DE102011120063A1 - Security paper and value document available therefrom - Google Patents

Abstract

The invention relates to a security paper for the production of value documents, such as banknotes, passports, identity documents or the like, having a flat substrate, which is provided on at least one surface with at least one counterfeit protection means, wherein the counterfeit protection means is based on a carrier film with opposite first and second major surfaces and the at least partially perceptible, the substrate opposite the first main surface of the carrier film has an optically variable security feature that forms a perceptible in the incident light first motif, and the counterfeit protection means and a counterfeit securing means surrounding partial surface of the substrate with a partial, not opaque , Optically variable overcoating of spaced, printed structural elements is provided, which forms a perceptible when viewed in incident light second motif.

Description

The invention relates to a security paper for the production of value documents, such as banknotes, passports, identity documents or the like, having a planar substrate, which is provided on a surface with an anti-counterfeiting security feature having an optically variable security feature. The invention further relates to a document of value with such a security paper.

Security documents, such as banknotes, stocks, bonds, certificates, vouchers, checks, high-quality admission tickets, but also other forgery-prone papers, such as passports or other identity documents, are often provided with counterfeit securities for verification, which allow a verification of the authenticity of the value document and at the same time serve as protection against unauthorized reproduction. The tamper-evident means may for example be in the form of a security thread completely or partially embedded in a banknote or in the form of a security strip or patch applied to the banknote.

In recent years, counterfeit security devices, in particular security threads, have established themselves with optically variable security features on the banknote market. Optically variable security features give the viewer a different image impression under different viewing angles. The security features may be present in particular in the form of diffraction-optically effective microstructures or nanostructures, such as in the case of conventional embossed holograms or other hologram-like diffraction structures (see, for example, the publications EP 0 330 733 A1 or EP 0 064 067 A1 ).

It is also known to use lens systems as security features. For example, in the document EP 0 238 043 A2 or in the DE 36 09 090 A1 a security thread of a transparent material described on the surface of a grid of several parallel cylindrical lenses is imprinted. The thickness of the security thread is chosen so that it corresponds approximately to the focal length of the cylindrical lenses. On the opposite surface of a printed image is applied register accurate, the print image is designed taking into account the optical properties of the cylindrical lenses.

For some time, so-called moiré magnification arrangements are used as security features. Such a moiré magnification arrangement is in the document WO 2006/087138 A1 or in the DE 10 2005 028 162 A1 disclosed. That in the WO 2006/087138 A1 disclosed counterfeit protection means comprises at least a first and a second security feature. The first authenticity feature comprises a first arrangement with a plurality of focusing elements, which are present in a first grid, and a second arrangement with a multiplicity of microscopic structures, which are present in a second grid. The first and second arrays are arranged one another such that the microscopic structures of the second array are magnified as viewed through the focussing elements of the first array. Such a magnification effect is also called moiré magnification. In short, moiré magnification thereafter refers to a phenomenon that occurs when viewing a raster of identical image objects through a lenticular of approximately the same pitch. As with any pair of similar rasters, this results in a Mairé pattern, in which case each of the moiré fringes appears in the form of an enlarged and rotated image of the repeated elements of the raster.

It is also known that optically variable security features based on periodic or aperiodic sawtooth gratings (see, for example, US Pat WO 2011/066991 A2 ) or on the basis of micro hollow mirror arrays (see, for example, the DE 10 2009 035 361 A1 ).

Securities may be provided with a dirt-repelling protective coating to extend their service life and fitness. For example, in the document EP 0 256 170 B2 proposed to provide printed bills with a protective layer, which contains cellulose ester or cellulose ether to a greater extent and to a lesser extent micro-wax and which is applied over the entire surface of the bills. The micronized wax is thereby dispersed by kneading or mixing with oil, a colorant or a mixture thereof. The sheets freshly printed with the protective layer can be easily stacked without discoloring black color from a sheet to the underlying sheet.

Optically variable counterfeit protection means, in particular security elements with a micro-optical representation arrangement with microstructures and microimage elements for enlarged imaging of the microstructures, z. As micro lens systems or micro hollow mirror arrays can not be provided with a dirt-repellent protective layer due to a possible impairment of the optical effect. The partial application of a soil-repellent protective layer to a bill equipped with an optically variable counterfeit security device in such a way that the protective layer has a recess in the area of the counterfeiting protection means, it leads to disturbing dirt spots in the area of the recess.

Based on this, the object of the invention is to avoid the disadvantages of the prior art and, in particular, to provide a security paper with an optically variable counterfeit security device, which reveals, in circulation, an improved optical quality of the counterfeiting agent with regard to troublesome stains.

This object is achieved by the feature combinations defined in the independent claims. Further developments of the invention are the subject of the dependent claims.

Summary of the invention

A first aspect of the invention relates to a security paper for producing value documents, such as banknotes, passports, identification documents or the like, having a planar substrate which is provided on at least one surface with at least one counterfeit protection means, wherein
the anti-counterfeiting means is based on a carrier film with opposing first and second main surfaces and the observer at least partially perceptible, the substrate opposite the first main surface of the carrier film has an optically variable security feature that forms a perceptible in reflected light first motif, and
the anti-counterfeiting means and a partial surface of the substrate surrounding the anti-counterfeiting means are provided with a partial, non-opaque, optically variable overlay of spaced, printed structural elements forming a second motif perceptible in incident light.

The term overcoating used herein is to be understood as a printable coating, in particular a coating obtainable by means of screen printing or flexographic printing.

The optically variable security feature of the anti-counterfeiting agent can be applied in particular to microimage elements, for. B. micro lens systems or micro hollow mirror arrays, based on the enlarged image of microstructures. Furthermore, it is preferred that the partial, non-opaque, optically variable overpainting has a color-shift effect (or color flop) and / or brightness-shift effect (or brightness flop).

It is preferred that the partial, non-opaque, optically variable overcoating is based on effect pigments which are chosen in particular from pearlescent pigments or pigments prepared on the basis of liquid-crystalline polymers.

The spaced, printed structural elements of the partial, non-opaque, optically variable overcoat preferably have a percent area coverage of at most 70%, more preferably up to a maximum of 50%. As used herein, the term "percent area coverage" refers to the ratio of the area formed solely by the spaced apart printed features with respect to the total area formed by the spaced apart printed features and the intervening white areas and non-printed areas, respectively ,

The spaced, printed structural elements of the partial, non-opaque, optically variable overpainting can in particular form a dot matrix, line grid or a grid of image objects or alphanumeric characters.

It is preferred that the first motif formed by the optically variable security feature of the anti-counterfeiting means has identical, repeating first picture elements and the second motif formed by the partial, non-opaque, optically variable overpainting has identical, repeating second picture elements. In particular, it is preferred that the shape or appearance of the first picture elements match the shape or appearance of the second picture elements.

The anti-counterfeiting agent can be present in particular as a security strip, patch, or security thread, preferably as a window security thread.

It is preferred that the substrate is provided with a dirt-repellent lacquer, at least on its surface lying outside of the partial, non-opaque, optically variable overpainting.

In particular, the soil-repellent varnish may be based on (a) a physically drying, water-based dispersion varnish which cures by removal of the dispersing agent or (b) is based on a UV-crosslinking varnish.

It is particularly preferred that the soil-repellent paint is based on a physically drying, water-based dispersion paint which cures by removal of the dispersant and is an aqueous dispersion of a polyacrylic resin or a polyurethane resin.

Furthermore, it is preferred that the substrate is printed with characters or patterns, and the optionally present dirt-repellent paint is applied to the printed substrate and / or the optionally present dirt-repellent paint is printed.

A second aspect of the invention relates to a value document, such as a banknote, a passport, a passport document or the like, the security document having a security paper according to the first aspect of the invention.

Detailed description of the invention

The invention is based on the finding that contaminants in the region of an optically variable counterfeit protection means can be concealed or obscured by the application of a partial, non-opaque, optically variable overpainting. The overpainting is effectively the function of a camouflage painting, which ensures that z. B. incurred banknotes resulting dirt stains in the field of counterfeit security as such are no longer perceived. At the same time, the visibility of the optical effect of the counterfeiting protection agent is not particularly impaired by the overpainting, because the overpainting is not present over the entire surface but partially in the form of spaced, printed structural elements. In this way, the optically variable security feature of the anti-counterfeiting means, which is arranged below the partial overpainting, can be perceived at least in regions for the viewer. It is expedient to design the structural elements with respect to their dimensions in such a way that adjacent structural elements can be distinguished to the naked eye. It has been found that the spaced, printed structural elements of the partial, non-opaque, optically variable overcoating should preferably have a percentage area coverage of at most 70%, more preferably up to a maximum of 50%. In this way, the prone to contamination area of the anti-counterfeiting agent can be particularly well protected against contamination, without the perceptibility of the optically variable security feature of the anti-counterfeiting means is all too much affected.

The spaced, printed structural elements of the partial, non-opaque, optically variable overpainting can in particular form a dot matrix, line grid or a grid of image objects or alphanumeric characters. In the case of a line grid, it may be z. For example, it can be a family of parallel lines or a cross grid.

It has been shown that coatings suitable for overcoating, in particular for effect pigments, are suitable. Non-opaque, optically variable paints based on effect pigments are known in the prior art (see, for example, US Pat EP 1 391 318 B1 ). In particular, pearlescent pigments, metallic effect pigments, multilayered pigments with transparent or transparent and opaque layers, holographic pigments, BIOC1 and LCP pigments (LCP = Liquid Crystal Polymer) are understood as effect pigments.

It is particularly preferred overpainting based on effect pigments, wherein the effect pigments of pearlescent pigments or of LCP pigments are selected. Pearlescent pigments are commercially available, e.g. B. under the trade name Iriodin ^® Fa. Merck. Pigments based on liquid-crystalline polymers are known in the art (see, for example, US Pat WO 2008/000755 A1 ). It has been shown that by means of a partial, non-opaque, optically variable overpainting based on pearlescent pigments or LCP pigments, it is not only possible to mask soiling, but also to create aesthetically attractive motifs. The motif of the optically variable security feature of the anti-counterfeiting agent is superimposed on the motif which is produced by the special effect pigment overpainting. The viewer, who in verifying the counterfeit security agent, for. As a (window) security thread with a microlens or micro-concave security feature, fixed the relevant area of the security thread with the eye and tilted the security paper in a subsequent step, the dynamic motion effect of the security feature particularly impressive true because this addition of the superimposed by the overpainting color shift effect (or color flop) and / or brightness shift effect (or brightness flop) is superimposed.

The superimposition of the two optical effects described above can be increased with respect to the effectiveness on the viewer by having the first motif formed by the optically variable security feature of the anti-counterfeiting means identical, repeating first picture elements and that by the partial, non-opaque, optically variable Overpainting formed second motif has identical, repeating second picture elements and the shape or the appearance of the first picture elements with the shape or the appearance of the second picture elements match. Alternatively, the superposition of the two optical effects can be increased in an associative sense if the repeating first picture elements are different picture elements than the repeating second picture elements, but are in a meaningful relationship with each other (e.g. B. a microlens thread having as the optically variable motif first picture elements in the form of a sun and an overcoat, which has as the optically variable motif second picture elements in the form of a moon).

The overcoat can in particular contain one or more effect pigments. By using at least two different effect pigments special color and gloss effects can be achieved. Furthermore, blends of one or more effect pigments with organic and / or inorganic pigments are possible. By blending the color shift effects (or color flops) and / or brightness shift effects (or brightness flops) can be set specifically.

The partial, non-opaque, optically variable overcoating can be applied by flexographic printing or offset printing. The application can be made in the paper mill or in the printing house.

The anti-counterfeiting agent based on a carrier film may e.g. B. in the form of a security strip, a security thread or in the form of a label or patch. The optically variable security feature with which the counterfeit protection means is provided, z. For example, in the form of diffractive optical effective micro- or nanostructures, such as in the case of conventional embossed holograms or other hologram-like diffraction structures (see, for example, the publications EP 0 330 733 A1 or EP 0 064 067 A1 ). The security feature can be applied in particular to lens systems (see, for example, the publications EP 0 238 043 A2 and DE 36 09 090 A1 ) or microvoided mirror arrays (see, for example, the DE 10 2009 035 361 A1 ).

The forgery-proofing means can be visually recognizable to the observer completely or only partially. An example of an only partially visually recognizable counterfeit protection means is a window security thread (eg a microlens thread), which emerges in window areas on the surface of a banknote, while it is embedded in the intervening web areas inside the banknote (see eg. the 1 of the WO 2004/097112 A1 ).

For application-technical reasons, the partial, non-opaque, optically variable overpainting is not applied register-accurate above the counterfeit protection agent, but the paint also covers a part of the security paper substrate surrounding the counterfeit protection means and forms an edge region for the anti-counterfeiting agent (the phrase "die Counterfeiting agent surrounding partial surface "used herein is representative of the edge region). The anti-counterfeiting agent can be surrounded all around by the topcoat, such. In the case of a patch-shaped anti-counterfeiting device. In the case of a security thread or stripe extending from one edge of the bill to the opposite edge, the anti-counterfeiting agent is surrounded on two sides by the overpainting, i. H. the anti-counterfeiting means and two elongated, adjacent to the counterfeiting means partial surfaces of the substrate are provided with the overcoating.

The partial surface of the substrate surrounding the anti-counterfeiting agent, d. H. The edge region, in particular, may have a width of 1 to 25 mm, preferably 2 to 7 mm, measured from the outer edge of the counterfeit security device up to the outer edge of the adjacent partial surface of the substrate.

With regard to the extension of the service life and the fitness for circulation of the security paper, it is particularly advantageous to provide the security paper substrate with a conventional dirt-repellent lacquer on its surface lying outside the counterfeit security device, which has the partial, non-opaque, optically variable overcoating in the region where appropriate, the partial area of the substrate surrounding the counterfeit security agent may partially overlap. In particular, the soil-repellent lacquer can be based on a physically drying, water-based dispersion lacquer which hardens by removal of the dispersion medium (see, for example, the publications WO 00/00697 . EP 0 815 321 B1 and EP 1 338 430 A1 ), or based on a UV-crosslinking varnish, which optionally contains matting agents.

Suitable UV-crosslinking lacquer layers with high physical and chemical resistance are known in the art (see, for example, US Pat EP 1 595 029 B1 ). The UV-crosslinking, soil-repelling lacquer may in particular be a monomeric acrylate (mono-, di-, tri- and / or tetrameric acrylate) and optionally additives or processing aids, such as defoamers, dispersing agents, UV curing accelerators, viscosity modifiers, leveling agents and Stabilizers. The UV lacquer may further consist of an acrylate mixture, preference being given to an acrylate mixture obtained by reacting at least one intermediate molecular weight prepolymeric acrylate of, for example B. 500 to 2000 with the monomeric acrylate (mono-, di-, tri- and / or tetrameric acrylate), wherein the paint 100 parts by weight of the acrylate (calculated without additive or Processing aid) and 1 to 10 parts by weight of a UV initiator or UV initiator mixture or consists of these components. For UV curing z. B. UV rays in a range of 100 to 450 nm, preferably 100 to 200 nm, more preferably from 130 to 190 nm. The soil-repellent UV varnish can in particular on mixtures of mono- and / or difunctional monomeric acrylates, prepolymeren Acrylates, and based tri- and / or tetra-functional monomeric acrylates. As prepolymeric acrylates z. As polyester acrylates, urethane acrylates, acrylic acrylates and / or methacrylacrylates, oligoester acrylates, epoxy acrylates, and / or mixtures of two or more of these prepolymeric acrylates are used. It is preferred that the soil-repellent UV varnish has silicones and / or waxes to improve its soil-repelling properties. In addition to radically crosslinking UV lacquers, cationic crosslinking lacquer systems are also suitable. The soil-repelling UV varnish may be present on the substrate in particular at a coating weight of 0.5 to 3 g / m ² , preferably 1 to 2 g / m ² . This corresponds to about 1 to 2 g / m ^{2 of} the preferred range in the uncrosslinked state because UV systems are so-called "100% systems" (ie, 100% solids).

An example of a dirt-repellent UV varnish is listed below:

Composition 1:

UV lacquers "UV L50733" and "UV L50734" from Pröll in a mixing ratio of 3: 2. These are applied dry with a 9 cc / m ² roll in an application amount of about 1.8 g / m ² .

In particular, physically drying aqueous dispersions based on a polyacrylic resin and / or a polyurethane resin are preferred for forming the soil-repelling paint. The paint can be based in particular on a one-component polyurethane system or one-component polyacrylate system with pre-crosslinked polyurethane or polyacrylate. But it can also be used blocked polyurethane having chemically bonded to the polymer chains isocyanate groups. The isocyanate groups can be regenerated at elevated temperatures, which are generally used in the security printing process. Two-component polyurethane systems or polyacrylate systems crosslinkable by using multifunctional reagents such as melamine / formaldehyde precondensates may also be used. In general, the polyurethane may in particular be of the aliphatic polyester type and / or of the aliphatic polyether type. It is also possible to use aliphatic polycarbonate polyurethane. The polyacrylate can generally z. B. be of the aromatic type, such as a styrene / acrylic copolymer. Mixtures of a polyurethane and a polyacrylate may, for. B. in a weight ratio of 90:10 to 10:90, preferably 75:25 to 25:75 are used. The physically drying aqueous dispersions may contain additional ingredients such as catalysts, co-solvents, dispersing aids, defoamers, viscosity modifiers, extenders, fluorescent and / or iridescent additives and / or surfactants. A typical physically drying aqueous dispersion has z. Example, a polyurethane of the type of an aliphatic polyester or an aliphatic polyether having a polyurethane content of 2 to 70 wt .-%, preferably from 5 to 30 wt .-%, on.

The soil-repellent lacquer based on an aqueous dispersion can preferably be applied to the security paper by means of the flexographic printing process. The coating layer is expediently applied in a coating amount of 1 to 8 g / m ² . Examples of physically drying compositions of the soil-repellent paint are listed below:

Composition 2:

• 900 ml of aqueous dispersion of an acrylate ("Neocryl-AC 72" from Zeneca)
• 80 ml of water
• 20 ml crosslinker "CX 100" from Zeneca

Composition 3:

• 900 ml aqueous dispersion of an acrylate ("Primal I-545" from Rohm & Haas)
• 80 ml of water
• 20 ml zirconium carbonate Fa. Auer-Remy

Composition 4:

• 700 ml aqueous dispersion of an acrylate-styrene copolymer ("Glascol LS 26" from CIBA)
• 200 ml aqueous dispersion of a polyurethane ("U 400 N" from Alberdink Boley)
• 100 ml of water
• 20 ml crosslinker "CX 100" from Zeneca

According to a preferred embodiment, in the course of producing a value document, the security paper is printed with characters or patterns on the surface of the substrate which is located outside the counterfeit security device. Alternatively or additionally, after the application of the dirt-repellent paint, a printed image can be printed above the dirt-repellent paint.

With respect to the security paper substrate, there are no special restrictions. Banknote papers are typically made from fibers of annual plants, especially cotton fibers or pulp fibers, but papers which are at least partially made of plastic fibers, preferably polyamide fibers or polyester fibers, may also be used. More preferably, a cotton paper is used as a security paper substrate. The basis weight of the substrate varies depending on the application form. Typical basis weights are in the range of 50 g / m ² to 100 g / m ² , preferably in the range of 60 g / m ² to 90 g / m ² , more preferably about 70 g / m ² . For multi-layer substrates, the individual paper layers may consist of the same or different types of paper. For example, a paper layer may be a pure cotton paper, while another paper layer may comprise plastic fibers. Furthermore, as the security paper substrate and multilayer paper / foil composites can be used, such as a paper / foil / paper composite or a foil / paper / foil composite.

Also, there are no particular restrictions on the manner of manufacturing the security paper substrate. The production preferably takes place by means of a rotary screening machine.

Further exemplary embodiments and advantages of the invention are explained below with reference to the figures, in the representation of which a representation true to scale and proportion has been dispensed with in order to increase the clarity.

Show it:

1 a schematic representation of a security paper with embedded window security thread and glued patch-shaped security element;

2a the enlarged portion II in plan view, wherein the sweeping zone of the thread is schematically illustrated;

2 B the enlarged area II in plan view, wherein the expansion of the partial, non-opaque, optically variable overpainting is schematically illustrated; and

3 a schematic representation of the perceptible in the window areas of the thread first motif and the second motif formed by the overpainting.

1 shows a schematic representation of a security paper 1 That with an embedded window security thread 2 and a glued patch-shaped security element 3 is provided. The security paper 1 also has the denomination "100" in the form of a watermark. The window security thread 2 (in the present case, a microlens thread) and the security element 3 (In the present case, a micro-optical representation arrangement with microstructures and micro hollow mirror arrays for enlarged imaging of the microstructures) give the viewer a different image impression at different viewing angles. The dashed window security thread 2 occurs at the window areas 4 on the surface of the security paper 1 while standing at the intervening land areas inside the security paper 1 is embedded.

The patch-shaped security element 3 and the window security thread 2 are each provided with a partial, non opaque, optically variable overpainting. In the present example, the overpainting is based on Iriodin ^® -Perlglanzpigmenten and was in the flexographic printing in the areas 5 and II applied to the security paper. The overpainting is not register-accurate above the counterfeit protection 2 and 3 but overpainting also covers adjacent parts of the security paper substrate that contain the anti-counterfeiting agent 2 and 3 surrounded and, so to speak, edge areas for the counterfeit security 2 and 3 form.

The security paper 1 is at its outside the counterfeit 2 and 3 lying surface over the entire surface with a soil-repellent second paint provided, the partial, non-opaque, optically variable overcoating in the field of counterfeiting 2 and 3 partially overlapping surrounding partial surfaces of the substrate. In the present example, the dirt-repellent second paint is based on a physically drying aqueous dispersion paint applied by means of flexographic printing.

2a shows the enlarged section II of 1 in plan view. The window security thread 2 occurs at the window areas 4 on the surface of the security paper, while being embedded in the intervening land areas inside the security paper. In order to avoid unwanted thickening (and therefore poor flatness of the paper sheets) in stacked securities at the points of the security thread, the security thread is introduced into the paper during papermaking by means of the wobble technique known in the prior art. The term "wobble" here denotes a periodic variation of the security thread when embedding in the paper of several millimeters perpendicular to the thread direction, so that certain Wobble zones 6 within which the security thread comes to rest.

The window security thread 2 and a window security thread 2 surrounding partial surface of the substrate are with the above-described partial, non opaque, optically variable overcoating 7 provided (see 2 B ).

3 shows an example of this in the panes 41 of the thread perceptible first motif and that of the overpainting 71 formed second motif. The first motif contains the identical, repeating image elements "<". When the security paper is tilted about the tilt axis formed by the window security thread, the moiré image "<<<" formed by the microlens system moves in the longitudinal direction of the security thread (so-called orthoparallactic movement effect). The partial, non opaque, optically variable overpainting 71 is in the form of a diagonal grid. Unlike in the 3 shown, the line width of the grid lines can also be chosen wider and z. B. have the same line width of the pixel "<" of the first motif. Although the reticulation of the net retracts the visual perceptibility of the first motif formed by the windowed security thread, the exposed microoptical elements of the microlens thread are still susceptible to contamination. The pollution is caused by the glittering, optically variable overcoating 71 but effectively veiled.

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

• EP 0330733 A1 [0003, 0031]
• EP 0064067 A1 [0003, 0031]
• EP 0238043 A2 [0004, 0031]
• DE 3609090 A1 [0004, 0031]
• WO 2006/087138 A1 [0005, 0005]
• DE 102005028162 A1 [0005]
• WO 2011/066991 A2 [0006]
• DE 102009035361 A1 [0006, 0031]
• EP 0256170 B2 [0007]
• EP 1391318 B1 [0026]
• WO 2008/000755 A1 [0027]
• WO 2004/097112 A1 [0032]
• WO 00/00697 [0035]
• EP 0815321 B1 [0035]
• EP 1338430 A1 [0035]
• EP 1595029 B1 [0036]

Claims (13)

Security paper for the production of value documents, such as banknotes, passports, identity documents or the like, having a flat substrate, which is provided on at least one surface with at least one counterfeit protection means, wherein the anti-counterfeiting means is based on a carrier film with opposing first and second main surfaces and the observer at least partially perceptible, the substrate opposite the first main surface of the carrier film has an optically variable security feature that forms a perceptible in reflected light first motif, and the anti-counterfeiting means and a partial surface of the substrate surrounding the anti-counterfeiting means are provided with a partial, non-opaque, optically variable overlay of spaced, printed structural elements forming a second motif perceptible in incident light. The security paper according to claim 1, wherein the optically variable security feature of the counterfeiting assurance means is based on microimage elements, in particular microlens systems or microvoided mirror arrays, for enlarged imaging of microstructures and the partial non-opaque, optically variable overpainting has a color-shift effect. Security paper according to claim 1 or 2, wherein the partial, non-opaque, optically variable overcoating is based on effect pigments which are selected in particular from pearlescent pigments or pigments prepared on the basis of liquid-crystalline polymers. A security paper according to any one of claims 1 to 3, wherein the spaced printed structural features of the partial, non-opaque, optically variable overcoat have a percent area coverage of at most 70%, preferably at most 50%. A security paper as claimed in any one of claims 1 to 4, wherein the spaced printed structural features of the partial, non-opaque, optically variable overcoating form a dot screen, line screen or a grid of picture objects or alphanumeric characters. A security paper according to any one of claims 1 to 5, wherein the first motif formed by the optically variable security feature of the counterfeit security means comprises identical, repeating first picture elements and the second motif formed by the partial, non-opaque, optically variable overpainting comprises identical, repeating second picture elements having spaced, printed structural elements. The security paper of claim 6, wherein the shape of the first picture elements matches the shape of the second picture elements. Security paper according to one of claims 1 to 7, wherein the counterfeit security device as a security strip, patch, or security thread, in particular as a window security thread, is present. Security paper according to one of claims 1 to 8, wherein the substrate is provided at least on its outside of the partial, non-opaque, optically variable overcoating surface with a soil-repellent paint. The security paper of claim 9, wherein the soil-repellent varnish (a) is based on a physically drying, water-based dispersion varnish which cures by removal of the dispersant, or (b) is based on a UV-crosslinking varnish. A security paper according to claim 10, wherein the soil-repellent varnish is based on a physically drying, water-based dispersion varnish which cures by removal of the dispersing agent and is an aqueous dispersion of a polyacrylic resin or a polyurethane resin. Security paper according to one of claims 1 to 11, wherein the substrate is printed with characters or patterns, and the optionally present dirt-repellent paint is applied to the printed substrate and / or the optionally present dirt-repellent paint is printed. A value document, such as a banknote, a passport, an identity document or the like, wherein the value document has a security paper according to one of claims 1 to 12.

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