GLASS SUBSTRATE, CHEMICALLY STRENGTHENED GLASS SUBSTRATE AND COVER GLASS, AND METHOD FOR MANUFACTRUING THE SAME

• US 20120052275A1
• Filed: 08/26/2011
• Published: 03/01/2012
• Est. Priority Date: 08/30/2010
• Status: Abandoned Application

• Current Assignee: Hoya Corporation, Avanstrate, Inc. (Volcan Investments Ltd.)
• Original Assignee: Hoya Corporation, Avanstrate, Inc. (Volcan Investments Ltd.)
• Inventors: KOYAMA, Akihiro, HASHIMOTO, Kazuaki, TAKANO, Tetsuo, MORISHITA, Mikiko
• Application Number:
  US13/219,255
• Publication Number:
  US 20120052275A1
• Time in Patent Office: Days
• US Class Current: 428/215
• CPC Class Codes: B32B 2457/20 Displays, e.g. liquid crystal displays, plasma displays
• CPC Class Codes: C03C 15/00 Surface treatment of glass, not in the form of fibres or filaments, by etching etching or surface-brightening compositions, in general C09K13/00
• CPC Class Codes: C03C 21/002 to perform ion-exchange between alkali ions C03C21/005 takes precedence
• CPC Class Codes: C03C 3/087 containing calcium oxide, e.g. common sheet or container glass
• CPC Class Codes: Y10T 428/24967 Absolute thicknesses specified

Abstract

Provided is a cover glass having a down-drawable composition including, in mass percent: 50%-70% SiO₂, 5%-20% Al₂O₃, 6%-20% Na₂O, 0%-10% K₂O, 0%-10% MgO, above 2%-20% CaO, and 0%-4.8% ZrO₂ wherein, (i) 46.5%≦(SiO₂−½Al₂O₃)≦59%, (ii) 0.3<CaO/RO, where RO represents a total mass percent of one or more compounds selected from the group consisting of MgO, CaO, SrO and BaO included in the glass substrate, (iii) SrO+BaO<10%, (iv) 0≦(ZrO₂+TiO₂)/SiO₂)<0.07, and (v) 0≦B₂O₃/R¹₂O<0.1, where R¹₂O represents a total mass percent of one or more compounds selected from the group consisting of Li₂O, Na₂O and K₂O included in the glass substrate.

Claims

1. A glass substrate having a down-drawable composition comprising, in mass percent:

2. The glass substrate as recited in claim 1, wherein

Li₂O/(RO+Li₂O)<

0.3, where Li₂O represents the mass percent of Li₂O in the glass substrate.

3. The glass substrate as recited in claim 1, wherein

4%<

RO.

4. The glass substrate as recited in claim 1, wherein

(ZrO₂+TiO₂+½

B₂O₃+½

Na₂O)/SiO₂<

0.3, where Na₂O represent the mass percent of Na₂O in the glass substrate.

5. The glass substrate as recited in claim 1, wherein

TiO₂<

3%.

6. The glass substrate as recited in claim 1, wherein

a liquidus temperature of the glass substrate is less than 1090°

C.

7. A chemically strengthened glass substrate comprising:

the glass substrate according to claim 1 including a compressive stress layer at a surface of thereof, which is formed by a chemically strengthening treatment applied to the glass substrate.

8. The chemically strengthened glass substrate as recited in claim 7, wherein

a plate thickness of the glass substrate is 0.3 mm to 1.5 mm, a compressive layer depth is 25 μ

m to 70 μ

m and a compressive stress value is 400 MPa to 900 MPa.

9. A cover glass comprising:

the chemically strengthened glass substrate according to claim 7.

10. The cover glass as recited in claim 9, wherein

a plate thickness of the glass substrate is 0.3 mm to 1.5 mm, a compressive layer depth is 25 μ

m to 70 μ

m and a compressive stress value is 400 MPa to 900 MPa.

11. A method for manufacturing a glass substrate comprising:

melting a glass raw material blended so as to have a glass composition comprising, in mass percent,

12. The method as recited in claim 11, wherein

in the frit material, Li₂O/(RO+Li₂O)<

0.3, where Li₂O represents the mass percent of Li₂O in the frit material.

13. The method as recited in claim 11, wherein

in the frit material, 4%<

RO.

14. The method as recited in claim 11, wherein

in the frit material, (ZrO₂+TiO₂+½

B₂O₃+½

Na₂O)/SiO₂<

0.3, where Na₂O represent the mass percent of Na₂O in the frit material.

15. The method as recited in claim 11, wherein

in the frit material, TiO₂<

3%.

16. A method for manufacturing a chemically strengthened glass substrate comprising:

preparing the glass substrate by using the method according to claim 11; and

applying an ion-exchange treatment to the glass substrate.

17. A method for manufacturing a cover glass comprising:

preparing the glass substrate by using the method according to claim 11; and

performing etching on the glass substrate.

18. The method as recited in claim 17, further comprising

applying an ion-exchange treatment to the glass substrate after the performing of the etching.

19. A glass substrate manufactured by the method according to claim 11.

20. A chemically strengthened glass substrate manufactured by the method according to claim 16.

21. A cover glass manufactured by the method according to claim 17.