Valuable document substrate

Abstract

The invention relates to a value document substrate comprising a fibrous substrate body provided on at least one main surface thereof with an anti-fouling layer, characterized in that the anti-fouling layer can be obtained from a formulation based substantially on sustainable raw materials and has an anti-fouling layer which can be produced according to the ASTM D6866, preferably according to the ASTM D6866, preferably according to the ASTM D6866, preferably according to the ASTM D6866, preferably according to the ASTM D6866, preferably according to the ASTM D6866. The invention relates to a method for testing the biomass content of the value document substrate, in which the biomass content is determined by method A in the range of 35 to 100, and during the contamination test, the degree of contamination of the value document substrate, expressed as the difference in brightness [Delta] L, is in the range of 0 to 40, which can be determined by means of a spectrophotometer.

Description

Technical Field

[0001] During the circulation of value documents, value document substrates, especially banknotes, are subjected to high loads, which lead to soiling and mechanical damage. With regard to improving circulation durability, patent document WO 2004 / 072378 A1 proposes to provide security paper with a lacquer-based protective layer. Patent document WO 2004 / 028825 A2 describes the provision of security paper improved in terms of antifouling, which has an increased mechanical strength based on a multi-layer substrate, which comprises at least a paper layer and a film. Background Art

[0002] A disadvantage of the prior art methods for providing value-document substrates with increased circulation durability is that the starting materials required for this originate from petrochemicals, which creates difficulties with regard to the CO2 footprint, ecological balance and sustainability. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the disadvantages of the prior art and provide an improved value-document substrate, which should in particular ensure the replacement of petrochemical raw materials by biological renewable raw materials and at the same time have high circulation durability.

[0004] The technical problem is solved by a value-document substrate.

[0005] The present invention includes a valuable document substrate, which includes a fibrous substrate body, which is provided with an anti-fouling layer on at least one main surface thereof, characterized in that the anti-fouling layer can be obtained from a formulation that is essentially based on sustainable raw materials and has a biomass percentage content in the range of 35 to 100 that can be determined according to ASTM D6866, method B, and when performing a contamination test, the degree of contamination of the valuable document substrate represented by the brightness difference ΔL is in the range of 0 to 40, and the degree of contamination can be determined by a spectrophotometer.

[0006] In a preferred design, the antifouling layer has a biomass percentage content in the range of 35-60, which can be determined according to ASTM D6866, method B, and when performing a contamination test, the degree of contamination of the valuable document substrate, represented by the difference in brightness ΔL, is in the range of 0 to 30, preferably 0 to 15, and the degree of contamination can be determined by a spectrophotometer.

[0007] The antifouling layer advantageously comprises a binder based on polyurethane and / or acrylate.

[0008] In an advantageous embodiment, the fiber substrate body comprises a wet strength agent based on polyamide-epichlorohydrin (PAAE) resin and / or a dry strength agent based on carboxymethylcellulose and / or styrene-butadiene and / or a surface sizing agent based on polyvinyl alcohol.

[0009] In a further advantageous embodiment, the antifouling layer additionally contains a biocidal additive, in particular a fungicidal, bactericidal and / or virucidal additive.

[0010] In an advantageous configuration, the fiber matrix body comprises natural fibers, wherein the natural fibers are obtained from plants selected from flax, cellulose, sisal or a mixture of two or more of the above plants.

[0011] In a similarly advantageous embodiment, the fiber matrix body comprises bio-based plant polymer fibers, wherein the bio-based plant polymer fibers are bio-based polyamide fibers, tencel fibers, thermoplastic polyurethane fibers, castor fibers, polylactic acid fibers and / or protein fibers, wherein the protein fibers are obtained in particular from corn, peanuts, milk and / or soybeans.

[0012] It is preferred that an antifouling layer be provided on each of the two main surfaces of the fiber base material.

[0013] In an advantageous variant of the invention, the fiber matrix body is biodegradable and based on sustainable fibers, wherein the sustainable fibers are in particular selected from natural fibers, regenerated cellulose fibers, bio-based plant polymer fibers, bio-based animal polymer fibers or a mixture of two or more of the above components.

[0014] In an advantageous variant of the present invention, the fiber substrate body is a multilayer fiber substrate body having a polymer layer / paper substrate / polymer layer structure or a paper substrate / polymer layer / paper substrate structure, wherein the polymer layer is biodegradable and is particularly selected from cellulose, polybutylene terephthalate (BTA copolyester), polylactic acid (PLA), particularly biaxial polylactic acid, polyhydroxybutyric acid (PHB), or a mixture of two or more of the above components.

[0015] Particularly advantageously, the value-document substrate has a security thread and / or a security strip and / or a security patch based on recycled material or biomaterial and / or hybrid fibers based on natural fibers.

[0016] Value-document substrates are, in particular, banknotes.

[0017] Detailed description of preferred embodiments

[0018] The coatings or impregnation structures known from the prior art that are provided on value documents such as banknotes are based on petrochemical sources. The concept on which the present invention is based is to replace chemicals of petrochemical origin with renewable raw materials. It has been shown that a sustainable value document substrate with both excellent antifouling properties and improved circulation durability can be provided as follows, in that a fibrous substrate body is provided with an antifouling layer on at least one of its main surfaces, wherein the antifouling layer is produced by a formulation based primarily on sustainable raw materials.

[0019] The antifouling property can be determined quantitatively experimentally in a so-called analyzer, i.e. a vibrating screen, by the change in the brightness value L before and after treatment with a defined dirt solution. For example, the "analysette 3PRO" vibrating screen sold by Fritsch of Idar-Oberstein is suitable as such a vibrating screen. The contamination test is carried out with dirt purchased from the company (especially based on dried and ground peat, quartz sand, activated carbon and glycerol-1-monooleate) and glass beads with a diameter of 7 mm purchased from Mühlmeier. The document substrate to be tested with a size of 17.5 cm×7.5 cm is fixed to a PVC film with a thickness of 200 μm with the help of adhesive tape, and the PVC film is then placed on the sieve bottom of a vibrating screen. 270 g of glass beads are added and 1.5 g of the dirt mixture are distributed over the glass beads. After closing the vibrating screen, the valuable document substrate to be tested is contaminated with a set amplitude of 1.5 over a period of 20 minutes, i.e. treated with the contamination mixture. Before removing the valuable document substrate from the PVC film, it must be wiped clean with a paper towel, such as Kimberly-Clark's ) until no more dirt is visible on the paper towel. The degree of soiling is determined by means of a spectrophotometer, for example an instrument of the brand ELREPHO 450X, as a brightness difference ΔL.

[0020] The proportion of renewable raw materials can be determined with the aid of the so-called C14 method. The proportion of the 14C isotope in organic materials is determined with the aid of the C14 method. This method is a recognized, reliable method that is specified in test standards and has been proven to be useful, for example, in archaeology for determining the age of bones. The C14 activity indicates the percentage share of biogenic carbon in the respective object. Standard ASTM D 6866, method B, is suitable for determining the percentage share of biomass. Method B uses together the so-called accelerator mass spectrometry (AMS) and isotope ratio mass spectrometry (IRMS).

[0021] According to the invention, the antifouling layer can be obtained from a formulation based essentially on sustainable raw materials. In addition to solvents, especially water, the formulation based essentially on sustainable raw materials preferably also essentially has paint components and / or chemical additives with a high biocarbon content. The antifouling layer has a biomass percentage content that can be determined according to ASTM D6866, method B in the range of 35-100, preferably 35-60.

[0022] When carrying out the soiling test, the valuable document substrate has a degree of soiling expressed as a difference in brightness ΔL in the range of 0 to 40, preferably 0 to 30, more preferably 0 to 25, particularly preferably 0 to 15, which can be determined by a spectrophotometer (such as a device with the brand name ELREPHO 450X).

[0023] The higher the C14 content in the corresponding additives, adhesives, etc. and the more renewable raw materials are used, the higher the C14 content in the paint components and chemical additives composed of renewable raw materials. It should be ensured that the replacement of petrochemical materials with renewable raw materials does not impair the circulation durability. In addition, when the material is used in larger quantities to reach a certain saturation limit, the characteristic of extending the circulation durability, i.e. the service life, of the corresponding valuable documents, such as banknotes, is generally achieved. Therefore, there is a positive correlation between the amount of recycled components used, i.e. the C14 content, and the circulation durability, i.e. the service life, of the relevant valuable documents.

[0024] The formulation for obtaining the antifouling layer, which is essentially based on sustainable raw materials, preferably comprises a polyurethane-based adhesive and / or an acrylate-based adhesive.

[0025] The above mentioned ingredients have proven to be particularly advantageous with regard to test parameters such as reduced Cobb value, reduced porosity, low oil absorption and thus very good stain resistance combined with excellent printability and pigment adhesion.

[0026] According to another preferred embodiment, the antifouling layer additionally contains a bactericidal additive, in particular a fungicidal, bactericidal and / or virucidal additive. As a bactericidal additive, preferably an agent selected from the following group can be used, the group consisting of 1,2-benzisothiazol-3(2H)-one (BIT), 3-iodo-2-propenylbutylcarbamate (IPBC), a silver-containing compound, a silver salt, such as silver phosphate glass, and a combination of two or more of the above components. In addition, photosensitizers for generating singlet oxygen can also be used as bactericidal additives, for example, see the photosensitizers known from patent document WO 2021 / 197663 A1.

[0027] Furthermore, if necessary, the fiber matrix body may additionally have natural fibers, wherein the natural fibers may be obtained from plants selected from the group consisting of flax, cellulose, sisal or a mixture of two or more of the above plants.

[0028] According to another preferred design scheme, the anti-fouling layer also additionally has bio-based plant polymer fibers, wherein the bio-based plant polymer fibers are bio-based polyamide fibers, Tencel fibers, thermoplastic polyurethane fibers (i.e., for example, thermoplastic polyurethane-based fibers from Covestro), castor fibers, polylactic acid fibers and / or protein fibers, wherein the protein fibers are especially obtained from corn, peanuts, milk and / or soybeans.

[0029] Preferably, both main surfaces of the fiber base body are provided with an antifouling layer.

[0030] According to a preferred embodiment, the fiber matrix body is mostly biodegradable and based on sustainable fibers, wherein the sustainable fibers are in particular selected from the group consisting of natural fibers, regenerated cellulose fibers, bio-based plant polymer fibers, bio-based animal polymer fibers or a mixture of two or more of the above components.

[0031] According to another preferred embodiment, the fiber substrate body is a multi-layer fiber substrate body having a polymer layer / paper substrate / polymer layer structure or a paper substrate / polymer layer / paper substrate structure, wherein the polymer layer is biodegradable and is particularly selected from the following group, which consists of cellulose, polybutylene terephthalate (BTA copolyester), polylactic acid (PLA), especially biaxial polylactic acid, polyhydroxybutyric acid (PHB), or a mixture of two or more of the above components.

[0032] The value-document substrate according to the invention can preferably have a security thread and / or a security strip and / or a security sticker based on biodegradable materials and / or hybrid fibers based on natural fibers.

[0033] The value-document substrate according to the invention is in particular a banknote or a security paper suitable for producing a banknote. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Further embodiments and advantages of the invention are described below with reference to the drawings, which are not shown to scale for the sake of greater clarity.

[0035] In the attached picture:

[0036] Figure 1The percentage biomass content of the antifouling layer determined according to ASTM D6866, method B is plotted against the degree of soiling as a difference in brightness ΔL determined by a spectrophotometer (ELREPHO 450X), wherein the measurement was carried out for each individual value-document substrate. DETAILED DESCRIPTION

[0037] Embodiment 1:

[0038] Recipes based on polyurethane binders (so-called “green LPT” recipes) suitable for producing antifouling layers are essentially based on sustainable raw materials and have the following composition:

[0039] - 97 parts of "NuVeraDRU-94-227" (Stahl hemie, biomass share 66% from sugar);

[0040] - 3 parts "Desmodur 2802" (Covestro);

[0041] -100 parts of water.

[0042] Embodiment 2:

[0043] Suitable for producing antifouling layers are polyacrylate-based formulations (so-called “Green LL” formulations) which are essentially based on sustainable raw materials and have the following composition:

[0044] - 95 shares of "Decovery SP 7450" (Covestro, 39% biomass share);

[0045] - 5 parts "NeoAdd Pax 523" (Covestro);

[0046] -35 parts water.

[0047] Embodiment 3:

[0048] A formulation suitable for producing an antifouling layer was prepared by combining the "Green LPT" formulation described in Example 1 with the "Green LL" formulation described in Example 2.

[0049] Comparative Example 1:

[0050] A suitable formulation for producing an antifouling layer that is not based on sustainable raw materials (the so-called “Standard LL” formulation) has the following composition:

[0051] - 61.8 parts of NeoCryl 2092 (Covestro);

[0052] - 4.6 parts Aquacer9 RC 1452 (Byk);

[0053] - 3.0 parts of Permutex XR 2500 (Stahl);

[0054] -30.6 parts of water.

[0055] Comparative Example 2:

[0056] A suitable formulation for producing an antifouling layer that is not based on sustainable raw materials (the so-called “standard LPT” formulation) has the following composition:

[0057] - 32.5 parts of Liopur 2004-140 (Synthopol);

[0058] - 0.15 parts of glycerol;

[0059] - 0.05 parts Byk 1640 (Byk Company);

[0060] - 0.8 parts of Desmodur 2802 (Covestro);

[0061] -66.5 parts of water.

[0062] Comparative Example 3:

[0063] The "standard LL" formulation described in Comparative Example 1 and the "standard LPT" formulation described in Comparative Example 2 were combined to produce a formulation suitable for producing an antifouling layer that is not based on sustainable raw materials.

[0064] Production of value-document substrates according to the invention and not according to the invention, measurement of the individual value-document substrates at The brightness value (ΔL value) after the pollution treatment is carried out and the biomass percentage share of the corresponding antifouling layer is determined:

[0065] The value-document substrate in the examples described is in each case a paper substrate suitable for producing banknotes, which is provided with an antifouling layer over the entire surface on both main surfaces.

[0066] Value-document substrate 1 (according to the invention) : The formulation used to make the antifouling layer is according to Example 3.

[0067] Value-document substrate 2 (according to the invention) : The formulation used to make the antifouling layer is based on Example 2.

[0068] Value-document substrate 3 (not according to the invention) : The formulation used to make the antifouling layer is based on Comparative Example 3.

[0069] Value-document substrate 4 (not according to the invention) : The formulation used to make the antifouling layer is based on Comparative Example 1.

[0070] A total of nine valuable document substrates are manufactured, namely, two valuable document substrates according to the present invention manufactured independently according to the above-mentioned "valuable document substrate 1", two valuable document substrates according to the present invention manufactured independently according to the above-mentioned "valuable document substrate 2", three valuable document substrates not according to the present invention manufactured independently according to the above-mentioned "valuable document substrate 4", and two valuable document substrates not according to the present invention manufactured independently according to the above-mentioned "valuable document substrate 3".

[0071] The produced value-document substrates are individually subjected to a soiling treatment and then analyzed by means of an analyzer or a vibrating screen. In this process, the brightness value (ΔL value) of the value-document substrate is measured in each case.

[0072] Figure 1 The percentage biomass content of the antifouling layer determined according to ASTM D6866, method B is plotted against the degree of soiling as a difference in brightness ΔL determined by a spectrophotometer (ELREPHO 450X), wherein nine value-document substrates were measured after soiling treatment.

[0073] Figure 1 Four quadrants are shown:

[0074] - upper right quadrant: measurement points for two value-document substrates according to the invention which were produced independently of one another according to the above-described "value-document substrate 1",

[0075] - upper left quadrant: measurement points for two value-document substrates according to the invention which were produced independently of one another according to the above-described "value-document substrate 2",

[0076] - lower left quadrant: measurement points for three value-document substrates not according to the invention, which were produced independently of one another according to the above-described "value-document substrate 4",

[0077] Lower right quadrant: measurement points for two value-document substrates not according to the invention which were produced independently of one another according to the above-described "Value-document substrate 3".

Claims

1. A valuable document substrate, comprising a fiber substrate body, wherein the fiber substrate body is provided with an antifouling layer on at least one main surface thereof, characterized in that: The antifouling layer can be obtained from a formulation essentially based on sustainable raw materials and has a biomass percentage content in the range of 35 to 100 which can be determined according to ASTM D6866, method B, and when performing a soiling test, the degree of soiling of the valuable document substrate, expressed as a difference in brightness ΔL, is in the range of 0 to 40, which can be determined by a spectrophotometer.

2. The valuable document substrate according to claim 1, wherein: The antifouling layer has a biomass percentage content in the range of 35-60, which can be determined according to ASTM D6866, method B, and when carrying out a soiling test, the degree of soiling of the valuable document substrate, expressed as the difference in brightness ΔL, is in the range of 0 to 30, preferably 0 to 15, which can be determined by a spectrophotometer.

3. The valuable document substrate according to claim 1 or 2, wherein: The antifouling layer comprises a polyurethane and / or acrylate based adhesive.

4. The valuable document substrate according to claim 1, 2 or 3, wherein: The fiber substrate body has a wet strength agent based on polyamide-epichlorohydrin (PAAE) resin and / or a dry strength agent based on carboxymethylcellulose and / or styrene-butadiene and / or a surface sizing agent based on polyvinyl alcohol.

5. The value-document substrate according to any one of claims 1 to 4, wherein: The antifouling layer additionally contains biocidal additives, in particular fungicidal, bactericidal and / or virucidal additives.

6. The valuable document substrate according to any one of claims 1 to 5, wherein: The fiber matrix body comprises natural fibers, wherein the natural fibers are obtained from plants selected from flax, cellulose, sisal or a mixture of two or more of the above plants.

7. The valuable document substrate according to any one of claims 1 to 6, wherein: The fiber matrix body comprises bio-based plant polymer fibers, wherein the bio-based plant polymer fibers are bio-based polyamide fibers, tencel fibers, thermoplastic polyurethane fibers, castor fibers, polylactic acid fibers and / or protein fibers, wherein the protein fibers are especially obtained from corn, peanuts, milk and / or soybeans.

8. The value-document substrate according to any one of claims 1 to 7, wherein: Antifouling layers are respectively provided on both main surfaces of the fiber base material.

9. The value-document substrate according to any one of claims 1 to 5, wherein: The fiber matrix body is biodegradable and based on sustainable fibers, wherein the sustainable fibers are in particular selected from natural fibers, regenerated cellulose fibers, bio-based plant polymer fibers, bio-based animal polymer fibers or a mixture of two or more of the above components.

10. The value-document substrate according to any one of claims 1 to 9, wherein: The fiber substrate body is a multi-layer fiber substrate body having a polymer layer / paper substrate / polymer layer structure or a paper substrate / polymer layer / paper substrate structure, wherein the polymer layer is biodegradable and is particularly selected from cellulose, polybutylene terephthalate (BTA copolyester), polylactic acid (PLA), particularly biaxial polylactic acid, polyhydroxybutyric acid (PHB), or a mixture of two or more of the above components.

11. The value-document substrate according to any one of claims 1 to 10, wherein: The value-document substrate has a security thread and / or a security strip and / or a security patch based on recycled materials or biomaterials and / or hybrid fibers based on natural fibers.

12. The value-document substrate according to claim 1, wherein: The valuable document substrate is a banknote.

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