DE102013005937A1 - Method for producing a security element with negative writing - Google Patents

Abstract

The invention relates to a method for producing a security element (1) with negative script (3), comprising the steps: a) producing a first security element sub-element (10) by providing a first carrier substrate (11), applying a first functional layer (12) the first carrier substrate (11), application of a resist layer (30) to the first functional layer (12) in the form of a predetermined pattern (7) with resist areas (33) and cutouts (34) between the resist areas; b) producing a second security element sub-element (20) by providing a second carrier substrate (21), applying a second functional layer (22) to the second carrier substrate (21); c) assembling the first (10) and the second (20) security element sub-element to form a composite (5) in such a way that the resist layer (30) and the second functional layer (22) face each other, and gluing the first (10) and second (20) security element sub-element; d) Separating the second carrier substrate (21) from the bonded composite (5), the second functional layer (22) remaining adhered to the resist areas (33) while forming second functional areas (23), while the remaining areas of the second functional layer (22) ) are separated together with the second carrier substrate (21), whereby second recesses (24) are formed in the second functional layer (22); and e) removing the areas of the first functional layer (12) not protected by resist areas (33) by means of etching in order to form first functional areas (13) and first recesses (14) therebetween, which together with the recesses (34) in the resist layer ( 30) and the second recesses (24) in the second functional layer (22) consisting of a material resistant to etching form the negative writing (3).

Description

The invention relates to a method for producing a security element having two mutually-matched motif layers, in particular motif layers having visible in transmitted light and preferably in incident light sign, a security element obtainable by the method, the trained as a transfer element security element, equipped with the security item of value and a Process for producing such a valuable article.

Valuables, in particular value documents such as banknotes, shares, identity cards, credit cards, certificates, checks and other forgery-prone papers, such as identification documents of various kinds, but also branded goods and packaging of branded goods are often equipped with security elements to secure their authenticity and at the same time as To protect against unauthorized reproduction. The security elements may, for example, take the form of security threads or stickers or any other form insertable or attachable to a valuable article or security paper, a "valuable article" within the meaning of the present invention being any objectionable to counterfeiting, in particular a value document, while a "security paper "Represents the precursor to a value document, which is not yet ready for use.

Security elements are typically multilayer elements with multiple functional layers. Functional layers are generally layers that have any properties that can be detected visually or by machine. Functional layers therefore contain, for example, dyes, luminescent substances, thermochromic substances, liquid crystals, interference pigments, electrically conductive substances, magnetic substances, light-diffractive or refractive structures or combinations thereof. The functional layers are usually designed as geometric or figurative patterns or motifs, d. H. within a layer, there are functional areas with the detectable property (eg, luminescence) and recesses therebetween. If a plurality of functional layers are arranged one above the other, it is generally desirable for the functional areas and the recesses in the individual functional layers to be exactly in register, that is to say in the individual functional layers. H. with high register accuracy, and with contour sharp edges between the functional areas and the recesses are formed one above the other. In this way, one functional layer can be hidden under another, for example magnetic substances under a colored layer, or security elements with multiple functional layers and "negative writing" can be produced.

Negative-type security elements comprise a transparent substrate having at least one non-transparent coating having recesses (the negative writing). These recesses may have any shapes, such as letters, numbers or patterns of any kind, especially line patterns. The term "negative writing" used in this application accordingly comprises recesses of any shape, ie any non-solidity in a non-transparent coating. The more transparent, d. H. the more translucent the carrier substrate is, the more pronounced is the contrast between coated and uncoated areas. In the case of very transparent substrates, the negative writing is clearly recognizable in incident light, with less transparent substrates only in transmitted light. If such a security element with negative writing has two different functional layers, for example a motif in the form of a gold-colored metallic coating and the same motif as the red printing ink, then this motif appears to the viewer golden-colored from one side and red from the other side.

Such multilayer motifs are difficult to imitate due to the required high registration accuracy. In particular, subjects with negative fonts provide good protection against counterfeiting, since in the transmitted light inaccuracies in the production are particularly easily recognizable, and "primitive" counterfeiting attempts, such as copying with color copiers, even for the untrained eye are immediately recognizable.

The tamper-proof is the higher the finer the structures in the functional layers are with the matched-to-each other motifs. Finely contoured structures and forming the perfect register with each other, however, also pose a challenge for authorized manufacturers. A number of methods are known which are intended to enable recesses in a plurality of superimposed functional layers to be registered precisely. H. congruent in all layers, train.

Out WO 92/11142 It is known to produce negative fonts in functional layers by means of heat-activatable printing inks. The printing inks are printed in the form of the desired negative writing under the functional layers and contain waxes or intumescent additives which soften when heated or split off a gas and thereby produce foam structures. This reduces the adhesion in the areas which can be printed with the activatable ink, and the functional layers can be mechanically removed in these areas.

DE 10 2007 055 112 discloses a method for register-containing, ie congruent, formation of a negative writing in a plurality of functional layers with the aid of a printing ink printed in the form of the negative print to be formed under the functional layers, which contains a constituent which causes a process on irradiation or upon heating or on contact with a washing liquid As a result, the ink exerts a force on the overlying coating which causes the coating to break. This force can be exerted by a gas generated from constituents of the printing ink when they come into contact with washing liquid, irradiated and / or heated, or by a swelling agent in the printing ink, which swells upon contact with a washing liquid. Once the multilayer coating has been broken, it is relatively easily accessible for washing with washing liquid.

The methods mentioned work satisfactorily, as long as no very fine structures are to be formed. A method for providing congruent patterns or motifs with high contour sharpness and registration accuracy is in WO 2010/015384 A2 described. The basic idea is to use a stickable resist layer to form congruent patterns in two functional layers. For this purpose, a resist layer in the form of the desired pattern is applied to a first functional layer. The pattern is exactly reproduced in the first functional layer by removing the non-resist protected areas of the first functional layer. Subsequently, the pattern in the second functional layer is reproduced by adhering the second functional layer to the resist. The bonding takes place only in the areas in which the second functional layer has contact with the resist. The non-bonded regions of the second functional layer are then removed, while the bonded regions can not be removed, whereby an exact reproduction of the pattern of the resist layer and the first functional layer is produced in the second functional layer.

That in the WO 2010/015384 A2 described method is associated with the fact that the thermoplastic resist used must be tack free at room temperature. Since the step of adhering the functional layers by means of the resist can not be closely related to the pressure of the thermoplastic resist, the possibility of using crosslinking adhesive systems is considerably limited. This results in a resistance of the resist to solvents. In particular, solvents which are used in the step of printing the thermoplastic resin used in each case lead to a dissolution of the polymer. As a result, overprinting with corresponding solvent-containing systems entails considerable swelling of the thermoplastic resin despite the functional layer transferred in the transfer step. Furthermore, under certain circumstances damage to possibly in the functional layers, z. As metallizations, embossed structures. In addition, there remains a permanent impermanence to individual solvents on the layer composite obtained.

Proceeding from this, the object of the invention is to provide a method for the production of security elements which is improved over the above prior art and which makes it possible to form congruent patterns or motifs in two superimposed layers at least partially.

The object of the present invention is, in particular, to provide a security element having two motif layers with corresponding patterns or motifs which have a high register accuracy, wherein the security element has improved resistance and, with regard to its production, greater process reliability.

A preferred object of the present invention is to provide a security element having two metallizations each having an embossed structure, wherein the metallizations are in the form of two motif layers with corresponding patterns having high register accuracy and improved durability and with respect to their production have greater process reliability.

This object is achieved by the manufacturing method, the security element and the transfer material with the features according to the independent claims. Further developments of the invention are the subject of the dependent claims.

Summary of the invention

• 1. (First aspect of the invention) A method for producing a security element with negative writing for a security paper or a valuable article, in particular a value document, comprising the following steps:
• a) producing a first security element partial element
• a1) providing a first transparent or translucent carrier substrate,
• a2) applying a first functional layer to the first carrier substrate or to a previously applied intermediate layer,
• a3) applying a resist layer to the first functional layer in the form of a predetermined pattern with resist areas and recesses between the resist areas,
• b) producing a second security element partial element
• b1) providing a second carrier substrate,
• b2) applying a second functional layer to the second carrier substrate or to a previously applied intermediate layer,
• c) assembling the first and second security element partial elements into a composite in such a way that the resist layer and the second functional layer face each other, and gluing the first and second security element partial elements, preferably under elevated pressure and elevated temperature,
• d) separating the second carrier substrate from the bonded composite, wherein the second functional layer adheres to the resist regions while forming second functional regions, while the remaining regions of the second functional layer are separated together with the second carrier substrate, whereby second recesses are formed in the second functional layer , and
• e) removing the areas of the first functional layer not protected by resist areas by means of etching to form first functional areas and first recesses therebetween, which together with the recesses in the resist layer and the second recesses in the second functional layer consisting of an etching resistant material Negative writing form.
• 2. (Preferred embodiment) The method according to paragraph 1, wherein the first security element subelement is produced by
• Providing the first carrier substrate,
• Applying a first embossing lacquer layer as an intermediate layer to the first carrier substrate,
• Applying a first metallization as the first functional layer to the first embossing lacquer layer,
• Embossing the first embossing lacquer layer before or after the application of the first metallization, and
• - Applying the resist layer on the first metallization, wherein the resist layer has resist areas and recesses or in their resist areas and recesses are formed.
• 3. (Preferred embodiment) Method according to paragraph 1 or 2, wherein the second security element sub-element is made by
• Providing the second carrier substrate,
• Applying a second embossing lacquer layer as an intermediate layer to the second carrier substrate,
• Applying a second metallization as a second functional layer to the second embossing lacquer layer,
• Embossing the second embossing lacquer layer before or after the application of the second metallization.
• 4. (Preferred embodiment) The method according to any one of paragraphs 1 to 3, wherein the second functional layer made of nickel, chromium, silver or gold or of a nickel alloy, a chromium alloy, a silver alloy, a gold alloy or a formed against etching resistant aluminum alloy.
• 5. (Preferred Embodiment) The method according to any one of paragraphs 1 to 4, wherein the first functional layer is formed of aluminum.
• 6. (Preferred Embodiment) Method according to one of paragraphs 1 to 5, wherein the second functional layer is formed of a magnetic properties having metallization, in particular nickel.
• 7. (Preferred Embodiment) The method of paragraph 6, wherein the second functional layer is a metallization of nickel and the second functional regions are adapted to provide magnetic encoding.
• 8. (Preferred Embodiment) The method according to paragraph 7, wherein the second functional areas comprise a structure obtainable in particular by embossing, which is adapted to provide a high-resolution magnetic coding.
• 9. (Second aspect of the invention) A negative-type security element for affixing to or at least partially incorporating into a security paper or a valuable article, in particular a value document obtainable by a method according to any one of paragraphs 1 to 8.
• 10. (Third aspect of the invention) Transfer material for transferring security elements to a security paper or a valuable article such as a value document, wherein the transfer material has a plurality of security elements according to paragraph 9 designed as transfer elements.
• 11. (Fourth Aspect of the Invention) A method of manufacturing a security paper or a valuable article, such as a value document, in which a security element according to paragraph 9 is applied to or at least partially incorporated in a security paper substrate.

Detailed description of the invention

Similar to the one in the WO 2010/015384 A2 According to the invention (hereinafter referred to as "document D1"), an adhesive resist layer is used in order to form congruent patterns in two functional layers, in particular metallizations train. For this purpose, a resist layer in the form of the desired pattern is applied to a first functional layer.

In the method described in D1 for generating a two-sidedly matched metallization, the following steps are carried out:

Step 1: Provide an embossing lacquer layer (reference number 15 in 2a the D1).

Step 2: Provide an aluminum metallization (reference number 12 in 2a the D1).

Step 3: Provide a resist layer (reference number 30 in 2a the D1).

Step 4: Demetallization by Etching (see the 2a and 2 B D1, in particular the metallization obtained after the demetallization step 12 in 2 B ).

Step 5: Making a metal donation sheet (see 2c the D1).

Step 5.1: Provision of an embossing lacquer layer (reference number 25 in 2c the D1).

Step 5.2: Provide a non-adherent aluminum metallization (reference number 22 in 2c the D1).

Step 6: Assembly of the resist layer (reference number 30 in 2 B D1) with the non-adherent metallization (reference number 22 in 2c D1) under increased pressure and elevated temperature to thereby form a composite (reference number 5 in the 2d the D1).

Step 7: Step of the separation winding in which the two connected security element sub-elements are pulled apart so as to form a two-sidedly matched metallization (reference number 1 in 2e D1).

In the procedure described in document D1, the resist lacquer applied in step 3 must still be embossable and tacky under the influence of temperature in step 6. One of the consequences of this circumstance is that the choice of suitable adhesives is subject to considerable restrictions. In a simple manner, the process sequence described in D1 can not be changed because, for example, in a demetallization by means of etching, which has been postponed to a later method step, the exposed aluminum glued onto the resist in step 6 (reference number 22 in the 2d the D1) would be etched away.

The present invention is based on the idea of transferring metals or metal alloys other than aluminum from an embossing lacquer layer which can not be etched or demetallized under the conditions under which aluminum is demetallizable. Such a durable metal may be patterned by the print pattern of the resist or adhesive and will not be damaged under process conditions by which ordinary aluminum metallization is removed.

The advantages of the invention will be explained in more detail below with reference to a preferred embodiment in conjunction with the accompanying drawings, in the representation of a scale and proportionate reproduction has been omitted in order to increase the clarity.

Show it:

1 an inventive security element in transparent view,

2a - 2e the procedure in the manufacture of a security element according to the invention, illustrated in sections through the security element of 1 along the line A-A '.

1 shows a security element according to the invention 1 in a view in transmitted light. The security element 1 has at least the following layers: a transparent substrate 11 , a first and a second functional layer (motif layers), and a resist layer bonding the first and second functional layers. The two motif layers have the same size and shape in the embodiment and cover the carrier substrate 11 only partially. Of course, the motif layers can also cover the carrier substrate over the entire surface. Additionally, one of the motif layers may only partially cover or partially overlap the other motif layer.

In the in 1 shown embodiment of the security element according to the invention, the two motif layers form a triangular pattern 7 from lines 4 , where the lines 4 are formed from the functional areas of the functional layers (motif layers) bonded by means of resist. The lines 4 be through recesses 3 separated, with the recesses 3 be formed by the congruent recesses in the functional areas and the resist layer. The lines 4 vary in width y, making a sub-pattern when viewed through the security element 7 ' becomes perceptible, in the embodiment shown another triangle.

Of course, the functional areas do not necessarily have to be in the form of parallel lines, but can have any other shapes.

Which subject a viewer perceives in the front-side incident light view and in the rear incident light view depends on the special design of the functional areas of the first and the second functional layer.

2 illustrates the process flow in the manufacture of a security element according to the invention 1 , Shown is a section along the line AA of in 1 illustrated security elements. The sequence of layers is merely exemplary.

2a shows a first security element subelement 10 consisting of a first carrier substrate 11 , For example, a film of polyethylene terephthalate (PET), an embossing lacquer layer applied thereto 15 with embossed diffraction structure 15 ' with an aluminum metallization. The aluminum metallization forms a first functional layer 12 on the turn a layer 30 Resist paint in the form of a pattern with resist areas 33 and recesses 34 printed in between. The diffraction structure 15 ' sits in the functional layer as a diffraction structure 12 ' continued.

2 B shows a section through the with the first security element subelement 10 to be combined second security element subelement 20 , The second security element subelement 20 consists of the second carrier substrate 21 , the second functional layer 22 and an embossing lacquer layer 25 between. In the embossing lacquer layer 25 is a diffraction structure 25 ' imprinted, located in the second functional layer 22 as a diffraction structure 22 ' continues. At the second functional layer 22 it is a nickel metallization. The embossing lacquer 25 was before applying the metallization 22 washed off with an aqueous surfactant solution, so that the metallization 22 badly adheres to the embossing lacquer.

2c shows how the first security element subelement 10 out 2a and the second security element subelement 20 out 2 B to a composite 5 be assembled.

The two sub-elements are pressed together, resulting in the diffraction structure 22 ' the second functional layer 22 into the resist areas 33 transmits because it is the resist used is a deformable resist. By means of the resist areas 33 the first security element subelement and the second security element subelement are glued together.

The compression of the two security elements sub-elements can be one or more stages, d. H. the two sub-elements are preferably pressed together at elevated temperature in a heat roller with a (single-stage compression) or more so-called calender rolls (multi-stage compression), or but the two sub-elements are pressed against each other at several heat rollers, each equipped with one or more so-called calender rolls ( multi-stage compression). The multi-stage compression can, depending on the particular embodiment, lead to a particularly strong connection of the security element sub-elements. When using several heating rollers and temperature profiles can be realized during compression.

After bonding and optionally after a certain waiting time for cooling and for stabilizing the adhesive bond, the second carrier substrate 21 and the second embossing lacquer layer 25 deducted, for example by separation winding. The result is in 2d shown. With the first security element subelement 10 only the areas were glued 23 the second functional layer 22 that with resist areas 33 were in contact. These areas form the second functional areas 23 which is an exact reproduction of the pattern of the resist areas 33 represent. The remaining areas of the second functional layer 22 were together with the second carrier substrate 21 and the embossing lacquer layer 25 deducted.

2e shows the layer structure after treatment with an etchant. The etching did not make them through resist areas 33 protected areas of the first functional layer formed by an aluminum metallization 12 removed while passing through resist areas 33 protected areas of the first functional layer 12 were preserved and the first functional areas 13 form. The first functional areas 13 represent an exact reproduction of the pattern of the resist areas 33 In addition, the second functional areas formed by nickel metallization remained 23 obtained during treatment with an etchant

The areas 13 . 33 and 23 are each exactly congruent and form in the representation of 1 the lines 4 , The recesses 3 between the lines 4 are also exactly congruent and are through the recesses 14 in the first functional layer 12 the recesses 34 in the resist layer 30 and the recesses 24 in the second functional layer 22 educated.

The lines 4 (through the first functional areas 13 , the resist areas 33 and the second functional areas 23 are formed) are in the in 2 illustrated embodiment each carrier a diffraction structure. The diffraction structures may be, for example, hologram structures, wherein preferably in the first functional areas 13 and the second functional areas 23 different hologram structures are present. In this case, a viewer recognizes in the transmitted light view the in 1 shown line pattern, in the front side incident light view, one considers the side of the first carrier substrate 11 as the front, the hologram of the first functional layer 12 , and in the back elevational view, the hologram of the second functional layer 22 ,

As a second security element sub-element, for example, a hot stamping foil can be used. In this case, in the case of the separation winding, only the second carrier substrate would be used 21 are withdrawn while the embossing lacquer layer 25 on the formed security element 1 would remain. It can also serve as a protective layer. In general, the provision of a protective layer (not shown in the figure) on the second functional areas or the second functional layer is useful, in particular therefore z. B. the in 2e shown diffraction structure 22 ' or the impression of the diffraction structure 25 ' in the functional layer 22 covered and is therefore inaccessible to counterfeiting.

A particular advantage of the example on the basis of 2a to 2e described manufacturing method according to the invention is that in terms of the formation of the resist layer 30 suitable adhesives have no restrictions. As adhesives come z. B. typical laminating adhesive in question. Adhesives are advantageously used which have good printability and good metal adhesion.

It is preferred that the viscosity at room temperature after bonding is so high that an uncontrolled flow or detachment of the adhesive from one of the two functional layers or metallizations is unlikely. Both solvent-based and solvent-free adhesives can be used. The adhesives can be one-component or two-component. Furthermore, it is preferred that the adhesive used after curing is so stable that the diffraction or embossing structures transferred from the functional layers or metallizations into the resist areas no longer flow and are stable with respect to the pressures and solvents used in subsequent process steps.

The requirement for typical adhesives in the state immediately after physical drying is to be tack free at room temperature. This requirement does not apply to cross-linking adhesives. For this reason, it is particularly advantageous to use crosslinking adhesives to form the resist layer. In this way, the risk of destruction of once formed diffraction or embossing structures in subsequent process steps can be significantly reduced.

In the step of compressing the two security element partial elements, the temperature and the pressure in the laminating gap can be chosen to be significantly lower compared with the process based on thermoplastic resist coating described in document D1. Due to the significantly milder conditions in the laminating gap results in view of the selection of suitable substrates, a higher degree of freedom. In addition, the milder conditions in the laminating gap lead to an improved impression quality of the diffraction or embossing structures transferred from the functional layers or metallizations into the resist areas.

To carry out the production method according to the invention, the physical properties of the first functional layer and those of the second functional layer are coordinated so that the second functional layer is not damaged in the step of removing the first functional layer, for example by means of etching. The first functional layer is advantageously an aluminum metallization. To form the second functional layer z. B. metallizations of nickel, chromium, silver or gold or metallizations of a nickel alloy, a chromium alloy, a silver alloy, a gold alloy or an etching resistant aluminum alloy.

In the choice of nickel as the metallization, the product obtainable by the process according to the invention additionally contains magnetic properties, so that a magnetic coding can be provided in the product. Therefore, the choice of a nickel metallization to form the second functional layer is particularly preferred. Due to the diffraction or embossing structure of the nickel metallization, such a functional layer can in particular provide a high-resolution magnetic coding. Will that be in the 2e shown security elements applied to a value-document substrate in such a way that the functional areas formed of nickel 23 the value document substrate facing and the functional areas formed of aluminum 13 facing the viewer of the value document are responsible for the magnetic coding, formed of nickel functional areas 23 hidden for the viewer when viewing the value document in incident light.

In a further advantageous variant of the in the 2e shown security elements are the functional areas 23 formed from a resistant to etching aluminum alloy and the functional areas 13 made of aluminum. In this way, when viewing the security element in both front-side reflected light, as well as in the rear reflected light, the impression of an identical metallic color can be ensured.

In a further advantageous variant of the in the 2e shown security elements are the functional areas 23 made of copper or gold and the functional areas 13 made of aluminum. In this way, when viewing the security element in the front reflected light on the one hand and in the rear reflected light on the other hand different colored impressions can be caused.

The carrier substrate of the security element partial elements which can be used according to the invention is preferably a film, for example made of polypropylene, polyethylene, polystyrene, polyester, in particular polycarbonate or polyethylene terephthalate. Transparent or translucent films are particularly preferred. When using such films, the register-formed recesses in the individual functional layers can be clearly recognized as negative writing.

The application of the functional layers is carried out by known methods that are suitable for the respective functional layer, for example by physical vapor deposition (PVD) in metals. The application can be made over the entire area or only in partial areas.

The functional layer can be formed directly on the carrier substrate, or one or more intermediate layers can be provided. For some functional layers, intermediate layers are absolutely necessary, for example if the motif of the functional layer is a metallized hologram, kinegram, pixelgram or another metallized diffraction structure. In such a case, first an embossing lacquer layer is applied and embossed into the embossing lacquer layer, before or after the metallization, the desired diffractive structure. In the case of liquid-crystal layers as well, an intermediate layer is generally required which ensures a suitable orientation of the liquid crystals. Suitable orientation layers can be, for example, embossed lacquer layers embossed diffractive structures. Alternatively, if appropriate, the carrier film can also be suitably treated.

It is preferred that at least one of the functional layers is a metallized diffraction structure, such as a metallized hologram. Particularly preferably, both functional layers metallized diffraction structures, such as. B. metallized holograms. When holograms are used in the following, it will be understood that the same applies to other diffraction structures and refractive structures, as well as to so-called "matt structures" (lattice images with achromatic grating areas), as described, for example, in US Pat. B. in the WO 2007/107235 A1 are defined and described (see in particular claim 1).

In principle, the holograms or structural information in the functional layers of a security element according to the invention can be the same or different. Materials for embossing lacquer layers are known to a person skilled in the art. Suitable embossing lacquers are disclosed in, for example DE 10 2004 035 979 A1 , which discloses heat sealing lacquers which can be used equally as embossing lacquer

The resist is preferably applied in the form of the desired pattern, for example printed. The person skilled in the art suitable printing methods are known.

In the step of removing the non-resist protected areas of the first functional layer by means of etching, for example, by etchant, such as alkalis or acids, take place. Suitable methods are known to the person skilled in the art.

The negative writing can form, for example, an encoding or a geometric or figurative motif.

In the step of separating the second carrier substrate from the bonded composite, e.g. B. by isolation winding, the carrier substrate of the second security element sub-element is separated together with parts of the functional layer of the second security element sub-element. Therefore, it is necessary that the functional layer has only a slight adhesion to the carrier substrate.

The required low adhesion force is already achieved in many functional layer materials, in particular metallizations, by omitting adhesion-promoting measures between the carrier substrate and the functional layer. The meeting of adhesion-promoting measures between the individual layers of a security element is otherwise customary, and the corresponding provisions are known to a person skilled in the art.

If the adhesive force between the carrier substrate and the functional layer is too high, it can be reduced by treating the carrier substrate with suitable additives. For example, the carrier substrate with water and / or Solvents are washed off with or without suitable additives. Suitable additives are, for example, surface-active substances, defoamers or thickeners. Additives can also be introduced into the carrier substrate itself. Alternatively, adhesion-reducing layers can be provided under the functional layer. For the adhesion reducing layers, materials are selected on the surfaces of which, as is generally known, a relatively poor adhesion occurs, for example siliconizations, layers containing release additives (eg Byk 3500), waxes, cured UV coatings, metallizations, untreated films such as e.g. , Eg PET. By matching the surface energy ratios of the carrier substrate or the adhesion-reducing layer and the functional layer to be detached, an easy detachability of the functional layer can be achieved and thus the desired pattern can be generated in the functional layer of the second security element partial element.

The same applies to any intermediate layers present between the carrier substrate and the functional layer, for example embossing lacquer layers for a hologram. If such an embossing lacquer layer or other intermediate layer is to be taken off together with the carrier substrate, the adhesive force between the intermediate layer and the functional layer, ie for example between the embossing lacquer layer and a metallization applied thereon, must be correspondingly low. If the adhesive force is too high, the intermediate layer should be treated with the above-mentioned additives or an adhesion-reducing layer should be provided.

If a treatment of the carrier substrate or an intermediate layer with adhesion-reducing additives is carried out, residues of the additives can remain on the functional layer after the carrier substrate or the intermediate layer has been separated off. These can normally be washed away simply with an aqueous solution whose pH is suitably adjusted and which may optionally also contain surfactants. Even a laundry with solvents is possible. In persistent cases, high-pressure nozzles and / or mechanical support (felts, brushes) can be used, but this is usually not necessary. Small additive residues can also be "burned away" by means of a corona treatment. Moreover, in many cases can be completely dispensed with a removal of additive residues. Suitable formulated conformal coatings can also adhere adequately to "additive-loaded" functional layers.

The security elements according to the invention can be in the form of transfer materials, i. H. Films or tapes are provided with a variety of finished and prepared for the transfer of security elements. In the case of a transfer material, the layer structure of the later security element is prepared on a carrier material in the reverse order in which the layer structure is later to be stored on a valuable object, wherein the layer structure of the security element in continuous form or already in the final outline form used as security element on the Carrier material can be prepared. The transfer of the security element on the object of value to be secured by means of an adhesive layer, which is typically provided on the transfer material, but can also be provided on the object of value. Preferably, a hot melt adhesive is used for this purpose. If the security element is prepared in an endless form, an adhesive layer can be provided for transfer either only in the areas of the security element to be transferred, or the adhesive is activated only in the areas to be transferred. The carrier material of the transfer elements is usually deducted from the layer structure of the security elements during or after their transfer to the valuable article. In order to facilitate the detachment, a separating layer (release layer) can be provided between the carrier material and the part of the security elements to be detached. Optionally, the carrier material can also remain on the transmitted security element.

The security elements according to the invention can be used to authenticate goods of any kind. Preferably, they are used to authenticate value documents, for example banknotes, checks or identity cards. In this case, they can be arranged on a surface of the value document or be completely or partially embedded in the value document. With particular advantage they are used in value documents hole hole hole. In this case, the advantages of the security elements according to the invention with transparent carrier substrates and from both sides of the value document to be considered, carefully matched motifs, can be particularly beautiful. Even negatives with the finest structures and sub-patterns can be clearly recognized in transmitted light. You are in the achievable according to the invention precision of a counterfeiter practically imitated. A detachment of the security elements in order to transfer them to another valuable article, is practically not possible because the security elements according to the invention always contain at least two adhesive layers, ie they contain an adhesive resist layer and are connected with an adhesive layer with the valuable object to be secured. For the bonding of the security element to the object of value, use is made of an adhesive whose chemical and physical properties correspond to the resist in the layer structure of the Security element is similar, during stripping attempts, the layer structure of the security element is always destroyed.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 92/11142 [0007]
• DE 102007055112 [0008]
• WO 2010/015384 A2 [0009, 0010, 0015]
• WO 2007/107235 A1 [0058]
• DE 102004035979 A1 [0059]

Claims (11)

Method for producing a security element ( 1 ) with negative writing ( 3 ) for a security paper or a valuable article, in particular a value document, comprising the following steps: a) producing a first security element subelement ( 10 by a1) providing a first transparent or translucent carrier substrate ( 11 ), a2) applying a first functional layer ( 12 ) on the first carrier substrate ( 11 ) or on a previously applied intermediate layer ( 15 ), a3) applying a resist layer ( 30 ) to the first functional layer ( 12 ) in the form of a predetermined pattern ( 7 ) with resist areas ( 33 ) and recesses ( 34 ) between the resist areas, b) producing a second security element partial element ( 20 b1) providing a second carrier substrate ( 21 ), b2) applying a second functional layer ( 22 ) on the second carrier substrate ( 21 ) or on a previously applied intermediate layer ( 25 ), c) assembling the first ( 10 ) and the second ( 20 ) Security element subelement to a composite ( 5 ) such that the resist layer ( 30 ) and the second functional layer ( 22 ) and bonding the first ( 10 ) and second ( 20 ) Security element partial element, preferably under elevated pressure and elevated temperature, d) separating the second carrier substrate ( 21 ) of the bonded composite ( 5 ), wherein the second functional layer ( 22 ) with formation of second functional areas ( 23 ) at the resist areas ( 33 ), while the remaining regions of the second functional layer ( 22 ) together with the second carrier substrate ( 21 ), whereby in the second functional layer ( 22 ) second recesses ( 24 ) and e) removing the non-resist areas ( 33 ) protected areas of the first functional layer ( 12 ) by etching to first functional areas ( 13 ) and first recesses ( 14 ) in between, which together with the recesses ( 34 ) in the resist layer ( 30 ) and the second recesses ( 24 ) in the second, consisting of a resistant to etching material material layer ( 22 ) the negative writing ( 3 ) form. The method of claim 1, wherein the first security element subelement ( 10 ) is prepared by - providing the first carrier substrate ( 11 ), - application of a first embossing lacquer layer ( 15 ) as an intermediate layer on the first carrier substrate ( 11 ), - application of a first metallization ( 12 ) as the first functional layer on the first embossing lacquer layer ( 15 ), - embossing of the first embossing lacquer layer ( 15 ) before or after the application of the first metallization ( 15 ), and - applying the resist layer ( 30 ) on the first metallization ( 12 ), wherein the resist layer has resist areas ( 33 ) and recesses ( 34 ) or in its resist areas ( 33 ) and recesses ( 34 ) are formed. Method according to claim 1 or 2, wherein the second security element subelement ( 20 ) is prepared by - providing the second carrier substrate ( 21 ), - application of a second embossing lacquer layer ( 25 ) as an intermediate layer on the second carrier substrate ( 21 ), - applying a second metallization ( 22 ) as a second functional layer on the second embossing lacquer layer ( 25 ), - embossing the second embossing lacquer layer ( 25 ) before or after the application of the second metallization ( 22 ). Method according to one of claims 1 to 3, wherein the second functional layer ( 22 ) is formed of nickel, chromium, silver or gold or of a nickel alloy, a chromium alloy, a silver alloy, a gold alloy or an etching-resistant aluminum alloy. Method according to one of claims 1 to 4, wherein the first functional layer ( 12 ) is formed of aluminum. Method according to one of claims 1 to 5, wherein the second functional layer ( 22 ) is formed from a magnetic properties metallization, in particular nickel. Method according to claim 6, wherein the second functional layer ( 22 ) is a metallization of nickel and the second functional areas ( 23 ) are adapted to provide a magnetic coding. Method according to claim 7, wherein the second functional areas ( 23 ) have a structure, in particular by embossing, which is adapted to provide a high resolution magnetic coding. Security element ( 1 ) with negative writing ( 3 ) for attachment to or at least partial incorporation into a security paper or a valuable item, in particular a value document obtainable by a method according to one of claims 1 to 8. Transfer material for transferring security elements to a security paper or a valuable article such as a value document, wherein the transfer material comprises a multiplicity of security elements designed as transfer elements ( 1 ) according to claim 9. Method for producing a security paper or a valuable article, such as a value document, in which a security element ( 1 ) according to claim 9 applied to a security paper or valuable object substrate or at least partially introduced therein.

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