EP2199095B1 - Safety element for data carrier and method for producing same - Google Patents

Abstract

The method involves providing a sheet-like substrate with a recess that is formed via an opening in the substrate, where the opening is closed by a film on two sides. Additional security features are formed, and a coating is applied on the film such that a part of the coating adjoins a contour in a custom-fit manner. The contour defines a recessed region of the substrate from a region of the substrate surrounding the recess. The film is printed using a printing ink by offset printing. An independent claim is also included for a transfer element comprising a carrier layer.

Description

The invention relates to a method for producing a security element with a watermark or with a substrate having an opening, and a further security feature related thereto. The invention further relates to a data carrier and a transfer element with a security element produced according to the invention and the use of a watermark for creating a further security feature.

Data carriers, such as banknotes or other valuables, such as branded articles, are often provided with security elements that provide security functionality by allowing verification of the authenticity of the article while at the same time serving as protection against unauthorized reproduction. For such a security element may not be easily imitated for a counterfeiter, but should be inexpensive and reproducible for an authorized manufacturer and also be easily verifiable.

An example of a security element is a watermark in a paper layer of a sheet-shaped substrate, such as a banknote. Another example of a security element is an opening or window in a sheet-shaped substrate, such as a banknote.

A watermark has a foreground and a background, the watermark foreground having a changed surface height and a changed layer thickness compared to the watermark background. The surrounding paper layer of the sheet-like substrate with unaltered surface and unchanged layer thickness represents the watermark background. The watermark foreground is raised by a convex or raised against the watermark background formed a recessed, concave portion of the substrate surface. Thus, in the first case, the watermark background forms a recessed area opposite to the watermark foreground, whereas in the second case it forms a raised area. In general, a recessed area also has an increased surface roughness. Usually, the watermark foreground has raised areas or recessed areas on both sides of the substrate, respectively. However, the watermark foreground may also have a raised area on one substrate surface and a recessed area on the other substrate surface. In either case, the watermark foreground exhibits a layer thickness of the paper layer modified from the watermark background, wherein a watermark having a reduced layer thickness in the region of the watermark foreground is also referred to as a negative or light watermark (since the watermark foreground appears bright in transmitted light against the watermark background), while a watermark is also referred to as a positive or dark watermark with a layer thickness increased in the area of the watermark foreground (since the watermark foreground appears darker in the transmitted light than the watermark background). Furthermore, the watermark foreground in each case shows an altered height of the surface compared to the watermark background; so that there is a depression either in the area of the watermark foreground or in the area of the watermark background.

Similar to the case of the previously described watermark, a recessed, concave region of the substrate surface may also be present in the case of a sheet-shaped substrate having an opening which is closed on both sides by a respective film. Security paper for the production of value documents, such as banknotes, consisting of a multilayer substrate, which comprises at least one paper layer coated on both sides with a film, is known from US Pat EP 1 545 902 known.

However, the use of a watermark as a security element is problematic insofar as a high-quality printing of such a watermark is possible only with special precautions. This is partly due to the changed level of the substrate surface in the region of the watermark foreground, on the other hand also due to the increased surface roughness present in particular in the case of a depression. If such special precautions are not taken, the result is at locations where the substrate surface recedes, for example in the case of a recessed watermark in the region of the watermark foreground and in the case of a raised watermark in the region of the watermark background, a print with reduced quality, which, for example, defects in shows the applied ink layer and thus shows an ink layer with spatially varying layer thickness, which may be reduced to zero, so that entirely unprinted place arise. Such imperfections are irregularly distributed within the affected area of the watermark and generally vary between the watermarks of various paper substrates.

In the EP 1 201 821 In this connection, the production of a paper substrate with a watermark is described, which shows recesses on only one side of the paper substrate as a result of a special treatment. The paper substrate thus has a side with a smooth surface on which then a high-quality printing without the disadvantages mentioned also in the area of the watermark foreground is possible.

Since the use of a watermark or a substrate with an opening because of their intrinsic security functionality is desirable and there is also a constant need for increasing the security against counterfeiting of security elements, it is the object of the present invention, a security element with a paper substrate with a watermark Specify security element with a substrate with an opening with increased security against counterfeiting, which avoids the known from the prior art special treatment of the paper substrate. It is a further object of the present invention to provide a corresponding method for its production, a data carrier and a transfer element with such a security element, as well as a use of a watermark to increase the security against counterfeiting.

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

According to a first aspect of the invention, to create a security element, first of all a sheet-shaped substrate is provided which has a paper layer with a watermark as the first security feature. The security element further comprises a second, further security feature, which comprises a coating, which is provided on the sheet-shaped substrate in such a way that at least a part of the coating is precisely adjacent to a watermark contour delimiting a watermark foreground from a watermark background. The arranged on the sheet-shaped substrate element and the watermark are thus spatially dependent on each other.

According to a second aspect of the invention, in order to create a security element, a sheet-shaped substrate having a depression, which is formed in the substrate by an opening which is closed on both sides by a respective film, is provided. The security element further comprises a second, further security feature, which comprises a coating which is produced on the sheet-shaped substrate, in particular on a foil, such that at least a part of the coating fits precisely to a contour which forms a recessed area of the substrate from one of the recess delimiting surrounding area of the substrate adjoins.

For the purposes of the present invention, a security element comprises one or a plurality of components which, taken individually or in combination with one another, exhibit a security functionality. A single device or a combination or subcombination of devices that provide security functionality is referred to as a security feature of the security device.

Hereinafter, the parenthetical embodiments refer to the above second aspect of the invention.

In the present invention, the watermark (or opening in the substrate), taken in isolation, constitutes a security feature in the security element. The exact registration between the coating disposed on the sheet substrate and the watermark (or opening in the substrate) provides that Another security feature. This exact registration can be easily checked on the one hand. For this purpose, the element arranged on the sheet-shaped substrate is preferably visually or tactile perceptible to a viewer. Alternatively, the element can also be designed to be mechanically detectable. On the other hand, the special makes spatial reference of watermarks (or opening in the substrate) and coating in the form of an exact registration that this security feature can not be easily readjusted by a counterfeiter, however, can be created during the manufacturing process by an authorized manufacturer with little effort and easily checked by a viewer ,

In a preferred embodiment of the invention, the sheet-shaped substrate is printed with a printing ink, whereby a printing ink layer is produced on the sheet-shaped substrate. In this case, use is made of the fact that the watermark (or the opening closed on both sides with a film) comprises a recess in the substrate surface and the ink is applied to the substrate in such a way that in the recessed area of the watermark (or in the recess of the substrate, which is formed in the substrate by an opening which is closed on both sides with a respective film) no or less ink is applied than in the raised area of the watermark (or the area of the substrate surrounding the recess). If no printing ink has been applied in the recessed area, a coating results above the raised area of the watermark (or above the area of the substrate surrounding the recess), the boundary of which at least partially fits exactly to the watermark contour (or the contour which forms a recessed area the substrate is delimited by a region of the substrate surrounding the recess). If, on the other hand, a smaller quantity of printing ink was applied in the recessed area, an ink layer results visually above the recessed area of the watermark (or above the depression in the substrate, which is formed by the openings closed on both sides by a film) differs from the ink layer above the raised area by increasing the amount of ink applied a reduced layer thickness of the ink layer and thereby leads, for example, to a changed hue or to a changed translucency or to the occurrence of defects. In this case, in this case, above the raised area of the watermark (or above the area of the substrate surrounding the recess), a partial area of the ink layer is created, the boundary of which at least partially fits precisely to the watermark contour (or the contour which forms a recessed area of the substrate delimiting a region of the substrate surrounding the recess). Furthermore, above the recessed area of the watermark (or above the recess in the substrate, which is formed by the opening closed on both sides with a respective film), there is another visually distinguishable partial area of the ink layer whose boundary likewise fits exactly to the watermark contour (or the watermark) Contour which delimits a recessed area of the substrate from a region of the substrate surrounding the recess) and also lies in register with the other subarea. Thus, the transition between the two portions of the ink layer is clearly visible to an observer and shows an exact registration with the watermark contour (or the contour delimiting a recessed area of the substrate from a region of the substrate surrounding the recess). With sufficient layer thickness of the ink layer above the raised portion of the watermark (or above the area surrounding the recess of the substrate), this limit is also tactile perceptible. Therefore, the exact registration of the ink layer on the raised portion of the watermark (or on the portion of the substrate surrounding the recess) may be added to the watermark contour (or contour delimiting a recessed portion of the substrate from a portion of the substrate surrounding the recess). as well as, if appropriate, the exact registration of the at least two partial areas of the ink layer above the watermark foreground and Watermark background to each other (or the exact registration of at least two portions of the ink layer above the recessed portion of the substrate and above the recess surrounding area of the substrate to each other) are easily checked by a viewer, since even small deviations from the exact registration with the naked eye can be easily recognized.

The provision of such a coating, which differs significantly on the watermark foreground (or the recessed area of the substrate) from the watermark background (or the area of the substrate surrounding the recess), is assisted by a suitable choice of the printing method and / or printing tools , Preferably, the printing ink is applied in the offset printing or kissprinting process (in which the pressure of an applicator roll on the substrate is minimal), since in these processes the depression within the watermark (or the depression which is closed by a film sealed on both sides Opening formed in the substrate) can be easily excluded from the printing.

Preferably, a hard impression cylinder or impression roller is pressed against the sheet-shaped substrate with little mechanical pressure. The printing cylinder can not follow the depression within the watermark (or the depression, which is formed by an opening in the substrate sealed on both sides with a film), whereby the imprint on the watermark foreground (or the imprint on the recessed region of the watermark) Substrate) from the imprint on the watermark background (or the imprint on the area of the substrate surrounding the recess).

The following statements relate to preferred embodiments of the first aspect of the invention.

In the simplest case, the printing ink is printed directly on the paper layer in which the watermark is inserted. However, the sheet-shaped substrate preferably also comprises a plastic film, which is located above the paper layer. The plastic film follows the height of the surface of the paper layer and thus the depth of the watermark, which represents either the watermark foreground or the watermark background. Such films are applied, for example, to composite film banknotes. The ink may also be a paint receiving layer, which is a primer for a later applied color. Such a color or Druckarulahmeschicht is a matte, colorless, highly pigmented and porous layer, the other ink, such as a color ink, absorbs ("strikes") and thus increases the printability of such a plastic film.

In a preferred embodiment, at least two different printing inks are applied to the substrate, which form two independent color layers which, for example, lie side by side and / or in regions or completely one above the other. Preferably, the substrate is first printed with a first of the two different printing inks in such a way that above the raised area of the watermark a color layer is created as a coating, the boundaries of which are at least partially in register with the watermark contour. In contrast, above the recessed area of the watermark, a smaller amount of the first ink is applied than above the raised area of the watermark. Thus, the transition between the two subregions of the ink layer of the first ink is precisely above the

Watermark contour. Subsequently, the substrate is printed with the second printing ink, so that in the raised area of the watermark, a further color layer is created as a further precisely fitting coating of the raised area. In the recessed area of the watermark, however, no ink is applied. For this purpose, the first printing ink is applied for example with a correspondingly soft printing cylinder, while the second printing ink is applied with a contrast harder printing cylinder. Thus, the ink layer formed by the second ink has a smaller area than the ink layer formed by the first ink. In other words, there are two ink layers with different areas, wherein both the boundary of the ink layer formed by the second ink, as well as the transition between the two sections of the ink layer formed by the first ink color match exactly above the watermark contour. Thus, two precisely matched to each other ink layers are created with different sized areas. If the printing is to take place in gravure printing, the printing cylinder is advantageously always similarly hard. Here, the hardness of the impression roller can be chosen differently, and the impression pressure can be adjusted.

The different printing inks differ in their spectral, magnetic, electrical or other properties according to the desired security functionality and the desired recognizability. For example, it may be metameric colors or on the one hand to an IR-active and on the other hand to an IR-inactive ink.

Furthermore, the printing of the printing ink (s) is carried out in the simplest case only on one side of the sheet-shaped substrate. There is a depression in the area of the watermark unless special precautions have been taken however, occurring on both sides of the paper layer, the printing described above can be done on both sides of the substrate. This is particularly advantageous in the creation of a look-through register. To create a see-through register, the printing on the front and back of a substrate must be made with high register accuracy, which makes the manufacturing process consuming. Since the watermark contours are exactly superimposed on both silks of the substrate, the transitions between the print layers applied to the watermark foreground and watermark background on both sides of the substrate are precisely matched, thus providing a see-through register with contours corresponding to the watermark without the usual high demands on the manufacturing process on the front and back of the substrate is possible.

In a particularly preferred embodiment, the first and the second ink are applied over the recessed and raised areas of the watermark as described above, but on the two opposite sides of the sheet substrate, so that on the one side only a printing ink layer of the first ink and on the other, opposite side of the substrate exclusively an ink layer of the second ink is created. As a result, surfaces of different sizes, matched to one another, are formed on the front and rear side of the substrate.

In a further advantageous embodiment of the invention, the watermark is used as an exposure mask for, for example, electromagnetic radiation. In other words, the fact is exploited that the watermark foreground filters due to the changed layer thickness there incident radiation more or less than the surrounding Watermark background. Accordingly, a radiation-sensitive layer is applied to the substrate in a region above the watermark so that the radiation-sensitive layer covers the watermark contour and thus forms a coherent region of the radiation-sensitive layer, which is arranged partially on the watermark foreground and partly on the watermark background. Subsequently, this radiation-sensitive layer is irradiated through the substrate, that is to say from the side opposite the radiation-sensitive layer. Because of the filter effect of the substrate in the area of the watermark foreground, which is increased or decreased depending on the layer thickness, radiation having an intensity which differs from the intensity in the radiation-sensitive layer above the area of the watermark background enters the radiation-sensitive layer above the area of the watermark foreground. The interaction of the radiation-sensitive layer with the incident radiation is greater above the area of the substrate with the smaller layer thickness than above the area of the substrate with the increased layer thickness. Simplified, these two different areas of the radiation-sensitive layer are referred to as exposed and unexposed area. Thus, an interaction region of radiation-sensitive layer and radiation is created, which is precisely matched to the watermark contour. The irradiated layer above the watermark foreground thus forms at least part of a precisely fitting coating of the watermark.

The radiation-sensitive layer is an activatable layer which exhibits, for example, a color change, a color change and / or a crosslinking and thus a polymerization of the radiation-sensitive layer, as is the case, for example, with a photoresist layer. Will then the non-activated radiation-sensitive layer, for example Non-polymerized layer removed, preferably tactile perceivable structures can be created, which are the exact fit to the watermark within the substrate. Subsequently, all remaining reactive substances can be crosslinked in a second exposure.

In a preferred embodiment, a further layer is applied to the radiation-sensitive layer. This can be applied before or after the irradiation. The further layer is, for example, a metal layer and the radiation-sensitive layer preferably forms information recognizable to a viewer, for example in the form of a motif. After precisely irradiating the radiation-sensitive layer, depending on whether it is a positive or negative-working radiation-sensitive layer, the exposed, more irradiated area or the unexposed, less strongly irradiated area of the radiation-sensitive layer is removed together with the further, further layer , This can be done by a lift-off or an etching process. This results in the desired areas an exact registration of the other layer to the watermark contour. The further layer can also be a plurality of layers, for example a metallization and a suitable protective layer. As a result, the underlying metallization, for example, be protected from environmental influences.

The following statements relate to preferred embodiments of the second aspect of the invention.

The sheet-shaped substrate for creating a sheet-shaped substrate having a depression which is formed in the substrate by an opening which is closed on both sides by a respective film can be formed in one or more layers be made of paper and / or a plastic film. As paper any kind of paper comes into consideration, in particular paper made of cotton. Of course, it is also possible to use paper which contains a proportion of polymeric material in the range of 0 <x <100. As a plastic film such as a polyester film into consideration. The film may also be monoaxially or biaxially stretched. The stretching of the film, inter alia, leads to it receiving polarizing properties that can be used as another security feature. It may also be expedient if the substrate material is a multilayer composite which has at least one layer of paper or a paper-like material. Such a composite is characterized by an extremely high stability, which is for the durability of the paper of great advantage. It is also conceivable to use a multilayer, paper-free composite material as the substrate material. This composite material can be used to advantage in certain climatic regions of the earth. All materials used as substrate material can have additives which serve as an authenticity feature. It is primarily to be thought of luminescent, which are preferably transparent in the visible wavelength range and in the non-visible wavelength range by a suitable tool, such as a UV or IR radiation emitting radiation source can be excited to a visible or at least detectable with tools To produce luminescence.

By the term "opening" is meant a through hole, i. an opening which pierces the substrate in a straight line.

The through opening in the substrate can be produced by punching or cutting, in particular by laser cutting.

The continuous opening may have any outline contours and, for example, be round, oval, rectangular, trapezoidal, star-shaped or even strip-shaped. The through-opening may be composed of a plurality of continuous partial openings, which are separated by webs from the substrate. The continuous partial openings can have any outline contours and are preferably used as an additional design element. For the production of the respective partial openings, all the above-mentioned methods for producing the opening can be used analogously.

The film with which the opening in the substrate is closed on both sides, in order to form a depression in the substrate in this way, is preferably an at least partially translucent or transparent film. More preferably, the film is made transparent. Under transparent here is to be understood a light transmittance of at least 90% of the incident light, translucent under a light transmittance of less than 90%, preferably between 80% and 20%. Preferably, the film for closing the opening in the region of the opening has at least one translucent area. In particular, it is preferred that the film for closing the opening in the region of the opening has at least one transparent region. As a foil, e.g. Polyolefin films (e.g., PE (polyethylene), PP (polypropylene) or cycloolefinic copolymers), films of polyolefin derivatives or polycarbonate, PMMA, especially PET (polyethylene terephthalate), PBT (polybutylene terephthalate), PP, PA (polyamide). The film may also be monoaxially or biaxially stretched.

The film for closing the opening may be full-surface, such as in the case of a film composite banknote. Foil composite banknotes are from the EP 1545 902 known. The production of a film composite banknote can For example, by the film is cold-laminated to the paper layer. In this case, an adhesive is applied to the film, dried and optionally activated by temperatures of preferably not more than 80 to 90 ° C. In particular, the film is not melted or excessively stressed by heat. This has the advantage that any existing stretching of the films are not destroyed, but are still present after laminating. Preferably, the adhesive is a water or UV crosslinking adhesive. Particular preference is given to using a wet adhesive, in particular a polyurethane adhesive. However, the production of a film composite banknote can also be effected by extruding the film onto the paper layer. In the present invention, the film for closing the opening but also as a strip, patch, label or stamping foil element can be applied to the substrate, in particular laminated. Preferably, the application takes place here by means of an adhesive or lacquer layer. For example, hot-melt adhesives or reaction lacquers can be used as the adhesive. Suitable adhesives include polyvinyl acetates, polyvinyl chloride derivatives, acrylates, polyurethanes, polyesters, copolymers of these groups and UV adhesives. A patch is a label-shaped single element. A strip has a width substantially less than its length, the strip preferably extending from one edge of the substrate to an opposite edge.

The opening in the substrate can be closed on both sides, each with a full-surface film. Alternatively, the opening in the substrate can be closed on both sides with in each case one part-area foil (for example a strip, patch, label or embossing foil element). Likewise, the opening in the substrate on one side with a full-surface film, and be closed on the opposite side of the full-surface film with a partial film.

The printing ink is printed directly on the film with which the opening in the substrate is sealed. The film follows the raised area above the unchanged substrate surface to a recessed area formed by the opening within the substrate. The ink may also be a paint receiving layer, which is a primer for a later applied color. Such a color or print receiving layer is a matte, colorless, highly pigmented and porous layer which absorbs ("strikes off") another ink, such as a colored ink, thereby increasing the printability of such film.

In a preferred embodiment, at least two different printing inks are applied to the film with which the opening in the substrate is closed, which form two mutually independent color layers which, for example, lie side by side and / or in regions or completely one above the other. Preferably, the film with which the opening is closed in the substrate, first printed with a first of the two different printing inks such that above the raised portion of the unchanged substrate surface, a color layer is provided as a coating whose boundaries at least partially fit exactly to the contour, the delimiting a recessed area of the substrate from a region of the substrate surrounding the recess. In contrast, above the recessed area formed by the opening within the substrate, a smaller amount of the first ink is applied than above the raised area of the unaltered substrate surface. Thus, the transition between the two subregions of the printing ink layer of the first printing ink lies precisely over the contour, which delimits a recessed region of the substrate from a region of the substrate surrounding the depression. Subsequently, the substrate with the printed second ink, so that in the raised region of the substrate surface is unchanged, a further color layer is created as a more accurate coating of the raised area. On the other hand, in the recessed area formed by the opening within the substrate, no ink is applied. For this purpose, the first printing ink is applied for example with a correspondingly soft printing cylinder, while the second printing ink is applied with a contrast harder printing cylinder. Thus, the ink layer formed by the second ink has a smaller area than the ink layer formed by the first ink. In other words, there are two ink layers with different areas, wherein both the boundary of the ink layer formed by the second ink, as well as the transition between the two portions of the ink layer formed by the first ink accurately above the contour, the recessed portion of the substrate of delimiting a region of the substrate surrounding the depression. Thus, two precisely matched to each other ink layers are created with different sized areas.

The different printing inks differ in their spectral, magnetic, electrical or other properties according to the desired security functionality and the desired recognizability. For example, it may be metameric colors or on the one hand to an IR-active and on the other hand to an IR-inactive ink.

Furthermore, the printing of the printing ink (s) is carried out in the simplest case only on one side of the sheet-shaped substrate. Since the depression, which is formed in the substrate by the opening closed in each case on one side with a film, unless special precautions are taken, but occurs on both sides of the substrate, the above-described Printing can be done on both sides of the substrate. This is particularly advantageous in the creation of a look-through register. To create a see-through register, the printing on the front and back of a substrate must be made with high register accuracy, which makes the manufacturing process consuming. Thus, because the contours delimiting a recessed area of the substrate from a region of the substrate surrounding the recess are exactly superimposed on both the substrates, the transitions between the printed layers deposited on the recessed area and the raised area are on either side of the substrate exactly to each other, whereby the creation of a see-through register with contours corresponding to the recess in the substrate, which is formed by the closed on both sides with a respective film opening, without the usual high demands on the manufacturing process on the front and back of the substrate is possible.

In a particularly preferred embodiment, the first and the second ink are applied over the recessed and raised areas as described above, but on the two opposite sides of the sheet substrate, so that on the one side only a printing ink layer of the first ink and on the On the other, opposite side of the substrate exclusively an ink layer of the second ink is created. As a result, surfaces of different sizes, matched to one another, are formed on the front and rear side of the substrate.

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

Fig.1

eine Banknote mit einem Sicherheitselement;

Fig. 2a - 2c

eine Schnittansicht des in Fig.1 gezeigten Sicherheitselementes und zwei Varianten davon;

Fig. 3a, 3b

Schnittansichten eines zweiten Ausführungsbeispiels und ein zugehöriges Herstellungsverfahren; und

Fig. 4a - 4c

Schnittansichten eines dritten Ausführungsbeispiels und ein zugehöriges Herstellungsverfahren;

Fig. 5

eine Schnittansicht einer Folienverbundbanknote mit einer Öff- nung; und

Fig. 6a - 6c

Schnittansichten eines Ausführungsbeispiels zum zweiten As- pekt der Erfindung und zwei Varianten davon.

In detail, the figures show:

Fig.1

a banknote with a security element;

Fig. 2a - 2c

a sectional view of the in Fig.1 shown security element and two variants thereof;

Fig. 3a, 3b

Sectional views of a second embodiment and an associated manufacturing method; and

Fig. 4a - 4c

Sectional views of a third embodiment and an associated manufacturing method;

Fig. 5

a sectional view of a film composite banknote with an opening; and

Fig. 6a - 6c

Sectional views of an embodiment of the second aspect of the invention and two variants thereof.

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

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

Security elements with their security features allow verification of a data medium or other value document for authenticity. For this purpose, such a security element may not be easily adjusted by a counterfeiter. This can be done, for example, by the use of generally inaccessible materials or manufacturing processes which, for example, allow for a verifiable but unadjustable combination of elements into a feature which can then serve as a safety feature. On the other hand, such a security element with the security features for the authorized Manufacturers reproducible to be produced in order to ensure the proof of its authenticity ensuring properties in a large number of, for example, individualized data carriers.

For this purpose, the use of watermarks in sheet-shaped substrates, such as banknotes, is known. The watermark is generally in a paper substrate, which paper preferably comprises cotton, but may also be composed of cellulose and other fibers. A paper substrate is made by scooping from a pulp, for example, with a long or round screen, and the watermarks are created on the scoop during scooping, for example by means of elevations or embossings. Since in general neither the starting materials, such as cotton fibers, nor the produced watermark paper are freely accessible, nor the manufacturing process can be easily readjusted, has created a watermark in the paper already on its own security functionality and thus as a security feature in one serve as a higher-level security element or as an independent security element.

Hereinafter, with regard to the first aspect of the invention, as security elements security elements are shown whose watermarks have bilateral depressions of the substrate and thus a reduced layer thickness of the paper substrate in the region of the watermark foreground. However, the exemplary embodiments shown can also be transferred directly to security elements whose watermarks have elevations of the substrate and / or an increased layer thickness in the region of the watermark foreground.

Fig.1 shows an embodiment with a banknote 1 as a disk with a watermark and a security element in plan view. Fig. 2a shows a section through the in Fig.1 illustrated banknote and the security element along the line A-A '. The banknote 1 in this case also forms the data carrier to be secured and also the sheet-shaped substrate of the security element with a paper layer 3 with watermark incorporated therein. The watermark foreground 2 of the watermark is square in plan view, showing a reduced layer thickness of the paper layer 3 and depressions on both surface sides of the paper layer 3. On the front side of the paper layer 3 is an ink layer 4, which on the watermark foreground 2 in the area 4b defects and a lower Has layer thickness than in the area 4a on the watermark background. Overall, less ink is applied to the watermark foreground 2 in region 4b than on the watermark background in region 4a. Likewise, on the reverse side of the paper layer 3, a different printing ink layer 5 is applied, which also shows defects within the watermark foreground 2 of the watermark in the region 5b and a smaller layer thickness than in the region 5a outside the watermark foreground 2. Areas 4b and 5b each form homogeneous layers with uniformly distributed imperfections whose respective contours are visually easily recognizable vis-à-vis areas 4a and 5a for a viewer. At the same time, the contours between the areas 4a and 4b border precisely on the watermark contour 2a on the front side. In a central region of the watermark, neither on the front nor on the backside is a printed layer applied, so that a recess 6 results in plan view.

The color layers 4 and 5 on the front and back of the banknote 1 have different shades and form a see-through register. Because of the Reduced layer thickness of the ink layers 4 and 5 on the watermark foreground 2 generate the areas 4b and 5b in the viewer a different color than the respective lying on the watermark background areas 4a and 5a, although on the front and back of the banknote 1 each of the identical ink in each of the same manufacturing step has been applied. In this way, when the banknote 1 is viewed from above, the transition between the respective areas 4a and 4b as well as 5a and 5b can be easily recognized visually. Since this transition is determined by the watermark contour 2a, these transitions, for example, in in Fig. 1 indicated area 7, on the front and back of the banknote 1 a high registration accuracy, without that this makes special demands on the printing process with respect to the achievable registration accuracy of the imprint of the print layers 4 and 5 on the front and back of the bill. Thus, the contour 2a of the watermark is advantageously used for the creation of a high registration pass-through register.

In principle, all types of watermarks are suitable as watermarks. However, watermarks having a particularly small layer thickness, a particularly pronounced indentation and / or particularly steep flank angles on the contour 2 a are particularly preferred, as is the case, for example, with type E watermarks. These have a reduced layer thickness in the region of the watermark foreground, are therefore also referred to as highlights and are preferably formed by pieces of wire which are welded onto a round screen, which is used during the scooping of the pulp.

In Fig. 2b is a variant of in Fig. 2a shown embodiment shown. In this case, covers the ink layer 4 on the front of the paper layer 3 the entire watermark with the watermark foreground 2 completely. For this purpose, the printing ink was applied with a suitably soft printing cylinder, so that ink is also applied inside the recess of the watermark foreground 2. Thus, both subregions 4a and 4b fit exactly to each other as well as to the watermark contour 2a. On the other hand, the printing ink layer 5 different therefrom on the back side of the paper layer 3 merely covers the watermark background of the watermark and completely encloses the watermark foreground 2. For this purpose, the printing ink was applied with a suitably hard printing cylinder, so that the printing ink is applied only outside the recess of the watermark foreground 2. Thus, the partial area 5a lies exactly to the watermark contour 2a as well as to the transition between the areas 4a and 4b on the front side of the paper layer 3.

In the in Fig. 2c In the variant shown, the ink layer 5 is not applied on the back side of the paper layer 3, but on the front side of the paper layer 3 above the ink layer 4. Again, the ink layer 5 merely covers the watermark background, increasing the overall layer thickness of the applied ink layers 4 and 5 on the front side of the paper layer 3, which enhances the tactile perceptibility of the watermark background. In addition, there are further degrees of freedom for the design of the printed watermark.

In the FIGS. 3a and 3b shows a second embodiment of a security element and the associated manufacturing method, in which the substrate next to a paper layer 3, a plastic film 8 has. The plastic film follows in the area of the watermark foreground 2 of the watermark whose recess.

Furthermore, in the FIGS. 3a and 3b a printing cylinder 9 is shown, which indicates the printing process schematically. In this case, the printing cylinder itself is hard and rigid and is performed with only a small contact pressure on the consisting of plastic film 8 and paper layer 3 substrate. Because of the large layer thickness of the paper layer 3 in the region of the watermark background, the printing cylinder 9 does not follow the depression of the watermark foreground 2 of the watermark during the printing operation over the substrate during the printing process. Accordingly, no ink is applied to the watermark foreground 2. Thus, only outside the watermark, a printing ink layer is produced, which then fits precisely to the contours 2a of the watermark.

Thus, the watermark is highlighted by a recess in the ink layer 4. The exact registration of the recess or the various areas of the ink layer is due to the depression in the substrate surface in the area of the watermark foreground 2 automatically, without further precautions are necessary when printing the ink.

The security element shown in the embodiment has a printed plastic film 8 and is therefore generally exposed to splitting attacks. Such a splitting attack could be used to transfer the removed plastic film to a counterfeit substrate 3, thus creating a counterfeit with at least one true carrier film 8 with true ink layer 4. In this case, however, even if the counterfeit substrate 3 has a corresponding watermark 2, when assembling counterfeit substrate 3 and previously removed by splitting attack plastic film 8 could be the security feature of the exact registration between printing ink layer 4 and watermark contour 2a can not be restored. However, since this security feature is easily verifiable, the embodiment has increased counterfeit protection.

In the Figures 4a, 4b and 4c a third embodiment of a security element and the associated manufacturing method is shown.

First, as in Fig. 4a shown, a radiation-sensitive layer 10 applied to the watermark, so that both Wasserzeichenvördergrund 2 and watermark background are at least partially covered by a continuous layer 10. The layer 10 shows a sufficient layer thickness, so that even in the region of the watermark foreground a continuous layer without defects occurs. Directly on the radiation-sensitive layer 10 is a metallization 11 as another layer.

In a second step, the radiation-sensitive layer 10 from the opposite side (in Fig. 4b from below) through the substrate, as indicated by the arrows. The radiation used can be, for example, UV radiation, IR radiation and / or laser radiation, depending on the type of radiation sensitivity of the layer 10 used. The radiation is attenuated more strongly when passing through the substrate 3 in the region of the watermark background because of the increased layer thickness of the substrate 3 there than in the region of the watermark foreground 2, so that in the region of the watermark front 2 an interaction of the radiation-sensitive layer 10 takes place with radiation of higher intensity.

In the exemplary embodiment, the radiation-sensitive layer 10 comprises uncrosslinked constituents which crosslink on irradiation, as in the case of an irradiation Polymerization happens. Thus, the radiation creates an interaction region which adjoins the watermark foreground 2 precisely. Accordingly, a matching region 10b is created within the layer 10, which differs due to the irradiation of the above the watermark background lying, surrounding layer 10 in the area 10a.

Subsequently, the non-crosslinked or incompletely crosslinked surrounding area 10a is removed, which due to the stronger crosslinking in the area 10b and the associated different chemical properties compared to the layer 10 in the area 10a can be done by washing or by a dissolving process. Together with the layer 10 in the region 10a, the overlying metallization 11 is also removed, as a result of which on the substrate 3 in the region of the watermark foreground 2 a metallization 11 remains, which lies precisely in line with the watermark contour 2a.

In a variant of the third exemplary embodiment, the layer thickness of the watermark foreground 2, the material of the paper substrate 3, the type and intensity of the radiation, as well as the material of the radiation-sensitive layer 10 are selected such that radiation-sensitive layer 10 lies behind the watermark background in the direction of irradiation no interaction with the radiation-sensitive layer takes place, for example, in that the radiation is attenuated by the paper substrate 3 in the region of the watermark background below an activation threshold value of the radiation-sensitive layer 10.

In a further variant of the third embodiment, a radiation-sensitive layer 10 is used whose crosslinking is prevented by the irradiation (for example, a negative-working photoresist layer). As a result, the not or only incompletely crosslinked layer 10 can be selectively removed in the region 10b above the watermark foreground 2 after the irradiation, whereby a crosslinked layer 10 in the region 10a above the watermark background, optionally with additionally applied metallization 11 remains, which fits the watermark contour 2a lies.

Embodiments according to the second aspect of the invention are shown below, in which a sheet-shaped substrate has a depression which is formed in the substrate by an opening which is closed on both sides by a respective film. The leaf-shaped substrate has recesses on both sides in the region of the opening.

Fig. 5 shows a section through a composite film banknote. The sheet-shaped substrate has a paper layer 12 in which a through opening 13 has been produced by punching or (laser) cutting. The opening 13 is closed on both sides with a respective film 14. In this way, depressions are formed on both surface sides of the substrate.

Fig. 6a shows an embodiment with a composite film banknote having an opening. On the front side of the paper layer 12 is a film 14 and above a printing ink layer 15, which has defects within the opening 13 in the region 15b and a smaller layer thickness than in the region 15a surrounding the recess. Overall, less ink is applied within the opening 13 in the area 15b than on the raised area 15a of the unchanged substrate surface. Likewise, on the rear side of the paper layer 12 there is applied a printing ink layer 16 different therefrom, which likewise has defects within the opening 13 in the region 16b and a smaller layer thickness than in the region 16a outside the opening 13 shows. Areas 15b and 16b each form homogeneous layers with uniformly distributed imperfections whose respective contours are visually easily recognizable vis-à-vis each of the areas 15a and 16a for a viewer. In the process, the contours between the regions 15a and 15b on the front side adjoin the contour in a precisely fitting manner, which delimits a recessed region of the substrate from a region of the substrate surrounding the depression. In a central region of the opening, a pressure layer is applied neither on the front nor on the back, so that a recess 17 results in plan view.

The color layers 15 and 16 on the front and back of the film composite bank note have different shades and form a see-through register. Because of the reduced layer thickness of the ink layers 15 and 16 in the region of the opening 13, the areas 15b and 16b produce a different color impression in the viewer than the respectively lying outside the opening areas 15a and 16a, although on the front and back of the film composite banknote respectively the identical ink in each has been applied to the same manufacturing step. As a result, the transition between in each case the areas 15a and 15b as well as 16a and 16b can be visually recognized well when the film composite banknote is viewed from above. Since this transition is determined by the contour which delimits a recessed area of the substrate from a region of the substrate surrounding the recess, these transitions on the front and rear side of the composite film banknote show a high register accuracy, without any special demands on the printing method with respect to the printing process to be achieved registration accuracy of the imprint of the print layers 15 and 16 on the front and back of the composite film banknote notes. Thus, the contour becomes a recessed area of the substrate from a region of the substrate surrounding the recess delimits, advantageously used for the creation of a transparency register with high registration accuracy.

In Fig. 6b is a variant of in Fig. 6a shown embodiment shown. In this case, the ink layer 15 on the front side of the paper layer 12 completely covers the entire opening 13. For this purpose, the printing ink was applied with a suitably soft printing cylinder, so that ink is also applied within the recess of the substrate. Thus, both partial regions 15a and 15b fit precisely both to one another and to the contour which delimits a recessed region of the substrate from a region of the substrate surrounding the depression. On the other hand, the printing ink layer 16 different therefrom on the rear side of the paper layer 12 only covers the raised area of the substrate surface surrounding the opening and completely encloses the area of the opening 13. For this purpose, the printing ink was applied with a suitably hard printing cylinder, so that the printing ink is applied only outside the recess of the substrate. Thus, the partial region 16a fits precisely both to the contour which delimits a recessed region of the substrate from a region of the substrate surrounding the depression, and to the transition between the regions 15a and 15b on the front side of the paper layer 12.

In the in Fig. 6c In the variant shown, the ink layer 16 is not applied on the back of the paper layer 12, but on the front side of the paper layer 12 above the ink layer 15. The ink layer 16 in turn covers only the raised area of the substrate surface surrounding the opening, whereby the total layer thickness of the applied ink layers 15 and 16 on the front side of the paper layer 12 increases, which the tactile perceptibility of raised portion of the substrate surface surrounding the opening reinforced.

In the Figures 5 . 6a, 6b and 6c The exemplary embodiments shown relate to a film composite bank note in which an opening formed in the substrate is closed on both sides over its full area, each with a film. Instead of a full-surface film but also a partial film can be used for double-sided closing of the opening, which is applied as a strip, patch, label or stamping foil element on the substrate. Alternatively, the opening on one side may be closed with a full-area film, and on the opposite side of the full-surface film with a partial film.

Claims (22)

1. A method for producing a security element for a data carrier (1), comprising the step of:

   - making available a sheet-shaped substrate (3) having a recess (2) which is formed by an opening in the substrate (3) that is closed on both sides with one foil in each case, characterized by the further step of

   - creating a further security feature (4a, 4b) by producing a coating (4) on at least one foil such that at least a portion of the coating borders in accurately fitting fashion on a contour which delimits a recessed region (2) of the substrate from a region of the substrate surrounding the recess.
2. The method according to claim 1, characterized in that the creating of the further security feature (4a, 4b) comprises the step of:

   - printing the foil with a printing ink (4a, 4b) such that an ink layer (4) is created as a coating in a region of the substrate (3) surrounding the recess in an accurate fit with the contour which delimits a recessed region (2a) of the substrate from a region of the substrate surrounding the recess, and either no printing ink or less printing ink than in the region of the substrate surrounding the recess is applied in a recessed region (2a) of the substrate.
3. The method according to claim 2, characterized in that the foil is printed by the offset printing or kiss-printing method.
4. The method according to claim 2 or 3, characterized in that the printing ink is applied with a hard printing cylinder and/or at low contact pressure.
5. A method for producing a security element for a data carrier (1), comprising the step of:

   - making available a sheet-shaped substrate (3) which has a paper layer with a watermark (2),

   characterized by the further step of:

   - creating a further security feature by producing a coating (4) on the sheet-shaped substrate such that at least a portion of the coating borders in accurately fitting fashion on a watermark contour delimiting a watermark foreground (2) from a watermark background.
6. The method according to claim 5, characterized in that the creating of the further security feature comprises the step of:

   - printing the sheet-shaped substrate (3) with a printing ink (4) such that an ink layer is created as a coating in a raised region of the watermark (2) in an accurate fit with the watermark contour (2a), and either no printing ink or less printing ink than in the raised region of the watermark is applied in a recessed region of the watermark.
7. The method according to claim 6, characterized in that the sheet-shaped substrate (3) is printed by the offset printing or kiss-printing method.
8. The method according to claim 6 or 7, characterized in that the printing ink (4) is applied with a hard printing cylinder and/or with low contact pressure.
9. The method according to any of claims 6 to 8, characterized in that the printing ink (4) is printed on the paper layer of the sheet-shaped substrate (3).
10. The method according to any of claims 6 to 9, characterized in that the substrate (3) has a plastic foil at least above the region of the watermark contour (2a), and the printing ink (4) is applied to the plastic foil.
11. The method according to any of claims 6 to 10, characterized in that a first (4) and a second printing ink (5) different therefrom is applied to the substrate (3), in particular in such a way that the creating of the further security feature comprises the steps of:

    - printing the substrate with the first printing ink (4) such that an ink layer is created as a coating in the raised region of the watermark (2) in an accurate fit with the watermark contour (2a), and less printing ink than in the raised region of the watermark is applied in the recessed region of the watermark, and

    - printing the substrate (3) with the second printing ink (5) such that a further ink layer (5b) is created as a further coating in the raised region of the watermark in an accurate fit with the watermark contour (2a), and no printing ink is applied in the recessed region of the watermark.
12. The method according to any of claims 6 to 11, characterized in that the printing ink (4, 5) is applied to front side and back side of the substrate (3), in particular such that a see-through register is produced.
13. The method according to claims 11 and 12, characterized in that the first printing ink (4) is applied to the front side of the substrate and the second printing ink (5) to the back side of the substrate (3).
14. The method according to claim 5, characterized in that the creating of the further security feature comprises the steps of:

    - making available a radiation-sensitive layer on the sheet-shaped substrate at least above the watermark contour, and

    - irradiating the radiation-sensitive layer at least in the region of the watermark contour through the substrate for creating a layer irradiated in accurately fitting fashion.
15. The method according to claim 14, characterized in that

    - the radiation-sensitive layer is sensitive to UV radiation, IR radiation and/or laser radiation, and/or

    - the radiation-sensitive layer shows a color change and/or cross-linking upon irradiation.
16. The method according to claim 14 or 15, characterized in that the creating of the further security feature comprises the further steps of:

    - applying a further layer to the radiation-sensitive layer at least above the watermark contour, and

    - removing the further layer in accurately fitting fashion with respect to the watermark contour by removing the radiation-sensitive layer irradiated in accurately fitting fashion.
17. A security element for a data carrier (1), comprising a sheet-shaped substrate (3) having a recess (2) which is formed by an opening in the substrate that is closed on both sides with one foil in each case, and a further security feature (4a, 4b) which has a coating (4) which is arranged on at least one foil such that at least a portion of the coating borders in accurately fitting fashion on a contour which delimits a recessed region of the substrate from a region of the substrate surrounding the recess.
18. A security element for a data carrier (1), comprising a sheet-shaped substrate (3) which has a paper layer with a watermark, and a further security feature which has a coating which is arranged on the sheet-shaped substrate (3) such that at least a portion of the coating borders in accurately fitting fashion on a watermark contour (2a) delimiting a watermark foreground from a watermark background.
19. A data carrier (1), in particular value document, branded article and the like, comprising a security element according to claim 17 or 18 or a security element which is produced according to any of claims 1 to 16.
20. A transfer element comprising a security element according to claim 17 or 18 or a security element which is produced according to any of claims 1 to 16, and which is preferably applied in strippable fashion to a carrier layer.
21. Use of a watermark in a paper layer (3) of a sheet-shaped substrate for creating a further security feature by producing a coating on the sheet-shaped substrate such that at least a portion of the coating borders in accurately fitting fashion on a watermark contour (2a) delimiting a watermark foreground from a watermark background.
22. Use of a security element according to claim 17 or 18, of a transfer element according to claim 20 or of a security element which is produced according to any of claims 1 to 16, for authenticating data carriers and goods, in particular branded articles.

Images