DE102023128009A1 - Method for producing a multilayer body and multilayer body - Google Patents

Abstract

The invention relates to a method for producing a multi-layer body (10), in particular a security element for securing security documents, preferably designed as a hot stamping foil or cold stamping foil or laminating foil, having at least two different color shift effects perceptible to the human eye and/or a sensor, wherein the method comprises the following steps:
a) Provision of a raw material (1, 11)
b) Applying an absorber layer (2, 12)
c) applying a first dielectric layer (3, 13) with a first predetermined thickness (d1)
d) applying a first reflector layer (4, 14)
e) applying a second dielectric layer (5, 15) with a second predetermined thickness (d3)
f) applying at least one primer (6, 17), and wherein in the method for generating the two different colour shift effects
I) the first reflector layer (14) is removed in a β-region (β), so that the first reflector layer (14) is present in an α-region (α) and is not present in the β-region (β), so that a first color shift effect is present in the α-region (α) and a second color shift effect is present in the β-region (β), wherein the first color shift effect differs from the second color shift effect wherein in a step g) a second reflector layer (7, 16) is applied and wherein the process steps are carried out in the following order: a), b), c), d), e), g) f)
or
II) the first dielectric layer (13) is structured by means of a lift-off process, so that the first dielectric layer (13) is present in an α-region (α) and not present in a β-region (β) or vice versa, so that a first color shift effect is present in the α-region (α) and a second color shift effect is present in the β-region (β), wherein the first color shift effect differs from the second color shift effect and wherein the method steps are carried out in the following order: a), b), c), e), d), f).

Description

The invention relates to a method for producing a multi-layer body, in particular a security element, and to a multi-layer body, in particular a security element.

The generation of optically variable effects using thin-film interference filters is, for example, US 3858977 described. Here, a thin-film interference filter is constructed from several layers comprising an interference layer. The incident light is at least partially reflected at the front and back of the interference layer. Due to the small thickness of the interference layer, destructive or constructive interference of the reflected light occurs for certain wavelengths in the visible light range, so that the thin-film interference filter has a colored appearance. Because the path length of the light in the interference layer changes depending on the viewing angle and/or illumination angle, the color of the thin-film interference filter changes accordingly depending on the viewing angle and/or illumination angle, so that such a filter generates a color dependent on the viewing angle and/or illumination angle as an optically variable effect when illuminated.

In general, there is the problem that thin-film effects can now be imitated by counterfeiters.

The invention is based on the object of specifying a method for producing a multi-layer body, in particular a security element, and a multi-layer body, in particular a security element, which enable improved optical effects and also increase the security against counterfeiting.

• a) Bereitstellen eines Vormaterials
• b) Aufbringen einer Absorberschicht
• c) Aufbringen einer ersten dielektrischen Schicht mit einer ersten vorbestimmten Dicke
• d) Aufbringen einer ersten Reflektorschicht
• e) Aufbringen einer zweiten dielektrischen Schicht mit einer zweiten vorbestimmten Dicke
• f) Aufbringen zumindest einer Grundierung, und wobei bei dem Verfahren zur Generierung der zwei unterschiedlichen Farbkippeffekte
• I) die erste Reflektorschicht in einem β-Bereich entfernt wird, sodass in einem α-Bereich die erste Reflektorschicht vorliegt und im β-Bereich nicht vorliegt, sodass im α-Bereich ein erster Farbkippeffekt und im β-Bereich ein zweiter Farbkippeffekt vorliegt, wobei sich der erste Farbkippeffekt von dem zweiten Farbkippeffekt unterscheidet, wobei in einem Schritt g) eine zweite Reflektorschicht (7, 16) aufgebracht wird und wobei die Verfahrensschritte in der folgenden Reihenfolge durchgeführt werden: a), b), c),d), e), g), f)

oder II) die erste dielektrische Schicht mittels eines Lift-Off-Prozesses strukturiert wird, sodass die erste dielektrische Schicht in einem α-Bereich vorliegt und in einem β-Bereich nicht vorliegt oder umgekehrt, sodass im α-Bereich ein erster Farbkippeffekt und im β-Bereich ein zweiter Farbkippeffekt vorliegt, wobei sich der erste Farbkippeffekt von dem zweiten Farbkippeffekt unterscheidet und wobei bei die Verfahrensschritte in der folgenden Reihenfolge durchgeführt werden: a), b), c), e), d), f).The object is achieved by a method for producing a multi-layer body, in particular a security element for securing security documents, preferably designed as a hot stamping foil or cold stamping foil or laminating foil, having at least two different color shift effects perceptible to the human eye and/or a sensor, wherein the following steps are carried out in the method:

• a) Provision of a raw material
• b) Applying an absorber layer
• c) applying a first dielectric layer having a first predetermined thickness
• d) Applying a first reflector layer
• e) applying a second dielectric layer having a second predetermined thickness
• f) applying at least one primer, and wherein in the process for generating the two different colour shift effects
• I) the first reflector layer is removed in a β-region, so that the first reflector layer is present in an α-region and not present in the β-region, so that a first color shift effect is present in the α-region and a second color shift effect is present in the β-region, wherein the first color shift effect differs from the second color shift effect, wherein in a step g) a second reflector layer (7, 16) is applied and wherein the method steps are carried out in the following order: a), b), c), d), e), g), f)

or II) the first dielectric layer is structured by means of a lift-off process, so that the first dielectric layer is present in an α-region and not present in a β-region or vice versa, so that a first color shift effect is present in the α-region and a second color shift effect is present in the β-region, wherein the first color shift effect is different from the second color shift effect and wherein the method steps are carried out in the following order: a), b), c), e), d), f).

• I) die erste Reflektorschicht in einem β-Bereich entfernt ist, sodass in einem α-Bereich die erste Reflektorschicht vorliegt und im β-Bereich nicht vorliegt, sodass im α-Bereich ein erster Farbkippeffekt und im β-Bereich ein zweiter Farbkippeffekt vorliegt, wobei sich der erste Farbkippeffekt von dem zweiten Farbkippeffekt unterscheidet, wobei der Mehrschichtkörper eine zweite Reflektorschicht aufweist und wobei die Schichten in der folgenden Reihenfolge, bevorzugt bei Blickrichtung von vorne, angeordnet sind: Vormaterial, Absorberschicht, erste dielektrische Schicht, erste Reflektorschicht, zweite dielektrische Schicht, zweite Reflektorschicht, zumindest eine Grundierung oder
• II) die erste dielektrische Schicht strukturiert ist, sodass die erste dielektrische Schicht in einem α-Bereich vorliegt und in einem β-Bereich nicht vorliegt oder umgekehrt, sodass im α-Bereich ein erster Farbkippeffekt und im β-Bereich ein zweiter Farbkippeffekt vorliegt, wobei sich der erste Farbkippeffekt von dem zweiten Farbkippeffekt unterscheidet und wobei die Schichten in der folgenden Reihenfolge angeordnet sind: Vormaterial, Absorberschicht, erste dielektrische Schicht, zweite dielektrische Schicht, erste Reflektorschicht, zumindest eine Grundierung.

This object is further achieved by a multi-layer body, in particular a security element for securing security documents, preferably hot stamping foil or cold stamping foil or laminating foil, in particular produced by a method according to claims 1 to 21, having at least two different color shift effects perceptible to the human eye and/or a sensor, wherein the multi-layer body comprises a precursor material, an absorber layer, a first dielectric layer with a first predetermined thickness, a first reflector layer, a second dielectric layer with a second predetermined thickness and at least one primer, and wherein in the multi-layer body for generating the two different color shift effects

• I) the first reflector layer is removed in a β-region, so that the first reflector layer is present in an α-region and not present in the β-region, so that a first color shift effect is present in the α-region and a second color shift effect is present in the β-region, wherein the first color shift effect differs from the second color shift effect, wherein the multi-layer body has a second reflector layer and wherein the layers are arranged in the following order, preferably when viewed from the front: precursor material, absorber layer, first dielectric layer, first reflector layer, second dielectric layer, second reflector layer, at least one primer or
• II) the first dielectric layer is structured such that the first dielectric layer is present in an α-region and not present in a β-region or vice versa, such that a first color shift effect is present in the α-region and a second color shift effect is present in the β-region, wherein the first color shift effect differs from the second color shift effect and wherein the layers are arranged in the following order: precursor material, absorber layer, first dielectric layer, second dielectric layer, first reflector layer, at least one primer.

It has been shown that the method according to the invention for producing a multilayer body, in particular a security element for securing security documents, results in a multilayer body which has increased security against counterfeiting due to the two different color-shift effects. To generate the two different color-shift effects, the structuring of at least one layer in the layer structure of the multilayer body is necessary. This structuring cannot generally be produced using conventional printing processes. This sometimes requires complex techniques that make it considerably more difficult for a counterfeiter to produce a copy of the multilayer body according to the invention. Furthermore, the two different color-shift effects generate a memorable visual impression of the multilayer body, in particular the security element, for the viewer, which differs from conventional security elements. Depending on the arrangement of the α region and the β region, in which the two color-shift effects are present, complex structures and effects can be created.

Further advantageous embodiments of the invention are described in the subclaims.

wobei 2x Θ der Winkel zwischen der Beleuchtungsrichtung und der Betrachtungsrichtung, λ die Wellenlänge des Lichts und m eine ganze Zahl ist. Der Winkel Θ ist der Winkel zwischen Oberflächen-Normalen und Beleuchtungsrichtung oder Betrachtungsrichtung.Color-shift effects based on thin-film interference (hereinafter referred to as the thin-film effect) are characterized in particular by the fact that, when illuminated, they generate a color that depends on the viewing angle and/or illumination angle. This color is at least partly determined by the occurrence of constructive/destructive interference of the light reflected from the top and back of the interference layer. In contrast to first-order or higher-order diffractive effects, the illumination angle is equal to the viewing angle. The constructive interference in an interference layer with a refractive index n and a thickness d is calculated as follows: $$2\text{nd cos}\left(\mathrm{\Theta }\right)=\text{m}\mathrm{\lambda }\mathrm{,}$$

where 2x Θ is the angle between the illumination direction and the viewing direction, λ is the wavelength of the light, and m is an integer. The angle Θ is the angle between the surface normal and the illumination direction or viewing direction.

Multilayer bodies, particularly security elements, with color-shift effects preferably have a thin-layer structure. For example, this can be a three-layer structure, preferably comprising an absorber layer, a dielectric layer, and a reflector layer. Such a layer structure is often referred to as a Fabry-Perot filter or Fabry-Perot layer structure.

As already mentioned above, the α-region and the β-region can be arranged differently. Furthermore, the multilayer body can also have a γ-region and/or δ-region and/or ε-region and/or ζ-region. Each of the α-region and/or β-region and/or γ-region and/or δ-region and/or ε-region and/or ζ-region can have a plurality of subregions, which are preferably arranged separately from one another and/or adjacently and/or overlappingly. For example, the γ-region can be formed from two or more subregions, wherein the two or more subregions are arranged at a distance from one another. This embodiment can apply analogously to all regions and is not limited to the γ-region.

Preferably, the α-range is the range with which the first color shift effect is generated. Preferably, the multilayer body in the α-range according to variant I) has the following Layers, particularly when viewed from the front, in particular in the following order: absorber layer, first dielectric layer, first reflector layer, second dielectric layer, and second reflector layer. Preferably, the multilayer body in the α-range according to variant II) has the following layers, particularly when viewed from the front, in particular in the following order: absorber layer, first dielectric layer, and first reflector layer.

Preferably, the total area of the α-region, in particular the sum of all individual areas of the α-region, is at least 4 mm ² , more preferably at least 6 mm ² , particularly preferably at least 9 mm ² , wherein in particular the extent of the individual areas of the α-region in both the x-direction and the y-direction is at least 1 mm each, preferably at least 2 mm each. This ensures that the color shift effect in the α-region is clearly perceptible to the human eye.

Preferably, the β-region is the region with which the second color-shift effect is generated. Preferably, the multilayer body in the β-region according to variant I) has the following layers, particularly when viewed from the front, in particular in the following order: absorber layer, first dielectric layer, second dielectric layer, and second reflector layer.

Preferably, the multilayer body in the β-range according to variant II) has the following layers, in particular when viewed from the front, in particular in the following order: absorber layer, first dielectric layer, second dielectric layer and first reflector layer.

Preferably, the total area of the β-region, in particular the sum of all individual areas of the β-region, is at least 4 mm ² , more preferably at least 6 mm ² , particularly preferably at least 9 mm ² , wherein in particular the extent of the individual areas of the β-region in both the x-direction and the y-direction is at least 1 mm each, preferably at least 2 mm each. This ensures that the color shift effect in the β-region is clearly perceptible to the human eye.

Preferably, it can be provided that the α-region and the β-region are arranged directly next to each other and/or separated from each other and/or enclosing each other.

Preferably, the γ-region is a region of the multilayer body in which no metallic layers and dielectric layers are present. Preferably, the multilayer body in the γ-region has the following layers, particularly when viewed from the front, particularly in the following order: at least one primer.

The δ region is preferably a region of the multilayer body in which no metallic layers are present, but the first dielectric layer and/or the second dielectric layer is present. Furthermore, it is preferably provided that the multilayer body has at least one δ region in which the first reflector layer, the second reflector layer and the absorber layer are not present, and that the first dielectric layer and/or the second dielectric layer are present in at least one δ region. If the first dielectric layer and/or the second dielectric layer comprises an HRI material (HRI = High Refractive Index), structure-based optically variable effects can be present in the first dielectric layer and/or the second dielectric layer. Preferably, the multilayer body has the following layers in the δ region, in particular when viewed from the front, in particular in the following order: first dielectric layer and/or second dielectric layer.

The ε-region is preferably a region of the multilayer body in which at least one metallic layer is present and the first dielectric layer and/or the second dielectric layer is not present. Preferably, the multilayer body has the following layers in the ε-region, particularly when viewed from the front, particularly in the following order: absorber layer and/or first reflector layer and/or second reflector layer. Furthermore, it is possible for structure-based optical effects to be present in the ε-region in the absorber layer and/or in the first reflector layer and/or in the second reflector layer.

Preferably, the ζ region is a region of the multilayer body in which no metallic layer is present, but at least one color layer is present. Preferably, the multilayer body in the ζ region has the following layers, particularly when viewed from the front, particularly in the following order: first dielectric layer and/or second dielectric layer and at least one color layer.

Furthermore, it can be provided that the at least one ζ-region is present at least in some regions, in particular wherein the at least one ζ-region completely encloses the α-region and the β-region, preferably wherein the ζ-region is completely enclosed by the at least one δ-region.

Preferably, the total area of the ζ region, in particular the sum of all individual areas of the ζ region, is at least 4 mm ² , more preferably at least 6 mm ² , particularly preferably at least 9 mm ² , wherein in particular the extent of the individual areas of the ζ region in both the x-direction and the y-direction is at least 1 mm each, preferably at least 2 mm each. This ensures that the color in the ζ region is easily perceptible to the human eye.

All of the aforementioned regions, in particular the α region and/or β region and/or γ region and/or δ region and/or ε region and/or ζ region, can be combined with one another. All regions, in particular the α region and/or β region and/or γ region and/or δ region and/or ε region and/or ζ region, can be arranged adjacent to one another and/or separately from one another and/or enclosing a different region.

Furthermore, it can be provided that in all areas, in particular in the α-area and/or β-area and/or γ-area and/or δ-area and/or ε-area and/or ζ-area, the at least one primer and the precursor material, in particular the replication layer and/or the protective lacquer layer, are arranged.

“View from the front” is understood to mean the view of the raw material or the protective lacquer layer and/or replication layer of the multi-layer body, in particular the security element.

“View from behind” is understood to mean the view of at least one primer of the multi-layer body, in particular the security element, or in the applied state of the substrate.

“Registered” refers to the arrangement of one layer in relation to another layer or the structuring of a layer relative to another layer in a way that is accurate to register. Registered or register or accurate to register or register accuracy or register accuracy refers to the positional accuracy of two or more layers relative to one another. The register accuracy should be within a specified tolerance and as small as possible. At the same time, the register accuracy of several elements and/or layers in relation to one another is an important feature for increasing process reliability. Accurate positioning can be achieved in particular using sensory, preferably optically detectable, fiducials or register marks. These fiducials or register marks can either represent special separate elements or areas or layers or can themselves be part of the elements or areas or layers to be positioned.

In the present case, metallic layers are understood to mean in particular the absorber layer and/or the first reflector layer and/or the second reflector layer.

• - Bereitstellen eines Trägers
• - Beschichtung einer Ablöseschicht
• - Beschichtung zumindest einer Schutzlackschicht
• - Aufbringen einer Replizierschicht und optionales Einbringen von Strukturen in die Replizierschicht mittels thermischer Replikation oder UV-Replikation.

It is preferably possible that the following steps, in particular in the specified order, are carried out to provide the raw material in step a):

• - Providing a carrier
• - Coating of a release layer
• - Coating of at least one protective lacquer layer
• - Application of a replication layer and optional introduction of structures into the replication layer by means of thermal replication or UV replication.

When using the multilayer body as a stamping foil, particularly hot stamping foil or cold stamping foil, the carrier is removed after the multilayer body has been applied to a substrate. For this purpose, a release layer is preferably provided to facilitate the removal of the carrier foil.

It is preferably provided that the precursor material comprises, in particular in the following order, a carrier, a release layer, at least one protective lacquer layer and a replication layer, in particular in which structures are introduced into the replication layer by means of thermal replication or UV replication.

1. a) die folgenden Schritte, insbesondere in der angegebenen Reihenfolge, durchgeführt werden:
   • - Bereitstellen eines Trägers
   • - optionales Aufbringen einer Haftvermittlerschicht
   • - Aufbringen einer Replizierschicht und optionales Einbringen von Strukturen in die Replizierschicht mittels thermischer Replikation oder UV-Replikation.

It is also possible that in order to provide the raw material in step

1. a) the following steps are carried out, in particular in the order specified:
   • - Providing a carrier
   • - optional application of an adhesion promoter layer
   • - Application of a replication layer and optional introduction of structures into the replication layer by means of thermal replication or UV replication.

In contrast, when the multilayer body is used as a laminating film, the carrier remains in the layered structure. Thus, no release layer is required for the precursor material when the multilayer body is used as a laminating film.

It may also be possible for the precursor material to comprise, in particular in the following order, a carrier, an optional adhesion promoter layer and a replication layer, in particular wherein structures are introduced into the replication layer by means of thermal replication or UV replication.

Structure-based optically variable effects can be generated using the structures in the replication layer. These optically variable effects can preferably be superimposed on the first color-shift effect and/or the second color-shift effect or occur in combination. Structure-based optically variable effects are characterized by a structure or relief structure, which is typically molded into the replication layer. This structure or relief structure can be part of the thin-film structure or be present in a separate layer above or below this thin-film structure. The relief structure is preferably a structure, individually or in combination and/or as a superposition selected from: diffractive grating or zero-order diffraction structure, moth-eye structure, subwavelength grating - in particular linear grating, cross grating, hexagonal grating - furthermore, asymmetric grating structure, symmetric grating structure, hologram, blaze grating, binary grating, multi-stage phase grating, retroreflective structure, binary freeform surface, continuous freeform surface, diffractive macrostructure, refractive macrostructure, in particular a lens structure or microprism structure, micromirror or microfacets, microlens, microprism, anisotropic matt structure, isotropic matt structure.

A carrier is preferably understood to mean a single-layer or multi-layer film, one or more layers of which comprise in particular the following materials or combinations: PET (polyethylene terephthalate), PP (polypropylene), PE (polyethylene), PEN (polyethylene naphthalate), PC (polycarbonate), PVC (polyvinyl chloride), Kapton (polyoxydiphenylene pyromellitimide) or other polyimides, PLA (polylactate), PMMA (polymethyl methacrylate) or ABS (acrylonitrile butadiene styrene).

The layer thickness of the carrier is in particular in a range from 1 µm to 500 µm, preferably from 6 µm to 23 µm, more preferably from 6 µm to 16 µm.

The carrier itself can have an adhesion promoter layer. This adhesion promoter layer is applied during the carrier manufacturing process. The layer thickness of the adhesion promoter layer of a carrier supplied by the carrier supplier is preferably in the range of 0.1 µm to 5 µm. The primer materials listed below can be used as the adhesion promoter layer.

A primer or adhesion promoter layer increases the adhesion between two layers that would otherwise lack sufficient adhesion to one another. For example, this can be the adhesion of the replication layer to the carrier. The primer layer or adhesion promoter layer preferably comprises a material or combinations thereof selected from: polyester, polyacrylate, polymethacrylate, polyurethane, polystyrene, polybutyrate, nitrocellulose, polyvinyl chloride, ethylene-vinyl acetate, their copolymers, or similar polymers or mixtures thereof. The primer or adhesion promoter layer can be thermoplastic, chemically crosslinkable, UV-curable, a hybrid variant (thermoplastic and UV-curable or/or otherwise crosslinkable), a cold adhesive/primer, or a self-adhesive primer.

The primer or adhesion promoter layer preferably has a thickness in the range of 0.01 µm to 15 µm, preferably 0.1 µm to 5 µm. Inorganic materials such as metals, metal oxides, alloys, oxides, or silicates can also serve as adhesion promoters or be part of such a system.

The primer or adhesion promoter layer may also contain additives based on organic or inorganic substances that achieve a predetermined effect on the processing properties, for example, when applying a layer of the multilayer body in the above-mentioned process for producing a multilayer body or when using the multilayer body itself. The proportion of additives in the total coating of the primer or adhesion promoter layer is usually between 0% and 10%, preferably between 0% and 5%, and more preferably between 0.01% and 3%.

Furthermore, fillers can also be part of the formulation of a primer or adhesion promoter layer. This preferably includes all other materials added to a system, especially a polymer-based system, such as silica, pigments, dyes, tracers, especially taggants, and/or similar materials. The proportion of fillers in the total coating of the primer or adhesion promoter layer is usually between 0% and 80%.

In addition, primers or adhesion promoter layers can be formulated so that they remain tacky or even liquid even after the solvent has evaporated and/or before full curing. This is particularly advantageous when two substrates are to be bonded together over a large area, as is typically the case in a laminating process.

The increased adhesion between the substrate and the replication coating layer can optionally be achieved through surface-activating processes such as corona or plasma treatment. These can also be used in combination with a primer or adhesion promoter layer.

The release layer ensures, in particular, that the layers of the multilayer body can be separated from the carrier without destruction, particularly when used as an embossing foil or transfer foil as transfer layers. The release layer preferably comprises a material or combination of materials selected from: waxes, polyethylene (PE), polypropylene (PP), cellulose derivatives, and/or poly(organo)siloxanes. The aforementioned waxes can be natural waxes, synthetic waxes, or combinations thereof. Examples of aforementioned waxes include carnauba waxes. Examples of aforementioned cellulose derivatives include cellulose acetate (CA), cellulose nitrate (CN), cellulose acetate butyrate (CAB), or mixtures thereof. Examples of aforementioned poly(organo)siloxanes include, for example, silicone binders, polysiloxane binders, or mixtures thereof. The release layer preferably has a layer thickness in the range of 1 nm and 500 nm, in particular of 5 nm and 250 nm, preferably of 10 nm and 250 nm.

The protective lacquer layer provides protection against mechanical or physical-chemical stress. When the multilayer body is used as a laminating film, the carrier itself can function as a protective lacquer layer. When the multilayer body is used as a stamping foil, particularly hot stamping foil or cold stamping foil, the carrier is removed after the multilayer body has been applied. In this case, a protective lacquer layer is preferably provided, which, after the carrier has been removed, represents the outermost layer of the multilayer body in the applied state.

The protective coating layer is preferably a layer of PMMA, PVC, melamine, and/or acrylates. The protective coating layer can also be made from a radiation-curing dual-cure coating. This dual-cure coating can be thermally pre-crosslinked in a first step during and/or after application in liquid form. Preferably, in a second step, particularly after processing the primary material or the multilayer body, the dual-cure coating is post-crosslinked radically, particularly via high-energy radiation, preferably UV radiation. Dual-cure coatings of this type can consist of various polymers or oligomers containing unsaturated acrylate or methacrylate groups. These functional groups can be radically crosslinked with one another, particularly in the second step. For thermal pre-crosslinking in the first step, it is advantageous for these polymers or oligomers to also contain at least two or more alcohol groups. These alcohol groups can be crosslinked with multifunctional isocyanates or melamine-formaldehyde resins. Preferred unsaturated oligomers or polymers include various UV raw materials such as epoxy acrylates, polyether acrylates, polyester acrylates, and especially acrylate acrylates. Both blocked and unblocked isocyanates based on TDI (TDI = toluene-2,4-diisocyanate), HDI (HDI = hexamethylene diisocyanate), or IPDI (IPDI = isophorone diisocyanate) are suitable. Melamine crosslinkers can be fully etherified versions, imino types, or benzoguanamine crosslinkers.

The protective lacquer layer preferably has a layer thickness in the range from 50 nm to 30 µm, preferably from 1 µm to 5 µm. The protective lacquer layer can be applied by gravure printing, flexographic printing, screen printing, inkjet printing or by means of a slot nozzle and/or by vapor deposition, in particular by means of physical vapor deposition (PVD), chemical vapor deposition (CVD) and/or sputtering.

A replication layer is preferably understood here to be a special, functional layer 20 into which structures, preferably optically variable structures, are introduced and/or fixed, in particular by means of thermal replication and/or UV replication. In the case of a hybrid replication layer, this is replicated thermally, for example, and subsequently cured by means of radiation, for example by means of UV radiation and/or at least one electron beam. In the case of a UV-curing replication layer, this is preferably replicated at room temperature and simultaneously cured by means of radiation, for example by means of UV radiation and/or at least one electron beam. For example, it is possible that the varnish becomes warm during UV replication.

It is possible that the at least one replication layer has a layer thickness in the range of 0.1 µm to 30 µm, in particular in the range of 0.5 µm to 10 µm.

• k) Aufbringen eines Lift-Off-Lacks, insbesondere vor Schritt c);
• m) Entfernen des Lift-Off-Lacks gemeinsam mit den die Lift-Off-Schicht bedeckenden Schichten, insbesondere nach Schritt c).

It is preferably provided that in the method, in particular in variant II), the following steps are carried out for the lift-off process:

• k) applying a lift-off varnish, in particular before step c);
• m) removing the lift-off varnish together with the layers covering the lift-off layer, in particular after step c).

In variant II), the process steps are preferably carried out in the following order: a), b), k), c), m) e), d), f).

Preferably, in variant I), the second reflector layer is applied over the entire surface. Since in variant I) the first reflector layer is removed in the β-region and is therefore not present in the β-region, the second reflector layer in the β-region functions as the reflector layer that is necessary to design the thin-film structure. In the β-region, incident light is thus partially transmitted by the absorber layer and finally passes through the first dielectric layer and the second dielectric layer in the β-region, is reflected again at the second reflector layer by the aforementioned layers and generates a predetermined color for the viewer and/or sensor. The generated color depends significantly on the optical thickness of the first dielectric layer and the second dielectric layer in the β-region.

It is preferably provided that the first reflector layer and/or the second reflector layer comprises a material or combination of materials selected from: aluminum, chromium, copper, tin, silver, indium, nickel, iron, gold and/or an alloy of such metals. Thus, the first reflector layer and/or the second reflector layer is a metal layer or a metallization. The first reflector layer and/or the second reflector layer are preferably applied or produced by means of vacuum vapor deposition. The application of the first reflector layer and/or second reflector layer, for example by means of vapor deposition or printing, can take place over the entire surface or optionally remain over the entire surface or can be structured using demetallization processes such as etching, lift-off or photolithography and thus only partially present or only partially removed.

Preferably, the first reflector layer and/or the second reflector layer are opaque.

Furthermore, it is possible that the first reflector layer and/or the second reflector layer have a refractive index in the range of 1.65 to 1.9.

In particular, it can be provided that the first reflector layer and/or the second reflector layer, when applied by vapor deposition, has a layer thickness in the range of 10 nm to 100 nm. Alternatively, the first reflector layer and/or the second reflector layer can also consist of a printed layer, in particular a printed layer of metal pigments in a binder. These printed metal pigments can be applied over the entire surface or partially. In this case, the layer thickness of the first reflector layer and/or the second reflector layer is in a range of 0.1 µm to 3 µm.

It is also possible to produce the first reflector layer and/or the second reflector layer from a lacquer with electrically conductive, metallic pigments, in particular by printing and/or pouring it on.

Preferably, the second reflector layer may be present in the α range and the β range. Furthermore, the first reflector layer may be present in the α range and not in the β range. Furthermore, the first reflector layer and/or the second reflector layer may also be present in the ε range.

The absorber layer is a semi-transparent layer that reflects and/or absorbs a certain proportion of the incident light.

The remaining light passes through this layer. The absorber layer preferably has a transmission in the range of 20% to 70%.

The absorber layer is preferably a metal layer. In particular, the absorber layer comprises a material or combination of materials selected from: chromium, iron, tin, gold, copper, aluminum, titanium, silicon, and/or alloys thereof. Compounds such as nickel-chromium-iron or rarer metals such as vanadium, palladium, or molybdenum can also be used as the material of the absorber layer. Other suitable materials include nickel, cobalt, tungsten, niobium, aluminum, metal compounds such as metal fluorides, oxides, sulfides, nitrides, carbides, phosphides, selenides, silicides, and compounds thereof, as well as carbon, germanium, cermet, iron oxide, and the like. Furthermore, it is possible to use metallic pigments or dyes, in particular perylene dyes and aniline black, for this purpose.

It is preferably provided that the absorber layer has a layer thickness in the range of 4 nm to 20 nm.

Preferably, the absorber layer is present in the α-range and β-range.

The first dielectric layer and/or the second dielectric layer preferably act as spacer layers in the thin-film structure. Thus, the thicknesses and materials of the two dielectric layers largely determine the generated color of the thin-film structure.

It is preferably provided that the first predetermined thickness of the first dielectric layer is in the range from 0.1 µm to 1.0 µm, in particular from 0.05 µm to 0.80 µm, and/or that the second predetermined thickness of the second dielectric layer is in the range from 0.1 µm to 1.0 µm, in particular from 0.05 µm to 0.80 µm, in particular wherein the first predetermined thickness and/or the second predetermined thickness have a variance of less than 10% of the thickness.

Furthermore, it can be provided that the first dielectric layer and/or the second dielectric layer comprises a material or a combination of materials selected from: SiO ₂ , SiO _x , ZnS, Al ₂ O ₃ , TiO ₂ , Nb ₂ O ₅ and/or MgO.

Preferably, the first dielectric layer and/or the second dielectric layer are applied using vacuum coating technologies. These are preferably physical vapor deposition (PVD) or chemical vapor deposition (CVD). Furthermore, it is also possible to apply the first dielectric layer and/or the second dielectric layer using a printing process, wherein the coatings used comprise a binder or combination of binders selected from: polyacrylates, polyurethanes, epoxies, polyesters, polyvinyl chlorides, rubber polymers, ethylene-acrylic acid copolymers, ethylene-vinyl acetates, polyvinyl acetates, styrene block copolymers, phenol-formaldehyde resins, melamines, alkenes, allyl ethers, vinyl acetate, alkyl vinyl ethers, conjugated dienes, styrene, and acrylates.

In general, the first dielectric layer and/or the second dielectric layer are transparent or translucent, the latter being realized via the fillers described above.

It may also be possible to apply the first dielectric layer and/or the second dielectric layer using a printing process. The use of a printed, polymer-based dielectric layer also offers the advantage that it can be provided with a translucent color via fillers, which can influence the resulting color shift effect.

Preferably, the at least one primer is an adhesive that preferably increases or improves adhesion to other layers, for example, to the substrate to which the multilayer body is to be applied.

The at least one primer used may preferably comprise one or more adhesives selected from: single-layer adhesive, multi-layer adhesive, water-based adhesive, solvent-based adhesive, solvent-free adhesive, radiation-curing adhesive, thermally activatable adhesive, thermally curable adhesive or combinations thereof.

It is particularly provided that the at least one primer is applied by means of a printing process and/or by pouring and/or by doctoring. It is further advantageous if the at least one primer is applied at least partially, preferably over the entire surface. The layer thickness of the individual adhesive layers within the primer is between 0.01 µm and 8 µm, preferably between 0.05 µm and 5 µm. In particular, it is provided that the adhesive layer or layers comprise at least one binder selected from: polyacrylates, polyurethanes, epoxies, polyesters, polyvinyl chlorides, rubber polymers, ethylene-acrylic acid copolymers, ethylene-vinyl acetates, polyvinyl acetates, styrene block copolymers, phenol-formaldehyde resin adhesives, melamines, alkenes, allyl ethers, vinyl acetate, alkyl vinyl ethers, conjugated dienes, styrene, acrylates and/or combinations thereof.

It is further preferred that the lacquer from which the adhesive layer is produced by an application process comprises at least one solvent selected from: water, aliphatic (gasoline) hydrocarbons, cycloaliphatic hydrocarbons, terpene hydrocarbons, aromatic (benzene) hydrocarbons, chlorinated hydrocarbons, esters, ketones, alcohols, glycols, glycol ethers, glycol ether acetates, and/or combinations thereof. This solvent or solvent mixture is largely removed again during the application process.

It is also possible for the at least one primer or adhesive to contain at least one additive selected from: hardeners, crosslinkers, photoinitiators, fillers, stabilizers, inhibitors, corrosion inhibitors, additives such as flow control additives, defoamers, deaerators, dispersing additives, wetting agents, lubricants, matting agents, rheology additives, pigments, anticorrosive pigments, dyes, waxes, and/or combinations thereof. By appropriately selecting fillers or waxes, the tackiness of the at least one primer at room temperature can be reduced, for example.

In particular, a thermally activatable adhesive and/or an adhesive comprising thermoplastic and/or UV-based raw materials has a solids content in the range of 10% to 100%, preferably 15% to 35%. This allows for high-quality application on the coating machine. It is also preferred that the adhesive has a non-sticky surface after drying, particularly at room temperature. It is also advantageous to select the raw materials of the adhesive such that the processing temperature during production of the multilayer body is always above the glass transition temperature and below the melting point of the adhesive.

A multi-layer adhesive offers the particular advantage of being able to achieve excellent adhesion even between very demanding surfaces. Furthermore, a multi-layer structure enables primer systems that can meet a wide range of chemical and physical resistance requirements. Chemical resistance refers to the adhesive layer's resistance to the effects of chemicals. The composition of the adhesive layers is preferably selected to ensure sufficient resistance to predefined chemicals. Furthermore, it is advantageous for multi-layer adhesives to provide intermediate adhesion between the individual layers. This is achieved by appropriately selecting the adhesive components.

In particular, it is possible that the first color shift effect, in particular in the α range, generates a first color dependent on the viewing angle and/or exposure angle on the basis of interference during exposure and the second color shift effect, in particular in the β range, generates a second color dependent on the viewing angle and/or exposure angle on the basis of interference during exposure.

Furthermore, it can be provided that in the α range the first color, in particular the first color shift effect, is generated on the basis of a first optical thickness of the first dielectric layer, in particular wherein the first optical thickness is calculated from the product of the first predetermined thickness and the refractive index of the first dielectric layer.

It may also be possible that in the β range the second color, in particular the second color shift effect, is generated on the basis of a second optical thickness from the sum of the first dielectric layer and the second dielectric layer, in particular wherein the second optical thickness is calculated from the sum of the products of the first predetermined thickness with the refractive index of the first dielectric layer and the second predetermined thickness with the refractive index of the second dielectric layer.

Advantageously, the difference between the first optical thickness in the α range and the second optical thickness in the β range is at least 30 nm, preferably at least 45 nm. This difference in optical thickness enables a color difference perceptible to the human eye. This ensures that the two color-shift effects are easily identifiable.

wobei insbesondere „ΔL“ der Helligkeitsunterschied ist, der Wert „Δa“ der Farbunterschied auf der Rot-Grün-Achse und „Δb“ der Farbunterschied auf der Gelb-Blau-Achse von zwei Farben ist. Allgemein gilt insbesondere: Je kleiner der Wert ΔE, desto geringer sind die Farbunterschiede. Ein für das menschliche Auge wahrnehmbarer Farbunterschied weist bevorzugt mindestens einen Wert für ΔE von 5 und weiter bevorzugt von mindestens 10 auf.The color difference is preferably determined in the CIELAB color space by the overall color balance ΔE. According to the CIELAB system, the color space is represented by a sphere, which is defined by the three axes: brightness L, red-green axis a, and yellow-blue axis b. In particular, L = 100 corresponds to white, L = 0 to black, and L = 50 to the achromatic point. The color difference ΔE is therefore a measure of the perceived color difference between two color coordinates p = (L _p , a _p , b _p ) and v = (L _v , a _v , b _v ) and, as described above, depends on the optical thickness of the dielectric layers in the α-range and β-range. Here, L _p,v is the brightness, a _p,v the color value on the red-green axis, and b _p,v the color value on the yellow-blue axis of the two color coordinates. The color deviation ΔE _pv between two color coordinates is calculated as follows: $$\Delta E_{pv}=\sqrt{\Delta L^2-\Delta a^2-\Delta b^2}=\sqrt{{\left(L_p-L_v\right)}^2+{\left(a_p-a_v\right)}^2+{\left(b_p-b_v\right)}^2},$$

where, in particular, "ΔL" is the brightness difference, the value "Δa" is the color difference on the red-green axis, and "Δb" is the color difference on the yellow-blue axis of two colors. In general, the following applies in particular: the smaller the value ΔE, the smaller the color differences. A color difference perceptible to the human eye preferably has a value for ΔE of at least 5 and more preferably of at least 10.

As mentioned above, in variant I), it is preferably provided that the first reflector layer is structured or partially removed, in particular in the β-range. This can essentially be done by photolithography, etching, or lift-off.

• - Aufbringen einer Fotolackschicht, insbesondere vollflächiges Aufbringen der Fotolackschicht;
• - Belichtung und Entwicklung der Fotolackschicht mit einer Belichtungsmaske, bevorzugt im β-Bereich, insbesondere im Register zur Replikation;
• - Entfernen der ersten Reflektorschicht, insbesondere mittels Ätzen, im β-Bereich und Entfernen der Fotolackschicht.

Preferably, it can be provided that in variant I) for the partial removal of the first reflector layer, the following steps are carried out, in particular wherein the steps are carried out after step d) and before step e):

• - applying a photoresist layer, in particular applying the photoresist layer over the entire surface;
• - exposure and development of the photoresist layer with an exposure mask, preferably in the β-range, in particular in register for replication;
• - Removing the first reflector layer, in particular by etching, in the β-range and removing the photoresist layer.

This preferably provides a multi-layer body in which the first reflector layer is present in the α range and not present in the β range. In the α range, the first color-shift effect arises from interference of the incident light, which is partially reflected by the absorber layer, and the light that passes through the absorber layer, passes through the first dielectric layer, is reflected by the first reflector layer, passes again through the first dielectric layer, and passes through the absorber layer again. The color perceivable by the human eye is primarily determined by the first predetermined thickness d ₁ of the first dielectric layer.

Since the first reflector layer is not present in the β-region, but a second reflector layer is located behind the second dielectric layer, especially when viewed from the front, the light has a total layer thickness d ₂ , which is the additive result of the first predetermined thickness d ₁ of the first dielectric layer and the second predetermined thickness d ₃ of the second dielectric layer. Advantageously, the first dielectric layer and the second dielectric layer comprise the same material. In this case, the two dielectric layers arranged directly above one another in the β-region act like a common dielectric layer. Due to the greater layer thickness in the β-region, a different Color impression or color shift effect than in the α range. Preferably, a second color shift effect is generated in the β range, which is different from the first color shift effect in the α range.

The photoresist layer preferably comprises a positive photoresist. A positive photoresist is characterized by its increasing solubility upon activation by exposure.

In particular, a positive photoresist is characterized by the fact that, upon sufficient exposure to a suitable wavelength, such as UV radiation, this photoresist becomes soluble in a specific solvent, for example in acidic or basic aqueous solutions, in the exposed areas.

A positive photoresist preferably comprises, for example, condensation polymer of m- and p-cresol and formaldehyde (novolak resin), diazonaphthoquinone derivative (DNQ) and solvent or solvent mixture, such as, for example, 1-methoxy-2-propyl acetate.

Exposing the photoresist layer in the β-range thus increases its solubility. The photoresist layer can be removed in this β-range after exposure using a solvent. This means that the first reflector layer is now preferably exposed in the β-range and is covered by the photoresist layer in the α-range. During the subsequent removal of the first reflector layer, in particular by etching with a suitable etchant, the photoresist layer preferably acts as an etching resist in the α-range, so that the first reflector layer in the α-range cannot be attacked by the etchant. In the β-range, however, the first reflector layer is exposed and can be etched away or removed there using the etchant in the β-range.

• - zumindest partielles Aufbringen eines waschbaren Lift-Off-Lacks, vorzugsweise in einem ε-Bereich, insbesondere mittels Druckens, bevorzugt gepassert zur Replikation, wobei der Schritt nach dem Schritt a) und vor dem Schritt b) durchgeführt wird;
• - Entfernen des Lift-Off-Lackes mit einem Lösungsmittel in einem Waschprozess, um die Absorberschicht, die erste dielektrische Schicht und die erste Reflektorschicht zu entfernen, insbesondere im ε-Bereich zu entfernen, wobei der Schritt nach dem Schritt d) und vor dem Schritt e) durchgeführt wird.

Furthermore, in variant I) the following steps may be carried out to partially remove the first reflector layer:

• - at least partial application of a washable lift-off varnish, preferably in an ε-area, in particular by means of printing, preferably registered for replication, wherein the step is carried out after step a) and before step b);
• - removing the lift-off varnish with a solvent in a washing process in order to remove the absorber layer, the first dielectric layer and the first reflector layer, in particular in the ε-region, wherein the step is carried out after step d) and before step e).

This method can be used to provide a multilayer body which has an ε-region in which the second reflector layer and the second dielectric layer are present. However, no color-shift effect is generated in this ε-region due to the missing absorber layer. Rather, it is possible for structure-based, optically variable structures to be molded over the entire area or partially in at least one ε-region, which preferably generate optically variable effects. In this case, it can preferably be provided that structures are molded into the replication layer of the precursor material or of the multilayer body, which structures are transferred into the second dielectric layer when it is applied. This can also be referred to as a security feature with optically metallic-looking regions.

In particular, it is provided that the at least one ε-region is present at least in certain regions, in particular wherein the ε-region completely encloses the α-region and the β-region. By completely enclosing the α-region and the β-region by the ε-region, a multilayer body can be provided in which the two color-shift effects are present alongside metallic regions.

However, it is also conceivable that the ε-region separates the α-region from the β-region or vice versa.

It is also conceivable that the multi-layer body has at least one ε-region in which the first reflector layer and/or the second reflector layer is present.

Lift-off is preferably a formulation in which the resulting layer is either inherently soluble in a washing medium or can be made soluble or insoluble by an external influence and is capable of removing overlying layers and exposing underlying layers through the dissolution process. Activation or deactivation via an external influence can also be spatially resolved. Washing media that can be used include water, aqueous solutions of salts, organic solvents, alkalis, bases, or mixtures thereof. External influences can include electromagnetic radiation, pressure, temperature, alkalis, acids, or a chemical crosslinker.

Lift-off processes are used in particular for the production of metallic microstructures. In the lift-off process, a washcoat in the form of a desired design is applied and then overlaid or covered with at least one further layer, in particular a metallization or another lacquer. In this case, this can be all layers of the thin-film structure, for example the absorber layer, the first dielectric layer, the first reflector layer, the second dielectric layer and/or the second reflector layer. By means of a solvent treatment, the washcoat can then be removed again together with parts of the further layer(s), so that the further layer(s) only remain where no washcoat or lift-off lacquer was previously applied.

Water, ethanol and/or isopropanol can be used as solvents.

To provide a print as a wash varnish or lift-off varnish, an ink is provided in particular which contains polyvinylpyrrolidone and/or methylcellulose.

The lift-off process is also suitable for preventing the formation of flakes. Flakes generally form during embossing at the edge of the applied multilayer body or film. Using the lift-off process, the desired design elements of the multilayer body can be exposed within the layer structure using appropriate process steps by removing the first dielectric layer and/or the second dielectric layer and/or the absorber layer and/or the first reflector layer and/or the second reflector layer. In particular, the lift-off process typically makes it possible to create more detailed outline shapes than with an embossing process.

• - zumindest partielles Aufbringen eines waschbaren Lift-Off-Lacks, vorzugsweise im ε-Bereich, insbesondere mittels Druckens, bevorzugt gepassert zur Replikation, wobei der Schritt nach dem Schritt a) und vor dem Schritt b) durchgeführt wird;
• - Entfernen des Lift-Off-Lackes mit einem Lösungsmittel in einem Waschprozess, um die Absorberschicht zu entfernen, insbesondere im ε-Bereich zu entfernen, wobei der Schritt nach dem Schritt b) und vor dem Schritt c) durchgeführt wird.

It may also be possible that the following steps are carried out in variant I):

• - at least partial application of a washable lift-off varnish, preferably in the ε-range, in particular by means of printing, preferably registered for replication, wherein the step is carried out after step a) and before step b);
• - removing the lift-off varnish with a solvent in a washing process to remove the absorber layer, in particular in the ε-range, wherein the step is carried out after step b) and before step c).

Furthermore, the exposure of the photoresist for structuring the first reflector layer in the β-range can optionally be carried out in register with the lift-off resist.

Using this method, a multilayer body can be provided that has the first dielectric layer, the first reflector layer, the second dielectric layer, and the second reflector layer in an ε-region. Here, too, no color-shift effect is generated in the ε-region because the absorber layer is not present in the ε-region. Thus, an optically metallic region is preferably generated in the ε-region, which preferably encloses the α-region and the β-region. However, it may also be possible for the optically metallic ε-region to separate the α-region from the β-region.

• - zumindest partielles Aufbringen eines waschbaren Lift-Off-Lacks, vorzugsweise im ε-Bereich, insbesondere mittels Druckens, bevorzugt gepassert zur Replikation, wobei der Schritt nach dem Schritt a) und vor dem Schritt b) durchgeführt wird;
• - Entfernen des Lift-Off-Lackes mit einem Lösungsmittel in einem Waschprozess, um die Absorberschicht zu entfernen, insbesondere im ε-Bereich zu entfernen, wobei der Schritt nach dem Schritt b) und vor dem Schritt c) durchgeführt wird;
• - Aufbringen einer Fotolackschicht, insbesondere vollflächiges Aufbringen der Fotolackschicht, wobei der Schritt nach dem Schritt d) durchgeführt wird;
• - Erste Belichtung und Entwicklung der Fotolackschicht mit der Absorberschicht als erste Belichtungsmaske, bevorzugt im ε-Bereich, und zweite Belichtung mit einer zweiten Belichtungsmaske, insbesondere externen Belichtungsmaske, bevorzugt im β-Bereich, insbesondere im Register zur Replikation;
• - Entfernen der ersten Reflektorschicht, insbesondere mittels Ätzen, im ß-Bereich und ε-Bereich und Entfernen der Fotolackschicht, wobei der Schritt vor dem Schritt e) durchgeführt.

In particular, it may be possible that the following steps are carried out in variant I):

• - at least partial application of a washable lift-off varnish, preferably in the ε-range, in particular by means of printing, preferably registered for replication, wherein the step is carried out after step a) and before step b);
• - removing the lift-off varnish with a solvent in a washing process in order to remove the absorber layer, in particular in the ε-range, wherein the step is carried out after step b) and before step c);
• - applying a photoresist layer, in particular applying the photoresist layer over the entire surface, the step being carried out after step d);
• - First exposure and development of the photoresist layer with the absorber layer as a first exposure mask, preferably in the ε-range, and second exposure with a second exposure mask, in particular an external exposure mask, preferably in the β-range, in particular in register for replication;
• - removing the first reflector layer, in particular by etching, in the ß-range and ε-range and removing the photoresist layer, wherein the step is carried out before step e).

This method preferably provides a multilayer body, wherein the multilayer body has an ε-region in which the first dielectric layer, the second dielectric layer, and the second reflector layer are present. Due to the lack of an absorber layer in the ε-region, this multilayer body also does not generate a color-shift effect. Rather, it can also be a security element that has optically metallic-looking regions, preferably with structure-based optically variable effects.

• - zumindest partielles Aufbringen eines waschbaren Lift-Off-Lacks, vorzugsweise im ε-Bereich, insbesondere mittels Druckens, bevorzugt gepassert zur Replikation, wobei der Schritt nach dem Schritt a) und vor dem Schritt b) durchgeführt wird;
• - Entfernen des Lift-Off-Lackes mit einem Lösungsmittel in einem Waschprozess, um die Absorberschicht und die erste dielektrische Schicht zu entfernen, insbesondere im ε-Bereich zu entfernen, wobei der Schritt nach dem Schritt c) und vor dem Schritt d) durchgeführt wird,
• - Aufbringen einer Fotolackschicht, insbesondere vollflächiges Aufbringen der Fotolackschicht, wobei der Schritt nach dem Schritt d) durchgeführt wird;
• - Erste Belichtung und Entwicklung der Fotolackschicht mit der Absorberschicht als erste Belichtungsmaske, insbesondere im ε-Bereich, und zweite Belichtung mit einer zweiten Belichtungsmaske, insbesondere externen Belichtungsmaske, bevorzugt im β-Bereich, insbesondere im Register zur Replikation;
• - Entfernen der ersten Reflektorschicht, insbesondere mittels Ätzen, im β-Bereich und im ε-Bereich und Entfernen der Fotolackschicht, wobei der Schritt vor dem Schritt e) durchgeführt.

Furthermore, it may also be provided that the following steps are carried out in variant I):

• - at least partial application of a washable lift-off varnish, preferably in the ε-range, in particular by means of printing, preferably registered for replication, wherein the step is carried out after step a) and before step b);
• - removing the lift-off varnish with a solvent in a washing process to remove the absorber layer and the first dielectric layer, in particular in the ε-region, wherein the step is carried out after step c) and before step d),
• - applying a photoresist layer, in particular applying the photoresist layer over the entire surface, the step being carried out after step d);
• - First exposure and development of the photoresist layer with the absorber layer as a first exposure mask, in particular in the ε-range, and second exposure with a second exposure mask, in particular an external exposure mask, preferably in the β-range, in particular in the register for replication;
• - removing the first reflector layer, in particular by etching, in the β-region and in the ε-region and removing the photoresist layer, wherein the step is carried out before step e).

By means of this method, a multilayer body is preferably provided, wherein the multilayer body has an ε-region in which the second dielectric layer and the second reflector layer are present. Due to the lack of an absorber layer in the ε-region, no color-shift effect is generated in this multilayer body. This multilayer body, in particular as a security element, can also be a multilayer body which has optically metallic-looking regions, preferably with structure-based optically variable effects, in particular wherein the structures are transferred into the second dielectric layer by the replication layer.

• - zumindest partielles Aufbringen eines waschbaren Lift-Off-Lacks, vorzugsweise in einem γ-Bereich, insbesondere mittels Druckens, bevorzugt gepassert zur Replikation, wobei der Schritt nach dem Schritt a) und vor dem Schritt b) durchgeführt wird;
• - Aufbringen einer Fotolackschicht, insbesondere vollflächiges Aufbringen der Fotolackschicht, wobei der Schritt nach dem Schritt d) durchgeführt wird;
• - Belichtung und Entwicklung der Fotolackschicht mittels einer Belichtungsmaske, insbesondere externen Belichtungsmaske, bevorzugt im β-Bereich, insbesondere im Register zur Replikation;
• - Entfernen der ersten Reflektorschicht, insbesondere mittels Ätzen, im β-Bereich und Entfernen der Fotolackschicht, wobei der Schritt vor dem Schritt e) durchgeführt;
• - Entfernen des Lift-Off-Lackes, insbesondere im γ-Bereich, mit einem Lösungsmittel in einem Waschprozess, um die Absorberschicht, die erste dielektrische Schicht, die erste Reflektorschicht, die zweite dielektrische Schicht und die zweite Reflektorschicht, zu entfernen, insbesondere im γ-Bereich zu entfernen, wobei der Schritt nach dem Schritt g) und vor dem Schritt f) durchgeführt wird.

In particular, it is provided that in variant I) the following steps are carried out to remove, in particular partially remove, the first reflector layer:

• - at least partial application of a washable lift-off varnish, preferably in a γ-area, in particular by means of printing, preferably registered for replication, wherein the step is carried out after step a) and before step b);
• - applying a photoresist layer, in particular applying the photoresist layer over the entire surface, the step being carried out after step d);
• - exposure and development of the photoresist layer by means of an exposure mask, in particular an external exposure mask, preferably in the β-range, in particular in the register for replication;
• - removing the first reflector layer, in particular by etching, in the β-region and removing the photoresist layer, wherein the step is carried out before step e);
• - removing the lift-off varnish, in particular in the γ-range, with a solvent in a washing process in order to remove the absorber layer, the first dielectric layer, the first reflector layer, the second dielectric layer and the second reflector layer, in particular in the γ-range, wherein the step is carried out after step g) and before step f).

By means of this method, a multilayer body is preferably provided, wherein the multilayer body has at least one γ-region in which the at least one primer is present and the first dielectric layer, the second dielectric layer, the first reflector layer, the second reflector layer, and the absorber layer are not present. Thus, no color-shift effect is present in the γ-region. Other optically variable effects are also not present in the γ-region. Rather, the γ-region can serve as a border for the α-region and/or β-region or separate the α-region from the β-region, or vice versa. It is preferably provided that the at least one γ-region completely encloses the α-region and the β-region.

• - zumindest partielles Aufbringen eines waschbaren Lift-Off-Lacks, vorzugsweise in einem δ-Bereich, insbesondere mittels Druckens, bevorzugt gepassert zur Replikation, wobei der Schritt nach dem Schritt a) und vor dem Schritt b) durchgeführt wird;
  • - Entfernen des Lift-Off-Lackes mit einem Lösungsmittel in einem Waschprozess, um die Absorberschicht partiell zu entfernen, insbesondere im δ-Bereich zu entfernen, wobei der Schritt nach dem Schritt b) und vor dem Schritt c) durchgeführt wird;
  • - Aufbringen einer Fotolackschicht, insbesondere vollflächiges Aufbringen der Fotolackschicht, wobei der Schritt nach dem Schritt d) durchgeführt wird;
  • - Erste Belichtung und Entwicklung der Fotolackschicht mit einer ersten Belichtungsmaske, vorzugsweise im β-Bereich, und zweite Belichtung mit einer zweiten Belichtungsmaske von der Vormaterialseite, wobei die Absorberschicht als zweite Belichtungsmaske fungiert und Entwicklung der Fotolackschicht, insbesondere im δ-Bereich, bevorzugt im Register zum Lift-Off-Lack und/oder zur Replikation und/oder einer beliebigen Schicht des Mehrschichtkörpers;
  • - Entfernen der ersten Reflektorschicht, insbesondere mittels Ätzen, im β-Bereich und im δ-Bereich und Entfernen der Fotolackschicht, wobei der Schritt vor dem Schritt e) durchgeführt;
  • - Aufbringen einer weiteren Fotolackschicht, insbesondere vollflächiges Aufbringen der weiteren Fotolackschicht, wobei der Schritt nach dem Schritt g) und vor dem Schritt f) durchgeführt wird;
  • - Dritte Belichtung und Entwicklung der weiteren Fotolackschicht mit der Absorberschicht als Belichtungsmaske im δ-Bereich;
  • - Entfernen der zweiten Reflektorschicht, insbesondere mittels Ätzen, im δ-Bereich, und Entfernen der weiteren Fotolackschicht, wobei der Schritt vor dem Schritt f) durchgeführt.

Preferably, the following steps can be carried out in variant I):

• - at least partial application of a washable lift-off varnish, preferably in a δ-range, in particular by means of printing, preferably registered for replication, wherein the step is carried out after step a) and before step b);
  • - removing the lift-off varnish with a solvent in a washing process in order to partially remove the absorber layer, in particular in the δ range, wherein the step is carried out after step b) and before step c);
  • - applying a photoresist layer, in particular applying the photoresist layer over the entire surface, the step being carried out after step d);
  • - First exposure and development of the photoresist layer with a first exposure mask, preferably in the β-range, and second exposure with a second exposure mask from the precursor material side, wherein the absorber layer acts as a second exposure mask and development of the photoresist layer, in particular in the δ-range, preferably in register with the lift-off resist and/or for replication and/or any layer of the multilayer body;
  • - removing the first reflector layer, in particular by etching, in the β-region and in the δ-region and removing the photoresist layer, wherein the step is carried out before step e);
  • - applying a further photoresist layer, in particular applying the further photoresist layer over the entire surface, wherein the step is carried out after step g) and before step f);
  • - Third exposure and development of the further photoresist layer with the absorber layer as exposure mask in the δ range;
  • - removing the second reflector layer, in particular by etching, in the δ range, and removing the further photoresist layer, wherein the step is carried out before step f).

The first exposure preferably takes place such that the first exposure mask is arranged on the side of the first reflector layer or the photoresist layer facing away from the precursor material. The second exposure preferably takes place such that exposure occurs through the precursor material side, with one of the layers, in particular the absorber layer, of the multilayer body preferably fulfilling the function of a second exposure mask. The third exposure preferably also takes place from the precursor material side, as is also the case with the second exposure. Here, too, it is preferred that one of the layers of the multilayer body, in particular the absorber layer, fulfills the function of a third exposure mask.

The layer of the multilayer body serving as an exposure mask, in particular the absorber layer, has a transmission of at most 20% for the exposure wavelength in the areas to be masked and a transmission of at least 50% for the exposure wavelength in the areas to be exposed. This ensures that the layer of the multilayer body serving as an exposure mask, in particular the absorber layer, is as opaque as possible for the exposure wavelength in the areas to be masked and as transparent as possible for the exposure wavelength in the areas to be exposed.

By means of this method, a multilayer body is preferably provided, wherein the multilayer body has a δ region in which the first dielectric layer and the second dielectric layer are present. This means that the absorber layer, the first reflector layer, and the second reflector layer are not present in the δ region.

It is preferably provided that in at least one δ-region, full-area or partial structure-based optically variable structures are molded in the first dielectric layer and/or second dielectric layer, which preferably generate optically variable effects. For this purpose, structures of the replication layer are preferably transferred into the first dielectric layer and/or second dielectric layer, so that the profile structure and the profile depth are also present in the first dielectric layer and/or the second dielectric layer. A color shift effect therefore does not occur in the δ-region. Furthermore, it is possible for the at least one δ-region to completely enclose the α-region and the β-region or for the at least one δ-region to separate the α-region from the β-region, or vice versa.

• - optionales Aufbringen einer Hilfsschicht, wobei der Schritt nach dem Schritt a) durchgeführt wird;
• - Aufbringen einer ersten Fotolackschicht, insbesondere vollflächiges Aufbringen der ersten Fotolackschicht, wobei der Schritt nach dem Schritt a) und vor dem Schritt b) durchgeführt wird;
• - Erste Belichtung und Entwicklung der ersten Fotolackschicht mittels einer ersten Belichtungsmaske, vorzugsweise im α-Bereich und β-Bereich, und Entfernen der belichteten Bereiche der ersten Fotolackschicht und der Hilfsschicht, insbesondere mittels Waschen, wobei der Schritt vor dem Schritt b) durchgeführt wird;
• - Zweite Belichtung und Entwicklung der noch vorhandenen Bereiche, insbesondere des δ-Bereichs, der ersten Fotolackschicht und Entfernen der belichteten Bereiche, insbesondere mittels Waschen, insbesondere im δ-Bereich, der Hilfsschicht, der ersten Fotolackschicht und der Absorberschicht, wobei der Schritt nach dem Schritt b) durchgeführt wird;
• - Aufbringen einer zweiten Fotolackschicht, insbesondere vollflächiges Aufbringen der zweiten Fotolackschicht, wobei der Schritt nach dem Schritt d) durchgeführt wird;
• - Dritte Belichtung und Entwicklung der zweiten Fotolackschicht mit einer zweiten Belichtungsmaske, insbesondere im β-Bereich, sowie vierte Belichtung und Entwicklung der zweiten Fotolackschicht von der Vormaterialseite mit der Absorberschicht als weitere Belichtungsmaske, insbesondere im δ-Bereich;
• - Entfernen der ersten Reflektorschicht, insbesondere mittels Ätzen, im β-Bereich und im δ-Bereich und Entfernen der zweiten Fotolackschicht, wobei der Schritt vor dem Schritt e) durchgeführt;
• - Aufbringen einer dritten Fotolackschicht, insbesondere vollflächiges Aufbringen der dritten Fotolackschicht, wobei der Schritt nach dem Schritt g) und vor dem Schritt f) durchgeführt wird;
• - Fünfte Belichtung und Entwicklung der dritten Fotolackschicht von der Vormaterialseite mit der Absorberschicht als Belichtungsmaske, insbesondere im δ-Bereich;
• - Entfernen der zweiten Reflektorschicht, insbesondere mittels Ätzen, insbesondere im δ-Bereich, und Entfernen der dritten Fotolackschicht, wobei der Schritt vor dem Schritt f) durchgeführt wird.

It may also be possible that in variant I) the following steps are carried out, in particular in the following order:

• - optional application of an auxiliary layer, the step being carried out after step a);
• - applying a first photoresist layer, in particular applying the first photoresist layer over the entire surface, wherein the step is carried out after step a) and before step b);
• - first exposure and development of the first photoresist layer by means of a first exposure mask, preferably in the α-range and β-range, and removal of the exposed areas of the first photoresist layer and the auxiliary layer, in particular by washing, wherein the step is carried out before step b);
• - Second exposure and development of the remaining areas, in particular the δ-area, of the first photoresist layer and removal of the exposed areas, in particular by means of washing, in particular in the δ-area, of the auxiliary layer, the first photoresist layer and the absorber layer, wherein the step is carried out after step b);
• - applying a second photoresist layer, in particular applying the second photoresist layer over the entire surface, wherein the step is carried out after step d);
• - third exposure and development of the second photoresist layer with a second exposure mask, in particular in the β-range, and fourth exposure and development of the second photoresist layer from the precursor material side with the absorber layer as a further exposure mask, in particular in the δ-range;
• - removing the first reflector layer, in particular by etching, in the β-region and in the δ-region and removing the second photoresist layer, wherein the step is carried out before step e);
• - applying a third photoresist layer, in particular applying the third photoresist layer over the entire surface, wherein the step is carried out after step g) and before step f);
• - Fifth exposure and development of the third photoresist layer from the precursor side with the absorber layer as exposure mask, especially in the δ range;
• - removing the second reflector layer, in particular by etching, in particular in the δ range, and removing the third photoresist layer, wherein the step is carried out before step f).

By means of this method, a multilayer body is preferably provided, wherein the multilayer body has a δ region in which the first dielectric layer and the second dielectric layer are present. This means that the absorber layer, the first reflector layer, and the second reflector layer are not present in the δ region. In the δ region, structures of the replication layer can be transferred into the first dielectric layer and/or the second dielectric layer, so that the profile structure and the profile depth are also present in the first dielectric layer and/or the second dielectric layer. In this way, structure-based optically variable effects can be achieved in the δ region. A color shift effect therefore does not occur in the δ region. The δ region can serve as a border for the α region and/or β region or separate the α region from the β region, or vice versa.

• - Aufbringen einer Ätzresistschicht im α-Bereich, bevorzugt gepassert zur Replikation
• - Entfernen der ersten Reflektorschicht, insbesondere mittels Ätzen, im β-Bereich
• - optional Waschen oder Entfernen der Ätzresistschicht.

In the aforementioned methods, the first reflector layer is preferably partially removed by photolithography in the β-range. However, it is also possible to remove the first reflector layer in the β-range using an etching resist instead of photolithography. It is preferably provided that, in variant I), the following steps are carried out for partially removing the first reflector layer, in particular, wherein the steps are carried out after step d) and before step e):

• - Application of an etching resist layer in the α-range, preferably registered for replication
• - Removal of the first reflector layer, in particular by etching, in the β-range
• - optional washing or removal of the etching resist layer.

In this process, the etch resist layer can also remain in the layer structure of the multilayer body. The etch resist layer is preferably a transparent layer that does not change or influence the optical appearance of the multilayer body, particularly the color shift effects.

The etch resist layer is preferably made of acrylate, polyester, epoxy, PU resins, or acrylate copolymers with a layer thickness in the range of 0.1 µm to 10 µm, preferably 0.1 µm to 5 µm. This etch resist layer protects underlying layers, preferably metals or the first reflector layer. from attack by corrosive media. When printed in the decor, areas where no etch resist was printed can be selectively removed, while the layer to be protected remains where it is protected by the etch resist.

• - zumindest partielles Aufbringen eines waschbaren Lift-Off-Lacks, vorzugsweise im ε-Bereich, insbesondere mittels Druckens, bevorzugt gepassert zur Replikation, wobei der Schritt nach dem Schritt a) und vor dem Schritt b) durchgeführt wird;
• - Entfernen des Lift-Off-Lackes mit einem Lösungsmittel in einem Waschprozess, um die Absorberschicht, die erste dielektrische Schicht, die erste Reflektorschicht und die Ätzresistschicht zu entfernen, insbesondere im ε-Bereich zu entfernen, wobei dieser Schritt vor dem Schritt e) durchgeführt wird.

Furthermore, it may preferably be possible that in variant I) the following steps are further carried out for the partial removal of the first reflector layer:

• - at least partial application of a washable lift-off varnish, preferably in the ε-range, in particular by means of printing, preferably registered for replication, wherein the step is carried out after step a) and before step b);
• - removing the lift-off resist with a solvent in a washing process to remove the absorber layer, the first dielectric layer, the first reflector layer and the etching resist layer, in particular in the ε-region, this step being carried out before step e).

This method can be used to provide a multilayer body which has an ε-region in which the second reflector layer and the second dielectric layer are present. However, no color-shift effect is generated in this ε-region due to the missing absorber layer. Rather, it is possible for structure-based, optically variable structures to be molded over the entire area or partially in at least one ε-region, which preferably generate optically variable effects. In this case, it can preferably be provided that structures are molded into the replication layer of the precursor material or of the multilayer body, which structures are transferred into the second dielectric layer when it is applied. This can also be referred to as a security feature with optically metallic-looking regions.

• - zumindest partielles Aufbringen eines waschbaren Lift-Off-Lacks, vorzugsweise in einem γ-Bereich, insbesondere mittels Druckens, bevorzugt gepassert zur Replikation, wobei der Schritt nach dem Schritt a) und vor dem Schritt b) durchgeführt wird;
• - Entfernen des Lift-Off-Lackes mit einem Lösungsmittel in einem Waschprozess, um die Absorberschicht, die erste dielektrische Schicht, die erste Reflektorschicht, die zweite dielektrische Schicht, die zweite Reflektorschicht und die Ätzresistschicht zu entfernen, insbesondere im γ-Bereich zu entfernen, wobei dieser Schritt nach dem Schritt g) und vor dem Schritt f) durchgeführt wird.

Furthermore, it is preferably provided that in variant I) the following steps are carried out for the partial removal of the first reflector layer:

• - at least partial application of a washable lift-off varnish, preferably in a γ-area, in particular by means of printing, preferably registered for replication, wherein the step is carried out after step a) and before step b);
• - removing the lift-off resist with a solvent in a washing process in order to remove the absorber layer, the first dielectric layer, the first reflector layer, the second dielectric layer, the second reflector layer and the etching resist layer, in particular in the γ-range, this step being carried out after step g) and before step f).

By means of this method, a multilayer body is preferably provided, wherein the multilayer body has a γ-region in which the absorber layer, the first dielectric layer, the first reflector layer, the second dielectric layer, and the second reflector layer are not present. Instead, the at least one primer is present in the γ-region. Thus, no color-shift effect is present in the γ-region. Other optically variable effects are also not present in the γ-region. Rather, the γ-region can serve as a border for the α-region and/or β-region or separate the α-region from the β-region, or vice versa.

The previously mentioned methods for partially removing the first reflector layer according to variant I) involved photolithography and the use of an etching resist layer. However, it is also conceivable that the first reflector layer in the β-range could be removed using a lift-off process.

• - zumindest partielles Aufbringen eines waschbaren Lift-Off-Lacks im β-Bereich, insbesondere mittels Druckens, bevorzugt gepassert zur Replikation, wobei der Schritt nach dem Schritt b) und vor dem Schritt c) durchgeführt wird;
• - Entfernen des Lift-Off-Lackes mit einem Lösungsmittel in einem Waschprozess, um die erste dielektrische Schicht und die erste Reflektorschicht im β-Bereich zu entfernen, wobei der Schritt nach dem Schritt d) und vor dem Schritt e) durchgeführt wird.

It is preferably provided that in variant I) the following steps are carried out for the partial removal of the first reflector layer:

• - at least partial application of a washable lift-off varnish in the β-range, in particular by means of printing, preferably registered for replication, wherein the step is carried out after step b) and before step c);
• - removing the lift-off resist with a solvent in a washing process to remove the first dielectric layer and the first reflector layer in the β-region, said step being carried out after step d) and before step e).

In the previously mentioned processes, process variants for the partial removal of the first reflector layer according to variant I) were presented. The same two different color shift effects as in variant I) can also be generated in variant II) by structuring the first dielectric layer there.

• - zumindest partielles Aufbringen eines waschbaren Lift-Off-Lacks im β Bereich, insbesondere mittels Druckens, bevorzugt gepassert zur Replikation, wobei der Schritt nach dem Schritt b) und vor dem Schritt c) durchgeführt wird;
• - Entfernen des Lift-Off-Lackes mit einem Lösungsmittel in einem Waschprozess, um die erste dielektrische Schicht im β-Bereich zu entfernen, wobei der Schritt nach dem Schritt c) und vor dem Schritt d) durchgeführt wird.

It is preferably provided that in variant II) the following steps are carried out to structure the first dielectric layer:

• - at least partial application of a washable lift-off varnish in the β range, in particular by means of printing, preferably registered for replication, wherein the step is carried out after step b) and before step c);
• - removing the lift-off resist with a solvent in a washing process to remove the first dielectric layer in the β-region, said step being carried out after step c) and before step d).

This method preferably provides a multilayer body without a second reflector layer. Preferably, the two different color-shift effects in the multilayer body according to variant II) are generated by structuring the first dielectric layer in the β-range. This results in dielectric spacer layers of different thicknesses in the α-range and the β-range, which, in combination with the first reflector layer, generate different color-shift effects.

In the β range, the color shift effect is caused by interference between the incident light, which is partially reflected by the absorber layer, and the light that passes through the absorber layer, passes through the second dielectric layer, is reflected by the first reflector layer, passes through the second dielectric layer, and passes through the absorber layer again. The color perceivable by the human eye is primarily determined by the second predetermined thickness d ₃ of the second dielectric layer.

In the α range, the color shift effect also arises from interference of the incident light, which is partially reflected by the absorber layer and the light that passes through the absorber layer, first passes through the first dielectric layer and then through the second dielectric layer, is reflected by the first reflector layer and passes again through the second dielectric layer and the first dielectric layer and finally passes through the absorber layer. The color perceivable by the human eye is determined by the total layer thickness d ₂ , which is the additive result of the first predetermined thickness d ₁ of the first dielectric layer and the second predetermined thickness d ₃ of the second dielectric layer. Advantageously, the first dielectric layer and the second dielectric layer comprise the same material. In this case, the two dielectric layers arranged directly above one another in the α range act like a single dielectric layer. Due to the greater layer thickness in the α range, a different color impression or color shift effect results than in the β range. Preferably, a second color shift effect is generated in the β range, which is different from the first color shift effect in the α range.

• h) zumindest partielles Aufbringen einer Farbschicht, insbesondere fotosensitiven Farbschicht.

Furthermore, it may be provided that the following step is carried out in the process:

• h) at least partial application of a layer of paint, in particular a photosensitive layer of paint.

Preferably, step h) can be provided for both variant I) and variant II).

It is preferably possible for the multilayer body to further comprise a color layer, in particular wherein the color layer is arranged in a ζ-region and/or over the entire surface. Preferably, the color layer, in particular the ζ-region, is arranged directly adjacent to or at a distance from the α-region and/or β-region. This results in a combination of a static color, caused by the color layer, next to the two regions with the two different color-shift effects. This further increases counterfeit security.

It can further also be provided that the multi-layer body has at least one ζ-region in which the first reflector layer, the second reflector layer and the absorber layer are not present, and that at least one color layer is present in the at least one ζ-region.

Advantageously, step h) can be performed after step a) or before step f). Thus, the paint layer can be applied either directly to the precursor material or before the application of at least one primer.

It can preferably be provided that the color layer is applied over the entire surface. In particular, the color layer can be applied over the entire surface or partially behind the thin-film structure. For example, the two different color-shift effects in the α-range and β-range can be backed by a color layer surrounding the α-range and β-range.

It may also be possible for the color layer, in particular the photosensitive color layer, to be applied in step h) with a thickness in the range of 0.1 µm to 5 µm.

In particular, it is provided that the ink layer, in particular the photosensitive ink layer, is applied in a ζ-region.

It is also possible for the color layer to be arranged after the primary material, in particular in the ζ range, and/or before the at least one primer, in particular in the ζ range or across the entire surface. This allows the viewer, looking from the front, to perceive the two different color shift effects in the α range and β range, which are surrounded by a static color, preferably in the ζ range. Furthermore, when looking from behind, the viewer perceives a static color across the entire surface.

The color layer preferably comprises a color varnish, which preferably contains a binder, an additive and/or fillers.

The term color layer is preferably understood to mean a special, functional layer 20 which in particular creates a color impression that can be perceived by a viewer and/or is more preferably used as a mask layer.

Color is understood in particular to mean a coloring which, with regard to transparency and/or clarity or scattering power, preferably includes crystal-clear transparent coloring, scattering-transparent coloring or opaque coloring. The color preferably occurs as the intrinsic color of a material and/or is arranged in front of a layer as an additional colored layer in the viewing direction, wherein the underlying layer is modified in its colored appearance, in particular for a viewer. The color preferably appears optically constant or invariable in its hue and/or color saturation and/or transparency under almost all, in particular all, viewing and/or illumination angles. It is also possible for the color itself to be optically variable, wherein the hue and/or color saturation and/or transparency of the color changes in particular with changing viewing and/or illumination angles.

The color layer is preferably formed as a translucent color layer, in particular as a transparent or translucent color layer. Further preferably, the color layer preferably contains an additive that preferentially absorbs light in the ultraviolet wavelength range, in particular in a wavelength range between 200 nm and 380 nm. Such UV blockers preferably enhance the function of the color layer as a mask layer. In particular, the UV blockers exhibit no or only very low absorption in the wavelength range visible to the human eye from 380 nm to 780 nm, in order, in particular, not to alter the color impression of the color layer.

Binders are preferably understood to mean polymer-based systems and their mixtures, such as polyester, polyacrylate, polymethacrylate, polyurethane, polystyrene, polybutyrate, nitrocellulose, polyvinyl chloride, ethylene vinyl acetate, their copolymers or similar polymers.

Additives are preferably understood to mean organic or inorganic substances which achieve a predetermined effect in the processing properties, for example when applying a layer of paint in the above process or when using the security element itself.

Fillers are preferably understood to mean all other materials added to a system, in particular a polymer-based system, such as silica, pigments, dyes, UV blockers (UV = UV radiation = ultraviolet radiation = electromagnetic radiation from the ultraviolet part of the spectrum of electromagnetic radiation or from one or more sub-ranges from the ultraviolet part of the spectrum of electromagnetic radiation), tracers, in particular taggants, and/or similar materials.

Dyes and/or pigments are preferably suitable as coloring substances in the color layer. Pigments are preferably practically insoluble, in particular insoluble, in the medium into which they are integrated. Dyes preferably dissolve during use and, in particular, lose their crystal and/or particle structure. Possible classes of dyes are basic dyes, fat-soluble dyes, or metal complex dyes. Possible classes of pigments are organic and inorganic pigments. Pigments are preferably composed of a single piece of material or, alternatively, have complex structures, for example as layered structures with a plurality of layers made of different materials and/or, for example, as capsules made of different materials, in particular with a core and shell.

The color of the color layer is in particular transparent or at least translucent, with the transmittance preferably being between 5% and 99%, in particular over a sub-range of the wavelength range visible to the human eye from 380 nm to 780 nm, preferably in the range from 430 nm to 690 nm. In particular, optically variable effects of the optically variable structures arranged below the color layer from the viewer's perspective can be detected.

Furthermore, it is possible for the color layer to be formed and/or consist of several different colors, wherein these preferably also include regions with color mixtures of the first and second colors, which are created by overlapping a first color layer and a second color layer and/or by rasterizing the first and second color layers. In particular, the color saturation varies in the first and/or second color layer.

The colored varnish can be mixed with at least one pigment or colorant of the colors cyan, magenta, yellow or black (CMYK = Cyan Magenta Yello Key: black as color depth) or of the colors red, green or blue (RGB), in particular to produce a subtractive mixed color.

As an alternative to mixed colors, pigments or dyes can also be used to create a special, premixed spot color or color from a special color system (e.g. RAL, HKS, Pantone), for example orange or violet.

The color layer preferably has a layer thickness in the range from 0.1 µm to 10 µm, preferably from 0.1 µm to 5 µm.

The color can be generated directly from thermochromic components. The thermochromic substance can be added to the color-imparting pigments or dyes in the paint layer, thus creating a mixed color.

The method for producing a multilayer body and the multilayer body itself provides a multilayer body, in particular a security element, which can be applied to a substrate, for example a security document or paper banknote, by embossing or lamination. Furthermore, the multilayer body, in particular the security element, can also be embedded in a window area of a security document, for example a paper banknote. Compared to conventional security elements with a simple thin-layer structure, the multilayer body, in particular the security element, with its two different color-shift effects offers the advantage that the observer can perceive a double color-shift effect, whereas only single color-shift effects are realized in the prior art. Furthermore, the two different color-shift effects increase security against counterfeiting, since the production of these two different color-shift effects requires complex structuring processes that cannot be easily imitated by counterfeiters. The multilayer body, in particular the security element, can be designed as a hot stamping foil, cold stamping foil, or laminating foil and is therefore versatile.

• 1a, b zeigen schematisch die Verfahrensschritte eines Verfahrens zur Herstellung eines Mehrschichtkörpers;
• 2 zeigt schematisch die Verfahrensschritte eines Verfahrens zur Herstellung eines Mehrschichtkörpers;
• 3a, b, c zeigen schematisch die Verfahrensschritte eines Verfahrens zur Herstellung eines Mehrschichtkörpers, insbesondere gemäß der Variante I);
• 4a, b zeigen schematisch einen Mehrschichtkörper, insbesondere hergestellt mit einem Verfahren nach den 3a, b oder c, appliziert auf einem Substrat in einer Draufsicht und in einer Schnittansicht;
• 4c zeigt schematisch einen Mehrschichtkörper, insbesondere hergestellt mit einem Verfahren nach 3c, appliziert auf einem Substrat in einer Schnittansicht, insbesondere wobei die Generierung der unterschiedlichen Farbkippeffekte dargestellt ist;
• 4d zeigt schematisch einen Mehrschichtkörper, insbesondere hergestellt mit einem Verfahren nach den 3a, b oder c, appliziert auf einem Substrat in einer Schnittansicht, insbesondere wobei die Generierung der unterschiedlichen Farbkippeffekte dargestellt ist;
• 5 zeigt schematisch die Verfahrensschritte eines Verfahrens zur Herstellung eines Mehrschichtkörpers, insbesondere gemäß der Variante II);
• 6 zeigt schematisch einen Mehrschichtkörper, insbesondere hergestellt mit einem Verfahren nach der 5, appliziert auf einem Substrat in einer Schnittansicht, insbesondere wobei die Generierung der unterschiedlichen Farbkippeffekte dargestellt ist;
• 7a, b zeigen ausgeprägte Mehrschichtkörper, insbesondere Sicherheitselemente, wobei die Bereiche unterschiedlich angeordnet sind;
• 8a, b, c zeigen schematisch einen Mehrschichtkörper appliziert auf einem Substrat in einer Draufsicht und in einer Schnittansicht;
• 9a, b zeigen ausgeprägte Mehrschichtkörper, insbesondere Sicherheitselemente, wobei die Bereiche unterschiedlich angeordnet sind;
• 10a, b zeigen schematisch die Verfahrensschritte eines Verfahrens zur Herstellung eines Mehrschichtkörpers, bevorzugt nach den 8a, b, c und 9a, b, insbesondere gemäß der Variante I);
• 11a, b, c zeigen schematisch einen Mehrschichtkörper appliziert auf einem Substrat in einer Draufsicht und in einer Schnittansicht;
• 12a, b zeigen schematisch die Verfahrensschritte eines Verfahrens zur Herstellung eines Mehrschichtkörpers, bevorzugt nach den 11a, b, c, insbesondere gemäß der Variante 1);
• 13a, b, c zeigen schematisch einen Mehrschichtkörper appliziert auf einem Substrat in einer Draufsicht und in einer Schnittansicht;
• 14a, b, c, d, e zeigen schematisch die Verfahrensschritte eines Verfahrens zur Herstellung eines Mehrschichtkörpers, bevorzugt nach den 13a, b, c, insbesondere gemäß der Variante 1);
• 15a, b, c zeigen schematisch einen Mehrschichtkörper appliziert auf einem Substrat in einer Draufsicht und in einer Schnittansicht;
• 15d zeigt einen ausgeprägten Mehrschichtkörper, insbesondere Sicherheitselement, wobei die Bereiche unterschiedlich angeordnet sind;
• 16a, b, c zeigen schematisch einen Mehrschichtkörper appliziert auf einem Substrat in einer Draufsicht und in einer Schnittansicht.

The invention is explained below using several exemplary embodiments with the aid of the accompanying drawings. The exemplary embodiments shown are therefore not to be understood as limiting.

• 1a , b show schematically the process steps of a process for producing a multi-layer body;
• 2 shows schematically the process steps of a process for producing a multi-layer body;
• 3a , b, c show schematically the process steps of a process for producing a multi-layer body, in particular according to variant I);
• 4a , b show schematically a multilayer body, in particular produced by a method according to the 3a , b or c, applied to a substrate in a plan view and in a sectional view;
• 4c shows schematically a multi-layer body, in particular produced by a method according to 3c , applied to a substrate in a sectional view, in particular showing the generation of the different color shift effects;
• 4d shows schematically a multi-layer body, in particular produced by a method according to the 3a , b or c, applied to a substrate in a sectional view, in particular showing the generation of the different color shift effects;
• 5 shows schematically the process steps of a process for producing a multi-layer body, in particular according to variant II);
• 6 shows schematically a multi-layer body, in particular produced by a method according to 5 , applied to a substrate in a sectional view, in particular showing the generation of the different color shift effects;
• 7a , b show distinct multi-layer bodies, in particular security elements, with the regions arranged differently;
• 8a , b, c schematically show a multilayer body applied on a substrate in a plan view and in a sectional view;
• 9a , b show distinct multi-layer bodies, in particular security elements, with the regions arranged differently;
• 10a , b show schematically the process steps of a process for producing a multi-layer body, preferably according to the 8a , b, c and 9a , b, in particular according to variant I);
• 11a , b, c schematically show a multilayer body applied on a substrate in a plan view and in a sectional view;
• 12a , b show schematically the process steps of a process for producing a multi-layer body, preferably according to the 11a , b, c, in particular according to variant 1);
• 13a , b, c schematically show a multilayer body applied on a substrate in a plan view and in a sectional view;
• 14a , b, c, d, e show schematically the process steps of a process for producing a multi-layer body, preferably according to the 13a , b, c, in particular according to variant 1);
• 15a , b, c schematically show a multilayer body applied on a substrate in a plan view and in a sectional view;
• 15d shows a pronounced multi-layer body, in particular a security element, wherein the regions are arranged differently;
• 16a , b, c schematically show a multilayer body applied on a substrate in a plan view and in a sectional view.

The figures illustrate various examples of embodiments of the invention. Identical or equivalent components have been provided with the same reference symbols. Where the embodiments illustrated in the figures have common features, these common features have not been described multiple times to avoid repetition. The respective differences between the embodiments are described in relation to the figures. It goes without saying that a person skilled in the art can modify individual embodiments or combine individual features of these embodiments within the scope of the claims.

In the figures, the α region is identified by the reference symbol α, the β region by the reference symbol β, the γ region by the reference symbol γ, the δ region by the reference symbol δ, the ε region by the reference symbol ε, and the ζ region by the reference symbol ζ. For better readability, the following description of the figures omits the reference symbols α, β, γ, δ, ε, and ζ for the respective regions.

1. a) Bereitstellen eines Vormaterials 1, 11
2. b) Aufbringen einer Absorberschicht 2, 12
3. c) Aufbringen einer ersten dielektrischen Schicht 3, 13 mit einer ersten vorbestimmten Dicke d₁
4. d) Aufbringen einer ersten Reflektorschicht 4, 14
5. e) Aufbringen einer zweiten dielektrischen Schicht 5, 15 mit einer zweiten vorbestimmten Dicke d₃
6. f) Aufbringen zumindest einer Grundierung 6, 17.

The 1a shows schematically the process steps of a method for producing a multi-layer body 10, in particular a security element for securing security documents, preferably designed as a hot stamping foil or cold stamping foil or laminating foil, having at least two different color shift effects perceptible to the human eye and/or a sensor. In the method according to 1a the following steps are carried out:

1. a) Provision of a raw material 1, 11
2. b) Application of an absorber layer 2, 12
3. c) Applying a first dielectric layer 3, 13 with a first predetermined thickness d ₁
4. d) Applying a first reflector layer 4, 14
5. e) Applying a second dielectric layer 5, 15 with a second predetermined thickness d ₃
6. f) Apply at least one primer 6, 17.

• - Bereitstellen eines Trägers
• - Beschichtung einer Ablöseschicht
• - Beschichtung zumindest einer Schutzlackschicht
• - Aufbringen einer Replizierschicht und optionales Einbringen von Strukturen in die Replizierschicht mittels thermischer Replikation oder UV-Replikation.

For the raw material 11 in step a), a distinction is made between a raw material 11 for a hot stamping foil and a raw material 11 for a laminating foil. For a hot stamping foil, the following steps are carried out to prepare the raw material 1, 11 in step a), particularly in the specified order:

• - Providing a carrier
• - Coating of a release layer
• - Coating of at least one protective lacquer layer
• - Application of a replication layer and optional introduction of structures into the replication layer by means of thermal replication or UV replication.

• - Bereitstellen eines Trägers
• - optionales Aufbringen einer Haftvermittlerschicht
• - Aufbringen einer Replizierschicht und optionales Einbringen von Strukturen in die Replizierschicht mittels thermischer Replikation oder UV-Replikation.

In the case of a laminating film, the following steps, in particular in the specified order, are carried out to prepare the raw material 1, 11 in step a):

• - Providing a carrier
• - optional application of an adhesion promoter layer
• - Application of a replication layer and optional introduction of structures into the replication layer by means of thermal replication or UV replication.

In the procedure according to 1a According to variant I), in order to generate the two different color shift effects, the first reflector layer 14 is removed in a β-region, so that the first reflector layer 14 is present in an α-region and not present in the β-region, so that a first color shift effect is present in the α-region and a second color shift effect is present in the β-region, wherein the first color shift effect differs from the second color shift effect.

The partial removal of the first reflector layer 14 can be carried out, for example, by means of a photoresist, an etching resist, or by lift-off. These variants are described below in the 3a , 3b and 3c described.

• a) Bereitstellen eines Vormaterials 1, 11
• b) Aufbringen einer Absorberschicht 2, 12
• c) Aufbringen einer ersten dielektrischen Schicht 3, 13 mit einer ersten vorbestimmten Dicke d₁
• e) Aufbringen einer zweiten dielektrischen Schicht 5, 15 mit einer zweiten vorbestimmten Dicke d₃
• d) Aufbringen einer ersten Reflektorschicht 4, 14
• f) Aufbringen zumindest einer Grundierung 6, 17.

In 1b schematically depicts the process steps of a method for producing a multi-layer body 10, in particular a security element for securing security documents, preferably designed as a hot stamping foil or cold stamping foil or laminating foil, having at least two different color shift effects perceptible to the human eye and/or a sensor. In the method according to 1b the following steps are carried out in the following order:

• a) Provision of a raw material 1, 11
• b) Application of an absorber layer 2, 12
• c) Applying a first dielectric layer 3, 13 with a first predetermined thickness d ₁
• e) Applying a second dielectric layer 5, 15 with a second predetermined thickness d ₃
• d) Applying a first reflector layer 4, 14
• f) Apply at least one primer 6, 17.

In the procedure according to 1b According to variant II), in order to generate the two different color shift effects, the first dielectric layer 13 is structured by means of a lift-off process, so that the first dielectric layer 13 is present in an α-region and not present in a β-region or vice versa, so that a first color shift effect is present in the α-region and a second color shift effect is present in the β-region, wherein the first color shift effect differs from the second color shift effect.

• g) Aufbringen einer zweiten Reflektorschicht 7, 16.

In 2 The process steps of a process for producing a multi-layer body 10 are shown schematically. The process is essentially the process of 1a according to variant I), but with the difference that in the procedure the following step is carried out between steps e) and f):

• g) Applying a second reflector layer 7, 16.

In the 3a The process steps of a method for producing a multi-layer body 10 are shown schematically. The method shown is an embodiment variant according to variant I), which is described, for example, in the 1a and 2 shown schematically. The arrows with the numbering in 3a illustrate the sequence of the process steps. In the process according to the 3a First, the process steps a), b), c) and d) are carried out in the order mentioned. In other words, this means that the precursor material 11 is provided first. In the second step, the absorber layer 12 is vapor-deposited. In the third step, the first dielectric layer 13 is vapor-deposited with a first predetermined thickness d ₁ and in the fourth step, the first reflector layer 14 is vapor-deposited. As described above, the first reflector layer 14 is now removed at least in some areas. This is done in the embodiment according to the 3a by means of a photoresist. In the fifth step, a photoresist layer 18 is applied, in particular applied over the entire surface, and then the photoresist layer 18 is exposed and developed using an exposure mask 19, preferably in the β-range, in particular in register for replication. Subsequently, in the sixth step, the first reflector layer 14 is etched away or removed in the β-range, and the photoresist layer 18 is removed. As a result, the first reflector layer 14 is now present in the α-range and not present in the β-range. Subsequently, in the seventh step, the second dielectric layer 15 is vapor-deposited with a second predetermined thickness d ₃ . Preferably, the second dielectric layer 15 is applied over the entire surface, so that it is present in both the α-range and the β-range. Subsequently, in the eighth step, the second reflector layer 16 is applied. In the ninth step, further functional layers 20 can optionally be applied. Finally, in the tenth step, the primer 17 is applied. The primer 17 ensures that the necessary adhesion to the substrate 30 is established after the multilayer body 10 has been applied to a substrate 30.

In 3b Another process of variant I) is shown schematically. Thus, this is also a variant of the 1a and 2 . Essentially, the procedure according to the 3b the same steps as in the procedure according to 3a carried out, but with the difference that an etching resist is used to partially remove the first reflector layer 14 in the fifth and sixth steps.

In the fifth step, an etch resist layer 21 is first applied in the α region, preferably registered for replication. Subsequently, in the sixth step, the first reflector layer 14 in the β region is etched away or removed. The etch resist layer 21 protects the underlying first reflector layer 14 from the etchant wherever the etch resist layer 21 is applied, i.e., in the entire α region. In the β region, however, the etch resist layer 21 is not present, and therefore the first reflector layer 14 in the β region can be removed. Furthermore, in the same step, the etch resist layer 21 can be washed away or removed after etching.

The following steps 7 to 10 correspond to the steps from the 3a described steps.

In 3c Another process of variant I) is shown schematically. Thus, this is also a variant of the 1a and 2 . Essentially, the procedure according to the 3c the same steps as in the procedure according to 3a or 3b carried out, but with the difference that a lift-off lacquer 22 is used to partially remove the first reflector layer 14. However, this changes the 3a and 3b the sequence of procedural steps. This is described below.

First, as in the procedures according to 3a and 3b In the first step, the pre-material 11 is provided. The second step, the application of the absorber layer 12, is also identical to the processes according to the 3a and 3b In the third step, however, a washable lift-off varnish 22 is now at least partially applied in the β-region, in particular by printing, preferably in register for replication. The lift-off varnish 22 is not applied in the α-region.

In the fourth step, the first dielectric layer 13 is deposited with a first predetermined thickness d ₁ . In the fifth step, the first reflector layer 14 is deposited. Steps 4 and 5 according to 3c are identical to steps 3 and 4 of the 3a and 3b .

Subsequently, in the sixth step, the lift-off resist 22 is removed with a solvent in a washing process in order to remove the first dielectric layer 13 and the first reflector layer 14 in the β-region.

The following steps 7 to 10 are again identical to steps 7 to 10 from the 3a and 3b .

In 4a is a schematic representation of a multi-layer body 10, in particular produced by a method according to the 3a , b or c, in a sectional view, wherein the multilayer body 10 is applied to a substrate 30. Thus, the 4a and 4b illustrated multilayer body 10 is a multilayer body 10 according to variant I). The multilayer body 10 has two different color shift effects perceptible to the human eye and/or a sensor. The first color shift effect represents the black circle minus the star shape, which is equivalent to the α range. The second color shift effect is the star, which is arranged in the β range. The arrows A and A' indicate a section, with the corresponding sectional view of the multilayer body 10 applied to the substrate 30 in 4b is shown.

The multilayer body 10 is applied to the substrate 30 such that the primer 17 is in direct contact with the substrate 30. For example, the multilayer body 10 was transferred to the substrate 30 using a circular hot stamping die. The dashed circular line illustrates the outer contour of the embossed multilayer body 10. The substrate 30 can be, for example, a paper banknote.

The multilayer body 10 has according to 4b the following layers starting from the top layer. The top layer represents the pre-material 11. The pre-material 11 can be designed differently depending on the application of the multi-layer body 10, for example as a hot stamping foil or laminating foil. 4a and 4b The multilayer body 10 shown is preferably a hot stamping foil. In this case, the precursor material 11 comprises, in particular in the following order, a carrier, a release layer, at least one protective lacquer layer and a replication layer. Optionally, structures can be introduced into the replication layer by means of thermal replication or UV replication. Since the multilayer body 10 according to the 4a and 4b is already applied to a substrate 30, the carrier of the precursor material 11 has been removed from the substrate. This means that the multilayer body 10 applied to the substrate 30 now has at least one protective lacquer layer as its uppermost layer and a replication layer underneath. The protective lacquer layer is preferably a polymeric protective lacquer layer. Furthermore, the protective lacquer layer can simultaneously fulfill the function of a replication layer.

Alternatively, when using the multilayer body 10 as a laminating film, the precursor material 11 may comprise, in particular in the following order, a carrier, an optional adhesion promoter layer, and a replication layer. Here, too, structures can optionally be incorporated into the replication layer by means of thermal replication or UV replication. Generally, when using a multilayer body 10 as a laminating film, unlike a multilayer body 10 as a hot stamping film, the carrier would remain in the layer structure and thus not be removed. In this case, the carrier itself functions as a protective lacquer layer.

An absorber layer 12, which is preferably semitransparent, is arranged beneath the protective lacquer layer and/or replication layer. For example, this can be a chromium layer with a layer thickness that results in an optical density OD of approximately 0.5.

The next layer below the absorber layer 12 is the first dielectric layer 13. The first dielectric layer 13 functions as a spacer layer and is applied, for example, by means of electron beam evaporation. Preferably, SiO ₂ with a first predetermined thickness d ₁ in the range from 150 nm to 600 nm is used as the material. In the example shown, the first certain thickness d ₁ 350 nm. A layer thickness of the first dielectric layer 13 of approximately 350 nm results in a color shift effect from green to blue in the entire three-layer structure, when viewed from 10° with a tilt around the horizontal axis of approximately 40°.

The next layer when viewed from top to bottom in the layer structure is the first reflector layer 14. The first reflector layer 14 is preferably a metal layer, which preferably comprises a material or combination of materials selected from: aluminum, chromium, copper, tin, silver, indium, nickel, iron, gold and/or an alloy of such metals. As already mentioned in the 3a to 3c As mentioned, the first reflector layer 14 is partially removed, in particular in the β-range. Thus, the first reflector layer 14 is present in the α-range and not present in the β-range. This means that in the circular region of the multi-layer body 10 according to 4a the first reflector layer 14 is present. In the embodiment shown according to the 4a and 4b the first reflector layer 14 is an opaque aluminum layer with a layer thickness in the range of 20 nm to 30 nm.

The second dielectric layer 15 with a second predetermined thickness d ₃ is arranged below the first reflector layer 14 in the α region and directly adjacent to the first dielectric layer 13 in the β region. The second dielectric layer 15 also functions as a spacer layer. The second dielectric layer 15 is preferably designed to be continuous or full-surface, i.e. applied in one process step. For example, the second dielectric layer 15 can also consist of SiO _2. However, the second dielectric layer 15 can also be a different material with a different refractive index, e.g. ZnS. SiO ₂ is an example of a low refractive index material (LRI) with a refractive index of approximately 1.46, whereas ZnS is an example of a high refractive index material (HRI) with a refractive index of approximately 2.38. The lower the refractive index of the respective dielectric layer 13, 15, the stronger the color shift effect, i.e. the more the reflection spectrum and thus the color of the multilayer body 10, in particular the security element, changes when tilted about the horizontal axis.

In the β range, the two adjacent dielectric layers 13, 15 result in a total layer thickness d ₂ = d ₁ + d ₃ and thus, in this example, an optical thickness d _opt of n _SiO2 × d ₂ , which causes the second color shift effect, which is different from the first color shift effect (n _SiO2 = refractive index of SiO ₂ ). The second predetermined thickness d ₃ of this second dielectric layer 15 is selected depending on the desired color shift effect for the β range. For example, if a color shift effect is to be achieved in the β range from red when viewed at an angle of approximately 10° to green when tilted about the horizontal axis by approximately 40°, a total layer thickness d ₂ of approximately 500 nm is required. Thus, the second predetermined thickness d ₃ of the second dielectric spacer layer d ₃ in this example is 500nm - 350nm = 150nm.

The next layer, viewed from top to bottom in the layer structure, is the second reflector layer 16. The second reflector layer 16 is also a metal layer. The second reflector layer 16 can be partially structured, but in this example, it is 4a and 4b over the entire surface. This means that the second reflector layer 16 is present in the α range and the β range. For example, the second reflector layer 16, similar to the first reflector layer 14, can again be an opaque aluminum layer with a layer thickness in the range of 20 nm to 30 nm.

Finally, the layer structure of the multi-layer body 10 has at least one primer 17, which establishes the connection to the substrate 30, for example a paper banknote.

The multilayer body 10, in particular the security element, in 4a or 4b Consequently, when viewed at an angle of approximately 10°, it displays a red star on a green background. When tilted around the horizontal axis, the appearance changes to a green star on a blue background. This is a very striking optically variable effect, which cannot be easily achieved using materials commercially available to counterfeiters, such as color-shifting inks.

4c shows in a schematic side view a multi-layer body 10 according to variant I), in particular produced by a method according to the 3a to 3c how the different color shift effects occur. In the α-range, which in this embodiment completely encloses the β-range, the color shift effect is caused by interference of the incident light, which is partially reflected by the absorber layer 12 and the light which passes through the absorber layer 12, passes through the first dielectric layer 13, is reflected by the first reflector layer 14, passes again through the first dielectric layer 13 and passes through the absorber layer 12 again. The color perceivable by the human eye is primarily determined by the first predetermined thickness d ₁ of the first dielectric layer 13.

Since the first reflector layer 14 is not present in the β-range, the light has a total layer thickness d ₂ , which is the additive result of the first predetermined thickness d ₁ of the first dielectric layer 13 and the second predetermined thickness d ₃ of the second dielectric layer 15. Since the two dielectric layers 13, 15, as already mentioned for the 4a and 4b As explained, they consist of the same material, in the β range the two dielectric layers arranged directly above each other act as a single dielectric layer. Due to the greater layer thickness in the β range, a different color impression or color shift effect results than in the α range.

It is preferably provided that the difference between the first optical thickness in the α range and the second optical thickness in the β range is at least 30 nm, preferably at least 45 nm.

4d shows in a schematic side view a further multi-layer body 10 according to variant I), in particular produced by a method according to 3c how the different color shift effects are created. The multilayer body according to 4d differs from the multilayer body according to 4c in that in the β-region not only the first reflector layer was removed, but also the first dielectric layer. Thus, the multilayer body according to 4d , unlike the multilayer bodies according to 4b or 4c , in the β-region, only the second dielectric layer acts as a spacer layer. The second reflector layer is arranged below the second dielectric layer in the β-region.

In the α range, which in this embodiment completely encloses the β range, the color shift effect arises from interference of the incident light, which is partially reflected by the absorber layer 12 and the light that passes through the absorber layer 12, passes through the first dielectric layer 13, is reflected by the first reflector layer 14, passes again through the first dielectric layer 13, and passes through the absorber layer 12 again. The color perceivable by the human eye is primarily determined by the first predetermined thickness d ₁ of the first dielectric layer 13.

In the β range, the color shift effect arises from interference of the incident light, which is partially reflected by the absorber layer 12 and the light that passes through the absorber layer 12, passes through the second dielectric layer 15, is reflected by the second reflector layer 16, passes again through the second dielectric layer 15, and passes through the absorber layer 12 again. The color perceivable by the human eye is primarily determined by the second predetermined thickness d ₃ of the second dielectric layer 15.

In this case too, it is preferably provided that the difference between the first optical thickness, in particular of the first dielectric layer 13, in the α range and the second optical thickness, in particular of the second dielectric layer 15, in the β range is at least 30 nm, preferably at least 45 nm.

In the 5 The process steps of a method for producing a multi-layer body 10 are shown schematically. The method shown is an embodiment according to variant II), which is described, for example, in the 1b shown schematically. The arrows with the numbering in 5 illustrate the sequence of the process steps. In the process according to the 5 First, process steps a) and b) are carried out in the order mentioned. In other words, this means that first the precursor material 11 is provided and in the second step the absorber layer 12 is vapor-deposited. Then, in the third step, a washable lift-off varnish 22 is at least partially applied in the β-range, in particular by printing, preferably in register for replication. The fourth step is process step c), in which the first dielectric layer 13 is vapor-deposited with a first predetermined thickness d _1. Then, in the fifth step, the lift-off varnish 22 is removed with a solvent in a washing process in order to remove the first dielectric layer 13 in the β-range. This means that after the fifth step, the first dielectric layer 13 is only present in the α-range. Then, in the sixth step, the second dielectric layer 15 is vapor-deposited with a second predetermined thickness d ₃ . Thus, in the α-range, the two dielectric layers 13, 15 are directly adjacent to each other. This means that the first dielectric layer 13 and the second dielectric layer 15 form a common spacer layer with the thickness d ₂ , which is formed from the sum of the two predetermined thicknesses d ₁ and d ₃ . Whereas in the β-range, only the second dielectric layer 15 is present and thus a spacer layer with the second predetermined Thickness d ₃ is formed. Subsequently, in the seventh step, the first reflector layer 14 is vapor-deposited. In the eighth step, additional functional layers 20 can optionally be applied. Finally, in the ninth step, at least one primer 17 is applied.

6 shows in a schematic side view a multi-layer body 10 according to variant II), in particular produced by a method according to 5 how the different color-shift effects arise. The multilayer body 10 is already applied to a substrate 30, so that the primer 17 is in direct contact with the substrate 30. For example, the multilayer body 10 was transferred to the substrate 30 using a hot stamping stamp. The substrate 30 can be, for example, a paper banknote.

The multilayer body 10 has according to 6 the following layers starting from the top layer. The top layer represents the pre-material 11. The pre-material 11 can be designed differently depending on the application of the multi-layer body 10, for example as a hot stamping foil or laminating foil. 6 The multilayer body 10 shown is preferably a hot stamping foil. In this case, the precursor material 11 comprises, in particular in the following order, a carrier, a release layer, at least one protective lacquer layer and a replication layer. Optionally, structures can be introduced into the replication layer by means of thermal replication or UV replication. Since the multilayer body 10 according to the 6 has already been applied to a substrate 30, the carrier of the precursor material 11 has been removed from it. This means that the multilayer body 10 applied to the substrate 30 now has at least one protective lacquer layer as its top layer and a replication layer underneath.

An absorber layer 12, which is preferably semitransparent, is arranged beneath the protective lacquer layer and/or replication layer. For example, this can be a chromium layer with a layer thickness that results in an optical density OD of approximately 0.5.

The next layer below the absorber layer 12 is the first dielectric layer 13. The first dielectric layer 13 functions as a spacer layer and is applied, for example, by means of electron beam evaporation. SiO ₂ with a first predetermined thickness d ₁ in the range from 150 nm to 600 nm is preferably used as the material. In the example shown, the first predetermined thickness d ₁ is 350 nm. A layer thickness of the first dielectric layer 13 of approximately 350 nm results in a color shift effect from green to blue in the entire three-layer structure, when viewed from 10° with a tilt around the horizontal axis of approximately 40°. The first dielectric layer 13 is only present in the α-range and not in the β-range, since this, as 5 described, was structured using a lift-off procedure.

The next layer below the first dielectric layer 13 is the second dielectric layer 15. This is applied over the entire surface, ie in both the α-range and the β-range. According to 6 the second dielectric layer 15 borders directly on the absorber layer 12 in the β region. In the α region, however, the second dielectric layer 15 borders on the first dielectric layer 13. The second dielectric layer 15 is arranged with a second predetermined thickness d ₃ . The second dielectric layer 15 also functions as a spacer layer. The second dielectric layer 15 is preferably designed to be continuous or full-surface, ie applied in one process step. For example, the second dielectric layer 15 can also consist of SiO ₂ . However, the second dielectric layer 15 can also be a different material with a different refractive index, e.g. ZnS. SiO ₂ is an example of a low-refractive index material (LRI) with a refractive index of approximately 1.46, whereas ZnS is an example of a high-refractive index material (HRI) with a refractive index of approximately 2.38. The lower the refractive index of the respective dielectric layer 13, 15, the stronger the color-shift effect, i.e., the more the reflection spectrum and thus the color of the multilayer body 10, in particular the security element, changes when tilted about the horizontal axis.

In the α-range, the two adjacent dielectric layers 13, 15 result in a total layer thickness d ₂ = d ₁ + d ₃ and thus, in this example, an optical thickness d _opt of n _SiO2 × d ₂ , which causes the second color shift effect, which is different from the first color shift effect. The second predetermined thickness d ₃ of this second dielectric layer 15 is selected depending on the desired color shift effect for the α-range. For example, if a color shift effect is to be achieved in the α-range from red when viewed at an angle of approximately 10° to green when tilted about the horizontal axis by approximately 40°, a total layer thickness d ₂ of approximately 500 nm is required. Thus, the second predetermined thickness d ₃ of the second dielectric layer 15 in this example is 500 nm - 350 nm = 150 nm.

The next layer, viewed from top to bottom in the layer structure, is the first reflector layer 14. The first reflector layer 14 is a metal layer. The first reflector layer 14 can be partially structured, but in this example, it is 6 However, it is present over the entire surface. This means that the first reflector layer 14 is present in the α-range and the β-range. For example, the first reflector layer 14 can be an opaque aluminum layer with a layer thickness in the range of 20 nm to 30 nm.

Finally, the layer structure of the multi-layer body 10 has at least one primer 17, which establishes the connection to the substrate 30, for example a paper banknote.

In contrast to the 4c multilayer body 10 shown, the multilayer body 10 has according to the 6 no second reflector layer 16. The two different color shift effects are 6 by structuring the first dielectric layer 13 in the β range. This results in dielectric layers of different thicknesses in the α range and the β range, which, in combination with the first reflector layer 14, generate different color shift effects.

In the β range, which in this embodiment completely encloses the α range, the color shift effect arises from interference of the incident light, which is partially reflected by the absorber layer 12 and the light that passes through the absorber layer 12, passes through the second dielectric layer 15, is reflected by the first reflector layer 14, passes again through the second dielectric layer 15, and passes through the absorber layer 12 again. The color perceivable by the human eye is primarily determined by the second predetermined thickness d ₃ of the second dielectric layer 15.

Since in the α range the color shift effect also arises from interference of the incident light, which is partially reflected by the absorber layer 12 and the light which passes through the absorber layer 12, first passes through the first dielectric layer 13 and then through the second dielectric layer 15, is reflected by the first reflector layer 14 and passes again through the second dielectric layer 15 and the first dielectric layer 13 and finally passes through the absorber layer 12. The color perceivable by the human eye results from the total layer thickness d ₂ , which is the additive result of the first predetermined thickness d ₁ of the first dielectric layer 13 and the second predetermined thickness d ₃ of the second dielectric layer 15. Since the two dielectric layers 13, 15 have the same material, in the α range the two dielectric layers arranged directly above one another act like a common dielectric layer. Due to the greater layer thickness in the α range, a different color impression or color shift effect results than in the β range.

Basically, with a multilayer body 10 according to 6 the same color shift effect as in the multilayer body 10 according to 4c achieve.

In the 4c and 6 The color shift effect was described using the example of non-transparent or opaque substrates 30 when viewed from the front in incident light. This color shift effect also applies in incident light to transparent substrates 30, e.g., transparent polymer substrates, and non-transparent substrates 30 with transparent cutouts, e.g., banknote paper with a punched or embedded window.

For clarity, only opaque and transparent substrates 30 will be referred to below. The term "transparent substrates 30" encompasses fully transparent substrates 30 and substrates 30 with transparent recesses or partial areas to which the multilayer body 10, in particular the security element, is applied.

In transmitted light when viewed from the front, opaque and transparent substrates 30 may have a weakened color impression and an increased perception of the α range and the β range as brighter and darker areas. Structures or shapes located behind the first reflector layer 14 and/or the second reflector layer 16, such as watermarks or window shapes, may become visible, which are not visible in incident light. Areas in which the first reflector layer 14 and the second reflector layer 16 are arranged may also appear darker than areas in which only the first reflector layer 14 is arranged. When viewed from behind, the optical perception of the multilayer body 10, in particular the security element, in incident light on transparent substrates 30 with a transparent primer 17 essentially corresponds to the optical impression of the second reflector layer 16, if there are no additional, e.g. colored, layers between the substrate 30 and the second reflector layer 16 and if the second reflector layer 16 is opaque. In transmitted light When viewed from behind, the color impression of opaque and transparent substrates 30 is attenuated or altered in the area with only one reflector layer. In areas with two reflector layers, the color impression is almost eliminated and merges into the perception of a dark area. If replicated relief structures are present in the thin-film structure, these are visible when viewed from the rear.

In the special case where not only the absorber layer 12 is semi-transparent, but also the first reflector layer 14, and both consist, for example, of a chromium layer of the same thickness with an optical density OD of approximately 0.5, the viewer from the rear side, i.e. when viewed from behind, also sees two areas with different color impressions and color shift effects. In the α-range, when viewed from behind, there is a color shift effect that is determined by the refractive index and the second predetermined thickness d ₃ of the second dielectric layer 15. In the β-range, however, the same color shift effect occurs as when viewed from the front. The same applies, if this special case applies, to the variants described below.

At the 4a and 4b The embodiment shown shows that after the application process, the α-region defines the edge region of the multilayer body 10, in particular the security element. However, it is also possible that neither of the regions α or β completely encloses the other, and thus the α-region and the β-region define the outer edge in some areas after the application process. This is the case, for example, in 7a The outer edge is shown with dashed lines. Such an applied multilayer body 10, in particular a security element, as in 7a shown, can only be realized by means of an embossing die provided in this specific form. The dashed lines of the 7a also show that embossing was done along these lines or edges.

In the 4a , 4b and 7a Variants are shown in which the α-area and the β-area are arranged next to each other or directly adjacent to each other. This enables a seamless transition from the α-area to the β-area and vice versa. As in 7b However, as shown, it is also possible to provide a γ-region in which the first dielectric layer 13, the second dielectric layer 15, the first reflector layer 14, the second reflector layer 16, and the absorber layer 12 are not present. This γ-region additionally optically separates the α-region and the β-region from one another. Alternatively, this can also be achieved using a suitable forming stamp, which in this example stamps the two digits 5 and 0 in register with the α-region and β-region. The dashed lines indicate that embossing took place along these edges.

Alternatively, the α region and the β region can be separate, i.e. they do not touch each other, but one of the regions still encloses the other.

For better understanding, the above-mentioned embodiments were described for variants with embossed layers from the layer stack for stamping foils, in particular a hot stamping foil. All described embodiments can also be a laminating foil, whereby the carrier is not removed during stamping and remains in the product, thus maintaining a consistent visual impression of the multilayer body 10, in particular the security element.

In 8a A multilayer body 10 is schematically shown in a plan view, wherein the multilayer body 10 is applied to a substrate 30. The multilayer body 10 is, similar to the multilayer body 10 according to the 4a , a multi-layer body 10 according to variant I). The multi-layer body 10 has two different color shift effects perceptible to the human eye and/or a sensor. The first color shift effect represents the black crescent, which is equivalent to the α range. The second color shift effect is the star minus the crescent, which is arranged in the β range. The star-shaped area completely encloses the crescent. Furthermore, in contrast to the multi-layer body 10 according to 4a , in which multilayer body 10 according to 8a A γ-area is also provided, which represents the circular area minus the star. The circular area is also created in this embodiment, similar to the embodiment according to 4a , during the transfer process using a circular embossing die. In contrast to the embodiment according to 4a , is in accordance with the execution 8a The γ-region between the circular line and the star is transparent. In this γ-region, the observer can see the underlying substrate 30 and, if present, any print on the substrate 30.

In the γ-region, which is transparent, the first dielectric layer 13 and/or the second dielectric layer 15 can also be present, provided that the first dielectric layer 13 and/or the second dielectric layer 15 is also transparent. In this figure, the focus has again been on three regions for better clarity, but more than three regions can also be present in a multi-layer body 10, in particular a security element. One, both, or all three of the regions can additionally contain structure-based effects. The same optical appearance can be achieved by structuring the first or second dielectric layer 13, 15 instead of with a partial metal layer between the two dielectric layers 13, 15, for example by means of a lift-off process of one of these layers. The materials of the various layers in this example are the same as in the previous example with the 1a to 1e .

The arrows B and B' indicate a section, with the corresponding sectional view of the multilayer body 10 applied to the substrate 30 in 8b The layer structure of the 8b The layer structure of the multilayer body 10 shown in the α-range and β-range is analogous to the layer structure of the 4b shown multilayer body 10. Thus, the multilayer body 10 has the following layers from top to bottom: precursor material 11 or protective lacquer layer and/or replication layer, absorber layer 12, first dielectric layer 13, first reflector layer 14, second dielectric layer 15, second reflector layer 16 and a primer 17.

The security element in the 8a and 8b When viewed vertically, it therefore shows a green crescent moon embedded in a red star. When tilted around the horizontal axis, the appearance changes to a blue crescent moon embedded in a green star.

In contrast to the 4a , b, c and 6 shown design variants are available in the embodiment according to the 8a , 8b and 8c γ-range, in which at least the metallic and preferably also the transparent dielectric layers are not present, so that no optical color-shift effect is generated there. In this γ-range, the layer stack can be embedded solely in the material of the primer 17. 8c shows the different regions in a schematic side view, in the case that the first dielectric layer 13, the second dielectric layer 15, the first reflector layer 14, the second reflector layer 16 and the absorber layer 12 are not present in the γ region.

8c thus shows a released multi-layer body 10, in particular a released security element, with an α-region framed over its entire area by the β-region. In the β-region, the first reflector layer 14 is not present, whereas in the α-region the first reflector layer 14 is present. In the α-region, a color-shift effect results, which is determined by the first predetermined thickness d ₁ of the first dielectric layer 13. In the β-region, a total layer thickness d ₂ results for the light, which is additively derived from the first predetermined thickness d ₁ of the first dielectric layer 13 and the second predetermined thickness d ₃ of the second dielectric layer 15. Since in this embodiment variant the two dielectric layers 13, 15 are also made of the same material, the two dielectric layers 13, 15 act like a common, uniform layer. Due to the greater layer thickness, a different color impression or color shift effect results in the β range than in the α range.

Additionally, there is the exposed γ-region, in which, in this exemplary embodiment, all layers of the thin-film structure of the multilayer body 10 have been partially removed, for example, using a lift-off process. Thus, the primer 17 in this γ-region directly borders the precursor material 11, in particular the protective lacquer layer or replication layer. Furthermore, it is also conceivable to remove only those parts of the thin film in the γ-region that are not optically transparent, such as the first reflector layer 14 and/or the second reflector layer 16 and/or the absorber layer 12.

For the observer of the multilayer body 10 applied to a security document, the γ-region appears transparent when viewed from the front, which is why the substrate 30 and any print layers present are visible here. In the case of transparent substrates 30, the γ-region also appears transparent when viewed from the rear. In reflected light, for non-transparent, opaque and transparent substrates 30, including non-transparent substrates 30 with transparent regions, the optical perception of a color impression for the α-region and a different color impression for the β-region embedded in a transparent γ-region results when viewed from the front. When viewed from the rear, the optical perception of the security feature in reflected light corresponds to the 8b shown layer structure for transparent substrates 30 with transparent primer 17 the optical impression of the second reflector layer 16 embedded in a transparent area.

In transmitted light when viewed from the front, opaque and transparent substrates 30 may have a weakened color impression and an increased perception of the α-range and β-range as brighter and darker areas. Structures or shapes located behind the first reflector layer 14 and/or second reflector layer 16 that are not visible in incident light may become visible. The α-range, in which the first reflector layer 14 and the second reflector layer 16 are arranged, appears darker than the β-range, in which only the second reflector layer 16 is arranged. When viewed from behind in transmitted light, the color impression of opaque and transparent substrates 30 is weakened or changed in the β-range with only one reflector layer. In the α-range with two reflector layers, the color impression is greatly weakened to almost extinguished, transitioning into the perception of a dark area.

The primary advantage of a multilayer body 10 provided with a γ-range, i.e. the isolation of the two color shift effects in the α-range and β-range, is that the formation of flakes, i.e. unwanted residues of the hot stamping foil, cold stamping foil or laminating foil, occurs less and fewer visible flakes are created.

In the 8a In the embodiment shown in fig. 1, b, and c, the γ region defines the edge region of the multilayer body 10, in particular the security element, after the application process. Furthermore, the α region is completely enclosed by the β region.

However, it is also possible that the α-region and the β-region are adjacent to each other, but neither region completely encloses the other, and thus the α-region and the β-region partially border on the γ-region, which completely encloses the α-region and the β-region. This is in 9a shown.

In the 8a , b, c and 9a In the embodiments shown, it is shown that the α-region and the β-region are located directly next to each other, thus enabling a seamless transition between the α-region and the β-region. However, it is also conceivable that a γ-region, in which the first dielectric layer 13, the second dielectric layer 15, the first reflector layer 14, the second reflector layer 16 and the absorber layer 12 are not present, and this γ-region thus does not allow any color shift effect, additionally optically separates the α-region and the β-region from each other. This is shown in 9b This can be achieved, for example, using a lift-off process. The circular γ-region shown in dashed lines is also created in this example during the transfer process using a circular embossing die. The dashed lines indicate that embossing occurred along these edges.

The described design variants according to the 8a , b, c, 9a and 9b can be both a stamping foil and a laminating foil, in which the carrier is not removed during embossing and remains in the multilayer body 10. The same optical color impression of the multilayer body 10, in particular the security element, is obtained for both a stamping foil and a laminating foil.

In the 10a The process steps of a method for producing a multi-layer body 10 are shown schematically. The method shown is an embodiment variant according to variant I), which is described, for example, in the 8a , b, c and 9a , b is shown schematically.

The arrows with the numbers in 10a illustrate the sequence of the process steps. For example, the process according to the 10a First, process step a), the provision of a precursor material 11, is carried out. In the second step, a washable lift-off varnish 22 is at least partially applied, preferably in a γ-region, in particular by printing, preferably registered for replication. Using the lift-off varnish 22, the subsequently applied layers in the γ-region can be removed, so that the layers in the α-region and β-region can be exposed.

The following steps 3 to 9 of the 10a are analogous to steps 2 to 8 of the procedure according to 3a . The explanations for steps 2 to 8 of the 3a apply analogously to steps 3 to 9 of the 10a . Thus, the 10a the first reflector layer 14 is removed by means of a photoresist in the β-range.

Subsequently, in the tenth step, the lift-off lacquer 22 is removed, particularly in the γ-range, with a solvent in a washing process in order to remove the absorber layer 12, the first dielectric layer 13, the first reflector layer 14, the second dielectric layer 15 and the second reflector layer 16, particularly in the γ-range. In this way, all the Lift-off lacquer 22 applied layers are removed wherever the lift-off lacquer 22 was applied. Thus, the α-region and the β-region can be exposed and multilayer body 10 can be produced according to the 8a , b, c and 9a , b can be produced.

Finally, in the eleventh step, additional functional layers 20 are applied. However, this step is optional. In the twelfth step, at least one primer 17 is applied, which establishes contact with the substrate 30 after the multilayer body 10 has been applied to it.

In 10b is a similar procedure as in 10a shown, with which a multilayer body 10 according to the 8a , b, c and 9a , b can be produced. However, the process according to the 10b the partial removal of the first reflector layer 14 by means of an etching resist.

Thus, in the procedure according to 10b the process steps 1, 2, 10, 11 and 12 are the same as in the process according to 10a Whereas steps 3 to 9 of the 10b analogous to steps 2 to 8 of the procedure according to 3b The explanations for steps 2 to 8 of the 3b apply analogously to steps 3 to 9 of the 10b . Thus, the 10b The first reflector layer 14 is removed using an etching resist in the β range. The etching resist preferably remains in the layer structure and is preferably transparent.

In 11a A multilayer body 10 is schematically shown in a plan view, wherein the multilayer body 10 is applied to a transparent substrate 30. The multilayer body 10 is, similar to the multilayer body 10 according to the 4a , a multi-layer body 10 according to variant I). The multi-layer body 10 has two different color shift effects perceptible to the human eye and/or a sensor. The first color shift effect represents the black crescent, which is equivalent to the α range. The second color shift effect is the star minus the crescent, which is arranged in the β range. The star-shaped area and the crescent overlap. Furthermore, in contrast to the multi-layer body 10 according to 4a , in which multilayer body 10 according to 11a A δ-area is also provided, which represents the circular area minus the star and the crescent. The circular area is also created in this embodiment, similar to the embodiment according to 4a , during the transfer process using a circular embossing die. In contrast to the embodiment according to 4a , is in accordance with the execution 11a the δ-area between the circle line and the star and the crescent moon is transparent, which additionally generates optically variable effects.

The δ-range thus represents an additional security feature in which the two color shift effects in the α-range and β-range are integrated.

The arrows C and C' indicate a section, with the corresponding sectional view of the multilayer body 10 applied to the substrate 30 in 11b The layer structure of the 11b The layer structure of the multilayer body 10 shown in the α-range and β-range is analogous to the layer structure of the 4b shown multilayer body 10. Thus, the multilayer body 10 has the following layers from top to bottom: precursor material 11 or protective lacquer layer and/or replication layer, absorber layer 12, first dielectric layer 13, first reflector layer 14, second dielectric layer 15, second reflector layer 16 and a primer 17.

At the 11b In the illustrated embodiment, the protective coating layer is a polymeric protective coating. This protective coating layer can also serve as a replication layer. Structure-based effects are molded into this layer using a relief structure.

The absorber layer 12 is preferably a semitransparent layer, e.g., a chromium layer with a layer thickness that results in an optical density OD of approximately 0.5. The absorber layer 12 can be structured, for example, using a lift-off process.

The first dielectric layer 13 can, for example, be an SiO ₂ layer with a first predetermined thickness d ₁ of 400 nm. Thus, the first dielectric layer 13 is a low-refractive-index layer with a low refraction index (LRI). Preferably, the first dielectric layer 13 is applied over the entire surface. This means that the first dielectric layer 13 is also present in the δ range.

The first reflector layer 14 is partially structured and is present in the α range and absent in the β range. The first reflector layer 14 is preferably an opaque aluminum layer with a thickness in the range of 20 nm to 30 nm.

The second dielectric layer 15 is also present over the entire surface, i.e., in the α-range, β-range, and δ-range. In the α-range, the second dielectric layer 15 borders the first reflector layer 14. In the β-range and δ-range, the second dielectric layer 15 borders directly the first dielectric layer 13. The second dielectric layer 15 has a second predetermined thickness d ₃ , which is, for example, 60 nm. The second dielectric layer 15 is preferably made of a high-refractive index material (HRI), such as ZnS.

aus der Summe der ersten vorbestimmten Dicke d₁ und der zweiten vorbestimmten Dicke d₃ bestimmt. Zur Berechnung der optischen Dicke der Gesamtschicht werden jeweils die Dicken der einzelnen Schichten mit dem Brechungsindex des verwendeten Materials multipliziert und schließlich die Produkte aufaddiert. Die in diesem Ausführungsbeispiel im β-Bereich resultierende optische Dicke d_opt berechnet sich folgendermaßen: $${\text{d}}_{\text{opt}}={\text{n}}_{\text{LRI}}\ast {\text{d}}_1+{\text{n}}_{\text{HRI}}\ast {\text{d}}_3={\text{n}}_{\text{SiO2}}\ast {\text{d}}_1+{\text{n}}_{\text{ZnS}}\ast {\text{d}}_3$$

In the β-range, the two adjacent dielectric layers 13, 15 result in a total layer thickness d ₂ , which is calculated according to the formula $${\text{d}}_{}$$$${}_2={\text{<figure-callout id="1" label="d" filenames="DE102023128009A1\_0006.png,DE102023128009A1\_0022.png" state="{{state}}">d</figure-callout>}}_1+{\text{<figure-callout id="3" label="d" filenames="DE102023128009A1\_0006.png,DE102023128009A1\_0007.png" state="{{state}}">d</figure-callout>}}_3$$

determined from the sum of the first predetermined thickness d ₁ and the second predetermined thickness d ₃ . To calculate the optical thickness of the total layer, the thicknesses of the individual layers are multiplied by the refractive index of the material used, and the products are then added together. The resulting optical thickness d _opt in the β range in this embodiment is calculated as follows: $${\text{d}}_{\text{opt}}={\text{n}}_{\text{LRI}}\ast {\text{<figure-callout id="1" label="d" filenames="DE102023128009A1\_0006.png,DE102023128009A1\_0022.png" state="{{state}}">d</figure-callout>}}_1+{\text{n}}_{\text{HRI}}\ast {\text{<figure-callout id="3" label="d" filenames="DE102023128009A1\_0006.png,DE102023128009A1\_0007.png" state="{{state}}">d</figure-callout>}}_3={\text{n}}_{\text{SiO2}}\ast {\text{<figure-callout id="1" label="d" filenames="DE102023128009A1\_0006.png,DE102023128009A1\_0022.png" state="{{state}}">d</figure-callout>}}_1+{\text{n}}_{\text{ZnS}}\ast {\text{<figure-callout id="3" label="d" filenames="DE102023128009A1\_0006.png,DE102023128009A1\_0007.png" state="{{state}}">d</figure-callout>}}_3$$

This optical thickness causes the second color shift effect in the β range, which is different from the first color shift effect in the α range.

The second reflector layer 16 is also partially structured and is present only in the α and β ranges. The second reflector layer 16 is not present in the δ range. As with the first reflector layer 14, the second reflector layer 16 can be an aluminum layer with a thickness of 20 nm to 30 nm.

In addition to the two different color shift effects in the α-range and β-range, which can additionally have structure-based optically variable effects, the multilayer body 10 contains 11c Structure-based effects in the δ range that are transparent. For this purpose, structures are preferably molded in the protective lacquer layer and/or replication layer in the δ range, which structures are at least partially, preferably largely, retained in their structural depth and profile shape when the first dielectric layer 13 and/or second dielectric layer 15 is applied, in particular by means of PVD (= Physical Vapor Deposition). As a result, the molded structures are also present at the interface between the first dielectric layer 13 and the second dielectric layer 15, which, due to the different refractive indices of the two layers, enables the structure-based, optically variable effects. Examples of transparent, structure-based, optically variable effects in the δ range include color effects in direct reflection based on subwavelength gratings, achromatic design elements that appear to protrude curvedly from the surface of the multilayer body 10, or diffractive fine-line transformations or movement effects. The second predetermined thickness d ₃ of the second reflector layer 16, which in the embodiment according to the 11c is highly refractive, is preferably in a range of 30 nm to 150 nm, in particular from 40 nm to 80 nm, for the efficient generation of the above-mentioned effects.

The viewer of the 11a , b and c, when viewed from the front in reflected light, two different color shift effects are seen in the α-range and in the β-range, surrounded by a transparent δ-range which contains full-surface or partially structure-based optically variable effects. In the transparent δ-range, the substrate 30 and any print layers applied to the substrate 30 are visible. In transmitted light when viewed from the front, opaque and transparent substrates 30 may have a weakened color impression and an increased perception of the α-range and β-range as lighter and darker areas. In this case, structures or prints located behind the reflector layers which are not visible in reflected light may become visible. The α-range, in which two reflector layers are present, appears darker than the β-range, in which only the second reflector layer 16 is present.

In the case of transparent substrates 30 with a transparent primer 17, the optical perception of the multilayer body 10, in particular the security element, when viewed from behind in incident light corresponds to the optical impression of the second reflector layer 16 embedded in a transparent δ-region, which contains full-surface or partial structure-based optically variable effects. In transmitted light, when the viewer is looking from behind, the color impression of opaque and transparent substrates 30 is attenuated or changed in the β range, in which only the second reflector layer 16 is present. In the α range, in which the first reflector layer 14 and the second reflector layer 16 are present, the color impression is very strongly attenuated to almost extinguished, and merges into the perception of a dark area. In the transparent δ range, full-surface or partial structure-based optically variable effects are visible.

In the 12a The process steps of a method for producing a multi-layer body 10 are shown schematically. The method shown is an embodiment variant according to variant I), which is described, for example, in the 11a , b and c. The arrows with the numbering in 12a illustrate the sequence of the process steps. For example, the process according to the 12a First, process step a), the provision of a precursor material 11, is carried out. In the second step, a washable lift-off varnish 22 is at least partially applied, preferably in a δ range, in particular by printing, preferably registered for replication.

In the third step, process step b), i.e., the application of an absorber layer 12, is performed. Subsequently, in the fourth step, the lift-off varnish 22 is removed with a solvent in a washing process to partially remove the absorber layer 12 in the δ range. Thus, after the fourth step, the absorber layer 12 is only present in the α and β ranges. Therefore, the absorber layer 12 is not present in the δ range.

Subsequently, in the fifth step, process step c), i.e., the application of the first dielectric layer 13 with a predetermined thickness d _{1 ,} is carried out. Preferably, structures are molded in the precursor material 11 or in the protective lacquer layer or in the replication layer, the profile shape and structure depth of which are transferred to the first dielectric layer 13 in the δ range. In the sixth step, process step d), i.e., the application of the first reflector layer 14, is carried out.

Subsequently, in the seventh step, a photoresist layer 18 is applied, in particular applied over the entire surface. In the eighth step, a first exposure and development of the photoresist layer 18 takes place using a first exposure mask 19, preferably in the β range, and a second exposure using a second exposure mask from the precursor side, with the absorber layer 12 acting as the second exposure mask, and development of the photoresist layer 18, in particular in the δ range, preferably in register with the lift-off resist 22 and/or for replication and/or any layer of the multilayer body.

Furthermore, in the eighth step, the first reflector layer 14 is removed in the β-region and in the δ-region, in particular by means of etching, and the photoresist layer 18 is removed. Thus, after the eighth step, the first reflector layer 14 is only present in the α-region.

Subsequently, in the ninth step, process step e), i.e., the application of the second dielectric layer 15 with a predetermined thickness d _3, is carried out. Preferably, structures are molded in the precursor material 11 or in the protective lacquer layer or in the replication layer, the profile shape and structure depth of which are transferred to the second dielectric layer 15 in the δ range.

In the tenth step, process step g) takes place, i.e., the application of the second reflector layer 16. Subsequently, in the eleventh step, a further photoresist layer 18 is applied, in particular, the full-surface application of the further photoresist layer 18. In the twelfth step, a third exposure and development of the further photoresist layer 18 takes place with the absorber layer 12 as an exposure mask 19 in the δ range. Subsequently, the second reflector layer 16 is etched away or removed in the δ range, and the further photoresist layer 18 is removed from the layer structure.

Subsequently, in a twelfth step, additional functional layers 20 can optionally be applied. Finally, in the 13th step, at least one primer 17 is applied.

In 12b is an alternative embodiment of a method for producing a multi-layer body 10, in particular according to the 11a , b and c. The steps 7 to 16 of the method according to 12b identical to steps 4 to 13 of the procedure according to 12a . The statements made there also apply analogously to the procedure according to 12b The following are the provisions of the procedure 12a different steps 1 to 6 are explained.

In the first step, the procedure according to 12b a precursor material 11 is provided. Subsequently, in the second step, an auxiliary layer 23 is optionally applied. The auxiliary layer 23 serves to protect the precursor material 11 from the solvent-based photoresist. Furthermore, the auxiliary layer 23 allows for better control of the subsequent washing process, for example, by enhancing contrast.

In the third step, a first photoresist layer 18 is applied, in particular the first photoresist layer 18 is applied over the entire surface. Subsequently, in the fourth step, a first exposure and development of the first photoresist layer 18 takes place by means of a first exposure mask 19, preferably in the α-range and β-range, and removal of the exposed areas of the first photoresist layer 18 and the auxiliary layer 23 by means of washing.

In the fifth step, process step b) is carried out, i.e. the application of the absorber layer 12. In this case, the absorber layer 12 is applied directly to the precursor material 11 in the α-range and β-range and to the first photoresist layer 18 still present there in the δ-range.

In the sixth step, a second exposure and development of the remaining areas, in particular the δ-region, of the first photoresist layer 18, and removal of the exposed areas, in particular by washing, especially in the δ-region, of the auxiliary layer 23, the first photoresist layer 18, and the absorber layer, takes place. This step removes the absorber layer 12 in the δ-region, so that the absorber layer 12 is only present in the α-region and β-region.

The following are the already known steps from the procedure according to the 12a .

In 13a A multilayer body 10 is schematically shown in a plan view, wherein the multilayer body 10 is applied to a transparent substrate 30. The multilayer body 10 is, similar to the multilayer body 10 according to the 4a , a multi-layer body 10 according to variant I). The multi-layer body 10 has two different color shift effects perceptible to the human eye and/or a sensor. The first color shift effect represents the black crescent, which is equivalent to the α range. The second color shift effect is the star minus the crescent, which is arranged in the β range. The star-shaped area and the crescent overlap. Furthermore, in contrast to the multi-layer body 10 according to 4a , in which multilayer body 10 according to 13a An ε-area is also provided, which represents the circular area minus the star, the crescent moon, and the numbers "5" and "0." The second reflector layer 16 is also present in this ε-area. The observer perceives a metallic optical impression in the ε-area. The circular area is also created in this embodiment, similar to the embodiment according to 4a , during the transfer process by means of a circular embossing die. Furthermore, the embodiment according to 13a the two digits "5" and "0," which are arranged in the δ region. The δ region is a region in which the absorber layer 12, first reflector layer 14, and second reflector layer 16 are not present, but in which the first dielectric layer 13 and second dielectric layer 15 are present. Thus, the δ region is transparent, and the viewer can perceive the substrate 30 or a security print applied to the substrate 30, for example, a UV print, through the δ region.

In an alternative embodiment, it may be possible for the second reflector layer 16 to be present over the entire surface, so that no δ-region is present. Furthermore, the transparent δ-region and the metallic ε-region may have structure-based optically variable effects over the entire surface or partially.

The arrows D and D' indicate a section, with the corresponding sectional view of the multilayer body 10 applied to the substrate 30 in 13b The layer structure of the 13b The layer structure of the multilayer body 10 shown in the α-range and β-range is analogous to the layer structure of the 4b shown multi-layer body 10. Thus, the multi-layer body 10 has the following layers from top to bottom: precursor material 11 or protective lacquer layer and/or replication layer, absorber layer 12, first dielectric layer 13, first reflector layer 14, second dielectric layer 15, second reflector layer 16 and a primer 17. Furthermore, in the 13c illustrates the allocation of the individual areas.

In the version according to the 13a , b and c have the first dielectric layer 13 and the second dielectric layer 15 as material SiO ₂ .

When viewed from the front, the observer sees the first color shift effect in the crescent-shaped α range in reflected light and the second color shift effect, which is different from the first color shift effect, in the star-shaped β range. In addition, structure-based, metallized optically variable effects can be seen in the ε range. These effects are realized, for example, by means of an aluminum layer as the second reflector layer 16 in combination with replication structures that are incorporated into the protective lacquer layer or the replication layer and transferred into the two dielectric layers 13, 15 when they are applied. In the δ range, the second reflector layer 16 is left out and is therefore not present, which on the one hand makes design elements such as the two digits "5" and "0" recognizable. On the other hand, the second reflector layer 16 as well as the first reflector layer 14 and/or the absorber layer 12 are not present in the pronounced edge region, which reduces so-called flake formation and makes the product more visually appealing.

Design elements can be present in the form of printed layers and/or structure-based optically variable effects in both the inner and the edge δ-regions. In transmitted light when viewed from the front, opaque and transparent substrates 30 can result in a weakened color impression and an increased perception of the β-region and α-region as lighter and darker regions, respectively. In this case, structures or prints located behind the first reflector layer 14 and/or second reflector layer 16 can become visible, which are not visible in incident light. The α-region with the first reflector layer 14 and the second reflector layer 16 appears darker than the β-region, in which only the second reflector layer 16 is present.

When viewed from the rear, the viewer's optical perception of transparent substrates 30 with a transparent primer 17 without additional layers between the substrate 30 and the second reflector layer 16 in the α-range, β-range and ε-range in reflected light corresponds to the optical impression of the second reflector layer 16. In transmitted light when viewed from the rear, the color impression of opaque and transparent substrates in the β-range with only one reflector layer is weakened or changed. In the α-range with the first reflector layer 14 and the second reflector layer 16, the color impression is very strongly weakened to the point of being almost extinguished and changes into the perception of a dark area. In the transparent δ-range, the design elements such as the two digits "5" and "0" can be seen mirrored compared to the front, both in reflected and transmitted light.

In the versions according to the 13a , b and c show variants in which the α region and the β region are adjacent to each other without one region completely enclosing the other, so that both regions are at least partially adjacent to the ε region and a seamless transition is provided between the α region and the β region. In an alternative embodiment, it is also possible for the α region and/or the β region to be at least partially adjacent to the δ region.

Furthermore, it is possible that the α-region or the β-region completely encloses the other region, so that the completely enclosed region does not border on the δ-region and/or ε-region.

It is also possible that the γ-region and/or the δ-region and/or the ε-region separate the α-region and the β-region.

In the 14a The process steps of a method for producing a multi-layer body 10 are shown schematically. The method shown is an embodiment variant according to variant I), which is described, for example, in the 13a , b and c. The arrows with the numbering in 14a illustrate the sequence of the process steps. For example, the process according to the 12a First, process step a), the provision of a precursor material 11, is carried out. In the second step, a washable lift-off varnish 22 is at least partially applied, preferably in an ε-region, in particular by printing, preferably registered for replication.

Subsequently, in the third step, process step b), the application of an absorber layer 12 takes place. This is done in the process according to 14a over the entire surface, i.e. in the α-range, the β-range, and the ε-range. In the fourth step, process step c) takes place, i.e. the application of the first dielectric layer 13 with a first predetermined thickness d ₁ . This layer is also applied over the entire surface. Subsequently, in the fifth step, process step d) takes place, the application of the first reflector layer 14. This also takes place over the entire surface.

Subsequently, in the sixth step, a photoresist layer 18 is applied over the entire surface. In the seventh step, the photoresist layer 18 is exposed in the β-range using an exposure mask 19, and the first reflector layer 14 arranged beneath the photoresist layer is subsequently etched away or removed in the β-range to pattern the first reflector layer 14. The photoresist layer 18 is subsequently removed from the layer structure.

In the eighth step, the lift-off varnish 22 is removed with a solvent in a washing process to remove the absorber layer 12, the first dielectric layer 13, and the first reflector layer 14 in the ε-region. This means that after step 8, only the precursor material 11 remains in the ε-region.

In the ninth step, the second dielectric layer 15 is subsequently vapor-deposited over the entire surface with a second predetermined thickness d ₃ . This means that the second dielectric layer 15 is applied in the α region, the β region, and the ε region. Subsequently, in the tenth step, the second reflector layer 16 is applied, also over the entire surface. In the eleventh step, additional functional layers 20 can optionally be applied, before at least one primer 17 is applied in the twelfth step.

With the procedure according to 14a a multilayer body 10 is obtained which has the second dielectric layer 15 and the second reflector layer 16 in the ε-region.

In the 14b The process steps of a further process for producing a multi-layer body 10 are shown schematically. The process shown is an embodiment variant according to variant I), which is described, for example, in the 13a , b and c. The method according to 14b represents an alternative to the procedure under the 14a The main difference is that in the procedure according to 14b for structuring the first reflector layer 14 in the β-range, an etching resist instead of a photoresist, as in the method according to 14a is the case.

The arrows with the numbers in 14b illustrate the sequence of the process steps. For example, the process according to the 14b First, process step a), the provision of a precursor material 11, is carried out. In the second step, a washable lift-off varnish 22 is at least partially applied, preferably in an ε-area, in particular by means of printing, preferably registered for replication. The following steps 3 to 5 are identical to steps 3 to 5 according to the 14a .

Subsequently, in the sixth step, an etching resist layer 21 is applied in the α-region and ε-region, but not in the β-region. Thus, the etching resist layer 21 has a gap in the β-region. During the subsequent etching in step 7, the first reflector layer 14 can be patterned through this gap.

The following steps 8 to 12 are identical to steps 8 to 12 according to the 14a However, compared to the procedure under 14 the difference is that in the procedure according to 14b the etching resist layer 21 remains in the layer structure.

With the procedure according to 14b a multilayer body 10 is obtained which has the second dielectric layer 15 and the second reflector layer 16 in the ε-region.

In the 14c The process steps of a further process for producing a multi-layer body 10 are shown schematically. The process shown is an embodiment variant according to variant I), which is described, for example, in the 13a , b and c. The method according to 14c represents an alternative to the procedure under the 14a The main difference is that in the procedure according to 14c the lift-off varnish 22 is removed in the fourth step and not as in the process according to 14a in the eighth step. In general, this results in a 14a shown multilayer body 10 different layer structure achieved.

The arrows with the numbers in 14c illustrate the sequence of the process steps. For example, the process according to the 14c First, process step a), the provision of a precursor material 11, is carried out. In the second step, a washable lift-off varnish 22 is at least partially applied, preferably in an ε-region, in particular by printing, preferably registered for replication.

Subsequently, in the third step, process step b), the application of an absorber layer 12 takes place. This is done in the process according to 14c full-surface, i.e. in the α-range, the β-range and the ε-range.

Subsequently, in the fourth step, the lift-off varnish 22 is removed with a solvent in a washing process to remove the absorber layer 12 in the ε-range. After step 4, the absorber layer 12 is thus only present in the α-range and β-range.

In the fifth step, process step c) is carried out, i.e., the application of the first dielectric layer 13 with a first predetermined thickness d ₁ . This layer is also applied over the entire surface. Subsequently, in the sixth step, process step d) is carried out, the application of the first reflector layer 14. This is also applied over the entire surface.

Subsequently, in the seventh step, a photoresist layer 18 is applied over the entire surface. In the eighth step, the photoresist layer 18 is subsequently exposed in the β-range using an exposure mask 19, and the first reflector layer 14 arranged beneath the photoresist layer is subsequently etched away or removed in the β-range to pattern the first reflector layer 14. The photoresist layer 18 is then removed from the layer structure.

The next steps 9 to 12 are analogous to the procedure according to the 14a .

With the procedure according to 14c a multilayer body 10 is obtained which has the first dielectric layer 13, the first reflector layer 14, the second dielectric layer 15 and the second reflector layer 16 in the ε-region.

In the 14d The process steps of a further process for producing a multi-layer body 10 are shown schematically. The process shown is an embodiment variant according to variant I), which is described, for example, in the 13a , b and c. The method according to 14c provides, among other things, an alternative to the procedure under the 14c The main difference is that in the procedure according to 14d the first reflector layer 14 is also removed in the ε-range, whereas in the method according to 14c the first reflector layer 14 is present in the ε-range. In general, this results in a 14c shown multilayer body 10 different layer structure achieved.

The arrows with the numbers in 14d illustrate the sequence of the procedural steps. Steps 1 to 7 of the 14d are identical to steps 1 to 7 according to the 14c . The statements made there also apply analogously to the 14d .

In the eighth step, the procedure according to 14d , unlike the procedures under 14c , a first exposure and development of the photoresist layer 18 with the absorber layer 12 as the first exposure mask 19 is carried out in the ε-range. Subsequently, a second exposure is carried out with a second exposure mask 19, in particular an external exposure mask 19, in the β-range. The first reflector layer 14 is then removed in the β-range and ε-range by etching and thus structured, and the photoresist layer 18 is subsequently removed. As a result, the first reflector layer 14 is only present in the α-range.

The following steps 9 to 12 are again identical to the procedure according to 14c . The statements made there also apply analogously to the 14d .

With the procedure according to 14d a multilayer body 10 is obtained which has the first dielectric layer 13, the second dielectric layer 15 and the second reflector layer 16 in the ε-region.

In the 14e The process steps of a further process for producing a multi-layer body 10 are shown schematically. The process shown is an embodiment variant according to variant I), which is described, for example, in the 13a , b and c. The method according to 14c provides, among other things, an alternative to the procedure under the 14c or 14d The main difference is that in the procedure according to 14e the first dielectric layer 13 and the first reflector layer 14 are also removed in the ε-range. For this purpose, the lift-off lacquer 22 is removed differently than in the processes according to the 14c and 14d only removed in the fifth step. In general, this results in a signal in the ε-domain that is 14c or 14d shown multilayer body 10 different layer structure achieved.

The arrows with the numbers in 14e illustrate the sequence of the process steps. For example, the process according to the 14e First, process step a), the provision of a precursor material 11, is carried out. In the second step, a washable lift-off varnish 22 is at least partially applied, preferably in an ε-region, in particular by printing, preferably registered for replication.

Subsequently, in the third step, process step b), the application of an absorber layer 12 takes place. This is done in the process according to 14e full-surface, i.e. in the α-range, the β-range and the ε-range.

In the fourth step, process step c) is carried out, i.e., the application of the first dielectric layer 13 with a first predetermined thickness d ₁ . This layer is also applied over the entire surface.

Subsequently, in the fifth step, the lift-off resist 22 is removed with a solvent in a washing process to remove the first dielectric layer 13 and the absorber layer 12 in the ε-range. After step 5, the absorber layer 12 and the first dielectric layer 13 are thus only present in the α-range and β-range.

Subsequently, in the sixth step, process step d), the application of the first reflector layer 14 takes place. This is also carried out over the entire surface.

In the seventh step, a photoresist layer 18 is applied over the entire surface. Subsequently, in the eighth step, the first exposure and development of the photoresist layer 18 takes place with the absorber layer 12 as the first exposure mask 19 in the ε-range. Subsequently, a second exposure takes place with a second exposure mask 19, in particular an external exposure mask 19, in the β-range. At the end of the eighth step, the first reflector layer 14 is etched away or removed in the β-range and the ε-range, and finally the photoresist layer 18 is removed.

The following steps 9 to 12 are again identical to the procedure according to 14c or according to 14d . The statements made there also apply analogously to the 14e .

With the procedure according to 14e a multilayer body 10 is obtained which has the second dielectric layer 15 and the second reflector layer 16 in the ε-region.

All presented procedures according to the 14a to 14e have in common that at least one of the two reflector layers is present in the ε-range. Thus, a metallization is realized in the ε-range in which no color-shift effect occurs. Preferably, it is a metallized security feature in which the two color-shift effects in the α-range and β-range are embedded.

In 15a A multilayer body 10 is schematically shown in a plan view, wherein the multilayer body 10 is applied to a transparent substrate 30. The multilayer body 10 is, similar to the multilayer body 10 according to the 4a , a multi-layer body 10 according to variant I). The multi-layer body 10 has two different color shift effects that are perceptible to the human eye and/or a sensor. The first color shift effect represents the black crescent, which is equivalent to the α range. The second color shift effect is the star minus the crescent, which is arranged in the β range. The crescent is completely enclosed by the star. Furthermore, in contrast to the multi-layer body 10 according to 4a , in which multilayer body 10 according to 15a A ζ-region is also provided, which represents the circular region minus the star. In this ζ-region, the absorber layer 12, the first reflector layer 14, the second reflector layer 16, the first dielectric layer 13, and the second dielectric layer 15 are not present. Instead, at least one color layer 24 and the primer 17 are present in the ζ-region. The viewer perceives a static color, for example "red," in the ζ-region. The combination of a static color in the ζ-region directly next to or closely adjacent to the α-region and/or β-region with color-shift effects enables easily explainable effects in the multi-layer body 10, in particular the security element, thereby further increasing security against counterfeiting. The color layer 24 can, for example, be printed.

The circular area is also created in this embodiment, similar to the embodiment according to 4a , during the transfer process by means of a circular embossing die. Furthermore, the embodiment according to 15a an edge region equivalent to the γ region. The γ region is a region where the absorber layer 12, the first dielectric layer 13, the first reflector layer 14, the second dielectric layer 15, and the second reflector layer 16 are not present. Instead, the primer 17 is present in the γ region.

The arrows E and E' indicate a section, with the corresponding sectional view of the multilayer body 10 applied to the substrate 30 in 15b The layer structure of the 15b The layer structure of the multilayer body 10 shown in the α-range and β-range is analogous to the layer structure of the 4b shown multilayer body 10, but with the difference that a color layer 24 is additionally arranged below the second reflector layer 16. Thus, the multilayer body 10 has the following layers from top to bottom: precursor material 11 or protective lacquer layer and/or replication layer, absorber layer 12, first dielectric layer 13, first reflector layer 14, second dielectric layer 15, second reflector layer 16, color layer 24 and a primer 17. Furthermore, in the 15c illustrates the allocation of the individual areas.

The ink layer 24 in the ζ-region can also be designed so that no γ-region is present, or a γ-region separates the β-region from the ζ-region. In this exemplary embodiment, this ink layer 24 is in direct contact with the protective lacquer layer or replication layer of the precursor material 11. Alternatively, one or more transparent lacquer layers can be arranged in between, e.g., primer layers for increasing the adhesive force.

As in the 15b and 15c As can be seen, in the α-range and β-range the color layer 24 lies behind the thin-film structure for the viewer, whereby the color layer 24 is not visible when viewed from the front.

A further embodiment with a static color layer 24 in combination with the two color shift effects can be realized if the two color shift effects do not completely adjoin each other. In the embodiment according to the 15a , 15b and 15c the α-area is not adjacent to the color layer 24 at all, since the α-area is completely enclosed by the β-area.

Such a design variant is in 15d shown. Here, the α-region and the β-region are completely separated from each other. The β-region encloses the α-region, but the ζ-region with at least one color layer 24 is provided between the β-region and the α-region.

Furthermore, it is possible for the α region and the β region to be adjacent to each other without one region completely enclosing the other, so that both regions are at least partially adjacent to the ζ region. It is also conceivable for the α region and the β region to be completely separated from each other without one region completely enclosing the other, with the ζ region located between and around the α region and the β region. The α region and the β region can also be separated from the ζ region by a non-colored γ region.

The optical perception of the α-range and the β-range of the 15a , b and c corresponds to the perception of the image in 8a to 8c shown variant. In the α range, the observer perceives a different color shift effect than in the β range. In addition, at least one other static color is visible in the ζ range, which can differ from the color impressions or color shift effects of the α range and the β range, or can be visually very similar or identical to the color impression of one of the two ranges.

In transmitted light when viewed from the front, opaque and transparent substrates 30 may experience a weakened color impression in the α and β ranges, while the α and β ranges may be perceived as brighter and darker regions, respectively, in an intensified manner. Structures or prints located behind the first reflector layer 14 and/or the second reflector layer 16 that are not visible in reflected light may become visible. The α range with two reflector layers appears darker than the β range with only one reflector layer. In the ζ range, the static color impression is retained even in transmitted light.

When viewed from the rear, the optical perception of transparent substrates 30 with transparent primer 17 without additional layers between substrate 30 and second reflector layer 16 in the α-range and β-range in incident light corresponds to the optical impression of the second reflector layer 16, if it is not covered with the color layer 24. If the color layer 24 also covers the second reflector layer 16, the optical perception of all areas covered with this color layer 24 corresponds to the optical impression of the color layer 24. In transmitted light when viewed from behind, the color impression of opaque and transparent substrates 30 is weakened or changed in the β range, in which only the second reflector layer 16 is arranged. In the α range, in which the first reflector layer 14 and the second reflector layer 16 are arranged, the color impression is very strongly weakened to almost extinguished and changes into the perception of a dark area. If the α range and the β range are additionally covered with the color layer 24, the optical perception corresponds to the optical impression of the color layer 24.

All described variants of the multi-layer body 10 for the described layer structure with color layer 24 according to the 15a to 15d can be either an embossing foil or a laminating foil, where the carrier is not removed during embossing and remains in the product. The same optical color impression of the multilayer body 10, in particular of the security element, is obtained for both the embossing foil and the laminating foil.

In a further embodiment, it is also possible that structure-based optically variable effects are integrated into the two color shift effects, in particular in the α-range and/or β-range.

In 16a A multilayer body 10 is schematically shown in a plan view, wherein the multilayer body 10 is applied to a substrate 30. The multilayer body 10 is, similar to the multilayer body 10 according to the 4a , a multi-layer body 10 according to variant I). The multi-layer body 10 has two different color shift effects perceptible to the human eye and/or a sensor. The first color shift effect represents the black crescent, which is equivalent to the α range. The second color shift effect is the star minus the crescent, which is arranged in the β range. The star-shaped area completely encloses the crescent. Furthermore, in contrast to the multi-layer body 10 according to 4a , in which multilayer body 10 according to 16a A γ-area is also provided, which represents the circular area minus the star. The circular area is also created in this embodiment, similar to the embodiment according to 4a , during the transfer process using a circular embossing die. In contrast to the embodiment according to 4a , is in accordance with the execution 16a the γ-area between the circle and the star is transparent. The observer can see the underlying substrate 30 in this γ-area and, if applicable, a print on the substrate 30. Furthermore, in the embodiment according to 16a The first dielectric layer 13 has an optically variable structure that produces corresponding optically variable effects. These optically variable effects are perceptible in the α-range, i.e., the moon-shaped range, in addition to the color shift effect.

The arrows F and F' indicate a section, with the corresponding sectional view of the multilayer body 10 applied to the substrate 30 in 16b The layer structure of the 18b The layer structure of the multilayer body 10 shown in the α-range and β-range is analogous to the layer structure of the 4b shown multilayer body 10. Thus, the multilayer body 10 has the following layers from top to bottom: precursor material 11 or protective lacquer layer and/or replication layer, absorber layer 12, first dielectric layer 13, first reflector layer 14, second dielectric layer 15, second reflector layer 16 and a primer 17.

The absorber layer 12 is, for example, a semitransparent chromium layer with a layer thickness corresponding to an optical density OD of approximately 0.3 to 0.5. The absorber layer 12 can be structured, for example, using a lift-off process. However, the absorber layer 12 can also be present over the entire surface, unlike the example shown here.

The first dielectric layer 13 comprises, for example, a polymer layer into which optically variable structures are introduced over the entire surface or partially, in particular by means of thermal or UV replication.

The first reflector layer 14 is present only in the α range and not in the β range. For example, the first reflector layer 14 can be an opaque aluminum layer with a layer thickness in the range of 20 nm to 30 nm.

welche den zweiten Farbkippeffekt bewirkt.The first reflector layer 14 defines the α-region with the first predetermined thickness d ₁ of the first dielectric layer 13, thereby generating the first color shift effect. Below the first Reflector layer 14, i.e., in the α range, as well as in the β range directly adjacent to the first dielectric layer 13, is followed by the second dielectric layer 15 with a second predetermined thickness of d ₃ . The second dielectric layer 15 is preferably present continuously. This means that the second dielectric layer 15 is applied in one process step. Furthermore, the second dielectric layer 15 can be made of the same material as the first dielectric layer 13, for example SiO ₂ . In the β range, the adjacent dielectric layers 13, 15 result in a total layer thickness d ₂ = d ₁ + d ₃ and thus, in this example, an optical thickness d _opt of: $${\text{d}}_{\text{opt}}={\text{n}}_{\text{LRI}}\ast {\text{<figure-callout id="1" label="d" filenames="DE102023128009A1\_0006.png,DE102023128009A1\_0022.png" state="{{state}}">d</figure-callout>}}_1+{\text{n}}_{\text{HRI}}\ast {\text{<figure-callout id="3" label="d" filenames="DE102023128009A1\_0006.png,DE102023128009A1\_0007.png" state="{{state}}">d</figure-callout>}}_3={\text{<figure-callout id="1" label="n DL" filenames="DE102023128009A1\_0006.png,DE102023128009A1\_0022.png" state="{{state}}">n</figure-callout>}}_{\text{DL}}\ast {\text{<figure-callout id="1" label="d" filenames="DE102023128009A1\_0006.png,DE102023128009A1\_0022.png" state="{{state}}">d</figure-callout>}}_1+{\text{<figure-callout id="2" label="n SiO" filenames="DE102023128009A1\_0006.png,DE102023128009A1\_0007.png" state="{{state}}">n</figure-callout>}}_{\text{SiO}}\ast {\text{<figure-callout id="3" label="d" filenames="DE102023128009A1\_0006.png,DE102023128009A1\_0007.png" state="{{state}}">d</figure-callout>}}_3$$

which causes the second color shift effect.

In this example, the second reflector layer 16 is partially structured and present only in the α-range and the β-range, whereas the second reflector layer 16 is not present in the γ-range. The second reflector layer 16 can, for example, be an opaque aluminum layer with a thickness in the range of 20 nm to 40 nm. The primer 17 enables the connection to the substrate 30, for example, banknote paper, and is preferably transparent.

The 16a and 16b show a multilayer body 10 that has two different color shift effects in the α-range and the β-range, which are embedded in a γ-range. In 16c The arrangement of the regions is illustrated again. Preferably, the γ-region is free-standing and transparent. 16a to 16c The multilayer body 10 shown differs from the previous multilayer bodies 10 in that it additionally contains, in at least one color-shift effect, an optically variable element which is molded into the first dielectric layer 13 or the second dielectric layer 15. This makes it possible for the viewer to perceive, in addition to the different color-change effects defined by the layer thicknesses d ₁ and d ₂ , additional color effects and design elements which are based on the structures introduced into the first dielectric layer 13 and/or the second dielectric layer 15.

In further embodiments, it is also possible for the second dielectric layer 15 to comprise structure-based optically variable structures instead of the first dielectric layer 13. Furthermore, it is also possible for the first dielectric layer 13 and the second dielectric layer 15 each to have structure-based optically variable effects. In this case, effects and design elements are possible which, from the viewer's perspective, overlap, complement one another visually and/or in terms of content, or are located next to one another. In particular, it is possible to create a perfect register of the structure-based optically variable effects in the β range with the second color shift effect in the β range, since the structure-based optically variable effects in the second dielectric layer 15 in the α range are concealed by the first reflector layer 14 when viewed from the front and are therefore not visible from the front.

When viewed from the front, the viewer sees the 16a to 16c illustrated multi-layer body 10, in particular security element, in reflected light with opaque, opaque or transparent substrates 30 at least two different color shift effects α-range and in the β-range surrounded by a transparent γ-range in which the substrate 30 and any print layers present are visible. In transmitted light when viewed from the front, with opaque and transparent substrates 30, a weakened or changed color impression and an increased perception of the α-range and the β-range as a lighter and darker range can occur. In this case, structures or prints located behind the second reflector layer 16 can become visible, which are not visible in reflected light. In the α-range, in which the first reflector layer 14 and the second reflector layer 16 are present, appear darker than the β-range, in which only the second reflector layer 16 is present.

In the case of layer structures in which structure-based optically variable effects are present only in the first dielectric layer 13 or only in the second dielectric layer 15, for example in the first dielectric layer 13 and not in the second dielectric layer 15, it is possible that in the complementary layer structure, i.e. replicated effects are present in the second dielectric layer 15 and are not present in the first dielectric layer 13, the observer perceives the optically variable effects differently.

The 16a to 16c The embodiments shown show a multi-layer body 10, in particular a security element, in which the α-area with a first color shift effect and possibly additional structure-based optically variable effects in the β-area with a second color shift effect and possibly additional structure-based optically variable effects are integrated, so that only the β-region borders on the γ-region.

Furthermore, it is also possible for the α region and the β region to be adjacent to each other without one region completely enclosing the other, so that both regions are at least partially adjacent to the γ region. It is also conceivable for the α region and the β region to be completely separated from each other without one region completely enclosing the other, with the γ region located between and around the α region and the β region. The α region and the β region can also be separated from the γ region by a colored ζ region.

All described variants of the multi-layer body 10 for the described layer structure with color layer 24 according to the 16a to 16c can be either an embossing foil or a laminating foil, where the carrier is not removed during embossing and remains in the product. The same optical color impression of the multilayer body 10, in particular of the security element, is obtained for both the embossing foil and the laminating foil.

List of reference symbols

1

Providing a raw material

2

Applying an absorber layer

3

Applying a first dielectric layer

4

Applying a first reflector layer

5

Applying a second dielectric layer

6

Applying at least one primer

7

Applying a second reflector layer

10

Multilayer body

11

Raw material

12

Absorber layer

13

first dielectric layer

14

first reflector layer

15

second dielectric layer

16

second reflector layer

17

primer

18

Photoresist layer

19

exposure mask

20

Functional layers

21

Etching resist layer

22

Lift-off paint

23

auxiliary layer

24

Paint layer

30

Substrat

d1

first predetermined thickness

d2

Total layer thickness or sum of first predetermined thickness and second predetermined thickness

d3

second predetermined thickness

α

α-range

β

β-range

γ

γ-range

δ

δ-range

ε

ε-range

ζ

ζ-range

QUOTES CONTAINED IN THE DESCRIPTION

This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 3858977 [0002]

Claims (48)

Method for producing a multi-layer body (10), in particular a security element for securing security documents, preferably designed as a hot stamping foil or cold stamping foil or laminating foil, having at least two different color shift effects perceptible to the human eye and/or a sensor, wherein the method comprises the following steps: a) providing a precursor material (1, 11) b) applying an absorber layer (2, 12) c) applying a first dielectric layer (3, 13) with a first predetermined thickness (d ₁ ) d) applying a first reflector layer (4, 14) e) applying a second dielectric layer (5, 15) with a second predetermined thickness (d ₃ ) f) applying at least one primer (6, 17), and wherein in the method for generating the two different color shift effects I) the first reflector layer (14) is removed in a β-region (β), so that in a the first reflector layer (14) is present in the α-region (α) and is not present in the β-region (β), so that a first color shift effect exists in the α-region (α) and a second color shift effect exists in the β-region (β), wherein the first color shift effect differs from the second color shift effect, wherein in a step g) a second reflector layer (7, 16) is applied and wherein the method steps are carried out in the following order: a), b), c), d), e), g) f) or II) the first dielectric layer (13) is structured by means of a lift-off process, so that the first dielectric layer (13) is present in an α-region (α) and is not present in a β-region (β), or vice versa, so that a first color shift effect exists in the α-region (α) and a second color shift effect exists in the β-region (β), wherein the first color shift effect differs from the second color shift effect and where the process steps are carried out in the following order: a), b), c), e), d), f). Procedure according to Claim 1 , characterized in that for providing the preliminary material (1, 11) in step a) the following steps are carried out, in particular in the specified order: - Providing a carrier - Coating a release layer - Coating at least one protective lacquer layer - Applying a replication layer and optionally introducing structures into the replication layer by means of thermal replication or UV replication. Procedure according to Claim 1 , characterized in that for providing the preliminary material (1, 11) in step a) the following steps are carried out, in particular in the specified order: - providing a carrier - optionally applying an adhesion promoter layer - applying a replication layer and optionally introducing structures into the replication layer by means of thermal replication or UV replication. Method according to one of the preceding claims, characterized in that in the method, in particular in variant II), the following steps are carried out for the lift-off process: k) applying a lift-off layer, in particular before step c); m) removing the lift-off layer together with the layers covering the lift-off layer, in particular after step c). Method according to one of the preceding claims, characterized in that in variant I) for the partial removal of the first reflector layer (14) the following steps are carried out, in particular wherein the steps are carried out after step d) and before step e): - applying a photoresist layer (18), in particular applying the photoresist layer (18) over the entire area; - exposing and developing the photoresist layer (18) with an exposure mask (19), preferably in the β-range, in particular in register for replication; - removing the first reflector layer (14), in particular by means of etching, in the β-range (β) and removing the photoresist layer (18). Method according to one of the preceding claims, characterized in that in variant I) for the partial removal of the first reflector layer (14) the following further steps are carried out are: - at least partially applying a washable lift-off varnish (22), preferably in an ε-region (ε), in particular by means of printing, preferably registered for replication, wherein the step is carried out after step a) and before step b); - removing the lift-off varnish (22) with a solvent in a washing process in order to remove the absorber layer (12), the first dielectric layer (13) and the first reflector layer (14), in particular to remove them in the ε-region (ε), wherein the step is carried out after step d) and before step e). Method according to one of the preceding claims, characterized in that in variant I) the following steps are further carried out: - at least partial application of a washable lift-off varnish (22), preferably in the ε-region (ε), in particular by means of printing, preferably registered for replication, wherein the step is carried out after step a) and before step b); - removal of the lift-off varnish (22) with a solvent in a washing process in order to remove the absorber layer (12), in particular in the ε-region (ε), wherein the step is carried out after step b) and before step c). Method according to one of the preceding claims, characterized in that in variant I) the following steps are carried out: - at least partial application of a washable lift-off resist (22), preferably in the ε-range (ε), in particular by means of printing, preferably registered for replication, wherein the step is carried out after step a) and before step b); - removal of the lift-off resist (22) with a solvent in a washing process in order to remove the absorber layer (12), in particular in the ε-range (ε), wherein the step is carried out after step b) and before step c); - application of a photoresist layer (18), in particular full-surface application of the photoresist layer (18), wherein the step is carried out after step d); - First exposure and development of the photoresist layer (18) with the absorber layer (12) as a first exposure mask (19), preferably in the ε-range (ε), and second exposure with a second exposure mask (19), in particular an external exposure mask (19), preferably in the β-range (β), in particular in the register for replication; - Removal of the first reflector layer (14), in particular by means of etching, in the β-range (β) and ε-range (ε) and removal of the photoresist layer (18), wherein the step is carried out before step e). Method according to one of the preceding claims, characterized in that in variant I) the following steps are carried out: - at least partial application of a washable lift-off resist (22), preferably in the ε-range (ε), in particular by means of printing, preferably registered for replication, wherein the step is carried out after step a) and before step b); - removal of the lift-off resist (22) with a solvent in a washing process in order to remove the absorber layer (12) and the first dielectric layer (13), in particular to remove them in the ε-range (ε), wherein the step is carried out after step c) and before step d), - application of a photoresist layer (18), in particular full-surface application of the photoresist layer (18), wherein the step is carried out after step d); - First exposure and development of the photoresist layer (18) with the absorber layer (12) as a first exposure mask, in particular in the ε-range (ε), and second exposure with a second exposure mask (19), in particular an external exposure mask (19), preferably in the β-range, in particular in the register for replication; - Removal of the first reflector layer (14), in particular by means of etching, in the β-range (β) and in the ε-range (ε) and removal of the photoresist layer (18), wherein the step is carried out before step e). Method according to one of the Claims 4 until 9 , characterized in that in variant I) for removing, in particular partially removing, the first reflector layer (14) the following steps are carried out: - at least partial application of a washable lift-off lacquer (22), preferably in a γ region (γ), in particular by means of printing, preferably registered for replication, wherein the step is carried out after step a) and before step b); - application of a photoresist layer (18), in particular full-surface application of the photoresist layer (18), wherein the step is carried out after step d); - exposing and developing the photoresist layer (18) by means of an exposure mask (19), in particular an external exposure mask (19), preferably in the β-range, in particular in register for replication; - removing the first reflector layer (14), in particular by means of etching, in the β-range (β) and removing the photoresist layer (18), wherein the step is carried out before step e); - removing the lift-off resist (22), in particular in the γ-range (γ), with a solvent in a washing process in order to remove the absorber layer (12), the first dielectric layer (13), the first reflector layer (14), the second dielectric layer (15) and the second reflector layer (16), in particular in the γ-range (γ), wherein the step is carried out after step g) and before step f). Method according to one of the Claims 4 until 10 , characterized in that in variant I) the following steps are carried out: - at least partial application of a washable lift-off resist (22), preferably in a δ-range (δ), in particular by means of printing, preferably registered for replication, wherein the step is carried out after step a) and before step b); - removal of the lift-off resist (22) with a solvent in a washing process in order to partially remove the absorber layer (12), in particular to remove it in the δ-range (δ), wherein the step is carried out after step b) and before step c); - application of a photoresist layer (18), in particular full-surface application of the photoresist layer (18), wherein the step is carried out after step d); - First exposure and development of the photoresist layer (18) with a first exposure mask, preferably in the β-range, and second exposure with a second exposure mask from the precursor material side, wherein the absorber layer acts as a second exposure mask and development of the photoresist layer (18), in particular in the δ-range, preferably in register with the lift-off resist and/or for replication and/or any layer of the multilayer body; - Removal of the first reflector layer (14), in particular by means of etching, in the β-range and in the δ-range (δ) and removal of the photoresist layer (18), wherein the step is carried out before step e); - Application of a further photoresist layer (18), in particular full-surface application of the further photoresist layer (18), wherein the step is carried out after step g) and before step f); - Third exposure and development of the further photoresist layer (18) with the absorber layer (12) as an exposure mask (19) in the δ-range (δ); - removing the second reflector layer (16), in particular by means of etching, in the δ region (δ), and removing the further photoresist layer (18), wherein the step is carried out before step f). Method according to one of the Claims 4 until 11 , characterized in that in variant I) the following steps are carried out, in particular in the following order: - optional application of an auxiliary layer (23), wherein the step is carried out after step a); - application of a first photoresist layer (18), in particular full-surface application of the first photoresist layer (18), wherein the step is carried out after step a) and before step b); - first exposure and development of the first photoresist layer (18) by means of a first exposure mask (19), preferably in the α region (α) and β region (β), and removal of the exposed regions of the first photoresist layer (18) and the auxiliary layer (23), in particular by means of washing, wherein the step is carried out before step b); - Second exposure and development of the remaining regions, in particular the δ-region (δ), of the first photoresist layer (18) and removal of the exposed regions, in particular by means of washing, in particular in the δ-region (δ), of the auxiliary layer (23), the first photoresist layer (18) and the absorber layer (12), wherein the step is carried out after step b); - Application of a second photoresist layer (18), in particular full-surface application of the second photoresist layer (18), wherein the step is carried out after step d); - Third exposure and development of the second photoresist layer (18) with a second exposure mask (19), in particular in the β-region, and fourth exposure and development of the second photoresist layer (18) from the precursor material side with the absorber layer (12) as a further exposure mask (19), in particular in the δ-region (δ); - removing the first reflector layer (14), in particular by means of etching, in the β-region (β) and in the δ-region (δ) and removing the second photoresist layer (18), wherein the step is carried out before step e); - applying a third photoresist layer (18), in particular applying the third photoresist layer (18) over the entire area, wherein the step is carried out after step g) and before step f); - fifth exposure and development of the third photoresist layer (18) from the precursor material side with the absorber layer (12) as an exposure mask (19), in particular in the δ-region (δ); - removing the second reflector layer (16), in particular by means of etching, in particular in the δ range (δ), and removing the third photoresist layer (18), wherein the step is carried out before step f). Method according to one of the Claims 1 until 4 , characterized in that in variant I) for the partial removal of the first reflector layer (14) the following steps are carried out, in particular wherein the steps are carried out after step d) and before step e): - applying an etching resist layer (21) in the α-region (α), preferably registered for replication - removing the first reflector layer (14), in particular by means of etching, in the β-region (β) - optionally washing or removing the etching resist layer (21). Procedure according to Claim 13 , characterized in that in variant I) for the partial removal of the first reflector layer (14) the following further steps are carried out: - at least partial application of a washable lift-off varnish (22), preferably in the ε-region (ε), in particular by means of printing, preferably registered for replication, wherein the step is carried out after step a) and before step b); - removal of the lift-off varnish (22) with a solvent in a washing process in order to remove the absorber layer (12), the first dielectric layer (13), the first reflector layer (14) and the etching resist layer (21), in particular to remove them in the ε-region (ε), wherein this step is carried out before step e). Procedure according to Claim 13 or 14 , characterized in that in variant I) for the partial removal of the first reflector layer (14) the following further steps are carried out: - at least partial application of a washable lift-off varnish (22), preferably in a γ-region (γ), in particular by means of printing, preferably registered for replication, wherein the step is carried out after step a) and before step b); - removal of the lift-off varnish (22) with a solvent in a washing process in order to remove the absorber layer (12), the first dielectric layer (13), the first reflector layer (14), the second dielectric layer (15), the second reflector layer (16) and the etching resist layer (21), in particular to remove them in the γ-region (γ), wherein this step is carried out after step g) and before step f). Method according to one of the Claims 1 until 4 , characterized in that in variant I) for the partial removal of the first reflector layer (14) the following steps are carried out: - at least partial application of a washable lift-off varnish (22) in the β-region (β), in particular by means of printing, preferably registered for replication, wherein the step is carried out after step b) and before step c); - removal of the lift-off varnish (22) with a solvent in a washing process in order to remove the first dielectric layer (13) and the first reflector layer (14) in the β-region (β), wherein the step is carried out after step d) and before step e). Method according to one of the Claims 1 until 3 , characterized in that in variant II) the following steps are carried out for structuring the first dielectric layer (13): - at least partial application of a washable lift-off varnish (22) in the β-region (β), in particular by means of printing, preferably registered for replication, wherein the step is carried out after step b) and before step c); - removal of the lift-off varnish (22) with a solvent in a washing process in order to remove the first dielectric layer (13) in the β-region (β), wherein the step is carried out after step c) and before step d). Method according to one of the preceding claims, characterized in that the method further comprises the following step: h) at least partial application of a color layer (24), in particular a photosensitive color layer (24). Procedure according to Claim 18 , characterized in that step h) is carried out after step a) or before step f). Procedure according to Claim 18 or 19 , characterized in that the color layer (24), in particular photosensitive color layer (24), is applied in step h) with a thickness in the range from 0.1 µm to 5 µm. Method according to one of the Claims 18 until 20 , characterized in that the color layer (24), in particular photosensitive color layer (24), is applied in a ζ-region (ζ). Multi-layer body (10), in particular security element for securing security documents, preferably hot stamping foil or cold stamping foil or laminating foil, in particular produced by a method according to the Claims 1 until 21 , comprising at least two different color shift effects perceptible to the human eye and/or a sensor, wherein the multi-layer body (10) comprises a precursor material (11), an absorber layer (12), a first dielectric layer (13) with a first predetermined thickness (d ₁ ), a first reflector layer (14), a second dielectric layer (15) with a second predetermined thickness (d ₃ ) and at least one primer (17), and wherein in the multi-layer body (10) for generating the two different color shift effects I), the first reflector layer (14) is removed in a β-region (β), so that the first reflector layer (14) is present in an α-region (α) and is not present in the β-region (β), so that a first color shift effect is present in the α-region (α) and a second color shift effect is present in the β-region, wherein the first color shift effect differs from the second color shift effect, wherein the multi-layer body (10) has a second reflector layer (16), and wherein the layers are arranged in the following order, preferably when viewed from the front: precursor material (11), absorber layer (12), first dielectric layer (13), first reflector layer (14), second dielectric layer (15), second reflector layer (16), at least one primer (17), or II) the first dielectric layer (13) is structured such that the first dielectric layer (13) is present in an α-region (α) and not present in a β-region (β), or vice versa, such that a first color-shift effect is present in the α-region (α) and a second color-shift effect is present in the β-region (β), wherein the first color-shift effect differs from the second color-shift effect, and wherein the layers are arranged in the following order: precursor material (11), absorber layer (12), first dielectric layer (13), second dielectric layer (15), first reflector layer (14), at least one primer (17). Multilayer body (10) according to Claim 22 , characterized in that the precursor material (11), in particular in the following order, has a carrier, a release layer, at least one protective lacquer layer and a replication layer, in particular wherein structures are introduced into the replication layer by means of thermal replication or UV replication. Multilayer body (10) according to Claim 22 , characterized in that the precursor material (11), in particular in the following order, has a carrier, an optional adhesion promoter layer and a replication layer, in particular wherein structures are introduced into the replication layer by means of thermal replication or UV replication. Multilayer body (10) according to one of the Claims 22 until 24 , characterized in that the first reflector layer (14) and/or the second reflector layer (16) comprises a material or combinations of materials selected from: aluminum, chromium, copper, tin, silver, indium nickel, iron, gold and/or an alloy of such metals. Multilayer body (10) according to one of the Claims 22 until 25 , characterized in that the first reflector layer (14) and/or the second reflector layer (16) have a refractive index in the range from 1.65 to 1.9. Multilayer body (10) according to one of the Claims 22 until 26 , characterized in that the first reflector layer (14) and/or the second reflector layer (16) have a layer thickness in the range from 10 nm to 100 nm or in the range from 1 µm to 3 µm. Multilayer body (10) according to one of the Claims 22 until 27 , characterized in that the absorber layer (12) has a layer thickness in the range from 4 nm to 20 nm. Multilayer body (10) according to one of the Claims 22 until 28 , characterized in that the absorber layer (12) is present in the α-range (α) and β-range (β). Multilayer body (10) according to one of the Claims 22 until 29 , characterized in that the first predetermined thickness (d ₁ ) of the first dielectric layer (13) is in the range from 0.1 µm to 1.0 µm, in particular from 0.05 µm to 0.80 µm, and/or that the second predetermined thickness (d ₃ ) of the second dielectric layer (15) is in the range from 0.1 µm to 1.0 µm, in particular from 0.05 µm to 0.80 µm, in particular wherein the first predetermined thickness (d ₁ ) and/or the second predetermined thickness (d ₃ ) have a variance of less than 10% of the thickness. Multilayer body (10) according to one of the Claims 22 until 30 , characterized in that the first dielectric layer (13) and/or the second dielectric layer (15) comprises a material or a combination of materials selected from: SiO ₂ , SiO _x , ZnS, Al ₂ O ₃ , TiO ₂ , Nb ₂ O ₅ and/or MgO. Multilayer body (10) according to one of the Claims 22 until 31 , characterized in that the multi-layer body (10) further comprises a color layer (24), in particular wherein the color layer (24) is arranged in a ζ-region (ζ) or over the entire surface. Multilayer body (10) according to Claim 32 , characterized in that the color layer (24) is arranged after the precursor material (11), in particular in the ζ-region (ζ), and/or is arranged before the at least one primer (17), in particular in the ζ-region (ζ) and/or over the entire surface. Multilayer body (10) according to one of the Claims 22 until 33 , characterized in that the first color shift effect, in particular in the α range (α), generates a first color dependent on the viewing angle and/or exposure angle on the basis of interference during exposure and the second color shift effect, in particular in the β range (β), generates a second color dependent on the viewing angle and/or exposure angle on the basis of interference during exposure. Multilayer body (10) according to one of the Claims 22 until 34 , characterized in that in the α-range (α) the first color, in particular the first color shift effect, is generated on the basis of a first optical thickness of the first dielectric layer (13), in particular wherein the first optical thickness is calculated from the product of the first predetermined thickness (d ₁ ) and the refractive index of the first dielectric layer (13). Multilayer body (10) according to one of the Claims 22 until 35 , characterized in that in the β-region (β) the second color, in particular the second color shift effect, is generated on the basis of a second optical thickness from the sum of the first dielectric layer (13) and the second dielectric layer (15), in particular wherein the second optical thickness is calculated from the sum of the products of the first predetermined thickness (d ₁ ) with the refractive index of the first dielectric layer (13) and the second predetermined thickness (d ₃ ) with the refractive index of the second dielectric layer (15). Multilayer body (10) according to one of the Claims 22 until 36 , characterized in that the difference between the first optical thickness in the α-range (α) and the second optical thickness in the β-range (β) is at least 30 nm, preferably at least 45 nm. Multilayer body (10) according to one of the Claims 22 until 37 , characterized in that the α-region (α) and the β-region (β) are arranged directly next to one another and/or separated from one another and/or enclosing one another. Multilayer body (10) according to one of the Claims 22 until 38 , characterized in that the multi-layer body (10) has at least one γ-region (γ) in which the at least one primer (17) is present and the first dielectric layer (13), the second dielectric layer (15), the first reflector layer (14), the second reflector layer (16) and the absorber layer (12) are not present. Multilayer body (10) according to Claim 39 , characterized in that the at least one γ-region (γ) completely encloses the α-region (α) and the β-region (β). Multilayer body (10) according to a Claims 22 until 40 , characterized in that the multi-layer body (10) has at least one δ-region (δ) in which the first reflector layer (14), the second reflector layer (16) and the absorber layer (12) are not present, and that the first dielectric layer (13) and/or the second dielectric layer (15) are present in at least one δ-region (δ). Multilayer body (10) according to Claim 41 , characterized in that in at least one δ-region (δ) full-area or partial structure-based optically variable structures are molded in the first dielectric layer (13) and/or second dielectric layer (15), which preferably generate optically variable effects. Multilayer body (10) according to Claim 41 or 42 , characterized in that the at least one δ-region (δ) completely encloses the α-region (α) and the β-region (β) or that the at least one δ-region (δ) separates the α-region (α) from the β-region (β) or vice versa. Multilayer body (10) according to one of the Claims 22 until 43 , characterized in that the multi-layer body (10) has at least one ε-region (ε) in which the first reflector layer (14) and/or the second reflector layer (16) is present. Multilayer body (10) according to Claim 44 , characterized in that in at least one ε-region (ε) fully or partially structure-based optically variable structures are molded, which preferably generate optically variable effects. Multilayer body (10) according to Claim 44 or 45 , characterized in that the at least one ε-region (ε) is present at least in regions, in particular wherein the ε-region (ε) completely encloses the α-region (α) and the β-region (β). Multilayer body (10) according to one of the Claims 22 until 46 , characterized in that the multi-layer body (10) has at least one ζ-region (ζ) in which the first reflector layer (14), the second reflector layer (16) and the absorber layer (12) are not present, and that in the at least one ζ-region (ζ) at least one color layer (24) is present. Multilayer body (10) according to Claim 47 , characterized in that the at least one ζ-region (ζ) is present at least in regions, in particular wherein the at least one ζ-region (ζ) completely encloses the α-region (α) and the β-region (β), preferably wherein the ζ-region (ζ) is completely enclosed by the at least one δ-region (δ).

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