Biodegradable value document substrate

Abstract

The invention relates to a machine-recognizable, biodegradable polymeric value document substrate, comprising a polymeric composite substrate, which is at least substantially based on renewable raw materials, and at least one machine-recognizable feature embedded in the composite substrate, the machine recognizable feature exhibits a characteristic luminescent emission upon excitation with light of a suitable wavelength, in particular upon excitation with light of the ultraviolet or infrared wavelength range.

Description

[0001] The invention relates to a machine-readable, biodegradable polymer value-document substrate, in particular a banknote.

[0002] Plastic-based value-document substrates, in particular polymer banknotes, are known in the prior art. WO 83 / 00659 A1 describes a substrate based on a transparent biaxially oriented polymer for use in producing banknotes or identification documents. Furthermore, WO 2004 / 028825 A2 describes a film / paper / film composite substrate as a suitable value-document substrate for producing banknotes.

[0003] Valuable documents, particularly banknotes, are subject to high loads during circulation, leading to contamination and mechanical damage. Typically, the machine-readable characteristic material used to render the value document substrate machine-readable is applied to the value document substrate using a printing ink or coating containing the machine-readable characteristic material. Consequently, the characteristic material can be easily lost due to mechanical wear during circulation. Furthermore, the characteristic material located on the surface of the value document substrate can be easily removed by counterfeiters and used to produce counterfeit value documents.

[0004] Furthermore, currently known polymeric value-document substrates are based on plastics such as biaxially oriented polypropylene (BOPP), etc. These plastics are derived from fossil raw materials and are not biodegradable.

[0005] The technical problem to be solved by the present invention is to overcome the disadvantages of the prior art and to provide an improved value-document substrate which should ensure sustainable and environmentally friendly disposability and production while having a high circulation durability.

[0006] The technical problem is solved by the combination of features defined in the independent claims. Developments of the invention are the subject of the dependent claims. Summary of the Invention

[0007] The present invention comprises a machine-readable, biodegradable polymer value-document substrate, comprising a polymer composite substrate based at least essentially on renewable raw materials and at least one machine-readable characteristic substance embedded in the composite substrate, wherein the machine-readable characteristic substance exhibits (or has) a characteristic luminescence emission when excited with light of a suitable wavelength, in particular with light in the ultraviolet or infrared wavelength range.

[0008] A "biodegradable" value-document substrate is understood here to be a material that can be broken down by microorganisms into toxicologically harmless end products. In addition to water and biomass, CO 2 is also produced. The decomposition process can be accelerated by industrial composting facilities or biogas plants.

[0009] In a preferred embodiment, the polymer composite substrate based at least essentially on renewable raw materials has at least two interconnected polymer layers, wherein the machine-identifiable characteristic substance is embedded in one of the at least two interconnected polymer layers, wherein the machine-identifiable characteristic substance is preferably embedded in only one of the at least two interconnected polymer layers.

[0010] In a likewise advantageous embodiment, the polymer composite substrate based at least substantially on renewable raw materials comprises at least two polymer layers connected to one another by an adhesive layer, wherein the machine-recognizable feature substance is embedded in the adhesive layer.

[0011] In another advantageous embodiment, the polymer composite substrate based at least essentially on renewable raw materials has two outer polymer layers and a central layer, wherein the central layer is a polymer layer or a paper layer, wherein the two outer polymer layers and the central layer are connected to each other via two adhesive layers, wherein the machine-identifiable characteristic substance is embedded in at least one of the two adhesive layers, wherein the machine-identifiable characteristic substance is preferably embedded in only one of the two adhesive layers.

[0012] It is particularly advantageous if the valuable-document substrate has two different machine-identifiable characteristic substances, wherein the two characteristic substances are individually embedded in different components of the valuable-document substrate, thereby forming separate valuable-document substrate areas that can be distinguished from one another on the basis of the respective characteristic substances.

[0013] The polymer composite matrix based at least essentially on renewable raw materials is advantageously based on starch, starch derivatives, cellulose, cellulose derivatives, cellulose diacetate (CDA), lignin, polylactic acid or polylactide (PLA), polyhydroxyalkanoates (PHF), in particular polyhydroxybutyrate (PHB) and / or polyhydroxyvalerate (PHV), polybutylene adipate-terephthalate (BTA copolyester), chitin, chitosan or casein, or a mixture of two or more of the above substances.

[0014] Advantageously, the machine-identifiable feature embedded in the composite substrate is visually discernible in daylight and is preferably present in the form of fibers, mixed-color fibers, flakes, or particles.

[0015] According to various advantageous inventive variants, the machine-recognizable feature substance embedded in the composite substrate is not visually recognizable in daylight but is only recognizable upon irradiation with UV light and is preferably present in the form of fibers, mixed-color fibers, flakes or particles.

[0016] In a further advantageous inventive variant, the machine-recognizable characteristic substance embedded in the composite matrix is ​​not discernible to the naked eye, is present in the form of particles, ie pigments, and exhibits a characteristic luminescence emission upon excitation with light in the ultraviolet or infrared wavelength range.

[0017] Preferably, the machine-identifiable characteristic substance is an inorganic substance and exists in the form of a host lattice doped with luminescent ions.

[0018] According to a preferred embodiment, the value-document substrate is a banknote.

[0019] Detailed Description of the Preferred Embodiments

[0020] The present invention is based on the recognition that it is possible to provide a sustainable valuable-document substrate that can be disposed of in an environmentally friendly manner and at the same time has a high circulation durability and machine recognizability, in that the valuable-document substrate comprises a polymer composite substrate based at least essentially on renewable raw materials and at least one machine-recognizable characteristic substance embedded in the composite substrate, wherein the machine-recognizable characteristic substance exhibits a characteristic luminescence emission when excited with light of a suitable wavelength, in particular when excited with light in the ultraviolet wavelength range or the infrared wavelength range.

[0021] The value-document substrate according to the present invention and the value documents obtained therefrom, in particular banknotes, have favorable sustainability characteristics and a low carbon footprint. At the end of their product lifecycle, the value documents obtained based on the value-document substrate according to the present invention are recyclable and biodegradable, i.e., compostable. At the same time, due to the machine-readable characteristic substance embedded in the composite substrate, the value-document substrate and the value documents obtained therefrom can be reliably verified for authenticity. Due to this embedding, the machine-readable characteristic substance can be said to be built-in and therefore cannot be lost during the circulation of the value document due to mechanical wear of printing inks or coatings applied to the surface of the value document. Furthermore, the built-in machine-readable characteristic substance cannot be removed by currency counterfeiters and used to produce counterfeit value documents.

[0022] A machine-identifiable signature substance which exhibits a characteristic luminescence emission upon excitation with light of a suitable wavelength can in particular be excited to emit light with light in the UV wavelength range or in the IR wavelength range.

[0023] According to a preferred embodiment, the machine-recognizable characteristic substance is visible to the naked eye in daylight and is in the form of fibers, mixed-color fibers, flakes or particles. The technical advantage of this embodiment is that the authenticity of the corresponding value document can be verified without additional technical assistance.

[0024] According to another preferred embodiment, the machine-identifiable characteristic substance is invisible to the naked eye under sunlight but is visible to the naked eye when exposed to UV light and is present, in particular, in the form of fibers, mixed-color fibers, flakes, or particles. The technical advantage of this embodiment is that verifying the authenticity of the corresponding value document requires additional technical assistance, in particular UV light, and copying the corresponding value document requires a higher technical investment. Consequently, anti-counterfeiting security is significantly improved.

[0025] According to another preferred embodiment, the machine-recognizable characteristic substance is not recognizable to the naked eye, exists in the form of particles, i.e., pigments, and exhibits characteristic luminescent emission when excited by light in the UV wavelength range or the IR wavelength range. Machine recognition requires, for example, a luminescent microscope or a banknote detection system equipped with appropriate sensors. The D99 particle size of these particles is advantageously in the range of 1-30 microns, preferably in the range of 5-20 microns, further preferably in the range of 10-20 microns and particularly preferably in the range of 15-20 microns. The technical advantage of this embodiment is that the authenticity of the corresponding valuable document can only be verified by complex technical methods such as luminescence spectroscopy. Therefore, the anti-counterfeiting security is extremely high. The machine-recognizable characteristic substance is advantageously an inorganic substance and exists in the form of a host lattice doped with luminescent ions.

[0026] The value document substrate according to the present invention comprises a polymer composite substrate based at least essentially on renewable raw materials. According to a preferred embodiment, the polymer composite substrate comprises at least two interconnected polymer layers, wherein a machine-identifiable characteristic substance is embedded in one of the at least two interconnected polymer layers. Preferably, the machine-identifiable characteristic substance is embedded in only one of the at least two interconnected polymer layers. Embedding the characteristic substance in only one of the at least two interconnected polymer layers improves the anti-counterfeiting protection of the corresponding value document. If the two interconnected polymer layers are artificially separated, a counterfeiter cannot use two polymer layers of equal value to produce two counterfeit value documents.

[0027] In principle, characteristic material can be fully or partially, ie locally embedded. When partially embedded, it can be embedded in the form of characters, in the form of coding or in the form of patterns, such as stripes or blocks, as needed.

[0028] According to another preferred embodiment, the polymer composite substrate comprises at least two polymer layers connected to each other by an adhesive layer, wherein the machine-recognizable characteristic substance is embedded in the adhesive layer. In this case as well, the characteristic substance can be fully or partially, ie locally, embedded.

[0029] According to another preferred embodiment, the polymer composite substrate has two outer polymer layers and a central layer, wherein the central layer is a polymer layer or a paper layer, wherein the two outer polymer layers and the central layer are connected to each other by two adhesive layers, wherein a machine-identifiable characteristic substance is embedded in at least one of the two adhesive layers, wherein the machine-identifiable characteristic substance is preferably embedded in only one of the two adhesive layers. Embedding the characteristic substance in only one of the two adhesive layers improves the anti-counterfeiting protection of the corresponding valuable document. In the case of artificial separation of the three-layer composite structure, a counterfeiter cannot use two halves of equal value to produce a counterfeit valuable document. In principle, valuable document substrates having a polymer layer / paper substrate / polymer layer structure are known in the prior art, see document WO 2004 / 028825 A2, and such valuable document substrates are also called film composite substrates.

[0030] According to another preferred embodiment, polymer composite substrate has two outer polymer layers and a central polymer layer, wherein, in particular, the central polymer layer is based on renewable raw materials and the two outer polymer layers are designed to improve the printability of the valuable document substrate to printing ink respectively, thereby providing an ink-receiving layer or a printing-receiving layer in this way. The outer polymer layer can be suitably a thin polyethylene terephthalate (PET) layer respectively, and the surface of the PET layer is equipped with a composition that improves ink acceptance or printing acceptance when necessary, wherein the composition is especially based on polymer binders and filler pigments, such as SiO2 pigment, TiO2 pigment or Al2O3 pigment. Ink-receiving layers are known in the prior art, referring to, for example, document WO 2012 / 003947 A1.

[0031] According to another preferred embodiment, the value document substrate according to the present invention has two different machine-identifiable characteristic substances, wherein the two characteristic substances are separately embedded in different components of the value document substrate, thereby forming separate value document substrate areas that can be distinguished based on their respective characteristic substances. For example, one characteristic substance can be embedded in a first polymer layer, and the other characteristic substance can be embedded in a second polymer layer. Alternatively, one characteristic substance can be embedded in a polymer layer, and the other characteristic substance can be embedded in an adhesive layer.

[0032] The polymer composite substrate based at least substantially on renewable raw materials can be based in particular on starch, starch derivatives, cellulose, cellulose derivatives, cellulose diacetate (CDA), lignin, polylactic acid or polylactide (PLA), polyhydroxyalkanoates (PHF), in particular polyhydroxybutyrate (PHB) and / or polyhydroxyvalerate (PHV), polybutylene adipate-terephthalate (BTA copolyester), chitin, chitosan or casein, or mixtures of two or more of the aforementioned substances. Cellulose diacetate (CDA) in particular has very advantageous properties with regard to technical processability.

[0033] According to another preferred embodiment, the value-document substrate according to the invention is designed with a security thread and / or security strip and / or security patch based on biodegradable materials and / or mixed-color fibers based on natural fibers. In this way, a value-document substrate that is particularly advantageous in terms of recyclability can be provided.

[0034] The value-document substrate according to the invention is in particular a banknote or a security paper suitable for producing a banknote.

[0035] Further embodiments and advantages of the invention are described below with reference to the accompanying drawings, which, for the sake of clarity, are not shown true to scale.

[0036] In the attached figure:

[0037] Figure 1 shows a cross-sectional view of a value-document substrate according to a first embodiment;

[0038] Figure 2 shows a cross-sectional view of a value-document substrate according to a second embodiment;

[0039] Figure 3 A cross-sectional view showing a value-document substrate according to a third embodiment; and

[0040] Figure 4 A cross-sectional view of a value-document substrate according to a fourth embodiment is shown.

[0041] Figure 1 According to a first embodiment, a machine-readable, biodegradable polymer value document substrate according to the present invention is shown, which has a polymer composite substrate with two interconnected polymer layers 11 and 12. The machine-readable characteristic substance is embedded only in the polymer layer 12. The material used to make the polymer layers 11 and 12 is biodegradable polybutylene adipate-terephthalate (BTA copolyester). The machine-readable characteristic substance is an inorganic substance known from document WO 2011 / 084663 A2, which exists in the form of individual particles that are not recognizable to the naked eye and is based on a host lattice doped with luminescent ions. The characteristic substance can be detected by a luminescence microscope and has the chemical formula Y 2.88Er 0.1 Tm 0.01 Ho 0.01 Ga5O 12 The matrix or host lattice has the elements Y, Ga and O. The doping elements are composed of Er, Tm and Ho.

[0042] Embedding a characteristic substance in only one of at least two interconnected polymer layers improves the anti-counterfeiting protection of the corresponding value document. If the two interconnected polymer layers are artificially separated, a counterfeiter cannot produce two counterfeit value documents using two polymer layers of equal value. Furthermore, the value document substrate ensures sustainable and environmentally friendly disposability while exhibiting high circulation durability due to the built-in characteristic substance and the resulting protection against mechanical wear.

[0043] Figure 2 According to the second embodiment, a machine-recognizable, biodegradable polymer value document substrate according to the present invention is shown, which has a polymer composite substrate having two polymer layers 21 and 23 connected to each other by an intermediate layer 22, i.e., an adhesive layer. The machine-recognizable characteristic substance is only embedded in the intermediate layer 22. The material used to make the polymer layers 21 and 23 is biodegradable polylactic acid or polylactide (Polylactid, PLA). As the machine-recognizable characteristic substance, a mixed color fiber that is recognizable to the naked eye under UV light irradiation is used. The value document substrate can be verified for authenticity with the naked eye with the aid of a UV lamp and has sustainable and environmentally friendly disposability. In addition, high circulation durability is ensured due to the built-in provision of the characteristic substance and the protection against mechanical wear.

[0044] Figure 3 According to a third embodiment, a machine-readable, biodegradable polymer value document substrate according to the present invention is shown in the form of a three-layer polymer composite structure with polymer layers 31, 32 and 33. These polymer layers are each based on polyhydroxybutyrate (PHB). The machine-readable characteristic substance is embedded only in the central polymer layer 32. As the machine-readable characteristic substance, an inorganic substance known from document EP 1 241 242 A2 is used. This substance exists in the form of individual particles that are not visible to the naked eye and is based on a host lattice doped with luminescent ions. This characteristic substance can be detected by a luminescence microscope and has the chemical formula Gd 1.89 Yb 0.1 Tm 0.01 O2S. The valuable document substrate ensures sustainable and environmentally friendly disposability and at the same time a high degree of circulation durability, as the characteristic substance is provided internally and is therefore protected against mechanical wear.

[0045] Figure 4According to the fourth embodiment, machine identification according to the present invention, biodegradable polymer valuable document base material is illustrated, and its form is five-layer polymer composite structure.Polymer composite base material comprises two outer polymer layers 42 and 44 and a central polymer layer 43, wherein, central polymer layer 43 is based on renewable raw materials, for example polybutylene adipate-terephthalate (BTA copolyester).In this example, polymer layer 42 and 44 is respectively thin polyethylene terephthalate (PET) layer, is wherein embedded with machine identification characteristic material respectively.Polymer layer 42 and 44 has ink-receiving layer 41 and 45 respectively on the surface, and ink-receiving layer improves the printability of valuable document base material to printing ink.Two ink-receiving layers 41 and 45 are respectively based on following composition, and this composition is based on polymer binder and filler pigment.

Claims

1. A machine-readable, biodegradable polymeric value document substrate comprising a polymeric composite substrate at least substantially based on renewable raw materials and at least one machine-readable characteristic substance embedded in the composite substrate, wherein: The machine-recognizable characteristic substance exhibits a characteristic luminescence emission upon excitation with light of an appropriate wavelength, in particular with light in the ultraviolet wavelength range or the infrared wavelength range.

2. The machine-readable, biodegradable polymer value document substrate according to claim 1, wherein: The polymer composite substrate, which is at least essentially based on renewable raw materials, has at least two interconnected polymer layers, wherein a machine-identifiable characteristic substance is embedded in one of the at least two interconnected polymer layers, wherein the machine-identifiable characteristic substance is preferably embedded in only one of the at least two interconnected polymer layers.

3. The machine-readable, biodegradable polymer value document substrate according to claim 1, wherein: The polymer composite substrate based at least substantially on renewable raw materials comprises at least two polymer layers connected to one another by an adhesive layer, wherein a machine-recognizable feature is embedded in the adhesive layer.

4. The machine-readable, biodegradable polymer value document substrate according to claim 1, wherein: The polymer composite substrate based at least essentially on renewable raw materials has two outer polymer layers and a central layer, wherein the central layer is a polymer layer or a paper layer, wherein the two outer polymer layers and the central layer are connected to each other via two adhesive layers, wherein a machine-identifiable characteristic substance is embedded in at least one of the two adhesive layers, wherein the machine-identifiable characteristic substance is preferably embedded in only one of the two adhesive layers.

5. The machine-recognizable, biodegradable polymer value-document substrate according to any one of claims 1 to 4, wherein: The value-document substrate has two different machine-recognizable characteristic substances, wherein the two characteristic substances are individually embedded in different components of the value-document substrate, thereby forming separate value-document substrate areas that can be distinguished from each other based on the respective characteristic substances.

6. The machine-recognizable, biodegradable polymer value-document substrate according to any one of claims 1 to 5, wherein: The polymer composite substrate based at least essentially on renewable raw materials is based on starch, starch derivatives, cellulose, cellulose derivatives, cellulose diacetate (CDA), lignin, polylactic acid or polylactide (PLA), polyhydroxyalkanoates (PHF), in particular polyhydroxybutyrate (PHB) and / or polyhydroxyvalerate (PHV), polybutylene adipate-terephthalate (BTA copolyester), chitin, chitosan or casein, or a mixture of two or more of the above substances.

7. The machine-recognizable, biodegradable polymer value-document substrate according to any one of claims 1 to 6, wherein The machine-identifiable features embedded in the composite substrate are visually discernible in daylight and are preferably present in the form of fibers, mixed-color fibers, flakes, or particles.

8. The machine-recognizable, biodegradable polymer value-document substrate according to any one of claims 1 to 6, wherein The machine-identifiable characteristic substance embedded in the composite substrate is not visually discernible under daylight but is visually discernible upon illumination with ultraviolet light and is preferably present in the form of fibers, mixed-color fibers, flakes, or particles.

9. The machine-recognizable, biodegradable polymer value-document substrate according to any one of claims 1 to 6, wherein: The machine-recognizable characteristic substance embedded in the composite matrix is ​​not recognizable to the naked eye, is present in the form of particles, ie pigments, and exhibits a characteristic luminescence emission upon excitation with light in the ultraviolet or infrared wavelength range.

10. The machine-readable, biodegradable polymer value document substrate according to claim 9, wherein: The machine-recognizable characteristic substance is an inorganic substance and exists in the form of a host lattice doped with luminescent ions.

11. The machine-recognizable, biodegradable polymer value-document substrate according to any one of claims 1 to 10, wherein: The valuable document substrate is a banknote.

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