Laminate and method for producing a laminate

Abstract

The invention relates to a laminate (1) comprising a security element (20) which is incorporated by lamination between a recording layer (11) and a cover layer (12), an adhesive layer (25) adhering to the recording layer (11) and a release layer (21) adhering to the cover layer (12), or the adhesive layer (25) adhering to the cover layer (12) and the release layer (21) adhering to the recording layer (11), and the laminate (1) being designed such that the adhesive layer (25) of the security element (20) can be split by a tensile force exerted by the recording layer (11) and the cover layer (12) onto the security element (20). The invention also relates to a method for producing a laminate (1).

Description

[0001] Laminate and method for producing a laminate

[0002] The invention relates to a laminate and a method for producing a laminate.

[0003] It is known to enclose security elements in laminates, such as security documents, between two layers that are materially bonded to one another, so that the security element is completely enclosed by these two layers of the security document. The materially bonded structure achieves a high adhesive strength and protects the security element from damage and tampering. However, due to the different material properties of the layers of the security element and the adjacent materially bonded layers of the security document, different interfaces with different adhesive strengths are created, and in particular with reduced adhesive strength at the interfaces of the security element. If the security element has different adhesive forces at its interfaces to the materially bonded layers, this can be exploited by counterfeiters to deliberately delaminate or break the security element.Peeling back the layers of the security document to remove the security element or adding false information to the security document and resealing it.

[0004] It is therefore an object of the present invention to provide a laminate, in particular a security document, which has improved protection against manipulation and forgery, and to provide a method for its production. This object is achieved by means of a laminate, in particular a security document, according to claim 1. The laminate, in particular a security document, comprises a recording layer, a transparent cover layer, and a security element laminated between the recording layer and the cover layer. The security element has a release layer, a replication layer with a relief surface arranged on its side facing away from the release layer, a reflection layer arranged on the relief surface, and an adhesive layer.The adhesive layer forms a side of the security element facing away from the release layer, wherein a) the adhesive layer adheres to the recording layer and the release layer adheres to the cover layer or the adhesive layer adheres to the cover layer and the release layer adheres to the recording layer.

[0005] In addition, b) the laminate is designed in such a way that the adhesive layer of the security element can be split by a tensile force exerted on the security element by the recording layer and the cover layer.

[0006] The object is further achieved by a method according to claim 31. In the method for producing a laminate, in particular a

[0007] Security document, preferably according to one of claims 1 to 30, the following steps are carried out, in particular in the specified order:

[0008] - Providing a recording layer;

[0009] - Providing a transparent cover layer;

[0010] - Providing a security element, in particular a security element as described for the laminate according to the invention, preferably in one of claims 1 to 30. The security element comprises a release layer, a replication layer with a relief surface arranged on its side facing away from the release layer, a reflection layer arranged on the relief surface, and an adhesive layer forming a side of the security element facing away from the release layer. The security element is or is attached to the cover layer or the recording layer with the adhesive layer;

[0011] - Laminating the security element between the recording layer and the cover layer in such a way that a) the adhesive layer adheres to the recording layer and the release layer adheres to the cover layer or the adhesive layer adheres to the cover layer and the release layer adheres to the recording layer and b) the adhesive layer of the security element can be split by a tensile force exerted on the security element by the recording layer and the cover layer.

[0012] The adhesive layer of the laminate according to the invention and of the laminate obtainable by the process according to the invention can be split into itself by means of a cohesive failure, in particular by a tensile force exerted on the security element by the recording layer and the cover layer. The presence of a splittable adhesive layer within the meaning of the present invention can be determined in particular by the peel tests described below. A cohesive failure is in particular the failure of the bond in the adhesive itself, preferably where the adhesion of the adhesive to the material surface is greater than the internal strength of the adhesive. In the event of a cohesive failure in the adhesive layer, in particular a separation of the adhesive layer into two partial layers takes place, wherein the separated partial layers of the adhesive layer each remain adhered to the directly adjacent layers adjacent to the adhesive layer.In particular, the two partial layers are each cohesive layers that are or will be separated from each other by the cohesive failure, with a pure cohesive failure preferably occurring. It is possible that during the cohesive failure, a propagating crack tip briefly encounters the interface of the layers adjacent to the adhesive layer, but does not run along it as the separation progresses, for example, so that the adhesive layer, after separation, is present in the form of incompletely cohesive partial layers and / or so that the adhesive layer, after separation, is present in the form of predominantly cohesive partial layers.In the case of an adhesive failure, however, the adhesive layer detaches, in particular at the interface to one or more of the layers directly adjacent to the adhesive layer and adjacent to the adhesive layer, in particular so that the adhesive layer is detached from the interface in a continuous or predominantly continuous manner due to the adhesive failure.

[0013] The presence of a splittable adhesive layer makes undetectable detachment or reuse of the security element as a whole more difficult. This is because when the cover layer is removed, part or a partial layer of the adhesive layer is also removed due to the splitting of the adhesive layer, in particular due to cohesive failure of the adhesive layer. This reduces the layer thickness of the security element and, in particular, leaves plastic deformations of the adhesive layer on the surface of the security element. This makes any attempt at tampering easier to detect, or the detectability can only be reduced with additional effort. Studies have also shown that the splittable adhesive layer orby means of a corresponding predetermined breaking point defined by the adhesive layer, an increased removal force, preferably also referred to as peel force, can be achieved, which is necessary when attempting to detach the cover layer or the recording layer from the security element. Delamination of the laminate and non-destructive reuse of the security element are consequently made more difficult due to the prevailing adhesive force conditions. In this way, a particularly high adhesive force can also be achieved both at the interface of the adhesive layer and at the interface of the release layer to the adjacent recording layer or the adjacent cover layer, whereby in particular the difference between the adhesive forces at the two interfaces of the adhesive layer can be adjusted and the difference can be reduced in such a way that an easily controlled, successive detachment of layers of the security document is made more difficult.

[0014] The process according to the invention is used, in particular, to produce the laminate according to the invention. The process according to the invention is thus preferably carried out to obtain the laminate according to the invention.

[0015] Advantageous embodiments of the invention are described in the subclaims.

[0016] “Adherence” is preferably understood to mean a direct connection. Preferably, the adhesive layer adheres directly to the recording layer, with the release layer adhering directly to the cover layer, or the adhesive layer adheres directly to the cover layer, with the release layer adhering directly to the recording layer. In particular, the adhesive force of two layers adhering to one another is above a value of 1 N / 10 mm strip width, preferably above 1.5 N / 10 mm strip width, more preferably above 3.5 N / 10 mm strip width, measured according to the standard ISO / IEC 10373-1:2006(E); paragraph 5.3 and / or the peel test below. In further embodiments, intermediate layers can be arranged between the adhesive layer and the recording layer.

[0017] A layer is understood to mean, in particular, an essentially flat structure. A layer itself can preferably be single- or multi-layered.

[0018] A laminate is understood, in particular, to be a multilayer structure in which at least two layers are integrally bonded to one another, in particular welded. For example, a laminate is or is produced using a lamination process. The lamination process can be carried out as described further below. Laminated or lamination is understood, in particular, to mean that a bonded composite, in particular of the recording layer and the cover layer, is or will be produced, preferably using a lamination process, preferably such that the security element is completely enclosed by the two layers.The security element is or will be laminated in particular by the recording layer and the cover layer being or will be welded together and thereby preferably completely enclosing the security element, preferably when viewed perpendicular to a plane or main surface spanned by the laminate and / or the security element.

[0019] A plane or main surface is preferably understood to mean the surface spanned by the laminate or the security element or one of the layers of the laminate and / or the security element, if its thickness is neglected.

[0020] “Transparent” preferably means a transmittance of more than 90%, in particular wavelengths in a range from 380 nm to 780 nm, preferably for wavelengths in the wavelength range visible to the human eye.

[0021] “Semi-transparent” preferably means a transmittance in a range of 30% to 90%, in particular wavelengths in a range of 380 nm to 780 nm, preferably for wavelengths in the wavelength range visible to the human eye.

[0022] "Opaque" preferably means a transmittance of less than 30%. Transmittance is preferably understood as the ratio of the amount of light radiating and / or incident on a medium to the amount of light exiting on the opposite side of the medium, with, in particular, no change in the frequency or wavelength of the light having occurred. The non-transmitted light is preferably reflected, scattered, and / or absorbed by the medium. For example, with a transmittance of a medium of 0.9 or 90%, 90% of the incident light is perceptible on the opposite side of the medium.

[0023] When considering the transmittance of a layer, reflections at the interfaces of this layer are not taken into account.

[0024] It is possible for a security element to provide an optically variable effect. An optically variable effect can be selected, in particular individually or in combination, from: viewing angle-dependent color change, viewing angle-dependent contrast change, viewing angle-dependent motif change, holographic display, cinematic display. The viewing angle of the security element can be varied by a viewer, in particular by tilting, rotating, and / or bending. Preferably, a security element is or will be formed as or from a transfer layer of a transfer film.It is possible that one or more security elements with an adhesive layer adhering to the recording layer and a release layer adhering to the cover layer and one or more further security elements with an adhesive layer adhering to the cover layer and a release layer adhering to the recording layer are or will be laminated into a security document.

[0025] The recording layer and / or the cover layer preferably comprises or consists of polycarbonate. It is particularly advantageous if the recording layer and the cover layer comprise or consist of polycarbonate and are or will be materially bonded to one another, in particular welded together, by means of lamination. In this way, a particularly stable bond can be achieved during lamination. The cover layer preferably has a layer thickness in a range from 25 μm to 250 μm and / or the layer thickness of the cover layer is in a range from 1.25 to 250 μm in relation to the layer thickness of the adhesive layer and / or the sum of the thickness of the adhesive layer and the thickness of the cover layer is in a range from 26 μm to 270 μm.

[0026] The cover layer and / or the recording layer can, for example, in addition to polycarbonate, also comprise dyes, in particular color pigments and / or effect colors, for example with optically variable pigments (OVI) and / or with metal pigments.

[0027] It is preferred that the recording layer has a thickness in a range from 25 μm to 250 μm. The recording layer is, in particular, processable by means of a laser or is processed by means of a laser. The recording layer preferably comprises further substances, such as, in particular, a dopant. The dopant can increase the energy absorption capacity of the recording layer. Materials for doping are, in particular, selected from one or more of the following materials: chromium, erbium, neodymium, praseodymium, titanium, ytterbium. For example, information is or will be written into the recording layer by means of a laser, preferably a YAG laser, more preferably an Nd:YAG laser (short for neodymium-doped yttrium aluminum garnet laser). The emitted wavelength of the YAG laser is preferably 1064 nm. The cover layer is preferably transparent to the wavelength of 1064 nm and / or that of the laser.The recording layer can therefore be processed, particularly through the cover layer, using a laser to inscribe information into the recording layer. The security element preferably overlaps such inscribed information, thus increasing the forgery security of the laminate, especially the security document.

[0028] It is possible for the adhesive layer to adhere to the cover layer or the recording layer via a material-to-material bond, in particular an adhesive bond. The release layer preferably adheres to the cover layer or the recording layer via a welded bond, in particular without an intermediate adhesive bond. In particular, the cover layer and the recording layer, and preferably also the release layer, form a monolithic body. The connection of the security element via the adhesive layer and via the release layer is therefore preferably based on different physical principles, which make detachment of the security element on the release layer side preferably very complex or even impossible. The adhesive layer preferably adheres to the reflection layer via a material-to-material bond and / or to the replication layer via a material-to-material bond.The reflection layer adheres to the replication layer in particular via a material bond.

[0029] A materially bonded composite of recording and cover layers, for example in the form of polycarbonate layers, in particular made of almost 100% polycarbonate, which is advantageously achieved by welding during a lamination process, is considered to be ideally bonded and thus offers a counterfeiter few options for separating the individual layers without destroying them. For example, the layers cannot be separated simply by exerting a tensile force at an interface. However, the security element laminated into it acts as a foreign body in the structure, i.e., the adhesion to adjacent cover and recording layers, in particular to adjacent polycarbonate layers, is significantly reduced compared to the adhesion directly between the cover layer and recording layer.To extract the security element from the laminate, a counterfeiter could cut the polycarbonate layers before splitting them at the edge of the security element and then attempt to peel off one of the layers. This procedure was simulated by the tests below and can be made further difficult by a predetermined breaking point provided by the adhesive layer for cohesive failure and also preferably selected geometric and material parameters, for example by increasing the peel force. The peel force can be measured in particular as described below, preferably by means of a peel test on the laminate. The peel force is also referred to in particular as peel strength, peel force, detachment force or adhesion force. The peel force can in particular be measured by a peel test according to ISO / IEC 10373-1:2006(E); paragraph 5.3 and / or according to the peel test described below.

[0030] In the peel test, an optionally preconditioned laminate, preferably in the form of a card, is cut into 10 mm wide test strips.

[0031] For example, the layer or all layers on one side of the security element are removed, i.e., for example, the corresponding portion of the recording layer or the cover layer is removed, preferably with a length of 5 mm to 10 mm. For example, using a sharp knife, the layers above the security element, in particular a KINEGRAM®, are peeled off from the core, i.e., in particular, the cover layer is peeled off from the recording layer or the recording layer is peeled off from the cover layer. This peeling off is expediently only partial.

[0032] Subsequently, the peeled end, in particular of the cover layer, is preferably attached to the holder of a tensile testing machine using a fastening clamp or adhesive tape. A right angle is preferably created between the peeled layers attached to the tensile testing machine and the non-peeled layers. In particular, a right angle is created between the cover layer and the recording layer. Advantageously, the lower part of the laminate, in particular the recording layer, is optionally fixed to a stabilizing plate.

[0033] During the tensile test, the peeled film layer can preferably be guided over a roller. The peel strength is preferably recorded graphically and then evaluated, preferably omitting the first and last 5 mm of the measurement. The results are expressed, for example, in N / 10 mm.

[0034] It is also possible to take the measurement at locations without a security element, for example to measure the adhesive force between the cover layer and the recording layer.

[0035] It has proven particularly advantageous to reduce the adhesive layer thickness directly proportionally to the thickness of a stabilizing layer preferably arranged between the adhesive layer and the replication layer, in order to guarantee cohesive failure, in particular when the adhesive layer adheres to the recording layer.

[0036] It is advantageously possible that a peel force for detaching the cover layer from the security element is or will be provided in the laminate which is equal to or greater than 3.5 N / 10 mm strip width.

[0037] The adhesive layer preferably serves to bond a transfer layer bearing one or more security elements according to the invention to the substrate during application, i.e. in particular when the security element is applied to the cover layer or the recording layer as the substrate. This can be an adhesive layer that is activated by heat and pressure. Such an adhesive layer that is to be activated by heat and pressure can in particular have thermoplastic properties or can also be crosslinked by the action of heat, whereby reactivation by heat can be prevented. It is also possible for such an adhesive layer to be a hybrid layer comprising thermoplastic portions and crosslinking components. A heated stamp is typically used for activation, the shape of which defines the area to be transferred.

[0038] Alternatively, a transfer can be carried out using a so-called cold transfer. The adhesive layer is printed, preferably onto the transfer layer of a transfer film or onto the cover layer or the recording layer. The cover layer or the recording layer is then brought into contact with the transfer layer, and the adhesive layer is cured, in particular such that the security element is formed from the transfer layer and the printed adhesive layer. Curing occurs in particular using UV radiation. The adhesive layer can be composed of several different layers and, for example, contain one or more adhesion promoter layers, in particular to ensure the bonding of the adhesive layer to the reflective layer or to the optionally present stabilizing layer.

[0039] Advantageously, the adhesive force of the adhesive layer to its directly adjacent layer, consisting of a cover layer or recording layer, is higher than the cohesive force of the adhesive layer. Preferably, the adhesive force within the adhesive layer, in particular the cohesive force of the adhesive layer, is lower than the adhesive force between the security element and the recording layer, and also lower than the adhesive force between the security element and the cover layer.

[0040] It is particularly advantageous if the adhesive layer has the lowest yield strength, in particular the lowest upper yield strength, and / or the lowest modulus of elasticity of the layers of the security element, the recording layer, and / or the cover layer. Preferably, the lowest force from the cohesive and adhesive forces within the security element or within the laminate with the security element is the cohesive force of the adhesive layer.

[0041] It is also possible for the adhesive layer to have or consist of a ductile layer, in particular where a ductile layer is understood to be a layer with the highest elongation at break in the security element compared to the other layers of the security element.

[0042] This makes it possible for the adhesive layer to have or consist of a ductile layer, with this ductile layer being the layer that can be split by cohesive failure. Advantageously, the ductile layer, particularly compared to a brittle adhesive layer, promotes cohesive failure and makes adhesive failure more difficult, and in particular, increases the peel strength.

[0043] It is particularly possible for the laminate to be designed in such a way that during the peel test and / or an attempt to detach the cover layer and / or the recording layer from the laminate, a pure cohesive failure occurs or the adhesive layer detaches in one or more partial areas at an interface to a directly adjacent layer of cover layer or recording layer. The latter can be the case in particular with a partial adhesive failure. However, these one or more partial areas preferably have a smaller surface area than a remaining area of ​​the interface, which preferably shows no detachment of the adhesive layer and the adjacent layer. The remaining area of ​​the interface has, in particular, remnants of the adhesive layer, since a cohesive failure is present there.Preferably, the laminate is designed such that the one or more partial surfaces occupy such a small area that the peel force is at least 3.5 N / 10 mm, preferably measured using the peel test. For this purpose, for example, the thickness of the adhesive layer can be adjusted accordingly and / or the optionally present stabilizing layer can be used.

[0044] It is preferred that the remaining area covers at least 50%, at least 80%, preferably at least 90%, of the surface area of ​​the interface and / or the one or more partial areas cover less than 50%, preferably less than 20%, preferably less than 10%, of the surface area of ​​the interface.

[0045] In this case, the observation takes place in particular along a perpendicular to a plane spanned by the interface. Advantageously, this ensures a high overall peel force even in the case of irregularities in the laminate, which can lead to local tensile stress peaks and thus local adhesion failures. In an advantageous embodiment, the adhesive layer, in particular the ductile layer, comprises a material with a Young's modulus (E-modulus = elastic modulus) in a range from 20 MPa to 300 MPa, preferably from 50 MPa to 200 MPa, more preferably from 75 MPa to 150 MPa. The Young's modulus is determined in particular in accordance with DIN EN ISO 527-3:2003-07 ("Plastics - Determination of tensile properties - Part 3: Test conditions for films and sheets - Date of issue: 2003-07), preferably at room temperature (25°C).The tensile modulus of elasticity is determined on film test strips using a tensile testing machine, for example, a tensile testing machine from ZwickRoell GmbH & Co. KG, Ulm, Germany. The film strips are preferably 15 mm + / - 0.1 mm wide, and 100 mm + / - 0.5 mm long, or 50 mm + / - 0.5 mm long for film materials with particularly high elongation. The test speed is 10 mm / min + / - 1 mm / min for a film length of 100 mm, or 5 mm / min + / - 1 mm / min for a film length of 50 mm.

[0046] The adhesive layer is arranged, in particular, across the entire surface of the security element and is continuous. This prevents tension differences, which would otherwise promote adhesive failure, particularly when removing the cover layer.

[0047] The adhesive layer comprises in particular thermoplastics or crosslinking or crosslinked polymers, in particular polymethyl methacrylate and / or polybutyl methacrylate.

[0048] Crosslinking is understood in particular as a chemical reaction in which macromolecules, in particular polymers, are linked to form a three-dimensional network, preferably a polymerization.

[0049] The adhesive layer is preferably produced on the basis of the following materials, individually or in combination, selected from polymethyl methacrylate and polybutyl methacrylate. It is also possible for the adhesive layer to comprise one or more additives, individually or in combination, selected from fillers, such as TiO2, BaSO4, or silica. The adhesive layer preferably has a glass transition temperature Tg in a range from 20°C to 50°C. Furthermore, a melting temperature Tm of the adhesive layer in a range from 40°C to 150°C is preferred. The molar mass of the adhesive layer is in particular in a range from 100 kg / mol to 350 kg / mol.

[0050] The adhesive layer has a thickness in particular in a range from 0.2 pm to 20 pm, preferably in a range from 0.2 pm to 10 pm. It is particularly preferred if the adhesive layer has a thickness in a range from 3.5 pm to 20 pm, more preferably from 3.5 pm to 10 pm, and / or in a range from 4 pm to 20 pm, more preferably from 4 pm to 10 pm, and / or in a range from 6 pm to 20 pm, in particular from 6 pm to 10 pm.

[0051] The adhesive layer is preferably transparent or semi-transparent. The adhesive layer may have a milky-white appearance. A semi-transparent and / or milky-white adhesive layer advantageously makes it particularly easy to visually detect cohesive failure in the adhesive layer. For this purpose, TiC, for example, can be included in the adhesive layer.

[0052] It is possible that the adhesive layer may have a slightly rough surface prior to application. The surface roughness is preferably between 0.4 pm and 2.0 pm, in particular between 0.6 pm and 1.0 pm. The necessary measurements are preferably carried out using a microscope, in particular a Keyence VK-X3000, and the necessary software, possibly VK Analyzer.

[0053] The release layer has, in particular, a thickness in a range from 0.2 pm to 10 pm, preferably in a range from 0.2 pm to 5 pm. The release layer comprises or consists of materials selected individually or in combination from: thermoplastics, thermoplastic elastomers, crosslinked polymers, UV-crosslinked polymers, isocyanates, additives, catalysts, release agents. UV-crosslinkable is to be understood in particular as UV-curable, and UV-crosslinked is to be understood in particular as UV-cured. The release layer is expediently transparent. It is preferred that the release layer has a smooth surface before the security element is laminated in. Before lamination, the release layer has, in particular, a low surface roughness, preferably an R3z value of less than 2 pm, more preferably less than 0.5 pm.

[0054] It has been shown that during lamination, a stronger adhesive force can be achieved between the release layer and the adjacent cover layer or recording layer than the adhesive force within the adhesive layer, and in particular, the cohesive force of the adhesive layer. Furthermore, it is possible for the adhesive force of the release layer to the adjacent cover layer or recording layer to be greater than the adhesive force between the adhesive layer and the cover layer or recording layer adjacent to the adhesive layer. Thus, the separation behavior of the laminate can be advantageously and specifically adjusted via the adhesive layer.

[0055] The reflective layer expediently consists of a material with a refractive index that differs from the refractive index of the replication layer by at least 0.2. The reflective layer preferably comprises or consists of a metal layer or a high-refractive index layer (=HRI layer), or combinations thereof. Typical materials of an HRI layer are, for example, ZnS and / or TiO2. The high-refractive index layer can comprise or consist of materials selected individually or in combination from SiOx, MgO, TiOx, Al2O3, ZnO, ZnS. The variable x is preferably in the range from 0 to 3, i.e. x=0, 1, 2, 3. The reflective layer can comprise or consist of the following metals, individually or in combination: chromium, aluminum, gold, copper, tin, indium, silver, and an alloy of one or more of the above metals.It is also possible for the reflective layer to preferably comprise one or more metal oxides selected from aluminum oxide, chromium oxide, silicon oxide, indium tin oxide, titanium oxide, and combinations thereof. The reflective layer preferably has a refractive index for wavelengths in a range from 420 nm to 780 nm of more than 1.9. The layer thickness of the reflective layer is in particular in a range from 40 nm to 200 nm, preferably in a range from 40 nm to 100 nm. The layer thickness preferably refers to one layer of the reflective layer. In the case of a multilayer reflective layer, in particular one or more of the layers can have the specified layer thickness.

[0056] Typically, the reflective layer is vacuum-deposited or sputtered. The reflective layer can also be applied or configured only partially and / or have different thicknesses in certain areas.

[0057] The security element preferably has a stabilizing layer on the side of the adhesive layer facing the replication layer and the reflection layer. The stabilizing layer particularly ensures that the laminate can be formed in such a way that cohesive failure can be provided in the adhesive layer or that cohesive failure becomes more likely upon removal of the cover layer, for example, in the case of a relatively thin adhesive layer that would still be prone to adhesive failure on its own. Advantageously, the stabilizing layer simultaneously fulfills a protective function during lamination by largely preserving the brilliance of the optical effects during lamination and preventing warping of the security element, in particular of the transfer layer with the security element.

[0058] The stabilizing layer preferably has a thickness of 0.5 pm to 20 pm, more preferably in the range 1 pm to 10 pm. It is particularly possible for the stabilizing layer, preferably when the adhesive layer adheres to the recording layer, to have a thickness of 1 pm to 10 pm and / or together with the thickness of the adhesive layer, to have at least 1 pm and / or together with the thickness of the adhesive layer, to have a maximum of 40 pm and / or to have a thickness of 0.1 times to 20 times the thickness of the adhesive layer. In particular, it has proven advantageous for the ratio of the thickness of the adhesive layer to the thickness of the stabilizing layer to be in a range from 0.4 to 4. It has proven advantageous for the stabilizing layer to have or consist of a layer made of a material with an E-modulus in a range from 500 to 1500 MPa.

[0059] The stabilizing layer comprises or consists in particular of a material selected individually or in combination from: thermoplastics, thermoplastic elastomers, cross-linked polymers, UV-cross-linked polymers, isocyanates, additives, catalysts, and release agents. The stabilizing layer can be formed by a radiation-cross-linkable lacquer or a chemically reactive lacquer, such as an epoxy resin.

[0060] The stabilizing layer preferably exhibits brittle behavior. During a separation test or during a Young's modulus measurement on a tensile specimen of the laminate, elastic deformation of the stabilizing layer advantageously occurs.

[0061] The stabilizing layer is preferably transparent, especially clear. The stabilizing layer preferably has a smooth surface. The stabilizing layer can also consist of multiple layers and, for example, include an adhesion promoter layer for bonding to the reflective layer.

[0062] One or more further layers which fulfil further functions can be located between the release layer and the replication layer. For example, a protective layer can be provided which is arranged between the release layer and the replication layer. This fulfills in particular a stabilising mechanical effect against degradation when the security element is laminated between the recording layer and the cover layer, in particular wherein the recording layer and the cover layer comprise or consist of polycarbonate. For this purpose, such a protective layer is or will be preferably thermally stabilised, for example by crosslinking by means of radiation or by means of a chemical reaction. The protective layer preferably comprises or consists of materials selected individually or in combination from: thermoplastics, thermoplastic elastomers, crosslinked polymers, or UV-crosslinked polymers, isocyanates, additives, catalysts, release agents.

[0063] To laminate the security element, a laminating process is or will preferably be carried out, preferably by means of a roll laminator or a stroke press.

[0064] In a roll-fed laminator, the recording layer, the cover layer, and the security element positioned between these two layers can be introduced between at least two heated rollers. In a reciprocating press, the recording layer, the cover layer, and the security element positioned between these two layers can be introduced between heated plates, for example.

[0065] The lamination is or will preferably be carried out by means of a pressure exerted on the recording layer, the cover layer and / or the security element of 10 N / cm 2 up to 400 N / cm 2 , preferably 40 N / cm 2 up to 200 N / cm 2, carried out. It is possible that the lamination is or is carried out by means of a temperature of more than 150°C, preferably between 160°C and 210°C, which is applied to the recording layer, the cover layer and / or the security element by a heat source, in particular by one or more of the heated rollers or one or more of the heated plates. The lamination is or is preferably carried out by means of a contact time of the heat source with the recording layer and / or the cover layer in a range of 1 minute or more and 30 minutes or less. The contact of the heat source preferably takes place directly or indirectly via further layers with the recording layer and the cover layer. The above settings are preferably to be used for a recording layer and a cover layer consisting of or comprising polycarbonate.For other materials, such as polyvinyl chloride, different temperature and pressure settings may be used, tailored to the materials being processed. It is possible that the following steps, particularly in the specified order, may be performed before or for the preparation of the cover layer or recording layer provided with the security element:

[0066] - Providing a transfer film with a carrier layer and with a transfer layer, wherein the transfer layer has the security element and the release layer is arranged on the side of the security element facing the carrier layer.

[0067] - Applying the security element to the recording layer or to the cover layer.

[0068] A mechanically stable, i.e., in particular self-supporting, carrier film is expediently used as the carrier layer. Typically, the carrier layer comprises or consists of polyester, preferably polyethylene terephthalate (PET) or polyethylene naphthalate (PEN). The thickness of the carrier layer is preferably in a range from 5 to 150 μm, preferably 5 to 50 μm, more preferably 10 to 25 μm. The carrier layer is preferably transparent.

[0069] The application of the security element is preferably carried out by means of the following steps, in particular in the specified order:

[0070] - Applying the adhesive layer to the recording layer or to the cover layer

[0071] - Peeling off the carrier layer from the transfer layer so that the security element remains on the recording layer or the cover layer.

[0072] The transfer layer can be transferred completely or in sections, for example, using a pattern defined by an embossing die or an embossing roller. Alternatively, a partially printed adhesive, particularly in a patterned form, can effect the partial transfer of the transfer layer, so that the security element is formed by the printed adhesive and the partially transferred transfer layer. The adhesive layer of the security element then preferably comprises or consists of the printed adhesive layer.

[0073] During application, the release layer expediently ensures that the composite layer of the transfer layers can be removed from the carrier layer. In particular, the release layer can surprisingly ensure good adhesion to the adjacent cover layer or recording layer during lamination of the security element, especially if these comprise or consist of polycarbonate. The release layer thus fulfills a dual function, ensuring, on the one hand, improved release during production and, on the other hand, improved adhesion in the final product.

[0074] One or more wax layers can be arranged between the release layer and the carrier layer. In particular, one or more, preferably thin, wax layers can improve the separation of the transfer layer from the carrier. The thickness of each wax layer is preferably in the range from 1 nm to 50 nm. The one or more wax layers are preferably removed before lamination of the security element. This allows, in particular, a strong bond between the release layer and the recording layer or the cover layer to be achieved.

[0075] The application of the adhesive layer is preferably carried out by hot stamping. It is particularly possible for the hot stamping to be carried out at a temperature of 80°C to 300°C, from 100°C to 240°C, particularly preferably from 100°C to 180°C. The hot stamping is preferably carried out with an embossing pressure of 10 N / cm 2 up to 10000 N / cm 2 , preferably 100 N / cm2 up to 5000 N / cm 2 carried out. Preferably, the hot embossing is or will be carried out with an embossing time of 0.01 s to 2 s, more preferably 0.01 s to 1 s. The relief surface of the replication layer preferably forms optically active structures. Optically active structures are understood to mean, in particular, structures selected individually or in combination from: diffractive surface relief, holographic surface relief, first-order diffraction grating, zero-order diffraction structure, blazed grating, achromatic surface relief, surface relief in the form of a lens and / or a lenticular grid, an arrangement of micromirrors, microprisms, microlenses, microfacets, freeform surfaces, mirror surfaces, matt structures, in particular isotropic or anisotropic matt structures.

[0076] Furthermore, it is possible for the replication layer to comprise or consist of thermoplastics or crosslinked polymers, preferably UV-crosslinked polymers. The replication layer preferably has a smooth surface prior to replication. The thickness of the replication layer is in particular in a range from 0.2 μm to 20 μm, preferably in a range from 0.2 μm to 10 μm.

[0077] A relief surface is or will be molded into the replication layer by replication. The molding can be carried out thermoplastically, by structuring the surface using a tool that has the optically active structures as a correspondingly negatively molded relief, preferably under pressure and temperature. The replication layer can also be formed from a polymerizable or polymerized lacquer, preferably consisting of monomers and oligomers, which is or is polymerized after or during the introduction of the relief surface. This polymerization can take place using UV radiation or electron beams. The replication layer can also represent a hybrid form in that it is or will be thermoplastically deformed and then cured.The replication layer preferably comprises or consists of materials selected individually or in combination from: thermoplastics, crosslinked polymers, or UV-crosslinked polymers, isocyanates, additives, catalysts, and release agents. The invention is explained below using several exemplary embodiments with the aid of the accompanying drawings. In the following, the following are shown:

[0078] Fig. 1a, 1b, 1c and 1d schematically show a cross-section of a laminate,

[0079] Fig. 2a, 2b, 3a and 3b schematically show a process for producing a laminate,

[0080] Fig. 4a and 4b schematically show a transfer film and its production,

[0081] Fig. 5 schematically shows the structure of a peel test,

[0082] Fig. 6 schematic measurement curves of brittle and ductile material failure.

[0083] Fig. 1a and Fig. 1b each schematically show a laminate 1 in cross-section. The laminate 1 is preferably a security document.

[0084] The laminate 1 comprises a recording layer 11, a transparent cover layer 12, and a security element 20. The security element 20 is laminated between the recording layer 11 and the cover layer 12. The security element 20 has a release layer 21, an optional protective layer 22, a replication layer 23 with a relief surface arranged on its side facing away from the release layer 21, a reflection layer 24 arranged on the relief surface, and an adhesive layer 25.

[0085] The adhesive layer 25 forms a side of the security element 20 facing away from the release layer 21. The laminate 1 is designed such that the adhesive layer 25 of the security element 20 can be split by a tensile force exerted on the security element 20 by the recording layer 11 and the cover layer 12.

[0086] The adhesive layer 25 of the laminate 1 shown in Fig. 1a adheres to the recording layer 11, with the release layer 21 adhering to the cover layer 12. The adhesive layer 25 of the laminate 1 shown in Fig. 1b adheres to the cover layer 12, with the release layer 21 adhering to the recording layer 11. In the cross-section shown, the thickness of a layer is indicated in particular by the height, i.e. the dimensions in the vertical direction. A view of a plane or main surface spanned by the laminate or its layers corresponds, for example, to a view from above. The adhesive layer 25 of the laminate 1 and of the laminate obtainable by the method according to the invention can be split in itself in particular by a tensile force exerted by the recording layer 11 and the cover layer 12 on the security element 20.The presence of a splittable adhesive layer 25 or a predetermined breaking point defined by the adhesive layer can be determined in particular by the peel tests described below, based on the explanations for Fig. 5.

[0087] Not shown in Figs. 1a and 1b is the bond between the cover layer 12 and the recording layer 11. However, there is usually no gap provided between the cover layer 12 and the recording layer 11 in the laminate 1. The opposing surfaces of the cover layer 12 and the recording layer 11 are fused together, particularly in regions outside the security element 20, as is illustrated, for example, by Figs. 1c and 1d and as can be achieved in particular with the methods described here. In particular, the cover layer 12 and the recording layer 11 form a monolithic body. Laminated or laminating means that a material-to-material bond between the recording layer 11 and cover layer 12 is or will be produced, preferably by means of a lamination process, so that the security element 20 is completely enclosed by the two layers 11 and 12.The security element 20 is or will be laminated in particular by the recording layer 11 and the cover layer 12 being welded together, thereby preferably completely enclosing the security element 20, preferably when viewed perpendicular to a plane or main surface spanned by the laminate 1, i.e., in a view from above in Fig. 1a and Fig. 1b. The recording layer 11 preferably comprises further substances, such as, in particular, a dopant. The dopant can increase the energy absorption capacity of the recording layer 11. Materials for doping are, in particular, selected from one or more of the following materials: chromium, erbium, neodymium, praseodymium, titanium, ytterbium. For example, information is or will be written into the recording layer 11 using a laser, preferably a YAG laser, preferably an Nd:YAG laser (short for neodymium-doped yttrium aluminum garnet laser).The emitted wavelength of the YAG laser is preferably 1064 nm. The recording layer 11 can therefore be processed by a laser, in particular through the cover layer 12, in order to write information into the recording layer 11. The security element 20 preferably overlaps such written information and thus increases the forgery security of the laminate 1, in particular the security document.

[0088] In a preferred embodiment, the recording layer 11 and / or the cover layer 12 comprises or consists of polycarbonate. So-called composite laminates, in which the recording layer and / or the cover layer consist of different materials, for example PVC with a PET core, are also conceivable. It is particularly advantageous for the recording layer 11 and the cover layer 12 to comprise or consist of polycarbonate and to be bonded to one another, in particular welded together, by means of lamination. This allows a particularly stable bond to be achieved during lamination. A bonded composite of polycarbonate layers, in particular made of almost 100% polycarbonate, which is advantageously achieved by welding together in a lamination process, cannot be separated by a counterfeiter or can only be separated with great difficulty.A detachment attempt, which takes advantage in particular of the reduced adhesion by the security element 20, was simulated by the tests below, in particular as described in Fig. 5, and can be made more difficult by a cohesive failure and correspondingly selected geometry and material parameters, for example by an increase in the peel force.

[0089] In the example of a laminate 1 described with reference to Fig. 1a, the following layer thicknesses can be realized, for example. The cover layer 12 in this example preferably has a layer thickness of 50 pm to 150 pm. The recording layer 11 in this example preferably has a thickness of 50 pm to 150 pm. The adhesive layer 25 in this example preferably has a thickness of 2 pm to 10 pm. The reflection layer 24 in this example preferably has a thickness of 40 nm to 100 nm. The replication layer 23 in this example preferably has a thickness of 0.2 pm to 10 pm. The optional protective layer 22 in this example preferably has a thickness of 1.0 pm to 10.0 pm.

[0090] In the example of a laminate 1 described with reference to Fig. 1b, the following layer thicknesses can be realized, for example. The cover layer 12 in this example preferably has a layer thickness of 50 pm to 150 pm. The recording layer 11 in this example preferably has a thickness of 50 pm to 150 pm. The adhesive layer 25 in this example preferably has a thickness of 2 pm to 10 pm. The reflection layer 24 in this example preferably has a thickness of 40 nm to 100 nm. The replication layer 23 in this example preferably has a thickness of 0.2 pm to 10 pm. The optional protective layer 22 in this example preferably has a thickness of 0.1 pm to 10 pm.

[0091] The adhesive layer 25 adheres via an adhesive bond to the recording layer 11 shown in Fig. 1a or to the cover layer 12 shown in Fig. 1b. The release layer preferably adheres via a welded bond to the cover layer 12 shown in Fig. 1a or to the recording layer 11 shown in Fig. 1b. The adhesive layer preferably adheres via a material-to-material bond to the reflective layer and / or via a material-to-material bond to the replication layer 23. The reflective layer adheres in particular via a material-to-material bond to the replication layer 23. Advantageously, the adhesive force of the adhesive layer 25 to its directly adjacent layer of cover layer 12 or recording layer 11 is higher than the cohesive force of the adhesive layer 25. Preferably, the adhesive force within the adhesive layer 25, in particular the cohesive force of the adhesive layer 25, is lower than the adhesive force between the security element 20 and the.

[0092] Recording layer 11 and also less than an adhesive force between the security element 20 and the cover layer 12.

[0093] It is particularly advantageous if the adhesive layer 25 has the lowest yield strength, in particular the lowest upper yield strength, and / or the lowest modulus of elasticity of the layers of the security element 20, the recording layer 11, and / or the cover layer 12. Preferably, the lowest force from the cohesive and adhesive forces within the security element 20 or within the laminate 1 with the security element 20 is the cohesive force of the adhesive layer 25. As can be seen in Figs. 1a and 1b, the adhesive layer 25 is arranged, in particular, over the entire surface and continuously within the security element 20.

[0094] The adhesive layer 25 preferably serves to bond a transfer layer of a transfer film, as described for example in relation to FIGS. 4a and 4b, which carries one or more security elements 20 according to the invention, to the substrate during application, i.e. in particular when the security element 20 is applied to the cover layer 12 and / or the recording layer 11 as the substrate. This can be an adhesive layer 25 which is activated by means of heat and pressure. For this purpose, a heated stamp is typically used, the shape of which defines the area to be transferred. Alternatively, a transfer can be carried out by means of a so-called cold transfer. In this case, a printing layer made of an adhesive, which forms the adhesive layer 25 in the laminate 1 or is encompassed by the adhesive layer 25, is preferably printed onto the transfer layer of a transfer film, onto the cover layer 12 or onto the recording layer 11.Then, preferably, the cover layer 12 or the recording layer 11 is brought into contact with the transfer layer, and the printed adhesive layer is cured, in particular such that the security element 20 is formed from the transfer layer and the printed adhesive layer. The adhesive layer 25 can in turn be composed of several different layers and, for example, contain one or more adhesion promoter layers, preferably in addition to the ductile layer, to ensure the bonding of the adhesive layer 25 to the reflective layer 24 or to the optionally present stabilizing layer.

[0095] It is also possible for the adhesive layer 25 to have or consist of a ductile layer, in particular wherein a ductile layer is understood to be a layer with the highest elongation at break in the security element compared to the other layers of the security element.

[0096] This makes it possible for the adhesive layer 25 to have or consist of a ductile layer, wherein the ductile layer can be split by cohesive failure. Advantageously, the ductile layer promotes cohesive failure and impedes adhesive failure, particularly compared to a brittle adhesive layer. This can increase the peel force.

[0097] In an advantageous embodiment, the adhesive layer 25, in particular the ductile layer, comprises a material having an E-modulus in a range from 20 MPa to 300 MPa, preferably from 50 MPa to 200 MPa, preferably from 75 MPa to 150 MPa. The Young's modulus is determined in accordance with DIN EN ISO 527-3:2003-07 ("Plastics - Determination of tensile properties - Part 3: Test conditions for films and sheets - Date of issue: 2003-07), preferably at room temperature (25°C). The tensile modulus of elasticity is determined on film test strips using a tensile testing machine (e.g. a tensile testing machine from ZwickRoell GmbH & Co. KG, Ulm, Germany). The width of the film strips is preferably 15 mm + / - 0.1 mm, and the length of the film strips is preferably 100 mm + / - 0.5 mm or 50 mm + / - 0.5 mm for film materials with particularly high elongation.The test speed for a film length of 100 mm is 10 mm / min + / - 1 mm / min, or the test speed for a film length of 50 mm is 5 mm / min + / - 1 mm / min. The adhesive layer 25 is preferably made from polymethyl methacrylate. It is also possible for the adhesive layer 25 to comprise one or more additives selected individually or in combination from fillers, such as TiO2, BaSCk, or silica.

[0098] The adhesive layer 25, in particular the ductile layer, may be milky white.

[0099] The adhesive layer 25, in particular the ductile layer, has in particular a thickness in a range from 0.2 pm to 20 pm, preferably in a range from 0.2 pm to 10 pm. It is particularly preferred if the adhesive layer has a thickness in a range from 3.5 pm to 20 pm, more preferably from 3.5 pm to 10 pm, and / or in a range from 4 pm to 20 pm, preferably from 4 pm to 10 pm, and / or in a range from 6 pm to 20 pm, in particular from 6 pm to 10 pm. The adhesive layer preferably has a glass transition temperature Tg in a range from 20°C to 50°C. Furthermore, a melting temperature Tm of the adhesive layer in a range from 40°C to 150°C is preferred. The molar mass of the adhesive layer is in particular in a range from 100 kg / mol to 350 kg / mol.

[0100] It is possible for the adhesive layer 25 to have a slightly rough surface prior to application to the cover layer 12 or the recording layer 11. The surface roughness is preferably between 0.4 pm and 2.0 pm, in particular between 0.6 pm and 1.0 pm. The necessary measurements are preferably performed using a microscope, possibly a Keyence VK-X3000, and the necessary software, possibly VK Analyzer.

[0101] The release layer 21 has, in particular, a thickness in a range from 0.2 pm to 10 pm, preferably in a range from 0.2 pm to 5 pm, here, for example, 4 pm. It is possible for the release layer 21 to comprise or consist of thermoplastics, thermoplastic elastomers, or crosslinked polymers, preferably UV-crosslinked polymers. The release layer 21 comprises or consists of materials selected individually or in combination from: thermoplastics, thermoplastic elastomers, crosslinked polymers, or UV-crosslinked polymers, isocyanates, additives, catalysts, release agents. The release layer 21 is expediently transparent. It is preferred that the release layer 21 has a low surface roughness before lamination, in particular an R3z value of less than 2 pm, preferably less than 0.5 pm.

[0102] Here, for example, a reflective layer 24 made of aluminum with a layer thickness of 50 nm is used. It is also possible for the reflective layer 24 to comprise or consist of a metal layer or a high-refractive index layer (=HRI layer) or combinations thereof. Typical materials of an HRI layer are, for example, ZnS and / or TiO2. The high-refractive index layer can comprise or consist of materials selected individually or in combination from SiOx, MgO, TiOx, Al2O3, ZnO, ZnS. The variable x is preferably in the range from 0 to 3, i.e. x=0, 1, 2, 3. The reflective layer 24 can comprise or consist of the following metals individually or in combination: chromium, aluminum, gold, copper, tin, indium, silver and an alloy of one or more of the above metals.It is also possible for the reflective layer 24 to preferably comprise one or more metal oxides selected from aluminum oxide, chromium oxide, silicon oxide, indium tin oxide, titanium oxide, and combinations thereof. The reflective layer 24 preferably has a refractive index for wavelengths in a range from 420 nm to 780 nm of more than 1.9. The layer thickness of the reflective layer 24 can be in a range from 40 nm to 200 nm, preferably in a range from 40 nm to 100 nm, and here is, for example, 50 nm. The reflective layer can also be configured only partially and / or have different thicknesses in subregions.

[0103] Preferably, the security element 20 has a stabilization layer 26 on the side of the adhesive layer 25 facing the replication layer 23 and the reflection layer 24.

[0104] The stabilizing layer 26 advantageously fulfills its protective function during lamination by serving to ensure the brilliance of the optical effects during lamination and to prevent warping of the security element 20, in particular of the transfer layer with the security element 20. At the same time, the stabilizing layer 26 can, in particular, ensure that the laminate 1 can be formed such that a predetermined breaking point can be provided by a cohesive failure of the adhesive layer 25 or that a cohesive failure becomes more likely upon removal of the cover layer 12, for example, with a relatively thin adhesive layer 25, which alone would still be prone to adhesive failure.

[0105] The stabilizing layer 26 preferably has a thickness of 0.5 μm to 20 μm, preferably in the range of 1 μm to 10 μm. It is particularly possible for the stabilizing layer 26, preferably when the adhesive layer 25 adheres to the recording layer 11, to have a thickness of 1 μm to 10 μm and / or, together with the thickness of the adhesive layer 25, to have at least 1 μm and / or to have a thickness of 0.1 to 20 times the thickness of the adhesive layer 25.

[0106] It has proven advantageous that the stabilizing layer 26 comprises or consists of a layer made of a material with an E-modulus in a range of 500 to 1500 MPa.

[0107] The stabilizing layer 26 comprises or consists in particular of a material selected individually or in combination from thermoplastics, thermoplastic elastomers, or crosslinked polymers, or UV-crosslinked polymers, isocyanates, additives, catalysts, and release agents. The stabilizing layer 26 can be formed by a radiation-crosslinkable lacquer or by a chemically reactive lacquer, such as an epoxy resin.

[0108] Preferably, the stabilizing layer 26 has a brittle behavior.

[0109] The stabilizing layer 26 is preferably transparent, in particular clear and transparent. The stabilizing layer 26 preferably has a smooth surface.

[0110] One or more further layers that fulfill further functions can be located between the release layer 21 and the replication layer 23. For example, an optional protective layer 22 can be provided, which is arranged between the release layer 21 and the replication layer 23. This fulfills, in particular, a stabilizing mechanical effect against degradation during lamination of the security element 20, preferably in the recording layer 11 and the cover layer 12 made of polycarbonate. For this purpose, such a protective layer 22 is or will preferably be thermally stabilized, for example by crosslinking by means of radiation or by means of a chemical reaction. The protective layer 22 is formed here, for example, from thermoplastics and / or thermoplastic elastomers and / or crosslinked polymers, preferably UV-crosslinked polymers, isocyanates, additives, catalysts, and release agents.

[0111] It is further possible that the protective layer is transparent, in particular highly transparent and / or that the surface roughness of the protective layer is low, for example smooth, in particular that an R3z value of the protective layer of less than 2 pm, preferably less than 0.5 pm, is provided.

[0112] The relief surface of the replication layer 23 preferably forms optically active structures. A relief surface is or will be molded into the replication layer 23 by replication. The molding can be carried out thermoplastically by structuring the surface under pressure and temperature using a tool that has the optically active structures as a relief. The replication layer 23 can also be formed from a polymerizable or polymerized lacquer, preferably consisting of monomers and oligomers, which is or is polymerized after or during the introduction of the relief. This polymerization can take place by means of UV radiation or electron beams. The replication layer 23 can also represent a hybrid form in that it is thermoplastically deformable and can then be cured.A corresponding relief surface is or will be molded into the replication layer 23, in particular by means of a replication tool using thermal replication and / or UV replication. The surface relief can also be introduced by means of a laser. The replication layer 23 can also be a photosensitive layer into which the relief surface is introduced by exposure. The replication layer 23 is exposed to a pattern of varying light intensity and then, depending on the type of photosensitivity, the exposed or unexposed areas of the replication layer 23 are washed away or removed, in particular by means of solvents.

[0113] The replication layer 23 preferably has a smooth surface prior to replication. The material for the replication layer 23 includes, in particular, thermoplastics, cross-linked polymers, preferably UV-cross-linked polymers, or consists thereof. UV-cross-linked polymers are cured, in particular, by UV irradiation with wavelengths in a range from 100 nm to 400 nm. The replication layer 23 preferably includes or consists of materials selected individually or in combination from: polyester, polyurethane, polyacrylate, ethylene-vinyl acetate copolymer resins, polymethyl methacrylate, epoxy resins, cellulose-based resins.

[0114] Preferably, the replication layer 23 is not softened during the lamination of the security element. In particular, the softening temperature of the replication layer 23 is above the lamination temperature of the lamination. This makes it possible for the replication layer 23, and in particular the structures molded into the replication layer 23, to remain stable during lamination. For example, the brilliance of the decorative layer is retained, for example, by preserving a relief surface molded therein, which in particular ensures a high level of security against counterfeiting.

[0115] As a relief surface, one of the following relief surfaces or a combination of two or more of the following relief surfaces is preferably provided: diffractive surface relief, holographic surface relief, first-order diffraction grating, zero-order diffraction structure, blaze grating, achromatic surface relief, surface relief in the form of a lens and / or a lens grid, an arrangement of micromirrors, microprisms, microlenses, microfacets, free-form surface, mirror surface, matt structure, in particular isotropic or anisotropic matt structure.

[0116] The replication layer 23 preferably has different subregions in which different relief surfaces are molded, which differ in particular in one or more relief parameters and / or consist of different ones of the above-mentioned relief surfaces. Several of the above-mentioned relief surfaces can also overlap.

[0117] The thickness of the replication layer 23 is, for example, 8 pm and can preferably be in a range from 0.2 pm to 20 pm, preferably in a range from 0.2 pm to 10 pm.

[0118] Preferably, the surface roughness of the replication layer prior to replication is very low, for example, smooth. In particular, the surface of the replication layer has an R3z value of less than 2 pm, preferably less than 0.5 pm.

[0119] Figs. 2a, 2b, 3a, and 3b show a method for producing a laminate 1, which is, in particular, a security document. This method can be used, for example, to produce a laminate as described for one of Figs. 1a to 1d and, in particular, for the described experiments.

[0120] The procedure involves the following steps, for example in the order given:

[0121] - Providing a recording layer 11;

[0122] - Providing a transparent cover layer 12;

[0123] - Providing a security element 20.

[0124] The security element has a release layer 21, a replication layer

[0125] 23 with a relief surface arranged on its side facing away from the release layer 21, a reflection layer 24 arranged on the relief surface and an adhesive layer 25 which forms a side of the security element 20 facing away from the release layer 21.

[0126] The security element 20 is or will be applied to the cover layer 12, as shown in Fig. 2a and Fig. 2b, or attached to the recording layer 11, as shown in Fig. 3a and Fig. 3b. The security element 20 then adheres, in particular, to the cover layer 12 or to the recording layer 11 via the adhesive layer 25.

[0127] Depending on which of the two layers 11 and 12 the security element 20 is or is applied to, the other layer can also be provided afterward. The recording layer 11 and the cover layer 12 are then preferably arranged such that the security element 20 is located between these two layers.

[0128] Then, the security element 20 is laminated between the recording layer 11 and the cover layer 12. If the steps shown in Figs. 2a and 2b were performed beforehand, the adhesive layer 25 adheres to the cover layer 12, and the release layer 21 adheres to the recording layer 11. If the steps shown in Figs. 3a and 3b were performed beforehand, the adhesive layer 25 adheres to the recording layer 11, and the release layer 21 adheres to the cover layer 12. The two alternatives could optionally also be combined by using multiple security elements.

[0129] The adhesive layer 25 of the security element 20 is designed such that it can be split by a tensile force exerted on the security element 20 by the recording layer 11 and the cover layer 12.

[0130] With regard to specific embodiments of the security element 20, reference is also made in particular to the described embodiments of the security element of the laminate according to the invention. To laminate the security element 20, a lamination process is or will be carried out, preferably using a roller laminator or a reciprocating press.

[0131] In a roll-fed laminator, the recording layer 11, the cover layer 12, and the security element 20 arranged between these two layers can be introduced, for example, between at least two heated rollers. In a reciprocating press, the recording layer 11, the cover layer 12, and the security element 20 arranged between these two layers can be introduced, for example, between heated plates.

[0132] The lamination is or will preferably be carried out by means of a pressure exerted on the recording layer 11, the cover layer 12 and / or the security element 20 of 10 N / cm 2 up to 400 N / cm 2 , preferably 40 N / cm 2 up to 200 N / cm 2, carried out. It is possible that the lamination is or is carried out by means of a temperature of more than 150°C, preferably between 160°C and 210°C, which is applied to the recording layer 11, the cover layer 12 and / or the security element 20 by a heat source, in particular by one or more of the heated rollers or one or more of the heated plates. The lamination is or is preferably carried out by means of a contact time of the heat source with the recording layer 11 and / or the cover layer 12 in a range of 1 minute or more and 30 minutes or less. The contact of the heat source preferably takes place directly or indirectly via further layers with the recording layer 11 and the cover layer 12. The above settings are preferably to be used for a recording layer 11 and a cover layer 12 consisting of or comprising polycarbonate.For other materials, such as polyvinyl chloride, different temperature and pressure settings can be used, tailored to the materials to be processed.

[0133] Fig. 4a shows a transfer film and its production. Fig. 4b shows another embodiment of a transfer film and its production. Such a transfer film can be used to attach the security element 20 to the cover layer 12 or the recording layer 11.

[0134] It is particularly possible that before or for providing the security element 20, as described for Figs. 2a, 2b, 3a and 3b, the cover layer 12 or recording layer 11 provided with the security element 20, the following steps are carried out, in particular in the specified order:

[0135] - Providing a transfer film as described in Fig. 4a or Fig. 4b with a carrier layer 31 and with a transfer layer, wherein the transfer layer has the security element 20 and the release layer 21 is arranged on the side of the security element 20 facing the carrier layer 31.

[0136] - Applying the security element 20 to the recording layer 11 or to the cover layer 12.

[0137] A mechanically stable, i.e., in particular self-supporting, carrier film 31 is expediently used as the carrier layer 31. Typically, the carrier layer comprises or consists of polyester, preferably polyethylene terephthalate (PET for short), or polyethylene naphthalate (PEN for short). The thickness of the carrier layer is preferably in a range of 5 to 150 μm, preferably 5 to 50 μm, more preferably 10 to 25 μm. The carrier layer is preferably transparent.

[0138] The application of the security element 20 is carried out, for example, by means of the following steps, in particular in the specified order:

[0139] - Applying the adhesive layer 25 to the recording layer 11 or to the

[0140] Cover layer 12 - Peeling off the carrier layer 31 from the transfer layer so that the security element 20 remains on the recording layer 11 or the cover layer 12.

[0141] The transfer layer can be transferred completely or in sections, for example, using a pattern defined by an embossing die or an embossing roller. Alternatively, a partially printed adhesive, particularly in a patterned form, can effect the partially transferred transfer layer, so that the security element is formed by the printed adhesive and the partially transferred transfer layer, for example, without the adhesive layer or with the adhesive layer, preferably as an adhesion promoter layer, which is supplemented by the printed adhesive layer. The adhesive layer 25 of the security element 20 then preferably comprises or consists of the printed adhesive layer.

[0142] The application of the adhesive layer 25 to the recording layer 11 or to the cover layer 12 is or will preferably be carried out by hot stamping. It is particularly possible for the hot stamping to be carried out at a temperature of 80°C to 300°C, from 100°C to 240°C, particularly preferably from 100°C to 180°C. The hot stamping is or will preferably be carried out with an embossing pressure of 10 N / cm 2 up to 10000 N / cm 2 , preferably 100 N / cm 2 up to 5000 N / cm 2 Preferably, the hot stamping is carried out with a stamping time of 0.01 s to 2 s, preferably 0.01 s to 1 s.

[0143] As shown in Fig. 4a, a transfer film can be produced by successively applying the optional wax layer 32, the release layer 21, the optional protective layer 22 and the replication layer 23 to the carrier layer 31.

[0144] During application, the release layer 21 expediently ensures that the layer composite of the transfer layers can be removed from the carrier layer 31. During lamination into the laminate 1, this layer also ensures in particular that good adhesion is achieved with the adjacent cover layer 12 or recording layer 11, in particular where these comprise or consist of polycarbonate. One or more wax layers, such as the optional wax layer 32 shown in Fig. 4a and Fig. 4b, can be arranged between the release layer 21 and the carrier layer 31. In particular, the separation of the transfer layer from the carrier can be improved by one or more, preferably thin, wax layers. The thickness of a wax layer is preferably in a range from 1 nm to 50 nm. The wax layer 32 is preferably removed before the security element is laminated in.In particular, this makes it possible to achieve a strong bond between the release layer and the recording layer or the cover layer.

[0145] After the replication layer 23 has been applied, a relief surface can be molded into the replication layer 23 by replication, as already described above. A reflective layer 24 can then be applied to the relief surface, in particular over the entire surface or also partially or in regions, e.g. in the form of a pattern. For this purpose, the reflective layer is vapor-deposited or sputtered in a vacuum, for example. As Fig. 4b shows, the optional stabilizing layer 26 or, as Fig. 4a shows, the adhesive layer 25 can then preferably be applied directly to the reflective layer 24, and in particular when the reflective layer 24 is applied over a partial surface, also to the replication layer 23. As shown in Fig.4b, the optionally present stabilization layer 26 can additionally be applied between the adhesive layer 25 and the reflection layer 24, and in particular between the adhesive layer 25 and the replication layer 23, before in this case the adhesive layer 25 is then applied to the stabilization layer 26.

[0146] The adhesive layer 25 can also be constructed from multiple layers. For example, the adhesive layer 25 can contain one or more adhesion promoter layers, particularly in addition to the ductile layer, to ensure the bonding of the adhesive layer 25 to the reflective layer 24 or to the optionally present stabilizing layer 26. The layer of the adhesive layer 25 adhering to the cover layer 12 or recording layer 11 in the laminate 1 can, in particular, be applied as a hot-melt adhesive layer to the transfer layer or as a cold-melt adhesive layer in a later step to the transfer layer and any existing layers of the adhesive layer 25, or to the recording layer 11 or the cover layer 12.

[0147] Fig. 5 shows a setup for a peel test as described above, in particular for a test according to ISO / IEC 10373-1:2006(E); paragraph 5.3.

[0148] In the peel test, an optionally preconditioned card is cut into 10 mm wide test strips. For example, Fig. 5 shows a schematic cross-section of such a test strip of a laminate 1.

[0149] For example, all layers on one side of the security element 20 are removed, preferably over a length of 5 mm to 10 mm. The security element 20 is, in particular, a KINEGRAM®. For example, using a sharp knife, the cover layer 12 is peeled off the core, i.e., in particular, from the recording layer 11. Advantageously, the peeling off takes place only partially.

[0150] Subsequently, the peeled end is preferably attached to the holder of a tensile testing machine via a fastening clamp or by means of an adhesive tape 40. Preferably, a right angle is created between the peeled layers attached to the tensile testing machine, in particular the cover layer 12, and the non-peeled layers, in particular the corresponding part of the cover layer 12, the recording layer 11, and the security element 20. In particular, a right angle is created between the cover layer 12 and the recording layer 11. Conveniently, the lower part of the laminate 1 or the test strip thereof, in particular the recording layer 11, can be fixed to a stabilizing plate. During the tensile measurement, the detached film layer can be guided over a roller.The peel strength is preferably recorded graphically and then evaluated, preferably omitting the first and last 5 mm of the measurement. The results are expressed, for example, in N / 10 mm.

[0151] It is also possible to take the measurement at locations without a security element, for example to test the adhesion force between the cover layer and the recording layer.

[0152] The peel force test can advantageously be used to determine the influence of the various layers of the laminate 1 on the peel force. A dominant influence on the peel force is dissipation in the adhesive, whereby energy is converted into cohesive failure. If a structure delaminates due to adhesive failure, particularly at the interface between the adhesive layer 25 and the cover layer 12 or the recording layer 11, much lower peel forces result than in the case of cohesive failure. It is advantageously possible to set a peel force for detaching the cover layer 12 that is equal to or greater than 3.5 N / 10 mm strip width.

[0153] The measurement of the E-modulus can be carried out in particular as described below: The E-modulus can be determined according to DIN EN ISO 527- 3:2003-07 (“Plastics - Determination of tensile properties - Part 3:

[0154] Test conditions for films and sheets - Date of issue: 2003-07), preferably at room temperature (25°C). The tensile modulus of elasticity is determined on film test strips using a tensile testing machine (e.g. a tensile testing machine from ZwickRoell GmbH & Co. KG, Ulm, Germany). The width of the film strips is preferably 15 mm + / - 0.1 mm, the length of the film strips is preferably 100 mm + / - 0.5 mm or 50 mm + / - 0.5 mm for film materials with particularly high elongation. The test speed is 10 mm / min + / - 1 mm / min for a film length of 100 mm or the test speed is 5 mm / min + / - 1 mm / min for a film length of 50 mm. Fig. 6 shows an example of a comparison of the course of a ductile material failure 6 and the course of a brittle material failure 5 in a force-displacement diagram. The y-axis indicates the force F and the x-axis indicates the distance L of the force-distance diagram.Brittle material failure (5) is characterized by a very steep increase in the measured force, followed by a sudden drop after the material's ultimate tensile strength is reached. In ductile material failure (6), however, the increase in the measured curve is noticeably less steep, with the force remaining at an essentially constant level after the yield stress is reached. This material behavior is also particularly evident in the results of the peel tests. Dissipation in the area of ​​the fracture tip or crack tip during removal of the surface layer remains at the highest possible level, particularly in the case of cohesive failure, which is not the case with adhesive failure.

[0155] Exemplary experiments and comparative tests for verification are described below.

[0156] For verification, appropriate samples were produced. A hot stamping foil (B944059, manufactured by Leonhard Kurz Stiftung & Co. KG, Fürth, Germany), which had a thickness of 19 μm, served as the basis. The foil had the following structure: PET carrier, release layer, protective layer, and replication layer. A relief surface was molded into the replication layer, with a cylindrical metal plate pressed against the replication layer. The plate temperature was 180°C, and the pressure was 100 N / cm. 2 , the production speed was 20 m / min.

[0157] A reflective layer consisting of zinc sulfite (ZnS) with a thickness of 60 nm was then vacuum-deposited onto the relief surface. A polymethyl methacrylate-based adhesive was then applied using a gravure printing process, with the adhesive layer thickness being varied for the tests. The following layer thicknesses were determined after solvent removal: 1 pm, 4 pm, and 6 pm.

[0158] The security elements were then applied to a transparent polycarbonate cover layer (Makrofol ID 6-2, manufactured by Covestro AG, Leverkusen, Germany) with a thickness of 100 μm or a transparent polycarbonate recording layer (Makrofol ID 6-2 laserable, manufactured by Covestro AG) with a thickness of 100 μm. A hot stamping transfer machine was used, with an embossing temperature of 170°C and an embossing pressure of 250 N / cm 2and an embossing time of 0.5 s was used. Subsequently, cards were produced with a structure according to ISO / IEC 7810:2003(E), using white polycarbonate (Makrofol ID 6-4, manufactured by Covestro AG) with a thickness of 100 μm for the remaining card structure. For the samples of Experiment Series 1, the adhesive layer of the security element formed an adhesive bond with the cover layer; for the samples of Experiment Series 2, the adhesive layer of the security element formed a bond with the recording layer. For the necessary lamination process, a process temperature of 190°C and a pressure of 120 N / cm 2 and a pressing time of 15 minutes. Cards were then punched from the laminates.

[0159] The peel forces for the recording layer and the security element are shown in Experiment Series 1. The peel forces for the cover layer and the security element are shown in Experiment Series 2. The peel forces were determined by a peel test conducted according to ISO / IEC 10373-1:2006(E); paragraph 5.3 and / or the peel test described above.

[0160] The results of these measurements can be seen in Table 1.

[0161] Table 1

[0162] As can be seen in Table 1, the thickness of the adhesive in Experiment Series 1 influences the peel forces. These increase with increasing layer thickness. At a layer thickness of 1 μm, the peel force is 0.8 N / 10 mm sample width, caused by an adhesive failure between the adhesive layer of the security element and the recording layer. Increasing the layer thickness to 4 μm, however, leads to a cohesive failure, which in turn is reflected in an increase in the peel force to 2.6 N / 10 mm sample width. Increasing the layer thickness to 6 μm leads to an increase in the peel forces to 3.9 N / 10 mm sample width, which again results in a cohesive failure in the adhesive. This behavior can also be observed in Experiment Series 2. Again, the peel force is lowest at a layer thickness of 1 pm at 0.7 N / 10 mm, whereby an adhesion failure occurs between the adhesive layer and the cover layer.Increasing the layer thickness to 4 μm leads to cohesive failure in the adhesive, which is demonstrated by an increase in the peel force to 2.4 N / 10 mm sample width. Cohesive failure also occurred at a layer thickness of 6 μm, and the peel force increased to 4.9 N / 10 mm sample width. In particular, a self-detachable adhesive layer can be determined for various laminate structures. A comparison of Experiment Series 1 and Experiment Series 2 reveals the following points in particular:

[0163] - The bonding of the adhesive layer to the cover layer and to the recording layer can result in comparable peel forces.

[0164] - The two structures show an adhesive failure at an adhesive layer thickness of 1 pm, which can turn into a cohesive failure at a layer thickness of 4 pm.

[0165] - In both series of experiments, it is possible that a peel force of at least 3.5 N / 10 mm sample width can be achieved for the adhesive layer with a layer thickness of 6 pm.

[0166] - It is possible that the orientation of the security element in the layer structure of the security document has no influence on the fracture behavior in the adhesive layer of the security element in a peel test.

[0167] - To achieve a peel force of, for example, at least 3.5 N / 10 mm sample width, it is possible that the separation of the adhesive layer does not occur as a pure cohesive failure. A short-term change, such as a short-term decrease or increase in peel force, which is typically observed during the transition from cohesive failure to adhesive failure, may be neglected under defined conditions, particularly according to ISO / IEC 10373-1:2006(E), paragraph 5.3.

[0168] Fig. 7 schematically illustrates an example of crack propagation within a section of the laminate with the adhesive layer 25 and a layer 1112 directly adjacent to the adhesive layer 25. The layer 1112 is either the cover layer 11 or the recording layer 12. The adhesive layer 25 and the layer 1112 thus have, in particular, an interface formed between these layers or as a contact surface between the two layers. In Fig. 7, the cracks 51 and 52 are shown by the dashed lines. In a peel test and / or a detachment attempt of the cover layer 11 and / or the recording layer 12, in particular of the layer 1112 shown, one of the two cracks 51 and 52 can, for example, result.

[0169] As illustrated by the crack 51, there is in particular the possibility that during the cohesive failure the crack tip briefly encounters an interface between the adhesive layer 25 and the layer 1112 directly adjacent to the adhesive layer, but does not run along it as the separation progresses.

[0170] As is particularly illustrated by the crack 52, it is possible for the laminate to be designed such that the adhesive layer 25 detaches in one or more partial areas, which here lie in the region 520, at an interface to the directly adjacent layer 1112, which can be the case, for example, in the case of an adhesive failure. However, these one or more partial areas in the region 520 advantageously have a smaller surface area than a remaining area of ​​the interface, in particular so that the peel force is at least 3.5 N / 10 mm. The remaining area for the crack 52 is present here, for example, in the regions 521. The remaining area of ​​the interface in the region 521 has, in particular, remnants of the adhesive layer 25, since a cohesive failure occurred there. The surface area is particularly evident when viewed along a perpendicular to a plane spanned by the interface, for example in Fig.7 determined from bottom to top.

[0171] The remaining area, which is present for example in the region 521, covers in particular at least 50%, preferably at least 80%, preferably at least 90%, of the surface area of ​​the interface and / or the partial area, which is present for example in the region 520, covers less than 50%, preferably less than 20%, preferably less than 10% of the surface area of ​​the interface.

[0172] Advantageously, even in the case of irregularities in the laminate, which could lead to local tensile stress peaks during detachment of layer 1112 and thus to local adhesion failures, a cohesive failure can be predominantly induced, thus ensuring a high overall peel force. This is particularly possible even with a relatively thin adhesive layer with a layer thickness of at least 3.5 μm.

[0173] Advantageously, therefore, in a preferred embodiment, the adhesive layer has a thickness of at least or more than 3.5 pm, preferably at least or more than 4 pm, in particular at least or more than 6 pm.

[0174]

[0175] I Laminat

[0176] II Top layer

[0177] 12 recording layer

[0178] 1112 layer directly adjacent to the adhesive layer

[0179] 20 security element

[0180] 21 Release layer

[0181] 22 protective layer

[0182] 23 Replication layer

[0183] 24 reflective layer

[0184] 25 adhesive layers

[0185] 26 Stabilization layer

[0186] 31 Carrier film

[0187] 32 wax layer

[0188] 40 Clamp or adhesive tape r radius a angle x length of peeled layer

[0189] L Way

[0190] F Force

[0191] 5 brittle material failure

[0192] 6 ductile material failure

[0193] 51 , 52 cracks

[0194] 510 Area with partial area

[0195] 520 area with remaining area

Claims

Laminate (1), in particular a security document, comprising a recording layer (11), a transparent cover layer (12), and a security element (20) laminated between the recording layer (11) and the cover layer (12), wherein the security element (20) comprises a release layer (21), a replication layer (21) with a relief surface arranged on its side facing away from the release layer (21), a reflective layer (24) arranged on the relief surface, and an adhesive layer (25) which forms a side of the security element (20) facing away from the release layer (21), wherein a) the adhesive layer (25) adheres to the recording layer (11) and the release layer (21) adheres to the cover layer (12), or the adhesive layer (25) adheres to the cover layer (12) and the release layer (21) adheres to the recording layer (11), and b) the laminate (1) such that is designed,that the adhesive layer (25) of the security element (20) is capable of being split in on itself by a tensile force exerted on the security element (20) by the recording layer (11) and the cover layer (12). Laminate according to claim 1, characterized in that the adhesive layer (25) has the lowest yield strength, in particular upper, Yield strength, and has the lowest modulus of elasticity of the layers of the safety element.

3. Laminate according to claim 1 or 2, characterized in that the adhesive force of the adhesive layer (25) to its directly adjacent layer of cover layer (12) or recording layer (11) is higher than the cohesive force of the adhesive layer (25).

4. Laminate according to one of the preceding claims, characterized in that the peel force for removing the top layer (12), preferably from the safety element (20), is equal to or greater than 3.5 N / 10 mm strip width, in particular measured with a peel test, preferably with a peel angle (a) of 90°.

5. Laminate according to one of the preceding claims, characterized in that an adhesive force within the adhesive layer (25), in particular a cohesive force of the adhesive layer (25), - is less than an adhesive force between the security element (20) and the recording layer (11) (11) and also - is less than the adhesive force between the safety element (20) and the cover layer (12) (12).

6. Laminate according to one of the preceding claims, characterized in that a minimum force consisting of cohesive and adhesive forces within the safety element (20) or within the laminate (1) with the safety element is the cohesive force of the adhesive layer (25). Laminate according to any one of the preceding claims, characterized in that the adhesive layer (25) comprises or consists of a ductile layer, in particular wherein a ductile layer is understood to be a layer with the highest elongation at break in the safety element (20). Laminate according to any one of the preceding claims, characterized in that the adhesive layer (25), in particular the ductile layer, consists of a material having a modulus of elasticity in the range of 20 MPa to 300 MPa, preferably from 50 MPa to 200 MPa, more preferably from 75 MPa to 150 MPa. Laminate according to one of the preceding claims, characterized in that the adhesive layer (25) has a layer thickness in a range of 0.2 pm to 20 pm, preferably 0.2 pm to 10 pm and / or preferably in a range of 3.5 pm to 20 pm, more preferably from 3.5 pm to 10 pm, and / or in a range of 6 pm to 20 pm, in particular from 6 pm to 10 pm.Laminate according to any one of the preceding claims, characterized in that the adhesive layer (25) comprises thermoplastics or crosslinking or crosslinked polymers, in particular polymethyl methacrylate and / or polybutyl methacrylate. Laminate according to any one of the preceding claims, characterized in that the adhesive layer (25) is semitransparent and / or comprises one or more additives selected individually or in combination from fillers such as TiC, BaSCk, or silica. Laminate according to any one of the preceding claims, characterized in that the release layer (21) has a thickness in the range of 0.2 pm to 10 pm, preferably in the range of 0.2 pm to 5 pm. Laminate according to any one of the preceding claims, characterized in that the release layer (21) comprises or consists of thermoplastics, thermoplastic elastomers, cross-linked polymers, or UV-cross-linked polymers. Laminate according to any one of the preceding claims, characterized in that the relief surface of the replication layer (23) forms optically active structures. Laminate according to any one of the preceding claims, characterized in that the replication layer (23) comprises or consists of thermoplastics, cross-linked polymers, or UV-cross-linked polymers. Laminate according to any one of the preceding claims, characterized in that the thickness of the replication layer (23) is in the range of 0.2 pm to 20 pm, preferably in a range of 0.2 pm to 10 pm. Laminate according to one of the preceding claims, characterized in that the reflective layer (24) comprises or consists of a metal layer or a high-refractive index layer or combinations thereof. Laminate according to any one of the preceding claims, characterized in that the reflective layer (24) has a refractive index for wavelengths in the range of 420 nm to 780 nm of more than 1.

9. Laminate according to any one of the preceding claims, characterized in that the thickness of the reflective layer (24) is in the range of 40 nm to 200 nm, preferably in the range of 40 nm to 100 nm. Laminate according to any one of the preceding claims, characterized in that the safety element (20) has a stabilizing layer (26) on the side of the adhesive layer (25) facing the replication layer (23) and the reflective layer (24). Laminate according to any one of the preceding claims, characterized in that the stabilizing layer (26) has a thickness of 0.5 pm to 20 pm, preferably in the range of 1 pm to 10 pm.Laminate according to any one of the preceding claims, characterized in that, in particular when the adhesive layer (25) adheres to the recording layer (11), the ratio of the thickness of the adhesive layer (25) to the thickness of the stabilizing layer (26) is in the range of 0.4 to 4. Laminate according to any one of the preceding claims, characterized in that the stabilizing layer (26) comprises a layer or consists thereof. consists of a material with a modulus of elasticity in the range of 500 MPa to 1500 MPa.

24. Laminate according to one of the preceding claims, characterized in that the stabilizing layer (26) comprises or consists of thermoplastics, thermoplastic elastomers or cross-linked polymers, preferably UV-cross-linked polymers.

25. Laminate according to one of the preceding claims, characterized in that the recording layer (11) and the cover layer (12) comprise or consist of polycarbonate.

26. Laminate according to one of the preceding claims, characterized in that the layer thickness of the top layer (12) satisfies one or a combination of the following conditions: the layer thickness of the top layer (12) is in a range of 1.25 to 250 relative to the layer thickness of the adhesive layer (25); the sum of the thickness of the adhesive layer and the top layer is in a range of 26 pm to 270 pm; the top layer (12) has a layer thickness in a range of 25 pm to 250 pm.

27. Laminate according to one of the preceding claims, characterized in that the recording layer (11) has a thickness in a range of 25 pm to 250 pm.

28. Laminate according to one of the preceding claims, characterized in that that the adhesive layer (25) adheres to the cover layer (12) or the recording layer (11) by means of an adhesive bond. Laminate according to one of the preceding claims, characterized in that the release layer (21) adheres to the cover layer (12) or the recording layer (11) via a welded bond. Laminate according to one of the preceding claims, characterized in that the adhesive layer (25) adheres to the reflective layer (24) by means of a metallurgical bond and / or to the replication layer (23) by means of a metallurgical bond. Method for producing a laminate, in particular a security document, according to one of the preceding claims comprising the following steps, in particular in the specified order: - Providing a recording layer (11 ), - Provide a top layer (12), - Providing a security element (20), in particular according to one of the preceding claims, wherein the security element (20) comprises a release layer (21), a replication layer (23) with a relief surface arranged on its side facing away from the release layer (21), a reflective layer (24) arranged on the relief surface and an adhesive layer (25) which forms a side of the security element (20) facing away from the release layer (21), and the security element (20) is attached to the cover layer (12) or to the recording layer (11) with the adhesive layer (25); - Laminating the security element (20) between the recording layer (11) and the cover layer (12) such that a) the adhesive layer (25) adheres to the recording layer (11) and the release layer (21) adheres to the cover layer (12) or the adhesive layer (25) adheres to the cover layer (12) and the release layer (21) adheres to the recording layer (11) and b) the adhesive layer (25) of the security element (20) can be split into itself by a tensile force exerted on the security element (20) by the recording layer (11) and the cover layer (12).

32. Method according to claim 31, characterized in that a lamination process is carried out using a roller laminator or a lifting press to laminate the safety element (20).

33. Method according to claim 31 or 32, characterized in that the lamination is carried out by means of a pressure of 10 N / cm² exerted on the recording layer (11), the cover layer (12) and / or the security element (20). 2 up to 400 N / cm 2 , preferably 40 N / cm 2up to 200 N / cm 2 , has been done.

34. Method according to one of claims 31 to 33, characterized in that the lamination is carried out by means of a temperature acting on the recording layer (11), the cover layer (12) and / or the security element by a heat source, in particular by one or more of the heated rollers or one or more of the heated plates, of more than 150°C, preferably between 160°C and 210°C.

35. Method according to one of claims 31 to 34, characterized in that that the lamination process involves a contact time of the heat source with the recording layer (11) and / or the cover layer (12) in a range of 1 minute or more and 30 minutes or less.

36. Method according to one of claims 31 to 35, characterized in that the following steps are carried out in the specified order before or for providing the cover layer (12) or recording layer (11) provided with the security element (20): - Providing a transfer film with a carrier layer (31) and with a transfer layer, wherein the transfer layer has the safety element (20) and the release layer (21) is arranged on the side of the safety element (20) facing the carrier layer; - Applying the security element (20) to the recording layer (11) or to the cover layer (12).

37. Method according to one of claims 31 to 36, characterized in that the application of the safety element (20) is carried out by means of the following steps in the specified order: - Applying the adhesive layer to the recording layer (11) or to the cover layer (12); - Removing the carrier layer (31) from the transfer layer, so that the security element remains on the recording layer (11) or the cover layer (12).

38. Method according to one of claims 31 to 37, characterized in that the application of the adhesive layer (25) is carried out by means of hot stamping. A method according to any one of claims 31 to 38, characterized in that the hot stamping is carried out at a temperature of 80°C to 300°C, preferably from 100°C to 240°C, particularly preferably from 100°C to 180°C. A method according to any one of claims 31 to 39, characterized in that the hot stamping is carried out with a stamping pressure of 10 N / cm². 2 up to 10000 N / cm 2 preferably 100 N / cm 2 up to 5000 N / cm 2 is carried out. Method according to one of claims 31 to 40, characterized in that the hot stamping is carried out with a stamping time of 0.01 s to 2 s, preferably of 0.01 s to 1 s.

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