WO2019210994A1

WO2019210994A1 - Security element, data carrier and use

Info

Publication number: WO2019210994A1
Application number: PCT/EP2019/000130
Authority: WO
Inventors: Maik Rudolf Johann SCHERER; Raphael DEHMEL; Kai Herrmann SCHERER
Original assignee: Giesecke+Devrient Currency Technology Gmbh
Priority date: 2018-05-03
Filing date: 2019-04-24
Publication date: 2019-11-07
Also published as: EP3787906A1; CN111836727A; DE102018003603A1; CN111836727B

Abstract

The invention relates to a security element for securing a valuable document, a security document or a valuable object, with pre-determined regions which appear to the observer in a first visually recognisable colour in diffuse lighting, particularly during observation in daylight, and in a second visually recognisable colour in lighting with a spot light source, particularly during observation with the torch of a smart phone in a darkened room, and form markings in the form of patterns, characters or an encoding, which are not recognisable to the observer in diffuse lighting, particularly during observation in daylight, and can only be identified during illumination with a spot light source, particularly during observation with the torch of a smart phone in a darkened room, wherein the security element comprises a layer with a reflective microstructure and a semitransparent functional layer facing the observer, and the semitransparent functional layer is designed such that it comprises the first visually recognisable colour during obsesrvation in the incident light and the second visually recognisable colour during observation in the transmitted light.

Description

Security element, disk and usage

The invention relates to a security element and a

Security element comprising data carrier, in particular a

Value document, security document or a valuable item. The invention further relates to the use of the security element for securing a data carrier provided with a retroreflective structure, in particular a license plate, a traffic sign, a billboard, or safety clothing.

Securities and security documents, such as banknotes, valuables or ID documents, but also other valuables, such as

Branded articles are often provided with security elements for the purpose of security, which allow verification of the authenticity of the data carrier and at the same time serve as protection against unauthorized reproduction. The

Security elements may, for example, be in the form of a security thread embedded in a banknote, a patch applied to the banknote, e.g. a transfer element or a cover sheet suitable for covering an opening in the banknote, a security strip or else in the form of a feature area applied directly to a value document.

To play a special role in the authentication of authenticity

Security features that show viewing-angle-dependent visual effects, as they can not be reproduced even with state-of-the-art copiers. In the prior art it is known, for example, to represent objects by means of a reflecting microstructure, which objects when tilted and / or rotated with the security element Value document cause movement effects. For example, reference is made to WO 2015/078572 A1 and WO 2016/180522 A1. The reflective microstructure includes microreflectors formed in a pattern so as to produce a planar security element having a plurality of pixels, each having at least one microreflector (ie

at least one optically effective facet). The two-dimensional form of the security element defines a main plane. The micro-reflectors are oriented so that the object when tilting and / or turning the

Security element causes a movement effect, on the

Main level is related. Instead of a movement effect, the

Objects also show a tilting effect. From WO 2011/066990 A2 a three-dimensional appearing object is known, which appears to the viewer in front of or behind the main plane arched shape. When the security element is tilted, the position of the object relative to the main plane remains unchanged.

The invention has for its object to provide a security element with higher security against counterfeiting.

The object is achieved by the feature combinations defined in the independent claims. Further developments of the invention are

Subject of the dependent claims.

Summary of the invention

1. (First aspect of the invention) Security element for securing a value document, security document or a valuable object, with predetermined areas, the viewer in diffuse lighting, especially when viewed in daylight, in a first visually recognizable color appear and when lighting with a

point light source, in particular when viewed with the flashlight of a smartphone in a darkened room, appear in a second visually recognizable color and form markings in the form of patterns, characters or a coding that the viewer in diffuse lighting, especially when viewed in the Daylight, are not recognizable and are only in the illumination with a point light source, especially when viewed with the flashlight of a smartphone in a darkened room, recognizable, wherein the security element comprises a layer with a reflective microstructure and the viewer facing semitransparent functional layer and the semitransparent functional layer is such that it has the first visually recognizable color when viewed in reflected light and has the second visually recognizable color when viewed in transmitted light.

2. (Preferred embodiment) Security element according to clause 1, wherein the reflective microstructure in the form of a retroreflective structure with triangular or square cube corners, or in the form of a

Micro-glass beads based retroreflective structure is formed, wherein the reflective microstructure preferably with a

Metallization, more preferably provided with a reflective metal coating.

3. (Preferred Embodiment) A security element according to clause 1, wherein the mosaic reflective microstructure consists of a multiplicity of reflective mosaic elements characterized by the parameters size, contour, relief, reflectivity, and spatial orientation and are such that the markings in the form of patterns, signs or an encoding while tilting the Security elements have a dynamic motion effect by different groups of mosaic elements with different characteristic parameters incident light in different

Reflect areas of space.

4. (Preferred embodiment) A security element according to one of the clauses 1 to 3, wherein the layer is present with a reflective microstructure in the form of a metallized embossing lacquer layer.

5. (Preferred Embodiment) A security element according to any one of clauses 1 to 4, wherein the markings are formed in the form of patterns, characters or a coding by recesses in an opaque layer disposed between the semitransparent functional layer and the layer with the retroreflective structures in which the opaque layer is in particular a metallization or a colored layer.

6. (Preferred Embodiment) A security element according to clause 5 with reference to clause 3, wherein the recesses in the opaque layer form first markings in the form of patterns, characters or an encoding and the reflective microstructure in the form of a mosaic of a plurality of reflective mosaic elements second markers form in the form of patterns, characters or an encoding, the second

Markers preferably at least partially to the first

Markings are adjusted.

7. (Preferred embodiment) A security element according to one of the clauses 1 to 6, wherein the semitransparent functional layer has a multilayer construction with two semitransparent metallic layers and one comprising between the two semitransparent metallic layers arranged dielectric layer.

8. (Preferred embodiment) Security element according to clause 7, wherein the two semitransparent metallic layers are formed independently of a metal and the metal in each case from the group consisting of Al, Ag, Ni, Cr, Cu, Au, Si and an alloy of a or more of the aforementioned elements, and the dielectric layer is a Si0 ₂ layer, a ZnO layer, a ZnS layer, an AhCb layer, a TiO ₂ layer, a nitride layer, or oxynitride of one of the elements Si , Zn, Al or Ti or a MgF2 layer or, for example, technically available, nitrocellulose layer.

9. (Preferred Embodiment) A security element according to clause 7 or 8, wherein the two semitransparent metallic layers are independently selected from Al or Ag and the dielectric layer is a Si0 ₂ layer.

10. (Preferred embodiment) A security element according to one of the clauses 1 to 6, wherein the semi-transparent functional layer is obtainable by printing technology by means of an effect pigment composition.

11. (Preferred embodiment) Security element according to one of the clauses 1 to 6, wherein the semitransparent functional layer has a multilayer structure based on transparent layers only

Interference layers, wherein the multilayer structure

in particular on, preferably alternating, layers of Ti0 ₂ , A1 ₂ 0 ₃ or other dielectrics based. 12. (Preferred Embodiment) A security element according to one of the clauses 1 to 6, wherein the semitransparent functional layer is based on a plasmonic color filter and in particular is based on two-dimensional periodic nanostructures. Plasmonic color filters based on two-dimensionally periodic nanostructures are known, for example, from DE 102011 101 635 A1.

13. (Preferred embodiment) Security element according to one of the clauses 1 to 12, wherein the predetermined areas appear to the viewer in diffuse lighting, especially when viewed in daylight, gold and lighting with a point light source, especially when viewed with the flashlight of a smartphone in a darkened room, appear bluish.

14. (Preferred Embodiment) A security element according to any one of clauses 1 to 13, wherein the security element has the following structure:

- adhesive layer;

Layer with a reflective microstructure;

Optionally, an opaque layer with recesses in the form of patterns, characters or an encoding;

- semitransparent functional layer;

- Carrier film.

15. (Preferred Embodiment) A security element according to any one of clauses 1 to 13, wherein the security element has the following structure:

- adhesive layer;

Layer with a reflective microstructure;

- Carrier film;

- semitransparent functional layer; wherein either between the layer with the reflective microstructure and the carrier film or between the carrier film and the

semitransparent functional layer optionally with an opaque layer

Recesses in the form of patterns, characters or a coding is arranged.

16. (Preferred embodiment) A security element according to clause 14 or 15, wherein an embossing lacquer layer with an embossed relief is arranged between the carrier foil and the semitransparent functional layer, wherein the embossed relief is in particular a relief having micro- and / or nanostructures.

17. (Second aspect of the invention) disk, in particular a

Value document, security document or a valuable article comprising the security element according to one of the clauses 1 to 16.

18. (Third aspect of the invention) A security element for securing a data carrier provided with a retroreflective structure, wherein the security element has predetermined areas which appear to the observer in diffuse illumination, in particular when viewed in daylight, in a first visually recognizable color and in which Lighting with a point light source, in particular when viewed with the flashlight of a smartphone in a darkened room, appearing in a second visually recognizable color and forming markings in the form of patterns, characters or a coding which are for the

Viewers in diffuse lighting, especially when viewed in daylight, are not recognizable and only in the lighting with a point light source, especially when viewing with the

Flashlight of a smartphone in a darkened room, recognizable are, wherein the security element one for bonding the

Security element with the hedged, provided with a retroreflective structure disk suitable adhesive layer and a

Viewers facing facing semitransparent functional layer and the semitransparent functional layer is such that they are in the

Contemplation in reflected light has the first visually recognizable color and when viewed in transmitted light has the second visually recognizable color.

It is preferred that the retroreflective structure of the data carrier is based on a reflective microstructure, in particular in the form of a retroreflective structure with triangular or square cube corners, or in the form of a microglass-based retroreflective structure, the reflective microstructure preferably having a metallization preferably with a mirroring

Metal coating is provided.

19. (Preferred Embodiment) A security element according to clause 18, wherein the markings in the form of patterns, characters or a coding are formed by recesses in an opaque layer arranged between the semitransparent functional layer and the adhesive layer.

20. (Preferred embodiment) A security element according to one of the clauses 18 or 19, wherein the semitransparent functional layer has a

multilayer structure having two semitransparent metallic layers and a dielectric layer arranged between the two semitransparent metallic layers.

21. (Preferred embodiment) Security element according to clause 20, wherein the two semi-transparent metallic layers are independent are each formed of a metal and the metal is selected from the group consisting of Al, Ag, Ni, Cr, Cu, Au, Si and an alloy of one or more of the aforementioned elements, and the dielectric layer is a Si0 ₂ layer, a ZnO layer, a ZnS layer, an Al ₂ O ₃ layer, a TiO ₂ layer, a layer of a nitride or oxynitride of any of Si, Zn, Al or Ti, or a MgF ₂ layer or For example, technically available, nitrocellulose layer.

22. (Preferred Embodiment) A security element according to clause 20 or 21, wherein the two semitransparent metallic layers are independently selected from Al or Ag and the dielectric layer is a Si0 ₂ layer.

23. (Preferred embodiment) Security element according to one of the clauses 1 to 6, wherein the semitransparent functional layer is obtainable by printing technology by means of an effect pigment composition.

24. (Preferred embodiment) Security element according to one of the clauses 18 or 19, wherein the semitransparent functional layer has a

multilayer structure based on only consisting of transparent layers interference layers, the multilayer structure is based in particular on, preferably alternating, layers of Ti0 ₂ , A1 ₂ 0 ₃ or other dielectrics.

25. (Preferred embodiment) Security element according to one of clauses 18 or 19, wherein the semitransparent functional layer is on a

plasmonic color filter based and in particular based on two-dimensional periodic nanostructures. Plasmonic color filters on Two-dimensional periodic nanostructures are based, for example, from DE 10 2011 101 635 Al known.

26. (Preferred embodiment) A security element according to any one of clauses 18 to 25, wherein the predetermined areas appear to the viewer in diffuse lighting, especially when viewed in daylight, gold and when illuminated with a point light source, especially when viewed with the flashlight of a smartphone in a darkened room, appear bluish.

27. (Preferred embodiment) A security element according to any one of clauses 18 to 26, wherein the security element has the following structure:

- adhesive layer;

- semitransparent functional layer;

- Carrier film.

28. (Fourth Aspect of the Invention) Data carriers provided with a retroreflective structure, in particular a license plate or

License plate, a road sign or a road sign, a billboard or advertising space, or security clothing, comprising the

Security element according to one of the clauses 18 to 27.

29. (Fifth Aspect of the Invention) Use of the security element according to any one of clauses 18 to 27 for securing a data carrier provided with a retroreflective structure, in particular a license plate, a traffic panel Road sign, a billboard or advertising space, or

Safety clothing.

Detailed description of the invention

An observation in reflected light in the sense of this invention is a lighting of the respective object from one side and a viewing of the object from the same side.

A reflection in transmitted light is in the sense of this invention

Illumination of the respective object from one side and one

Viewing the object from the opposite side. Diffuse lighting refers to diffuse light, which illuminates the scene evenly and with little or no shadow. Diffused light is produced by areal light sources.

In accordance with the present invention, attractive security features are provided that are useful in changing viewing in diffused lighting, particularly when viewed in daylight, on the one hand, and in illumination with a point light source, especially when viewed with a smartphone's flashlight

darkened room, on the other hand, an interesting color change

have, e.g. a change in color from gold in diffuse lighting to blue in lighting with a point light source. The same appearance as when viewed with a punctiform

Light source, especially when viewed with the flashlight of a smartphone in a darkened room, offers the viewer Incidentally, when viewing a with a smartphone camera with the flash on photos taken.

According to a first variant, for the layer with a reflective microstructure, a reflective microstructure in the form of a mosaic of a multiplicity of reflecting mosaic elements, characterized by the parameters size, outline shape, relief shape, reflectivity and spatial orientation, can be used, such that the Markers in the form of patterns, characters or coding when tilting the security element have a dynamic movement effect in that different groups of mosaic elements with different characteristic parameters reflect incident light into different spatial areas. The mosaic elements preferably have a lateral dimension of less than 30 pm and below the resolution limit of the eye. It is preferred that

Markings in the form of patterns, characters or a coding are formed as a motif in the form of an embossed structure in an embossing lacquer layer, wherein the embossing structure embossed embossed elements with surfaces

has different orientation. The embossing structure here consists of a reflective microstructure in the form of a mosaic of a multiplicity of reflecting mosaic elements, which are characterized by the parameters size, outline shape, relief shape, reflectivity and spatial orientation. Reflective microstructures for displaying objects that tilt and / or rotate with the

Security element provided value document motion effects

are known in the art, see e.g. the documents WO 2015/078572 A1, WO 2016/180522 A1 and WO 2011/066990 A2. The reflective microstructure may preferably be a planar

Create security element with a variety of pixels, respectively at least one reflective mosaic element, ie at least one optically effective facet comprise. The planar shape of the security element defines a main plane. The reflective mosaic elements are preferably oriented so that the object causes a movement effect when tilting and / or rotating the security element, which is related to the main plane. Instead of a movement effect, the objects can also show a tilting effect. From WO 2011/066990 A2 a three-dimensional appearing object is known, which appears to the viewer in front of or behind the main plane arched shape. When tilting the security element, the position of the object remains unchanged to the main level.

For the layer with a reflective microstructure, according to a second variant, a retroreflective structure can be used.

Retroreflective structures, e.g. the light of

Throwing back vehicle headlights in the direction of the driver to increase visibility are known in the art and can be used e.g. based on triangular or square cube corners or on micro glass beads, see e.g. US 4763985 A, US 20090300953 A1, WO 2014/117086 A1, US 6413615 B2 and US 4478769 A. Cube corner structures are based e.g. on embossed relief structures, which are mirrored with a reflective metal layer. The cube-corner structures may be present in particular with triangular or quadrilateral surfaces.

Conveniently, the relief structures are embossed in a plastic material or in a UV varnish.

The security element according to the invention is expediently based on a carrier film such as polyethylene terephthalate (PET), Polymethylmethacrylate (PMMA), polypropylene (PP), polyethylene (PE), polycarbonate (PC) or the like.

The layer having the retroreflective structure can

expediently in a layer thickness in a range from 10 μm to 200 μm, preferably in a range from 30 μm to 150 μm, and particularly preferably in a range from 40 μm to 150 μm. The height of the retroreflective structure, in particular of the triangular or quadrangular cube corners, is expediently at least 10 μm, preferably at least 30 μm, and expediently less than 200 μm, preferably less than 150 μm.

The semitransparent functional layer has on the one hand when viewed in incident light and on the other hand when viewed in transmitted light

different shades on. The two different shades are e.g. Complementary colors. Such a semitransparent functional layer is in particular a so-called Fabry-Perot thin-film element

Basis of a multilayer construction with two semitransparent metallic layers and a dielectric layer arranged between the two semitransparent metallic layers. Such a multi-layered structure, which appears gold-colored when viewed in reflected light and shows a blue hue when viewed in transmitted light, is e.g. from WO 2011/082761 Al known.

Suitable multi-layered structures with two semitransparent

have metallic layers and a dielectric layer disposed between the two semitransparent metallic layers

preferably the following physical nature: the two semitransparent metallic layers are preferably selected from Al or Ag; the dielectric layer is in particular a SiO ₂ layer or an MgF ₂ layer, preferably a SiO ₂ layer;

in the case where each of the two semitransparent metallic layers is based on Al, the respective preferred layer thickness is in a range of 5 nm to 20 nm, particularly preferably in a range of 10 nm to 14 nm; the Si0 ₂ dielectric layer preferably has a layer thickness in a range of 50 nm to 600 nm, more preferably in a range of 80 nm to 260 nm, and particularly preferably in a range of 210 nm to 260 nm, the ranges of 80 nm up to 100 nm and from 210 nm to 240 nm are especially preferred for providing a gold / blue color change;

in the case where each of the two semitransparent metallic layers is based on Ag, the respective preferred layer thickness is in a range from 15 nm to 30 nm, particularly preferably from 15 nm to 25 nm; the

Dielectric Si0 ₂ layer preferably has a layer thickness in a range of 50 nm to 600 nm, more preferably in a range of 80 nm to 260 nm, and particularly preferably in a range of 210 nm to 260 nm, wherein the ranges from 80 nm to 100 nm and from 210 nm to 240 nm are especially preferred for providing a gold / blue color change.

The above-mentioned multi-layered structures with two semi-transparent metallic layers and a dielectric layer arranged between the two semitransparent metallic layers may have a symmetrical three-layer structure in which both the material and the layer thickness of the two semitransparent metallic layers

Layers are identical. Alternatively, however, an asymmetric three-layer structure may be present, in which the material and / or the Layer thickness of the two semitransparent metallic layers are different, eg

a silver / dielectric / aluminum layer system, wherein the

Layer thicknesses of the silver layer and the aluminum layer are identical or different;

a silver / dielectric / silver layer system, wherein the

Layer thicknesses of the two silver layers are different;

- An aluminum / dielectric / aluminum layer system, wherein the layer thicknesses of the two aluminum layers are different.

The abovementioned multi-layered layer structures not only make it possible to produce a semitransparent functional layer which appears gold-colored when viewed in reflected light and shows a blue hue when viewed in transmitted light, but further color changes can be produced depending on the choice of the layer thickness, in particular of the dielectric layer, e.g.

Magenta in transmitted light, blue-green in transmitted light;

- in light turquoise, in transmitted light orange-yellow;

- in reflected light gold, in transmitted light blue-violet;

- in reflected light silver, in transmitted light violet.

A semitransparent functional layer, which when viewed in incident light on the one hand and when viewed in transmitted light on the other

has different shades, can further on a

Effect pigment composition based. Printed layers based on an effect pigment composition which, when viewed in reflected light, exhibit a different color than when viewed in transmitted light, in particular a gold / blue color change, a gold / violet color change, a green / gold / magenta color change, a Violet / green color change or one Silver / opaque color changes are described, for example, in WO 2011/064162 A2. The pigments preferably have a longest dimension of edge length from end-to-end in a range of 15 nm to 1000 nm and are based on a transition metal selected from the group consisting of Cu, Ag, Au, Zn, Cd, Ti, Cr, Mn, Fe, Co, Ni, Ru, Rh,

Pd, Os, Ir and Pt are chosen. The transition metal is preferably Ag. The aspect ratio (i.e., the ratio of the longest dimension from end-to-end in terms of thickness) is preferably at least 1.5, more preferably in a range of 1.5 to 300. The ratio of the binder to

Metal pigment is preferably below 10: 1, in particular below 5: 1. Depending on the choice of aspect ratio of the pigment, its longest end-to-end dimension, and adjustment of the pigment / binder ratio, the color can be seen in transmission and the color when viewed in reflection (eg, blue in Transmission and silver, gold, bronze, copper or violet in reflection, in addition also violet, magenta, pink, green or brown in transmission and different colors in reflection, which depend on the choice of pigment / binder ratio). Colors with

Gold / blue color change between reflection and transmission (in other words, between reflected light and transmitted light) are e.g. mentioned in Examples 1, 2 and 3 in Table 1 of WO 2011/064162 A2. Further, Example 4 shows a color with gold / violet color change, Example 5 a color with green-gold / magenta color change, Example 7 a color with violet / green color change and Example 8 a color with silver / opaque color change.

The security element according to the invention expediently has the following structure, wherein additional layers and films are conceivable: Adhesive layer suitable, for example, for applying the security element to a value document substrate, such as a banknote substrate;

Layer with a reflective microstructure;

- semitransparent functional layer;

- Carrier film.

According to a variant, the security element according to the invention may have the following structure, wherein additional layers and films are conceivable:

Adhesive layer, e.g. for applying the film to a

Value document substrate, such as a banknote substrate;

Layer with a reflective microstructure;

- Carrier film;

- semitransparent functional layer;

- Optionally, a protective lacquer or a protective film to protect the semi-transparent functional layer from harmful environmental influences;

wherein either between the layer with the reflective microstructure and the carrier film or between the carrier film and the

semitransparent functional layer optionally with an opaque layer

Recesses in the form of patterns, characters or a coding is arranged.

The opaque layer may in particular be a metallization obtainable, for example, by vapor deposition or a color layer obtainable, for example, by means of a printing process. The production of structured metallizations by means of a washing process is known in the art, see for example the document EP 1972462 Bl and the prior art cited therein. to Production of the color layer may further be platelet-shaped

Metal pigments, e.g. from the scriptures

WO 01/069823 A1, WO 2005/051675 A2 (see, for example, the description on page 11, line 10, to page 12, penultimate paragraph) and WO 2011/064162 A2. The ones described therein

platelet-shaped metal pigments have the advantage that they are a substrate with relief structure, in particular a relief with

Microstructures and / or nanostructures adapt so well that the difference to a conventional, available by vapor deposition metallization is almost unrecognizable. The simple, printing-technical production of the reflection layer makes it possible to dispense with complex process steps, such as printing the carrier with a soluble wash in the form of a desired recess within the reflection layer to be produced, generating a metallization by vapor deposition and washing the washing paint together with the above the washing paint applied metallization.

Between the carrier film and the semitransparent functional layer it is expediently possible to arrange an embossing lacquer layer with an embossed relief, wherein the embossed relief is in particular a relief having micro and / or nanostructures. The semitransparent functional layer adapts to the relief, so that when the security element is viewed in incident light, the observer receives additional optically variable information, e.g. in the form of patterns, signs or one

Coding, can perceive. As already mentioned above, optically variable security elements with a microstructure that are intended for

Securing banknotes are suitable, for example, from WO 2007/079851 Al and WO 2011/066991 A2 known. Furthermore, the security element according to the invention can have the markings in the form of a coding, for example in the form of a one-dimensional bar code or a two-dimensional code or QR code. Such a code can be easily scanned with the smartphone.

The security element according to the invention can be present in particular as a patch or label, as a strip or as a thread. In particular, the security element may be in the form of a transfer element formed on a temporary support.

Further embodiments and advantages of the invention are explained below with reference to the schematically greatly simplified figures, in the representation of a scale and proportion

Play has been omitted in order to increase the clarity.

Show it:

1 shows a security element according to the invention according to a first embodiment in a cross-sectional view;

FIG. 2 a cross-sectional view of a security element according to the invention in accordance with a second exemplary embodiment;

Figure 3 shows a security element according to the invention according to a third embodiment in plan view in the

Contemplation in daylight;

Figure 4 shows the security element according to the invention according to the third embodiment in plan view in the Looking through the pocket of a smartphone in a darkened room;

Figures 5 and 6 representations for explaining the operation of the

Subject of the invention;

FIG. 7 a cross-sectional view of a security element according to the invention in accordance with a fourth exemplary embodiment; Figure 8 shows the security element according to the invention according to the third embodiment in a cross-sectional view;

Figure 9 shows an embodiment of a retroreflective

Structure in plan view;

Figure 10 shows another embodiment of a

retroreflective structure in plan view; and

Figure 11 shows an embodiment of an inventive

Security element that is used to secure a

Vehicle license plate is suitable.

FIG. 1 shows a security element 1 according to the invention in a cross-sectional view according to a first exemplary embodiment. The reflective

Microstructure is formed in the example by a retroreflective structure. The security element 1 is based on a carrier foil 2, e.g. a polyethylene terephthalate (PET) film on the viewer

facing side provided with a semitransparent functional layer 3 is. The semitransparent functional layer 3 is obtainable by vapor deposition and has a multilayer construction with two

semitransparent Al layers and one between the two

semitransparent Al layers arranged SiC layer. The

semitransparent functional layer 3 appears golden when viewed in reflected light and shows a blue hue when viewed in transmitted light. The carrier film 2 is on the semi-transparent

Function layer 3 opposite side provided with an embossing lacquer layer 4. The embossing lacquer layer 4 is based e.g. on a UV varnish, in which the relief of the retroreflective structure is embossed. The relief of the

Embossing lacquer layer 4 is provided with a reflective metal coating 5, in FIG

Example, an aluminum metallization, provided, so as to form together with the relief of the embossing lacquer layer 4, the retroreflective structure. Adjacent to the specular metal coating 5 is an adhesive layer 6, e.g. for applying the

Security element 1 on a value document substrate, such as a

Banknote, is suitable.

FIG. 2 shows a security element 7 according to the invention in a cross-sectional view according to a second exemplary embodiment. The reflective microstructure is formed in the example by a retroreflective structure. The security element 7 is based on a carrier foil 8, e.g. a polyethylene terephthalate (PET) film, which forms an outer layer of the security element 7 in the present example. The carrier film 8 is at her

Inside provided with a semi-transparent functional layer 9. The semitransparent functional layer 9 is obtainable by vapor deposition and has a multilayer structure with two semitransparent Al layers and an SiC> 2 layer arranged between the two semitransparent Al layers. The semitransparent functional layer 9 appears in the Viewing in the incident light golden and shows when viewing in the

Transmitted light a blue shade. The semitransparent functional layer 9 is on the opposite side of the support film 8 with a

Embossing lacquer layer 10 provided. The embossing lacquer layer 10 is based on a UV lacquer in which the relief of the retroreflective structure is embossed. The relief of the embossing lacquer layer 10 is provided with a reflective metal coating 11, in the example an aluminum metallization, in order in this way together with the relief of the embossing lacquer layer 10

to form retroreflective structure. Adjacent to the specular metal coating 11 is an adhesive layer 12, e.g. for applying the retroreflective sheeting 7 to a value document substrate such as a banknote.

FIG. 3 shows a security element 13 according to the invention according to a third exemplary embodiment in plan view when viewed in daylight. The security element 13 appears to the viewer in the form of a

gold-colored, metallic surface.

4 shows the security element 13 according to the invention according to the third embodiment in plan view when illuminated with a point light source, in particular when viewed with the flashlight of a smartphone in a darkened room. The viewer takes the repeating characters "PL" and the

Line-shaped, square border in a bright, blue color against a dark, black background true.

FIG. 8 shows a cross-sectional view of the inventive security element 13 according to the third exemplary embodiment. The security element 13 is based on a carrier film 14, for example a polyethylene terephthalate (PET) - Film which forms an outer layer of the security element 13 in the present example. The carrier film 14 is provided on its inside with a semitransparent functional layer 15. The semitransparent functional layer 15 is obtainable by vapor deposition and has a multilayer structure with two semitransparent Al layers and an S1O2 layer arranged between the two semitransparent Al layers. The semitransparent functional layer 15 appears in the

Viewing in the incident light golden and shows when viewing in the

Transmitted light a blue shade. The semitransparent functional layer 15 is on the opposite side of the support film 14 with an optional, the semitransparent functional layer 15 protective transparent

Intermediate layer 16, in the example an intermediate coating provided. The optional intermediate layer 16 has opaque areas 17, e.g. are available by printing with a black ink. Alternatively, the opaque regions 17 may be provided by structured metallization. A structured metallization is e.g. through full-surface

Metallization and subsequent demetallization by means of a

Washing process or by full surface metallizing and

subsequent demetallization by means of a laser available. The opaque areas 17 represent the dark background shown in Fig. 4, which surrounds the characters "PL" and the square line border. "Furthermore, the security element 13 has an embossing lacquer layer 18. The embossing lacquer layer 18 is based on a UV lacquer into which The relief of the embossing lacquer layer 18 is provided with a reflective metal coating 19, in the example an aluminum metallization, in order in this way together with the relief of the

Embossing lacquer layer 18 to form the retroreflective structure. Adjacent to the reflective metal coating 19, an adhesive layer 20 is arranged, for example, for the application of the security element 13 to a

Value document substrate, e.g. a banknote, is suitable.

Figures 5 and 6 show illustrations for explaining the operation of the subject invention.

FIG. 5 shows a semitransparent functional layer 21, which is obtainable by vapor deposition, and a multilayer structure with two semitransparent Al layers and one between the two

having semitransparent Al layers arranged Si0 ₂ layer

(so-called Fabry-Perot thin-film structure). The semitransparent functional layer 21 appears golden when viewed in reflected light and shows a blue hue when viewed in transmitted light. Reference numeral 22 denotes the incident white light. As a result of the semi-transparent Gold Bla u color filter, the blue part of the

Color spectrum transmitted (see the arrow with the reference number 24, which denotes the transmitted blue light). The complementary, so to speak gold-colored part is reflected (see the arrow with the reference number 23, which refers to the reflected, so-called golden, light).

FIG. 6 shows the combination of those known from FIG.

semitransparent functional layer 21 together with retroreflectors 25, in the example the known from Figures 1, 2 and 8 microprisms, which are provided with a reflective metal coating. In the combination of color filter 21 together with the retroreflectors 25, the blue transmitted color portion 24 of the light spectrum is reflected by the retroreflectors 25 and transmitted a second time through the gold-blue color filter 21 (see the dashed arrows with the reference numerals 26 and 27, each denoting the blue light). The blue light 27 is for the Observers perceived, in the case of the embodiment of Figure 4 in the form of the luminous, blue letters "PL" and the line-shaped, square border.

The security element shown in Figures 1, 2 and 8 can

optionally supplemented by at least one further layer, e.g. Embossed structures such as e.g. Micromirror arrangements or

Has scattering structures or diffractive structures. This allows e.g. Realize security elements based on the known in the prior art micromirror technology that does not affect the color retroreflection at night. In the event of a vertical incidence of light at night, scattering structures can cause the gold-colored light component to be scattered.

FIG. 7 shows a security element 28 according to the invention in a cross-sectional view according to a fourth exemplary embodiment. The security element 28 is based on a carrier foil 29, e.g. a polyethylene terephthalate (PET) film, which on the side facing the viewer with a

Semitransparent functional layer 31 is provided. The semitransparent functional layer 31 is obtainable by vapor deposition and has a multilayer structure with two semitransparent Al layers and an Si0 ₂ layer arranged between the two semitransparent Al layers. The semitransparent functional layer 31 appears in the

Viewing in the incident light golden and shows when viewing in the

Transmitted light a blue shade. The semitransparent functional layer 31 is applied to the carrier film 29 by means of an embossing lacquer layer 30. The embossing lacquer layer 30 is based on a UV lacquer and has an embossed relief containing microstructures. The semitransparent

Functional layer adapts to the relief, so that the viewer in the Considering the security element in reflected light can perceive an additional, dependent on the viewing angle, optically variable information in the form of patterns, characters or a coding. The

semitransparent functional layer 31 is provided with an optional,

transparent protective layer 32, e.g. a protective lacquer, provided. The

Support film 29 has an embossing lacquer layer 33 on the side opposite the semitransparent functional layer 31. The embossing lacquer layer 33 is based on a UV lacquer in which the relief of the reflective

Microstructure, in the example a retroreflective structure is embossed. The relief of the embossing lacquer layer 33 is provided with a reflective metal coating 34, in the example an aluminum metallization, in order in this way together with the relief of the embossing lacquer layer 33

to form retroreflective structure. Adjacent to the specular metal coating 34 is an adhesive layer 35, e.g. for applying the retroreflective sheeting 28 to a value document substrate such as a banknote.

FIG. 9 shows an exemplary embodiment of a retroreflective structure in plan view. The retroreflectors are based on

Cube-corner structures or microprism structures in which the incident light is deflected successively at three mutually inclined boundary surfaces by about 45 ° and reflected back to the beam source. FIG. 9 shows the geometry of embossed retroreflectors

Triangular faces. The surface of the relief structure can with a

reflective metal layer is present in mirrored.

FIG. 10 shows a further exemplary embodiment of a

retroreflective structure in top view. Here is a geometry of embossed retroreflectors with square surfaces. FIGS. 1, 2, 6, 7 and 8 show exemplary embodiments in which the reflective microstructure is formed in the form of a retroreflective structure. Alternatively, the mosaic reflective microstructure could be formed from a plurality of reflective mosaic elements that are arranged such that the markings in the form of patterns, characters, or an encoding as the security element is tilted

dynamic motion effect by reflecting different groups of mosaic elements with different characteristic parameters incident light into different spatial areas.

For example, the relief 5 shown in FIG. 1, the relief 11 shown in FIG. 2, the relief 25 shown in FIG. 6, the relief 34 shown in FIG. 7 or the relief 19 shown in FIG in the figure 7 have reliefs 31, ie identical with the relief 31, different or at least partly identical.

FIG. 11 shows an exemplary embodiment of a device according to the invention

Security element that is used to secure one with a

retroreflective structure provided vehicle license plate is suitable. The security element 21 is based on a carrier foil 22, for example a polyethylene terephthalate (PET) film, which forms an outer layer of the security element 21 in the present example. The carrier film 22 is provided on its inside with a semi-transparent functional layer 23. The semitransparent functional layer 23 is obtainable by vapor deposition and has a multilayer structure with two semitransparent Al layers and an Si0 ₂ layer arranged between the two semitransparent Al layers. The semitransparent functional layer 23 appears gold-colored when viewed in reflected light and shows a blue hue when viewed in transmitted light. The semitransparent Functional layer 23 is on the opposite side of the support film 22 with an optional, the semi-transparent functional layer 23 protective transparent intermediate layer 24, in the example an intermediate coat, provided. Reference numeral 25 denotes opaque areas which are obtainable, for example, by printing with a black ink. Alternatively, the opaque regions 25 may be provided by patterned metallization. A structured metallization is eg by full surface metallization and subsequent demetallization by means of a washing process or by full surface metallization and

subsequent demetallization by means of a laser available. The opaque areas 25 represent e.g. Signs, patterns or a coding. Furthermore, the security element 21 has an adhesive layer 26.

With reference numeral 27 is a with the security element 21st

marked license plate or license plate of a motor vehicle. The mark 27 has a retroreflective structure 28 on the side opposite the security element 21.

Claims

Patent claims

1. security element for securing a value document,

Security document or a valuable item, with predetermined areas that the viewer in diffuse lighting, especially when viewed in daylight, appear in a first visually recognizable color and when lighting with a point light source, especially when viewed with the flashlight of a smartphone in a darkened room, appear in a second visually recognizable color and form markings in the form of patterns, characters or a coding, which are not visible to the viewer in diffuse lighting, especially when viewed in daylight, and only when illuminated with a point light source , especially when viewed with the flashlight of a smartphone in a darkened room, recognizable, wherein the security element comprises a layer having a reflective microstructure and a viewer facing the semi-transparent functional layer and the

semitransparent functional layer is such that they are in the

2. Security element according to claim 1, wherein the reflective

Microstructure is formed in the form of a retroreflective structure with triangular or square cube corners, or in the form of a micro-glass beads based retroreflective structure, wherein the

reflective microstructure is preferably provided with a metallization, more preferably with a reflective metal coating.

3. Security element according to claim 1, wherein the reflective

Microstructure in the form of a mosaic of a plurality of reflective mosaic elements, which are characterized by the parameters size, outline shape, relief shape, reflectivity and spatial orientation and are such that the markings in the form of patterns, characters or a coding when tilting the security element a dynamic motion effect by reflecting different groups of mosaic elements with different characteristic parameters incident light into different spatial areas.

4. A security element according to any one of claims 1 to 3, wherein the layer having a reflective microstructure in the form of a metallized

Embossing lacquer layer is present.

5. Security element according to one of claims 1 to 4, wherein the

Marks in the form of patterns, characters or a coding are formed by recesses in an opaque layer, which is between the semitransparent functional layer and the layer with the

retroreflective structures is arranged, wherein the opaque layer is in particular a metallization or a color layer.

6. The security element according to claim 5 when recited in claim 3, wherein the recesses in the opaque layer form first marks in the form of patterns, characters or an encoding and the reflective microstructure in the form of a mosaic of a plurality of reflective mosaic elements second marks in the form of patterns , Characters or an encoding, wherein the second markings are preferably at least partially adapted to the first markings.

7. The security element according to claim 1, wherein the semitransparent functional layer has a multilayer structure with two semitransparent metallic layers and a dielectric layer arranged between the two semitransparent metallic layers.

8. The security element according to claim 7, wherein the two semitransparent metallic layers are formed independently of one another from a metal and the metal is in each case from the group consisting of Al, Ag, Ni, Cr, Cu, Au, Si and an alloy of one or more of the above said element is selected and said dielectric layer is a Si0 ₂ layer, a ZnO layer, a ZnS layer, an AbCh layer, a Ti0 ₂ layer, a nitride layer or oxynitride of any one of Si, Zn, Al or Ti or a MgF ₂ layer or a, for example technically available, nitrocellulose layer.

9. Security element according to claim 7 or 8, wherein the two

semitransparent metallic layers are independently selected from Al or Ag and the dielectric layer is a Si0 ₂ layer.

10. Security element according to one of claims 1 to 6, wherein the semitransparent functional layer by means of a printing technology

Effect pigment composition is available.

11. A security element according to one of claims 1 to 6, wherein the semitransparent functional layer has a multilayer structure based on only consisting of transparent layers interference layers, wherein the multilayer structure in particular, preferably alternating, layers of Ti0 ₂ , A1 ₂ 0 ₃ or others Dielectrics based.

12. The security element according to claim 1, wherein the semitransparent functional layer is based on a plasmonic color filter and in particular is based on two-dimensional periodic nanostructures.

13. The security element according to one of claims 1 to 12, wherein the predetermined areas appear to the viewer in diffuse lighting, in particular when viewed in daylight, gold and lighting with a point light source, especially when viewed with the flashlight of a smartphone in a darkened room, appear bluish.

14. The security element according to one of claims 1 to 13, wherein the security element has the following structure:

- adhesive layer;

Layer with a reflective microstructure;

- semitransparent functional layer;

- Carrier film.

15. Security element according to one of claims 1 to 13, wherein the

Security element has the following structure:

- adhesive layer;

Layer with a reflective microstructure;

- Carrier film;

semitransparent functional layer optionally with an opaque layer

Recesses in the form of patterns, characters or a coding is arranged.

16. The security element according to claim 14 or 15, wherein between the carrier film and the semitransparent functional layer a

Embossing lacquer layer is arranged with an embossed relief, wherein the embossed relief is in particular a micro-and / or nanostructured relief.

17. A data carrier, in particular a value document, security document or a valuable article, comprising the security element according to one of claims 1 to 16.

18. Security element for securing a data carrier provided with a retroreflective structure, wherein the security element

has predetermined areas that the viewer at diffuser

Illumination, especially when viewed in daylight, appear in a first visually recognizable color and, when illuminated with a point light source, especially when viewed with the flashlight of a smartphone in a darkened room, appear in a second visually recognizable color and markings in shape form patterns, characters or a coding that are not recognizable to the viewer in diffused lighting, especially when viewed in daylight, and only when illuminated with a point light source, especially when viewed with the flashlight of a smartphone in a darkened room , are recognizable, wherein the Security element one for the gluing of the security element with the hedged, provided with a retroreflective structure

Data carrier suitable adhesive layer and the viewer facing semitransparent functional layer comprises and the semi-transparent functional layer is such that it has the first visually recognizable color when viewed in reflected light and has the second visually recognizable color when viewed in transmitted light.

19. The security element according to claim 18, wherein the markings are formed in the form of patterns, characters or a coding by recesses in an opaque layer which is between the semitransparent

Function layer and the adhesive layer is arranged.

20. The security element according to claim 18, wherein the semitransparent functional layer has a multilayer structure with two semitransparent metallic layers and a dielectric layer arranged between the two semitransparent metallic layers.

21. The security element according to claim 20, wherein the two

semitransparent metallic layers are formed independently of one another of a metal and the metal is selected in each case from the group consisting of Al, Ag, Ni, Cr, Cu, Au, Si and an alloy of one or more of the aforementioned elements and the dielectric layer is a Si0 ₂ layer, a ZnO layer, a ZnS layer, an Al ₂ O ₃ layer, a TiO ₂ layer, a layer of a nitride or oxynitride of any of Si, Zn, Al or Ti, or an MgF ₂ - Layer or one, eg

technically available, nitrocellulose layer is.

22. A security element according to claim 20 or 21, wherein the two semitransparent metallic layers are selected independently of each other of Al or Ag and the dielectric layer is a Si0 ₂ layer.

23. The security element according to one of claims 1 to 6, wherein the semitransparent functional layer by means of printing technology

Effect pigment composition is available.

24. The security element according to claim 18, wherein the semitransparent functional layer has a multilayer structure based on interference layers comprising only transparent layers, the multilayer structure being based in particular on, preferably alternating, layers of TiO ₂ Al ₂ O 3 or other dielectrics.

25. A security element according to any one of claims 18 or 19, wherein the semitransparent functional layer is based on a plasmonic color filter and in particular based on two-dimensional periodic nanostructures.

26. A security element according to any one of claims 18 to 25, wherein the predetermined areas appear to the viewer in diffuse lighting, especially when viewed in daylight, gold and when illuminated with a point light source, especially when viewed with the flashlight of a smartphone in a darkened room, appear bluish.

27. Security element according to one of claims 18 to 26, wherein the security element has the following structure:

- adhesive layer; Optionally, an opaque layer with recesses in the form of patterns, characters or an encoding;

- semitransparent functional layer;

- Carrier film.

28. Data carriers provided with a retroreflecting structure, in particular a license plate, a road sign, a billboard or advertising space, or

Safety clothing comprising the security element according to one of claims 18 to 27.

29. Use of the security element according to one of claims 18 to 27 for securing a data carrier provided with a retroreflective structure, in particular a license plate or

License plate, a road sign or a road sign, a billboard or advertising space, or safety clothing.