EP2178707B1 - Security document having watermark-like structure - Google Patents

Description

The invention relates to composite security documents and to methods for producing such composite security documents which comprise a document body, wherein the document body is a monolithic laminate body produced from a plurality of layers.

In such composite security documents, a variety of security features may be incorporated so that they can be used as identification documents, e.g. Identity cards, driving licenses, but also in passports, and other documents are used in which value is attached to a high fätschungssicherheit.

From the prior art, paper-based security documents are known in which one of the security features is a so-called watermark. Watermarks are made by structures that are located in a sieve, with which the pulp is scooped out of the water. At locations where the screen is raised, fewer fibers accumulate than at those locations where the screen has recesses. There are more fibers collecting. At the points where there are fewer fibers, the paper is more transparent than at those points where more fibers have collected. In transmitted light, the watermark without technical aids is also easy to recognize for a layman. Modern paper mills are able to display patterns, characters and other graphic representations in different shades of gray. As a result, a simulation of a watermark, eg by an oily substance, almost impossible. However, paper documents have other disadvantages with regard to their security against counterfeiting, so that modern security documents are almost exclusively plastic-based documents in which several layers are fused into a monolithic block in a lamination process. Such a document body is also referred to as a card body, since the security documents are generally transverse to a direction of layering of the individual Layers or foils that are laminated to one another have a greater extent than along the lamination direction, so that the resulting composite security documents have a card shape.

Thus, plastic-based documents are known from the prior art, as they are used, for example, for credit and debit cards, but also as identification documents, e.g. for identity cards and driving licenses, etc., find use. One of the most suitable manufacturing methods for such plastic-based documents is a lamination method of a layer or stack construction in which individual layers stacked on top of each other, such as plastic films, are heated above their glass transition temperature and subjected to high pressure for a long time to form the individual layers monolithic card body to merge. For these composite security documents, no methods are known to incorporate a watermark comparable security feature in the cards.

Although it is known to use embossing plates which impress structures in the outer layers, for example lens structures, in order to produce an angle-dependent representation, as described, for example, in US Pat DE 199 49 945 or the DE 100 36 505 are described. A disadvantage of these embossments, however, is that the stamping plates are very expensive to produce, since the einzuprägenden structures must protrude as negative structures from the plate surface, which makes a production very expensive. In addition, such embossing plates are subject to high wear. A simple variation of the einzuprägenden structures is therefore not readily possible, as each new stamping plates must be made. In particular, a small series production of individualized security documents with embossed structures is therefore not possible according to the current state of the art at a reasonable cost.

From the WO 2005/108110 A1 is a value document, in particular a banknote, with a layer sequence known, into which by the action of laser radiation visually or machine recognizable markings in the form of patterns, letters, Numbers or pictures are introduced. The layer sequence receives a marking layer of a color mixture which has a mixture component absorbing the laser radiation and a mixture component transparent to the laser radiation, the marking being visually and / or mechanically recognizable due to an irreversible change in the optical properties of the color mixture caused by the action of the laser radiation.

The invention is therefore based on the technical object of composite security documents, which is a document body, which is a monolithic laminate body produced from several layers, with a Watermark-like security feature include, and to provide a method for its production, which eliminate the disadvantages described above and in particular allow individualization of the composite security elements in a simpler manner.

The technical problem is solved by an object with the features of claim 1 and a method having the features of claim 9. Further advantageous embodiments of the invention will become apparent from the dependent claims.

The invention is based on the idea of creating hollow relief-like structures inside the composite security document. For this purpose, it is provided according to the invention to create one or more empty cavities in the layer or stack structure prior to lamination. These cavities can be created by recesses in the material to be laminated of the layers. As an empty recess or empty cavity, one is considered which has no material to be laminated or another material in the stack construction and is completely surrounded by plastic material to be laminated. The resulting from the empty recess during lamination structure is referred to as a hollow relief-like structure. The security feature formed in the composite security document is referred to as a hollow-relief-type structure. Thus, there is proposed a composite security document having an internal hollow relief-like structure comprising a document body, the document body being a monolithic laminate body made of several layers, the document body comprising at least one hollow-relief-like structure used in a high-temperature, high-pressure lamination process, from an upper and lower side, formed on a layering direction of the layers, formed in at least one of the layers before the lamination process empty recess is formed. Furthermore, a method for producing a composite security document with a document body is proposed, which comprises the following steps: providing a plurality of layers, arranging the plurality of layers one above the other, and laminating the plurality on top of one another arranged layers in a high-temperature high-pressure lamination process to a monolithic card body, wherein at least one of the plurality of layers at least one recess is introduced and the plurality of layers are arranged so that the at least one recess to a top and a bottom of the superimposed layers is completed and the volume of the recess is empty and the empty recess is preferably evacuated and the lamination is carried out so that a hollow-relief-like structure is formed in the card body. Here, the new knowledge is exploited that above the glass transition temperature of the plastics to which the layers are heated in the high-temperature high-pressure lamination process, can be kept in a viscosity range, which causes a complete fusion of the superimposed layers, but on the other hand The result is that the empty recesses and cavities are not filled so completely by material of the layers that the contours of the recess completely disappear. The plastics are also above the glass transition temperature and at high pressures unable to fill the recess leveling with material, as would be expected for a low viscosity liquid. The recess can therefore be seen slightly lowered with running contours. Although such a watermark-like structure is not at all or only with difficulty recognizable, it is easy to recognize such a watermark-like inner hollow relief-like structure in grazing incidence, in particular in reflection. Such a structure, since it is formed in the interior of the document body, has a high security against counterfeiting.

Recesses can be formed by depressions, ie recesses which do not completely break through the respective layer. Furthermore, recesses may be formed by apertures that completely penetrate a layer and form a passage opening in this layer or represent. Breakthroughs can be made in different ways. Recesses may also be formed by a combination of perforations and depressions in different layers or be.

Particularly preferably, the recess is formed in at least one layer lying in front of the lamination. This ensures that the inner hollow relief-like structure protrudes deep into the document body viewed from one of the surfaces.

Particularly preferably, the recess formed in the inner layer is formed by means of an opening or comprises an opening which penetrates completely through at least one layer, ie. a passage opening through the layer. In one embodiment, the at least one recess comprises at least one opening through at least one layer lying inside during the stratification. The at least one recess is formed in such an embodiment by introducing into at least one of the layers, which becomes or is an inner layer, an aperture which completely penetrates the respective layer.

However, in order to simultaneously provide a tactile security feature, it is provided in one embodiment of the invention that the hollow-relief-like structure comprises a recess perceptible on one of the surfaces. Such a surface-perceptible recess can also be achieved in manufacturing processes in which the recess prior to lamination is deposited only in internal layers, i. is not formed in the layer disposed on a surface of the document body. The advantage of such an embodiment is that the hollow-relief-like structure is perceived not only visually, but also tactile.

Also, parts of a material from which the layers are formed above and / or below the recess (with respect to the layering direction), in addition to the material of the layers; in which the recess is located, used to fill the recess. In particular in the region of the edges of the recesses, "contour changes" thus occur in layers arranged above or below.

In order to make the hollow-relief-like structures visually perceptible in a particularly simple manner, it is provided in a preferred embodiment that an optically variable security feature is incorporated in a region of the at least one hollow-relief-like structure, in particular by a structure with an interference color in a hollow relief-like structure overlapping area printed layer is incorporated between the original recess and the outside of the document body. An optically variable security feature is understood to be any security feature that produces a different impression as a function of a viewing direction. For example, an interference color changes its perceived color depending on the viewing angle. If, for example, a layer arranged above the recess is printed with an interference color in a region which completely covers the recess, the contour changes occurring in this layer due to the filling of the recess result in different angles of incidence or angles of reflection in the region of the edge of the original recess the printed with interference color layer occur. Thus, the security feature is not only visible in a grainy viewing of the document. In the area of the hollow relief-like structure, therefore, different colors appear without the need to change a viewing angle of the document. Thus, a verification of the hollow-relief-like structure is greatly simplified. Preferably, the optically variable security feature is also incorporated in an inner layer, so that a tamper resistance and protection against wear are increased.

In order to produce "grayscale" watermark-like structures in the interior of the document body, it is provided in a preferred embodiment that the at least one hollow-relief-like structure has regions of different material thickness with respect to the direction of the layering, apart from an edge contour. This means that the recess in different areas, which are not edge regions of the recess, ie, are not regions that indicate a contour of the recess in plan view, different thicknesses, with respect to a direction of lamination of the individual comprising layers laminated together. An optical perceptibility is increased by the fact that above or below the recess, an opaque layer, which may be printed, for example, is arranged. That is, preferably, before the lamination, an opaque layer or at least a part of an opaque layer is disposed between the recess and a surface of the layer stack.

A grayscale watermark-like structure can also be introduced into a document body if the document body is formed at least one further hollow-relief-like structure formed by at least one of the preferably inwardly located layers before lamination, which has a geometrical configuration, in particular their extent, with respect to the layering direction, of the at least one hollow-relief-like structure distinguishes.

By providing a plurality of hollow relief-like structures formed separately from one another, it is possible to incorporate a pattern, for example a pixelated pattern, in the document body. The plurality of hollow-relief-like structures arranged in a pattern preferably have different dimensions along the direction of the lamination. The greater the extent along the direction of the layering, the more the layers arranged toward a surface of the document body can be influenced and changed in the region of the recess during lamination. The plurality of hollow-relief-like layers preferably lead to different thicknesses of the card document at the different hollow relief-like structures. However, it is understood that several of the plurality of hollow relief-like structures each have the same extent along the direction of the lamination or lead to the same thickness of the document body in the region of the respective hollow-relief-like structure. This means that the multiplicity of hollow-relief-type structures are produced by means of a multiplicity of recesses, which have a different extent with respect to a laminating direction. The larger the extent of the recess with respect to the direction of the layering, the more the material thickness in the region of the forming hollow-relief-like structure is lower.

The recesses can be produced in a particularly simple manner by punching out internal layers. Punches are particularly easy to make breakthroughs. The advantage of using punched-outs is that they can be easily introduced and a plurality of punch-outs can be made to produce a pattern in a layer. A variation of the pattern is easily possible. As a result, it is also possible to produce individualized document bodies in which, for example, a document body number is introduced via a binary coding which is formed by means of hollow relief-like structures.

In order to produce recesses of different extent with respect to a layering direction, it is provided in a preferred embodiment that the at least one recess and / or the at least one further recess are formed by superimposed punches of a plurality of inner layers. Advantageously, it is thus provided that the at least one recess and the at least one further recess are punched out and additional recesses are introduced into at least one further layer and the at least one layer and the at least one further layer are arranged as inner layers during the layering in such a way that they are covered On the layering direction different numbers of recesses and / or different deep recesses are arranged one above the other, so that form different hollow-relief-like structures of the at least one recess and the at least one further recess. The greater the extent of the recess with the same edge contour, ie extent and shape transverse to the layering direction, the greater the deformations of the layers arranged above and / or below during lamination in the area of the formerly existing recess. Grayscale can be generated in a punched pattern, for example, by punching in several of the layers recesses, so that when stacking the plurality of punched layers as inner layers at different locations different numbers of punched holes are stacked. As a result, different hollow relief-like structures form in the document body. Furthermore, the hollow-relief-like structures in different structures, ie in different planes perpendicular to the layer plane, may be formed in the document body. Likewise, apertures made in a similar manner to apertures may be used to create recesses of varying depth in a stack of layers prior to lamination.

Recesses can be introduced into the layers not only by punching, but also all other techniques can be used, which can effect a layer thickness modulation. These preferably include, in addition to punching, engraving, different laser processing techniques, etc.

In a preferred embodiment of the invention, it is provided that diffractive surface structures are produced on at least one surface of the document body by means of the hollow-relief-like structures. Advantage of this embodiment is that simple punched can be used to produce diffractive surface structures. Elaborate printing plates or stamping plates, as used in the prior art, are not required for this purpose.

In one embodiment of the invention, it is provided that due to the hollow-relief-like structures on one of the surfaces forming depressions are filled by a contrast-generating material. This may be a paint or paste comprising, for example, metallic particles, carbon black or the like. Such an embodiment is able to produce a contrast even in transmitted light. By choosing the filling material, it can be determined whether a contrast in the visible range, UV range or in the infrared wavelength range is formed. It is particularly preferred if In contrast to the rest of the document body material, a contrast is produced both in the visible and in the infrared wavelength range, so that both a simple optical backlight test and a machine test in the infrared wavelength range can take place. Thus, an overprint of the document body with a transparent color in the infrared wavelength range is particularly preferred.

The features of the manufacturing method according to the invention have the same advantages as the corresponding features of the composite security document according to the invention.

Fig. 1a - 1c

einen Ablauf zur Herstellung eines Dokumentkörpers mit einer hohl-reliefartigen Struktur;

Fig. 2a - 2c

schematisch einen Ablauf zur Herstellung eines Verbundsicherheitsdokuments mit einem Dokumentkörper, der ein Muster von hohl-reliefartigen Strukturen zum Ausbilden einer wasserzeichenartigen Gesamtstruktur umfasst; und

Fig. 3a - 3c

schematische Darstellungen eines weiteren Verbundsicherheitsdokuments mit einer Graustufen nachahmenden wasserzeichenartigen Gesamtstruktur aus mehreren hohl-reliefartigen Strukturen.

The invention will be explained in more detail with reference to preferred embodiments. Hereby show:

Fig. 1a - 1c

a process for producing a document body having a hollow-relief-like structure;

Fig. 2a - 2c

schematically illustrates a process for producing a composite security document having a document body comprising a pattern of hollow relief-like structures for forming a watermark-like overall structure; and

Fig. 3a - 3c

schematic representations of another composite security document with a grayscale mimicking watermark-like structure of several hollow relief-like structures.

In Fig. 1a to 1c different process stages for producing a composite security document 1 are shown, which is finished in Fig. 1c is shown. The composite security document 1 comprises a document body 2 made of multiple layers 3-7 in a high-pressure, high-pressure lamination process. This means that the multiple layers 3-7 are using a suitable temperature and pressure profile are laminated. Such methods are known to the person skilled in the art. The in Fig. 1c shown document body is composed of five layers 3-7. Generally, the number of layers used is between 3 and 15, preferably between 5 and 12. The document body 2 has a hollow-relief-like structure 8, which is produced in the high-pressure high-temperature lamination of an empty recess in an inner layer, here a middle layer 5. The hollow-relief-like structure 8 is a watermark-like structure of the composite security document 1.

To produce the hollow-relief-like structure 8, a recess is first incorporated into a layer 5, which is preferably a plastic film. In the example shown, a T-shaped recess 9 is introduced via an opening, which is preferably made by means of a punching. The plastic film is preferably a film having a thickness ≦ 100 μm, preferably ≦ 50 μm and particularly preferably ≦ 35 μm. As in Fig. 1 b, the layer 5 provided with the T-shaped recess 9 is layered as a middle layer between the remaining layers 3, 4 and 6, 7. In order to prevent inclusion of gas molecules, the layers are preferably carried out in vacuo. As a result, the empty space in the recess 9 is evacuated. In stacked state is thus the empty and evacuated recess in the middle of the layer stack 10. It is surrounded on all sides by plastic material of the layers 3,4,5. The layer stack 10 is now in a high-pressure high-temperature lamination process to a monolithic document body 2, the in Fig. 1c is shown merged. In this case, the individual layers 3-7 are heated to a temperature above the glass transition temperature of the individual plastics of which the layers 3-7 are made. As plastic layers in particular plastic films with high softening temperature are used. Especially preferred are polyethylene terephthalate and its derivatives, and particularly preferably polycarbonates, in particular bisphenol A polycarbonate. Furthermore, relevant known thermoplastically processable plastics such as polyvinyl chloride, acrylonitrile-butadiene-styrene and a composite material such as Teslin are used. These are preferably heated to temperatures ≥ 100 ° C, preferably to temperatures ≥ 120 ° C and most preferably to temperatures above 140 ° C. At the same time, the layers are pressed together by high pressure. The pressure is applied parallel to a direction of lamination 11. That is, the upper layer 3 and the lower layer 7 adjacent elements exert a pressure on the films, so that they are pressed parallel to the laminating direction 11 to each other. In this case, pressures of more than 50 bar are typically used. Despite the heating above the glass transition temperature and the application of the high pressure, the T-shaped recess is not completely filled by material of the middle layer 5 as well as material of the overlying layer 4 and underlying layer 6 so that a homogeneous card body in the region of the recess results. Rather, a hollow-relief-like structure 8 remains, which results from the fact that parts of the material of the overlying layer 4 and / or the underlying layer 6 are virtually drawn into the recess 9. In the finished document body 2, the originally T-shaped contour 12 of the recess 9 washed out is still discernible as a blurred or washed-out contour 13. This is in Fig. 1c indicated by a dashed representation of the washed-out contour 13. In the recess material of the overlying layers 3, 4 and / or the underlying layers 6, 7 penetrated. Depending on the different layer thicknesses, this can lead to the hollow-relief-like structure 8 being perceptible as a depression on a surface 14 of the document body 2.

It has proven to be particularly advantageous to arrange an opaque layer, here the layers 4 and 6, between the recess 9 and the upper side 15 and / or the lower side 16. These opaque layers 4 and 6 may be printed, for example. As a result, the recognizability of the inner hollow relief-like structure is increased. It has proven to be particularly advantageous to print these layers 4, 6 with an interference ink, for example, at least in the region covering the T-shaped recess 9. An interference color is an optically variable feature that can be used as a security feature. By arranged in the lowering of material over the recess 9 layer 4, which is printed with the interference color, there is a deformation of this layer 4, so that in particular in the area of the blurred contour 13 "bends" of the printed layer occur. As a result, the hollow-relief-like structure 8 is made well visible not only under grazing viewing angle. The hollow-relief-like structure produces a characteristic appearance and / or a characteristic color spectrum at a fixed viewing angle. Changing the viewing angle usually changes the appearance and the color spectrum.

In Fig. 2a to 2c schematically the production of a further composite security document 1 'is shown schematically. In a layer formed as a film 5 'a plurality of recesses 17 are introduced, which form a pattern. The recesses 17 may preferably be punched. However, any other methods, such as laser processing methods, may be used to insert the recesses 17 into the film. For example, the recesses do not have to completely penetrate the film, ie represent through openings. Preferably, however, the recesses are formed as openings of the films.

The layer 5 'is then layered over films 7 and 6 formed as films. Over layer 5 'further layers 4 and 3 formed as films are layered. As in the embodiment according to Fig. 1 For example, the films are preferably stacked under vacuum conditions so that the recesses 17 are evacuated. As in the embodiment according to Fig. 1a to 1c For example, the layers 3, 4, 5 ', 6, 7 are fused into a monolithic document body 2' in a high-pressure, high-temperature lamination process. A variation of an extent of the individual recesses 17 in the layer 5 'and over a distance of the recesses 17, an optical impression can be varied. This makes it possible to produce gray scale-like watermark-like overall structures which consist of individual hollow-relief-type structures 8 '.

In Fig. 3a to 3c schematically shows the production of a further composite security document 1 "In this embodiment, recesses are introduced in two layers 5" and 5 '", which are formed as apertures, which are again preferably punched in. The layers 5" and 5'"become Subsequently, the layers 5 "and 5"'are arranged so that some of the recesses 18 of the layer 5 "are arranged over recesses 19 of the layer 5"'. and a recess 21 in the layer 5 '"are not arranged one above the other, resulting in a layer stack 10 recesses of different dimensions along the layering direction 11. The layering is again preferably under vacuum conditions, so that the resulting recesses, which partially consist of two recesses 18, 19 are formed, are empty and each up and down by one over it / underlying, preferably opaque, layer 6, 4 are completed. In a subsequent high-pressure, high-temperature lamination process, the individual layers 3, 4, 5 ", 5"', 6, 7 are fused to form a document body 2 "of the composite security document 1". In this monolithic document body 2 "different hollow-relief-like structures 23, 24, 25 are formed, which are formed differently, since the recesses from which they originated, had different dimensions before lamination The hollow-relief-like structures 24, the The recesses 18, 19 of the layers 5 ", 5 '", which are formed parallel to the direction of lamination 11 of a greater extent, form the above and below layers 3, 4 and 6, 7 more strongly than they The hollow-relief-like structures resulting from the recesses 20, 21 have a smaller extent parallel to the direction of layering 11. Further, the hollow-relief-like structures 23 and 25, which consist of the recess 20 in layer 5 "and the recess 21 in layer 5" In this way, the visual impression of the individual hollow-relief-like struc Doors 23, 24, 25 different, especially if in the hollow-relief structure, an opaque layer, as here the layers. 4 and 6 are included, which are printed, for example, with an optically variable security feature, such as an interference color.

If the hollow-relief-like structures are formed so that tactilely perceptible depressions form on an upper side 15 and / or lower side 16, they can in one embodiment be filled with a substance producing a contrast. For example, pastes or gels may be incorporated in these recesses, which include soot particles, metal particles, etc. As a result, contrast formation in different wavelength ranges can be achieved. In a preferred embodiment, similar to the embodiments according to Fig. 2a to 2c and 3a to 3c the patterns introduced into the layers 5 'or 5 "and 5"' are varied so that individualized card bodies are produced. For example, information about the extent of the recess along the direction of layering before the lamination process can be encoded. If, for example, a binary value 0 is assigned to the recesses formed by the recesses 20 or 21 in the films 5 "and 5 '", then the recesses formed by the superimposed recesses 18, 19 in the layers 5 "and 5"' can have a binary number 1 be assigned. By this it is now possible to encode any binary numbers into the card body. It will be apparent to those skilled in the art that not only binary encodings but much more complex encodings can be incorporated into the document body. It should be emphasized that individualized punching out of the layers are easy to accomplish.

The punching or the introduction of breakthroughs can also be done in the opaque layer, so that the security feature is to be considered in transmitted light. In this case, either all the opaque layers can have recesses, resulting in hollow relief-like structures in the form of transparent transparent windows, or only individual opaque layers having recesses prior to lamination. In the second case, translucent hollow relief-like structures result. It will be apparent to those skilled in the art that in other embodiments, both transparent and translucent hollow-relief-like structures can be formed in a document body.

The described embodiments are merely exemplary embodiments. The individual described features of the various described embodiments may be combined in any combination for realizing the invention. The described composite security document may be a complete security document. In other embodiments, for example, it may be included in a "higher level" security document, such as a passbook.

LIST OF REFERENCE NUMBERS

1, 1 ', 1 "

Laminated safety document

2, 2 ', 2 "

document body

3, 4, 5, 5 ', 5 ", 5"', 6, 7

layers

8, 8 '

hollow-relief-like structure

9

recess

10

layer stack

11

layering direction

12

contour

13

blurred contour

14

surface

15

top

16

bottom

17, 18, 19, 20, 21

recesses

23, 24, 25

hollow-relief-like structures

Claims (15)

1. Composite security document (1, 1', 1") with a hollow relief structure (8, 8', 23, 24, 25), comprising a document body (2, 2', 2"), wherein the document body (2, 2', 2") is a monolithic laminate body formed from a plurality of layers (3-7),
   characterised in that
   the document body (2, 2', 2") comprises at least one hollow relief structure (8, 8', 23, 24, 25), which is formed in a high-pressure high-temperature lamination process from an empty recess (9; 17; 18-21) formed before the laminating process in at least one of the layers (3-7) enclosed to an upper and lower side (15, 16) related to a layering direction (11) of the layers (3-7).
2. Composite security document (1, 1', 1 ") according to claim 1, characterised in that the at least one recess (9; 17; 18-21) is formed in at least one layer (5, 5', 5", 5"') lying in the interior in the layering.
3. Composite security document (1, 1', 1") according to claim 1 or 2, characterised in that the hollow relief structure (8, 8'; 23, 24, 25) comprises an indentation which is perceptible on one of the surfaces (14).
4. Composite security document (1, 1', 1") according to any one of claims 1 to 3, characterised in that in an area of the at least one hollow relief structure (8, 8'; 23, 24, 25) an optically variable security feature is integrated, in particular in that a layer printed with an interference ink in an area covering the hollow relief structure (8, 8'; 23, 24, 25) is integrated between the original recess (9; 17; 18-21) and the surface (14) of the document body (2).
5. Composite security document (1, 1', 1") according to any one of claims 1 to 4, characterised in that the at least one hollow relief structure (8, 8'; 23, 24, 25), apart from an edge contour (13), exhibits areas of different extension related to the layering direction (11).
6. Composite security document (1, 1', 1") according to any one of claims 1 to 5, characterised in that at least one further hollow relief structure (8, 8'; 23, 24, 25) is formed in the document body (2) on the basis of a further empty recess located in at least one of the preferably interior located layers (5, 5', 5", 5"') before the lamination, said structure differing in respect of its geometrical design, in particular its extension in relation to the layering direction (11), from the at least one hollow relief structure (8'; 24).
7. Composite security document (1, 1', 1") according to any one of claims 1 to 6, characterised in that the at least one hollow relief structure (8, 8'; 24) formed from the at least one recess (9, 17, 18, 19) comprises mirror-image indentation on the opposite side of the document body (2).
8. Composite security document (1, 1', 1") according to any one of claims 1 to 7, characterised in that the at least one recess (9; 17; 18-21) comprises at least one break through in at least one layer (5, 5', 5", 5"') located inside the layering.
9. Method for producing a composite security document (1 1', 1 ") with a document body (2), comprising the following steps:

   Preparation of a plurality of layers (3-7);

   Arrangement of the plurality of layers (3-7) above one another;

   Lamination of the plurality of layers (3-7) arranged above another in a high-pressure high-temperature laminating process to form a monolithic document body (2), characterised in that

   at least one recess (9; 17; 18-21) is introduced into at least one of the plurality of layers (3-7), and the plurality of layers (3-7) are arranged in such a way that the at least one recess (9; 17; 18-21) is enclosed to an upper and a lower side (15, 16) of the layers (3-7) arranged above one another, and the volume of the recess (9; 17; 18-21) is empty, and the at least one empty recess (9; 17; 18-21) is evacuated, and the lamination is carried out in such a way that a hollow relief structure (8, 8'; 23, 24, 25) is formed in the document body (2).
10. Method according to claim 9, characterised in that a layer (4, 6), arranged between the at least one layer (5, 5', 5", 5"') provided with at least one recess (9; 17; 18-21) and a surface (14), comprises an optically variable security feature in an area covering the recess (9; 15; 18-21), and is in particular printed with an interference ink.
11. Method according to claim 9 or 10, characterised in that the at least one recess exhibits areas of different depths related to the layering direction (11).
12. Method according to any one of claims 9 to 11, characterised in that, in the at least layer (5', 5", 5"') provided with the at least one recess (19), at least one further recess is formed before the lamination, which differs from the at least one recess in respect of its geometrical arrangement, in particular its depth related to the layering direction (11).
13. Method according to any one of claims 9 to 12, characterised in that the at least one recess (18) and the at least one further recess (20) are punched out of the at least one layer (5") and that additional recesses (19, 24) are introduced into at least one further layer (5"'), and the at least one further layer (5"') is arranged during the layering as inner layers, that, related to the layering direction (11), a differing plurality of recesses (18-21) and/or recesses of differing extension are arranged above one another, such that different hollow relief structures (23, 24, 25) are formed in the document body (2).
14. Method according to claim 13, characterised in that the at least one hollow relief structure (8) is designed in such a way that at least one tactile perceptible indentation is formed at the surface (14), and the at least one perceptible indentation is filled with a contrast-forming material.
15. Method according to any one of claims 9 to 14, characterised in that, in the at least one recess (9; 17; 18-21) is formed in that a break through is introduced into at least one of the interior located layers (5, 5', 5", 5"') which completely penetrates the respective layer (5, 5', 5", 5"').

Images