EP1458577B1 - Security element and method for producing the same - Google Patents

Description

The invention relates to a security element for security papers, banknotes, identity cards or the like, as well as a security paper and a document of value with such a security element. Furthermore, the invention relates to methods for producing the security element or the security paper and the value document with such a security element, a transfer material for the production of such security elements and the use of a corresponding security element or security document or value document.

In the EP 0 330 733 A1 A security thread is proposed that is both visually and mechanically verifiable. For this purpose, a translucent plastic film is coated with metal and this coating provided with recesses in the form of characters or patterns. In addition, the security thread contains colorant and / or luminescent substances in the regions which coincide with the recesses, by means of which the characters or patterns differ in color contrasting from the opaque metal coating under suitable light conditions. As the metal layer, an aluminum layer is preferably used. This security thread is embedded as a so-called "window security thread" in security papers, ie it is virtually woven into the paper during the formation of sheets of security paper so that it is freely accessible at regular intervals on the surface of the paper and only in the intermediate areas embedded in the paper is.

This security thread already meets a very high security standard. The continuous metallic coating allows a mechanical verification of the electrical conductivity, while the recesses serve as a visual, for the viewer in transmission easily recognizable authenticity feature. In addition, the thread has an additional from the viewer not readily recognizable feature, namely the luminescence in the region of the recesses, which is also mechanically verifiable. However, when looking at banknotes having such a security thread, it is primarily the metallic gloss of the window areas that is striking. This gloss can be imitated by simply sticking on aluminum foil elements. In the case of a fugitive examination alone in incident light, counterfeits of this kind could therefore be considered genuine banknotes.

Out EP 0 400 902 A1 For example, a security paper for banknotes, checks and the like is known which has at least one elongate security element which is partially embedded in the paper. The security element is provided with at least two metal areas of different colors which can form repetitive patterns. In this case, a two-color pattern is produced such that selectively metallized regions are applied to one side of a carrier layer, while a continuous metal layer is provided on the other side of the carrier layer. Furthermore, two metal layers of different colors can also be arranged on the same side of a plastic layer.

The invention is therefore based on the object to propose a security element and a security paper and a document of value, which has an increased security against counterfeiting compared to the prior art.

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

According to the invention, the security element has at least two metal layers of different color, which are arranged side by side on the same surface of the security element and at least partially directly adjoin one another. The visual impression of such a security element can be imitated, if at all, only with great effort, in particular if the different-colored metal layers are applied in complicated patterns which may also be intertwined. Thus, for example, a multicolored metallic motif can be generated, which is composed of different colored metals. The metal layers are arranged on a plastic layer, which is part of the security element.

The metals may be, for example, aluminum, chromium, nickel, copper, gold, silver or other "non-ferrous metals" or colored metal alloys. Also metallic-looking compounds, such as the gold-colored titanium nitride can be used.

Another way to increase the security against counterfeiting is to use metals with different physical properties, in particular different magnetic or electrical properties. For example, iron and aluminum differ in both color and magnetic properties. This difference can be detected metrologically and therefore serves as a machine-authenticated authenticity feature.

The security against counterfeiting can be additionally increased if the metal layers have recesses in the form of alphanumeric characters, patterns, logos or the like.

The security element can be a security thread, which consists of a self-supporting plastic film, on which the different colored metal layers are applied. This security thread can be at least partially incorporated into a security paper or security document. However, it is also conceivable to form the security element band or label-like and to attach to the surface of the security paper or value document.

The plastic film of the security element can also be provided with diffraction structures in the form of a relief structure. The diffractive structures may be any diffractive optical structures such as holograms or grating structures (e.g., Kinegram®, pixelgrams) or the like.

Alternatively, the security element can also be designed as a transfer element. This variant is particularly advantageous if the security element is arranged completely on the surface of the security paper or value document. In this case, the layer structure of the security element is prepared on a carrier film, usually a plastic film and then transferred in a hot embossing process in the desired outline contours on the security paper or document of value.

Of course, in the case of this security element, too, a diffraction structure can be integrated into the layer structure of the security element. In addition, the security element can have further security features, such as a thin-layer structure, a printed image or the like.

If the security element is arranged on the surface of the security paper or value document, then it can have any outline structures, such as For example, have round, oval, star-shaped, rectangular, trapezoidal or strip-shaped outline contours.

According to a preferred embodiment, the security paper or security document to which the security element is applied has a through opening. The security element is in this case arranged in the region of the opening and projects beyond this on all sides. In this case, the security element of the front and the back is verifiable. The different metals are also recognizable from both sides and indeed absolutely "congruent". An imitation of the color effect is therefore particularly difficult or completely ruled out in this embodiment.

However, the use of the security element according to the invention is not limited to the field of security documents. The security element according to the invention can also be used advantageously in the field of product security for securing counterfeiting of any goods. For this purpose, the security element can have additional anti-theft elements, such as a coil or a chip. The same applies to the security paper or security document provided with such a security element.

The application of the metal layers is preferably carried out with a vacuum evaporation plant, wherein the individual metallic areas are respectively generated via masks. If more than two metal layers are used, individual ones of the metal layers can be produced by printing metal effect colors or metallic pigments. The production of the recesses in the respective metal layers is preferably carried out by means of a washing process, as described in US Pat WO 99/13157 is described. The security elements are thereby prepared as a security film, which has several benefits of the security element. The base material forms a self-supporting, preferably transparent plastic film. In the case of security threads or labels, this plastic film corresponds to the plastic layer of the security element according to the invention. If the security elements are removed from an embossing foil, then the plastic foil forms the carrier material of this transfer material onto which the plastic layer is applied, for example in the form of a lacquer layer. In this lacquer layer or, in the case of security threads or labels, in the plastic film diffraction structures can be embossed. The plastic layer of the security element according to the invention is preferably printed in gravure in the form of the later recesses. For this purpose, a printing ink is used with a high pigment content, which forms a porous, sublime color order. Subsequently, the different colored metal layers are optionally vapor-deposited with the aid of masks on the printed plastic layer. Finally, in a final step, the paint application and the overlying metal layer are removed by washing with a liquid, possibly combined with mechanical action. Preferably, a water-soluble ink is used so that water can be used as the liquid. Thus, this process is very environmentally friendly and requires no special protective measures. This method also has the advantage that the recesses for both or more metal layers are produced in one operation. The washout can be assisted by mechanical means such as a rotating roller, brush or ultrasound.

The use of etching techniques is much more complex, but in principle also possible. Here, the metal layers are first deposited on the plastic layer and then printed the entire surface except for the areas to be removed with a protective lacquer layer. The entire security element layer structure is then passed through an etching bath, in which the uncovered areas are detached from the plastic layer. If different etching baths are necessary for the different metals, the process of covering or immersing in an etching bath with different etching solutions must be repeated. Neutralization and cleaning baths must be provided between the individual etching baths, so that the chemicals of the individual baths are not contaminated.

Another possibility is to produce the recesses in the metal layers by electrodeposition by means of electrolysis. Here, too, the metal layers are first deposited on the plastic layer and then a passivation layer is printed in the remaining metallic areas. The security element layer structure is finally passed through an electrolytic bath in which the metal layer is used as the cathode. The electrolyte solution and voltage to be used must be adapted to the metals used. Again, it may be necessary to use different electrolyte solutions for the different metals. The principle of this method is known in the art and is described for example in the WO 00/02733 explained in more detail.

Other methods are also conceivable, such as, for example, mechanical removal of the metal layer areas or the generation of interruptions by means of a laser-beam recorder, electron-beam erosion or other removal methods.

Luminescent substances, liquid-crystalline substances, metallic printing inks or metal bronzes can be arranged in the metal-layer-free intermediate regions and serve as a further authenticity feature.

Further embodiments and advantages of the security element or security paper and value document according to the invention are explained with reference to the figures. The illustrations are schematized and do not correspond to the actual proportions and proportions.

Fig.1

ein erfindungsgemäßes Wertdokument,

Fig. 2

Querschnitt durch das erfindungsgemäße Wertdokument entlang der Linie A - A,

Fig. 3

ein erfindungsgemäßes Sicherheitselement in Aufsicht,

Fig. 4

Schichtaufbau einer Ausführungsform des in Fig. 3 gezeigten Sicherheitselements im Querschnitt,

Fig. 5

erfindungsgemäßes Transfermaterial im Querschnitt,

Fig. 6 a - c

Verfahren zur Herstellung eines erfindungsgemäßen Sicherheitselements,

Fig. 7

weitere Variante des Wertdokuments gemäß Fig.1 im Querschnitt entlang A - A,

Fig. 8

weitere Ausführungsform eines Sicherheitselements im Querschnitt,

Fig. 9

weitere Ausführungsform eines Sicherheitselements im Querschnitt,

Fig. 10

weitere Ausführungsform eines Sicherheitselements in Aufsicht,

Fig.11a, b

Verfahren zur Herstellung des Sicherheitselements gemäß Fig. 10,

Fig. 12a, b

Verfahren zur Herstellung eines Sicherheitselements,

Fig. 13

nach dem Verfahren gemäß Fig. 12 vorgestelltes Sicherheitselement in Aufsicht.

Show it:

Fig.1

a value document according to the invention,

Fig. 2

Cross section through the value document according to the invention along the line A - A,

Fig. 3

an inventive security element in supervision,

Fig. 4

Layer structure of an embodiment of the in Fig. 3 shown security elements in cross section,

Fig. 5

Cross-sectional transfer material according to the invention,

Fig. 6 a - c

Method for producing a security element according to the invention,

Fig. 7

another variant of the value document according to Fig.1 in cross-section along A - A,

Fig. 8

further embodiment of a security element in cross-section,

Fig. 9

further embodiment of a security element in cross-section,

Fig. 10

further embodiment of a security element in supervision,

Fig.11a, b

Method for producing the security element according to Fig. 10 .

Fig. 12a, b

Method for producing a security element,

Fig. 13

according to the method according to Fig. 12 presented security element in supervision.

Fig.1 shows an inventive document of value in supervision. In the example shown, it is a banknote 1. This banknote has a strip-shaped security element 2, which extends over the entire width of the banknote 1. The entire surface of the security element 2 facing the viewer is metallic, the areas 3, 4 being covered with differently colored metals which, in the example shown, each directly adjoin one another and are arranged alternately.

At the in Fig. 1 The illustrated security element is a diffraction-optical security element, which consists of an embossed plastic layer and at least one metallically reflecting layer.

Fig. 2 shows a cross section along the line A - A in Fig. 1 , Here, the plastic layer 5 can be seen, in which the diffraction structure 6 is introduced. Below this, the differently colored metal layers 3, 4 are arranged alternately directly adjacent to one another. In the example shown, the layers of the security element are attached to the document of value via an adhesive layer 30.

Fig. 3 shows a further embodiment of a security element according to the invention in a plan view. Here are in the various metallic areas 3, 4 additional recesses 7, 8 are arranged. These may be any characters, alphanumeric characters, patterns, logos or the like. Furthermore, only the metallic regions 3, 4 directly adjoin one another. There is a larger non-metallic gap 12 between the metallic areas 4 and 9. The likewise metallic area 9 can be covered with a metal which has a third intrinsic color, which differs from the intrinsic colors of the metals in the areas 3, 4.
At the in Fig. 3 illustrated security element may be, for example, a security thread 10, as in Fig. 4 shown in cross section. The security thread 10 consists of a preferably transparent carrier film 11, on which the differently colored metal layers 3, 4, 9 are arranged.

The same appearance as in Fig. 3 however, it may also have a transfer material which is used to generate security elements on security papers, documents of value or the like is used. This transfer material 13 consists of a carrier film 14, on which a plastic layer 15 is applied. In this plastic layer 15 diffraction structures 6 are introduced in the form of a relief structure. In addition, the different colored metal layers 3, 4, 9 are arranged. Finally, the transfer material 13 also has an optional adhesive layer 16, which is activated on transfer to the corresponding security paper or document of value by means of heat and pressure in the areas to be transferred to the corresponding metal layers 3, 4, 9 and the plastic layer 15 on the security paper or document of value. In a last step, the carrier film 14 is peeled off.

In the recesses 7, 8 and the gap 12, the adhesive layer 16 directly adjoins the diffraction structure 6. If the adhesive layer 16 and the plastic layer 15 have a very similar refractive index, then the diffraction structure 6 can no longer be seen in these areas.

If it requires the special application of the security element, can be dispensed with the removal of the carrier film. The carrier film can be equipped by additional measures with good adhesion properties.

Should the in Fig. 4 shown security thread also have a diffraction structure, it can be introduced into the carrier film 11 or a separate, arranged between the carrier film 11 and the metal layers 3,4 plastic layer.

In Fig. 6 is the method for producing a security element according to the invention, the metal layers in areas with recesses are provided, shown schematically. The method is explained as an example for security threads or labels, but can of course be used in security elements with other layer sequences in an analogous manner. The security elements are preferably made as a security film having multiple benefits of the security element. Starting point in the example shown here forms a self-supporting plastic film 17. This is, as in Fig. 6a ), in a first step in the areas in which the recesses are to be present later, printed with a highly pigment-containing printing ink 18, so that a large-pored imprint arises. Subsequently, the differently colored metal layers 3, 4 are applied in the desired shape over the entire printed plastic film 17. For this purpose, a vacuum vapor method is preferably used in which the individual metals 3, 4 are successively vapor-deposited on the plastic film 17 via masks. In the region of the imprint 18, no coherent metal layer forms due to the porous surface structure of the printing ink. The intermediate product provided with the metal layers 3, 4 is in Fig. 6b ).

Since no closed metal surface forms in the area of the imprint 18, the imprint 18 and the metal layer 3 or 4 present in this area can be removed almost effortlessly by washing out. Preferably water is used for washing. It may be necessary to additionally use brushes that provide complete removal of the imprint 18. The final product shows Fig. 6c ). The metal layers 3, 4 have the recesses 7,8. The security film can finally be cut into security elements of the desired shape.

The washing process has the advantage that sharp and defined edge contours are achieved, so that with the help of this method also very fine high-resolution characters or patterns can be generated in the metal layers.

The following embodiments of the FIGS. 7 to 13 are not part of the invention, but merely serve to facilitate the understanding of the invention.

Fig. 7 shows a corresponding embodiment of the in Fig. 1 In this case, the security document 1 is provided in the region of the security element 2 with a full-area metal layer 4 and a metal layer 3 provided only in certain regions, so that the metal layer 4 can be seen in the regions 7. The recesses 7 can also with the already by means of Fig. 6 described "washing process" are generated. This method is particularly useful when the different colored metal layers 3, 4 are prepared on a separate carrier and then transferred to the value document or the document substrate. Of course, any other methods for producing the recesses may also be used. Particularly noteworthy in this context is the removal method by means of a laser beam. Here, the metal layers 3, 4 are first applied over the entire surface of the document of value or a carrier. Subsequently, the metal layer 3 is acted upon in the region of the recesses 7 with a laser beam which removes the metal layer 3 in these areas without damaging the metal layer 4.

The 8 and 9 show further embodiments of the security element, which is provided with three different colored metal layers. This variant is particularly suitable for use as a security thread, but is not limited thereto.

At the in Fig. 8 shown security thread 10, the carrier film 11 is provided over the entire surface with a metal layer 9, which has a first color. In addition, the metal layers 3 and 4 are applied, whose intrinsic color differs from the metal layer 9. The metal layers 3 and 4 are provided only in regions and may have congruent recesses 19, in which the metal layer 9 is visible. In addition, the metal layer 3 can have recesses 7, in which the metal layer 4 is visible.

In Fig. 9 an embodiment is shown in which the metal layer 9 is arranged on the opposite surface of the carrier film 11. In the example shown here, the metal layer 9 has recesses 20. In the example shown here, the metal layer 9 can also consist of the same material as one of the metal layers 3, 4. If the metal layer 9 is to have a particular intrinsic color at least in regions, it can be printed with a transparent colored lacquer layer 21.

Fig. 10 shows a further embodiment of a security element in supervision. In this case, the security element has two differently colored metal layers 3, 4 and a further printed image 22, which are arranged in register with one another. The production of such a security element is preferably carried out in the washing process already described.

For this purpose, a layer structure, as in 11A is prepared, prepared on a substrate 25. In this case, in a first step, the metal layer 4 is applied over the entire surface of the carrier material 25. In a next method step, the printed image 22 is printed. Preferably overlapping and in any case passerhaltig to the print image 22, the wash ink 18 is applied. This layer structure is finally vapor-deposited over its full area with the metal layer 3 in a further vapor-deposition step. During the washing process, the washing ink 18 is removed, thereby exposing the areas of the printed image 22 and the metal layer 4 covered by this washing ink. This layer structure in cross section shows the Fig. 11b ,

In order to avoid register problems, it may also be useful to arrange the print image 22 in the edge area above the wash ink 18, as in Fig. 12a shown. During the washing process, the washing ink is dissolved and partially removed mechanically, with the overlying ink is removed with. In this way, nested surfaces of different metallic color can be produced, which can additionally be arranged passerhaltig to other color printed images. Alternatively, however, the printed image 22 may also be arranged below the wash ink.

Fig. 13 shows such a security element after the washing process in supervision. Here, three circular areas are arranged concentrically with each other. In the innermost area the printed image 22 is arranged. The printed image 22 is surrounded by a circular region of the metal layer 3, which has a first intrinsic color. This in turn is enclosed by a likewise circular area with the metal layer 4. Of the Whole area surrounding the metal layer 4 is again formed by the metal layer 3.

In the exemplary embodiments shown, the print image 22 can consist of only one color layer or even represent a complicated multicolored print image. It is also possible to use any printing inks, such as UV-curable printing inks, metallic effect inks or printing inks with luminescent or optically variable pigment additives, for this printed image.

Likewise, the outline shapes of the illustrated metal layers or printed images are not limited to the simple geometric shapes shown. Any complicated motifs are possible here. The various metal layers may also be separated by demetallized or non-metallized areas

Likewise, the embodiments shown can be combined with any other security features, such as, for example, diffraction structures or liquid-crystalline layers.

Finally, the layer sequences shown can also be transferred to any desired embodiments of the security element used. Thus, the layer sequences shown with the aid of security threads can be transferred in an analogous manner to transfer materials or label materials and vice versa.

Claims (35)

1. A security element (2) for security papers, bank notes, ID cards or the like, having at least one plastic layer (5) on which at least two metal layers (3, 4) of different color are so disposed on the same side of the plastic layer (5) that two different colors are visually recognizable, characterized in that the metal layers (3, 4) are disposed side by side, and that the metal layers (3, 4) are mutually adjacent at least in certain areas.
2. The security element (2) according to claim 1, characterized in that at least one of the metal layers (3, 4) has gaps (7, 8) in the form of alphanumeric characters, patterns, logos or the like.
3. The security element (2) according to at least one of claims 1 to 2, characterized in that a third metal layer (9) with a third color is provided that is likewise disposed on the same surface of the plastic layer (5).
4. The security element (2) according to at least one of claims 1 to 3, characterized in that the metals have different physical properties that are testable by machine.
5. The security element (2) according to at least one of claims 1 to 4, characterized in that at least one of the metal layers (3, 4, 9) is semitransparent.
6. The security element (2) according to at least one of claims 1 to 5, characterized in that the plastic layer (5) has a diffraction structure (6) in the form of a relief structure.
7. The security element (2) according to at least one of claims 1 to 6, characterized in that the plastic layer (5) is a self-supporting plastic foil (11).
8. The security element (2) according to at least one of claims 1 to 6, characterized in that the plastic layer (15) is disposed on a carrier material (14).
9. The security element (2) according to at least one of claims 1 to 6 and 8, characterized in that the security element (2) is a transfer element (13).
10. The security element (2) according to at least one of claims 1 to 7, characterized in that the security element (2) is a self-supporting label.
11. The security element (2) according to at least one of claims 1 to 10, characterized in that the security element (2) has round, oval, star-shaped, rectangular, trapezoidal or strip-shaped contours.
12. The security element (2) according to at least one of claims 1 to 8, characterized in that the security element (2) is a security thread (10).
13. A security paper for producing value documents, characterized in that it has at least one security element (2) according to at least one of claims 1 to 12.
14. The security paper according to claim 13, characterized in that the security element (2) is a security thread (10) at least partly embedded in the security paper.
15. The security paper according to claim 14, characterized in that the security paper has a through opening, the security element (2) being disposed in the area of the opening and protruding beyond it on all sides.
16. The security paper according to claim 13, characterized in that the security element (2) is a transfer element applied to the surface of the security paper.
17. The security paper according to claim 16, characterized in that the security element (2) has round, oval, star-shaped, rectangular, trapezoidal or strip-shaped contours.
18. A value document, such as a bank note, ID card or the like, characterized in that it has at least one security element (2) according to at least one of claims 1 to 12.
19. A transfer material for producing security elements (2) that has a carrier foil and at least one plastic layer (15) on which at least two metal layers (3, 4) of different color are disposed on the same surface of the plastic layer (15), characterized in that the metal layers (3, 4) are disposed side by side and are mutually adjacent at least in certain areas.
20. The transfer material according to claim 19, characterized in that the plastic layer (15) has a diffraction structure (6) in the form of a relief structure.
21. Use of a security element (2) according to at least one of claims 1 to 12 for protecting goods of any type from forgery.
22. Use of a security paper according to at least one of claims 13 to 17 for protecting goods of any type from forgery.
23. Use of a value document according to claim 18 for protecting goods of any type from forgery.
24. A method for producing a security element (2) for security papers, bank notes, ID cards or the like, having at least one plastic layer (5) on which at least two metal layers (3, 4) of different color are disposed, the metal layers (3, 4) having gaps (7, 8) in the form of alphanumeric characters, patterns, logos or the like, characterized by the following steps:

    a) providing the plastic layer (5) in the form of a self-supporting plastic foil (17) or of a carrier material (14) on which the plastic layer (5) is disposed;

    b) printing the plastic layer (5) with alphanumeric characters, patterns, logos or the like;

    c) using a printing ink with a high pigment content;

    d) drying the printing ink to form a pored, raised inking;

    e) applying the metal layers (3, 4) of different color side by side on the same side of the printed plastic layer (5), so that they are mutually adjacent at least in certain areas;

    f) removing the inking and the metal layers thereabove or penetrating the inking, by washing out with a fluid, possibly combined with mechanical action;

    g) drying and cutting the plastic foil or carrier material to size, where applicable.
25. The method according to claim 24, characterized in that the metal layers (3, 4) are applied by vapor-depositing with the aid of masks.
26. The method according to claim 24 or 25, characterized in that before step b) a metal layer (9) is applied.
27. The method according to at least one of claims 24 to 26, characterized in that the plastic foil (17) or carrier material (14) is provided in the form of an endless band and the method is performed continuously.
28. The method according to at least one of claims 24 to 27, characterized in that the printing ink is water-soluble and water is used for washing out.
29. The method according to at least one of claims 24 to 28, characterized in that the printing of the plastic layer (5) is done by gravure printing.
30. The method according to at least one of claims 24 to 29, characterized in that the plastic layer (5) is provided in step a) in the form of an endless plastic foil and cut in step g) into security threads of predetermined width.
31. The method according to at least one of claims 24 to 29, characterized in that the plastic layer (5) is disposed in step a) on a specially prepared carrier material to form a transfer material (13) that is cut in step g) into strips of predetermined width.
32. The method according to at least one of claims 24 to 31, characterized in that a diffraction structure (6) is embossed into the plastic layer (5) before step b).
33. A method for producing a security paper for producing value documents, characterized in that during the production of the security paper a security element (2) in the form of a security thread (10) is embedded, said element being produced according to at least one of claims 24 to 32.
34. A method for producing a security paper for value documents, characterized in that a security element (2) produced according to at least one of claims 24 to 32 is applied to the surface of the finished security paper.
35. The method according to claim 34, characterized in that there is formed in the security paper during papermaking an opening which is thereupon closed with the security element (2) at least on one side.

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