Layered structure with improved recyclability

Abstract

The present invention relates to a layer structure (10; 210; 310) comprising an adhesion layer (22; 222; 322), a paper layer (14; 214; 314), and a release layer (20; 220; 320) between the adhesion layer (14; 214; 314) and the paper layer (14; 214; 314), wherein the adhesion layer (22; 222; 322) contacts the release layer (20; 220; 320). According to the invention, the release layer (20; 220; 320) is applied to the paper layer (14; 214; 314) as a release varnish layer (20; 220; 320) and contacts the paper layer (14; 214; 314).

Description

[0001] The present invention relates to a layered structure comprising an adhesive layer, a paper layer, and a release layer between the adhesive layer and the paper layer, wherein the adhesive layer contacts the release layer. The planar layered structure of the present invention is defined in claim 1.

[0002] A layer structure within the meaning of the present application is a layer composite which comprises the layers and layers attributed to it in the present application or consists of these layers.

[0003] Such layered structures can be applied to any surface, depending on the design of the adhesive layer. A preferred area of ​​application is in the packaging industry, where such layered structures are applied to packaging as labels. Regardless of the material and shape of the packaged goods, packaging can provide a relatively uniform outer surface in terms of surface properties and surface material for the application of the layered structure. This allows one type of layered structure to be applied to a variety of packaging to label different packaged goods.

[0004] Known layer structures of the type mentioned above often have a layer of oriented polypropylene (oPP) between the paper layer and the release layer. The release layer is then a primer layer, which ensures sufficient adhesion of the adhesive layer to the oPP layer and thus to the composite of the paper layer and oPP layer.

[0005] The OPP layer serves as a substrate for the paper layer and stabilizes it, preventing unwanted tearing of the paper layer at the applied label. Since the layered structure is often applied to a material web from which packaging is only created after the layered structure has been applied, the layered structure is used during production of the paper layer. This is prevented in the prior art by the OPP layer, which reduces stresses induced by the packaging material during packaging production through elastic or plastic deformation and does not transfer them to the paper layer, or only to a reduced extent.

[0006] The disadvantage of these known layered structures is their difficulty in recycling, as the composite layer of paper and OPP layers is only recyclable at an undesirably high cost. Furthermore, the production of the composite layer is expensive.

[0007] EP 0 555 830 A1 discloses a water-based release coating composition for use in combination with a packaging material. The composition comprises an intimate mixture of a polyamide resin microdispersion and an antifoam agent.

[0008] WO 99 / 39989 A1 discloses a cold-seal package with structures in which two substrates or two parts of a substrate are sealed together using a contact adhesive that is essentially free of natural latex. The two substrates can be easily peeled from each other without significant damage to the substrates. Furthermore, once separated, the substrates generally cannot be resealed or secured. The cold seal formed by the adhesive between the substrates is therefore not resealable. The cold-seal package known from WO 99 / 39989 A1 is particularly well suited for the aseptic delivery of packaged goods, such as bandages, dressings, and the like.

[0009] From EP 2 789 461 A1, a laminated lithographic printing plate is known which contains an adhesive layer which is accessible to and insoluble in oleophilic printing inks and alkaline or acidic aqueous fountain solutions used during printing with the printing plate, as well as in alkaline or acidic aqueous developers used during development of the printing plate. This adhesive layer is also i.) soluble in an alkaline aqueous processing liquid when the developers and fountain solutions are acidic, ii.) soluble in an acidic aqueous processing liquid when the developers and fountain solutions are alkaline, iii.) fusible, or iv.) a dry adhesive-conforming layer with a hardness of 60 Shore A or less.

[0010] The adhesive layer allows delamination of the printing plate.

[0011] EP 0 976 580 A1 discloses a transfer label with a carrier part comprising a substrate provided with a release liner on each side. A transfer part is printed onto the substrate and provided with a pressure-sensitive adhesive. The transfer label according to EP 0 976 580 A1 can be fed from a roll or stack at high speed at relatively low temperatures and allows precise alignment with relatively simple application equipment at room temperature. The transfer labels can be permanently or removably applied to containers such as crates, glass or plastic bottles, metal beverage cans, and the like.

[0012] It is the object of the present invention to further develop the layer structure of the type mentioned at the outset in such a way that it can be used with the same quality in application but with improved recyclability.

[0013] The present invention achieves this object in a layer structure of the type mentioned at the outset in that the separating layer is applied to the paper layer as a release lacquer coating and contacts the paper layer.

[0014] The previously used OPP layer for stabilization is thus eliminated, and the release layer is applied directly to the paper layer as a release coating. The OPP layer thus eliminates the main obstacle to recycling the layered structure. The layered structure is therefore more sustainable than the state-of-the-art layered structure described above.

[0015] With the elimination of the OPP layer, a substrate stabilizing the integrity of the paper layer is eliminated. This stabilizing effect is now taken over by the release varnish coating. A particularly good stabilizing effect with simultaneous high adhesion to the paper layer is achieved according to the invention by the release varnish coating being a polyamide-based release varnish coating. The release varnish coating thus consists of more than 50 wt. %, preferably more than 80 wt. %, and particularly preferably more than 95 wt. % polyamide. The reference state is the dry state of the release varnish coating after its application. After evaporation of any solvent present during application, the release varnish coating can consist of 100 wt. % polyamide, disregarding unavoidable impurities.The release lacquer application layer may comprise at least one additive and / or at least one wax or a mixture of different waxes.

[0016] The release varnish coating layer can be applied particularly thinly in liquid form in one application process and then doctored off. Alternatively, the release varnish coating layer can be applied using a printing process. The advantage of the release varnish coating layer is that it achieves its desired technical effect even at low grammages. According to the invention, the release varnish coating layer is applied to the paper layer with an application weight of at least 1.0 g / m², preferably 1.5 g / m², particularly preferably at least 2 g / m². With an application weight of the release varnish coating layer of 1.5 g / m² or more on the paper layer, the inventors have found that the adhesion layer can be fully separated from the release varnish coating layer, and thus also from the paper layer. In particular, this separability allows the adhesion layer to be separated from the paper layer without generating fiber tears in the paper layer.With an application weight of the release varnish layer of 1.0 g / m² to 1.5 g / m² on the paper layer, a crack-free separation of the adhesion layer from the paper layer can also be achieved. However, this can also result in minor fiber tears in the paper layer, although these are acceptable for certain applications. As already mentioned at the beginning, the paper layer is preferably pre-coated at least on the side where the release varnish layer is applied and, moreover, is particularly smooth. Such a paper layer supports the reduction and / or prevention of fiber tears in the paper layer, which can occur during the above-described separation of the adhesion layer from the release varnish layer or from the paper layer, particularly when using a paper layer that is not pre-coated on the side where the release varnish layer is applied and / or is less smooth on this side.This applies to the application weights of the release lacquer layer described above, in particular in the range of low application weights of 1.0 g / m 2< to 1.5 g / m 2< .

[0017] Likewise, particularly thick release coatings are not required. To ensure that the predominant component of the layer structure is easily recyclable paper, the release coating layer must be applied to the paper layer with a coating weight of no more than 5 g / m², preferably no more than 3 g / m². The coating weight of the release coating layer is preferably in the range of 1 to 5% of the basis weight of the paper layer.

[0018] Likewise, the application weight of the adhesion layer is preferably greater than that of the release coating layer and smaller than the basis weight of the paper layer.

[0019] The basis weights given in this application for a layer or layer refer to the dry or cured state of the respective layer or layer.

[0020] Preferably, the paper layer is pre-coated at least on the side of the application of the release varnish application layer in order to achieve a certain smoothness of the paper layer side facing the release varnish application layer and thus to prevent penetration of release varnish into the fiber structure of the paper layer.

[0021] For a stable layer structure with high component integrity, it is advantageous if the adhesive force between the release coating layer and the paper layer is greater than between the release coating layer and the adhesion layer.

[0022] Furthermore, the adhesive force between the release lacquer coating layer and the adhesion layer is lower than between the adhesion layer and a packaging material layer to which the layered structure is applied. This makes it possible to provide a type of tamper-evident seal that indicates whether a package provided with the layered structure has been tampered with in the region of the layered structure. The present invention therefore also relates to an arrangement comprising a layered structure described in the present application, which is applied to a packaging material layer. Such arrangements are described generally below. The packaging material layer, which can be part of a packaging material layer composite, can be a packaging material layer before or after the production of a package therefrom.

[0023] Due to this latter adhesion relationship, after the layer structure has been applied to a packaging material layer and after the layer structure has been removed from it again, the adhesive layer remains at least partially, preferably completely, on the packaging material layer. This makes any manipulation of the packaging material layer in the area of ​​a previously applied layer structure easily detectable by anyone.

[0024] In case of doubt, the adhesion between those contacting layers is considered to be greater between which a greater force must be applied to separate them when otherwise the same delamination technique is used.

[0025] The detectability of a tampering as described above can be further increased by the adhesive layer containing color pigments. White and black are considered colors within the meaning of the application. The adhesive layer can be an adhesive layer composite consisting of at least two separately produced adhesion layers. The adhesion layers are preferably formed from the same adhesion polymer, but can also be formed from different, but compatible, adhesion polymers. In the case of an adhesion layer composite as the adhesion layer, according to an advantageous development of the present invention, only some of the adhesion layers can contain color pigments, while at least one adhesion layer is free of color pigments. Likewise, at least two adhesion layers can be provided, each of which contains color pigments of a different color.

[0026] The adhesive layer is preferably a heat-sealing layer that can be bonded to a specific substrate by heating it to a specific sealing temperature and pressing it onto the substrate with a specific sealing pressure for a specific sealing time. This substrate is generally a heat-sealing layer made of a material that is compatible with the material of the heat-sealing layer for producing an adhesive bond. The resulting seal seam strength can be adjusted within certain limits in a manner known per se by changing, in particular, the sealing time and / or the sealing pressure. The heat-sealing layer is preferably sealable against any desired materials, in particular paper, PET, PP, PS, overprint varnishes, and the like.

[0027] Alternatively, the adhesive layer can be a cold-adhesive layer, especially a cold-sealing layer, which generally adheres to any substrate. If the adhesive layer is a cold-adhesive layer, it is usually covered with a release film to prevent unwanted blocking. Silicone-coated paper, for example, can be used as a release film.

[0028] To achieve a particularly high absolute adhesive force with a given line-related seal seam strength, the adhesion layer can be bonded over its entire surface to the substrate, in particular to a packaging material layer. If easier detachment of the layer structure from its substrate is desired, the adhesion layer can be applied only partially to the release coating layer, leaving certain areas unaffected, to reduce the overall adhesion of the layer structure to the substrate. Areas of the release coating layer and the paper layer left unaffected by the adhesion layer can also serve as information carriers for information that is only intended to be available after the layer structure has been removed from the substrate, for example, after the purchase of a labeled packaging product, as may be the case in a competition.

[0029] The paper layer preferably has a basis weight of 40 g / m 2 to 120 g / m 2 . In particular, the paper layer preferably has a basis weight of 70 g / m 2 to 120 g / m 2 , which has proven particularly advantageous for layered structures designed as adhesive labels. Basis weights in the range of 80 g / m 2 to 100 g / m 2 , particularly preferably 90 g / m 2 , are particularly preferred to avoid layered structures with excessive weight.

[0030] To provide information typically desired by layered structures, particularly those designed as labels or adhesive labels, about the origin and / or content and / or quality of a product provided with and / or labeled with the layered structure, the paper layer can have an ink application and / or a protective varnish layer on the side facing away from the release varnish application layer. The ink application is preferably a print ink application, with which information in text and / or image form can be applied to the visible side of the layered structure, which is immediately recognizable to the consumer. A protective varnish layer can protect the print ink application or the ink application in general from abrasion and deterioration.

[0031] To improve the recyclability of the layered structure, the layered structure preferably comprises only the aforementioned plies and layers. After removing the layered structure from its substrate, which usually leaves the adhesive layer on the substrate, the vast majority of the removed layered structure residue by weight is easily recyclable paper. Any residues of the adhesive layer remaining on the removed layered structure residue can be easily removed over large areas of the layered structure residue.

[0032] The adhesive layer is designed to adhere to a base material, in particular a packaging material layer.

[0033] The paper layer may have a visible side, with the release coating layer being applied to a side of the layer structure facing away from the visible side of the paper layer, in particular with respect to a thickness direction of the layer structure. In this case, the adhesion layer, in particular, is applied flatly to the release coating layer.

[0034] According to the invention, the layer structure is formed in a flat manner.

[0035] For the purposes of this application, "flat" refers to structures and / or layers whose dimensions in the thickness direction are significantly smaller, in particular at least by a factor of 20 to at least 100, than their dimensions orthogonal to the thickness direction. Preferably, the adhesion layer and / or the paper layer and / or the separating layer and / or the release coating layer and / or the print coating and / or the protective coating layer are flat.

[0036] The layered structure has the adhesion layer as the outermost layer in relation to the thickness direction of the layered structure. The adhesion layer can form the outermost layer only in sections, i.e., in a pattern-like manner, leaving out surface areas of the adhesion layer, but preferably over the entire surface.

[0037] The layered structure can be a lid for a container, in particular a paper lidding film or a cardboard lid, and / or an adhesive label or a material web, wherein the material web is preferably designed to be used in the production of a packaging or a label or adhesive label.

[0038] The layered structure discussed here can be produced particularly cost-effectively, as it can be formed simply by applying liquid or pasty layers to the paper layer. Thus, the layered structure can be formed solely by coating and / or printing the paper layer. The layered structure is completed when the wet or pasty layers dry. The lamination step is not required to produce the layered structure. Therefore, the layered structure can advantageously be produced in a single machine during one pass of a paper web along the paper web.

[0039] The present invention therefore also relates to a method for producing a layered structure as described and further developed above. The method of the present invention is defined in claim 10.

[0040] Before coating the release varnish with adhesion material, it is advantageous to dry the release varnish along a drying line. A heat-sealing dispersion is the preferred sealing varnish and is applied as an adhesion material to the release varnish coating layer.

[0041] The method may further comprise the step of printing the other side of the paper web with at least one printing ink. The side of the paper web to which no release coating is applied is printed.

[0042] The paper web can be printed with the at least one printing ink before, simultaneously with, or after the release coating is applied. Likewise, the paper web can be printed with the at least one printing ink before, simultaneously with, or after the release coating is applied.

[0043] As already explained above, the method for protecting the ink applied during printing may include coating the ink with a protective varnish.

[0044] Particularly preferably and economically advantageously, the layer structure is produced during a single pass of a paper web through an application device with several application stations.

[0045] Furthermore, the present invention relates to an arrangement, in particular to a packaging, comprising an outer material and a lower material, wherein the layered structure according to the invention is the upper material. The adhesive layer of the layered structure adheres to the lower material, in particular over the entire surface or only in sections. The layered structure can be applied to the lower material as the upper material. In particular, the layered structure forms an outer side of the arrangement.

[0046] The base material is preferably formed separately from the layered structure. The base material can be a layer of packaging material and / or can be a plastic. The base material can form a section of a container, e.g., a cup or a tray. The base material can simply be a container wall onto which the layered structure can be arranged as an adhesive label for identifying the container. However, the layered structure can advantageously form a container closure that is easy and safe to open if the section of the base material is a collar that projects away from a container wall and surrounds a container opening. A collar is, in particular, a circumferential projection that projects in at least one direction orthogonal to the circumferential direction, preferably radially.To facilitate the attachment of the adhesion layer of the layer structure to a preferably flat surface of the collar, the collar preferably projects radially outwards or radially inwards from the container wall without an axial extension component, and preferably outwards to facilitate emptying of the cup.

[0047] The packaging can be a bag, which can be formed entirely from the layered structure. Likewise, only one wall of the bag can be a layered structure, which is sealed against another packaging material layer of the bag, separate from the layered structure and structurally different from it, as the base material. The separate packaging material layer can alternatively be a layered structure according to the invention. However, the packaging material layer as the base material can also be part of the layered structure itself by folding the layered structure onto itself, then with the adhesion layers facing one another. In this case, a continuous section of the layered structure according to the invention surrounds a cavity of a packaging.

[0048] As already explained above, a partial structure extending from the exposed outer side of the layer structure up to and including the release lacquer application layer can be peeled off from the base material as a release structure from the layer structure which is connected to a base material by means of its adhesion layer. As already explained above, a partial structure extending from the exposed outer side of the layer structure up to and including the release lacquer application layer can be peeled off from the base material as a release structure. The adhesion layer remains at least partially or preferably completely in the area in which it is connected to the base material. The release structure can be completely removable from the adhesion layer or only in a release area of ​​its surface extension designed for this purpose. For example, the layer structure can have a release lacquer application layer only in the release area and not in an area different from the release area.

[0049] If a cold-adhesive layer is used as the adhesion layer, an area of ​​the base material where exposed cold adhesive remains after the release structure has been detached from the base material can form an adhesive surface. If the arrangement is a package, the adhesive surface can preferably completely or partially surround a removal opening of the package, so that the part of the layer structure detached from the base material can form a resealable adhesive closure of the package.

[0050] The outermost layer of the base material to which a layer structure according to the invention adheres with its adhesion layer is hereinafter referred to as the contact layer. The contact layer can be the adhesion layer of the packaging material layer if this layer is also a layer structure according to the invention.

[0051] Likewise, if the packaging material layer is also a layer structure according to the invention, the visible side of the paper layer and / or a print job applied to the visible side of the paper layer and / or a protective lacquer layer applied to the visible side of the paper layer and / or to the print job can be the contact layer.

[0052] The layered structure may cover an opening in the base material, which may be part of a package, wherein the opening is preferably configured for removing a product from the interior of the package.

[0053] The layer structure may have a substantially uniform thickness over its entire surface area.

[0054] The release lacquer application layer can be applied in a patterned manner, leaving at least one region of the paper layer free, or alternatively, it can be applied over the entire surface of the paper layer. It can extend over the entire extent of the layer structure in at least one direction of the layer structure that is orthogonal to the layer structure thickness direction, from the longitudinal direction and / or the width direction. Likewise, a partial section of the layer structure, which is not intended to be a detachment section as described above, can be free of a release lacquer application layer over its entire extent in the thickness direction. This partial section can be delimited by at least one virtual surface, in particular a plane, that preferably runs essentially parallel to the thickness direction and intersects the layer structure. This virtual surface can furthermore run essentially parallel to the longitudinal direction or the width direction, at least in part or entirely.The dimension of the layered structure in its thickness direction may be smaller in this partial section than outside this partial section. This partial section preferably extends either over the entire dimension of the layered structure in the longitudinal direction or over the entire dimension of the layered structure in the width direction.

[0055] The packaging can be a bag, in particular for containing medical products, secondary packaging, a sachet pouch, or a sealed-edge flat bag. The layered structure can, for example, be sealed against various base materials (or adhere to these base materials) as a lidding film, in particular a non-rigid one, or as a lidding cardboard, in particular a rigid one. This allows containers providing base materials, such as cups or bowls, which are preferably made of plastic, to be sealed, thus forming closed packages.

[0056] Furthermore, the invention relates to a method for producing an arrangement according to the invention, in particular a package, comprising the following steps: providing a layered structure according to the invention, which is preferably an outer material, and sealing the layered structure against a base material. A "sealing" step is understood to mean a step of forming a connection between the layered structure and the base material, wherein this connection is formed by the adhesive layer and is thus, in particular, an adhesive connection. An outer material is, in particular, arranged on a base material.

[0057] The adhesive layer preferably has an application weight of no more than 9.0 g / m², measured on the dry or cured layer, on the release coating layer. If the layered structure adheres to a base material and the layered structure covers an opening in the base material, then at such application weights, when the layered structure is peeled off the opening, the adhesive layer tears along the circumference of the opening due to cracking. The opening is then released without a skin of adhesive layer closing the opening; in particular, the opening is released completely.

[0058] The adhesion layer is in particular a heat-sealing dispersion layer; it can be an EVAC dispersion layer, an acrylate dispersion layer, or a layer made of a solvent-based heat-sealing lacquer, e.g., based on polyester.

[0059] Values ​​and / or range limits of the application weights and / or basis weights stated in the application have in particular an error tolerance of +0.04 g / m 2< and -0.05 g / m 2<.

[0060] The present invention will be explained in more detail below with reference to the accompanying drawings. It shows: Fig. 1 a roughly schematic cross-sectional view through an embodiment of a layer structure according to the invention, applied to a packaging material layer, Fig. 2a a roughly schematic cross-sectional view through an embodiment of the layer structure according to the invention as a lid of a container and through an embodiment of an arrangement designed as packaging, Fig. 2b a roughly schematic cross-sectional view through a release structure and a container, Fig. 3 a top view of an embodiment of an arrangement designed as packaging, Fig. 4 a top view of an embodiment of an arrangement designed as packaging, Fig. 5 a top view of an embodiment of an arrangement designed as packaging, Fig. 6 a roughly schematic cross-sectional view of the AA section from Figure 5with a second embodiment of a layer structure according to the invention, and Fig. 7 a roughly schematic cross-sectional view of the AA section from Figure 5 with a third embodiment of a layer structure according to the invention.

[0061] The figures are not to scale.

[0062] In Figure 1 a layer structure according to the invention is generally designated 10. In the embodiment of the Figure 1 The layered structure forms an adhesive label. The layered structure 10 is sealed, in particular as an upper material, onto a packaging material layer 12, which in particular forms a lower material. The packaging material layer 12 can be the entire packaging material as a monolayer or can be part of a multilayer composite layer that forms the packaging material.

[0063] The layered structure has a paper layer as the most massive layer 14, which is also the layer with the highest basis weight. On its visible side 14a, the paper layer bears a print job 16 that is completely covered by a protective varnish layer 18 to protect it from external influences. The protective varnish layer 18 is preferably transparent so as not to affect the appearance of the print job 16.

[0064] In the example shown, the paper layer 14 has a basis weight of 90 g / m 2<.

[0065] On the side 14b facing away from the visible side 14a of the paper layer 14, a release coating layer 20 is applied as a separating layer. The release coating layer 20, which is based on polyamide and therefore predominantly contains polyamide, is applied with a preferred, but not only possible, basis weight of 2.5 g / m². This means that the dry release coating layer 20 formed on the layer structure weighs 2.5 g per square meter.

[0066] A heat-sealing layer 22 (or heat-sealing layer) is applied as a heat-sealing dispersion to the release coating layer 20 as the adhesion layer. The heat-sealing layer 22 is preferably a polyolefin and can be, for example, a polyethylene or polypropylene layer. In a further preferred embodiment, the heat-sealing layer 22 can comprise or be an ethylene-vinyl acetate and / or an ethylene-vinyl acetate copolymer.

[0067] The packaging material layer 12 can be formed from the same sealable material as the heat-seal layer 22, so that by heating them above the softening point and pressing them together, the heat-seal layer 22, and thus the layered structure 10 as a whole, can be bonded to the packaging material layer 12. The strength of the bond between the layered structure 10 and the packaging material layer 12 can be adjusted by the selected sealing temperature, the selected sealing pressure, and the selected sealing duration.

[0068] Preferably, the heat-sealing layer 22 is sealable against any materials, such as in particular against paper, PET, PP, PS, overprint varnishes and the like.

[0069] The application weight, again based on the dry state, of the heat-sealing layer 22 is preferably greater than the application weight (area weight) of the release lacquer application layer 20.

[0070] Due to the sealing connection, the heat-sealing layer 22 adheres with high adhesive force to the packaging material layer 12.

[0071] The adhesion of the heat-seal layer 22 to the release varnish coating layer 20 is lower than the adhesion of the release varnish coating layer 20 to the paper layer 14. This basically means that under the same release conditions, for example under the same type of delaminating peeling of one layer from another, a higher force is required to separate the release varnish coating layer 20 from the paper layer 14 than to separate the heat-seal layer 22 from the release varnish coating layer 20. Also, a higher force is generally required to separate the heat-seal layer 22 from the packaging material layer 12 than to separate the heat-seal layer 22 from the release varnish coating layer 20.

[0072] If an attempt is now made to detach the layer structure 10 applied to the packaging material layer 12 by sealing from the packaging material layer 12, a separation occurs between the release varnish application layer 20 and the heat-sealing layer 22, which remains on the packaging material layer 12. Thus, the heat-sealing layer 22 can be provided with color pigments as a tamper-evident seal in order to make a heat-sealing layer 22 remaining on the packaging material layer 12 after the layer structure 10 has been removed particularly easily recognizable. The color pigments of the heat-sealing layer 22 are preferably selected to contrast with color pigments in the packaging material layer 12 or in further packaging material layers located below the packaging material layer 12 and visible from the side of the layer structure 10.

[0073] The entire layered structure is free of laminated layers and is produced solely by applying liquid or pasty layers to the paper layer. The layered structure can advantageously be produced on a single machine during a single pass of a paper web through it. On one side 14a of the paper layer 14, the print coating 16 and the protective lacquer layer 18 are applied; on the opposite side 14b, the release lacquer coating layer 20 and the heat-sealing layer 22 are applied.

[0074] Figure 2a shows a closed package 24 comprising the packaging already described in connection with the Figure 1 described layer structure 10, which in this case forms a lidding film or a lidding cardboard, as well as a cup 26, for example made of plastic, with a collar 30 surrounding a cup opening 28, which extends outwards from an interior 32 of the cup 26. The adhesive layer 22 of the in Figure 2a The layer structure 10 used can, in contrast to the description of this structure in connection with the Figure 1be designed as a cold adhesive layer. The adhesion layer 22 adheres to an outward-facing surface 34 of the collar 30, so that the layered structure 10 closes the cup opening 28. If the layered structure 10 is peeled off the cup 26, the adhesion layer 22 separates from the release lacquer coating layer 20 in the region of the collar 30. Furthermore, the adhesion layer 22 separates, particularly at an application weight of no more than 9.0 g / m 2<, measured on the dry or cured layer, of the adhesion layer 22 on the release lacquer coating layer 20, by cracking along the circumference of the cup opening 28, as indicated by the dashed lines 36l, 36r.For each combination of release lacquer coating layer, adhesion layer, and the dimensions of the layered structure, as well as the dimensions and design of the areas where the layered structure adheres to a base material, a person skilled in the art can easily determine, through experiments, an application weight of the adhesion layer such that this effect occurs. This effect occurs particularly in the embodiment described here when the adhesion of the adhesion layer remaining on the layered structure residue after the layered structure 10 has been peeled off from the cup opening 28 to the release lacquer coating layer 20 is greater than the tear strength of the adhesion layer 22.

[0075] When the layered structure 10 is peeled off, the cup opening 28 is exposed. If the adhesive layer 22 is formed as a cold-adhesive layer, the cup opening 28 can be resealed by placing the peeled-off layered structure 10 on the remainder of the adhesive layer 22 remaining on the collar 30. The sections of the adhesive layer 22 that adhere to the surface 34 after the peeling described above and are exposed to the outside adhere, after resealing, to exposed sections of the release coating layer 20 of the peeled-off layered structure 10 or to sections of the adhesive layer 22 remaining on the peeled-off layered structure 10.

[0076] Figure 2bshows the cup 26 with sections 22l, 22m, 22r of the adhesion layer 22 adhering to the surface 34 and exposed to the outside, as well as a release structure 11, which is formed from the layered structure 10 by the above-described peeling of this layered structure 10 from the cup 26. The layers and plies of the release structure 11 are provided with the same reference numerals as those of the layered structure 10, and explicit reference is made to their description in connection with the layered structure.

[0077] Figure 3 shows a package 38 designed as a bag, which consists of two layers arranged one above the other of the Figure 1 described layer structure 10 is formed, wherein in Figure 3Only the layer 40 located on top in the view shown is shown. These layers are embodiments of packaging material layers and are arranged one above the other with mutually facing adhesion layers 22, each designed as a heat-sealing layer. The layer structures 10 of the layers are connected to one another along the outer circumference by a heat-sealing seam 42, so that the packaging 38 encloses a product accommodated in its interior. The respective adhesion layers 22 of the layers arranged one above the other are embodiments of contact layers mentioned in the introduction to the description.

[0078] The adhesion layer 22 of the Figure 3 The layer structure 10 used for the layers can, in contrast to the description of this structure in connection with the Figure 1be designed as a cold adhesive layer. The layer structures 10 of the layers are then connected to one another along the outer circumference by a cold seal seam 42', whereby this alternative is also Figure 3 This 42' cold seal seam can be opened and resealed in the usual way.

[0079] Figure 4 shows a bag-shaped embodiment of a package 138 which incorporates many aspects of the Figure 3described embodiment of the packaging 38 made of layers with layered structures 10, in which the adhesion layer 22 is a heat-sealing layer. Only the differences between the packaging 138 and the packaging 38 are described below. Elements and sections of the packaging 138 that correspond to those of the packaging 38 are provided with a reference numeral increased by 100 with respect to the corresponding elements or sections of the packaging 38, and explicit reference is made to the corresponding description of the packaging 38. This does not apply to the use of the reference numerals for the described layered structure 10 and its plies and layers.

[0080] In the embodiment of the Figure 4The layer 140 has an opening 144, which allows access to the interior of the packaging 138. The opening 144 is covered by a cover 146 formed from a layer structure 10. In this case, the protective lacquer layer 18 of the layer structure 10 of the layer 140 is the contact layer of the layer 140. The cover 146 is an embodiment of a paper lidding film and an upper material, and the layer 140 is an embodiment of a lower material. When the cover 146 is peeled off from the layer 140, the adhesive layer 22 of the cover 146 separates essentially along the circumference of the opening 144 due to cracking, and a portion of the adhesive layer 22 of the cover 146 remains on the contact layer of the layer 140 due to the separation of the adhesive layer 22 of the cover 146 from the release lacquer application layer 20 of the cover 146.If, instead of a heat-sealing layer, a cold-adhesive layer is used as the adhesive layer 22 of the layered structure 10 of the cover 146, this portion of the adhesive layer 22 of the cover 146 remaining on the contact layer forms an exposed adhesive surface. This adhesive surface can be used to close the opening 144 by attaching the cover 146 or by a portion of the packaging 138, wherein the portion of the packaging 138 can be brought into contact with the adhesive surface by folding this packaging 138 over the opening 144. This creates a resealable adhesive closure of the packaging 138.

[0081] Figure 5 shows an embodiment of a package 238 designed as a bag, which is formed from two layers of packaging material arranged one above the other, possibly essentially identical except for the print. In Figure 5only the packaging material layer 212 located on top in the view shown is shown. These packaging material layers can be monolayers made of plastic. These packaging material layers are connected to one another along the outer circumference by a heat-sealed seam 242, so that the packaging 238 encloses a good accommodated in its interior. The packaging material layer 212 has an opening 244, which allows access to the interior of the packaging 238. The opening 244 is covered by a cover 246 formed from a layer structure 210 or 310, as is shown in relation to the Figure 6 and 7 is described in each case.

[0082] Figure 6 shows a second embodiment of a layer structure 210, which forms the cover 246 and is applied to the packaging material layer 212. The layer structure 210 corresponds in many aspects to the one shown in Figure 1described embodiment of the layer structure 10. Unless otherwise stated, only the differences between the layer structure 210 and the layer structure 10 are described below. Elements and sections of the layer structure 210 that correspond to those of the layer structure 10 are provided with a reference numeral increased by 200 with respect to the corresponding elements or sections of the layer structure 10, and explicit reference is made to the corresponding description of the layer structure 10.

[0083] The layer structure 210 of the cover 246 is, like the layer structure 10, flat and extends in a longitudinal direction L, a width direction B, which in Figure 6 perpendicular to the plane of the drawing, and a thickness direction D, which is Figure 5runs perpendicular to the plane of the drawing. In these layer structures 10, 210, the adhesion layer is spaced from the protective lacquer layer in the thickness direction D. In a partial section TA, the layer structure 210 is free of a release lacquer application layer in the thickness direction D. The partial section TA of the layer structure 210 is delimited from the partial section TB of the layer structure 210 forming the remainder of the layer structure 210 by a plane K which runs perpendicular to the longitudinal direction L and parallel to the thickness direction D.

[0084] The layer structure 210 has a constant dimension H0 in the thickness direction across its entire surface extent. This is achieved by the adhesion layer 222 having a dimension H1 in the thickness direction D in the partial section TA, which is equal to the sum of the dimension H2 of the adhesion layer 222 in the thickness direction D in the partial section TB and the dimension H3 of the release coating layer 220 present in the partial section TB. The adhesion layer 222 has different dimensions H1, H2 in the thickness direction D along a direction of extent of the layer structure 210, here, for example, the longitudinal direction L.

[0085] If the cover 246 is now removed in the removal direction P, the adhesive layer 222 separates from the release lacquer coating layer 220. The adhesive layer 222 separates along the circumference of the opening 244 by cracking and a section of the adhesive layer 222 remains on the packaging material layer 212 forming a base material, as already described with regard to the embodiment of the Figure 4explained. The separation of the adhesion layer 222 from the release lacquer application layer 220 begins during peeling in the peeling direction P at a first end section 248 of the layer structure 210. As soon as this separation reaches the end of the release lacquer application layer 220 lying on the plane K, the person peeling off the cover 246 feels increased resistance because the adhesive force between the adhesion layer 222 and the paper layer 214 is greater than the adhesive force between the release lacquer application layer 220 and the adhesion layer 222. Preferably, when the cover 246 is peeled off in the peeling direction P along the plane K, a crease line forms in the layer structure 210, at which the cover 246 bends.If the adhesive layer 222 is a cold adhesive layer, the exposed adhesive layer 222 remaining on the packaging material layer 212 after the cover 246 has been removed forms an adhesive surface to which the cover 246 can adhere again and close the opening 244 again.

[0086] Figure 7 shows a third embodiment of a layer structure 310, which forms the cover 246 as an alternative to the layer structure 210 and is applied to the packaging material layer 212. The layer structure 310 corresponds in many aspects to the layer structure 310 shown in Figure 6described embodiment of the layer structure 210. Unless otherwise stated, only the differences between the layer structure 310 and the layer structure 210 are described below. Elements and sections of the layer structure 310 that correspond to those of the layer structure 210 are provided with a reference numeral increased by 100 with respect to the corresponding elements or sections of the layer structure 210, and explicit reference is made to the corresponding description of the layer structure 210.

[0087] In contrast to the layered structure 210, the dimension of the layered structure 310 is not the same across its surface extension in the thickness direction D. In the partial section TA, this dimension H4 of the layered structure 310 in the thickness direction D is smaller than the dimension H5 of the layered structure 310 in the thickness direction D in the partial section TB. The dimension H6 of the adhesion layer 322 in the thickness direction D is essentially the same in the partial sections TA and TB. The dimension H5 is larger than the dimension H4 by the dimension H7 of the release coating layer 320. If the cover 246 is adhered to the packaging material layer 212, a step 350 is formed, which is purely schematic and exaggerated for reasons of clarity of illustration. The step 350 can, as in the Figure 7indicated, be formed essentially in the packaging material layer 212, or, as outlined by the lines 352, 354 indicating an outer surface profile of the layer structure, be formed essentially in the cover 246. For the sake of clarity, the change in the profile of the packaging material layer 212 is not shown in the Figure 7 Alternatively, the step 350 can be formed in both the packaging material layer 212 and the cover 246.

[0088] For better perception, level 350 is a jump in the Figure 7shown schematically. In fact, the step 350, as well as any steps possibly present in the packaging material layer 212, the adhesion layer 322, and / or the entire layered structure 310 or its layers and / or layers, are not formed as a jump, but rather as a deviation of the course of these layers, layers, and / or structures from a straight or flat course extending over a certain length in the longitudinal direction L.

Claims

1. Planar stratum structure (10; 210; 310) comprising an adhesion layer (22; 222; 322), a paper layer (14; 214; 314) and, between the adhesion layer (22; 222; 322) and the paper layer (14; 214; 314), wherein the adhesion layer (22; 222; 322) contacts the separation layer (20; 220; 320), wherein the separation layer (20; 220; 320) is applied as a release lacquer application stratum (20; 220; 320) to the paper layer (14; 214; 314) and contacts the paper layer (14; 214; 314), wherein the release lacquer application stratum (20; 220; 320) is a release lacquer application stratum (20; 220; 320) based on polyamide, and wherein the release lacquer application stratum (20; 220; 320) is applied to the paper layer (14; 214; 314) with an application weight of at least 1.0 g / m2, and wherein the release lacquer application stratum (20; 220; 320) is applied to the paper layer (14; 214; 314) with an application weight of not more than 5 g / m2.

2. Planar stratum structure (10; 210; 310) according to claim 1, characterized in that the adhesive force between the release lacquer application stratum (20; 220; 320) and the paper layer (14; 214; 314) is greater than between the release lacquer application stratum (20; 220; 320) and the adhesion layer (22; 222; 322).

3. Planar stratum structure (10; 210; 310) according to one of the preceding claims, characterized in that the adhesion layer (22; 222; 322) contains color pigments.

4. Planar stratum structure (10; 210; 310) according to one of the preceding claims, characterized in that the adhesion layer (22; 222; 322) is a heat-sealing layer (22; 222; 322) or a cold adhesive layer.

5. Planar stratum structure (10; 210; 310) according to one of the preceding claims, characterized in that the adhesion layer (22; 222; 322) is applied over the entire surface or only partially, with areas of the surface being left free, to the release lacquer application stratum (20; 220; 320).

6. Planar stratum structure (10; 210; 310) according to one of the preceding claims, characterized in that the paper layer (14; 214; 314) has a weight per unit area of 40 g / m2 to 120 g / m2, preferably 80 g / m2 to 100 g / m2, particularly preferably 90 g / m2.

7. Planar stratum structure (10; 210; 310) according to one of the preceding claims, characterized in that the paper layer (14; 214; 314) on the side facing away from the release lacquer application stratum (20; 220; 320) (14a; 214a; 314a) has an ink application (16; 216; 316) and / or a stratum of protective lacquer (18; 218; 318).

8. Planar stratum structure (10; 210; 310) according to one of the preceding claims, characterized in that the stratum structure (10; 210; 310) only has the mentioned layers and strata (14, 16, 18, 20, 22; 214, 216, 218, 220, 222; 314, 316, 318, 320, 322) and / or that the stratum structure (10; 210; 310) is formed only by applying liquid or paste-like strata to the paper layer (14; 214; 314).

9. Planar stratum structure (10; 210; 310) according to one of the preceding claims, characterized in that the stratum structure (10; 210; 310) is a lid for a container and / or an adhesive label or a material web.

10. Method for producing a planar stratum structure (10; 210; 310) according to one of the preceding claims, comprising the following steps: - transporting a paper web (14; 214; 314) through an application device, - during transport, applying a polyamide-based release lacquer to one side (14b) of the paper web (14; 214; 314) with an application weight of at least 1.5 g / m2 and with an application weight of not more than 5 g / m2, - coating the release lacquer with an adhesive material.

11. Method according to claim 10, characterized by the following further method steps: - printing the other side (14a; 214a; 314a) of the paper web (14; 214; 314) onto which no release lacquer is or has been applied with at least one printing ink, - optionally: coating the printing ink application (16; 216; 316) with a protective lacquer.

12. Arrangement comprising a planar stratum structure (10; 210; 310) according to one of claims 1 to 9 and a base material, wherein the adhesion layer (22; 222; 322) of the stratum structure (10; 210; 310) adheres to the base material.

13. Method for producing an arrangement according to claim 12, comprising the following steps: - providing a planar stratum structure (10; 210; 310) according to one of claims 1 to 9, and - sealing the planar stratum structure (10; 210; 310) against a base material.

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