SAFETY ELEMENT TRANSFER MATERIAL, METHOD FOR MANUFACTURING THE SAME AND USE

Description

[0001] The invention relates to a security element transfer material comprising a security element layer composite arranged on a temporary carrier and detachable from the temporary carrier. The layer composite can be applied via an adhesive layer to a valuable object, such as a valuable document, that is to be secured to increase its forgery security. The invention further relates to a method for producing the security element transfer material and to a use of the security element transfer material for securing a valuable object, in particular a valuable document.

[0002] Valuables, such as branded goods or valuable documents, especially banknotes, are often equipped with security elements that allow the authenticity of the valuable object to be verified and which also serve as protection against unauthorized reproduction. The security elements used for this purpose are often not provided individually, but in the form of transfer ribbons with a large number of security elements designed as transfer elements. A characteristic of transfer ribbons is that the security elements are prepared on a carrier layer, whereby the order of the layers of the transfer elements is usually reversed compared to the layer order later present on the object to be protected. The carrier layer is typically peeled off the layer structure of the security elements during the transfer.On the side opposite the carrier layer, the transfer tapes have an adhesive layer, usually made of a heat-sealing adhesive or heat-sealing varnish, which melts during the transfer of the security elements and bonds the security elements to the object to be secured. The transfer tape is applied to the object with the heat-sealing adhesive layer and pressed onto it using a heated transfer stamp or transfer roller, transferring it to the object in the outline of the heated transfer stamp. Transfer elements, transfer tapes, and the transfer of transfer elements to target substrates are described, for example, in EP 0 420 261 B1 and WO 2005 / 108108 A2.

[0003] Instead of shaping the transfer elements using the transfer stamp during the transfer process, the individual transfer elements can also be prefabricated on the transfer belt in the desired outline shape. Prefabrication of separate individual security elements is useful, for example, when the security elements have a layer structure that makes it difficult to cut through the entire layer structure precisely during the transfer process. This is the case, for example, when the layer structure of the security element to be transferred contains a permanent carrier substrate, such as a plastic film. Carrier substrates within the layer structure of security elements are useful when the security elements have to be particularly stable, for example when they have to be self-supporting because they are to be used to close a through opening in the object to be secured.Depending on the object and the size of the opening to be sealed, high demands can be placed on the stability of the security elements. Banknotes, for example, are subjected to considerable stress during their circulation period, being scuffed, bent, and possibly exposed to moisture. The security elements must be able to withstand these stresses just as much as the banknote paper itself, otherwise there is a risk that the through opening in the banknote will be exposed after a certain period of circulation.

[0004] Security elements whose layered structure comprises a stable carrier substrate, typically a plastic film, must be present on a transfer material as prefabricated individual elements. This means that the outline shapes of the security elements must be pre-cut into the security element material. Pre-cutting can be carried out using a laser, for example. This presents the problem that the cutting depth must be very precisely controlled in order to, on the one hand, cut through the entire layered structure of the security element, while, on the other hand, not damage the carrier material that is separated during the transfer. Plastic films are typically used as the carrier material. While plastic films have high tear resistance, they have low tear propagation resistance.If they are cut, it is almost impossible to avoid the security element transfer material, which is available as a continuous material, tearing in some places during the transfer process of the security elements to valuables. It must also be taken into account that the layer structures to be severed and the carrier films that cannot be severed are materials with thicknesses in the micrometer range. The security element layer structures typically have thicknesses in the range of around 20 µm to 30 µm, and the carrier films typically have thicknesses in the range of 10 µm to 20 µm. Given the precision required here, it is difficult to carry out a cutting process in such a way that the security element layer composite is completely severed, but the cutting process is stopped in time so that the carrier film is not cut anywhere.However, due to the partially cut carrier film, the security element transfer material loses stability and may even tear, which is why a precise and smooth application of the security elements from the continuous material to the products to be protected can no longer be guaranteed.

[0005] A security element transfer material in the form of a continuous material, in which security elements are pre-cut in the desired outline shapes, and the pre-cut elements can then be transferred to the products to be secured without the risk of tearing the carrier material, is known from WO 2010 / 031543 A1. The security element transfer material is a continuous material, in particular a strip with a length of several hundred meters and a width of a few millimeters / centimeters up to several meters. The security element transfer material comprises a security element layer composite, i.e., the actual security element material, and a temporary carrier, i.e., the material on which the security elements are "stored." The temporary carrier is based on a carrier layer composite consisting of a first and a second temporary carrier substrate, which are permanently bonded together by means of an adhesive layer.The security element layer composite is bonded to a temporary carrier either directly or via a release layer. The release layer is of a conventional type and facilitates the detachment of the security elements from the temporary carrier during the transfer process to a valuable object. The temporary carrier is located on the side of the security element layer composite that faces the viewer after the security elements have been transferred. The term "temporary" carrier substrates expresses that, unlike the "permanent" carrier substrate, these carrier substrates are not part of the security elements. The designation of the temporary carrier as a carrier layer composite prevents the stability of the temporary carrier from being compromised by cutting into the temporary carrier when the outline shapes of the security elements are cut.A comparable result cannot be achieved simply by making a single temporary carrier film correspondingly thicker, as plastic films have low tear resistance. This means that if a film is even slightly cut, it will easily tear further and, under certain circumstances, completely through. This is different with the carrier layer composite, consisting of a first and a second temporary carrier substrate, which are permanently bonded together by an adhesive layer: even if one of the temporary carrier substrates is completely severed, the other temporary carrier substrate (or possibly the other temporary carrier substrates) generally remains undamaged and therefore stable. The adhesive also forms an additional "buffer zone" between the temporary carrier substrates.

[0006] The method described in WO 2010 / 031543 A1 involves weeding patch films prior to application. To do this, the shapes of the patch are punched into the layers to be transferred, i.e., the layers are broken through with the punch. During weeding, these layers are then removed in the areas outside the patch, while they remain on the carrier film in the patch areas. This ensures that the patches have clean edges after application. Disadvantages of the method described in WO 2010 / 031543 A1, however, are the number of required work steps and the high material usage.

[0007] WO 2017 / 102744 A1 describes a method for producing a security element, wherein in the method a base film is provided which has a first carrier film and a single-layer or multi-layer decorative layer, wherein a first adhesive layer is applied to a second carrier film and a second adhesive layer is applied to the surface of the first carrier film facing away from the decorative layer or wherein the second adhesive layer is applied to the surface of the first carrier film facing away from the decorative layer and the first adhesive layer is applied to the second adhesive layer, and wherein the second carrier film is applied to the first carrier film in such a way that the first adhesive layer and the second adhesive layer are arranged between the first carrier film and the second carrier film, and wherein the first adhesive layer in a first region,the at least one first partial area of ​​the base film is at least partially covered, activated, and in a second area adjacent to this area, however, the first adhesive layer is not activated, not provided, only partially provided, or deactivated, wherein the first carrier film is at least partially severed along the boundary line defining the at least one first partial area and separating the at least one first partial area from a second partial area of ​​the base film, and wherein a second part of the base film comprising the second partial area is peeled off from the second carrier film, wherein in the at least one first partial area, the base film adheres to the second carrier film due to the activated first adhesive layer, and a first part of the base film comprising the at least one first partial area remains on the second carrier film.

[0008] EP 3342602 A1 describes a method for producing a multi-layer value document substrate, comprising: Providing a first and at least one second layer, wherein the first layer has at least one optical element; and producing the value document substrate by bonding the provided layers, wherein the at least one second layer has a varying transparency.

[0009] US10391807B2 describes a polymer layer composite for a security and / or value document, comprising at least two polymer layers bonded to one another, wherein in and / or on the composite there is at least one surface printed with a print layer absorbing in the visible range on a polymer layer of the composite, the absorbing print layer forms at least one print area and all print areas on the printed surface of the polymer layer together have an area proportion of at least 50% and at most 95%.

[0010] The invention is based on the object of providing a security element transfer material which is improved compared to the prior art and whose production requires fewer work steps and a reduced use of material.

[0011] This problem is solved alternatively by the feature combinations defined in main claims 1 and 8. Further developments are the subject of the dependent claims. Detailed description of the invention

[0012] For the purposes of this invention, viewing in reflected light means illuminating the valuable document from one side and viewing it from the same side. Thus, viewing in reflected light occurs, for example, when the front of the valuable document is illuminated and also viewed.

[0013] For the purposes of this invention, viewing in transmitted light is the illumination of a valuable document from one side and the viewing of the valuable document from another side, in particular the opposite side. Viewing in transmitted light thus occurs, for example, when the back of the valuable document is illuminated and the front of the valuable document is viewed. The light thus shines through the valuable document.

[0014] A valuable document within the meaning of the invention can be, for example, banknotes or identification documents, but also shares, certificates, postage stamps, checks, admission tickets, tickets, airline tickets, ID cards, visa stickers, or similar items, as well as labels, seals, packaging, or other elements. The simplified term "value document" therefore always includes documents of the aforementioned type. The term "value document" also includes security paper for the production of banknotes. The term "banknote" includes, in particular, a paper banknote, a polymer banknote, or a composite banknote.

[0015] The transfer element, i.e., the security element to be transferred, can be, in particular, a transfer patch or transfer label, or a transfer strip or transfer thread. The invention is described in the following detailed description using the example of a transfer patch and should therefore not be construed as being limited to a patch.

[0016] Instead of the term "feature layer," the term "functional layer" is also used here. A functional layer can be a single (functional) layer or multiple (functional) layers.

[0017] The security element transfer material according to the invention comprises a carrier substrate, namely a plastic film provided with a plastic layer produced by coextrusion. Depending on the materials used for the plastic film on the one hand and for the plastic layer on the other, plastic film / plastic layer arrangements can be produced which, at the interface between the plastic film and the plastic layer, either tend towards high delamination or exhibit reliable adhesion and are thus resistant to delamination. The term "delamination" refers here to delamination, i.e., the detachment of layers within a composite or laminate. The plastic film / plastic layer arrangement used according to the invention is a coextruded film, i.e.a coextruded film, and thus a composite film made of several layers, in which several properties of different film materials are combined. The use of a polyester film, e.g., polyethylene terephthalate (PET), as a carrier substrate in conjunction with a plastic layer based on a foreign plastic material, e.g., pure polyethylene naphthalate (PEN), applied thereon by coextrusion, leads to a plastic film / plastic layer composite film that is prone to delamination. Pure polyethylene naphthalate (PEN) has poor adhesion to polyethylene terephthalate (PET) and leads to insufficient anchoring of the plastic layer coextruded onto the carrier substrate. In contrast, the use of a polyester film, e.g.,Polyethylene terephthalate (PET) as a carrier substrate in combination with a plastic layer based on polyethylene naphthalate (PEN) applied thereon by coextrusion, to which a certain amount of polyethylene terephthalate (PET) is added, to form a plastic film / plastic layer composite film that is stable against delamination.

[0018] A plastic film / plastic layer composite film prone to delamination is used in the security element transfer material according to the first aspect of the present invention, which is explained in more detail in the following description: The security element transfer material according to the invention as defined in claim 1 contains a temporary carrier substrate, namely a plastic film, and a security element layer composite comprising a plastic layer produced by coextrusion with low adhesion to the temporary carrier substrate, a feature layer, and an adhesive layer suitable for bonding the transfer element to a valuable article. The temporary carrier substrate is, for example, a polyester film such as a polyethylene terephthalate (PET) film. The plastic layer produced by coextrusion with low adhesion to the temporary carrier substrate can expediently be based on polyethylene naphthalate (PEN).By using the coextruded film, security element transfer materials can be obtained that have a significantly thinner overall thickness compared to the security element transfer materials known in the prior art. This is possible because the coextruded plastic layer can be produced very thinly, in particular with a thickness of less than 1 µm. The coextruded plastic layer expediently has a layer thickness in the range of 2 to 4 µm.

[0019] The security element transfer material according to the first aspect of the invention is particularly suitable for achieving a thin, patch-shaped security element applied to a security paper or a polymer substrate such as a polymer banknote, wherein the security paper or polymer substrate is fully covered by the security element in the region of the security element arranged thereon (ie the security paper or polymer substrate preferably has no recess in the region of the security element arranged thereon that is covered by the security element).

[0020] When the transfer element is bonded to a valuable object, the release or detachment within the security element transfer material according to the first aspect of the invention takes place at the interface between the plastic film and the plastic layer produced thereon by coextrusion.

[0021] Because the co-extruded plastic layer is present on top as the outermost layer in the patch-shaped security element applied to a security paper or a polymer substrate such as a polymer banknote, excellent protection of the sensitive security element layer composite against mechanical damage in banknote circulation or against chemical damage by solvents or the like can be achieved.

[0022] The temporary carrier of the security element transfer material according to the first aspect of the invention can, in the simplest case, be in the form of a single plastic film, e.g., a polyethylene terephthalate (PET) film. According to a preferred embodiment, however, the temporary carrier can also be based on a carrier layer composite, based on WO 2010 / 031543 A1, comprising a first and a second temporary carrier substrate that are permanently bonded together by means of an adhesive layer.

[0023] In addition, the outline shapes of the security elements in the security element layer composite can be pre-cut.

[0024] A delamination-resistant plastic film / plastic layer composite film is used in the inventive security element transfer material according to the second aspect of the present invention, as defined in claim 8, which is explained in more detail in the following description: The security element transfer material contains, as a temporary carrier substrate, a plastic film provided with a plastic layer produced by coextrusion with high adhesion to the plastic film. The security element transfer material further contains a security element layer composite comprising a feature layer, a permanent carrier substrate, and an adhesive layer suitable for bonding the transfer element to a valuable object. The plastic film of the temporary carrier substrate is, for example, a polyester film such as a polyethylene terephthalate (PET) film.The plastic layer with high adhesion produced by coextrusion is based, for example, on polyethylene naphthalate (PEN) to which a certain amount of polyethylene terephthalate (PET) is added.

[0025] The security element transfer material according to the second aspect of the invention is particularly suitable for obtaining a patch-shaped security element covering a recess in the value document.

[0026] When bonding the transfer element to a valuable object, the release or detachment within the security element transfer material according to the second aspect of the invention takes place at the interface between the plastic layer produced by coextrusion and the security element layer composite arranged thereon.

[0027] The security element transfer material according to the second aspect of the invention is advantageous compared to the security element transfer materials known in the prior art because excessive penetration of the punching knife or laser radiation into the security element layer composite during the step of cutting the outline shapes of the security elements can be avoided. Furthermore, the structure of the security element transfer material according to the second aspect of the invention is advantageous compared to the security element transfer material known from WO 2010 / 031543 A1 because fewer production steps and bonding steps are required, and a film can be dispensed with.

[0028] The following comments are of a general nature and relate to both the security element transfer material according to the first aspect of the invention and the security element transfer material according to the second aspect of the invention: Suitable feature layers or functional layers provide optically variable security features, for example embossed holograms, micromirror elements, sub-wavelength structures and the like. The optically variable security features are generally provided by an embossing lacquer, for example a UV embossing lacquer, with embossed microstructures and a metallization present at least in some areas. Often, further layers are present, for example protective lacquers or primers, to which the heat-sealing lacquer is then applied at the end. The heat-sealing lacquer layer can actually consist of several layers of different lacquers.

[0029] During application or final use, the patch is heated as usual, melting the heat-sealing lacquer and bonding it to the (value document) substrate. The (value document) substrate can be, for example, a paper or polymer substrate or a paper / polymer composite substrate. Heating can be applied to specific areas (i.e., an area slightly larger than the patch itself) or to the entire surface. If the temporary carrier is then separated from the (value document) substrate, the functional layers in the patch area remain on the (value document) substrate, as the heat-sealing lacquer to the paper ensures stronger adhesion than the adhesion between the temporary carrier and the functional layers.

[0030] Other preferred versions: Functional layers or feature layers:

[0031] Micromirrors, hologram structures, subwavelength structures, or (e.g., embedded) microlenses can be incorporated into the functional layers. Microlenses can be present, in particular, in combination with microimages formed in a separate plane, thus generating optically variable security features in the form of so-called moiré magnifiers, modulo mappers, tilt images, and the like. Security features based on microlenses in combination with microimages are known, for example, from WO 2006 / 087138 A1.

[0032] Micromirrors, hologram structures, etc. are usually coated with a metallization, at least in some areas, which can consist of a metal, e.g. Al or Ag, a high-refractive index coating, e.g. ZnS or TiO 2 , or a color-shifting three-layer system reflector / dielectric / absorber (e.g. an Al / SiO 2 / Cr structure). Adhesive layer, especially heat seal varnish:

[0033] The key to the heat seal lacquer is that it ensures the desired bonding during application through pressure and, if necessary, elevated temperature. The heat can melt and / or activate the lacquer. It may also be necessary to subsequently treat the heat seal lacquer with UV radiation (post-crosslinking). Carrier substrate, especially carrier film:

[0034] Thicker films are preferably used as carrier films, e.g., a 19 µm thick polyethylene terephthalate (PET) film. It must be ensured that the carrier film does not tear after the patch has been applied to the (value document) substrate. According to one variant, the carrier film used is not a single carrier film, but rather a laminated composite consisting of two films, as known from WO 2010 / 031543 A1 (e.g., a 12 µm thick film and a 19 µm thick film that are glued together). Then, during punching, only one of the two films is punched, while the second film remains undamaged. A single punched film tears more easily than a laminated composite, since the initial tear in a film requires more force than the further tearing. Application of the transfer patch to the (value document) substrate:

[0035] For a better transfer, it may be advantageous to peel the carrier film off the remaining layer composite using a sharp edge (or a wedge). Other preferred parameters:

[0036] The functional layers preferably contain embossing lacquers which typically have a total thickness in the range from 2 µm to 7 µm. Typical embossing depths can range from 100 nm to 3.5 µm, for example, depending on the structure type. The total thickness of the patch without the carrier film is preferably below 50 µm, more preferably below 30 µm, and particularly preferably below 20 µm. Typical patch dimensions are, for example, 5 mm to 35 mm wide and 5 mm to 70 mm high. The patch shape can be chosen as desired. Oval shapes are generally easier to apply than, for example, rectangular shapes. In some circumstances, a jagged edge can be advantageous. Further general comments:

[0037] The embossed structure usable according to the invention is, in particular, embossed into an embossing lacquer. In the context of the present application, the term "optically variable effect" encompasses not only holograms but also hologram-like diffraction structures, for example, structures that do not produce a defined image but rather a blurred, colored impression. Also subsumed under the term "optically variable effect" are diffraction patterns, structures with a color-shift effect, kinoforms, structures with a microlens effect, structures with isotropic or anisotropic scattering effects or with other interference effects, subwavelength structures, moth-eye structures, microlens structures, and microstructures for moiré magnifiers or modulo mappers, micromirror structures, and microprism structures.

[0038] Preferred reflective embossed structures include, for example, an interference-capable, multi-layer structure with a reflective layer (in particular a metallic reflective layer); a semitransparent (mirror) layer (which is in particular selected from the group consisting of Al, Ag, Ni, Cr, Cu, Au and an alloy of one or more of the aforementioned elements); and a dielectric layer arranged between the reflective layer and the semitransparent (mirror) layer, The color of the multilayer structure changes with the change in viewing angle.

[0039] It is possible to create a first appearance of the interference-capable, multilayer structure that is recognizable when viewed from the front in reflected light, and a second appearance of the interference-capable, multilayer structure that is recognizable when viewed from the front in transmitted light, e.g., by means of cutouts in the reflective layer and / or the semitransparent layer. Such a film security element with different reflected / transmitted light appearances is known from WO 2009 / 149831 A2. For example, the semitransparent layer can have a plurality of cutouts arranged in a grid-like manner, which together form a character, an image, or a pattern. The pattern created in this way is visible in reflected light and disappears in transmitted light.Alternatively and / or additionally, a different incident light / transmitted light appearance of the multilayer structure can be achieved by combining the structure with a relief structure, in particular a diffractive relief structure, a micro-optical relief structure or a sublambda structure.

[0040] Further preferred reflective embossed structures contain, for example, a multi-layer structure with two semi-transparent layers and a dielectric layer arranged between the two semi-transparent layers, wherein the multi-layer structure has different color tones when viewed in reflected light on the one hand and when viewed in transmitted light on the other, in particular appears gold-colored when viewed in reflected light and displays a blue color when viewed in transmitted light. The two different color tones are, in particular, complementary colors. Such a multi-layer structure is based, in particular, on two semi-transparent mirror layers and a dielectric layer arranged between the two semi-transparent mirror layers. Such a multi-layer structure, which appears gold-colored when viewed in reflected light and displays a blue color when viewed in transmitted light, is known, for example, from WO 2011 / 082761 A1.A particularly suitable semitransparent mirror layer is a metal selected from the group consisting of Al, Ag, Ni, Cr, Cu, Au, and an alloy of one or more of the aforementioned elements, with Al or Ag being preferred as a semitransparent mirror layer, and Al being particularly preferred. Suitable multilayer structures with two semitransparent mirror layers and a dielectric layer arranged between the two semitransparent mirror layers preferably have the following physical properties: . the two semi-transparent mirror layers are preferably selected from Al or Ag; the dielectric layer is in particular a SiO 2 layer; in the case that each of the two semi-transparent mirror layers is based on Al, the respective preferred layer thickness is in a range from 5 nm to 20 nm, particularly preferably in a range from 10 nm to 14 nm; the dielectric SiO 2 layer preferably has a layer thickness in a range from 50 nm to 450 nm, further preferably in a range from 80 nm to 260 nm, with the ranges from 80 nm to 100 nm and from 220 nm to 240 nm being particularly preferred for providing a gold / blue color change; in the case that each of the two semi-transparent mirror layers is based on Ag, the respective preferred layer thickness is in a range from 15 nm to 25 nm;the dielectric SiO 2 layer preferably has a layer thickness in a range of 50 nm to 450 nm, more preferably in a range of 80 nm to 260 nm, with the ranges of 80 nm to 100 nm and 220 nm to 240 nm being particularly preferred for providing a gold / blue color change. ;

[0041] The multi-layered coating structures mentioned above not only enable the creation of a semi-transparent functional layer that appears gold-colored when viewed in incident light and shows a blue hue when viewed in transmitted light, but depending on the choice of layer thickness, especially of the dielectric layer, further color changes can be created, e.g. In reflected light, magenta; in transmitted light, blue-green; in reflected light, turquoise; in transmitted light, orange-yellow; in reflected light, gold; in transmitted light, blue-violet; in reflected light, silver; in transmitted light, violet.

[0042] Further preferred reflective embossed structures contain, for example, a liquid crystal layer that displays a different color when viewed in reflected light than when viewed in transmitted light. Alternatively and / or additionally, a different reflected / transmitted light appearance can be achieved by combining the liquid crystal layer with a relief structure, in particular a diffractive relief structure, a micro-optical relief structure, or a sublambda structure.

[0043] Further preferred reflective embossed structures contain, for example, a printing layer with an effect pigment composition that displays a different color when viewed in reflected light than when viewed in transmitted light, in particular a gold / blue color change, a gold / violet color change, a green / gold / magenta color change, a violet / green color change, or a silver / opaque color change. Such printing inks are described, for example, in WO 2011 / 064162 A2. Alternatively and / or additionally, a different reflected / transmitted light appearance can be achieved by combining the printing layer with a relief structure, in particular a diffractive relief structure, a micro-optical relief structure, or a sublambda structure.

[0044] The relief structure forming a diffractive structure is, in particular, a hologram structure. The dimensions of the structural elements of the diffractive structure are preferably in the order of magnitude of the light wavelength, more preferably in a range greater than 100 nm and less than 1 µm, with a range greater than 300 nm and less than 1 µm being particularly preferred.

[0045] The relief structure forming a micromirror arrangement is also referred to herein as a micro-optical relief structure. The production of a micro-optical relief structure is known in the prior art (see, for example, WO 2014 / 060089 A2). The dimensions of the structural elements of the micromirror arrangement are preferably in a range greater than 1 µm and less than 40 µm, with a range greater than 1 µm and less than 30 µm being particularly preferred. The dimensions of the structural elements of the micromirror arrangement have, for example, a height of up to 15 µm and a lateral extent of up to 30 µm. Both the height and the lateral extent of the structural elements of the micromirror arrangement are preferably greater than 1 µm.

[0046] Further preferred micro-optical relief structures are known, for example, from WO 2007 / 079857 A1. Here, the reflective microstructure has the form of a mosaic composed of a plurality of reflective mosaic elements characterized by the parameters of size, outline shape, relief shape, reflectivity, and spatial orientation. These mosaic elements form a predetermined motif in which different groups of mosaic elements with different characteristic parameters reflect incident light into different spatial regions. The mosaic elements have a lateral dimension below the resolution limit of the eye.

[0047] Further embodiments and advantages of the invention are explained below with reference to the schematically highly simplified figures, in which a true-to-scale and true-to-proportion reproduction has been omitted in order to increase clarity.

[0048] They show: Figures 1 to 4 show an exemplary embodiment for the use of a security element transfer material according to the invention in accordance with the first aspect of the invention; Figures 5 to 8 show an exemplary embodiment for the use of a security element transfer material according to the invention in accordance with the second aspect of the invention; and Figure 9 shows a value document provided with two security elements, in this example a banknote, wherein the security elements are transfer patches, each of which has been produced from the security element transfer material according to the invention in accordance with the first aspect of the invention or from the security element transfer material according to the invention in accordance with the second aspect of the invention.

[0049] The Figure 9shows a value document 33, in the example a paper banknote with the denomination "20". The paper substrate 36 of the banknote 33 is provided with two security elements 34 and 35, in the example each a patch. The patch 34 is produced from the inventive security element transfer material according to the first aspect of the invention. The paper substrate 36 of the banknote 33 is completely covered by the patch 34 in the area of ​​the patch-shaped security element 34. The further patch 35 is produced from the inventive security element transfer material according to the second aspect of the invention. The paper substrate 36 of the banknote 33 has a square recess 37 within the area of ​​the patch-shaped security element 35, e.g., obtainable by punching or laser cutting. The recess 37 in the paper 36 is thus covered or closed on one side by the patch 35.

[0050] The Figures 1 to 4illustrate an embodiment of the use of a security element transfer material according to the first aspect of the invention, which is used, for example, for providing the patch-shaped security element 34 in the Figure 9 is suitable.

[0051] The Figure 1 shows a security element transfer material 1, which contains a carrier material (= temporary carrier) containing layers 2, 3 and 4 and an upper material containing layers 5, 6, 7, 8 and 9. The dashed line AA' shows the area at which the upper material is later detached from the temporary carrier during the application of the upper material (i.e. the security element or transfer element to be applied to the value document) to a value document.

[0052] The security element transfer material 1 comprises a coextruded film, i.e., a composite film composed of a polyethylene terephthalate (PET) film 4 with a thickness of 19 µm and a plastic layer 5 based on a foreign plastic material, in this example, pure polyethylene naphthalate (PEN). The coextruded film comprising layers 4 and 5 is a plastic film / plastic layer composite film prone to delamination along the imaginary line AA'. The coextruded film comprising layers 4 and 5 was subsequently permanently bonded to another polyethylene terephthalate (PET) film 2 with a thickness of 12 µm by means of an adhesive layer 3. A UV embossing lacquer layer 6 provided with microstructures and / or nanostructures was then applied above the plastic layer 5 (the embossed structures are not shown in the figure).The UV embossing lacquer layer 6 was subsequently provided with a metallization 7, which is formed in the form of a pattern or in the form of characters. The metallization 7 contains recesses that form a so-called negative writing. The metallization 7 can be provided, for example, by means of a washing process known in the prior art, see, for example, EP 1 972 462 A2. A primer layer 8, which actually serves as a leveling protective lacquer, was then applied above the metallization 7. Finally, an adhesive layer 9 suitable for bonding to a valuable document, namely a heat-sealing lacquer layer, was applied above the primer layer 8.

[0053] The Figure 2The lines 11 shown indicate how the security element layer composite is cut to pre-cut the security elements in their outline shapes. Cutting can be done using a punch or a suitable laser, e.g., a CO2 laser. As can be seen, the cuts 11 penetrate the plastic film 4 of the temporary carrier. The plastic film 4 is destabilized by the cuts 11 and can easily tear at the locations of the cuts in the event of slight stretching, which is practically unavoidable during the transfer process of the security elements.

[0054] Subsequently, the excess material of the security element layer composite (in the cross-sectional view according to the Figure 2 The material outside the cuts 11) is removed in the so-called "weeding" step, which creates gaps in the security element layer composite. This state is Figure 3The polyethylene naphthalate (PEN)-based plastic layer 5, produced by coextrusion and with minimal adhesion to the temporary carrier substrate 4, facilitates the removal of excess material. Security elements 14 are located on both sides of the gap. The temporary carrier is designated by reference number 13. The security elements 14 form what are effectively islands arranged on the temporary carrier 13. Figure 3 shows the security element transfer material according to the invention as an endless belt in which only one security element 14 is located in the width direction. In practice, the endless belts can be wider and comprise a plurality of security elements 14 arranged side by side.

[0055] The Figure 4shows the security element 14 after transfer from the security element transfer material to a security paper 16. The security element 14 is bonded to the security paper substrate 16 of a value document by means of the adhesive layer 9. Above the adhesive layer 9 is the primer layer 8, followed by the metallization 7, which has recesses and thus forms a pattern or character, and the UV embossing lacquer layer 6. The plastic layer 5, which is arranged as the uppermost layer and is produced by coextrusion and based on polyethylene naphthalate (PEN), serves as a protective layer. In this way, excellent protection of the sensitive security element layer composite can be achieved against mechanical damage, e.g., in banknote circulation, or against chemical damage caused by solvents or the like.

[0056] The Figures 5 to 8illustrate an embodiment of the use of a security element transfer material according to the second aspect of the invention, which is used, for example, for providing the patch-shaped security element 35 in the Figure 9 The paper substrate 36 of the banknote 33 has a square recess 37 within the area of ​​the patch-shaped security element 35, which can be obtained, for example, by punching or laser cutting. The recess 37 in the paper 36 is thus covered or closed on one side by the patch 35.

[0057] The Figure 5shows a security element transfer material 17, which contains a carrier material (= temporary carrier) containing layers 18 and 19 and an upper material containing layers 20, 21, 22, 23, 24, and 25. The dashed line AA' represents the area at which the upper material is later detached from the temporary carrier during the application of the upper material (i.e., the security element or transfer element to be applied to the value document) to a value document.

[0058] The security element transfer material 17 comprises a coextruded film, i.e., a composite film made of a polyethylene terephthalate (PET) film 18 with a thickness of 19 µm and a plastic layer 19 based on polyethylene naphthalate (PEN), to which a certain amount of polyethylene terephthalate (PET) is admixed. The layers 18 and 19 form a plastic film / plastic layer composite film that is stable against delamination. A UV embossing lacquer layer 20 was then applied, which is provided with microstructures and / or nanostructures (the embossed structures are not shown in the figure). The UV embossing lacquer layer 20 was then provided with a metallization 21 in the form of a pattern or in the form of characters. The metallization 21 contains recesses that form a so-called negative writing. The metallization 21 can be provided, for example, by means of a washing process known in the prior art, see, for example,EP 1 972 462 A2. A primer layer 22, which actually serves as a leveling protective lacquer, was then applied above the metallization 21. Finally, a stationary carrier substrate 24, namely a polyethylene terephthalate (PET) film, and an adhesive layer 25, namely a heat-sealing lacquer layer suitable for bonding to a valuable document, were applied above the primer layer 22 by means of an adhesive layer 23.

[0059] The Figure 6 The lines 27 shown indicate how the security element layer composite is cut to pre-cut the security elements in their outline shapes. Cutting can be done using a punch or a suitable laser, e.g., a CO2 laser. As can be seen, the cuts 27 penetrate the plastic layer 19 produced by coextrusion, but not the plastic film 18 of the temporary carrier.

[0060] Subsequently, the excess material of the security element layer composite (in the cross-sectional view according to the Figure 6 the material outside the cuts 27) is removed in the so-called "weeding" step, which creates gaps in the security element layer composite. This state is Figure 7 The plastic layer 19, based on polyethylene naphthalate (PEN) with admixed polyethylene terephthalate (PET), is produced by coextrusion and has high adhesion on the carrier substrate 18. It serves as a release layer and facilitates the removal of excess material. Security elements 30 are located on both sides of the gap. Reference number 29 designates the temporary carrier. The security elements 30 form what are effectively islands arranged on the temporary carrier 29.

[0061] Figure 7shows the security element transfer material according to the invention as an endless belt in which only one security element 30 is located in the width direction. In practice, the endless belts can be wider and comprise a plurality of security elements 30 arranged side by side.

[0062] The Figure 8shows the security element 30 after transfer from the security element transfer material to a security paper 32. The security element 30 is bonded to the security paper substrate 32 of a value document by means of the adhesive layer 25. The paper substrate 32 of the banknote 33 has a recess within the area of ​​the patch-shaped security element 30, which can be achieved, for example, by punching or laser cutting. Located above the adhesive layer 25 are the stationary carrier substrate 24, the adhesive layer 23, the primer layer 22, followed by the metallization 21 having recesses and thus forming a pattern or character, and the UV embossing lacquer layer 20 as a topmost layer.

Claims

1. Security element transfer material (1) comprising - a security element laminate comprising a multiplicity of layers, including at least an adhesive layer (9), a feature layer (6; 7) and a viewing layer (5), the viewing layer being the layer which, after transfer of a security element (34) to a value article (33), faces a viewer, and - a temporary carrier which is removably connected to the viewing layer (5) of the security element laminate, wherein - the temporary carrier comprises at least a first temporary carrier substrate (4), specifically a plastics film, characterized in that - the viewing layer (5) of the security element laminate is in the form of a plastics layer, generated on the first temporary carrier substrate (4) by coextrusion, with little adhesiveness on the first temporary carrier substrate (4).

2. Security element transfer material (1) according to Claim 1, characterized in that the first temporary carrier substrate (4) is a polyethylene terephthalate (PET) film and the viewing layer (5) of the security element laminate, which is in the form of a plastics layer, generated on the first temporary carrier substrate (4) by coextrusion, with little adhesiveness on the first temporary carrier substrate (4), is a polyethylene naphthalate (PEN) layer.

3. Security element transfer material (1) according to Claim 1 or 2, characterized in that the temporary carrier comprises a carrier laminate which consists of a first (4) and a second (2) temporary carrier substrate, which are in each case a plastics film and are bonded indissolubly by means of a layer (3) of adhesive.

4. Security element transfer material (1) according to any of Claims 1 to 3, characterized in that outline shapes of the security elements are precut in the security element laminate.

5. Security element transfer material (1) according to Claim 4 with reference to Claim 3, characterized in that outline shapes of the security elements are precut in the security element laminate, where the cuts (11) optionally sever the first temporary carrier substrate (4) partially or completely and optionally sever the layer (3) of adhesive partially or completely but do not penetrate into the second temporary carrier substrate (2), so that the temporary carrier can be removed as a complete carrier laminate.

6. Security element transfer material (1) according to Claim 4 or 5, characterized in that the laminate material outside the outline shapes of the security elements is removed from the security element laminate, so that the security element transfer material has gaps in the security element laminate, while the temporary carrier has no gaps.

7. Security element transfer material (1) according to any of Claims 1 to 4, characterized in that the feature layer comprises an embossing varnish layer (6) and a metallization or a coloured thin-layer element (7).

8. Security element transfer material (17) comprising - a security element laminate which comprises a multiplicity of layers, including at least an adhesive layer (25), a feature layer (20; 21) and a permanent carrier substrate (24), the feature layer (20; 21) being identical to a viewing layer and the viewing layer being the layer which, after transfer of a security element (35) to a value article (33), faces a viewer, and - a temporary carrier which is removably connected to the viewing layer of the security element laminate, wherein - the temporary carrier comprises a carrier substrate (18), specifically a plastics film, and a plastics layer (19), generated on the carrier substrate (18) by coextrusion, with high adhesiveness on the carrier substrate (18); and - the viewing layer of the security element laminate is removably connected to the plastics layer (19) generated on the carrier substrate (18) by coextrusion.

9. Security element transfer material (17) according to Claim 8, characterized in that the carrier substrate (18) of the temporary carrier is a polyethylene terephthalate (PET) film and the plastics layer (19), generated on the carrier substrate (18) by coextrusion, with high adhesiveness on the carrier substrate (18), is a polyethylene naphthalate (PEN) layer with admixed polyethylene terephthalate (PET).

10. Security element transfer material (17) according to either of Claims 8 and 9, characterized in that outline shapes of the security elements are precut in the security element laminate.

11. Security element transfer material (17) according to either of Claims 8 and 9, characterized in that outline shapes of the security elements are precut in the security element laminate, where the cuts optionally sever the plastics layer (19), generated on the carrier substrate (18) by coextrusion, with high adhesiveness on the carrier substrate (18), partially or completely but do not penetrate into the carrier substrate (18) of the temporary carrier, so that the temporary carrier can be removed as a complete carrier laminate.

12. Security element transfer material (1) according to any of Claims 8 to 11, characterized in that the feature layer comprises an embossing varnish layer (20) and a metallization or a coloured thin-layer element (21).

13. Security element transfer material (1, 17) according to either of Claims 7 and 12, characterized in that the coloured thin-layer element (7, 21) is a colour-flopping thin-layer element which conveys different colours to the viewer at different viewing angles, or a semi-transparent thin-layer element which conveys different colours to the viewer when viewed in reflected light and when viewed in transmitted light.

14. Use of a security element transfer material (1, 17) according to any of Claims 1 to 13 to safeguard a value article, more particularly a value document (33), with a security element (34, 35).

15. Use according to Claim 14 with reference to any of Claims 8 to 13, characterized in that the value article is a value document (33) having a through-opening (37) and the security element (35) is applied such that it masks the through-opening (37).

16. Method for producing a security element transfer material (1) according to any of Claims 1 to 7, comprising - providing a carrier substrate (4), specifically a plastics film provided with a plastics layer (5) generated by coextrusion, where the plastics layer (5), generated on the carrier substrate (4) by coextrusion, has little adhesiveness on the carrier substrate (4); and - arranging a security element laminate comprising at least an adhesive layer (9) and a feature layer (6; 7) on the plastics layer generated by coextrusion.

17. Method for producing a security element transfer material (17) according to any of Claims 8 to 12, comprising - providing a carrier substrate (18), specifically a plastics film provided with a plastics layer (19) generated by coextrusion, where the plastics layer (19), generated on the carrier substrate (18) by coextrusion, has high adhesiveness on the carrier substrate (18); and - arranging a security element laminate comprising at least an adhesive layer (25) and a feature layer on the plastics layer generated by coextrusion.