DE102018008147A1 - Security element and data carrier equipped with the security element - Google Patents

Abstract

The invention relates to a security element for securing documents of value, comprising, in order, a carrier substrate, an embossing lacquer layer, a Cr layer serving as an adhesion promoter layer, and a semi-transparent layer structure which conveys a different color impression to a viewer when viewed in incident light and when viewed in transmitted light .

Description

The invention relates to a security element for securing documents of value, comprising, in order, a carrier substrate, an embossing lacquer layer, a Cr layer serving as an adhesion promoter layer, and a semi-transparent layer structure which conveys a different color impression to a viewer when viewed in incident light and when viewed in transmitted light . The invention further relates to a data carrier with such a security element.

Data carriers, such as documents of value or identity documents, or other objects of value, such as branded articles, are often provided with security elements for security purposes, which allow the authenticity of the data carriers to be checked and which at the same time serve as protection against unauthorized reproduction. Security elements with viewing angle-dependent effects play a special role in ensuring authenticity, since these cannot be reproduced even with the most modern copying machines. The security elements are equipped with optically variable elements that convey a different image impression to the viewer from different viewing angles and, for example, show a different color or brightness impression and / or a different graphic motif depending on the viewing angle.

In this context, it is known to use security elements with multilayer thin-film elements, the color impression of which changes for the viewer with the viewing angle (hereinafter referred to as the color shift effect). The color shift effect in such thin-film elements is based on viewing angle-dependent interference effects due to multiple reflections in the different sub-layers of the element. The path difference of the light reflected from the different layers depends on the one hand on the optical thickness of a dielectric spacer layer, which defines the distance between a semi-transparent absorber layer and a reflection layer, and on the other hand varies with the respective viewing angle. Since the path difference is of the order of magnitude of the wavelength of visible light, an angle-dependent color impression results for the viewer due to the extinction and amplification of certain wavelengths. A suitable choice of material and thickness of the dielectric spacer layer enables a multitude of different color shift effects to be designed.

In addition, (see-through) security elements with multilayer thin-film elements are known which appear in a first color when viewed in incident light, ie in reflection, and appear in a second color when viewed in transmitted light, ie in transmission. The WO 2011/082761 A1 describes a thin-film element with a multi-layer structure that appears golden when viewed in incident light and blue when viewed in transmitted light. The multilayer structure is based on two semi-transparent mirror layers and a dielectric spacer layer arranged between the two mirror layers.

Proceeding from this, the object of the invention is to provide a security element of the type mentioned at the outset which is improved with regard to the production.

This object is achieved in accordance with the combinations of features defined in the independent claims. Developments of the invention are the subject of the dependent claims.

Summary of the invention

• 1. (First aspect of the invention) Security element for securing documents of value, comprising in the order a carrier substrate, an embossing lacquer layer, a Cr layer serving as an adhesion promoter layer and a semitransparent layer structure, which a viewer can observe when viewed in incident light and when viewed in transmitted light gives a different color impression.
• 2. (Preferred embodiment) security element according to clause 1, wherein the Cr layer serving as an adhesion promoter layer has a layer thickness in a range from 0.1 nm to 5 nm, preferably in a range from 0.2 nm to 4 nm.
• 3. (Preferred embodiment) security element according to one of clauses 1 or 2, the semi-transparent layer structure, which gives a viewer a different color impression when viewed in reflected light and when viewed in transmitted light, on two semi-transparent metallic layers and one between the two semi-transparent ones based on metallic layers arranged dielectric spacer layer.
• 4. (Preferred embodiment) security element according to clause 3, wherein the two semi-transparent metallic layers are formed independently of one another from a metal and the metal in each case from the group consisting of Al, Ag, Ni, Cr, Cu, Au and an alloy of one or more of the above-mentioned elements is selected and the dielectric layer is an SiO ₂ layer, a ZnO layer, an Al ₂ O ₃ layer, a TiO ₂ layer, a layer made of a nitride or oxynitride of one of the elements Si, Zn, Al or Ti or one MgF ₂ layer or a nitrocellulose layer, for example available by printing technology.
• 5. (Preferred embodiment) security element according to clause 4, the two semitransparent metallic layers being selected independently of one another from Al or Ag and the dielectric layer being an SiO ₂ layer.
• 6. (Preferred embodiment) security element according to one of the clauses 1 to 5, the security element appearing gold-colored when viewed in incident light and having a blue hue when viewed in transmitted light.
• 6. (Preferred embodiment) security element according to one of clauses 3 to 5, the sum of the layer thicknesses of the Cr layer and the semitransparent metallic layer adjacent to the Cr layer of the semitransparent layer structure of the layer thickness of the semitransparent metallic layer remote from the Cr layer of the semi-transparent layer structure.
• 7. (Preferred embodiment) security element according to one of clauses 1 to 6, the security element appearing gold-colored when viewed in incident light and having a blue hue when viewed in transmitted light.
• 8. (Preferred embodiment) security element according to one of clauses 1 to 7, the embossing lacquer layer being provided with an embossed relief structure and the relief structure in particular a diffractive structure, such as a hologram, a holographic grating image or a hologram-like diffraction structure, or an achromatic structure, such as a matt structure, or a micromirror arrangement or a blaze grating with a sawtooth-like groove profile or a Fresnel lens arrangement or a combination of two or more of the above-mentioned elements.
• 9. (Preferred embodiment) security element according to one of clauses 1 to 8, the semi-transparent layer structure, which conveys a different color impression to an observer when viewed in reflected light and when viewed in transmitted light, is formed in the form of patterns, characters or coding .
• 10. (Preferred embodiment) security element according to one of clauses 1 to 9, the security element being a security thread, a security strip or a patch or label.
• 11. (second aspect of the invention) data carrier with a security element according to one of clauses 1 to 10.
• 12. (Preferred embodiment) data carrier according to clause 11, the security element being arranged in a transparent window area of the data carrier.
• 13. (Preferred embodiment) data carrier according to clause 11 or 12, the data carrier being a document of value, such as a bank note, in particular a paper bank note, polymer bank note or composite film bank note, or an identification card.

Detailed description of the invention

For the purposes of this invention, viewing in incident light is illuminating the data carrier from one side and viewing the data carrier from the same side. An observation in incident light is thus, for example, when the front of the data carrier is illuminated and also viewed.

For the purposes of this invention, viewing in transmitted light is illuminating a data carrier from one side and viewing the data carrier from another side, in particular the opposite side. An observation in transmitted light is thus, for example, when the back of the data carrier is illuminated and the front of the data carrier is viewed. The light shines through the disk.

The data carrier substrate of the data carrier, e.g. a documentary value substrate, such as a banknote substrate, 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 windowed security document or security paper may e.g. in the case of a paper substrate, a paper / film / paper composite substrate or a film / paper / film composite substrate by means of a continuous recess within the paper layer (s). Alternatively, the paper layer can be coated with a suitable liquid, e.g. be made transparent in a certain area by means of an aqueous sulfuric acid solution. In the case of a value document based on a transparent polymer substrate, a window area e.g. by means of congruent cutouts in the opaque print layers applied to the front and back of the polymer substrate.

According to the invention, an embossing lacquer layer with an embossed relief structure is provided in a generic security element carrier substrate, such as a film, to be provided with a semi-transparent layer structure by means of a thin Cr layer as an adhesion promoter layer. The invention is based on the knowledge that the resistance and adhesion of a semitransparent layer structure arranged on a (UV) embossing lacquer layer is very low and is significantly increased by the presence of a thin Cr layer. For example, if a security element with the layer sequence "carrier substrate / (UV) embossing sack / Cr layer / Al layer / SiO ₂ layer / Al layer" is used, a markedly increased adhesion between the metallization of the semi-transparent layer structure and the (UV) embossing sack. The presence of the thin Cr layer, which serves as an adhesion promoter, is not recognizable to the naked eye, and therefore does not lead to a changed visual impression. The Cr layer serving as an adhesion promoter also improves the scratch resistance of the semi-transparent layer structure arranged thereon.

The semi-transparent layer structure is formed in particular by means of vapor deposition and is preferably an Al / SiO ₂ / Al layer structure or an Ag / SiO ₂ / Ag layer structure. Such a multi-layer structure, which appears golden when viewed in incident light and shows a blue hue when viewed in transmitted light, is from, for example WO 2011/082761 A1 known.

• - die beiden semitransparenten metallischen Schichten werden bevorzugt von Al oder Ag gewählt; die dielektrische Schicht ist insbesondere eine SiO₂-Schicht;
• - im Falle, dass jede der beiden semitransparenten metallischen Schichten auf Al 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 metallischen Schichten 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 with two semitransparent metallic layers and a dielectric layer arranged between the two semitransparent metallic layers typically have the following physical characteristics:

• - The two semi-transparent metallic layers are preferably chosen from Al or Ag; the dielectric layer is in particular an SiO ₂ layer;
• in the event that each of the two semitransparent metallic layers is based on Al, the respective preferred layer thickness is in a range from 5 nm to 20 nm, particularly preferably in a range from 10 nm to 14 nm; the dielectric SiO ₂ layer preferably has a layer thickness in a range from 50 nm to 450 nm, more preferably in a range from 80 nm to 260 nm and particularly preferably in a range from 210 nm to 260 nm, the ranges from 80 nm up to 100 nm and from 210 nm to 240 nm are particularly preferred for the provision of a gold / blue color change;
• - in the event that each of the two semi-transparent metallic layers is based on Ag, the respective preferred layer thickness is in a range from 15 nm to 25 nm; the dielectric SiO ₂ layer preferably has a layer thickness in a range from 50 nm to 450 nm, more preferably in a range from 80 nm to 260 nm and particularly preferably in a range from 210 nm to 260 nm, the ranges from 80 nm up to 100 nm and from 210 nm to 240 nm are particularly preferred for the provision of 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 above-mentioned multilayered layer structures not only enable the creation of a semi-transparent functional layer that appears gold-colored when viewed in incident light and shows a blue hue when viewed in transmitted light, but depending on the choice of layer thickness, in particular the dielectric layer, additional color changes can be generated, for example

• - Magenta in reflected light, blue-green in transmitted light;
• - Turquoise in incident light, orange-yellow in transmitted light;
• - Gold in incident light, blue-violet in transmitted light;
• - Silver in incident light, violet in transmitted light.

In the event that the semitransparent layer structure, which gives a viewer a different color impression when viewed in reflected light and when viewed in transmitted light, is based on two semitransparent metallic layers and a dielectric spacer layer arranged between the two semitransparent metallic layers, it is relative to the one obtained Optical properties are particularly advantageous if the sum of the layer thicknesses of the Cr layer and the semitransparent metallic layer of the semitransparent layer structure adjacent to the Cr layer corresponds to the layer thickness of the semitransparent metallic layer of the semitransparent layer structure remote from the Cr layer.

Furthermore, it would be conceivable to form the semitransparent layer structure by means of a single reflection layer obtainable by printing technology. Platelet-shaped metal pigments suitable for producing the reflection layer are from the WO 2013/186167 A2 , WO 2010/069823 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 known.

According to a special embodiment variant, the layer structure of the security element according to the invention has semitransparent areas which impart a different color impression to an observer when viewed in incident light and when viewed in transmitted light and which are formed in the form of patterns, characters or coding.

The security element according to the invention can in particular be designed as a so-called laminate film, in which the carrier or the carrier substrate is firmly anchored to the embossing lacquer layer. The laminate film, which is in particular in the form of a patch, a strip or a thread, can then be applied together with the carrier to a value document substrate. In particular, a window or a cutout in the value document substrate can be closed in this way.

The security element according to the invention can furthermore be designed as a so-called transfer film, in which the carrier or the carrier substrate is not firmly anchored to the embossing lacquer layer, but can be detached from the embossing lacquer layer. The transfer film, which is in particular in the form of a patch, a strip or a thread, can be applied to a value document substrate without the carrier substrate of the transfer film remaining on the value document substrate. Such a procedure is particularly suitable in the case that the document of value substrate to be equipped with the security element is a polymer substrate. In this way, the layer thickness in the product obtained is not too high.

• - eine optionale Farbannahmeschicht bzw. Druckannahmeschicht;
• - ein Trägersubstrat, z.B. Polyethylenterephthalat(PET)-Folie;
• - eine Prägelackschicht, die insbesondere eine diffraktive Struktur bildende Reliefstruktur und/oder eine Mikrospiegelanordnung bildende Reliefstruktur aufweist;
• - eine dünne, als Haftvermittler dienende Cr-Schicht;
• - einen semitransparenten Schichtaufbau, z.B. mit der Schichtenfolge Al/SiO₂/Al;
• - optional eine Primerschicht;
• - eine Klebschicht, z.B. eine Heißsiegelbeschichtung, die für das Verkleben des Sicherheitselements mit dem Datenträgersubstrat geeignet ist.

According to an advantageous variant, the security element according to the invention, in particular in the case of being present as a laminate film, has the following layers in the order:

• an optional ink acceptance layer or print acceptance layer;
• - a carrier substrate, for example polyethylene terephthalate (PET) film;
• an embossing lacquer layer which in particular has a relief structure forming a diffractive structure and / or a relief structure forming a micromirror arrangement;
• - a thin Cr layer serving as an adhesion promoter;
• a semitransparent layer structure, for example with the layer sequence Al / SiO ₂ / Al;
• - optionally a primer layer;
• - An adhesive layer, for example a heat seal coating, which is suitable for gluing the security element to the data carrier substrate.

• - eine Klebschicht, z.B. eine Heißsiegelbeschichtung, die für das Verkleben des Sicherheitselements mit dem Datenträgersubstrat geeignet ist;
• - eine optionale Primerschicht;
• - ein Trägersubstrat, z.B. Polyethylenterephthalat(PET)-Folie;
• - eine Prägelackschicht, die insbesondere eine diffraktive Struktur bildende Reliefstruktur und/oder eine Mikrospiegelanordnung bildende Reliefstruktur aufweist;
• - eine dünne, als Haftvermittler dienende Cr-Schicht;
• - einen semitransparenten Schichtaufbau, z.B. mit der Schichtenfolge Al/SiO₂/Al;
• - optional eine Primerschicht

According to a further advantageous variant, the security element according to the invention, in particular in the case of being present as a laminate film, has the following layers in the order:

• an adhesive layer, for example a heat seal coating, which is suitable for gluing the security element to the data carrier substrate;
• - an optional primer layer;
• - a carrier substrate, for example polyethylene terephthalate (PET) film;
• an embossing lacquer layer which in particular has a relief structure forming a diffractive structure and / or a relief structure forming a micromirror arrangement;
• - a thin Cr layer serving as an adhesion promoter;
• a semitransparent layer structure, for example with the layer sequence Al / SiO ₂ / Al;
• - optionally a primer layer

A UV-curing embossing lacquer can advantageously be used as the embossing lacquer, but a thermosetting embossing lacquer can also be used.

The thin Cr layer serving as an adhesion promoter advantageously has a layer thickness in a range from 0.1 nm to 5 nm. A layer thickness in a range from 0.2 nm to 4 nm is particularly preferred.

The security element according to the invention can additionally be equipped with magnetic and / or fluorescent security features.

The invention further relates to a data carrier with a security element of the type described above. The data carrier can be a document of value, such as a banknote, in particular a paper banknote, a polymer banknote or a composite film banknote, a share, a bond, a certificate or a voucher , a check, a high-quality admission ticket, but also an identification card such as a credit card, a bank card, a cash payment card, an authorization card, an identity card or a passport personalization page.

Further exemplary embodiments and advantages of the invention are explained below with reference to the figures, in the representation of which scale and proportions have been omitted in order to increase clarity.

• 1 eine schematische Darstellung einer Banknote mit einem erfindungsgemäßen Sicherheitselement;
• 2 ein erfindungsgemäßes Sicherheitselements gemäß einem ersten Ausführungsbeispiel in Querschnittansicht;
• 3 ein erfindungsgemäßes Sicherheitselements gemäß einem zweiten Ausführungsbeispiel in Querschnittansicht.

Show it:

• 1 a schematic representation of a banknote with a security element according to the invention;
• 2nd an inventive security element according to a first embodiment in cross-sectional view;
• 3rd an inventive security element according to a second embodiment in cross-sectional view.

The invention will now be explained using the example of security elements for banknotes. 1 shows a schematic representation of a banknote 1 with a transparent window area 3rd (shown in dashed lines) with a security element according to the invention 2nd is provided in the form of a patch. The banknote 1 is based on a paper substrate 4th that in the area 3rd has a continuous recess. The continuous recess is on at least one side of the paper substrate 4th covered by the security element according to the invention, which is present as a laminate film. On the side of the paper substrate opposite the security element, the paper substrate can optionally be provided with an additional transparent film. The additional transparent film can cover, for example, at least the area of the continuous recess. The in the 1 The banknote shown has the denomination "20" generated by printing in the lower left area.

The 2nd shows an inventive security element 2nd according to a first embodiment in cross-sectional view. The security element 2nd is in the letters with the letter " A “Designated areas semitransparent, the viewer perceives these areas when viewed in reflected light in the form of a gold-colored metallization, when viewed in transmitted light, the viewer perceives these areas in a blue hue. Im with the letter " B “Designated area is the security element 2nd opaque, metallic, both when viewed in reflected light and when viewed in transmitted light. In the areas outside the areas " A " and " B “Is the security element 2nd transparent.

Like in the 2nd shown is the security element 2nd in the window area of the paper substrate 4th the banknote 1 by means of an adhesive layer 5 , for example a heat seal lacquer, arranged. The carrier 6 in the form of a transparent plastic film, for example a PET film, has an embossing lacquer 7 on. The relief structure (ie the surface) of the embossing lacquer 7 contains, for example, a microstructure. Above the embossing lacquer 7 there is a thin Cr layer serving as an adhesion promoter layer 8th with a layer thickness of 1 nm. On the left and on the right side there are semitransparent thin-film elements that give a viewer a different color impression when viewed in reflected light and when viewed in transmitted light, in the present case these are thin-film elements, each of which are two semitransparent Mirror layers (with the reference numbers 9 and 11 ) and a dielectric spacer layer arranged between the two mirror layers 10th exhibit. Such a thin-film element, which appears golden in reflected light and blue in transmitted light, is in the WO 2011/082761 A1 described. The semi-transparent mirror layer 9 in the example is an Al layer with a layer thickness of 9 nm. The semi-transparent mirror layer 11 is also an Al layer and has a layer thickness of 10 nm. Compared to the layer thickness of the Al layer 11 is the layer thickness of the Al layer 9 thus by the layer thickness of the Cr layer serving as an adhesion promoter layer 8th decreased. The dielectric spacer 10th is an SiO ₂ layer in the example and has a layer thickness of 125 nm.

The opaque area 12th is formed in the example by an Al metallization with a comparatively high layer thickness.

The semi-transparent areas with the letter " A “Form when looking at the banknote 1 in plan view a background surrounding the number "20".

The opaque, reflective, through an Al layer 12th educated area " B “Generated when looking at the banknote 1 the number “2” in plan view.

In the areas outside the areas " A " and " B “Is the security element 2nd transparent, these transparent areas generate when viewing the banknote 1 the number "0" in plan view

The security element 2nd is covered by a protective lacquer on the top 13 protected.

Depending on the design of the micro or nanostructure of the embossing lacquer layer 7 shows the security element 2nd in the fields of " A " and or " B “Eg interesting three-dimensional arch effects.

The 3rd shows a further security element according to the invention 22 according to a second embodiment in cross-sectional view. The security element 22 is in the letters with the letter " A “Designated areas semitransparent, the viewer perceives these areas when viewed in reflected light in the form of a gold-colored metallization, when viewed in transmitted light, the viewer perceives these areas in a blue hue. Im with the letter " B “Designated area is the security element 22 opaque, metallic, both when viewed in incident light and when viewed in transmitted light. In the areas outside the areas " A " and " B “Is the security element 22 transparent.

Like in the 3rd shown is the security element 22 in the window area of the paper substrate 4th the banknote 1 by means of an adhesive layer 5 , for example a heat seal lacquer, arranged. Adjacent to the adhesive layer 5 there is a protective lacquer layer 13 in front.

On the left and on the right side there are semitransparent thin-film elements that give a viewer a different color impression when viewed in reflected light and when viewed in transmitted light, in the present case these are thin-film elements, each with two semitransparent mirror layers (with the reference numbers 9 and 11 ) and a dielectric spacer layer arranged between the two mirror layers 10th exhibit. Such a thin-film element, which appears golden in reflected light and blue in transmitted light, is in the WO 2011/082761 A1 described. The semi-transparent mirror layer 9 in the example is an Al layer with a layer thickness of 9 nm. The semi-transparent mirror layer 11 is also an Al layer and has a layer thickness of 10 nm. The dielectric spacer 10th in the example an SiO ₂ layer and has a layer thickness of 125 nm.

The opaque area 12th is formed in the example by an Al metallization with a comparatively high layer thickness.

The semi-transparent areas with the letter " A “Form when looking at the banknote 1 in plan view a background surrounding the number "20".

The opaque, reflective, through an Al layer 12th educated area " B “Generated when looking at the banknote 1 the number “2” in plan view.

In the areas outside the areas " A " and " B “Is the security element 22 transparent, these transparent areas generate when viewing the banknote 1 the number "0" in plan view.

The carrier 6 in the form of a transparent plastic film, for example a PET film, has an embossing lacquer 7 on. The relief structure (ie the surface) of the embossing lacquer 7 contains, for example, a microstructure. The embossing lacquer 7 follows a thin Cr layer serving as an adhesion promoter layer 8th with a layer thickness of 1 nm.

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• WO 2011/082761 A1 [0004, 0011, 0029, 0038]
• WO 2013/186167 A2 [0015]
• WO 2010/069823 A1 [0015]
• WO 2005/051675 A2 [0015]
• WO 2011/064162 A2 [0015]

Claims (13)

Security element for securing documents of value, comprising, in order, a carrier substrate, an embossing lacquer layer, a Cr layer serving as an adhesion promoter layer and a semi-transparent layer structure, which conveys a different color impression to an observer when viewed in incident light and when viewed in transmitted light. Security element after Claim 1 , wherein the Cr layer serving as an adhesion promoter layer has a layer thickness in a range from 0.1 nm to 5 nm, preferably in a range from 0.2 nm to 4 nm. Security element according to one of the Claims 1 or 2nd , wherein the semi-transparent layer structure, which gives a viewer a different color impression when viewed in reflected light and when viewed in transmitted light, is based on two semi-transparent metallic layers and a dielectric spacer layer arranged between the two semi-transparent metallic layers. Security element after Claim 3 , wherein the two semitransparent metallic layers are formed independently of one another from a metal and the metal is selected in each case from the group consisting of Al, Ag, Ni, Cr, Cu, Au and an alloy of one or more of the above-mentioned elements and the dielectric layer an SiO ₂ layer, a ZnO layer, an Al ₂ O ₃ layer, a TiO ₂ layer, a layer made of a nitride or oxynitride of one of the elements Si, Zn, Al or Ti or an MgF ₂ layer or one , is, for example, a nitrocellulose layer obtainable by printing. Security element after Claim 4 , wherein the two semitransparent metallic layers are selected independently of one another from Al or Ag and the dielectric layer is an SiO ₂ layer. Security element according to one of the Claims 3 to 5 , the sum of the layer thicknesses of the Cr layer and the semitransparent metallic layer of the semitransparent layer structure adjacent to the Cr layer corresponding to the layer thickness of the semitransparent metallic layer of the semitransparent layer structure remote from the Cr layer. Security element according to one of the Claims 1 to 6 , wherein the security element appears golden when viewed in incident light and has a blue hue when viewed in transmitted light. Security element according to one of the Claims 1 to 7 , wherein the embossing lacquer layer is provided with an embossed relief structure and the relief structure in particular a diffractive structure, such as a hologram, a holographic grating image or a hologram-like diffraction structure, or an achromatic structure, such as a matt structure, or a micromirror arrangement or a blaze grating with a sawtooth Furrow profile or a Fresnel lens arrangement or a combination of two or more of the above elements. Security element according to one of the Claims 1 to 8th , wherein the semi-transparent layer structure, which gives a viewer a different color impression when viewed in reflected light and when viewed in transmitted light, is formed in the form of patterns, characters or a coding. Security element according to one of the Claims 1 to 9 , wherein the security element is a security thread, a security strip or a patch or label. Data carrier with a security element according to one of the Claims 1 to 10th . Disk after Claim 11 , wherein the security element is arranged in a transparent window area of the data carrier. Disk after Claim 11 or 12th , wherein the data carrier is a document of value, such as a banknote, in particular a paper banknote, polymer banknote or composite film banknote, or an identification card.

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