Tempered glass and glass
A tempered glass of the present invention includes, as a glass composition, in terms of mass %, 45 to 75% of SiO 2 , 0 to 30% of Al 2 O 3 , and 0 to 30% of Li 2 O+Na 2 O+K 2 O and has a β-OH value of 0.3 to 1/mm.
1. A tempered glass having a compression stress layer on a surface thereof, the compression stress layer being formed by an ion exchange treatment, wherein the tempered glass comprises, as a glass composition, in terms of mass %, 45 to 75% of SiO 2 , 0 to 30% of Al 2 O 3 , and 0.1 to 30% of Li 2 O+Na 2 O+K 2 O and having a β-OH value of 0.3 to 1 /mm, and wherein the tempered glass has a shape other than a flat plate shape, which is formed by subjecting a glass comprising the glass composition and having a flat plate shape to a thermal processing.
2. The tempered glass according to claim 1 , wherein the glass having a flat plate shape is formed by an overflow down-drawn method.
3. The tempered glass according to claim 1 , further comprising, as the glass composition, 0 to 5 mass % of B 2 O 3 .
4. The tempered glass according to claim 1 ,
wherein the compression stress layer has a compression stress value of 50 MPa or more and a thickness of 10 μm or more.
5. The tempered glass according to claim 1 , which has a softening point of 900° C. or less.
6. The tempered glass according to claim 1 , which has a strain point of 400° C. or more.
7. The tempered glass according to claim 1 , which has a liquidus temperature of 1200° C. or less.
8. The tempered glass according to claim 1 , which has a liquidus viscosity of 10 4 dPa·s or more.
9. The tempered glass according to claim 1 , which has a thermal expansion coefficient of 50 to 110×10 −7 /° C.
10. The tempered glass according to claim 1 , wherein the tempered glass has a curved shape portion.
11. The tempered glass according to claim 1 , wherein the tempered glass has a stepped shape portion.
12. The tempered glass according to claim 1 , wherein the tempered glass has an unpolished surface.