CN113966279B

CN113966279B - Security substrate and value document produced therefrom

Info

Publication number: CN113966279B
Application number: CN202080042839.5A
Authority: CN
Inventors: M.海姆; T.萨特勒; U.肖姆伯格; C.富斯; M.R.J.谢勒; R.德梅尔
Original assignee: Giesecke and Devrient GmbH
Current assignee: Giesecke and Devrient GmbH
Priority date: 2019-06-18
Filing date: 2020-06-15
Publication date: 2023-04-04
Anticipated expiration: 2040-06-15
Also published as: EP4112326B1; CN113966279A; EP4112324B1; WO2020253991A1; EP4112324A1; EP3986719A1; DE102019004325A1; EP4112326A1; EP4112325A1; EP4112325B1

Abstract

The invention relates to a security substrate for value documents, such as banknotes (1), checks, credit cards or other payment cards, identification cards, etc., having a front side and a rear side, covering a defined area in plan view and furthermore having: a first carrier film (10), a first opaque layer (17) arranged above the first carrier film, a first print receptive layer (18) arranged above the opaque layer, the first carrier film extending over at least 50% of the defined area, the first opaque layer covering at least 25% of the defined area, the first print receptive layer having at least one coloured first printing element applied on the first print receptive layer, and at least one relief structure arranged between the first opaque layer and the first carrier film and provided with a reflection enhancing coating acting together or separately with the relief structure to achieve an optically variable effect. Alternatively, the first opaque layer may be eliminated and the first print receptive layer may have opacity.

Description

Security substrate and value document produced therefrom

Technical Field

The invention relates to a security substrate for value documents, such as banknotes, checks, credit cards or other payment cards, or identification cards, etc., having a front side and a rear side and covering a defined area in a top view and being based on a film and having at least one relief structure.

Background

Banknotes with different substrates currently exist. Paper, polymers and mixed forms made of paper and polymers in the form of so-called hybrid banknotes are known. For each banknote type, special process steps are required in order to apply the security element to the banknote paper or to produce the security element when printing banknotes on the banknote paper.

For value documents, such as banknotes, film-based security features, such as holograms, optically variable elements and/or transparent windows, can be used. The security feature is manufactured on a film and then applied on banknote paper in order to obtain a security substrate that can be printed. For this purpose, security features having at least one relief structure, which is usually produced by embossing, such as holograms, nanostructures, micromirrors or moire enlargers, are known from the prior art.

The security feature is based on a film and a substrate comprising at least one film is applied as a transfer element on the security substrate. The disadvantage resulting therefrom is that such security features can only be allocated or arranged to a limited extent on the security substrate and the value document produced therefrom afterwards. The strips and security threads, for example with their security elements, can only be applied in defined, rectangular areas. Applying individually unique patches is associated with higher manufacturing costs. The manufacturing effort for security substrates or value documents increases with the number of security features.

Furthermore, in the case of security substrates having adhesively bonded security elements, for example in the form of patches, there is the risk that the security elements subsequently fall off themselves from the value document in circulation or are detached from the value document with fraudulent intent in order to use them for the upgrading of counterfeits. The film element imparts additional security to the banknote against forgery, but is also difficult to achieve in terms of the precision of the fit to the printed image and the watermark.

From WO 2016/096095 A1, a document of value is known which is constructed entirely from a film body. The membrane body consists of two membranes which are connected to one another by an intermediate layer. On the sides pointing towards the intermediate layer, the films each have a subwavelength structure. All optical views which are usually produced by printing processes and which are presented by the value document are now produced by means of subwavelength structures. Other imaging elements, such as printing elements, are intentionally excluded.

The problems and requirements are not only present in banknotes, i.e. paper or film-based value documents, but also in cards for payment or identification. The term "security substrate" is therefore to be understood here to include both sheet-like security substrates, such as precursors for printing banknotes, checks and the like, and also relatively rigid security substrates, such as precursors for security cards, identification cards or payment cards.

Disclosure of Invention

The object of the present invention is to provide a security substrate and a document of value, in which a film-based security element can be combined simply with the security element produced by the display of an image or the like with the greatest possible degree of freedom of design without increasing the difficulty of production. At the same time, a particularly good color rendering (Farbigkeit) should be achieved.

The technical problem mentioned above is solved according to the following technical solution of the present invention.

The anti-counterfeiting substrate is provided with a front surface and a back surface. The anti-counterfeiting substrate covers a certain area in a top view. The security substrate has a first carrier film which extends over at least 50%, preferably 75% or 100%, of the area. A first substantially opaque layer is arranged over the first carrier film, which opaque layer covers at least 25%, preferably more than 50% and particularly preferably more than 75% of the defined area. A first print receptive layer, on which preferably colored first printing elements are designed, is arranged above the first opaque layer. A first relief structure is arranged between the first opaque layer and the first carrier film. The first relief structure is provided with a reflection-enhancing coating which acts jointly or separately with the first relief structure to achieve a first optically variable effect.

As an alternative to this, it is also possible to eliminate the first substantially opaque layer and the first print receptive layer has opacity.

In this case, a first print receptive layer is arranged above the first carrier film, which is substantially opaque and covers at least 25%, preferably more than 50% and particularly preferably more than 75% of the defined area, and on which a colored first printing element is designed. The first relief structure is arranged between the first print receptive layer and the first carrier film. The first relief structure is provided with a first enhanced reflective coating which acts together with or separately from the first relief structure to achieve an 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 the first print receptive layer is arranged on a second carrier film, which is located between the first opaque layer or the first print receptive layer and the first relief structure. This makes production easier, since the first opaque layer or the first print receptive layer is applied to the second carrier film and is subsequently connected, for example by lamination (kaschiruding), to the first carrier film on which the first relief structure is formed. This is of course done so that the first relief structure is between the first opaque layer or the first print receptive layer and the first carrier film having the first relief structure thereon. The second carrier film is thus between the first opaque layer or the first print receptive layer and the first relief structure.

The second substantially opaque layer may be provided on the opposite side of the first relief structure to the first opaque layer or the first print receptive layer. On this side, a second print receptive layer is thus also provided, on which the colored second printing elements are formed.

In this way, there are several possible implementations. The security substrate can be produced from a single film by embossing the first relief structure and embedding a protective lacquer. It is likewise possible to laminate the first and second carrier films to one another. A three-film structure is also possible, wherein the intermediate film is then a first carrier film with a first relief structure.

The relief structure may be embossed on one side on the carrier film. Double-sided embossing is also possible, i.e. a second relief structure with a second reflection-enhancing coating is provided on the other side of the first carrier film, so that the embossing lacquer applied to the carrier film has a coated relief structure on both sides thereof.

The security substrate can be designed purely on a film basis. But combinations with paper are equally possible. The paper layer can serve as a core, to the surface of which the film is applied over the entire surface, wherein one of the films is thus the first carrier film. Of course, the film applied bilaterally on the core may also have a relief structure. The second relief structure already mentioned is then provided. The inversion of this structure is possible by applying a paper layer as a core on a carrier film carrying the first (and possibly also the second) relief structure. This can be achieved by lamination.

Metallizations such as aluminum, gold, silver, chromium-aluminum-chromium or alloys, for example copper-aluminum, can be considered in connection with the enhancement of the reflective coating. Likewise possible are so-called color-shifting or color-shifting coatings, i.e. layer sequences made of metal, dielectric and metal. Other possibilities are translucent metallizations to only partially cover the colored printing elements, either metallic pigment colors or metallic pigment flakes. The relief structure, which is usually produced by embossing, can thus be metallized by printing techniques.

The enhanced reflection coating may be structured in the lateral direction. This is often referred to as demetallization and is used to enable viewing of the effect element or printing element located therebelow. A number of ways for demetallization are known to the person skilled in the art, such as so-called wash-out pigment printing, etching techniques, metal transfer methods, printing with an oil film before evaporation, etc. The look and feel of the watermark can be created by lateral structuring that enhances the opacity of the reflective coating.

Different metallic pigment colors or metallic pigment flakes, colors of glazing, colors of fluorine, structural colors or binary colors in the form of nanostructures, etc. are conceivable for the colored printing elements. The print receptive layer may be zinc white or a translucent or fully transparent color receptive layer.

If, as already mentioned above, a combination with a paper layer is made, it may be particularly preferred to choose a lower grammage in order to locally change the transparency of the paper portion. In this way the optical effect of the imprint can be seen through the paper, again giving the impression of the watermark. It is also possible to provide a recess in the paper as already mentioned above. This may be achieved by laser cutting or the like. A further alternative is to use colored mixed color fibers.

The relief structure can achieve optically variable effects by different known techniques. Such as hologram structures, nano-structures, micro-mirrors, blazed gratings, sawtooth structures, micro-focusing elements such as lenses, fresnel lenses, concave mirrors, fresnel concave mirrors, aperture plates and slit plates, respectively, which are combined with micro-structures to produce a mode mapper structure or a moire magnifier structure. The micro-focusing elements are particularly attractive when combined with two or more layers of film, since thicker composite structures thus allow for greater focal lengths and better interaction of the optical effect elements and the printing elements with the micro-focusing elements.

According to a preferred embodiment, the micromirrors can be arranged in the z direction in different height levels, as is known in particular from DE 102018005474A1, DE 102018005447A1 or DE 102018005454 A1.

If films are laminated to each other or films are laminated to paper or paper are laminated to each other, a common laminating adhesive may be applied. Also possible are colored and/or translucent laminating adhesives or laminating adhesives that achieve a fluorescent effect, OVI (optically variable inks), foil, etc. Lamination without adhesives, for example by melting under pressure or temperature, is likewise conceivable.

The security element which is designed on the security substrate by the above-mentioned alternatives can be distributed over the entire security substrate at will. Furthermore, this allows particularly individually unique security features to be realized, since any dispensability of the security element which is currently realized cannot be realized in the prior art.

When laminating the film layers, the printed image, i.e. the coloured printing element and/or the print receptive layer, may be oriented inwards, which is necessarily appropriate for a multilayer structure. In this case, a bare film surface is obtained as the outer side of the security substrate, so that the security features are particularly well protected. This achieves a high flow durability.

Furthermore, a completely or partially transparent window can also be realized in the relief structure and/or in the reflection-enhancing coating and/or in the opaque layer, for example by means of demetallized regions. These windows may also be provided with translucent colour shifting coatings or the like. It is also possible to apply different evaporation sections one above the other in order to produce a different optical impression from the front and rear side, for example a different base color.

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

The security substrate can be produced either as in the known printing of large-size banknotes, as has been the case hitherto, or in a roll-to-roll manner. In the roll-to-roll process, a colored printing element is printed on the finished product that has been laminated or on the films that need to be laminated together.

In particular, provision is made for a window to be provided in the first opaque layer or the first print-receiving layer and/or in the second opaque layer, if present, so that the security substrate becomes at least partially transparent in the region of the window or the relief structure with the reflection-enhancing coating can be seen through the window in the opaque layer or the first print-receiving layer. If superimposed windows are applied in two opaque layers or a print receptive layer and one opaque layer, a see-through security feature is obtained. The first opaque layer or the first print receptive layer and, if present, the second opaque layer can each be designed as a white layer, in particular as a zinc white layer.

Different embossing processes can be considered for the production of the relief structure. For this purpose, in particular, an embossing layer is provided on the carrier film. Furthermore, the relief structures can be designed as subwavelength structures in some sections and have a periodicity of 150nm to 500nm there or a structure width of 150nm to 500nm aperiodically.

A laterally structured opacity is preferred for the opaque layer or print receptive layer and/or the enhanced reflective coating so that a light/dark view is visible when viewed in transmitted light. This of course applies to each opaque layer and enhanced reflection coating that may be provided.

It is additionally possible to arrange further layers with a laterally structured opacity between the first opaque layer or the first print receptive layer and the second opaque layer. This may be the enhanced reflection coating itself, with a gap or a void.

Furthermore, each opaque layer can also be designed as a further print-receptive layer, so that additional printed images are possible which are also located within the security substrate.

Above or below the reflection-enhancing coating, a gloss colour can be printed, so that the optically variable effect is influenced with respect to its colour impression.

On the outer side of the security substrate, a perceptible embossing can be provided, which is preferably in the form of a steel plate engraved embossing.

The relief structure and the reflection-enhancing coating can be applied at least in regions to each of the provided colored printing elements in such a way that the optically variable effect appears in a plurality of colors which are influenced by the colored printing elements.

Within the scope of the invention, a document of value is also provided, which is produced from a security substrate of the type mentioned and is individualized by the printing on the provided print-receptive layer, in particular by the printed serial number or the like.

In this specification, metallization (or metallization layer) is understood to be a coating made of or comprising metal. A layer structure consisting of a composite layer with metal inserts is also possible. The metallization may also consist of a multilayer structure in which one or more layers are metallic.

For the production of security substrates, imprint methods are conceivable, in particular direct exposure techniques, for example by means of laser engraving machines. The prototype of the imprinted structure is engraved by direct exposure with the aid of a laser engraving machine into a substrate coated with a photosensitive lacquer and the exposed portions of the photosensitive lacquer are subsequently removed. More elaborate methods for prototyping, such as electron beam or "focused ion beam" exposure methods, allow particularly fine designs of the imprinted structures to be realized. The prototype thus exposed can then be electroformed and thus produce an embossing punch as a master from which an embossing cylinder for embossing the film web is produced. Finally, the structure is replicated on the film by an embossing process, for example in a UV lacquer, or directly (for example by hot pressing into the surface of the film). Alternatively a nano-imprinting method may be used. The imprinted film surface is subsequently metallized, for example by means of a reflective layer and/or a structure that effects a color effect, for example an interference layer structure, and/or a color layer, for example a color-fixing coating. Electron beam evaporation, sputtering or thermal evaporation in vacuum are primarily considered for this purpose. Finally, the film is laminated with an 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 combination indicated, but also in other combinations or alone without leaving the scope of protection of the invention.

Drawings

The invention is explained in more detail below, by way of example, on the basis of the accompanying drawings, which also disclose features that are important for the invention. In the drawings:

figure 1 shows a top view of a banknote,

fig. 2 and 3 show cross-sectional views for different embodiments of a security substrate from which the bank note of fig. 1 is produced, and

figures 4 and 5 show front and rear views of other banknotes.

Detailed Description

Fig. 1 schematically shows a banknote 1 which is surface-structured overall by embossing, and which is composed of a substrate body 2 which forms a security substrate and has a height H and a width B. The substrate body 2 thus covers a defined area in the top view shown in fig. 1. In the first embodiment shown in the cross-sectional view of fig. 2, the substrate body is composed of films covering the same area. This and other variants of the structure of the substrate body are explained below with reference to further figures.

In fig. 1, it can be seen that a banknote 1 as an example of a document of value provides a viewer with a view 3 from the front side shown in fig. 1, as is customary for banknotes. The view 3 may comprise, for example, a graphically designed background 4, a moire pattern 5, a hologram 6, a denomination 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, a perspective effect can be present, i.e., a theme (Motiv, or visual object) that is visible on the front side and a theme (Motiv, visual object) that is visible on the rear side complement one another in the perspective.

The substrate body 2 having a height H and a width B is composed of at least one first carrier film having the same or smaller dimensions. The carrier film covers in this embodiment at least 50% of the defined area, preferably the entire area.

The sectional views of fig. 2 and 3 differ with respect to the embodiment of the substrate body 2. They differ in that they are provided with a relief structure. In the embodiment of fig. 3 the substrate body 2 comprises a plurality of carrier films, in the embodiment of fig. 2 the substrate body 2 comprises one carrier film.

The substrate body 2 has a first (and in the embodiment of fig. 2 also the only) carrier film 10, on which a first relief structure 11 is provided in a suitable (not further shown) embossing lacquer layer. The first relief structure may be designed as a microstructure 12, for example as a diffractive hologram structure, as a subwavelength structure 13 and/or as a micro-mirror structure 14. As shown in fig. 2, different kinds of structures may be used in the relief structure 11. The structures are provided with a reflection-enhancing coating 15 on their upper side. Above the enhanced reflection coating 15, an opaque layer 17 is arranged by means of an equivalent intermediate layer, for example designed as a laminate 16, on which opaque layer 17 a print receptive layer 18 is designed. On which a coloured printing element 19 is printed.

Fig. 3 shows an embodiment with a substrate body 2 composed of a plurality of carrier films. Here, the opaque layer 17 is on a second carrier film 20, which is between the first relief structure 11 and the opaque layer 17. The laminating unit 16 is here arranged not only above the first relief structure 11, but additionally also on the underside of the first carrier film 10, since here optionally a third carrier film 21 is arranged on the underside of the first carrier film 10, which third carrier film has on its underside, i.e. on the side facing away from the first relief structure 11, a second opaque layer 22 and a second print receptive layer 23 for second colored printing elements (not shown in fig. 3). The use of a further carrier film simplifies the production, since the first relief structure 11, the first and second opaque layers 17, 22 and the print

receptive layers

18, 23 are each produced on their own carrier film and are thus joined by the laminating section 16 in the direction of the arrow schematically shown in fig. 3.

A second relief structure coated with reflection-enhancing effect is optionally provided on the underside of the first carrier film 10 or on the upper side of the third carrier film 21. For which the explanations for the first relief structure apply according to the invention.

Fig. 3 shows further optional features which may be provided in the first and second opaque layers 17, 22 and the print

receptive layers

18, 23, the window 24, the manner of their function having been explained in the summary of the description. They can also be designed in the same lateral position, differently from that shown in fig. 3. In such embodiments, the print receptive layer may also be integral with the opaque layer.

Fig. 4 and 5 show exemplary designs for the substrate body 2 from the front side (fig. 4) and from the rear side (fig. 5). Here, reference numeral 25 denotes a security feature with micromirrors in a window design, reference numeral 26 denotes a micromirror effect on the surface, reference numeral 27 denotes a relief structure which produces a hologram effect and reference numeral 28 denotes the color of the light on the micromirror structure as a relief structure. Furthermore, a first print receptive layer 18 is arranged on the front side, on which a first colored printing element 29 is formed, here substantially covering the entire front side.

Fig. 5 shows a view of the rear side, corresponding to the lower side in fig. 3. In addition to the elements shown in fig. 3, a further second relief structure with a reflection-enhancing coating is provided on the rear side of the first carrier film 10, so that a micromirror structure is also present on the rear side. Of course, the transparent window 30, which is already recognizable on the front side, is also visible on the rear side. Furthermore, the second relief structure designed on the rear side of the carrier film 10 comprises a hologram 31, and a colored printing element 32 is also applied on the lower print-receptive layer 23. Reference numeral 33 denotes a color of light shining on the micromirror structure as a relief structure.

Although this is self-evident from the optical requirements, it is also to be noted that the carrier film is of course transparent. The same applies to embossing lacquer coatings designed with a relief structure.

List of reference numerals

1 banknote

2 substrate body

3 view of

4 background

5 Moire pattern

6 hologram

Description of 7 denomination

8 sequence number

9 window

10 first carrier film

11 first relief structure

12 micro-structure

13 sub-wavelength structure

14 micro-mirror structure

15 enhanced reflective coating

16-layer laminate

17 first opaque layer

18 print receptive layer

19 colored printing element

20 second carrier film

21 third carrier film

22 second opaque layer

23 second print receptive layer

24 window

25 anti-counterfeiting element with micro-mirror

26 micro mirror effect

27 relief structure for producing a hologram effect

28 color of light

29 colored first printing element

30 perspective window

31 hologram

32 colored second printing element

33 color of light

Claims

1. A security substrate for a value document, the security substrate having a front side and a rear side, covering a defined area in top view and having:

a first carrier film (10) extending over at least 50% of the determined area,

-a first opaque layer (17) arranged over the first carrier film (10), the first opaque layer covering at least 25% of the determined area,

-a first print receptive layer (18) arranged over the first opaque layer (17) and

-at least one relief structure (11) arranged between the first opaque layer (17) and the first carrier film (10) and provided with a reflection-enhancing coating (15) acting jointly or separately with the relief structure (11) to achieve an optically variable effect,

characterized in that the first opaque layer (17) is arranged on a second carrier film (20) between the first opaque layer (17) and the relief structure (11).

2. A security substrate as claimed in claim 1, characterized in that the value document is a banknote (1), a cheque, a payment card or a certificate card.

3. A security substrate as recited in claim 1, wherein said first opaque layer covers greater than 50% of said defined area.

4. A security substrate as recited in claim 1, wherein said first opaque layer covers greater than 75% of said defined area.

5. A security substrate for a value document, the security substrate having a front side and a rear side, covering a defined area in top view and having:

a first carrier film (10) extending over at least 50% of the determined area,

-a first printed landing layer (18) arranged over the first carrier film (10), the first printed landing layer (18) being opaque and covering at least 25% of the determined area, and

-at least one relief structure (11) arranged between the first print receptive layer (18) and the first carrier film (10) and provided with a reflection-enhancing coating (15) acting jointly or separately with the relief structure (11) to achieve an optically variable effect,

characterized in that the first print receptive layer (18) is arranged on a second carrier film (20) between the first print receptive layer (18) and the relief structure (11).

6. A security substrate as claimed in claim 5, characterized in that the value document is a banknote (1), a cheque, a payment card or a certificate card.

7. A security substrate as claimed in claim 5, characterized in that the first print receptive layer (18) covers more than 50% of the defined area.

8. A security substrate as claimed in claim 5, characterized in that the first print receptive layer (18) covers more than 75% of the defined area.

9. A security substrate as claimed in any one of claims 1 to 8, characterized in that at least one coloured first printing element (29) is applied to the first print-receptive layer (18).

10. A security substrate as claimed in one of claims 1 to 8, characterized in that a second opacifying layer (22) is arranged on the opposite side of the relief structure (11) to the first opacifying layer (17) or the first print-receiving layer (18), and that this side is also provided with a second print-receiving layer (23) and a coloured second printing element (32) applied thereto.

11. A security substrate as claimed in any one of claims 1 to 8, characterized in that a window (24) is provided in the first opacifying layer (17) or in the first print-receptive layer (18), so that the security substrate becomes transparent in the region of the window (24) or the relief structure (11) with the reflection-enhancing coating (15) is visible through the window (24) in the first opacifying layer (17) or in the first print-receptive layer (18).

12. A security substrate as claimed in claim 10, characterized in that a window (24) is provided in the first opacifying layer (17) or the first print receptive layer (18) and/or in the second opacifying layer (22), so that the security substrate becomes transparent in the region of the window (24) or the relief structure (11) with the reflection-enhancing coating (15) is visible through the window (24) in the opacifying layers (17, 22) or the first print receptive layer (18).

13. A security substrate as claimed in claim 12, characterized in that the first opacifying layer (17) and the second opacifying layer (22) or the window (24) in the first print-receptive layer (18) at least partly overlap in top view.

14. A security substrate as claimed in any one of claims 1 to 8, characterized in that the first opaque layer (17) or the first print receptive layer (18) is a white layer.

15. A security substrate as claimed in claim 10, characterised in that the second opacifying layer (22) is a white layer.

16. A security substrate as claimed in one of claims 1 to 8, characterized in that the relief structures (11) are designed as subwavelength structures (13) in sections and have a periodicity of 150nm to 500nm there or a structure width of 150nm to 500nm there aperiodically.

17. A security substrate as claimed in any one of claims 1 to 8 in which the first opacifying layer (17) or the first print-receptive layer (18) has a laterally structured opacity such that a light/dark view is visible when viewed in transmitted light.

18. A security substrate as claimed in claim 10 in which the second opacifying layer (22) has a laterally structured opacity such that a light/dark view is visible when viewed in transmitted light.

19. A security substrate as claimed in claim 10, characterized in that a further layer having a laterally structured opacity is arranged between the first opacifying layer (17) or the first print receptive layer (18) and the second opacifying layer (22), so that a light/dark view is visible when viewed in transmitted light.

20. A security substrate as claimed in claim 19, characterized in that the further layer is formed by an enhanced reflective coating (15) which is provided with recesses or indentations for the lateral structuring of the opacity.

21. A security substrate as claimed in one of claims 1 to 8, characterized in that the first opaque layer (17) or the first print receptive layer (18) is designed as a second print receptive layer (23).

22. A security substrate as claimed in claim 10, characterized in that the second opaque layer (22) is designed as a second print receptive layer (23).

23. A security substrate as claimed in one of claims 1 to 8, characterized in that a gloss chromatic color (28) is printed above or below the reflection-enhancing coating (15), said chromatic color influencing the color impression of the optically variable effect.

24. A security substrate as claimed in any one of claims 1 to 8, characterized in that a perceptible imprint is provided on the outer side of the security substrate.

25. A security substrate as claimed in claim 24 wherein the embossed portion is in the form of an engraved print of steel.

26. A security substrate as claimed in claim 9, characterized in that the coloured first printing element (29) is applied at least regionally over the relief structure (11) and the reflection-enhancing coating (15), so that the optically variable effect appears in a colourity influenced by the printing element (19).

27. A security substrate as claimed in claim 10, characterized in that the coloured second printing element (32) is applied at least regionally over the relief structure (11) and the reflection-enhancing coating (15), so that the optically variable effect appears in a colourity influenced by the printing element (19).

28. A value document having a security substrate according to one of claims 1 to 27, characterized in that the value document is personalized by means of a printing onto the first print-receptive layer (18) and/or onto the second print-receptive layer (23) if present.

29. A value document according to claim 28, wherein the printed portion is a printed serial number (8).