DE102012018774A1 - Security element with representation arrangement - Google Patents

Abstract

The invention contains a security element (100) for securing security papers, documents of value and other data carriers, with a display arrangement for displaying one or more target images (14A, 14B), the motifs of which are each represented by visually recognizable, contrasting metallic (16A, 16B) and non- metallic (18A, 18b) partial areas are formed, wherein the display arrangement contains a motif layer (106) with a plurality of metallized picture elements and non-metallized picture elements and a viewing grid spaced apart from the motif layer and comprising a plurality of viewing elements (104), and the metallized picture elements and the non-metallized picture elements, when viewed with the viewing grid, generate the visually recognizable, contrasting metallic and non-metallic partial areas of the target images (14A, 14B). According to the invention it is provided that the motif layer (106) comprises an embossed structure with elevations (118) and depressions (110, 120), the non-metallized image elements of the motif layer being formed by non-metallized elevations (118) of the embossed structure and the metallic Image elements are formed by essentially metallized depressions (110, 120) of the embossed structure, and that at least some of the essentially metallized depressions (110) contain small, raised support structures (92) in an area proportion between 0.1% and 25% are not visually recognizable when viewed with the viewing grid.

Description

The invention relates to a security element for securing security papers, documents of value and other data carriers, having a representation arrangement for displaying one or more reference images whose motifs are each formed by visually recognizable, contrasting metallic and non-metallic subregions. The invention also relates to methods for producing such a security element, as well as equipped with a security element disk.

Data carriers, such as valuables or identity documents, but also other valuables, such as branded articles, are often provided with security elements for securing purposes, which permit verification of the authenticity of the data carrier and at the same time serve as protection against unauthorized reproduction. 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 counterfeit-endangered papers, such as passports and other identity documents, credit cards, health cards, as well as product security elements such as labels, seals, packaging and the like. The term "data carrier" in the following includes all such objects, documents and product protection means.

Security elements with optically variable elements, which give the viewer a different image impression from different viewing angles, play a special role in securing, since these can not be reproduced even with high-quality color copying machines. For example, the security elements can contain a tilting or changing picture, a moving picture or a stereo picture as a display arrangement.

For some time, so-called moiré magnification arrangements are used as security features. The principal operation of such moiré magnification arrangements is 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, moiré 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 moiré pattern consisting of a periodic arrangement of enlarged and optionally rotated images of the elements of the image raster.

Contain the representations of the security elements differently colored motifs, they can be printed usually in a desired shape. The production is more difficult in motifs which are to be formed by contrasting metallic and non-metallic subregions, since metallizations can generally not be generated directly in motif form, but only over the entire surface, for example by vapor deposition of a metal layer in a vacuum vapor deposition process.

Based on this, the present invention seeks to provide a security element of the type mentioned, which can be reliably manufactured with predetermined metallic and non-metallic portions. Also, advantageous methods for producing security elements of the type mentioned are to be specified.

This object is solved by the features of the independent claims. Further developments of the invention are the subject of the dependent claims.

According to the invention, the display arrangement of a security element mentioned above comprises a motif layer having a plurality of metallized pixels and non-metallized pixels and a viewing grid spaced from the motif layer of a plurality of viewing elements, the metallized pixels and the non-metallized pixels viewed when viewed with the Viewing grid to produce the visually recognizable, contrasting metallic and non-metallic portions of the target images. Furthermore, the motif layer according to the invention comprises an embossed structure with elevations and depressions, wherein the non-metallized picture elements of the motif layer are formed by non-metallized elevations of the embossed structure and the metallic picture elements are formed by substantially metallized depressions of the embossed structure. At least a portion of the substantially metallized depressions contain, in an area fraction between 0.1% and 25%, small, raised support structures which are not visually discernible when viewed with the viewing grid.

Since the support structures arranged in the depressions are themselves generally not metallized, as explained in more detail below, the depressions with the support structures are referred to as "substantially" metallized in the context of this description. The metallic impression of the metallic picture elements formed by the depressions is not impaired by the support structures for the viewer, since these are not visually recognizable when viewed with the viewing grid.

In an advantageous embodiment contains at least a portion of the substantially metallized Recesses the support structures in an area ratio between 2.5% and 10%.

Furthermore, it is conceivable in principle, although not presently preferred, for at least some of the essentially metallized depressions to contain the support structures in an area fraction of more than 25%. In particular, at least under suitable lighting conditions, even with a comparatively high areal proportion of the support structures of, for example, 50%, the impairment of the metallic impression by the support structures can be regarded as negligible for the viewer, so that the target images remain visually recognizable, albeit with reduced contrast.

In an advantageous embodiment, the support structures in the depressions are irregular, for example, stochastically distributed. Alternatively, the support structures in the depressions may also be arranged regularly in a grid whose moiré effects with the viewing grid remain below the resolution limit of the human eye or, as explained in more detail below, are completely avoided by suitable arrangement of the support structures with respect to the viewing elements ,

The height of the support structures preferably corresponds to the depth of the recesses in which they are arranged. In general, however, the height of the support structures may also be lower, as long as they ensure a sufficient distance of an adhesive-coated acceptor film from the bottom of the recesses in the production, as described in more detail below.

In advantageous embodiments, the support structures comprise pillars of circular, oval, triangular, rectangular or polygonal cross-section, the cross-section of the pillars preferably having an area between 0.25 μm ² and 25 μm ² .

In other, likewise advantageous embodiments, the support structures comprise irregular, continuous web structures in which the width of the web structures is preferably between 0.1 μm and 5 μm.

According to further, likewise advantageous embodiments, the support structures comprise non-contiguous web elements which each consist of one or more line pieces and whose width is preferably between 0.1 μm and 5 μm.

Also advantageously, the support structures may comprise straight, parallel web elements whose width is preferably between 0.1 μm and 5 μm.

The mentioned types of support structures can be combined with each other so that different recesses contain different support structure types. Also in the same recess several different types of support structures can be provided.

Furthermore, it can be provided with advantage that the support structures in a subarea contain hidden information in the form of characters or a coding so as to integrate an additional authenticity feature in the security element.

Preferably, all depressions whose dimensions exceed a maximum dimension, provided with support structures of the type mentioned. The maximum dimensions which are advantageous for a representation arrangement according to the invention depend on various parameters, in particular the depth of the depressions, the pressure used during the laminating process, the thickness of the adhesive layer, etc. Advantageous maximum dimensions can be determined by a person skilled in the art for each parameter selection with the aid of less orienting tests. By way of example, all depressions which have a dimension of more than 30 μm (maximum dimension) in at least one spatial direction are provided with support structures.

The viewing elements of the viewing grid are advantageously formed by spherical lenses, aspherical lenses, cylindrical lenses or one or two-dimensionally focusing micro-cavity mirrors. In further preferred variants of the invention, the viewing elements are formed by pinhole apertures, slotted apertures, apertured apertured or slit apertures, Fresnel lenses, GRIN lenses (Gradient Refraction Index), zone plates, holographic lenses, Fresnel mirrors, zone mirrors or other elements with focussing or blanking effects.

The motif layer of the representation arrangement preferably lies in the focal plane of the lenses or concave mirrors.

In a preferred embodiment, the viewing elements are formed by cylindrical lenses and the support structures are formed by parallel, straight web elements, which are at an angle between 60 ° and 120 °, preferably between 85 ° and 95 °, particularly preferably of 90 ° to the axis of the cylindrical lenses extend. In this way, even with a regular arrangement of Avoid supporting structures in a grid moire effects with the viewing grid.

The representation arrangement itself may in particular be a change picture, a motion picture, a morph picture or a stereo picture, but with advantage also a micro-optical display arrangement, in particular a moire magnification arrangement, a magnification arrangement of the moire type or a modulo magnification arrangement. The basic principle of such micro-optical representation arrangements is in the document WO 2009/000528 A1 explained, the disclosure of which is included in the present description in this regard.

As stated above, the motif layer of the presentation arrangement is preferably located in the focal plane of the lenses or concave mirrors. The motif layer may, however, in particular in the case of non-magnifying representational arrangements, for example in the case of non-enlarging change images, also lie in a plane (parallel) which deviates slightly from the focal plane of the lenses or concave mirrors. In this case, although the angular ranges in which the motifs are recognizable at the same time (or in which one motif "transitions" into another), at the expense of the angular ranges in which only one of the motifs can be seen, the contrast or contrast increases However, this does not affect the sharpness of the subjects.

In advantageous embodiments, an additional structuring, preferably a diffractive structure, a structure having a matting or scattering effect and / or a nanostructuring, is introduced into the depressions of the embossed structure.

Likewise advantageously, the motif layer can be provided over the entire area or over a partial area, for example in the form of a halftone display, with at least one printing ink and / or with at least one reflective coating material, preferably a metal, a color-shifting system, a high refractive index material, metal pigments or effect pigments.

The invention also includes a data carrier equipped with a security element of the type described above. The security element may in particular be embedded in the data carrier or applied to the data carrier.

• (a) Herstellen einer Donorfolie durch
• (i) Ausbilden einer Prägestruktur mit Erhebungen und Vertiefungen und mit in den Vertiefungen in einem Flächenanteil zwischen 0,1% und 25% angeordneten erhabenen Stützstrukturen, mindestens in einem Teilbereich einer Hauptfläche eines ersten Folienmaterials oder in einer pragbaren Schicht auf mindestens einem Teilbereich einer Hauptfläche eines ersten Folienmaterials, wobei die Erhebungen und die Vertiefungen Bildelemente einer Motivschicht der Darstellungsanordnung erzeugen, die bei Betrachtung der Motivschicht mit einem Betrachtungsraster der Darstellungsanordnung visuell erkennbare, kontrastierende metallische und nicht-metallische Teilbereiche der Sollbilder erzeugen,
• (ii) Auftragen einer Metallbeschichtung mindestens auf einen Teilbereich der Prägestruktur,
• (b) Herstellen einer Akzeptorfolie durch Auftragen einer Klebstoffschicht mindestens auf einen Teilbereich einer Hauptfläche eines zweiten Folienmaterials,
• (c) Kaschieren der Donorfolie und der Akzeptorfolie mittels der Klebstoffschicht derart, dass mindestens ein Teilbereich der beschichteten Prägestruktur und ein Teilbereich der Klebstoffschicht miteinander in Kontakt kommen, wobei in dem Kontaktbereich die Metallbeschichtung auf den Erhebungen der Prägestruktur mit der Klebstoffschicht der Akzeptorfolie verklebt,
• (d1) Transferieren der im Kontaktbereich auf den Erhebungen der Donorfolie vorliegenden Metallbeschichtung auf die Klebstoffschicht der Akzeptorfolie durch Trennen von Donorfolie und Akzeptorfolie, wodurch aus der Donorfolie eine Motivschicht mit einer Mehrzahl von metallisierten Bildelementen und nicht-metallisierten Bildelementen entsteht, und
• (e1) Herstellen einer Darstellungsanordnung durch Kombinieren der Motivschicht der Donorfolie mit einem Betrachtungsraster aus einer Mehrzahl von Betrachtungselementen, derart dass die metallisierten Bildelemente und die nicht-metallisierten Bildelemente bei Betrachtung mit dem Betrachtungsraster die visuell erkennbaren, kontrastierenden metallischen und nicht-metallischen Teilbereiche der Sollbilder erzeugen.

The invention also includes a method for producing a security element having a representation arrangement for displaying one or more target images whose motifs are each formed by visually recognizable, contrasting metallic and non-metallic subregions, with the following method steps:

• (a) preparing a donor sheet
• (i) forming an embossed structure with protrusions and depressions and with raised support structures arranged in the depressions in an area proportion between 0.1% and 25%, at least in a partial area of a main area of a first foil material or in a noticeable layer on at least a partial area of a main area a first foil material, wherein the elevations and the depressions generate image elements of a motif layer of the representation arrangement which, when the motif layer is viewed with a viewing grid of the presentation arrangement, produce visually recognizable, contrasting metallic and non-metallic parts of the target images,
• (ii) applying a metal coating to at least a portion of the embossed structure,
• (b) producing an acceptor film by applying an adhesive layer to at least a portion of a major surface of a second film material,
• (c) laminating the donor film and the acceptor film by means of the adhesive layer in such a way that at least a partial region of the coated embossed structure and a partial region of the adhesive layer come into contact with one another, wherein in the contact region the metal coating adheres to the elevations of the embossed structure with the adhesive layer of the acceptor film,
• (d1) transferring the metal coating present in the contact region on the elevations of the donor film to the adhesive layer of the acceptor film by separating donor film and acceptor film, whereby a motif layer having a plurality of metallized picture elements and non-metallized picture elements is formed from the donor film, and
• (e1) producing a representation arrangement by combining the motif layer of the donor sheet with a viewing grid of a plurality of viewing elements such that the metallized picture elements and the non-metallized picture elements, when viewed with the viewing grid, form the visually recognizable, contrasting metallic and non-metallic portions of the target images produce.

In a preferred embodiment, the viewing elements are impressed before or after step (a) (i) in the main surface of the first sheet material opposite the main surface of the first sheet material or in an embossable layer on the other major surface of the first sheet material opposite the main surface.

In other, likewise advantageous embodiments, an additional structuring, preferably a diffractive structure, a structure, is introduced into the depressions of the embossed structure in step (a) matting or scattering effect and / or a nanostructuring introduced.

• (a) Herstellen einer Donorfolie durch
• (i) Ausbilden einer Prägestruktur mit Erhebungen und Vertiefungen und mit in den Vertiefungen in einem Flächenanteil zwischen 0,1% und 25% angeordneten erhabenen Stützstrukturen, mindestens in einem Teilbereich einer Hauptfläche eines ersten Folienmaterials oder in einer prägbaren Schicht auf mindestens einem Teilbereich einer Hauptfläche eines ersten Folienmaterials, wobei die Erhebungen und die Vertiefungen Bildelemente einer Motivschicht der Darstellungsanordnung erzeugen, die bei Betrachtung der Motivschicht mit einem Betrachtungsraster der Darstellungsanordnung visuell erkennbare, kontrastierende metallische und nicht-metallische Teilbereiche der Sollbilder erzeugen,
• (ii) Auftragen einer Metallbeschichtung mindestens auf einen Teilbereich der Prägestruktur,
• (b) Herstellen einer Akzeptorfolie durch Auftragen einer Klebstoffschicht mindestens auf einen Teilbereich einer Hauptfläche eines zweiten Folienmaterials,
• (c) Kaschieren der Donorfolie und der Akzeptorfolie mittels der Klebstoffschicht derart, dass mindestens ein Teilbereich der beschichteten Prägestruktur und ein Teilbereich der Klebstoffschicht miteinander in Kontakt kommen, wobei in dem Kontaktbereich die Metallbeschichtung auf den Erhebungen der Prägestruktur mit der Klebstoffschicht der Akzeptorfolie verklebt,
• (d2) Transferieren der im Kontaktbereich auf den Erhebungen der Donorfolie vorliegenden Metallbeschichtung auf die Klebstoffschicht der Akzeptorfolie durch Trennen von Donorfolie und Akzeptorfolie, wodurch aus der Akzeptorfolie eine Motivschicht mit einer Mehrzahl von metallisierten Bildelementen und nicht-metallisierten Bildelementen entsteht, und
• (e2) Herstellen einer Darstellungsanordnung durch Kombinieren der Motivschicht der Akzeptorfolie mit einem Betrachtungsraster aus einer Mehrzahl von Betrachtungselementen, derart dass die metallisierten Bildelemente und die nicht-metallisierten Bildelemente bei Betrachtung mit dem Betrachtungsraster die visuell erkennbaren, kontrastierenden metallischen und nicht-metallischen Teilbereiche der Sollbilder erzeugen.

In addition, the invention also includes a method for producing a security element having a representation arrangement for displaying one or more target images whose motifs are each formed by visually recognizable, contrasting metallic and non-metallic subregions, with the following method steps:

• (a) preparing a donor sheet
• (i) forming an embossed structure with elevations and depressions and with raised support structures arranged in the depressions in an area fraction between 0.1% and 25%, at least in a partial area of a main area of a first foil material or in an embossable layer on at least a partial area of a main area a first foil material, wherein the elevations and the depressions generate image elements of a motif layer of the representation arrangement which, when the motif layer is viewed with a viewing grid of the presentation arrangement, produce visually recognizable, contrasting metallic and non-metallic parts of the target images,
• (ii) applying a metal coating to at least a portion of the embossed structure,
• (b) producing an acceptor film by applying an adhesive layer to at least a portion of a major surface of a second film material,
• (c) laminating the donor film and the acceptor film by means of the adhesive layer in such a way that at least a partial region of the coated embossed structure and a partial region of the adhesive layer come into contact with one another, wherein in the contact region the metal coating adheres to the elevations of the embossed structure with the adhesive layer of the acceptor film,
• (d2) transferring the metal coating present in the contact region on the elevations of the donor film to the adhesive layer of the acceptor film by separating donor film and acceptor film, whereby a motif layer having a plurality of metallized picture elements and non-metallized picture elements is produced from the acceptor film, and
• (e2) producing a display arrangement by combining the motif layer of the acceptor sheet with a viewing grid of a plurality of viewing elements, such that the metallized pixels and the non-metallized pixels viewed in viewing view overlap the visually recognizable, contrasting metallic and non-metallic portions of the target images produce.

In advantageous embodiments, in step (d1) or in step (d2) of the above method, the metal coating present in the contact region on the raised support structures of the donor film can also be transferred to the adhesive layer of the acceptor film by separating donor film and acceptor film.

On the embossed structure, the metal coating is applied over the entire surface or part of the area. It should be noted that the metal coating must later be partially replaced again. It must therefore not adhere too strongly to the substrate, at least less strongly than the achievable bond strength with the later to be used adhesive. A sufficiently low adhesive force may possibly already be achieved by a suitable choice of the materials for the film material or the embossable layer. Preferably, however, prior to the application of the metal coating in step (a) (ii), an adhesion-reducing treatment of the surface of the embossed structure to be coated is undertaken.

In the above methods, the motif layer after step (d1) or step (d2) is advantageously over the entire surface or part of the surface, for example in the form of a halftone image, with at least one printing ink and / or with at least one reflective coating material, preferably a metal, a color-shifting system , a high refractive index material, metal pigments or effect pigments. With particular advantage, one or more printing inks are first applied and then additionally a reflective coating material, in particular a full-surface metallization.

Further exemplary embodiments and advantages of the invention are explained below with reference to the figures, in the representation of which a representation true to scale and proportion has been dispensed with in order to increase the clarity.

Show it:

1 a schematic representation of a banknote with a security element according to the invention, which contains a change picture with two different target images,

2 schematically the structure of a security element according to the invention, for example, the transfer element of 1 in cross section,

3 schematically the motif layer of a security element according to the invention,

4 in (a) and (b) schematically the donor sheet and the acceptor sheet in intermediate steps of the production of a security element according to the invention,

5 the acceptor foil of the 4 (b) after the separation of the two films,

6 in (a) and (b) schematically shows the donor film in two intermediate steps in the production of a conventional motif layer,

7 in (a) and (b) schematically the donor film in two intermediate steps in the production of a motif layer of a security element according to the invention,

8th . 9 some advantageous designs of inventive support structures, and

10 an embodiment of a security element with a representation arrangement in the form of a modulo magnification arrangement.

The invention will now be explained using the example of security elements for banknotes and other value documents. 1 shows a schematic representation of a banknote 10 that with a security element according to the invention in the form of a glued transfer element 12 is provided. The transfer element 12 represents in the embodiment, a change picture that the viewer from two different viewing directions different target images 14A respectively. 14B presents. The target images 14A . 14B each show a motif that by visually recognizable and contrasting metallic and non-metallic portions 16A . 16B respectively. 18A . 18B is formed.

In the exemplary embodiment, the motifs are formed by metallic glossy letters "A" and "B" in front of a monochrome, non-metallic background, the viewer viewed obliquely from the left the letter "A", viewed obliquely from the right the letter "B "Perceives. Tipping the banknote changes the appearance of the security element between the two target images 14A . 14B back and forth. It is understood that in practice mostly complex motifs, for example the denomination of the banknote, geometric patterns, portraits, architectural, technical or nature motives are used. The motifs can also be present in particular in the form of screened half-tone representations. Also, a change picture may contain more than two reference pictures or the security element may have a motion picture, a pump picture, a morph picture or a stereo picture instead of a change picture. In addition, the security element can also be designed such that the appearance does not change back and forth as described above in an "east-west tilting" of the security element between two or more target images, but in a tilting about any other axis, for example a "north-south tipping". In a north-south tilting the viewer perceives when viewed obliquely from above, for example, the letter "A" and viewed obliquely from below the letter "B" true.

However, the invention is not limited in any way to alternating images or the variants mentioned. Rather, the invention can be found in all representational arrangements with a partly metallic and partly non-metallic motif layer application. The invention is also not limited to the banknote transfer elements used for illustration, but can also be used, for example, in security threads, wide security strips, or cover sheets placed over a window area or through opening of a document.

2 shows schematically the structure of a security element according to the invention 20 , For example, the transfer element 12 of the 1 in cross section. Shown here are, as in the other figures, only necessary for the explanation of the principle of operation parts of the structure.

The security element 20 of the 2 has a carrier 22 in the form of a transparent plastic film, for example, about 20 microns thick PET film. The top of the vehicle 22 is with a viewing grid in the form of a plurality of parallel cylindrical lenses 24 provided, the width b in the embodiment b = 20 microns. On the underside of the carrier 22 is a motif layer 26 formed in parallel to the cylindrical lenses 24 running narrow stripes 28A . 28B is divided into a width of 10 microns each. The carrier foil 22 and the cylindrical lenses 24 are coordinated so that the motif layer 26 in the focal plane of the cylindrical lenses 24 located.

Looking at the security element 20 from the viewing direction 30A are because of the focusing effect of the cylindrical lenses 24 only the stripes 28A and when viewed from viewing direction 30B only the stripes 28B visible, noticeable. The Stripes 28A respectively. 28B Therefore, set for the viewer to the desired target images, such as the target images 14A . 14B of the 1 together. When designing the motif layer 26 were the desired target images 14A . 14B in a conventional manner in parallel strips 28A . 28B divided the desired width and the strips thus obtained alternately to the motif layer 26 composed. The parallel stripes 28A . 28B do not have to be the same width. For example, the strip 28A also a width of 5 microns and the strip 28B have a width of 15 microns. The proportion of the respective strip in the total width affects the angle range in which the desired target images 14A . 14B are visible to the viewer.

As in 2 shown contains the security element 20 typically more layers 32 such as protective, covering or other functional layers, which are not essential to the present invention and are therefore not described in detail.

Tilting or alternating pictures showing different colored subjects are known. To create the different colored motifs, the in the individual stripes 28A . 28B lying motif parts of the target images usually printed in the desired shape. The peculiarity of the alternating pictures described here consists now in the fact that the motives of the Sollbilder 14A . 14B are formed by contrasting metallic and non-metallic portions. As a rule, however, metallizations can not be generated directly in motif form, but only over the entire surface, for example by vapor deposition of a metal layer in a vacuum vapor deposition process.

In order nevertheless to be able to produce the required structuring into metallic and non-metallic subregions, the procedure is as follows: With reference to the schematic representation of FIG 3 includes the motif layer 26 one on the carrier 22 applied pre-story 40 with an embossed structure with elevations 42 and depressions 44 , The surveys 42 The embossed structure are non-metallized and represent non-metallized picture elements, which when viewed the non-metallic portions 18A . 18B generate the target images. The wells 44 In contrast, the embossed structure is essentially metallized 46 provide and represent metallized picture elements that when viewed the metallic portions 16A . 16B form the target images.

The procedure in the production of such a security element is in 4 illustrated. With reference first to 4 (a) is doing from a donor sheet 50 in the form of a transparent plastic film 22 assumed that with a transparent embossable layer 40 is coated. Into the embossable layer 40 an embossed structure is imprinted, its sequence of elevations 42 and depressions 44 is predetermined by the motives of the desired target images, for example, the wells 44 the foreground and the elevations 42 represent the background of the respective motifs or vice versa. The structure depth of the embossed structure is preferably in the range between 0.2 μm and 10 μm and the line width is preferably in the range between 0.2 μm and the width of the strips 28A . 28B , typically 5 μm to 20 μm.

On the embossed structure is then over the entire surface of a metal, such as aluminum deposited by vapor deposition, so that a full-surface metal coating 48 arises. As in 4 (a) shown, are initially both the surveys 42 as well as the depressions 44 with the metal coating 48 covered. Before the vapor deposition of the metal coating 48 For example, an adhesion-reducing treatment of the surface to be coated is preferably carried out. The thickness of the metal coating 48 depends on the desired later reflection behavior and on the metal used and is for example advantageously about 30 to 50 nm for aluminum.

The donor sheet thus produced 50 will now use an in 4 (b) shown acceptor 52 brought into contact. The acceptor foil 52 consists of a transparent film 54 , which on one of its main surfaces over the entire surface with a transparent adhesive layer 56 is coated. The donor sheet 50 and the acceptor sheet 52 are in this case, preferably under increased pressure and elevated temperature, compressed to the metallization of the surveys 42 from the donor sheet 50 on the acceptor foil 52 transferred to. After separating the two films, preferably by separating winding, the surveys 42 the donor sheet 50 demetallized while the metal coating 48 in the wells 44 was not transferred and therefore on the donor sheet 50 remains as in 3 shown.

As in 5 shown contains the acceptor film 52 after separation, the transferred metal coating parts 58 the surveys 42 and thus has a metallization pattern inverted compared to the donor sheet. While present, the generation of a change image using the donor sheet 50 is described in more detail, can also be a change image using the acceptor 52 getting produced.

One difficulty of the described metal transfer process may result from the sequence of bumps 42 and depressions 44 the embossed structure is predetermined by the motives of the target images, so that there is usually no regular alternating sequence of elevations and depressions, as in the schematic representation of 3 and 4 shown. Rather, with arbitrary choice of subject, large contiguous elevation or depression areas can result, which should be demetallised in the finished security element (elevation areas) or metallized (depression areas). While large land areas can be demetallized easily with the described metal transfer process, the fate of metallization in large recessed areas can be problematic.

To illustrate the possible problems shows 6 an area 60 the motif layer 26 in which both target images 14A . 14B have the alternating image metallized portions. In the embodiment of 1 For example, these are those surface areas of the transfer element 12 in which the metallic parts of the letters "A" and "B" overlap. Since metallized picture elements are formed in the described metal transfer method by depressions of the embossed structure, the embossed structure in this area contains both in the strips 28A of the first target image as well as in the strip 28B of the second target image depressions. This can create a large contiguous well area 62 which, depending on the concrete form of the motifs, can have an extent of more than 100 μm or even several millimeters.

6 (a) first shows an intermediate step in the production of the security element, namely the donor sheet 50 after full-surface coating of the embossed structure with metal 48 , according to the situation of 4 (a) , In the subsequent laminating process with the acceptor film shown in dashed lines 52 of the 4 (b) can the adhesive layer 56 the acceptor film in the large recessed areas 62 pushed through to the bottom of the depression so that the acceptor foil 52 also there with the metal coating 48 bonded. During the subsequent separation winding, the bonding then undesirably also causes metal from the depression area 62 removed, so that in 6 (b) shown metallization error 64 arise.

To such metallization errors 64 to avoid are at the in 7 shown embossed structure in those well areas 72 the pre-history 40 that have more than two strip widths 28A . 28B occupy, additional support structures 70 intended. At the support structures 70 they are small raised structures, in particular, ridges or abutments, which, as in 7 (a) shown in the larger well areas 72 dipping the acceptor foil 52 to the bottom of the recess and thus the unwanted transfer of metal 48 from the wells 72 prevent it from happening.

As with the parting usually also on the support structures 70 applied metal is removed, the support structures need 70 be designed so that they or a possibly missing there metallization in the consideration of the motif layer with the viewing grid are not visible visually. The support structures 70 This is fundamentally different from non-metallized surveys 42 , which are precisely the non-metallized picture elements which, when viewed with the viewing grid, produce the visually recognizable non-metallic subregions of the target images.

In the exemplary embodiment shown, the visual unrecognizability of the support structures 70 This ensures that the support structures 70 on the one hand only 2.5% of the area of the depression 72 in which they are arranged, occupy, and that the support structures 70 also not in the grid of microlenses 24 or the strip 28A . 28B are arranged. This can be done, for example, by an irregular arrangement of the support structures 70 be achieved, or even by a regular arrangement in a grid whose moiré effects with the lenticular grid 24 stay below the limit of resolution of the human eye. In the case of display arrangements with cylindrical lenses, supporting structures are also particularly advantageous whose greatest extent extends largely perpendicular to the axis of the cylindrical lenses.

Some advantageous designs of inventive support structures are in the 8th and 9 illustrated. The figures show in plan view of the motif layer only a few of the support structures, as they can be arranged over the surface of a large-scale depression.

In the 8th Support structures shown can be used both in display arrangements with cylindrical lenses as well as in display arrangements with non-cylindrical lenses, such as the above-mentioned modulo magnification arrangements. At the buttresses 80 it is a small cylindrical elevations with a cross-sectional diameter of 0.7 microns to 2 microns. The cross section of the buttresses 80 may also be non-circular, for example oval, triangular, rectangular or generally polygonal. The simultaneous use of buttresses 80 with different cross-sections also suppresses possible moiré effects. In 8th are the buttresses 80 arranged irregularly, but there is also a regular arrangement into consideration, which generates no visible moiré effects with the viewing grid.

In the 8th Also shown supporting webs 82 are narrow, non-contiguous webs with a width of 0.1 microns to 5 microns and a length of several microns. They can also be considered as supporting pillars with rectangular cross section.

The support structures can continue through irregular, related web structures 84 be formed as in the lower left in 8th shown. Another variant is the bottom right in 8th shown web elements 86 each composed of one or more line pieces. With such web elements 86 can in addition a hidden information 88 , such as the logo "G + D" integrated into the motif layer of the security element. The hidden information 88 is visually unrecognizable due to its small dimensions when viewing the motif layer without tools. With a strong magnifying glass or a microscope, the hidden information can be made visible and used to authenticate the security element.

In the 9 shown support structure designs are particularly well suited for use with cylindrical lenses whose axis is parallel to the direction 90 runs. The parallel bars 92 have a width of 0.1 to 5 .mu.m to each other at intervals of 10 to 30 microns. The bridges 92 run perpendicular to the axis 90 the cylindrical lenses and thus in a division of the motif layer in parallel stripes 28A . 28B ( 2 ) also perpendicular to the strip extension.

Optionally, in the parallel webs hidden information 94 such as the logo "G + D" shown, which is visually invisible due to its small size without tools, but can be made visible with a strong magnifying glass or a microscope for authentication.

In an alternative design are as support structures short support webs 96 provided, all perpendicular to the axis 90 The cylindrical lenses run, and their position varies irregularly, as in the lower half of the 9 shown.

The height of the support structures preferably corresponds to the depth of the recesses, but it may also be chosen smaller or larger. It is only essential that they prevent the adhesive layer of the acceptor film from being pressed through to the bottom of the recesses in the laminating process.

The foregoing is not intended to be construed as limiting the invention in any way to alternate images. Rather, the invention is generally applicable to display arrangements with a viewing element grid, in particular a lenticular grid.

So shows 10 an embodiment of a security element 100 with a representation arrangement in the form of a modulo magnification arrangement. It is on a carrier 102 , which is formed by a 19 micron thick transparent PET film, a UV embossing varnish applied, in which a parallelogram grid of spherical microlenses 104 is embossed with a diameter of about 20 microns. On the underside of the carrier 102 is a motif layer 106 with an embossed structure 108 arranged, their non-metallized surveys 118 and metallized wells 120 represent the imaged areas of a given target image. How the imaged areas of a modulo magnification arrangement can be determined from a predetermined target image is described in the publication WO 2009/000528 A1 described in detail. The relevant disclosure of the WO 2009/000528 A1 is included in the present description.

Depending on the motif of the given target image, the depressions can 120 contiguous mapped areas to an extended recessed area 110 complete. In order to avoid metallization errors, those well regions are in the illustrated embodiment 110 whose dimension exceeds 30 μm in one spatial direction, with supporting structures 92 in the form of cylindrical pillars ( 8th ) Mistake. The support structures 92 have in the embodiment of 10 each have a diameter of 1.5 .mu.m and are irregular in the recessed areas in an area ratio of about 3% 110 distributed. During the lamination process, the support structures prevent 92 reliable immersion of the adhesive layer 56 the acceptor foil 52 to the bottom of the specialization areas 110 , The motif layer created after laminating and separating windings 106 was covered with a full-surface layer of paint 112 and a full-surface metallization 114 Mistake. The reference number 116 denotes further layers of the construction of the security element, for example primer, opaque white or heat-sealable layers.

Due to their small size and their irregular arrangement, the support structures are 92 or at the location of the support structures in the wells 110 missing metallization when viewed with the grid of spherical microlenses visually unrecognizable.

In further embodiments, not shown here, the embossed structure of the donor sheet 20 be additionally provided in the wells with a further, finer structuring. Such structuring is formed, for example, by diffractive microrelief structures carrying holographic information. Of course, other structures, such as structures with matting or scattering effect, sub-wavelength gratings or nanostructures, in particular moth-eye structures, are possible.

LIST OF REFERENCE NUMBERS

10

bill

12

transfer element

14A, 14B

target images

16A, 16B

metallic parts

18A, 18B

non-metallic parts

20

security element

22

carrier

24

cylindrical lenses

26

motif layer

28A, 28B

strip

30A, 30B

viewing directions

32

more layers

40

embossing layer

42

surveys

44

wells

46

metallization

48

full-surface metal coating

50

donor sheet

52

Akzeptorfolie

54

transparent film

56

adhesive layer

58

transferred metal coating parts

60

Area of the motif layer

62

large areas of specialization

64

Metallisierungsfehler

70

support structures

72

focus areas

80

buttress

82

supporting webs

84

web structures

86

web elements

88

hidden information

90

Direction of the cylindrical lens axes

92

parallel bars

94

hidden information

96

short support bars

100

security element

102

carrier

104

spherical microlenses

106

motif layer

108

embossed structure

110

extended well area

112

coat of paint

114

metallization

116

more layers

118

surveys

120

wells

QUOTES INCLUDE IN THE DESCRIPTION

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

Cited patent literature

• WO 2009/000528 A1 [0024, 0075, 0075]

Cited non-patent literature

• "The moire magnifier", MC Hutley, R. Hunt, RF Stevens and P. Savander, Pure Appl. Opt. 3 (1994), pp. 133-142 [0004]

Claims (23)

Security element for securing security papers, documents of value and other data carriers, having a representation arrangement for displaying one or more target images whose motifs are each formed by visually recognizable, contrasting metallic and non-metallic subregions, wherein the representation arrangement comprises a motif layer having a plurality of metallized image elements and non-metallized picture elements and a viewing grid spaced from the motif layer of a plurality of viewing elements, and the metallized picture elements and the non-metallized picture elements when viewed with the viewing grid produce the visually recognizable, contrasting metallic and non-metallic portions of the target images, characterized in that the motif layer comprises an embossed structure with elevations and depressions, wherein the non-metallized picture elements of the motif layer are formed by non-metallized elevations tions of the embossed structure are formed and the metallic picture elements are formed by substantially metallized recesses of the embossed structure, and that at least a portion of the substantially metallized depressions in an area ratio between 0.1% and 25% contains small, raised support structures, which when viewed with the viewing grid are not visible visually. A security element according to claim 1, characterized in that at least a portion of the substantially metallized depressions contains the support structures in an area ratio between 2.5% and 10%. Security element according to claim 1 or 2, characterized in that the support structures are distributed irregularly in the recesses. A security element according to at least one of claims 1 to 3, characterized in that the height of the support structures corresponds to the depth of the recesses in which they are arranged. A security element according to at least one of claims 1 to 4, characterized in that the support structures comprise pillars of circular, oval, triangular, rectangular or polygonal cross-section, in which the cross-section of the pillars preferably has an area between 0.25 μm ² and 25 μm ² , A security element according to at least one of claims 1 to 5, characterized in that the support structures comprise irregularly extending continuous web structures, in which the width of the web structures is preferably between 0.1 μm and 5 μm. Security element according to at least one of claims 1 to 6, characterized in that the support structures comprise non-contiguous web elements, each consisting of one or more line pieces and whose width is preferably between 0.1 microns and 5 microns. A security element according to at least one of claims 1 to 7, characterized in that the support structures comprise straight, parallel web elements whose width is preferably between 0.1 μm and 5 μm. Security element according to at least one of Claims 1 to 8, characterized in that the support structures in a subarea contain hidden information in the form of characters or an encoding. Security element according to at least one of claims 1 to 9, characterized in that the viewing elements are formed by spherical lenses, aspheric lenses, cylindrical lenses or one or two-dimensionally focusing micro-cavity mirror. Security element according to at least one of claims 1 to 9, characterized in that the viewing elements are formed by cylindrical lenses and the support structures are formed by parallel, straight web elements, which are at an angle between 60 ° and 120 °, preferably between 85 ° and 95 ° , Particularly preferred extend from 90 ° to the axis of the cylindrical lenses. A security element according to at least one of claims 1 to 11, characterized in that the representation arrangement is a change picture, a motion picture, a pump picture, a morph picture or a stereo picture. A security element according to at least one of claims 1 to 11, characterized in that the representation arrangement is a micro-optical representation arrangement, in particular a moire magnification arrangement, a moiré-type magnification arrangement or a modulo magnification arrangement. Security element according to at least one of claims 1 to 13, characterized in that in the recesses of the embossed structure, an additional structuring, preferably a diffractive structure, a structure with a matting or scattering effect and / or a nanostructuring, is introduced. A security element according to at least one of claims 1 to 14, characterized in that the motif layer is provided over the whole or partial area with at least one printing ink and / or with at least one reflective coating material, preferably a metal, a color-shifting system, a high refractive index material, metal pigments or effect pigments. Data carrier with a security element according to one of claims 1 to 15. Method for producing a security element having a representation arrangement for displaying one or more target images whose motifs are each formed by visually recognizable, contrasting metallic and non-metallic subregions, having the following method steps: (a) preparing a donor sheet (i) forming an embossed structure with protrusions and depressions and with raised support structures arranged in the depressions in an area proportion between 0.1% and 25%, at least in a partial area of a main area of a first foil material or in a noticeable layer on at least a partial area of a main area a first sheet material, wherein the elevations and the recesses generate picture elements of a motif layer of the representation arrangement, which generate visually recognizable, contrasting metallic and non-metallic parts of the set images when the motif layer is viewed with a viewing grid of the presentation arrangement, (ii) applying a metal coating to at least a portion of the embossed structure, (b) producing an acceptor film by applying an adhesive layer to at least a portion of a major surface of a second film material, (c) laminating the donor film and the acceptor film by means of the adhesive layer in such a way that at least a partial region of the coated embossed structure and a partial region of the adhesive layer come into contact with one another, wherein in the contact region the metal coating adheres to the elevations of the embossed structure with the adhesive layer of the acceptor film, (d1) transferring the metal coating present in the contact region on the elevations of the donor film to the adhesive layer of the acceptor film by separating donor film and acceptor film, whereby a motif layer having a plurality of metallized picture elements and non-metallized picture elements is formed from the donor film, and (e1) producing a representation arrangement by combining the motif layer of the donor sheet with a viewing grid of a plurality of viewing elements such that the metallized picture elements and the non-metallized picture elements, when viewed with the viewing grid, form the visually recognizable, contrasting metallic and non-metallic portions of the target images produce. A method according to claim 17, characterized in that before or after step (a) (i) the viewing elements are embossed in the major surface of the first sheet material opposite the major surface of the first sheet material or in an embossable layer on the further major surface of the first sheet material opposite the principal surface , Method according to claim 17 or 18, characterized in that in step (a) an additional patterning, preferably a diffractive structure, a structure having a matting or scattering effect and / or a nanostructuring, is introduced into the recess lines of the embossing pattern. Method for producing a security element having a representation arrangement for displaying one or more target images whose motifs are each formed by visually recognizable, contrasting metallic and non-metallic subregions, comprising the following process steps: (a) producing a donor film by (i) forming an embossed structure Elevations and depressions and with in the depressions in an area ratio between 0.1% and 25% arranged raised support structures, at least in a portion of a main surface of a first sheet material or in an embossable layer on at least a portion of a major surface of a first sheet material, wherein the elevations and the recesses generate picture elements of a motif layer of the representation arrangement which, when viewing the motif layer with a viewing grid of the presentation arrangement, visually discernible, contrasting metallic and non-metallic subregions of the target image (ii) applying a metal coating to at least a portion of the embossed structure, (b) preparing an acceptor film by applying an adhesive layer to at least a portion of a major surface of a second film material, (c) laminating the donor film and the acceptor film by means of the adhesive layer, in that at least a partial region of the coated embossed structure and a partial region of the adhesive layer come into contact, wherein in the contact region the metal coating adheres to the elevations of the embossed structure with the adhesive layer of the acceptor film, (d2) transferring the metal coating present in the contact region on the elevations of the donor film the adhesive layer of the acceptor film by separating the donor sheet and the acceptor sheet, whereby a motif layer having a plurality of metallized picture elements and non-metallized picture elements is formed from the acceptor sheet, and (e2) producing a display arrangement by combining the motif layer of the acceptor sheet with a viewing grid of a plurality of viewing elements such that when viewed with the viewing grid, the metallized picture elements and the non-metallized picture elements produce the visually recognizable, contrasting metallic and non-metallic portions of the target images. Method according to at least one of claims 17 to 20, characterized in that in step (d1) or in step (d2) the metal coating present in the contact area on the raised support structures of the donor sheet is transferred to the adhesive layer of the acceptor sheet by separating donor sheet and acceptor sheet , Method according to at least one of claims 17 to 21, characterized in that prior to step (a) (ii) an adhesion-reducing treatment of the embossed structure is carried out in at least a partial area of the embossed structure. A method according to at least one of claims 17 to 22, characterized in that after step (d1) or after step (d2), the motif layer over the whole or partial area with at least one printing ink and / or at least one reflective coating material, preferably a metal, a color-shifting system , a high refractive index material, metal pigments or effect pigments.

Images