EP2448767B1 - Security element, and method for the production thereof - Google Patents

Description

The invention relates to a security element for security papers, Wertdoktunente or the like., With a top and a bottom having carrier which is at least partially transparent or translucent, mounted on the top, top embossing lacquer layer, in which an upper embossed structure is formed, a lower embossing lacquer layer mounted on the lower side, in which a lower embossed structure is formed, an upper reflective layer disposed on the upper embossing lacquer layer having an upper reflective layer structure, and a lower reflective layer disposed on the lower embossing lacquer layer and having a lower reflective layer structure.

The invention relates to a manufacturing method for a security element for security papers, documents of value or the like, in which a top and a bottom having carrier on the top with an upper embossing lacquer layer and thereon with an upper reflective layer, and at the bottom with a lower embossing lacquer layer and provided thereon with a lower reflection layer, wherein an upper embossing pattern is formed in the upper embossing lacquer layer and a lower embossing pattern is formed in the lower embossing lacquer layer, and the upper reflection layer has an upper reflection layer structure and the lower reflection layer has a lower reflection layer structure.

Items to be protected are often provided with a security element that allows verification of the authenticity of the item and at the same time serves as protection against unauthorized reproduction.

Items to be protected include, for example, security papers, identity and value documents (such as banknotes, chip cards, passports, identification cards, identity cards, stocks, bonds, certificates, vouchers, checks, tickets, credit cards, identity cards, etc.) as well as product security elements such as security items. Labels, seals, packaging.

The security against forgery of a security element is particularly great when the security element on the front and back shows perceptible motifs that are in a certain position to each other and / or difficult to imitate or copy.

The generic WO 03/053713 A1 describes a security element which is constructed on a plastic film and carries on both sides of the plastic films relief structures that act as diffraction structures and, for example, as a hologram represent a motif. The relief structures are further provided with metal layers which are structured by interruptions, so that additionally a suitable pattern, for example a letter or another alphanumeric character, can be recognized. The structured metallization on the relief structures is designed as a reflection layer, so that the corresponding motif is visible in plan view.

• einem eine Oberseite und eine Unterseite aufweisenden Träger (3), der zumindest teilweise transparent oder transluzent ist,
• einer oberen Prägestruktur (15), die in dem Träger ausgebildet ist,
• einer unteren Prägestruktur (10), die in dem Träger ausgebildet ist, und
• einer auf der unteren Prägelackschicht angeordneten unteren Reflexionsschicht (10, implizit, dass diese Struktur eine Reflexionsschicht aufweist (siehe S. 13 Z. 5-6)), die eine untere Reflexionsschichtstruktur hat, wobei
• die untere Reflexionsschichtstruktur zusammen mit der oberen Prägestruktur in Durchlichtbetrachtung als Durchlichtmotiv sichtbar ist und
• die untere Reflexionsschichtstruktur und die obere Prägestruktur jeweils durch ein moduliertes Linienraster erzeugt ist, wobei die Linienrichtung der oberen Prägestruktur kreuzend zur Linienrichtung der unteren Reflexionsschichtstruktur liegt (S. 13 Z. 6-11).

The document WO 97/19820 A1 (closest prior art) discloses (see in particular Fig. 11) a security element for security papers, documents of value or the like., With

• a carrier (3) having an upper side and a lower side which is at least partially transparent or translucent,
• an upper embossing structure (15) formed in the carrier,
• a lower embossing structure (10) formed in the carrier, and
• a lower reflection layer (10) implicitly disposed on the lower embossing lacquer layer (implicitly having a reflection layer (see page 13, lines 5-6)) having a lower reflection layer structure, wherein
• the lower reflection layer structure is visible together with the upper embossed structure in transmitted light observation as transmitted light motif and
• the lower reflective layer structure and the upper embossing structure are each produced by a modulated line grid, wherein the line direction of the upper embossing structure is crossing to the line direction of the lower reflection layer structure (page 13 Z. 6-11).

This document does not disclose an upper reflective layer disposed on the upper embossing lacquer structure nor does it disclose that the security element comprises two embossing lacquer layers.

This document discloses security elements having a support between two embossed patterns (e.g., Fig. 9) each provided with a reflective layer structure, but the line directions of the line patterns of these reflective layer structures are not crossing each other.

The document AU 734 937 B2 discloses a security element with see-through structures with two line grids whose line directions are crossing each other, but without embossing structures (see in particular p. 10 fourth paragraph, p. 15 fourth paragraph first sentence, p. 20 Z. 23-25).

The document AU 2003 266 829 B2 discloses a security element with see-through structures with two line grids whose line directions are crossing each other, but only with at most a single reflection layer (Fig. 17-19, see also page 8 Z. 16-20, p. 10 Z. 20-23, p 23 Z. 7-S. 24 Z. 2, S. 2 first paragraph).

The invention has the object of providing a security element to sheep fen, which shows different motifs on the front and back and in transmitted light viewing another motif in good quality.

This object is achieved by a security element for security papers, documents of value or the like, with a top and a bottom having carrier, which is at least partially transparent or translucent is an upper embossing lacquer layer mounted on the upper side in which an upper embossing pattern is formed, a lower embossing lacquer layer attached on the lower side in which a lower embossing pattern is formed, an upper reflecting layer disposed on the upper embossing lacquer layer, having an upper reflection layer structure and a lower reflective layer disposed on the lower embossing lacquer layer and having a lower reflective layer structure, the lower reflective layer structure together with the upper reflective layer structure having transmitted light as a visible reflection pattern, and the lower reflective layer structure and the upper reflective layer structure each having a modulated line pattern the line direction of the upper reflection layer structure is crossing with the line direction of the lower reflection layer structure.

The object is further solved by a value document with such a security element.

Finally, the object is also achieved by a production method for a security element for security papers, documents of value or the like, in which a top and a bottom having carrier at the top with an upper embossing lacquer layer and then with an upper reflective layer, and at the bottom with a lower embossing lacquer layer and provided thereon with a lower reflection layer, wherein an upper embossing pattern is formed in the upper embossing lacquer layer and a lower embossing pattern is formed in the lower embossing lacquer layer, the upper reflection layer has an upper reflection layer structure, and the lower reflection layer has a lower reflection layer structure, and wherein the lower reflection layer structure is composed with the upper reflection layer structure in transmitted light, cause a transmitted light pattern, and the lower reflection layer structure and the upper reflection layer structure each having a modulated line grid, wherein the line direction of the upper reflection layer structure is crossing with the line direction of the lower reflection layer structure.

The angle between the line directions should be as vertical as possible to avoid unwanted moiré effects. However, an angle of 60 ° to 120 °, preferably 70 ° to 110 °, more preferably from 80 ° to 100 ° is sufficient.

The invention provides a surprisingly simple constructed security element, which has both a recognizable from the front side front motif, which is not visible from the back, and has a visible from the back back motif, which is imperceptible from the front. In addition, through the structures of the reflection layers, a transmission light visible in transmitted light observation is present as a further security feature.

The reflection layer structures are realized by modulated line rasters, preferably with a line width between 20 μm and 200 μm, particularly preferably between 50 μm and 150 μm. The alignment of the line structures at the top and bottom avoid disturbing moiré effects or locally different transmission properties surprisingly simply in that the two line patterns intersect each other. The crossed line grids do not disturb each other and provide a particularly good and clearly recognizable motif in the transparent picture.

The combination motif is generated jointly by the upper and lower reflective layer structures. Due to the crossed line grid need the reflective layer structures on the top and bottom are not costly matched. The creation is thus much easier than with structures that have to have a certain level to each other.

By using a line width raster with crossed line directions, the top and bottom reflection structures are superimposed without affecting each other. It is therefore easily possible to provide an independent motif for each of the two reflection layer structures. Each of the motifs realized thereby, that is to say the upper motif which generates the upper reflection layer structure, and the lower motif, which is effected by the lower reflection layer structure, are clearly recognizable in the see-through image in the superposition of the crossed line patterns.

For the reflection layer with the reflection structures, a color layer can be provided. This is particularly simple if the respective reflection layer is produced by means of an etching process. In this case, usually before the etching process, a protective lacquer is printed, which covers the reflection layer (for example, a metallization) at those locations where no opening or interruption is to be incorporated, and protects against the etchant, for example, an etchant. This protective lacquer usually remains on the structured reflection layer, i. H. those portions of the reflective layer that were not removed by the etching process. If this protective varnish is colored, then it can be achieved that the motif generated by the respective reflection layer also has a color effect, eg. B. is colored. At the same time, this color effect does not occur in transmitted light or when viewed from the other side.

In the case of the upper and lower reflection layers, it is particularly advantageous to provide different colors for the respective reflection layer. The corresponding motifs then have different color effects, whereas the transmitted light motif, which is generated by the interaction of the two reflection layers (or a reflection layer), does not substantially show these color effects.

In a simple construction of the security element, the motifs generated by the reflective layer structures are independent and do not have to be matched to one another, as long as they are not interfering with each other in the transparency. In a preferred development of the security feature, the combination of the upper and lower motif results in a combination motif that is composed of the upper motif and the lower motif.

The raster elements of the upper and lower reflective layers can advantageously also be designed so that the resulting transmitted light motif is dependent on the viewing angle. In a first variant, this can be achieved in that the screening of the upper and the lower reflection layer have different screen widths. Then moiré-magnified images emerge in the transmitted light, the appearance of which depends on the viewing angle. In a second variant, a known shading grid can be used, for example by a raster structure containing no motif. At certain viewing angles, this raster structure then shades the raster structure of the other reflection layer in which the motif is modulated.

The desired see-through effect can in principle be achieved by any screening which on the one hand is so small in terms of fineness that the grid elements are not noticeable to the eye and, on the other hand, locally modulated in their average area coverage such that the viewing motif (s) is / is visible. In this case, either the density of the raster elements and / or the size of the raster elements can be modulated. The fineness of the screening at the same time ensures that the upper or lower reflection layer continues to fulfill its function in connection with the corresponding embossing structure or does not disturb it.

Depending on the embodiment of the embossing lacquer layers and the motifs produced thereby, the respective reflection layer structure can be discernible in plan view, if appropriate in an oblique top view, in the reflection layer located on the embossing lacquer layer. If the upper reflection layer structure and the lower reflection layer structure are formed in such a way that they produce a combination motif, the corresponding part of the combination motif is seen from the front side, on which the upper reflection layer structure is located, and from the bottom, the part effected by the lower reflection layer structure.

The embossing of the upper embossed structure or the lower embossed structure is preferably carried out with commercially available embossing lacquers, as used for example as heat sealing lacquers in the DE 102004035979 A1 are described. In principle, thermoplastic, electron beam-curing or UV-curing embossing lacquer systems are suitable.

Since at least one embossing lacquer layer has to be anchored directly on the support, which can be embodied, for example, as a film, a good adhesion of the embossing lacquer layer usually between 1 μm and 10 μm, preferably between 1.5 μm and 4 μm, is desirable. This can be achieved by the use of carrier materials, eg. As film material can be achieved with suitable pretreatment. Examples include an acrylate coating in combination with a corona treatment before the application of the embossing lacquer or the printing of adhesion-promoting primers. Due to the then good adhesion of the embossing lacquer to the carrier, a pure casting process can be used for embossing, in which the embossing lacquer is pressed into an embossing cylinder without further pretreatment. In this way, one obtains an optimal reproduction of an embossed structure, resulting from a very good image of the embossing tool. Brilliant embossed motifs are the result.

It is therefore preferred in a development that the top and / or the bottom is provided with a Prägelackhaftung improving treatment / are. It is also preferred if the upper and / or the lower embossing lacquer layer has a UV-curing embossing lacquer. Such UV embossing lacquers have the further advantage that they are particularly well suited as an acceptance layer for offset and steel stitch paints. They can thus serve as background for banknote printing coverage with offset or steel stitch colors. A naturally otherwise possible at any time pressure receiving layer on one side of the security element can then be omitted.

The protection by the security element is particularly high by the third recognizable in transmitted light motif. For this purpose, the upper and the lower reflection layer are not over the entire surface, but provided with motif-dependent interruptions or openings to form the line-scored top or bottom motif. In the case of a metallic reflection layer, this structuring can be carried out, for example, by demetallization using technologies known to the person skilled in the art (etching technology and washing process). In the case of a printed reflective layer, the required printing ink is printed in the form of a fine motif.

The security element can be designed, in particular, as a security thread, tear-open edges, security strip, security strip, patch or label for application to a security paper, value document or the like. In particular, the security element can span transparent areas or recesses.

The term security paper is understood here in particular as the precursor that can not be processed to a value document which, in addition to the security element according to the invention, may also have further authenticity features (such as, for example, luminescent substances provided in the volume). Value documents are here understood, on the one hand, documents produced from security papers. On the other hand, value documents can also be other documents and objects which can be provided with the security feature according to the invention, so that the value documents have non-copyable authenticity features, whereby an authenticity check is possible and at the same time unwanted copies are prevented.

In this description, translucency or translucent is understood as meaning the partial translucency of a body, ie the property of transmitting light without being transparent. Translucence is thus to be seen in contrast to transparency (= transparency of image or sight). The reciprocal property of translucency is opacity. For the purpose of this description, a body is translucent or transparent if the transmittance in the region of the visible optical radiation (= light) is at least 90%. At transmittances between 10 and 90%, the body is partially transparent or translucent.

The production method according to the invention can be developed so that the described preferred embodiments and embodiments of the security element are produced.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the specified combinations, but also in other combinations, without departing from the scope of the present invention, insofar as this is covered by the scope of the claims.

Fig.1

eine Draufsicht einer Banknote mit einem Sicherheitselement 1,

Fig. 2

einen vergrößerten Abschnitt eines Teils des Schnittes entlang der Linie A-A der Fig.1,

Fig. 3

eine Schemadarstellung eines liniengerasterten Motivs in einer oberen Reflexionsschicht des Sicherheitselementes,

Fig. 4

ein Linienraster für eine untere Reflexionsschicht des Sicherheitselementes und

Fig. 5-8

unterschiedliche Überlagerungen der Linienraster der Fig. 3 und 4.

The invention will be explained in more detail by way of example with reference to the accompanying drawings, which also disclose features essential to the invention. Show it:

Fig.1

a top view of a banknote with a security element 1,

Fig. 2

an enlarged portion of a part of the section along the line AA of Fig.1 .

Fig. 3

a schematic representation of a line-scanned motif in an upper reflective layer of the security element,

Fig. 4

a line grid for a lower reflective layer of the security element and

Fig. 5-8

different overlays of the line grid of 3 and 4 ,

The figures are not shown to scale for ease of illustration. Furthermore, some hatching is not shown in order to represent the structure of the corresponding security element 1 more clearly.

Incidentally, elements which in different embodiments functionally and / or structurally equal or correspond bear the same reference sign in all figures in order to avoid description repetition. In the following description of sectional views is referred to as the front of the security element in the representations above page. The back is accordingly the bottom side. This convention is merely for ease of description and is not intended to be limiting as to the construction and / or application of the security element.

At the in Fig. 1 In the embodiment shown, a security element 1 is integrated in a banknote 2 in such a way that the security element 1 is located both from the in Fig. 1 shown front side of the banknote 2 and from the back of the banknote 2 is visible.

The security element 1 provided on the banknote 2 can also be part of a security thread 19 of the banknote which, as in FIG Fig. 1 illustrated by way of example, is usually woven into the paper of the banknote 2 in such a way that it is partly on the front (the in Fig. 1 visible side) and partly visible on the back of the banknote. It is also possible to arrange the security element 1 at least partially over a window 20 provided in the banknote 2. Of course, these possibilities are only examples of the use of the security element 1 described below, which of course can also be used in other ways for copying or imitation protection of a protected object.

Fig. 2 shows a sectional view through the security element 1 along the line AA of Fig. 1 , Basis for the security element 1 is a carrier 3, which can be realized for example by a plastic film. This plastic film is transparent or even transliterated, as will be explained later.

At the front of the security element 1 is for the following description, the top 4 of the carrier 3, at the back of the security element 1, the bottom 5 of the carrier. On the upper side 4 and lower side 5 suitable adhesion promoters 6 and 7 are attached to the carrier 3, which ensure that the following layers have a strong adhesion to the carrier 3. The bonding agent 6 or 7 can on the one hand by a suitable pre treatment of the carrier or use of films suitable coating such. As acrylate coating in combination with corona treatment, or by printing of adhesion promoting primer can be achieved.

An embossing lacquer layer 9 or an embossing lacquer layer 10 is then applied to the sides 4, 5 of the carrier 3 provided with adhesion promoters 6 and 7, respectively. The embossing lacquer layers 9, 10 thus obtained are now provided with an upper embossing structure 11 or a lower embossing structure 12. Due to the good adhesion of the embossing lacquer layers 9, 10 on the upper side 4 or lower side 5 of the carrier 3, the embossing lacquer structures 11 and 12 can be pressed without further pretreatments with an embossing cylinder.

Reflection layers 8, 14 are then applied to the embossing lacquer layers 9, 10. These are preferably reflective layers, which are for example by a metallization (for example, aluminum, copper, iron, chromium, gold, silver, etc. with optical densities between 1.3 oD to 4.5 oD, preferably between 1.8 oD to 3.0 oD) can be realized. Alternatively, printed glossy lacquer coatings are also possible. Also, different reflection layers can be combined in order, as will be explained, to produce desired visual appearances of the subjects presented by the security element 1 to the observer.

The embossing structures realize, in connection with the reflective reflection layers 8, 14, a top embossing motif and a bottom embossing motif, respectively, which is visible when viewed from the front side VS or when viewed from the rear side RS. Of course, different motifs of the front side VS and the rear side RS can be used. If one of the two sides of the security element 1 is to be printed, this can be done directly on the embossing lacquer 9 or 10 if a UV embossing lacquer is used for this purpose. This is suitable as an acceptance layer for offset and steel engraving inks. Print acceptance layers, which would require several operations for the application, are therefore no longer necessary.

The reflection layer 8 is provided with an upper reflection layer structure which effects a motif. Ie. the reflection layer 8 is not over the entire surface on the upper side 4 of the carrier 3, but has a motif-forming varying opacity, ie a pattern. This is line rasterized. The same applies to the reflection layer 14. The raster density of the raster structure or structuring of the reflection layers is selected so that the structure and the motive caused by it is not noticeable or very little when viewed from the front VS and the back RS. In the case of metallic reflection layers 8, 14, these patterns can be achieved, for example, by demetallization using known technologies (etching technology and washing method). If printed reflection layers are used, the respective motif is already produced during printing by application of the printing ink.

In transmitted light, the two reflection structures of the upper reflection layer 8 and the lower reflection layer 14 cooperate. In plan view, in particular in oblique top view, however, one not only sees the embossed motifs produced by the embossing structures 11 and 12, but may additionally also recognize the structure and thus the motif in the upper or lower reflection layer 8, 14. Thus, security element 1 provides a total of five different motifs. In addition to those already using the Fig. 3 As safety features, the motifs of the upper reflection layer 8 and of the lower reflection layer 14, which can be seen in plan view, in particular in an oblique top view, are explained.

The security element 1 of Fig. 3 Thus, it has an upper embossing structure 11, which provides an embossed motif, which is visible from the direction of the front side VS forth. From the back RS fro another embossed motif can be seen, which causes the lower embossing structure 12.

On the other hand, if the security element 1 is viewed in transmitted light, for example under illumination from the rear side RS and in viewing from the front side VS, one recognizes the structures and thus the motifs in the reflection layers 8, 14. Thus, as the third security feature, the apparent appearing in reflection motif of the reflection layers is formed. In this case, the structures of the upper reflection layer 8 and the lower reflection layer 14 cooperate when the security element 1 is viewed in transmitted light. For the motif incorporated in the upper reflection layer 8 or the lower reflection layer 14, a line width rastering can be used, preferably with a line width between 20 μm and 200 μm, particularly preferably between 50 μm and 150 μm.

Fig. 3 schematically shows the upper reflection layer structure 15 in the upper reflection layer 8 of Fig. 2 , and Fig. 4 FIG. 12 shows the lower reflection layer structure 18 in the lower reflection layer 14 of FIG Fig. 2 , As an example, for the upper reflection structure 15 in Fig. 3 two more top motives 16 and 17 are shown, which are visually recognizable when viewing the security element 1 from the front side VS in addition to the embossing motif which is introduced into the embossing lacquer layer 9 by the upper embossing structure 11. For ease of illustration, no motif is drawn for the lower reflection layer structure 18. Of course, one will usually provide a motif similar to the upper motif 16 or 17 also in the lower reflective layer structure 18.

If the line directions of the upper reflection layer structure 15 and of the lower reflection layer structure 18 were arranged completely parallel, then the result would be, as in FIG Fig. 5 shows, depending on the Passerting a more or less large disturbance of the perceptibility of the upper motifs 16 and 17.

Are the line grid still slightly tilted to each other, which can easily happen in practice, it is similar to inadequate Passerung in Fig. 5 also a strong disturbance of the perceptibility of the motifs, since a corresponding moiré effect occurs. this shows Fig. 6 ,

In order to avoid such disturbances of perceptibility, it is therefore ensured that the line grids of the upper reflection layer structure 15 and the lower reflection layer structure 18 are as perpendicular as possible to one another. As Fig. 7 shows there is then virtually no disturbance of the motives. This is true as well Fig. 8 shows if the perpendicularity of the line is not maintained, but there is a deviation from the orthogonal position.

In practice, it has been found that at an angle range between 60 ° and 120 ° (i.e., 90 ° +/- 30 °), preferably between 70 ° and 110 °, and most preferably between 80 ° and 100 °, d. H. 90 ° +/- 10 °, an almost imperceptible, in any case tolerable disturbance of the motives, which are incorporated in the upper reflective layer structure 15 and / or the lower reflective layer structure 18 by Linienbreitenrasterung. The more perpendicular the line grids are, the lower is a possible disturbance. Depending on the effort that is possible in the production, the above-mentioned deviation from the squareness can be tolerated.

The carrier 3 can be made transparent. Then the image appearing in transmitted light is particularly clear. If one uses only a translucent carrier 3, the separation of the image formed by the front side VS by the embossing structure 11 from the image produced at the rear side RS by the lower embossing structure 12 increases at the expense of the quality of the transmitted light image.

If one wishes to have a smooth surface on at least one side of the security element 1, it is expedient to attach a covering layer 21 on this corresponding side. This is in Fig. 2 entered dashed. Such cover layers are known in the art, for example from the already cited WO 03/053713 A1 ,

Claims (9)

1. A security element for security papers, value documents with

   - a carrier (3), which is at least partially transparent or translucent and has an upper face (4) and a lower face (5),

   - an upper embossing lacquer layer (9) which is applied to the upper face (4) and in which an upper embossed structure is formed,

   - a lower embossing lacquer layer (10) which is applied to the lower face (5) and in which a lower embossed structure is formed,

   - an upper reflective layer (8), which is arranged on the upper embossing lacquer layer (9) and has an upper reflective layer structure (15), and

   - a lower reflective layer (14), which is arranged on the lower embossing lacquer layer (10) and has a lower reflective layer structure (18),
   wherein

   - the lower reflective layer structure (18) and the upper reflective layer structure (15) together are visible when viewed with transmitted light as a transparency motif and

   - the lower reflective layer structure (18) and the upper reflective layer structure (15) are each generated by a line half-tone, wherein a line direction of the upper reflective layer structure (15) lies across a line direction of the lower reflective layer structure (18), preferably at an angle of from 60 to 120 degrees.
2. The security element according to claim 1, in which the upper reflective layer structure (15) and the lower reflective layer structure (18) each form a motif, wherein the two motifs jointly form a combined motif when viewed with transmitted light.
3. The security element according to claim 1 or 2, in which at least one of the upper face (4) and the lower face (5) is provided with a treatment improving the embossing lacquer adhesion.
4. The security element according to one of the above claims, in which at least one of the upper and lower embossed lacquer layer comprises a UV-curing embossing lacquer.
5. The security element according to one of the above claims, in which the carrier (3) is provided with a matting coating.
6. A value document with a security element according to one of claims 1 to 5.
7. A method for manufacture of a security element for security papers, value documents in which

   - a carrier (3) having an upper face (4) and a lower face (7) is provided with an upper embossing lacquer layer (9) on the upper face (4) and, on top of that, with an upper reflective layer (8), and with a lower embossing lacquer layer (10) on the lower face (4) and, on top of that, with a lower reflective layer (14), wherein

   - an upper embossed structure (11) is introduced into the upper embossing lacquer layer (9) and a lower embossed structure (12) into the lower embossing lacquer layer (10),

   - the upper reflective layer (8) is provided with an upper reflective layer structure (15) and the lower reflective layer (14) is provided with a lower reflective layer structure (18),
   wherein

   - the lower reflective layer structure (15) and the upper reflective layer structure (18) together are visible under transmitted light as transparency information and

   - the lower reflective layer structure (18) and the upper reflective layer structure (15) are each generated by a line half-tone, wherein a line direction of the upper reflective layer structure (15) lies across a line direction of the lower reflective layer structure (18), preferably at an angle of from 60 to 120 degrees.
8. The method according to claim 7, in which at least one of the upper face (4) and the lower face (5) is provided with a treatment improving the embossing lacquer adhesion.
9. The method according to claim 7 or 8, in which a UV-curing embossing lacquer is used for at least one of the upper and lower embossing lacquer layer (9, 10).

Images