EP2590822B2 - Value document with a transparent ink-accepting layer and with an opaque ink-accepting layer - Google Patents

Description

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

Documents of value within the meaning of the present invention are, for example, banknotes, stocks, bonds, certificates, vouchers, checks, lottery tickets, high-quality entry tickets, passports, identity cards, credit cards and other flat objects of value. Such flat objects of value can also be, for example, packaging for possibly high-value products. In the context of the present invention, the term document of value also includes all preliminary stages of finished documents of value which, for example, are not yet fit for circulation, such as security paper, film or film composites, among others. Such a value document can also only be a part of a valuable object.

For design reasons or for security reasons, such documents of value are provided with security elements which, merely by virtue of their presence or design, allow the authenticity of the documents of value to be checked and at the same time serve as protection against unauthorized reproduction. A security element within the meaning of the present invention can be, for example, a window or see-through window formed by a transparent film, a security thread, a feature produced by printing such as 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 film strip, can be embodied as an optically variable security element, with an optically variable security element being understood within the meaning of the present invention as an optical element whose visual impression produced by an observer depends on the viewing direction , that is, the viewing angle of the viewer onto the optical element and possibly also from the direction of incidence of an illuminating light beam. Examples of such optically variable security elements are diffraction structures which produce a viewing angle-dependent visual impression, in particular by reconstructing optically perceptible patterns, such as embossed or volume holograms and other kinegrams, such as achromatic matt structures. Another example of such optically variable elements are optical elements that show a so-called color shift effect, such as single- or multi-layer thin-film interference layers or liquid crystal layers, each of which can be present as a continuous layer or in pigment form (so-called effect pigments such as Iriodine). Further examples are lens or micromirror structures within an optically variable security element. A common feature of such optical elements is that they are usually constructed on the basis of a polymer layer, e.g. a plastic film, or at least comprise a polymer layer as a cover or protective layer. Within the meaning of the present invention, such elements are generally referred to as security elements. In the special case that the optical element is based on a plastic film, the element can be referred to as an optical film element.

To increase security against counterfeiting, that is, to counterfeit make it more difficult to facilitate verification of authenticity or as an additional design element, it is desirable to overprint such security elements or documents of value which comprise such security elements with a further imprint in addition to an imprint that may already have been applied. However, the acceptance of ink when such security elements are overprinted is generally unsatisfactory. It is therefore known to provide printing or ink acceptance layers (hereinafter referred to as ink acceptance layers for the sake of simplicity) on such security elements. However, the ink acceptance layers suitable for such security elements are opaque at the necessary layer thicknesses or as a result of fillers or at least have an undesirable clouding effect. As a result, the visual perceptibility or machine detectability of the security element is adversely affected. For example, a good, undisturbed view through a window is then no longer possible. If the security element is an optically variable element, its optically variable effect can be impaired or prevented completely.

One countermeasure would be to provide the ink acceptance layer with a reduced layer thickness or with such a filler content that the opacity and/or the clouding effect of the ink acceptance layer is reduced in order to ensure improved perceptibility of a security element. However, this has the disadvantage that the adhesion and drying of the printing ink of the further imprint to be applied deteriorates. If good ink acceptance is required, a more or less pronounced haze above the security element must be accepted. If, on the other hand, there is a requirement to produce a clear see-through window, for example, satisfactory ink trapping of the printing ink of the additional print on the window has hitherto not been possible.

U.S. 5,387,013 discloses a value document according to the preamble of claim 1. WO 2008/031170 A1 discloses security devices with radiation curable embossed ink for security documents. U.S. 2004/0053017 A1 discloses a watermarked information carrier.

The object of the present invention is therefore to specify a security element, e.g. an optical film element, for the production of documents of value, which allows good ink acceptance, adhesion and drying of an ink of a further imprint to be applied, without causing the security element to become matt or cloudy. It is also the object of the invention to specify a document of value with such a security element.

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

The task of ink trapping layers is to ensure ink trapping, i.e. absorption of the printing ink from another imprint or certain ingredients of such printing inks, such as oils, and thus adhesion and drying of the printing ink in the further imprint. For the purposes of the present invention, the term ink acceptance layer also includes layers understood, which impart improved adhesion to a surface, in particular to a polymer, plastic or film surface. The ink-receiving layer can have one or more layers, ie it can be made up of several sub-layers, with the individual layers being homogeneous in each case. For example, a first sub-layer of the ink-receptive layer that is optionally arranged directly on the surface of the security element primarily provides increased adhesion of a further sub-layer of the ink-receptive layer on the security element, while the further sub-layer primarily ensures the ink receptivity of the printing ink of a further imprint. The first partial layer which is arranged directly on the surface of the security element and has adhesive properties is also referred to as a primer or adhesive layer.

According to the invention, the transparent ink-accepting layer is arranged above a first surface of the security element, i.e. the transparent ink-accepting layer is e.g. either applied directly to a foil or polymer or plastic layer of the security element or separated from it by one or more further, preferably transparent intermediate layers. When the security element is printed with a further imprint, the transparent ink acceptance layer advantageously forms the uppermost layer and thus ensures ink acceptance, adhesion and drying of the printing ink of the further imprint. The further imprint can be applied using an offset process, a gravure printing process or another suitable printing process. This can be a background pressure.

The use according to the invention of a transparent ink-receptive layer enables the security element to be perceived without impairment, at least before a further imprint is applied. 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 e.g. on the basis of a transparent film, the use of the transparent ink-receptive layer also enables a clear view through the window. If the security element consists of an optically variable security element, the transparent ink-accepting layer allows an unimpaired optically variable effect to be perceived.

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

Boehmite, pseudo-boehmite, zeolite, Al ₂ O ₃ or silica gel or a mixture of these substances is used as the filler. With regard to the transparency of the transparent ink-accepting layer, these fillers 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. By boehmite is meant according to " Römpp Lexikon der Chemie", 10th edition, Georg Thieme Verlag, 1996 , the rhombic crystalline metahydroxide γ-AlO(OH), which can be obtained, for example, from crystalline Al(OH) ₃ by heating for 14 days at 150°C in a sealed tube with elimination of water. Pseudo-boehmite is an agglomerate of aluminum oxide hydroxide of the formula Al ₂ O ₃ * n H ₂ O (n = 1 to 1.5).

Polyvinyl alcohol, modified polyvinyl alcohol, polyurethane dispersions, acrylate dispersions, and derivatives or mixtures thereof are used as binders. Preferably, the filler to binder ratio is between 6:1 and 30:1, said ratio being by mass. The transparent ink-accepting layer thus comprises 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 filler and binder mentioned, the ink acceptance layer preferably comprises a crosslinking agent, in particular from the class of isocyanate, aziridine, carbodiimide or glycidyl ether. Furthermore, the transparent ink-accepting layer can include other additives such as deaerators or monoprotic acids.

An ink acceptance layer constructed in this way is characterized by good adhesion to plastic layers, in particular plastic foils, and also ensures good ink acceptance of the printing ink to be applied in the further imprint and its drying and adhesion. This recipe can therefore also be used as a starting point for the development of non-transparent ink acceptance layers. For this purpose, further additives, such as pigments, are added to the formulation of the ink acceptance layer, which produce the desired property. These can be, for example, pigments such as TiO ₂ , BaSO ₄ , CaCO ₃ , silica, or polymer-based hollow sphere pigments such as "ROPAQUE" from Rohm & Haas or effect pigments that produce a pearlescent or metallic luster, interference pigments, liquid crystal pigments, thermochromic or magnetic pigments, or pigments producing phosphorescence or fluorescence or having an antistatic effect. If such an ink-receptive layer has, for example, a high opacity due to its additives, it is advisable to implement a desired base color of the security element or a substrate via the ink-receptive layer.

The adhesion of the ink acceptance layer according to the invention to plastic layers, in particular plastic films, can be improved by means of a primer layer serving as an adhesion promoter.

In a preferred embodiment of the security element according to the invention, this is designed as a see-through window or window, feature produced by printing, security thread, film strip, patch or label and the transparent ink acceptance layer is applied over the entire surface. The security element further preferably comprises a polymer layer, for example a plastic film, to which the transparent ink-accepting layer is applied. Such a security element can be produced directly on a document of value to be secured or can be prepared on a separate carrier as a transfer element. Such a separate carrier preferably has a plastic or polymer material and can be or have, for example, a foil material, in particular a transfer material. Plastics such as PET (polyethylene terephthalate), PBT (polybutylene terephthalate), PEN are used for the film material (polyethylene naphthalate), PP (polypropylene), PA (polyamide) and PE (polyethylene) into consideration. This film material can also be stretched monoaxially or biaxially.

The security element is attached to a document of value to be secured with the aid of an adhesive layer, a hot-melt adhesive preferably being used for this purpose. After the security element has been transferred to a document of value to be secured, the carrier material is optionally removed again, so that the security element remains on the document of value to be secured. The transparent ink acceptance layer serves as a separating layer or release layer.

A transparent UV lacquer is often used as a cover and protective layer on known security elements, in particular on transfer elements. In the preferred embodiment, this UV lacquer layer is either covered with the transparent ink-receptive layer or replaced by the transparent ink-receptive layer.

When the film strip or transfer element is printed with the further imprint, the transparent ink-receptive layer forms the uppermost layer of the security element, which increases the ink-receptiveness for the printing ink of the further imprint, since the transparent ink-receptive layer has improved ink-receptiveness compared to the known transparent UV lacquer.

In a preferred embodiment, the security element can be designed 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 is the case with security threads or film strips, for example so-called LEAD strips, the case is. If such a security element is designed as a transfer element with an optionally transparent film as the carrier, it is also referred to as a film element, film patch or film strip.

According to the invention, a document of value comprises a substrate and a security element according to the invention, which is arranged on the substrate of the document of value 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 acceptance layer is arranged above the common surface either over the entire area or at least in a first partial area of the common surface. The transparent ink-accepting layer can thus also be arranged in an area outside of the security element. The wording "outside the security element" means that the transparent ink-accepting layer is not arranged above the security element when the document of value is viewed in incident light.

Single-layer or multi-layer substrates can be used as the substrate of the document of value. In the case of single-ply substrates, any type of paper or paper-like material can be used, in particular cotton vellum paper. Paper can also be used which contains a certain proportion x of a polymer material in the range from 0 to 100% by weight. Furthermore, as Substrate a plastic layer, such as a plastic film, or a composite film can be used. Such a film can additionally be stretched monoaxially or biaxially. Such a stretching of the film leads, among other things, to the fact that it acquires polarizing properties that can be used as a security feature in the document of value.

A multi-layer composite can be used as the multi-layer substrate, which has, for example, a layer of paper or a paper-like material. A transparent plastic or polymer layer is laminated onto this layer, for example on both sides, as a result of which such a multilayer composite has an extremely high level of stability and durability. Security papers with plastic or polymer-coated paper layers are used to produce foil composite banknotes. Conversely, the multi-layer composite can also have a central layer made of a plastic or polymer material, which is coated on both sides with a layer made of paper or a paper-like material. A multi-layer, paper-free composite material can also be used as the multi-layer substrate 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 come to the surface of the substrate, as is the case with security threads such as window or pendulum security threads. The security element can also fill a gap in the substrate, as is the case with windows, in particular see-through windows. In the case of a composite consisting of several layers, such as a foil composite bank note, the security element can also be arranged underneath a transparent layer, e.g. a plastic foil, or embedded within the transparent layer.

A security element designed as a transfer element with a full-area transparent ink-accepting 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 implemented in such a way that it has the same or a similar ink-accepting ability as the Has paper or paper-like substrate surface of the document of value, since a document of value can thus be realized with a security element which, without making further coating steps necessary, has a high ability to accept ink over its entire surface.

The transparent ink-accepting layer can be arranged 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 acceptance layer. In this case, the transparent layer forms, for example, a cover or protective layer for the security element and the substrate. The transparent ink-receiving layer then ensures printability with the printing ink of a further imprint. The further transparent layer is preferably arranged directly on the common surface and/or the transparent ink-receiving layer is arranged directly on the further transparent layer, eg a plastic film.

According to the invention, an opaque ink-accepting layer is additionally arranged above the common surface in addition to the transparent ink-accepting layer. In a second partial area of the common surface, which lies outside of the security element, ie not above the security element when the document of value is viewed in incident light, the opaque ink-accepting layer has a first, preferably constant, 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 sub-area, the opaque ink-accepting layer has a recess, ie a layer thickness of zero or at least a layer thickness that is reduced compared to the first layer thickness. As a result, the security element is completely covered only by the transparent ink-accepting layer. The opaque ink-accepting layer is only arranged in areas outside of the security element.

Such a configuration allows an opaque ink-accepting layer to be arranged on the document of value without impairing the perceptibility of the security element, while at the same time good printability of the document of value is also ensured above the security element.

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, however, undesired glossy edges (adhesive tape effect) can occur. Such shiny edges stand in the way of a desired uniform appearance of the surface of the document of value. In a preferred embodiment, the layer thickness of the opaque ink-accepting layer within the third partial area and/or in a fourth partial area decreases stepwise or continuously, starting from the first layer thickness of the opaque ink-accepting layer in the second partial area, preferably down to zero or approximately zero. This decreasing curve preferably shows a constant gradient. The fourth sub-area of the common surface lies between the second and the third sub-area and preferably borders directly on the third sub-area and completely surrounds it. In the simplest case, the third sub-area defines the area of the security element, as a result of which the fourth sub-area defines an edge area of the security element, which lies outside of the security element and immediately surrounds it. In this case, the fourth partial area preferably has a constant width. The layer thickness of the opaque ink-accepting layer decreases to zero or approximately zero in the third and/or fourth partial area. The layer thickness of the opaque ink acceptance layer is particularly preferably zero in the entire third partial area and the layer thickness of the opaque ink acceptance layer decreases from the first layer thickness to zero in the fourth partial area, starting from the edge area to the second partial area to the edge area to the third partial area.

With such a gradual development of the layer thickness of the opaque ink-accepting layer, the edge area of the opaque ink-accepting layer can only be seen slightly and disruptive shiny edges, for example at the transition area between opaque and transparent ink-accepting layers, are avoided.

In a further preferred embodiment, the transparent ink-accepting layer is arranged within the second, third and possibly fourth partial area 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 acceptance layer is applied to the document of value with a layer thickness that remains the same. Alternatively, the transparent ink-accepting layer in the third and optionally fourth partial area can have a layer thickness that is increased compared to the second partial area in order to completely or at least partially compensate for the reduced layer thickness of the opaque ink-accepting layer in this area. The layer thickness of the transparent ink-accepting layer is particularly preferably designed such that the sum of the layer thicknesses of the transparent and opaque ink-accepting layer in the second, third and possibly fourth partial area, preferably over the entire surface of the document of value, remains the same. In this case, the layer thickness of the transparent ink-receiving layer in the third and/or fourth sub-area, starting from the second sub-area, has a profile corresponding to the opaque ink-receiving layer, increasing stepwise or continuously in the direction of the third sub-area, preferably with a constant gradient. Particularly preferably, the transparent ink-accepting layer has a constant layer thickness in the third sub-area and has a different layer thickness only in the fourth sub-area.

Such configurations of the opaque and transparent ink-accepting layer on the document of value create a completely flat common surface of the opaque and transparent ink-accepting layer.

In a further preferred configuration, the transparent ink-accepting layer is arranged only within the third and optionally fourth partial area, ie the layer thickness of the transparent ink-accepting layer in the second partial area is zero. Within the third and/or possibly fourth sub-area, the layer thickness of the transparent ink-receiving layer, starting from the layer thickness zero at the edge area to the second sub-area, again shows a stair-like or continuously increasing course in the direction of the third sub-area, preferably with a constant gradient, so 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 entire document of value, remains the same. If the layer thickness of the opaque ink-accepting layer in the third subarea is zero, then the layer thickness of the ink-accepting layer in the third subarea remains the same and is equal to the layer thickness of the ink-accepting layer in the second subarea.

Such configurations of the opaque and transparent ink-accepting layer on the document of value create a completely flat common surface of the opaque and transparent ink-accepting layer.

In a further preferred embodiment of the document of value the transparent ink receptive layer has first and second subregions, the transparent ink receptive layer having first and second configurations in the first and second subregions that are different from each other. The area in which the transparent ink-receiving layer is applied is thus divided into at least two sub-areas, which preferably border one another. The configuration in the two sub-areas is such that the two sub-areas produce an optically identical impression on an observer, at least when viewed from a predetermined viewing direction and preferably when viewed from all viewing directions, while the two sub-areas differ in one technical property. This can be, for example, the ink acceptance behavior with regard to the further imprint to be applied or the behavior when the document of value and/or the security element is embossed.

Likewise, alternatively or additionally, the opaque ink-accepting layer can have a first and a second sub-area, wherein the opaque ink-accepting layer has a first and second configuration in the first and second sub-area, which are different from one another. The area in which the opaque ink-accepting layer is applied is thus divided into at least two sub-areas, which preferably border one another. The configuration in the two sub-areas is such that the two sub-areas produce an optically identical impression on an observer, at least when viewed from a predetermined viewing direction and preferably when viewed from all viewing directions, while the two sub-areas differ in one technical property. This can be, for example, the ink acceptance behavior with regard to the further imprint to be applied or the behavior when the document of value and/or the security element is embossed.

Immediately after the application of the opaque and/or transparent ink-accepting layer, the respective two sub-areas are indistinguishable for an observer at least when viewing a predetermined viewing direction and preferably when viewing from all viewing directions for an observer. If the respective two sub-areas differ, for example, in their ink acceptance behavior with regard to the printing ink of the further imprint to be applied, then the two sub-areas are indistinguishable in the unprinted state, as described above. When the printing ink of the further printed image is applied to the two respective sub-areas of the transparent or opaque ink-receiving layer, these become distinguishable for an observer at least when viewed from a predetermined direction, preferably when viewed from all viewing directions, by creating a different visual impression for the observer, for example a different one show color brilliance. In this case, it is advantageous if the printing ink of the further printed image is applied over the entire surface of the respective two sub-areas as a background print.

Alternatively or additionally, the respective two sub-areas can also differ in their behavior towards embossing, that is to say they have mechanical stability that differs from one another, for example.

The necessary different design of the two In the case of a multi-layer structure, sub-areas of opaque and/or transparent ink-receptive layers can be achieved by a different layer structure or by different formulations for the ink-receptive layers in the respective sub-areas. For example, additional pigments can be provided in the ink-accepting layer in a sub-area, the presence of which can only be recognized when viewed in a predetermined viewing direction, as is the case, for example, with effect pigments such as interference pigments or liquid-crystal pigments, which exhibit a color-shift effect, for example. Alternatively, when using such effect pigments, the same formulations can also be used for the ink acceptance layer in both sub-areas, with the effect pigments being oriented differently in these sub-areas. Different ingredients that change the transmission behavior can also be used for the various sub-areas of an opaque ink-accepting layer, as a result of which the two sub-areas of the opaque ink-accepting layer produce an identical optical impression in reflected light, but are distinguishable from one another in transmitted light.

In a further preferred embodiment, the respective sub-areas of the opaque and/or transparent ink-receiving layer are arranged in such a way that the viewer receives recognizable information if these sub-areas can be distinguished from one another. The substructure formed by the two respective sub-areas forms, for example, a motif or a graphic or alphanumeric character.

In the case of the security element according to the invention and the document of value according to the invention, the transparent ink acceptance layer can additionally be provided with an overcoating, through which matting and/or an extension of the service life and fitness for circulation can be achieved. A paint system consisting of a lower and an upper paint layer, for example, is suitable as the paint layer WO 2004/072378 A1 is disclosed, the disclosure of which is incorporated herein by reference. The lower layer of paint can be a water-based dispersion paint 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. Water-based dispersions, preferably without a polyurethane content, eg based on acrylic styrene, are suitable as a physically drying paint layer. However, the upper lacquer layer can also contain a hybrid lacquer which contains both physically drying and radiation-curing lacquer components.

Further exemplary embodiments and advantages of the invention are described below by way of example with reference to the accompanying figures Figures 2 to 4 explained. The examples represent preferred embodiments which in no way limit the invention. The figures shown are schematic representations that do not reflect the real proportions but serve to improve the clarity of the various exemplary embodiments.

• Figur 1a
  eine Banknote mit einem Sicherheitselement in Draufsicht;
• Figur 1b
  einen Schnitt durch die Banknote aus Figur 1a;
• Figur 2a bis 2f
  Schnittansichten durch Ausführungsbeispiele;
• Figur 3a bis 3c
  Draufsichten auf verschiedene Ausgestaltungen von Teilbereichen; und
• Figur 4 eine
  Draufsicht auf ein weiteres Ausführungsbeispiel eines Wertdokumentes.

In detail, the figures show:

• Figure 1a
  a bank note with a security element in plan view;
• Figure 1b
  make a cut through the banknote Figure 1a ;
• Figure 2a to 2f
  sectional views through exemplary embodiments;
• Figure 3a to 3c
  Top views of different configurations of partial areas; and
• figure 4 one
  Top view of a further exemplary embodiment of a document of value.

In the Figures 1a and 1b a bank note with a substrate 1 is shown as a document of value. The denomination "50" is printed on the substrate 1 . In one embodiment, the substrate 1 of the document of value consists of paper or a paper-like material and has a correspondingly high ink acceptance capacity and good printability for an in Figure 1a not shown, further imprint. Furthermore, a security element 2, for example an optical film element, is arranged on the substrate 1, which is a transfer element in the embodiment shown. The security element 2 comprises an adhesive layer 3 which comprises an activatable adhesive, for example a hot-melt adhesive. The central film component 4 of the optical film element 2 is fixed on the surface of the substrate 1 with the aid of the adhesive layer 3 . In order to ensure good printability of the optical film element 2 and in particular of the central film component 4, the optical film element 2 also comprises a transparent ink-accepting layer 5. Accordingly, the resulting surface of the banknote consists of the transparent ink-accepting layer 5 in the area of the optical film element 2 and in the remaining area from the surface of the substrate 1. Correspondingly, a high ink acceptance ability and thus a good printability is created over the entire value document, ie the ink acceptance ability of the substrate is not impaired by the application of the described optical film element designed as a transfer element. This configuration does not have all the features claimed, in particular the opaque ink acceptance layer.

In Figure 2a a second, not claimed exemplary embodiment of a document of value in the form of a banknote is shown. The document of value in turn comprises a substrate 1, which can consist of paper or a paper-like material or also of plastic or a foil. The substrate is typically opaque. In the case of a plastic banknote, however, the substrate is usually a transparent film. A first optical film element in the form of a window 6 (passage window) and a second optical film element in the form of a security thread 7 are arranged in the substrate 1 . Both window 6 and security thread 7 emerge in the substrate 1, whereby the common surface of substrate 1, window 6 and security thread 7 generally consists of different materials. In order to ensure uniform ink acceptance for the further imprint to be applied, a transparent ink acceptance layer 5 can be arranged directly on this common surface. This in Figure 2a However, the exemplary embodiment illustrated is a film composite banknote in which the substrate 1, as well as the window 6 and the security thread 7, are covered by a plastic layer 8, for example a PET film. In this case, the transparent ink acceptance layer 5 is directly on the plastic layer 8 arranged. Furthermore, the in Figure 2a banknote shown have further layers, not shown, such as adhesive or primer layers, which ensure, for example, sufficient adhesion of the various layers to one another. The transparent ink acceptance layer 5 thus forms a uniform surface of the document of value and thus creates a uniform and high ability to accept ink on the entire document of value.

This in Figure 2b illustrated in section, embodiment of the invention differs from that in Figure 2a illustrated embodiment by an additional opaque ink-accepting layer 9. The transparent ink-accepting layer 5, as shown in the exemplary embodiment, can be arranged over the entire surface of the document of value or only in a first partial area above the common surface of substrate 1, window 6 and security thread 7, i.e. above the surface of the document of value, with the transparent ink acceptance layer 5 being arranged at least above the optical film elements, ie above the window 6 and the security thread 7 . The opaque ink acceptance layer 9 is not applied over the entire surface of the document of value. The surface of the value document is divided into one or more second sub-areas B, third sub-areas C and fourth sub-areas D. The second sub-areas B are completely outside the optical film elements, i.e. they do not overlap with the window 6 or security thread 7. The third sub-areas C correspond in the in Figure 2b illustrated embodiment the areas of the optical film elements, that is, they are arranged above window 6 and security thread 7. In the exemplary embodiment, the third partial regions C have the dimensions of the optical film elements, but they can alternatively also cover a larger or smaller region. The fourth sub-areas D are transitional areas between the second sub-areas B and the third sub-areas C and directly adjoin the second sub-areas B and the third sub-areas C. Since the third partial areas C correspond to the areas of the optical elements, the fourth partial areas D form an outer edge area around the optical film elements. The fourth partial areas D preferably have a constant width.

In the second partial areas, the opaque ink acceptance layer 9 is applied with a first, constant layer thickness. In the third partial areas C, the layer thickness of the opaque ink acceptance layer 9 is zero, ie no opaque ink acceptance layer 9 is applied in the third partial areas C. Thus, the optical perceptibility of the optical film elements is not impaired by the presence of the opaque ink-accepting layer 9. In the fourth sub-areas D, the layer thickness of the opaque ink acceptance layer 9 decreases towards the third sub-areas C, which, as shown in the exemplary embodiment, can be continuous or can also be stepped. This decreasing course of the layer thickness of the opaque ink-accepting layer 9 in the fourth partial areas D creates a transitional area of the opaque ink-accepting layer 9 which, for example, prevents the occurrence of so-called glossy edges and the occurrence of the so-called Tesa effect.

in the in Figure 2b illustrated embodiment is the opaque ink-accepting layer 9 above the transparent ink-accepting layer 5 arranged. However, it is also possible to arrange the transparent ink-receiving layer 5 above the opaque ink-receiving layer 9, as in Figure 2c illustrated embodiment is shown. This has the advantage that a surface of the document of value that is uniform in terms of ink acceptance is created.

in the in Figure 2c illustrated embodiment, the layer thickness of the transparent ink acceptance layer 5 remains the same on the entire document of value and thus in the second B, third C and fourth D partial areas. in the in Figure 2d illustrated embodiment, the layer thickness of the transparent ink-receiving layer 5 in the third partial areas C and fourth partial areas D is increased in comparison with the layer thickness in the second partial areas B, so that the reduced layer thickness of the opaque ink-receiving layer 9 in these areas is compensated, so that the total layer thickness of opaque 9 and transparent 5 ink acceptance layer is constant and thus results in a completely flat surface of the document of value.

in the in Figure 2e illustrated embodiment, the layer thickness of the transparent ink-accepting layer 5 in the second sub-areas B is zero and differs from zero only in the third sub-areas C and fourth sub-areas D. The transparent ink-accepting layer 5 thus fills in the gaps in the opaque ink-accepting layer 9, as a result of which a completely flat surface of the document of value is also created in this way.

In the in the Figures 2c, 2d and 2e In the exemplary embodiments illustrated, the transparent ink acceptance layer 5 is arranged above the opaque ink acceptance layer 9, ie the transparent ink acceptance layer 5 is applied as the opaque ink acceptance layer 9 in a later method step. in the in Figure 2f illustrated embodiment, the transparent ink-acceptance layer 5 is applied to the document of value in an earlier method step than the opaque ink-acceptance layer 9 , as a result of which the transparent ink-acceptance layer 5 lies below the opaque ink-acceptance layer 9 . In this case, too, it is possible to provide a completely flat surface of the document of value.

In an unillustrated variant of the in Figure 2f In the exemplary embodiment illustrated, the transparent ink acceptance layer 5 is arranged over the entire surface of the document of value and has an increased layer thickness in the third partial areas C and fourth partial areas D, such that the total layer thickness of the opaque 9 and transparent 5 ink acceptance layer remains the same.

In Figure 3a is that in the Figures 2a to 2f shown window 6 shown in plan view. It has a circular shape and the third partial area C is arranged exactly above the window 6 and is therefore itself circular. The fourth sub-area D forms a ring of constant width around the third sub-area C, with the fourth sub-area D directly adjoining the third sub-area C. The second sub-area B directly follows the fourth sub-area D. Thus, the layer thickness of the opaque ink acceptance layer 9 shows a gradual progression in the radial direction, starting from the center of the circular window 6 in an annular area, which directly adjoins the window 6 in the radial direction to the outside.

However, the third sub-area C can also form an area that deviates from the area of the optical film element, as is exemplified in Figure 3b is shown, where the third partial area C is a strip-shaped area in which the circular window 6 comes to rest completely. The fourth sub-areas D and second sub-areas B form further strip-shaped areas that directly adjoin.

Such a strip-shaped third subregion C is particularly suitable for elongate optical film elements, such as those already described in FIGS Figures 2a to 2f shown security thread 7. In the in Figure 3c illustrated embodiment, the third sub-area C is wider than the security thread 7, with the fourth sub-areas D adjoining the third sub-area C as further strip-shaped areas, and the second sub-areas B directly adjoining them.

The configuration of the third partial areas C, the fourth partial areas D and the second partial areas B can thus be adapted to the application method of the opaque and the transparent ink acceptance layer. These can be applied using common printing methods such as gravure printing, screen printing or flexographic printing, but also using coating methods in which the transparent and/or opaque ink-receiving layer is poured or sprayed onto the surface or is applied with rollers. One like in the Figures 3b and 3c The illustrated strip-shaped configuration of the third C, fourth D and second B partial areas is particularly suitable when the opaque and/or transparent ink acceptance layer is applied to the document of value with the aid of pressure rollers.

in the in figure 4 In the exemplary embodiment illustrated, a transparent ink-receiving layer 5 is arranged over an optical film element 2, which can be designed as a transfer element, and which has different configurations in the sub-areas 5a and 5b. Before the overprint with a further imprint, the sub-areas 5a and 5b cannot be recognized by an observer. However, the configurations of the transparent ink acceptance layer 5 in the subregions 5a and 5b differ in their ink acceptance behavior. As a result, the further imprint applied in the sub-areas 5a and 5b appears with different brilliance, for example. In this way, an additional substructure formed by the subregions 5a and 5b can be created in the transparent ink acceptance layer, which only becomes recognizable after overprinting with a further print. Alternatively or additionally, the configurations of the transparent ink-accepting layer in the sub-areas 5a and 5b can also differ in other properties. For example, effect pigments can be provided in the transparent ink-accepting layer 5 in one of the two sub-areas, as a result of which the sub-areas can only be distinguished when viewed from a predetermined viewing direction. Furthermore, the transparent ink acceptance layer can differ in its embossing behavior in the sub-areas 5a and 5b, as a result of which the different sub-areas 5a and 5b only become recognizable after the document of value has been embossed.

The sub-areas 5a and 5b can form a substructure that conveys information to the viewer, for example a motif or a graphic or alphanumeric symbol.

Likewise, the opaque ink-accepting layer 9 can also have a sub-area 9a in which the opaque ink-accepting layer has a configuration that results in ink-acceptance behavior that differs from the remaining area of the opaque ink-acceptance layer 9, or in a different embossing behavior. Likewise, effect pigments can also be provided only in a subregion 9a of the opaque ink-accepting layer or effect pigments that differ in their composition and/or alignment from the effect pigments in the rest of the ink-acceptance layer. In the case of the opaque ink-accepting layer, there is also the possibility of generating a transmitted-light behavior that differs from the rest of the opaque ink-accepting layer 9 by using, for example, different fillers in the subregion 9a. The sub-area 9a cannot then be seen in reflected light, but can be seen in transmitted light.

in the in Figures 2 to 4 In the exemplary embodiments shown, the invention was described using security elements designed as optical film elements, which are formed on the basis of a film. However, the present invention is not limited to optical film elements. Security elements that have a polymer layer instead of a plastic film could also be used. The security element can also be a feature produced by printing, for example a microprint.

Claims (10)

1. A document of value comprising a substrate (1) and a security element (2, 7), the security element (2, 7) comprising at least one transparent ink-receiving layer (5) disposed in a partial region above a first surface of the security element (2, 7) and being so disposed in or on the substrate that the first surface of the security element (2, 7) forms a common surface with a first surface of the substrate (1), characterized in that the transparent ink-receiving layer (5), which comprises a filler selected from the group consisting of boehmite, pseudo-boehmite, zeolite, Al₂ O₃ and silica gel, and a binder selected from the group comprising polyvinyl alcohol, modified polyvinyl alcohol, polyurethane dispersions, acrylate dispersions, and derivatives or mixtures thereof, is disposed above the common surface in a first portion of the common surface, wherein an opaque ink-receiving layer (9) is disposed above the common surface in a portion of the common surface which is not above, i.e. outside, the security element when the value document is viewed in reflected light.i.e. outside the security element (2, 7), wherein above the common surface the opaque ink-receiving layer (9) is arranged in a second partial region (B) of the common surface which, when the document of value is viewed in incident light, is not above, i.e. outside, the security element (2, 7). outside the security element (2, 7) when the document of value is viewed in incident light, has a first, constant layer thickness there and has a recess in a third partial region (C) of the common surface which lies above the security element when the document of value is viewed in incident light, the layer thickness of the opaque ink-receiving layer (9) within a fourth partial region (D) of the common surface, which lies between the second partial region (B) and the third partial region (C), starting from the first layer thickness in the second partial region (B), has a staircase-shaped or continuously decreasing course, preferably with a constant gradient, the layer thickness of the opaque ink-receiving layer (9) decreasing in the fourth partial region (D) to zero and being zero in the entire third partial region (C).
2. The value document of claim 1, wherein the binder comprises polyvinyl alcohol and preferably the filler to binder ratio is in the range of 6:1 to 30:1.
3. Value document according to claim 1 or 2, wherein the security element (2) is formed as a window, security thread, foil strip, print-generated feature, patch or label.
4. Value document according to any one of claims 1 to 3, wherein a transparent layer (8), preferably a plastic film, is arranged between the common surface and the transparent ink-receiving layer (5).
5. A document of value according to claim 1, wherein the fourth portion (D) is immediately adjacent to the second portion (B) and the third portion (C) and completely surrounds the third portion (C).
6. Value document according to one of claims 1 to 5, wherein the transparent ink-receiving layer (5) is arranged below or above the opaque ink-receiving layer (9) within the second (B), third (C) and optionally fourth (D) partial region and has a constant layer thickness there or has an increased layer thickness in the third (C) and optionally fourth (D) partial region compared with the second (B) partial region, preferably in such a way that the sum of the layer thicknesses of transparent ink-receiving layer (5) and opaque ink-receiving layer (9) in the second (B), third (C) and, if appropriate, fourth (D) partial region is constant.
7. Value document according to one of the claims 1 to 6, wherein the transparent ink-receiving layer (5) is arranged below or above the opaque ink-receiving layer (9) only within the third (C) and optionally fourth (D) partial region and preferably the layer thickness of the transparent ink-receiving layer (5), starting from a layer thickness of zero in the second partial region (B), has a staircase-like or continuously increasing course, preferably with a constant gradient, in such a way that the sum of the layer thicknesses of transparent ink-receiving layer (5) and opaque ink-receiving layer (9) in the second (B), third (C) and, if appropriate, fourth (D) subregion remains constant.
8. Value document according to one of the claims 1 to 7, wherein the transparent ink-receiving layer (5) has a first configuration in a first subregion (5a) of the transparent ink-receiving layer and a second configuration in at least one second subregion (5b) of the transparent ink-receiving layer, in such a way, that both subregions, at least when viewed from a predetermined direction, preferably when viewed from all directions, produce an optically identical impression on a viewer, wherein both subregions differ in a technical property, in particular in their ink-receiving behaviour or their embossing behaviour.
9. A document of value according to any one of claims 1 to 8, wherein the opaque ink-receiving layer (9) has a first configuration in a first sub-region (9a) of the opaque ink-receiving layer and a second configuration in at least one second sub-region of the opaque ink-receiving layer, such that both sub-regions produce an optically identical impression on a viewer at least when viewed from a predetermined direction, preferably when viewed from all directions, wherein both sub-regions differ in a technical property, in particular in their ink-receiving behaviour or their embossing behaviour.
10. A document of value according to claim 8 or 9, wherein the sub-regions (5a, 5b) of the transparent ink-receiving layer (5) and/or the sub-regions (9a) of the opaque ink-receiving layer (9) form information recognisable to an observer.

Images