Method for marking products with optical security features having a time dimension - Patent Application 20070122997

Abstract

The present invention is based on a method for marking products for storing information in serialization and / or track and trace systems, as well as for document security, using two or more ink formulations, each of which contains one or more photoluminescent dyes that emit radiation in the range of 380-3000 nm under photon excitation and are distinguished by different fluorescence lifetimes.

Description

[Technical Field]

[0001] The present invention is based on a method of marking products for information storage, serialization and / or track and trace systems, and document security using two or more ink formulations, each containing one or more photoluminescent dyes that emit radiation in the range of 380-3000 nm under photon excitation and have different photoluminescent lifetimes. [Background technology]

[0002] Product counterfeiting causes global economic losses of hundreds of billions of US dollars. In Europe alone, product counterfeiting causes economic losses of over 80 billion euros. The range of counterfeit goods is enormous. Cosmetics, watches, tobacco, and medical products are increasingly being counterfeited. The pharmaceutical and tobacco industries, as required by EU directives (2011 / 62 / EU and 2014 / 40 EU), introduced serialization systems in 2019 to monitor their products. In this process, each product package is equipped with a special unique code, which is stored in a central database. Several problematic scenarios arise in the process. Hacking the database. It is important to note that no IT system can be completely protected from hacking by third parties. Hackers can store / add their own code to the central database or match it with the unique code of other companies. Therefore, it is no longer possible to verify which products are counterfeit and which are original. Pass the code to a third party. The unique code can be passed by personnel to a third party. The third party can then print the code onto the counterfeit product, which will then be deemed "authentic" according to the database. Transferring the code to another package: If the code is transferred from the original packaging to a duplicate package and the original packaging is discarded, the counterfeit preparation can be sold as genuine. This fraudulent activity is difficult to track, as database systems verify that the product at hand is not counterfeit. This risk scenario could be considered, for example, in the repackaging of stolen products / medicines and in the case of illegal trafficking of products or contraband over the Internet.

[0003] These three key points make it crucial to develop / design "cyber-physical systems" (CPS), i.e., systems that combine digital and physical features.

[0004] CPS is also required for applications in Industrie 4.0 and Logistics 4.0 (supply chain security). In Industrie 4.0, all work processes will be digitized and networked. Machines will take over the jobs of the future. This is only possible if a high level of security can be guaranteed. Machines must be trustworthy. This is achieved by equipping each end product (including sub-products, tools, processes, etc.) in a work process with an identification (in a track-and-trace manner). However, there are differences in the identification. There are three types of identification: Identification information (ID): e.g., QR code (registered trademark) Unique identification information: for example: a QR code with a serial number Security identification: e.g., a QR code with a second factor

[0005] With regard to product counterfeit prevention, two main competing solutions have been investigated in recent years: optical-based track-and-trace and authentication solutions, among others. Track-and-trace programs (U.S. Patent Nos. 9,027,147, 8,898,007, 2009 / 0096871, and 8,700,501) are used to ensure clear tracking and tracing of all process steps in manufacturing and supply chains. They allow for comprehensive control options for manufacturers and transparency for consumers, as they seamlessly document the location and path of products and documents. Information stores are required for this purpose. Depending on the information storage capacity, one-dimensional barcodes (bar dots), two-dimensional barcodes (QR Codes), three-dimensional barcodes (colored barcodes, see EP 2100277 B1), and four-dimensional barcodes (colored barcodes with a time component, see U.S. Patent Application Publication No. 2013 / 0161395 A1) are distinguished. In currently established 4D barcodes, the color pattern changes over time. However, this type is not printable because time-varying requires a display with a memory unit, so it is not used for product packaging. For authentication solutions, the interplay between anti-counterfeiting and design is fundamental. In some cases, highly decorative and innovative authentication solutions are used to protect consumers from tampering. These include both authentication solutions that are visible to the human eye and those that are invisible. Holograms and iridescent materials also belong to the authentication solution genre. Furthermore, there are three different types of authentication solutions: visible authentication solutions (overt, explicit), invisible authentication solutions (covert, covert), and forensic authentication solutions. Visible security labels are, for example, holograms. Invisible security labels are, for example, covert inks, and forensic security labels are marker systems that require complex detection equipment (e.g., microscopes). According to the current state of the art, this technology does not allow for information storage, which is a crucial disadvantage compared to track-and-trace solutions. US Patent No. 9,382,432 B1, WO 2013 / 188927 A1 and US Patent No. 6,692,031 B1 describe an invisible authentication solution based on a type of covert ink containing different quantum dots with different fluorescence lifetimes, which change the fluorescence spectrum of the covert ink over time and give the ink a time dimension. Currently, both techniques are rarely combined to form a CPS.German Patent Application No. 102019216003.4 describes a method for marking products in serialization and / or track-and-trace systems using ink formulations containing semiconducting inorganic nanocrystals that emit radiation in the range of 750-1800 nm under photon excitation. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] U.S. Patent No. 9,027,147 [Patent Document 2] U.S. Patent No. 8,898,007 [Patent Document 3] US Patent Application Publication No. 2009 / 0096871 [Patent Document 4] U.S. Patent No. 8,700,501 [Patent Document 5] European Patent No. 2100277B1 [Patent Document 6] US Patent Application Publication No. 2013 / 0161395A1 [Patent Document 7] U.S. Patent No. 9,382,432 B1 [Patent Document 8] International Publication No. 2013 / 188927A1 Brochure [Patent Document 9] U.S. Patent No. 6,692,031 B1 [Patent Document 10] German Patent Application Publication No. 102019216003 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention describes an innovative printable CPS model in which data is stored in the physical security features of a multidimensional code that also includes a time dimension. Therefore, this labeled product is more resistant to counterfeiting, since counterfeiters must print successive physical security features and / or marker systems on the product. The method according to the present invention provides security identification information that can find application as a CPS in Industry 4.0 and Logistics 4.0 or document security. [Means for solving the problem]

[0008] The present invention provides a method for labeling a product, comprising: providing two or more ink formulations, each containing one or more photoluminescent dyes, preferably one photoluminescent dye, that emit radiation under photon excitation in the range of 380 to 3000 nm, preferably 450 to 1800 nm, most preferably 750 to 1100 nm, and wherein said ink formulations differ by the different photoluminescent lifetimes of the photoluminescent dyes; generating a multi-dimensional code for identifying a product, at least one dimension, preferably two dimensions, being a spatial dimension and one dimension being a time dimension based on the photoluminescence lifetime of said photoluminescent dye; printing said ink formulation onto at least one area of ​​the surface of said product in the form of said multidimensional code; irradiating said product printed with said ink formulation with photons; detecting radiation emitted by the irradiated article in the range of 380 to 3000 nm, preferably 450 to 1800 nm, and most preferably 750 nm to 1100 nm, and the time course of the photoluminescence lifetime over a period of 1 nanosecond (ns) to 1 minute (min), preferably 1 nanosecond to 1 second (s), more preferably 1 nanosecond to 1 millisecond (ms), and most preferably 5 nanoseconds to 100 microseconds (μs) after the start of the irradiation; The present invention relates to a method comprising:

[0009] The present invention also relates to an optical time-dependent security feature in at least one surface region of a product in the form of a multidimensional code comprising two or more photoluminescent dyes that emit radiation in the range of 380-3000 nm under photon excitation and have different photoluminescent lifetimes.

[0010] Additionally, the present invention relates to the use of the optical time-dependent security features described herein as a cyber-physical system (CPS) for product surveillance.

[0011] Furthermore, the present invention relates to the use of the optical time-dependent security features described herein as a cyber-physical system (CPS) for document security.

[0012] Additionally, the present invention relates to serialization and / or track and trace systems that include optical time-dependent security features, including multidimensional codes printed on products, as described herein.

[0013] Furthermore, the present invention relates to the use of a multidimensional code printed on a product as described herein as an optical time-dependent security feature in a serialization system and / or a track and trace system.

[0014] Finally, the present invention relates to the use of the multidimensional code described herein printed on a product as an optical time-dependent security feature for document security.

[0015] definition The term "product" as used in the present invention includes the product itself to the extent that it is marked, its packaging, product labeling (tags), bar code cards and labels, and any other means typically used to mark products during the manufacturing process and / or transportation. Products include manufactured goods and their intermediate stages, commercial goods, and documents. Some examples are listed below: branded products, consumer products, pharmaceutical products, health products, nutritional products, components (parts), hardware components, electronic components, computer chips, books, manuals.

[0016] The term "document" as used herein includes natural cellulosic substrates, artificial polymeric substrates, and mixtures thereof, examples of which include, but are not limited to, banknotes, identification cards, passports, birth certificates, tickets, admission tickets, and other tickets. Some other examples are listed below: checks, bonds, bank cards, credit cards, check cards (bank-issued credit cards), currency, money cards, identification items, identification items, access items, permission items, identity cards, driver's licenses, personal items, passports, documents, paper documents, security documents, stamps, personal documents, certificates, stock certificates, debt instruments, contracts, insurance policies, wills, parking tickets, transportation tickets, and event admission tickets.

[0017] The term "ink formulation" in the sense of the present invention includes any solvents and combinations thereof, as well as typical additives suitable for producing a printable liquid.

[0018] Photoluminescence refers to the emission of a photon after prior excitation by a higher-energy photon, usually in the ultraviolet but sometimes in the visible range. The excitation propels the electron to a higher energy state. When the electron returns to a lower energy state, this energy is released again in the form of a photon. In luminescent materials, two types of excitation are broadly distinguished: in fluorescence, the electron returns from a higher singlet state to a lower energy state, while in phosphorescence, the excited electron proceeds to a raised triplet state through a transition forbidden by spin selection rules, and from there, the electron returns to the lower energy state through a transition forbidden by spin selection rules.

[0019] The term photoluminescence lifetime includes fluorescence lifetime and phosphorescence lifetime. As used herein, the term "fluorescence lifetime" refers to the average time a molecule remains in an excited singlet state during fluorescence before it emits a photon and thus returns to a lower energy state. As used herein, the term "phosphorescence lifetime" refers to the average time a molecule remains in an excited triplet state during phosphorescence before emitting a photon and returning to the ground state.

[0020] The term "multidimensional code" in the sense of the present invention includes at least a spatial dimension (i.e., x-direction), a color dimension due to the photoluminescence of the photoluminescent dyes, and a time dimension based on measuring the photoluminescence lifetime of the photoluminescent dyes used. Other possible dimensions include another spatial dimension (i.e., y-direction), and a color dimension due to the intrinsic colors of the dyes on the substrate as a multicolor code.

[0021] The term "printing" as used herein includes the deposition of pigments (dyes) onto or into a solid substrate. Typical examples include, but are not limited to, digital printing, inkjet printing, screen printing, transfer printing, stamp printing, roll-to-roll, non-contact printing, laser printing, and other processes.

[0022] The term "irradiation" as used herein includes the excitation and photoluminescence lifetime of a photoluminescence emission signal. Various excitation sources can be used for the emission signal. Some examples include LEDs, helium / xenon lamps, and laser diodes. For photoluminescence lifetimes, the pulse of excitation is typically shorter in time than the photoluminescence lifetime of the pigment. Laser diodes are readily employed for this purpose.

[0023] The term "detection" in the sense of the present invention includes, on the one hand, the detection of the luminescence signal of the photoluminescent pigment. Detectors made of silicon and germanium are suitable for this purpose. On the other hand, the term "detection" also includes the spatial and temporal detection of the photoluminescence decay time of the respective pigment. This requires special sensors and detectors that can resolve the time sequence. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. 1 shows an overview of a possible embodiment of the method for marking a product according to the invention. [Figure 2] Figure 2 shows an example of a 4-dimensional code with two spatial dimensions, x and y, a color dimension due to the fluorescence of the fluorophores represented by different colors, and a time dimension due to the different fluorescence lifetimes of three "red" fluorophores after pulsed excitation. Decay times are shown as counts over time in nanoseconds. [Figure 3] Figure 3 shows a simulated example of a four-dimensional code with two spatial dimensions in the x and y directions, a color dimension due to the photoluminescence of the photoluminescent dyes represented by different colors, and a time dimension due to different fluorescence lifetimes as detected images at periods of 0 ns (left), 25 ns (center), and 100 ns (right) after the start of photon irradiation. DETAILED DESCRIPTION OF THE INVENTION

[0025] The present invention provides a method for labeling a product, comprising: providing two or more ink formulations, each containing one or more photoluminescent dyes, preferably one photoluminescent dye, that emit radiation under photon excitation in the range of 380 to 3000 nm, preferably 450 to 1800 nm, most preferably 750 to 1100 nm, and wherein said ink formulations differ by the different photoluminescent lifetimes of the photoluminescent dyes; generating a multi-dimensional code for identifying a product, at least one dimension, preferably two dimensions, being a spatial dimension and one dimension being a time dimension based on the photoluminescence lifetime of said photoluminescent dye; printing said ink formulation onto at least one area of ​​the surface of said product in the form of said multidimensional code; irradiating said product printed with said ink formulation with photons; detecting radiation emitted by the irradiated article in the range of 380 to 3000 nm, preferably 450 to 1800 nm, and most preferably 750 to 1100 nm, and the time course of the photoluminescence lifetime over a period of 1 nanosecond to 1 minute, preferably 1 nanosecond to 1 second, more preferably 1 nanosecond to 1 millisecond, and most preferably 5 nanoseconds to 100 microseconds after the start of the irradiation; The present invention relates to a method comprising:

[0026] Two or more ink formulations are first provided, each comprising one or more photoluminescent dyes, preferably one photoluminescent dye, that emit radiation in the range of 380 to 3000 nm under photon excitation and have a photoluminescent lifetime of 1 nanosecond to 1 minute. The number of ink formulations is generally not limited and is subject only to practical, economic, and security considerations. Generally, the greater the number of ink formulations, the greater the complexity and therefore the information content of the printed unique multidimensional code. The number of ink formulations is certainly limited by the maximum number of ink formulations that can be processed by the printer used and by price limitations. Typically, 2 to 30 ink formulations, preferably 2 to 25 ink formulations, more preferably 2 to 20 ink formulations, and most preferably 3 to 15 ink formulations are used in the method according to the present invention.

[0027] The ink formulation is preferably a commercially available ink formulation suitable for depositing pigments onto or into solid substrates. Typical examples include, but are not limited to, digital printing, inkjet printing, screen printing, transfer printing, stamp printing, roll-to-roll printing, non-contact printing, laser printing, and other processes. In this case, one or more photoluminescent dyes may be added to these commercially available ink formulations.

[0028] In another embodiment, the ink formulation does not contain any color pigments other than the photoluminescent dye. In this embodiment, the multidimensional code printed with the ink formulation is invisible to the human eye due to the concentration of the photoluminescent dye. Therefore, the multidimensional code is not immediately apparent, but can be detected and read only after irradiating a product printed with the ink formulation with photons through detection of radiation emitted by the irradiated product in the range of 380 to 3000 nm. In the following embodiment, the ink formulation does not contain any color pigments other than the photoluminescent dye. In this embodiment, the multidimensional code printed with the ink formulation is visible to the human eye due to the high concentration of the ink formulation (the inherent color of the photoluminescent dye). Therefore, the multidimensional code is immediately visible. After irradiating a product printed with the ink formulation with photons, the emitted radiation in the range of 380 to 3000 nm can be detected and read.

[0029] In a fourth embodiment, a multidimensional code is first printed on at least one surface of a product using a commercially available ink formulation. Then, in a second step, an ink formulation containing a photoluminescent dye is spot-printed onto the existing multidimensional code in the form of droplets and / or other patterns, such as areas, stripes, lines, geometric shapes such as circles, triangles, rectangles, polygons, etc., alphanumeric characters, or combinations thereof. In this embodiment, the ink formulation preferably does not contain any pigments other than the photoluminescent dye, so that the droplets and / or additional multidimensional code are invisible to the human eye.

[0030] In a fifth embodiment, a multidimensional code is first printed on at least one surface of a product using a commercially available ink formulation. Then, in a second step, an ink formulation containing a photoluminescent dye is spot-applied in the form of an additional multidimensional code. In this embodiment, the ink formulation preferably does not contain any pigments other than the photoluminescent dye, so that the droplets and / or additional multidimensional code are invisible to the human eye.

[0031] In a sixth embodiment, according to one of the above embodiments, an additional unique code is generated during the printing process, for example due to high printing frequency and deflection of ink drops.

[0032] In a seventh embodiment, a multidimensional code is printed on at least one label which is subsequently adhered to at least one surface of the product according to one of the above-mentioned embodiments.

[0033] In an eighth embodiment, a unique multidimensional code according to one of the above embodiments is printed on a product label (tag), a barcode card, and / or a barcode label.

[0034] In a ninth embodiment, a unique multidimensional code is printed on a document according to one of the above-described embodiments.

[0035] Each ink formulation contains one or more photoluminescent dyes, for example, two, three, four, five or more. Preferably, each ink formulation contains one photoluminescent dye.

[0036] The photoluminescence lifetime of the photoluminescent dyes used is typically in the range of 1 nanosecond to 1 minute, preferably in the range of 1 nanosecond to 1 second, more preferably in the range of 1 nanosecond to 1 millisecond, and most preferably in the range of 5 nanoseconds to 100 microseconds.

[0037] The photoluminescence lifetimes of the various photoluminescent dyes used in the ink formulation typically vary in the range of 1 nanosecond to 1 minute, preferably in the range of 1 nanosecond to 1 second, more preferably in the range of 1 nanosecond to 1 millisecond, and most preferably in the range of 5 nanoseconds to 100 microseconds. The photoluminescence lifetime of a photoluminescent dye can be determined, for example, by the decay diagram of the emission spectrum.

[0038] The photoluminescent dye may be selected from fluorescent dyes, phosphorescent dyes and mixtures thereof. Fluorescent dyes are dyes that emit fluorescent radiation after photon excitation, and phosphorescent dyes are dyes that emit phosphorescent radiation after photon excitation.

[0039] The choice of phosphorescent dyes is generally limited only in that they emit radiation under photon excitation in the range of 380 to 3000 nm, preferably 450 to 1800 nm, and most preferably 750 nm to 1100 nm.

[0040] The phosphorescent dyes used in this patent can exhibit both a "Stokes shift" and an "anti-Stokes shift" under photon excitation. Furthermore, the luminescent materials can exhibit both fluorescent and phosphorescent behavior. The luminescent materials used can be organic and inorganic crystals / molecules.

[0041] The fluorescent dyes are typically selected from organic and inorganic fluorescent dyes or mixtures thereof.

[0042] Organic dyes can be selected from the classes of proteins and peptides, small organic molecules, synthetic oligomers and polymers, and multi-component systems. Typical examples of polymers and peptides are green fluorescent protein (GFP), yellow fluorescent protein (YFP) or red fluorescent protein (RFP).

[0043] Non-proteinaceous organic fluorescent dyes typically belong to the following classes: xanthene derivatives, cyanine derivatives, squaraine derivatives, squarainerotaxane derivatives, naphthalene derivatives, coumarin derivatives, oxadiazole derivatives, anthracene derivatives, pyrene derivatives, oxazine derivatives, acridine derivatives, arylmethine derivatives, tetrapyrrole derivatives, and dipyrromethane derivatives. Organic fluorescent dyes are typically commercially available in all emission spectral colors from blue (from 380 nm) to red (up to 3000 nm). Suitable organic dyes with an emission spectrum color from 800 nm are described, for example, in EP 0 933 407 A, U.S. Pat. No. 5,282,894, U.S. Pat. No. 5,665,151, WO 1998 / 018871 A, WO 2003 / 038003 A, U.S. Pat. No. 10,119,071 and U.S. Pat. No. 5,542,971.

[0044] Suitable inorganic pigments are preferably semiconducting inorganic nanocrystals. The semiconducting inorganic nanocrystals are preferably selected from the group consisting of perovskites, I-VI semiconductors, II-VI semiconductors, III-V semiconductors, IV-VI semiconductors, I-III-VI semiconductors, carbon dots, and mixtures thereof.

[0045] Examples of suitable semiconductor inorganic nanocrystals include AgS, AgSe, AgTe, CdS, CdSe, CdTe, PbS, PbSe, PbTe, SnTe, ZnS, ZnSe, ZnTe, InP, InAs, CuS, InSb, GaP, GaAs, GaN, InN, InGaN, ZnSSe, ZnSeTe, ZnSTe, CdSSe, CdSeTe, HgSSe, HgSeTe, HgSTe, ZnCdS, ZnCdSe, Z Examples of such compounds include nCdTe, ZnHgS, ZnHgSe, ZnHgTe, CdHgS, CdHgSe, CdHgTe, ZnCdSSe, ZnHgSSe, ZnCdSeTe, ZnHgSeTe, CdHgSSe, CdHgSeTe, CdSeCdS, CuInS2, CuInSe2, CuInGaSe2, CuInZnS2, CuZnSnSe2, CuIn(S,Se)2, CuInZn(S,Se)2, and AgIn(S,Se)2. Other suitable examples include, but are not limited to, perovskite materials having the general formula ABX3 or A4BX6, where X may be selected from Cl, Br, I, O and / or mixtures thereof, A may be selected from Cs, CH3NH3, CH(NH2)2, Ca, Sr, Bi, La, Ba, Mg and / or mixtures thereof, and B may be selected from Pb, Sn, Sr, Ge, Mg, Ca, Bi, Ti, Mn, Fe and / or mixtures thereof. Furthermore, core / shell and / or core / multishell of semiconducting inorganic nanocrystalline structures of II-VI, III-V, IV-VI, I-VI, I-III-VI semiconductors or mixtures thereof, as well as core / shell and / or core / multishell of perovskite materials are other suitable examples.

[0046] Additionally, the crystal lattice of the semiconducting inorganic nanocrystals may include, but is not limited to, Cu + , Mg 2+ , Co 2+ , Ni 2+ , Fe 2+ , Mn 2+ and / or with one or more rare earth metals such as ytterbium, praseodymium or neodymium.

[0047] The semiconducting inorganic nanocrystals preferably have an average particle size (diameter) in at least one dimension, and preferably in all dimensions, of from 1 nm to 100 nm, more preferably from 2 nm to 50 nm, and most preferably from 3 nm to 15 nm. The average particle size can be further increased / modified by various methods, typical examples of which include, but are not limited to, silica shells, titanium oxide shells, halogen shells, and other methods for enhanced stability, masking, biocompatibility, water solubility, and / or coating.

[0048] A property of semiconducting inorganic nanocrystals that is of interest to the present invention is that their excitation and emission spectra depend, inter alia, on their particle size.

[0049] Furthermore, "anti-Stokes shift" materials can also be used in the sense of the present invention. These phosphors are usually doped with elements of scandium and yttrium and elements of the lanthanide or actinide groups. The chemical composition of these phosphors consists of a host lattice, donor ions and acceptor ions. The chemical composition influences their spectral properties.

[0050] Phosphorescent materials may also be used within the meaning of the present invention. Phosphorescent materials are typically crystals doped with dopants.

[0051] The phosphorescent dye is usually selected from doped oxides, nitrides, oxynitrides, sulfides, selenides, halides, silicates, and aluminates of calcium, strontium, barium, zinc, cadmium, manganese, silicon, and rare earth metals, and mixtures thereof. Although not exclusive, sulfides of metals and zinc from the group 2 main group elements of the periodic table and aluminates of metals from the group 2 main group elements of the periodic table are usually used. The dopant can be, for example, a metal or a metal salt. Suitable examples of phosphorescent dyes are doped sulfides and aluminates of calcium, strontium, barium, and zinc, such as bismuth-doped calcium / strontium sulfide, copper-doped zinc sulfide, and europium-doped strontium aluminate.

[0052] The photoluminescent dyes with "Stokes shift" behavior used in the method according to the invention are preferably photoluminescent substances which are brought to an electronically excited energy state by optical absorption of a higher energy photon and then reach a lower energy state again by emitting light in the form of fluorescence or phosphorescence. The photoluminescent dye with "anti-Stokes shift" behavior used in the method of the present invention is preferably a photoluminescent substance that emits a photon with higher energy by absorbing two low-energy photons. Usually, there are two processes for generating "anti-Stokes shift" behavior. On the one hand, the pigment is irradiated with a high photon flux (usually a laser) so that the two low-energy photons can emit a photon with higher energy. On the other hand, when a pigment is irradiated with a flux of photons, a metastable intermediate state is created: by absorbing a photon again, a photon of higher energy can be released.

[0053] Photoluminescent dyes with "Stokes shift" behavior are preferentially excited by visible light such as UV light, blue light or white light, and near-infrared light, which are higher in energy than the luminescent signal. Photoluminescent dyes with "anti-Stokes shift" behavior are preferentially excited by near-infrared (NIR) radiation, particularly radiation with wavelengths between 750 and 1600 nm.

[0054] Under photon excitation, the photoluminescent dye emits radiation having a wavelength in the range of 380 to 3000 nm, more preferably 450 to 1800 nm, and most preferably 750 nm to 1100 nm.

[0055] The proportion of photoluminescent dyes in the ink formulation is, independently of one another, preferably 0.01 to 70.0% by weight, more preferably 0.05 to 40.0% by weight, most preferably 0.09 to 30.0% by weight of the total weight of the ink formulation. For digital and inkjet printing, the range of 0.01 to 30.0% by weight is preferred.

[0056] The ink formulation may contain photoluminescent dyes that share at least one or more, and preferably all, of the following properties: emission wavelength, emission distribution, emission maximum. In another embodiment, the ink formulation may contain a mixture of photoluminescent dyes with different emission wavelengths, emission distributions, and emission maxima.

[0057] Additionally, the ink formulation can contain commercially available ink color pigments. Commercially available ink formulations can be used and the photoluminescent dye can be added to them.

[0058] The radiation emitted from the ink formulation can result in a particular photoluminescence spectrum that depends on the type, amount, particle size, specific color, and photoluminescence lifetime of the photoluminescent dye, among other things. In this case, the individual photoluminescence spectra can be detected with a spectrometer. The detected individual photoluminescence spectra can then be compared to reference spectra stored in a database. The individual photoluminescence spectra contain a time component resulting from the use of photoluminescent dyes with different photoluminescence lifetimes, which causes the individual photoluminescence spectra to change over time, preferably over a period of 1 nanosecond to 1 minute, preferably 1 nanosecond to 1 second, more preferably 1 nanosecond to 1 millisecond, and most preferably 5 nanoseconds to 100 microseconds, after the start of irradiation. These changes can be mapped and compared using various methods. First, measurements of each photoluminescence spectrum can be taken at a fixed time, over a period of 1 nanosecond to 1 minute, preferably 1 nanosecond to 1 second, more preferably 1 nanosecond to 1 millisecond, and most preferably 5 nanoseconds to 100 microseconds, after the start of irradiation. Each photoluminescence spectrum is then compared to the corresponding reference spectrum from the same time stored in a database. Alternatively, individual "films" of fluorescence spectra can be recorded over a period of 10 nanoseconds to 1 second, preferably 20 nanoseconds to 100 milliseconds, more preferably 50 nanoseconds to 10 milliseconds, and most preferably 75 nanoseconds to 1 millisecond after the start of irradiation, and compared to reference films stored in a database.

[0059] This individual time-dependent fluorescence spectrum can be used as an additional security feature for several different ink formulations individually assembled by the product manufacturer.

[0060] Each ink formulation preferably has an inverse Ohnesorge number of less than 14, more preferably 1-10, even more preferably 1-8, and most preferably 2-4.

[0061] In a further step, a multidimensional code for identifying the product is generated, in which at least one dimension, preferably two dimensions, is a spatial dimension and one dimension is a time dimension based on the photoluminescence lifetime of the photoluminescent dye.

[0062] Suitable dimensions for multidimensional codes are the spatial dimension, e.g., the x and / or y directions, the color dimension, e.g., the inherent color of a dye on a substrate as a multicolor code and / or the photoluminescence of a photoluminescent dye emitted in space and on a substrate, and the time dimension over the photoluminescence lifetime of a photoluminescent dye.

[0063] Multidimensional codes can be three-dimensional, four-dimensional, or five-dimensional. An example of a 3D code is as follows: Barcodes containing photoluminescent dyes, which also have different photoluminescent lifetimes (one spatial dimension, one color dimension, one time dimension). An example of a 4D code is as follows: Multicolor barcodes containing photoluminescent dyes, which also have different photoluminescent lifetimes (one spatial dimension, two color dimensions, one time dimension). QR Codes® containing photoluminescent dyes, which also have different photoluminescent lifetimes (two spatial dimensions, one color dimension, one time dimension). An example of a 5D code is as follows: A multicolor QR Code® comprising photoluminescent dyes, which also have different photoluminescence lifetimes (two spatial dimensions, two color dimensions, one time dimension).

[0064] A multidimensional code may also include one or more patterns, such as areas, stripes, lines, geometric shapes such as circles, triangles, rectangles, polygons, etc., alphanumeric characters, or combinations thereof.

[0065] The multi-dimensional code may be a unique multi-dimensional code. For this purpose, preferably at least one reference amount, preferably several reference amounts of the product can first be coded with a unique key. Possible reference variables here are, for example, reference variables relating to the type and nature of the product, such as serial number, lot number, CAS number in the case of chemical products, production location, production time, delivery location, manufacturer, supplier, customer, etc. The unique key can be an algorithm provided to or created by the manufacturer. A code unique to the product, preferably to each individual packaging unit of the product, is generated by encryption.

[0066] The ink formulation is printed onto at least one area of ​​the surface of the product in the form of a multi-dimensional code.

[0067] When generating the unique multi-dimensional code, each packaging unit of the product is preferably printed with its own unique multi-dimensional code.

[0068] In a special embodiment, an additional unique multidimensional code is generated during the printing process by the individual printing patterns, which is caused by imperfections in the individual printing patterns, for example due to high printing frequency and ink drop deflection, in which case a truly unique code is generated for each printing process, since imperfections in the individual printing patterns cannot be reproduced.

[0069] The step of "printing the ink formulation in the form of this multidimensional code onto at least one area of ​​the surface of the product" here includes both printing the ink formulation directly onto at least one area of ​​the surface of the product, as far as the specifics of the product allow, as well as printing the ink formulation in the form of this multidimensional code onto at least one label and attaching / labeling at least one printed label to the surface of the product. If the shape and / or concreteness of the product does not allow for direct labeling, the step of "printing the ink formulation in the form of this multidimensional code onto at least one area of ​​the surface of the product" may also include printing the ink formulation directly onto at least one area of ​​the surface of the product's packaging or attaching / labeling at least one printed label to the surface of the product. The multi-dimensional code may be printed on the document.

[0070] For this purpose, conventional printing methods can be applied depending on the type of ink formulation. Preferably, the ink formulation is printed onto at least one surface of the product or document using digital printing, screen printing, transfer printing, roll-to-roll printing, "non-contact" printing, or laser printing.

[0071] Depending on the type of product, the multidimensional code can be printed directly on the surface of the product or document, on the product packaging, as well as on labels, signs, barcode cards and / or barcode labels.

[0072] In addition to the multidimensional code, the ink formulation may also print other patterns and unique codes on at least one surface of the product, such as areas, stripes, lines, geometric shapes such as circles, triangles, rectangles, polygons, etc., alphanumeric characters, or combinations thereof. The printed patterns here may function as purely time-dependent authentication features or may contain information such as security and instructions for use or manufacturer information.

[0073] Preferably, the ink formulations are printed side by side to form layers of dots of different photoluminescent dye compositions that provide the time-dependent pattern of the multidimensional code. In some embodiments, the ink formulations are printed side by side, and optionally on top of each other, to form one and / or more layers of dots of different photoluminescent dye compositions that provide the time-dependent pattern of the multidimensional code.

[0074] In a further step, the product printed with the ink formulation is illuminated with photons. Photon irradiation causes the photoluminescent dyes in the ink formulation to enter an excited energy state (excitation).

[0075] Preferably, products printed with the ink formulation are illuminated with ultraviolet visible light, such as blue light or white light, or NIR light, preferably ultraviolet blue or white light. For example, a black light lamp, a halogen lamp, or an LED lamp, preferably a blue or white LED lamp, can serve as the light source. In addition, a suitable light source for illumination is an LED flash, such as the LED flash of a terminal device such as a smartphone or tablet.

[0076] After irradiation, the photoluminescent dye in the irradiated product, preferably the ink formulation, emits radiation in the range of 380 to 3000 nm, preferably 450 to 1800 nm, and most preferably 750 to 1100 nm, which is detected in a further step over a period of 1 nanosecond to 1 minute, preferably 1 nanosecond to 1 second, more preferably 1 nanosecond to 1 millisecond, and most preferably 5 nanoseconds to 100 microseconds after the start of irradiation.

[0077] Typically, the irradiation time is shorter than the photoluminescence lifetime of the photoluminescent dye.

[0078] The irradiation can be either pulsed photon irradiation or continuous photon irradiation. Pulsed photon irradiation is typically performed when using photoluminescent dyes with short photoluminescence lifetimes of up to a few milliseconds, preferably when using fluorescent dyes. Continuous photon irradiation is typically performed when using photoluminescent dyes with longer photoluminescence lifetimes starting from a few milliseconds, preferably when using phosphorescent dyes.

[0079] The emitted radiation can be detected by any detection device suitable for this purpose.

[0080] In the time dimension, the individual photoluminescence spectra of the multidimensional code are observed over a period of 1 nanosecond to 1 minute, preferably 1 nanosecond to 1 second, more preferably 1 nanosecond to 1 millisecond, and most preferably 5 nanoseconds to 100 microseconds after the start of irradiation, and changes over this period are recorded. These changes are due to the different photoluminescence lifetimes of the photoluminescent dyes used, which ensures that radiation emitted from one photoluminescent dye will decay faster than radiation from another, resulting in a change in the pattern of the multidimensional code over time. These changes can be recorded and matched point by point, for example, by recording two or more spectra of the emitted radiation at fixed times during the detection period. In addition to or instead of the spectrum, images of the emitted radiation can also be acquired at each fixed time, and the changes in these images can then be compared. Alternatively, these changes can be continuously recorded, for example by creating a movie of the emitted radiation during the detection period. Various parameters of the pattern of the multidimensional code and their changes can be recorded, for example the pattern in the x and y direction, the color, the photoluminescence, or the changes in their lifetime. These parameters may then be stored in and retrieved from at least one database. The measured parameters can then be matched against the parameters stored in the database. Therefore, the pattern of the multidimensional code can be used as an optical time-dependent authentication feature.

[0081] Therefore, the method according to the invention may comprise the following further steps: storing the multidimensional code in at least one database; retrieving said multidimensional code from said database; and - A process of verifying or authenticating the product by matching this code with the detected code may include: The method can further be used in serialization systems and / or track and trace systems.

[0082] Serialization involves mapping structured data into a sequential representation format and is primarily used in distributed software systems to transfer objects over networks.

[0083] For use in a serialization system, the following additional steps: storing the unique multidimensional code in at least one database; retrieving said unique multidimensional code from said database; and - A process to verify the product by matching this code with the detected code is preferred.

[0084] In more advanced serialization systems, one or more reference quantities of a product can be recorded and / or coded using a unique key. A unique multidimensional code is generated via a corresponding serialization and / or track-and-trace computer program and printed on the product. This code is then stored in a database, preferably a central database. This code can then be scanned and read from the database at any time. The coded reference quantity of the product can then be retrieved using the serialization and / or track-and-trace computer program.

[0085] For use in a track and trace system, it is further preferred that the ink formulation is further printed in the form of a unique code on at least one area of ​​the surface of a group of packaging containing the product, e.g. selected from a bundle, outer packaging, pallet. This allows for complete tracking of individual products throughout their manufacturing and transportation journey.

[0086] The method therefore represents a combination of track and trace technology and optical security features, thus integrating the product traceability and authentication processes.

[0087] Furthermore, the method can be used to protect documents such as banknotes, ID cards, passports, birth certificates, tickets, admission passes and other tickets, or other documents described herein.

[0088] FIG. 1 shows an overview of a possible embodiment of the method according to the invention in a track-and-trace system. In this diagram, in a first step, the product reference variables are identified, such as the place and period of manufacture, the product ingredients, dosage form, etc. These reference variables are then linked to a property matrix using the different fluorescence lifetimes of the various fluorescent dyes to create a multidimensional code unique to the product. This code can be a two-dimensional, three-dimensional, or four-dimensional code, such as a barcode, QR code, or colored barcode, with the time dimension linked to the different fluorescence lifetimes of the different fluorescent dyes, respectively. This code is printed on the surface of the product using the ink formulations disclosed herein with the fluorescent dyes used for the property matrix. Depending on the product, the code may be printed directly on the surface of the product or on the product packaging.

[0089] Information from the property matrix is ​​stored in a central database, for example via a track-and-trace computer program. The product can now be passed on to a new production stage or to sales, for example. In the new environment, products are now scanned for identification and codes are read. Codes printed using the ink formulations disclosed herein can now be used as track-and-trace identifiers. The code is transferred to a track and trace computer program, which reads the code from a database and stores a reference quantity of the marked product.

[0090] The codes and all other possible markings using the ink formulations disclosed herein can also be used as optical authentication markings (as shown in FIG. 1). For this purpose, the surface of the product is exposed to light, preferably white or blue light. This excites the photoluminescent material, preferably a fluorescent dye, in the ink formulation, as described above, and then emits photoluminescent radiation (visible and NIR radiation) in the range of 400 to 1800 nm. This radiation is only partially perceptible to the human eye (up to about 800 nm). Instead, an electronic device capable of detecting visible and NIR photoluminescent radiation is required for detection. For example, a spectrometer or NIR camera would be suitable. The excitation and detection can be controlled in such a way that after excitation and detection several measurements taken at fixed times over a period of 1 nanosecond to 1 minute, preferably 1 nanosecond to 1 second, more preferably 1 nanosecond to 1 millisecond, most preferably 5 nanoseconds to 100 microseconds after the start of irradiation, or a video of the code taken over this period, appear on the screen of the terminal device. This picture thus acts as an optical time-dependent authentication feature, allowing time-dependent authentication of the product.

[0091] Thus, when used in a serialization or track-and-trace system, the method according to the present invention extends this system with a time-dependent optical security feature that is partially invisible to the human eye (750-3000 nm). The method of the present invention enhances security through the time dimension because the individual time-dependent photoluminescence spectra are emitted in the visible and near-infrared range and can be detected using a spectrometer. Additionally, the method of the present invention increases the complexity and storage capacity of the code due to the additional available dimension of the time-dependent pattern. Therefore, the individual time-dependent photoluminescence spectra can be used as an additional authentication feature. Through this time-dependent authentication feature, security features, such as QR Codes with a time-dependent second factor, can be used as CPSs at the secure identity (supply chain security) level in Industry 4.0 and Logistics 4.0. Compared to other authentication features such as RFID chips or holograms, the method according to the invention also has clear cost advantages.

[0092] The present invention also relates to an optical time-dependent security feature in at least one area of ​​the surface of a product in the form of a multidimensional code comprising two or more fluorescent dyes that emit radiation in the range of 380-3000 nm under photon excitation and that are distinguished by different fluorescence lifetimes.

[0093] Furthermore, the present invention relates to an optical time-dependent security feature in at least one area of ​​the surface of a product in the form of a multidimensional code comprising photoluminescent dyes that emit radiation in the range of 380-3000 nm under photon excitation and have different photoluminescence lifetimes. In this regard, the optical time-dependent security feature is preferably printed onto at least one area of ​​the surface of the product using the method according to the invention.

[0094] Additionally, the present invention relates to the use of the optical time-dependent security features described herein as a cyber-physical system (CPS) for product surveillance.

[0095] Furthermore, the present invention relates to the use of the optical time-dependent security features described herein as a cyber-physical system (CPS) for document security.

[0096] The present invention further relates to a serialization system and / or a track and trace system comprising an optical time-dependent security feature comprising a multi-dimensional code printed on a product as described herein.

[0097] Additionally, the present invention relates to the use of the multidimensional codes printed on products described herein as optical time-dependent security features in serialization and / or track-and-trace systems.

[0098] Additionally, the present invention relates to the use of the multidimensional codes described herein printed on products as optical time-dependent security features for document security.

[0099] In this regard, the method according to the invention increases security through the time dimension, since the individual time-dependent photoluminescence spectra are emitted in the visible and NIR range, which can be detected using a spectrometer. In addition, the method according to the invention increases the complexity and storage capacity of the code due to the additional available dimension of the time-dependent patterns.

[0100] In this regard, the ink formulations described herein comprise photoluminescent dyes that emit radiation in the range of 380-3000 nm when excited by photons and are distinguished by different photoluminescence lifetimes, and using the ink formulations described herein, the unique multidimensional code is printed on a product or product packaging or document.

[0101] The codes, ink formulations, and photoluminescent dye features described herein are also applicable to optical time-dependent security features, serialization systems and / or track-and-trace systems, and uses according to the present invention. Likewise, the features of the serialization system and / or track and trace system described herein are applicable.

[0102] Figure 2 shows an example of a printed 4D code. The code consists of a 5x5 square of different ink formulations printed side by side. The five different shades of gray in the printed squares represent ink formulations with five different fluorescent colors. In the highlighted different squares with one fluorescent color shown in dark gray, ink formulations with different fluorescent dyes were also used, and these different fluorescent dyes have different fluorescent lifetimes. These are shown in a decay diagram as counts over time in nanoseconds. The decay spectrum on the left uses semiconductor nanoparticles of CdSeCdS with an emission maximum at 621 nm and a fluorescence lifetime of 40 nanoseconds.

[0103] The central decay spectrum used semiconductor nanoparticles of CdSeCdS with an emission maximum at 623 nm and a fluorescence lifetime of 89 nanoseconds. In the decay spectrum on the right, semiconductor nanoparticles of CdSeCdS were used, which have an emission maximum at 625 nm and a fluorescence lifetime of 157 nanoseconds.

[0104] This code therefore contains two spatial dimensions, the x and y directions, a color dimension spanning the five different fluorescent colors of the fluorescent dyes, and a time dimension spanning the different fluorescent lifetimes of the fluorescent dyes.

[0105] Figure 3 shows an example of a four-dimensional code over time. Again, the code consists of 5x5 squares printed side-by-side with different ink formulations. The five different colors of the printed squares represent ink formulations with five different fluorescent colors. The time dimension is revealed from images taken at different times after the start of irradiation. Immediately after the start of irradiation (0 nanoseconds), the colors of all 25 printed squares are visible (left). 25 nanoseconds after the start of irradiation, the different squares show different decay behaviors. Some squares emit almost unchanged fluorescence, while others show perceptible decay. Five squares have already measurably disappeared their fluorescence, symbolized by the black square (center). The different decay behaviors of the fluorescence radiation indicate different fluorescence lifetimes of the fluorophores: black squares indicate a very short fluorescence lifetime, attenuated squares indicate a moderate fluorescence lifetime, and unchanged squares indicate a longer fluorescence lifetime of the fluorophores.

[0106] 100 nanoseconds after the start of illumination, only the five squares of the fluorescent dye with the longest fluorescence lifetime fluoresce. These represent a smiley face. Thus, another simple authentication feature can be introduced via the temporal dimension of the code by placing fluorescent dyes with different fluorescence lifetimes within the code so that different images and symbols that can be used as authentication features become visible depending on their decay time.

Claims

1. 1. A method of labeling a product, comprising: providing two or more ink formulations, each of said ink formulations containing one or more photoluminescent dyes that emit radiation in the range of 380 to 3000 nm under photon excitation, said ink formulations differing by different photoluminescent lifetimes of said photoluminescent dyes, said photoluminescent lifetimes of said photoluminescent dyes being in the range of 1 nanosecond to 1 millisecond; generating a multi-dimensional code for identifying a product, wherein at least one dimension is a spatial dimension and one dimension is a time dimension based on the photoluminescence lifetime of the photoluminescent dye; printing said ink formulation onto at least one area of ​​a surface of said product in the form of said multi-dimensional code; irradiating the product printed with the ink formulation with photons; detecting radiation emitted by the irradiated product in the range of 380 to 3000 nm and the time course of this radiation over a period of 1 nanosecond to 1 millisecond; A method comprising:

2. The method of claim 1 , wherein the multi-dimensional code is a three-dimensional, four-dimensional, or five-dimensional code.

3. The method of claim 1 , wherein the multi-dimensional code includes, as an additional dimension, a color code spanning the emission spectrum of the photoluminescent dye.

4. The method of claim 1 , wherein the multi-dimensional code includes, as an additional dimension, the unique color of a pigment on the substrate as a multi-color code.

5. The method of claim 1 , wherein the multi-dimensional code is generated by printing a plurality of the ink formulations separately side by side on the surface of the product.

6. The method described in claim 5, wherein the ink formulations are further printed on the surface of the product by overlaying at least one of the ink formulations on part or all of the other of the ink formulations, thereby generating the multidimensional code.

7. The method of claim 1 , wherein the photoluminescent lifetimes of the photoluminescent dyes in the ink formulation vary in the range of 1 nanosecond to 1 millisecond.

8. The method of claim 1 , wherein the multi-dimensional code includes one or more patterns.

9. storing said multi-dimensional code in at least one database; retrieving the multidimensional code from the database; and Matching the multi-dimensional code with a detected code to verify or authenticate the product. The method of claim 1 further comprising:

10. The method of claim 1 , wherein the ink formulation is further printed in the form of the multi-dimensional code on at least one area of ​​a surface of a group of packages containing the product.

11. The method of claim 1 , wherein the ink formulation is printed in the form of the multi-dimensional code on product labels, barcode cards, and barcode labels.

12. The method of claim 1 , wherein the multi-dimensional code is a unique multi-dimensional code, and at least one reference quantity of the product is encrypted using a unique key to generate the unique multi-dimensional code.

13. The method of claim 1 , wherein the ink formulation is printed onto at least one region of the surface of the product using digital printing.

14. The method of claim 1 , wherein the product printed with the ink formulation is illuminated with ultraviolet, visible, or NIR light for excitation.

15. 10. The method of claim 1, wherein two or more images and / or spectra of the emitted radiation are measured at predetermined times during a detection period.

16. The method of claim 1 , wherein the photoluminescent dye comprises a fluorescent dye selected from organic dyes and / or inorganic dyes.

17. 10. The method of claim 1, wherein the photoluminescent dye comprises a phosphorescent dye selected from doped oxides, nitrides, oxynitrides, sulfides, selenides, halides, silicates and aluminates of calcium, strontium, barium, zinc, cadmium, manganese, silicon and rare earth metals, and mixtures thereof.

18. The method of claim 1 , wherein the photoluminescent dye comprises an anti-Stokes dye.

19. 2. The method of claim 1, wherein the proportions of the photoluminescent dyes in the ink formulations are, independently of one another, from 0.01 to 70.0 wt % of the total weight of each of the ink formulations.

20. 10. The method of claim 1, wherein the emitted radiation provides a respective time-dependent photoluminescence spectrum, and the time-dependent photoluminescence spectrum is detected using a spectrometer.

21. 1. An optical time-dependent security feature in at least one surface region of a product in the form of a multidimensional code comprising two or more photoluminescent dyes that emit radiation in the range of 380-3000 nm under photon excitation and have different photoluminescent lifetimes, 21. The multidimensional code of the optical time dependent security feature is printed in at least one area of ​​the surface of the product using a method according to any one of claims 1 to 20.

22. 22. Use of an optical time-dependent security feature according to claim 21 as a Cyber-Physical System (CPS) for product surveillance and / or document security.

23. 1. A serialization system and / or track and trace system including an optical time-dependent security feature comprising said multidimensional code, 21. A serialization system and / or a track and trace system, wherein the multidimensional code of the optical time dependent security feature is printed on a product using a method according to any one of claims 1 to 20.

24. 21. Use of the multidimensional code printed on a product using the method of any one of claims 1 to 20 in serialization and / or track and trace systems and / or as an optical time-dependent security feature for document security.

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