WO2017080641A1

WO2017080641A1 - Security element, method for producing same, and data carrier equipped with the security element

Info

Publication number: WO2017080641A1
Application number: PCT/EP2016/001843
Authority: WO
Inventors: Björn Teufel; Giselher Dorff
Original assignee: Giesecke & Devrient Gmbh
Priority date: 2015-11-10
Filing date: 2016-11-08
Publication date: 2017-05-18
Also published as: EP3374197A1; AU2016352335B2; EP3374197B1; MX2018005812A; AU2016352335A1; CN108349290B; CN108349290A; DE102015014505A1

Abstract

The invention relates to a security element for securing documents of value, comprising a transparent carrier substrate and a first semi-transparent function layer, which has a multi-layer structure having a first semi-transparent metal layer, a second semi-transparent metal layer, and a dielectric layer arranged between the first and the second semi-transparent metal layers, wherein the second semi-transparent metal layer at least partially has a layer thickness greater than the layer thickness of the first semi-transparent metal layer.

Description

Security element, method for producing the same and with the

Security element equipped disk

The invention relates to a security element, a method of manufacturing the same and a data carrier equipped with the security element, e.g. a value document such as a banknote.

Data carriers, such as security documents or other valuables, such as branded articles, are often provided with security elements for the purpose of security, which permit verification of the authenticity of the data carriers and at the same time serve as protection against unauthorized reproduction.

In this context, (see-through) security elements with multi-layered thin-film elements are known which, when viewed in incident light, i. in reflection, appear in a first color and when viewed in transmitted light, i. in transmission, appear in a second color. WO 2011/082761 Al describes a thin-film element with a multilayer structure, which appears gold-colored when viewed in reflected light and blue when viewed in transmitted light. The multilayer structure is based on two semitransparent mirror layers and a dielectric spacer layer arranged between the two mirror layers.

Proceeding from this, the object of the invention is to specify a security element of the type mentioned at the outset with a high level of protection against forgery and an attractive visual appearance and a production method therefor.

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

1. (First aspect of the invention) security element for securing value documents, comprising a transparent carrier substrate and a first semitransparent functional layer having a multilayer structure with a first semitransparent metallic layer, a second semitransparent metallic layer and one between the first and the second semitransparent metallic Layer disposed dielectric layer, wherein the second semitransparent metallic layer is present at least partially in a greater layer thickness than that of the first semitransparent metallic layer. Preferably, the layer thickness of the second semitransparent metallic layer is at least partially 1.25 to 3 times, more preferably 1.5 to 2 times, as high as the

Layer thickness of the first semitransparent metallic layer.

2. (Preferred embodiment) A security element according to paragraph 1, wherein both the first semitransparent metallic layer and the second semi-transparent metallic layer are based on the same metal.

3. (Preferred embodiment) Security element according to paragraph 1 or 2, wherein the security element in the sequence has the following layer structure:

transparent carrier substrate;

- first semitransparent metallic layer;

- dielectric layer;

second semitransparent metallic layer at least partially present in a greater layer thickness than the first semitransparent metallic layer;

or the security element has the following layer structure in order: transparent carrier substrate;

- dielectric layer;

- first semitransparent metallic layer.

The layer thickness of the second semitransparent metallic layer is preferably at least partially 1.25 to 3 times, particularly preferably 1.5 to 2 times, as high as the layer thickness of the first semitransparent metallic layer.

4. (Preferred embodiment) The security element according to paragraph 1, 2 or 3, wherein the second semitransparent metallic layer defines the front side of the semitransparent functional layer and the first semitransparent functional layer defines the back side of the semitransparent functional layer and the semitransparent functional layer

- When viewing the back in reflected light has a first, visually recognizable color;

when viewing the front side in incident light at the location where the second semitransparent metallic layer is present in a greater layer thickness than the first semi-transparent metallic layer, has a second visually recognizable color and otherwise has the first visually recognizable color;

- When viewing both the front in the transmitted light, as well as the back in the transmitted light has a third, visually recognizable color.

5. (Preferred embodiment) A security element according to paragraph 4, wherein the two semitransparent metallic layers of Al or Ag are selected and the dielectric layer is a SiO ₂ layer and the visually recognizable colors are preferably the following colors:

- the first visually recognizable color is gold; the second visually recognizable color is silver;

- the third visually recognizable color is blue.

6. (Preferred embodiment) A security element according to any one of paragraphs 1 to 5, wherein the first semitransparent functional layer with multilayer structure is such that the first semitransparent metallic layer and the dielectric layer are each present in a uniform layer thickness and the second semitransparent metallic layer in first regions has the same layer thickness as the first semitransparent metallic layer and in the second regions has a greater layer thickness than that of the first semitransparent metallic layer.

7. (Preferred embodiment) Security element according to paragraph 6, wherein the security element

- When looking at the back in the incident light appears golden;

- Looking at the front in the reflected light in the first areas of gold and appears in the second areas silver;

- When viewing both the front in the transmitted light, and the back in the transmitted light appears bluish.

8. (Preferred embodiment) A security element according to one of the paragraphs 1 to 7, wherein the transparent carrier substrate of the security element next to the first semitransparent functional layer still has a second, technically available by means of an effect pigment composition semitransparent functional layer, wherein the second semitransparent functional layer in the Viewing in reflected light, both from the back and from the front in the first, visually recognizable color appears and when viewed in transmitted light, both from the back and from the front in the third, visually recognizable color appears. 9. (Preferred embodiment) A security element according to paragraph 8, wherein the second semitransparent functional layer appears golden when viewed in reflected light, both from the back and from the front, and when viewed in transmitted light, both from the back and from the front, bluish appears.

10. (Preferred Embodiment) A security element according to paragraph 1, wherein the metal of the first semitransparent metallic layer and the metal of the second semitransparent metallic layer are different metals.

11. (Preferred embodiment) The security element according to paragraph 10, wherein the security element has the following layer structure in the following order:

transparent carrier substrate;

- first semitransparent metallic layer;

- dielectric layer;

or the security element has the following layer structure in order:

transparent carrier substrate;

- dielectric layer;

- first semitransparent metallic layer.

The layer thickness of the second semitransparent metallic layer is preferably at least partially 1.25 to 3 times, particularly preferably 1.5 to 2 Times as high as the layer thickness of the first semitransparent metallic layer.

12. (Preferred Embodiment) A security element according to paragraph 10 or 11, wherein the second semitransparent metallic layer defines the front side of the semitransparent functional layer and the first semi-transparent functional layer defines the back side of the semitransparent functional layer and the semitransparent functional layer

- When viewing the front in incident light has a second visually recognizable color;

- When viewing both the front in the transmitted light, as well as the back in the transmitted light has a third, visually recognizable color; and

- When viewing the back and / or when viewing the front in incident light has a viewing angle-dependent color impression.

13. (Preferred embodiment) A security element according to paragraph 10, 11 or 12, wherein the one semitransparent metallic layer of Al or Ag is selected, the further semitransparent metallic layer is a Cr layer and the dielectric layer is a Si0 ₂ layer, wherein the layer thickness of the Al or Ag layer is at least partially 1.25 to 3 times, particularly preferably 1.5 to 2 times, as high as the layer thickness of the Cr layer.

14. (Preferred Embodiment) A security element according to paragraph 13, wherein the one semitransparent metallic layer is an Al layer, the further semitransparent metallic layer is a Cr layer, and the dielectric layer is a Si0 ₂ layer. 15. (Preferred embodiment) A security element according to any one of paragraphs 1 to 14, wherein the security element is a (endless) strip _/ (endless) thread or a patch or label.

16. (Preferred embodiment) A security element according to one of the paragraphs 1 to 15, wherein between the transparent carrier substrate and the semitransparent functional layer an embossing lacquer layer is present which in particular has a relief structure forming a diffractive structure and / or a relief structure forming a micromirror arrangement.

17. (Second aspect of the invention) Data carrier with a security element according to one of the paragraphs 1 to 16.

18. (Preferred embodiment) Data carrier according to paragraph 17, wherein the data carrier is a value document, such as a banknote, in particular a paper banknote, polymer banknote or composite film banknote, or identity card.

19. (Preferred embodiment) Data carrier according to paragraph 17 or 18, wherein the security element is arranged above a window region formed in the data carrier substrate.

20. (Third aspect of the invention) A method for producing a security element for securing value documents, comprising a transparent carrier substrate and a first semitransparent functional layer having a multilayer structure comprising a first semitransparent metallic layer, a second semitransparent metallic layer and one between the first and second the second semi-transparent metallic layer disposed dielectric layer, wherein the second semitransparent metallic layer at least partially in a larger Layer thickness than that of the first semitransparent metallic layer, the method comprising the following steps:

a) providing a transparent carrier substrate;

b) optionally providing the transparent carrier substrate with an embossing lacquer layer which in particular has a relief structure forming a diffractive structure and / or a relief structure forming a micromirror arrangement; c) the full-surface application of a multilayer structure comprising a first semitransparent metallic layer, a second semitransparent metallic layer and a dielectric layer arranged between the first and the second semitransparent metallic layer;

d) printing a soluble wash ink at least partially on the last applied second semitransparent metallic layer;

e) full-surface application of additional semitransparent metal; f) washing off the wash ink together with the area of the semitransparent applied in step e) above the wash dye

Metal. The layer thickness of the second semitransparent metallic layer is preferably at least partially 1.25 to 3 times, particularly preferably 1.5 to 2 times as high as the layer thickness of the first semitransparent metallic layer.

Detailed description of the invention

The value document referred to in the present description can be a banknote, in particular a paper banknote, a banknote or composite film banknote, a share, a bond, a certificate, a coupon, a check, a high-quality admission ticket, but also an identification card, such as a credit card, a bank card, a cash card, an authorization card, an identity card or pass personalization page act. A viewing in reflected light is in the sense of this invention an illumination of the security element from one side and a view of the security element from the same side, preferably at a viewing angle of the security element of about 90 °. A reflection in reflected light is thus present, for example, when the front of the security element is illuminated and also viewed.

A viewing angle-dependent color impression in reflected light means that viewing the security element in reflected light at a viewing angle of approximately 90 ° results in a certain optically perceptible color and at a viewing angle of approximately 20 ° to 40 ° results in a further optically perceptible color ,

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 reflection in transmitted light is thus, for example, when the back of the security element illuminated and the front of the security element is considered. The light thus shines through the security element.

The fiction, contemporary security element can be present as a patch or label, as (endless) strip or as (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. In the case of a paper substrate, a paper / film / paper composite substrate or a film / paper / film composite substrate, a value document or security paper provided with a window area can be used, for example, by means of a existing recess within the paper layer (s) are generated. Alternatively, the paper layer can be made transparent by means of a suitable liquid, for example by means of aqueous sulfuric acid solution, within a certain range. In the case of a value document based on a transparent polymer substrate, a window region can be produced, for example, by means of congruent recesses in the opaque printed layers applied to the front and back of the polymer substrate.

The semitransparent functional layer, on the other hand, has different hues when viewed in reflected light on the one hand and when viewed in transmitted light on the other hand. The two different shades are e.g. Complementary colors. Such a semitransparent functional layer is based e.g. on a multi-layered structure with two semitransparent metallic layers and a dielectric layer arranged between the two semitransparent metallic layers. Such a multi-layered structure, which appears gold-colored when viewed in reflected light and shows a blue hue when viewed in transmitted light, is e.g. known from WO 2011/082761 AI.

The following description relates in particular to the variant according to which the two semitransparent metallic layers are each based on the same metal.

Suitable multi-layered structures with two semitransparent metallic layers and a dielectric layer arranged between the two semitransparent metallic layers typically have the following physical properties:

the two semitransparent metallic layers are preferably selected from Al or Ag; the dielectric layer is in particular a SiC layer; in the case where each of the two semitransparent metallic layers is based on Al, the respective preferred layer thickness is in a range of 5 nm to 20 nm, particularly preferably in a range of 10 nm to 14 nm; the dielectric SiC 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, especially for the provision of a gold / blue color change particularly preferred;

in the case where each of the two semitransparent metallic layers is based on Ag, the respective preferred layer thickness is in a range of 15 nm to 25 nm; the SiC 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 210 nm to 240 especially preferred for providing a gold / blue color change.

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

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

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

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

- in light silver, in transmitted light violet.

The security element according to the invention has a first semitransparent functional layer with a multilayer structure with a first semitransparent functional layer. a transparent metallic layer, a second semitransparent metallic layer and a dielectric layer arranged between the first and the second semitransparent metallic layer, wherein the semitransparent functional layer is such that the second semitransparent metallic layer at least partially has a greater layer thickness than the first semitransparent metallic layer is present. It is preferred that the layer thickness of the second semitransparent metallic layer is 1.5 to 2 times as high as the layer thickness of the first semitransparent metallic layer. In this way, it can be ensured that the observer immediately perceives a second visually recognizable color when viewing the front side in incident light at the location where the second semitransparent metallic layer is present in a greater layer thickness than the first semitransparent metallic layer, and otherwise perceives the first visually recognizable color.

According to a preferred variant, the security element according to the invention is such that the transparent carrier substrate has, in addition to the first semitransparent functional layer, a second semitransparent functional layer obtainable by means of an effect pigment composition, wherein the second semitransparent functional layer, viewed from incident light, both from the rear side , as well as from the front appears in the first, visually recognizable color and when viewed in transmitted light, both from the back and from the front appears in the third, visually recognizable color.

Printed layers based on an effect pigment composition which, when viewed in incident light, shows a different color than when viewed in transmitted light, in particular a gold / blue color change

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 WO 2011/064162 A2. The pigments preferably have a longest dimension from end-to-end ("longest dimension of edge length ") range from 15 nm to 1000 nm and are based on a transition metal selected from the group consisting of Cu, Ag, Au, Zn, Cd, Ti, Cr, Mn, Fe, Co, Ni, Ru, Rh The transition metal is preferably Ag. The aspect ratio (ie the ratio of the longest end-to-end dimension relative to the thickness) is preferably at least 1.5, in particular in the range of 1 The ratio of binder to metal pigment is preferably below 10: 1, more preferably below 5: 1, depending on the choice of aspect ratio of the pigment, its longest end-to-end dimension, and the setting of the pigment Pigment / binder ratio, the color can be adjusted in transmission and the color when viewed in reflection (eg, blue in transmission and silver, gold, bronze, copper or violet in reflection, violet, magenta, etc.). Pink, green or brown i n transmission and different colors in reflection, which depend on the choice of pigment / binder ratio). Colors with gold / blue color change between reflection and transmission (in other words, between incident light and transmitted light observation) are mentioned, for example, in Examples 1, 2 and 3 in Table 1 of WO 2011/064162 A2. Further, Example 4 shows a color with gold / violet color change, Example 5 a color with green-gold / magenta color change, Example 7 a color with violet / green color change and Example 8 a color with silver / opaque color change.

According to an advantageous variant (A), the security element according to the invention has the following layer sequence:

a) transparent carrier substrate, e.g. Polyethylene terephthalate (PET) film; b) optionally an embossing lacquer layer which has, in particular, a relief structure forming a diffractive structure and / or a relief structure forming a micromirror arrangement;

c) a first semitransparent metallic layer, e.g. Aluminum;

d) a dielectric layer, eg S1O2; e) a second semitransparent metallic layer, for example aluminum, which is present at least partially in a greater layer thickness than that of the first semitransparent metallic layer.

f) optionally an adhesive layer, e.g. a heat seal coating suitable for bonding the security element to a data carrier, e.g. a value document, is suitable.

According to a further, advantageous variant (B), the security element according to the invention has the following layer sequence:

A) transparent carrier substrate, e.g. Polyethylene terephthalate (PET) film;

B) optionally an embossing lacquer layer which has, in particular, a relief structure forming a diffractive structure and / or a relief structure forming a micromirror arrangement;

both C) a first semitransparent functional layer, and C2) a second semitransparent functional layer in juxtaposition, i. the first and the second semitransparent functional layer may in particular be arranged in adjacency to one another or spaced from one another, wherein

the first semitransparent functional layer has the following layers:

Cla) a first semitransparent metallic layer, e.g. Aluminum;

Clb) a dielectric layer, e.g. S1O2;

Clc) a second semitransparent metallic layer, e.g. Aluminum, which is present in a greater layer thickness than that of the first semitransparent metallic layer; and

the second semitransparent functional layer C2) can be obtained by printing technology by means of the above-described effect pigment composition known from WO 2011/064162 A2;

D) if appropriate, an adhesive layer, for example a heat-seal coating, which is suitable for bonding the security element to a data carrier, for example a value document. The first semitransparent functional layer mentioned in the above variants may alternatively be an Ag / SiO 2 / Ag structure instead of an Al / SiO 2 / Al structure.

In addition, the order of layers can be changed. For example, For example, the semitransparent metallic layer of high layer thickness can first be arranged on the carrier substrate, followed by the dielectric layer and finally the further metallic layer of small layer thickness.

The following description refers in particular to the variant according to which the two semitransparent metallic layers are based on different metals.

- The one semitransparent metallic layer, which has a higher layer thickness with respect to the further semitransparent metallic layer, is preferably selected from Al or Ag, particularly preferred is an Al layer; the dielectric layer is in particular a Si0 ₂ layer;

the further semitransparent metallic layer is preferably a Cr layer;

in the case where the one semitransparent metallic layer is based on Al, the preferred layer thickness is in a range of 5 nm to 15 nm; the Si0 ₂ dielectric layer preferably has a layer thickness in a range of 50 nm to 700 nm; the Cr layer has a preferred layer thickness in a range of 3 nm to 7 nm, particularly preferably a layer thickness of about 5 nm. Due to the fact that the two semitransparent metallic layers are based on different metals, preferably Al and Cr, the layer build-up when viewing the front side in incident light (ie 90 °) on the one hand, and on the other hand when viewing the rear side in incident light (ie 90 °) different colors. In addition, the layer structure when viewed in transmitted light has another color. In addition, the layer structure when viewing the front and / or the back in reflected light shows a color impression that is viewing angle dependent.

A three-layer structure AI (about 12nm) / S1O2 (about 220nm) / Cr (about 5nm), for example, leads to the following color impressions:

- Page 1 in incident light at a viewing angle of approximately 90 °: blue;

- Page 1 in reflected light at a viewing angle of about 20 ° to 40 °: red-brown;

- Page 2 in incident light: gold (regardless of the viewing angle);

- Page 1 and Page 2 when viewed in transmitted light: Purple.

By varying the layer thickness of the dielectric layer, the color impressions can be changed in a simple manner, for example:

- Page 1 in reflected light at a viewing angle of about 90 °: green;

- Page 1 in reflected light at a viewing angle of about 20 ° to 40 °: blue-violet;

- Page 2 in reflected light at a viewing angle of 90 °: Magenta;

- Page 2 in reflected light at a viewing angle of approximately 20 ° to 40 °:

Gold;

- Page 1 and Page 2 when viewed in transmitted light: Green.

According to an advantageous variant, the above security element has the following layer sequence:

a) transparent carrier substrate, eg polyethylene terephthalate (PET) film; b) optionally an embossing lacquer layer which has, in particular, a relief structure forming a diffractive structure and / or a relief structure forming a micromirror arrangement;

c) a semi-transparent metallic layer, e.g. Aluminum or silver, preferably aluminum, which has a greater layer thickness relative to the further semitransparent metallic layer;

d) a dielectric layer, e.g. S1O2;

e) another semitransparent metallic layer, e.g. Cr;

f) optionally an adhesive layer, e.g. a heat seal coating suitable for bonding the security element to a data carrier, e.g. one

Value document, is suitable.

As an alternative to the above layer structure, the layer sequence may also be a, b, e, d, c, f, i. the Al layer (or Ag layer) and the Cr layer are present in a mutually exchanged form.

Further exemplary embodiments and advantages of the invention will be 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.

Show it:

Figure 1 fiction, according security element;

FIG. 2 shows a further security element according to the invention;

Figure 3 is yet another inventive security element. 1 shows a document of value, namely a banknote, with a window area and a security element applied to the value document substrate in the window area. The window region of the value document is formed by a recess 2, for example, produced by punching in the paper layer 1. The security element has the following layers:

a) a carrier substrate 7, e.g. a PET (polyethylene terephthalate) film;

b) an aluminum metallization 6 with comparatively small layer thickness, e.g. 5 to 15 nanometers;

c) a SiCh layer 5 with a layer thickness e.g. from 210 to 240 nanometers; d) an aluminum metallization 4 with comparatively high layer thickness, e.g. 15 to 30 nanometers;

e) an adhesive layer 3, e.g. a heat seal coating.

The aluminum metallization 4 with comparatively high layer thickness represents the front side of the semitransparent functional layer comprising the layers 4, 5, and 6. The aluminum metallization 6 with a comparatively small layer thickness represents the rear side of the semitransparent functional layer comprising the layers 4, 5, and 6.

The block arrow 8 shows the viewing of the front of the security element. The observer perceives the security element when viewing the front of the security element in the reflected light in silver color.

The block arrow 9 shows the viewing of the back of the security element. The observer perceives the security element in golden color when viewing the rear side of the security element in reflected light.

The security element appears when viewed in transmitted light, both from the front, as well as from the back, in the color blue. The security element comprising layers 3 to 7 shown in FIG. 1 can additionally have an embossing lacquer layer, eg a UV lacquer, between the aluminum metallization 6 and the carrier substrate 7, in particular a relief structure forming a diffractive structure and / or a micromirror arrangement contains forming relief structure.

FIG. 2 shows a security element according to the invention in accordance with a further exemplary embodiment. The security element has the following layers:

a) a carrier substrate 10, e.g. a PET (polyethylene terephthalate) film;

b) an aluminum metallization 11 having a layer thickness e.g. from 5 to 15 nanometers;

c) a Si0 ₂ layer 12 with a layer thickness of, for example, 210 to 240 nanometers;

d) an aluminum metallization 13 with the same layer thickness as the aluminum metallization 11;

e) another aluminum metallization 14 having a layer thickness e.g. from 5 to 15 nanometers.

The aluminum metallizations 13 and 14, which together form a metallization with a comparatively high layer thickness, represent the front side of the semitransparent functional layer comprising the layers 11, 12, 13 and 14. The aluminum metallization 11 represents the rear side of the semitransparent functional layer comprising the layers 11, 12, 13 and 14.

The block arrows 15 and 16 show the viewing of the front of the security element. The observer perceives the security element when viewing the front of the security element in incident light at the point of the block arrow 15 in silver color. Furthermore, the viewer takes the Security element when viewing the front of the security element in incident light at the point of the block arrow 16 in true golden.

The block arrows 17 and 18 show the viewing of the back of the security element. The viewer perceives the security element when viewing the back of the security element in incident light both at the point of the block arrow 17, as well as in the place of the block arrow 18 in golden color.

The security element appears when viewed in transmitted light, both from the front, as well as from the back, in the color blue, namely at all points of the block arrows 15, 16, 17 and 18th

The security element may have, above the aluminum metallizations 13 and 14, an adhesive layer, in particular a heat-seal coating, for bonding the security element to a value-document substrate.

Furthermore, the security element comprising layers 10 to 14 shown in FIG. 2 may additionally comprise between the aluminum metallization 11 and the substrate substrate 10 an embossing lacquer layer, e.g. a UV varnish having, in particular, a structure forming a diffractive structure relief structure and / or a micromirror arrangement forming relief structure.

FIG. 3 shows a security element according to the invention according to a further exemplary embodiment, which has the following layer sequence:

A) a transparent carrier substrate 19, e.g. a polyethylene terephthalate (PET) film;

both Bl) a first semitransparent functional layer comprising the layers 20, 21 and 22, and B2) a second comprising the layer 23 Semitransparent functional layer in juxtaposition, ie be arranged in the present case in adjacency to each other, wherein

the first semitransparent functional layer has the following layers:

Bla) a comparatively thin aluminum metallization 20 with a layer thickness, e.g. from 5 to 15 nanometers;

Blb) a SiCV layer 21 having a layer thickness e.g. from 210 to 240 nanometers;

Blc) a comparatively thick aluminum metallization 22 with a layer thickness, e.g. from 15 to 30 nanometers; and

- The second semitransparent functional layer B2) is technically available by means of the above-described, known from WO 2011/064162 A2 effect pigment composition and appears in incident light gold and blue in transmitted light.

The aluminum metallization 22 represents the front of the security element. The aluminum metallization 20 represents the back of the security element. The block arrows 24 and 25 show the viewing of the front of the security element. The viewer perceives the security element when viewing the front of the security element in incident light in the place of the block arrow 24 in silver color. Furthermore, the observer perceives the security element in the incident light at the location of the block arrow 25 in golden color when viewing the front of the security element.

The block arrows 26 and 27 show the viewing of the back of the security element. The observer perceives the security element when viewing the back of the security element in incident light both at the point of the block arrow 26, as well as in the place of the block arrow 27 in golden color. The security element can above the aluminum metallization 22 and the effect pigment layer 23 an adhesive layer, in particular a

A heat seal coating for bonding the security element to a value document substrate.

Furthermore, the security element shown in FIG. 3 may additionally have an embossing lacquer layer, for example, between the aluminum metallization 20 and / or the effect pigment layer 23 on the one hand, and the carrier substrate 19 on the other hand. a UV varnish, in particular a diffractive

Structure-forming relief structure and / or a micromirror arrangement forming relief structure contains.

In the above embodiments, aluminum was selected to produce the semi-transparent metallic layer. Instead of aluminum, e.g. Silver can be used.

Claims

Patent claims

A security element for securing value documents, comprising a transparent carrier substrate and a first semitransparent functional layer, which has a multilayer structure with a first semitransparent metallic layer, a second semitransparent metallic layer and a dielectric layer arranged between the first and the second semitransparent metallic layer, wherein the second semitransparent metallic layer is at least partially present in a greater layer thickness than that of the first semitransparent metallic layer.

2. The security element of claim 1, wherein both the first semitransparent metallic layer and the second semitransparent metallic layer are based on the same metal.

The security element according to claim 1 or 2, wherein the security element has the following layer structure in order:

transparent carrier substrate;

- first semitransparent metallic layer;

- dielectric layer;

or the security element has the following layer structure in order:

transparent carrier substrate;

- dielectric layer; - first semitransparent metallic layer.

4. The security element according to claim 1, 2 or 3, wherein the second semitransparent metallic layer defines the front side of the semitransparent functional layer and the first semitransparent functional layer defines the back side of the semitransparent functional layer and the semitransparent functional layer

5. The security element according to claim 4, wherein the two semitransparent metallic layers of Al or Ag are selected and the dielectric layer is a SiO ₂ layer and the visually recognizable colors are preferably the following colors:

- the first visually recognizable color is gold;

the second visually recognizable color is silver;

- the third visually recognizable color is blue.

The security element according to any one of claims 1 to 5, wherein the first semitransparent functional layer having a multilayer structure is so obtained in that the first semitransparent metallic layer and the dielectric layer are each present in a uniform layer thickness and the second semitransparent metallic layer has the same layer thickness in first regions as the first semitransparent metallic layer and in second regions has a greater layer thickness than that of the first semitransparent metallic layer having.

7. Security element according to claim 6, wherein the security element

- When looking at the back in the incident light appears golden;

8. The security element according to claim 1, wherein the transparent carrier substrate of the security element has, in addition to the first semitransparent functional layer, a second semitransparent functional layer which can be obtained by means of an effect pigment composition, the second semitransparent functional layer being viewed in reflected light, both from the back, as well as from the front appears in the first, visually recognizable color and when viewed in transmitted light, both from the back and from the front in the third, visually recognizable color appears.

9. The security element according to claim 8, wherein the second semitransparent functional layer appears golden when viewed in reflected light, both from the rear side and from the front side, and when viewed in transmitted light, both from the rear side and from the front side. appears bluish.

The security element of claim 1, wherein the metal of the first semitransparent metallic layer and the metal of the second semitransparent metallic layer are different metals.

The security element according to claim 10, wherein the security element has the following layer structure in order:

transparent carrier substrate;

- first semitransparent metallic layer;

- dielectric layer;

or the security element has the following layer structure in order:

- transparent carrier substrate;

- dielectric layer;

- first semitransparent metallic layer.

12. The security element according to claim 10, wherein the second semitransparent metallic layer defines the front side of the semitransparent functional layer and the first semitransparent functional layer defines the rear side of the semitransparent functional layer and the semitransparent functional layer

- has a second visually recognizable color when viewing the front side in reflected light;

- when viewing both the front in the transmitted light, and the Rear in transmitted light has a third, visually recognizable color; and - has a viewing angle-dependent color impression when viewing the back and / or when viewing the front in incident light.

13. A security element according to claim 10, 11 or 12, wherein the one semitransparent metallic layer of Al or Ag is selected, the further semitransparent metallic layer is a Cr layer and the dielectric layer is a SiC layer, wherein the layer thickness of the Al or Ag layer is at least partially 1.25 to 3 times, particularly preferably 1.5 to 2 times, as high as the layer thickness of the Cr layer.

14. The security element according to claim 13, wherein the one semitransparent metallic layer is an Al layer, the further semitransparent metallic layer is a Cr layer and the dielectric layer is a SiO ₂ layer.

15. Security element according to one of claims 1 to 14, wherein the security element is an (endless) strip, an (endless) thread or a patch or label.

16. The security element according to claim 1, wherein an embossing lacquer layer is present between the transparent carrier substrate and the semitransparent functional layer, which has in particular a relief structure forming a diffractive structure and / or a relief structure forming a micromirror arrangement.

17. A data carrier with a security element according to one of claims 1 to 16.

18. A data carrier according to claim 17, wherein the data carrier is a value document, such as a banknote, in particular a paper banknote, polymer banknote or composite film banknote, or identity card.

19. A data carrier according to claim 17 or 18, wherein the security element is arranged above a window area formed in the data carrier substrate.

20. A method for producing a security element for securing value documents, comprising a transparent carrier substrate and a first semitransparent functional layer, which has a multilayer structure with a first semitransparent metallic layer, a second semitransparent metallic layer and a metal layer arranged between the first and second semitransparent metallic layers dielectric layer, wherein the second semitransparent metallic layer is at least partially in a greater layer thickness than that of the first semitransparent metallic layer, the method comprising the following steps:

a) providing a transparent carrier substrate;

b) optionally providing the transparent carrier substrate with an embossing lacquer layer which in particular has a relief structure forming a diffractive structure and / or a relief structure forming a micromirror arrangement; c) applying a multi-layered structure over a full area comprising a first semitransparent metallic layer, a second semitransparent metallic layer and a dielectric layer disposed between the first and second semitransparent metallic layers; d) printing a soluble wash ink at least partially on the last applied second semitransparent metallic layer;

e) full-surface application of additional semitransparent metal; f) the washing off of the washing ink together with the region of the semitransparent metal applied above the wash ink in the step e).