EP4000942A1 - Security element having machine readable security features - Google Patents

Abstract

In the case of a security element with machine-readable security features in the form of magnetic materials of different coercivity, which are present in several printing inks in several areas of the same and/or different remanence on a carrier substrate, each area being formed from a printing ink that comprises at least one magnetic material that is selected is made of magnetic materials which have the coercive field strength K1, K2 or K3, at least three different areas are provided, which are formed by printing inks that are different from one another, with at least two printing colors of the printing colors of the at least three areas only being used one of the magnetic materials, which have the coercivity K1, K2 or K3, and wherein at least one printing ink comprises a mixture of at least two magnetic materials which have the coercivity K1, K2 or K3. The security element is difficult to reproduce but allows easy verification of authenticity.

Description

The invention relates to a security element with machine-readable security features in the form of magnetic materials with different coercive field strengths, which are present in several printing inks in several areas of the same and/or different remanence on a carrier substrate, and a data carrier or a document of value that has such a security element.

Data carriers, valuable and identification documents, but also other valuables, such as branded items, are often provided with security elements for protection, which allow their authenticity to be checked and at the same time serve as protection against unauthorized imitation. Such security elements are often designed in the form of a security thread, which can be fully or partially embedded in a material of the data carrier, value document or article, for example the paper of a bank note.

In order to enable an automatic authenticity check, security elements are also often provided with machine-readable codes whose information content can be recorded and evaluated.

Security threads or security strips containing magnetic material are known from the prior art. The magnetic material can be applied continuously or only in certain areas, for example in the form of a code. A sequence of magnetic and non-magnetic areas that is characteristic of the respective protected object is generally used for magnetic coding.

It is also known to use different magnetic materials, e.g. with different coercive field strengths, for a magnetic coding.

the EP 0310707 A2 describes a document with magnetically detectable security features, which areas with variable magnetic intensity which is obtained by changing the layer thickness or the concentration of the magnetic material.

the WO 2006/042667 A1 describes security elements that have at least two magnetic materials, the magnetic materials having different coercive field strengths. The materials are arranged on and/or in the security element in such a way that their remanence is the same.

From the WO 2009/090676 A1 a security element is known, on the substrate of which at least two magnetic areas with different coercivity and the same or different remanence are applied. The magnetic areas are arranged in such a way that they can generate at least three different codes.

In the known configurations of a security element, however, the amount of information contained in the machine-readable code is still relatively limited, or increasing the amount of information requires magnetic areas with a complex design, the production of which requires a great deal of effort.

The object of the invention is therefore to further increase the information content of the magnetic security element and/or to increase its security against forgery. At the same time, the production of the magnetic areas and their printing should be relatively simple and inexpensive. Furthermore, a data carrier or document of value, in particular a banknote, is to be provided, the authenticity of which can be checked easily, but which is difficult to reproduce.

This object is solved by the features of the independent claims. Developments of the invention are the subject matter of the dependent claims.

According to the invention, in a generic security element with machine-readable security features in the form of magnetic materials of different coercivity, which are present in several printing inks in several areas of the same and/or different remanence on a carrier substrate, each area consisting of one printing ink is formed, which comprises at least one magnetic material that is selected from magnetic materials that have the coercivity K1, K2 or K3, at least three different areas are provided, which are formed by printing colors that are different from one another,
wherein of the printing inks of the at least three areas, at least two printing inks each comprise only one of the magnetic materials that have the coercive field strength K1, K2 or K3, and wherein at least one printing ink is a mixture of at least two magnetic materials that have the coercive field strength K1, K2 or Have K3 includes.

• K1 - K2 - K1/K2
• K1 - K2 - K1/K3
• K1 - K2 - K2/K3
• K1 - K3 - K1/K3
• K1 - K3 - K1/K2
• K1 - K3 - K2/K3
• K2 - K3 - K1/K2
• K2 - K3 - K2/K3
• K2 - K3 - K1/K3
• K2 - K3 - K1/K2/K3
• K1 - K3 - K1/K2/K3
• K1 - K2 - K1/K2/K3
• K1 - K2 - K3 - K1/K2
• K1 - K2 - K3 -K1/K3
• K1 - K2 - K3 -K2/K3
• K1 - K2 - K3 - K1/K2/K3

The security element according to the invention can, for example, have the following configurations of the at least three (i.e. also 4 and more) different areas X - Y - Z, with the details K1, K2 and K3 standing for the coercive field strength of the magnetic material(s), that is/are covered by the printing color or the respective area and the indication of K1/K2 etc. stands for the mixture of the magnetic materials, which is covered by the printing color of the respective area:

• K1 - K2 - K1/K2
• K1 - K2 - K1/K3
• K1 - K2 - K2/K3
• K1 - K3 - K1/K3
• K1 - K3 - K1/K2
• K1 - K3 - K2/K3
• K2 - K3 - K1/K2
• K2 - K3 - K2/K3
• K2 - K3 - K1/K3
• K2 - K3 - K1/K2/K3
• K1 - K3 - K1/K2/K3
• K1 - K2 - K1/K2/K3
• K1 - K2 - K3 - K1/K2
• K1-K2-K3-K1/K3
• K1 - K2 - K3 - K2/K3
• K1 - K2 - K3 - K1/K2/K3

Preferably, the coercive field strength K1 is 3500 Oe ± 30%, preferably ± 20%, more preferably ± 10%, the coercive field strength K2 is 250 Oe ± 30%, preferably ± 20%, more preferably ± 10%, and the coercive field strength K3 is 1000 Oe ± 30 %, preferably ± 20%, more preferably ± 10%.

Materials >1500 Oe are typically high coercivity magnetic materials and low coercivity magnetic materials are generally understood to be materials having a coercivity <500 Oe.

The magnetic materials with the coercive field strengths K1, K2 and K3 are selected in such a way that complete magnetization (saturation) can be achieved (usually a 3-fold stronger magnetic field is required for this, with the maximum possible field strength being around 15,000 Oe) , but there is no mutual influence.

According to a preferred embodiment, at least one area A is provided with an ink that includes magnetic material that exclusively has a coercive field strength K1, at least one area B with an ink that includes magnetic material that exclusively has a coercive field strength K2, and at least one area C with an ink comprising a mixture of two magnetic materials with coercivity K1 and K2, where the coercivity K1 is 3500 ± 300 Oe and the coercivity K2 is 275 ± 25 Oe.

1. (a) mindestens ein Bereich A mit einer Druckfarbe vorgesehen, die magnetisches Material umfasst, das ausschließlich eine Koerzitivfeldstärke K1 aufweist, und/oder mindestens ein Bereich B mit einer Druckfarbe, die magnetisches Material umfasst, das ausschließlich eine Koerzitivfeldstärke K2 aufweist, und/oder mindestens ein Bereich D mit einer Druckfarbe, die magnetisches Material umfasst, das ausschließlich eine Koerzitivfeldstärke K3 aufweist, und
2. (b) mindestens ein Bereich C mit einer Druckfarbe vorgesehen, die eine Mischung von mindestens zwei der magnetischen Materialien mit den Koerzitivfeldstärken K1, K2 und K3 umfasst,

wobei die Koerzitivfeldstärke K1 3500 ± 300 Oe beträgt, die Koerzitivfeldstärke K2 275 ± 25 Oe beträgt und die Koerzitivfeldstärke K3 1000 ± 100 Oe beträgt.According to a further preferred embodiment

1. (a) at least one area A is provided with an ink that includes magnetic material that exclusively has a coercive field strength K1, and/or at least one area B with an ink that includes magnetic material that exclusively has a coercive field strength K2, and/or at least one area D with an ink that comprises magnetic material that exclusively has a coercivity K3, and
2. (b) at least one area C is provided with a printing ink which comprises a mixture of at least two of the magnetic materials with the coercive field strengths K1, K2 and K3,

where the coercivity K1 is 3500 ± 300 Oe, the coercivity K2 is 275 ± 25 Oe, and the coercivity K3 is 1000 ± 100 Oe.

Flexible plastic foils, also called carrier foils, are preferably used as carrier substrates. This can be, for example, PI (polyimide), PP (polypropylene), MOPP (monoaxially stretched polypropylene), PE (polyethylene), PPS (polyphenylene sulfide), PEEK (polyetheretherketone), PEK (polyetherketone), PEI (polyetherimide), PSU ( Polysulfone), PAEK (polyaryletherketone), LCP (liquid crystal polymers), PEN (polyethylene naphthalate), PBT (polybutylene terephthalate), PET (polyethylene terephthalate), PA (polyamide), PC (polycarbonate), COC (cyclo-olefin copolymers) , POM (polyoxymethylene), ABS (acrylonitrile butadiene styrene), PVC (polyvinyl chloride), PTFE (polytetrafluoroethylene), ETFE (ethylene tetrafluoroethylene), PFA (tetrafluoroethylene perfluoropropyl vinyl ether fluorocopolymer), MFA (tetrafluoromethylene perfluoropropyl vinyl ether fluorocopolymer), PVF ( polyvinyl fluoride), PVDF (polyvinylidene fluoride), and EFEP (ethylene tetrafluoroethylene hexafluoropropylene fluoroterpolymer) and/or mixtures and/or copolymers of these materials. The carrier films can be transparent, translucent, semi-opaque or opaque. The carrier substrate is preferably made from at least one of these materials.

The thickness of the carrier substrate can be 5-700 μm, preferably 5-200 μm, particularly preferably 5-50 μm.

Furthermore, coextruded or chemically or physically pretreated plastic films, for example acrylate-coated plastic films, can also be used as carrier substrate.

According to another embodiment, metal foils can serve as the carrier substrate, for example Al, Cu, Sn, Ni, Fe or stainless steel foils with a thickness of 5-200 μm, preferably 10-80 μm, particularly preferably 20-50 μm. The foils can be surface-treated, coated or laminated, for example with plastics, or painted.

Paper or composites with paper, for example composites of paper with plastics with a basis weight of 20-500 g/m ² , preferably 40-200 g/m ² , are also suitable as carrier substrates.

The carrier substrate can optionally be coated with an adhesion promoter.

The security features according to the invention can be applied to the carrier substrate in order to form a security element. This security element can then be made up and at least partially embedded as a strip, thread or patch in a data carrier or a document of value or applied to it.

It is also possible to design the security element as a transfer element, in which case the carrier substrate can be removed after application to the data carrier or the document of value. To make it easier to pull off the carrier substrate, a release layer can be provided on the carrier substrate and under the layer structure present on the carrier substrate.

Alternatively, the security features can also be generated directly on the data carrier or the document of value by the printing inks of the at least three different areas being printed at a predetermined location on the data carrier or document of value.

In a preferred embodiment, more than two of the areas formed by inks comprising only one of the magnetic materials having the coercivity K1, K2 or K3 are provided and/or the area formed by an ink comprising a mixture of at least two magnetic materials which have the coercivity K1, K2 or K3, more than one is provided.

Although each of the at least three different areas already allows coding on several levels, a further increase in the information content can be advantageous, for example for reasons of security, which is achieved by further areas.

Magnetic materials are preferably only present in the security element in the at least three different areas.

According to a further embodiment, the mixing ratio of the magnetic materials in the areas formed by a printing ink comprising a mixture of at least two magnetic materials having the coercivity K1, K2 or K3 is identical and/or different, preferably in all of these areas identical.

If only a single printing ink with a defined mixing ratio of K1, K2 and/or K3 is used, this has the advantage of being simple and inexpensive to manufacture, since there are no printing inks when using a single printing ink for this area, compared to the overprinting of several printing inks Production fluctuations can have an impact. In addition, the same ink can be used to feed multiple printing cylinders.

To improve security, however, several different printing inks can also be used for this area, with different printing inks each having different mixing ratios of the magnetic materials with the coercive field strengths K1, K2 and/or K3.

The mixing ratio of the magnetic materials in the areas formed by a printing ink that comprises a mixture of at least two magnetic materials that have the coercivity K1, K2 or K3 is selected from 20:1 to 1:20 in one embodiment.

In a further embodiment, the printing inks that form the areas have the same and/or different layer thicknesses.

Magnetic materials or printing inks applied with different thicknesses cause different signal strengths, which means that the machine-readable coding can be expanded by an additional level.

Since the mixing ratio of the magnetic materials with the coercive field strengths K1, K2 and K3 remains constant during printing, regardless of the thickness of the ink applied, magnetic areas of different remanence also arise with the same ratio of the coercive field strengths to one another if the ink of area C is applied in different thicknesses.

An increase in the information content of the magnetic coding by achieving a different signal strength is achieved in the security element according to the invention in a further preferred embodiment of the invention in that at least one printing color is provided in the form of a grid.

According to a preferred embodiment, at least one printing color is provided as a halftone screen, preferably different halftone screens are provided.

Halftoning is a well-known technology in the field of printing. A grid essentially consists of a large number of small dots that are applied to the printing surface in a certain size and frequency. In the case of a full tone screen, the entire area of the screen is printed evenly, in the case of a halftone screen the area is only partially covered.

In practice, screens are produced with a screen roller known to those skilled in the art, in whose surface depressions, so-called cells, of a specific shape and depth are engraved, which are separated by webs and which absorb the printing ink.

A grid can, for example, also be designed such that the magnetic area C consists of a plurality of parallel magnetic tracks extending in the longitudinal direction with empty tracks in between, the magnetic tracks of different areas each having different dimensions in the transverse direction.

In another embodiment of the invention, at least one ink differs from the other inks in its concentration of magnetic material(s).

Due to the different concentrations, the magnetic areas are equipped with different remanences or signal strengths and can thus contribute to an increase in the information content of the magnetic coding.

In principle, the same or a different remanence of the areas can be provided in all of these embodiments. In order to achieve the same signal intensity or remanence, however, the thickness/raster/concentration of the magnetic material/materials or the printing ink must be selected accordingly.

The printing inks, and thus the respective magnetic areas, can be arranged directly adjacent to one another and/or spaced apart.

In one embodiment variant, it is provided that areas that are adjacent to one another, i.e. that border one another, are constructed using different printing inks.

In a further embodiment variant, the magnetic areas are applied at a distance from one another.

However, it can also be advantageous to apply several of the same inks with different thicknesses or several different inks (of the same and/or different thicknesses) and thus several areas directly adjacent to one another in the lateral direction, whereby a Magnetic area group is created. A plurality of magnetic area groups themselves can again be spaced apart, preferably equally spaced apart, or arranged adjacent to one another on the carrier substrate.

Provision can also be made for the printing inks of a group of magnetic areas to have different thicknesses, with the thicknesses preferably increasing or decreasing from one side of the group of magnetic areas to the opposite side.

The combination with a raster is also possible, whereby the print colors of a magnetic area group are characterized by a different raster, i.e. several identical print colors with different rasters or several different print colors with the same and/or different rasters.

However, the rastering also represents an advantageous possibility of providing a magnetic security code for data carriers or documents of value on its own, ie independently of other forms of formation of areas with individual magnetic materials, as described above. According to a further, independent aspect of the invention, one or more identical and/or different forms of screening, e.g Mixtures that can have the same or different mixing ratios of the at least two magnetic materials can be used to form magnetic areas for a security element with machine-readable security features in the form of magnetic materials. The coercivity of the magnetic materials used for the grid(s) can be the same or different, depending on how extensive the magnetic coding is to be designed. Variants with different thicknesses of the printing ink(s) used for the screening and developments in the form of magnetic area groups and their variants, as described above, are also possible. The coercivity of the In addition, magnetic materials in this aspect are not limited to K1, K2 and K3 but can also have a value other than K1, K2 or K3.

In particular, the screening can be used, for example, in a variant in which at least two printing inks, each with different mixing ratios of the magnetic materials, are provided in at least two areas on a carrier substrate with the same and/or different thicknesses. In this case, the screening can be used for at least one of the at least two printing colors or additionally in a further printing color.

Furthermore, the screening can advantageously be used in a variant in which several identical and/or different printing inks (different printing inks: printing inks with different mixing ratios of the at least two magnetic materials of different coercivity) of different thicknesses are arranged directly adjacent to one another on a carrier substrate and such a magnetic area group form. Here, too, the screening can be used for one or more printing colors of the magnetic area group and alternatively also in a printing color that is separate or independent of the magnetic area group.

However, the screening as such can also be combined with and/or provided in addition to one or more magnetic area groups formed by different printing inks of the same thickness.

In the same way, the concentration of magnetic material/materials in the printing ink can be used to create different magnetic characteristics. The different concentration can also be used in a variant in which at least two printing inks, each with different mixing ratios of the magnetic materials, are provided in at least two areas on a carrier substrate with the same and/or different thickness. The concentration difference can in this case for at least one of the at least two printing colors or an additional printing color can be used.

The concentration difference in the printing ink can also be used as a feature of the magnetic code in the variant in which several identical and/or different printing inks of different thicknesses are arranged directly adjacent to one another on a carrier substrate and thus form a magnetic area group. As with screening, the different concentration of magnetic material(s) can be used for one or more magnetic domain group inks, and alternatively in a separate or independent ink from the magnetic domain group, and with one or more magnetic domain groups made up of different inks of the same thickness are formed, combined and/or provided in addition thereto.

According to the individual aspects of the invention, the security element can have further layers with security features in another embodiment. For example, an opaque layer in the form of a reflective layer or a printed layer, for example a colored, black, or white printed layer, can be provided on the carrier substrate below and/or above the magnetic layer areas, which can be applied over the entire area or partially.

In this context, a reflective layer is understood to mean, for example, a metallic layer made of Al, Cu, Ag, Au, Pd, Pt, Sn, In or their alloys and the like, which is produced by PVD or CVD processes, by sputtering, electron beam evaporation or the like can be upset. A reflective layer is also understood to mean, for example, a layer that appears metallic, such as a paint or printing ink layer that contains metallic pigments or flakes, or pigments or flakes of metal compounds, such as metal oxides. These layers are preferably applied by known printing methods, by doctoring or brushing.

In addition, the reflective layer can also be an HRI (High Refractive Index) layer. Such HRI layers have, for example, dielectric materials with a refractive index greater than or equal to 1.65, for example zinc sulfide (ZnS), zinc oxide (ZnO), titanium dioxide (TiO ₂ ), carbon (C), indium oxide (In ₂ O ₃ ), Indium tin oxide (ITO), tantalum pentoxide (Ta ₂ O ₅ ), cerium oxide (CeO ₂ ), yttrium oxide (Y ₂ O ₃ ), europium oxide (Eu ₂ O ₃ ), iron oxides such as iron(II,III) oxide (Fe ₃ O ₄ ) and ferric oxide (Fe ₂ O ₃ ), hafnium nitride (HfN), hafnium carbide (HfC), hafnium oxide (HfO ₂ ), lanthanum oxide (La ₂ O ₃ ), magnesium oxide (MgO), neodymium oxide ( Nd ₂ O ₃ ), praseodymium oxide (Pr ₆ O ₁₁ ), samarium oxide (Sm ₂ O ₃ ), antimony trioxide (Sb ₂ O ₃ ), silicon carbide (SiC), silicon nitride (Si ₃ N ₄ ), silicon monoxide (SiO), selenium trioxide ( Se ₂ O ₃ ), tin oxide (SnO ₂ ), tungsten trioxide (WO ₃ ), high-index organic monomers and/or high-index organic polymers. These materials can be either evaporated or printed (especially the monomers and polymers).

A partially applied reflective layer or a printed layer can preferably have gaps in the form of letters, numbers, patterns, characters, symbols, lines and the like.

The gaps in the reflective layer are preferably arranged in such a way that they lie in the regions free of the magnetic layer. On the one hand, this visually covers the magnetic layer areas so that they are not recognizable even when viewed in transmitted light, and on the other hand, the gaps in the metallic or metallic-appearing layer or the printed layer that can be seen in transmitted light create an additional security feature.

Such a reflective layer can alternatively be provided on the side of the carrier substrate opposite the magnetic areas or on both sides of the carrier substrate.

In the event that the reflective layer is provided on the same side of the carrier substrate below and/or above the magnetic areas, it may be expedient to provide a protective layer between this layer and the magnetic areas in order to prevent mutual influencing of the to prevent magnetic layer and the metallic layer. The protective layer prevents, for example, corrosion phenomena, especially when the security element is exposed to moisture, especially when the layer is metallic or contains metallic pigments or flakes.

This protective layer can be designed as a thin film, but also as a protective lacquer layer.

Furthermore, optically variable security features can also be present on the carrier substrate or in the layer structure, for example diffractive structures such as surface reliefs, holograms, diffraction gratings and the like, or also layers that have a viewing angle-dependent color change effect. Such security features with viewing angle-dependent color change effects are formed, for example, by thin-film elements that have a reflection layer, a dielectric spacer layer and an absorber layer, or by cholesteric liquid-crystal layers combined with a dark, preferably black, printed layer or metallization. However, print layers with interference pigments or liquid-crystalline pigments can also be used to produce a layer with a color change effect that is dependent on the viewing angle.

Furthermore, the security element can optionally have further colored, black, gray or white printed layers.

All of these security features can be applied over the whole area or partially on one or both sides of the carrier substrate. The security features can be applied with register and/or register accuracy, for example to the magnetic areas.

The term register-accurate or register-accurate is understood to mean a defined position of the features relative to one another.

These security features can also be applied in such a way that they lie at least partially in the regions free of the magnetic layer or at least partially cover them.

The additional security features can also be provided on a second carrier substrate and connected to the layer structure on which the magnetic areas lie by lamination or lining. If necessary, the second carrier substrate can then be pulled off.

The security element can expediently be provided with a protective lacquer layer on one and/or both sides in order to protect the security features present on the security element against mechanical, physical and/or chemical influences.

The protective lacquer layer can, for example, be based on nitrocellulose, acrylates and their copolymers, polyamides and their copolymers, polyvinyl chloride and their copolymers or consist of a crosslinking lacquer.

Furthermore, the security element can be provided with an adhesive layer on one or both sides in order to enable it to be fixed on or in a data carrier or document of value. This adhesive layer can be in the form of either a heat seal, cold seal, or self-adhesive coating.

The protective lacquer layer and/or the adhesive layer can also be pigmented, with all known pigments or dyes, for example TiO ₂ , ZnS, kaolin, ATO, FTO, aluminum, chromium and silicon oxides or, for example, organic pigments such as phthalocyanine blue, i-indolide yellow, dioxazine violet and the like can be used. Furthermore, luminescent dyes or pigments which fluoresce or phosphorescent in the visible, UV or IR range, effect pigments such as liquid crystals, pearlescent, bronzes and/or multilayer color change pigments and heat-sensitive colors or pigments can be added. These can be used in all possible combinations. In addition, luminescent pigments can also be used alone or in combination with other dyes and/or pigments.

The invention also relates to a data carrier or a document of value which has a security element according to an aspect as described above, wherein the security element is preferably at least partially embedded in the data carrier or in the document of value or applied to the data carrier or the document of value in the form of a thread, strip or patch.

• Fig. 1 eine Ausführungsform eines erfindungsgemäßen Sicherheitselements in schematischer Darstellung
• Fig. 2 eine andere Ausführungsform eines erfindungsgemäßen Sicherheitselements in schematischer Darstellung,
• Fig. 3 eine weitere Ausführungsform eines erfindungsgemäßen Sicherheitselements in schematischer Darstellung,
• Fig. 4 eine alternative Ausführungsform eines erfindungsgemäßen Sicherheitselements in schematischer Darstellung,
• Fig. 5 in schematischer Darstellung eine Ausgestaltung eines erfindungsgemäßen Sicherheitselements in Form eines Sicherheitsfadens und
• Fig. 6 in schematischer Darstellung eine alternative Gestaltung eines erfindungsgemäßen Sicherheitselements in Form eines Sicherheitsfadens zeigen.

The invention is explained in more detail below with reference to the drawing, in which

• 1 an embodiment of a security element according to the invention in a schematic representation
• 2 another embodiment of a security element according to the invention in a schematic representation,
• 3 a further embodiment of a security element according to the invention in a schematic representation,
• 4 an alternative embodiment of a security element according to the invention in a schematic representation,
• figure 5 a schematic representation of an embodiment of a security element according to the invention in the form of a security thread and
• 6 show a schematic representation of an alternative design of a security element according to the invention in the form of a security thread.

In the 1 The illustrated embodiment shows a security element comprising a carrier substrate 1 on which magnetic regions A, B and C which are equally spaced from one another are applied.

The two magnetic areas A are formed by a printing ink that includes magnetic material that exclusively has a coercivity K1 (shown hatched). The magnetic area B in turn is formed by an ink comprising magnetic material that exclusively has a coercivity K2 (marked with "+" symbols). Between one of the two areas A and area B is a magnetic area C formed by an ink comprising a mixture of two magnetic materials with coercive forces K1 and K2, where K1 is for example 3500 ± 300 Oe and K2 275 ± 25 Oe is.

To clarify the mixing ratio and to better distinguish between areas A and B, the magnetic materials with the coercive field strengths K1 and K2 of area C are shown separately from each other, but it should be understood that these two magnetic materials are mixed homogeneously and in the entire area C be present in a defined mixing ratio.

In the embodiment of 1 all magnetic areas have the same width and also have the same thickness.

In 2 is a to 1 shown analogous embodiment, in which instead of a second area A, a second area C is provided which has a different mixing ratio of the materials with the coercivity K1 and K2 than the first area C. In contrast to the embodiment of FIG 1 the magnetic areas A, B and C are not all equally spaced, but have different widths of magnet (layer)-free zones between each other. The thicknesses of the inks forming the areas A, B and C also vary among themselves. As a result, different remanences are formed in the individual magnetic areas.

However, it is also possible to leave the distance between the areas A, B and C and the thickness of the magnetic areas the same in the entire security element or only in parts of it.

According to another embodiment (not shown), in addition to the areas A and B, at least one area D can also be provided, which is formed by a printing ink that includes magnetic material with a coercivity K3. In this embodiment, the coercive forces K1, K2 and K3 are preferably 3500 ± 300 Oe, 275 ± 25 Oe and 1000 ± 100 Oe. Regarding the training of area D, eg in relation on thickness and width or distance, the same options are available as for areas A and B.

The most diverse combinations of magnetic areas or printing inks are possible, whereby these can differ e.g. in terms of width, thickness, number, remanence, distance, etc.

According to the 3 In the illustrated embodiment, areas A, B and C are provided adjacent to each other to form a group of magnetic areas, the areas within the group differing in width and the inks of the three areas also differing in thickness. A single area A is shown next to the magnetic area group, but several individual areas A, B and/or C or just further magnetic area groups can also be provided. Likewise, one or more areas D can be provided as part of the magnetic area group(s) or as an additional area(s), with these areas being e.g. in terms of thickness and width or distance like areas A and B can be trained.

4 shows an embodiment of a security element in which two different designs of magnetic area groups are shown, which can be used both independently and together as a security feature or with other magnetic area groups or magnetic areas. In the magnetic region group shown on the left, only regions C are provided, each having the same mixing ratio and the same width but different layer thicknesses showing a stepwise, continuous increase or decrease in one direction. Alternatively, the thicknesses of the printing inks of the individual areas C can be designed in such a way that the increase or decrease takes place in a running manner. All or individual areas C can also have different mixing ratios.

In contrast to the group of magnetic areas on the left, the group of magnetic areas on the right, which also shows a gradual progression of the individual areas, includes not only printing inks from a specific magnetic area but also different areas A, B and C, which also have different widths. Likewise, the individual areas can be designed without an increasing or decreasing course and/or with different widths. Likewise, instead of or in addition to the areas A and/or B, an area D is possible.

in the in 4 In the illustrated embodiment, the security element has a carrier substrate 1 provided with a partial metal layer, on which a protective layer 2 and then a reflective layer 3 with gaps 4 are applied. If necessary, the protective layer 2 prevents the magnetic layer and the reflective layer from influencing one another, for example due to corrosion, when the security element is exposed to moisture. Instead of a protective layer of paint, a thin polymeric protective film can also be used, which is connected to the structure using a laminating adhesive.

The magnetic-area groups are arranged in register with the reflective areas, and areas without a magnetic layer are provided in register with the gaps 4 in the reflective layer 3 . A printing ink 5 is also applied in register with the magnetic areas and the reflective layer 3 on each of the groups of magnetic areas. The printing ink 5 can be a colored printing layer, but it is preferably a printing ink with metallic pigments, e.g. an ink with Al flakes, or a second vapor-deposited reflective layer.

Alternatively, instead of the reflective layer 3, a black, white or colored printed layer can be provided. Instead of the metallic carrier substrate 1 and the protective layer 2, a transparent, semi-transparent or opaque plastic film can also be provided. In another, In an embodiment that is not shown, the reflective layer 3 (or the printed layer) with gaps 4 can also be provided on the side of the carrier substrate 1 opposite the magnetic areas or groups of magnetic areas. The gaps 4 can be designed in the form of letters, numbers, characters, patterns, symbols or lines and in this way form additional security features of the security element. The security element can also be provided with an adhesive layer on one side or on both sides in order to improve anchoring in a document of value.

In addition, the security element can have additional security features, for example a thin-layer element with a color-shift effect or a lacquer layer with a diffractive structure. Such elements and their construction are known in the art.

figure 5 shows an exemplary design of a security thread 6, in which the magnetic areas A, B, C of the magnetic coding not only have the same length and thickness, but also each take up the entire width of the security thread 6. However, the two areas C differ in the grid and therefore, despite the same width, have a different amount of magnetic material in the transverse direction. While the areas A and B cover the entire surface, the magnetic areas C each consist of a plurality of parallel tracks 7 extending in the longitudinal direction of the printing ink of the area C comprising the magnetic material with the coercive field strengths K1 and K2 Areas C contain a smaller amount of empty webs than areas A and B.

Instead of or in addition to the areas A and/or B, at least one area D can also be provided here. It is also possible that the printing ink of one of the areas C is not a mixture of the magnetic materials with the coercive field strengths K1 and K2 but of the materials with the coercive field strengths K1 and K3 or K2 and K3 or even K1 + K2 + K3.

in the in 6 shown embodiment of the security thread 6 is an alternative form of grid shown. The ink of area C is shown here schematically as a halftone screen. In this case, in certain areas of the anilox roller or the printing cylinder, no cells are provided for receiving ink, as a result of which the printed surface is only partially covered with ink.

Such a full tone/halftone screen can also be combined with an amplitude-modulated screen known in the art, for example in order to be able to better represent color gradients. With an amplitude modulated screen, the size of the screen dots varies and in this way produces different tonal values, with the larger the dot, the darker the tonal value. In the case of frequency-modulated screening, which can be used instead of amplitude-modulated screening or in addition to it in combination with full-tone/half-tone screening, very fine screen dots that are always the same size are printed, with their number and arrangement changing. The different tonal values are created here by the irregular distribution of the halftone dots.

In the exemplary embodiment of 6 only the width of the areas A, B and C is the same, whereas their length is different. However, an inverted version of length and width is also conceivable. It is also possible, instead of area C, to provide the printing ink of area B or A in the form of a raster. The same also applies to an area D that may be present.

The security elements according to the invention are optionally available after appropriate packaging in the form of threads, strips or patches at least partial embedding in or for application on data carriers, in particular documents of value such as identity cards, cards, banknotes or labels, seals and the like. Furthermore, the security elements according to the invention in the form of a strip or patch can also be used to close an opening in a data carrier.

All of the embodiments of the invention shown in the figures are not limited to the configurations shown and can be varied and implemented in every conceivable and possible combination that will become apparent to those skilled in the art from the description.

Claims (15)

Security element with machine-readable security features in the form of magnetic materials of different coercivity, which are present in several printing inks in several areas of the same and/or different remanence on a carrier substrate, each area being formed from a printing ink that comprises at least one magnetic material that is selected from magnetic materials which have the coercivity K1, K2 or K3, characterized in that at least three different areas are provided, which are formed by different printing inks,
wherein of the printing inks of the at least three areas, at least two printing inks each comprise only a single one of the magnetic materials which have the coercivity K1, K2 or K3, and
wherein at least one printing ink comprises a mixture of at least two magnetic materials which have the coercivity K1, K2 or K3. The security element according to claim 1, characterized in that the coercive field strength K1 is 3500 Oe ± 30%, preferably ± 20%, particularly preferably ± 10%, the coercive field strength K2 is 250 Oe ± 30%, preferably ± 20%, particularly preferably ± 10% and the coercivity K3 is 1000 Oe ± 30%, preferably ± 20%, more preferably ± 10%. The security element according to claim 1 or 2, characterized in that at least one area A is provided with an ink that comprises magnetic material that exclusively has a coercivity K1, at least one area B is provided with an ink that comprises magnetic material that exclusively has a coercivity K2, and at least one area C is provided with an ink that is a mixture of two magnetic materials with the coercivity K1 and K2, where the coercivity K1 is 3500 ± 300 Oe and the coercivity K2 is 275 ± 25 Oe. Security element according to claim 1 or 2, characterized in that (a) at least one area A is provided with a printing ink that includes magnetic material that exclusively has a coercivity K1, and/or
at least one area B is provided with an ink that includes magnetic material that exclusively has a coercive field strength K2, and/or at least one area D is provided with an ink that includes magnetic material that exclusively has a coercive field strength K3, and (b) at least one area C is provided with a printing ink which comprises a mixture of at least two of the magnetic materials with the coercive field strengths K1, K2 and K3, where the coercivity K1 is 3500 ± 300 Oe, the coercivity K2 is 275 ± 25 Oe, and the coercivity K3 is 1000 ± 100 Oe. Security element according to one of the preceding claims, characterized in that more than two of the areas formed by printing inks which comprise only one of the magnetic materials which have the coercivity K1, K2 or K3 are provided and/or of the area formed by an ink comprising a mixture of at least two magnetic materials having the coercivity K1, K2 or K3, more than one is provided. Security element according to one of the preceding claims, characterized in that magnetic materials are present in the security element only in the at least three different areas. Security element according to the preceding claims, characterized in that the mixing ratio of the magnetic materials in the areas formed by a printing ink which is a mixture of comprises at least two magnetic materials which have the coercivity K1, K2 or K3, is identical and/or different. Security element according to one of the preceding claims, characterized in that the printing inks have the same and/or different layer thicknesses. Security element according to one of the preceding claims, characterized in that at least one printing color is provided in the form of a grid. Security element according to one of the preceding claims, characterized in that at least one printing color is provided as a halftone screen. Security element according to one of the preceding claims, characterized in that at least one printing color differs from the other printing colors in its concentration of magnetic material/magnetic materials. Security element according to one of the preceding claims, characterized in that the printing colors are arranged directly adjacent to one another and/or spaced apart. The security element according to any one of the preceding claims, characterized in that the mixing ratio of the magnetic materials in the areas formed by a printing ink which comprises a mixture of at least two magnetic materials which have the coercivity K1, K2 or K3 is from 20 : 1 to 1 : 20 is selected. Data carrier or document of value, having a security element according to one of Claims 1 to 15. Data carrier or document of value according to Claim 16, characterized in that the security element in the form of a thread, strip or patch is at least partially embedded in the data carrier or in the document of value or applied to the data carrier or the document of value.

Images