AU2010268081A1

AU2010268081A1 - Security element, and method for the production thereof

Info

Publication number: AU2010268081A1
Application number: AU2010268081A
Authority: AU
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: 2012-01-19
Anticipated expiration: 2030-06-30
Also published as: EP2448767A1; EP2448767B1; DE102009031387A1; MX2012000033A; AU2010268081B2; WO2011000878A1

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

WO 2011/000878 PCT/EP2010/059302 Security element, and method for the prod uction thereof 5 The invention relates to a security element for security papers, value documents or the like, with a carrier, which is at least partially transparent or translucent and has an upper face and a lower face; an upper embossing lacquer layer, which is applied to the upper face and in which an upper embossed structure is formed; a lower embossing lacquer layer, which is 10 applied to the lower face and in which a lower embossed structure is formed; an upper reflective layer, which is arranged on the upper embossing lacquer layer and has an upper reflective layer structure; and a lower reflective layer, which is arranged on the lower embossing lacquer layer and has a lower reflective layer structure. 15 The invention relates to a method for the manufacture of a security element for security papers, value documents or the like, in which a carrier having an upper face and a lower face is provided with an upper embossing lacquer layer on the upper face and, on top of that, with an upper reflective layer, 20 and with a lower embossing lacquer layer on the lower face and, on top of that, with a lower reflective layer, wherein an upper embossed structure is formed in the upper embossing lacquer layer and a lower embossed structure in the lower embossing lacquer layer, and the upper reflective layer has an upper reflective layer structure and the lower reflective layer a lower 25 reflective layer structure. Articles to be protected are often provided with a security element which allows the authenticity of the article to be checked and at the same time serves as protection against unauthorized reproduction. 30 WO 2011/000878 PCT/EP2010/059302 -2 Articles to be protected are for example security papers, identity and value documents (such as e.g. banknotes, smart cards, passports, identity cards, identification cards, shares, bonds, certificates, coupons, cheques, admission tickets, credit cards, health insurance cards, etc.) as well as product security 5 elements, such as e.g. labels, seals, packaging. The level of protection against forgery of a security element is particularly great when the security element displays motifs discernible on the front and the rear face which lie in a particular position relative to each other and/or 10 are difficult to imitate or copy. WO 03/053713 Al, which defines the generic type, describes a security element which is constructed on a plastic film and carries, on both sides of the plastic films, relief structures which act as diffraction structures and for 15 example display a motif as a hologram. The relief structures are further provided with metal layers which are structured by gaps, with the result that another suitable pattern, for example a letter or another alphanumeric character, is additionally recognizable. The structured metallization on the relief structures is designed as a reflective layer, with the result that the 20 corresponding motif is visible in top view. The object of the invention is to create a security element which displays different motifs on the front and rear face and a further motif in high quality when viewed in transmitted light mode. 25 This object is achieved by a security element for security papers, value documents or the like, with a carrier, which is at least partially transparent or translucent, having an upper face and a lower face; an upper embossing lacquer layer, which is applied to the upper face and in which an upper WO 2011/000878 PCTIEP2010/059302 -3 embossed structure is formed; a lower embossing lacquer layer, which is applied to the lower face and in which a lower embossed structure is formed; an upper reflective layer, which is arranged on the upper embossing lacquer layer and has an upper reflective layer structure; and a lower reflective layer, 5 which is arranged on the lower embossing lacquer layer and has a lower reflective layer structure, wherein the lower reflective layer structure and the upper reflective layer structure together generate a visible transparency motif when viewed in transmitted light mode, and the lower reflective layer structure and the upper reflective layer structure each have a modulated line 10 grid, wherein a line direction of the upper reflective layer structure lies across a line direction of the lower reflective layer structure. The object is further achieved by a value document with such a security element. 15 Finally, the object is also achieved by a method for manufacture of a security element for security papers, value documents or the like, in which a carrier having an upper face and a lower face is provided with an upper embossing lacquer layer on the upper face and, on top of that, with an upper reflective 20 layer, and with a lower embossing lacquer layer on the lower face and, on top of that, with a lower reflective layer, wherein an upper embossed structure is formed in the upper embossing lacquer layer and a lower embossed structure in the lower embossing lacquer layer; the upper reflective layer has an upper reflective layer structure and the lower 25 reflective layer a lower reflective layer structure; and wherein the lower reflective layer structure and the upper reflective layer structure together generate a transparency motif when viewed in transmitted light mode, and the lower reflective layer structure and the upper reflective layer structure each have a modulated line grid, wherein a line direction of the upper WO 2011/000878 PCTIEP2010/059302 -4 reflective layer structure lies across a line direction of the lower reflective layer structure. The angle between the line directions should be as perpendicular as possible 5 in order to avoid undesired Moire effects. However, an angle of from 600 to 1200, preferably 700 to 1100, particularly preferably from 800 to 1000, is sufficient. The invention provides a surprisingly simply structured security element 10 which has both a front-face motif recognizable from the front face but not recognizable from the rear face, and a rear-face motif visible from the rear face but not discernible from the front face. In addition, as a result of the structures of the reflective layers, a transparency motif, visible when viewed with light passing through, is present as a further security feature. 15 The reflective layer structures are realized by modulated line grids, preferably with a line width of between 20 pm and 200 pn, particularly preferably between 50 pm and 150 pm. The orientation of the line structures on the upper and lower faces surprisingly simply avoid interfering Moir6 20 effects or locally different transmission properties by the two line grids lying across one another. The crossed line grids do not interfere with each other and provide a particularly well and clearly recognizable motif in the transparent image. 25 The combined motif is generated jointly by the upper and the lower reflective layer structure. As a result of the crossed line grids, the reflective layer structures on the upper and lower faces need not undergo elaborate registrations. Manufacture is thus considerably easier than in the case of structures which have to have a specific position relative to each other.

WO 2011/000878 PCT/EP2010/059302 -5 Through the use of a line width half-tone with crossed line directions, the upper and lower reflective structures are superimposed, without affecting each other. It is therefore easily possible to provide an independent motif for 5 each of the two reflective layer structures. Each of the resultant motifs, the upper motif which the upper reflective layer structure generates and the lower motif which is effected by the lower reflective layer structure, is well recognizable in the transparent image when the crossed line grids are superimposed. 10 A coloured layer can be provided for the reflective layer having the reflective structures. This is particularly simple if the respective reflective layer is generated by means of an etching method. A protective lacquer which covers the reflective layer (for example a metallization) at the locations where no 15 opening or gap is to be generated and provides protection against the etching means, for example a caustic solution, is usually printed on before the etching process. This protective lacquer usually remains on the structured reflective layer, i.e. the sections of the reflective layer which were not removed by the etching process. If this protective lacquer is coloured, the 20 motif generated by the respective reflective layer also has a colour effect, e.g. is coloured. At the same time, this colour effect does not occur when viewed with light passing through or when viewed from the other side. In the case of the upper and lower reflective layers it is particularly 25 advantageous to provide different colours for the respective reflective layer. The corresponding motifs then have different colour effects, whereas the transparency motif which is generated by the interaction of the two reflective layers (or one reflective layer) essentially does not display these colour effects.

WO 2011/000878 PCTIEP2010/059302 -6 In a simple construction of the security element, the motifs generated by the reflective layer structures are independent and need not be matched to each other as long as they do not superimpose in interfering manner in the 5 transparent image. In a preferred development of the security feature, a combined motif which is composed of the upper motif and the lower motif forms when the upper and lower motifs are superimposed. The half-tone elements of the upper and lower reflective layers can 10 advantageously also be designed such that the resultant transparency motif varies with the angle of view. In a first option, this can be achieved by giving the half-tone of the upper and the lower reflective layer different line widths. Moire-magnified images the appearance of which is dependent on the angle of view then form in transmitted light mode. In a second option, a known 15 shadow grid can be used, for example by a grid structure not containing a motif. At certain viewing angles, this grid structure then shadows the grid structure of the other reflective layer in which the motif is modulated. The desired transparency effect can be achieved in principle by any half-tone 20 which, on the one hand, is so small in its fineness that the half-tone elements do not strike the eye and, on the other hand, are modulated locally in its average area coverage such that the transparent motif(s) is/becomes visible. Either the density of the half-tone elements and/or the size of the half-tone elements can be modulated. The fineness of the grid at the same time ensures 25 that the upper or lower reflective layer continues to fulfil its function in conjunction with the corresponding embossed structure, or does not interfere with the latter.

WO 2011/000878 PCT/EP2010/059302 -7 Depending on the realization of the embossing lacquer layers and on the thereby-effected motifs, the respective reflective layer structure can be recognizable in top view, optionally in angled top view, in the reflective layer located on the embossing lacquer layer. If the upper reflective layer 5 structure and the lower reflective layer structure are formed such that they generate a combined motif, the corresponding part of the combined motif is seen from the front face, on which the upper reflective layer structure is located, and the part effected by the lower reflective layer structure from the lower face. 10 The embossing of the upper embossed structure or the lower embossed structure preferably takes place with embossing lacquers customary in the trade, such as are described for example as heat seal lacquer in DE 102004035979 Al, the disclosure of which is incorporated in full in this 15 respect. In principle, thermoplastic, electron beam curing or UV-curing embossing lacquer systems are suitable. As at least one embossing lacquer layer must be directly anchored on the carrier which can be in the form for example of a film, a good adhesion of the 20 embossing lacquer layer usually between 1 pm and 10 pm, preferably between 1.5 pm and 4 pm, thick is to be sought. This can be achieved by using carrier materials, e.g. film materials, with suitable pre-treatment. Examples of this are an acrylate coating combined with a corona treatment before the application of the embossing lacquer or the printing-on of 25 adhesion-promoting primers. Due to the resultant good adhesion of the embossing lacquer vis-n-vis the carrier, a pure casting method can be used for the embossing, in which the embossing lacquer is pressed into an embossing cylinder without further pre-treatment. In this way, an optimum reproduction of an embossed structure, resulting from a very good WO 2011/000878 PCT/EP2010/059302 -8 reproduction of the embossing tool, is obtained. This results in shiny embossed motifs. In a refinement, it is therefore preferred that the upper face and/or the lower 5 face is/are provided with a treatment improving the embossing lacquer adhesion. It is also preferred if the upper and/or the lower embossing lacquer layer comprises a UV-curing embossing lacquer. Such UV embossing lacquers have the further advantage that they are particularly suitable as a layer for receiving offset and die-stamping inks. They can thus 10 act as substrate for a covering, customary in banknote printing, with offset or die-stamping inks. A print-receiving layer that is, naturally, otherwise possible at any time on one face of the security element can then be dispensed with. 15 The protection by the security element is particularly great as a result of the third motif recognizable in transmitted light mode. For this, the upper and lower reflective layers do not cover the whole surface area, but are provided with motif-dependent gaps or openings, in order to form the line-half-tone type upper or lower motif. In the case of a metallic reflective layer, the 20 structuring can take place for example by demetallization using techniques known to a person skilled in the art (etching technique and washing methods). In the case of a printed reflective layer, the necessary printing ink is printed on in the form of a fine motif. 25 The security element can be in the form in particular of security threads, tear off threads, security band, security strips, patch or a label for application onto a security paper, value document or the like. In particular, the security element can span transparent areas or recesses.

WO 2011/000878 PCTIEP2010/059302 -9 By security paper is meant here in particular the not yet negotiable precursor for a value document which, in addition to the security element according to the invention, for example can also have further authenticity features (such as e.g. luminescent substances provided therein). By value documents are 5 meant here, on the one hand, documents produced from security papers. On the other hand, value documents can also be other documents and articles which can be provided with the security feature according to the invention, in order that the value documents have authenticity features that cannot be copied, whereby it is possible to check their authenticity and at the same time 10 undesired copies are prevented. By translucence or translucent is meant in this description the partial light permeability of a body, thus the property of allowing light to pass through, without being transparent. Translucence is thus to be distinguished from 15 transparency (= image or view permeability). The opposite of translucence is opacity. Within the meaning of this description, a body is translucent or transparent if the transmittance is at least 90% in the range of visible optical radiation (= light). At transmittances of between 10 and 90%, the body is partially transparent or translucent. 20 The manufacture method according to the invention can be developed such that the described preferred developments and embodiments of the security element are produced. 25 It is understood that the features mentioned above and those yet to be explained in the following are applicable, not only in the stated combinations, but also in other combinations or singly, without departure from the scope of the present invention.

WO 2011/000878 PCT/EP2010/059302 -10 The invention is explained by way of example in yet greater detail in the following with reference to the attached drawings, which also disclose features essential to the invention. There are shown in: 5 Fig. 1 a top view of a banknote with a security element 1, Fig. 2 a magnified section of a part of the section along line A-A of Fig. 1, Fig. 3 a schematic representation of a line-grid motif in an upper 10 reflective layer of the security element, Fig. 4 a line grid for a lower reflective layer of the security element and Figs. 5-8 different superimpositions of the line grids of Figs. 3 and 4. 15 The figures are not represented to scale, for better presentability. Furthermore, hatchings are sometimes not drawn in, in order to be able to represent the structure of the corresponding security element 1 more clearly. For the rest, elements which are functionally and/or structurally identical or 20 correspond with each other in different embodiments in each case have the same reference numbers in all figures, in order to avoid repetitions of description. In the following description of sectional representations, the face lying on top in the representations is called the front face of the security element. The rear face is accordingly the face lying at the bottom. This 25 convention merely serves to simplify the description and is not intended to be a limitation in respect of the structure and/or application of the security element.

WO 2011/000878 PCT/EP2010/059302 - 11 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 face of the banknote 2 shown in Fig. 1 and from the rear face of the banknote 2. 5 The security element 1 provided at the banknote 2 can also be a constituent of a security thread 19 of the banknote which, as represented by way of example in Fig. 1, is usually woven into the paper of the banknote 2 such that it is sometimes visible on the front face (the face visible in Fig. 1) and sometimes on the rear face of the banknote. It is also possible to arrange the 10 security element 1 at least partially over a window 20 provided in the banknote 2. However, these possibilities are, of course, only examples of the use of the security element 1 described below which, naturally, can also be used in another manner to protect a protected article against copying or forgery. 15 Fig. 2 shows a sectional representation through the security element 1 along the line A-A 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 formed transparent or also only translucent, as will also be explained later. 20 For the following description, the upper face 4 of the carrier 3 is located on the front face of the security element 1, the lower face 5 of the carrier on the rear face of the security element 1. On the upper face 4 and lower face 5, suitable adhesion promoters 6 and 7 respectively, which ensure that 25 subsequent layers have a strong adhesion to the carrier 3, are applied to the carrier 3. The adhesion promoter 6 or 7 can firstly be achieved by a suitable pre-treatment of the carrier or use of films with a suitable coating, such as e.g. acrylate coating combined with corona treatment, or by printing adhesion-promoting primers on.

WO 2011/000878 PCTIEP2010/059302 -12 To the faces 4, 5 of the carrier 3 being provided with adhesion promoter 6 or 7, an embossing lacquer layer 9 and an embossing lacquer layer 10, respectively, is now applied. The embossing lacquer layers 9, 10 obtained in 5 this way are now provided with an upper embossed structure 11 and a lower embossed structure 12, respectively. The embossed lacquer structures 11 and 12 can be pressed with an embossing cylinder without further pre treatments, due to the good adhesion of the embossing lacquer layers 9, 10 on the upper face 4 and lower face 5, respectively, of the carrier 3. 10 Reflective layers 8, 14 are then applied to the embossing lacquer layers 9, 10. These are preferably mirroring layers which are realized for example by a metallization (for example aluminium, copper, iron, chromium, gold, silver, etc. with optical densities of from 1.3 OD to 4.5 OD, preferably from 1.8 OD 15 to 3.0 OD are possible). Alternatively, printed shiny lacquer layers are also possible. Different reflective layers can also be combined, in order, as will also be explained, to generate desired visual appearances of the motifs offered to the viewer by the security element 1. 20 The embossed structures, in conjunction with the reflecting reflective layers 8, 14, realize an upper-face embossed motif and a lower-face embossed motif, respectively, which is visible when viewed from the front face VS or from the rear face RS, respectively. Of course, different motifs can be used by the front face VS and the rear face RS. If one of the two faces of the security element 1 25 is to be printed on, this can take place directly onto the embossing lacquer 9 or 10 if a UV embossing lacquer is used for that. This is suitable as a layer for receiving offset and die-stamping inks. Print-receiving layers which would require several work steps for the application are consequently no longer necessary.

WO 2011/000878 PCT/EP2010/059302 -13 The reflective layer 8 is provided with an upper reflective layer structure, which brings about a motif. In other words, the reflective layer 8 does not cover the whole surface area of the upper face 4 of the carrier 3, but has a 5 motif-forming, varying opacity, i.e. a pattern. This is a line half-tone. The same is true for the reflective layer 14. The density of the half-tone structure or structuring of the reflective layers is chosen such that the structure and the thereby effected motif make very little impression, if any, when viewed from the front face VS and the rear face RS. In the case of metallic reflective layers 10 8, 14, these patterns can be achieved for example by demetallization with known techniques (etching technique and washing methods). If printed reflective layers are used, the respective motif is already generated during printing by application of the printing ink. 15 As soon as light passes through, the two reflective structures of the upper reflective layer 8 and of the lower reflective layer 14 interact. In top view, in particular in angled top view, however, one sees not only are the embossed motifs generated by the embossed structures 11 and 12, but optionally recognizes additionally also the structure and thus the motif in the upper or 20 lower reflective layer 8, 14, respectively. Thus, the security element 1 provides a total of five different motifs. In addition to what has already been explained with reference to Fig. 3, the motifs recognizable in top view, in particular in angled top view, from the upper reflective layer 8 and the lower reflective layer 14 contribute as security features. 25 The security element 1 of Fig. 3 thus has an upper embossed structure 11 which delivers an embossed motif which is visible from the front face VS. From the rear face RS, another embossed motif is recognizable which is effected by the lower embossed structure 12.

WO 2011/000878 PCT/EP2010/059302 -14 However, if the security element 1 is viewed with light passing through, for example with illumination from the rear face RS and viewed from the front face VS, the structures and thus the motifs in the reflective layers 8, 14 are 5 recognized. Thus, the motif of the reflective layers appearing with light passing through is formed as a third security feature. The structures of the upper reflective layer 8 and of the lower reflective layer 14 interact when the security element 1 is viewed in transmitted light mode. For the motif worked into the upper reflective layer 8 and the lower reflective layer 14, 10 respectively, a line width half-tone can be used, preferably with a line width of between 20 pm and 200 pm, particularly preferably between 50 pm and 150 pm. Fig. 3 schematically shows the upper reflective layer structure 15 in the 15 upper reflective layer 8 of Fig. 2, and Fig. 4 shows the lower reflective layer structure 18 in the lower reflective layer 14 of Fig. 2. By way of example, for the upper reflective structure 15 in Fig. 3 two further upper motifs 16 and 17 are shown which, when the security element 1 is viewed from the front face VS, are to be recognized visually in addition to the embossed motif which is 20 introduced into the embossing lacquer layer 9 in form of the upper embossed structure 11. To simplify the representation, no motif is drawn in for the lower reflective layer structure 18. Of course, a motif similar to the upper motif 16 or 17 is usually also provided in the lower reflective layer structure 18. 25 If the line directions of the upper reflective layer structure 15 and of the lower reflective layer structure 18 were now arranged to be completely parallel, a greater or lesser interference with the discernibility of the upper motifs 16 and 17 would result, as Fig. 5 shows, depending on the registration.

WO 2011/000878 PCT/EP2010/059302 -15 Even if the line grids are slightly angled in relation to each other, which can easily happen in practice, a strong interference with the discernibility of the motifs also results in a similar way to when there is insufficient registration 5 in Fig. 5, as a corresponding Moir6 effect occurs. Fig. 6 shows this. In order to avoid such interferences with the discernibility, it is therefore ensured that the line grids of the upper reflective layer structure 15 and the lower reflective layer structure 18 lie, as far as possible, at right angles to 10 each other. As Fig. 7 shows, there are virtually no interferences with the motifs. This is also true, as Fig. 8 shows, if the orthogonality of the course of the lines is not maintained strictly, but there is a deviation from the orthogonal position. 15 In practice, it was proven that with a range of angles of between 600 and 1200 (i.e. 90 +/- 30'), preferably between 700 and 1100 and quite particularly preferably between 800 and 1000, i.e. 90 +/-100, an almost imperceptible, or at any rate tolerable, interference with the motifs which are worked into the upper reflective layer structure 15 and/or the lower reflective layer structure 20 18 through line width half-tone can be found. The more the line grids lie at right angles, the lesser any interference is. Depending on the outlay, which is possible during production, the above-named deviation from orthogonality can be tolerated. 25 The carrier 3 can be formed transparent. The image appearing when viewed in transmitted light mode is then particularly clear. If a carrier 3 that is only translucent is used, the separation of the image formed by the embossed structure 11 from the front face VS from the image brought about by the WO 2011/000878 PCTIEP2010/059302 -16 lower embossed structure 12 on the rear face RS increases at the expense of the quality of the image seen with transmitted light. If a smooth surface is desired on at least one face of the security element 1, 5 another cover layer 21 can advantageously be applied to this corresponding face. This is shown as a dotted line in Fig. 2. Such cover layers are known to a person skilled in the art, for example from the already-cited WO 03/053713 Al.

Claims

1. A security element for security papers, value documents or the like, with 5 - 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 10 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 15 lacquer layer (10) and has a lower reflective layer structure (18), characterized in that - 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 20 - 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. 25

2. The security element according to claim 1, in which the upper reflective layer structure (15) and the lower reflective layer structure (18) WO 2011/000878 PCT/EP2010/059302 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 5 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 10 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. 15

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 or the like, in which 20 - 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 25 - 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), WO 2011/000878 PCT/EP2010/059302 19 - 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), characterized in that 5 - 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 10 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 15 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 20 lacquer layer (9, 10).