AU2010268080A1

AU2010268080A1 - Security element, and method for the production thereof

Info

Publication number: AU2010268080A1
Application number: AU2010268080A
Authority: AU
Inventors: Manfred Heim; Lars Hoffmann
Original assignee: Giesecke and Devrient GmbH
Current assignee: Giesecke and Devrient Currency Technology GmbH
Priority date: 2009-07-01
Filing date: 2010-06-30
Publication date: 2012-01-19
Anticipated expiration: 2030-06-30
Also published as: DE102009031386A1; EP2448766B1; AU2010268080B2; MX2012000032A; WO2011000877A1; EP2448766A1

Abstract

The invention relates to a security element for security papers, value documents and the like, comprising the following: a carrier (3) having a upper face (4) and a lower face (7); an upper embossed lacquer layer (9), which is applied to the upper face (4) and in which an upper embossed structure (11) is formed; and a lower embossed lacquer layer (9), which is applied to the lower face (4) and in which a lower embossed structure (11) is formed. An upper reflective layer (8) lies between the upper face (4) of the carrier (3) and the upper embossed lacquer layer (9).

Description

WO 2011/000877 PCT/EP2010/059301 Security element, and method for the production thereof 5 The invention relates to a security element, as well as a method for the production thereof. 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 10 serves as protection against unauthorized reproduction. 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 15 tickets, credit cards, health insurance cards, etc.) as well as product security 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 20 the rear face which lie in a particular position relative to each other and/or are difficult to imitate or copy. WO 2008/017362 A3 describes various methods for the production of optically variable films, in which one optically variable motif (i. e. an image 25 dependent on the viewing conditions, e.g. the viewing direction) is visible on the front face and another is visible on the rear face, and also a third motif is visible when viewed with light passing through or in transmission. The production methods relate to structures of topographically different height, followed by demetallization of metal layers as well as mask imaging 30 methods in which data on the front face form a mask for the pattern generation on a rear face. Different variants of optically variable patterns for WO 2011/000877 PCT/EP2010/059301 -2 a security element which appear different, thus form different motifs, when viewing the front or rear face of the security element are known from WO 2006/133863 A2. 5 WO 03/053713 Al 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 example display a motif in form of a hologram. The relief structures are further provided with metal layers which are structured by gaps, with the result that another suitable pattern, 10 for example a letter or any alphanumeric character, is additionally recognizable. The structured metallization on the relief structures is designed as a reflecting layer, with the result that the corresponding motif is visible in top view. 15 The object of the invention is to provide a security element which displays different motifs on the front and rear face, but is still easy to produce, in particular without elaborate registrations. Furthermore, the security element should preferably also make it possible to make a motif easily discernible when viewed with transmitted light. 20 This object is achieved by a security element for security papers, value documents or the like, which security element comprises: a carrier 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 embossed structure is 25 formed; and a lower embossing lacquer layer, which is applied to the lower face and in which a lower embossed structure is formed, wherein an upper reflective layer is arranged between the upper face of the carrier and the upper embossing lacquer layer.

WO 2011/000877 PCT/EP2010/059301 -3 The object is further achieved by a value document comprising such a security element. Finally, the object is also achieved by a method for the production of a 5 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 reflective layer on the upper face and, on top of that, with an upper embossing lacquer layer, and with a lower embossing lacquer layer on the lower face, wherein an upper embossed structure is formed in the upper 10 embossing lacquer layer and a lower embossed structure in the lower embossing lacquer layer. The invention provides a surprisingly simply structured security element which has both a front-face motif recognizable from the front face but not 15 recognizable from the rear face, and a rear-face motif visible from the rear face but not discernible from the front face. As the front-face and rear-face motifs respectively are not visible from the other side, a registration of the two motifs relative to each other is not necessary. The separation of these two motifs is achieved by having the upper reflective layer located between the 20 upper embossing lacquer layer and the lower embossing lacquer layer. The reflective layer reflects incoming light. As, unlike in WO 03/053713 Al, the upper reflective layer does not rest directly on the embossed structure, as is also the case with usual hologram films, the front-face motif is to be recognized only from the front and the rear-face motif only from the rear 25 face. The embossed structures preferably interact with the reflective layer, e.g. exploiting a diffractive or holographic effect. However, embossed structures WO 2011/000877 PCT/EP2010/059301 -4 that use other effects are equally possible, e.g. microlenses, micro-concave mirrors, sawtooth structures, satin structures, etc. If the presence of separate front- and rear-face motifs is enough for the 5 security element, the upper reflective layer is to be implemented covering the whole surface area. This can be for example a metallization over the whole surface area, comprising aluminium, copper, iron, chromium, gold or silver, etc. Alternatively or in addition, a printed shiny lacquer layer is also suitable as reflective layer. Naturally, different reflective layers can also be combined 10 in order to give the front-face motif or rear-face motif a desired visual appearance, for example a desired colour effect. The embossing of the upper embossed structure or the lower embossed structure preferably uses embossing lacquers customary in the trade, such as 15 are described for example as heat seal lacquer in DE 102004035979 Al, the disclosure of which is incorporated in full in this respect. In principle, thermoplastic, electron beam curing or UV-curing embossing systems are suitable. 20 As at least one embossing lacquer layer must be directly fixed to the carrier which can be in the form for example of a film, a good adhesion of the embossing lacquer layer usually between 1 pm and 10 pm, preferably between 1.5 pm and 4 pLm, thick is to be sought. This can be achieved by using carrier materials, e.g. film materials, with suitable pre-treatment. 25 Examples of this are an acrylate coating combined with a corona treatment before the application of the embossing lacquer or the printing-on of adhesion-promoting primers. Due to the resultant good adhesion of the embossing lacquer vis-A-vis the carrier, a pure casting method can be used for the embossing, in which the embossing lacquer is pressed into an WO 2011/000877 PCT/EP2010/059301 -5 embossing cylinder without further pre-treatment. In this way, an optimum reproduction of an embossed structure, resulting from a very good reproduction of the embossing tool, is obtained. This results in shiny embossed motifs. 5 In a refinement, it is therefore preferred that the upper face and/or the lower 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 has a UV-curing embossing lacquer. Such UV-embossing 10 lacquers have the further advantage that they are particularly suitable as a layer for receiving offset and die-stamping inks. They can thus 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 structure according to the invention of the security element with internal reflective layer has several advantages. Firstly, the reflective layer is flat, which improves its reflective properties. Secondly, it is well protected by the carrier and the embossed lacquer layer lying over it. Thus, a good chemical 20 resistance and scratch-proofing are achieved. The motif discernible from the upper face through the upper embossed structure can be designed in the form of a hologram, the same is true for the motif, discernible from the lower face, which the lower embossed structure 25 provides. If the reflective property of the internal reflective layer is of importance for this hologram effect or also for a different optical effect, the interaction of the embossed structure and reflective layer can advantageously be provided with a colour effect if a coloured layer is provided between the embossed structure and the reflective layer. The corresponding motif which WO 2011/000877 PCT/EP2010/059301 -6 is provided by the upper or the lower embossed structure then appears to be affected by the coloured layer, as the reflective radiation is coloured. A hologram can be provided e.g. with a colour effect. 5 The protection by the security element can be further increased if the upper reflective layer is structured with an upper motif which is then visible combined with an at least partially transparent or translucent carrier when viewed with transmitted light. For this, the upper reflective layer is not implemented over the full surface area, but is provided with motif 10 dependent gaps or openings. In the case of a metallic reflective layer, this can take place for example by demetallization using techniques known to a person skilled in the art (etching technique or washing methods). In the case of a printed reflective layer, the necessary printing ink is printed on in the form of a fine motif. For this case, the separation of the embossed motifs can 15 in principle be impaired by the openings in the reflective layer. In order to avoid this, the structure of the openings/ gaps is preferably made sufficiently fine. In addition or optionally, this separation can be improved by the carrier being only translucent, but not transparent. 20 Additionally, a further reflective layer can also be applied and structured between the lower face of the carrier and the lower embossed lacquer layer, which offers further possibilities when viewed with transmitted light, as the motifs of this lower reflective layer and of the upper reflective layer then form a combined motif when viewed with light passing through. 25 The above-mentioned colour effect can also be generated when structuring the upper and/or the lower reflective layer. This is particularly simple when the respective reflective layer is generated by means of an etching method. A protective lacquer which covers the reflective layer (for example a WO 2011/000877 PCT/EP2010/059301 -7 metallization) at the points where no opening or gap is to be incorporated 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 5 the reflective layer which were not removed in the etching process. If this protective lacquer is coloured, the motif generated by the respective embossed lacquer layer in conjunction with the 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 10 other side. In the variant with an upper and a lower reflective layer it is particularly advantageous to provide different colours between the respective reflective layer and the associated embossed structure. The corresponding motifs then 15 have different colour effects, whereas the motif viewable with transmitted light which is generated by the interaction of the two reflective layers (or one reflective layer) essentially does not display these colour effects. For the upper motif and, if there is one, the lower motif, in each case a half 20 tone structure lends itself e.g. to the use of a modulated line grid, wherein a line width varying between 20 pm and 200 pm, preferably between 50 Pm and 150 pm, can be used. It was shown that interfering Moire effects or locally different transmission properties can easily be avoided if the two line structures lie at an angle of between 80* and 1000 to each other. It is therefore 25 preferred that the lower motif and the upper motif are each produced by a half tone structure, e.g. a modulated line structure, wherein the line direction of the upper motif preferably lies across, in particular at an angle of from 60* to 1200, preferably 700 to 1100, particularly preferably from 800 to 1000, to the line direction of the lower motif. Line structures crossed in this way interfere WO 2011/000877 PCT/EP2010/059301 -8 with each other particularly little, or not at all, and allow particularly well and clearly recognizable motifs in the transparent image. The half tone elements of the upper and lower reflective layers can 5 advantageously also be designed such that the motif resultant in transmitted light mode depends on the angle of view. In a first variant, this can be achieved by giving the half tone structure of the upper and the lower reflective layer different grid widths. Moire-magnified images the appearance of which is dependent on the angle of view then form in 10 transmitted light mode. In a second variant, a known shadow grid can be used, for example by a half tone structure not containing a motif. At certain viewing angles, this structure then shadows the half tone structure of the other reflective layer which modulates the motif. 15 The desired transparent effect can be achieved in principle by any half tone 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, is 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 20 elements can be modulated. The fineness of the half tone at the same time ensures that the upper or lower reflective layer continues to fulfil its function in conjunction with the embossed structure respectively lying over it in viewing direction. 25 The security element can be in the form in particular of a security thread, tear-off thread, security band, security strip, 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 2011/000877 PCT/EP2010/059301 -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 prevent undesired copies. 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 production 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 2011/000877 PCT/EP2010/059301 -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 view of the section along line A-A of Fig. 1, Fig. 3 a sectional view similar to Fig. 2 of a further embodiment of the 10 security element of Fig. 1, Fig. 4 a sectional view similar to Fig. 2 of a further embodiment of the security element of Fig. 1, 15 Fig. 5 a schematic representation of a line-type half tone motif in an upper reflective layer of the security element, Fig. 6 a line grid for a lower reflective layer of the security element and 20 Figs. 7-10 different superimpositions of the line-type half tones of Figs. 5 and 6. The figures are not represented to scale, for better presentability. Furthermore, hatchings are sometimes not drawn in, in order to be able to 25 represent the structure of the corresponding security element 1 more clearly. Moreover, elements which are functionally and/or structurally identical or 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 WO 2011/000877 PCT/EP2010/059301 -11 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 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 5 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 face of the banknote 2 shown in Fig. 1 and from the rear face of the banknote 2. 10 The security element 1 provided on the banknote 2 can also be part 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 shown in Fig. 1) and sometimes 15 on the rear face 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. 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. 20 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 can be formed transparent or also only translucent, as will also be explained later. 25 For the following description, the upper face 4 of the carrier 3 is the front face of the security element 1, the lower face 5 of the carrier is 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 subsequent layers have a WO 2011/000877 PCT/EP2010/059301 -12 strong adhesion to the carrier 3, are applied to the carrier 3. The adhesion promoter 6 or 7 can in one option 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, in another option, by printing adhesion 5 promoting primers on. A reflective layer 8 is then applied to the upper face 4 of the carrier 3 provided with adhesion promoter 6. This reflective layer 8 is preferably a mirroring layer which is realized for example by a metallization (for example aluminium, copper, iron, chromium, gold, silver, etc. with optical densities of from 1.38 OD to 4.5 OD, preferably from 1.8 OD to 3.0 OD 10 are considered). Alternatively, a printed shiny lacquer layer is 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. 15 An embossing lacquer layer 9 and an embossing lacquer layer 10, respectively, is now applied to the reflective layer 8 as well as to the lower face 5, provided with adhesion promoter 7, of the carrier 3. The embossing lacquer layers 9, 10 obtained in this way are now provided with an upper embossed structure 11 or a lower embossed structure 12. The embossed 20 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. The embossed structures, in conjunction with the reflecting reflective layer 8, realize an upper-face embossed motif and a lower-face 25 embossed motif, respectively, which are 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 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 this. This is WO 2011/000877 PCT/EP2010/059301 -13 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. 5 Fig. 3 shows a development of the security element of Fig. 1, wherein the layered structure substantially corresponds to that explained with reference to Fig. 2. However, the reflective layer 8 is now additionally also provided with a reflective layer structure, which brings about a motif. In other words, the reflective layer does not cover the surface area of the upper face 4 of the 10 carrier 3 totally, but has a motif-forming, varying opacity, i.e. a pattern. This can be generated e.g. by a half tone. The half tone density of the half tone structure or structuring of the reflective layer 8 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 a 15 metallic reflective layer 8, this structure can be achieved for example by demetallization with known techniques (etching technique and washing methods). If a printed reflective layer 8 is used, the motif is already generated during printing by application of the printing ink. 20 The security element 1 of Fig. 3 thus has an upper embossed structure 11 which provides an embossed motif which is visible from the direction of the front face VS. From the rear face RS, another embossed motif is recognizable which is effected by the lower embossed structure 12. 25 However, if the security element 1 is viewed with transmitted light, for example with illumination from the rear face RS and viewed from the front face VS, the pattern is recognized, and thus the structure in the reflective layer 8 and the thereby effected motif. Thus, the motif appearing in see through mode is formed as a third security feature in the reflective layer 8.

WO 2011/000877 PCT/EP2010/059301 -14 Fig. 4 shows a development of the security element 1 of Fig. 3, wherein a lower reflective layer 14 which is provided with a lower reflective layer structure is now additionally also provided on the lower face 5 of the carrier 5 3. In see-through mode the two reflective layer structures of the upper reflective layer 8 and of the lower reflective layer 14 interact. In top view, in particular in skew top view, however, not only are the embossed motifs generated by the embossed structures 11 and 12 seen, but optionally additionally also the pattern in the upper or lower reflective layer 8, 14 can 10 be recognized, wherein, naturally, different patterns can in turn be worked into the structure here. Thus, the security element 1 provides a total of five different motifs. The motifs which have already been explained with reference to Fig. 3 are complemented by security features in form of the motifs recognizable in top view, in particular in skew top view, from the 15 upper reflective layer 8 and the lower reflective layer 14. As already mentioned, the structures of the upper reflective layer 8 and of the lower reflective layer 14 interact when the security element 1 is viewed with transmitted light. For the motif worked into the upper reflective layer 8 20 or the lower reflective layer 14 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. 5 schematically shows the upper reflective layer structure 15 in the 25 upper reflective layer 8 of Fig. 4, and Fig. 6 shows the lower reflective layer structure 18 in the lower reflective layer 14 of Fig. 4. By way of example, for the upper reflective structure 15 in Fig. 5 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 WO 2011/000877 PCT/EP2010/059301 -15 introduced into the embossing lacquer layer 9 through the upper embossed structure 11. To simplify the representation, no motif is shown in for the lower reflective structure 18. Of course, a motif similar to the upper motif 16 or 17 is usually also formed by the lower reflective layer structure 18. 5 If the line directions of the upper reflective layer structure 15 and of the lower reflective layer structure 18 were now arranged completely parallel, a greater or lesser interference with the discernibility of the upper motifs 16 and 17 would result, as Fig. 7 shows, depending on the registration. 10 If the line half tones are still 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 in Fig. 7, as a corresponding Moire effect occurs. Fig. 8 shows 15 this. In order to avoid such interferences with the discernibility, it is therefore ensured in a development that the line half tones of the upper reflective layer structure 15 and the lower reflective layer structure 18 lie, as far as possible, 20 at right angles to each other. As Fig. 9 shows, there are virtually no interferences with the motifs. This is also true, as Fig. 10 shows, if the orthogonality of the course of the lines is not maintained, but there is a deviation from the orthogonal position. 25 In practice, it was shown that with a range of angles of between 60* and 120* (i.e. 90* +/- 300), preferably between 700 and 1100 and quite particularly preferably between 80* and 1000 (i.e. 900 +/-10*), 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 WO 2011/000877 PCT/EP2010/059301 -16 18 through line width half tone is to be ascertained. The more the line half tones 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. 5 The carrier 3 can be provided transparent. The image appearing when viewed in see-through 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 10 lower embossed structure 12 on the rear face RS increases at the expense of the quality of the image with light passing through.

Claims

1. Security element for security papers, value documents or the like, which security element comprises: 5 - a carrier (3) having 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 (11) is formed, - a lower embossing lacquer layer (10) which is applied to the lower face (5) and in which a lower embossed structure (12) is formed, 10 - wherein an upper reflective layer (8) is arranged between the upper face (4) of the carrier (3) and the upper embossing lacquer layer (9).

2. Security element according to claim 1, in which at least one of the upper face (4) and the lower face (5) is provided with a treatment improving 15 the embossing lacquer adhesion.

3. Security element according to one of the above claims, in which at least one of the upper and lower embossing lacquer layer (9, 10) comprises a UV-curing embossing lacquer. 20

4. Security element according to one of the above claims, in which the carrier (3) is at least partially transparent or translucent, and in which the upper reflective layer (8) has an upper reflective layer structure (15) which generates a motif visible when viewed in see-through mode. 25

5. Security element according to claim 4, in which the upper reflective layer (8) is half tone modulated to provide the motif visible when viewed in see-through mode. WO 2011/000877 PCT/EP2010/059301 - 18

6. Security element according to one of the above claims, in which a lower reflective layer (14) is arranged between the lower face (5) of the carrier (3) and the lower embossing lacquer layer (10). 5

7. Security element according to claims 4 and 6 or 5 and 6, in which the lower reflective layer (14) has a lower reflective layer structure (18) which, together with the upper reflective layer structure (14), brings about a combined motif when viewed in see-through mode. 10

8. Security element according to claim 7, in which the lower and the upper reflective layer structure (18, 14) are each generated by a modulated line half tone, wherein the line direction of the upper reflective layer structure (14) lies across, in particular at an angle of from 80 to 100 degrees, the line direction of the lower reflective layer structure (18). 15

9. Security element according to claim 4 or according to one of the above claims in conjunction with claim 4, in which the carrier (3) is provided translucent or with a matting coating. 20

10. Value document with a security element according to one of claims 1 to 9.

11. Method for the production of a security element for security papers, value documents or the like, in which 25 - a carrier (3) having an upper face (4) and a lower face (7) is provided with an upper reflective layer (8) on the upper face (4) and, on top of that, with an upper embossing lacquer layer (9), and with a lower embossing lacquer layer (10) on the lower face (4), wherein WO 2011/000877 PCT/EP2010/059301 -19 - an upper embossed structure (11) is formed in the upper embossing lacquer layer (9) and a lower embossed structure (12) in the lower embossing lacquer layer (9). 5

12. Production method according to claim 11, 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.

13. Production method according to one of the above method claims, in 10 which a UV-curing embossing lacquer is used for at least one of the upper and lower embossing lacquer layer (9, 10).

14. Production method according to one of the above method claims, in which the upper reflective layer (8) is provided with an upper reflective layer 15 structure (15).

15. Production method according to claim 14, in which the upper reflective layer (8) is half tone modulated to provide the motif visible when viewed in see-through mode. 20

16. Production method according to one of the above method claims, in which the lower face is provided with a lower reflective layer (14) before application of the lower embossing lacquer layer (10). 25

17. Production method according to claim 16, in which the lower reflective layer (14) is provided with a lower reflective layer structure (18).

18. Production method according to claim 17, in which a modulated line half tone is generated for the lower and the upper reflective layer structure WO 2011/000877 PCT/EP2010/059301 - 20 (18, 14), wherein the line direction of the upper reflective layer structure (18) lies across, preferably at an angle of from 80 to 100 degrees, the line direction of the lower reflective layer structure (15).