Grey glass composition
View Patent ↗A grey glass composition employing in its colorant portion at least iron (Fe 2 O 3 /FeO), cobalt and selenium is provided. The glass allows high visible transmission, and good IR absorption, while at the same time achieving desired grey color. In certain example embodiments, the colorant portion includes, or may consist essentially of: total iron (expressed as Fe 2 O 3 ) 0.20 to 0.35% selenium 0.0002 to 0.0020% cobalt oxide 0.0025 to 0.0060% titanium oxide 0 to 1.0% glass redox: <=.27; or 0.10 to 0.25.
1. A grey glass comprising:
a base glass portion comprising:
Ingredient
wt. %
SiO 2
67-75%
Na 2 O
10-20%
CaO
5-15%
MgO
0-7%
Al 2 O 3
0-7%
K 2 O
0-7%
and a colorant portion consisting essentially of:
total iron (expressed as Fe 2 O 3 )
0.20 to 0.35%
selenium
0.0002 to 0.0020%
cobalt oxide
0.0025 to 0.0060%
titanium oxide
less than 0.60%
wherein the grey glass contains titanium oxide and has a redox value (FeO/Fe 2 O 3 ) of no greater than 0.27, a visible transmittance (Lta) of from 59-66%, a dominant wavelength in the range of from 470 nm to 555 nm, and an excitation purity (Pe) of no greater than 5.0%.
2. The glass of claim 1 , wherein the glass has a redox value (FeO/Fe 2 O 3 ) of from 0.10 to 0.25.
3. The glass of claim 1 , wherein the glass has a dominant wavelength of from 480 to 500 nm and an excitation purity (Pe) of no greater than 4.5%.
4. The glass of claim 1 , wherein the glass has a redox value (FeO/Fe 2 O 1 ) of from 0.18 to 0.25.
5. The glass of claim 1 , wherein the glass has a % TS of no greater than 50%.
6. The glass of claim 1 , wherein said colorant portion contains:
total iron (expressed as Fe 2 O 3 )
0.23 to 0.32%
selenium
0.0003 to 0.0012%
cobalt oxide
0.0025 to 0.0055%.
7. The glass of claim 1 , wherein said colorant portion contains:
total iron (expressed as Fe 2 O 3 )
0.25 to 0.30%
selenium
0.0004 to 0.0010%
cobalt oxide
0.0035 to 0.0050%.
8. The glass of claim 1 , wherein the glass has a color characterized as follows when measured according to Ill. D65, 10 degree observer:
a*
from −1 to −4
b*
from +2 to −6
L*
from 79 to 87.
9. The glass of claim 1 , wherein the glass has a color characterized as follows when measured according to Ill. D65, 10 degree observer:
a*
from −1.5 to −3.5
b*
from 0 to −5
L*
from 80 to 86.
10. The glass of claim 1 , wherein the glass has a UV transmission of from 27-30%.
11. The glass of claim 1 , wherein the glass has an IR transmittance (% IR) of from 46-54%.
12. A grey glass comprising:
a base glass portion comprising:
Ingredient
wt. %
SiO 2
67-75%
Na 2 O
10-20%
CaO
5-15%
MgO
0-7%
Al 2 O 3
0-7%
K 2 O
0-7%
and a colorant portion comprising:
total iron (expressed as Fe 2 O 3 )
0.23 to 0.32%
selenium
0.0003 to 0.0012%
cobalt oxide
0.0025 to 0.0055%
titanium oxide
less than 0.60%.
wherein the glass is substantially free of erbium oxide, wherein the grey glass comprises titanium oxide and has, at a reference thickness of 6 mm, a redox value (FeO/Fe 2 O 3 ) of no greater than 0.27, a visible transmittance (Lta) of at least 59%, a dominant wavelength in the range of from 470 nm to 555 nm, and an excitation purity (Pe) of no greater than 5.0%.
13. The glass of claim 12 , wherein the glass has a redox value (FeO/Fe 2 O 3 ) of from 0.10 to 025.
14. The glass of claim 12 , wherein the glass has a dominant wavelength of from 480 to 500 nm and an excitation purity (Pe) of no greater than 4.5%.
15. The glass of claim 12 , wherein the glass has a redox value (FeO/Fe 2 O 3 ) of from 0.18 to 0.25.
16. The glass of claim 12 , wherein the glass has a % TS of no greater than 50%, and a visible transmittance (Lta) of from 59-66% and from 0.05-0.60% titanium oxide.
17. The glass of claim 12 , wherein said colorant portion comprises:
selenium
0.0004 to 0.0010%
cobalt oxide
0.0035 to 0.0050%.
18. The glass of claim 12 , wherein the glass has a color characterized as follows when measured according to Ill. D65, 10 degree observer:
a*
from −1 to −4
b*
from +2 to −6
L*
from 79 to 87.
19. The glass of claim 12 , wherein the glass has a color characterized as follows when measured according to Ill. D65, 10 degree observer:
a*
from −1.5 to −3.5
b*
from 0 to −5
L*
from 80 to 86.
20. The glass of claim 12 , wherein the glass is substantially free of cerium oxide.