Glazing in particular for motor vehicle roof panel
Disclosed are laminated glazings with low light transmission for use in motor vehicles. The glazings include at least two glass sheets assembled by means of a thermoplastic interlayer sheet, which have a light transmission (TL) less than 35%, an energy transmission less than 15%, and calorimetric characteristics such that on the CIE chromaticity diagram it is included within the perimeter defined by the co-ordinate points: B(0.2600; 0.3450); F(0.3300; 0.3300);
1 . Glazing with low light transmission for use in motor vehicles comprising at least two glass sheets assembled by means of a thermoplastic interlayer sheet, which has a light transmission (LT) of less than 35%, an energy transmission of less than 15% and calorimetric characteristics such that on the CIE chromaticity diagram it is included within the perimeter defined by the coordinate points: B(0.2600; 0.3450); F(0.3300; 0.3300); G(0.3150; 0.2900); H(0.2350; 0.2750).
2 . Glazing according to claim 1 , having a light transmission (LT) of less than 25%.
3 . Glazing according to claim 1 having an energy transmission (ET) of less than 10%.
4 . Glazing according to claim 1 having a thickness no greater than 6.5mm.
5 . Glazing according to claim 1 having a thickness no greater than 5.5mm.
6 . Glazing according to claim 1 having an energy transmission (ET) of less than 8%.
7 . Glazing according to claim 1 having a light transmission (LT) of less than 20%.
8 . Glazing according to claim 1 , which is included within the perimeter of B′ (0.2650; 0.3350); F′ (0.3200; 0.3200); G′ (0.3100; 0.3000); H′ (0.2500; 0.2900) on the CIE chromaticity diagram.
9 . Glazing according to claim 8 , which is included within the perimeter of B″ (0.2800; 0.3300); F″ (0.3089; 0.3225); G″ (0.2890; 0.2975); H″ (0.2600; 0.2930) on the CIE chromaticity diagram.
10 . Glazing according to claim 1 , having a light transmission (LT) not less than 10%.
11 . Glazing according to claim 1 , wherein at least one of the glass sheets has purity of light stimulus (P) and colour rendition index (R) characteristics which meet the following conditions:
P<20%
R>−P+80%.
12 . Glazing according to claim 11 , wherein the glass sheet meeting the indicated conditions has a colour rendition index greater than 70%.
13 . Glazing according to claim 1 , wherein the sheets of glass and of thermoplastic material are selected such that the colour rendition index of the glazing is at least equal to 70%.
14 . Glazing according to claim 13 , wherein the sheets of glass and of thermoplastic material are selected such that the colour rendition index of the glazing is greater than 75%.
15 . Glazing according to claim 1 comprising at least one glass sheet with the general composition:
SiO 2
60-75%
Al 2 O 3
0-5%
Na 2 O
10-20%
BaO
0-2%
CaO
0-16%
BaO + CaO + MgO
10-20%
K 2 O
0-10%
K 2 O + Na 2 O
10-20%
MgO
0-10%
and comprising the following as chromophore constituents:
Fe 2 O 3
1-1.65%
Co
0.017-0.030%
Se
0.001-0.0100%.
16 . Glazing according to claim 1 comprising at least one glass sheet with the general composition:
SiO 2
60-75%
Al 2 O 3
0-5%
Na 2 O
10-20%
BaO
0-2%
CaO
0-16%
BaO + CaO + MgO
10-20%
K 2 O
0-10%
K 2 O + Na 2 O
10-20%
MgO
0-10%
and comprising the following as chromophore constituents:
Fe 2 O 3
0.75-1.8%
Co
0.0040-0.0180%
Se
0.0003-0.0040%
Cr 2 O 3
0.0010-0.0100%.
17 . Glazing according to claim 1 comprising at least one glass sheet with the general composition:
SiO 2
60-75%
Al 2 O 3
0-5%
Na 2 O
10-20%
BaO
0-2%
CaO
0-16%
BaO + CaO + MgO
10-20%
K 2 O
0-10%
K 2 O + Na 2 O
10-20%
MgO
0-10%
and comprising the following as chromophore constituents:
Fe 2 O 3 (total iron)
1.1-1.8%
FeO
0.30-0.50%
Co
0.0030-0.0270%
Cr 2 O 3
0-0.1000%
V 2 O 5
0-0.0500%
CeO 2
0-0.5%
TiO 2
0-1.5%
Se
0-0.0100%.
18 . Glazing according to claim 1 comprising at least one glass sheet with the general composition:
SiO 2
60-75%
Al 2 O 3
0-5%
Na 2 O
10-20%
BaO
0-2%
CaO
0-16%
BaO + CaO + MgO
10-20%
K 2 O
0-10%
K 2 O + Na 2 O
10-20%
MgO
0-10%
and comprising the following as chromophore constituents:
Fe 2 O 3 (total iron)
1.2-1.85%
FeO
0.40-0.50%
Co
0.0020-0.013%
Cr 2 O 3
0-0.1%
V 2 O 5
0-0.1%
Se
0-0.0015%.
19 . Glazing according to claim 1 comprising at least one glass sheet with the general composition:
SiO 2
60-75%
Al 2 O 3
0-5%
Na 2 O
10-20%
BaO
0-2%
CaO
0-16%
BaO + CaO + MgO
10-20%
K 2 O
0-10%
K 2 O + Na 2 O
10-20%
MgO
0-10%
and comprising the following as chromophore constituents:
Fe 2 O 3 (total iron)
1.2-1.8%
FeO
0.25-0.35%
Co
0.0020-0.010%
Cr 2 O 3
0.001-0.0100%
CeO 2
0.1-0.8%.
20 . Glazing according to claim 1 comprising at least one glass sheet with the general composition:
SiO 2
60-75%
Al 2 O 3
0-5%
Na 2 O
10-20%
BaO
0-2%
CaO
0-16%
BaO + CaO + MgO
10-20%
K 2 O
0-10%
K 2 O + Na 2 O
10-20%
MgO
0-10%
and comprising the following as chromophore constituents:
Fe 2 O 3 (total iron)
0.9-1.8%
FeO
0.25-0.40%
Co
0.0010-0.0100%
Cr 2 O 3
0-0.1%
V 2 O 5
0-0.2%.
21 . Glazing according to claim 1 comprising at least one sunshield layer based on a conductor oxide of the group comprising tin oxides doped with fluorine or antimony, or oxides of indium and tin.
22 . Glazing according to claim 1 comprising at least one silver-based sunshield layer assembly.
23 . Glazing according to claim 1 comprising a composite interlayer sheet which has a silver-based sunshield layer assembly.
24 . Glazing according to claim 1 comprising a colored thermoplastic interlayer sheet.
25 . Glazing according to claim 1 wherein the glass sheets are semi-toughened.
26 . Glazing according to claim 1 forming part of at least one motor vehicle roof panel.