KR20200110704A - Method for manufacturing composite pane glass containing functional elements having electrically controllable optical properties - Google Patents

Abstract

The present invention relates to a method for manufacturing a composite pane 100 having a functional element 5 having electrically controllable optical properties, at least
a) the first barrier film 4a and the first intermediate layer 3a and/or the second barrier film 4b and the second intermediate layer 3b are fixedly bonded to each other temporarily or permanently,
b) Outer pane (1), first intermediate layer (3a), first barrier film (4a), functional element (5) having electrically controllable optical properties, second barrier film (4b), second intermediate layer (3b) ) And the inner pane 2 are arranged on top of each other in this spatial order, and
c) The stack sequence is laminated together.

Description

Method for manufacturing composite pane glass containing functional elements having electrically controllable optical properties

The present invention relates to a method of manufacturing a composite pane comprising a functional element having electrically controllable optical properties, and more particularly to a windshield having an electrically controllable sun visor.

In the automotive and construction sectors, composite panes with electrically controllable functional elements are often used as sunscreens or privacy screens. Thus, for example, a windshield in which a sun visor is integrated is known in the form of a functional element in which the sun visor has an electrically controllable optical property. In particular, the transmittance behavior or scattering behavior of electromagnetic radiation in the visible range can be electrically controlled. The functional elements are generally film-like and laminated or bonded to a composite pane. In the case of the windshield, the driver can control the transmittance behavior of the pane itself to sunlight. Therefore, the conventional mechanical sun visor is unnecessary. As a result, the weight of the vehicle can be reduced, and space can be secured in the ceiling area. In addition, electrical control of the sun visor is more convenient than manually folding the mechanical sun visor. Windshields with such an electrically controllable sun visor are known, for example, from DE 102013001334 A1, DE 102005049081 B3, DE 102005007427 A1 and DE 102007027296 A1.

A typical electrically controllable functional element contains an electrochromic layer structure or a single particle device (SPD) film. An additional possible functional element for realizing an electrically controllable sunscreen is a so-called PDLC functional element (polymer dispersed liquid crystal). Their active layer contains liquid crystals embedded in a polymer matrix. When no voltage is applied, the liquid crystals are randomly aligned, resulting in strong scattering of light passing through the active layer. When voltage is applied to the surface electrode, the liquid crystals are aligned in a common direction, and the transmittance of light passing through the active layer is increased. The PDLC functional factor works less by reducing the total transmittance, but instead works by increasing the scatter to ensure protection against glare.

In the prior art, stacked functional elements, especially PDLC functional elements, often present undesirable aging phenomena, such as changes in brightness and shade, in the edge regions. This is improved by sealing the entrance edge of the functional element with a barrier material, for example as disclosed in WO 2014/086555 A1.

It is an object of the present invention to provide an improved method for manufacturing a composite plate glass including a functional element having an electrically controllable optical property that is easy to process, is easy to automate, and has high aging resistance at the same time.

The object of the present invention is achieved by a method of manufacturing a composite pane according to independent claim 1. One preferred embodiment emerges from the dependent claims.

The present invention includes a method of manufacturing a composite pane comprising functional elements having electrically controllable optical properties, wherein at least

a) -A first barrier film and a first intermediate layer,

-Second barrier film and second intermediate layer

or

-In each case all

Fixedly bonded to each other,

b) a stack sequence is prepared, where

-Outer pane (1),

-A first intermediate layer 3a,

-A first barrier film 4a,

-Functional elements (5) with electrically controllable optical properties,

-A second barrier film 4b,

-A second intermediate layer 3b, and

-Inner panes (2) are placed on top of each other,

And

c) The stack sequence is laminated together.

The bonding between the barrier film and the intermediate layer can be permanent or temporary, ie at least until the stack sequence has been placed in step b).

This has the special advantage that it prevents slipping of the barrier film during lamination as well as during storage, transportation and assembly, and that the barrier film is fixedly and properly bonded to the functional elements. As a result, among other things, air inclusion between the barrier film and the functional element is prevented and the optical quality of such a composite pane is particularly high.

The list of elements in a stack sequence represents a spatial sequence in which elements are placed on top of each other. The elements are designed to be substantially flat and consist of a thin layer or sheet with wide lateral extensions. Of course, the large surfaces of each element are arranged parallel to each other.

The indication of the sequence does not limit the temporal sequence. That is, in the manufacture of the stack sequence it is possible to start with, for example, an inner pane or an outer pane. Also, subgroups can be created prior to full assembly of the stack sequence.

In an advantageous embodiment of the method according to the invention, in step c), an intermediate layer with built-in functional elements is formed from the first intermediate layer and the second intermediate layer by lamination. The barrier film is dimensioned and positioned to seal the lateral edge of the functional element.

Lamination is preferably carried out under the action of heat, vacuum and/or pressure. Known methods for lamination may be used, for example an autoclave method, a vacuum bag method, a vacuum ring method, a calender method, a vacuum laminator or a combination thereof.

Electrical contact of the surface electrodes of the functional elements is preferably carried out prior to lamination of the composite pane. Any prints that exist, for example opaque masking prints or printed busbars for electrical contact of functional elements, are also preferably applied prior to lamination, preferably by screen printing.

In another advantageous embodiment of the method according to the invention, the first barrier film and the second barrier film are disposed on each other substantially simultaneously.

In another advantageous embodiment of the method according to the invention, the barrier film is arranged with overhangs u on all sides beyond the functional element, the functional element being at least partially and preferably completely covered by the barrier film.

In another advantageous embodiment of the method according to the invention, the barrier films are arranged frame-like along the lateral edge of the functional element. Advantageously, they have two overhangs on either side of the lateral edge of the functional element.

In another advantageous embodiment of the method according to the invention, the first and/or second barrier film is applied to each first or second intermediate layer by means of an adhesive bond, preferably an acrylic adhesive, particularly preferably an acrylate adhesive. Bonded, and in particular by adhesives containing at least 50% methyl methacrylate.

Alternatively or in combination, the barrier film is by means of a fusion bond, for example by local or regional heating, preferably by heating to a temperature higher than the melting temperature of the barrier film and/or interlayer. Can be bonded to the middle layer.

Alternatively or in combination, the barrier film can be connected to the intermediate layer by a press bond, for example a pressing method, or by a combination of friction and pressing, for example by ultrasonic bonding.

Adhesive bonds, fusion bonds and press bonds are generally permanent. Thus, all pre-laminations are permanently fixed, suitable for long-term storage, and can be easily prepared.

In another advantageous embodiment of the method according to the invention, the barrier film and each intermediate layer are bonded to each other by a solvent, preferably by an organic solvent, particularly preferably by means of acetone, alcohol, in particular ethanol, isopropanol or chloroform. do. The solvent is advantageously sprayed onto the barrier film and/or the intermediate layer or is applied in other ways, for example by means of a brush or by means of an impregnating roller.

The solvent may volatilize in step b) and/or during step c), before and/or after placement of the stack sequence. Such a solvent can locally dissolve and bond together the surface of the barrier film and/or intermediate layer. Alternatively or in combination, the solvent may temporarily bond the stack sequence and the surface of the intermediate layer to each other by cohesive force.

The advantage of this method lies in the fact that the solvent is no longer present in the subsequent product and/or the optical properties and, in particular, does not adversely affect the transmittance.

The invention further comprises a composite pane produced by the method according to the invention comprising at least:

-A stack sequence consisting of an outer pane, a first interlayer, a second interlayer and an inner pane, wherein the interlayer contains in each case at least one thermoplastic polymer film together with at least one plasticizer,

-A functional element having electrically controllable optical properties is at least partially disposed between the first intermediate layer and the second intermediate layer,

Here the at least one barrier film is disposed not only between the first intermediate layer and the functional element, but also between the functional element and the second intermediate layer, and the barrier film has an overhang u at least partially beyond the functional element.

Preferably, the barrier film is arranged in each case between the functional element and the second intermediate layer as well as between the first intermediate layer and the functional element, wherein each barrier film has an overhang u at least partially beyond the functional element. The overhang sections of the barrier film are disposed directly adjacent to each other and contact each other.

The composite pane can be, for example, a windshield or ceiling panel of a vehicle or other vehicle glazing, for example a split pane of a vehicle, preferably a railroad car or bus. Alternatively, the composite pane can be, for example, architectural glass on the exterior facade of a building or a split pane inside the building.

The terms "outer pane" and "inner pane" arbitrarily describe two different windows. In particular, the outer pane may be referred to as a “first window” and the inner pane may be referred to as a “second window”.

When a composite pane is provided for separating the interior from the external environment, in a window opening of a vehicle or of a building, "inner pane" refers to panes (second pane) facing the interior (inside the vehicle) in this context of the invention. Refers to. "Outer pane" refers to pane facing the external environment (first pane). However, the present invention is not limited thereto.

The composite pane according to the invention comprises a functional element having electrically controllable optical properties arranged at least partially between a first intermediate layer and a second intermediate layer. The first and second interlayers typically have the same dimensions as the outer pane and the inner pane. The functional element is preferably film-like.

In an advantageous embodiment of the composite pane according to the invention, at least one barrier film is arranged in each case between the first intermediate layer and the second intermediate layer, which barrier film comprises one side edge of the functional element, two of the functional element. It has an overhang (u) beyond the functional element at the side edge, at the three side edges of the functional element or at all side edges (ie at least four side edges of the functional element). This means that one barrier film is placed on the bottom surface of the functional element and the other barrier film is placed on the top surface of the functional element. In the overhang (u) region, the overhang region of one barrier film directly contacts the overhang region of the second barrier film. In the context of a film-like functional element, "bottom surface" and "top surface" mean the outer pane and two large surfaces arranged parallel to the inner pane, namely the outer and inner surfaces of the functional element. The term "side edge" describes the surface of a very thin, orthogonal functional element in a film-like functional element. The barrier film may only partially or completely cover the upper and/or lower surfaces of the functional element.

In an advantageous embodiment of the composite pane according to the invention, the overhang (u) of the barrier film beyond the functional element is at least 0.5 mm, preferably at least 2 mm, particularly preferably at least 5 mm, and in particular at least 10 mm. The overhang (u) is thus determined as a lateral dimension parallel to the two largest dimensions of the functional element or of the composite pane.

In an advantageous embodiment of the composite pane according to the invention, the overhang (u) of the barrier film beyond the functional element is less than 50 mm, preferably less than 30 mm and particularly preferably less than 20 mm.

In another advantageous embodiment of the composite pane according to the invention, the barrier film or the various regions of the barrier film are bonded to each other in the overhang region, preferably pressed together (eg, by lamination in the composite pane). As a result, a sufficient and safe diffusion barrier for the plasticizer outside the intermediate layer is produced, and blurring of the edge regions of the functional elements is reduced or prevented.

The invention further comprises a composite pane produced by the method according to the invention,

-Wherein the intermediate layers contain at least one thermoplastic polymer film with at least one plasticizer,

-The barrier film is implemented to prevent the plasticizer from spreading through the barrier film.

The present invention is based on the inventors' perception that the diffusion of plasticizers from the intermediate layer into the interior of the functional element during aging brightens or changes the transmittance, thereby impairing the through-vision and aesthetics of the composite pane. As a result of sealing the functional element from the intermediate layer to the functional element, in particular with a barrier film that retards or prevents diffusion of the plasticizer to the lateral edges of the functional element, such aging phenomena are greatly reduced or completely prevented.

The sealing in the area of the lateral edge of the functional element is carried out by means of two barrier films placed directly adjacent to each other, making area contact with each other, and being pressed against each other (e.g., to lamination in the interior of the composite pane. due to). As a result of embedding and lamination, the barrier films are fixedly bonded to each other in the overhang (u) region after the lamination process.

In an advantageous embodiment of the composite pane according to the invention, the intermediate layer contains a polymer, preferably a thermoplastic polymer. In a particularly advantageous embodiment of the composite pane according to the invention, the intermediate layer is at least 3% by weight, preferably at least 5% by weight, particularly preferably at least 20% by weight, even more preferably at least 30% by weight, and in particular at least It contains 40% by weight of plasticizer. Preferably, the plasticizer contains or consists of triethylene glycol-bis-(2-ethyl hexanoate).

Plasticizers are chemicals that make plastics softer, softer, smoother, and more elastic. The thermoelastic range of the plastic is shifted to a lower temperature so that the plastic has the desired higher elastic properties over the service temperature range. Other preferred plasticizers are carboxylic acid esters, in particular low volatility carboxylic acid esters, fats, oils, soft resins and camphors. The other plasticizer is preferably an aliphatic diester of triethylene glycol or tetraethylene glycol. Particularly preferably used as plasticizers are 3G7, 3G8 or 4G7, wherein the first number represents the number of ethylene glycol units and the last number represents the number of carbon atoms in the carboxylic acid portion of the compound. Thus, 3G8 is triethylene glycol-bis-(2-ethyl hexanoate), that is, the formula C ₄ H ₉ CH(CH ₂ CH ₃ )CO(OCH ₂ CH ₂ ) ₃ O ₂ CCH(CH ₂ CH ₃ )C It denotes a compound of ₄ H _9.

In another particularly advantageous embodiment of the composite pane according to the invention, the intermediate layer comprises at least 60% by weight, preferably at least 70% by weight, particularly preferably at least 90% by weight, and in particular at least 97% by weight polyvinyl butyral. Contains.

The thickness of each intermediate layer is preferably 0.2 mm to 2 mm, particularly preferably 0.3 mm to 1 mm, in particular 0.3 mm to 0.5 mm, for example 0.38 mm.

In an advantageous embodiment of the composite pane according to the present invention, the barrier film is implemented to prevent diffusion of the plasticizer from the intermediate layer through the barrier film.

In a particularly advantageous embodiment of the composite pane according to the invention, the barrier film has a low plasticizer, preferably a plasticizer content of less than 3% by weight, particularly preferably less than 1% by weight, and in particular less than 0.5% by weight. Most particularly preferably, the barrier film is plasticizer-free, i.e. no plasticizer is intentionally added. The barrier film contains or is made of a polymer, preferably polyethylene terephthalate (PET) or polyvinyl fluoride (PVF) or polyethylene (PE). The barrier film may also contain a low plasticizer polyvinyl butyral (PVB) having a plasticizer content of less than 3% by weight.

The controllable functional element typically comprises an active layer between two surface electrodes. The active layer has controllable optical properties that can be controlled through a voltage applied to the surface electrode. The surface electrode and the active layer are typically disposed substantially parallel to the surfaces of the outer pane and the inner pane. The surface electrode is electrically connected to an external voltage source in a manner known per se. Electrical contact is made to a suitable connection cable, for example a foil conductor, which is selectively connected to the surface electrode via so-called bus bars, for example strips of electrically conductive material or electrically conductive imprints. Realized by

The surface electrode is preferably designed as a transparent electrically conductive layer. The surface electrode preferably contains at least a metal, a metal alloy or a transparent conductive oxide (TCO). The surface electrode may contain, for example, silver, gold, copper, nickel, chromium, tungsten, indium tin oxide (ITO), gallium doped or aluminum doped zinc oxide, and/or fluorine doped or antimony doped tin oxide. The surface electrode preferably has a thickness of 10 nm to 2 μm, particularly preferably 20 nm to 1 μm, and most particularly preferably 30 nm to 500 nm.

In addition to the active layer and the surface electrode, the functional element may have other layers known per se, for example a barrier layer, a blocking layer, an antireflection layer, a protective layer and/or a smoothing layer.

The functional element is preferably present as a multilayer film with two outer carrier films. In this multilayer film, the surface electrode and the active layer are disposed between two carrier films. Here, "outer carrier film" means a carrier film forming two surfaces of a multilayer film. Thus, the functional element can be provided as a laminated film which can be advantageously processed. The functional elements are advantageously protected from damage, in particular corrosion, by the carrier film. The multilayer film comprises, in the order indicated, at least one carrier film, one surface electrode, one active layer, another surface electrode and another carrier film. Carrier films in particular carry surface electrodes and provide the necessary mechanical stability for liquid or soft active layers.

The carrier film preferably contains at least one thermoplastic polymer, particularly preferably a low-cost or non-plasticizer polyethylene terephthalate (PET). This is particularly advantageous in terms of the stability of the multilayer film. However, the carrier film can also be used with other polymers that are low-cost or plasticizer-free, such as ethylene vinyl acetate (EVA), polypropylene, polycarbonate, polymethyl methacrylate, polyacrylate, polyvinylchloride, polyacetate resin, casting. Resins, acrylates, fluorinated ethylene propylene, polyvinyl fluoride and/or ethylene-tetrafluoroethylene. The thickness of each carrier film is preferably 0.4 mm to 1 mm, particularly preferably 0.1 mm to 0.2 mm.

Typically, the carrier film has an electrically conductive coating facing the active layer in each case and acting as a surface electrode.

In another advantageous embodiment of the composite pane according to the invention, the functional element is a polymer dispersed liquid crystal (PDLC) functional element. The active layer of the PDLC functional element contains a liquid crystal embedded in a polymer matrix. When no voltage is applied to the surface electrode, the liquid crystal is randomly oriented, and light passing through the active layer is strongly scattered. When a voltage is applied to the surface electrode, the liquid crystals are aligned in a common direction, thereby increasing the transmittance of light passing through the active layer.

However, in principle it is also possible to use other types of controllable functional elements, for example electrochromic functional elements or suspended particle device (SPD) functional elements. The mentioned controllable functional elements and their modes of operation are known per se to a person skilled in the art so that a detailed description may be omitted here.

Functional elements such as multilayer films are commercially available. The functional elements to be incorporated are typically further cut into the desired shape and size in multilayer films of large dimensions. This can be done mechanically, for example by means of a knife. In an advantageous embodiment, the cutting is carried out using a laser. In this case, it has been proven that the side edges are more stable than machine cutting. With the use of mechanically cut side edges, there is a risk that the material is pulled back and is visually noticeable and adversely affects the aesthetics of the pane.

The functional elements are bonded to the outer pane through the region of the first intermediate layer and to the inner pane through the region of the second intermediate layer (as well as, if possible, also via a barrier film disposed therebetween in each case). The intermediate layers are preferably arranged in an area on top of each other with a functional element inserted between the two layers, and are stacked on each other. The area of the intermediate layer overlapping the functional element forms the area connecting the functional element to the pane. In different areas of the pane where the interlayers are in direct contact with each other, the two original layers may be fused during lamination so that there is no longer a discernible and instead one uniform interlayer.

For example, the intermediate layer can be formed by a single thermoplastic film. The interlayer can also be formed as a two-ply, three-ply or multi-ply film stack, wherein the individual films have the same or different properties. The interlayer may also be formed from sections of different thermoplastic films with adjacent side edges.

In an advantageous embodiment of the composite pane according to the invention, the area of the first or second intermediate layer in which the functional element is bonded to the outer pane or to the inner pane is tinted or colored. Therefore, the transmittance of this region in the visible spectrum range is reduced compared to the uncolored layer or the achromatic layer. Thus, the colored/colored area of the intermediate layer reduces the transmittance of the windshield in the sun visor area. Since coloring creates a more neutral appearance, the aesthetic impression of the functional elements is particularly enhanced, bringing a more pleasant effect to the observer.

In this context of the present invention, "electrically controllable optical property" means an infinitely controllable property as well as a property that can be switched between two or more discrete states.

Electrical control of the sun visor is carried out, for example, using switches, rotary knobs or sliders integrated in the vehicle dashboard. However, the switch area for controlling the sun visor can be integrated in the windshield, for example in the capacitive switch area. Alternatively or additionally, the sun visor can be controlled in a non-contact manner, for example by sensing a gesture, or as a function of the pupil or eyelid condition detected by the camera and appropriate evaluation electronics. Alternatively or additionally, the sun visor can be controlled by a sensor that detects incident light on the pane.

The colored or colored region of the intermediate layer preferably has a transmittance of 10% to 50%, particularly preferably 20% to 40% in the visible spectral range. In this way, particularly good results can be achieved in terms of anti-glare and visual appearance.

The intermediate layer can be formed by a single thermoplastic film, and the colored or colored areas are produced by local coloring or coloring. Such films can be obtained, for example, by coextrusion. Alternatively, uncolored film sections and colored or colored film sections may be combined to form a thermoplastic layer.

The colored or colored area may be uniformly colored or colored. That is, it may have a location-independent transmittance. However, coloring or coloring may be non-uniform, and in particular, a gradual change in transmittance (transmittance progression) may be realized. In one embodiment, the transmittance level decreases in the at least partially colored or colored area as the distance from the top edge increases. Thus, it is possible to avoid the sharp edge of the colored or colored area, so that the transition from the sun visor to the transparent area of the windshield appears gradually, which looks more aesthetically appealing.

In an advantageous embodiment, the area of the first intermediate layer, ie the area between the functional element and the outer pane, is colored. This gives a particularly aesthetic look when the outer pane is viewed from above. The area of the second intermediate layer between the functional element and the inner pane can, optionally, be additionally colored or colored.

Composite panes with electrically controllable functional elements can advantageously be embodied as a windshield with an electrically controllable sun visor. Such a windshield has an upper edge and a lower edge as well as two side edges extending between the upper and lower edges. "Top edge" refers to an edge intended to point upwards in the installation position. "Lower edge" refers to the edge pointing down in the installation position. The upper edge is often referred to as the “ceiling edge” and the lower edge is often referred to as the “engine edge”.

The windshield has a central field of view, and high demands are placed on optical quality. The central field of view should have a high light transmittance (typically more than 70%). The central field of view is specifically referred to as field of view B, field of view B, or area B to those of ordinary skill in the art. Sight B and its technical requirements are regulated by Regulation No. of the European Comm ission for Europe of the United Nations (UN/ECE). 43 (ECE-R43, "Unified provisions for approval of safety glazing materials and installation of them in vehicles"). There, sight B is defined in Appendix 18.

The functional element is advantageously arranged above the central field of view (field of view B). This means that the functional element is placed in the area between the central field of view and the upper edge of the windshield. The functional element does not have to cover the entire area, but is completely located within this area and does not protrude into the central field of view. That is, the functional element falls less off the upper edge of the windshield than the central field of view. Therefore, the transmittance of the central field of view is not adversely affected by the functional elements located in a position similar to that of the conventional mechanical sun visor in the folded state.

The windshield is preferably provided for automobiles, particularly preferably for passenger cars.

In a preferred embodiment, the functional element, more precisely the side edges of the functional element, are circumferentially surrounded by a third intermediate layer. The third intermediate layer is designed like a frame with a recess. The functional element can be inserted into the recess or placed in a plane above or below it. The third intermediate layer can also be formed by a thermoplastic film in which the recess is introduced by cutting. Alternatively, the third intermediate layer may consist of a number of film sections around the functional element. The intermediate layer is preferably formed of a total of three or more thermoplastic layers arranged in surface contact on each other, the middle layer of which has a recess in which the functional elements are arranged. In the manufacturing process, the third intermediate layer is arranged between the first intermediate layer and the second intermediate layer, and the side edges of all intermediate layers are preferably arranged coincidently. The third intermediate layer preferably has approximately the same thickness as the functional element. Thus, local differences in windshield thickness introduced by locally limited functional elements can be compensated so that glass breakage during lamination and/or permanent stress of the glass can be prevented.

The side edges of the functional element visible when viewed through the windshield are preferably arranged flush with the third intermediate layer so that there is no gap between the side edges of the functional element and the associated side edges of the intermediate layer. This is particularly the case for the lower edge of the functional element, which is usually visible. Thus, the boundary between the third intermediate layer and the functional element is visually less noticeable.

In one preferred embodiment, the functional element and the lower edge of the colored area of the intermediate layer(s) are adapted to the shape of the upper edge of the windshield to provide a more attractive visual impression. Since the upper edge of the windshield is usually curved, in particular concavely curved, the lower edge of the functional element and the colored area is also preferably curved. Particularly preferably, the lower edge of the functional element is substantially parallel to the upper edge of the windshield. However, it is also possible to construct a sun visor from two halves where each straight line is arranged at an angle to each other and forms a substantially V-shaped upper edge.

In one embodiment of the invention, the functional element is divided into segments by isolation lines. Isolation lines are specifically introduced into the surface electrode so that the segments of the surface electrode are electrically isolated from each other. The individual segments are connected to the voltage source independently of each other so that they can be operated individually. Thus, different areas of the sun visor can be switched independently. Particularly preferably, the isolation lines and segments are arranged horizontally in the installation position. Therefore, the height of the sun visor can be controlled by the user. The term “horizontal” should be interpreted broadly herein and refers to the direction of extension from the windshield to the side edges of the windshield. The isolation lines need not necessarily be straight, but may be slightly curved, and can preferably be adjusted to be substantially parallel to the possible curvature of the upper edge of the windshield, in particular to the upper edge of the windshield. Of course, vertical isolation lines can also be conceived.

Isolation lines are, for example, 5μm to 500μm wide, especially 20μm to 200μm. The width of the segment, i.e. the distance between adjacent isolation lines, can be appropriately selected by a person skilled in the art according to the requirements of the individual case. Isolation lines can be introduced by laser ablation, mechanical cutting or etching during the production of the functional element. Multilayer films that have already been laminated may be divided by laser ablation.

The top and side edges or all side edges of the functional element are preferably hidden from view by means of an opaque masking print, or through the composite pane by an outer frame. Windshields typically have a circumferential masking print made of opaque enamel, which in particular serves to visually hide the adhesive used in window installations and to protect against UV radiation. This peripheral masking print is preferably used to conceal the upper and side edges of the functional element as well as the necessary electrical connections. After that, the sun visor is advantageously integrated into the exterior of the windshield and only its lower edge can potentially be identified by an observer. Preferably, the outer pane and also the inner pane have a masking print to prevent see-through on both sides.

The functional element may also have recesses or holes, for example in the so-called sensor window or camera window area. Sensors or cameras are mounted in these areas, their function being degraded by control elements in the beam path, for example rain sensors. It is also possible to implement a sun visor having at least two separate functional elements by providing a space for a sensor window or a camera window by providing a distance between the functional elements.

The functional element (or all of the functional elements in the case of the aforementioned plurality of functional elements) spans the entire width of the composite pane or windshield, excluding edge areas on both sides, for example 2 mm to 20 mm wide. It is preferably arranged. The functional element also preferably has a distance of 2 mm to 20 mm, for example from the upper edge. The functional elements are thus sealed in the interlayer and protected from corrosion and contact with the surrounding atmosphere.

As is common in the case of window panes, the outer pane and the inner pane are preferably made of glass, particularly preferably of soda lime glass. However, panes can also be made of other types of glass, for example quartz glass, borosilicate glass or aluminosilicate glass or hard transparent plastics, for example polycarbonate or polymethyl methacrylate. The window can be transparent, colored or colored. The windshield must have adequate light transmittance in the central field of view and must have at least 70% in the primary perspective area A according to ECE-R43.

The outer pane, inner pane and/or interlayer may have known additional suitable coatings, such as antireflective coatings, non-stick coatings, anti-scratch coatings, photocatalytic coatings, or sun protection coatings or low-E coatings. have.

The thickness of the outer pane and the inner pane can vary widely and can therefore be adapted to the requirements of the individual case. The outer pane and the inner pane preferably have a thickness of 0.5 mm to 5 mm, particularly preferably 1 mm to 3 mm.

The present invention further comprises using the composite pane according to the present invention having an electrically controllable functional element as an interior glazing or an exterior glazing of a vehicle or building, wherein the electrically controllable functional element is used as a sunscreen or a privacy screen do.

The invention further comprises the use of the composite pane according to the invention as a vehicle windshield or ceiling panel, wherein the electrically controllable functional element is used as a sun visor.

A particular advantage of the present invention using a composite pane as a windshield is that a mechanically foldable sun visor mounted on a conventional vehicle ceiling can be omitted. Consequently, the invention also includes vehicles, preferably automobiles, in particular passenger cars, without such conventional sun visors.

The invention also includes the use of colored or colored regions of the intermediate layer for combining functional elements with electrically controllable optical properties with the outer pane or inner pane of the windshield, wherein the electrically controllable sun visor comprises the intermediate layer and the functional It is realized by colored or colored areas of the element.

The invention is described in detail with reference to the drawings and exemplary embodiments. The drawings are schematic representations and do not fit the actual size. The drawings in no way limit the invention.
1A is a plan view of a first embodiment of a composite pane according to the present invention.
Figure 1b is a schematic diagram of a method according to the invention for producing a composite pane according to the invention according to Figure 1a.
1C is a cross-sectional view through the composite pane of FIG. 1A along the line XX'.
1D is an enlarged view of region Z of FIG. 1B.
2A is a plan view of a second embodiment of a composite pane according to the present invention.
Figure 2b is a schematic diagram of a method according to the invention for producing a composite pane according to the invention according to Figure 2a.
2C is a cross-sectional view through the composite pane of FIG. 2A taken along the line XX'.
FIG. 2D is an enlarged view of region Z of FIG. 2B.
3A is a plan view of another embodiment of a composite pane according to the invention as a windshield with a sun visor.
3B is a cross-sectional view through the composite pane of FIG. 3A taken along the line XX'.
3C is an enlarged view of region Z of FIG. 3B.
4 is a plan view of another embodiment of a composite pane according to the invention as a windshield with a sun visor.
5A is a cross-sectional view through the alternative composite pane of FIG. 1A along section XX'.
Fig. 5b is a schematic diagram of a method according to the invention for producing a composite pane according to the invention according to Fig. 5a;
6 shows an embodiment of a method according to the invention with reference to a flow chart.

1A, 1C and 1D depict details of a composite pane 100 according to the invention in each case. 1B is a schematic diagram of a method according to the invention for manufacturing a composite pane 100 according to the invention depicted in FIGS. 1A, 1C and 1D.

The composite pane 100 includes an outer pane 1 and an inner pane 2 that are connected to each other through a first interlayer 3a and a second interlayer 3b. The outer pane 1 has a thickness of 2.1 mm and is made of transparent soda lime glass, for example. The inner pane 2 has a thickness of 1.6 mm and is made, for example, of transparent soda-lime glass. The composite pane 100 has a first edge referred to hereinafter as “top edge” and referred to as D. The composite pane 100 is hereinafter referred to as "lower edge" and is disposed opposite the upper edge D and has a second edge referred to as M. Composite pane 100 may be disposed as architectural glazing in the frame of a window together with other panes to form an insulating glazing, for example.

A functional element 5 capable of controlling the optical properties via voltage is disposed between the first intermediate layer 3a and the second intermediate layer 3b. For simplicity, electrical leads are not indicated. The controllable functional element 5 is, for example, a PDLC multilayer film consisting of two surface electrodes 12, 13 and an active layer 11 between two carrier films 14, 15. The active layer 11 includes a polymer matrix in which liquid crystals aligned as a function of a voltage applied to the surface electrodes are dispersed therein, and optical properties can be controlled through this. The carrier films 14, 15 are made of PET and have a thickness of 0.125 mm, for example. Carrier films 14 and 15 are provided with an ITO coating facing the active layer 11, having a thickness of about 100 nm, and forming the surface electrodes 12 and 13. The surface electrodes 12, 13 may be connected to the vehicle's electrical system via a busbar (not shown) (formed by, for example, a silver-containing screen print) and a connection cable (not shown).

The intermediate layers 3a and 3b comprise a thermoplastic film having a thickness of 0.38 mm in each case. Intermediate layers 3a, 3b are, for example, 78% by weight of polyvinyl butyral (PVB) and 20% by weight of triethylene glycol bis (2-ethyl hexanoate) (triethylene glycol bis(2)) as plasticizers. -ethyl hexanoate)).

The first barrier film 4a is disposed between the first intermediate layer 3a and the functional element 5. Further, the second barrier film 4b is disposed between the functional element 5 and the second intermediate layer 3b. The barrier films 4a, 4b here have an overhang u of 5 mm, for example beyond the functional element 5, for example on all sides. Here, "on all sides" means that there is an overhang (u) at each side edge (5.1, 5.2, 5.3, 5.4) of the functional element 5. In the overhang area, portions of the barrier film 4a contact portions directly opposite to the barrier film 4b. By the overlap of all sides, the functional element 5 is completely surrounded and sealed by the barrier films 4a, 4b.

The barrier films 4a, 4b are here made, for example, of substantially PET, ie up to at least 97% by weight. The barrier films 4a, 4b contain less than 0.5% by weight of plasticizer and prevent the diffusion of the plasticizer from the intermediate layers 3a, 3b on the side edges 5.1, 5.2, 5.3, 5.4 to the functional layer 5 It is suitable for reducing or preventing.

In the aging test, since diffusion of the plasticizer from the intermediate layers 3a, 3b to the functional element 5 and consequently deterioration of the functional element 5 is prevented, such a composite pane 100 is It shows a markedly reduced brightening in the area.

1b shows a schematic diagram of a method according to the invention for manufacturing the composite pane 100 of FIGS. 1a, 1c and 1d.

According to this, in the first step a), the first barrier layer 4a is disposed on the first intermediate layer 3a and is permanently bonded thereto, for example via a first adhesive bond 7a. In addition, the second barrier layer 4b is disposed on the second intermediate layer 3b, and is permanently bonded thereto through, for example, a second adhesive bond 7b. The adhesive bonds 7a, 7b are made, for example, by an acrylate adhesive. Of course, the barrier films 4a, 4b can be permanently or temporarily adhered to the intermediate layer 3a, 3b by other methods mentioned in the description of the invention.

In the second step b), a stack sequence is placed. To this end, a pre-lamination including the second intermediate layer 3b and the second barrier film 3b is disposed on the inner pane 2 of the composite pane 100. The second barrier film 3b is disposed on the side of the second intermediate layer 3b away from the inner pane 2. After that, the functional element 5 is disposed on the second intermediate layer 3b in the area of the second barrier film 3b. Here, the barrier film 3b and the functional element 5 are dimensioned so that, for example, the barrier film 3b completely covers the functional element 5 and protrudes from all sides by an overhang u of 5 mm, for example. Become angry.

After that, a preliminary lamination comprising the first intermediate layer 3a and the first barrier layer 4a is disposed on the second intermediate layer together with the second barrier layer 4b and the functional element 5. The first barrier layer 4a is located in direct contact with the functional element 5 and consequently on the side of the first intermediate layer 3a facing the functional element 5. Here, the barrier film 3a is dimensioned so that, for example, the barrier film 4a completely covers the functional element 5 and protrudes from all sides by an overhang u of eg 5 mm. The first barrier film 4a and the second barrier film 4b coincide and contact each other in the entire area of the overhang u beyond the functional element 5, for example.

Thereafter, the outer pane 1 of the composite pane 100 is disposed on the first intermediate layer 3a and in direct contact.

Of course, the stack sequence may be manufactured in reverse order starting from the outer pane 1 on which the first intermediate layer 3a is disposed, for example. Further, of course, more films or layers could be arranged between the individual elements of the stack sequence or on the outer surfaces of the inner pane 2 and/or the outer pane 1.

The fixed adhesion between the barrier films 4a, 4b and the intermediate layers 3a, 3b has a significant advantage. As a result of fixing the very thin barrier films 4a, 4b to the fairly thick intermediate layers 3a, 3b, the barrier films 4a, 4b can be processed and positioned much more easily. In particular, bubbles or twisting of the barrier films 4a and 4b can be prevented. The entire positioning process is easier to handle and easier to automate.

In the last step c), the stack sequences of steps a) and b) are joined together in a stack. Accordingly, a finished composite pane 100 with functional elements 5 embedded between the intermediate layers 3a and 3b is manufactured. By the fixed embedding of the functional element 5, the barrier films 4a, 4b are fixedly bonded to the functional element 5 and to each other in the region of the overhang u. In this example, the barrier films 4a, 4b completely cover the functional element 5 and hermetically surround it.

2a, 2c and 2d show a further embodiment of a composite pane 100 according to the invention of FIGS. 1a, 1c and 1d. Since the composite pane 100 of FIGS. 2A, 2C and 2D substantially corresponds to the composite pane 100 of FIGS. 1A, 1C and 1D, only the differences will be discussed below.

The substantial difference from FIGS. 1A, 1C and 1D is that the barrier films 4a and 4b in FIGS. 2A, 2C, and 2D are of a frame shape rather than an entire surface. In addition, the manufacturing method according to the present invention is different as shown in FIG. 2B.

Figure 2b shows a schematic diagram of a method according to the invention for producing the composite pane 100 of Figures 2a, 2c and 2d.

According to this, in a first step a), the first barrier layer 4a is disposed on the first intermediate layer 3a and is permanently bonded thereto, for example via a first adhesive bond 7a. Of course, the barrier film 4a may be permanently or temporarily bonded to the intermediate layer 3a by other methods mentioned in the description of the invention.

In the second step b), the stack sequence is placed. To this end, a second intermediate layer 3b is disposed on the inner pane 2 of the composite pane 100. After that, the frame-shaped second barrier film 4b is disposed on the second intermediate layer 3b. After that, the functional element 5 is disposed on the second intermediate layer 3b in the region of the second barrier film 4b. Here, the barrier film 4b and the functional element 5 are, for example, the barrier film 4b covering the functional element 5 in a frame shape in its edge region (i.e. its side edges), and on all sides It is dimensioned to protrude, for example, with an overhang u of 5 mm.

After that, a preliminary lamination comprising the first intermediate layer 3a and the first barrier layer 4a is disposed on the second intermediate layer 3b having the second barrier layer 4b and the functional elements 5. The first barrier layer 4a then comes into direct contact with the functional element 5 and, as a result, is disposed on the side of the first intermediate layer 3a facing the functional element 5. Here, the first barrier film 4a is dimensioned to protrude from all sides with an overhang u of 5 mm covering the functional element 5 in a frame shape, for example in the edge region. The first barrier film 4a and the second barrier film 4b coincide with each other and contact each other in the entire area of the overhang u beyond the functional element 5, for example.

After that, the outer pane 1 of the composite pane 100 is disposed on the first intermediate layer 3a and in direct contact.

Of course, the stack sequence may be produced in the reverse order, for example starting from the outer pane 1 or the like on which the first intermediate layer 3a is disposed thereafter. In addition, of course, more films or layers could be arranged between the individual elements of the stack sequence or on the outer surface of the inner pane 2 and/or the outer pane 1.

In the last step c) the stack sequences of steps a) and b) are joined together in a stack. Thus, a finished composite pane 100 with functional elements 5 embedded between the intermediate layers 3a, 3b is produced. By the fixed embedding of the functional element 5, the barrier films 4a, 4b may be fixedly bonded to the functional element 5 and to each other in the overhang (u) region. In this example, the barrier films 4a, 4b cover the edges of the functional element 5 and hermetically surround the side edges 5.1, 5.2, 5.3, 5.4 of the functional element 5.

3a, 3b and 3c show details of an alternative composite pane 100 according to the invention as a windshield with an electrically controllable sun visor in each case. Since the composite pane 100 of FIGS. 3A to 3C substantially corresponds to the composite pane 100 of FIGS. 1A, 1C and 1D, only the differences will be discussed below.

The windshield comprises a trapezoidal composite pane 100 having an outer pane 1 and an interior pane 2 joined to each other via two intermediate layers 3a and 3b. The outer plate glass 1 has a thickness of 2.1 mm and is made of green soda-lime glass. The inner plate glass 2 has a thickness of 1.6 mm and is made of transparent soda-lime glass. The windshield has an upper edge D facing the ceiling from the installation position and a lower edge M facing the engine compartment from the installation position.

The windshield is equipped with an electrically controllable functional element 5 as a sun visor, which is placed in the area above the central field of view B (defined in ECE-R43). The sun visor is formed by a commercially available PDLC multilayer film as a functional element 5 embedded in the intermediate layers 3a, 3b. The height of the sun visor is 21 cm, for example. The first intermediate layer 3a is bonded to the outer pane 1; The second intermediate layer 3b is bonded to the inner pane 2. The third intermediate layer 3c positioned therebetween has a cutout, and a PDLC multilayer film cut to fit size is inserted into it with an exact fit, that is, all sides are inserted at the same height. The third intermediate layer 3c thus forms a kind of universal frame for the functional element 5, so to speak, and is thus encapsulated with a thermoplastic material and protected by doing so.

The first intermediate layer 3a has a colored area 6 arranged between the functional element 5 and the outer pane 1. The light transmittance of the windshield is thus further reduced in the area of the functional element 5 and the milky appearance of the PDLC functional element 5 is alleviated in the diffuse state. The windshield's aesthetic is thus designed to be considerably more attractive. The first intermediate layer 3a has, for example, an average light transmittance of 30% in the region 6, and good results are obtained.

Region 6 can be uniformly colored. However, it is often visually more attractive to reduce the coloring in the direction of the lower edge of the functional element 5 so that the colored and uncolored areas transition smoothly to each other.

In the illustrated case, the lower edge of the colored area 6 and the lower edge of the PDLC functional element 5 (here its side edge 5. 1) are arranged flush with the barrier film 4. However, this is not necessarily the case in this case. It is possible for the colored area 6 to protrude beyond the functional element 5, and conversely it is also possible for the functional element to protrude beyond the colored area 6. In the latter case, it is not the entire functional element 5 that is connected to the outer pane 1 via a colored area 6.

The controllable functional element 5 is a multilayer film composed of two surface electrodes 12, 13 and an active layer 11 between two carrier films 14, 15. The active layer 11 comprises a polymer matrix having liquid crystals dispersed therein, the liquid crystal orienting itself as a function of the voltage applied to the surface electrode, whereby the optical properties can be controlled. The carrier films 14, 15 are made of PET and have a thickness of 0.125 mm, for example. A carrier film 14, 15 is provided on a coating of ITO facing the active layer 11 of about 100 mm thick and forming the electrodes 12, 13. The surface electrodes 12, 13 may be connected to the vehicle's electrical system via a busbar (not shown) (eg, formed by silver-containing screen printing) and a connection cable (not shown).

The windshield typically has a circumferentially peripheral masking print 9 formed of opaque enamel on the inner side of the outer pane 1 and the inner pane 2 (facing the interior of the vehicle from the installation position). . The side edges of the functional element 5-excluding the side edge towards the central field of view (B)-from the upper edge D and the side edges of the windshield so as to be covered by this masking print 9 The distance of 5) is smaller than the width of the masking print 9. Electrical connections (not shown) are also conveniently applied in the area of the masking print 9 and are thus hidden.

So-called "high flow PVB", which has a stronger flow behavior compared to standard PVB films, can preferably be used for the intermediate layers 3a, 3b, 3c. Thus, the layers flow more strongly around the barrier film 4 and functional element 5, create a more uniform visual impression, and the transition from functional element 5 to intermediate layer 3c is less noticeable. do. "High flow PVB" can be used for all or even one or more of the intermediate layers 3a, 3b, 3c.

4 shows a plan view of another embodiment of a composite pane 100 according to the invention as a windshield with an electrically controllable sun visor. The windshield and functional element 5 as a controllable sun visor substantially corresponds to the embodiment of FIG. 5. However, the PDLC functional element 5 is divided into six strip-like segments by horizontal isolation lines 16. The isolation line 16 has a width of 40 μm to 50 μm and a mutual distance of 3.5 cm, for example. They are introduced into prefabricated multilayer films using a laser. The isolation line 16, in particular, divides the electrodes 12, 13 into separate strips from each other, and in each case has a divided electrical connection. Thus, segments can be switched independently of each other. The thinner the isolation lines 16 are, the less conspicuous they are. However, the thinner isolation lines 16 can be realized using an etching method.

As a result of the division, the height of the darkened functional element 5 can be adjusted. Thus, depending on the position of the sun, the driver can darken all or even part of the sun visor. The figure shows that the upper half of the sun visor is darkened and the lower half is transparent.

In a particularly convenient embodiment, the functional element 5 is controlled by a capacitive switching surface arranged in the area of the functional element, where the driver specifies the degree to which he is darkened by the position at which he touches the pane. Alternatively, the functional element 5 may be controlled by sensing a gesture or as a function of the state of the pupil or eyelid as determined by the camera and appropriate evaluation electronics.

FIG. 5A shows a cross section through another embodiment of the composite pane 100 of FIG. 1A along the line X-X′, wherein the embodiment shown in FIG. 5A includes a first intermediate layer 3a and an outer pane ( 2) It differs from the embodiment shown in Fig. 1C in that it is a third intermediate layer 3c having a recess 20 in the region of the functional element 5 disposed between. In other words, the functional element 5 is completely arranged in the area of an orthogonal projection to the outer pane 2 of the recess 20. Further, the functional element 5 is partially or completely arranged on a plane different from the third intermediate layer 3c.

During lamination, the softened material of the first intermediate layer 3a penetrates into the recess 20 of the third intermediate layer 3c.

Of course, more layers or films (not shown), such as a functional layer and an infrared reflective layer with or without a carrier layer, for example, may be disposed within the recess 20.

Fig. 5b shows a schematic diagram of the layer arrangement of the embodiment of the composite pane according to the invention shown in Fig. 5a prior to lamination. In Fig. 5b, due to the stack sequence of the composite pane 100 according to the present invention, the barrier films 4a, 4b have a functional element 5 arranged between the first intermediate layer 3a and the second intermediate layer 3b. It is previously bonded to the front first intermediate layer 3a or the second intermediate layer 3b. Bonding is carried out, for example, by spraying an organic solvent and for example acetone on one of the surfaces of the barrier films 4a, 4b in each case. After that, the surfaces of the barrier films 4a and 4b sprayed with the solvent are disposed on each of the intermediate layers 3a and 3b. On the other hand, the solvent generates cohesive force due to the surface tension of the solid. In addition, the solvent causes slight dissolution of the surface, causing close adhesion between the surfaces of the barrier films 4a and 4b and the surfaces of the intermediate layers 3a and 3b. The resulting adhesion enables stable transport and precise positioning of the intermediate layers 3a and 3b together with the barrier films 4a and 4b.

6 shows an embodiment of the method according to the invention with reference to a flow chart: in a first step (I), a first barrier film 4a and a first intermediate layer 3a and/or a second barrier film 4b ) And the second intermediate layer 3b are fixedly bonded to each other temporarily or permanently. In a second step (II), a stack sequence is produced, wherein the outer pane 1, the first intermediate layer 3a, the first barrier film 4a, a functional element 5 with electrically controllable optical properties, The second barrier film 4b, the second intermediate layer 3b, and the inner pane 2 are disposed above each other in this spatial order. In the third step (III) the stack sequence is fixedly or permanently bonded by lamination.

1: outer pane
2: inner pane
3a: first intermediate layer
3b: second intermediate layer
3c: third intermediate layer
4a: first barrier film
4b: first barrier film
5: Functional elements having optical properties that can be controlled electrically
5.1, 5.2, 5.3, 5.4: side edges of the functional element (5)
6: colored region of the first intermediate layer 3a
7a, 7b: adhesive bond
9: masking print
11: Active layer of functional element (5)
12: surface electrode of the functional element 5
13: Surface electrode of functional element (5)
14: carrier film
15: carrier film
16: isolation line
20: recess of the third intermediate layer 3c
100: composite pane
B: central view of the windshield
D: upper edge of windshield, ceiling edge
M: lower windshield edge, engine edge
u: overhang
X-X': joint
Z:: extended area

Claims (17)

A method of manufacturing a composite pane 100 having a functional element 5 having electrically controllable optical properties, comprising at least
a) the first barrier film 4a and the first intermediate layer 3a and/or the second barrier film 4b and the second intermediate layer 3b are fixedly bonded to each other temporarily or permanently,
b) Outer pane (1), first intermediate layer (3a), first barrier film (4a), functional element (5) having electrically controllable optical properties, second barrier film (4b), second intermediate layer (3b) ) And the inner pane 2 are arranged on top of each other in this spatial order, and
c) A method of manufacturing a composite pane, wherein the stack sequence is laminated and bonded.
The method of claim 1,
A method of manufacturing a composite pane in which an intermediate layer with built-in functional elements 5 is formed from a first intermediate layer 3a and a second intermediate layer 3b.
The method according to claim 1 or 2,
A method of manufacturing a composite plate glass in which the first barrier film 4a and the second barrier film 4b are disposed substantially coincident with each other.
The method according to any one of claims 1 to 3,
The barrier film (4a, 4b) is arranged as an overhang (u) over the functional element (5), the functional element (5) is at least partially and preferably completely covered with a barrier film (4a, 4b) composite pane Manufacturing method.
The method according to any one of claims 1 to 4,
The barrier films 4a, 4b are composite panes permanently bonded to the intermediate layers 3a, 3b by adhesive bonds 7a, 7b, by fusion bonds and/or by press bonds. Manufacturing method.
The method according to any one of claims 1 to 4,
The barrier films 4a, 4b and the intermediate layers 3a, 3b are adhered to each other by a solvent, preferably an organic solvent, particularly preferably acetone, alcohol, in particular ethanol, isopropanol or chloroform, and preferably the solvent A method of making a composite pane which is volatilized before and/or after the placement of the stack sequence in step b) and/or during step c).
A composite pane (100) manufactured according to any one of claims 1 to 6, wherein the intermediate layer (3a, 3b) contains at least one thermoplastic polymer film having at least one plasticizer, and the barrier film (4a, 4b) is a composite plate glass implemented to prevent diffusion of the plasticizer through the barrier films 4a and 4b.
The method of claim 7,
The intermediate layers 3a, 3b contain at least 3% by weight, preferably at least 5% by weight, particularly preferably at least 20% by weight, more preferably at least 30% by weight, and in particular at least 40% by weight of plasticizer, And the plasticizer is preferably triethylene glycol or an aliphatic diester of tetraethylene glycol, particularly preferably triethylene glycol bis-(2-ethylhexanoate).
The method according to claim 7 or 8,
The interlayer (3a, 3b) is a composite pane containing at least 60% by weight, preferably at least 70% by weight, particularly preferably at least 90% by weight, and in particular 97% by weight of polyvinyl butyral (PVB).
The method according to any one of claims 7 to 9,
A composite plate glass in which the functional element 5 is a polymer dispersed liquid crystal (PDLC) film.
The method according to any one of claims 7 to 10,
The barrier film (4a, 4b) is a low plasticizer or a plasticizer-free agent, and is preferably polyethylene terephthalate (PET) or polyvinyl fluoride (PVF) or polyethylene (PE), or a composite containing the same plate glass.
12. An overhang (u) of the barrier film (4a, 4b) beyond the functional element (5) according to one of claims 7 to 11, is at least 0.5 mm, preferably at least 2 mm, particularly preferably at least Composite pane of 5 mm, and in particular at least 10 mm.
The method according to any one of claims 7 to 12,
A composite pane in which the overhang (u) of the barrier films 4a, 4b beyond the functional element 5 is less than 50 mm, preferably less than 30 mm and particularly preferably less than 20 mm.
The method according to any one of claims 7 to 13,
The barrier films 4a, 4b are composite panes arranged in a frame shape along the side edges 5.1, 5.2, 5.3, 5.4 of the functional element 5.
The method according to any one of claims 7 to 14,
The composite pane in which the barrier films 4a and 4b are fixedly bonded to each other in the region of the overhang u after the lamination process in step c).
The method according to any one of claims 7 to 15,
The functional element 5 and barrier films 4a, 4b are circumferentially surrounded by a third intermediate layer 3c.
With an electrically controllable functional element (5) according to any one of claims 7 to 16 as interior or exterior glazing in a vehicle or building and an electrically controllable functional element (5) as a sunscreen or privacy screen. The use of the composite plate glass 100.

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