EP3265306A1

EP3265306A1 - Composite film

Info

Publication number: EP3265306A1
Application number: EP15756887.4A
Authority: EP
Inventors: Lambert Nekula; Martin Kornfeld; Adolf Schedl; Harald Gruber
Original assignee: Constantia Teich GmbH
Current assignee: Constantia Teich GmbH
Priority date: 2015-03-04
Filing date: 2015-08-24
Publication date: 2018-01-10
Also published as: CA2978498A1; US20180037010A1; WO2016138967A1

Abstract

A composite film (20) comprises at least one backing film (1) made of a backing material (8), at least one barrier layer (2) made of a barrier film (9) and at least one laminating adhesive layer (3) therebetween. On the side of the barrier layer (2) away from the backing layer (1), the composite film (20) has a raised pattern (31), and in the area of the raised pattern (31), the barrier layer (2) has stretched stretching regions (6) relative to the non-stretched barrier film (9). In the area of the raised pattern (31), the barrier layer (2) has on the side facing the backing layer (1) surfaces that are not joined to the backing layer (1).

Description

composite film

The invention relates to a composite film having at least one carrier layer made of a carrier material, at least one barrier layer comprising a barrier film and at least one intermediate laminating adhesive layer, and a process for producing this composite film.

Furthermore, the invention relates to a device for producing such a composite film, wherein the device comprises a carrier material feed, a laminating adhesive application, a barrier film feed and a pressing device, wherein at least the carrier layer, the laminating adhesive layer and the barrier film are pressed against each other by the pressing means for laminating at least partially.

The invention further relates to a process for producing such a composite film.

Composite films of this type are used in many fields of application. The carrier layer can be made, for example, of paper or another porous or non-moisture-resistant material that receives a sealing property through the barrier layer. Alternatively, the carrier layer itself may have barrier properties, as may be the case with coated metal foils, in particular with aluminum foils, which themselves have barrier properties and are additionally coated with a barrier material. In this case, it is not necessary for the barrier layer itself to have barrier properties. The terms "backing layer", "backing material", "barrier layer" and "barrier film" are used in the context of the description only for the sake of clarity and distinctness and are, unless expressly stated, not restrictive or as an indication of certain inherent properties interpreted.

In the context of the present description, the terms "carrier material", "barrier film" and "laminating adhesive" are generally used to designate the starting material from which the layers of the composite film are constructed. Laminating adhesive layer "generally refers to a layer of the corresponding materials that is already part of, or is being processed into, a composite film. However, the distinction between carrier material and carrier layer, barrier layer and barrier film or laminating adhesive layer and laminating adhesive are only for better understanding and this distinction is not restrictive interpret. The barrier film is usually made of a plastic material, wherein polyester is preferably used in many cases due to the good processability, tightness and food safety in many cases. The barrier film is usually laminated or laminated to the paper, using dry-type laminating adhesive, wet-laminating adhesive, extrusion laminating adhesive or solvent-free adhesive systems.

For numerous applications, the composite film is punched or cut after its production, for example for the production of boards, which are used as lids for containers, in particular for finished food packaging. The use of composite films makes it possible, for example, to produce lightweight and cost-effective circuit boards which can at least replace the previously used aluminum circuit boards. Metal-free circuit boards also allow the use of metal detectors for quality and safety control of sealed packaging. Optionally, the composite films may additionally comprise a metal layer, in particular of an aluminum foil, in order to improve the barrier properties, but this is not necessary in many cases. In connection with the subject description, a "cover plate" is a cover element punched out of a foil material and used to close a container the hold of the board on the container via an additional cover element or form-fitting, for example by flipping the edges of the board, can be ensured.

Single-sided coated composite films (and generally unsymmetrical composites) have proved to be disadvantageous or unusable when used as a circuit board material, because due to the different material properties of substrate and barrier layer, the board can bulge after punching or cutting, which is also called "keying" or "curling" is called. This tiling occurs in particular when the carrier layer contracts more strongly after lamination than the barrier layer, which may be the case in particular with a carrier layer of paper. The extent of the tapping is influenced by many factors; in the case of a paper / plastic composite, in particular the moisture of the paper layer is a significant influencing variable; in other composites, for example aluminum / plastic composite, in particular temperature differences and internal tensions of the materials used are a drawback. The more different the physical properties of the materials, the more difficult it is to get to grips with the problems of concealment. To prevent tipping, the composite films can be made with a symmetrical layer profile, such as by applying an identical barrier layer on both sides of the substrate. This increases both the material costs and the costs for the production plants, since the lamination process must be carried out in duplicate.

The blanks are stacked after stamping or cutting and fed to a separation device for further processing. This dicing device usually lifts the top board by means of a suction device and places it on the package to be sealed, where it is then generally sealed to the package with a sealing tool. On the one hand, the lifting of the top board is only possible if the boards in the stack are not curved but flat, on the other hand occurs especially in very smooth, for example, coated on both sides of the circuit board, the undesirable effect that the top board when lifting due to the negative pressure at the underlying The board sticks so that two or more boards are lifted off the suction device at the same time. This problem is referred to in the art as "glass pane effect." To avoid this, it is known in conventional boards, on one side of the board, for example, on the non-printed side, spacers, such as raised dots or patterns, provide or the board with However, the thinner and lighter the board is, the more the problem of interlocking boards arises, and the bowing effect can be exacerbated by the use of thin composites, but environmental and logistical considerations are desirable To make boards as thin and light as possible.

It is an object of the subject invention to provide a composite film of the type mentioned, which does not necessarily have to be coated symmetrically on both sides and yet avoids the disadvantages of the prior art.

These and other objects are achieved by a composite film of the type mentioned, in which the composite film on the side facing away from the carrier layer of the barrier layer has a raised pattern, wherein the barrier layer in the region of the raised pattern with respect to the unstretched barrier film has stretched stretching areas, and wherein the barrier layer in the region of the raised pattern on the side facing the carrier layer has surfaces which are not connected to the carrier layer. These raised patterns thus represent spacers which prevent sticking together during singulation. In addition to this functionality, it is possible to create a haptic / visual decorative layer by specifying a pattern with which the expansion areas are introduced into the barrier layer create. The sliding properties can also be influenced by the elevations, for example by the raised pattern forming elongated "slideways" on the composite material that define a sliding direction Such slideways can be arranged on the inside of pouches, for example, to facilitate the pouring of the contents For example, the raised pattern may also impart anti-slip properties to the composite on the barrier layer side.

The term "surfaces which are not connected to the carrier layer" designates surface regions in which there is no or only a negligible adhesion effect with respect to the carrier layer This is the case, in particular, for surfaces that are not in contact with the laminating layer, which are on another Area of the same barrier layer is applied (ie, the surfaces are inside a fold together), or surfaces that are in contact with the laminating adhesive, but where the laminating adhesive causes no or only a negligible or non-effective adhesion to the support layer This may be the case, for example, if laminating adhesive is present between the surfaces of the barrier layer which lie adjacent to one another in the interior of a fold, but this does not cause adhesion of the surfaces to the carrier layer. Surfaces which are not connected to the carrier layer generally form the surface of the carrier In this area, the areas of the barrier layer facing the carrier layer generally do not run parallel to the surface of the carrier layer.

The term "raised" in the context of the present description refers to the "normal" surface of a flat composite foil, that is to say a composite foil whose thickness corresponds to the sum of the thicknesses of its individual layers. In the context of the present description, a "raised pattern" is considered to be a regular, irregular pattern, in the region of which the surface has an elevation in relation to the "normal" surface.

In a preferred embodiment, the surfaces of the layer of the barrier layer which are not connected to the carrier layer can at least partially adjoin one another of the side of the barrier layer facing the carrier layer. This minimizes the volume of cavities between the carrier layer and the barrier layer.

Advantageously, the raised pattern can correspond to a stretch pattern at Dehnbereichen. This allows easy production of the composite film with a well-defined raised pattern. In connection with the subject disclosure, the term "stretch pattern" denotes the entirety of the regions of the barrier film in which the barrier layer As compared to the unstretched barrier film, it has a deliberately introduced stretch, for example by means of embossing or vacuum rolls.

In a further advantageous embodiment, the expansion regions can form stress compensation zones which compensate for strain-induced stresses between the layers. According to the invention, these stress compensation zones can be designed as folds or lifts of the barrier film running along the composite film, which extend along the elongation pattern. The folds or lifts can be with each change in the area ratios between the carrier layer and barrier layer, for example due to environmental influences such as moisture and / or temperature, pull apart or collapse and thus compensate for the resulting stresses. As a result, the occurrence of a bowl is effectively prevented even in changing weather conditions and it is possible to punch out even from a very thin composite foil boards. The convolutions minimize voids or cavities that may exist between the barrier layer and the carrier layer, and it is easy to generate a defined raised pattern on the surface of the board on the side of the barrier layer.

By "lift off" is meant a region in which the barrier film is not in contact with, i.e., lifted from, the liner layer.

The stretch pattern may be a regular or an irregular pattern, whereby a visually appealing design is possible. The stretch pattern can be formed, for example, as a number of parallel lines or double lines. On the other hand, pictorial patterns or a simple or regularly repeating logo or mark may also form the stretch pattern.

The inventors have found in experiments that composite films can also be produced whose raised patterns surprisingly differ significantly from the stretch patterns introduced into the barrier film and take up forms which also extend between the regions of the elongation pattern. Advantageously, therefore, the raised pattern of the Dehnmuster may at least partially differ. Corresponding methods and devices for producing such composite films are described in detail below.

Advantageously, the raised pattern may be a net-like pattern. The structures of the net-like pattern generally extend between regions of the elongation pattern, for example from a round, closed expansion region to a round, closed expansion region arranged at a distance from the latter. The The structure of such a net-like raised pattern covers the surface of the composite film in a blanket-like manner, so that when it is wound into a roll, the film does not form over-built-up areas and uniform winding is ensured over the entire roll surface. The same effect also applies to the boards punched out of the composite film. This improves the behavior when separating the boards.

Advantageously, the raised pattern on the surface of the composite foil can have an elevation h, wherein the ratio h / d of the elevation h to the summed thickness d of the individual material layers in the composite foil is less than 10 and preferably less than 5, and in particular has a value of about 0.05 to 2, for example about 0.1 to 2. The term "summed thickness d" is understood to mean the thickness of the individual materials contained in the composite film without consideration of elongation and empty spaces, for example, the thickness d can be measured as the thickness of the composite film in the regions outside the extension regions Differences between the thickness d and the maximum thickness of the composite film in the Dehnbereichen (including any voids) The summed thickness d of the composite film, depending on the requirements and material combination, for example, between 1 1 μηη and 230 μηη, preferably between 14 μηη and 140 μηη amount.

In a further advantageous embodiment, the carrier layer can be coated over its entire surface with the laminating adhesive layer. A full-surface lamination facilitates the manufacturing process. Alternatively, a partial, non-continuous lamination may be provided, wherein the lamination can be recessed, for example, in the Dehnbereichen or in parts thereof.

In a further advantageous embodiment, the composite film may have a coating layer. The coating layer may, for example, be an additional sealing layer which is applied to the composite film on the side of the barrier layer, for example if the material of the barrier film itself is not sealable. Surprisingly, it has been found by the inventors that the barrier layer underlying the coating layer, with the stress compensation zones provided therein, effectively prevents the composite film from being wiped even when the overlying coating layer forms a continuous layer. This is the case even if the same composite film with the coating layer but without the barrier layer (or with a barrier layer but without stress compensation zones) would lead to very strong disharmony effects.

Advantageously, the carrier layer may be printed on the side facing away from the barrier layer and / or facing. By printing on the side of the barrier In the case of a transparent, transparent or translucent barrier layer, a combination of printing patterns and patterns of the stress compensation zones can be achieved. In this case, a coloring or a separate pattern of the barrier layer can be taken into account for the overall impression of the finished surface. Preferably, as the side facing away from the barrier layer, the smooth and high-quality side of the carrier material is used in order to obtain a good printed image on the outside of the board visible to the consumer. In combination, numerous design and effect options can be achieved.

Furthermore, it is also possible to print on the barrier layer. For example, a mirror pressure may be applied to the side of the barrier layer facing the carrier layer.

According to the invention, the carrier material may be selected from a fiber material, such as paper or cardboard, in particular paper or recycled paper having a thickness between 20 μηη and 150 μηη, preferably between 40 μηη and 90 μηη, a metal foil, such as an aluminum foil with a thickness between 5 μηη and 40 μηη, preferably between 8 μηη and 25 μηη, or of a plastic material, such as polyester or other plastics, for example, those plastics that can be used for the barrier film. The plastic material may, for example, have a thickness of 5 to 50 μm, preferably between 12 and 30 μm. Particularly preferred is a thickness of about 23 μηη. In fact, the invention can be applied to any composite films in which bowl effects can occur.

The barrier film may, for example, have a thickness of about 5-80 μm, preferably of 6-50 μm. The material of the barrier film may preferably be selected from polyesters, such as polyethylene terephthalate (PET), wherein the polyester film is provided with an additional surface treatment in the form of a metallization or another inorganic layer, for example SiOx or AlOx or else an adhesion-promoting layer ( Primer) may be provided for applying a sealing layer. Furthermore, the barrier film may consist of polyamides, for example PA 6 or PA 12, or other materials of this group. Polyolefins, for example made of polyethylene (PE), may also be used as the barrier film, different types of PE (PE-LD, PE-HD, etc.) being used here, for example with Ziegler-Natta catalysts or with metallocene catalysts can be prepared, ethylene copolymers (EVA, EMA, etc.) or mixtures of these, polypropylene (PP) and PP copolymers or other thermoplastic polyolefins can be used. As a barrier film also films of biopolymers based on renewable raw materials, such as starch polymers, from polylactic acid (PLA), from lignin-based polymers, from polyhydroxyalkanoates (PHAs), etc., from corresponding mixtures or compounds, from biodegradable / compostable raw materials, eg special bio-polyesters (for example Ecoflex), etc., are used. The barrier film may be a monofilm which may be unstretched (for example cast-PP) or oriented (for example OPA, OPP). The barrier film can also be a coextruded multilayer film, for example a polyethylene film with an additional barrier layer made of EVOH or a film with specially designed sealing or peeling layers.

It is also possible to use other materials known to the person skilled in the art as a barrier film, wherein the respective selection can be made on the basis of the desired material properties. For example, foils of metal, e.g. Aluminum foils, paper or fabric materials are used as barrier film or contained in this.

The barrier layer may be constructed of a single material, or it may consist of several layers of different materials. Multilayer barrier layers may, for example, be extrusion-coated films, or the barrier layer may be a multi-coextruded film to combine advantageous properties of different extrudable materials and / or to influence the surface properties of the film through the particular outer layer selected.

Examples of multilayer and optionally coextruded films include films of a major material provided with one or more coatings on one or both surfaces. Between the main material and the coating, a primer layer, adhesive layer or adhesive layer may be provided. The main material may for example be selected from the materials exemplified above for the barrier films, or it may also consist of multiple layers of these materials, each with or without interlayers (e.g., adhesive, primer or subbing layer). The coating can again consist of several layers. For example, a coextrusion coating of different coating materials can be applied to a layer of a main material. The main material can be provided with the same or with different coatings either on one side or on both sides.

As a coating material, for example, a sealing or peel film or a heat sealing lacquer (HSL), either directly adhesive or with a primer or adhesive layer are applied to the main material. The coating material and / or the main material may further be treated with a sunscreen, e.g. a metallization, be provided.

The laminating adhesive may be selected from wet laminating or dispersion adhesives, such as LANDOCOLL 7170 from Svenska Lim; Dry-wall adhesives such as ADCO-TE ™ 545 or CATALYST F from Rohm and Haas or Liofol UK 3646 or UK 6800 the company Henkel; from solvent-free adhesive systems, from cold seal adhesives, such as Crodaseal 22-121 from Croda Adhesives, or from an extrusion-coated lamination. For lamination, extrusion lamination processes can also be used. An example of a favorable composite material for the production of blanks is a composite paper / dry-laminating adhesive / polyester, where polyester acts as a barrier layer. Polyester has the advantage of a high puncture resistance and is therefore particularly suitable as a barrier layer for printed circuit boards. The high puncture resistance allows secure stacking of multiple containers sealed to the board, with the board being loaded by the weight of the containers stacked above it, as may be the case with yogurt cups, for example. In particular, during transport by the customer, for example in a shopping cart or a shopping bag, the boards can be damaged by mitgetrportierte, Schafkantige or sharp objects. Good puncture resistance prevents this. Since polyester is not readily sealable, the polyester layer may have a sealant film on the side facing away from the paper. As a result, it is not necessary, after the lamination, to apply an additional sealing layer to the barrier layer (provided with the stress compensation zones). Polyester layer and sealing layer may be prepared as coextruded film as set forth above. The paper may preferably be printed on the coated side, ie on the smooth, high-quality side, wherein the barrier layer may be applied to the opposite, rough layer.

Another advantageous combination of materials is paper / solvent-free laminating adhesive / PLA. This composite foil is highly biodegradable. By using environmentally friendly inks such as watercolors for printing, almost completely rotting boards can be made.

The subject invention further relates to the use of a composite film according to the invention for producing a circuit board for firing containers. Furthermore, the invention relates to the board produced from the composite film. Such boards are thinner and lighter than conventional symmetrical layer profile boards, and they can be manufactured so that no bowing effects occur even under changing environmental conditions. This ensures a safe and reliable separation. As indicated above, the boards may be biodegradable if desired. The containers may preferably be sealed so that the barrier layer of the boards face the container contents. In other cases, however, the container may also be sealed to the carrier layer, in which case the side of the barrier layer would form the outer surface. In a preferred embodiment, the board can have a sealing area for sealing with the container on the side of the barrier layer and / or on the side of the carrier layer. Depending on the application, the side of the barrier layer and the expansion regions present therein can thus be provided for the side facing the packaging (and the packaged product) or for the "attractive side" facing the customer.

In a further aspect, the invention relates to a device of the type mentioned, in which according to the invention, between the barrier film feed and the pressing device, an expansion member for introducing a Dehnmusters from stretched stretched areas is provided in the barrier film. The extensor can be easily integrated into known devices for producing composite films.

In an advantageous embodiment, the expansion member may be formed by the intermeshing profiles of a positive profile roller and a negative profile roller, between which the barrier film is guided. With this device, the Dehnbereiche can bring in a simple manner and with a variety of selectable pattern in the barrier film. Preferably, the penetration depth of the profiles, ie the distance between positive profile roller and negative profile roller can be adjusted. The penetration depth is an important process parameter in order to adapt the manufacturing process to different material properties. When using the device according to the invention, especially at the edge regions of the profiled rollers, material can be "pulled in" from the edge of the barrier film which is guided between the positive profile roller and the negative profile roller However, barrier film is rather minor and can easily be taken into account as an operating parameter A further advantageous embodiment can provide that the pressing device is designed as a pressure roller pressing against the negative profile roller, between which the material to be pressed into the composite film is guided compact dimensions, since the negative profile roller is used on the one hand as part of the expansion element and on the other side as part of the pressing device, thereby ensuring that the lamination takes place immediately after the introduction of the expansion areas On the one hand, it can be ensured that the width of the barrier film resting on the negative profile roller with the expansion areas introduced therein does not change between the step of stretching in the expansion element and the lamination in the pressing device. This ensures that the expansion areas during lamination have the excess material required to form the stress compensation zones. The profiles of the negative profile roller serve as recesses in which the Dehnbereiche received while the barrier film is laminated to the substrate at the other locations. The barrier film is thus not pressed against the carrier material in the regions of the negative profiles, but can form the raised pattern in this region.

The shape of the profiles introduced into the profiling roll, the material being processed and the pressure settings of the pressing means and the stretching means determine how the stretching areas "fold" after lamination to form bumps, spacers and / or stress relief zones By suitable selection of the parameters, however, it is usually possible to achieve a desired folding shape even without such an additional device, since the stretching regions have a larger areal extent , as the surface areas of the carrier material lying opposite to them, can form surfaces which are not connected to the carrier material and which can at least partly lie against one another in the side of the barrier layer facing the carrier material nn in the Dehnbereich forms a fold.

In experiments with different embodiments of the device according to the invention, the inventors have surprisingly found that sometimes the raised pattern is not formed at the points of the strain pattern, but also in adjacent surface areas in which no Dehnbereiche were actually introduced into the barrier film. Depending on the material combinations, processing speeds and extent of elongation, different raised patterns are formed, which can be optimized by the skilled person by routine work and experiments. In particular, the type of pattern that forms in this case can be regulated by means of the delivery of the roller pair of positive and negative profile rollers. For this purpose, a particularly advantageous embodiment of the roller pair has been developed in which the positive profile roller has a regular or irregular arrangement of raised embossing pin, and the negative profile roller has corresponding recesses into which engage the embossing pin. With this embodiment, it was possible to produce a particularly uniform mesh pattern, the connecting lines of the generated mesh pattern each extending between the stretching regions which were introduced into the barrier foil by the embossing pins.

In a further aspect, the invention relates to a method for producing a composite film having at least one carrier layer of a carrier material, at least one barrier layer of a barrier film and at least one intermediate laminating adhesive layer. In this case, before stretching a stretch pattern of stretched stretching in introduced the barrier film, and then the barrier film laminated as a barrier layer on the carrier layer. A deformation of the barrier film brought about by the stretching or a partially elastic recovery after stretching produces a raised pattern on the composite foil, wherein the barrier layer in the area of the raised pattern on the side facing the carrier layer has surfaces which do not overlap with the one after lamination Carrier layer are connected. Depending on the embodiment, the resulting raised pattern may act as a spacer, haptic / optical pattern, and / or stress relief zone.

In an advantageous embodiment, the barrier film for introducing the Dehnbe- rich between a positive profile roller and a negative profile roller with intermeshing profiles are performed.

Advantageously, the composite of carrier layer, laminating adhesive layer and barrier layer between the negative profile roller and a pressure roller can be pressed.

In an advantageous embodiment, the lamination between the negative profile roller and a pressure roller can be carried out, wherein the time interval between embossing and lamination is determined by the radial position of the contact point between the pressure roller and negative profile roller and the peripheral speed of these rollers.

Depending on the choice of materials and parameters, the raised pattern may be different from the stretch pattern. The raised pattern can be formed both in the region of the expansion regions and outside these regions, for example at connecting lines between two closely spaced expansion regions. This can create a visually pleasing pattern with a regular look. The composite film produced thereby can be wound on rolls without the pattern would form from layer to layer further building up elevations. Advantageously, the formation of the raised pattern can be regulated by way of delivery of the roller pair and / or the time interval between embossing and laminating. The optimum parameters for the respective material combinations and production processes can be found out by a person skilled in the art on the basis of routine tests. Advantageously, the lamination can take place while the barrier film partially elastically reforms after the introduction of the expansion pattern. As a result, the barrier film assumes its final shape only after lamination onto the carrier layer and can still shift slightly, distort or shift on the carrier layer to form the raised pattern. The subject invention will be explained in more detail below with reference to Figures 1 to 13, which show by way of example, schematically and not by way of limitation advantageous embodiments of the invention. It shows

1 a and 1 b are each a sectional view through a composite film according to the invention with the voltage compensation zone provided therein;

Fig. 2 is a sectional view through a composite film according to the invention provided with a coating layer;

FIG. 3 shows a circuit board in a plan view from the side of the barrier layer; FIG.

4 shows a schematic representation of a device according to the invention for producing the composite film;

5 shows a sectional view of the profiled rollers along their contact line along the section line V-V in FIG. 4;

6 is a sectional view of the negative profile roller and the pressure roller along its contact line according to the section line Vl-Vl in Fig. 4. FIGS. 7a to 7h show exemplary arrangements and patterns of voltage compensation zones;

8 to 1 1 exemplary embodiments of negative and positive profile rollers; and

12 and 13 show alternative embodiments of the device according to the invention for producing the composite film, Figs. 14 to 17 show different circuit boards made of a composite film according to the invention, which were produced with the same roller pair.

1 a and 1 b each show a sectional view through the layers of an exemplary composite film 20 according to the invention, wherein the size and width ratios are not shown to scale. The composite film 20 shown in FIG. 1 a has a carrier layer 1, on the surface of which a barrier layer 2 is applied by means of a laminating adhesive layer 3. On the outer surface of the barrier layer 2 may optionally be provided a sealing film 21, which is shown as a dashed line. In the barrier layer 2, a stress compensation zone 4 is provided, which is formed as a fold 5 of the barrier layer 2. Below the fold 5 is in the position shown a cavity in which the carrier layer 1 facing surface of the barrier layer 2 is not connected to the carrier layer 1. In the case of the composite film 20 shown in FIG. 1, a relatively high elongation has been introduced into the barrier layer 2 in the region of the stress compensation zone, so that the barrier film 2 has folded to one side in the expansion region 6 forming the stress compensation zone 4 and has formed a fold 5. The method of introducing the stretch and the lamination is described in detail below. The cavity below the expansion region 6 can be further compressed during rolling up of the composite film 20 or in a downstream roll arrangement, wherein a certain elevation h always remains in the region of the stress compensation zone 4 due to the material excess. When the material of the barrier layer 2 in the area of the stress compensation zone 4 is pressed against the carrier layer from the outside, for example when the material is rolled up, and thereby comes into contact with the laminating adhesive layer 3, a fold generally remains in the fold 5 in which the the carrier layer 1 facing surface of the barrier layer 2 in the interior of the fold 5 abuts each other and thus is not connected to the carrier layer 1. If the carrier layer 1 now expands or contracts, for example because of the effects of weathering, moisture or heat, the fold 5 can compensate for this change and prevent a tension occurring in the barrier layer 2 or the carrier layer 1 which leads to a curvature of the composite film 20 would lead. Such bulges lead to a concealment of blanks which are punched out of the material. The stress compensation zone 4 thus prevents voltage differences between the barrier layer 2 and the carrier layer 1 in a simple manner. Such stresses can occur, in particular, when the material properties of the layers are very different, as is the case, for example, with paper / plastic, metal / plastic or metal / paper composite films. The indicated in Fig. 1 a seal film 21 serves to seal the stamped out of the composite film 20 board with the container, which closes, sealingly. The sealing film 21 may have been applied to or co-extruded onto the barrier film 9 forming the barrier layer 2 and may thus be considered as an integral part of the barrier layer 2, the sealing film 21 following the course of the barrier layer 3 in the region of the stress compensation zone 4 , To seal the edge of the board is pressed in a known manner with a sealing tool with application of a sealing pressure and a sealing temperature against the edge of the package to be sealed. Usual sealing pressures are in the range of about 2-4 bar, generally about 3 bar. The sealing temperature can be, for example, between 120 C ° and 290 C °, usually between 180 ° C and 250 ° C with conventional seal films. In the region of the stress compensation zones 4, where the fold 5 causes a changed thickness of the composite film 20, the sealing is ensured by an elastic deformation of the layers, in particular the barrier layer 2. tet. Below the fold 5, the outer surfaces of the sealing film 21 abut each other, which ensures the tightness of the seal in this area. When sealing, any cavities and cannulas that remain between the barrier layer 2 and the carrier layer 1 are completed and tightly sealed in the sealing area. Since the sealing area is generally provided around the entire circumference of the board, the cannulas are hermetically sealed from all sides. The needles remaining inside the surface of the board are thus also laterally sealed and have no connection to the environment through which impurities or microbes could penetrate. Fig. 1b shows a composite foil 20, which corresponds in some respects to the composite foil shown in Fig. 1a, but in which, prior to lamination, a less pronounced stretch region 6 was introduced into the barrier foil. Due to the rather low material excess of the expansion region 6, no fold 5 has formed in the stress compensation zone 4, so that the stress compensation zone 4 is formed as the region of a pure lift off of the barrier layer 2 from the carrier layer 1 (or the laminating adhesive layer 3). Here too, the stress compensation zone 4, based on the total thickness d of the materials of the composite film, has an elevation h. This elevation h is generally not constant over the course of the stress compensation zone 4, since the expansion region 6 may be pressed against the laminating adhesive layer at another point or form a fold 5. Nevertheless, due to the material surplus in the entire stress compensation zone 4, there is always a certain elevation h. Here, too, the surplus of material in the expansion areas allows effective compensation of differences in tension to prevent tipping.

The composite film shown in Fig. 1 b has no sealing film 21, but such may also be readily provided here.

FIG. 2 shows a cross-sectional view of an alternative embodiment of the composite film 20 according to the invention, in which a barrier film without a sealing film 21 has been used as the barrier layer 2. In order to nevertheless enable a sealing of the board, the composite film 20 is therefore provided with an additional coating layer 7, for example of a heat sealing lacquer, which is required for specific applications. For the sake of representability, the thickness of the coating layer 7 in FIG. 2 is shown exaggeratedly wide. In practice, the coating layer 7 is generally much thinner; for example, the coating layer 7 may also be thinner than the thickness of the barrier layer 2.

Although the representation in FIG. 2 would suggest that the continuous coating layer 7 would destroy the effect of the stress compensation zones 4, The inventors surprisingly found that the stress compensation zones 4 are nevertheless effective, and in this embodiment as well, it is possible to produce perfectly flat boards which have little or no intermeshing effects.

FIG. 3 shows a plan view of the barrier layer of a printed circuit board 1 1 punched out of a composite film 20 according to the invention, wherein several voltage equalization zones 4 running parallel are arranged distributed over the width of the board. The voltage compensation zones 4 are aligned parallel to the direction in which the board 1 would buckle 1 without the stress compensation zones. As a result, the circuit board 1 1 always remains even in different weather conditions, since the stress compensation zones 4, the occurrence of stresses that lead to a curvature prevent. In an exemplary embodiment, the distances between the stress compensation zones 4 and the width of the stress compensation zones 4 can be selected depending on the material properties of the composite film and their layer thicknesses. For example, the stress compensation zones 4 of FIG. 3 may be spaced apart by about 4 to 10 mm, for example about 6 mm, and have a width of about 0.5 to 2 mm, for example about 1 mm.

4 shows an exemplary embodiment of a device according to the invention for producing the composite film 20 described above. The carrier material 8, from which the carrier layer 1 of the composite film is to be made, is supplied via a carrier material feed 12, the carrier material feed being illustrated schematically as an arrow in FIG is. The carrier material 8 can be unrolled from a roll, or fed directly after printing, so that the device can be provided as an inline element of the printing device. The carrier material 8 is coated in a laminating adhesive application 13 on one side with laminating adhesive 10, the laminating adhesive layer being leveled with a blade 24. The coated with the laminating adhesive 10 carrier material 8 is then passed over a drying roller 25 and dried, wherein the evaporating solvent are sucked through a vent 23. The drying roller 25 can be heated itself, alternatively or additionally, a heating element 22 or other heating elements can be provided to accelerate the setting of the laminating adhesive 10. Drying and setting of the laminating adhesive 10 is necessary, in particular, for dry laminating adhesives, but pre-treatment of the laminating adhesive 10 applied to the carrier material 8 prior to lamination may also be desired or required for other laminating adhesive types.

The carrier material 8 coated with the laminating adhesive 10 is then combined with a barrier film 9 and pressed together in a pressing device 15 and joined together. the press, wherein the pressing means 15 is part of a special roller assembly consisting of a positive profile roller 17, a negative profile roller 18 and a pressure roller 19, and which will be described in more detail below.

The barrier film 9 is fed from a barrier film feed 14 to the roll assembly and is conveyed from the negative profile roll 18 to the press device 15 formed by the nip roll 19 pressing against the female profile roll 18. The barrier film 9 is preferably supplied at room temperature, wherein it may optionally also be heated or cooled in order to influence the expansion and deformation properties. Cooling may be provided, in particular, when the barrier film 9 is fed immediately after the (co) extruding of the apparatus shown in FIG. 4. Before the barrier film 9 reaches the pressing device 15, it also passes through an expansion element 16, which is formed by the mutually meshing profiles of the negative profile roller 18 and the positive profile roller 17. The meshing profiles of the two profile rollers 17, 18 are shown in the sectional view of FIG. 5. The negative profile roller 18 has a series of circumferential grooves 26, and the positive profile roller 17 has corresponding circumferential projections 27, which engage in the grooves 26, respectively. Between the profiles of the negative profile roller 18 and the positive profile roller 17 there is a sufficient distance everywhere, so that in the region of the Dehnorgans 16 between the profiles of the profile rollers 17, 18 clamped barrier film 9 in the region of each groove of the negative profile roller 18 of the corresponding projection 27 of the positive profile roller 17 indeed pressed into the groove and stretched, but not damaged or cut. Thus, in each groove 26 forms a longitudinally extending to the supplied barrier film 9 Dehnbereich 6 from. In the region between the grooves 26, where the barrier film 9 rests against the outer periphery of the negative profile roller 18, the material of the barrier film 9 is not stretched, but only transported by the negative profile roller 18 on.

The partially stretched barrier film 9 is transported by the negative profile roller 18 by half a turn and then passes into the pressing device 15, which is formed by the pressing against the negative profile roller 18 pressing roller 19. In the pressing device 15, the carrier material 8 coated with the laminating adhesive 10 and the barrier film 9 conveyed by the negative profile roller 18 are pressed against one another and the barrier film 9 is laminated onto the carrier material 8.

6 shows a sectional view through the pressing device 15, that is to say the contact area between the negative profile roller 18 and the pressure roller 19. As can be seen in the sectional view of FIG. 6, the expansion regions 6 of the barrier film 9 are also located in the region of the pressing foil. Device 15 protected in the grooves 26 of the negative profile roller 18, so that the barrier film 9 is not pressed in the Dehnbereichen 6 to the substrate 8.

After lamination in the pressing device 15, the material of the barrier film 9 projecting from the carrier material in the stretching regions 6 abuts against the carrier material 8, taking up the folded form shown in FIGS. 1 and 2. After lamination, the composite film 20 is forwarded for further processing or rolled up on a roll.

Cavities may remain under the expansion areas, so that cannulas extending along the stress compensation zones may form. These cannulas pose no problem when used as a circuit board because they are compressed and thereby sealed at the edge area of the board during sealing, applying a sealing pressure and a sealing temperature. Therefore, it is generally not necessary to "flatten" or press the cavities remaining under the stretching regions by means of their own devices, even if this could be carried out easily if necessary.The formation of the stress equalization zones from the expansion regions and the type of folding can be particularly about the relative position between the negative profile roller 18 and positive profile roller 17, which controls the extent of the elongation, influence and control the formation of the profiles of these profile rollers 17, 18 and the contact pressure of the pressing device.

FIGS. 4 to 6 show a negative profile roller 18 with grooves 26 extending in the direction of rotation along the circumference of the roller and corresponding protrusions extending in the direction of rotation around the circumference of the positive profile roller 17, which engage in the grooves 26 of the negative profile roller 18. This leads to stress compensation zones 4, which extend longitudinally to the transport direction of the composite film. Alternatively, the expansion regions 6, or the stress compensation zones 4 formed thereby, but also numerous other patterns can be formed by changing the coordinated profile of the profile rollers 18, 19.

FIGS. 7a to 7h show a number of alternative patterns that can be achieved with the expansion regions, wherein an arrow indicates the direction of advance of the composite film in the manufacturing process. The patterns are purely exemplary, schematic and not to scale. The distances between the stress compensation zones 4 can be selected by the person skilled in the art, if appropriate by carrying out test series, in accordance with the respective specifications. FIG. 7 a shows the pattern of the stress compensation zones 4 running longitudinally to the feed direction, as can be introduced in a composite film 20 with the aid of the device shown in FIGS. 4 to 6.

FIG. 7b shows stress compensation zones 4 extending at an angle to the feed direction. FIG. 7c shows stress compensation zones 4 extending transversely to the feed direction. The stress compensation zones 4 are not continuous, but have interruptions. Optionally, the interruptions may also be arranged offset to one another, or the stress compensation zones 4 could also extend across the entire composite film. Fig. 7d shows stress relief zones 4 extending in a wavy pattern over the entire composite film. This pattern could also be longitudinal or oblique or interrupted.

FIGS. 7e and 7h each show a pattern with cross-over stress compensation zones 4, which are arranged in the form of a check pattern. The pattern of Fig. 7h is aligned parallel to the feed direction of the composite film, whereas the pattern of Fig. 7e is oblique thereto.

Fig. 7f shows a pattern in which the stress compensation zones 4 have been reduced to spot size. The dots (or circular areas) may be arranged regularly or irregularly and may optionally be combined with longitudinal stress compensation zones 4 if the dot pattern does not sufficiently reduce the bowing effects. With the punctiform stress compensation zones 4, for example, the separation behavior of the boards can be improved, or it may be the Gleitbzw. Friction properties of the composite film can be influenced. Instead of points or circular surfaces, other decorative shapes, such as rectangles, diamonds, rings or stars, can be introduced.

Similarly, patterns composed of geometric polygons could be incorporated into the barrier film, such as a hexagon pattern, such as a honeycomb structure, an octagon pattern, or other pattern composed of polygons. Finally, FIG. 7g shows a pattern of stress compensation zones 4 in which diamond-shaped and point-shaped stress compensation zones 4 are combined. The patterns shown in FIGS. 7a to 7h are purely illustrative and not drawn to scale and can be changed or combined as desired, with no limit to the design possibilities. Even if only regular patterns are shown in FIGS. 7a to 7h, the patterns can also be made irregular.

In the manufacturing method set forth above, the pattern inevitably repeats with each revolution of the profile rolls. However, on a printed circuit board produced from and stamped from the composite film, which only comprises a partial area of the overall pattern, the pattern may appear completely irregular. FIGS. 8 to 11 show pairs of rollers each comprising a negative profile roller 18 and a positive profile roller 19, which can be used to produce stretching regions with different patterns.

The profile rollers may preferably each be made of metal, wherein the surface can be hardened to increase the service life or be provided with a life-enhancing surface coating. For example, the profile rollers may be at least partially provided with a ceramic coating. In another embodiment, plastic rollers can be used as profile rollers. Relatively cheap plastic rollers are particularly advantageous for the production of small batches, or in cases where no great stress on the profile rollers is to be expected. Alternatively, it is also possible for a roller, for example only the positive profile roller, to be made of metal, and the other roller may be made of plastic and optionally designed as a wearing part.

8 shows a roller pair of a negative profile roller 18a with grooves 26a extending transversely to the feed direction (and parallel to the axis of the roller) and a positive profile roller 19a with corresponding, continuous projections 27a extending parallel to the axis of the positive profile roller 19a. With the aid of this roller, it is also possible to provide poorly stretchable materials with expansion regions by drawing more film material into the groove 26a in the area of the projections 27a than corresponds to the speed of the roll surface. With this roller, it would also be possible to introduce tension compensation zones into hardly or not at all extensible material, such as paper, in which case an expansion region would not represent an actual elongation, but a region of an essentially unstretched excess material. In connection with the subject description, such essentially unstretched material surpluses are also referred to as expansion regions in an analogous manner. 9 shows a roller pair of a negative profile roller 18b and a positive profile roller 17b, wherein the profile has grooves 26b or projections 27b running obliquely to the direction of rotation, and wherein both sides of the profile rollers have a different inclination. The grooves 26b and projections 27b abut each other in the middle of the rollers at an angle.

10 shows a roller pair in which the negative profile roller 18c substantially corresponds to the negative profile roller 18a of FIG. 8, but the positive profile roller 17c has interrupted projections 27c. This configuration forms a pattern substantially similar to that shown in Fig. 7c. Finally, FIG. 11 shows a roller pair of a negative profile roller 18d and a positive profile roller 17d with which a dot or circular surface pattern can be introduced into the composite film, which substantially corresponds to the pattern of FIG. 7f. The negative profile roller 18d has no grooves, but circular recesses 26d, in which engage the knob-shaped protrusions or embossing pin 27d of the positive profile roller 17d. The diameter of the circular recesses 26d is greater than the diameter of the embossing pins 27d, so that although the film clamped between the pair of rollers is stretched into the recesses 26d, sufficient space remains at the edge of the recess so that the barrier film is not sheared off. The embossing pin may for example be cylindrical, wherein the end face may be outwardly cambered. Optionally, the embossing pins can also be designed hemispherical or as a semi-ellipsoid.

In a further, not shown embodiment, instead of the pair of rollers, a vacuum roller may be used, which may for example have the shape of the negative profile roller 18d of Fig. 1 1, wherein the individual recesses 26d can be subjected to a vacuum, so that the barrier film for introducing the stretched Sucked portions of the vacuum in the recesses 26d and is stretched into the recesses 26d inside. A positive profile roller is not required.

Further roll forms could be, for example, a pair of rolls with a combination of a negative profile roll with longitudinal grooves and recesses arranged between the grooves, for example circular depressions with a correspondingly formed positive profiled roll.

In a further embodiment, it would also be possible to provide the roller pair with a "mixed profile", wherein each roller has both positive profile parts, as well as negative profile parts, for example a roller with grooves and pins and a korres- ponding roller with engaging in the grooves projections and the pin receiving recesses.

All cited examples of roll combinations and stretch patterns are illustrative and not limiting. The person skilled in the art is able, with the aid of the teachings of this publication, to carry out any stretching pattern without having to be inventive.

FIGS. 12 and 13 show alternative embodiments of the device according to the invention for producing the composite foil 20. Similar or equivalent elements are provided with the same reference numerals in FIGS. 4, 5, 6, 12 and 13. Fig. 12 shows an apparatus for producing a composite film 20 using a drying channel 28 having a plurality of drying zones Ti, T ₂ , ..., T _n for drying the composite material. Here, the wetted with the laminating adhesive 10 carrier material 12 is laminated directly after passing through the laminating adhesive application 13 in the pressing device 15 between the negative profile roller 18 and the pressure roller 19 with the barrier film 9, in the previously by the Dehnorgan 16 between the negative profile roller 18 and the positive profile roller 17 were introduced in an analogous manner as described above Dehnbereiche.

The laminated composite film 20 is then dried in the drying channel 28, wherein the drying zones Ti, T ₂ ,..., T _{n have} different heating stages in order to ensure a ramp-like heating and cooling of the composite film in the drying channel 28. This arrangement is particularly suitable for the use of wet laminating adhesives which need not be dried between application and lamination. The solvents of the laminating adhesive 10 evaporate through the carrier layer 1 in the drying channel 28. The use of wet laminating adhesives is particularly suitable, for example, for composite films with a carrier layer made of paper and an aluminum barrier layer. The solvent evaporates through the paper layer.

13 shows another exemplary embodiment of the apparatus for producing a composite film 20 that uses a drying channel 28 with a plurality of drying zones Ti, T ₂ ,..., T _n , but the drying channel is between the laminating adhesive application 13 and the pressing device 15 arranged. The drying channel 28 thus essentially corresponds in its function to the heating element 22 or the drying roller 25 of FIG. 4 and serves for evaporating the solvents of a dry-laminating adhesive which is used as a laminating adhesive 10. To improve the laminating process, a cooling roller 29 is provided instead of the pressure roller 19 of FIG. 4 in the roller arrangement of FIG. The coated with the laminating adhesive 10 carrier material 8 is guided around a portion of the circumference of the cooling roller 29 and thereby cooled after passing through the drying channel. The cooling roller 29 has a sufficiently large diameter in order to cool the carrier material 8 coated with the laminating adhesive 10 to an optimum temperature for the lamination. Further, the extent of cooling may be adjusted by changing the angle a at which the negative profile roller 18 is located relative to the location where the substrate contacts the chill roller 29. Figures 14 to 17 show blanks made in multiple series of tests using the same apparatus, with only the infeed of the pair of rolls varied. As a positive profile roller, a roller with regularly arranged Prägezapfen was used and as a negative profile roller, a roller with corresponding circular recesses was used, in which engage the embossing pin of the positive profile roller. This essentially corresponds to a pair of rollers, as shown by way of example in FIG. 11. The stretch pattern 30 introduced by the pair of rolls into the barrier film corresponded to a regular arrangement of deep-drawn circular areas with a diameter of about 4 mm, the lateral spacing between the circles likewise being about 4 mm in each case. Polyester films with a thickness of between 8 and 10 μm were used as the barrier film in a number of test series, which were laminated to a support material made of paper with a thickness of about 60 μm. The laminating adhesives used were conventional laminating adhesive systems, preferably dry-cell laminating adhesive systems.

FIGS. 14-17 each show a circuit board 11 made of a composite film according to the invention, which was produced as described above. FIG. 14 shows the result of a first test turn in which the infeed of the pair of rolls was chosen so that the embossing pins penetrated only slightly into the circular depressions, and accordingly only a weakly pronounced elongation pattern 30 (some circles of the elongation pattern are in the lower right corner) the board 1 1 exemplified highlighted) was intended. Developers had expected that the raised pattern 31 formed during lamination would substantially correspond to the stretch pattern 30. Surprisingly, however, the raised pattern 31 formed not only in the region of the elongated pattern 30 (ie at the edge of the indentations), but also within the circles of the elongated pattern 30 and also between the circles, with the raised pattern substantially in formed diagonally to the feed direction of the barrier film (arrow) running lines. This unexpected result was further investigated by the developers, whereby the delivery of the roller pair was gradually increased in further test series. Fig. 15 shows a board 1 1 with a raised pattern 31, which has resulted in a slightly increased delivery (ie increased elongation). It can be seen that the stretch pattern 30 in the raised pattern 31 is only weaker, but still recognizable. The regions of the raised pattern 31 lying outside and inside the circles of the elongated pattern 30 again form diagonal lines, but the pattern is more irregular, more "frayed" and wider than in the example of FIG. 14.

With an even stronger roller delivery or elongation, the raised pattern 31 changed again in a surprising manner: FIG. 16 shows that now a net-like, raised pattern 31 has formed between the individual (still easily recognizable) circles of the elongation pattern 30, the mesh pattern extending substantially evenly across the surface of the composite foil. Such a net-like pattern offers particular advantages, since a composite foil formed in this way can easily be rolled up on rolls without there being any build-up of elevations. The printed circuit boards provided with this pattern have a visually appealing surface structure, the raised pattern reliably prevents the board from being bruised, and the raised pattern prevents the occurrence of a glass pane effect when singulated.

Increased infeed (Figure 17) resulted in a raised pattern 31 where the stretch pattern 30 was only less noticeable, with the raised pattern 31 again forming a net-like structure, but less uniform and coarser than in the previous experimental result shown in FIG. 16.

Although the precise processes involved in the formation of the respective raised pattern have not yet been fully investigated, the inventors have gained the knowledge that the device according to the invention can be used to produce composite films whose raised pattern is independent of the shape of the In the barrier film introduced Dehnmusters differs more or less strongly, with only a change in the delivery of the pair of rollers can change the shape of the pattern very strong.

Without this theory being intended to limit the invention in any way, it is believed that also the partial elastic recovery, which begins after the introduction of the strain, plays a role in the formation of the raised pattern. Thus, the emergence of the raised pattern can be influenced not only by the delivery of the pair of rollers, but also by the peripheral speed, the time between the introduction of the expansion pattern (eg by the expansion member 16 in Fig. 4) and the laminating (eg by the pressing device 15 in Fig. 4) passes, is changed. This can cause the shape of the barrier film (and thus the raised pattern) to change even after laminating.

However, the time between insertion of the stretch pattern and laminating can also be easily influenced by a change in the arrangement of the rolls (eg positive profile roll 17, negative profile roll 18 and nip roll 19 in Fig. 4), such as by arranging the rolls in an angular configuration, so that the distance between Dehnorgan 16 and pressing device 15, or the peripheral region of the negative profile roller 18 along which the barrier film 9 is transported with the introduced Dehnbereichen 6, is increased or decreased. By adjusting these and other parameters (e.g., temperature, cooling, shape of the strain pattern, etc.), those skilled in the art will be able to determine, by routine work and experiment, the settings for each combination of materials that will yield an optimal raised pattern.

In addition to the stretching patterns and roll shapes shown by way of example in FIGS. 7 to 11, combinations of stamping pins and depressions with other shapes, for example diamond-shaped, star-shaped, in the form of a polygon, oval or the like could be used, for example. Rolls with rounded negative and / or positive profiles can also be used, for example if the stretch pattern 30 in the raised pattern 31 is not or only slightly recognizable. Combinations of negative and positive profiles are also contemplated in which the negative and positive profiles are more different, for example, circular stubs could engage in groove-like recesses, or rectangular, polygonal or oval stubs could engage in circular recesses. It is intended that such and similar combinations of roller pairs or the corresponding methods and manufactured products fall within the scope of the claims. The invention is not limited to the embodiments set forth above and can be put into practice in many alternative ways. For example, prior to laminating, the laminating adhesive could not be applied to the carrier material, but directly onto the barrier layer or coextruded therewith. Reference numerals:

Carrier layer (1)

Barrier layer (2)

Laminating adhesive layer (3) Stress compensation zones (4) Folding (5)

Stretching areas (6)

Coating layer (7)

Carrier material (8)

Barrier film (9)

Laminating adhesive (10)

PCB (1 1)

Carrier material feed (12) Laminate adhesive application (13) Barrier film feed (14) Pressing device (15)

Dehnorgan (16)

Positive profile roller (17)

Negative profile roller (18)

Pressure roller (19)

Composite foil 20

Sealing film 21

Heating element 22

Ventilation 23

Doctor 24

Drying roller 25

Groove 26

Lead 27

Drying channel 28

Cooling roller 29

Stretch pattern (30)

sublime pattern (31)

Claims

claims

1 . Composite film (20) with at least one carrier layer (1) comprising a carrier material (8), at least one barrier layer (2) comprising a barrier film (9) and at least one intermediate laminating adhesive layer (3), characterized in that the composite film (20) on the carrier layer (1) facing away from the barrier layer (2) has a raised pattern (31), wherein the barrier layer (2) in the region of the raised pattern (31) with respect to the unstretched barrier film (9) stretched stretching regions (6) , and wherein the barrier layer (2) in the region of the raised pattern (31) on the side facing the carrier layer (1) has surfaces which are not connected to the carrier layer (1).

2. The composite film (20) according to claim 1, characterized in that the not with the carrier layer (1) connected surfaces of the carrier layer (1) facing side of the barrier layer (2) abut each other at least partially.

3. The composite film (20) according to claim 1 or 2, characterized in that the raised pattern (31) corresponds to a Dehnmuster (30) at Dehnbereichen (6).

Composite film (20) according to claim 3, characterized in that the raised pattern (31) forms tension compensation zones (4) which compensate for stress-induced stresses between the layers.

5. The composite film (20) according to claim 4, characterized in that the stress equalization zones (4) as along the composite film extending folds (5) or lifts the barrier film (9) are formed, which extend along the Dehnmusters (30).

6. The composite film (20) according to any one of claims 3 to 5, characterized in that the Dehnmuster (30) is a regular or an irregular pattern.

7. Composite foil according to one of claims 3 to 6, characterized in that the raised pattern (31) from the Dehnmuster (30) at least partially different.

A composite foil according to claim 7, characterized in that the raised pattern (31) is a net-like pattern.

Composite film (20) according to one of claims 1 to 8, characterized in that the raised pattern (31) has an elevation (h) on the surface of the composite film (20), the ratio (h / d) of the elevation ( h) to the summed thickness (d) of the individual material layers in the composite film is less than 10 and preferably less than 5, and in particular has a value of about 0.05 to 2, for example about 0.1 to 2.

10. The composite film (20) according to any one of claims 1 to 9, characterized in that the carrier layer (1) over its entire surface with the Kaschierkleberschicht (3) is coated.

1 1. Composite foil (20) according to one of claims 1 to 10, characterized in that the composite foil (1) has a coating layer (7).

12. The composite film (20) according to any one of claims 1 to 1 1, characterized in that the carrier layer (1) is printed on the barrier layer (2) facing away from and / or facing side.

13. Composite foil (20) according to one of claims 1 to 12, characterized in that

- The support material (8) is selected from a fiber material, such as paper or cardboard, in particular paper or recycled paper having a thickness between 20 and 120 μηη, preferably between 40 and 60 μηη; a metal foil, preferably an aluminum foil, in particular with a thickness between 5 μm and 30 μm, preferably between 8 μm and 20 μm; or a plastic material, such as polyester or another plastic, in particular with a thickness of 5 to 50 μηη, preferably between 12 and 30 μηη and particularly preferably of about 23 μηη;

- The material of the barrier film (9) is selected from polyesters, such as polyethylene terephthalate (PET), wherein the polyester film with an additional surface treatment in the form of a metallization or other inorganic layer, for example of SiOx or AlOx or an adhesion-promoting layer (Primer) may be provided for applying a sealant layer; Polyamides, such as PA 6 or PA 12, or other materials of this group; Polyolefins, such as polyethylenes (PE), ethylene copolymers (EVA, EMA, etc.) or mixtures of these, polypropylene (PP), PP copolymers or other thermoplastic polyolefins; Biopolymers based on renewable raw materials, such as starch polymers, of polylactic acid (PLA), of lignin-based polymers, of polyhydroxyalkanoates (PHAs), of corresponding mixtures or compounds, of biodegradable / com postible raw materials, such as special ones Bio-polyesters; or combinations thereof; and - The laminating adhesive (10) is selected from wet laminating adhesives, dispersion adhesives, Trockenkaschierklebern, solvent-free adhesive systems, cold seal adhesives or extrusion-coated lamination.

14. From a composite film (20) according to one of claims 1 to 13 prepared board (1 1) for firing of containers.

15. Circuit board (1 1) according to claim 14, characterized in that the board (1 1) on the side of the barrier layer (2) and / or on the side of the carrier layer (1) has a sealing area for sealing with the container.

16. An apparatus for producing a composite film (20) with at least one carrier layer (1) of a carrier material (8), at least one barrier layer (2) of a barrier film (9), and at least one intermediate Kaschierkleberschicht (3), wherein the device has a Carrier material supply (12), a laminating adhesive application (13), a barrier film supply (14) and a pressing device (15), wherein at least the carrier layer (1), the laminating adhesive layer (3) and the barrier film (9) of the pressing device (15 ) are at least partially pressed together for laminating, characterized in that between the barrier film feed (14) and the pressing device (15) an expansion member (16) for introducing a Dehnmusters (30) from stretched stretching areas (6) in the barrier film (9) is provided ,

17. The apparatus according to claim 16, characterized in that the expansion member (16) by the meshing profiles of a positive profile roller (17) and a negative profile roller (18) is formed, between which the barrier film (9) is guided.

18. The apparatus according to claim 17, characterized in that the pressing device (15) as a against the negative profile roller (18) pressing pressure roller (19) is formed, between which the composite film (20) to be pressed material is passed.

19. Device according to claim 17 or 18, characterized in that the positive profile roller (17) has a regular or irregular arrangement on raised embossing pins (27d) and the negative profile roller (18) has corresponding recesses (26d) into which the embossing pins (32) intervention.

20. A method for producing a composite film (20) having at least one carrier layer (1) of a carrier material (8), at least one barrier layer (2) of a barrier film (9) and at least one intermediate Kaschierkleberschicht (3), characterized in that before the laminating an expansion pattern (30) from stretched stretched areas (6) is introduced into the barrier film (9), and then the barrier film (9) as a barrier layer (2) is laminated on the carrier layer (1) and that caused by the stretching or a partially elastic recovery after stretching deformation of the barrier film (9) produces a raised pattern (31) on the composite film (20) the barrier layer (2) in the region of the raised pattern (31) on the side facing the carrier layer (1) after laminating has surfaces which are not connected to the carrier layer (1).

21. A method according to claim 20, characterized in that the barrier film (9) for introducing the Dehnmusters (30) between a positive profile roller (17) and a negative tivprofilwalze (18) is guided with intermeshing profiles.

22. The method according to claim 21, characterized in that the composite of carrier layer (1), Kaschierkleberschicht (3) and barrier layer (2) between the negative profile roller (18) and a pressure roller (19) is pressed.

23. The method according to claim 22, characterized in that the lamination between the negative profile roller (18) and a pressure roller (19), wherein the time interval between embossing and lamination by the radial position of the contact point between the pressure roller (19) and negative profile roller ( 18) and the peripheral speed of these rolls is determined.

24. The method according to any one of claims 20 to 23, characterized in that the raised pattern (31) from the Dehnmuster (30) differs.

25. The method according to claim 24, characterized in that the formation of the raised pattern (31) via delivery of the roller pair and / or the time interval between embossing and laminating is regulated.

26. The method according to any one of claims 20 to 25, characterized in that the laminating takes place while the barrier film (9) after insertion of the elongation pattern partially elastically reshaping.