EP2448767A1

EP2448767A1 - Security element, and method for the production thereof

Info

Publication number: EP2448767A1
Application number: EP10730428A
Authority: EP
Inventors: Manfred Heim; Lars Hoffmann
Original assignee: Giesecke and Devrient GmbH
Current assignee: Giesecke and Devrient GmbH
Priority date: 2009-07-01
Filing date: 2010-06-30
Publication date: 2012-05-09
Anticipated expiration: 2030-06-30
Also published as: WO2011000878A1; DE102009031387A1; AU2010268081B2; MX2012000033A; EP2448767B1; AU2010268081A1

Abstract

The invention relates to a security element for security papers, value documents and the like, comprising the following: a carrier (3) having an upper face (4) and a lower face (5), said carrier being at least partly transparent or translucent; an upper embossed lacquer layer (9), which is applied to the upper face (4) and in which an upper embossed structure is formed, and a lower embossed 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 lies on the upper embossed lacquer layer (9) and which has an upper reflective layer structure (15); and a lower reflective layer (14) which lies on the lower embossed lacquer layer (10) and which has a lower reflective layer structure (18). When the lower reflective layer structure (18) is viewed together with the upper reflective layer structure (15) under transmitted light, said layer structures are visible as a transmitted light motif. The lower reflective layer structure (18) and the upper reflective layer structure (15) are each produced by a modulated line raster, wherein the direction of the lines of the upper reflective layer structure (15) intersects the direction of the lines of the lower reflective layer structure (18), preferably at an angle of 60 to 120 degrees.

Description

Security element and

Manufacturing process for it

The invention relates to a security element for security papers, documents of value or the like, having 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 embossing structure is formed, a on the underside, a lower embossing lacquer layer in which a lower embossing pattern 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, health cards, etc.) as well as product security elements such as eg labels, seals, packaging.

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

The generic document WO 03/053713 A1 describes a security element which is constructed on a plastic film and carries relief structures on both sides of the plastic, which act as diffraction structures and, for example, represent a motif as a hologram. 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.

The object of the invention is to provide a security element which displays different motifs on the front and rear sides and a further motif of good quality when viewed through the light.

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 A top embossing lacquer layer mounted on the upper side, in which an upper embossing structure is formed, has a lower embossing lacquer layer attached to the lower side, in which a lower embossing layer is formed, an upper reflective layer, which is disposed on the upper embossing lacquer layer an upper reflective layer structure, and a lower reflective layer disposed on the lower embossing lacquer layer having a lower reflective layer structure, the lower reflective layer structure together with the upper reflective layer structure effecting a visible transmitted light pattern when viewed through transmitted light, and the lower reflective layer structure and the upper reflective layer structure each having a modulated line grid, wherein the line direction of the upper reflection layer structure is crossing to the line direction of the lower reflection layer structure. The object is further achieved 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 effect a transmission light motif with the upper reflection layer structure in transmitted light observation, and the lower reflection layer xionsschichtstruktur and the upper reflection layer structure each having a modulated line grid, wherein the line direction of the upper reflection layer structure is crossing to 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 sen the reflective layer structures on top and bottom are not lavishly adapted. The production is thus much easier than in structures that need 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 superimposition 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 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 overlapping of the upper and lower motif results

Combination motif composed of the top motive and the bottom motive.

The raster elements of the upper and lower reflection layers can advantageously also be designed in such a way 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 moire-magnified images are produced in 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, are spatially modulated in their average area coverage in such a way that the throughput visible / visible. In this case, either the density of the raster elements and / or the size of the raster elements can be modulated. At the same time, the fineness of the screening ensures that the upper or lower reflection layer continues to fulfill its function in connection with the corresponding embossed 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, one sees from the front side, on which the upper reflection layer structure is located, the corresponding part of the combination motif, and from the bottom side through the lower reflection layer structure Part.

The embossing of the upper embossing structure or of the lower embossing structure is preferably carried out using commercially available embossing lacquers, as described, for example, as heat seal lacquers in DE 102004035979 A1, the disclosure of which is fully incorporated by reference. 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 tion 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 the base 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 provided over the entire surface, but are provided with motif-dependent interruptions or openings in order to form the line-scanned upper or lower 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 may in particular be designed as a security thread, tear-open thread, security strip, security strip, patch or as a 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 yet be processed to form 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 unwanted copies are prevented at the same time. 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 or alone, without departing from the scope of the present invention. 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:

1 is a plan view of a banknote with a security element 1,

Fig. 2 is an enlarged portion of a portion of the section along the

Line A-A of FIG. 1,

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

4 shows a line grid for a lower reflection layer of the security element, and FIGS. 5-8 show different superimpositions of the line screens of FIGS. 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 resemble or correspond to the same reference numerals in all figures in order to avoid repeated descriptions. 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.

In the embodiment shown in FIG. 1, a security element 1 is integrated into a banknote 2 such that the security element 1 is visible both from the front side of the banknote 2 shown in FIG. 1 and from the backside of the banknote 2.

The security element 1 provided on the banknote 2 can also be part of a security thread 19 of the banknote, which, as shown by way of example in FIG. 1, is usually woven into the paper of the banknote 2 in such a way that it is partly placed on the front side (shown 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.

2 shows a sectional view through the security element 1 along the line AA of FIG. 1. The 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 translucent, 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, respectively, are applied to the carrier 3, which ensure that the following layers have a strong adhesion to the carrier 3. The adhesion promoter 6 or 7 can on the one hand by a suitable pretreatment of the carrier or use of films suitable coating tion, such. As acrylate coating in combination with corona treatment, or by printing of adhesion-promoting primers 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 and underside 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 can be obtained, for example, by metallization (for example aluminum, copper, iron, chromium, gold, silver, etc. having optical densities between 1.3 oD and 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. as will be explained, to produce desired visual appearances of the subjects presented by the security element 1 to the observer. In connection with the reflective reflection layers 8, 14, the embossing structures realize a top embossing motif or a bottom embossment motif that is visible when viewing from the front side VS or when viewing 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 with 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 an oblique plan view, one not only sees the embossed motifs produced by the embossing structures 11 and 12, but can optionally also

In addition, the structure and thus the subject in the upper or lower reflection layer 8, 14 recognize. Thus, security element 1 provides a total of five different motifs. In addition to those already explained with reference to FIG. 3, as security 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 still visible.

The security element 1 of FIG. 3 thus 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.

If, however, 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, the third security feature is the one in FIG

Seeing appearing motive of the reflection layers 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 shows the lower reflection layer structure 18 in the lower reflection layer 14 of Fig. 2. As an example, for the upper reflection structure 15 in Fig. 3 still two upper motifs 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.

Assigned now the line directions of the upper reflective layer structure 15 and the lower reflective layer structure 18 completely parallel, it would be, as shown in FIG. 5, depending on the Passerung a more or less large disturbance of the perceptible speed of the upper motifs 16 and 17th

If the line grids are still slightly tilted with respect to one another, which can easily happen in practice, a strong disturbance of the perceptibility of the motifs results similarly to insufficient fitting in FIG. 5, since a corresponding moire effect occurs. This is shown in 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 shown in FIG. 7, there are virtually no disturbances of the motifs. This also applies, as 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 shown that at an angle range between 60 ° and 120 ° (ie 90 ° +/- 30 °), preferably between 70 ° and 110 ° and most preferably between 80 ° and 100 °, ie 90 ° + / -10 °, an almost imperceptible, in any case tolerable, disturbance of the motives incorporated in the upper reflective layer structure 15 and / or the lower reflective layer structure 18 by line width scoring. 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 picture appearing in a transparent view 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 shown in dashed lines in Fig. 2. Such cover layers are known to the person skilled in the art, for example from the already cited WO 03/053713 A1.

Claims

Patent claims

1. Security element for security papers, value documents or the like, with

- One having a top (4) and a bottom (5) carrier

(3) which is at least partially transparent or translucent, an upper embossing lacquer layer (9), which is provided on the upper side (4) and in which an upper embossing structure is formed,

a lower embossing lacquer layer (10), which is provided on the underside (5) and in which a lower embossing structure is formed,

an upper reflective layer (8) disposed on the upper embossing lacquer layer (9) having an upper reflective layer structure (15) and a lower reflective layer (14) disposed on the lower embossing lacquer layer (10) having a lower reflective layer structure (18) therethrough marked that

the lower reflection layer structure (18) together with the upper reflection layer structure (15) is visible in a transmitted light view as a transmitted light motif, and

the lower reflection layer structure (18) and the upper reflection layer structure (15) are each formed by a modulated line grid, the line direction of the upper reflection layer structure (15) crossing the line direction of the lower reflection layer structure (18), preferably at an angle of 60 to 120 degrees.

2. Security element according to claim 1, wherein the upper reflection layer structure (15) and the lower reflection layer structure (18) each form a motif, wherein the two motifs in transmitted light view combine to form the combination motif.

3. Security element according to claim 1 or 2, wherein the upper side (4) and / or the underside (5) is provided with a Prägelackhaftung improving treatment / are.

4. Security element according to one of the above claims, wherein the upper and / or lower embossing lacquer layer has a UV-curing embossing lacquer.

5. Security element according to one of the above claims, wherein the carrier (3) is provided with a matting coating.

6. document of value with a security element according to one of claims 1 to 5.

7. A manufacturing method for a security element for security papers, documents of value or the like, in which

a support (3) having an upper side (4) and a lower side (7) on the upper side (4) with an upper embossing lacquer layer (9) and thereupon with an upper reflection layer (8), and at the lower side (4) with a lower one Embossing lacquer layer (10) and is provided thereon with a lower reflective layer (14), wherein

in the upper embossing lacquer layer (9) an upper embossing structure (11) and in the lower embossing lacquer layer (10) a lower embossing structure (12) are introduced,

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

characterized in that the lower reflection layer structure (15) together with the upper reflection layer structure (18) in transmitted light view is visible as see-through information and

the lower reflection layer structure (18) and the upper reflection layer structure (15) are each produced by a modulated line grid, the line direction of the upper reflection layer structure (15) crossing to the line direction of the lower reflection layer structure (18), preferably at an angle of 60 to 120 degrees.

8. A manufacturing method according to claim 7, wherein the top (4) and / or the bottom (5) is provided with a Prägelackhaftung-improving treatment.

9. Production method according to one of the above method claims, wherein for the upper and / or lower embossing lacquer layer (9, 10) a UV-curing embossing lacquer is used.