Method for producing a laminate and laminate and security or value document with an internal security feature

Abstract

Method for producing a laminate (11) with an internal safety feature (12), - in which at least one translucent or opaque substrate layer (14) is provided, - in which at least one further translucent or transparent layer (21, 22) is provided, - in which at least one substrate layer (14) and at least one further layer (21, 22) are brought together and laminated to form a laminate (11), - wherein recesses (16) are provided in a top (17) and / or bottom (18) of the at least one substrate layer (14) before being joined with the at least one further translucent or transparent layer (21, 22), and - wherein at least one transparent or translucent layer (21, 22) is applied to the top (17) and / or bottom (18) of the substrate layer (14) which is provided with depressions (16) and at least one subset of the depressions (16) is filled with the at least one transparent and / or translucent layer (21, 22), and the at least one subset of the filled depressions (16) forms the internal security feature (12), characterized in that - that after the indentations (16) have been introduced into the substrate layer (14) and before being combined with at least one further translucent or transparent layer (21, 22), at least a subset of the indentations (16) are provided with at least one functional material.

Description

[0001] The invention relates to a method for producing a laminate with an internal security feature and to a laminate with such an internal security feature.

[0002] From DE 10 2011 004 935 A1, a laminate with an internal security feature is known. This laminate comprises a middle opaque substrate layer and further layers, which are transparent and / or translucent, applied to each outer surface of the substrate layer. Microperforations are incorporated into the opaque substrate layer. These microperforations are filled with at least two outer layers that cover the microperforations.

[0003] From DE 32 31 460 A1, a multi-layered identification card is known which comprises several plastic layers bonded under heat and pressure. An inner interface of at least one of these layers has depressions which are filled with the material of the respective adjacent layer during the lamination process.

[0004] US patent 2005 / 0035589 A1 describes a multi-layered structure for an identification card. Embedded within this multi-layered structure is a raster image containing security features, which becomes visible when light shines upon it.

[0005] A multi-layered composite is known as a security document from WO 2017 / 177328 A1. Before the layers are laminated together, a microstructure is pressed onto the top surface of an inner layer.

[0006] From DE 10 2010 015 778 A1 a security element for security paper is known which has an image area that shows a predetermined multitonal motif when viewed through it.

[0007] There is a continuing need to create such security features for security documents that offer increased protection against forgery and make manipulation more difficult.

[0008] The invention is based on the objective of creating a method for producing a laminate as well as a laminate and a security document in which an internal security feature enables increased protection against forgery and manipulation.

[0009] This problem is solved by a method for producing a laminate with an internal security feature, wherein the laminate comprises at least one translucent or opaque substrate layer and at least one further translucent or transparent layer, which are laminated to form a laminate, wherein depressions are provided in a top and / or a bottom of the at least one substrate layer before being joined with the at least one further transparent or translucent layer, and then the at least one transparent or translucent layer is applied to the top and / or bottom of the substrate layer having depressions, and at least a subset of the depressions are filled with the at least one transparent or translucent layer.This creates an internal security feature, preferably a see-through feature, through at least the subset of filled recesses. Different optical transmittances can be achieved through the recesses, thus creating a see-through feature in the form of a watermark. This see-through feature can be generic or individualized, for example, as a serial number, image, logo, name, designation, and / or the like. If the substrate layer is opaque, the at least one additional layer can be translucent or transparent. If the substrate layer is translucent, the at least one additional layer can be transparent or have a higher light transmittance than the substrate layer.

[0010] Preferably, the depression in the substrate layer is created by partially removing material from the substrate layer. For example, such partial removal can be achieved by drilling, countersinking, or laser irradiation, in particular with a CO2 laser. Chemical processes can also be used to achieve partial removal.

[0011] Alternatively, the indentations in the substrate layer can be created by partially displacing material from the substrate layer. This can be achieved through embossing, stamping, or similar processes.

[0012] At least a subset of the depressions, in particular all depressions in the top and / or bottom of the translucent or opaque substrate layer, are filled with at least one further transparent or translucent layer covering the depressions during lamination. This creates a monochromatic see-through feature in the laminate. Preferably, the layer covering the depressions can have a translucency or opacity that differs from that of the substrate layer.

[0013] After creating the indentations in at least one translucent or opaque substrate layer and before merging with at least one further translucent or transparent layer, a predetermined number of the indentations are partially or completely filled with at least one functional material. This allows for the creation of various characteristics. For example, a security feature can be partially colored and partially colorless. Furthermore, depending on the specific functional materials used, security features with different optical signals can be created when stimulated with a specific wavelength and / or a magnetic force. Fluorescent or luminescent materials can be used as functional materials. A magnetic material, a material containing metal particles, or any combination thereof can also be used.

[0014] Furthermore, it may be preferable to provide for the cavities to be partially or completely filled with the functional material. This can increase counterfeit protection by, for example, having one cavity, or a specific number or selection of cavities, only half-filled, while another number or selection of cavities are completely filled. Further variations in the fill level of the cavities are also possible.

[0015] Furthermore, it is preferably provided that one or more functional materials are applied to the recesses and to the surface sections extending between the recesses. This allows individual surface sections and recesses to be completely covered with at least one functional material. This enables further design variations of the internal security feature.

[0016] Preferably, at least one functional material is applied by squeegeeing, printing or laminating.

[0017] Preferred printing methods include letterset, gravure (raster gravure) or offset printing, as well as non-impact printing methods such as inkjet printing.

[0018] A further advantageous embodiment of the method provides that different shades of gray are produced in the at least one translucent or opaque substrate layer by adjusting the size, depth, shape, fill level, and / or areal density of the depressions. This allows, for example, the creation of a grayscale gradient or a kind of shading in such a transparency feature, particularly with identical transmission properties of the transparent or translucent layer to be applied.

[0019] The laminate is preferably made from at least one substrate layer and at least one transparent or translucent layer, wherein the substrate layer has a higher melting point than the at least one further layer. This ensures that the indentations are largely maintained during the lamination of the at least one further layer to the substrate layer, thus preserving the shape and / or form of the at least one security feature.

[0020] A further advantageous embodiment of the method provides that, prior to the creation of the depressions in the at least one opaque or translucent substrate layer, a pattern or grid is applied to the top and / or bottom surface of the substrate layer using a material that has a higher melting point than the opaque or translucent substrate layer. This pattern or grid remains intact when the at least one depression is created in the top and / or bottom surface of the opaque or translucent substrate layer. For example, such a pattern or grid can be formed by geometric shapes such as lines, squares, triangles, or the like. This applied pattern or grid consists, for example, of silver or another metallic material. Other materials with a higher melting point than the substrate layer can also be used.To connect the individual geometric shapes to form a security feature, at least one indentation can be incorporated between them. This indentation in the opaque or translucent substrate layer is only removed in the uncoated area. The applied pattern or grid remains on the substrate layer. Subsequently, this top and / or bottom surface, which encompasses the applied pattern with the indentations, can be covered with a translucent or transparent layer and laminated.

[0021] The problem underlying the invention is further solved by a laminate with an internal security feature, in which the laminate comprises at least one translucent or opaque substrate layer and at least one translucent or transparent layer, which are laminated together, wherein recesses are formed in the substrate layer, and at least a subset of the filled recesses forms the internal security feature. This internal security feature is protected against tampering due to the translucent or transparent layer applied to it. Furthermore, a security feature verifiable by transmitted light can be created, the effort required for counterfeiters to create is significantly increased, or a counterfeit is easily detectable.

[0022] Preferably, at least one recess in the opaque or translucent substrate layer is filled with at least one further transparent or translucent layer. This represents a simple embodiment of such an internal security feature in the laminate.

[0023] The recesses of the translucent or opaque substrate layer are preferably partially or completely filled with at least one functional material. Fluorescent or luminescent materials can be used as functional materials. A magnetic material, a material containing metal particles, or any combination thereof can also be used. For example, by changing the fill level in the respective recess, a specific optical property can be achieved, such as altering the transmittance. Additionally, a single- or multi-colored transparency feature can be created by selecting the functional features, such as colored particles.

[0024] Furthermore, it is preferably provided that a predetermined number or selection of the introduced depressions are filled. This can also increase the counterfeit protection, provided the number of filled depressions is selected accordingly.

[0025] Furthermore, it is preferably provided that a layer of a functional material is included which at least partially covers the depressions as well as the intervening surface sections. The depressions and the intervening surface sections can also be at least partially or additionally covered with at least one transparent or translucent layer.

[0026] The problem underlying the invention is solved by a valuable or security document comprising a laminate with an internal security feature. The laminate consists of at least one translucent or opaque substrate layer and at least one transparent or translucent layer laminated together. Indentations are formed in the at least one substrate layer, and at least a subset of these indentations are filled with the transparent or translucent layer, forming the internal security feature. This internal feature makes any tampering easily detectable, significantly increasing the effort required for counterfeiters.

[0027] The invention, as well as further advantageous embodiments and developments thereof, are described and explained in more detail below with reference to the examples shown in the drawings. The features that can be derived from the description and the drawings can be applied individually or in any combination according to the invention. The drawings show: Fig. 1 a schematic sectional view of a first work step in the production of a laminate, Fig. 2 a schematic sectional view of a second work step in the production of a laminate, Fig. 3 a schematic sectional view of a first embodiment of the laminate, Fig. 4 A schematic sectional view of a substrate layer with depressions for a laminate, Fig. 5 a schematic sectional view of a work step for filling the depressions in the substrate layer, Fig. 6 A schematic sectional view of an alternative embodiment for filling the depressions in the substrate layer as shown in Fig. 5, Fig. 7 A schematic cross-sectional view of the laminate after the work steps in Fig. 4 and Fig. 6, Fig. 8 a schematic sectional view of an internal safety feature of the laminate according to Fig. 3, and Fig. 9 A schematic view of a substrate layer for the production of an alternative internal security feature.

[0028] In the Fig. Sections 1 to 3 below describe a process for manufacturing a laminate 11 with an internal safety feature 12, which includes the following individual steps:

[0029] First, a substrate layer 14 is provided. This substrate layer 14 can be opaque or translucent. This substrate layer 14 can have a thickness of 50 to 300 micrometers, preferably a thickness of 70 to 200 micrometers, and particularly a thickness of 80 to 150 micrometers. For example, this substrate layer 14 is made of a thermoplastic polymer material, in particular polycarbonate.

[0030] In a first step according to Fig. 1. This substrate layer 14 is processed to create depressions 16. These depressions 16 can be designed as blind holes. Likewise, the depressions 16 can have a semicircular or arc-shaped contour. Other geometric shapes for the depressions 16 are possible. In any case, a perforation, i.e., a fully formed through-hole, is not to be understood as a depression 16.

[0031] In a first embodiment, the recess 16 can be formed by partially removing material from the substrate layer 14. For example, drilling or countersinking can be performed. In particular, processing is carried out using a laser beam. Depending on the number of pulses or the power of the laser beam and its focusing, the size, depth, and / or shape can be determined. Particularly when the substrate layer 14 is opaque, different shades of gray for an internal security feature 12 can be achieved by varying the depth, diameter, and / or shape of the recesses 16.

[0032] In the exemplary embodiment according to Fig. 1. The recesses 16 are provided only on a top surface 17. Alternatively, these recesses can also be provided only on a bottom surface 18. Furthermore, it is possible to provide the recesses 16 on both the top surface 17 and the bottom surface 18. These are preferably aligned to avoid a through-hole. Additionally, this allows a specific transmission level for an internal safety feature to be achieved.

[0033] In Fig. Figure 2 schematically illustrates a second work step. At least on the upper and / or lower surface 17, 18 of the substrate layer 14, which is provided with depressions 16, a further layer 21 is applied. This layer 21 can be translucent or transparent. Several layers 21, differing from one another, can also be applied. In the exemplary embodiment, a further layer 21, 22 is applied to both the upper surface 17 and the lower surface 18 of the substrate layer 14.

[0034] The at least one substrate layer 14 preferably has a higher melting point than at least one further transparent or translucent layer 21, 22.

[0035] In a subsequent step according to Fig. 3. Layers 21, 22, and the substrate layer 14 are laminated to form laminate 11. During this lamination process, the recesses 16 are filled by at least one layer 21. This creates an internal security feature 12 formed by the recesses 16. This internal security feature 12 can be designed like a watermark. If the layers used do not include any coloring, the design of the recesses 16 can create a security feature 12 with different shades of gray, since larger recesses appear lighter when viewed through them than smaller recesses or shallower recesses.

[0036] The further translucent or transparent layers 21, 22, which form the laminate 11v, can also consist of a thermoplastic polymer material like the substrate layer 11, with the melting point of the substrate layer 14 being higher than that of the further layers 21, 22. This has the further advantage that a kind of monolithic laminate can be formed after lamination. The further layers 21, 22 can have the same degree of transmission or differ from each other.

[0037] Such a Laminate 11 can be designed as a security document. Security documents include, for example, ID documents, passports, identity cards, identification cards, driver's licenses, vehicle registration documents, vehicle titles, registration certificates, company ID cards, bank cards or credit cards, access cards, visas, but also counterfeit-proof labels, tickets, banknotes, postage stamps, securities or similar items.

[0038] Thermoplastic polymer materials for such a laminate 11 are defined as materials that are plastically deformable within a specific temperature range. Examples of thermoplastic polymer materials include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyvinyl chloride (PVC), acrylonitrile butadiene styrene (ABS), polyamides (PA), polyacetate (PLA), polymethyl methacrylate (PMMA), polycarbonate (PC), polyethylene (PE), polypropylene (PP), polystyrene (PS), and polyetherketone (PEEK).

[0039] Likewise, thermoplastic elastomers (TPE), in particular thermoplastic polyurethane (TPU), can be used as thermoplastic materials for the production of a laminate 11.

[0040] The material layer for the at least one further layer 21, 22 can be in a range between 10 and 200 micrometers, preferably 20 to 70 micrometers.

[0041] A layer is described as transparent if it allows light, i.e., electromagnetic radiation, of a specific wavelength or range of wavelengths to pass through in the form of directed radiation. Directed radiation exhibits an intensity distribution that is high only within a contiguous, limited solid angle. In the remaining solid angles, the intensity is significantly weaker, typically by several orders of magnitude, preferably close to zero. When such directed radiation passes through a transparent material, the property of intensity being concentrated within a limited solid angle is retained. While the solid angle may increase, significant diffuse scattering does not occur. However, a reduction in the intensity of the radiation passing through the transparent area or region can occur.Through a transparent material, an image can be formed according to geometric optics.

[0042] A material is described as translucent if it no longer possesses the described property of preserving its directional characteristics. Primarily through diffuse scattering, the originally directed radiation becomes radiation whose intensity distribution exhibits a clearly perceptible intensity over a large solid angle. While an increase in intensity within or around the angular range associated with the original direction of propagation of the directed radiation is possible, it no longer amounts to several orders of magnitude.

[0043] Opacity is defined as the property that prevents the transmission of light, i.e., electromagnetic radiation, at least for one wavelength or one or more wavelength ranges. To determine whether an object or region of space is transparent or opaque, it is essential to specify the wavelength or wavelength range for which this property is being investigated or applies. For example, many materials are transparent in the visible wavelength range but opaque in the ultraviolet wavelength range.

[0044] Terms such as opaque, translucent and transparent refer to the property of the material layer after lamination, or, in the case of a substrate layer, to the property of the material layer formed from it after lamination.

[0045] In the Fig. Steps 4 to 7 are individual work steps for the production of an alternative laminate 11 to Fig. 3 shown. Fig. 4. The substrate layer 14 is already processed and has depressions 16. These depressions 15 can be produced as in the embodiment described above. Alternatively, these depressions 16 can be... Fig. 1. are introduced by embossing, stamping, or the like. In this latter case, material displacement takes place to form the recesses 16. Subsequently, according to a first embodiment, in Fig. 5. The recesses 16 and surface sections 23 located between the recesses 16 are coated and filled with a functional material. For example, this full-surface filling of the recesses and the full-surface application of the functional material can be achieved by squeegeeing, screen printing, foiling, or by other known printing processes and the like.

[0046] Alternatively, according to Fig. 6. It is provided that only the recesses 16 are filled. This can be done, for example, by non-contact high-performance spraying, in particular jetting, or by introducing spheres or the like. In the embodiment according to Fig. 6. Furthermore, it may be provided that each recess 16 has a specific fill level. For example, adjacent recesses 16 may have different fill levels. Likewise, individual sections of recesses 16 may have a specific fill level that differs from the fill level in an adjacent section of recesses 16.

[0047] Functional materials can include, for example, colors. Fluorescent, luminescent, magnetic, and / or metallic materials can also be incorporated. Subsequently, at least one further layer 21 is applied to the substrate layer 14 with the filled depressions 16. Preferably, a transparent layer 21 is applied as a cover layer or top layer. The individual layers 21, 22, and 14 are then laminated to form a laminate 11 according to [reference to relevant section]. Fig. 7.

[0048] In Fig. Figure 8 shows a schematic view of an exemplary internal safety feature 12 of the laminate 11. This view shows a safety feature 12, which, for example, according to the Fig. 1 to 3 is constructed and manufactured. The different sizes, depths, shapes, fill levels, and / or surface density of the depressions 16 allow, for example, the creation of a letter, shown here as "B". This letter can have a clearly visible outline. This outline is formed by depressions 16 that are large in diameter and / or deep. Shading can be incorporated within the outline by using smaller depressions and / or depressions with a shallower depth.

[0049] In Fig. Figure 9 is a schematic view of a substrate layer 14 with an alternative embodiment of an internal security feature 12 in Fig.Figure 8 illustrates this process. A pattern or grid is applied, in particular printed, to the substrate layer 14. For example, a grid is formed from square or rectangular areas 26, which are made of silver, for instance. Subsequently, the substrate layer 14 is ablated using a laser. In this exemplary embodiment, the resulting indentations 16 are each located in a corner region of the square area 26. Since the laser power of the laser beam is set such that material from the substrate layer 14 can be ablated, but the material of the grid 26 is not affected, the pattern shown, in which an indentation 16 connects four corner regions of the square areas 26, can be produced. This is just one of many exemplary embodiments for the production of an internal security feature 12 in which indentations 16 are incorporated.It is understood that further internal security features 12 may be combined, connected or integrated with the recesses 16. Reference symbol list 11 Laminat 12 security features 14 Substrate layer 16 In-depth study 17 Top of 14 18 bottom of 14 21st shift 22nd shift 23 Area section 25 grids 26 Rectangular area

Claims

[1] Method for producing a laminate (11) with an internal security feature (12), - in which at least one translucent or opaque substrate layer (14) is provided, - in which at least one further translucent or transparent layer (21, 22) is provided, - in which at least one substrate layer (14) and at least one further layer (21, 22) are brought together and laminated to form a laminate (11), - wherein recesses (16) are provided in a top (17) and / or bottom (18) of the at least one substrate layer (14) before being joined with the at least one further translucent or transparent layer (21, 22), and - wherein at least one transparent or translucent layer (21, 22) is applied to the top (17) and / or bottom (18) of the substrate layer (14) which is provided with depressions (16) and at least one subset of the depressions (16) is filled with the at least one transparent and / or translucent layer (21, 22), and the at least one subset of the filled depressions (16) forms the internal security feature (12), characterized by , - that after the indentations (16) have been introduced into the substrate layer (14) and before being combined with at least one further translucent or transparent layer (21, 22), at least a subset of the indentations (16) are provided with at least one functional material. [2] Method according to claim 1, characterized by , that the depressions (16) in the substrate layer (14) are produced by partially removing material from the substrate layer (14). [3] Method according to claim 1, characterized by , that the depressions (16) in the substrate layer (14) are produced by a partial displacement of material from the substrate layer (14). [4] Method according to any one of the preceding claims, characterized by , that the depressions (16) of the substrate layer (14) are filled with at least one further transparent or translucent layer (21, 22) during lamination. [5] Method according to any one of the preceding claims, characterized by , that at least a subset of the depressions (16) in the substrate layer (14) are filled with at least one functional material to a predetermined degree of fill. [6] Method according to any one of the preceding claims, characterized by , that at least one functional material is applied to the depressions (16) and to surface sections (23) extending between the depressions (16). [7] Method according to any one of claims 1 to 6, characterized by , that colored particles, fluorescent, luminescent, magnetic and / or metallic material is applied as a functional material. [8] Method according to any one of claims 1 to 7, characterized by that at least one functional material is applied by squeegeeing, printing or foiling. [9] Method according to any one of the preceding claims, characterized by , that the internal security feature (12) is produced in the at least one substrate layer (14) with different shades of gray by adjusting the size, depth, shape, fill level and / or area density of the recesses (16), in particular with the same transmission properties of the transparent and / or translucent layer (21, 22) to be applied. [10] Method according to any one of the preceding claims, characterized by, that the laminate (11) is made from the at least one substrate layer (14) and the at least one transparent or translucent layer (21, 22), wherein the substrate layer (14) has a higher melting point than the at least one transparent or translucent layer (21, 22). [11] Method according to any one of the preceding claims, characterized by , that before the indentations (16) are applied to the substrate layer (14) at least one translucent or opaque substrate layer (14), a grid (25) is applied to the substrate layer (14) using a material which has a higher melting point than the material of the substrate layer (14), and that the grid (25) remains in place when the indentations (16) are applied to the substrate layer (14). [12] Laminate with an internal safety feature (12), - with at least one translucent or opaque substrate layer (14), - with at least one translucent or transparent layer (21, 22) laminated to form a laminate (11), - wherein recesses (16) are provided in at least one substrate layer (14), and at least a subset of the recesses (16) in the at least one substrate layer (14) are filled with the at least one translucent or transparent layer (21, 22) and the filled recesses (16) form the internal security feature (12), characterized by , - that after the indentations (16) have been introduced into the substrate layer (14) and before being combined with at least one further translucent or transparent layer (21, 22), at least a subset of the indentations (16) are provided with at least one functional material. [13] Laminate according to claim 12, characterized by, that the depressions (16) of the substrate layer (14) are partially or completely filled with the at least one functional material and the surface sections between the depressions (16) are at least partially covered with the functional material and / or with at least one transparent or translucent layer (21, 22). [14] Security or valuable document with an internal security feature (12) in which at least one translucent or opaque substrate layer (14) is combined with at least one translucent or transparent layer (21, 22) to form a laminate (11), characterized by , that the laminate (11) is formed according to one of claims 12 to 13.

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