CN112888574A

CN112888574A - Security element and data carrier provided with a security element

Info

Publication number: CN112888574A
Application number: CN201980069287.4A
Authority: CN
Inventors: C.施密茨
Original assignee: Giesecke and Devrient GmbH
Current assignee: Giesecke and Devrient GmbH
Priority date: 2018-10-31
Filing date: 2019-10-21
Publication date: 2021-06-01
Anticipated expiration: 2039-10-21
Also published as: WO2020088791A1; EP3873749B1; DE102018008549A1; CN112888574B; EP3873749A1

Abstract

The invention relates to a security element for protecting a value document, comprising a carrier substrate provided with a first lamella element and a second lamella element, wherein the first lamella element is a tilting color-changing lamella element which gives the observer different color impressions at different viewing angles, and the second lamella element is a translucent lamella element which gives the observer different color impressions when viewed in reflected light and when viewed in transmitted light, wherein the first lamella element and the second lamella element are arranged on the carrier substrate in such a way that the second lamella element is formed in the form of a symbol, in the form of a pattern or in the form of a code, and the first lamella element appears as a background.

Description

Security element and data carrier provided with a security element

The invention relates to a security element for protecting a value document, comprising a carrier substrate provided with a tilting color-changing lamellar element. The invention also relates to a data carrier having such a security element.

Data carriers, such as value or certificate documents, or other valuable items, such as branded goods, are often provided with security elements in order to achieve protection (or protection against forgery), which enable verification of the authenticity of the data carrier and at the same time serve as protection against impermissible forgery. Security elements with viewing angle-dependent effects are of special interest in the protection of authenticity, since they cannot be reproduced even with the most modern copy machines. The security element is equipped with an optically variable element which gives the viewer a different image impression at different viewing angles and, for example, displays a different color or brightness impression and/or a different graphic pattern depending on the viewing angle.

It is known to use security elements with multi-layered lamellar elements, the color impression of which to the observer varies with the viewing angle (hereinafter referred to as tilting color change effect). In such thin-layer elements, the tilting discoloration effect is based on the viewing-angle-dependent interference effect caused by multiple reflections in the different sublayers of the element. The optical path length differences of the light reflected at the different layers depend on the one hand on the optical thickness of the dielectric spacer layer, which determines the spacing between the semitransparent absorber layer and the reflector layer, and on the other hand vary with the respective viewing angle. Since the optical path length difference is in the order of magnitude of the wavelength of visible light, the observer is given an angle-dependent color impression due to the extinction and the enhancement of the defined wavelength. By appropriate selection of the material and thickness of the dielectric spacer layer, a plurality of different tilting discoloration effects can be designed.

Furthermore, (see-through) security elements are known which have a multi-layered lamellar element, which when viewed in reflected light, i.e. by reflection, exhibits a first color and when viewed in transmitted light, i.e. by transmission, exhibits a second color. Document WO 2011/082761 a1 describes a lamellar element with a multilayer structure which appears golden when viewed in reflected 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.

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

The technical problem is solved according to the combination of features defined in the independent claims. Further developments of the invention are the subject matter of the dependent claims.

Disclosure of Invention

(first aspect of the invention) a security element for protecting a value document, comprising a carrier substrate provided with a first lamellar element and a second lamellar element, wherein the first lamellar element is a tilting-off lamellar element which gives the viewer a different color impression at different viewing angles and the second lamellar element is a translucent lamellar element which gives the viewer a different color impression when viewed in reflected light and when viewed in transmitted light, wherein the first lamellar element and the second lamellar element are arranged on the carrier substrate in such a way that the second lamellar element is formed in the form of a symbol, in the form of a pattern or in the form of a code and the first lamellar element appears as a background.

(preferred embodiment) the security element according to item 1, wherein the carrier substrate has, in addition to the first region formed by the first lamellar element and the second region formed by the second lamellar element, a third region which is either metallic or transparent and is formed in the form of a symbol, in the form of a pattern or in the form of a code, wherein the first lamellar element is present as a background.

(preferred embodiment) the security element according to

item

1 or 2, wherein the first tilting-discolouring lamellar elements which give the viewer different colour impressions at different viewing angles are (i) formed by means of effect pigments which produce an angle-dependent colour impression, or (ii) multilayered lamellar elements having a reflective layer, a dielectric spacer layer and a translucent absorber layer.

(preferred design) the security element according to one of items 1 to 3, wherein the translucent second lamellar element, which gives the viewer a different color impression when viewed in reflected light and when viewed in transmitted light, is (i) composed on the basis of an effect pigment composition, which shows a different color when viewed in reflected light than when viewed in transmitted light, or (ii) a multilayered lamellar element having two translucent metallic layers and a dielectric layer arranged between the two translucent metallic layers.

(preferred embodiment) the security element according to item 4, wherein the first tilting color changing lamellar element, which gives the viewer a different color impression when viewed at different viewing angles, is a multilayered lamellar element having a reflective layer, a dielectric spacer layer and a translucent absorber layer, and the second translucent lamellar element, which gives the viewer a different color impression when viewed in reflected light and when viewed in transmitted light, is a multilayered lamellar element having two translucent metal layers and a dielectric layer arranged between the two translucent metal layers, wherein the first tilting color changing lamellar element and the translucent second lamellar element are arranged on opposite sides of the carrier substrate.

(preferred design) the security element according to clause 5, wherein the security element has the following layer sequence:

-an optional protective lacquer layer;

-a first tilting color-changing lamellar element which gives the viewer a different color impression when viewed at different viewing angles;

-a first carrier substrate;

-a translucent second lamellar element imparting a different colour impression to the viewer when viewed in reflected light and when viewed in transmitted light;

-a second carrier substrate;

-an optional adhesive layer.

(preferred embodiment) the security element according to clause 4, wherein the first tilting color-changing lamellar elements which give the viewer a different color impression when viewed at different viewing angles are formed by means of effect pigments which produce an angle-dependent color impression, and the second translucent lamellar elements which give the viewer a different color impression when viewed in reflected light and when viewed in transmitted light are formed on the basis of an effect pigment composition which, when viewed in reflected light, exhibits a different color than when viewed in transmitted light, wherein the first tilting color-changing lamellar elements and the second translucent lamellar elements are arranged on the same side of the carrier substrate.

(preferred design) the security element according to clause 7, wherein the security element has the following layer sequence:

-an optional protective lacquer layer;

regions each having a first lamellar element which changes colour in a tilting manner and gives the observer a different colour impression when viewed at different viewing angles and/or a second lamellar element which is translucent and gives the observer a different colour impression when viewed in reflected light and in transmitted light;

-a carrier substrate;

-an optional adhesive layer.

(preferred design) the security element according to one of items 1 to 8, wherein the translucent second sheet element giving the viewer a different color impression when viewed in reflected light and when viewed in transmitted light appears golden when viewed in reflected light and has a blue hue when viewed in transmitted light.

(preferred design) the security element of one of clauses 1 to 9, wherein the security element is a security thread, a security strip or a patch or a label.

(preferred embodiment) the security element according to item 10, wherein the security element is a security thread, i.e. a window thread, having an area defined for embedding a valuable document substrate and a window area visible to a viewer, wherein the first lamellar element and the second lamellar element are particularly suitable for being arranged in the window area.

(preferred embodiment) the security element according to one of clauses 1 to 11, wherein the security element additionally has a color layer provided by printing technology, in particular based on platelet-shaped metallic pigments, in the region of a translucent second lamellar element which gives the viewer a different color impression when viewed in reflected light and when viewed in transmitted light.

(first aspect of the invention) a data carrier having a security element according to one of clauses 1 to 12.

(preferred embodiment) the data carrier according to item 13, wherein the security element is a patch or label or security strip and is arranged so as to overlap at least one transparent window region of the data carrier, wherein preferably at least a second lamellar element, particularly preferably both the first lamellar element and the second lamellar element, are arranged in the window region.

(preferred embodiment) the data carrier according to item 13, wherein the security element is a security thread having an area embedded inside the data carrier substrate and a window area visible to an observer, wherein the first and second lamellar elements are arranged in particular in the window area.

(preferred embodiment) the data carrier according to one of items 13 to 15, wherein the data carrier is a value document, such as a banknote, in particular a paper banknote.

Disclosure of Invention

According to the invention, the data carrier is illuminated from one side and viewed from the same side, viewed in reflected light. Thus, observation in reflected light occurs, for example, when the front side of the data carrier is illuminated and also observed.

According to the invention, the data carrier is illuminated from one side and viewed from the other side, in particular the opposite side, in transmitted light. Thus, observation in transmitted light occurs, for example, when the back side of the data carrier is illuminated and the front side of the data carrier is observed. Thus, light is transmitted through the data carrier.

Data carrier substrates of data carriers, for example, valuable document substrates, such as banknote substrates, in particular paper substrates or papery substrates, polymer substrates, paper/film/paper composite substrates or film/paper/film composite substrates. In the case of paper substrates, paper/film/paper composite substrates or film/paper/film composite substrates, the document of value or security paper provided with the window region can be produced, for example, by means of recesses penetrating into the paper layer. For example, a through-hole can be produced in the paper layer by punching or by laser irradiation. Alternatively, the paper layer can be made transparent in defined areas by means of a suitable liquid, for example by means of an aqueous sulfuric acid solution. In the case of a value document based on a transparent polymer substrate, the window region can be produced, for example, by means of congruent recesses in opaque printed layers arranged on the front side and the rear side of the polymer substrate.

According to the invention, it is provided in such a security element that a tilting color change, which produces an angle-dependent color impression, is combined with a translucent lamellar element, which has a color change when viewed in reflected light on the one hand and in transmitted light on the other hand, in such a way that the translucent lamellar element is formed in the form of a symbol, in the form of a pattern or in the form of a code and the first lamellar element appears as a background. By observing the security element in reflected light and in transmitted light while simultaneously changing the angle of observation, a convenient authenticity check is achieved. An additional, surprising optical effect for the observer can be achieved in that the translucent lamellar elements, which are present in the form of symbols, in the form of patterns or in the form of codes, have the same color when viewed in reflected light along a defined viewing angle as the tilting discoloration lamellar elements present as background.

The carrier substrate, for example a film, for example a polyethylene terephthalate film, can expediently first be provided with a (UV) embossing lacquer layer and then a translucent lamellar element and/or a tilting-discoloring lamellar element applied thereto. Advantageously, the (UV) embossing lacquer layer has an embossed relief structure, such as microstructures and/or nanostructures. In this way, optically variable structures, such as diffractive structures or hologram structures or micromirror devices, can be realized.

Translucent thin-layer elements which have a color change when viewed in reflected light on the one hand and transmitted light on the other hand are based, for example, on a multilayer structure having two translucent metal layers and a dielectric layer arranged between the two translucent metal layers. A multilayer structure that shows a gold color when viewed with reflected light and a blue color when viewed with transmitted light is known from, for example, patent document WO 2011/082761 a 1. A suitable multilayered structure with two semi-transparent metal layers and a dielectric layer arranged between the two semi-transparent metal layers preferably has the following specific properties:

the two semitransparent metallic layers are preferably selected from Al or Ag; dielectric layer, especially SiO₂Layer or MgF₂Layer, preferably SiO₂A layer;

in the case where each of the two translucent metal layers is based on Al, the respective preferred layer thickness is in the range from 5nm to 20nm, particularly preferably in the range from 10nm to 14 nm; dielectric SiO₂The layer preferably has a layer thickness in the range from 50nm to 450nm, further preferably in the range from 80nm to 260nm, particularly preferably in the range from 210nm to 260nm, wherein the ranges from 80nm to 100nm and from 210nm to 240nm are particularly preferred for producing a gold/blue color change;

in the case where each of the two translucent metal layers is based on Ag, the respective preferred layer thickness is in the range from 15nm to 30nm, particularly preferred from 15nm to 25 nm; dielectric SiO₂The layer preferably has a layer thickness in the range from 50nm to 450nm, further preferably in the range from 80nm to 260nm and particularly preferably in the range from 210nm to 260nm, wherein the ranges from 80nm to 100nm and from 210nm to 240nm are particularly preferred for producing a gold/blue color change.

The above-described multilayer structure having two semitransparent metal layers and a dielectric layer disposed between the two semitransparent metal layers may have a symmetrical three-layer structure in which the material and layer thickness of the two semitransparent metal layers are the same. But alternatively an asymmetrical three-layer structure is also possible, in which the materials and/or layer thicknesses of the two semitransparent metal layers are different, for example:

silver/dielectric/aluminum layer systems, in which the layer thicknesses of the silver layer and the aluminum layer are identical or different;

silver/dielectric/silver layer systems, in which the layer thicknesses of the two silver layers differ;

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

The above-described multilayer layer structure not only enables the production of a translucent functional layer which appears golden when viewed in reflected light and shows a blue hue when viewed in transmitted light, but also, depending on the choice of the layer thickness, in particular of the dielectric layer, can produce a further color change, for example,

-magenta when reflective and cyan when transmissive;

-greenish when reflected and yellow-orange when transmitted;

-gold when reflecting and blue-violet when transmitting;

silver when reflecting light and purple when transmitting light.

Translucent lamellar elements which have different hues when viewed in reflected light on the one hand and transmitted light on the other hand can also be based on effect pigment compositions. Printed layers based on effect pigment compositions which, when viewed in reflection, exhibit a different color than when viewed in transmission, 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 described, for example, in patent document WO2011/064162a 2. The pigment preferably has a longest dimension ("longest dimension of side length") ranging from 15nm to 1000nm from end to end and is 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. The transition metal is preferably Ag. The aspect ratio (i.e. the ratio of the longest dimension from end to end relative to the thickness) is preferably at least 1.5, especially in the range of 1.5 to 300. The ratio of binder to metal pigment is preferably less than 10: 1, in particular less than 5: 1. The choice of the aspect ratio of the pigment, its longest dimension end-to-end, and the choice of the pigment/binder ratio settings can set the color when the printed layer is viewed perspectively and the color when viewed in reflection (e.g., blue when viewed perspectively, silver, gold, bronze, copper, or purple when reflected; further purple, magenta, pink, green, or brown when viewed perspectively, and various colors when reflected, depending on the choice of pigment/binder ratio). Colors with a gold/blue color change between reflection and transmission (in other words, between reflected and transmitted light viewing) are mentioned for example in examples 1, 2 and 3 in table 1 of document WO2011/064162a 2. Further, embodiment 4 shows colors with gold/magenta color variation, embodiment 5 shows colors with green-gold/magenta color variation, embodiment 7 shows colors with magenta/green color variation, and embodiment 8 shows colors with silver/opaque color variation.

For example, a tilting color-changing lamellar element, which produces an angle-dependent color impression, can be produced in printing technology with the aid of effect pigments which produce an angle-dependent color impression. Suitable for this purpose are, for example, interference pigments, pearlescent pigments, metallic effect pigments or liquid crystal pigments.

The tilting color-changing lamellar element producing the angle-dependent color impression can also be a multilayered lamellar element, for example obtained by vapor deposition, having a reflective layer (for example Al), a dielectric spacer layer (for example SiO)₂) And a semi-transparent absorbing layer (or a partially light-transmissive layer, such as Cr). Such interference-carrying multilayer structures are known, for example, from documents WO 2005/038136 a1 and WO 2017/194189 a1 and are also referred to as thin-film layer interference layer structures or Color-shifting elements (Color-Shift-Element) because of their mode of action. The color impression varies with the viewing angle, for example from gold to green, from green to blue, from blue to magenta or from magenta to green. The resulting color range can be broadened by an additional printed, translucent color layer, for example, magenta-green by PVDLayer structure for tilting and changing color, coating "

Yellow 4 GN' constitutes a red-green tipping color changing structure. Green-blue tilting-discoloration layer structure obtained by PVD, coating "

Yellow 4 GN' constitutes a green-black color-changing structure.

The security element according to the invention can be designed, for example, as a laminate film, in particular in the form of a patch or label or in the form of a strip. The laminated film can then be applied to a value document substrate, for example a banknote, by means of an adhesive layer. In particular, windows or recesses in the valuable document substrate can be closed in this way. Furthermore, the security element according to the invention can be present as a security thread, in particular as a window thread, having an area provided for embedding a value document substrate and a window area visible to an observer, wherein the first lamellar element and the second lamellar element are particularly suitable for being arranged in the window area.

The security element according to the invention can additionally be provided with a magnetic and/or fluorescent security marking.

The security element according to the invention can additionally have, for example in the region of the translucent second lamellar element which gives the viewer a different color impression when viewed in reflected light and when viewed in transmitted light, a color layer provided by printing technology, in particular based on platelet-shaped metallic pigments. The color layer applied by printing technology can be present in particular in the form of symbols or in the form of patterns or codes. Furthermore, the color layer can be designed in particular such that it is not visible to the observer when viewed in reflected light, but is visible when viewed in transmitted light. The printed colours of platelet-shaped metal pigments can be based, for example, on the metal pigment compositions described in document WO 2005/051675 a2 (see, for example, the description therein on page 11, line 10 to page 12, penultimate paragraph). The pigment is based on a metal preferably selected from the group consisting of aluminum, stainless steel, nichrome, gold, silver, platinum and copper. The metal is particularly preferably aluminum, wherein the average particle diameter is preferably in the range from 2 to 50 μm, more preferably in the range from 5 to 15 μm, as measured by a Coulter LS130 laser diffraction particle analyzer. This printed color may provide a "silver" mirror layer. Further, the metallic pigment composition may be colored or dyed (e.g., yellow).

The invention also relates to a data carrier having a security element of the kind described above. The data carrier can be a value document, such as a banknote, in particular a paper currency, a polymer banknote or a film composite banknote, a stock certificate, a bond, a certificate, a voucher, a check, a high-quality admission ticket, or a certificate card, such as a credit card, a bank card, a cash card, a certificate, an identity card or a passport personal information page.

Further embodiments and advantages of the invention are explained below with reference to the drawings, in which scales and proportions are not represented in order to improve readability.

In the drawings:

figure 1 shows a schematic view of a banknote having a security element according to the present invention;

2-4 illustrate a security element according to the present invention according to one embodiment;

figure 5 shows a schematic view of a further banknote having a security element according to the present invention;

6-8 illustrate a security element according to the present invention according to further embodiments;

fig. 9 shows an embodiment for manufacturing a security element according to the invention;

fig. 10 shows a further embodiment for producing a security element according to the invention.

The invention will now be explained on the basis of an embodiment of a security element for banknotes. To this end, fig. 1 shows a schematic representation of a banknote 1 with two transparent window regions 3 (shown in dashed lines), the banknote 1 having a security element 4 according to the invention in the form of a patch and a security element 5 according to the invention in the form of a strip. The banknote 1 is based on a paper substrate 2, which paper substrate 2 has a through-opening in each of two regions 3. The through-recesses 3 are covered here on one side of the paper substrate 2 by

security elements

4 and 5 according to the invention, the

security elements

4 and 5 each being in the form of a laminate film. On the side of the paper substrate 2 opposite the respective security element, the paper substrate 2 may be provided with an additional transparent film, if necessary. The additional transparent film can cover the region of the through-openings in the paper or likewise have openings in the region of the through-openings in the paper. The banknote shown in fig. 1 has a denomination "20" in the lower left region, which is produced by printing.

Fig. 2 to 4 show a security element 5 according to the invention in the form of a strip according to one embodiment.

Fig. 2 shows the strip-shaped security element 5 of the banknote 1 when viewed in reflected light at a normal angle, i.e. at an angle of 90 ° to the plane of the paper substrate layer 2. Not only the symbol "TEXT" (reference numeral 7), but also the background 6 appears golden to the viewer. The viewer therefore sees the entire area of the security element with a uniform gold colour, so that the viewer cannot see the symbol "TEXT".

Fig. 3 shows the security element 5 in the form of a strip of the banknote 1 when viewed in reflected light at an angle of 45 ° to the plane of the paper substrate 2. The symbol "TEXT" (reference numeral 7) appears golden to the observer and the background 6 appears green to the observer. Thus, the symbol "TEXT" clearly stands out in gold in front of the green background when looking obliquely at the banknote 1 to the observer.

Fig. 4 shows the security element 5 in the form of a strip of the banknote 1 when viewed in transmitted light at an angle of 90 ° to the plane of the paper substrate layer 2. The symbol "TEXT" (reference numeral 7) appears blue to the viewer and the background 6 appears gold to the viewer. Thus, the symbol "TEXT" clearly stands out in blue in front of the gold background to the observer.

To this end, fig. 5 shows a schematic view of a further banknote 8, which is provided with a security element 9 according to the invention in the form of a security thread, specifically a window thread. The banknote 1 is based on a paper substrate 12 in which thread-shaped security elements 9 are partially embedded. In the region 11, the thread is completely embedded inside the paper. In the window area 10, the thread is not embedded into the interior of the paper and is therefore visible to the viewer both from the front side and from the back side. The banknote shown in fig. 5 has a denomination of "20" in the lower left region, which is produced by printing.

Fig. 6 to 8 show a linear security element 9 according to the invention according to one embodiment.

Figure 6 shows the security element 9 in the form of a thread of the banknote 8 when viewed in reflected light at a normal angle, i.e. at an angle of 90 to the plane of the paper substrate 12. The symbol "20" (reference numeral 14) appears in gold to the viewer. The background 13 appears magenta to the viewer. The symbol "TEXT" (reference numeral 15) appears to the observer as a silver color of metal.

Figure 7 shows the security element 9 in the form of a thread of the banknote 8 when viewed in reflected light at an angle of 45 to the plane of the paper substrate 12. The symbol "20" (reference numeral 14) appears gold to the viewer and the background 13 appears green to the viewer. The symbol "TEXT" (reference numeral 15) appears to the observer as a silver color of metal.

Figure 8 shows the security element 9 in the form of a thread of a banknote 8 when viewed in transmitted light at an angle of 90 to the plane of the paper substrate layer 2. The symbol "20" (reference numeral 14) appears blue to a viewer and the background 13 appears magenta to a viewer. The symbol "TEXT" (reference numeral 15) appears to the observer as a silver color of metal.

The regions shown in fig. 6 to 8 with the symbol "20" and the symbol "TEXT" are arranged in the window region 10 of the window line 9 contained in the banknote 8 (see fig. 5).

Fig. 9 shows an embodiment of the security element 5 according to the invention for producing a banknote 1 (see fig. 1).

According to fig. 9a), a polyethylene terephthalate film 16 is first prepared as a carrier substrate and then printed with a washing pigment (waskfarbe) 17 in the form of the symbol "TEXT" (see reference numeral 7 in fig. 2 to 4). The use of washing pigments in the manufacture of multilayer bodies is known to the person skilled in the art, see for example document EP 1972462 a 2.

According to fig. 9b) a reflective layer 18, in this case an Al layer, is then vapour-deposited. Before the Al layer is applied, a thin Cr layer can optionally be produced, which acts as an adhesion promoter.

According to FIG. 9c), a dielectric spacer layer 19, in this case SiO, is subsequently vapor deposited₂And (3) a layer.

According to fig. 9d), an absorber layer 20, in this case a Cr layer, is then vapor deposited.

Layers

18, 19 and 20 form a tilted color shifting thin layer element having a reflector/dielectric/absorber structure. The tilting color-changing lamellar elements appear to the observer gold at normal angles, i.e. at an angle of 90 ° to the plane of the substrate, and green at oblique angles, i.e. at an angle of 45 ° to the plane of the substrate.

Starting from fig. 9d), a demetallization step is carried out with the aid of a suitable washing solution. In this step, the washing pigment 17 is dissolved in the washing solution, so that the washing pigment 17 is removed together with the

further layers

18, 19 and 20 formed over the area of the washing pigment 17. The product obtained in the demetallization step is shown in fig. 9 e).

According to fig. 9f) an optional protective lacquer 21 is then applied.

Fig. 9g) to 9m) illustrate the production of translucent lamellar elements which, when viewed in reflected light, give the observer a different color impression than when viewed in transmitted light.

According to fig. 9g), the side of the carrier substrate 16 opposite the tilting color-changing lamellar element is printed with a washing colour 22 in a region outside the symbol "TEXT" (see reference numeral 7 in fig. 2 to 4).

According to fig. 9h) a semi-transparent metal layer 23, in this case an Al layer, is then vapour-deposited. Before the Al layer is applied, a thin Cr layer can optionally be produced, which acts as an adhesion promoter.

According to FIG. 9i), followed by vapor deposition of a dielectric layer 24, in this case SiO₂And (3) a layer.

According to fig. 9j), a semi-transparent metal layer 25, in this case an Al layer, is then vapour-deposited.

Layers

23, 24 and 25 form a translucent thin layer element which appears golden to an observer in reflected light and blue in transmitted light.

Starting from fig. 9j), a demetallization step is carried out with the aid of a suitable washing solution. In this step, the washing pigment 22 is dissolved in the washing solution, so that the washing pigment 22 is removed together with the

further layers

23, 24 and 25 formed over the area of the washing pigment 22. The product obtained in the demetallization step is shown in fig. 9 k).

According to fig. 9l), an adhesive layer 26 and a further polyethylene terephthalate film 27, i.e. a further carrier substrate, are then applied.

According to fig. 9m), a heat-seal lacquer layer 28 is finally applied, which is suitable for bonding the security element 5 to the value document substrate 2, in particular a paper substrate.

Fig. 10 shows an embodiment for producing a security element according to the invention, which is similar to the security element 9 of the banknote 8 (see fig. 5). For the sake of simplicity, only the layer structure having the translucent region (see symbol "20" in fig. 6 to 8) and the metallic luster region (see symbol "TEXT" in fig. 6 to 8) is shown in fig. 10.

According to fig. 10a), a multilayer body is first produced, wherein the polyethylene terephthalate film 16 is provided with a tilting discoloration thin-layer element having a reflective layer 18, a dielectric spacer layer 19 and an absorber layer 20 in regions other than the symbol "20" (see reference numeral 14 in fig. 6 to 8) and in regions other than the symbol "TEXT" (see reference numeral 15 in fig. 6 to 8). The tilting color-changing lamellar elements appear magenta to the viewer at normal angles, i.e. at an angle of 90 ° to the plane of the substrate, and green at oblique angles, i.e. at an angle of 45 ° to the plane of the substrate.

The multilayer body shown in fig. 10a) is additionally provided with a protective lacquer 21. The multilayer body shown in fig. 10a) can be manufactured in a similar manner as described above with respect to fig. 9a) to 9 f).

According to fig. 10a), the side of the polyethylene terephthalate film 16 opposite the tilting discoloring lamellar element is provided with a translucent metal layer 29, in this case an Al layer.

According to fig. 10b), a washing colour 30 is then applied in the region of the symbol "20" (see reference numeral 14 in fig. 6 to 8).

According to fig. 10c),followed by vapor deposition of a dielectric layer 31, in this case SiO₂And (3) a layer.

According to fig. 10d), a semi-transparent metal layer 32, in this case an Al layer, is then vapour-deposited.

Layers

29, 31 and 32 form a translucent thin layer element which appears golden to an observer in reflected light and blue in transmitted light.

Starting from fig. 10d), a demetallization step is carried out by means of a suitable washing solution. In this step, the washing pigment 30 is dissolved in the washing solution, so that the washing pigment 30 is removed together with the

further layers

31 and 32 formed over the area of the washing pigment 30. The product obtained in the demetallization step is shown in fig. 10 e).

The area "a" shown in fig. 10e) is a rollover-discolored area, which the viewer sees magenta at an angle of 90 ° and green at an angle of 45 °. The region "B" is a translucent region, which is seen by the viewer as a gold color when light is reflected and a blue color when light is transmitted through. The region "C" is metallic silver to the viewer.

The region "a" constitutes the background 13 in fig. 6 to 8. The region "B" constitutes the symbol "20" (see reference numeral 14 in fig. 6 to 8). The region "C" constitutes the symbol "TEXT" (see reference numeral 15 in fig. 6 to 8).

According to fig. 10f), an adhesive layer 33 and a further polyethylene terephthalate film 34, i.e. a further carrier substrate, are then applied.

According to fig. 10g), a heat-sealing lacquer layer 35 is applied if necessary, which is suitable for bonding the security element 9 to the value document substrate 12, in particular a paper substrate. In the case of the banknote 8 shown in fig. 5, the security element is a security thread 9 which is provided with an additional layer of heat-seal lacquer on both the upper side and the rear side in order to ensure the desired adhesion within the paper.

A third embodiment for the manufacture of a security element according to the invention is based on the embodiment shown above in connection with fig. 10. The polyethylene terephthalate film 16 shown in fig. 10a) is not provided with a translucent metal layer 29 (in particular an Al layer) but is provided with a washing pigment 30 in a local area. Thus obtaining the result of FIG. 10b)The layer structure shown is similar but the Al layer 29 is omitted. Then, a semitransparent metal layer (especially an Al layer) is applied over the entire surface, and a dielectric layer (especially SiO) is applied over the entire surface₂Layer) and over the whole surface an additional translucent metal layer (in particular Al layer) are applied, which together form a translucent thin-layer element, which appears golden in reflected light and blue in transmitted light, for example, to the viewer. In the step of demetallization with a suitable cleaning solution, the cleaning pigments 30 are removed together with the further layer formed over the area of the cleaning pigments. The product obtained in the demetallization step corresponds to the structure shown in fig. 10e), in which the Al layer 29 has a recess in the region "C". The product thus obtained is therefore transparent in the region "C". Similarly to fig. 10f) and 10g), a film 34 and a heat-seal lacquer layer 35 can then be applied.

A fourth embodiment for the manufacture of a security element according to the invention is based on the embodiment shown above in connection with fig. 9. The film 27 of the layer structure shown in fig. 9l) can be provided first with a color layer or a metallic effect color (for example an Al pigment which, after printing, has the appearance of a uniform silver mirror layer), in particular in the form of a symbol, a pattern or a code, in the central region (i.e. in the region in which the layers 23 to 25 are arranged) before the application of the heat-seal lacquer layer 28. A layer of heat seal lacquer 28 is then applied as shown in figure 9 m). The (metallic-effect) color layer can be realized in particular in such a way that it cannot be seen in reflected light but only when viewed in transmitted light. That is to say that the translucent lamellar elements, i.e. the layers 23-25, appear blue in transmission, for example, and the printed (metallic effect) color layer is recognized by the observer in the form of a dark contrast with respect to blue.

A fifth embodiment for the manufacture of a security element according to the invention is based on the embodiment shown above in connection with fig. 10. The film 34 of the layer structure shown in fig. 10f) can be provided first with a color layer or a metallic effect color (for example an Al pigment which, after printing, has the appearance of a uniform silver mirror layer), in particular in the form of a symbol, in the form of a pattern or in the form of a code, for example in the region "B", before the application of the heat-seal lacquer layer 35. A layer 35 of heat seal lacquer is then applied as shown in fig. 10 g). The (metallic-effect) color layer can be realized in particular in such a way that it cannot be seen in reflected light but only when viewed in transmitted light. That is, the translucent lamellar elements (i.e., layers 29-31) appear blue, for example, in the region "B" in transmission, and the printed (metallic effect) color layer is recognized by the observer as a dark contrast with respect to blue.

Claims

1. A security element for protecting a value document, comprising a carrier substrate provided with a first lamina element and a second lamina element, wherein the first lamina element is a tilting color-changing lamina element which gives the observer a different color impression at different viewing angles and the second lamina element is a translucent lamina element which gives the observer a different color impression when viewed in reflected light and when viewed in transmitted light, wherein the first lamina element and the second lamina element are arranged on the carrier substrate in such a way that the second lamina element is formed in the form of a symbol, in the form of a pattern or in the form of a code and the first lamina element appears as a background.

2. A security element according to claim 1, wherein the carrier base layer has, in addition to a first region formed by the first lamellar element and a second region formed by the second lamellar element, a third region which is either metallic or transparent and is formed in the form of a symbol, in the form of a pattern or in the form of a code, wherein the first lamellar element appears as a background.

3. Security element according to claim 1 or 2, wherein the first tilting-discolouring lamellar elements which give the viewer different colour impressions at different viewing angles are (i) formed by means of effect pigments which produce an angle-dependent colour impression or (ii) multilayered lamellar elements having a reflective layer, a dielectric spacer layer and a translucent absorber layer.

4. The security element according to one of claims 1 to 3, wherein the translucent second lamellar elements which, when viewed in reflected light and when viewed in transmitted light, give the viewer a different colour impression are (i) composed on the basis of an effect pigment composition which, when viewed in reflected light, shows a different colour than when viewed in transmitted light, or (ii) multilayered lamellar elements having two translucent metal layers and a dielectric layer arranged between the two translucent metal layers.

5. The security element according to claim 4, wherein the tilting-discoloring first lamellar element which gives the viewer a different color impression when viewed at different viewing angles is a multilayered lamellar element having a reflective layer, a dielectric spacer layer and a translucent absorption layer, and the translucent second lamellar element which gives the viewer a different color impression when viewed in reflected light and when viewed in transmitted light is a multilayered lamellar element having two translucent metal layers and a dielectric layer arranged between the two translucent metal layers, wherein the tilting-discoloring first lamellar element and the translucent second lamellar element are arranged on opposite sides of the carrier substrate.

6. The security element according to claim 5, wherein the security element has the following layer sequence:

-an optional protective lacquer layer;

-a first carrier substrate;

-a second carrier substrate;

-an optional adhesive layer.

7. The security element according to claim 4, wherein the first tilting-discoloring lamellar elements which, when viewed at different viewing angles, give the viewer a different color impression are formed by means of effect pigments which produce an angle-dependent color impression, and the second translucent lamellar elements which, when viewed in reflected light and when viewed in transmitted light, give the viewer a different color impression are formed on the basis of an effect pigment composition which, when viewed in reflected light, exhibits a different color than when viewed in transmitted light, wherein the first tilting-discoloring lamellar elements and the second translucent lamellar elements are arranged on the same side of the carrier substrate.

8. The security element according to claim 7, wherein the security element has the following layer sequence:

-an optional protective lacquer layer;

-a carrier substrate;

-an optional adhesive layer.

9. The security element according to one of claims 1 to 8, wherein the translucent second lamellar elements, which give the viewer a different colour impression when viewed in reflected light and when viewed in transmitted light, appear golden when viewed in reflected light and have a blue hue when viewed in transmitted light.

10. A security element according to one of claims 1 to 9, wherein the security element is a security thread, a security strip or a patch or a label.

11. The security element according to claim 10, wherein the security element is a security thread, i.e. a window thread, having an area provided for embedding a valuable document substrate and a window area visible to an observer, wherein the first and second lamellar elements are particularly adapted to be arranged in the window area.

12. The security element according to one of claims 1 to 11, wherein the security element additionally has a color layer provided by printing technology, in particular based on platelet-shaped metallic pigments, in the region of a translucent second lamellar element which gives the viewer a different color impression when viewed in reflected light and when viewed in transmitted light.

13. A data carrier with a security element according to one of claims 1 to 12.

14. A data carrier according to claim 13, wherein the security element is a patch or label or security strip and is arranged so as to overlap at least one transparent window region of the data carrier, wherein preferably at least the second lamellar element, in particular preferably both the first lamellar element and the second lamellar element, are arranged in the window region.

15. A data carrier as claimed in claim 13, wherein the security element is a security thread having an area embedded in the interior of the data carrier substrate and a window area visible to a viewer, wherein the first lamina element and the second lamina element are arranged in particular in the window area.

16. The data carrier according to one of claims 13 to 15, wherein the data carrier is a value document, such as a banknote, in particular a paper banknote.