Security element with identification marks

The invention relates to a security element for protecting valuables, having an individualizing mark. The invention also relates to a data carrier having such a security element and a manufacturing method for such a security element.

Media as value or identification documents, as well as other valuables, such as branded products, to hedge often provided with security elements that permit verification of the authenticity of the data carrier and which serve as protection against unauthorized reproduction.

A special role in safeguarding authenticity play security elements having viewing-angle-dependent effects, as they can not be reproduced even with the most modern copiers. The security elements are equipped for example with optically variable elements, convey to the viewer at different viewing angles a different image impression and show, for example, depending on the angle a different color or brightness impression and / or another graphic motif.

Proceeding from this, the present invention seeks to provide a security element of the type mentioned with high imitation security and an attractive visual appearance, which can be ideally easily checked by laymen for authenticity.

This object is solved by the features of the independent claims. Further developments of the invention are the subject of the dependent claims.

According to the invention includes a security element of the type mentioned<ul><li>an optically variable effect layer that conveys different color effects at different viewing angles,</li><li>an optically non-variable color layer covers at least in a region of overlap of the effect layer, and there includes at least a first portion with a first solid color impression and a second portion with a different second fixed color effect, and</li><li>a generated at least in the overlapping area of ​​effect layer and color layer individualising marking, showing the first and second solid color impression in each case in a partial region,</li><li>wherein the partial areas of the color layer and the effect layer are so matched to one another such that the variable color impression of the effect layer corresponds to less than a predetermined first viewing angle the first fixed color impression.</li></ul>

The term "solid color impression" denotes a color impression that does not change with the viewing angle. Conventional printing inks generally have to such a solid color impression. In contrast, a color impression that changes with the viewing angle, such as the color-shift effect of the optically variable layer. Such, varying with the viewing angle color impression is called "variable color impression" in this description. The term "variable color impression" in the present invention includes each with the viewing angle changing and by an observer perceptible impression of color. Besides the aforementioned color shift can be perceived by an observer, viewing-angle-dependent brightness or contrast change such a "variable color impression" but also eg.

By inventively made ​​vote the first portion of the label to the viewer from the first viewing angle appears with the same color impression as the effect layer and is therefore hidden. Is recognizable from the first viewing angle, however, the second portion of the label, which shows a different solid color impression and therefore contrasting apart from the effect layer. From other angles also the first portion of the marking can be seen as an integral color impression then aufgr no longer matches and the change in the variable color impression of the effect layer with the color impression. The first predetermined viewing angle, for example, correspond to a vertical view of the security element. It is understood that the inventive principle will not leave when the effect layer and a portion at a certain viewing angle does not have exactly the same color impression, but the viewer of the color impression of effect layer and the sub-region appears the same although the color impression of the subregion and the effect layer only are substantially equal. For the inventive concept therefore is ultimately crucial that the viewer perceives the color impression of a certain portion and the color of a layer effect as the same, there is no requirement on an exact match in terms of a definition of a particular color space. As far as is discussed in the present application by the same or same color impression of two regions of the security element of this invention thus include these formulations also a color impressions of two areas which are substantially equal.

Also, it is understood that the inventive security element can have a plurality of areas in which an inventive optically variable effect and a layer according to the invention not optically-variable ink layer with at least two subregions with first and second fixed color effect are present. Conceivable example is a security element having a first effect layer and an optically non-variable color layer having first and second partial region having in a first region, said first portion a first fixed color effect and the second portion provides a second solid color impression. In a second region of this security element a second optically variable effect layer is disposed, which is combined with a further optically variable ink layer with two portions and two fixed color impressions, the color impression of first and second optically variable effect layer and of the respectively associated sub-areas different can be. Also, the first and second optically variable effect layer and the associated sub-regions may have different structures according to the invention.

Preferably, the partial areas of the color layer and the effect layer are even coordinated such that the variable color impression of the effect layer corresponds to less than a predetermined second viewing angle the color impression of the second solid. The second predetermined viewing angle may for example correspond to an oblique view of the security element. In this case, only the second portion of the marking is visible when viewed vertically, while at oblique viewing only the first portion of the label is visible. The respective other portion remains hidden to the effect layer to the viewer due to the color match.

According to an advantageous variant of the invention, the effect layer opaque or semitransparent is formed. The marking is in particular formed in this variant by recesses of the effect layer or. By local, produced by the action of laser radiation, transparent modifications of the effect layer The recesses or the transparent modification areas give each locally free view to the arranged below the effect layer color layer.

According to another, likewise advantageous variant of the invention, the effect layer is substantially transparent. In this variant, a laser-sensitive covering layer is intermediate between the effect layer and the color layer is arranged and the marking is formed by recesses or local transparent modifications of the intermediate layer which are respectively generated by the action of laser radiation. In the not acted upon by laser radiation areas then the effect layer is present in the context of covering intermediate layer, while is released locally in each case to look at the arranged below the effect layer and the intermediate layer color layer through the openings or transparent modification areas in the applied areas.

It is understood that the variant described above with substantially transparent trained effect layer and a laser-sensitive, opaque interlayer between the effect layer and a layer of ink is basically also be designed with an effect layer does not absorb the laser radiation and semitransparent or even executed nationwide. As described above, the intermediate layer is provided by recesses or local, transparent modifications, so that in turn results in interesting color shift according to the invention for the viewer by the application of laser radiation.

The optically variable appearance of the effect layer is especially attractive when the opaque interlayer is dark, especially black. The intermediate layer may, for example, in a transparent binder an IR absorber, such as carbon black CIPB1. 7 or graphite included, which is ablated with an infrared laser at laser impingement. Other suitable materials for the laser-sensitive covering intermediate layer, particularly the candidate absorbing mixture components, can the publications<patcit id="pcit0001" dnum="WO2005108110A1"><text>WO 2005/108110 A1</text></patcit>. <patcit id="pcit0002" dnum="DE102008049512A1"><text>DE 10 2008 049 512 A1</text></patcit> and <patcit id="pcit0003" dnum="DE102006008247"><text>DE 10 2006 008 247</text></patcit> are removed, the disclosures of which are incorporated to this extent in the present description.

In a further advantageous variant of the invention, the effect layer essentially is transparent and covers the ink layer itself, at least one laser-sensitive color mixture, as for example in the publications mentioned <patcit id="pcit0004" dnum="DE102008049512A1"><text>DE 10 2008 049 512 A1</text></patcit>. <patcit id="pcit0005" dnum="DE102006008247"><text>DE 10 2006 008 247</text></patcit> and <patcit id="pcit0006" dnum="WO2005108110A1"><text>WO 2005/108110 A1</text></patcit> is described. The marking is in this embodiment formed by local color changes in the laser-sensitive color mixture, which are generated by the action of laser radiation. For example, the color mixture containing first and second colored pigments, wherein the second colored pigments are present in a variety of core-shell particles whose shell is respectively surrounded by a ablationsfördernden functional layer, as in the<patcit id="pcit0007" dnum="DE102008049512A1"><text>DE 10 2008 049 512 A1</text></patcit> described. Through laser application then the second colored pigments may be removed from the color mixture, so that the color impression is determined in the marked areas only by the first pigments. To generate various solid color impressions, different first colored pigments can be provided in various parts of the ink layer, or the color mixture can contain multiple, removable at various laser intensity colored pigments.

In a preferred embodiment of the invention, the ink layer shows a gradient between the first and second solid color impression. Such a gradient can be generated for example by a plurality of color elements having different colors. In a particularly rationalizing gradient there is produced by a plurality of juxtaposed first and second color elements, each showing the first and second solid color impression, and vary their surface portions spaced to produce a quasi-continuous gradient from the first to the second color impression. In the first and second color elements may in particular be juxtaposed color stripes or dots.

Of course, it is in principle also conceivable that is produced, for example, an optically non-variable ink layer with three color impressions a gradient between the first and second and between the second and third color impression in that by means of the method described above, a color gradient between the respective fixed color impressions is produced. At present, however, the embodiments described above with gradient between the first and second solid color of a coat of paint with two subregions due to the ease of manufacture and the resultant for the viewer impressive Kippeffektes are particularly preferred.

It is also conceivable an embodiment in which the non-optically variable ink layer in addition, a further security feature, such as micro text which, which can be additionally used, for example in the range of individualisation as an authenticity feature.

Further, it is conceivable that an effect layer having an optically variable diffraction structure, which shows the variable color impression of the present invention due to their specific diffraction structures.

In all designs, the color layer and / or effect layer can have a feature substance, in particular a magnetic, electrically conductive, luminescent or infrared-absorbing feature substance, included. If an intermediate layer is provided, these may include such a feature substance.

The optically variable effect layer preferably contains one or more layers interference pigments or cholesteric liquid crystal pigments.

Such interference pigments have, as also determined in the context of this invention usable surface layer structures, optically effective interference layers. Such interference layers typically have a thin-film structure and include, for example, in the case of a multilayer thin-film structure, a reflective layer, an absorber layer and one or more intervening dielectric spacer layers and are for example based on mica, SiO₂ or Al₂O₃, Such interference layers are designated according to the number of dielectric layers as one or more layers. 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 for example are also under the name OVI^® sold by the company SICPA.

Also effect layers with holographic pigments or pigments with a constant diffraction structure are contemplated. Holographic pigments can be especially prepared by the crushing of holographic films. You can be both transparent and opaque performs.

In one development of the invention, the individualized identification outside the coverage area is continued, notably through a local change in a standard color or a local change of a substrate, for example, by foaming or blackening of the substrate. The labeling or the security element can be integrated into the design of the data carrier on which the security element is applied. Such continuation of identification in the surrounding media is particularly well realized if the security element, such as the invention proposes, is individualized subsequently. In general, the individualized identification can outside the coverage area and thus be continued, that outside the coverage area of ​​a part of the marking is already arranged. Typically, problems persist with such a continuation of the individualizing mark register variations in the production, so that the embodiment described earlier with continuation of identification in the surrounding media by subsequent individualization is especially preferred.

The individualizing identification can be performed rasterized in advantageous embodiments of the invention and preferably represent a rasterized grayscale image or a rasterized color halftone.

The color layer and the effect layer may be coated at least in the overlapping area with a layer of varnish, which compensates for various matt or gloss effect in the field of labeling. In this way it can be avoided that label parts that are to be actually vorborgen because of their color match with the effect layer of a certain viewing angle, but can be detected due to different matt or gloss effect.

can be avoided even by certain additives in the optically-variable ink layer that marking parts that should actually be hidden because of their color match with the effect layer of a certain viewing angle, are nevertheless recognized by the viewer under certain illumination and observation conditions. These additives can be, for example, silvery pigments which impart the optically-variable ink layer a shimmering color impression that is the color impression of arranged above the optically variable effect layer approximated very well with eg also shimmering, optically variable pigments. In other words, the viewer's eye is distracted by the shimmer and sparkle of the subject areas of the possibly existing slight deviation of the color impressions, whereby the subjectively perceived by the viewer color impressions of these areas are the same.

The portions of the marking of the first and second color impression preferably represent related or complementary information. For example, the information of the first subregion repeat the information of the second portion or complement to an overall information.

Advantageously, the security element comprises a substrate on which the color layer, an intermediate layer may be planned, and the effect layer are arranged in this order. As the substrate material is any type of paper into consideration, in particular cotton paper or paper, which contains a proportion x polymeric material in the range of 0 &lt;x &lt;100% by weight. Next, the substrate material can also be a plastic film, such as a polyester film be. Such a film may be monoaxially or biaxially stretched. The stretching of the film leads, among other things, that they obtained polarizing properties, which can be used as a further security feature. Since the inventive security element is designed for viewing in plan, the substrate is preferably opaque. Of course, also a transparent or translucent substrate may be used, for example when the non-optically variable ink layer is made opaque, or the security element is laid on a reflecting, in particular white substrate. In such a transparent or translucent substrate may also be a plastic film, which is arranged in the region of a window-like perforation in a data carrier. At present, however, opaque or substantially opaque substrate materials for the security element are preferred since the security element according to the invention for the viewer, for example, due to their higher color saturation are typically attractive.

The invention also includes a data carrier with a security element of the kind described. The data carrier may be in particular a value document, such as a banknote, in particular a paper banknote, a polymer banknote or a film composite banknote act, but also an identification card such as a credit card, a bank card, a cash card, an authorization card, act an identity card or a passport personalization page.

The individualizing identification is continued with advantage over the security element out into the media. This can be done, for example, by foaming or blackening of the disk substrate or by changing a present on the data carrier layer, such as the local change of a color layer or the Demetallisation a metal layer. By subsequent individualization by laser application this continuation can be carried out in perfect register.

The invention further relates to a method for manufacturing a security element for protecting valuable objects, in which<ul><li>a substrate is provided,</li><li>an optically non-variable color layer is applied which contains at least in a region of overlap a first portion with a first solid color impression and a second portion with a second solid color impression,</li><li>an optically variable effect layer is applied, which imparts different color impressions at different viewing angles, and which covers the optically-variable ink layer in the covering area, </li><li>wherein the partial areas of the color layer and the effect layer are so matched to one another such that the variable color impression of the effect layer corresponds to less than a predetermined first viewing angle the color impression of the first solid, and</li><li>an individualizing mark is generated at least in the overlapping area of ​​effect layer and color layer in a portion showing the first and second solid color impression respectively.</li></ul>

The individualizing identification is preferably carried out by laser application, in particular with an infrared laser such as a CO₂Lasers, Nd: YAG laser or Nd: YVO₄produces laser. The individualizing identification is advantageously produced after the production of the sequence of layers of substrate, color layer and effect layer in a separate manufacturing step.

The individualization by laser application permits subsequent individualization of the security element, so that the information individualising the time of manufacture of the layer sequence is not to be known. Rather, the individualization can be carried out on a particular document of value only later, such as during the application of the security element. In this example, the serial number of a bill are detected over a reader and the read serial number is written as individualizing identification in the security element. Even with personalizing, the marking of the area of ​​the security element also continued accurate register in the surrounding media, and thus the counterfeit security of the system security element / data carrier can be further increased.

The color layer and / or the effect layer are preferably applied in a printing process. More preferably, both layers are printed. The effect layer can in principle with all common printing methods such as screen printing, flexographic, gravure and intaglio printing, applied. Preferably, however, is currently a screen or flexographic printing. Also, the gravure printing process is particularly advantageous in particular for plastic film-based substrates with and without pressure acquisition layer.

The various sections of the optically non-variable color layer may also be applied in principle with almost all common printing processes. Preferably, however, the offset printing method is used, wherein the application of the color layer in wet offset, dry offset, and most preferably can be effected in indirect letterpress printing. Advantageously, the indirect high-pressure process for the ink layer and the flexographic printing for the effect layer are applied in a printing process, which then includes, for example, three partial pressure steps (two partial printing steps for the ink layer, a part of the printing step for the effect layer).

Is a laser-sensitive covering intermediate layer is provided, it is also printed with advantage, whereby the above-mentioned printing processes can be used. With particular advantage, therefore all layers of the layer composite produced by printing processes, while the individualization is carried out by laser application.

As described, the individualization by laser application in the present invention is preferred, in principle, an inventive security element but also by a printing process, in particular by inkjet printing, laser printing or thermal transfer printing, be individualized. Namely, it is with this method difficult to generate interference layers with sufficient evenness of layer thickness, but it is possible to print on an existing interference layer pigments or dyes such as absorption, and thereby make a desired customization of the security element.

It is also conceivable in principle, at an inadequate covering power of the color layer and / or effect layer on a substrate in predetermined regions apply an opaque white layer and subsequently to arrange the ink layer, if appropriate, the intermediate layer and the effect layer thereover. Such opaque white layer can be applied by means of known printing methods with relatively high register accuracy on the substrate, with opaque white resulting in a large color saturation in the finished security element in the fields.

In a preferred embodiment, the security element with the inventive layers and individualizing mark on a film, in particular a plastic film is produced and transferred the security element thus produced by hot or cold foil application (hot or cold foil transfer process) as a foil strip or foil patch on the target substrate. Naturally, it is also conceivable that produced by an appropriate method according to the invention the layers on an intermediate carrier and only films of the invention be transferred to the target substrate.

In a further alternative embodiment, it is further provided that the optically non-variable color layer is disposed on a target substrate and the optically variable effect layer is transferred onto the color layer by means of a suitable transfer method of forming the security element according to the invention. As a transfer method turn hot or cold foil transfer process and similar techniques can be used.

It is understood to be that in the transfer method described above if needed, intermediate layer between the effect layer and color layer either transferred to the entire security element to the target substrate or disposed on the ink layer or transferred with effect layer on the color layer.

Furthermore, it should be mentioned that the optically non-variable color layer may include an additive which promotes the generation of individualized marking by ablation, in particular, laser ablation, by training by electromagnetic radiation, in particular laser application, a release liner to effect layer upon application. In such an additive may be, for example at low temperatures melting waxes, especially carnauba act.

Correspondingly, the effect paint containing an additive which, advantageously reduces the binding forces to optically-variable ink layer in generating the individualized marking by ablation, in particular laser ablation. Even with the additive effect of the color it may be, for example at low temperatures melting waxes, especially carnauba act.

Naturally, it is also conceivable that the optically variable ink layer and the effect layer contain a complete ablation-promoting additive, as described above.

Further exemplary embodiments and advantages of the invention are explained in reference to the figures, has been omitted in which a depiction to scale and proportion play to improve their clarity.

Show it:<dl id="dl0001"><dt>Fig. 1</dt><dd>a schematic representation of a banknote with a security element according to the invention,</dd><dt>FIG. 2</dt><dd>the visual appearance of the security element <figref idrefs="f0001">Fig. 1</figref>, In (a) when viewed vertically and in (b) when viewed obliquely,</dd><dt>Fig. 3</dt><dd>in (a) and (b) each schematically illustrate a cross-section of the security element of the <figref idrefs="f0001">FIG. 2</figref> for explaining the layer structure and the conclusion of the digital information exchange,</dd><dt>FIGS. 4-7</dt><dd>Various advantageous modifications of the security element of the <figref idrefs="f0002">Fig. 3</figref>.</dd><dt>Fig. 8</dt><dd>a security element according to another embodiment of the invention schematically in top view, </dd><dt>Fig. 9</dt><dd>a gradient for use in the security element of the <figref idrefs="f0004">Fig. 8</figref>and</dd><dt>Fig. 10</dt><dd>a cross-section through the security element of <figref idrefs="f0004">Fig. 8</figref> taken along the line XX.</dd></dl>

The invention will now be explained using the example of security elements for banknotes. <figref idrefs="f0001">Fig. 1</figref> shows a schematic diagram of a banknote 10 with an inventive security element 12. The security element 12 shows an optically variable appearance and is also a banknote distinguishing mark 14 provided on the depending on the viewing angle, only one portion is recognized.

When individualising identification marking 14 may be for example, the serial number or a repetition of the denomination 15 of the bill. In the embodiment, the individualized marking 14 the simple presentation sake by the code "3456" formed.

For illustration only partial visibility of the marking 14 from different viewing directions shows <figref idrefs="f0001">FIG. 2</figref> in (a) the visual appearance of the security element 12 when viewed vertically and in (b) when viewed obliquely at an angle of for example approximately 45 °.

The marking 14 comprises two sections 16,18, each having a different solid color impression. As explained above, the term "solid color impression" while a color impression, which does not change with the viewing angle, while changing the viewing angle color impression is called "variable color impression", the term "variable color impression" also as brightness includes or contrast changes.

The marking 14 has, in its first portion 16 which is formed in the shape of the digits "34", the solid color impression Green on, and in its second portion 18 which is formed in the shape of the digits "56", the solid color impression Magenta.

The surrounding region 20 of the marking 14 is not solid color impression, but has a color shift with a variable color impression that changes in the embodiment of magenta when viewed vertically to green when viewed obliquely.

When in <figref idrefs="f0001">Fig. 2 (a)</figref> illustrated vertical viewing match the solid color impression Magenta of the subregion 18 and the variable color impression Magenta of the surrounding region 20, while the portion 16 is in sharp contrast to the surrounding region 20 with its solid color impression Green. A viewer therefore sees when viewed vertically, only the digits "34" of the green portion 16 in front of a uniform magenta background 18, 20th

Upon oblique viewing at an angle of 45 °, as in <figref idrefs="f0001">Fig. 2 (b)</figref> illustrates, consent to the solid color impression identical green of the subregion 16 and the variable color impression green of the surrounding region 20, while now the portion 18 forms a clearly perceptible contrast to the surrounding region 20 with its solid color impression Magenta. A viewer therefore sees when viewed obliquely, only the digits "56" of the portion 18 in magenta against a uniform green background 16, 20th

When switching back and forth presents the security element 12 to the viewer as a digital information exchange between the partial information "34" and "56", and thus enables easy verification by laymen. the viewer tilts the security element 12 rapidly back and forth, so is due to the persistence of the human eye and the gradual color change of the color-shift effect, the entire marking "3456" visible.

The layer structure of the security element 12 and the emergence of the digital information exchange are now on related <figref idrefs="f0002">Fig. 3</figref> explained in more detail.

<figref idrefs="f0002">Fig. 3 (a)</figref> schematically shows a cross section of the security element 12 in the area of ​​identification 14. The security element 12 comprises a substrate 30 which may be formed for example by a film, but also by the banknote paper of the banknote 10 itself. On the substrate 30 is an optically variable non-color layer 32 is first printed, which contains a first portion 34 with the fixed color impression of magenta, and a second portion 36 with the fixed color impression green.

On the color layer 32, a laser-sensitive, black intermediate layer 38 and printed on the intermediate layer 38 is a transparent, optically variable effect layer 40, which 38 shows the desired color shift of magenta when viewed vertically to green when viewed obliquely against the background of the black intermediate layer.

After the preparation of the said layer sequence were in the partial regions 16,18 of the marking 14, the black intermediate layer 38 and the effect layer 40 is locally ablated by laser application and the security element 12 individually characterized.

<figref idrefs="f0002">Fig. 3 (a)</figref> shows a laser ablation of the layers 38, 40, it is through laser application but also possible to vaporize coating areas or convert it into a transparent or other color modification.

After the laser personalization of color impression when viewed perpendicularly 42 in the exposed portions 16, 18 respectively by the color impression of the sections 34, 36 of the ink layer 32 is determined so that the portion 16 of the color impression green (G) and the portion 18 of the color impression of magenta (M) results. In the surrounding region 20, the optically variable effect layer 40 showing against the background of the black intermediate layer 38 when viewed vertically the color impression magenta (M), so that when viewed vertically in the total<figref idrefs="f0001">Fig. 2 (a)</figref> gives visual impression shown.

<figref idrefs="f0002">Fig. 3 (b)</figref> illustrates the occurrence of the color impression when viewed obliquely 44. In the exposed portions 16, 18 of the color impression remains determined by the solid color impression of the sections 34, 36 of the ink layer 32 so that the portion 16 as viewed perpendicularly to the perceived color green (G) and the partial area 18 the color impression of magenta (M) shows. In the surrounding region 20, the optically variable effect layer created against the background of the black intermediate layer 38 when viewed obliquely the color impression green (G), so that when viewed obliquely total of in<figref idrefs="f0001">Fig. 2 (b)</figref> gives visual impression shown.

A particular advantage of the inventive security element is that the color layer 32, the intermediate layer 38 and the effect layer 40 on the one hand all. By printing processes and therefore can be produced easily and inexpensively and on the other hand enables the individualization by laser application subsequent individualization of the security element So the be displayed with the identification information should not be known at the time of manufacture, but can be produced only in the use of the security element.

The <figref idrefs="f0003">Figures 4-7</figref> show various advantageous modifications of the security element of the <figref idrefs="f0002">Fig. 3</figref>,

The security element 12 of the embodiment of <figref idrefs="f0003">Fig. 4</figref> corresponds substantially to the security element of the <figref idrefs="f0002">Fig. 3</figref>, But the black intermediate layer 38 is not removed in the marking portions 16,18 through the laser application, but merely been converted into a transparent modification 46th The effect layer 40 can be ablated in this variant by the laser radiation, as described in<figref idrefs="f0002">Fig. 3</figref> shown, or even continue to exist, as in <figref idrefs="f0003">Fig. 4</figref> shown. The latter is particularly appropriate when the color impressions of the color layer portions 34, 36 are relatively light, since the optically variable effect layer 40 then before the light background is hardly noticeable in the marking fields 16,18. It is also conceivable that the effect layer 40 is also in a modified form in the area above the marking sections 16,18.

<figref idrefs="f0003">Fig. 5</figref> shows a further embodiment of the invention in which the security element 12 comprises an opaque, optically variable effect of layer 48th Such opaque effect layers can be produced, for example, printing inks with multilayer interference coating pigments, such as those under the name OVI^® be sold by the company SICPA. The marking 14 is formed in this case by recesses 16,18 or, alternatively, by local, generated by the action of laser radiation transparent modifications of the effect layer 48th

In the further embodiment of the <figref idrefs="f0003">Fig. 6</figref> 50 is formed of a laser-sensitive color mixture from which the action of laser radiation, a color component can be removed, the ink layer. Such color mixtures can, for example, first colored pigments and laser-sensitive core-shell particles containing a second colored pigment, wherein the core-shell particles are provided with a functional layer ablationsfördernden. In non-laser-exposed area 20 then are both colored pigments before and together produce a dark background for a transparent, optically variable effect layer 40. In the laser-exposed area 16 the laser-sensitive core-shell particles with the second colored pigments are removed from the ink layer 50, so that the color impression is there governed only by the first colored pigment.

In the second laser-exposed area 18 may for example be another first colored pigment in the ink layer 50 and are generated by laser impingement another marking paint.

Alternatively, the color mixture of the color layer 50 contain a number of laser-sensitive core-shell particles with a second or third color pigment, which are removed by different ablationsfördernde functional layers with different amounts of laser intensity from the mixture. In non-laser-exposed area 20 then, all three color pigments before and for a dark background for the transparent, optically variable effect layer 40. In the laser-exposed area 16 only the laser-sensitive core-shell particles is at a low laser intensity, for example, flies with the third colored pigment so that the color impression is determined there by a superposition of the first and second colored pigments (first solid color impression). In laser-exposed area 18, the laser-sensitive core-shell particles is removed in addition to the second colored pigment so that the color impression is there governed only by the first colored pigment (second solid color impression) at high laser intensity. Here can be generated with a suitable choice of the color pigments the desired color impressions in the first and second section 16.18 of the marking.

Another variant of the invention is in <figref idrefs="f0003">Fig. 7</figref> shown. In this embodiment, the ink layer 52 is formed of a layer 54 of a non-laser-sensitive Fixfarbe and applied over layer 56, which also includes laser-sensitive core-shell particles with a second colored pigment next first colored pigments, wherein the core-shell particles with a ablationsfördernden functional layer are provided. In laser-exposed area 16 the laser-sensitive core-shell particles are removed with the second colored pigment so that the color impression is determined there by the first colored pigment (first solid color impression). In the laser-exposed area 18 of the entire layer is at high laser intensity 56 has been ablated, so that the color effect is given there by the underlying Fixfarb layer 54 (second solid color impression).

<figref idrefs="f0004">Fig. 8</figref> shows a security element 60 according to another embodiment of the invention, in which the marking 62 has a gradient with soft transitions in the form of the writing "50 euros". For example, the color impression of the marking 62 from top to bottom can slowly change from green to magenta. It should be emphasized that it is not in this gradient to a variable color impression as the color impression at any point of the course upon tilting the security element 60 remains unchanged. Rather, the fixed color impression even changed virtually continuously from the top to the bottom edge of the marking 62nd

In the embodiment of this quasi-continuous gradient is by using only two colors (green and magenta) generated by the gradual change in the area ratio of the colors in adjacent streaks. <figref idrefs="f0004">Fig. 9</figref> this is shown in a gradient 70 having a plurality of green color stripes 72 and magenta color stripes 74 which are arranged in a one-dimensional grid with grid spacing d. Within each grid width d of the surface portion takes g of green color strip 72 from the top down from 100% to 0% from. Accordingly, taking the area ratio m = 100% - g of the magenta color stripe 74 from top to bottom from 0% to 100% to. If the grid spacing d chosen small enough, it is clear to the eye a continuously appearing gradient 70 from green to magenta. In practice, usually just a few grid periods, for example, 6, 8 or 10 raster scanning periods to generate a soft gradient for the eye.

<figref idrefs="f0004">Fig. 10</figref> now shows a cross section through the security element 60 along the line XX of <figref idrefs="f0004">Fig. 8</figref>, As in<figref idrefs="f0004">Fig. 10</figref> shown, a color layer 82 is applied to the substrate 80 is printed in the field of marking 62 the gradient 70 of <figref idrefs="f0004">Fig. 9</figref> contains. The color impression varies from the first portion 84 to second portion 86 virtually continuously from the solid magenta color impression to the solid green color impression.

On the color layer 82, a laser-sensitive, black intermediate layer 38 and printed on the intermediate layer 38, a transparent optically variable effect layer 40, 38 having a color-shift effect of magenta when viewed vertically to green when viewed obliquely against the background of the black intermediate layer. After the preparation of the said sequence of layers by laser application were the black intermediate layer 38 and the effect layer 40 "50 Euro" ablated locally in the form of the writing and the security element 60 thus bears the marking 62nd

When viewed perpendicularly, the effect layer 40 appears in the surrounding area 20 of identification in the context of the black intermediate layer 38 with color impression Magenta and thus with the same color impression as the lower part 62-U labeling 62. From the marking 62 are therefore upon perpendicular viewing only the middle and to recognize upper part.

When tilting the security element 60 in the direction of arrow 64, the color impression of the effect layer 40 changes in the surrounding region 20 initially to a mixed color magenta / green, and thus the same color impression of the middle part 62-M of the marking indicates. For further tilting the color impression of the effect layer 40 then changes to green, so the same color impression of the upper portion 62-O shows the labeling.

When tilting in the direction of arrow 64 thus disappears first, the middle and then the upper part of the marking 62 due to the missing contrast of the surrounding region 20 to the viewer, while the lower, magenta part 62-U is visible. When rapid switching back and forth all the parts of the mark 62 can be recognized again due to the inertia of the human eye.

The in <figref idrefs="f0004">Figures 8 to 10</figref> shown and discussed above security element 60 can also be regarded as a security element comprising a plurality of subregions, each with solid color impression in a particular subregion, as required according to the invention.

<u>LIST OF REFERENCE NUMBERS</u>

<dl id="dl0002"><dt>10</dt><dd>bill</dd><dt>12</dt><dd>Security element</dd><dt>14</dt><dd>identification</dd><dt>15</dt><dd>Denomination</dd><dt>16.18</dt><dd>subregions</dd><dt>20</dt><dd>surrounding area</dd><dt>30</dt><dd>substratum</dd><dt>32</dt><dd>optically-variable ink layer</dd><dt>34.36</dt><dd>subregions</dd><dt>38</dt><dd>interlayer</dd><dt>40</dt><dd>transparent optically variable effect layer</dd><dt>42</dt><dd>vertical supervision</dd><dt>44</dt><dd>oblique viewing</dd><dt>46</dt><dd>transparent modification</dd><dt>48</dt><dd>opaque layer optically variable effect</dd><dt>50</dt><dd>coat of paint</dd><dt>52</dt><dd>coat of paint</dd><dt>54</dt><dd>not laser-sensitive Fixfarbe</dd><dt>56</dt><dd>layer</dd><dt>60</dt><dd>Security element</dd><dt>62</dt><dd>identification</dd><dt>62-O, 62-M, 62-U</dt><dd>marking parts</dd><dt>64</dt><dd>tilt direction</dd><dt>70</dt><dd>gradient</dd><dt>72</dt><dd>green streaks</dd><dt>74</dt><dd>magenta color stripes</dd><dt>80</dt><dd>substratum </dd><dt>82</dt><dd>coat of paint</dd><dt>84.86</dt><dd>subregions</dd></dl>