Aluminosilicate glass for flat display devices

• US 6,087,284 A
• Filed: 05/26/1998
• Issued: 07/11/2000
• Est. Priority Date: 05/24/1997
• Status: Expired due to Term

• Current Assignee: Schott AG (Carl-Zeiss-Stiftung)
• Original Assignee: SCHOTT Glass
• Inventors: Brix, Peter, Linz, Wilfried
• Primary Examiner(s): MARCHESCHI, MICHAEL A
• Application Number:
  US09/084,252
• Time in Patent Office: 777 Days
• Field of Search: 501/63, 501/64, 501/69, 501/70, 501/72
• US Class Current: 501/69
• CPC Class Codes: C03C 3/085 containing an oxide of a divalent metal
• CPC Class Codes: C03C 3/087 containing calcium oxide, e.g. common sheet or container glass

Abstract

The invention relates to a solarization-stable aluminosilicate glass which has the following composition (in % by weight, based on oxide): SiO₂ 45-68; Al₂ O₃ >5-18; Na₂ O 0-5; K₂ O>9-15; where Na₂ O+K₂ O≧10; CaO 0-10; SrO 0.5-18; BaO 0-10; where CaO+SrO+BaO 8-<17; ZrO₂ 1-6; TiO₂ 0.2-5. The glass is particularly suitable as substrate glass in display technology, in particular for plasma display panels.

Claims

1. Solarization-stable aluminosilicate glass having the following composition, in % by weight, based on oxide:

space="preserve" listing-type="tabular">______________________________________ SiO.sub.2 45 -- 68 Al.sub.2 O.sub.3 9 -- 18 Na.sub.2 O 0 -- 5 K.sub.2 O >

9 -- 15 where Na.sub.2 O + Ka.sub.2 O ≧

10 CaO 0 -- 9 SrO 4.8 -- <

17 BaO 0 -- 10 where CaO + SrO + BaO 8 -- <

17 ZrO.sub.2 1 -- 6 TiO.sub.2 0.2 -- 5 ______________________________________

and, optionally refining agents in conventional amounts, provided that, apart from unavoidable contaminants in no more than trace amounts, it is free from MgO.

2. Aluminosilicate glass according to claim 1, wherein the Na₂ O/K₂ O weight ratio is at most 0.4.

3. Aluminosilicate glass according to claim 1, having the following composition in % by weight, based on oxide:

space="preserve" listing-type="tabular">______________________________________ SiO.sub.2 45-68 Al.sub.2 O.sub.3 9-18 Na.sub.2 O 0-5 K.sub.2 O >

9-15 where Na.sub.2 O + Ka.sub.2 O ≧

10 CaO 2-9 SrO 4.8-14 BaO 0-10 where CaO + SrO + BaO 8-<

17 ZrO.sub.2 1-6 TiO.sub.2 0.2-3 ______________________________________

and, optionally refining agents in conventional amounts.

4. Aluminosilicate glass according to claim 1, having the following composition in % by weight, based on oxide:

space="preserve" listing-type="tabular">______________________________________ SiO.sub.2 45-68 Al.sub.2 O.sub.3 9-18 Na.sub.2 O 0-5 K.sub.2 O >

9-15 where Na.sub.2 O + Ka.sub.2 O ≧

10 CaO 0-<

3 SrO 9.5-<

17 BaO 0-<

7.5 where CaO + SrO + BaO 12-<

17 ZrO.sub.2 1-6 TiO.sub.2 0.2-3 ______________________________________

and, optionally refining agents in conventional amounts.

5. Aluminosilicate glass according to claim 1, having the following composition in % by weight, based on oxide:

space="preserve" listing-type="tabular">______________________________________ SiO.sub.2 48-58 Al.sub.2 O.sub.3 9-15 Na.sub.2 O 1-4 K.sub.2 O 9.5-14 where Na.sub.2 O + Ka.sub.2 O 11-16 SrO 9.5-15 BaO 0-<

7.5 where SrO + BaO <

17 ZrO.sub.2 2-5 TiO.sub.2 0.5-2 ______________________________________

and, optionally refining agents in conventional amounts.

6. Aluminosilicate glass according to claim 1 wherein the Na₂ O/K₂ O weight ratio is between 0.15 and 0.35.

7. Aluminosilicate glass according to claim 1, which has been processed in a float unit, and which is, apart from unavoidable contaminants, free from PbO, As₂ O₃, Sb₂ O₃, ZnO, MgO and B₂ O₃.

8. Aluminosilicate glass according to claim 1, which additionally contains up to a total of 5% by weight of one or more components selected from the group consisting of La₂ O₃, Ta₂ O₅, Nb₂ O₅ and Y₂ O₃.

9. Aluminosilicate glass according to claim 1 which has a glass transition temperature T_g of above 650°

C., a density ρ

of less than 2.800 g/cm³ and a coefficient of thermal expansion α

_20/300 of between 8.1 and 9.0×

10^-6 /K.

10. A substrate for a flat display panel wherein the substrate comprises an aluminosilicate glass according to claim 1.

11. A plasma display panel comprising a flat transparent glass substrate which is comprised of an aluminosilicate glass according to claim 1.

12. A solar collector comprising a transparent glass substrate which is comprised of an aluminosilicate glass according to claim 1.