EP3305541A1 - Security element and valuable document with this security element - Google Patents

Abstract

A document of value (201, 202) with a security element (100, 101, 102) and a security element in the form of a strip with a first polymer layer (2) having at least one embossed diffraction structure (3) with at least one reflection layer are shown (4), which cooperates optically with the diffraction structure (3) to form a reflection hologram (5) as the first visually recognizable security feature, and with at least one luminescent under UV radiation imprint (6), the second under UV light visually recognizable security feature is formed, wherein the reflection hologram (5) has at least one see-through area (8) on the second security feature. In order to increase the security against forgery of the security element, it is proposed that the luminescent imprint (6) has a halftone printed image (60) and that the see-through area (8) through at least one recess (7) in the reflection layer (4) and by, in this Region of the recess (7) at least over the raster print image (60) of the imprint (6) of the diffraction structure (3) free polymer layer (2) is formed.

Description

The invention relates to a security element in the form of a strip having a first polymeric layer which has at least one embossed diffraction structure, with at least one reflection layer which interacts optically with the diffraction structure to form a reflection hologram as the first visually recognizable security feature, and with at least one sub UV element. Radiation luminescent imprint, which forms a second under UV light visually recognizable security feature, wherein the reflection hologram has at least one see-through area on the second security feature.

In order to be able to supplement a reflection hologram with a second security feature, it is known from the prior art ( EP 1 241 022 A1 ) Security elements are known, which can shine through a luminescent under UV radiation with a partially transparent reflection layer on the reflection holgram. The reflection holgram thus has a see-through area on the luminescent under UV radiation imprint, which increases the security against counterfeiting of the security element. Disadvantageously, both security features, namely reflection gramogram and imprint, visually impair what makes the optical separability of the security features more difficult and can lead to reduced security against counterfeiting.

The object of the invention is to increase the security against forgery of a security element having at least two security features.

The invention solves this problem by the fact that the luminescent imprint has a raster print image and that the see-through range by at least a recess in the reflection layer and by the, in this region of the recess at least over the halftone printed image of the imprint of the diffraction structure free polymeric layer is formed.

If the luminescent imprint has a raster print image, a security feature that is highly secure against counterfeiting can first be created on the security element. However, in order not to impair this increased safety by optical disturbances, for example moiré patterns, the invention further proposes that the see-through area is defined by at least one cut-out in the reflection layer and by, in this area of the cut-out, at least over the halftone printed image of the imprint of FIG the diffraction structure free polymer layer is formed. As a result, for example, the isotropic fluorescence radiation of the luminescent halftone printed image, which is particularly susceptible to diffraction-related distortions, pass through the transmission range in the reflection hologram almost unimpaired, so that no blurring in the image of the visual effect of the second security element is to be expected. In addition, a visual mixing of the two security elements can thus be avoided, which can promote undisturbed visual distinctness of the two security features.
In addition, a spatial depth effect between the two security features on the security element can be enhanced by this see-through range and thus the security against forgery of the security element can be further increased.

In general, it is mentioned that the term halftone print image can be understood to mean a printed image with a print pattern in which the halftone dots or printing dots can be applied next to and above one another. By color mixing and / or intensity variation, an image effect can be generated. Raster print images can represent single or multi-color images.
In general, it is further mentioned that for this luminescent under UV radiation printing, for example, a printing ink can be used which contains luminescent dyes or pigments. This luminescent dye and / or pigment can, for example, be brought into an energetically excited state under the action of radiation and then spontaneously pass into a state of lower energy, emitting photons of a specific wavelength, which can be perceived by the human eye at the appropriate wavelength.
In general, it is further noted that the luminescent imprint and / or the halftone image can be printed by any conventional, for example, contact or non-contact printing method, such as gravure, screen, pad, offset, lithographic, flexographic, high-pressure or inkjet. Printing method, etc. can be applied.

The visual boundary between the reflection hologram and the luminescent print under UV radiation can be further enhanced if the embossed diffraction structure ends at the recess of the reflection layer. In addition, depending on the viewing angle on the viewing area, a visual effect that is more or less dependent on the diffraction structure can thus be generated, with which the security element can be supplemented with a further security feature. In addition, it can further enhance the spatial depth effect. The security against counterfeiting of the security feature can thus be further improved.

The risk of visual angle-dependent, optical disturbances on the screen printing can be significantly reduced if the diffraction structure and reflection layer are arranged in register with each other.

If the recess and the raster print image are arranged in register relative to one another, it can first be avoided that motif components of the imprint are covered by the reflection layer of the reflection hologram. Furthermore, it can be achieved that, when the security element is viewed from the imprint side, the visual impression of the halftone printed image remains unimpaired by the reflective layer. In addition, a visual lifting of the luminescent halftone image of other areas in the see-through area under white light or Daylight, be reduced - for example, by avoiding opacity differences in the see-through range. In the see-through range, the luminescent print can thus be difficult to identify as such when viewed under white light or remain more stable in the security element. This can further increase the security against forgery of the security element.

The structural design of the security element can be simplified if the recess in the reflection layer at least partially covers the luminescent imprint. Thus, for example, the reflective layer can cover the printing edge and possibly hide disturbing edge effects on the raster printed image on the security element.

The security against counterfeiting can additionally be increased if the recess is provided in the form of a character, pattern or coding in the reflection layer. Thus, among other things, for example, the outer contour of the recess can be adapted to motifs in the luminescent print.

The invention may be particularly distinguished when the reflection hologram has a motif and the recesses forms a motif part of the reflection hologram. For example, the recesses can correspond to inverted contours of the subject and complete this by the luminescent imprint under UV irradiation. This can further increase the security against forgery of the security element.

In general, it is further mentioned that an imprint on the reflection layer can be provided outside the recesses in the reflection hologram - and may be desirable. Such an imprint would be inaccessible to viewing from the side of the imprinted polymeric layer. When viewed from the imprint side, however, this can represent an additional security feature.

If the raster print image has differently colored luminescent screen dots, a multicolor luminescent print can be created. This multi-color luminescent imprint can even be formed true-color when red, green and blue luminescent halftone dots are used.

A particularly tamper-proof security feature on the luminescent imprint can be created if the raster print image has a honeycomb grid whose hexagonal raster cells consist of juxtaposed triangular raster points.

The raster print image preferably has raster cells with a size of 10 to 500 μm, in particular of 50 to 200 μm.

If the security element has a transparent topcoat layer, the luminescent imprint can be reliably protected against external influences. In particular, this can prevent oxidation of the fluorescent dyes. Furthermore, the security element can be protected against mechanical damage of the reflection hologram or against oxidation of the metallic reflection layer. According to the invention, such a particularly robust and stable security element can be created.
If this transparent topcoat layer is an adhesive layer, then the security element can be protected against external influences and at the same time be provided on a valuable document or on any desired carrier in a manner that is easy to handle. It is also conceivable that the adhesive layer is applied to an additional transparent topcoat layer.
In particular, the adhesive layer may be a heat sealing lacquer layer, a cold seal adhesive layer, a self-adhesive coating, a radiation-curing coating or other comparable coatings.

The handling of the security element can be facilitated if the security element has a carrier film and can thus experience increased mechanical stability.
Preferably, the carrier film may also be designed as a transfer carrier to facilitate the handling of the security element in its further use in addition.

The security element according to the invention can develop its advantages in particular if it is applied to a substrate of a value document and is connected to it in a material-locking manner. As a document of value, for example, a banknote, a tax stamp, a passport, driver's license or identity card are conceivable.

In general, it is noted that the substrate may also include one or more windows for viewing the security element, thereby providing a valuable document with very high security against forgery.

The security against forgery of the value document can be further improved if the luminescent imprint is visually adapted to the visual appearance of the substrate. Thus, for example, a visually recognizable difference in opacity between the substrate and the luminescent imprint can be avoided, which can hide it stably in the document of value when viewed under white light.

If the security element has a transparent cover film, then a robust security element can be created which is suitable for embedding in a document of value and has different visually recognizable security features viewed from both sides.

If the security element is embedded in the substrate of the value document and the substrate has at least one window for viewing the security element, then a particularly forgery-proof document of value can be created. The Namely, embedded security element can then be viewed in particular from at least one or both sides of the substrate and can have different visually recognizable security features on each side in the case of a double-sided window.

In general, it is stated that the windows in the value document can be arranged in register with the security features on the security element.

Fig. 1

eine Querschnittsansicht durch eine Ausführungsart des erfindungsgemäßen Sicherheitselements,

Fig. 2

eine Querschnittsansicht durch ein Wertdokument mit einer weiteren Ausführungsart des Sicherheitselements,

Fig. 3

eine Querschnittsansicht durch ein weiteres Wertdokument mit einer dritten Ausführungsart des Sicherheitselements, und

Fig. 4

eine Draufsicht auf ein erfindungsgemäßes Sicherheitselement mit einer Detailansicht.

In the figures, for example, the subject invention is illustrated in more detail with reference to a variant embodiment. Show it

Fig. 1

a cross-sectional view through an embodiment of the security element according to the invention,

Fig. 2

a cross-sectional view through a value document with a further embodiment of the security element,

Fig. 3

a cross-sectional view through another document of value with a third embodiment of the security element, and

Fig. 4

a plan view of a security element according to the invention with a detailed view.

According to Fig. 1 a security element 100 is shown, on which a polymeric layer 2, in particular a polymerized lacquer layer, is provided. In the polymeric layer 2, a diffraction structure 3 is embossed, which diffraction structure 3, in cooperation with a reflection layer 4 provided on the polymeric layer 2, forms a reflection hologram 5, which represents the first security feature of the security element 100. Furthermore, a print 6 is attached, which luminesces under irradiation with UV light. In particular, the imprint 6 contains luminescent dyes for this purpose. Over the imprint 6 4 recesses 7 are provided in the reflective layer.

According to the invention, maximum security is achieved at the security element 100, in which the see-through area 8 is defined by at least one recess 7 in the reflection layer 4 and by the, in this area of the recess 7 of the Diffraction structure 3 free polymer layer 2 is formed. For only in this way is it possible to be able to perceive a luminescent printing 6 with a halftone printed image 60 which has an isotropic fluorescence radiation free of distortions. For this purpose, the recess 7 is provided at least over the halftone printing image 60 of the imprint 6, as after Fig. 4 can be recognized. An unrestricted viewing of the halftone printing image 60 is ensured. Accordingly, the security element 100 can be viewed both from the side of the carrier foil 1 and from the side of the imprint 6, whereby a security element 100 with high security against forgery is created.

In Fig. 1 can be further recognized that the embossed in the polymeric layer 2 diffraction structure 3 at the recess 7 of the reflective layer 4 ends. In addition, no diffraction structures 3 are introduced into the see-through regions 8 in the first polymer layer 2, as a result of which unhindered viewing, or an unchanged visual impression of the imprint 6 - even in the edge region - can be achieved. Thus, it can be prevented that a visual superimposition between diffraction structure 3 and luminescent imprint 6 takes place in the edge regions of the viewing regions 8. In addition, the imprint 6 with the see-through region 8 or with the recess 7 in the reflection layer 5 in the register. For this purpose, diffraction structure 3 and reflection layer 4 are advantageously also arranged in register with one another. However, the boundary contour 9 of the reflection layer 4 can also easily cover the boundary contour 10 of the halftone printed image 60-the halftone image 60 thus extending beyond the reflection structure 3 at least slightly beyond the reflection layer 4. This leads to a sharp boundary contour between the luminescent imprint 6 and the reflection hologram 5. Likewise, as in FIG Fig. 2 illustrated - possible that the boundary contour 10 of the raster print image 60 is not covered by the boundary contour of the reflection layer 4, but in the region of the recess 7 is located. In this way, optical impairments to the visual perceptibility of the halftone printing image 60 can be prevented.

How the particular Fig. 4 can be seen, the halftone printing image 60 different color, namely in red, green and blue, luminescent halftone dots 61, 62, 63 on. In addition, the raster print image 60 has a honeycomb grid 64 whose hexagonal raster cells 65 consist of juxtaposed triangular raster dots 61, 62, 63. These grid cells 65 have a size of 10 to 500 .mu.m, in particular from 50 to 200 .mu.m.

In addition, the boundary contour 9 of the recess 7 in the reflection layer 4 can follow the form of a character, a pattern or a coding. However, it may turn out to be particularly advantageous if the boundary contour 9 of the recess follows or completes a motif generated by the reflection hologram 5. For example, different subject parts can be recognized under different lighting situations.

Advantageously, the imprint 6 is covered by a transparent topcoat layer 11, as shown in FIG Fig. 1 is shown. The topcoat layer 11 may be designed as a transparent protective lacquer 11, or serve as an adhesive layer 11, in particular as a heat sealing lacquer layer 11. It is also conceivable that both transparent protective lacquer and adhesive layer form the topcoat layer 11. Via the adhesive layer 11, security elements 100, 101, 102 according to the invention can be provided on value documents 201, 202, as shown in FIG Fig. 2 and Fig. 3 is shown.

On the adhesive layer 11 of the security element 100, 101, 102 also a transparent cover sheet 12 may be attached, as for example from the in Fig. 3 shown security element 102 can be detected.

In a further embodiment, the polymeric lacquer layer 2 is advantageously adhesively attached to a carrier film 1. Such a carrier film 1 can facilitate both the manufacturing process of the security element 100, 101, 102, as also improve its stability. Alternatively, the carrier film 1, or the transfer carrier 1, be provided again removable from the polymeric coating layer 2.

In Fig. 2 and Fig. 3 Value documents 201, 202 are shown, wherein a security element 101 or 102 is respectively applied to the value documents 201, 202. According to the invention, the value documents 201, 202 may in particular be a banknote, a driver's license, an identity card, a passport or comparable documents.

In Fig. 2 a document of value 201 is shown, wherein the carrier film 1 (cf. Fig. 1 ) was removed. The security element 101 was adhesively bonded to the substrate 13 of the document of value 201 via the adhesive layer 11. The luminescent imprint 6 is visually adapted to the visual appearance of the substrate 13 of the value document 201.

This in Fig. 3 shown value document 202 has a security element 102 on which a transparent cover sheet 12 has been applied. The security element 102 is embedded between an upper substrate 14 and a lower substrate 15. Both the upper substrate 14 and the lower substrate 15 have windows 16 to at least partially allow a direct view of the security features of the security element 102. Between security element 102 and the substrates 14, 15 of the document of value 202, an additional adhesive layer 17, in particular a heat sealing lacquer layer, is provided in each case, which are likewise recessed in the region of the windows 16. The carrier film 1 and the transparent cover film 12 of the security element 102 can also be designed to be printable. It is thus conceivable that in each case a pressure 18, with or without luminescent dyes, is provided on the carrier film 1 and cover film 12. In a further embodiment of the invention, only one of the substrates 13, 14 has a window 16, which has not been shown in detail in the figures.

In addition, in another embodiment, a value document is provided which has a security element 100, 101, 102 according to the invention, which is applied to a single substrate 13, the substrate 13 having a window for viewing the security element 100, 101, 102, which is shown in FIG However, the figures were not shown in detail. Such a security element can thus be viewed from two sides and thus increase the security against counterfeiting.

Claims (15)

A security element in the form of a strip having a first polymeric layer (2) having at least one embossed diffraction structure (3) with at least one reflection layer (4) optically co-operating with the diffraction structure (3), a reflection hologram (5) first visually recognizable security feature form, and with at least one under UV radiation luminescent imprint (6) forming a second under UV light visually recognizable security feature, wherein the reflection hologram (5) has at least one see-through area (8) on the second security feature, characterized in that the luminescent imprint (6) has a halftone printed image (60) and in that the see-through area (8) extends through at least one cutout (7) in the reflection layer (4) and through the area in which the cutout (7) at least over the halftone printed image (60) of the imprint (6) of the diffraction structure (3) free polymeric layer (2) is formed. Security element according to claim 1, characterized in that the diffraction structure (3) and reflection layer (4) are arranged in register with each other. A security element according to claim 1 or 2, characterized in that the recess (7) and the halftone printed image (60) are arranged in register with each other. A security element according to claim 1, 2 or 3, characterized in that the reflection layer (4) at least partially covers the boundary contour (10) of the halftone printed image (60). Security element according to one of claims 1 to 4, characterized in that the recess (7) in the form of a character, pattern or a coding in the reflection layer (4) is provided. Security element according to one of claims 1 to 5, characterized in that the reflection hologram (5) has a motif and the recesses (7) forms a motif part of the reflection hologram (5). Security element according to one of claims 1 to 6, characterized in that to form a multicolor luminescent imprint (6) the halftone printed image (60) has different color, in particular red, green and / or blue, luminescent screen dots (61, 62, 63). A security element according to claim 7, characterized in that the raster print image (60) has a honeycomb grid (64) whose hexagonal raster cells (65) are arranged side by side, in particular adjacent, triangular grid points (61, 62, 63). Security element according to one of claims 7 to 8, characterized in that the raster print image (60) raster cells (65) having a size of 10 to 500 .mu.m, in particular from 50 to 200 .mu.m. Security element according to one of claims 1 to 9, characterized in that the security element (100, 101, 102) has a transparent topcoat layer (11), in particular an adhesive layer (11). Security element according to one of claims 1 to 10, characterized in that the security element (100, 101, 102) has a transparent cover film (12). Security element according to one of claims 1 to 11, characterized in that the security element (100, 101, 102), in particular designed as a transfer carrier, carrier film (1). Value document with a substrate (13) and with at least one on the substrate (13) provided security element (100, 101, 102) according to one of claims 1 to 12. Value document according to claim 13, characterized in that the luminescent imprint (6) is visually adapted to the visual appearance of the substrate (13). Value document according to claim 13 or 14, characterized in that the security element (100, 101, 102) in the substrate (14, 15) is embedded and the substrate (14, 15) at least one window (16) for viewing on the security element (100 , 101, 102).

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