Glass for chemical strengthening and chemically strengthened glass

Patent metadata

Field	Value
Publication number	US-2016355431-A1
Application number	US-201615179273-A
Country	US
Kind code	A1
Filing date	Jun 10, 2016
Priority date	Dec 13, 2013
Publication date	Dec 8, 2016
Grant date	—

Abstract

A chemically strengthened glass contains, as expressed by mass percentage based on oxides, 60% to 75% of SiO 2 , 3% to 9% of Al 2 O 3 , 2% to 10% of MgO, 3% to 10% of CaO, 10% to 18% of Na 2 O, at most 4% of K 2 O, 0% to 3% of ZrO 2 , 0% to 0.3% of TiO 2 , and 0.02% to 0.4% of SO 3 . It has a temperature T 2 at which a viscosity of a glass melt is 100 dPa·sec of 1530° C. or lower. In a chemically strengthened main surface thereof, it has a depth of a compressive stress layer of 8 μm or more and a surface compressive stress of 500 MPa or more.

First claim

1 . A chemically strengthened glass
comprising, as expressed by mass percentage based on oxides: 60% to 75% of SiO 2 , 3% to 9% of Al 2 O 3 , 2% to 10% of MgO, 3% to 10% of CaO, 10% to 18% of Na 2 O, at most 4% of K 2 O, 0% to 3% of ZrO 2 , 0% to 0.3% of TiO 2 , and 0.02% to 0.4% of SO 3 ; having a temperature T 2 at which a viscosity of a glass melt is 100 dPa·sec of 1530° C. or lower; and in a chemically strengthened main surface thereof, having a depth of a compressive stress layer of 8 μm or more and a surface compressive stress of 500 MPa or more.

2 . The chemically strengthened glass according to claim 1 , having a thickness falling within a range of 0.1 mm to 5 mm.

3 . The chemically strengthened glass according to claim 1 , chemically strengthened in all edge surfaces thereof.

4 . The chemically strengthened glass according to claim 1 , wherein the depth of the compressive stress layer is 25 μm or less.

5 . The chemically strengthened glass according to claim 1 , produced according to a float process.

6 . The chemically strengthened glass according to claim 1 , wherein an Sn component exists in at least one surface of glass surfaces.

7 . A glass
comprising, as expressed by mass percentage based on oxides: 60% to 75% of SiO 2 , 3% to 9% of Al 2 O 3 , 2% to 10% of MgO, 3% to 10% of CaO, 10% to 18% of Na 2 O, at most 4% of K 2 O, 0% to 3% of ZrO 2 , 0% to 0.3% of TiO 2 , and 0.02% to 0.4% of SO 3 ; and having a temperature T 2 at which a viscosity of a glass melt is 100 dPa·sec of 1530° C. or lower.

8 . The glass according to claim 7 , which is a glass applicable to a chemical strengthening treatment, having a depth of a compressive stress layer of 8 μm or more and a surface compressive stress of 500 MPa or more, in a chemically strengthened main surface thereof when being processed for the chemical strengthening treatment.

9 . The glass according to claim 7 , wherein when a refractive index at a room temperature of the glass is referred to as R 1 and when a refractive index at the room temperature of the glass, after kept at a temperature higher by about 100° C. than a glass transition point for 10 minutes and then annealed to the room temperature at a rate of 1° C./min, is referred to as R 2 , R 2 -R 1 is 0.0003 or more and 0.0012 or less.

10 . The glass according to claim 7 , produced according to a float process.

11 . A glass for chemical strengthening
comprising, as expressed by mass percentage based on oxides: 60% to 75% of SiO 2 , 3% to 9% of Al 2 O 3 , 2% to 10% of MgO, 3% to 10% of CaO, 10% to 18% of Na 2 O, at most 4% of K 2 O, 0% to 3% of ZrO 2 , 0% to 0.3% of TiO 2 , and 0.02% to 0.4% of SO 3 ; and having a temperature T 2 at which a viscosity of a glass melt is 100 dPa·sec of 1530° C. or lower.

12 . The glass for chemical strengthening according to claim 11 , wherein when a refractive index at a room temperature of the glass for chemical strengthening is referred to as R 1 and when a refractive index at the room temperature of the glass for chemical strengthening, after kept at a temperature higher by about 100° C. than a glass transition point for 10 minutes and then annealed to the room temperature at a rate of 1° C./min, is referred to as R 2 , R 2 -R 1 is 0.0003 or more and 0.0012 or less.

13 . The glass for chemical strengthening according to claim 11 , produced according to a float process.

Assignees

• Asahi Glass Co Ltd

Inventors

• Akiba shusaku
• Koike Akio
• Kase Junichiro
• Yamazaki Shuji

Classifications

• C03C21/002

  to perform ion-exchange between alkali ions (C03C21/005 takes precedence) · CPC title

• C03C3/087 Primary

  containing calcium oxide, e.g. common sheet or container glass · CPC title