Glass plate for display devices
View Patent ↗To provide a glass plate for display devices wherein without carrying out a post treatment, the depth of a compression stress layer is increased, while the surface compression stress is prevented from being excess only by chemical tempering. A glass plate for display devices, which is obtained by chemically tempering a glass plate comprising, as represented by mol % based on the following oxides, from 50 to 74% of SiO 2 , from 1 to 10% of Al 2 O 3 , from 6 to 14% of Na 2 O, from 3 to 15% of K 2 O, from 2 to 15% of MgO, from 0 to 10% of CaO and from 0 to 5% of ZrO 2 , wherein the total content of SiO 2 and Al 2 O 3 is at most 75%, the total content of Na 2 O and K 2 O, i.e. Na 2 O+K 2 O, is from 12 to 25%, and the total content of MgO and CaO, i.e. MgO+CaO, is from 7 to 15%.
1. A glass plate for display devices, which is obtained by chemically tempering a glass plate comprising, as represented by mol % based on the following oxides,
from 50 to 74% of SiO 2 ,
from 1 to 10% of Al 2 O 3 ,
from 6 to 14% of Na 2 O,
from 4.0 to 15% of K 2 O,
at most 15% of MgO,
from 0 to 0.5% of CaO and
from 0 to 5% of ZrO 2 ,
wherein
the total content of SiO 2 and Al 2 O 3 is at most 75%,
the total content of Na 2 O and K 2 O is from 12 to 25%,
the total content of MgO and CaO is at most 15%,
the content of MgO is at least 6.5 mass %,
said glass plate is chemically tempered, and
said glass plate has a thickness of 0.2 to 1.0 mm.
2. The glass plate for display devices according to claim 1 , wherein said glass plate further comprises BaO in a non-zero amount and the amount of BaO is less than 1%.
3. The glass plate for display devices according to claim 1 , wherein the glass plate further comprises at least one of SrO or BaO in a non-zero amount, and the total content of alkaline earth metal oxides is at most 15%.
4. The glass plate for display devices according to claim 1 , wherein the glass plate contains no Li 2 O.
5. The glass plate for display devices according to claim 1 , wherein the glass plate contains at most 2% of Li 2 O.
6. The glass plate for display devices according to claim 1 , wherein the glass plate is made by a float process followed by chemical tempering.
7. The glass plate for display devices according to claim 1 , wherein the glass plate contains a compressive stress layer and the thickness t of the compressive stress layer is from 20 to 50 μm.
8. The glass plate for display devices according to claim 1 , wherein the glass plate contains a compressive stress layer and the thickness t of the compressive stress layer is from 50 to 88 μm.
9. The glass plate for display devices according to claim 1 , wherein the glass plate has a surface compressive stress S of from 300 to 629 mPa.
10. The glass plate for display devices according to claim 1 , wherein said glass plate further comprises B 2 O 3 in a non-zero amount and the amount of B 2 O 3 is less than 1%.
11. A glass plate for display devices, wherein the glass plate comprises, as represented by mol % based on the following oxides,
from 60 to 70% of SiO 2 ,
from 2 to 8% of Al 2 O 3 ,
from 6 to 14% of Na 2 O,
from 3.5 to 8% of K 2 O,
at most 15% of MgO,
from 0 to 0.5% of CaO and
from 0 to 5% of ZrO 2 ,
wherein
the total content of SiO 2 and Al 2 O 3 is at most 75%,
the total content of Na 2 O and K 2 O is at most 18%,
the total content of MgO and CaO is at most 15%,
the sum of the content of K 2 O multiplied by 1.7 and the content of Na 2 O is less than 19%,
the content of MgO is at least 6.5 mass %,
said glass plate is chemically tempered, and
said glass plate has a thickness of 0.2 to 1.0 mm.
12. The glass plate for display devices according to claim 11 , wherein said glass plate further comprises BaO in a non-zero amount and the amount of BaO is less than 1%.
13. The glass plate for display devices according to claim 11 , wherein the glass plate further comprises at least one of SrO or BaO in a non-zero amount, and the total content of alkaline earth metal oxides is at most 15%.
14. The glass plate for display devices according to claim 11 , wherein the glass plate contains no Li 2 O.
15. The glass plate for display devices according to claim 11 , wherein the glass plate contains at most 2% of Li 2 O.
16. The glass plate for display devices according to claim 11 , wherein the glass plate contains a compressive stress layer and the thickness t of the compressive stress layer is from 20 to 50 μm.
17. The glass plate for display devices according to claim 11 , wherein the glass plate contains a compressive stress layer and the thickness t of the compressive stress layer is from 50 to 88 μm.
18. The glass plate for display devices according to claim 11 , wherein the glass plate has a surface compressive stress S of from 300 to 629 mPa.
19. The glass plate for display devices according to claim 11 , wherein said glass plate further comprises B 2 O 3 in a non-zero amount and the amount of B 2 O 3 is less than 1%.
20. A glass plate for display devices, wherein in the glass plate comprises, as represented by mol % based on the following oxides,
SiO 2 is from 63% to 74%,
Al 2 O 3 is from 3% to 10%,
Na 2 O is from 8% to 12%,
K 2 O is from 4 to 8%,
MgO is at most 14%,
CaO is from 0 to 1%,
ZrO 2 is from 1 to 4%, and
wherein
the total content of SiO 2 and Al 2 O 3 is at most 75%,
Na 2 O+K 2 O is from 14 to 17%,
the difference obtained by deducting the content of Al 2 O 3 from Na 2 O+K 2 O is at least 10%,
the total content of MgO and CaO is at most 15%,
the content of MgO is at least 6.5 mass %,
said glass plate is chemically tempered, and
said glass plate has a thickness of 0.2 to 1.0 mm.
21. The glass plate for display devices according to claim 20 , wherein the sum of the content of K 2 O multiplied by 1.7 and the content of Na 2 O is less than 19%.
22. A glass plate for display devices, wherein said glass plate comprises, as represented by mol % based on the following oxides,
from 50 to 74% of SiO 2 ,
from 1 to 10% of Al 2 O 3 ,
from 6 to 12% of Na 2 O,
from 4 to 15% of K 2 O,
MgO is at most 14%,
from 0 to 10% of CaO and
from 0 to 5% of ZrO 2 ,
B 2 O 3 in a non-zero amount and the amount of B 2 O 3 is less than 1%
wherein
the total content of SiO 2 and Al 2 O 3 is at most 75%,
the total content of Na 2 O and K 2 O is from 14 to 25%,
the difference obtained by deducting the content of Al 2 O 3 from Na 2 O+K 2 O is at least 10%,
the total content of MgO and CaO is at most 15%,
the content of MgO is at least 6.5 mass %,
said glass plate is chemically tempered, and
said glass plate has a thickness of 0.2 to 1.0 mm.