Glass sheet with high near-IR transmission and very low visible transmission
A glass sheet having a high near-IR transmission and very low visible transmission. The glass sheet is a silicate-type and has a composition that includes, in a content expressed as weight percentages, by total weight of glass: total iron (expressed as Fe 2 O 3 ) 0.02-1%, Chromium (expressed as Cr 2 O 3 ) 0.05-0.8%, Cobalt (expressed as Co) 0.03-0.175%. The glass sheet shows, intrinsically, a very low visible transmission together with a high IR transmission at wavelengths of interest (i.e. 850, 900 and 950 nm) and low amounts of Cr 6+ species. The glass sheet is therefore valuable within the context of autonomous cars and in particular, those with fully integrating LiDAR systems.
1 . A glass sheet of silicate-type comprising, in a content expressed as weight percentages, by total weight of 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
0-10%;
K 2 O
0-10%;
BaO
0-5%;
total iron (expressed as Fe 2 O 3 )
0.02-0.667%;
Chromium (expressed as Cr 2 O 3 )
0.05-0.8%;
and
Cobalt (expressed as Co)
0.03-0.175%,
and
wherein:
Cr 2 O 3 <1-5.5*Co, and
1.2<Cr 2 O 3 /Fe 2 O 3 ≤2.7, and
wherein the glass sheet has a T 850 higher than 80%.
2 . The glass sheet according to claim 1 , wherein the composition comprises: chromium (expressed as Cr 2 O 3 )≤0.5%.
3 . The glass sheet according to claim 1 , wherein the composition comprises: chromium (expressed as Cr 2 O 3 )≤0.3%.
4 . The glass sheet according to claim 1 , wherein the composition comprises: chromium (expressed as Cr 2 O 3 )≥0.1%.
5 . The glass sheet according to claim 1 , wherein the composition comprises: total iron (expressed as Fe 2 O 3 )≤0.4%.
6 . The glass sheet according to claim 1 , wherein the composition comprises: total iron (expressed as Fe 2 O 3 )≥0.04%.
7 . The glass sheet according to claim 1 , wherein the composition comprises: total iron (expressed as Fe 2 O 3 )≥0.06%.
8 . The glass sheet according to claim 1 , wherein the composition comprises: cobalt (expressed as Co)≤0.12%.
9 . The glass sheet according to claim 1 , wherein the composition comprises an Fe 2+ content (expressed in the form of FeO) of less than 40 ppm.
10 . The glass sheet according to claim 1 , wherein the glass sheet comprises a TLD4 lower than 10%.
11 . A glass sheet of silicate-type comprising, in a content expressed as weight percentages, by total weight of 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
0-10%;
K 2 O
0-10%;
BaO
0-5%;
total iron (expressed as Fe 2 O 3 )
0.06-0.667%;
Chromium (expressed as Cr 2 O 3 )
0.05-0.8%;
and
Cobalt (expressed as Co)
0.03-0.175%,
and
wherein:
Cr 2 O 3 <1-5.5*Co, and
1.2<Cr 2 O 3 /Fe 2 O 3 ≤2.7, and
wherein the glass sheet has a TLD4 lower than 8%.
12 . The glass sheet according to claim 11 , wherein the composition comprises: chromium (expressed as Cr 2 O 3 )≤0.5%.
13 . The glass sheet according to claim 11 , wherein the composition comprises: chromium (expressed as Cr 2 O 3 )≤0.3%.
14 . The glass sheet according to claim 11 , wherein the composition comprises: chromium (expressed as Cr 2 O 3 )≥0.1%.
15 . The glass sheet according to claim 11 , wherein the composition comprises: total iron (expressed as Fe 2 O 3 )≤0.4%.
16 . The glass sheet according to claim 11 , wherein the composition comprises an Fe 2+ content (expressed in the form of FeO) of less than 40 ppm.
17 . The glass sheet according to claim 11 , wherein the glass sheet comprises a T 850 higher than 80%.
18 . A glass sheet of silicate-type comprising, in a content expressed as weight percentages, by total weight of 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
0-10%;
K 2 O
0-10%;
BaO
0-5%;
total iron (expressed as Fe 2 O 3 )
0.02-0.667%;
Chromium (expressed as Cr 2 O 3 )
0.1-0.8%;
and
Cobalt (expressed as Co)
0.03-0.175%,
and
wherein:
Cr 2 O 3 <1-5.5*Co, and
1.2<Cr 2 O 3 /Fe 2 O 3 ≤2.7, and
the glass sheet comprises no colorants other than total iron, chromium, and cobalt, except that other colorants may be present as impurities.
19 . The glass sheet according to claim 18 , wherein the glass sheet comprises a TLD4 lower than 10%.
20 . The glass sheet according to claim 18 , wherein the glass sheet comprises a T 850 higher than 80%.