Security foil element with selection layer, production method, testing method and data carrier with security foil element

Abstract

The invention relates to a security foil element (12) for securing valuable objects (10), having a foil carrier (20) and a selection layer (24) applied to at least some portions of the foil carrier. The foil carrier (20) is formed from an extrudable plastic and in its volume is mixed with a machine-readable luminescent marker (22), which is used to emit luminescent radiation having a first wavelength and a second, different, wavelength (32, 34), each in the infrared spectral range. The selection layer (24) is designed to selectively spectrally inhibit the transmission of IR radiation, wherein the inhibiting effect on transmission differs for the first and second wavelengths (32, 34) by at least 10 percentage points.

Description

[0001] Foil security element with selection layer, manufacturing process, testing process and data carrier with foil security element

[0002] The invention relates to a film security element for protecting valuables, comprising a film carrier and a selection layer applied at least partially to the film carrier. The invention also relates to a data carrier with such a film security element, a method for producing such a film security element, and a method for testing such a film security element.

[0003] Data storage media, such as valuables or identification documents, as well as other valuable items such as branded goods, are often provided with security elements for security purposes. These elements allow verification of the authenticity of the data storage media and also serve as protection against unauthorized reproduction. To enable automatic authentication and, if necessary, further sensory detection and processing of the data storage media, the security elements are often machine-readable.

[0004] Machine-readable security elements are typically present in printed layers that can easily be scraped off or lost through abrasion during circulation. Also, the presence or absence of a machine-readable substance is typically used as a means of authentication. Such security elements can be relatively easily counterfeited, for example, by removing a genuine security element from a genuine data carrier and applying it in whole or in part to another, for example, fake, carrier substrate.

[0005] Based on this, the invention is based on the object of providing a machine-readable security element with a high level of forgery security and high resistance to circulation.

[0006] This object is achieved by the features of the independent claims. Further developments of the invention are the subject of the dependent claims. According to the invention, a film security element for protecting valuables comprises a film carrier and a selection layer applied at least partially to the film carrier.

[0007] The film carrier is made of an extrudable plastic and is provided in its volume with a machine-readable luminescence marker which is designed to emit luminescence radiation with a first wavelength and a second, different wavelength, each in the IR spectral range.

[0008] In addition, the selection layer is designed to spectrally selectively inhibit the transmission of IR radiation, whereby the inhibition of transmission differs by at least 10 percentage points at the first and second wavelengths.

[0009] The differences in transmission inhibition are given in this description in absolute percentage points, i.e. each related to a maximum transmission of 100%. The transmission and the inhibition of transmission add up to 100%. For example, the transmission of the selection layer at the first wavelength can be 70%, thus inhibiting transmission 30%, while the transmission at the second wavelength can be 55%, thus inhibiting transmission 45%. In this example, the difference in inhibition is 45 - 30 = 15 percentage points. Advantageously, the inhibition of transmission at the first and second wavelengths differs by 15 percentage points or more, or even by 20 percentage points or more.

[0010] In an advantageous embodiment, the selection layer has a high transmission of more than 50%, in particular more than 70%, at the excitation wavelength of the luminescence marker. This allows luminescence excitation to also occur through the selection layer. The first and second wavelengths preferably differ by at least 30 nm, more preferably by at least 50 nm, and most preferably by at least 100 nm.

[0011] The first and second wavelengths are both advantageously between 750 nm and 2500 nm, preferably between 800 nm and 2200 nm. Specifically, the first wavelength can be, for example, 1100 nm and the second wavelength 1600 nm.

[0012] The luminescence marker advantageously comprises inorganic pigments doped with transition elements or rare earth elements, in particular neodymium, ytterbium, erbium, thulium, holmium, or mixtures thereof. The luminescence marker is advantageously present in a proportion of 0.001% to 10%, preferably between 0.001% and 0.1%, based on the mass of the film carrier.

[0013] The luminescence marker is advantageously designed for excitation in the IR spectral range, but luminescence markers that can be excited in the visible or UV spectral range are also possible.

[0014] In an advantageous embodiment, the selection layer is formed by a metal layer, whereby the metal layer is not present over the entire surface, but only in certain regions. Suitable metallic materials include, in particular, Al, Cr, Ag, Au, Cu, Ni, Sn, or alloys of these materials. The metal layer can first be applied over the entire surface, for example by vapor deposition, and then removed again in certain regions, for example using a washing process, an etching process, or laser etching. However, the metal layer can also be applied specifically in the desired regions, for example using a metallic pigment. In another, equally advantageous embodiment, the selection layer is formed by an IR absorber layer with inorganic, organometallic, or organic pigments or dyes.The pigments can be formed, for example, from oxides, halides, phosphates, chalcogenides, vanadates, silicates, or germanates of transition metals (e.g., Zn, Ti, V, Gr, Mn, Fe, Co, Ni, Cu) or rare earth elements (e.g., Ge, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb). Advantageous organometallic compounds include, for example, phthalocyanines or naphthalocyanines; suitable organic compounds include, for example, CuH2Pc or porphyrins.

[0015] The selection layer is preferably applied to the film parallel to the main plane of the film, advantageously using a printing process. Parallel to the main plane of the film means, in particular, that the selection layer is arranged flatly on the film. Advantageously, the selection layer is not applied over the entire surface; alternatively, it can also be applied over the entire surface first and then appropriately structured.

[0016] The extrudable plastic is advantageously polyethylene terephthalate (PET), polypropylene (PP), biaxially oriented polypropylene (BOPP), polyethylene (PE) or a mixture of these plastics or a laminate of the same or different such layers.

[0017] Particularly advantageously, the machine-readable luminescent marker is evenly distributed throughout the film carrier. "Evenly" means that the local concentration of the machine-readable luminescent marker differs from the average concentration by no more than 10%, in particular by no more than 5%. The local concentration is, in particular, the number of luminescent marker particles, for example, grains, per specific area, for example, 1 mm 3 or 10 mm 3 , film carrier.

[0018] In a further development of the invention, the film security element is combined with further machine-readable substances, in particular with a magnetic coding, with UV fluorescent substances, with phosphorescent substances, with optically variable elements and / or a further luminescence marker arranged on the surface of the film security element.

[0019] If the foil security element is combined with magnetic coding, for example, magnetic blocks can be printed onto the foil in a block-like coding pattern. The magnetic blocks can differ in size, shape, height, coercivity, remanence, and / or the magnetic material used. In this case, the magnetic blocks also act as a blocker or inhibition for the luminescent marker.

[0020] The foil security element can also be combined with UV fluorescent substances, with at least one fluorescent color being applied at least partially to at least one side of the foil carrier. Two or more fluorescent colors can also be applied side by side, one above the other, or overlapping one another on one or both sides of the foil carrier.

[0021] In a further advantageous embodiment, the film security element is combined with phosphorescent substances that are applied in regions or over the entire surface of one or both sides of the film carrier.

[0022] Advantageously, the film security element can also be combined with a further luminescence marker which is applied at least partially or over the entire surface on one or both sides, wherein the further luminescence marker either absorbs electromagnetic IR radiation in the IR range or is transparent to it.

[0023] A combination with optically variable elements is also advantageous. Elements suitable for color-shifting effects, such as liquid crystals, thin-film vapor deposition, or OVI pigments, or optically variable microrelief elements such as holograms, micromirrors, microlenses, and the like, can be used.

[0024] The foil security element is preferably provided with an adhesive on at least one side, preferably on both sides, for better anchoring to the paper substrate. The adhesive is preferably heat-activated and / or radiation-activated.

[0025] In an advantageous design that is particularly easy to manufacture, the foil security element has only a single selection layer and no further reflection layer.

[0026] However, in a likewise advantageous embodiment, it is provided that a further selection layer is arranged on the side of the film carrier opposite the said selection layer or a reflection layer is arranged which reflects essentially uniformly in the infrared spectral range of the two said wavelengths.

[0027] The foil security element can contain only a single foil, namely the aforementioned foil carrier, but the foil carrier can also be coated with a second foil and can have one or more auxiliary or functional layers. The layers can be transparent, translucent, or opaque. The layers can contain plastics, lacquers, metals, dielectrics, adhesives, and / or other machine-readable materials.

[0028] The foil security element can in particular be designed as a security thread, security strip or patch.

[0029] The invention also includes a data carrier with a foil security element of the type described. The foil security element is preferably incorporated into the data carrier in a registered manner or applied to the data carrier. A registered insertion allows the code formed by the selection layer to be matched to the blank length of the data carrier. This enhances the security effect and also significantly increases the number of possible codes.

[0030] The invention further includes a method for producing a film security element of the type described. In the method, it is provided that an extrudable plastic is provided and mixed with a machine-readable luminescence marker which is designed to emit luminescence radiation with a first wavelength and a second, different wavelength, each in the IR spectral range, the plastic mixed with the luminescence marker is extruded into a film and a film carrier is cut from the film, and the film carrier is provided with a selection layer which is designed to spectrally selectively inhibit the transmission of IR radiation, wherein the inhibition of the transmission differs by at least 10 percentage points at the first and second wavelengths.

[0031] Finally, the invention also includes a method for testing, in particular authenticity testing, a film security element of the type described, in which the film security element is exposed to excitation radiation in order to excite the luminescence marker to emit luminescence radiation, the luminescence radiation emitted by the film security element is detected in a first region in which the selection layer is present and in a second region in which the selection layer is not present, and the luminescence radiation detected in the first and second regions is evaluated at the first and second wavelength in order to carry out the testing of the film security element.

[0032] In particular, on the basis of the evaluation, a decision can be made as to whether the tested foil security element or a data carrier provided with the foil security element is genuine or manipulated or counterfeit.

[0033] In an advantageous method variant, the foil security element is exposed to excitation radiation, and the luminescence radiation emitted by the foil security element is detected on opposite sides of the foil security element. The emitted luminescence radiation is transmitted through the selection layer, at least in part.

[0034] In another, equally advantageous method variant, the film security element is exposed to excitation radiation and the luminescence radiation emitted by the film security element is detected on the same side of the film security element. The emitted luminescence radiation is transmitted at least partially through the selection layer, for example, with the aid of a reflective layer present in the film security element, as explained in more detail with reference to the exemplary embodiment in Fig. 9.

[0035] During the extrusion process, an IR-transparent dark substance can be added to the plastic in addition to the luminescent marker, so that the film absorbs in the visible spectrum but is transparent in the IR spectrum. A liquid crystal ink, for example, can then be applied to the film substrate, resulting in a perceptible angle-dependent color change for the observer.

[0036] The advantages of the foil security element according to the invention include, in particular, an increase in the counterfeiting hurdle, an increase in the number of available machine-readable codes, and an improvement in machine authentication. When foil security elements are used on banknotes, machine banknote processing, in particular the recognition and sorting of different denominations and / or currencies, is also improved.

[0037] Further embodiments and advantages of the invention are explained below with reference to the figures, in which a true-to-scale and true-to-proportion reproduction has been omitted in order to increase clarity.

[0038] They show:

[0039] Fig. 1 schematically shows a banknote with a security thread according to an embodiment of the invention,

[0040] Fig. 2 shows schematically the security thread of Fig. 1 in cross section,

[0041] Fig. 3 schematically shows the emission spectrum of the luminescence marker used and the transmission curve of the selection layer,

[0042] Fig. 4 shows a security thread according to another embodiment of the invention with an additional full-surface selection layer,

[0043] Fig. 5 shows a security thread according to a further embodiment of the invention,

[0044] Fig. 6 shows a security thread according to a further development of the invention with an additional magnetic coding,

[0045] Fig. 7 shows a security thread according to a modification of Fig. 6, in which the magnetic blocks are additionally overprinted with a metal pigment ink, Figs. 8 - 10 show suitable measuring geometries for the authenticity testing of film security elements according to the invention, wherein Fig. 8 shows the excitation and measurement on opposite sides of a security thread, Fig. 9 shows the excitation and measurement on the same side of the security thread and Fig. 10 shows a transmission geometry as in Fig. 8, but with additional internal reflection.

[0046] The invention will now be explained using the example of security threads for banknotes. Figure 1 schematically shows a banknote 10 provided with a security thread 12 according to an embodiment of the invention. The security thread 12 can be arranged on the surface of the banknote 10 or embedded entirely or partially in the banknote paper. It is understood that film security elements according to the invention can also be designed, for example, in the form of a security strip, a security band, or a security patch.

[0047] The security thread 12 is equipped with a machine-readable coding 14 that cannot be visually detected without aids. The security thread 12 is registered and embedded in the substrate of the banknote 10, and the coding 14 is adjusted to the height of the banknote. This significantly increases the number of possible codings compared to an unregistered insertion and also improves counterfeit security.

[0048] Figure 2 shows the security thread 12 of Figure 1 in more detail, schematically in cross-section. In the simplest case, the security thread 12 consists of a foil carrier 20 coated with a luminescent marker and a selection layer 24 applied to one side of the foil carrier 20 in partial areas.

[0049] Specifically, the film carrier 20 in the embodiment is made of an extrudable

[0050] It is formed from a plastic material such as PET (polyethylene terephthalate) and is uniformly mixed throughout its volume with a machine-readable luminescent marker 22 in the form of a plurality of powdered particles. In the exemplary embodiment, the luminescent marker 22 is present in a proportion of 0.02% based on the mass of the film carrier 20.

[0051] The luminescence marker 22 is designed to emit luminescence radiation with a first characteristic wavelength 32 (Fig. 3) and a second, different characteristic wavelength 34, wherein both the first and the second wavelength lie in the infrared spectral range. For example, the first wavelength corresponds to a local emission maximum of the luminescence marker at approximately Xi = 1000 nm, and the second wavelength corresponds to a local emission maximum at approximately X2 = 1500 nm. Figure 3 schematically shows the emission spectrum 30 of the luminescence marker 22 with the two local emission maxima 32, 34 at the wavelengths Xi and X2.

[0052] In the exemplary embodiment according to Fig. 2, the selection layer 24 is arranged only on the upper side of the film carrier 20 and is also present on the upper side only in partial regions 26. The regions without the selection layer 24 can also be formed at the respective outer edge of the selection layer instead of in the center, but in particular also form recesses 28 in the selection layer 24, for example in the form of an alphanumeric character string, in order to generate a negative text in the security thread 12.

[0053] The selection layer 24 is matched to the luminescence marker 22 used and is designed to spectrally selectively inhibit the transmission of the IR radiation emitted by the luminescence marker 22. The transmission inhibition differs by at least 10 percentage points between the first and second wavelengths 32, 34.

[0054] For illustration, Fig. 3 shows not only the emission spectrum 30 but also the spectral curve 36 of the transmission of the selection layer 24. As can be seen from the figure, the IR transmission of the selection layer 24 at the first wavelength X1 is approximately 40%, thus correspondingly inhibiting transmission by 60%. At the second wavelength X2, the IR transmission of the selection layer 24 is approximately 60%, thus correspondingly inhibiting transmission by 40%. The inhibition of IR transmission by the selection layer 24 thus differs by 20 percentage points at the two wavelengths.

[0055] The testing of such a security thread for authenticity is described in more detail below with reference to Figures 8 to 10.

[0056] Figure 4 shows, as a further exemplary embodiment of the invention, a security thread 40 which is fundamentally constructed like the security thread 12 of Figure 2, but in which a full-surface selection layer 42 is additionally applied to the underside of the film carrier. The additional selection layer 42 can have the same spectral selectivity as the first selection layer 24, but can also have a different spectral selectivity. Instead of a selection layer, a reflection layer with a spectrally essentially uniform reflection in the infrared can also be provided as the additional layer 42. Of particular relevance here is the spectral range containing the first and second wavelengths. Reflection of the emitted luminescence radiation by such a reflection layer does not change the spectral signature of the luminescence radiation.For example, the reflection layer can have a reflectivity of 80% at the first wavelength Xi = 1100 nm and a reflectivity of 82% at the second wavelength X2 = 1600 nm, so that both wavelengths are reflected with essentially the same intensity.

[0057] In a further embodiment of the invention, the additional layer 42 can also be provided only in certain regions and, in particular, can be provided with recesses 44, as illustrated in Fig. 5. The additional layer 42 can be formed either by a spectrally selective selection layer or by a spectrally uniformly reflecting reflection layer. In a further development of the invention, the security threads can be combined with other machine-readable materials, such as a magnetic coding. For illustration, Fig. 6 shows a security thread 50 that is fundamentally constructed like the security thread 12 of Fig. 2, but in which additional magnetic blocks 52, 54 made of two different magnetic materials are printed onto the selection layer 24 in a block-like coding. The magnetic blocks 52, 54 form an additional barrier to the IR transmission of the eumescence marker 22.

[0058] In the modification of Fig. 7, the magnetic blocks 52, 54 of the security thread 50 of Fig. 6 are additionally overprinted with a metallic pigment ink 56. It is understood that the two-sided designs of Figs. 4 and 5 can also be combined with machine-readable materials, such as the magnetic codes and metallic pigment overprint of Figs. 6 and 7. The magnetic blocks can be arranged on one or both selection layers (or the selection layer and the reflection layer).

[0059] Figures 8 to 10 illustrate, by way of example, some suitable measuring geometries for the authenticity testing of film security elements according to the invention.

[0060] In a first measurement geometry shown in Fig. 8, a security thread 12 provided with a selection layer 24 on its front side is used, as shown, for example, in Fig. 2. The security thread 12 is exposed to excitation radiation 62, for example IR radiation, from an excitation light source 60 from the uncoated back side in order to excite the luminescence of the luminescence marker 22. On the opposite front side of the security thread 12, the emitted luminescence radiation 66, which may have been filtered or spectrally modified by the selection layer 24, is recorded by a sensor 64 and further processed and evaluated in an evaluation unit. More precisely, the luminescence marker 22, which is uniformly distributed throughout the volume of the film carrier 20, is excited to luminescence by the excitation radiation 62.In the exemplary embodiment, the luminescence marker 22 emits IR radiation with local emission peaks at Xi = 1100 nm and X2 = 1600 nm with a specific intensity ratio specified by the emission spectrum 30. For the luminescence marker with the emission spectrum shown in Fig. 3, the intensity ratio Lei of the two wavelengths is

[0061] Lei = For example, I(X1) / I(X2) is about 1.3.

[0062] In the regions 28 of the security thread 12 in which no selection layer 24 is arranged on the front side, the emitted luminescence radiation is essentially unchanged on the way to the sensor 64, in particular regardless of the additional selection layer 42, so that the spectral distribution of the luminescence radiation 66 recorded by the sensor 64 corresponds to the emission spectrum 30 of Fig. 3. As a reference value of the unchanged emission spectrum 30, in particular the intensity ratio of the intensities of the two wavelengths Xi and X2 can serve.

[0063] In the partial areas 26 with the selection layer 24, the radiation emitted by the luminescence marker 22 is spectrally selectively inhibited upon passing through the selection layer, thereby changing the intensity ratio Lei.

[0064] In the embodiment, the selection layer 24 has an IR transmission of 40% at the wavelength Xi and a transmission of 60% at the wavelength X2 (Fig. 3), so that the luminescence radiation 66 transmitted through the selection layer 24 has a changed intensity ratio

[0065] Lel / sel = (40% * I(X1)) / (60% * I(X2)) = 2 / 3 * Lei « 0.66 * Lei. The different intensity ratio Lei or I re i / sei in the areas with or without selection layer 24 represents a reliable authenticity mark, but one that is difficult for a forger to recognize and reproduce.

[0066] Furthermore, by incorporating the luminescence marker 22 into the volume of the film carrier 20, the durability of the luminescence marker of the security thread 12 is significantly increased, since the feature substance present inside the security thread cannot be scraped off over time, as is the case with conventional, printed feature substances.

[0067] The described method can also be used to classify banknotes. For example, the different denominations of a banknote series can be equipped with security threads that contain the same luminescence marker within the volume of the foil carrier, but are equipped with different selection layers with different inhibition levels for the two characteristic wavelengths.

[0068] For example, instead of the above-mentioned selection layer 24, another selection layer can be used which has an IR transmission of 50% at the wavelength Xi and a transmission of 90% at the wavelength Ä2, so that the luminescence radiation transmitted through the selection layer has a changed intensity ratio

[0069] Lel / sel2 = (50% * I(X1)) / (90% * I(X2)) = 5 / 9 * Lei « 0.55 * Lei. The detection and comparison of the luminescence radiation in the areas with and without a selection layer then allows both an authentication of the banknotes and the identification of the respective denomination. For example, the changed intensity ratio Lei / sei ~ 0.66 * Lei belongs to a first denomination, the changed intensity ratio I rei / sei2 ~ 0.55 * Lei to a second denomination. Figure 9 shows an embodiment in which the authenticity check can be performed on a security thread 40 by reflection. This allows for a particularly simple design, since the excitation source 60 and the sensor 64 can be arranged side by side, and even in the same device. A security thread 40, such as that shown in Fig. 4, is used here, with a selection layer 24 on the front side of the thread and a spectrally broadband uniformly reflecting reflection layer 42 on the back side of the thread.

[0070] In the reflection geometry shown, both the excitation of the luminescence marker 22 with the excitation light source 60 and the detection of the emitted luminescence radiation 66 with the sensor 64 on the front side of the thread take place. IR radiation of a wavelength to which the selection layer 24 is largely permeable is advantageously used as the excitation radiation 62.

[0071] Since the reflection layer 42 does not change the emission spectrum of the luminescence marker 22 due to its broadband uniform reflection, the evaluation can be carried out by comparing the intensity ratios Lei, Lei / sei essentially as described in Fig. 8.

[0072] Finally, the embodiment shown in Fig. 10 utilizes a transmission geometry with additional internal reflection. Shown is a security thread similar to the security thread shown in Fig. 5 with two selection layers 24-1 and 24-2, each provided with cutouts, which can have the same or different spectrally selective properties.

[0073] In this geometry, too, the excitation radiation 62 of the excitation light source 60 excites the luminescence marker 22 to emit luminescence radiation at the two wavelengths Xi and X2. In the areas 28 of the selection layer 24-1 that are not covered, the generated luminescence radiation can reach the sensor 64 directly, while in the areas 26 with the selection layer 24-1, the emitted IR radiation passes through the upper selection layer and is spectrally selectively inhibited by it, as described above.

[0074] The generated luminescence radiation can also reach the sensor 64 via a different path, namely by first being reflected by the upper selection layer 24-1 and then by the lower selection layer 24-2, and only then passing through a recessed area 28 or a coated area 26 to the sensor 64. Multiple reflections within the film element are also possible. By appropriately selecting the spectrally selective reflectivity of the selection layers 24-1, 24-2, these internal reflections can enhance the spectrally selective inhibition and / or introduce additional spectral signatures into the measurement signal.

[0075] List of reference symbols

[0076] Banknote

[0077] Security thread

[0078] Coding

[0079] Film carrier

[0080] Luminescence markers

[0081] Selection layer

[0082] Subareas with selection layer

[0083] recesses

[0084] Emission spectrum first characteristic wavelength second characteristic wavelength security thread additional layer

[0085] Security thread, 54 magnetic blocks

[0086] metallic pigment paint

[0087] Excitation light source

[0088] Excitation radiation

[0089] Sensor emitted luminescence radiation

Claims

Patent claims 1. A film security element (12) for securing valuables, comprising a film carrier (20) and a selection layer (24) applied at least in part to the film carrier, wherein the film carrier (20) is formed from an extrudable plastic and is offset in its volume with a machine-readable luminescence marker (22) which is designed to emit luminescence radiation with a first wavelength and a second, different wavelength, each in the IR spectral range, and the selection layer (24) is designed to spectrally selectively inhibit the transmission of IR radiation, wherein the inhibition of the transmission differs by at least 10 percentage points at the first and second wavelengths.

2. Foil security element (12) according to claim 1, characterized in that the first and the second wavelength differ by at least 30 nm, preferably by at least 100 nm.

3. Foil security element (12) according to claim 1 or 2, characterized in that the first and second wavelengths are both between 750 nm and 2500 nm, preferably between 800 nm and 2200 nm.

4. Foil security element (12) according to at least one of claims 1 to 3, characterized in that the selection layer (24) is formed by a metal layer or an IR absorber layer with inorganic, organometallic or organic pigments or dyes.

5. Foil security element (12) according to at least one of claims 1 to 4, characterized in that the extrudable plastic is PET, PP, BOPP, PE or a mixture of these plastics.

6. Foil security element according to at least one of claims 1 to 5, characterized in that the machine-readable luminescent marker (22) is evenly distributed in the foil carrier (20).

7. Foil security element (12) according to at least one of claims 1 to 6, characterized in that the security element (12) is combined with further machine-readable substances, in particular with a magnetic coding, with UV fluorescent substances, with phosphorescent substances, with optically variable elements, and / or a further luminescence marker arranged on the surface of the foil security element.

8. Foil security element (12) according to at least one of claims 1 to 7, characterized in that on the side of the foil carrier (20) opposite the said selection layer (24) there is arranged a further selection layer or a reflection layer which reflects substantially uniformly in the infrared spectral range of the two wavelengths.

9. Foil security element (12) according to at least one of claims 1 to 8, characterized in that the foil security element (12) is designed as a security thread, security strip or patch.

10. Data carrier (10) with a foil security element (12) according to at least one of claims 1 to 9.

11. Data carrier according to claim 10, characterized in that the film security element (12) is incorporated in the data carrier in a registered manner or is applied to the data carrier.

12. A method for producing a film security element (12) according to one of claims 1 to 9, in which an extrudable plastic is provided and mixed with a machine-readable luminescence marker (22) which is designed to emit luminescence radiation with a first wavelength and a second, different wavelength, each in the IR spectral range, the plastic mixed with the luminescence marker (22) is extruded into a film and a film carrier (20) is cut from the film, and the film carrier (20) is provided with a selection layer (24) which is designed to spectrally selectively inhibit the transmission of IR radiation, the inhibition of the transmission differing by at least 10 percentage points at the first and second wavelengths.

13. Method for testing, in particular authenticity testing, a film security element (12) according to one of claims 1 to 9, in which the film security element (12) is subjected to excitation radiation in order to excite the luminescence marker (22) to emit luminescence radiation, the luminescence radiation emitted by the film security element (12) is detected in a first region in which the selection layer (24) is present and in a second region in which the selection layer is not present, and the luminescence radiation detected in the first and second regions is evaluated at the first and second wavelength in order to carry out the testing of the film security element (12).

14. The method according to claim 13, characterized in that the exposure of the film security element (12) to excitation radiation and the detection of the luminescence radiation emitted by the film security element (12) takes place on opposite sides of the film security element (12) and the emitted luminescence radiation is transmitted at least partially through the selection layer (24).

15. The method according to claim 13, characterized in that the exposure of the film security element (12) to excitation radiation and the detection of the luminescence radiation emitted by the film security element (12) takes place on the same side of the film security element (12) and the emitted luminescence radiation is transmitted at least partially through the selection layer (24), in particular with the aid of a reflection layer (42) present in the film security element.

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