EP2018276B1 - Document of value having security element - Google Patents

Abstract

The invention concerns a value-bearing document (1) which at one of its surfaces has a security element (2) and a transfer film for the production of the value-bearing document. The security element (2) has a magnetic layer (25) for the storage of machine-readable items of information and a reflection layer (23) which is arranged above the magnetic layer (25) in relation to the surface of the value-bearing document. The reflection layer (23) and the magnetic layer (25) cover each other over at least region-wise and the reflection layer (23) is formed by a reflection layer which is not electrically conductive.

Description

The invention relates to a document of value, in particular a credit card, identity card or ticket, which has on one of its surfaces a security element comprising a magnetic layer and a reflective layer. The invention further relates to a transfer film, in particular a hot stamping film, for producing such a value document.

Value documents and stamping foils of the type described above are, for example, made DE 34 22 910 C1 or EP 0 559 069 B1 known. So describes DE 34 22 910 C1 an embossing film, which has a magnetic layer, a metal layer and a protective lacquer layer with a structure having a diffraction-optical effect. EP 0 559 069 B1 describes the construction of a value document with a metal layer and a magnetic layer, wherein between the metal layer and the magnetic layer, a barrier layer is provided, which prevents an action of the magnetizable particles of the magnetic layer on the metal layer.

When using value documents of the type described above, it has now surprisingly been found that sporadic errors occur when reading out information stored in the magnetic layer of the value document. In addition to the occurrence of read errors was occasionally also the failure of the entire reader when making a reading attempt to observe. EP-A-286 738 also shows the state of the art.

The invention is based on the object of minimizing the occurrence of errors in the automatic reading out of information from a magnetic layer of a value document of the type mentioned in the introduction.

This object is achieved by a value document having on its surface a security element, wherein the security element has a magnetic layer for storing machine-readable information and a reflective layer, the reflective layer is arranged with respect to the surface of the document of value above the magnetic layer, the reflective layer and the magnetic layer at least partially overlap, and the reflective layer is a non-electrically conductive reflection layer. This object is further achieved by a transfer foil, in particular a hot stamping foil, for producing such a value document which has a carrier film and a transfer layer separable from the carrier film, which has a magnetic layer for storing machine-readable information and a reflection layer, the reflection layer being between the Carrier film and the magnetic layer is disposed, the reflective layer and the magnetic layer overlap at least partially, and the reflective layer is a non-electrically conductive reflection layer.

The invention is based on the finding that the reading errors occurring in value documents of the type mentioned above are due to an accumulation of electrical charge on the metal layer of the value document, which, in the use of the value document, is transferred by charge transport from the user's body to the metal layer of the document Value document is caused. The charge accumulated by electrostatic charging on the user's body is transferred or capacitively coupled to the metal layer of the value document during the use / contact of the value document when special environmental conditions occur. Characterized in that the reflective layer according to the invention is configured not electrically conductive, On the one hand, the charge accumulated on the body of the user due to electrostatic charging is prevented from being transferred to the reflection layer and accumulated there. Furthermore, this also achieves a potential separation between a region of the reflection layer which is in communication with the human user and the region of the reflection layer of the value document arranged in the immediate vicinity of the reading head.

A non-electrically conductive reflection layer shows the properties of an insulating material and preferably has a resistivity of more than 10 ³ Ω mm ² / m, preferably more than 10 ⁷ Ω mm ² / m, at a temperature of 20 ° C.

The use of such a reflection layer instead of a metallic reflection layer effectively prevents the occurrence of the above-described interference and substantially reduces the occurrence of read errors.

Advantageous embodiments of the invention are designated in the subclaims.

According to a preferred embodiment of the invention, the reflection layer consists of a non-electrically conductive material or of an arrangement of non-electrically conductive materials. The non-electrically conductive reflection layer thus consists for example of a single layer of a non-electrically conductive material, of several successive layers consisting of different, respectively non-electrically conductive materials or of a dispersion of non-electrically conductive particles or pigments in a non-electric conductive binder. Furthermore, it is also possible that the non-electrically conductive reflection layer consists of a dispersion of particles which show a certain electrical conductivity in a dielectric binder, as far as the reflection layer per se due to the mutual isolation of the particles by the non-electrically conductive binder in total not is electrically conductive. It is essential here that a surface area of less than 100 mm ^{2 of} the reflection layer is not electrically conductive, preferably that a surface area of less than 1 mm ^{2 is} not electrically conductive.

The reflection layer preferably consists of one or more dielectric layers which have an optical refractive index which differs from that of the layer arranged above and / or below the reflection layer. In particular, dielectric high-refractive-index layers (HRI = high refraction index) or low refractive index layers (LRI = low refraction index) are used as such dielectric layers. Low-refractive layers are preferably understood to be layers whose optical refractive index is ≦ 1.6. High-index layers are preferably understood to be layers whose optical refractive index is ≥ 2.0.

Here, the use of inorganic dielectric high / low refractive layers has proven particularly useful. As materials for low-refractive layers, preferred are silica (refractive index n = 1.5), magnesia (refractive index n = 1.6), alumina (refractive index n = 1.6), magnesium fluoride (refractive index n = 1.4), calcium fluoride (refractive index n = 1.3 to 1.4), cerium fluoride (refractive index n = 1.6) or aluminum fluoride (refractive index n = 1.3). As materials for high-index layers, zinc sulfide (refractive index n = 2.3), titanium dioxide (refractive index n = 2.4), zirconium dioxide (refractive index n = 2.0), zinc oxide (refractive index n = 2.1), indium oxide (refractive index n = 2.0), ceria (refractive index n = 2.3) or tantalum oxide (refractive index n = 2.1).

In addition to the use of layers of inorganic materials, it is also possible to use in the reflection layer one or more layers consisting of organic materials whose refractive index differs significantly from the refractive index of the surrounding layers. Thus, lacquer layers consisting of an organic polymer, which usually exhibit low-refractive optical properties, can also be used as low-refractive layers.

According to this exemplary embodiment, the reflection layer thus preferably consists of one or more dielectric layers which are applied over the whole area in the region of the reflection layer, for example by vapor deposition (in the case of inorganic dielectric layers) or printing (in the case of organic dielectric layers).

According to a preferred embodiment, the reflection layer consists of an alternating sequence of several high and low refractive index layers. By way of example, the reflection layer consists of an odd-numbered sequence of three or more layers, wherein, starting from a high-index layer, a high-index layer is followed by a low-index layer and a low-index layer by a high-index layer. Such an arrangement of layers makes it possible to considerably increase the proportion of light reflected by the reflection layer. The portions of the incident light reflected at the refractive planes formed in this way add up so that the percentage of light reflected at the reflection layer increases correspondingly with the number of refraction planes.

It has proven to be expedient in this case to select the layer thickness of the high and low refractive index layers in such a layer system such that the optical thickness of the layers for the region of the light visible to the human eye is λ / 4 (λ = wavelength of the light) not fulfilled. In this way it is possible to avoid disturbing interference effects. Furthermore, however, it is also possible to form an interference layer system by appropriate choice of the layer thicknesses of the high and low refractive index layers, which generates an angle-dependent color shift effect by means of interference.

Surprisingly, it has also been found here that the above-described construction of the reflection layer comprising one or more low- and / or high-index layers in combination with a magnetic layer arranged under such a reflection layer exhibits particularly good optical properties: due to the usually dark body color of the under the reflection layer lying magnetic layer, a significant portion of the non-reflected, transmitted through the reflective layer portions of the incident light is absorbed by the magnetic layer, whereby disturbing interference effects are avoided by reflected back from the magnetic layer portions of the transmitted light and a brilliant optical result is achieved. If, for example, diffractive optical surface reliefs are formed in the surface of the reflection layer or in a lacquer layer adjoining the reflection layer, then the optical effect generated thereby, for example a hologram or Kinegram®, is clearly and clearly visible to the human observer even under unfavorable lighting conditions.

According to a further preferred embodiment of the invention, the non-conductive reflection layer consists of a crosslinked liquid crystal layer. In this case, the crosslinked liquid-crystal layer is preferably arranged over the full area in the entire region of the reflection layer. An orientation of the liquid-crystal molecules preferably takes place before the crosslinking of the liquid-crystal layer. The incident light is reflected at the lattice planes of the crosslinked liquid crystals. An interesting visual appearance can be achieved by the use of cholesteric liquid crystals, which due to their spiral character depending on the viewing angle, different reflect / transmit different lengths of light different degrees and thus show a viewing angle-dependent color shift effect. Here too, further surprising advantages result from the combination of such a layer with a magnetic layer arranged below the cholesteric liquid crystal layer. It has been shown that due to the dark body color of the magnetic layer, a large part of the light components transmitted through the liquid crystal layer is absorbed here as well, and the above-described optically variable effect is therefore particularly effective.

According to a further preferred embodiment of the invention, the reflection layer consists of a dispersion of reflective pigments in a dielectric binder. The reflective pigments are in this case preferably constructed from a sequence of high and low refractive index layers, each consisting of a dielectric material. However, it is also possible that these pigments have a metal core, preferably consisting of aluminum, chromium, copper, silver or gold, or an alloy thereof. The use of reflective effect pigments, for example interference-layer pigments, is also possible. According to a further preferred embodiment of the invention, the security element has a security layer, which may have a multilayer structure and is provided above the reflection layer with respect to the surface of the value document. In this case, the reflection layer serves to reinforce the optical effect generated by the security layer, or an optical effect, in particular an optically variable effect, is produced only after the combination of this security layer with the reflection layer. The security layer preferably has a lacquer layer into which a diffraction-optical structure is molded. For example, a hologram, a Kinegram® or a diffraction grating having a spatial frequency of more than 300 lines / mm is molded into the lacquer layer. Furthermore, it is also possible for a macrostructure, for example a refractive microlens grid, a matt structure or an asymmetrical structure, for example a blaze grating, to be molded into the lacquer layer. Furthermore, it is also possible that the security layer has layers which comprise a fluorescent or thermochromic material.

Fig. 1

zeigt eine Draufsicht auf ein erfindungsgemässes Wertdokument.

Fig. 2

zeigt einen Schnitt nach Linie I-I durch das Wertdokument nach Fig. 1.

Fig. 3

zeigt eine schematische Darstellung einer Reflexionsschicht des Wertdokuments nach Fig. 1.

Fig. 4

zeigt eine schematische Darstellung einer Reflexionsschicht des Wertdokuments nach Fig. 1.

Fig. 5

zeigt eine schematische Darstellung einer Reflexionsschicht des Wertdokuments nach Fig. 1.

Fig. 6

zeigt einen abschnittsweisen, schematisierten Schnitt durch eine erfindungsgemässe Transferfolie.

According to a preferred embodiment of the invention, a barrier layer is provided between the magnetic layer and the non-electrically conductive reflection layer. The magnetic layer preferably consists of a dispersion of magnetic particles in a binder, wherein the iron oxides commonly used for magnetic particles have larger proportions of chemically / physically bound water, which can lead to destruction of dielectric, inorganic layers of the reflective layer. In order to prevent this, a barrier layer consisting of hydrophobic inorganic pigments with a large (inner) surface is preferably arranged between the reflection layer and the magnetic layer, which is the diffusion of water in particular by the hydrophobic character the inorganic pigments and effectively prevented by their absorption capacity. The proportion by weight of such pigments in the barrier layer is preferably 10 to 30%. In the following, the invention will be explained by way of example with reference to several embodiments with the aid of the accompanying drawings.

Fig. 1

shows a plan view of an inventive document of value.

Fig. 2

shows a section along line II through the document of value Fig. 1 ,

Fig. 3

shows a schematic representation of a reflection layer of the value document after Fig. 1 ,

Fig. 4

shows a schematic representation of a reflection layer of the value document after Fig. 1 ,

Fig. 5

shows a schematic representation of a reflection layer of the value document after Fig. 1 ,

Fig. 6

shows a sectional, schematic section through a transfer film according to the invention.

Fig. 1 shows the back of a credit card 1. On the back surface, the credit card 1 has a strip-shaped security element 2. The Security feature 2 is arranged on a plastic card-shaped carrier body 3, in which, for example, the name of the cardholder and the credit card number is stamped. The strip-shaped security element 2 can extend over the entire width of the credit card 1 or - as in Fig. 1 indicated - the width of the credit card 1 only partially cover. The strip-shaped security element 2 is in this case formed in the form of a magnetic strip, as it is usually provided in credit cards for storage of machine-readable information. The security element 2 thus has a width of approximately 10 to 12 mm and a length of, for example, 82 mm. Next, the security element 2 is placed on the back of the credit card 1 in the same manner as the magnetic stripe of a conventional credit card so that machine-readable information stored in the security element 2 can be read by the read head of a conventional reader.

In contrast to conventional magnetic strips, the security element 2 has a reflection layer, which gives the security element 2 a special visual appearance. Furthermore, the security element 2 has a plurality of optically variable security features 21 recognizable in reflection, which are preferably diffraction-optical security elements such as holograms, Kinegrame® or a diffraction grating generating a kinetic effect.

In addition to the security element 2, the back of the credit card 1 still has an identifier 4 and possibly other optical security features.

The structure of the security element 2 is now exemplary in FIG Fig. 2 outlined, which shows a section through the credit card 1 along the line II.

Fig. 2 The security element 2 has an adhesive layer 26, a magnetic layer 24 for storing machine-readable information, an adhesion-promoting layer 25, a reflective layer 23 and an optical security layer 22.

The optical security layer 22 consists of a protective lacquer layer and a replication lacquer layer in which a diffraction-optical structure is introduced by means of an embossing punch or by means of UV replication. As already described above, instead of or in addition to a replication lacquer layer having an impressed diffractive optical structure, the security layer 22 may comprise one or more further layers which provide an optically recognizable security feature, preferably in combination with the reflection layer 23. Furthermore, it is also possible for the security layer 22 to have a layer with a repetitive micropattern and an optically transparent layer arranged above this layer, in which a microlens grid is molded. Here, the security layer 22 preferably comprises one or more dielectric layers, the term "dielectric layer" in this context encompassing both organic and inorganic layers with dielectric properties (non-electrically conductive). In this case, it is also possible for the optical security layer 22, in addition to one or more paint layers and / or inorganic layers, also to comprise one or more layers consisting of a plastic film, for example a polyester film.

The magnetic layer 24 consists of a dispersion of magnetic pigments, which is usually iron oxide, in a binder. The magnetic layer in this case preferably has a thickness of 4 to 12 microns. Next is It is also possible that the magnetic layer 24 consists of a sputtered layer of a magnetic material, wherein in this case the magnetic layer can be chosen significantly thinner.

The adhesion-promoting layer 25 has a thickness of 0.2 to 5 μm and preferably consists of an organic lacquer layer. Instead of the adhesion-promoting layer 25, it is also possible to provide a layer system consisting of one or more layers, in particular a layer system comprising a barrier layer, which prevents an influence of the magnetizable particles of the magnetic layer on the reflection layer 23.

The reflection layer 23 is formed by a layer of a high refractive, preferably inorganic dielectric. The layer 23 thus consists, for example, of zinc sulfide, which is vapor-deposited on the layer 22 in a thickness of 10 nm to 500 nm in a vacuum. Furthermore, the layer 23 can also consist of one of the other ceramic materials guided on top, which have a higher refractive index than the layer 22. The layer thickness of the reflection layer 23 is preferably chosen to be smaller than 1 μm in order to avoid the occurrence of microcracks when the security element 2 is applied to the carrier body 3 as much as possible. Preferably, the layer 23 has a thickness of 100 nm to 400 nm.

The security element 2 can in this case be applied to the plastic body 3 as part of the transfer layer of a transfer film. However, it is also possible that one or more of the layers of the security element 2 are applied directly to the plastic body 3, for example by a printing process, and the remaining layers, for example the optical security layer 22 and the reflective layer 23, then as part of a Transfer layer of a transfer film, such as a hot stamping foil, are applied to these layers.

Fig. 3 shows a further possible structure of the reflection layer 23 with reference to a section through the reflection layer according to the in Fig. 1 indicated line II-II. Fig. 3 FIG. 12 shows the reflective layer 23 ', which is made up of a sequence of seven layers, four high-index layers 231 and four low-index layers 232. As in Fig. 3 In the layer structure, high and low refractive index layers change, ie a high refractive index layer is followed by a low refractive index layer and a low refractive index layer is followed by a high refractive index layer. According to a first embodiment, the layer 231 consists of ZnS and the layer 232 of MgF ₂ . According to a further embodiment, the layer 231 consists of TiO ₂ and the layer 232 of SiO ₂ . According to a further embodiment, the layer 231 consists of ZrO ₂ and the layer 232 of SiO ₂ . According to a further embodiment, the layer 231 TiO ₂ and the layer 232 consists of MgF ₂ . According to a further embodiment, the layer 231 consists of ZrO ₂ and the layer 232 of MgF ₂ . According to a further embodiment, the layer 231 consists of ZnS and the layer 232 of MgO. According to a further embodiment, the layer 231 consists of TiO ₂ and the layer 232 of MgO. According to a further embodiment, the layer 231 consists of ZrO ₂ and the layer 232 of MgO.

The layers 231 and 232 are evaporated over the entire surface until the in Fig. 3 achieved layer sequence is reached. The layer 23 'in this case has a layer thickness of preferably less than 1 micron, so that the thickness of the individual layers 231 and 232 is selected accordingly. Instead of a system of seven layers deposited on top of each other, it is also possible provide a larger or smaller, preferably odd number of layers 231 and 232 in the reflective layer 23 '.

In this case, the layer thickness of the individual layers 231 and 232 is preferably selected such that a large part of the incident light is reflected in the region of the visible light and the layers arranged below the reflection layer 23 remain largely hidden in this way.

This can be achieved, in particular, by choosing the effective optical thickness of the layers 231 and 232 to be such that for the visible light range, i. for the wavelength range of 390 to 770 nm, no triggering phenomenon generated by interference comes into play. The effective optical thickness of the layers 231 and 232 is thus preferably less than λ / 2 for the wavelength range of visible light to choose. In order to further avoid additive optically disturbing interference phenomena, the effective optical density of the layers 231 and 232 is preferably to be selected smaller than λ / 4 for the range of the visible light.

Fig. 4 shows a further possible construction, however not included in the claims, of the reflection layer 23 on the basis of a section through the reflection layer according to FIG Fig. 1 indicated line II-II. Fig. 4 FIG. 12 shows the reflection layer 23 "consisting of two layers, an orientation layer 233 and a layer 234 of a liquid crystal material.

The orientation layer 232 preferably consists of a replication lacquer layer into which a relief structure has been molded by means of an embossing tool. The relief structure consists, for example, of a multiplicity of parallel grooves arranged side by side, which make it possible to orient liquid crystal molecules. The spatial frequency of the The relief structure here is preferably 300 to 3000 lines / mm and the profile depth of the grooves is preferably 200 to 600 nm. However, it is also possible for the orientation layer 233 to be formed by an exposed photopolymer layer. In principle, all photopolymers whose orientation properties can be determined by irradiation with polarized light can be used for this purpose. Examples of such photopolymer (LPP = Linearily Photopolymerised Polymers) are, for example, in EP 0 611 786 A . WO 96/10049 and EP 0 763 552 A described. The photopolymer layer is applied to the layer 22 by a wet chemical process, then dried and exposed to polarized UV light.

Furthermore, it is also possible to dispense with the orientation layer 233 or to impress a corresponding surface structure in the layer 22 for orientation of the liquid crystal molecules or to process the layer 22 correspondingly mechanically prior to application of the liquid crystal layer 234, so that a surface structure is formed is suitable for the orientation of the liquid crystal molecules.

The liquid crystal layer 234 is applied to the orientation layer 233, for example by means of a gravure printing process. The liquid crystal layer 234 here preferably consists of a radiation or otherwise curing liquid crystal material. As a liquid crystal material, for example, in US 5,389,698 . US 5 602 661 A . EP 0 689 084 A . EP 0 689 065 A . WO 98/52077 or WO 00/29878 described liquid crystal materials are used. Preferably, for the layer 234, "Merck RMM 129" or "OPALVA®" (Vantico base) is used as the liquid crystal. Subsequently, the liquid crystals are aligned when necessary with the supply of heat. Finally, UV curing takes place or thermally induced radical crosslinking of the liquid crystal material to fix the orientation of the liquid crystal molecules. Furthermore, it is also possible for the layer 234 of a solvent-containing liquid-crystal material to be subjected to a drying process and for the liquid-crystal molecules to orient themselves during the evaporation of the solvent in accordance with the structure introduced into the orientation layer 233.

In addition to the use of nematic liquid crystal material, the use of cholesteric liquid crystal material is also possible, which is applied to the orientation layer in the same way as described above, oriented and then crosslinked. Further, it is also possible, above or below the layer 234, the layer 23 after Fig. 2 or that. Multilayer system 23 'after Fig. 3 provided.

Fig. 5 shows a further possible construction, however not included in the claims, of the reflection layer 23 on the basis of a section through the reflection layer according to FIG Fig. 1 indicated line II-II. Fig. 5 FIG. 12 shows the reflective layer 23 "'consisting of a dispersion of reflective pigments 235 in a dielectric binder 236.

The layer 23 '''preferably has a thickness of 1 .mu.m to 10 .mu.m. As reflective pigments are preferably platelet-shaped pigments having an average diameter of 5 .mu.m to 30 .mu.m use, which consists of several successive dielectric layers, for example according to the multi-layer system according to Fig. 3 are constructed. As reflective pigments and metallic, preferably consisting of aluminum pigments can be used.

The layer 23 '''can be composed as follows: methyl ethyl ketone 260 cyclohexanone 130 Polyvinylchloride Vinyl Acetate Copolymer (Tg = 79 ° C) 110 Polymethylmethacrylate (Tg = 121 ° C) 150 Pigment (eg aluminum pigment) 350

Fig. 6 shows a transfer sheet 6 for the production of the value document after Fig. 1 , The transfer film 6 consists of a carrier film 61, a release layer 63, and a transfer layer 62 having a resist layer 64, a replication resist layer 65, a reflective layer 66, an adhesion promoting layer 67, a barrier layer 68, a magnetic layer 69, and an adhesive layer 70. The carrier film 10 becomes from a plastic film, preferably formed by a polyester film of thickness 12 to 23 microns. On this polyester film, the following layers are preferably applied by means of a gravure roll and optionally dried. In this case, a layer of a wax-like material is preferably applied as the release layer 63. The resist layer 64 and the replica resist layer 65 have a thickness of 0.3 to 1.2 μm. The replication lacquer layer 65 consists of a thermoplastic lacquer in which a diffraction-optical structure 71, for example a hologram or Kinegram®, is embossed by means of a heated rotating embossing cylinder or by stroke embossing.

Subsequently, a layer consisting of SiO _x or ZnS in a thickness of 10 nm to 500 nm is vapor-deposited on the replication lacquer layer 65 as a reflection layer 66.

Subsequently, the adhesion-promoting layer 67, the barrier layer 68, the magnetic layer 69 and the adhesive layer 70 are printed. The metal layer 66 has a thickness of 0.01 to 0.04 μm. The adhesion promoting layer 12 has a thickness of 0.2 to 0.7 μm. The barrier layer 68 has a thickness of 0.5 to 5 μm. The magnetic layer 69 has a thickness of 4 to 12 μm, preferably about 9 μm. The adhesive layer 70 has a thickness of 0.3 to 1.2 μm.

The different layers of the transfer film 6 can be composed as follows:

Replication lacquer layer 65

component Parts by weight high molecular weight PMMA resin 2000 Silicon alkyd, oil-free 300 nonionic wetting agent 50 methyl ethyl ketone 750 low viscosity nitrocellulose 12,000 toluene 2000 diacetone 2500

Reflection layer 66

Vacuum deposited layer of ZnS or SiO _x .

Adhesive layer 67

component parts by weight high molecular weight PVC-PVAc copolymer 1200 methyl ethyl ketone 3400 toluene 1000 matting agent 100

Barrier layer 68

component Parts by weight methyl ethyl ketone 30 toluene 35 ethyl alcohol 15 Vinyl chloride-vinyl acetate copolymer FP:> 65 ° C 11 Unsaturated polyester resin (mp: 100 ° C, d = 1.24 g / cm ³ ) 3 Silicone polyester resin (D = 1.18 g / cm ³ ) 2 Hydrophobic silica (ph ≥ 7 of a 5% slurry in H ₂ O) 4

Magnetic layer 69

This consists of a dispersion of acicular γ-Fe ₂ O ₃ -Magnetpigments in a polyurethane binder, various coating aids and a solvent mixture of methyl ethyl ketone and tetrahydrofuran. However, the magnetic layer does not necessarily have this composition. Instead of the Fe ₂ O ₃ pigments, it is also possible to use, for example, other magnetic pigments, for example Co-doped magnetic iron oxides or other finely dispersed magnetic materials (Sr, Ba ferrites) become. If necessary, the binder combination of the magnetic layer 69 can also be chosen such that the adhesion-promoting layer can be dispensed with, since directly a good adhesion results directly on the metal, which may be important if the barrier layer 68 is omitted.

Adhesive layer 70

The adhesive layer 70 may be a hot-melt adhesive layer known per se. The attachment of this layer is not always necessary. This depends on the composition of the substrate of the value document on which the embossing film is to be embossed. For example, if the substrate is made of PVC, as is usually the case with credit cards, a special hot-melt adhesive layer can usually be dispensed with.

Claims (15)

1. Document of value (1), in particular a credit card, identity card or ticket, which on one of its surfaces has a security element (2),
   the security element (2) having a magnetic layer (25, 69) for storing machine-readable information and a reflective layer (23, 66), the reflective layer being arranged above the magnetic layer (25, 69) in relation to the surface of the document of value, the reflective layer (23, 66) and the magnetic layer (25, 69) overlapping, at least in some regions, and the reflective layer (23, 66) being a reflective layer which is not electrically conductive and which has one or more dielectric high and/or low refractive index layers (231, 232), the one or more dielectric high and/or low refractive index layers (231, 232) each being composed of a dielectric inorganic material, in particular of a ceramic material.
2. Document of value (1) according to Claim 1,
   the reflective layer (23') being composed of an alternating sequence of high and low refractive index layers (231, 232).
3. Document of value (1) according to one of the preceding claims,
   the layer thickness of the high and/or low refractive index layers being chosen in each case in such a way that, in the range of light visible to the human eye, the optical thickness of the respective high or low refractive index layer does not meet the λ/4 condition.
4. Document of value (1) according to one of the preceding claims,
   the one or more dielectric high and/or low refractive index layers forming an interference layer system which generates a colour displacement effect dependent on viewing angle by means of interference.
5. Document of value (1) according to one of the preceding claims,
   the reflective layer (23") having a cross-linked liquid-crystal layer (234).
6. Document of value (1) according to Claim 5,
   the liquid-crystal layer (234) being composed of a cholesteric liquid crystal.
7. Document of value (1) according to Claim 5 or Claim 6,
   an orientation layer (233) for the orientation of the liquid-crystal molecules of the liquid-crystal layer being provided below or above the liquid-crystal layer (234).
8. Document of value (1) according to one of the preceding claims,
   the reflective layer (23''') having a layer composed of a dispersion of reflective pigments (235) in a dielectric binder (236).
9. Document of value (1) according to one of the preceding claims,
   the magnetic layer (25) of the security element (2) being moulded in the form of a strip and the reflective layer (23) overlapping the magnetic layer (25) over its entire surface.
10. Document of value (1) according to one of the preceding claims,
    an optically diffractive structure (21, 71) being moulded in the reflective layer (23, 66).
11. Document of value (1) according to one of the preceding claims,
    a varnish layer (65) being provided in the security element (2) above or below the reflective layer (23, 66), in which varnish layer an optically diffractive structure (21, 71) is moulded.
12. Document of value (1) according to one of the preceding claims,
    the magnetic layer (25, 69) being composed of a dispersion of magnetic particles in a binder.
13. Document of value (1) according to one of the preceding claims,
    the magnetic layer being composed of a dispersion of magnetic particles and colour pigments having a light body colour in a binder.
14. Document of value (1) according to one of the preceding claims,
    a barrier layer (68) being provided between the magnetic layer (69) and the reflective layer (66).
15. Transfer film (6), in particular a hot embossing film, for the production of a document of value according to Claim 1,
    the transfer film (6) having a carrier film (61) and a transfer layer (62) that can be separated from the carrier film (61) and has a magnetic layer (69) for storing machine-readable information and a reflective layer (66), the reflective layer (66) being arranged between the carrier film (61) and the magnetic layer (69) and the reflective layer (66) and the magnetic layer (69) overlapping, at least in some regions, and the reflective layer (66) being a reflective layer which is not electrically conductive and which has one or more dielectric high and/or low refractive index layers (231, 232), the one or more dielectric high and/or low refractive index layers (231, 232) each being composed of a dielectric inorganic material, in particular of a ceramic material.

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