WO2016096095A1

WO2016096095A1 - Value document

Info

Publication number: WO2016096095A1
Application number: PCT/EP2015/002415
Authority: WO
Inventors: Hans Lochbihler
Original assignee: Giesecke & Devrient Gmbh
Priority date: 2014-12-15
Filing date: 2015-12-01
Publication date: 2016-06-23
Also published as: DE102014018551A1

Abstract

The invention relates to a value document, such as a bank note, a check, a credit card or another payment card, an identification card, or the like, which has a front side (9) and a back side (10), displays an image (3) recognizable by the unaided eye in the top view, at least from the front side, has specific dimensions (B, H) in the top view, and has a multi-layered substrate body (2) which, in the top view, has the specific dimensions (B, H) and is structured from at least one first and one second transparent film (11, 12), each also having the specific dimensions (B, H) in the top view and being connected to each other by an intermediate layer (13) such that inner sides of the films (11, 12) are oriented toward each other and outer sides of the films (11, 12) are oriented away from the intermediate layer (13), wherein the outer side of the first film (11) is oriented toward the front side (9) and the outer side of the second film (12) is oriented toward the back side (10). The image (3) which is recognizable from the front side (9) is produced by a first embossed structure (14), which is metallized at least in sections and which is arranged on the inner side of the first film (9) and designed at least in sections as a sub-wavelength structure (17) which has a lateral, i.e. crosswise to the top view direction, varying profiling and/or periodicity. The outer side of the first film (11) and a front side of the intermediate layer (13) oriented toward the first film (11), forming the front side (9), are free of imprinting contributing to the image (3).

Description

W e r t d o k m e n t

The invention relates to a document of value, such as a banknote, a check, a credit or other payment card, an identity card or the like, which has a front and a back, in plan view at least from the front shows a recognizable with the unaided eye representation, in the plan view has certain dimensions and has a multi-layer substrate body which has the certain dimensions in the plan view and is composed of at least a first and a second transparent film, each also in the plan view of the specific dimensions and which together by an intermediate layer are connected so that inner sides of the films facing away from each other and outer sides of the films from the intermediate layer, wherein the outside of the first film to the front and the outside of the second film to the back.

Banknotes undergo relatively many, different production steps in their production. Banknote paper is provided with illustrations by elaborate printing processes and is also colored. Security threads are produced on film as semi-finished goods and later embedded in the production of the banknote paper. Watermarks are incorporated in the banknote paper. Furthermore, film-based security features, eg. As holograms, optically variable elements and / or transparent windows integrated into banknotes. They are first produced on foil and later applied to the banknote paper. Foil elements give banknotes additional security against counterfeiting. However, their register-accurate integration with regard to the print image and the watermark is technically difficult. Therefore suffers Banknote design many times with regard to the lack of registration accuracy of these different banknote elements. There is also the risk that foil elements will come off when a banknote is being circulated. Currently, there are banknotes with different substrates. Paper, polymer and mixed forms of paper and polymer in the form of so-called hybrid banknotes are known. For each type of banknote, special process steps are required to apply security elements to the banknote paper or to generate security notes when printing the banknotes on the banknote paper. In the case of polymer banknotes, the color shingles during the circulation is problematic.

The problems and requirements mentioned are not limited to bank notes, i. paper or foil-based documents of value, but also for payment cards or identification cards. The term

"Value document" is therefore understood here to include sheet-like value documents, such as banknotes, checks, etc., as well as comparatively rigid value documents, such as security, ID or payment cards.

It is known that colored images or motifs can be generated in reflection or transmission by sub-wavelength structures. This refers to periodic structures whose period is in the range of 150 nm to 500 nm, or aperiodic structures whose structural size is also in this order of magnitude. Different approaches for generated with it

For example, color effects can be found in Y. Yu, L. Wen, S. Song, and Q. Chen, "Transmissive / Reflective Structural Color Filters:"

Theory and Applications, "Journal of Nanomaterials, vol. 2014, Article ID 212637, 17 pages, 2014. doi: 10.1155 / 2014 / 212637. From DE 102011115589 AI, WO 2012/156049 Al and the publication H. Lochbihler, "CoLored images generated by metallic subwavelength gratings," Opt. Express 17, 12189-12196 (2009) are known one-dimensional or two-dimensional periodic subwavelength structures in lattice form, the can be duplicated by a stamping process from an original to transparencies. Metallization of such structures produces color effects with high contrast. The metallized structures are embedded in a transparent dielectric, wherein the refractive index of the embossed structure is approximately identical to the refractive index of the dielectric substrate. In this way, the sub-wavelength structure is protected against environmental influences.

The use of such subwavelength structures for security elements of value documents is known from WO 2014/023415 Al and DE 102009012300 AI.

With embossed structures, incident radiation can be absorbed to provide a background for an image. EP 1434695 B1 describes an absorbent structure with a period smaller than the wavelength of light. The structure is constructed as a cross lattice with a sinusoidal profile. WO 2005/106601 A2 relates to moire magnification arrangements with microimages, which consist of antireflective areas and partially reflective areas. The antireflecting surface is formed by nanostructures with a period smaller than 700 nm and a depth between 150 nm and 350 nm. EP 1476317 A1 and US Pat. No. 7,468,842 B2 describe concave or convex surfaces, picture elements as relief surfaces which are filled with color, and "light trap patterns" formed by sub-wavelength structures for generating microimages for moiré magnification arrangements DE 102008046128 AI is a Matt structure for a security element is known, which has a plurality of microelements each with a lateral dimension below 50 μπ \, wherein at least one geometry parameter of the microelements varies randomly to produce the matte effect. The geometry parameter can be the depth of the microelements.

WO 2005/095119 A1 describes a security element in the form of a multilayer film body, which shows an angle-dependent color shift effect by means of interference. In this case, a relief structure is formed in a replication lacquer layer, which is designed with regard to its geometry in such a way that the color shift effect is produced only in individual sections. For this purpose, the aspect ratio of the relief structure is varied.

DE 102006050047 AI describes a see-through security element with microstructures, which are designed as micro cavities, which have a distance of 1 μπι from each other.

The invention has for its object to provide a document of value, in which film-based security elements can be easily combined with security elements that are generated by displaying images, etc., in particular without the above-mentioned Passerprobleme. Another object of the invention is to provide a document of value that is particularly durable while in circulation. This object is achieved by a value document, such as a banknote, a check, a credit or other payment card, a badge or the like, which has a front and a back, in top view at least from the front recognizable with the unaided eye representation shows, in plan view certain dimensions has and has a multi-layered substrate body, which has the certain dimensions in the plan view and is composed of at least a first and a second transparent film, each also in the plan view of the particular dimensions and which are interconnected by an intermediate layer, so that inner sides of the foils facing each other and outsides of the foils away from the intermediate layer. In this case, the outer side of the first film points towards the front side and the outer side of the second film toward the rear side, wherein the representation recognizable from the front side is produced by a first, at least partially metalized embossed structure, which is arranged on the inside of the first film, at least is formed in sections as a sub-wavelength structure, which has a laterally, ie transversely to the top view direction, varying profiling and / or periodicity. The outer side of the first film forming the front side and a front side of the intermediate layer facing the first film are free of imprints which contribute to the representation.

The invention deviates fundamentally from the prior art procedure, which basically assumed a print-based representation on the work document and combined this print-based representation with film-based security elements, and now exclusively uses the embossed structure to produce both the representation and further security features , Of conventional foil-based banknotes or hybrid banknotes, the value document according to the invention differs in that the usually pressure-based representation is now produced by the embossing structure, which is why the outsides of the foils and also the interlayer between the foils are free of imprints which would produce the representation , The invention now surprisingly uses the subwavelength structures known per se. The embossed structure, which is designed as a sub-wavelength structure, extends over the entire dimensions of the value document and generates the representation similar to a printed image. This approach not only achieves particularly stable circulation of valuable documents, but also achieves an outstanding registration accuracy between the representation on the security element and other security elements that imperatively require the use of a film, such as holograms, window-use security features, etc. This combination effect makes the invention particularly valuable.

Subwavelength structures have dimensions in the nanometer range. The printed image of conventional banknotes is perceived by a viewer in reflection. The light is diffusely scattered on the color pigments of the printed image. The value documents according to the invention reflect the incident light primarily in the glancing angle. In addition, the representation of the value document, for example the banknote motif, becomes observable in the first diffraction order of the reflection. In a periodically formed sub-wavelength structure, a viewer sees a subject in a certain color in the glancing angle, which is perceptible in a wide range of angles. The subwavelength structure can be designed such that the color remains constant for different viewing angles or-as an alternative variant-changes. In contrast to true color holograms, their colors are not formed from pure spectral components but from relatively broadband resonance peaks in the visible light spectrum. This color characteristic comes very close to the color spectrums of pigment inks and does not suffer as little as hologram structures Replacing the printed image of banknotes with such embossed structures, which are designed as subwavelength structures, considerably increases the security against forgery of the document of value, because the period of the subwavelength gratings can be selected such that oblique illumination - equivalent to a pronounced tilting of the document The reflec- tion of the first order of diffraction can be perceived by each person quickly and without any aids, and in this constellation, the banknote image can be perceived in the spectral colors.However, these diffraction properties of the embossed structures can be carried out using common tools such as color copying, etc. In addition, the resolution of images produced by subwavelength gratings is higher than that of conventional printing processes, which enables the density of information described herein to be increased e Design of banknote surfaces in comparison to conventional methods, which also leads to an increase in counterfeit security.

In addition, the embossed structure allows viewing windows or semitransparent areas in the value document to be provided in different ways. Different transparent areas can be easily perceived by a viewer in transmitted light and are also difficult to imitate.

The invention uses surface-structured banknotes over the entire surface, which display to a viewer a representation produced by the subwavelength structures. The conventional printed image of a value document, for example a banknote, is modeled by the subwavelength structure with the lateral variation of profile / periodicity. The subwavelength structures provide the representation not only in specular Reflection, but in the first diffraction order. They are designed so that the representation over a wide viewing angle range, which is almost or completely the same as a conventional print image, recognizable.

The fact that the printed image of the value document is reproduced by full-surface embossed and metallized nanostructures, the conventional printing process in the banknote production is superfluous. The embossed structure lies on the inside of the film and is therefore robust against environmental influences. In addition, all desired security features such as holograms, micromirrors etc. can be produced in a single embossing step with the sub-wavelength structure that generates the printed image. Furthermore, it is possible to easily see through windows in the case of visual / see-through effects. The production of the value document is thus significantly simplified. The appearance of the first diffraction order increases the security against counterfeiting over conventional banknotes.

As already mentioned, the value document according to the invention makes it possible with the embossing structure to produce not only the subwavelength structure but also other structures which are required for film-based security features in the same production process. It is therefore preferable that the embossed structure has a periodicity of 150 nm to 500 nm in the portions in which it is formed as a sub-wave structure, or aperiodic with a feature size of 150 nm to 500 nm. The profile of the embossed structure may be a rectangular profile or sine grid or intermediate forms of these two geometries, wherein the profile type varies laterally to produce the representation. It is also possible, at least in sections, to form the embossed structure as a moth-eye structure. Under it understands a black background generating structure, as explained at the beginning of the prior art.

One example of a film-based security element that is produced by the embossed structure is to form the embossed structure at least in one region as a microstructure with a period of 500 nm to 2 μm or aperiodically in order to represent a hologram or a matt structure.

The representation is produced by the embossed structure, which is arranged on the foil lying on top in the viewing direction and there on the inside. In order to avoid an effect by the film lying down in the viewing direction, it is preferable for the intermediate layer to be at least partially opaque. In the sections provided with an opaque intermediate layer, the representation is then effected exclusively by the embossing structure on the film lying overhead in the viewing direction. Of course, it is possible to laterally structure the interlayer in terms of opacity, for example to create a deliberate interaction between supervisory and see-through effects. In a particularly preferred embodiment, both films are provided on their insides with metallized embossed structures, ie the value document shows in plan view from the back another recognizable with the unaided eye representation, which is produced by a second, at least partially metallized embossed structure, which the inner side of the second film is arranged and which is at least partially formed as a sub-wavelength structure with laterally varying profiling and / or periodicity. The outer side of the second film forming the rear side and the rear side of the intermediate layer facing the second side are then free of imprints which contribute to the further illustration. One such designed value document then generates both on the front and on the back in each case a representation exclusively by the embossed structure. Even a value document designed in this way no longer requires any printing process during the production.

In a preferred embodiment, the first and second embossing structures form a solid in opposite regions. For this window, the metallization of the embossed structures is relevant. In the window area preferably no metallization is provided. This can be achieved in that the metallization is not applied from the beginning in the window area or that a metallization is subsequently removed again in the window area, for example by removal with a laser or the use of a so-called wash ink. Both means are known to those skilled in the art.

It is also possible to provide in the region of the window on both inner sides of the foils metallized embossed structures which show a motif in plan view from the front and the back and release parts of the window so that the embossed structures in view of a motif he - whole.

Further, with the use of a window, it is possible to use an asymmetrical profile for the metallized first or second embossing pattern, which is designed such that the respective embossing pattern generates, in reflection, a motif that disappears in a transparent manner. Such a design is known from the cited references for nanostructures or sub-wavelength structures. It is particularly easy to apply here, since both the formation of the window and the corresponding motifs, which appear in plan view or Durchsicht, with one and the same embossing process This embossing process also produces the basic representation of the value document. A demetallization can then be omitted under certain circumstances. In a simplest case, the intermediate layer can consist of a dielectric with which the inner sides of the films are laminated. It is also possible to design the value document as a so-called hybrid value document, for example as a hybrid banknote, if the intermediate layer comprises a banknote paper. Particularly preferred here is a banknote paper which has a watermark, the embossing structures forming a window in the area above the watermark. This will make the watermark visible through the window.

An additional color effect of the representation can be achieved in that there is a color layer on the film or films or the film is / are colored. Alternatively or additionally, it is possible to color the intermediate layer.

Banknotes are examples of value documents that are individualized. You have a serial number. This serial number can be individually written for each bill in the metallized area provided for this purpose in the value document according to the invention with pulsed laser radiation, in that the metal is removed or converted at the irradiated points. This process preferably takes place at the end of the banknote production, ie after the lamination of the front and back of the banknotes.

Within the meaning of this description, metallization is to be understood as meaning a coating which consists of metal or contains the metal. Also is one Layer structure possible, which consists of a composite layer that has metal deposits. But it can also consist of a multi-layer structure in which one or more layers are metallic. For the production of the value document by means of embossing process, in particular photolithographic processes, for. Electron beam method, laser direct exposure, focused ion beam exposure method etc. The original of the embossed structure is written in a substrate coated with photoresist and then the exposed portion of the photoresist is removed. For example, Ormocer) and thus an embossing die is produced as a master, with which then an embossing cylinder for the embossing of a film web is produced.The structure is finally about a stamping process in UV varnish on film or directly (eg., By hot stamping in the surface of the film) replicates.

Subsequently, the metallization of the embossed film surface, z. B. with a simple metal layer and / or with a multilayer structure, for. B. an interference layer structure to enhance the color effect. These include electron beam vapor deposition, sputtering or thermal evaporation under vacuum. Finally, the films which form the front and the back of the banknote are laminated together with the intermediate layer. 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,

Fig. 2-12 are schematic sectional views through a substrate body of

Bank note of Fig. 1, wherein the sectional views relate to different embodiments.

FIG. 1 shows schematically a bank note 1 surface-structured with nanostructure, which is constructed from a substrate body 2, which has a height H and a width B. The substrate body 2 is provided on inner surfaces with an embossed structure, which at least partially provides a sub-wavelength structure. This will be explained in more detail below with reference to the sectional views of FIGS. 2 to 12, which show various embodiments of the embossing structure.

The banknote 1, which is an example of a value document, provides an observer from the front, which is shown in Fig. 1, a representation 3, as is customary for banknotes. The representation 3 may comprise, for example, a graphically designed background 4, an image 5, a hologram 6, a value 7 and a serial number 8. It is also possible to provide a window 19 in which the banknote is partially transparent. For example, see-through effects may be present in the window 19, ie, a motif visible on the front side is supplemented with a motif visible on the rear side in view of another motif. The substrate body 2 with the height H and the width B is made up of at least two films of the same dimensions, as the sectional view of FIG. 2, which shows an embodiment for the banknote 1, shows in more detail. In the sectional view of Fig. 2 is a top 9, which can be seen in Fig. 1, top, and a back 10 is below. The substrate body 2 comprises a first film 11, the outwardly facing surface of which forms the front side 9, and a second film 12, the outside of which forms the rear side 10. Between the first film 11 and the second film 12 is located as an intermediate layer, a dielectric 13th

A first embossed structure 14 is formed on the inside of the first film 11 and a second embossing structure 15 on the inside of the second film 12. The embossed structures reproduce the printed image of the illustration 3 of the banknote 1 by producing a sub-wavelength structure with a laterally varying profile and / or laterally varying periodicity. Details for the

Execution of the sub-wavelength structure can be found in the already mentioned references: DE 102011115589 AI, WO 2012/156049 AI,

WO 2014/023415 Al, DE 102009012300 Al, Y. Yu, L. Wen, S. Song, and Q. Chen, "Transmissive / Reflective Structural Color Filters: Theory and Applications," Journal of Nanomaterials, vol. 2014, Article ID 212637, 17 pages, 2014. doi: 10.1155 / 2014/212637 and H. Lochbihler, "Colored images generated by metallic subwavelength gratings," Opt. Express. 17, 12189-12196 (2009). With regard to the structure of the sub-wavelength structures, the disclosure content of these publications is fully incorporated here.

As can also be seen from these publications, to form an image it is necessary for the embossed structures to be metallised. In the area of the window 19, this metallization is restored after application. been removed or not available from the beginning. The distance can z. B. by means of a laser or using a wash. The same applies to an individualization of the banknote 1 by the serial number 8, which is likewise produced by an individual removal of the metallization.

The first embossed structure 14 on the inside of the first film 11 is visible when viewed from the front side 9 and completely forms the representation 3, so z. For example, both the background 4 and the image 5 and the value 7. The hologram 6 is generated by a region of the embossed structure, which has a suitable periodicity, which is higher than that of the nanostructure. Holograms are known to be formed by the grating areas with periods of 0.6 μιη to 2 μιτι. The first and second foils 11 and 12 are transparent. Preferably, they are each a plastic film. In the production of the substrate body 2, the films 11 and 12 are embossed with the embossed structures 14 and 16 and then provided with the metallization, for example by an on-steam process. Subsequently, the two films are connected to one another via the intermediate layer, which forms the dielectric 13, for example by lamination. The dielectric 13 may preferably be a polymer.

In order to take the front side 9 and the rear side 10 of the usual gloss for film, which is enhanced by the metallization of the embossed structures, it is in an embodiment, which is shown in Fig. 3, preferably, the outer surfaces of the films 11, 12 with a matting 16 to provide, for example in the form of a coating that creates a slightly scattering surface. A light scattering in a cone with an opening angle of about 5 degrees is sufficient to reduce the specular gloss of the films 11, 12 and the specular reflection on the nanostructured surface of the embossed structures 14, 15 and thus the perception for a viewer outside the glancing angle, especially in localized light sources, such as sunlight or lamplight, to increase.

FIG. 4 shows that the embossed structures can also comprise a hologram structure 18. This is shown by way of example in FIG. 4 on the basis of the first embossed structure 14. This hologram structure 18 generates, for example, the hologram 6.

The embossed structures 14, 15 can also be unstructured and / or non-metallized in one area. This area then forms a window 19 of the banknote, as FIG. 5 shows.

Banknotes with inner surfaces of the films 11, 12 structured on both sides allow a diverse design of viewing windows. FIG. 6 shows a banknote in which the embossed structures 14, 15 on the inner surfaces of the films 11, 12 in the region of the window show partial motifs 20, 21. Thus, different motifs can be seen in reflection. In transmission, the structures of the sub-motifs 20, 21 are complementary to another motif. It is particularly advantageous if the structures of the partial motifs 20, 21 have vertically asymmetrical profiles. From WO 2014/023415 Al it is known that in this way motifs are generated in reflection, which completely disappear when viewed through the window 19.

Another possible variant realized by the embossing structures an angle-dependent color filter, which also has polarizing properties. The properties and production of such transmission filters are in the DE 12011115589 AI explained in more detail. These structures are likewise suitable for the design of the window 19, for example for the partial motifs 20 and 21. In order to prevent the embossing structure 15 from appearing on the second film when viewed from the front side, it is preferable to make the intermediate layer opaque. This is shown in FIG. 7. The opacity of the material between the embossed structures 14 and 15 ensures that, when viewing the front side 9, only the embossing structure 14 contributes to the representation, when viewed from the rear side 10 only the embossed structure 15. The opacity can, for example, an opaque layer 22, preferably an opaque white or a colored adhesive layer or laminating layer, be realized. If the structural body 2 of the banknote 1 has a window 19, the opaque layer 22 is of course interrupted in this area, as FIG. 8 shows.

In a wide embodiment, illustrated in FIG. 9, the opaque layer 22 is provided with a locally varying opacity. In the embodiment of FIG. 9, this is realized by differently densely arranged holes 23. Of course, another variation of the opacity is possible, for example, by a laterally varying thinning of the opaque layer 22 or by a varying coloration. This measure makes it possible for the embossed structures 14 and 15 to interact with one another to a varying degree within the representation visible from the front side 9 and the rear side 10, ie there may be regions in which not only the embossed structure when viewed from the front side 9 14, but to a certain extent, the embossed structure 15 is visible. For example, in other areas where the opacity is greater, this is not or less the case.

A color effect can be produced by providing one or both of the films with a color layer 24. Likewise, it is possible to color the intermediate layer. Fig. 10 shows the variant with colored foil and Fig. 11 shows the variant with colored intermediate layer.

FIG. 12 shows the cross section of a so-called hybrid banknote, in which a banknote paper 25 is arranged between the first and the second film 11, 12. In the illustrated embodiment, this banknote paper additionally contains a watermark 26 above or below which the embossed structures 14, 15 form the window 19, so that the watermark is visible when viewed from the front side 9 and the rear side 10, respectively. Of course, another window can also be provided in the banknote paper 25 in order, for example, to realize the effect of FIGS. 5, 6 or 8.

Another embodiment has different transparent areas. In this case, the coated embossed structures 14, 15 are partially semi-transparent and the intervening opaque layer is partially interrupted. It is thus possible to produce regions of complete transparency, regions with a transparency which results from the transmission of the embossed structure 14 and 15, completely nontransparent regions or regions with laterally varying opacity, as shown in FIG.

The production of the value document comprises the following steps:

First, the relief structure for an original having dimensions of the document of value, such as height H and width B, is generated the banknote 1. This relief structure is generated for example by means of photolithographic processes in a photoresist. From the original structure, a stamp is then produced as a master, for example by copying the relief structure into a nickel mold by means of electroplating or into a photopolymer. With the help of this stamp now an embossing cylinder is produced, which replicates the relief structure of the original on the surface of the embossing cylinder. Typical steps for producing a stamping cylinder are the galvanic Abf ormation of a replica in nickel and drawing the structured nickel foil on a stamping cylinder. Instead of a stamping cylinder, a film web with the embossed structure can alternatively also be used for the subsequent reproduction process.

The embossing cylinder produced in this way is then used on a plastic film web in a continuous process to mold the original structure many times in UV varnish or by means of a hot embossing process into the film. The so-embossed film web contains transversely to the web direction lines in which several areas of width B and height H are adjacent. The lines are repeated along the film web. The so-embossed film web is then coated with a thin metal layer, preferably aluminum, silver, chromium, copper, gold or alloys thereof. It is also possible to apply half-metal layers, for example silicon, germanium, carbon and silicon oxide (preferably with a silicon-to-oxygen ratio of less than one). As coating processes, high-vacuum vapor deposition by means of vapor deposition or sputtering or other coating processes are suitable.

In this way, film webs for the first film 11 and the second film 12 are produced. These are then joined to their insides, ie those sides which contain the metallized embossed structures. There- in also an internal substrate, such as a banknote paper can be laminated. Subsequently, the banknotes 1 thus produced are separated by cutting. The production of demetallisierten areas or a window takes place before joining the two films. For example, it is possible to print the film webs with a wash ink at the corresponding locations where windows are to be located later, before the metallization is carried out. After metallization, the material and paint are removed by a washing process, as known to those skilled in the art. Alternatively, the metallization can be removed by irradiation with suitable laser radiation. In this way, the serial numbers 8 can be introduced into the film. The material is preferably removed on one side in a pattern corresponding to the serial number 8. The contrast is created later by the view of the inside of the backside film or on the inside substrate or dielectric.

The matting of the surface can be produced on the film web by laminating a scattering layer on the outside or by plasma melting of the film surface. The light scattering can be accomplished either by the roughness of the film surface or the roughness of the applied transparent layer. Alternatively, the laminated layer may contain fine scattering bodies, such as particles, air bubbles, etc., which form a refractive index contrast to the support medium to achieve matting Reference symbol

bill

substrate body

presentation

background

image

hologram

declaration of value

serial number

front

back

first slide

second foil

dielectric

first embossed structure

second embossed structure

structure depth

matting

subwavelength

hologram structure

window

part motive

opaque layer

holes

coat of paint

Banknote paper watermark

width

height

Claims

Patent claims

A value document, such as a banknote, a check, a credit or other payment card, a pass card or the like, which has a front (9) and a back (10), in plan view at least from the front one with the unarmed one Eye-recognizable representation (3), in plan view has certain dimensions (B, H) and a multi-layer substrate body (2), which in the plan view, the specific dimensions (B, H) and has at least a first and a second transparent film (11, 12) is constructed, which also in the plan view also have the specific dimensions (B, H) and which are interconnected by an intermediate layer (13), so that inner sides of the films (11, 12) to each other and The outer sides of the films (11, 12) facing away from the intermediate layer (13), wherein the outside of the first film (11) to the front (9) and the outside of the second film (12) to the back (10), characterized in that the of The representation (3) recognizable by the front (9) is produced by a first, at least partially metallized embossed structure (14), which is arranged on the inside of the first film (9), is formed at least in sections as a sub-wavelength structure (17) has a laterally, ie transversely to the top view direction, varying profiling and / or periodicity, and that the front side (9) forming the outside of the first film (11) and a first film (11) facing front of the intermediate layer (13) free from the Representation (3) contributing imprints are.

2. document of value according to claim 1, characterized in that the

Embossed structure (14) has a periodicity of 150 nm to 500 nm in the sections in which it is formed as a sub-wavelength structure (17) or aperiodisch with a feature size of 150 nm to 500 nm is formed.

3. value document according to one of claims 1 or 2, characterized in that the embossed structure (14) is formed at least in one area as a microstructure (17) with a period of 500 nm to 2 μιη representing a hologram.

4. document of value according to one of claims 1 to 3, characterized in that the intermediate layer (13) is at least partially opaque.

5. document of value according to claim 4, characterized in that the intermediate layer (13) has a laterally structured opacity.

6. document of value according to one of claims 1 to 5, characterized in that the value document (1) in plan view from the back (10) shows a recognizable with the unaided eye representation that the of the back (10) recognizable representation by a second, at least partially metallized embossed structure (15) is provided, which is arranged on the inside of the second film (12), at least partially formed as a sub-wavelength structure (17) having a laterally varying profiling and / or periodicity, and that the Rear side (10) forming the outer side of the second film (12) and to the second film (12) facing back (10) of the intermediate layer (13) are free from contributing to the representation imprints.

7. value document according to claim 6, characterized in that the first and second embossing structure (14, 15) in opposite areas form a window (19) in which the representation by the first embossing Structure supplemented with the further representation by the second embossed structure in review to a motif.

8. A document of value according to claim 7, characterized in that the first and second embossing structure (14, 15) in the region of the window (19) have an asymmetrical profile, and generate in reflection a motif that disappears in transparency.

9. Value document according to one of claims 6 to 8, characterized in that the intermediate layer (13) has a banknote paper (22) which has a watermark (23), wherein the embossing structures (14, 15) in the area above the watermark (23) form a window (18).

10. Document of value according to one of claims 1 to 9, characterized in that the metallization is removed in a pattern individualizing the value document, in particular a serial number (8) representing pattern.

11. document of value according to one of claims 1 to 10, characterized in that the outside of the film (11) has a matting (16) to cause a light scattering in a cone of 3 ° to 30 °.

12. document of value according to one of claims 1 to 11, characterized in that on one of the films (11) is a color layer (23), or that the intermediate layer (13) is colored.

13. document of value according to one of claims 1 to 12, characterized in that the embossed structure (14) has a rectangular profile, a sine grid, a Has intermediate shape of rectangular profile and sine grid or a moth-eye structure.