WO2012052108A2

WO2012052108A2 - Storable substrate and security element for producing documents of value, document of value and method for producing same

Info

Publication number: WO2012052108A2
Application number: PCT/EP2011/004827
Authority: WO
Inventors: Patrick Renner; Winfried HOFFMÜLLER
Original assignee: Giesecke & Devrient Gmbh
Priority date: 2010-09-29
Filing date: 2011-09-27
Publication date: 2012-04-26
Also published as: DE102010046839A1; ES2550773T3; WO2012052108A3; EP2621734A2; EP2621734B1

Abstract

The invention relates to a storable substrate (1) for producing documents of value, said substrate comprising an ink-receiving layer (5) which is crosslinkable subsequently by exposure to high-energy radiation. The invention further relates to a method for producing a document of value, said method comprising the following steps: providing a substrate (1) which comprises an ink-receiving layer (5); applying a printing ink curable by high-energy radiation to the ink-receiving layer (5); and subjecting the substrate (1) to high-energy radiation, to cure the printing ink. The method may preferably involve an ink-receiving layer which is crosslinkable subsequently by exposure to high-energy radiation.

Description

SUBSTRATE SUITABLE FOR STORAGE AND

SECURITY ELEMENT FOR THE MANUFACTURE OF VALUE DOCUMENTS, VALUE DOCUMENT AND METHOD FOR

PRODUCTION HEREVON

The invention relates to a substrate suitable for storage for the production of value documents, a security element suitable for storage for the production of value documents, a value document and method for the production thereof.

Value documents within the meaning of the present invention are, for example, banknotes, stocks, bonds, certificates, vouchers, checks, lottery tickets, high-quality admission tickets, passports, identity cards, credit cards and other flat valuables. Such flat valuables can be, for example, packaging for optionally high-quality products. For the purposes of the present invention, the term value document also encompasses all precursors of finished value documents which, for example, are not yet fit for circulation, such as, among others, security paper, film or film composites. Such a value document can also only be part of a valuable item.

For reasons of design or security reasons, such value documents are provided with security elements which, by virtue of their presence or their design, permit an examination of the authenticity of the value documents and at the same time serve as protection against unauthorized reproduction. A security element in the sense of the present invention can For example, a window or see-through window, which is formed for example by a transparent film, a security thread to be a typographically generated feature such as a micro-print, a film strip, a patch or a label. A security element, in particular a security element in the form of a security thread or a film strip, can be designed as an optically variable security element, wherein in the context of the present invention an optically variable security element is understood to be an optical element whose visual impression produced by a viewer depends on the viewing direction that is to say the perspective of the viewer on the optical element and possibly also of the direction of incidence of an illumination light beam. Examples of such optically variable security elements are diffraction structures that produce a viewing angle-dependent visual impression, in particular by reconstructing optically perceivable patterns, such as emboss or volume holograms and other kinegrams, such as achromatic matte structures. Another example of such optically variable elements are optical elements that exhibit a so-called color shift effect, such as single- or multi-layer thin-film interference layers or liquid crystal layers, which can be present as a continuous layer or in pigment form (so-called effect pigments such as iriodines). Further examples are lens or micromirror structures within an optically variable security element. Such optical elements have in common that they are usually based on a polymer layer, for example a plastic film, or at least comprise a polymer layer as a cover or protective layer. For the purposes of the present invention, such elements are generally referred to as security elements. In the specific case that the optical element is constructed on the basis of a plastic film, the element may be referred to as an optical film element. To increase the security against counterfeiting, that is to make it difficult to imitate, to check the authenticity or as an additional design element, it is desirable to overprint such security elements or value documents that comprise such security elements with a further imprint in addition to an optionally already applied imprint , However, the ink acceptance when overprinting such security elements is usually unsatisfactory. It is therefore known to provide ink acceptance layers on such security elements. The ink-receiving layers used for such security elements are often opaque due to excessive layer thicknesses and as a result of fillers, or have at least an undesirable clouding effect. This adversely affects the visual perceptibility or machine detectability of the security element. For example, a good undisturbed view through a window is then no longer possible. If the security element is an optically variable element, its optically variable effect can be impaired or completely prevented. On the other hand, one measure would be to provide the ink receiving layer with a reduced layer thickness or with such a filler content, so that the opacity and / or the clouding effect of the ink-accepting layer is reduced so as to ensure improved perceptibility of a security element. However, this has the disadvantage that thereby deteriorates the adhesion and drying of the ink of the applied additional imprint. If the requirement for a good ink acceptance, a more or less pronounced turbidity above the security element must be accepted. On the other hand, if there is a requirement, for example, to produce a clear inspection window, then one is satisfactory ink acceptance of the printing ink of the further imprint on the window so far not possible.

The object of the present invention is therefore to provide a substrate for the production of documents of value, which allows a good ink acceptance, adhesion and drying of a printing ink to be applied another imprint, without causing a matting or opacification of a security element located below the imprint. It is a further object of the invention to provide a value document with such a security element as well as methods for producing the value document. Another object is to provide a security element for the production of documents of value, which allows a color receiving layer with good ink acceptance, adhesion and drying of an ink of an applied further imprint.

This object is achieved by the substrate, the value document, the security element and by the methods for producing a value document according to the independent claims. The dependent claims relate to preferred Ausgestalrungen and developments of the invention.

A first aspect of the invention relates to a method for producing a value document comprising the steps:

(a) providing a substrate comprising a paint receiving layer;

(b) applying a high energy radiation curable ink to the ink receiving layer; and

(c) subjecting the substrate to high energy radiation so that the ink is cured. The substrate provided in step (a) preferably comprises a security element which is arranged in or on the substrate such that a first surface of the security element forms a common surface with a first surface of the substrate, and the ink acceptance layer over the entire surface, or at least Partial surface above the first surface of the security element or at least part of the surface above the first surface of the substrate is arranged.

The prior art paint-receiving layers heretofore used in value document substrates have been formulated to be as absorbent as possible in terms of their chemical composition in order to avoid the so-called setting of e.g. in oils and non-reactive components contained in offset and steel engraving inks. This drying step is indispensable for the further processing of the printed value documents. The absorbency of the ink-accepting layer is also advantageous for the physical drying of water-based or organic solvent-based gravure, flexographic or screen printing inks. In the ink receiving layers hitherto used in value document substrates, due to the necessary degree of filling with absorbent fillers, a strong opacity or at least a clear clouding inevitably resulted. In addition, a layer thickness of the ink-accepting layer of at least 4 μηι inevitably resulted for a sufficiently high pumping speed.

Unlike the prior art, high energy curable inks are used to make a value document according to the present invention. By "high-energy radiation" is meant here UV radiation or electron radiation. Printing inks, which are curable by high-energy radiation, generally have a high energy content Solid fraction and are based for example on unsaturated acrylates or on epoxides. Compared to conventional printing inks for offset, steel engraving, gravure, flexo or screen printing, the use of high-energy-curable printing inks results in new demands on the ink-accepting layer. The dissolution or absorption of the reactive constituents contained in the ink in the ink-accepting layer should be avoided here in order not to worsen the subsequent curing of the ink by the action of radiation and the adhesion of the ink to the substrate. A high pumping speed for the ink receiving layer is therefore unnecessary. The layer thickness of the ink receiving layer can be reduced in this way, for example, to a value within a range of 0.5 to 2 μπι. The provision of transparent ink receiving layers for security features in documents of value, such as, for example, window threads, transparent window and perforated areas or security strips to be printed, is easily possible by means of the method for producing a value document according to the first aspect of the present invention and has a positive effect on Production costs and further processing. A second aspect of the invention relates to a substrate particularly adapted for the method of manufacturing a value document according to the first aspect. The substrate according to the second aspect of the invention is a substrate suitable for storage for the production of value documents, which comprises a post-crosslinkable by the action of high-energy radiation ink-receiving layer.

The substrate preferably comprises a security element arranged in or on the substrate such that a first surface of the security element is in common with a first surface of the substrate Surface forms, wherein the post-crosslinkable by the action of high-energy radiation ink receiving layer over the entire surface or at least partially above the common surface or at least partially above the first surface of the security element or at least partially arranged above the first surface of the substrate.

The high-energy-postcrosslinkable ink-accepting layer provided to the substrate according to the second aspect of the invention is preferably a radical-curing ink-receiving layer. The high-energy-postcrosslinkable ink-accepting layer is more preferably a radical-curing ink-accepting layer obtainable by physically drying a dispersion based on unsaturated urethane acrylates. By the term "physical drying" is meant the evaporation of water or organic solvent.The physical drying results in a dry, non-sticky, ink-receptive layer which can be post-crosslinked by the action of high-energy radiation, such as UV radiation or electron beams Such a physically dried, high-energy-postcrosslinkable ink receiving layer substrate is suitable for storage and may be supplied to the customer who wishes to print the substrate to produce a value document with, among others, high energy curable inks.

A third aspect of the invention relates to a value document obtainable by:

(a) providing a substrate comprising a post-crosslinkable dye receiving layer by the action of high energy radiation; (b) applying a high-energy radiation-curable ink to the post-crosslinkable by the action of high-energy radiation ink receiving layer; and

(c) subjecting the substrate to high energy radiation so that the ink is cured and the ink receiving layer is postcrosslinked at the same time.

The substrate provided in step (a) preferably comprises a security element arranged in or on the substrate in such a way that a first surface of the security element forms a common surface with a first surface of the substrate, and the full surface area of the post-crosslinkable ink-accepting layer due to the action of high-energy radiation above the common surface or at least partially over the first surface of the security element or at least partially over the first surface of the substrate is arranged.

The printing of a substrate provided with a dye-receiving layer which can be postcrosslinked by the action of high-energy radiation with an ink curable by the action of high-energy radiation and the application of high-energy radiation to the printed substrate leads to a hardening of the printing ink and at the same time to post-crosslinking of the ink-accepting layer. It has been found that the co-curing of the ink and the ink receiving layer after printing synergistically results in extremely good adhesion at the interface between the ink accepting layer and the ink applied above the ink receiving layer (in the description below Liability is also referred to as "interlayer adhesion.") Good interlayer adhesion is believed to be due to crosslinking, eg, covalent chemical bonds, between the Ink and the ink receiving layer in the common curing or post-crosslinking of the ink and the ink receiving layer back. In this way, an extremely good ink adhesion can be achieved, in particular with value documents based on plastics, for example plastic banknotes, which results in an increase in the circulation time and a significant improvement in the security against counterfeiting.

A fourth aspect of the invention relates to a security element suitable for storage for the production of value documents, comprising at least one ink receiving layer capable of being postcrosslinked by the action of high-energy radiation, which is arranged over part of the surface or over its entire area above a first surface of the security element.

A fifth aspect of the invention relates to a method of manufacturing a value document, comprising

(a) providing a value-document substrate and a security element suitable for storage according to the fourth aspect of the invention, wherein the security element optionally has a security-element carrier applied above the ink-accepting layer;

(b) adhering the security element to the valuable-document substrate by means of an adhesive layer so that the valuable-document substrate is adhered to the opposite side of the security element from the ink-accepting layer and the optional security-element carrier so as to provide a substrate-security-element structure and, optionally, peeling off the security element support from the substrate security element structure, the ink acceptance layer serving as a release layer;

(c) applying a high energy radiation curable ink to the ink receiving layer; and (d) subjecting the substrate-security element assembly to high-energy radiation so that the ink is cured and the ink-accepting layer is simultaneously postcrosslinked. The invention will be described below with reference to preferred embodiments.

Printing inks which can be cured by high-energy radiation (for example UV radiation or electron beams) are known from the prior art (see, for example, Helmut Kipphan, "Handbuch der Printmedien", Springer-Verlag, 2000, page 140; DE 4222 576 AI).

In the manufacturing method according to the first aspect of the invention, the substrate may preferably be provided with a security element, e.g. is designed as a window, security thread, film strip, optically variable security element, printing technology generated feature or as a patch or label.

The security element may be arranged in or on the substrate such that a first surface of the security element forms a common surface with a first surface of the substrate. The ink receiving layer can be arranged over the entire surface above the common surface. A full-surface arrangement of the ink-accepting layer is advantageous, for example, when the entire surface of a valuable-document substrate is to be provided with a printing ink curable by high-energy radiation. Alternatively, the ink-accepting layer may be arranged at least partially over the first surface of the security element or at least partially over the first surface of the substrate. With the wording "at least part of the area above the first surface of the security element or substrate "is meant that either the entire first surface of the security element or substrate or only a part of the first surface of the security element or substrate is provided with the ink-accepting layer.

The ink accepting layer disposed above a first surface of the security element and / or above a first surface of the substrate may be e.g. be applied directly to a film or polymer or plastic layer of the security element or directly to the substrate. Alternatively, the ink accepting layer may be separated from the security element and / or substrate by one or more further, preferably transparent layers (such as a plastic film).

The ink-receiving layer used in the present invention is suitable for the ink acceptance of high-energy-curable printing inks. For this purpose, the ink receiving layer preferably has no or only a small proportion of filler of less than 5 wt .-%. When printing a security element with a further imprint, the ink receiving layer advantageously forms the uppermost layer and thus ensures the ink acceptance, the adhesion and the drying of the printing ink of the further imprint. The additional imprint can be applied by means of an offset method, a gravure printing method or another suitable printing method. This can be a background pressure.

The inventive use of curable by high-energy radiation inks allows the reduction of the thickness of the ink receiving layer and thus an undisturbed perception of a security element underneath. In particular, there is no Impairment due to matting or clouding. If the security element is a simple window or see-through window formed, for example, on the basis of a transparent film, the use of the thin ink-receiving layer in conjunction with radiation-cured printing inks further enables a clear view through the window. If the security element consists of an optically variable security element, then the thin ink accepting layer in combination with radiation-cured printing inks allows a perception of an unimpaired optically variable effect. The layer thickness of the ink-accepting layer is preferably 0.5 to 5 μιτι, with a layer thickness of 1 to 2 μπι is particularly preferred.

According to a first preferred embodiment, the ink accepting layer usable for the manufacturing method according to the first aspect of the invention is a paint accepting layer which is postcrosslinkable after being applied to the substrate or security element and after being physically dried by the action of high energy radiation. Such ink acceptor layers are based in particular on physically drying dispersions of saturated, unreactive acrylates. Hereinafter, a formulation example of a paint receiving layer which is not postcrosslinked by the action of high energy radiation is mentioned (in% by weight):

Formulation V.

60% ADCOTE® 102A-81R (ROHM &HAAS);

17% ethyl acetate;

19% HOT ADHESIVE BAG 751/24 L50 (company ROHM & HAAS)

4% CATALYST F (company ROHM & HAAS) According to a second preferred embodiment, the ink-receiving layer usable for the manufacturing method according to the first aspect of the invention is a paint-receiving layer which is post-crosslinkable after being applied to the substrate or security element by the action of energy radiation. Such a postcrosslinkable ink receiving layer may be a radical curing ink receiving layer or a cationic curing ink receiving layer.

Cationic curing ink-receiving layers are generally not physically drying. When using cationically curing ink-accepting layers, the subsequent application of the energy-ray curable printing ink is therefore preferably "in-line", ie in one working step After the security element or the substrate has been provided with a postcrosslinkable, cationically curing ink-accepting layer in a printing unit The postcrosslinkable, cationically curable ink-accepting layer and the ink curable by high-energy radiation are combined together by high-energy radiation, eg UV, after the end of the printing process Radiation or electron beam, cured.Co-curing leads to a particularly good interlayer adhesion.

Suitable cationic curing ink-receiving layers may be based on, for example, epoxide systems or polyol systems. In the following, formulation examples for cationically curing, color-accepting layers which are post-crosslinkable by the action of high-energy radiation are stated (in% by weight): Formulation 2:

81% cycloaliphatic epoxide, e.g. CYRACURE UVR-6110 or UVR 6107 (DOW);

10% divinyl ether, e.g. RAPICURE DVE-3;

9% initiator sulfonium ion, e.g. UVI-6991 (DOW).

Formulation 3:

81% cycloaliphatic epoxide, e.g. CYRACURE UVR-6110 (DOW); 10% propylene carbonate;

9% initiator sulfonium ion, e.g. UVI-6991 (DOW).

Formulation 4:

69% cycloaliphatic epoxide, e.g. CYRACURE UVR-6128 (DOW); 27% polyol TONE 0305 (DOW);

4% initiator sulfonium ion, e.g. UVI-6991 (DOW).

Formulation 5:

50% EBECRYL 8402 (CYTEC company);

8% 2-hydroxy-2-methyl-1-phenyl-propane-1-one, e.g. DAROCUR 1173 (CIBA);

42% GENOMER 1122 (company RAHN).

Radically curing ink-receiving layers are particularly preferred for use as the high-energy-postcrosslinkable ink-accepting layer. Radically curing ink-receiving layers are based on dispersions which physically dry after being applied to the security element or substrate, more specifically, are predried by evaporation of the solvent and subsequently postcrosslinked by the action of high-energy radiation. The on this Obtained substrates according to the second aspect of the invention are suitable for storage and can be stacked without mutual bonding. In addition, mutual bonding can be improved by introducing so-called spacers into the ink-receiving layer. As a spacer against sticking, for example, silica gels, waxes or polyolefin waxes such as polypropylene, PTFE and products with the trade names SYLOID 244, SYLOID W300, AEROSIL R 8200 GRACE or DEGUSSA can be used. The subsequent application of the energy-curable ink, eg in the form of characters or patterns, preferably takes place at the customer's site.The post-crosslinkable, free-radically curing ink-accepting layer and the high-energy-curable ink are then jointly replaced by high-energy radiation, eg UV Radiation or electron beams, hardened.The joint curing leads to a particularly good interlayer adhesion.

In particular, free radical curable ink receiving layers obtainable by physically drying a dispersion based on unsaturated urethane acrylates (e.g., aromatic urethane acrylates) are preferred. In the following, formulation examples for radically curing dye-receiving layers post-crosslinkable by the action of high-energy radiation are indicated (in% by weight):

Formulation 6:

96% L AROMER LR 9005 (BASF);

4% IRG ACURE 819 DW (CIBA company).

Formulation 7:

96% LAROMER LR 8983 (BASF); 4% IRGACURE 500 (CIBA company).

In general, the color accepting layers useful in the present invention may additionally have fillers to a limited extent as long as the absorbency of the ink accepting layer for the high energy radiation curable ink to be applied is not thereby increased too much. The filler content is preferably less than 5 wt .-%. For example, boehmite, pseudo-boehmite, zeolite, Al 2 O 3 or silica gel or a mixture of these substances can be used as the filler. With regard to the transparency of the ink receiving layer, these fillers preferably have a particle size in a range from 1 nm to 1 μm, the range from 5 nm to 200 nm being particularly preferred. The use of boehmite or pseudo-boehmite is preferred. According to "Römpp Lexikon der Chemie", 10th edition, Georg Thieme Verlag, 1996, boehmite is the rhombic crystalline metahydroxide γ-.

AIO (OH), which is obtained, for example, from crystalline Al (OH) 3 by heating for 14 days at 150 ° C in the sealed tube with dehydration. Pseudo-boehmite is an agglomerate of aluminum oxide hydroxide of the formula AI2O3 * n H2O (n = 1 to 1.5).

The adhesion of the ink-receiving layers used according to the invention to plastic layers, in particular plastic films, can additionally be improved by means of a suitable pressure pretreatment by means of corona, plasma or flame. The dye-receiving layers used according to the invention can also be used as a starting point for the development of nontransparent ink receiving layers. For this purpose, the formulation of the ink receiving layer, other additives, such as pigments, added, which produce the desired opaque property. For example, pigments such as T1O2 (eg KRONOS 2044), BaS0, Ca CO3, silicic acids, or hollow ball pigments based on polymers such as

"ROPAQUE" from Rohm & Haas or also effect pigments which produce pearlescent or metallic luster, interference pigments, liquid-crystal pigments, thermochromic or magnetic pigments, or pigments which produce phosphorescence or fluorescence or have an antistatic effect If, for example, such a color accepting layer has a high opacity due to its additives, it is advisable to implement a desired base color of the security element or of a substrate via the ink accepting layer Opacity can also be achieved by an antistatic finish, eg FT 2000 from ISHIHARA SANGYO KAISHA LTD. An antistatic finish is also possible by adding about 2% of ammonium salts (eg PN 1041 from BOSCH LABORATORIES) A preferred embodiment relates to ^" a document of value having a substrate and a feature produced as a window or window, by printing technology, Security thread, film strip, patch or label formed security feature, wherein the ink receiving layer over part of the security element or part of the surface above the substrate, preferably over the entire surface above the common surface, which is formed by a first surface of the security element with a first surface of the substrate is applied. The security element further preferably comprises a polymer layer, for example a plastic film, on which the ink-accepting layer is applied. Such a security element can be generated directly in or on a value document to be secured. Alternatively, such a security element may be a security element suitable for storage for the production of value documents according to the fourth aspect of the invention, which is prepared on an optional, separate carrier as a transfer element. Such a separate carrier preferably has one Plastic or polymer material and may for example be a film material, in particular a transfer material, or have. Plastics such as PET (polyethylene terephthalate), PBT (polybutylene terephthalate), PEN (polyethylene naphthalate), PP (polypropylene), PA (polyamide) and PE (polyethylene) are suitable for the film material. This sheet material may also be monoaxially or biaxially stretched.

The securing of the security element according to the fourth aspect of the invention on a security document to be secured is effected with the aid of an adhesive layer, a hot melt adhesive preferably being used for this purpose. After transferring the security element to a value document to be secured, the carrier material is optionally removed again so that the security element remains on the security document to be secured. The ink receiving layer serves as a release layer or release layer.

In a preferred embodiment, the security element according to the fourth aspect of the invention as. Patch or label may be formed and, for example, have a flat shape with comparable length dimensions in all directions or an elongated shape, for example in the form of a strip, as is the case with security threads or film strips, for example so-called LEAD strips. If such a security element is designed as a transfer element with an optionally transparent film as a carrier, it is also referred to as a film element, film patch or film strip.

Single or multi-layer substrates can be used as the substrate according to the invention and as the substrate provided for the production of the value document according to the invention. In the case of single-layer substrates Any type of paper or paper-like material is considered, in particular cotton vellum paper. It is also possible to use paper which contains a certain proportion x of a polymer material in the range from 0 to 100% by weight. Furthermore, a plastic layer, for example a plastic film, or a film composite can be used as the substrate. Such a film may additionally be monoaxially or biaxially stretched. Such a stretching of the film leads inter alia to obtaining polarizing properties which can be used as a security feature in the value document.

As the multilayered substrate, a multilayer composite comprising, for example, a layer of paper or a paper-like material can be used. On this layer, for example, a transparent plastic or polymer layer is laminated from both sides, whereby such a multilayer composite has an extremely high stability and durability. In this case, security papers are used with plastic or polymer coated paper layers for the production of composite film banknotes. Conversely, the multilayer composite can also have a central layer of a plastic or polymer material, which is coated on both sides with a respective layer of paper or a paper-like material. As a multilayer substrate material, a multilayer, paper-free composite material can also be used.

The security element, which is provided in the substrate according to the invention and in the value document according to the invention as a preferred embodiment, can be arranged on the surface of the substrate. However, it may also be arranged within the substrate and, for example, only partially contact the surface of the substrate, as is the case with security threads such as window or pendulum security threads. The safety The element can also fill a recess in the substrate, as is the case with windows, in particular through-windows. In the case of a multi-layer composite, such as a laminated film banknote, the security element can also be arranged below a transparent layer, eg a plastic film, or be embedded within the transparent layer.

The ink accepting layer may be placed directly on the common surface of the security element and the substrate. In a preferred embodiment, however, a further transparent layer, for example a plastic film, in particular a PET film or polyester film, is arranged between the common surface and the ink-accepting layer. In this case, the transparent layer forms, for example, a cover or protective layer for the security element and the substrate. The ink-receiving layer then ensures printability with the high-energy-curable ink of another print. The further transparent layer is preferably arranged directly on the common surface and / or the ink-accepting layer is deposited directly on the further transparent layer, e.g. a plastic film, arranged.

In a preferred embodiment of the value document according to the invention, in addition to the ink-accepting layer which can be post-crosslinked by the action of high-energy radiation, an opaque ink-accepting layer which is not post-crosslinkable by the action of high-energy radiation is additionally arranged above the common surface. The opaque ink accepting layer is preferably arranged outside, that is to say when the value document is viewed in incident light not above the security element. The security element is preferably completely only of the post-crosslinkable by the action of high-energy radiation ink receiving layer overdrawn. Such a configuration allows an arrangement of a printable by conventional inks opaque ink receiving layer on the document of value, without affecting the visibility of the security element, at the same time a good printability of the document of value above the security element is guaranteed by curable by high-energy radiation inks.

Further exemplary embodiments and advantages of the invention are explained below by way of example with reference to the accompanying figures. The examples represent preferred embodiments which in no way limit the invention. The figures shown are schematic representations that do not reflect the real proportions but serve to improve the clarity of the various embodiments.

In detail, the figures show:

Figure la a banknote with a security element in plan view;

Figure lb is a section through the banknote of Figure la;

FIGS. 2a and 2b

Sectional views through further embodiments.

In FIGS. 1 a and 1 b, a banknote having a substrate 1 is shown as a value document. On the substrate 1, the denomination "50" is printed. The substrate 1 of the document of value consists in the embodiment of a paper or a paper-like material and has a correspondingly high ink receptivity and good printability for an applied, not shown in Figure la, further imprint. On the substrate 1, a security element 2, in the present case, an optical film element, further arranged, which is a transfer element in the illustrated embodiment. The security element 2 comprises an adhesive layer 3, which comprises an activatable adhesive, for example a hot melt adhesive. With the aid of the adhesive layer 3, the central film constituent 4 of the optical film element 2 is fixed on the surface of the substrate 1. In order to ensure a good printability of the optical film element 2 and in particular of the central film component 4, the optical film element 2 further comprises a post-crosslinkable by the action of high-energy radiation ink receiving layer 5. The ink receiving layer 5 is in the present case, a radically curing ink receiving layer by physical drying of a on unsaturated urethane acrylates based dispersion is available (eg based on the above formulation 6 or Formulation 7). The dye-receiving layer 5 is suitable for the ink acceptance of high-energy-curable printing inks. Accordingly, the resulting surface of the banknote in the region of the optical film element 2 consists of the ink accepting layer 5 and the remainder of the surface of the substrate 1. Accordingly, good printability is created over the entire surface of the entire document of value, ie the ink receptivity of the substrate is achieved by applying of the described, designed as a transfer element optical film element is not affected.

FIG. 2 a shows a second exemplary embodiment of a value document in the form of a banknote. The value document in turn comprises a substrate 1, which may consist of paper or a paper-like material or else of plastic or a film. The substrate is typically (but not necessarily) opaque. In the substrate 1 is a first optical film element in the form of a window 6 (passage window) and a second optical film element arranged in the form of a security thread 7. Both window 6 and security thread 7 occur in the substrate 1 to the surface, whereby the common surface of substrate 1, window 6 and security thread 7 is generally made of different materials. In order to ensure uniform ink acceptability for the further printing to be applied, a color accepting layer 5 suitable for the ink acceptance of printing inks which are curable by high-energy radiation can be arranged directly on this common surface. The ink receiving layer 5 can be obtained, for example, starting from the above-mentioned formulations 1 to 7. The exemplary embodiment illustrated in FIG. 2a, however, is a composite film banknote in which substrate 1, as well as window 6 and security thread 7, are coated by a plastic layer 8, for example a PET film. In this case, the ink-accepting layer 5 is arranged directly on the plastic layer 8. Furthermore, the banknote shown in FIG. 2a can have further layers (not shown), such as adhesive or primer layers, which ensure, for example, sufficient adhesion of the various layers to one another. The ink-accepting layer 5 thus forms a uniform surface of the document of value and thus provides a uniform ink receptivity for high-energy radiation-curable printing inks on the entire document of value.

The further embodiment shown in section in Figure 2b differs from the embodiment shown in Figure 2a by an additional opaque ink receiving layer 9, which is suitable for the color image of conventional, non-radiation-curing inks. The ink accepting layer 5, which is suitable for color pickup of high-energy-curable printing inks, is disposed above the opaque ink-receiving layer 9, that is, the ink-receiving layer 5 is coated in a later step than the opaque ink receiving layer 9 applied.

In the exemplary embodiment shown in FIG. 2b, the ink-acceptance layer 5 has the same layer thickness as the opaque ink-accepting layer 9. In fact, the layer thickness of the suitable for the ink acceptance of radiation-curing inks ink receiving layer 5 preferably has a value within a range of 0.5 to 5 μιη, more preferably 1 to 2 μπι. The layer thickness of the ink-accepting layer 5 is less than the layer thickness of the opaque ink-accepting layer 9, which is suitable for the ink acceptance of conventional printing inks and typically has a value of at least 4 μm.

In the exemplary embodiments shown in FIGS. 1a to 2b, the invention has been described with reference to security elements formed as optical film elements, which are formed on the basis of a film. However, the present invention is not limited to optical film elements. It could just as security elements are used, which have a polymer film instead of a plastic film. Likewise, the security element may be e.g. around a typographically generated feature, e.g. a micro-pressure, act.

Claims

Patent claims

1. suitable for storage substrate (1) for the production of value documents, comprising a post-crosslinkable by the action of high-energy radiation ink receiving layer (5).

2. Substrate according to claim 1, characterized in that the substrate comprises a security element (6, 7) which is arranged in or on the substrate (1) such that a first surface of the security element (6, 7) having a first surface of the substrate (1) forms a common surface, wherein the post-crosslinkable by the action of high-energy radiation ink receiving layer (5) over the entire surface above the common surface or at least partially above the first surface of the security element (6, 7) or at least part of the surface above the first surface of the substrate (1) is arranged.

3. Substrate according to claim 1 or 2, characterized in that the post-crosslinkable by the action of high-energy radiation ink receiving layer (5) is a radically curing ink-accepting layer.

4. A substrate according to claim 3, characterized in that the post-crosslinkable by the action of high-energy radiation ink receiving layer is obtained by physically drying a dispersion based on unsaturated urethane acrylates.

5. Substrate according to one of claims 2 to 4, characterized in that the security element (6, 7) as a window, security thread, foil strip, printing technology generated feature, patch or label is formed.

6. Substrate according to one of claims 1 to 5, characterized in that a transparent layer (8), preferably a plastic film, between the substrate (1) and the ink receiving layer (5) is arranged.

7. Value document, available through

(A) providing a substrate (1) comprising a post-crosslinkable by the application of high-energy radiation ink receiving layer (5);

(b) applying a high-energy-curable ink to the post-crosslinkable by the action of high-energy radiation ink receiving layer (5); and

(C) applying high-energy radiation to the substrate (1) so that the ink is cured and the ink-accepting layer (5) is simultaneously postcrosslinked.

8. A document of value according to claim 7, characterized in that the substrate (1) provided in step (a) comprises a security element (6, 7) arranged in or on the substrate (1) such that a first surface of the security element (6, 7) forms a common surface with a first surface of the substrate (1), and the ink receiving layer (5) postcrosslinkable by the action of energy-rich radiation over the entire surface or at least partially over the first surface of the security element (6, 7) or at least partially over the first surface of the substrate (1) is arranged.

9. Value document according to claim 7 or 8, characterized in that the post-crosslinkable by the action of high-energy radiation ink receiving layer (5) is a radically curing ink-receiving layer or a cationic curing ink-receiving layer.

10. document of value according to claim 9, characterized in that the post-crosslinkable by the action of high-energy radiation ink receiving layer (5) is a radically curing ink-receiving layer and is obtainable by drying a dispersion based on unsaturated urethane acrylates.

11. document of value according to one of claims 8 to 10, characterized in that the security element (6, 7) as a window, security thread, foil strip, typographically generated feature, patch or label is formed.

12. document of value according to one of claims 7 to 11, characterized in that a transparent layer (8), preferably a plastic film, between the substrate (1) and the ink receiving layer (5) is arranged.

13. For storage suitable security element for the production of documents of value, comprising at least one post-crosslinkable by the action of high-energy radiation ink receiving layer, which is arranged over part of the surface or the entire surface above a first surface of the security element.

14. A security element according to claim 13, characterized in that the post-crosslinkable by the action of high-energy radiation Farban- is a free-radically curing ink-receiving layer.

15. A security element according to claim 14, characterized in that the nachvernetzbare by the action of high-energy radiation Farban- took place by physically drying one on unsaturated

Urethanacrylaten based dispersion is available.

16. Method for producing a value document with the steps:

(a) providing a substrate (1) comprising a paint receiving layer (5);

(b) applying a high-energy-curable ink to the ink-receiving layer (5); and

(c) subjecting the substrate (1) to high energy radiation so that the ink is cured.

17. The method according to claim 16, characterized in that in step (a) provided substrate (1) comprises a security element (6, 7) which is arranged in or on the substrate (1) that a first surface of the security element (6, 7) with a first surface of the substrate (1) forms a common surface, and the ink receiving layer (5) over the entire surface above the common surface or at least partially above the first surface of the security element (6, 7) or at least part of the surface above the first Surface of the substrate (1) is arranged

18. The method according to claim 16 or 17, characterized in that the ink-accepting layer (5) in step (a) is a post-crosslinkable by the action of high-energy radiation ink receiving layer, and in step (c) the substrate is acted upon by high-energy radiation, so that the Hardened ink and the ink receiving layer is postcrosslinked simultaneously.

19. The method according to claim 18, characterized in that the nachvernetzbare by the action of high-energy radiation ink acceptance Layer (5) is a free-radically curing ink-receiving layer or a cationic-curing ink-receiving layer.

20. The method according to claim 19, characterized in that the post-crosslinkable by the action of high-energy radiation ink receiving layer (5) is a radically curing ink-receiving layer and is obtainable by physical drying of a dispersion based on unsaturated urethane acrylates.

21. The method according to any one of claims 17 to 20, characterized in that the security element (6, 7) as a window, security thread, foil strip, printing technology generated feature, patch or label is formed.

22. The method according to any one of claims 16 to 21, characterized in that a transparent layer (8), preferably a plastic film, between the substrate (1) and the ink receiving layer (5) is arranged.

23. value document obtainable by the method according to one of claims 16 to 22 .. <i. _f

24. A method of producing a value document, comprising:

(a) providing a valuable document substrate and a security element suitable for storage according to one of claims 13 to 15, wherein the security element optionally has a security element carrier applied above the ink accepting layer;

(b) adhering the security element to the value-document substrate by means of an adhesive layer so that the value-document substrate is glued to the side of the security element opposite the ink-accepting layer and the optional security-element carrier in order to be applied thereto To provide a substrate security element structure, and optionally a peel off of the security element carrier from the substrate security element structure, wherein the ink accepting layer serves as a release layer;

(c) applying a high energy radiation curable ink to the ink receiving layer; and

(d) subjecting the substrate-security element assembly to high-energy radiation so that the ink is cured and the ink-accepting layer is simultaneously postcrosslinked.