CN121001876A

CN121001876A - Laminated sheets with electro-controllable optical properties

Info

Publication number: CN121001876A
Application number: CN202480027315.7A
Authority: CN
Inventors: B·纳格尔; M·克莱因; R·施特尔泽; T·施米茨
Original assignee: Saint Gobain Safety Glass Co In France
Current assignee: Saint Gobain Safety Glass Co In France
Priority date: 2023-04-26
Filing date: 2024-04-18
Publication date: 2025-11-21
Also published as: KR20250174093A; WO2024223401A1

Abstract

The present invention relates to a laminated sheet (100) having electro-controllable optical properties, the laminated sheet (100) comprising: an outer sheet (1), a thermoplastic intermediate layer (3), an inner sheet (2), and a functional element (4), the functional element (4) being disposed between the outer sheet (1) and the inner sheet (2) and having electro-controllable optical properties, wherein the functional element (4) comprises: an active layer (5) having a first surface (A), a second surface (B), and a peripheral side surface (S); a first planar electrode (6.1) extending on the first surface (A) in a first region (5.1) of the active layer (5); a second planar electrode (6.2) extending on the first surface (A) in a second region (5.2) of the active layer (5); and a third planar electrode (6. 3), which extends on the second surface (B) at least in the first region (5.1) and the second region (5.2) of the active layer (5); and a bridge (7) that electrically connects the first planar electrode (6.1) to the third planar electrode (6.3), wherein the first planar electrode (6.1) has a first protruding region (U') relative to the active layer (5), and the second planar electrode (6.2) has a second protruding region (U'') relative to the active layer (5), and the first busbar (8.1) is arranged at least on the first protruding region (U'), and the second busbar (8.2) is arranged at least on the second protruding region (U''), and wherein the first planar electrode (6.1) and the second planar electrode (6.2) are electrically insulated from each other.

Description

Laminated sheet with electrically controllable optical properties

Technical Field

The present invention relates to a laminate with a functional element, a method for producing the laminate, the use of such a laminate and a vitrification unit with a laminate.

Background

In the vehicle industry and in the construction industry, laminated sheets with electrically controllable functional elements are commonly used for sun protection or privacy protection. For example, windshields are known in which the sun visor is integrated in the form of a functional element having electrically controllable optical properties. In particular, the transmittance or scattering behavior of electromagnetic radiation in the visible range is electrically controllable. The functional element is substantially like a film and is laminated into or glued to the laminate. In the case of windshields, the driver can for example control the transmission behaviour of the sheet itself with respect to solar radiation. Thus eliminating the need for conventional mechanical visors. Thus, the weight of the vehicle can be reduced and space can be obtained in the roof area. In addition, the electrical control of the sun visor is more convenient for the driver than manual folding down of a mechanical sun visor.

Windshields with such electrically controllable sun visors are known, for example, from DE102013001334A1, DE102005049081B3, DE102005007427A1 and DE102007027296 A1.

Typical electrically controllable functional elements include electrochromic layer structures or Single Particle Device (SPD) films. Another possible functional element for achieving electrically controllable sun protection is the so-called PDLC (polymer-dpersed liquid crystal) functional element. Their active layer comprises liquid crystals embedded in a polymer matrix. If no voltage is applied, the liquid crystals align in a disordered manner, which results in strong scattering of light passing through the active layer. If a voltage is applied to the planar electrodes, the liquid crystals are aligned in a common direction, and the transmittance of light passing through the active layer increases. PDLC functions are less active by reducing the total transmission and more active by increasing the scattering in order to ensure antiglare protection. PDLC functions are known, for example, from US20150301367 A1.

Problems with laminated functional elements result from gas ingress and diffusion of plasticizers or other deleterious compounds into the functional elements. Substances often penetrate through the poorly protected side surfaces of the functional element, which often leads to undesirable signs of aging, such as brightening and shading. These problems occur in particular with respect to PDLC functional elements.

JP 2008225399 discloses a liquid crystal display element on a flexible substrate such as a plastic material film, wherein the side surface has a gas barrier layer which prevents gas from entering through the side surface of the substrate. WO2019077014A1 and WO2018188844A1 disclose laminated sheets with functional elements, wherein the functional elements are protected from penetration by plasticizers from thermoplastic interlayers by means of a plurality of barrier layers on the side surfaces.

Disclosure of Invention

The invention is therefore based on the object of providing an improved functional element which has electrically controllable optical properties and good aging resistance and which can be produced cost-effectively.

The object of the invention is achieved by a laminate sheet according to independent claim 1. Preferred embodiments are evident from the dependent claims.

The laminate sheet according to the invention comprises an outer sheet, a thermoplastic intermediate layer, an inner sheet and a functional element arranged between the outer sheet and the inner sheet and having electrically controllable optical properties. The functional element includes an active layer having a first surface, a second surface, and a peripheral side surface, a first planar electrode, a second planar electrode, a third planar electrode, and a bridge conductively connecting the first planar electrode to the third planar electrode. A thermoplastic intermediate layer is disposed between the outer sheet and the inner sheet.

The active layer and the planar electrode are film-shaped and form a stacked sequence. Films typically have a large surface area but only a small total thickness. Hereinafter, the large surfaces of the stacking sequence defining the stacking sequence are referred to as an upper surface and a lower surface, and the surfaces orthogonal thereto and having only a small width (corresponding to the direction of the small total thickness) are referred to as side surfaces. The first and second surfaces of the active layer are arranged parallel to the lower and upper surfaces of the stacking sequence. The side surfaces of the active layer refer only to the side surfaces of the active layer, whereas the term "side surfaces of the functional element" is understood to mean the side surfaces of the entire stacking sequence. The term "side surface" is understood to mean the side surface of the active layer.

The first planar electrode extends over the first surface of the active layer in a first region of the active layer. The second planar electrode extends over the first surface of the active layer in a second region of the active layer. The third planar electrode extends over the second surface of the active layer at least in the first region of the active layer and in the second region of the active layer. Preferably, the third planar electrode extends over the entire second surface of the active layer. The bridge conductively connects the first planar electrode to the third planar electrode. Preferably, the surface area of the first region and the surface area of the second region of the active layer result in a total surface area of the active layer such that the first planar electrode and the second planar electrode extend over the entire first surface of the active layer (minus an insulating region, such as an insulating line, disposed between the first planar electrode and the second planar electrode).

The active layer preferably has a first segment at least in the first region and a second segment at least in the second region. In other words, the active layer is preferably divided into first segments at least in the first region and into second segments at least in the second region. Thus, the first segment of the active layer is arranged substantially in line with the first planar electrode and the second segment of the active layer is arranged substantially in line with the second planar electrode. By dividing the active layer into segments, the appearance of the functional element is improved. If the active layer is not divided into individual segments, unsightly visual anomalies may occur between the regions, such as gradual visual changes in the first region of the active layer as the optical properties of the second region change. The division of the active layer at least into the first segment and the second segment is preferably produced by a segmented segment by means of laser radiation.

The first planar electrode has a first protruding region with respect to the active layer, and the second planar electrode has a second protruding region with respect to the active layer. The first bus bar is disposed at least on the first protruding region, and the second bus bar is disposed at least on the second protruding region. The first planar electrode and the second planar electrode are electrically insulated from each other. In other words, the first planar electrode protrudes beyond the active layer in a first portion of the peripheral side surface, and the second planar electrode protrudes beyond the active layer in a second portion of the peripheral side surface. The first bus bar is disposed at least on the protruding region of the first planar electrode, and the second bus bar is disposed at least on the protruding region of the second planar electrode. The first planar electrode and the second planar electrode are arranged to be electrically insulated from each other. Preferably, the first planar electrode is separated from the second planar electrode by an insulated wire, for example introduced by means of laser ablation.

Within the meaning of the present invention, "peripheral side surface of the active layer" is understood to mean an outer peripheral surface extending perpendicularly to the first and second surfaces of the active layer. The first and second surfaces of the active layer are major surfaces of the active layer that are disposed substantially parallel to major surfaces of the outer and inner sheets of the laminate sheet. The peripheral side surface of the active layer thus includes the peripheral side surface of any individual segment of the active layer, minus the portion of the peripheral side surface of the segment that does not extend along the edge of the functional element. Within the meaning of the invention, this means that all parts of the peripheral side surface of the first segment facing the peripheral side surface of the second segment (or of a further segment of the active layer which may be present) are not part of the peripheral side surface of the active layer. Vice versa, this applies to all parts of the peripheral side surface of the second segment facing the peripheral side surface of the first segment (or of a further segment of the active layer which may be present).

If the active layer is divided into segments, the term "first surface of the active layer" is understood to mean the first surface of the first segment and the first surface of the second segment of the active layer as well as the first surface of any further segments. It is understood that the term "second surface of the active layer" within the meaning of the present invention is understood to mean the second surface of the first segment and the second surface of the second segment of the active layer as well as the second surface of any further segments. The first surfaces of the respective segments are arranged immediately adjacent to each other such that the first surfaces of the respective segments are vertically offset from each other in a plan view of the laminated sheet, rather than horizontally. This means that if the first surface of the first segment faces the outer sheet, the first surface of the second segment also necessarily faces the outer sheet. Vice versa, the same applies to the second surface of the first segment and to the second surface of the first segment. In this case, the first surface of the active layer is thus derived from the first surface of the first segment and from the first surface of the second segment and from the first surface of any further segments. The second surface of the active layer is thus derived from the second surface of the first segment and from the second surface of the second segment and from the second surface of any further segments.

The bus bars are connected to the planar electrodes in such a way that different optical states of the functional element can be activated when the first and second bus bars are in electrical contact with a voltage source. If an electric potential is applied to the first planar electrode, the electric potential is also applied to the third planar electrode via the bridge. A counter potential is applied to the second planar electrode via the second bus bar such that a second region of the active layer arranged between the second planar electrode and the third planar electrode is able to change its optical state in accordance with an applied voltage difference between the planar electrodes. Since the second planar electrode and the first planar electrode are arranged to be electrically insulated from each other, a short circuit does not occur.

A significant advantage of the invention is that the solution according to the invention allows planar electrodes with bus bars to be arranged on only one surface of the active layer, which provides design freedom in the production of the laminate sheet. Typically, a first bus bar must be connected to a planar electrode on a first surface of an active layer and a second bus bar must be connected to a planar electrode on a second surface of the active layer, resulting in greater space requirements, which may conflict with the desired properties of the laminated sheet. In addition, production is significantly more complicated, since the functional element has to be in contact with the bus bar from both sides. In the solution according to the invention, the first planar electrode extends over the first surface in a first region of the active layer and the second planar electrode extends over the first surface in a second region of the active layer. The first planar electrode is connected to the first bus bar in a region of the first planar electrode protruding from the active layer, and the second planar electrode is connected to the second bus bar in a region of the second planar electrode protruding from the active layer. The first planar electrode and the second planar electrode largely prevent diffusion of contaminants (e.g., plasticizers) from the thermoplastic intermediate layer into the active layer via the first surface of the active layer. This arrangement allows for a reduction in the number of barrier layers used to prevent diffusion of contaminants into the active layer. This can slow down the ageing of the functional element, which essentially occurs as a result of penetration of harmful substances into the interior of the functional element via the unprotected surface of the active layer and change the optical properties of the functional element in an undesired manner. For example, aging causes the functional element to become brighter or a change in transmittance from its side edges.

In a preferred embodiment of the invention, the first planar electrode, the second planar electrode and any further planar electrode applied to the first surface of the active layer together protrude along the entire peripheral side surface of the active layer. This means that the planar electrodes (minus the one or more insulating regions arranged between the planar electrodes) protrude along the entire peripheral side surface of the active layer. At least one insulating region between the first planar electrode and the second planar electrode is used to electrically insulate the planar electrodes from each other. The insulating region is preferably linear (insulating wire). The active layer is very effectively protected from contaminant diffusion due to the largely uninterrupted protrusion of the planar electrode along the peripheral side surface of the active layer. In this way, fewer barrier layers are required, which saves material costs and minimizes process costs.

Preferably, the first protruding region and the second protruding region together protrude beyond the active layer along the entire peripheral side surface.

Preferably, the first planar electrode and/or the second planar electrode protrude at least 1mm, preferably at least 5mm, relative to the active layer. In other words, the first planar electrode and/or the second planar electrode and any further planar electrode have a protrusion u of at least 1mm, particularly preferably at least 5mm, relative to the active layer. Within the meaning of the invention, the protrusions are determined by the distance of the outer edge of the planar electrode from the outer edge of the active layer in the protruding region. The distance mentioned here is a distance orthogonal to the side surface of the active layer. If the projections over the entire functional element have a variable size, the arithmetic mean of the projections u is preferably at least 1mm, particularly preferably at least 5 mm. The bus bar can be connected to the planar electrode from the mentioned sized protrusion in a simplified process.

In a particularly preferred embodiment of the functional element, the active layer comprises a further region, preferably at least one further region, particularly preferably at least 3 further regions, most particularly preferably at least 5 further regions, in particular at least 8 further regions. Exactly one further planar electrode is applied to the first surface of each further region. Each region is electrically connected to exactly one planar electrode on the first surface, and each additional planar electrode is electrically connected to exactly one region of the active layer. The third planar electrode extends over the second surface of all further areas. The further planar electrodes each protrude beyond the active layer in a further portion of the peripheral side surface of the active layer. Each further planar electrode is preferably electrically conductively connected to exactly one further bus bar, wherein on their area protruding relative to the active layer the further planar electrodes are preferably electrically conductively connected to the further bus bars. The further planar electrodes, the first planar electrode and the second planar electrode are arranged electrically insulated from each other, for example, they are separated from each other by one or more linear insulating regions (insulating lines). By bringing the second and further regions of the active layer into contact with different planar electrodes, the regions of the active layer can be activated and switched independently of each other. In this configuration, the first planar electrode, the bridge and the third planar electrode preferably function as anodes, while the second planar electrode and the further planar electrode function as cathodes and may have different (cathodic) potentials. The voltage difference between the anode on one side and the cathode on the other side allows the various regions of the active layer to transition to different desired optical states. It is particularly preferred that each region of the active layer is also a respective segment of the active layer, such that the first region is a first segment, the second region is a second segment, and each further region is a further segment.

In a preferred embodiment of the invention, the first planar electrode, the second planar electrode and any further planar electrodes are formed by means of laser radiation (laser ablation). In other words, the initially non-segmented continuous planar electrode is divided into a plurality of planar electrodes (at least a first planar electrode and a second planar electrode) by means of laser radiation. The third planar electrode is preferably not segmented by laser radiation. Preferably, the segments of the active layer (i.e. at least the first segment and the second segment) are also produced by means of laser radiation. In other words, an initially unsegmented active layer having a continuous planar electrode arranged on a first surface of the active layer is divided into a plurality of segments (at least a first segment and a second segment) and a plurality of planar electrodes (at least a first planar electrode and a second planar electrode) by means of laser radiation. The third planar electrode is not segmented by laser radiation.

In an alternative embodiment, the functional element already has an active layer, which element is divided into at least a first segment and a second segment and preferably further segments, for production-related reasons. The first and second planar electrodes, as well as any further planar electrodes, may also be applied to the active layer separately during production, so that no insulating regions have to be introduced later.

If the active layer has a further region or segment, the third planar electrode preferably also extends completely on the second surface of the further region or in the region of the further segment. In particular, the third planar electrode extends over the entire second surface of the active layer. This ensures that the functional element can be used to its maximum extent and has good optical quality. Any area not covered by the third planar electrode may result in non-uniform optical properties in the affected area, which may cause irritation to the user.

The laminated sheet is for example designed as a windscreen or roof sheet, which is intended to be part of a vehicle. Alternatively, the laminated sheet is designed, for example, as a glass partition, preferably for rail vehicles or buses. Alternatively, the laminated sheet may be, for example, a building glazing in an exterior facade of a building or a glass separator in an interior of a building.

The terms "outer sheet" and "inner sheet" arbitrarily describe two different sheets. In particular, the outer sheet can be referred to as a "first sheet", and the inner sheet can be referred to as a "second sheet".

If the laminated sheet is arranged in a window opening of a vehicle or building to separate the interior from the outside environment, the sheet (second sheet) facing the interior (vehicle interior) is referred to as "inner sheet" within the meaning of the present invention. The sheet facing the external environment (first sheet) is referred to as "outer sheet". However, the present invention is not limited thereto. The inner sheet has an inner side surface facing away from the thermoplastic intermediate layer and an outer surface facing the thermoplastic intermediate layer. The inner side surface of the inner sheet is also the inner side surface of the laminate sheet. The outer sheet has an outer surface facing away from the thermoplastic intermediate layer and an inner surface facing the thermoplastic intermediate layer. The outer surface of the outer sheet is also the outer surface of the laminate sheet.

In an advantageous embodiment of the laminate sheet according to the invention, the thermoplastic intermediate layer comprises a polymer, preferably a thermoplastic polymer.

In a particularly advantageous embodiment of the laminate sheet according to the invention, the thermoplastic intermediate layer comprises at least 3 wt.%, preferably at least 5 wt.%, particularly preferably at least 20 wt.%, even more preferably at least 30 wt.% and in particular at least 40 wt.% of plasticizer. The plasticizer preferably comprises or consists of triethylene glycol bis (2-ethylhexanoate).

Plasticizers are chemical compounds that make plastic materials softer, more pliable, smoother and/or more elastic. They shift the thermo-elastic range of the plastic material to lower temperatures, so that the plastic material has the desired more elastic properties in the operating temperature range. Further preferred plasticizers are carboxylic esters, in particular low-volatility carboxylic esters, fats, oils, soft resins and camphor. The further plasticizer is preferably an aliphatic diester of triethylene glycol or tetraethylene glycol. Particularly preferred for use as plasticizers are 3G7, 3G8 or 4G7, wherein the first digit refers to the number of ethylene glycol units and the last digit refers to the number of carbon atoms in the carboxylic acid moiety of the compound. 3G8 thus represents triethylene glycol bis (2-ethylhexanoate), i.e., a compound of formula C₄H₉CH (CH₂CH₃) CO (OCH₂CH₂)₃O₂CCH (CH₂CH₃) C₄H₉.

In a further particularly advantageous embodiment of the laminate sheet according to the invention, the intermediate layer comprises at least 60 wt.%, preferably at least 70 wt.%, particularly preferably at least 90 wt.% and in particular at least 97 wt.% of polyvinyl butyral.

The thermoplastic interlayer can be formed from a single film or can also be formed from more than one film. The thermoplastic intermediate layer can be formed from one or more thermoplastic films arranged on top of each other, wherein the thickness of the thermoplastic intermediate layer after lamination of the layer stack is preferably from 0.25 mm to 1mm, typically 0.38 mm or 0.76 mm. If the thickness varies across the surface area of the laminate, the values given relate to the thickness at the thickest point of the thermoplastic interlayer.

In a preferred embodiment of the present invention, the thermoplastic interlayer comprises at least a first thermoplastic laminate film and a second thermoplastic laminate film. The functional element is disposed between the first thermoplastic laminate film and the second thermoplastic laminate film. The first laminated film and the second laminated film are preferably arranged in a planar manner to be stacked on top of each other and laminated together with the functional element interposed between the two laminated films. The region of the laminate film overlapping the functional element forms a region connecting the functional element to the outer sheet and the inner sheet, whereby the functional element is fixed in the laminate sheet. In other areas of the laminated sheet where the intermediate layers are in direct contact with each other, they can melt during lamination in such a way that the two original layers may no longer be identifiable, but instead there is a uniform intermediate layer.

Particularly preferably, the thermoplastic intermediate layer further comprises a third thermoplastic laminate film arranged peripherally around the functional element. In other words, the functional element (more precisely, the side surface of the functional element) is peripherally surrounded by the third thermoplastic laminate film. The third laminated film is frame-shaped with a cutout into which the functional element is inserted. The third laminate film can be formed from a thermoplastic film into which a slit has been introduced by cutting. Alternatively, the third laminate film can also be composed of a plurality of film portions surrounding the functional element.

The thermoplastic intermediate layer is preferably formed from a total of at least three thermoplastic laminated films arranged on top of one another in a planar manner, wherein the intermediate laminated film (third laminated film) has a cutout in which the functional element is arranged. During production, the third laminate film is arranged between the first laminate film and the second laminate film, wherein the side surfaces of all laminate films facing the external environment are preferably arranged in alignment. The third laminate preferably has substantially the same thickness as the functional element. This compensates for local thickness differences of the laminated sheet, which differences are introduced by the locally defined functional elements, so that glass breakage during lamination can be avoided.

The side surface of the functional element, which is visible when viewed through the laminate sheet, is preferably arranged flush with the third laminate film, such that there is no gap between the side surface of the functional element and the associated side surface of the third laminate film. Thus, the boundary between the third laminate film and the functional element is visually less noticeable. In the region in which the planar electrode protrudes relative to the active layer, the side surface of the functional element is understood to mean the side surface of the active layer, wherein at least one barrier layer is preferably arranged between the side surface of the active layer and the third lamination.

The thickness of each thermoplastic laminate film is preferably from 0.1 mm to 2 mm, particularly preferably from 0.2 mm to 1 mm.

In a preferred development of the laminate according to the invention, the region of the first and/or second thermoplastic laminate film via which the functional element is connected to the outer sheet or the inner sheet is colored or tinted. In other words, at least the region of the first and/or second thermoplastic laminate film that coincides with the functional element when viewed through the laminate sheet is colored or tinted. Thus, the transmittance of this region in the visible spectrum is reduced compared to an uncolored or uncolored layer. The colored/tinted region of the laminate film thus reduces the transmittance of the laminate sheet in that region. This may be useful, for example, in the case of the functional element acting as a sun visor. In particular, the aesthetic impression of the functional element is improved, since the coloration results in a more neutral appearance, which is more pleasant to the observer.

The colored or tinted region of the first and/or second thermoplastic laminate film preferably has a light transmission in the visible spectrum range of from 10% to 50%, particularly preferably from 20% to 40% (according to ISO 9050:2003). Thus, particularly good results are achieved with respect to antiglare protection and visual appearance.

The thermoplastic intermediate layer can be formed from a single thermoplastic laminate film in which the colored or tinted regions are created by localized coloring or dyeing. Such films may be obtained, for example, by coextrusion. Alternatively, the uncolored film portion and the colored or tinted film portion may be combined to form the thermoplastic layer.

In an advantageous embodiment, at least, preferably exclusively, the region of the thermoplastic intermediate layer arranged between the functional element and the inner sheet and/or the outer sheet is colored. This gives a particularly attractive impression when the inner sheet and/or the outer sheet are viewed from above.

In a preferred embodiment of the invention, at least a portion of the peripheral side surface of the active layer is sealed with at least one barrier layer. Preferably, all portions of the peripheral side surface of the active layer are sealed with one or more barrier layers. In addition, the area of the second surface of the active layer that is preferably free of the third planar electrode may also be sealed with one or more barrier layers. The barrier layer can partially overlap the edge region of the third planar electrode, for example if this is suitable for production purposes. This results in a particularly reliable sealing of the active layer of the functional element and a particularly good aging resistance of the functional element.

For simplicity, reference is hereinafter generally made to "barrier layer" only, which may also mean a plurality of barrier layers within the meaning of the present invention unless explicitly or implicitly excluded.

By "sealed" within the meaning of the present invention is meant that the corresponding portion of the surface is completely covered by the barrier layer as a protective layer and thereby making this portion more durable and durable, in particular against diffusion of harmful substances such as moisture, but in particular also against plasticizers from the environment which might otherwise penetrate into the interior of the active layer.

The barrier layer is preferably in direct and immediate contact with the active layer. For example, there is no separate adhesive or other intermediate layer between the barrier layer and the active layer of the functional element.

In an advantageous embodiment of the invention, the barrier layer is designed in such a way that it prevents diffusion of plasticizer from the thermoplastic intermediate layer through the barrier layer.

The barrier layer is preferably designed in such a way that it prevents diffusion of the plasticizer through the barrier layer to the same or greater extent than diffusion of the plasticizer through the planar electrode.

The barrier layer is preferably single-layered or multi-layered, such as two-layered, three-layered, four-layered or five-layered. The individual layers of the barrier layer are also referred to hereinafter as single layers and may consist of the same material or different materials.

The single layer(s) of the multilayer barrier layer preferably comprise a transparent material. Within the meaning of the present invention, the term "transparent" refers to a barrier layer having a light transmittance in the visible spectrum of more than 50%, preferably more than 70% and in particular more than 90% (according to ISO 9050:2003). However, the transmission may also be much lower, for example greater than 5%, for sheets or sheet portions that are not in the driver's relevant field of view, such as the top sheet or upper region of the windshield, or if a particular darkening is desired. In particular, the barrier layer can be colored or tinted.

In an advantageous embodiment of the invention, the single layer(s) are metal oxide-based, metal nitride-based or metal oxynitride-based, wherein the metal is preferably silicon (Si), aluminum (Al), tantalum (Ta) or vanadium (V) or a mixture thereof.

The layer comprising metal oxide, metal nitride or metal oxynitride may additionally be doped with, for example, antimony, fluorine, silver, ruthenium, palladium, aluminum and tantalum.

In the context of the present invention, the term "based on" in relation to the composition of the barrier layer means that the material consists essentially of metal oxide, metal nitride or metal oxynitride, preferably at least 80 wt. -%, particularly preferably at least 90 wt. -%, and in particular at least 95 wt. -%. In the case of metal oxides, metal nitrides or metal oxynitrides, which are produced in particular by chemical vapor deposition, such as plasma-enhanced vapor deposition, the term "based on" includes the fact that small amounts of process gas residues, such as carbon and hydrogen, as organic residues of organometallic compounds, may be contained in addition to the metal oxides, metal nitrides or metal oxynitrides.

Particularly preferred single layers are silicon oxide-based, silicon nitride-based or silicon oxynitride-based. In the case of a single layer based on silicon oxide, the silicon oxide SiOx is preferably sub-stoichiometric (particularly preferably wherein 1< x < 2) or stoichiometric (x=2). However, it may also be superstoichiometric.

In an advantageous embodiment of the barrier layer, the barrier layer comprises or consists of at least one single layer of a silicone of the type SiOxCy: H, wherein x is preferably from 0.1 to 3 and particularly preferably from 0.2 to 2, and y is preferably greater than 0.3, particularly preferably from 0.3 to 3 and particularly from 0.9 to 2.

The hydrogen content of the organosilicon compound depends on the degree of polymerization and the chemistry of the deposition process. The ratio of carbon to hydrogen (CuHv) can be arbitrary and is preferably from 1:1000 to 1000:1, particularly preferably from 1:10 to 10:1.

In an alternative barrier layer, at least one single layer comprises or consists of silicone, wherein the CyHz content of the silicone coating is from 20 to 80 wt%, preferably from 30 to 70 wt%. Such silicone coatings are preferably highly crosslinked and have polymeric properties.

Further preferred single layers comprise or consist of amorphous hydrogenated carbon (a-C: H), preferably amorphous hydrogenated carbon doped with nitrogen (a-C: N: H) or amorphous hydrogenated carbon doped with nitrogen and silicon (a-C: N: si: H). They are preferably produced by CVD methods using acetylene (C2H 2) or acetylene-containing process gases.

Further preferred single layers comprise other transparent ceramic layers and/or polymer layers that can be produced by vapor deposition methods and reduce or substantially prevent diffusion of plasticizers such as parylene, polyvinylidene chloride (PVDC), ethylene vinyl alcohol copolymer (EVOP), or polyacrylates.

In a particularly advantageous embodiment, the barrier layer comprises at least two, preferably exactly two, exactly three, exactly four or exactly five single layers of the same material arranged one above the other. This is particularly advantageous for thin single layers used herein, as defects in one of the single layers can be compensated for by the other single layer(s).

In a particularly advantageous embodiment, the barrier layer comprises exactly one or at least one two-layer, also referred to as a bilayer or a binary group. The bilayer is preferably composed of a first single layer having polymeric properties and a second single layer having ceramic or inorganic properties. The first single layer is preferably arranged on the side of the bilayer facing the functional element. The first single layer of the bilayer is particularly preferably arranged directly on the active layer (i.e. the second surface and/or the peripheral side surface).

In an advantageous embodiment, one or more adhesion promoting layers can be arranged between the functional element and the barrier layer. In particular, the peripheral side surface of the active layer of the functional element must be subjected to an adhesion promoting surface treatment. The stacking sequence can thus be exposed to an argon (Ar) plasma, a nitrogen (N2) plasma or an oxygen (O2) plasma for surface treatment.

In an advantageous embodiment, the entire barrier layer comprising one or more single layers has a thickness d (also referred to as material thickness) of 10 nm to 5000 nm (nanometers), preferably 15 nm to 1000 nm and particularly preferably 15 nm to 500 nm. The layer thickness d refers to a measurement of the thickness of the individual layers applied to the substrate or of a plurality of layers arranged one above the other as a layer sequence. It is measured in the vertical direction from the surface of the substrate (in this case the peripheral side surface or second surface of the active layer) to the surface of the applied layer or layer sequence.

The barrier layer can be produced by any suitable deposition process. A vapor deposition process is particularly suitable which allows for the controlled production of particularly thin barrier layer thicknesses d.

The following deposition process is particularly suitable for producing barrier layers:

physical Vapor Deposition (PVD), particularly preferred evaporation, such as thermal evaporation, electron beam evaporation, laser beam evaporation, ion Assisted Deposition (IAD) or arc evaporation;

Cathode sputtering (such as magnetron sputtering), atomic layer deposition (such as Plasma Enhanced Atomic Layer Deposition (PEALD)).

Chemical Vapor Deposition (CVD), particularly preferably Plasma Enhanced Chemical Vapor Deposition (PECVD), low pressure PECVD (LPCVD), low temperature low pressure PECVD.

For functional elements with a polymeric carrier film and a temperature sensitive active layer, the aforementioned plasma enhanced processes (such as PECVD and PEALD) are particularly suitable, as they only allow deposition at low substrate temperatures.

Additional barrier layers (also known as barrier films) are generally known to those skilled in the art. They may be designed, for example, as disclosed in WO2018188844A1 or WO2019077014 A1.

The controllable functional element comprises an active layer between planar electrodes and is designed like a membrane. The active layer has controllable optical properties that can be controlled via a voltage applied to the planar electrode.

At least the first bus bar and at least the second bus bar and any further bus bars are arranged to be electrically connected to an external voltage source in a manner known per se. The electrical contact is made by means of a suitable connecting cable, such as a foil conductor.

The planar electrodes (i.e. at least the first planar electrode, the second planar electrode and the third planar electrode) are preferably designed as transparent conductive layers. The planar electrode preferably comprises at least one metal, one metal alloy or one Transparent Conductive Oxide (TCO). The planar electrode may for example comprise silver, gold, copper, nickel, chromium, tungsten, indium Tin Oxide (ITO), gallium-doped or aluminium-doped zinc oxide and/or fluorine-doped or antimony-doped tin oxide. The planar electrode preferably has a thickness of 10 nm to 2 μm, particularly preferably 20 nm to 1 μm, most particularly preferably 30nm to 500 nm.

In addition to the active layer and the planar electrode, the functional element can also have other layers known per se, such as barrier layers, antireflection layers, protective layers and/or smoothing layers.

The planar electrode is preferably applied to the carrier film. In such an embodiment of the functional element, the planar electrode and the active layer are arranged between the carrier films. The carrier film thus forms the surface of the functional element. The functional element can thus be provided as a laminate film which can be advantageously handled. The functional element is advantageously protected from damage, in particular from corrosion, by the carrier film. The functional elements comprise at least, in the order given:

A first carrier film;

a first planar electrode and a second planar electrode;

an active layer;

Third plane electrode, and

A second carrier film.

The first and second planar electrodes and any further planar electrodes are preferably applied to exactly one continuous carrier film, i.e. arranged between the carrier film and the active layer. The carrier film thus carries the planar electrode and provides the necessary mechanical stability to the liquid or soft active layer.

The first planar electrode, the second planar electrode, the third planar electrode and/or any further planar electrode may also be designed as a conductive foil, preferably a metallic foil, in particular a foil made of copper or silver. Alternatively, the planar electrode may be applied to the carrier film, e.g. the planar electrode is a coating on the carrier film.

With respect to the insulated wires between the planar electrodes, the carrier film and/or the segments of the active layer, the insulated wires have a width of, for example, 5 μm to 500 μm, in particular 20 μm to 200 μm. The width of the segments (i.e. the distance between adjacent insulated wires) can be suitably selected by a person skilled in the art according to the requirements in each case.

The insulated wire can be introduced during production of the functional element by laser ablation, mechanical cutting or etching. The already laminated functional element can still be segmented by means of laser ablation.

In an alternative embodiment, the first planar electrode is preferably arranged on the first carrier film, the second planar electrode is preferably arranged on the second carrier film, and the third planar electrode is preferably arranged on the third carrier film. Any further planar electrodes are each arranged on a further carrier film. The carrier film preferably has at least the same surface area as the planar electrode applied to the carrier film, but may also have a larger surface area. The first carrier film and the second carrier film and any further planar electrodes are preferably separated from each other by insulating regions, particularly preferably by insulating wires.

The carrier film preferably comprises at least one thermoplastic polymer, particularly preferably low-plasticizer or plasticizer-free polyethylene terephthalate (PET). This is particularly advantageous for the stability of the functional element. However, the carrier film may also comprise or consist of other low-plasticizer or plasticizer-free polymers, such as Ethylene Vinyl Acetate (EVA), polypropylene, polycarbonate, polymethyl methacrylate, polyacrylate, polyvinyl chloride, polyacetate resins, casting resins, acrylates, fluorinated ethylene propylene, polyvinyl fluoride and/or ethylene tetrafluoroethylene. The thickness of each carrier film is preferably from 0.02 mm to 1mm, particularly preferably from 0.04 mm to 0.2 mm. The carrier film provides particularly effective protection against diffusion of plasticizer into the active layer.

The functional element is preferably a PDLC functional element (polymer dispersed liquid crystal). The active layer of the PDLC functional element comprises liquid crystal embedded in a polymer matrix. If no voltage is applied to the planar electrodes, the liquid crystals align in a disordered manner, which results in strong scattering of light passing through the active layer. If a voltage is applied to the planar electrode, the liquid crystals in the second region of the active layer and in any further region of the active layer are aligned in a common direction and the transmission of light through the active layer increases. Alternatively, it is possible to use a functional element, and in particular a PDLC functional element, which is transparent when no voltage is applied (zero volts) and strongly scatters when a voltage is applied.

In principle, it is also possible to use other types of controllable functions, such as electrochromic functions or SPD functions (suspended particle devices). The controllable functional elements mentioned and their modes of operation are known per se to the person skilled in the art and therefore a detailed description is not required here. PDLC functional elements are particularly preferred, since, in particular with regard to PDLC elements, effective protection against plasticizers must be ensured in order not to impair the optical quality of the functional element.

The second region of the active layer is capable of changing its optical state by applying a voltage to the first and second bus bars. The first region of the active layer is not intended to change its optical state and is therefore preferably as small as possible. The first region preferably has a surface area of less than or equal to 10 cm ², particularly preferably less than or equal to 2 cm ², particularly less than or equal to 1 cm ². All further areas of the active layer are preferably designed such that they can change their optical state by applying a voltage to the bus bar connected thereto.

The second region of the active layer is larger, preferably at least 5 times larger, particularly preferably at least 10 times larger, in particular at least 100 times larger, in its area than the first region of the active layer.

Functional elements are commercially available. The functional elements are typically cut into desired shapes and sizes from larger sized multilayer films. This can be done mechanically, for example with a blade. In an advantageous embodiment, the cutting is performed by means of a laser. It has been found that in this case the side surfaces are more stable than with mechanical cutting. In the case of mechanically cutting the side surfaces, there may be a risk of shrinkage of the material, which can be said to be visually perceptible and adversely affect the aesthetic properties of the sheet.

Within the meaning of the present invention, electrically controllable optical properties are understood to mean continuously controllable properties, but equally also properties that can be switched between two or more discrete states.

The electrical control of the functional elements of the sheet according to the invention installed in the vehicle is carried out, for example, by means of switches, knobs or sliders integrated into the meter of the vehicle. However, buttons for controlling the functional elements (e.g. capacitive buttons) may also be integrated in the laminate. Alternatively or additionally, the functional elements can be controlled by non-contact methods (e.g. by recognizing gestures) or depending on the state of the pupil or eyelid determined by the camera and suitable evaluation electronics. Alternatively or additionally, the functional element may be controlled by a sensor detecting light incidence on the sheet.

In an advantageous embodiment of the invention, the bus bar is applied to the protruding areas of the first planar electrode or the second planar electrode and any further planar electrodes by welding or gluing. The bus bars applied in this way are preferably designed as wires or strips of a conductive foil. In this case, the bus bar comprises, for example, at least aluminum, copper, tin-plated copper, gold, silver, zinc, tungsten and/or tin or an alloy thereof. The strips preferably have a thickness of 10 μm to 500 μm, particularly preferably 30 μm to 300 μm. Bus bars made from conductive foils having these thicknesses are technically easy to implement and have advantageous current carrying capacities. The strips can be conductively connected to the conductive structure, for example, via a solder, via a conductive adhesive, or by direct placement.

Alternatively, the first and/or second bus bar and/or any further bus bar are designed as printed and fired conductive structures. The printed bus bar preferably comprises at least one metal, metal alloy, metal compound and/or carbon, particularly preferably a noble metal, and in particular silver. The printing paste preferably comprises metallic particles, metallic particles and/or carbon, and in particular noble metal particles, such as silver particles. The conductivity is preferably achieved by conductive particles. The particles may be in an organic and/or inorganic matrix (such as a paste or ink) and are preferably as a printing paste with a frit.

The layer thickness of the printed bus bar is preferably from 5 μm to 40 μm, particularly preferably from 8 μm to 20 μm, and most particularly preferably from 8 μm to 12 μm. Printed bus bars having these thicknesses are technically easy to implement and have advantageous current carrying capacities.

The specific resistance ρ _a of the first and/or second and/or any further bus-bars is preferably from 0.8 μΩ·cm to 7.0 μΩ·cm and particularly preferably from 1.0 μΩ·cm to 2.5 μΩ·cm. Bus bars having a specific resistance in this range are technically easy to implement and have a favorable current carrying capacity.

The first bus bar, the second bus bar and/or any further bus bar are preferably applied to the surface of the particular planar electrode facing the active layer of the functional element. This arrangement is simpler because the planar electrode is preferably arranged between the active layer and the carrier film and is thus hardly connectable to the bus bar via the surface of the planar electrode facing away from the active layer. In principle, the first bus bar, the second bus bar and/or any further bus bar may also be applied to the surface of the planar electrode facing away from the active layer. For this purpose, the carrier film (if present) may, for example, have cutouts through which the bus bars and the planar electrodes can be connected to one another.

The first and second bus bars are preferably arranged in opposite edge regions of the functional element or alternatively at right angles, i.e. arranged offset from each other by substantially 90 °. Any further bus bars are preferably arranged relative to the first bus bar in the same way as the second bus bar. If the laminate sheet is used as a vehicle sheet in a vehicle, the bus bars are preferably arranged such that they are hidden by the covering print of the vehicle sheet.

In an advantageous embodiment of the invention, the bridge is designed as a metal foil or a metallic wire. The conductive bridge can be applied to the first planar electrode, the third planar electrode, and a portion of the peripheral side surface of the active layer by means of an adhesive layer. The conductive bridge comprises, for example, at least aluminum, copper, tin-plated copper, gold, silver, zinc, tungsten, and/or tin or alloys thereof. The bridge preferably has a thickness of 5 μm to 400 μm, particularly preferably 40 μm to 250 μm. Conductive bridges of these thicknesses are technically easy to implement and have a favorable current carrying capacity. The conductive bridge may also be conductively connected to the conductive structures (the first planar electrode and the third planar electrode), for example via a solder, via a conductive adhesive or by direct placement. The conductive bridge may be introduced into the functional element, for example, after the planar electrode has been connected to the active layer.

Alternatively, the conductive bridge is designed as a conductive paste. The conductive bridge may for example be arranged in a via hole in the first region of the active layer (e.g. a hole-like incision in the active layer) such that a direct electrical connection between the first planar electrode and the third planar electrode is possible. The printing paste preferably comprises at least one metal, metal alloy, metal compound and/or carbon, particularly preferably a noble metal, and in particular silver. The conductivity is alternatively achieved by conductive particles. The particles may be in an organic and/or inorganic matrix (such as a paste or ink) and are preferably as a printing paste with a frit. The diameter of the printing paste is preferably at least 5 μm, particularly preferably at least 20 μm, and most particularly preferably at least 50 μm. In this arrangement, the conductive bridge is completely encapsulated by the active layer and the planar electrode, and is thus well protected from external influences.

The specific resistance ρ _a of the conductive bridge is preferably from 0.8 μΩ·cm to 7.0 μΩ·cm, and particularly preferably from 1.0 μΩ·cm to 2.5 μΩ·cm.

Depending on the material of the conductive bridge, it may be advantageous to protect the conductive bridge with a protective layer (e.g., a coating or a polymer film).

The first bus bar is preferably electrically conductively connected to the first planar electrode by means of a conductive material comprising silver, particularly preferably the material is designed based on silver. The second bus bar is preferably conductively connected to the second planar electrode by means of a conductive material, preferably based on silver. It is understood that any further bus bars are also preferably connected to the further planar electrodes by means of an electrically conductive material, preferably based on silver. The conductive material is applied at least, preferably exclusively, between the bus bar and the protruding areas of the planar electrodes to which the bus bar is connected. This arrangement can be produced quickly and easily, wherein the silver-containing material is characterized by high electrical conductivity and relatively long-term stability.

If something is formed "based on" a material, the owner consists essentially of, and in particular consists of, the material, except for any impurities or dopants. Unless indicated otherwise, the layer thickness or gauge of thickness is related to the geometric thickness of the layer.

The laminated sheet with the electrically controllable functional element can advantageously be designed as a windscreen with the functional element as an electrically controllable sun visor. Such windshields have an upper edge and a lower edge and two side edges extending between the upper edge and the lower edge. The upper edge means an edge intended to be directed upwards in the mounted position. The lower edge means an edge intended to be directed downwards in the mounted position. The upper edge is also commonly referred to as the top edge, and the lower edge is also commonly referred to as the engine edge.

Windshields have a central field of view where high demands are placed on their optical quality. The central field of view must have a high light transmittance (according to ISO 9050:2003) (typically greater than 70%). The central field of view is in particular a field of view known to the person skilled in the art as field of view B, observation area B or zone B. The field of view B and its technical requirements are defined in the code 43 of the European Commission of the United nations (UN/ECE) (ECE-R43, "unified regulations regarding the approval of safety vitrified materials and their installation on vehicles"). The field of view B is defined in the attachment 18 there.

The functional element is advantageously arranged above the central field of view (field of view B). This means that the functional element is arranged in the region between the central field of view and the upper edge of the windscreen. The functional element does not have to cover the entire area, but is positioned completely within this area and does not project into the central field of view. In other words, the functional element is at a smaller distance from the upper edge of the windscreen than the central viewing area. The transmission of the central field of view is thus not impaired by the functional element, which in the folded down state is positioned in a similar position to a conventional mechanical sun visor.

The functional element is preferably arranged over the entire width of the laminate or the windscreen (minus the edge area of the width on both sides, e.g. 2mm to 20 mm). The functional element is also preferably at a distance of, for example, 2mm to 20mm from the upper edge. The functional element is thus encapsulated within the laminate and protected from contact with the surrounding atmosphere and from corrosion.

The upper edge of the functional element and the adjacent side surface or all side surfaces are preferably hidden by opaque overlay print or by the outer frame when viewed through the laminated sheet. Windshields and vehicle roof sheets typically have a fully encircling peripheral cover print made of opaque enamel, which is used in particular to protect the adhesive for mounting the windshield from UV radiation and to hide the adhesive from view. The peripheral overlay print preferably also serves to conceal the upper edge and side surfaces of the functional element, as well as the required electrical connections including the bus bars. The functional element is then advantageously integrated into the appearance of the laminate sheet and only the lower edge may potentially be seen by a viewer. Preferably, both the outer sheet and the inner sheet have a covering print such that viewing through them is obscured from both sides.

The functional element may also have a cut-out or a hole, for example in the area of a so-called sensor window or camera window of a laminate sheet, in particular a windscreen. These areas are intended to be equipped with sensors or cameras whose function will be impaired by controllable functional elements in the beam path, such as rain sensors. It is also possible to realize a window without functional elements having at least two separate functional elements, wherein a distance exists between the functional elements and the distance provides space for a sensor window or a camera window.

The outer and inner sheets are preferably made of glass, particularly preferably soda lime glass, as is customary for window sheets. However, the sheet may also be made of other types of glass (e.g., quartz glass, borosilicate glass, or aluminosilicate glass) or of rigid transparent plastic (e.g., polycarbonate or polymethyl methacrylate). The sheet may be transparent or may be colored or tinted.

The outer sheet, inner sheet and/or intermediate layer may have a further suitable coating known per se, for example an antireflective coating, a non-stick coating, a scratch-resistant coating, a photocatalytic coating or a sun protection coating or a low E coating.

The thickness of the outer and inner sheets can vary greatly and is accordingly adapted to the requirements in each case. The outer sheet and the inner sheet preferably have a thickness of 0.5 mm to 5mm, particularly preferably 1mm to 3 mm.

Furthermore, the invention extends to a vitrification unit comprising a laminated sheet according to the invention. The first and second bus bars and any further bus bars are connected to a voltage source in such a way that different optical states of the second region of the active layer can be activated by means of a voltage change at the bus bars. If present, different optical states can also be activated in further regions of the active layer by means of a voltage change at the bus bar. The voltage change at the bus bar can be generated by a voltage source. The bus bar can be connected to a voltage source by conventional means. The electrical contact is preferably made by means of a suitable connecting cable, such as a foil conductor.

The invention also extends to a method for producing a laminated sheet. The method comprises at least the following method steps in the given order:

a) In a first method step, the first bus bar is connected to a first planar electrode of the functional element, and the second bus bar is connected to a second planar electrode of the functional element.

B) In a second method step, the functional elements are arranged together with the outer sheet, the inner sheet and the thermoplastic intermediate layer to form a layer stack and laminated to form a laminated sheet.

In an advantageous development of the method according to the invention, the thermoplastic intermediate layer in method step b) comprises a first thermoplastic laminate film, a second thermoplastic laminate film and a third thermoplastic laminate film, wherein the functional element is arranged between the first thermoplastic laminate film and the second thermoplastic laminate film, and the third thermoplastic laminate film is arranged such that it encloses the functional element, for example as a frame.

In an advantageous further development of the method according to the invention, in a method step preceding the first method step a), the active layer of the functional element is divided into a first segment and a second segment by means of a segmentation by laser radiation.

The electrical contacting of the bus bar is preferably carried out prior to lamination of the laminate sheet.

Any existing print (e.g., opaque overlay print or printed bus bars for making electrical contact to the functional elements) is preferably applied by screen printing.

Lamination is preferably carried out under the influence of heat, vacuum and/or pressure. Known methods for lamination may be used, such as autoclave methods, vacuum bag methods, vacuum ring methods, calendaring methods, vacuum laminators, or combinations thereof.

Furthermore, the invention comprises the use of a laminate sheet according to the invention with electrically controllable functional elements as an inner glazing or an outer glazing in a building or in a vehicle, preferably as a windscreen or a roof sheet of a vehicle, wherein the electrically controllable functional elements are used as a sun protection, sun visor, or as a privacy protection, preferably as a sun visor.

Furthermore, the invention comprises the use of the laminate sheet according to the invention as a windscreen or roof sheet for a vehicle.

Furthermore, the invention comprises the use of an electrically controllable functional element as a sun visor in a windscreen or roof sheet of a vehicle, wherein the functional element comprises an active layer having a first surface, a second surface and a peripheral side surface, a first planar electrode extending over the first surface in a first region of the active layer, and a second planar electrode extending over the first surface in a second region of the active layer. In addition, the functional element includes a third planar electrode extending over the second surface at least in the first region and the second region of the active layer, and a bridge conductively connecting the first planar electrode to the third planar electrode. The first planar electrode also has a first protruding region relative to the first active layer, and the second planar electrode has a second protruding region relative to the active layer. In addition, the first bus bar is disposed at least on the first protruding region, and the second bus bar is disposed at least on the second protruding region. The first planar electrode and the second planar electrode are electrically insulated from each other.

Drawings

The invention is explained in more detail with reference to the drawings. The figures are schematic representations and are not true to scale. The drawings are not intended to limit the invention in any way. In the drawings:

Fig. 1 shows an embodiment of a functional element with a bus bar in a plan view of the second surface of the functional element, as the functional element is to be mounted in a laminate sheet according to the invention,

Figure 2 shows the functional element of figure 1 in a side view of a first portion of the peripheral side surface of the functional element,

Figure 3 shows the functional element of figure 1 in a further side view of a further portion of the peripheral side surface of the functional element,

Figure 4 shows in a plan view an embodiment of a laminated sheet according to the invention,

Figure 5 is a cross-sectional view of the laminated sheet of figure 4 according to the invention,

Figure 6 shows in plan view a further embodiment of a laminated sheet according to the invention,

FIG. 7 is a cross-sectional view of the laminated sheet of FIG. 6 according to the present invention, an

Fig. 8 is a side view of a functional element as used in the laminated sheet of fig. 6 and 7.

Detailed Description

Fig. 1, 2 and 3 each show details of a functional element 4 having electrically controllable optical properties, as the functional element 4 can be part of a laminated sheet 100 according to the invention. Fig. 1 shows a plan view of the functional element 4, and fig. 2 and 3 each show a side view of the peripheral side surface of the functional element 4. The functional element 4 comprises an active layer 5 having a first surface a, a second surface B and a peripheral side surface S. Fig. 2 shows a side view showing a plan view of a second portion s″ of the peripheral side surface S of the active layer 5. Fig. 3 shows a side view offset by 90 ° relative to the side view in fig. 2. The direction of view in fig. 3 towards the functional element 4 is indicated in fig. 1 by the dashed arrow. The controllable functional element 4 is for example a PDLC multilayer film.

The active layer 5 is divided into a first segment 5.1 and a second segment 5.2. The first planar electrode 6.1 is applied to the first surface a of the active layer 5 in the region of the first segment 5.1. The second planar electrode 6.2 is applied to the first surface a of the active layer 5 in the region of the second segment 5.2. The third planar electrode 6.3 is applied to the second surface B of the active layer 5. The third planar electrode 6.3 extends over the entire second surface B of the active layer 5. The first planar electrode 6.1 and the second planar electrode 6.2 together extend over the entire first surface a of the active layer 5. The bridge 7 conductively connects the first planar electrode 6.1 to the third planar electrode 6.3.

In fig. 1, a linear insulation region is indicated by a dashed line, which separates the first planar electrode 6.1 from the second planar electrode 6.2 and separates the first section 5.1 of the active layer 5 from the second section 5.2 of the active layer 5. In fig. 2, the linear insulation areas between the first planar electrode 6.1 and the second planar electrode 6.2 and between the first segment 5.1 and the second segment 5.2 are represented by visible gaps. The linear insulation region (also called insulation line) serves for electrical insulation in the case of the first planar electrode 6.1 and the second planar electrode 6.2, so that the two electrodes are arranged electrically insulated from each other. In the case of a segmented active layer 5, the insulated wire serves to improve the optical quality of the functional element 4. Insulated wires between the planar electrodes 6.1, 6.2 and the segments 5.1, 5.2 have been introduced into the functional element 4, for example by laser ablation. The insulated wire has a width of, for example, 50 μm.

The active layer 5 also has a peripheral side surface S extending between the first surface a and the second surface B. In a first portion S 'of the peripheral side surface S of the active layer 5, 5.1, the first planar electrode 6.1 protrudes beyond the active layer 5, 5.1 (see fig. 2) such that the first planar electrode 6.1 has a protruding area U' with respect to the active layer 5. In a second portion s″ of the peripheral side surface S of the active layer 5, 5.2, the second planar electrode 6.2 protrudes beyond the active layer 5, 5.2 (see fig. 3), such that the second planar electrode 6.2 has a protruding area u″ relative to the active layer 5. The projection u of the first planar electrode 6.1 relative to the active layer 5 and the projection u of the second planar electrode 6.2 relative to the active layer 5 are, for example, each 3 mm. The protrusion u is measured here and hereinafter by the distance of the outer protruding edge of the planar electrode from the edge of the active layer 5 (the distance measured orthogonally to the portion of the side surface S where the planar electrode protrudes).

The first bus bar 8.1 is applied to the protruding area U' of the first planar electrode 6.1 and the second bus bar 8.2 is applied to the protruding area u″ of the second planar electrode 6.2. The bus bars 8.1, 8.2 are each applied to the surface of the planar electrodes 6.1, 6.2 facing the active layer 5. The protruding area U' of the first planar electrode 6.1 is offset by 90 ° with respect to the protruding area u″ of the second planar electrode 6.2. The bus bars 8.1, 8.2 are thus not arranged opposite each other, but are likewise offset from each other by 90 °. The bus bars 8.1, 8.2 are for example designed as silver-containing printing pastes having a layer thickness of 10 μm. The first planar electrode 6.1 and the third planar electrode 6.3 are electrically conductively connected to each other via a conductive bridge 7. The conductive bridge 7 is arranged in a hole-like cutout in the first segment 5.1 of the active layer 5 and is in direct spatial contact with the first planar electrode 6.1 and the third planar electrode 6.3, such that a voltage applied to the first planar electrode 6.1 is also applied to the third planar electrode 6.3 via the conductive bridge 7. The conductive bridge 7 may alternatively be arranged along the side surface S of the active layer 5 and touch the first planar electrode 6.1 and the third planar electrode 6.3 in an edge region (not shown here).

The first bus bar 8.1 and the second bus bar 8.2 are connected to a voltage source 10 via connection lines. The voltage source 10 is in turn connected to a control unit via which the voltage supplied to the functional element 4 can be set.

The planar electrodes 6.1, 6.2, 6.3 are each applied to a carrier film (carrier film not shown here) having substantially the same surface area as the particular planar electrode 6.1, 6.2, 6.3 applied. The carrier film is provided with an ITO coating facing the active layer 5 and having a thickness of about 100 nm, which forms the planar electrodes 6.1, 6.2, 6.3. The planar electrodes 6.1, 6.2, 6.3 are thus arranged between the carrier film and the active layer 5. The carrier film is not shown in the figures. The carrier film is composed of polyethylene terephthalate (PET), for example, and has a thickness of 0.125 mm, for example. The planar electrodes 6.1, 6.2, 6.3 are arranged between the respective carrier film and the active layer 5.

The active layer 5 comprises a polymer matrix having dispersed therein liquid crystals which align in dependence of the voltage applied to the planar electrodes 6.1, 6.2, 6.3, whereby the optical properties can be controlled. The second section 5.2 of the active layer 5 changes its optical state in dependence on the voltages applied to the first planar electrode 6.1 and the second planar electrode 6.2. The optical change is caused by a voltage difference between the second planar electrode 6.2 and the third planar electrode 6.3, which causes the liquid crystal in the second segment 5.2 to realign.

Fig. 4 and 5 show an embodiment of a laminate 100 according to the invention, wherein the functional element 4 is arranged within the laminate 100, as substantially described with respect to fig. 1 to 3. The laminated sheet 100 is designed as a windshield with an electrically controllable sun visor for a vehicle, and the functional element 4 is cut and bent (or bendable) according to the arrangement in the windshield. Fig. 4 shows a plan view of the inside of the laminated sheet 100 (i.e., the surface of the laminated sheet 100 disposed to face the inside of the vehicle). Fig. 5 shows a cross-sectional view of the laminate sheet 100 of fig. 4, wherein a section line X-X' is indicated in fig. 4.

The laminated sheet 100 includes an outer sheet 1 and an inner sheet 2, the outer sheet 1 and the inner sheet 2 being connected to each other via a thermoplastic interlayer 3. The outer sheet 1 has a thickness of 2.1mm and consists of, for example, transparent soda lime glass. The inner sheet 2 has a thickness of 1.6 mm and is also composed of, for example, transparent soda lime glass. The laminated sheet has an upper edge D facing the top in the installed position and a lower edge M facing the engine compartment in the installed position.

The outer sheet 1 has an inner side surface II facing the thermoplastic intermediate layer 3 and an outer surface I facing away from the thermoplastic intermediate layer 3. The outer surface I of the outer sheet 1 is also the outer surface of the laminated sheet 100. The inner sheet 2 has an outer surface III facing the thermoplastic intermediate layer 3. In addition, the inner sheet 2 has an inner side surface IV which faces away from the thermoplastic intermediate layer 3 and is also the inner side surface of the laminated sheet 100.

The thermoplastic intermediate layer 3 comprises a first thermoplastic laminate film 3.1, a second thermoplastic laminate film 3.2 and a third thermoplastic laminate film 3.3 stacked on top of each other in a planar manner arranged between the outer sheet 1 and the inner sheet 2, wherein the third thermoplastic laminate film 3.3 is arranged between the first thermoplastic laminate film 3.1 and the second thermoplastic laminate film 3.2. The laminated films 3.1, 3.2, 3.3 each have a thickness of, for example, 0.38 mm. The laminated films 3.1, 3.2, 3.3 consist, for example, of 78% by weight of polyvinyl butyral (PVB) and 22% by weight of 2,2' -ethylenedioxydiethyl bis (2-ethylhexanoate) as plasticizer.

Between the first thermoplastic laminate film 3.1 and the second thermoplastic laminate film 3.2 a functional element 4 is arranged, the functional element 4 being controllable in its optical properties by means of a voltage. For simplicity, the supply lines are not shown. The first thermoplastic layer 3.1 is connected to the outer sheet 1 and the second thermoplastic layer 3.2 is connected to the inner sheet 2. The third thermoplastic laminate film 3.3 in the middle has a cut-out into which the cut-out functional element 4 is inserted with a precise fit, i.e. flush on all sides of the active layer 5. The protrusions U', u″ of the first planar electrode 6.1 and the second planar electrode 6.2 may overlap with the third thermoplastic laminate film 3.3 (not shown here). The third thermoplastic laminate film 3.3 thus forms a kind of backing frame for the functional element 4, which functional element 4 is thus completely encapsulated and protected by the thermoplastic material.

The functional element 4 acts as a sun visor in the laminated sheet 100 designed as a windshield and is arranged in an area above the central field of view B (as defined in ECE-R43). The height of the sun visor is for example 21 cm.

The first laminate film 3.1 may have a colored region (not shown here) arranged between the functional element 4 and the outer sheet 1. The light transmittance of the windshield is thereby additionally reduced in the region of the functional element 4 (for example, 30% of the light transmittance in the colored region), and the milky appearance of the PDLC functional element 4 is reduced in the diffuse state. Thereby making the aesthetics of the windshield significantly more attractive.

As is usual for windshields, the laminated sheet 100 has a fully encircling peripheral covering print 11, the peripheral covering print 11 being formed from opaque enamel on the inner side surfaces II, IV of the outer sheet 1 and the inner sheet 2. The distance of the functional element 4 from the upper edge D and the side edges of the laminate 100 is smaller than the width of the overlay print 11, so that the side surfaces of the functional element 4 (except the side edges pointing towards the central field of view B) are hidden by the overlay print 11. Electrical connections (not shown) comprising the bus bars 8.1, 8.2 are also conveniently mounted in the area covering the print 11 and are thus hidden.

The functional element 4 has a barrier layer 9 on all side surfaces, which covers the entire peripheral side surface and peripheral edge area of the upper side of the functional element 4 (i.e. the surface facing the first thermoplastic laminate film 3.1). The upper side of the functional element 4 is also the second surface B of the active layer 5 which is covered by the third planar electrode 6.3 (see fig. 1 to 3). Preferably, the functional element 4 is also covered by the first planar electrode 6.1 or the second planar electrode 6.2 in an edge region of the underside (i.e. the surface facing the second thermoplastic laminate film 3.2) of the barrier layer 9 having no protruding regions U', u″ (not shown here). Underneath the functional element 4 is also the first surface a of the active layer 5, which is covered by the first planar electrode 6.1 and the second planar electrode 6.2 (see fig. 1 to 3). The term "peripheral side surface of the functional element 4" basically refers to the peripheral side surface S of the active layer 5, as shown in fig. 1 to 3.

The barrier layer 9 reduces or prevents diffusion of plasticizer into the active layer 5, which increases the service life of the functional element 4. The thickness (or in other words, the material thickness) of the barrier layer 9 is, for example, at least 50 nm. The barrier layer 9 is for example a silicone layer. The barrier layer may also be formed of a single layer of multiple layers.

Fig. 6 shows a plan view of a further embodiment of a laminated sheet 100 according to the invention. Fig. 7 shows a cross-sectional view of the laminate sheet 100 of fig. 6, wherein a section line X-X' is indicated in fig. 6. The laminate sheet 100 is designed as a top sheet for a vehicle. The functional element 4 is arranged between the outer sheet 1 and the inner sheet 2 within the thermoplastic intermediate layer 3. The functional element 4 is arranged between the first thermoplastic laminate film 3.1 and the second thermoplastic laminate film 3.2. The third thermoplastic laminate film 3.3 is arranged in a frame-shaped manner around the functional element 4. As is common for top sheets, the laminate 100 has a fully encircling peripheral overlay print 11, the peripheral overlay print 11 being formed of opaque enamel on the inner side surfaces II, IV of the outer and inner sheets 1, 2.

The functional element 4 can be controlled in its optical properties by means of a voltage. For simplicity, the supply lines are not shown. The functional element 4 is divided into a plurality of switchable regions 5.2, 5'. For more details, please refer to fig. 8. The peripheral edges of the functional element 4 are completely hidden by the cover print 11 comprising the bus bars 8.1, 8.2, 8'. The functional element 4 extends over substantially the entire surface of the laminate 100 (minus the peripheral edge area completely hidden by the overlay print 11). In other words, the functional element 4 extends over the entire viewing area of the laminate 100.

The functional element 4 has a barrier layer 9 on all side surfaces, which covers the entire peripheral side surface and peripheral edge area of the upper side of the functional element 4 (i.e. the surface facing the first thermoplastic laminate film 3.1). The upper side of the functional element 4 is also the second surface B of the active layer 5 which is covered by the third planar electrode 6.3 (see fig. 8). The functional element 4 does not have a barrier layer 9 on the underside (i.e. the surface facing the second thermoplastic laminate film 3.2) because the first planar electrode 6.1, the second planar electrode 6.2 and all further planar electrodes 6' have protruding areas U ', U ", U '" with respect to the active layer 5, whereby a protrusion is achieved along the entire peripheral edge of the active layer 5 and the application of the barrier layer 9 is no longer necessary (not shown here). Underneath the functional element 4 is also the first surface a of the active layer 5 covered by the first planar electrode 6.1 and the second planar electrode 6.2 (see fig. 8). The term "peripheral side surface of the functional element 4" basically refers to the peripheral side surface S of the active layer 5, as shown in fig. 8.

The outer sheet 1 and the inner sheet 2 are composed of soda lime glass which may be optionally colored. The outer sheet 1 has a thickness of, for example, 2.1 mm and the inner sheet 2 has a thickness of 1.6 mm. The thermoplastic laminate films 3.1, 3.2, 3.3, for example, each have a thickness of 0.38 mm and consist, for example, of 78% by weight of polyvinyl butyral (PVB) and 22% by weight of 2,2' -ethylenedioxydiethyl bis (2-ethylhexanoate) as plasticizer.

Fig. 8 shows the functional element 4 in a side view, the functional element 4 being part of the laminate 100 in the embodiment of fig. 6 and 7. The variant of the functional element 4 shown in fig. 8 corresponds substantially to the variant of fig. 1 to 3, so that only differences are discussed here and in other respects reference is made to the description with respect to fig. 1 to 3.

In contrast to the functional element 4 of fig. 1 to 3, a further planar electrode 6' is applied to the first surface a of the active layer 5 in addition to the first planar electrode 6.1 and the second planar electrode 6.2. A total of 5 planar electrodes 6.1, 6.2, 6', which are electrically insulated from each other, are applied to the first surface a of the active layer 5. The second planar electrode 6.2 and the further 3 planar electrodes 6' are arranged next to each other in strips on the active layer 5, so that in a planar view 4 substantially rectangular areas can be seen (see fig. 6). The planar electrodes 6.2, 6 'are arranged parallel to each other and next to each other, wherein the longer sides of the respective planar electrodes 6', 6.2 are opposite to each other. The planar electrodes 6.1, 6.2, 6' are separated from each other by insulated wires introduced, for example, by laser ablation. The insulated wire has a width of, for example, 50 μm.

In contrast to the functional element 4 of fig. 1 to 3, the active layer 5 is not divided into individual segments here, i.e. regions separated from one another by insulating regions. The entire active layer 5 is a continuous layer, however, due to the divided planar electrodes 6.1, 6.2, 6 'on the first surface a, the layer can still be divided into a first region 5.1, a second region 5.2 and 3 further regions 5'. In the second region 5.2 and the further region 5', different optical states can be activated by applying a voltage to the first and second planar electrodes 6.1, 6.2 and the further planar electrode 6' by means of the voltage source 10. The second region 5.2 and the further region 5 'can be switched independently of each other, whereby the active layer 5 can be in different optical states depending on the regions 5.2, 5'. The first region 5.1 of the active layer 5 is not switchable and is preferably hidden by the overlay print 11 when installed in the laminate 100.

The first planar electrode 6.1, the second planar electrode 6.2 and the further planar electrode 6 'are connected to the bus bars 8.1, 8.2, 8' (shown in fig. 8 only for the first planar electrode 6.1) in the areas U ', U ", U'" protruding relative to the active layer 5. The bus bars 8.1, 8.2, 8 'are applied to the surface of the particular planar electrode 6.1, 6.2, 6' facing the active layer 5. The bus bars 8.1, 8.2, 8' are in turn connected to a voltage source 10 by means of wires. The first planar electrode 6.1, the second planar electrode 6.2 and the further planar electrode 6' together protrude with respect to the active layer 5 along the entire peripheral side surface S (minus the linear insulation region). This protects the functional element 4 even better from plasticizers, for example from the PVB layer, which would impair the optical quality of the functional element 4.

List of reference numerals:

1. Outer sheet

2. Inner sheet

3. Thermoplastic interlayers

3.1 First thermoplastic laminate film of intermediate layer 3

3.2 Second thermoplastic laminate film of intermediate layer 3

3.3 Third thermoplastic laminate film of intermediate layer 3

4. Functional element

5. Active layer

5.1 First segment/first region of active layer 5

5.2 Second segment/second region of active layer 5

Additional segments/additional regions of the 5' active layer 5

6.1 First plane electrode

6.2 Second planar electrode

6.3 Third plane electrode

6' Further planar electrode

7. Bridge

8.1 First bus bar

8.2 Second bus bar

8' Further bus bar

9. Barrier layer

10. Voltage source

11. Cover printing material

100. Laminated sheet

I outer surface of outer sheet 1

II inner side surface of outer sheet 1

III the outer surface of the inner sheet 2

Inner side surface of inner sheet 2

A first surface of the active layer 5

Second surface of active layer 5

Peripheral side surface of S active layer 5

S' first portion of side surface S

Second portion of S '' side surface S

Protruding area of U' first planar electrode 6.1

Protruding area of the u″ second planar electrode 6.2

U' "protruding region of further planar electrode 6

X-X' section line

H center view of laminated sheet 100 as a windshield

The upper edge, top edge of the D laminate 100

The lower edge of the M laminate 100, the engine edge.

Claims

1. A laminated sheet (100) having electrically controllable optical properties, comprising:

an outer sheet (1), a thermoplastic intermediate layer (3), an inner sheet (2) and a functional element (4), the functional element (4) being arranged between the outer sheet (1) and the inner sheet (2) and having electrically controllable optical properties, wherein the functional element (4) comprises:

-an active layer (5) having a first surface (a), a second surface (B) and a peripheral side surface (S);

-a first planar electrode (6.1) extending over the first surface (a) in a first region (5.1) of the active layer (5);

-a second planar electrode (6.2) extending over the first surface (a) in a second region (5.2) of the active layer (5);

-a third planar electrode (6.3) extending over the second surface (B) at least in the first (5.1) and second (5.2) regions of the active layer (5), and

-A bridge (7) electrically connecting said first planar electrode (6.1) to said third planar electrode (6.3),

Wherein the first planar electrode (6.1) has a first protruding region (U ') with respect to the active layer (5) and the second planar electrode (6.2) has a second protruding region (U ") with respect to the active layer (5), and a first bus bar (8.1) is arranged at least on the first protruding region (U'), and a second bus bar (8.2) is arranged at least on the second protruding region (U"), and wherein the first planar electrode (6.1) and the second planar electrode (6.2) are electrically insulated from each other.

2. The laminated sheet (100) according to claim 1, wherein the active layer (5) has a first segment (5.1) in the first region and a second segment (5.2) in the second region.

3. The laminated sheet (100) according to claim 1 or 2, wherein the first protruding region (U') and the second protruding region (U ") together protrude beyond the active layer (5) along the entire peripheral side surface (S).

4. A laminated sheet (100) according to any one of claims 1 to 3, wherein the thermoplastic intermediate layer (3) comprises at least a first thermoplastic laminated film (3.1) and a second thermoplastic laminated film (3.2), and the functional element (4) is arranged between the first thermoplastic laminated film (3.1) and the second thermoplastic laminated film (3.2).

5. The laminate sheet (100) according to claim 4, wherein the thermoplastic intermediate layer (3) has a third frame-like thermoplastic laminate film (3.3) arranged peripherally around the functional element (4).

6. The laminate sheet (100) according to any one of claims 1 to 5, wherein the active layer (5) is sealed with at least one barrier layer (9) on at least one portion (S', S ") of the peripheral side surface (S), preferably on all portions of the peripheral side surface (S).

7. The laminated sheet (100) according to any one of claims 1 to 6, wherein the functional element (4) is a PDLC functional element.

8. The laminated sheet (100) according to any one of claims 1 to 7, wherein the second region (5.2) is at least 5 times, particularly preferably at least 10 times larger than the first region (5.1) in terms of its surface area.

9. The laminate sheet (100) according to any one of claims 1 to 8, wherein the first planar electrode (6.1) and/or the second planar electrode (6.2) protrude with respect to the active layer (5) by at least 1 mm, preferably by at least 5mm.

10. The laminate sheet (100) according to any one of claims 1 to 9, wherein the first bus bar (8.1) is conductively connected to the first planar electrode (6.1) by means of a conductive material, preferably a silver-containing material.

11. A vitrification unit comprising a laminated sheet (100) according to any one of claims 1 to 10, wherein the first bus bar (8.1) and the second bus bar (8.2) are connected to a voltage source (10) and are capable of activating different optical states of the second region (5.2) by means of a voltage change.

12. A method for producing a laminate sheet (100) according to any one of claims 1 to 10, wherein,

A) The first bus bar (8.1) is connected to the first planar electrode (6.1) of the functional element (4), and the second bus bar (8.2) is connected to the second planar electrode (6.2) of the functional element (4), and

B) The functional element (4) is arranged together with the outer sheet (1), the inner sheet (2) and the thermoplastic intermediate layer (3) to form a layer stack, and the layer stack is subsequently laminated to form a laminated sheet (100).

13. Method according to claim 12, wherein the division of the active layer (5) into the first segment (5.1) and the second segment (5.2) is carried out by means of segments by laser irradiation.

14. Use of a laminate sheet (100) according to any one of claims 1 to 10 as a windscreen or roof sheet for a vehicle.

15. Use according to claim 14, wherein the electrically controllable functional element (4) is used as a sun visor in a windscreen or roof sheet of a vehicle.