EP2953799B1 - Security feature for a value or security product and method for producing this security feature - Google Patents

Description

The present invention relates to a value or security product, as well as a method for producing the value or security product. A value or security document can be, for example, a means of payment, in particular a banknote, or another value document or else a personal document, in particular a passport. The documents can basically consist of paper, another fiber felt or cardboard or in principle also of an organic polymer, ceramic material, glass or of metal or contain this. Cards and card-shaped components of book-type documents may preferably be made of laminated polymer films. To test the authenticity and / or coding of information, these products have the security features according to the invention.

The security features used in the value or security products can only serve to prove the authenticity of the products, regardless of their nature or by their user. Such security features are, for example, guilloches, watermarks, embossing prints, tipping pictures, holograms, the special paper of banknotes and the like. Personalizing, for example personalizing, security features also contain in coded form or in plain text information about the type of document, about its owner and / or about an object to which the document is assigned. Such information may include a face image / portrait (for example in the form of a photograph) of the owner, his or her personal data such as name, date of birth, place of birth, signature, a personal identifier such as a membership number, or biometric data of the holder, such as fingerprints. Iris and retina detection. Another security feature that individualizes the document can be, for example, a serial number of the document or the chassis number of a motor vehicle to which the document is assigned.

In DD 301 115 A7 a tamper-proof paper is described which contains at least one type of regularly and / or arbitrarily designed, regularly and / or placed distributed or arranged special planchettes. This restricts or prevents the misuse of the special paper. In addition, it is stated in one exemplary embodiment that the substance-water mixture for producing the paper contains, in addition to the planchettes, UV-activatable mottling fibers. Furthermore, it is known that security papers contain security threads.

In Patent Abstracts of Japan too JP 2007-203568 a display is shown, which is formed from planar Lichtleitstrukturen. These light guide structures are provided with a diffraction grating or hologram having a surface relief, so that the light guided by the light guide structures is radiated from the diffraction grating or hologram.

In US 2004/0229022 A1 there is provided a security device having reflective layers and indicia having further layers which are layers in a laminate. Between the reflecting layers is a photoconductive layer. Holes can be introduced into the reflective layers. Light introduced through the holes is emitted.

In DE 10 2008 033 716 B3 there is disclosed a value or security document in which a light guiding structure for guiding light in a plane is substantially parallel to the top of the document. The light is decoupled from the light guide structures to local modifications and is thus visible on a surface. For example, light coupled in via the side edge of the document may exit at the surface via these modifications. The modifications are produced in the form of recesses in boundary layers, which delimit the light-guiding structures.

In CH 677 905 A5 a method for producing a multi-layered ID card is described. The card is made up of several film layers which are printed using different printing technologies. The cover films, the base films and other films are printed both digitally and by means of conventional printing processes. The base film is made of plastic and can be formed in two layers with fiber optics embedded therein. The faces of the light guide lie on the edges of the card and allow the input or

Decoupling of light by means of appropriate readers. Thus, a personal arrangement of the optical fibers can be read by machine.

US 5,881,196 A discloses a value or security product according to the preamble of claim 1. There is a constant need for novel, in particular individualizing security features that are secured against forgery and / or falsification and / or copy and, for example, to assign the information encoded therewith to the Type of value or security product are easily recognizable by a person. Preferably, the security feature should be located in a secure counterfeiting and / or falsification and / or copy of the inner product layer. The present invention is also based on the essential further object of providing a cost-effective, simple and quickly realizable, in particular individualizing, security feature. Another object of the present invention is to provide a security paper that is impossible or extremely difficult to falsify.

Insofar as in the description and in the claims of the present application the term 'value or security product', which can be in particular a security or security document or a security element designed in particular as a transfer element, is used, a means of payment, such as a banknote, is particularly preferred. or any other value document, such as a security, such as a check, or a visa page in a passport, bill of lading, tax stamp, postage stamp, ticket, or the like. It may, however, also be a passport, identity card, driver's license or other ID card or access control card, vehicle registration document, vehicle registration document, visa, check,
Bank, credit or debit card, loyalty card, health card, chip card, company card, credential, membership card, gift or purchase voucher or other credential, a token, adhesive tag (for example, for product security) or other such document. A product according to the invention may also be a security element, for example a sticker, label or the like, which has the security feature according to the invention and which can be permanently connected to a precursor of a value and / or security document in order to form the value and / or security document (transfer member). The product may be, for example, a smart card. The security or security document may be in a banknote format or in the ID 1, ID 2, ID 3 format or any other format, such as a booklet or brochure form, such as a passport-like item. A value or Security product can also be a laminate of several document layers, which are connected register-accurate under heat and under increased pressure. These products should meet the standardized requirements, for example ISO 10373, ISO / IEC 7810, ISO 14443. The product layers consist, for example, of a carrier material which is suitable for lamination.

The value or security product is preferably formed from a fiber felt, for example from paper or cardboard. For the production of these materials in particular a fiber mass, especially of cotton, wood, rags, flax, jute, straw or the like is used. Furthermore, the value or security product can also be produced from other fiber materials, for example from mineral fibers, such as spun glass or rock wool, animal fibers, such as wool, leather or silk, or from polymer fibers or from mixtures of these materials. However, it can also be formed from a non-fibrous material, in particular from polymer, glass, metal or ceramic. The polymer of the fibrous or non-fibrous material may be selected from a group comprising polycarbonate (PC), especially bisphenol A polycarbonate, polyethylene terephthalate (PET), their derivatives such as glycol modified PET (PETG), polyethylene naphthalate (PEN), polyvinyl chloride (PEN). PVC), polyvinyl butyral (PVB), polymethyl methacrylate (PMMA), polyimide (PI), polyvinyl alcohol (PVA), polystyrene (PS), polyvinylphenol (PVP), polypropylene (PP), polyethylene (PE), thermoplastic elastomers (TPE), in particular thermoplastic polyurethane (TPU), acrylonitrile-butadiene-styrene copolymer (ABS) and their derivatives. Preferred polymers are PC and PC / TPU / PC. The polymers may be either filled or unfilled. In the latter case they are preferably transparent or translucent. If the polymers are filled, they are opaque. The product can be made of several of the aforementioned materials.

Insofar as the term 'security feature' is mentioned in the description and in the claims of the present application, this is to be understood as meaning a feature which preferably causes an optical impression which can be recognized by means of optical recognition methods. The visual impression is generated by light emission in the form of an optically perceptible design. This design preferably includes an individualizing information. The security feature may be configured to be directly perceived by a user, or it may be a machine-readable feature. In the latter case, the security feature is detected by means of, for example, electromagnetic radiation, spatially resolved receiving device and perceived by a viewer or evaluated by means of a further device provided for this purpose. The security feature can be manufactured as part of a value or security document or as a separate product (security element). The latter can be glued to the document, for example. The security feature will generally only occupy part of the surface of the document.

According to a first aspect of the present invention, the objects are achieved by a value or security product according to claim 1. The security feature is formed by at least one Lichtleitstruktur that at least partially passes through a product layer. This can already be the value or security product itself or merely a part of the value or security product. The product layer has a front and a rear main surface. The at least one light guide structure has in each case a first end face for a light entrance and a second end face for a light exit. All end faces of the at least one light guide structure are located in the region of one of the main surfaces. The light guiding structure is formed by a material strand section.

1. (a) Ausbilden eines eine vordere und eine hintere Hauptfläche aufweisenden Filmes eines zur Bildung der Produktlage geeigneten Vormaterials;
2. (b) Einbringen eines Materialstranges in den Film des Vormaterials, sodass mindestens ein erster Abschnitt des Materialstranges innerhalb des Filmes des Vormaterials und mindestens ein zweiter Abschnitt des Materialstranges außerhalb des Filmes des Vormaterials verlaufen und sodass der Materialstrang zwischen dem mindestens einen ersten Abschnitt und dem mindestens einen zweiten Abschnitt durch mindestens eine der Hauptflächen des Filmes hindurchtritt;
3. (c) Umwandeln des Filmes des Vormaterials unter Bildung der Produktlage, wobei der Materialstrang für die Bildung mindestens einer Lichtleitstruktur in der Produktlage fixiert wird; und
4. (d) Entfernen des mindestens einen außerhalb der Produktlage verlaufenden zweiten Abschnittes des Materialstranges, beispielsweise durch Abscheren, sodass die mindestens eine Lichtleitstruktur in Form des mindestens einen ersten Abschnittes des Materialstranges entsteht.

According to a second aspect of the present invention, the objects are also achieved by a method according to claim 8. This process comprises the following process steps:

1. (A) forming a front and a back main surface having a film of a suitable material for forming the product layer;
2. (B) introducing a strand of material in the film of the starting material, so that at least a first portion of the material strand within the film of the starting material and at least a second portion of the material strand outside of the film of the starting material and run so that the strand of material between the at least one first portion and the at least a second portion passes through at least one of the major surfaces of the film;
3. (c) converting the film of the primary material to form the product layer, wherein the strand of material for the formation of at least one Lichtleitstruktur is fixed in the product layer; and
4. (d) removing the at least one second section of the material strand running outside the product layer, for example by shearing, so that the at least one light guide structure is formed in the form of the at least one first section of the material strand.

By forming the light guide structure in the form of a material strand section, it is firstly very easy to form the light guide structure in the product layer, so that the production of the product layer with the light guide structures can be made extremely simple and cost-effective. In particular, no elaborate production methods, such as laser ablation, such as in DE 10 2008 033 716 B3 , required. Furthermore, it is also advantageous to arrange the end faces of the light guide structures in the region of one or both main surfaces of the product layer, because the value or security product thereby receives a design serving as a security feature, which can be easily perceived by a viewer. In addition, the arrangement of the end faces of the light guide structures on the surfaces of the product layer also allows a variety of design options that are not given in their arrangement on the side edge. With the in CH 677 905 A5 Accordingly, there are only a few spatial possibilities of the arrangement for the light input and output. In addition, verification in this case is usefully made by machine; Verification with the naked eye is not readily feasible.

In a first embodiment variant of the present invention, a first end face of the at least one light guide structure, for example for light entry, in the region of a first main surface of the product layer and a second end face of this light guide structure, for example for the light exit, can be in the region of a second main surface of the product layer ( two-sided embodiment, see-through feature). In a second embodiment variant, both end faces of the at least one light guide structure can be located in the region of only one of the two main surfaces of the product layer (one-sided embodiment). Thus, on one side of the valuable or security product, electromagnetic radiation entering the optical waveguide structure can emerge again either on the opposite side or on the same side. The electromagnetic radiation used is preferably radiation in the visible spectral range, ie in a spectral range from about 400 nm to about 750 nm. It may alternatively be UV radiation or IR radiation. It is advantageous if the electromagnetic radiation used is not substantially absorbed in the light guide structures.

By means of the light guide structures, an optically perceptible security feature is created whose imitation or counterfeiting is extremely complex. This safety feature consists in the delocalized electromagnetic radiation in the light guide structures being delocalized into the light guide structures via an end face in the region of one of the main surfaces of the product layer to the opposite end face in the region of one of the main surfaces of the product layer, where it exits again. The incoming electromagnetic radiation comes either from daylight or from an artificial light source, such as an LED. The electromagnetic radiation enters, for example, from the front or from the back of the product layer in the Lichtleitstrukturen. At the end faces of the light guide structures, at which electromagnetic radiation emerges, a viewer can perceive the exiting electromagnetic radiation. The same applies to a machine reader. The assignment made in this patent application of the end faces as Lichteintritts- or light exit surfaces results in the application when light falls on the faces and enters there and exits at the other end faces again.

In a preferred embodiment of the present invention, the at least one light guide structure is formed from a polymer material. The polymer may be one of the polymer materials which are also suitable for the formation of the value or security product itself and from which, for example, the product layer may also be formed. The strand of material can be supplied as a thread, yarn, fiber or fiber bundles or the like from a donor to the precursor. For example, the material strand may be stored. In this case, the dispenser is for example a dispenser. Or, the strand can be made, such as by spinning, extruding, or other strand forming technique, just prior to incorporation into the starting material. In this case, the dispenser is, for example, an extrusion nozzle or a spinneret. Alternatively, the Lichtleitstruktur may also be present as a glass fiber. This is preferably stored and fed from the supply to the precursor.

In a further preferred development of the present invention, the light guide structures present in the form of material strand sections are formed by a transparent material having a first refractive index and enclosed by a second material which has a first refractive index second refractive index, which is lower than the first refractive index. The second material may be transparent, translucent or opaque. The refractive indices are respectively defined with respect to the wavelength of the electromagnetic radiation used. As a result of the configuration formed by a material strand section and the second material surrounding it, the electromagnetic radiation in the light guide structures is passed on virtually without attenuation by totally reflecting the radiation at the interface between the material strand section and the second material. For this purpose, the second material can be formed in any desired shape, as long as it encloses the material strand almost completely (over> 90% of the surface of the material strand section), better still completely. For this purpose, the second material may be formed, for example, in the manner of a jacket or an envelope, for example in the form of a tube. In principle, however, the second material may also represent an embedding material for the material strand section, for example by the product layer itself forming the second material surrounding the light guide structure, provided that the product layer is formed by a homogeneous medium. Air is particularly suitable as a second material because of its very low refractive index. In the case of a fiber felt for the product layer forming potting material, air eventually fills in spaces between the fibers and forms the second material.
The second material surrounding the material strand section may preferably be formed from a polymer, in particular from one of the polymers which are also indicated for the formation of the valuable or security product.

In the present invention, the at least one light guiding structure is held in the product layer by means of an adhesion layer. Preferably, the adhesion layer is formed by a hot-melt adhesive. For example, the hot-melt adhesive has a softening temperature of 50 to 200 ° C, preferably from 80 to 120 ° C, on. After converting the film from the primary material to the (solidified) product layer, the hot-melt adhesive unfolds its adhesive properties and anchors the optical fiber structure in the product layer as the product layer is heated along with the optical fiber structure, thereby softening the hot-melt adhesive. Alternatively, the adhesion layer can also be formed by a UV-curable adhesive. For curing and for bonding the Lichtleitstruktur with the material of the product layer, this is preferably exposed in this case after their production UV radiation to cure the adhesive. The adhesion layer preferably has a second refractive index at one of the wavelengths of the electromagnetic radiation used which is smaller than the first refractive index of the material strand section. Thus, the adhesion layer forms the second material surrounding the material strand section, which causes total reflection of the electromagnetic radiation in the material strand section.

In a further preferred development of the present invention, the at least one light guide structure contains at least one material absorbing in the visible spectral range, so that white radiation which has entered the light guide structure appears colored. An absorbing material of the light guiding structure can be provided in particular by one or more absorptive dyes which are introduced into the material of the light guiding structure. For example, either a single absorptive dye with a given absorption and reflectance spectrum or a mixture of several absorptive dyes can be used, each having an individual absorption and remission spectrum and in the mixture have a different absorption and remission spectrum of the individual absorptive dyes, which results subtractive from the spectra of the individual absorptive dyes. The absorptive dyes may be inorganic or organic compounds. Organic absorptive dyes may typically be azo compounds. Although the absorptive dyes absorb electromagnetic radiation conducted through the optical waveguide structure, they do not scatter or substantially scatter them, so that the radiation in the optical waveguide structures is preferably not substantially or not substantially attenuated.

In a further preferred development of the present invention, the at least one optical waveguide structure additionally or alternatively to the absorptive dyes contains at least one luminescent material in the visible spectral range, such that the optical waveguide structure luminesces when irradiated with excitation radiation (photoluminescence, both Stokes and anti-Stokes -Shift). In principle, of course, other luminescence mechanisms are also conceivable, such as electroluminescence, the luminescent structure luminescing in the light guide structure when generating an electrostatic field. The excitation radiation for the luminescence is preferably UV radiation (UVA, UVB or UVC radiation), but may also be IR or visible radiation. A luminescent material of the optical waveguide structure can in particular be provided by one or more luminescent substances which are introduced into the material of the optical waveguide structure. The at least one luminescent substance can, for example, luminesce broadband or narrow band in the visible spectral range. If the spectral distribution of the luminescence in this area is not uniform, the emitted light is also colored. The luminescent substance as well as the absorptive dye be organic or inorganic. Typical luminescent substances are, for example, in US 3,474,027 A . DE 198 60 093 A and DE 10 2007 035 592 A1 , the disclosure of which is incorporated in the present application. These are host lattices which are doped with rare earths as luminophores, in particular substances doped with terbium, cerium and / or europium, for example oxysulphides and oxynitrides. In principle, it is also possible to use calcium phosphates, zinc silicates, strontium phosphates, alkaline earth silicates, silicates and rare earth aluminates, alkaline earth metal tungstates, zinc oxides, zinc sulfides and rare earth oxides which are labeled with Eu ²⁺ , Eu ³⁺ , Sb ³⁺ , Mn ²⁺ , Ag ⁺ , Cu ⁺ , Sn ²⁺ or Tb ³⁺ . The pigments formed herewith can additionally be coated with organic substances in order to increase the quantum yield of the luminescence. Furthermore, quantum dots can also be used, ie semiconductor particles whose size is in the nm range, for example based on CdS. Furthermore, organic luminescent substances are also usable, such as rhodamine 6G or fluorescein. The luminescent substances do not scatter the electromagnetic radiation transmitted through the optical waveguide structure or do not significantly, so that the radiation in the optical waveguide structures is preferably not appreciably or not substantially attenuated.

The absorptive dyes and the luminescent substances can be used individually or combined in a light-guiding structure. If several optical waveguide structures are present, they may contain an absorptive dye and / or a luminescent substance or different absorptive dyes and / or luminescent substances. In the latter case, the distribution of the color (including the specific absorption in spectral regions other than in the visible spectral range) and / or the spectral difference of the luminescence between the optical waveguides can represent another security feature that can also encode information.

The light guide structures can be located in any position in the product layer. The light guiding structures are preferably by short, for example from 100 .mu.m to 10 mm, more preferably from 200 .mu.m to 5 mm, even more preferably from 300 .mu.m to 2 mm, even more preferably from 400 .mu.m to 1000 .mu.m and most preferably from 500 .mu.m formed up to 800 microns, long material strand sections, which most preferably do not branch, but extend exclusively from a light entrance end face to a light exit end face. The material strand sections preferably have a round, very particularly preferably a circular, cross-section. The diameter of such material strand sections can For example, in the range of 10 .mu.m to 500 .mu.m, preferably from 30 .mu.m to 150 .mu.m and most preferably from 40 to 100 .mu.m, are. The cross section may also be oval, quadrangular, in particular square or rectangular, or polygonal. If it is rectangular, the material strand sections can be flat strips. The cross section of the material strand sections can be in particular in the range of 1600 to 10,000 μm ² . The material strand sections may be arranged regularly or irregularly in the product layer. The material strand sections can traverse the product layer (see-through feature), for example in a straight track in a direction perpendicular to their main surfaces, so that in each case one end face of the material strand sections lies in the region of one of the two main surfaces. However, the material strand sections can also pass through the product layer in a curved track, which connects the two main surfaces of the product layer. In the latter cases, the end faces are therefore arranged, when viewing the product layer, either exactly perpendicular to the main surfaces one above the other or offset from one another.

In a particularly preferred development of the present invention, at least two light-guiding structures are arranged one behind the other in a production direction of the material of the product layer in the product layer. For example, the material of the product layer may be a fiber felt material, in particular a paper. In this case, the paper is typically produced in a rotary screen paper machine as a continuous paper web. During production, the production process results in a production direction in which the paper web is produced. In the same way, it is also possible to produce a continuous polymer film web in an extruder, which likewise results in a production direction in which the at least two light guiding structures are arranged running one behind the other. In the production of the continuous web, the light guiding structures are produced in the resulting continuous web. In this case, the material strand sections of these light guide structures preferably extend in each case from one main surface to another and pass through the product layer for this purpose. Alternatively, the material strand sections can only partially pass through the product layer, so that all end faces are located only in the region of one of the main surfaces. If a plurality of such arranged Lichtleitstrukturen are arranged in these variants, this results in lines on the product layer lying end faces of the material strand sections. In still further embodiments, the end faces of the material strand sections may be arranged in a predetermined dot pattern on one or both main surfaces of the product layer. The dot pattern can be formed in a somewhat shaped distribution of the end faces on one or both main surfaces of the product layer, which, for example, is a self-contained representation result, in particular an image, picture element, character, especially an alphanumeric character, a symbol, coat of arms, a line or other simple geometric shape, such as a formula, or the like. In this respect, the dot pattern may contain information, for example the denomination of the banknote provided therewith, and thus in particular also individualizing information. The dot pattern is preferably formed exclusively by the exit surfaces of the material strand sections.

In a further preferred development of the present invention, the product layer is formed at least substantially from a fiber felt. For example, the fiber felt fabric may be formed from paper or paperboard or from another fiber mass. In particular, vegetable fibers, especially fibers of cotton, wood, rags, flax, jute, straw or the like are used. In principle, mineral fibers such as spun glass or rock wool, animal fibers, such as wool, leather or silk, or polymer fibers in question.

For the production of a product layer provided with light guiding structures in the form of material strand sections, a precursor is first formed from a starting material, for example a film of fibrous materials which are skimmed off from a paper fiber slurry by means of a round or wire sieve, or a soft polymer film in an extruder, where the film forms. The product layer is then formed from the film by conversion, for example by dewatering the fiber film, so that the fiber felt thickens, or the polymer film solidifies.

Prior to this conversion, the material strand is introduced into the precursor, for example, the fibrous film located on the sieve or a still soft polymer film, for example by pressing the material strand into the precursor. For this purpose, preferably a material strand is used, which has a multiple of the length of the material strand sections contained in the finished product layer. This material strand can be produced, for example, immediately before introduction into the precursor by means of an extrusion die, so that the material of the strand is still bendable and soft. In order to introduce the material strand into the precursor, so that it is predominantly within the precursor, mechanical means can be used which selectively push the material strand locally, ie at defined locations along the strand of material, into the material of the precursor and optionally through it , For example, a profiling or embossing agent, for example a comb may be used which pushes and / or pushes the strand of material into the material by means of its teeth, the intervening sections of the strand of material extending at least partially within the precursor. As an alternative to a comb, it is also possible to use a contouring roller, by means of which the leading edge of the material strand is selectively penetrated into the precursor and / or pressed through it. With a guide of the material strand along one of the major surfaces of the precursor and application of a contouring roller with uniform teeth a wavy strand is obtained, which occurs on the voltage applied to the contouring roller side of the film at regular intervals through the main surface to the outside and otherwise either completely runs within the film or sections within the film and sections also exits from the film on the opposite side to the contouring. The contouring roller may also have a non-uniformly arranged toothing with not equiangularly arranged nose strips, so that the material strand is pressed in unevenly spaced locations in the film. Alternatively, it is also possible to use a planar stamp with embossing elements which are evenly or non-uniformly spaced from each other, with whose profiling the material strand is pressed into the film. The profiling of this stamp can be designed in the form of a pattern, so that the end faces are arranged in the form of this pattern, in particular if several strands of material are introduced in a planar manner next to one another.

When converting the precursor into the product layer, the material strand is fixed in position in the starting material. After conversion, the outer sections of the material strand are removed, for example by shearing, so that isolated material strand sections of the light guide structures form within the product layer. Their end surfaces are formed when removing the outer sections of the material strand, for example as cutting or shear surfaces, preferably flush with the corresponding main surface of the product layer. In particular, when shearing with a tool suitable for this end surfaces are generated, which are substantially aligned with the main surfaces. The projecting sections of the material strand can be sheared off, for example, with doctor blades which operate at a shallow angle (<45 °, preferably <25 °, even more preferably <20 °) against the surface of the product layer.

The above explanation for the production of the light guide structures is analogous to the introduction of several strands of material in the Vormaterialfilm, the deformation and solidification apply these strands of material as well as the removal of the outer portions of these strands, resulting in a variety of Lichtleitstrukturen. From each of the strands of material at least one Lichtleitstruktur is formed.

It is particularly preferred when a fiber slurry used for the production of banknotes or other security or security papers, for example a slurry of paper fibers, in particular cotton fibers, is fed to a multibox paper machine for producing a continuous paper web (by scooping the slurry). As a result, a fiber film is formed. During the removal of the liquid, in particular of water, from the paper pulp adhering to the round or wire mesh, a strand of material or even several strands of material guided in parallel, for example, parallel to the running direction of the paper material in the paper machine, is fed into the film of the pulp adhering to the sieve , For this purpose, for example, a polymer is dispensed from an extrusion nozzle, or an already produced material strand provided by a dispenser, for example a glass fiber. Other donors are also possible. The material strand is preferably enveloped by a hot-melt adhesive, which has a lower refractive index than the material of the material strand. By means of a spatially subordinate contouring roller or other profiling or embossing means, the material strand is punctually inserted at regular intervals in the paper pulp and optionally pushed through it. With appropriate adjustment of the manufacturing parameters (paper machine speed, feed rate of the material strand, positioning of the contouring roller over the surface of the screen) portions of the material strand remain between depressed sections above the pulp and other portions below the pulp so that they sag after the paper has dried protruding either side outside, or the material strand is completely pressed into the paper pulp, so that only the rearwardly projecting portions protrude outward. Alternatively, the material strand can also only partially be pressed into the paper pulp, in which case portions of the strand project above the pulp fiber pulp. Of course, this procedure is also possible with other fiber felts or with molten polymer or other materials. The hot-melt adhesive is then melted in the dryer section of the paper machine so that the strand of material is fixed in the paper. Thereafter, the protruding portions of the material strand are sheared off by means of sharp knives. As a result, small portions of the strand or strands of material remain in the paper material, which are located entirely within the material and their end faces in the area of or on the main surfaces of the paper. When drying the Faserbreifilmes the Faserfilzstoff, which forms the product layer forms. If necessary, the material must be cut to the required size.

If the product layer is not produced as a paper layer or in the form of another fiber felt, but in the form of a polymer film, the polymer material used for this purpose can be converted into the film form, for example by extrusion. The strand of material in this case is provided as described above, for example by extruding from a die just prior to introduction into the still soft polymer or by providing a stockpiled strand of material, for example a glass fiber. The material strand is introduced or inserted into the still soft polymer material and then deformed by pressing into the polymer material. Finally, protruding portions of the strand of material are removed.

Optionally, the material strand is wrapped in the production variants described above with an adhesive, in particular a hot-melt adhesive. The adhesive is UV cured, if it is a UV curable adhesive, or heated to soften it, after the introduction of the strand of material into the input material, deformation of the strand of material, and during or after converting the primary material to form the product layer if it is a hot-melt adhesive, so that the material strand firmly bonds with the surrounding material of the product layer.

The material strand can also be initially stored in the embodiments described above for the production of the product layer and, for example, kept in a roll. To produce the product layer, the material strand can be fed to the precursor, for example, from a dispenser and deformed therein.

The material of the product layer is preferably opaque or alternatively transparent or translucent, the material in the latter cases being able to partially absorb the electromagnetic radiation used. In these cases, the electromagnetic radiation emitted by the optical waveguides is visually easily recognizable because a contrast of the light exit surfaces of the optical waveguides to the surrounding material results.

The product layer into which the light guiding structures are incorporated may be part of the valuable or security product or may itself form the value or security product. For example, it is a single product layer that is stacked with other product layers into a stack and then bonded to these other layers, for example, in a lamination process, to form the security or security document. Alternatively or additionally, the product layer provided with the light-guiding structures can additionally be coated with a protective lacquer, so that the security feature lies inside the finished product and thus can not be readily manipulated by a third party. In these cases, outer layers and / or layers which cover the product layer provided with the light guide structures are to be made transparent or at least translucent so that the optical perception content generated by the light guide structures can be detected by a viewer or a machine.

For the verification of the value or security product, this can either be readily considered by a viewer under daylight conditions or under illumination with artificial light by the light falls, for example on the back of the product and enters there through the end faces in the material strand sections of the light guide structures. The viewer looks at the opposite side of the value or security product, where the other end faces of the light guide structures are located. The transmitted light is visible at these faces. With a corresponding spatial arrangement of the light exit surfaces of the light guide structures, the viewer can use this arrangement as a verification feature. If the optical waveguides only partially cross the product layer and their end faces lie in the region of only one major surface of the product layer, mechanical verification is advantageous, since in this case a spatially limited irradiation in the region of the light entry surfaces of the optical waveguides is required and at the same time the spatially limited radiation of passed electromagnetic radiation must be detected by the light exit surfaces. For example, the value or security product can be scanned successively, wherein the light exit surfaces of the light guide structures are detected gradually.

The security and / or security product can have, in addition to the security feature according to the invention, further security features, for example guilloches, micro-writing, holograms, kinegrams and the like. Furthermore, a value or security document can also have electronic components, for example an RFID circuit with antenna and RFID microchip, electronic display elements, LEDs, touch-sensitive sensors, and the like. For example, the electronic components may be hidden between two opaque layers of the document.

Fig. 1

zeigt eine Banknote mit dem erfindungsgemäßen Sicherheitsmerkmal in der Draufsicht in einer schematischen Darstellung in einer ersten Ausführungsform;

Fig. 2

zeigt zwei Varianten einer die Banknote durchquerenden Lichtleitstruktur im Querschnitt in einer schematischen Darstellung; (A) mit beiden an einer der Hauptflächen der Banknote befindlichen Stirnflächen der Lichtleitstruktur; (B) mit an jeweils einer der Hauptflächen der Banknote befindlichen Stirnflächen der Lichtleitstruktur; (C) schematische Schnittdarstellung durch einen Materialstrangabschnitt mit einer Hot-Melt-Kleberumhüllung;

Fig. 3

zeigt eine Banknote mit dem erfindungsgemäßen Sicherheitsmerkmal in der Draufsicht in einer schematischen Darstellung in einer zweiten Ausführungsform;

Fig. 4

zeigt ein Verfahren zur Einbringung eines Materialstranges in einen auf einem Rundsieb einer Papiermaschine abgeschöpften Papierfaserbrei, die Formung des Materialstranges und das Abscheren einseitig außenliegender Abschnitte des Materialstranges in einer Seitenansicht in einer schematischen Darstellung in einer ersten Ausführungsform;

Fig. 5

zeigt ein Verfahren zur Einbringung eines Materialstranges in einen auf einem Rundsieb einer Papiermaschine abgeschöpften Papierfaserbrei und das Abscheren beidseitig außenliegender Abschnitte des Materialstranges in einer Seitenansicht in einer schematischen Darstellung in einer zweiten Ausführungsform;

Fig. 6

zeigt eine Anordnung zur Verifizierung einer Banknote, die ein erfindungsgemäßes Sicherheitsmerkmal aufweist; (A) in einer perspektivischen schematischen Darstellung; (B) in einer schematischen Schnittdarstellung.

For a more detailed explanation of the present invention, the figures described below, which illustrate the invention by way of example, without affecting the scope of the invention serve:

Fig. 1

shows a banknote with the security feature according to the invention in plan view in a schematic representation in a first embodiment;

Fig. 2

shows two variants of the banknote crossing light guide structure in cross section in a schematic representation; (A) with both located on one of the main surfaces of the bill end faces of the Lichtleitstruktur; (B) with located on each one of the main surfaces of the bill end faces of the Lichtleitstruktur; (C) is a schematic sectional view through a strand of material with a hot-melt adhesive sheath;

Fig. 3

shows a banknote with the security feature according to the invention in plan view in a schematic representation in a second embodiment;

Fig. 4

shows a method for introducing a material strand into a Papierfaserbrei skimmed on a round screen of a paper machine, the shaping of the material strand and shearing one-sided outboard sections of the material strand in a side view in a schematic representation in a first embodiment;

Fig. 5

shows a method for introducing a material strand into a paper pulp skimmed on a round screen of a paper machine and shearing both sides of external sections of the material strand in a side view in a schematic representation in a second embodiment;

Fig. 6

shows an arrangement for verifying a banknote having a security feature according to the invention; (A) in a perspective schematic representation; (B) in a schematic sectional view.

In the figures, like reference numerals designate elements having the same function or elements.

In the Fig. 1 illustrated banknote 100 is made of a fiber felt fabric. The paper of this material is recovered in a conventional manner from a fiber-water slurry in a paper machine with a round screen as continuous material. The fiber material is preferably made of cotton. According to the invention, the banknote forms a product layer 105 which can be separated from a paper web 500 by singulation, for example cutting or punching. Fig. 4, 5 ) is formed.

The banknote 100 has a front main surface 101 and a rear main surface 103 ( Fig. 2A, 2B ). In the left margin 102 of the bill there is a watermark 130 which has been conventionally created in the papermaking process. Also shown on the front major surface are a few other security features, namely two printed symbols 110 in the form of the denomination of the banknote ("50"), for example by means of a color containing an optically variable pigment, and a hologram 120 in the form of a transfer element. Furthermore, the banknote has further security features, such as guilloche (not shown).

The security feature 200 according to the invention is formed by a plurality of light guide structures 220 whose light exit surfaces 210 are located on the front main surface 101 of the banknote 100 or the product layer 105. These light guide structures extend, for example, through the entire banknote body as far as the rear main surface 103. There, they end and form light entry surfaces 230 which are aligned with the rear main surface of the banknote ( Fig. 2B ). When viewing the banknote in the backlight or at least at a light incident on the rear main surface of the banknote, so that there light can enter through the light entry surfaces in the Lichtleitstrukturen, the light exit surfaces light up on the front main surface of the banknote. The light exit surfaces are arranged in such a way that together they also reflect the denomination of the banknote ("50").

The light guide structures 220 are formed by transparent material strand sections 250 that completely pass through the material of the banknote 100 and terminate its light entry surface 230 flush with the rear main surface 103 and its light exit surface 210 flush with the front main surface 101. In Fig. 2B an example of a material strand section running inside the banknote body is shown. Between the rear main surface and the front main surface, the material strand section runs on a tortuous path through the banknote body. As a result, the light entrance and the light exit surfaces are not superimposed. The material strand section is formed by a polymer, for example polymethyl methacrylate (PMMA). Alternatively, the material strand section may also be formed by a glass fiber section.

Deviating from the configuration of the light guiding structure 220 with end faces (light entry surface 230 and light exit surface 210) ending on both sides on the main surfaces 101, 103 of the banknote 100 Fig. 2A a Lichtleitstruktur whose two end faces are located on the same main surface of the banknote.

The material strand section 250 is surrounded on the outside by a hot-melt adhesive material 260 ( Fig. 2A, 2B, 2C ). This material has a refractive index which is less than that of the material of the material strand section. Therefore, light which has entered the light guide structure 220 is totally reflected upon propagation at the interface with the hot-melt adhesive. As a result, a low degree of attenuation for the propagation of light in the light guide structure is achieved. Furthermore, the hot-melt adhesive jacket serves to firmly anchor the material strand section in the material of the banknote 100 so that it can no longer be removed. For this purpose, the material of the banknote or the product layer 105 is heated to dryness after dewatering in the paper machine, so that the hot-melt adhesive softens and combines with the banknote material. Therefore, the adhesive forms both an adhesion layer and a total reflection permitting second layer having a refractive index lower than the refractive index of the material of the strand section.

It is possible that the material strand sections 250 contain absorbing and / or luminescent substances, resulting in corresponding physical properties for the light guide structures 220. If absorbers in the strand sections cause the material of the strand to have a color but do not unduly obstruct the passage of light, the light exit surfaces 210 may be perceived in color even when illuminated with white light. Several sections of material strand can be colored differently. This results in a variety of design options of light guiding structures of a security feature. If luminescent substances are contained in the material strand sections, the light exit surfaces luminesce colored or white if the luminescence lies in the visible spectral range.

A second embodiment of the banknote 100 is shown in FIG Fig. 3 shown. Apart from the further security features 110, 120, 130 already explained with regard to the first embodiment, the banknote also has a security feature 200 according to the invention, in which case the light exit surfaces 210 are arranged at different distances from one another in three mutually parallel vertical rows and within the rows are. The pattern of the light exit surfaces may, for example, indicate the denomination or the place of production of the banknote in coded form. The light guide structures 220, whose light exit surfaces are recognizable on the front main surface 101 of the banknote, run within the banknote body between the front main surface and the rear main surface in each case. All of the light guiding structures of a row together form a course that extends from a lower edge 107 to an upper edge 106 of the banknote. They are preferably oriented in the running direction (production direction H) of the round screen used for the production of the banknote paper 500 in the paper machine or the production direction when extruding a polymer film. This allows a simple production of multiple light guide structures in a defined arrangement to each other. Each light exit surface on the front main surface of the banknote is associated with a corresponding light entry surface 230 on the rear main surface 103 of the banknote.

In Fig. 4 FIG. 2 schematically shows the manufacturing method for a fiber felt material provided with light guide structures 220 in a first embodiment. The aqueous pulp is drawn in a conventional manner in the figure from the left in the manufacturing direction H by means of a round screen 300 of a paper machine (which rotates in the manufacturing direction) from a slurry of the fiber material, for example made of cotton fibers, wherein a film 310 on the Round sieve trains. This film is dried there by removing water and results in an endless paper web 500.

In the as-dried state of the paper fiber film 310, a material strand 320 consisting of a polymer is produced by means of an extrusion die 330 and introduced into the paper fiber film. The polymer may be, for example, polyamide (PA) or polycarbonate (PC), which is injected into the paper pulp slurry in the molten state. The polymer thread produced may additionally comprise a sheath of a hot-melt adhesive. For this purpose, the extrusion nozzle has a nozzle opening for the material strand and an annular gap surrounding the nozzle opening concentrically for the hot-melt adhesive material, so that the coated Material strand is produced in an extrusion step (not shown). In the paper pulp, the polymer material gradually cools and becomes solid.

Immediately behind the point of injection of the polymer thread into the paper fiber film 310 are two sequentially arranged contouring rollers 350, 360 with äquiangularen profile webs 370, which press the polymer thread locally into the paper pulp. As a result, a wave-shaped formation of the polymer thread is achieved, the first thread sections 291 are located within the paper fiber film, and wherein the front thread loops 270 protrude in second thread sections 292 from the paper material.

In the dryer section of the paper machine, the paper material entrained by the round screen 300 travels along a doctor blade 380 which shears the thread loops 270 projecting on the front main surface 101 flush with the surface of the paper material. In this case, overhead end surfaces (light entry surface 230 and light exit surface 210) of the material strand sections 250 or light guide structures 220, which are now separated from one another, are formed. The material strand sections each extend between two end faces arranged on the same front main surface of the paper web 500. This corresponds to the embodiment according to FIG Fig. 2A (one-sided variant).

In Fig. 4 is not shown that it is not only possible to integrate a single such polymer thread in the direction H of the paper machine in the material but a plurality of parallel polymer threads, which in the illustration of Fig. 4 are guided one behind the other and parallel to each other. As a result, a plurality of parallel rows of light guide structures 220 are formed running side by side. This leads to the embodiment according to Fig. 3 ,

In Fig. 5 FIG. 2 schematically shows the manufacturing method for a fiber felt material provided with light guide structures 220 in a second embodiment. As in the first embodiment, the aqueous pulp is scooped in a conventional manner in a direction of manufacture H by means of a circular screen 300 of a paper machine (not shown) from a slurry of the fiber material, for example cotton fibers, forming a film 310 on the round screen which is there is dried by removing water and results in an endless paper web 500. Also in this case, an existing example of PA or PC material strand is produced by means of an extrusion die 330 and introduced into the paper fiber film. The polymer thread produced can in turn additionally comprise a sheath made of a hot-melt adhesive (not shown). In Fig. 5 not shown is an arrangement of two contouring rollers one behind the other in the direction of manufacture, which insert the polymer thread at regular intervals into the paper pulp mass and in this case partially push it out again. This will make the in Fig. 5 shown wavy formation of the polymer thread achieved. In this case, not only the forward thread loops 270 but also thread loops 280 protrude from the paper material at the rear major surface 103 in second sections 292. The polymer thread is located in the first thread sections 291 within the film.

In the dryer section of the paper machine, the paper material entrained by the round screen 300 travels along both sides of the paper web 500 doctor blades 380, 390, which shear the projecting front and rear thread loops 270, 280 flush with the surfaces 101, 103 of the paper web. In this case, front end faces (light exit surfaces 210) and rear end faces (light entry surfaces 230) of the material strand sections 250 or light guide structures 220, which are now separated from one another, are formed. The material strand sections or light guide structures each extend between two end faces arranged on different main surfaces of the paper web. This corresponds to the embodiment according to FIG Fig. 2B (two-sided variant).

In Fig. 6A, 6B an arrangement for machine verifying a banknote 100 is shown, which has unilaterally and side by side arranged light entry surfaces 230 and light exit surfaces 210 of the security element 200 (corresponding Fig. 2A ), wherein the strand of material in the paper in a to the embodiment of Fig. 3 rotated by 90 °, namely from right to left or vice versa. The assembly includes an excitation and read module 400 that extends across the bill. The longitudinally extending excitation and read-out module is equipped with a light source 410 having a multiplicity of LEDs 430 arranged one after the other in the longitudinal extent and with a detection element 420. The detection element has photodiodes 440 arranged one behind the other in the longitudinal extension, which can detect a light incidence. The banknote is traversed under this module in the direction P indicated by the arrow, so that the respectively juxtaposed pairs of light entry surfaces 230 and light exit surfaces 210 of the light guide structures 220 are traversed. In this case, light from the LED 430 falls via the light entry surfaces 230 into the light guide structures 220 and passes over the light exit surfaces 210 to the photodiodes 440. When passing through the module, therefore, this module detects the presence of the light guiding structures in the banknote, their position on the front main surface 101 of the banknote being able to be determined by detecting the position of the banknote relative to the module and recognizing an optical guiding structure be determined by the addressed photodiode.

Reference numerals:

100

Value or security product, banknote

101

front main surface

102

left border area

103

rear main surface

105

product location

106

upper edge

107

lower edge

110

printed symbol

120

hologram

130

watermark

200

safety feature

210

second end face, light exit surface

220

Lichtleitstruktur

230

first end face, light entry surface

250

Material strand section

260

Adhesion layer, hot-melt adhesive material

270

front thread loop

280

behind lying thread loop

291

first (material strand, thread) section

292

second (material strand, thread) section

300

Round Screen

310

(Pre-material) film, (paper fiber) film

320

material strand

330

extrusion

350

Konturierwalze

360

Konturierwalze

370

profile web

380

doctor blade

390

doctor blade

400

Excitation and read-out module

410

light source

420

detection element

430

LED

440

photodiode

500

(Endless) paper web, banknote paper

H

making direction

P

traversing

Claims (11)

1. Value product or security product (100) with a security feature (200), formed by at least one light-guiding structure (220), which extends through a product layer (105), having a front main surface (101) and a rear main surface (103), of the value product or security product, wherein the at least one light-guiding structure (220) comprises in each case a first end face (230) for letting light in, and a second end face (210) for letting light out, and wherein all the end faces (210, 230) are located in the region of one of the main surfaces (101, 103), wherein the light-guiding structure (220) is formed by a material strand segment (250), characterised in that the at least one light-guiding structure (220) is held by means of an adhesion layer (260) in the product layer (105).
2. Value product or security product (100) according to claim 1, characterised in that the material strand segment (250) is formed by a transparent material with a first refractive index, and is surrounded by a second material which exhibits a second refractive index which is lower than the first refractive index.
3. Value product or security product (100) according to any one of the preceding claims, characterised in that the at least one light-guiding structure (220) is formed from a polymer material.
4. Value product or security product (100) according to any one of the preceding claims, characterised in that the adhesion layer (260) is formed by a hot-melt adhesive.
5. Value product or security product (100) according to any one of the preceding claims, characterised in that the at least one light-guiding structure (220) contains at least one material which is absorbent in the visible spectral range, and/or at least one material which is luminescent in the visible spectral range.
6. Value product or security product (100) according to any one of the preceding claims, characterised in that at least two light-guiding structures (220) are arranged running one behind another in the product layer (105) in a production direction (H) of the material of the product layer (105).
7. Value product or security product (100) according to any one of the preceding claims, characterised in that the product layer (105) is formed at least essentially from a fibre felt substance.
8. Method for producing the value product or security product according to any one of claims 1 to 7, comprising the following method steps:

   (a) Formation of a film (310) comprising a front main surface (101) and a rear main surface (103) of a preliminary material suitable for the formation of a product layer (105);

   (b) introduction of a material strand (320) into the film (310) of the preliminary material, such that at least one first section (291) of the material strand (320) runs inside the film (310) of the preliminary material, and at least one second section (292) of the material strand (320) runs outside the film (310) of the preliminary material, and such that the material strand (320) passes between the at least one first section (291) and the at least one second section (292) through at least one of the main surfaces (101, 103) of the film (310);

   (c) conversion of the film (310) of the preliminary material, with the formation of the product layer (105), wherein the material strand (320) is fixed in the product layer (105) for the formation of at least one light-guiding structure (220); and

   (d) removal of the at least one second section (292) of the material strand (320) running outside the product layer (105), such that the at least one light-guiding structure (220) occurs in the form of the at least one first section (291) of the material strand (250).
9. Method according to claim 8, characterised in that the preliminary material is a fibre pulp containing a fluid, and that the film (310) is converted by the removal of the fluid, with the formation of the product layer (105).
10. Method according to one of claims 8 and 9, characterised in that the material strand (250) is introduced by the extruding of a polymer material or by the insertion of a glass fibre into the film (310) of the preliminary material.
11. Method according to claim 10, characterised in that, on introduction into the preliminary material, the material strand (250) is pressed locally into the preliminary material.

Images