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 method for producing a tempered glass comprising the steps of:
preparing a glass batch so that a glass for tempering comprises, as a glass composition, in terms of mass %, 45 to 57.5% of SiO 2 , 22 to 30% of Al 2 O 3 , 0 to 3% of CaO, 8 to 30% of Li 2 O+Na 2 O+K 2 O, 0 to 0.1% of Li 2 O, 8 to 20% of Na 2 O, less than 0.1% of As 2 O 3 , and less than 0.1% of Sb 2 O 3 , wherein the glass batch comprises a hydroxide raw material;
melting the glass batch to obtain a molten glass,
forming the molten glass into a glass for tempering having a β-OH value of 0.3 to 1/mm; and
subjecting the glass for tempering to an ion-exchange treatment to form a compression stress layer on a surface of the glass for tempering.
2. The method for producing a tempered glass according to claim 1 , wherein the glass for tempering comprises 22 to 30% of Al 2 O 3 , and the hydroxide raw material is an aluminum hydroxide.
3. The method for producing a tempered glass according to claim 1 , wherein the glass for tempering further comprises 0.001 to 10% of ZrO 2 , and the glass batch further comprises a hydrous zirconium oxide.
4. The method for producing a 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 method for producing a tempered glass according to claim 1 , wherein the glass for tempering has a softening point of 900° C. or less.
6. The method for producing a tempered glass according to claim 1 , wherein the glass for tempering has a strain point of 400° C. or more.
7. The method for producing a tempered glass according to claim 1 , wherein the glass for tempering is formed into a flat plate shape by an overflow down-draw method.
8. The method for producing a tempered glass according to claim 1 , wherein the glass for tempering has a liquidus viscosity of 10 4 dPa·s or more.
9. The method for producing a tempered glass according to claim 1 , wherein the glass for tempering has a thermal expansion coefficient of 50 to 110×10 −7 /° C.
10. The method for producing a tempered glass according to claim 1 , wherein the method further comprises the step of subjecting the glass for tempering to a thermal processing before the ion-exchange treatment.
11. The method for producing a tempered glass according to claim 1 , wherein the method further comprises the step of subjecting the glass for tempering to a thermal processing before the ion-exchange treatment, so that the glass for tempering has a shape other than a flat plate shape.
12. A method for producing a glass for tempering comprising the steps of:
preparing a glass batch so that the glass for tempering comprises, as a glass composition, in terms of mass %, 45 to 57.5% of SiO 2 , 22 to 30% of Al 2 O 3 , 0 to 3% of CaO, 8 to 30% of Li 2 O+Na 2 O+K 2 O, 0 to 0.1% of Li 2 O, 8 to 20% of Na 2 O, less than 0.1% of As 2 O 3 , and less than 0.1% of Sb 2 O 3 , wherein the glass batch comprises a hydroxide raw material;
melting the glass batch to obtain a molten glass,
forming the molten glass into the glass for tempering having a β-OH value of 0.3 to 1/mm.
13. The method for producing a glass for tempering according to claim 12 , wherein the glass for tempering comprises 22 to 30% of Al 2 O 3 , and the hydroxide raw material is an aluminum hydroxide.
14. The method for producing a glass for tempering according to claim 12 , wherein the glass for tempering further comprises 0.001 to 10% of ZrO 2 , and the glass batch further comprises a hydrous zirconium oxide.
15. The method for producing a glass for tempering according to claim 12 , wherein the glass for tempering has a softening point of 900° C. or less.
16. The method for producing a glass for tempering according to claim 12 , wherein the glass for tempering has a strain point of 400° C. or more.
17. The method for producing a glass for tempering according to claim 12 , wherein the glass for tempering is formed into a flat plate shape by an overflow down-draw method.
18. The method for producing a glass for tempering according to claim 12 , wherein the glass for tempering has a liquidus viscosity of 10 4 dPa·s or more.
19. The method for producing a glass for tempering according to claim 12 , wherein the glass for tempering has a thermal expansion coefficient of 50 to 110×10 −7 /° C.
20. The method for producing a glass for tempering according to claim 12 , wherein the method further comprises the step of subjecting the glass for tempering to a thermal processing.
21. The method for producing a glass for tempering according to claim 12 , wherein the method further comprises the step of subjecting the glass for tempering to a thermal processing so that the glass for tempering has a shape other than a flat plate shape.