EP3768521B1 - Method for producing a security element transfer material - Google Patents

Description

1. a) das Bereitstellen eines Trägersubstrats, das in der Reihenfolge mit einem Sicherheitselement-Schichtverbund und einer eine Aussparung aufweisenden Maskenfolie versehen ist, wobei der Sicherheitselement-Schichtverbund eine mit dem Trägersubstrat abtrennbar verbundene, einen optisch variablen Effekt entfaltende Merkmalsschicht, die nach einer Übertragung eines Sicherheitselements auf ein Wertdokumentsubstrat einem Betrachter zugewandt ist, und eine Klebstoffschicht aufweist, wobei entlang der Aussparung der Maskenfolie ein auf ein Wertdokumentsubstrat zu transferierender, mit Stanzlinien versehener Sicherheitselement-Schichtverbund gebildet ist,
2. b) das Ablösen der Maskenfolie zusammen mit dem von der Maskenfolie maskierten, außerhalb der Aussparung der Maskenfolie vorhandenen Sicherheitselement-Schichtverbund vom Trägersubstrat.

The invention relates to a method for producing a security element transfer material comprising a security element provided on a carrier substrate and designed as a transfer element

1. a) the provision of a carrier substrate which is provided in the sequence with a security element layer composite and a mask film having a recess, the security element layer composite having a feature layer separable to the carrier substrate, developing an optically variable effect, which after a transfer of a security element facing a viewer on a value document substrate, and having an adhesive layer, a security element layer composite provided with punched lines being formed along the recess of the mask film, which is to be transferred to a value document substrate,
2. b) the detachment of the mask film together with the security element layer composite masked by the mask film and present outside the recess of the mask film from the carrier substrate.

Valuables, such as branded items or documents of value, in particular banknotes, are often equipped with security elements which allow the authenticity of the valuable object to be checked and which 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. It is characteristic of transfer tapes that the security elements are prepared on a carrier layer, with the order of the layers of the transfer elements having to be reversed as they are later on protective object should be present. During the transfer, the carrier layer is typically peeled off 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 lacquer, which melts when the security elements are transferred and bonds the security elements to the object to be secured. The transfer tape with the heat-sealing adhesive layer is placed on the object and pressed on by means of a heated transfer stamp or a transfer roller and transferred to the object in the shape of the heated transfer stamp. Transfer elements, transfer belts and the transfer of transfer elements to 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 lacquers, transfer elements, e.g. transfer patches, do not tear off cleanly at the border of the heated area. This leads to unclean edges and possibly also to the fact that remnants of the film composite that were torn from the layer composite in the non-bonded area stick to the transferred patches. These residues are undesirable because they later loosen and, in the form of impurities, impair subsequent processing steps, e.g. printing processes.

Instead of the shaping of the transfer elements by the transfer die during the transfer process, the individual transfer elements can also already be present on the transfer belt in the desired outline shape. The prefabrication of separate individual security elements is useful, for example, when the security elements have a layer structure that allows an exact severing of the entire layer structure during the Makes the transfer process difficult. This is the case, for example, when 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 exposed to high stresses during their period of circulation, are tapped, kinked and, under certain circumstances, exposed to moisture. The security elements must be able to withstand these stresses in the same way as the banknote paper itself, since otherwise there would be the risk that the through opening in the banknote would be exposed after a certain period of circulation.

Security elements, the layer structure of which comprises a stable carrier substrate, typically a plastic film, must be present on a transfer material as prefabricated individual elements, which means that the outline of the security elements must be precut in the security element material. The pre-cutting can be carried out, for example, by means of a laser. The problem arises that the depth of cut has to 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 damage the carrier material that is separated during the transfer. Plastic films are usually used as carrier materials. Plastic films have a high tear resistance, but a low one Tear propagation resistance. If they are cut, it can hardly be avoided that the security element transfer material present as a continuous material tears in some places in the course of the process of transferring the security elements to objects of value. It must also be taken into account that the layer structures to be cut or the carrier foils that are not to be cut are materials with thicknesses in the micrometer range. The security element layer structures typically have thicknesses in the range from about 20 μm to 30 μm, and the carrier films typically have thicknesses in the range from 10 μm to 20 μm. With 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 good time so that the carrier film is not cut anywhere. Due to the partially cut carrier film, however, the security element transfer material loses its stability and may even tear, which is why an exact and smooth application of the security elements from the continuous material to the products to be protected is no longer guaranteed.

From the WO 2010/031543 A1 known. The security element transfer material is an endless material, in particular a tape with a length of several hundred meters and a width of a few millimeters / centimeters up 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 "stored" on. The temporary carrier is based on a carrier layer composite, consisting of a first and a second temporary carrier substrate, which are permanently bonded by means of 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 to an object of value. The temporary carrier is located on the side of the security element layer composite which, after the transfer of the security elements, faces a viewer. The term “temporary” carrier substrates expresses that, in contrast to the “permanent” carrier substrate, these carrier substrates are not part of the security elements. The formation 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 the contour shapes of the security elements are cut. A comparable result cannot simply be achieved by making a single temporary carrier film correspondingly thicker, since plastic films have a low tear resistance, i.e. if a film is only slightly cut, it tears further and possibly completely. This is not the case with the carrier layer composite, consisting of a first and a second temporary carrier substrate, which are permanently bonded by means of an adhesive layer: even if one of the temporary carrier substrates is completely severed, the further temporary carrier substrate (or possibly the further temporary carrier substrates) generally remains undamaged and accordingly stable. The adhesive also forms an additional "buffer zone" between the temporary carrier substrates.

The one in the WO 2010/031543 A1 The method described consists of weeding the patch film before application. For this purpose, the shapes of the patch are punched into the layers to be transferred with a punch, ie the layers are broken through with the punch. When weeding, these layers are then peeled off 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. A disadvantage of this method, however, 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.

DE 10 2015 121849 A1 discloses a method for producing a security element transfer material with a security element provided on a carrier substrate and configured as a transfer element, comprising the provision of a carrier substrate which is provided in the sequence with a security element layer composite, the security element layer composite being detachably connected to the carrier substrate , a feature layer developing an optically variable effect which, after a security element has been transferred to a value document substrate, faces a viewer, and has an adhesive layer, a security element layer composite provided with punched lines being formed to be transferred to a value document substrate, the detachment of the existing security element Layer composite from the carrier substrate.

DE 10 2015 121849 A1 does not disclose that a mask film having a recess is used, the punching lines being along the recess of the mask film, and the mask film being detached from the carrier substrate together with the security element layer composite masked by the mask film and present outside the recess of the mask film.

The invention is based on the object of providing a method for producing a transfer element, for example a transfer patch, which is improved over the prior art. In particular, 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 should be achieved.

This object is achieved by the combination of features defined in the main claim and in the subordinate independent claim. Further developments are the subject of the subclaims.

Summary of the invention

The method according to the invention is described in claim 1.

• Bereitstellen eines Trägersubstrats;
• Versehen des Trägersubstrats mit einem Sicherheitselement-Schichtverbund und einer zumindest eine Aussparung aufweisenden Maskenfolie, wobei der Sicherheitselement-Schichtverbund eine mit dem Trägersubstrat abtrennbar verbundene, einen optisch variablen Effekt entfaltende Merkmalsschicht, die nach einer Übertragung eines Sicherheitselements auf ein Wertdokumentsubstrat einem Betrachter zugewandt ist, aufweist, wobei entlang der Aussparung der Maskenfolie ein auf ein Wertdokumentsubstrat zu transferierender, mit Stanzlinien versehener Sicherheitselement-Schichtverbund gebildet ist;

• das Aufbringen einer Klebstoffschicht, insbesondere drucktechnisch, auf den Sicherheitselement-Schichtverbund zumindest im Bereich der Aussparung der Maskenfolie, wobei gegebenenfalls der an die Aussparung angrenzende Teil der Maskenfolie ebenfalls mit Klebstoff versehen werden darf;
• das Ablösen der Maskenfolie zusammen mit dem von der Maskenfolie maskierten, außerhalb der Aussparung der Maskenfolie vorhandenen Sicherheitselement-Schichtverbund vom Trägersubstrat.

The adhesive layer of the security element layer composite does not necessarily have to be present over the entire area along the entire security element layer composite, but according to one variant can only be present in the area of the security element to be produced and designed as a transfer element. In this case, the production can take place as follows, for example:

• Providing a carrier substrate;
• Providing the carrier substrate with a security element layer composite and a mask film having at least one recess, the security element layer composite having an optically variable effect that is detachably connected to the carrier substrate unfolding feature layer which, after a security element has been transferred to a value document substrate, faces a viewer, a security element layer composite provided with punched lines being formed along the recess of the masking film to be transferred to a value document substrate;

• the application of an adhesive layer, in particular by means of printing, to the security element layer composite at least in the area of the recess of the mask film, with the part of the mask film adjoining the recess possibly also being allowed to be provided with adhesive;
• the detachment of the masking film together with the security element layer composite, masked by the masking film and present outside the recess of the masking film, from the carrier substrate.

Detailed description of the invention

In the context of this invention, viewing in incident light is illuminating the document of value from one side and viewing the document of value from the same side. Viewing in incident light lies thus, for example, when the front of the document of value is illuminated and also viewed.

In the context of this invention, viewing in transmitted light is 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 is thus present, 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 value document.

A value document within the meaning of the invention can be, for example, bank notes or identity documents, but also shares, certificates, postage stamps, checks, admission tickets, tickets, flight tickets, ID cards, visa stickers or the like, as well as labels, seals, packaging or other elements. The simplifying term “document of value” therefore always includes documents of the type mentioned in the following. The term value document also includes security paper for the production of bank notes. The term bank note includes in particular a paper bank note, a polymer bank note or a film composite bank note.

The transfer element, ie 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 restricted to a patch.

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

Instead of the phrase “a mask film having at least one recess”, the term perforated mask or perforated film is also used here.

• Eine geringere Schichtdicke vor der Applikation bzw. Endanwendung des Transferpatch. Damit ist auch eine größere Lauflänge des auf Spulen aufgewickelten Sicherheitselement-Transfermaterials möglich.
• Eine geringere Schichtdicke nach der Applikation bzw. Endanwendung des Transferpatch. Die geringe Schichtdicke eines mit dem Patch versehenen Wertdokumentsubstrats, insbesondere ein Sicherheitspapier oder eine Banknote, ist für die Verarbeitung im Banknotendruck von Vorteil, z.B. bezüglich der verbesserten Planlage der mit dem Patch versehenen Bögen und bezüglich der geringeren Stapelhöhe der mit dem Patch versehenen Banknoten.
• Ein höherer Manipulationsschutz, weil ein zerstörungsfreies Ablösen eines Patch von einer mit dem Patch versehenen Banknote erschwert wird.

In the method according to the invention for producing a security element transfer material, a perforated mask is used in the step of weeding. The perforated mask is removed from the security element transfer material before the application, ie the end use, of the transfer patch to be produced. In this respect, the method according to the invention is similar to that from the prior art WO 2010/031543 A1 known method in which transfer patches are punched out and the intermediate areas are removed when weeding. In contrast to the one from the WO 2010/031543 A1 known processes, however, the transfer patches according to the invention themselves no longer have a stabilizing film. This results in comparison with the WO 2010/031543 A1 known transfer patch materials have the following advantages:

• A smaller layer thickness before the application or final use of the transfer patch. A greater length of the security element transfer material wound on spools is thus also possible.
• A lower layer thickness after the application or final use of the transfer patch. The small layer thickness of a value document substrate provided with the patch, in particular a security paper or a bank note, is advantageous for processing in bank note printing, for example with regard to the improved flatness of the sheets provided with the patch and with regard to the lower stack height of the bank notes provided with the patch.
• A higher protection against manipulation, because a non-destructive detachment of a patch from a bank note provided with the patch is made more difficult.

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

1. Provision of a transfer film structure:

The starting point is a normal transfer film structure, such as is also used for the application of 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, e.g. embossed holograms, micromirror elements, sub-wavelength structures and the like. The optically variable security features are usually given by an embossed lacquer, e.g. a UV embossed lacquer, with microstructures embossed therein and a metallization present at least in some areas. Often there are additional layers, e.g. protective varnishes or primers, which are then followed by the heat-sealing varnish at the end. The heat-sealing 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 lacquer to the carrier film or by introducing a special separating layer.

2. Applying a shadow mask:

According to the invention, a perforated mask is applied to the above-mentioned transfer film structure. 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 strength of the heat seal lacquer that is already present. The side facing the heat-sealing lacquer can advantageously be provided with a primer beforehand, which enables the perforated film and functional layers to be bonded better. Perforated film and functional layers can also only be glued in areas. Theoretically, the perforated film can only stick to the functional layers when the heat-sealing lacquer is melted on during application. In practice, however, it is advantageous to prevent the perforated film from slipping by gluing at least in certain areas.

3. Punching:

In the punching step, punching lines are introduced by means of a punching tool or a cutting tool in order to punch the patch shapes to be produced in this way, i.e. punch the outlines of the patches into the transfer composite. The punched shape is advantageously somewhat smaller than the holes in the shadow mask.

4. Remove the shadow mask

The perforated mask or perforated film is then peeled off from the carrier film together with the heat-sealing lacquer layer covered by the perforated film and the functional layers in the weeding step. The patches thus remain on the carrier film and a weed transfer patch film is obtained.

During application or end use, the patch is heated as usual, the heat-sealing lacquer melting on and glued to the (value document) substrate. The (value document) substrate can be, for example, a paper or polymer substrate or a paper / polymer composite substrate. The heating can be done in areas (ie in an area that slightly larger than the patch itself) or over the entire surface. If the carrier film is then separated 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 stronger adhesion than the adhesion between carrier film and functional layers.

According to a further, preferred embodiment, a transfer material can be implemented as follows:

1. Provision of a transfer film structure:

The starting point is again a normal transfer film structure, such as that used, for example, for the application of 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, e.g. embossed holograms, micromirror elements, sub-wavelength structures and the like. The optically variable security features are usually given by an embossed lacquer, e.g. a UV embossed lacquer, with microstructures embossed therein and a metallization present at least in some areas. Often there are additional layers, e.g. protective varnishes or primers, which are then followed by the heat-sealing varnish at the end. The heat-sealing lacquer layer can actually also 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 lacquer to the carrier film or by introducing a special separating layer.

2. Application of a non-perforated film:

An initially unperforated film is applied to the above-mentioned transfer film structure, in particular by means of an adhesive layer ("laminating adhesive") that is present in some areas.

3. Punching:

In the punching step, punching lines are introduced by means of a punching tool or a cutting tool in order to punch the patch shapes to be produced in this way, i.e. punch the outlines of the patches into the transfer composite. At the same time, holes are created in the initially unperforated film and the stabilizing film is removed in the perforated areas, e.g. by suction or blowing.

4. Remove the shadow mask

The perforated mask or perforated film is then peeled off from the carrier film together with the heat-sealing lacquer layer covered by the perforated film and the functional layers in the weeding step. The patches thus remain on the carrier film and a weed transfer patch film is obtained.

Due to the positioning tolerances of the gluing and die cut, it is advantageous to end the gluing in step 2 above with a sufficient distance from the patch. The patch shapes are then punched out and the film removed in the areas of the holes, e.g. by means of compressed air or by pulling over a sharp edge.

Another advantage of the method according to the invention is that the patches do not have to be torn out of a functional layer composite in the step of application to the (value document) substrate (i.e. a break has to occur within the functional layers), but rather the functional layers already through at the edge of the patch the punching are cleanly cut. This results in very clean patch edges.

Further preferred design variants:

Functional layers:

For example, micromirrors, hologram structures, subwavelength structures or (for example embedded) microlenses can be incorporated in the functional layers. Microlenses can in particular be present in combination with microimages formed in a separate plane and in this way generate 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, 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. A1 or Ag, a high-index coating, e.g. ZnS or TiO ₂ , or a color-changing three-layer reflector / dielectric / absorber system (e.g. a Al / SiO _{2 /} Cr structure).

Heat sealing lacquer:

It is essential for the heat-sealing gel lacquer that at the end of the application it ensures the desired adhesion through pressure and possibly increased temperature. The heat can melt it and / or activate it. It is also possible to post-treat the heat-sealing lacquer afterwards, e.g. by means of UV radiation (post-crosslinking).

Foil thickness:

The perforated film is preferably as thin as possible. Films with thicknesses in a range from 4.5 µm to 19 µm can be used with advantage. A polyethylene terephthalate (PET) film is preferably used as the film.

Carrier substrate or carrier film:

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 into by means of punching, something is generally also punched into the carrier film. It must be ensured here that the carrier film does not tear after the patch has been applied to the (value document) substrate. According to an advantageous variant, not a single carrier film is used here as the carrier film, but a laminating composite consisting of two films, as is the case with the 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 out during punching, while the second film remains undamaged. A single punched film tears more easily than a laminated composite, since the "tear" of a film requires more force than tearing it further.

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

For a better transfer, it can be advantageous to pull the carrier film off the rest of the layer composite over a sharp edge (or a wedge).

Other preferred parameters:

• The functional layers preferably contain embossing lacquers, which typically have a total thickness in a range from 2 μm to 7 μm. Depending on the structure type, typical embossing depths can be in a range from 100 nm to 3.5 µm, for example.
• 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 e.g. widths of 5 mm to 35 mm and heights of e.g. 5 mm to 70 mm.
• The patch shape can be chosen arbitrarily. Oval shapes are usually easier to apply than e.g. rectangular shapes. A jagged edge may be beneficial. In particular, the variant of punching the functional layers (see above) also enables the application of patches with complex outlines that are difficult to apply under normal conditions.

Further general remarks:

The embossed structure that can be used according to the invention is in particular embossed into an embossed lacquer. In the context of the present application, the expression “optically variable effect” includes not only holograms but also hologram-like diffraction structures, that is to say, for example, structures that do not produce a defined image but rather a blurred colored impression. The term "optically variable effect" also subsumes diffraction patterns, structures with color-shifting effects, cinema forms, structures with a microlens effect, structures with isotropic or anisotropic scattering effects or with other interference effects, sub-wavelength structures, moth-eye structures, microlens structures and microstructures for moire mapper or modulus mapper , Micromirror structures and microprismatic structures.

• einer reflektierenden Schicht (insbesondere einer metallischen, reflektierenden Schicht);
• einer semitransparenten (Spiegel-)Schicht (die insbesondere von der Gruppe bestehend aus AI, 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, a multilayer structure capable of interference

• a reflective layer (in particular a metallic, reflective layer);
• a semitransparent (mirror) layer (which is selected in particular 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,

wherein the color of the multilayer construction changes with the change of the viewing angle.

It is possible to produce a first appearance of the multilayer structure capable of interference when viewing the front side in reflected light and a second appearance of the multilayer structure capable of interference when viewing the front side in transmitted light, e.g. through cutouts in the reflective layer and / or the semitransparent layer Layer. Such a film security element with different reflected-light / transmitted-light appearances is from WO 2009/149831 A2 known. For example, the semitransparent layer can have a multiplicity of cutouts arranged in the manner of a grid, which in their entirety result in a character, an image or a pattern. The pattern created in this way is visible in incident light and disappears in transmitted light. Alternatively and / or additionally, a different reflected-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.

• die beiden semitransparenten Spiegelschichten werden bevorzugt von A1 oder Ag gewählt; die dielektrische Schicht ist insbesondere eine SiO_2-Schicht;
• im Falle, dass jede der beiden semitransparenten Spiegelschichten auf A1 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 SiO_2-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 SiO_2-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 contain, for example, a multilayer structure with two semitransparent layers and one arranged between the two semitransparent layers dielectric layer, the multilayer structure having different color tones when viewed in incident light on the one hand and when viewed in transmitted light on the other hand, appears gold-colored when viewed in incident light and shows a blue hue when viewed in transmitted light. The two different shades are in particular complementary colors. Such a multilayer structure is based in particular on two semitransparent mirror layers and a dielectric layer arranged between the two semitransparent mirror layers. Such a multilayer structure, which appears gold-colored when viewed in reflected light and shows a blue hue when viewed in transmitted light, is, for example, from FIG WO 2011/082761 A1 known. 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 A1 or Ag being preferred as the semitransparent mirror layer and A1 is 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 semitransparent mirror layers are preferably selected from A1 or Ag; the dielectric layer is in particular an SiO ₂ layer;
• in the event that each of the two semitransparent mirror layers is based on A1, 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, more preferably in a range from 80 nm to 260 nm, the ranges from 80 nm to 100 nm and from 220 nm up to 240nm are especially preferred for providing a gold / blue color change;
• in the event that each of the two semitransparent 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 from 50 nm to 450 nm, more preferably in a range from 80 nm to 260 nm, the ranges from 80 nm to 100 nm and from 220 nm to 240 nm especially for providing a gold / Blue color change are particularly preferred.

• 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 above-mentioned multi-layer structures not only enable the creation of a semitransparent functional layer, which appears gold when viewed in reflected light and shows a blue hue when viewed in transmitted light, but further color changes can be generated depending on the choice of layer thickness, especially of the dielectric layer, e.g.

• Magenta in incident light, blue-green in transmitted light;
• turquoise in incident light, orange-yellow in transmitted light;
• gold in incident light, blue-violet in transmitted light;
• Silver in incident light, violet in transmitted light.

Further preferred reflective embossed structures contain, for example, a liquid crystal layer which shows a different color when viewed in incident light 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 printed 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 purple / green color change or a silver / opaque color change. Such printing inks are, 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 printing 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, 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 prior art (see e.g. WO 2014/060089 A2 ). The dimensions of the structural elements of the micromirror arrangement are preferably in a range that is greater than 1 μm and less than 40 μm, 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. Included 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 in reflect different spatial areas, and in which the mosaic elements have a lateral dimension below the resolution limit of the eye.

Further exemplary embodiments as well as 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 proportion was dispensed with in order to increase the clarity.

Figuren 1 bis 4

die Herstellung eines erfindungsgemäßen Transfermaterials gemäß einem ersten Ausführungsbeispiel; und

Figuren 5 bis 9

die Herstellung eines erfindungsgemäßen Transfermaterials gemäß einem zweiten Ausführungsbeispiel.

Show it:

Figures 1 to 4

the production of a transfer material according to the invention according to a first embodiment; and

Figures 5 to 9

the production of a transfer material according to the invention according to a second embodiment.

Figures 1 to 4 illustrate the production of a transfer material according to the invention according to a first embodiment.

According to the Figure 1 a transfer film structure is first 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 embossed lacquer, for example a UV embossed lacquer, with microstructures embossed therein and a metallization that is 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 lacquer to the carrier film 1 or by introducing a special separating layer.

According to the Figure 2 is on the in the Figure 1 A perforated 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 heat seal lacquer 3 which is already present. Perforated film 4 and functional layers 2 can also only be glued in areas. According to the Figure 3 the patch shapes are then punched (the broken lines 5 illustrate the punched lines). Because of the positioning tolerances, it is advantageous that the punching lines 5 are somewhat spaced from the edges of the perforated film 4.

Like in the Figure 4 is shown, the perforated film 4 is then separated from the carrier film 1 together with the heat-sealing lacquer layer 3 and the functional layers 2 present in the region of the perforated film 4 (ie outside the hole) in the weeding step. The heat seal lacquer layer 3 and the functional layers 2 therefore remain in the patch area on the carrier film 1, since the heat seal lacquer 3 to the perforated mask 4 ensures stronger adhesion than the adhesion between carrier film 1 and functional layers 2.

The Indian Figure 4 The transfer patch obtained can then be applied or applied to a value document substrate, for example a security paper for the production of bank notes. In the case of such an application, the patch is heated as usual, the heat-sealing lacquer 3 melting on and glued to the paper substrate. The heating can take place in areas (ie in an area that is slightly larger than the patch itself) or over the entire area. The carrier film 1 is then detached from the remaining layers of the patch applied to the paper substrate. The functional layers 2 therefore remain in the patch area on the paper substrate, since the heat-sealing lacquer 3 ensures stronger adhesion to the paper than the adhesion between the carrier film 1 and the functional layers 2.

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

According to the Figure 5 a transfer film structure is first provided. The transfer film structure is based on a carrier film 7, one or more functional layers 8 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 embossed lacquer, for example a UV embossed lacquer, with microstructures embossed therein and a metallization that is 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 lacquer to the carrier film 7 or by introducing a special separating layer.

According to the Figure 6 is the one in the Figure 5 The transfer composite shown is provided with a laminating adhesive 10 in the areas outside of the later patch (the laminating adhesive 10 is, however, not absolutely necessary; alternatively, the 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 the gluing and die cut, it is advantageous to let the gluing end at a sufficient distance from the patch.

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

the Figure 8 illustrates the layer structure obtained, provided with cut lines 13 (shown in the figure in the form of broken lines). Like in the Figure 9 is shown, the perforated film 11 is then separated from the carrier film 7 together with the laminating adhesive layer 10 present in the region of the perforated film 11, the heat-sealing lacquer layer 9 and the functional layers 8 in the weeding step. The heat seal lacquer layer 9 and the functional layers 8 therefore remain in the patch area on the carrier film 7, since the heat seal lacquer 9 to the perforated mask 11 ensures stronger adhesion than the adhesion between carrier film 7 and functional layers 8.

The Indian Figure 9 The transfer patch obtained can then be applied or applied to a value document substrate, for example a security paper for the production of bank notes. In the case of such an application, the patch is heated as usual, the heat-sealing lacquer 9 melting on and glued to the paper substrate. The heating can take place in areas (ie in an area that is slightly larger than the patch itself) or over the entire area. The carrier film 7 is then detached from the remaining layers of the patch applied to the paper substrate. The functional layers 8 thus remain in the patch area on the paper substrate, since the heat-sealing lacquer 9 ensures stronger adhesion to the paper than the adhesion between the carrier film 7 and the functional layers 8.

• Bereitstellen eines Trägersubstrats;
• Versehen des Trägersubstrats mit einem Sicherheitselement-Schichtverbund und einer zumindest eine Aussparung aufweisenden Maskenfolie, wobei der Sicherheitselement-Schichtverbund eine mit dem Trägersubstrat abtrennbar verbundene, einen optisch variablen Effekt entfaltende Merkmalsschicht, die nach einer Übertragung eines Sicherheitselements auf ein Wertdokumentsubstrat einem Betrachter zugewandt ist, aufweist, wobei entlang der Aussparung der Maskenfolie ein auf ein Wertdokumentsubstrat zu transferierender, mit Stanzlinien versehener Sicherheitselement-Schichtverbund gebildet ist;
• das Aufbringen einer Klebstoffschicht, insbesondere drucktechnisch, auf den Sicherheitselement-Schichtverbund zumindest im Bereich der Aussparung der Maskenfolie, wobei gegebenenfalls der an die Aussparung angrenzende Teil der Maskenfolie ebenfalls mit Klebstoff versehen werden darf;
• das Ablösen der Maskenfolie zusammen mit dem von der Maskenfolie maskierten, außerhalb der Aussparung der Maskenfolie vorhandenen Sicherheitselement-Schichtverbund vom Trägersubstrat.

In a variant of the above-mentioned exemplary embodiments, the procedure is as follows:
The adhesive layer of the security element layer composite does not necessarily have to be present over the entire area along the entire security element layer composite, but rather, according to the variant, can only be in the area of the transfer element to be produced Security elements are present. In this case, the production can take place as follows, for example:

• Providing a carrier substrate;
• Providing the carrier substrate with a security element layer composite and a mask film having at least one cutout, wherein the security element layer composite has an optically variable effect, detachably connected to the carrier substrate and facing a viewer after a security element has been transferred to a value document substrate wherein a security element layer composite provided with punched lines is formed along the recess of the masking film and is to be transferred to a value document substrate;
• the application of an adhesive layer, in particular by means of printing, to the security element layer composite at least in the area of the recess of the mask film, with the part of the mask film adjoining the recess possibly also being allowed to be provided with adhesive;
• the detachment of the masking film together with the security element layer composite, masked by the masking film and present outside the recess of the masking film, from the carrier substrate.

Claims (7)

1. A method for manufacturing a security element transfer material having a security element provided on a carrier substrate and designed as a transfer element, comprising

   a) the supplying of a carrier substrate (1, 7) which is provided in sequence with a security element layer composite (2, 8) and a masking film (4, 11) having at least one recess, wherein the security element layer composite has a feature layer (2, 8), which is detachably connected to the carrier substrate, develops an optically variable effect and faces a viewer after a transfer of a security element to a document substrate of value, and an adhesive layer (3, 9, 10), wherein a security element layer composite provided with punched lines (5,13) and to be transferred onto a value document substrate is formed along the recess of the masking film,

   b) the detaching of the masking film, together with the security element layer composite present outside the recess of the masking film and masked by the masking film, from the carrier substrate.
2. The method according to claim 1, wherein the step a) of supplying a carrier substrate, which is provided in sequence with a security element layer composite and a masking film having at least one recess, is carried out such that first a masking film (4) provided with at least one recess is applied to the security element layer composite, followed by an introducing of punched lines (5) into the security element layer composite along the recess.
3. The method according to claim 1, wherein the step a) of supplying a carrier substrate, which is provided in sequence with a security element layer composite and a masking film having at least one recess, is carried out such that first punched lines are introduced into the security element layer composite, followed by an applying in exact register of a masking film provided with at least one recess to the security element layer composite provided with punched lines.
4. The method according to claim 1, wherein the step a) of supplying a carrier substrate, which is provided in sequence with a security element layer composite and a masking film (11) having at least one recess, is carried out such that first a full-area masking film (11) is applied to the security element layer composite by means of a further adhesive layer (10), wherein the further adhesive layer is intended only in the region outside the recess to be produced in the masking film, followed by a producing of a recess in the full-area masking film along the further adhesive layer by means of punching out (12) and a removing of the punched-out masking film material, wherein in the step of punching out, the introducing of punched lines (13) into the security element layer composite takes place at the same time.
5. The method according to any of claims 1 to 4, wherein the feature layer, developing an optically variable effect, is based on a reflective embossed structure.
6. The method according to claim 5, wherein the reflective embossed structure is constituted as follows: (a) a reflective diffractive structure or (b) a reflective microstructure in the form of a mosaic of a plurality of reflective mosaic elements which are characterized by the parameters size, outline form, relief form, reflectivity and spatial orientation, and which form a predetermined motif, by different groups of mosaic elements, having different characteristic parameters, reflecting incident light in different spatial areas, and wherein the mosaic elements have a lateral dimension below the resolution limit of the eye.
7. The method according to claim 5 or 6, wherein the reflective embossed structure (i) has, as reflective layers, opaque metal layers or (ii) has, as reflective layers, transparent, high-refractive layers, or (iii) has, as reflective layers, thin-film elements having a color-shift effect, in particular having a reflective layer and a semi-transparent layer and a dielectric layer arranged between them, or (iv) has, as reflective layers, layers of liquid-crystalline material, in particular of cholesteric liquid-crystalline material, or (v) has, as reflective layers, printed layers based on effect-pigment compositions having a viewing angle-dependent effect or having different colors upon incident-light observation and transmitted-light observation, or (vi) has, as reflective layers, the following multilayer structure: two semi-transparent layers and a dielectric layer arranged between the two semi-transparent layers, wherein the multilayer construction has different color tones upon viewing in incident light on the one hand and upon viewing in transmitted light on the other hand.

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