WO2015122895A1 - Variations activées par la température apportées à des caractéristiques d'absorption et d'émission de lumière pour des articles de sécurité - Google Patents

Variations activées par la température apportées à des caractéristiques d'absorption et d'émission de lumière pour des articles de sécurité Download PDF

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Publication number
WO2015122895A1
WO2015122895A1 PCT/US2014/016232 US2014016232W WO2015122895A1 WO 2015122895 A1 WO2015122895 A1 WO 2015122895A1 US 2014016232 W US2014016232 W US 2014016232W WO 2015122895 A1 WO2015122895 A1 WO 2015122895A1
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WO
WIPO (PCT)
Prior art keywords
security
temperature
security feature
feature
change
Prior art date
Application number
PCT/US2014/016232
Other languages
English (en)
Inventor
Nabil Lawandy
Original Assignee
Spectra Systems Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Spectra Systems Corporation filed Critical Spectra Systems Corporation
Priority to PCT/US2014/016232 priority Critical patent/WO2015122895A1/fr
Publication of WO2015122895A1 publication Critical patent/WO2015122895A1/fr

Links

Classifications

    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
    • G09F3/00—Labels, tag tickets, or similar identification or indication means; Seals; Postage or like stamps
    • G09F3/02—Forms or constructions
    • G09F3/0291—Labels or tickets undergoing a change under particular conditions, e.g. heat, radiation, passage of time
    • 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
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D11/00—Inks
    • C09D11/50—Sympathetic, colour changing or similar inks
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
    • B41M3/00—Printing processes to produce particular kinds of printed work, e.g. patterns
    • B41M3/14—Security printing
    • B41M3/144—Security printing using fluorescent, luminescent or iridescent effects
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/62—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
    • G01N21/63—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light optically excited
    • G01N21/64—Fluorescence; Phosphorescence
    • G01N2021/6417—Spectrofluorimetric devices
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/75—Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated
    • G01N21/77—Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated by observing the effect on a chemical indicator
    • G01N2021/7769—Measurement method of reaction-produced change in sensor
    • G01N2021/7786—Fluorescence

Definitions

  • the present invention relates generally to machine detectable security markings. More specifically, the present invention relates to security articles having light emission characteristics that change in response to small changes in temperature, whether heating or cooling.
  • a disadvantage to most of the traditional security features is that they are visible and known to the world. If a counterfeiter is aware there is a security thread in a bill or a watermark in a document, replication of the security feature is easier. Once a feature is made known to the public, a counterfeiter may begin to develop specific strategies and solutions to overcome the security protections provided by the specific feature. Methods of creating and perfecting forgeries and counterfeit documents have become easier and more available with the advent of highly sophisticated computer printing and processing. As far back as 1991 , the United States Treasury has continually added security safeguard features to the denominations of currency in an attempt to combat the use of counterfeit money. These safeguards have included watermarks, security threads embedded in the paper, microprinting, color-shifting ink, and the use of multi-colored bills.
  • Embodiments of the invention include thermoemissive security articles and methods and systems for authenticating security articles through the application of temperature related stimuli, either heating or cooling.
  • an illustrative security feature includes activation of a nanoscale ll-VI or lll-V semiconductor material having an optical signature that responds to small changes in temperature by the simultaneous presence of a source of electromagnetic radiation and variation in thermal environment. Thus, initiating a change in the spectral emission response of the activation of the material in relation to small changes in the temperature of the security feature.
  • the material subject to activation is preferably a thermoemissive nanostructure synthesized to exhibit a large number of surface defect states.
  • nanostructures having a large surface area to volume ratio exhibit a large numbers of defect states resulting from unbounded surface sites.
  • Carefully synthesized nanostructures are formed in accordance with the present invention to exhibit a large number of defect states within the bulk of the nanostructure.
  • the nanostructures formed have a particularly deep excitonic state for a large gap semiconductor that in turn creates a desirable material response at or near room temperature.
  • the nanostructures are preferably ll-VI semiconductors, lll-V semiconductors, transition metal and semiconductor doped glass and doped glass nano materials.
  • the nanostructures of the present invention are formed to include large numbers of surface defects that create a plurality of electron trap states below the conduction band of the composition and/or a plurality of hole states above the valance band such that excitations are induced by small changes in energy at or around kT.
  • a security article formed using the synthesized nanostructures produces measurable changes in spectral output based on small changes in temperature at or about room temperature. This allows the security article to be verified at high speeds with low power requirements for induced temperature change.
  • Security articles such as those described herein, may require more than one stimulus, e.g., application of both light and a change in temperature, to detect the authentication feature. Further, such security articles may have security features that can be used either publicly, covertly, or both, i.e., having a first response for public access and a second response for covert usage.
  • the invention relates to a security article.
  • the security article can include a host material comprising a temperature activated security feature incorporated upon or within the host material, wherein the temperature activated security feature is capable of emitting a spectral emission that changes upon exposure to a change in the temperature of the temperature activated security feature.
  • the host material may include a polymer.
  • the host material may include a responsive portion and a non-responsive portion, wherein the temperature activated security feature may be incorporated upon or within the responsive portion.
  • the host material may include a reference security feature.
  • the security feature and the reference security feature may emit different spectral emissions upon exposure to the change in temperature.
  • the security feature and the reference security feature may emit equivalent spectral emissions upon exposure to the change in temperature.
  • FIG. 1 is an illustrative graph of the spectral emission of a security article in accordance with an embodiment of the invention
  • FIG. 2 is a magnified image of a common nanopowder
  • FIG. 3 is a magnified image of a synthesized nanopowder with a large surface area to volume ratio in accordance with an embodiment of the invention
  • FIG. 4 is an illustrative graph of the spectral emission of a security article in accordance with an embodiment of the invention at various temperatures;
  • FIG. 5 depicts the change in emission of a security article relative to changes in temperature in accordance with an embodiment of the invention
  • FIG. 6 schematically depicts a system for verifying the security feature of the present invention
  • FIG. 7 is an illustrative graph depicting a change in a composite emission of a security article in accordance with an alternate embodiment of the invention.
  • FIG. 8 depicts the application of a barcode feature to a security article in accordance with an alternate embodiment of the invention.
  • FIG. 9 depicts the response of the feature of Fig. 8. DETAILED DESCRIPTION OF THE INVENTION
  • the material subject to activation is preferably a nanostructure synthesized to exhibit a large number of surface defect states.
  • nanostructures having a large surface area to volume ratio exhibit a large numbers of defect states resulting from unbounded surface sites.
  • Carefully synthesized nanostructures are formed in accordance with the present invention to produce measurable changes in spectral output based on small changes in temperature at or about room temperature. This allows the security article to be verified at high speeds with low power requirements for induced temperature change.
  • Embodiments of the invention include fluorescent or phosphorescent emissions from a security article based on small incremental changes in temperature.
  • synthesized nanostructures having various morphologies that exhibit a large surface area to volume ratio, when subjected to small temperature changes at or above room temperature, exhibit measurable changes in emissive output.
  • Materials synthesized to form nanostructures under controlled conditions may be formed into nanoplates, nanorods and other large surface area to volume nanostructures. Such structures exhibit a large number of defect states resulting from unbounded surface sites. These defect states play an important role in material response at or near room temperature (0.025eV).
  • the nanostructures of the present invention are formed to include large numbers of surface defects that create a plurality of electron trap states below the conduction band of the composition and/or a plurality of hole states above the valance band such that excitations are induced by small changes in energy at or around kT.
  • the synthesized nanopowder exhibits a strong change in emissive response related to changes in temperature with a dramatic sensitivity in the region of room temprature and in the spectral region of about 500nm-700nm.
  • Paper materials, water-based and solvent-based inks impregnated with the synthesized ZnO flakes have a large variation in emission spectrum as shown at Fig. 4 as a function of changes in temperature from 9C- 76C.
  • Fig. 4 shows the spectrally integrated value (arb units) as a fuction of temperature.
  • the data in Fig. 5 shows that the integrated light output from this material exhibits approximately a 0.5%/1 C change with temperature. This extremely high slope efficiency near room temperature implies that small changes in temperature, whether cooling or heating, will result in a measurable change in emissive output of the material.
  • exposing the security article to a change in temperature reveals a unique spectral emission by which the security article may be authenticated.
  • excitation of the security article may include visible ambient light or sunlight, or may include other light or electromagnetic sources such as ultraviolet sources or infrared sources. Changes in temperature may be accomplished through heating elements, cooling elements or the application of a modest gas stream that induces heating or cooling.
  • the security article may include one or more temperature sensitive materials, which may be disposed on or within a permeable host material, such as a polymer material.
  • the temperature sensitive material of the security article may be part of an ink, a coating, a security thread, a planchette, a particle, a hologram, or a windowed region in a document or banknote.
  • the emission characteristics of the temperature sensitive material change with exposure to incremental heating or cooling effects.
  • the light emission or color of the temperature sensitive material may change upon excitation with a stimulus from an electromagnetic source, e.g., ultraviolet, visible or infrared.
  • authenticity of a security article may be determined by measuring the intensity of the security feature's spectral emission or change thereof.
  • a schematic detector system for analyzing the security features in a security article is depicted at Fig. 6 may include an electromagnetic or light excitation source such as the 3W 385nm LED shown, a device for spectral detection of absorption, color or emission, and a temperature altering device, such as a pump, nozzle or jet from a gas source, a heater or chiller.
  • the detector system may also be capable of measuring the time response of the phase responses of spectral changes of the security article, e.g., with respect to periodic excitation by light or temperature change.
  • the spectral emissions of a security article may be used to identify and verify the authenticity of the article. A spectral emission may be illustrated by showing the intensity of the feature as a function of wavelength.
  • a spectral emission from a typical security feature yields a signature having detectable characteristics or patterns across the wavelength spectrum.
  • the security feature is enhanced such that excitation of the feature creates a distinct spectral pattern that may be analyzed to verify authenticity. If, upon scanning the spectral emission of the article containing the feature, the expected emissive signature does not match an expected signature, the article may be a forgery or may have been tampered with. If the signature matches the expected pattern or value, the document may be authentic.
  • FIG. 7 shows a spectral emission signature of a security feature in accordance with an embodiment of the invention. Specifically, FIG. 7 depicts the intensity of an emissive response from two excitation forms - one optical, one optical and thermal. A first emission 6 is the result of optical excitation of the security feature; while a second emission 8 shows a spectral signature with a measurable change in peak emission results from the excitation of the security feature with optical and thermal exposure simultaneously.
  • a printed bar code (1 D or 2D) can be embedded along with a second phosphour or upconverting system and detected by spectral filtering as authenticated via the cooling or heating effect.
  • FIG. 8 depicts a barcode that is overlayed onto a material containing the temperature change feature of the present invention. The barcode is excited using electromagnetic stimulation to produce a fluorescent or phosphorescent spectral emission. Visually the barcode appears to produce the same emission without application of thermal stimulus (left) and with the application of thermal stimulus (right). However, with the application of thermal stimulus between the 4 th and 5 th bar of the code in Fig. 8 it can be seen at Fig. 9 in the oval region 10 that the change in the underlying temperature sensitive security feature produces a measurable change in emissive output as seen in the difference between the two spectral emission output lines 12, 14.
  • a machine-detectable security feature is included in a security article such as a document, currency, or secondary packaging for items such as tobacco, luxury goods, or pharmaceuticals.
  • the security feature may be, e.g., embedded within a security thread, planchette or as part of an ink, resulting in a visible change of the excited signature of the threads when viewed using an ultraviolet source or lamp or other appropriate excitation source.
  • Application of a controlled temperature change may lead to both a color change in the security feature as well as measurable and quantifiable spectral shifts.
  • the security feature while undetectable to the naked eye under some circumstances, emits a specific and distinct color as well as a unique spectral fingerprint under optical and thermal excitation.
  • a machine readable, covert feature may be implemented without any change to the public perception of the excited emission signature, thereby making forgery or duplication of the document more difficult.
  • a security feature may include phosphorescent material having an absorptive spectral response at certain wavelengths under optical excitation. Application of a thermal excitation to the material results in the recovery of the emissive intensity of the material.
  • compositions are described as having, including, or comprising specific components, or where processes are described as having, including or comprising specific process steps, it is contemplated that compositions of the present teachings also consist essentially of, or consist of, the recited components, and that the processes of the present teachings also consist essentially of, or consist of, the recited process steps.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Theoretical Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Finance (AREA)
  • Business, Economics & Management (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Accounting & Taxation (AREA)
  • Materials Engineering (AREA)
  • Wood Science & Technology (AREA)
  • Organic Chemistry (AREA)
  • Inspection Of Paper Currency And Valuable Securities (AREA)
  • Credit Cards Or The Like (AREA)

Abstract

L'invention concerne des articles de sécurité et des procédés et des systèmes permettant d'authentifier des articles de sécurité au moyen de l'application de stimuli liés à la température. Des nanostructure synthétisées avec soin sont formées pour montrer un grand nombre d'états défectueux au sein de la masse de la nanostructure. Le grand nombre de défauts de surface crée une pluralité d'états de pièges à électrons sous la bande de conduction de la composition et/ou une pluralité d'états de trous au-dessus de la bande de valence de sorte que des excitations soient induites par des petites variations d'énergie à kT ou autour de cette valeur. De cette manière, un article de sécurité formé à l'aide de nanostructures synthétisées produit des variations mesurables du rendement spectral sur la base de petites variations de température à température ambiante ou autour de celle-ci. Cela permet de vérifier rapidement l'article de sécurité avec de faibles exigences énergétiques pour une variation de température induite.
PCT/US2014/016232 2014-02-13 2014-02-13 Variations activées par la température apportées à des caractéristiques d'absorption et d'émission de lumière pour des articles de sécurité WO2015122895A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/US2014/016232 WO2015122895A1 (fr) 2014-02-13 2014-02-13 Variations activées par la température apportées à des caractéristiques d'absorption et d'émission de lumière pour des articles de sécurité

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Application Number Priority Date Filing Date Title
PCT/US2014/016232 WO2015122895A1 (fr) 2014-02-13 2014-02-13 Variations activées par la température apportées à des caractéristiques d'absorption et d'émission de lumière pour des articles de sécurité

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3409500A1 (fr) * 2017-06-01 2018-12-05 Schreiner Group GmbH & Co. KG Dispositif, objet pourvu de caractéristique de sécurité et procédé de fabrication d'un dispositif pour une caractéristique de sécurité

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6132958A (en) * 1999-05-27 2000-10-17 The Rockefeller University Fluorescent bead for determining the temperature of a cell and methods of use thereof
US20050109984A1 (en) * 2003-11-26 2005-05-26 Radislav Potyrailo Method of authenticating polymers, authenticatable polymers, methods of making authenticatable polymers and authenticatable articles, and articles made there from
US20050218377A1 (en) * 2004-03-31 2005-10-06 Solaris Nanosciences, Inc. Anisotropic nanoparticles and anisotropic nanostructures and pixels, displays and inks using them
US20120104743A1 (en) * 2010-11-02 2012-05-03 The Standard Register Company Thermochromic ink and document printed therewith

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6132958A (en) * 1999-05-27 2000-10-17 The Rockefeller University Fluorescent bead for determining the temperature of a cell and methods of use thereof
US20050109984A1 (en) * 2003-11-26 2005-05-26 Radislav Potyrailo Method of authenticating polymers, authenticatable polymers, methods of making authenticatable polymers and authenticatable articles, and articles made there from
US20050218377A1 (en) * 2004-03-31 2005-10-06 Solaris Nanosciences, Inc. Anisotropic nanoparticles and anisotropic nanostructures and pixels, displays and inks using them
US20120104743A1 (en) * 2010-11-02 2012-05-03 The Standard Register Company Thermochromic ink and document printed therewith

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3409500A1 (fr) * 2017-06-01 2018-12-05 Schreiner Group GmbH & Co. KG Dispositif, objet pourvu de caractéristique de sécurité et procédé de fabrication d'un dispositif pour une caractéristique de sécurité
DE102017112119A1 (de) * 2017-06-01 2018-12-06 Schreiner Group Gmbh & Co. Kg Anordnung, Etikettenanordnung für ein Sicherheitsetikett, Gegenstand mit einer Etikettenanordnung und Verfahren zum Herstellen einer Etikettenanordnung für ein Sicherheitsetikett
US10940712B2 (en) 2017-06-01 2021-03-09 Schreiner Group Gmbh & Co. Kg Arrangement, article having a security feature and method for the manufacture of an arrangement for a security feature

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