EP3986719A1 - Security substrate and value document produced therefrom - Google Patents

Abstract

The invention relates to a security substrate for value documents, such as a banknote (1), cheque, credit card or other payment card, ID card or the like, which has a front and a reverse side, in a plan view covers a particular area, and further has: a first carrier film (10), which extends over at least 50 % of the particular area; a substantially opaque layer (17) which is arranged over the first carrier layer (10) and covers at least 25 %, preferably more than 50 % and particularly preferably more than 75 % of the particular area; a first print receiving layer (18) arranged over the opaque layer (17) and having at least one first colour printing element (29) applied thereto; and at least one relief structure (14, 15), which is arranged between the first opaque layer (17) and the first carrier film (10) and is provided with a reflection-enhancing coating (15) which, together with the relief structure (11) or alone, causes an optically variable effect. Alternatively, the first substantially opaque layer can also be omitted and the first print receiving layer can have an opacity.

Description

Security sub at and value document produced from it

The invention relates to a security substrate for documents of value, such as bank notes, checks, credit or other payment cards, identity cards or the like, which has a front and a back and covers a certain area in plan view and is film-based and has at least one relief structure.

There are currently banknotes with different substrates. Paper, polymer and mixed forms of paper and polymer in the form of so-called hybrid banknotes are known. For each type of banknote, special process steps are required in order to apply security elements to the banknote paper or to generate them when the banknotes are printed on the banknote paper.

For documents of value, such as banknotes, film-based security features, e.g. B. holograms, optically variable elements and / or transparent windows can be used. They are produced on foil and later applied to banknote paper in order to obtain a security substrate that can be printed on. In the prior art, safety features are known for this purpose, which usually have at least one have relief structure generated by embossing, for example holograms, nanostructures, micromirrors, moiré magnifiers, etc.

The security features are film-based, and the substrate, which comprises at least one film, is applied to a security substrate as a transfer element. This has the disadvantage that such security features can only be distributed or arranged with restrictions on the security substrate and the value document subsequently produced therefrom. Stripes and security threads can, for example, only be attached with their security elements in a defined, rectangular area. The application of individual patches is associated with high production costs. As the number of security features increases, so does the manufacturing cost for the security substrate or the value document.

In addition, in the case of a security substrate with glued-on security elements, for example in the form of patches, there is a fundamental risk that they will later either detach themselves from the value document in circulation or be detached with fraudulent intent in order to use them to upgrade forged certificates. Foil elements give banknotes an additional protection against forgery, but are also difficult in terms of registration with the print image and the watermark.

A document of value is known from WO 2016/096095 A1 which is composed entirely of a film body. The film body consists of two foils that are connected to one another via an intermediate layer. On the sides facing the intermediate layer, the foils each have sub-wavelength structures. All optical views that are normally generated by printing processes and presented by the value document are now generated by these subwavelength structures. Other image-generating elements such as printing elements are deliberately excluded.

The problems and requirements mentioned exist not only with regard to bank notes, that is to say paper-based or film-based documents of value, but also with payment cards or identification cards. The term "security substrate" is therefore understood here to mean that it includes sheet-like security substrates, such as preliminary stages for printing banknotes, checks, etc. as well as comparatively rigid security unit substrates, e.g. B. preliminary stages for security, ID or payment cards.

The invention is based on the object of creating a security substrate and a value document in which film-based security elements can easily be combined with security elements that are generated by displaying images, etc., with the greatest possible freedom of design, without the manufacturability becoming more difficult. At the same time, a particularly good color of the appearance should be achieved.

The invention is defined in independent claims 1 and 15. The dependent claims relate to advantageous developments of the invention.

The security substrate has a front and a back. It covers a certain area in plan view. It has a first carrier film which extends over at least 50%, preferably over 75% or 100% of this area. A first, essentially opaque layer is arranged over the first carrier film, which layer covers at least 25%, preferably more than 50% and particularly preferably more than 75% of the specific area. A first print acceptance layer is arranged over this first opaque layer, on which a first, colored printing element is preferably formed. A first relief structure is arranged between the first opaque layer and the first carrier film. It is provided with a first reflection-increasing coating which, together with the first relief structure or alone, causes a first optically variable effect.

As an alternative to this, the first essentially opaque layer can also be omitted and the first pressure-receiving layer can have an opacity. In this case, a first print acceptance layer is arranged over the first carrier film, which is essentially opaque and covers at least 25%, preferably more than 50% and particularly preferably more than 75% of the specific area and on which a first, colored printing element is preferably applied forms is. A first relief structure is arranged between the first pressure acceptance layer and the first carrier film. It is provided with a first reflection-increasing coating which, together with the first relief structure or alone, produces a first optically variable effect.

The term “opaque” is understood to mean an opacity of at least 50%, preferably 75% or more.

In one development, the first opaque layer or first pressure acceptance layer is arranged on a second carrier film, which lies between the first opaque layer or first pressure acceptance layer and the first relief structure. This facilitates producibility, since the first opaque layer or first pressure acceptance layer is placed on the second carrier film and then connected to the first carrier film on which the first relief structure is formed, for example by a lamination. This then of course takes place in such a way that the first relief structure lies between the first opaque layer or first pressure acceptance layer and the first carrier film on which the first relief structure is located. As a result, the second carrier film lies between the first opaque layer or first pressure-acceptance layer and the first relief structure.

A second essentially opaque layer can be provided on the side of the first relief structure opposite the first opaque layer or the first pressure acceptance layer. There is also one on this side second print acceptance layer is provided on which a second, colored printing element is formed.

There are several possible ways of doing this. The security substrate can be made from a single film with the first relief structure embossed and embedded in protective varnish. It is equally possible to laminate the first and second carrier films to one another. A three-film structure, of which the middle one is then the first carrier film with the first relief structure, is equally possible.

The relief structure can be embossed on one side of the carrier film. In the same way, it is possible to emboss on both sides, i.e. on the other side of the first carrier film, a second relief structure with a second reflection-increasing coating, so that a coated relief structure is located on both sides of the carrier film in a correspondingly applied embossing lacquer.

The security substrate can be made purely film-based. However, a combination with paper is also possible. A paper layer can be used as the core, on the surfaces of which the foils are applied over the entire area, one of the foils then being the first carrier foil. Of course, foils applied to the paper core on both sides can also have relief structures. Then the already mentioned second relief structure is provided. An inversion of this structure is possible to the effect that paper layers are applied as the core to the carrier film, which carries the first (and possibly also the second) relief structure. This can be done by lamination. With regard to the reflection-increasing coating, metallizations such as aluminum, gold, silver, chromium, Cr-Al, Cr-Al-Cr or alloys come conditions, e.g. B. Cu-Al, in question. So-called color-shift or color-change coatings are equally possible, i.e. layer sequences made of metal-dielectric-metal. Another possibility is semitransparent metallizations, in order to only partially cover the colored printing elements, or metallic pigment colors or flakes. The relief structure usually produced by embossing can then be metallized using printing technology.

The reflection-increasing coating can be structured laterally. This is usually referred to as demetallization and is done to reveal the effect or print elements behind. A multitude of means are known to those skilled in the art for demetallization, for example so-called wash color printing, etching techniques, metal transfer processes, printing with an oil film before vapor deposition, etc. The lateral structuring of the opacity of the reflection-increasing coating can create the appearance of a watermark.

A wide variety of metal pigment colors or flakes, translucent colors, fluorine colors, structural or binary colors in the form of nanostructures, etc. can be used for the colored printing element. The print acceptance layer can be an opaque white or a semi-transparent or fully transparent color acceptance layer.

If, as already mentioned above, a combination with paper layers is made, a low grammage can particularly preferably be chosen in order to locally vary the transparency of the paper portion. In this way, embossed optical effects can be made visible through the paper - in turn, a watermark is obtained. Appearance. As already mentioned above, cutouts are also possible in the paper. This can be done by a laser cut, etc. Another option is the use of colored mottled fibers.

The relief structure can realize the optically variable effect using a wide variety of known techniques. Examples are hologram structures, nanostructures, micromirrors, blazed gratings, sawtooth structures, microstructures, microfocusing elements such as lenses, Fresnel lenses, concave mirrors, Fresnel concave mirrors, pinhole and slit diaphragms, each in combination with microstructures to create modulo mappers - or Moiré magnifier structures. Microfocusing menhang are particularly interesting in together with two- or multi-layer films, since then the thick ren composite structures larger focal lengths and optical effects and allow printing elements can act ogether with the microfocusing _Z better.

According to a preferred embodiment, the micromirrors can be arranged in the z-direction at different height levels, as is special from DE 102018005474 A1, DE 102018005447 A1 or DE

102018005454 Al is known.

If foils are laminated with one another or foils with paper or paper are laminated with one another, conventional laminating adhesives can be used. Colored and / or semi-transparent laminating adhesives are also possible, as are laminating adhesives that create fluorescent effects, OVI, metal flakes, etc. A lamination without adhesive is equally possible, for example by melting under pressure or temperature. The security elements that are formed on the security substrate using the options mentioned above can be distributed as desired over the entire security substrate. This also makes it possible to design particularly individual security features, since the arbitrary distributability of the security elements now achieved was not possible in the prior art.

When laminating film layers, the printed image, that is to say the colored printing elements and / or the print acceptance layer, can be aligned inwards, which is of course useful in the case of multi-layer structures. A bare film surface can then be obtained as the outside of the security substrate, so that the security features are particularly well protected. This leads to high circulation stability.

Furthermore, completely transparent or partially transparent windows can also be realized, for example over demetallized areas, in the relief structure and / or the reflection-increasing coating and / or the opaque layer. These windows can also be provided with semitransparent color shift coatings etc. In addition, it is possible to apply different vapor coatings in an overlapping manner in order to generate different optical impressions from the front and the rear, for example different basic colors.

The machine readability of the security substrate can be improved by applying or introducing conductive materials.

The security substrate can be produced both as before in the known sheet-fed banknote printing, as well as in roll-to-roll printing. At last- In the process, the colored printing element is printed onto the finished product that has already been laminated or onto the foils to be laminated together.

In particular, provision is made for a window to be formed in the first opaque layer or first pressure acceptance layer and / or the second opaque layer - if the latter is present - so that the security substrate in the area of the window is at least partially transparent or the relief structure with the reflection-increasing coating is visible through the window in the opaque layer or the first pressure acceptance layer. If you apply windows lying one above the other in two opaque layers or a pressure acceptance layer and an opaque layer, you get a transparency security feature. The first opaque layer or first pressure acceptance layer and - if present - the second opaque layer can each be designed as a white layer, in particular as an opaque white layer.

Various embossing processes can be used to manufacture the relief structure. In particular, an embossed layer is provided on the carrier film for this purpose. The relief structure can also be designed in sections as a sub-wavelength structure and there have a periodicity of 150 nm to 500 nm or be designed aperiodically with a structure width of 150 nm to 500 nm.

A laterally structured opacity is preferred for the opaque layer or print acceptance layer and / or the reflection-increasing coating, so that a light / dark representation is visible when viewed through transmitted light. Of course, this applies to each of the opaque layers and reflection-increasing coatings that may be provided. In addition, it is possible to arrange a further layer with laterally structured opacity between the first opaque layer or first pressure acceptance layer and the second opaque layer. This can be the reflection-increasing coating itself, which has gaps or cutouts.

In addition, each opaque layer can also be designed as a further print acceptance layer, so that additional print images are possible, also on the inside of the security substrate.

A translucent colored color can be printed over or under the reflection-increasing coating, so that the optically variable effect is influenced with regard to its color impression.

A tactile embossing can be formed on the outside of the security substrate, preferably in the form of a steel engraving.

Each of the colored printing elements provided can be applied at least in regions over the relief structure and the reflection-increasing coating in such a way that the ophsch variable effect appears in a color influenced by the colored printing element.

In the context of the invention, of course, a document of value is also provided that has been produced from a security substrate of the type described and is individualized by printing on one of the intended print acceptance layers, in particular by a printed serial number, etc.

In the context of this description, metallization is to be understood as a coating which consists of metal or which contains metal. A layer structure is also possible, which consists of a composite layer, the metal has storage. But it can also consist of a multilayer structure in which one or more layers are metallic.

For the production of the security substrate, embossing processes, in particular direct exposure techniques, e.g. B. with the help of a laser writer in question. The original of the embossed structure is written into a substrate coated with photoresist by direct exposure with the aid of a laser writer, and the exposed portion of the photoresist is then removed. More complex processes for original production such as electron beam or “focused ion bean” exposure processes allow the embossed structure to be designed particularly finely. The original exposed in this way can then be electroformed and thus an embossing stamp can be generated as a master, with which an embossing cylinder for embossing a film web is produced. Ultimately, the structure is replicated via an embossing process, for example in UV varnish on film or directly (e.g. by hot embossing in the surface of the film). Alternatively, a nanoimprint process can be used. The embossed film surface is then metallized, e.g. B. with a reflective layer and / or a color effect cause the structure, z. B. an interference layer structure, and / or a color layer, z. B. a Color-Fix coating. Electron beam vapor deposition, sputtering or thermal evaporation in a vacuum, among others, are possible for this purpose. Finally, the film is laminated together with the intermediate layer.

It goes without saying that the features mentioned above and those yet to be explained below can be used not only in the specified combinations, but also in other combinations or alone, without departing from the scope of the present invention. The invention is explained in more detail below by way of example with reference to the accompanying drawings, which also disclose features essential to the invention. Show it:

1 shows a plan view of a bank note,

2 and 3 are sectional views for different embodiments for the security substrate from which the bank note of FIG. 1 is Herge, and

4 and 5 are front and back views of a further bank note.

1 schematically shows a bank note 1 which is structured over the entire surface with an embossed structure and is constructed from a substrate body 2 which realizes a security substrate and has a height H and a width B. The substrate body 2 thus covers a certain area in plan view, which is shown in FIG. 1. In a first embodiment, which shows the sectional view of FIG. 2, it is constructed from a film that covers the same area. These and further variants for the construction of the substrate body are explained below with reference to the further figures.

In Fig. 1 it can be seen that the bank note 1, which is an example of a document of value, a viewer from the front, which is shown in Fig. 1, provides a representation 3, as is usual for bank notes. The representation 3 can include, for example, a graphically designed background 4, a moiré image 5, a hologram 6, a value 7 and a serial number 8. It is also possible to provide a window 9 in which the banknote is partially transparent. In the window 9, for example, see-through effects can be present, ie a motif visible on the front is complemented a motif visible on the back in a look through to another motif.

The substrate body 2 with the height H and the width B is constructed from at least one first carrier film of the same or smaller dimensions. In the embodiments, the carrier film covers at least 50% of the specific area, preferably the entire area.

The sectional views of Figures 2 and 3 differ with regard to the embodiment of the substrate body 2. They have in common that a relief structure is provided. In the embodiment of FIG. 3, the substrate body 2 comprises a plurality of carrier films, in the embodiment of FIG. 2, a carrier film.

The substrate body 2 has a first (and in the embodiment of FIG. 2 also the single) carrier film 10, on which a first relief structure 11 is formed in a suitable embossing lacquer layer (not shown further). This can be embodied as a microstructure 12, for example as a diffractive hologram structure, as a subwavelength structure 13 and / or as a micromirror structure 14. As FIG. 2 shows, different types of structures can be used in the relief structure 11. The structures are provided with a reflection-increasing coating 15 on their upper side. Above the reflection-increasing coating 15, an opaque layer 17 is arranged by means of an, for example, designed as a lamination 16, leveling intermediate layer, on which a pressure acceptance layer 18 is out. A colored printing element 19 is printed on this.

Fig. 3 shows an embodiment with substrate body 2 from several Trä gerfolien. Here the opaque layer 17 is on a second carrier photo lie 20, which lies between the first relief structure 11 and the opaque layer 17. The lamination 16 is provided here not only over the first relief structure 11, but also on the underside of the first carrier film 10, since a third carrier film 21 is optionally provided here on the underside of the first carrier film 10, which is on its underside, i.e. that of the first Re flow structure 11 facing away from the side, a second opaque layer 22 and a second print acceptance layer 23 for a (not shown in Fig. 3) second colored printing element. The use of additional carrier foils makes production easier, since the first relief structure 11, the first and second opaque layers 17, 22 and pressure acceptance layer 18, 23 are each produced on their own carrier foils and then through the lamination in the direction of the arrows symbolically shown in FIG. 3 16 can be joined together.

A second, reflection-increasing coated relief structure is optionally formed on the underside of the first carrier film 10 or on the upper side of the third carrier film 21. What was said about the first relief structure applies to them accordingly.

3 shows a further optional feature, namely that windows 24 can be provided in the first and second opaque layers 17, 22 as well as pressure acceptance layers 18, 23, the mode of operation of which has already been explained in the general part of the description. You can, differently al in Fig. 3 shows ge, also be formed in an identical lateral position. The print acceptance layer can also be combined with the opaque layer in the embodiments.

4 and 5 show exemplary designs for a substrate body 2, once from the front (FIG. 4) and once from the rear (FIG. 5). Here, reference number 25 denotes a security feature with micromirrors in FIG a window design, reference numeral 26 superficial micro-mirror effects, reference numeral 27 relief structures generating hologram effects, and reference numeral 28 translucent colors on a micro-mirror structure as a relief structure. Next, the first print acceptance layer 18 is provided on the front side, on which a first colored printing element 29, here essentially covering the entire front side, is formed.

FIG. 5 shows the view from the rear, corresponding to the lower side in FIG. 3. In addition to the elements shown in FIG. 3, there is a further, second relief structure with a reflection-increasing coating on the rear of the first carrier film 10, so that also on the Backside the micro mirror structures are present. The transparent window 30, which is already recognizable in the front, can of course also be seen on the rear. The second relief structure, which is formed on the rear side of the carrier film 10, further comprises holograms 31, and a colored printing element 32 is also applied to the lower pressure-receiving layer 23. Reference symbol 33 denotes translucent colors on a micromirror structure as a relief structure. Although it goes without saying, due to the optical requirements, it should be pointed out that the carrier films are of course transparent. The same applies to the embossing lacquer coating in which the relief structures are formed. List of reference symbols

Banknote 23 second print acceptance layer

Substrate body 24 windows

Figure 25 Mirroring security feature with micro

Background 26 micromirror effects

Moire image 27 producing hologram effects

Relief structures

Hologram 28 translucent colors

Value information 29 first colored printing element

Serial number 30 clear window

Window 31 holograms

first carrier film 32 second colored printing element first relief structure 33 translucent colors

Microstructure

Sub-wavelength structure

Micromirror structure

reflection-increasing Be

layering

Lamination

first opaque layer

Pressure acceptance layer

colored print element

second carrier film

third carrier film

second opaque layer

Claims

Patent claims 1.Security substrate for documents of value, such as a bank note (1), a check, a credit or other payment card, an identity card or the like, which has a front and a back, covers a certain area in plan view and has: a first carrier film (10) that extends over at least 50% of the specified area, - A substantially opaque layer (17) arranged over the first carrier film (10), which covers at least 25%, preferably more than 50% and particularly preferably more than 75% of the specific area, a first, over the opaque layer (17) arranged pressure acceptance layer (18) and - At least one relief structure (14, 15) which is arranged between the first opa ken layer (17) and the first carrier film (10) and is provided with a reflection-increasing coating (15) which, together with the relief structure (11) or alone, is a causes optically variable effect. 2. Security substrate for documents of value, such as a bank note (1), a Check, a credit or other payment card, an identification card or the like, which has a front and a back, covers a certain area in plan view and has: a first carrier film (10) that extends over at least 50% of the specified area, a first, over the first carrier film (10) arranged first print acceptance layer (18), which is substantially opaque and at least 25%, preferably more than 50% and particularly preferably more than 75% of the particular area covered, and - At least one relief structure (14, 15) between the first Print acceptance layer (18) and the first carrier film (10) and arranged is provided with a reflection-increasing coating (15), which together with the relief structure (11) or alone causes an optically variable effect. 3 Security substrate according to claim 1 or 2, wherein at least one first colored printing element (29) is applied to the first pressure-receiving layer (18). 4. Security substrate according to one of claims 1 to 3, wherein the first opaque layer (17) or first pressure acceptance layer (18) is arranged on a second carrier film (20) which is sandwiched between the first opaque layer (17) and first pressure acceptance layer ( 18) and the relief structure (11) lies. 5. Security substrate according to one of claims 1 to 4, wherein a second substantially opaque layer (22) is arranged on and on a side of the relief structure (11) opposite the first opaque layer (17) or the first pressure acceptance layer (18) Page also has a second print acceptance layer (23) and a second color printing element (32) applied thereon. 6. Security substrate according to one of claims 1 to 5, wherein a window (24) in the first opaque layer (17) or first pressure acceptance layer (18) and / or the second opaque layer (22) - if the latter is present - is formed so that the security substrate becomes transparent in the area of the window (24) or the relief structure (11) with the reflective coating (15) through the window (24) in the opaque layer (17, 22) or first pressure acceptance layer (18 ) is visible. 7. Security substrate according to one of claims 1 to 6, each in connection with claim 2, wherein the window (24) in the first and in the second opaque layer (17, 22) and first pressure acceptance layer (18) at least partially in plan view overlap. 8. Security substrate according to one of claims 1 to 7, wherein the first opaque layer (17) or first pressure acceptance layer (18) and / or the second opaque layer (22) - if the latter is present - is a white layer. 9. Security substrate according to one of claims 1 to 8, characterized in that the relief structure (11) is formed in sections as a subwellenlän gene structure (13) and there has a periodicity of 150 nm to 500 nm or there aperiodically with a feature size of 150 nm to 500 nm is formed. 10. Security substrate according to one of claims 1 to 9, wherein the first opaque layer (17) or first pressure acceptance layer (18) and / or the second opaque layer (22) - if the latter is present - has a laterally structured opacity, so that a light / dark representation is visible when viewed through transmitted light. 11. Security substrate according to one of claims 1 to 10, each in connection with claim 2, wherein between the first opaque layer (17) or first pressure acceptance layer (18) and the second opaque layer (22) is a further layer with laterally structured opacity is arranged so that a light / dark representation is visible when viewed through transmitted light. 12. The security substrate according to claim 11, wherein the further layer is formed by the reflection-increasing coating (15) with gaps or recesses are provided for laterally structured opacity variation. 13. Security substrate according to one of claims 1 to 12, wherein the first opaque layer (17) or first pressure acceptance layer (18) and / or the second opaque layer (22) - if the latter is present - as a further Druckan acceptance layer (23) is trained. 14. Security substrate according to one of claims 1 to 13, wherein above or below the reflection-increasing coating (15) a translucent colored color (28) is printed, which influences a color impression of the optically variable effect. 15. Security substrate according to one of claims 1 to 14, wherein a tactile embossing is formed on egg ner outside, preferably in the form of a steel engraving print. 16. Security substrate according to one of claims 1 to 15, wherein the first colored printing element (29) and / or the second colored printing element (32) - if the latter is present - at least partially above the relief structure (11) and the reflection-increasing coating ( 15) is attached so that the optically variable effect appears in a color influenced by the printing element (19). 17. Document of value with a security substrate according to one of claims 1 to 16, the document of value being individualized by printing on the first print acceptance layer (18) and / or the second print acceptance layer (23) - if the latter is present - is individualized, in particular a printed one Serial number (8).