Glass and chemically toughened glass using same
An object is to provide a glass for chemical toughening treatment satisfying low brittleness, low melt viscosity and high chemical toughening characteristics, and a chemically toughened glass using the same. Provided is a glass for chemical toughening treatment containing, in mass % in terms of oxides, SiO 2 63 to 76, B 2 O 3 0 to 2, Al 2 O 3 2 to 10, MgO 2 to 12, CaO 0.1 to 8, Na 2 O 14.5 to 19, K 2 O 0 to 3, and Fe 2 O 3 0 to 0.5, satisfying a total content of alkali earth metal oxides (RO) being from 5 to 15, satisfying 15×MgO/RO−RO≥3, and having a temperature T 2 at which a glass viscosity reaches 10 2 dPa·s being 1,600° C. or lower.
1. A glass for chemical toughening treatment comprising, in mass % in terms of oxides,
SiO 2 66 to 76,
B 2 O 3 0 to 2,
Al 2 O 3 2 to 7,
MgO 2 to 12,
CaO 0.1 to 8,
Na 2 O 14.5 to 19,
K 2 O 0 to 2, and
Fe 2 O 3 0 to 0.5,
satisfying a total content of alkaline earth metal oxides (RO) being from 5 to 15,
satisfying 15×MgO/RO−RO≥3, and
having a temperature T 2 at which a glass viscosity reaches 10 2 dPa·s being 1,570° C. or lower.
2. The glass for chemical toughening treatment according to claim 1 , satisfying MgO/RO being 0.5 or more.
3. The glass for chemical toughening treatment according to claim 1 , satisfying, in mass % in terms of an oxide,
SiO 2 66 to 73,
MgO 6 to 10, and
CaO 0.3 to 5.
4. A chemically toughened glass in which a chemical toughening treatment is carried out on at least one principal surface of the glass for chemical toughening treatment described in claim 1 .
5. The chemically toughened glass according to claim 4 , wherein the principal surface subjected to the chemical toughening treatment has a depth of surface compressional stress layer (DOL) of 8 μm or more and a surface compressional stress (CS) of 300 MPa or more.
6. The chemically toughened glass according to claim 4 , wherein the principal surface subjected to the chemical toughening treatment has a depth of surface compressional stress layer (DOL) of 20 μm or more and a surface compressional stress (CS) of 550 MPa or more.
7. The glass for chemical toughening treatment according to claim 1 , satisfying, in mass % in terms of an oxide,
Al 2 O 3 2 to less than 7.
8. The glass for chemical toughening treatment according to claim 7 , satisfying, in mass % in terms of an oxide,
Al 2 O 3 2 to 5.9.
9. A glass for chemical toughening treatment comprising, in mass % in terms of oxides,
SiO 2 63 to 76,
B 2 O 3 0 to 2,
Al 2 O 2 to less than 7,
MgO 2 to 12,
CaO 0.1 to 8,
Na 2 O 14.5 to 19,
K 2 O 0 to 2, and
Fe 2 O 3 0 to 0.5,
satisfying a total content of alkaline earth metal oxides (RO) being from 5 to 15,
satisfying 15×MgO/RO−RO≥3, and
having a temperature T 2 at which a glass viscosity reaches 10 2 dPa·s being 1,570° C. or lower.
10. The glass for chemical toughening treatment according to claim 9 , satisfying MgO/RO being 0.5 or more.
11. The glass for chemical toughening treatment according to claim 9 , satisfying, in mass % in terms of an oxide,
SiO 2 63 to 73,
MgO 6 to 10, and
CaO 0.3 to 5.
12. A chemically toughened glass in which a chemical toughening treatment is carried out on at least one principal surface of the glass for chemical toughening treatment described in claim 9 .
13. The chemically toughened glass according to claim 12 , wherein the principal surface subjected to the chemical toughening treatment has a depth of surface compressional stress layer (DOL) of 8 μm or more and a surface compressional stress (CS) of 300 MPa or more.
14. The chemically toughened glass according to claim 12 , wherein the principal surface subjected to the chemical toughening treatment has a depth of surface compressional stress layer (DOL) of 20 μm or more and a surface compressional stress (CS) of 550 MPa or more.
15. The glass for chemical toughening treatment according to claim 9 , satisfying, in mass % in terms of an oxide,
SiO 2 66 to 76.
16. The glass for chemical toughening treatment according to claim 15 , satisfying, in mass % in terms of an oxide,
Al 2 O 3 2 to 5.9.