EP3279003B1 - Security element and method for manufacturing a security element - Google Patents

Description

The invention relates to a method for producing a security element, in which a first microstructure is produced on a front side and a reflector layer is applied over it.

The invention further relates to a security element which comprises a first structurable layer which is applied on a front side, a first microstructure in a surface of the first structurable layer and a first reflector layer on the first microstructure.

Such structures for reflective holograms are known in the prior art. They use micro-optical effects for security elements and are usually created by embossing a metal layer or by embossing and subsequent vapor deposition (PVD) of a metal layer on the embossed structure. The metal layer can be subsequently structured by laser ablation.

In WO 2005/1081 09 A1 A laser marking extends over the border area between a coating and the security paper. A security element on a substrate is in DE 10 2010 053 052 A1 modified with the help of a laser and an opening is also created in the substrate. EP 2 889 152 A1 shows a grid of optically effective elements, in which a local defect is introduced by means of a laser. WO 2005/051675 A2 discloses printing a metallic nanoparticle ink on an embossed, diffractive structure.

The object of the invention is to provide a method for producing a security element and a security element so that manufacturability, security against imitation and visual appearance are improved.

The object is achieved by the subject matter of the independent claims. The dependent claims describe preferred configurations.

The method for producing a security element comprises the following steps: provision of a first structurable layer, generation of a first microstructure in a front side of the first structurable layer, application of a first reflector layer to the first microstructure in a first pattern that is recognizable when viewed from the front , In the present case, the first reflector layer is applied by printing in the first pattern with a homogeneous thickness. In a further step, the first reflector layer is removed by means of laser ablation, a second pattern, which can be seen in a view of the front, being generated in the first reflector layer.

An advantage of the method for producing the security element is that two authenticity features are generated. A first authenticity feature is the reflector layer in the first pattern. The first pattern preferably relates to an outline of the reflector layer, by means of which, for example, a geometrical shape or a contour of a person or an object can be recognized when viewed from above. The second authenticity feature arises from the removal of the first reflector layer in order to produce the second pattern, which can be seen in supervision. The second pattern can be a representation of the object or a geometry. The first pattern and the second pattern can complement one another to form an overall pattern. Both authenticity features are preferably recognizable to the naked eye for an observer. Another advantage is that the reflector layer thus has two optically effective (identically) microstructured surfaces. The microstructuring is effective as an authenticity feature when viewed from the front and can also be used as an authenticity feature when viewed from the rear.

It is advantageous to print reflective nanoparticles and / or pigments that adapt and reflect, in particular metallic, microstructures. The pigment that adapts to microstructures, including the first microstructure, is so thin or flexible that it follows the contour of the microstructure. Such nanoparticles or contour-matching pigments are known, for example, from EP 1689586 B1 . WO 2010/069823 A1 and WO 2013/090983 A1 ,

The microstructure is preferably produced by embossing.

In one configuration, the first structurable layer is provided on a substrate. These steps of the procedure need not be carried out in the order given. In further developments, it is also possible to generate the microstructure in a structurable layer and, optionally, to transfer the layer structured in this way to the substrate.

A substrate, such as paper, can be non-transparent, but can have at least one transparent section. A substrate, such as a film, can alternatively be transparent.

The security element can be a data carrier, such as a security thread, a label, a transfer element or a security print. The substrate can be configured as any thin-surface element that is suitable for supporting the first structurable layer and the first reflector layer. For example, the substrate can be a paper, in particular a cotton paper, or a film made of polyethylene (PE), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polypropylene (PP) or polyamide (PA). The paper can do one Contain portion x artificial polymer material in the range of 0 <x <100 wt .-%. In particular, in addition to the natural polymer cellulose (polysaccharide), the paper can also contain a proportion of different polymer material in the range of 0 <x <100% by weight or consist entirely of artificial polymer fibers, for example Tyvek®. The film can be stretched monoaxially or biaxially. It can also contain different types of polymers, be co-extruded and / or thermo-laminated. The stretching of the film leads, among other things, to the fact that it obtains polarizing properties that can be used as a further authenticity feature. Tools required for the exploitation of these properties, such as. B. polarization filters are known to the person skilled in the art. In addition, the substrate can be a paper film composite or a film composite in which the substrate, the structurable layer and the reflector layer are embedded between two film layers.

How the microstructure (s) is (are) produced on the substrate is not essential to the invention. The use of a structurable layer on the substrate is particularly simple. A front side of the structurable layer (or the substrate with the structurable layer) corresponds to a front side of the security element. Insofar as the wording used above or below is viewed from the front (or the back), it is also to be understood in each case from the front (or the back) of the security element.

This structurable layer then optionally comprises an embossing lacquer, for example a UV embossing lacquer. However, the structurable layer can also comprise any other material which can be shaped by temperature, pressure, printing, laser treatment or other types of treatment in such a way that a microstructure can be produced therein. The structurable Layer can be transparent / translucent. It can also have a color which optionally does not interact with the laser radiation for laser ablation. The structurable layer is applied to the front of the substrate, wherein the front can be any side of the substrate and can alternatively also be referred to as the first side.

The microstructure is optionally a hologram structure for generating a holographic image of an object or a person. The holographic image represents a further authenticity feature. A hologram, for example a pictorial representation of an object or a person, can thus be recognized when viewed from above. However, the microstructure can also be a structure with microlenses, micromirrors or any other structure that has an order of magnitude in the micrometer or nanometer range. The microstructure can, for example, by means of printing or laser ablation on the substrate, e.g. B. are formed in the structurable layer. By applying the reflector layer to the microstructure, it is better under supervision or (for example in the case of a hologram) is optically effective in the first place. Insofar as a second or third microstructure (or a second or third hologram) is referred to below, this can also be a structure with microlenses, micromirrors or any other structure that has an order of magnitude in the micrometer or nanometer range.

In a preferred development, the surface area of the reflector layer can be larger than the microstructure, so that the microstructure is effective in a partial area of the reflector layer. The outline of the reflector layer is specified in the first pattern, which for example has a specific geometric shape or represents an object / person in cross section.

The first reflector layer is printed, taking care that its thickness is always the same, so that there is a homogeneous thickness. The thickness is z. B. along the local surface normal of the microstructure or along a normal to the plane in which the microstructure lies (this can be, for example, an upper side of the substrate).

Because of the homogeneous thickness, the surface structure of the security element before the application of the first reflector layer and after the application of the first reflector layer is identical, since the surface structure of the microstructure is retained due to the constant thickness of the first reflector layer. The microstructure is not leveled or replenished by the printing. Because of this, the first microstructure can be seen from both sides of the reflector layer, i. H. in a view of a front side of the security element and in a view through a transparent section through the substrate onto the first microstructure and the first reflector layer.

Methods for printing on the reflector layer, for example a metallic reflector layer, are described in the EP 1689586 B1 . WO 2010/069823 A1 and WO 2013/090983 A1 described, the disclosure content with respect to the printing process for applying the reflector layer with homogeneous thickness is fully included in this application. For example, a metallic ink can be printed on the first microstructure using conventional printing methods, for example using known printing presses. The metallic ink can comprise metallic pigment particles and a binder. The metallic particles can be metallic flat pigments (flakes) which adapt to microstructures and which comprise, for example, aluminum, stainless steel, gold, silver, platinum or copper. The metallic ink binder can be microcellulose, Contain vinyl chloride, vinyl acetate copolymers or vinyl. Silver nanoparticles, aluminum nanoparticles or titanium nanoparticles can also be used as metal particles for the metallic ink.

The second pattern is generated by partially or completely removing the thickness of the first reflector layer. The aim of this ablation is to increase the transmission of light in the removed area compared to the rest of the first reflector layer, so that the second pattern can be seen in a top view and a look through. During laser ablation, the microstructure is not changed due to the homogeneous thickness of the printed reflector layer. H. not removed, so that the effectiveness of the microstructure and the stability of the security element are retained.

This is achieved with the security element described here in that the first reflector layer has a homogeneous thickness and thus the intensity of the laser radiation can be set such that only the first reflector layer is removed and the microstructure underneath or other layers are not damaged. Due to the fact that the first reflector layer has a constant thickness, the same laser power can always be used to remove the first reflector layer uniformly. Furthermore, the microstructure can be opaque since, even if the laser ablation is operated at a constant intensity, damage to the microstructure cannot be expected due to the homogeneous thickness of the first reflector layer. The laser radiation for laser ablation can be generated, for example, with an infrared laser, a CO ₂ laser with a wavelength of approximately 10.6 μm or an Nd: YAG laser with a wavelength of 1.064 μm.

In addition to the first microstructure and the reflector layer, further layers can be provided in the security element, such as an adhesive layer for attaching a composite layer to the substrate, for example made of a PU adhesive, or an intermediate layer, for example made of a PET film. To protect against damage and soiling, the reflector layer can be covered with a cover layer made of an optically transparent color or a transparent layer.

In order to increase the security against forgery of the security element, the second pattern is applied in such a way that it can be seen through. For this purpose, it is provided that the substrate has a transparent or translucent section, which is arranged under the structurable layer, the first reflector layer being removed above the section, so that the second pattern can be seen through the section. The fact that the reflector layer is removed via the transparent or translucent section of the substrate means that the removed region of the reflector layer, which can represent a recess in the first reflector layer, is illuminated so that the second pattern can then be recognized particularly well. It is also in perfect register with the first sample. Furthermore, the first microstructure is not only recognizable when viewed from above, but also when viewed through it.

The transparent or translucent section can be, for example, a window, an area in an opaque substrate in which a transparent or translucent section is provided, or part of the transparent or translucent substrate. For example, any area of a transparent film can be considered the section. In the sense of the application, opaque is understood to mean a material which lets through a maximum of 5%, in particular a maximum of 2%, of visible light. Under transparent or translucent in the sense of the application, it is understood that a material in question transmits between 50%, in particular 90%, and 100% of the visible light. A transparent and translucent material differ in that an image is recognizable through the transparent material - the image information is retained after passing through the transparent material - this is not the case with a translucent material - the image information is lost through the translucent material. The section can also be designed to be translucent in that the substrate is opaque, but is so thin in the area of the section that light can shine translucently through the section. For example, the section can be part of a watermark.

In order to further increase the security against forgery of the security element, a composite structure similar to that on the front is preferably applied to a rear side of the security element. For this purpose, the following steps are preferably carried out: generating a second microstructure on a rear side of the substrate under a transparent or translucent section and printing a second reflector layer on the second microstructure with a homogeneous thickness in a third pattern, which is recognizable when viewed from the rear, wherein in the case of laser ablation, the second reflector layer is simultaneously removed by the laser radiation being guided through the section during laser ablation. Because the first reflector layer and the second reflector layer are removed by the same laser irradiation, the patterns in the first reflector layer and in the second reflector layer are exactly in register with one another.

With regard to the second microstructure and / or the second reflector layer, the above considerations apply to the first microstructure and / or the first reflector layer analog. The third pattern, in which the second reflector layer is applied, can be identical to the first pattern, so that an identical outline of the respective reflector layer can be seen on the front and the back. However, it is also possible for the third pattern to differ from the first pattern, so that different outlines of the respective reflector layer can be seen on the front and back. The material of the first reflector layer can be identical to that of the second reflector layer, although it is preferred that different materials are used for the first reflector layer and the second reflector layer, so that there are preferably different optical impressions of the first and second reflector layers. The second microstructure can also be introduced into a structurable layer, which is optionally attached to the back of the substrate above the section.

In this preferred embodiment, the section and / or the structurable layers are / are designed to be transparent, so that during laser ablation the first reflector layer and the second reflector layer are removed by the same laser irradiation step in that the laser radiation is guided through the section. For example, the laser radiation strikes the substrate perpendicularly, but it is also possible for the laser radiation to strike the substrate at a different angle, in particular between ± 30 ° and ± 60 ° to the normal, so that the second pattern can be seen at an angle , which corresponds to the angle of incidence of the laser radiation during laser ablation, is visible.

In order to further increase the security against forgery of the security element, it is preferred that the first reflector layer and / or the second reflector layer are / are applied in such a way that the first reflector layer in the have / has at least one recess in the first pattern and / or the second reflector layer in the third pattern. Since the section is transparent and / or translucent, the first microstructure would in principle be visible from the rear due to its homogeneous thickness, and the second microstructure would also be visible from the front in supervision. However, since the reflector layers are opaque, this is not possible. The cutouts are therefore provided in the first reflector layer and / or in the second reflector layer, so that the first microstructure can be seen through the cutout in the second reflector layer when viewed from the rear and / or the second microstructure through the cutout when viewed from the front recognizable in the first reflector layer. A second hologram of the second microstructure can thus be seen in the first microstructure which can be seen on the front. The same applies to the back. By providing the recesses in the first reflector layer and / or in the second reflector layer, a hologram can thus be recognized in the hologram when viewed from above. The at least one cut-out in the first reflector layer and / or in the second reflector layer can be applied during printing itself or subsequently by laser ablation. It is preferred that the first reflector layer and / or the second reflector layer are / are already printed with the cutouts on the first structurable layer or the second structurable layer.

If a substrate with a transparent section is assumed above or below, the further elements and configurations can be provided analogously for a transparent substrate. In this respect, a section of the transparent substrate that is not covered by opaque layers can also be understood as a transparent section.

In order to increase the security against forgery of the security element, it is preferred that the second reflector layer in reflection produces an optical impression different from the first reflector layer. For example, the color of the radiation reflected by the respective reflector layer can be different. Different materials are optionally printed for the first and second reflector layers. In the embodiment of the hologram in the hologram, the respective holograms then show different colors when viewed from above, so that they can be recognized particularly well. By using different colors, a bimetal effect can be created in the hologram in the hologram.

The counterfeit security of the security element can be further increased by performing the following steps: producing a third microstructure on the front of the substrate over the section and printing a third reflector layer on the third microstructure with a homogeneous thickness in a fourth pattern, which is viewed from above the front side can be seen, the third reflector layer being removed during laser ablation and the first reflector layer and / or the third reflector layer being applied such that the first reflector layer in the first pattern and / or the second reflector layer in the fourth pattern has at least one Have / has recess.

With regard to the third structurable layer, the third microstructure and the third reflector layer, analogous considerations apply as have been put forward for the first or second structurable layer, the first or second microstructure and the first or second reflector layer. The fourth pattern may be identical to the first pattern and / or the third pattern, but it is preferred that the fourth pattern is different from the first pattern and / or the third pattern. The fourth pattern can serve as another authenticity feature. Because the second pattern is performed by laser ablation of the first reflector layer and the third reflector layer simultaneously with a laser beam, the second patterns are exactly in register in the first reflector layer and the third reflector layer.

The recess in the first reflector layer and / or the third reflector layer also produces a hologram in the hologram, as previously described. The first reflector layer (together with the first structurable layer) is optionally arranged between the third reflector layer (together with the third structurable layer) and the substrate. In this embodiment, a hologram of the first microstructure is visible in the hologram of the third microstructure by applying the recess in the third reflector layer when viewed from the front. When viewed from the rear, a hologram of the third microstructure can be recognized in the hologram of the first microstructure due to the cutouts in the first reflector layer.

A particularly simple arrangement of the first reflector layer and the third reflector layer results if the first reflector layer is arranged between the first and the third microstructure. In a preferred development, the first reflector layer is in direct contact with the first and the third microstructure. This results in a preferred construction of the security element, in which the first microstructure lies under the first reflector layer, which in turn is arranged under the third macrostructure, which in turn is arranged under the third reflector layer.

Another arrangement of the first and third layers is preferably carried out by providing a transparent carrier layer between the first and the third microstructure. The carrier layer can be, for example, a film, in particular a PET film, which has a thickness of 6 μm, for example. The microstructures are attached to the carrier layer, the respective reflector layers in turn being applied to the microstructures. The first reflector layer thus faces the back and the third reflector layer the front.

In order to produce a bimetal effect to further increase the security against counterfeiting, it is preferred that a fourth reflector layer, which in reflection produces a different optical impression from the first reflector layer, the second reflector layer and / or the third reflector layer, over the first reflector layer in some areas second reflector layer and / or the third reflector layer is printed with a homogeneous thickness, the fourth reflector layer optionally being removed simultaneously during laser ablation. The fourth reflector layer can be printed on the first, the second, or the third reflector layer or on all reflector layers. Since the fourth reflector layer and the respective underlying reflector layer each have a homogeneous thickness, the surface of the fourth reflector layer has the same structure as the microstructure underneath. The microstructure can thus be seen from above even when the fourth reflector layer is printed on.

In a further development, the fourth reflector layer differs in reflection from the reflector layer on which it is applied in its optical impression. For example, the fourth reflector layer differs from the reflector layer on which it is applied in its colored perception, so that bimetal effects can be produced. In In the fourth reflector layer and / or in the first, second or third reflector layer, at least one cutout is also provided, which can be introduced as described above. Depending on the reflector layer in which the recess is made, the bimetal effect can be seen from the front or the back when viewed from above.

A further authenticity feature can preferably be generated in that a laser radiation-sensitive layer, which changes the color in the case of laser radiation, is provided and the color is changed by the laser ablation. The laser radiation-sensitive layer can comprise, for example, laser-modifiable effect pigments or pigment-free laser-modifiable marking substances. Examples of suitable marking substances and the manner in which they are applied and / or introduced onto the substrate are given in the publication WO 2010/072329 A1 described in more detail, the disclosure content of which is included in the present application.

The laser radiation-sensitive layer can be applied under the microstructure or over the reflector layer. The layer sensitive to laser radiation in particular changes its color due to the laser radiation from the laser ablation. For example, the laser radiation-sensitive layer can be blue before exposure to the laser radiation and red after exposure to it. In addition, it is possible for the layer sensitive to laser radiation to be transparent before exposure to the radiation from the laser ablation and to become colored after interaction with the radiation from the laser ablation. Since the color change of the laser radiation-sensitive layer occurs through laser ablation, the area of the laser radiation-sensitive layer whose color is changed is in exact registration with the second pattern.

The features and advantages described in this application can be achieved with the security element as described in the DE 102010053052 A1 be described, combined. To this extent, this publication is included in the present application. That according to DE 102010053052 A1 inserted hole in the substrate is preferably closed again with a film. The combination is particularly interesting for composite substrates if the features explained in this invention are introduced under a film as an internal security feature.

In addition, the object is achieved by a security element which has a substrate, a first structurable layer which is applied to a front side of the substrate above the section, a first microstructure in a surface of the first structurable layer and a first reflector layer which is applied to the first Microstructure is printed with a homogeneous thickness, includes. The first reflector layer is printed in a first pattern, which can be seen when viewed from the front. The first reflector layer has a recess in the form of a second pattern above the cutout, which can be seen when looking through the section.

With regard to the security element, the advantages listed above, preferred embodiments and variants apply analogously.

Fig. 1

eine Draufsicht auf eine Vorderseite eines Sicherheitselements;

Fig. 2a, 2b

Schnittdarstellungen zweier weiterer Ausführungsformen des Sicherheitselements;

Fig. 3

eine vergrößerte Schnittdarstellung einer Ausführungsform des Sicherheitselements zur Illustration einer Reflektorschicht;

Fig. 4

Schnittdarstellungen einer weiteren Ausführungsform des Sicherheitselements;

Fig. 5

eine Schnittdarstellung einer Ausführungsform des Sicherheitselements;

Fig. 6

eine Schnittdarstellung einer weiteren Ausführungsform des Sicherheitselements;

Fig. 7

eine Schnittdarstellung einer Ausführungsform des Sicherheitselements; und

Fig. 8a, 8b

eine Schnittdarstellung einer Ausführungsform des Sicherheitselements vor und nach einer Laserablation.

Further exemplary embodiments and advantages of the invention are explained below with reference to the figures, in the illustration of which a true-to-scale and proportioned reproduction has been dispensed with in order to increase clarity. Show it:

Fig. 1

a plan view of a front of a security element;

2a, 2b

Sectional representations of two further embodiments of the security element;

Fig. 3

an enlarged sectional view of an embodiment of the security element to illustrate a reflector layer;

Fig. 4

Sectional representations of a further embodiment of the security element;

Fig. 5

a sectional view of an embodiment of the security element;

Fig. 6

a sectional view of another embodiment of the security element;

Fig. 7

a sectional view of an embodiment of the security element; and

8a, 8b

a sectional view of an embodiment of the security element before and after laser ablation.

A security element 10, as is shown in various embodiments in FIGS 1 to 8 may be part of a value document or an entire value document, such as a bank note, an identification card or the like. The security element 10 has a substrate 12 which can extend over the entire value document or can be connected to the value document.

When viewed from the front, a first reflector layer 14 can be seen, which can be printed in particular as metallic, for example with metallic effect pigments. The first reflector layer 14 has a homogeneous thickness d, ie the thickness d is constant everywhere. The thickness D can e.g. B. along a normal to an area of the first microstructure 16, as is particularly good in Fig. 3 is recognizable. With regard to the exemplary embodiments for the material of the first reflector layer 14 and their method of manufacture, reference is made to the EP 1689586 A1 , the WO 2013/090983 A1 and the WO 2011/064162 A2 directed. The first reflector layer 14 is applied with an outline in the form of a first pattern; in Fig. 1 the first pattern is a curved star, but it is also possible that other geometric shapes or the contour of a person, an object or an animal or the like are used for the first pattern. The first reflector layer 14 with the first pattern represents an authenticity feature of the security element 10.

In addition, a first microstructure 16 can be seen in the view of the security element 10, which is shown in FIG Fig. 1 is symbolized as a triangle. The first microstructure 16 can have any shape and represents objects, a person or an animal holographically in order to thereby increase the security against forgery of the security element 10. The first microstructure 16 can be designed as a hologram structure; the hologram of the first microstructure 16 is a further authenticity feature of the security element 10. Since the first reflector layer 14 has the constant thickness d, the first reflector layer 14 has a surface structure which is identical to that of the first microstructure 16, as shown in FIG Fig. 3 is shown as an example. The first microstructure 16 can thus be seen in principle in supervision and in review.

A recess 18 in the form of a second pattern is machined in the reflector layer 14 Fig. 1 is shown as a half ring. The recess 18 and thus the second pattern can be seen through. The second pattern can be of any design and represents a further authenticity feature of the security element 10.

In one embodiment, the substrate 12 is made of an opaque material, for example paper, in particular cotton paper, and has a basis weight of 68 g / m ² , for example.

At the in Fig. 2a In the embodiment shown, the substrate 12 has a transparent or translucent section 20 which is made of a plastic, in particular a plastic film such as polyethylene (PE). In addition, it is also possible for the section 20 to be a window in the substrate 12. In another embodiment of the security element 10, which in Fig. 2b is shown, the substrate 12 is made entirely of a transparent or translucent material, for example plastic, in particular a plastic film such as polyethylene (PE) or a film banknote substrate made of stretched polypropylene film (BOPP) with a basis weight of 70 g / m ² . The section 20 forms part of the substrate 12 in this embodiment.

In the 2a and 2b In the embodiment shown, a first structurable layer 22 is applied directly to the front of the substrate 12 and a second structurable layer 28 is applied to an opposite back, which can optionally also be omitted. However, it is also possible for the layers to be applied to the substrate 12 by means of adhesive and further layers, as will be explained below by way of example. The first structurable layer 22 is configured in such a way that the first microstructure 16 is introduced therein, e.g. B. is impressed. For example, the first layer 22 is produced from a UV embossing lacquer with a basis weight of 5.0 g / m ² . In this embodiment, the first layer 22 is transparent in the region above the section 20.

In the 2a and 2b In addition to the first reflector layer 14 and the first layer 22 with the first microstructure 16, a second reflector layer 24 and a second microstructure 26 are also provided in a second structurable layer 28. The second reflector layer 24 has an outline in the form of a third pattern, which represents a further authenticity feature of the security element 10. The thickness d of the second reflector layer 24 is constant, so that the second reflector layer 24 has a surface structure that is identical to the second underlying microstructure 26, analogous to that in FIG Fig. 3 exemplary representation shown. The second microstructure 26 can be designed as a hologram structure; The hologram of the second microstructure 26 also serves as an authenticity feature and can be identical or different to that of the first microstructure 16. The second reflector layer 24 can be made of the same materials as the first reflector layer 14. The third pattern of the second reflector layer 24 may be identical to the first pattern of the first reflector layer 14, but it is also possible that the first pattern and the third pattern differ. A recess 18 is also provided in the second reflector layer 24, which is identical to the recess 18 in the first reflector layer 14. Since the transparent or translucent section 20 is provided between the recesses 18, the second pattern of the recess 18 can be seen as a authenticity feature. The second layer 28 is preferably configured analogously to the first layer 22.

The security element 10 of the 2a and 2b is produced by providing the substrate 12 with the transparent or translucent section 20. At least on the section 20, the first structurable layer 22 is applied on the front, in the surface of which the first microstructure 16 is provided. The first reflector layer 14 is then printed on the first structurable layer 22 with an outline in the form of the first pattern, as is shown, for example, in FIG EP 1689586 A1 , of the WO 2013/090983 A1 and the WO 2011/064162 A2 is described. Furthermore, the second structurable layer 28 is embossed on the back of the security element 10 at least over the section 20 and the second microstructure 26 is embossed on the surface thereof. The second reflector layer 24 is printed over the second structurable layer 28 with an outline in the form of the third pattern, as is shown, for example, in FIG EP 1689586 A1 , of the WO 2013/090983 A1 and the WO 2011/064162 A2 is described. The first reflector layer 14 and the second reflector layer 24 are then removed. This is done by using the arrows in 2a and 2b laser radiation shown is passed through the section 20 so that the first reflector layer 14 and the second reflector layer 24 are removed simultaneously. Thus, the recesses 18 of the first reflector layer 14 and the second reflector layer 24 are in perfect registration. The laser radiation for the ablation can be generated, for example, with an infrared laser such as a CO ₂ laser with a wavelength of approximately 10.6 μm or an Nd: YAG laser with a wavelength of 1.064 μm.

In the Fig. 3 The embodiment of the security element 10 shown coincides with that in FIG 2a and 2b shown embodiment of the security element 10 except for the following differences. The security element 10 according to Fig. 3 has no second structurable layer 28, no second Microstructure 26 and no second reflector layer 24. Furthermore, no transparent section 20 is provided in the substrate 12. In addition, the substrate 12 is opaque. The recess 18 in the form of the second pattern can therefore not be recognized by looking through. The first structurable layer 22 can also be opaque. Damage to the first structurable layer 22 by the laser ablation for producing the recess 18 can also be minimized with a constant energy input from the laser ablation, since the first reflector layer 14 has a constant thickness d, so that if the power for the laser ablation is set correctly once, The first reflector layer 14 is only removed in the area of the second pattern via the expansion of the first reflector layer 14, but there is no interaction with the first structurable layer 22.

In the Fig. 4 The embodiment of the security element 10 shown is similar to that in FIG 2a and 2b shown embodiment, so that only the differences are discussed below. The second layer 28 with the second microstructure 26 and the second reflector layer 24 are in accordance with the security element 10 Fig. 4 not provided, but can be analogous to that in the 2a and 2b shown embodiment may be provided or, like the first layer 22 discussed below, be configured with the first microstructure 16 and the first reflector layer 14. The first layer 22 is colored in the region of the first reflector layer 14, so that the recess 18 can be seen in color when seen through. The first layer 22 can also be colored throughout. In addition to the first reflector layer 14, the security element 10 according to FIG Fig. 4 a fourth reflector layer 30 with a homogeneous thickness d is provided, so that the fourth reflector layer 30 has a surface structure that is identical to that of the first microstructure 16. The first reflector layer 14 and the fourth reflector layer 30 are configured differently, so that they produce a different optical impression for an observer in reflection. For example, the reflector layers 14, 30 can be made of different materials. The fourth reflector layer 30 can be applied in a pattern that is different or the same in the first pattern. Recesses 32 are provided in the first reflector layer 14 and / or the fourth reflector layer 30. These cutouts 32 produce a bimetal effect when viewed from above. A bimetal effect can be seen through the cutouts 32 in the fourth reflector layer 30 when viewed from the front, while a further bimetal effect can be seen through the cutouts 32 in the first reflector layer 14 when viewed from the rear, ie through the section 20. The bimetal effect is another authenticity feature.

The manufacture of the security element according to Fig. 4 is analogous to the manufacture of the security element in 2a and 2b , In addition, in the step of applying the first layer 22, the first layer 22 in the region of the first reflector layer 14 is colored, for example by introducing a colored pigment into the first layer 22. When the first reflector layer 14 is applied, the cutouts 32 are provided. This is optionally achieved by printing the cutouts 32, ie the cutouts 32 are pressure cutouts when the first reflector layer 14 is printed on. In addition, the cutouts 32 can be produced by ablation. The fourth reflector layer 30 is printed in analogy to the application of the first reflector layer 14. If both reflector layers 14 and 30 have been applied, the first reflector layer 14 and the fourth reflector layer 30 are removed by ablation. Since the ablation in the two reflector layers 14, 30 takes place simultaneously, the recesses 18 are in the first reflector layer 14 and in the fourth reflector layer 30 in perfect registration with one another.

Another embodiment of the security element 10 is shown in FIG Fig. 5 shown. This embodiment is similar to that in FIG Fig. 2a or 2b . shown The first layer 22 is colored in the region of the first reflector layer 14. The first reflector layer 14 is also provided with the recess 18 and the recess 32. The second layer 28 and the second reflector layer 24 are configured analogously. In addition, the security element 10 has an adhesive layer 34, an intermediate layer 36 and a cover layer 38 on the front and back. The adhesive layer 34 can be, for example, a PU adhesive with a weight of 4.5 g / m ² . The adhesive layers 34 serve to fasten the first layer 22 and the second layer 28 to the substrate 12. The intermediate layer 36 is provided on the adhesive layer 34, which can be, for example, a PET film with a thickness of 6 μm. The cover layer 38 is applied to the first reflector layer 14 and the second reflector layer 24 and serves to reduce damage and contamination of the reflector layers 14 and 24. The cover layer 38 can be an optically transparent color layer, for example. The adhesive layer 34 and the intermediate layer 36 are also designed to be transparent.

By providing the cutouts 32 in the first reflector layer 14 and the second reflector layer 24, the hologram of the first microstructure 16 is visible through the cutout 32 in the second reflector layer 24. The hologram of the second microstructure 26 can likewise be recognized through the cutout 32 in the first reflector layer 14. A hologram can thus be seen in the hologram from both sides, which represents a further authenticity feature. The hologram is on the front of the first microstructure 16 and that of the second microstructure 26 can be recognized by the cutout 32. The hologram of the second microstructure 26 and that of the first microstructure 16 through the recess 32 in the second reflector layer 24 can be seen from the rear. Are the first reflector layer 14 and the second reflector layer 24 made of different materials, such as in Fig. 4 the first reflector layer 14 and the fourth reflector layer 30, bimetal effects can also be produced by means of the cutouts 32. The holograms can be seen from both sides because the respective reflector layers 14, 24 have a homogeneous thickness d

The production of the security element 10 according to Fig. 5 is similar to that in 2a, 2b and 4 described manufacturing process. Therefore, only the differences are discussed below. Before the reflector layers 14 and 24 are printed, the adhesive layers 34 are first applied to the front and back of the substrate 12. The corresponding intermediate layers 36 are arranged on the respective adhesive layers 34. Subsequently, the first layer 22 is printed on the front and the second layer 28 on the back over the cutout 20 and colored in the area of the respective reflector layers 14 and 24. The first reflector layer 14 and the second reflector layer 24 are then applied with the cutouts 32 and finally covered with the cover layer 38. As a last step, the recesses 18 are made in the first reflector layer 14 and in the second reflector layer 24 by ablation, as described above, so that they are in exact registration.

In the Fig. 6 The embodiment of the security element 10 shown is similar to the previously described embodiments of the security element 10, so that only the differences are dealt with. According to the security element 10 Fig. 6 a third structurable layer 40, on the surface of which a third microstructure 42 is introduced, is provided on the first reflector layer 14. The third layer 40 is covered with a third reflector layer 44, which is printed with an outline in the form of a fourth pattern with a homogeneous thickness d. The fourth pattern can be analogous to or different from the first pattern. The third layer 40 can be configured like the first layer 22 or the second layer 28; The third reflector layer 14 can also be produced from the material of the first reflector layer 14 or the second reflector layer 24. The recesses 18 and the cutouts 32 are provided both in the first reflector layer 14 and in the third reflector layer 44. The cutout 32 in the third reflector layer 44 allows the hologram of the first microstructure 16 to be seen when viewed from the front. The cutout 32 in the first reflector layer 14 makes it possible to recognize the hologram of the third microstructure 42 when viewed from behind. Thus, in Fig. 6 shown construction of the security element 10 as a further authenticity feature, a hologram in the hologram can be recognized by the observer. If the first reflector layer 14 and the third reflector layer 44 are produced from different materials, then bimetallic effects can be generated in cooperation with the cutouts 32, which can be seen from the top and the back.

The method of manufacturing the security element 10 according to Fig. 6 is similar to the manufacturing methods described above. So only the differences are dealt with. After the application of the first structurable layer 22 with the first microstructure 16 provided therein and the application of the first reflector layer 14 with the cutouts 32 the third structurable layer 40 is applied to the first reflector layer 14. The third microstructure 42 is then introduced into the surface of the third layer 40 and the third reflector layer 44 with the cutouts 32 is arranged thereon. The cutouts 32 in the first reflector layer 14 and the third reflector layer 44 can be pressure cutouts or can be made by ablation. After the application of the first reflector layer 14 and the third reflector layer 44, the first reflector layer 14 and the third reflector layer 44 are ablated simultaneously by means of ablation, so that the recesses 18 produced therewith are in perfect register with one another.

In the Fig. 7 The embodiment of the security element 10 shown is similar to that in FIG Fig. 6 Embodiment of the security element 10 shown, so that only the differences are discussed. The security element 10 has analogous to that in FIG Fig. 6 The embodiment shown shows a first reflector layer 14 on the first layer 22 with the first microstructure 16 attached therein and the third layer 40 with the third microstructure 42 and the third reflector layer 44. In addition, the security element 10 has a carrier layer 46, which can be a transparent PET film, for example with a thickness of approximately 6 μm. The first layer 22 and the third layer 40 are applied to the carrier layer 46. This means that the first layer 22 and the third layer 40 are applied on different sides of the carrier layer 46. The respective microstructures 16 and 42 are provided on the respective layers 22, 40 in their surfaces facing away from the carrier layer 46. The reflector layers 14 and 44 are also applied to the side facing away from the carrier layer 46. The first reflector layer 14 therefore faces the front of the substrate 12, while the third reflector layer 44 faces the front of the substrate 12. Fixing the composite Carrier layer 46, first layer 22, first reflector layer 14, third layer 40 and third reflector layer 44 on the substrate 12 are achieved by the adhesive layer 34. The third reflector layer 44 is covered with the cover layer 38 in order to reduce contamination and damage.

The production method of the security element 10 according to Fig. 7 is as follows: First, the carrier layer 46 is provided, on one side of which the first layer 22 is provided. The first microstructure 16 is provided in its surface and the first reflector layer 14 is applied with an outline in the form of the first pattern. The third layer 40 is applied to the other side of the carrier layer 46. The third microstructure 42 is introduced into the surface of the third layer 40 and the third reflector layer 44 is applied. The cover layer 38 is now applied to the third reflector layer 44. The composite produced in this way is arranged on the substrate 12 with the aid of the adhesive layer 34 such that the recess 18 is arranged above the section 20. The recess 18 can be provided before or after the application to the substrate 12.

In the 8a and 8b The embodiment of the security element 10 shown is similar to the previously described embodiments. This security element 10 also has a laser radiation-sensitive layer 48, which is optionally arranged between the first layer 22 and the intermediate layer 36. The laser radiation-sensitive layer 48 is transparent before exposure to laser radiation of a certain intensity. After the laser radiation-sensitive layer 48 has been exposed to the laser radiation for ablation, the laser radiation-sensitive layer 48 is colored in the area where the laser radiation is exposed. The laser radiation-sensitive layer 48 can be laser-modifiable effect pigments or pigment-free laser-modifiable ones Contain marking substances. Examples of the laser radiation-sensitive layer 48 are in the publication WO 2010/072329 A1 described.

The production of the security element 10 according to the 8a and 8b is similar to the previously described procedures. First, the adhesive layer 34 and the intermediate film 36 are applied to the substrate 12. The laser radiation-sensitive layer 48 is then applied to the intermediate layer 36. The laser radiation-sensitive layer 48 is in this state, as in FIG Fig. 8a shown, transparent. The first layer 22 with the first microstructure 16 arranged thereon is applied to the laser radiation-sensitive layer 48. The first reflector layer 14 with the outline in the form of the first pattern is applied to the first layer 22. The recess 18 is provided in the second pattern by ablation in the first reflector layer 14. A change in color is induced in the laser radiation-sensitive layer 48 by the laser radiation during ablation. Since the ablation in the first reflector layer 14 and the color change in the laser radiation-sensitive layer 48 are effected by the same laser radiation, the colored area of the laser radiation-sensitive layer 48 is in perfect registration with the recess 18 in the second pattern. This means that the colored area of the laser radiation-sensitive layer 48 likewise has the second pattern.

Claims (18)

1. A method for manufacturing a security element (10), comprising the steps of:

   a) supplying a first structurable layer (22) on a substrate (12),

   b) producing a first microstructure (16) in a front side of the first structurable layer (22),

   c) applying a first reflector layer (14) to the first microstructure (16) in a first pattern, which is recognizable in plan view of the front side,
   wherein the first reflector layer (14) is applied by printing in the first pattern with a homogeneous thickness (d),
   characterized by the further step of:

   d) removing the first reflector layer (14) by means of laser ablation, wherein a gap (18) in the form of a second pattern, which is recognizable in plan view of the front side, is produced in the first reflector layer (14), and

   that the
   substrate (12) has a transparent or translucent portion (20) which is arranged below the first structurable layer (22), wherein the first reflector layer (14) is removed such that the second pattern is recognizable in transmission through the portion (20).
2. The method according to claim 1, characterized in that reflective pigments and/or metallic nanoparticles adapting to microstructures are printed.
3. The method according to claim 1 or 2, characterized in that the first microstructure is recognizable not only in plan view, but also in transmission.
4. The method according to any of claims 1 to 3, characterized in that the substrate is a paper, a foil, a paper-foil composite or a foil composite.
5. The method according to any of claims 1 to 4, characterized by the steps of:

   - producing a second microstructure (26) on a back side of the substrate (12), in particular below the portion (20), and

   - printing a second reflector layer (24) onto the second microstructure (26) in a third pattern, which is recognizable in plan view of the back side,

   wherein in step d) the second reflector layer (24) is simultaneously removed, in particular by the laser radiation being guided through the portion (20) during the laser ablation.
6. The method according to claim 5, characterized in that a second structurable layer (28) is applied and the second microstructure (26) is produced in the second structurable layer, preferably by embossing.
7. The method according to claim 5 or 6, characterized in that the first reflector layer (14) and/or the second reflector layer (24) are/ is applied in such a manner that the first reflector layer (14) in the first pattern and/or the second reflector layer (24) in the third pattern have/ has at least one gap (32).
8. The method according to any of claims 5 to 7, characterized in that the second reflector layer (24) in reflection produces an optical impression that differs from the first reflector layer (14).
9. The method according to any of claims 3 to 8, characterized by the steps of

   - producing a third microstructure (42) on the front side of the substrate (12), in particular above the portion (20), and

   - printing a third reflector layer (44) onto the third microstructure (42) in a fourth pattern with a homogeneous thickness (d), said fourth pattern being recognizable in plan view of the front side,

   wherein in step d) the third reflector layer (44) is simultaneously removed and
   wherein the first reflector layer (14) and/or the third reflector layer (44) are/ is applied in such a manner that the first reflector layer (14) in the first pattern and/or the third reflector layer (44) in the fourth pattern have/ has at least one gap (32).
10. The method according to claim 9, characterized in that a third structurable layer (40) is applied and the third microstructure (42) is produced in this layer (40), preferably by embossing.
11. The method according to claim 10, characterized in that the first reflector layer (14) is arranged between the first microstructure (16) and the third microstructure (42).
12. The method according to claim 10, characterized in that a transparent carrier layer (46) is provided between the first microstructure (16) and the third microstructure (42).
13. The method according to any of the preceding claims, characterized in that a fourth reflector layer (30), which in reflection produces an optical impression that differs from the first reflector layer (14), is printed in certain regions over the first reflector layer (14) with a homogeneous thickness (d),
    wherein in step d), the fourth reflector layer (30) is simultaneously removed and wherein the first reflector layer (14) and/or the fourth reflector layer (30) are/ is printed in such a manner that the first reflector layer (14) in the first pattern and/or the fourth reflector layer (30) have/ has at least one gap (32).
14. The method according to any of the preceding claims, characterized in that a laser-radiation sensitive layer (48), which changes its color under the action of laser radiation, is applied, and is changed with respect to color by the laser ablation.
15. The method according to any of claims 1 to 4, characterized in that a further reflector layer (24, 30, 44) with a homogeneous thickness (d)
    is printed either in a further pattern onto a further, front- or backside microstructure (42, 26) or is printed in certain regions onto the first reflector layer (14) - in reflection producing an optical impression that differs from the first reflector layer (14),
    wherein in step d) the further reflector layer (24, 30, 44) is simultaneously removed by means of the laser ablation.
16. The method according to claim 15, characterized in that at least one of the reflector layers (14, 24, 30, 44) is printed in such a manner that it has a gap (32).
17. A security element comprising

    - at least a first structural layer (22) on a substrate (12),

    - a first microstructure (16) in a front side of the first structural layer (22) and

    - a first reflector layer (14) printed onto the first microstructure (16) with a homogeneous thickness (d),

    - wherein the first reflector layer (14) is printed in a first pattern, which is recognizable in plan view of the front side,

    characterized in that

    - the first reflector layer (14) has a gap (18) produced by means of laser ablation in the form of a second pattern, which is recognizable in plan view of the front side,

    - the substrate (12) has a transparent or translucent portion (20) arranged below the first structurable layer (22), and

    - the first reflector layer (14) is removed such that the second pattern is recognizable in transmission through the portion (20).
18. The security element according to claim 17: manufacturable with a method according to any of claims 2 to 16.

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