EP3183124B1 - Transfer foil and method for producing a transfer foil - Google Patents

Description

The invention relates to a transfer film, in particular hot stamping film, the use of a transfer film, a film, a security document, and a method for producing a transfer film.

Security documents such as banknotes, passports, ID cards, check cards, credit cards, visas or certificates are often provided with security elements to increase counterfeit protection. Such security elements are used to check the security documents for authenticity and to recognize counterfeit or manipulation. Furthermore, security elements on security documents increase the protection against unlawful duplication. Furthermore, such security elements in the field of commercial products or product packaging, where the authenticity is to be verified used.

Security elements often have diffractive light diffractive structures such as holograms, which after application to a Security document whose counterfeit security should increase. These security elements offer the viewer memorable optically variable effects. Often, in addition to the already mentioned security elements, which are based on diffractive optical effects, also optically variable thin film layer elements are used, which provide a viewer under different viewing angles, for example, a different color impression. Such thin film layer elements are based on interference effects.

Security elements with, for example, diffractive structures are often transferred by means of transfer methods to the security documents to be secured. For this purpose, a transfer layer is transferred, for example under the action of heat and pressure, from a carrier film to a target substrate to which the transfer layer adheres using an adhesive layer.

On the other hand, other security features that also increase the protection against counterfeiting of security documents, such as optically variable effect colors or soluble dyes, are printed directly on the target substrate. For this purpose, the screen printing method is usually used, in which in particular the achievable brilliance and the expressiveness of the color effects depend on the nature of the target substrate. The target substrate may be in the form of sheets or as a roll.

The WO 2011/012520 A2 describes a transfer film comprising a carrier layer and a transfer layer arranged on the carrier layer in the form of a design with aligned optically variable magnetic pigments.

The WO 2012/000631 A2 relates to a method and a transfer tape for decorating surfaces, in particular for decorating outer packaging.

The invention is now based on the object to provide a transfer film, which avoids the disadvantages of the prior art.

This object is achieved by a transfer film having the features of patent claim 1, the use of such a transfer film according to patent claim 12, a film of patent claim 13, a security document of patent claim 14, and a method for producing a transfer film of patent claim 15.

The transfer layer comprising the at least one first color layer may be transferred from the support layer to a target substrate, such as a security document, by means of an embossing operation. As a result, the widespread embossing technique, in particular hot embossing or cold embossing, can be used to apply the transfer layer to the security document. As a result, the security against counterfeiting of the security document is further increased, since an additional, difficult-to-forge layer with a viewing angle-dependent color appearance is applied, but without a corresponding printing process is necessary. This allows a reduction in costs, since instead of a complex printing technique, the embossing technique can be used to apply the stamping foil. In contrast to screen printing, the embossing technique is a dry process, so that potential burdens due to, for example, solvents, their use possibly by country-specific environmental laws and by a non-existent infrastructure may be limited, omitted. Furthermore, the influence of the surface of the target substrate, such as the roughness, is reduced, since in the production of the transfer film on a known material, in particular on the carrier film is printed with determinable properties, which align the pigments better and thus the optical effect is improved. Also, the intercoat adhesion in the area of the color layer can be improved by a suitable choice of material of the corresponding transfer layers.

Among the at least first pigments whose color appearance changes as a function of the viewing angle, in particular pigments are understood here which, due to interference effects, produce a color effect that is dependent on the viewing angle. In order to produce such a color-changing effect with high brilliance, the pigments must have a similar orientation to each other. Such pigments are, for example, optically variable pigments (engl optically variable pigment -. OVP).

In this case, a binder is understood as meaning a liquid material which contains various pigments and which can be transferred together with the pigments by means of a printing process. Such compounds of binders and pigments are, for example, optical variable inks (engl optically variable ink -. OVI®) which generate especially by interference effects an optically variable color impression. Typically, OVIs must be printed in large film thicknesses to produce a recognizable, high brilliance color-changing effect.

The term viewing angle is here understood to mean both the angle at which the ink layer on the transfer film or the security document is viewed by a viewer, and the angle at which the ink layer on the transfer film or the security document is illuminated by a lighting device. The viewing angle is understood to be the angle enclosed between the surface normal of the transfer film or of the security document and the viewing direction of an observer. Likewise, the viewing angle is understood to mean the angle enclosed between the surface normal of the transfer film or the security document and the illumination direction of a lighting device. Thus, for example, a viewer looks perpendicular to the surface of the transfer film or the security document at the viewing angle of 0 °, and at a viewing angle of 70 °, a viewer looks at the transfer film or the security document at a shallow angle. For example, a lighting device illuminates the surface of the transfer film or the security document at an acute angle at the viewing angle of 45 °. If the viewing direction of the observer or the illumination direction of the illumination device changes, the viewing angle consequently changes.

According to a further preferred embodiment of the invention, the first pigments have a diameter between 1 .mu.m and 100 .mu.m, preferably between 5 .mu.m and 50 .mu.m, and a thickness between 0.1 .mu.m and 5 .mu.m, preferably between 0.3 .mu.m and 2.5 μm, up.

Furthermore, it is possible for the at least one first color layer to contain second pigments, in particular flakes, taggants and / or charms. hereby the security against forgery of a security document having the transfer layer is improved, since such a color layer is difficult to imitate.

Flakes are hereby understood as meaning multilayer flakes which produce a viewing angle-dependent color change, for example from green to violet.

Taggants are here understood to mean markers which are not recognizable to the unaided human eye but can be detected by various other methods of determination. Examples include photochromic, thermochromic, luminescent and magnetic markers. For example, thermochromic markers change the color appearance with temperature changes. As Taggants here are also other markers, which can be detected for example by means of a spectral analysis, a biochemical analysis or forensic analysis methods understood.

Charms are here understood to mean pigments which have patterns, motifs and / or characters.

According to a further preferred embodiment of the invention, the at least one first color layer contains third pigments which, when irradiated with electromagnetic radiation, in particular irradiation with UV or IR light (UV = ultraviolet, IR = infrared), light from the range of human Eye visible wavelength range, especially in the wavelength range of 400 nm to 800 nm emit. As a result, the security against forgery of the transfer layer having Improved security document, since such a color layer is difficult to imitate.

The proportion of the at least first pigments in the at least one binder of the at least one first color layer is preferably less than 50%, preferably less than 30%, more preferably less than 15%.

Furthermore, it is possible that the at least one first color layer contains soluble dyes in the at least one binder. As a result, for example, the color change impression of the color layer can be influenced. Thus, for example, a color change from green to brown produced by the first pigments in the at least one first color layer may be influenced by the at least one first color layer containing soluble dyes which additionally colorize the layer green and thereby enhance the green color impression at a first viewing angle and leave the brown color impression unchanged under a second viewing angle.

Furthermore, it is advantageous if the first pigments are formed in the shape of platelets and a surface normal fixed relative to the plane spanned by the transfer layer has a substantially similar orientation to one another. As a result, a high brilliance of the optically variable effect is achieved.

Preferably, the orientation of the first pigments relative to the plane defined by the transfer layer plane set surface normals and spanned by the transfer layer coordinate system is locally varied. As a result, interesting and memorable optical effects are achieved and so that the security against forgery of a security document having the transfer position increases. Such a variation of the alignment can be achieved for example by changing the parameters of the printing process. For example, an alignment of the first pigments during the printing process can take place in that a pressure roller has an additional macroscopic surface relief which during printing deforms the material to be printed and / or the pigments in the binder not yet fixed. For this purpose, for example, the use of a reactive binder may be advantageous. In this case, the reactive binder is fixed by electromagnetic radiation, in particular by irradiation with UV light, and thus the orientation of the first pigments is likewise fixed. Another way to locally vary the orientation of the first pigments is, for example, the use of magnetic pigments.

Furthermore, it is possible that the first pigments are magnetic and / or have one or more metal layers. This makes it possible, for example, as described above, to vary the pigments locally. In this case, the magnetic pigments can be aligned, for example, by means of a correspondingly formed magnetic field, in which the transfer film is located with the color layer having the pigments. The binder can be fixed in this case, for example, after appropriate alignment of the pigments as described above, for example by means of UV light.

According to the invention, the at least one first color layer is present in at least a first region of the transfer layer and is absent in at least a second region of the transfer layer. This makes it possible, for example, for the at least one first color layer to be present in the first plurality of regions and for the at least one second region to be present in the first region Transfer position is not available. For example, there may be a multiplicity of first regions in which the at least one first color layer is present, the first regions being enclosed by a second region. Furthermore, it is possible that the at least one second region of the transfer layer encloses the at least one first region of the transfer layer.

Thus, it is possible that a large areal proportion of the transfer film can be printed with the at least one first color layer, since the first areas can be applied with a small distance from each other. The second areas accordingly occupy a small areal proportion of the transfer film. In this way, the area of the transfer layer of the transfer film can be optimally utilized in a printing step. As a result, a cost reduction can be achieved, since OVIs used, in particular in the high-security area, such as bank notes, are expensive. Likewise, when applying the at least one first color layer, no consideration must be given to the document layout of the security document since the transfer layer comprising the at least one first color layer is transferred to the desired location on the security document by embossing on the target substrate only later. This simplifies the transfer process to the security document as there is no need to print on the security document. This further allows an increase in productivity, since when applying the transfer layers on the security document, the slow screen printing method with the typically low printing areas per unit area on the security document is replaced by a stamping process. As a result, the costs are further reduced because on the one hand, the complex printing process is avoided and on the other hand, the committee - for example due to a lack of pressure on the security documents - is reduced. In addition, possible misprints can be detected early on a review of the transfer film and sorted out accordingly before the transfer layer is transferred to the security document. This will further reduce the rejection of security documents and costs. Detected misprints can be sorted out, for example, by sorting out entire film rolls provided with the transfer foils or by skipping individual faulty transfer foils on the rolls having the transfer foils when the transfer layer is applied to the security document.

In this case, the term area is understood to mean a defined area which, when viewed perpendicularly, the transfer film, i. at a viewing angle of 0 ° of an applied layer. For example, the color layer forms an area that occupies a defined area when viewing the transfer film vertically. In other areas, additional layers may be applied, such as a metal layer or another pressure, which, for example, from a feinlinigen security printing, z. B. consists of fine guilloche.

Preferably, the at least one first color layer is applied by screen printing. Furthermore, it is possible for the at least one first color layer to be applied by means of further methods, such as gravure, flexographic printing, pad printing or high-pressure.

Preferably, the at least one first area represents first information, in particular in the form of a pattern, motif or lettering. Thus, it is possible that the at least one first region is shaped like a pattern.

Thus, it is possible that the shape of the first area constitutes information. Such information may be for example a letter formed from letters. As a result, the security against forgery of a security document, on which the transfer layer is applied, further increased because targeted, for example, logos appear differently colored from different viewing angles to the viewer.

Furthermore, the transfer layer has a first compensation layer, which covers the at least one first region of the transfer layer and the at least one second region of the transfer layer. This makes it possible, at least partially compensate for the layer thicknesses of the ink layer, which are typically required for high brilliance of the desired optically variable effect compared to other layers of the transfer film or layers with diffractive structures and to stabilize the overall transfer layer.

Furthermore, the layer thickness of the first compensating layer is in the range of 10% to 50% of the thickness of the at least one first color layer.

It has surprisingly been found that despite the small layer thickness of the compensating layer in comparison to the color layer, the compensating layer still exhibits a stabilizing effect. In addition, this achieves the smallest possible layer thickness of the transfer layer. This is particularly advantageous since the thickness of the security document to which the transfer layer is transferred changes only slightly due to the applied transfer layer. Furthermore, this can improve the embossing process, since thinner transfer layers can typically be cut better.

Stabilization of the transfer layer, in particular mechanical stabilization of the transfer layer, is understood to mean that the hardness and strength of the transfer layer are increased. For example, layers of polycarbonate, especially at elevated temperatures, under which polycarbonate layers are laminated, have little stabilizing effect, since they exert little resistance to deformation. Chemically crosslinked layers of acrylates, on the other hand, have a stabilizing effect due to their higher strength.

Surprisingly, it has been found that the optically variable effect in terms of different color appearance at different viewing angles after transfer to a target substrate, such as a security document, is significantly more pronounced compared to direct printing on the target substrate. By transferring further layers, such as the leveling layer, the stability of the transfer layers is improved, so that the alignment of the pigments to each other is improved, whereby the brilliance of the color change effect is improved. The reason for this is that the compensation layer compensates for the roughness of the surface of the target substrate and / or reduces the effect of the roughness of the surface on the transfer layer due to the mechanical stability. In particular, when the target substrate, such as a plastic layer of polycarbonate on which the transfer layer is applied, is laminated with another plastic layer, a much better color change effect is achieved compared to direct printing on the target substrate. The lamination is carried out at high temperatures and pressures, whereby the plastic is soft and the color layer is deformed with the pigments contained therein. As a result, the orientation of the pigments is changed within the ink layer and consequently the color change effect is reduced. By means of the leveling layer, the color layer is now stabilized, so that after the lamination process, the pigments continue to be aligned with each other in a similar manner and the brilliance of the optically variable effect is thereby optimized. Furthermore, it is possible that different layer thicknesses of the at least one first color layer are compensated by such a compensation layer. As a result, for example, fluctuations in the layer thickness of the ink layer can be compensated for, so that a flat surface is formed by the compensating layer with respect to a coordinate system spanned by the transfer layer.

Furthermore, provision can be made for the first compensation layer and / or the second compensation layer to comprise fourth pigments which, when irradiated with UV light or IR light, emit light from the range of the wavelength range visible to the human eye.

Furthermore, it is advantageous that at least one second color layer is present in at least a third region of the transfer layer and is absent in at least a fourth region of the transfer layer, wherein the at least one third region of the transfer layer overlaps or at least overlaps the at least one first region of the transfer layer a third region of the transfer layer does not overlap the at least one first region of the transfer layer. This makes it possible, for example, to transfer two different color change effects having color layers with the transfer layer by a single embossing process. Here, the security against counterfeiting is further increased, while preserving the processing advantages of the embossing technique.

Furthermore, it is possible for the transfer layer to have a second compensation layer, which is in the at least one fourth region of the transfer layer at least the layer thickness of the at least one second color layer in the at least one third region of the transfer layer corresponds.

It is also possible for the first compensation layer and / or the second compensation layer to have a layer thickness between 0.5 μm to 15 μm, preferably 0.5 μm to 7.5 μm, more preferably 1.5 μm to 5 μm. Such layer thicknesses are, as described above, smaller than the layer thickness of the at least one first color layer and nevertheless achieve a stabilizing effect.

Furthermore, it is advantageous if the first compensation layer and / or the second compensation layer are transparent and / or colorless. As a result, viewing the color layers through the compensation layers is possible and / or the target substrate can be seen through the compensation layers.

Preferably, the first compensating layer and / or the second compensating layer is formed as an adhesive layer, in particular an adhesive layer. This makes it possible for the compensation layer, in addition to the function of compensating the roughness of the surface of the target substrate and / or the compensation of the layer thicknesses, which is caused in particular by the required thicknesses of the ink layer, to assume the function of an adhesive layer with which the transfer layer is applied to a target substrate.

According to a further preferred embodiment of the invention, the transfer layer has a first adhesive layer on the surface facing away from the carrier layer.

In this case, an adhesive layer is understood as meaning a layer which connects layers between which the adhesive layer is arranged. Thus, it is possible that the adhesive layer is an adhesive layer.

Furthermore, it is advantageous that the adhesive layers, in particular adhesive layers, for example acrylates, PVC, polyurethane or polyester include.

According to a further preferred embodiment of the invention, the at least one first color layer has a thickness of between 3 μm and 30 μm, preferably 5 μm and 15 μm. This ensures that the optically variable effect of the color layer is particularly pronounced or achieves a high brilliance.

Preferably, further color layers, for example a second color layer and / or a third color layer, have a thickness between 3 μm and 30 μm, preferably 5 μm and 15 μm.

According to the invention, the transfer layer has at least one first stabilization layer, which mechanically stabilizes the transfer layer. This further stabilizes the transfer layer and further improves the brilliance of the color change effect after transfer to a target substrate. Furthermore, it is possible that the first stabilizing layer serves as a protective layer, in particular as a protective layer against solvents or mechanical damage.

The at least one first stabilization layer is preferably arranged between the carrier layer and the at least one first color layer.

Furthermore, it is possible for a second stabilization layer to be applied on the side of the at least one first color layer which is remote from the at least one first stabilization layer. This further stabilizes the transfer layer, in particular for large-area transfer layers, and further improves the brilliance of the color change effect after the transfer to a target substrate.

Furthermore, it is advantageous that the at least one first stabilization layer is applied to the side of the at least one first color layer which is remote from the carrier layer.

The at least one first stabilization layer and / or the second stabilization layer preferably has a layer thickness between 0.2 μm and 7.5 μm, preferably 0.4 μm and 5 μm, more preferably 0.6 μm and 4 μm. Such layer thicknesses achieve a sufficient stabilizing effect, so that the optically variable effect of the color layer in the transfer layer is improved compared to a direct printing of the color layer.

It is also possible for the at least one first stabilization layer and / or the second stabilization layer to be crosslinked, in particular chemically and / or crosslinked by irradiation with UV light and / or irradiation with electron beams. For example, layers comprising acrylates, polyesters, polyvinyl alcohols or alkyd resins are chemically crosslinked by means of isocyanate. In addition, for example, layers comprising polymethyl acrylate, dipentaerythritol pentaacrylate or polysiloxane resin and a photoinitiator such as Irgacure are crosslinked by means of UV light. Also, epoxy resins can be used as chemically crosslinked layers.

Furthermore, it is advantageous for the layer thickness of the first and / or second stabilization layer and / or the materials of the first and / or second stabilization layer and / or the properties of the first and / or second stabilization layer to be dependent on the further layers of the transfer layers or of the target substrate choose. For example, a particularly stiff stabilizing layer is advantageous if the further layers of the transfer layers are soft and have little supportive effect. A particularly smooth stabilization layer is to be selected, for example, with a high roughness of the target substrate. In particular, target substrates of polycarbonate may have a roughness in the range of 10 microns to 20 microns and thereby affect the visual appearance of the pigments in the ink layer. The influence of roughness is significantly reduced by the use of a suitably shaped stabilizing layer.

Furthermore, it is advantageous if the at least one first stabilization layer and / or the second stabilization layer is a layer hardened by electromagnetic radiation, in particular by irradiation with UV light.

Preferably, the at least one first stabilization layer and / or the second stabilization layer are transparent or translucent.

According to a further embodiment of the invention, the transfer layer has a primer layer.

Preferably, the at least one first color layer is applied to the primer layer. As a result, the intercoat adhesion of the color layer can be adjusted in a targeted manner and thereby improved - for example, by optimizing for the OVI to be printed on.

Furthermore, it is possible for the primer layer to have a layer thickness between 0.01 μm and 0.5 μm, preferably 0.03 μm and 0.25 μm, more preferably 0.04 μm and 0.08 μm.

According to a further exemplary embodiment of the invention, the carrier layer has a layer thickness between 12 μm and 50 μm, preferably 15 μm and 25 μm. Examples of the carrier layer are carrier layers made of PET, PEN, OPP, BOPP, PE or cellulose acetate. The carrier layer may also itself comprise a plurality of partial layers.

According to a further embodiment of the invention, the transfer layer comprises a release layer which enables the separation of the transfer layer from the carrier layer. Examples of the release layer are release layers of cellulose buturate, acrylates, nitrocellulose, ethyl acetate, butyl acetate or styrene copolymer. In particular, after the transfer layer has been transferred to a target substrate, the release layer, starting from the target substrate, represents the uppermost layer and can fulfill or provide further functions, such as the overprintability with further layers. In the case of lamination or bonding of the target substrate with a further film, the release layer also serves as an adhesive layer for attachment to the applied further film.

The release layer preferably has a layer thickness between 0.2 μm and 4 μm, preferably 0.5 μm and 2.5 μm, more preferably 0.8 μm and 2.0 μm.

According to a further exemplary embodiment of the invention, a separating layer, in particular a wax layer, is on the carrier layer Silicone layer and / or a curable by means of UV light or electron beam coating layer applied, which allows the separation of the transfer layer of the carrier layer.

According to a further exemplary embodiment of the invention, the at least one first color layer may have an individual marking. This marking can be produced, for example, by locally removing the applied ink layer according to the marking by means of a laser beam. In particular, such an identifier may include a barcode and / or alphanumeric characters and may include, for example, a serial number. This individual identification ensures, in particular, traceability. However, an identification can also be generated by means of a printing process, such as by inkjet. The marking can be carried out both in the first areas and in the other areas and, for example, be visually recognizable or only visible under UV irradiation. The pressure may in particular take place between the release layer and the at least first color layer or on the side facing away from the carrier of the at least first color layer.

Furthermore, it is possible for the at least one first color layer to form a raster image.

According to a further exemplary embodiment of the invention, the transfer layer has at least one replication lacquer layer. As a result, the stability of the transfer layer can be further increased.

Furthermore, it is possible for a surface structure to be molded into the surface of the replication lacquer layer in at least a fifth region of the transfer layer. As a result, the security against forgery of a transfer document having security document is further increased, since another hard-to-imitate security element is present.

Preferably, in the at least one first region of the transfer layer, the surface structure is not molded into the surface of the replication lacquer layer.

Furthermore, it is possible that the at least one fifth region of the transfer layer does not overlap with the at least one first color layer. The surface structure in the surface of the replication lacquer layer in the at least one fifth region of the transfer layer is thus present only in regions in the transfer film which do not have the at least one first color layer.

Furthermore, it is advantageous if the refractive index of the replication lacquer layer deviates from the refractive index of the binder by less than 0.2, preferably by less than 0.1. This makes it possible to extinguish the optically variable effects of the surface structures molded into the surface of the replication lacquer layer.

The surface structure is preferably selected from the group of diffractive surface structures, in particular Kinegram® or holograms, zeroth order diffraction structures, blazed gratings, in particular linear or crossed sinusoidal diffraction gratings, linear or crossed single- or multi-level rectangular gratings, asymmetrical sawtooth relief structures, diffractive and / or refractive / or light-focusing micro- or Nanostructures, binary or continuous Fresnel lenses, binary or continuous Fresnel freeform surfaces, diffractive or refractive macrostructures, in particular lens structures or microprism structures, mirror surfaces and matt structures, in particular anisotropic or isotropic matt structures, or combinations of these structures.

Furthermore, it is possible that the at least one fifth region of the transfer layer represents a second information in the form of a pattern, motif or lettering. As a result, the security against forgery of a security document, on which the transfer layers are applied, is further increased, since, for example, the shaping of the at least one fifth region forms a second information in the form of a motif.

The replication lacquer layer is preferably thermoplastically deformable and / or crosslinked, in particular crosslinked by irradiation with UV light. In particular, by crosslinking, the stability of the transfer layer can be further increased.

Furthermore, it is advantageous that the replication lacquer layer has a layer thickness between 0.2 μm and 4 μm, preferably 0.3 μm and 2 μm, more preferably 0.4 μm and 1.5 μm.

The transfer layer preferably has a reflection layer in at least a sixth region of the transfer layer, the area occupancy of the at least one sixth region of the transfer layer being less than 30%, preferably less than 20%, of the total area of the transfer layer. The reflective layer is preferably a metal layer of chromium, gold, copper, silver or an alloy of such metals, which in Vacuum in a layer thickness of 0.01 microns to 0.15 microns is evaporated. Such a partial metallization can be, for example, a metallic nanotext. The area occupancy ensures that the color-changing effect of the color layers in the at least one first area and / or at least one third area is not impaired by the at least one sixth area.

Further, it that the reflection layer is formed by a transparent reflecting layer is also possible, for example, a thin or fine structured metallic layer or an HRI or LRI layer (engl high refraction index -. HRI, low refraction index - LRI). Such a dielectric reflection layer consists for example of a vapor-deposited layer of a metal oxide, metal sulfide, titanium oxide, etc. with a thickness of 10 nm to 150 nm.

It is also possible for the reflection layer to be applied in the at least one sixth region of the transfer layer on the side of the at least one first color layer which is remote from the carrier film. This makes it possible, for example, to superimpose the first region with a metallization. Since the layers of paint are typically applied by screen printing with large layer thicknesses, accurate printing is made more difficult. Thus, it is possible to improve the contours of the ink layer in the first region of the transfer layers, for example, by applying a partial metallization to the ink layer, which can be applied with high accuracy.

Furthermore, it is advantageous that the at least one sixth region of the transfer layer represents a third piece of information in the form of a pattern, motif or lettering.

It is also advantageous if the transfer layer has at least one mark in at least one seventh region of the transfer layer for determining the relative position or position of the at least one first region of the transfer layer and / or of the at least one third region of the transfer layer and / or of the at least one fifth transfer layer Area of the transfer layer and / or the at least one sixth area and / or the at least one eighth area of the transfer layer contains. These registers thus represent register marks or register marks. Register or registration accuracy or register or register accuracy is the positionally accurate arrangement of superimposed or adjacent layers relative to one another while maintaining a desired positional tolerance.

Preferably, the marks are formed from a printed material, from a surface relief, from a magnetic or conductive material. For example, the marks may be optically readable register marks, which differ from the background by their color value, their opacity or their reflection properties. The markers can also be a macroscopic or diffractive relief structure which deflects the incident light in a predetermined angular range and optically differs from the background region due to these properties. However, the register marks may also be register marks detectable by means of a magnetic or a sensor that detects the electrical conductivity. The marks are for example by means of an optical sensor, a magnetic sensor or a mechanical sensor, a capacitive sensor, or a conductivity detecting sensor detected and the application of the transfer layer is then controlled by means of the brands. It is particularly advantageous if the register marks are applied in the same operation, in which the at least one color layer is applied. The application takes place in the same operation with the same tool, so that thereby register fluctuations or register fluctuations between the motif and register mark are minimized.

According to a further embodiment of the invention, the transfer layer has a photopolymer layer.

Furthermore, it is possible for the photopolymer layer to have a volume hologram in at least one eighth area of the transfer layer. As a result, the security against forgery of a transfer document having security document is further increased, since further optical effects are generated.

Furthermore, it is advantageous that the at least one fifth region of the transfer layer at least partially overlaps with the at least one eighth region of the transfer layer or that the at least one fifth region of the transfer layer does not overlap with the at least one eighth region of the transfer layer.

According to a further embodiment of the invention, the transfer layer is present in at least one first zone and is absent in at least one second zone, wherein the at least one first zone of the transfer layer is patterned.

Advantageously, the transfer layer is severed by punching along the border lines formed by the first and second zones. In this case, the transfer layer is severed by means of a punch, which forms the shape of the first zone, and the second zone, which is not to be transferred, is removed. The punching can be done by mechanical action with a punch or performed by laser processing. Punching is advantageous in particular for non-complex motifs, since a strong fraying at the motif edges, which impairs the visual appearance, scarcely occurs. In such a case, the area of the color layer is typically larger than the motif to be punched out so that the area having the color layer completely encloses the at least one first zone. Furthermore, it is possible for the at least one first zone to completely surround the area containing the color layer, so that in this case the motif is determined by the shape of the color layer. Mixed forms are also advantageous, so that in one subarea the motif is determined by the punching and in a further subarea the motif is determined by the shape of the color layer.
Furthermore, it is advantageous if not only the motif is determined by the punching, but at the same time the register marks are punched in the same operation.

Furthermore, it is advantageous that the transfer layer is completely severed by means of punching along one of the boundary lines which defines the at least one first zone of the transfer layer and which separates the at least one first zone from the at least one second zone of the transfer layer.

Preferably, the carrier layer is cut through less than 50%. As a result, a possible tearing is prevented in the removal of the carrier layer.

According to a further exemplary embodiment of the invention, one or more transfer films according to the invention are used for application to a film, in particular having a first surface and a second surface.

Furthermore, it is possible for the one or more transfer films to be applied to the first surface and / or to the second surface of the film. Thus, for example, the application of the transfer layers of the transfer films can take place on one side of the film or on two opposite sides of the film. It is also possible that the transfer films are applied on both sides of the film. Thus, it is possible to provide several, in particular differently constructed transfer films on one or both opposite sides of the film. For example, transfer films with diffractive surface structures formed in a replicate lacquer layer and a reflection layer can be provided on one side of the film, and transfer films with a color layer comprising a binder and optically variable pigments on the opposite side of the film.

Furthermore, it is possible for at least one first transfer film of the one or more transfer films which is applied to the first surface of the film to overlap or overlap with at least one second transfer film of the one or more transfer films applied to the second surface of the film does not overlap.

Further, it is advantageous that the film is applied together with the one or more applied transfer films on a security document or incorporated into a security document. A detachment of the one or more transfer films from the film does not take place here.

Furthermore, it is possible for the one or more transfer layers of the one or more transfer films to be applied to the film, wherein the film further security features selected from the group diffractive surface structures, in particular Kinegram® or holograms, zero order diffraction structures, Blazegitter, preferably linear or crossed sinusoidal diffraction grating, a linear or crossed single or multi-level rectangular grid, an asymmetric sawtooth relief structure, a light diffractive and / or refractive and / or light focusing micro or nanostructure, a binary or continuous Fresnel lens, a binary or continuous Fresnel freeform surface; has diffractive or refractive macrostructures, lens structures, microprism structures, mirror surfaces and matt structures, in particular anisotropic or isotropic matt structures, or a combination structure comprising a plurality of the aforementioned surface structures. As a result, the advantages of the particular use of the embossing technique as an application method in comparison to a printing method can be used. The film, which has further security features, in turn, for example, by means of a stamping technique or by lamination applied to a security document or incorporated into a security document, so that it is possible to extend existing security elements by applying the transfer layer of the transfer film according to the invention or their counterfeit protection continue to increase.

It is also advantageous that one or more transfer films with the side of the carrier layers facing away from the transfer layers of the one or more transfer films are applied to the second surface of the film and a second adhesive layer is applied between the one or more transfer films and the film bonding one or more transfer sheets to the film, wherein the adhesive force of the second adhesive layer exceeds the adhesive force between the one or more transfer sheets and the one or more carrier sheets of the one or more transfer sheets, or vice versa.

In the event that the adhesive force of the second adhesive layer exceeds the adhesive force between the one or more transfer layers and the one or more carrier layers of the one or more transfer films, it is achieved that the one or more transfer films can be applied specifically to a target substrate. For this purpose, transfer films with the side facing away from the film are applied to a target substrate, so that after removal of the film, the transfer layers remain adhered to the target substrate. As a result, for example, ready-made transfer layers can be used to secure security documents that can be personalized, for example, with a photograph or other personal data.

For the converse case that the adhesive force of the second adhesive layer is less than the adhesive force between the one or more transfer layers and the one or more carrier layers of the one or more transfer films, it is achieved, as an alternative to the variant described above, that the one or more transfer films together be applied with their carrier layers as self-supporting elements targeted to a target substrate can. For this purpose, transfer films with their carrier layers with the side facing away from the film are applied to a target substrate, so that after the film has been removed, the transfer layers with their carrier layers adhere to the target substrate. As a result, for example, prefabricated self-supporting transfer layers can be used to secure security documents that can be personalized, for example, with a photograph or other personal data.

The transfer film according to the invention can be applied to security documents, in particular banknotes, identity cards, identity cards, check cards, credit cards, visas, certificates or vignettes or else to commercial products or product packaging.

Furthermore, it is possible that security documents are produced or can be produced with one or more transfer films according to the invention.

It is also possible for one or more transfer layers of the one or more transfer films according to the invention to be arranged on a surface of a first carrier substrate made of paper or plastic, in particular polycarbonate, PET, polypropylene, polyethylene or Teslin.

The one or more transfer layers arranged on the surface of the first carrier substrate are preferably connected, in particular laminated or glued, to a plastic layer, in particular a polycarbonate layer or a PET layer.

Fig. 1

zeigt eine schematische Schnittdarstellung einer Transferfolie

Fig. 2a bis Fig. 2c

zeigen schematische Darstellungen zur Verdeutlichung der Verwendung einer Transferfolie

Fig. 3a bis Fig. 6b

zeigen schematische Schnittdarstellungen von Transferfolien

Fig. 7a und Fig. 7b

zeigen schematische Darstellungen zur Verdeutlichung der Verwendung einer Transferfolie

Fig. 8a und Fig. 8b

zeigen schematische Schnittdarstellungen einer Transferfolie

Fig. 9a bis Fig. 9c

zeigen schematische Draufsichten einer Transferfolie

Fig. 10

zeigt eine schematische Schnittdarstellung eines Sicherheitsdokuments zur Verdeutlichung der Verwendung einer Transferfolie

Fig. 11

zeigt eine schematische Schnittdarstellung eines Sicherheitsdokuments zur Verdeutlichung der Verwendung einer Transferfolie

In the following, exemplary embodiments of the invention will be described by way of example with the aid of the enclosed FIGS FIGS. 3a to 6b and 9a to 9c explained, wherein the embodiments of the remaining figures are only intended to facilitate the understanding of the invention.

Fig. 1

shows a schematic sectional view of a transfer sheet

Fig. 2a to Fig. 2c

show schematic representations to illustrate the use of a transfer film

Fig. 3a to Fig. 6b

show schematic sectional views of transfer films

Fig. 7a and Fig. 7b

show schematic representations to illustrate the use of a transfer film

Fig. 8a and Fig. 8b

show schematic sectional views of a transfer film

Fig. 9a to Fig. 9c

show schematic plan views of a transfer film

Fig. 10

shows a schematic sectional view of a security document to illustrate the use of a transfer film

Fig. 11

shows a schematic sectional view of a security document to illustrate the use of a transfer film

Fig. 1 1 shows a transfer film 1 with a carrier layer 10, a wax layer 22 and a transfer layer 20, which comprises a release layer 24, a color layer 30 and an adhesion layer 92.

The carrier layer 10 is preferably a PET, PEN, OPP, BOPP, PE or cellulose acetate film having a thickness of between 12 μm and 50 μm. At the in Fig. 1 shown carrier layer 10 is a PET film with a layer thickness of 19 microns.

On the carrier layer 10, the wax layer 22 and the transfer layer 20 are then applied successively by applying further layers. The wax layer 22 in this case has a thickness of 10 nm. Typical layer thicknesses for the wax layer 22 are in the range of 1 nm to 100 nm. A release layer 24 having a thickness of 0.2 μm to 2 μm is applied to the wax layer 22. At the in Fig. 1 Release layer 24 shown is a thermoplastic release layer 24 having a thickness of 0.95 microns. The wax layer 22 together with the release layer 24 ensures separation from the carrier layer 10. The release layer 24 represents the uppermost layer, in particular after the transfer layer 20 has been transferred. For example, the wax layer softens as a result of the heat occurring during a hot embossing process, thereby achieving a reliable separation of the release layer 24 from the wax layer 22.

The ink layer 30 is preferably a layer of OVI having a thickness between 3 μm and 30 μm. The color layer 30 thus comprises a binder and pigments whose color appearance changes depending on the viewing angle and in particular generates a color change effect.

The pigments in the ink layer 30 preferably have a diameter between 1 .mu.m and 100 .mu.m. The color change effect of the pigments may appear to a human observer, for example, from green to brown or from green to violet. The pigments of the color layer 30, which produce such a color change effect, are hereby preferably aligned substantially similar to one another in relation to the surface normal defined by the transfer layer 20. However, the orientation of the pigments relative to one another can be varied locally, for which purpose the pigments can be magnetic, for example.

It is also possible that the color layer 30 contains further pigments, such as, preferably, flakes, charms, taggants, reflective pigments or platelet-shaped pigments which have a diffractive structure.

Furthermore, it is possible that the color layer 30 contains pigments which, when irradiated with electromagnetic radiation, in particular irradiation with UV or IR light, light from the range visible to the human eye wavelength range, in particular in the wavelength range of 400 nm to 800 nm , emit. Also, the ink layer 30 may contain, for example, soluble dyes which, for example, color the ink layer 30 in accordance with the accompanying dyes. In the Fig. 1 shown ink layer 30 has a layer thickness between 10 .mu.m and 12 .mu.m. The Ink layer 30 can be applied for example by means of a screen printing process.

Subsequently, the adhesive layer 92 is applied with a layer thickness of about 2 microns to 8 microns. In the Fig. 1 shown adhesive layer 92 has a layer thickness of 4.5 microns. The adhesive layer 92 is preferably made of a thermally activatable adhesive and is applied over the entire surface, for example by means of a doctor blade to the layer 30. In this case, it is possible that the adhesive layer has a compensatory effect on the layer thickness of the ink layer 30, if this has, for example, variations in the layer thickness. The adhesive layer 92 is preferably a layer of acrylate, PVC, polyurethane or polyester.

The transfer layer 20 can be transferred to a target substrate by hot stamping, for example. Furthermore, it is possible to transfer the transfer layer 20 by means of a cold transfer. For this purpose, for example, a UV-curable adhesive can be used as the adhesive layer. In the case of cold transfer, but also in hot stamping, the adhesive layer may preferably either be part of the transfer layer or else alternatively be applied to the target substrate or additionally. Curing of the UV-curing adhesive may be through the ink layer provided that the ink layer has sufficient transmission for UV light, or through the target substrate, as long as the target substrate is at least partially transparent to UV light. The latter is particularly suitable for polymer substrates, such as polycarbonate, polyester, polyethylene or polypropylene.

The adhesive layer 92 may also be patterned onto the target substrate, for example, by a printing operation. This method is suitable especially when used by cold transfer. However, it can also be used for thermally activatable adhesives in hot stamping.

Fig. 2a to Fig. 2c illustrate the use of a transfer sheet 1 according to another embodiment of the invention. Fig. 2a 1 shows a transfer film 1 with a carrier layer 10, a wax layer 22 and a transfer layer 20, which comprises a release layer 24, a color layer 30 and a compensation layer 90.

In the embodiment of Fig. 2a For example, the transfer layer 20 has three areas 40 and four areas 42 enclosing the areas 40. The number of regions 40 and regions 42 is selected here purely by way of illustration. It is thus possible, for example, for only one area 40 and one area 42 to be present, or for a multiplicity of areas 40 and areas 42 to be present. The regions 40 here represent the part of the transfer layer 20 which has the ink layer 30.

The leveling layer 90 is preferably a layer of acrylate, PVC, polyurethane or polyester, which is also present in a smaller layer thickness, in particular in a smaller layer thickness than the color layer 30, whereby the areas 40 and 42 are covered and the areas 42 only covered, but not filled.

Furthermore, it is possible for the leveling layer 90 to be a layer of polymethyl acrylate, dipentaerythritol pentaacrylates or polysiloxane resin which has a photoinitiator such as Irgacure and can be crosslinked by means of UV light. Alternatively, the leveling layer of acrylate, polyester, polyvinyl alcohols or alkyd resins exist and are chemically crosslinked by means of isocyanate. In such a case, the transfer layer would additionally have an adhesive layer, which is applied to the leveling layer 90. Regarding the configuration of such an adhesive layer is here on the embodiments of Fig. 1 directed.

The Fig. 2b now shows the top view of the transfer sheet 1 of Fig. 2a , As in Fig. 2b Shown here, the color layer 30 is applied here in pattern form in the form of the letters "CH" in the regions 40. Furthermore, in three areas 43 marks 50 are applied, which serve to determine the areas 40. The marks 50 represent register marks or register marks, by means of which the exact position of superimposed or adjacent layers relative to each other can be detected while maintaining a desired positional tolerance.

With respect to the configuration of the carrier layer 10, the wax layer 22, the release layer 24 and the color layer 30 is here on the embodiments of Fig. 1 directed.

Fig. 2c Now shows the top view of a security document 2, to which a region 45 of the transfer layer 20 of Fig. 2a and Fig. 2b is applied. The security document 2 is a security document made of polycarbonate. The region 45 of the transfer layer 20, which comprises one of the regions 40 and a partial region of the regions 42, is transferred, for example, by hot stamping onto the security document 2 by means of a hot stamping die. The shape of the area 45 is determined by the stamp shape of the hot stamping die. The transmission takes place, for example, by optically detecting one of the marks 50 by means of an optical sensor which detects the marks 50, for example by their opacity in comparison to the marks 50 Areas 42, detected and then controls the application of the area 45 of the transfer layer 20 by means of the stamping die. In Fig. 2c Now, the area 45 of the transfer layer 20 is applied to the security document 2, so that the security document 2 now has the letter "CH" having a color change effect.

Fig. 3a to Fig. 6b show various embodiments of the transfer film according to the invention 1. The Fig. 3a, Fig. 4a . Fig. 5a and Fig. 6a show the various embodiments of the transfer film 1 before separation of the transfer layers 20 and the Fig. 3b, Fig. 4b . Fig. 5b and Fig. 6b show the corresponding embodiments after separation of the transfer layers 20th

In the in Fig. 3a In the exemplary embodiment shown, the transfer film 1 comprises a carrier layer 10, a wax layer 22 and a transfer layer 20, which comprises a release layer 24, a stabilization layer 60, a replication lacquer layer 70, a primer layer 80, a color layer 30 and a compensation layer 90.

The stabilization layer 60 is preferably a layer of acrylate, polyester, polyvinyl alcohols or alkyd resins, which is chemically crosslinked, for example, by means of isocyanate. Further, for example, layers of polymethyl acrylate, dipentaerythritol pentaacrylate or polysiloxane resin provided with a photoinitiator such as Irgacure can be used. By means of the photoinitiator, such a stabilization layer can be crosslinked by irradiation by means of UV light. The stabilization layer 60 preferably has a layer thickness between 0.2 μm and 5 μm. At the in Fig. 3a shown Stabilizing layer is a chemically crosslinked stabilizing layer with a thickness of about 0.7 microns.

The replication lacquer layer 70 consists of a thermoplastic lacquer in which a surface structure is molded by means of heat and pressure by the action of an embossing tool. Furthermore, it is also possible for the replication lacquer layer 70 to be formed by a UV-crosslinkable lacquer and for the surface structure to be shaped into the replication lacquer layer 60 by means of UV replication. The surface structure is molded onto the uncured replication lacquer layer by the action of an embossing tool and the replication lacquer layer is cured directly during or after the impression by irradiation with UV light.

The replication lacquer layer 70 preferably has a layer thickness between 0.2 μm and 2 μm. The layer thickness of the replication lacquer layer 70 in FIG Fig. 3a is 0.5 microns and it is an at least partially chemically crosslinked Replizierlackschicht. The surface structure molded into the replication lacquer layer 70 is preferably a diffractive surface structure, for example a hologram, Kinegram® or another diffraction-optically active lattice structure. Such surface structures typically have a spacing of the structural elements in the range of 0.1 μm to 4 μm. Furthermore, it is also possible for the surface structure to have a zero order diffraction structure, a blazed grating, a preferably linear or crossed sinusoidal diffraction grating, a linear or crossed single or multi-level rectangular grid, an asymmetric sawtooth relief structure, a light-diffractive and / or refractive and / or light-focusing micro- or nanostructure, a binary or continuous Fresnel lens, a binary or continuous Fresnel lens continuous Fresnel freeform surface; a diffractive or refractive macrostructure, in particular lens structure or microprism structure, a mirror surface or matt structure, in particular anisotropic or isotropic matt structure or a combination structure of a plurality of the aforementioned surface structures. The surface structures formed in the replication lacquer layer 70 are shown in FIG Fig. 3a formed in a region 44 which is enclosed by the regions 42, and is thus present when viewed perpendicularly to the transfer film adjacent to the ink layer having regions 40.

Furthermore, it is possible for a reflection layer to be applied to the replication lacquer layer 70. The reflection layer is preferably a metal layer of chromium, gold, copper, silver or an alloy of such metals, which is vapor-deposited in vacuo in a layer thickness of 0.01 μm to 0.15 μm. Further, it that the reflection layer is formed by a transparent reflecting layer is also possible, for example, a thin or fine structured metallic layer or an HRI or LRI layer (engl high refraction index -. HRI, low refraction index - LRI). Such a dielectric reflection layer consists for example of a vapor-deposited layer of a metal oxide, metal sulfide, titanium oxide, etc. of a thickness of 10 nm to 150 nm.

The primer layer 80 is a layer which preferably comprises acrylates, PVC, polyurethane or polyester and has a layer thickness between 0.01 μm and 0.5 μm. In the Fig. 3a shown primer layer has a layer thickness of 0.06 microns.

Regarding the design of the other layers in Fig. 3a Reference is made here to the above statements.

The transfer film 1 of the embodiment of Fig. 4a corresponds to the transfer sheet 1 of the embodiment of Fig. 3a with the difference that the transfer film according to Fig. 4a does not have a replicate varnish layer.

The transfer film 1 of the embodiment of Fig. 5a corresponds to the transfer sheet 1 of the embodiment of Fig. 4a with the difference that the compensating layer 90 is formed as a stabilizing layer and the transfer layer 20 additionally has an adhesive layer 92. For this purpose, the compensation layer 90 is formed from the material of the stabilization layer as described above, and the stabilization layer 60 between the release layer 24 and the primer layer 80, as in FIG Fig. 4a shown is removed. With regard to the configuration of the adhesive layer 92, reference is made here to the above statements.

The transfer film 1 of the embodiment of Fig. 6a corresponds to the transfer sheet 1 of the embodiment of Fig. 4a with the difference that the wax layer 22 has been replaced by a lacquer layer 23 curable by means of UV light or electron beams.

Fig. 7a and Fig. 7b illustrate the use of a transfer film 1 on another film 12. Fig. 7a shows a plan view of a film 12, the Fig. 7b a cross section of the film 12. On the film 12, as in Fig. 7b recognizable, one or more transfer sheets 1 applied. The one or more transfer films 1 are connected to the carrier layers 10 with the film 12 by an adhesive layer. On the carrier layers 10 of the one or more transfer films 1 are applied the transfer layers 20 which comprise the release layers 24, the color layers 30 and the compensation layers 90. As in Fig. 7a Recognizable, the film 12 has marks 50, which may preferably be formed as rectangles, lines or strips and extend transversely to the longitudinal direction of the film web, which forms the film 12. The one or more transfer films 1 applied to the film 12 can now be applied to a target substrate. When the film 12 is removed, the transfer layers 20 separate from the carrier layers 10 of the one or more transfer films 1 and the transfer layers are transferred to the target substrate according to their arrangement on the film 10. The carrier layers 10 of the one or more transfer films 1 remain on the film 12.

It can also be provided that the arrangement of the adhesive layer between the carrier layers 10 and the film 12 and the release layer 24 between the carrier layers 10 and the transfer layers 20 is reversed. Thus, in each case a release layer is arranged between the film 12 and the carrier layers 10 and the carrier layers 10 are connected to the transfer layers 20 in each case by an adhesive layer. As a result, when applied to a target substrate, the carrier layers 10 are transferred from the film 12 together with the transfer layers 20 and thus the carrier layers 10 become part of the transfer layers 20. Consequently, 10 self-supporting small areas are transferred by the carrier layers. The mechanical stability of the transfer layers 20 is thereby increased by the carrier layers 10 transferred.

Fig. 8a and Fig. 8b show sectional views of a transfer film according to another embodiment of the invention. The transfer film 1 of Fig. 8a and Fig. 8b consists of a carrier layer 10, and a transfer layer 20, which a release layer 24, a color layer 30 and a leveling layer 90 includes. With regard to the configuration of the layers, reference is made here to the above statements. As in Fig. 8a 1, the transfer layer 20 of the transfer film 1 is cut along the boundary line formed by three zones 46 and four zones 48. Preferably, the transfer layer 20 is severed by punching. The punching can be done by means of a mechanical tool or by means of a laser. As in Fig. 8a As shown in FIG. 4, the area 40 comprising the ink layer 30 surrounds each of the three zones 46. The shape of the punch thus defines the shape of the zones 46. The number of zones 46 and zones 48 is chosen here purely by way of illustration. It is thus possible, for example, for only one zone 46 and one zone 48 to be present, or for a multiplicity of zones 46 and zones 48 to be present. As in Fig. 8b As shown, the transfer layers 20 of the zones 48 can be removed so that only the transfer layers 20 of the zones 46 remain on the carrier layer 10. These can then be transferred to a target substrate, for example by means of an embossing process.

Fig. 9a and Fig. 9c show schematic plan views according to another embodiment of the invention.

Fig. 9a shows a transfer film 1, which in three areas 40 has a color layer and in the areas 44 each have a Kinegram®. The areas 44 are as in Fig. 9a represented within the area 42, in which no color layer is applied. The color layer is here applied in the form of the letters "CH" in the regions 40 within the transfer layers and the Kinegram® elements are embossed in the form of a pattern in the regions 44 into a replicate lacquer layer of the transfer layers. Furthermore, in regions 43, marks 50 are applied which serve to determine the relative position of regions 40 and 44. As in Fig. 9a can be seen, thus points each security feature in the form of the letters "CH" forming areas 40 and the Kinegram® elements forming areas 44 each have a separate mark 50. This makes it possible for the letters "CH", which form a first security feature, and the Kinegram® elements, which form a second security feature, to be separately recorded and stamped. This can be done for example with two different embossing stamps.

The transfer film 1 of the embodiment of Fig. 9b corresponds to the transfer sheet 1 of the embodiment of Fig. 9a with the difference that the regions 40 forming the letters "CH" and the regions 44 comprising the Kinegram® elements together have a common mark 50. As a result, each one of the color layer having areas 40 and the Kinegram® having a region 44 is detected and stamped together. This can be done for example with a common die.

The transfer film 1 of the embodiment of Fig. 9c corresponds to the transfer sheet 1 of the embodiment of Fig. 9b with the difference that within the area 42, in which no color layer is applied, more areas 47 and 49 are present. The areas 47 are metallized areas 47 in the form of the word "Swiss". In addition, it is possible, for example, that the lettering is designed as nanotext and thus is not visible to the unaided human eye. Furthermore, the transfer film in the areas 49 has a second color layer in the form of a cross. Thus, the transfer film 1 has a first ink layer in the regions 40 and a second ink layer in the regions 49. Preferably, the pigments of the first and second differ Color layer, so that different color effects in the first areas 40 and 49 areas are perceptible.

Fig. 10 shows a schematic sectional view of a security document 2, on which a transfer layer 20 of a transfer film 1 according to the invention is applied. The transfer layer 20 is applied to a carrier substrate 14. The carrier substrate 14 may be, for example, a paper-based carrier substrate 14, such as a passport, visa, banknote or certificate. It is also possible for the carrier substrate 14 to be a plastic substrate, such as, for example, polycarbonate, PVC, PET, or PET-G. The carrier substrate 14 may also be a hybrid substrate made of paper and plastic layers, wherein either a paper layer or a plastic layer forms the outermost layer to which the transfer layer 20 is applied. The transfer layer 20 has a release layer 24, a stabilization layer 60, a replication lacquer layer 70, a primer layer 80, a color layer 30 and a compensation layer 90. With regard to the configuration of the layers, reference is made here to the above statements.

Fig. 11 shows a schematic sectional view of a security document 2, in which a transfer layer 20 of a transfer film 1 according to the invention is laminated. The transfer layer 20 is applied to a carrier substrate 14 made of plastic, such as polycarbonate. Subsequently, the carrier substrate 14 is laminated with one or more further plastic layers 16 to form a composite. The transfer layer 20 has a release layer 24, a color layer 30 and a compensation layer 90. With regard to the configuration of the layers, reference is made here to the above statements.

LIST OF REFERENCE NUMBERS

1

transfer film

2

The security document

10

backing

12

foil

14

carrier substrate

16

Plastic layer

20

transfer position

22

wax layer

24

release layer

30

coat of paint

40, 42, 43, 44, 45 47, 49

areas

46.48

zones

50

brand

60

stabilizing layer

70

replication

80

primer layer

90

leveling layer

92

adhesive layer

Claims (15)

1. Transfer film (1), in particular hot-stamping film, comprising a transfer ply (20) detachably arranged on a carrier layer (10), wherein the transfer ply (20) has at least one first colour layer (30), and wherein the at least one first colour layer (30) comprises at least one binding agent and at least first pigments, whose coloured appearance changes depending on the angle of observation, wherein the at least one first colour layer (30) is present in at least one first region (40) of the transfer ply (20), and no colour layer is present in at least one second region (42) of the transfer ply (20), wherein the transfer ply (20) has a first compensation layer (90) which covers the at least one first region (40) of the transfer ply (20) and the at least one second region (42) of the transfer ply (20), and wherein the layer thickness of the first compensation layer (90) ranges from 10% to 50% of the layer thickness of the at least one first colour layer (30).
2. Transfer film (1) according to claim 1,
   characterised in that
   the at least one first region (40) represents a first piece of information, in particular represents it in the form of a pattern, motif or lettering.
3. Transfer film (1) according to one of claims 1 or 2,
   characterised in that
   at least one second colour layer is present in at least one third region of the transfer ply (20) and is not present in at least one fourth region of the transfer ply (20), wherein the at least one third region of the transfer ply (20) overlaps with the at least one first region (40) of the transfer ply (20), or the at least one third region of the transfer ply (20) does not overlap with the at least one second region (42) of the transfer ply (20), and the transfer ply (20) preferably has a second compensation layer which, in the at least one fourth region of the transfer ply (20), corresponds at least to the layer thickness of the at least one second colour layer in the at least one third region of the transfer ply (20), and the second compensation layer preferably has a layer thickness between 3 µm and 50 µm, preferably 5 µm and 25 µm, further preferably 7 µm and 20 µm.
4. Transfer film (1) according to one of the preceding claims,
   characterised in that
   the first compensation layer (90) and/or the second compensation layer is transparent and/or colourless, and/or the first compensation layer (90) and/or the second compensation layer is formed as a bonding layer, in particular an adhesive layer.
5. Transfer film (1) according to one of the preceding claims,
   characterised in that
   the transfer ply (20) has at least one first stabilising layer (60) which mechanically stabilises the transfer ply (20), and the at least one first stabilising layer (60) is preferably arranged between the carrier layer (10) and the at least one first colour layer (30), or the at least one first stabilising layer (60) is applied to the side of the at least one first colour layer (30) facing away from the carrier layer (10).
6. Transfer film (1) according to claim 5,
   characterised in that
   the at least one first stabilising layer (60) and/or the second stabilising layer is cross-linked, in particular chemically cross-linked and/or cross-linked by irradiation with UV light and/or irradiation with electron beams, and/or the at least one first stabilising layer (60) and/or the second stabilising layer is a layer cured by electromagnetic radiation, in particular by irradiation with UV light, and/or the at least one first stabilising layer (60) and/or the second stabilising layer is transparent or translucent.
7. Transfer film (1) according to one of the preceding claims,
   characterised in that
   the transfer ply (20) comprises a detachment layer (24) which enables the separation of the transfer ply (20) from the carrier layer (10).
8. Transfer film (1) according to one of the preceding claims,
   characterised in that
   the transfer ply (20) has at least one replication lacquer layer (70).
9. Transfer film (1) according to claim 8,
   characterised in that,
   in at least one fifth region of the transfer ply (20), a surface structure is moulded into the surface of the replication lacquer layer (70), and, in the at least one first region (40) of the transfer ply, the surface structure is preferably not moulded into the surface of the replication lacquer layer (70), or the refraction index of the replication lacquer layer (70) deviates from the refraction index of the binding agent by less than 0.2, preferably by less than 0.1, and/or the at least one fifth region of the transfer ply (20) preferably represents a second piece of information in the form of a pattern, motif or lettering.
10. Transfer film (1) according to one of the preceding claims,
    characterised in that,
    in at least one sixth region of the transfer ply (20), the transfer ply (1) has a reflection layer, wherein the surface coating of the at least one sixth region of the transfer ply (20) is less than 30%, preferably less than 20%, of the total area of the transfer ply (20), and, in the at least one sixth region of the transfer ply (20), the reflection layer is preferably applied to the side of the at least one first colour layer (30) facing away from the carrier film (10), and/or the at least one sixth region of the transfer ply (20) preferably represents a third piece of information in the form of a pattern, motif or lettering.
11. Transfer film (1) according to one of the preceding claims,
    characterised in that
    the at least one first colour layer (30) contains second pigments, in particular flakes, taggants and/or charms, and/or the at least one first colour layer (30) contains third pigments which emit light from the range of the wavelength range that is visible to the human eye, in particular in the wavelength range of 400 nm to 800 nm, in the event of irradiation with electromagnetic radiation, in particular irradiation with UV or IR light, and/or the transfer ply (20) is present in at least one first zone (46) and is not present in at least one second zone (48), wherein the first zones (48) of the transfer ply (20) are formed in the shape of a pattern.
12. Use of one or more transfer films (1) according to one of claims 1 to 11 for applying to a film.
13. Film having a first surface and a second surface, wherein one or more transfer films (1) according to one of claims 1 to 11 having the side of the carrier layers (10) facing away from the transfer plies (20) of the one or more transfer films (1) are applied to the second surface of the film, and a second bonding layer is applied between the one or more transfer films (1) and the film, said bonding layer connecting one or more transfer films (1) to the film, wherein the bonding force of the second bonding layer exceeds the bonding force between the one or more transfer plies (20) and the one or more carrier layers (10) of the one or more transfer films (1), or vice versa.
14. Security document (2), in particular bank note, identity document, identity card, cheque card, credit card, visa, certificate, vignette, produced with one or more transfer films (1) according to one of claims 1 to 11, wherein one or more transfer plies (20) of the one or more transfer films (1) are preferably arranged on a surface of a first carrier substrate (14) made of paper or plastic, in particular made of polycarbonate, and the one or more transfer plies (20) arranged on the surface of the first carrier substrate (14) are preferably connected, in particular laminated or adhered, to a plastic layer (16), in particular to a polycarbonate layer.
15. Method for producing a transfer film (1) according to one of claims 1 to 11, wherein, with the method, a carrier layer (10) is provided, which has a transfer ply (20), wherein at least one first colour layer (30) is applied to the side of the transfer ply (20) facing away from the carrier layer, wherein the at least one first colour layer (30) comprises at least one binding agent and at least first pigments, the colour appearance of which changes depending on the angle of observation, wherein the at least one first colour layer (30) is present in at least one first region (40) of the carrier ply (20), and there is no colour layer present in at least one second region (42) of the transfer ply (20), wherein the transfer ply (20) has a first compensation layer (90) which covers the at least one first region (40) of the transfer ply (20) and the at least one second region (42) of the transfer ply (20), wherein the layer thickness of the first compensation layer (90) ranges from 10% to 50% of the layer thickness of the at least one first colour layer (30), and wherein the at least one first colour layer (30) is preferably applied by means of screen printing, and/or the transfer ply (20) is completely severed by means of punching along a boundary line defining the at least one first zone (46) of the transfer ply (20) and separating the at least one first zone (46) from the at least one second zone (48) of the transfer ply (20).

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