EP3305541B1 - Security element and valuable document with this security element - Google Patents

Description

The invention relates to a security element in the form of a strip with 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 under UV Radiation-luminescent imprint that forms a second security feature that is visually recognizable under UV light, wherein the reflection hologram has at least one viewing area on the second security feature.

In order to be able to supplement a reflection hologram with a second security feature, the state of the art ( EP 1 241 022 A1 ) Security elements are known which, with a partially transparent reflection layer on the reflection hologram, can show an imprint luminescent under UV radiation. The reflection hologram thus has a see-through area on the print luminescent under UV radiation, which increases the security of the security element against forgery. Both security features, namely reflection hologram and imprint, have a disadvantageous visual impact, which makes it difficult to visually separate the security features and can lead to reduced counterfeit security.

document DE 10 2004 053 007 A1 discloses a security element in the form of a strip with a first 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 luminescent print that has a second forms a visually recognizable security feature, the reflection hologram having at least one see-through area on the second security feature, the see-through area being formed by at least one recess in the reflection layer and by the first layer.

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

The invention solves this problem by the subject matter of claim 1.

If the luminescent print has a raster print image, a security feature that is highly forgery-proof can first be created on the security element. In order not to impair this increased security by optical disturbances, for example a moiré pattern, the invention further proposes that the see-through area be provided with at least one recess in the reflective layer and through the, in this region of the recess at least above the raster print image of the imprint of the diffraction structure free polymer layer is formed. As a result, for example, the isotropic fluorescence radiation of the luminescent raster print image, which is particularly susceptible to diffraction-related distortions, can pass through the viewing area in the reflection hologram almost unaffected, so that blurring in the visual effect of the second security element is not to be expected. In addition, a visual mixing of the two security elements can be avoided, which can promote an unimpaired visual differentiation of the two security features.

In addition, this viewing area can intensify a spatial depth effect between the two security features on the security element and thus further increase the security against forgery of the security element.

In general, it is mentioned that a raster print image can be understood to mean a printed image with a print raster in which the raster dots or printing dots can be applied next to and on top of one another. An image effect can be generated by a color mixture and / or intensity variation. Raster printed images can represent single or multi-colored images.

In general, it is further mentioned that, for this printing which is luminescent under UV radiation, it is possible, for example, to use a printing ink 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 change into a state of lower energy, whereby photons of a certain wavelength are emitted, which can be perceived by the human eye at a corresponding wavelength.
In general, it is further stated that the luminescent imprint and / or the raster print image is carried out using any conventional, for example contact or non-contact, printing method, such as gravure, screen printing, pad printing, offset printing, lithography printing, flexographic printing, high pressure or inkjet printing. Printing process, etc. can be applied.

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

The risk of optical disturbances dependent on the angle of view on the raster print can be significantly reduced if the diffraction structure and reflection layer are arranged in register with one another.

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

The design of the security element can be simplified if the recess in the reflection layer covers the luminescent print at least in some areas. For example, the reflective layer can cover the print edge and possibly hide edge effects on the raster print image that interfere with the security element.

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

The invention can be particularly distinguished if the reflection hologram has a motif and the recesses form a motif part of the reflection hologram. For example, the cutouts may correspond to inverted contours of the motif and complete it with the luminescent print under UV radiation. This can further increase the security of the security element against forgery.

In general, it is further mentioned that an imprint on the reflection layer outside the recesses in the reflection hologram can be provided - and may be desired. Such an imprint would not be viewable from the side of the embossed polymer layer. When viewed from the printed side, this can represent an additional security feature.

If the raster print image has luminescent dots with different colors, a multicolored luminescent print can be created. This multicolored luminescent print can even be of real color if red, green and blue luminescent halftone dots are used.

A particularly forgery-proof security feature on the luminescent imprint can be created if the raster print image has a honeycomb raster whose hexagonal raster cells consist of triangular raster dots arranged next to one another.

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

The manageability of the security element can be made easier if the security element has a carrier film and can thus experience increased mechanical stability.
The carrier film can preferably also be designed as a transfer carrier in order to additionally facilitate the handling of the security element when it is used further.

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 integrally connected to it. A banknote, a tax stamp, a passport, driver's license or ID card can be used as a value document.

In general, it is stated that the substrate can also have one or more windows for looking through the security element, as a result of which a document of value with a very high level of security against forgery can be created.

The security against forgery of the value document can be further improved if the luminescent print is visually adapted to the optical appearance of the substrate. In this way, for example, a visually recognizable difference in opacity between the substrate and the luminescent imprint can be avoided, which can be hidden in the document of value when viewed under white light.

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

If the security element is embedded in the substrate of the document of value and the substrate has at least one window for viewing the security element, a particularly forgery-proof document of value can be created. The embedded security element can then in particular be viewed from at least one or from both sides of the substrate and, in the case of a window on both sides, can have different visually recognizable security features on each side.
In general, it is stated that the windows in the document of value 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 of the invention is shown in more detail using an embodiment variant. Show it

Fig. 1

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

Fig. 2

2 shows a cross-sectional view through a document of value 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. A diffraction structure 3 is embossed in the polymeric layer 2, which diffraction structure 3, in interaction with a reflection layer 4 provided on the polymer layer 2, forms a reflection hologram 5, which represents the first security feature of the security element 100. Furthermore, an imprint 6 is attached, which luminesces under irradiation with UV light. In particular, the print 6 contains luminescent dyes for this purpose. Recesses 7 are provided in the reflection layer 4 above the imprint 6.

According to the invention, the highest level of security is achieved on the security element 100 in that the see-through area 8 through at least one recess 7 in the reflection layer 4 and through that in this area of the recess 7 from the Diffraction structure 3 free polymer layer 2 is formed. This is the only way to be able to perceive a luminescent print 6 with a raster print image 60, which has an isotropic fluorescent radiation, free of distortions. For this purpose, the recess 7 is provided at least above the raster print image 60 of the print 6, as shown in FIG Fig. 4 can be recognized. An unrestricted viewing of the raster print image 60 is thus guaranteed. The security element 100 can accordingly be viewed both from the side of the carrier film 1 and from the side of the imprint 6, as a result of which a security element 100 with high security against forgery is created.

In Fig. 1 can further be seen that the diffraction structure 3 impressed into the polymer layer 2 ends at the recess 7 of the reflection layer 4. In addition, no diffraction structures 3 are introduced in the see-through areas 8 in the first polymeric layer 2, as a result of which an unimpeded viewing, or an unchanged visual impression of the imprint 6 - also in the edge area - can be achieved. This can prevent a visual overlay between the diffraction structure 3 and the luminescent print 6 from occurring in the edge regions of the see-through regions 8. In addition, the imprint 6 with the see-through area 8 or with the recess 7 in the reflection layer 5 is in register. For this purpose, diffraction structure 3 and reflection layer 4 are also advantageously arranged in register with one another. However, the boundary contour 9 of the reflection layer 4 can also slightly cover the boundary contour 10 of the raster print image 60 - the raster print image 60 thus extend minimally beyond the reflection layer 4 behind the diffraction structure 3. This leads to a sharp boundary contour between the luminescent imprint 6 and the reflection hologram 5. It is also - as in Fig. 2 shown - 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 lies in the region of the recess 7. In this way, optical impairments of the visual perceptibility of the raster print image 60 can be prevented.

Like especially the Fig. 4 can be seen, the halftone printed image 60 has luminescent halftone dots 61, 62, 63 of different colors, namely red, green and blue. This results in a true-color luminescent raster print image 60. In addition, the raster print image 60 has a honeycomb raster 64 whose hexagonal raster cells 65 consist of triangular raster points 61, 62, 63 arranged next to one another. These grid cells 65 have a size of 10 to 500 μm, in particular 50 to 200 μm.

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

The print 6 is advantageously covered by a transparent top coat layer 11, as shown in FIG Fig. 1 is shown. The top coat layer 11 can be designed as a transparent protective lacquer 11, or can serve as an adhesive layer 11, in particular as a heat seal lacquer layer 11. It is also conceivable that both the transparent protective lacquer and the adhesive layer form the top lacquer layer 11. Security elements 100, 101, 102 according to the invention can be provided on value documents 201, 202 via the adhesive layer 11, as shown in FIG Fig. 2 and Fig. 3 is shown.

A transparent cover film 12 can also be attached to the adhesive layer 11 of the security element 100, 101, 102, as shown, for example, in FIG Fig. 3 security element 102 shown can be recognized.

In a further embodiment, the polymeric lacquer layer 2 is advantageously adhered to a carrier film 1. Such a carrier film 1 can both facilitate the manufacturing process of the security element 100, 101, 102 and also improve its stability. Alternatively, the carrier film 1 or the transfer carrier 1 can again be provided such that it can be peeled off from the polymeric lacquer layer 2.

In Fig. 2 and Fig. 3 Value documents 201, 202 are shown, security elements 101 and 102 being applied to each of the value documents 201, 202. According to the invention, the value documents 201, 202 can in particular be a bank note, a driver's license, an identity card, a passport or comparable documents.

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

This in Fig. 3 The document of value 202 shown has a security element 102, on which a transparent cover film 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 in order to at least partially allow a direct view of the security features of the security element 102. Between the security element 102 and the substrates 14, 15 of the value document 202, an additional adhesive layer 17, in particular a heat seal lacquer layer, is provided, which are also recessed in the area of the window 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 conceivable that a print 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 was not shown in the figures, however. In addition, in a further embodiment, a document of value is created 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 looking through the security element 100, 101, 102, which is shown in 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 forgery.

Claims (15)

1. A security element in form of a strip having a first polymer layer (2) which comprises at least one embossed diffraction structure (3), at least one reflection layer (4) which optically interacts with the diffraction structure (3) in order to form a reflection hologram (5) as a first visually recognisable security feature, and at least one imprint (6) which is luminescent under UV radiation and which forms a second security feature that is recognisable under UV light, wherein the reflection hologram (5) comprises at least one see-through region (8) on the second security feature, wherein the luminescent imprint (6) comprises a halftone print image (60), and the see-through region (8) is formed by at least one recess (7) in the reflection layer (4) and by the polymer layer (2) which is free in this region of the recess (7) from the diffraction structure (3) at least above the halftone print image (60) of the imprint (6).
2. A security element according to claim 1, characterized in that the diffraction structure (3) and the reflection layer (4) are arranged in relation to each other in the register.
3. A security element according to claim 1 or 2, characterized in that the recess (7) and the halftone print image (60) are arranged in relation to each other in the register.
4. A security element according to claim 1, 2 or 3, characterized in that the reflection layer (4) covers the boundary contour (10) of the halftone print image (60) at least in sections.
5. A security element according to one of the claims 1 to 4, characterized in that the recess (7) is provided in form of a character, pattern or coding in the reflection layer (4).
6. A security element according to one of the claims 1 to 5, characterized in that the reflection hologram (5) comprises a motif and the recesses (7) form a motif part of the reflection hologram (5).
7. A security element according to one of the claims 1 to 6, characterized in that for forming a multicolour luminescent imprint (6) the halftone print image (60) comprises halftone dots (61, 62, 63) which are luminescent with different colours, especially red, green and/or blue.
8. A security element according to claim 7, characterized in that the halftone print image (60) comprises a honeycomb grid (64), whose hexagonal grid cells (65) consist of triangular halftone dots (61, 62, 63) which are arranged adjacent to each other, especially bordering each other.
9. A security element according to one of the claims 7 to 8, characterized in that the halftone print image (60) comprises grid cells (65) with a size of 10 to 500 µm, especially 50 to 200 µm.
10. A security element according to one of the claims 1 to 9, characterized in that the security element (100, 101, 102) comprises a transparent topcoat layer (11), especially an adhesive layer (11).
11. A security element according to one of the claims 1 to 10, characterized in that the security element (100, 101, 102) comprises a transparent cover film (12).
12. A security element according to one of the claims 1 to 11, characterized in that the security element (100, 101, 102) comprises a carrier film (1), which is especially formed as a transfer carrier.
13. A value document with a substrate (13) and with at least one security element (100, 101, 102) according to one of the claims 1 to 12 provided on the substrate (13).
14. A value document according to claim 13, characterized in that the luminescent imprint (6) is visually adjusted to the visual appearance of the substrate (13).
15. A value document according to claim 13 or 14, characterized in that the security element (100, 101, 102) is embedded in the substrate (14, 15), and the substrate (14, 15) comprises at least one window (16) for looking through onto the security element (100, 101, 102).

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