EP2939845A2 - See-through safety element with microstructures - Google Patents

Abstract

The invention relates to a see-through security element (12) for security papers, value documents and the like having at least one microstructure with a viewing appearance-dependent visual appearance (26, 28). According to the invention, the at least one microstructure is formed from an array of a plurality of structural elements (24) having a characteristic pitch of 1 μm or more, and the see-through security element (12) has a total thickness of 50 μm or less.

Description

The invention relates to a see-through security element for security papers, documents of value and the like having at least one microstructure with a viewing angle-dependent visual appearance.

Data carriers, such as valuables or identity documents, or other valuables, such as branded articles, are often provided with security elements for the purpose of security, which permit verification of the authenticity of the data carriers and at the same time serve as protection against unauthorized reproduction. The security elements may be in the form of, for example, a security thread embedded in a banknote, a tearing thread for product packaging, an applied security strip, a cover sheet for a banknote having a through opening or a self-supporting transfer element, such as a patch or label after its manufacture is applied to a document of value.

Security elements with viewing-angle-dependent effects play a special role in the authentication of authenticity since they can not be reproduced even with the most modern copiers. The security elements are thereby equipped with optically variable elements that give the viewer a different image impression under different viewing angles and, for example, show a different color or brightness impression and / or another graphic motif depending on the viewing angle.

Proceeding from this, the present invention seeks to provide a see-through security element of the type mentioned, which avoids the disadvantages of the prior art. In particular, the see-through security element as a security feature have an easily recognizable optical information that offers a high protection against counterfeiting and does not require special lighting conditions for the authenticity check.

This object is achieved by the see-through security element having the features of the main claim. A security paper, a data carrier and a corresponding manufacturing method are specified in the independent claims. Further developments of the invention are the subject of the dependent claims.

According to the invention, in a generic see-through security element, the at least one microstructure is formed from an arrangement of a multiplicity of structural elements with a characteristic structure spacing of 1 μm or more. In addition, the see-through security element according to the invention has a total thickness of 50 microns or less.

The inventive arrangement of a plurality of structural elements may be a regular, irregular or regionally regular arrangement. The invention thus encompasses any arrangement of a multiplicity of structural elements which has a structure spacing of 1 μm or more.

The see-through security element preferably has a transparent or translucent substrate and a marking layer applied to the substrate, which contains the at least one microstructure.

In principle, any transparent or translucent substrate can be used for the see-through security element. In this case, the light transmittance must be at least so large that in the transmitted light the viewing angle-dependent appearance can be perceived by the viewer. The use of an additional means of illumination to improve the visibility of the appearance by the viewer is conceivable, although the thickness of the material is chosen according to the invention so that the optically variable appearance of the see-through security element is possible without tools.

Accordingly, paper, in particular cotton vellum paper, is fundamentally conceivable as a substrate. Of course, it is also possible to use paper which contains a proportion of polymeric material in the range of 0 <x <100% by weight.

However, it is particularly preferred if the substrate is a plastic, in particular a plastic film, for. As a film of polyethylene (PE), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polypropylene (PP) or polyamide (PA) is. The film may also be monoaxially or biaxially stretched. The stretching of the film, inter alia, leads to it receiving polarizing properties that can be used as another security feature. The tools required for exploiting these properties, such as polarization filters, are known to the person skilled in the art.

It may also be expedient if the substrate is a multilayer composite, in particular a composite of several different films (composite composite). The films of the composite can be z. B. be formed from the aforementioned plastic materials. Such a composite is characterized by an extremely high stability, which is for the durability of the security element of great advantage. Also, these composite materials can be used in certain climatic regions of the earth with great advantage.

All materials used as a substrate may have additives which serve as authenticity features. It is primarily to think of luminescent, which are preferably transparent in the visible wavelength range and in the non-visible wavelength range by a suitable tool, for. B. a UV or IR radiation emitting radiation source, can be excited to produce a visible or at least detectable luminescence. Of course, the marking layer, ie z. For example, the paints or paints used for the microstructure, the additives mentioned above.

In an advantageous variant of the invention, the marking layer of the see-through security element represents a colored embossing lacquer layer, the layers of which leave it during the embossing, d. H. unembossed areas form the structural elements of the at least one microstructure.

In another, likewise advantageous variant of the invention, the marking layer of the see-through security element is a transparent or translucent embossing lacquer layer which has embossed and subsequently filled with colored material depressions which form the structural elements of the at least one microstructure. The depressions can have any desired shape or outline shape. For these recesses, the term "trenches" is used below.

In a further, likewise advantageous variant of the invention, the marking layer of the see-through security element is a printing layer with areas of high transparency and areas of low transparency, wherein the areas of low light transmission form the structural elements of the at least one microstructure.

In accordance with yet another advantageous variant of the invention, the marking layer of the see-through security element is a microtitle printing layer with areas of high transparency and areas of low light transmission, the areas of low light transmission forming the structural elements of the at least one microstructure. The properties of such microfill printing layers and methods for their preparation are described in more detail below.

The see-through security element preferably has a total thickness of 20 μm or less, more preferably from 3 μm to 10 μm. The structural elements of the microstructure expediently have a characteristic structure spacing of 5 μm or more. Furthermore, according to an advantageous embodiment, it is provided that the structural elements each have a structure size of 1 μm or more, preferably of 3 μm or more. For the profile of the structural elements, height-to-width ratios of about 1: 5 to about 5: 1 are considered to be advantageous, and from about 1: 1 to about 5: 1 are considered to be particularly advantageous.

According to a development of the invention, at least one of optionally a plurality of microstructures is formed by a lamellar structure of a plurality of substantially parallel lamellae. The visual appearance of the microstructures then changes as you rotate or tilting the security element by the relative to the parallel slats changing direction of view.

In the security element, it is particularly preferable to provide a plurality of microstructures formed by lamellar structures, which differ in one or more of the parameters lateral orientation, color, width, height, relief shape and spacing. The differing lamellar structures can advantageously be arranged in the form of patterns, characters or a coding which appear, change or disappear, in particular when the security element is turned or tilted.

According to another development of the invention, at least one of optionally a plurality of microstructures is formed by a multiplicity of recesses with an increased transparency in a marking layer, so that the visual appearance of the microstructure when the security element is rotated or tilted by the viewing direction changing relative to the recesses changed. The plurality of depressions can be arranged with advantage in the form of patterns, characters or a coding, which appear in particular when turning or tilting the security element, change or disappear.

According to a preferred embodiment of the invention, the structural elements are provided in partial areas with an opaque, transparent, semi-transparent, reflective or absorbent coating. The coating may be monolayered or multi-layered and, with particular advantage, a thin-film element with a color-shift effect, ie it may be optically variable. As an example of single-layer thin-film elements, coatings of so-called pearlescent pigments are to be mentioned in the first place. Multilayer thin-film elements are generally referred to as purely dielectric thin-film structures or metallic / dielectric multilayer structures formed. In the multilayer thin-film elements, three-layered interference layer structures (metal / dielectric three-layer structure) are currently particularly preferred.

Furthermore, the structural elements may be provided in partial areas with a metallic coating, with a light-absorbing moth-eye structure or else with a diffractive structure which diffracts substantial parts of the incident light away from the viewer.

It is particularly preferred if the structural elements have an asymmetrically arranged coating, moth-eye structure or diffractive structure. In the case of a coating, the asymmetric arrangement on the structural elements z. B. be achieved by a Schrägbedampfung.

In a further advantageous embodiment of the invention, the see-through security element has a transparent or translucent substrate with a first and an opposite second surface, wherein a transparent mask is applied to the first surface as a microstructure. A congruent see-through mask is applied to the second surface at a predetermined lateral offset of 100 μm or less.

The see-through mask preferably includes a motif in the form of patterns, characters, or a code that is visually discernible only at a particular viewing angle.

With particular advantage, the see-through masks are each formed by an opaque layer with translucent openings, wherein the openings have a size of less than 200 microns, preferably a size of about 3 microns to about 100 microns, and a motif in the form of patterns, characters or a Form coding. The offset of the see-through mask is tuned to the size of the openings and the thickness of the substrate, and is preferably substantially less than 100 μm, for example, only about 20 μm or less, or even only about 10 μm or less.

The see-through security element according to the invention can advantageously have further security elements in order to further increase the security against counterfeiting. For example, the additional security element may be a transparent or semitransparent coating, which is constructed in one or more layers. In the case of the additional coatings, optically variable layers, in particular interference layers, can be used to advantage. The person skilled in the art is sufficiently familiar with purely dielectric thin-film structures, metallic / dielectric multilayer structures and the materials used in each case for the layers of these interference layer systems. Of course, an additional security element can also be regarded as part of the see-through security element according to the invention, in particular if, as in the case of the above-mentioned thin-film elements with color shift effect, the further security element (interference layer structure) is arranged on or under the microstructure. In any case, the synergistic interaction of the microstructure with the additional security element results in a significant increase in the security against counterfeiting and an enhancement of the visual appearance of the see-through security element according to the invention.

The additional coating may be superimposed or underlaid by the microstructure of the see-through security element. A particularly impressive, additional optically variable effect can, for. Example, be obtained when the additional optically variable coating between the transparent or translucent substrate and the microstructure-containing marking layer is arranged. The synergistic interaction of the optically variable microstructure and the additional optically variable coating considerably increases the security against forgery of the see-through security element.

The additional coating may have at least partially machine readable properties. The additional coating also advantageously has magnetic, electrically conductive or luminescent properties.

The additional security element may, however, advantageously also be diffraction structures, kinematic structures or matt structures. For example, holograms may be used as diffractive structures provided with a transparent or semitransparent metal layer or high refractive dielectric coating. Even with these additional security elements, the security against counterfeiting is particularly increased by the fact that the additional security element of the microstructure of the see-through security element is either superimposed or underlaid, or is arranged practically without spatial distance next to the microstructure.

The additional security element can also be in the form of a liquid-crystal layer, in particular as a cholesteric or nematic liquid-crystal layer, or in the form of a multilayer arrangement cholesteric and / or nematic liquid crystals. The formation of the additional security element as a pressure element is possible. The printing element may advantageously contain a color that absorbs and / or emits in the infrared (IR) or ultraviolet wavelength range (fluorescence or phosphorescence), which enables machine detection. Also, the printing element may contain optically variable or iridescent pigments.

Finally, a non-diffractive or diffractive lens structure, for. As a Fresnel lens arrangement, as an additional security element with the microstructure according to the invention can be combined.

The invention also encompasses a method for producing a see-through security element of the type described, in which the see-through security element is provided with at least one microstructure with a visual appearance dependent on viewing angle, which comprises at least one microstructure of an arrangement of a multiplicity of structural elements with a characteristic structural spacing of 1 μm or more, and the see-through security element having a total thickness of 50 μm or less is formed.

The at least one microstructure is formed in the form of a regular, irregular or partially regular arrangement of a plurality of structural elements.

In the method according to the invention, a marking layer is advantageously applied to a transparent or translucent substrate in which the at least one microstructure is formed.

According to a variant of the method, a colored embossing lacquer layer is applied as a marking layer, for example printed on it, and the embossing lacquer layer is structured by means of embossing techniques in such a way that the embossed standstocks, ie. H. unembossed areas form the structural elements of the at least one microstructure.

In another variant of the method, a transparent or translucent embossing lacquer layer is applied as the marking layer, for example printed on it, and recesses are introduced into the embossing lacquer layer by means of embossing techniques. The depressions in the embossing lacquer layer are then filled with colored material, for example a printing ink, so that the filled depressions form the structural elements of the at least one microstructure. The depressions can have any shape and are also referred to below as "trenches".

In a further variant of the method, a printing layer having areas of high light transmission and areas of low light transmission is applied as the marking layer, the areas of low light transmission forming the structural elements of the at least one microstructure.

In principle, various methods are conceivable with which an inventive see-through security element can be produced. Therefore, it will not be discussed further in detail on the known methods.

1. a) eine Werkzeugform bereitgestellt wird, deren Oberfläche eine Anordnung von Erhebungen und Vertiefungen in Gestalt der gewünschten Mikrostruktur aufweist,
2. b) die Vertiefungen der Werkzeugform mit einem härtbaren farbigen oder farblosen Lack befüllt werden,
3. c) das Substrat für eine gute Verankerung des farbigen oder farblosen Lacks vorbehandelt wird,
4. d) die Oberfläche der Werkzeugform mit dem Substrat in Kontakt gebracht wird,
5. e) der in Kontakt mit dem Substrat stehende Lack in den Vertiefungen der Werkzeugform gehärtet und dabei mit dem Substrat verbunden wird, und
6. f) die Oberfläche der Werkzeugform wieder von dem Substrat entfernt wird, so dass der mit dem Substrat verbundene, gehärtete Lack aus den Vertiefungen der Werkzeugform gezogen wird.

As a particularly advantageous variant of the method, however, the micro-deep-pressure method should be mentioned here, in which the microstructure is applied to the substrate by

1. a) a tool mold is provided whose surface has an arrangement of elevations and depressions in the form of the desired microstructure,
2. b) the recesses of the mold are filled with a curable colored or colorless varnish,
3. c) the substrate is pretreated for a good anchoring of the colored or colorless lacquer,
4. d) the surface of the mold is brought into contact with the substrate,
5. e) the lacquer standing in contact with the substrate is hardened in the depressions of the mold and thereby connected to the substrate, and
6. f) the surface of the tool mold is removed again from the substrate, so that the hardened varnish bonded to the substrate is pulled out of the depressions of the tool mold.

For further embodiments of this micro-gravure printing method and the advantages associated therewith, reference is made to the German patent application 10 2006 029 852.7 referenced, the disclosure of which is included in the present application in this respect.

For the microtip printing method, it is particularly preferred if the depressions of the mold are filled in step b) with a radiation-curing lacquer and the lacquer in step e) by applying Radiation, especially with UV radiation, is cured. Further, the paint can be pre-cured with advantage in the recesses of the mold prior to contacting step d).

Advantageously, the microstructure of the mold is formed by microstructure elements having a line width between about 1 μm and about 10 μm. It is also preferred if the microstructure of the tool mold is formed by microstructure elements with a structure depth between about 1 μm and about 10 μm, preferably between about 1 μm and about 5 μm.

In an expedient variant of the method according to the invention, the see-through security element is produced with a total thickness of 20 μm or less, preferably from 3 μm to 10 μm.

Furthermore, at least one microstructure may be formed by a lamellar structure of a plurality of substantially parallel lamellae.

Alternatively, however, it is also conceivable that at least one microstructure in a marking layer is formed by a multiplicity of depressions with an increased light transmission.

In a further development of the method described, the structural elements are provided in partial regions with an opaque, transparent, semitransparent, reflective or absorbing coating, in particular with a metallic coating, a moth-eye structure or a diffractive structure.

In another advantageous embodiment of the method according to the invention, a transparent or translucent substrate having a first surface and an opposing second surface is provided, a see-through mask is applied to the first surface as a microstructure, and a congruent see-through mask with a predetermined lateral offset of 100 μm or less applied to the second surface.

The transparency masks are applied simultaneously to the opposing surfaces of the substrate in an advantageous process management. Alternatively, the see-through masks may also be sequentially applied to the opposing surfaces of the substrate. Particularly preferably, the see-through masks are applied to the opposite sides of the substrate by means of the micro-gravure printing technique described above.

The invention also includes a security paper for the production of security or value documents, such as banknotes, checks, identity cards, certificates or the like, and a data carrier, in particular a branded article, a document of value or the like, wherein the security paper or the data carrier with a security element of described type are equipped.

The described measures ensure that the see-through security elements according to the invention are thin enough to be used in the field of documents of value and that they can be produced economically in the required high quantities with the proposed method. The structure spacing of 1 μm or more, or the structure size of 1 μm or more, ensures that the microstructures are largely achromatic, ie without disturbing color splitting. The optically variable effects can therefore be easily recognized even under unfavorable lighting conditions.

With the see-through security element according to the invention, it is advantageously possible to achieve a series of so-called movement effects which, on the one hand, further improve counterfeiting security and, on the other hand, are visually very appealing to the observer. Characterized in that the see-through security element is subdivided into a plurality of areas in which microstructures are arranged with different viewing angle-dependent tilt effect, can be achieved motion effects, which are also referred to as flip, running or pumping effects. In these effects, the viewer perceives an apparent movement of the observed structure when tilting the see-through security element due to the changing in a defined manner optical impression.

Further embodiments and advantages of the invention are explained below with reference to the figures. For better clarity, a scale and proportioned representation is omitted in the figures.

Fig. 1

eine schematische Darstellung einer Banknote mit einem erfindungsgemäßen Durchsichtssicherheitselement,

Fig. 2

einen Querschnitt durch ein erfindungsgemäßes Durchsichtssicherheitselement mit Jalousiebild,

Fig. 3

einen Querschnitt durch ein Durchsichtssicherheitselement mit Jalousiebild, bei dem die Lamellen in Trapezform ausgebildet sind,

Fig. 4

in (a) und (b) Zwischenschritte bei der Herstellung eines Durchsichtssicherheitselements nach einem Ausführungsbeispiel der Erfindung,

Fig. 5

eine schematische Aufsicht auf ein Durchsichtssicherheitselement nach einem weiteren Ausführungsbeispiel der Erfindung,

Fig. 6

ein Ausschnitt der Banknote der Fig. 1 mit einem erfindungsgemäßen Durchsichtssicherheitselement, in dem die Denomination der Banknote als optisch variables Element wiederholt ist,

Fig. 7

einen Querschnitt durch ein erfindungsgemäßes Durchsichtssicherheitselement mit einer Markierungsschicht, die ein Muster aus Vertiefungen enthält,

Fig. 8

beispielhaft einige Gestaltungen für Vertiefungen, die der Markierungsschicht jeweils eine definierte erhöhte Lichtdurchlässigkeit verleihen, wobei (a) Vertiefungen verschiedener Breite und Tiefe und (b) Vertiefungen mit verschiedenen Umrissformen und Größen zeigt,

Fig. 9

ein erfindungsgemäßes Durchsichtssicherheitselement mit einer symmetrischen Lamellenstruktur, die mit einer asymmetrischen opaken Beschichtung versehen ist,

Fig. 10

ein Sicherheitselement ähnlich dem der Fig. 9, bei dem die Strukturelemente weitere Flächen unterschiedlicher Neigung aufweisen,

Fig. 11

ein Sicherheitselement ähnlich dem der Fig. 9 und Fig. 10 mit Oberflächenstrukturen mit Flächen unterschiedlicher Neigung und einer symmetrischen Metallbeschichtung, wobei das Durchsichtsbild unter senkrechtem Auftreffwinkel des Metalldampfes wirksam wird,

Fig. 12

ein Sicherheitselement ähnlich dem der Fig. 9 bis Fig. 11, bei dem die Strukturelemente in Teilbereichen mit lichtabsorbierenden Mottenaugenstrukturen versehen sind,

Fig. 13

ein Durchsichtssicherheitselement mit auf gegenüberliegenden Oberflächen eines Substrats mit einem vorbestimmten Versatz angeordneten Durchsichtsmasken, wobei das Motiv der Durchsichtsmasken nur aus einer bestimmten Betrachtungsrichtung in Durchsicht visuell erkennbar ist (a), während das Durchsichtssicherheitselement aus anderen Betrachtungsrichtungen opak erscheint (b),

Fig. 14

eine schematische Aufsicht auf ein Durchsichtssicherheitselement nach noch einem weiteren Ausführungsbeispiel der Erfindung, und

Fig. 15

einen Querschnitt durch ein weiteres erfindungsgemäßes Sicherheitselement, das mit einer optisch variablen Beschichtung versehene Mikrostrukturelemente aufweist.

Show it:

Fig. 1

a schematic representation of a banknote with a see-through security element according to the invention,

Fig. 2

a cross section through an inventive see-through security element with blinds,

Fig. 3

a cross section through a see-through security element with blind shape, in which the slats are formed in a trapezoidal shape,

Fig. 4

in (a) and (b) intermediate steps in the production of a see-through security element according to an embodiment of the invention,

Fig. 5

a schematic plan view of a see-through security element according to another embodiment of the invention,

Fig. 6

a section of the banknote of Fig. 1 with a see-through security element according to the invention, in which the denomination of the banknote is repeated as an optically variable element,

Fig. 7

a cross-section through an inventive see-through security element with a marking layer containing a pattern of wells,

Fig. 8

by way of example, some designs for recesses which each give the marking layer a defined increased light transmittance, wherein (a) shows recesses of different width and depth and (b) recesses with different outline shapes and sizes,

Fig. 9

an inventive see-through security element with a symmetrical lamellar structure, which is provided with an asymmetrical opaque coating,

Fig. 10

a security element similar to the one Fig. 9 in which the structural elements have further surfaces of different inclination,

Fig. 11

a security element similar to the one FIGS. 9 and 10 with surface structures with surfaces of different inclination and a symmetrical metal coating, the transparency being effective at a normal angle of incidence of the metal vapor,

Fig. 12

a security element similar to the one Fig. 9 to Fig. 11 in which the structural elements are provided in partial regions with light-absorbing moth-eye structures,

Fig. 13

a see-through security element having see-through masks on opposite surfaces of a substrate at a predetermined offset, the subject of the see-through masks being visually discernible only from a particular viewing direction (a), while the see-through security element appears opaque from other viewing directions (b),

Fig. 14

a schematic plan view of a see-through security element according to yet another embodiment of the invention, and

Fig. 15

a cross section through another inventive security element having provided with an optically variable coating microstructure elements.

The invention will now be explained using the example of a security element for a banknote. Fig. 1 shows a schematic representation of a banknote 10 with a see-through security element 12 with a blind image, which is arranged over a see-through area 14, such as a window area or a through opening of the banknote 10. The through opening may after the preparation of the substrate of the banknote 10, z. B. be produced by punching or laser beam cutting. But it is also conceivable to produce the through opening during the production of the banknote substrate, as shown in the WO 03/054297 A2 is described. In that regard, the disclosure of the WO 03/054297 A2 included in the present application.

As explained in more detail below, the shutter image of the see-through security element 12 shows a different visual appearance, depending on the viewing direction. For example, the security element 12 may appear structureless and bright when viewed vertically, while dark marks in the form of patterns, characters or encodings emerge when the banknote is tilted or rotated. In other designs, the markings are already visible when viewed vertically and disappear or change when turning or tilting the bill.

Essential for the use of the see-through security element 12 in the banknote 10 or other securities is its small overall thickness of less than 50 microns. Preferably, the see-through security element even has an even smaller layer thickness of only about 20 μm or even only about 3 μm to 10 μm. The invention provides several options for producing visually appealing shutter images with such low overall thicknesses.

A first possibility to produce a thin see-through security element with blind image is based on the cross section through the security element 12 in Fig. 2 illustrated. In the exemplary embodiment shown, first a thin layer of a colored embossing lacquer 22 is applied to a transparent substrate 20. The embossing lacquer layer 22 is then structured by means of embossing techniques in such a way that a lamellar structure is formed from a multiplicity of substantially parallel, individually standing lamellae 24.

When viewed parallel to the slats 24, that is, in the direction of view 26, the security element 12 appears to be substantially transparent when viewed. On the other hand, if the observer tilts the security element 12 out of the parallel viewing direction, for example in the direction of view 28, then the lamella 24 blocks the view, ie. H. the security element 12 appears opaque to the viewer.

The lamellar structure represents a regular arrangement of a plurality of lamellae 24 with a characteristic structure spacing, which according to the invention is 1 μm or more, so that the lamellae 24 do not cause color splitting in the visible spectral range by wavelength-dependent diffraction effects. In the embodiment of Fig. 2 is the distance between adjacent slats 24 at 5 microns, the structure size, ie the width of the individual slats at 2.5 microns. The height of the embossed fins 24 is 5 microns, so that there is a height-to-width ratio of 2: 1. In general, this ratio is between about 1: 5 and about 5: 1, preferably around or above 1: 1 up to about 5: 1.

That in the Fig. 2 shown rectangular profile of the fins 24 represents an idealization of the actual conditions in an embossed lacquer layer. In In practice, the transitions at the top and bottom edges of the slats are rounded to some extent and the edges of the slats 24 are not completely vertical. Also, a targeted design of the blades 24 in trapezoidal shape with flanks of a different slope of 90 °, such as in Fig. 3 shown, comes into consideration. The slope of the flanks is preferably between about 70 ° and about 85 °. Again, in practice, the transitions at the top and bottom edges of the slats are not completely sharp, but slightly rounded.

The brightness of the security element 12 in view can be adjusted by the ratio of slat width to slat spacing in a wide range. Also, the color impression can be selected largely freely by the color of the embossing lacquer and the transparent or translucent substrate.

Instead of a colored embossing lacquer 22, a layer of a colorless embossing lacquer 32 may also be applied to the substrate 20, as in FIG Fig. 4 shown. The colorless embossing lacquer 32 is then first structured with an embossing tool in such a way that depressions or trenches 34 in the form of the desired shade image arise, as in FIG Fig. 4 (a) illustrated. Subsequently, the recesses 34 are filled with color 36, as in Fig. 4 (b) shown to produce a shutter image with the desired color impression.

The use of embossing technology allows in addition to the production of Venetian blind films with a very small total thickness of 50 microns or less, also in a simple way the generation of locally differently oriented lamellar structures on the same security element. Fig. 5 shows by way of illustration a schematic plan view of a see-through security element 40 according to a further exemplary embodiment of the invention. The security element 40 has in a first region 42 a first lamellar structure, the parallel lamellae 44 in the view of Fig. 5 run vertically. In second areas 46, a second lamellar structure is provided which has the same lamella width and the same lamella spacing as the first lamellar structure, but whose likewise parallel lamellae 48 are oriented at right angles to the lamellae 44.

When viewed vertically, the areas 42 and 46 differ in their visual appearance due to their equal area coverage practically not, the security element 40 appears structureless and bright. If the security element now tilted by a certain angle to the right or left (tilt direction 50), so the tilted louvers 44 obstruct the observer, while the spaces between the parallel louvers 48 in the regions 46 still permit a view. For the viewer, bright circles 46 thus appear in front of a dark background 42.

On the other hand, if the observer tilts the security element forwards or backwards (tilting direction 52), the now tilted louvers 48 obstruct the view, while the spaces between the louvers 44 keep the area 42 transparent. The viewer now sees dark circles 46 against a light background 42.

In a not further illustrated embodiment it is provided that the security element of Fig. 5 an additional transparent or semitransparent, z. B. optically variable coating, the z. B. between the substrate and the microstructure or on the microstructure is arranged. By this measure, the counterfeit security of in Fig. 5 shown security elements further increased.

The simple geometric pattern of Fig. 5 can of course be extended to more complex patterns, characters or encodings. For example, the denomination 16 of the currency attaining banknote 10 may be repeated in the see-through security element 12 in the form of areas 60, 62 with different lamination orientation, as in FIG Fig. 6 shown. As explained in the previous embodiment, the see-through security element 12 appears structureless when viewed vertically, while the tilting of the banknote depending on the direction of tilting the digit sequence "10" emerges bright against a dark background or dark against a light background.

Another see-through security element according to yet another embodiment of the invention is in Fig. 14 shown. The security element 140 of the Fig. 14 basically has a similar structure as the security elements of Fig. 5 and Fig. 6 on why reference is made to the statements made to these figures.

The main difference of the see-through security element 140 with respect to the see-through security elements of Fig. 5 and Fig. 6 is that the areas of differently oriented lamellar structures are much less sharply demarcated. For example, while the areas 42 and 46 of the security element 40 of the Fig. 5 are arranged perpendicular to each other, the fins 141,147 of the security element 140 of the Fig. 14 in most areas only a non-linear course, the differences in the direction of adjacent areas are relatively small. How out Fig. 14 can be seen, the meander-shaped fins 141 in the areas 144 and 145, however, a course that of the in Fig. 14 running from top to bottom Preferred direction, which is predetermined by the fins 147 of the area 143, clearly deviates.

When viewed vertically, the areas 143 and 144 and 145 practically do not differ in their visual appearance due to their equal area coverage, the security element 140 appears substantially featureless and bright. However, if the security element 140 is tilted by a certain angle to the right or left (FIG. Tilting direction 150), so the tilted slats 147 adjust the viewer's view, while the interstices of the slats 141 in the areas 144 and 145 at least partially allow a view to a considerable extent. In contrast to the tilting of the security element 40 of the Fig. 5 very sharply demarcated areas 42 and 46 results between the areas 142,143,146 and 144,145 of the security element 140 of the Fig. 14 a continuous transition with respect to the orientation of the slats (curvature), whereby even when tilted in the direction 150, the areas 144 and 145 are less pronounced from the areas 142,143 and 146. For the observer, when the security element 140 is tilted, areas with less transparency thus result, which gradually change into areas with essentially unchanged transparency. The regions of low transparency are therefore relatively evenly transferred to the brighter areas for the viewer when the tilted security element 140 is tilted.

When tilted in a direction 152 which is substantially perpendicular to the direction 150, the interspaces of the louvers 147 keep the region 143 translucent, while the now tilted louvers 141 of the regions 144, 145 substantially obstruct the view. Accordingly sees the Observers now see dark areas 144, 145, which continuously merge into the bright areas 142, 143, and 146.

One according to Fig. 14 trained security element 140 has a very high security against counterfeiting, since the complex curved lamellar structures can not be composed of individual, possibly available slats or easily readjusted. Furthermore, the continuous light / dark transitions are perceived by a viewer as visually very appealing.

Also the security element of Fig. 14 may have an optically variable coating, the z. B. between the substrate and the microstructure or on the microstructure is arranged. The security against forgery of such a security element not shown is further increased by such a measure.

The see-through security elements according to the invention can, instead of venetian blinds whose microstructures are formed by parallel lamellae, also contain other microstructures, for example microstructures of a multiplicity of depressions with increased translucency.

Of course, it is also conceivable that the substantially parallel arrangement of the slats is replaced at least in areas by a non-parallel arrangement, which is equivalent to an increase in the security against counterfeiting of the security element, since such structures can be technically very difficult to adjust.

For illustration shows Fig. 7 a see-through security element 70, in which on a transparent substrate 72 initially a continuous dark embossing lacquer layer 74 is applied. Embossed in the embossing lacquer layer 74 are a multiplicity of recesses 76 in which the light transmittance of the embossing lacquer layer 74 is increased due to the locally reduced layer thickness. The recesses 76 are arranged so that they viewed together as viewed form a motif that appears and disappears depending on the viewing angle.

Due to the high resolution of the embossing technique and the low layer thicknesses, very fine designs and complex motifs can be realized. The representation of the motifs is not limited to two-tone representations (light / dark), but rather, as described below, half-tone representations can be realized. In order to avoid unwanted color splitting, the characteristic spacing of the recesses is also 1 μm or more in the designs in which the microstructures comprise a multiplicity of depressions. The lateral dimensions of the depressions are advantageously also about 1 μm or more.

By different density (number of wells of a particular shape per surface element), depth or by different shape and size of the wells 76 different levels of gray can be realized in the visual impression. FIGS. 8 (a) and (b) show for this purpose some embodiments for depressions 76a, 76b, 76c of different widths and depths as well as depressions 78 with different outline shapes and sizes, which in each case give the embossing lacquer layer a defined increased transparency and can therefore be used to construct halftone images. Realistic halftone images can generally be generated with only a few gray levels, so that a low level of color Number of different pit shapes, sizes and depths is sufficient.

The microstructures (lamellae or depressions) can be produced as described by embossing, in particular by embossing into a UV-curable embossing lacquer or a thermoplastic lacquer. As colors for the embossing lacquer soluble dyes, but also pigment dyes can be used.

Alternatively, printing techniques that are capable of lining up very finely structured opaque and non-opaque areas can also be used to produce the microstructures. The desired effects can be obtained with sufficiently low overall thickness with any printing technique that is capable of producing an approximately 3 μm to 20 μm thick layer with recesses or trenches with diameters between 1 μm and 30 μm.

Particularly advantageous may be used in the co-pending German patent application 10 2006 029 852.7 micro-gravure printing technology, which combines the advantages of printing and embossing technologies. Briefly, in micro-gravure printing technology, a tool mold is provided whose surface has an arrangement of elevations and depressions in the form of the desired microstructure. The recesses of the mold are filled with a curable colored or colorless varnish, and the support to be printed is pretreated for a good anchorage of the varnish. Then, the surface of the mold is brought into contact with the carrier, and the paint in contact with the carrier is hardened in the recesses of the mold while being connected to the carrier. Subsequently, the surface of the Tool mold again removed from the carrier, so that the bonded to the carrier, hardened paint is pulled out of the recesses of the mold.

For a more detailed description of the micro-gravure printing process and the associated advantages, reference is made to the aforementioned German patent application 10 2006 029 852.7, the disclosure of which is incorporated into the present application in this respect.

The structural elements of the microstructures, for example the slats of the FIGS. 2 to 6 or the pits of the FIGS. 7 and 8 , In some areas may also be provided with an opaque, a reflective or an absorbent coating.

By means of structural elements of locally different geometry or by means of structural elements with surfaces of different inclination, it is also possible in this way to produce transparency images whose visibility depends on the viewing angle.

For illustration, the embodiment of the Fig. 9 a security element 80 having a lamellar structure of a plurality of substantially parallel, transparent lamellae 82, which, as described above, formed by means of an embossing lacquer layer, a printing layer or a microtip printing layer. The symmetrical lamellar structure 82 is asymmetrically provided with an opaque coating 84, as in FIG Fig. 9 shown. In this case, the asymmetric coating z. B. by oblique vapor deposition by means of a known vapor deposition method, for. B. Physical Vapor Deposition (PVD) done. The intended for Schrägbedampfung particle steam then strikes under an oblique, ie not with respect to the substrate surface vertical angle, on the microstructure elements or the substrate surface. Due to the asymmetry of the coating, viewing through the transparent lamellae 82 is possible from the viewing direction 88, while the opaque coating 84 obstructs the viewing on the lamellae 82 from the viewing direction 86, so that the security element 80 appears opaque from the viewing direction 86 in the partial region shown. By suitable arrangement of the lamellae 82 and the coating 84, it is thus possible, for example, to produce a see-through image which becomes visible only when the security element is tilted in the viewing direction 88.

Also, the embodiment of Fig. 10 shows a microstructure 90 with symmetrical microstructure elements and with a z. B. generated by oblique deposition asymmetric coating 92, in which the microstructure elements, however, have more surfaces of different inclination 94, 96, and thus increase the freedom of design for the design of the transparencies.

By means of surface structures 100 with surfaces of different inclination, it is also possible to produce transparent images which become effective by means of coating 102 at a vertical angle of incidence of the particle vapor, in particular of the metal vapor, as is the case with the exemplary embodiment of FIG Fig. 11 illustrated.

Instead of an opaque or reflective coating, it is also possible to provide an absorption structure on the individual structural elements. For example, shows Fig. 12 a security element 110 with a microstructure 112 with different structural elements, which are provided in partial areas with so-called moth eye structures 114, which are effective light traps for the incident light.

In other configurations, the features of the microstructure 112 are provided with diffraction gratings which diffract substantial portions of the light incident at a certain angle in directions out of viewing direction. Also by such a combination of a geometric microstructure with a characteristic element size of 3 microns to 50 microns with a diffractive structure with a characteristic element size of about 300 nm to about 1000 nm effective see-through tilting can be realized.

It is understood that, if desired, the structures may additionally be provided perpendicularly or obliquely with a reflective layer or with a layer having a refractive index which differs significantly from the structural elements.

Such a see-through security element with an additional coating is in Fig. 15 shown. The security element 160 of Fig. 15 has a on a transparent or translucent material 161, z. Example, a plastic film made of PET, applied microstructure 170, which in turn from a plurality of microstructure elements 162 and 163 and an overlying optically variable coating with layers 164,165 and 166 is formed. How out Fig. 15 can be seen, the symmetrical to the plane of symmetry 169 arranged microstructure elements 162 and 163 form a sawtooth-shaped relief structure. The relief structure can also be understood as a lattice structure with a relatively small grid angle α. In the example shown, the grating angle α is approximately 20 °, although even smaller angles of up to approximately 5 ° or larger angles up to approximately 45 ° are conceivable. At the in Fig. 15 shown embodiment, the height h of the individual grid lines is about 5 microns.

Above the microstructure, a three-layer optically variable coating is arranged. The individual layers 164, 165 and 166 were applied by vapor deposition from a direction substantially perpendicular to the substrate surface. Ideally, the flanks 167 of the relief structure arranged parallel to the vapor deposition direction have no optically variable coating. The three-layer coating with color shift effect is a metallic / dielectric structure with the following structure. On the relief structures produced from a UV embossing lacquer, a layer 164 of aluminum is preferably first applied by vapor deposition. The layer serves as a reflector and has a layer thickness of about 10 nm to 100 nm, preferably of about 30 nm. In addition, a layer of SiO ₂ with a layer thickness of 100 nm to 1000 nm, more preferably with a layer thickness of about 200 nm to 600 nm is usually applied by vapor deposition. The thickness of the SiO ₂ layer determines the color shift effect to be perceived later by the observer for the structure. Finally, a semitransparent layer of chromium is deposited over the layer of SiO ₂ , which has a layer thickness of about 3 nm to 10 nm. The three-layer structure thus obtained has a color shift effect from green (top view, direction 177) to magenta (oblique viewing angle, direction 178, 179).

In the Fig. 15 shown embodiment of the see-through security element according to the invention shows in plan view (direction 177) for the provided with the microstructure elements 162 and 163 areas of the microstructure 170 substantially the same color for the viewer. When the security element is tilted from the vertical viewing direction 177 to an oblique viewing direction 178 or 179, the color impression for the areas of the security element 160 provided with the microstructure elements 162 and 163 changes due to the then different On the other hand, the angle between the irradiated light and the interference layer arrangement with the layers 164, 166, 166 present on the microstructure elements 162 and 163, respectively, clearly shows, wherein the plane 169 represents a sharp boundary between the regions perceived differently colored by the viewer with the elements 162 and 163, respectively.

The security element 160 is extraordinarily tamper-proof by the superimposition of a relief structure and a coating with a color shift effect and the resulting synergistic effects. In addition, such an optically variable security element is very appealing to the viewer, so that a security element according to this embodiment has a particularly high recognition value.

Another embodiment of the invention is in Fig. 13 illustrated. The see-through security element 120 shown there has a transparent or translucent substrate 122 having a first surface and an opposite second surface, wherein a see-through mask 124 is applied to the first surface as a microstructure. The see-through mask 124 is formed by an opaque layer 126 with translucent openings 128 having a size below 200 microns, preferably having a size of about 5 microns to about 100 microns, wherein the arrangement of the openings a motif in the form of patterns, characters or forms an encoding.

A congruent see-through mask 130 is applied to the opposite second surface of the substrate 122 with a certain lateral offset Δ of less than 100 μm, for example of only 10 μm.

As in Figs. 13 (a) and 13 (b) By suitable choice, the size of the openings 128, the thickness of the substrate 122 and the offset Δ It can be achieved that the subject of the transparency masks 124, 130 can be visually recognized only from a certain viewing direction 132, while the see-through security element 120 appears opaque from other viewing directions 134.

The opaque layers of the see-through masks can be produced by known printing processes, by embossing in ink layers, by embossing wells in transparent lacquer and then filling the wells with ink, by metallization / demetalization and preferably by the above-mentioned microtiping technique according to German patent application 10 2006 029 852.7 become. It is also conceivable in principle that the see-through mask on one side of the substrate z. B. is obtained by a stamping technique, the see-through mask on the other side of the substrate but by a suitable metallization or Demetallisierungstechnik. When demetallizing various laser techniques can be used with advantage, since they can be obtained with high-resolution transparency masks.

In order to achieve the required small offset of the transparent masks, they can be applied in particular simultaneously to the opposite surfaces of the substrate. On the other hand, if the see-through masks are applied successively, special attention must be paid to the registration of the microstructures, in particular their adaptation to the size of the openings 128. If larger openings 128 are used, the registration is less critical, so that in this case application methods with a larger clearance can be used.

Also in the case of in Fig. 13 shown embodiment, it is generally conceivable, an additional coating, for. As an optically variable, semi-transparent thin-film arrangement, to be arranged on or below the see-through masks. Advantageously, the additional coating as well as the transparency mask is structured, so has the same motif, which z. B. can be achieved by demetallization techniques.

Unless the transparency masks, as in Fig. 13 shown, are congruent, but have different subjects, ie have different areas of transparency, interesting Moire effects and effects can be achieved, which depend on the tilt or rotation angle when tilting or turning the see-through security element. However, these special effects are not discussed further in the present application.

• Absatz 1. Durchsichtssicherheitselement für Sicherheitspapiere, Wertdokumente und dergleichen mit zumindest einer Mikrostruktur mit einem in Durchsicht betrachtungswinkelabhängigen visuellen Erscheinungsbild, dadurch gekennzeichnet, dass die zumindest eine Mikrostruktur aus einer Anordnung einer Vielzahl von Strukturelementen mit einem charakteristischen Strukturabstand von 1 µm oder mehr gebildet ist und dass das Durchsichtssicherheitselement eine Gesamtdicke von 50 µm oder weniger aufweist.
• Absatz 2. Durchsichtssicherheitselement nach Absatz 1, dadurch gekennzeichnet, dass das Durchsichtssicherheitselement ein transparentes oder transluzentes Substrat und eine auf dem Substrat aufgebrachte Markierungsschicht aufweist, die die zumindest eine Mikrostruktur enthält.
• Absatz 3. Durchsichtssicherheitselement nach Absatz 2, dadurch gekennzeichnet, dass die Markierungsschicht eine gefärbte Prägelackschicht ist, deren bei der Prägung stehen gelassenen Bereiche die Strukturelemente der zumindest einen Mikrostruktur bilden.
• Absatz 4. Durchsichtssicherheitselement nach Absatz 2, dadurch gekennzeichnet, dass die Markierungsschicht eine transparente oder transluzente Prägelackschicht ist, die geprägte und nachfolgend mit gefärbtem Material gefüllte Vertiefungen aufweist, die die Strukturelemente der zumindest einen Mikrostruktur bilden.
• Absatz 5. Durchsichtssicherheitselement nach Absatz 2, dadurch gekennzeichnet, dass die Markierungsschicht eine Druckschicht mit Bereichen hoher Lichtdurchlässigkeit und mit Bereichen niedriger Lichtdurchlässigkeit ist, wobei die Bereiche niedriger Lichtdurchlässigkeit die Strukturelemente der zumindest einen Mikrostruktur bilden.
• Absatz 6. Durchsichtssicherheitselement nach Absatz 2, dadurch gekennzeichnet, dass die Markierungsschicht eine Mikrotiefdruckschicht mit Bereichen hoher Lichtdurchlässigkeit und mit Bereichen niedriger Lichtdurchlässigkeit ist, wobei die Bereiche niedriger Lichtdurchlässigkeit die Strukturelemente der zumindest einen Mikrostruktur bilden.
• Absatz 7. Durchsichtssicherheitselement nach wenigstens einem der Absätze 1 bis 6, dadurch gekennzeichnet, dass das Durchsichtssicherheitselement eine Gesamtdicke von 20 µm oder weniger, bevorzugt von 3 µm bis 10 µm, aufweist.
• Absatz 8. Durchsichtssicherheitselement nach wenigstens einem der Absätze 1 bis 7, dadurch gekennzeichnet, dass die Strukturelemente einen charakteristischen Strukturabstand von 5 µm oder mehr aufweisen.
• Absatz 9. Durchsichtssicherheitselement nach wenigstens einem der Absätze 1 bis 8, dadurch gekennzeichnet, dass die Strukturelemente eine Strukturgröße von 1 µm oder mehr, vorzugsweise von 3 µm oder mehr, aufweisen.
• Absatz 10. Durchsichtssicherheitselement nach wenigstens einem der Absätze 1 bis 9, dadurch gekennzeichnet, dass die Strukturelemente ein Höhen-zu-Breiten-Verhältnis von etwa 1:5 bis zu etwa 5:1, besonders bevorzugt von etwa 1:1 bis zu etwa 5:1, aufweisen.
• Absatz 11. Durchsichtssicherheitselement nach wenigstens einem der Absätze 1 bis 10, dadurch gekennzeichnet, dass zumindest eine Mikrostruktur durch eine Lamellenstruktur aus einer Vielzahl von im Wesentlichen parallel verlaufenden Lamellen gebildet ist.
• Absatz 12. Durchsichtssicherheitselement nach Absatz 11, dadurch gekennzeichnet, dass mehrere durch Lamellenstrukturen gebildete Mikrostrukturen vorgesehen sind, die sich in einem oder mehreren der Parameter laterale Orientierung, Farbe, Breite, Höhe, Reliefform und Abstand unterscheiden.
• Absatz 13. Durchsichtssicherheitselement nach Absatz 12, dadurch gekennzeichnet, dass die sich unterscheidenden Lamellenstrukturen in Form von Mustern, Zeichen oder einer Codierung angeordnet sind.
• Absatz 14. Durchsichtssicherheitselement nach wenigstens einem der Absätze 1 bis 13, dadurch gekennzeichnet, dass zumindest eine Mikrostruktur in einer Markierungsschicht durch eine Vielzahl von Vertiefungen mit einer erhöhten Lichtdurchlässigkeit gebildet ist.
• Absatz 15. Durchsichtssicherheitselement nach Absatz 14, dadurch gekennzeichnet, dass die Vielzahl von Vertiefungen in Form von Mustern, Zeichen oder einer Codierung angeordnet sind.
• Absatz 16. Durchsichtssicherheitselement nach wenigstens einem der Absätze 1 bis 15, dadurch gekennzeichnet, dass die Strukturelemente in Teilbereichen mit einer opaken, transparenten, semitransparenten, reflektierenden oder absorbierenden Beschichtung versehen sind.
• Absatz 17. Durchsichtssicherheitselement nach Absatz 16, dadurch gekennzeichnet, dass die Beschichtung mehrschichtig, insbesondere dreischichtig, ausgebildet ist.
• Absatz 18. Durchsichtssicherheitselement nach Absatz 16 oder 17, dadurch gekennzeichnet, dass die Beschichtung als Dünnschichtelement mit Farbkippeffekt ausgebildet ist.
• Absatz 19. Durchsichtssicherheitselement nach wenigstens einem der Absätze 1 bis 18, dadurch gekennzeichnet, dass die Strukturelemente in Teilbereichen mit einer metallischen Beschichtung versehen sind.
• Absatz 20. Durchsichtssicherheitselement nach wenigstens einem der Absätze 1 bis 19, dadurch gekennzeichnet, dass die Strukturelemente in Teilbereichen mit einer Mottenaugenstruktur versehen sind.
• Absatz 21. Durchsichtssicherheitselement nach wenigstens einem der Absätze 1 bis 20, dadurch gekennzeichnet, dass die Strukturelemente in Teilbereichen mit einer diffraktiven Struktur versehen sind, die wesentliche Teile des einfallenden Lichts in Richtungen außerhalb der Betrachtungsrichtung beugt.
• Absatz 22. Durchsichtssicherheitselement nach wenigstens einem der Absätze 16 bis 21, dadurch gekennzeichnet, dass die Strukturelemente eine asymmetrisch angeordnete Beschichtung, Mottenaugenstruktur oder diffraktive Struktur aufweisen.
• Absatz 23. Durchsichtssicherheitselement nach wenigstens einem der Absätze 1 bis 22, dadurch gekennzeichnet, dass das Durchsichtssicherheitselement ein transparentes oder transluzentes Substrat mit einer ersten und einer gegenüberliegenden zweiten Oberfläche aufweist, wobei als Mikrostruktur eine Durchsichtsmaske auf die erste Oberfläche aufgebracht ist, und eine deckungsgleiche Durchsichtsmaske mit einem vorbestimmten lateralen Versatz von 100 µm oder weniger auf die zweite Oberfläche aufgebracht ist.
• Absatz 24. Durchsichtssicherheitselement nach Absatz 23, dadurch gekennzeichnet, dass die Durchsichtsmaske ein Motiv in Form von Mustern, Zeichen oder einer Codierung enthält, das nur unter einem bestimmten Betrachtungswinkel in Durchsicht visuell erkennbar ist.
• Absatz 25. Durchsichtssicherheitselement nach Absatz 23 oder 24, dadurch gekennzeichnet, dass die Durchsichtsmasken jeweils durch eine opake Schicht mit lichtdurchlässigen Öffnungen mit einer Größe von kleiner 200 µm, vorzugsweise mit einer Größe von etwa 3 µm bis etwa 100 µm, gebildet sind, wobei die Öffnungen ein Motiv in Form von Mustern, Zeichen oder einer Codierung bilden.
• Absatz 26. Verfahren zur Herstellung eines Durchsichtssicherheitselements nach einem der Absätze 1 bis 25, bei dem das Durchsichtssicherheitselement mit zumindest einer Mikrostruktur mit einem in Durchsicht betrachtungswinkelabhängigen visuellen Erscheinungsbild versehen wird, die zumindest eine Mikrostruktur aus einer Anordnung einer Vielzahl von Strukturelementen mit einem charakteristischen Strukturabstand von 1 µm oder mehr gebildet wird und das Durchsichtssicherheitselement mit einer Gesamtdicke von 50 µm oder weniger erzeugt wird.
• Absatz 27. Verfahren nach Absatz 26, dadurch gekennzeichnet, dass auf ein transparentes oder transluzentes Substrat eine Markierungsschicht aufgebracht wird, in der die zumindest eine Mikrostruktur ausgebildet wird.
• Absatz 28. Verfahren nach Absatz 27, dadurch gekennzeichnet, dass als Markierungsschicht eine gefärbte Prägelackschicht aufgebracht wird und die Prägelackschicht mittels Prägetechniken so strukturiert wird, dass die bei der Prägung stehen gelassenen Bereiche die Strukturelemente der zumindest einen Mikrostruktur bilden.
• Absatz 29. Verfahren nach Absatz 27, dadurch gekennzeichnet, dass als Markierungsschicht eine transparente oder transluzente Prägelackschicht aufgebracht wird, in die Prägelackschicht mittels Prägetechniken Vertiefungen eingebracht und die eingebrachten Vertiefungen mit gefärbtem Material gefüllt werden, so dass die gefüllten Vertiefungen die Strukturelemente der zumindest einen Mikrostruktur bilden.
• Absatz 30. Verfahren nach Absatz 27, dadurch gekennzeichnet, dass als Markierungsschicht eine Druckschicht mit Bereichen hoher Lichtdurchlässigkeit und mit Bereichen niedriger Lichtdurchlässigkeit aufgebracht wird, wobei die Bereiche niedriger Lichtdurchlässigkeit die Strukturelemente der zumindest einen Mikrostruktur bilden.
• Absatz 31. Verfahren nach Absatz 26 oder 27, dadurch gekennzeichnet, dass die Mikrostruktur auf das Substrat aufgebracht wird, indem
  1. a) eine Werkzeugform bereitgestellt wird, deren Oberfläche eine Anordnung von Erhebungen und Vertiefungen in Gestalt der gewünschten Mikrostruktur aufweist,
  2. b) die Vertiefungen der Werkzeugform mit einem härtbaren farbigen oder farblosen Lack befüllt werden,
  3. c) das Substrat für eine gute Verankerung des farbigen oder farblosen Lacks vorbehandelt wird,
  4. d) die Oberfläche der Werkzeugform mit dem Substrat in Kontakt gebracht wird,
  5. e) der in Kontakt mit dem Substrat stehende Lack in den Vertiefungen der Werkzeugform gehärtet und dabei mit dem Substrat verbunden wird, und
  6. f) die Oberfläche der Werkzeugform wieder von dem Substrat entfernt wird, so dass der mit dem Substrat verbundene, gehärtete Lack aus den Vertiefungen der Werkzeugform gezogen wird.
• Absatz 32. Verfahren nach Absatz 31, dadurch gekennzeichnet, dass die Vertiefungen der Werkzeugform in Schritt b) mit einem strahlungshärtenden Lack befüllt werden und der Lack in Schritt e) durch Beaufschlagung mit Strahlung, insbesondere mit UV-Strahlung, gehärtet wird.
• Absatz 33. Verfahren nach Absatz 31 oder 32, dadurch gekennzeichnet, dass der Lack in den Vertiefungen der Werkzeugform vor dem In-Kontakt-Bringen des Schritts d) vorgehärtet wird.
• Absatz 34. Verfahren nach wenigstens einem der Absätze 31 bis 33, dadurch gekennzeichnet, dass die Mikrostruktur der Werkzeugform durch Mikrostrukturelemente mit einer Strichstärke zwischen etwa 1 µm und etwa 10 µm gebildet wird.
• Absatz 35. Verfahren nach wenigstens einem der Absätze 31 bis 34, dadurch gekennzeichnet, dass die Mikrostruktur der Werkzeugform durch Mikrostrukturelemente mit einer Strukturtiefe zwischen etwa 1 µm und etwa 10 µm, vorzugsweise zwischen etwa 1 µm und etwa 5 µm, gebildet wird.
• Absatz 36. Verfahren nach wenigstens einem der Absätze 26 bis 35, dadurch gekennzeichnet, dass das Durchsichtssicherheitselement mit einer Gesamtdicke von 20 µm oder weniger, bevorzugt von 3 µm bis 10 µm, erzeugt wird.
• Absatz 37. Verfahren nach wenigstens einem der Absätze 26 bis 36, dadurch gekennzeichnet, dass zumindest eine Mikrostruktur durch eine Lamellenstruktur aus einer Vielzahl von im Wesentlichen parallel verlaufenden Lamellen gebildet wird.
• Absatz 38. Verfahren nach wenigstens einem der Absätze 26 bis 37, dadurch gekennzeichnet, dass zumindest eine Mikrostruktur in einer Markierungsschicht durch eine Vielzahl von Vertiefungen mit einer erhöhten Lichtdurchlässigkeit gebildet wird.
• Absatz 39. Verfahren nach wenigstens einem der Absätze 26 bis 38, dadurch gekennzeichnet, dass die Strukturelemente in Teilbereichen mit einer opaken, transparenten, semitransparenten, reflektierenden oder absorbierenden Beschichtung versehen werden, insbesondere mit einer metallischen Beschichtung, einer Mottenaugenstruktur oder einer diffraktiven Struktur.
• Absatz 40. Verfahren nach Absatz 39, dadurch gekennzeichnet, dass die Strukturelemente mit einer asymmetrischen Beschichtung, Mottenaugenstruktur oder diffraktiven Struktur versehen werden.
• Absatz 41. Verfahren nach wenigstens einem der Absätze 26 bis 40, dadurch gekennzeichnet, dass ein transparentes oder transluzentes Substrat mit einer ersten und einer gegenüberliegenden zweiten Oberfläche bereitgestellt wird, als Mikrostruktur eine Durchsichtsmaske auf die erste Oberfläche aufgebracht wird, und eine deckungsgleiche Durchsichtsmaske mit einem vorbestimmten lateralen Versatz von 100 µm oder weniger auf die zweite Oberfläche aufgebracht wird.
• Absatz 42. Verfahren nach Absatz 41, dadurch gekennzeichnet, dass die Durchsichtsmasken gleichzeitig auf die sich gegenüberliegenden Oberflächen des Substrats aufgebracht werden.
• Absatz 43. Verfahren nach Absatz 41, dadurch gekennzeichnet, dass die Durchsichtsmasken nacheinander auf die sich gegenüberliegenden Oberflächen des Substrats aufgebracht werden.
• Absatz 44. Verfahren nach wenigstens einem der Absätze 41 bis 43, dadurch gekennzeichnet, dass die Durchsichtsmasken mittels Mikrotiefdrucktechnik auf das Substrat aufgebracht werden.
• Absatz 45. Sicherheitspapier für die Herstellung von Wertdokumenten oder dergleichen, das mit einem Durchsichtssicherheitselement nach wenigstens einem der Absätze 1 bis 25 oder mit einem nach wenigstens einem der Absätze 26 bis 44 hergestellten Durchsichtssicherheitselement ausgestattet ist.
• Absatz 46. Datenträger, insbesondere Wertdokument wie Banknote, Ausweiskarte oder dergleichen, der mit einem Durchsichtssicherheitselement nach wenigstens einem der Absätze 1 bis 25 oder mit einem nach wenigstens einem der Absätze 26 bis 44 hergestellten Durchsichtssicherheitselement ausgestattet ist.
• Absatz 47. Verwendung eines Durchsichtssicherheitselements nach wenigstens einem der Absätze 1 bis 44, eines Sicherheitspapiers nach Absatz 45 oder eines Datenträgers nach Absatz 46 zur Fälschungssicherung von Waren beliebiger Art.

Other features, aspects and embodiments are set forth in the following paragraphs.

• Paragraph 1. see-through security element for security papers, documents of value and the like having at least one microstructure with a viewing angle-dependent visual appearance, characterized in that the at least one microstructure is formed of an array of a plurality of structural elements having a characteristic pitch of 1 micron or more and that the see-through security element has a total thickness of 50 μm or less.
• Paragraph 2. see-through security element according to paragraph 1, characterized in that the see-through security element has a transparent or translucent substrate and a coating applied to the substrate marking layer containing the at least one microstructure.
• Paragraph 3. See-through security element according to paragraph 2, characterized in that the marking layer is a colored embossing lacquer layer is whose left standing in the embossed areas form the structural elements of the at least one microstructure.
• Paragraph 4. see-through security element according to paragraph 2, characterized in that the marking layer is a transparent or translucent embossing lacquer layer having embossed and subsequently filled with colored material recesses, which form the structural elements of the at least one microstructure.
• Paragraph 5. A see-through security element according to paragraph 2, characterized in that the marking layer is a printing layer with areas of high transparency and areas of low light transmittance, wherein the areas of low light transmission form the structural elements of the at least one microstructure.
• Paragraph 6. The see-through safety element according to paragraph 2, characterized in that the marking layer is a microtip printing layer with areas of high transparency and areas of low light transmission, wherein the areas of low light transmission form the structural elements of the at least one microstructure.
• Paragraph 7. see-through security element according to at least one of paragraphs 1 to 6, characterized in that the see-through security element has a total thickness of 20 microns or less, preferably from 3 .mu.m to 10 .mu.m.
• Paragraph 8. see-through security element according to at least one of paragraphs 1 to 7, characterized in that the structural elements have a characteristic structure spacing of 5 microns or more.
• Paragraph 9. See-through security element according to at least one of paragraphs 1 to 8, characterized in that the structural elements have a structure size of 1 micron or more, preferably of 3 microns or more.
• Paragraph 10. Transparent safety element according to at least one of Paragraphs 1 to 9, characterized in that the structural elements have a height-to-width ratio of about 1: 5 to about 5: 1, more preferably from about 1: 1 to about 5: 1, have.
• Paragraph 11. See-through security element according to at least one of paragraphs 1 to 10, characterized in that at least one microstructure is formed by a lamellar structure of a plurality of substantially parallel slats.
• Paragraph 12. see-through security element according to paragraph 11, characterized in that a plurality of microstructures formed by lamellar structures are provided, which differ in one or more of the parameters lateral orientation, color, width, height, relief shape and distance.
• Paragraph 13. See-through security element according to paragraph 12, characterized in that the differing lamellar structures are arranged in the form of patterns, characters or a coding.
• Paragraph 14. See-through security element according to at least one of paragraphs 1 to 13, characterized in that at least one microstructure in a marking layer is formed by a plurality of depressions with an increased light transmission.
• Paragraph 15. See-through security element according to paragraph 14, characterized in that the plurality of depressions are arranged in the form of patterns, characters or a coding.
• Paragraph 16. See-through security element according to at least one of paragraphs 1 to 15, characterized in that the structural elements are provided in partial areas with an opaque, transparent, semi-transparent, reflective or absorbent coating.
• Paragraph 17. See-through security element according to paragraph 16, characterized in that the coating is multi-layered, in particular three-layered, is formed.
• Paragraph 18. See-through security element according to paragraph 16 or 17, characterized in that the coating is designed as a thin-film element with a color shift effect.
• Paragraph 19. See-through security element according to at least one of paragraphs 1 to 18, characterized in that the structural elements are provided in partial areas with a metallic coating.
• Paragraph 20. See-through security element according to at least one of paragraphs 1 to 19, characterized in that the structural elements are provided in partial areas with a moth eye structure.
• Paragraph 21. See-through security element according to at least one of paragraphs 1 to 20, characterized in that the structural elements are provided in partial areas with a diffractive structure, which diffracts substantial parts of the incident light in directions outside the viewing direction.
• Paragraph 22. See-through security element according to at least one of paragraphs 16 to 21, characterized in that the structural elements have an asymmetrically arranged coating, moth-eye structure or diffractive structure.
• Paragraph 23. The see-through security element according to at least one of paragraphs 1 to 22, characterized in that the see-through security element has a transparent or translucent substrate having a first and an opposing second surface, wherein a transparent mask is applied to the first surface as a microstructure, and a congruent see-through mask with a predetermined lateral offset of 100 μm or less is applied to the second surface.
• Paragraph 24. A see-through security element according to paragraph 23, characterized in that the see-through mask contains a motif in the form of patterns, characters or a coding that is visually recognizable only at a certain viewing angle in view.
• Paragraph 25. See-through security element according to paragraph 23 or 24, characterized in that the see-through masks are each formed by an opaque layer with translucent openings having a size of less than 200 microns, preferably with a size of about 3 microns to about 100 microns, wherein the Openings form a motif in the form of patterns, characters or an encoding.
• Paragraph 26. A method of making a see-through security element according to any one of paragraphs 1 to 25, wherein the see-through security element is provided with at least one microstructure having a viewing angle dependent visual appearance comprising at least one microstructure of an array of a plurality of features having a characteristic feature spacing of 1 μm or more is formed and the see-through security element having a total thickness of 50 μm or less is produced.
• Paragraph 27. Method according to paragraph 26, characterized in that a marking layer is applied to a transparent or translucent substrate in which the at least one microstructure is formed.
• Paragraph 28. The method according to paragraph 27, characterized in that a colored embossing lacquer layer is applied as the marking layer and the embossing lacquer layer is structured by means of embossing techniques so that the areas left in the embossing form the structural elements of the at least one microstructure.
• Paragraph 29. Method according to paragraph 27, characterized in that a transparent or translucent embossing lacquer layer is applied as the marking layer, recesses are introduced into the embossing lacquer layer by embossing techniques and the introduced depressions are filled with colored material, so that the filled depressions are the structural elements of the at least one microstructure form.
• Paragraph 30. Procedure according to paragraph 27, characterized in that a printing layer with areas of high transparency and areas of low transparency is applied as the marking layer, the areas of low light transmission forming the structural elements of the at least one microstructure.
• Paragraph 31. Method according to paragraph 26 or 27, characterized in that the microstructure is applied to the substrate by
  1. a) a tool mold is provided whose surface has an arrangement of elevations and depressions in the form of the desired microstructure,
  2. b) the recesses of the mold are filled with a curable colored or colorless varnish,
  3. c) the substrate is pretreated for a good anchoring of the colored or colorless lacquer,
  4. d) the surface of the mold is brought into contact with the substrate,
  5. e) the lacquer standing in contact with the substrate is hardened in the depressions of the mold and thereby connected to the substrate, and
  6. f) the surface of the tool mold is removed again from the substrate, so that the hardened varnish bonded to the substrate is pulled out of the depressions of the tool mold.
• Paragraph 32. The method according to paragraph 31, characterized in that the recesses of the mold are filled in step b) with a radiation-curing lacquer and the lacquer in step e) is cured by exposure to radiation, in particular UV radiation.
• Paragraph 33. The method according to paragraph 31 or 32, characterized in that the varnish is pre-cured in the recesses of the tool mold prior to bringing the step d) into contact.
• Paragraph 34. Procedure under at least one of paragraphs 31 to 33, characterized in that the microstructure of the tool mold is formed by microstructure elements having a line width between about 1 μm and about 10 μm.
• Paragraph 35. The method according to at least one of paragraphs 31 to 34, characterized in that the microstructure of the mold is formed by microstructure elements having a texture depth of between about 1 μm and about 10 μm, preferably between about 1 μm and about 5 μm.
• Paragraph 36. The method according to at least one of paragraphs 26 to 35, characterized in that the see-through security element with a total thickness of 20 microns or less, preferably from 3 microns to 10 microns, is generated.
• Paragraph 37. A method according to at least one of paragraphs 26 to 36, characterized in that at least one microstructure is formed by a lamellar structure of a plurality of substantially parallel slats.
• Paragraph 38. A method according to at least one of paragraphs 26 to 37, characterized in that at least one microstructure in a marking layer is formed by a plurality of recesses with an increased light transmittance.
• Paragraph 39. The method according to at least one of paragraphs 26 to 38, characterized in that the structural elements are provided in partial areas with an opaque, transparent, semitransparent, reflective or absorbent coating, in particular with a metallic coating, a moth eye structure or a diffractive structure.
• Paragraph 40. The method according to paragraph 39, characterized in that the structural elements are provided with an asymmetric coating, moth-eye structure or diffractive structure.
• Paragraph 41. Procedure under at least one of paragraphs 26 to 40, characterized in that a transparent or translucent substrate having a first and an opposing second surface is provided, as a microstructure a see-through mask is applied to the first surface, and a congruent see-through mask with a predetermined lateral offset of 100 microns or less applied to the second surface becomes.
• Paragraph 42. The method of paragraph 41, characterized in that the see-through masks are applied simultaneously to the opposing surfaces of the substrate.
• Paragraph 43. The method of paragraph 41, characterized in that the see-through masks are successively applied to the opposing surfaces of the substrate.
• Paragraph 44. The method according to at least one of paragraphs 41 to 43, characterized in that the see-through masks are applied to the substrate by means of micro-gravure printing technology.
• Paragraph 45. Security paper for the production of documents of value or the like provided with a see-through security element according to at least one of paragraphs 1 to 25 or with a see-through security element manufactured according to at least one of paragraphs 26 to 44.
• Paragraph 46. Data carriers, in particular documents of value such as bank notes, identity cards or the like, which is equipped with a see-through security element according to at least one of paragraphs 1 to 25 or with a see-through security element produced according to at least one of paragraphs 26 to 44.
• Paragraph 47. Use of a see-through security element in accordance with at least one of paragraphs 1 to 44, a security paper pursuant to paragraph 45 or a data carrier in accordance with paragraph 46 for the purpose of securing the counterfeiting of goods of any kind.

Claims (15)

See-through security element for security papers, documents of value and the like having at least one microstructure with a viewing angle-dependent visual appearance, characterized in that the at least one microstructure is formed from an array of a plurality of structural elements having a characteristic pitch of 1 micron or more and the see-through security element Total thickness of 50 microns or less, and that the structural elements are provided in partial areas with an opaque, transparent, semi-transparent, reflective or absorbent coating, wherein - Several microstructures are formed by lamellar structures, which differ in one or more of the parameters lateral orientation, color, width, height, relief shape and distance; and or - The at least one microstructure is formed in a marking layer by a plurality of wells with an increased light transmittance. The see-through security element according to claim 1, characterized in that the see-through security element is a transparent or translucent substrate and, the marking layer is a marking layer applied to the substrate, which contains the at least one microstructure. See-through security element according to claim 2, characterized in that the marking layer is a colored embossing lacquer layer; or the marking layer is a micro-gravure printing layer having areas of high transparency and areas of low light transmission. See-through security element according to at least one of claims 1 to 3, characterized in that the lamellar structure is formed from a plurality of substantially parallel slats. See-through security element according to at least one of claims 1 to 4, characterized in that the differing lamellar structures and / or the plurality of depressions in the form of patterns, characters or a coding are arranged. See-through security element for security papers, documents of value and the like having at least one microstructure with a viewing angle-dependent visual appearance, characterized in that the at least one microstructure is formed from an array of a plurality of structural elements having a characteristic pitch of 1 micron or more and the see-through security element Total thickness of 50 microns or less, and that the structural elements are provided in partial areas with a moth eye structure. See-through security element for security papers, documents of value and the like having at least one microstructure with a viewing angle-dependent visual appearance, characterized in that the at least one microstructure is formed from an array of a plurality of structural elements having a characteristic pitch of 1 micron or more and the see-through security element Total thickness of 50 microns or less, and that the see-through security element is a transparent or translucent substrate having a first and an opposite second surface wherein, as a microstructure, a see-through mask is applied to the first surface, and a congruent see-through mask having a predetermined lateral offset of 100 μm or less is applied to the second surface and the see-through masks are each formed by an opaque layer having transparent apertures and the opaque ones Layers of the transparency masks are generated by metallization and demetalization. See-through security element according to claim 7, characterized in that the see-through mask contains a motif in the form of patterns, characters or a coding that is visually recognizable only at a certain viewing angle; and / or demetallization by lasers. See-through security element according to claim 7 or 8, characterized in that the translucent openings are formed with a size of less than 200 microns, preferably with a size of about 3 microns to about 100 microns, wherein the openings a motif in the form of patterns, characters or form an encoding. See-through security element according to at least one of claims 1 to 9, characterized in that the see-through security element has a total thickness of 20 microns or less, preferably from 3 microns to 10 microns; and / or the structural elements have a characteristic pitch of 5 μm or more; and / or the structural elements have a feature size of 1 μm or more, preferably 3 μm or more; and / or the structural elements have a height-to-width ratio of from about 1: 5 to about 5: 1, more preferably from about 1: 1 to about 5: 1. See-through security element according to at least one of claims 6 to 10, characterized in that the structural elements are provided in partial areas with an opaque, transparent, semi-transparent, reflective or absorbent coating. See-through security element according to at least one of claims 1 to 11, characterized in that the coating is multi-layered, in particular three-layered, and / or is formed as a thin-film element with a color-shift effect. See-through security element according to at least one of claims 1 to 12, characterized in that the structural elements are provided in partial areas with a metallic coating. See-through security element according to at least one of claims 1 to 13, characterized in that the structural elements are provided in partial areas with a diffractive structure, which diffracts substantial parts of the incident light in directions outside the viewing direction. See-through security element according to at least one of claims 1 to 14, characterized in that the structural elements have an asymmetrically arranged coating, moth-eye structure or diffractive structure.

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