EP2384901B1 - Value document with recess - Google Patents

Description

The invention relates to a substrate for the production of value documents having at least one recess, a value document comprising such a substrate, and a method for producing such a substrate.

For the purposes of the present invention, value documents are, for example, banknotes, composite banknotes, laminated film banknotes, reverse convertibles, certificates, vouchers, checks, high-quality admission tickets, passports, identity cards, credit cards and other flat valuables. Such valuables can also be packaging for possibly high-quality products. For the purposes of the present specification, the term value document also includes precursors of the named value documents which, for example, are not fit for circulation.

Such value documents typically include one or more layers made of paper or plastic. In this context, for example, in the EP 1 545 902 a security paper for the production of value documents described in which the paper layer is coated on both sides with foil. It is also known to provide recesses for various purposes in such value documents. For example, in the AU 488,652 discloses a multi-layer composite film banknote, are provided in the central layer recesses for receiving security elements such as diffraction gratings. From the EP 1 122 089 A multilayer document of value is also known in whose outer layers recesses are provided which enable the recognition of the value document via the sense of touch, which is important for persons with limited eyesight, for example.

Object of the present invention is therefore to provide a substrate for documents of value, which can be produced inexpensively, allows the creation of additional security features and thus allows increased protection against counterfeiting. It is a further object of the present invention to specify a method for producing such a substrate and a corresponding value document.

The document W003091042 discloses a security element having a substrate on which at least two metal layers are arranged, wherein the metal layers have different optical densities or transmittance.

This object is achieved by a substrate, a value document and a production method 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 substrate for the production of documents of value, comprising a first layer with a first transmittance having at least one recess in the region of the first layer has a second transmittance, which is greater than the first transmittance, wherein a rear side and / or on a front side of the substrate, an opaque layer is applied, which has a third transmittance, which is smaller than the second transmittance.

In the case of the substrate according to the first aspect, the at least one recess may in particular be filled with a material which has a transmittance greater than the first transmittance and / or the first layer on the side facing the front side of the substrate and / or the side of the substrate facing the back side may have a transparent or translucent covering layer covering at least one recess.

In the case of the substrate according to the first aspect, the first layer may in particular comprise a paper layer with vegetable and / or plastic fibers or a homogeneous plastic layer, in particular a film.

In the case of the substrate according to the first aspect, in particular on the front and back side of the substrate, at least in the region of the at least one recess, an opaque layer can be applied over the whole area.

In the case of the substrate according to the first aspect, the first layer can preferably have one or more continuous recesses, preferably grid holes or continuous recesses in the form of filigree writings, numbers, letters or patterns, and / or the layer thickness of the first layer in the region of the at least one recess take a variety of different values, and there preferably show a continuous course.

In the substrate according to the first aspect, the first layer in the region of the at least one recess may have a layer thickness which is greater than the layer thickness in the region outside the recess. In this way, the first layer may in particular form a tactile perceptible elevation in the region of the at least one recess.

In the substrate according to the first aspect, an opaque layer may be applied on the front side of the substrate which has a front-side recess in the region of the at least one recess of the first layer and / or an opaque layer may be applied on the back side of the substrate In the region of the at least one recess of the first layer has a back-side recess. In this case, the front-side recess and / or the rear-side recess can preferably be complete be arranged within the region of the at least one recess of the first layer, wherein the front and rear side recess are arranged in register with each other. In particular, it is preferred that the front-side recess and / or the rear-side recess are arranged completely within the region of the at least one recess of the first layer, wherein the front-side recess and the rear-side recess have a different size and the front-side recess within the rear side recess is arranged or the rear side recess is arranged within the front side recess.

In the substrate according to the first aspect, the at least one recess of the first layer may further be covered with a see-through security element, in particular with a foil strip, preferably on the side of the first layer, on which the see-through security element is applied Covering layer is provided and particularly preferably the see-through security element from the opposite side of the first layer is not covered.

In the substrate according to the first aspect, the at least one recess of the first layer may in particular be a continuous recess.

• Bereitstellen einer ersten Schicht mit einem ersten Transmissionsgrad,
• Schaffen zumindest einer Ausnehmung in der ersten Schicht, vorzugsweise mittels eines Lasers oder einer Stanze, derart dass die erste Schicht im Bereich der Ausnehmung einen zweiten Transmissionsgrad aufweist, welcher größer als der erste Transmissionsgrad ist, und
• Auftragen einer opaken Schicht auf eine Rückseite und/ oder eine Vorderseite des Substrats, wobei die opake Schicht einen dritten Transmissionsgrad aufweist, welcher kleiner als der zweite Transmissionsgrad ist.

A second aspect of the invention relates to a method for producing a substrate according to the first aspect, comprising the steps:

• Providing a first layer having a first transmittance,
• Providing at least one recess in the first layer, preferably by means of a laser or a punch, such that the first layer is in the range the recess has a second transmittance which is greater than the first transmittance, and
• Applying an opaque layer to a back side and / or a front side of the substrate, the opaque layer having a third transmittance smaller than the second transmittance.

A third aspect of the invention relates to a value document, in particular a composite film banknote or a composite film banknotes sheet, comprising a substrate according to the first aspect of the invention.

The invention is based on the finding that with the aid of the combination of a recess in a substrate for the production of documents of value with an opaque layer, with the choice of respectively suitable degrees of transmission, visually perceptible effects in value documents can be realized in a cost-effective manner, the security features represent for the value document.

The substrate according to the invention for the production of value documents comprises a first layer having a first transmittance, which has at least one recess, in the region of which the first layer has a second transmittance, which is greater than the first transmittance. The substrate and the first layer are preferably formed flat and has a front and a back. On the front side and / or the back side of the substrate, an opaque layer is applied, which has a third transmittance, which is smaller than the second transmittance. The opaque layer preferably has a third transmittance that is less than the second transmittance and greater or less than the first transmittance.

For the purposes of the present specification, the transmittance refers to the transmission of light, in particular to light in the visible wavelength range between 400 and 800 nm, that is to say for light as it is usually perceived by a viewer. However, depending on the application, the transmittance may also relate only to a single wavelength or to other wavelength ranges, for example to the near UV or IR wavelength range following the visible spectral range. An opaque layer has a transmittance of 0%. A transparent layer has a transmittance of 100%. A translucent layer has a transmittance greater than 0% and less than 100%. Preferably, a viewer can clearly distinguish a translucent layer from an opaque as well as from a transparent layer. Accordingly, a translucent layer has a transmittance that differs sufficiently clearly from the transmittances of an opaque and a transparent layer. Therefore, a translucent layer preferably has a transmittance of 5 to 95%, preferably 10 to 90% and particularly preferably 20 to 80%. If the transmittance relates not only to a single wavelength but to a wavelength range, for example the visible spectral range, the transmittance describes the transmittance of the various wavelengths in the wavelength range, averaged over the respective wavelength range. Preferably, the transmittance in a wavelength region assumes the same value for each wavelength of the wavelength region. The transmittance of a layer describes the ratio of transmitted light to incident light when passing through the layer, for example in the normal direction of the layer.

An opaque layer in the sense of the present specification is a layer which, when viewed in incident light, in the direction of observation behind the layer, for example, further layers, at least substantially, ideally completely concealed, so that these structures located further back from a viewer not be perceived more. In other words, the term "opaque" refers exclusively to viewing in incident light, this optical property in turn referring to the relevant wavelength or the relevant wavelength range. The relevant wavelength range is again typically the visible spectral range between 400 and 800 nm, but may alternatively or additionally also refer to the adjacent wavelength ranges in the near UV or IR range. In other words, the term "opaque" does not describe transmission properties.

The present invention is further based on the finding that an opaque layer is not necessarily intransparent, but may have a transmittance greater than 0%. The opaque layer on the front side of the substrate and / or the opaque layer on the back side of the substrate have such properties. For this purpose, the material, the layer thickness and other properties of the opaque layer are suitably selected. The opaque layer on the back and / or the front of the substrate is preferably an opaque ink receiving layer. Accordingly, the opaque layer is preferably a layer which enables the physical drying or film formation of oil-based printing inks and / or printing inks containing aqueous and / or organic solvents and / or cationic or free-radically curing inks. The opaque layer can be prepared on an aqueous basis and / or based on organic solvents. The opaque layer may be present as a single layer or formed in the form of multiple discrete layers which may differ with respect to the physical nature. The total layer thickness of the opaque layer may preferably be in a range of 2 μm to 15 μm. The opaque layer preferably contains self-crosslinking resins and / or at least two components to be crosslinked. The first component may preferably be selected from alkoxysilanes, isocyanates, diimides, aziridines and glycidic ethers. The second component may preferably be selected from polyurethanes, urethane acrylates, polyesters, polyethers, polyvinyl alcohols, maleates, acrylates and copolymers thereof. More particularly, the opaque layer may contain fillers such as silica gels, metal oxides, metal hydroxides, metal oxide hydrates, inorganic acid salts. If the layer thickness is sufficiently small, the opaque layer appears milky or cloudy in transmitted light.

The first layer of the substrate according to the invention may be a paper layer whose fibers consist of annuals or perennials, such as cotton or cellulose, or also partially or completely of a plastic such as PA (polyamide). However, the first layer can also be a homogeneous layer of a plastic or a mixture of several plastics, which is produced for example by extrusion of a film. Suitable materials include, for example, PP (polypropylene), PE (polyethylene), PET (polyethylene terephthalate), PA (polyamide), PC (polycarbonate), polyesters and similar plastics. Such films may also be stretched, such as BOPP (biaxially oriented polypropylene).

The first layer of the substrate according to the invention with the at least one recess has a first transmittance which is less than 100%. Preferably, the transmittance of the first layer is less than 10%, particularly preferably the transmittance of the first layer is 0% and the first layer is thus intransparent. Preferably, the first layer is also opaque. The first layer may be colored or colorless, for example white or black.

A recess is provided in the first layer, which advantageously represents a region in which the material of the first layer has a reduced layer thickness. In the region of the recess, this results in a second transmittance, which is greater than the first transmittance of the first layer. Preferably, the recess is produced in such a way and the layer thickness of the first layer in the region of the recess selected such that the second transmittance, that is the transmittance in the region of the recess for a viewer in transmitted light of the first transmittance, that is, the transmittance outside of the Area of the recess, noticeably different.

The recess is in the simplest case a continuous recess or a through hole in the first layer, that is, it represents a region in which the layer thickness of the first layer is reduced to zero. Such a hole can easily be made by means of a punch or a laser. However, the region of the recess can also have a layer thickness greater than zero, that is to say a layer thickness which is merely reduced in relation to the region outside the recess. Such a recess can for example also be generated by means of a laser. Alternatively, depending on the structural configuration of the first layer, it is also possible, for example, to create such a recess by means of heat input (for example by laser or heat sealing) by removing an intransparent layer.

According to a further alternative, the region of the recess may have a layer thickness which is identical or nearly identical to the layer thickness in the region outside the recess or even greater than the layer thickness in the region outside the recess. Such a recess may e.g. by structural conversion of an opaque layer, such as by exposure of a laser to a suitable opaque film. The treated by a laser region of the opaque film is transparent by structural transformation or is increased in its transparency. A film suitable for structural conversion may e.g. be formed of polyester (for example, polyester film Hostaphan® Mitsubishi Polyester Film GmbH). The treated by a laser region of the polyester film is transparent by structural transformation or is increased in its transparency. At the same time, the polyester film becomes thicker as a result of the action of the laser radiation and can be formed in this way into a tactile perceptible elevation. A change in the transmittance can also be replaced by other heat input, e.g. by heat sealing. Suitable opaque films are also fibrous plastics, nonwovens and plastic fabrics in question.

According to the invention, an opaque layer having a third transmittance, which is smaller than the second transmittance, and preferably smaller than the second transmittance and larger or smaller than the first transmittance, is applied on the front side and / or the back side of the substrate. The opaque layer is thus translucent, preferably with a high transmittance, so that the opaque layer is substantially transparent. When viewing the substrate in incident light from the side of the substrate on which the at least one opaque layer is applied, the opaque layer thus hides the underlying one First layer, so that, for example, a arranged in the direction behind the opaque layer recess in the first layer in reflected light is not perceived by a viewer. The recess is thus hidden by the opaque layer. When viewed in transmitted light, because of the translucency or transparency of the opaque layer, the area of the recess in the first layer can be recognized by a viewer because the area of the recess is secondarily distinguishable from the first degree of transmission of the first layer forming the surrounding area Transmittance has.

In a preferred embodiment of the substrate according to the invention, the at least one recess of the first layer is filled with a material which, with the same layer thickness, has a transmittance which is greater than the first transmittance of the first layer. This filler thus has a transmittance greater than 0% and is translucent or transparent. In particular, the specific transmission of the filling material is greater than the specific transmission of the material of the first layer. Thus, the recess in the first layer can be spatially filled, so that on the one hand, the recess is mechanically stabilized and on the other forms on the front and / or back of the first layer, a flat surface on which, for example, the opaque layer can be applied directly , Thus, the term "recess" in the first layer means in particular a region of reduced layer thickness of the material of the first layer, but not necessarily a spatial recess in the substrate, such as a cavity. In the simplest case, therefore, the substrate according to the invention for the production of documents of value from the first layer, to which the opaque layer is applied directly.

Alternatively or additionally, a transparent or translucent covering layer which covers the at least one recess of the first layer is preferably arranged on the front side and / or the rear side of the first layer. Preferably, this cover layer extends over the entire surface over the entire first layer and / or the entire substrate. The cover layer is preferably formed by a film, in particular a transparent film. Suitable materials include, for example, PP (polypropylene), PE (polyethylene), PET (polyethylene terephthalate), PA (polyamide), PC (polycarbonate) and similar plastics. With the aid of the cover layer, a planar surface is provided above the first layer, even if the recess in the first layer represents a spatial recess in the first layer, so that the cover layer forms a suitable planar, continuous surface for the application of the opaque layer. If the cover layer is applied to the front and back of the first layer, the result is, for example, a so-called triplex composite, which can be used for the production of banknotes. Depending on the configuration of the first layer, this results in, for example, a film / film / film triplex composite or a film / paper / film triplex composite, which is also known by the name "hybrid". The first layer thus forms the middle, inner layer in such a triplex composite. The cover film is preferably laminated to the first layer.

The number of layers or film layers in a substrate for the production of value documents is in principle arbitrary. A substrate for the production of value documents in the form of banknotes typically has a total thickness of up to 130 μm. The first layer typically has a layer thickness in the range between 10 and 100 μm, preferably in the range between 30 and 70 μm, and particularly preferably the layer thickness of the first layer is 50 μm. Includes the substrate on the front or Rear side of a cover layer, so this typically has a layer thickness in the range between 3 and 30 microns, preferably in the range between 6 and 18 microns and is particularly preferably 12 microns.

In a preferred embodiment of the substrate according to the invention, an opaque layer is applied to each of its front and back surfaces. It covers at least the area of the at least one recess of the first layer, preferably the entire front and back of the substrate over its entire surface.

This embodiment of the substrate according to the invention makes it possible to obscure the at least one recess in the first layer when viewed both from the front side and from the rear side in incident light, while the at least one recess when viewed in transmitted light both from the front and from the back can be perceived. The opaque layers arranged on the front side and the rear side can have different degrees of transmission from each other. Preferably, however, they are identical and have identical transmittances.

In this preferred embodiment, the first layer preferably has one or more continuous recesses. In the region of the one or more recesses, the layer thickness of the first layer is thus zero. The one or more recesses are formed, for example, as circular through holes whose diameter is preferably smaller than the layer thickness of the first layer. Preferably, a plurality of such holes are arranged in the form of a grid, the continuous recesses thus form grid holes. Holes that are so small in size can easily be opaque through an overlying Layer are covered. Accordingly, the requirements for the opacity of the overlying opaque layer decrease to effectively obscure the recesses in the form of such holes when viewed in incident light for a viewer. Nevertheless, such holes are clearly visible when viewed in transmitted light. If the diameter of these holes is smaller than the layer thickness of the first layer, then these holes can only be perceived in the transmitted light when viewed essentially perpendicularly, thus providing an additional security feature for the substrate according to the invention. Such grid holes, especially with small dimensions, can be easily produced by means of a laser. In this case, the arrangement of the recess, for example the grid holes, convey information to the viewer. For example, the recesses or grid holes form a motif. According to an alternative, the grid holes may not be circular through holes, but continuous recesses in the form of fine or filigree writings, numbers, letters or patterns.

Alternatively or additionally, the layer thickness of the first layer, which is reduced in the region of the at least one recess, assumes a multiplicity of different values in this region. Thus, in the region of the at least one recess regions with different degrees of transmission can be created, which is all greater than the first transmittance. Preferably, the layer thickness over the at least one recess shows a continuous course. Accordingly, the transmittance in the region of the at least one recess shows a continuous course. This makes it possible, even if the first layer consists of a homogeneous layer of plastic, to create a watermark-like feature, which is not or hardly visible when viewed in incident light, when viewed in transmitted light, the impression of a watermark creates. Also, for example, motifs can be introduced into the substrate or other information can be conveyed to a viewer.

In a further preferred embodiment of the substrate according to the invention, an opaque layer is applied on the front side and / or the back side of the substrate, which has a recess in the region of the at least one recess of the first layer. These are referred to below as the front-side recess and / or rear-side recess. In this case, the front-side recess and / or the rear-side recess overlap with the at least one recess of the first layer. If, for example, an opaque layer with a cutout is applied to the front side of the substrate, the observer can clearly see the front side cutout when viewing the front side of the substrate in reflected light. When viewed in transmitted light, the recess of the first layer can be clearly recognized, in particular with a high degree of transmission of the opaque layer applied to the front side. Thus, when viewed in reflected light and transmitted light, the observer once perceives the recess in the opaque layer and once the recess in the first layer, and thus two different windows. The recesses in the opaque layer on the front side and / or the back side of the substrate, as well as the recess in the first layer, can be positioned relative to one another in order to form additional security features. Furthermore, the first layer and the opaque layer on the front side and / or the back side of the substrate can each be provided with a print motif so that a single motif can be recognized by the viewer when viewed in reflected light and an overall motif can be recognized when viewed in transmitted light is. When viewing the front or the back of the substrate in incident light, the viewer can see that on the opaque layer of the Recognize the front or the reverse generated print motif as a single motif. When viewed in transmitted light, especially at high transmittance of the applied on the front or the back of the ink accepting layer both the print motif on the opaque layer of the front and the back produced as well as the print motif generated on the first layer can be recognized in the form of a total motive ,

In a preferred embodiment, the front-side recess and / or the rear-side recess is arranged completely within the region of the at least one recess of the first layer. If the recess of the first layer has a transmittance of 100%, a transparent window, the dimensions of which are defined by the front-side recess and / or the rear-side recess, results when viewed in incident light from the front or rear side. In this case, the size of the window, which the observer perceives when viewing the substrate from the front or back, is determined by the sectional area of the front side recess and the rear side recess. When viewed in transmitted light, however, because of the non-zero transmittance of the opaque layer on the front side and / or the back side, a viewer can clearly see the recess in the first layer, especially if the first layer outside the recess is opaque. Such a construction is also called a "triplex window". Depending on how the recesses in the opaque layer on the front and / or back of the substrate and the recess of the first layer are positioned relative to each other and thus overlap in transparency and the transmittances of the opaque layers and the first layer are selected, the result in transmitted light different areas with easily distinguishable degrees of transmission, with a high degree of design freedom for these areas. For example For example, recesses and recesses of different shapes and sizes can be combined with each other. Such a substrate structure is also referred to as a "combined window". Furthermore, the first layer and the opaque layer on the front side and / or the back side of the substrate can each be equipped with a print motif so that a single motif can be recognized by the viewer when viewed in reflected light and an overall motif can be recognized when viewed in transmitted light is. When viewing the front side or the rear side of the substrate in reflected light, the viewer can recognize the print motif generated on the opaque layer of the front side or the back side as a single motif. When viewed in transmitted light, the print motif produced on the opaque layer of the front side or the back side, as well as the print motif generated on the first layer can be recognized in the form of an overall motif, in particular with a high degree of transmission of the opaque layer applied to the front side or the back side become.

In a preferred embodiment, opaque layers with respective front and rear side recesses are provided both on the front side and on the rear side of the substrate, which are arranged in registry with each other. Thus, when viewed in reflected light and transmitted light, the viewer alternately takes two different windows, regardless of whether the viewing is from the front or the back. Alternatively, the front-side recess and the rear-side recess may have a different size, such that the front-side recess is arranged inside the rear-side recess or the rear-side recess is arranged inside the front-side recess. In particular, both the front side recess and the rear side recess can in this case be arranged completely within the region of the at least one recess of the first layer.

In a preferred embodiment, the front-side recess and / or the rear-side recess are arranged in register with the at least one recess in the first layer. Such a register-accurate arrangement of at least one recess of an opaque layer to the at least one recess in the first layer, is difficult for a counterfeiter to imitate, but easily nachumuprüfen for a viewer. Accordingly, such a register-accurate arrangement of front-side recess and / or rear-side recess to the recess in the first layer of the substrate forms a further security feature.

In a further preferred embodiment of the substrate according to the invention, the at least one recess of the first layer is covered with a see-through security element, for example a film strip, and thus closed. This can be done by laminating or heat sealing a cover. The cover film may include a security feature and be formed, for example, strip-shaped or patch-shaped. Such a construction is also called a "duplex window". Preferably, a cover layer is further provided on the side of the first layer on which the see-through security element is applied. The cover layer is preferably laminated. Similarly, the cover layer may be equipped with a security feature. Particularly preferably, the see-through security element is only laminated on one side by the cover layer. Accordingly, the see-through security element is not covered from the opposite side of the first layer and thus easily accessible.

In general, according to the desired reflected light / transmitted light effects, it is possible to provide different areas of the substrate with different opacities and transmittances.

The duplex window described above has a transparent or translucent cover layer. If transmitted light effects play no role, then this transparent or translucent covering layer can be replaced by an opaque layer, for example an opaque film. Thus, for example, there is a so-called "asymmetrical triplex composite" in which the first layer is covered on one side by an opaque covering layer and on the opposite side by a transparent or translucent covering layer. An embedded security feature as described above, for example in the form of a film strip, a patch or even a security thread, is then only visible from the side opposite the opaque cover layer through the recess in the first layer.

In general, desired opacities and transmittances can not only be achieved across the layers of the substrate, i. the first layer, the optional cover layer (s) and the opaque layer on the front and / or the back of the substrate, but also by using laminating adhesives, other opaque layers or printing inks produce.

The invention makes it possible to provide a multiplicity of variants for the design of the substrate with security features. These can be provided, for example, in the form of security threads, film strips, printed matter or the like, and covered for example by opaque or non-transparent layers. Alternatively, it can also be provided, the feature completely and / or partially from both sides to arrange visible. Thus, for example, the impression of a pendulum security thread can be generated.

A value document, for example a composite film banknote or composite film banknotes comprising such a substrate as described above, can easily be printed in the regions of the opaque layers. Accordingly, the use of an opaque layer with a recess which is in a defined spatial relationship to the recess in the first layer, for example, arranged in register to this, a correspondingly arranged imprint on the document of value can be easily realized.

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 that do not reflect the real proportions, but serve an improved clarity of the various embodiments.

Figur 1

eine Folienverbundbanknote in Draufsicht;

Figur 2

einen Schichtaufbau des in Figur 1 dargestellten Ausführungsbeispiels;

Figuren 3a und 3b

den Schichtaufbau eines zweiten Ausführungsbeispiels und eine Draufsicht darauf; und

Figuren 4 bis 7

den Schichtaufbau von weiteren Ausführungsbeispielen.

In detail, the figures show:

FIG. 1

a composite film banknote in plan view;

FIG. 2

a layer structure of in FIG. 1 illustrated embodiment;

FIGS. 3a and 3b

the layer structure of a second embodiment and a plan view thereof; and

FIGS. 4 to 7

the layer structure of further embodiments.

In FIG. 1 a composite film banknote 1 is shown, which is provided with the denomination "20". The composite film banknote 1 has a combined window 2. It comprises a recess 3 in a printed ink receiving layer 7, which is recognizable when viewed in incident light. The combined window 2 furthermore comprises a recess 4 in an opaque layer 5 which is applied behind the ink-accepting layer 7 and which is perceptible when viewed in transmitted light.

In FIG. 2 is the layer structure of a substrate to create the in FIG. 1 shown composite film banknote 1 in the area of the combined window 2 shown. The substrate is a so-called triplex film composite comprising a central, nontransparent layer 5 on which transparent films 6 are laminated on both sides with the aid of a transparent laminating adhesive. The central, nontransparent layer 5 consists in the embodiment shown of an opaque paper layer with a layer thickness of 85 microns. Alternatively, the central, nontransparent layer 5 can also consist of a BOPP or PET film with a layer thickness between 15 and 80 μm. The transparent films 6 consist in the embodiment shown of PET films with a layer thickness of 6 or 12 microns.

On the transparent films 6 opaque ink receiving layers 7 are arranged, which have an identical structure. The opaque ink-receiving layers 7 have recesses 3, which are arranged register-accurate to each other. The centrally arranged, non-transparent film 5 has a recess 4, wherein the region of the recess 3 of the opaque Ink receiving layers 7 is arranged in plan view completely within the region of the recess 4 of the non-transparent film 5 (see FIG. 1 ). When viewed in incident light, the observer perceives the recess 3 from both sides, which, since the non-transparent film 5 has a continuous recess 4 in this region, represents a transparent window in the substrate. The opaque ink receiving layers 7 have a non-zero transmittance. Therefore, the observer recognizes the recess 4 in the nontransparent layer 5 when viewing the substrate or the film composite banknote 1 in transmitted light. In the edge region of the recess 4, outside the recesses 3 of the opaque ink receiving layers 7, an area results that corresponds to the transmittances of the opaque Ink receiving layers 7 is translucent or transparent. This area usually appears milky cloudy. This results in a combined window 2, which has different dimensions when viewed in reflected light and transmitted light.

In the FIGS. 3a and 3b a second embodiment of a composite film banknote 1 is shown. It represents a variant of in the Figures 1 and 2 The second embodiment differs from the previous embodiment in that the recesses 3a and 3b of the opaque ink accepting layers 7a and 7b (which were respectively denoted in the first embodiment by the reference numerals 3 and 7) are no longer arranged in register with each other, but instead are arranged shifted to each other. The recesses 3a and 3b of the opaque ink-receiving layers 7a and 7b also extend into regions outside the recess 4 of the central, non-transparent layer 5. In FIG. 3b is a plan view of the composite film banknote 1 shown. In the region in which the recess 3a of the opaque ink accepting layer 7a, the recess 3b of the opaque ink accepting layer 7b As well as the recess 4 of the non-transparent layer 5 overlap in transparency, there is a completely transparent area 8 in the film composite banknote. 1

When viewed in incident light from the side of the opaque ink-receiving layer 7b, the recess 3b in the opaque ink-accepting layer 7b can be seen by the viewer. The completely transparent region 8, in which the recesses 3a and 3b of the two opaque ink-receiving layers 7a and 7b and the recess 4 of the non-transparent film 5 overlap, constitutes a partial region of the recess 3b. The region 10 in which only the recess 3b of the opaque ink acceptance layer 7b and the recess 4 of the opaque layer 5 overlap, represents a further subregion of the recess 3b of the opaque ink acceptance layer 7b. In this region 10, the inside of the opaque ink acceptance layer 7a can be seen by the viewer in reflected light. In the remaining part of the recess 3b of the opaque ink-receiving layer 7b, the surface of the non-transparent layer 5 facing the opaque ink-accepting layer 7b can be seen by the viewer. When viewed from the opposite side, that is, from the side of the opaque ink accepting layer 7a, a corresponding image is obtained for the viewer.

When viewed in transmitted light, the substrate or the composite film banknote 1 outside the recess 4 of the nontransparent layer 5 appears intransparent and thus dark. The area 8 appears completely transparent. The remaining regions of the recess 4 appear translucent, with the translucency resulting from the generally different degrees of transmission of the opaque ink-receiving layers 7a and 7b. In the regions 9 in which the recess 4 of the nontransparent layer 5 is covered by both opaque ink-accepting layers 7a and 7b, a result is obtained Translucency resulting from the combination of the transmittances of the two opaque ink acceptor layers 7a and 7b. In the region 10, a translucency results, corresponding to the transmittance of the opaque ink-accepting layer 7a. In the region 11, in which only the opaque ink receiving layer 7b is applied, a translucency results according to the transmittance of the opaque ink accepting layer 7b. The combined window 2 shown in this embodiment thus shows, in addition to a transparent area 8 and a non-transparent area, different areas 8, 9 and 10 with translucencies which are generally different from one another and thus brightnesses.

In FIG. 4 is a further embodiment of a layer structure of a triplex composite film shown. The recesses 3 in the applied on both sides opaque ink receiving layers 7 and the recess 4 of the non-transparent layer 5 are arranged in register with each other. This results in a transparent window, which is surrounded by an opaque in incident light and intransparent in transmitted light area. The registration of the recesses 3 and the recess 4 to each other can be easily verified by a viewer in incident light as well as in transmitted light.

In FIG. 5 another embodiment of a layer structure is shown, which realizes a so-called duplex window. It differs from the previous exemplary embodiments in that on the one hand the recess 4 of the nontransparent layer 5 is covered by a see-through security element 12 in the form of a film strip. The see-through element 12 is laminated with the adjacent transparent film 6a and thereby protected. The arranged on the opposite side transparent film 6b, however, has a recess 13 which is arranged in register with the recess 4 of the non-transparent film 5. Accordingly, the see-through security element 12 is open to this side. The see-through security element 12 is thus only laminated on one side and recognizable in reflected light and transmitted light. The see-through security element can act as in FIG. 5 represented, completely cover the recess 4 of the non-transparent film 5. Alternatively, however, it can cover the recess 4 only partially.

In FIG. 6 the layer structure of another embodiment of a triplex composite film is shown. On a nontransparent layer 5 both sides full-surface transparent films 6 are laminated, which are each provided with full-surface opaque ink-receiving layers 7. The non-transparent layer 5 is also formed over the entire surface apart from grid holes 14. The grid holes 14 represent continuous recesses in the nontransparent layer 5. The grid holes 14 can, as in FIG. 6 shown filled with a translucent or transparent filler 15. When viewed in incident light, only the opaque ink acceptance layer 7 lying in front of the viewing direction is thus visible from both sides. The underlying grid holes 14 of the non-transparent film, however, are not visible in reflected light. When viewed in transmitted light, a viewer can see the recesses in the opaque layer 5, that is, the grid holes 14, because of the non-zero transmittances of the opaque ink acceptance layers 7. This results in a hidden security feature. Assign the grid holes 14 as in FIG. 6 schematically shown a smaller width than the layer thickness of the non-transparent layer 5, the screen holes 14 can be perceived only in transmitted light at substantially vertical viewing, which is another security feature.

In FIG. 7 is a variant of in FIG. 6 shown embodiment shown. Instead of grid holes 14, the nontransparent layer 5 has recesses 4 which reduce the layer thickness of the nontransparent layer 5. In the region of the recesses 4, the layer thickness of the nontransparent layer 5 thus varies and optionally goes back to zero. The layer thickness can be as in FIG. 7 shown in the region of the recesses 16 show a continuous course. Accordingly, the transmittance of the nontransparent layer 5 in the region of the recesses 4 changes such that the nontransparent layer 5 is translucent or transparent there. When viewed in transmitted light, there is thus a profile of the transmittance over the region of the recesses 4, which is similar to that of a watermark in paper substrates. When viewed in incident light, the recesses 4 of the nontransparent layer 5 are obscured by the opaque ink receiving layers 7.

Claims (14)

1. A substrate for producing value documents (1), comprising a first layer (5) with a first transmittance, having at least one recess (4) in whose area the first layer has a second transmittance that is higher than the first transmittance, characterized in that on a back side and/ or on a front side of the substrate an opaque layer (7) is applied which has a third transmittance that is lower than the second transmittance.
2. The substrate according to claim 1, characterized in that the at least one recess (4) is filled with a material (15) which has a transmittance that is higher than the first transmittance, and/ or that the first layer (5) on the side facing the front side of the substrate and/ or on the side facing the back side of the substrate has a transparent or translucent cover layer (6) covering the at least one recess.
3. The substrate according to any of the claims 1 or 2, characterized in that the first layer (5) comprises a paper layer with plant fibers and/ or plastic fibers or a homogeneous plastic layer, in particular a foil.
4. The substrate according to any of the claims 1, 2 or 3, characterized in that respectively on the front side and back side of the substrate, at least in the area of the at least one recess (4), an opaque layer (7) is applied over the full area.
5. The substrate according to any of the claims 1 to 4, characterized in that the first layer (5) has one or several through-going recesses (4), preferably grid holes (14) or through-going recesses in the form of filigree writings, numbers, characters or patterns, and/ or that the layer thickness of the first layer in the area of the at least one recess (4) adopts a plurality of different values, and preferably shows a continuous gradation there.
6. The substrate according to any of the claims 1 to 4, characterized in that the first layer (5) in the area of the at least one recess (4) has a layer thickness that is greater than the layer thickness in the area outside of the recess.
7. The substrate according to claim 6, characterized in that the first layer (5) in the area of the at least one recess (4) forms a tactilely perceptible elevation.
8. The substrate according to any of the claims 1 to 7, characterized in that on the front side of the substrate an opaque layer (7, 7a) is applied, which, in the area of the at least one recess of the first layer (5), has a front-side gap (3, 3a) and/ or in that on the back side of the substrate an opaque layer (7, 7b) is applied, which, in the area of the at least one recess of the first layer, has a back-side gap (3, 3b).
9. The substrate according to claim 8, characterized in that the front-side gap (3, 3a) and/ or the back-side gap (3, 3b) are arranged completely within the area of the at least one recess (4) of the first layer, wherein preferably the front-side gap is arranged within the back-side gap or the back-side gap is arranged within the front-side gap.
10. The substrate according to claim 8 or 9, characterized in that the front-side gap (3, 3a) and/ or the back-side gap (3, 3b) are arranged in exact register to the at least one recess (4) of the first layer (5).
11. The substrate according to claim 8, 9 or 10, characterized in that the at least one recess (4) of the first layer (5) is covered with a see-through security element (12), in particular with a foil strip, wherein preferably on the side of the first layer, on which the see-through security element is applied, a cover layer (6a) is provided and particularly preferably the see-through security element is not covered from the opposite side of the first layer.
12. The substrate according to any of the claims 8 to 11, characterized in that the at least one recess (4) of the first layer (5) is a through-going recess.
13. A method for producing a substrate according to any of the claims 1 to 12, comprising the steps of:

    - supplying a first layer (5) with a first transmittance,

    - creating at least one recess (4) in the first layer, preferably by means of a laser or of a punch, in such a fashion that the first layer has a second transmittance in the area of the recess, the second transmittance being higher than the first transmittance; and characterized by

    - applying an opaque layer (7) on a back side and/ or a front side of the substrate,
    wherein the opaque layer has a third transmittance which is lower than the second transmittance.
14. A value document (1), in particular a foil composite banknote or a foil composite banknote sheet, comprising a substrate according to any of the claims 1 to 12.

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