EP2590822A1

EP2590822A1 - Transparent ink-accepting layer

Info

Publication number: EP2590822A1
Application number: EP11738610.2A
Authority: EP
Inventors: Markus Krombholz; Katharina Kugele; Ralf Liebler; Patrick Renner; Rudolf Seidler
Original assignee: Giesecke and Devrient GmbH
Current assignee: Giesecke and Devrient Currency Technology GmbH
Priority date: 2010-07-05
Filing date: 2011-07-01
Publication date: 2013-05-15
Anticipated expiration: 2031-07-01
Also published as: EP2590822B1; MX2013000033A; WO2012003947A1; AU2011276149B2; AU2011276149A1; DE102010026071A1; EP2590822B2

Abstract

The invention relates to a security element (2) for the production of valuable documents, comprising at least one transparent ink-accepting layer (5), which is arranged above a first surface of a substrate (1) over the entire area or in at least one sub-region. An opaque ink-accepting layer (9) is applied to a sub-region.

Description

Transparent color charting layer

The invention relates to a security element for the production of value documents as well as a value document comprising such a security element.

Value documents within the meaning of the present invention are, for example, banknotes, stocks, bonds, certificates, vouchers, checks, lottery tickets, high-quality admission tickets, passports, identity cards, credit cards and other flat valuables. Such flat valuables can be, for example, packaging for optionally high-quality products. For the purposes of the present invention, the term value document also encompasses all precursors of finished value documents which, for example, are not yet fit for circulation, such as, among others, security paper, film or film composites. Such a value document can also only be part of a valuable item.

For reasons of design or security reasons, such value documents are provided with security elements which, by virtue of their presence or their design, permit an examination of the authenticity of the value documents and at the same time serve as protection against unauthorized reproduction. A security element in the sense of the present invention can be, for example, a window or see-through window which is formed, for example, by a transparent film, a security thread, a feature produced by printing technology, for example a microprint, a film strip, a patch or a label. A security element, in particular a security element in the form of a security thread or a foil strip, can be considered optically variable In the context of the present invention, an optically variable security element is understood to be an optical element whose visual impression generated by an observer depends on the viewing direction, that is to say the viewer's viewing angle on the optical element and optionally also on the direction of incidence illumination light beam. Examples of such optically variable security elements are diffraction structures that produce a viewing angle-dependent visual impression, in particular by reconstructing optically perceivable patterns, such as emboss or volume holograms and other kinegrams, such as achromatic matte structures. Another example of such optically variable elements are optical elements that exhibit a so-called color shift effect, such as single or multi-layer thin-layer interference layers or liquid crystal layers, which can be present as a continuous layer or in pigment form (so-called effect pigments such as iriodines). Further examples are lens or micromirror structures within an optically variable security element. Such optical elements have in common that they are usually based on a polymer layer, for example a plastic film, constructed or comprise at least one polymer layer as a cover or protective layer. For the purposes of the present invention, such elements are generally referred to as security elements. In the specific case that the optical element is constructed on the basis of a plastic film, the element may be referred to as an optical film element.

To increase the security against counterfeiting, that is, to make it more difficult to imitate, to verify the authenticity or as an additional design element, it is desirable to include such security elements or value documents that comprise such security elements with a additional imprint in addition to an optionally already applied overprint printing. However, the ink acceptance when overprinting such security elements is usually unsatisfactory. It is therefore known to provide printing or ink-receiving layers (referred to below as ink-accepting layers for the sake of simplicity) on such security elements. However, the suitable for such security elements ink receiving layers are opaque at the necessary layer thicknesses or as a result of fillers or have at least an undesirable clouding effect. This adversely affects the visual perceptibility or machine detectability of the security element. For example, then a good, undisturbed viewing through a window is no longer possible. If the security element is an optically variable element, its optically variable effect can be impaired or completely prevented.

On the other hand, a measure would be to provide the ink-receiving layer with a reduced layer thickness or with a filler content such that the opacity and / or clouding effect of the ink-accepting layer is reduced in order to ensure improved perceptibility of a security element. However, this has the disadvantage that thereby deteriorates the adhesion and drying of the ink of the applied additional imprint. If the requirement for a good ink acceptance, a more or less pronounced turbidity above the security element must be accepted. If, on the other hand, there is the requirement, for example, to produce a clear inspection window, then a satisfactory ink acceptance of the printing ink of the additional imprint on the window has hitherto not been possible. The object of the present invention is therefore to specify a security element, for example an optical film element, for the production of value documents which permits good ink acceptance, adhesion and drying of a printing ink of a further print to be applied, without causing matting or clouding of the security element. It is a further object of the invention to specify a value document with such a security element.

This object is achieved by a security element and a value document having the features of the independent claims. The dependent claims relate to preferred embodiments and further developments of the invention.

A first aspect of the invention relates to a security element for the production of value documents, comprising at least one transparent ink receiving layer, which is arranged over the entire surface or in at least one subarea above a first surface of the security element.

The transparent ink accepting layer may comprise a filler preferably selected from the group consisting of boehmite, pseudoboehmite, zeolite, Al 2 O 3 and silica gel, and a binder, preferably polyvinyl alcohol. The filler to binder ratio is preferably in the range of 6: 1 to 30: 1. The security element can be designed, for example, as a window, security thread, foil strip, as a feature produced by printing technology, patch or label. A second aspect of the invention relates to a value document comprising a substrate and a security element according to the first aspect of the invention, which is arranged in or on the substrate such that the first surface of the security element forms a common surface with a first surface of the substrate transparent ink receiving layer above the common surface over the entire surface or at least in a first portion of the common surface is arranged.

In the document of value, a transparent layer, preferably a plastic film, be arranged between the common surface and the transparent ink-accepting layer.

In the document of value, above the common surface, an opaque ink accepting layer may be provided in at least a portion of the common surface which, when viewed in the incidental light above or not above, the value document, e.g. outside of the security element, be arranged.

The document of value according to the invention can be distinguished by the fact that above the common surface an opaque ink acceptance layer is arranged in at least a second subregion of the common surface, which is not above, ie outside, the security element when the value document is viewed in incident light, there a first, preferably has a constant layer thickness and in a third subregion of the common surface, which, when viewed in the reflected light, is above the security element when viewed in the value document, has a recess or a layer thickness reduced in relation to the first layer thickness. The layer thickness of the opaque ink-accepting layer within the third sub-area and / or in a fourth sub-area of the common sub-area Surface, which lies between the second and third portion, may preferably have a treppertförmig or continuously decreasing course, preferably with a constant gradient, starting from the first layer thickness in the second portion, wherein the layer thickness of the opaque ink receiving layer in the third and / or fourth portion decreases to zero or about zero, and more preferably is zero throughout the third subrange. The fourth subregion preferably directly adjoins the second subregion and the third subregion and completely surrounds the third subregion.

The transparent ink-accepting layer can preferably be arranged below or above the opaque ink-accepting layer within the second, third and possibly fourth subregions and have a constant layer thickness there or have an increased layer thickness in the third and optionally the fourth subregion compared to the second subregion, preferably such in that the sum of the layer thicknesses of the transparent ink-accepting layer and the opaque ink-accepting layer is the same in the second, third and optionally the fourth partial region. The transparent ink-accepting layer may preferably be arranged below or above the opaque ink-accepting layer only within the third and optionally the fourth sub-area and the layer thickness of the transparent ink-accepting layer may preferably be a trepan-shaped or continuously increasing course, preferably with a layer thickness of zero in the second partial area a constant gradient, such that the sum of the layer thicknesses of the transparent ink-accepting layer and the opaque ink-accepting layer is the same in the second, third and possibly fourth partial regions. The transparent ink-accepting layer may have a first embodiment in a first subregion of the transparent ink-accepting layer and a second embodiment in at least a second sub-region of the transparent ink-accepting layer, such that both subregions, at least when viewed from a predetermined direction, preferably when viewed from all directions, create an optically identical impression in a viewer, with both sub-areas differ in a technical property, in particular in their ink acceptance behavior or their embossing behavior.

The opaque ink acceptance layer may have a first configuration in a first subregion of the opaque ink acceptance layer and a second configuration in at least a second subregion of the opaque ink acceptance layer, such that both subregions, at least when viewed from a predetermined direction, preferably when viewed from all directions, create an optically identical impression in a viewer, with both sub-areas differ in a technical property, in particular in their ink acceptance behavior or their embossing behavior.

The subregions of the transparent ink accepting layer and / or the subregions of the opaque ink accepting layer may form information recognizable to a viewer. A third aspect of the invention relates to a method of manufacturing a value document, comprising:

a provision of a value-document substrate and a security element according to the first aspect of the invention, wherein the security element ment additionally has a above the transparent ink receiving layer applied security element carrier;

adhering the security element to the value-document substrate by means of an adhesive layer so that the value-document substrate is glued to the side of the security element facing away from the security-element carrier in order to thus provide a value-document security element structure; and

an optional step of peeling off the security element carrier from the valuable document security element structure, wherein the transparent ink accepting layer serves as a release layer.

The security element according to the invention, e.g. An optical film element, for the production of value documents, comprises at least one transparent ink acceptance layer, which is arranged over the entire surface or in at least a first subregion of the security element above a first surface of the security element.

Ink receiving layers have the task of ensuring the ink acceptance, that is to say the removal of the printing ink of a further imprint or of certain constituents of such printing inks, such as oils, and thus the adhesion and drying of the printing ink of the further imprint. For the purposes of the present invention, the term ink-accepting layer is also understood as meaning layers which impart improved adhesion to a surface, in particular to a polymer, plastic or film surface. The ink-accepting layer can be single-layered or multi-layered, that is to say composed of a plurality of partial layers, the individual layers each being homogeneous. For example, a first partial layer of the ink-accepting layer which is optionally arranged directly on the surface of the security element primarily imparts increased adhesion another sub-layer of Farbaiinahmeschicht on the security element, while the other sub-layer primarily ensures the ink receptivity of the ink of another imprint. In this case, the first partial layer arranged directly on the surface of the security element and having an adhesive capability is also referred to as primer or adhesive layer.

According to the invention, the transparent ink-accepting layer is arranged above a first surface of the security element, that is to say the transparent ink-accepting layer is e.g. either directly applied to a film or polymer or plastic layer of the security element or separated by one or more further, preferably transparent intermediate layers thereof. When printing the security element with a further imprint, the transparent ink receiving layer advantageously forms the uppermost layer and thus provides the ink acceptance, the adhesion and the

Drying of the printing ink of the additional printing safe. The additional imprint can be applied by means of an offset method, a gravure printing method or another suitable printing method. This can be a background pressure.

The use according to the invention of a transparent ink-accepting layer allows, at least before the application of a further imprint, an undisturbed perception of the security element. In particular, there is no impairment of perceptibility due to matting or clouding. If the security element is a simple window or see-through window, which is formed, for example, on the basis of a transparent film, the use of the transparent ink-accepting layer furthermore allows a clear view through the window. If the security element consists of an optically variable security element, thus, the transparent ink accepting layer allows a perception of undisturbed optically variable effect.

The transparent ink receiving layer according to the invention comprises at least one filler and a binder.

The filler used is preferably boehmite, pseudo-boehmite, zeolite, Al 2 O 3 or silica gel or a mixture of these substances. With regard to the transparency of the transparent ink receiving layer, these filling substances preferably have a particle size in a range from 1 nm to 1 μm, with the range from 5 nm to 200 nm being particularly preferred. The use of boehmite or pseudo-boehmite is preferred. According to "Römpp Lexikon der Chemie", 10th edition, Georg Thieme Verlag, 1996, boehmite is the rhombic crystalline metahydroxide γ-ΑΙΟ (ΟΗ), which is obtained, for example, from crystalline Al (OH) 3 by heating to 150 ° for 4 days C is available in the sealed tube with dehydration.

Pseudo-boehmite is an agglomerate of aluminum oxide hydroxide of the formula AI2O3 * n H2O (n = 1 to 1.5). As binders, for example, polyvinyl alcohol, modified polyvinyl alcohol, polyurethane dispersions, acrylate dispersions, and derivatives or mixtures thereof are used. Preferably, the filler to binder ratio is between 6: 1 and 30: 1, said ratio being based on mass. This means that the transparent ink-receiving layer has significantly more filler than binder. The filler-to-binder ratio may be, for example, 6: 1, 8: 1, 10: 1, 12: 1, 15: 1, 20: 1, 25: 1 or 30: 1, each of said ratios being a sub - or upper limit of the above range. In addition to the stated filler and binder, the ink-accepting layer preferably comprises a crosslinker, in particular from the class of isocyanate, aziridine, carbodiimide or glycidyl ether. Furthermore, the transparent ink accepting layer may comprise other additives such as deaerators or monoprotic acids.

A built-up ink receiving layer is characterized by good adhesion to plastic layers, in particular plastic films, and also ensures good ink receptivity of the applied ink of the other imprint and their drying and adhesion safely. This formulation can therefore also be used as a starting point for the development of non-transparent ink receiving layers. For this purpose, the formulation of the ink receiving layer further additives, such as pigments, are added, which produce the desired property. These may be, for example, pigments such as T1O2, BaSO ₄ , CaCO 3, silicic acids, or polymer-based hollow sphere pigments such as "ROPAQUE" from Rohm & Haas, or also effect pigments which produce a pearlescent or metallic luster, interference pigments, liquid-crystal pigments, thermochromic or magnetic pigments If such a color acceptor layer has, for example, a high opacity due to its additives, it is recommended to optionally add a desired base color of the security element or a substrate via the ink acceptor layer realize.

The adhesion of the paint receiving layer according to the invention to plastic layers, in particular plastic films, can be improved by means of a primer layer serving as adhesion promoter. In a preferred embodiment of the security element according to the invention this is designed as a see-through window or window, printing technology generated feature, security thread, film strip, patch or label and the transparent ink receiving layer is applied over the entire surface. The security element further preferably comprises a polymer layer, for example a plastic film, on which the transparent ink-accepting layer is applied. Such a security element can be generated directly on a security document to be secured or prepared on a separate carrier as a transfer element. Such a separate carrier preferably has a plastic or polymer material and can be, for example, a film material, in particular a transfer material. Plastics such as PET (polyethylene terephthalate), PBT (polybutylene terephthalate), PEN (polyethylene naphthalate), PP (polypropylene), PA (polyamide) and PE (polyethylene) are suitable for the film material. This film material may also be monoaxially or biaxially stretched.

The attachment of the security element on a value document to be secured takes place with the aid of an adhesive layer, for which purpose preferably a hot-melt adhesive is used. After transferring the security element to a value document to be secured, the carrier material is optionally removed again so that the security element remains on the security document to be secured. The transparent ink receiving layer serves as a release layer or release layer. On known security elements, in particular on transfer elements, a transparent UV coating is often used as a cover and protective layer. In the preferred embodiment, this UV lacquer layer is either coated with the transparent ink accepting layer or replaced by the transparent ink accepting layer. The transparent Farbarinahrneschicht forms when printing the film strip or transfer element with the additional imprint the top layer of the security element, which increases the ink acceptability for the ink of the further imprint, since the transparent ink receiving layer has an over the known transparent UV lacquer improved ink receptivity.

In a preferred embodiment, the security element may be formed as a patch or label and, for example, have a flat shape with comparable length dimensions in all directions or have an elongated shape, for example in the form of a strip, as in security threads or film strips, for example so-called LEAD strip, the Case is. If such a security element is designed as a transfer element with an optionally transparent film as a carrier, it is also referred to as a film element, foil patch or film strip.

In a preferred embodiment of the invention, a value document comprises a substrate and a security element according to the invention, which is arranged on the substrate of the value document in such a way that the first surface of the security element forms a common surface with a first surface of the substrate. In this case, the transparent ink-accepting layer is arranged above the common surface either over the entire surface or at least in a first subregion of the common surface. The transparent ink receiving layer can thus also be arranged in an area outside the security element. By the phrase "outside the security element" is meant that the transparent ink accepting layer is not located above the security element when viewing the value document in incident light. As a substrate of the value document one or more layers substrates can be used. In the case of single-ply substrates, any type of paper or paper-like material is suitable, in particular cotton vellum paper. It is also possible to use paper which contains a certain proportion x of a polymer material in the range from 0 to 100% by weight. Furthermore, a plastic layer, for example a plastic film, or a film composite can be used as the substrate. Such a film may additionally be monoaxially or biaxially stretched. Such a stretching of the film leads inter alia to obtaining polarizing properties which can be used as a security feature in the value document.

As the multilayered substrate, a multilayer composite comprising, for example, a layer of paper or a paper-like material can be used. On this layer, for example, a transparent plastic or polymer layer is laminated from both sides, whereby such a multilayer composite has an extremely high stability and durability. In this case, security papers with plastic or polymer-coated paper layers are used for producing film composite banknotes. Conversely, the multilayer composite may also comprise a central layer of a plastic or polymeric material, which is coated on both sides with a respective layer of paper or a paper-like material. As multilayer substrate material it is also possible to use a multi-layer, paper-free composite material.

The security element can be arranged on the surface of the substrate. However, it can also be arranged within the substrate and, for example, only partially contact the surface of the substrate, such as this is the case with security threads such as window or pendulum security threads. The security element can also fill a recess in the substrate, as is the case with windows, in particular see-through windows. In the case of a multi-layer composite, such as a laminated film banknote, the security element can also be arranged below a transparent layer, for example a plastic film, or be embedded within the transparent layer.

A security element formed as a transfer element with a full-surface transparent ink receiving layer is particularly suitable for application to a document of value whose substrate surface consists of paper or a paper-like material, in particular if the transparent ink-accepting layer is realized in that it has the same or a similar ink receptivity As the paper or paper-like substrate surface of the value document, since a value document can thus be realized with a security element which makes it necessary without further coating steps, has a high ink acceptability on its entire surface. The transparent ink accepting layer may be disposed directly on the common surface of the security element and the substrate. In a preferred embodiment, however, a further transparent layer, for example a plastic film, in particular a PET film or polyester film, is arranged between the common surface and the transparent ink-accepting layer. The transparent forms

Layer, for example, a cover or protective layer for the security element and the substrate. The transparent ink receiving layer then ensures printability with the ink of another print. Preferably, the further transparent layer is directly on the common Surface arranged and / or the transparent ink receiving layer directly on the other transparent layer, such as a plastic film arranged. In a preferred embodiment of the document of value, in addition to the transparent ink-accepting layer, an opaque ink-accepting layer is additionally arranged above the common surface. In a second subregion of the common surface, which lies outside, that is to say when the value document is not above the incident light, of the security element, the opaque ink acceptance layer has a first, preferably uniform, layer thickness. A third portion of the common surface is located above the security element and is preferably defined by the extent of the security element. In this third subregion, the opaque ink-accepting layer has a recess, that is to say a layer thickness of zero or at least a layer thickness reduced in relation to the first layer thickness. As a result, the security element is completely covered only by the transparent ink receiving layer. The opaque ink receiving layer is located only in areas outside the security element.

Such a configuration allows an arrangement of an opaque ink receiving layer on the document of value, without impairing the perceptibility of the security element, at the same time ensuring good printability of the document of value also above the security element.

However, in the edge regions of the opaque ink-accepting layer, for example where the opaque ink-accepting layer directly adjoins the transparent ink-accepting layer, it can lead to unwanted gloss edges (teats). saeffekt) come. Such gloss edges are contrary to a desired uniform appearance of the surface of the document of value. In a preferred embodiment, therefore, the layer thickness of the opaque ink-accepting layer decreases within the third partial area and / or in a fourth partial area from the first layer thickness of the opaque ink-accepting layer in the second partial area in a stepped or stepless manner, preferably down to zero or approximately zero. This decreasing course preferably shows a constant gradient. The fourth subregion of the common surface lies between the second and the third subregion and preferably directly adjoins the third subregion and surrounds it completely. In the simplest case, the third subregion defines the region of the security element, whereby the fourth subregion defines an edge region of the security element which lies outside the security element and directly surrounds it. In this case, the fourth subregion preferably has a constant width. The layer thickness of the opaque ink-accepting layer decreases to zero or about zero in the third and / or fourth partial region. Particularly preferably, the layer thickness of the opaque ink-accepting layer is zero over the entire third subregion and the layer thickness of the opaque ink-accepting layer decreases to zero in the fourth subregion from the edge region to the second subregion up to the edge region to the third subregion from the first layer thickness.

As a result of such a gradual course of the layer thickness of the opaque ink-accepting layer, the edge region of the opaque ink-accepting layer can only be discerned slightly, and disruptive gloss edges, for example at the transition region between opaque and transparent ink-accepting layer, are avoided. In a further preferred embodiment, the transparent ink-accepting layer is arranged within the second, third and optionally fourth subarea below or above the opaque ink-accepting layer, has a constant layer thickness there and is preferably formed as a coherent layer. In the simplest case, the transparent ink-receiving layer with the same thickness is applied to the document of value. Alternatively, the transparent ink-accepting layer in the third and optionally the fourth partial region may have a higher layer thickness than the second partial region in order to completely or at least partially compensate for the reduced layer thickness of the opaque ink-accepting layer in this region. Particularly preferably, the layer thickness of the transparent ink-accepting layer is designed such that the sum of the layer thicknesses of transparent and opaque ink-accepting layer in the second, third and optionally fourth partial area, preferably over the entire surface of the value document, is constant. In this case, the layer thickness of the transparent ink-accepting layer in the third and / or fourth partial area, starting from the second partial area, has a course corresponding to the opaque ink-accepting layer, stepwise or continuously increasing in the direction of the third partial area, preferably with a constant gradient. Particularly preferably, the transparent ink-accepting layer has a constant layer thickness in the third partial region and exhibits a different layer thickness only in the fourth partial region. Such embodiments of opaque and transparent ink receiving layer on the value document a completely flat common surface of opaque and transparent ink receiving layer is created. In a further preferred refinement, the transparent ink-accepting layer is arranged only within the third and, if appropriate, the fourth partial region, that is to say the layer thickness of the transparent ink-accepting layer in the second partial region is zero. Within the third and / or possibly fourth subarea, the layer thickness of the transparent ink accepting layer, starting from the layer thickness zero at the edge region to the second subregion, again exhibits a stepwise or continuously increasing course in the direction of the third subregion, preferably with a constant gradient, such that the sum of the layer - Thick of transparent and opaque ink receiving layer in the second, third and optionally fourth portion, preferably over the entire surface on the entire document of value, is the same. If the layer thickness of the opaque ink-accepting layer is zero in the third subregion, then the layer thickness of the ink-accepting layer in the third sub-region is the same and equal to the layer thickness of the ink-accepting layer in the second subregion.

Such embodiments of opaque and transparent ink receiving layer on the document of value, a completely flat common surface of opaque and transparent ink receiving layer is created.

In a further preferred embodiment of the document of value, the transparent ink-accepting layer has a first and a second sub-area, wherein the transparent ink-accepting layer in the first and second sub-areas has a first and second configuration which are different from one another. The region in which the transparent ink-accepting layer is applied is thus subdivided into at least two subregions, which preferably adjoin one another. The design in the Both subregions are in such a way that the two subregions, at least when viewed from a predetermined viewing direction and preferably when viewing from all viewing directions, produce an optically identical impression in a viewer, while both subregions differ in a technical property. This can be, for example, the ink acceptance behavior with regard to the additional imprint to be applied or the behavior when embossing the value document and / or the security element. Likewise, alternatively or additionally, the opaque ink accepting layer may include first and second subregions, wherein the opaque ink accepting layer in the first and second subregions has first and second configurations different from each other. The region in which the opaque ink-accepting layer is applied is thus subdivided into at least two subregions, which preferably adjoin one another. The

Embodiment in the two sub-areas is such that the two sub-areas at least when viewed from a predetermined viewing direction and preferably when viewed from all viewing directions produce a visually equal impression in a viewer, while both sub-areas differ in a technical property. This can be, for example, the ink acceptance behavior with regard to the additional imprint to be applied or the behavior when embossing the value document and / or the security element. Immediately after applying the opaque and / or transparent

Ink acceptance layer are the two sub-areas for a viewer at least when viewing a predetermined viewing direction and preferably when viewed from all viewing directions indistinguishable to a viewer. Are the two differences between For example, in their ink acceptance behavior with respect to the printing ink of the additional imprint to be applied, the two subregions in the unprinted state, as described above, are indistinguishable. When the printing ink of the further printed image is applied to the respective two subregions of transparent or opaque ink-accepting layer, they are distinguishable to a viewer, at least when viewed from a predetermined direction, preferably from all viewing directions, producing a different visual impression on the viewer, for example a different one - show color brilliance. It is advantageous if the printing ink of the further printed image is applied over the entire surface of the respective two subregions as background printing.

Alternatively or additionally, the respective two subregions can also differ in their behavior with respect to an embossment, that is to say they have, for example, a different mechanical stability from each other.

The necessary different embodiment of each of the two sub-areas of opaque and / or transparent ink-accepting layer can be achieved in the case of a multilayer structure by a different layer structure or by different formulations for the ink receiving layers in the respective sub-areas. For example, in a sub-area, additional pigments may be provided in the ink-accepting layer, the presence of which is detectable only when viewed in a predetermined viewing direction, as is the case with effect pigments such as interference pigments or liquid crystal pigments, for example, showing a color-shift effect. Alternatively, when using such effect pigments, the same formulations for the Ink accepting layer can be used in both sub-areas, wherein the orientation of the effect pigments in these sub-areas are formed differently from each other. For the different subregions of an opaque ink-accepting layer, it is also possible to use different constituents which change the transmission behavior, with the result that the two subareas of the opaque ink-accepting layer produce an identical visual impression in reflected light, but can be distinguished from one another in transmitted light. In a further preferred embodiment, the respective subregions of opaque and / or transparent ink-accepting layer are arranged in such a way that recognizable information results for the observer when these subregions are distinguishable from one another. The substructure formed by the two respective subregions forms, for example, a motif or a graphic or alphanumeric character.

In the case of the security element according to the invention and the value document according to the invention, the transparent ink receiving layer can additionally be provided with an overcoat, by means of which matting and / or an extension of the service life and circulation capability can be achieved. As a lacquer layer is suitable, for. a paint system consisting of a lower and an upper lacquer layer, which is e.g. in the WO

2004/072378 Al, the disclosure of which is incorporated herein by reference. The lower lacquer layer may be a water-based dispersion lacquer layer based, for example, on water-based dispersions of aliphatic polyester-polyurethanes or acrylic-styrene-polyurethanes. The upper lacquer layer is preferably a radiation-curing and / or physically drying lacquer layer. As a physically drying lacquer layer are water-based dispersions, preferably without Polyurethane content, eg acrylic-styrene-based. However, the upper lacquer layer can also contain a hybrid lacquer which contains both physically drying and a radiation-curing lacquer component. Further exemplary embodiments and advantages of the invention are explained below by way of example with reference to the accompanying figures. The examples represent preferred embodiments which in no way limit the invention. The figures shown are schematic representations which do not reflect the real proportions but serve to improve the clarity of the various embodiments.

In detail, the figures show:

Figure la a banknote with a security element in plan view;

Figure lb is a section through the banknote of Figure la;

FIGS. 2a to 2f

Sectional views through further embodiments;

FIGS. 3a to 3c

Top views of various embodiments of sub-areas; and FIG. 4 shows a plan view of a further exemplary embodiment of a value document.

In FIGS. 1 a and 1 b, a banknote having a substrate 1 is shown as a value document. The denomination "50" is recorded on the substrate 1. prints. The substrate 1 of the document of value consists in the embodiment of a paper or a paper-like material and has a correspondingly high ink receptivity and good printability for an applied, not shown in Figure la, further imprint. On the substrate 1, a security element 2, for example, an optical film element, further arranged, which is a transfer element in the illustrated embodiment. The security element 2 comprises an adhesive layer 3, which comprises an activatable adhesive, for example a hot melt adhesive. With the aid of the adhesive layer 3, the central film constituent 4 of the optical film element 2 is fixed on the surface of the substrate 1. In order to ensure good printability of the optical film element 2 and in particular the central film component 4, the optical film element 2 further comprises a transparent ink accepting layer 5. Accordingly, the resulting surface of the banknote in the region of the optical film element 2 from the transparent ink accepting layer 5 and Accordingly, a high ink receptivity and thus a good printability is created on the entire document of value, that is, the ink receptivity of the substrate is not affected by the application of the beschranbe- nen, designed as a transfer element optical film element.

FIG. 2 a shows a second exemplary embodiment of a value document in the form of a banknote. The value document in turn comprises a substrate 1, which may consist of paper or a paper-like material or else of plastic or a film. The substrate is typically opaque. In the case of a plastic banknote, however, the substrate is usually a transparent film. In the substrate 1 is a first optical film element in the form of a window 6 (passage window) and a second optical film element arranged in the form of a security thread 7. Both window 6 and security thread 7 occur in the substrate 1 to the surface, whereby the common surface of substrate 1, window 6 and security thread 7 is generally made of different materials. In order to ensure uniform ink receptivity for the further imprint to be applied, a transparent ink receiving layer 5 can be arranged directly on this common surface. The exemplary embodiment illustrated in FIG. 2a, however, is a foil composite banknote in which substrate 1, as well as window 6 and security thread 7, are coated by a plastic layer 8, for example a PET film. The transparent ink-receiving layer 5 is arranged directly on the plastic layer 8 in this case. Furthermore, the banknote shown in FIG. 2a can have further layers (not shown), such as adhesive or primer layers, which ensure, for example, adequate adhesion of the various layers to one another. The transparent ink receiving layer 5 thus forms a uniform surface of the document of value and thus provides a uniform and high ink receptivity to the entire document of value. The further exemplary embodiment shown in section in FIG. 2b differs from the embodiment illustrated in FIG. 2a by an additional opaque ink receiving layer 9. The transparent ink receiving layer 5 can, as shown in the exemplary embodiment, be arranged over the complete surface on the document of value or only in a first part - Rich above the common surface of substrate 1, window 6 and security thread 7, that is above the surface of the document of value, wherein the transparent ink accepting layer 5 at least above the optical film elements, that is above window 6 and security thread 7 is arranged. The opaque ink receiving layer 9 is not over the entire surface 9

- 26 - applied to the surface of the document of value. The surface of the value document is subdivided into one or more second subareas B, third subareas C and fourth subareas D. The second subareas B are completely outside the optical film elements, ie they do not overlap with window 6 or security thread 7. The third Subregions C in the exemplary embodiment illustrated in FIG. 2b correspond to the regions of the optical film elements, that is to say they are arranged above window 6 and security thread 7. The third portions C have in the embodiment, the dimensions of the optical film elements, but they can alternatively cover a larger or a smaller area. The fourth partial regions D are transition regions between the second partial regions B and the third partial regions C and adjoin the second partial regions B and the third partial regions C directly. Since the third subregions C correspond to the regions of the optical elements, the fourth subregions D form an outer edge region around the optical film elements. The fourth partial regions D preferably have a constant width.

In the second partial areas, the opaque ink receiving layer 9 is applied with a first, uniform layer thickness. In the third subregions C, the layer thickness of the opaque ink-accepting layer 9 is zero, that is, in the third subregions C, no opaque ink-accepting layer 9 is applied. Thus, the optical perceptibility of the optical film elements is not affected by the presence of the opaque ink receiving layer 9. In the fourth subregions D, the layer thickness of the opaque ink-accepting layer 9 shows a course decreasing towards the third subregions C, which, as shown in the exemplary embodiment, can be stepless or can also be configured as a staircase. Due to this decreasing course of the layer thickness of the opaque ink receiving layer 9 in FIG The fourth subregions D are provided with a transition region of the opaque ink-accepting layer 9 which prevents, for example, the occurrence of so-called glossy edges and the occurrence of the so-called tesa effect. In the exemplary embodiment illustrated in FIG. 2b, the opaque ink-accepting layer 9 is arranged above the transparent ink-accepting layer 5. However, it is also possible to arrange the transparent ink-receiving layer 5 above the opaque ink-receiving layer 9, as shown in the embodiment shown in Figure 2c. This has the advantage that it creates a uniform surface of the value document with regard to the ink acceptability.

In the exemplary embodiment illustrated in FIG. 2c, the layer thickness of the transparent ink-accepting layer 5 remains constant on the entire value document and thus in the second B, third C and fourth D sub-regions. In the exemplary embodiment illustrated in FIG. 2d, the layer thickness of the transparent ink acceptance layer 5 in the third subregions C and fourth subregions D is increased in comparison with the layer thickness in the second subregions B, so that the layer thickness of the opaque ink acceptance layer 9 reduced in these regions is compensated, so that the total layer thickness of opaque 9 and transparent 5 ink receiving layer is the same and thus results in a completely flat surface of the value document. In the exemplary embodiment illustrated in FIG. 2e, the layer thickness of the transparent ink-accepting layer 5 in the second partial regions B is zero and is different from zero only in the third partial regions C and fourth partial regions D. The transparent ink-receiving layer 5 thus fills the recesses in the opaque ink-receiving layer 9, which also causes this way, a completely flat surface of the value document is created.

In the exemplary embodiments illustrated in FIGS. 2c, 2d and 2e, the transparent ink-accepting layer 5 is arranged above the opaque ink-accepting layer 9, that is to say the transparent ink-accepting layer 5 is applied as the opaque ink-accepting layer 9 in a later method step. In the embodiment illustrated in FIG. 2f, however, the transparent ink-receiving layer 5 is applied to the document of value as the opaque ink-accepting layer 9 in an earlier process step, whereby the transparent ink-accepting layer 5 lies beneath the opaque ink-accepting layer 9. Also in this case, it is possible to provide a completely flat surface of the document of value. In a variant of the embodiment shown in FIG. 2f, not shown, the transparent ink-receiving layer 5 is arranged over the entire surface on the document of value and has an increased layer thickness in the third subregions C and fourth subregions D, so that in turn the total layer thickness of opaque 9 and transparent 5 layer is consistent.

In Figure 3a, the window 6 shown in Figures 2a to 2f is shown in plan view. It is of circular design and the third subregion C is arranged exactly above the window 6 and thus forms a circle itself. The fourth subregion D forms a ring of constant width around the third subregion C, wherein the fourth subregion D adjoins the third subregion C directly. The second subregion B adjoins the fourth subregion D directly. Thus, the layer thickness of the opaque ink-receiving layer 9 shows a gradual course in the radial direction starting from the center of the circular window 6 in an annular region which adjoins the window 6 directly in the radial direction outwards. However, the third subregion C may also form a region deviating from the region of the optical film element, as shown by way of example in FIG. 3b, where the third subregion C is a strip-shaped region in which the circular window 6 comes to lie completely. The fourth subregions D and second subregions B form further strip-shaped regions which adjoin one another directly.

Such a strip-shaped third subarea C is particularly suitable for elongated optical film elements, such as the security thread 7 already shown in FIGS. 2a to 2f. In the exemplary embodiment illustrated in FIG. 3c, the third subarea C is wider than the security thread 7, wherein in turn connect the fourth partial regions D as further strip-shaped regions to the third partial region C, and immediately thereafter join the second partial regions B. Thus, the configuration of the third subregions C, the fourth subregions D and the second subregions B can be adapted to the application method of the opaque and the transparent ink accepting layer. These can be applied by conventional printing methods such as gravure printing, screen printing or flexographic printing but also by coating methods in which the transparent and / or opaque ink receiving layer is poured or sprayed onto the surface or applied with rollers. A strip-like configuration of the third C, fourth D and second B subregions as illustrated in FIGS. 3b and 3c is particularly suitable. especially when the opaque and / or transparent ink receiving layer is applied by means of pressure rollers on the value document.

In the exemplary embodiment shown in FIG. 4, a transparent ink receiving layer 5 is arranged above an optical film element 2, which may be designed as a transfer element, which has different configurations in the subregions 5a and 5b. Before the overprint with a further imprint, the subregions 5a and 5b are not recognizable to a viewer. However, the configurations of the transparent ink accepting layer 5 in the subregions 5a and 5b differ in their ink acceptance performance. As a result, the applied additional imprint appears in the subregions 5a and 5b, for example, with different brilliance. Thus, an additional, formed by the sub-regions 5a and 5b substructure in the transparent ink-receiving layer can be created, which is recognizable only after overprinting with a further imprint. Alternatively or additionally, the configurations of the transparent ink-accepting layer in the subregions 5a and 5b may also differ in other properties. For example, effect pigments may be provided in the transparent ink-accepting layer 5 in one of the two subregions, whereby the subregions can be distinguished only when viewed from a predetermined viewing direction. Furthermore, the transparent ink acceptance layer in the subregions 5a and 5b may differ in their embossing behavior, as a result of which the various subregions 5a and 5b become recognizable only after embossing the value document.

The subregions 5a and 5b can form a substructure which conveys information to the viewer, for example a motif or a graphic or alphanumeric symbol. Likewise, the opaque ink-receiving layer 9 may also have a subregions 9a in which the opaque ink-receiving layer has a configuration which results in a different color acceptance behavior from the remaining region of the opaque ink-accepting layer 9, or in a different embossing behavior. Likewise, only in a subregion 9a of the opaque ink-accepting layer can effect pigments be provided or effect pigments which differ in their composition and / or orientation from the effect pigments in the remaining ink-accepting layer. In the case of the opaque ink receiving layer, it is also possible by using, for example, different fillers in the lower region 9a to produce a transmitted light behavior which differs from the remaining opaque ink acceptance layer 9. The sub-area 9a is then not visible in reflected light, but perceptible in transmitted light.

In the embodiments shown in Figures 1 to 4, the invention has been described with reference to formed as optical film elements security elements, which are formed on the basis of a film. However, the present invention is not limited to optical film elements. It could just as security elements are used, which have a polymer film instead of a plastic film. Likewise, the security element may be e.g. around a typographically generated feature, e.g. a micro-pressure, act.

Claims

Patent claims

1. security element (2) for the production of documents of value, comprising at least one transparent ink receiving layer (5), which is arranged over the entire surface or in at least a partial area above a first surface of the security element.

2. The security element (2) according to claim 1, characterized in that the transparent ink receiving layer comprises a filler which is preferably selected from the group consisting of boehmite, pseudo-boehmite, zeolite, AI2O3 and silica gel, and a binder, preferably polyvinyl alcohol and preferably the filler to binder ratio ranges from 6: 1 to 30: 1.

3. Security element (2) according to claim 1 or 2, characterized in that the security element is designed as a window, security thread, film strip, printing technology generated feature, patch or label.

4. value document comprising a substrate (1) and a security element (2) according to one of claims 1 to 3, which is arranged in or on the substrate such that the first surface of the security element forms a common surface with a first surface of the substrate, wherein the transparent ink-accepting layer (5) is arranged above the common surface over the entire surface or at least in a first partial region of the common surface.

5. document of value according to claim 4, characterized in that a transparent layer (8), preferably a plastic film, between the common surface and the transparent ink receiving layer (5) is arranged.

6. A document of value according to claim 4 or 5, characterized in that above the common surface an opaque ink receiving layer (9) in at least a portion of the common surface, which when viewing the value document in incident light above or not above, i. outside, the security element (2) is located.

7. A document of value according to claim 4, 5 or 6, characterized in that above the common surface an opaque ink acceptance layer (9) in at least a second portion (B) of the common surface, which when viewing the value document in incident light is not above, i. outside, the security element (2) is located, there has a first, preferably constant layer thickness and in a third portion (C) of the common surface, which is in viewing light of the value document in incident light above the security element, a recess or opposite reduced the first layer thickness

Has layer thickness.

8. The document of value according to claim 7, wherein the layer thickness of the opaque ink accepting layer (9) within the third partial area (C) and / or in a fourth partial area (D) of the common surface, which lies between the second (B) and third partial area, starting from the first

Layer thickness in the second portion, a stepped or continuously decreasing course, preferably with a constant gradient, wherein the layer thickness of the opaque ink accepting layer in the third and / or fourth portion decreases to zero or about zero, and more preferably in the entire third portion is zero ,

9. value document according to claim 7 or 8, characterized in that the fourth portion (D) directly adjacent to the second portion (B) and the third portion (C) and completely surrounds the third portion.

10. Document of value according to one of claims 7 to 9, characterized in that the transparent Farbartnahmeschicht (5) below or above the opaque ink receiving layer (9) within the second (B), third (C) and optionally fourth (D) portion is arranged and there has a constant layer thickness or in the third and possibly the fourth subregion has an increased compared to the second sub-layer thickness, preferably such that the sum of the layer thicknesses of transparent ink receiving layer and opaque ink receiving layer in the second, third and possibly fourth sub-area is the same ,

11. A document of value according to any one of claims 7 to 9, characterized in that the transparent ink receiving layer (5) below or above the opaque ink receiving layer (9) only within the third (C) and optionally fourth (D) portion is arranged and preferably the layer thickness of the transparent ink-accepting layer, starting from a layer thickness of zero in the second partial region (B), has a step-shaped or continuously increasing course, preferably with a constant gradient, such that the sum of the layer thicknesses of transparent ink-accepting layer and opaque ink-accepting layer in the second, third and possibly fourth sub-area is the same.

12. document of value according to one of claims 4 to 11, characterized in that the transparent ink receiving layer (5) in a first Un- In the lower part (5a) of the transparent ink-accepting layer, a first embodiment and in at least a second sub-region (5b) of the transparent ink-accepting layer has a second configuration, such that both sub-regions, at least when viewed from a predetermined direction, preferably when viewed from all directions produce optically identical impression in a viewer, with both sub-areas in a technical property, in particular in their ink acceptance behavior or their embossing behavior differ.

13. Document of value according to one of claims 7 to 12, characterized in that the opaque ink receiving layer (9) in a first subregion (9a) of the opaque ink receiving layer has a first configuration and in at least a second subregion of the opaque ink receiving layer has a second configuration such that Both sub-areas at least when viewed from a predetermined direction, preferably when viewed from all directions, create an optically identical impression in a viewer, both sub-areas differ in a technical property, in particular in their ink acceptance behavior or their embossing behavior.

14. Document of value according to claim 12 or 13, characterized in that the subregions (5a, 5b) of the transparent ink accepting layer (5) and / or the subregions (9a) of the opaque ink accepting layer (9) form a recognizable information for a viewer.

15. A method of producing a value document, comprising:

providing a valuable document substrate and a security element according to one of claims 1 to 3, wherein the security element additionally has a security element carrier applied above the transparent ink accepting layer;