EP3363652B2 - Security element transfer material and method for manufacturing the same - Google Patents

Description

The invention relates to a security element transfer material, comprising: a security element layer composite which has a plurality of layers, which include at least one feature layer that has an optically variable effect and an adhesive layer, the feature layer being the layer that is applied after a security element has been transferred a value document substrate faces a viewer; a carrier substrate which is separably connected to the feature layer of the security element layer composite; a mask layer having at least one recess, which is designed such that the security element layer composite is bonded to the value document substrate in the area of the at least one recess in the mask layer by the action of pressure and, if necessary, heat using the adhesive layer and can then be detached from the carrier substrate, in the area Outside the at least one recess in the mask layer, sticking of the security element layer composite to the value document substrate and subsequent detachment of the security element layer composite from the carrier substrate is prevented. The invention further relates to methods for producing the security element transfer material.

Valuable items, such as branded items or valuable documents, especially banknotes, are often equipped with security elements that allow the authenticity of the valuable item to be checked and at the same time serve as protection against unauthorized reproduction. The security elements used for this are often not provided individually, but in the form of transfer tapes with a large number of security elements designed as transfer elements. A characteristic feature of transfer tapes is that the security elements are prepared on a carrier layer, whereby the order of the layers of the transfer elements must be reversed to that which will later be present on the object to be protected. During transfer, the carrier layer is typically removed from the layer structure of the security elements. 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 placed on the object with the heat-sealing adhesive layer and pressed using a heated transfer stamp or a transfer roller and transferred to the object in the outline shape of the heated transfer stamp. Transfer elements, transfer belts and the transfer of transfer elements on target substrates are, for example, in the EP 0 420 261 B1 and the WO 2005/108108 A2 described.

In practice it has been shown that, especially when using more stable and/or flexible UV embossing varnishes, transfer elements, e.g. transfer patches, do not tear off cleanly at the boundary of the heated area. This leads to unclean edges and possibly also to the fact that remnants of the film composite that have been torn from the layer composite in the non-glued area get stuck on the transferred patches. These residues are undesirable because they later dissolve and impair subsequent processing steps, e.g. printing processes, in the form of contamination.

Instead of the transfer elements being shaped by the transfer stamp during the transfer process, the individual transfer elements can also be prefabricated on the transfer belt in the desired outline shape. The prefabrication of separate individual security elements makes sense, for example, if the security elements have a layer structure that makes it difficult to precisely cut through the entire layer structure during the transfer process. This is the case, for example, if the layer structure of the security element to be transferred contains a permanent carrier substrate, for example a plastic film. Carrier substrates within the layer structure of security elements are useful if the security elements have to be made particularly stable, for example if 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 size of the opening to be closed, high demands can be placed on the stability of the security elements. Banknotes, for example, are subjected to high stress during their life in circulation, are worn, bent and may be exposed to moisture. The security elements must be able to withstand these stresses just as much as the banknote paper itself, otherwise there would be a risk that the continuous opening in the banknote would be exposed after a certain circulation time.

Security elements whose layer structure includes a stable carrier substrate, typically a plastic film, must be present on a transfer material as prefabricated individual elements, which means that the outline shapes of the security elements must be pre-cut in the security element material. The pre-cutting can be carried out using a laser, for example.

The problem that arises is that the cutting depth must be controlled very precisely in order, on the one hand, to cut through the entire layer structure of the security element, but on the other hand not to injure the carrier material that is separated during the transfer. Plastic films are usually used as carrier materials. Although plastic films have a high tear resistance, they have a low tear resistance. If they are cut, it can hardly be avoided that the security element transfer material, which is in the form of an endless material, tears 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 cut or the carrier films not to be cut are materials with thicknesses in the micrometer range. The security element layer structures typically have thicknesses in the range of approximately 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 problematic 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 precise and smooth application of the security elements made of the endless material to the products to be protected is no longer guaranteed.

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 products to be secured without the risk of tearing of the carrier material, is from the WO 2010/031543 A1 known. The security element transfer material is an endless material, in particular a band with a length of several hundred meters and a width of a few millimeters/centimeters to several meters. The security element transfer material has a security element layer composite, ie the actual security element material, and a temporary carrier, ie the material on which the security elements are "stocked". The temporary carrier is based on a carrier layer composite, consisting of a first and a second temporary carrier substrate, which are permanently bonded using an adhesive layer. The security element layer composite is connected to a temporary carrier either directly or by means of 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 valuable item. The temporary carrier is located on the side of the security element layer composite, which faces a viewer after the security elements have been transferred. The term “temporary” carrier substrates expresses the fact that, in contrast to the “permanent” carrier substrate, these carrier substrates are not part of the security elements. The design of the temporary carrier as a carrier layer composite prevents the stability of the temporary carrier from being impaired by cutting the temporary carrier when cutting the outline shapes of the security elements. A comparable result cannot be achieved simply by making a single temporary carrier film correspondingly thicker, since plastic films have a low resistance to tearing, that is, if a film is cut even slightly, it will easily tear further and, under certain circumstances, completely. This is different with the carrier layer composite, consisting of a first and a second temporary carrier substrate, which are inextricably bonded by means of an adhesive layer: even if one of the temporary carrier substrates is completely severed, the further temporary carrier substrate (or, if applicable, the further temporary carrier substrates) generally remains undamaged and therefore stable. The adhesive also forms an additional “buffer zone” between the temporary carrier substrates.

The ones in the the WO 2010/ 031543 A1 The method described consists of weeding patch films before application. To do this, the shapes of the patch are punched into the layers to be transferred using a punch, ie 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. However, a disadvantage of this process is that the layer structure must have sufficient stability for weeding, which can be done, for example, by introducing a stabilizing film layer. However, this is again associated with an increase in the thickness of the finished patch, which is undesirable in practice.

The WO 2010/072339 A2 and the WO 2012/164011 A1 each describe a method for producing a security element and a transfer film.

The patent US 4,246,307 describes a laminated sticker and a laminated ID card, each with tamper protection, with the attempt to detach the Laminate would lead to tearing of a back layer in certain places.

The invention is based on the object of providing a method for transferring a transfer element, for example a transfer patch, in which, on the one hand, a small thickness of the finished patch and, on the other hand, a reliable transfer of the patch with clean edges can be achieved.

This task is achieved by the combination of features defined in the main claim 1 and in the independent independent claims 5 and 6. Further training is the subject of the dependent claims.

Summary of the invention

(First Aspect of the Invention) Security element transfer material according to claim 1.

The carrier substrate of the security element transfer material is in particular a film. The carrier substrate of the security element transfer material can also be a carrier layer composite, consisting of a first film and a second film, which are permanently bonded using an adhesive layer.

(Second Aspect of the Invention) Method for producing a security element transfer material according to claim 5.

(Third aspect of the invention) A method of producing a security element transfer material according to claim 6.

Detailed description of the invention

For the purposes of this invention, viewing in incident light means illuminating the document of value from one side and viewing the document of value from the same side Page. Viewing in incident light occurs, for example, when the front of the document of value is illuminated and also viewed.

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

A document of value within the meaning of the invention can be, for example, banknotes or identification documents, but also stocks, certificates, stamps, checks, admission tickets, tickets, airline tickets, ID cards, visa stickers or the like, as well as labels, seals, packaging or other elements. The simplified term “document of value” therefore always includes documents of the type mentioned below. The term document of value also includes security paper for the production of banknotes. The term banknote includes in particular a paper banknote, a polymer banknote or a film composite banknote.

The transfer element, i.e. the security element to be transferred, can in particular be 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 is therefore not to be construed as being limited to a patch.

Instead of the term feature layer, the term functional layer is also used herein. The functional layer can be a single (functional) layer or multiple (functional) layers.

Instead of the phrase “a mask layer having at least one recess,” the term shadow mask is also used herein.

Transfer patches are used, for example, in the first series of EURO banknotes, e.g. in the form of the hologram patch applied to the EURO 50 banknote.

According to the invention, a transfer material can be realized according to the following preferred embodiment:

1. Provision of a transfer film structure:

The starting point is a normal transfer film structure, such as the one used for applying transfer strips. Such a structure is based on a carrier film, one or more functional layers on it and a heat-sealing lacquer layer. The functional layers provide optically variable security features, for example embossed holograms, micromirror elements, subwavelength structures and the like. The optically variable security features are usually provided by an embossing varnish, e.g. a UV embossing varnish, with microstructures embossed therein and metallization present at least in some areas. There are often additional layers here, e.g. protective varnish or primer, which is then followed by the heat sealing varnish at the end. The heat seal lacquer layer can actually consist of several layers of different lacquers. The functional layers have only weak adhesion to the carrier film, which can be achieved, for example, by poor adhesion of the embossing varnish to the carrier film or by introducing a special separating layer.

2. Applying a shadow mask:

According to the invention, a shadow mask is applied to the transfer film structure mentioned above. The perforated mask can in particular be provided by a perforated film from which the shapes of the desired patches are punched out. Such a perforated film is advantageously laminated or glued onto the transfer film structure. This can be done with a laminating adhesive or simply by using the adhesive power of the existing heat sealing lacquer. The side facing the heat sealing lacquer can advantageously be provided with a primer beforehand, which enables better bonding of the perforated film and functional layers. Perforated film and functional layers can also only be glued in certain areas. Theoretically, the perforated film can only stick to the functional layers when the heat sealing lacquer melts during application. In practice, however, it is advantageous to prevent the perforated film from slipping by gluing it at least in certain areas.

3. Application:

During application, the patch is heated as usual, whereby the heat sealing lacquer melts and sticks to the (value document) substrate. The (document of value) substrate can be, for example, a paper or polymer substrate or a paper/polymer composite substrate.

The heating can take place in certain areas (i.e. in an area that is slightly larger than the patch itself) or over the entire area. If you then separate the film structure from the (value document) substrate, the functional layers remain in the patch area on the (value document) substrate, since the heat sealing lacquer to the paper ensures a stronger adhesion than the adhesion between the carrier film and functional layers. In the area outside the patch, the functional layers remain on the carrier film.

1. i) Verhinderung des Verklebens von Funktionsschichten und (Wertdokument-)Substrat.
2. ii) Stabilisierung des Schichtverbunds zur Verhinderung des Aufreißens der Funktionsschicht in Bereichen außerhalb des Patches.

The mask film fulfills two tasks:

1. i) Prevention of sticking of functional layers and (value document) substrate.
2. ii) Stabilization of the layer composite to prevent the functional layer from tearing in areas outside the patch.

Further preferred embodiment variants:

Alternative method of deploying the shadow mask:

Instead of laminating a finished perforated mask onto the transfer composite (see the preferred embodiment above, whereby the lamination is usually registered or precisely registered), the corresponding film can also be perforated only after lamination. To do this, the film is only glued to the transfer film in the areas outside of the later patch (by melting or activating the heat sealing lacquer or using a laminating adhesive applied in areas). Due to the positioning tolerances of bonding and punching-cutting, it is advantageous to end the bonding with sufficient distance from the patch. The patch shapes are then punched out and the film in the areas of the holes is removed, for example using compressed air or by pulling over a sharp edge. A significant advantage of this variant is that the patches do not have to be torn out of the functional layer composite after application to the (value document) substrate (i.e. a break must occur within the functional layers), but the functional layers on the edge of the patch are already clean by punching are severed. This results in very clean patch edges.

Further preferred embodiment variants:

Functional layers:

For example, micromirrors, hologram structures, subwavelength structures or (eg embedded) microlenses can be incorporated into the functional layers. Microlenses can be present in particular in combination with microimages formed in a separate plane and in this way generate optically variable security features in the form of so-called Moire magnifiers, modulo mappers, tilt images and the like. Security features based on microlenses in combination with microimages are, for example, from WO 2006/087138 A1 known.

Micromirrors, hologram structures, etc. are usually coated with a metallization that is present 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 TiO2, or a color-shifting three-layer system reflector/dielectric/absorber (e.g. an Al/SiO2/Cr -Construction).

Heat sealing lacquer:

What is important for the heat seal gel varnish is that at the end it ensures the desired bonding through pressure and, if necessary, increased temperature. The heat can cause it to melt and/or be activated. It can also be provided that the heat sealing lacquer is then post-treated, for example using UV radiation (post-crosslinking).

Film thicknesses:

The perforated film is preferably as thin as possible. Films with thicknesses in a range from 4.5 µm to 19 µm can advantageously be used. As a foil preferably a polyethylene terephthalate (PET) film is used. Thicker films are preferably used as carrier films, for example a 19 µm thick PET film. In the embodiments in which the functional layers are punched using punching, something is usually also punched into the carrier film. It must be ensured that the carrier film does not tear after the patch has been applied to the (document of value) substrate. According to an advantageous variant, the carrier film used is not a single carrier film, but rather a laminating composite consisting of two films, as described in WO 2010/031543 A1 is known (e.g. a 12 µm thick film and a 19 µm thick film that are glued together): then only one of the two films is punched during punching, while the second film remains undamaged. A single die-cut film tears more easily than a laminated composite, as "tearing" a film requires more force than tearing further.

Application of the transfer patch to the (value document) substrate:

For better transfer, it can be advantageous to pull the carrier film away from the remaining layer composite using a sharp edge (or a wedge).

Other preferred parameters:

• Die Gesamtdicke des Patches ohne Trägerfolie liegt bevorzugt unterhalb von 50 µm, weiter bevorzugt unterhalb von 30 µm und insbesondere bevorzugt unterhalb von 20 µm.
• Typische Patch-Abmessungen liegen bei einer Breite von z.B. 5 mm bis 25 mm und Höhen von z.B. 5 mm bis 70 mm.
• Die Patch-Form kann beliebig gewählt werden. Ovale Formen sind in der Regel einfacher zu applizieren als z.B. rechteckige Formen. Unter Umständen kann ein gezackter Rand von Vorteil sein. Insbesondere die Variante des Stanzens der Funktionsschichten (siehe oben) ermöglicht auch die Applikation von Patches mit komplexen Umrissformen, die unter normalen Bedingungen schwer zu applizieren sind.

The functional layers preferably contain embossing varnishes, which typically have a total thickness in a range of 2 μm to 7 μm. Depending on the structure type, typical embossing depths can be in a range of, for example, 100 nm to 3.5 µm.

• The total thickness of the patch without a 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 25 mm wide and eg 5 mm to 70 mm high.
• The patch shape can be chosen arbitrarily. Oval shapes are generally easier to apply than, for example, rectangular shapes. In some circumstances, a jagged edge can be advantageous. In particular, the variant of punching the functional layers (see above) also enables the application of patches with complex outline shapes that are difficult to apply under normal conditions.

Further general comments:

The embossing structure that can be used according to the invention is in particular embossed into an embossing varnish. In the context of the present application, the term “optically variable effect” includes not only holograms but also hologram-like diffraction structures, for example structures that do not produce a defined image but rather a blurry 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 moire magnifiers or modulo mappers , micromirror structures and microprism structures.

• einer reflektierenden Schicht (insbesondere einer metallischen, reflektierenden Schicht);
• einer semitransparenten (Spiegel-)Schicht (die insbesondere von der Gruppe bestehend aus Al, Ag, Ni, Cr, Cu, Au und einer Legierung eines oder mehrerer der vorstehend genannten Elemente gewählt ist); und
• einer zwischen der reflektierenden Schicht und der semitransparenten (Spiegel-) Schicht angeordneten dielektrischen Schicht,

wobei sich die Farbe des mehrschichtigen Aufbaus mit der Änderung des Betrachtungswinkels ändert.Preferred reflective embossed structures contain, for example, an interference-capable, multi-layer structure

• a reflective layer (in particular a metallic reflective layer);
• a semi-transparent (mirror) layer (selected in particular from the group consisting of Al, Ag, Ni, Cr, Cu, Au and an alloy of one or more of the above-mentioned elements); and
• a dielectric layer arranged between the reflective layer and the semi-transparent (mirror) layer,

where the color of the multi-layer structure changes as the viewing angle changes.

It is possible to create a first appearance of the interference-capable, multi-layer structure that can be seen when the front side is viewed in reflected light and a second appearance of the interference-capable, multi-layer structure that can be seen when the front side is viewed in transmitted light, for example through recesses in the reflective layer and/or the semi-transparent layer Layer. Such a film security element with different reflected light/transmitted light appearance is from the WO 2009/149831 A2 known. For example, the semi-transparent layer can have a large number of recesses arranged in a grid-like manner, which as a whole 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 reflected light/transmitted light appearance of the multilayer structure can be achieved be that the structure is combined with a relief structure, in particular a diffractive relief structure, a micro-optical relief structure or a sublambda structure.

• die beiden semitransparenten Spiegelschichten werden bevorzugt von Al oder Ag gewählt; die dielektrische Schicht ist insbesondere eine SiO2 -Schicht;
• im Falle, dass jede der beiden semitransparenten Spiegelschichten auf Al beruht, liegt die jeweilige bevorzugte Schichtdicke in einem Bereich von 5 nm bis 20 nm, insbesondere bevorzugt in einem Bereich von 10 nm bis 14 nm; die dielektrische SiO2-Schicht hat vorzugsweise eine Schichtdicke in einem Bereich von 50 nm bis 450 nm, weiter bevorzugt in einem Bereich von 80 nm bis 260 nm, wobei die Bereiche von 80nm bis 100nm und von 220nm bis 240nm speziell für die Bereitstellung eines Gold/Blau-Farbwechsels besonders bevorzugt werden;
• im Falle, dass jede der beiden semitransparenten Spiegelschichten auf Ag beruht, liegt die jeweilige bevorzugte Schichtdicke in einem Bereich von 15 nm bis 25 nm; die dielektrische SiO2 -Schicht hat vorzugsweise eine Schichtdicke in einem Bereich von 50 nm bis 450 nm, weiter bevorzugt in einem Bereich von 80 nm bis 260 nm, wobei die Bereiche von 80nm bis 100nm und von 220nm bis 240nm speziell für die Bereitstellung eines Gold/Blau-Farbwechsels besonders bevorzugt werden.

Further preferred reflective embossed structures include, for example, a multi-layer structure with two semi-transparent layers and a dielectric layer arranged between the two semi-transparent layers, the multi-layer structure having different color tones when viewed in reflected light on the one hand and when viewed in transmitted light on the other hand, in particular when viewed in Appears gold in reflected light and shows a blue tone when viewed in transmitted light. The two different shades are, in particular, complementary colors. Such a multilayer 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 when viewed in reflected light and shows a blue tone when viewed in transmitted light, is, for example, from the WO 2011/082761 A1 known. A metal selected from the group consisting of Al, Ag, Ni, Cr, Cu, Au and an alloy of one or more of the above-mentioned elements is particularly suitable as a semi-transparent mirror layer, with Al or Ag being preferred as a semi-transparent mirror layer and Al is particularly preferred. Suitable multilayer structures with two semi-transparent mirror layers and a dielectric layer arranged between the two semi-transparent mirror layers preferably have the following physical properties:

• the two semi-transparent mirror layers are preferably chosen from Al or Ag; the dielectric layer is in particular an SiO2 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 SiO2 layer preferably has a layer thickness in a range from 50 nm to 450 nm, more 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 specifically for providing a gold/ Blue color change is particularly preferred;
• 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 SiO2 layer preferably has a layer thickness in a range from 50 nm to 450 nm, more preferably in a range from 80 nm to 260 nm, the ranges from 80nm to 100nm and from 220nm to 240nm are particularly preferred for providing a gold/blue color change.

• im Auflicht Magenta, im Durchlicht Blau-Grün;
• im Auflicht Türkis, im Durchlicht Orange-Gelb;
• im Auflicht Gold, im Durchlicht Blau-Violett;
• im Auflicht Silber, im Durchlicht Violett.

The multi-layered layer structures mentioned not only enable the creation of a semi-transparent functional layer, which appears gold-colored when viewed in reflected light and shows a blue tone when viewed in transmitted light, but depending on the choice of layer thickness, in particular of the dielectric layer, further color changes can be created, for example

• Magenta in reflected light, blue-green in transmitted light;
• Turquoise in reflected light, orange-yellow in transmitted light;
• Gold in reflected light, blue-violet in transmitted light;
• Silver in reflected light, violet in transmitted light.

Further preferred reflective embossed structures contain, for example, a liquid crystal layer which, when viewed in reflected light, shows a different color than when viewed in transmitted light. Alternatively and/or additionally, a different reflected light/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.

Further preferred reflective embossed structures contain, for example, a print layer with an effect pigment composition which, when viewed in reflected light, shows a different color 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 used, for example, in the WO 2011/064162 A2 described. Alternatively and/or additionally, a different reflected light/transmitted light appearance can be achieved by combining the print layer with a relief structure, in particular a diffractive relief structure, a micro-optical relief structure or a sublambda structure.

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 that is greater than 100 nm and less than 1 μm, with a range greater than 300 nm and less than 1 μm being particularly preferred.

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 art (see, for example, WO 2014/060089 A2 ). The dimensions of the structural elements of the micromirror arrangement are preferably in a range that is larger than 1 μm and less than 40 μm, with a range larger 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.

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

Further exemplary embodiments and advantages of the invention are explained below with reference to the schematically greatly simplified figures, in the representation of which a reproduction true to scale and proportions was omitted in order to increase clarity.

• Figuren 1 und 2 die Herstellung eines erfindungsgemäßen Transfermaterials gemäß einem ersten Ausführungsbeispiel;
• Figuren 3 und 4 die Applikation eines Transfer-Patches auf ein Wertdokumentsubstrat;
• Figuren 5 bis 8 die Herstellung eines erfindungsgemäßen Transfermaterials gemäß einem zweiten Ausführungsbeispiel;
• Figuren 9 und 10 die Applikation eines Transfer-Patches auf ein Wertdokumentsubstrat.

Show it:

• Figures 1 and 2 the production of a transfer material according to the invention according to a first exemplary embodiment;
• Figures 3 and 4 the application of a transfer patch to a valuable document substrate;
• Figures 5 to 8 the production of a transfer material according to the invention according to a second exemplary embodiment;
• Figures 9 and 10 the application of a transfer patch to a valuable document substrate.

Figures 1 and 2 illustrate the production of a transfer material according to the invention according to a first exemplary embodiment.

According to the Figure 1 A transfer film structure is initially provided. The transfer film structure is based on a carrier film 1, one or more functional layers 2 located thereon and a heat-sealing lacquer layer 3. The functional layers 2 provide optically variable security features, for example embossed holograms, micromirror elements, subwavelength structures and the like. The optically variable security features are generally provided by an embossing varnish, for example a UV embossing varnish, with microstructures embossed therein and a metallization present at least in some areas. The functional layers 2 have only weak adhesion to the carrier film 1, which can be achieved, for example, by poor adhesion of the embossing varnish to the carrier film 1 or by introducing a special separating layer.

According to the Figure 2 will be on the in the Figure 1 A shadow mask 4 is applied to the transfer film structure shown. The perforated mask 4 can in particular be provided by a perforated film from which the shapes of the desired patches are punched out. Such a perforated film 4 is advantageously laminated onto the transfer film structure. This can be done with an additional laminating adhesive (in the Figure 2 not shown) or simply by using the adhesive strength of the already existing heat sealing lacquer 3. The side facing the heat sealing lacquer 3 can advantageously be provided with a primer beforehand, which enables better bonding of the perforated film 4 and functional layers 2. Perforated film 4 and functional layers 2 can also only be glued in certain areas.

Figures 3 and 4 illustrate the application of a transfer patch according to the first exemplary embodiment to a value document substrate, in the present example a security paper for the production of banknotes.

During application, the patch is heated as usual, whereby the heat sealing lacquer 3 melts and sticks to the paper substrate 5 (see Figure 3 ). The heating can take place in areas (ie in an area that is slightly larger than the patch itself) or over the entire area.

Like in the Figure 4 is shown, the film structure 6 is then separated from the paper substrate 5. The functional layers 2 thus remain in the patch area on the paper substrate 5, since the heat sealing lacquer 3 to the paper 5 ensures a stronger adhesion than the adhesion between the carrier film 1 and functional layers 2. In the area Outside the patch, the functional layers 2 remain on the carrier film 1.

1. i) die Verhinderung des Verklebens von Funktionsschichten 2 und Papiersubstrat 5; und
2. ii) die Stabilisierung des Schichtverbunds zur Verhinderung des Aufreißens der Funktionsschicht 2 in Bereichen außerhalb des Patches.

The mask film 4 fulfills two tasks:

1. i) preventing functional layers 2 and paper substrate 5 from sticking together; and
2. ii) the stabilization of the layer composite to prevent the functional layer 2 from tearing in areas outside the patch.

Figures 5 to 8 illustrate the production of a transfer material according to the invention according to a second exemplary embodiment.

According to the Figure 5 A transfer film structure is initially provided. The transfer film structure is based on a carrier film 7, one or more functional layers 8 located thereon and a heat-sealing lacquer layer 9. The functional layers 8 provide optically variable security features, for example embossed holograms, micromirror elements, subwavelength structures and the like. The optically variable security features are generally provided by an embossing varnish, for example a UV embossing varnish, with microstructures embossed therein and a metallization present at least in some areas. The functional layers 8 have only weak adhesion to the Carrier film 7, which can be achieved, for example, by poor adhesion of the embossing varnish to the carrier film 7 or by introducing a special separating layer.

According to the Figure 6 will be the one in the Figure 5 shown transfer composite in the areas outside of the later patch with a laminating adhesive 10 (the laminating adhesive 10 is not absolutely necessary; alternatively, the already existing heat sealing lacquer 9 could be melted or activated in areas) and then glued with a film 11. Due to the positioning tolerances of bonding and punching-cutting, it is advantageous to end the bonding with sufficient distance from the patch.

According to the Figure 7 The patch shapes are then punched out (the solid lines 12 illustrate the punching tool) and the film 11 is removed in the areas of the holes, for example using compressed air or by pulling over a sharp edge.

A significant advantage of this variant is that the patches do not have to be torn out of the functional layer composite after application to the value document substrate (i.e. a break must occur within the functional layers), but rather the functional layers at the edge of the patch are already cleanly severed by punching (see the ones in the Figure 8 Punching lines 13 shown in dashed lines). This results in very clean patch edges.

Figures 9 and 10 illustrate the application of the transfer patch according to the second exemplary embodiment to a value document substrate, in the present example a security paper for the production of banknotes.

During application, the patch is heated as usual, whereby the heat sealing lacquer 9 melts and sticks to the paper substrate 14 (see Figure 9 ). The heating can take place in areas (ie in an area that is slightly larger than the patch itself) or over the entire area.

Like in the Figure 10 is shown, the film structure 15 is then separated from the paper substrate 14. The functional layers 8 thus remain in the patch area on the paper substrate 14, since the heat sealing lacquer 9 to the paper 14 ensures a stronger adhesion than the adhesion between the carrier film 7 and functional layers 8. In the area Outside the patch, the functional layers 8 remain on the carrier film 7.

Claims (8)

1. A security element transfer material, comprising

   a security element layer composite which has a multiplicity of layers, including at least one feature layer (2, 8) developing an optically variable effect and an adhesive layer (3, 9), wherein the feature layer is the layer which faces a viewer after a security element has been transferred to a value document substrate; and

   a carrier substrate (1, 7) which is detachably connected to the feature layer (2, 8) of the security element layer composite;

   a mask layer (4, 11) having at least one cutout, which is configured such that the security element layer composite in the region of the at least one cutout of the mask layer (4, 11) can be adhesively bonded to the value document substrate (5, 14) by the action of pressure and possibly heat by means of the adhesive layer (3, 9) and then detached from the carrier substrate (1, 7), wherein, in the region outside the at least one cutout of the mask layer (4, 11), the security element layer composite is prevented from adhering to the value document substrate (5, 14) and from a subsequent detachment of the security element layer composite from the carrier substrate (1, 7),

   characterized in that the mask layer (4, 11) is formed by a foil.
2. The security element transfer material according to claim 1, wherein the feature layer (2, 8) developing an optically variable effect is based on a reflective embossed structure.
3. The security element transfer material according to claim 2, wherein the reflective embossed structure is configured as follows: (a) a reflective diffractive structure or (b) a reflective microstructure in the form of a mosaic of a multiplicity of reflective mosaic elements which are determined by the parameters size, contour shape, relief shape, reflectivity and spatial alignment and which form a predetermined motif in that different groups of mosaic elements with different characteristic parameters reflect incident light into different spatial regions, and in which the mosaic elements have a lateral dimension below the resolution limit of the eye.
4. The security element transfer material according to claim 2 or 3, wherein the reflective embossed structure (i) as reflective layers has opaque metal layers, or (ii) as reflective layers has transparent, highly refractive layers, or (iii) as reflective layers has thin-film elements with a color shift effect, in particular with a reflective layer and a semitransparent layer and an interposed dielectric layer, or (iv) as reflective layers has layers of liquid crystalline material, in particular of cholesteric liquid crystalline material, or (v) as reflective layers has printed layers based on effect pigment compositions with viewing angle-dependent effect or with different colors when viewed in incident light and when viewed in transmitted light or (vi) as reflective layers has the following multilayer structure: two semitransparent layers and one dielectric layer arranged between the two semitransparent layers, wherein the multilayer structure has different color tones when viewed in incident light on the one hand and when viewed in transmitted light on the other hand.
5. A method for manufacturing a security element transfer material according to any of claims 1 to 4, comprising

   a) making available a carrier substrate (1, 7);

   b) supplying the carrier substrate (1, 7) with a security element layer composite which has a multiplicity of layers, including at least one feature layer (2, 8) developing an optically variable effect and an adhesive layer (3, 9), wherein the feature layer (2, 8) is the layer which faces a viewer after a security element has been transferred to a value document substrate, wherein the carrier substrate (1, 7) is detachably connected to the feature layer (2, 8) of the security element layer composite;

   c) separately making available a mask layer (4, 11) having at least one cutout;

   d) adhesively bonding the mask layer to the security element layer composite obtained in step b), so that a security element transfer material is obtained in which the security element layer composite in the region of the at least one cutout of the mask layer (4, 11) can be adhesively bonded to a value document substrate by the action of pressure and possibly heat by means of the adhesive layer (3, 9) and then detached from the carrier substrate (1, 7), wherein, in the region outside the at least one cutout of the mask layer (4, 11), the security element layer composite is prevented from adhering to the value document substrate and from a subsequent detachment of the security element layer composite from the carrier substrate (1, 7).
6. A method for manufacturing a security element transfer material according to any of claims 1 to 4, comprising

   a) making available a carrier substrate (1, 7);

   b) supplying the carrier substrate (1, 7) with a security element layer composite which has a multiplicity of layers, including at least one feature layer (2, 8) developing an optically variable effect and an adhesive layer (3, 9), wherein the feature layer (2, 8) is the layer which faces a viewer after a security element has been transferred to a value document substrate, wherein the carrier substrate is detachably connected to the feature layer (2, 8) of the security element layer composite;

   c) applying a foil suitable for producing a mask layer (4, 11) having at least one cutout onto the security element layer composite obtained in step b), wherein the foil is adhesively bonded to the security element layer composite merely in the region outside the at least one cutout to be produced and in the region of the at least one cutout to be produced is not adhesively bonded to the security element layer composite;

   d) producing at least one cutout in the foil obtained in step c) in order to produce a mask layer (4, 11) in this manner, so that a security element transfer material is obtained in which the security element layer composite in the region of the at least one cutout of the mask layer (4, 11) can be adhesively bonded to a value document substrate by the action of pressure and possibly heat by means of the adhesive layer (3, 9) and then detached from the carrier substrate (1, 7), wherein, in the region outside the at least one cutout of the mask layer (4, 11), the security element layer composite is prevented from adhering to the value document substrate (5, 14) and from a subsequent detachment of the security element layer composite from the carrier substrate (1, 7).
7. The method according to claim 6, wherein in step d) the production of at least one cutout in the foil obtained in step c) is effected by means of punching and the punched-out foil material is removed.
8. The method according to claim 7, wherein in the step of punching out not only the foil to be converted into a mask layer (4, 11) is supplied with punch lines, but also the security element composite layer to be transferred is provided with punch lines.

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