Glass sheet having a high IR and visible transmission with a pleasing slight colour to neutral colour
A glass sheet having a composition which comprises total iron (expressed in terms of Fe 2 O 3 ) from 0.002-0.06 wt %; chromium (expressed as Cr 2 O 3 ) from 3-75 ppm; and manganese (expressed as MnO) from 50-1,000 ppm. The glass sheet has a LTD4 higher than 70%. Such a glass sheet exhibits at once a high luminous transmission, an increased transmission of infrared (IR) radiation and a pleasing slight color or an almost neutral to neutral color.
1. A glass sheet having a composition comprising the following in weight percentage, expressed with respect to the total weight of the glass:
SiO 2 40-78%;
Al 2 O 3 0-18%;
B 2 O 3 0-18%;
Na 2 O 0-20%;
CaO 0-15%;
MgO 0-12%;
K 2 O 0-12%;
BaO 0-5%;
total iron (expressed in terms of Fe 2 O 3 ) 0.002-0.06 wt-%;
chromium (expressed as Cr 2 O 3 ) 3-75 ppm; and
manganese (expressed as MnO) 50-1,000 ppm,
wherein the glass sheet has a LTD4 higher than 70% and has a coefficient of absorption at a wavelength of 1,050 nm of less than 5 m −1 .
2. The glass sheet according to claim 1 , wherein the composition comprises: total iron 0.002-0.04 wt %.
3. The glass sheet according to claim 1 , wherein the composition comprises: total iron 0.002-0.02 wt %.
4. The glass sheet according to claim 1 , wherein the composition comprises an Fe 2+ content (expressed in the form of FeO) of less than 20 ppm.
5. The glass sheet according to claim 1 , wherein the composition comprises an Fe 2+ content (expressed in the form of FeO) of less than 5 ppm.
6. The glass sheet according to claim 1 , wherein the composition comprises: MnO≤800 ppm.
7. The glass sheet according to claim 1 , wherein the composition comprises: Cr 2 O 3 =−0.02*MnO+(Fe 2 O 3 /100)*x; x being between 15 and 30 and Cr 2 O 3 , MnO and Fe 2 O 3 being expressed in ppm.
8. The glass sheet according to claim 1 , wherein the composition comprises: Cr 2 O 3 =0.02*MnO+(Fe 2 O 3 /100)*x; x being between 15 and 30 and Cr 2 O 3 , MnO and Fe 2 O 3 being expressed in ppm.
9. The glass sheet according to claim 1 , wherein the glass sheet has a LTD4 higher than 80%.
10. The glass sheet according to claim 1 , wherein the glass sheet has a LTD4 higher than 85%.
11. The glass sheet according to claim 1 , wherein the glass sheet has a coefficient of absorption at the wavelength of 1,050 nm of less than 2 m −1 .
12. The glass sheet according to claim 1 , wherein the glass sheet has a Q factor value of Q≤5.
13. The glass sheet according to claim 1 , wherein the glass sheet has a Q factor value of Q≤4.
14. The glass sheet according to claim 1 , wherein the glass sheet has a Q factor value of Q≤3.
15. A glass sheet having a composition comprising the following in weight percentage, expressed with respect to the total weight of the glass:
SiO 2 40-78%;
Al 2 O 3 0-18%;
B 2 O 3 0-18%;
Na 2 O 0-20%;
CaO 0-15%;
MgO 0-12%;
K 2 O 0-12%;
BaO 0-5%;
total iron (expressed in terms of Fe 2 O 3 ) 0.002-0.06 wt-%;
chromium (expressed as Cr 2 O 3 ) 3-75 ppm; and
manganese (expressed as MnO) 50-1,000 ppm,
wherein the glass sheet has a LTD4 higher than 70% and has a coefficient of absorption at a wavelength of 950 nm of less than 5 m −1 .
16. A glass sheet having a composition comprising the following in weight percentage, expressed with respect to the total weight of the glass:
SiO 2 40-78%;
Al 2 O 3 0-18%;
B 2 O 3 0-18%;
Na 2 O 0-20%;
CaO 0-15;
MgO 0-12%;
K 2 O 0-12%;
BaO 0-5%;
total iron (expressed in terms of Fe 2 O 3 ) 0.002-0.06 wt-%;
chromium (expressed as Cr 2 O 3 ) 3-75 ppm; and
manganese (expressed as MnO) 50-1,000 ppm,
wherein the glass sheet has a LTD4 higher than 70% and has a coefficient of absorption at a wavelength of 850 nm of less than 5 m −1 .