DE102013007998A1 - A value document substrate, value document and method for producing a value document - Google Patents

Abstract

The invention relates to a substrate for the production of documents of value, in particular bank notes, comprising a substrate core with at least two plastic layers arranged one above the other, the substrate having a layer that reflects IR radiation on at least one of its two main surfaces.

Description

The invention relates to a substrate for producing value documents, in particular banknotes, to a value document which has such a substrate and to a method for producing a value document.

For the purposes of the present invention, "value documents" are understood to mean, for example, banknotes, shares, bonds, certificates, vouchers, checks, lottery tickets, high-quality admission tickets, passports, identity cards, credit cards and other flat valuables. Such valuables can also be packaging for possibly high-quality products. The term "value document" in the context of the present invention also includes precursors of said value documents, which, for example, are not yet fit for circulation.

To produce such value documents, in particular banknotes, a paper-based substrate is often used. Paper substrates are made of fibrous material, preferably cotton fibers. For the purposes of the present invention, "paper" means any type of paper or paper-like material (or nonwovens). In addition to paper made of cotton or cellulose (or polysaccharide), "paper" in the context of the present application is also understood as meaning substrates which contain fibers of an artificial polymer material (for example polyethylene terephthalate, polyethylene, polyamide). A paper-like material containing 100% plastic fibers, z. B. the nonwoven fabric with the trade name "Tyvek".

In the quest for security papers with tear resistance and higher resistance to pollution was in the WO 98/15418 proposed to make a banknote completely from a plastic substrate. In the recent past, multilayer plastic film substrates have been developed for making value documents consisting of two or three hot laminated LLDPE / BOPP / LLDPE films (LLDPE = linear low density polyethylene, BOPP = biaxially oriented polypropylene). A layer structure consisting of two such hot-laminated films therefore has the layer sequence LLDPE / BOPP / LLDPE / LLDPE / BOPP / LLDPE. In order to combine the advantages of paper substrates with those of film substrates, multi-layer substrates, so-called hybrid substrates, have been proposed in the prior art. The WO 2004/028825 z. B. describes a layer structure in which a paper layer on both sides with foil, preferably over the entire surface, is covered.

Foil composite substrates with a paper core tend to blister on sudden and intense heat. Blistering occurs, for example, when the composite substrate is abruptly heated with an iron (i.e., at a temperature above 140 ° C) or with a lighter. This is attributed to a sudden evaporation of moisture in the substrate.

Single or multilayer plastic film substrates, the z. B. based on polypropylene or polyethylene show under these conditions a strong format change, or are destroyed by shrinkage.

The invention has for its object to provide a value document substrate with increased stability to heat.

The invention is in particular the object of providing a value document substrate with increased security against counterfeiting.

A further object of the invention is to provide a method for producing a value document that is improved over the prior art.

These objects are achieved by the feature combinations defined in the main claims. Preferred embodiments are subject of the dependent claims.

Summary of the invention

• 1. (first aspect) substrate for producing documents of value, in particular banknotes, comprising a substrate core having at least two superimposed plastic layers, wherein the substrate has at least on one of its two major surfaces of an IR radiation-reflecting layer.
• 2. (preferred) Substrate according to paragraph 1, wherein the IR radiation-reflecting layer has IR radiation-reflecting pigments.
• 3. (preferred) Substrate according to paragraph 2, wherein the pigments each have an IR radiation-reflecting core and a white coating.
• 4. (preferred) The substrate of paragraph 3, wherein the IR-reflective core is based on a metal selected from the group consisting of aluminum, copper, zinc, iron, silver, and alloys of one or more of the foregoing.
• 5. (preferred) substrate according to paragraph 3 or 4, wherein the white coating is based on a compound selected from the group consisting of titanium dioxide, zinc oxide, magnesium oxide, zinc sulfide, calcium fluoride, lithium fluoride, sodium fluoride, potassium fluoride, calcium carbonate, lithopone, magnesium carbonate, barium sulfate, Barium titanate and barium ferrite, is selected.
• 6. (preferred) Substrate according to any one of paragraphs 1 to 5, wherein the IR radiation-reflecting layer in the form of a mark, in particular in the form of patterns, letters, numbers or images, is provided.
• 7. (preferred) The substrate according to any one of paragraphs 1 to 6, wherein the IR radiation-reflecting layer has regions with different levels of IR radiation reflectance.
• 8. (preferred) Substrate according to any one of paragraphs 1 to 5, wherein the IR radiation-reflecting layer is partially provided with an IR radiation-absorbing layer.
• 9. (preferred) Substrate according to paragraph 8, wherein the IR radiation absorbing layer in the form of a mark, in particular in the form of patterns, letters, numbers or images, is provided.
• 10. (preferred) The substrate according to any one of paragraphs 1 to 5, wherein the substrate core has a film-like security element, namely a security strip, a security thread or a patch-shaped security element, and the IR radiation-reflecting layer over its entire surface on at least one of the two main surfaces of the Substrate is formed.
• 11. (preferred) The substrate according to any one of paragraphs 1 to 5, wherein the substrate core has a foil-like security element, namely a security strip, a security thread or a patch-shaped security element, and the IR radiation-reflecting layer on part of at least one of the two main surfaces of the Substrate is formed and covers the film-like security element.
• 12. (preferred) Substrate according to any one of paragraphs 1 to 11, wherein the at least two superimposed plastic layers of the substrate core each polyolefin, which independently z. From the group consisting of polyethylene, polypropylene, low density polyethylene (LDPE), linear low density polyethylene (LLDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), and biaxially oriented polypropylene (BOPP) ,
• 13. (preferred) Substrate according to any one of paragraphs 1 to 11, wherein the substrate core has three superimposed plastic layers, for. B. two PET layers with an interposed embedded layer of biaxially oriented polypropylene (BOPP), or two superimposed plastic layers, for. B. PET layers, with an interposed embedded paper layer having.
• 14. (preferred) Substrate according to one of the paragraphs 1 to 13, wherein the IR radiation-reflecting layer over the entire surface or substantially the entire surface is formed on at least one of the two main surfaces of the substrate.
• 15. (preferred) The substrate of claim 14, wherein the IR radiation reflective layer is adapted to improve the stability of the substrate to heat.
• 16. (Second aspect) Value document, in particular a banknote, which has a substrate according to paragraphs 1 to 15.
• 17. (Third aspect) A method of producing a value document comprising printing on a substrate of paragraph 14 with ink and treating the printed substrate with IR radiation.

Detailed description of the invention

IR radiation reflecting layers that can be used for the substrate according to the invention are known in the art and z. B. commercially available from the company ECKART under the trade name IReflex ^® . Such layers can z. B. be applied by printing on the substrate. For example, in the EP 1 963 440 B1 described, white, IR radiation reflective pigments. To produce such a pigment, an IR-reflecting core is coated substantially uniformly with a substance which covers in the optical wavelength range and is substantially IR-transparent. The IR-reflecting core is a particulate, preferably spherical or platelet-shaped, substrate. It is preferred that the substrate has a platelet-like shape, because in this form, the largest IR reflection is given at the same time the lowest material consumption. The coating preferably has essentially IR-transparent pigment particles (or white pigments) and a matrix material. The substantially IR-transparent pigment particles may be fixed on the surface of the IR-reflecting core by these z. B. in and / or on an optically transparent matrix and / or are attached. The matrix preferably envelops the core uniformly. Due to the uniform coating of the IR-reflecting core with opaque in the optical wavelength range and thereby largely IR-transparent pigment-like particles receives the IR radiation-reflecting pigment overall a largely white appearance. The resulting from the IR-reflecting core optical effect is largely suppressed. Due to the broad IR transparency of the pigmented particles, the IR reflectivity of the core is not significantly affected. The white pigments preferably have an average primary grain size of from 180 to 400 nm, more preferably from 250 to 350 nm and particularly preferably from 270 to 330 nm. B. from the group consisting of titanium dioxide, zinc oxide, magnesium oxide, zinc sulfide, calcium fluoride, lithium fluoride, sodium fluoride, potassium fluoride, calcium carbonate, lithopone, Magnesium carbonate, barium sulfate, barium titanate and barium ferrite and mixtures thereof are selected. The matrix is preferably a colorless matrix. It preferably comprises or consists of metal oxides and / or organic polymers. Suitable metal oxides are, for. Example, titanium dioxide, silica, alumina / hydroxide, boron oxide / hydroxide, zirconia or mixtures thereof. Silica is particularly preferred. As organic polymers, those are preferably used which are also used as binders in paints, emulsion paints or printing inks. Examples of these are polyurethanes, polyesters, polyacrylates and / or polymethacrylates.

The IR-reflecting core used is preferably metal powder and / or platelet-shaped metal pigments and / or suitable pearlescent pigments. Platelet-shaped metal pigments are particularly preferred in view of their high IR reflection. It is preferred that the IR-reflective core is based on a metal selected from the group consisting of aluminum, copper, zinc, iron, silver, and alloys of one or more of the foregoing elements. The dimensions of the length and width of the platelet-shaped pigments, preferably metal pigments or metallic effect pigments, are preferably between 3 and 200 .mu.m, more preferably between 12 and 90 .mu.m, even more preferably between 20 and 75 .mu.m and particularly preferably between 40 and 70 .mu.m. The average thickness of the platelet-shaped pigments, preferably metal pigments or metallic effect pigments, is preferably between 0.04 and 4 μm, more preferably between 0.1 and 3 μm and particularly preferably between 0.3 and 2 μm.

The substrate according to the invention can be configured in particular according to one of the following advantageous embodiments. All variants are of course combinable.

1st embodiment

Embodiment of the IR radiation-reflecting layer in the form of a visually invisible IR coding or in the form of an invisible IR motif print. For this purpose, the IR radiation-reflecting layer, in particular in the form of a one-dimensional or two-dimensional barcode or in the form of a mark, for. In the form of patterns, letters, numbers or images. In particular, the IR radiation-reflecting layer can have regions with differently high IR radiation reflectivity. These areas can be visualized by means of an IR radiation source and a thermal imaging camera based on their different levels of IR reflection or IR intensity in the form of a gray scale.

2nd embodiment

Visually invisible IR coding or invisible IR motif printing can also be generated in alternative ways, as described below. For this purpose, the IR radiation-reflecting layer is provided as a flat layer and partially provided with an IR radiation absorbing layer. In this case, the IR radiation-reflecting layer can be present as a full-surface, the entire substrate covering layer. Furthermore, the IR radiation-reflecting layer can be present as a partial, partially covering the substrate layer. The IR-absorbing layer provided above the IR radiation can be used in particular in the form of a mark, for. In the form of patterns, letters, numbers or images. More particularly, the IR radiation absorbing layer may have regions of different levels of IR radiation absorption.

IR-absorbing inks for producing the IR-radiation absorbing layer, which are transparent in the visible wavelength range, are for. B. in the EP 1 790 701 A1 described. The IR-absorbing component is in particular a compound having a transition element selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni and Cu. The transition element may more preferably be an ion from the group of ions consisting of Ti ³⁺ , VO ²⁺ , Cr ⁵⁺ , Fe ²⁺ , Ni ²⁺ , Co ²⁺ and Cu ²⁺ . The IR-absorbing component containing the IR-absorbing transition element or the IR-absorbing transition element ions, in particular in the form of a glass, for. B. in the form of a phosphate and / or fluoride-containing glass, in which a coordination of the transition element or the transition element ions to the phosphate and / or fluoride anions is present in the glass. Furthermore, the infrared-absorbing component containing the IR-absorbing transition element ion or the IR-absorbing transition element ions may be z. For example, a crystalline compound consisting of one or more cations and one or more anions act. The anion may in particular consist of the group consisting of phosphate (PO ₄ ^3- ), hydrogen phosphate (HPO ₄ ^2- ), pyrophosphate (P ₂ O ₇ ^4- ), metaphosphate (P ₃ O ₉ ^3- ), polyphosphate, silicate ( SiO ₄ ^4- ), the condensed polysilicates, titanate (TiO ₃ ^2- ), the condensed polytitanates, vanadate (VO ₄ ^3- ), the condensed polyvanadates, molybdate (MoO ₄ ^2- ), the condensed Polymolybdaten, tungstate (WO ₄ ^2- ), the condensed polytungstate, fluoride (F ^- ), oxide (O ^2- ), and hydroxide (OH ^- ). In particular, it is preferred that the infrared-absorbing component is selected from the group of compounds consisting of copper (II) fluoride (CuF ₂ ), Copper hydroxide fluoride (CuFOH), copper hydroxide (Cu (OH) ₂ ), copper phosphate (Cu ₃ (PO ₄ ) ₂ .2H ₂ O), anhydrous copper phosphate (Cu ₃ (PO ₄ ) ₂ ), the basic copper (II) phosphates Cu ₂ PO ₄ (OH) (libethenitol), Cu ₃ (PO ₄ ) (OH) ₃ (cornetite), Cu ₅ (PO ₄ ) ₃ (OH) ₄ (pseudomalachite), CuAl ₆ (PO ₄ ) ₄ (OH) ₈ · 5H ₂ O (turquoise), copper (II) pyrophosphate (Cu ₂ (P ₂ O ₇ · 3H ₂ O), anhydrous copper (II) pyrophosphate (Cu ₂ (P ₂ O ₇ )), copper (II) metaphosphate (Cu ₃ (P ₃ O _{9) 2),} iron (II) fluoride (FeF ₂ * 4H ₂ O), anhydrous iron (II) fluoride (FeF _2), iron (II) phosphate (Fe ₃ (PO ₄ ) ₂ · 8H ₂ O, Vivianit), lithium iron (II) phosphate (LiFePO ₄ , triphylite), sodium iron (II) phosphate (NaFePO ₄ , Maricit), iron (II) silicates (Fe ₂ SiO ₄ , Fayalite, Fe _x Mg _2-x SiO ₄ , olivine), iron (II) carbonate (FeCo ₃ , ankerite, siderite), nickel (II) phosphate (Ni ₃ (PO ₄ ) ₂ .8H ₂ O), Titanium (III) metaphosphate (Ti (P ₃ O ₉ )), Ca ₂ Fe (PO ₄ ) ₂ .4H ₂ O (anapait) and MgFe (PO ₄ ) F (Wagnerite) The infrared-absorbing component may further be an IR-absorbing transition element atom or ion bonded to a component of the polymer binder of the ink. The polymer binder of the printing ink may in particular contain specific binding sites for transition element ^ions , preferably for Cu ²⁺ and / or for Fe ²⁺ . The binding sites may be, in particular, phosphate groups which are crosslinked into a polymer main chain or grafted onto a polymer main chain. Preferably, the infrared-absorbing component is an IR-absorbing complex of a transition element atom or ion and a binding site contained in the polymer, preferably an organic thiourea-copper (II) complex dissolved in the binder.

3rd embodiment

Providing the IR radiation reflective layer such that it has regions of different high IR radiation reflectance. In this case, the IR radiation-reflecting layer can be present as a full-surface, the entire substrate covering layer. Furthermore, the IR radiation-reflecting layer can be present as a partial, partially covering the substrate layer. This embodiment is particularly suitable for multicolor or gray scale visualization by thermography and sensory authentication in banknote processing machines.

4th embodiment

The IR radiation-reflecting layer is formed over the entire surface or essentially over its entire area on at least one of the two main surfaces of the substrate and is suitable for improving the stability of the substrate against sudden high heat exposure.

Multilayer substrates, which have a substrate core with at least two plastic layers arranged one above the other, can be split (for example as part of a counterfeit attack) at elevated temperature into two equivalent or approximately equivalent substrate halves. In the case of a polymer banknote with the layer sequence LLDPE / BOPP / LLDPE / LLDPE / BOPP / LLDPE, the thermal lamination between the two central, adjacent LLDPE layers is the weak point for the cleavage. In a PET / BOPP / PET substrate, consisting of two PET layers with a central layer of biaxially oriented polypropylene (BOPP), wherein between the central BOPP layer and the two outer PET layers in each case a laminating adhesive layer is arranged forms the Lamination the weak spot for the split.

The risk of splitting due to heat also exists in the WO 2004/028825 Layer structure described in which a paper layer on both sides with foil, preferably over the entire surface, covered.

The two substrate halves, consisting of front and back, differ in extreme cases only by the imprint and the security features on the respective side. Therefore, it would be possible to combine an original page with a spoofed page and to bring the value document thus obtained into circulation.

5th embodiment

The substrate core is provided in such a way that it has a foil-like security element, namely a security strip, a security thread or a patch-shaped security element, and the IR radiation-reflecting layer is either a) formed on at least one of the two main surfaces of the substrate, or b) the IR radiation-reflecting layer is formed over part of the area on at least one of the two main surfaces of the substrate and covers the film-like security element.

This variant solves z. B. the problem of blistering in multilayer plastic film substrates or film / paper / film substrates with embedded security thread. Blistering in the filament region occurs especially at too high process temperatures and can be attributed to a weakness of the heat-seal adhesive, and in part to a weakness in the layer structure of the thread.

6th embodiment

The IR radiation-reflecting layer is formed over the entire surface or essentially over the entire area on at least one of the two main surfaces of the substrate and thus improves the drying of the subsequent color layers or lacquer layers by means of thermal radiation. The improved drying is based on the favoring of the heat input through the reflection. The IR-radiation-reflecting layer may be formed in particular in the form of a dye-accepting layer or primer layer.

7th embodiment

The IR radiation-reflecting layer is formed over the entire surface or essentially over the whole area on at least one of the two main surfaces of the substrate and thus improves the opacity of the plastic layer-based substrate. The increase in opacity is due in particular to the metallic core of the IR radiation-reflecting pigment. The IR-radiation-reflecting layer may be formed in particular in the form of a dye-accepting layer or primer layer. The use of such an ink-receptive layer having IR-reflecting white pigments ensures increased opacity and, at the same time, sufficient transmission in the UV range, in particular in the case of a film / paper / film substrate.

The invention will be described below in connection with the 1 to 4 described with reference to embodiments.

In the figures show

1 the structure of a value document substrate according to a first embodiment,

2 the value document substrate according to the first embodiment when viewed with an IR irradiation source and a thermal imaging camera;

3 the cross-sectional view of a value document substrate according to a second embodiment; and

4 the cross-sectional view of a value document substrate according to a third embodiment.

<Embodiment 1>

1 shows a value document substrate 1 , in this case, a banknote substrate, which appears completely white when viewed with the naked eye, ie no motives are recognizable to the viewer.

The substrate 1 is equipped with various security features that reflect IR radiation to varying degrees. The extent of IR reflection depends on the proportion or concentration of the IR radiation reflecting pigments present in the respective IR radiation reflecting layer.

For better understanding, the IR reflectance of the different subject areas will be described in the following description with the terms "100% IR Reflecting Pigment Area", "75% IR Reflective Pigment Area", "50% IR Reflective Pigment Area "And" area with 25% IR-reflective pigment "circumscribed. The percentages are not to be understood as absolute values in terms of "weight percent" or the like, but merely indicate the IR reflectance of the individual regions relative to each other.

The printed value "50" with the reference number 2 represents a range with 100% IR-reflecting pigment. The printed value "50" with the reference number 3 shows a region with 50% IR-reflective pigment.

The reference number 4 denotes an IR-reflecting field, which is additionally provided with an IR-absorbing printing with the typeface "50 50 50".

The value document substrate 1 also contains fields 5 . 6 . 7 and 8th with different levels of IR reflectance (field 5 shows a region with 100% IR-reflective pigment; field 6 shows a region with 75% IR-reflective pigment; field 7 shows a region with 50% IR-reflective pigment; field 8th shows a region with 25% IR-reflecting pigment).

With the reference number 9 the background of the value document substrate is given with 0% IR-reflecting pigment.

In the present embodiment, none of the reference numbers 2 to 9 Subject areas has color components that are visible when viewed in pure daylight. In other words, the value document substrate 1 When viewed with the naked eye, it appears completely white.

2 schematically shows the appearance of the value document substrate 1 when viewed with an IR radiation source and a thermal imaging camera.

The areas with the reference numbers 5 . 6 . 7 . 8th and 9 are recognizable to the viewer distinguishable in the form of a gray scale, the Area 5 the brightest appears and the area 9 appears darkest.

The IR-absorbing ink typeface "50 50 50" is rich in contrast in the IR-reflecting field 4 to recognize.

In addition, the area formed with 100% IR reflective pigment produces 2 and the region formed with 50% IR reflective pigment 3 the value "50" in the form of an interesting text effect, in which the viewer the area 2 as a bright foreground and the area 3 perceives as a dark shadow.

The substrate may be, for example, a film / paper / film composite in which an IR-reflective white print is integrated in a white ink accepting layer. In this case, regions with different IR reflectance or different IR intensity can be generated by selecting a different pigmentation with IR-reflecting pigment depending on the region.

The IR reflectance can also be adjusted by overprinting an IR-reflective area with IR-absorbing ink.

<Embodiment 2>

3 shows a cross-sectional view of a value document substrate 10 according to a second embodiment.

The substrate core comprises a central paper layer 11 , on both sides, each with a slide 12 is coated. Such a multilayered substrate is known from WO 2004/028825 A2 known.

One on the slide 12 applied primer layer 13 partially has an IR radiation reflecting layer 16 on. The IR-reflecting layer 16 can z. B. by printing a color with the from the EP 1 963 440 B1 known IR radiation reflecting pigments are generated.

Above the primer layer 13 and the IR-reflecting layer 16 there is a paint acceptance layer 14 that with a print layer 15 is provided. The print layer 15 may be formed in the form of several sub-layers, for. B. in the form of a background pressure, which is at least partially provided with a gravure printing. The print layer 15 can optionally have a protective coating.

In the present example, the print layer 15 in the area of the IR-reflecting layer 16 partly an IR radiation absorbing printing layer 17 on.

Those emanating from an IR radiation source and onto the value document substrate 10 incident IR radiation 18 gets from the substrate 10 partially absorbed, partially diffusely reflected, and partially through the substrate (see the reference numeral 19 designated IR radiation).

The on the IR-reflective layer 16 incident IR radiation is emitted from the layer 16 reflected, preferably directionally reflected, wherein the reflected IR radiation partly from that in the region of the layer 16 formed IR radiation absorbing printing layer 17 is absorbed (see the reference number 20 designated IR radiation).

The IR radiation absorbed by the substrate, the IR radiation transmitted by the substrate and the reflected IR radiation result when the value document substrate is viewed 10 with a thermal imaging camera to a visually recognizable subject.

The central paper layer 11 the substrate core may alternatively be a plastic layer or a foil. Furthermore, the IR radiation reflecting layer 16 alternatively or additionally in another layer, e.g. B. in the ink receiving layer 14 be formed.

<Embodiment 3>

4 shows a cross-sectional view of a value document substrate 23 according to a third embodiment. The value document substrate described in this example has improved color drying and improved protection of the layer composite and the security thread embedded therein as a result of the reflected IR radiation.

The substrate core comprises a central paper layer 11 , on both sides, each with a slide 12 is coated. In the paper layer 11 was before the lamination of the films 12 a security thread 22 embedded.

Above a slide 12 there is a full-surface IR radiation-reflecting primer layer or ink receiving layer 21 , Such a layer can be produced by adding conventional compositions for the preparation of primer layers or ink receiving layers in addition to those from the EP 1963 440 B1 mixed known IR radiation reflecting pigments. Alternatively, such a layer can be prepared by subjecting a conventional primer layer or ink receiving layer in a subsequent step over the entire surface with a printing ink, the the from the EP 1 963 440 B1 contains known IR radiation reflecting pigments printed.

Above a possibly existing further ink receiving layer 14 there is a print layer 15 , The print layer 15 may be formed in the form of several sub-layers, for. B. in the form of a background pressure, which is at least partially provided with a gravure printing. The print layer 15 can optionally have a protective coating.

Those emanating from an IR radiation source and onto the value document substrate 23 incident IR radiation 18 is reflected by the full-surface IR radiation reflective layer 21 reflected, preferably predominantly directionally reflected (see the reference number 20 designated IR radiation).

Temperature-sensitive substrates, the z. B. based on polypropylene or polyethylene layers, or such layers containing composite substrates may during their manufacturing process by the IR-reflective layer 21 be protected from critical heat.

Furthermore, by the IR-reflective layer 21 avoided that in the security thread 22 too high temperatures occur. In this way, damage in the thread area, z. B. due to a weakening of the heat-seal adhesive or damage to the layer structure of the thread can be avoided.

In addition, the leads from the IR-reflective layer 21 reflected heat radiation to an improved drying of the subsequent paint and varnish layers, because the heat input is promoted by the reflection.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 98/15418 [0004]
• WO 2004/028825 [0004, 0020]
• EP 1963440 B1 [0011, 0048, 0057, 0057]
• EP 1790701 A1 [0016]
• WO 2004/028825 A2 [0047]

Claims (17)

Substrate for the production of documents of value, in particular banknotes, comprising a substrate core with at least two superimposed plastic layers, wherein the substrate has at least on one of its two major surfaces an IR radiation-reflecting layer. The substrate of claim 1, wherein the IR radiation reflective layer comprises IR radiation reflective pigments. The substrate of claim 2, wherein the pigments each have an IR radiation reflective core and a white coating. The substrate of claim 3, wherein the IR-reflective core is based on a metal selected from the group consisting of aluminum, copper, zinc, iron, silver, and alloys of one or more of the foregoing. The substrate of claim 3 or 4, wherein the white coating is based on a compound selected from the group consisting of titanium dioxide, zinc oxide, magnesium oxide, zinc sulfide, calcium fluoride, lithium fluoride, sodium fluoride, potassium fluoride, calcium carbonate, lithopone, magnesium carbonate, barium sulfate, barium titanate and barium ferrite is. Substrate according to one of claims 1 to 5, wherein the IR radiation-reflecting layer in the form of a mark, in particular in the form of patterns, letters, numbers or images, is provided. A substrate according to any one of claims 1 to 6, wherein the IR radiation reflecting layer has regions of different high IR radiation reflectance. A substrate according to any one of claims 1 to 5, wherein the IR radiation reflective layer is partially provided with an IR radiation absorbing layer. Substrate according to claim 8, wherein the IR radiation absorbing layer is provided in the form of a mark, in particular in the form of patterns, letters, numbers or images. Substrate according to one of claims 1 to 5, wherein the substrate core comprises a film-like security element, namely a security strip, a security thread or a patch-shaped security element, and the IR radiation-reflecting layer is formed over the entire area on at least one of the two main surfaces of the substrate. Substrate according to one of claims 1 to 5, wherein the substrate core has a foil-like security element, namely a security strip, a security thread or a patch-shaped security element, and the IR radiation-reflecting layer is formed on at least one of the two main surfaces of the substrate covering foil-like security element. Substrate according to one of claims 1 to 11, wherein the at least two superimposed plastic layers of the substrate core each polyolefin, which independently of each other z. From the group consisting of polyethylene, polypropylene, low density polyethylene (LDPE), linear low density polyethylene (LLDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), and biaxially oriented polypropylene (BOPP) , Substrate according to one of claims 1 to 11, wherein the substrate core has three superimposed plastic layers, for. B. two PET layers with an interposed embedded layer of biaxially oriented polypropylene (BOPP), or two superimposed plastic layers, for. B. PET layers, with an interposed embedded paper layer having. Substrate according to one of claims 1 to 13, wherein the IR radiation-reflecting layer over the entire surface or substantially over the entire surface is formed on at least one of the two main surfaces of the substrate. The substrate of claim 14, wherein the IR radiation reflective layer is adapted to improve the stability of the substrate to heat. Value document, in particular a banknote, which has a substrate according to one of claims 1 to 15. A method of making a value document comprising printing on a substrate according to claim 14 with ink and treating the printed substrate with IR radiation.

Images