Clear glass composition with high visible transmittance
View Patent ↗A high transmittance fairly clear/neutral colored glass composition is provided. An oxidizing agent(s) such as cerium oxide (e.g., CeO 2 ) or the like is added to the glass batch in order to realize very oxidized conditions (i.e., to significantly lower the redox of the resulting glass). As a result of the oxidizing agent(s) used in the batch, the iron is oxidized to a very low FeO (ferrous state) content. For example, this may result in a glass having a glass redox value of no greater than 0.12 (more preferably <=0.10; even more preferably <=0.08; and most preferably <=0.05) and a % FeO (i.e., ferrous content) of from 0.0001 to 0.05%. In certain example embodiments, in order to compensate for yellow or yellow-green coloration a small amount of cobalt (Co) may be provided in the glass to enable it to realize a more neutral color.
1. Glass comprising:
SiO 2
at least 67%
Na 2 O
10 to 20%
CaO
5 to 15%
MgO
0 to 8%
Al 2 O 3
0 to 5%
K 2 O
0 to 5%
total iron (expressed Fe 2 O 3 ):
0.01 to 0.20%
glass redox:
<=0.12
chromium oxide:
1 to 5 ppm
wherein the glass has a visible transmission of at least about 85%, is decolorized so as to have a* and b* values from −0.5 to +0.5, and wherein the glass has no cerium oxide.
2. The glass of claim 1 , comprising:
total iron (expressed Fe 2 O 3 ): 0.01 to 0.15%
cobalt oxide: 0.3 to 10 ppm
glass redox: <=0.08.
3. The glass of claim 1 , further comprising from 0 to 0.2% titanium oxide.
4. The glass of claim 1 , wherein the glass has a visible transmission of at least 88%.
5. The glass of claim 1 , wherein the glass has a visible transmission of at least 90%.
6. Glass comprising:
SiO 2
at least 67%
Na 2 O
10 to 20%
CaO
5 to 15%
MgO
0 to 8%
Al 2 O 3
0 to 5%
K 2 O
0 to 5%
total iron (expressed Fe 2 O 3 ):
0.01 to 0.20%
glass redox:
<=0.12
chromium oxide:
1 to 5 ppm
wherein the glass has a visible transmission of at least about 85%, is decolorized so as to have a* and b* values from −0.5 to +0.5, and wherein the glass has 0.05-0.2% cerium oxide.
7. The glass of claim 6 , comprising:
total iron (expressed Fe 2 O 3 ):
0.01 to 0.15%
cobalt oxide:
0.3 to 10 ppm
glass redox:
< =0.08.
8. The glass of claim 6 , further comprising from 0 to 0.2% titanium oxide.
9. The glass of claim 6 , wherein the glass has a visible transmission of at least 88%.
10. The glass of claim 6 , wherein the glass has a visible transmission of at least 90%.