WO2021244842A1

WO2021244842A1 - Method for producing a multilayer body, and multilayer body

Info

Publication number: WO2021244842A1
Application number: PCT/EP2021/062986
Authority: WO
Inventors: Violetta Olszowka; Benjamin HASSE
Original assignee: Leonhard Kurz Stiftung & Co. Kg
Priority date: 2020-06-05
Filing date: 2021-05-17
Publication date: 2021-12-09
Also published as: DE102020114967A1; EP4161782A1

Abstract

The invention relates to a method for producing a multilayer body (40) and to a multilayer body. The method for producing a multilayer body comprises the following steps: - providing at least one base film (20); - providing at least one transfer film; - applying at least partially at least one transfer layer (10) of the transfer film onto and/or under the base film (20). The multilayer body (40) comprises at least one base film (20) and at least one transfer layer (10) of a transfer film, which is applied onto and/or under the base film (20).

Description

Method for producing a multilayer body and a

Multilayer body

The invention relates to a method for producing a multi-layer body and a multi-layer body.

To protect security documents against forgeries, these are often provided with security elements which enable the authenticity of the security document to be checked and offer protection against a replica of the security document. In this context, it is known from EP 1953002 A2, for example, to connect a security thread with microlenses by means of adhesive layers to the carrier body of the document of value during production, so that the optical effect of the microlenses is retained. For this purpose, areas are provided in which only the microlenses are present and further areas in which only the adhesive layer is present. When using such security elements on documents of value, however, there is the problem of realizing further optical effects in addition to the microimages.

The invention is now based on the object of providing a method for producing an improved multi-layer body and an improved multi-layer body which conveys an improved optically variable impression and additionally increases the security against forgery. The object is achieved by a method for producing a multilayer body, preferably a security element, particularly preferably a document of value, the method comprising the following steps, which are carried out in the following order in particular:

- providing at least one base film;

- Providing at least one transfer film;

- At least partial application of at least one transfer layer of the transfer film on and / or under the base film.

Such a multi-layer body is preferably produced by the above method, in particular by a method according to one of claims 1 to 50, so that the multi-layer body has at least one base film and at least one transfer layer of a transfer film applied on and / or under the base film.

It has been shown here that the method according to the invention for producing a multi-layer body and the multi-layer body according to the invention result in a multi-layer body with optically appealing effects by means of the combination of microlenses and microimages and further optical effects that are different from the effects of the combination of microlenses and microimages, is obtained. Furthermore, a multilayer body is obtained in which a microlens / microimage element can be combined with a different optical effect, for example a kinegram, with a few process steps. At the same time, this minimizes scrap and reduces material loss. The fact that the transfer layer is applied on and / or under the base film enables a wide range of design variations that produce a special optical effect.

Further advantageous refinements of the invention are specified in the subclaims. It is advantageous if the at least one base film has a transparent first layer in which a multiplicity of microlenses are molded in a first area, which are arranged according to a microlens grid, and has a second layer arranged below the first layer, which has a multiplicity of microimages, which are arranged in accordance with a microimage grid and each in an at least regionally overlapping manner with one of the microlenses of the microlens grid for generating a first optically variable item of information. Such an arrangement produces interesting optically variable effects for the human observer when viewing the multilayer body from the front side, ie from the side of the first layer facing away from the second layer, when the multilayer body is tilted.

Here, microimages are preferably understood to mean complete motifs and also incomplete motifs, that is to say fragments of motifs. A motif can be selected from: image, symbol, logo, coat of arms, portrait, alphanumeric characters and / or combinations thereof.

It is preferably possible that the first optically variable information has at least one element selected from: a graphically designed outline, a figurative representation, an image, a single image, a pattern, an endless pattern, a motif, a symbol, a logo, a Portrait, a grid, an alphanumeric character, a text and / or combinations thereof.

It is also possible for the first layer to be formed as a replication layer with a layer thickness in the range from 0.1 μm to 30 μm, preferably from 0.3 μm to 20 μm.

A replication layer is preferably understood here to mean a special, functional layer into which optically variable structures are introduced and / or fixed, in particular by means of thermal replication and / or UV replication. In the case of a hybrid replication layer, this is, for example, thermal replicated and then cured by means of radiation, for example by means of UV radiation and / or at least one electron beam. In the case of a UV-based replication layer, this is replicated at room temperature and then cured by means of radiation, for example by means of UV radiation and / or at least one electron beam. It is possible, for example, that the lacquer increases its temperature during UV replication.

Furthermore, it is preferably provided that the grid widths of the micro-image grid and of the microlens grid are each less than 300 μm in at least one spatial direction. This ensures that the individual components of the micro-image grid and the microlens grid can no longer be resolved by the unarmed human eye, which creates a particularly harmonious optical effect for the viewer.

It is also particularly advantageous if the respective grid width of the microlens grid in a first spatial direction is at least 50%, in particular more than 100% greater than the respective dimension of the respective microlens in the first spatial direction.

The raster width of the microlens grid is understood to mean the respective microlens spacing of the respective microlens from its neighboring microlens, which is determined by the spacing of the centroids of the microlenses. Thus, a coordinate system with a first coordinate axis and a second coordinate axis, preferably at right angles, is spanned by the microlens grid. The microlenses of the microlens grid now follow one another in the direction of the first coordinate axis and / or in the direction of the second coordinate axis, the centroids of the microlenses preferably lying on a line that is oriented parallel to one of these coordinate axes and preferably parallel to the first spatial direction. The dimensions of the respective microlens in the first spatial direction is the distance between the base points of the respective microlens, which is defined by the intersection of one in the direction of the first spatial direction oriented straight lines passing through the centroid of the respective microlens with the outer boundary line of the respective microlens.

It has been shown that with such a procedure the layer thickness of the base film or the multilayer body necessary for generating the first optically variable information can be significantly reduced. The focal length of the microlens on the one hand influences the layer thickness of the first layer necessary for the molding of the microlenses and also the spacing of the second layer from the surface of the first layer facing away from the second layer. If the focal length is increased, the layer thickness of the first layer required for the molding is reduced, but the distance between the base points of the microlenses and the second layer, which is preferably in the range of the focal length of the microlenses, increases accordingly. Although the light intensity of the first optically variable information item is somewhat reduced by the measures described above, the layer thickness of the multilayer body can be significantly reduced despite the effects described above.

It is also advantageous if the maximum structure height of the respective microlens is at least 35%, in particular at least 50% of the dimension of the respective microlens in the first spatial direction. The maximum structure height of the respective microlens is understood to mean the maximum elevation of the microlens above the base point plane of the microlens spanned by the base points of the microlens.

In particular, it is also possible that the microimages are each formed by one or more image areas that are surrounded by a background area. This enables particularly diverse design variations that represent a high recognition value for the viewer. Furthermore, it is also possible that the one or more image areas are opaque and the background area is transparent, or that the one or more image areas are transparent and the background area is opaque. It is preferably also provided that the one or more image areas on the one hand and the background area on the other hand have different reflection properties. It is also advantageous if the one or more image areas and the background area have different polarization properties.

It is also advantageous if the second layer has a metallic layer, a colored lacquer layer and / or a photoresist layer which is provided in the first area in the image areas and not provided in the background area, or vice versa. The photoresist layer here preferably consists of a positive or negative photoresist, which more preferably can also be colored with a dye or pigment.

It is preferably also provided that the one or more image areas and / or the background ground area are covered with an optically variable element, in particular the image areas on the one hand and the background area on the other hand are covered with different optically variable elements. The optically variable elements can be formed, for example, from optically active surface reliefs, in particular from diffraction structures, for example diffraction structures such as holograms or Kinegram®. It is also advantageous if the optically variable elements are formed from thin-film layer elements which have an optical layer thickness of 1/2 or 1/4, for 1 in the wavelength range of visible light, and show viewing angle-dependent color shift effects, or are formed from a liquid crystal layer which shows different polarization properties in different areas or also shows a viewing angle-dependent color shift effect. The second layer advantageously also has a replication lacquer layer with a surface relief molded into the surface of the replication lacquer layer, with - as explained above - that in the Image areas on the one hand and in the background areas on the other hand molded surface relief is different.

Furthermore, it is preferably provided that the color, the reflection properties and / or the absorption properties of the second layer are varied within the image areas.

It has also been found to be advantageous if the microlens grid is arranged rotated by 45 ° with respect to the longitudinal axis of the base film or the multilayer body. It has been shown that particularly interesting optical effects can be generated in this way, especially when using a one-dimensional microlens grid. If, for example, a one-dimensional microlens grid is used in which the focal point lines of the microlenses, which are preferably oriented parallel to one another, are arranged at a 45 ° angle to the longitudinal axis of the multilayer body or the base film, this turns around when the multilayer body or the base film is tilted the horizontal axis as well as a predetermined movement effect around the vertical axis, which can take place at any angle from 0 ° to 360 °. Furthermore, a movement can also take place along a non-linear path, for example along a curved curve. The longitudinal axis of the multilayer body or the base film is understood here to mean the coordinate axis oriented in the direction of the length of the multilayer body or the base film.

It is preferably also possible that the microlens grid and / or the microimage grid is a two-dimensional microlens grid or microimage grid and two or more microlenses or microimages in a first spatial direction and in a second spatial direction with a respective grid width between 5 μm and 150 μm on top of one another follow. The microlens grid or microimage grid spans a coordinate system with two coordinate axes, preferably at right angles to one another, with the microlenses or microimages both in a first spatial direction, in particular in the direction of one coordinate axis, and in a second spatial direction, especially in the direction of the other coordinate axis. The spacing between adjacent microimages or microlenses is here preferably determined by the spacing of the centroids of the microlenses or microimages and preferably corresponds to the respective grid width.

However, it is preferably also possible that the microlens grid and / or the microimage grid is a one-dimensional microlens grid or microimage grid and two or more microlenses or microimages follow one another in a first spatial direction with a respective grid width between 5 pm and 300 pm. The micro-image grid and / or the microlens grid can be a regular grid with constant grid widths, but also an irregular grid with varying grid widths. Furthermore, it is also possible that the coordinate systems spanned by the microlens grid and / or the micrographic grid are geometrically transformed and thus the coordinate axes do not have the shape of a straight line, but are, for example, serpentine or circular.

The raster widths of the micro-image raster and of the micro-lens raster for respectively adjacent micro-images and microlenses preferably differ from one another by less than 10%, in particular by less than 5% from one another. Advantageously, particularly complex microimages and complex movement effects can be achieved with identical raster widths for the microimage raster and the microlens raster. In such a configuration, a moiré magnification effect is produced when using identical micrographs, i.e. the first optically variable information visible at a certain viewing angle corresponds to an enlarged representation of the (identical)

Micro images. However, this measure has also proven to be advantageous when using different microimages, which lead to the generation of more complex movement and transformation effects when the multilayer body is tilted. It has also been proven that the micro-image grid and the microlens grid are arranged rotated by less than 5 ° with respect to one another, ie the axes of the coordinate axes assigned to one another of the coordinate system spanned by the micro-image grid and the microlens grid enclose such an angle. It can advantageously also be provided that the micro-image grid and the micro-lens grid are not arranged rotated relative to one another.

It has also proven to be advantageous if in the first area the raster width of the microlens grid and / or the microimage grid and / or the rotation of the microimage grid and the microlens grid relative to one another are continuously varied according to a parameter variation function in at least one spatial direction. In this way, the above-mentioned enlargement, reduction and transformation effects can be achieved when tilting.

It is also advantageous if the micro-image grid in the first area has at least two micro-images that differ from one another. It is particularly advantageous if the shape and / or color of the microimages in a first area changes continuously according to a transformation function and so when tilting, for example, movement effects combined with enlargement, reduction and transformation effects are brought about.

It is preferably also possible that in a first sub-area of the first area the grid width of the microlens grid and / or the grid width of the microimage grid and / or the rotation of the microimage grid and the microlens grid relative to one another differ from the grid width of the microlens grid, the grid width of the microimage grid or the Rotation of the micro-image grid and the microlens grid differs from one another in a second sub-area of the first area. This has the effect that the optically variable appearance in the first and the second partial area differs from one another and thus the protection against forgery is further improved. In particular, it is provided that the at least one transfer film has at least one transfer layer and at least one carrier layer, the at least one transfer layer being detachable from the at least one carrier layer.

It is preferably possible that the at least one transfer layer comprises at least one layer selected from: adhesive layer, colored layer, decorative layer, reflective layer, adhesion promoter layer, release layer, protective layer, metal layer, replication layer and / or combinations thereof.

It is preferably possible that in step c) the application of the at least one transfer layer is carried out by means of hot stamping or cold stamping.

In the case of hot stamping, an adhesive layer of the at least one transfer layer is preferably activated by the heat input from the embossing stamp and a certain section of the at least one removable transfer layer is applied to the base film by the shaping of the embossing stamp. A part of the transfer layer or the entire surface of the transfer layer can be understood as a cutout.

In the case of cold embossing, an adhesive layer is first applied at least partially to the surface of the base film and / or to the free surface of the transfer layer of the transfer film, in particular by means of an inkjet printing process. Subsequently, the transfer film is guided against the surface of the base film, the adhesive layer, in particular by means of UV radiation and / or electron beams, and the transfer film is peeled off again before or after the irradiation, so that a specific section of the transfer layer is created by the shape of the at least partially applied adhesive layer the base film is applied.

It has been found to be advantageous if an adhesive is used in step c) selected from: single-layer adhesive, multi-layer adhesive, adhesive on water-based, solvent-based adhesives, radiation-curing adhesives, thermally activated adhesives or combinations thereof.

It is also possible for the adhesive layer in step c) to have a layer thickness in the range from 0.3 gm to 25 gm, preferably from 1 gm to 20 gm. Surprisingly, it has been shown that the adhesive strength is highest when the adhesive layer has a thickness which corresponds approximately to the height of the microlenses. With an adhesive thickness that is less than the height of the microlenses, so-called tip contacts occur on the joining surfaces, which reduce the adhesive strength.

In particular, it is provided that in step c) the adhesive layer is applied by means of a printing process and / or by means of casting and / or by means of a doctor blade. It is also advantageous if the adhesive layer is applied at least partially, preferably over the entire area.

In particular, it is provided that the adhesive layer has at least one binder selected from: polyacrylates, polyurethanes, epoxies, polyesters, polyvinyl chlorides, rubber polymers, ethylene-acrylic acid copolymers, ethylene-vinyl acetates, polyvinyl acetates, styrene block copolymers, phenol-formaldehyde resin adhesives, Melamines, alkenes, allyl ethers, vinyl acetate, alkyl vinyl ethers, conjugated dienes, styrene, acrylates and / or combinations thereof.

It is further preferably provided that the adhesive layer has at least one solvent selected from: water, aliphatic (gasoline) hydrocarbons, cycloaliphatic hydrocarbons, terpene hydrocarbons, aromatic (benzene) hydrocarbons, chlorinated hydrocarbons, esters, ketones, alcohols, glycols, glycol ethers, Glycol ether acetates and / or combinations thereof.

It is also possible that the adhesive has at least one additive selected from: hardeners, crosslinkers, photoinitiators, fillers, stabilizers, Inhibitors, additives such as leveling additives, defoamers, deaerators, dispersing additives, wetting agents, lubricants, matting agents, rheological additives, pigments, dyes, waxes and / or combinations thereof. A suitable choice of fillers or waxes can, for example, reduce the tack of the adhesive at room temperature.

In particular, a thermally activatable adhesive and / or an adhesive which has thermoplastic and / or UV-based raw materials has a solids content in the range from 10% to 40%, preferably from 15% to 35%. This means that the application on the painting machine can be of good quality. It is preferably also provided that the adhesive has a non-sticky surface after drying, in particular at room temperature. It is also advantageous if the choice of raw materials for the adhesive is chosen such that the processing temperature during the manufacture of the multilayer body is always above the glass transition temperature and below the melting point of the adhesive.

For example, an adhesive consisting of one layer can comprise a mixture of two acrylates, the application weight of the one layer being in a range from 1 g / m ² to 16 g / m ² . A mixture of polyacrylate dispersion, for example ethylene-acrylic acid copolymer dispersion and acrylate copolymer dispersion, and a mixture of polyacrylate dispersion, for example ethylene-acrylic acid dispersion and aliphatic polyurethane dispersion, have proven particularly advantageous. A single-layer adhesive has the particular advantage that the adhesive layer can be applied with a single printing unit. This is a particularly cost-effective process variant.

For example, an adhesive can also consist of two layers, the first layer being a mixture of polyacrylate dispersion, eg ethylene-acrylic acid copolymer dispersion and acrylate copolymer dispersion with an application weight in a range from 0.5 g / m ² to 8 g / m ² includes and the second Layer comprises a mixture of polyacrylate dispersion, for example ethylene-acrylic acid copolymer dispersion and aliphatic polyurethane dispersion with an application weight in a range from 0.5 g / m ² to 8 g / m ² , the second layer being arranged to the microlenses of the base film is.

It is also possible for the adhesive to have two layers and an SiOx vapor deposition, the SiOx vapor deposition being applied to the microlenses of the base film; and wherein the first layer comprises a mixture of acrylates and polyurethanes with an application weight in a range from 0.5 g / m ² to 8 g / m ² , selected from: polyacrylate dispersion, for example ethylene-acrylic acid copolymer dispersion, aliphatic polyurethane dispersion , aliphatic polyether polyurethane dispersion; and wherein the second layer comprises a UV-crosslinking polyurethane dispersion with an application weight in a range from 0.5 g / m ² to 8 g / m ^2.

It is also possible that the adhesive has four layers, the first layer having a mixture of polyvinyl chloride and its polymers, selected from: mixture of vinyl chloride and acetate terpolymer, vinyl chloride, vinyl acetate, vinyl alcohol terpolymer, epoxy-functional vinyl chloride-vinyl acetate terpolymer and / or combinations thereof; and wherein the second layer comprises a mixture of polyacrylate and polyurethane resins selected from: polyacrylate, polyester-polyurethane, aliphatic polyether-polyurethane dispersion, polyester resin; and wherein the third layer comprises a mixture of polyurethane and polyacrylate selected from: polyester-polyurethane, ethylene-methacrylic acid copolyester and / or combinations thereof; and wherein the fourth layer comprises a mixture selected from: polyester resin, ethylene vinyl acetate copolymer, chlorinated polyolefin, polyvinyl chloride (vinyl chloride, vinyl acetate, vinyl alcohol terpolymer), hydrocarbon resin and / or combinations thereof. It is preferably also provided that the mixtures of the second and third layers are or will be crosslinked. A multi-layer adhesive layer offers the particular advantage that, in addition to Tesa adhesion, a large number of chemical resistances can also be achieved. Chemical resistance is the resistance of the adhesive layer to the effects of chemicals. The composition of the adhesive layers is preferably selected so that they have sufficient resistance to predefined chemicals. Furthermore, it is advantageously provided that, in the case of multilayer adhesives, there is intermediate adhesion of the individual layers to one another. This is done through a suitable choice of adhesive components.

Furthermore, it is also possible that the following step is carried out before step c): d) Pretreatment of the surface of the microlenses with at least one method selected from: corona treatment, flame treatment, plasma treatment, vapor deposition with thin chromium or SiOx layers, application at least an adhesion promoter layer and / or combinations thereof.

The microlenses are usually molded in a replication layer, preferably in a UV replication layer. Such a replication layer is characterized by extreme hardness and poor adhesive properties. In order to improve the adhesion to adhesives and / or foils, it is preferable to use a pretreatment according to one of the above-mentioned processes. It is also particularly advantageous if the layers applied in step d) have a transparency of more than 90%, preferably more than 95%, particularly preferably more than 99%. Such transparency offers the advantage that the effect generated by the microlenses is influenced as little as possible.

It is also advantageous if the at least one adhesion promoter layer comprises at least one material selected from: polyester, epoxy, polyurethane, acrylate, copolymer resins and / or combinations thereof. It is also possible that the at least one adhesion promoter layer has a layer thickness in the range from 0.01 μm to 15 μm, preferably from 0.1 μm to 5 μm.

The adhesion of the at least one transfer layer on the at least one base film is determined by means of the following test at room temperature:

From a film pattern comprising at least one base film and at least one transfer layer of the transfer film applied to it, three film specimens are cut out in the longitudinal direction to the design. However, it can also be provided that the film pattern has at least one target substrate, at least one base film and at least one transfer layer. The dimensions of the film test specimen are 51 mm in length and 15 mm in width. The film test specimen is placed flat on a flat surface. A 10 cm long strip of Tesa film of the brand Tesa and of the type 4104 with a width of 15 mm is peeled off from a dispenser, with 1 cm being folded over to form a tab at one end of the strip, so that an adhesive length of 8 cm results. This Tesa strip with tab is placed along the center of the foil test piece on the transfer layer side and pressed with the thumb by wiping it 5 times on the transfer layer side of the foil test piece.

The following two variants are suitable for peeling off the tape:

In the first variant, the Tesa strip is tightened at an angle of about 45 ° and pulled upwards from the foil test specimen with a jerk, the foil test specimen being held down with two fingers.

In the second variant, the Tesa strip is tightened at an angle of 135 ° in a fluid movement forwards, ie in a horizontal direction to the side facing away from the flap, pulled off the foil test specimen, the foil test specimen being held down with two fingers. Both the embossing of the film test specimen and the strip of tape that has been pulled off are examined with regard to tears in the entire transfer layer and / or the detachment of individual layers of the transfer layer. It has preferably been found here that less than 50%, preferably less than 10%, of the entire transfer layer remains on the tape after a test. The assessment is preferably carried out by scanning the peeled off tape and / or purely visually by comparing it with the actual second optical information.

It is advantageously provided that the at least one transfer layer of the at least one transfer film with regard to the surface, in particular width or length, is approximately the same size or smaller or greater than the surface, in particular width or length, of the base film, in particular the first layer, preferably the Microlens elements, is.

In other words, the base film has two opposing edges at least in some areas and the transfer film is arranged at least in some areas between these opposing edges of the base film. The area of the transfer film between the opposite edges of the base film can be approximately the same size, smaller or greater than the distance between the opposite edges of the base film.

In the event that the surface, in particular width or length, of the transfer layer is smaller than the surface, in particular width or length, of the base film, it has surprisingly been shown that the embossed edges of the transfer layer are protected by the microlenses of the base film and thus attempts to remove the Transfer layer can be prevented better in comparison to a transfer layer applied to a smooth surface.

In the event that the surface, in particular width or length, of the transfer layer is approximately the same size as the surface, in particular width or length, of the base film, there is the advantage that the outer contour of the Microlenses of the base film act as a punched edge or counter-pressure element for the die. This enables the transfer layer to break cleanly at the edge of the base film and thus automatically a clean embossing of the transfer layer with the same size as the base film.

In the event that the surface, in particular width or length, of the transfer layer is larger than the surface, in particular width or length, of the base film, there is the advantage that the transfer layer overlaps the base film and thus provides additional protection. In particular, the edge of the microlenses is thus protected. This also prevents the base film from becoming detached from the target substrate and increases the security against forgery.

It is advantageously provided that the at least one transfer layer of the at least one transfer film is completely opaque or partially opaque or colored or translucent or at least partially transparent or semitransparent or has such a transparency so that after the transfer layer has been applied to and / or under the base film the first optically variable information is at least partially suppressed or deleted. In the case of an opaque transfer layer, at least one layer of the transfer layer is metallized. This can be a metallized reflective layer, for example. In the event that the at least one transfer layer is partially opaque, it is preferably provided that at least one layer of the transfer layer is at least partially metallized. A semitransparent transfer layer is preferably a thin-film layer system which comprises, for example, a partially transparent metal layer and / or a dielectric layer and / or an opaque metal layer. It is preferably also possible for the at least one transfer layer to be designed as a high-resolution, partially metallized structure with structure sizes of the metallized areas and / or the non-metallized areas of less than 50 μm, preferably less than 20 μm. In the case of a colored transfer layer, at least one layer of the transfer layer is colored. In the event that the transfer layer is designed to be transparent, it is, for example, an HRI layer (High Refractive Index) with a refractive index in the range from 1.55 to 2.8.

If the at least one transfer layer is designed in a translucent color, it is, for example, a partial color filter.

Furthermore, it is preferably provided that the at least one transfer layer provides second optical information, in particular optically variable information. In particular, it is provided that the second optical information item is different from the first optical information item. For example, the second optical information is an optical effect, selected individually or in combination from: virtually appearing effect image, colored effect image, achromatic effect image, movement effect, 3D effect, lens effect, micro-motif, nano-motif, depth effect, color change, contrast change, image change , variable shadows and / or similar effects.

It is preferably provided that the second optical information item extinguishes and / or suppresses and / or covers the first optical information item at least in the areas in which the transfer layer is applied on and / or under the base film. This enables a wide range of design variations that generate a special optical effect.

It is preferably also possible for the transfer layer to optically delete the microlenses molded in the first layer of the base film and / or the microimages molded in the second layer of the base film. The first layer of the base film is advantageously optically extinguished in that at least the adhesive layer of the transfer layer has the same or a similar refractive index as the first layer of the base film. In particular, the refractive index of the first layer and the refractive index of the adhesive layer of the transfer layer differ by a maximum of 0.4, in particular by a maximum of 0.2. The at least one transfer layer for erasing the first layer of the base film is preferably applied at least partially to the base film. This results in the advantage that, due to the same refractive index of the transfer layer and the first layer of the base film, the enlargement, reduction and / or transformation effect caused by the microlenses of the first layer of the base film is suppressed. In this case, only the microimages of the second layer of the base film are visible to the human observer.

However, it is also possible for the second layer of the base film to be extinguished by at least partially applying the at least one transfer layer below the base film. For this purpose, the transfer layer preferably has the same or a similar refractive index as the second layer of the base film. It is advantageously also provided that both the first layer and the second layer of the base film are extinguished by at least partially applying at least one transfer layer on and under the base film.

It is preferably also possible that the second optical information, in particular optically variable information, has at least one element selected from: a graphically designed outline, a figurative representation, an image, a single image, a pattern, an endless pattern, a motif, a Symbol, a logo, a portrait, a grid, an alphanumeric character, a text and / or combinations thereof.

It is advantageously provided that the at least one transfer layer has at least one surface relief, the surface relief having one or more relief structures selected from the group of diffractive grating, hologram, blaze grating, linear grating, cross grating, hexagonal grating, asymmetrical or symmetrical grating structure, retroreflective structure, microprism, diffraction structure Zero order, moth-eye structure or anisotropic or isotropic matt structure, Kinegram or a superposition of two or more of the aforementioned relief structures. It is preferably also provided that in step c) the application of the at least one transfer layer takes place by means of embossing, the embossing at a temperature of 80 ° C to 300 ° C, preferably 100 ° C to 240 ° C, particularly preferably 100 ° C to 190 ° C.

It has been found to be advantageous if, in step c), the embossing is carried out with an embossing pressure of 10 N / cm ² to 10,000 ^{N / cm 2} , preferably of 100 N / cm ² to 5000 N / cm ² .

In particular, it is also provided that in step c) the embossing takes place with an embossing time of 0.01 s to 2 s.

It is also possible that, in step c), the transfer layer is applied to the base film in precise register with a register precision in the longitudinal direction in the range from -1.0 mm to 1.0 mm, preferably from -0.5 mm to 0.5 mm, and / or a register accuracy in the transverse direction in the range from -0.5 mm to 0.5 mm, preferably from -0.3 mm to 0.3 mm, particularly preferably from -0.2 mm to 0.2 mm.

Register or register accuracy or register accuracy is to be understood as the positional accuracy of two or more elements and / or layers relative to one another. The register accuracy should move within a specified tolerance and be as low as possible. At the same time, the register accuracy of several elements and / or layers to one another is an important feature in order to increase process reliability. The positionally accurate positioning can take place in particular by means of sensory, preferably optically detectable, register marks or register marks. These registration marks or register marks can either represent special separate elements or areas or layers or can themselves be part of the elements or areas or layers to be positioned. It is preferably also provided that after step a) the following step is carried out: a1) applying the base film to a target substrate.

The target substrate is, for example, the paper sheet of a bank note, a plastic sheet of a data card, an identification document, a value document and / or any other security documents.

It is preferably also provided that the multilayer body has at least one target substrate, the at least one base film being arranged on the target substrate.

This has the advantage that the base film is already applied to the target substrate. The transfer layer can then be applied, for example, at a different location or at the customer's. This represents a particularly cost-effective manufacturing variant.

It can also be provided that the base film is designed as a laminating film, hot stamping film or cold stamping film and is applied to the target substrate using a method that is suitable for the respective type of film.

In particular, it is provided that in step a1) the application of the base film to the target substrate is in register with a register accuracy in the longitudinal direction in the range from -1.0 mm to 1.0 mm, preferably from -0.5 mm to 0.5 mm, and / or a register accuracy in the transverse direction in the range from -0.5 mm to 0.5 mm, preferably from -0.3 mm to 0.3 mm, particularly preferably from -0.2 mm to 0.2 mm.

Furthermore, it is also possible for the following step to be carried out after step c): c1) applying the multilayer body to a target substrate. Advantageously, it is provided that in step c1) the application of the multilayer body to the target substrate in register with a register accuracy in the longitudinal direction in the range from -1.0 mm to 1.0 mm, preferably from -0.5 mm to 0.5 mm, and / or a register accuracy in the transverse direction in the range from -0.5 mm to 0.5 mm, preferably from -0.3 mm to 0.3 mm, particularly preferably from -0.2 mm to 0.2 mm.

Advantageous exemplary embodiments of the invention are specified in the subclaims.

Further embodiments of the invention are shown in the figures and described below. Show:

1: a schematic representation of a method for producing a multilayer body

2a: a schematic representation of a method for producing a multilayer body

2b: a schematic representation of a method for producing a multilayer body

3: a schematic representation of a multilayer body

4a: a schematic representation of the application of a

Multi-layer body on a target substrate

4b: a schematic representation of the application of a

Multi-layer body on a target substrate

5: a schematic representation of a multilayer body 6: a schematic representation of a multilayer body

7: a schematic representation of a multilayer body

8: a variant embodiment of a multilayer body

9: a variant embodiment of a multilayer body

10: a variant embodiment of a multilayer body

11: a variant embodiment of a multilayer body

12: a variant embodiment of a multilayer body

13: a variant embodiment of a multilayer body

14: a variant embodiment of a multilayer body

15: a variant embodiment of a multilayer body

16: a variant embodiment of a multilayer body

In the following, the invention is explained by way of example on the basis of several exemplary embodiments with the aid of the accompanying drawings. The exemplary embodiments shown are therefore not to be understood as restrictive.

FIG. 1 shows a schematic representation of a method for securing a multilayer body 40, preferably a security element, particularly preferably a document of value, the following steps being carried out in particular in the following sequence: a) providing at least one base film 20 b) providing at least one transfer film c) At least partial application of at least one transfer layer 10 of the at least one transfer film on and / or under the at least base film 20.

It is preferably possible that in step c) the application of the at least one transfer layer 10 is carried out by means of hot stamping or cold stamping.

In particular, it is provided that in step c) the transfer layer 10 is applied to the base film 20 in precise register with a register precision in the longitudinal direction in the range from -1.0 mm to 1.0 mm, preferably from -0.5 mm to 0.5 mm, and / or a register accuracy in the transverse direction in the range from -0.5 mm to 0.5 mm, preferably from -0.3 mm to 0.3 mm, particularly preferably from -0.2 mm to 0.2 mm, he follows.

In particular, an adhesive is used in step c) selected from: single-layer adhesive, multilayer adhesive, aqueous-based adhesive, solvent-based adhesive, radiation-curing adhesive, thermally activated adhesive, or combinations thereof. In particular during hot stamping, the adhesive is part of the at least one transfer layer 10 as an adhesive layer, whereas during cold stamping the adhesive is preferably applied to the surface of the base film 20, preferably to the surface of the first layer 21 of the base film 20, by means of a printing process.

It is preferably provided that in step c) the adhesive has a layer thickness in the range from 0.3 μm to 25 μm, preferably from 1 μm to 20 μm. It has surprisingly been shown here that the layer thickness of the adhesive should approximately correspond to the structural height of the microlenses in order to ensure the highest possible adhesion to the transfer layer 10.

It is also possible that the adhesive has at least one binder selected from: polyacrylates, polyurethanes, epoxies, polyesters, polyvinyl chlorides, rubber polymers, ethylene-acrylic acid copolymers, ethylene-vinyl acetates, Polyvinyl acetates, styrene block copolymers, phenol-formaldehyde resin adhesives, melamines, alkenes, allyl ethers, vinyl acetate, alkyl vinyl ethers, conjugated dienes,

Styrene, acrylates and / or combinations thereof.

Furthermore, it is preferably possible that the adhesive has at least one solvent selected from: water, aliphatic (gasoline) hydrocarbons, cycloaliphatic hydrocarbons, terpene hydrocarbons, aromatic (benzene) hydrocarbons, chlorinated hydrocarbons, esters, ketones, alcohols, glycols, glycol ethers, Glycol ether acetates and / or combinations thereof.

It is advantageously provided that the adhesive has at least one additive selected from: hardeners, crosslinkers, photoinitiators, fillers, stabilizers, inhibitors, additives such as leveling additives, defoamers, deaerators, dispersing additives, wetting agents, lubricants, matting agents, rheology additives, pigments, dyes, Waxes and / or combinations thereof.

In particular, it is provided that in step c) the at least one transfer layer 10 is applied by means of embossing, embossing at a temperature of 80 ° C. to 300 ° C., preferably 100 ° C. to 240 ° C., particularly preferably 100 ° C to 190 ° C.

It is further provided that in step c) the embossing takes place with an embossing pressure of 10 N / cm ² to 10,000 N / cm ² , preferably of 100 N / cm ² to 5000 N / cm ² .

It is preferably also provided that in step c) the embossing takes place with an embossing time of 0.01 s to 2 s.

It is preferably possible for the at least one base film 20 to have a transparent first layer 21 in which a plurality of microlenses are molded in a first area, which are arranged according to a microlens grid, and has a second layer 22 arranged below the first layer 21 , which has a plurality of microimages which are arranged in accordance with a microimage grid and each in an at least regionally overlapping manner with one of the microlenses of the microlens grid for generating a first optically variable item of information.

Furthermore, it is particularly possible for the first layer 21 to be formed as a replication layer with a layer thickness in the range from 0.1 μm to 30 μm, preferably from 0.3 μm to 20 μm.

In particular, it is provided that the grid widths of the micro-image grid and the microlens grid are each less than 300 μm in at least one spatial direction.

It is also possible for the respective grid width of the microlens grid in a first spatial direction to be at least 50%, in particular more than 100% greater than the respective dimension of the respective microlens in the first spatial direction.

It is preferably also provided that the maximum structure height of the respective microlens is at least 35%, in particular at least 50% of the dimension of the respective microlens in the first spatial direction.

For example, it is also possible that the microimages are each formed by one or more image areas that are surrounded by a background area.

It is advantageously provided that the one or more image areas are opaque and the background area is transparent, or that the one or more image areas are transparent and the background area is opaque. It is furthermore also possible that the one or more image areas on the one hand and the background area on the other hand have different reflection properties.

It is also possible for the second layer 22 to have a metallic layer, a colored lacquer layer and / or a photoresist layer which is provided in the first area in the image areas and not provided in the background area, or vice versa.

It is preferably also possible that the one or more image areas and / or the background ground area are covered with an optically variable element, in particular the image areas on the one hand and the background area on the other hand are covered with different optically variable elements.

It is also preferably provided that the one or more image areas and the background area have different polarization properties.

It is advantageously possible for the color, the reflection properties and / or the absorption properties of the second layer 22 to be varied within the image areas.

Furthermore, it can also be provided that the second layer 22 has a replication lacquer layer with a surface relief molded into a surface of the replication lacquer layer.

It is preferably possible for the microlens grid to be arranged rotated by 45 ° with respect to the longitudinal axis of the base film 20 or of the multilayer body 40.

In particular, it is provided that the microlens grid is a one-dimensional microlens grid and the focal lines of the microlenses are arranged rotated by 45 ° with respect to the longitudinal axis of the base film 20. It is also possible that the microlens grid and / or the microimage grid is a two-dimensional microlens grid or microimage grid and two or more microlenses or microimages follow one another in a first spatial direction and in a second spatial direction with a respective grid width between 5 μm and 150 μm .

Furthermore, it is also possible that the microlens grid and / or the microimage grid is a one-dimensional microlens grid or microimage grid and two or more microlenses or microimages follow one another in a first spatial direction with a respective grid width between 5 μm and 300 μm.

It is preferably provided that the raster widths of the micro-image grid and micro-lens grid differ from one another by less than 10% in each case for adjacent micro-images and micro-lenses, in particular differ from one another by less than 5%.

For example, it is also provided that the micro-image grid and the micro-lens grid are arranged rotated by less than 5 ° with respect to one another.

It is also possible that in the first area the raster width of the microlens grid and / or the microimage grid and / or the rotation of the microimage grid and the microlens grid relative to one another are continuously varied according to a parameter variation function in at least one spatial direction.

It is advantageously provided that the micro-image grid in the first area has at least two micro-images that differ from one another.

It is preferably possible for the shape and / or the color of the microimages to be varied continuously in accordance with a transformation function in a second area. For example, it is provided that in a first sub-area of the first area the grid width of the microlens grid, the grid width of the microimage grid and / or the rotation of the microimage grid and the microlens grid relative to one another differ from the grid width of the microlens grid, the grid width of the microimage grid or the rotation of the microimage grid and of the microlens grid differ from one another in a second sub-area of the first area.

FIG. 2a also shows a schematic representation of a method for producing a multilayer body 40. The method essentially comprises the same steps as shown in FIG. 1, but with the difference that the following step is carried out before step c): d) Pretreatment the surface of the microlenses with at least one method selected from: corona treatment, flame treatment, plasma treatment, vapor deposition with thin chromium or SiOx layers, application of at least one adhesion promoter layer and / or combinations thereof.

The microlenses in particular are molded in the form of a UV-based replication layer. Such largely cured UV lacquers are usually characterized by poor adhesive properties. In order to improve these adhesive properties, it is therefore advantageous to pretreat the microlenses using one of the above-mentioned methods. It is thus achieved that the at least one transfer layer 10 to be applied can produce sufficient adhesion to the base film 20.

It is furthermore preferably provided that the at least one adhesion promoter layer has a layer thickness in the range from 0.01 μm to 15 μm, preferably from 0.1 μm to 5 μm. By using an adhesion promoter layer, the adhesion properties, in particular with respect to the adhesive layer or the at least one transfer layer, can be significantly improved. In particular when applying at least one adhesion promoter layer, it is preferably provided that the at least one adhesion promoter layer comprises at least one material selected from: polyester, epoxy, polyurethane, acrylate,

Copolymer resins and / or combinations thereof.

FIG. 2b also shows a schematic representation of a method for producing a multilayer body 40. The method shown in FIG. 2b comprises essentially the same steps as the method in FIG. 2a, but with the difference that after step a) the following further steps The following step is carried out: a1) applying the base film 20 to a target substrate 30.

This has the advantage that the transfer layer 10 can be applied in a decentralized manner; for example, it is thus possible for the customer to apply individually designed transfer layers 10 to the multilayer body 40. This also creates a great variety of designs.

It is preferably provided that the target substrate 30 comprises a sheet of paper from a banknote, a sheet of plastic from a data card, a document of value, an identification document or the like.

In particular, it is provided that in step a1) the application of the base film 20 to the target substrate 30 is in register with a register accuracy in the longitudinal direction in the range from -1.0 mm to 1.0 mm, preferably from -0.5 mm to 0.5 mm, and / or a register accuracy in the transverse direction in the range from -0.5 mm to 0.5 mm, preferably from -0.3 mm to 0.3 mm, particularly preferably from -0.2 mm to 0.2 mm, he follows.

Alternatively, however, provision is also made for the following step to be carried out after step c): c1) applying the multilayer body 40 to a target substrate 30. It is preferably also possible that, in step c1), the application of the multilayer body 40 to the target substrate 30 in precise register with a register precision in the longitudinal direction in the range from -1.0 mm to 1.0 mm, preferably from -0.5 mm to 0, 5 mm, and / or a register accuracy in the transverse direction in the range from -0.5 mm to 0.5 mm, preferably from -0.3 mm to 0.3 mm, particularly preferably from -0.2 mm to 0.2 mm , he follows.

FIG. 3 shows a multilayer body 40 which has a base film 20 and a transfer layer 10 applied to the base film 20. In this embodiment, the transfer layer 10 is applied over the entire area to the base film 20. However, it is also possible for the transfer layer 10 to be applied to the base film 20 only partially and / or in areas and / or in an overlapping manner.

It is further preferably provided that the multilayer body 40 has at least one base film 20 and at least one transfer layer 10 of a transfer film applied on and / or under the base film 20.

The at least one transfer layer 10 preferably has at least one layer selected from: adhesive layer, colored layer, decorative layer, reflective layer, adhesive layer, release layer, protective layer, metal layer, replication layer and / or combinations thereof.

It is preferably also provided that the at least one transfer layer 10 of the at least one transfer film is completely opaque or partially opaque or colored or translucent or at least partially transparent or semitransparent or has such a transparency so that after application of the transfer layer 10 on and / or under the base film 20, the first optically variable information is at least partially suppressed or deleted.

Furthermore, it is particularly possible for the at least one transfer layer 10 to provide second optical information, in particular optically variable information. A second optical piece of information makes the Multi-layer body 40 increased further. It is preferably provided that the second optical information at least partially suppresses and / or extinguishes and / or covers the first optical information, so that the first optical information is visible to the human observer in the first partial areas and the second optical information is visible in the second partial areas.

FIG. 4 a shows a multi-layer body 40, having a base film 20 and a transfer layer 10 applied over the full area underneath, the multi-layer body 40 being applied to a target substrate 30. The base film 20 comprises a first layer 21, in which the microlenses are shaped, and a second layer 22, which provides the microimages. In this embodiment, it is provided in particular that the first optical information generated by the base film 20 is optically suppressed or optically deleted by the transfer layer 10 applied under the base film 20. This is achieved in that the adhesive layer of the transfer layer 10 has the same and / or a similar refractive index as the base film 20, in particular the first layer 21 and / or the second layer 22. An identical or similar refractive index, in particular a refractive index which differs by at most 0.4, preferably a refractive index that differs by at most 0.2, is preferably achieved using the same or similar materials or classes of substances. For example, many polymeric binders can also be used. Such binders have a similar refractive index which is approximately in a range from 1.3 to 1.7, preferably approximately 1.5. For example, the first optical information can be deleted if the base film 20, in particular if the first layer 21 and / or the second layer 22, has the same material as the transfer layer 10 and / or if the first layer 21 and / or the second layer 22, predominantly polymers comprise similar or identical to the adhesive layer of the transfer sheet 10.

FIG. 4b shows a further embodiment variant for applying a multi-layer body 40 to a target substrate 30. In this exemplary embodiment, the multi-layer body 40 has a base film 20, comprising a first layer 21 in which microlenses are molded, and one below in some areas the second layer 22, which is arranged on the first layer 21 and provides the microimages. The multilayer body 40 also has two transfer layers 10, the first transfer layer 10 being arranged above the first layer 21 in the area in which the second layer 22 is not present, and the second transfer layer 10 in the area in which the second layer 22 is not present, is arranged below the first layer 21. The adhesive layer of the first transfer layer 10 preferably has the same or a similar refractive index, in particular a refractive index that differs by at most 0.2 from that of the first layer 21 of the base film 20. This enables at least partial erasure of the microlenses molded in the first layer 21, ie the enlargement, reduction and / or transformation effect generated by the microlenses is suppressed. The second transfer layer 10 arranged below the microlenses can have a single image or an endless pattern which is visible to the human observer due to the extinction of the magnification effect of the microlenses in the area in which the microimages 22 are not present. Thus, the human observer perceives two pieces of optical information arranged next to one another. The first optical information is provided by the microimages and the second optical information is provided by the second transfer layer 10.

FIG. 5 shows a multilayer body 40, this comprising a transfer layer 10, a base film 20 and a target substrate 30. In particular, it is provided that the multilayer body 40 has at least one base film 20 and at least one transfer layer 10 of a transfer film applied on and / or under the base film 20.

It is further particularly provided that the multilayer body 40 has at least one target substrate 30 on which the base film 20 is applied.

In particular, it is provided that the at least one transfer layer 10 of the at least one transfer film with regard to the surface, in particular the width or the length, approximately the same size or smaller or larger than the surface, in particular width or length, of the base film 20, in particular the first layer 21, preferably the microlens elements. In the embodiment variant shown in FIG. 5, the width of the applied transfer film 10 is smaller than the width of the base film 20. This has the advantage that the microlens elements molded in the base film 20 protect or conceal the embossed edge of the transfer layer 10. As a result, attempts to detach the transfer layer 10 are better prevented than, for example, on a smooth surface.

6 shows the same embodiment of the multilayer body 40 as in FIG. 5, but with the difference that the width of the transfer layer 10 is approximately the same as the width of the base film 20. It can also be provided that the surface, in particular the width or length of the transfer layer 10 is approximately the same size as the surface, in particular width or length, of the base film 20. The microlens elements of the base film 20 are usually shaped in a replication layer. Such a replication layer is usually very hard and resistant. On the basis of these properties, the outer contour of the microlens elements can serve as an embossing aid when the transfer layer 10 is embossed. The hard outer contour of the microlens elements ensures that the transfer layer 10 breaks precisely at this contour. As a result, an extremely clean expression of the transfer layer 10 can be produced and, in addition, the contour of the microlens elements serves as a counterpart to the embossing die. The result is a very good embossing quality.

In Figure 7 the same embodiment of the multilayer body 40 is shown as in Figures 5 and 6, but with the difference that the width of the transfer layer 10 is greater than the width of the base film 20, ie the transfer layer 10 overlaps and protects the base film 20, in particular the microlens elements. It is preferably also provided that the surface, in particular the width or length, of the transfer layer 10 is greater than the surface, in particular width or length, of the base film 20. In addition, this increases the security against counterfeiting elevated. Another advantage is that this design provides additional protection against detachment.

FIG. 8 shows a further embodiment variant of a multilayer body 40, in particular a security document. The base film 20 and the transfer layer 10 are only applied in regions to a target substrate 30, the base film 20 being applied over the entire width of the target substrate 30. The transfer layer 10, on the other hand, is only applied in regions to the base film 20 and covers the first optically variable information of the base film 20 in this region. In this embodiment, the first optical information generated by the base film 20 has an endless pattern, preferably virtual appearing effect picture. The second optical information that is generated by the transfer sheet 10 also has an endless pattern which is different from the first optical information. The first optical information and the second optical information can preferably be perceived by the human observer as information arranged next to one another.

It is preferably also provided that the first optically variable information has at least one element selected from: a graphically designed outline, a figurative representation, an image, a single image, a pattern, an endless pattern, a motif, a symbol, a logo, a portrait, a grid, an alphanumeric character, a text and / or combinations thereof.

It is also possible that the second optical information, in particular optically variable information, preferably has at least one element as a virtually appearing effect image, selected from: a graphically designed outline, a figurative representation, an image, an individual image, a pattern, an endless pattern, a motif, a symbol, a logo, a portrait, a grid, an alphanumeric character, a text and / or combinations thereof. With such a configuration, diverse and individualized optical design elements can be realized, which at the same time increases the security against forgery. Furthermore, it is preferably provided that the at least one transfer layer 10 has at least one surface relief, the surface relief having one or more relief structures selected from the group of diffractive grating, hologram, blazed grating, linear grating, cross grating, hexagonal grating, asymmetrical or symmetrical grating structure, retroreflective structure, microprism , Zero order diffraction structure, moth-eye structure or anisotropic or isotropic matt structure, kinegram or a superposition of two or more of the aforementioned relief structures.

FIG. 9 shows a further embodiment variant of a multilayer body 40, the structure being similar to that in FIG. However, with the difference that in this variant the transfer layer 10 has a single image. It is possible for this individual image to be arranged with accurate register relative to the target substrate 30. This increases the security against counterfeiting and ensures high quality. The base film 20, on the other hand, has an endless pattern, preferably as an effect image that appears virtually. This can also be arranged in precise register relative to the target substrate 30.

FIG. 10 shows a further embodiment of a multilayer body 40, the structure being similar to that in FIG. 9, but with the difference that this time the transfer layer 10 has an endless pattern and the base film 20 has an individual image, preferably as a virtually appearing effect image, in particular in register relative to target substrate 30.

FIG. 11 shows a further embodiment variant of a multilayer body 40, the structure being similar to that in FIG. 10, but with the difference that both the transfer layer 10 and the base film 20 have a single image, preferably as a virtually appearing effect image. Both individual images can in particular be positioned with accurate register relative to the target substrate 30. In FIGS. 12 to 16, further advantageous configurations of a multilayer body 40 are shown, only a portion of the image of the multilayer body 40 being shown here.

FIG. 12 shows a further embodiment of a multilayer body 40 comprising a target substrate 30, a base film 20 and a transfer layer 10, the transfer layer 10 comprising an individual image in the form of a hexagonal frame as second optical information and the base film 20 an individual image in the form of the number “50 “As the first optical information. The transfer layer 10 is preferably arranged in register with the base film 20, so that the two individual images are also arranged in register with one another.

In Figure 13, a further embodiment of a multilayer body 40 is shown, comprising a target substrate 30, a base film 20 and a transfer layer 10, the transfer layer 10 having a second optical information as a single image in the form of a euro symbol and the base film 20 a first optical Has information as two individual images in the form of the number "50". The transfer layer 10 is preferably arranged in register with the base film 20, so that the two individual images are also arranged in register with one another.

FIG. 14 shows a further embodiment variant of a multilayer body, this comprising a target substrate 30, a base film 20 and a transfer layer 10. The base film 20 shows an individual image in the form of the number “50” as the first optical information item. The transfer layer 10 shows, as second optical information, an individual image in the form of a euro symbol, the transfer layer being designed to be semitransparent or translucent. The transfer layer 10 is preferably arranged in register with the base film 20, so that the two individual images are also arranged in register with one another. The second optical information is arranged above the first optical information so that both optical information can be recognized by the human observer. The semitransparent or translucent colored design of the transfer layer creates a color filter-like effect, which is the case with multi-color printing, for example makes many different shades appear translucent. Such a configuration of the multilayer body is particularly secure against counterfeiting.

FIG. 15 shows a further embodiment variant of a multilayer body 40, the multilayer body 40 having a target substrate 30, a base film 20 and a transfer layer 10. In this embodiment variant, the first optical information of the base film 20 is shown as a single image in the form of the number “50”. The second optical information, produced by the transfer layer 10, is in the form of stars arranged in a pattern or grid. The second optical information is superimposed on the first optical information, which produces a particularly impressive effect for the human observer. The transfer layer 10 is preferably arranged in register with the base film 20, so that the two individual images are also arranged in register with one another.

FIG. 16 shows an alternative embodiment variant of a multilayer body 40, this comprising a target substrate 30, a base film 20 and a transfer layer 10. In this alternative embodiment, the first optical information produced by the base film 20 represents a rectangle with an arrow attached to one side. The second optical information provided by the transfer layer 10 also represents a rectangle, this being a negative contour of the arrow the first optical information. The two optical information items are therefore linked to one another or arranged next to one another and together form an overall picture. For example, it can also be provided that the base film 20 is applied to the target substrate 30 in the size of the overall image and the transfer layer 10 is applied to the base film 20 only in the upper region of the overall image. The transfer layer 10 then suppresses the first optical information in the upper area, but allows this in the lower area of the overall image. The second optical information is then present for the human observer in the upper area of the overall image. The transfer layer 10 is preferably in register with the Base film 20 arranged so that both individual images are arranged in register with one another.

5

Reference list:

10 transfer layer

20 base film

21 first layer (microlens elements) 22 second layer (micro images)

30 target substrate

40 multilayer body

Claims

Expectations:

1. A method for producing a multi-layer body (40), preferably a security element, particularly preferably a document of value, the following steps being carried out in particular in the following sequence: a) providing at least one base film (20) b) providing at least one transfer film c) at least partially Applying at least one transfer layer (10) of the transfer film on and / or under the base film (20).

2. The method according to the preceding claim, characterized in that the at least one base film (20) has a transparent first layer (21) in which a plurality of microlenses are molded in a first area, which are arranged according to a microlens grid, and a has a second layer (22) arranged below the first layer (21), which has a plurality of microimages which are arranged according to a microimage grid and each in an at least regional overlap with one of the microlenses of the microlens grid to generate a first optically variable item of information.

3. The method according to claim 2, characterized in that the first optically variable information has at least one element selected from: a graphically designed outline, a figurative representation, an image, a single image, a pattern, an endless pattern, a motif, a symbol , a logo, a portrait, a grid, an alphanumeric character, a text and / or combinations thereof.

4. The method according to any one of claims 2 or 3, characterized in that the first layer (21) is formed as a replication layer with a layer thickness in the range from 0.1 μm to 30 μm, preferably from 0.3 μm to 20 μm.

5. The method according to any one of claims 2 to 4, characterized in that the grid widths of the micro-image grid and the microlens grid are each less than 300 pm in at least one spatial direction.

6. The method according to claim 5, characterized in that the respective grid width of the microlens grid in a first spatial direction is at least 50%, in particular more than 100% greater than the respective dimension of the respective microlens in the first spatial direction.

7. The method according to any one of claims 2 to 6, characterized in that the maximum structure height of the respective microlens is at least 35%, in particular at least 50% of the dimension of the respective microlens in the first spatial direction.

8. The method according to any one of claims 2 to 7, characterized in that the microimages are each formed by one or more image areas which are surrounded by a background area.

9. The method according to claim 8, characterized in that the one or more image areas are opaque and the background area is transparent, or that the one or more image areas are transparent and the background area is opaque.

10. The method according to any one of claims 8 or 9, characterized in that the one or more image areas on the one hand and the background area on the other hand have different reflection properties.

11. The method according to any one of claims 8 to 10, characterized in that the one or more image areas and / or the background ground area are covered with an optically variable element, in particular the image areas on the one hand and the background area on the other hand are covered with different optically variable elements.

12. The method according to any one of claims 8 to 11, characterized in that the second layer (22) has a metallic layer, a colored lacquer layer and / or a photoresist layer, which is provided in the first area in the image areas and not provided in the background area is, or vice versa.

13. The method according to any one of claims 8 to 12, characterized in that the one or more image areas and the background area have different polarization properties.

14. The method according to any one of claims 8 to 13, characterized in, that within the image areas the color, the reflection properties and / or the absorption properties of the second layer (22) are varied.

15. The method according to any one of claims 2 to 14, characterized in that the second layer (22) has a replication lacquer layer with a surface relief molded into a surface of the replication lacquer layer.

16. The method according to any one of claims 2 to 15, characterized in that the microlens grid is arranged rotated by 45 ° with respect to the longitudinal axis of the base film (20).

17. The method according to any one of claims 2 to 16, characterized in that the microlens grid is a one-dimensional microlens grid and the focal lines of the microlenses are arranged rotated by 45 ° with respect to the longitudinal axis of the base film (20).

18. The method according to any one of claims 2 to 17, characterized in that the microimages are each applied to a curved surface.

19. The method according to any one of claims 2 to 16, characterized in that the microlens grid and / or the microimage grid is a two-dimensional microlens grid or microimage grid and two or more microlenses or microimages in a first spatial direction and in a second spatial direction with a respective Successive grid widths between 5 pm and 150 pm.

20. The method according to any one of claims 2 to 19, characterized in that the micro lens grid and / or the micro image grid is a one-dimensional microlens grid or micro image grid and two or more microlenses or micro images follow one another in a first spatial direction with a respective grid width between 5 gm and 300 gm.

21. The method according to any one of claims 2 to 20, characterized in that the raster widths of the micro-image grid and micro-lens grid differ from each other by less than 10%, in particular between 0.5% and 5%, for adjacent micro-images and microlenses.

22. The method according to any one of claims 2 to 21, characterized in that the micro-image grid and the microlens grid are arranged rotated relative to one another between 0.5 ° and 50 °.

23. The method according to any one of claims 2 to 22, characterized in that in the first area the grid width of the microlens grid and / or the microimage grid and / or the rotation of the microimage grid and the microlens grid are varied continuously according to a parameter variation function in at least one spatial direction.

24. The method according to any one of claims 2 to 23, characterized in that the micro-image grid in the first area has at least two micro-images which differ from one another.

25. The method according to any one of claims 2 to 24, characterized in that that in a second area the shape and / or the color of the microimages is varied continuously according to a transformation function.

26. The method according to any one of claims 2 to 25, characterized in that in a first sub-area of the first area the grid width of the microlens grid, the grid width of the microimage grid and / or the rotation of the microimage grid and the microlens grid to each other differ from the grid width of the microlens grid, the The grid width of the micro-image grid or the rotation of the micro-image grid and the microlens grid differs from one another in a second sub-area of the first area.

27. The method according to any one of the preceding claims, characterized in that the at least one transfer film has at least one transfer layer (10) and at least one carrier layer, the at least one transfer layer (10) being removable from the at least one carrier layer.

28. The method according to any one of the preceding claims, characterized in that the at least one transfer layer (10) comprises at least one layer selected from: adhesive layer, color layer, decorative layer, reflective layer, flaft mediating layer, release layer, protective layer, metal layer, replication layer and / or combinations thereof .

29. The method according to any one of the preceding claims, characterized in that the at least one transfer layer (10) of the at least one transfer film is completely opaque or partially opaque or colored or translucent colored or at least partially transparent or semitransparent or has such a transparency so that after Applying the Transfer layer (10) on and / or under the base film (20), the first optically variable information is at least partially suppressed or deleted.

30. The method according to any one of claims 2 to 29, characterized in that the at least one transfer layer (10) provides second optical information, in particular optically variable information.

31. The method according to claim 30, characterized in that the second optical information extinguishes and / or suppresses the first optical information at least in the areas in which the transfer layer (10) is applied on and / or under the base film (20) / or covered.

32. The method according to claim 30 or 31, characterized in that the second optical information, in particular optically variable information, has at least one element selected from: a graphically designed outline, a figurative representation, an image, an individual image, a pattern , an endless pattern, a motif, a symbol, a logo, a portrait, a grid, an alphanumeric character, a text and / or combinations thereof.

33. The method according to any one of the preceding claims, characterized in that the at least one transfer layer (10) has at least one surface relief, the surface relief having one or more relief structures selected from the group of diffractive grating, hologram, blaze grating, linear grating, cross grating, hexagonal grating, asymmetrical or symmetrical grating structure, retroreflective structure, microprism, diffraction structure Zero order, moth-eye structure or anisotropic or isotropic matt structure, Kinegram or a superposition of two or more of the aforementioned relief structures.

34. The method according to any one of the preceding claims, characterized in that in step c) the application of the at least one transfer layer (10) is carried out by means of hot stamping or cold stamping.

35. The method according to any one of the preceding claims, characterized in that an adhesive is used in step c) selected from: single-layer adhesive, multilayer adhesive, aqueous-based adhesive, solvent-based adhesive, radiation-curing adhesive, thermally activated adhesive or combinations from it.

36. The method according to claim 35, characterized in that in step c) the adhesive has a layer thickness in the range from 0.3 μm to 25 μm, preferably from 1.0 μm to 20 μm.

37. The method according to any one of claims 35 or 36, characterized in that the adhesive has at least one binder selected from: polyacrylates, polyurethanes, epoxies, polyesters, polyvinyl chlorides, rubber polymers, ethylene-acrylic acid copolymers, ethylene-vinyl acetates, polyvinyl acetates, styrene -Block copolymers, phenol-formaldehyde resin adhesives, melamines, alkenes, allyl ethers, vinyl acetate, alkyl vinyl ethers, conjugated dienes, styrene, acrylates and / or combinations thereof.

38. The method according to any one of claims 35 to 37, characterized in that that the adhesive has at least one solvent selected from: water, aliphatic (gasoline) hydrocarbons, cycloaliphatic hydrocarbons, terpene hydrocarbons, aromatic (benzene) hydrocarbons, chlorinated hydrocarbons, esters, ketones, alcohols, glycols, glycol ethers, glycol ether acetates and / or combinations thereof .

39. The method according to any one of claims 35 to 38, characterized in that the adhesive has at least one additive selected from: hardeners, crosslinkers, photoinitiators, fillers, stabilizers, inhibitors, additives such as leveling additives, defoamers, deaerators, dispersing additives, wetting agents, Lubricants, matting agents, rheological additives, pigments, dyes, waxes and / or combinations thereof.

40. The method according to any one of claims 2 to 39, characterized in that the following step is carried out before step c): d) pretreatment of the surface of the microlenses with at least one method selected from: corona treatment, flame treatment, plasma treatment, vapor deposition with thin chromium - Or SiOx layers, application of at least one adhesion promoter layer and / or combinations thereof.

41.A method according to claim 40, characterized in that the at least one adhesion promoter layer comprises at least one material selected from: polyester, epoxy, polyurethane, acrylate, copolymer resins and / or combinations thereof.

42. The method according to any one of claims 40 or 41, characterized in that that the at least one adhesion promoter layer has a layer thickness in the range from 0.01 μm to 15 μm, preferably from 0.1 μm to 5 μm.

43. The method according to any one of the preceding claims, characterized in that in step c) the at least one transfer layer (10) is applied by means of embossing, embossing at a temperature of 80 ° C to 300 ° C, preferably 100 ° C to 240 ° C, particularly preferably from 100 ° C to 190 ° C.

44. The method according to claim 43, characterized in that in step c) the embossing takes place with an embossing pressure of 10 N / cm ² to 10,000 N / cm ² , preferably of 100 N / cm ² to 5000 N / cm ² .

45. The method according to any one of claims 43 or 44, characterized in that in step c) the embossing takes place with an embossing time of 0.01 s to 2 s.

46. The method according to any one of the preceding claims, characterized in that in step c) the transfer layer (10) is applied to the base film (20) in register with a register accuracy in the longitudinal direction in the range from -1.0 mm to 1.0 mm, preferably from -0.5 mm to 0.5 mm, and / or a register accuracy in the transverse direction in the range from -0.5 mm to 0.5 mm, preferably from -0.3 mm to 0.3 mm, particularly preferably from -0.2 mm to 0.2 mm.

47. The method according to any one of the preceding claims, characterized in that the at least one transfer layer (10) of the at least one transfer film is approximately the same size with regard to the surface, in particular width or length or is smaller or larger than the surface, in particular width or length, of the base film (20), in particular the first layer (21) of the base film (20), preferably the microlens elements.

48. The method according to any one of the preceding claims, characterized in that after step a) the following step is carried out: a1) applying the base film (20) to a target substrate (30)

49. The method according to claim 48, characterized in that in step a1) the application of the base film (20) to the target substrate (30) in register with a register accuracy in the longitudinal direction in the range of -1.0 mm to 1.0 mm, preferably of -0.5 mm to 0.5 mm, and / or a register accuracy in the transverse direction in the range from -0.5 mm to 0.5 mm, preferably from -0.3 mm to 0.3 mm, particularly preferably from -0 , 2 mm to 0.2 mm.

50. The method according to the preceding claim, characterized in that after step c) the following step is carried out: c1) applying the multilayer body (40) to a target substrate (30).

51. Multi-layer body (40), in particular produced with a method according to claims 1 to 50, characterized in that the multi-layer body (40) has at least one base film (20) and at least one transfer layer ( 10) a transfer film.

52. Multi-layer body (40) according to claim 51, characterized in that that the multilayer body (40) has at least one target substrate (30), the at least one base film (20) being arranged on the target substrate (30).

53. Multi-layer body (40) according to one of claims 51 or 52, characterized in that the at least one base film (20) has a transparent first layer (21) in which a plurality of microlenses are molded in a first area, which according to a Microlens grid are arranged, and a second layer (22) arranged below the first layer (21), which has a plurality of microimages, which according to a microimage grid and in each case in an at least regional overlap with one of the microlenses of the microlens grid to generate a first optical variable information are arranged.

54. Multi-layer body (40) according to claim 53, characterized in that the at least one transfer layer (10) provides second optical information, in particular second optically variable information.

55. Multi-layer body (40) according to claim 54, characterized in that the second optical information extinguishes and / or eliminates the first optical information at least in the areas in which the transfer layer (10) is applied on and / or under the base film (20) or suppressed and / or covered.