EP2138318B1 - Safety element with ducts and method for producing same - Google Patents

Abstract

The method comprises applying a printing dye on a side of translucent substrate, where the corresponding printing layer (2) comprises a recess and applying a wash color within the first recess so that the corresponding wash color layer overlay a partial area (4) of the first recess, where the application of the printing dye and the wash color takes place in a printing process, applying a cover layer (5) on the applied side of the substrate, where the cover layer interferes a color impression different from the printing dye and washing the wash color. The method comprises applying a printing dye on a side of translucent substrate, where the corresponding printing layer (2) comprises a recess and applying a wash color within the first recess so that the corresponding wash color layer overlay a partial area (4) of the first recess, where the application of the printing dye and the wash color takes place in a printing process, applying a cover layer (5) on the applied side of the substrate, where the cover layer interferes a color impression different from the printing dye, washing the wash color including the cover layer, where a second recess lying within the first recess is created in the cover layer, applying an opaque white layer and/or a metallic layer (8) on the printed side of the substrate, which is visible through the second recess and is translucent, and applying an effective layer on the side of the substrate opposite to the printed side. The cover layer for the second recess forms a contour with uniform width and has a metallic layer, which is opaque. The printing dye is translucent. The effective layer produces an optically variable effect. An independent claim is included for a security element for valuable object.

Description

The invention relates to a security element for valuables having a substrate, on the surface of which a printing ink having at least one recess is applied, a security paper, a valuable article and a method for producing such a security element.

Valuables for the purposes of the present invention include in particular value documents such as banknotes, stocks, bonds, certificates, vouchers, checks, lottery tickets, high-quality tickets, passports, ID cards, credit cards, as well as other valuables. Such valuables are secured by introducing or applying security elements against counterfeiting. In the following, the invention is explained using the example of value documents produced from security paper. However, the invention can also be applied to valuables made of other materials.

The security element is usually a security thread which is completely or even partially embedded in the paper of the value document, around a foil strip applied to the value document via an opening or a window in the paper, or a transfer element, such as a so-called patch, which is applied in the form of a label on the document of value or optionally via an opening therein.

Security elements of this type typically include a translucent, ie transparent or semi-transparent plastic film as a substrate, which is metallically coated, printed, dyed or provided with pigment-containing substances. Is such a security element partially or arranged inside a value document, the areas in which the security element is located show a different appearance in supervision than in transparency. For example, a security thread in supervision rather inconspicuous, in contrast, appears as a conspicuous, for example, predominantly darker stripes. Such an effect can not be imitated by a print on the paper and therefore contributes particularly to the security against counterfeiting.

Security elements are also known which contain diffraction patterns, such as holograms, kinegrams or pixelgrams, whereby the protection against forgery of such elements is based on the variable color impression that they impart to the observer depending on the viewing direction.

To increase the security against counterfeiting such security elements are often provided with recesses, for example coating-free areas, in the form of patterns, graphic symbols or codes.

For the production of metal-free areas is in the document WO 99/13157 a so-called washing process is described in which a substrate, for example a translucent carrier film, is printed using a high-pigment ink with a desired pattern. This ink is referred to as a wash color and forms after drying due to the high pigment content a porous, raised paint on the substrate. A thin covering layer, for example a metallic layer, which only partially covers the paint application of the washing ink because of its large surface area and its porous structure, is then applied to the substrate thus printed. The paint application of the wash paint and the overlying cover layer can then be removed by washing with a suitable solvent, so that in the cover layer on the previously printed with the wash ink areas of the substrate recesses are generated in the cover layer. By the achievable sharp contours, a legible lettering can be introduced into the security element. Such lettering, in particular as a so-called negative writing, is then particularly clearly visible in review.

An advancement of this washing procedure is in the WO 03/091042 A2 described. It describes a security element with two metal layers into which recesses are introduced by means of the washing process. In this case, for example, first the areas are printed on a substrate with wash ink, in which recesses in both metal layers are to be formed and then applied the first metal layer. Subsequently, the regions are printed on the first metal layer with wash ink, in which recesses are to be formed only in the second metal layer, and then the second metal layer is applied. Finally, the wash is washed out and thus created the desired recesses. If appropriate, a further washing step between the application of the two metal layers may also be present. Through the use of different materials and different layer thicknesses for the two metal layers, different color and brightness impressions can be generated in viewing and review.

In the publication EP 1 609 619 A2 For example, further security elements with recesses are described which appear metallic when viewed from one side and have a color shift effect when viewed from the other side, which is produced by an effect layer based on liquid crystals.

A disadvantage of the known security elements or their production method is that multicolored security elements, that is to say security elements which impart different color impressions to the viewer, can only be obtained by complex production methods. So must in the production of a multicolor security element in the aforementioned WO 03/091042 A2 metallized twice and also printed twice a wash. The two-time metallization is complex and expensive.

The object of the present invention is to provide a cost-effective production method with a small number of production steps, which creates a multi-colored security element with high security against counterfeiting. It is a further object of the invention to provide a security paper and a valuable item with high security against counterfeiting and to specify a suitable use of such a security element.

This object is achieved by a manufacturing method, a security element, a security paper, a valuable article and a use having the features of the independent claims. The dependent claims and the following description relate to preferred embodiments and further developments.

The present invention is based on the recognition that a register-accurate introduction of range boundaries, such as recesses in security elements, can serve as an authenticity feature. The security against counterfeiting can be increased by the lowest possible pass-tolerance.

Accordingly, to produce the security element, a printing ink is printed on one side of a translucent substrate. The resulting print layer has a first recess, preferably in the form of alphanumeric or other graphic characters. In the same printing process, a washing ink is also printed in such a way in the recess that the resulting washing layer covers a portion of the first recess. The wash color is thereby positioned with the highest possible register accuracy relative to the contours of the recess. Subsequently, a cover layer is applied to the printed side of the substrate, which imparts a color impression different from the printing ink. Thereafter, the washing is washed out. The wash ink contains, as described above, a high pigment content and forms after printing a pearly raised paint with a porous structure. The layer thickness of the applied covering layer is chosen to be sufficiently thin so that it only partially covers the porous structure of the washing ink. Therefore, by washing out of the wash ink and the applied on the print job of the wash coat by removing the washing ink is removed and there is a recess in the cover, said second recess is spatially within the first recess in the print layer of the ink. The second recess is formed in the subregion in which the washing ink was previously applied, and forms a coating region which is free of coating after washing on the substrate, in which neither the covering layer nor the printing ink is applied. Because of the register-accurate positioning relative to the contours of the first recess, obtained in this way a corresponding register accurate positioning of the second recess within the first recess. The translucency of the second recess corresponds to this immediately after washing out, so apart from possible further coatings of the security element, the translucency of the substrate.

With the manufacturing method, a security element is created, which comprises a translucent substrate with a printed side, on which a printing layer of a printing ink is applied with a first recess. A part of the first recess is covered by the cover layer, which imparts a different color impression from the printing ink. The part not covered by the covering layer forms a further, second recess, which thus lies within the first recess. The second recess is due to the manufacturing process passerhaltig arranged to the first recess, d. H. Both recesses have because of the application of the printing and washing ink in the same printing on a low pass tolerance.

The ink preferably covers a majority of the surface of the substrate and is then perceived by the viewer of the security element as the background of the security element.

In the security element, materials are used as the cover layer and as the printing ink which, after application to the substrate, produce different color impressions in the viewer. As a result, a viewer, at least in supervision, can clearly distinguish the areas of the printing ink, that is to say the background of the security element, from the two recesses and thus clearly recognize the visual information provided by the two recesses. Thus, the invention provides a security element with at least three passerhaltig to each other arranged areas, which each produce different color impressions in the viewer and thus are easily recognizable.

The invention uses in the production of the security element on the one hand, the advantages offered by the printing of various soluble colors. To wash out the wash ink, a solvent is used in which the wash color is soluble and the ink is insoluble, allowing for selective removal of the wash color from the substrate. In the simplest case, the solvent is water and the wash is water-soluble, while the ink is waterproof, that is insoluble in water.

On the other hand, the invention makes use of the possibility of applying the printing ink and the washing ink to the substrate in a single, common printing operation. The printing and washing ink is preferably printed simultaneously or at least immediately after one another in the same printing operation, so that there is no further process step between the printing of the printing ink and the printing of the washing ink. As a result, the printing ink and the washing color can be precisely registered, i. H. be printed with a minimum pass tolerance on the substrate.

In the above mentioned WO 03/091042 A2 described methods, the various recesses are produced by printing the wash color, wherein the printing is done in part before the application of the first metal layer and partly thereafter. In other words, the printing of the wash ink is interrupted by a metallization and optionally by further steps, for example etching steps. As a result, the corresponding recesses have a large pass tolerance of at most 0.3 mm to each other. By printing printing ink and wash ink in one printing operation, such an insetter pressure can be avoided.

In contrast, in the case of the printing ink and wash ink printing according to the invention in one printing operation, the registration tolerance of the two printing layers is less than 0.1 mm, preferably less than 0.05 mm, 0.02 mm or even less than 0.01 mm.

The printing of the printing and washing ink according to the invention in one printing operation can be carried out simultaneously or successively, i. occur sequentially in preferably immediately consecutive partial printing operations. In this case, the individual partial printing processes must be carried out with a high register accuracy relative to each other, so that the different print layers of printing and washing paint are not laterally shifted in the plane of the translucent substrate against each other.

For this purpose, in a printing press usually the substrate to be printed is passed between two parallel, rotatably mounted cylinders. On the one cylinder, the impression cylinder, a colored printing plate is arranged on the surface. The other cylinder serves as a counter-cylinder to transfer under pressure a motif to be printed from the printing plate to the substrate.

For sequential printing of multiple colors, for example, a multi-cylinder printing machine is known. In this, the substrate successively passes through several printing units, each of which has a pair of cylinders and means for applying the ink to the respective printing cylinder. Each printer prints a different color, such as ink and wash. In between, the substrate runs more or less freely.

As another printing machine, the single-cylinder or central cylinder printing machine is known. In such a central cylinder printing machine, the substrate runs tightly stretched around a single central cylinder, on the circumference of several printing units, each with a printing cylinder are arranged. On each of the printing cylinder, a printing plate for a different color is arranged. The circulating around the central cylinder substrate so happens in the circumferential direction of the central cylinder successively the pressure cylinder for the different colors, such as printing and washing paint. The advantage of such a central cylinder printing machine is that the substrate to be printed always rests on the central cylinder and thus runs between the printing units no free web length of the substrate, whereby an optimal substrate guidance of the substrate to be printed is ensured between the individual printing units. Therefore, the central cylinder printing machine allows printing of multiple colors in one printing operation, which ensures a particularly high registration accuracy.

By choosing the geometric shape of both the first and the second recess on the substrate, visual information can be given to the viewer, for example in the form of alphanumeric or other graphic characters, or in the form of artistic motifs. The information of the first recess may differ from the information of the second recess.

Both recesses, however, can convey identical information to the viewer. Advantageously, the covering layer completely surrounds the second recess and forms a contour with a uniform, constant width within the first recess for the second recess. The geometric shape of the first and second recess then differ only by a magnification factor. Such a contour increases the readability of the visual information on the one hand, because both the shape of the second recess, as well as the shape of the first recess in the background of the security element give the same information to the viewer. On the other hand, deviations from such a constant width of the contour can be easily perceived by a viewer, which is why the constant contour width is available as a further authenticity feature. Because of the high register accuracy of the printing and washing ink applied in a printing operation, such a contour of constant width can be easily produced. Poor registration tolerances are easily recognizable, especially with contours of small width.

As covering layer, a further printing ink or even a metallic layer can be used. In the latter case, it is possible by means of the invention to introduce second recesses in a metallic layer, which have a high register accuracy to first recesses in the printing layer of the printing ink. As a result, around each of the second recesses of the security element around a metallic contour can be produced with a very high uniformity of the width.

The metallic coating is preferably applied over the entire surface during production and thus also covers the printing ink. When using a translucent or semi-transparent printing ink, a metallic impression can thus be optically produced not only in a partial region of the second recess, that is to say, for example, in the region of the contour, but also in the region of the printing ink. In other words, a metallic visual impression can thus also be generated in the entire background area of the security element. When using a light metal, such as aluminum, it can in combination with a yellow-colored printing ink in this area a golden metallic impression can be generated while using a red-translucent ink a copper-colored metallic impression can be generated. It can thus be produced several different metallic color impressions, while only a single metallic layer is applied.

Preferably, in a subsequent production step, a further layer is applied to the printed side of the security element. This further layer is then visible through the second recesses of the security element, that is, through the subregions in which the wash ink has previously been printed, and determines the color impression of the second recesses. This creates a further degree of freedom for achieving the desired color impressions of the security element to be produced.

In an advantageous embodiment, this further layer consists of a metal layer which produces a color impression which is different from the color impression of the printing ink and the color impression of the covering layer. If a metal layer is used as the cover layer, a different metal is used for the further layer. With a suitable choice of the color impression (hue, color value, etc.) of the printing ink and the cover layer, a high contrast and thus a good recognizability of the areas created by the first and second recess can be achieved.

In an alternative advantageous embodiment, the further layer comprises opaque white. In view of the security element, the second recess is thus visually perceivable as a bright, white surface. If, furthermore, a light-colored metal, such as, for example, aluminum, is used as the covering layer, and a translucent and thus darkening printing ink is used as the printing ink, it appears the viewer sees the entire area of the first recess bright, while the background of the security element appears dark.

If the further layer continues to be formed as a translucent layer and the cover layer as an opaque layer, if the cover layer also covers the printing ink or the printing ink itself is already opaque, only the area of the second recess appears transparent while the other areas of the security element are transparent that is, the part of the first recess covered by the covering layer and the area of the printing ink appear dark.

If the covering layer produces a contour around the second recess, that is to say if the first and the second recess form the same graphic characters that differ only by a magnification factor, then the observer will see the same sign in plan view as larger than in phantom, which is another easy one to be tested authenticity feature of the security element forms.

In a further step of the production process, an effect layer is preferably applied, which produces an optically variable effect. The effect layer is preferably applied to the opposite side of the printed side of the substrate. The effect layer may include, for example, a thermochromic layer, a diffraction-generating layer such as a relief-structure layer or a color-shift-effect layer such as an interference layer, a liquid crystal layer or a layer of interference layer pigments or liquid crystal pigments. The background color of the security element, that is to say the hue in the area of the applied printing ink, is preferably chosen so that the visibility of the optically variable Effects is supported. For example, when using an effect layer with a color shift effect, a dark, preferably black, printing ink is used for the background, which may then be non-translucent.

Fig. 1

eine Banknote;

Fig. 2a - 2c

ein erstes Ausführungsbeispiel des erfindungsgemäßen Her- stellungsverfahrens;

Fig. 3

einen Schichtaufbau eines ersten Ausführungsbeispiels des erfindungsgemäßen Sicherheitselementes;

Fig. 4

eine Draufsicht auf ein zweites Ausführungsbeispiel des Si- cherheitselementes;

Fig. 5

einen Schichtaufbau des zweiten Ausführungsbeispiels des Sicherheitselementes;

Fig. 6

einen Schichtaufbau eines dritten Ausführungsbeispiels des Sicherheitselementes;

Fig. 7a - 7c

Herstellungsschritte eines vierten Ausführungsbeispiels des Sicherheitselementes;

Fig. 8a, 8b

Herstellungsschritte eines fünften Ausführungsbeispiels des Sicherheitselementes;

Fig. 9a, 9b

einen weiteren Herstellungsschritt und Schichtaufbau eines sechsten Ausführungsbeispiels des Sicherheitselementes; und

Fig. 10a - 10e

Herstellungsschritte und Schichtaufbau eines siebenten Aus- führungsbeispiels des Sicherheitselementes.

Further embodiments and advantages of the invention are explained below by way of example with reference to the figures. Show it:

Fig. 1

a banknote;

Fig. 2a - 2c

a first embodiment of the manufacturing process according to the invention;

Fig. 3

a layer structure of a first embodiment of the security element according to the invention;

Fig. 4

a plan view of a second embodiment of the safety element;

Fig. 5

a layer structure of the second embodiment of the security element;

Fig. 6

a layer structure of a third embodiment of the security element;

Fig. 7a - 7c

Manufacturing steps of a fourth embodiment of the security element;

Fig. 8a, 8b

Manufacturing steps of a fifth embodiment of the security element;

Fig. 9a, 9b

a further manufacturing step and layer structure of a sixth embodiment of the security element; and

Fig. 10a - 10e

Manufacturing steps and layer structure of a seventh exemplary embodiment of the security element.

In Fig. 1 For example, a banknote with a security element in the form of a security thread 11 is shown schematically. The invention explained by way of example below can be implemented, for example, in such a security thread, which can be present as a window thread or as a completely embedded security thread or optionally also as a patch applied to the surface. Other shapes and locations, in particular via openings in the banknote, are possible.

In the Fig. 2a to 2c the steps of a first embodiment for producing such a security element are outlined. In Fig. 3 the layer structure of the resulting security element is shown in cross section.

On a transparent plastic film, such as a PET film 1, as a substrate, first, a printing layer 2 of a waterproof printing ink with recesses 3 is applied ( Fig. 2a ). The recesses 3 may take the form of alphanumeric or other graphic characters or other motifs. In the subregions 4 of the recesses 3, a water-soluble washing ink is printed. In the exemplary embodiment shown, the geometric shape of the partial regions 4 corresponds to a magnification factor of those of the recesses 3, and it remains in the recesses 3 each have a peripheral region 5 of constant width, which is printed with neither the waterproof ink, nor with the water-soluble wash ink. This non-printed edge area separates the printed areas with the wash ink 4 of the waterproof ink spatially on the substrate 1. Subsequently, a metallic layer 5 'of aluminum is applied over the entire surface and then removed the wash along with the metal layer applied above, whereby further, second recesses arise in the metal layer at the points of the portion 4 ( Fig. 2c ). The resulting security element thus receives a silvery, metallic contour in the edge regions 5 of the recesses 3, which is clearly different for a viewer in supervision of the waterproof ink, which is itself, for example, yellow glaze. The metallic layer 5 ', which is also applied above the printing layer 2 of the water-resistant printing ink, is not removed by the washing step, for which reason the applied metal layer 5' forms a defined background for the yellow-translucent, ie semitransparent printing ink. On the security element then a further transparent plastic film 6 and / or a laminating adhesive and a cover white layer 7 is applied ( Fig. 3 ).

The thus created security element shows the viewer three areas with different color impressions. The in the Fig. 2a to 2c shown in plan view (top view) corresponds to the consideration of in Fig. 3 shown in cross-section security element from below. The subregion 4 forming the second recesses, in which the water-soluble washing ink was temporarily applied during the production process, appears white in plan view because of the underlying opaque white layer 7, while the contour formed by the edge region 5 is due to the applied coating Aluminum layer 5 'appears silvery, shiny metallic. In the area of the water-resistant printing ink, a metallic color impression also results due to the printed metal layer 5 '. Because of the translucent property of the printing ink used for the printing layer 2, however, the silvery-shiny color impression of the underlying aluminum layer 5 'is colored. This results in the use of a yellow-colored printing ink for the printing layer 2 in conjunction with the underlying aluminum layer 5 'a gold-colored color impression, while using, for example, a red-colored printing ink in conjunction with the underlying aluminum layer 5' results in a copper-colored color impression.

The security element according to the in the Fig. 2a to 2c and 3 shown first embodiment, the viewer therefore produces two different metallic color impressions, while only one metal layer 5 ', so only a single metallic substance, is present.

When viewed from above, the aluminum layer 5 'in the contour formed by the edge region 5 as well as the opaque white layer 7 produce an overall bright color impression in the observer, so that the entire recess 3 appears bright, whereas the background of the security element, ie the area of the printed layer 2, becomes darker displayed. The viewer thus perceives as information especially the entire area of the recess 3 true. On the other hand, because of the applied aluminum layer 5 ', both the background of the security element, ie the area of the print layer 2, and the edge region 5 forming the contour within the recess 3 are opaque and appear transparent in the background, whereas the subregion 4 forming the second recess is dark because of the Translucent opaque white layer 7 in the viewer generated in the look a bright color impression. Thus appears the observer, the graphic characters formed by the recess in supervision greater than in review.

In the 4 and 5 is a second embodiment of a security element in plan view and shown in cross section. The structure and production correspond in many parts in the Fig. 2a to 2c and 3 shown first embodiment. In addition, in this case below the opaque white layer 7, a further metallic layer 8 of gold is applied. As a result, the partial regions 4 of the recesses 3, unlike in the first exemplary embodiment, no longer appear white in the top view, but are golden. In particular, when using a red-translucent, water-resistant printing ink for the printing layer 2 can thus be produced in supervision by imprinting two metallic layers 5 ', 8 three metallic color impressions, namely coppery background, ie in the field of waterproof printing layer 2, silver in the areas The layer thickness of the applied gold layer 8 is chosen to be sufficiently low, so that the central portion 4 of the recesses 3 is still translucent and thus appears transparent in review.

In Fig. 6 a third embodiment of a security element is shown in cross section. Therein, on the side of the substrate 1 opposite the printing layer 2 of the water-resistant printing ink, first a laminating varnish 9 and then an effect layer 10 are applied, which is protected by a further transparent plastic film 6. The effect layer generates a color shift effect (color shift effect) and comprises a directionally reflecting layer that generates different color impressions when the viewing angle changes in reflection. such Optically variable properties can be produced, for example, with interference layer pigments and / or liquid crystal pigments, which are admixed to a transparent binder or a transparent plastic film.

Im in Fig. 6 3, the effect layer 10 comprises cholesteric liquid crystals which, depending on the viewing angle, exhibit a color change between magenta and green. This color change is particularly well visible against a dark background, which is why a water-resistant ink 2 here a black ink instead of the yellow or red translucent ink is selected. Despite the color-shift effect, the effect layer 10 is highly transparent, as a result of which both the silver-shining aluminum contour-forming edge region 5 and the central white region 7, which is white because of the opaque white layer 7, are visually readily recognizable within the recess 3.

In a variant of the third exemplary embodiment which is not shown, an additional gold layer 8, as shown in the second exemplary embodiment, can also be added here. Then, even when using the effect layer of the central portion 4 of the recesses 3 in supervision golden-colored.

Instead of the color shift effect generating effect layer 10, a different type of effect layer may be provided, such as a thermochromic layer below a certain Umschlagtemperatur, for example, 30 ° C, opaque and above the Umschlagtemperatur is colorless or translucent, so that only then the underlying information recognizable becomes. Alternatively, the desired optically variable effect of the effect layer 10 can also be produced by a relief structure, which in a transparent lacquer or plastic layer is embossed in the form of diffraction structures.

In the Fig. 7a to 7c the manufacturing steps of a security element according to a fourth embodiment are shown. Again, a wash color in recesses 3 a print layer of a water-resistant ink in a common printing process is printed in register with each other ( Fig. 7a . 7b ). In this case, however, the geometric shape of the portion 4, in which the washing ink is printed, differs from the shape of the recess 3. After the metallization and washing out, one obtains again a security element, which conveys at least three different color impressions ( Fig. 7c ). In this case, however, the geometric shape of the recesses 3 conveys to the viewer a different information than the shape of the second recesses 3. Also in this exemplary embodiment, the translucent subregion 4 lies in a metallic edge region 5, which is formed by an aluminum layer 5. However, this edge region 5, in contrast to the embodiments previously shown, does not form a contour of constant width. Nevertheless, at least mechanically, the Passerhaltigkeit the areas 3 and 4 can be checked as an authenticity feature.

In the Fig. 8a and 8b the manufacturing method of a fifth embodiment is outlined. Therein, the imprinted waterproof ink shows two different types of recesses 3, on the one hand alphanumeric characters in the form of negative writing and on the other hand continuously free areas in the form of diagonal stripes. In these diagonal stripes, the water-soluble washing ink is printed in partial regions 4 ( Fig. 8a ). After the metallization with, for example, aluminum 5 'and the subsequent washing out of the washing paint, two types of diagonal stripes, which are composed of a total of three different color impressions, result alternately: In a first bias strip the printing layer 2 of the yellow-transparent, waterproof ink is underlaid by the aluminum layer 5 ', and the printed information shows the viewer in the form of silver motifs "100" in a gold-colored background. In the adjacent bias strip, the viewer sees the information in the form of translucent motifs "PL", formed by the subarea 4, in a silver-colored background.

In Fig. 9a a manufacturing step is shown, which corresponds to the in the Fig. 2a to 2c followed manufacturing steps of the first embodiment followed and creates a sixth embodiment of the security element. Fig. 9b shows a sectional view of the layer structure of the resulting sixth embodiment. In the first embodiment, the waterproof ink 2 is arranged on the side of the substrate 1, which forms the back of the security element, that is behind the substrate 1 in the direction of a view. On the opposite side of the substrate 1, which forms the front of the security element, in order to create the seventh embodiment, first a water-soluble washing ink is again printed in the area 11. Subsequently, an effect layer 10 is applied over this entire surface of the substrate, which produces a color shift effect (color shift effect). In Fig. 9b the effect layer is shown in a single layer and contains, for example, interference layer pigments and / or liquid crystal pigments. However, the effect layer 10 can also be formed as a continuous interference layer and to have a multilayer structure with a reflector layer, a dielectric layer and a partial reflector layer, which are formed for example of Al, SiO ₂ and Cr. Subsequently, the water-soluble wash ink is removed from the front of the security element together with the effect layer 10 arranged thereon, whereby a recess 11 in the effect layer 10 is created. Are the recesses 4 on the back of the security element in the viewing direction completely within the recesses 11 on the front of the security element, as shown in the Fig. 9a and 9b is shown, the effect layer 10 is located on the front of the security element completely within areas in which on the back of the security element, the metallic layer 5 'is applied. This metallic layer 5 ', because of its opacity, provides a sufficiently dark background against which the color shift effect of the effect layer 10 can be well observed. The color shift effect, for example, creates a color change between magenta and green. This color shift effect is evident in the areas outside the recess 11. Within the recess 11, the viewer sees the print layer 2 of the waterproof ink. If the printing ink is yellowish-translucent and the metallic layer 5 'lying behind it in the direction of observation is an aluminum layer, the result is a gold-colored color impression for a viewer. If the printing ink is red, the result is a coppery color impression. In the region of the recess 4, the security element is transparent both on the front side and on the rear side and thus allows the view of an optionally further underlying layer, for example an opaque white layer 7 or a further metal layer, as known from the second exemplary embodiment. The recess 4 further has the contour 5 already described in the first embodiment, which when created by an aluminum layer 5 ', creates a silver-colored color impression.

In the Fig. 10a to 10d the manufacturing steps of a seventh embodiment of the security element are shown and in Fig. 10e a sectional view of the layer structure of the resulting seventh security element. On a transparent substrate 1 is first, as in Fig. 10a represented, applied in the area 4, a water-soluble wash. Subsequently, a metallic layer 5 ', for example made of aluminum, copper or gold, is applied over it, whereby a silver-colored, a copper-colored or a gold-colored color impression is created. Subsequently, the washing ink is removed, wherein in the metallic layer 5 'recesses 4 are created, as in Fig. 10b is shown. The metallized side of the substrate 1 forms the back of the security element. On the opposite side of the substrate 1, ie on the front side of the security element to be created, a water-soluble washing ink is again applied in region 11. Subsequently, the effect layer 10 is applied to the front side, wherein the effect layer 10 in turn comprises interference layer pigments or liquid crystal pigments or has a multilayer, continuous interference layer structure or a continuous liquid crystal layer. Subsequently, the washing ink is also washed on the front of the security element, whereby recesses 11 are created in the effect layer 10. The color shift effect of the effect layer 10 can be well perceived in those areas in which there is no recess 4 in the metallic layer 5 'on the back of the security element. On the other hand, in the area of recess 4 in the metallic layer 5 'on the rear side of the security element, the color shift effect of the effect layer can essentially not be perceived. In other words, a color shift effect can be perceived in areas where there are neither recesses 4 on the back nor recesses 11 on the front of the security element. The arrangement of the recesses 4 and 11 on the back and front of the security element to each other can be designed in various ways. On the one hand, the recess 4 in plan view of the security element completely lie within a recess 11, such as on the right and left side in Fig. 10d shown becomes. On the other hand, the recesses 4 can also lie outside of recesses 11, as in the central region of the Fig. 10d is shown. Furthermore, the recesses 4 on the back of the security element can form information for the viewer, for example in the form of a so-called clear text.

Thus, on the one hand, this information can be arranged directly within the area that shows the color-shift effect, in that the recess is present only on the rear side, but not on the front side of the security element, as in the central region of the security element Fig. 10d is shown. On the other hand, this information can be arranged within a metal-colored area, as on the right and the left side in FIG Fig. 10d is shown. In the latter case, the metal-colored area is limited by the recess 11 in the effect layer 10 on the front side of the security element. The metal-colored area then shows the color of the metal used for the metallic layer 5 '.

Thus, a sequence of information (recesses) may be created on a security thread, such information being alternately surrounded by a metal-colored area, for example, or located directly within a region exhibiting a color-shift effect, as shown in FIG Fig. 10d is indicated.

If the effect layer 10 is in the form of a multilayer interference layer, it is sufficient, in order to suppress its color shift effect, to provide a recess 11 in one of these multiple layers. In the manufacture of the security element according to the seventh embodiment, the water-soluble wash paint applied in each case on the back and front side can also be removed in a common washout step.

Claims (17)

1. A method for producing a security element for objects of value comprising the steps of:

   - printing a printing ink on one side of a translucent substrate (1), wherein the thereby arising printed layer (2) has at least a first gap (3), and printing a washing ink within the first gap (3), so that the thereby arising washing ink layer covers a partial area (4) of the first gap (3), wherein the printing of the printing ink and the printing of the washing ink are effected in one printing operation;

   - applying a cover layer (5') to the printed side of the substrate, wherein the cover layer (5') conveys a color impression different from the printing ink; and

   - washing out the washing ink including the cover layer (5') applied thereto, thereby creating in the cover layer (5') a second gap (4) lying within the first gap (3) of the printed layer (2).
2. The method according to claim 1, characterized in that the cover layer (5') forms for the second gap (4) a contour with uniform width.
3. The method according to claim 1 or 2, characterized in that the cover layer (5') is a metallic layer which is preferably opaque.
4. The method according to any of claims 1 to 3, characterized in that the printing ink is transparent.
5. The method according to any of claims 1 to 4, characterized by the step, following the washing out, of:

   - applying a further layer (7, 8), preferably an opaque white layer (7) and/or a metallic layer (8), to the printed side of the substrate (1), which is visible through the second gap (4) and is preferably translucent.
6. The method according to any of claims 1 to 5, characterized by the step, following the washing out, of:

   - applying an effect layer (10) to the side of the substrate (1) opposing the printed side, wherein the effect layer (10) produces an optically variable effect.
7. A security element for objects of value, comprising a translucent substrate (1) with a printed side to which there is applied a printed layer (2) of a printing ink with a first gap (3), characterized in that within the first gap (3) there is applied a cover layer (5') which conveys a color impression different from the printing ink, wherein a second gap (4) lying within the first gap (3) is located in exact register to the first gap (3) in the cover layer (5').
8. The security element according to claim 7, characterized in that the register tolerance of the second gap (4) relative to the first gap (3) amounts to less than 0.1 mm.
9. The security element according to claim 7 or 8, characterized in that the cover layer (5') forms for the second gap (4) a contour with uniform width.
10. The security element according to any of claims 7 to 9, characterized in that the cover layer (5') is a metallic layer which is preferably opaque.
11. The security element according to any of claims 7 to 10, characterized in that the printing ink is transparent.
12. The security element according to claim 10 and 11, characterized in that the metallic layer (5')is applied to the printed side of the substrate (1) additionally over the printing ink.
13. The security element according to any of claims 7 to 12, characterized by a further layer (7, 8) arranged on the printed side of the substrate (1), preferably an opaque white layer (7) or a metallic layer (8), which determines the color impression of the second gap (4) and is preferably translucent.
14. The security element according to any of claims 7 to 13, characterized by an effect layer (10) arranged on the side opposing the printed side and producing an optically variable effect.
15. A security paper, comprising a security element according to any of claims 7 to 14, wherein the security element preferably covers a window area or a hole in the security paper.
16. An object of value, comprising a security element according to any of claims 7 to 14, wherein the security element preferably covers a window area or a hole in the object of value.
17. Use of a security element according to any of claims 7 to 14, of a security paper according to claim 15, or of an object of value according to claim 16, for safeguarding

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