Method for producing a composite glass pane

Abstract

The invention relates to a method for producing a composite pane (1), comprising the following steps: a) providing a first stack sequence (2) comprising a first pane (3), a layer (4) made of plastic and an electro-optic functional film (5) surrounded by a layered frame (6) made of plastic, b) forming a second stack sequence (12) by providing a second glass sheet (9) on the first stack sequence (2) and interposing a separation membrane (8) therebetween, c) laminating the second stack sequence (12) under the action of heat, vacuum and / or pressure, d) removing the second glass sheet (9) and the separation membrane (8) from the laminated second stack sequence (12), e) applying an adhesive strip (10) to the layered frame (6) of the first stack sequence (2), the adhesive strip (10) continuously surrounding the electro-optical functional film (5) except at least one interruption (11), f) arranging the second pane (9) on the adhesive strip (10), the at least one interruption (11) of the adhesive strip (10) forms an opening (14) of the cavity (13), g) filling the cavity (13) by injecting an optically transparent adhesive (15) into the cavity (13) through the opening (14), h) curing the optically transparent adhesive (15) in the cavity (13).

Description

[0001] The present invention belongs to the technical field of glass plate production, and relates to a method for producing a composite glass plate, in particular to a composite glass plate produced by the method according to the present invention and a use thereof.

[0002] Composite glass panes usually consist of two single glass panes, usually made of glass, which are firmly joined (laminated) to each other by at least one intermediate layer made of plastic. Modern composite glass panes, in particular windshield panes of motor vehicles, can have complex curvatures in the horizontal and / or vertical direction in order to meet the aerodynamic requirements and design specifications of automobile manufacturers. They also increasingly include electrically controllable functional elements, which display information for the driver and / or front passenger, serve as lighting devices and / or can change the optical transparency of the glass pane, for example in the form of a sun visor. In particular, the optical transparency of the glass pane can be switched over a large area, for example in the top glass pane, the rear side glass pane or the partition glass pane. Electrically controllable functional elements in the form of electro-optical functional films are advantageously laminated into the composite glass pane. In particular, electro-optical functional films with liquid crystal-based functional layers (which are based on the so-called "guest-host" effect) represent interesting possibilities for realizing electro-optical switching functions in composite glass panes in a simple, space-saving, cost-effective and reliable manner in applications. Here and below, for simplicity, the electro-optical functional film having a liquid crystal-based functional layer based on the "guest-host" effect is referred to as a "guest-host film".

[0003] The guest-host film usually comprises a nematic liquid crystal (host) which is provided with an additive (guest), wherein for example dichroic dye molecules which absorb light anisotropically are used as additives. Since the molecules of the additive have an elongated form, their orientation can be controlled by the orientation of the liquid crystal molecules (i.e. the host), which is achieved in practice by applying an electric field to the liquid crystal. In this way, for example, the optical transparency of the guest-host film can be controlled very precisely by an external electric field.

[0004] Until now, it has not been possible to introduce guest-host films into composite glass panes by means of conventional lamination methods used in industry. The reason for this is that guest-host films have hitherto not been able to be integrated into conventional production processes for producing composite glass panes. In fact, this represents a great challenge for the simple and cost-effective industrial mass production of composite glass panes with guest-host films. As practice has shown, guest-host films react very sensitively to mechanical loads caused by uneven contact pressures due to their physical properties, which are like those of liquids. Even the smallest local deviations in the contact pressure during the lamination of the composite glass panes and in the laminated composite glass panes can lead to local optical defects in the guest-host film, which can render the composite glass pane unusable.

[0005] However, in the mass production of curved composite glass panes, it is inevitable that the individual glass panes of the composite glass pane have shapes that do not match exactly. On the contrary, slight deviations of the shape always occur within the usual dimensional tolerances, which lead to locally higher pressure loads during the lamination process. In the case of conventional composite glass panes, this is not a big deal, since these locally higher pressure loads do not impair the optical quality of the composite glass pane. On the contrary, these locally higher pressure loads are sufficient to produce undesirable local optical defects (e.g. local discoloration or color fading or turbidity) in the guest-host film. Moreover, in the production of composite glass panes, local shape deviations or locally higher pressure loads can be completely desirable.

[0006] To date, there are no methods known from the prior art for laminating composite glass panes which allow the industrial mass production of composite glass panes having a guest-host film integrated into the composite glass pane as an electro-optical functional element of usable optical quality.

[0007] WO 2021 / 249801 A1 describes a method for producing a composite glass pane with an integrated functional film, wherein pressure loads on the functional film are to be avoided. In the finished composite glass pane, the functional film is laminated between two thermoplastic composite films.

[0008] The object of the present invention is, on the other hand, to provide an improved method for producing composite glass panes with an integrated guest-host film, by which composite glass panes with high optical quality can be produced in industrial mass production. In particular, the method should be usable in existing production plants so that composite glass panes with an integrated guest-host film can be produced in large quantities in a relatively simple, cost-effective and reliable manner.

[0009] These and further objects are achieved according to the proposal of the invention by a method for producing a composite glass pane with an integrated electro-optical functional film according to the independent claim. Advantageous embodiments of the invention result from the dependent claims.

[0010] According to the invention, a method for producing a composite glass pane, in particular a composite vitreous glass pane, with an integrated electro-optical functional film is shown. The electro-optical functional film is integrated into the composite glass pane, ie it is located between the two individual glass panes of the composite glass pane.

[0011] The method for producing a composite glass pane comprises the following steps, which are preferably, but not necessarily, carried out in the order shown (steps according to the order of the alphabetical designations):

[0012] Step a)

[0013] A (non-laminated) first stacking sequence is provided or formed, which comprises, in the following order, a first glass pane, a layer of a preferably thermoplastic plastic and an electro-optical functional film which is surrounded by a layered frame of a preferably thermoplastic plastic.

[0014] Step b)

[0015] The second stacking sequence is formed by arranging a second glass sheet on the first stacking sequence with a separating film inserted therebetween. The layer of preferably thermoplastic plastic and the electro-optical functional film surrounded by a layered frame of preferably thermoplastic plastic and the separating film are located between the two glass sheets. The separating film is located between the electro-optical functional film surrounded by a layered frame of preferably thermoplastic plastic and the second glass sheet.

[0016] Step c)

[0017] Laminating the second stacking sequence under the action of heat, vacuum and / or pressure on the second stacking sequence. In this method step, heat, vacuum and / or pressure are applied to the second stacking sequence formed in step b), wherein a firm joining of the two glass panes is prevented by the separating film.

[0018] Step d)

[0019] The second glass sheet and the separation film are removed from the second stacking sequence, wherein the first stacking sequence remains as a pre-composite.

[0020] Step e)

[0021] A sticky adhesive strip is applied to the layered frame of the first stacking sequence, wherein the adhesive strip continuously surrounds the electro-optical functional film except for at least one interruption.

[0022] Step f)

[0023] The second glass plate is arranged on the sticky adhesive strip in such a way that a cavity defined by the adhesive strip is formed between the electro-optical functional film and the second glass plate, wherein the at least one interruption of the adhesive strip forms an opening of the cavity.

[0024] Step g)

[0025] The cavity is filled by injecting a flowable optically clear adhesive into the cavity through the opening.

[0026] Step h)

[0027] The optically clear adhesive in the cavity is cured.

[0028] By curing the optically clear adhesive in the cavity, a composite glass pane having two firmly joined glass panes is produced.

[0029] The composite glass panel produced by the method according to the present invention is generally used to separate an interior space from the external environment. The composite glass panel comprises a first glass panel having an outer side and an inner side and a second glass panel having an inner side and an outer side, which are firmly bonded to each other. The first glass panel can also be called an outer glass panel, and the second glass panel is called an inner glass panel. The surfaces or faces of the two single glass panels are respectively called face I, face II, face III and face IV from the outside to the inside. For example, the first glass panel is the outer glass panel of the composite glass panel, and the second glass panel is correspondingly its inner glass panel. In the installed state, the outer glass panel faces the external environment. The electro-optical functional film is located between the two single glass panels, i.e., integrated into the composite glass panel.

[0030] In step a), a layer made of a preferably thermoplastic plastic is arranged between the first glass plate and the electro-optical functional film. The layer made of a preferably thermoplastic plastic and the layered frame made of a preferably thermoplastic plastic can each exist as a preferably thermoplastic film, wherein the electro-optical functional film is arranged in a cutout of a preferably thermoplastic film for the layered frame so that the preferably thermoplastic film surrounds the electro-optical functional film in a frame-like manner. The layer made of a preferably thermoplastic plastic is also preferably arranged between the first glass plate and the layered frame made of a preferably thermoplastic plastic. The layer made of a preferably thermoplastic plastic and the layered frame made of a preferably thermoplastic plastic can be fused together. In this case, the layered frame can also be defined (at least in theory) around the electro-optical functional film.

[0031] The layered frame preferably completely surrounds the electro-optical functional film without interruption in the manner of a picture frame edge, i.e. completely surrounds the electro-optical functional film. The frame is of layered design, i.e. a layer made of a preferably thermoplastic material, which surrounds the electro-optical functional film in a frame-like manner. The dimensions of the layer made of a preferably thermoplastic plastic are designed so that it covers at least the electro-optical functional film in terms of area (in a vertical view through the electro-optical functional film). Preferably, the dimensions of the layer made of a preferably thermoplastic plastic are designed so that it covers the electro-optical functional film and the layered frame surrounding it in terms of area (in a vertical view through the electro-optical functional film and the layered frame).

[0032] For example, the layer of preferably thermoplastic plastic and the layered frame of preferably thermoplastic plastic are provided in each case by at least one preferably thermoplastic film. The electro-optical functional film is inserted here into the cutout of the preferably thermoplastic film for the layered frame. Preferably, the layered frame of preferably thermoplastic plastic has the same thickness as the electro-optical functional film, so that the electro-optical functional film does not protrude or recede relative to the layered frame (in a direction perpendicular to the electro-optical functional film). Preferably, the size of the electro-optical functional film together with the surrounding layered frame corresponds to the size of the layer of preferably thermoplastic plastic.

[0033] In step b), the second stacking sequence is formed by arranging the second glass plate on the first stacking sequence and inserting a separation film therebetween. The separation film, for example a Teflon film (PTFE film), is placed on the electro-optical functional film and a layered frame made of a preferably thermoplastic plastic. The separation film is designed so that after lamination in step c), it and thus the second glass plate can be removed again. Therefore, the separation film preferably has no adhesive properties and can be removed without loss after lamination. The second stacking sequence is generated by the first stacking sequence, i.e. the first stacking sequence is a component of the second stacking sequence. The second stacking sequence is generated by arranging the second glass plate on the first stacking sequence and inserting a separation film therebetween.

[0034] In step c), the second stacking sequence is laminated under the action of heat, vacuum and / or pressure.

[0035] After lamination, in step d), the separation film and the second glass sheet are removed from the second stacking sequence again, so that the first stacking sequence remains in laminated form (pre-composite). In the pre-composite, the electro-optical functional film is fixed to the first glass sheet. In addition, a layered frame around the electro-optical functional film and a layer made of a preferably thermoplastic plastic are bonded to each other between the electro-optical functional film and the first glass sheet.

[0036] In step e), the viscous adhesive strip is applied to the layered frame surrounding the electro-optical functional film. The adhesive strip is viscous and remains in the applied position at least before the second glass sheet is placed, but is not dimensionally stable and can be deformed by external influences.

[0037] Apart from at least one interruption, the adhesive strip completely surrounds the electro-optical functional film.

[0038] In step f), the second glass sheet is placed on the adhesive strip, which is deformed between the two glass sheets due to shape instability. The second glass sheet is placed in such a way that a cavity is formed between the electro-optical functional film and the second glass sheet (and optionally also between the region of the layered frame and the second glass sheet). The adhesive strip completely surrounds or delimits the cavity, except for the at least one interruption, which forms an opening into the cavity after the second glass sheet is placed on the adhesive strip.

[0039] Next, in step g), the cavity formed in step f) is filled with a curable optically clear adhesive, which is liquid or flowable and introduced into the cavity through the opening. The optically clear adhesive is curable, i.e. it can be irreversibly changed into a cured state. Generally, it is a plastic that is changed into a polymer cross-linked state by curing. Unlike thermoplastics that can be softened by supplying heat and also become flowable, the optically clear adhesive cannot be changed into a flowable state once it has been cured. Therefore, the optically clear adhesive is not a non-curable thermoplastic.

[0040] Finally, in step h), the optically transparent adhesive in the cavity is cured to produce the composite glass pane. The optically transparent adhesive can be cured by heating, by the action of electromagnetic radiation, preferably ultraviolet radiation, and / or chemically. The curing is preferably carried out by supplying heat or by increasing the temperature and / or ultraviolet radiation.

[0041] The present invention advantageously shows a way to minimize or even completely avoid uneven contact pressure on the electro-optical functional film. To this end, the electro-optical functional film is not laminated between two thermoplastic films, which at least cannot fully absorb local load peaks, but is only fixed to the first glass plate by a thermoplastic interlayer. Through the cavity filled with a curable adhesive defined by the adhesive strip, the two glass plates can be firmly bonded to each other, wherein mechanical loads on the electro-optical functional film are avoided, and thus the occurrence of optical defects in the optoelectronic functional film is avoided. After the optically transparent adhesive is cured, the two glass plates of the composite glass plate are permanently and firmly bonded to each other. Unlike common lamination methods, in the method according to the present invention, uneven contact pressure on the electro-optical functional film is avoided and the risk of local defects in the electro-optical functional film is minimized. This is the main advantage of the present invention.

[0042] The viscous adhesive strip is preferably applied to the layered frame by extrusion. For this purpose, a program-controlled robot arm with an injection head can be used in particular. Advantageously, the viscous adhesive strip consists of a thermoplastic, such as polyvinyl butyral (PVB), which becomes viscous by heating (e.g. to about 220° C.) and can therefore be applied in a simple manner to the layered frame surrounding the electro-optical functional film. Alternatively, the adhesive strip can also consist of a thermosetting plastic, such as polyurethane.

[0043] In an advantageous embodiment of the method according to the invention, after step g), i.e. after the cavity is filled with the optically transparent adhesive, and in particular after step h), i.e. after the optically transparent adhesive has cured, the at least one opening of the cavity is closed. For example, a thermoplastic is used for this purpose, preferably the same thermoplastic as has been used for the adhesive strip. However, other suitable materials known to a person skilled in the art can also be used for this purpose. This measure has the advantage that the cavity is completely sealed.

[0044] In a further advantageous embodiment of the method according to the invention, at least two, in particular exactly two, interruptions of the adhesive strip are formed in step e), which interruptions form at least two, in particular exactly two openings of the cavity in step f). This measure has the particular advantage that air can escape from the cavity through the at least one further opening when the cavity is filled with the flowable, optically transparent adhesive. The cavity can thus be filled completely, advantageously reliably and safely.

[0045] In the method according to the invention, the second glass sheet rests on the adhesive strip, in this case at a defined distance from the first stacking sequence or the first glass sheet (freely selected). This is entirely possible due to the viscous (non-dimensionally stable) nature of the adhesive strip. The viscous adhesive strip yields by a change of shape, i.e. the adhesive strip deforms between the first stacking sequence and the second glass sheet. In an advantageous embodiment of the method according to the invention, the distance between the first stacking sequence or the first glass sheet and the second glass sheet is set by at least one spacer. This has the particular advantage that the distance between the two glass sheets can be set very precisely.

[0046] In principle, the arrangement and course of the adhesive strip on the layered frame surrounding the electro-optical functional film can be freely selected, as long as it is ensured that, apart from at least one interruption, the adhesive strip completely surrounds the electro-optical functional film. The adhesive strip is preferably applied to the layered frame in an area corresponding to the edge area of ​​the first glass pane (in a vertical view through the first glass pane) or in the edge area of ​​the layered frame.

[0047] The first and second glass sheets each have two surfaces (main surfaces) which are provided for perspective and are in particular arranged substantially parallel to one another and a (surrounding) edge face or end face extending between them. The above-mentioned "edge region" of the first glass sheet is to be understood as meaning a (surrounding) region of each main surface of the first glass sheet (in a vertical view through the first glass sheet) which extends from the surrounding edge face or end face in the direction of the interior of the glass sheet, wherein the dimension of the edge region perpendicular to the edge face or end face is, for example, >0 cm to a maximum of 20 cm, in particular a maximum of 10 cm. The edge region is in any case arranged at an edge position, i.e. directly adjacent to the edge face or end face. For example, the edge region is designed in the form of a surrounding strip of the same size.

[0048] The volume of the adhesive strip is preferably dimensioned such that, when the second glass pane is arranged on the adhesive strip, the adhesive strip is partially pressed out between the first and second glass panes. The protruding part of the adhesive strip is then removed, which has the advantage that the edge of the composite glass pane can be made aesthetically appealing in a simple manner.

[0049] The electro-optical functional film can be of any design in principle. Electrically switchable or electrically controllable functional films are, for example, SPD (suspended particle device), PDLC (polymer dispersed liquid crystal), electrochromic or electroluminescent functional films, and are known per se to those skilled in the art. The functional film can also be a polymer conductive layer, which, for example, contains at least one conjugated polymer or a polymer equipped with conductive particles. Typically, the functional film contains a carrier film with a functional layer. The carrier film preferably contains a polymer, in particular polyvinyl butyral (PVB), ethylene vinyl acetate (EVA), polyurethane (PU), polyethylene terephthalate (PET), thermoplastic polyurethane (TPU) or a combination thereof.

[0050] In the case of a guest-host film having a functional layer made of a liquid crystal material containing embedded additives, the method according to the invention is particularly advantageous. Reference is made to the above statements about guest-host films. The guest-host film itself is well known to those skilled in the art, so it is not necessary to discuss it in more detail here. The guest-host film is commercially available, for example under the name of "light control film" (light control film), for example from Dai Nippon Printing Co., Ltd. in Japan under the product name LCF005 (EU). The electro-optical functional film is preferably a liquid crystal-based functional film containing embedded additives, i.e. a guest-host film.

[0051] In principle, the curable optically transparent (transparent) adhesive can be selected arbitrarily, provided that in the non-cured state, it is or can become flowable or liquid (for example by temperature increase) and can be irreversibly cured. The transparent adhesive is, for example, based on silicone. Optically transparent adhesives are known by the abbreviation OCA (optically clear adhesive), wherein for liquid optically transparent adhesives, the abbreviation LOCA (liquid optically clear adhesive) is particularly used. Optically transparent adhesives are characterized by high optical quality and are mainly used in places where a quasi-invisible adhesive layer is required, such as displays or touch panels. Optically transparent adhesives are therefore often used in touch-sensitive displays, for example to firmly bond them to LCD displays, or even to firmly bond plastic covers to touch-sensitive displays. After application, the LOCA is often cured by ultraviolet radiation. Optically transparent adhesives are freely commercially available from many suppliers.

[0052] The curable optically clear adhesive may, for example, contain polyurethane (PU), polyacrylate, polyacetate resin, casting resin, silicone or copolymers or mixtures thereof, or consist of them. The optically clear adhesive advantageously contains a casting resin, in particular a casting resin based on polyurethane or silicone, or consists of them.

[0053] Depending on the adhesive used, the curing of the optically transparent adhesive can be achieved by thermal curing (i.e. supplying heat), by electromagnetic radiation, in particular ultraviolet radiation, infrared radiation or microwave radiation, by ultrasound, by water supply or by chemical reactions of various components (in particular two-component adhesives). In many curing processes, the time required for the curing of the liquid optically transparent adhesive is affected by temperature. In particular, curing can be accelerated by supplying heat. On the contrary, curing can be slowed down by cooling. The curing time can be controlled, for example, by heating or cooling the liquid optically transparent adhesive.

[0054] Each single glass pane of the composite glass pane (i.e. the first glass pane and the second glass pane) contains glass, particularly preferably flat glass, float glass, quartz glass, borosilicate glass, soda-lime glass, aluminosilicate glass, or transparent plastic, preferably hard transparent plastic, in particular polyethylene, polypropylene, polycarbonate, polymethyl methacrylate, polystyrene, polyamide, polyester, polyvinyl chloride and / or mixtures thereof, or preferably consists of them. Particularly preferably, each glass pane contains glass, in particular soda-lime glass, or consists of it. Suitable glasses are known, for example, from EP 0 847 965 B1.

[0055] The thickness of each individual glass pane of the composite glass pane can vary widely and be adjusted according to the requirements of the specific case. Preferably, glass panes with a standard thickness of 1.0 mm to 25 mm, preferably 1.4 mm to 2.1 mm, are used. The size of the glass panes can vary widely and depends on the application.

[0056] The composite glass pane can have any three-dimensional shape and can be flat or slightly or strongly curved in one or more directions in space. The composite glass pane preferably has a curvature, because the method according to the invention can be used particularly advantageously for curved composite glass panes. It should be understood that the two individual glass panes of the composite glass pane are curved in a corresponding manner to match each other exactly. As is conventional, the two individual glass panes are usually not exactly (identical) matched before lamination, but have shape inaccuracies within the production tolerance range.

[0057] The layers and the layered frame made of plastic contain polyvinyl butyral (PVB), ethylene vinyl acetate (EVA), thermoplastic polyurethane (TPU) and / or polyethylene terephthalate (PET) or preferably consist of them. For example, the layers and the layered frame consist of thermoplastic plastic. The plastic can be formed by one or more films, in particular thermoplastic films, stacked on top of each other, wherein the thickness of the film is preferably 0.25 mm to 1 mm, typically 0.38 mm or 0.76 mm.

[0058] In the sense of the present invention, "transparent" means that the total transmittance of the composite glass pane complies with the EU legal provisions for windshield panes and front side panes and preferably has a transmittance of more than 70%, in particular more than 75%, for visible light. For the rear side panes, roof panes and rear panes, "transparent" can also mean a transmittance of 10% to 70%. Thus, "opaque" means a transmittance of less than 15%, preferably less than 5%, in particular 0%.

[0059] In the method according to the invention, the second stacking sequence is laminated under the action of heat and / or pressure and optionally by evacuation. Methods known per se for producing composite glass sheets can be used. For example, the so-called autoclave method can be carried out at a high pressure of about 1 bar to 15 bar and a temperature of 100° C. to 145° C. for about 2 hours. For example, the vacuum bag or vacuum ring method known per se operates at about 200 mbar and 130° C. to 145° C. In addition, the second stacking sequence can also be pressed between at least one pair of rollers in a calender. Such devices for producing composite glass sheets are known and usually have at least one heating channel upstream of the pressing unit. The temperature during the pressing process is, for example, 40° C. to 150° C. The combination of calendering and autoclave methods has proven to be particularly successful in practice. Alternatively, a vacuum laminator can be used. These consist of one or more heatable and evacuable chambers in which the first glass sheet and the second glass sheet can be laminated, for example, within about 60 minutes at a reduced pressure of 0.01 mbar to 800 mbar and a temperature of 80° C. to 170° C.

[0060] The invention further extends to a composite glass pane, which is produced (obtained) in particular by the method according to the invention. The composite glass pane is preferably produced by the method according to the invention. The composite glass pane comprises a first glass pane, a layer made of a preferably thermoplastic plastic, an electro-optical functional film surrounded by a layered frame made of a preferably thermoplastic plastic, an adhesive strip on the layered frame, and a second glass pane, wherein the adhesive strip defines a cavity between the electrically switchable film and the second glass pane, the cavity being filled with a cured optically transparent adhesive.

[0061] The invention further extends to the use of a composite glass pane according to the invention in buildings or in land, air or water vehicles, in particular in motor vehicles, for example as a windshield, rear glass, side glass and / or roof glass. Preference is given to the use of the composite glass pane in motor vehicles, particularly preferably as roof glass.

[0062] Various embodiments of the present invention can be implemented alone or in any combination. In particular, the features described above and explained further below can be used not only in the combination shown, but also in other combinations or alone, without departing from the scope of the present invention.

[0063] The invention is explained in more detail below with reference to an embodiment, wherein reference is made to the accompanying drawings. In the simplified and not to scale illustrations:

[0064] Figure 1 A cross-sectional view of the first stacking sequence is shown,

[0065] Figure 2showing a top view of an electro-optical functional film having a layered frame of the first stacking sequence,

[0066] Figure 3 shows a cross-sectional view illustrating a second stacking sequence,

[0067] Figure 4 A cross-sectional view with adhesive strips is shown,

[0068] Figure 5 A top view of an electro-optical functional film with a layered frame and adhesive strips is shown,

[0069] Figure 6 shows a cross-sectional view, where Figure 4 Another glass plate is placed on the adhesive strip.

[0070] Figure 7 shows a cross-sectional view of a composite glass pane according to the invention,

[0071] Figure 8 A flow chart illustrating the method according to the invention is shown.

[0072] Reference Figures 1 to 7 , a method for producing a composite glass pane according to the invention and a composite glass pane according to the invention are explained by way of example. Figure 1 and 2 . Figure 1 A simplified schematic diagram shows a cross-sectional view of an embodiment of a first stacking sequence 2 for use in the production of a composite glass pane 1 according to the invention. A top view of the first stacking sequence 2 is shown in FIG. Figure 2 middle. Figure 1 The cross-sectional view corresponds to Figure 2 Cut line AA shown in .

[0073] The first stacking sequence 2 comprises a first glass pane 3, which is, for example, the outer glass pane of the composite glass pane 1. On the inner surface (surface II) of the first glass pane 3, a layer 4 made of thermoplastic material is arranged, for example, by arranging a film made of thermoplastic material on face II. An electro-optical functional film 5 is arranged on the layer 4 made of thermoplastic material. Figure 2It can be clearly seen in the top view of that the electro-optical functional film 5 is surrounded by a layered frame 6 made of thermoplastic material. To this end, a film made of thermoplastic material is provided, in which a cutout 7 has been introduced, wherein the electro-optical functional film 5 is inserted into the cutout 7 so that the remaining part of the film completely surrounds the electro-optical functional film 5. Here, the cutout 7 is introduced into the center of the film, for example. The thickness of the frame 6 made of thermoplastic material (i.e., the dimension perpendicular to the first stacking sequence 2) is the same as the thickness of the electro-optical functional film 5, so that the electro-optical functional film 5 does not protrude or retract relative to the frame 6 made of thermoplastic material.

[0074] like Figure 3 As shown, the second stacking sequence 12 is formed by the first stacking sequence 2. To this end, a separation film 8 (for example a PTFE film) is placed on the electro-optical functional film 5 having a surrounding frame 6 made of a thermoplastic material. Then the second glass plate 9 is placed on the separation film 8. Then the second stacking sequence 12 is laminated under heat, vacuum and / or pressure. The separation film 8 prevents adhesion of the second glass plate 9, so that after lamination, the second glass plate 9 together with the separation film 8 can be removed from the electro-optical functional film 5 having a surrounding frame 6 made of a thermoplastic material, and the laminated first stacking sequence 2 remains as a pre-composite for producing a composite glass plate 1. The separation film 8 is not part of the composite glass plate 1. During the lamination process, the electro-optical functional film 5 is fixed to the first glass plate 3. In this case, the layer 4 made of thermoplastic material and the surrounding frame 6 made of thermoplastic material of the electro-optical functional film 5 are fused together. After lamination, the separation film 8 and the second glass plate 9 are removed from the first layer stack 2 again.

[0075] like Figure 4 As shown, in the next step, a sticky adhesive strip 10 is applied to the first stacking sequence 2. In particular, the sticky adhesive strip 10 is applied in the area of ​​the frame 6 made of thermoplastic material. The sticky adhesive strip 10 can be applied manually, wherein the sticky adhesive strip 10 is preferably applied in an automatic manner by a program-controlled robot arm. The adhesive strip 10 is applied to the frame 6 made of thermoplastic material, for example, by extrusion. Advantageously, the adhesive strip 10 consists of a thermoplastic material, such as polyvinyl butyral (PVB), which is heated (for example to about 200° C.) to achieve high adhesive properties (viscosity) and can be easily applied. Alternatively, for example, thermosetting systems such as cross-linked polyurethane resins can also be used.

[0076] like Figure 53 and 4. The top view of the embodiment of the present invention is shown by way of example and it can be clearly seen that in a vertical view through the first stacking sequence 2, the adhesive strip 10 is arranged in an area of ​​the frame 6 corresponding to the edge area of ​​the first glass pane 3. The adhesive strip 10 is arranged here, for example, approximately in the center of the frame 6 made of thermoplastic material. Except for two interruptions 11 in the adhesive strip 10, the adhesive strip 10 completely surrounds the electro-optical functional film 5. The number of two interruptions 11 is to be understood as an example. A greater or lesser number of interruptions 11 is also possible.

[0077] like Figure 6 As shown, in the next step, the second glass sheet 9 is placed on the adhesive adhesive strip 10 and the distance from the first stacking sequence 2 and thus from the first glass sheet 3 is freely selectable. It is essential that the adhesive strip 10 retains its high adhesive properties until the second glass sheet 9 is placed, so that the distance between the two glass sheets 3, 9 can be set in the desired manner by deformation of the adhesive strip 10. For this purpose, the adhesive strip 10, which here consists of a thermoplastic material, for example, is heated to such a temperature that the high adhesive properties are maintained until the second glass sheet 9 is placed. It is also conceivable to further or continuously heat the adhesive strip 10. Thus, the viscosity of the adhesive strip 10 is set so that the adhesive strip 10 can be applied well and the second glass sheet 9 can be placed by a change in shape. On the other hand, the viscosity of the adhesive strip 10 is set so that it cannot flow and remains in the applied position at least before the second glass sheet 9 is placed.

[0078] The amount of the adhesive strip 10 is preferably arranged such that when the second glass pane 9 is positioned and the distance to the first glass pane 3 is adjusted, the adhesive strip 10 is partially squeezed out between the two glass panes 3, 9. By removing the protruding part of the adhesive strip 10, the edge of the composite glass pane can be made aesthetically appealing in a simple manner. Figure 6 As shown, by placing a second glass pane 9 on the adhesive strip 10 , a second stacking sequence 12 for producing the composite glass pane 1 is produced.

[0079] In the second stacking sequence 12, the second glass sheet 9 is arranged at a certain distance from the first stacking sequence 2 or the first glass sheet 3, wherein there is a non-zero distance between the electro-optical functional film 5 with the frame 6 made of thermoplastic material and the second glass sheet 9, so that a cavity 13 is generated. The cavity 13 is delimited by the electro-optical functional film 5 with the frame 6 made of thermoplastic material, the adhesive strip 10 and the second glass sheet 9. Two interruptions 11 of the adhesive strip 10 form openings 14 into the cavity 13, which is otherwise closed. Figure 6In the embodiment of the present invention, the two openings 14 are not shown in greater detail, which is unnecessary since it is clear how the openings 14 are produced by the interruption 11 of the adhesive strip 10 .

[0080] like Figure 7 As shown, the cavity 13 is then filled with a flowable optically transparent adhesive 15, wherein the optically transparent adhesive is filled into the cavity 13 through one of the two openings 14, while air can escape from the other of the two openings. As a result, the cavity 13 can be completely filled with the optically transparent adhesive 15. The optically transparent adhesive 15 is then cured in the cavity 13, for example by heat and / or UV radiation, so that the two glass plates 3, 9 of the composite glass plate 1 are firmly bonded to each other. In addition, the electro-optical functional film 5 is firmly bonded to the two glass plates 3, 9.

[0081] Figure 7 The composite glass pane 1 according to the present invention is shown as an example. It comprises, in the following order, the first glass pane 3, a layer 4 made of thermoplastic, an electro-optical functional film 5 surrounded by a layered frame 6 made of thermoplastic, an adhesive strip 10 on the layered frame 6, and the second glass pane 9. The adhesive strip 10 surrounds a cavity 13 between the electrically switchable film 5 and the second glass pane 9, which is filled with a cured optically transparent adhesive 15.

[0082] The composite glass panel 1 can be installed in a building or a motor vehicle to separate the interior space from the external environment. The composite glass panel 1 is, for example, a roof glass panel of a motor vehicle. The first glass panel 3 and the second glass panel 9 are each composed of glass, preferably soda-lime glass, and are transparent to visible light. The plastic used in the composite glass panel 1 is preferably composed of polyvinyl butyral (PVB), ethylene vinyl acetate (EVA), thermoplastic polyurethane (TPU) and / or polyethylene terephthalate (PET).

[0083] The outer surface I of the first glass plate 3 faces the external environment and is also the outer surface of the composite glass plate 1. The inner surface II of the first glass plate 3 and the outer surface III of the second glass plate 9 each face the electro-optical functional film 5. The inner surface IV of the second glass plate 9 faces the interior space of the building or vehicle and is also the inner surface of the composite glass plate 1. It should be understood that the composite glass plate 1 can have any suitable geometric shape and / or curvature. As a windshield, the composite glass plate 1 usually has a convex curvature. Preferably, the electro-optical functional film 5 integrated into the composite glass plate 1 is a guest-host film as described above.

[0084] Advantageously, after the optically transparent adhesive 15 has been filled into the cavity 13 , the two openings 14 are closed, for example with the same thermoplastic as used for the adhesive strip 10 .

[0085] It is also advantageous if the distance between the second glass sheet 9 and the first stacking sequence 2 or between the second glass sheet 9 and the first glass sheet 3 is precisely set by one or more spacers. This is not shown in more detail in the embodiments, which is unnecessary because it can be implemented in a simple manner by a person skilled in the art. The optically transparent adhesive 15 used is, for example, a curable casting resin based on acrylate or polyurethane.

[0086] Figure 8 The method according to the invention is described again based on a flow chart. It comprises the following steps in the following order:

[0087] a) providing a first stacking sequence 2 comprising a first glass pane 3, a layer 4 made of thermoplastic and an electro-optical functional film 5 surrounded by a layered frame 6 made of thermoplastic,

[0088] b) forming a second stacking sequence 12 by arranging a second glass sheet 9 on the first stacking sequence 2 with a separating film 8 interposed therebetween,

[0089] c) laminating said second stacking sequence 12 under the action of heat, vacuum and / or pressure,

[0090] d) removing the second glass sheet 9 and the separation film 8 from the laminated second stacking sequence 12,

[0091] e) applying a sticky adhesive strip 10 to the layered frame 6 of the first stacking sequence 2, wherein the adhesive strip 10 continuously surrounds the electro-optical functional film 5 except for at least one interruption 11,

[0092] f) placing the second glass plate 9 on the sticky adhesive strip 10 so that a cavity 13 defined by the adhesive strip 10 is formed between the electro-optical functional film 5 and the second glass plate 9, wherein the at least one interruption 11 of the adhesive strip 10 forms an opening 14 of the cavity 13,

[0093] g) filling the cavity 13 by injecting an optically transparent adhesive 15 into the cavity 13 through the opening,

[0094] h) curing the optically transparent adhesive 15 in the cavity 13.

[0095] From the above statements it follows that the present invention provides an improved method for producing composite glass panes with an integrated electro-optical functional film. The application of pressure to the electro-optical functional film between the two glass panes during the lamination process, which is associated with conventional lamination methods, is avoided. A firm joining of the two glass panes is achieved by filling the cavity with a curable, optically transparent adhesive. The method according to the invention can be implemented in a simple manner in the industrial mass production of composite glass panes. Composite glass panes with an integrated electro-optical functional film can be produced simply and cost-effectively and have a high optical quality.

[0096] List of reference numerals:

[0097] 1 Composite glass panel

[0098] 2 First stacking sequence

[0099] 3. First Glass Plate

[0100] 4 layers made of thermoplastic material

[0101] 5Electro-optical functional film

[0102] 6 Frame made of thermoplastic material

[0103] 7 Incision

[0104] 8 Separation membrane

[0105] 9 Second Glass Plate

[0106] 10 adhesive strips

[0107] 11 Interruption Department

[0108] 12 Second stacking sequence

[0109] 13 Cavity

[0110] 14 Opening

[0111] 15Optically clear adhesive

Claims

1. A method for producing a composite glass panel (1), comprising the following steps: a) providing a first stacking sequence (2) comprising a first glass pane (3), a layer (4) made of plastic and an electro-optical functional film (5) surrounded by a layered frame (6) made of plastic, b) forming a second stacking sequence (12) by arranging a second glass sheet (9) on the first stacking sequence (2) with a separating film (8) interposed therebetween, c) laminating the second stacking sequence (12) under the action of heat, vacuum and / or pressure, d) removing the second glass sheet (9) and the separation film (8) from the laminated second stacking sequence (12), e) applying a sticky adhesive strip (10) to the layered frame (6) of the first stacking sequence (2), wherein the adhesive strip (10) continuously surrounds the electro-optical functional film (5) except for at least one interruption (11), f) placing the second glass plate (9) on the sticky adhesive strip (10) so that a cavity (13) defined by the adhesive strip (10) is formed between the electro-optical functional film (5) and the second glass plate (9), wherein the at least one interruption (11) of the adhesive strip (10) forms an opening (14) of the cavity, g) filling the cavity (13) by injecting an optically clear adhesive (15) into the cavity (13) through the opening, h) curing the optically transparent adhesive (15) in the cavity (13).

2. The method according to claim 1, wherein the at least one opening (14) is closed, in particular by means of a thermoplastic.

3. Method according to claim 1 or 2, wherein at least two, in particular exactly two interruptions (11) of the adhesive tape (10) are provided, which form at least two, in particular exactly two openings (14) of the cavity (13).

4. The method according to any one of claims 1 to 3, wherein the distance between the first stacking sequence (2) and the second glass sheet (9) is set by at least one spacer.

5. Method according to any one of claims 1 to 4, wherein the adhesive tape (10) is applied to the laminar frame (6) by extrusion.

6. Method according to any one of claims 1 to 5, wherein in a vertical view through the first stacking sequence (2), the sticky adhesive strip (10) is applied to the layered frame (6) in the edge region of the first glass sheet (3).

7. A method according to any one of claims 1 to 6, wherein the size of the sticky adhesive strip (10) is designed so that when the second glass plate (9) is arranged on the adhesive strip (10), the adhesive strip (10) is partially pressed out between the first stacking sequence (2) and the second glass plate (9).

8. The method according to any one of claims 1 to 7, wherein the optically transparent adhesive (15) is cured by heat, the action of electromagnetic radiation and / or chemically.

9. The method according to any one of claims 1 to 8, wherein the electro-optical functional film (5) comprises a guest-host film having a functional layer made of a liquid crystal material comprising an embedded additive.

10. The method according to any one of claims 1 to 9, wherein the first glass pane (3) and / or the second glass pane (9) consists of glass, in particular soda-lime glass.

11. The method according to any one of claims 1 to 10, wherein the adhesive adhesive strip (10) comprises or consists of a thermoplastic, in particular polyvinyl butyral (PVB), or a thermosetting plastic, in particular polyurethane. 12 . The method according to claim 1 , wherein the optically transparent adhesive ( 15 ) contains a casting resin, in particular an acrylate or silicone-based casting resin, or consists of the same.

13. Composite glass pane (1), in particular obtained by a method according to any one of claims 1 to 12, comprising in the following order: - a first glass sheet (3), - a layer (4) made of plastic, - an electro-optical functional film (5) surrounded by a layered frame (6) made of plastic, - an adhesive strip (10) on the lamellar frame (6), - a second glass sheet (9), The cavity (13) is defined by the electro-optical functional film (5), the second glass plate (9) and the adhesive strip (10), and the cavity is filled with a cured optically transparent adhesive (15).

14. Use of a composite glass pane (1) according to claim 13 in buildings or in land, air or water vehicles, in particular motor vehicles, for example as a windshield, rear window, side window and / or roof window.

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