CA2677418A1 - Security and/or valuable document having a photonic crystal - Google Patents
Security and/or valuable document having a photonic crystal Download PDFInfo
- Publication number
- CA2677418A1 CA2677418A1 CA002677418A CA2677418A CA2677418A1 CA 2677418 A1 CA2677418 A1 CA 2677418A1 CA 002677418 A CA002677418 A CA 002677418A CA 2677418 A CA2677418 A CA 2677418A CA 2677418 A1 CA2677418 A1 CA 2677418A1
- Authority
- CA
- Canada
- Prior art keywords
- security
- valuable document
- cording
- photonic crystal
- luminescent
- 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.)
- Granted
Links
- 239000004038 photonic crystal Substances 0.000 title claims abstract description 67
- 239000000126 substance Substances 0.000 claims abstract description 73
- 239000000758 substrate Substances 0.000 claims abstract description 25
- 239000002245 particle Substances 0.000 claims description 54
- 239000011162 core material Substances 0.000 claims description 33
- 239000000463 material Substances 0.000 claims description 26
- 238000004020 luminiscence type Methods 0.000 claims description 25
- 230000005855 radiation Effects 0.000 claims description 19
- 238000000034 method Methods 0.000 claims description 18
- 229910052751 metal Inorganic materials 0.000 claims description 15
- 238000000576 coating method Methods 0.000 claims description 14
- 239000000203 mixture Substances 0.000 claims description 14
- 239000002184 metal Substances 0.000 claims description 13
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 claims description 12
- 102000006830 Luminescent Proteins Human genes 0.000 claims description 12
- 108010047357 Luminescent Proteins Proteins 0.000 claims description 12
- 239000011248 coating agent Substances 0.000 claims description 12
- 238000004519 manufacturing process Methods 0.000 claims description 12
- 239000000049 pigment Substances 0.000 claims description 12
- -1 Y2O2S : Eu Inorganic materials 0.000 claims description 11
- 239000011521 glass Substances 0.000 claims description 11
- 230000004224 protection Effects 0.000 claims description 9
- 125000001931 aliphatic group Chemical group 0.000 claims description 8
- 125000003118 aryl group Chemical group 0.000 claims description 8
- 239000000975 dye Substances 0.000 claims description 8
- 239000007850 fluorescent dye Substances 0.000 claims description 8
- 238000012856 packing Methods 0.000 claims description 8
- 229920005989 resin Polymers 0.000 claims description 8
- 239000011347 resin Substances 0.000 claims description 8
- NIXOWILDQLNWCW-UHFFFAOYSA-M Acrylate Chemical compound [O-]C(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-M 0.000 claims description 7
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N Phenol Chemical compound OC1=CC=CC=C1 ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 claims description 6
- 229910052771 Terbium Inorganic materials 0.000 claims description 6
- 229920001519 homopolymer Polymers 0.000 claims description 6
- 229910052748 manganese Inorganic materials 0.000 claims description 6
- 229920000647 polyepoxide Polymers 0.000 claims description 6
- 239000004202 carbamide Substances 0.000 claims description 5
- 238000009833 condensation Methods 0.000 claims description 5
- 230000005494 condensation Effects 0.000 claims description 5
- 230000009969 flowable effect Effects 0.000 claims description 5
- 239000004417 polycarbonate Substances 0.000 claims description 5
- 229920000877 Melamine resin Polymers 0.000 claims description 4
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 claims description 4
- 239000004952 Polyamide Substances 0.000 claims description 4
- 239000004793 Polystyrene Substances 0.000 claims description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 4
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 claims description 4
- 229920003180 amino resin Polymers 0.000 claims description 4
- 229910052787 antimony Inorganic materials 0.000 claims description 4
- ZYGHJZDHTFUPRJ-UHFFFAOYSA-N benzo-alpha-pyrone Natural products C1=CC=C2OC(=O)C=CC2=C1 ZYGHJZDHTFUPRJ-UHFFFAOYSA-N 0.000 claims description 4
- XJHABGPPCLHLLV-UHFFFAOYSA-N benzo[de]isoquinoline-1,3-dione Chemical class C1=CC(C(=O)NC2=O)=C3C2=CC=CC3=C1 XJHABGPPCLHLLV-UHFFFAOYSA-N 0.000 claims description 4
- 229920001577 copolymer Polymers 0.000 claims description 4
- 235000001671 coumarin Nutrition 0.000 claims description 4
- 150000004775 coumarins Chemical class 0.000 claims description 4
- JDSHMPZPIAZGSV-UHFFFAOYSA-N melamine Chemical compound NC1=NC(N)=NC(N)=N1 JDSHMPZPIAZGSV-UHFFFAOYSA-N 0.000 claims description 4
- 125000001434 methanylylidene group Chemical group [H]C#[*] 0.000 claims description 4
- 150000004893 oxazines Chemical class 0.000 claims description 4
- 229920002239 polyacrylonitrile Polymers 0.000 claims description 4
- 229920002647 polyamide Polymers 0.000 claims description 4
- 229920000728 polyester Polymers 0.000 claims description 4
- 239000004814 polyurethane Substances 0.000 claims description 4
- 229920000915 polyvinyl chloride Polymers 0.000 claims description 4
- 150000004897 thiazines Chemical class 0.000 claims description 4
- 150000005075 thioxanthenes Chemical class 0.000 claims description 4
- 150000003732 xanthenes Chemical class 0.000 claims description 4
- 229920002396 Polyurea Polymers 0.000 claims description 3
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims description 3
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 claims description 3
- 229910052681 coesite Inorganic materials 0.000 claims description 3
- 229910052802 copper Inorganic materials 0.000 claims description 3
- 229910052906 cristobalite Inorganic materials 0.000 claims description 3
- 238000003475 lamination Methods 0.000 claims description 3
- 230000000737 periodic effect Effects 0.000 claims description 3
- 229920001568 phenolic resin Polymers 0.000 claims description 3
- 229920000515 polycarbonate Polymers 0.000 claims description 3
- 229920001195 polyisoprene Polymers 0.000 claims description 3
- 229920002635 polyurethane Polymers 0.000 claims description 3
- 229910052682 stishovite Inorganic materials 0.000 claims description 3
- XOLBLPGZBRYERU-UHFFFAOYSA-N tin dioxide Chemical compound O=[Sn]=O XOLBLPGZBRYERU-UHFFFAOYSA-N 0.000 claims description 3
- 229910052905 tridymite Inorganic materials 0.000 claims description 3
- RRHGJUQNOFWUDK-UHFFFAOYSA-N Isoprene Chemical compound CC(=C)C=C RRHGJUQNOFWUDK-UHFFFAOYSA-N 0.000 claims description 2
- 229930040373 Paraformaldehyde Natural products 0.000 claims description 2
- 229920003171 Poly (ethylene oxide) Polymers 0.000 claims description 2
- 239000005062 Polybutadiene Substances 0.000 claims description 2
- 239000004698 Polyethylene Substances 0.000 claims description 2
- 239000004743 Polypropylene Substances 0.000 claims description 2
- 239000000853 adhesive Substances 0.000 claims description 2
- 230000001070 adhesive effect Effects 0.000 claims description 2
- 229910052785 arsenic Inorganic materials 0.000 claims description 2
- 229910052797 bismuth Inorganic materials 0.000 claims description 2
- 125000000484 butyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])C([H])([H])[H] 0.000 claims description 2
- 229910052793 cadmium Inorganic materials 0.000 claims description 2
- 150000004770 chalcogenides Chemical class 0.000 claims description 2
- 229910052634 enstatite Inorganic materials 0.000 claims description 2
- 229910052732 germanium Inorganic materials 0.000 claims description 2
- 125000001449 isopropyl group Chemical group [H]C([H])([H])C([H])(*)C([H])([H])[H] 0.000 claims description 2
- 229910044991 metal oxide Inorganic materials 0.000 claims description 2
- 150000004706 metal oxides Chemical class 0.000 claims description 2
- 150000002739 metals Chemical class 0.000 claims description 2
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 claims description 2
- 150000004767 nitrides Chemical class 0.000 claims description 2
- 229910052698 phosphorus Inorganic materials 0.000 claims description 2
- 229920001490 poly(butyl methacrylate) polymer Polymers 0.000 claims description 2
- 229920003229 poly(methyl methacrylate) Polymers 0.000 claims description 2
- 229920002857 polybutadiene Polymers 0.000 claims description 2
- 229920000573 polyethylene Polymers 0.000 claims description 2
- 229920000193 polymethacrylate Polymers 0.000 claims description 2
- 229920002223 polystyrene Polymers 0.000 claims description 2
- 229920001343 polytetrafluoroethylene Polymers 0.000 claims description 2
- 238000000926 separation method Methods 0.000 claims description 2
- 229910052710 silicon Inorganic materials 0.000 claims description 2
- 229910052709 silver Inorganic materials 0.000 claims description 2
- 229910052720 vanadium Inorganic materials 0.000 claims description 2
- 229910052844 willemite Inorganic materials 0.000 claims description 2
- 229910052727 yttrium Inorganic materials 0.000 claims description 2
- 229910052725 zinc Inorganic materials 0.000 claims description 2
- 229940048053 acrylate Drugs 0.000 claims 4
- BTBUEUYNUDRHOZ-UHFFFAOYSA-N Borate Chemical compound [O-]B([O-])[O-] BTBUEUYNUDRHOZ-UHFFFAOYSA-N 0.000 claims 1
- 239000005084 Strontium aluminate Substances 0.000 claims 1
- 229910009372 YVO4 Inorganic materials 0.000 claims 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims 1
- 229910052593 corundum Inorganic materials 0.000 claims 1
- 229920006324 polyoxymethylene Polymers 0.000 claims 1
- 239000000377 silicon dioxide Substances 0.000 claims 1
- 235000012239 silicon dioxide Nutrition 0.000 claims 1
- 229910001845 yogo sapphire Inorganic materials 0.000 claims 1
- 239000010410 layer Substances 0.000 description 33
- 238000007639 printing Methods 0.000 description 13
- 238000009826 distribution Methods 0.000 description 12
- 230000005281 excited state Effects 0.000 description 7
- 238000012795 verification Methods 0.000 description 7
- 239000003086 colorant Substances 0.000 description 6
- 239000010408 film Substances 0.000 description 5
- 239000000976 ink Substances 0.000 description 5
- 239000003795 chemical substances by application Substances 0.000 description 4
- 239000000306 component Substances 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 3
- 230000008859 change Effects 0.000 description 3
- 230000008878 coupling Effects 0.000 description 3
- 238000010168 coupling process Methods 0.000 description 3
- 238000005859 coupling reaction Methods 0.000 description 3
- 239000013078 crystal Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000005284 excitation Effects 0.000 description 3
- 230000005283 ground state Effects 0.000 description 3
- 229920000642 polymer Polymers 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 239000002356 single layer Substances 0.000 description 3
- 150000001875 compounds Chemical class 0.000 description 2
- 238000000151 deposition Methods 0.000 description 2
- 229960004279 formaldehyde Drugs 0.000 description 2
- 235000019256 formaldehyde Nutrition 0.000 description 2
- 230000014759 maintenance of location Effects 0.000 description 2
- 229920000620 organic polymer Polymers 0.000 description 2
- 229960003742 phenol Drugs 0.000 description 2
- 238000005424 photoluminescence Methods 0.000 description 2
- 229920000136 polysorbate Polymers 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 238000009827 uniform distribution Methods 0.000 description 2
- 238000011179 visual inspection Methods 0.000 description 2
- 229910052684 Cerium Inorganic materials 0.000 description 1
- 241001663154 Electron Species 0.000 description 1
- 206010056740 Genital discharge Diseases 0.000 description 1
- 239000012963 UV stabilizer Substances 0.000 description 1
- 238000006887 Ullmann reaction Methods 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 238000004026 adhesive bonding Methods 0.000 description 1
- 230000003321 amplification Effects 0.000 description 1
- 239000002518 antifoaming agent Substances 0.000 description 1
- 238000013475 authorization Methods 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 239000003139 biocide Substances 0.000 description 1
- 239000000872 buffer Substances 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 238000005136 cathodoluminescence Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 229920006037 cross link polymer Polymers 0.000 description 1
- 238000005090 crystal field Methods 0.000 description 1
- 230000001186 cumulative effect Effects 0.000 description 1
- 230000009849 deactivation Effects 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 230000005670 electromagnetic radiation Effects 0.000 description 1
- 238000000295 emission spectrum Methods 0.000 description 1
- 239000000839 emulsion Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000011888 foil Substances 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- 229920000578 graft copolymer Polymers 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000007641 inkjet printing Methods 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 239000004973 liquid crystal related substance Substances 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 239000003550 marker Substances 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000005442 molecular electronic Methods 0.000 description 1
- 239000000178 monomer Substances 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 238000004321 preservation Methods 0.000 description 1
- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- 238000010008 shearing Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 239000004094 surface-active agent Substances 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
- 238000000904 thermoluminescence Methods 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- 238000005390 triboluminescence Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B42—BOOKBINDING; ALBUMS; FILES; SPECIAL PRINTED MATTER
- B42D—BOOKS; 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
- B42D25/00—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof
- B42D25/20—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof characterised by a particular use or purpose
- B42D25/29—Securities; Bank notes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B42—BOOKBINDING; ALBUMS; FILES; SPECIAL PRINTED MATTER
- B42D—BOOKS; 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
- B42D25/00—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof
-
- G—PHYSICS
- G07—CHECKING-DEVICES
- G07D—HANDLING OF COINS OR VALUABLE PAPERS, e.g. TESTING, SORTING BY DENOMINATIONS, COUNTING, DISPENSING, CHANGING OR DEPOSITING
- G07D7/00—Testing specially adapted to determine the identity or genuineness of valuable papers or for segregating those which are unacceptable, e.g. banknotes that are alien to a currency
- G07D7/003—Testing specially adapted to determine the identity or genuineness of valuable papers or for segregating those which are unacceptable, e.g. banknotes that are alien to a currency using security elements
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B42—BOOKBINDING; ALBUMS; FILES; SPECIAL PRINTED MATTER
- B42D—BOOKS; 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
- B42D25/00—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof
- B42D25/30—Identification or security features, e.g. for preventing forgery
- B42D25/36—Identification or security features, e.g. for preventing forgery comprising special materials
- B42D25/378—Special inks
- B42D25/387—Special inks absorbing or reflecting ultraviolet light
Landscapes
- Business, Economics & Management (AREA)
- Accounting & Taxation (AREA)
- Finance (AREA)
- Engineering & Computer Science (AREA)
- Computer Security & Cryptography (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Luminescent Compositions (AREA)
- Credit Cards Or The Like (AREA)
- Inks, Pencil-Leads, Or Crayons (AREA)
- Optical Filters (AREA)
Abstract
The invention relates to a safety and/or valuable document having a safety element, wherein the safety element has a photonic crystal arranged on a substrate in relation to an orientation defined on a surface of the substrate, and a luminescent substance. It is characterized in that an emission wavelength lambda of the luminescent substance, and a grid constant of the photonic crystal are aligned with each other and specified according to the formula lambda = m * 2 * d, wherein d is a distance between two lattice planes of the photonic crystal, and m is a positive integer.
Description
a Security and/or valuable document having a photonic crystal Field of the invention.
The invention relates to a s=ecurity and/or valuable document having a security element, wherein the security element has a photonic crystal arranged on a substrate with an orienta-tion defined in relation to a surface of the substrate, and a luminescent substance. The in-vention further relates to a method for the pro-duction thereof and to a method for the verifi-cation thereof.
Background of the invention and prior art.
In valuable and security printing, optically variable colors are established as good security features, since they can easily be verified without technical means. In the practice, such optically variable colors are for instance known from banknotes and documents. They cannot easily be reproduced, but verification for instance at a cash desk is often made by a quick glance only, so that only the presence of a color change is observed. Because of the plurality of colors and pigments, for instance liquid crys-tals or platelets or flakes, which have such ef-fects and are commercially available, impression forgeries are known, which are clearly different from the original color change colors, are how-
The invention relates to a s=ecurity and/or valuable document having a security element, wherein the security element has a photonic crystal arranged on a substrate with an orienta-tion defined in relation to a surface of the substrate, and a luminescent substance. The in-vention further relates to a method for the pro-duction thereof and to a method for the verifi-cation thereof.
Background of the invention and prior art.
In valuable and security printing, optically variable colors are established as good security features, since they can easily be verified without technical means. In the practice, such optically variable colors are for instance known from banknotes and documents. They cannot easily be reproduced, but verification for instance at a cash desk is often made by a quick glance only, so that only the presence of a color change is observed. Because of the plurality of colors and pigments, for instance liquid crys-tals or platelets or flakes, which have such ef-fects and are commercially available, impression forgeries are known, which are clearly different from the original color change colors, are how-
2 -ever not easily detectable by a layman.
Another widely used security system comprises the use of luminescent substances. In most docu-ments of valuable and security printing are found luminescences, since they are not repro-ducible with simple means (printer, copier) and require for verification a UV light source only.
It is however disadvantageous that in most cases a quick verification only according to the color impression is made, so that a luminescence can in part be imitated for instance with a text marker. For a precise investigation, on the other hand, expensive spectrometers are neces-sary, by means of which different luminescence wavelengths can be differentiated. Thereby, ma-chine verification is easy and reliable, but the equipment is substantial and thus expensive.
From the document WO 2006/045567 A2, a secu-rity and/or valuable document of the structure mentioned above is known. Herein, as a photonic crystal, a layer is used, which is composed of spheres with a tight monomodal diameter distri-bution, the spheres forming a close-packing of spheres, i.e. a crystal structure. The diameter of the spheres is in a range from 50 to 500 nm, so that for different components of the visible light different reflection conditions according to the Bragg's law at different lattice planes of the crystal result. Thereby, an optically variable color effect is obtained, namely when the security and/or valuable document is swiv-eled or viewed under changing viewing angles.
According to this prior art, the security and/or valuable document may additionally contain a lu-minescent substance. The diameter of the spheres
Another widely used security system comprises the use of luminescent substances. In most docu-ments of valuable and security printing are found luminescences, since they are not repro-ducible with simple means (printer, copier) and require for verification a UV light source only.
It is however disadvantageous that in most cases a quick verification only according to the color impression is made, so that a luminescence can in part be imitated for instance with a text marker. For a precise investigation, on the other hand, expensive spectrometers are neces-sary, by means of which different luminescence wavelengths can be differentiated. Thereby, ma-chine verification is easy and reliable, but the equipment is substantial and thus expensive.
From the document WO 2006/045567 A2, a secu-rity and/or valuable document of the structure mentioned above is known. Herein, as a photonic crystal, a layer is used, which is composed of spheres with a tight monomodal diameter distri-bution, the spheres forming a close-packing of spheres, i.e. a crystal structure. The diameter of the spheres is in a range from 50 to 500 nm, so that for different components of the visible light different reflection conditions according to the Bragg's law at different lattice planes of the crystal result. Thereby, an optically variable color effect is obtained, namely when the security and/or valuable document is swiv-eled or viewed under changing viewing angles.
According to this prior art, the security and/or valuable document may additionally contain a lu-minescent substance. The diameter of the spheres
- 3 -is however selected such that the desired opti-cally variable effects are obtained, and that completely independent from a potential lumines-cence.
Structures suitable for the production of photonic crystals are for instance described in the documents WO 03/025035 A2, US 4,391,928, EP
0 441 559 Bl and EP 0 955 323 Bl.
Luminescence radiation typically has no di-rectional characteristic, since the emitter cen-ters are statistically oriented within a coat-ing, ink or the like. From other technical sec-tors, for instance the technology of laser di-odes, it is known to generate directed lumines-cence radiation by using layer structures, the layers of which have a thickness, which leads to the reflection or forward amplification of the luminescence radiation in a defined direction in space. Such structures are less suitable for valuable and security printing because of the expensive production.
Technical object of the invention.
It is therefore the technical object of the invention to provide a security element, which can be verified easily with minimum means, but increased reliability, also at a quick glance.
Basics of the invention.
For achieving this technical object, the in-vention teaches that an emission wavelength
Structures suitable for the production of photonic crystals are for instance described in the documents WO 03/025035 A2, US 4,391,928, EP
0 441 559 Bl and EP 0 955 323 Bl.
Luminescence radiation typically has no di-rectional characteristic, since the emitter cen-ters are statistically oriented within a coat-ing, ink or the like. From other technical sec-tors, for instance the technology of laser di-odes, it is known to generate directed lumines-cence radiation by using layer structures, the layers of which have a thickness, which leads to the reflection or forward amplification of the luminescence radiation in a defined direction in space. Such structures are less suitable for valuable and security printing because of the expensive production.
Technical object of the invention.
It is therefore the technical object of the invention to provide a security element, which can be verified easily with minimum means, but increased reliability, also at a quick glance.
Basics of the invention.
For achieving this technical object, the in-vention teaches that an emission wavelength
4 -lambda of the luminescent substance, and a grid constant of the photonic crystal are aligned with each other and specified according to the formula lambda = m * 2 * d, wherein d is a distance between two lattice planes of the photonic crystal, and m is a posi-tive integer.
In other words, the particles, by which the photonic crystal is formed, are adjusted with regard to diameter and arrangement to the emis-sion wavelength such that the intensity of the luminescence radiation is different under dif-ferent viewing angles.
By the invention, a substantial improvement of the safe and simple verification of lumines-cent security elements is achieved. Then a veri-fying person needs only expose the security and/or valuable document to a radiation exciting the luminescence, for instance UV, and verify, i) whether luminescence is observed, and ii) if yes, whether the intensity thereof varies when the security and/or valuable document tilts.
Only when both criteria are met, the security and/or valuable document is accepted as real. A
luminescent security element according to the invention is not reproducible anymore with sim-ple means.
The invention benefits of the finding that a photonic crystal can also be used for providing the per se undirected luminescence radiation by refraction with an anisotropic distribution of the intensity in the solid angle.
-Definitions.
Security and/or valuable documents are for instance: identity cards, passports, access al-lowance cards, visas, control symbols, tickets,
In other words, the particles, by which the photonic crystal is formed, are adjusted with regard to diameter and arrangement to the emis-sion wavelength such that the intensity of the luminescence radiation is different under dif-ferent viewing angles.
By the invention, a substantial improvement of the safe and simple verification of lumines-cent security elements is achieved. Then a veri-fying person needs only expose the security and/or valuable document to a radiation exciting the luminescence, for instance UV, and verify, i) whether luminescence is observed, and ii) if yes, whether the intensity thereof varies when the security and/or valuable document tilts.
Only when both criteria are met, the security and/or valuable document is accepted as real. A
luminescent security element according to the invention is not reproducible anymore with sim-ple means.
The invention benefits of the finding that a photonic crystal can also be used for providing the per se undirected luminescence radiation by refraction with an anisotropic distribution of the intensity in the solid angle.
-Definitions.
Security and/or valuable documents are for instance: identity cards, passports, access al-lowance cards, visas, control symbols, tickets,
5 driver licenses, vehicle documents, banknotes, cheques, postage stamps, credit cards, chip cards and adhesive labels (e.g. for product pro-tection). Such security and/or valuable docu-ments typically comprise a substrate, a printing layer and optionally a transparent cover layer.
A substrate is a carrier structure, on which the printing layer with information, pictures, pat-terns and the like is applied. Materials for a substrate may be all usual materials on a paper and/or plastic basis.
A security element is a structural unit, which comprises at least one security feature. A
security element may be an independent struc-tural unit, which can be connected with a secu-rity and/or valuable document, for instance glued, it may however also be an integral compo-nent of a security and/or valuable document. An example for the former is for instance a visa to be glued on a security and/or valuable document.
An example for the latter is an areal construct integrated, for instance laminated, in a bank-note or an ID card. These are also layers or coatings, which are applied on a substrate.
A security feature is a structure, which can only be produced, reproduced, manipulated or modified with increased efforts (compared to simple copying) or not at all without authoriza-tion. For the purpose of the invention, the se-curity feature is formed by the compound struc-
A substrate is a carrier structure, on which the printing layer with information, pictures, pat-terns and the like is applied. Materials for a substrate may be all usual materials on a paper and/or plastic basis.
A security element is a structural unit, which comprises at least one security feature. A
security element may be an independent struc-tural unit, which can be connected with a secu-rity and/or valuable document, for instance glued, it may however also be an integral compo-nent of a security and/or valuable document. An example for the former is for instance a visa to be glued on a security and/or valuable document.
An example for the latter is an areal construct integrated, for instance laminated, in a bank-note or an ID card. These are also layers or coatings, which are applied on a substrate.
A security feature is a structure, which can only be produced, reproduced, manipulated or modified with increased efforts (compared to simple copying) or not at all without authoriza-tion. For the purpose of the invention, the se-curity feature is formed by the compound struc-
6 -ture of photonic crystal and luminescent sub-stance. The term compound structure denotes the optical coupling with adjustment of the distance of the lattice planes and emission wavelength.
The term luminescence signifies the emission of electromagnetic radiation, in particular in the IR, visible or UV range, in the course of a relaxation of an atomic or molecular electronic system from an excited state into an energeti-cally lower state, in general the electronic ground state. The previous excitation can be ef-fected by electrical energy or an electrical po-tential (elektroluminescence), impact of elec-trons (cathodoluminescence), impact of photons (photoluminescence), application of heat (ther-moluminescence) or friction (triboluminescence).
For the purpose of the invention, photolumines-cence is preferred. The luminescence comprises in particular the phosphorescence and the (photo)fluorescence.
Fluorescence is a radiating deactivation of excited states, wherein the transition from the excited state into an energetically lower state, for instance the ground state, is spin-allowed.
The retention time in the excited state typi-cally is approx. 10-8 s, i.e. the emission of the fluorescence radiation stops immediately after the end of the energy supply for the excitation.
Phosphorescence however is a spin-forbidden de-activation of excited states by intercombination processes. Therefore, the relaxation is weak and slow. The retention time in an excited state is several milliseconds to hours and correspond-
The term luminescence signifies the emission of electromagnetic radiation, in particular in the IR, visible or UV range, in the course of a relaxation of an atomic or molecular electronic system from an excited state into an energeti-cally lower state, in general the electronic ground state. The previous excitation can be ef-fected by electrical energy or an electrical po-tential (elektroluminescence), impact of elec-trons (cathodoluminescence), impact of photons (photoluminescence), application of heat (ther-moluminescence) or friction (triboluminescence).
For the purpose of the invention, photolumines-cence is preferred. The luminescence comprises in particular the phosphorescence and the (photo)fluorescence.
Fluorescence is a radiating deactivation of excited states, wherein the transition from the excited state into an energetically lower state, for instance the ground state, is spin-allowed.
The retention time in the excited state typi-cally is approx. 10-8 s, i.e. the emission of the fluorescence radiation stops immediately after the end of the energy supply for the excitation.
Phosphorescence however is a spin-forbidden de-activation of excited states by intercombination processes. Therefore, the relaxation is weak and slow. The retention time in an excited state is several milliseconds to hours and correspond-
7 -ingly long is the emission time of the phospho-rescence radiation.
The emission wavelength of a luminescent sub-stance is characteristic for the used substance and is determined by the energy difference be-tween excited state and the energetically lower electronic state, for instance the ground state.
The emission wavelength is the peak of the emis-sion intensity in an emission spectrum.
A luminescent substance contains atoms, molecules or particles, which are suitable for luminescence. With a luminescent substance, a luminescent color or ink can be produced, which contains the usual other components of colors or inks, such as binding agents, penetration agents, preservation agents, biocides, tensides, buffer substances, solvents (water and/or or-ganic solvents), filling materials, pigments, effect pigments, anti-foam agents, anti-deposi-tion agents, UV stabilizers, etc. Suitable ink formulations for different printing methods are well known to the average man skilled in the art, and luminescent substances used according to the invention are added in lieu of or in ad-dition to conventional dyes or pigments.
A radiation is typically functional for the excitation of the luminescence, when the wave-length of the radiation is smaller than the wavelength of the luminescence radiation. How-ever, a radiation with higher wavelength may also be functional, when the respective lumines-cent substance is capable of so called up-con-version processes.
ti
The emission wavelength of a luminescent sub-stance is characteristic for the used substance and is determined by the energy difference be-tween excited state and the energetically lower electronic state, for instance the ground state.
The emission wavelength is the peak of the emis-sion intensity in an emission spectrum.
A luminescent substance contains atoms, molecules or particles, which are suitable for luminescence. With a luminescent substance, a luminescent color or ink can be produced, which contains the usual other components of colors or inks, such as binding agents, penetration agents, preservation agents, biocides, tensides, buffer substances, solvents (water and/or or-ganic solvents), filling materials, pigments, effect pigments, anti-foam agents, anti-deposi-tion agents, UV stabilizers, etc. Suitable ink formulations for different printing methods are well known to the average man skilled in the art, and luminescent substances used according to the invention are added in lieu of or in ad-dition to conventional dyes or pigments.
A radiation is typically functional for the excitation of the luminescence, when the wave-length of the radiation is smaller than the wavelength of the luminescence radiation. How-ever, a radiation with higher wavelength may also be functional, when the respective lumines-cent substance is capable of so called up-con-version processes.
ti
8 -A lattice plane is defined in space by the Miller indices h, k, and l. The distance d is defined as the smallest distance of parallel lattice planes, i.e. of lattice planes having the same Miller indices.
A close-packing of spheres corresponds to a fcc (face centered cubic, cubic close-packing of spheres) or hcc or hcp (hexagonal close packed, hexagonal close-packing of spheres) lattice. The grid constant a is a = 20.s * D
, D being the diameter of the spheres, which is given as the distance of the next adjacent sphere centers.
The reflection condition according to Bragg's law is:
lambda = m * 2 * d wherein d is the distance between the lattice planes, and m is a positive integer (order), in particular 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. In the following, the calculations are made with m = 1 (15t order) .
d and a have the following relation:
d = a / ( h 2 + k 2 + 12) o.s For the relation between the emission wave-length lambda and the diameter D of the spheres follows:
D = [ (hz + k2 + 12) / 8] '5 * lambda or
A close-packing of spheres corresponds to a fcc (face centered cubic, cubic close-packing of spheres) or hcc or hcp (hexagonal close packed, hexagonal close-packing of spheres) lattice. The grid constant a is a = 20.s * D
, D being the diameter of the spheres, which is given as the distance of the next adjacent sphere centers.
The reflection condition according to Bragg's law is:
lambda = m * 2 * d wherein d is the distance between the lattice planes, and m is a positive integer (order), in particular 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. In the following, the calculations are made with m = 1 (15t order) .
d and a have the following relation:
d = a / ( h 2 + k 2 + 12) o.s For the relation between the emission wave-length lambda and the diameter D of the spheres follows:
D = [ (hz + k2 + 12) / 8] '5 * lambda or
9 -D = [n / 8]0'5 * lambda, when (h2 + k2 + 12) is replaced by n.
The term diameter D denotes the mean diameter of the spheres (or means distance of the next adjacent spheres), which is defined as the maxi-mum of a number-referred (monomodal) linear standardized density distribution. This density distribution is given by qr (x) = dQr /dx wherein qr is the density distribution, Qr(x) the cumulative sum distribution, referred to the number and dx is the diameter differential.
For the purpose of the invention, the density distribution should be as tight as possible, in order that clearly visible and reproducible an-gular dependencies occur when viewing. It is preferred, if the density distribution (in most cases similar to a Gauss distribution) has a width at half maximum of the density of less than 10 % of the (mean) diameter D, preferably less than 5 % of the diameter D, ideally less than 2 % of the diameter D.
If instead of spheres other particle shapes, such as platelets or small rods, are used, a tight size distribution in the above meaning is also important. Instead of the mean diameter D
then the mean equivalent diameter DA is used, which is calculated according to defined geomet-ric rules from the respective shape. In this case, too, a correspondingly tight distribution of the aspect ratio (different geometric exten-sions of a particle) is important.
-For the purpose of the invention, it will usually be provided that the photonic crystal has at the emission wavelength no complete band gap. Photonic crystals with complete band gap 5 are up to now only theoretically postulated and are characterized by that the light cannot prop-agate in any direction in space. For photonic crystals with incomplete band gap, as in par-ticular used for the purpose of the invention,
The term diameter D denotes the mean diameter of the spheres (or means distance of the next adjacent spheres), which is defined as the maxi-mum of a number-referred (monomodal) linear standardized density distribution. This density distribution is given by qr (x) = dQr /dx wherein qr is the density distribution, Qr(x) the cumulative sum distribution, referred to the number and dx is the diameter differential.
For the purpose of the invention, the density distribution should be as tight as possible, in order that clearly visible and reproducible an-gular dependencies occur when viewing. It is preferred, if the density distribution (in most cases similar to a Gauss distribution) has a width at half maximum of the density of less than 10 % of the (mean) diameter D, preferably less than 5 % of the diameter D, ideally less than 2 % of the diameter D.
If instead of spheres other particle shapes, such as platelets or small rods, are used, a tight size distribution in the above meaning is also important. Instead of the mean diameter D
then the mean equivalent diameter DA is used, which is calculated according to defined geomet-ric rules from the respective shape. In this case, too, a correspondingly tight distribution of the aspect ratio (different geometric exten-sions of a particle) is important.
-For the purpose of the invention, it will usually be provided that the photonic crystal has at the emission wavelength no complete band gap. Photonic crystals with complete band gap 5 are up to now only theoretically postulated and are characterized by that the light cannot prop-agate in any direction in space. For photonic crystals with incomplete band gap, as in par-ticular used for the purpose of the invention,
10 the propagation of the light is in contrast only possible in certain directions in space.
Embodiments of the invention.
In principle, the luminescent substance can emit in the IR, visible, or UV ranges. It is preferred, if the emission takes place in the visible range, since then a verification of the security and/or valuable document can be made by simple visual inspection.
The luminescent substance may comprise a lu-minescent dye and/or a luminescent pigment.
The luminescent dye may be selected from the group comprising "organic fluorescent dyes, naphthalimides, coumarins, xanthenes, thioxan-thenes, naphtholactams, azlactones, methines, oxazines, thiazines, and mixtures of two or more such different substances". The luminescent pig-ment may be selected from the group comprising "ZnS:Ag, Zn silicate, SiC, ZnS, CdS (activated with Cu or Mn), ZnS/CdS : Ag, ZnS : Cu,Al, Y202S :
Eu, Y203 : Eu, YVOq . Eu, Zn2SiO4 : Mn, CaVVO9, (Zn,Mg)F2 : Mn, MgSiO3 : Mn, ZnO : Zn, GdzO2S : Tb, Y202S : Tb, LaZOzS : Tb, BaFCl Eu, LaOBr : Tb, Mg e
Embodiments of the invention.
In principle, the luminescent substance can emit in the IR, visible, or UV ranges. It is preferred, if the emission takes place in the visible range, since then a verification of the security and/or valuable document can be made by simple visual inspection.
The luminescent substance may comprise a lu-minescent dye and/or a luminescent pigment.
The luminescent dye may be selected from the group comprising "organic fluorescent dyes, naphthalimides, coumarins, xanthenes, thioxan-thenes, naphtholactams, azlactones, methines, oxazines, thiazines, and mixtures of two or more such different substances". The luminescent pig-ment may be selected from the group comprising "ZnS:Ag, Zn silicate, SiC, ZnS, CdS (activated with Cu or Mn), ZnS/CdS : Ag, ZnS : Cu,Al, Y202S :
Eu, Y203 : Eu, YVOq . Eu, Zn2SiO4 : Mn, CaVVO9, (Zn,Mg)F2 : Mn, MgSiO3 : Mn, ZnO : Zn, GdzO2S : Tb, Y202S : Tb, LaZOzS : Tb, BaFCl Eu, LaOBr : Tb, Mg e
- 11 tungstenate, (Zn,Be) silicate:Mn, Cd borateMn, Calo (P09 ) 6F, Cl : Sb, Mn, (SrMg) zPz0-7 : Eu, Sr2P20V Sn, Sr4A114025 : Eu, YZSiO5 Ce, Tb, Y(P, V) 04 . Eu, BaMgzA110O27 : Eu, MaA111019 : Ce,Tb, and mixtures of two or more such different substances". Herein, the host lattice is placed before the ":" and a doping element is placed behind the ":".
It is preferred, if the luminescent substance is a fluorescent dye, which is selected from the group comprising "organic fluorescent dyes, naphthalimides, coumarins, xanthenes, thioxan-thenes, naphtholactams, azlactones, methines, oxazines, thiazines, and mixtures of two or more such different substances". With regard to fur-ther suitable and preferred fluorescent dyes, reference is made for instance to the documents Schwander et al., "Fluorescent Dyes" in Ull-mann's Encyclopedia of Industrial Chemistry, Wiley-VCH Verlag GmbH & Co. KGaA, 2002, WO 03 /
052025 A, WO 02 / 053677 A, EP 0147252 A, GB
2,258,659 and F.M. Winnik et al., Xerox Dis-closer Journal Vol. 17, No. 3, 1992, pages 161-162.
For the purpose of invention, advantageously two or more different luminescent substances can also be used, the different luminescent sub-stances having different emission wavelengths.
The term different emission wavelengths denotes a wavelength difference of at least 3 nm, 5 nm, 10 nm, 20 nm, or 30 nm, in the visible range.
Because of the different emission wavelengths, different angles result, at which the different colors of the luminescence can respectively be observed with particularly high or low inten-sity. The term high intensity denotes with re-
It is preferred, if the luminescent substance is a fluorescent dye, which is selected from the group comprising "organic fluorescent dyes, naphthalimides, coumarins, xanthenes, thioxan-thenes, naphtholactams, azlactones, methines, oxazines, thiazines, and mixtures of two or more such different substances". With regard to fur-ther suitable and preferred fluorescent dyes, reference is made for instance to the documents Schwander et al., "Fluorescent Dyes" in Ull-mann's Encyclopedia of Industrial Chemistry, Wiley-VCH Verlag GmbH & Co. KGaA, 2002, WO 03 /
052025 A, WO 02 / 053677 A, EP 0147252 A, GB
2,258,659 and F.M. Winnik et al., Xerox Dis-closer Journal Vol. 17, No. 3, 1992, pages 161-162.
For the purpose of invention, advantageously two or more different luminescent substances can also be used, the different luminescent sub-stances having different emission wavelengths.
The term different emission wavelengths denotes a wavelength difference of at least 3 nm, 5 nm, 10 nm, 20 nm, or 30 nm, in the visible range.
Because of the different emission wavelengths, different angles result, at which the different colors of the luminescence can respectively be observed with particularly high or low inten-sity. The term high intensity denotes with re-
- 12 -gard to an emission wavelength the maximum in-tensity to be observed. A low intensity then in contrast denotes a reduced intensity compared to the high intensity, for instance reduced by at least 5 %, 10 %, 20 %, 30 %, 50 %, or 80 %.
Thereby, a luminescence color change is gener-ated, when the security and/or valuable document tilts.
The photonic crystal is advantageously formed by an fcc or hcc lattice with a grid constant a, and wherein d = a / n '5 with n = 1 to 20, in particular 1 to 5, is, and wherein n is (h2 + k 2 + 12) with h, k, and 1 as Miller indices. The lattice points or particles of the photonic crystal may in principle have any shape, for in-stance as platelets or small rods. It is however preferred, if the lattice points or particles are configured as spheres.
Then it is particularly preferred, if the spheres are core-mantle particles, which are ar-ranged in a close-packing of spheres. The mean diameter to be adjusted of the spheres depends from the emission wavelength of the used lumi-nescent substance. The mean diameter of the spheres may be in the range from 270 to 5,000 nm, in particular from 270 to 2,500 nm, if the luminescent substance emits in the IR range (780 to 3,000 nm) . The mean diameter of the spheres may be in the range from 135 to 1,200 nm, in particular from 135 to 600 nm, if the lumines-cent substance emits in the visible range (380 to 780 nm). The mean diameter of the spheres may be in the range from 35 to 600 nm, in particular from 35 to 300 nm, if the luminescent substance emits in the UV range (100 to 380 nm).
Thereby, a luminescence color change is gener-ated, when the security and/or valuable document tilts.
The photonic crystal is advantageously formed by an fcc or hcc lattice with a grid constant a, and wherein d = a / n '5 with n = 1 to 20, in particular 1 to 5, is, and wherein n is (h2 + k 2 + 12) with h, k, and 1 as Miller indices. The lattice points or particles of the photonic crystal may in principle have any shape, for in-stance as platelets or small rods. It is however preferred, if the lattice points or particles are configured as spheres.
Then it is particularly preferred, if the spheres are core-mantle particles, which are ar-ranged in a close-packing of spheres. The mean diameter to be adjusted of the spheres depends from the emission wavelength of the used lumi-nescent substance. The mean diameter of the spheres may be in the range from 270 to 5,000 nm, in particular from 270 to 2,500 nm, if the luminescent substance emits in the IR range (780 to 3,000 nm) . The mean diameter of the spheres may be in the range from 135 to 1,200 nm, in particular from 135 to 600 nm, if the lumines-cent substance emits in the visible range (380 to 780 nm). The mean diameter of the spheres may be in the range from 35 to 600 nm, in particular from 35 to 300 nm, if the luminescent substance emits in the UV range (100 to 380 nm).
13 -The photonic crystal can be produced by depo-sition from the liquid phase by means of self-organization, for instance under pressure, as for the ink jet printing process. For instance the production of artificial opals of Si02 from solutions is well known.
It is particularly preferred, if the core-mantle particles comprise a core of an organic or inorganic core material and a mantle of a polymeric organic mantle material, the mantle material being flowable at an increased tempera-ture, however the core material not being flow-able at the increased temperature. The back-ground is that for the formation of a photonic crystal, the necessary periodic long-range structure, for instance the close-packing of spheres, must be produced in a defined orienta-tion. If a filling or emulsion or suspension with such core-mantle particles is exposed at an increased temperature to a pressure force, the shearing forces acting between the particles will cause that the particles will arrange and align to a close-packing of spheres on a surface of a substrate, if the particles can move with regard to each other. A mantle being flowable under the pressure and temperature conditions facilitates such organizational movements of the particles relative to each other, and a photonic crystal with excellent long-range and unique orientation on the substrate will result. In de-tail, there are different possibilities of exe-cution.
The inorganic core material can be selected from the group comprising "metals, semimetals, metal chalcogenides, in particular metal oxides, s t
It is particularly preferred, if the core-mantle particles comprise a core of an organic or inorganic core material and a mantle of a polymeric organic mantle material, the mantle material being flowable at an increased tempera-ture, however the core material not being flow-able at the increased temperature. The back-ground is that for the formation of a photonic crystal, the necessary periodic long-range structure, for instance the close-packing of spheres, must be produced in a defined orienta-tion. If a filling or emulsion or suspension with such core-mantle particles is exposed at an increased temperature to a pressure force, the shearing forces acting between the particles will cause that the particles will arrange and align to a close-packing of spheres on a surface of a substrate, if the particles can move with regard to each other. A mantle being flowable under the pressure and temperature conditions facilitates such organizational movements of the particles relative to each other, and a photonic crystal with excellent long-range and unique orientation on the substrate will result. In de-tail, there are different possibilities of exe-cution.
The inorganic core material can be selected from the group comprising "metals, semimetals, metal chalcogenides, in particular metal oxides, s t
14 -metal pnictides, in particular metal nitrides or metal phosphides, and mixtures of two or more such different substances, wherein the metal can be formed of an element of the first three main groups of the periodic table or of a metallic element of the side groups and wherein the semi-metal may comprise Si, Ge, As, Sb, and Bi", is in particular selected from the group comprising "Si02, Ti02, Zr02, Sn02 and A1203"
Preferably, the organic core material is se-lected from the group comprising "aliphatic, aliphatic/aromatic or fully aromatic polyesters, polyamides, polycarbonates, polyurea, polyure-thanes, aminoplast resins, phenoplast resins, such as for instance formaldehyde condensates of melamine, urea or phenol, epoxide resins, acryl-esters, such as methyl (meth)acrylate, butyl (meth)acrylate, isopropyl (meth)acrylate, poly-styrene, PVC, polyacrylnitrile, random or block copolymerisates of one or several such homopoly-mers, and mixtures of two or more such different homopolymers or copolymers".
The mantle material may be selected from the group comprising "aliphatic, aliphatic/aromatic or fully aromatic polyesters, polyamides, poly-carbonates, polyurea, polyurethanes, aminoplast resins, phenoplast resins, as for instance form-aldehyde condensates of melamine, urea or phe-nol, epoxide resins, polyepoxides, poly (meth)-acrylate, such as polymethyl (meth)acrylate, polybutyl (meth)acrylate, polyisopropyl (meth)-acrylate, polystyrene, PVC, polyacrylnitrile, polyethylene, polypropylene, polyethylene oxide, polybutadiene, polytetrafluorethylene, polyoxy-methylene, caoutchouc, polyisoprene, random or
Preferably, the organic core material is se-lected from the group comprising "aliphatic, aliphatic/aromatic or fully aromatic polyesters, polyamides, polycarbonates, polyurea, polyure-thanes, aminoplast resins, phenoplast resins, such as for instance formaldehyde condensates of melamine, urea or phenol, epoxide resins, acryl-esters, such as methyl (meth)acrylate, butyl (meth)acrylate, isopropyl (meth)acrylate, poly-styrene, PVC, polyacrylnitrile, random or block copolymerisates of one or several such homopoly-mers, and mixtures of two or more such different homopolymers or copolymers".
The mantle material may be selected from the group comprising "aliphatic, aliphatic/aromatic or fully aromatic polyesters, polyamides, poly-carbonates, polyurea, polyurethanes, aminoplast resins, phenoplast resins, as for instance form-aldehyde condensates of melamine, urea or phe-nol, epoxide resins, polyepoxides, poly (meth)-acrylate, such as polymethyl (meth)acrylate, polybutyl (meth)acrylate, polyisopropyl (meth)-acrylate, polystyrene, PVC, polyacrylnitrile, polyethylene, polypropylene, polyethylene oxide, polybutadiene, polytetrafluorethylene, polyoxy-methylene, caoutchouc, polyisoprene, random or
15 -block copolymerisates of one or several such homopolymers, and mixtures of two or more such different homopolymers or copolymers".
It is suitable, if the core material has a higher glass temperature than the mantle mate-rial, since then at a temperature between the glass temperatures of the materials, only the mantle material and not the core material will flow. The core material may for instance have a glass temperature in the range of more than 60 C, preferably more than 80 C, most preferably more than 90 C, whereas the mantle material may for instance have a glass temperature in the range from 40 to 90 C, in particular from 60 to 80 C. Such ranges of the glass temperatures are recommended for instance for core materials of organic polymer. Alternatively, for instance in the case of inorganic core materials, the glass temperature of the core material may be above 300 C, and then the glass temperature of the mantle area, for instance in the case of poly-carbonates, may also be high, for instance in the range from 80 to 250 C, in particular 120 to 200 C.
The mantle material, which during the produc-tion of the photonic crystal may form a matrix, in which the spheres or cores are embedded (and fixed), should have a refractive index being different from the refractive index of the core material. The term different refractive indices denotes a difference of at least 0.001, better at least 0.01, advantageously at least 0.1. The man skilled in the art can easily select, from the above substances for the core material and the mantle material, suitable substance pairs
It is suitable, if the core material has a higher glass temperature than the mantle mate-rial, since then at a temperature between the glass temperatures of the materials, only the mantle material and not the core material will flow. The core material may for instance have a glass temperature in the range of more than 60 C, preferably more than 80 C, most preferably more than 90 C, whereas the mantle material may for instance have a glass temperature in the range from 40 to 90 C, in particular from 60 to 80 C. Such ranges of the glass temperatures are recommended for instance for core materials of organic polymer. Alternatively, for instance in the case of inorganic core materials, the glass temperature of the core material may be above 300 C, and then the glass temperature of the mantle area, for instance in the case of poly-carbonates, may also be high, for instance in the range from 80 to 250 C, in particular 120 to 200 C.
The mantle material, which during the produc-tion of the photonic crystal may form a matrix, in which the spheres or cores are embedded (and fixed), should have a refractive index being different from the refractive index of the core material. The term different refractive indices denotes a difference of at least 0.001, better at least 0.01, advantageously at least 0.1. The man skilled in the art can easily select, from the above substances for the core material and the mantle material, suitable substance pairs
16 -with regard to the difference of the refractive indices. The core material, but also the mantle material may have the respectively higher re-fractive index.
The weight ratio of core material and mantle material may be in the range from 2:1 to 1:5, in particular in the range from 3:2 to 1:3. Pref-erably, this ratio is in the case of polymeric materials for both materials not larger than 2:3.
Between core and mantle of a core-mantle par-ticle, a coupling layer may be provided. For this purpose, for instance cross-linked or par-tially cross-linked organic polymers can be used. Alternatively, the surface of the core can be functionalized in a conventional manner for a binding or adhesion of the mantle material.
The production of core-mantle particles suit-able for the production of photonic crystals is for instance described in the prior art men-tioned above, same as further variants and de-tails for core materials, mantle materials, cou-pling layers, etc. Reference is explicitly made to this prior art.
Photonic crystals to be used according to the invention may be films, layers or foils. Corre-spondingly, they can be applied with usual coat-ing methods, or adhesion mediators on a sub-strate. Herein, they may form an integral part of a document, for instance in the case of card structures.
Photonic crystals according to the invention
The weight ratio of core material and mantle material may be in the range from 2:1 to 1:5, in particular in the range from 3:2 to 1:3. Pref-erably, this ratio is in the case of polymeric materials for both materials not larger than 2:3.
Between core and mantle of a core-mantle par-ticle, a coupling layer may be provided. For this purpose, for instance cross-linked or par-tially cross-linked organic polymers can be used. Alternatively, the surface of the core can be functionalized in a conventional manner for a binding or adhesion of the mantle material.
The production of core-mantle particles suit-able for the production of photonic crystals is for instance described in the prior art men-tioned above, same as further variants and de-tails for core materials, mantle materials, cou-pling layers, etc. Reference is explicitly made to this prior art.
Photonic crystals to be used according to the invention may be films, layers or foils. Corre-spondingly, they can be applied with usual coat-ing methods, or adhesion mediators on a sub-strate. Herein, they may form an integral part of a document, for instance in the case of card structures.
Photonic crystals according to the invention
17 -may represent a visible pattern, for instance the contour of an object or a person, or a se-quence of letters and/or numbers. Bar codes may also be used as patterns. Then the coating is performed with a corresponding printing method, or a film is correspondingly cut out . It is un-derstood that a photonic crystal may also be formed in a macroscopically isotropic manner, i.e. without pattern.
For the arrangement of the luminescent sub-stance there are different possibilities. The luminescent substance may be arranged in the particles of the photonic crystal. In the case of core-mantle particles, an arrangement in the core material and/or in the mantle material of the core-mantle particles is possible. For this purpose, in the case of an organic core mate-rial, the respective material is mixed before the solidification or polymerization during the production of the particles with the luminescent substance in a preferably homogeneous manner. In the case of an inorganic core material, a doping producing the luminescence, for instance with rare earth elements, may be made, which are in-tegrated in the host lattice of the core mate-rial. Then the photonic crystal can be produced without addition of luminescent particles, thereby disturbances of the creation of the pho-tonic crystal because of the presence of inter-stitial luminescent particles being safely avoided.
In the case of polymeric materials for core and/or mantle sections of the core-mantle parti-cles, the respective polymer may comprise lumi-nescent monomer components, and that regularly,
For the arrangement of the luminescent sub-stance there are different possibilities. The luminescent substance may be arranged in the particles of the photonic crystal. In the case of core-mantle particles, an arrangement in the core material and/or in the mantle material of the core-mantle particles is possible. For this purpose, in the case of an organic core mate-rial, the respective material is mixed before the solidification or polymerization during the production of the particles with the luminescent substance in a preferably homogeneous manner. In the case of an inorganic core material, a doping producing the luminescence, for instance with rare earth elements, may be made, which are in-tegrated in the host lattice of the core mate-rial. Then the photonic crystal can be produced without addition of luminescent particles, thereby disturbances of the creation of the pho-tonic crystal because of the presence of inter-stitial luminescent particles being safely avoided.
In the case of polymeric materials for core and/or mantle sections of the core-mantle parti-cles, the respective polymer may comprise lumi-nescent monomer components, and that regularly,
18 -statically, block-wise or as side chains (graft copolymers). Further, in the case of a cross-linked polymer, the cross-linkage means may be luminescent. Finally, luminescent substances may be bound to the polymeric chain in a covalent, ionic or complexed manner.
The luminescent substance may however also be arranged between the particles of the photonic lattice. In the case of pigments, it is recom-mendable, if the ratio of the diameter Dp of the pigment particles and the diameter D (or DA) of the particles of the photonic lattice, Dp/D (or Dp/DA), is smaller than 0.5, preferably smaller than 0.1, most preferably smaller than 0.02.
Then the pigment particles can be arranged be-tween the particles or spheres of the photonic crystal and damages to the particles or spheres by pressure actions is practically excluded. If the luminescent substance is a luminescent dye, it can anyway freely distribute itself between the particles of the photonic lattice, without disturbing these particles or their arrangement.
In either case, the production of the photonic crystal is achieved by mixture of particles of the photonic crystal with the luminescent sub-stance and subsequent formation of the long-range order to a crystal, as described above. A
variant of this is, if the luminescent substance is deposited on the surface of the particles of the photonic crystal, for instance by layer-by-layer absorption. Thereby, a uniform growth on the particles of the photonic crystal is achieved, with the consequence of maintaining the tight density distribution. It is advanta-geous, herein, that the particles of the photonic crystal and the luminescent substance
The luminescent substance may however also be arranged between the particles of the photonic lattice. In the case of pigments, it is recom-mendable, if the ratio of the diameter Dp of the pigment particles and the diameter D (or DA) of the particles of the photonic lattice, Dp/D (or Dp/DA), is smaller than 0.5, preferably smaller than 0.1, most preferably smaller than 0.02.
Then the pigment particles can be arranged be-tween the particles or spheres of the photonic crystal and damages to the particles or spheres by pressure actions is practically excluded. If the luminescent substance is a luminescent dye, it can anyway freely distribute itself between the particles of the photonic lattice, without disturbing these particles or their arrangement.
In either case, the production of the photonic crystal is achieved by mixture of particles of the photonic crystal with the luminescent sub-stance and subsequent formation of the long-range order to a crystal, as described above. A
variant of this is, if the luminescent substance is deposited on the surface of the particles of the photonic crystal, for instance by layer-by-layer absorption. Thereby, a uniform growth on the particles of the photonic crystal is achieved, with the consequence of maintaining the tight density distribution. It is advanta-geous, herein, that the particles of the photonic crystal and the luminescent substance
19 -can be selected and modified independently from each other, thus an easier adjustment to differ-ent products of valuable and security printing being possible.
Alternatively, the photonic crystal can also be underlaid with the luminescent substance. For instance, the substrate can be coated, for in-stance imprinted with a dye or an ink, which comprises the luminescent substance. Then the application of the photonic crystal is made on the coating, for instance in the simplest case as a film. This variant is technologically the simplest one and also permits in this way modi-fications of the system luminescent substance /
photonic crystal, for instance for different types or values of security and/or valuable documents.
Finally, it is possible that in the photonic crystal and/or in a layer comprising the lumi-nescent substance, additional non-luminescent coloration means, such as dyes or pigments, are provided. For this purpose, all coloration means being usual in the sector of the security and/or valuable documents and being known to the aver-age man skilled in the art, can be used.
Equally, conventional forensic characteristic substances can be provided in the photonic crys-tal or another layer of the security and/or valuable document.
The invention further relates to a method for producing a security and/or valuable document according to the invention or a security element therefor, wherein a substrate is provided on a surface or partial surface with a coating com-
Alternatively, the photonic crystal can also be underlaid with the luminescent substance. For instance, the substrate can be coated, for in-stance imprinted with a dye or an ink, which comprises the luminescent substance. Then the application of the photonic crystal is made on the coating, for instance in the simplest case as a film. This variant is technologically the simplest one and also permits in this way modi-fications of the system luminescent substance /
photonic crystal, for instance for different types or values of security and/or valuable documents.
Finally, it is possible that in the photonic crystal and/or in a layer comprising the lumi-nescent substance, additional non-luminescent coloration means, such as dyes or pigments, are provided. For this purpose, all coloration means being usual in the sector of the security and/or valuable documents and being known to the aver-age man skilled in the art, can be used.
Equally, conventional forensic characteristic substances can be provided in the photonic crys-tal or another layer of the security and/or valuable document.
The invention further relates to a method for producing a security and/or valuable document according to the invention or a security element therefor, wherein a substrate is provided on a surface or partial surface with a coating com-
20 -prising the particles of the photonic crystal to be formed, and this coating is condensed under simultaneous exposure to heat and pressure, op-tionally before coating with the particles, a luminescent layer comprising the luminescent substance being applied to the substrate, and/or the particles comprising the luminescent sub-stance or being mixed therewith. In this embodi-ment of a production method, the formation of the photonic crystal occurs with the condensa-tion.
Preferably, the exposure to heat takes place with a temperature in the range from 60 to 260 C, in particular from 70 to 190 C, and for a time from 0.5 to 7,200 s, preferably from 0.5 to 3,600 s, most preferably from 1 to 10 s. The condensation can be performed with a pressure from 1 to 100 bars, preferably from 1 to 20 bars. Typically, the condensation is achieved by means of a press, in particular a lamination press. In the case of an inorganic core material in connection with a polymer having a high glass temperature as mantle material, for instance in the range from 80 to 250 C, the exposure to heat is made at a correspondingly higher tem-perature, for instance at 140 to 250 C.
On the coating with particles of the photonic crystal, a separation and/or protection layer can be arranged. The protection layer can be welded during the exposure to heat and pressure to the substrate, if applicable to the lumines-cent layer, and to the layer with particles or can be laminated so to form a layer system. The protection layer should be transparent, referred to the emission wavelength lambda.
.
Preferably, the exposure to heat takes place with a temperature in the range from 60 to 260 C, in particular from 70 to 190 C, and for a time from 0.5 to 7,200 s, preferably from 0.5 to 3,600 s, most preferably from 1 to 10 s. The condensation can be performed with a pressure from 1 to 100 bars, preferably from 1 to 20 bars. Typically, the condensation is achieved by means of a press, in particular a lamination press. In the case of an inorganic core material in connection with a polymer having a high glass temperature as mantle material, for instance in the range from 80 to 250 C, the exposure to heat is made at a correspondingly higher tem-perature, for instance at 140 to 250 C.
On the coating with particles of the photonic crystal, a separation and/or protection layer can be arranged. The protection layer can be welded during the exposure to heat and pressure to the substrate, if applicable to the lumines-cent layer, and to the layer with particles or can be laminated so to form a layer system. The protection layer should be transparent, referred to the emission wavelength lambda.
.
21 -Alternatively to the above procedure, a secu-rity and/or valuable document according to the invention can also be produced by that a fin-ished photonic crystal, in particular in the form of a film (thickness e.g. 0.I to 500 um), is positioned on the substrate and connected therewith, either by gluing or by laminating.
Herein, too, the luminescent substance can al-ready be present in the photonic crystal. It is however possible here, too, that before the sub-strate is provided with a separate coating, for instance a printing layer, comprising the lumi-nescent substance.
The invention further relates to a security and/or valuable document, which is obtainable with an above method according to the invention.
Finally, the invention relates to a method for verifying a security and/or valuable docu-ment or security element according to the inven-tion, wherein the luminescent substance is ex-cited to the emission of a luminescence radia-tion, for instance by exposure to UV radiation, the intensity of the luminescence radiation be-ing determined in dependence on the angle with respect to the surface of the security and/or valuable document, and the determined angular dependency of the luminescence radiation being compared to a given angular dependency. If no angular dependency is determined, or the deter-mined angular dependency is not in agreement with the given angular dependency, then it is not a security and/or valuable document accord-ing to the invention and consequently it is a reproduction. In case of agreement of the deter-mined angular dependency with the given angular
Herein, too, the luminescent substance can al-ready be present in the photonic crystal. It is however possible here, too, that before the sub-strate is provided with a separate coating, for instance a printing layer, comprising the lumi-nescent substance.
The invention further relates to a security and/or valuable document, which is obtainable with an above method according to the invention.
Finally, the invention relates to a method for verifying a security and/or valuable docu-ment or security element according to the inven-tion, wherein the luminescent substance is ex-cited to the emission of a luminescence radia-tion, for instance by exposure to UV radiation, the intensity of the luminescence radiation be-ing determined in dependence on the angle with respect to the surface of the security and/or valuable document, and the determined angular dependency of the luminescence radiation being compared to a given angular dependency. If no angular dependency is determined, or the deter-mined angular dependency is not in agreement with the given angular dependency, then it is not a security and/or valuable document accord-ing to the invention and consequently it is a reproduction. In case of agreement of the deter-mined angular dependency with the given angular
22 -dependency, the security and/or valuable docu-ment is verified as being according to the in-vention and consequently real. The determination can in the simplest case be made by means of visual inspection. It is however also possible to determine the angular dependency by machine.
In the case of different luminescent substances, the determination is performed for the respec-tive emission wavelengths, for which different angular dependencies are given.
In the following, the invention is described in more detail with reference to embodiments representing examples of execution only.
Example 1: Different forms of construction of a security and/or valuable document according to the invention.
In Figure 1, cross sections of different variants of security and/or valuable documents according to the invention are shown.
In Figure la can be seen a substrate 1, which can be single-layer or multi-layer. On this sub-strate is immediately applied a printing layer 2, which contains two different fluorescent sub-stances in a uniform distribution. A first fluo-rescent substance has an emission wavelength of 500 nm, and a second fluorescent substance has an emission wavelength of 707 nm. In the layer sequence then follows a photonic crystal 3 con-figured as a film. This photonic crystal 3 is formed of core-mantle particles according to the document WO 2003/025035 A2. The core-mantle par-ticles have a mean diameter of the particles of
In the case of different luminescent substances, the determination is performed for the respec-tive emission wavelengths, for which different angular dependencies are given.
In the following, the invention is described in more detail with reference to embodiments representing examples of execution only.
Example 1: Different forms of construction of a security and/or valuable document according to the invention.
In Figure 1, cross sections of different variants of security and/or valuable documents according to the invention are shown.
In Figure la can be seen a substrate 1, which can be single-layer or multi-layer. On this sub-strate is immediately applied a printing layer 2, which contains two different fluorescent sub-stances in a uniform distribution. A first fluo-rescent substance has an emission wavelength of 500 nm, and a second fluorescent substance has an emission wavelength of 707 nm. In the layer sequence then follows a photonic crystal 3 con-figured as a film. This photonic crystal 3 is formed of core-mantle particles according to the document WO 2003/025035 A2. The core-mantle par-ticles have a mean diameter of the particles of
23 -354 nm. To the photonic crystal 3 then follows a protection layer 4 being transparent for visible light, which in turn may be single-layer or multi-layer. It is also possible that between the printing layer 2 and the photonic crystal 3, a single-layer or multi-layer intermediate layer is arranged, which is not shown for clarity rea-sons. The substrate 1 with the printing layer 2, the photonic crystal 3 and the protection layer 4 are connected to each other by lamination and form a monolithic layer block.
In the variant of Figure ib, the same fluo-rescent substances are used, which are however arranged in the photonic crystal 3. Thereby, the printing layer 2 is not needed. The fluorescent substances are absorbed or adsorbed at the sur-face of the core-mantle particles, in a uniform distribution.
Example 2 Angular dependency of the fluores-cence of the subject matter of Exam-ple l.
When adjusting the emission wavelengths to the diameter of the particles of the photonic crystal 3, and thus ultimately also to the grid constant a and the distance d of the lattice planes of the photonic crystal 3, it results that red (707 nm) is emitted with a maximum in-tensity at approx. 45 with respect to the sur-face normal of the security and/or valuable document, however at 0 and 90 the intensity is strongly reduced, typically below 90 % of the maximum intensity. In contrast, green (500 nm) can be observed at 45 with only 10 % or less of s
In the variant of Figure ib, the same fluo-rescent substances are used, which are however arranged in the photonic crystal 3. Thereby, the printing layer 2 is not needed. The fluorescent substances are absorbed or adsorbed at the sur-face of the core-mantle particles, in a uniform distribution.
Example 2 Angular dependency of the fluores-cence of the subject matter of Exam-ple l.
When adjusting the emission wavelengths to the diameter of the particles of the photonic crystal 3, and thus ultimately also to the grid constant a and the distance d of the lattice planes of the photonic crystal 3, it results that red (707 nm) is emitted with a maximum in-tensity at approx. 45 with respect to the sur-face normal of the security and/or valuable document, however at 0 and 90 the intensity is strongly reduced, typically below 90 % of the maximum intensity. In contrast, green (500 nm) can be observed at 45 with only 10 % or less of s
24 -the maximum intensity, however at 0 and 90 with maximum intensity.
The representation of Figure 2a is obtained, which is a projection of the hemisphere shown in perspective in Figure 2b in the direction of the surface normal of the security and/or valuable document. Sections R can be seen, which appear in red at approx. 45 , whereas the sections G
appear in green at approx. 90 and 0 .
The representation of Figure 2a is obtained, which is a projection of the hemisphere shown in perspective in Figure 2b in the direction of the surface normal of the security and/or valuable document. Sections R can be seen, which appear in red at approx. 45 , whereas the sections G
appear in green at approx. 90 and 0 .
Claims (30)
1. A security and/or valuable document having a security element, wherein the security element has a photonic crystal arranged on a substrate with an orientation defined in relation to a surface of the substrate, and a luminescent sub-stance, characterized in that an emission wavelength lambda of the lumi-nescent substance and a grid constant of the photonic crystal are aligned with each other and specified according to the formula lambda = m * 2 * d wherein d is a distance between two lattice planes of the photonic crystal, and m is a posi-tive integer.
2. The security and/or valuable document ac-cording to claim 1, wherein the luminescent sub-stance emits in the IR, visible, or UV range.
3. The security and/or valuable document ac-cording to claim 1 or 2, wherein the luminescent substance comprises a luminescent dye and/or a luminescent pigment.
4. The security and/or valuable document ac-cording to claim 3, wherein the luminescent dye is selected from the group comprising "organic fluorescent dyes, naphthalimides, coumarins, xanthenes, thioxanthenes, naphtholactams, azlac-tones, methines, oxazines, thiazines, and mix-tures of two or more such different substances", and/or wherein the luminescent pigment is se-lected from the group comprising "ZnS : Ag, Zn silicate, SiC, ZnS, CdS (activated with Cu or Mn) , ZnS/CdS : Ag, ZnS : Cu, Al, Y2O2S : Eu, Y2O3 : Eu, YVO4 : Eu, Zn2SiO4 : Mn, CaVVO4, (Zn,Mg)F2 : Mn, MgSiO3 : Mn, ZnO : Zn, Gd2O2S : Tb, Y2O2S : Tb, La2O2S
Tb, BaFCl:Eu, LaOBr:Tb, Mg tungstenate, (Zn,Be) silicate : Mn, Cd borate Mn, Ca10 (PO4) 6F, Cl : Sb, Mn, (SrMg)2P2O7 : Eu, Sr2P2O7 : Sn, Sr4Al14O25 : Eu, Y2SiO5 Ce,Tb, Y(P, V) O4 : Eu, BaMg2Al10O27 : Eu, MaAl11O19 Ce,Tb, and mixtures of two or more such differ-ent substances".
Tb, BaFCl:Eu, LaOBr:Tb, Mg tungstenate, (Zn,Be) silicate : Mn, Cd borate Mn, Ca10 (PO4) 6F, Cl : Sb, Mn, (SrMg)2P2O7 : Eu, Sr2P2O7 : Sn, Sr4Al14O25 : Eu, Y2SiO5 Ce,Tb, Y(P, V) O4 : Eu, BaMg2Al10O27 : Eu, MaAl11O19 Ce,Tb, and mixtures of two or more such differ-ent substances".
5. The security and/or valuable document ac-cording to one of claims 1 to 4, wherein the lu-minescent substance is a fluorescent dye, which is selected from the group comprising "organic fluorescent dyes, naphthalimides, coumarins, xanthenes, thioxanthenes, naphtholactams, azlac-tones, methines, oxazines, thiazines, and mix-tures of two or more such different substances".
6. The security and/or valuable document ac-cording to one of claims 1 to 5, wherein the photonic crystal is formed by an fcc or hcc lat-tice with a grid constant a, and wherein d = a /
n0.5 with n = 1 to 20, in particular 1 to 5, is, and wherein n is (h2 + k2 + l2) with h, k, and l as Miller indices.
n0.5 with n = 1 to 20, in particular 1 to 5, is, and wherein n is (h2 + k2 + l2) with h, k, and l as Miller indices.
7. The security and/or valuable document ac-cording to one of claims 1 to 6, wherein the lattice points of the photonic crystal are configured by means of spheres or the centers thereof.
8. The security and/or valuable document ac-cording to one of claims 1 to 7, wherein the spheres are core-mantle particles, which are ar-ranged in a close-packing of spheres.
9. The security and/or valuable document ac-cording to claim 8, wherein the mean diameter of the spheres is in the range from 270 to 5,000 nm, in particular from 270 to 2,500 nm, if the luminescent substance emits in the IR range (780 to 3,000 nm).
10. The security and/or valuable document ac-cording to claim 8, wherein the mean diameter of the spheres is in the range from 135 to 1,200 nm, in particular from 135 to 600 nm, if the lu-minescent substance emits in the visible range (380 to 780 nm).
11. The security and/or valuable document ac-cording to claim 8, wherein the mean diameter of the spheres is in the range from 35 to 600 nm, in particular from 35 to 300 nm, if the lumines-cent substance emits in the UV range (100 to 380 nm)
12. The security and/or valuable document ac-cording to one of claims 8 to 11, wherein the core-mantle particles comprise a core of an or--ganic or inorganic core material and a mantle of a polymeric organic mantle material, the mantle material being flowable at an increased tempera-ture, however the core material not being flow-able at the increased temperature.
13. The security and/or valuable document ac--cording to claim 12, wherein the organic core material is selected from the group comprising "aliphatic, aliphatic/aromatic or fully aromatic polyesters, polyamides, polycarbonates, poly--urea, polyurethanes, aminoplast resins, pheno--plast resins, such as for instance formaldehyde condensates of melamine, urea or phenol, epoxide resins, acrylesters, such as methyl (meth)acry-late, butyl (meth)acrylate, isopropyl (meth)acry--late, polystyrene, PVC, polyacrylnitrile, random or block copolymerisates of one or several such homopolymers, and mixtures of two or more such different homopolymers or copolymers".
14. The security and/or valuable document ac--cording to claim 12, wherein the inorganic core material is selected from the group comprising "metals, semimetals, metal chalcogenides, in particular metal oxides, metal pnictides, in particular metal nitrides or metal phosphides, and mixtures of two or more such different sub--stances, wherein the metal can be formed of an element of the first three main groups of the periodic table or of a metallic element of the side groups and wherein the semimetal may com-prise Si, Ge, As, Sb, and Bi", is in particular selected from the group comprising "SiO2, TiO2, ZrO2, SnO2 and Al2O3".
15. The security and/or valuable document ac--cording to one of claims 12 to 14, wherein the core material has a glass temperature in the range of more than 60 °C, preferably more than 80 °C, most preferably more than 90 °C, or wherein the core material has a glass tempera-ture of more than 300 °C.
16. The security and/or valuable document ac-cording to one of claims 12 to 15, wherein the mantle material is selected from the group com-prising "aliphatic, aliphatic/aromatic or fully aromatic polyesters, polyamides, polycarbonates, polyurea, polyurethanes, aminoplast resins, phenoplast resins, as for instance formaldehyde condensates of melamine, urea or phenol, epoxide resins, polyepoxides, poly(meth)acrylate, such as polymethyl (meth)acrylate, polybutyl (meth)-acrylate, polyisopropyl (meth)acrylate, polysty-rene, PVC, polyacrylnitrile, polyethylene, poly-propylene, polyethylene oxide, polybutadiene, polytetrafluorethylene, polyoxymethylene, caout-chouc, polyisoprene, random or block copolymer-isates of one or several such homopolymers, and mixtures of two or more such different homopoly-mers or copolymers", and wherein the mantle ma-terial has a glass temperature in the range from 40 to 90 °C, in particular from 60 to 80 °C, or in the range from 80 to 250 °C.
17. The security and/or valuable document ac-cording to one of claims 1 to 16, wherein the luminescent substance is arranged in the pho-tonic crystal.
18. The security and/or valuable document ac-cording to claim 17, wherein the luminescent substance is arranged in the particles of the photonic crystal, in particular in the core ma-terial and/or in the mantle material of the core-mantle particles.
19. The security and/or valuable document ac-cording to claim 17 or 18, wherein the lumines-cent substance is arranged between the particles of the photonic crystal.
20. The security and/or valuable document ac-cording to one of claims 1 to 19, wherein the photonic crystal is underlaid with the lumines-cent substance.
21. A method for producing a security and/or valuable document or a security element accord-ing to one of claims 1 to 20, wherein the sub-strate is provided on a surface or partial sur-face with a coating comprising the particles of the photonic crystal to be formed, and this coating is condensed under simultaneous exposure to heat and pressure, optionally before coating with the particles of the photonic crystal, a luminescent layer comprising the luminescent substance being applied to the substrate, and/or the particles of the photonic crystal comprising the luminescent substance or being mixed therewith.
22. The method according to claim 21, wherein the exposure to heat takes place with a tempera-ture in the range from 60 to 180 °C, in particu-lar from 70 to 130 °C, and for a time from 0.5 to 7,200 s, preferably from 0.5 to 3,600 s, most preferably from 1 to 10 s.
23. The method according to claim 21 or 22, wherein the condensation is performed with a pressure from 1 to 100 bars, preferably from 1 to 20 bars.
24. The method according to one of claims 21 to 23, wherein the condensation is achieved by means of a press, in particular a lamination press.
25. The method according to one of claims 21 to 24, wherein on the coating with particles of the photonic crystal, a separation and/or protection layer is arranged.
26. The method according to one of claims 21 to 25, wherein the protection layer is welded dur-ing the exposure to heat and pressure to the substrate, if applicable to the luminescent layer, and to the layer with particles of the photonic crystal or is laminated so to form a layer system.
27. The method according to claim 26, wherein the protection layer is transparent, referred to the emission wavelength lambda.
28. A security and/or valuable document or secu-rity element obtainable with a method according to one of claims 21 to 27.
29. The security and/or valuable document ac-cording to one of claims 1 to 20 or 28 in the embodiment as an identity card, passport, access allowance card, visa, control symbol, ticket, driver license, vehicle document, banknote, cheque, postage stamp, credit card, chip card or adhesive label.
30. A method for verifying a security and/or valuable document or a security element accord-ing to one of claims 1 to 20 or 28 to 29, wherein the luminescent substance is excited to the emission of a luminescence radiation, the intensity of the luminescence radiation being observed or determined in dependence on the an-gle with respect to the surface of the security and/or valuable document, and the observed or determined angular dependency of the lumines-cence radiation being compared to a given angu-lar dependency.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE102007007029A DE102007007029A1 (en) | 2007-02-08 | 2007-02-08 | Security and / or value document with photonic crystal |
| DE102007007029.4 | 2007-02-08 | ||
| PCT/DE2008/000228 WO2008095481A2 (en) | 2007-02-08 | 2008-02-06 | Safety and/or valuable document having a photonic crystal |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2677418A1 true CA2677418A1 (en) | 2008-08-14 |
| CA2677418C CA2677418C (en) | 2016-09-20 |
Family
ID=39575538
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA2677418A Active CA2677418C (en) | 2007-02-08 | 2008-02-06 | Security and/or valuable document having a photonic crystal |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP2118855B1 (en) |
| CN (1) | CN101652800B (en) |
| AU (3) | AU2008213463A1 (en) |
| CA (1) | CA2677418C (en) |
| DE (1) | DE102007007029A1 (en) |
| WO (1) | WO2008095481A2 (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102007012042A1 (en) | 2007-03-13 | 2008-09-18 | Giesecke & Devrient Gmbh | security element |
| GB0720550D0 (en) | 2007-10-19 | 2007-11-28 | Rue De Int Ltd | Photonic crystal security device multiple optical effects |
| CA2656506A1 (en) * | 2009-02-27 | 2010-08-27 | Bank Of Canada | Security device |
| DE102011112696B4 (en) * | 2011-08-31 | 2016-02-18 | Martin-Luther-Universität Halle-Wittenberg | Solar cell with film for back contact, process for its preparation and use of a film as back contact |
| ES2632808T3 (en) * | 2014-09-04 | 2017-09-15 | Nicox Science Ireland | Carnosine compounds donors of nitric oxide |
| EP3109060B1 (en) | 2015-06-23 | 2018-08-15 | Hueck Folien Gesellschaft m.b.H. | Safety element and method for manufacturing a safety element |
| WO2020192579A1 (en) * | 2019-03-22 | 2020-10-01 | 苏州科技大学 | Anti-counterfeiting mark and anti-counterfeiting paper |
Family Cites Families (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4391928A (en) | 1981-09-04 | 1983-07-05 | Nl Industries, Inc. | Opacifying polymeric particle and uses |
| FR2554122B1 (en) | 1983-11-02 | 1987-03-20 | Rhone Poulenc Spec Chim | NOVEL COMPOSITION FOR MARKING DOCUMENTS AND METHOD FOR VERIFYING THE AUTHENTICITY OF SUCH DOCUMENTS |
| JP2790381B2 (en) | 1990-02-03 | 1998-08-27 | 三井化学株式会社 | Cored multilayer emulsion particles |
| GB2258659B (en) | 1991-08-14 | 1995-06-07 | De La Rue Thomas & Co Ltd | Luminescent materials and their use in security documents |
| DE19820302A1 (en) | 1998-05-04 | 2000-02-24 | Basf Ag | Core / shell particles, their manufacture and use |
| US6576155B1 (en) | 1998-11-10 | 2003-06-10 | Biocrystal, Ltd. | Fluorescent ink compositions comprising functionalized fluorescent nanocrystals |
| WO2003025035A2 (en) | 2001-09-14 | 2003-03-27 | Merck Patent Gmbh | Moulded bodies consisting of core-shell particles |
| EP1458836A1 (en) | 2001-12-18 | 2004-09-22 | Nanosolutions GmbH | Security printing liquid and method using nanoparticles |
| DE10227071A1 (en) * | 2002-06-17 | 2003-12-24 | Merck Patent Gmbh | Composite material containing core-shell particles |
| AT504587A1 (en) * | 2004-02-16 | 2008-06-15 | Hueck Folien Gmbh | IMPACT-SAFE SAFETY FEATURE WITH COLOR TIP EFFECT |
| WO2006045567A2 (en) | 2004-10-25 | 2006-05-04 | Merck Patent Gmbh | Use of moulding bodies made of core-shell particles |
| CN100378192C (en) * | 2005-04-29 | 2008-04-02 | 中国科学院上海硅酸盐研究所 | Luminescent material converted in nano level with yttrium oxide as matrix and preparation method |
| GB0615921D0 (en) * | 2006-08-10 | 2006-09-20 | Rue De Int Ltd | Photonic crystal security device |
-
2007
- 2007-02-08 DE DE102007007029A patent/DE102007007029A1/en not_active Withdrawn
-
2008
- 2008-02-06 WO PCT/DE2008/000228 patent/WO2008095481A2/en active Application Filing
- 2008-02-06 AU AU2008213463A patent/AU2008213463A1/en not_active Abandoned
- 2008-02-06 CA CA2677418A patent/CA2677418C/en active Active
- 2008-02-06 CN CN2008800043902A patent/CN101652800B/en active Active
- 2008-02-06 EP EP08715461.3A patent/EP2118855B1/en active Active
-
2014
- 2014-07-11 AU AU2014203815A patent/AU2014203815A1/en not_active Abandoned
-
2016
- 2016-09-09 AU AU2016225899A patent/AU2016225899B2/en not_active Ceased
Also Published As
| Publication number | Publication date |
|---|---|
| WO2008095481A3 (en) | 2008-12-11 |
| EP2118855A2 (en) | 2009-11-18 |
| CN101652800A (en) | 2010-02-17 |
| AU2016225899B2 (en) | 2018-02-01 |
| AU2016225899A1 (en) | 2016-09-29 |
| CA2677418C (en) | 2016-09-20 |
| EP2118855B1 (en) | 2020-09-23 |
| DE102007007029A1 (en) | 2008-08-14 |
| WO2008095481A2 (en) | 2008-08-14 |
| AU2008213463A1 (en) | 2008-08-14 |
| AU2014203815A1 (en) | 2014-07-31 |
| CN101652800B (en) | 2013-02-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| AU2016225899B2 (en) | Safety and/or valuable document having a photonic crystal | |
| JP6209755B2 (en) | How to print palpable security features | |
| US9724957B2 (en) | Irreversibly magnetically induced images or patterns | |
| EP3674099B1 (en) | Laminated body, identification, and identification verifying method | |
| JP5228666B2 (en) | Anti-counterfeit structure, anti-counterfeit sticker, anti-counterfeit transfer foil, anti-counterfeit ink, anti-counterfeit medium, anti-counterfeit paper, and authenticity determination method | |
| KR20090049582A (en) | Photonic crystal security device | |
| KR20090048586A (en) | Photonic crystal security device | |
| JP4712990B2 (en) | Anti-counterfeit print medium capable of authenticity determination and method for determining authenticity of print medium | |
| TW201501961A (en) | Security laminate | |
| JP2012236369A (en) | Fine particle, and ink, toner, sheet and medium containing the same for anti-counterfeiting | |
| JP2008162184A (en) | Forgery-proof printing medium and genuineness judging method of forgery-proof printing medium | |
| JP2004177636A (en) | Forgery prevention transfer foil, forgery prevention seal, forgery prevention medium, and method for manufacturing same | |
| JP4910374B2 (en) | Method for manufacturing anti-counterfeit information recording medium | |
| JP2019038255A (en) | Laminate, personal authentication medium and method for determining authenticity of personal authentication medium | |
| KR102187266B1 (en) | Manufacturing method of anti-counterfeit apparatus | |
| JP2004117636A (en) | Forgery preventing transfer foil, forgery preventing sticker, and forgery preventing medium and manufacturing method for the same | |
| JPH06297888A (en) | Forgery preventive certificate | |
| RU2725599C1 (en) | Composite material for marking a material object | |
| JP2008062596A (en) | Information recording medium |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request |