Glass composition including sulfides having low visible and IR transmission
View Patent ↗A soda-lime-silica based privacy glass, having a visible transmission (Lta) of no greater than 25% and an infrared (IR) transmission no greater than 25%, includes the following colorants in addition to the base glass: total iron (expressed as Fe 2 O 3 ): 0.1 to 1.0% cobalt oxide (e.g., Co 3 O 4 ): 0 to 1,000 ppm sulfides (S 2− ): 0.0001 to 0.10%. In certain other embodiments the visible transmission may be higher, but low IR transmission is still realized.
1. A glass sheet comprising:
a base glass portion comprising:
Ingredient
Wt. %
SiO 2
67-75%
Na 2 O
10-20%
CaO
5-15%
MgO
0-8%
Al 2 O 3
0-5%
K 2 O
0-5%
BaO
0-2%
and a colorant portion comprising:
total iron:
0.1 to 1.0%
cobalt oxide:
0 to 1,000 ppm
sulfides (S 2− ):
0.0001 to 0.10%
wherein the glass sheet has a visible transmission (Lta) no greater than 25%, an ultraviolet (UV) transmission no greater than 20%, and an infrared (IR) transmission no greater than 25%.
2. The glass of claim 1 , wherein the colorant portion comprises:
total iron:
0.2 to 0.8%
cobalt oxide:
0 to 1,000 ppm
sulfides (S 2− ):
0.001 to 0.10%.
3. The glass of claim 1 , wherein the colorant portion comprises:
total iron:
0.3 to 0.6%
cobalt oxide:
0 to 1,000 ppm
sulfides (S 2− ):
0.002 to 0.10%.
4. The glass of claim 1 , wherein the colorant portion comprises from 0.3 to 0.6% total iron.
5. The glass of claim 1 , wherein the glass has a redox value (FeO/Fe 2 O 3 ) of from 0.4 to 0.9.
6. The glass of claim 1 , wherein the glass has a redox value (FeO/Fe 2 O 3 ) of from 0.5 to 0.85.
7. The glass of claim 1 , wherein the glass has a redox value (FeO/Fe 2 O 3 ) of from 0.6 to 0.80.
8. The glass of claim 1 , wherein the glass sheet has a visible transmission (Lta) no greater than 20%, and an infrared (IR) transmission no greater than 20%.
9. The glass of claim 1 , wherein the colorant portion comprises:
total iron:
0.2 to 0.8%
cobalt oxide:
0 to 1,000 ppm
sulfides (S 2− ):
0.001 to 0.5%
selenium (Se):
0 to 0.0020%
chromium oxide:
0 to 0.010%
erbium oxide:
0 to 0.010%
nickel oxide:
0 to 0.005%.
10. The glass of claim 1 , wherein the colorant portion comprises:
total iron:
0.3 to 0.6%
cobalt oxide:
20 to 800 ppm
sulfides (S 2− ):
0.001 to 0.5%
selenium (Se):
0 to 0.001%
chromium oxide:
0 to 0.001%
erbium oxide:
0 to 0.001%
nickel oxide:
0 to 0.001%.
11. The glass of claim 1 , wherein the colorant portion comprises:
total iron:
0.3 to 0.6%
cobalt oxide:
20 to 800 ppm
sulfides (S 2− ):
0.001 to 0.5%
selenium (Se):
0 to 0.0001%
chromium oxide:
0 to 0.0001%
erbium oxide:
0 to 0.0001%
nickel oxide:
0 to 0.0001%.
12. The glass of claim 1 , wherein the glass sheet is dull grayish/greenish in color, and is characterized by a % TS of no greater than 20%.
13. The glass sheet of claim 1 , wherein the glass sheet has an L* of from 30-60, an a* value of from −20 to 0 and a b* value of from −10 to +45.
14. A glass sheet comprising:
a base glass portion comprising:
Ingredient
Wt. %
SiO 2
67-75%
Na 2 O
10-20%
CaO
5-15%
MgO
0-8%
Al 2 O 3
0-5%
K 2 O
0-5%
BaO
0-2%
and a colorant portion consisting essentially of:
total iron:
0.2 to 0.8%
cobalt oxide:
0 to 1,500 ppm
sulfides (S 2− ):
0.0001 to 1%
selenium (Se):
0 to 0.0020%
chromium oxide:
0 to 0.010%
erbium oxide:
0 to 0.010%
nickel oxide:
0 to 0.005%
wherein the glass sheet has a visible transmission (Lta) no greater than 25%, an ultraviolet (UV) transmission no greater than 20%, and an infrared (IR) transmission no greater than 25%.
15. The glass of claim 14 , wherein the colorant portion consists essentially of:
total iron:
0.2 to 0.8%
cobalt oxide:
0 to 1,000 ppm
sulfides (S 2− ):
0.001 to 0.50%
selenium (Se):
0 to 0.0010%
chromium oxide:
0 to 0.001%
erbium oxide:
0 to 0.001%
nickel oxide:
0 to 0.001%.
16. The glass of claim 14 , wherein the colorant portion consists essentially of:
total iron:
0.3 to 0.6%
cobalt oxide:
20 to 800 ppm
sulfides (S 2− ):
0.001 to 0.50%
selenium (Se):
0 to 0.0001%
chromium oxide:
0 to 0.001%
erbium oxide:
0 to 0.001%
nickel oxide:
0 to 0.001%.
17. The glass of claim 14 , wherein the colorant portion consists essentially of:
total iron:
0.3 to 0.6%
cobalt oxide:
20 to 800 ppm
sulfides (S 2− ):
0.001 to 0.50%.
18. The glass of claim 14 , wherein the colorant portion has from 0.3 to 0.6% total iron.
19. The glass of claim 14 , wherein the glass has a redox value (FeO/Fe 2 O 3 ) of from 0.4 to 0.9.
20. The glass of claim 14 , wherein the glass has a redox value (FeO/Fe 2 O 3 ) of from 0.5 to 0.85.
21. The glass of claim 14 , wherein the glass sheet has a visible transmission (Lta) no greater than 20%, and an infrared (IR) transmission no greater than 20%.
22. The glass of claim 21 , wherein the glass sheet has an ultraviolet (UV) transmission no greater than 20%.
23. The glass sheet of claim 14 , wherein the glass sheet has an L* of from 30-60, an a* value of from −20 to 0 and a b* value of from −10 to +45.
24. A glass sheet having a visible transmission no greater than 25%, an ultraviolet (UV) transmission no greater than 20%, and an infrared (IR) transmission no greater than 25%, the glass sheet including a colorant portion consisting essentially of:
total iron:
0.2 to 0.8%
cobalt oxide:
0 to 1,500 ppm
sulfides (S 2− ):
0.0001 to 1%.
25. The glass of claim 24 , wherein the colorant portion consists essentially of:
total iron:
0.3 to 0.6%
cobalt oxide:
20 to 800 ppm
sulfides (S 2− ):
0.001 to 0.5%.
26. The glass of claim 24 , wherein the glass sheet has a visible transmission no greater than 20%, an IR transmission no greater than 20%, and a % TS no greater than 20%.
27. The glass sheet of claim 24 , wherein the glass sheet has an L* of from 30-60, an a* value of from −20 to 0 and a b* value of from −10 to +45.
28. A method of making privacy glass, the method comprising:
causing a batch melt including soda, lime, silica, iron and Na 2 SO 4 to have a negative batch redox value; and
processing the batch so as to form a privacy glass having a visible transmission no greater than 25% and in infrared (IR) transmission no greater than 25%, wherein the privacy glass includes a colorant portion comprising:
total iron:
0.2 to 0.8%
cobalt oxide:
0 to 1,500 ppm
sulfides (S 2− ):
0.0001 to 1%.
29. The method of claim 28 , wherein at least part of the iron added to the batch is added to the batch in the form of melite.
30. The method of claim 28 , wherein all iron added to the batch is added in the form of melite.
31. The method of claim 28 , wherein the glass contains sulfides (S 2− ) from 0.0001 to 0.10%.