DE102018004432A1 - Value document, method for producing the same and printing device - Google Patents

Value document, method for producing the same and printing device

Info

Publication number
DE102018004432A1
DE102018004432A1 DE102018004432.8A DE102018004432A DE102018004432A1 DE 102018004432 A1 DE102018004432 A1 DE 102018004432A1 DE 102018004432 A DE102018004432 A DE 102018004432A DE 102018004432 A1 DE102018004432 A1 DE 102018004432A1
Authority
DE
Germany
Prior art keywords
security element
medium
pigments
matrix
μm
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
DE102018004432.8A
Other languages
German (de)
Inventor
Raphael Dehmel
Maik Rudolf Johann Scherer
Kai Herrmann Scherer
Tobias Sattler
Michael Rahm
Harald Lesch
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Giesecke and Devrient Currency Technology GmbH
Original Assignee
Giesecke and Devrient Currency Technology GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Giesecke and Devrient Currency Technology GmbH filed Critical Giesecke and Devrient Currency Technology GmbH
Priority to DE102018004432.8A priority Critical patent/DE102018004432A1/en
Publication of DE102018004432A1 publication Critical patent/DE102018004432A1/en
Application status is Pending legal-status Critical

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B42BOOKBINDING; ALBUMS; FILES; SPECIAL PRINTED MATTER
    • B42DBOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS
    • B42D25/00Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof
    • B42D25/30Identification or security features, e.g. for preventing forgery
    • B42D25/36Identification or security features, e.g. for preventing forgery comprising special materials
    • B42D25/369Magnetised or magnetisable materials
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B42BOOKBINDING; ALBUMS; FILES; SPECIAL PRINTED MATTER
    • B42DBOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS
    • B42D25/00Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof
    • B42D25/30Identification or security features, e.g. for preventing forgery
    • B42D25/36Identification or security features, e.g. for preventing forgery comprising special materials
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B42BOOKBINDING; ALBUMS; FILES; SPECIAL PRINTED MATTER
    • B42DBOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS
    • B42D25/00Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof
    • B42D25/30Identification or security features, e.g. for preventing forgery
    • B42D25/36Identification or security features, e.g. for preventing forgery comprising special materials
    • B42D25/378Special inks

Abstract

The invention relates to a security element with an external magnetic field changeable optical appearance, wherein the security element has a solid matrix and a solid matrix enclosed plurality of microscopic chambers and filled the microscopic chambers with a liquid medium and magnetic, alignable by an external magnetic field pigments are.

Description

  • The invention relates to a method for producing a value document, in particular a banknote, and a document of value obtainable by the method. The invention further relates to a printing device suitable for carrying out the method.
  • Data carriers, such as valuables or identity documents, or other valuables, such as branded articles, are often provided with security elements for the purpose of security, which permit verification of the authenticity of the data carriers and at the same time serve as protection against unauthorized reproduction. Security elements with viewing-angle-dependent effects play a special role in the authentication of authenticity since they can not be reproduced even with the most modern copiers. The security elements are thereby equipped with optically variable elements that give the viewer a different image impression under different viewing angles and, for example, show a different color or brightness impression and / or another graphic motif depending on the viewing angle.
  • Security features for securing value documents, in particular banknotes, which contain magnetically orientable effect pigments are known in the prior art. Magnetically orientable effect pigments are e.g. commercially available under the trade name OVMI® from SICPA (the abbreviation OVMI stands for the term "optically variable magnetic ink"). The pigments typically have a platelet-like structure and are in the form of a layer composite which often includes two layers of optical effect layers and a magnetic layer embedded therebetween. With respect to the optical effect layers, metallic reflecting layers as well as color shifting layer systems, e.g. with an absorber / dielectric / reflector structure, in question. The embedded magnetic layer is usually invisible, but is required to align the pigments.
  • The pigments dissolved or dispersed in a printing ink are printed on a carrier substrate, for example banknote paper or a polymeric banknote substrate. Immediately after printing, the ink is still liquid, so that the platelet-shaped pigments within the color matrix surrounding the pigments are still freely movable. Subsequently, an external magnetic field is applied in which the pigments align themselves, the pigments typically being arranged parallel to the field lines due to the shape anisotropy. In this state, the color matrix surrounding the effect pigments is cured either by UV radiation or by the application of heat, so that the effect pigments are immobilized in the aligned state. For an observer arises in this way an optically variable effect, such as a light reflection that runs along the tilting direction when tilting the printing technology security element obtained. Depending on the applied magnetic field, various optically variable effects can be realized.
  • Furthermore, manufacturing processes are known from the prior art, which ensure the permanent inclusion of particles or pigments within liquid media by means of a fixed enclosure, so that the particles or pigments remain freely movable and, for example rotatable about several axes (see, eg WO 2009/074284 A2 ). In this way, encapsulated, optically variable, magnetic pigments can be realized, which can be applied by printing to a printing substrate. By means of such encapsulated pigments can be produced by printing technology security elements whose optical effect can be influenced to a large extent by an applied magnetic field. The font WO 2010/142391 A1 For example, describes a security element with a changeable by an external magnetic field visual appearance. The security element has a plurality of microcapsules containing a suspension of a carrier liquid and magnetic nanoparticles. The nanoparticles reversibly form a photonic crystal in an external magnetic field of a magnet.
  • The encapsulation processes known from the prior art are associated with the disadvantage that e.g. The size of the individual capsules and the number of particles per capsule are controllable only to a limited extent and vary widely. In addition, many expensive process steps are usually required, e.g. dispersing the particles in oil, dispersing the thus-obtained oil in water, carrying out encapsulation, washing and sorting the capsules, preparing a curable ink from the capsules, and printing the obtained ink onto a substrate, followed by curing the applied printing ink.
  • It is an object of the present invention to provide a manufacturing method associated with simplified manufacture or processing, in particular allowing improved control over the capsule size or capsule size population.
  • This object is achieved on the basis of the feature combination defined in the independent claim.
  • Further developments of the invention are the subject of the dependent claims.
  • Summary of the invention
  • 1. (First aspect of the invention) A security element having an external magnetic field variable optical appearance, the security element comprising a solid matrix and a solid matrix enclosed plurality of microscopic chambers and the microscopic chambers with a liquid medium and magnetic, by an external Magnetic field alignable pigments are filled.
  • 2. (Preferred Embodiment) A security element according to clause 1, wherein the magnetic pigments are magnetic effect pigments or magnetic nanoparticles or magnetic liquid crystals.
  • 3. (Preferred Embodiment) A security element according to clause 1 or 2, wherein magnetic pigments are present exclusively within the microscopic chambers and not within the solid matrix, or magnetic pigments are substantially absent almost exclusively within the microscopic chambers and within the solid matrix.
  • 4. (Preferred Embodiment) A security element according to clause 1 or 2, wherein magnetic pigments are present both within the microscopic chambers and within the solid matrix and the magnetic pigments present within the solid matrix are not alignable by an external magnetic field, i. are immobile, preferably wherein the present within the microscopic chambers magnetic pigments on the one hand and present within the solid matrix magnetic pigments on the other hand, in each case pigments according to a first type or pigments according to a second kind, i. have a visually distinguishable visual effect for the viewer.
  • 5. (Preferred Embodiment) A security element according to any one of clauses 1 to 4, wherein the security element is flat and preferably has a thickness in a range of 2 μm to 200 μm, particularly preferably a thickness in a range of 10 μm to 60 μm.
  • 6. (Preferred embodiment) A security element according to any one of clauses 1 to 5, wherein the microscopic chambers are substantially spherical and preferably have a diameter in the range of 1 micron to 100 microns, more preferably a diameter in the range of 5 microns to 40 microns ,
  • 7. (Preferred embodiment) Security element according to clause 3 or according to one of the clauses referenced clause 3 clauses 5 or 6, wherein for the viewer when viewing the security element only a viewing angle-dependent optical effect is perceptible in a variable external magnetic field to a variable visual appearance leads.
  • 8. (Preferred embodiment) Security element according to clause 4 or according to one of the clause 4 referring back to clause 4, wherein for the viewer when viewing the security element, a superposition of two optical effects is perceptible, namely a viewing angle-dependent optical effect, in a variable external Magnetic field leads to no variable optical appearance, and a viewing angle-dependent optical effect, which leads to a variable optical appearance in a variable external magnetic field.
  • 9. (Preferred embodiment) Security element according to one of the clauses 1 to 8, wherein the microscopic chambers in the security element are present in regions in the form of patterns, characters or a coding.
  • 10. (Second aspect of the invention) A method of manufacturing the security element according to any one of clauses 1 to 9, comprising the following steps:
  1. 1) dispersing the particles in the liquid capsule medium;
  2. 2) dispersing the capsule medium obtained in step 1 in the liquid matrix medium such that the particles remain in the capsule medium and do not migrate into the matrix medium;
  3. 3) the printing technology applying the resulting mixture to a substrate;
  4. 4) the modification of the printing system applied to the substrate, so that the viscosity of the matrix medium increases sharply and the matrix medium solidifies while the capsule medium remains liquid.
  • 11. (Third aspect of the invention) A method of manufacturing the security element according to any one of clauses 1 to 9, comprising the following steps:
    1. 1) the mixing of the capsule medium and the matrix medium to give a homogeneous liquid;
    2. 2) dispersing the particles in the liquid obtained in step 1;
    3. 3) the printing technology applying the resulting mixture to a substrate;
    4. 4) the modification of the printing system applied to the substrate, so that the viscosity of the matrix medium increases sharply and the matrix medium solidifies while the capsule medium remains liquid.
  • 12. (Fourth aspect of the invention) Data carrier with a security element according to one of the clauses 1 to 9.
  • 13. (Preferred Embodiment) Data carrier according to clause 12, wherein the data carrier is a banknote or another value document, a passport, a document, payment card or an ID card.
  • Detailed Description of the Preferred Embodiments
  • In the present specification, the abbreviation OVMI® pigments is used instead of the term "magnetically orientable effect pigments".
  • According to the present invention, a security element can be provided which comprises a solid matrix and a plurality of microscopic chambers enclosed by the solid matrix, said microscopic chambers being filled with a liquid medium and particles, e.g. optically variable pigments and / or nanoparticles are filled. According to a preferred embodiment, the solid matrix may also contain particles, e.g. optically variable pigments and / or nanoparticles.
  • The security element according to the invention is essentially flat and preferably has a thickness in a range from 2 μm to 200 μm, particularly preferably a thickness in a range from 10 μm to 60 μm.
  • The microscopic chambers are substantially spherical and preferably have a diameter in the range of 1 .mu.m to 100 .mu.m, particularly preferably a diameter in the range of 5 .mu.m to 40 .mu.m. The liquid medium is in particular substantially transparent.
  • A method for producing the inventive security element according to a first preferred embodiment comprises the following steps:
    1. 1. The dispersing of the particles in the liquid capsule medium.
    2. 2. The dispersion of the capsule medium obtained in step 1 in the liquid matrix medium so that the particles remain in the capsule medium and do not pass into the matrix medium.
    3. 3. The technical printing application of the mixture obtained on a substrate.
    4. 4. Modifying the pressure applied to the substrate system so that the viscosity of the matrix medium increases sharply and the matrix medium solidifies while the capsule medium remains liquid and in the form of small droplets.
  • In order to ensure that the particles can be dispersed in step 1 and do not pass into the matrix medium in step 2, it is preferred to select or modify the particles so that a sufficiently high miscibility of the particles with the capsule medium and results in a significantly reduced miscibility of the particles with the matrix medium.
  • According to one variant, the particles are introduced only after step 2, provided that the miscibility of the particles is so selective that the particles inevitably accumulate exclusively in the capsule medium.
  • In order to ensure that the most stable possible dispersion is generated in step 2, the capsule medium and the matrix medium are such that the two media do not dissolve into one another (or form a homogeneous solution together). This can e.g. be achieved by either using insoluble materials, or the materials are modified by additives so that their solubility is sufficiently low. Also possible are methods that result in a physical barrier, such as the provision of surfactant layers.
  • The printing technology application of the mixture in step 3 can be done for example by gravure, flexographic, screen or inkjet.
  • In order for the matrix medium to be selectively cured in step 4, it should preferably be chosen so that a polymerization reaction or crosslinking reaction can be started in a controlled manner. Possibilities for this are e.g. the activation of a photoinitiator contained in the medium by UV radiation, or the thermal activation of the reaction, e.g. by IR radiation, or the chemical activation of the reaction by addition of a suitable additive.
  • A method for producing the inventive security element according to a second preferred embodiment comprises the following steps:
    1. 1. Mix the capsule medium and the matrix medium to give a homogeneous liquid.
    2. 2. The dispersion of the particles in the liquid obtained in step 1.
    3. 3. The technical printing application of the mixture obtained on a substrate.
    4. 4. The modification of the printing system applied to the substrate, so that the viscosity of the matrix medium increases sharply and the matrix medium solidifies while the capsule medium remains liquid. During this process, a phase separation takes place in which the two media segregate locally so that the capsule medium forms substantially spherical inclusions in the matrix medium, the particles being present exclusively in the capsule medium.
  • To carry out steps 1 and 2, it is advantageous that the miscibility of the three materials is sufficiently high. Step 3 is analogous to step 3 of the method of manufacturing according to the first preferred embodiment. With reference to step 4, miscibility in the course of curing is required to greatly change. This is e.g. in the case of selective polymerizations, during the polymerization the viscosity of the material increases, at the same time the solubility in other media decreases. The system and the curing process are chosen so that the segregation is complete before the viscosity becomes too high, local reorganizations occur and the material solidifies.
  • A preferred way of accelerating demixing is to put the particles into vibratory motion. This can be achieved, for example, in the case of magnetic particles by the use of a temporally variable, external magnetic field.
  • Furthermore, the miscibilities can be drastically and selectively changed by the surface of the particles is modified by so-called self-assembled monolayers (or "self-assembled monolayers" or SAMs). Self-assembled monolayers may be formed from molecules having two distinct ends: one end serving to adhere to the surface to be coated, the other serving to modify miscibility. With regard to surface adhesion, e.g. Silane groups, phosphate groups or phosphoric acids are used. With regard to miscibility modification, hydrocarbon chains are preferably used. In order to impart hydrophobicity to the hydrocarbon chains, the hydrocarbon chains can be fluorinated in particular. In order to impart hydrophilicity to the hydrocarbon chains, e.g. Used O-H groups.
  • The invention will be explained in more detail with reference to embodiments.
  • Embodiment 1
  • A security element according to the invention is produced on the basis of the above-described manufacturing method according to the first or the second preferred embodiment. Particles used are commercially available OVMI® pigments. The OVMI® pigments are contained exclusively in the liquid inclusions of the security element. The security element can be checked for authenticity by e.g. a permanent magnet is brought close to the security element and the drastic change of the visual effect is perceived by the viewer. The security element is characterized by the fact that the lines of light reflection follow the movement of the magnet without noticeable time delay.
  • Embodiment 2:
  • A security element according to the invention is produced on the basis of the above-described manufacturing method according to the first or the second preferred embodiment. Particles used are commercially available OVMI® pigments. The manufacturing process is modified so that OVMI® pigments are located both in the liquid inclusions of the security element and within the solid matrix. As the matrix hardens, a special magnetic field is applied so that both the pigments in the matrix and the pigments in the capsules align with the field lines of the magnetic field. Only the pigments in the capsules can later be influenced with magnetic fields and orient differently, the pigments in the matrix are firmly anchored and fixed with respect to the spatial orientation. A viewer thus always sees an overlay of a constantly the same optically variable effect and a variable optically variable effect. The verification of the authenticity of the security element can therefore also be done without the use of a magnet.
  • Embodiment 3
  • Embodiment 3 was carried out analogously to Embodiment 2, with the difference that two different types of OVMIO pigments are present in the security element, which are modified so that the OVMI® pigments according to grade 1 are present only in the matrix medium and the OVMI ® pigments according to the Variety 2 is only present in the capsule medium. Since the OVMI® pigments according to grade 1 and according to grade 2 have different colors, the two optical effects described in embodiment 2 can be distinguished even more clearly from one another by the viewer.
  • 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 2009/074284 A2 [0005]
    • WO 2010/142391 A1 [0005]

    Claims (13)

    1. A security element having an optical appearance variable by an external magnetic field, the security element having a solid matrix and a plurality of microscopic chambers enclosed by the solid matrix and the microscopic chambers filled with a liquid medium and magnetic pigments alignable by an external magnetic field.
    2. Security element after Claim 1 wherein the magnetic pigments are magnetic effect pigments or magnetic nanoparticles or magnetic liquid crystals.
    3. Security element after Claim 1 or 2 where magnetic pigments are present only within the microscopic chambers and not within the solid matrix, or magnetic pigments are substantially absent almost exclusively within the microscopic chambers and within the solid matrix.
    4. Security element after Claim 1 or 2 in which magnetic pigments are present both within the microscopic chambers and within the solid matrix and the magnetic pigments present within the solid matrix are not alignable, ie immobile, by an external magnetic field, preferably the magnetic pigments present within the microscopic chambers on the one hand and the On the other hand, magnetic pigments present within the solid matrix on the other hand are in each case pigments according to a first type or pigments according to a second type, ie have a visually distinguishable optical effect for the viewer.
    5. Security element according to one of Claims 1 to 4 wherein the security element is flat and preferably has a thickness in a range of 2 μm to 200 μm, particularly preferably a thickness in a range of 10 μm to 60 μm.
    6. Security element according to one of Claims 1 to 5 wherein the microscopic chambers are substantially spherical and preferably have a diameter in the range of 1 μm to 100 μm, more preferably a diameter in the range of 5 μm to 40 μm.
    7. Security element after Claim 3 or after one of the Claim 3 referred back Claims 5 or 6 In the case of the viewing of the security element, only a viewing-angle-dependent optical effect can be perceived by the observer, which leads to a variable optical appearance in a variable external magnetic field.
    8. Security element after Claim 4 or after one of the Claim 4 referred back Claims 5 or 6 in which the observer can observe a superimposition of two optical effects when viewing the security element, namely a viewing angle-dependent optical effect which does not result in a variable optical appearance in a variable external magnetic field, and a viewing angle-dependent optical effect which results in a variable external magnetic field changeable optical appearance leads.
    9. Security element according to one of Claims 1 to 8th , wherein the microscopic chambers in the security element are present in regions in the form of patterns, characters or a coding.
    10. Method for producing the security element according to one of Claims 1 to 9 comprising the following steps: 1) dispersing the particles in the liquid capsule medium; 2) dispersing the capsule medium obtained in step 1 in the liquid matrix medium such that the particles remain in the capsule medium and do not migrate into the matrix medium; 3) the printing technology applying the resulting mixture to a substrate; 4) the modification of the printing system applied to the substrate, so that the viscosity of the matrix medium increases sharply and the matrix medium solidifies while the capsule medium remains liquid.
    11. Method for producing the security element according to one of Claims 1 to 9 comprising the steps of: 1) mixing the capsule medium and the matrix medium to give a homogeneous liquid; 2) dispersing the particles in the liquid obtained in step 1; 3) the printing technology applying the resulting mixture to a substrate; 4) the modification of the printing system applied to the substrate, so that the viscosity of the matrix medium increases sharply and the matrix medium solidifies while the capsule medium remains liquid.
    12. Disk with a security element according to one of Claims 1 to 9 ,
    13. Disk after Claim 12 , wherein the data carrier is a banknote or other document of value, a passport, a document, a payment card or an identity card.
    DE102018004432.8A 2018-06-05 2018-06-05 Value document, method for producing the same and printing device Pending DE102018004432A1 (en)

    Priority Applications (1)

    Application Number Priority Date Filing Date Title
    DE102018004432.8A DE102018004432A1 (en) 2018-06-05 2018-06-05 Value document, method for producing the same and printing device

    Applications Claiming Priority (2)

    Application Number Priority Date Filing Date Title
    DE102018004432.8A DE102018004432A1 (en) 2018-06-05 2018-06-05 Value document, method for producing the same and printing device
    PCT/EP2019/000169 WO2019233622A1 (en) 2018-06-05 2019-05-28 Value document, method for manufacturing same and printing device

    Publications (1)

    Publication Number Publication Date
    DE102018004432A1 true DE102018004432A1 (en) 2019-12-05

    Family

    ID=66810747

    Family Applications (1)

    Application Number Title Priority Date Filing Date
    DE102018004432.8A Pending DE102018004432A1 (en) 2018-06-05 2018-06-05 Value document, method for producing the same and printing device

    Country Status (2)

    Country Link
    DE (1) DE102018004432A1 (en)
    WO (1) WO2019233622A1 (en)

    Citations (2)

    * Cited by examiner, † Cited by third party
    Publication number Priority date Publication date Assignee Title
    WO2009074284A2 (en) 2007-12-11 2009-06-18 Giesecke & Devrient Gmbh Optically variable security element
    WO2010142391A1 (en) 2009-06-10 2010-12-16 Giesecke & Devrient Gmbh Security element containing a magnetic fluid

    Patent Citations (2)

    * Cited by examiner, † Cited by third party
    Publication number Priority date Publication date Assignee Title
    WO2009074284A2 (en) 2007-12-11 2009-06-18 Giesecke & Devrient Gmbh Optically variable security element
    WO2010142391A1 (en) 2009-06-10 2010-12-16 Giesecke & Devrient Gmbh Security element containing a magnetic fluid

    Also Published As

    Publication number Publication date
    WO2019233622A1 (en) 2019-12-12

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