DE102009007779C5 - A method for producing a visually perceptible without technical aids security feature, security feature for plastic-based value or security document and document with at least one such security feature - Google Patents

Abstract

A method for producing a security feature visually perceptible without technical aids, comprising the following steps: a) providing a first material layer, b) applying a first lacquer to form a second material layer formed by a first lacquer layer at least in partial regions of the first material layer, wherein the first lacquer layer has a Refractive index, which differs from the refractive index of the first material layer by at least 0.1, and partial curing of the first coating and in a first curing step, c) generating a structuring of the first lacquer layer, the structuring of a feature size parallel to the surface of the security feature of at least 10 microns and perpendicular to the surface of the security feature of at least 5 microns, d) applying a second varnish to form a second varnish layer on the first varnish layer and simultaneous complete curing of both varnishes in one second curing step of the first paint, wherein a curing step of the second paint is identical to the second curing step of the first paint, wherein both paint layers are inseparably connected to each other in the second curing step of the first paint and wherein the security feature thus produced is visually perceptible due to refraction of electromagnetic radiation ,

Description

Field of the invention

The invention relates to a method for producing a visually perceptible without technical aids security feature, a visually without technical aids visually perceptible security feature, a method for producing a document with such a security feature and a document with such a security feature.

State of the art

Value or security documents often consist of a plastic body, which is produced by means of joining, in particular by means of lamination, from a plurality of plastic layers. Such value or security documents have a long service life and are better protected against simple paper-based documents due to the more complex production techniques. For further security, in particular the personalized or individualized data introduced into a value or security document, security features are integrated in the document body or subsequently applied to it. In this case, it is particularly preferred if the security feature is located in the same position as the personalized or individualized data, since in case of manipulation or exchange of the personalized or individualized data, the security feature is damaged or destroyed and thus the manipulation is obvious. Personal data is understood here and below to mean personal data, for example name or date of birth of a document holder, and individualized data document-specific data, for example a serial number.

To safeguard value or security documents, security features are often used which have a view dependent on the perspective. Such security features are difficult and not adjustable with commercially available copying systems. It is important here that with simple consideration of the value or security document, an untrained observer can determine the presence and authenticity of the security feature even without technical aids. For this purpose, for example, optically variable colors are used. However, these are only available in a limited number of variations and, in particular, can only be used to a limited extent for securing via personalized or individualized data. Therefore, diffraction structures are very often introduced into value or security documents or subsequently applied to them after the personalization of document blanks. The advantage of holographic security features is the introduction of complex information, for example a complex representation, such as coats of arms or logos.

From the DE10013410A1 is a spatial, diffractive optical effective structure is known, which is produced by a provided with a reflection-enhancing coating surface of a paint or polymer layer. The thickness of such a security element is only about 3 to 10 microns in total. As reflection-enhancing coatings metals, but also dielectric layers, for example TiO ₂ , can be used. The dielectric layers must have a refractive index which is sufficiently different from the lacquer in order to have a reflection-enhancing effect. Disadvantage of such a security element is that structures which are effective diffraction optical, must be made with a precision below the order of the wavelength, which is why for the step of generating the spatial, diffractive optical effective layer must be used according to precise and expensive procedures. Furthermore, suitable illumination from a specific orientation is necessary for viewing diffraction-optically effective structures, which makes the security feature more difficult to verify than, for example, an optically variable color.

To safeguard value or security documents lens structures are often used to achieve tilt image effects. For example, from the German driver's license such a laser-described tilting image is known. The advantage of such structures is the extremely simple verification, which does not require any special lighting conditions for the reconstruction. Furthermore, the lens structure and introduced information spatially must be very closely matched, so that manipulation is extremely difficult.

From the WO2008 / 098753A1 is a high-breaking embossing lacquer is known, which is suitable for the production of micro-optical devices as a security element in value documents. The embossing lacquer according to the invention has at least one organic compound which has at least one polarizable element, so that the refractive index is greater than 1.5. The refractive index of the embossing lacquer may be increased by the addition of nanoparticles. The embossing lacquer is used for the production of security elements, which are equipped in security features in the form of microstructures. Disadvantage of the micro-optical security elements is the necessary precision of the microlenses and the uniformity of all microlenses of a security element and the extreme Registration accuracy between the microlenses and the enlarged microstructures.

From the DE3231460A1 An identity card is known, which is made up of a plurality of plastic layers, wherein at least two adjoining plastic layers have a different transparency and at least one of these layers has depressions, which are at least partially filled by the material of the adjacent layer. The thicknesses of the different transparent layers vary, so that in reflected light a light-shadow effect results, which is reversed in transmitted light. The deforming layer may be provided with a print that plastically deforms in dependence on the depressions, whereby a spatial impression of the printed image can be obtained. Furthermore, the identification card can have a surface relief at the locations of the depressions through them, so that the pattern can be felt as a surface relief. A disadvantage of the method described here for producing a badge that the feature can be introduced only at the time of manufacture of the card body of the badge. A later contribution, for example, after the introduction of personalized data to protect them, or a contribution of personalized or individualized data is not possible. In addition, the feature thus created is totally reflective, highly glossy or dull, so it can not be mounted over other security features or data.

From the DE 10 2004 016 596 A1 is a security element in the form of a multilayer film body known. The film body has a replication lacquer layer and a thin film layer for generating a viewing angle-dependent color shift effect by means of interference. The interface between the replication lacquer layer and the thin film has a first region in which a first relief structure for suppressing the generation of a color shift effect is formed. As a result, the production of security elements is cheapened, in which the color shift effect generated by the thin-film layer is not intended to be provided over the entire surface but only in a pattern region. Furthermore, very high resolutions can be achieved hereby.

From the DE 10 2006 032 660 A1 is a multi-layer body with micro-optics known. The micro-optical structures are applied by intaglio printing. The multilayer body can be a transfer film, a security document or a security document with a transfer film. Advantage of the method is that the cost of register-accurate alignment of only the printing plates to each other and the multi-layer body can then be duplicated in large quantities.

Problem of the prior art and object of the invention

Security features of the type described above can not be used with simple means at any point in the manufacturing and / or personalization process in order to secure value or security documents, in particular the personalized or individualized information incorporated in these documents, against forgery and falsification.

It thus sets itself the task of creating a security feature, which can be easily introduced and easily verified without tools with the naked eye and under any lighting conditions. This security feature should be able to be introduced at any point in the production and / or personalization process of the value or security document in a simple and cost-effective manner in the document, in particular for the protection of personalized or individualized information.

Description of the invention and preferred embodiments

According to the invention the object is achieved by a security feature is created, which is visually perceptible without technical aids. The security feature according to the invention is formed from at least two material layers, wherein the second material layer is a first lacquer layer. This first lacquer layer covers the first material layer at least in partial areas. This covering may extend over the entire surface over the first material layer, over a partial region of the first material layer or over at least two separate partial regions of the first material layer. The coverage may also be a dot pattern, for example. The first lacquer layer has a refractive index difference of at least 0.1 relative to the first material layer. The first lacquer layer has a structuring or represents a structuring. If the first lacquer layer extends over the entire surface over the first material layer, then the structuring of the first lacquer layer is given by a variation of the thickness of the lacquer layer. If the first lacquer layer extends over a plurality of partial regions of the first material layer, then the spatial arrangement of the lacquer layer forms a structuring. The structuring is such that electromagnetic radiation which passes from the first material layer into the first lacquer layer is refracted. The structuring according to the invention has a structure size parallel to the surface (to the main plane of the first material layer) of at least 10 .mu.m. If the structuring is given by a dot pattern, the point size is at least 10 microns, which is understood here by a point, a contiguous, two-dimensionally completed portion of the first lacquer layer. If the structuring is given by a variation of the thickness of the first lacquer layer, then regions with approximately the same thickness have a lateral extent of at least 10 μm. The structuring furthermore has, according to the invention, a structure size perpendicular to the surface of at least 5 μm, preferably between 5 μm and 10 μm. If the structuring is given by a dot pattern, then the dot height is at least 5 μm, preferably between 5 μm and 10 μm. If the structuring is given by a variation of the thickness of the first lacquer layer, regions with different thicknesses have a thickness difference of at least 5 μm, preferably between 5 μm and 10 μm.

The advantages of the security feature according to the invention result from the simple production and the simple verification. Since the security feature according to the invention is visually perceptible due to refraction of electromagnetic radiation, no special lighting conditions are necessary for its observation, as are necessary, for example, in the observation of holograms, which are visually perceptible due to diffraction of electromagnetic radiation. The manufacture of a security feature according to the invention is simpler and more flexible than the security features mentioned above, since neither the high precision required for a diffractive structure nor the relative positioning accuracy required for micro-lens systems is necessary. By producing the security feature by applying a lacquer layer, integration of the security feature according to the invention into an inner layer of a document during production as well as on the surface of a finished document blank, in particular for securing personalization data, is possible.

In a preferred embodiment of the invention, the security feature has a structuring parallel to the surface with a structure size of at least 100 μm.

In a preferred embodiment of the invention, the security feature has a structuring parallel to the surface with a feature size of at least 1 mm.

In a preferred embodiment of the invention, the security feature additionally has a second lacquer layer, which is arranged above the first lacquer layer. The advantage of this embodiment is the protection of the structuring of the first lacquer layer against mechanical stress, in particular protection against abrasion. The second lacquer layer may have a refractive index difference of at least 0.1 relative to the first lacquer layer. Particularly preferably, the second lacquer layer has the same or a similar refractive index as the first material layer. Under similar, a refractive index difference of less than 0.02 is considered. The structuring of the first lacquer layer perpendicular to the surface of the security feature is at least partially, preferably completely, compensated by the second lacquer layer so that the security feature is hardly, preferably not, palpable.

In a preferred embodiment of the security feature, the second lacquer layer has a layer thickness which is less than the structure size of the first lacquer layer. As a result, the structuring of the first lacquer layer of the security feature remains palpable. This embodiment is preferred if even such a thin second lacquer layer significantly improves the performance properties of the security feature, in particular the abrasion resistance.

In a preferred embodiment of the security feature, the second lacquer layer has abrasion-resistant properties. The abrasion-resistant properties are preferably produced by the addition of ZnO and / or SiO ₂ .

In a preferred embodiment of the security feature, the first material layer and the first lacquer layer are transparent.

In a preferred embodiment of the security feature, the first material layer as well as the first and the second lacquer layer are transparent.

In an alternative preferred embodiment of the security feature, the first lacquer layer is translucent and the second lacquer layer is transparent.

In an alternative preferred embodiment of the security feature, the first material layer is opaque or translucent, the first lacquer layer and the second lacquer layer are transparent.

In a preferred embodiment of the security feature, the refractive index of the first lacquer layer is adjusted by the addition of at least one high-index additive by at least 0.1 higher than the refractive index of the first material layer. At least one of the high refractive index additives is selected from the group comprising glass, feldspar, TiO ₂ , ZrO ₂ and diamond. Preferably, a high-index additive nanocrystalline, so smaller with a particle size 100 nm, more preferably with a particle size less than 25 nm.

In a preferred embodiment of the security feature, the first material layer consists of a material selected from the group comprising polycarbonate (PC), polyethylene terephthalate (PET) and its derivatives, polyvinyl chloride (PVC), polypropylene (PP), polyethylene (PE), thermoplastic elastomers ( TPE), paper and glass, and mixtures of these materials. The first material layer may have a thickness of at least 50 μm.

In a preferred embodiment of the security feature, the first material layer is a document blank. A document blank may be a multi-layer composite, for example a multi-layer laminate in which layers of identical or different materials may be present. If it is a document blank made of different materials, the refractive index of the first material layer is considered to be the refractive index of an uppermost transparent layer. The topmost transparent layer may be a lacquer layer.

In a preferred embodiment of the security feature, at least the first lacquer layer contains at least one substance which can be excited to luminesce.

A document according to the invention has at least one security feature visually perceptible without technical aids according to the present invention. Furthermore, the document may have one or more other security features. Examples include guilloche printing, iris printing, optically variable color, laser engraving, luminescence color, hologram, electronic components, for example RF chip and / or display, as well as metameric colors. The document may be a value or security document, a passport, an identity card, a birth certificate, a visa, a driving license, a credit card, a bank card, a company card, a membership card, a vehicle registration document, a banknote, a check, a Act stock, a stamp or a tax sign. The document may be constructed from polycarbonate (PC), polyethylene terephthalate (PET) and its derivatives, polyvinylchloride (PVC), polypropylene (PP), polyethylene (PE), thermoplastic elastomers (TPE), paper, as well as mixtures of these materials.

In a preferred embodiment of the document according to the invention, the security feature visually perceptible without technical aids is arranged on the surface of the document. In particular, the security feature is applied to a document blank, preferably after personalization. To protect the security feature against abrasion, for example, a further layer of material may be disposed over the security feature. The further material layer may be a film of a photopolymer into which a volume hologram is or may be imprinted, or an abrasion protection film.

In a further preferred embodiment of the document according to the invention, the security feature visually perceptible without technical aids is arranged in the interior of the document. For introduction, the security feature can be applied to a layer, for example a film, which is connected to further layers, for example by means of lamination, to form a document. The advantage of this embodiment is given by the fact that information provided by the security feature in the document, for example personalization data introduced by means of laser personalization, can be secured if, for example, the security feature is introduced between two laser-capable films.

• a) Bereitstellen einer ersten Materialschicht
• b) Aufbringen einer durch eine erste Lackschicht gebildeten zweiten Materialschicht zumindest in Teilbereichen der ersten Materialschicht, wobei die erste Lackschicht einen Brechungsindex aufweist, der sich vom Brechungsindex der ersten Materialschicht um wenigstens 0,1 unterscheidet, sowie
• c) Erzeugen einer Strukturierung der ersten Lackschicht, wobei die Strukturierung eine Strukturgröße parallel zur Oberfläche des Sicherheitsmerkmals von wenigstens 10 μm und senkrecht zur Oberfläche des Sicherheitsmerkmals von wenigstens 5 μm aufweist und

wobei das so hergestellte Sicherheitsmerkmal aufgrund von Brechung elektromagnetischer Strahlung visuell wahrnehmbar ist.The method according to the invention for producing a security feature which can be visually perceived without technical aids comprises the following steps:

• a) providing a first material layer
• b) applying a second material layer formed by a first lacquer layer at least in partial regions of the first material layer, wherein the first lacquer layer has a refractive index which differs from the refractive index of the first material layer by at least 0.1, and
• c) generating a structuring of the first lacquer layer, wherein the structuring has a feature size parallel to the surface of the security feature of at least 10 microns and perpendicular to the surface of the security feature of at least 5 microns, and

wherein the security feature so produced is visually perceptible due to refraction of electromagnetic radiation.

The first material layer may be, for example, a plastic film having a thickness between 25 μm and 300 μm made of polycarbonate (PC), polyethylene terephthalate (PET) and its derivatives, polyvinyl chloride (PVC), polypropylene (PP), polyethylene (PE), thermoplastic elastomers (TPE), paper, as well as mixtures of these materials or act around a document blank.

In method step b), a lacquer is applied to the first material layer. By curing the lacquer results in the first lacquer layer, which has a difference in refractive index of at least 0.1 relative to the first material layer.

In method step c), a structuring of the first lacquer layer is produced, which has a structure size parallel to the surface of the security feature of at least 10 μm and perpendicular to the surface of the security feature of at least 5 μm. This structuring can be carried out by applying the lacquer in method step b) in a structured manner, applying the lacquer unstructured in method step b) and patterning it in a subsequent step, or by forming the first material layer in a process between steps a) and b ), so that the first lacquer layer assumes the structuring of the first material layer during the application.

In a preferred embodiment of the method for producing the security feature according to the invention, the application of the first lacquer layer in method step b) is carried out by high-pressure, flat, gravure, through or digital printing on the first material layer.

In a further preferred embodiment of the method according to the invention for producing the security feature, the first lacquer layer is applied in method step b) by means of potting, spray coating or roller coating onto the first material layer.

In a further preferred embodiment of the method for producing the security feature, the printing-technical application of the first lacquer layer takes place with simultaneous production of the structuring according to method step c). Particularly suitable for the production of line patterns is intaglio printing. Particularly suitable for the production of individualized structuring is ink-jet printing.

In a further preferred embodiment of the method for producing the security feature, the first material layer provided in method step a) is first structured by means of reshaping. In particular, all methods of embossing and / or ultrasound treatment of the first material layer may be considered as the method of forming. Subsequently, in method step b), the first lacquer layer is applied, which is structured by structuring the first material layer according to method step c).

In a further preferred embodiment of the method for producing the security feature, the first lacquer layer in method step b) can first be applied unstructured. In a subsequent method step c), the first lacquer layer is patterned by means of photolithographic techniques. Here, in a first embodiment, a lacquer can be applied, which is cured by means of UV light. The curing can be carried out by means of targeted exposure to UV light. Subsequently, the uncured paint is removed, for example, washed off with a solvent. In a second embodiment, a varnish is first applied and cured. The resulting lacquer layer is exposed so that the lacquer can be decomposed and washed away at the exposed areas.

In a further preferred embodiment of the method for producing the security feature, the first lacquer layer is cured during method step c). In particular, in this process step b) a paint is applied unstructured. Subsequently, the structuring is produced according to method step c), for example by impressing a stamping die. Since the paint is not cured, only a very low wear on the stamping tool occurs. For example, while the die is on the lacquer layer, it is thermally cured. Instead of an embossing stamp, a cover film can be applied to the first lacquer layer, which has a structured surface. The structuring of the lacquer layer is produced by molding the structured surface of the cover foil. After application of the cover film, the paint layer is cured and then removed the cover sheet.

In a further preferred embodiment of the method for producing the security feature, a second lacquer layer is applied to the first lacquer layer. The application of the second lacquer layer can be done by printing in high, flat, gravure, through or digital printing, by means of potting, spray coating or roller coating on the first coat of paint.

• u) Aufbringen eines zur Bildung der ersten Lackschicht verwendeten ersten Lackes,
• v) Partielles Härten des ersten Lackes,
• w) Aufbringen eines zur Bildung der zweiten Lackschicht verwendeten zweiten Lackes,
• x) Gleichzeitiges vollständiges Härten beider Lacke.

In a particularly preferred embodiment of the method for producing the security feature, the application of the two lacquer layers comprises the following method steps:

• u) applying a first lacquer used to form the first lacquer layer,
• v) partial curing of the first paint,
• w) applying a second lacquer used to form the second lacquer layer,
• x) simultaneous complete curing of both paints.

For this purpose, the first coating has two curing steps, for example by polyaddition and by radical polymerization. The first hardening step causes the first lacquer to become sufficiently firm so that the introduced structure is not destroyed by the following steps. The second paint has a curing step that is identical to the second curing step of the first paint. This leads to a chemical reaction between the two paints in process step x), so that both paint coats are inseparably bonded together.

In a further preferred embodiment of the method for producing the security feature, a second lacquer layer is applied to the first lacquer layer before the first lacquer layer has hardened. Both layers of paint are then cured in a common curing step.

• A) Erzeugung eines ohne technische Hilfsmittel visuell wahrnehmbaren Sicherheitsmerkmals gemäß der vorliegenden Erfindung, gebildet aus der ersten Materialschicht, der ersten Lackschicht und gegebenenfalls einer zweiten Lackschicht,
• B) Bereitstellen von wenigstens einer weiteren Materialschicht,
• C) Anordnen der Materialschichten übereinander und
• D) Verbinden der Materialschichten zu einem Dokumentenkörper.

A method according to the invention for producing a document with the security feature which can be visually perceived without technical aids preferably comprises the following steps:

• A) production of a security feature visually perceptible without technical aids according to the present invention, formed from the first material layer, the first lacquer layer and optionally a second lacquer layer,
• B) providing at least one further material layer,
• C) arranging the material layers one above the other and
• D) connecting the material layers to a document body.

Process step A) comprises process steps a), b) and c) for producing the security feature according to the invention. In method step B), further material layers are provided from which the document is to be constructed. These can be made of the same material as the first material layer, but they can also consist of different materials. In particular, one of the further material layers may be an inlay made of a thermoplastic elastomer, in particular for embedding electronic components. The first and the further material layers are arranged one above the other according to the layer structure of the document in method step C). In this case, the first material layer is preferably arranged in such a way that the security feature produced in method step A) is arranged between two material layers. In method step D), the layers are permanently connected to one another, for example by means of lamination.

Embodiments of the invention will now be described with reference to the accompanying drawings. The individual figures show:

1 : a security feature in section in schematic representation;

2 : another security feature in section in a schematic representation;

3 a further security feature in section in a schematic representation with a second lacquer layer;

4 a further security feature in section in a schematic representation with a structure having a first material layer;

5 a further security feature in section in a schematic representation with a second lacquer layer, which only partially compensates for the structuring of the first lacquer layer;

6 : another security feature in section in a schematic representation;

7 a further security feature in section in a schematic representation with a second lacquer layer, which has a same refractive index with the first material layer;

8th : Another security feature in section in a schematic representation with a document blank as the first material layer.

In 1 is a security feature 10 shown, which consists of a first layer of material 11 and a first coat of paint 12 is formed. The first coat of paint 12 has a structuring which parallelizes a structure size 15 and perpendicular 16 to the surface of the security feature 10 that is, to a plane that is coplanar with the surface of the first material layer. The structure size 15 parallel to the surface is at least 10 microns. The structure size 16 perpendicular to the surface is at least 5 microns. The first coat of paint 12 forms a dot pattern and may be generated by, for example, ink jet printing. Due to the different refractive indices of the first material layer 11 and the first coat of paint 12 The result is the visual impression of floating drops on the first layer of material 11 ,

In 2 is another security feature 10 illustrated in which on the first material layer 11 a first coat of paint 12 is arranged. The first coat of paint 12 covers the first layer of material 11 at least in the area shown completely. However, the first lacquer layer is structured on the surface and has a structure size in parallel 15 and perpendicular 16 to the surface of the security feature 10 which are 5 μm perpendicular to the surface and 10 μm parallel to the surface. The lacquer layer can also be significantly thicker. Such a security feature can be produced, for example, by applying a uniform lacquer layer and embossing a structuring during the curing of the first lacquer layer. Due to the different refractive indices of the first material layer 11 and the first coat of paint 12 The result is the visual impression of floating drops on the first layer of material 11 ,

In 3 is another security feature 10 illustrated in which over the first material layer 11 a first coat of paint 12 and over the first coat of paint 12 a second coat of paint 13 is arranged. Preferably, the second lacquer layer 13 Abrasion-resistant properties and equalizes the structuring of the first coat of paint 12 completely off, so the security feature 10 is particularly well protected against wear on the surface of a document. Next, such a security feature 10 Even without abrasion-resistant properties are integrated into the interior of a document. With a lamination, the pressure would be even over the security feature due to the smooth surface 10 distributed, so that the structuring of the first coat of paint 12 would not be destroyed. The refractive index of the first lacquer layer 12 For example, it may be at least 0.1 greater than the refractive index of the first material layer 11 and at least 0.1 greater than the refractive index of the second lacquer layer 13 , The result is the visual impression of drops floating in the volume of the material.

In 4 is another security feature 10 in which a structuring into the first material layer 11 , has been introduced for example by means of embossing, milling or by means of ultrasound. The first coat of paint 12 can be applied evenly, the structuring of the first coat of paint 12 results from the structuring of the first material layer 11 , Again, due to the difference in the refractive indices of the first material layer 11 and the first coat of paint 12 the visual impression of drops floating in the volume of the material.

In 5 is another security feature 10 shown in which over the first lacquer layer 12 a second coat of paint 13 is arranged, which is the structuring of the first lacquer layer 12 not completely compensated. As a result, the structuring remains palpable. Is the security feature 10 arranged on the surface of a document, so the structuring can be visually observed not only without technical aids but also felt. In addition to the visual impression, which the in 3 equals a tactile impression that is correlated with the visual impression. In places where an apparent drop can be perceived, a survey is noticeable.

In 6 is another security feature 10 in which the structuring of the first lacquer layer 12 different structure sizes parallel and perpendicular to the surface of the security feature 10 having. According to the invention, the smallest feature size is at least 5 μm perpendicular to the surface. Particularly preferably, the largest structure size perpendicular to the surface is at most 10 μm. As a result, the visual impression of the various drops is different and a displayed pattern can be more complex.

In 7 is another security feature 10 shown in which over the first lacquer layer 12 a second coat of paint 13 is arranged, wherein the second lacquer layer 13 has the same refractive index as the first material layer 11 , The refractive index of the first lacquer layer 12 differs from the refractive index of the first material layer 11 and the second lacquer layer 13 at least 0.1. This creates the visual impression, the subregions of the first lacquer layer 12 float like drops in the volume of the security feature. For example, overlapping structures can be represented.

In 8th is a document 20 shown in which on a first layer of material 11 , which in this case represents a document blank, a first lacquer layer 12 and a second coat of paint 13 , in particular with abrasion-resistant properties, are arranged according to the invention. Here, too, arises due to the refractive index difference between the first lacquer layer 12 and the first material layer 11 as well as the second lacquer layer 13 the visual impression of drops floating in the volume of the document.

Claims (8)

A method for producing a security feature visually perceptible without technical aids, comprising the following steps: a) providing a first material layer, b) applying a first lacquer to form a second material layer formed by a first lacquer layer at least in partial regions of the first material layer, wherein the first lacquer layer has a Refractive index, which differs from the refractive index of the first material layer by at least 0.1, and partial curing of the first coating and in a first curing step, c) generating a structuring of the first lacquer layer, the structuring of a feature size parallel to the surface of the security feature of at least 10 microns and perpendicular to the surface of the security feature of at least 5 microns, d) applying a second varnish to form a second varnish layer on the first varnish layer and simultaneous complete curing of both varnishes in one second curing step of the first paint, wherein a curing step of the second paint with is identical to the second curing step of the first resist, wherein both resist layers are inseparably bonded together in the second curing step of the first resist and wherein the security feature thus produced is visually perceptible due to refraction of electromagnetic radiation. A method for producing a security feature according to claim 1, characterized in that in step b) the first lacquer layer is applied by printing in high-, flat-, gravure-, through- or digital printing, by means of potting, spray coating or roll coating on the first material layer. Method for producing a security feature according to Claim 2, characterized in that the printing-technical application of the first lacquer layer takes place with simultaneous production of the structuring according to method step c). A method for producing a security feature according to claim 1, characterized in that on the surface of the first material layer provided in step a) first by means of forming, for example by embossing and / or ultrasound, a structuring is generated and then in step b) the first lacquer layer is applied, wherein the structuring of the first layer of material and the structuring of the first lacquer layer according to method step c) is generated. Method for producing a security feature according to claim 1, characterized in that the structuring of the first lacquer layer in step c) is effected by means of photolithographic techniques. A method for producing a security feature according to claim 1, characterized in that the first lacquer layer during the process step c) is cured. A document having at least one security feature, wherein at least one security feature is a security feature visually perceptible without technical aids made by the method of any one of claims 1 to 6. A document according to claim 7, characterized in that the document is a value or security document, a passport, an identity card, a birth certificate, a visa, a driver's license, a credit card, a bank card, a company card, a membership card, a vehicle registration document , a banknote, a check, a stock, a stamp or a tax sign.

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