WO2004055296A2

WO2004055296A2 - Spandrel

Info

Publication number: WO2004055296A2
Application number: PCT/EP2003/014498
Authority: WO
Inventors: Andreas Heft; Andreas Pfuch; Bernd Grünler; Uwe Kriltz
Original assignee: C.R.V.C. S.A.
Priority date: 2002-12-18
Filing date: 2003-12-18
Publication date: 2004-07-01
Also published as: DE10259295B4; WO2004055296A3; DE10259295A1

Abstract

The present invention relates to a spandrel, in particular for a building, comprising a glass substrate (1), an interference layer (2, 3) arranged on the glass substrate (1) an intermediate layer (4a, 4b) arranged on the interference layer (2, 3) and a ceramic layer (5) arranged on the intermediate layer (4a, 4b).

Description

Spandrel

1. Technical field:

The present invention relates to a spandrel, a combination of a spandrel and a window and to a method for manufacturing a spandrel.

2. The prior art:

In modern architecture there is the need to design buildings in an visually homogenous manner so that a substantially constant color and reflection impression is obtained independent from whether a part of the outer surface of the building is provided as a window or as an opaque frontage.

Different approaches are known from the prior art how spandrels made from glass can be designed to achieve this objective. One possibility is to combine glass panes used for the window glass in an isolating glass unit with colored glass panes or with glass panes comprising an enamel layer for providing an adapted spandrel. However, this method is complicated, cost intensive and can due to the thickness of the resulting isolating glass unit not be used in all cases.

A simple coloring of the backside of a glass pane is excluded, since color layers are purely absorptive systems for creating color. Therefore, their visual impression differs fundamentally from a modern window, which is typically coated with an interference layer as a solar light protection so that only light of a certain range of wavelength can pass. From the DE 40 03 851 CI and the DE 41 08 616 CI spandrels are known, wherein the transparency of the windowpane is reduced to the desired level by means of a metal coating. However, it is questionable whether spandrels produced in this manner can be trouble-free processed, for example by bending, annealing, laminating etc. without damaging the coating.

A different approach is know from the US 3,951,525. This document discloses a glass spandrel having a transparent reflecting coating and an opaque enamel layer arranged directly thereon. However, it has been found that such a layer system for a spandrel changes its optical properties after some time. This may lead to unde- sired changes in the color of the spandrel so that the homogenous overall impression of a building is lost.

Further, the adhesion between the enamel layer and the reflection layer arranged directly below is not sufficient to withstand the high loads during processing a spandrel. The US 3,951,525 specifically addresses this disadvantage. For improving the adhesion it is suggested to use enamel coatings having a lower thermal coefficient of expansion than the glass substrate, since a durable spandrel could be achieved due to the resulting compression after depositing the enamel layer.

Based on this prior art, it is the problem of the present invention to provide a spandrel, a combination of a spandrel and a window as well as a method for manufacturing a spandrel which overcomes the above discussed disadvantages of the prior art.

3. Summary of the invention

The present invention relates according to a first aspect to a spandrel, in particular for a building, comprising a glass substrate, an interference layer arranged on the glass substrate, an intermediate layer arranged on the interference layer and a ceramic layer arranged on the intermediate layer. The spandrel according to the invention is based on the recognition that a thin intermediate layer which is arranged above the interference layer and below the ceramic layer substantially improves the long-time stability of the optical impression created by the spandrel according to the invention. The intermediate layer avoids or at least reduces the chemical interaction between the interference layer and the ceramic layer, hi particular, the diffusion of oxygen ions from the ceramic layer into the interference layer is hindered during tempering a spandrel according to the invention. Thus, changes of the optical properties of the thin interference layer due to the aggressive oxygen ions are reduced. Furthermore, the intermediate layer has a compensating influence on the different thermal coefficients of expansion of the layer system. Finally, the intermediate layer improves the mechanical-chemical adhesion between the smooth metal surface of the interference layer on the one hand and the SiO -rich ceramic layer on the other hand.

Preferably, the intermediate layer has an index of refraction similar to the ceramic layer. The optical properties of the spandrel are therefore not influenced by the intermediate layer and are only determined by the interference layer and the ceramic layer.

The intermediate layer comprises preferably one of the following substances or a mixture thereof:

Silicon oxide, silicon nitride, silicon-oxy-nitride, preferably with a thickness of 2 - 20 nrn, more preferably 2 - 10 run and most preferably 3 - 8 nm. The interference layer comprises preferably TiO₂ and a subsequent metal layer, wherein the TiO₂- layer has preferably a thickness of 2 - 20 nm.

According to a further aspect, the present invention relates to a combination of a windowpane and a spandrel as discussed above, wherein the interference layer and/or the ceramic layer are selected such that the wiiidowpane and the spandrel provide a mutually adapted color and/or light reflection.

Finally, the present invention relates to a method for manufacturing a spandrel, comprising the steps of providing a glass substrate, depositing an interference layer, depositing an intermediate layer and depositing a ceramic layer.

According to a first preferred embodiment the interference layer and/or the intermediate layer are deposited by magnetron-cathode sputtering.

According to a further embodiment the intermediate layer is pyrolytically deposited. Mixed techniques, however are also conceivable, wherein a part of the layer system is deposited by a magnetron-cathode sputtering whereas another part is deposited by different methods, for examples pyrolytically. The ceramic layer is preferably deposited by roll coating or by screen printing.

Further improvements of the spandrel according to the invention, the combination of a spandrel and a window and the method according to the invention are the subject matter of further dependent claims.

4. Short description of the drawings

In the following detailed description, presently preferred embodiments of the present invention are described with reference to the drawings which show:

Fig. 1 : A cross-section of a spandrel according to a first embodiment of the present invention; and

Fig. 2: A cross-section through a spandrel according to a second embodiment of the present invention. 5. Detailed description of preferred embodiments

In the following preferred embodiments of the present invention are described with reference to a spandrel for a building. However, it is to be understood that the spandrels according to the invention can also be used in different fields for the visual design of a surface, for example in ship building or in the construction of vehicles.

As shown in Fig. 1, a stack of several layers is arranged on a glass pane 1 for providing a spandrel according to a first embodiment of the present invention. Fig. 1 as well as Fig. 2 are only schematical drawings. The thicknesses of the layers shown are not to scale. The glass pane 1 is preferably a float glass, for example a clear soda-silica glass having a typical thickness of 6 mm, which can be further processed after coating, for example by pretensioning.

Other substrates, which are substantially transparent for visible light, for example other kinds of glasses or suitable plastic materials, are also conceivable.

At first, an interference layer is deposited on the glass substrate 1, preferably by magnetron-cathode sputtering. This method allows to efficiently coat great amounts of windowpanes. The interference layer comprises in the first embodiment of Fig. 1 a TiO -layer 2, being preferably 8 nm thick, followed by a metal layer 3 being in the layer system of Fig. 1 provided as a Ti-layer 3 having a thickness of 3 nm.

Further, also the use of different metals is conceivable, for example silver or aluminum as well as the use of different metal oxides such as SnO₂. Furthermore, the interference layer may also consist of a sequence of several metal layers and dielectric layers. The exact composition of the interference layer depends preferably on the windowpane used together with the discussed spandrel so that once the coating is finished an adapted, i.e. substantially identical reflection impression of the window and the spandrel is obtained. This can for example be determined by comparing with the naked eye the color of the reflection of the sky - blue or if clouds are present gray - on the windowpane and the corresponding spandrel.

As can be further seen from Fig. 1, an intermediate layer 4a is arranged on the interference layer 2, 3. In general, all materials can be considered for the intermediate layer 4a, which avoid that the interference layer 2, 3 is attacked by a chemical interaction with other layers and which do not negatively affect the optical properties of the spandrel in the meaning of the above mentioned adaptation to the visual impression of a corresponding window. To this end, in particular the index of refraction of the intermediate layer should be similar to the index of refraction of the ceramic layer.

In the embodiment of Fig. 1, an intermediate layer of 5 nm SiOo,₅Nι is used. Other materials for the intermediate layer comprise silicon oxide (SiO_x) and silicon-oxy- nitride. Fig. 2 shows for example an embodiment having an 8 nm thick intermediate layer 4b out of Si N₃ arranged on an interference layer of 10 nm TiO₂ and 2,5 nm Ti.

The intermediate layer may be deposited as well as the interference layer by reactive sputtering using a magnetron or by a flame pyrolytic deposition on the interference layer. In the latter method the pane to be coated is moved with a small distance, for example 40 mm, past a burner burning a mixture of air and an additive. For example a mixture of air and silane allows to deposit an SiO_x-layer on the substrate.

The composition of the intermediate layer may vary over a certain range and deviate from an exact stoichiometric ratio for the above mentioned compounds. Further, the use of mixtures of the mentioned materials is also conceivable.

Finally, the enamel coating 5 is deposited. The enamel is a standard enamel and is burnt in at approximately 600°C in a oven passed by the glass pane. Also this pro- cess may be effectively used for large amounts of panes. The thickness of the enamel layer 5 determines, whether the spandrel is completely opaque or whether it is partly transparent for visible light. This allows to obtain different optical impressions depending on the use of the spandrel.

For the further discussion of the invention, further embodiments of the invention are described in the following which are modifications of the layer systems illustrated in Figs. 1 and 2:

An interference layer system comprising 20 nm TiO₂ and 8 nm titanium is arranged by means of large area magnetron deposition onto a clear, soda-silicate glass substrate with a thickness of 6 mm using a deposition apparatus HKZ - A 3210 Z5H 26. An intermediate layer comprising 10 nm Si₂N₃ is deposited thereon using also large area magnetron deposition with a deposition apparatus HKZ -A 3210 Z5H 26. For enameling FE RO, MAGMALOR GmbH Cerdexpress-glass colour, lead free, pasted, FERNBLAU 80, 1022, code X124002A2 is used. This is a ceramic frit based on SiO₂ with several additives which is deposited by a spray method. Subsequently, the spandrel is subjected to a tempering process in a UNI- CHARGE-ESG-oven.

In a further embodiment an interference layer system comprises 8 nm TiO and 4 nm titanium is arranged by means of large area magnetron deposition onto a clear, soda-silicate glass substrate with a thickness of 8 mm using a deposition apparatus HKZ - A 3210 Z5H 26. In this example, the layer for improving adhesion comprises 8 nm silicon oxy-nitride which is also deposited by means of large area magnetron deposition with a deposition apparatus HKZ - A 3210 Z5H 26. The enameling is in this embodiment performed using FERRO, MAGMALOR GmbH Cerdexpress, glass colour, lead free, pasted, BLAUGRAU, RAL 7031. This is a ceramic frit based on SiO₂ with several additives which is deposited by roll coating. Subsequently, the complete spandrel is tempered in a UNI- CHARGE-ESG-oven. In a still further embodiment, an interference layer system comprising 15 nm Ti0₂ and 2 nm titanium is deposited by means of large area magnetron deposition onto a green soda-silicate-glass substrate with a thickness of 10 mm using a deposition apparatus HKZ - A 3210 Z5H 26. A layer for improving adhesion comprising 4 nm silicon oxy-nitride which is also arranged by means of magnetron-large area deposition is arranged thereon. The enameling is performed with FERRO, MAGMALOR GmbH Cerdexpress-glass colour, lead free, pasted, ZELTGRAU RAL 7010. This is again a ceramic frit based on SiO₂ with several additives. The enameling is deposited by means of roll coating. Finally, the overall spandrel is tempered in a UNI-CHARGE-ESG-oven.

According to a still further example, an interference layer system comprising 10 nm TiO and 2 nm titanium is deposited by means of large area magnetron deposition onto a clear soda-silicate glass substrate with a thickness of 50 mm using an apparatus HKZ - A 3210 Z5H 26. In this example, the layer for improving adhesion comprises 3 nm silicon oxy-nitride, which is also deposited by large area magnetron deposition in a deposition apparatus HKZ - A 3210 Z5H 26. The enameling is in this example performed with FERRO, MAGMALOR GmbH Cerdexpress-glass colour, lead free, adapted, SCHWARZGRAU, RAL 7021. Also this enamel is a ceramic frit on the basis of SiO₂ including several additives which are deposited by means of screen printing methods. Finally, the overall spandrel is tempered in a UNI-CHARGE-ESG-oven.

Claims

1. Spandrel, in particular for a building, comprising:

a. a glass substrate (1); b. an interference layer (2, 3) arranged on the glass substrate (1); c. an intermediate layer (4a, 4b) arranged on the interference layer (2, 3); and d. a ceramic layer (5) arranged on the intermediate layer (4a, 4b).

2. Spandrel according to claim 1, wherein the intermediate layer (4a, 4b) has an index of refraction similar to the ceramic layer (5).

3. Spandrel according to claim 1 or 2, wherein the intermediate layer (4a, 4b) comprises at least one of the following materials or a mixture thereof: Silicon oxide (SiO_x), silicon nitride, silicon-oxy-nitride.

4. Spandrel according to claim 3, wherein the intermediate layer (4a) comprises SiOcsN..

5. Spandrel according to claim 3, wherein the intermediate layer (4b) comprises

Si₂N₃.

6. Spandrel according to any of the preceding claims, wherein the intermediate layer (4a, 4b) has a thickness of 2 - 20 nm, preferably 2 - 10 nm and most preferably 3 - 8 nm.

7. Spandrel according to any of the preceding claims, wherein the interference layer comprises a layer (2) TiO₂ and a subsequent metal layer (3).

8. Spandrel according to claim 7, wherein the interference layer comprises a layer TiO₂ of a thickness of 2 - 20 nm.

9. Spandrel according to any of the preceding claims, wherein the ceramic layer (5) has a sufficient thickness to be substantially opaque.

10. Spandrel according to any of the preceding claims, wherein the interference layer (2, 3) the intermediate layer (4a, 4b) and the ceramic layer (5) are arranged on the side of the glass substrate (1) directed to the building.

11. Combination of a window and a spandrel according to any of the claims 1 - 10, wherein the interference layer (2, 3) and/or the ceramic layer (5) are selected such that the window and the spandrel provide a mutually adapted color and/or light reflection impression.

12. Combination according to claim 11, wherein the windowpane is a pretension- able float glass pane coated by a magnetron.

13. Method for the manufacture of a spandrel comprising the following steps:

a. Providing a glass substrate (1); b. Depositing an interference layer (2, 3); c. Depositing an intermediate layer (4a, 4b); and d. Depositing a ceramic layer (5).

14. Method according to claim 13, wherein the interference layer (2, 3) and or the intermediate layer (4a, 4b) are deposited by magnetron-cathode sputtering.

15. Method according to claim 13, wherein the intermediate layer (4a, 4b) is pyrolytically deposited.

16. Method according to any of the claims 13 - 15, wherein the ceramic layer (5) is deposited by means of roll coating or screen printing.

17. Method according to any of the claims 13 - 16 for manufacturing a spandrel according to any of the claims 1 - 9.