EP2318884B1 - Binary ambiguous image - Google Patents

Abstract

The invention relates to a security element for a data carrier, comprising a color layer (1) and an effect layer (2), which is substantially transparent when observed at a first angle (A) and shows a color shade when observed at at least a second, so-called effect angle (B), wherein the color shade of the effect layer produces a complementary contrast to the color shade of the color layer (1) at least in a first section (2a).

Description

The application relates to a security element for a data carrier with an effect layer, a data carrier with such a security element and a production method for such a security element.

Data carriers, such as documents of value or identity documents, in particular identity cards, credit cards or passports, or other valuables, such as branded articles, are provided with security elements for the purpose of security, which permit verification of the authenticity of the article and which at the same time serve as protection against unauthorized reproduction. Furthermore, security elements often produce a highly visible visual impression, which is why such security elements are used in addition to their function as securing means sometimes even as decorative elements for such media or for their packaging. A security element can be embedded in such data carriers, for example in a banknote or in a chip card, or designed as a self-supporting transfer element, for example as a patch or as a label, which is applied to a data carrier or other object to be secured after its production. Alternatively, however, the security element can also be integrated into the data carrier during production.

Data carriers in the context of the present invention are in particular banknotes, stocks, bonds, certificates, vouchers, checks, high-quality admission tickets, but also other papers forgery, such as passports or other identity documents, and also card-shaped data carriers, in particular credit and chip cards, as well as production assurance elements, such as Labels, seals, packaging and the like. The term "data carrier" also encompasses non-executable precursors of such data carriers which, for example in the case of security paper, are present in virtually endless form and are processed further at a later time.

To prevent counterfeiting or replication of security elements, for example with high-quality color photocopiers, security elements can have optically variable elements which convey different visual impressions to the viewer from different viewing angles. For producing effect layers showing such optically variable effects, various techniques are known. For example, optical interference layers can be present either over the entire surface or in pigment form. Such interference layers typically have a thin-film structure and, for example in the case of a multilayer thin-film structure, comprise a reflection layer, an absorber layer and one or more intervening dielectric spacers and are based, for example, on mica, on SiO ₂ or on Al ₂ O ₂ . Such interference layers are referred to as one or more layers according to the number of dielectric layers. Printing inks with interference layer pigments, for example, under the name Iriodin ^® (single layer) or Colorcrypt ^® (multi-layer) marketed by Merck KGaA. Inks with multilayer interference coating pigments are also sold under the name OVI ^® of SICPA. Instead of interference layers or interference layer pigments, cholesteric liquid crystals can also be used. These are for example as liquid-crystalline silicone polymers or as pigments in so-called STEP colors ("Shimmery Twin Effect Protection"). Furthermore, holograms, which include metallic layers typically formed by vacuum deposition, or diffraction gratings, at different viewing angles, also exhibit a different visual impression to an observer.

The various optical impressions for a viewer include, for example, a so-called color shift effect, in which for the viewer different shades are recognizable under different viewing angles. Different visual impressions can also arise because, under a certain viewing angle, the effect layer is completely transparent and thus invisible to a viewer, while it shows a hue at a different viewing angle (effect angle). Such effect layers are often iridescent, that is they show a pearlescent, as it is known for example from shells or mica. In general, those in changing viewing direction a color change-indicating pigments are referred to as goniochromatic pigments.

Single-layer interference layers, printing inks with single-layer interference-layer pigments or liquid-crystalline pigments are frequently highly translucent at all viewing angles, so that the color impression perceivable by the viewer when viewing the effect layer under the effect angle is relatively weak. Such effect layers with high light transmission are therefore preferably applied over dark or black backgrounds to improve the visibility of the color change. In contrast, multilayered interference layers and multilayered interference layer pigments exhibit low translucency and are sometimes completely opaque.

In Scripture EP 0 317 514 A1 the high translucency of an applied iriodin ink layer is used as a forgery-proof authenticity feature. The iriodin ink layer is applied over a black background, so that when viewing an unaltered security feature under an effect angle, the color impression of the applied iriodin ink layer can be perceived. A color photocopier can not detect this iriodin color because of its poor color intensity and also because of the image scan in plan view where the iriodin layer is transparent and thus just copies the black background. Thus, the optically variable color impression is missing on the copy.

To improve the visibility of the relatively weak color impression of an iriodin ink layer is in the EP 0 490 825 A1 proposed the use of several adjacent strips of iriodin color, which produce different color impressions, which increases the perceivability of the color impressions as a whole.

From the EP 0 863 815 Furthermore, the overprinting of printed information with an optically variable layer is known. The aim is to show the optically variable effect in a finely structured area, for example only within a narrow line, which can not be realized with the screen printing method typically used for optically variable colors because of its low spatial resolution. For this purpose, it is proposed to provide such finely structured regions, such as guilloches, in the printed information and to apply them, for example, in intaglio printing. The colors of the printed information and the background are then chosen such that the optically variable effect of the entire surface overlying effect layer is perceived for a viewer, for example, only on the printed in intaglio fine-structured areas.

US 2005/240549 A1 discloses a security element comprising a backing and two layers wherein the hue of one layer forms a complementary contrast to the hue of the other layer and a method of making the security element.

The optically variable colors commonly used for security elements are not readily available to a counterfeiter. However, at least for an inexperienced or inattentive viewer, similar color impressions can also be achieved via other substances, as occur, for example, in nail polish. Not only monochrome imprints can be left out optically variable colors, but also two- and multi-colored imprints emulate.

The object of the present invention is to provide a security element with improved testability for authenticity and with improved protection against counterfeiting. It is a further object of the invention to specify a data carrier and a production method for such a security element.

This object is achieved by a security element, a data carrier and a manufacturing method having the features of the independent claims. The dependent claims relate to preferred embodiments and further developments of the invention.

The security element according to the invention comprises a color layer and an effect layer. The color layer has a hue that can be visually perceived and that does not change as the viewing angle is changed, for example by tilting the security element. The effect layer is substantially transparent at a first angle, for example in plan view, and is scarcely, preferably not at all, perceived by the viewer at this angle if, as assumed for the following description, it lies in the direction of observation above the color layer. Thus, a color impression results for the viewer in plan view, which is preferably determined exclusively by the hue of the underlying color layer. In the context of the present application, essentially transparent means that the observer does not perceive the effect layer at all or hardly at all under a certain viewing angle due to its complete transparency or very high translucency.

When viewed at a second angle, the so-called effect angle, and the effect layer gives the viewer a hue, with both color impressions are superimposed. According to the invention, the effect layer imparts a hue which produces a complementary contrast to the hue of the color layer. Preferably, the hue of the color layer and the effect layer are complementary colors.

The definition of complementary colors depends on the color space. For example, it is required that spectral light sensitivities for photo-optic vision (daytime vision) add up to 1 at any point in the visible spectrum. In this definition, the additive mixture of complementary colors so white (see Lexicon of Optics, published by: Harry Paul, Spektrum Akademischer Verlag GmbH, Heidelberg, 2003, page 360). Contrary to such a strict mathematical definition, the present invention is based on the recognition that, when viewing a translucent, colored layer, which is arranged on an underlying, for example, opaque color layer, the color impression resulting for the viewer especially from the hue of the overlying translucent layer is dominated when they are essentially complementary shades. The two shades may have slight deviations from the strict definition of complementary colors, which is expressed below by the term "complementary contrast". When viewed under the effect angle, an effect layer forms such a colored, light-transmissive layer. The viewer then perceives predominantly the hue of the effect layer under the effect angle. In this case, the hue of the underlying color layer largely, ideally completely, back and is correspondingly little or no longer perceived.

The use according to the invention of colors which produce a complementary contrast to each other thus aids in "fading out" the hue of the color layer and "fading in" the hue of the effect layer in the transition from the first viewing angle to the effect angle. In other words, the security element has a binary tilting effect, since when viewed at a first angle, ideally only the hue of the color layer and, when viewed under the effect angle, ideally only the hue of the effect layer is visible.

To achieve a binary tilt effect and thus to the maximum hiding of the hue of the color layer by the hue of the effect layer, the selection of colors according to the invention is also advantageous because under the effect angle, the reflection spectrum of the underlying color layer by the overlying effect layer with the at least approximately complementary hue in addition is hidden (absorbed) and mixes with the harmonic hue of the effect layer, so that the hue (motif) of the hidden or mixed color layer is no longer perceived by the human eye. By contrast, the subject's effect is recognized by the viewer and then dominates over the hue (motif) of the underlying color layer.

Basically, the majority of the optically variable layers known in the prior art are suitable as the effect layer. But single-layer interference layers, colors with single-layer interference pigments, for example Iriodin ^® Colors of Merck, or multi-layer interference layer pigments, for example Colorcrypt ^® Colors Merck and colors with cholesteric liquid crystal pigments are particularly preferred. The available for example from Merck Iriodin pigments are usually pigments with a core of mica, which is an interference layer, in particular of titanium dichloride, iron chloride or a combination of titanium dichloride and iron chloride.

The layer thicknesses of the interference layer are chosen so that they are in the wavelength range of the desired color (1st order) or at a multiple of the desired wavelength (2nd, 3rd, 4th, etc. order). In general, pigments having an interference layer thickness in the range of the multiple of the desired wavelength, often also referred to as "higher order pigments", are stronger in color than so-called "1st order pigments". As a rule, the observer can perceive a single characteristic color only at a certain viewing angle. In the example of shopping available Colorcrypt ^® pigments are generally pigments having a core of silicon oxide having an interference layer, which comprises a plurality of layers, in particular intermediate layers. Depending on the layer thickness of the individual layers, the viewer thus perceives different colors under different viewing angles, but only under a relatively narrow wavelength range around a specific center wavelength. In contrast, the OVI ^® pigments or OVI ^® have -Farben SICPA to a viewing-angle dependent color-shift effect in a relatively wide wavelength range.

The Colorcrypt available from Merk ^® pigments are considerably more expensive than the Iriodin also available from Merck ^® pigments in the making, so that Colorcrypt ^® pigments are much more expensive than Iriodin ^® pigments, which prevents counterfeiters cost reasons before these pigments and thus further increases the counterfeit protection of ^® with Colorcrypt pigments equipped security elements according to the invention. Furthermore Colorcrypt ^® pigments from Merck clearly under the microscope to recognize what can serve as a proof of authenticity with a suitable tool. It is understood that the effect pigments mentioned above or preferably used are to be considered as illustrative rather than restrictive.

Particularly preferred are single layer interference layers, Iriodin ^® -and- Colorcrypt ^® Colors of Merck and colors with the cholesteric liquid crystal pigments, in particular because these at all viewing angles exhibit a high light transmittance, at the first viewing angle, that is, for example, in plan view, are often completely transparent and, when viewed despite the translucency, they show a sufficiently intense hue under the effect angle.

In order to achieve a sufficiently intense hue of the effect layer, a sufficient amount of eg Iriodin ^® pigments must be applied. The coated surface should ideally be equipped with a substantially closed Iriodin ^® -Pigmentschicht. This is achieved by applying on average an application amount of about 9 g / m ² (dry) of Iriodin ^® effect color, resulting in an approximately 30 μm thick pigment layer. An additional increase in the intensity of the hue is achieved by a calendering of the substrate, because the flat pigments align themselves even better in a plane.

The underlying color layer is preferably an opaque layer, whereby the hue of the security element is independent of the substrate used. On the other hand, if such an interaction with the substrate, for example with a different-colored or else translucent substrate, is intended, a translucent, that is to say semitransparent, color layer can also be used.

The effect layer is preferably arranged on the color layer so that it directly adjoins the color layer. On the other hand, it is also conceivable to provide further translucent or transparent layers between the color layer and the effect layer.

In order to ensure good perceptibility of the binary tilting effect according to the invention and the "fade-out" and "fade-in" described above, it is advantageous for the color layer and the effect layer to be separate layers and not for example to form a substantially homogeneous layer which is a mixture of colors which according to the invention in each case build up the color layer and the effect layer.

Preferably, the effect layer is spatially structured, that is applied in partial areas on the underlying color layer, so that it conveys information to the viewer. For this purpose, for example, a recess may be provided in the effect layer, which may be e.g. is advantageous for an effect layer formed from cholesteric liquid crystal pigments. Thus, when viewed under the effect angle, the effect layer only shows a hue complementary to the color layer in a first subregion. Preferably, the effect layer has, in addition to or instead of a recess, a second portion in which the effect layer under the angle of effect shows a second color, which is in harmony with the color tone of the color layer. The angle of effect of the first and second subregions is identical or there exists at least one viewing angle, below which the first and the second subregions at the same time show the hues described above; this angle is then called the effect angle.

Color shades which are in harmony with one another are understood to mean shades which contain at least one identical primary color. in particular, contain a same primary color as a main component and are thus similar. Furthermore, colors in harmony with one another generally have comparable brightness and / or color saturation, which is often the case, in particular, for the color layer according to the invention.

Since the hue in the second portion of the effect layer is preferably in harmony with the hue of the underlying color layer, the hue of the second portion of the effect layer and the hue of the first portion of the effect layer also produce a complementary contrast when viewed under the angle of effect.

Since the second subregion of the effect layer, when viewed under the effect angle, preferably exhibits a hue in harmony with the underlying color layer, the color impression that the viewer already receives through the underlying color layer is intensified in this subregion by the effect layer.

In one variant, for one of the subregions of the effect layer, in particular for the first subregion, a highly translucent, optically variable ink layer, preferably an iriodine ink layer, is used, while for the other subregion, preferably for the second subregion, a semitransparent or optionally even opaque color layer, preferably a high opacity Colorcrypt or OVI color layer is used. It is also possible to use gloss lacquer in the second subregion of the effect layer instead of an optically variable ink layer. In this case, both subsections of the effect layer ideally have an identical effect angle and an identical angular range in which the respective color impressions of the two subregions of the effect layer can be perceived.

Preferably, the color layer also has at least two partial areas, which impart different color impressions to a viewer. The shades of the different subregions of the color layer are advantageously in harmony with each other.

By using a plurality of differently colored subregions in the ink layer, they are clearly visible to the observer, at least at the first viewing angle, that is, for example in plan view. On the other hand, because of the requirement that the different subregions of the color layer are in harmony with each other, when looking at the security element under the effect angle, all subregions of the color layer and thus the entire color layer will be affected both by the first, complementary contrast subregion of the effect layer and by the second , concealed in harmony part of the effect layer. In this case, the reflection spectrum of the color layer is reinforced by the reflection spectrum of the effect layer in the second subregion of the effect layer whose hue is in harmony with the hues of the color layer. In other words, the slightly different hues of the different subregions of the color layer within the second subregion of the effect layer are added to a further, preferably much more intense hue. As a result, the second subregion of the effect layer, when viewed under the effect angle, outshines the small difference in hue of the underlying different subregions of the ink layer, so that a viewer perceives the different subregions of the ink layer only barely, preferably not at all, differently. Similarly, when viewed under the effect angle, the hue of the first portion of the effect layer outshines differences in the reflection spectra of the various portions of the underlying color layer. The hue of the first portion of the effect layer generates a complementary Contrast with the several harmonizing shades of the different parts of the color layer.

The differently colored subregions of the color layer can be produced, for example, by applying color layers with different color tones or by applying a color in different rasters, that is, in different raster patterns. For example, a certain point density of the grid points is provided in a subarea, while in another subarea a different point density is provided or the color is applied over the entire surface, so that when rasterized for a viewer a color impression with a hue results, which is a mixed hue from the for the halftone dots used color and the background color, for example, the substrate is. The mixed color depends on the area proportions, for example, the dot density and dot size of the applied color. As a result, the harmonious, differently colored portions of the color layer can also be created by using only a single color.

Preferably, both in the color layer and in the effect layer, the various subregions are stacked in such a way that both the effect layer and the color layer (apart from any rastering, if appropriate) are applied over the entire area. Preferably, the various subregions are applied to partial printing operations of a single printing operation, which ensures a low pass tolerance of the subregions.

By such full-surface printing, the different sub-areas of effect layer and color layer can be seen for a viewer only on the basis of their different shades. As a result, for example, the perceptibility of the partial areas of the color layer for the viewer under the effect angle further reduced by the above-described overexposure through the subregions of the effect layer under effect angle consideration. If the different subareas of the color layer form information for the viewer, then by tilting the security element, this information can be hidden for the viewer under the effect angle.

Preferably, also the first and the second partial area of the effect layer form a second information different from the first information of the color layer. Thus, since the first information of the color layer, for example, in plan view is well visible and hidden under the effect angle and replaced by the second information of the effect layer, results for the viewer when tilting the security element, a digital information exchange between the first and second information and preferably a complete transition from the first information to the second information.

It is also advantageous if both information are displayed with similar design means, for example, each of two colors are constructed, including both the effect layer and the ink layer needs to have only exactly two subregions each. It is furthermore advantageous if both information items are shown, for example, with similar line thicknesses, that is to say with subregions of similar spatial dimensions.

The binary tilting effect described above then leads to a digital change of information. However, this takes place only in the above-described, targeted selection of shades. The lack of a change of information or an incomplete information exchange can also easily recognized by an inexperienced viewer. For a counterfeiter, however, such an accurate selection of the shades can only be reproduced with great difficulty, since the corresponding colors are not freely available and the products otherwise used to imitate such optically variable effects, for example nail polish, can not produce such a digital image change ,

It is also advantageous if both the information of the effect layer and the information of the color layer each have a meaning content and, for example, instead of an abstract representation each show an easily recognizable for a viewer motive. Advantageously, the two motifs are clearly different from each other and also have a significantly different meaning content. For example, one of the two motifs may show a stylized object, such as a crown, an animal, an animal's head, a plant, a known landmark, or the like, while the other motif may have, for example, a numerical value or individual letters, preferably a single one Letters shows. For the fast, easy perceptibility of such motifs, it is also advantageous if they have no fine structure. In addition, an interference structure around such motifs may be provided which further reduces the perceptibility of the respective other motif to be hidden. It is also advantageous if both motifs have an approximately equal spatial size.

Such a motif change supports the perceptibility of the digital information change when tilting the security element between the first angle and the effect angle, because the viewer "holds tight" to such easily recognizable and easily interpretable motifs and thus possibly remaining, unwanted color differences of the motif to be hidden mentally suppressed. This is because when tilting next to the color change also takes place for the viewer subjectively dominant change of image motif.

It is also advantageous if the binary information or motif change takes place with tilting by only a few angular degrees, for example, tilting by 1 °, 2 °, 5 °, 10 ° or 20 °. Such a sharp transition between the motifs is advantageous for easy visibility of the tilting effect and also for easy perceptibility of the various information.

The easy perceptibility and verifiability of the motifs can be further promoted by the fact that they are additionally printed in the vicinity of the effect or color layer again, which allows a self-verification. In such a case, the viewer can thus easily check whether e.g. the effect layer under the effect angle additionally shows the motif printed near the security element.

According to a further advantageous embodiment, the color layer and the effect layer are arranged congruently one above the other. This results in a clearly demarcated, easily perceptible area for a viewer on the data carrier, which is affected by the digital information exchange or image motif change.

Preferably, effect and color layers have a high register accuracy with each other, as can be achieved in partial printing operations of a single printing operation.

Preferably, the color layer and the overlying effect layer are at least partially surrounded by a further color layer. For this purpose, the surrounding color layer contains a recess and the outer contours of the color and effect layer are based on the outlines of the recess of the surrounding color layer. Preferably, effect and / or color layer and the surrounding color layer are in shock-to-impact with high registration accuracy. As a result, two easily perceptible areas are created on the security element, which behave significantly different when tilting the security element. This promotes the perceptibility of the tilt effect and of the digital information or picture motif change in the area of the color and effect layer.

Preferably, the surrounding color layer also has at least two partial areas whose color shades are in harmony with one another in color and which preferably have similar design features, such as, for example, similar line thicknesses, such as the information in the color and / or effect layer.

Preferably, the design means of the effect layer in the surrounding color layer are selectively continued, so that there is a creative relationship between the effect layer and the surrounding color layer. As a result, conversely, the information or the motif of the effect layer forms a continuation of the design of the visible under each viewing angle surrounding color layer, which favors the perceptibility and recognizability of the subject of the effect layer when viewed under the effect angle for the viewer on the basis of targeted continuation. By contrast, the surrounding color layer, due to its design, stands out clearly from the color layer arranged below the effect layer, that is to say from its information or motif, as a result of which its recognizability is also noticeable and perceptibility increased due to the contrast with the surrounding color layer. Overall, the perceptibility of the inventive binary tilting effect between the respective motifs of the color layer and the effect layer is thus improved.

In an alternative variant, the design of the color layer underlying the effect layer is continued in the surrounding color layer, as a result of which the surrounding color layer clearly stands out from the subject of the effect layer. In this variant, too, there is an increased perceptibility of the binary tilting effect due to the surrounding color layer.

Advantageously, at least one hue of the different subregions of the color layer has a secondary or tertiary color, ie a mixture of two or three primary colors of a color space. This extends the range of hues which can produce a complementary contrast in the present sense. This is particularly advantageous if not every hue of the color spectrum is available as a hue of the first subregion of the effect layer, for example with a limited selection of corresponding pigment printing inks.

The present invention described digital information exchange does not require embossing of the security element. Advantageously, however, the security element is additionally embossed in the area of the effect color, in particular blind embossed, whereby a different viewing angle and thus one of the other areas of different viewing impression arises in the region of the flank angle of the embossment. Thus, further creative degrees of freedom and other optically variable effects can be achieved. In a further advantageous embodiment of the security element according to the invention, at least one subregion of the color layer or a subregion of the effect layer contains at least one further substance, for example a luminescent substance, an infrared absorber, a thermochromic color, a marker, a cholesteric color and / or a magnetic pigment. In this case, the colors hereinafter referred to as "cholesteric colors" usually have cholesteric liquid crystal pigments as an essential component. In this way, additional effects can be generated and / or further authenticity features can be inserted into the security element, which if appropriate can only be recognized under special conditions and / or with auxiliary means.

Preferably, such a further substance is present both in a partial area of the color layer and in a partial area of the effect layer. In this case, these two subregions of the color layer and the effect layer complement each other to a third information, for example to a third motif. Thus, the security element according to the invention contains additional information which can be recognized under suitable observation conditions, for example in the case of UV irradiation in the case of luminescent substances.

In a further advantageous embodiment of the security element according to the invention, at least one of the two subregions of the color layer is formed by two mutually metameric colors. The colors can be chosen so that the two metameric colors produce the same color impression in a conventional light, for example in natural light in a viewer, while they produce a different color impression only when illuminated with a special light source. This can be a hidden, imperceptible in ordinary handling Security feature to be created.

In the security element described so far, it has been assumed that the effect layer is arranged spatially above the color layer and thus the viewing of the color layer through the effect layer occurs. In principle, however, a reverse layer structure is also conceivable. For this purpose, for example, a transparent, semi-transparent or opaque effect layer with an overlying translucent, advantageously highly light-permeable color layer is used. If the security element according to the invention is arranged on a translucent, in particular transparent, substrate, such as a film element, both the arrangement of the color layer on the substrate with the effect layer applied above and the arrangement of the effect layer on the substrate with the color layer applied thereto come into consideration. A security element with a translucent, in particular transparent, substrate may e.g. when placed over a recess (hole) of the document of value, usually viewed from two sides. The materials used for the film element are primarily the plastics PET (polyethylene terephthalate), PBT (polybutylene terephthalate), PEN (polyethylene naphthalate), PP (polypropylene), PA (polyamide), PE (polyethylene) into consideration. The film may also be monoaxially or biaxially stretched.

In principle, it should be noted that the substrate material used for the application of the security element is any type of paper, in particular cotton paper. Of course, it is also possible to use paper which contains a proportion of polymeric material in the range of 0 <x <100% by weight.

Furthermore, it is conceivable, although not currently preferred, for the substrate material of the data carrier to comprise a plastic film, e.g. a polyester film is. The film may also be monoaxially or biaxially stretched. The stretching of the film, inter alia, leads to it receiving polarizing properties that can be used as another security feature.

It may also be expedient if the substrate material is a multilayer composite which has at least one layer of paper or a paper-like material. Such a composite is characterized by an extraordinarily high stability, which is of great advantage for the durability of the substrate or data carrier.

It is also conceivable, however, to use a multilayered, paper-free composite material as the substrate material, which is very advantageous, above all, for identity cards and credit cards. These materials can be used with particular advantage in particular climatic regions of the earth.

For the effect layer, not only a single color producing a color impression can be used, but it is also possible to use mixtures of different colors with optionally different pigments and pigment types. Thus, for example, various iriodin pigments can be mixed and thus the desired hue, effect angle and effect angle range of the respective subregion of the effect layer can be adjusted in a targeted manner. Likewise also different Colorcrypt pigments, OVI pigments and STEP pigments can be mixed in order to produce a desired color impression. Furthermore, these different types of pigment can be mixed with each other, so that in a portion of the effect layer, a suitable mixture of two or more Iriodin, Colorcrypt, OVI and STEP pigments are present. Likewise, these pigments can also be used with other pigments. In particular, a mixture of iriodin and silver pigments is advantageous.

All materials used for the substrate, the color layer and the effect layer can have additives which serve, for example, as an authenticity feature.

It is primarily to be thought of luminescent substances which are preferably not visible in the visible wavelength range and for example transparent and in the non-visible wavelength range by a suitable tool, e.g. a radiation source emitting UV or IR radiation, can be excited and then display a visible or at least detectable with auxiliary luminescence. The luminescent substances have suitable luminescence properties depending on the desired effect. This applies in particular to the excitation and emission wavelengths or spectra as well as the temporal decay behavior (fluorescence or phosphorescence) after switching off the excitation radiation. If several different luminescent substances are used, they can differ in their luminescence properties depending on the desired effect. For example, phosphorescent luminescent substances with different emission decay times can be used in the different subregions of the color layer and the effect layer.

Other security features can also be used with advantage, as long as they do not impair the contemplation of the binary tilting effect of the security element according to the invention or at least do not significantly affect it. These include, for example, infrared absorbers (with suitable, possibly different selected absorption and / or emission properties), thermochromic colors, metameric colors, markers such as markers, hologram flakes and / or luminescent substances, which serve as an authenticity feature, cholesteric colors or soft and / or hard magnetic magnetic pigments into consideration. These various additives can also be used in combination with one another and provided for this purpose in one or in different subregions of the color layer and / or the effect layer. In the case of metameric colors, a portion of the color layer or the effect layer may be divided into two contiguous or non-contiguous subregions, each having a color applied to each of the two subregions metameric to the color of the other subarea. When exposed to, for example, white light (D65), colors in the two sub-areas produce an identical color impression, while with appropriate exposure, for example with a light bulb, they produce different color impressions.

The effect layer can be glossy or matt. In this case, either the effect layer can be made as such matt or glossy, which can be realized with suitable, for example, UV-crosslinked binders, such as monomers or prepolymers. Alternatively, a gloss or matt lacquer can also be applied over the effect layer, for example by printing.

Particularly preferably, a portion of the effect layer is dull, while the other portion of the effect layer is glossy. This enhances the recognizability and perceptibility of the motif of the effect layer when viewed under the effect angle, while the visual impression of the two subregions of the effect layer hardly differs from the top view. This also makes the perceivability of the binary tilting effect according to the invention between the information of the color layer and the information the effect layer improves. If glossy or matt varnish is used to produce this effect in regions, then it is preferably printed in precise registration over the effect layer of the security element. An exemplary formulation for a (water-based) gloss varnish that can be applied by flexographic printing comprises about 10 to 20 wt .-% of a polyurethane dispersion, about 1 wt .-% defoamer, about 1 wt .-% wax and about 78 to 88 wt .-% of a polyacrylate dispersion. An exemplary formulation for a (water-based) matt lacquer which can be applied by the flexographic printing process comprises about 10 to 20% by weight of a polyurethane dispersion, about 1% by weight defoamer, about 1% by weight wax, about 8 wt .-% matting agent based on silica, about 2 wt .-% water and about 68 to 78 wt .-% of a polyacrylate dispersion.

Advantageously, the security feature is used to secure goods, valuables, data carriers and other objects, in particular for counterfeit protection.

The various subregions of the effect layer can in principle be applied using all standard printing methods, such as screen printing, flexographic printing, intaglio printing and intaglio printing methods. However, preference is given to a screen or flexographic printing process. In this case, the flexographic printing process is particularly preferred, in particular for paper-based substrates, since it allows a higher processing speed and essentially achieves the quality of a screen printing process when printing the effect inks. Furthermore, the gravure printing method is particularly preferred, in particular for plastic film-based substrates (with and without pressure-receiving layer).

The different subregions of the ink layer can also be applied in principle with almost all common printing processes. Prefers However, the offset printing method is used, wherein the application of the ink layer in the wet-offset, dry-offset and most preferably in the indirect high-pressure process can take place

Likewise, the surrounding further color layer can be applied with all common printing methods. Preferably, however, an indirect high-pressure process is used for this purpose in a so-called supersimultaneous pressure. The supersimulting printing machines used allow a very accurate printing of all inks on one side as well as all inks from the front and back of the substrate / data carrier to be printed.

Advantageously, the indirect high-pressure process for the color layer and the flexographic printing process for the effect layer are used in a printing process which then comprises, for example, four partial printing steps (two partial printing steps for the color layer or effect layer respectively). Furthermore, the indirect high-pressure process, implemented in a super-simultaneous printing machine for the surrounding further ink layer, can also be combined with these printing steps, so that, for example, the respectively two partial areas of ink layer, effect layer and surrounding ink layer are printed in six partial printing processes in one printing process.

Preferably, on a substrate, for example a security paper as a precursor for a banknote, first the surrounding further color layer is printed, then the color layer and subsequently the effect layer.

Fig. 1

eine Banknote mit einem erfindungsgemäßen Sicherheitselement,

Fig. 2

einen Schichtaufbau eines erfindungsgemäßen Sicherheitselements im Querschnitt,

Fig. 3a und Fig. 3b

zwei Motive für einen digitalen Informationswechsel,

Fig. 3c

eine Variante der Effektschicht des erfindungsgemäßen Sicherheitselements,

Fig. 4

noch eine Variante der Effektschicht des erfindungsgemäßen Sicherheitselements,

Fig. 5

eine Variante des Schichtaufbaus des erfindungsgemäßen Sicherheitselements,

Fig. 6

eine Variante der Farbschicht mit metameren Farben, und

Fig. 7

eine Variante des Motivs der Farbschicht.

Further exemplary embodiments and advantages of the invention are explained below by way of example with reference to the accompanying figures. Show it:

Fig. 1

a banknote with a security element according to the invention,

Fig. 2

a layer structure of a security element according to the invention in cross-section,

Fig. 3a and Fig. 3b

two motives for a digital change of information,

Fig. 3c

a variant of the effect layer of the security element according to the invention,

Fig. 4

another variant of the effect layer of the security element according to the invention,

Fig. 5

a variant of the layer structure of the security element according to the invention,

Fig. 6

a variant of the color layer with metameric colors, and

Fig. 7

a variant of the motif of the color layer.

In Fig. 1 is shown as a disk a banknote. This comprises a color layer 1 and a congruent overlying effect layer 2 and a surrounding further color layer 3 (see Fig. 2 ). Furthermore, the denomination in the form of the value "50" is applied to the banknote.

Fig. 2 shows a schematic cross section through a security element. On a substrate 4, a color layer 1 with a plurality of abutting, opaque portions 1a, 1b is applied. On the ink layer 1, an effect layer 2 having a first portion 2a and a second abutting portion 2b is arranged. Both the color layer 1 and the effect layer 2 each carry information in the form of a motif (see FIGS. 3a and 3b ), whereby the motives differ from each other. In plan view A ( Fig. 3a ; Viewing angle of 0 °), both sections 2a, 2b of the effect layer 2 are transparent, so that the information of the underlying color layer 1 is visible, while the information of the effect layer 2 is not visible. The partial areas 1a and 1b of the color layer 1 are in color harmony with each other. When viewed under the effect angle B ( Fig. 3b ) of, for example, 45 °, both subregions 2a, 2b of the effect layer 2 each show a hue, the hue of the first subregion 2a producing for the viewer a complementary contrast to the hues of the subregions 1a, 1b of the color layer 1 and the hue of the second subregion 2b is in harmony with the color tones of the subregions 1a, 1b of the color layer 1.

In other words, in the case of a top view of the security element, ie when viewed along the surface normal of the security element, the color impression of the color layer 1 below the effect layer 2 is predominant due to the high transparency of the effect layer 2. Thus, in the ideal case, the safety element is exclusively the top view Motif of the color layer 1 recognizable, which is produced by two colors in harmony, but yet distinguishable by a viewer colors. In this case, the viewing may take place under illumination with diffused light.

In the case of observation under the "effect angle" (also called the "glancing angle"), the color impression of the underlying color layer 1 is ideally completely masked due to the transparent mirror gloss of the effect layer 2 or of the two effect colors used in the subregions 2a and 2b, so that in the ideal case only the subject of the overlying effect layer 2 is perceived by a viewer. In other words, the matte / gloss effect is so dominant that the viewer primarily perceives and evaluates the information generated by the matte / gloss effect. In this case, ideally directed light is used for illumination and the viewing and illumination angles are symmetrical with respect to the surface normal of the security element. Lighting and viewing angles are, for example, 30 °, 45 °, 60 ° or 75 ° with respect to the surface normal.

The congruent color and effect layers 1, 2 are surrounded by a directly adjoining further color layer 3. This color layer 3 again comprises two partial areas 3a and 3b, wherein in the in Fig. 2 shown cross section only part 3a to the effect and color layers 1, 2 abuts. In another cross section, for example, subregion 3b would abut the color and effect layers 1, 2.

This in Fig. 2 schematically shown security feature when tilting between the top view A and the angle of effect B alternately the information of the ink layer 1 and the information of the effect layer 2, wherein to achieve a binary, complete information or image motif change for the different sections 1a, 1b, 2a, 2b 3a, 3b of the color layer 1, the effect layer 2 and the surrounding color layer 3, suitable colors with suitable color tones must be selected.

• umgebende Farbschicht 3: P 214 (rot) und P 326 (blaugrün);
• Farbschicht 1: P 658 (blau) und P 529 (violett);
• Teilbereich 2a: Iriodin kupfer (komplementärer Kontrast); und
• Teilbereich 2b: Colorcrypt lilac-green (in Harmonie).

In a first exemplary embodiment, the following colors are used for the subregions of the layers:

• surrounding color layer 3: P 214 (red) and P 326 (blue-green);
• Color coat 1: P 658 (blue) and P 529 (purple);
• Subarea 2a: Iriodin copper (complementary contrast); and
• Section 2b: Colorcrypt lilac-green (in harmony).

The names of the various inks (e.g., P 214) refer to the PANTONE color spectrum. Other color systems, such as MKS and / or RAL, are of course also possible to designate the colors.

The exact assignment of the colors mentioned to the different subregions of the color layers 1 and 3 is irrelevant. The hues in the sub-areas 1a, 1b and 2b are in harmony with each other while the hue in sub-area 2a produces a complementary contrast to the hues of the sub-areas 1a, 1b and 2b.

In a first variant of the embodiment, color green gold (green contrast) is used for the subarea 2a, while the color Iriodin lilac (in harmony) is used for the subregion 2b. In a second variant of the first exemplary embodiment, the color iriodin copper (complementary contrast) is used in the subregion 2a, while in the subregion 2b the color STEP copper-green (in harmony) is used. STEP inks are generally based on cholesteric liquid crystal pigments and show a color shift effect. The color "STEP copper-green" shows the specified color. In a further variant of the first exemplary embodiment, partial area 2a also contains such a STEP color with a suitable complementary hue.

The perceptual color characteristic of the first variant of the first embodiment was quantified using a multi-angle measuring device (model X-Rite MA 98 of the manufacturer X-Rite) in the Lab color space. In the measurement arrangement "top view", illumination takes place at an angle of 45 ° to the surface normal of the security element, while a viewing along the surface normal occurs. In the measuring arrangement "effect angle" also takes place illumination at an angle of 45 ° to the surface normal, while the observation takes place at 30 ° to the surface normal and thus under a shifted by 15 ° to the gloss angle measurement angle.

The perceptual, subjectively perceived color difference of two colors results in a known manner from the Euclidean distance between two points in the Lab color space. In the following table, the parameters F1 and F2 as well as E1 and E2 respectively represent the colors used in the partial areas of the color layer and the effect layer. In detail: F1: P 658 (blue) F2: P 529 (purple) E1: Iriodine lilac E2: Colorcrypt gold-green "Top view" "Effect angle" L a b L a b F1 81.58 -2.60 -7.75 85.64 -1.91 -6.91 F1 + E1 80.17 -2.68 -6.96 96,03 15.53 -19.78 F1 + E2 81.24 -0.77 -7.06 107.18 -3.84 18.36 F2 75.36 17.38 -17.26 80.09 16.81 -15.48 F2 + E1 74.87 16.43 -15.56 91.11 28.81 -25.34 F2 + E2 76,00 17.29 -14.76 102.59 7.00 12.39

As can be seen from the above table, the color impression in the measuring arrangement "top view" depends only slightly on the respective color E1 or E2 of the effect layer. Conversely, the measured Lab color value in the measuring arrangement "effect angle" depends strongly on the color of the effect layer.

Ideally, as already described above, no dependency of the measured color value on the underlying color layer 1 (F1 and F2) would be detectable in the measuring arrangement "effect angle", whereas no dependency on the color of the effect layer 2 can be detected in the measuring arrangement "top view" should. The fact that such dependencies still exist is attributable, on the one hand, to the fact that the measurements of the measuring arrangement "effect angle", as described above, were not carried out under the so-called gloss angle, but with a deviation of 15 ° thereof. By choosing optimal measuring conditions, however, improved color values are to be expected. Furthermore, the different color impressions can be optimized if the degree of coverage of the colors E1 and E2 in the subregions 2a and 2b of the effect layer 2 is optimized. Furthermore, a further optimization of the measured Lab color values can be achieved by increasing the transparency of the effect layer 2 and optimizing the orientation of the effect pigments in the effect layer 2.

• umgebende Farbschicht 3: P 528 (violett) und P 659 (blau);
• Farbschicht 1: P 611 (gelb) und P 466 (ocker);
• Teilbereich 2a: Iriodin blau (komplementärer Kontrast); und
• Teilbereich 2b: Colorcrypt gold-grün (in Harmonie).

In a second embodiment, the following colors are used:

• surrounding color layer 3: P 528 (purple) and P 659 (blue);
• Color coat 1: P 611 (yellow) and P 466 (ocher);
• Subarea 2a: Iriodin blue (complementary contrast); and
• Section 2b: Colorcrypt gold-green (in harmony).

Not only the colors used for color layer 1 are in harmony in this and the exemplary embodiments mentioned above, but also the colors used for the surrounding color layer 3, which additionally supports the binary change of information for the viewer.

In a first variant of this second exemplary embodiment, the color Iriodin lilac (complementary contrast) is used in the subarea 2a, and the color Colorcrypt gold-green (in harmony) in the subarea 2b. In a further variant, STEP colors with respectively suitable shades are provided in partial area 2a and / or partial area 2b.

Also in the second exemplary embodiment, the respective Lab color values of the different regions of the security element were quantified with the method described in connection with the first exemplary embodiment: F1: P 611 (yellow) F2: P 466 (ocher) E1: Iriodin blue E2: Colorcrypt gold-green "Top view" "Effect angle" L a b L a b F1 83.52 -5.28 53.57 88.44 -5.11 46.57 F1 + E1 81.91 -1.35 32.93 99.53 -0.35 -11.75 F1 + E2 81.19 -4.17 49.02 109.89 -5.08 61.51 F2 80.08 1.90 18,89 84,54 1.89 17.93 F2 + E1 78.76 3.10 12,00 96.06 2.84 -22.17 F2 + E2 79.64 2.09 18.67 90.92 0.78 25.55

• umgebende Farbschicht 3: P 321 (türkisblau) und P 240 (rotviolett);
• Farbschicht 1: P 129 (ockergelb) und P 164 (orangerot);
• Teilbereich 2a: Iriodin blau (komplementärer Kontrast);
• Teilbereich 2b: Colorcrypt rot-gold (in Harmonie).

In a third embodiment, the following colors are used:

• surrounding color layer 3: P 321 (turquoise blue) and P 240 (red violet);
• Color layer 1: P 129 (ocher yellow) and P 164 (orange red);
• Subarea 2a: Iriodin blue (complementary contrast);
• Section 2b: Colorcrypt red-gold (in harmony).

In a first variant of the third exemplary embodiment, the color iriodin blue (complementary contrast) is used in the subregion 2a, and the color colorcrypt gold-green (in harmony) in the subregion 2b. In a second and third variant, the color Iriodin lilac (complementary contrast) is used in the subarea 2a and the color Colorcrypt gold-green (in harmony) or Iriodin gold (in harmony) in the sub-region 2b. In a further variant, STEP colors with respectively suitable shades are provided in partial area 2a and / or partial area 2b.

Also in the first variant of the third exemplary embodiment, the respective Lab color values of the different regions of the security element were quantified with the method described in connection with the first exemplary embodiment: F1: P 164 (orange red) F2: P 129 (ocher yellow) E1: Iriodin blue E2: Colorcrypt gold-green "Top view" "Effect angle" L a b L a b F1 83.68 24,37 24.84 89.26 21.98 23.59 F1 + E1 82.87 23.71 15,95 95.71 20.13 -6.70 F1 + E2 81.86 21.66 22.79 109.97 10.98 44.31 F2 85.98 7.25 47.43 91.51 6.24 41.23 F2 + E1 84.67 10.69 29,66 97.77 9.46 1.02 F2 + E2 83.27 8.34 43.42 110.56 2.95 57.97

• umgebende Farbschicht 3: P 152 (dunkelorange) und P 186 (rot);
• Farbschicht 1: P 305 (blau) und P 319 (blaugrün);
• Teilbereich 2a: Colorcrypt gold-grün (komplementärer Kontrast); und
• Teilbereich 2b: Iriodin blau (in Harmonie).

In a fourth embodiment, the following colors are used:

• surrounding color layer 3: P 152 (dark orange) and P 186 (red);
• Color coat 1: P 305 (blue) and P 319 (blue-green);
• Subarea 2a: Colorcrypt gold-green (complementary contrast); and
• Section 2b: Iriodin blue (in harmony).

In a first variant of the fourth exemplary embodiment, the color iriodin blue (in harmony) is used in the subregion 2b, and the color colorcrypt red-gold (complementary contrast) in the subregion 2a. In a second variant of the fourth exemplary embodiment, the color iriodin gold (complementary contrast) is used in the subregion 2a and the color Colorcrypt lilac-green (in harmony) in the subregion 2b. In a further variant, STEP colors with respectively suitable shades are provided in partial area 2a and / or partial area 2b.

Also in the fourth embodiment, with the method described in connection with the first embodiment, the respective ones Lab color values of the different areas of the security element quantified: F1: P 319 (blue-green) F2: P 305 (blue) E1: Iriodin blue E2: Colorcrypt gold-green "Top view" "Effect angle" L a b L a b F1 79.03 -23.97 -9.87 83.45 -20.99 -9.52 F1 + E1 78.47 -20.59 -6.72 94.72 -14.14 -30.06 F1 + E2 80.75 -15.13 -5.33 104.17 -14.22 16.89 F2 82.33 -18.77 -14.42 85.88 -16.85 -13.55 F2 + E1 80.81 -19.22 -12.37 96.94 -13.19 -32.98 F2 + E2 81,95 -13.76 -12.98 105.52 -12.78 10,95

The following table shows the measured Lab values of the colors used in the effect layer. "Top view" "Effect angle" L a b L a b Iriodin blue 93.43 -0.07 7.40 106.52 0.63 -17.45 Colorcrypt gold-green 93.62 -0.11 3.38 112.89 -2.68 21,00 Iriodine lilac 93.60 -1.19 6.05 106.82 13.47 -6.26

For the construction of the flexographic printing ink for the effect layer of the embodiments 1 to 4, it should be noted that this is a water-based paint whose solids consist of polyacrylates and polyurethane (proportion about 40% by weight). The pigments are stirred in to about 20% by weight. When Diluent is water and used as solvent 1-methoxypropan-2-ol (together about 40 wt .-%). The composition achieves a very high gloss. In addition, as a rule, several auxiliary agents (additives) are used whose proportion is less than 1% by weight (for example wetting agents, pH neutralizers, thickeners, defoamers). The high gloss achieved for the security element with these lacquers is generally also more stable than other color ranges of the value document, eg the banknote, which has a positive effect on the verification of the security element and thus the security against counterfeiting.

The following is an example of the composition of an ink suitable for the color layer or the surrounding color layer: about 1 to 20% organic colored pigments about 0 to 20% linseed oil about 20 to 98% Binders based on hydrocarbon-modified rosin resins and mineral oil / linseed oil about 0 to 2% Wax, eg micronized PE wax about 1 to 2% Driers based on cobalt / manganese octoate about 0 to 4% Mineral oil.

Furthermore, further auxiliaries and solvents, in particular water, may be contained in the printing inks.

The application of the effect layer is carried out with a special anilox roller, which was produced in an ART process. In the ART (Anilox Reverse Technology) method of the company Praxair a special raster geometry of the anilox roller is realized by means of a special engraving technique, so that even relatively large pigments of up to about 40 microns can be processed.

In Fig. 3a the picture motif is shown, which is introduced as information in the color layer 1. In Fig. 3b the image motif is shown, which is introduced as information in the effect layer 2. The motif of the color layer 1 represents a stylized crown and thus an easily recognizable motif with a meaning for the viewer. The motif of the effect layer 2 is the value number "50", with an interference structure in the form of stripes additionally being around this value. The image motifs in both layers are thus made up of two shades in each case, namely the shades of the subregions 1a and 1b of the color layer 1 and the shades of the subregions 2a and 2b of the effect layer 2. It is understood that instead of the in Fig. 3a shown crown also other motifs, such. B a (stylized) animal (swan, rhinoceros, etc.), a (stylized) animal head (lion, bear, etc.), a (stylized) plant (palm, flower, etc.), a well-known landmark (Eiffel Tower, Brandenburger Gate, etc.) or the like can be selected. Furthermore, it is irrelevant in the image motif of the effect layer 2, in which of the two sections 2 a, 2 b of the Fig. 3b the complementary color is printed, that is a binary change of information of course also takes place when the effect color with the complementary hue in Fig. 3b filled with the reference numeral 2b area. Accordingly, the in Fig. 3b designated by the reference numeral 2a then contain the harmonic hue. Such an embodiment of the effect layer 2 is in Fig. 3c shown. The motif of the effect layer 2 in the form of the value "50" and the interference structure is formed by the subarea 2a (complementary contrast) and 2b (in harmony), the subregions 2a, 2b according to FIG Fig. 3c opposite to the subregions 2a, 2b according to FIG Fig. 3b are just reversed. Corresponding considerations apply, of course also for the assignment of the colors to the subregions 1a and 1b of the color layer 1.

In a variant of in Fig. 2 shown layer structure, the effect layer 2 is applied directly to the substrate 4 and the ink layer 1 above the effect layer 2. This is in Fig. 5 shown. In a first embodiment of this variant, the substrate 4 is transparent or at least translucent and viewing the security feature is done through the substrate 4, as shown by the arrows A 'and B'. In a second embodiment of this variant, semitransparent or opaque effect colors are respectively used for the effect layer 2 in the subregions 2a and 2b, whereas in each case highly translucent printing inks are used for the then overlying color layer 1. In this embodiment, the viewing is done directly on the security feature as before, and the substrate 4 can be opaque.

In a further variant of the exemplary embodiments shown, the partial regions 1a and 1b of the color layer 1 and / or the partial regions 2a and 2b of the effect layer 2 are not printed in shocks but are spaced apart from one another. As a result, for example, the hue of the underlying substrate 4 can be used to produce color impressions.

Finally, in Fig. 4 Yet another variant shown in which the effect layer of subarea 2a (complementary contrast) and 2b (in harmony) in the form of the further portion 20a (complementary contrast) in the region of the surrounding ink layer 3 (the data carrier 4) is arranged, preferably in more detail Passerung to the color layer 3. In the example shown, the individual lines of the subarea 20a continue in the area of the surrounding color 3, which is likewise designed as a line pattern. It understands itself, that the lines of the subregion 20a can also be arranged, for example, in exact registration on the surrounding ink layer. In principle, very different arrangements of effect layer 2 and surrounding color layer 3 are conceivable in order to reinforce the binary tilting effect in the perception of the viewer. Thus, for example, an embodiment is conceivable in which the motif of the effect layer 2 with the surrounding color layer 3 is meaningful, ie, for example, the motif of the effect layer is a sun and the rays of the sun are at least partially formed by the surrounding color layer. In any case, also in the embodiment according to Fig. 4 the binary tilting effect of the security element according to the invention increases in the perception of the viewer and thus increases the security against counterfeiting.

In a fifth exemplary embodiment, at least one of the subregions of the color layer 1 and / or the effect layer 2 exhibits a luminescence. This may be fluorescence or phosphorescence, the decay time of the emission being suitably chosen in the latter case. Furthermore, the emission and absorption behavior of the luminescent substance or substances is suitably chosen so that a desired effect is achieved.

In a first variant of the fifth exemplary embodiment, only one of the two subareas of the color layer 1 contains a fluorescent luminescent substance. Upon excitation of the luminescent substance, the motif of the color layer is reproduced and is then visible independently of the viewing angle. In this variant, the excitation light for the luminescent substance must not be weakened by the overlying effect layer 2. Since luminescent substances are typically excited by UV radiation, the overlying effect layer 2 must therefore not contain any UV absorbers. Such UV absorbers based on titanium dioxide (TiO ₂ ) included For example, the iriodine pigment rutile fine yellow or fine blue or Colorcrypt Gold Merck. Suitable effect pigments for the effect layer 2 are, for example, liquid crystal pigments or Iriodin 4504 Lava red or Colorstream F10 Autum Mystery also from Merck.

In a second variant of the fifth exemplary embodiment, both partial regions of the color layer 1 contain luminescent substances. These differ in their emission wavelengths or spectra and produce different color impressions when emitted. In this case, the first part fluoresces, for example, in the red wavelength range, while the second portion fluoresces in the blue wavelength range. Thus, in the second variant, as previously also in the first variant, the motif of the color layer 1 is refinished and for the overlying effect layer 2 suitable effect pigments must be selected which do not absorb the excitation radiation of the luminescent substances of the color layer 1.

In the first and second variant of the fifth embodiment, the effect layer 2 has no luminescent substances.

In a third variant of the fifth exemplary embodiment, precisely one of the two subregions of the effect layer 2 has a fluorescent luminescent substance. Upon excitation of the luminescent substance, the motif of the effect layer 2 is thus reproduced and is visible during the emission not only under the effect angle, but under all viewing angles. The luminescent substance or the luminescent color used as such is, in the ideal case, completely transparent and does not have its own body color, at least in the visible spectral range. The luminescent substance is thus not visually recognizable and as long as the luminescent substance does not emit, the visual perceptibility of the effect layer 2 does not change. Is the luminescent substance In contrast, the fluorescent color used is not completely transparent, it must be ensured by suitable choice of the ingredients in the other portion of the effect layer 2, that the two portions of the effect layer 2 outside the effect angle produce a sufficiently similar visual impression, so that these sub-areas do not distinguish can be. It is advantageous to use a luminescent substance which is as opaque as possible in order to minimize the perceptibility of the motif of the underlying color layer 1 as little as possible. This variant of the fifth embodiment has the advantage that the effect pigments of the effect layer 2 can be UV-absorbing and thus result in fewer restrictions for the choice of the effect pigments than in the first and second variants of the fifth embodiment.

In a fourth variant of the fifth exemplary embodiment, luminescent substances are provided in both partial regions 2 a and 2 b of the effect layer 2. These in turn differ in their emission wavelengths or spectra. In this case, a partial region in the red wavelength range fluoresces, while the other partial region of the effect layer 2 fluoresces in the blue wavelength range. Without excitation, both luminescent substances or luminescent dyes, as already described, ideally no own body color and are thus visually invisible, whereby the perceptibility of the motif of the underlying color layer 1 is maintained. If, on the other hand, there is a certain perceptibility of the luminescent substances in the effect layer even without excitation, then at least care must be taken that both subregions of the effect layer outside the effect angle produce as uniform a visual impression as possible and are as opaque as possible.

In the third and fourth variants of the fifth embodiment, the ink layer 1 has no luminescent substances.

In a fifth variant of the fifth exemplary embodiment, exactly one subarea of the color layer 1 and the effect layer 2 each comprise a luminescent substance. Both luminescent substances have the same emission color and in the simplest case the same luminescent substance can be provided in both partial regions. Upon excitation of the fluorescent luminescent substance, this results in additional third information, optionally in the form of a motif, which is composed of the two fluorescent subregions.

In a modification of the fifth variant, the two partial regions have different emission wavelengths or spectra and produce a different color impression from each other.

In further modifications of the fifth variant of the fifth embodiment, fluorescent luminescent substances can be provided in both partial regions of the color layer 1 and / or effect layer 2 in different wavelength ranges. In these variants, if necessary, the restrictions already discussed with regard to the choice of the ingredients of the effect layer should be taken into account.

In a sixth variant of the fifth exemplary embodiment, a fluorescent luminescent substance is provided in a partial region of the ink layer 1, while a phosphorescent luminescent substance is provided in the other partial region of the ink layer 1. The effect layer 2 contains no luminescent substances. Both luminescent substances of the color layer 1 are chosen so that they produce an identical color impression upon excitation and in particular show the same emission color at the same intensity, so that the color layer 1 appears as a closed surface during the excitation. After switching off the excitation, the corresponding subregion of the color layer is perceptible during the decay time of the phosphorescent luminescent substance. In other words, the motif of the ink layer 1 can be seen during the decay time of the phosphorescent luminescent substance. In this case, one subregion of the color layer 1 is, for example, yellow fluorescent, while the other subregion of the color layer 1 is yellow phosphorescent. Also in this case, the overlying effect layer 2 ideally contains no substances which absorbs the excitation radiation for the luminescent substances of the color layer 1.

Phosphorescent luminescent substances have the advantage that they are particularly suitable for machine selection, whereas in particular iriodin colors turn out to be due to their color change, that is to say due to the tilt effect between ideally complete transparency in plan view and the iridescent color impression when viewed under the effect angle Machine selection less suitable.

In a seventh variant of the fifth exemplary embodiment, the fluorescent and phosphorescent luminescent substances are provided in the two subregions of the effect layer 2. The color layer 1 has no luminescent substances. In this seventh variant, essentially the same effects as with the sixth variant described above can be achieved, whereby here too there are fewer restrictions in the selection of the effect pigments of the effect layer 2 (as already described above).

In an eighth variant of the fifth exemplary embodiment, a fluorescent luminescent substance is provided in a partial region of the color layer 1 and in a partial area of the effect layer 2 a phosphorescent luminescent substance. The respective other subregions of color layer 1 and effect layer 2 have no luminescent substances. The intensity of the fluorescent luminescent substance in the color layer 1 is significantly higher than the intensity of the phosphorescence of the luminescent substance in the effect layer 2. During the excitation, the emission of the fluorescent subregion of the color layer 1 thus dominates. Thus, the motif of the color layer 1 is recognizable during the excitation. After switching off the excitation, the motif of the effect layer 2 can be seen during the decay time of the phosphorescence in the effect layer 2. Thus, when the excitation is switched off, a motif change takes place from the motif of the color layer 1 to the motif of the effect layer 2.

Alternatively, the high-intensity emitting fluorescent luminescent substance may also be provided in the effect layer 2, while the lower-intensity phosphorescent luminescent substance is provided in the color layer 1.

Furthermore, alternatively, instead of a fluorescent and a phosphorescent luminescent substance, it is also possible to provide two phosphorescent luminescent substances which have a significantly different cooldown from each other. Thus, after switching off the excitation in a first phase, the motif of that layer can be seen in which the more strongly emitting phosphorescent luminescent substance with a shorter cooldown is located, while in a later phase the motif of that layer can be seen in which the phosphorescent luminescent substance with the longer Cooldown is, which also takes place in this case, a motif change between color layer 1 and effect layer 2.

In a ninth variant of the fifth exemplary embodiment, a first luminescent substance is provided in a partial region of the color layer 1 and a second luminescent substance in a partial region of the effect layer 2. Both luminescent substances differ in their excitation spectrum such that they can be selectively applied. For example, one of the luminescent substances can be excited with short-wave light, while the second luminescent substance can be excited with long-wave light. Nevertheless, both excitation spectra can be in the UV range. Depending on the selected excitation, the motif of the color layer 1 or the motif of the effect layer 2 can thus be made selectively perceptible.

Of course, the various illustrated variants of the fifth embodiment may be suitably combined with one another to produce a desired effect.

In a sixth exemplary embodiment, at least one partial area of color layer 1 or effect layer 2 contains an infrared-absorbing and emitting substance (referred to below as infrared absorber). This infrared absorber is ideally not visually recognizable in the visible spectral range.

In a first variant of the sixth embodiment, a partial region of the ink layer 1 contains such an infrared absorber. The other part of the color layer and the effect layer 2 contain no infrared absorber. Accordingly, with suitable infrared excitation, the motif of the color layer 1 can be detected and evaluated by means of an infrared camera (for example an infrared converter camera). Alternatively, the infrared absorber can also be provided only in a partial area of the effect layer 2 and then the motif of the effect layer 2 can be made recognizable.

The same considerations apply to the selection of the substances for the infrared absorber as in the selection of the luminescent substances in the fifth embodiment, according to which the visual perceptibility of color layer 1 and effect layer 2 is not or only slightly affected.

In a second variant of the sixth exemplary embodiment, a first infrared absorber is provided in a partial region of the ink layer 1, and a second infrared absorber is provided in a partial region of the effect layer 2. In the other parts of the color layer 1 and effect layer 2 no infrared absorber are provided. Both infrared absorbers differ in their excitation wavelength. Accordingly, by suitable selection of the excitation wavelength, the motif of the color layer 1 or the motif of the effect layer 2 can be detected selectively with an infrared camera. For selective excitation, an infrared cut filter can be used, which is tuned to the respective excitation wavelength of the infrared absorber to be excited. Alternatively, it is also possible to choose two infrared absorbers having different emission wavelengths, so that the motif of the color layer 1 or the effect layer 2 can be selectively made visible with an infrared camera by means of, for example, an infrared stop filter matched to the respective emission wavelength of the motif to be selected ,

Furthermore, the possibilities of variation discussed in connection with the fifth embodiment can also be applied mutatis mutandis to the sixth embodiment.

In a seventh embodiment, thermochromic inks are provided in color layer 1 and / or effect layer 2, which in a predetermined Temperature range become transparent or invisible and outside of this temperature range have a body color.

In a first variant of the seventh embodiment, one of the two partial areas of the color layer consists of a thermochromic color. The other part of the color layer and the effect layer 2 have no thermochromic colors. In the predetermined temperature range of the thermochromic color, therefore, one part of the color layer 1 becomes transparent, and in this partial area the color impression is determined by the underlying substrate.

In a second variant of the seventh embodiment, both subregions of the color layer 1 consist of different thermochromic colors, with the predetermined temperature ranges of the two thermochromic colors, in which they become transparent, at least overlapping and ideally equal. When setting a temperature from this overlap region thus the entire color layer 1 is transparent and in this area, a uniform color impression is generated outside the effect angle of the overlying effect layer 2 by the underlying substrate 4. At such a temperature, because of the now uniform background, the perceptibility of the information of the effect layer 2 improves when viewed under the effect angle.

If thermochromic inks are provided in the color layer 1, as is the case in the first and second variant of the seventh exemplary embodiment, the thermochromic colors ideally have body colors which have a sufficiently high luminosity to make the motif of the color layer 1 recognizable.

In a third variant of the seventh exemplary embodiment, one or both subregions of the effect layer 2 additionally have one or different thermochromic colors. Only when setting a temperature at which the thermochromic colors of the effect layer 2 become transparent, is then the observation of the previously described binary tilt effect, d. H. the change of motif between the motif of the color layer 1 and the motif of the effect layer 2 by changing the viewing angle possible. In other words, the effect of the effect layer 2 is hidden outside the predetermined temperature range. If both subregions of the effect layer 2 have the same thermochromic color, then the security element appears outside the predetermined region as a uniform, continuous surface. If two different thermochromic colors are selected for the two subregions of the effect layer 2, the motif of the effect layer 2 outside the predetermined range of thermochromic colors can be recognized under all viewing angles.

In a fourth variant of the seventh exemplary embodiment, a partial area of the color layer 1 and a partial area of the effect layer 2 are each provided with thermochromic colors. Also in this case, the binary tilt effect is visible only when setting a suitable temperature. In other words, the corresponding portion of the color layer 1 is transparent in the predetermined temperature range and is opaque outside the predetermined temperature range of the thermochromic color, while in the portion of the effect layer 2 outside the predetermined temperature range of the thermochromic color of the effect layer 2, the body color of the thermochromic color is visible and within the predetermined temperature range is transparent and thus the viewing angle-dependent effect of the effect layer 2 is perceptible.

In an eighth embodiment, a partial area of the color layer consists of two subregions 1aa and 1ab, as shown in FIG Fig. 6 is shown. Both partial areas add up to the partial area 1a, as is known from the other exemplary embodiments. Both sub-areas 1aa and 1ab consist of two metameric colors. These generate an identical color impression upon exposure of a first light source, for example with white standard light D65, and are thus recognized as a uniform region. When viewed with a second light source, such as incandescent light, the two subregions 1aa and 1ab produce different color impressions. This feature can be used as an authenticity feature whose presence is not readily apparent.

In a ninth exemplary embodiment, only one of the partial regions or both partial regions of the effect layer 2 is exposed to a marking substance, wherein, for example, its sole presence can serve as a proof of authenticity. Such markers or marker pigments are, for example, markers, hologram flakes or luminescent substances.

In a tenth embodiment, at least one of the partial areas of the color layer 1 or the effect layer 2 contains a cholesteric color. This at least one subregion is recognizable when viewed with a suitable polarization filter, optionally as a function of the orientation of the polarization filter.

In a first variant of the tenth embodiment, both subregions of the color layer 1 consist of cholesteric colors which in each case generate different polarizations. The effect layer 2 contains no cholesteric color. When viewed with the naked eye, this difference in the polarization of the light emitted by the color layer 1 is not visible. It only becomes visible when viewed using a suitable polarizing filter.

In a second variant of the tenth embodiment, both partial regions of the effect layer 2 each contain a cholesteric color. The two colors consist of cholesteric liquid crystal pigments, the helix of both cholesteric colors being different. When viewing the effect layer 2 using a suitable polarization filter or a so-called STEP-Watchers, the subregions of the effect layer 2 become visible or invisible.

In an eleventh embodiment, 2 magnetic pigments are provided in the effect layer.

In a first variant of the eleventh exemplary embodiment, only one of the two subregions of the effect layer 2 is equipped with a machine-readable magnetic pigment.

In a second variant of the eleventh embodiment, both portions of the effect layer 2 are equipped with the same magnetic pigment. This results in the sum, corresponding to the area of the effect layer 2, a large, machine-readable area.

In a third variant of the eleventh exemplary embodiment, one subregion of the effect layer 2 is provided with a soft magnetic magnetic pigment, while the other subregion of the effect layer 2 is equipped with a hard magnetic magnetic pigment. This results in a machine-readable code or a machine-readable pattern.

Magnetic pigments generally have a slightly opaque body color, that is, an intrinsic color. In order to obtain a color impression of the underlying color layer 1 that is uninfluenced by the overlying effect layer 2 when the security element is viewed outside the effect angle of the effect layer 2, an identical intrinsic coloration is provided in both subregions of the effect layer 2. This is particularly necessary if, as in the first variant of the eleventh embodiment, only a portion of the effect layer 2 is provided with magnetic pigments or if, as in the third variant of the eleventh embodiment, different magnetic pigments are provided in the two subregions of the effect layer 2 , One possibility for adjusting the intrinsic color is to additionally provide suitable organic pigments in one of the subregions. Alternatively, this can also be achieved with TiO ₂ pigments.

As already mentioned, in at least one of the two subregions of the effect layer 2, a mixture of a pigment exhibiting an optically variable effect and e.g. an iriodin silver pigment. Such a mixture may e.g. have the composition mentioned above for the effect layer of the embodiments 1 to 4:

This in Fig. 3a illustrated motif of the color layer 1 is only one of many possible motifs that can be used both for color layer 1 and for the effect layer 2. In Fig. 7 is another example of a motif of the color layer 1, which advantageously with the in Fig. 3b shown motif of the effect layer 2 can be combined, a star shown. Accordingly, all so far in connection with the subject Fig. 3a described effects and advantages also by a color layer 1 with a motif as in Fig. 7 achieved reached.

The various embodiments and their variants can all be combined with each other. Thus, it is possible, for example, to provide both magnetic pigment and luminescent substances in ink layer 1 and effect layer 2.

Claims (15)

1. A security element for a data carrier, comprising an ink layer (1) and an effect layer (2), wherein the effect layer (2), upon viewing from a first angle (A), is substantially transparent and, upon viewing from at least one second, so-called effect angle (B) shows a color tone, and wherein the effect layer (2) comprises single-layer or multi-layer interference pigments or cholesteric liquid crystal pigments, characterized in that the ink layer (1) comprises at least two partial areas (1a, 1b) with different color impressions, wherein the color tones of the different color impressions of the two partial areas contain the same primary color and thus are in harmony with each other and wherein the two partial areas preferably differ by the screening or by the color tone of the applied ink layer and that the color tone of the effect layer (2) produces at least in a first partial area (2a) a complementary contrast to the color tones of the ink layer (1).
2. The security element according to claim 1, characterized in that from the effect angle the effect layer shows in a second partial area (2b) a color tone which contains the same primary color as the color tone of the ink layer and thus is in harmony with the color tone of the ink layer.
3. The security element according to any of claims 1 or 2, characterized in that the ink layer (1) and/or the effect layer (2) are applied all-over.
4. The security element according to claims 1 to 2 or 1 to 3, characterized in that the ink layer (1) comprises first information, in particular a first motif, which comprises the at least two partial areas of the ink layer, and that the effect layer (2) comprises second information, in particular a second motif, which comprises at least the first and second partial area of the effect layer, wherein the ink layer (1) and the effect layer (2) are disposed preferably congruently one above the other.
5. The security element according to claim 4, characterized in that an outline of the ink layer (1), of the effect layer (2) and/or of partial areas (1a, 1b, 2a, 2b) of the ink layer or effect layer at least partly corresponds to a gap in a surrounding further ink layer (3) and preferably abuts the surrounding ink layer.
6. The security element according to claim 5, characterized in that the surrounding further ink layer (3) comprises at least two partial areas (3a, 3b) with different color impressions, wherein the color tones of the different color impressions of the at least two partial areas contain the same primary color and thus are in harmony with each other.
7. The security element according to any of claims 1 to 6, characterized in that at least one color tone of the ink layer (1) is a secondary or tertiary color.
8. The security element according to any of claims 1 to 7, characterized by an embossing in the area of the effect layer (2).
9. The security element according to any of claims 1 to 8, characterized in that at least one partial area of ink layer (1) or effect layer (2) contains at least one further substance, in particular a luminescent substance, an infrared absorber, a thermochromic ink, a marking substance, a cholesteric ink and/or a magnetic pigment, wherein preferably one partial area of ink layer (1) and effect layer (2) in each case contains one further substance and the two partial areas complement each other to third information, in particular to a third motif.
10. The security element according to any of claims 1 to 9, characterized in that at least one of the partial areas of the ink layer (1) is formed by two inks metameric to each other.
11. The security element according to any of claims 2 to 10, characterized in that one partial area of the effect layer (2) appears matt and the other partial area of the effect layer glossy.
12. A data carrier comprising a security element according to any of claims 1 to 11.
13. A method for manufacturing a security element, comprising the steps:

    - providing a substrate (4);

    - applying an ink layer (1) which comprises at least two partial areas (1a, 1b) with different color impressions, wherein the color tones of the different color impressions of the two partial areas contain the same primary color and thus are in harmony with each other and wherein the two partial areas preferably differ by the screening or by the color tone of the applied ink layer; and

    - applying an effect layer (2) which comprises single-layer or multi-layer interference pigments or cholesteric liquid crystal pigments and upon viewing from a first angle is substantially transparent and upon viewing from at least one second, so-called effect angle shows a color tone, which at least in a first partial area (2a) produces a complementary contrast to the color tones of the ink layer.
14. The method according to claim 13, characterized in that the application of the ink layer (1) and the application of the effect layer (2) are in each case partial operations in one joint printing operation and/or that the application of the ink layer (1) is effected by offset printing or indirect relief printing and the application of the effect layer (2) by flexographic printing.
15. The method according to any of claims 13 to 14, characterized by the step of applying a further surrounding ink layer (3), preferably by offset printing or indirect relief printing method in a super-simultaneous printing apparatus.

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