EP4420890A1 - Substrate with electrically conductive layer - Google Patents

Abstract

The invention relates to a substrate (1) for producing securities or security papers, such as banknotes, ID cards, credit cards. It is provided that the substrate has an electrically conductive layer (2) with a machine-readable coding, which electrically conductive layer (2) is transparent in a wavelength range visible to the human eye. The invention also relates to a security paper or security paper.

Description

The invention relates to a substrate for producing securities or security papers, such as banknotes, identity cards, credit cards, as well as a security or security paper.

Substrates, and in particular polymer substrates, as well as securities or security papers of the type mentioned above are usually used to increase the counterfeit security of securities or security papers, such as banknotes, ID cards, credit cards, debit cards, tickets, etc.

Substrates for securities or security papers must meet high quality requirements with regard to their visual appearance. In particular for polymer securities or polymer security papers, it is required that substrates, especially polymer substrates, are transparent, or that at least areas or layers are transparent, so that subsequent printing or design of a security or security paper, especially a polymer security, a polymer security paper or a polymer banknote, is possible at least largely without restrictions. At the same time, it is also required that substrates and the securities or security papers made from them cannot be forged or can only be forged with great difficulty. Until now, a compromise had to be found between these two requirements - good visual designability and at the same time a high level of forgery security.

The object of the present invention is to create a substrate with increased security against counterfeiting, which at the same time also increases the creative freedom and can be designed in a variety of ways.

This object is achieved according to the invention by a substrate of the type mentioned at the outset in that it has an electrically conductive layer with a machine-readable coding, which electrically conductive layer is transparent in a wavelength range visible to the human eye. The coding is an electrically readable, machine-readable coding.

Materials for the production of transparent electrically conductive layers are known to the experts, for example, through the DE60024062T2 became known.

Various technologies are known to experts for reading electrically readable, machine-readable security features. WO2018141478A1 and the WO2018141477A1 each disclose a method for generating a time-dependent signal on a capacitive area sensor. Further technologies for detecting capacitive signals are described in the WO2018119525A1 and through the DE102012023082A1 known. At this point it should be made clear that the electrically conductive layer with a machine-readable code according to the invention is an electrically readable code. This is in contrast to conventional machine-readable codes, which are usually magnetic codes.

The inventive design of the substrate with the electrically conductive layer has the advantage that it is extremely forgery-proof. Even if a forger recognizes that the security element contains an electrically readable, machine-readable code, it is still impossible for him to imitate or even copy it. In addition, the electrically conductive layer does not affect the optical appearance of the substrate, so that it can be designed in an unlimited variety of ways according to methods known from the state of the art.

The transparency of the electrically conductive layer according to the invention is particularly advantageous when a banknote with a so-called window is manufactured from the substrate or preferably polymer substrate. For an observer, the window appears extremely attractive and high-quality due to its transparency, while at the same time a counterfeiter cannot recognize that the window contains an electrically readable, machine-readable code.

The substrate can, in particular if it is a polymer substrate, be made of a translucent and/or thermoplastic material. The substrate or polymer substrate can preferably be made of at least one of the materials from the group polyimide (PI), polypropylene (PP), monoaxially oriented polypropylene (MOPP), biaxially oriented polypropylene (BOPP), polyethylene (PE), polyphenylene sulfide (PPS), polyetheretherketone (PEEK), polyetherketone (PEK), polyethyleneimide (PEI), polysulfone (PSU), polyaryletherketone (PAEK), polyethylene naphthalate (PEN), liquid crystalline polymers (LCP), polyester, Polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyamide (PA), polycarbonate (PC), cycloolefin copolymers (COC), polyoxymethylene (POM), acrylonitrile butadiene styrene (ABS), polyvinyl chloride (PVC), ethylene tetrafluoroethylene (ETFE), polytetrafluoroethylene (PTFE), polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), ethylene tetrafluoroethylene hexafluoropropylene fluoro terpolymer (EFEP), cellulose or lignin-based plastics, polyhydroxyalkanoates (PHA), thermoplastic starch (TPS), polylactic acid (PLA), polycaprolactone (PCL), polybutylene succinate (PBS), and polybutylene adipate terephthalate (PBAT) and/or at least one recycled and/or biodegradable and/or marine degradable plastic and/or mixtures and/or copolymers of these materials or be made of at least one of these materials.

Furthermore, it may be expedient if the electrically conductive layer has a transmittance of 0 to 0.5, preferably from 0 to 0.3, particularly preferably from 0 to 0.1.

The transmittance is a measure of the transmitted intensity and is defined as the quotient between the intensity in front of an obstacle and the intensity behind this obstacle. The transmittance therefore takes on values between 0 and 1.

It is common practice in the industry, particularly in the production of polymer banknotes, to use the material parameters "haze" and "clarity" to describe transparency instead of a transmission level. Common standards for determining these material properties are ISO 13468 (determination of the total light transmittance of transparent materials), ISO 14782 (determination of the haze value of transparent materials) and ASTM D1003 (testing the haze and light transmittance of transparent plastics).

Furthermore, it can be provided that the electrically conductive layer is applied to one side of the substrate, or that the electrically conductive layer is introduced into the substrate. It is also conceivable that the electrically conductive layer is applied to both sides of the substrate.

An electrically conductive layer introduced into the substrate can be particularly useful if the substrate is a hybrid product consisting of a polymeric substrate and a cellulose-containing substrate, i.e. a paper substrate.

Also advantageous is an embodiment according to which it can be provided that the electrically conductive layer is designed as a security element or as part of a security element, wherein the security element is applied to the substrate, or wherein the security element is introduced into the substrate.

At this point, it should be noted that in the context of the invention, the term security element can refer to various types of security elements familiar to those skilled in the art. For example, security elements can be designed as security threads, security strips, security patches and the like. Of course, other types of security elements known to those skilled in the art are also conceivable.

As is known per se, the security element can be designed with one or more security features. For example, the security element can have an optical effect layer. The optical effect layer can be applied directly to the electrically conductive layer or can be applied to the electrically conductive layer with one or more intermediate layers. Each additional layer described in this document can in principle also be formed from several layers or plies.

Each of the layers described can be applied in particular using a gravure printing process. In addition to printing processes, it would also be conceivable for the top layer to be applied by painting, dip coating, spray coating or roller coating. It is also conceivable to apply the top layer using vacuum-based coating processes, such as plasma coating or PVD and CVD coating.

According to a particular embodiment, it is possible for the security element to comprise a printed electrically non-conductive metal layer or a printed electrically non-conductive metal pigment layer.

The security element can comprise a metallic effect paint and/or a metallic effect varnish and/or a metallic effect ink and/or a metallic material, in particular selected from the group consisting of silver, copper, aluminium, gold, platinum, niobium, tin, or nickel, titanium, vanadium, chromium, cobalt and palladium or alloys of these materials, in particular cobalt-nickel alloys.

According to an advantageous development, it can be provided that the security element has a layer with a color-shift effect and contains a color-shifting thin-film element or color-shifting pigments, in particular interference pigments, or liquid crystal pigments.

On a side facing away from the visible side of the security element, there can be at least one layer that enhances the color-shift effect, wherein the layer that enhances the color-shift effect is in particular a layer of dark color and/or a layer of metal oxides, such as substoichiometric aluminum oxide. For example, the layer that enhances the color-shift effect can be applied to a liquid crystal layer or a layer of color-shifting pigments, so that the layer of color-shifting pigments or the liquid crystal layer is arranged between the layer that enhances the color-shift effect and the carrier layer. However, the layer that enhances the color-shift effect can also be arranged between the carrier layer and the layer of color-shifting pigments or the at least one liquid crystal layer. In addition, it is also possible for a carrier layer to be arranged between the layer that enhances the color-shift effect and the layer of color-shifting pigments or the liquid crystal layer.

The security element may have at least one liquid crystal layer, in particular a cholesteric liquid crystal layer.

The security element may also comprise an optically non-linear layer or an optically non-linear layer and/or as a layer containing fluorescent pigments and/or fluorescent substances.

Optically non-linear layers or layers or materials that form these layers are also referred to as IR upconverters or UV downconverters. These can be materials that exhibit a visible color under the influence of electromagnetic radiation outside the visible wavelength range of light. Such materials can be excited to emit visible light under these conditions, for example when exposed to infrared (IR) (λ > 780 nm) and/or ultraviolet (UV) light (λ < 380 nm).

The security element can comprise structures or be formed with structures. In particular, the structures can be achromatic and/or reflective structures, such as for example micromirrors, and/or refractive structures, such as microlenses, and/or diffractive structures, such as holograms.

The structures can be introduced directly into a carrier layer or into a further layer, in particular an embossing lacquer layer, in particular embossed by means of a molding device.

The structure or structures can be embossed directly into a carrier layer. For example, by heating the carrier layer and embossing the structures using an embossing tool, such as an embossing roller.

Another alternative option would be to provide a separate additional layer to accommodate the structures. The additional layer can be applied directly to a carrier layer. For example, the additional layer can be formed from an embossing lacquer that is shaped to match the arrangement of the structures. This can in turn be done using a molding device or a molding element in an embossing process.

The arrangement or application of an optical effect layer or its layers onto the structures or the metal layers and/or metal effect layers can be carried out, for example, by a printing process and/or a vapor deposition process or several of these. However, the materials or additives of the reflective layer described below could also form a component or a layer of the optical effect layer. These can in particular be printed or vapor deposited and thus form a separate layer of the optical effect layer.

In particular, it can be advantageous if the security element is formed with a thin-film element and has at least one absorber layer and at least one spacer layer.

The at least one absorber layer can comprise at least one metallic material, in particular selected from the group of nickel, titanium, vanadium, chromium, cobalt, palladium, iron, tungsten, molybdenum, niobium, aluminum, silver, copper and/or alloys of these materials, or can be made from at least one of these materials.

Furthermore, it can be provided that a thin-film element further comprises at least one reflection layer and/or a second absorber layer, wherein the at least one

A spacer layer is arranged between the at least one first absorber layer and the at least one reflection layer and/or the at least one second absorber layer.

The reflection layer can be applied or arranged on structures and can in particular be printed and/or vapor-deposited on them. It is also possible to reverse this order in the optical effect layer so that the absorber layer is arranged on the structures and then the spacer layer and the reflection layer. The arrangement would therefore be in the order structures - absorber layer - spacer layer - reflection layer. Instead of the above-mentioned reflection layer, however, another absorber layer can also be provided.

The at least one reflection layer can comprise at least one metallic material, in particular selected from the group consisting of silver, copper, aluminum, gold, platinum, niobium, tin, or nickel, titanium, vanadium, chromium, cobalt and palladium or alloys of these materials, in particular cobalt-nickel alloys or at least one high-index dielectric material with a refractive index of greater than 1.65, in particular selected from the group consisting of zinc sulfide (ZnS), zinc oxide (ZnO), titanium dioxide (TiO ₂ ), carbon (C), indium oxide (In ₂ O ₃ ), indium tin oxide (ITO), tantalum pentoxide (Ta ₂ O ₅ ), cerium oxide (CeO ₂ ), yttrium oxide (Y ₂ O ₃ ), europium oxide (Eu ₂ O ₃ ), iron oxides such as iron(II,III) oxide (Fe ₃ O ₄ ) and iron(III) oxide (Fe ₂ O ₃ ), Hafnium nitride (HfN), hafnium carbide (HfC), hafnium oxide (HfO ₂ ), lanthanum oxide (La ₂ O ₃ ), magnesium oxide (MgO), neodymium oxide (Nd ₂ O ₃ ), praseodymium oxide (Pr ₆ O ₁₁ ), samarium oxide (Sm ₂ O ₃ ), antimony trioxide (Sb ₂ O ₃ ), silicon carbide (SiC), silicon nitride (Si ₃ N ₄ ), silicon monoxide (SiO), selenium trioxide (Se ₂ O ₃ ), tin oxide (SnO ₂ ), tungsten trioxide (WO ₃ ), high-index organic monomers and/or high-index organic polymers or be made from at least one of these materials.

The at least one spacer layer can be a low-refractive dielectric material with a refractive index of less than or equal to 1.65, in particular selected from the group aluminum oxide (Al ₂ O ₃ ), metal fluorides, for example magnesium fluoride (MgF ₂ ), aluminum fluoride (AlF ₃ ), cerium fluoride (CeF ₃ ), sodium aluminum fluorides (eg Na ₃ AlF ₆ or Na ₅ Al ₃ F ₁₄ ), silicon oxide (SIO _x ), silicon dioxide (SiO ₂ ), neodymium fluoride (NdF ₃ ), lanthanum fluoride (LaF ₃ ), samarium fluoride (SmF ₃ ), barium fluoride (BaF _{2 ), calcium fluoride (CaF 2 )} , lithium fluoride (LiF), low-refractive organic monomers and/or low-refractive organic polymers or at least one high-refractive dielectric material with a refractive index greater than 1.65, in particular selected from the group zinc sulfide (ZnS), zinc oxide (ZnO), titanium dioxide (TiO ₂ ), carbon (C), indium oxide (In ₂ O ₃ ), indium tin oxide (ITO), tantalum pentoxide (Ta ₂ O ₅ ), cerium oxide (CeO ₂ ), yttrium oxide (Y ₂ O ₃ ), europium oxide (Eu ₂ O ₃ ), iron oxides such as iron (II,III) oxide (Fe ₃ O ₄ ) and iron (III) oxide (Fe ₂ O ₃ ), hafnium nitride (HfN), hafnium carbide (HfC), hafnium oxide (HfO ₂ ), lanthanum oxide (La ₂ O ₃ ), magnesium oxide (MgO), neodymium oxide (Nd ₂ O ₃ ), praseodymium oxide (Pr ₆ O ₁₁ ), Samarium oxide (Sm ₂ O ₃ ), antimony trioxide (Sb ₂ O ₃ ), silicon carbide (SiC), silicon nitride (Si ₃ N ₄ ), silicon monoxide (SiO), selenium trioxide (Se ₂ O ₃ ), tin oxide (SnO ₂ ), tungsten trioxide (WO ₃ ), high-refractive organic monomers and/or high-refractive organic polymers or be made from at least one of these materials.

Furthermore, it can be provided that the security element is a partial layer or comprises a partial layer, wherein the partial layer represents a portrait, a landscape, an abstract geometric symbol, logo or an alphanumeric symbol and/or an icon and/or a code and/or a sequence of characters.

The security element can comprise a carrier layer made of a plastic, wherein in particular the plastic can be formed from a translucent and/or thermoplastic plastic. The carrier layer can preferably contain at least one of the materials from the group polyimide (PI), polypropylene (PP), monoaxially oriented polypropylene (MOPP), biaxially oriented polypropylene (BOPP), polyethylene (PE), polyphenylene sulfide (PPS), polyether ether ketone (PEEK), polyether ketone (PEK), polyethylene imide (PEI), polysulfone (PSU), polyarylether ketone (PAEK), polyethylene naphthalate (PEN), liquid crystalline polymers (LCP), polyester, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyamide (PA), polycarbonate (PC), cycloolefin copolymers (COC), polyoxymethylene (POM), acrylonitrile butadiene styrene (ABS), polyvinyl chloride (PVC), ethylene tetrafluoroethylene (ETFE), polytetrafluoroethylene (PTFE), polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), ethylene tetrafluoroethylene hexafluoropropylene fluoro terpolymer (EFEP), cellulose or lignin-based plastics, polyhydroxyalkanoates (PHA), thermoplastic starch (TPS), polylactic acid (PLA), polycaprolactone (PCL), polybutylene succinate (PBS), and polybutylene adipate terephthalate (PBAT) and/or at least one recycled and/or biodegradable and/or marine degradable plastic and/or mixtures and/or co-polymers of these materials or be made from at least one of these materials.

As is known per se, the security element can have additional layers, which additional layers include in particular protective varnishes, heat-sealing varnishes, adhesives, primers and/or films. Protective varnishes can protect the entire layer and/or layer structure from mechanical damage such as scratches, grooves or the like. A protective layer can be provided on one or both sides. Preferably, a flat design of the security element can also be achieved by means of a protective layer.

According to a further development, it is possible that the electrically conductive layer is a printed layer.

In this case, application using a gravure printing process is particularly advantageous. In addition to printing processes, it would also be conceivable for the electrically conductive layer to be applied by painting, dip coating, spray coating or roller coating. It is also conceivable to apply the electrically conductive layer using vacuum-based coating processes, such as plasma coating or PVD and CVD coating.

Furthermore, it may be expedient if the electrically conductive layer comprises a non-metallic conductive material.

Of course, it would also be conceivable and possibly advantageous if the electrically conductive layer comprises a metal layer or a layer containing metal particles.

Furthermore, it can be provided that the non-metallic conductive material contained in the electrically conductive layer comprises an electrically conductive polymer.

When it comes to electrically conductive polymers, a distinction is generally made between intrinsically and extrinsically conductive polymers. Intrinsically conductive polymers are plastics with an electrical conductivity that is comparable to metals. The conductivity of the polymer is achieved through conjugated double bonds, which allow charge carriers to move freely in the doped state. Polymers that are only conductive due to electrically conductive fillers such as aluminum flakes or carbon black are called extrinsically conductive polymers.

Electrically conductive polymers can be selected from a group comprising inorganic polymers, organometallic polymers, fully or partially aromatic polymers, homopolymers, copolymers, Biopolymers, chemically modified polymers and/or synthetic polymers can be selected. Particularly preferred are polymers selected based on polyparaphenylene, polyparaphenylvinylene, polyacetylene, polypyrrole, polythiophene, polyaniline (PANI) and poly-3,4-ethylenedioxythiophene (PEDOT), each with the various known side chain modifications. PEDOT can preferably be included in a poly(styrenesulfonic acid) system (PSS system), i.e. form a PEDOT-PSS. Polymers can also be designed as nanowires.

Furthermore, it can be provided that the non-metallic conductive material contained in the electrically conductive layer comprises an electrically conductive graphite-containing varnish.

Electrically conductive graphite-containing paints are also known as carbon-conductive paints. Such graphite-containing paints preferably contain electrically conductive particles, in particular soot or graphite particles, graphene, carbon nanowires or carbon nanotubes (CNT).

The electrically conductive layer can advantageously also be formed from combinations of the aforementioned metallic and non-metallic materials.

According to an advantageous development, it can be provided that the electrically conductive layer covers the substrate completely or partially.

If the transparent electrically conductive layer is formed in a security element, the electrically conductive layer may completely or partially cover the security element.

Also advantageous is a development in which, in addition to the electrically conductive layer, a further electrically conductive layer is formed, which further electrically conductive layer is transparent in a wavelength range visible to the human eye. In particular, the further electrically conductive layer can be formed in a different layer plane than the electrically conductive layer.

The further electrically conductive layer preferably comprises a different material or materials than the electrically conductive layer. The substrate can be completely or partially covered with the two different electrically conductive layers. The two electrically conductive layers can be directly next to each other, on top of each other, i.e. overlapping or overlapping in regions, or arranged separately from one another. In particular, the electrically conductive layer may be formed or arranged in more than one layer level, so that when the coding is read out, the signal or information comes from different layer levels.

According to a preferred development, it can be provided that the substrate is a polymer substrate.

The object of the invention mentioned at the outset is also achieved independently by a polymer security paper or polymer security paper in that it comprises a substrate according to one of the claims.

According to an advantageous further development, it can be provided that the security or safety paper is a polymer security or polymer safety paper.

In order to avoid unnecessary repetition, reference is made here to the previously mentioned training courses and their advantages.

For a better understanding of the invention, it is explained in more detail with reference to the following figures.

Fig. 1

einen beispielhaften Schichtaufbau eines Substrats,

Fig. 2

eine Draufsicht auf das in Fig. 1 gezeigte Substrat,

Fig. 3

einen weiteren beispielhaften Schichtaufbau eines Substrats,

Fig. 4

eine Draufsicht auf das in Fig. 3 gezeigte Substrat,

Fig. 5

einen weiteren beispielhaften Schichtaufbau eines Substrats,

Fig. 6

eine Draufsicht auf das in Fig. 5 gezeigte Substrat,

Fig. 7

einen weiteren beispielhaften Schichtaufbau eines Substrats,

Fig. 8

eine Draufsicht auf das in Fig. 7 gezeigte Substrat,

Fig. 9

einen weiteren beispielhaften Schichtaufbau eines Substrats.

They show in a highly simplified, schematic representation:

Fig.1

an exemplary layer structure of a substrate,

Fig.2

a view of the Fig.1 shown substrate,

Fig.3

another example of a substrate layer structure,

Fig.4

a view of the Fig.3 shown substrate,

Fig.5

another example of a substrate layer structure,

Fig.6

a view of the Fig.5 shown substrate,

Fig.7

another example of a substrate layer structure,

Fig.8

a view of the Fig.7 shown substrate,

Fig.9

another example layer structure of a substrate.

To begin with, it should be noted that in the different embodiments described, identical parts are provided with identical reference symbols or identical component designations, whereby the disclosures contained in the entire description can be transferred analogously to identical parts with identical reference symbols or identical component designations. The position information chosen in the description, such as top, bottom, side, etc., also refers to the figure directly described and shown, and these position information must be transferred analogously to the new position if the position changes.

As an introduction, it should also be mentioned that the layer structure and the arrangement of further layers depend on the type of attachment of the security element to a security object, since the side of the security element to be viewed after attachment is crucial. The visible side can therefore be viewed from above, as shown in the figures, but it is also possible to view the security element from a visible side from below, e.g. through a carrier.

At this point, it should also be noted that the phrase "a layer is applied to something" is to be understood as meaning that the layer can be applied directly, or that one or more intermediate layers can be located between the applied layer and that onto which the layer is applied. At this point, it should also be noted that one or more intermediate layers can be arranged between the layers described in this document. It is therefore not absolutely necessary for the layers described to contact one another. It should also be noted that the term layer in this document is to be understood as meaning that a layer can also be made up of several sub-layers.

In the present context, "covered", "covered" or "covered over" means that the electrically conductive layer can be arranged either above or below or in front of or behind any covering layer when viewed from one and the same side.

The Figures 1 to 9 The layer structures shown, as well as top views, are, as is clear to the person skilled in the art, only roughly schematically sketched and are to be understood as sections or area views of an overall product. For the sake of simplicity, the The plan views of the substrates shown are each shown in the form of a fully cut security or a fully cut individual banknote. The person skilled in the art will of course know that substrates are usually available on rolls or, after packaging or cutting, in sheet form, with several individual banknotes subsequently being cut from such a sheet. As already explained above, the substrate described, in particular a polymer substrate, can be further processed into a security or security paper, in particular into a polymer security or polymer security paper. Such a security or security paper thus comprises the electrically conductive layer 2 or its machine-readable coding, which is transparent in a wavelength range visible to the human eye.

In the Fig.1 A possible layer structure of a substrate 1 is shown as an example. The substrate 1 is preferably a polymer substrate. The Fig.2 shows a top view of this substrate 1. It is provided that an electrically conductive layer 2 with a machine-readable coding is applied directly to the substrate 1, for example to a polymer banknote substrate. It is provided that the electrically conductive layer 2 or its machine-readable coding is transparent in a wavelength range visible to the human eye. The transparent electrically conductive layer 2 can have a transmittance of 0 to 0.5, preferably from 0 to 0.3, particularly preferably from 0 to 0.1.

The electrically conductive layer 2 is applied to the substrate 1 via a transparent or translucent primer 6, for example - when looking at the layer structure or the substrate 1 from a visible side 5. On top of this, another identical or differently constructed layer of a primer 6 is provided, which is also transparent or translucent, and which can in particular be printed on. The electrically conductive layer 2 is transparent in a wavelength range visible to the human eye. In the plan view of this substrate 1 according to Fig.2 it is shown that the electrically conductive layer 2 covers the substrate 1, or a security document made therefrom, over its entire surface or completely.

The substrate 1 or a layer of the substrate 1 can, in particular if it is a polymer substrate, be made of a translucent and/or thermoplastic material. The substrate 1 or polymer substrate can preferably contain at least one of the materials from the group polyimide (PI), polypropylene (PP), monoaxially oriented polypropylene (MOPP), biaxially oriented polypropylene (BOPP), polyethylene (PE), polyphenylene sulfide (PPS), polyether ether ketone (PEEK), polyether ketone (PEK), polyethylene imide (PEI), polysulfone (PSU), polyarylether ketone (PAEK), polyethylene naphthalate (PEN), liquid crystalline polymers (LCP), polyester, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyamide (PA), polycarbonate (PC), cycloolefin copolymers (COC), polyoxymethylene (POM), acrylonitrile butadiene styrene (ABS), polyvinyl chloride (PVC), ethylene tetrafluoroethylene (ETFE), polytetrafluoroethylene (PTFE), polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), ethylene tetrafluoroethylene hexafluoropropylene fluoro terpolymer (EFEP), cellulose or Lignin-based plastics, polyhydroxyalkanoates (PHA), thermoplastic starch (TPS), polylactic acid (PLA), polycaprolactone (PCL), polybutylene succinate (PBS), and polybutylene adipate terephthalate (PBAT) and/or at least one recycled and/or biodegradable and/or marine degradable plastic and/or mixtures and/or copolymers of these materials or be made from at least one of these materials.

The electrically conductive layer 2 can, as in the Fig. 1 and Fig. 2 shown, applied to one side of the substrate 1. Alternatively, it would also be conceivable if the electrically conductive layer 2 is introduced into the substrate 1. Alternatively, it would also be conceivable if the electrically conductive layer 2 is applied to both sides of the substrate 1. This is the case, for example, if the substrate 1 is a hybrid product made of a polymeric substrate and a cellulose-containing substrate, i.e. a paper substrate.

The electrically conductive layer 2 shown can be a printed layer, which was preferably applied in a gravure printing process.

The electrically conductive layer 2 can comprise a non-metallic conductive material. Of course, it would also be conceivable and possibly advantageous if the electrically conductive layer 2 comprises a metal layer or a layer containing metal particles. The non-metallic conductive material contained in the electrically conductive layer 2 can alternatively or additionally also comprise an electrically conductive polymer.

Electrically conductive polymers can be selected from a group comprising inorganic polymers, organometallic polymers, fully or partially aromatic polymers, homopolymers, copolymers, biopolymers, chemically modified polymers and/or synthetic polymers. Particularly preferred are polymers selected based on polyparaphenylene, Polyparaphenylvinylene, polyacetylene, polypyrrole, polythiophene, polyaniline (PANI) and poly-3,4-ethylenedioxythiophene (PEDOT), each with the various known side chain modifications. PEDOT can preferably be included in a poly(styrenesulfonic acid) system (PSS system), thus forming a PEDOT-PSS. Polymers can also be formed as nanowires, for example.

Any non-metallic conductive material contained in the electrically conductive layer 2 may comprise an electrically conductive graphite-containing varnish.

The electrically conductive layer 2 can advantageously also be formed from combinations of the aforementioned metallic and non-metallic materials.

In the Fig.3 Another possible layer structure of a substrate 1 is shown as an example. Fig.4 shows a top view of this substrate 1. It is provided that an electrically conductive layer 2 with a machine-readable coding is applied directly to the substrate 1, for example a polymer banknote substrate. It is also provided that the electrically conductive layer 2 or its machine-readable coding is transparent in a wavelength range visible to the human eye. The transparent electrically conductive layer 2 can have a transmittance of 0 to 0.5, preferably from 0 to 0.3, particularly preferably from 0 to 0.1.

A further electrically conductive layer 4 is provided immediately or directly next to this electrically conductive layer 2. The further electrically conductive layer 4 is also transparent in a wavelength range visible to the human eye. It would also be conceivable for the two areas with electrically conductive layers 2, 4 to be separated from one another or spaced apart from one another when the substrate 1 is viewed from above or from the visible side 5. The structure of the two areas with electrically conductive layers 2, 4 can be identical, as shown. Of course, the two areas can also be constructed with various other layers. This is within the skill and discretion of the average person skilled in the art.

In particular with regard to possible non-conductive materials, reference is made to the previously mentioned parts of the description. The further electrically conductive layer 4 preferably comprises a different material or materials than the electrically conductive layer 2. The substrate 1 can be provided with the two different electrically conductive layers 2, 4 be completely or partially covered. The two electrically conductive layers 2, 4 can be arranged directly next to each other, one above the other, i.e. overlapping or partially overlapping, or separately from each other.

In Fig.9 A further embodiment is shown, whereby the description of the Fig.3 and 4 In this layer structure shown, representative of a large number of possible designs, one electrically conductive layer 2 is partially formed and the other electrically conductive layer 4 is formed over the entire surface.

Not shown figuratively, but equally conceivable would be a variant according to which the electrically conductive layer 2, 4 is formed or arranged in more than one layer plane.

In the Fig.5 shows another possible layer structure of a substrate 1 by way of example. As already described, the electrically conductive layer 2 can be designed as a security element 3 or as part of a security element 3, wherein the security element 3 is applied to the substrate 1, or wherein the security element 3 is introduced into the substrate 1. According to the example in the Fig.5 it is provided that the electrically conductive layer 2 is formed with a machine-readable coding on a security element 3, for example a security strip, security patch or security thread, which security element 3 is applied to the substrate 1. It is also provided that the electrically conductive layer 2 or its machine-readable coding is transparent in a wavelength range visible to the human eye. The transparent electrically conductive layer 2 can have a transmittance of 0 to 0.5, preferably from 0 to 0.3, particularly preferably from 0 to 0.1.

In the Fig.5 the security element 3 is shown before it is attached to the substrate 1, i.e. still separately. The security element 3 can be formed with a carrier layer 7 designed as a transfer layer or transfer film. This carrier layer 7 can be removed after application to the surface of the substrate 1, as is known per se. Variants are of course also conceivable in which the carrier layer 7 remains on the security element 3 after application.

As is known per se, the security element can have additional layers, which additional layers include in particular protective varnishes, heat-sealing varnishes, adhesives, primers and/or films. Protective varnishes can protect the entire layer and/or layer structure from mechanical damage such as scratches, grooves or the like. A protective layer can be provided on one or both sides. Preferably, a protective layer can also be used to achieve a flat design of the security element. In the example shown, the security element 3 - described from a visible side 5 from top to bottom - is formed with a carrier layer 7, a primer 6, the electrically conductive layer 2, another identical or different primer 6 and a heat-sealing lacquer 8.

The carrier layer 7 can be made of a translucent and/or thermoplastic material. The carrier layer 7 can preferably contain at least one of the materials from the group polyimide (PI), polypropylene (PP), monoaxially oriented polypropylene (MOPP), biaxially oriented polypropylene (BOPP), polyethylene (PE), polyphenylene sulfide (PPS), polyether ether ketone (PEEK), polyether ketone (PEK), polyethylene imide (PEI), polysulfone (PSU), polyarylether ketone (PAEK), polyethylene naphthalate (PEN), liquid crystalline polymers (LCP), polyester, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyamide (PA), polycarbonate (PC), cycloolefin copolymers (COC), polyoxymethylene (POM), acrylonitrile butadiene styrene (ABS), polyvinyl chloride (PVC), ethylene tetrafluoroethylene (ETFE), polytetrafluoroethylene (PTFE), polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), Ethylene-tetrafluoroethylene-hexafluoropropylene fluoroterpolymer (EFEP), cellulose- or lignin-based plastics, polyhydroxyalkanoates (PHA), thermoplastic starch (TPS), polylactic acid (PLA), polycaprolactone (PCL), polybutylene succinate (PBS), and polybutylene adipate terephthalate (PBAT) and/or at least one recycled and/or biodegradable and/or marine degradable plastic and/or mixtures and/or copolymers of these materials or be made from at least one of these materials.

As is known per se, the security element 3 can be designed with one or more additional security features. For example, the security element 3 can have an optical effect layer. The optical effect layer can be applied directly to the electrically conductive layer or can be applied to the electrically conductive layer 2 with one or more intermediate layers. Each additional layer described in this document can in principle also be formed from several layers or plies.

Each of the layers described can be applied in particular using a gravure printing process. In addition to printing processes, it would also be conceivable for the top layer to be applied by painting, dip coating, spray coating or roller coating. It is also conceivable to apply the top layer using vacuum-based coating processes, such as plasma coating or PVD and CVD coating.

The security element 3 may comprise a printed electrically non-conductive metal layer or a printed electrically non-conductive metal pigment layer.

The security element 3 can comprise a metallic effect paint and/or a metallic effect varnish and/or a metallic effect ink and/or a metallic material, in particular selected from the group consisting of silver, copper, aluminium, gold, platinum, niobium, tin, or nickel, titanium, vanadium, chromium, cobalt and palladium or alloys of these materials, in particular cobalt-nickel alloys.

The security element 3 can have a layer with a color-shift effect and contain a color-shifting thin-film element or color-shifting pigments, in particular interference pigments or liquid crystal pigments.

On a side facing away from the visible side of the security element 3, there can be at least one layer that enhances the color-shift effect, wherein the layer that enhances the color-shift effect is in particular a layer of dark color and/or a layer of metal oxides, such as substoichiometric aluminum oxide. For example, the layer that enhances the color-shift effect can be applied to a liquid crystal layer or a layer of color-shifting pigments, so that the layer of color-shifting pigments or the liquid crystal layer is arranged between the layer that enhances the color-shift effect and the carrier layer. However, the layer that enhances the color-shift effect can also be arranged between the carrier layer and the layer of color-shifting pigments or the at least one liquid crystal layer. In addition, it is also possible for a carrier layer to be arranged between the layer that enhances the color-shift effect and the layer of color-shifting pigments or the liquid crystal layer.

The security element 3 can have at least one liquid crystal layer, in particular a cholesteric liquid crystal layer.

The security element 3 can also have an optically non-linear layer or an optically non-linear layer and/or as a layer containing fluorescent pigments and/or fluorescent substances.

The security element 3 can comprise structures or be formed with structures. In particular, the structures can comprise achromatic and/or reflective structures, such as micromirrors, and/or refractive structures, such as microlenses, and/or diffractive structures, such as holograms.

The security element 3 can be formed with or as a thin-film element and have at least one absorber layer and at least one spacer layer. The at least one absorber layer can comprise at least one metallic material, in particular selected from the group of nickel, titanium, vanadium, chromium, cobalt, palladium, iron, tungsten, molybdenum, niobium, aluminum, silver, copper and/or alloys of these materials, or can be made from at least one of these materials.

Furthermore, it can be provided that a thin-film element further comprises at least one reflection layer and/or a second absorber layer, wherein the at least one spacer layer is arranged between the at least one first absorber layer and the at least one reflection layer and/or the at least one second absorber layer.

The reflection layer can be applied or arranged on structures and can in particular be printed and/or vapor-deposited on them. It is also possible to reverse this order in the optical effect layer so that the absorber layer is arranged on the structures and also the spacer layer and the reflection layer. The arrangement would therefore be in the order structures - absorber layer - spacer layer - reflection layer. Instead of the above-mentioned reflection layer, however, another absorber layer can also be provided.

The at least one reflection layer can comprise at least one metallic material, in particular selected from the group consisting of silver, copper, aluminum, gold, platinum, niobium, tin, or nickel, titanium, vanadium, chromium, cobalt and palladium or alloys of these materials, in particular cobalt-nickel alloys or at least one high-index dielectric material with a refractive index of greater than 1.65, in particular selected from the group consisting of zinc sulfide (ZnS), zinc oxide (ZnO), titanium dioxide (TiO ₂ ), carbon (C), indium oxide (In ₂ O ₃ ), indium tin oxide (ITO), tantalum pentoxide (Ta ₂ O ₅ ), cerium oxide (CeO ₂ ), yttrium oxide (Y ₂ O ₃ ), europium oxide (Eu ₂ O ₃ ), iron oxides such as iron (II,III) oxide (Fe ₃ O ₄ ) and iron (III) oxide (Fe ₂ O ₃ ), hafnium nitride (HfN), hafnium carbide (HfC), hafnium oxide (HfO ₂ ), lanthanum oxide (La ₂ O ₃ ), magnesium oxide (MgO), neodymium oxide (Nd ₂ O ₃ ), praseodymium oxide (Pr ₆ O ₁₁ ), samarium oxide (Sm ₂ O ₃ ), antimony trioxide (Sb ₂ O ₃ ), silicon carbide (SiC), silicon nitride (Si ₃ N ₄ ), Silicon monoxide (SiO), selenium trioxide (Se ₂ O ₃ ), tin oxide (SnO ₂ ), tungsten trioxide (WO ₃ ), high-refractive organic monomers and/or high-refractive organic polymers or be made from at least one of these materials.

The at least one spacer layer can be a low-refractive dielectric material with a refractive index less than or equal to 1.65, in particular selected from the group aluminum oxide (Al ₂ O ₃ ), metal fluorides, for example magnesium fluoride (MgF ₂ ), aluminum fluoride (AlF ₃ ), cerium fluoride (CeF ₃ ), sodium aluminum fluorides (eg Na ₃ AlF ₆ or Na ₅ Al ₃ F ₁₄ ), silicon oxide (SIO _x ), silicon dioxide (SiO ₂ ), neodymium fluoride (NdF ₃ ), lanthanum fluoride (LaF ₃ ), samarium fluoride (SmF ₃ ), barium fluoride (BaF ₂ ), calcium fluoride (CaF ₂ ), lithium fluoride (LiF), low-refractive organic monomers and/or low-refractive organic polymers or at least one high-refractive dielectric material with a refractive index greater than 1.65, in particular selected from the group zinc sulfide (ZnS), zinc oxide (ZnO), titanium dioxide (TiO ₂ ), carbon (C), indium oxide (In ₂ O ₃ ), indium tin oxide (ITO), tantalum pentoxide (Ta ₂ O ₅ ), cerium oxide (CeO ₂ ), yttrium oxide (Y ₂ O ₃ ), europium oxide (Eu ₂ O ₃ ), iron oxides such as iron (II,III) oxide (Fe ₃ O ₄ ) and iron (III) oxide (Fe ₂ O ₃ ), hafnium nitride (HfN), hafnium carbide (HfC), hafnium oxide (HfO ₂ ), lanthanum oxide (La ₂ O ₃ ), magnesium oxide (MgO), neodymium oxide (Nd ₂ O ₃ ), praseodymium oxide (Pr ₆ O ₁₁ ), samarium oxide (Sm ₂ O ₃ ), antimony trioxide (Sb ₂ O ₃ ), silicon carbide (SiC), silicon nitride (Si ₃ N ₄ ), silicon monoxide (SiO), selenium trioxide (Se ₂ O ₃ ), tin oxide (SnO ₂ ), tungsten trioxide (WO ₃ ), high-refractive organic monomers and/or high-refractive organic polymers or be made from at least one of these materials.

The security element 3 may be a partial layer or comprise a partial layer, wherein the partial layer may represent a portrait, a landscape, an abstract geometric symbol, logo or an alphanumeric symbol and/or an icon and/or a code and/or a sequence of symbols.

The Fig.6 shows a plan view of this substrate 1, whereby the security element 3 is already applied to the substrate 1. The previously described carrier layer 7 designed as a transfer film has already been removed or peeled off.

In the Figs. 7 and 8 An exemplary combination of the previously described embodiments is shown. The Fig.7 The layer structure shown comprises two areas with electrically conductive layers 2, 4 applied directly to the substrate 1. In the area between these two electrically conductive layers 2, 4, a security element 3 is also applied, which also comprises an electrically conductive layer 2. The layers 2, 4 can be the same or different. It is provided that the electrically conductive layers 2, 4 or their machine-readable codes are transparent in a wavelength range visible to the human eye. The transparent electrically conductive layers 2, 4 can have a transmittance of 0 to 0.5, preferably from 0 to 0.3, particularly preferably from 0 to 0.1. The Fig.8 shows a top view of this layer structure. It is conceivable that the directly applied areas with electrically conductive layers 2, 4 and/or the applied security element 3 touch or overlap. It is also conceivable, however, that the areas with electrically conductive layers 2, 4 and the security element 3 are at least partially spaced apart from one another, whereby non-electrically conductive free areas 9 can be provided. Substrates 1 are usually covered with a primer 10 as a preparatory step before a subsequent banknote printing. Such a primer 10 can be white or essentially white, as is known per se. The primer 10 can, as in the Fig.7 shown, also be introduced into the free areas 9, so that the substrate 1 receives at least a largely smooth surface.

The embodiments show possible embodiment variants, whereby it should be noted at this point that the invention is not restricted to the specifically illustrated embodiment variants thereof, but rather various combinations of the individual embodiment variants with each other are also possible and this possibility of variation lies within the skill of the person skilled in the art in this technical field due to the teaching of technical action through objective invention.

The scope of protection is determined by the claims. However, the description and the drawings are to be used to interpret the claims. Individual features or Combinations of features from the different embodiments shown and described can represent independent inventive solutions in themselves. The task underlying the independent inventive solutions can be taken from the description.

All information on value ranges in the description in question is to be understood as including any range and all subranges thereof, e.g. the information 1 to 10 is to be understood as including all subranges starting from the lower limit 1 and the upper limit 10, i.e. all subranges begin with a lower limit of 1 or greater and end with an upper limit of 10 or less, e.g. 1 to 1.7, or 3.2 to 8.1, or 5.5 to 10.

Finally, for the sake of clarity, it should be noted that in order to better understand the structure, some elements have been shown not to scale and/or enlarged and/or reduced.

Reference symbol list

1

Substrat

2

electrically conductive layer

3

Security element

4

additional electrically conductive layer

5

Visible side

6

Primers

7

Carrier layer

8

Heat seal varnish

9

Outdoor area

10

primer

Claims (13)

Substrate (1) for producing securities or security papers, such as banknotes, identity cards, credit cards, characterized in that it has an electrically conductive layer (2) with a machine-readable coding, which electrically conductive layer (2) is transparent in a wavelength range visible to a human eye. Substrate (1) according to claim 1, characterized in that the electrically conductive layer (2) has a transmittance of 0 to 0.5, preferably from 0 to 0.3, particularly preferably from 0 to 0.1. Substrate (1) according to one of the preceding claims, characterized in that the electrically conductive layer (2) is applied to one side of the substrate (1), or that the electrically conductive layer (2) is introduced into the substrate (1). Substrate (1) according to one of the preceding claims, characterized in that the electrically conductive layer (2) is designed as a security element (3) or as part of a security element (3), wherein the security element (3) is applied to the substrate (1), or wherein the security element (3) is introduced into the substrate (1). Substrate (1) according to one of the preceding claims, characterized in that the electrically conductive layer (2) is a printed layer. Substrate (1) according to one of the preceding claims, characterized in that the electrically conductive layer (2) comprises a non-metallic conductive material. Substrate (1) according to claim 6, characterized in that the non-metallic conductive material contained in the electrically conductive layer (2) comprises an electrically conductive polymer. Substrate (1) according to claim 6 or 7, characterized in that the non-metallic conductive material contained in the electrically conductive layer (2) comprises an electrically conductive graphite-containing lacquer. Substrate (1) according to one of the preceding claims, characterized in that the electrically conductive layer (2) completely or partially covers the substrate (1). Substrate (1) according to one of the preceding claims, characterized in that in addition to the electrically conductive layer (2), a further electrically conductive layer (4) is formed, which further electrically conductive layer (4) is transparent in a wavelength range visible to a human eye. Substrate (1) according to one of the preceding claims, characterized in that the substrate (1) is a polymer substrate. Security paper or security document , characterized in that it comprises a substrate (1) according to one of claims 1 to 11. Security or safety paper according to claim 12, characterized in that the security or safety paper is a polymer security or polymer safety paper.

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