DE102004031043A1 - Security element with introduced motives - Google Patents

Abstract

The The invention relates to a security element for security papers, value documents and the like, with motifs incorporated in the security element in the form of patterns, signs or codes. According to the invention Subjects looking at the security element from opposite Seen side with different optical appearance, where the motifs, viewed from a first side, as recesses are recognizable in an opaque cover layer, and by the second, opposite Seen side by, by a substantially transparent or translucent optically variable effect layer with an optically variable effect appear.

Description

The The invention relates to a security element for security papers, value documents and the like, in the motifs in the form of patterns, characters or Codings are introduced. The invention also relates to a security paper, a value document and a method for producing such Security element.

value documents are often equipped with security elements for protection, the a review of Allow the authenticity of the value document and at the same time as protection to prevent unauthorized reproduction. Value documents within the meaning of the present In particular, banknotes, stocks, bonds, certificates, Vouchers, checks, high-quality tickets, but also others forgery-prone papers, like passes and other identification documents as well as product security elements, such as Labels, seals, packaging and the like. The term "value document" concludes below all such documents and product securing means. Under "security paper", however, the not yet ready precursor understood to the value document.

to increase security and as counterfeit protection The security elements are often with a so-called negative writing Mistake. This negative writing is due to metal-free areas in an otherwise continuous metallic coating of the carrier material of the security element.

to Preparation of such metal-free areas is in the document WO 99/13157 describes a washing process in which a translucent support film using a high pigment ink with one desired Pattern is printed. Due to the high proportion of pigment part forms the Printing ink after drying a porous, sublime application of paint. On the printed carrier foil then becomes a thin one Cover layer formed in the area of the paint application because of the color body his big one surface and the porous structure only partially covered. The paint application and the overlying Cover layer can then removed by washing with a suitable solvent, so that in the cover layer in the originally printed areas the carrier film Recesses are generated. Due to the achievable sharp contours For example, by printing a lettering a good readable negative writing are introduced into the cover layer.

outgoing It is the object of the invention to provide a security element to propose the type mentioned, which is a high security against counterfeiting and at the same time easy to manufacture.

These Task is characterized by the security element with the characteristics of Main claim solved. A method for its production, a security paper and a Value document with such a security element are in the sibling claims specified. Further developments of the invention are the subject of the dependent claims.

To The invention, the introduced motifs in consideration of Security elements from opposite Recognizable sides with different optical appearance. The motives are viewed from a first page as Recesses in an opaque top layer recognizable, and kick off the second, opposite Seen side by a substantially transparent or translucent optically variable effect layer with an optically variable Effect in appearance.

One Such security element can, for example, as a window security thread be introduced into the paper of a banknote. The optically variable Effect of the security thread then appears in sections the surface of the paper while the opaque, especially metallic cover layer the visibility of the thread on the back of the paper reduced.

The introduced motifs, such as a lettering or a number sequence, appear congruent on both sides of the banknote, However, with different optical impression, so the effect though easy to recognize and check though hard to imitate.

To An advantageous development of the invention comprises the opaque Cover layer two on top of each other arranged color layers, of which a first color layer in one liquid soluble is, and the second color layer is insoluble in the liquid. In particular, the first color layer may be water-soluble and the second color layer be waterproof. It can However, other liquids are used in the invention. It is only important that the two printing inks on each other are turned off that the liquid for the first color layer a solvent However, the second ink layer in the liquid is insoluble.

Preferably, the first color layer has a high pigment content, so that it forms a porous structure with a high surface area after drying. The pigment content is suitably between 10% and 80%, preferably about 60%, in each case based on the dry weight of the paint. As Pig For example, natural raw materials such as chalk, bentonite, aerosil or titanium dioxide can be used.

The first color layer is typically a uniform ink educated. However, it can also be provided that the first color layer Partial areas with different color impression has to different colors Create areas on the security element.

The second color layer is preferably on nitrocellulose, polyamide or PVC base made or based on a UV-curable Paint.

Furthermore the second color layer can also be machine-readable feature substances, in particular luminescent, magnetic and / or electrically conductive feature substances included, so in addition an invisible, only machine-detectable coding in the security element can be incorporated. The second color layer can be uniform be, or partial areas with different color impression and / or Subareas with different machine-readable feature substances exhibit.

In In some embodiments, it is expedient if the first and / or second color layer have a dark hue, such as black. However, there are other shades the two color layers within the scope of the invention. For example is usually not a high order quantity for the first color coat required, so that this entire surface even in a lighter, not opaque hue can be applied.

To According to the invention, the first and second color layers are advantageous congruent recesses, at least part of the in form the security element introduced motives. Another Part of the motifs may be due to additional print layers or optical effect layers are formed, wherein the two motif parts independent from each other can be, but also work together and, for example, to a total motive complete can.

In an advantageous embodiment of the security element according to the invention For example, the opaque cover layer comprises a metal layer. The metal layer can be made of aluminum, but also of other metal, such as copper, gold, iron, chromium, nickel, silver, platinum, palladium, titanium, another non-ferrous metal, or an alloy of these metals. The metal layer is preferably applied by the vacuum vapor deposition method.

In a preferred variant of the invention, the metal layer over the arranged two color layers and has with these congruent Cutouts on, at least part of the security element make up motives. The security element then points to the side of the cover layer looks like a shiny metallic appearance, of which the introduced motifs in particular in transmitted light distinctly contrasting.

In an alternative, likewise advantageous variant is the metal layer arranged between the two color layers and has with them congruent recesses, at least part of the in form the security element introduced motives. With special Advantage may be the second, about the metal layer arranged color layer while a yellow, reddish brown or brown hue, so when looking at the side of the top layer ago a gold-colored or copper-colored Color impression arises.

In In all embodiments, the effect layer expediently optically variable pigments, preferably liquid crystal pigments or interference layer pigments, on. The effect layer can also be thermochromic Have properties, so at a certain envelope temperature a reversible color change demonstrate. The turnover temperature is preferably above the ambient temperature, in particular above 25 ° C. For example the effect layer can be opaque under normal conditions and at warming become colorless or translucent, and so on Make information recognizable. In a further advantageous Embodiment, the effect layer has a diffraction structure, especially in the form of an embossed Relief structure. In all variants, the effect layer over the entire surface or only in certain areas in the form of patterns, symbols or codes be upset.

The Opaque cover layer and the optically variable effect layer are preferably on a support, in particular a transparent or translucent carrier, in front, wherein the cover layer and the effect layer preferably on opposite sides of the transparent or translucent carrier arranged are. In some embodiments the carrier only needed for production and can be removed after the completion of the security element become.

To the Protection against mechanical or chemical influences is the opaque cover layer preferably with a transparent or translucent protective layer Mistake. The protective layer can at the same time a carrier for the cover layer and form the effect layer.

In this context, the carrier can or the protective layer may advantageously be provided with further layers, in particular with opaque, lasing or luminescent color layers or with feature layers which comprise machine-readable feature substances.

To an advantageous embodiment of the invention, the security element in addition to the effect layer on a thermochromic layer on the below their envelope temperature the introduced motifs when viewed from one of the opposite Pages partially or completely hidden. In a variant this is thermochromic layer on the first side of the security element arranged above the opaque cover layer. Alternatively, the thermochromic layer on the second side of the security element arranged between the opaque cover layer and the effect layer be.

In both cases the thermochromic layer is preferably a thermochromic liquid crystal layer formed, preferably with a Umschlagtemperatur in the range of 25 ° C to 60 ° C, especially preferably in the range of 30 ° C up to 60 ° C.

The described security elements can, for example, in the form a security strip, a security thread, a security tape, a label-shaped Single element (patch) or a transfer element for application to a security paper, value document or the like is formed be.

The Invention also encompasses a security paper for the production of security documents, such as banknotes, ID cards or the like, with an above equipped security element is equipped. The security paper in particular, at least one continuous window area or contain a hole covered with the security element, so the two different optical appearances in the window area or hole are recognizable. The security element can, for example in the form of a window security thread, too so embedded in the security paper that the optically variable Effect only in the sub-areas where the security element to the surface of the paper occurs, recognizable, while the recesses in the Opaque cover layer when viewing the security paper in transmitted light emerge.

The Invention contains Furthermore, equipped with a security element described above Value document, for example a banknote. The value document can also a window area covered with the security element or a hole covered with it.

The described security element, security paper or document of value can also be used to secure goods of any kind.

to Production of a security element with incorporated motifs in the form of patterns, signs or encodings is a security element with one on top of another arranged opaque cover layer and a substantially transparent or produced translucent optically variable effect layer, wherein the Motifs are introduced as recesses in the opaque cover layer, so they look at the security element from opposite Recognizable sides with different optical appearance are. In this case, the opaque cover layer is preferably applied to a transparent cover or translucent carrier or applied to the optically variable effect layer.

In A first preferred variant of the method is applied during application the opaque cover layer a first, soluble in a liquid, preferably water-soluble ink layer imprinted, and on this first color layer in areas one second, in the liquid insoluble, preferably waterproof color layer printed. The first color layer can be full surface or even already printed in the form of a motif. The areas of the first color layer not protected by the second color layer are subsequently through a washing step with the liquid removed, so that corresponding recesses arise in the opaque cover layer. The two color layers are preferred before the washing step still applied a metal layer, in particular vapor-deposited.

at an alternative, also advantageous variant is when applying the opaque cover layer a first, soluble in a liquid, preferably water-soluble ink layer imprinted, a metal layer applied to the first color layer, in particular vapor-deposited, and then in areas on the metal layer a second, in the liquid insoluble, preferably waterproof color layer printed. The first color layer and the metal layer can entire area or in the form of motifs. Again, the unprotected areas the first color layer and the metal layer by the following Wash step away so that corresponding recesses in the opaque top layer arise.

In A preferred embodiment of the method is the first color layer from a water-soluble Printing ink and the second ink layer of a waterproof ink formed so that the washing step are carried out with water can.

Compared with a generation of the recesses by means of etching technology, the described Method several advantages. Thus, when using an etching technique, it is difficult to find a alkali-resistant resist coating which at the same time has good adhesion to the metallic coating. Also, the use of alkaline solutions for demetallization entails the risk of carryover of alkaline residues within the demetallization plant. By contrast, in the case of the production of security elements described here with a washing process, no alkali-resistant resist coating is required. The demetallization is preferably carried out with water, so that the use of alkaline solutions is avoided. Overall, the method described is simple, inexpensive and environmentally friendly and provides high quality and easy to control results through the use of established printing techniques.

Further embodiments as well as advantages of the invention are described below with reference to FIGS explains in their representation on a scale and proportion Play has been omitted in order to increase the clarity.

It demonstrate:

1 3 a schematic representation of a banknote with an embedded security thread and a transfer element glued over a punched opening, in each case according to an exemplary embodiment of the invention,

2 the layer structure of a security element according to an embodiment of the invention in cross-section,

3 in (a) to (f) six intermediate steps in the production of the security element of 2 .

4 a partially cutaway view of the front of a security element according to another embodiment of the invention,

5 a cross section of a modification of the security element of 2 .

6 a plan view of a security element according to another embodiment of the invention,

7 a cross section through the security element of 6 along the line VII-VII,

8th a plan view of a security element according to yet another embodiment of the invention,

9 in (a) to (d) cross sections through the security element of 8th along the line IX-IX, which show intermediate steps in the production,

10 - 12 Security elements according to further embodiments of the invention in cross section,

13 - 14 Further embodiments of security elements according to the invention, in which the introduced motifs are combined with other motifs, which only appear above or below a characteristic envelope temperature, and

15 a cross section through a security element according to the invention.

The invention will now be explained in more detail using the example of a banknote. 1 shows a schematic representation of a banknote 10 that have two security elements 12 respectively. 16 each formed according to an embodiment of the invention. The first security element provides a security thread 12 which is at certain window areas 14 on the surface of the banknote 10 emerges while standing in the intervening areas inside the banknote 10 is embedded. The banknote also has a continuous punched opening 18 on the front of the banknote from the glued transfer element 16 completely covered.

The layer structure and the production of a security element according to the invention, such as the security thread 12 or the transfer element 16 , will now be based on the 2 and 3 explains 2 the layer structure of the security element in cross-section and 3 in (a) to (f) shows six intermediate steps in the production of the security element.

With reference first to 3 (a) is applied to a transparent or translucent plastic film 20 all over an opaque layer 22 a water-soluble ink printed. The printing ink of the opaque layer 22 In the exemplary embodiment, it has a black color shade with a high proportion of pigments, for example carbon black pigments. The ink has the property, with the plastic film 20 not anchored so that it can be removed later with water as a solvent again.

On the opaque color layer 22 is partially a second, waterproof paint layer 24 imprinted, as in 3 (b) shown. The color layer 24 covers the color layer in the applied areas 22 Good, so that they can not be washed off there. For example, the printing ink of the second color layers 24 the first Penetrate ink partially and anchor with the plastic film. The color layer 24 is not full-surface, but with recesses 26 applied in the form of the desired motifs.

For better distinctness, the printing ink of the second color layer 24 have a different color than the first ink. For example, the first ink may have a black color and the second ink a blue color. However, first and second printing inks can also have the same color tone, for example black, but this results in a lower distinctness of the two color layers in the assessment of the print quality 22 and 24 results. The printing ink of the second color layer 24 may also contain machine-readable feature substances, in particular magnetic and / or electrically conductive feature substances.

On the two color layers 22 . 24 then becomes a metallic coating 28 , in the exemplary embodiment aluminum, applied, as in 3 (c) shown. Other, preferably vapor-deposited metals or alloys are used for the coating 28 in question. After metallization becomes the first color coat 22 and the metal layer 28 in the recesses 26 with a suitable solvent, in the embodiment of water removed.

It is exploited that the first ink due to the high pigment content after drying a sublime application of paint on the plastic film 20 forms. The metal layer 28 therefore covers in the recesses 26 the dried color body of the first ink only partially so that it remains accessible in these areas for the solvent. The paint application in the recesses 26 becomes so along with the overlying metal layer 28 washed out. The washing step can also be done with mechanical assistance.

Outside the recesses 26 remains the first color layer 22 washed out, protected by the waterproof second coat of paint 24 , as received in 3 (d) shown. The two color layers 22 . 24 form together with the metal layer 28 an opaque top layer 30 into which the desired motifs are introduced in the form of patterns, characters or codes. At this stage of manufacture, the motifs can already be seen from both sides of the coated plastic film, whereby they appear as negative information in an otherwise metallic appearance or an otherwise black appearance, depending on the viewing direction.

To protect the structured cover layer 30 becomes the coated side of the plastic film 20 with a transparent or translucent plastic carrier 32 and a laminating adhesive 34 laminated, as in 3 (e) shown. The metallic coating 28 is thus protected against mechanical and chemical influences.

On the non-printed or uncoated side is the plastic film 20 then with another plastic carrier 36 previously with a substantially transparent or translucent optically variable effect layer 38 was provided, laminated. In the embodiment, the effect layer 38 by a liquid crystal layer, for example, a cholesteric liquid crystal layer having a color shift effect. Subsequently, the plastic carrier 36 , as in 3 (f) shown by the effect layer 38 separated, and the security element tailored and reworked depending on the application. When used as a security thread in a banknote, the security element is provided, for example, for better adhesion in the paper on both sides with a heat seal adhesive.

Overall, results from the in 3 (a) to (3f) illustrated method steps the security element of 2 , in which the introduced motifs are recognizable from both sides with different optical impression. The security element of 2 can be used as a security thread, for example 12 right in a documentary material, here the paper of the banknote 10 , so that the optically variable effect of the security thread in the subregions 14 appears on the surface of the banknote. The metallic side of the security thread 12 is completely embedded in the paper to reduce the visibility of the security thread on the back of the paper.

In this, as well as the following embodiments is in printing the water-soluble ink 22 No high order volume required, so that it can be applied over the entire surface in a lighter, not opaque color. The insoluble printing ink 24 On the other hand, preference is given to using dark, in particular black, so that a check is carried out on the quality of the insoluble printing ink 24 printed areas is easily possible. This is especially important when printing lettering or number sequences.

Some types of security thread require the correct thread insertion in the paper for the purpose of thread visibility, so that an opaque white layer is printed on one side of the film. The recesses appear more opaque due to the opaque whitening layer as compared to demetalized threads which do not require a laterally correct insertion. Used as a water-soluble ink 22 a white wash, that's the security element on this page transparent recess pattern. For the insoluble printing ink 24 Then choose a color that does not affect the white wash color in the shade too much.

4 shows a partially cutaway view of the front of a security element 40 according to a further embodiment of the invention, wherein between the recesses 26 in the topcoat 30 another printing ink is printed with machine-readable properties. For example, as in 4 shown schematically, with a printing ink having magnetic properties a visually unrecognizable, machine-readable stiffener code 42 between the recesses 26 imprinted to further increase the counterfeit security of the element.

In a respect to 5 explained modification of the security element of 2 is a transparent or translucent plastic film 220 with an opaque top layer 230 provided, which consists of a sequence of initially applied over the entire surface of water-soluble ink 222 , a full surface on the ink 222 vapor-deposited aluminum layer 228 and a portion of the aluminum layer 228 imprinted water-insoluble printing ink 224 consists. The water-insoluble printing ink 224 has a yellow or reddish brown color, so that in interaction with the aluminum layer 228 when viewed from the metallized side here a gold-colored or copper-colored color impression is created.

As related to the 2 and 3 described, the top layer becomes 230 after partial demetalization by washing out the printing ink 222 with a translucent plastic carrier 232 laminated to the printed metal layer 228 to protect against mechanical and chemical influences. Also, the non-printed side of the film 220 with an effect layer 238 Mistake.

Another embodiment of the invention will now be described with reference to FIG 6 and 7 explains 6 a supervision and 7 a cross section through the security element along the line VII-VII of 6 shows.

The security element 50 includes a translucent plastic layer 52 to which, as described above, a structured cover layer 54 is applied. The cover layer 54 consists of identically or differently colored washable and preferably water-soluble inks 56 and 58 , of printed identically or dissimilar insoluble inks 60 and 62 and a metallic coating 64 ,

The printing inks 56 and 58 For example, they can be arranged in different colors, so that in supervision a security element with blocks of different colors 66 respectively. 68 ( 6 ), which may have various transparent recesses in the form of characters, patterns or codes. Also the insoluble printing inks 60 and 62 can be the same or different. For example, the printing ink 60 machine-readable properties in the form of magnetic and / or electrically conductive properties, while the printing ink 62 has no machine-readable properties. In other designs, the insoluble inks 60 . 62 both magnetic properties, but differ for example in the remanence or the coercivity. Also, one printing ink may have hard-magnetic properties, the other printing ink soft-magnetic properties.

The security element 50 also contains a primer layer 70 , on which in the area of the left-over areas of the cover layer 54 more inks 72 and 74 are applied. Also the printing colors 72 and 74 may have the same or different properties and, for example, be opaque or translucent. They may also have the same or different fluorescent feature substances, so that the recesses in the cover layer 54 when illuminated with UV radiation in the corresponding colors fluoresce.

On the opposite side of the plastic layer 52 is the security element 50 with an optically variable effect layer 76 Mistake. In the embodiment, the effect layer is formed by a thermochromic layer which is opaque below a certain Umschlagtemperatur, for example 30 ° C. Above the Umschlagtemperatur is the thermochromic layer 76 colorless or translucent, so that only the underlying information can be seen.

Alternatively, the effect layer 76 be formed in the form of a directionally reflective layer, for example, a translucent layer that generates different color impressions when changing the viewing angle in reflection. Such optically variable properties can be obtained, for example, with interference layer pigments or liquid crystal pigments which are admixed to a transparent binder or a transparent plastic film. In a further variant, the optically variable effect of the effect layer 76 produced by a relief structure, which is embossed a transparent paint or plastic layer in the form of diffraction structures.

The translucent plastic layer 52 can also be provided with a metal layer ent can not be executed over the entire surface or at least partially in the form of a grid with a predetermined grid size and screen ruling. The grid elements can consist of points, lines or other, even irregular, geometric shapes.

From Layer edge to layer edge of the security element can continue a transparent region arranged with electrically conductive properties be, which offers another coding option. In one such a transparent area, For example, in the inset process, and other inks, such as about flag colors, to be arranged.

8th and 9 illustrate another embodiment of the invention, wherein 8th a supervision and 9 in (a) to (d) shows cross sections through the security element along the line IX-IX for intermediate steps in the production of the security element.

The security element 80 has first areas 82 with diffraction structures and transparent recesses 84 , as well as second colored areas 86 with transparent recesses 88 on.

To make the different areas is on a substrate or transfer material of a plastic layer 90 a pre-history 92 applied. In the pre-history 92 a relief structure is imprinted which, in interaction with the subsequently applied metallization in reflection, produces a diffraction-optical image, for example a hologram or a lattice structure, such as a kinegram or a pixelgram.

About the Prägeschicht 92 then becomes a water-soluble ink in individual blocks 94 applied in the form of patterns, characters or codes. The water-soluble printing ink 94 is doing both in the colored areas 86 including their recess areas 88 as well as in the recess areas 84 the diffraction structure areas 82 applied, as in 9 (a) shown.

Subsequently, as in 9 (b) represented, the waterproof ink 96 in the colored areas 86 in the register on the blocks of water-soluble ink 94 imprinted, with the recessed areas 88 the colored areas 86 to be released. In the diffraction structure areas 82 no waterproof ink is applied. Then the whole structure is covered with a metal layer 98 , preferably aluminum, coated as in 9 (c) shown. Instead of aluminum, other metals, such as copper, gold, iron, chromium, nickel, silver, platinum, palladium, titanium, other non-ferrous metals, or suitable alloys for the coating into consideration.

By washing out the water-soluble ink 94 the security element is partially demetallized so that it is in 9 (d) shown structure arises. In the diffraction structure areas 82 In diffraction images of the metallized relief structure can be seen, wherein the recess areas 84 appear transparent. The recesses 88 in the colored areas 86 are visible from both sides.

As described in detail above, the back of the plastic layer 90 subsequently with an in 9 Not shown to provide optically variable effect layer, so that through the recesses 88 formed motives viewed from the back with an optically variable effect in appearance.

10 shows a security element 100 according to a further embodiment of the invention. At the security element 100 is a transparent plastic carrier 116 with an optically variable effect layer 102 , for example in the form of a directionally reflective layer with liquid crystal pigments coated. On this optically variable effect layer 102 is a textured topcoat 104 arranged, as related to the 2 and 3 described from a sequence of initially applied over the entire surface of water-soluble ink 106 , a partially imprinted water-insoluble printing ink 108 and a vapor-deposited metal layer 110 , in particular aluminum.

After partial demetalization by washing out the printing ink 106 in the unprotected areas becomes the topcoat 104 with a translucent plastic carrier 112 by means of a laminating adhesive 114 laminated so that the metal layer 110 is protected against mechanical and chemical influences. Last is the carrier film 116 subtracted and from the optically variable effect layer 102 separated. Depending on the application and the specific design of the effect layer 102 It may be advantageous to protect them subsequently also against mechanical and chemical influences.

The design of the 10 has in particular for the consideration of the back over the embodiments described above, the advantage that between the optically variable effect layer 102 and by the inks 106 and 108 no intermediate layers, such as an adhesive layer or a film, are present. The optically variable effect is therefore particularly evident.

Over the effect layer 102 can also in the embodiment of 10 be arranged a stamping layer. Is the embossed layer between the effect layer 102 and the carrier film 116 , so a release layer is used to a problem-free separation of carrier film 116 and effect layer 102 to enable. Also within the effect layer 102 may be provided embossed motifs.

At the security element 120 of the 11 is a translucent plastic carrier 122 with a pre-history 124 equipped, which may be formed as indicated above. On the pre-history 124 is a textured topcoat 126 arranged, in turn, from a sequence of initially applied over the entire surface of water-soluble ink 128 , a partially imprinted water-insoluble printing ink 130 and an aluminum layer 132 consists. After partial demetalization by washing out the printing ink 128 and laminating the topcoat 126 with a translucent plastic carrier 134 by means of laminating adhesive 136 is the aluminum layer 132 protected against mechanical and chemical influences.

Subsequently, another carrier film 140 with an optically variable effect layer 142 , For example, a directionally reflective layer of liquid crystal pigments on which the cover layer 126 opposite side of the plastic carrier 122 by means of laminating adhesive 144 applied. Then the other carrier film 140 from the effect layer 142 separated. The security element 100 shows next to the visible from the back color shift effect of the liquid crystal layer 142 also from the front an optically variable effect of the embossed motif of Prägeschicht 124 is formed. This embossed motif is in front of the dark background of the printing inks 128 and 130 to recognize well depending on the angle and can therefore serve as an additional authenticity feature.

Another security element according to an embodiment of the invention is in 12 shown. At the security element 150 is first on a translucent plastic carrier 152 full surface of a water-soluble ink 154 imprinted and on the printing ink 154 , also full surface, a metal layer 156 evaporated. After that is on the metal layer 156 a waterproof ink 158 with recesses 160 printed in the form of patterns, characters or codes. The printing ink 158 may be provided with machine-readable feature substances, for example magnetic and / or electrically conductive particles.

In the embodiment, in addition, a further print layer 162 With machine-readable features provided between the recesses 160 the waterproof printing layer 158 is applied. After the partial demetallization by the washing step, an optically variable effect layer present on a carrier film is formed 164 with a laminating adhesive 166 on the security element 150 transferred. Finally, the carrier film is peeled off and the in 12 achieved situation.

When using a water-soluble ink 154 with a white tint, the security element is less visible when embedded in paper from the back. An additional opaque white layer, which has been required for some thread types so far, can therefore be omitted.

13 and 14 show further embodiments of security elements according to the invention, in which the recesses introduced into the opaque cover layer motifs are combined with other motifs, which occur only above or below a characteristic Umschlagtemperatur in appearance. The further motifs can also influence the visibility or the background of the recessed motifs of the cover layer above or below the turnover temperature.

13 shows an inventive security element 170 with a translucent plastic layer 172 , on which a thermochromic liquid crystalline color 174 over the entire surface or, as in the embodiment, only partially arranged in the form of a motif.

The thermochromic liquid crystalline Color shows when heated over the Changeover point a color change, which makes the subject visible on the security element. at Cooling the motif disappears again. The process is reversible and can be repeated as often as you like. Thermochrome liquid crystalline colors are available with a color change range between -30 ° C and 120 ° C with a bandwidth of 0.5 ° C to 30 ° C. For the application in security elements, the envelope area is preferably above the ambient temperature, in particular in the range of 25 ° C to 60 ° C, preferably between 30 ° C and 60 ° C.

On the thermochromic liquid-crystalline color layer 174 becomes a black printing ink 176 attached with recesses in the form of characters, patterns or codes, which may be formed with or without machine-readable feature substances. On the printing ink 176 is a second liquid crystalline layer 178 arranged as an effect layer by means of a laminating adhesive 180 is applied. As already described, the carrier film on which the effect layer 178 first applied, subtracted again after laminating.

A further embodiment of a security element according to the invention 190 is in 14 shown. On the front of the transparent plastic carrier 192 is a cover layer in the manner described above 194 arranged and protected by lamination with another transparent carrier, not shown. On the non-printed side of the plastic carrier 192 is a thermochromic liquid-crystalline color layer 196 arranged all over or only in areas. In addition, a second liquid-crystalline layer 198 as an effect layer over the thermochromic liquid crystal layer 196 arranged, which produces a variable depending on the viewing angle color impression.

In addition to the visible in transmitted light recesses of the cover layer 194 shows the security element 190 Thus, when viewed from the bottom in the reflected light a color shift effect. When heating the security element on the Umschlagtemperatur the thermochromic ink layer 196 a motif becomes recognizable, through the recesses of the cover layer 194 given is. From the other side, the security element shows a metallization to the back cover.

The security elements of 13 and 14 can of course also be provided with luminescent and / or machine-readable properties, for example by means of magnetic and / or electrically conductive feature substances. A combination of visually verifiable, machine-readable and thermochromic properties gives the security element additional counterfeit security. The latter security elements can also be combined with embossing stories.

15 shows a further embodiment of a security element according to the invention 250 in cross section. On the plastic carrier 239 is a waterproof ink 240 applied with recesses. The waterproof ink 240 is preferably a high gloss silver ink. About this printing ink 240 During the manufacturing process, the entire surface becomes a water-soluble printing ink 241 arranged on the waterproof ink 240 well anchored, but not on the plastic carrier 239 , Above the color layer 241 becomes a full-surface another ink 242 arranged. The second color layer 242 may additionally contain machine-readable feature substances. Over the color layers 240 . 241 and 242 becomes a metallic coating 243 , preferably aluminum, applied over the entire surface. If the corresponding structure is treated with water, the layers remain 241 . 242 and 243 just stick to the places that match the color 240 are printed. In the not with the printing ink 240 printed areas become the color layers 241 . 242 and 243 removed by the washing process. This gives a security element with machine-readable properties and transparent recesses, whereby the print layer, which is usually darkened by the machine-readable feature substance, is not visible to the eye. In a further variant, between the printing ink 240 and 241 another layer (not shown) which has fluorescent properties. This layer can be arranged both over the entire surface as well as partially. If the layer is arranged over the entire surface, a security element is obtained in which the recesses appear fluorescent with appropriate illumination.

At the shift 245 it is an optically variable effect layer.

Claims (41)

Security element for security papers, documents of value and the like, with motifs incorporated in the security element in the form of patterns, characters or codes, characterized in that the motifs can be seen from opposite sides with different visual appearance when viewing the security element, the motifs being from a first Side viewed as recesses in an opaque cover layer can be seen, and seen from the second, opposite side through a substantially transparent or translucent optically variable effect layer with an optically variable effect in appearance. Security element according to claim 1, characterized in that that the opaque top layer two over each other arranged color layers, of which a first color layer is soluble in a liquid, and the second color layer is insoluble in the liquid. Security element according to claim 2, characterized in that that the first color layer is water-soluble and the second color layer is waterproof. Security element according to claim 2 or 3, characterized characterized in that the first color layer has a high pigment content having. Security element according to at least one of claims 2 to 4, characterized in that the first color layer subregions having a different color impression. Security element according to at least one of claims 2 to 5, characterized in that the second color coat is based on nitrocellulose, Po lyamid- or PVC-based or formed on a UV-curable Paint based. Security element according to at least one of claims 2 to 6, characterized in that the second color layer machine readable Feature substances, in particular luminescent, magnetic and / or electrically conductive Contains feature substances. Security element according to at least one of claims 2 to 7, characterized in that the second color layer subregions with different color impression and / or partial areas with different having machine-readable feature substances. Security element according to at least one of claims 2 to 8, characterized in that the first and / or second color layer a dark hue, especially black. Security element according to at least one of claims 2 to 9, characterized in that the first and second color layer have congruent recesses, the at least one part form the motifs introduced into the security element. Security element according to at least one of claims 1 to 10, characterized in that the opaque cover layer comprises a metal layer includes. Security element according to claim 10 and 11, characterized characterized in that the metal layer over the two color layers is arranged and with these congruent recesses, the at least part of the introduced into the security element Make up motifs. Security element according to claim 10 and 11, characterized characterized in that the metal layer between the two color layers is arranged and with these congruent recesses, the at least part of the introduced into the security element Make up motifs. Safety element according to claim 13, characterized in that that the second, about the metal layer arranged color layer a yellow, reddish brown or brown color. Security element according to at least one of claims 11 to 14, characterized in that the metal layer of aluminum, Copper, gold, iron, chromium, nickel, silver, platinum, palladium, titanium, a other non-ferrous metal, or an alloy of these metals. Security element according to at least one of claims 1 to 15, characterized in that the effect layer is optically variable Pigments, preferably liquid crystal pigments or interference layer pigments. Security element according to at least one of claims 1 to 16, characterized in that the effect layer is thermochromic, is preferred with a turnover temperature above 25 ° C. Security element according to at least one of claims 1 to 17, characterized in that the effect layer has a diffraction structure, especially in the form of an embossed Relief structure, contains. Security element according to at least one of claims 1 to 18, characterized in that the effect layer is in the form of patterns, Signs or codings is formed. Security element according to at least one of claims 1 to 19, characterized in that the opaque cover layer and the optical Variable effect layer on a support, in particular a transparent or translucent carrier, available. Security element according to claim 20, characterized that the cover layer and the effect layer on opposite Pages of the transparent or translucent carrier are arranged. Security element according to at least one of claims 1 to 21, characterized in that the opaque cover layer with a transparent or translucent protective layer is provided. Security element according to claim 22, characterized that the protective layer at the same time a carrier for the cover layer and the effect layer forms. Security element according to at least one of claims 20 to 23, characterized in that the carrier or the protective layer are provided with further layers, in particular with opaque, translucent or luminescent color layers or with feature layers, have the machine-readable feature substances. Security element according to at least one of claims 1 to 24, characterized in that the security element in addition to the Effect layer has a thermochromic layer below its Enveloping temperature of the introduced motifs when viewing one of the opposite sides hides. A security element according to claim 25, characterized in that the thermochromic layer on the first side of the security element is arranged above the opaque cover layer. Security element according to claim 25, characterized that the thermochromic layer on the second side of the security element arranged between the opaque cover layer and the effect layer is. Security element according to at least one of claims 25 to 27, characterized in that the thermochromic layer by a thermochromic liquid crystal layer is formed, preferably with a Umschlagtemperatur in the range from 25 ° C to 60 ° C, especially preferably in the range of 30 ° C to 60 ° C. Security element according to at least one of claims 1 to 28, characterized in that the security element comprises a security strip, a security thread, a security tape, a patch or a Transfer element for application to a security paper, value document and the like. Security paper for the production of security documents, such as banknotes, ID cards or the like, with a security element according to at least one of the claims 1 to 29 is equipped. Security paper according to claim 30, comprising at least a window area or hole covered with the security element. Value document, such as banknote, identity card or the like, that with a security element according to at least one of claims 1 to 29 is equipped. Document of value according to claim 32, with at least one window area or hole covered with the security element. Use of a security element after at least one of the claims 1 to 29, a security paper according to claim 30 or 31, or a value document according to claim 32 or 33 for securing goods of any kind. Method for producing a security element with motifs in the form of patterns, signs or codes, characterized in that a security element with a superimposed arranged opaque cover layer and a substantially transparent or translucent optically variable effect layer is generated, wherein the motifs are introduced as recesses in the opaque cover layer so they look at the security element of opposite Recognizable sides with different optical appearance are. Process according to claim 35, characterized in that that the opaque topcoat on a transparent or translucent carrier or applied to the optically variable effect layer. Method according to claim 36, characterized that when applying the opaque cover layer, a first, in one liquid soluble, preferably water-soluble Color layer is printed, and on the first color layer areawise a second, in the liquid insoluble, preferably waterproof color layer is printed. Method according to claim 37, characterized in that that a metal layer is applied to the two color layers, is vapor-deposited in particular. Method according to claim 36, characterized that when applying the opaque cover layer, a first, in one liquid soluble, preferably water-soluble Color layer is printed on the first color layer, a metal layer applied, in particular vapor-deposited and then on the metal layer partially a second, insoluble in the liquid, preferably waterproof color layer is printed. Method according to at least one of claims 37 to 39, characterized in that in a washing step, the first Color coat and the above lying metal layer in the not with the second color layer protected Be removed areas, whereby in the opaque cover layer recesses be formed in the form of the motifs. Method according to claim 40, characterized in that that the first color layer of a water-soluble ink and the second color layer is formed from a waterproof ink, and that the washing step is carried out with water.