The invention relates to a security element transfer material for the register-accurate transfer of security elements with a layered composite structure to a value document substrate, a method for manufacturing the security-element transfer material, a method for register-accurate transfer of security elements from the security element transfer material to a value document substrate, and value documents that are equipped in register-accurate manner with a security element while employing the security element transfer material.
Value documents such as banknotes, deeds, checks, identification documents or credit cards, in particular banknotes, are usually equipped with security elements which allow the authenticity of the value document to be checked and which at the same time serve as protection against unauthorized reproduction. The security elements employed for this are often not supplied individually, but in the form of transfer bands with a multiplicity of security elements configured as transfer elements. It is characteristic of transfer bands that the security elements are prepared on a carrier layer in the reverse order of the layers as they are later to be present on the value document to be protected.
The carrier layer is typically what is known as a temporary carrier, i.e. it is pulled off the layer structure of the security elements during the transfer. On the side opposite the carrier layer, the transfer bands have adhesive properties, which is usually achieved by applying a layer of heat-seal adhesive. The heat-seal adhesive melts during the transfer of the security elements and sticks the security elements with the value document or another object of value to be secured. The transfer band is placed with the heat-seal adhesive layer onto the object and pressed thereon by means of a heated transfer stamp or a transfer roller and transferred to the value document in the outline shape of the heated transfer stamp. Transfer elements, transfer bands and the transfer of transfer elements to target substrates are described, for example, in the publication EP 0 420 261 B1.
It is also known not to emboss security elements from the layered composite at the time of transfer to a value document substrate, but to punch them out of the layered composite and to pull off the surrounding layered composite material, i.e. to “weed” it, so that the security elements are present as individual patches on the temporary carrier material. The transfer then does not require a transfer device in the form of the security elements but can take place by means of a smooth transfer roller.
The security elements are transferred to value documents at high speed by bringing together and pressing together webs of transfer material and webs of value documents or sheets of value documents, each of which has a multiplicity of individual copies, wherein it is necessary to ensure that the security elements are applied to the correct location on each individual value document. For this purpose, register marks are required, which are read by a detector, so that the positions of the transfer material web and value document substrate web relative to one another can be suitably matched to one another during the entire transfer process on the basis of the transmitted signals. Register marks are typically colored prints with strongly light-absorbing inks or strongly light-reflecting prints that have a defined shape, such as, e.g., stripes or bar codes.
In the case of security elements which are embossed from the layer structure during the transfer process, the register exactness between the transfer material and the value document substrate when embossing the security elements can be set without any problems by means of register marks provided on the embossing foil adjacent to the security elements. However, in cases in which it is not possible or not desired to emboss the security elements from their layered composite, the transfer in exact register of the security elements to value document substrates poses a problem.
Embossing the security elements from their layer structure is always difficult when the layer structure is comparatively thick and/or contains layers that have the result that no clean separating edge is produced when a security element is embossed. Such layers are, for example, layers of highly crosslinked lacquers and of hard or brittle lacquers that do not break smoothly at the edge of the application tool during embossing, but instead break in an undefined manner. This can result in lacquer flakes, which, as disturbing impurities, impair the quality of the value documents and contaminate the machines employed, so that cleaning has to be carried out frequently. Such layers are also layers made of comparatively soft and elastic lacquers, which likewise do not break smoothly at the edge of the application tool when the security elements are embossed from their layered composite, but rather tend to tear in an undefined manner or to break incompletely, so that in extreme cases the security elements cannot be embossed from their layered composite at all.
It is completely impossible for the security elements to be embossed from their layered composite if the layer structure contains a foil layer. Such permanent carrier materials are absolutely necessary, for example, if the security elements would otherwise be too unstable or if the security elements are intended to close through openings in value documents. In such cases, the outlines of the security elements must be cut out of the layered composite structure and the layered composite material must be removed between the individual security elements. The required register marks then have to be applied to the temporary carrier material in a subsequent process step, however which does not solve the problem of register exactness, which is difficult to maintain, but merely shifts it: because the register exactness achieved when transferring the security elements to value document substrates now depends on the register exactness with which the register marks are applied to the temporary carrier material of the security elements.
The object of the present invention is therefore to supply a security element transfer material which makes it possible to apply security elements to value document substrate webs or value document substrate sheets in exact register.
The object of the present invention is in particular to supply a security element transfer material that makes it possible to apply security elements in exact register to value document substrate webs or value document substrate sheets if the security elements contain one or several layers in their layer structure which make it difficult or impossible to transfer the security elements by separating them from the security element layered composite during the transfer process, such as, e.g., a foil layer or a lacquer layer which tends to break or tear in an undefined manner.
It is also an object of the present invention to supply methods for manufacturing such a security element transfer material, methods for transferring security elements from the security element transfer material to a value document substrate in exact register, and value documents which have been equipped with a security element in exact register while employing such a security element transfer material.
The objects are achieved by the security element transfer material, the method for manufacturing a security element transfer material, method for register-accurate transfer of security elements and by the value document, each of which having the features as specified in the independent claims. Embodiments of the invention are specified in the respective dependent claims.
The basic idea of the present invention is, in a security element transfer material, to separate the security elements from the layered composite already before the transfer process to a value document substrate and at the same time to determine the position of the required register marks. For this purpose, a starting material layered composite is manufactured which has the desired security element layer structure on a temporary carrier material, then the outline shapes of the desired security elements and outline shapes of register mark elements are incised into the layered composite material (with the exception of the temporary carrier material), and finally the layered composite material is pulled off the temporary carrier material outside the outline shapes of the security elements and the register mark elements, so that the security elements and the associated register mark elements are present as “islands” on the temporary carrier material. The register mark elements have the same or a similar layered composite structure as the security elements.
According to one embodiment of the invention, the outline shape of the register mark elements is chosen such that it corresponds to the contour of the desired register mark. In another embodiment of the invention, the register mark elements function as carrier elements for the register marks, which exactly define the position of the register marks, which can be necessary with more complex register marks, such as bar codes.
The invention will hereinafter be described with reference to figures. It is pointed out that the figures are not true to proportion and not true to scale. Furthermore, features disclosed in connection with a specific figure are in no way to be understood in such a manner that the relevant features can only be applied in combination with the other features shown and/or described in the corresponding figure. Rather, features described in connection with a specific embodiment can each be combined independently with features from other embodiments or can be utilized very generally in the security element transfer material according to the invention. Incidentally, the security element transfer material, the method for manufacturing the security element transfer material, the method for register-accurate transfer of security elements to a value document substrate and the value document which has been equipped with a security element while employing the security element transfer material, represent different aspects of the same invention. Accordingly, any disclosure related to a particular aspect of the invention applies equally to the other aspects of the invention.
In the figures, the same reference numbers denote the same or corresponding elements. There are shown:
The foil patch 2a shows, for example, a figurative representation, a color shift effect or any other desired effect (not represented in
The security strips 2b and 2c have printed regions 17b, 18b, or 17c, 18c, which complement line-shaped or bar-shaped, interrupted prints 17, 18 of the banknote 10 to form closed lines in each case. The security strips 2b, 2c must therefore be transferred precisely to the banknote substrate in such a manner that the imprints 17b, 18b, 17c, 18c are applied exactly in the interruptions in the lines 17, 18.
For precise, i.e. application in exact register or register-accurate application of security elements, register marks are required which have a precisely defined position in relation to the security element to be transferred, and with the aid of which the feeding of the security element transfer material relative to the value document substrate can be controlled in such a manner that each security element is applied to the specific location intended for it on the value document substrate.
The security element transfer material 1 according to the invention is manufactured starting from a starting material layered composite 20, which is conventional per se and is composed of at least one temporary carrier material 5 and a functional layer structure 21 on a first surface or a first main area 5′ of the temporary carrier material 5. The functional layer structure 21 must be detachable from the first main area 5′ of the temporary carrier material 5, which is why a release layer 24 is preferably, but not necessarily, provided between the functional layer structure 21 and the temporary carrier material 5. On the main area of the functional layer structure 21 facing away from the temporary carrier material there is a heat-seal adhesive layer 26 or another layer which gives the later security elements adhesive properties for connection to a value document substrate. A primer or adhesion promoting layer 25 can be provided between the functional layer structure 21 and the layer accounting for adhesive properties 26.
In the embodiment represented in
Preferred permanent carrier materials 22 are transparent or translucent foils, for example made of polyester, such as polyethylene terephthalate, of polyethylene or polypropylene. Through openings covered with transparent or translucent foils remain recognizable for a viewer. Such foils can also be employed as temporary carrier materials, but non-transparent or translucent foils are also suitable, and typical thicknesses of both the permanent and temporary carrier substrates range from about 4 to 20 μm. The materials that have been tried and tested in the field of security elements are preferably used for the heat-seal adhesive layer and the optional release layer and primer layer.
The functional layer structure 21 also includes feature layers, i.e. layers that have visually recognizable or machine-detectable features, such as metal layers, layers of metal effect inks, layers with color pigments or fluorescent pigments, liquid crystal layers, coatings with a color shift effect, layers with matte structures, such as disclosed e.g. in the publication WO 2007/107235 A1, printed colored motif layers, layer combinations, such as a layer with a color shift effect underlaid with a specific color, layers with magnetic pigments, etc.
The type and manufacture of the functional layers or the functional layer structure is fundamentally irrelevant for the present invention, and the present invention comprises security element transfer materials with security elements with any layered composite structure. However, the special advantages of the present invention come into play in particular when the security elements have a permanent carrier material 22, as represented in
Security elements for which the present invention is particularly suitable are, in particular, security elements which have a layer structure with numerous functional layers (feature layers), including a, for example, holographic security feature, ink-receiving, protective and laminating layers, ink layers, fluorescent prints, etc. Such security elements have, for example, a permanent carrier material, as represented in
To manufacture a security element transfer material 1, as illustrated in
The outline shapes of the security elements 2 and the register mark elements 3 are then incised into the resulting starting material layered composite 20, as illustrated in
The incising of the outline shapes 8 of the security elements 2 and the outline shapes 9 of the register mark elements 3 is preferably carried out by means of a laser, since the best precision can be achieved in this manner. However, the term “cutting” here is generally to be understood as meaning all methods known to a person skilled in the art for separating the security elements and the register mark elements from the layered composite material surrounding them, for example stamping. If a laser is used for cutting, additional measures are preferably taken that are suitable for preventing deep cutting of the laser, in order to prevent damage to the temporary carrier material 5, which could lead to destabilization of the temporary carrier material 5 and, in the worst case, to tearing of the security element transfer material 1. Such an undesired deep cutting into the temporary carrier material 5 is indicated in
After incising the outline shapes 8 of the security elements and the outline shapes 9, the layer 15 outside the outline shapes of the security elements and the register mark elements, that is, the entire layer structure on the temporary carrier material 5, which is located outside the outline shapes of the security elements and the register mark elements is pulled off the temporary carrier material 5. The result is the security element transfer material 1 represented in
Otherwise, when transferring the security elements to a value-document substrate, care must be taken that suitable transfer conditions are created only for the security elements. With conventional transfer by heat sealing, this can be accomplished in a simple manner by applying pressure and heating only in the region of the security elements.
In the embodiment represented in
After the layered composite material 15 has been pulled off the temporary carrier material 5, the security element transfer material 1 represented in
In the embodiment represented in
The manufacture of a security element transfer material 1 according to the invention with security elements 2 without permanent carrier material is illustrated in
First, a starting material layered composite 20 is manufactured, which, apart from the absence of the permanent carrier material 22, can be identical to the starting material layered composite 20 represented in
The starting material layered composite 20 is built up starting from the temporary carrier material on whose first main area 5′ there are applied the feature layers and auxiliary layers of the functional layer structure 21 in the appropriate order (i.e. in the reverse order in which the layers are to be present later on the value document substrate) and finally the heat-seal adhesive layer 26.
As explained in connection with
Therefore, the layered composite material is adhesively bonded at the free surface of the heat-seal adhesive layer with a release foil 27 which stabilizes the layered composite material sufficiently to allow it to be pulled off the temporary carrier material 5. A suitable release foil 27 is, for example, a hole mask, as represented in
Instead of a hole mask, a full-area release foil can also be employed. In such a case, it is expedient to apply a separate adhesive layer to the heat-seal adhesive layer 26 for adhesively bonding the release foil, wherein the places are left out where the outline shapes 8 of the security elements and the outline shapes 9 of the register mark elements are to be incised, i.e. the adhesive layer contains gaps as described for the hole mask 27. The full-area release foil is subsequently adhesively bonded and the outline shapes 8, 9 are incised into the layered composite material, wherein the release foil is also severed. In the regions without an additional adhesive layer, the non-bonded release foil can be easily removed, for example by blowing off. In contrast, the regions of the layered composite material bonded with the release foil 27 now have sufficient stability to be able to be pulled off the temporary carrier material 5.
A polyethylene terephthalate foil with a thickness of about 4 to 20 μm can be employed as the release foil, for example, but other materials and thicknesses are also suitable as long as the foil is sufficiently elastic and stable. A laminating adhesive is preferably employed to adhesively bond a full-area release foil.
By pulling off the layered composite material outside the outline shapes 8, 9, the security element transfer material 1 represented in
However, the present invention is not limited to a security element transfer material with specific security elements.
In order to guarantee residue-free detachment outside the outline shapes of the security elements and the register mark elements, which is essential for the manufacture of high-quality security elements, the functional layer structure of the security elements must be completely severed, i.e. the cutting lines must extend to the temporary carrier material 5. On the other hand, the temporary carrier material 5 should not be cut in order to avoid destabilization. However, it is difficult to cut so precisely that the cuts end immediately on the first main area 5′ of the temporary carrier material 5. After all, the layer structures to be severed and the carrier materials that are not to be severed are materials with thicknesses in the micrometer range. The security element layer structures typically have thicknesses in the range from about 20 μm to 30 μm and the temporary carrier materials typically have thicknesses in the range from 10 μm to 20 μm. It is therefore preferred to employ a temporary composite carrier material, which is composed of at least one first carrier substrate and one second carrier substrate, which are inseparably connected by means of an adhesive layer, instead of a single-layer temporary carrier material. In this context, inseparable means that the bond cannot be separated during the transfer process of the security elements or during any processing or treatment processes of the security element transfer material.
Transfer to objects of value usually takes place by a heat-sealing process, which is why thermoplastic adhesives are less suitable unless they have very high softening temperatures. Crosslinking adhesives, for example solvent-based 2K PU adhesives, are preferred. A starting material layered composite 20 with temporary carrier composite material 50 for manufacturing a security element transfer material 1 according to the invention is represented in
The starting material layered composite 20 represented in
The cut denoted by X2 in
A “self-healing” adhesive is preferably employed and the cutting of the outline shapes of the security elements 2 and the register mark elements 3 is carried out at a time when the adhesive has not yet fully cured. In this manner, cuts in the adhesive layer can be reformed. The adhesive, which is still plastic, can even penetrate cuts in the temporary carrier substrates and bond them at least to the extent that the stability of the cut temporary carrier substrates does not suffer significantly.
If the cutting is carried out by means of a laser, the second temporary carrier substrate 53 can also be protected by adding laser-absorbing or laser-reflecting substances, for example metal pigments, to the adhesive. However, the protective effect of laser-absorbing and laser-reflecting substances can also be made use of in the case of single-layer temporary carrier materials, for example by vapor-depositing a laser-absorbing or laser-reflecting substance on the first main area 5′ of a temporary carrier material 5.
The temporary carrier composite material 50 can also have more than two temporary carrier substrates, wherein two temporary carrier substrates are each connected by means of an adhesive layer. However, preferably a layer thickness of about 70 μm for the entire carrier composite material 50 should not be exceeded. Preferred layer thicknesses are in the range from 20 μm to 40 μm.
A starting material layered composite with incised outline shapes 8 of security elements 2 and outline shapes 9 of register mark elements 3 is fed to a separating roller 30 on which the temporary carrier material 5 and the layered composite material 15 are pulled apart. Since the incisions in the layered composite material 15, which define the outline shapes 8, 9, completely sever the layered composite material 15, the security elements 2 and the register mark elements 3 are not pulled off the temporary carrier 5 together with the layered composite material 15, but remain adhering on the first main area 5′ of the temporary carrier material 5, while holes 28, 29 form in the corresponding places of the layered composite material. The resulting security element transfer material 1 has the security elements 2 and the register mark elements 3 assigned thereto, which are each detachably connected with their first main areas 2′, 3′ to the first main area 5′ of the temporary carrier material 5. The second main areas 2″, and possibly also the second main areas 3″ have adhesive properties, so that the security elements 2 can be transferred to a value document substrate by means of a suitably positioned transfer roller.
In the embodiments represented in
The incisions in the layered composite material 15, which define the outline shapes of the security elements 2 and the register mark elements 3, are denoted by X1, X2, X3, X4 in
The security element transfer material 1 represented in
After pulling off the layered composite material 15 from the temporary carrier material 50, a security element transfer material 1 (
The security element transfer material 1 represented in
Deviating from the embodiments illustrated in the previous figures, in this embodiment the register mark elements 3 are not register marks themselves but act as carriers for register marks 4. Register marks 4 in or on register mark elements 3 can be manufactured in various ways, for example by demetallizing metal layers using a so-called washing ink. Such a method is described in the publication EP 1 972 462 B1. To produce the register marks 4 in the starting material layered composite represented in
After the layered composite material 15 has been pulled off the temporary carrier material 50, the security element transfer material 1 represented in
An alternative functional layer structure 21, not shown here, is composed, like the structure shown in
In the embodiments represented in
An additional work step is required for the production of register marks 4, the contours of which are not identical to the outline shape of a register mark element 3, but for which a register mark element 3 serves as a carrier. However, the problem of a register inaccuracy when producing the register marks 4 does not arise, since the register marks 4 are produced before the layered composite material 15 is pulled off the temporary carrier material outside the outline shapes of the security elements 2 and the register mark elements 3. It is therefore possible to produce register marks with larger dimensions than are required. The excess regions are also removed when the layered composite material 15 is pulled off, as indicated by the dashed lines in
When manufacturing a value document as represented in
In order to save space and to avoid having to laboriously manufacture large area regions of costly layered composite material, most of which is not employed but discarded, namely the entire region outside the outline shapes 8 of the security elements 2 and the outline shapes 9 of the register mark elements 3 (see
Transverse to the transport direction, different distances between the security elements on the security element transfer material on the one hand and the value document substrate 11 on the other hand cannot be compensated for by different transport speeds. The security elements on the security element transfer material 1 must therefore have the same distances d2 from one another in the transverse direction as they should have after the transfer to a value-document substrate web 11. Corresponding arrangements are represented in
In the transport direction, the security elements 2 each have short distances d3 (d3<d1). In the embodiment represented in
The process of transferring security elements 2 from security element transfer materials 1 according to the invention to value document substrates 11 is represented schematically in
In the application method represented in
Value document substrates can be paper or polymer substrates or also paper/polymer composite substrates. The term “value document” is not necessarily to be understood in such a manner that it already has to be a value document in a form fit for circulation. Rather, the term within the meaning of the present invention includes every preliminary stage on the way to the manufacture of a value document, for example so-called “security paper”, which only has some of the features of the later value document. The transfer of a security element from the security element transfer material according to the invention to the value document substrate can be, for example, the first step in the manufacture of a value document. Value documents within the meaning of the present invention are in particular banknotes, certificates, checks, identification documents, identification cards and credit cards, but also other documents whose unique identification is to be ensured and which are to be protected against forgery.
Number | Date | Country | Kind |
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10 2020 005 769.1 | Sep 2020 | DE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2021/025325 | 8/27/2021 | WO |