 5 mol % K 2 O.
21. The glass of claim 17 , further comprising less than 1 mol % MgO.
22. The glass of claim 17 , wherein R 2 O+R′O is less than 18 mol %.
23. The glass of claim 17 , wherein the glass is substantially free of MgO.
24. The glass of claim 17 , wherein the glass is substantially free of lithium.
25. The glass of claim 17 , wherein the glass has a coefficient of thermal expansion of at least 92×10 −7 ° C. −1 .
26. The glass of claim 17 , wherein the glass has a liquidus temperature T L , a 160 kP temperature T 160kP , a 35 kP temperature T 35kP , and a zircon breakdown temperature T breakdown , wherein T L <T 160P and T breakdown >T 35kP .
27. The glass of claim 17 , wherein the glass has a compressive layer extending from a surface of the glass to a depth of compression of at least 45 μm.
28. The glass of claim 27 , wherein the depth of compression is in a range from 45 μm up to 200 μm.
29. The glass of claim 27 , wherein the glass has a thickness t and wherein the depth of compression is less than or equal to 0.22t.
30. The glass of claim 27 , wherein the compressive layer comprises a compressive stress of at least 500 MPa.
31. The glass of claim 27 , wherein the glass has been ion exchanged in an ion exchange bath comprising KNO 3 at a temperature in a range from 370° C. to 390° C. for up to one hour.
32. An ion exchanged glass comprising the glass of claim 17 .
33. A consumer electronic product, comprising:
a housing having a front surface, a back surface and side surfaces;
electrical components provided at least partially within the housing, the electrical components including at least a controller, a memory, and a display, the display being provided at or adjacent the front surface of the housing; and
the glass of claim 17 disposed over the display.
34. A method of ion exchanging a glass comprising:
ion exchanging a glass in an ion exchange bath for a period of up to one hour to form an ion exchanged glass,
wherein:
the ion exchange bath comprises KNO 3 and is at a temperature in a range from 370° C. to 390° C.,
the glass comprises:
56 mol % to 67 mol % SiO 2 , Al 2 O 3 , 4 mol % to 8 mol % P 2 O 5 , Na 2 O, greater than 1 mol % K 2 O, and ZnO
wherein (R 2 O(mol %)+R′O(mol %))—(Al 2 O 3 (mol %)+P 2 O 5 (mol %))<0, R 2 O=Li 2 O+Na 2 O+K 2 O+Rb 2 O+Cs 2 O, and R′O=ZnO+MgO+CaO+SrO+BaO, and
the ion exchanged glass comprises a layer under a compressive stress, the layer extending from a surface of the ion exchanged glass to a depth of compression of at least 45 μm.
35. The method of claim 34 , wherein the glass comprises greater than 60 mol % to 65 mol % SiO 2 .
36. The method of claim 34 , wherein the glass further comprises up to 1 mol % MgO.
37. The method of claim 34 , wherein R 2 O+R′O is less than 18 mol %.
38. The method of claim 34 , wherein the ion exchanged glass comprises at least 13 mol % Al 2 O 3 .
39. The method of claim 34 , wherein the depth of compression is in a range from 45 μm up to about 200 μm.
40. The method of claim 34 , wherein the compressive stress is at least 500 MPa.
41. The method of claim 34 , wherein the glass has a thickness t and wherein the depth of compression is less than or equal to 0.22t.