EP3319812B1 - Security element and data carrier - Google Patents

Description

The invention relates to a security element for securing a value document or a security paper. The invention further relates to a data carrier, in particular a value document or a security paper, which is equipped with the security element.

Data carriers, in particular value documents or security papers, are usually provided with security elements for security purposes, which permit verification of the authenticity of the data carrier and at the same time serve as protection against unauthorized reproduction of the data carrier. As security elements come e.g. Foil security elements into consideration, which have a foil substrate or plastic substrate and are applied by means of an adhesive layer on the data carrier.

To increase the security against counterfeiting, it is known to combine such film security elements with window areas in the value documents. A window area may e.g. be formed by means of a continuous recess in a (paper) substrate of a value document. In the case of a value document based on a transparent polymer substrate, a window area may e.g. be created by means of congruent recesses in the applied on the front and back of the polymer substrate opaque print layers.

The WO 95/10420 A1 describes a document of value in which the carrier is provided with a window-like opening, which is closed with an at least partially transparent cover film, wherein the cover, in particular in the region of the window-like opening with additional security features, such as diffraction structures, can be provided.

The WO 2005/025891 A2 describes a data carrier with a foil security element, wherein both the foil security element and the data carrier have a breakthrough area; the aperture areas preferably overlap at least partially, and more preferably they are congruent. In a further variant, the perforation region in the data carrier is covered by another side facing away from the side of the data carrier carrying the film security element.

The WO 2010/000432 A1 describes a document of value with an opening which is closed on one side with a translucent film. To increase the security against counterfeiting, both the upper side and the lower side of the document of value are covered with a translucent coating, which is preferably made over the entire surface. Preferably, the coatings are each independently extruded or laminated.

The WO 2011/015622 A1 describes a document of value having an opening which is closed on one side with an at least partially translucent or transparent film, wherein on the opposite side of the film of the document of value in the region of the opening and substantially in the region of the film surface is a coating, wherein the coating within the Opening does not exist or essentially does not exist.

The WO 2014/108329 A1 describes a method for producing an endless paper web for the production of security and value documents. The paper web is first with a continuous Opening provided. Subsequently, register-accurate application of a film with applied to the paper web security features.

Patent document DE 10 2009 031386 A1 discloses features a) to h) apart from the characterizing features of item h).

Based on this, the object of the present invention is to provide a security element by means of which the protection of a data carrier equipped with the same against counterfeiting can be further increased. Another object is to provide a data carrier equipped with the security element.

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

Summary of the invention

1. 1. (First aspect of the invention) Security element for securing a value document or a security paper, wherein the security element has a layer structure with the following layer sequence:
   1. a) a first film substrate;
   2. b) a first embossing lacquer layer;
   3. c) a first semitransparent functional layer;
   4. d) a printing layer applied to the first semitransparent functional layer;
   5. e) an adhesive layer;
   6. f) a second semitransparent functional layer;
   7. g) a second embossing lacquer layer;
   8. h) optionally a second film substrate; in which
      • the viewing of the security element with respect to the first film substrate a) from the side opposite the layers b) to h) defines the viewing of the security element front side and the viewing of the security element with respect to the optional second film substrate h) from the side opposite the layers a) to g) defines the viewing of the security element back side;
      • the first semitransparent functional layer c) forms a first motif that can be recognized by the incident light when viewing the security element front side;
      • the semitransparent second functional layer f) forms a second motif that can be recognized when viewing the security element rear side in incident light;
      • the printed layer d) applied to the first semitransparent functional layer forms a hidden third motif that is invisible when viewing the front of the security element in reflected light and is obscured by the first semitransparent functional layer c) and when viewed from the back of the security element is not recognizable and is obscured by the second semitransparent functional layer f) and that can be seen when viewing the security element in transmitted light both from the front side and from the rear side.
   
   The printing layer d) applied to the first semitransparent functional layer can in particular be produced by a gravure printing, flexographic printing, screen printing or inkjet process, the gravure printing process being preferred.
2. 2. (Preferred embodiment) Security element according to paragraph 1, wherein the second film substrate h) is mandatory and the security element by gluing two separate security element parts by means of the adhesive layer e) is available, wherein the first security element part of the layers a) to d) and the second security element part comprises layers f) to h). Alternatively, this is the layers a) to g) In a first step, two separate security element parts are glued by means of the adhesive layer e), wherein the first security element part comprises the layers a) to d) and the second security element part comprises the layers f) to h), and in a second step the second film substrate h) is detached from the resulting layer structure (in this case the second film substrate h) is a so-called transfer film).
3. 3. (Preferred embodiment) A security element according to paragraph 1 or 2, wherein the second semitransparent functional layer f) is a semitransparent mirror layer, in particular a metal consisting of the group consisting of Al, Ag, Ni, Cr, Cu, Au and an alloy of a or more of the above elements is selected.
4. 4. (Preferred embodiment) Security element according to paragraph 3, wherein the second semitransparent functional layer f) is based on A1 or an A1 alloy.
5. 5. (Preferred embodiment) Security element according to one of the paragraphs 1 to 4, wherein the first semi-transparent functional layer c) on the other hand has different shades when viewed in reflected light on the one hand and when viewed in transmitted light.
6. 6. (Preferred embodiment) A security element according to paragraph 5, wherein the first semitransparent functional layer c) has a multilayer structure with two semitransparent mirror layers and a dielectric layer arranged between the two semitransparent mirror layers, which appears gold-colored in particular when viewed in reflected light and when viewed in transmitted light shows a blue hue.
7. 7. (Preferred Embodiment) A security element according to paragraph 6, wherein the two semitransparent mirror layers are each selected from A1 or Ag and the dielectric layer is an SiO ₂ layer.
8. 8. (Preferred embodiment) Security element according to paragraph 7, wherein each of the two semitransparent mirror layers is based on A1 and has a layer thickness in a range of 5 nm to 20 nm, preferably in a range of 10 nm to 14 nm, and the dielectric SiO ₂ Layer has a layer thickness in a range of 50 nm to 450 nm, preferably in a range of 80 nm to 260 nm, and more preferably in a range of 210 nm to 260 nm.
9. 9. (Preferred Embodiment) The security element according to paragraph 7, wherein each of the two semitransparent mirror layers is based on Ag and has a layer thickness in a range of 15 nm to 25 nm and the dielectric SiO ₂ layer has a layer thickness in a range of 50 nm to 450 nm, preferably in a range of 80 nm to 260 nm, and more preferably in a range of 210 nm to 260 nm.
10. 10. (Preferred embodiment) Security element according to paragraph 5, wherein the first semitransparent functional layer c) is based on a printable layer having an effect pigment composition.
11. 11. (Preferred embodiment) Security element according to one of paragraphs 1 to 10, wherein the first embossing lacquer layer b) and the first semi-transparent functional layer c) have a first optically variable structure, in particular a diffractive relief structure or hologram structure or a microoptical relief structure (in particular a micromirror arrangement), form and the second embossing lacquer layer g) and the second semitransparent functional layer f) form a second optically variable structure, in particular a diffractive relief structure or hologram structure or a micro-optical relief structure (in particular a micromirror arrangement), wherein the second optically variable Structure is chosen independently of the first optically variable structure.
12. 12. (Preferred embodiment) Security element according to paragraph 11, wherein the first embossing lacquer layer b) and the first semitransparent functional layer c) form a diffractive relief structure and the second embossing lacquer layer g) and the second semitransparent functional layer f) form a microoptical relief structure, or vice versa.
13. 13. (Preferred embodiment) A security element according to any one of paragraphs 1 to 12, wherein the layer structure in addition to the layers a), b), c), d), e), f) and g) and the optionally present layer h) a Adhesive layer i) arranged for bonding the security element to a value document or security paper via an optionally present primer layer, the adhesive layer i) in particular on the first film substrate a), on the optionally present second film substrate h) or in the case that Film substrate h) is not present, on the second embossing lacquer layer g) is arranged.
14. 14. (Preferred embodiment) Security element according to one of the paragraphs 1 to 13, wherein the hidden third motif is in the context of meaning with the first motif and / or the second motif.
15. 15. (Second aspect of the invention) Data carrier, in particular a value document or a security paper, which is equipped with the security element according to one of claims 1 to 14.
16. 16. (Preferred Embodiment) The data carrier according to paragraph 15, wherein the data carrier is based on a data carrier substrate with a window area and the security element is arranged in the window area of the data carrier substrate.

Detailed description of the invention

The value document mentioned in the present description can be a banknote, in particular a paper banknote, a polymer banknote or a film composite banknote, a share, a bond, a certificate, a coupon, a check, a high-quality admission ticket, but also an identity card such as a credit card, a bank card, a cash card, an entitlement card, an identity card, or a pass personalization page.

A reflection in incident light is, in the sense of this invention, an illumination of the security element from one side and a viewing of the security element from the same side. A reflection in reflected light is thus present, for example, when the front of the security element is illuminated and also viewed.

A reflection in the transmitted light is in the sense of this invention an illumination of a security element from one side and a view of the security element from another side, in particular the opposite side. A consideration in transmitted light is thus for example, when the back of the security element is illuminated and the front of the security element is viewed. The light thus shines through the security element.

The security element according to the invention can e.g. as a patch or label, as an (endless) strip or as an (endless) thread.

The data carrier substrate of the data carrier to be equipped with the security element according to the invention is in particular a paper substrate or a paper-like substrate, a polymer substrate, a paper / film / paper composite substrate or a film / paper / film composite substrate. A security document provided with a window portion may be used in the case of a paper substrate, a paper / foil / paper composite substrate, or a film / paper / foil composite substrate, e.g. be produced by means of a continuous recess within the paper layer (s). Alternatively, the paper layer may be coated by means of a suitable liquid, e.g. be made transparent by means of aqueous sulfuric acid solution in a certain range. In the case of a value document based on a transparent polymer substrate, a window area may e.g. be created by means of congruent recesses in the applied on the front and back of the polymer substrate opaque print layers.

A preferred security element comprises at least one semitransparent functional layer which, on the other hand, has different hues when viewed in incident light on the one hand and when viewed in transmitted light on the other hand. The two different shades are, for example, complementary colors. Such a semitransparent functional layer is based, for example, on a multilayer structure with two semitransparent mirror layers and a dielectric layer disposed between the two semitransparent mirror layers. Such a multi-layered structure, which appears golden when viewed in reflected light and shows a blue hue when viewed in transmitted light, is for example from the WO 2011/082761 A1 known.

• die beiden semitransparenten Spiegelschichten werden bevorzugt von A1 oder Ag gewählt; die dielektrische Schicht ist insbesondere eine SiO₂-Schicht;
• im Falle, dass jede der beiden semitransparenten Spiegelschichten auf A1 beruht, liegt die jeweilige bevorzugte Schichtdicke in einem Bereich von 5 nm bis 20 nm, insbesondere bevorzugt in einem Bereich von 10 nm bis 14 nm; die dielektrische SiO₂-Schicht hat vorzugsweise eine Schichtdicke in einem Bereich von 50 nm bis 450 nm, weiter bevorzugt in einem Bereich von 80 nm bis 260 nm und insbesondere bevorzugt in einem Bereich von 210 nm bis 260 nm, wobei die Bereiche von 80 nm bis 100 nm und von 210 nm bis 240 nm speziell für die Bereitstellung eines Gold/Blau-Farbwechsels besonders bevorzugt werden;
• im Falle, dass jede der beiden semitransparenten Spiegelschichten auf Ag beruht, liegt die jeweilige bevorzugte Schichtdicke in einem Bereich von 15 nm bis 25 nm; die dielektrische SiO₂-Schicht hat vorzugsweise eine Schichtdicke in einem Bereich von 50 nm bis 450 nm, weiter bevorzugt in einem Bereich von 80 nm bis 260 nm und insbesondere bevorzugt in einem Bereich von 210 nm bis 260 nm, wobei die Bereiche von 80 nm bis 100 nm und von 210 nm bis 240 nm speziell für die Bereitstellung eines Gold/Blau-Farbwechsels besonders bevorzugt werden.

Suitable multilayer structures having two semitransparent mirror layers and a dielectric layer arranged between the two semitransparent mirror layers preferably have the following physical properties:

• the two semitransparent mirror layers are preferably selected from A1 or Ag; the dielectric layer is in particular an SiO ₂ layer;
• in the case where each of the two semitransparent mirror 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 SiO ₂ dielectric layer preferably has a layer thickness in a range of 50 nm to 450 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 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 mirror layers is based on Ag, the respective preferred layer thickness is in a range of 15 nm to 25 nm; the SiO ₂ dielectric layer preferably has a layer thickness in a range of 50 nm to 450 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 of 80 nm to 100 nm and from 210 nm to 240 nm are especially preferred for providing a gold / blue color change.

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

The aforementioned multilayered layer structures not only enable the production of a semitransparent functional layer, which appears golden when viewed in reflected light and shows a blue hue when viewed in transmitted light, but depending on the choice of the layer thickness, in particular of the dielectric layer further color changes can be generated, eg

• magenta in reflected light, blue-green in transmitted light;
• in incident light turquoise, in transmitted light orange-yellow;
• in reflected light gold, in transmitted light blue-violet;
• in reflected light silver, in transmitted light violet.

On the other hand, a semitransparent functional layer which has different hues when viewed in incident light on the one hand and when viewed in transmitted light on the other hand, may be based on an effect pigment composition. Printed layers based on an effect pigment composition which, when viewed in incident light, show a different color than when viewed in transmitted light, in particular a gold / blue color change, a gold / violet color change, a green / gold / magenta color change, a Violet / green color change or a silver / opaque color change, are eg in the WO 2011/064162 A2 described.

In a preferred security element, the first motif recognizable when viewing the security element front side in the reflected light represents a hologram (ie the first embossing lacquer layer b) and the first semi-transparent functional layer c) form a diffractive relief structure or hologram structure, and this when viewing the security element Rear side recognizable in incident light second motif is based on a micro-optical relief structure, in particular a micromirror arrangement

(ie, the second embossing lacquer layer g) and the second semitransparent functional layer f) form a microoptical relief structure, in particular a micromirror arrangement). The production of a micro-optical relief structure is known in the art (see, for example, the WO 2014/060089 A2 ).

According to an alternative to the above preferred security element, the first motif which can be recognized by the incident light when viewed from the front of the security element is based on a microoptical relief structure, in particular a micromirror arrangement, and the second motif recognizable when viewed in front of the security element back represents a hologram.

According to a further alternative to the above two preferred security elements, both the first motif recognizable when viewing the security element front side in incident light and the second motif recognizable when viewed in the reflected light when viewing the security element backside each represent a hologram.

According to a further alternative to the above three preferred security elements, both the first motif recognizable when viewing the security element front side in incident light and the second motif recognizable by reflected light when viewing the security element back are respectively based on a microoptical relief structure, in particular a micromirror arrangement ,

In the security element according to the invention, the first motif, the second motif and the third motif independently of each other in the form of a Pattern or an image, in the form of characters or a string or in the form of an encoding.

According to the invention, it is provided that the printed layer d) applied to the first semitransparent functional layer forms a hidden third motif that is not recognizable when viewing the security element front side in incident light and is hidden by the first semitransparent functional layer c) Rear side of the security element is not recognizable in incident light and is covered by the second semitransparent functional layer f) and that can be seen when viewing the security element in transmitted light both from the front side and from the rear side. The third motif may e.g. by gravure printing, flexographic printing, screen printing or by an inkjet process, preferably by means of intaglio printing. The third motif may e.g. in the form of a character or a string, in the form of a coding, in the form of a pattern, a picture or a portrait.

Further exemplary embodiments and advantages of the invention are explained below with reference to the figures, in the representation of which a representation true to scale and proportion has been dispensed with in order to increase the clarity.

Figur 1

die Draufsicht auf ein Wertdokument mit einem Fensterbereich und einem oberhalb des Fensterbereichs angeordneten Sicherheitselement;

Figur 2

die Querschnittansicht des in der Figur 1 gezeigten Wertdokuments;

Figur 3

den Fensterbereich eines Wertdokuments gemäß einem Ausführungsbeispiel bei der Betrachtung der Vorderseite des Wertdokuments im Auflicht;

Figur 4

den Fensterbereich eines Wertdokuments gemäß dem Ausführungsbeispiel bei der Betrachtung der Rückseite des Wertdokuments im Auflicht;

Figur 5

den Fensterbereich eines Wertdokuments gemäß dem Ausführungsbeispiel bei der Betrachtung der Vorder- oder der Rückseite des Wertdokuments im Durchlicht;

Figuren 6 bis 9

ein Beispiel für die Herstellung eines erfindungsgemäßen Sicherheitselements;

Figur 9

ein Sicherheitselement gemäß einem Ausführungsbeispiel;

Figur 10

das Sicherheitselement der Figur 9, das zusätzlich eine Klebschicht aufweist.

Show it:

FIG. 1

the top view of a document of value with a window area and arranged above the window area security element;

FIG. 2

the cross-sectional view of the in the FIG. 1 shown value document;

FIG. 3

the window area of a value document according to an embodiment when viewing the front side of the value document in incident light;

FIG. 4

the window area of a value document according to the embodiment when viewing the back side of the value document in reflected light;

FIG. 5

the window area of a value document according to the embodiment when viewing the front or the back of the document of value in transmitted light;

FIGS. 6 to 9

an example of the production of a security element according to the invention;

FIG. 9

a security element according to an embodiment;

FIG. 10

the security element of FIG. 9 , which additionally has an adhesive layer.

FIG. 1 shows a document of value 1, in the present example a banknote, in plan view. The value document 1 is based on a paper substrate and has a window area 2 (shown in dashed lines). The window area 2 can, for example, by means of a continuous generated by punching Aperture can be obtained in the paper substrate. The value document 1 is provided on its front side with a security element 3, which covers the window area 2 of the value document 1 on one side.

FIG. 2 shows the value document 1 of FIG. 1 in cross-sectional view (along in the FIG. 1 shown line A-A ').

The value document 1 is based on a paper substrate 4, which has a breakthrough recess 2. The recess 2 was produced by stamping and is present in the paper substrate 4 when viewed in plan view in the form of a square with the dimensions 1cm x 1cm (the dimensions can be chosen arbitrarily, as well as the shape of the window or the recess). The value document 4 is provided on the front side with a film security element 3, which covers the breakthrough recess 2 on one side. The film security element 3 is fixed on the paper substrate 4 by means of a marginal adhesive layer (not shown in the figure).

FIG. 3 shows the window area 2 of the value document 1 according to an embodiment when viewing the front side in incident light. The viewer perceives a metallic hologram motif 5.

FIG. 4 shows the window area 2 of the value document 1 according to the embodiment when viewing the rear side in incident light. The viewer perceives the areas 6 and 7 in the form of a golden color. The area 6 forms the denomination of the banknote "50" and appears to the viewer as compared to the background 7 in the form of a deceptively real, three-dimensional curved surface.

FIG. 5 shows the window area 2 of the value document 1 when viewed in transmitted light, from the front or the back. The observer perceives the white area 8 in the form of a blue background in front of which the blackened characters 9 (which in the example represent the denomination "50" of the banknote) stand out clearly.

FIGS. 6 to 10 illustrate an example of the preparation of in the FIGS. 1 to 5 shown security element 3.

FIG. 6 shows the production of a first security element part, in which on a film substrate 10 (for example, a polyethylene terephthalate film) first an embossing lacquer layer 11 is applied. The embossing lacquer layer 11 may for example be based on a UV-curable lacquer which is printed on the film substrate 10, then provided with an embossed pattern and finally UV-crosslinked. Thereafter, a motif is formed on the embossing lacquer layer 11 by means of an Al / SiO ₂ / Al layer sequence (in the figure, reference numerals 12 and 14 each denote an Al layer, reference numeral 13 denotes an SiO ₂ layer).

The provision of in the FIG. 6 shown, by the layer sequence 12 to 14 formed motif can be done for example by means of a washing technique known in the art, in which the carrier film 10 and the embossing lacquer layer 11 applied thereto first with an activatable with suitable solvents ink ("wash") in the form of characters is printed, is successively provided with an aluminum layer, with a SiO ₂ layer and with another aluminum layer and finally the ink together with the directly above areas of the Al, SiO ₂ and Al layers by washing with a Liquid is removed to produce coating-free areas in the form of the characters. Suitable inks are for example in the WO 97/23357 described. Alternatively, in the FIG. 6 shown, formed by the layer sequence 12 to 14 motif but also by laser demetalization or by etching, optionally with the aid of any photoresist layers are generated. The use of photoresist coatings in the security element production is for example from EP 2 049 345 B1 known.

In the FIG. 6 the Al layer 12, the SiO ₂ layer 13 and the Al layer 14 together form a semitransparent functional layer 15 which, when viewed in reflected light, appears gold-colored and shows a blue hue when viewed in transmitted light. Such a multi-layered structure, which appears golden when viewed in reflected light and shows a blue hue when viewed in transmitted light, is for example from the WO 2011/082761 A1 known.

According to the FIG. 7 the semitransparent functional layer 15 is provided by gravure printing with a black print layer 16 forming the hidden motif.

The in the FIGS. 6 and 7 shown semitransparent functional layer 15 forms in the FIG. 4 shown motif. The observer perceives the semitransparent functional layer 15 metallically golden when viewing the security element 3 in reflected light through the layers 10 and 11 in the form of the regions 6 and 7. The area 6 forms the denomination of the banknote "50" and appears to the viewer as compared to the background 7 in the form of a deceptively real, three-dimensional curved surface. The three-dimensional impression can be generated thereby be provided that the embossing lacquer layer 11 with a micro-optical relief structure. The production of a micro-optical relief structure is known in the art (see, for example, the WO 2014/060089 A2 ).

FIG. 8 shows the production of a second security element part, in which on a film substrate 17 (eg, a polyethylene terephthalate film) first an embossing lacquer layer 18 is applied. The embossing lacquer layer 18 may, for example, be based on a UV-curing lacquer which is printed on the film substrate 17, then provided with an embossed pattern and finally UV-crosslinked. On the embossing lacquer layer 18, a motif is subsequently produced by means of a semitransparent Al layer 19. The exact generation of the motif can be effected, for example, by means of a washing process, by laser demetallization or by an etching process, as described above.

The in the FIG. 8 shown semitransparent functional layer 19 forms in the FIG. 3 shown hologram motif 5. The viewer perceives the semitransparent functional layer 19 when viewing the security element 3 in incident light through the layers 17 and 18 through shiny metallic shiny. The production of the hologram motif 5 is based on equipping the embossing lacquer layer 18 with a diffractive relief structure.

FIG. 9 shows the step of gluing in the FIG. 7 shown first security element part with the in the FIG. 8 As can be seen, the bonding of the two security element parts is carried out register-accurate, so that the print layer 16 forming the hidden motif on the one hand passes through the semitransparent functional layer 15 and on the other hand by the semitransparent functional layer 19 is obscured.

The hidden layer forming the print layer 16 takes the viewer in transmitted light, both from the front and from the back, in the form of in the FIG. 5 shown black sign 9 against blue background 8 true. The blue background 8 is based on the semitransparent functional layer 15, which appears gold-colored when viewed in reflected light and shows a blue hue when viewed in transmitted light (and which consists of the A1 layer 12, the SiO ₂ layer 13 and the Al Layer 14 is composed).

According to the FIG. 10 For example, the security element can be provided with an adhesive layer 22 for bonding to a value-added substrate or security paper substrate via an optional primer layer 21. FIG. 10 shows the case that the adhesive layer 22 is attached to the film substrate 17. Alternatively, the adhesive layer 22 could be attached to the film substrate 10 via an optional primer layer.

Furthermore, that is in the FIG. 10 shown film substrate 17 only optional, ie the film substrate 17 is not mandatory. The Indian FIG. 9 Layer structure shown, which consists of a first security element part according to the FIG. 7 and a second security element part according to FIG. 8 can also be obtained that the second-security element part according to the FIG. 8 is equipped with a removable film substrate 17. The detachable film substrate 17 may be of the type described in US Pat FIG. 9 be removed before the Adhesive layer 22 over an optionally present primer layer 21 applies.

The security element according to the FIG. 10 put that in the FIG. 2 When viewing the front side of the value document 1 in reflected light, the observer perceives the motif generated by the semitransparent functional layer 15 (see FIG FIG. 4 ). When viewing the back side of the value document 1 in incident light, the viewer perceives the motif generated by the semitransparent functional layer 19 (see FIG FIG. 3 ). When viewing the value document 1 in transmitted light, whether from the front or the back, the viewer perceives the hidden print information 16 (see FIG. 5 ).

Claims (16)

1. A security element for securing a value document or a security paper, wherein the security element has a layer structure with the following layer sequence:

   a) a first foil substrate;

   b) a fi rst embossi ng lacquer layer;

   c) a first semitransparent functional layer;

   d) a printed layer applied to the first semitransparent functional layer;

   e) an adhesive layer;

   f) a second semitransparent functional layer;

   g) a second embossi ng lacquer layer;

   h) a second foil substrate; wherein

   - the vi ewi ng of the security element with respect to the fi rst foil substrate a) from the side opposite the layers b) to h) defines the viewing of the security-element front side and the viewing of the security element with respect to the second foil substrate h) from the si de opposite the layers a) to g) defines the vi ewi ng of the security-el ement back side;

   - the first semitransparent functional layer c) forms a first motif that is recognizable when viewing the security-element front side in incident light;

   - the semitransparent second functional layer f) forms a second motif that is recognizable when viewing the security-element back side in incident light;
   characterized in that

   - the printed layer d) applied to the first semitransparent functional layer forms a hidden third motif that is not recognizable when viewi ng the security-element front side in incident light and is covered by the first semitransparent functional layer c) and that is not recognizable when viewing the security-element back side in incident light and is covered by the second semitransparent functional layer f) and that is recognizable when viewing the security element in transmitted light both from the front side and from the back side.
2. The security element according to claim 1, wherein the security element is obtainable by adhesively bonding two separate security element parts by means of the adhesive layer e), wherein the first security element part comprises the layers a) to d) and the second security element part comprises the layers f) to h), wherein after the adhesive bonding the second foil substrate h) is possibly detached from the obtained layer structure.
3. The security element according to claim 1 or 2, wherein the second semitransparent functional layer f) is a semitransparent mirror layer, in particular a metal selected from the group consisti ng of Al, Ag, Ni, Cr, Cu, A u and an alloy of one or several of the aforementioned elements.
4. The security element according to claim 3, wherein the second semitransparent functional layer f) is based on Al or an Al alloy.
5. The security element accordi ng to any of claims 1 to 4, wherein the first semitransparent functional layer c) when viewing in incident light on the one hand and when viewing in transmitted light on the other hand has different color tones.
6. The security element according to claim 5, wherein the first semitransparent functional layer c) has a multi layer structure with two semitransparent mirror layers and a dielectric layer arranged between the two semitransparent mirror layers, said dielectric layer appearing golden in particular when viewing in incident light and showing a blue color tone when viewing in transmitted light.
7. The security element according to claim 6, wherein the two semitransparent mirror layers are selected of Al orAg and the dielectric layer is a SiO₂ layer.
8. The security element according to claim 7, wherein each of the two semitransparent mirror layers is Al-based and has a layer thickness in a range of 5 nm to 20 nm, preferably in a range of 10 nm to 14 nm, and the SiO₂ dielectric layer has a layer thickness in a range of 50 nm to 450 nm, preferably in a range of 80 nm to 260 nm.
9. The security element according to claim 7, wherein each of the two semitransparent mirror layers is Ag-based and has a layer thickness in a range of 15 nm to 25 nm, and the SiO₂ dielectric layer has a layer thickness in a range of 50 nm to 450 nm, preferably in a range of 80 nm to 260 nm.
10. The security element according to claim 5, wherein the first semitransparent functional layer c) is based on a layer with an effect pigment composition obtainable by printing technology.
11. The security element accordi ng to any of clai ms 1 to 10, wherein the first embossi ng lacquer layer b) and the first semitransparent functional layer c) form a first optically variable structure, in particular a diffractive relief structure or a micro-optical relief structure, and the second embossing lacquer layer g) and the second semitransparent functional layer f) form a second optically variable structure, in particular a diffractive relief structure or a micro-optical relief structure, wherein the second optically variable structure is selected independently of the first optical ly variable structure.
12. The security element according to claim 11, wherein the first embossing lacquer layer b) and the first semitransparent functional layer c) form a diffractive relief structure and the second embossi ng lacquer layer g) and the second semitransparent functional layer f) form a micro-optical relief structure, or vice versa.
13. The security element accordi ng to any of claims 1 to 12, wherein the layer structure in addition to the layers a), b), c), d), e), f) g) and h) has an adhesive layer i) for adhesively bonding the security element with a value document or security paper.
14. The security element accordi ng to any of claims 1 to 13, wherein the hidden third motif is meaningfully related to the fi rst motif and/or the second motif.
15. A data carrier, in particular a value document or a security paper, which is equipped with the security element according to any of claims 1 to 14.
16. The data carrier according to claim 15, wherein the data carrier is based on a data carrier substrate with a window region and the security element is arranged in the window region of the data carrier substrate.

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