Glass pane for use in architectural glazing, pane laminates and their use

Abstract

The invention relates to a glass sheet, in particular a glass sheet obtained by separation from a preferably floated glass ribbon formed by hot forming, in particular comprising a borosilicate glass, with a length of at least 1.15 m and a width of at least 0.85 m, with a thickness d of at least 0.5 mm, preferably at least 0.7 mm, and at most 7 mm, and uses thereof.

Claims

1. Glass pane with a length of at least 1.15 m and a width of at least 0.85 m, with a thickness d of at least 0.5 mm, comprising a top side and a bottom side, characterized by a surface fineness on the top side and/or the bottom side of less than 200 nm and by a weight per unit area (d0.7) of at most 1.73 kg/m.sup.2, a weight per unit area (d1.5) of at most 3.71 kg/m.sup.2 and a weight per unit area (d5) of at most 12.36 kg/m.sup.2.

2. Glass pane according to claim 1, characterized in that the surface fine waviness on the upper side and/or the lower side is less than 150 nm.

3. Glass pane according to claim 1, characterized by a thickness d of more than 2 mm.

4. Glass pane according to claim 1, characterized by a thickness d of at most 2 mm.

5. Glass pane according to claim 1, characterized by a basis weight (d0.7) of at least 1.45 kg/m.sup.2, a basis weight (d1.5) of at least 3 kg/m.sup.2 and a basis weight (d5) of at least 10 kg/m.sup.2.

6. Glass pane according to claim 1, characterized in that it has a light transmission Y) (D65.2?), measured at a thickness d=5 mm, of at least 91%.

7. Glass pane according to claim 1, characterized in that, measured at a thickness d=5 mm, it has a transmission of at least 91% at the wavelength 850 nm.

8. Glass pane according to claim 1, characterized by a density of less than 2.50 g/cm.sup.3.

9. Glass pane according to claim 1, characterized by a density of at least 2.10 g/cm.sup.3.

10. Glass pane according to claim 1, comprising a borosilicate glass, preferably comprising the following components in % by weight: TABLE-US-00009 SiO.sub.2 70 to 87 B.sub.2O.sub.3 5 to 25 Al.sub.2O.sub.3 0 to 6 Na.sub.2O 0.5 to 9 K.sub.2O 0 to 3 CaO 0 to 3 MgO 0 to 2. Li.sub.2O 0 to 5 R.sub.xO.sub.y 0 to 3, where R=Sr, Ba, Zn, Ti, Zr, P, Sn, S, Ce, Fe, Nd and 1?X?2; 1?Y?5.

11. Glass pane according to claim 10, characterized in that at 3.8 mm it has a temperature quenching strength (ASF) of at least 170 K (5% fractile), preferably at least 175 K (5% fractile).

12. Glass pane according to claim 10, characterized in that it has a temperature gradient strength (TGF) of at least 110 K (T.sub.zug) and/or at least 120 K (T.sub.heiz) at 3.8 mm.

13. Glass pane according to claim 10, characterized in that it is chemically or thermally toughened.

14. Glass pane according to claim 10, wherein the glass pane is a float glass pane.

15. Pane composite comprising at least two glass panes, of which at least one is the glass pane of claim 1.

16. A glazing comprising the glass pane of claim 15.

17. The glazing according to claim 16, wherein at least a side of the glass pane facing a liquid crystal unit has a surface fine wavelength of less than 200 nm.

18. The glazing according to claim 16, wherein a side of the glass pane facing an atmospheric side of the float bath during a float process faces a liquid crystal unit.

Description

EXAMPLES

[0091] In the table, examples of design examples (designation starting with A) and a comparative example (designation starting with V) are given.

[0092] The table contains the composition of the examples in % by weight on an oxide basis. The remainder comprises components not previously mentioned, in particular RxOy, where R=Sr, Ba, Zn, Ti, Zr, P, Sn, S, Ce, Fe, Nd and 1? X?2 1?Y?5.

[0093] The table also contains the following properties of the examples: [0094] the density ? in g/cm.sup.3, [0095] the coefficient of expansion CTE.sub.20-300 in 10/K,.sup.?6 [0096] the coefficient of expansion CTEliquid in 10/K.sup.?6 [0097] and the difference .sub.CTEliquid?CTE.sub.20-300 in 10.sup.?6/K, [0098] the light transmission Y (D65.2?) in %, measured according to DIN 5033 in the CIE color system on a sample with a thickness of 5 mm or on the pane with the thickness of the respective example, [0099] the transmission T at a wavelength of 850 nm, measured with standard light C, 2? on a fire-polished sample with a thickness of 5 mm or on the disk with the thickness of the respective example, [0100] Length, width and thickness of the pane, [0101] the Weight per unit area (dx) for the thicknesses 0.7 mm (d0.7), 1.5 mm (d1.5) and 5 mm (d5) in kg/m.sup.2, whereby to determine the respective weight per unit area, a pane of the corresponding thickness in the format 50?50 cm was weighed and the result converted to 1 m. To determine the respective basis weight, a sheet of the corresponding thickness in the format 50?50 cm.sup.2 was weighed and the result was converted to 1 m.sup.2 or the sheet of a different thickness, namely the thickness specified in the table, was used and the result was converted to the thickness considered according to (d0.7), (d1.5) and (d5); [0102] the surface fine waviness W.sub.fpd in nm, the length in mm over which the measurement was taken, the thickness in mm at which the measurement was taken; [0103] the temperature quenching strength ASF in K (5% fractile) for samples with the specified thickness; [0104] the temperature gradient strength TGF in K (5% fractile) for samples with the specified thickness, both with sudden temperature application (T.sub.zug) and with continuous heating (T.sub.heiz).

TABLE-US-00006 TABLE 1 Addition [% by weight] A1 A2 A3 A4 A5 A6 A7 A8 V1 SiO.sub.2 72 82 81 81 78 67 67 62 72 B O.sub.23 25 15 15 13 10 4 10 Al O.sub.23 1 1 1 2 3 17 11 16 Li O.sub.2 4 Na O.sub.2 1 1 3 4 3 2 12 14 K O.sub.2 1 1 1 3 4 MgO 2 1 5 4 3 CaO 3 3 6 10 Rest 0 0 0 0 0 2 1 1 0 Total 100 100 100 100 100 100 100 100 100 Density 2.13 2.17 2.18 2.22 2.31 2.39 2.43 2.46 2.50 [g/cm].sup.3 CTE.sub.20-300 3.29 2.57 2.77 3.25 4.15 5.5 3.15 8.7 9 [10.sup.?6/K] .sub.CTEliquid 4.1 9.7 26.7 [10.sup.?6/K] .sub.CTEliquid ? 1.97 6.45 22.55 CTE.sub.20-300 [10.sup.?6/K] Y (D65.2?) 93 93 92 91 [%] (for (5.02) (4.91) (5.00) (4.89) d = . . . mm) T 850 nm 93 93 92 84 [%] (at (5.02) (4.91) (5.00) (4.89) d = . . . mm) W.sub.fpd [nm] 38 32 85 68 58 Meas. 20 20 20 20 20 length [mm] Gem. with a 2.25 6 0.7 0.7 0.7 thickness d .sub.(thermally [mm] .sub.prestressed) ASF [K] 192 >350 30 5% fractile (3.8) (5) (4) (at .sub.(thermally d = . . . mm) .sub.prestressed) TGF: T.sub.heiz 123 >350 40 [K] 5% (3.8) (5) (4) fractile (at .sub.(thermally d = . . . mm) .sub.prestressed)

[0105] The examples illustrate very clearly that the choice of glass leads to different surface weights, which can be used for thicker and therefore more stable products with the same weight (see Table 2) or for lighter products with the same thickness (see Table 3).

TABLE-US-00007 TABLE 2 A1 A2 A3 A4 A5 A6 A7 A8 V1 Density [g/cm.sup.3] 2.13 2.17 2.18 2.23 2.31 2.39 2.43 2.46 2.5 Thickness [mm] Weight per unit area kg/m.sup.2 0.7 1.49 1.52 1.53 1.56 1.62 1.67 1.70 1.72 1.75 1.5 3.20 3.26 3.27 3.35 3.47 3.59 3.65 3.69 3.75 5 10.65 10.85 10.90 11.15 11.55 11.95 12.15 12.30 12.50 Possible thickness with basis weight of V1 [mm] ?> Stability gain compared to V1 0.82 0.81 0.80 0.78 0.76 0.73 0.72 0.71 0.70 1.76 1.73 1.72 1.68 1.62 1.57 1.54 1.52 1.50 5.87 5.76 5.73 5.61 5.41 5.23 5.14 5.08 5.00

TABLE-US-00008 TABLE 3 A1 A2 A3 A4 A5 A6 A7 A8 V1 Density [g/cm.sup.3] 2.13 2.17 2.18 2.23 2.31 2.39 2.43 2.46 2.5 Thickness [mm] Weight per unit area kg/m.sup.2 0.7 1.49 1.52 1.53 1.56 1.62 1.67 1.70 1.72 1.75 1.5 3.20 3.26 3.27 3.35 3.47 3.59 3.65 3.69 3.75 5 10.65 10.85 10.90 11.15 11.55 11.95 12.15 12.30 12.50 Weight saving compared to V1 [%] with the same thickness (i.e. comparable stability) 14.80% 13.20% 12.80% 10.80% 7.60% 4.40% 2.80% 1.60%

[0106] In one embodiment of the invention, at least two glass panes, of which at least one glass pane according to the invention, preferably at least two glass panes according to the invention, form a pane composite.

[0107] Such a pane laminate can consist of two glass panes that are connected via spacers, for example so-called warm-edge spacers, and one or more sealants.

[0108] Such a pane assembly can also consist of more than two panes of glass, for example with a central third pane.

[0109] The pane composite with at least one glass pane according to the invention can also be laminated from glass panes, films and/or other materials, whereby the panes, the films and/or the other materials can be applied to a monolithic pane or a pane composite.

[0110] The glass panes of the pane laminate can have different compositions and/or different thicknesses and/or different surface wavinesses on their upper and/or lower sides. The glass panes of the pane laminate can also have the same composition and/or the same thickness and/or the same surface waviness.

[0111] One advantage of using a pane according to the invention, in particular a glass pane with the same composition, for both the front and the back of a display device or smart window is that it eliminates potential problems that can arise from different thermal expansion coefficients of the front and back glass.

[0112] The panes of the pane laminate can be coated, for example with a TCO coating on the inside of the space formed by the laminate.

[0113] The basis weight of the laminate is the sum of the basis weights of the individual panes and connecting films:

[00001]${\mathrm{grammage}}_{\mathrm{Verbund}}={?}_1*d_1+.Math.+{?}_n*d_n$

[0114] In one embodiment of the invention, the glass pane or pane composite according to the invention is used in glazing, in particular in architectural glazing of buildings, for smart window, switchable window, privacy window applications, in particular in suspended particle devices (so-called SPD), or having electrochromic layers, or for liquid crystal units, including so-called PDLC(=particle dispersed liquid crystal).

[0115] The technical term smart windows refers to intelligent or thinking windowsnamely windows with glazing that can change their properties according to the user's needs. Transparency, translucency, color and reflectivity can be reversibly adjusted depending on environmental influences such as direct sunlight. Many of these switchable and adjustable glazings are based on the use of liquid crystals in the space between the panes, i.e. in the space formed by the pane composite.

[0116] Energy-saving windows use solar radiation to generate electricity. Switchable windows provide solar shading and help to reduce energy costs and CO emissions..sub.2

[0117] Privacy windows, which instantly change from transparent to translucent, make blinds in buildings superfluous and provide more privacy.

[0118] Darkening and heat-insulating systems are preferably implemented using electrochromic devices or suspended particle devices. They change from transparent to dark when in use, thus keeping the sun out of the interior of the building and helping to reduce energy costs. Liquid crystal solutions, on the other hand, are used more as privacy windows. They change from transparent to white.

[0119] In one embodiment of the invention, the glass pane or pane composite according to the invention is used in glazing, in particular architectural glazing of buildings for energy generation by transparent solar windows. In a further embodiment of the invention, the glass pane or pane composite according to the invention is used in glazing, in particular architectural glazing, as a combination, e.g. by using the energy of the solar windows to operate switchable windows.

[0120] In one embodiment of the invention, the glass pane or the pane composite according to the invention is used in glazing, in particular in architectural glazing of buildings, in particular for liquid crystal units, for smart window, switchable window, privacy window applications, in such a way that at least the side of the glass pane or the glass panes facing the liquid crystal unit has a surface fine wavelength of less than 200 nm, preferably less than 150 nm, particularly preferably less than 100 nm, very particularly preferably less than 50 nm.

[0121] Thus, one advantage of the invention, namely the good surface fine waviness, is particularly effective, as it reduces optical distortions and supports compact and thus possibly more cost-effective designs of the glazing.

[0122] In one embodiment of the invention, the glass pane according to the invention or at least one glass pane of the pane laminate is a float glass pane, preferably made of alkali-containing borosilicate glass, and the glass pane according to the invention or the pane laminate is used in glazing, in particular in architectural glazing of buildings, in particular for liquid crystal units, for smart window, switchable window, privacy window applications, and also for TFT-LCD and electrochromic devices in such a way that the side of the glass pane or panes facing the atmospheric side of the float bath during the float process faces the liquid crystal unit.

[0123] Thus, an advantage of this preferred embodiment comes into play, which is based on the fact that in a floated alkali-containing glass, in particular a borosilicate glass, the side of the glass that comes into contact with the bath metal (usually tin) and the side of the glass that comes into contact with the atmosphere above the float bath (atmosphere side) have a different diffusion behavior with regard to the alkali ions. The alkali ions on the atmosphere side of the glass diffuse from the surface only to such a small extent that such a glass plate can be used as a pane in a flat display device or as a substrate for thin-film PV cells without any further post-treatment to reduce the alkali ion content in the surface if it is installed in such a way that its atmosphere side faces the electrically excitable optically active layer. Depending on the end application, no passivation layers are required.

[0124] The structure of a TFT-LCD flat panel display with at least one float glass panel according to the invention is described below as an example. The front panel is formed by a glass plate generally referred to as a color filter plate. At least this is a glass pane according to the invention. The rear end of the screen is formed by the glass pane known as the back plate. It can also be designed as a glass pane according to the invention. The liquid crystal layer is located between the front pane (color filter plate) and the back plate. The exact distance between the two panes is ensured by spacers. Preferably, at least the front pane is arranged in the display in such a way that the side facing inwards towards the liquid crystal layer has a surface fine wavelength of less than 200 nm.

[0125] Preferably, at least the front pane is a float glass pane and is arranged in the display in such a way that its surface which came into contact with the tin bath during manufacture according to the float process faces outwards, while the atmospheric side of the pane which came into contact with the atmosphere above the float bath during manufacture faces inwards towards the liquid crystal layer.

[0126] The front screen and back plate are provided with polarizer layers on their outer sides. The front screen has a black matrix on its underside, a color filter layer for the colors red, green and blue and a transparent common electrode, which usually consists of an ITO layer. The back plate carries a thin-film transistor that drives a pixel electrode. An alignment layer is also arranged on the front screen and the back plate. The display is sealed towards the edge by means of a gasket. The common electrode of the front panel is electrically connected to the common electrode of the back plate by means of the connector (short). If the pixel electrode is controlled by the TFT transistor, the liquid crystals of the relevant pixel in the liquid crystal layer rotate and the relevant pixel is activated.

[0127] The glass panes, pane laminates and glazing described can also be components of systems such as those known for fire-resistant glazing.

[0128] It is understood that the advantages of the invention described in the embodiment examples for individual panes are particularly effective for pane assemblies.