Float glass composition adapted for chemical strengthening

Patent metadata

Field	Value
Publication number	US-9630873-B2
Application number	US-201514658885-A
Country	US
Kind code	B2
Filing date	Mar 16, 2015
Priority date	Mar 16, 2015
Publication date	Apr 25, 2017
Grant date	Apr 25, 2017

Abstract

Float glass compositions adapted for chemical strengthening, and methods of making the same. Certain example embodiments of this invention relate to such a glass composition having improved ion-exchanged, surface durability, and/or mechanical properties for use in applications where higher strength and improved durability of the glass are desired.

First claim

What is claimed is:

1. Float glass comprising:
a float glass composition that includes:

Ingredient
(wt. %)

SiO 2
  67-69.5%

A1 2 O 3
2.5-4.5%

(SiO 2 + A1 2 O 3 )
<73%

Na 2 O
16.6-20%  

K 2 O
0.5-2.0%

CaO
4.0-7.0%

MgO
2.5-3.5%

CaO + MgO
 6.5-10.5%

wherein the float glass is chemically strengthened and has a depth of layer, which is depth of a compressive stress layer in the glass resulting from the chemical strengthening, with a 4 hour chemical strengthening process at 435 degrees C. being used as a reference, of at least 25 μm.

2. The glass of claim 1 , wherein the float glass is chemically strengthened and has a depth of layer, which is depth of a compressive stress layer in the glass resulting from the chemical strengthening, with a 4 hour chemical strengthening process at 435 degrees C. being used as a reference, of at least 26 μm.

3. The glass of claim 1 , wherein the compressive stress layer has a maximum surface stress of from 450-550 MPa.

4. The glass of claim 1 , wherein the glass has a Young's modulus of from 74-76.5 GPa.

5. The glass of claim 1 , wherein the glass has a Young's modulus of from 74.5-75.5 GPa.

6. The glass of claim 1 , wherein the glass comprises from 67.5-68.5 SiO 2 .

7. The glass of claim 1 , wherein the glass comprises from 2.7-3.4% Al 2 O 3 .

8. The glass of claim 1 , wherein the glass comprises from 18-19% Na 2 O.

9. The glass of claim 1 , wherein the glass comprises from 5.0-7.0% CaO.

10. The glass of claim 1 , wherein the glass comprises from 5.5-6.5% CaO.

11. The glass of claim 1 , wherein the glass comprises from 2.8-3.2% MgO.

12. The glass of claim 1 , wherein the glass comprises from 7.5-10.5% CaO +MgO.

13. The glass of claim 1 , wherein the glass comprises from 8.5-9.7% CaO +MgO.

14. The glass of claim 1 , wherein CaO %/MgO % is from 1.2-2.8.

15. The glass of claim 1 , wherein in the glass the ratio CaO %/MgO % is from 1.8 to 2.3.

16. The glass of claim 1 , wherein the glass comprises from 67.5-68.5 SiO 2 , from 2.7-3.4% Al 2 O 3 , from 18-19% Na 2 O, and from 5.5-6.5% CaO.

17. The glass of claim 1 , wherein the glass has a visible transmission Lta of at least about 60%.

18. Chemically strengthened float glass comprising:
a float glass composition that is chemically strengthened and includes:

Ingredient
(wt. %)

SiO 2
  67-69.5%

A1 2 O 3
2.5-4.5%

(SiO 2 + A1 2 O 3 )
<73%

Na 2 O
16.6-20%  

K 2 O
0.5-2.0%

CaO
4.0-7.0%

MgO
2.5-3.5%

CaO + MgO
 6.5-10.5%

wherein the glass has a depth of layer, which is depth of a compressive stress layer in the glass resulting from the chemical strengthening, of at least 25 μm.

19. The glass of claim 18 , wherein the compressive stress layer has a maximum surface stress of from 450-550 MPa.

20. The glass of claim 18 , wherein the glass comprises from 67.5-68.5 SiO 2 .

21. The glass of claim 18 , wherein the glass comprises from 2.7-3.4% Al 2 O 3 .

22. The glass of claim 18 , wherein the glass comprises from 18-19% Na 2 O.

23. The glass of claim 18 , wherein the glass comprises from 5.0-7.0% CaO.

24. The glass of claim 18 , wherein the glass comprises from 5.5-6.5% CaO.

25. The glass of claim 18 , wherein the glass comprises from 67.5-68.5 SiO 2 , from 2.7-3.4% Al 2 O 3 , from 18-19% Na 2 O, and from 5.5-6.5% CaO.

Assignees

• Guardian Industries

Inventors

• Fulton Kevin R
• Mcmenamin Kirk
• Cerny Glenn A
• Wang Zhaoyu
• Olson Samuel

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

• C03C4/00

  Compositions for glass with special properties · CPC title