HK1150039B - Optically variable security element and its manufacturing method, security device, data carrier and its function - Google Patents

Abstract

The present invention relates to an optical variable security element (12) for protecting valuable items, comprising an optical variable ink layer (40), wherein the optical variable ink layer comprises a first optical variable effect pigment (34) for generating a view dependent visual effect and a second effect pigment (36) that can be reversibly aligned by an external magnetic field, wherein the saliency of the view dependent visual effect of the optical variable effect pigment (34) depends on the orientation of the magnetically aligned effect pigment (36) relative to the plane of the ink layer (40).

Description

Optically variable security element, method for the production thereof, security device, data carrier and use

Technical Field

The present invention relates to an optically variable security element for protecting valuable articles. The invention also relates to a method for producing such a security element, a security device having such a security element, a correspondingly configured data carrier and an authentication device for such a security element.

Background

For protection purposes, data carriers, such as value or identification documents, and other valuable articles (such as tags) are often provided with security elements which make it possible to verify the authenticity of the data carrier and at the same time serve as a safeguard against unauthorized copying thereof. The security element can be developed in the form of, for example, a security thread embedded in a banknote, a cover foil of a banknote with through-holes, the application of a security strip, a self-supporting transfer element (transfer element) or directly in a characteristic region of a document of value.

Security elements which exhibit a visual effect which is dependent on the angle of view have a special role in the protection against forgery, since even the most advanced copiers cannot reproduce them. To this end, the security element is provided with optically variable elements which convey different image effects to the viewer from different viewing angles and, depending on the viewing angle, display, for example, further color or brightness effects and/or further graphic patterns.

In this connection, it is known to use security elements with a multilayer thin-film element which change in colour effect as a function of the viewing angle for the viewer and which change colour, for example, from green to blue, from blue to violet or from violet to green when the security element is tilted. In the following, this color change when tilting the security element is referred to as a color shift effect.

An optically variable thin-film element is disclosed in patent publication No. 02/073250a2, in which at least one magnetic layer is integrated in its layer structure. The magnetic properties of these optically variable thin-film elements can be used as additional verification marks.

Such a security element is described in the european patent publication No. 1780040a2, which has magnetically aligned pigment particles in a subregion thereof that is capable of producing a kinematic visual effect. The magnetically aligned pigment particles may also have, inter alia, optically variable properties.

Disclosure of Invention

Based on this, it was an object of the present invention to further improve the security elements cited above, in particular to create security elements with an attractive visual appearance and high security measures, the appearance of which can be interactively influenced when checking their authenticity.

According to the invention, an optically variable security element has an optically variable ink layer comprising: a first optically variable effect pigment for producing a visual effect dependent on viewing angle; and a second effect pigment reversibly alignable by an external magnetic field, wherein the visual effect of the optically variable effect pigment dependent on viewing angle is significant depending on the orientation of the magnetically alignable effect pigment relative to the plane of the ink layer.

Such a security element provides an attractive combination of visual effects, that is to say, on the one hand, the optically variable effect of the first effect pigment and, on the other hand, the reversibly magnetically alignability of the second effect pigment, by means of which, as will be described in more detail below, three-dimensional visual effects can be produced interactively. The three-dimensional visual effect can appear or disappear again reversibly if applicable together with other information. In one development of the invention, the second effect pigments can be fixed later on, completely or partially, in the desired position by means of an activated fixing agent, so that the security element is subsequently provided with a separate marking, as described in detail below.

According to the invention, the two effects take place in interaction, wherein the significance of the optically variable effect depends on the orientation of the magnetically alignable effect pigments. In this way, the interaction of the magnetic pigments not only reveals previously invisible appearance and, if appropriate, other information, but also changes the intensity and brightness of the optically variable effect.

To ensure the reversible magnetic alignability of the pigments, the second effect pigment is preferably encapsulated within the microcapsule and is substantially free to rotate within the microcapsule. In this case, the second effect pigments are preferably aligned isotropically in the microcapsules in the absence of an external magnetic field, so that, as a whole, there is no preferred direction. In practice, there may of course be some degree of deviation from the ideal isotropic alignment due to factors such as geometry, magnetisability, viscosity of the encapsulating liquid or encapsulation structure.

The second effect pigment initially aligns rapidly after application of the external magnetic field; after the external magnetic field is interrupted, it returns to its original state. Without a restoring force or other external force, this return sometimes lasts for a very long time, requiring minutes, hours, or even days. During this time, the magnetization pattern displayed by the security element is initially still visible after the removal of the verification magnet, and only fades out when the orientation of the second effect pigment is cancelled or changed by the active movement of the external magnet.

To expedite the return to the initial state, in suitable embodiments, the microcapsules can include a gel that provides a restoring force for the magnetically alignable effect pigments. To this end, for example, transparent polymeric substances, preferably mixtures of photocrosslinkable monomers and oligomers and suitable solvents, can be introduced into the microcapsules and, by cross-coupling, systematically produce gel-like structures in the microcapsules: on the one hand it allows the effect pigments to be made rotatable by an external magnetic field and, on the other hand, when rotation has taken place, generates a restoring force which causes the effect pigments to return rapidly to their original position after interruption of the external magnetic field. In other embodiments, such a restoring force may also be generated by pre-magnetization of a magnetic layer in combination with an optically variable ink layer.

In an advantageous embodiment of the invention, the first effect pigment is present outside the microcapsules of the second effect pigment. Optionally, the first effect may also be encapsulated within microcapsules with the second effect pigment. In this case, the first effect pigments advantageously extend in plate-like form. In this embodiment, a dynamic, interactive colour shift effect can be produced by co-encapsulation, since the alignment of the first effect pigments also changes when the magnetic second effect pigments are aligned. In a special variant, the first and second effect pigments are formed by identical magnetically alignable and optically variable effect pigments.

The second effect pigment is preferably formed on the basis of a high purity iron powder and may be made, for example, from carbonyl iron powder under reduced conditions. Details of advantageous platy iron pigments are set forth in detail in European patent publication No. 1251152B1, the disclosure of which is incorporated herein by reference for its manufacture and its attributes.

Herein, the second effect pigment may be soft or hard magnetic. The second effect pigment is preferably non-spherical, e.g., needle-shaped. Effect pigments having a plate-like shape are particularly preferred here. Hereinafter, the maximum diameter of a non-spherical pigment is also referred to as the length or size of the pigment, while the minimum diameter is referred to as the thickness of the pigment.

The ratio of the largest diameter to the smallest diameter of the non-spherical second effect pigments is preferably greater than 5: 1, particularly preferably greater than 10: 1. The ratio is particularly preferably between 40: 1 and 400: 1. The maximum diameter of the non-spherical second effect pigments is preferably greater than 2 μm, preferably greater than 5 μm, particularly preferably greater than 10 μm, and very particularly preferably greater than 15 μm. In the micrometer range, in particular in the cited size range, the use of the above-described magnetically alignable effect pigments has the significant advantage that the particle concentration can be kept at a lower level compared to nanoparticles.

Plate-like effect pigments (especially in the preferred size range and in the preferred diameter/thickness ratio range) can be oriented as desired relative to the layer plane by an external magnetic field. Depending on the orientation, they either largely reveal (like the slats of a window blind) the view of the layers below them (almost vertical with respect to the layer plane) or partially (oblique with respect to the layer plane) or completely block the view (substantially horizontal with respect to the layer plane). In this way, a high contrast between the transparent and opaque layer regions can be set with a high diameter/thickness ratio.

In the context of the present specification, "translucent" means transparent with a certain or complete transparency, and further includes fully transparent. The translucent layer may allow objects located behind or below it to be seen even though the brightness of the object may be reduced and/or its color may be changed by the translucent layer. In contrast, if the layer transparency (transmissivity) is so low that the object located behind or beneath it is no longer visible, it is no longer referred to as transparent, but rather as opaque.

Instead of using non-spherical (in particular plate-like second effect pigments), the second effect pigments may also be arranged to be formed of isotropic particles that are present within the microcapsules and are aligned with each other within the microcapsules by an external magnetic field (in other words, for example, chain-like). In this way, dynamic optical effects can also be produced. Here, the isotropic particles may be nanoparticles, the particle size of which is 1nm to 1 μm, or alternatively, the particle size may be larger than 1 μm, preferably between 1 μm and 20 μm, particularly preferably between 2 μm and 10 μm. The diameter of the microcapsules is advantageously between 1 μm and 200 μm, in particular between 5 μm and 80 μm, and preferably matches the particle size of the isotropic particles in such a way that, when magnetically aligned, a plurality of isotropic particles can be arranged in the microcapsules in cooperation with one another (in particular in the form of chains).

In a preferred embodiment of the invention, the second effect pigment is formed by an iron pigment coating. The iron pigments are in particular "iron oxide" (FeO)_x) A composition wherein x is between 1.3 and 1.5. Due to the coating, the second effect pigment has another desired property in addition to its magnetic alignability. In the simplest case, the coating is a color coating comprising, for example, yellow, green and/or blue organic and/or inorganic colorants, and additionally preferably white pigments having a high scattering rate. Other coatings, such as laser-memorable, fluorescent or phosphorescent coatings, are also conceivable in order to add suitable properties to the effect pigments.

The second effect pigment can be encapsulated, for example, by selecting therein an iron pigment of an appropriate size, which can range from 10 μm to 20 μm, dispersing it in a water-insoluble solvent, preparing in advance in water an appropriate micelle precursor having a controlled particle size, and encapsulating it with acrylic gelatin, for example, by coacervation. Comprehensive information on microcapsules and the agglomeration process is described in detail in, for example, the European patent literature.

Of course other encapsulation methods are equally possible, for example emulsion polymers with acrylates, methacrylates or styrene.

The microcapsules described in this application may be composed of a number of different organic or inorganic materials. In order to ensure the desired optical and mechanical properties, in particular the capsule material is adjustable, and if polymers are used, their degree of crosslinking and the wall thickness of the microcapsules can likewise be adjusted. Preferred capsule materials include, for example, gels, modified gels, in particular gels modified by chemical post-crosslinking, polymethyl methacrylate (PMMA), and also other polyacrylates, polyurethanes, polyamides, melanin/formaldehyde, silicones and inorganic oxide materials such as silicates, titanium, chromium or iron oxides, which are suitable primarily for their high transparency.

According to the invention, the diameter of the microcapsules is advantageously between about 1 μm and 200. mu.m, in particular between about 1 μm and 80 μm. The wall thickness of the microcapsules is generally between 5% and 30% of their diameter, preferably between 10% and 20% of their diameter.

The first effect pigments are advantageously pigments based on liquid-crystalline polymers or so-called pearlescent pigments, for example silver white, gold, metallic, such as those sold by Merck KGaA under the name "Iriododin (R)", or "Colorcrypt", for example. Both pigments made on the basis of liquid crystal materials and pearlescent pigments are translucent by themselves. In a further, likewise advantageous embodiment of the invention, the first effect pigments are formed by interference layer pigments. Such interference layer pigments generally have a thin-film structure, which preferably comprises at least a reflective layer, an absorbing layer and a dielectric spacer layer arranged between the reflective layer and the absorbing layer. The interference layer pigment itself may be translucent, although opaque interference layer pigments are also well known.

In one development of the invention, the second effect pigment is encapsulated in microcapsules, which comprise an activatable fixing agent, by means of which it is possible, after activation, to fix the second effect pigment in the desired position. Such a design may enable the second effect pigment to be fixed later, fully or partially, in a desired position in order to introduce, for example, a separate logo to the security element. In this way, the printed layer with the second effect pigments can still be aligned by magnetic force after drying and be fixed in the desired position of the sub-area in the form of a pattern, character or code by means of, for example, local uv irradiation or local laser irradiation.

If the second effect pigments are subsequently fixed only in sub-regions, a combined effect is produced, in which the non-fixed regions react reversibly to external magnetic fields and are permanently fixed in the magnetic alignment of the adjacent regions, for example by UV or laser irradiation.

In a preferred embodiment herein, the microcapsule comprises a transparent polymeric mixture or substance as the activatable fixing agent and an initiator, preferably a photoinitiator, for activating the fixing agent. To this end, the second effect pigment can be suspended, for example, in a 100% system of monomers and oligomers and initiators, in the case of microencapsulation, which is preferably carried out by colloidal coacervation or miniemulsion polymerization. Here, the polymerization conditions are chosen, for example micelle or drop size selection, so as to produce microcapsules of the desired size (from 1 μm to 200 μm, preferably from 5 μm to 80 μm). The viscosity of the mixture can be adjusted either by selecting the type of monomer or oligomer or by varying the ratio thereof.

By appropriate selection of the polymerization conditions, it is possible to produce microcapsules with completely fixed effect pigments, and to produce microcapsules with a gel structure (preferably consisting of a mixture of photopolymerizable monomers and oligomers and a suitable solvent), in which the effect pigments can still be rotated by an external magnetic field, as described above, while the gel structure exerts a restoring force on the rotated effect pigments.

Optionally, the microcapsules may also include a large inert filler with additional, short, chain-like active molecules that, when irradiated, cross-link themselves with each other, with the capsule wall, and fix the effect pigments contained within the microcapsules in their place.

According to other possibilities, nanocapsules which can be destroyed by laser light can also be introduced into microcapsules with polymerization initiators, so that the fixing can be initiated by laser irradiation.

In a further variant, the microcapsules comprise a liquid which can be decomposed by laser irradiation and a pigment, for example a foaming agent. The effect pigments contained in the microcapsules are permanently fixed in their position by an increase in the amount of fixing agent. One advantage of this variant is that no subsequent crosslinking can take place, for example by leakage of the polymeric starter or by ultraviolet light.

Examples of activatable fixing agents which are suitable for foaming by laser irradiation and/or by high temperatures include polymers such as POM (polyoxymethylene), PMMA (poly (methyl methacrylate)) or PA (polyamide). Due to their decomposition properties, these polymers already tend to foam without other additives. Also, other plastics such as polystyrene, polyester fiber, or polyester resin (PET) to which a foaming agent is added to produce the desired foamability may also be used. As blowing agents, for example, carbonates, diphenyloxide-4-4 '-oxybis-benzenesulfonylhydrazide (diphenyloxide-4-4' -disulphohydrazide) or the Genitron (R) or Ficel (R) product series from Lanxess may be used. Alternatively, hollow foamable spheres may be used. Additionally, to increase the laser sensitivity of the foamable polymer, an absorber may be added for the laser wavelength range used.

In an advantageous development of the invention, the optically variable ink layer can also comprise unencapsulated, magnetically alignable third effect pigments, which are aligned by magnetic force in the form of specific figures formed by patterns, lines, characters or codes. In contrast to the alignment of the second effect pigments, the third effect pigments are permanently fixed here. For the third effect pigment, the same materials having the same size range and characteristics as the second effect pigment can be used, except without encapsulation, so that the above description in this respect can also apply to the third effect pigment.

The encapsulated second effect pigment and the unencapsulated third effect pigment may be present at least partially in the same region of the optically variable ink layer and/or at least partially in different regions of the optically variable ink layer. In both variants, as described below, a distinct visual effect with a high recognition value can be produced.

In a preferred embodiment of the invention, the optically variable ink layer comprises a pigment mixture with the first effect pigment, an encapsulated second effect pigment and, if applicable, an unencapsulated third effect pigment. Alternatively, the optically variable ink layer may be composed of a plurality of superposed sublayers, wherein each sublayer comprises only one type of effect pigment.

The optically variable ink layer is preferably formed from a screen-printed or flexographic printed layer, and in some embodiments, also a gravure printed layer. Furthermore, in all the cited embodiments, in particular to enhance the 3D effect of the magnetic alignment effect pigments, it is also possible to use the way of the plain embossing.

In order to permanently fix the magnetically aligned pattern of the third effect pigment, the ink layer is preferably formed based on a UV-curing color system. Pure UV systems, UV/water soluble systems or UV/solvent based systems may also be used. In addition to the first, second and third effect pigments (where applicable), the ink layer may also comprise other pigments, in particular isotropic pigments and/or soft magnetic pigments. Of course, other pigments or (in general) other additives may exhibit visually and/or machine-perceptible properties which do not affect the visual effect of the security element of the invention, or only slightly affect its door.

In an advantageous embodiment, the optically variable ink layer is applied on standard banknote paper or on a colored background layer. Any type of paper can be used as the base material for making currency paper, particularly cotton kraft paper. Of course, paper comprising x times the polymeric material may be used, where x may be between 0-100%.

In general, the substrate material of the banknotes or data carriers can also be a plastic film, for example a polyester film. The film may be stretched uniaxially or biaxially. Stretching of the film causes it (among other factors) to acquire light polarization characteristics that can be used as another security feature. The base material may also be a multi-layer composite comprising at least one layer consisting of paper or a paper-like material. Such a composition can also be used as a base material for banknotes and is characterized by a particularly high stability, which is quite advantageous with respect to the durability of the banknote or data carrier.

Furthermore, a multi-layer, paperless synthetic material can be used as the base material, which can advantageously be used, in particular in some climatic zones.

All substrate materials may include additives that serve as authenticity features. In particular, a phosphor can be used which is preferably transparent in the visible wavelength range and, in the invisible wavelength range, can be excited by means of a suitable auxiliary device (for example a UV or IR radiation source) to generate luminescent radiation which is directly visible or visible with the auxiliary device.

Substrates having dark colors often give rise to particularly high luminance of the optically variable effect. However, a transparent or translucent film may be used as the substrate. In this case, the security element can advantageously be used as a transparent security element on the window region or on the passage opening of the document of value. The film may be developed as a patch covering a sub-area of the substrate or as a strip across the entire length or width of the data carrier. As materials for the film, mainly plastics PET (polyethylene terephthalate), pbt (polybutylene terephthalate), PEN (polybutylene terephthalate), pp (polypropylene), PA (polyamide) and PE (polyethylene) can be used. Further, as described above, the film may be uniaxially or biaxially stretched.

The opening in the banknote can be made when manufacturing the security element for the banknote and therefore has a fibrous, irregular edge. Such edges are characteristic of openings formed during the papermaking process and cannot be created after the end of papermaking. Details regarding the manufacture of such irregular edges are described in detail in application publication number WO03/054297A2, the disclosure of which is incorporated herein by reference. In other embodiments, the openings are created by stamping or cutting (e.g., by laser cutting) only after the paper is made.

In one development of the invention, the optically variable ink layer can be applied on an information-bearing background layer, in particular on a screen-printed layer, a flexographic-printed layer or a gravure-printed layer. Since the information is visible in the translucent areas of the ink layer and obscured in the opaque areas, the ink layer and background layer may cooperate to create other authenticity features, as described in more detail below.

The background layer may also advantageously have thermochromic properties to produce a security element that can be interacted with in other ways. By specially designing such a thermochromic background layer such that the optically variable effect of the first effect pigment disappears to a viewer when it is activated by an increase in temperature.

According to one development of the invention, the optically variable ink layer is combined with a magnetic background layer (which may be present continuously or in the form of patterns, characters or codes). By means of such a magnetic background layer, the optically variable ink layer can be realized to show a desired pattern in the absence of an external magnetic field, or an initially hidden pattern is exposed by means of an external magnetic field.

In a first variant, the magnetic background layer comprises a soft-magnetic substance with a low to negligible remanence, which is provided in the form of a pattern, a character or a pattern of a code, for example. The soft magnetic substance itself cannot be permanently magnetized due to its low remanence, so that after the interruption of the external magnetic field, the magnetization no longer remains.

If the security element is exposed to an external magnetic field, the magnetic background layer is largely shielded from the magnetic field in the regions where the soft-magnetic substance is present, so that in these regions the second effect pigments are only little or not affected at all. The external magnetic field exposes the pattern present on the magnetic background layer and makes it visible to a viewer by virtue of the locally different alignment formed by the second effect pigments. In this way, a reversibly displayable magnetic pattern is generated by the magnetic background layer when the pattern contour is visualized in the absence of an external magnetic field. More precisely, the verification can be performed with a magnet that is generally readily available, for example with a permanent magnet that can be built into a cell phone, portable audio playback device, or product security system.

Pigments having desirable soft magnetic properties include, for example, soft ferrites (e.g., zinc-manganese ferrites) or various amorphous crystalline materials, nanocrystalline materials or metal alloys, all of which are well known to those skilled in the art for shielding against electrostatic or low frequency magnetic fields. The pigments are preferably embossed here in the form of magnetic printing inks. The significance of the effect can be adjusted in particular by the coloration of the printing ink and the thickness of the impression layer.

In a second variant, the magnetic background layer comprises a magnetic substance of a medium with a high coercive field strength, which can be present continuously or in a pattern. The coercive field strength is generally between 50kA/m and 300 kA/m. Such magnetic substances can still be magnetized or relatively easily be repeatedly magnetized by means of an external magnetic field. The desired pattern can be produced, for example, by a strong permanent magnet initial magnetization. After interruption of the external magnetic field, the magnetic properties are retained due to the remanence of the magnetic material, which is strong enough to retain the reversibly aligned second effect pigment in its position.

Suitable materials for this variant include, for example, mixtures or sintered materials of hard and soft ferrites and alloys, such as alnico, cupronickel or ferrocobalt.

According to a third variant of this aspect of the invention, the coercive field strength of the magnetic substance is chosen to be sufficiently large that it is no longer repeatedly magnetized by a standard permanent magnet, a very strong magnetic field being required if repeated magnetization is to be achieved (as can be produced, for example, with a powerful electromagnet or by pulsed magnetization). The coercive field strength of the magnetic substance is here higher than 300 kA/m.

In this variant, user-visible graphics that cannot be removed by means of the device can be magnetized into the magnetic background layer during the manufacture of the security element or in a subsequent individualization step. By the alignment of the second effect pigments, a visible permanent magnetic pattern is formed, which can be enhanced or weakened by an external magnetic field.

Suitable materials for this variant include, for example, anisotropic and in particular isotropic magnetic powders based on hard ferrites (e.g. barium or strontium hard ferrites), or magnetic powders based on sintered materials and alloys (e.g. neodymium iron boron or samarium cobalt). HiCo (high coercivity) material from magnetic card fields can also be considered because it has a coercive field strength of up to 4000Oe (about 320 kA/m).

The magnetic background layer can be applied directly to the paper substrate by printing an ink comprising the magnetic substances cited in the first to third variants, with a maximum possible coloration range of approximately 15% to 50%. To achieve the maximum possible layer thickness and thus a strong effect, the ink is preferably applied in screen or gravure printing.

Applying a magnetic background layer to a thin film substrate leads to other possibilities. In this way, one or more layers of magnetic material can be applied to the film by known methods. For example, the film can be dehydrated with a magnetic metal layer (for example made of iron or nickel) and demetallized in the form of the desired pattern, and overprinted or underprinted with an optically variable ink layer of the type described above. Various non-metallic layers or alloys having the desired magnetic properties with respect to coercive field strength, remanence, etc. can also be applied to the thin film by vacuum methods.

The invention also comprises a method for manufacturing an optically variable security element for protecting valuables, comprising applying an optically variable ink layer onto a substrate, wherein the optically variable ink layer comprises: a first optically variable effect pigment for producing a visual effect dependent on viewing angle; and a second effect pigment reversibly alignable by an external magnetic field, wherein the significance of the viewing angle dependent visual effect depends on the orientation of the magnetically alignable effect pigment relative to the plane of the ink layer. Here, the second effect pigment is encapsulated within the microcapsule such that it is able to rotate substantially freely within the microcapsule.

In an advantageous development of the method, an optically variable ink layer is applied which comprises, in addition to the first and second effect pigments, unencapsulated, magnetically alignable third effect pigments, wherein the third effect pigments are permanently aligned by an external magnetic field to form a graphic in the form of a pattern, a line, a character or a code.

The first, second and, if applicable, third effect pigments are advantageously mixed to form a pigment mixture and are preferably printed together in screen, flexographic or gravure printing techniques. Preferably, a pure magnetic layer with the second effect pigment is first imprinted on the substrate; next, a pure ink layer printed with the first effect pigment is printed over the pure magnetic layer. If appropriate, a further layer with the third effect pigment can be provided.

The pattern of the third effect pigment formed by magnetic alignment is advantageously permanently fixed by UV curing.

The invention also comprises a security device for protecting security documents, valuable articles and the like, having a security element of the type described above and an authentication element having a magnetically patterned zone in which magnetic material is present in the form of a pattern, line, character or code. In this case, the magnetic pattern regions are particularly advantageously magnetized substantially perpendicularly to the plane of the authentication element. The graphic shown in the magnetic graphic area may be publicly visible or may also be unrecognizable without auxiliary means, for example by covering with a dark printed layer.

In addition to the use of a patterned magnet for authentication of a security element according to the invention, the use of other magnets for authentication is also contemplated. For example, almost all modern cell phones include strong permanent magnets in the speaker. Portable audio playback devices or headsets thereof, as well as product security systems in stores, also often include permanent magnets of sufficient strength. Due to their widespread popularity, these magnets are almost everywhere available to users and (in particular in the case of security elements comprising the above-mentioned magnetic background layer) can likewise advantageously be utilized for authentication of the security element according to the invention.

The invention also comprises a data carrier, in particular a value document such as a banknote, passport, certificate, identity card or the like, which is provided with a security element or security device of the type described above. The security element, in particular if it is present on a transparent or translucent substrate, can also be arranged in or on the window region or the through-opening of the data carrier.

If the data carrier comprises a security element and an associated authentication element according to the invention, these are arranged geometrically in the data carrier in such a way that the security element is placed on the authentication element by bending or folding the data carrier.

A further object of the invention is a device for verifying the authenticity of a security element of the type described above, which has a magnetic pattern area in which the magnetic material is present in the form of a pattern, line, character or code and which is magnetized substantially perpendicular to the plane of the pattern area for the purpose of magnetically aligning the second effect pigments of the optically variable ink layer of the security element.

Drawings

The embodiments and advantages of the present invention will be described in detail below with reference to the accompanying drawings. To improve clarity, scale and proportion are not shown in the drawings.

As shown in the figure:

figure 1 is a schematic view of a banknote having a security element of the present invention;

fig. 2 shows the security element and the authentication device of fig. 1, wherein in fig. 2(a) the security element and the authentication device are spatially separated, and in fig. 2((b) the security element is placed on the authentication device;

fig. 3 is a cross-sectional view of a security element of an exemplary embodiment of the invention, without authentication means in the left half of the image and with authentication means in the right half of the image;

fig. 4 is the same cross-sectional schematic view as fig. 3 of a security element of another exemplary embodiment of the invention;

fig. 5 is a cross-sectional view of a security element of yet another exemplary embodiment of the invention;

fig. 6 is a top view of the part of the security element of fig. 5 without the authentication means in fig. 6(a) and with the authentication means in fig. 6 (b);

fig. 7 is a cross-sectional view of a security element according to yet another exemplary embodiment of the present invention;

figure 8 is a banknote having a security device of the present invention formed by security and authentication elements arranged mirror-symmetrically about a midline;

fig. 9 is the same cross-sectional schematic view as fig. 3 of a security element of another exemplary embodiment of the invention;

fig. 10 is an embodiment of the security element of the present invention having a soft magnetic background layer when authenticated with an external magnet;

fig. 11 is a security element of the invention with a magnetic background layer with a high coercivity medium of magnetic substance.

Detailed Description

The invention will now be described by way of example with reference to banknotes. To this end, fig. 1 shows a banknote 10 having an optically variable security element 12 printed directly on the banknote paper. It will be appreciated that the invention is not limited to printed security elements and banknotes, but may be used in a wide variety of security elements, such as labels and packaging for goods, valuable documents, identification cards, passports, credit cards and medical cards, and the like. In banknotes and similar security documents, it is possible to use, in addition to printed elements, for example, transfer elements, security threads or security strips, and also transparent elements in addition to top view elements.

In fig. 2, the optically variable security element 12 is shown with an external authentication device 20, wherein in fig. 2(a) the optically variable security element 12 is clearly spatially separated from the authentication device 20, while in fig. 2(b) the security element 12 is arranged on the authentication device 20.

As shown in figure 2(a), without the verification means 20 or sufficiently spatially separated from the verification means 20, the optically variable security element 12 exhibits a metallic lustre with a non-obvious consistent colourshift effect. Due to the color shift effect, the color effect of the security element changes for a viewer when tilted, e.g. green when viewed vertically from above and blue when viewed obliquely. However, other color shifts can also be seen, for example from reddish brown to green or from gold to green.

The authentication device 20 for the security element 12 has a patterned magnet 22 whose magnetic properties are indicated by magnetic field lines 24 as shown. The magnetic material of the graphic magnet 22 is provided in the form of a pattern, line, character or code, in this exemplary embodiment in the form of the letter "H". The north pole of the magnet forms the top and the south pole of the magnet forms the bottom of the magnet, so that the magnetization of the patterned magnet is perpendicular to the plane of the magnetic material. It should be understood that in general, the patterned magnets of the authentication device 20 can be any pattern, character or symbol, and their magnetic properties can be reversed or formed from a more complex sequence of north and south poles of magnets. For high magnetic properties, rare earth alloy magnets such as samarium cobalt alloy or neodymium iron boron alloy may be used as the magnetic material of the patterned magnet in addition to the commonly used magnetic materials. As described in detail below, the present invention also includes embodiments that can be verified without a particular patterned magnet.

If the user moves the security element 12 directly onto the verification device 20, as shown in figure 2(b), then in this way the user interactively changes the visual appearance of the security element 12 over the graphic magnet 22 on the area 26. The metallic luster of the area 26 is significantly reduced and the dark background layer becomes visible. At the same time, the color shift effect in region 26 is significantly enhanced in brightness and intensity.

Instead of a continuous black background layer, information such as font, serial number, denomination description, etc. can also be seen in the area 26. In the region 28 remote from the graphic magnet 22, the visual effect of the security element 12 is unchanged. Thus, the graphic depicted by the graphic magnet 22 is specifically reflected in the region 26 in the form of a picture-like color-shifting region brighter than the metallic background.

If the security element 12 and the authentication device 20 are again spaced apart from each other, the state shown in fig. 2(a) is returned so that the viewer again sees a continuous metallic lustrous surface with a weak color shift effect. Thus, the secure element 12 appears as a reversible interactive triggerable authentication mark.

The structure of the security element 12 and the creation of the reversible changes in visual effect are explained in detail below with reference to the sectional view shown in fig. 3. Here, the left half image in the figure shows the security element 12 without the authentication device 20, or the area 28 remote from the graphic magnet 22. The right half of the image shows the part of the security element area 26 that is disposed directly on the patterned magnet 22.

A printed layer 32 is applied to the banknote paper 30 of the banknote 10, which printed layer 32 may depict any information, such as a line pattern 33, alphanumeric strings, logos (logos), etc., in the region of the security element 12. The print layer 32 may also form a continuous dark background layer, such as a black background layer, as in the exemplary embodiment of fig. 2. The printed layer 32 may be printed in particular on the banknote paper 30 by screen printing, flexographic printing or gravure printing.

In this example, an optically variable ink layer 40 with a colour shifting effect is printed on the usual information carrying print layer 32 by screen printing using a pigment mixture of first 34 and second 36 effect pigments.

The first effect pigments 34 are optically variable pigments, for example, interference layer pigments having a thin-film structure composed of a reflective layer, an absorbing layer, and a dielectric interlayer disposed between the reflective layer and the absorbing layer. Pigments based on liquid crystalline polymers or colored pearlescent pigments, such as those sold by Merck KGaA under the names iriodin (r) or Colorcrypt, may also be used as the first effect pigments 34.

In this exemplary embodiment, in addition to these optically variable first effect pigments 34, the pigment mixture also comprises magnetically alignable (alignable) plate-like iron pigments 36 (as second effect pigments) which are made of carbonyl iron powder (carbonyl iron powder) treated under reducing conditions. Such plate-like iron pigments can be produced with a high ratio of plate diameter to plate thickness, the (maximum) plate diameter preferably being between 6 μm and 60 μm, particularly preferably between 10 μm and 20 μm, and the plate thickness preferably being between 40nm and 250 nm. Details of the manufacture and properties of such platy iron pigments are set forth in European patent publication No. 1251152B1, the disclosure of which is incorporated herein by reference.

As a distinguishing feature, the second effect pigment 36 is encapsulated and is able to rotate substantially freely within the encapsulation 38. In the absence of an external magnetic field, second effect pigments 36 ideally do not exhibit a preferred orientation within their encapsulation 38, such that the second effect pigments all exhibit a substantially isotropic orientation. It will be appreciated that in practice there may be some degree of deviation from the ideal isotropic alignment depending on factors such as geometry, magnetisation capability, viscosity of the encapsulating liquid or encapsulation structure.

The substantially isotropic alignment of the second effect pigments 36 corresponds to that shown in the left half of the image of fig. 3, and for illustrative purposes only four different general alignments of the pigments 36 are depicted herein.

If the security element 12 is now brought over the graphic magnet 22 of the authentication device 20, the magnetically alignable second effect pigments 36 are aligned by their magnetic field. Here, the iron pigment 36 is aligned with its plate extension along magnetic field lines 42. Due to the shape and magnetic action of the patterned magnet 22 shown in fig. 2, the magnetic field lines 42 in the region 26 pass substantially perpendicular through the ink layer 40, and the iron pigment 36, which is free to rotate within its envelope, is also aligned substantially perpendicular to the plane of the ink layer 40, as shown in the right-hand image of fig. 3.

Due to its plate-like shape, the iron pigment 36 acts like a slat of a blind, which may expose a view of an underlying layer or block a view completely or partially, to a viewer. In the region 28, the iron pigments 36 are arranged substantially isotropically (as in the left image in fig. 3), which severely restricts the view of the underlying printed layer 32, so that the ink layer 40 appears opaque in this region and the metallic luster of the iron pigments 36 determines the visual impression of the security element. By overprinting with the metallic luster of the second effect pigment 36, the color-shifting effect of the first effect pigment 34 is not visually significant and thus does not appear to be noticeable. It should be understood that in practice, the opacifying effect of the isotropically oriented iron pigment 36 results from the presence of a large amount of pigment, many times more than the few small amounts of pigment 36 in the schematic of fig. 3.

In the area 26 the iron pigments 36 are aligned by the graphic magnets 22 substantially perpendicular to the plane of the ink layer 40, if appropriate they emerge like slats of a parallel arranged louver on the view of the underlying printed layer 32 and the information 33 therein.

The colourshift effect of the first effect pigments 34 is not influenced by external magnetic fields and is present substantially both in the sub-region 26 and in the sub-region 28. However, it is generally significantly weaker and more pronounced in subarea 28 than in subarea 26 due to the overprinting with the metallic luster of the isotropically oriented second effect pigments 36. The brightness of the color-shift effect in the sub-regions 26 is also dependent on the design of the background layer 32, particularly high brightness being achievable when dark inks are used.

Due to the relatively high ratio of the plate diameter to the plate thickness, a high contrast may be created between the opaque sub-area 28 and the translucent sub-area 26. Also, the graphics produced by the plate orientation in the sub-regions 26, 28 appear visually as a three-dimensional appearance scene with a shock effect, also referred to herein as a 3D impression or 3D effect of the graphics.

If the authentication device 20 is removed from the security element 12 again, after some time the magnetically aligned iron pigment 36 loosens again to the substantially isotropic initial state of the left half of the image in fig. 3 due to its free mobility within the encapsulation 38. In this way, the change in visual appearance of the security element 12 can be interactively triggered and reversibly withdrawn again. However, without a restoring force, it takes several minutes, hours or even days to return to the isotropic initial state. As noted above, if a faster return is desired, a gel, for example, may be disposed within the encapsulation 38 to provide a restoring force for the magnetically alignable iron pigment 36.

To make the ink layer 40, the second effect pigment 36 is first encapsulated 38, and then the encapsulated effect pigments 36, 38 are mixed with the first effect pigment 34 and printed together by screen printing. The second effect pigments can be encapsulated, for example, by selecting an appropriately sized iron pigment and dispersing it in a water-insoluble solvent, preparing in advance in water appropriate micelle precursors (micella precursors) of controlled particle size, and encapsulating them with acrylic gelatin during the agglomeration process. As mentioned above, other encapsulating materials are also conceivable.

A further exemplary embodiment in fig. 4 shows a security element 50 which allows other interactive effects on the visual effect, for example by touch. For this purpose, the substrate 52 is provided with an imprint 54, in particular an offset imprint in the form of a pattern, line, character or code. Referring to fig. 3, in screen printing, flexography or gravure printing, the stamp 54 is coated with a thermochromic background layer 58, and the thermochromic background layer 58 is coated with an optically variable ink layer 40 having a first effect pigment 34 and a second effect pigment 36.

In this embodiment, thermochromic layer 58 is designed such that upon activation of thermochromic layer 58, the color shifting effect of ink layer 40 disappears and only the basic structure of iron pigment 36 is visible (to the viewer). If the colour of thermochromic layer 58 changes, for example when it is activated by raising the temperature, from black (or generally a dark appearance) to white (or generally a light appearance), the brightness of the colourshift effect decreases significantly upon activation of the thermochromic layer until the optically variable effect of first effect pigment 34 disappears completely upon a rise in temperature. At the same time the impressions 54, 56 are visible to the viewer through the very bright thermochromic layer 58.

When cooled, the color of the thermochromic layer 58 changes back to black or to the original dark appearance, the color shifting effect of the ink layer 40 again appears clear and the dark layer 58 again covers the imprints 54, 56 disposed thereunder.

In this way, by the temperature rise, the 3D information visible by means of the authentication device 20 can be interactively removed or reduced to two-dimensional information. The thermochromic layer 58 here functions as an interaction transducer by which the view of the laminate 54 or the information 56 can be displayed to the viewer. Thermochromic layer 58 may extend adjacent or be provided with information segments, for example in the form of patterns, lines, characters or codes. It may also present a mixture of different thermochromic inks with different activation temperatures, so that a cascade of optically variable effects is created when the temperature is increased.

Although in the exemplary embodiment of fig. 3 and 4, the first effect pigment 34 is present outside the encapsulation 38 of the second effect pigment 36, the first effect pigment may also be encapsulated in microcapsules with the second effect pigment, as shown in fig. 9.

Here, the structure of the security element 100 in fig. 9 corresponds approximately to the structure already described in fig. 3. However, unlike in fig. 3, the plate-like first effect pigments 102 made on the basis of liquid crystalline polymers are encapsulated together with the plate-like iron pigments 104 in microcapsules 106. In this embodiment, the orientation of first effect pigment 102 changes with the orientation of second effect pigment 104 when aligned, thereby creating a dynamic optically variable effect. By common rotation, the prominence of the viewing angle dependent visual impression of first effect pigment 102 varies with the orientation of second effect pigment 104 relative to the plane of ink layer 40.

In a further exemplary embodiment shown in fig. 5, the security element 60 comprises an optically variable ink layer 40, the optically variable ink layer 40 comprising, in addition to the first effect pigments 34 and the encapsulated second effect pigments 36, 38 already described in connection with fig. 2 to 4, unencapsulated, magnetically alignable third effect pigments 62, 64. The third effect pigments are magnetically aligned in a special pattern, and a simple stripe pattern of alternating stripes 66, 68 is illustrated in the exemplary embodiment shown in fig. 5.

Unlike the alignment of the second effect pigments, which can be interactively and reversibly changed by the user with the aid of a suitable authentication means, the alignment of the third effect pigments 62, 64 is not changed and is permanently fixed. As the material for the third effect pigment, in particular, magnetically alignable (alignable) plate-like iron pigments 62, 64 can be made of carbonyl iron powder treated under reducing conditions, as with the material for the second effect pigment, and preferably have the dimensions and characteristics already specified in the description of the second effect pigment. The second and third effect pigments incorporated into the ink layer may also be the same except that the third effect pigment is unencapsulated.

To make ink layer 40, first effect pigment 34, encapsulated second effect pigments 36, 38, and unencapsulated third effect pigments 62, 64 are mixed and printed together by screen printing. Then, a suitable external magnetic field having the desired pattern is used to magnetically align the third effect pigment. As described above, under the influence of an external magnetic field, the magnetically alignable iron pigments 36, 62, 64 are aligned with their plate regions along their magnetic field lines, such that in the region 68 where the magnetic field lines are perpendicular to the plane of the substrate, the iron pigments 64 are substantially aligned perpendicular to the plane of the ink layer in the alignment step; and accordingly in the region 66 where the magnetic field lines are parallel to the plane of the substrate, the orientation of the iron pigment 62 is substantially in the plane of the ink layer, as depicted in fig. 5.

The iron pigments 36, 62, 64, which are still magnetically aligned, are then dried together with the ink layer 40. In this case, in order to permanently fix the magnetically produced pattern of the third effect pigments 62, 64, in particular a uv-curing color system can be used, but also a pure uv system, a uv/water system or a uv/solvent system. By dry means, the aligned, unencapsulated third effect pigments 62, 64 are permanently fixed in their orientation, while the encapsulated second effect pigment 36 (due to its free rotatability within the encapsulation) returns again to a substantially isotropic alignment distribution after the external magnetic field is removed.

When the security element 60 is viewed without the aid of the authentication device 20, its visual impression is controlled by the second effect pigments 36 which are isotropically distributed and therefore appear opaque. As shown in the top view in fig. 6(a), the security element 60 without authentication means shows a metallic luster combined with a weak, consistent color shift effect.

If the security element 60 is placed on the authentication device 20 with the patterned magnets 22, the second effect pigments, which are movable and magnetically alignable, are aligned perpendicular to the plane of the ink layer 40 in some areas by the magnetic field of the authentication device (as already explained in connection with fig. 3). The permanently fixed third effect pigments 62, 64 and the non-magnetic first effect pigment 34 are not affected by the magnetic field of the authentication device 20.

In the stripe-shaped areas 68, both the second 36 and third 64 effect pigments are perpendicular to the plane of the ink layer 40, so that a view of the printed layer 32 is shown. In contrast, in the stripe-shaped areas 66, the third effect pigment 62 blocks the passage of vision parallel to the plane of the ink layer where the ink layer 40 is also opaque in the presence of the authentication device 20.

In this way, as depicted in the top view of fig. 6(b), the authentication device 20 displays a permanently fixed magnetic pattern 66, 68 in the region of the pattern magnet 22, which, due to the different alignment of the plate-like pigments 62, 64, presents a significant 3D effect to the viewer. In fig. 5, only two orientations of the third effect pigments 62, 64 are shown for simplicity, but it should be understood that any angle between the iron pigment plates and the plane of the ink layers can be determined and complex magnetic patterns can also be created by appropriate directional positioning of the magnetic field lines during the alignment step.

If the printed layer 32 comprises an information section 33 (in the exemplary embodiment shown, the repeated string of numbers "10" is taken as an example), the information section 33 becomes visible in the bar-shaped subarea 68 placed above the graphic magnet 22, while it remains covered in the opaque bar 66. By movement of the graphic magnet 22 above or below the security element 60, the user can make the initially hidden 3D graphics 66, 68 and the information segment 33 spanning the entire printed layer 32 of the security element 60 interactively and reversibly visible. Such an interactive implementation has a high identification value for the viewer and thus generally exhibits a very high protection against forgery.

As shown in the exemplary embodiment of fig. 7, the second and third effect pigments may be present in different areas of the security element 70. As already explained in fig. 5, the sub-regions 72 of the security element 70 comprise permanently fixed magnetic patterns 74, 76 with a 3D effect, which are produced by different magnetic alignments of unencapsulated iron pigments 78 and subsequent fixing.

In a further subregion 80, iron pigments 82 are present in encapsulated form and can be reversibly aligned. In the sub-area 80, the visual appearance of the security element 70 changes interactively when viewed with the aid of the authentication device 20. In particular, for the purposes described above, authentication device 20 may be used having a patterned magnet, the pattern of which corresponds to the permanently affixed magnetic pattern 74, 76. When verifying its authenticity, the same graphics are again interactively traced in the area 80, in addition to the 3D graphics 74, 76, thereby creating a self-explanatory security element with high value of interest.

It will be appreciated that the embodiments of figures 5 and 7 may also incorporate a thermochromic background layer to create other interaction possibilities if desired.

In the embodiments described so far, the authenticity verification of the security element applied to the banknote 10 is carried out with a separately provided verification device 20. However, the provision of an authentication element on the banknote itself for authenticity verification, such that the security element and the authentication element form an integrated security device, will now be described with reference to the exemplary embodiment of fig. 8.

The banknote 90 shown in figure 8(a) comprises a security element 62 of the type described above and a verification element 94, the verification element 94 being in mirror symmetrical relationship with the security element 92 relative to a centre line 96 of the banknote 90. The verification element 94 has a magnet region 98 in which a magnetic material has magnetism perpendicular to the plane of the paper and exhibits a desired pattern, such as a feather crown (crest) as shown in the embodiment of fig. 8 (a). The graphic form of the magnet region 98 may be publicly visible or may also be masked, for example, by dark overprints (dark overprints).

As shown in figure 8(b), by folding the banknote 90 along the centre line 96, the verification element 94 with the magnet region 98 is pressed over the security element 92. The magnetization of the magnet regions 98 then interacts and reversibly changes the visual impression of the security element 2 in the manner described above. For example, the visual appearance of the security element 92 changes from a uniform metallic luster with a weakly uniform color shift effect (fig. 8(a)) to a feather crown graphic depiction, wherein the feather crown is highlighted as dark and has a bright clear color shift effect. Inside the pinnate crown, other information may also be visible, such as the denomination of the banknote. The banknote 90 can be verified for authenticity by simple folding without the need for external verification means.

If the security element and the authentication device are arranged in the same data carrier, the graphics displayed during authentication and the graphics displayed overtly in the data carrier (overtly displayed graphics such as the denomination of a banknote, imprinted logos, etc.) should be appropriately coordinated, since this makes the authentication easy to understand for the user and ensures particularly simple identifiability and verifiability.

Embodiments in which optically variable ink layer 40 is combined with a magnetic background layer (which may be present continuously or in the form of a pattern, character or code) may produce other attractive effects. For the security element 110 in fig. 10, a magnetic background layer 114 is applied to a substrate 112 consisting of paper or foil, the regions 116 of the magnetic background layer 114 being in the form of a desired pattern and having a soft magnetic substrate 120 with a low or negligible remanence. An optically variable ink layer 40 having encapsulated magnetically alignable effect pigments 122 of the type described above is disposed on the magnetic background layer 114. Also, for clarity of illustration, the first effect pigments are not shown in fig. 10.

Due to the homeotropic alignment of the effect pigments 122, the pattern formed by the magnetic background layer 114 is not discernible in the absence of an external magnetic field. If the security element 110 is now exposed to the magnetic field of the external magnet 124, the magnetic background layer 114 is largely shielded from the external magnetic field in the region 116. The magnetically alignable effect pigments 122 are then unaffected or affected only to a small extent in the region 116 and substantially retain their isotropic initial orientation. In contrast, as described above, the effect pigments 122 are aligned along the magnetic field lines in the unmasked region 118.

As a result, under the interaction of the optically variable first effect pigments and/or other background layers, a different visual appearance of regions 116 and 118 is produced, thereby rendering the graphic formed by magnetic background layer 114 visible to a viewer. After the external magnet 124 is removed, no magnetism remains in the magnetic background layer 114 due to the lower remanence of the magnetic material 120, so that the effect pigments 122 return to their original position again and the displayed graphic disappears again.

Since the displayed graphics are stored in the magnetic background layer 114 of the security element 110 itself, any magnet 124 may be used for authentication purposes herein. Permanent magnets that are available everywhere are suitable and can be built into, for example, a cell phone, a portable audio playback device, or a product security system.

Fig. 11 shows a security element 130, which is a variation of the embodiment in fig. 10, in which the magnetic background layer 132 comprises a continuous magnetic substance with a high coercive field strength (50kA/m-300 kA/m).

The magnetic background layer 132 is initially magnetized by a strong permanent magnet into a desired pattern having a high magnetic field strength or a very low magnetic field strength. Due to the remanence of the magnetic material 132, after the external magnetic field is interrupted, there is still a region 134 of high or very low magnetism 136 in the background layer 132. Here, the magnetic field strength of the regions of high magnetic field 134 is sufficiently large to be able to hold the reversibly aligned second effect pigments 122 in place while the orientation of the second effect pigments 122 in the regions of very low magnetic field 136 remains substantially isotropic. The original imprinted magnetic pattern 134, 136 is thus preserved.

In other variations, the magnetic background layer 132 may also comprise a magnetic substance having a very high coercive field strength of greater than 300 kA/m. Such hard magnetic material can only be re-magnetized by a very strong magnetic field, so that the initially introduced pattern is permanently preserved under normal use conditions.

Claims (69)

1. An optically variable security element for protecting valuables and having an optically variable ink layer, the optically variable ink layer comprising:

an optically variable first effect pigment for producing a visual effect dependent on viewing angle; and

a second effect pigment reversibly alignable by an external magnetic field,

wherein the degree to which the visual angle-dependent visual effect of the first effect pigment is noticeable is dependent on the orientation of the second effect pigment relative to the plane of the optically variable ink layer.

2. The security element according to claim 1, wherein the second effect pigment is encapsulated within microcapsules and is substantially free to rotate within the microcapsules.

3. The security element according to claim 2, wherein the second effect pigments are aligned substantially isotropically within their microcapsules in the absence of an external magnetic field.

4. The security element of claim 2 wherein said microcapsules comprise a gel that provides a restoring force for said second effect pigment.

5. The security element of claim 4, wherein said gel is a swelling polymeric gel.

6. Security element according to claim 2, characterized in that the first effect pigment is present outside the microcapsules of the second effect pigment.

7. The security element according to claim 2, characterized in that the first effect pigment is encapsulated within the microcapsules together with the second effect pigment.

8. Security element according to claim 7, characterized in that the first and second effect pigments are formed by identical, magnetically alignable and optically variable effect pigments.

9. The security element according to claim 1, characterized in that the second effect pigment is formed on the basis of high-purity iron powder.

10. The security element according to claim 1, wherein the second effect pigment is soft or hard magnetic.

11. The security element of claim 1 wherein the second effect pigment is expanded into a non-spherical form.

12. The security element of claim 11, wherein the ratio of the maximum diameter to the minimum diameter of the non-spherical second effect pigment is greater than 5: 1.

13. The security element according to claim 11, wherein the non-spherical second effect pigment has a maximum diameter of more than 2 μm.

14. The security element according to claim 1, characterized in that the second effect pigment is formed by isotropic particles which are present in the microcapsules and which are aligned with each other in the microcapsules by an external magnetic field.

15. The security element according to claim 1, wherein the second effect pigment is formed by an iron pigment coating.

16. Security element according to claim 15, characterized in that the coating is a coloured, laser-memorable, fluorescent or phosphorescent coating.

17. Security element according to claim 1, characterized in that the first effect pigment is a pigment manufactured on the basis of a liquid crystal polymer or formed from a pearlescent pigment.

18. Security element according to claim 1, characterized in that the first effect pigment is formed by an interference layer pigment.

19. Security element according to claim 18, characterized in that the interference layer pigment comprises at least a reflective layer, an absorbing layer and a dielectric spacer layer arranged between the reflective layer and the absorbing layer.

20. The security element according to claim 1, wherein the second effect pigment is encapsulated in microcapsules, the microcapsules comprising an activatable fixing agent, the second effect pigment being able to be fixed in a desired position by activation of the activatable fixing agent.

21. Security element according to claim 20, characterized in that the microcapsules comprise a transparent polymerizable substance or a mixture of oligomers and monomers as activatable fixing agent, and an initiator for activating the fixing agent.

22. Security element according to claim 20, characterized in that the microcapsules comprise as the activatable fixing agent a substance which is foamable by irradiation with laser light.

23. The security element according to claim 1, characterized in that the second effect pigment is encapsulated in microcapsules having a diameter between 1 μm and 200 μm.

24. The security element according to claim 1, wherein the second effect pigment is encapsulated in microcapsules having a wall thickness of between 5% and 30% of its diameter.

25. The security element according to claim 1, wherein the optically variable ink layer further comprises unencapsulated magnetically alignable third effect pigments which are magnetically aligned in the form of specific figures formed by patterns, lines, characters or codes.

26. The security element according to claim 25, wherein the second effect pigment is present at least partially in the same area of the optically variable ink layer as the unencapsulated third effect pigment.

27. The security element according to claim 25, wherein the second effect pigment is present at least partially in a different region of the optically variable ink layer than the unencapsulated third effect pigment.

28. The security element of claim 25, wherein the third effect pigment is formed based on a high purity iron powder.

29. The security element of claim 25 wherein the third effect pigment is expanded into a non-spherical form.

30. The security element of claim 29, wherein the ratio of the maximum diameter to the minimum diameter of the non-spherical third effect pigment is greater than 5: 1.

31. The security element of claim 29, wherein the non-spherical third effect pigment has a maximum diameter greater than 2 μ ι η.

32. Security element according to claim 1, characterized in that the optically variable ink layer comprises a pigment mixture having the first effect pigment and the second effect pigment.

33. The security element according to claim 1, characterized in that said optically variable ink layer comprises:

a pure magnetic layer having the second effect pigment; and

a pure ink layer disposed on the pure magnetic layer and having the first effect pigment.

34. Security element according to claim 1, characterized in that the optically variable ink layer is formed by a screen-printed layer or a flexographic-printed layer.

35. Security element according to claim 1, characterized in that the optically variable ink layer is formed by a gravure printing layer.

36. A security element as claimed in claim 1 in which the optically variable ink layer is a plain embossing.

37. A security element as claimed in claim 1 in which the ink layer comprises isotropic and/or soft magnetic pigments in addition to the first and second effect pigments.

38. Security element according to claim 1, characterized in that the optically variable ink layer is applied on standard banknote paper or on a coloured background layer.

39. A security element as claimed in claim 1 in which the optically variable ink layer is applied to a transparent or translucent film.

40. A security element as claimed in claim 1 in which the optically variable ink layer is applied to an information-bearing background layer.

41. A security element as claimed in claim 1 in which the optically variable ink layer is combined with a thermochromic background layer.

42. A security element as claimed in claim 41 in which the thermochromic background layer is designed such that the optically variable effect of the first effect pigment disappears to a viewer when the thermochromic background layer is activated by a rise in temperature.

43. A security element as claimed in claim 1 in which the optically variable ink layer is combined with a magnetic background layer.

44. A security element as claimed in claim 43 in which the magnetic background layer is in the form of a pattern, character or code.

45. A method for manufacturing an optically variable security element for the protection of value goods, comprising applying an optically variable ink layer to a substrate, wherein the optically variable ink layer comprises:

an optically variable first effect pigment for producing a visual effect dependent on viewing angle; and

a second effect pigment reversibly alignable by an external magnetic field,

wherein the degree to which the visual angle-dependent visual effect of the first effect pigment is noticeable is dependent on the orientation of the second effect pigment relative to the plane of the optically variable ink layer.

46. The method of claim 45, wherein the second effect pigment is encapsulated within the microcapsule such that it is substantially free to rotate within the microcapsule.

47. A method according to claim 45, wherein the second effect pigment is encapsulated within a microcapsule together with an activatable fixing agent, and upon activation of the activatable fixing agent the encapsulated second effect pigment is partially or fully fixed in a desired location.

48. The method of claim 47, wherein the second effect pigment is fixed in a desired position in the sub-area in the form of a pattern, character or code by localized UV irradiation or by localized laser irradiation.

49. The method of claim 45, wherein applying an optically variable ink layer comprising unencapsulated, magnetically alignable third effect pigments in addition to the first and second effect pigments, wherein the third effect pigments are permanently aligned by an external magnetic field to form a graphic in the form of a pattern, line, character or code.

50. The method of claim 45, wherein the first and second effect pigments are mixed to form a pigment mixture and printed together.

51. The method of claim 50, wherein the pigment mixture is printed by screen printing, flexographic printing or gravure printing techniques.

52. The method of claim 45, wherein a pure magnetic layer with the second effect pigment is first imprinted on the substrate; then, a pure ink layer with the first effect pigment is printed over the pure magnetic layer.

53. The method of claim 52, wherein the pure magnetic layer and/or the pure ink layer are printed by screen printing, flexographic printing, or gravure printing techniques.

54. The method of claim 49, wherein the magnetically generated pattern of the third effect pigment is fixed by a UV curing process.

55. The method of claim 49, wherein the third effect pigment is formed in a plate shape and aligned substantially perpendicular to a plane of the optically variable ink layer in a first subregion to form a semi-transparent subregion of the optically variable ink layer.

56. The method of claim 49, wherein the third effect pigment is formed into a plate shape and is aligned in a second subregion substantially parallel to a plane of the optically variable ink layer to form an opaque subregion of the optically variable ink layer.

57. The method of claim 45, wherein the optically variable ink layer is unitarily imprinted by a gravure printing technique.

58. A security device for protecting valuable documents, value documents and data carriers, having a security element as claimed in one of claims 1 to 44 and an authentication element having a magnetically patterned zone in which magnetic material is present in the form of patterns, lines, characters or codes.

59. A security device according to claim 58, wherein the regions of the magnetic pattern are magnetised substantially perpendicular to the plane of the verification element.

60. The security device of claim 58, wherein said graphic shown in said magnetic graphic region is publicly visible.

61. A security device according to claim 58, wherein said graphic shown by said magnetic graphic region is not discernable without an auxiliary device.

62. A data carrier having a security element as claimed in claim 1.

63. A data carrier having a security device as claimed in claim 58.

64. A data carrier as claimed in claim 63, characterized in that the security element and the authentication element are geometrically arranged in the data carrier, the security element being placeable on the authentication element by bending or folding the data carrier.

65. A data carrier as claimed in claim 62 or 63, characterized in that the security element is arranged in or on a window area or a through-hole of the data carrier.

66. A data carrier as claimed in claim 62 or 63, characterized in that the data carrier is a banknote, a passport, a certificate or an identity card.

67. Use of a security element as claimed in claim 1 for protecting an article.

68. Use of a security device as claimed in claim 58 to protect an article.

69. Use of a data carrier according to claim 62 for protecting an article.