CN109863036B

CN109863036B - Security element with optically variable transmission element

Info

Publication number: CN109863036B
Application number: CN201780065473.1A
Authority: CN
Inventors: M.法伊弗
Original assignee: Giesecke and Devrient GmbH
Current assignee: Giesecke and Devrient GmbH
Priority date: 2016-11-07
Filing date: 2017-10-27
Publication date: 2020-10-23
Anticipated expiration: 2037-10-27
Also published as: DE102016013242A1; WO2018082806A1; CN109863036A; EP3535135A1

Abstract

The invention relates to a security element consisting of an interference-capable multilayer structure consisting of at least one reflective layer (3), at least one partially transparent layer (1) and at least one dielectric layer (2) arranged between the reflective layer and the partially transparent layer. According to the invention, in a first region of the security element, at least one reflective layer (3) is designed to be transparent, for example in the form of a grating or partially reflective, wherein a translucent, preferably opaque, coating (7) is applied to the reflective layer at least in the first region, said coating being designed in the form of information. The security element here exhibits a different appearance in top view than in perspective view, as viewed through the partially permeable layer.

Description

Security element with optically variable transmission element

The invention relates to a security element made of an interference-capable multilayer structure consisting of at least one reflective layer, at least one partially transparent layer and at least one dielectric layer arranged between the reflective layer and the partially transparent layer.

Such security elements are known, for example, from WO 2009/149831 a 2. The security element additionally has a plurality of openings in the reflective layer in the first region and at least one opening or a plurality of openings in the partially permeable layer in the second region. The second region is arranged at least partially within the first region, and the total area of the at least partially arranged second region within the first region is smaller than the total area of the first region. The security element thus exhibits a different appearance in top view than in perspective view, as seen from the partially permeable layer.

The object of the invention is to improve a security element of the type according to the invention in such a way that the protection against forgery is further increased.

This object is achieved by the features of the independent claims. Improvements of the invention are the subject of the dependent claims.

According to the invention, in a first region of the security element, at least one reflective layer is designed to be transparent to light, for example, in the form of a grid or partially reflective, wherein a translucent, preferably opaque, coating is applied to the reflective layer at least in the first region, which coating is designed in the form of information. The security element here shows a different appearance in top view than in perspective view, as seen from the partially permeable layer.

Particularly preferably, the multilayer structure capable of interference is a thin-layer colourshift system, which consists of a three-layer structure consisting of an absorber, a dielectric and a reflector. The reflector is made of, for example, Al, Cu, gold, metallic or a varnish, the dielectric is made of, for example, SiOx, MgF, nitrocellulose or a polymer, and the absorber is made of, for example, Cr.

A translucent, preferably opaque coating is formed, for example, from an opaque or metallic paint, for example containing gold, silver, copper or OVI pigments, wherein a plurality of paints can also be used, which produce multicolored, toned, multicolored grayscale images or true-color images.

According to a further preferred embodiment, the grid is formed by a dot, line or mark grid, a nano-or micro-word with hidden information.

According to a further preferred embodiment, the translucent, preferably opaque coating has a combination with other functions, for example a fluorescent substance or a machine-readable substance, for example an IR (infrared), UV (ultraviolet) or magnetically readable feature substance.

According to a further preferred embodiment, the security element according to the invention is combined with other effects, in particular with holograms, micro-optically variable systems, such as micromirrors, micro-lenses or micro-fresnel lenses.

According to a further preferred embodiment, the information or the subject of the rear image and the reflector grid image are supplemented by one another as a total image or by other subjects produced by an imaging method, for example printing or laser irradiation.

According to a further preferred embodiment, the security element according to the invention is applied to a banknote, wherein the information or the theme of the translucent, preferably opaque, coating and/or the overall see-through information on the banknote is additionally present, for example, in a watermark and/or a printed theme and/or a film theme.

According to a further preferred embodiment, it is also possible to introduce or apply individualized or special markings, for example a part of the numbering or the entire numbering, in the security element according to the invention, for example by means of laser ablation only on one side or on both sides, or else entirely as a see-through element.

The interference-capable multilayer structure can be applied either by vapor deposition or by means of a printing method.

The interference-capable multilayer structure can have a metallic, in particular golden, gloss. The gold paints or corresponding gold pigments can also be magnetic, as is known, for example, from EP 2445972 a 1. Magnetic pigments known from EP 2417207B 1 may also be used. This means magnetic paints which are opaquely enveloped in color, so that yellow, blue, red pigments result.

According to a further preferred embodiment, gold pigments with a magnetic core are used, which are magnetically detectable and IR-transparent. In this case, for example, the golden portrait can be magnetic, and if necessary, a machine-readable magnetic coding or a marking on another part can also be present, which is invisible or partially or completely visible.

Light transmission or light transmission in the sense of the present invention means that an object, for example a substrate or a plastic film, is able to transmit incident light in a certain proportion. If the light reaches one side of the object, a certain fraction of the light is transmitted until it reaches the other side of the object and exits there again. The greater the fraction of the percentage of light transmitted relative to the incident light, the more transparent the object is. An object is referred to as transparent if the percentage share is at least 90%, i.e. the object can transmit incident light with little attenuation as in a window. Conversely, an object is said to be opaque or opaque if it transmits less than 10%, and preferably approximately 0%, of the incident light, i.e. the fraction of transmitted light in the object relative to the incident light is small or equal to 0.

When the substrate is illuminated from one side and viewed from the other side, there is a perspective view. There is a top view when illuminated and viewed from the same side of the substrate.

Particularly preferably, the substrate to which the security element according to the invention can be applied consists of paper or at least one plastic film, for example a polymer (such as PET, BOPP, PP or PA), the paper consists of cotton fibers (as is used, for example, for banknotes), or other natural or synthetic fibers or mixtures of natural and synthetic fibers. Furthermore, the substrate is preferably composed of a combination of at least two different substrates that are stacked and connected to one another, a so-called mixture. The substrate is formed, for example, from a plastic film/paper/plastic film combination (i.e., a substrate formed from paper is covered on each of its two sides with a plastic film) or from a paper/plastic film/paper combination (i.e., a substrate formed from plastic film is covered on each of its two sides with paper).

Data relating to the weight of the substrates used are described, for example, in patent document DE 10243653 a9, the embodiments of which are fully incorporated into the present application in connection therewith. DE 10243653A 9 shows in particular that the paper layer usually has a thickness of 50g/m²To 100g/m²Preferably 80g/m²To 90g/m²The weight of (c). Obviously, any other suitable weight may be used depending on the application.

Documents of value (in which such substrates or security papers can be used) are in particular banknotes, stocks, bonds, certificates, receipts, checks, high-value tickets, but also other papers which are at risk of forgery, such as passports and other identification documents, and cards, such as credit or debit cards (the card body of which has at least one layer of security paper), and also product security elements, such as labels, seals, packaging, etc.

The simplified name "value document" includes all of the above-described materials, documents, and product security media.

The terms "front side" or "back side" of the substrate or the document of value are relative terms, which may also be referred to as "one" and "opposite" side and form a large part of the total surface of the substrate or the document of value. These terms expressly do not include the side of the substrate or the document of value, which is very small and is usually not equipped or provided with security elements or coatings, in the thickness of the substrate or the document of value of only approximately one millimeter for the card body or less than one millimeter for the bank notes. The perspective effect cannot be achieved in particular with the side faces.

The information in the sense of the present invention is a pattern-shaped and visually perceptible coating. The coating may, for example, form a picture, image, number, letter, text or other symbol. Particularly preferably, the information is composed of positive and/or negative subjects. In the case of positive subjects, the subject element itself is applied to the substrate, whereas in the case of negative subjects, the region surrounding the subject element is applied to the substrate. Positive themes are for example letters that are embossed dark onto a light substrate. The negative theme is, for example, a face applied to the substrate in a dark color, which has unprinted areas in the form of letters in the face.

It goes without saying that the features mentioned above and those yet to be explained below can be used not only in the combination described but also in other combinations without departing from the scope of the invention, as long as this is included in the scope of the claims.

The advantages of the invention are illustrated by the following examples and supplementary figures. The examples are preferred embodiments, however, the invention should not be limited to these embodiments. Moreover, the illustrations in the drawings are strongly schematic for better understanding and do not reflect reality. In particular, the proportions shown in the figures do not correspond to the proportions which exist in reality, and are used only for improving the clarity. Furthermore, the embodiments described in the following exemplary embodiments reduce the core information that is important for better understanding. In actual implementation, a significantly more complex pattern or image may be used.

Schematically:

fig. 1 shows an interference-capable multilayer structure in the form of a thin-layer color-shifting system known from the prior art on a carrier substrate;

fig. 2 shows a first embodiment of the invention;

fig. 3 shows a second embodiment of the invention;

fig. 4 shows a third embodiment of the invention;

fig. 5 shows a fourth embodiment of the invention;

FIG. 6 shows a fifth embodiment of the invention;

fig. 7 shows a sixth embodiment of the invention;

fig. 8 shows an example for the first to fourth embodiment forms;

fig. 9 shows an example for a fifth to sixth embodiment;

fig. 10 shows an embodiment of a different grid for the back side impression.

Fig. 1 shows an interference-capable multilayer structure in the form of a thin-layer color-shifting system 100, which is known from the prior art, on a carrier substrate 4, consisting of a metallic reflector layer 3 with openings 6, a spacer layer or dielectric 2 and an absorber layer 1 with openings 5. In a plan view of the front side 10, an angle-dependent color-shifting impression is produced in the regions without

openings

5 and 6, for example in the region 101. Whereas in the regions with openings 5 in the absorber layer 1, for example in the region 104, no angle-dependent color-shifting impression is produced, but rather silver-gray regions independent of the viewing angle. In a plan view seen from the back surface 11, a color impression of silver gray is generated everywhere. In the perspective from the front 10 or from the rear 11, negative information is produced by the region 6 without reflector metal 3.

In the top view, the appearance of the color shift as a function of angle is not visible in the region 102, but rather a colorless appearance, and a roughly gray region is visible in the perspective view, which has a slightly reduced transparency compared to the transparent, metal-free region 106.

In the region 103, as in the region 104, too, an angle-dependent color shift cannot be seen, wherein the region 103 appearing silver gray is adjacent to the region appearing gray here too, unlike the region 104 surrounded by the region having an angle-dependent color shift. Without the reflector and absorber, the region 106 appears colorless in top view and transparent in perspective.

Fig. 2 shows a first embodiment of the invention. In this case, the thin-film color-shifting system 100 is applied to a carrier substrate 4. On the rear side of the carrier substrate 4, a see-through message consisting of a translucent, preferably opaque, coating 7 is applied in regions, which has openings 8.

In this embodiment, the reflector layer 3 is designed as a full-surface, thin, translucent metal vapor deposition, so that the complete information on the rear side can be seen from the rear side. The information formed by the regions 7 can be seen on both sides in the perspective view on the basis of the openings 8. The layer 1 with the openings 5 produces no or negligible information in the perspective view and therefore does not interfere with the information visible in the perspective view of the regions 7 with the openings 8.

Fig. 3 shows a second embodiment of the invention. In this case, in contrast to the first embodiment of fig. 2, the complete perspective information is not arranged on the other side 11 of the carrier substrate 4 relative to the thin-film color-shifting system 100, but on the same film side 10 as the thin-film color-shifting system 100. The layer is therefore internal and particularly preferably protected against handling and wear.

Fig. 4 shows a third embodiment of the invention. In contrast to the first embodiment of fig. 2, the translucent reflector layer 3 is formed by a full-area grid structure of the reflector layer 3, which is formed by small openings 9.

Fig. 5 shows a fourth embodiment of the invention. In this case, in contrast to the third embodiment of fig. 4, the complete perspective information is not arranged on the other side 11 of the carrier substrate relative to the thin-film color-shifting system 100, but on the same film side 10 as the thin-film color-shifting system 100. The layer is therefore internal and particularly preferably protected against handling and wear.

Fig. 6 shows a fifth embodiment of the invention. In contrast to the previous embodiments, the perspective information is generated by the combination of the regions or corresponding openings 6 of the reflector metal 3 and the opaque rear embossings 7 or corresponding openings 8. The two pieces of

information

3 and 7 together produce an image. In this embodiment, however, the two information items are located on different sides of the carrier substrate 4, i.e. the partially demetallized reflector layer 3 is located on the side 10 of the layer system and the imprinted opaque layer 7 is located on the opposite side 11.

Fig. 7 shows a sixth embodiment of the invention. In contrast to the fifth embodiment, the two pieces of information are located on the same side 10 of the carrier substrate 4, i.e. the partially demetallized reflector layer 3 and the imprinted opaque layer 7 are arranged on the same side.

Fig. 8 shows an example for the first to fourth embodiment forms, in which the entire perspective information C is generated by the rear embossing B with the openings 8. The reflector face 3 of the thin-layer color-shifting system is translucent or provided with a micro-grid. The portrait may have a different visible color than the surrounding pattern, e.g., a honeycomb pattern.

Fig. 9 shows an example for a fifth to sixth embodiment, in which the perspective information C is generated by a rear embossing B with openings 8 in combination with the partially demetallized reflector surface 3. The portrait 7 may here have a different visible color than the surrounding pattern, for example a honeycomb pattern.

In the middle area, the partial image a has a microgrids in the reflector area 3 and another visible pattern, a staggered honeycomb pattern in the same reflector layer 3, in the surrounding area. The fine microgrids in the middle area of a do not interfere with the information B in the generated perspective information C, wherein the honeycomb pattern in a can also be seen in C.

Fig. 10 shows an embodiment of a different grid for the back side impression. The rear embossing B or 7 and the demetallized reflector metal a or 3 can have any desired grating in terms of shape and density, so that a coarse or fine resolution can be achieved. A certain three-dimensional or spatial 3D effect/plasticity or stereoscopic impression and/or polychrome can also be achieved by means of a grid or shadow line.

The grid elements can have any arbitrary shape, including alphanumeric characters or symbols, preferably circles, ellipses, squares, diamonds or lines. The resolution is in the range from 10 μm to 1000 μm, preferably between 25 μm and 500 μm.

Claims

1. A security element consisting of an interference-capable multilayer structure consisting of at least one reflective layer, at least one partially permeable layer and at least one dielectric layer arranged between the reflective layer and the partially permeable layer,

in a first region of the security element, the at least one reflective layer is designed to be light-transmissive,

applying an opaque coating on the reflective layer at least in the first region, the coating being structured in the form of information,

the security element, viewed from the partially permeable layer, exhibits a different appearance in top view than in perspective view,

the at least one reflective layer is designed to be transparent to light, in that the reflective layer is designed in the form of a grating or is designed to be partially reflective.

2. A security element according to claim 1, characterized in that the opaque coating consists of a metallic paint.