Glass for chemical tempering and chemically tempered glass
View Patent ↗To provide chemically tempered glass which is less likely to break even if scratched. Chemically tempered glass, which comprises, as represented by mole percentage based on the following oxides, from 56 to 72% of SiO 2 , from 8 to 20% of Al 2 O 3 , from 9 to 25% of Na 2 O, from 0 to 2% of K 2 O, and from 0 to 15% of MgO, and which has a surface compressive stress of at least 900 MPa and an internal tensile stress of at most 30 MPa. Glass for chemical tempering, which comprises, as represented by mole percentage based on the following oxides, from 56 to 69% of SiO 2 , from 8 to 16% of Al 2 O 3 , from 9 to 22% of Na 2 O, from 0 to 1% of K 2 O, from 5.5 to 14% of MgO, from 0 to 2% of ZrO 2 , and from 0 to 6% of B 2 O 3 .
1. A glass comprising, as represented by mole percentage based on the following oxides: from 56 to 69% of SiO 2 ; from 8 to 16% of Al 2 O 3 ; from 9 to 22% of Na 2 O; from 0 to 2% of K 2 O; from 7 to 15% of MgO; from 0 to less than 1% of CaO; and from 0 to 1% of ZrO 2 , wherein the glass contains no B 2 O 3 , the glass has a glass transition temperature of at least 627° C., the glass has a temperature at which a viscosity of the glass is 10 4 dPa·s of 1333° C. or less, and Z calculated by the following formula by using the contents, as represented by mole percentage, of SiO 2 , Al 2 O 3 , Na 2 O, MgO, and K 2 O is at least 870:
Z=2×SiO 2 +55×Al 2 O 3 +22×Na 2 O+15×MgO−126×K 2 O.
2. The glass according to claim 1 , wherein X calculated by the following formula by using the contents, as represented by mole percentage, of SiO 2 , Al 2 O 3 , Na 2 O and MgO is at most 1:
X=−0.4×SiO 2 −0.5×Al 2 O 3 −0.4×Na 2 O−0.4×MgO+41.5.
3. The glass according to claim 1 , wherein Z3 calculated by the following formula by using the contents, as represented by mole percentage, of SiO 2 , Al 2 O 3 , Na 2 O, MgO and ZrO 2 is at most 0.150:
Z3=−0.00722×SiO 2 +0.0264×Al 2 O 3 +0.0149×Na 2 O+0.0035×MgO−0.0204×ZrO 2 .
4. The glass according to claim 1 , wherein the content of SiO 2 is from 62 to 66%, the content of Al 2 O 3 is from 10.5 to 13%, the content of Na 2 O is from 14 to 17%, and the content of MgO is at most 9%.
5. The glass according to claim 4 , wherein the content of SiO 2 is from 63 to 66%, and the content of ZrO 2 is from 0.2 to 1%.
6. The glass according to claim 1 , wherein the difference obtained by subtracting the content of Al 2 O 3 from the content of Na 2 O is less than 5%.
7. The glass according to claim 1 , wherein the total content of SiO 2 , Al 2 O 3 , Na 2 O and MgO is at least 98%.
8. The glass according to claim 1 , wherein the content of ZrO 2 is from 0 to 0.5%.
9. The glass according to claim 1 , wherein the liquid phase temperature of the glass is at most a temperature at which the viscosity of the glass becomes 10 4 dPa·s.
10. The glass according to claim 1 , wherein Z is at least 1,000.
11. The glass according to claim 1 , wherein no CaO is contained.
12. The glass according to claim 1 , wherein the content of MgO is 9%.
13. A chemically tempered glass, which is obtained by chemically tempering the glass as defined in claim 1 .
14. The chemically tempered glass according to claim 13 , wherein the chemically tempered glass has a surface compressive stress of at least 1,000 MPa.
15. The chemically tempered glass according to claim 14 , wherein the chemically tempered glass has a compressive stress layer thickness of at least 20 μm.
16. A cover glass made of the chemically tempered glass as defined in claim 13 .
17. A display device comprising the cover glass as in claim 16 .
18. A touch panel comprising:
a glass substrate made of the chemically tempered glass as defined in claim 13 ; and
an electrode for detecting an input position formed on the glass substrate.
19. A glass comprising, as represented by mole percentage based on the following oxides: from 56 to 69% of SiO 2 ; from 8 to 16% of Al 2 O 3 ; from 9 to 22% of Na 2 O; from 0 to 2% of K 2 O; from 7 to 15% of MgO; from 0 to less than 1% of CaO; and from 0 to 1% of ZrO 2 , wherein the glass contains no B 2 O 3 , the glass has a glass transition temperature of at least 627° C., the glass has a temperature at which a viscosity of the glass is 10 4 dPa·s of 1333° C. or less, and Z4 calculated by the following formula by using the contents, as represented by mole percentage, of Al 2 O 3 , K 2 O and MgO is at least 24:
Z4=3×Al 2 O 3 −10×K 2 O+MgO.
20. The glass according to claim 19 , wherein Z4 is at least 35.
21. The glass according to claim 19 , wherein X calculated by the following formula by using the contents, as represented by mole percentage, of SiO 2 , Al 2 O 3 , Na 2 O and MgO is at most 1:
X=−0.4×SiO 2 −0.5×Al 2 O 3 −0.4×Na 2 O−0.4×MgO+41.5.
22. The glass according to claim 19 , wherein Z3 calculated by the following formula by using the contents, as represented by mole percentage, of SiO 2 , Al 2 O 3 , Na 2 O, MgO and ZrO 2 is at most 0.150:
Z3=−0.00722×SiO 2 +0.0264×Al 2 O 3 +0.0149×Na 2 O+0.0035×MgO−0.0204×ZrO 2 .
23. The glass according to claim 19 , wherein no CaO is contained.
24. The glass according to claim 19 , wherein the content of MgO is 9%.
25. A glass comprising, as represented by mole percentage based on the following oxides: from 56 to 69% of SiO 2 ; from 8 to 16% of Al 2 O 3 ; from 9 to 22% of Na 2 O; from 0 to 2% of K 2 O; from 7 to 15% of MgO; from 0 to less than 1% of CaO; and from 0 to 1% of ZrO 2 , wherein the glass contains no B 2 O 3 , the glass has a glass transition temperature of at least 627° C., the glass has a temperature at which a viscosity of the glass is 10 4 dPa·s of 1333° C. or less, and Z2 calculated by the following formula by using the contents, as represented by mole percentage, of SiO 2 , Al 2 O 3 , Na 2 O, MgO and ZrO 2 is at least 860:
Z2=3.5×SiO 2 +85×Al 2 O 3 +0.80×Na 2 O+2.0×MgO+81×ZrO 2 .
26. The glass according to claim 25 , wherein Z2 is at least 1,300.
27. The glass according to claim 25 , wherein X calculated by the following formula by using the contents, as represented by mole percentage, of SiO 2 , Al 2 O 3 , Na 2 O and MgO is at most 1:
X=−0.4×SiO 2 −0.5×Al 2 O 3 −0.4×Na 2 O−0.4×MgO+41.5.
28. The glass according to claim 25 , wherein Z3 calculated by the following formula by using contents, as represented by mole percentage, of SiO 2 , Al 2 O 3 , Na 2 O, MgO and ZrO 2 is at most 0.150:
Z3=−0.00722×SiO 2 +0.0264×Al 2 O 3 +0.0149×Na 2 O+0.0035×MgO−0.0204×ZrO 2 .
29. The glass according to claim 25 , wherein no CaO is contained.
30. The glass according to claim 25 , wherein the content of MgO is 9%.