EP3847038A1

EP3847038A1 - Security element

Info

Publication number: EP3847038A1
Application number: EP19769381.5A
Authority: EP
Inventors: Wolfgang Deckenbach; Thomas Giering; Stephan Steinlein; Johann Kecht; Thomas Happ
Original assignee: Giesecke and Devrient Currency Technology GmbH
Current assignee: Giesecke and Devrient Currency Technology GmbH
Priority date: 2018-09-07
Filing date: 2019-09-06
Publication date: 2021-07-14
Anticipated expiration: 2039-09-06
Also published as: DE102018007096A1; WO2020048640A1; US20210213771A1; EP3847038B1

Abstract

The invention relates to a security transfer element (20), a valuable document, comprising a security element layer composite (200), a method for testing a valuable document, a test unit, a valuable document processing device, and a system comprising test unit and/or valuable document processing device and security transfer element and/or valuable document. The security transfer element comprises a security element layer composite having a functional layer, wherein the functional layer manifests an optically variable effect for an observer. On the opposite side of the functional layer with respect to the observer, the security element layer composite comprises at least one luminescent substance. The luminescent substance has a primary emission wavelength in a wavelength range of between 700 nm and 2100 nm and is excitable by an excitation radiation in the wavelength range of between 400 nm and 2100 nm. Furthermore, the functional layer is embodied such that it is opaque to the emission radiation of the luminescent substance. The security transfer element comprises a carrier film (21). The security element layer composite is arranged on the carrier film in a releasable manner. The security element layer composite 200 comprises a functional layer (210) and an adhesive layer (220). The functional layer comprises an embossing lacquer (211) having an embossing structure (212). The embossing lacquer is coated with a metallization (213). The adhesive layer comprises a plurality of luminescent substances. The functional layer can also comprise transparent high refractive index layers, thin-film elements having a color tilt effect, or layers composed of liquid-crystalline material.

Description

Security element

The present invention relates to a safety-transfer element, a value document with a safety-element-layer composite, a method for testing a document of value, a test unit, a Wertdokumentbearbei- processing device and a system of checking unit and / or Wertdoku- management processing _V orrichtung and security transfer element and / or

Value document.

Value documents are to be understood as sheet-shaped objects which, for example, represent a monetary value or an authorization and should therefore not be able to be produced arbitrarily by unauthorized persons. They therefore have features which are not easy to manufacture, in particular not easy to copy, the presence of which is an indication of the authenticity, ie the manufacture by an authorized body, or the integrity. These features are often referred to as security elements. Important examples of such documents of value are chip cards, coupons, vouchers, checks and in particular bank notes, stocks, tokens, ID cards, credit cards and passports as well as labels, seals, packaging or other objects for identification or security. The security elements enable the authenticity of the value document to be checked and additionally serve as protection against or identification of an unauthorized copy. The security elements can be provided both individually and in the form of transfer belts. The transfer belts have a multiplicity of security elements designed as a security transfer element. These security transfer elements include the security elements, which are generally constructed in multiple layers and are each referred to as a security element layer composite. The security transfer member onto a transfer _S, the safety elements prepared chicht for forming, wherein the order of layers of the respective gene security element layer composite is reverse to the order as it should be later on the object to be protected. When the security transfer element is transferred to the object to be protected, the transfer layer is usually removed, for example pulled off. On the transfer _S chicht opposite side of the safety transformer ferelements, the security element layer composite an adhesive layer on, for example, a heat-seal adhesive, which is activated to the value document in transmission (application-on) of the security element layer composite or, for example, melts and the respective Sicherheitselementschichtver- bunde with the Value document glued. For this purpose, the transfer belt is placed with the heat seal adhesive layer on the valuable document and beispiels- as reasonable by the heated Transfer _S temple or a transfer roller presses and the outline shape of the heated transfer die on the subject of transfer. Transfer elements, transfer ribbons and the transfer of transfer elements to target substrates are described, for example, in EP 0420 261 B1 and WO 2005/108108 A2. The security transfer elements can be embossed and transferred according to a shape from the transfer belt, for example with the aid of the transfer stamp. In place of a molding by the transfer stamp when transmitting _V organg individual security transfer elements can be prefabricated already on the transfer belt in the desired outline shape.

The document EP 1 880 864 B1 discloses a security transfer element. The security transfer element has a carrier film. An adhesive layer is arranged on both sides of the carrier film, at least one adhesive layer being structured so that the security transfer element gives a viewer an optically variable impression when the viewing angle changes. In addition, at least one of the adhesive layers comprises a luminescent feature substance. An examination of the luminescence Holding the security transfer element can be used for the authenticity check.

A security transfer element with luminescent features made of semiconductor materials is known from EP 1 972464 A1.

The security transfer elements known from the prior art are suitable for using their luminescence behavior for checking the authenticity. However, the test result of the luminescence behavior depends on the value document, for example on its print, substrate or soiling on which the security transfer element is applied.

It is therefore an object of the invention to improve the disadvantages of the prior art. In particular, it is an object of the invention to provide a security element, which enables a secure check of the security element or of the security element layer composite for authenticity and / or completeness and prevents environmental influences.

The object is achieved by a security transfer element, a value document, a test method, a test unit, a value document processing device and / or a system according to the independent claims. Particularly advantageous refinements are the subject of the dependent claims.

A security transfer element according to the invention comprises a security element layer composite and a carrier film. The carrier film is detachably connected to the security element layer composite. The security element layer composite has a functional layer. The functional _S layer has an optically variable effect which unfolds for a viewer of the security element layer composite after transfer to a document of value. This means that when viewed in incident light on an upper side of the functional layer, a variable optical impression is created for a viewer depending on the viewing or lighting angle, for example a changed color impression, a moving pattern or a changed depth effect. The security element layer composite further comprises an adhesive layer. The security element layer composite has an upper side which, after the security element layer composite has been transferred to a document of value substrate, faces the viewer. The adhesive layer, on the other hand, is arranged on the side of the functional layer that lies opposite the top, namely on the bottom of the security element layer composite. Furthermore, the security element layer composite has at least one fuminescent substance. The fuminescent substance is arranged in the adhesive layer and / or in a fuminescent substance layer in the security element layer composite. The fuminescent substance layer is arranged on the side of the functional layer opposite the upper side, preferably between the adhesive layer and the functional layer. The fuminescent substance has primary emission radiation in a wavelength range between 700 nm and 2100 nm. Furthermore, the fuminescent substance can be excited by excitation radiation in a wavelength range between 400 nm and 2100 nm, preferably between 700 nm and 2100 nm. The functional layer is opaque with respect to the emission radiation of the fuminescent substance.

Opaque here means that the transmittance is at most 50%, preferably at most 30%, particularly preferably at most 10%. The functional layer is accordingly designed in such a way that it prevents the emitted radiation from the luminescent substance in a wavelength range from 700 nm to 2100 nm to such an extent that it does not pass through the functional layer, or only to a significant extent, and is recognizable on the upper side of the security element layer composite is. The functional layer can thus be designed to absorb or attenuate and / or preferably reflective for the emission region of the luminescent substance. If the functional layer is designed to be damping, a degree of damping of at least 50%, preferably of 70%, particularly preferably of more than 90%, is provided. In the case of a reflective functional layer, the degree of reflection is preferably more than 50%, particularly preferably more than 80%. The luminescent substance is preferably excited from the underside of the security element layer composite. After excitation, the at least one luminescent substance emits an emission radiation. This passes through the security element layer composite up to the functional layer and preferably does not penetrate or hardly penetrates through the functional layer. The emission radiation of the luminescent substance is not or only barely recognizable on the top of the security element layer composite, but the emission radiation can be recognized from the underside of the security element layer composite, since the emission radiation of the luminescent substance can penetrate to the outside here.

The, preferably wavelength-selective, opacity of the functional layer can be provided by a partial layer of the functional layer. The luminescent substance is particularly preferably arranged in the security element layer composite such that it is arranged below the layer which provides the opacity of the functional layer, ie the luminescent substance is covered by opaque regions of the functional layer. The security element layer composite can preferably be detected over its entire surface area with the aid of the luminescent substance. If the luminescent substance is arranged over the entire surface (in incident light) of the security element layer composite, its completeness can be checked. With the methods of the prior art, the area of a document of value occupied by a security element layer composite is generally omitted during inspection, since an inspection is not or hardly possible due to the optical variability and / or metallized area. If the document of value is forged, the security transfer element could only be partially removed. With the removal, the counterfeiter would also remove at least part of the luminescent substance from the value document. If the security element layer composite were checked for completeness with the aid of, for example, evaluating the intensity distribution of the emission radiation of the luminescent substance on the tested surface of the value document, one would recognize that only a partial area of the surface of the security element layer composite of the value document of the real value document is provided with the luminescent substance. The counterfeit value document can also be identified with the aid of an area evaluation with regard to the intensity values of the emission radiation of the luminescent substance. As a further advantage of the invention, the luminescent substance cannot or hardly can be detected from the top of the security element layer composite. Rather, detection from the underside of the security element layer composite and thus from the value document substrate is possible in particular. The security element layer composite would usually not be recognized by counterfeiters as machine-readable or as luminescent, since detection is typically carried out from the top, but not from the bottom. In one configuration, the layer of the security element layer composite is structured such that when the security element layer composite is detached, only a part of the luminescent substance is removed from a value document substrate and another part remains on the value document substrate. This can result from the material properties of the material surrounding the luminescent substance, for example a luminescent substance layer or adhesive layer, and / or this material is present in a certain geometric shape in the security element layer composite.

If at least a part of the luminescent substance remains on the value document substrate, the forgery can also be detected in the case of two-sided measurement for emission radiation of the luminescent substance by the emission radiation suddenly being detectable from above.

With the security transfer element according to the invention, it is not only possible to check the authenticity of the security element layer composite, but also the integrity of the security element layer composite can be checked.

The emission radiation of the luminescent substance can electromagnetic radiation with several emission bands i.e. over a wide wavelength range. The term primary emission radiation therefore only relates to a certain wavelength range in which the intensity maximum lies and is the largest continuous wavelength range in which the total intensity does not fall below 90% of the maximum.

The luminescent substance of the security element layer composite can be excited by excitation radiation in a wavelength range between 400 nm and 2100 nm. The structure and the safety regulations for this are simple and manageable, so that a simple check of the security element layer composite is possible.

The carrier film can be, for example, a plastic film made of PP, PET, PA, PC, PVC, PTFE or POM. The carrier film can also comprise a metal foil, for example aluminum, copper or stainless steel foils.

If the luminescent substance is disposed in a chicht luminescent substance _S, as may be provided in one embodiment that the Lumineszenzstoff- layer is formed as a plastic layer. As a result, luminescent organic or organometallic dyes can be well dispersed and at the same time protected against chemical attacks.

In one embodiment, the luminescent substance is designed such that its excitability for luminescence lies in the visible spectral range, particularly preferably in the wavelength range between 400 nm and 700 nm. When using the security element layer composite on a document of value substrate, which comprises paper, higher scattering results - Loss of the excitation radiation in the value document substrate and a higher susceptibility to disruptive factors such as dirt, but the range of substances that can be used is expanded, for example pigments, dyes and complexes that can be excited with visible radiation. However, the losses can be more than compensated in part by using the generally stronger excitation sources available for this spectral range.

In one configuration, the luminescent substance is designed such that its excitability lies in the infrared range, particularly preferably in the wavelength range between 700 nm and 2100 nm. In a particularly preferred embodiment, both the excitability and the emission are in the Infrared range. This minimizes the scatter losses that typically occur when the security element layer composite is applied to a value document substrate, which comprises paper. It was surprisingly found that the scattering of the excitation radiation in a document substrate of value, which comprises paper, decreases with increasing wavelength range. In addition, it was surprisingly found that absorptions occurring by z. B. Dirt for electromagnetic radiation in the infrared range is often more permeable than in the visible range.

The security element layer composite is preferably designed such that the luminescent substance can preferably be subjected to excitation radiation from the underside of the security element layer composite. In other words, the layers which are arranged opposite one another from the luminescent substance from the upper side of the security element layer composite are permeable to the excitation radiation to such an extent that the excitation radiation can excite the luminescent substance to luminescence.

In one embodiment it can be provided that the excitation of the luminescent substance can take place from the top of the security element layer composite. For this purpose, at least one layer and / or the material which is arranged on the side of the luminescent substance which is directed towards the upper side of the security element layer composite are designed such that the excitation radiation can reach the luminescent substance _V from the upper side of the security element layer composite and the latter Can stimulate luminescence. The at least one layer and / or the material can be designed such that it conducts electromagnetic radiation, namely the excitation radiation only in the direction of the luminescent substance, but does not conduct electromagnetic radiation, namely the emission radiation, to the surface of the security element layer composite. In one embodiment it can also be provided that excitation of the top and bottom of the security element layer composite is possible.

In one configuration, the security element layer composite can be designed in such a way that an excitation radiation is blocked from the top of the security element layer composite or from the underside of the security element layer composite.

In one aspect of the invention, the primary emission radiation of the luminescent substance is in a wavelength range between 900 nm and 2100 nm. As a result, the luminescence of the security element layer composite cannot be perceived by the human eye, as a result of which greater security is achieved. If the safety transformer ferelement to a value document substrate is applied, wherein the value document substrate, preferably paper contains, undergoes, due to the dependence of the scattering coefficient of the value document substrate from the wavelength, the emission radiation less wastage, so that the emission _S adiation of the luminescent substance, the value document substrate can penetrate without loss.

In one aspect, the primary emission radiation of the luminescent substance lies in a wavelength range between 900 nm and 1300 nm. Detectors of simple construction are already available for the detection of emission radiation in this wavelength range, so that no complex detectors have to be used. A compromise between simple detectability and scattering losses is thus achieved. For example, luminescent substances with a waveband of the primary emission beams are Between 900 nm and 1300 nm doped inorganic pigments with the dopants neodymium or ytterbium or doped with certain transition metals as well as organometallic complexes with neodymium or ytterbium and / or organic dyes, such as. B. cyanine dyes, thiopyrylium dyes such as IR-1061 and / or indolium dyes such as IR-1048. In one configuration, a combination of neodymium and ytterium can also be provided.

In a further aspect, the primary emission radiation of the luminescent substance lies in a wavelength range between 1300 nm and 1600 nm. Here, compared to a wavelength range below 1300 nm, there is again reduced scatter loss in a paper substrate with a value document substrate, and the detectors can still be constructed relatively simply his. However, in the case of cellulose-based substrates of the document of value substrate, there can be a broad absorption band due to a superposition of different O-H stretching vibrations, as a result of which the emission radiation of the luminescent substance is damped. Possible luminescent substances include, for example, inorganic pigments doped with erbium, metal-organic complexes with erbium and / or certain organic dyes.

In a further embodiment, the primary emission radiation of the luminescent substance is in the range between 1600 nm and 1850 nm. In this embodiment, compared to luminescent substances with primary emission radiation in a wavelength range below 1600 nm, there is a further reduced scatter loss when the security element layer composite is used on a value document substrate, encompasses the paper, recognizable. However, both the detector (sensor) and the detection method are more complex. In addition, other materials should preferably be used, namely lent inorganic pigments doped with thulium and / or organometallic complexes with thulium

In one embodiment, the primary emission radiation of luminescence is neszenzstoffs in a wavelength range between 1850 nm and 2100 nm. Here, when using the safety-element layer _V erbunds in com bination with a value document substrate comprises paper, opposite luminescent substances with primary emission at 1850 nm very small, but the detector and the detection method seem complex and complex. It should also be noted that there are oscillation harmonics of the water in this wavelength range, so that the intensity of the luminescent substance also varies with the moisture content of the substrate, which makes detection even more complex. The luminescent substances which have primary emission radiation in a wavelength range between 1850 nm and 2100 nm are, for example, inorganic pigments doped with holmium and / or metal-organic complexes with holmium.

In addition to the dopants mentioned here, further dopants can be provided which, in combination with the rare earth ion, enable energy transfer to this, for example erbium. Furthermore, the dopants, such as neodymium, ytterbium, erbium, thulium and / or holmium, can be present in combination with one another and / or in combination with the other dopants mentioned, in order to adjust and / or omit energy transfer and their respective decay time.

In a preferred embodiment, the luminescent substance is a phosphorescent luminescent substance. In this case, you can also behave in addition to the spectral excitation and emission determine a time behavior, in particular the response time or the decay time, of the emission radiation of the luminescent substance and use it for the authenticity check. This provides increased security since a counterfeiter would have to imitate the time behavior of the luminescent substance. In addition, an increased number of encodings is possible, namely in the differentiation of the security element layer composites used with different attack or decay times.

In one embodiment, the luminescent substance has a decay time of less than 5000 gs, particularly preferably less than 2000 gs, particularly preferably less than 1000 gs. This allows a more precise measurement of the respective decay time even at high transport speeds of the security element layer composite during testing. This is e.g. B. in the case of high-speed sensors for banknotes, in which banknotes typically move through the machine at up to 12 meters per second.

The luminescent substance preferably has a decay time of more than 50 gs, particularly preferably of more than 80 gs, particularly preferably of more than 100 gs. With shorter decay times, a distinction between background fluorescence, e.g. of organic contaminants, increasingly difficult.

In one embodiment, the luminescent substance has no, or a hardly detectable, ie less than 5% of the relative intensity, additional anti-Stokes emission. It can thus be prevented that the security element layer composite can be made visible in the human-visual wavelength range by irradiation using, for example, lasers or other devices for detecting upconversion. In one configuration it can be provided that the security element layer composite has a further luminescent substance. The further luminescent substance is designed such that it can be excited in a first wavelength range and has an emission in a second wavelength range which corresponds to the wavelength range for exciting the luminescent substance, the emission radiation of the further luminescent substance serving the wavelength range Excitation of the luminescent substance corresponds and stimulates this to luminescence. The further luminescent substance thus serves as an intermediate stage for exciting the luminescent substance. For this purpose, the further luminescent substance preferably has a high Stokes shift or a high anti-Stokes shift. The luminescent substance and further luminescent substance can be arranged in a common layer and / or in different layers of the security element layer composite.

The luminescent substance can be an organic or metal-organic luminescent substance, for example fluorescent organic molecules or phosphorescent organometallic complexes. This enables particularly simple incorporation into polymers and into thin layers. B. the substances in it can be molecularly distributed and thus no problems arise from excessive pigment grain sizes.

In a preferred embodiment, these are organometallic complexes. These generally show narrower, more specific emission bands and a large Stokes shift. This facilitates excitation and detection. In particular, the separation of the emission radiation from the excitation radiation and from interference signals is facilitated. The organometallic complexes are preferably rare earth complex, particularly preferably rare earth complexes of the rare earths neodymium, ytterbium, erbium, thulium, holmium or combinations of these of two or more rare earths.

In one embodiment it can be provided that the luminescent substance has a slight Stokes shift with respect to the wavelength ranges of excitability and emission.

In a further embodiment, the luminescent substance is an inorganic luminescent substance. For example, there are doped inorganic matrices (host lattice). Furthermore, the dopants can be the rare earths neodymium, ytterbium, erbium, thulium, holmium or the transition metals vanadium, chromium, manganese, iron. In addition to the dopants mentioned, other dopants may also be present, e.g. B. to adjust the decay time of the luminescent substance and / or to use energy transfers between the rare earth and / or the transition metal and the further dopant.

Suitable inorganic matrices according to the prior art are, for example:

- Oxides, especially 3- and 4-valent oxides such as. B. titanium oxide, aluminum oxide, iron oxide, boron oxide, yttrium oxide, cerium oxide, zirconium oxide, bismuth oxide, and more complex oxides such as. B. grenade, including un ter z. B. yttrium iron grenade, yttrium aluminum grenade, gadolinium gallium grenade; Perovskites, including yttrium aluminum perovskite, lanthanum gallium perovskite, among others; Spinels, including, among others, zinc-aluminum spinels, magnesium-aluminum spinels, manganese-iron spinels; or mixed oxides such as ITO (indium tin oxide); Oxyhalides and oxychalcogenides, especially oxychlorides such as. B. yttrium oxychloride, lanthanum oxychloride; and oxysulfides, such as yttrium oxy sulfide, gadolinium oxy sulfide;

Sulfides and other chalcogenides, e.g. Zinc sulfide, cadmium sulfide, zinc selenide, cadmium selenide;

Sulfates, especially barium sulfate and strontium sulfate;

Phosphates, especially barium phosphate, strontium phosphate, calcium phosphate, yttrium phosphate, lanthanum phosphate, as well as more complex phosphate-based compounds such as e.g. Apatites, including calcium hydroxylapatite, calcium fluoroapatite, calcium chlorapatite; or Spodiosite, including e.g. Calcium fluoro spodiosite, calcium chloro spodiosite;

Silicates and aluminosilicates, especially zeolites such as e.g. Zeolite A, zeolite Y; zeolite-related compounds such as Sodalites; Field spade such as Alkali feldspar, plagioclase; and or

further inorganic compound classes such as Vanadates, Germates, Arsenates, Niobates, Tantalates.

In one embodiment, the security element layer composite can comprise, in addition to the luminescent substance, further luminescent substances, in particular according to one of the luminescent substances described here.

In a further preferred embodiment, the at least one luminescent substance of the security element layer composite is an inorganic luminescent substance. In this way, for example, when using multiple luminescent substances, the simultaneous detection of the luminescent substances is facilitated since their behavior can be better adapted to one another, in particular in their decay time of the phosphorescence and / or width of the emission. According to one aspect, the at least one luminescent substance can have a grain size (D99) of less than 15 μm. The grain size (D99) is preferably less than 8 μm, particularly preferably less than 5 μm. It has surprisingly been found that with a smaller grain size, the trouble-free introduction of the luminescent substance into the security element layer composite is easier. For example, a grain size of 5 ml or less is advantageous when introduced into the adhesive layer with a thickness of 5 μm, since otherwise the layers above or below the adhesive layer may be adversely affected by the outstanding luminescent substance. The specification of the grain size D99 means that 99% of the particles used in the layer, for example in the adhesive layer and / or in the luminescent material layer, have a maximum grain size, for example 5 gm.

The concentration of the luminescent substance is preferably less than 5 percent by weight of the material in which it is contained, particularly preferably less than 1 percent by weight. If, for example, the luminescent substance is introduced into the adhesive of an adhesive layer and / or into the adhesive layer, less than 1 percent by weight of the adhesive consists particularly preferably of the luminescent substance. This can be achieved by using a particularly efficient luminescent substance. This ensures that the function of the material in the security element layer composite, here e.g. the adhesive effect of the adhesive, which does not adversely affect the luminescent substance.

In a preferred embodiment, the luminescent substance has a coating and / or a functionalization in order to improve its introduction. For example, an inorganic luminescent substance with a be provided with an organic shell or an organic surface functionalization in order to enable or improve a dispersion of the luminescent substance in a polymer layer or the adhesive layer.

In a preferred embodiment, the luminescent substance has a similar, preferably an identical, refractive index to the material surrounding it, for example a polymer layer and / or the adhesive layer. The refractive indices preferably differ from one another by less than 30%, particularly preferably by less than 10%. This ensures that the introduction of the luminescent substance does not lead to optical effects such as cloudiness, etc., which can impair the functionality of the security element layer composite.

If the refractive index of the luminescent substance n ₀ deviates greatly from the refractive index of the material n ₂ surrounding it, this can lead to optical effects such as clouding. In order to minimize such turbidity, the luminescent substances can be coated with a refractive index n _{L f} e! ^ jn _a n _z with a defined thickness. The coating thickness must be designed so that the light rays reflected on the luminescent substance and on the coating overlap destructively with a phase difference of p in the spectral range of the highest eye sensitivity (approx. 555 nm).

In one configuration, the refractive index of the adhesive layer can be adjusted by opacifying materials or doping in such a way that its refractive index is increased. For example, opacity of the adhesive point of view, the luminescent substance _S can chicht and / or of the luminescent environmentally giving matrix and / or layer with appropriate materials, such as Ti0 ₂ or other oxides increased and preferably the scatter can be reduced.

In one embodiment, the functional layer has reflective properties. For this purpose, the functional layer can be formed with a reflective surface, preferably on the side of the functional layer which is opposite the upper side, or can have a coating on the upper side of the functional layer. The reflective property relates in particular to electromagnetic rays in a wavelength range of excitability and / or emission radiation from the luminescent substance of the security element layer composite. The luminescent substance is arranged below, ie on the side of the functional layer which lies opposite the top. The reflection of the reflecting surface brings about an increase in the intensity of the excitation radiation from the underside onto the luminescent substance. B. scattered excitation radiation can impinge on the luminescence neszenzstoff so repeatedly, and thus an increase in intensity of the emission of the luminescent substance onsstrahlung on the underside of the safety element layer _V erbunds. Furthermore, the reflective property of the functional layer causes the emission radiation of the luminescent substance to be reflected to the upper side, so that emission of the luminescent substance in areas in which the functional layer has reflective properties is prevented or reduced on the upper side of the security element layer composite. Furthermore, the reflection of the emission radiation of the luminescent substance causes an increase in intensity to the underside of the security element layer composite.

The functional layer can have the reflective property over the entire flat surface of the functional layer (except for the end faces). Furthermore, only one flat side of the functional layer can be used reflective properties include. In addition, the reflective property can also only extend in regions over a (partial) surface of the functional layer, and can for example be designed as a pattern. The functional layer can have a reflective coating, a reflective print and / or a reflective partial layer. For example, the functional layer can be designed as a reflective metal layer and / or have a reflective metal coating. The metal layer and / or the metal coating is preferably arranged on the side of the functional layer which is opposite the viewer and thus the top of the security element layer composite. For example, the metal layer and / or metal coating is an aluminum and / or chrome-based layer or coating.

In one configuration, the functional layer that unfolds the optically variable effect can be designed as a reflective embossed structure, in particular a diffractive structure and / or a reflective microstructure, and / or transparent high-index layers, thin-layer elements with a color-shift effect, in particular with a reflective layer and a semi-transparent one Layer and an intermediate dielectric layer, layers of liquid-crystalline material, in particular cholesteric liquid-crystalline material, printing layers based on effect pigment compositions with viewing angle-dependent effect or with different colors and / or a multi-layer structure, for example two semitransparent layers and one between the two semitransparent layers arranged dielectric layer.

In one configuration, the functional layer of the security element layer composite has an embossing lacquer, for example for forming an embossing lacquer. structure, on. In addition, the embossing lacquer of the security element layer composite can already have an embossing structure. In one configuration, the luminescent substance can be formed in the embossing lacquer, the embossing lacquer on the upper side of the security element layer composite preferably being reflective and / or absorbent for the emission radiation of the first luminescent substance.

In one configuration, the security element layer composite can have a scattering layer with light-scattering properties. The intensity of the excitation radiation which the luminescent substance experiences is increased with the aid of the scattering layer. The scattering layer can be designed as a film with embedded reflecting interfering particles. The scattering layer can be formed, for example, as a polymer layer with embedded cellulose fiber and / or with highly refractive inorganic scattering bodies, for example Ti0 ₂ and / or Zr0 ₂ . In one embodiment, the scattering layer is arranged adjacent to the layer in which the luminescent substance is arranged, for example adhesive layer or luminescent substance layer. Furthermore, it can be provided in one configuration that the luminescent substance is arranged in the scattering layer and / or the scattering layer is part of the functional layer. In one configuration, the scattering layer can be arranged between the adhesive layer and the luminescent substance layer.

Furthermore, plastic layers can be used to adjust the thickness of the security element layer composite, to adapt distances between different layers of the security element layer composite, and / or to influence other properties of the security element layer composite, such as. B. the opacity, the color and / or the deformability of the security element layer _V verbunds. Often there are several layers of plastic directly behind one another, e.g. B. laminated together Foils. Furthermore, the security element layer composite can comprise an embossing lacquer, a protective lacquer, a primer, a printing layer and / or further security elements or a combination of the features mentioned here.

In a further preferred embodiment, the luminescent substance is located in an adhesion promoter layer or in a primer of the security element layer composite. In a further preferred embodiment, the luminescent substance is in the adhesive layer. In these cases, the introduction of the luminescent substance into the security element layer composite is particularly simple and significantly less prone to errors. For example, the introduction and homogeneous dispersion of an inorganic luminescent substance in an adhesive (for example by stirring) is easier than in a plastic layer, since the production process could be hindered when the luminescent substance is introduced into the polymer melt of blown film extrusion. Of course, a combination of the different arrangements of the at least one luminescent substance or different, possibly complementary luminescent substances, for example the further luminescent substance and / or luminescent substances incorporated to detect individual layers, in particular with regard to its layers, is also possible. A special evaluation of the detected radiation with regard to the spectral range can be used, for example, to detect the structure or the layer sequence of the security element layer composite. For this purpose, scatter and / or luminescence behavior of a document of value substrate, for example a paper layer, on which the security element layer composite is applied, can also be included. The luminescent substance can be arranged in the functional layer and / or adhesive layer at least only in regions, for example in the form of a pattern. In one aspect, the pattern can be a coding, in particular a bar code and / or a 2D coding, for example a QR code or a data matrix code. It is therefore possible to obtain data and / or a further proof of authenticity with regard to the evaluation of the data and / or the pattern from the emission radiation for the proof of authenticity based on the emission radiation of the luminescent substance. The opacity of the security element layer composite can extend beyond the pattern of the luminescent substance or the area formed by the luminescent substance and thus completely cover the luminescent substance. In an alternative it can also be provided that the opacity of the security element layer composite covers the pattern of the luminescent substance or the area formed by the luminescent substance only in regions and that at least a partial region of the security element layer composite is designed such that emission radiation of the luminescent substance from the top of the security element layer composite exit. The opacity of the security element layer composite can extend in a pattern-like manner in the security element layer composite such that it forms a common pattern, in particular a coding, with the distribution of the luminescent substance, in particular the pattern of the luminescent substance or the area formed by the luminescent substance. In one embodiment, the opaque surface area of the security element layer composite can be formed as above as an optically variable effect and can comprise, for example, a hologram and / or an embossed pattern and / or as a line, in particular a line grid, as a surface pattern and / or as a metallized surface with demetalization - Be formed and cover the arrangement of the luminescent substance in incident light on the upper side at least in an overlap region. Accordingly, it can be provided that the security element layer composite in Incident light on the upper side thereof has at least one area in which the security element layer composite is not designed to be opaque for the emission radiation of the luminescent substance. Thus, the security element layer composite is designed such that the security element layer composite, in incident light on the top of the security element layer composite, has areas in which the emission radiation of the luminescent substance cannot or hardly emerge, and has areas in which the emission radiation of the luminescent substance can emerge.

In one embodiment, the security element layer composite has a pull-off protection. In this case, the luminescent substance is arranged in a layer of the security element layer composite which is suitable for remaining in whole or in part on the value document when the security element layer composite is pulled off or detached from the value document. This can be, for example, a specially prepared adhesive layer between the security element layer and the valuable document substrate. When the security element layer composite is peeled off, for example in order to produce a counterfeit, the security element layer composite therefore contains no or only a small amount of luminescent substance and is therefore recognized as incorrect. The value document still contains the layer with the luminescent substance of the security element layer composite, but no longer the layer with the optically variable effect, preferably no longer the reflecting or absorbing layer, so that the intensity of the detectable emission radiation on the side, on which the entire security element layer composite was originally attached, is now higher, and still appears weak on the opposite side. Thus, an improper removal (counterfeiting) of the safety-element layer _V are erbunds detected. In a further aspect, a value document is provided. The value document comprises a flat value document substrate and a security element layer composite which is arranged on an upper side of the flat value document substrate. The security element layer composite has a functional layer which, when viewed in incident light on an upper side of the functional layer, has an optically variable effect for an observer, the upper side then facing the observer. Furthermore, the security element layer composite comprises an adhesive layer. The security element layer composite has an upper side which faces the viewer and an underside which faces the value document substrate and lies opposite the upper side. The security element layer composite also has at least one first luminescent substance. The first luminescent substance can be arranged in the adhesive layer and / or in a first luminescent substance layer, which is preferably arranged on the side of the functional layer opposite the upper side of the security element layer composite in the security element layer composite. The adhesive layer is arranged on the side of the security element layer composite and the functional layer, which is opposite the top of the security element layer composite. The security element layer composite is arranged on an upper side of the value document substrate in such a way that the functional layer unfolding the optically variable effect is oriented such that the optically variable effect can be seen in incident light on an upper side of the value document and the security element layer composite in incident light on one Underside of the value document is at least partially, preferably completely covered. When viewed from the underside of the value document, more than 10% of the area of the security element layer composite is preferably covered by the value document substrate. This enables a mechanically secure anchoring of the security element layer composite and an attractive design and one High level of security against forgery through various visual impressions of the security element from the top and bottom of the value document.

The security element layer composite and the document of value substrate can overlap completely or only partially, for example on a window area of the document of value substrate.

The first luminescent substance has primary emission radiation in a wavelength range between 700 nm and 2100 nm. Furthermore, the first luminescent substance can be excited by excitation radiation in a wavelength range between 400 nm and 2100 nm, preferably between 700 nm and 2100 nm. The functional layer is opaque with respect to the emission radiation of the first luminescent substance. The construction and security provisions are clear and simple so that egg ne simple examination of ensuring uniform element layer _V erbunds and value dokuments possible. The opacity of the functional layer can be provided by a partial layer of the functional layer. It is particularly preferred that the first luminescent substance is arranged in the security element layer composite such that it is arranged below the layer which provides the opacity of the functional layer, ie that the luminescent substance is arranged at least on the side of the opaque layer which the Opposite top of the security element layer composite.

The functional layer is accordingly designed in such a way that it prevents the emitted radiation from the first luminescent substance in a wavelength range from 700 nm to 2100 nm to such an extent that it does not pass through the functional layer, or only to a significant extent, and thus at the top of the Security element layer composite is not or hardly detectable. The functional layer can thus be used for emission rich of the first luminescent substance to be absorbent or damping, preferably reflective. If the functional layer is designed to be damping, a degree of damping of at least 50%, preferably at least 70%, particularly preferably at least 100%, is provided.

The degree of reflection is preferably more than 50%, particularly preferably more than 80%.

The intensity of the emission radiation of the first luminescent substance contained in the security element layer composite is therefore higher on the side of the value document that does not carry the security element layer composite than on the side of the value document that carries the security element layer composite, preferably by at least 50% higher preferably at least 70%, more preferably at least 100%. This increases security against counterfeiting, since the first luminescent substance has better camouflage, the security element layer composite has no detectable luminescence when the security element layer composite is measured directly from its top, no counterfeitability is possible through luminescent printing or holistic luminescent elements, and that the associated imitation effort is very high.

The excitation of the first luminescent substance preferably takes place from the underside of the security element layer composite, in particular from the underside of the value document or the value document substrate. After excitation, the first luminescent substance emits emission radiation. This passes through the security element layer composite up to the functional layer and preferably does not penetrate or hardly penetrates through the functional layer. The emission radiation of the first luminescent substance is not, or only barely, recognizable on the upper side of the security element layer composite. bar. The emission radiation, on the other hand, can reach the underside of the security element layer composite _V and thus also into the value document substrate. The document of value substrate is preferably designed such that the emission radiation of the first luminescent substance essentially, ie taking into account any scattering losses that may be present, a high, in particular a sufficient portion of the emission radiation for detection, penetrates the document of value substrate, as a result of which the emission radiation of the first luminescent substance can be determined.

The surface area occupied by the security element layer composite, but at least the surface area occupied by the first luminescent substance, of the value document can thus be recognized. If the document of value is forged, the security element layer composite could only be partially removed. With the removal, the counterfeiter could also remove at least part of the first luminescent substance from the real value document. If the document of value was checked for completeness of the security element layer composite, one would recognize from the areal intensity distribution of the emission radiation of the first luminescent substance that only a partial area of the area of the security element layer composite of the real value document that would normally be present Security element layer composite is covered.

As a further advantage of the invention, the first luminescent substances cannot or can hardly be detected from the top of the security element layer composite. Rather, in particular, detection is possible from the underside of the security element layer composite and thus from the value document substrate. The security element layer composite would normally not be counterfeited as machine-readable or luminescent recognized, since detection typically takes place from the top, but not from the bottom.

Furthermore, a forger could remove the security element layer composite from the value document in such a way that at least a part of the functional layer, which relates to the optically variable effect, is removed, at least part of the first luminescent substances remaining on the value document substrate. To check the integrity of the document of value, a surface test of the intensity course in incident light on the top of the document of value with regard to emission of the first luminescent substances could be used, with the top of the document of value in the area which typically has the security element layer composite, some emission radiation from the remaining first luminescent substance would be recognizable. In the case of an intact security element layer composite, no or a small but essentially homogeneously distributed emission radiation of the first luminescent substance would be recognizable.

With the document of value according to the invention, it is possible not only to check the authenticity of the document of value and the security element group, but also to ensure that they are intact.

The security element layer composite used in the value document can be provided by a security transfer element, as described above.

The document of value substrate on which the security element layer composite is arranged can consist of paper, plastic or a composite of paper and plastic. It is preferably the However, document of value around banknote paper / cotton paper or a composite material containing such paper.

The value document substrate is typically 50-100 gm thick and consists, for example, of a banknote made of paper, typically mainly made of cellulose fibers, inorganic fillers such as e.g. Titanium dioxide and organic aids such as CMC (carboxymethyl celluloses). The fillers create a high spread of the value document substrate and thus an attractive white color impression. In addition, they enable good excitation of the first and / or second luminescent substance, since a high capture cross section of the luminescent centers of the first and / or second luminescent substance is ensured. Furthermore, the document substrate of value can comprise at least one plastic film (for example polymer bank note), but preferably a composite of at least two plastic films. Document substrates of value with a plastic film can have a higher transparency, which makes it easier to excite the first luminescent substances. The value document substrate can, however, also have a more complex structure, and e.g. B. in the case of a composite material which contains at least one plastic film or a plastic core which is surrounded by at least two layers of paper, or contain at least one layer of paper which is surrounded by at least two plastic films (so-called hybrid banknotes).

The value document substrate thus forms the base body of the value document and, due to its thickness and its scattering and absorption properties, is a relevant factor for the attenuation of the excitation radiation and emission radiation of the luminescent substances used in the context of the invention, in particular the first luminescent substance, each of which - Because it has to cross the value document substrate. In one configuration, at least the mean intensity of the emission radiation of the first luminescent substance of the security element layer composite is significantly higher on the underside of the value document than on the top side of the value document, in each case in the surface area of the security element layer composite, preferably none or a negligible one in this area Emission radiation of the first luminescent substance is recognizable on the top of the value document. The functional layer and / or layers above the first luminescent substance are designed for the emitted radiation of the first luminescent substance so that they are a

Prevent penetration. Attenuation of at least 50% is considered significant. The functional layer can thus be designed to be absorbent or damping, preferably reflective, for the emission region of the luminescent substance. A damping design of the functional layer offers the advantage that the damping in the infrared emission range of the luminescent substance can be generated independently of the visual impression, so that there is great freedom in the design of the visual impression of the security element layer composite. On the other hand, a reflective design itself can act as an attractive design feature and is a necessary component of some optically variable elements such as a hologram. If the functional layer is designed to be damping, a degree of damping of at least 50%, preferably of at least 70%, particularly preferably of at least 100%, is provided. The degree of reflection is preferably more than 50%, particularly preferably more than 80%. This enables a secure check of the value document and / or the security element layer composite for forgery and / or for snippet counterfeiting, ie that an area of a real value document has been removed and possibly replaced by a fake area. In one embodiment it can be provided that the document substrate has at least one second luminescent substance. The at least one second luminescent substance can be arranged in the value document substrate, for example in a paper substrate layer and / or in a polymer layer. For this purpose, the second luminescent substance is added to the paper pulp, for example to produce the paper substrate layer in a paper machine. If the value document substrate comprises a polymer layer, the second luminescent substance can be mixed in in an extruder. Of course, the document of value substrate can also comprise a combination of paper substrate and polymer layer. Furthermore, the second luminescent substance can be formed in a print layer on the document substrate of value. The second luminescent substance can be incorporated in a printing ink.

With the help of the second luminescent substance, full coverage of the value document is achieved particularly well.

Furthermore, it can be prevented that the security element layer composite is removed from the value document substrate by detachment with solvents and applied to a fake value document substrate in order to make it appear genuine (for example on a modified certificate or a banknote with a higher denomination). The at least first luminescent substance in the security element layer composite and the at least second luminescent substance in and / or on the value document substrate are preferably matched to one another.

In one configuration of the value document, the first and optionally second luminescent substance are designed such that their excitability by excitation radiation lies in the visible spectral range, in particular preferably in the wavelength range between 400 nm and 700 nm. When using such excitation radiation for excitation through a document substrate, which includes paper, for example, there are higher scatter losses in the document substrate and a higher susceptibility to disruptive factors such as dirt, but the palette is affected usable substances expanded, for example pigments, dyes and complexes that can be excited with visible radiation. However, the losses can be more than compensated in part by using the generally stronger excitation sources available for this spectral range.

In one configuration, the first and second luminescent substances have excitability in the same wavelength range, for example in the visual and / or infrared wavelength range. This enables testing of both luminescent substances with a space- and energy-saving sensor that only provides excitation light of one wavelength.

In one configuration, the first and / or optionally second luminescent substance of the value document are designed such that their excitability by excitation radiation lies in the infrared range, particularly preferably in the wavelength range between 700 nm and 2100 nm. In a particularly preferred embodiment, both the excitation radiation and the emission are in the infrared range. This avoids the scatter losses which typically occur in the case of a document of value substrate, which comprises paper, for example. In addition, often occurring absorptions by z. B. Contamination for electromagnetic radiation in the infrared range is often more permeable than in the visible range.

In one aspect of the invention, the primary emission radiation of the first and / or optionally second luminescent substance of the value document elements in a wavelength range between 900 nm and 2100 nm. As a result, the luminescence of the security element layer composite cannot be perceived by the human eye, as a result of which greater security is achieved. Furthermore, the security element layer composite on the valuable document substrate, which preferably contains paper, experiences less emission losses due to the dependence of the scattering coefficient of the valuable document substrate on the wavelength, so that the emission radiation of the first and / or optionally second luminescent substance can penetrate the valuable document substrate without loss.

In one aspect, the primary emission radiation of the first and / or possibly luminescent substance lies in a wavelength range between 900 nm and 1300 nm. Detectors of simple construction are already available for the detection of emission radiation in this wavelength range, so that no complex detectors have to be used. A compromise between simple detectability and scattering losses is thus achieved. For example, the first and second luminescent substances with a wave range of the primary emission radiation between 900 nm and 1300 nm doped inorganic pigments with the dopants neodymium or ytterbium or doped with certain transition metals as well as organometallic complexes with neodymium or ytterbium and / or organic dyes, such as . B. cyanine dyes, thiopyrylium dyes such as IR-1061 and / or indolium dyes such as IR-1048. In one configuration, a combination of neodymium and ytterbium can also be provided. In one embodiment, a combination of neodymium and yt terbium can also be provided In a further aspect, the primary emission radiation of the first and / or optionally second luminescent substance is in a wavelength range between 1300 nm and 1600 nm. Here, compared to a wavelength range below 1300 nm, there are again reduced scatter losses in a paper substrate in the case of a value document substrate and the detectors ren can still be relatively simple. However, in the case of cellulose-based substrates of the document of value substrate, there can be a broad absorption band due to a superposition of different OH stretching vibrations, as a result of which the emission radiation of the first and / or optionally second luminescent substance is damped. Possible first and / or optionally second luminescent substances are, for example, inorganic pigments doped with erbium, organometallic complexes with erbium and / or certain organic dyes.

In a further embodiment, the primary emission radiation of the first and / or optionally second luminescent substance is in the range between 1600 nm and 1850 nm. In this embodiment, compared to luminescent substances with primary emission radiation in a wavelength range below 1600 nm, the value is further reduced by scattering losses - Document substrate comprising paper. However, both the detector and the detection method are more complex. In addition, other materials should preferably be used, namely inorganic pigments doped with thulium and / or metal-organic complexes with thulium

In one embodiment, the primary emission radiation of the first and / or second luminescent substance lies in a wavelength range between 1850 nm and 2100 nm. Here, when using the security element layer composite in combination with the value document substrate, which preferably comprises paper, compared to luminescent substances with primary ones Emission below 1850 nm is very low, but the detector and the detection method would be more complex and complex. It is also disadvantageous to note that there are oscillation overtones of the water in this wavelength range, so that the intensity of the first and / or possibly second luminescent substance also varies with the moisture content of the substrate, as a result of which the detection is again more complex. The first and / or optionally second luminescent substance which have primary emission radiation in a wavelength range between 1850 nm and 2100 nm are, for example, inorganic pigments doped with holmium and / or metal-organic complexes with holmium.

In one embodiment, the first and second luminescent substances overlap at least partially in a wavelength range of their emission radiation, in particular the emission wavelength range of the second luminescent substance can match that of the first luminescent substance. As a result, the first luminescent substance of the security element layer composite can no longer or only with difficulty be examined independently of the second luminescent substance of the valuable document substrate, which is preferably present over the entire surface. In one embodiment, it can be provided that the wavelength ranges of the emission of the first and second luminescent substances complement one another and / or overlap in regions. With the aid of a spectrally resolving detector, the supplementary spectrum can additionally be used as security evidence, in particular whether the first and second luminescent substances are present in the detected area. The supplementary and possibly overlapping spectrum can be determined with the aid of the amount and the type of the first and second luminescent substances used.

In a further embodiment, the first and second luminescent substances luminesce in different spectral ranges. As a result, a higher number of separable codings is achieved. Furthermore, a separate evaluation of the emissions is easier.

In a preferred embodiment, the first and / or second luminescent substance phosphoresce. In this case, in addition to the spectral excitation and emission behavior, the decay time of the respective emission can also be determined. This provides increased security, since a counterfeiter would have to imitate the time behavior. In addition, an increased number of codings is possible, namely in the differentiation of the security element layer composites with different attack or decay times.

In one embodiment, the first and / or second luminescent substance have a decay time of less than 5000 gs, particularly preferably less than 2000 gs, particularly preferably less than 1000 gs. This allows a more precise measurement of the respective decay time even at high transport speeds of the value document. This is e.g. B. at high speed sensors for banknotes, where banknotes typically move through the machine at up to 12 meters per second.

The first and / or second luminescent substance preferably have a decay time of more than 50 gs, particularly preferably more than 80 gs, particularly preferably more than 100 gs. With shorter decay times, a distinction between background fluorescence, e.g. of organic contaminants, increasingly difficult.

In one configuration, the first and second luminescent substances are based

on neodymium or ytterbium or a combination of neodymium and ytterbium, the first luminescent substance preferably being different from the second luminescent substance, and / or

on transition metals with an emission in the wavelength range between 900-1300 nm, the first luminescent substance preferably being different from the second luminescent substance, and / or on erbium, on thulium, and / or on holmium, the first luminescent substance preferably being from second luminescent substance differs.

It is thereby achieved that the first and second luminescent substances emit in a similar wavelength range, ie both substances emit together in one of the spectral ranges mentioned here, such as 1300 nm - 1600 nm, 1600 nm - 1850 nm and 1850 nm - 2100 nm of the similar wavelength ranges it is achieved that the first and second luminescent substances emit in the same spectral range. Furthermore, the security can be increased, since it is more difficult, especially in the long-wave regions, for the first and second luminescent substances to be independent of to detect each other. As an additional advantage, the detector structure becomes easier, especially in the short-wave areas, since only a limited area has to be checked.

In a further embodiment, the first and second luminescent substances are selected such that they emit in different spectral ranges. This enables more encodings to be generated. Furthermore, the separate evaluation of emissions is technically easier.

In one embodiment, the first and the second luminescent substance have a common excitation. In a further embodiment, the first and second luminescent substances are excited via the same rare earth ion, but emit via different rare earth ions. For example, the first luminescent substance contains neodymium and the second luminescent substance contains neodymium and ytterbium at the same time. The first luminescent substance is excited in the neodymium and emitted via the neodymium. The second luminescent substance is excited in the neodymium and emits via the ytterbium after an energy transfer. As a result, both substances can be excited by a common wavelength, which simplifies the process. Furthermore, security is increased due to more complex luminescent substances.

In one configuration, the first and second luminescent substances are coordinated with one another in such a way that the wavelength range of the emission radiation and / or wave range for excitation of the second luminescent substance essentially corresponds to the wavelength range of the emission radiation and / or the wave range for excitation of the first luminescent substance of the security element layer composite. In a further embodiment, the first luminescent substance can have a complementary luminescent behavior to the second luminescent substance. This means that the luminescence of the first luminescent substance differs in its excitation, its emission and / or its decay. As a result, the two luminescent substances can be detected separately from one another and used for the authenticity check.

In one embodiment, the first and / or optionally second luminescent substance have no or hardly detectable, i.e. less than 5% of relative intensity, additional anti-Stokes emission. It can thus be prevented that the document of value can be made visible in the human-visual wavelength range by irradiation using, for example, lasers or other devices for detecting upconversion.

The first and / or optionally second luminescent substance can be organic or organometallic luminescent substances, for example fluorescent organic molecules or phosphorescent organometallic complexes. This enables a particularly simple introduction into polymers and thin layers, since z. B. the substances in it can be molecularly distributed and thus no problems arise from excessive pigment grain sizes.

In a preferred embodiment, the first and / or the optionally second luminescent substance are organometallic complexes. These generally show narrower, more specific emission bands and a large Stokes shift. This facilitates excitation and detection. In particular, the separation of the emission radiation from the excitation radiation and from interference signals is facilitated. The organometallic complexes are preferably rare earth complexes, in particular it also prefers rare earth complexes of the rare earths neodymium, ytterbium, erbium, thulium, holmium.

In a further embodiment, the first and / or optionally second luminescent substance are inorganic luminescent substances. For example, these are doped inorganic matrices (host lattices). Furthermore, the dopants can be the rare earths neodymium, ytterbium, erbium, thulium, holmium or the transition metals vanadium, chromium, manganese, iron. In addition to the dopants mentioned, other dopants may also be present, e.g. B. to adjust the decay time of the first and / or optionally second luminescent substance or to use energy transfers.

Suitable inorganic matrices according to the prior art are, for example:

Oxides, especially 3- and 4-valent oxides such as. B. titanium oxide, aluminum oxide, iron oxide, boron oxide, yttrium oxide, cerium oxide, zirconium oxide, bismuth oxide, and more complex oxides such as. B. grenade, including un ter z. B. yttrium iron grenade, yttrium aluminum grenade, gadolinium gallium grenade; Perovskites, including yttrium aluminum perovskite, lanthanum gallium perovskite, among others; Spinels, including, among others, zinc-aluminum spinels, magnesium-aluminum spinels, manganese-iron spinels; or mixed oxides such as ITO (indium tin oxide);

- Oxyhalides and oxychalcogenides, especially oxychlorides such as. B. yttrium oxychloride, lanthanum oxychloride; as well as oxysulfides, e.g. Yttriumoxy sulfide, gadoliniumoxy sulfide;

Sulfides and other chalcogenides, for example zinc sulfide, cadmium sulfide, zinc selenide, cadmium selenide; Sulfates, especially barium sulfate and strontium sulfate;

In a further preferred embodiment, the first and / or optionally second luminescent substance is an inorganic luminescent substance. This facilitates the simultaneous detection of the luminescent substances, since their behavior can be better adapted to one another, in particular in their decay time of the phosphorescence and / or the width of the emission.

In one embodiment, the first luminescent substance can the safety element layer erbunds _V and / or the second luminescent substance the Wertdo- kumentsubstrats at least two of the luminescent substances described herein include.

In a preferred embodiment, the first luminescent substance is an organic or organometallic luminescent substance and the second luminescent substance is an inorganic luminescent substance, or vice versa. In general, however, inorganic luminescent Zenzstoffe better for full-surface incorporation in the value document substrate, especially in a paper layer of cellulose-based value documents.

In one aspect, the first and second luminescent materials can have a grain size (D99) of less than 15 gm. The grain size (D99) is preferably less than 8 gm, particularly preferably less than 5 gm. It has surprisingly been found that with a smaller grain size, the trouble-free introduction of the first and / or optionally second luminescent substance into the security element layer composite or into the value document substrate is easier. For example, when introduced into the adhesive layer with a thickness of 5 μm, a grain size of 5 μm or less is also advantageous, since otherwise the layers above or below the adhesive layer may be adversely affected by the outstanding luminescent substance. The specification of the grain size distribution D99 means that 99% of the particles used in the layer, for example in the adhesive layer and / or in the luminescent substance layer, have a maximum grain size, for example 5 gm.

The concentration of the first and / or optionally second luminescent substance is preferably less than 5 percent by weight of the material in which it is contained, particularly preferably less than 1 percent by weight. If, for example, the first and / or optionally second luminescent substance is introduced into the adhesive of an adhesive layer and / or into the adhesive layer or into the value document substrate, there is particularly preferably less than 1 percent by weight of the surrounding material, for example the adhesive. from the first or optionally second luminescent substance. This can be achieved by using particularly efficient luminescent substances. This ensures that the function of the material rials in the security element layer composite, here for example the adhesive effect of the adhesive, is not adversely affected by the first luminescent substance. In one embodiment it can be provided that the security element layer composite is designed such that, in particular in the adhesive layer, poorly adherent surface areas formed with luminescent substances are combined with strongly adherent regions formed without luminescent substances and in particular form a pattern, for example, around a Describe the targeted detachment behavior of the security element layer composite from the value document substrate and / or to enable a targeted separation of the security element layer composite if the luminescent substances are arranged in an intermediate layer of the security element layer composite, for example in the luminescent substance layer.

In a preferred embodiment, the first luminescent substance has a coating and / or a functionalization in order to improve its introduction. For example, an inorganic luminescent substance can be provided with an organic shell or an organic surface functionalization in order to enable or improve its dispersion in a polymer layer or the adhesive layer.

In a preferred embodiment, the first and / or optionally second luminescent substance have a similar, preferably an identical, refractive index to the material surrounding it, for example a polymer layer and / or the adhesive layer. The refractive indices preferably differ from one another by less than 30%, particularly preferably by less than 10%. This ensures that the introduction of the first and / or possibly second luminescent substance does not lead to optical effects such as clouding, etc., which lity of the value document, in particular in the area of the security element layer composite.

If the refractive index of the first and / or possibly second luminescent substance n ₀ deviates greatly from the refractive index of the material surrounding it n ₂ , this can lead to optical effects such as clouding. In order to minimize such cloudiness, the first and / or optionally second luminescent substance can be provided with a coating with the refractive index 1 ® ^ jn ₀ n ₂ with a defined thickness. The coating thickness must be designed so that the light rays reflected on the first and / or possibly second luminescent substance and on the coating in the spectral range of the highest eye sensitivity (approx. 555 nm) are as destructive as possible with a phase difference of p overlay tiv.

In one embodiment, the functional layer of the safety element layer _V erbunds reflective properties. For this purpose, the functional layer can be formed with a reflective surface, preferably on the side of the functional layer which is opposite the upper side. The reflective property relates in particular to electromagnetic rays in a wavelength range of the emission radiation of the first luminescent substance of the security element layer composite. The first luminescent substance is arranged below, ie on the side of the functional layer which lies opposite the top. The reflection of the reflecting surface brings about an increase in the intensity of the excitation radiation from the underside to the first luminescent substance, since z. B. scattered excitation radiation can hit the first luminescent substance several times, and an increase in intensity of the emission radiation of the first luminescent substance. effect on the underside of the security element layer composite. Furthermore, the reflective property of the functional layer causes the emission radiation of the first luminescent substance to be absorbed towards the upper side, so that the emission of the first luminescent substance is prevented or reduced in areas in which the functional layer has reflective properties.

The functional layer of the security element layer composite can have the reflective property over its entire flat surface (except for the end faces). Furthermore, only one flat side of the functional layer can comprise reflective properties. A full-surface design of the reflective property enables good visibility of the optically variable effect over the entire surface of the security element layer composite. In addition, the reflective property can also only extend in regions over a surface of the functional layer and can be designed, for example, as a pattern. The functional layer can have a reflective coating, a reflective print and / or a reflective partial layer. For example, the functional layer can be designed as a reflective metal layer and / or have a reflective metal coating. This is an attractive design element and robust against environmental influences. The metal layer and / or the metal coating is preferably arranged on the side of the functional layer which is opposite the viewer and thus the top of the security element layer composite. As a result, the metal layer is protected against abrasion and can have a height profile, for example in order to form a reflective embossed structure. For example, the metal layer and / or metal coating is an aluminum and / or chromium-based layer or coating. In one configuration, the functional layer of the security element layer composite which exhibits the optically variable effect can be designed as a reflective embossed structure, in particular a diffractive structure and / or a reflective microstructure, and / or transparent highly refractive layers, thin-layer elements with a color-shift effect, in particular with a reflective layer and a semitransparent layer and a dielectric layer arranged in between, layers of liquid-crystalline material, in particular of cholesteric liquid-crystalline material, printing layers based on effect pigment compositions with viewing angle-dependent effect or with different colors and / or a multilayer structure, for example two have semitransparent layers and a dielectric layer arranged between the two semitransparent layers. For example, the functional layer can have a hologram, micromirror and / or optically variable color.

In one embodiment, the functional layer of the security element layer composite has an embossing lacquer, for example for forming an embossing structure. In addition, the embossing lacquer of the security element layer composite can already have an embossing structure. In one configuration, the at least one first fuminescent substance can be arranged in the embossing lacquer, the embossing lacquer preferably being formed on the upper side of the security element layer composite in a reflective and / or absorbing manner for the emission radiation of the first fuminescent substance.

Plastic layers can furthermore be used to adjust the thickness of the security element layer composite, to adapt distances between different layers of the security element layer composite, and / or to add other properties of the security element layer composite affect how z. B. the opacity, the color and / or the deformability of the security element layer _V verbunds. Often there are several layers of plastic directly behind one another, e.g. B. in the form of laminated films. Furthermore, the security element layer composite can comprise an embossing lacquer, a protective lacquer, a primer, a printing layer and / or further security elements or a combination of the features mentioned here.

In one configuration, the security element layer composite can have a scattering layer with light-scattering properties. The intensity of the excitation radiation which the first luminescent substance experiences is increased with the aid of the scattering layer. The scattering layer can be designed as a film with embedded reflecting interfering particles. The scattering layer can be formed, for example, as a polymer layer with embedded cellulose fiber and / or with highly refractive inorganic scattering bodies, for example T1O2 and / or Zr0 ₂ . In one configuration, the scattering layer is arranged adjacent to the layer in which the first luminescent substance is arranged, for example adhesive layer or luminescent substance layer. Furthermore, it can be provided in one configuration that the first luminescent substance is arranged in the scattering layer and / or the scattering layer is part of the functional layer.

The document of value substrate can likewise comprise at least one scattering layer which is constructed and acts similarly to the scattering layer of the security element layer composite, but with regard to the first and optionally second luminescent substance. If the document of value substrate comprises a plastic layer, this plastic layer can be designed as a scattering layer. For this purpose, it preferably contains cellulose fiber and / or fillers, preferably titanium dioxide or carboxymethyl cellulose. This enables one good excitation of the first and / or second luminescent substance, since a high capture cross section of the luminescent centers of the first and / or second luminescent substance is ensured. Furthermore, a print layer and / or a print acceptance layer of the value document substrate can assume the function of a scatter layer.

In one aspect, the value document can have printing, for example in the form of a printing layer. The printing of the value document, e.g. B. by offset or steel intaglio printing, creates a continuous or only partially available (eg halftone printing, line screen, barcode, ...) layer of printing inks or pigmented printing varnishes on both sides of the value document substrate, which is also referred to as an printing ink layer . It typically contains organic or inorganic pigments or organic dyes which absorb strongly in the visible wavelength range and / or in the infrared wavelength range. Although it is very thin relative to the value document substrate, it can, depending on the position of its absorption bands, bring about a significant weakening of the excitation radiation or emission radiation of the first and / or possibly second luminescent substance.

In addition to the value document substrate and print layer, the value document can be constructed in a significantly more complex manner and, for example, B. have a sizing, a protective lacquer layer or other functional layers, or have other security elements, such as. B. mottled fibers or a watermark.

In one embodiment it can be provided that the printing layer, in particular the positioning of the printing pigments and / or the printing lines, and the security element layer composite are matched to one another. In In one aspect, it can be provided that no printing pigments and / or printing ink are arranged in the areas of the value document in which the security element layer composite is arranged. In a further aspect, the printing pigments and / or printing ink at least partially overlap with the security element layer composite. Printing pigments and / or printing ink and / or printing lines are generally provided with dyes in the visual spectrum. However, printing pigments and / or printing inks which have absorption bands in the infrared range can also be used. Depending on the application, in particular the criteria according to which an authenticity check of the value document is carried out, absorption in the infrared range can have a positive effect, in particular in the wavelength range of the NIR (near infrared).

The absorption of the printing pigments and / or the printing ink can be reduced, for example, by halftone printing or similar techniques, so that not an entire area is printed with printing pigments and / or printing ink, but only a part between the halftone lines or halftone dots remains unprinted. The proportion of unprinted area directly below the security element layer composite on both sides of the value document substrate is preferably more than 30%, particularly preferably more than 50%, more preferably more than 70%. This achieves a compromise between the printing and the usability of the security element.

In one embodiment, the absorption spectrum of the printing layer and the emission spectrum of the first luminescent substance are matched to one another. This means that directly below the security element layer composite on both sides of the value document substrate, only print layers are selected whose absorption bands are not with the excitation radiation. or the emission radiation match or interact only to a small extent. Respectively, the excitation and emission radiation of the first luminescent substance are selected such that they each fall into an absorption gap in the print layer.

The print layer preferably absorbs less than 10% of its maximum absorption in the region of the excitation radiation of the first luminescent substance, particularly preferably less than 5%. The print layer preferably absorbs less than 10% of its maximum absorption in the region of the emission radiation of the first luminescent substance, particularly preferably less than 5%.

In one configuration it can be provided that the positions of the first and second luminescent substances are coordinated with one another. The first and second luminescent substances can be arranged such that they do not overlap or overlap in a certain pattern. Thus, for example when using the value document as bank notes, denomination-specific overlap areas and / or patterns can be generated.

In a further preferred embodiment, the first and / or second luminescent substance, if any, are located in an adhesion promoter layer or in the primer of the security element layer composite or of the value document substrate. In a further preferred embodiment, the first luminescent substance is in the adhesive layer. In these cases, the introduction of the at least first luminescent substance into the security element layer composite is particularly simple and significantly less susceptible to errors. For example, the introduction and homogeneous dispersion of an inorganic luminescent substance in an adhesive (eg by stirring) is easier than in a plastic layer. For example, a blown film extrusion could introduce the manufacturing process into the polymer melt be hindered. In particular, for purposes of quality assurance, it can also be demonstrated that the security element layer composite is correctly applied to the value document substrate. This can, for example, on an application machine development at a final _V and / or currency rend carried out a final inspection.

The first luminescent substance can be used in the functional layer and / or in the adhesive _S chicht only be arranged as area, for example in the form of a pattern. In one aspect, the pattern can be a coding, in particular a bar code and / or a 2D coding, for example a QR code or a data matrix code. It is thus possible to obtain data and / or a further proof of authenticity with regard to the evaluation of the data and / or the pattern from the emission radiation for the proof of authenticity based on the emission radiation of the first luminescent substance. In one embodiment, the first and second luminescent substances can be combined to form a pattern, so that data can only be obtained or the authenticity of the value document can be determined when the first and second luminescent substances, in particular their related patterns, are correlated. And the code can contain information about the luminescent substance and / or its properties.

In one embodiment, the security element layer composite has a pull-off protection. In this case, the first luminescent substance is arranged in a layer of the security element layer composite which is suitable for remaining wholly or partly on the value document when the security element layer composite is pulled off or detached from the value document. This can be, for example, a specially prepared adhesive layer between the security element layer composite and the value document substrate. When removing the security element _S chichtverbunds to prepare, for example, a fake security element layer composite thus contains no first luminescent longer and is therefore recognized as false. The value document still contains the layer with the first luminescent substance of the security element layer composite, but no longer the optically variable effect, preferably no longer the reflecting or absorbing layer, so that the intensity of the detectable emission radiation on the side on which the entire security element layer composite was originally attached, is now higher, and now only appears weaker on the opposite side. Removal of the security element can thus be detected.

In one embodiment of the value document, the value document substrate has a Kubelka-Munk scatter coefficient with a value between 10 and 80 V _mm in a wavelength range from 400 nm to 2100 nm. It was surprisingly found that such value document substrates have particularly high transmission properties for emission radiation in a wavelength range from 400 nm to 2100 nm. Adequate transmission of the excitation radiation through the value document substrate is also ensured, so that the first luminescent substance receives sufficient excitation. In addition, sufficient transmission of the emission radiation of the security element layer composite is guaranteed by the value document substrate in order to detect it on the underside of the value document. Furthermore, a high scatter of the value document substrate enables good excitation of the first and / or second luminescent substance, since a high capture cross section of the luminescence centers of the first and / or second luminescent substance is ensured. With the Kubelka-Munk scattering coefficient of 80 · / _mm in a wavelength range from 400 nm to 2100 nm, a sufficient balancing act has been created between sufficient transmission and high scatter. In a further aspect, a method for checking a value document according to the invention, as described herein, is disclosed. The process includes the steps:

- Exposing the document of value with an excitation radiation in the

Incident light on the underside of the document of value, the excitation radiation comprising the wavelength range of the excitation radiation of the at least one first luminescent substance of the security element layer composite;

- Detecting an emission, in particular a spectral, a ringing and / or a decaying behavior of the emission radiation, of the first luminescent substance of the security element layer composite on the underside of the document of value over at least a surface area of the document of value; and

- Determining the authenticity of the security element layer composite from the detected emission, in particular from the response and / or decay behavior of the detected emission.

According to one embodiment, it can be provided that the area of the document of value comprises the area of the security element layer composite and preferably a surrounding area of the security element layer composite which has an area of at least 100% of the area of the security element layer composite. This ensures that the maximum luminescence intensity from Sicherheitselement- _S can be detected chichtverbund.

In one embodiment it can be provided that the detected emission, in particular the detected attack and / or the detected decay behavior, is preferably a two-dimensional les pattern results, and the pattern corresponds to the type of security element layer composite. This results in increased security against forgery, since the pattern in the luminescence behavior can be related to the visual impression of the security element layer composite.

In one embodiment it can be provided that at least two surface areas are selected for the detection of the emission, in particular the spectral, response and / or decay behavior. Furthermore, or in addition, the application of excitation radiation can be provided on at least two surface areas. The respective surface areas can differ in location and size both for detection and for application.

In a preferred embodiment, the optionally present second luminescent substance is detected simultaneously with the first luminescent substance. A plausibility check is preferably carried out on the basis of the intensity of the emission radiation of the first and second luminescent substances. This means that if the intensity of the first luminescent substance is reduced compared to the expected value, for example because the banknote is heavily soiled, the luminescent intensity of the second luminescent substance could also be reduced. Such effects can be taken into account by simultaneously measuring the first and second luminescent substances.

In one embodiment it can be provided that the method further comprises the following steps:

Exposing the document of value with an excitation radiation in the

Incident light on the top of the document of value with excitation radiation, the excitation radiation covering the wavelength range of Comprises excitation radiation of the first luminescent substance of the security element layer composite;

Detecting an emission, in particular a spectral, a ringing and / or a decaying behavior of the emission radiation, of the first luminescent substance of the security element layer composite on the upper side of the document of value over at least a surface area of the document of value; and

Comparing the emission of the first luminescent substance detected on the top and the bottom of the value document

Authenticity check of the value document, e.g. Compare the respective response or decay behavior.

The emission radiation is thus not only detected on the side of the value document that does not carry the security element layer composite, but also on both sides of the value document. This results in a more reliable authenticity check. The emission radiation detected on the respective pages of the value document can be compared with one another. The steps for checking the two sides of the value document can take place successively, if necessary with the same checking unit, or can take place simultaneously, eg B. by using an additional detection device on the opposite side of the value document. .

In one embodiment, in addition to the first luminescent substance, the security element layer composite can comprise at least one further luminescent substance, preferably a plurality of luminescent substances, and / or the value document substrate in addition to the second luminescent substance, at least one further luminescent substance, preferably a plurality of luminescent substances. These additional luminescent substances of the value document substrate and / or the security element layer composite can Substances and / or combinations of the luminescent substances described here and / or the same composition as the first or second luminescent substance.

The first and optionally second luminescent substance and / or additional luminescent substance can each be designed such that at least one of the luminescent substances excites another of the luminescent substances with its emission radiation, with their excitation wavelength ranges preferably differing at least in regions. The existence of several luminescent substances can thus be proven with only one excitation radiation. The first and optionally second luminescent substance and / or additional luminescent substance are preferably arranged in different layers and / or at a defined distance from one another in the value document.

For this purpose, the luminescent substances can comprise a combination of at least two of the dopants mentioned here with, for example, rare earth and other dopants, the excitation preferably being in one doping and, due to an energy transfer, the emission being in another doping.

The at least one first and at least one second luminescent substance are preferably designed as particles.

In a further aspect, the invention relates to a checking unit (referred to in the example as a sensor) for checking the documents of value for authenticity, denomination and / or fitness. The test unit has an excitation device for emitting the excitation radiation for the luminescent substances, and a detection device for detecting the emission radiation of the luminescent substances. neszenzstoffe and an off _W erteeinrichtung for testing the authenticity of the value document JE weiligen based on the detected emission radiation. The test unit is designed to carry out a method as described above.

In a further aspect, the invention relates to a value document processing device. The value document processing apparatus comprises an interface for supplying documents of value, for example, the orrichtung an input unit for inputting to be checked documents of value in the Wertdokumentbe- processing type _V, the above-mentioned checking unit for checking documents of value and at least one output unit for outputting the checked documents of value from the value document processing device.

Furthermore, one aspect of the invention relates to a system consisting of an above-mentioned inspection unit or document processing device and a document of value. The checking unit or value document processing device is designed to check the value document, the value document being designed as stated above. The test unit and the value document management layer composite particular the security element or the safety component are adapted to one another that an excitation _S adiation the excitation means capable of exciting (first) luminescent substances of the security element layer composite and the detection device is formed, the emission radiation of the first To detect luminescent substances. In particular, the wavelength ranges of the excitation radiation and / or emission radiation can be adapted to the system of value document and test unit or value document processing device, since different luminescent substances can be used depending on the value document type. Furthermore, the positions of the excitation device and the detection device on the test unit can be adapted to the value document types that are to be tested with the test unit. In one aspect of the invention there is provided a method for checking a value document, the value document having a value document substrate and a security element and the security element for an observer in light on an upper side of the value document at least partially having an optically variable effect, and the value document (inside or outside of this security element) has at least one luminescent substance, the luminescent substance preferably having primary emission radiation in the wavelength range between 700 nm and 2100 nm and preferably with excitation radiation in the wavelength range between 400 nm and 2100 nm, in particular between 700 nm and 2100 nm, is excitable; wherein the security element in incident light on the top of the value document partially or completely covers the luminescent substance, the value document being designed such that emission radiation from the luminescent substance to the top of the value document in the areas in which the security element in incident light is on the top side of the value document covers the luminescent substance, is prevented, provided. The process includes the following steps:

Applying an excitation radiation in incident light onto an underside of the value document, the excitation radiation comprising the wavelength range for excitation of the luminescent substance of the value document;

Detecting an emission, in particular a response and / or a decay behavior of the emission radiation, of the luminescent substance on the underside of the value document over at least one area of the value document; and

Determining the authenticity of the value document from the detected emission, in particular from the response and / or the decay behavior. This method enables a particularly high level of protection against forgery, since the luminescent substance is also checked in areas in which its emission does not emerge from the top of the value document.

With the usual procedures for checking documents of value, areas with optical variable effects are specifically hidden because they are difficult to detect and detect due to the optical variability. With the aid of the test methods proposed here, it is now possible to test areas, in particular security elements with an optically variable effect, for existence and forgery. Furthermore, the quality and fitness of the security element producing the optically variable effect can be analyzed and checked, for example during a check on the underside and top of the value document, which can be carried out, for example, since the intensity value of the emission radiation of the luminescent substance, which is determined on the top of the value document, does not meet the standard values or limit value ranges. In addition, damaged documents of value and / or forged documents of value can be determined, for example, on account of disturbances in the intensity values and / or their areal distribution on the top and / or bottom. In addition, the presence of the security features, in particular the areas relating to the optically variable effect, is possible.

The value document substrate can be configured as stated above. As stated above, the security element can be an imprint, for example made of an ink with optically variable pigments, a thread, a strip, a patch, one or more coatings and / or another security element, which visually can include variable effect as already described. In one configuration, the method can be expanded to include the steps, as already explained for the previous method according to the invention, for example checking on two sides of the value document and evaluating it.

In one embodiment, the method is carried out by a test unit or value document processing device. The invention is explained further below by way of example with reference to the drawings. Show it:

La, b are schematic and exemplary representations of a security transfer element according to the invention;

2a-d show a schematic view of a structure of a value document according to the invention; and

3a, b are schematic representations of a test method of a

Document of value according to the invention.

In the exemplary embodiments, several (first) luminescent substances in the security element layer composite or, if appropriate, several (second) luminescent substances in the value document substrate are described. Of course, only one luminescent substance can also be arranged in the security element layer composite or, if appropriate, in the value document substrate.

Figures la and lb each schematically show an embodiment of a security transfer element according to the invention. A security transfer element 20 in the form of a security strip is shown in FIG. poses. The security transfer element 20 comprises a carrier film 21 made of, for example, PET. A security element layer composite 200 is detachably arranged on the carrier film 21. The security element layer composite 200 comprises a functional layer 210 and an adhesive layer 220. The functional layer 210 has an embossing lacquer 211 with an embossing structure 212, the side of the embossing lacquer 211 which is not provided with the embossing structure 212 facing the carrier film 21. The embossing lacquer 211 is coated on the side of the embossing structure 212 with a metallization 213, for example an aluminum layer. The metallization 213 adapts to the shape of the embossing lacquer 211 and thus to the embossing structure 212. Metallization of the Me-213 continues the adhesive _S chicht arranged 220th The adhesive layer 220 comprises several first fuminescent substances.

A further security transfer element 20 according to the invention is shown in FIG. 1b and constructed similarly to the security transfer element 20 from FIG. For the sake of simplification and easier understanding, the differences are mainly dealt with. The same and similar features are provided with the same reference symbols for better understanding. The security transfer element 20 likewise has a carrier film 21, which is releasably connected to a security element layer composite 200. The security element layer composite 200 comprises an embossing lacquer 211 with an embossing structure 212, a metallization 213 which is arranged on the side of the embossing lacquer 211 which lies opposite the carrier film 21, and a fuminescent substance layer 214 in which first fuminescent substances are arranged. An adhesive layer 220 is arranged on the fuminescent substance layer 214.

The security transfer element 20 of FIGS. 1 a and 1 b can be applied to a value document substrate (cf. FIG. 2 ad). This will be Security transfer element 20 placed on the value document substrate and connected to the value document substrate by activating the adhesive layer 220. Subsequently, the carrier film 21 detachably connected to the security element layer composite 200 is removed. Only the security element layer assembly 200 remains on the value document substrate. The security element layer assembly 200 is then arranged on the value document in such a way that an observer in incident light on the security element layer assembly 200 (top side) can perceive the embossed structure 212 in such a way that it is optically more variable Effect when changing the viewing angle. The metallization 213 serves as a reflector.

If the first luminescent substances of the luminescent substance layer 214 or the adhesive layer 220 are excited, their emission radiation is reflected by the metallization 213 in a direction which is not directed towards the upper side of the value document, but towards the substrate. Emission radiation of the first luminescent substances can only be detected from the underside of the value document.

The embossing lacquer 211, the metallization 213 and / or the luminescent substance layer 214 do not have to extend over the entire security transfer element 20. Rather, it is also conceivable that each of the layers is only applied in regions. In the examples of pigments 1 a and 1 b, puncture layer 200 has a cutout.

Exemplary and schematic embodiments of a value document 30 according to the invention are shown in pigments 2a to 2d. In a first variant according to FIG. 2a, a value document 30 has a value document substrate 300. The value document substrate 300 comprises a value document substrate layer 320, which is printed with a printing layer 330, which in the present example is a printing ink layer 330. A security element layer composite 200 is arranged on the upper side of the value document substrate 300, namely on the printing ink layer 330. The security element layer composite 200 is thus separated from the value document substrate 300 by the printing ink layer 330. The side of the value document substrate 300 on which the security element layer composite 200 faces an observer is the top side of the value document 30.

The security element layer composite 200 is designed, for example, as shown in FIGS. 1 a or 1 b. The security element layer composite 200 comprises a functional layer and first luminescent substances. The functional layer is designed such that emission radiation from the first luminescent substances does not emerge at the top of the value document 30. Rather, the emission radiation of excited first luminescent substances penetrates through the printing ink layer 330 and the value document substrate layer 320 and emerges from the underside of the value document 30.

In order to detect the luminescent substances of the security element layer composite 200, ie the first luminescent substances, an excitation radiation must first cross the document substrate 300. The emission radiation of the excited first luminescent substances must then likewise cross the value document substrate 300 in the opposite direction. As a result, the luminescence can be considerably weakened, inter alia, by scattering in the value document substrate 300 and absorption by the printing ink layer 330. A value document 30 according to the invention is shown in FIG. 2b. The value document from FIG. 2b differs from the value document 30 from FIG. 2a in that the printing ink layer 330 is not only applied to the value document substrate layer 320. In the exemplary embodiment in FIG. 2b, the printing ink layer 330 is not part of the value document substrate 300. The security element layer composite 200 is arranged directly on the value document substrate 300. After the arrangement of the security element layer assembly 200 on the value document substrate 300, the printing layer 330 is applied to the value document substrate 300 and the security element layer assembly 200 and thus also covers the security element layer assembly 200, but not the connection area between the security element layer assembly 200 and the value document substrate 300. Instead of or in addition to the printing layer 330, a color layer and / or lacquer layer and / or film can be arranged.

Accordingly, the excitation radiation of the first luminescent substances in the security element layer composite 200 only has to penetrate the value document substrate 300 in order to excite the first luminescent substances, and not the printing layer 330. Furthermore, emission radiation of the first luminescent substances only has to penetrate the value document substrate 300 in order to be applied by a detector the underside of the value document 30 and not the printing layer 330.

The security element layer composite 200 can be designed as shown in FIGS. 1 a and 1 b. However, emission radiation from the first luminescent substances does not penetrate the security element layer composite 200 in such a way that the emission radiation emerges from the upper side of the value document 30 and is detectable. FIG. 2c shows a value document that is similar to the value document from FIG. 2b. In contrast, the print layer 330 has a cutout on the upper side of the value document substrate 300 in the area of the security element layer composite 200. A print layer 330 is also arranged on the underside of the value document substrate 300 and partially overlaps with the security element layer composite 200 in transmitted light. Emission radiation and excitation radiation from the first luminescent substances must therefore penetrate the print layer 330 and the value document substrate layer 320 in some areas. The print layer 330 can accordingly weaken the excitation and emission of the first luminescent substances.

Figure 2d shows a value document that is similar to that of Figure 2c. In contrast, the document of value substrate 300 is thinned out, so that after the security element layer composite 200 has been applied, the maximum thickness of the document of value 30 does not increase too much. The thinning can essentially correspond to the thickness of the security element layer composite 200. Furthermore, the area of the underside of the value document that overlaps with the security element layer composite 200 in transmitted light was not additionally printed. Here, the excitation and emission radiation of the first luminescent substances only has to cross the thin value document substrate 300 and not a printing layer 330, so that in this case the highest luminescence intensity can be achieved.

The first luminescent substance is located in the security element layer composite 200, viewed from the top of the value document 30, preferably in one or more polymer layers below a reflective layer. The strong absorption or reflection of the reflective layer on the one hand means that the security element layer composite is read out 200 prevented from the top of the value document 30. On the other hand, the reflection of the excitation and emission radiation on its underside can produce an increase in the intensity of the first luminescent substances. B. scattered excitation radiation can hit the first luminescent substances several times.

FIGS. 3a and 3b show schematic representations of a test method for a value document according to the invention. The checking of a value document 30 is shown, which comprises a security element layer composite 200, which is arranged on a value document substrate 300. The security element layer composite 200 has an embossing lacquer layer 211 on which a reflective metallization 213 is applied. A luminescent substance layer 214 with first luminescent substances 240 is arranged under the embossing lacquer layer 211. The value document substrate 300 comprises a value document substrate layer 320, on which a print layer 330 is applied on both sides.

In the present case, the luminescence of the security element layer composite 200 or the first luminescent substances 240 contained in the security element layer composite 200 is not detected from the top of the value document 30, but from the underside thereof. An excitation radiation 410 from a sensor 50 passes through the print layer 330, the value document substrate layer 320, again another print layer 330, part of the security element layer composite 200 and reaches the luminescent substance layer 214, which contains the first luminescent substances 240, and excites them on. Furthermore, the excitation radiation 410 passes a further part of the security element layer composite 200, reaches the metallization 213 and is reflected back (or scattered) there, so that the excitation radiation 410 cannot penetrate the security element layer composite 200 and can emerge at the top.

Through multiple scattering and reflection, it is possible for the excitation radiation 410 to pass the part of the security element layer composite 200 containing the first luminescent substances 240 several times, so that the metallization 213, with a corresponding configuration, makes an important contribution to increasing the luminescence intensity of the security element layer composite 200 can deliver. This contribution of the excitation radiation 410 to the value document substrate layer 320, for example, obtained by multiple scattering and / or reflection, is symbolized schematically here by the arrows 440.

The emission radiation 430 from the first luminescent substances 240 is generally emitted in a non-directional manner in all spatial directions. The luminescent substances 240 excited to luminescence thus send back part of the emission radiation 430 directly (that is, they pass the same path as the excitation radiation 410). However, a considerably larger part only reaches sensor 50 after several scattering or reflection processes. For example, a further part of the emission radiation 430 reaches the metallization 214 and is reflected (or scattered) by it and can thus also contribute to the detected emission radiation 430 which is on the side of the value document 30 not carrying the security element layer composite 200, here on the lower printing layer 330, exits. The emission radiation 430 reaches sensor 50, which detects it.

The intensity of the emission radiation 430 detected at the sensor 50 is therefore highly dependent on various factors: the structure of the security element layer composite 200 (eg distance between first luminescent substances 240 and metallization 214),

- the scattering behavior of the individual layers,

the structure of the metallization 214 (alignment and mattness of the reflecting metal surfaces, the scattering behavior of the value document substrate layer 320, etc.),

FIG. 3 b shows the same value document 30 as in FIG. 3 a, but here the measurement is carried out from the other side of the value document 30. The excitation radiation 410 cannot penetrate the metallization 214, therefore the luminescent substances 240 are not excited and do not emit emission radiation.

In the application, it is possible that a small portion of the excitation _S adiation traverses the metallization 214 410, for example because it is not completely reflective and the luminescent substances are 240 thus excited to a part. However, the resulting emission radiation would have to penetrate the metallization 214 again, so that it is strongly weakened again. The emission radiation detectable by the sensor 50 would therefore be very low.

Claims

P a t e n t a n s r u c h e

1. Security transfer element for a document of value, comprising a security element layer composite and a carrier film detachably connected to the security element layer composite, the security element layer composite

has a functional layer which develops an optically variable effect for a viewer after being transferred to a value document;

has an adhesive layer;

has an upper side which, after the security element layer composite has been transferred to a value document substrate, faces the viewer, the adhesive layer being arranged on the side of the functional layer which is opposite the upper side; and

has at least one luminescent substance, the luminescent substance in the adhesive layer and / or is arranged in a luminescent _S chicht, wherein the adhesive layer and / or the Lumineszenzstoffschicht on the opposite side of the top of the functional layer in the composite disposed Sicherheitselementschicht- is;

characterized in that

the luminescent substance has primary emission radiation in the wavelength range between 700 nm and 2100 nm and can be excited by excitation radiation in the wavelength range between 400 nm and 2100 nm, in particular between 700 nm and 2100 nm; and the functional layer is opaque for the emission radiation of the luminescent substance.

2. Security transfer element according to claim 1, characterized in that the emission radiation of the luminescent substance of the security element layer composite in a wavelength range between 900 nm and 1300 nm, and / or 1300 nm and 1600 nm, and / or 1600 nm and 1850 nm and / or 1850 and is 2100 nm.

3. Security transfer element according to one of the preceding claims, characterized in that the luminescent substance of the security element layer composite has no human-visually recognizable additional anti-Stokes emission.

4. Security transfer element according to one of the preceding claims, characterized in that the luminescent substance of the security element layer composite comprises organic leachants, metal-organic complexes with in particular erbium, thulium, holmium, neodymium or ytterbium, and / or doped inorganic pigments with the dopants erbium, Thulium, holmium, neodymium or ytterbium or doped with transition metals, particularly preferably chromium, manganese and / or iron.

5. Security transfer element according to one of the preceding claims, characterized in that the at least one luminescent substance has a grain size (D99) of less than 15 gm, preferably less than 8 gm and more preferably less than 5 gm.

6. Security transfer element according to one of the preceding claims, characterized in that the functional layer is designed to be absorbent and / or reflective.

7. Security transfer element according to one of the preceding claims, characterized in that the functional layer comprises a metallic layer and / or a metallic coating, at least in some areas, preferably over the entire surface, preferably the metallic layer and / or the metallic coating on the side is formed of the functional layer which faces away from the viewer, or is formed on the side of the functional layer which faces the viewer.

8. Security transfer element according to one of the preceding claims, characterized in that the functional layer which unfolds the optically variable effect comprises a reflective embossed structure, in particular diffractive structure and / or a reflective microstructure, and / or transparent highly refractive layers, thin-layer elements with color shift effect, in particular with a reflective layer and a semitransparent layer and a dielectric layer arranged between them, layers of liquid-crystalline material, in particular of cholesteric liquid-crystal material, printing layers based on effect pigment compositions with an angle of view-dependent effect or with different colors has and / or has a multilayer structure, namely two semitransparent layers and a dielectric layer arranged between the two semitransparent layers.

9. Security transfer element according to one of the preceding claims, characterized in that the security element layer composite has a scattering layer with light-scattering properties, the scattering layer preferably being arranged adjacent to the luminescent substance and / or adjacent to the fuminescent substance layer; and / or is part of the functional layer.

10. Value document, comprising a flat value document substrate and a security element layer composite, wherein

the security element layer composite

o has a functional layer which, when viewed in incident light on an upper side of the functional layer, has an optically variable effect for an observer; o has an adhesive layer;

o has an upper side which, after the security element layer composite has been transferred to a value document substrate, faces the viewer, the adhesive layer being arranged on the side of the functional layer which is opposite the upper side; and

o has at least one first fuminescent substance, the first fuminescent substance being arranged in the adhesive layer and / or in a fuminescent substance layer which is arranged in the security element layer composite on the opposite side of the functional layer; and

the security element layer composite is arranged on an upper side of the value document substrate in such a way that the functional layer which unfolds the optically variable effect is oriented such that the optically variable effect in incident light is on an upper side of the Document of value is recognizable and the security element layer composite in incident light on an underside of the document of value, which lies opposite the top of the document of value, is at least partially covered by the document of value substrate;

characterized in that

the at least one first luminescent substance has primary emission radiation in the wavelength range between 700 nm and 2100 nm and can be excited by excitation radiation in the wavelength range between 400 nm and 2100 nm, in particular between 700 nm and 2100 nm; and the functional layer is opaque for the emission radiation of the luminescent substance.

11. Value document according to claim 10, characterized in that the intensity of the emission radiation of the at least one first luminescent substance of the security element layer composite is significantly higher on the underside than on the top of the value document, where preferably no emission radiation of the first luminescent substance the top exits.

12. A document of value according to one of claims 10 or 11, characterized in that the document of value substrate has at least one second luminescent substance.

13. A document of value according to one of claims 10 to 12, characterized in that the emission radiation of the first luminescent substance of the security element layer composite in a wavelength range between 900 nm and 1300 nm and / or 1300 nm and 1600 nm, and / or 1600 nm and 1850 nm and / or 1850 and 2100 nm.

14. A document of value according to one of claims 10 to 13, characterized in that the first luminescent substance of the security element layer composite has no additional anti-Stokes emission that is visually recognizable by humans.

15. Value document according to one of claims 10 to 14, characterized in that the first luminescent substance of the security element layer composite and / or the second luminescent substance of the value document substrate organic dyes, metal organic

Complexes comprising in particular erbium, thulium, holmium, neodymium or ytterbium, and / or doped inorganic pigments with the dopants erbium, thulium, holmium, neodymium or ytterbium or doped with transition metals, particularly preferably chromium, manganese and / or iron.

16. Value document according to one of claims 10 to 15, characterized in that the at least one first luminescent substance of the security element layer composite and / or the at least one second luminescent substance of the value document substrate has a grain size

(D99) of less than 15 gm, preferably less than 8 gm and more preferably less than 5 gm.

17. A document of value according to one of claims 10 to 16, characterized in that the functional layer is absorbent and / or reflective, in particular based on the emission radiation of the first luminescent substance.

18. A document of value according to one of claims 10 to 17, characterized in that the functional layer comprises, at least in regions, preferably over the entire surface, a metallic layer and / or a metallic coating, the metallic layer and / or the metallic coating preferably being on the Side of the functional layer is formed, which faces away from the viewer.

19. A document of value according to one of claims 10 to 18, characterized in that the functional layer which unfolds the optically variable effect comprises a reflective embossed structure, in particular a diffractive structure and / or a reflective microstructure, and / or transparent highly refractive layers , Thin-layer elements with a color shift effect, in particular with a reflective layer and a semitransparent layer and a dielectric layer arranged in between, layers of liquid-crystalline material, in particular made of cholesteric liquid-crystalline material, printing layers based on effect pigment compositions with a viewing angle-dependent effect or with has different colors and / or has a multilayer structure, namely two semitransparent layers and a dielectric layer arranged between the two semitransparent layers.

20. A document of value according to one of claims 10 to 19, characterized in that the security element layer composite has a scattering layer with light-scattering properties, the scattering layer preferably being arranged adjacent to the first luminescent substance and / or adjacent to the luminescent substance layer; and / or is part of the functional layer.

21. Value document according to one of claims 10 to 20, characterized in that the intensity of the emission radiation of the at least one first luminescent substance in incident light on the underside of the value document is more than 50% higher, preferably more than

80% higher, particularly preferably more than 100% higher, than in incident light on the top of the value document.

22. A value document according to one of claims 10 to 21, characterized in that the value document substrate comprises at least one layer of a paper substrate layer, the paper substrate layer comprising cellulose fiber and / or fillers, the fillers preferably titanium dioxide, organic auxiliaries, preferably car- are boxymethyl cellulose, and / or at least one plastic layer, preferably a polymer layer with preferably cellulose fiber and / or fillers, preferably titanium dioxide or carboxymethyl cellulose, and / or the document substrate of value contains a Kubelka-Munk scattering coefficient with a value between 10 and 80 V _mm in a wavelength range from 400 nm to 2100 nm.

23. A document of value according to one of claims 10 to 22, characterized in that the document of value substrate comprises at least one second luminescent substance, the emission wavelength region of the emission radiation and / or excitation wavelength region of the second luminescent substance essentially being the wavelength region of the emission radiation and corresponds to or excitation of the first luminescent substance of the security element layer composite, the first luminescent substance of the security element _S chichtverbunds and the second luminescent substance the Wertdoku- have ment substrate neszenzverhalten particularly a mutually complementary luminescence.

24. Document of value according to one of claims 10 to 23, characterized in that the first luminescent substance has a refractive index which is matched to the refractive index of the material surrounding the first luminescent substance, the refractive index of the first luminescent substance preferably equaling the refractive index of the the first material surrounding the luminescent material.

25. A method for checking a value document according to one of claims 10 to 24, with the following steps:

Applying the value document with an excitation light on the _S adiation to the underside of the document of value, wherein the presence excitation radiation the wavelength range for excitation of the luminescent substance of the security element ERS th layer composite to summarizes;

Detecting an emission, in particular a response and / or a decay behavior of the emission radiation, of the first luminescent substance of the security element layer composite on the underside of the value document over at least an area of the value document; and

Determining the authenticity of the security element layer composite from the detected emission, in particular from the response and / or decay behavior of the detected emission radiation.

26. The method according to claim 25, characterized in that the area of the document of value covers the area of the security element. _S Layer composite and preferably a surrounding area of the security element layer composite, which has an area of at least 100% of the area of the security element layer composite.

27. The method according to any one of claims 25 or 26, characterized in that the detected emission, in particular the detected attack and / or the decay behavior, results in a preferably two-dimensional pattern over the surface area, and the pattern corresponds to the type of Corresponds to the security element layer composite.

28. The method according to any one of claims 25 to 27, characterized by the further steps:

- Exposing the document of value with an excitation radiation in incident light onto the top of the document of value, the excitation radiation encompassing the wavelength range for excitation of the first luminescent substance of the security element layer composite;

- Detecting an emission, in particular a response and / or a decay behavior of the emission radiation, of the first luminescent substance of the security element layer composite at the top of the document of value over at least an area of the document of value; and

- Compare those detected on the top of the value document

Emission with the emission detected on the underside of the value document for checking the authenticity of the value document.

29. Test unit (50) for checking documents of value, with an excitation device for subjecting the respective document of value to an excitation radiation in incident light on the underside of the document of value, the excitation radiation comprising the wavelength range for excitation of the first luminescent substance of the security element layer composite of the document of value;

a detecting means for detecting an emission, in particular a Ankling- and / or a decay behavior of the emission radiation of the first luminescent substance the security- selementschicht _V erbunds at the bottom of each document of value over at least an area of the respective document of value; and

an evaluation device for checking the authenticity of the respective value document on the basis of the detected emission, in particular on the basis of the response and / or decay behavior of the detected emission radiation,

wherein the test unit (50) is designed to carry out the method according to one of claims 25 to 28.

30. A value document processing device for checking value documents, comprising an interface for feeding value documents, at least one checking unit (50) according to claim 29 for checking the value documents and an output unit for outputting the value documents.

31. System comprehensive

a test unit according to claim 29 and / or a value document processing device according to claim 30 and - A security transfer element according to one of claims 1 to 9 and / or a value document according to one of claims 10 to 24.

32. Method for checking a value document, the value document having a value document substrate and a security element and the security element for an observer in incident light on an upper side of the value document having an optically variable effect at least in some areas, and the value document having at least one luminescent substance, preferably the luminescent substance has primary emission radiation in the wavelength range between 700 nm and 2100 nm and can preferably be excited by excitation radiation in the wavelength range between 400 nm and 2100 nm, in particular between 700 nm and 2100 nm; wherein the security element in incident light on the top of the value document partially or completely covers the luminescent substance, the value document being designed such that emission radiation from the luminescent substance to the top of the value document in the areas in which the security element in incident light is on the top side of the document of value covering the luminescent substance is prevented; with the steps:

Applying the value document with an excitation _S adiation in reflected light on a bottom surface of the value document, wherein the excitation radiation comprises the wavelength range for excitation of the luminescent substance of the document of value;

Detecting an emission, in particular a response and / or a decay behavior of the emission radiation, of the luminescent substance on the underside of the value document over at least one area of the value document; and Determining the authenticity of the value document from the detected emission, in particular from the response and / or the decay behavior.