DE102013214553A1 - Method for sealing a side region of a film stack, film stack and laminated glass pane - Google Patents

Abstract

The present invention relates to a method for sealing a side region (11) of a film stack (10) for a switchable laminated glass pane (30), the film stack (10) comprising at least one switchable film layer (13) and two carrier films (12), wherein the switchable film (13) is arranged between the carrier films (12). Furthermore, the invention relates to a film stack (10) for a switchable laminated glass pane (30), comprising at least a switchable film layer (13) and two carrier films (12), wherein the switchable film (13) is arranged between the carrier films (12) and a switchable Laminated glass pane (30), wherein the laminated glass pane (30) has a laminate at least two glass panes (31) with a film stack (10) arranged therebetween.

Description

The present invention relates to a method for sealing a side region of a film stack for a switchable laminated glass pane, wherein the film stack has at least one switchable film layer and two carrier films and the switchable film is arranged between the carrier films. The invention further relates to a film stack for a switchable laminated glass pane, at least comprising a switchable film layer and two carrier films, wherein the switchable film is arranged between the carrier films, and a switchable laminated glass pane, wherein the laminated glass pane has a laminate of at least two glass panes with a film stack arranged therebetween ,

STATE OF THE ART

The use of switchable laminated glass panes makes it possible, inter alia, to create panes with controllable or switchable variable light transmission properties. Such laminated glass panes are used in the automotive industry, for example, to enable the user of a vehicle to be able to selectively switch a sunroof of the vehicle transparent or opaque.

Such switchable laminated glass panes are realized in particular as a laminate of a film stack between two glass panes. The light transmission of the laminated glass pane is controlled by driving the film stack. Such a film stack in turn has a switchable film layer which is arranged between carrier films. The problem with this is that chemicals can penetrate or diffuse into the film stack via side regions of such a film stack, which damage the switchable film layer and can destroy it in the worst case. Damage to the switchable film layer is also possible by outdiffusing components of the switchable film layer at lateral regions of the film stack. Furthermore, by such diffusion processes also aesthetic disadvantages, such as areas that are constantly opaque, arise.

In the EP 2 013 013 B1 and the US 2012/0176656 A1 , both of which show laminated laminated glass, this problem is solved by providing the switchable film with a frame of non-switchable optically inactive material to seal the switchable film against side portions of the film stack. However, this area of the frame can not be addressed accordingly. In order to safely prevent diffusion into or out of the switchable film, the frame must have a sufficient extent. Distances between the outer edge of the film stack and the beginning of the switchable film of 40 mm or more may be necessary for this. This represents a major limitation for the usability of such composite glass panes, since a non-controllable edge region is unavoidable and the transmission in this edge region can not be changed thereby.

An alternative way of sealing or sealing is from the WO 2009/153 593 A1 known and in 1 shown. It is schematically a foil stack 10 shown a switchable film layer 13 which is between two carrier films 12 is arranged. The switchable foil layer 13 again has a transmissive single film 15 between two conductive single foils 14 on. By applying an electrical voltage to the conductive individual foils 14 can the light transmission of the transmissive single film 15 be selectively changed. By building a laminated glass as a laminate of such a film stack 10 between glass panes a switchable laminated glass pane can be realized. At the side area 11 of the film stack 10 is the danger of diffusion described above 100 from or into the switchable film layer 13 indicated by an arrow. According to the WO 2009/153593 A1 is therefore intended a cover 101 to provide, here on another side area 11 of the film stack 10 presented before the final attachment. The cover element 101 comes with adhesive material 102 at the film pile 10 attached. This has the disadvantage that, although a direct application of the adhesive material 102 on the page area 11 of the film stack 10 is avoided, chemicals from the adhesive material 102 in the switchable film layer 13 can diffuse. Furthermore, the arrangement of the cover is 101 on the side area 11 in the mass production very complex and must, especially with a complicated geometry of the film stack 10 , be made manually. This requires a high cost factor in the production of such a film stack 10 , Furthermore, in the area of the necessary contacts, the switchable film layer is 13 a diffusion-tight application of the cover 101 often not possible.

DISCLOSURE OF THE INVENTION

It is therefore an object of the invention to at least partially overcome the above-described disadvantages of known sealing methods for side areas of film stacks. In particular, it is an object of the present invention to provide a method for sealing a side region of a film stack for a switchable laminated glass pane, a film stack for a switchable Laminated glass and a switchable laminated glass provide that improve the sealing of a side portion of a film stack in a simple and cost-effective manner, and in particular allow an automated implementation of the seal and / or enlargement of the actively switchable surface of the film stack.

The above object is achieved by a method for sealing a side region of a film stack for a switchable laminated glass pane having the features of independent claim 1, by a film stack for a switchable laminated glass pane having the features of independent claim 10 and by a switchable laminated glass pane having the features of the claim 15. Further features and details of the invention will become apparent from the dependent claims, the description and the drawings. In this case, features and details that are described in connection with the method according to the invention apply, of course, also in connection with the film stack according to the invention and the laminated glass according to the invention and in each case vice versa, so that with respect to the disclosure of the individual aspects of the invention always reciprocal reference is or may be.

In a first aspect of the invention, the object is achieved by a method for sealing a side region of a film stack for a switchable laminated glass pane, the film stack at least comprising a switchable film layer and two carrier films, wherein the switchable film is arranged between the carrier films. In particular, the method is characterized in that a diffusion-tight seal is produced in and / or on the side region of the film stack by a laser welding process.

By means of the switchable film layer, which may in particular have electrically conductive individual films and at least one individual film with controllably variable light transmission properties, it is possible to achieve a controllably changeable transparency of the laminated glass pane after lamination of the film stack with glass panes to form a laminated glass pane. In the side region of the film stack, which may in particular also be formed by an end face of the film stack and / or, in which compared to the flat extent very small thickness of the film stack, can also form an edge of the film stack, it is possible that the individual films of the film stack are accessible from the outside. For the switchable film, in particular for an optically active and responsible for the change in the transmission part of the switchable film, this entails the danger that the functionality of the switchable film can be limited or even destroyed by diffusion of substances in or out of the switchable film. Also, these diffusion processes can lead to undesirable visible changes in the film stack.

By a laser welding process, it is particularly easy to seal a side portion of the film stack. In this case, the material that subsequently forms the seal is locally heated by the laser and at least partially melted. In particular, by means of the laser in and / or on the side region, the material subsequently forming the seal can be locally heated and / or at least partially melted such that all the individual foils present in the side region of the film stack, and of course also the entire side region of the film stack of the covered seal are covered. After cooling, the previously at least partially melted material is solidified again, thus forming the seal. Due to the resulting sealing, diffusion into or out of the film stack, in particular from the switchable film layer of the film stack, can be reliably avoided. Such a seal by a laser welding method can be carried out in particular also automated. In addition, the switchable film can extend to the side area and thus to the edge of the film stack, whereby an ideal utilization of the available area can be achieved. Overall, in particular by the possibility of automation, by the method according to the invention a particularly favorable and at the same time less time-consuming sealing of side regions of a film stack for a switchable laminated glass pane can be achieved.

In a method according to the invention, it may be particularly preferable for the carrier foils to be welded together by the laser. The carrier films preferably form the two outermost films of the film stack. For example, they can be made of polyethylene terephthalate (PET), a material with well known thermoplastic properties. By welding these two films of the film stack thereby automatically all intervening films, and thus in particular the vulnerable especially by diffusion processes switchable film layer, enclosed and sealed. A welding of the two carrier films thus represents a particularly simple way of realizing a diffusion-tight sealing of a side region of a film stack by means of a laser welding method.

In this case, a method according to the invention can be further developed in such a way that the individual layers of the film stack are arranged before welding in such a way that the film stack in the Side area has only the two carrier films. In this development, it is particularly easy to weld only the carrier films together. During welding, the two carrier foils are heated by the laser until they fuse together. Due to the absence of other individual foils between the carrier foils, which is ensured by the special arrangement, particular care must be taken not to these other individual foils during welding. This represents a simplification of the method according to the invention.

Alternatively or additionally, it can be provided in a method according to the invention that during welding of the carrier films, the individual layers of the film stack are removed in the side region except for the two carrier films by the laser. This further development is particularly applicable to film stacks whose switchable film evaporates or burns already at temperatures or laser intensities at which the carrier films melt. This may be the case with switchable films based on polymer electronics such as organic semiconductors. When welding, the entire film stack is heated by the laser until only the carrier foils are present, which then merge together. By vaporizing or burning the other individual films between the carrier films, a special consideration of these other individual films is also not required. This also represents a simplification of the method according to the invention.

Alternatively, a method according to the invention can be configured in such a way that, prior to welding, a sealing element is arranged on the side region of the film stack, which is in each case welded in a diffusion-tight manner to the carrier films. Of course, in this case, the sealing element itself is also formed diffusion-tight and preferably has a small thickness in order not to increase the thickness of the film stack in the edge region substantially. The sealing element is welded according to the invention with two carrier films. Since the two carrier films each form the upper and the lower end of the film stack and the sealing element is diffusion-tightly connected to both carrier films by the laser welding process, this results in a diffusion-tight sealing of the entire film stack. The sealing element can be arbitrarily shaped and thus adapted to any possible geometry of a side region of a film stack. A particularly variable sealing of a side region of a film stack is thereby made possible.

Furthermore, it can be provided in a further development of a method according to the invention that the sealing element is U-shaped and is pushed onto the film stack before welding. This represents a particularly simple form of the sealing element. By pushing the sealing element is already held on the film stack before welding. An additional fixation during welding can be omitted. Especially for flat film stacks with straight side regions, a U-shaped sealing element represents the simplest and preferred type of sealing elements, both in the positioning of the sealing element on the film stack and for the subsequent sealing by the laser welding.

Alternatively, a method according to the invention may be configured in such a way that the sealing element has a first and a second subelement, wherein during welding the first subelement is welded to the upper carrier layer, the second subelement to the lower carrier layer and the two subelements are welded together in a diffusion-tight manner. In particular for geometries of a side region of a film stack which are not plane and / or straight, this embodiment of a sealing element is advantageous. The first sub-element is applied to the carrier film at the top of the side region of the film stack, the second sub-element to the carrier film at the bottom of the side region of the film stack. The application may in particular preferably take place such that the two partial elements project beyond the side region of the film stack. Subsequently, the two sub-elements are each welded to the carrier film, to which they are applied, and mutually diffusion-tight by the laser. Since the two carrier films in turn each form the upper and the lower end of the film stack and the partial elements of the sealing element are diffusion-tightly connected to both carrier films and each other by the laser welding process, so results in a diffusion-tight seal of the entire side region of the film stack. As a result of the flexibility of the geometry of the two partial elements, complicated and in particular also three-dimensional and not only flat-running side regions of foil stacks can be securely sealed diffusion-tight.

Furthermore, it can be provided in a method according to the invention that after the welding in the side region, a conductive layer of the film stack is destroyed by laser irradiation. In particular, in the presence of a plurality of individual conductive films in the film stack may occur in a laser welding process that the individual conductive individual foils are connected to each other during the sealing process conductively to a short circuit. To fix this, it can According to the invention be provided that after sealing by another laser irradiation precisely these shorts by destroying the conductive layer preferably directly destroy or separate them at least by destruction of the conductive layer of the remaining film stack. As a result, the rejects during the production of the film stack can be significantly reduced, thereby reducing production costs.

In a preferred further development of a method according to the invention, it can further be provided that the same laser is used for the laser welding method and for destroying the conductive layer. This can be done by adjusting the laser, such as changing the focus of the laser or reducing the power. In this way, a separate laser for destroying the conductive layer is not required and only one laser can be used in the production of a film stack. In this way, further costs can be saved.

According to a second aspect, the object is achieved by a film stack for a switchable laminated glass pane, at least comprising a switchable film layer and two carrier films, wherein the switchable film is arranged between the carrier films. In particular, a film stack according to the invention is characterized in that a side region of the film stack is sealed in a diffusion-tight manner by a laser welding process.

The switchable film layer, which in particular has electrically conductive individual films and at least one individual film with controllably variable light transmission properties, makes it possible, after lamination of the film stack with glass panes to form a laminated glass pane, to control the translucent transparency of the laminated glass pane. Individual sheets of the film stack may be accessible in the side area of the film stack. In particular for the switchable film and its optically active and responsible for a change in the transmission parts, this includes the risk that substances diffuse into or out of the switchable film. This can limit or even destroy the functionality of the switchable film. Even unwanted visible changes in the film stack may be a consequence of these diffusion processes.

By laser welding a side portion of the film stack is sealed diffusion-tight. In this case, it is preferable to ensure that the entire side region of the film stack is sealed by the welding in particular without interruption. In particular, an automated laser welding process is also easy to implement. As a result, a reduction of costs and duration can be achieved in the production of a film stack according to the invention. Furthermore, the switchable film can extend to the side area and thus to the edge of the film stack, whereby an ideal utilization of the available area can be achieved. By using a film stack sealed in a diffusion-tight manner by laser welding, diffusion from or into the film stack, in particular into the switchable film of the film stack, can be reliably avoided. The described problems caused by diffusion can be reliably avoided by the use of a film stack according to the invention. A secure, durable use of a film stack according to the invention, in particular in a switchable laminated glass pane, can be achieved in this way.

According to a particularly preferred further development of a film stack according to the invention, it can be provided that the side region of the film stack is sealed by a method according to the first aspect of the invention. All the advantages that have been described for a method for sealing a side region of a film stack according to the first aspect of the invention therefore naturally also arise for a film stack according to the invention whose side region is sealed by such a process.

In addition, a film stack according to the invention can be developed to the effect that the side region of the film stack is a circumferential side region. Circumferential within the meaning of the invention means in particular that all side regions of the film stack, in which different films of the film stack are accessible from the outside, are sealed. As a result, it can be ensured that diffusion into and / or out of the individual individual films, in particular into and / or out of the switchable film layer, can be avoided. An even greater security for the film stack against impaired functioning by diffusion processes can be achieved.

Furthermore, in a film stack according to the invention be provided that the switchable film layer has a plurality of individual films. This may have the advantage that preferably each of the individual films is provided only for one task in the film stack, for example, only for the power supply or the transmission change. Each of the individual films can be made simpler, which in particular a reduction of the error rate and also the manufacturing cost can be achieved.

According to a preferred further development of a film stack according to the invention, it can further be provided that the switchable film layer has at least one conductive individual film and a single film with light transmission variable by activation. The at least one conductive individual film may have as the electrically conductive material preferably a transparent electrically conductive material, for example indium tin oxide. The switchable film layer preferably has a single film with light transmission which can be varied by activation, which is arranged between two conductive individual films. The individual foils can then be connected in such a way that one of the conductive individual foils forms a first, the other a second electrical connection of the switchable foil layer. A particularly simple control of the transmissive single layer and thus controlled by this change in the transmission is possible.

According to a third aspect, the object is achieved by a switchable laminated glass pane, wherein the laminated glass pane has a laminate of at least two glass panes with a film stack arranged therebetween. In particular, a laminated glass pane according to the invention is characterized in that the film stack is formed according to the second aspect of the invention. All the advantages which have been described for a film stack for a switchable laminated glass pane according to the second aspect of the invention thus naturally also result for a laminated glass pane according to the invention which has such a film stack.

PREFERRED EMBODIMENTS

The inventive method and its developments and advantages thereof are explained in more detail with reference to drawings. Each show schematically:

2 a film stack with protruding carrier films before the laser welding,

3 a film stack with laser-welded carrier films,

4 a film stack with two variants of a sealing element,

5 another view of a film stack with a sealing element and

6 a section of a laminated glass pane.

Elements with the same function and mode of action are in the 1 to 6 each provided with the same reference numerals.

The 2 shows a section through a film stack according to the invention 10 before the laser welding of the two carrier films 12 , The film pile 10 has a switchable film layer 13 on, between two carrier foils 12 is arranged. The switchable foil layer 13 again has a transmissive single film 15 on that between two conductive single sheets 14 is arranged. The carrier foils 12 and the conductive single foils 14 are preferably made of a transparent material and / or have a geometry that the light transmission through the film stack 12 little or not influenced. By applying a voltage difference to the two conductive individual foils 14 is a driving of the transmissive single film 15 and thus controlled changing the transmissivity of the entire film stack 10 possible. When using such a film stack 10 in a laminated glass pane 30 (not shown), the laminated glass can be equipped with a variable transmission.

Particularly problematic for the stability and longevity of such a film stack 10 are the page areas 11 , At these it is possible that by diffusion processes 100 (not shown) in and / or out of the film stack 10 , in particular from the switchable film layer 13 of the film stack 10 , this is damaged. In this case, the damage of purely visual, visible changes up to a complete destruction of the film stack 10 , both functional and structural. To such a diffusion 100 To safely prevent is inventively provided that in and / or on the side area 11 of the film stack 10 a diffusion-tight seal is produced by a laser welding process. As preparation for this laser welding are present in the individual films 14 . 15 the switchable film layer 13 opposite the carrier foils 12 set back. This can impair the switchable film layer 13 be ensured when performing the laser welding.

In 3 is the foil pile 12 out 2 shown after the laser welding of the carrier foils 12 has been carried out. The two carrier foils are now laser-welded 20 connected with each other. In particular, the laser welding poses 20 together with the carrier foils 12 a diffusion-tight seal of the side area 11 of the film stack 10 dar. A diffusion 100 (not shown) in or out of the film stack 10 , in particular from the switchable film layer 13 , can be safely avoided. The laser welding 20 In this case, in particular automated, whereby the for the production of a film stack according to the invention 10 required time and the costs incurred can be minimized.

4 shows a section through another film stack 10 , in turn, carrier foils 12 and one of conductive single foils 14 and a transmissive single film 15 existing switchable film layer 13 consists. At the two side areas 11 of the film stack 10 is each a sealing element 16 arranged, wherein the sealing elements already by laser welding 20 with the carrier foils 12 and partially interconnected. As a result, both are side panels 11 of the film stack 10 already sealed diffusion-tight.

On the right side is a U-shaped sealing element 16 shown. It was on the foil stack before welding 10 deferred and then by two laser welding 20 diffusion-tight with the respective adjacent carrier film 12 welded. As particularly preferred also the material of the sealing element 16 prevents diffusion, this provides a particularly simple way of diffusion-tight sealing of a side area 11 a film stack 10 represents.

On the left is an alternative embodiment of a sealing element 16 shown, wherein the sealing element 16 a first 17 and a second subelement 18 having. This embodiment of a sealing element 16 especially when not planning, three-dimensional geometries of a page area 11 a film stack or be beneficial, for example, a plugging a U-shaped sealing element 16 would be disadvantageous for production reasons. This also in this embodiment of a sealing element 16 a diffusion-tight seal of the side area 11 of the film stack 10 can be achieved is another laser welding 20 required that the two sub-elements 17 . 18 combines.

Also by the use of a sealing element 16 can a diffusion 100 (not shown) in or out of the film stack 10 , in particular from the switchable film layer 13 safely avoided. The laser welding 20 In this case, in particular, it can also be automated, whereby the production of a film stack according to the invention 10 required time and the costs incurred can be minimized.

5 shows a plan view of a film stack according to the invention 10 whose edge area 11 through a sealing element 16 sealed diffusion-tight. Shown is the variant that the sealing element 16 from two subelements 17 . 18 exists, with only the subelement 17 is visible. The subelement 17 is designed like a frame, whereby the film stack 10 or the upper carrier film 12 at least partially visible. The edge of the film stack 10 and thus the side area to be sealed 11 is dashed below the subelement 17 indicated. Furthermore, the electrical contacts 19 and dot-dash their course under the subelement 17 until the film pile 10 shown. Clearly visible are two laser welds 20 , where the internal laser welding 20 between the first subelement 17 and the upper carrier sheet 12 , the outer laser welding 20 the two subelements 17 . 18 combines. In particular, it is clearly visible that the two laser welds without interruption the entire film stack 10 surround. Thus, a complete diffusion-tight seal of the side area 11 of the film stack 10 be ensured.

In 6 is a laminated glass pane according to the invention 30 shown. The laminated glass pane 30 is essentially a laminate of two glass panes 31 with a film stack according to the invention arranged between them 10 educated. Through the film pile 10 , Especially when using a transmissive single film 15 (without reference numeral) in the film stack 10 , It is possible the light transmission capability of the entire laminated glass pane 30 targeted and switchable to change. The film pile 10 can, as shown, to the edge of the laminated glass pane 30 can be arranged without a restriction in the functionality, in particular the switchable film layer 13 (without reference) occurs. By using a film stack according to the invention 10 is it possible to use a laminated glass pane 30 provide, whose functionality is particularly high security. An impairment or even destruction of the film stack 10 and thus the entire laminated glass pane 30 , by diffusion can by the use of a film stack according to the invention 10 safely avoided. At the same time can by the possibility of high automation in the production of a film stack according to the invention 10 and thus also a laminated glass pane according to the invention 30 , the production costs and the time required for it are lowered.

LIST OF REFERENCE NUMBERS

10

film stack

11

page range

12

support film

13

switchable film layer

14

conductive single foil

15

transmissive single foil

16

sealing element

17

first subelement

18

second subelement

19

electric contact

20

laser welding

30

Laminated glass

31

pane

100

diffusion

101

cover

102

adhesive material

QUOTES INCLUDE IN THE DESCRIPTION

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

Cited patent literature

• EP 2013013 B1 [0004]
• US 2012/0176656 A1 [0004]
• WO 2009/153593 A1 [0005, 0005]

Claims (15)

Method for sealing a page area ( 11 ) of a film stack ( 10 ) for a switchable laminated glass pane ( 30 ), the film stack ( 10 ) at least comprising a switchable film layer ( 13 ) and two carrier films ( 12 ), wherein the switchable film ( 13 ) between the carrier films ( 12 ), characterized in that in and / or on the side region ( 11 ) of the film stack ( 10 ) is produced by a laser welding method, a diffusion-tight seal. Method according to claim 1, characterized in that the carrier foils ( 12 ) are welded together. Method according to claim 2, characterized in that the individual layers ( 12 . 13 ) of the film stack ( 10 ) are arranged before welding in such a way that the film stack ( 10 ) in the page area ( 11 ) only the two carrier foils ( 12 ) having. Method according to one of claims 2 or 3, characterized in that during welding of the carrier films ( 12 ) the individual layers ( 12 . 13 ) of the film stack ( 10 ) in the page area ( 11 ) except for the two carrier foils ( 12 ) are removed by the laser. A method according to claim 1, characterized in that before welding on the side region ( 11 ) of the film stack ( 10 ) a sealing element ( 16 ) arranged with the carrier foils ( 12 ) is welded in each case diffusion-tight. Method according to claim 5, characterized in that the sealing element ( 16 ) Is U-shaped and before welding to the film stack ( 10 ) is postponed. Method according to claim 5, characterized in that the sealing element ( 16 ) a first ( 17 ) and a second subelement ( 18 ), wherein during welding, the first sub-element ( 17 ) with the upper carrier layer ( 12 ), the second subelement ( 18 ) with the lower carrier layer ( 12 ) and the two subelements ( 17 . 18 ) are welded together diffusion-tight. Method according to one of the preceding claims, characterized in that after welding in the side area ( 11 ) a conductive layer ( 14 ) of the film stack ( 10 ) is destroyed by laser irradiation. A method according to claim 8, characterized in that for the laser welding process and for the destruction of the conductive layer ( 14 ) the same laser is used. Film pile ( 10 ) for a switchable laminated glass pane ( 30 ), at least comprising a switchable film layer ( 13 ) and two carrier films ( 12 ), wherein the switchable film ( 13 ) between the carrier films ( 12 ), characterized in that a side region ( 11 ) of the film stack ( 10 ) is sealed diffusion-tight by a laser welding process. Film pile ( 10 ) according to claim 10, characterized in that the side area ( 11 ) of the film stack ( 10 ) is sealed by a method according to any one of claims 1 to 9. Film pile ( 10 ) according to one of claims 10 or 11, characterized in that the side region ( 11 ) of the film stack ( 10 ) a circumferential side area ( 11 ). Film pile ( 10 ) according to one of claims 10 to 12, characterized in that the switchable film layer ( 13 ) several individual films ( 14 . 15 ) having. Film pile ( 10 ) according to claim 13, characterized in that the switchable film layer ( 13 ) at least one conductive single foil ( 14 ) and a single foil ( 15 ) having controllable by light transmission. Switchable laminated glass pane ( 30 ), the laminated glass pane ( 30 ) a laminate of at least two glass panes ( 31 ) with an interposed film stack ( 10 ), characterized in that the film stack ( 10 ) is designed according to one of claims 10 to 14.

Images