SAFETY ELEMENT WITH A MACHINE-READY CODE AND METHOD FOR MANUFACTURING A SAFETY ELEMENT

Description

[0001] The present invention relates to a security element, preferably in the form of a foil strip, foil thread or foil patch, with a machine-readable code and a method for producing such a security element.

[0002] To protect against counterfeiting, valuable documents are typically provided with security elements that implement security features with visually and / or machine-verifiable properties, which can be used to verify the authenticity of the valuable document. Various security features are known from the state of the art for this purpose, which differ particularly with regard to the technical means by which the security feature can be detected or verified.

[0003] Of particular importance are visual security features with optically variable properties, i.e., the appearance of the visual security feature varies depending on the viewing angle. Continuously changing the viewing angle makes it possible to visualize a tilting and / or movement effect. Such security features are considered highly counterfeit-proof, as the viewing-angle-dependent, optically variable effect generally cannot be captured with sufficient precision for a counterfeiter to imitate it. Furthermore, such optically variable effects cannot be created using conventional printing processes. Examples of optically variable security features include moiré magnifiers, tilting images, holograms, and thin-film elements.

[0004] The authenticity of valuable documents should be verifiable not only visually but also mechanically. Mechanical verifiability offers a high level of security and is even mandatory in many technical applications, for example, in banknote processing. Devices such as automatic counting machines and vending machines should be able to recognize denominations and / or verify the authenticity of a banknote.

[0005] Known security threads and / or foil elements with visual, particularly optically variable, security features do not offer effective machine readability. It is only known to provide such security elements with codes based on infrared-absorbing substances, which are relatively easy to replicate or counterfeit. Magnetic substances, on the other hand, are generally clearly visible in both incident and transmitted light, so they can disrupt the visual appearance of visual, particularly optically variable, security features.

[0006] Security elements and / or value documents with polymer substrates generally do not have machine-readable security features integrated into the substrate. Printing magnetic codes is a common practice, particularly for banknotes with polymer substrates. The disadvantage of this is that the printed magnetic code is easily rubbed off, especially on banknotes in circulation. Furthermore, the magnetic substances applied to the banknotes can be removed, analyzed, and / or reproduced relatively easily by a counterfeiter. Direct use of the removed magnetic substances for counterfeiting is also possible.

[0007] Printing inks with magnetic pigments for intaglio printing or gravure printing are known, for example, from EP 2 417 207 B1.

[0008] DE 10 2016 014 230 A1 describes a value document comprising a value document substrate with a value document substrate control feature and an elongated security element with a security element control feature incorporated into the value document substrate. The security element extends from one end of the value document substrate to another end of the value document substrate and is incorporated into the value document substrate such that the security element control feature is aligned with the value document substrate control feature, and the security element has precisely one long magnetic code that extends substantially over the entire length of the elongated security element incorporated into the value document substrate.

[0009] WO 2008 / 008635 A2 describes a synthetic micro-optical system and a security device comprising an in-plane image formed from an array or pattern of image symbols and an array of focusing elements. The system generates at least two different synthetic images, one synthetic image serving to modulate or control the extent of appearance of another synthetic image. The array of image symbols may form a synthetic in-plane image, while the interaction of the array of focusing elements with the array of image symbols forms a separate synthetically magnified image serving to control the field of view of the in-plane image and thus modulate or control the extent of appearance of the in-plane image.The appearance of the image in the plane appears and disappears or turns on and off depending on the viewing angle of the system.

[0010] WO 2018 / 104231 A1 relates to low-energy radically curable printing inks for offset or letterpress printing of security documents, in particular to low-energy radically curable offset or letterpress printing inks for offset or letterpress printing on a substrate or security document. Low-energy radically curable inks have a viscosity in the range of about 2.5 to about 25 Pa s at 40°C and 1000 s-1 and contain radically curable (meth)acrylate compounds, one or more photoinitiators, one or more machine-readable materials, and one or more fillers and / or extenders.

[0011] Against this background, the object of the present invention is to propose a solution to the aforementioned problems. In particular, there is a need for a security element with a machine-readable code that can be reliably verified for authenticity.

[0012] The present invention solves this problem by the appended independent claims. Preferred embodiments of the invention are specified in the dependent claims.

[0013] According to a first aspect of the present invention, a security element is provided, preferably in the form of a film strip (also: security strip), film thread (also: security thread), or film patch (also: security patch). The security element has a machine-readable code. According to the invention, the machine-readable code is a magnetic coding produced by printing technology using at least two opaque magnetic printing inks, each containing different magnetic pigments. The magnetic printing inks or their magnetic pigments differ in terms of their coloring and / or magnetic properties, in particular their coercivity, and are incorporated or applied in defined code areas of the security element. The magnetic printing inks incorporated or applied in the code areas provide at least part of a visual security feature visible when viewed from above the security element.

[0014] In other words, it is proposed to produce a magnetic coding using magnetic printing inks or magnetic printing inks that represent part of a visible visual security feature, such as part of a single- or multi-coloured motif print that is visible when viewed from above on the security element.

[0015] This minimizes any interference from the magnetic coding on the visual appearance of the security element. Visual and magnetic security features can be detected with equal reliability.

[0016] The security element preferably serves to increase the forgery barrier of a security document. Security documents include, in particular, banknotes, shares, identification documents, credit cards, certificates, insurance cards, and generally vulnerable documents, including product security elements such as labels and packaging for high-value products and the like. For the purposes of this description, the term "security document" encompasses not only finished, circulating security documents, but also precursors of security documents, such as security papers that do not possess all the features of a circulating security document, for example, security papers in sheet or roll form.The security elements comprise, for example, foil elements in the form of threads, strips or patches that are applied to a value document or at least partially incorporated into a value document, such as window security threads and pendulum security threads, or that are used to cover through openings in a value document.

[0017] The detection or verification of magnetic coding involves detecting the magnetic printing inks or printing ink layer based on the magnetic properties of the associated magnetic pigments. Authentication of the security elements includes, for example, determining a magnetic field, a magnetic flux density, a magnetization, a remanence, a coercivity, and / or a hysteresis. For verification purposes, the magnetic properties of the magnetic pigments or their distribution can be visualized, for example, using known magnetic sensors and / or magneto-optical systems.

[0018] Compared to security elements with codes based on substances that absorb light in the infrared spectral range, magnetic coding presents a higher barrier to counterfeiting. Furthermore, security elements such as security threads with optically variable properties and magnetic codes are more machine-readable than those that are only designed with codes that absorb light in the infrared spectral range.

[0019] The visual security feature is implemented, for example, in simple designs by means of code areas visibly provided in or on the security element, which are printed with different magnetic printing inks, for example in the form of motifs or symbols. The magnetic printing inks used are opaque and preferably correspond to one or more body colors that represent the visual appearance of the visual security feature. The code areas printed with such magnetic printing inks provide a machine-readable magnetic coding that does not disrupt the design or appearance of the visual security feature and is generally indistinguishable from it without additional aids.

[0020] The code areas are, for example, spatially separated or at least partially overlapping areas in which the magnetic printing inks are inserted or applied.

[0021] According to possible embodiments, the at least two magnetic printing inks correspond to the same color and differ in terms of their magnetic properties, in particular coercivity ("magnetic gemini").

[0022] According to other possible embodiments, the at least two magnetic printing inks correspond to different colors and do not differ with regard to their magnetic properties, in particular with regard to their coercivity ("magnetic solitary").

[0023] Alternatively, the at least two magnetic printing inks differ both in terms of their color and in terms of their magnetic properties, in particular in terms of their coercivity.

[0024] In advantageous embodiments, two or more magnetic printing inks are used, whose magnetic pigments differ in their magnetic coercivity. In this case, the code areas are characterized by areas with high magnetic coercivity and areas with low magnetic coercivity (so-called HiCoLoCo magnetic coding).

[0025] In preferred embodiments, the visual security feature is an optically variable security feature that has a visual appearance dependent on the viewing angle. The visual appearance of the optically variable security feature is determined at least in part by at least one of the incorporated or applied magnetic printing inks. The code areas printed with magnetic printing inks thus provide a machine-readable magnetic coding that is visually evident in the design or appearance of the optically variable security feature and does not disrupt it. Preferably, the code areas in which the magnetic printing inks are incorporated or applied are not identifiable in the visual appearance of the visual security feature without additional aids.

[0026] It is understood that further printing inks with magnetic and / or non-magnetic pigments can be provided to represent the optical appearance of the visual security feature, in particular the optically variable security feature.

[0027] The optically variable security feature preferably comprises a micro-optical relief structure, in particular a microlens array of, for example, spherical or aspherical lenses, rod lenses, and / or cylindrical lenses, wherein at least one of the magnetic printing inks incorporated or applied in the code areas is covered by the micro-optical relief structure. Such configurations thus have an internal magnetic coding that is well protected against mechanical abrasion by the overlying micro-optical relief structure.

[0028] According to advantageous embodiments, the optically variable security feature comprises a moiré magnifier. Moiré magnifiers are multilayer structures comprising a focusing micro-optical relief structure, typically a microlens array, a transparent or translucent image layer with an array of image elements, in particular microimages, and optionally a spacer layer between the micro-optical relief structure and the image layer. The image elements or microimages are magnified or optically altered in some other way when viewed through the lenses. Additional functional layers and / or auxiliary layers may also be present.

[0029] Preferably, the at least two magnetic printing inks are incorporated into micro-recesses, in particular into micro-recesses for image elements such as microimages embossed in a transparent or translucent image layer or embossing lacquer layer of the security element. Such embodiments can thus utilize the embossed micro-recesses of a visual, in particular optically variable, security feature for an additional magnetic feature, namely as a code area for the magnetic coding.

[0030] In particular, micro-recesses for microimages, which are imaged or enlarged using micro-optical relief structures to generate the optically variable security feature, typically have very small dimensions and are therefore inherently difficult to imitate.

[0031] In advantageous embodiments, the magnetic pigments of the magnetic printing inks incorporated into the micro-recesses have a diameter of less than 2 µm. Such small-sized magnetic pigments are particularly suitable for coloring micro-recesses for microimages of optically variable security features, such as moiré magnifiers, and for providing code areas there for machine-readable magnetic coding.

[0032] Alternatively or additionally, the security element has an opaque cover layer which is printed at least partially over its entire surface with at least one of the magnetic printing inks or is formed as an ink layer of at least one of the magnetic printing inks. In such embodiments, larger areas can typically be realized, particularly compared to the micro-recesses, which provide improved coding and machine readability. In such embodiments, the magnetic coding is, for example, a motif print with cutouts, i.e. a so-called clear text or negative print, or a motif print in the form of characters and / or patterns. Such a clear text or negative print with cutouts can, for example, also be produced using just one magnetic printing ink.

[0033] The magnetic pigments of the at least two magnetic printing inks with which the opaque cover layer is printed or by means of which the opaque cover layer is formed preferably have a diameter between 2 µm and 10 µm, particularly preferably between 3 µm and 5 µm.

[0034] According to possible embodiments of the invention, the magnetic pigments of the at least two magnetic printing inks comprise a magnetized or magnetizable core encased or coated by an opaque dye. This means that the magnetized or magnetizable core is at least partially, preferably completely, surrounded by the opaque dye. Magnetic pigments with such a structure are known per se and can be produced, for example, according to the teachings of EP 2 152 821 B1. The ink layer can have an opaque body color different from the core, such as red, green, blue, white, black, and / or be metallically lustrous, for example imparting a metallic luster corresponding to that of silver, gold, copper, chromium, or another metal.

[0035] In preferred embodiments, the dye surrounding the core contains silver or silver compounds. It has been found that a magnetic printing ink with silver-coated pigments applied to one side of the security element may, under certain circumstances, be significantly less visible on the opposite side. In this way, in particular, a magnetic coding can be realized that is only faintly visible on the visible side or when viewed from above. In these cases, disruptive influences caused by the magnetic coding on any optically variable security features present are reduced or largely eliminated.

[0036] In advantageous embodiments, at least one of the magnetic printing inks is incorporated or applied in one of the code areas in a variable layer thickness, which represents a further security feature for increasing protection against counterfeiting. The code areas are therefore not necessarily printed evenly; in particular, it is provided to print the code areas with magnetic printing inks in a continuous pattern and / or to apply a variable layer thickness of ink there.

[0037] According to possible embodiments, at least two of the code areas in which the at least two magnetic printing inks are incorporated or applied are configured as spaced-apart areas in plan view or are arranged overlapping one another in plan view. For this purpose, for example, one code area is printed with the at least two magnetic printing inks.

[0038] A second aspect of the present invention relates to a value document, in particular a banknote, which has a security element with the features described here. Advantages of the value document secured with the security element described above, particularly with regard to forgery security, are immediately apparent from the description with reference to the security element according to the invention.

[0039] To secure the valuable document, possible embodiments provide for the provision of multiple security elements that are connected to the valuable document in a register-accurate manner, particularly in such a way that they cannot be removed from the valuable document or can only be removed with considerable technical effort. Such embodiments enable the combination of magnetic coding and / or visual, particularly optically variable, security features provided by different security elements, particularly in such a way that the totality of the different security elements provides a comprehensive information item by which the authenticity of the valuable document can be verified.

[0040] In possible embodiments, the combination of magnetic coding on a security thread and / or a security patch applied to the value document and / or security strips and / or further security elements printed on the value document results in a total information, wherein the following combinations are preferably provided: printed security features and magnetic security features of a security thread; printed security features and magnetic security features of a security patch and / or security strip; magnetic security features of a security thread and a security patch and / or security strip; printed security features and magnetic security features of a security thread and magnetic security features of a security patch and / or security strip.

[0041] The corresponding security elements or security features can in particular be applied to the front or back of the security document or banknote or can be embedded inside the security document or in one of the security elements.

[0042] By reading the magnetic codes described here, denomination recognition of a banknote provided with the security element is preferably enabled. Unlike codes based on substances absorbing in the infrared spectral range, the magnetic code is easily readable regardless of the orientation of the security element or a valuable document provided with the security element. This enables, in particular, reliable reading of banknotes with such security elements in a banknote processing machine, for example, for denomination recognition. The signals of the magnetic code are generally stronger than those generated by magnetic printing elements such as SPARK® or magnetic numbering.

[0043] A third aspect of the present invention relates to a method for producing the security element described above, wherein the magnetic coding is produced by printing technology in that the at least two opaque magnetic printing inks, each containing different magnetic pigments, are incorporated or applied in defined code areas of the security element in such a way that they provide at least part of a visual security feature, in particular an optically variable security feature.

[0044] For example, an intaglio printing process or a gravure printing process can be used as a printing process.

[0045] The at least two magnetic printing inks are preferably used to produce image elements, such as microimages of optically variable security features, and / or as an additional, substantially planar, in particular full-surface, print. In embodiments, for example, it is provided to produce a HiCoLoCo magnetic coding that is visually unobtrusive or hidden, in particular in the image elements or in opaque white.

[0046] It is also possible to create an additional or combined coding based on substances that absorb in the infrared spectral range (IR). IR-absorbing pigments from SICPA (SICPA SA, AVE de Florian 41, 1008, Prilly, Switzerland) or printing inks sold under the trade name SICPATALK® are preferred in this context.

[0047] Further aspects, features and advantages of the present invention will become clear from the following detailed description of preferred embodiments and variants with reference to the accompanying figures, which show: Fig. 1 shows a value document with security elements in plan view according to possible embodiments of the invention; Fig. 2 shows a further value document with security elements in plan view according to possible embodiments of the invention; Fig. 3 shows a security element with an optically variable security feature and a magnetic coding according to a possible embodiment of the invention in a schematic cross-sectional view, wherein the magnetic coding is formed by printing technology using different magnetic pigments of two magnetic printing inks; Fig. 4 shows a security element with code areas of a magnetic coding in a schematic cross-sectional view, which is designed as a partially opaque cover layer; Figures 5 to 13 show embodiments of the security element according to the invention with magnetic codings in plan view, which are based on two different magnetic printing inks; Fig. 14a to 14e show schematic embodiments with running orUnevenly printed code areas with magnetic ink in plan view, which represent visual security features.

[0048] The invention is explained below by way of example with reference to the drawings, which illustrate specific embodiments of the invention. These embodiments are described in detail and enable those skilled in the art to implement the invention technically. The described embodiments are not mutually exclusive, but rather complement one another. In this respect, a certain feature, a certain structure, or a certain property described in connection with one embodiment can also be implemented in connection with other embodiments without departing from the subject matter of the invention. Furthermore, the position or arrangement of individual elements or steps within the described embodiments can of course be modified without departing from the subject matter of the invention.Therefore, the following description of the attached figures is not to be understood as limiting, since the scope of the invention is defined exclusively by the appended claims and also includes variants and equivalents not expressly described below.

[0049] Fig. 1 shows a schematic plan view of a value document 100 which is provided with different security elements 10, which are preferably arranged in a defined position, in particular in register, relative to one another and with respect to the value document 100. Shown are security elements 10 which are designed, for example, as a security thread 10a, window security thread 10b, security strip 10c or security patch 10d. In the case of the Fig. 1The value document 100 shown, for example, is a banknote with a cotton paper substrate into which the security thread 10a is embedded. The security thread 10b is a so-called window thread, which is embedded in the substrate of the value document 100 in such a way that it is visible alternately in windows 11b on opposite sides of the value document 100.

[0050] Fig. 1 shows a plurality of different security elements 10, 10a, 10b, 10c, 10d, which do not necessarily have to be implemented in the illustrated entirety. It is understood that even a single security element 10, particularly with register-accurate application, can provide a sufficiently forgery-proof security feature for the value document 100. In preferred embodiments, several security elements 10 can be provided to increase the forgery security, such as, for example, any combination of the Fig. 1 security features shown 10.

[0051] Fig. 2 shows an example of another value document 100 with security elements 10, which are designed as security strips 10c or security patches 10d. Fig. 2 The value document 100 shown can, for example, be a banknote with a polymer substrate, in particular made of polyethylene terephthalate, or a film composite banknote.

[0052] The security elements 10 are provided with a machine-readable code comprising a magnetic coding, which is produced by printing in code areas C1, C1, C3 by opaque magnetic printing inks M1, M2, M3 applied there at least in some areas. Corresponding embodiments show, by way of example, the Figures 3 and 4 in cross-section or the Figures 5 to 14 under supervision.

[0053] At least two of the magnetic printing inks M1, M2, M3 contain magnetic pigments of different types such that they differ in terms of their color and / or magnetic properties, for example, in terms of their coercivity. The magnetic coding encodes, for example, information associated with the security element 10 or the value document 100, such as a denomination or the like. In other words, the denomination of the value document 100 can be recognized based on the magnetic coding. The authenticity verification of the security elements 10 includes the detection of the magnetic printing inks M1, M2 or the magnetic pigments based on their magnetic properties using magnetic sensors, preferably in combination with the detection of a visual security feature correlated with the magnetic coding.

[0054] The Figures 3 to 14show security elements 10 with magnetic codings, which provide part of a visual security feature in the code areas C1, C2, C3, in particular the magnetic printing inks M1, M2 introduced into the code areas C1, C2 provide an optically variable security feature at least in part (see Figs. 3, 4 ).

[0055] The code areas C1, C2, C3 visible in plan view of the front side of the security element 10 are created by magnetic printing inks M1, M2, M3 which contain magnetic pigments and are incorporated or applied there.

[0056] Fig. 3shows a cross-section of a security element 10 that implements a visually detectable, optically variable security feature, in particular a moiré magnifier. The security element 10 has a multi-layer structure, wherein a micro-optical relief structure 11, which in the exemplary embodiment is provided by a microlens array, forms the uppermost layer on the visible side or in plan view and thus protects the underlying layers from mechanical abrasion. The illustrated micro-optical relief structure 11 or microlens array comprises a plurality of microlenses 18 that are focused on underlying image elements 16 (also: micro images). When viewed through the micro-optical relief structure 11, the image elements 16 are magnified or optically altered in some other way to create the variable optical effect.

[0057] The Moire Magnifier of the Fig. 3further comprises a spacer layer 12, which is arranged between the relief structure 11 and an image layer 13 containing the image elements 16, as well as functional layers 14, 15. In the functional layer 14, for example, further machine-readable features can be implemented in a manner not shown in detail. The further functional layer 15 consists, for example, of an adhesive layer for the intended attachment of the security element 10 to the value document 100. In the illustrated embodiment, the image layer 13 consists of a transparent embossing lacquer in which micro-recesses 17 are embossed. Alternatively, the image layer 13 can be formed from a translucent material. The micro-recesses 17 are filled with at least one of the magnetic printing inks M1, M2 and form the image elements 16 as so-called microimages.

[0058] The microlenses 18 and the image elements 16 each form a two-dimensional arrangement. The image layer 13 and the micro-optical relief structure 11 (microlens array) generate the optically variable security feature. The security feature optionally contained in the functional layer 14 is based, for example, on substances incorporated therein that are absorbent in the infrared spectral range and fluorescent and / or phosphorescent in the visible spectral range. According to other variants, the functional layer 14 comprises primers or ink-accepting layers.

[0059] In the Figs. 3 and 4In the illustrated embodiments, the code areas C1, C2 are achieved by filling the micro-recesses 17 not with any colored substance, but with one or more magnetic printing inks M1, M2. As a result, the magnetically readable or magnetic code is generated in an inner region of the security element 10, which is well protected from external mechanical influences, particularly when the security element 10 or the value document 100 with the security element 10 is in circulation.

[0060] Since the micro-recesses 17 are at least partially filled with magnetic printing inks M1, M2, these substances determine a visual appearance that depends on the viewing angle.

[0061] Due to the small spatial extent of the micro-recesses 17, the magnetic pigments of the magnetic printing inks M1, M2 which are introduced there preferably have a diameter of less than 2 µm.

[0062] The magnetic pigments of the magnetic printing inks M1, M2, and M3 preferably comprise a magnetized or magnetizable core encased in an opaque dye. The dye corresponds to an opaque body color, for example, red, green, blue, black, or white, and / or has a metallic luster, for example, corresponding to the metallic luster imparted by silver, gold, copper, chromium, or another metal.

[0063] According to possible variants, at least two of the magnetic printing inks M1, M2, M3 correspond to the same color and differ in their magnetic properties, in particular coercivity. In alternative embodiments, the at least two magnetic printing inks M1, M2, M3 correspond to different colors and do not differ in their magnetic properties. In general, the magnetic printing inks M1, M2, M3 can differ both in their color and their magnetic properties.

[0064] In a further embodiment, not shown in detail, the Fig. 3The functional layer 14 shown is designed as an opaque, i.e., essentially light-impermeable, cover layer. The opaque cover layer is printed in areas with magnetic printing inks M1, M2, M3 on the side facing away from the micro-optical relief structure 11, so that these are barely visible or not visible at all from the visible side or from above, and thus have little or no disruptive effect on the optically variable appearance of the optically variable security feature. The full-surface printing with magnetic printing inks M1, M2, M3 enables the realization of larger code areas C1, C2, C3, which can be reliably read using conventional magnetic sensors.In order to generate signatures that can be detected even better, magnetic printing inks M3 with magnetic pigments are preferably used, which have a larger diameter than the pigments introduced into the micro-recesses 17, for example between 2 µm and 10 µm, particularly preferably between 3 µm and 5 µm.

[0065] Alternatively, the back of the security element 10, in particular the security thread 10a, 10b, can also be printed with a magnetic printing ink M1, M2, M3. In this case, too, larger areas can typically be realized compared to the micro-recesses 17, ensuring reliable coding and machine readability.

[0066] In particular, it has been found that magnetic printing inks with magnetic pigments having a core coated with silver or a silver compound are barely visible or not visible at all on the front side of the security element 10 in incident light or when viewed from above if they have been applied to the back side of the security element 10. Therefore, such applied magnetic printing inks do not necessarily have to be covered or otherwise concealed on the visible side in order to largely avoid visually disruptive influences, in particular on any visual security features present.

[0067] Fig. 4 shows a further embodiment of the security element 10, which has an optically variable security feature by means of an optical relief structure 11 and image elements 16 analogous to the one shown in Fig. 3 illustrated embodiment. In this regard, reference is made to the previous description with reference to Fig. 3 described.

[0068] The embodiment of the Fig. 4 comprises a functional layer formed as an opaque cover layer 19 of the magnetic printing ink M3 and defining at least one further, relatively large-area code area C3 of the magnetic coding. Accordingly, the magnetic printing ink M3 preferably comprises magnetic pigments whose diameters are between 2 µm and 10 µm, particularly preferably between 3 µm and 5 µm.

[0069] The opaque top layer 19 of the Fig. 4 forms a color layer with recesses 20 in the form of a negative print (clear text), which is particularly clearly visible when viewed in transmitted light.

[0070] It is understood that the more magnetic printing inks M1, M2, and M3 used, and the more complex the shapes of the code areas C1, C2, and C3, or the partial areas within the individual code areas C1, C2, and C3 that are each coated with a magnetic printing ink M1, M2, and M3 or a mixture of magnetic printing inks M1, M2, and M3, the more difficult the machine-readable, magnetic codes become to counterfeit. Increasing the number of code areas C1, C2, and C3 also increases counterfeit security.

[0071] Figures 5 to 8 show various, essentially rectangular security elements 10 with strip-shaped code areas C1, C2 in plan view. The code areas C1, C2 are visible in plan view and form part of a visual or visually verifiable security feature.

[0072] Fig. 5shows a simple design with two code areas C1, C2, which extend as strips 24 across the entire length of the security element 10 and are separated from each other by an unprinted area 22 located therebetween. For example, the code areas C1, C2 implement a HiCoLoCo coding, in which the magnetic pigments of the magnetic printing ink M1 of the code area C1 have a higher coercivity than the magnetic pigments of the magnetic printing ink M2 that are incorporated or applied in the code area C2.

[0073] Fig. 6 shows a security element 10 with two parallel stripes 24, which are alternately printed with magnetic printing inks M1, M2, thus defining alternating code areas C1, C2. The two parallel longitudinal stripes 24 are separated from each other by the unprinted area 22.

[0074] At the Fig. 7In the embodiment shown, the security element 10 is strip-shaped and printed in the longitudinal direction alternately with magnetic printing inks M1, M2 such that essentially rectangular code areas C1, C2 of different sizes are formed, which are spaced from one another by unprinted areas 22.

[0075] The term "unprinted" is to be interpreted to mean that at least no magnetic printing inks M1, M2, M3 or their pigments are incorporated or applied in the unprinted area 22.

[0076] Fig. 8 shows one of the Fig. 7 similar design in which the code areas C1, C2 are designed as diagonal stripes.

[0077] Figs. 9 and 10 show further security elements 10, which are visible in plan view as circular structures. When executing the Fig. 9the code areas C1, C2 are designed as concentric circular rings arranged around a central unprinted area 22. Fig. 10 shows a circular security element 10 with strip-shaped code areas C1, C2, which are arranged parallel to each other and spaced apart from each other on the visible side.

[0078] Fig. 11 shows a security element 10 with a hexagonal appearance in plan view. The code areas C1, C2, which have magnetic printing inks M1, M2, are designed as diagonal stripes.

[0079] Fig. 12 shows a substantially square security element 10 with code areas C1, C2, which are separated from each other by a cross-shaped unprinted area 22.

[0080] Fig. 13 shows a security element 10 in plan view, in which two strip-shaped code areas C1, C2 overlap in an overlap section 26.

[0081] Fig. 14a to 14dshow exemplary code areas C1, C2 of security elements 10 which are unevenly printed with magnetic printing inks M1, M2 or in which the magnetic printing inks M1, M2 are incorporated or applied in variable layer thickness.

[0082] Fig. 14e shows an embodiment with two code areas C1, C2, which are unevenly printed with magnetic printing inks M1, M2 and overlap in the overlap area 26.

[0083] In a method for producing the security element, the magnetic coding is generated by printing. At least two opaque magnetic printing inks M1, M2, M3, each containing different magnetic pigments, are incorporated or applied in defined code areas C1, C2, C3 of the security element 10 (see FIG. Fig. 3 to 14 ), in such a way that they provide at least part of a visual security feature.

[0084] For this purpose, the micro-cavities 17 of a moiré magnifier can be filled with magnetic printing inks M1, M2, as in particular the Figures 3 and 4illustrate. Alternatively, the magnetic printing inks M1, M2, M3 or their magnetic pigments are introduced or applied into the code areas C1, C2, C3 in such a way that they are not visible, at least when viewed from above, onto the security element 10. The invention is explained above by way of example with reference to the drawings, which illustrate specific exemplary embodiments of the invention. These exemplary embodiments are described in detail above and enable those skilled in the art to technically implement the invention. The described embodiments do not exclude one another, but rather complement one another. Furthermore, the position or arrangement of individual elements or steps within the described embodiments can of course be modified without deviating from the subject matter of the invention.Therefore, the description of the accompanying figures is not to be interpreted in a limiting sense, since the scope of the invention is defined exclusively by the appended claims.

Claims

1. Security element (10), preferably in the form of a foil strip (10c), foil thread (10a, 10b), or foil patch (10d), with a machine-readable code, characterized in that the machine-readable code is a printed magnetic coding which is produced using at least two opaque magnetic printing inks (M1, M2, M3), each containing different magnetic pigments, which differ in terms of their coloring and / or magnetic properties and are inserted or applied in defined code areas (C1, C2, C3) of the security element (10), wherein the magnetic printing inks (M1, M2, M3) inserted or applied in the code areas (C1, C2, C3) provide at least part of a visual security feature visible when viewing the security element (10) in plan-view.

2. Security element (10) of claim 1, characterized in that the at least two magnetic printing inks (M1, M2, M3) correspond to the same color and differ with regard to their magnetic properties, in particular with regard to their coercivity.

3. Security element (10) of claim 1, characterized in that the at least two magnetic printing inks (M1, M2, M3) correspond to different colors and do not differ with regard to their magnetic properties, in particular with regard to their coercivity.

4. Security element (10) of any one of the preceding claims, characterized in that the visual security feature is an optically variable security feature which has a visual appearance which is dependent on the viewing angle and which is defined at least in part by at least one of the magnetic printing inks (M1, M2, M3) introduced or applied.

5. Security element (10) of claim 4, characterized in that the optically variable security feature comprises a micro-optical relief structure (11), in particular a microlens arrangement, wherein at least one of the magnetic printing inks (M1, M2, M3) introduced into or applied to the code areas (C1, C2, C3) is covered by the micro-optical relief structure (11).

6. Security element (10) of claim 4 or 5, characterized in that the optically variable security feature comprises a moiré magnifier.

7. Security element (10) of any one of the preceding claims, characterized in that the at least two magnetic printing inks (M1, M2, M3) are introduced into micro-recesses (17) which are embossed in a transparent or translucent image layer (13) of the security element (10).

8. Security element (10) of claim 7, characterized in that the magnetic pigments of the magnetic printing inks (M1, M2, M3) introduced into the micro-recesses (17) comprise a diameter of less than 2 µm.

9. Security element (10) of any one of the preceding claims, characterized in that an opaque cover layer (19) of the security element is printed with the at least two magnetic printing inks (M1, M2, M3) over at least some areas or is formed as an ink layer of at least one of the magnetic printing inks (M1, M2, M3).

10. Security element (10) of claim 9, characterized in that the magnetic pigments of the at least two magnetic printing inks (M1, M2, M3), with which the opaque cover layer (19) is printed or by means of which the opaque cover layer (19) is formed, have a diameter of between 22 µm and 10 2 µm, preferably between 3 2 µm and 5 2 µm.

11. Security element (10) of any one of the preceding claims, characterized in that the magnetic pigments of the at least two magnetic printing inks (M1, M2, M3) comprise a magnetized or magnetizable core which is coated by an opaque dye preferably containing silver or a silver compound.

12. Security element (10) of any one of the preceding claims, characterized in that at least one of the magnetic printing inks (M1, M2) is incorporated or applied in a variable layer thickness in one of the code areas (C1, C2).

13. Security element (10) of any one of the preceding claims, characterized in that at least two of the code areas (C1, C2, C3), in which the at least two magnetic printing inks (M1, M2, M3) are introduced or applied, are designed as areas spaced apart from one another in plan view and / or are arranged so as to overlap one another in plan view.

14. Value document (100), comprising at least one security element (10) of any one of the preceding claims.

15. Method for producing a security element (10) of any one of claims 1 to 13, characterized in that the magnetic coding is produced by printing in that the at least two opaque magnetic printing inks (M1, M2, M3), each containing different magnetic pigments, are introduced or applied in defined code areas (C1, C2, C3) of the security element (10) in such a way that they provide at least part of a visual security feature (10).