DE202021100462U1 - Vehicle window - Google Patents

Abstract

Vehicle window, comprising an outer window (1) with an outside surface (I) and an inside surface (II), an inside window (2) with an outside surface (III) and an inside surface (IV) and a space (3) which between the interior surface (II) of the outer pane (1) and the outer surface (III) of the inner pane (2).

Description

The invention relates to a vehicle window, in particular a vehicle window as a roof window of a motor vehicle.

In particular in the case of large-area vehicle windows, the thermal comfort of vehicle occupants due to solar radiation on the one hand and cooling of the vehicle via the glass surface on the other hand must be avoided. For this purpose, coatings are usually used that improve thermal comfort.

The DE 19927683 C1 discloses a laminated glass pane made of at least two glass panes and a transparent laminated layer connecting them and with a sun protection layer which essentially reflects rays outside the visible spectrum of solar radiation, in particular infrared rays, characterized in that the laminated glass pane has a further surface on its surface facing an interior space the sun protection layer is provided with a spatially separated, transparent, essentially heat radiation reflective coating (low-E layer). Task of DE 19927683 C1 is to provide a laminated glass pane with sun protection properties, in which, at low outside temperatures, the heat absorption is greatly reduced by large-area glazing from the vehicle interior. The light transmission through the composite pane is 31%, for example.

Glazing such as those used in sunroofs and sliding roofs require a light transmission between 2 and 10% and specific sun protection, characterized by the TTS value, which is a measure of the total heat radiation transmitted by the sun through the pane and, for example, in accordance with ISO 9050 is measured. With a higher light transmission, on the one hand, too much thermal radiation is transmitted and, on the other hand, the people behind the glazing can be visually disturbed by too much light entering. With a lower light transmission, the glazing is overall too dark so that people behind the glazing can no longer see through it.

The goal is therefore the lowest possible TTS value in combination with a light transmission of 2 to 10% in order to ensure the best possible compromise between the view to the outside through the roof and good thermal properties. Therefore, a low level of radiation and IR-reflecting, i.e., functions that control solar radiation, must be combined in sunroofs and sunroofs. IR-reflecting functions, i.e. functions that control solar radiation, are achieved by means of silver-based coatings on the inside of the outer pane or a polyethylene terephthalate film between two polyvinyl butyral films. In addition, dark tinted polyvinyl butyral films can be used between the sun-controlling coating and the inner pane.

WO 2013/127563 A1 discloses a further laminated pane with a sun protection layer between the glass panes and a low-E coating on the surface on the interior side. The Low-E coating is based on niobium, tantalum, molybdenum or zirconium.

Out WO 2019/110172 A1 For example, glass laminates are known that have an infrared-reflecting layer on the inside of the outer pane (page 2 ) and a LowE coating on the inside of the inner pane (side 4th ) exhibit.

In CN 102536061 A a glazing comprising an airgel and a LowE coating is disclosed.

The invention is based on the object of providing a vehicle window which has further improved sun protection and good thermal insulation properties.

According to the invention, this object is achieved by a vehicle window according to claim 1. The vehicle window according to the invention comprises an outer pane with an outside surface and an interior-side surface, an inner pane with an outside surface and an interior-side surface, there being a gap between the interior-side surface of the outer pane and the outside surface of the inner pane.

In a first preferred embodiment, an airgel is introduced into the space between the interior surface of the outer pane and the outer surface of the inner pane. The airgel can be transparent, milky or tinted.

In a second preferred embodiment, a gas is introduced into the space between the inner surface of the outer pane and the outer surface of the inner pane, for example an inert gas such as nitrogen or noble gases such as krypton or argon, or there is a vacuum in the space. According to this second embodiment, the vehicle window is an insulating glazing.

The vehicle window according to the invention has in comparison to a laminated Laminated pane has a lower heat transfer coefficient, also known as the U-value. This is further improved by filling the space with airgel, a gas or a vacuum.

In order to further increase the thermal comfort in the vehicle interior, it is desirable to improve the thermal insulation and to ensure that the vehicle does not heat up as a result of solar radiation.

Sun protection coatings known to the person skilled in the art reflect infrared radiation almost completely, but also have a high reflectivity in the range of visible light. At the same time, these sun protection coatings have a LowE property, which, however, is not used in the composite windows often used in the automotive sector. The panes of a composite pane are connected to one another via a thermoplastic composite film, usually polyvinyl butyral. The heat transfer through such a pane takes place primarily via heat conduction via the thermoplastic composite film. This heat conduction can be prevented by using a vehicle window with a gap. In particular, if the space is filled with a gas or has a vacuum, the conduction of heat is minimized. The controlled atmosphere that is created in the space and prevents corrosion of the sun protection coating is also advantageous. Oxygen and moisture are known to promote corrosion of coatings, making the use of silver-based coatings on a surface exposed to the atmosphere difficult or impossible. This problem is avoided by using a sun protection coating in the gap. If the gap is filled with an airgel that is in contact with the sun protection coating, the LowE effect remains in the surface areas where air is present.

The vehicle window preferably has at least one sun protection coating between the outer window and the inner window, which essentially reflects or absorbs rays outside the visible spectrum of solar radiation, in particular infrared rays.

The vehicle window preferably has a coating that reflects heat rays, also referred to as a low-E coating, on the surface of the inner window on the interior side.

The vehicle window is intended to separate the interior of a vehicle from the external environment in a window opening. The vehicle window comprises a first and a second glass pane, which in the context of the invention are referred to as an outer pane and an inner pane. In the context of the invention, the inner pane is the pane facing the interior space in the installed position. Outer pane is the term used to describe the pane facing the external environment in the installed position. In the context of the invention, the surface on the interior side (or inside or inside surface) is understood to mean that surface of the panes which, in the installed position, faces the interior. In the context of the invention, the outside surface (or outside or outside surface) is understood to mean that surface of the panes which, in the installed position, faces the external environment.

The surfaces of the glass panes are typically referred to as follows: The outside of the outer pane is called the side 1 designated. The inside of the outside pane is called the side 2 designated. The outside of the inside pane is called the side 3 designated. The inside of the inner pane is called the side 4th designated.

The interior-side surface of the outer pane and the outer-side surface of the inner pane face one another, with the space between them.

The sun protection coating (or sun protection layer) is preferably arranged between the outer pane and the inner pane. In a preferred embodiment, the sun protection coating is applied to the surface of the outer pane on the inside. In a further embodiment, the sun protection coating is applied to the outside surface of the inner pane.

The sun protection coating has the task of filtering out portions of solar radiation, especially in the infrared range. The sun protection coating preferably comprises at least one thin transparent metallic layer which is embedded between at least one dielectric layer. Silver has established itself as the preferred metal for the metallic layer, since it has a relatively neutral color effect and also selectively reflects infrared radiation outside the visible range of solar radiation. The dielectric layers have the task of improving the optical properties of the coated pane via their refractive indices and of protecting the metallic functional layer from oxidation. Such sun protection layers, which can be produced, for example, using the reactive sputtering method, are used to a large extent in glazing for buildings, but also in motor vehicles. In most cases, layer systems with two silver functional layers, but also three or four silver functional layers, are used because their efficiency, ie the The reflection of the infrared radiation outside the visible range in relation to the transmission of the visible radiation is greater.

Suitable sun protection coatings are, for example, from WO2013 / 104439A1 as well as the DE 19927683C1 known.

The dielectric layers are preferably formed on the basis of dielectric oxides or nitrides, such as ZnO, SnZnO, AlN, SiO ₂ , TiO ₂ or Si ₃ N ₄ .

As an alternative to the inorganic, in particular silver-based coatings, the sun protection coating can also be formed on a non-metallic, organic basis. In this case, the sun protection coating is preferably a stack of several, typically several hundreds, organic layers with different or alternating refractive indices. The stack is a birefringent dielectric interference stack that reflects IR radiation due to interference effects. Such organic coatings have the advantage over metallic coatings of higher color neutrality and higher light transmission. In addition, they do not interfere with the transmission of electromagnetic signals.

Preference is given to the inside of the inner pane (page 4th ) a coating that reflects the heat rays is applied. Such coatings are, for example, from WO2013 / 131667A1 known. The coating that reflects heat rays can also be referred to as a coating of low emissivity, an emissivity-reducing coating, a low-E coating or a low-E layer. It has the task of reflecting thermal radiation, i.e. in particular IR radiation that has a longer wavelength than the IR component of solar radiation. At low outside temperatures, the Low-E coating reflects heat back into the interior and reduces the cooling of the interior. At high outside temperatures, the Low-E coating reflects the thermal radiation of the heated pane to the outside and reduces the heating of the interior. On the inside of the inner pane, the coating according to the invention particularly effectively reduces the emission of heat radiation from the pane into the interior in summer and the emission of heat into the outside environment in winter.

The coating that reflects heat rays preferably comprises a functional layer which contains a transparent conductive oxide (TCO), preferably indium tin oxide, tin oxide doped with antimony or fluorine and / or zinc oxide doped with gallium and / or aluminum (ZnO: Ga, or ZnO: AI), indium tin oxide being preferred. The functional layer can also contain other electrically conductive oxides, for example fluorine-doped tin oxide (SnO ₂ : F), antimony-doped tin oxide (SnO ₂ : Sb), indium-zinc mixed oxide (IZO), or gallium-doped Aluminum-doped zinc oxide, niobium-doped titanium oxide, cadmium stannate and / or zinc stannate. This achieves particularly good results with regard to the emissivity and the flexibility of the coating according to the invention. The refractive index of the material of the functional layer is preferably 1.7 to 2.5.

The indium tin oxide is preferably deposited by means of magnetic field-assisted cathode sputtering with a target made of indium tin oxide. The target preferably contains from 75% by weight to 95% by weight indium oxide and from 5% by weight to 25% by weight tin oxide as well as production-related additions. The tin-doped indium oxide is preferably deposited under a protective gas atmosphere, for example argon. A small proportion of oxygen can also be added to the protective gas, for example in order to improve the homogeneity of the functional layer.

Alternatively, the target may preferably contain at least from 75 wt% to 95 wt% indium and from 5 wt% to 25 wt% tin. The deposition of the indium tin oxide then preferably takes place with the addition of oxygen as the reaction gas during the cathode sputtering.

The coating that reflects heat rays also typically comprises dielectric layers, in particular formed from dielectric oxides or nitrides, such as ZnO, SnZnO, AlN, TiO ₂ , SiO ₂ or Si ₃ N ₄ . The layer of reflective conductive oxide is anti-reflective by using additional dielectric layers above and below in order to ensure a sufficiently low reflection from the inside.

The emissivity of the pane according to the invention can be influenced by the thickness of the functional layer of the coating that reflects heat rays. The thickness of the functional layer is preferably 40 nm to 200 nm, particularly preferably 60 nm to 150 nm and very particularly preferably 65 nm to 85 nm, for example about 75 nm advantageous ability of the coating reflecting the heat rays to withstand a mechanical transformation such as bending or prestressing without damage.

The interior emissivity of the pane according to the invention is preferably less than or equal to 50%, particularly preferably from 10% to 50%, very particularly preferably from 20% to 35%. With emissivity on the inside, the measure becomes denotes, which indicates how much heat radiation the pane emits in the installed position compared to an ideal heat radiator (a black body) in an interior, for example a building or a vehicle. In the context of the invention, emissivity is understood to mean the normal emissivity at 283 K according to the EN 12898 standard.

The use of airgel in the space or the execution as insulating glazing enables the use of coatings, such as sun protection coatings, on the sides 2 and 3 . In this way, particularly effective sun protection can be achieved. The best result can be achieved if there is also a LowE coating on the side 4th is attached.

The vehicle window can optionally be tinted. This is particularly the case with vehicle roof glazing or other vehicle glazing for which limit values for light transmission are not prescribed by law. A dark tint of the outer glass increases the absorption, as a result of which the outer glass heats up and this heat is given off again through re-emission and wind convection.

When the sun protection coating on side 2 is attached, incident radiation is reflected on it and absorbed once more by the outer pane before it emerges from the glazing. Accordingly, the following options are preferably used to obtain tinted glazing: use of a tinted coating, use of a tinted airgel and / or use of a tinted inner glass. Alternatively or additionally, a tinted thermoplastic composite film, for example a PVB film, can also be incorporated into the structure, with the LowE effect of an adjacent sun protection coating being lost on the surface on which the PVB film rests.

The outer pane and the inner pane are preferably formed independently of one another from glass or plastic, preferably soda-lime glass, alkali aluminosilicate glass, polycarbonate or polymethacrylate. In a particularly preferred embodiment, the outer pane and the inner pane are made of glass.

Suitable panes of glass include panes of glass known under the trade names VG10, VG20, VG40 or TSANx, TSA3 +, TSA4 + from Saint-Gobain, the glasses of the VG series being gray-colored glasses and those of the TSA series being green-colored glasses acts.

The outer and / or inner pane preferably has a thickness of 0.1 to 4 mm, preferably 1 to 4 mm, particularly preferably 1.6 mm to approximately 2.1 mm, independently of one another.

The invention is explained in more detail below with reference to a drawing and exemplary embodiments. The drawing is a schematic representation and is not true to scale. The drawing does not restrict the invention in any way.

• 1 einen Querschnitt durch eine Ausgestaltung der erfindungsgemäßen Fahrzeugscheibe,
• 2 einen Querschnitt durch eine weitere Ausgestaltung der erfindungsgemäßen Fahrzeugscheibe,
• 3 einen Querschnitt durch eine weitere Ausgestaltung der erfindungsgemäßen Fahrzeugscheibe.

Show it:

• 1 a cross section through an embodiment of the vehicle window according to the invention,
• 2 a cross section through a further embodiment of the vehicle window according to the invention,
• 3 a cross section through a further embodiment of the vehicle window according to the invention.

1 shows a cross section through an embodiment of the vehicle window according to the invention. The vehicle window includes an outer window 1 and an inner pane 2 between which there is a space 3 is located. The vehicle window has a size of approximately 1 m ² and is provided as a roof pane of a passenger car, the outer pane 1 is intended to face the external environment and the inner pane 2 is intended to face the vehicle interior. The outer pane 1 has an outside surface I and an inside surface II. The inner pane 2 has an outside surface III and an inside surface IV. The outside surfaces I and III face the outside environment in the installed position, and the inside surfaces II and IV face the vehicle interior in the installed position. The interior-side surface II of the outer pane 1 and the outside surface III of the inner pane 2 are facing each other. The outer pane 1 and the inner pane 2 contain soda-lime glass and are each 2.1 mm thick. In the space in between 3 an airgel is introduced. Alternatively, the vehicle window is designed as double glazing and there is a gas or vacuum in the space. In one version as insulating glazing, the panes are 1 , 2 connected to one another in the edge area via a circumferential spacer (not shown).

2 shows a cross section through a further embodiment of the vehicle window according to the invention. The embodiment corresponds essentially to the configuration in FIG 1 , the vehicle window being the 2 in addition one Sun protection coating 4th and a LowE coating 5.

On the interior-side surface II of the outer pane 1 is a sun protection coating 4th arranged. The sun protection coating 4th extends over the entire surface II minus a circumferential, frame-shaped, coating-free area with a width of 8 mm. As in 1 the space in between is described 3 filled with an airgel or, in one embodiment as insulating glazing, filled with gas or vacuum. The sun protection coating 4th is thereby advantageously protected against damage and corrosion. The sun protection coating 4th comprises, for example, at least two functional layers which contain at least silver or consist of silver and have a layer thickness between 10 nm and 20 nm, each functional layer being arranged between two dielectric layers made of silicon nitride with a thickness of 40 nm to 70 nm.

On the interior surface IV of the inner pane 2 a coating 5 that reflects heat rays is arranged. The coating 5 comprises a functional ITO layer with a thickness of 60 nm to 150 nm. The coating 5 also comprises further dielectric layers above and below the functional layer, in particular made of Al-doped SiO ₂ and Si ₃ N ₄ .

The sun protection coating 4th leads to reduced heating of the vehicle interior and the inner window 2 due to the reflection of infrared radiation. The coating 5, which reflects heat rays, on the one hand reduces the radiation of heat radiation through the vehicle window into the vehicle interior, in particular at high outside temperatures. Coating 5 which reflects heat rays, on the other hand, reduces the radiation of heat radiation from the vehicle interior at low outside temperatures.

3 shows a cross section through a further embodiment of the vehicle window according to the invention. The embodiment corresponds essentially to the configuration in FIG 2 , with the difference being the sun protection coating 4th on the outside surface III of the inner pane 2 is arranged.

List of reference symbols

(1)

Outer pane

(2)

Inner pane

(3)

Space

(4)

Sun protection coating

(5)

Coating that reflects heat rays / Low-E coating

(I)

outside surface (outer surface) of ( 1 ), also as a page 1 designated

(II)

interior surface (inner surface) of ( 1 ), also as a page 2 designated

(III)

outside surface (outer surface) of ( 2 ), also as a page 3 designated

(IV)

interior surface (inner surface) of ( 2 ), also as a page 4th designated

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 19927683 C1 [0003, 0023]
• WO 2013/127563 A1 [0006]
• WO 2019/110172 A1 [0007]
• CN 102536061 A [0008]
• WO 2013/104439 A1 [0023]
• WO 2013/131667 A1 [0026]

Claims (6)

Vehicle window, comprising an outer window (1) with an outside surface (I) and an inside surface (II), an inside window (2) with an outside surface (III) and an inside surface (IV) and a space (3) which between the interior surface (II) of the outer pane (1) and the outer surface (III) of the inner pane (2). Vehicle window after Claim 1 , an airgel being introduced into the intermediate space (3). Vehicle window after Claim 1 , wherein a gas is introduced into the intermediate space (3) or a vacuum is present in the intermediate space (3). Vehicle window according to one of the Claims 1 to 3 , wherein the vehicle window between the outer window (1) and the inner window (2) has at least one sun protection coating (4) which essentially reflects or absorbs rays outside the visible spectrum of solar radiation, in particular infrared rays. Vehicle window according to one of the Claims 1 to 4th wherein the vehicle window has a coating (5) that reflects heat rays on the interior surface (IV) of the inner window (2). Vehicle window according to one of the Claims 1 to 5 wherein the vehicle window is a roof window of a motor vehicle.

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