Glass for chemical strengthening, chemically strengthened glass, and method for manufacturing chemically strengthened glass

Patent metadata

Field	Value
Publication number	US-9926220-B2
Application number	US-201615266157-A
Country	US
Kind code	B2
Filing date	Sep 15, 2016
Priority date	Mar 28, 2014
Publication date	Mar 27, 2018
Grant date	Mar 27, 2018

Abstract

An object of the present invention is to provide a glass for chemical strengthening which is capable of improving strength as compared with an ordinary soda lime silicate glass even when the same chemical strengthening treatment as that in a conventional process is applied and has good devitrification characteristics, a chemically strengthened glass using the glass for chemical strengthening, and a method for producing the chemically strengthened glass. The present invention provides a glass for chemical strengthening having a specific glass composition described in the present specification.

First claim

The invention claimed is:

1. A glass, comprising, as expressed by mass percentage based on oxides, 64 to 72% of SiO 2 , 4.4 to 7% of Al 2 O 3 , 7 to 10.9% of MgO, 0.1 to 5% of CaO, 14 to 19% of Na 2 O, and 0 to 3% of K 2 O, wherein RO is 8 to 11% wherein the RO represents the sum of alkaline earth metal oxides, and RO/(RO+R 2 O) is 0.20 or more and 0.42 or less, wherein the R 2 O represents the sum of alkali metal oxides,
and wherein the glass has a temperature (T 2 ) at which a viscosity is 10 2 dPa·s of 1550° C. or lower.

2. The glass according to claim 1 , wherein the RO/(RO+R 2 O) is 0.40 or less.

3. The glass according to claim 1 , comprising 5% or more of Al 2 O 3 .

4. The glass according to claim 1 , comprising 8% or more of MgO.

5. The glass according to claim 1 , comprising 10% or less of MgO.

6. The glass according to claim 1 , further comprising 0 to 4% of B 2 O 3 , 0 to 1% of Fe 2 O 3 and 0 to 1% of TiO 2 .

7. The glass according to claim 1 , which has been formed according to a float process.

8. A chemically strengthened glass obtained by chemically strengthening the glass according to claim 1 .

9. The chemically strengthened glass according to claim 8 , having a surface compressive stress of 300 MPa or more.

10. The chemically strengthened glass according to claim 8 , having a depth of compressive stress of 10 μm or more.

11. A method for producing a chemically strengthened glass, comprising a chemical strengthening step of subjecting the glass according to claim 1 to an ion-exchange treatment.

12. The glass according to claim 1 , comprising 64.1 to 72% of SiO 2 and 4.4 to 6.9% of Al 2 O 3 .

13. The glass according to claim 1 , comprising 64.3 to 72% of SiO 2 and 4.4 to 6.7% of Al 2 O 3 .

14. The glass according to claim 1 , comprising 65.6 to 72% of SiO 2 and 4.4 to 5.9% of Al 2 O 3 .

Assignees

• Asahi Glass Co Ltd

Inventors

• Miyasaka Junko
• Ohara Seiki
• Yamazaki Shuji
• Akiba shusaku
• Kase Junichiro

Classifications

• C03C2204/00

  Glasses, glazes or enamels with special properties · CPC title

• C03C3/087 Primary

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

• C03C4/18

  for ion-sensitive glass · CPC title

• C03C21/002

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