WO2010046125A2

WO2010046125A2 - Security element having pressure-sensitive appearance

Info

Publication number: WO2010046125A2
Application number: PCT/EP2009/007607
Authority: WO
Inventors: Winfried HOFFMÜLLER; Manfred Heim; Michael Rahm
Original assignee: Giesecke & Devrient Gmbh
Priority date: 2008-10-24
Filing date: 2009-10-23
Publication date: 2010-04-29
Also published as: EP2349736B1; DE102008053099A1; WO2010046125A3; EP2349736B2; EP2349736A2

Abstract

A security element (2) for a data carrier comprises an elastically deformable, preferably compressible region and a functional structure that creates a visual impression with a user, wherein the elastically deformable region and the functional structure interact with each other such that in a non-deformed state of the elastically deformable region, a visual impression of the functional structure is obtained that differs from the visual impression in a deformed state of the elastically deformable region.

Description

Security element with pressure-sensitive appearance

The invention relates to a security element for a data carrier, the visual impression of which can be reversibly changed by mechanical pressure on the security element reversibly, a data carrier with such a security element, a transfer element with such a security element for application to a data carrier and a method for producing such security element.

Data carriers, such as securities or identity documents, or other valuables, such as branded articles, are provided with security elements for the purpose of security, which permit verification of the authenticity of the article and at the same time serve as protection against unauthorized reproduction. Furthermore, security elements often produce a highly visible visual impression, which is why such security elements are used in addition to their function as securing means sometimes even as decorative elements for such media or for their packaging. A security element can be embedded in such data carriers, for example in a banknote or in a chip card, or be designed as a self-supporting or non-self-supporting transfer element, for example as a non-self-supporting patch or as a self-supporting label, after its manufacture on a data carrier or other object to be secured , for example over a window area of the data carrier, is applied.

Data carriers in the context of the present invention are in particular banknotes, stocks, bonds, certificates, vouchers, checks, high-quality admission tickets, but also other papers forgery, such as passports or other identification documents, and also card-shaped data carriers, in particular chip cards, as well as product security elements, such as labels, seals . Packaging and the like. The term "data carrier" also includes non-executable precursors of such data carriers which, for example in the case of security paper, are in quasi-endless form and are processed further at a later time, for example into banknotes, checks, shares and the like.

To prevent counterfeiting or replication of security elements, for example with high-quality color photocopiers, security elements can have optically variable elements which convey different visual impressions to the viewer from different viewing angles. For producing functional or effect layers exhibiting such optically variable effects, various techniques are known. For example, optical interference layers can be present either over the entire surface or in pigment form. Such interference layers typically have a thin-film structure and comprise a reflection layer, an absorber layer and one or more intervening dielectric spacer layers and are based, for example, on mica, on SiO ₂ or on Al ₂ O ₃ . Printing inks with pigments of such single or multilayer interference thin layers are also available. Instead of interference layers or interference layer pigments can also cholesteric

Liquid crystals are used, which are present for example as liquid crystalline silicone polymers. Furthermore, holograms, which include metallic layers typically formed by vacuum deposition, or diffraction gratings, at different viewing angles, also exhibit a different visual impression to an observer.

The different optical impressions for a viewer can convey a so-called color-shift effect, in which different shades can be recognized by the observer at different viewing angles. Different visual impressions can also arise because, under a certain viewing angle, the effect layer is completely transparent and thus invisible to a viewer, while it shows a hue at a different viewing angle (effect angle).

Interference layers consisting of a single dielectric layer, inks with pigments of such interference layers or inks with liquid crystalline pigments are often highly translucent at all viewing angles, so that the color impression perceivable by the viewer when viewing the effect layer under the effect angle is relatively weak. Such effect layers with high light transmission are therefore preferably applied over dark or black backgrounds to improve the visibility of the color change. In contrast, multilayered interference layers and multilayered interface layer pigments show less translucency and are sometimes completely opaque.

US Pat. No. 5,712,731 A describes the use of a moire magnification arrangement as a security feature. This has a regular two-dimensional arrangement of identical printed microimages and a regular two-dimensional array of identical spherical microlenses. The microlens array has almost the same pitch as the microimage array. When the micro-image array is viewed through the microlens array, one or more enlarged versions of the microimages are created to the viewer in the areas where the two arrays are nearly in register.

The principal operation of such Moire magnification arrangements is described in the article "The Moire Magnifier", MC Hutley, R. Hunt, RF Stevens and P. Savander, Pure Appl. Opt. 3 (1994), pp. 133-142, described. In short, moirέ magnification thereafter refers to a phenomenon that occurs when viewing a raster of identical image objects through a lenticular of approximately the same pitch. As with any pair of similar rasters, this results in a moire pattern, which in this case appears as an enlarged and possibly rotated image of the repeated elements of the image raster. Further design variants and effects based on this mechanism are described, for example, in the article "Properties of moire magnifiers", Kamal et al., Optical Engineering 37 (11), pp. 3007-3014 (November 1998).

Regular microlens arrays can also be used as verification elements for security elements, as described in EP 1 147912 Bl. In this case, certain structures of a security element are only visible to the user when viewed through such a verification element, so that the function of the security element can be hidden for an unbiased viewer.

WO 2007/079851 A1 discloses an optically variable security element with an achromatically reflecting microstructure in the form of a mosaic. The mosaic shows a predetermined motif, which is composed of a number of pixels, wherein the pixels are each constructed from a plurality of achromatically reflecting micromirrors. The micromirrors are formed, for example, from metallized flanks of a sawtooth structure. In the simplest case, the flanks of the micromirrors of one pixel have the same angle of inclination, while the angles of inclination of the flanks of the different pixels differ. As a result, the pixels show different optical impressions among the observer at different viewing angles. From WO 2008/049533 A2 a see-through security element with a blind image is known. The venetian blind has raised, line-shaped, opaque areas, which have a characteristic size and a distance from each other that can not be resolved with the naked eye. When viewed vertically, the shutter image is therefore substantially transparent. On the other hand, if the observer tilts the blind image perpendicular to the line-shaped, opaque areas, these areas obstruct the view and the blind image appears opaque to the observer. The height-to-width ratio of the opaque regions is typically in the range of 2: 1. The space between the raised areas can also be filled with a translucent, ie semi-transparent, or even completely transparent lacquer. In an alternative embodiment, the raised areas are transparent and obliquely vapor-deposited with an opaque coating, resulting in an asymmetric, opaque coating of the resulting areas. Accordingly, at a given viewing angle, there is also an asymmetric view, which depends on the orientation of the blind image relative to the observer.

Furthermore, patent application EP 08004395 of the Applicant discloses photonic crystals which show a color change under mechanical pressure. Such photonic crystals often have the structure of internal opals. They typically have cavities which are produced, for example, by dissolving SiO 2 nanoparticles with dilute hydrofluoric acid. On the one hand, because of the necessary use of hydrofluoric acid, the production of such photonic crystals is complex; on the other hand, a significant period of time is required for the dissolution of the SiO 2 nanoparticles in the hydrofluoric acid, which precludes the rapid production of such photonic crystals and security elements with such photonic crystals. Furthermore, it is also known such photonic To embed crystals in the form of spherical nanoparticles in a compressible matrix.

The object of the present invention is to provide an easy-to-test security element, which can preferably be produced in a rapid process, that is, for example, can dispense with the use of the abovementioned photonic crystals.

This object is achieved by a security element, a data carrier, a transfer element and a production method having the features of the independent claims. The dependent claims relate to preferred embodiments and further developments of the invention.

The basic idea of the present invention is to provide an elastically deformable, in particular compressible region which can assume a deformed and an undeformed state and thus different spatial positions or preferably also different spatial expansions. It can be achieved by external mechanical pressure macroscopic rearrangements of the elastically deformable region or other with the elastically deformable region of mechanically connected elements of the security element. This results in a variety of ways to change the visual appearance and thus the visual impression in the viewer due to mechanical pressure. The change in the visual impression can be recognized by the viewer with the naked eye.

The security element according to the invention comprises an elastically deformable and optionally additionally compressible region and a functional structure which creates a visual impression on the viewer. The elas- The deformable region and the functional structure interact mechanically with one another in such a way that, in an undeformed state of the elastically deformable region, a visual impression of the functional structure results, which differs from the visual impression in a deformed state of the elastically deformable region.

The use of the elastically deformable region in conjunction with a functional structure which according to the invention produces an easily verifiable, variable visual impression ensures that such a security element can not be imitated by a simple copy, for example by a color copier. Such elastically deformable regions can only be produced with significantly higher outlay. In addition, the variable visual impression of the functional structure, which requires a well-defined mechanical interaction between the elastically deformable area and the functional structure, is not easily imitated by a counterfeiter, but easily verifiable by a user.

The mechanical interaction between the elastically deformable region and the functional structure for producing a variable visual impression can be realized in various ways. Likewise, the functional structure itself can be realized in various ways.

In the simplest case, the functional structure that creates the visual impression on the viewer may consist of one or more simple elements, such as a printed image. However, it can also have optically variable properties and then generates different visual impressions in the observer under different viewing angles. In this case, the functional structure includes, for example, an interference thin film, a Layer with interference thin-film pigments, a layer with liquid crystal pigments or diffraction structures, such as holograms. The functional structure may alternatively comprise a metallization.

In a first preferred embodiment of the invention, the spatial position of a part of the functional structure or the entire functional structure in the undeformed state of the elastically deformable region differs from the spatial position within the security element in the deformed state of the elastically deformable area. The functional structure is designed in such a way that the visual impression which the functional structure generates in the observer is changed by this change in position. Upon deformation of the elastically deformable region, the position of at least part of the functional structure within the security element is macroscopically changed for this purpose. The change in the spatial position may relate to the spatial position within the security element and / or the orientation of the at least part of the functional structure within the security element. In other words, in the latter case, an angle of the functional structure and thus also the viewing angle under which a viewer sees the at least one part of the functional structure changes. Thus, a security element is provided in which, due to the mechanical interaction between elastically deformable region and functional structure, the viewing angle under which the functional structure is viewed changes by the mechanical pressure on the security element, without the external perspective of the observer on the security element as a whole must change. If the functional structure in this case comprises an optically variable layer, then the corresponding optically variable effect can be observed, for example, in security elements which can not be tilted because of their attachment, without the viewer being forced to make the change necessary for this Observation angle must change its position relative to the security element.

In a first embodiment of the first embodiment, the elastically deformable region and the functional structure form a common region. The elastically deformable region thus contains the functional structure and is integrated in the elastically deformable region. Furthermore, the functional structure contains an optically variable element, with which a security element is created in which optically variable elements are introduced into an otherwise preferably translucent, elastically deformable region. The optically variable element of the functional structure therefore undergoes the same macroscopic positional change and / or change in orientation as the elastically deformable region upon deformation of the elastically deformable region.

In a second embodiment of the first embodiment, the functional structure is firmly connected to the surface of the elastically deformable region and also comprises an optically variable element. In the simplest case, the functional structure is arranged directly on the elastically deformable region. This can be done by flocking the elastically deformable region with, for example, uniform layer thickness with fibers which exhibit a color shift effect, for example due to cholesteric liquid crystal pigments or interference thin-film pigments contained therein. With mechanical pressure on the substrate, the viewing angle of the fibers changes, resulting in a color shift effect.

In a first variant of this second embodiment, a further intermediate layer is provided between the elastically deformable region and the functional structure, although of an inflexible, rigid material exists due to their structuring but still allows a spatial change in the position of the functional structure upon deformation of the elastically deformable region. For this purpose, the intermediate layer of a rigid, inflexible material, for example, as a broken layer, formed, whereby mechanically independent of each other and thus individually tiltable elements arise. The elastically deformable region can then advantageously be designed as a flat, compressible layer with a uniform layer thickness, which ensures a simple and cost-effective production of the elastically deformable region.

In a second variant of the second embodiment of the first embodiment of the invention, the functional structure is firmly connected to the surface of the elastically deformable, preferably compressible region, this region being structured and having a structure with spatially varying final layer thickness. As a result, the functional structure can be arranged on the elastically deformable region at a suitable angle, below which a variable optically variable impression, such as a color shift effect, already at a small deformation of the elastically deformable region and thus already upon exerting a low mechanical pressure on the security element can be perceived. For this purpose, the elastically deformable region may have a sawtooth or lamellar structure, wherein the functional structure is arranged on the flanks of the saw teeth or lamellae.

Such an elastically deformable region with spatially varying

Layer thickness can be produced by embossing. The underlying manufacturing process for the elastically deformable region comprises the steps: Providing a plastic layer, in particular an adhesive or embossing lacquer layer,

Embossing of the plastic layer by means of an embossing stamp to produce an embossed structure in the plastic layer, and

Adjusting the elasticity and preferably the compression behavior of the plastic layer, preferably by crosslinking, so that the embossed structure is elastically deformable and preferably compressible.

The order of these steps is arbitrary and depends on the desired result and the materials used.

The plastic layer used may, for example, consist of an adhesive, a resin or an embossing lacquer. The elastic parameters of the plastic layer are adjusted for example by crosslinking, so that an elastomer with suitable elasticity and optionally suitable compression behavior is formed. The crosslinking can occur, for example, via (UV) irradiation or the effect of temperature. However, the crosslinking can also take place automatically after a predetermined time, for example when using a two-component plastic.

The crosslinking can be done in a separate process step following the embossing of the plastic layer. The crosslinking can also take place in one process step together with the embossing, for example by embossing with elevated temperature. The crosslinking can also take place or be completed before the provision of the plastic layer, so that an elastomer with the desired elasticity already exists before embossing. and preferably compressible properties. The prerequisite is that such an elastomer can be permanently embossed to the desired extent.

By embossing thus an elastically deformable and optionally compressible layer can be created with spatially varying layer thickness, wherein there are many degrees of freedom for the specific design of the embossed structure.

Preferably, the elastically deformable bare embossed structure and also the die has a sawtooth structure, which is particularly preferably regularly. The functional structure, for example in the form of an optically variable layer, is then applied to the flanks of the saw teeth. With mechanical pressure, the saw teeth are reversibly folded, which changes the viewing angle and therefore creates a changed visual impression in the viewer without the entire security element, for example, has to be tilted or generally changed in its position.

Compared to the embossing of hard embossing lacquer, which are completely cross-linked, for example, when removing the die, further measures are necessary when embossing soft plastics and elastomers, which may not yet be cross-linked, since such soft plastic layers show, for example, increased adhesion to the stamper, so that it can not be deducted arbitrarily from the embossed structure. For example, the adhesion of the embossed structure to the embossing punch can be reduced by a suitable surface coating of the embossing punch, for example in the form of a suitable release layer. It is also possible to transfer a coating from the die to the surface of the embossing pattern simultaneously with embossing. For this purpose, the adhesion of the coating to the embossing stamp is preferably lower than the adhesion of the coating to the surface to be provided with the embossed structure. After embossing and removal of the embossing stamp, the coating can optionally be removed again from the embossed structure. In an advantageous embodiment of the invention, however, the coating remains on the embossed structure and forms at least a part of the functional structure, for example, exclusively on the flanks of the sawtooth embossed structure and not on the vertical edges of the

Sawtooth structure is arranged. The coating transferred from the die to the embossed surface is preferably a metallization. However, other layers of a functional structure can also be transferred, such as, for example, the dielectric layer of an interference thin film or a layer with interference thin-film pigments or liquid-crystal pigments.

Upon deformation, the saw teeth of the sawtooth structure of the elastically deformable region in their foot region generally show a lower tilt than at the tips of the saw teeth. Since the largest possible proportion of the optically variable layer of the functional structure is to be influenced by mechanical pressure and the area in which the optically variable effect can not be influenced by mechanical pressure should be as small as possible, it is advantageous if the foot region of the saw teeth is not optically shows variable effect. For this purpose, the functional structure in the foot region of the saw teeth, for example, recesses. In the case of an interference thin film, it is sufficient if only one of the layers forming the interference layer has recesses in the foot region, so that the remaining coatings in this region have no interference. more thin film with interference effect. Alternatively, the functional structure may be covered in the foot region of the saw teeth.

The aforementioned recesses are produced in a first production variant by oblique vapor deposition of the embossed structure. The vapor deposition takes place in the direction of the flanks of the sawtooth structure of the embossed structure, so that the tips of the saw teeth shade the foot region of the flank of the respective adjacent sawtooth. The vertical edges of the sawtooth structure are also not coated in such oblique vapor deposition. In this case, a metallization or an optically variable layer can be vapor-deposited.

In a second production variant of the production of the recesses in the foot region of the sawtooth structure, a low-viscosity wash ink is first applied to the embossed structure before the application of a coating to the embossed structure. The wash color flows into the deepest places and thus covers only the foot areas of the edges of the saw teeth. Advantageously, the low-viscosity wash ink dews the tips of the sawtooth structure, which can be achieved by a suitable surface tension of the wash dye relative to the embossed structure. Subsequently, the desired coating is applied over the entire surface of the embossed structure and the wash color. The washing ink preferably has a highly porous surface which is not completely covered by the applied coating, as a result of which the washing ink, in spite of the applied coating, can be washed out in a further process step, so that the desired recesses are formed in the root area of the sawtooth structure. In a third production variant, the desired coating is applied over the entire surface of the sawtooth structure of the embossed structure. Subsequently, a low-viscosity topcoat is applied to the coated embossed structure, so that the foot portions of the flanks of the sawtooth structure of the embossed structure are covered and thus no longer produce an optically variable effect.

In a fourth production variant, the generation of the recesses in the foot region of the embossed structure is combined with the previously mentioned transfer of a coating when embossing the embossed structure.

In a first embodiment of the fourth production variant, the desired coating to be transferred is applied over the entire surface of the embossing punch. Subsequently, the coating in the region of the tips of the sawtooth structure of the stamping die is removed again. After that, a

Adhesive layer over the entire surface of the die or applied to the stamp applied to the coating and then the plastic layer, which forms the elastically deformable region in the finished process product, embossed with the thus prepared die, so that the desired embossing structure is formed while the adhesive layer with the partially existing coating is transferred. Since the coating has been removed at the tips of the sawtooth structure of the embossing die prior to the embossing step, after the transfer of the coating in the foot region of the sawtooth structure of the embossed structure as desired, there is no coating. Removal of the coating from the dies of the die can be accomplished by mechanical scrubbing on the tips. It is advantageous if the applied coating is a slightly cleavable coating. In a second embodiment of the fourth production variant, in turn, the desired coating is first applied to the embossing stamp over the full area. Subsequently, a low-viscosity adhesive is applied to the sawtooth structure of the embossing die, so that it collects in the foot areas of the sawtooth structure of the embossing die before the embossed structure is embossed. When removing the embossing die, the coating then remains on the embossed structure only at the locations where an adhesive layer has previously been applied. In other words, an embossed structure is thus produced which only shows a coating at the tips and has the desired recesses in the foot regions. It is advantageous if, without the adhesive layer, the adhesion of the coating to the embossing punch is greater than the adhesion of the coating to the embossed structure, so that when the embossing stamp is removed from the embossed structure, the coating in the foot region of the sawtooth structure of the embossed structure is removed again.

Preferably, the die is made of a hard embossing lacquer, since in this case the desired adhesive strengths of the various coatings and adhesive layers can be easily matched.

In a further advantageous embodiment of the production method, the plastic layer to be embossed is constructed in two layers and comprises an upper and a lower layer, wherein the lower layer can be removed in a targeted manner after embossing. If a sawtooth structure is embossed in a central region of such a two-layered substrate, then the upper layer will lie on the surface of the flanks of the saw teeth, while the lower layer will lie beneath these flanks and in the simplest case will be exposed at the vertical edges of the sawtooth structure. In a further method step, the lower layer is then removed, so that only the upper layer, which had previously formed the edges of the saw teeth, remains as a lamellar structure. This lamellar structure forms the elastically deformable region of the security element, which can be designed to be incompressible. In contrast to a sawtooth structure, such lamellae have the advantage that the lamellae can be elastically deformed, in particular fully folded, even at a lower mechanical pressure, so that they lie, for example, parallel to the surface of the security element.

Generally has the security element, in particular its elastically deformable region, a sawtooth or lamellar structure, as described for example in the second variant of the second embodiment of the first embodiment of the invention, it may be advantageous if the tips of the saw teeth or fins are mechanically connected to each other to distribute a force exerted on the security element evenly on the individual sawteeth or lamellae mechanical pressure. The saw teeth or lamellae then show a uniform elastic deformation and optionally compression, resulting in a uniform change of the visual impression upon deformation of the elastically deformable region. This mechanical bonding is preferably done by laminating a, for example, inflexible translucent film on the tips of the saw teeth or lamellae, wherein the translucent film, for example, has a thin laminating adhesive layer.

In the simplest case, in the various variants and configurations of the first embodiment of the invention, the functional structure lies in the viewing direction in front of the elastically deformable region, so that the optical properties of the elastically deformable region are meaningless. tion are. The elastically deformable bare area can therefore be opaque, for example.

In a second preferred embodiment of the invention, the light path or the beam path within the security element in the undeformed state of the elastically deformable region differs from the light path in the deformed state of the elastically deformable region. Here, too, the spatial position of a part of the functional structure in the undeformed state of the elastically deformable region differs from the spatial position in the deformed state of the elastically deformable region.

In a first preferred embodiment of the second embodiment, the functional structure for this purpose comprises a first and a second element. The second element is arranged in the viewing direction in front of the first element and translucent. The elastically deformable region forms a spacer for the first and second elements of the functional structure, and in the undeformed state of the elastically deformable region, the first and the second element of the functional structure are spaced apart so that, for example, a gap results, while in the deformed state of the elastically deformable region, the first and the second element of the functional structure are spatially in contact with one another. In the simplest case, the spacer is made compressible. However, due to its elastic properties alone, it can provide the necessary spatial relative movement of the first and second elements of the functional structure.

In a first variant of the first embodiment of the second embodiment, the second element on the back, ie on the first ment opposite surface totally reflecting, especially retro-reflective. In the undeformed state of the elastically deformable region, ie, when the first and the second element are spaced from each other, it is not possible to see through the first element of the functional structure lying behind the second element in the viewing direction. The first element is therefore not visible in this state of the security element. In spatial contact of the first and second element takes place at the rear of the second element instead of a transition to air, which is located in the gap between the first and second element, now a transition to the material of the first element of the functional structure. Since this material has a refractive index different from one, the refractive conditions on the back side of the second element of the functional structure change such that the condition of total reflection or retro reflection is canceled. Thus, the light path or the beam path changes within the functional structure of the security element, and the first element of the functional structure becomes visible and can be viewed.

In a second variant of the first embodiment, the second element on the back and the first element on the front carry a reflective or partially reflective coating. Thus, interference effects, as they are known, for example, in the form of Newton's rings are deliberately amplified and used as a visual effect. The shape of such Newtonian rings generally depends on the distance or spatial variation of the distance from the first and second elements of the functional structure. The distance that occurs at a given mechanical pressure, for example, can be adjusted by suitable spacers. In a third variant, a dielectric layer having a constant layer thickness is located on the rear side of the second element of the functional structure in addition to a partially reflecting layer, while a completely reflecting layer is located on the opposite front side of the first element of the functional structure. This results in contact of the first and second element by combining the different layers of an interference thin film, while they represent no more interference thin film when spaced and produce a significantly different visual impression.

In a second preferred embodiment of the second embodiment of the invention, the elastically deformable region and the functional structure are each formed in a layered manner. Furthermore, the elastically deformable region is translucent and arranged in the viewing direction in front of the functional structure. In the simplest case, the translucent elastically deformable region replaces the translucent first element of the functional structure of the previously described first embodiment of the second embodiment of the invention and thus forms part of the functional structure.

In a first variant of the second embodiment, the translucent, elastically deformable region on the reverse side of the functional structure is designed to be totally reflective, in particular retro-reflective. By deformation of the elastically deformable region while the condition of total reflection or the retro-reflection is canceled on the back of the elastically deformable region, which abruptly a review of the underlying layer-like functional structure is possible. The functional structure is composed in the simplest case of a printed image or of metallized and demetallisierten areas. The functional structure is particularly preferably an optically variable layer showing, for example, a color shift effect. Likewise, the functional structure in the form of a raster image can be structured in a location-dependent manner; for example, the absorber layer and the dielectric layer can be removed in regions. In addition, the reflective layer can be removed in areas. Alternatively, the functional structure may also include a diffraction grating, preferably in combination with a metallization and / or a high refractive index layer.

Of course, instead of retro-reflection, any other possibility can be used in which angle-dependent reflection makes the view of the underlying functional structure possible or not dependent on the angle.

In a second variant of the second embodiment of the second embodiment of the invention, the security element comprises a moire magnification arrangement. In this case, the functional structure forms the microimage arrangement of such a moiré magnification arrangement, while the elastically deformable region is arranged as a translucent intermediate layer between the microlens arrangement of the moiré magnification arrangement and the functional structure. The elastically deformable region is formed here as a flat, compressible layer with a substantially constant layer thickness. By mechanical pressure of the elastically deformable region can be compressed, whereby the distance between the microlens array and the microimage array is changed. Thus, the focusing condition within the moiré magnification arrangement is changed by mechanical pressure.

In a third variant of the second embodiment of the second embodiment of the invention, the elastically deformable region has a spatially varying layer thickness, and the functional structure comprises an optically variable layer. The elastically deformable region has oblique flanks, for example, with respect to the surface of the security element, whereby the optical path is refracted when viewed perpendicularly and the optically variable layer lying behind the elastically deformable region is viewed at an observation angle which is already evident in the undeformed state of the elastically deformable region deviates from the actual angle at which the security element is viewed. For example, when the security element is viewed vertically, the viewing angle to the optically variable layer can deviate significantly from the surface normal of the preferably planar, optically variable layer. The elastically deformable region can again be in the form of a sawtooth structure and, as already discussed above, can be produced by embossing. In contrast to the first embodiment of the invention described above, the elastically deformable region in this embodiment of the second embodiment is translucent, and instead of a change in the spatial position of the functional structure of the perspective on the lying in the viewing direction behind the elastically deformable region functional structure on the one hand spatially varying layer thickness and on the other by mechanical pressure on the elastically deformable region, such as a sawtooth structure changed. In order to ensure a uniform deformation of the individual saw teeth, in turn, as in connection with the first embodiment, in turn, the tips of the saw teeth are mechanically connected.

In addition to the functional structure lying behind the elastically deformable region in the viewing direction, for example, the flanks of the sawtooth structure of the elastically deformable region can be connected to another Coating, preferably a metallization, be provided to produce, for example, a blind effect. Furthermore, it is also possible to create a combination of the tiltable achromatic micromirrors known from WO 2007/079851 A1 and the louvre effect known from WO 2008/049533, since the functional structure arranged behind the elastically deformable region, which shows a color tilting effect, for example the metallized, mirrored flank of the sawtooth structure of the elastically deformable region is visible only when viewed obliquely by the uncoated, vertical edges of the sawtooth structure of the elastically deformable region. Preferably, the metallization on the flanks of the sawtooth structure in the foot of the saw teeth on recesses, which can be achieved for example by oblique vapor deposition or metallization. In the case of oblique evaporation, an opacifier thus also results in the area of the vapor deposition angle, thus, in conjunction with the sawtooth structures, a louver effect. The angle range from which the element appears opaque can thus be set via the evaporation angle.

In a fourth variant of the second embodiment of the second embodiment of the invention, the elastically deformable region is formed as a planar layer with a substantially spatially uniform layer thickness. In the viewing direction in front of the elastically deformable region, a further translucent layer of a translucent material is arranged, which is mechanically connected to the elastically deformable region and comprises a plurality of elements, which are preferably individually tiltable.

In a third preferred embodiment of the second embodiment of the invention, microlenses with a coating with uniform ger layer thickness, in particular generated with an interference thin film. In general, coating of an uneven surface by vapor deposition can not produce uniform layer thicknesses, since the layer thickness depends on the orientation of the surface relative to the vapor deposition direction. Therefore, for example, on microlens arrays, no interference thin films having a uniform color shift effect can be provided yet, because in such interference thin films, the color shift effect depends on the film thickness of the dielectric film. In this preferred embodiment, vertical cylinders are arranged on a translucent, planar layer at the locations where a microlens is to be formed. Subsequently, a reflective layer, a dielectric layer and a partially reflecting layer are vapor-deposited by vertical vapor deposition, so that an interference thin layer having a uniform layer thickness of the various layers, in particular the dielectric layer, is formed on the flat surface and on the end faces of the cylinder. Subsequently, the planar layer and the cylinders are for example heated or otherwise suitably treated, so that it comes to a running of, for example, thermoplastic material from which the flat layer and the cylinders are made. As a result, the cylinders and the planar structure connect and form microlenses at the locations of the cylinders below the interference thin-film. The material of which the planar layer and the cylinders are made may further be elastically deformable and then form an elastically deformable region in the security element. Thus, a security element is provided with an elastically deformable region with microlenses, which carry an optically variable coating, preferably in the form of an interference thin film as a functional structure. The lenses included can either be reversibly deformed directly by pressure or transferred into an elastomer including the interference thin film. During the course of the Cylinder to the microlenses and even when deforming the microlenses, the applied interference thin film may possibly break, but this is irrelevant to the color impression.

In the case of mechanical deformation, the elastically deformable region preferably exhibits temporal hysteresis such that, after a mechanical pressure has been exerted, it initially remains in the deformed state for a predetermined period of time. Thereby, the visual impression of the functional structure in the deformed state of the elastically deformable region can be considered without the security element being covered by elements which exert the mechanical pressure, for example the finger of the observer. If the security element has areas which on the one hand are spaced apart from one another in the deformed and undeformed state of the elastically deformable region and on the other hand are in mechanical contact with one another, as described, for example, in the first embodiment of the second embodiment of the invention, at least one of these contact surfaces can also be used be provided with a suitable (translucent) adhesive layer, which ensures a temporally limited adherence of the two areas and a subsequent trouble-free detachment of both areas from each other. Such layers can be created, for example, by radiation-crosslinkable silicones.

Further exemplary embodiments and advantages of the invention are explained below by way of example with reference to the accompanying figures. The examples represent preferred embodiments which in no way limit the invention. The figures shown are schematic representations that do not reflect the real proportions, but serve an improved clarity of the various embodiments. In detail, the figures show:

1 shows a banknote with a security feature;

Fig. 2a - 2d four embodiments with a sawtooth structure;

3 shows an exemplary embodiment with a lamellar structure;

4 shows an exemplary embodiment with mechanically connected sawtooth tips;

5 shows an embodiment with Colorshif t fibers.

6 shows an embodiment with a variable blinds effect;

7 shows a totally reflective security element;

FIG. 8 shows a retro-reflective security element as a special embodiment of a total-reflecting security element from FIG. 7; FIG.

9 shows a security element with an interference

thin film;

10a-10d different embodiments of a Moire

Magnification arrangement with an elastically deformable intermediate layer; 11-13b show three exemplary embodiments of production methods for producing a coating of a sawtooth structure with recesses in the foot region;

FIGS. 14a-15 show two embodiments of production methods for producing a coating of a sawtooth structure with recesses in the foot region during embossing; and

16a, 16b show a manufacturing method for elastically deformable

Microlenses.

In Fig. 1 as a data carrier, a banknote 1 is shown. It comprises a security element 2, in which the line-shaped points of a sawtooth structure are shown schematically.

FIG. 2 a shows a side view of a security element 2 with a sawtooth structure. A compressible, elastically deformable region 4 in the form of a layer with saw teeth 5 and thus with a spatially varying layer thickness is arranged on a carrier substrate 1a. On the flanks of the saw teeth, a coating 3 is arranged, which forms a functional structure. The coating 3 is in the simplest case a metallization or also an optically variable layer. With mechanical pressure on the saw teeth 5, these are compressed, as a result of which their flank angle changes. The consideration is in Fig. 2a from above. As a result of the deformation of the saw teeth, the angle at which the coating 3 is viewed, and thus the visual impression of the security element, changes as the whole of the security element 2 as a whole remains the same. The flank angle of the saw teeth 5 is selected so that upon deformation the perceptibility of the changing visual impression of the coating 3 is supported. If the coating 3 is, for example, an optically variable layer which exhibits a color-shift effect, then it is arranged within the security element 2 in such a way that, when the security element 2 is viewed vertically, the color-shift effect already occurs with slight deformation of the elastically deformable region 4.

If the coating 3 breaks because of the deformation of the saw teeth 5 of the elastically deformable region 4, this plays only a minor role for the visual impression, since the typical size of such a crack is below the resolution of the eye and the mechanical deformation elastic Thus, it is reversible, so that after completion of the mechanical pressure of the elastically deformable region 4 assumes its original position and the cracks that may occur are thus closed.

FIG. 2 b shows a variant of the security element 2 shown in FIG. 1. The saw teeth 2 are made of a rigid, inflexible material and are arranged on an elastically deformable, compressible region 4 in the form of a flat layer with a uniform layer thickness. The saw teeth 5 are not mechanically connected to each other, which is indicated by the broken lines 6. As a result, the rigid sawing teeth 5 can be tilted individually on the elastically deformable layer 4 and partially submerged in them. The flanks of the saw teeth 5 in turn carry the desired coating 3. The elastically deformable bare area 4 is in this embodiment as a flat, compressible layer with the same formed layer thickness, which can be created easily and inexpensively.

Such mechanically unconnected rigid saw teeth 5 can form a broken layer, which can be obtained by deliberately tearing a hard lacquer, for example by pulling the carrier substrate over an edge or by stretching, pressing or temperature loading the carrier foil. In this case, the foot regions of the saw teeth 5 represent preferred areas for such a crack because of the layer thickness which is only slight or zero there. The cracks or fractures can be induced before or after the hard layer is brought into contact with the flexible layer.

To produce such a security element 2, such a sawtooth structure is produced from a hard lacquer on a carrier foil, for example. The sawtooth structure is laminated with a laminating adhesive whose elasticity can be suitably adjusted, for example by crosslinking, so that the laminating adhesive forms the desired, elastically deformable region 4. Subsequently, the carrier film is peeled off in a separating winding process and, at the same time or at a later time, the sawtooth structure of the inflexible, rigid lacquer is broken, whereby individual saw teeth 5 are formed on the elastically deformable region 4.

In Fig. 2c, a further variant of the embodiment shown in Fig. 2a is shown. In this case, the compressible, elastically deformable region 4 again lies in the form of a layer with saw teeth 5. However, the functional structure lies here as a planar layer 7 in the viewing direction behind the elastically deformable region 4. The saw teeth 5 of the elastically deformable region 4. Baren area 4 are therefore formed translucent. The functional structure is viewed through the oblique edges of the saw teeth 5, whereby the light path is refracted and the angle at which the functional structure 7 is viewed differs significantly from the viewpoint of the observer on the security element 2.

By mechanical pressure on the saw teeth 5, in turn, their flank angle changes, thereby additionally changing the angle at which the functional structure 7 is seen changes. The flank angle of the saw teeth 5 is set so that a variable visual impression, such as a color shift effect, even at a low deformation of the saw teeth 5 occurs.

In Fig. 2d a variant of the embodiment shown in Fig. 2b is shown. In this case, as in the exemplary embodiment shown in FIG. 2c, the functional structure is provided as a planar layer 7 instead of a coating 3, which lies behind the sawteeth 5 of rigid, inflexible material and the elastically deformable region 4 in the viewing direction. In this case, the saw teeth 5 and the elastically deformable region 4 are translucent in order to permit a consideration of the functional structure, primarily by the oblique flanks of the saw teeth 5. With mechanical pressure on the saw teeth 5, these tilt and dive partially into the elastically deformable region 4, whereby the angle at which the functional structure is seen changes. FIG. 3 shows a further variant of the exemplary embodiment shown in FIG. 2a. In this case, the elastically deformable region is in the form of lamellae 9. In this case, the lamellae 9 can themselves form the functional structure or have a functional structure in the form of the coating 3. Such lamellae 9 can be produced, for example, by embossing a sawtooth structure into a two-layer embossed structure. In this case, a layer Ib and thereon an intermediate layer is applied to the carrier substrate 1a, the material of the layer 1b having less or no solubility with respect to a solvent provided than the intermediate layer. Subsequently, the sawtooth structure is embossed into the two layers, the layer 1b and the intermediate layer, the intermediate layer being completely and the layer 1b still being partially structured. Subsequently, the elastically deformable region 4 and, if the elastically deformable region 4 does not already form the functional layer, the coating 3 is applied, which are each with respect to the intermediate layer with the proposed solvent almost insoluble. In the following step, the soluble intermediate layer is removed with the intended solvent, so that the lamellae 9 remain and are anchored in the layer Ib. Alternatively, the material of the intermediate layer can also be chosen such that the intermediate layer can be removed in another way, for example by thermal melting, evaporation or blowing off.

The lamellae 9 form the elastically deformable region 4, which has a suitable mechanical elasticity and can be incompressible. The lamellae 9 can be provided with a further thin, flexible layer for protection against mechanical breakage.

4, an embodiment of a security element 2 is shown with a sawtooth structure. The tips of the saw teeth 5 are mechanically connected by an at least partially rigid layer 8. The layer 8 is designed so rigid that they at least in the corresponding area a uniform distribution of the mechanical pressure the saw teeth 5 guaranteed. Form the saw teeth 5, as in the embodiment shown in Fig. 2a, the elastically deformable region 4, the layer 8 ensures a uniform deformation and compression of the saw teeth 5. In contrast, form the saw teeth 5, as shown in Fig. 2b Embodiment, individually tiltable elements of a rigid material, the layer 8 ensures their region-wise uniform tilting. Likewise, the tips of the blades 9 shown in FIG. 3 can be mechanically connected by such a layer 8, which ensures a uniform deformation of the blades 9. The layer 8 thus ensures an at least area wise uniform change of the visual impression of the functional structure upon exertion of mechanical pressure on the security element 2. The layer 8 is translucent. It is created, for example, by laminating an inflexible translucent foil on the tips of the saw teeth 5 or lamellae 9, the translucent foil having, for example, a thin laminating adhesive layer. For the purposes of this invention, the layer 8 is thus to be described as rigid if it distributes a local mechanical pressure on its surface over a large area to a specific region of the saw teeth 5. For example, even the rigidity of a conventional PET film may be sufficient to meet this condition.

In the case of lamellae 9, the rigid layer 8 additionally provides protection for the individual lamellae 9 against mechanical breakage.

The embodiment shown in FIG. 5 shows a functional structure that is encompassed by the elastically deformable region 4. The functional structure is thus part of the elastically deformable region 4. The functional structure comprises optically variable elements in the form of liquid crystal or interference thin-film pigments. The elastically deformable region is in the form of fibers 10, which then show a color shift effect. Such fibers 10 are also referred to as color shift fibers. With mechanical pressure on such Colorshift fibers 10, the spatial position of the fibers 10 within the security element 2 and thus the viewing angle, under which the viewer sees the optically variable elements contained in the Colorshift fibers 10, which changes for a viewer with mechanical pressure on such a security element 2 gives a changed visual impression. Such color shift fibers 10 are preferably non-compressible. Preferably, a plurality of such Colorshift fibers 10 are then arranged side by side in the security element, for example in the manner of a velvet fabric. This results in an area of the security element that produces a uniform visual impression under mechanical pressure. If the optically variable elements have only a low color strength, as is the case, for example, with liquid crystal or interference thin-film pigments, then a dark background can be provided for the Colorshift fibers 10 by creating the substrate Ia in dark or black color or is covered.

Alternatively, the elastically deformable region 4 comprising the functional structure is not provided in the form of fibers 10, but in the form of lamellae 9, as shown in FIG. 3, or in the form of sawteeth 5, as shown in FIG. 2a , In this case, the coating 3 shown in FIGS. 2a and 3 can then be omitted in each case.

In the exemplary embodiment shown in FIG. 6, an interference thin film 11 is arranged on a carrier substrate 1a. This consists of a partially reflecting layer 11.1 (absorber) of Cr, of a dielectric layer 11.2 of SiO 2 and of a reflective layer 11.3 (reflector) of Al. Depending on the viewing angle, this interference thin-film 11 produces a different color impression in the viewer and in particular a color-shift effect. On this interference thin film 11, an elastically deformable, compressible region 4 in the form of a structure with saw teeth 5 is arranged. On the flanks of the saw teeth 5, a metallic coating 3 is vapor-deposited. The metallic coating 3 can be applied by oblique vapor deposition, so that recesses 12 in the metallic coating are created in the foot region of the saw teeth 5. The metallic coating 3 is made of Al. By the metallic coating 3 of the edges of the saw teeth 5 achromatic micromirrors are created whose alignment can be changed by mechanical pressure on the saw teeth 5. Furthermore, the metallic coating 3 prevents the interference thin film 11 from being observed through the flanks of the saw teeth 5. On the other hand, the vertical edges 13 are not coated and allow viewing of the interference thin film 11 in a limited angular range. By compression of the saw teeth 5, the area of the vertical edges 13 and thus the angle range under which the interference thin-film 11 can be viewed changes or decreases. Thereby, a louver effect is generated which allows the interference thin film 11 to be viewed in the undeformed state of the saw teeth 5 of the elastically deformable portion 4 in a different form from that in the deformed state. In the deformed state of the saw teeth 5, the security element appears as a substantially continuous metallized surface. Since the flank angle of the saw teeth changes only slightly in the foot region under mechanical pressure because of the low layer height of the elastically deformable region 4, recesses 12 are provided in this region. The elastically deformable layer 4 is translucent in this embodiment. A non-illustrated variant of this embodiment is a further development of the known from WO 2006/049533 Venetian blind. Here, the disclosed there, raised, opaque or coated areas and optionally also the intervening transparent areas of an elastically deformable material are generated. This visually different impressions can be generated not only by tilting the security element, but also by mechanical pressure, preferably in the form of a shear force.

In the exemplary embodiment illustrated in FIG. 7, an interference thin film 11 is again arranged on a carrier substrate 1a. Above this there is a translucent, rigid embossing lacquer layer 15. Above this there is a translucent, compressible, elastically deformable region 4. Embossing lacquer layer 15 and elastically deformable layer 4 each have spatially varying layer thicknesses. In the undeformed state of the elastically deformable region 4, the embossing lacquer layer 15 and the elastically deformable layer 4 are spaced apart from each other and have an intermediate cavity 16 in the form of a gap. Embossing lacquer layer 15 and elastically deformable region 4 have a corresponding sawtooth structure on the surfaces lying opposite one another. The elastically deformable layer 4 is formed so that the edges of the sawtooth structure total reflection results in the figure from above coming light beams. This can be achieved by a sufficiently high refractive index, by a suitable backside interface coating, and / or by a suitable choice of the ramp angle of the saw teeth. The elastically deformable region 4 extends laterally beyond the embossing lacquer layer 15 and forms spacers at these locations in order to create the cavity 16 in the undeformed state. In the deformed state of the elastically deformable region 4, they engage opposing surfaces of embossing lacquer layer 15 and elastically deformable portion 4 into each other, so that the cavity 16 disappears. As a result, the optical conditions at the rear interface of the elastically deformable region 4 change, thereby canceling the condition of total reflection. Thus, upon deformation of the elastically deformable region, viewing of the underlying interference thin film 11 is possible.

The contact surface between the elastically deformable region 4 and embossing varnish layer 15, that is to say the back side of the elastically deformable region 4 and the front side of the embossing lacquer layer 15, thus have mutually corresponding surfaces which ensure good mechanical contact. In this case, the mechanical, spatial contact between the elastically deformable region 4 and embossing lacquer layer 15 can be promoted by a further, not shown, thin, soft, translucent layer on the back of the elastically deformable region 4 and / or on the front side of the embossing lacquer layer 15. In the simplest case, both surfaces can be even.

In order to provide the largest possible area in which the visual impression differs in the deformed and undeformed state of the elastically deformable region, the contact surface comprises the entire opposing surfaces of elastically deformable region 4 and embossing lacquer layer 15. The elastically deformable region 4 and the embossing lacquer layer 15 can thus each be constructed as a film whose distance can be reversibly changed.

FIG. 8 shows an exemplary embodiment in which, in turn, an interference thin-film 11 is located on a carrier substrate 1a. On the Interference thin film 11 is formed a compressible, elastically deformable region 4, which is constructed of two superposed, directly adjoining, translucent, compressible, elastically deformable layers 4a and 4b. The two translucent, elastically deformable layers 4a and 4b have a serrated boundary surface 14 at right angles. The two elastically deformable, translucent layers 4a and 4b differ in their refractive indices and / or have a suitable coating on the interface 9, so that in the undeformed state of the elastically deformable layer 4 at the interface 14 the condition for retro Reflection is fulfilled in the figure from above coming light beams. Alternatively, the layer 4b may be formed of air trapped between the layers 4a and 11 so as to give a large difference in optical refractive index to the layer 4a. With mechanical pressure on the elastically deformable layer 4, the shape of the interface 14 changes, so that in the deformed state, the condition of the retro-reflection is no longer satisfied. By mechanical pressure on the security element, the review of the underlying interference thin film 11 is possible.

In the exemplary embodiment illustrated in FIG. 9, an elastically deformable region 4 in the form of a planar layer with spacers 4c is provided on a carrier substrate 1a. The planar layer of the elastically deformable region 4 is coated with a reflective layer 11.3. Spaced apart by a cavity 16, there is a dielectric layer 11.2 above it and a partially reflecting layer 11.1. Above is a rigid, translucent layer 17. If the partially reflecting layer 11.1 and the dielectric layer 11.2 above the cavity 16 are spaced from the reflective layer 11.3, the result for a viewer who looks in the figure from above at the embodiment, a visual input pressure, which is essentially determined by the metallic, reflective layer 11.3. If, on the other hand, the partially reflective layer 11.1, the dielectric layer 11.2 and the reflective layer 11.3 lie directly against one another, they form an interference thin layer 11, and the visual impression changes markedly. In addition, this interference thin film 11 exhibits a color shift effect, so that the visual impression changes at different viewing angles. The spacing of the partially reflecting layer 11.1 and the dielectric layer 11.2 from the reflective layer 11.3 is set by means of spacers 4c, which are likewise elastically deformable. On the upper side of the spacers 4c, in turn, a reflective layer 11.3 and additionally an adhesive layer 18 are provided. The adhesive layer 18 also acts as a dielectric layer, which is why an interference thin film is formed on the upper side even in the undefined state of the spacers 4c. The spacers 4c are arranged in the form of graphic motifs, symbols or characters, so that a corresponding information results for a viewer in plan view. Thus, in the undeformed state of the elastically deformable spacers 4c, this information appears as an optically variable layer against a metallic background created by the reflective layer 11.3 on the planar layer of the elastically deformable region 4 outside of the spacers 4c. With mechanical pressure on the rigid, translucent layer 12, the spacers 4c are compressed so that the entire surface of the security element 2 is an optically variable layer. However, due to the adhesive layer 18 applied to the upper side of the spacers 4c, a different layer thickness of the dielectric layer results in the regions of the spacers 4c than in the remaining regions. Thus, even in the deformed state, the spacer 4c is the information formed by them, in the form of an optically variable Layer against the background of a different optically variable layer 11, recognizable.

Alternatively, the adhesive layer 18 may also be opaque and / or colored, resulting in a corresponding visual impression of the spacers 4c. Likewise, the spacers 4c may be disposed outside the region forming the interference thin film 11 under mechanical pressure.

10a shows a schematic side view of a variant of a moiré magnification arrangement and / or a modulo mapper, as known from PCT / EP 2008/005171 or PCT / EP 2008/005172, the disclosure of which is incorporated in this regard in the present patent. The magnification arrangement has a microlens array 19 which focuses on a microimage array 20 with microimages 20a. In addition to translucent, rigid layers 17, the enlargement unit also has a translucent, compressible, elastically deformable region 4 in the form of an intermediate layer 21. In the undeformed state of the elastically deformable intermediate layer 21 shown in FIG. 10a, the microlenses 19a of the microlens array 19 focus on the plane of the microimages 20a of the microimage assembly 20. In the deformed, compressed state of the elastically deformable interlayer 21 shown in FIG between the microlens array 19 and the microimage array 20, so that the microlenses 19a no longer focus on the plane of the microimages 20a. Thus, the enlarging effect resulting in the undeformed state in the deformed state of the elastically deformable intermediate layer 21 is canceled by the resulting blurred image. FIG. 10 c shows an alternative construction of a moiré magnification arrangement and / or a modulo mapper in an undeformed state of the elastically deformable intermediate layer 21. In this undeformed state, the microlenses 19a do not focus on the associated planes of the microimages 20a. On the other hand, such focusing takes place in a deformed state of the elastically deformable intermediate layer 21, whereby the magnification effect in this exemplary embodiment becomes recognizable only in the deformed state, and thus at and possibly briefly after a mechanical pressure has been exerted.

FIG. 10d shows a further exemplary embodiment of a moire magnification arrangement and / or a modulo mapper. This comprises two consecutive microimage arrangements 20 and 20 '. In the undeformed state of the elastically deformable, compressible intermediate layer 21, the microlenses 19a of the microlens array 19 focus on the planes of the microimages 20a of the front and top microphotograph 20 in the viewing direction. In the deformed state of the elastically deformable interlayer 21, the microlenses 19a focus the microlens array 19 on the planes of the micro images 20a 'of the viewing direction behind the microimage assembly 20'.

FIG. 11 shows a first exemplary embodiment of a production method for producing a coating 3 on an example embossed sawtooth structure with recesses 12 in the foot region of the saw teeth 5. In this case, the coating 3 is applied by oblique vapor deposition in the direction of the flanks of the saw teeth 5, as indicated by the arrows in the figure. As a result, the tips of the saw teeth shadow the foot region of the sawtooth 5 behind it in the vapor deposition direction, whereby arise through recesses 12. The coating 3 may be a layer of metal or other material.

In FIGS. 12a to 12c, a second exemplary embodiment of a production method for producing a coating 3 on an example embossed sawtooth structure with recesses 12 in the foot region of the saw teeth 5 is sketched. In the first process step shown in FIG. 12a, a wash ink 22 is applied to the sawtooth structure. The wash color 22 is of low viscosity and therefore deposits only in the foot region of the sawtooth within the sawtooth structure. Furthermore, the wash paint 22 has a suitable surface tension against the material of the saw teeth, which assists the attachment of the wash paint 22 in only the foot areas. In the second method step illustrated in FIG. 12b, the desired coating 3 is applied over the entire surface by vertical evaporation. However, the application of the coating can also be done otherwise. The wash ink 22 has a highly porous surface, which allows a subsequent washing out of the wash ink 22 together with the overlying coating 3. As a result, the coating 3 shown in FIG. 12 c is produced with recess 12 in the foot region of the saw teeth 5. The use of the wash ink 22 allows in this embodiment, an initially full-surface application of the desired coating 3, which is easy to implement.

In FIGS. 13a to 13b, a third exemplary embodiment of a production method for producing a coating 3 on an example embossed sawtooth structure with recesses 12 in the foot region of the saw teeth 5 is sketched. In the first method step shown in FIG. 13 a, the desired coating 3 is applied over the entire surface. In the second method step illustrated in FIG. 13b, a low-viscosity cover layer is used. applied color 23, which accumulates only in the foot areas of the saw teeth 5, which can be additionally supported by a suitable surface tension of the top coat 23 against the coating 3. The cover color 23 is opaque and covers the coating 3 in the foot areas, whereby its optical effect of the coating 3 is suppressed there, resulting in the same or at least similar effect as the recesses 12 in the embodiments described above.

In FIGS. 14a to 14c and 15, two exemplary embodiments of a production method for producing a coating 3 on an embossed sawtooth structure with recesses 12 in the foot region of the saw teeth 5 are sketched, the coating 3 embossing the sawtooth structure from the die 24 to the flanks of the saw teeth Saw teeth is transferred. For this purpose, the embossing punch 24 is treated in a suitable manner before embossing the sawtooth structure. This may be a metallization transfer in which the coating 3 is a metallization layer. As an embossing die 24, an embossing foil may also be used with particular preference.

In the first exemplary embodiment shown in FIGS. 14a to 14c, in a first method step (FIG. 14a), the desired coating 3 is applied over the whole area to the embossing surface of the embossing punch 24. Subsequently, in a second process step illustrated in FIG. 14 b, the coating 3 is removed again from the tips of the saw teeth of the embossing surface of the embossing punch 24. These tips are easily accessible, so the removal can be done by mechanical brushing, as indicated by the brush 25 in Fig. 14b. The removal of the coating 3 from the tips is facilitated if it is a slightly cleavable coating. As a material for the die 24 is often used a hard paint layer. For example, as a metallization adheres better to such a hard lacquer layer than at the possibly still uncrosslinked or elastic to be embossed layer, an additional adhesive layer 26 is applied to the die 24. After embossing, the adhesive layer 26 remains together with the coating 3 on the embossed structure, that is, the embossed sawtooth structure back. Since the tips of the embossing die come to lie in the foot regions of the saw teeth 5 of the embossing structure during embossing, the desired recesses 12 arise there, as already illustrated in FIG. 12c.

In the second exemplary embodiment shown in FIG. 15, the desired coating 3 is again first applied to the embossing punch 24 over its full area. Subsequently, a low-viscosity adhesive 27 is applied, which is deposited in the foot areas of the sawtooth structure of the die 24. The die 24 consists of a hard lacquer to which the coating 3, which is a metallization layer, adheres better than on the material of the structure to be embossed. As a result, the coating 3 is removed again in the simplest case when removing the embossing die 24 from the embossed structure. In the region of the adhesive 27, however, the coating 3 remains adhered to the embossed structure. Since the foot areas of the sawtooth structure of the die 24 come to lie on the tips of the embossed sawtooth structure, the coating 3 remains on the tips of the embossed sawtooth structure, while the coating 3 in the foot areas of the embossed sawtooth structure is removed again, whereby the desired recesses 12 are formed, as shown in Fig. 12c.

FIGS. 16a and 16b show an exemplary embodiment of a production method for producing microlenses 4e in an elastically deformed Baren area 4 shown with a coating 11 with uniform layer thickness.

In a first method step (FIG. 16a), vertical cylinders 4d are arranged on a translucent, planar layer of an elastically deformable region 4 at the locations at which a microlens is to be produced. Subsequently, an interference thin film 11 is applied by perpendicular evaporation on the flat surface of the elastically deformable region 4 and on the end faces of the cylinder 4d. Since the flat surface and the end faces of the cylinders 4d have parallel surfaces and no area is shaded during vapor deposition, vapor deposition creates layers each having uniform layer thicknesses and thus an interference thin film 11 having a uniform optically variable effect. The planar layer of the elastically deformable region 4 and the cylinders 4d, which are also part of the elastically deformable region, form a continuous region of the same material.

In a second method step (FIG. 16b), the planar layer and the cylinders 4d are heated, so that the elastically deformable region 4 runs. The elastically deformable region 4 consists of a thermoplastic material. As a result, the cylinders 4d and the plane structure join and form microlenses 4e below the interference thin film 11 at the positions where the cylinders 4d are disposed. Thus, a security element is provided with an elastically deformable region with microlenses 4 e, which carry an optically variable coating in the form of a uniform interference thin film 11. When passing the cylinder to the microlenses and also when deforming the microlenses, the applied interference thin film may possibly break, which is irrelevant to the color impression. Such bleeding of already coated cylinders 4d to coated microlenses 4e can also be realized in materials that are not elastically deformier bar.

In general, the elastically deformable regions 4 in the various embodiments may contain additional particles, not shown, which are filled with a gas or a liquid and thus compensate for a deformation and optionally compression of the respective elastically deformable region 4 with a lower mechanical resistance than the remaining material the elastically deformable region 4. The elastically deformable regions 4 may each also be foamed, whereby the volume of such an elastically deformable region 4 can be additionally increased and this then elastically deformed to a greater extent, in particular can be compressed.

Particularly pronounced lens structures are advantageous if the cylinders 4d are made of a material which is elastically deformable differently than the elastically deformable region 4. Alternatively, the cylinders 4d or the region 4 can also consist of a non-deformable material. The material of the cylinder 4d in this case has a lower melting temperature than the region 4, so that only the cylinders 4d melt during heating. Due to the surface tension, the cylinders 4d, similar to a drop of water on a plate, transform into lenticular structures.

Claims

Patent claims

1. Security element for a data carrier, comprising

- An elastically deformable area and

a functional structure that creates a visual impression on a viewer,

wherein the elastically deformable region and the functional structure interact with each other such that in an undeformed state of the elastically deformable region, there is a visual impression of the functional structure different from the visual impression in a deformed state of the elastically deformable region.

2. Security element according to claim 1, characterized in that in the undeformed state of the elastically deformable region, the spatial position and / or the alignment of at least a portion of the functional structure of the spatial position and / or the orientation in the deformed state of the elastically deformable region differs and the functional structure preferably contains an optically variable element.

3. Security element according to claim 2, characterized in that the elastically deformable region comprises the functional structure.

4. A security element according to claim 2, characterized in that the functional structure is an optically variable element, preferably an interference thin film, interference thin-film pigments or liquid crystal pigment, which is firmly bonded to a surface of the elastically deformable region.

5. Security element according to claim 4, characterized in that the elastically deformable region has a layer-like structure, on the elastically deformable region a layer of a rigid material is arranged, which is mechanically connected to the elastically deformable region, and the functional structure on a surface the layer of rigid material is arranged, wherein this layer preferably comprises a plurality of elements which are individually tiltable.

6. The security element according to claim 3 or 4, characterized in that the elastically deformable region has a layer-like structure with spatially varying layer thickness, preferably a sawtooth or lamellar structure, on the edges of the functional structure, preferably layered, is arranged, wherein particularly preferably the functional structure has recesses in the foot region of the sawtooth structure or is concealed and / or the tips of the sawtooth or lamellar structure are firmly connected to each other by a translucent layer.

7. A security element according to claim 1, characterized in that when looking at the functional structure in the undeformed state of the elastically deformable region within the security element results in a light path which differs from the light path in the deformed state of the elastically deformable region.

8. Security element according to claim 7, characterized in that the functional structure comprises a first element and a second, in the viewing direction in front of the first element arranged, translucent element, wherein the first and second members are spaced from each other in the undeformed state of the elastically deformable portion and are in contact with each other in the deformed state of the elastically deformable portion.

9. A security element according to claim 8, characterized in that the second element at spacing from the first element on the opposite surface of the first element is totally reflective, in particular retro-reflective and allowed in contact with the first element reviewing the first element.

10. The security element according to claim 8, characterized in that the second element comprises a partially reflecting and a dielectric layer and the first element comprises a reflective layer or that the second element comprises a partially reflecting layer and the first element comprises a dielectric layer and a reflective layer , which are arranged to each other such that upon contact of the first and second element an interference thin film is present.

11. A security element according to claim 7, characterized in that the elastically deformable region and the functional structure are each formed as a layer and the elastically deformable region is translucent and is arranged in the viewing direction in front of the functional structure.

12. A security element according to claim 11, characterized in that the elastically deformable region satisfies the condition for a retro-reflection in the undeformed state and does not fulfill the condition for the retro-reflection in the deformed state.

13. The security element according to claim 11, characterized in that the security element comprises a moire magnification arrangement or a modulo mapper with a microlens array and a microimage array, wherein the functional structure comprises the microimage array and the elastically deformable area comprises a layer arranged between microlens array and microimage array so that the spatial distance of the microlens array from the microimage array in the undeformed state of the elastically deformable area is different from the distance in the deformed state of the elastically deformable area.

14. A security element according to claim 11, characterized in that the elastically deformable region has a spatially varying layer thickness and the functional structure forms an optically variable layer, wherein preferably the elastically deformable region has a sawtooth structure and / or the tips of the sawtooth structure by a further translucent Zente layer are firmly connected.

15. A security element according to claim 14, characterized in that the elastically deformable region on the flanks of the sawtooth structure at least partially carries a coating which preferably has or is concealed in the foot region of the sawtooth structure recesses.

16. A security element according to claim 11, characterized in that in the viewing direction in front of the elastically deformable region, a further translucent layer of a rigid material is arranged, which is mechanically connected to the elastically deformable region and preferably comprises a plurality of elements which are individually tiltable ,

17. The security element according to claim 7, characterized in that the elastically deformable region and the functional structure are each formed as a layer, the elastically deformable region is translucent and comprises microlenses, and the functional structure comprises an optically variable coating of the microlenses.

18. Security element according to one of the preceding claims, characterized in that the elastically deformable region has a temporal hysteresis during deformation.

19. A method for producing a security element for a data carrier, comprising the steps:

Providing an elastically deformable region, providing a functional structure and establishing elastically deformable region and functional region such that they interact with one another so that, in an undeformed state of the elastically deformable region, a different visual impression of the functional structure than in a deformed state of the functional structure elastically deformable area results.

20. The method of claim 19, wherein providing the elastically deformable region comprises the steps of:

Providing a plastic layer, in particular an adhesive, resin or embossing lacquer layer,

Embossing of the plastic layer by means of a stamping die for producing an embossed structure in the plastic layer, and Adjusting the elasticity and preferably the compression behavior of the plastic layer, preferably by crosslinking, so that the embossed structure is elastically deformable and preferably compressible.

21. The method of claim 20, wherein embossing structure and dies have a regular sawtooth structure.

22. The method of claim 21, comprising the further step:

Applying a visual impression-producing coating on the embossed structure, which has recesses in the foot region of the saw teeth of the sawtooth structure or is not optically active and which is preferably part of the functional structure and preferably a metallization, liquid crystal pigment or thin film

Comprises interference pigment layer,

either by:

Applying the coating by oblique vapor deposition of the embossing structure in the direction of the flanks of the sawtooth structure, so that the tips of the saw teeth of the sawtooth structure shade the foot region of the adjacent sawtooth,

- or by:

Applying a low-viscosity washing paint on the embossed structure, full application of the coating and washing out of the washing paint, or by:

full-surface application of the coating on the embossed structure and application of a low-viscosity topcoat,

or by:

application of the coating over the full area to the embossing stamp, removal of the coating at the tips of the embossing stamp, application of an adhesive layer on the embossing stamp and

Transfer of the coating to the embossed structure when embossing the plastic layer,

or by:

full-surface application of the coating on the die,

Apply a low viscosity adhesive to the coating of the

Embossing stamp and

Transferring the coating on the embossed structure when embossing the plastic layer.

23. The method according to claim 19, comprising the further steps:

Providing a flat layer with vertically arranged cylinders to provide the elastically deformable region, wherein

Layer and cylinder of the same or a different thermoplastic, translucent plastic, in particular of an adhesive or a paint consist, Applying an interference thin film on the planar layer and the end faces of the cylinder by vertical evaporation to create the functional structure, and

- Setting up elastically deformable area and functional area by heating the planar layer and the cylinder so that they run to microlenses.

24. Data carrier, in particular value document, branded articles and the like, comprising a security element according to one of claims 1 to 18.

25. Transfer element comprising a security element according to one of claims 1 to 18, which is preferably applied detachably on a carrier layer.

26. Use of an elastically deformable region in a security element such that, in an undeformed state of the elastically deformable region, a visual impression results in a viewer that differs from the visual impression in a deformed state of the elastically deformable region.