Multiple glazing with integrated curtain blocking visible light and allowing near-infrared light to pass through

Abstract

Multiple glazing (1) comprising a first glazing unit (2) and a second glazing unit (3) held apart by a peripheral seal (4) so ​​as to define a closed cavity (5), which contains a curtain (6) capable of being deployed opposite all or part (8) of the surface of the multiple glazing unit (1), the curtain (6) being constructed, over part or all of its surface, such that the part of the surface of the multiple glazing unit (1) opposite it constitutes a zone (7) relatively opaque to visible light (average absorption of 20 to 97% and average light transmission of 0 to 70% between 380 and 780 nm) and relatively transparent to near-infrared light (average absorption of at most 30% and average light transmission of at least 60% between 780 and 2500 nm). Figure for the abstract: Figure 2

Description

Title of the invention: Multi-glazed unit with integrated curtain blocking visible light and allowing near-infrared light to pass through

[0001] The invention relates to multiple glazing units, designating several panes of glass held together and separated from one another by a peripheral seal or spacer defining a closed cavity between two adjacent panes. Double glazing comprises one cavity, triple glazing comprises two cavities... A cavity consists of a layer of air containing desiccants, or of a layer of gas such as argon, krypton... The cavity may alternatively be under a certain vacuum, at a pressure lower than atmospheric, in particular to increase the thermal insulation capacity of the multiple glazing unit.Each pane of glass in a multiple glazing unit may be monolithic, made of mineral glass of soda-lime silicate composition, aluminosilicate, borosilicate or equivalent, possibly thermally tempered or chemically strengthened, or of transparent polymer material such as poly(methyl methacrylate) (PMMA), polycarbonate (PC) or equivalent, or laminated, in which case it consists of several transparent sheets of the aforementioned nature, bonded two by two by an interlayer adhesive layer of the type polyvinyl butyral (PVB), polyurethane (PU), ethylene-vinyl acetate copolymer (EVA), transparent casting resin, ionomer resin or equivalent.

[0002] The invention was intended to provide two main functions to the multiple glazing.

[0003] The primary aim was to ensure visual comfort, firstly by reducing glare inside a building or vehicle such as an automobile, particularly when the sun is low in the sky, as in regions far from the equator, and secondly by hiding elements on the other side of the multiple glazing, for example an infrared presence sensor, a device for detecting and estimating distance by light or by laser (in English LIDAR for "light detection and ranging"), to measure distances and / or image, a camera filming the face of the driver of an automobile to react to risky driving (drowsiness, stress...), which must be masked as much as possible so that the driver does not feel too observed, any technological device allowing connected objects to communicate with each other, generally wirelessly (in English IoT for "Internet of Things").

[0004] Secondly, it was investigated that the multiple glazing, in addition to ensuring visual comfort as just defined, allows near-infrared radiation to pass through, in the first situation described above, so that a maximum fraction of solar energy enters the interior of a building or vehicle such as a car, to heat it particularly in polar regions, Scandinavia (high value of the total solar energy transmission factor, solar factor g defined by the EN 410:2011 standard), and in the second situation described above, allows optimal operation of all types of infrared sensors mentioned above.

[0005] This objective has been achieved by the invention, which consequently relates to a multiple glazing unit comprising at least a first glazing unit and a second glazing unit held apart from each other by a peripheral seal so as to delimit a closed cavity, which contains a curtain adapted to be deployed opposite all or part of the surface of the multiple glazing unit, characterized in that the curtain is constituted, over part or all of its surface, such that the part of the surface of the multiple glazing unit opposite this part or the entire surface of the curtain constitutes a zone of relative opacity to visible light and relative transparency to near-infrared light, and exhibits an average absorption of 20 to 97% and an average light transmission of 0 to 70% at wavelengths from 380 to 780 nm and an average absorption of at most 30% and an average light transmission of at least 60% at wavelengths from 780 to 2500 nm.According to the invention, the average absorption and average light transmission values ​​are determined according to standard EN410:2011.

[0006] Thus, the curtain makes it possible, in particular, on a controlled portion of the multi-glazed surface, for the average light transmission to be more or less substantially lower between 380 and 780 nm than between 780 and 2500 nm. Glare from grazing sunlight is limited, and the visibility of an infrared sensor through the multi-glazed unit is sufficiently reduced to no longer cause discomfort. Solar energy passes through the multi-glazed unit in an increased proportion, allowing the building and the interior to be heated, and the operation of an infrared sensor is guaranteed.

[0007] Preferably, the curtain, in the part or all of its surface intended to be opposite the area of ​​relative opacity to visible light and relative transparency to near-infrareds of the surface of the multiple glazing, has a uniform constitution in its thickness, or includes a substrate which supports a coating or a film, so that the curtain provides the area of ​​relative opacity to visible light and relative transparency to near-infrareds of the surface of the multiple glazing with the required properties of average absorption and average light transmission.

[0008] In particular, when the substrate supports a coating or film, it can be transparent to visible and near-infrared light.

[0009] Preferably, the curtain is a roller blind, or a pleated blind, or a Venetian blind, each of which is capable of being deployed over all or part of the surface of the multiple glazing, including an upper or lower part, or a central part of this surface.

[0010] Preferably, the curtain is constructed, at least on a lower portion in the mounting position within the multiple glazing, such that the portion of the multiple glazing surface opposite this lower portion of the curtain surface constitutes a zone of relative opacity to visible light and relative transparency to near-infrared light. Advantageously, this zone is also a lower portion of the multiple glazing surface: this configuration is suitable for blocking grazing sunlight, while allowing an upper portion of the curtain and the multiple glazing surface to remain free from the visible light-blocking function. Thus, natural lighting of the upper part of the enclosure, building ceiling, cabin roof, or vehicle interior can be obtained (this function is known as "daylighting").When the curtain is a Venetian blind, it is possible to angle the slats of the blind so that the sunlight is reflected upwards.

[0011] In an advantageous embodiment, the curtain, in the part or all of its surface intended to be opposite the area of ​​relative opacity to visible light and relative transparency to near-infrareds of the surface of the multiple glazing, comprises Sudan Black B, Nigrosine or other equivalent colorant or pigment, in its constitution, possibly in the constitution of its substrate and / or its coating and / or its film.

[0012] Sudan Black B has a high visible light absorption value (380–780 nm) and a very low absorption value for wavelengths above 780 nm. Thus, a 20 µm thick polyacrylate coating containing 0.5 wt% of Sudan Black B absorbs on average more than 75% of visible light up to wavelengths of 700 nm, and less than 5% of electromagnetic radiation at wavelengths between 800 and 2200 nm. Sudan Black B has a particularly neutral color (gray / black appearance). Due to a certain hydrophobicity, the molecules of Sudan Black B are soluble in various matrices, particularly polymers, for coloring plastic components. Sudan Black B has the following structural formula.

[0013] [Chem.l]

[0014] Nigrosine with properties equivalent to those of Sudan Black B is the trade name of a family of mixtures of organic bluish-black aniline-based dyes, soluble in fats, also sold in a water-soluble sulfonated form.

[0015] 3M also markets a film under the name Sensor Camouflage film (SCF), which blocks visible light (by absorption and / or reflection), while remaining transparent to infrared, allowing different types of IR sensors to be hidden; in particular the driver monitoring system (LoT) mentioned above.

[0016] Preferably, the first pane of glass is intended to be in contact with the outside atmosphere, and the face of the second pane of glass facing the first pane supports a low-emissivity stack. This technical measure has the effect of retaining heat inside the enclosure.

[0017] The invention will be better understood in the examples below with reference to the accompanying drawings in which

[0018] [Fig. 1] is a schematic representation of a first multiple glazing according to the invention, in the fully deployed position of the curtain;

[0019] [Fig.2] is a schematic representation of a second multiple glazing according to the invention, in an intermediate position of the curtain; and

[0020] [Fig.3] is a schematic representation of a third multiple glazing according to the invention, in the fully deployed position of the curtain.

[0021] With reference to [Fig. 1], the double glazing 1 consists of a first 2 and a second 3 monolithic panes of glass, such as soda-lime glass, fixed to each other with a gap between them by a gasket or spacer 4. The cavity 5, delimited by the panes 2 and 3 and the gasket 4, is closed and consists of an air gap containing a desiccant (not shown). The cavity 5 contains a curtain 6 that unwinds from a roller 10 positioned at the top of the cavity 5 in the operating position, and consequently unwinds from top to bottom, by means of a control (not shown) external to the double glazing 1. The roller system 10 could be replaced by a pleated curtain that also unfolds from top to bottom by means of wires or cables, without departing from the scope of the invention.

[0022] The curtain 6, in its fully deployed position, is opposite almost the entire surface 8 of the double glazing 1. The entire surface of the curtain 6 is functionalized here with a material that is opaque to visible light but largely transparent to near-infrared light. In other words, the area 7 of relative opacity to visible light and relative transparency to near-infrared light coincides with almost the entire surface 8 of the double glazing 1.

[0023] The curtain 6 consists of a substrate made of a flexible polymer material transparent to visible and near-infrared light. The functionalization of the curtain 6 is obtained by the fact that it is made of a film marketed by the Saint-Gobain Company under the brand name SolarGard® (trade name series NRSupreme). This series of films offers various colors, with average light transmissions varying, depending on the color of the film, from approximately 30 to 70% between 380 and 700 nm, and all greater than 70% for wavelengths from 780 to 2500 nm.

[0024] The face of the second glazing 3 oriented towards the first 2 supports a low-emissivity stack marketed by the Société Saint-Gobain under the brand Eclaz® Lumi; it has the effect of reflecting part of the heat of the enclosure while maintaining high light transmission over the entire solar spectrum.

[0025] The double glazing 1 of [Fig. 2] differs from that of [Fig. 1] only in that the curtain 6 is made of the same functional film only in its lower portion. As shown in [Fig. 1], the curtain can be lowered to the bottom of the surface of the double glazing 1. In this case, the area 7 of relative opacity to visible light and relative transparency to near-infrared light represents only the corresponding lower portion of the surface of the double glazing 1. The curtain 6 is made in its upper portion of a flexible material, in particular a polymer, transparent to visible light and near-infrared light. Thus, the upper portion of the surface of the double glazing 1, opposite the non-functional upper portion of the curtain 6, is transparent to both visible and near-infrared light. This allows natural light to reach the top of the enclosure (referred to in English as "daylighting").

[0026] The double glazing 1 of [Fig.3] differs from that of [Fig.1] only in that the curtain 6 is here a Venetian blind, with adjustable slats in the blackout position (same function as the curtain 6 of [Fig.1]), or possibly in the horizontal position allowing the light to be reflected towards the top of the enclosure.

Claims

Demands

1. Multiple glazing (1) comprising at least a first glazing unit (2) and a second glazing unit (3) held apart from each other by a peripheral seal (4) so ​​as to define a closed cavity (5), which contains a curtain (6) capable of being deployed opposite all or part (8) of the surface of the multiple glazing unit (1), characterized in that the curtain (6) is constituted, over part or all of its surface, such that the part of the surface of the multiple glazing unit (1) opposite this part or all of the surface of the curtain (6), constitutes a zone (7) of relative opacity to visible light and relative transparency to near-infrared light, and has an average absorption of 20 to 97% and an average light transmission of 0 to 70% at wavelengths from 380 to 780 nm and an average absorption of at most 30% and an average light transmission of at least 60% at wavelengths from 780 to 2500 nm.

2. Multiple glazing (1) according to claim 1, characterized in that the curtain (6), in the part or all of its surface intended to be opposite the zone (7) of relative opacity to visible light and relative transparency to near-infrareds of the surface of the multiple glazing (1), has a uniform constitution in its thickness, or comprises a substrate which supports a coating or a film, so that the curtain (6) provides the zone (7) of relative opacity to visible light and relative transparency to near-infrareds of the surface of the multiple glazing (1) with the required properties of average absorption and average light transmission.

3. Multiple glazing according to claim 2, characterized in that the substrate which supports a coating or film is transparent to visible and near-infrared light.

4. Multiple glazing (1) according to claim 1, characterized in that the curtain (6) is a roller blind, or a pleated blind, or a Venetian blind, each being able to be deployed over all or part (8) of the surface of the multiple glazing (1), in particular an upper or lower part, or a central part of this surface.

5. Multiple glazing (1) according to any one of the preceding claims, characterized in that the curtain (6) is constituted, on at least a lower part in the mounting position in the multiple glazing (1), such that the part of the surface of the multiple glazing (1) opposite this lower part of the surface of the curtain (6), constitutes a zone (7) of relative opacity to visible light and of relative transparency to near-infrared light.

6. Multiple glazing (1) according to claim 5, characterized in that the zone (7) of relative opacity to visible light and of relative transparency to near-infrared is a lower part of the surface of the multiple glazing (1).

7. Multiple glazing according to claim 2, characterized in that the curtain (6), in the part or all of its surface intended to be opposite the area (7) of relative opacity to visible light and relative transparency to near-infrared of the surface of the multiple glazing (1), comprises Sudan Black B, Nigrosine or other equivalent dye or pigment, in its constitution, optionally in the constitution of its substrate and / or its coating and / or its film.

8. Multiple glazing (1) according to any one of the preceding claims, characterized in that the first glazing (2) is intended to be in contact with the outside atmosphere, and in that the face of the second glazing (3) oriented towards the first glazing (2) supports a low-emissivity stack (9).

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