EP3013598B1 - Method for producing a multilayer element, and multilayer element - Google Patents

Description

The invention relates to a method for producing a multi-layer body with a carrier layer and a single-layer or multi-layer decorative layer formed on and / or in the carrier layer, as well as a multilayer body, a security element and a security document.

Optical security elements are often used to make it difficult to copy documents or products to prevent their misuse, especially counterfeiting. Thus, optical security elements find use for securing documents, banknotes, credit and debit cards, ID cards, packaging of high-quality products and the like. In this case, it is known to use optically variable elements as optical security elements which can not be duplicated by conventional copying methods. It is also known to provide security elements with a structured metal layer, which is in the form of a text, logos or other pattern.

The production of a structured metal layer from a metal layer applied in a planar manner, for example by sputtering or vapor deposition, requires a large number of processes, in particular when producing particularly fine structures should be, which have a high security against counterfeiting. For example, it is known to partially demetallize and thus structure a metal layer applied over the entire area by positive or negative etching or by laser ablation. Alternatively, it is possible to apply metal layers by means of using vapor masks already in structured form on a support.

The more manufacturing steps are provided for the production of the security element, the greater importance receives the register or register accuracy of the individual process steps, i. the accuracy of the positioning of the individual tools relative to one another in the formation of the security element with respect to features or layers or structures already present on the security element.

The document DE 10 2008 013 073 A1 discloses a method according to the preamble of claim 1.

Object of the present invention is to provide a particularly difficult to reproduce multilayer body and a method for producing such a multilayer body.

1. a) auf eine Trägerlage eine ein- oder mehrschichtige erste Dekorlage aufgebracht wird;
2. b) mindestens eine Metallschicht auf der der Trägerlage abgewandten Seite der ersten Dekorlage aufgebracht wird;
3. c) die mindestens eine Metallschicht derart strukturiert wird, dass die Metallschicht in ein oder mehreren ersten Zonen des Mehrschichtkörpers in einer ersten Schichtdicke vorgesehen ist und in ein oder mehreren zweiten Zonen des Mehrschichtkörpers in einer von der ersten Schichtdicke unterschiedlichen zweiten Schichtdicke vorgesehen ist, wobei insbesondere die zweite Schichtdicke gleich null ist;
4. d) auf der der ersten Dekorlage abgewandten Seite der Metallschicht eine ein- oder mehrschichtige zweite Dekorlage aufgebracht wird;
5. e) die erste und/oder zweite Dekorlage unter Verwendung der Metallschicht als Maske in einem ersten Bereich des Mehrschichtkörpers derart strukturiert wird, dass die erste und/oder zweite Dekorlage in den ersten oder zweiten Zonen zumindest teilweise entfernt wird.

The object is achieved by a method for producing a multilayer body, in particular an optical security element or an optical decorative element, wherein in the method:

1. a) a single or multi-layered first decorative layer is applied to a carrier layer;
2. b) at least one metal layer is applied on the side facing away from the carrier layer of the first decorative layer;
3. c) the at least one metal layer is structured in such a way that the metal layer is provided in one or more first zones of the multilayer body in a first layer thickness and is provided in one or more second zones of the multilayer body in a second layer thickness different from the first layer thickness, wherein in particular the second layer thickness is zero;
4. d) on the side of the metal layer facing away from the first decorative layer, a or multi-layered second decorative layer is applied;
5. e) the first and / or second decorative layer is patterned using the metal layer as a mask in a first region of the multilayer body such that the first and / or second decorative layer is at least partially removed in the first or second zones.

The steps a) to e) of the process according to the invention are preferably carried out in the order indicated.

The object is further achieved by a multi-layer body having a single-layer or multi-layered first decorative layer, a single or multi-layered second decorative layer and at least one metal layer arranged between the first and second decorative layers, wherein the metal layer is structured in such a way that the at least one metal layer is provided in a first region of the multilayer body in one or more first zones of the multilayer body in a first layer thickness and is provided in one or more second zones of the multilayer body in a second layer thickness different from the first layer thickness, wherein in particular the second layer thickness is equal to zero, and wherein the first and second decorative layer are congruent to each other and structured to the metal layer. The first and the second decorative layer and the metal layer preferably have partial structures, so that the first and second decorative layers in the first region in the first or second zones are at least partially congruent to one another and to the metal layer.

Such a multilayer body is preferably obtainable by the methods described above.

The multilayer body according to the invention can be used, for example, as a label, laminating film, hot stamping film or transfer film to provide an optical security element which is suitable for securing documents, banknotes, credit and debit cards, identity cards, packaging of high quality Products and the like is used. In this case, the decorative layers and the at least one register layer arranged precisely arranged metal layer can serve as an optical security element.

The invention achieves the formation of particularly anti-counterfeit multilayer bodies. In the method, the metal layer serves as a mask during the manufacture of the multilayer body, preferably as an exposure mask for exposure, i. the photoactivation of a photoactivatable layer, which may be comprised by the first and / or second decorative layer, or as a mask for protecting the first zones or the second zones, for example, prior to solvent attack, and on the finished multilayer body to provide an optical effect. The metal layer thus fulfills several completely different functions.

The structuring according to step c) and / or step e) can in this case also take place only in a partial area of the multi-layer body, which then in particular forms the first area.

Preferably, the first and second decorative layers are patterned using the metal layer as a mask in the first region such that the first and second decorative layers are at least partially removed respectively in the first or second zones, or the metal layer using the first or second decorative layer as Mask is structured.

As a result, register-accurate structuring of the first decorative layer, the second decorative layer and the metal layer relative to one another is achieved without additional use of registration devices and enables a very precise positionally accurate structuring of these layers relative to one another.

In conventional methods for producing an etching mask by means of a mask exposure, the mask either as a separate unit, for example as a separate foil or as a separate glass plate / glass roller, or as a If there is a subsequently printed-on layer, there may be the problem that linear and / or non-linear distortions in the multilayer body caused by prior alignment of the mask on the multilayer body are not completely compensated for over the entire surface of the multilayer body due to thermal and / or mechanical straining process steps can, although the mask alignment on existing (usually arranged on the horizontal and / or vertical edges of the multilayer body) registration or registration marks is done. The tolerance fluctuates over the entire surface of the multilayer body in a relatively large area. The method preferably uses the first and second zones defined by the patterning of the first or second decorative layer or the metal layer, directly or indirectly, as a mask for structuring the remaining layers, so that these problems are avoided.

The mask designed as a decorative layer or metal layer is therefore subjected to all subsequent process steps of the multilayer body, and thereby automatically follows all distortions possibly caused by these process steps in the multilayer body itself. Thus, no additional tolerances, in particular no additional tolerance fluctuations, over the surface of the multilayer body occur because the subsequent generation of a mask and the necessary register-accurate subsequent positioning of this independent of the previous process history mask is avoided. The tolerances or register accuracies in the method according to the invention are due only to possibly not absolutely exactly formed edges of the first and second zones and of the metal layer whose quality is determined by the particular manufacturing method used. The tolerances or register accuracies in the method according to the invention are approximately in the micrometer range, and thus far below the resolution of the eye; ie the unarmed human eye can no longer perceive existing tolerances.

Register or register accuracy is to be understood as meaning the positional arrangement of superimposed layers.

A layer comprises at least one layer. A decorative layer comprises one or more decorative and / or protective layers which are in particular formed as lacquer layers. The decorative layers can be arranged over the entire surface or in pattern-like structured form on the carrier layer.

When an arrangement of an object in the first zone and / or the second zone is described below, it is to be understood that the object is arranged such that the object and the first and / or the second zone are perpendicular to the plane of the carrier layer overlap seen.

The at least one metal layer may consist of a single metal layer or of a sequence of two or more metal layers, preferably different metal layers. The metal used for the metal layers is preferably aluminum, copper, gold, silver or an alloy of these metals.

It is further advantageous if in step c), i. for structuring the metal layer, a first resist layer which can be activated by means of electromagnetic radiation is applied to the side of the metal layer remote from the first decorative layer, and the first resist layer is exposed using an exposure mask by means of said electromagnetic radiation. Subsequently, further steps for structuring the metal layer, such as development, etching and stripping, then preferably follow.

It is advantageous if the following procedure is followed: The second decorative layer applied in step d) comprises one or more second colored resist layers which can be activated by means of electromagnetic radiation. In step e), the one or more second, colored resist layers are produced from the side of the carrier layer by means of said electromagnetic radiation exposed, wherein the metal layer serves as an exposure mask. In this way, the second decorative layer can be structured in the perfect register to the metal layer.

In a further advantageous embodiment, the one or more second, colored resist layers comprise at least two different colorants or colorants of different concentration containing resist layers. One or more of the one or more second, colored resist layers may be applied in pattern form by means of a printing process. These colored resist layers are preferably formed in pattern form to form a first motif.

It is particularly advantageous if the first resist layer is exposed in step c) from the side of the carrier layer, wherein the mask for exposing the first resist layer is formed by the first decorative layer. For this purpose, the first decorative layer has a first transmittance perpendicular to the plane of the carrier layer in the first region in the one or more first zones and a second transmittance greater in the one or more second zones compared to the first transmittance, said transmittances being preferably refer to an electromagnetic radiation having a suitable wavelength for photoactivation of the first resist layer.

During the exposure of the photoactivatable layer by means of the said electromagnetic radiation from the side of the carrier layer facing away from the photoactivatable layer through the first decorative layer, the first decorative layer thus acts as an exposure mask, since in the first zone it has a transmittance which is higher than the transmittance of the first second zone is lowered. Next, the exposure takes place through the metal layer and thus the layer to be structured.

It is also expedient if a particular colored etching resist layer is partially applied to a partial region of the metal layer in which no first resist layer is provided. In the case of a later etching process, the etching resist layer allows the metal layer to be patterned independently of the exposure of the first resist layer in this subregion, as a result of which further graphic effects can be achieved. In this case, the etching resist layer preferably consists of polyvinyl chloride.

The first decorative layer also fulfills several completely different functions, namely the function of an exposure mask and the provision of optical information.

The first decorative layer is preferably designed so that a viewer of an article decorated by means of the multi-layer body can view the at least one metal layer through the first decorative layer. For example, the first decorative layer can be transparent or translucent. Further, it is also possible that the first decorative layer forms a (colored) second, visible to the human observer motif, which is designed independently of the first and second zones. For this purpose, the first decorative layer can be colored for example transparent or translucent.

By using the first decorative layer as the exposure mask, the first resist layer is patterned in register with the first and second zones of the multilayer body, ie the structures of the structured first resist layer are arranged in register with the first and second zones of the decorative layer. In addition, according to this embodiment of the method, the at least one metal layer is patterned in register with the resist layer. Thus, the method allows the formation of at least four mutually register-formed layers: the first decorative layer, the first resist layer, the at least one metal layer and the second decorative layer. As a result of the method, the multilayer body has the metal layer as well as the two decor layers register exactly in the first zone or in the second zone of the multilayer body.

The use of the first decorative layer as the exposure mask for the first resist layer or the metal layer as the exposure mask for a second resist layer which may be covered by the second decorative layer inevitably results in perfect register accuracy of the respective exposure mask to the metal layer or the second decorative layer, i. the first decorative layer and the structured metal layer itself act at least in some areas as exposure masks. The first decorative layer or the metal layer and the exposure mask thus each form a common functional unit. The method, which is as simple as it is effective, gives rise to a considerable advantage over conventional methods in which a separate exposure mask has to be registered in layers of the multilayer body, wherein in practice register deviations can only be completely avoided in very few cases.

It is possible for the first decorative layer to comprise a first lacquer layer which is arranged in the first zone with a first layer thickness and in the second zone either not or with a smaller second layer thickness compared to the first layer thickness on the carrier layer, so that the first decorative layer in the first zone having said first transmittance and in the second zone said second transmittance. As a result, the mask function of the first decorative layer is realized in a simple manner.

The paint layers can be particularly patterned by a printing process, such as gravure, offset printing, screen printing, inkjet printing, so that both the mask function and the desired optical effect can be realized.

To be able to realize a variety of optical effects or security features, it is also advantageous if the paint layers contain a UV absorber and / or a colorant.

In the case of the process variants which comprise an exposure through the first decorative layer, it has proven advantageous to choose the thickness and the material of the first decorative layer such that the first transmittance is greater than zero. The thickness and the material of the first decorative layer are chosen so that electromagnetic radiation with the appropriate wavelength for the photoactivation partially penetrates the first decorative layer in the first zone. The exposure mask formed by the first decorative layer is therefore designed to be radiation-permeable in the first zone.

It has proven useful if the thickness and the material of the first decorative layer are chosen such that the ratio between the second and the first transmittance is equal to or greater than 2. The ratio between the first and the second transmittance is preferably 1: 2, also referred to as contrast 1: 2. A contrast of 1: 2 is at least an order of magnitude lower than with conventional masks. It has hitherto not been customary to use a mask for exposing a resist layer, which mask has as little contrast as the preferably used first decorative layer described here. When exposing a resist to a conventional mask (eg, a chrome mask), there are opaque (OD> 2) and fully transparent areas; So the mask has a high contrast. A conventional aluminum mask has a typical contrast of 1: 100 because the typical transmittance of an aluminum layer is at values around 1%, corresponding to an optical density (= OD) of 2.0. The transmittance (= T) and the OD are linked together as follows: T = 10 ^-OD (ie OD = 0 corresponds to T = 100%, OD = 2 corresponds to T = 1%, OD = 3 corresponds to T = 0.1% ). In contrast to the conventional exposure methods, the resist layer is exposed not only by a mask with low contrast (= decorative layer), but also by the metal layer.

The area of the photoactivatable first resist layer (lower transmittance) exposed through the first zones is preferably activated to a lesser extent than the area of the photoactivatable first resist layer exposed through the second zones (greater transmittance). In this case, the first resist layer may be temporarily applied to the metal layer during the production of the multilayer body, where it serves to structure the metal layer, or else be part of the second decorative layer or serve for structuring the second decorative layer.

It has proven useful if the thickness and the material of the first decorative layer is selected so that the electromagnetic radiation, measured after passing through a layer package consisting of the carrier layer and the decorative layer, in the first zone a transmittance of about 0% to 30%, preferably from about 1% to 15% and in the second zone has a transmittance of about 60% to 100%, preferably from about 70% to 90%. The transmittances from these ranges of values are preferably selected such that a contrast of 1: 2 results.

According to a second embodiment, the first resist layer is exposed in step c) from the side facing away from the carrier layer, wherein for exposing the first resist layer, a mask between the first resist layer and a light source, which is used for exposure, is arranged. The mask has, viewed perpendicularly to the plane of the carrier layer, a first transmittance in the first region in the one or more first zones and a second transmittance in the one or more second zones in comparison to the first transmittance, wherein the transmittances are preferably on relate an electromagnetic radiation having a suitable wavelength for photoactivation of the first resist layer.

Since no structures are yet introduced into the multilayer body at this stage of the process, an external mask can be used without register problems. The structures in the metal layer produced by means of the external mask then later act in the described manner as a mask for the generation of additional register-accurate structures in the first and / or second decorative layer.

It has proven useful to use a positive photoresist whose solubility increases upon activation by exposure, or to use a negative photoresist, to form the photoactivatable layers, in particular the first and / or second resist layers activated by electro-magnetic radiation Solubility decreases upon activation by exposure. Exposure is the selective irradiation of a photoactivatable layer through an exposure mask with the aim of locally modifying the solubility of the photoactivatable layer by a photochemical reaction. According to the nature of the photochemically achievable solubility change, a distinction is made between the following photoactivatable layers which can be formed as photoresists: In a first type of photoactivatable layers (eg negative resist) their solubility decreases by exposure compared to unexposed zones of the layer For example, because the light leads to the curing of the layer; in a second type of photoactivatable layers (e.g., positive resist) their solubility increases by exposure to unexposed areas of the layer, for example, because the light results in the decomposition of the layer.

Further, it has been found useful to remove the first and / or second resist layer using a positive photoresist in the second zone or using a negative photoresist in the first zone. This can be done by a solvent such as a caustic or acid. When using a positive photoresist, the more exposed second region of the resist layer has a higher solubility in the one or more second zones than the less exposed first region of the resist layer in the one or more first zones. Therefore, a solvent dissolves the material of the resist layer (positive photoresist) disposed in the second zone faster and better than the material of the resist layer disposed in the first zone. By using a solvent, the resist layer can therefore be patterned, ie the resist layer is removed in the second zone, but remains in the first zone.

The first resist layer is then preferably used as an etching mask for an etching step, by means of which the regions of the metal layer not covered with the first resist layer or one of the metal layers are removed. Subsequently, the first resist layer may be stripped, i. be removed.

It is advantageous if UV radiation is used for the exposure of the first and / or second resist layer, preferably with a radiation maximum in the region of 365 nm. The transmission properties of the decorative layer used as a mask can thus be different in the ultraviolet range than in the visual range. Thus, the structure of the mask is not dependent on the visually perceptible optical effect to be achieved by the decorative layers. In the range of 365 nm, PET (= polyethylene terephthalate), which can form an essential part of the carrier layer, is also transparent. In the range of this wavelength is the maximum of the emission of a high pressure mercury radiator.

It is possible for the first and / or second resist layer to have a thickness in the range from 0.3 μm to 0.7 μm.

In a further advantageous embodiment of the invention, step c) is carried out after step d), and in step c) the metal layer is structured using the second decorative layer as a mask, in particular by applying an etchant and removing the areas of the metal layer which are not protected by the mask. In step e) then the first decorative layer using the Metal layer as a mask, in particular by applying a solvent and removing the not protected by the mask areas of the first decorative layer, structured.

The second decorative layer has here in addition to the optical function achieved by the coloring so an additional function as a mask, on the basis of which subsequently the register-accurate structuring of the metal layer. Thus, without the use of external masks, a perfect registration between the second decorative layer and the metal layer can be achieved, so that the structures of the two layers overlap exactly. At the same time, this embodiment does not require exposure and development steps, resulting in a particularly simple procedure. After the metal layer has been patterned using the second decorative layer, the metal layer can in turn be used as a mask for structuring the first decorative layer, for example by removing the zones of the first decorative layer not covered by the metal layer by a solvent.

It is also advantageous if the second decorative layer is applied by pattern printing, wherein the second decorative layer is provided in the first zones with a third layer thickness and is provided in the second zones with a fourth layer thickness different from the third layer thickness, in particular the fourth Layer thickness is zero. As a result, both the mask function and the desired optical effect of the second decorative layer can be realized in a simple manner.

In a further advantageous embodiment, the second decorative layer is resistant to an etchant used for patterning the metal layer and to a solvent used for structuring the first decorative layer. Thus, the second decorative layer can serve both as a protective mask for structuring the metal layer and for structuring the first decorative layer.

It is also advantageous if the second decorative layer comprises one or more colored layers, which are applied in particular by a printing process.

In a further advantageous embodiment, the first resist layer and / or areas of the first decorative layer not protected by the metal layer are removed by a solvent. A preferred embodiment also provides for substantially completely removing ("stripping") the resist layer during the work step for structuring the metal layer or in a separate, subsequent, subsequent work step. By reducing the number of superimposed layers in the multi-layer body, its durability and durability can be increased because adhesion problems between adjacent layers are minimized. Furthermore, the optical appearance of the multilayer body can be improved, since after removal of the resist layer, which in particular can be colored and / or not completely transparent, but only translucent or opaque, the underlying areas are exposed again. For special applications without particularly high demands on the durability or the visual appearance, however, it is also possible to leave the first resist layer on the structured layer.

It has proven useful if, in step c), the zones of the metal layer not protected by the first resist layer and / or the second decorative layer are removed by an etchant. This can be done by an etchant such as an acid or alkali. It is preferred if the partial removal of the resist layer in the respective region and the regions of the metal layer which are thereby exposed take place in the same process step. This can be achieved in a simple manner by a solvent / etchant such as a lye or acid which is capable of both the resist layer - in the case of a positive resist in the exposed region, in the case of a negative resist in the unexposed region - and the layer to be structured to remove, that attacks both materials. In this case, the resist layer must be formed so that they to remove the solvent or etchant to be structured when using a positive resist in the unexposed area, when using a negative resist in the exposed area at least for a sufficient time, that is resistant to the contact time of the solvent or etchant.

It has also proved to be useful if the carrier layer comprises at least one functional layer, in particular a release layer and / or a protective lacquer layer, on the side facing the first decorative layer. This is advantageous in particular when using the multilayer film as a transfer film, in which the functional layer enables a problem-free detachment of the carrier layer from a transfer layer which comprises at least one layer of the first and second decorative layer and the metal layer

It is also advantageous if the first and / or second decorative layer comprise a replicate varnish layer into which a surface relief is molded, and / or that a surface relief is molded into the surface of the carrier layer facing the first decorative layer.

Preferably, the surface relief comprising a diffractive structure preferably having a spatial frequency between 200 and 2000 lines / mm, in particular a hologram, Kinegram ^®, a linear grating or a cross grating, a diffractive structure zero order, in particular with a spatial frequency of more than 2000 lines / mm, a blazed grating, a refractive structure, in particular a microlens field or a retroreflective structure, an optical lens, a free-form surface structure, and / or a matt structure, in particular an isotropic or anisotropic matt structure. Matt structure refers to a structure with light-scattering properties, which preferably has a stochastic surface matt profile. Matt structures preferably have a relief depth (peak-to-valley, PV) between 100 nm and 5000 nm, more preferably between 200 nm and 2000 nm. Matt structures preferably have a surface roughness (Ra) between 50 nm and 2000 nm, more preferably between 100 nm and 1000 nm. The matte effect can either isotropic, ie equal to all azimuth angles, or anisotropic, ie varying at different azimuth angles.

A replication layer is generally understood as meaning a layer which can be produced superficially with a relief structure. These include, for example, organic layers such as plastic or lacquer layers or inorganic layers such as inorganic plastics (for example silicones), semiconductor layers, metal layers etc., but also combinations thereof. It is preferred that the replication layer is formed as a replicate varnish layer. To form the relief structure, a radiation-curable or thermosetting replication layer or a thermoplastic replication lacquer layer can be applied, a relief can be molded into the replication layer, and the replication layer optionally cured with the embossment embossed therein.

It is also advantageous if, after the structuring of the metal layer, a compensating layer is applied which rests, in particular, on the surface regions of the first decorative layer, the second decorative layer and / or the carrier layer facing away from the carrier layer.

It is preferred if, after structuring of the metal layer, the metal layer and the first resist layer are removed in the first or the second zone and present in the other region, or in the corresponding process variants in the zones protected by the second resist layer and in remaining area is removed. By applying the compensating layer recessed areas / depressions of the metal layer, the first decorative layer and / or the second decorative layer can be at least partially filled. It is possible that by applying the compensating layer, recessed regions / depressions of the first or second resist layer are at least partially filled. The leveling layer may comprise one or more different layer materials. The compensation layer may be formed as a protective and / or adhesive and / or decorative layer.

It is possible for an adhesion-promoting layer (adhesive layer) to be applied to the side of the compensating layer facing away from the carrier layer, which layer may also have a multilayer structure. Thus, the multilayer body formed as a laminating film or transfer film may be bonded to a target substrate adjacent to the primer layer, e.g. in a hot stamping or IMD (IMD = In-Mold Decoration) process. The target substrate can be, for example, paper, paperboard, textile or another fibrous material, or a plastic or a composite of, for example, paper, cardboard, textile and plastic, while being flexible or predominantly rigid.

Preferably, a protective coating is applied to the multilayer body on the side of the multilayer body facing away from the carrier layer. This protects the multilayer body from environmental influences and mechanical manipulations.

It is also advantageous if the first and / or second decorative layer is bleached by exposure. In order for any remaining photoreactive substances in the unexposed areas of the multilayer body are reacted and prevents later uncontrolled bleaching. In this way, a particularly color-stable multilayer body is obtained.

Preferably, the multi-layer body comprises a particular full-surface carrier layer. The carrier layer must be permeable to the radiation used in the respective exposure step. It is also possible to use electromagnetic radiation having a wavelength in the range from 254 to 314 nm for the following carrier materials: olefinic carrier material such as PP (= polypropylene) or PE (= polyethylene), carrier material based on PVC and PVC copolymer, Support material based on polyvinyl alcohol and polyvinyl acetate, polyester support based on aliphatic raw materials.

It is possible that the carrier layer has a single-layer or multi-layer carrier film. A thickness of the carrier foil of the multilayer body according to the invention in the range of 12 to 100 microns has proven itself. As a material for the carrier film is for example PET, but also other plastic materials, such as PMMA (= polymethyl methacrylate) in question.

It is particularly expedient if the first decorative layer has a first transmittance perpendicular to the plane of the carrier layer in the first zone and a second transmittance greater in the second zone compared to the first transmittance, said transmittances being based on electromagnetic radiation in the visual zone and / or ultraviolet and / or infrared spectrum. As already explained with reference to the method, such a first decorative layer itself can serve as an exposure mask for the structuring of the metal layer, resulting in a multilayer body with a register-accurate layer arrangement.

It is also possible for the second decorative layer in the first zone or the second zone to have at least one resist layer which is photoactivated by means of the said electromagnetic radiation, wherein the at least one metal layer and the resist layer are aligned in register with one another.

It is possible for the first and / or second decorative layer to comprise one or more layers which are colored with at least one opaque and / or at least one transparent colorant which is colored or color-producing at least in one wavelength range of the electromagnetic spectrum, in particular colorfully colored or is colorfully color-producing, in particular that a colorant is contained in one or more of the layers of the first and / or second decorative layer, which can be excited outside the visible spectrum and produces a visually recognizable colored impression. It is preferable that the first and / or second visible light decorating layer having a wavelength in a range of about 380 to 750 nm is at least partially transmissive.

It is possible for the first and / or second decorative layer to comprise at least one pigment or at least one colorant of the color cyan, magenta, yellow or black (CMYK = cyan magenta yellow key) or of the color red, green or blue (RGB), in particular for producing a subtractive mixed color, is colored, and / or provided with at least one red and / or green and / or blue fluorescent radiation-stimulable pigment or dye and thereby in particular an additive mixed color Irradiation can be generated. As an alternative to a mixed color, it is also possible to use pigments or dyes which produce a specific, premixed special color or as a color from a special color system (eg RAL, HKS, ^Pantone® ), for example orange or violet.

As a result, the first decorative layer fulfills a dual function in the process variants in which exposure takes place through the first decorative layer. On the one hand, the first decorative layer serves as an exposure mask for forming at least one metal layer, which is arranged in register with the first and second zones of the multilayer body. In particular, the first decorative layer serves as an exposure mask for a partial demetallization of a metal layer. On the other hand, both decorative layers, or at least one or more layers of the respective decorative layer, serve on the multi-layer body as an optical element, in particular as a single- or multi-colored ink layer for coloring the at least one structured layer, the ink layer registering over and / or next to / adjacent to is arranged on the at least one metal layer layer.

It is possible for the first and / or second decorative layer to comprise a replication lacquer layer in which a surface relief comprising at least one relief structure is molded and the at least one metal layer is arranged on the surface of the at least one relief structure.

It is possible for the at least one relief structure to be arranged at least partially in the first zone and / or in the second zone. In this case, the surface layout of the relief structure can be adapted to the surface layout of the first and the second zone, in particular formed in the register, or the surface layout of the relief structure is formed for example as a continuous endless pattern regardless of the surface layout of the first and the second zones. The relief structure can of course also in the process variants that do not require zones of different transmission in the decorative layer, are introduced and adapted to the surface layout of the decorative layer. The inventive arrangement of the resist layer on the first side of the carrier layer so that the resist layer is disposed on the side facing away from the carrier layer side of at least one metal layer and the decorative layer on the other side of the at least one metal layer, it is possible, the layer to be patterned at least partially on a relief structure, as opposed to patterning processes using washcoat.

It is possible for the first and / or second decorative layer to comprise one or more of the following layers: liquid-crystal layer, polymer layer, in particular conductive or semiconductive polymer layer, interference thin-film layer packet, pigment layer.

It is possible for the first and / or decorative layer to have a thickness in the range from 0.5 μm to 5 μm.

It is possible that UV-absorbers may be added to the material for forming the decorative layer, especially if the material of the decorative layer does not contain a sufficient amount of UV-absorbing constituents, such as, for example, UV-absorbing pigments or UV-absorbing dyes. It is possible that the decorative layer inorganic absorber with high Streuanteilteil, in particular nano-scaled UV absorbers based on inorganic oxides has. As suitable oxides especially TiO ₂ and ZnO have been found in highly dispersed form, as in sunscreen creams with a high sun protection factor can be used. These inorganic absorbers lead to a high degree of scattering and are therefore particularly suitable for a matt, in particular semi-gloss, coloring of the decorative layers.

However, it is also possible for the decorative layers to comprise organic UV absorbers, in particular benzotriazole derivatives, with a mass fraction in the range of about 3% to 5%, in particular if the material of the decorative layers does not contain a sufficient amount of UV-absorbing constituents, such as UV-absorbing pigments or UV-absorbing dyes. Suitable organic UV absorber sold under the trade name Tinuvin ^® by the company BASF. It is possible that the decorative layer comprises fluorescent dyes or organic or inorganic fluorescent pigments in combination with finely divided pigments, especially Mikrolith ^® -K. Due to the excitation of these fluorescent pigments, the UV radiation is for the most part already filtered out in the respective decorative layer, so that only an insignificant fraction of the radiation reaches the resist layer. The fluorescent pigments can be used in the multilayer body as an additional security feature.

The use of UV-activatable resist layers offers advantages: By using a UV absorber which has a transparent effect in the visual wavelength range in the first and / or second decorative layer, the "color" property of the respective decorative layer can be in the visual wavelength range of desired properties of the respective Decor layer for structuring the respective resist layer (eg sensitive in the near UV) and thereby the at least one metal layer are separated. In this way, a high contrast between the first and the second zone can be achieved, regardless of the visually recognizable coloring of the decorative layers.

It is possible that the at least one metal layer has a thickness in the range of 20 nm to 70 nm. It is preferable that the metal layer of the multi-layered body as a reflection layer from the side of the replication layer incident light is used. By combining a relief structure of the replication layer and a metal layer arranged underneath, a multiplicity of different optical effects which can be used effectively for safety aspects can be generated. The metal layer may consist, for example, of aluminum or copper or silver, which is galvanically reinforced in a subsequent method step. The metal used for galvanic reinforcement may be the same or different than the metal of the patterned layer. An example is the galvanic reinforcement of a thin aluminum layer, copper layer or silver layer with copper.

It is possible that recesses of the first and / or second decorative layer and the metal layer are filled with a leveling layer.

It is preferred if the refractive index n1 of the compensation layer in the visible wavelength range is in the range from 90% to 110% of the refractive index n2 of the replication layer. It is preferred if in the first or second zones where the metal layer is removed and a spatial structure, i. a relief is formed on the surface, the depressions and elevations of the relief are leveled by means of a compensation layer having a similar refractive index as the replication layer (Δn = | n2-n1 | <0.15). In this way, the optical effect formed by the relief is no longer perceptible in the zones in which the compensating layer is applied directly to the replication layer, because equalization with a material having a sufficiently similar refractive index does not produce an optically sufficiently effective interface.

It is possible that the leveling layer may be used as an adhesion layer, e.g. Adhesive layer is formed.

Fig. 1a

einen schematischen Schnitt einer ersten Fertigungsstufe des in Fig. 1d dargestellten Mehrschichtkörpers;

Fig. 1b

einen schematischen Schnitt einer zweiten Fertigungsstufe des in Fig. 1d dargestellten Mehrschichtkörpers;

Fig. 1c

einen schematischen Schnitt einer dritten Fertigungsstufe des in Fig. 1d dargestellten Mehrschichtkörpers;

Fig. 1d

einen schematischen Schnitt eines nach einer ersten Ausführungsform des erfindungsgemäßen Verfahrens hergestellten erfindungsgemäßen Mehrschichtkörpers;

Fig. 2a

einen schematischen Schnitt einer ersten Fertigungsstufe des in Fig. 2d dargestellten Mehrschichtkörpers;

Fig. 2b

einen schematischen Schnitt einer zweiten Fertigungsstufe des in Fig. 2d dargestellten Mehrschichtkörpers;

Fig. 2c

einen schematischen Schnitt einer dritten Fertigungsstufe des in Fig. 2d dargestellten Mehrschichtkörpers;

Fig. 2d

einen schematischen Schnitt eines nach einer zweiten Ausführungsform des erfindungsgemäßen Verfahrens hergestellten erfindungsgemäßen Mehrschichtkörpers;

Fig. 3a

einen schematischen Schnitt einer ersten Fertigungsstufe des in Fig. 3e dargestellten Mehrschichtkörpers;

Fig. 3b

einen schematischen Schnitt einer zweiten Fertigungsstufe des in Fig. 3e dargestellten Mehrschichtkörpers;

Fig. 3c

einen schematischen Schnitt einer dritten Fertigungsstufe des in Fig. 3e dargestellten Mehrschichtkörpers;

Fig. 3d

einen schematischen Schnitt einer vierten Fertigungsstufe des in Fig. 3e dargestellten Mehrschichtkörpers;

Fig. 3e

einen schematischen Schnitt eines nach einer dritten Ausführungsform des erfindungsgemäßen Verfahrens hergestellten erfindungsgemäßen Mehrschichtkörpers;

Fig. 4a

einen schematischen Schnitt einer ersten Fertigungsstufe des in Fig. 4d dargestellten Mehrschichtkörpers;

Fig. 4b

einen schematischen Schnitt einer zweiten Fertigungsstufe des in Fig. 4d dargestellten Mehrschichtkörpers;

Fig. 4c

einen schematischen Schnitt einer dritten Fertigungsstufe des in Fig. 4d dargestellten Mehrschichtkörpers;

Fig. 4d

einen schematischen Schnitt eines nach einer vierten Ausführungsform des erfindungsgemäßen Verfahrens hergestellten erfindungsgemäßen Mehrschichtkörpers;

The invention will be explained by way of example with reference to the drawings. Show it

Fig. 1a

a schematic section of a first manufacturing stage of in Fig. 1d illustrated multilayer body;

Fig. 1b

a schematic section of a second manufacturing stage of in Fig. 1d illustrated multilayer body;

Fig. 1c

a schematic section of a third manufacturing stage of in Fig. 1d illustrated multilayer body;

Fig. 1d

a schematic section of a multilayer body according to the invention produced according to a first embodiment of the method according to the invention;

Fig. 2a

a schematic section of a first manufacturing stage of in Fig. 2d illustrated multilayer body;

Fig. 2b

a schematic section of a second manufacturing stage of in Fig. 2d illustrated multilayer body;

Fig. 2c

a schematic section of a third manufacturing stage of in Fig. 2d illustrated multilayer body;

Fig. 2d

a schematic section of a multilayer body according to the invention produced according to a second embodiment of the method according to the invention;

Fig. 3a

a schematic section of a first manufacturing stage of in Fig. 3e illustrated multilayer body;

Fig. 3b

a schematic section of a second manufacturing stage of in Fig. 3e illustrated multilayer body;

Fig. 3c

a schematic section of a third manufacturing stage of in Fig. 3e illustrated multilayer body;

Fig. 3d

a schematic section of a fourth manufacturing stage of in Fig. 3e illustrated multilayer body;

Fig. 3e

a schematic section of a multilayer body according to the invention produced according to a third embodiment of the method according to the invention;

Fig. 4a

a schematic section of a first manufacturing stage of in Fig. 4d illustrated multilayer body;

Fig. 4b

a schematic section of a second manufacturing stage of in Fig. 4d illustrated multilayer body;

Fig. 4c

a schematic section of a third manufacturing stage of in Fig. 4d illustrated multilayer body;

Fig. 4d

a schematic section of a multilayer body according to the invention produced according to a fourth embodiment of the method according to the invention;

The Fig. 1a to 3e are each drawn schematically and not to scale to ensure a clear presentation of the essential features.

Fig. 1a shows an intermediate product 100a in the manufacture of a multilayer body 100, which in the finished state in Fig. 1d is shown.

The multi-layer body 100 after Fig. 1d comprises a carrier layer with a first side 11 and a second side 12.The carrier layer comprises a carrier film 1 and a functional layer 2. On the functional layer 2, a first decorative layer 3 is arranged, which is formed in a first zone 8 first lacquer layer 31 and a replicating layer 4 comprises. On the replication layer 4, a metal layer 5 is arranged in register with the first lacquer layer 3. On the metal layer 5, a second decorative layer 7 arranged in register with the metal layer 5 is provided. A compensation layer 10 fills height differences between the replication layer 4, the metal layer 5 and the second decorative layer 7.

The carrier film 1 is a preferably transparent plastic film having a thickness of between 8 μm and 125 μm, preferably in the range of 12 to 50 μm, more preferably in the range of 16 to 23 μm. The carrier film 1 may be formed as a mechanically and thermally stable film of a translucent material, for example of ABS (= acrylonitrile-butadiene-styrene), BOPP (= Biaxially Oriented Polypropylene), but preferably of PET. The carrier film 1 can hereby be monoaxially or biaxially stretched. Further, it is also possible that the carrier film 1 not only of a layer, but also consists of several layers. For example, it is possible for the carrier film 1 to have, in addition to a plastic carrier, for example a plastic film described above, a release layer which makes it possible to detach the layer structure consisting of the layers 2 to 6 and 10 from the plastic film, for example when using the multilayer body 100 as a hot stamping foil

The functional layer 2 may comprise a release layer, e.g. of heat-melting material, which facilitates detachment of the carrier film 1 from the layers of the multilayer body 100, which are arranged on a side of the release layer 2 facing away from the carrier film 1. This is particularly advantageous when the multilayer body 100 is formed as a transfer layer, as e.g. is used in a hot stamping process or an IMD process. Furthermore, it has proven useful, in particular if the multilayer body 100 is used as a transfer film, if the functional layer 2 contains, in addition to a release layer, a protective layer, e.g. a protective lacquer layer. After bonding the multilayer body 100 to a substrate and peeling off the carrier foil 1 from the layers of the multilayer body 100, which are arranged on a side of the peel layer 2 facing away from the carrier foil 1, the protective layer forms one of the upper layers on the surface of the substrate arranged layers and layers arranged below it from abrasion, damage, chemical attack, etc. protect. The multilayer body 100 may be a section of a transfer film, for example a hot stamping film, which may be disposed on a substrate by means of an adhesive layer. The adhesive layer is preferably arranged on the side of the compensation layer 10 facing away from the carrier film 1. The adhesive layer may be a hot melt adhesive which melts upon thermal exposure and bonds the multi-layer body 100 to the surface of the substrate.

On the functional layer 2, the transparent, colored lacquer layer 31 is printed in the zone 8. Transparent means that the lacquer layer 31 in the visible wavelength range is at least partially transparent to radiation. Colored means that the varnish layer 31 shows a visible color impression with sufficient daylight.

The lacquer layer 31 may in this case comprise a plurality of differently colored partial areas, such as in Fig. 1d indicated by different shading. As a result, a first motif can be provided. Next, the decorative layer 7, as in Fig. 1d indicated by different shades, forming different colored areas or areas with different optical properties, which in particular provide a second motif.

Both the zones 8 printed with the lacquer layer 31 and the unprinted zones 9 of the functional layer 2 are covered by a replication layer 4, which preferably has any relief structures of the decorative layer 3 which are present, i. the differing levels in the printed 8 and unprinted zones 9, equalized.

In the register and when viewed perpendicular to the plane of the carrier layer 1 congruent to the lacquer layer 31, a thin metal layer 5 is arranged on the replication 4. Coincident with the metal layer 5, a second decorative layer 7 is arranged. Both the zones 8 of the replication layer 4 covered with the metal layer 5 and the decorative layer 7 and the uncovered zones 9 of the replication layer 4 are covered with a compensating layer 10, the structures caused by the relief structures and the metal layer 5 arranged in some regions 8 (eg relief structure, different layer thicknesses) Height offset) equalized, ie covered and filled, so that the multi-layer body on the side facing away from the carrier film 1 side of the compensation layer 10 has a flat, substantially featureless surface.

If the compensation layer 10 has a similar refractive index as the replication layer 4, i. if the refractive index difference is less than about 0.15, then the zones of the relief structures in the replication layer 4 which are not covered by the metal layer 5 and are directly adjacent to the compensation layer 10 are optically extinguished because there are no optically detectable layer boundaries due to the similar refractive index of both layers between the replication layer 4 and the leveling layer 10 more are available.

The FIGS. 1a to 1c now show manufacturing stages of in Figure 1d shown multilayer body 100. Same elements as in Figure 1d are designated by the same reference numerals.

FIG. 1a shows a first manufacturing stage 100a of the multilayer body 100, in which the carrier film 1 on a first side 11 comprises a functional layer 2, on which in turn a decorative layer 3 is arranged. One side of the functional layer 2 is adjacent to the carrier film 1, its other side to the decorative layer 3. The decorative layer 3 has a first zone 8, in which a lacquer layer 31 is formed, and a second zone 9, in which the lacquer layer 31 is not present is on. The lacquer layer 31 is printed on the functional layer 2, for example by screen printing, gravure printing or offset printing. The formation of the lacquer layer 31 in regions (in the first zones 8) results in a pattern-like configuration of the decorative layer 3. It is also possible for the lacquer layer to consist of a plurality of partial layers overlapping each other in particular regions, which in particular have different optical properties, in particular colored differently. The lacquer layer 31 preferably has a layer thickness of 0.1 μm to 2 μm, more preferably of 0.3 μm to 1.5 μm.

A replication layer 4, which is a component of the first decorative layer 3, is applied to the functional layer 2 and the varnish layer 31 arranged in regions (in the zones 8). It can be an organic Layer applied by conventional coating methods, such as printing, casting or spraying, in liquid form. The order of the replication layer 4 is provided here over the entire surface. The layer thickness of the replication layer 4 varies, as it compensates for the different levels of the decorative layer 3 comprising the printed first zone 8 and the unprinted second zone 9; In the first zone 8, the layer thickness of the replication layer 4 is thinner than in the second zone 9, so that the side facing away from the carrier layer 1 side of the replication layer 4 before the formation of relief structures in a flat, substantially featureless surface.

The replication lacquer layer 9 preferably has a layer thickness of 0.1 μm to 3 μm, more preferably of 0.1 μm to 1.5 μm.

However, an application of the replication layer 4 may also be provided only in a partial region of the multilayer body 100. The surface of the replication layer 4 can be structured in regions by known methods. For this purpose, for example, as a replication 4, a thermoplastic Replizierlack applied by printing, spraying or painting and molded a relief structure in the particular thermally curable / dry replicate 4 by means of a heated punch or a heated replicating roller. The replication layer 4 can also be a UV-curable replication lacquer which is structured, for example, by a replication roller and cured simultaneously and / or subsequently by means of UV radiation. However, the structuring can also be produced by UV irradiation through an exposure mask.

On the replication 4, the metal layer 5 is applied. The metal layer 5 may be formed, for example, as a vapor-deposited metal layer, for example of silver or aluminum. The order of the metal layer is provided here over the entire surface. However, an application may also be provided only in a partial region of the multilayer body 100, for example with the aid of a partially shielding vapor deposition mask.

The metal layer preferably has a layer thickness of 20 nm to 70 nm.

On the metal layer 5, a photoactivatable resist layer 6 is applied. The resist layer 6 is formed in the present embodiment as a positive resist (release of the activated = exposed areas). The resist layer 6 may be an organic layer which is applied in a liquid form by classical coating methods such as printing, casting or spraying. It can also be provided that the resist layer 6 is vapor-deposited or laminated as a dry film.

In the photoactivatable layer 6 can be, for example, a positive photoresist AZ Clariant or act of MICROPOSIT ^® S1818 from Shipley 1512 in which a surface density of 0.1 g / m ² to 10 g / m ^2, preferably from 0.1 g / m ² to 1 g / m ^{2 is} applied to the layer 5 to be structured. The layer thickness depends on the desired resolution and the process. The order is provided here over the entire area. However, an application may also be provided only in a partial area of the multilayer body 100.

FIG. 1b shows a second manufacturing stage 100b of the multi-layer body 100, in which the first manufacturing stage 100a of the multi-layer body 100 was irradiated and then developed. Electromagnetic radiation having a wavelength which is suitable for activating the photoactivatable resist layer 6 is produced from the second side 12 of the carrier film 1, ie the side of the carrier film 1 which lies opposite the side of the carrier film 1 coated with the resist layer 6, through the multilayer body 100d blasted. The irradiation serves to activate the photoactivatable resist layer 6 in the second zone 9, in which the decorative layer 3 has a higher transmittance than in the first zone 8. The intensity and duration of the exposure to the electromagnetic radiation is coordinated with the multilayer body 100a such that the radiation in the second zone 9 activates the multilayer body 100a photoactivatable resist layer 6 leads, however, does not lead to activation of the photoactivatable resist layer 6 in the printed with the resist layer 31 first zone 8. It has proven useful if the contrast between the first zone 8 and the second zone 9 caused by the lacquer layer 31 is greater than two. Furthermore, it has proven useful if the lacquer layer 31 are configured such that the radiation after passing through the entire multi-layer body 100a has a ratio of the transmittances, ie a contrast ratio of approximately 1: 2 between the first zone 8 and the second zone 9.

The exposure is preferably carried out with an illuminance of 100 mW / cm ² to 500 mW / cm ² , preferably from 150 mW / cm ² to 350 mW / cm ² .

For developing the exposed resist layer 6, a developer solution, e.g. As solvents or alkalis, in particular a sodium carbonate solution or a sodium hydroxide solution applied to the side facing away from the carrier film 1 surface of the exposed photoactivatable resist layer 6. As a result, the exposed resist layer 6 in the second zone 9 has been removed. In the first zone 8, the resist layer 6 is obtained because the amount of radiation absorbed in these zones has not led to sufficient activation. As already mentioned, is in the in the FIG. 1a illustrated embodiment, the resist layer 6 thus formed of a positive photoresist. In such a photoresist, the more exposed zones 9 are soluble in the developer solution, eg the solvent. In contrast, in a negative photoresist, the unexposed or less exposed zones 8 are soluble in the developer solution.

Subsequently, the metal layer 5 in the second zone 9 is removed by an etchant. This is possible because, in the second zone 9, the metal layer 5 is not protected from attack by the etchant by the developed resist layer 6 serving as an etching mask. The etchant may be, for example, an acid or alkali, for example NaOH (sodium hydroxide). or Na ₂ CO ₃ (sodium carbonate) in a concentration of 0.05% to 5%, preferably from 0.3% to 3%. In this way, the in FIG. 1b shown portions of the metal layer 5 is formed.

In the next step, the remaining areas of the resist layer 6 are also removed ("stripping").

In this way, therefore, the metal layer 5 can be structured in register with the first and second zones 8 and 9 defined by the lacquer layer 31 without additional technological effort. In conventional methods of forming an etch mask by mask exposure, the mask being formed either as a separate unit, e.g. is present as a separate film or as a separate glass plate / glass roller, or as a subsequently printed layer, the problem arises that by previous, in particular thermally and / or mechanically consuming process steps, e.g. when generating a replication structure in the replication layer 4, caused linear and / or non-linear distortions in the multilayer body 100 can not be fully compensated over the entire surface of the multilayer body 100, although the mask alignment on existing (usually at the horizontal and / or vertical edges of the multilayer body arranged) register or registration marks. The tolerance fluctuates over the entire surface of the multi-layer body 100 in a relatively large area.

Thus, the first and second zones 8 and 9 defined by the lacquer layer 31 are used as a mask, wherein the lacquer layer 31 is applied in an early process step in the production of the multilayer body 100 as described above. As a result, no additional tolerances and no additional tolerance fluctuations over the surface of the multi-layer body 100 occur, since the subsequent generation of a mask and thereby required register-accurate subsequent positioning of this independent of the previous process mask is avoided. The tolerances or register accuracies in the method according to the invention lie only in the not absolutely exact course of the color edge of the defined by the lacquer layer 31 first and second zones 8 and 9 whose quality is determined by the particular printing method used, and are approximately in the micrometer range, and thus far below the resolution of the eye; ie the unarmed human eye can no longer perceive existing tolerances.

The next, in Fig. 1c represented intermediate product 100c is obtained from the intermediate product 100b by a further, second decorative layer 7 on the covered by the structured layer 5 zones 8 and on the not covered by the structured layer 5 zones 9 of the replication layer 4, in particular partially applied. The second decorative layer 7 comprises at least one second photoactivatable resist layer. Preferably, the second decorative layer 7 has two or more, in particular differently colored second resist layers. The second resist layers can also be printed in pattern form here. The second resist layers may also have a multilayer structure. The second resist layers may also be partially colorless transparent or translucent, ie have no coloration.

As with the first resist layer 6 may be in the second resist layer, for example, a positive photoresist AZ 1512 from Clariant or MICROPOSIT ^® S1818 from Shipley act, which in a surface density of 0.1 g / m ² to 10 g / m ^2, preferably from 0.5 g / m ² to 1 g / m ^{2 is} applied. The order is provided here over the entire area. However, an application may also be provided only in a partial area of the multilayer body 100. Since the second decorative layer 7 should at least partially be retained in the finished multi-layer body 100, dyes, pigments, nanoparticles or the like may additionally be incorporated into the lacquer in order to achieve an optical effect.

The second decorative layer 7 is now also exposed from the side 12 of the carrier layer 1, for which purpose the parameters already described during the exposure of the first resist layer 6 can be used. During the exposure of Second decor layer 7 now the lacquer layer 31 and the metal layer 5 act together as a mask, so that the at least one resist layer of the second decorative layer 7 is exposed only in the zone 9, while the area covered by lacquer layer 31 and structured layer 5 remains unexposed. As well as the first resist layer 6, the second decorative layer 7 for developing with a developer solution, for. B. an alkali, in particular a sodium carbonate solution or a sodium hydroxide solution. As a result, the exposed resist layer of the second decorative layer 7 in the second zone 9 is removed. In the first zone 8, the second resist layer is retained because the amount of radiation absorbed in these zones has not led to sufficient activation. When using a negative resist, this reverses as already described, so that the second resist layer is removed in the first zone 8 and is retained in the second zone 9.

The in Figure 1d shown multilayer body 100 is made of the in FIG. 1 c illustrated manufacturing stage 100c of the multilayer body 100 formed by a compensation layer 10 on the arranged in the first zone 8, exposed second decorative layer 7 and on the disposed in the second zone 9, by removing the metal layer 5 and the first 6 and second resist layer exposed replication layer 4 is applied. The order of the leveling layer 10 is provided here over the entire surface.

The compensating layer used is in particular a UV-crosslinked or heat-crosslinked lacquer.

It is possible that the compensating layer 10 is applied in the first zone 8 and the second zone 9 in each case in a different layer thickness, for example by knife coating, printing or spraying, so that the leveling layer 10 on its side facing away from the carrier layer 1 a flat, having substantially structureless surface. The layer thickness of the compensating layer 10 varies because it varies the levels of the metal layer 5 arranged in the first zone 8 and that exposed in the second zone 9 Replicating 4 compensated / equalized. In the second zone 9, the layer thickness of the compensation layer 10 is greater than the layer thickness of the metal layer 5 is selected in the first zone 8, so that the side facing away from the carrier layer 1 side of the compensation layer 10 has a flat surface. However, an application of the compensating layer 10 may also be provided only in a partial region of the multilayer body 100. It is possible for one or more further layers, for example an adhesion or adhesive layer, to be applied to the planar compensation layer 10.

With the described method, therefore, the first and second zones 8 and 9 defined by the lacquer layer 31 and by the metal layer 5 are used as a mask for structuring the second decorative layer 7. As a result, no additional tolerances and no additional tolerance fluctuations over the surface of the multi-layer body 100 occur, since the subsequent generation of a mask and thereby required register-accurate subsequent positioning of this independent of the previous process mask is avoided. Thus, a multi-layer body 100 is obtained, in which the lacquer layer 31 of the decorative layer 3, the metal layer 5 and the second decorative layer 7 are arranged in the perfect register.

Fig. 2d shows another multilayer body 200, which is produced by a variant of the method. The process steps and intermediates 200a, 200b and 200c are in the FIGS. 2a to 2c shown. The further multi-layer body 200 corresponds to the in Figure 1d Therefore, the same reference numerals are used for the same structures and functional elements.

The multilayer body 200 also comprises a carrier layer with a first side 11 and a second side 12. The carrier layer comprises a carrier foil 1 and a functional layer 2. On the functional layer 2 a first decorative layer 3 is arranged, which is formed by a replication layer 4. Alternatively, the decorative layer 3 may be formed of a plurality of layers and, for example, a colored layer and have a replication layer. On the replication layer 4, a metal layer 5 is arranged. On the metal layer 5, a second decorative layer 7 arranged in register with the metal layer 5 is provided. An equalization layer 10 fills height differences between the replication layer 4, the metal layer 5 and the second decoration layer 7. The materials and application methods already described with reference to the multilayer body 100 can be used for the individual layers.

The multi-layer body 200 differs from the multi-layer body 100 only in that the decorative layer 3 does not have separate lacquer areas 31, but is formed entirely from a colored replication lacquer which may contain dyes, pigments, UV-activatable substances, nanoparticles or the like or alternatively completely from one correspondingly colored lacquer layer and a transparent colorless Replizierlack is formed.

In the production of the multilayer body 200, the in FIG. 2a shown intermediate 200a provided. Analogously to the production of the multi-layer body 100, firstly a carrier foil 1 is provided with a functional layer 2 onto which the decor layer 3 is applied over the whole area. As already described, reliefs, for example diffractive structures, can additionally be introduced into the replication layer 4 of the decorative layer 3. The replication layer 4 is then metallized over the entire surface in the manner already described. On the thus obtained metallic, to be structured layer 5 now one or more, also differently colored resist layers comprising second decorative layer 7 is printed over part of the area, so that in the zone 8, the metal layer 5 is protected by the second decorative layer 7, while in the zone. 9 the metal layer 5 is not covered by the second decorative layer 7. To produce the desired optical effects, the second decorative layer 7 comprises layers, in particular resist layers, which may contain dyes, pigments, UV-activatable substances, nanoparticles or the like. The second decorative layer 7 may be formed, for example, from a PVC-based paint.

To do that in Fig. 2b shown intermediate product 200b, the intermediate product 200a of the multilayer body 200 is now treated with an etchant, in particular a sodium carbonate solution or a sodium hydroxide solution, which is applied to the side facing away from the carrier film 1 surface of the intermediate product 200a. While the zone 8 are protected by the second decorative layer 7 from the action, the liquor can dissolve the metal layer 5 in the zone 9, so that the metal layer 5 is removed in the zone 9. In this way it can be achieved that the metal layer 5 is formed in the perfect register to the second decorative layer 7. The second decorative layer 7 thus acts as an etch resist here.

The intermediate product 200b is subsequently treated with a solvent, which should preferably have a flash point of more than 65 ° C. The solvent is chosen so that the second decorative layer 7 is insensitive to the solvent, while the material of the replication layer 4 can dissolve in the solvent.

Suitable paints, in particular for the replication varnish 4, which have these properties are, for example, polyacrylates or polyacrylates in combination with cellulose derivatives.

In zone 8, however, the replication layer is protected by attack of the solvent by the metal layer 5 and the second decorative layer 7, so that the replication layer 4 dissolves only in the unprotected zone 9. As a result, the in Fig. 2c obtained intermediate 200c.

Finally, in order to obtain the finished multi-layer body 200, an equalization layer 10 is applied which compensates any existing relief structures in the replication layer 4, as well as the removed zones 9 of the replication layer 4 and the metal layer 5, so that a smooth surface of the multi-layer body 200 results. As with the multilayer body Of course, even more functional layers or the like can be applied.

In contrast to the method described above, therefore, no exposure is necessary here in order to obtain a register-containing arrangement of three layers (first decorative layer 3, metal layer 5)
and second decorative layer 7). The resolution of the structures produced is limited only by the achievable when printing the second decorative layer 7 resolution and the lateral diffusion of the liquor or the solvent in the corresponding process steps.

Fig. 3e shows a further multi-layer body 300, which is produced by a variant of the method. The process steps and intermediates 300a, 300b, 300c and 300d are in the FIGS. 3a to 3d shown. The further multi-layer body 300 also corresponds to the in Fig. 1d and Fig. 2d shown multilayer bodies 100 and 200. For the same structures and functional elements, therefore, the same reference numerals are used.

The multilayer body 300 also comprises a carrier layer with a first side 11 and a second side 12, which comprises a carrier foil 1 and a functional layer 2. On this a replication layer 4 is arranged, which is colored and at the same time acts as a first decorative layer 3. Alternatively, the decorative layer 3 may also be multi-layered and, for example, have a colored layer and a replication layer. On the replication layer 4, a metal layer 5 in register with the first decorative layer 3 and a second decorative layer 7 arranged in register with the metal layer 5 are provided. Height differences of the replication layer 4, the metal layer 5 and the second decorative layer 7 are filled by a leveling layer 10.

For the individual layers, the materials and application methods already described with reference to the multilayer body 100 can be used. Like the multi-layer body 200, the same differs Multi-layer body 300 of the multi-layer body 100 only in that the decorative layer 3 does not have separate lacquer areas 31, but is formed entirely from a colored replicate lacquer which may contain dyes, pigments, UV-activatable substances, nanoparticles or the like, or alternatively completely from a suitably colored lacquer layer and a transparent colorless replicate varnish is formed.

Fig. 3a shows a first intermediate product 300a in the production of the multi-layer body 300 according to a variant of the method. Analogously to the production of the multi-layer bodies 100 and 200, a carrier foil 1 is first provided with a functional layer 2 on which the decor layer 3 is applied over the whole area. As already described, reliefs, for example diffractive structures, can additionally be introduced into the replication layer 4 of the decorative layer 3. The replication layer 4 is then metallized over the entire surface in the manner already described. On the metal layer 5 thus obtained, a resist 6 is now applied over the entire surface.

On the side facing away from the carrier sheet 1 of the resist 6, a mask 13 is now placed. In contrast to the method described in the production of the multilayer body 100, however, the mask 13 here is a separate part, ie it is not formed by structures of the multilayer body 300 itself. The mask includes zones 8 that are opaque to the electromagnetic radiation used to expose the photoactivatable resist 6, and zones 9 that are transparent to said radiation. Since the mask 13 is arranged on the side of the resist 6 facing away from the carrier film 1, the exposure of the resist 6 must likewise take place from this side, ie it can not take place from the side of the carrier film 1, as in the production of the multilayer body 100. However, all further parameters of the exposure and subsequent development of the resist 6 correspond to the method explained with reference to the production of the multilayer body 100. After the exposure of the resist 6, the mask 13 can be removed, and in the manner already described Resist 6 will be developed. Subsequently, the metal layer 5 is patterned by an etchant in the manner already described.

In the example shown, a combination of a positive resist 6 with a positive mask 13 is used. The resist 6 is therefore protected in the zone 8 by the mask and exposed only in the zone 9. In the zone 9, the resist 6 is thus removed during the development, so that the metal layer 5 is exposed in the zone 5 and is removed by the etchant in the subsequent etching step. Of course, a negative mask can also be used in combination with a negative resist.

After etching, the in Fig. 3b obtained intermediate product 300b, in which the structured layer is present only in the zones 8, while in the zones 9, the replication layer 4 is exposed. In addition, in the zones 8, the resist 6 is still present on the surface of the metal layer 5 facing away from the carrier foil 1.

To obtain from the intermediate 300b the in Fig. 3c to obtain the intermediate product 300c, the resist 6 is removed by solvent treatment ("stripped"). For this purpose, the comments to Fig. 2c and 2d directed. This can also be done in the manner already described in the production of the multilayer body 100. When removing the resist 6, the replication layer 4 in the zone 9, in which it is not protected by the metal layer 5, is removed at the same time.

In the next method step, a second decorative layer 7 is then applied over the entire surface of the metal layer 5 or the exposed zones 9 of the functional layer 2, so that the in Fig. 3d shown intermediate 300d is obtained. The second decorative layer 7 comprises at least one layer of a photoactivatable resist, preferably two or more photoactivatable, differently colored layers, and at the same time acts as a leveling layer, which compensates the height differences due to the partial removal the metal layer 5 and the replication layer 4 compensates. As with the multi-layer body 100, the second decorative layer 7 remains partially in the finished multi-layer body and assumes an optical function there. The second decorative layer 7 therefore comprises at least one layer dyed with dyes, pigments, UV-active substances, nanoparticles or the like.

In the intermediate product 300d, the zone 8 formed by the remaining decorative layer 3 and the metal layer 5 is intransparent for the electromagnetic radiation used to expose the resist of the second decorative layer 7. Analogously to the production of the multilayer body 100, an exposure of the resist of the second decorative layer 7 can now be carried out from the side of the carrier film and the resist can subsequently be developed in the manner already described. Since the remaining decorative layer 3 acts together with the metal layer 5 as a mask, the resist is thus exposed only in the zone 9. When using a positive resist, the resist is thus removed in the zone 9 during development, so that it remains only where it rests directly on the metal layer 5.

In order to arrive at the finished multi-layer body 300, the zone 9, in which the resist of the second decorative layer 7 has been removed, is provided with a leveling layer 10 in order to compensate for the height differences. Optionally, a crosslinked, transparent sealing layer 14 can also be applied to the side of the multilayer body 300 facing away from the carrier film 1 in order to protect its surface against mechanical damage.

With this method, therefore, a structure of three register-accurate layers, namely the first decorative layer 3, the metal layer 5 and the second decorative layer 7 is obtained. Since an external mask is used only for structuring the metal layer 5, which then serves as a mask for removing the replication layer in the zone 8 or for exposing the resist of the second decorative layer 7 in the zone 8, the problems described at the outset occur the use of masks does not occur here. The remaining zones 8 of the first decorative layer 3 and the second decorative layer 7 necessarily arise with exact raster to the metal layer. 5

Fig. 4d shows a further multi-layer body 400, which is produced by a variant of the method. The process steps and intermediates 400a, 400b and 400c are in the FIGS. 4a to 4c shown.

The multilayer body 400 is different from that in FIG Fig. 1a shown multi-layer body 100 only in that the second decorative layer 7 is formed in a first portion of a photoactivatable resist layer and in a second portion of a partially applied etching resist layer. In the second subarea, the decorative layer 3 may have first zones 8 and / or second zones 9 as well as in the first subarea.

In the first subregion, the structure of the multilayer body 400 corresponds to the multilayer body 100 in FIGS Fig. 1a to 1d and the method steps described there are also carried out in order to produce a multilayer body 400, as described in US Pat Fig. 4d shown in the first section. Deviating from the multi-layer body 100, the second subarea is now provided in which, instead of the photoactivatable resist layer 6, an etching resist layer 15 is partially applied. The motif or the external shape of the etching resist layer 15 is intended to determine the motif or the external shape of the partial metallization to be achieved. The etching resist layer 15 may for example consist of a PVC-based lacquer and be colored by means of pigments and / or dyes or be colorless transparent or translucent.

After developing the photoactivatable resist layer, the metal layer 5 in the second zone 9 is removed by an etchant. This is possible because, in the second zone 9, the metal layer 5 is not protected by the developed resist layer 6 in the first subarea as the etching mask and also by the etching resist layer 15 in the second subarea before the attack the etchant is protected. The etchant may be, for example, an acid or alkali, for example NaOH (sodium hydroxide) or Na ₂ CO ₃ (sodium carbonate) in a concentration of 0.05% to 5%, preferably of 0.3% to 3%. In this way, the in FIG. 4b shown portions of the metal layer 5 is formed.

In the next step, the remaining areas of the resist layer 6 are also removed ("stripping"). In this case, however, the etching resist layer 15 is maintained on the metal layer 5.

In this way, therefore, the metal layer 5 can be structured in register with the first and second zones 8 and 9 defined by the lacquer layer 31 without additional technological effort in the first partial area and in register with the etching resist layer 15 in the second partial area.

As in Fig. 1c will now be in Fig. 4c in the first subregion, a further, second decorative layer 7 is applied to the zones 8 covered by the structured layer 5 and to the zones 9 of the replication layer 4 not covered by the structured layer 5. The second decorative layer 7 comprises at least one second photoactivatable resist layer. Preferably, the second decorative layer 7 has two or more, in particular differently colored second resist layers. The second resist layers can also be printed in pattern form here. The etching resist layer 15 still present in the second subregion likewise forms a part of the decorative layer 7.

Alternatively, the application of the decorative layer 7 in the first portion may also be omitted, so that in the first portion of the metal layer 5 is present without coating and in the second portion with the applied etching resist layer 15. Thus, for example, a coloring of the metal layer 5 by means of colored etching resist layer 15th take place only in the second subarea and in the first subregion, the metal layer 5 is true to register the first Decorative layer before, however, is not colored on the side facing away from the first decorative layer and in the case of aluminum silver glossy reflective.

As regards Fig. 1c and 1d described, the decorative layer 7 is exposed in the first part, developed and partially removed.

As in Fig. 1d is also shown at the in FIG. 4d shown multi-layer body 400 from the in Figure 4c in that a leveling layer 10 is formed on the exposed second decorative layer 7 arranged in the first zone 8 as well as on the replication layer 4 arranged in the second zone 9 and exposed by removing the metal layer 5 and the first 6 and second resist layers is applied. The order of the leveling layer 10 is provided here over the entire surface. The leveling layer 10 may be single or multi-layered or omitted. It is possible for a bonding layer (adhesive layer) (not shown here) to be applied to the side of the leveling layer 10 facing away from the carrier layer, which may also have a multilayer structure.

LIST OF REFERENCE NUMBERS

1

support film

2

functional layer

3

first decor layer

4

replication

5

metal layer

6

resist layer

7

second decor layer

8th

first zone

9

second zone

10

leveling layer

11

first page

12

second page

13

mask

14

sealing layer

15

etching resist

31

first lacquer layer (of 3)

32

second paint layer (from 3)

100

Multi-layer body

200

Multi-layer body

300

Multi-layer body

400

Multi-layer body

Claims (15)

1. Method for the production of a multilayer body (100, 200, 300), in particular an optical security element or an optical decorative element, wherein in the method:

   a) a monolayer or multilayer first decorative layer (3) is applied to a carrier layer;

   b) at least one metal layer (5) is applied to the side of the first decorative layer (3) which is facing away from the carrier layer;

   c) the at least one metal layer (5) is structured in such a way that the metal layer (5) is provided in one or more first zones (8) of the multilayer body (100, 200, 300) in a first layer thickness and is provided in one or more second zones (9) of the multilayer body (100, 200, 300) in a second layer thickness which is different from the first layer thickness, wherein, in particular, the second layer thickness is equal to zero;

   d) a monolayer or multilayer second decorative layer (7) is applied to the side of the metal layer (5) which is facing away from the first decorative layer (3); characterised in that

   e) the first and/or second decorative layer (7) using the metal layer (5) as a mask is structured in a first region of the multilayer body in such a way that the first (3) or second decorative layer (7) is at least partially removed in the first (8) or second (9) zones.
2. Method according to claim 1,
   characterised in that
   the first (3) and the second decorative layers(7) using the metal layer (5) as a mask are structured in the first region in such a way that the first (3) and second decorative layers(7) are both at least partially removed in the first (8) or second zones (9) or the metal layer (5) using the first (3) or second decorative layer (7) is structured as a mask.
3. Method according to claim 1 or 2,
   characterised in that,
   in step c), a first resist layer (6), which is able to be activated by means of electromagnetic radiation, is applied to the side of the metal layer (5) which is facing away from the first decorative layer (3), and the first resist layer (6) using the exposure mask is exposed by means of said electromagnetic radiation.
4. Method according to claim 3,
   characterised in that
   the second decorative layer (7) comprises one or more second coloured resist layers which are able to be activated by means of electromagnetic radiation and in step e), the one or more second coloured resist layers are exposed by means of said electromagnetic radiation from the side of the carrier layer, wherein the metal layer (5) serves as an exposure mask, wherein the one or more second coloured resist layers comprise, in particular, at least two different colouring agents or resist layers containing colouring agents in different concentrations, and wherein, in particular, one or more of the one or more second coloured resist layers are applied in a pattern by means of a printing method, and, in particular, form a first design.
5. Method according to one of claims 3 or 4,
   characterised in that
   the first resist layer (6) in step c) is exposed from sides of the carrier layer, wherein the mask is formed to expose the first resist layer (6) through the first decorative layer (3), wherein the first decorative layer (3),seen perpendicularly to the plane of the carrier layer, in the first region in the one or more first zones (8), has a first transmission factor and in the one or more second zones (9) has a second transmission factor which is larger than the first transmission factor, wherein said transmission factors relate to electromagnetic radiation with a wavelength which is suitable for photoactivation of the first resist layer (6).
6. Method according to claim 5,
   characterised in that
   the first decorative layer (3) comprises one or more, in particular coloured, first lacquer layers which are arranged in the first region in the one or more first zones (8) with a first layer thickness and in the one or more second zones (9) either without or with a second layer thickness which is smaller than the first layer thickness such that the first decorative layer (3) in particular in the first region in the one or more first zones (8) has said first transmission factor and in the one or more second zones (9) has said second transmission factor, wherein the one or more first lacquer layers are applied in a pattern in particular by means of a printing method.
7. Method according to one of claims 3 or 4,
   characterised in that
   the first resist layer (6) in step c) is exposed from the side facing away from the carrier layer, wherein, in order to expose the first resist layer (6), a mask (13) is arranged between the first resist layer (6) and a light source which is used for exposure, wherein the mask, seen perpendicularly to the plane of the carrier layer, in the first region in the one or more first zones (8) has a first transmission factor and in the one or more second zones (9) has a second transmission factor which is larger than the first transmission factor, wherein said transmission factors relate to electromagnetic radiation with a wavelength which is suitable for photoactivation of the first resist layer (6).
8. Method according to claim 1 or 2,
   characterised in that
   step c) to step d) are carried out and in step c), the metal layer (5) using the second decorative layer (7) is structured as a mask, in particular by applying an etching agent and removing the regions of the metal layer (5) which are not protected by the mask, and in step e), the first decorative layer (3) using the metal layer (5) as a mask is structured, in particular, by applying a solvent and removing the regions of the decorative layer (3) which are not protected by the mask.
9. Method according to one of the preceding claims,
   characterised in that
   the first (3) and/or second (7) decorative layer comprises a replication lacquer layer into which a surface relief is moulded, and/or a surface relief is moulded into the surface of the carrier layer facing towards the first decorative layer (3), said surface relief in particular comprising a diffractive structure, in particular comprising a hologram, a kinegram®, a linear grid or a cross grid, a zero-order diffraction structure or a blazed grating, comprising a refractive structure, in particular comprising a microlens array or a retroreflective structure, an optical lens or a freeform surface structure, and/or comprising a matt structure, in particular comprising an isotropic or anisotropic matt structure.
10. Multilayer body (100, 200, 300, 400), in particular produced according to a method according to one of the preceding claims, having a monolayer or multilayer first decorative layer (3), a monolayer or multilayer second decorative layer (7) and at least one metal layer (5) which is arranged between the first (3) and second decorative layer (7), wherein the metal layer (5) is structured in such a way that the at least one metal layer (5) is provided in a first region of the multilayer body (100, 200, 300) in one or more first zones (8) of the multilayer body (100, 200, 300) in a first layer thickness and in one or more second zones (9) of the multilayer body (100, 200, 300) in a second layer thickness which is different from the first layer thickness, wherein, in particular, the second layer thickness is equal to zero, and wherein the first and second decorative layers (7) are structured congruently with respect to each other as well as with respect to the metal layer (5), in particular in such a way that the first (3) and second decorative layers (7) in the first region in the first (8) or second zones (9) are at least partially removed congruently with respect to each other as well as with respect to the metal layer (5).
11. Multilayer body (100, 200, 300, 400) according to claim 10,
    characterised in that
    the multilayer body (100, 200, 300) comprises an in particular full-surface carrier layer, wherein, in particular, the first decorative layer (3), seen perpendicularly to the plane of the carrier layer, in the first region in the first zones (8) has a first transmission factor and in the second zones (9) has a second transmission factor which is larger than the first transmission factor, wherein said transmission factors relate to electromagnetic radiation in the visual and/or ultraviolet and/or infrared spectrum.
12. Multilayer body (100, 200, 300, 400) according to claim 11,
    characterised in that
    the second decorative layer (7) in the first zone (8) or the second zone (9) has at least one resist layer which is photoactivated by means of said electromagnetic radiation, wherein the at least one metal layer (5) and the resist layer are arranged to align precisely with each other on the first side (11) of the carrier layer in such a way that the resist layer is arranged on the side of the at least one metal layer (5) which is facing away from the carrier layer and the first decorative layer (3) is arranged on the other side of the at least one metal layer (5).
13. Multilayer body (100, 200, 300, 400) according to one of claims 10 to 12,
    characterised in that
    the first (3) and/or second decorative layer (3) comprises one or more layers which are coloured with at least one colouring agent which is yellow, magenta, cyan or black (CMYK) or which is red, green or blue (RGB), and/or is provided with at least one red and/or green and/or blue fluorescent pigment or colouring agent which can be activated by radiation and thereby produces an additive colour during radiation, and/or which are coloured with at least one opaque and/or at least one transparent colouring agent which is coloured or produces colour at least in one wavelength range of the electromagnetic spectrum, in particular is multi-coloured or produces multiple colours, in particular a colouring agent is contained in one or more of the layering first (3) and/or second decorative layers (7) which can be activated outside the visible spectrum and produce a visually recognisable coloured impression.
14. Multilayer body (100, 200, 300, 400) according to one of claims 10 to 13,
    characterised in that
    the first (3) and/or second decorative layer (7) comprises a replication lacquer layer into which a surface relief comprising at least one relief structure is moulded and the at least one metal layer (5) is arranged on the surface of the at least one relief structure, wherein, in particular, the at least one relief structure is arranged at least partially in the first zones (8) and/or in the second zones (9), in particular congruently to the first (8) or second zones (9).
15. Multilayer body (100, 200, 300, 400) according to one of claims 10 to 14,
    characterised in that
    recesses of the first (3) and/or second decorative layer (7) and/or the at least one metal layer (5) are filled with a compensation layer (10), wherein, in particular, the refractive index of the compensation layer (10) in the visible wavelength range is in the range from 90% to 110% of the refractive index of the replication lacquer layer (4), and/or wherein the compensation layer (10) is formed as an adhesive layer.

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