Method for identifying and / or authenticating a security article

Abstract

The invention relates to a method for identifying and / or authenticating a security article, the method comprising searching for and / or analysing (120), in at least one portion of the security article, one or more markers representative of the presence, content and / or a morphological characteristic of a biosourced calcium-carbonate filler and determining the identity and / or authenticity (130) of the security article depending at least on comparison of the one or more markers with one or more reference data.

Description

[0001] Description

[0002] Title: Method for identifying and / or authenticating a security item

[0003] The present invention relates to a method for identifying and / or authenticating a security item.

[0004] The present invention also relates to a security element to be integrated into a security document, preferably suitable for implementing the identification and / or authentication method and to the corresponding security document.

[0005] It also relates to a security document, preferably suitable for implementing the identification and / or authentication method, preferably comprising a print or a surface layer for receiving a print and a greasy printing ink.

[0006] Technical field

[0007] The invention relates more particularly to the field of security documents.

[0008] By "security document" we mean in particular means of payment, for example banknotes, whether made of paper, polymer or their mixtures, checks, payment cards or restaurant vouchers, identity documents, such as identity cards, visas, passports or driving licenses, lottery tickets, transport tickets or even entry tickets to cultural or sporting events, but also packaging materials for overwraps, the field of coated papers and the field of luxury packaging materials and brand protection.

[0009] In order to protect against attempts to falsify or counterfeit a secure document, it is known to add security elements to a document substrate, for example in the form of fibers, particles, patches, planchettes, films, knitted structures or security threads.

[0010] Security documents are secured in particular by the addition of added security elements. These elements can be introduced either during the production of the paper, in particular in the form of fibers, particles, films, threads or knitted structures, or after manufacture, in particular in the form of films or patches, and can include security of one or more levels allowing the identification and / or authentication of the security document. The invention therefore also relates to the security elements integrated or to be integrated into a security document.

[0011] The term "security element" refers in particular to a security thread, a security particle, a security fiber, a security planchette, a security foil, a data protection film, a security patch. Such a security element may be detachable, pre-cut or to be cut from the security document in which it is integrated. Security elements may be single-layer or multi-layer. They may comprise one or more layers of paper, polymer or their mixtures.

[0012] Security documents can also be secured by adding printing.

[0013] The invention therefore also relates to an ink.

[0014] Calcium carbonate, in various crystallographic forms, is widely used in the paper, polymer, coatings and printing ink industries, particularly in security documents, security elements and / or printing inks.

[0015] It is used in powder form as a filler, particularly to reduce the production cost of materials. It contributes to the development of opacity and whiteness, and is commonly used in various families of fine papers, creative papers, and writing printing in large proportions.

[0016] In the field of coated papers, it is customary to apply layers with a high pigment content to the surface of the papers, often exceeding 80% of the composition of the layers, and here again calcium carbonate is widely used for the development of printability, whiteness and opacity.

[0017] Calcium carbonate is also used in the manufacture of printing inks and certain plastic films.

[0018] For all these applications, calcium carbonate is obtained by mining, and this source of calcium carbonate, taken from it, is not renewable.

[0019] Documents secured by using the salifiable property of calcium carbonate introduced en masse into the substrate or into a surface layer of the substrate to form a pattern are known from international applications WO2017 / 089148 and WO2018 / 234106. Also known from patent application US 2021 / 324584 is a method for marking a substrate with a spectroscopically detectable security feature to combat counterfeiting. The method comprises the following steps: providing a substrate containing a salifiable alkali or alkaline earth compound, applying a liquid treatment composition containing an acid to create a surface-modified region, and covering this region with an opaque layer. The authenticity of the product is verified by recording a spectrum of the substrate and comparing it to a library of spectra to identify the proportion of different compounds, in particular the proportion of calcium carbonate (Example 1).Spectroscopy allows the identification of calcium carbonate in the substrate of all origins. It does not allow the different origins of calcium carbonate to be distinguished.

[0020] Furthermore, international application WO2014 / 033658 discloses a method of authentication by detecting the bio-sourced material content of a document comprising a synthetic hydrocarbon polymer derived at least partially from plant resources.

[0021] There is a need to further increase document security while being environmentally responsible.

[0022] Statement of the invention

[0023] The invention thus relates, according to a first of its aspects, to a method for identifying and / or authenticating a security article, the method comprising the search and / or analysis, in at least one part of the security article, of one or more markers representative of the presence, content and / or a morphological characteristic of a calcium carbonate charge of biosourced origin and the determination of the identity and / or authenticity of the security article as a function at least of the comparison of the marker(s) with one or more reference information.

[0024] By "calcium carbonate filler of biosourced origin", here and throughout the description below, is meant a calcium carbonate filler, in particular in the form of granules or powder, obtained from a biological source of calcium carbonate, in particular by grinding and / or micronization of the biological source of calcium carbonate. The calcium carbonate filler of biosourced origin, in the invention according to its various aspects, may comprise eggshell and / or shellfish powder, in particular may comprise at least one type of calcium carbonate of biosourced origin, or a mixture of different types of calcium carbonate of biosourced origin. Preferably in the invention according to its various aspects, the particle size D50 of the calcium carbonate filler of biosourced origin is between 1 and 100 μm, better still between 1 and 50, even better still between 1 and 10 μm.Preferably in the invention according to its various aspects, the eggshell powder is devoid of the membrane extending between the albumen and the eggshell and / or the albumen. By "type of bio-sourced calcium carbonate" here and throughout the description below, is meant a bio-sourced calcium carbonate from a source selected from each of eggshell powder or shellfish powder or eggshell powder from a particular bird or family of birds, for example from chickens, ducks, quails, pheasants, turkeys, ostriches, geese, pigeons and / or guinea fowl, or shellfish powder from a particular mollusk or family of mollusks, for example from oysters, mussels, scallops, sea almonds, periwinkles, cockles, whelks, clams, cockles, razor clams, abalone, clams, limpets, scallops, clams and / or tellin.

[0025] This process provides an eco-friendly alternative for authenticating security items. The bio-based calcium carbonate source comes from the recovery of a by-product or waste.

[0026] In addition, authentication and identification can be done by different methods by determining the presence or content of the bio-sourced calcium carbonate charge and / or by determining a morphological characteristic, which allows for several levels of protection.

[0027] A safety product containing a bio-sourced calcium carbonate filler is an eco-responsible safety alternative. Indeed, the source of bio-sourced calcium carbonate comes from the recovery of a by-product or waste, which is not the case with a quarry calcium carbonate filler.

[0028] In the invention, the fact that the marker(s) are specifically representative of a biosourced calcium carbonate load makes it possible to have an identification or quantification specifically of the calcium carbonate having such an origin whether it is alone in the substrate or mixed with calcium carbonate of mining origin. It is thus possible to specifically identify the presence of calcium carbonate of biosourced origin in a mixture of calcium carbonate of several origins. The fact of having a specific identification of the calcium carbonate of biosourced origin makes it possible to envisage new safeguards based on such sources of calcium carbonate. It is thus possible in particular to have a safeguard by the simple presence of calcium carbonate of biosourced origin as opposed to calcium carbonate of mining origin which would not be identified or identified differently by the markers of the invention, and / or by

[0029] - a particular proportion of calcium carbonate of biosourced origin alone in the substrate or mixed with calcium carbonate of mining origin, a particular proportion of biosourced in relation to the total calcium carbonate constituting identification and / or authentication information, and / or by

[0030] - an identification or quantification of one or more types of calcium carbonate of biosourced origin.

[0031] Analysis and / or research

[0032] Preferably, the research and analysis involves a research and analysis method other than spectroscopy.

[0033] They can be carried out without spectroscopy or alternatively be carried out by a research and analysis method other than spectroscopy in connection with spectroscopy, in particular to quantify a ratio of the proportion of the total calcium carbonate load in the substrate, determinable by spectroscopy for example, and the proportion of the calcium carbonate load of biosourced origin in the substrate, determinable by the aforementioned method.

[0034] Advantageously, the method comprises, prior to the search and / or analysis of the marker(s) representative of the presence and / or a morphological characteristic of the calcium carbonate charge of biosourced origin, the incineration of at least part of the security article, the search and / or analysis being carried out from the ashes resulting from the incineration. This makes it possible in particular to recover only the charges in the ashes, which facilitates the search and analysis.

[0035] Preferably, the incineration temperature is chosen to decompose the organic matter and preserve the mineral part by preserving the bio-sourced calcium carbonate from possible thermal decomposition into CaO and CO2. Preferably this temperature is less than or equal to 420°C. Above such a temperature, the calcium carbonate may decompose. Such decomposition would impair the analysis.

[0036] Alternatively, the process does not include an incineration step. In this case, the process preferably includes the search for and / or analysis of the marker(s) representative of a morphological characteristic of the bio-sourced calcium carbonate charge.

[0037] Preferably, the search and / or analysis of the marker(s) representative of a morphological characteristic of the calcium carbonate charge is carried out on a cross-section of at least a portion of the security article. This search and / or analysis of markers can be done by microscopy, in particular electronic microscopy. Indeed, it is possible from a cross-section of at least a portion of the security article, to identify the specific morphological structures of the calcium carbonate of biosourced origin (e.g. stratified structure, porous and / or permeable structure, etc.) and thus to determine the identity and / or authenticity of said security article based at least on the comparison of the marker(s) with one or more reference information.

[0038] Markers

[0039] Preferably, the marker(s) comprise a marker representative of the biosourced material content. Said marker may be the carbon 14 isotope load, this being determined according to the ASTM D6866-22 standard. Thanks to the invention, it is possible to add safety to the article without modifying the manufacturing technique of the article, the article comprising a calcium carbonate load of biosourced origin therefore loaded with carbon 14 isotope being able to be used as a replacement for the same article comprising a calcium carbonate load from fossil petroleum resources therefore devoid of carbon 14 isotope.

[0040] “Biobased content” means the content as determined according to ASTM D6866-11: Determining the Biobased Content of Solid, Liquid, and Gaseous Samples Using Radiocarbon Analysis.

[0041] Furthermore, the invention allows, thanks to the presence of one or more markers, the identification and / or authentication of a security article in an easier and reliable manner. Indeed, traditionally the marking elements used for identification and / or authentication methods are introduced in tiny quantities (generally less than 0.5%), making the identification and / or authentication of the security article sometimes imprecise and unreliable. The calcium carbonate of biosourced origin used as a marking element is introduced in much larger quantities than traditional marking elements. Preferably, a content of biosourced material greater than 1%, better still greater than or equal to 2%, even better still greater than or equal to 10%, even better still greater than or equal to 50% or greater than or equal to 90%.The process of identifying and / or authenticating the security article is thus facilitated by the presence of one or more marking elements present in large quantities, thus increasing the reliability of said process.

[0042] Calcium carbonate is a compound very widely used in the paper industry and therefore generally present initially in at least part of a security article. In the context of the invention, the addition of calcium carbonate of biosourced origin makes it possible both to replace an existing compound (i.e. compound necessary for the formulation of at least part of said security article), but also to play the role of marking element in a method of identifying and / or authenticating a security article. Thus, it is not necessary to add a specific compound (i.e. marker), present only for the identification and / or authentication of a security article.

[0043] The or at least one of the reference information items may include a content of bio-sourced material greater than 1%, better still greater than or equal to 2%, even better still greater than or equal to 10%, even better still greater than or equal to 50% or greater than or equal to 90%. Preferably, the method includes the incineration of the part of the article as described above and the or at least one of the reference information items corresponds to a content in the ashes of reference bio-sourced material, in particular of carbon isotope 14. By "in the ashes" is meant what remains after incineration.

[0044] The method may include determining the 14-isotope load of carbon in the ash after incineration as previously described in the at least a portion of the article and determining the identity or authenticity of the article based on comparing the determined 14-isotope load with a reference 14-isotope content or 14-isotope content range.

[0045] Alternatively or additionally, the or at least some of the markers are representative of one or more morphological characteristics of a bio-sourced calcium carbonate feedstock derived from the grinding and / or micronization of eggshells and / or shellfish. Alternatively or additionally, the or at least one of the markers is representative of one or more morphological characteristics of the or some of the bio-sourced calcium carbonate feedstock. The morphological characteristic(s) may be representative of a predetermined bio-sourced calcium carbonate source, in particular calcium carbonate from eggshells or shellfish. Additionally, the morphological characteristic(s) may be representative of a type of bio-sourced calcium carbonate, in particular eggshells from a type of bird or shellfish from a type of mollusk.

[0046] The morphological characteristic(s) may be one or more crystallographic, shape and / or porosity characteristics of the calcium carbonate of the calcium carbonate filler.

[0047] The marker(s) may comprise one or more markers representative of: a stratified structure of calcium carbonate, characteristic of the morphological structure of calcium carbonate from shellfish, and / or a porous and / or permeable structure, in particular comprising channels passing through the particles of the calcium carbonate filler of biosourced origin, characteristic of the morphological structure of calcium carbonate from eggshells.

[0048] In the case of one or more markers representative of a stratified structure, the marker(s) may include one or more morphological characteristics of the stratified structure, in particular the average density of strata and / or the average thickness of strata. Each type of shellfish has a stratified structure with its own characteristics. Determining the significant morphological characteristics of the types of shellfish allows discrimination of the type of shellfish from which all or part of the load originates. The marker(s) may allow distinction between oyster, mussel, scallop, sea almond, periwinkle, cockle, whelk, clam, cockle, razor clam, abalone, clam, limpet, scallop, clam or tellin shells, more particularly oyster, mussel, and mussel scallop shells.

[0049] In the case of one or more markers representative of a porous and / or permeable structure, the marker(s) may comprise one or more characteristics of the porous structure, in particular the porosity, the shape of the pores, the average size of the pores and / or the density of pores per unit area on a given plane. Each type of bird forms eggs having a shell with a porous structure having its own characteristics. The marker(s) may make it possible to discriminate between eggshell powders from different birds, in particular chickens, quails, pheasants, turkeys, ostriches, geese, pigeons or guinea fowl. The or one of the markers representative of the presence of eggshell powder may be the presence of a porous structure with an average pore diameter, measured in particular by analysis of one or more images of the security element or ash, of between 20 nm and 500 nm, better still between 40 nm and 400 nm.

[0050] The search and / or analysis of markers representative of morphological characteristics can be carried out by microscopy, in particular electronic microscopy with or without prior incineration. Unlike spectroscopy tools which only allow an elementary analysis of a sample, an analysis by microscopy makes it possible to obtain information on the morphology, particle sizes and crystallographic structure of a sample.

[0051] It is thus possible to determine the precise morphology of the calcium carbonate charge and to deduce an identity or authenticity in relation to reference information.

[0052] Preferably, the method comprises the search for and / or analysis of at least two markers, one being representative of the presence of calcium carbonate of biosourced origin, in particular being the presence and / or the content of carbon isotope 14 as described previously, and the other being representative of a morphological characteristic of the charge of calcium carbonate of biosourced origin, in particular being the presence of a stratified and / or porous structure and / or morphological characteristics of the structure.

[0053] The method may comprise the search for and / or analysis of one or more markers representative of a mixture of at least two types of morphologically different bio-sourced calcium carbonates, in particular eggshells from different birds, shells from different molluscs or a mixture of eggshells of one or more types and shells of one or more types. This makes it possible to increase protection by increasing the possible level of safety.

[0054] The step of searching and / or analyzing at least one part of the article may include determining the presence of a biosourced calcium carbonate filler and searching and / or analyzing one or more markers representative of the composition of the biosourced calcium carbonate filler, in particular the nature of the calcium carbonate filler(s) and / or its mass proportion(s), and determining the identity or authenticity of the article may include comparing the determined marker(s) with reference information and deducing an identity and / or authenticity of the article when there is a correspondence between the marker(s) and the reference information. It is thus possible to have security at several levels of security ranging from simple determination of the presence of biosourced calcium carbonate to its complex composition by one or more markers specific to the composition sought.This allows for multi-level security. For example, the first may involve determining the presence of bio-sourced calcium carbonate, the second may involve determining the nature of the general source, shells or mollusks, of the calcium carbonate load, and the third may involve determining the bird(s) or mollusc(s) from which the calcium carbonate originates and their proportion.

[0055] The method may additionally include the search for and / or analysis of the presence of and / or the mass proportion of a chemical compound present in the biosourced load, in particular magnesium, silicon, sodium, aluminum or chlorine. Eggshells may contain in particular magnesium and shells silicon, sodium, aluminum or chlorine.

[0056] The method may further comprise the investigation and / or analysis of the particle size distribution of the calcium carbonate filler representative of the method of obtaining the calcium carbonate filler, in particular by grinding and / or micronization, and the determination of an identity and / or authenticity based at least on the comparison of the particle size distribution and one or more reference information items, the reference information item(s) comprising information on the particle size distribution of the calcium carbonate filler or the method of obtaining the reference calcium carbonate filler. The reference information may comprise a particle size D50 of between 1 and 100 μm, better still between 1 and 50, even better still between 1 and 10 μm.

[0057] Reference information

[0058] The reference information may include information on the presence of calcium carbonate of bio-sourced origin, a reference content of calcium carbonate of bio-sourced origin, a reference mass proportion of calcium carbonate of bio-sourced origin or of one or each type of calcium carbonate of bio-sourced origin, a reference morphological characteristic of the calcium carbonate of bio-sourced origin or of one or more types of calcium carbonate of bio-sourced origin, a reference value or value range representative of a morphological characteristic of the calcium carbonate of bio-sourced origin or of one or more types of calcium carbonate of bio-sourced origin, information on the type(s) of calcium carbonate of bio-sourced origin present in a reference charge of calcium carbonate of bio-sourced origin,and / or the mass proportions of each type of bio-sourced calcium carbonate in a reference bio-sourced calcium carbonate feedstock.,

[0059] The method may comprise the prior determination of the reference information at least by searching for and / or analyzing the marker(s) on one or more reference articles whose identity and / or authenticity is known. The determination of the reference information may be done by acquiring image(s) of the bio-sourced calcium carbonate load of the reference article(s) and analyzing the acquired images and / or learning, in particular via a learning algorithm and / or neural network, from the markers identified or analyzed on the images of several reference articles.

[0060] The search and / or analysis of the markers in the part of the article, in particular directly in the part of the article or in the ash of the part of the article, is preferably carried out with a microscope, in particular optical or preferably electronic. The method may comprise the acquisition of one or more images of the part of the article to be analyzed and / or of the ash, in particular under an electron microscope, with a magnification allowing the visualization of the grains of the calcium carbonate charge on the image(s). The analysis of the substrate is preferably carried out without a particular electromagnetic detector, for example under white light.

[0061] The presence of one or more additional conventional security features on the item can also be checked.

[0062] Among these additional security elements, some are detectable by eye, in daylight or artificial light, without the use of any special device. These security elements include, for example, colored fibers or planchettes, fully or partially printed or metallized security threads, a secure knitted structure, a security film, a watermark, an optically variable element (known as "OVD"), in particular a hologram. These security elements are called first-level security elements.

[0063] Other types of additional security features are detectable only using a relatively simple device, such as a lamp emitting in the ultraviolet (UV) or infrared (IR) range. These security features include, for example, fibers, planchettes, strips, threads, or particles. These security features may or may not be visible to the naked eye, being, for example, luminescent under illumination from a Wood lamp emitting at a wavelength of 365 nm. These security features are called second-level security features.

[0064] Other types of additional security features require a more sophisticated detection device for their detection. These security features are, for example, capable of generating a specific signal when they are subjected, simultaneously or not, to one or more external excitation sources. Automatic signal detection allows the document to be authenticated, if necessary. These security features include, for example, tracers in the form of active materials, particles or fibers, capable of generating a specific signal when these tracers are subjected to optronic, electrical, magnetic or electromagnetic excitation. These security features are called third-level security features.

[0065] The additional security element(s) present within the paper according to the invention or the security document according to the invention may have first, second or third level security features.

[0066] The analysis of the substrate is preferably carried out by automatic analysis of image(s), for example via a computer, in particular a computer connected to the microscope used for the analysis. The analysis can be carried out using an image analysis algorithm, in particular a learning algorithm trained from images of identified and / or authentic articles. The method can conclude on the identity and / or authenticity by comparing acquired image(s) with images acquired by another test on an article or part of an identified and / or authentic reference article.

[0067] Safety article

[0068] The search and / or analysis can be carried out on the entire article or only part of the article, in particular detachable or cut-out parts.

[0069] The security item may be a security document. The part of the security item on which the search and / or analysis is performed may be a security element embedded in the security document.

[0070] Alternatively, the security item may be a security element, in particular integrated into a security document.

[0071] The method may include at least partial extraction of the security element, in particular by separation or cutting, before the search and / or analysis. In particular, the search and / or analysis may be based on a cross-section of the security element as explained above.

[0072] The bio-sourced calcium carbonate filler may be arranged in the security element in a localized manner, in particular according to a predefined pattern that is preferably detectable, in particular visible. The method may comprise extracting the part of the security element corresponding to the part of the security element that is supposed to contain the bio-sourced calcium carbonate filler and searching for and / or analyzing the marker(s) in said part.

[0073] Security element

[0074] The invention also relates, according to a second of its aspects, to a security element to be integrated into a security document, in particular suitable for implementing the method according to the first aspect of the invention, comprising a charge of calcium carbonate of biosourced origin.

[0075] Such a safety feature represents an eco-responsible safety alternative. Indeed, the source of bio-sourced calcium carbonate comes from the recovery of a by-product or waste.

[0076] The bio-based material content in the ash, measured according to ASTM D6866-11, may be greater than 1%, better greater than or equal to 2%, even better greater than or equal to 10%, even better greater than or equal to 50% or greater than 90%.

[0077] At least a portion of, better all of, the bio-sourced calcium carbonate filler may be porous and have an average pore diameter, in particular measured by analysis of one or more images of the security element or the ash, of between 20 nm and 500 nm, better between 40 nm and 400 nm. Such porosity is in particular characteristic of an eggshell powder. The calcium carbonate filler may be an eggshell powder from a family of birds or a particular bird species. An eggshell powder from a particular bird family or bird species can be easily identified by observing the microstructure of the powder, including the shape of the pores, the ultrastructure of the powder and its crystallographic properties as evidenced by the article Yves Y. Nys et al. Structure, properties and mineralization of the eggshell: role of the organic matrix in controlling its manufacture.INRA Productions Animales, Paris: INRA, 2010, 23 (2), pp.143-154. hal- 02667365.

[0078] A portion of the bio-sourced calcium carbonate filler may have a stratified morphological structure. Such a stratified structure is particularly characteristic of shellfish powder. The calcium carbonate filler may be shellfish powder from a particular mollusk with morphological characteristics specific to this type of shellfish, in particular an average density of layers or an average thickness of layers.

[0079] Preferably, the bio-sourced calcium carbonate filler is integrated into an internal layer of the security element, the security element having a protective layer on the surface.

[0080] The security element may include printing. In the case where the calcium carbonate filler is integrated into a printing layer, the printing ink, when aqueous, preferably has a non-acidic pH, in particular greater than or equal to 7.

[0081] The calcium carbonate filler may be dispersed uniformly in the substrate or arranged locally, in particular to form an at least partially opaque area, in particular in the form of a pattern, preferably detectable, in particular visible. This allows for both visual identification and identification according to the method described above, which facilitates authentication and increases security.

[0082] The bio-sourced calcium carbonate filler can be an opacifying filler for the security element.

[0083] The security element may comprise a titanium dioxide filler. Preferably, the calcium carbonate filler is configured to form, with the titanium dioxide filler, an opacifying filler for the security element, in particular in the case of a paper-type security element. Alternatively, the security element is free of titanium dioxide, the calcium carbonate filler is integrated in mass into a substrate to form an opacifying filler for the substrate.

[0084] Forming an opacifying filler with at least part of bio-sourced calcium carbonate reduces costs by limiting the use of expensive fillers such as titanium dioxide. In addition, it reduces the environmental footprint without reducing the level of opacification.

[0085] Preferably, the security element comprises a paper layer or a polymer comprising in mass the calcium carbonate filler of biosourced origin.

[0086] The bio-sourced calcium carbonate filler may be integrated en masse into a fibrous layer, in particular comprising cellulose and / or hemicellulose fibers and / or vessels extracted from hardwoods, in particular from at least one of the following species: birch, hornbeam, chestnut, oak, eucalyptus, beech, sweetgum, nyssa, poplar, American tulip tree, preferably eucalyptus. The invention, according to this second aspect, also relates to a security document comprising a security element as described above. The security document may comprise a detachable or breakable part comprising the security element.

[0087] Security document

[0088] The invention also relates, according to a third of its aspects, to a security document, in particular suitable for implementing the identification and / or authentication method as described above, comprising a multi-layer structure comprising at least one internal layer of the security document, in particular a paper-based one, comprising in mass a charge of calcium carbonate of biosourced origin and a surface protection layer.

[0089] The content of bio-sourced material in the ashes of said document, measured according to standard ASTM D6866-11, may be greater than 1%, better still greater than or equal to 2%, even better still greater than or equal to 10%, even better still greater than or equal to 50% or greater than 90%.

[0090] At least a portion of, better still all of, the bio-sourced calcium carbonate filler may be porous and have an average diameter, measured in particular by analysis of one or more images of the security element or the ash, of pores between 20 nm and 500 nm, better still between 40 nm and 400 nm. Such porosity is in particular characteristic of an eggshell powder. The calcium carbonate filler may be an eggshell powder from a family of birds or a particular bird species.

[0091] A portion of the bio-sourced calcium carbonate filler may have a layered morphological structure. Such a layered structure is particularly characteristic of shellfish powder. The calcium carbonate filler may be shellfish powder from a particular mollusk with morphological characteristics specific to that type of shellfish.

[0092] The bio-sourced calcium carbonate filler may be an opacifying filler for the inner layer, the layers superimposed on said inner layer being at least partially transparent, better still totally transparent.

[0093] The inner layer may comprise a mixture of a titanium dioxide filler and the bio-sourced calcium carbonate filler. Preferably, the calcium carbonate filler is configured to form, with the titanium dioxide filler, an opacifying filler for the security document.

[0094] Alternatively, the inner layer is free of titanium dioxide, the calcium carbonate filler is mass-integrated into the inner layer to form an opacifying filler of the substrate.

[0095] Forming an opacifying filler with bio-sourced calcium carbonate reduces costs by limiting the use of expensive fillers such as titanium dioxide. In addition, it reduces the environmental footprint without reducing the level of opacification.

[0096] Preferably, the inner layer is a paper layer or a polymer comprising in mass the calcium carbonate filler of biosourced origin.

[0097] The inner layer may comprise a synthetic hydrocarbon polymer derived at least partially from plant resources, also referred to as a bio-sourced polymer, in particular a bio-sourced latex in which the calcium carbonate filler of bio-sourced origin is integrated in mass.

[0098] The inner layer may comprise a fibrous substrate, in particular comprising cellulose and / or hemicellulose fibres and / or vessels extracted from hardwoods, in particular from at least one of the following species: birch, hornbeam, chestnut, oak, eucalyptus, beech, sweetgum, nyssa, poplar, American tulip tree, preferably eucalyptus.

[0099] The inner layer is preferably unprinted with an ink having a pH of less than 6, preferably 7.

[0100] The inner layer may comprise more than 1% by dry mass, better still more than 2% by dry mass, even better still more than 4% by dry mass, of calcium carbonate of biosourced origin relative to the total mass of the dry matter of the inner layer. The inner layer may comprise less than 50% by mass, better still less than 40% by dry mass of calcium carbonate of biosourced origin relative to the total mass of the dry matter of the inner layer.

[0101] Preferably, the security document has printing on the outer protective layer.

[0102] The invention also relates, according to a fourth of its aspects, to a security document, in particular suitable for implementing the identification and / or authentication method as described above, comprising a surface layer and a print of an ink on the surface layer, the print and / or the surface layer comprising a calcium carbonate filler of biosourced origin, the printing ink, when it is aqueous, having a pH greater than or equal to 6, better still greater than or equal to 7.

[0103] Preferably, the security document does not comprise, in contact with the surface layer, an aqueous printing ink having a pH lower than 7, the surface layer having the charge of calcium carbonate of biosourced origin.

[0104] The fact that the ink is not or only slightly acidic prevents the calcium carbonate from becoming salty, which could degrade it.

[0105] The bio-sourced calcium carbonate filler can be integrated en masse into the surface layer or into the print.

[0106] Preferably, the bio-sourced calcium carbonate filler is an eggshell powder. The presence of a bio-sourced calcium carbonate filler in the form of eggshell powder in the printing layer or in the printing makes it possible in particular to facilitate the drying of the ink by the porosity properties of this filler as described above. The bio-sourced material content in the ash, measured according to the ASTM D6866-11 standard, may be greater than 1%, better still greater than or equal to 2%, better still greater than or equal to 10%, even better still greater than or equal to 50% or greater than 90%.

[0107] At least part of, better all of, the bio-sourced calcium carbonate filler may be porous and have an average pore diameter, measured in particular by analysis of one or more images of the security element or the ash, of between 20 nm and 500 nm, better between 40 nm and 400 nm as described previously.

[0108] The bio-sourced calcium carbonate filler can be an opacifying filler for the printing layer or the printing.

[0109] The surface layer and / or the print may comprise a mixture of a titanium dioxide filler and the bio-sourced calcium carbonate filler. Preferably, the calcium carbonate filler is configured to form, with the titanium dioxide filler, an opacifying filler for the surface layer or the print.

[0110] Alternatively, the calcium carbonate filler is incorporated en masse into the surface layer and / or the print to form an opacifying filler of the substrate, said surface layer and / or the print being free of titanium dioxide.

[0111] The surface layer may comprise a synthetic hydrocarbon polymer derived at least partially from plant resources, also referred to as a bio-sourced polymer, in particular a bio-sourced latex.

[0112] The surface layer may comprise a fibrous substrate, in particular comprising cellulose and / or hemicellulose fibres and / or vessels extracted from hardwoods, in particular from at least one of the following species: birch, hornbeam, chestnut, oak, eucalyptus, beech, sweetgum, nyssa, poplar, American tulip tree, preferably eucalyptus.

[0113] The surface layer and / or the print may comprise more than 1% by dry mass, better still more than 10% by dry mass, even better still more than 20% by dry mass, even better still more than 40% by dry mass, even better still more than 60% of calcium carbonate filler of bio-sourced origin relative to the total mass of the dry matter of the surface layer and / or the print.

[0114] Ink The invention also relates, according to a fifth of its aspects, to a greasy printing ink (hereinafter “greasy ink”) comprising a charge of calcium carbonate of biosourced origin.

[0115] The greasy ink may have a dynamic viscosity of between 0.1 and 50 Pa.s, in particular between 0.2 and 40 Pa.s and preferably between 2 and 40 Pa.s, at ambient temperature and pressure. For the purposes of the invention, an ambient temperature is understood to be a temperature varying from 18 to 25 °C.

[0116] The dynamic viscosity of oily ink can be measured by conventional methods. The selection of the measuring method as well as the appropriate measuring equipment, particularly with regard to the viscosity scale of the composition in question, clearly falls within the competence of a person skilled in the art.

[0117] For example, for an ink with a dynamic viscosity clearly lower than 2 Pa.s, a Brookfield viscometer with axis no. 2 at 100 revolutions per minute (ISO 2555) is preferred as measuring equipment.

[0118] This dynamic viscosity can be adjusted with regard to the particular function attached to the ink, but also to the application method considered for treating the surface of a support with said ink.

[0119] For example, an ink according to the invention may be deposited on the surface of a support by offset printing, screen printing, intaglio printing, typography or lithography. Preferably, the ink according to the invention is deposited on the surface of a support by intaglio printing.

[0120] Thus, at room temperature and pressure, an ink according to the invention used:

[0121] • in offset printing can advantageously have a dynamic viscosity of between 4 and 50 Pa.s,

[0122] • in screen printing can advantageously present a dynamic viscosity of between 0.1 and 10 Pa.s,

[0123] • intaglio can advantageously present a dynamic viscosity of between 5 and 20 Pa.s,

[0124] • in typography can advantageously present a dynamic viscosity of between 2 and 20 Pa.s., and

[0125] • in lithography can advantageously have a dynamic viscosity of between 10 and 20 Pa.s. Preferably, the ink is an intaglio ink, in particular with oxidative drying. The ink may comprise at least one coloring pigment other than the calcium carbonate filler of biosourced origin. Preferably, the ink is a security ink which can, with the object on which it is printed, form a security article suitable for implementing the identification and / or authentication method as described above.

[0126] Preferably, the bio-sourced calcium carbonate filler is an eggshell powder. The presence of a bio-sourced calcium carbonate filler in the form of eggshell powder in the ink makes it possible in particular to facilitate the drying of the ink by the porosity properties of this filler as described above.

[0127] The bio-based material content, measured according to ASTM D6866-11, in the ash may be greater than 1%, better greater than or equal to 2%, better greater than or equal to 10%, even better greater than or equal to 50% or greater than 90%.

[0128] At least part of, better all of, the bio-sourced calcium carbonate filler may be porous and have an average pore diameter, measured in particular by analysis of one or more images of the security element or the ash, of between 20 nm and 500 nm, better between 40 nm and 400 nm as described previously.

[0129] The ink may comprise a mixture of a titanium dioxide filler and the bio-sourced calcium carbonate filler. Preferably, the calcium carbonate filler is configured to form, with the titanium dioxide filler, an opacifying filler for the ink.

[0130] Alternatively, the ink is free of titanium dioxide.

[0131] The ink may comprise more than 1% by mass, better still more than 10% by mass, even better still more than 30% by mass, of calcium carbonate of bio-sourced origin relative to the total mass of the ink.

[0132] Brief description of the drawings

[0133] The invention may be better understood by reading the detailed description which follows, non-limiting examples of its implementation, and by examining the attached drawing, in which:

[0134] [Fig 1] Figure 1 is a schematic view of an example of a security document according to the invention, [Fig 2] Figure 2 is a block diagram of steps of an example of an identification and / or authentication method,

[0135] [Fig 3] Figure 3 corresponds to photos of eggshell powder at different magnifications,

[0136] [Fig 4] Figure 4 corresponds to photos of a scallop powder at different enlargements, and

[0137] [Fig 5] Figure 5 is a photo of an enlarged mussel shell powder.

[0138] Detailed description

[0139] Figure 1 illustrates a security document 10 which comprises a substrate 11 in which a security element 12 is integrated or on which is attached.

[0140] The secure document 10 is for example a banknote and may have a rectangular shape. The substrate 11 may be fibrous. The security element 12 may be in the example considered in the form of a security thread, patch, a security fiber, a security planchette, a security foil, a data protection film, a security patch or a security print. Preferably, the security element is located on a well-defined part of the security document. It may be integrated into the substrate 11 in bulk, or in a window or be formed from a part of the security document.

[0141] The security element may itself be detachable or cuttable to be authenticated or identified. Alternatively, it may be located on a detachable or cuttable area of ​​the security document, in particular a print 15 indicating an area to be cut for identification or authentication may be present on the security document.

[0142] The security element comprises in mass, in one of its layers, in a distributed or localized manner, or on the surface, in particular in printing, a charge of calcium carbonate of biosourced origin, in particular in the form of eggshell or seashell powder.

[0143] The bio-sourced calcium carbonate filler may be derived from the grinding and / or micronization of a single type of bio-sourced calcium carbonate, in particular eggshells from a single bird species or shells from a single type of mollusk. Alternatively, the bio-sourced calcium carbonate filler may comprise a mixture of at least two different types of bio-sourced calcium carbonate. The different types of bio-sourced calcium carbonate differ in their morphological characteristics, as is clearly apparent from the examples below.

[0144] The substrate 11 of the document may be a fibrous or polymeric substrate, or a paper-polymer hybrid. For example, it may comprise a substrate made of a bio-sourced polymer material containing or not reinforcing fibers.

[0145] Alternatively, the security document does not include a specific security element but has an internal or surface printing layer containing a bio-sourced calcium carbonate filler. In the case of a surface layer, the security document is printed using a non-acidic ink, in order to prevent degradation of the calcium carbonate. The calcium carbonate filler may be integrated en masse into the corresponding layer. In these cases, identification or authentication may be carried out on the entire security document or only part of it by cutting out a part of the security document or by detaching a pre-cut part of the document.

[0146] In addition to its characteristic markers that can be determined to identify or authenticate the document or article, the bio-sourced calcium carbonate filler can be used for various characteristics. It can be used as an opacifying filler to opacify a layer of the security document or security element or to form a particular pattern. This opacification can be local or general depending on the distribution of said filler. It can be used for its porosity properties in the case of eggshell powder, which in particular facilitates the drying of the ink or improves the strength of the substrate. It is also notable that under certain conditions, it can improve the mechanical characteristics of the substrate, in particular in the case of shell powder in a proportion greater than or equal to 5% by mass.

[0147] In a variant, the invention also relates to a greasy ink, in particular an intaglio ink with oxidative drying, which can serve as a security ink, and comprising the calcium carbonate filler of biosourced origin. The ink can have a dynamic viscosity as described above and / or be deposited on the surface of a support by a printing process as described above.

[0148] The ink may include at least one coloring pigment other than the bio-sourced calcium carbonate filler. The security item may include an additional security element on the item allowing additional first, second or third level security.

[0149] The block diagram in Figure 2 shows steps of an example of an identification and / or authentication method according to the invention.

[0150] First of all, in order to proceed with the analysis of the security article, comprising the security element, during a first optional step 100, a predetermined part of a security document is extracted, in particular a security element or a cuttable or detachable part of the security document to have a security article to be analyzed. This first step is only necessary if the analysis is not carried out on the entire security document.

[0151] In a second, optional step 110, the security article is incinerated at an incineration temperature chosen to decompose the organic matter and preserve the mineral part by preserving the bio-sourced calcium carbonate from possible thermal decomposition into CaO and CO2. Preferably, this temperature is less than or equal to 420°C.

[0152] In a third step 120, one or more markers representative of the biosourced calcium carbonate load in the safety article or in its ashes are searched for or analyzed depending on whether a prior incineration step has taken place or not.

[0153] The marker(s) may be representative of: the content of biosourced material, in particular by analyzing the carbon isotope 14 load in the ashes after incineration at step 110, the carbon isotope 14 load being determined according to standard ASTM D6866-22, and / or

[0154] - one or more morphological characteristics of the bio-sourced calcium carbonate filler, in particular representative of a predetermined type or mixture of predetermined bio-sourced calcium carbonate type. The morphological characteristic(s) may be one or more crystallographic, ultrastructure, shape and / or porosity characteristics of the calcium carbonate of the bio-sourced calcium carbonate filler.

[0155] The marker(s) may comprise one or more markers representative of a stratified structure of calcium carbonate, characteristic of the morphological structure of calcium carbonate from shells, easily identifiable on microscopy images in particular, and / or representative of a porous structure, characteristic of the morphological structure of calcium carbonate from egg shells, easily identifiable on microscopy images in particular.

[0156] In the case of one or more markers representative of a stratified structure, the marker(s) may include one or more characteristics of the stratified structure, in particular the average density of strata and / or the average thickness of strata. Each type of shellfish has a stratified structure with its own characteristics. Determining the significant morphological characteristics of the types of shellfish allows discrimination of the type of shellfish from which all or part of the load originates. The marker(s) may allow distinction between oyster, mussel, scallop, sea almond, periwinkle, cockle, whelk, clam, cockle, razor clam, abalone, clam, limpet, scallop, clam or tellin shells, more particularly oyster, mussel, and mussel scallop shells.

[0157] In the case of one or more markers representative of a porous structure, the marker(s) may comprise one or more characteristics of the porous structure, in particular the porosity, the shape of the pores, the average size of the pores and / or the density of pores per unit area on a given plane. Each type of bird forms eggs having a shell presenting a porous structure having specific characteristics. The marker(s) may make it possible to discriminate between eggshell powders from different birds, in particular chickens, quails, pheasants, turkeys, ostriches, geese, pigeons or guinea fowl. The or one of the markers representative of the presence of eggshell powder may be the presence of a porous structure with an average pore diameter, measured in particular by analysis of images of the powder, between 20 nm and 500 nm, better still between 40 nm and 400 nm.

[0158] In the case of research or analysis of morphological characteristics, it can be done with or without prior incineration, in particular by visualization under a microscope, electronic or not. The analysis of morphological characteristics can be done on the basis of a cross-section of the security article. The analysis of morphological characteristics can be done by image acquisition, in particular under an electron or optical microscope, with a magnification allowing the visualization of the calcium carbonate grains and analysis of the acquired images by a computer image analysis algorithm.

[0159] Step 120 may include the search for or analysis of at least two of the aforementioned markers, in particular the content of biosourced material in the ashes and one or more morphological characteristics.

[0160] The method may then comprise a step 130 of identifying and / or authenticating the security article by comparing the marker(s) sought or analyzed to one or more reference information items. The reference information may comprise the presence of calcium carbonate of biosourced origin, a reference content of calcium carbonate of biosourced origin, a reference mass proportion of calcium carbonate of biosourced origin or of one or each type of calcium carbonate of biosourced origin, a reference morphological characteristic of the calcium carbonate of biosourced origin or of one or more types of calcium carbonate of biosourced origin, a reference value or range of values ​​representative of a morphological characteristic of the calcium carbonate of biosourced origin or of one or more types of calcium carbonate of biosourced origin,information on the type(s) of bio-sourced calcium carbonate present in a reference bio-sourced calcium carbonate feedstock, and / or the mass proportions of each type of bio-sourced calcium carbonate in a reference bio-sourced calcium carbonate feedstock. The identification and / or authentication may be automated by a computer implementing a learning algorithm trained on identified and / or authentic reference articles.,

[0161] It is thus possible to have security at several levels of security ranging from the simple determination of the presence of calcium carbonate of biosourced origin to its complex composition. This allows for security at several levels. For example, the first may correspond to the determination of the presence of biosourced calcium carbonate, the second to the determination of the nature of the general source, shells or shellfish, of the calcium carbonate load and the third to the determination of the bird(s) or mollusc(s) from which the calcium carbonate comes and their proportion.The method may further comprise the search for and / or analysis of the particle size distribution of the calcium carbonate filler representative of the method of obtaining the calcium carbonate filler, in particular by grinding and / or micronization, and the determination of an identity and / or authenticity based at least on the comparison of the particle size distribution and one or more reference information items, the reference information item(s) comprising information on the particle size distribution of the calcium carbonate filler or the method of obtaining the reference calcium carbonate filler.

[0162] Example 1 (Determination of the bio-sourced material content in several calcium carbonate powders)

[0163] The charge of the isotope 14 of carbon is analyzed according to the ASTM method

[0164] D6866-22 to deduce the bio-sourced material content in several samples of calcium carbonate powders from different origins. The composition of the samples and the results of the analysis are given in the table below.

[0165] It is clear from the table above that the bio-sourced material content according to the ASTM D6866-22 method is a marker that is well representative of the bio-sourced origin of the calcium carbonate powder. Indeed, quarry or precipitated calcium carbonate has a bio-sourced material content of 1% while the bio-sourced material content of calcium carbonate powders from biological material is greater than 95%.

[0166] Example 2 (quarry calcium carbonate)

[0167] Below is given an example of a formulation of a pigmented layer for coated paper with approximately 25 g / m 2 filed:

[0168] For 4000L of diaper:

[0169] Starch (Collofilm MSOO): 185 Kg dry Kaolin (Kaolin 7A): 1437 Kg dry

[0170] CaCCL (Hydrocarb 90 from Omya): 1751 kg dry

[0171] Dispersant (Polysel S): 2 Kg dry

[0172] Colorant (BB violet 200%): 351 of a 0.08% dispersion

[0173] Azurant (Globrite BBU liq): 11 Kg dry

[0174] Binder (Latex DOW 950): 346 Kg dry

[0175] Additive for slip, calcium stearate (Nopcote) Cl 04:21 Kg dry

[0176] The viscosity of the layer was reduced by dilution with water with a final dry extract target of 50 - 52%.

[0177] In this formulation, the charge of crushed quarry calcium carbonate represents 47% of the dry weight of the layer and 85% of the total mineral content. The layer obtained is incinerated at a temperature of approximately 400°C and the charge of the isotope 14 of carbon is analyzed according to the ASTM D6866-22 method to deduce the content of bio-sourced material in the ash. The determined content of bio-sourced material in the ash is less than 1% by mass.

[0178] Example 3 (calcium carbonate of bio-sourced origin)

[0179] The formulation is identical to that of Example 1, but the charge of crushed quarry calcium carbonate is replaced by its weight equivalent in eggshell powder obtained by micronization. The eggshell powder used has particles smaller than 30 μm. This results in a layer of lesser whiteness but containing a source of calcium carbonate which can be used as part of a range of more natural coated papers for which it is often customary to offer ranges of lesser whiteness, of the off-white type.

[0180] The layer resulting from this combination can be deposited on the surface or as an internal layer. Better printing and improved ink drying have been noted on such a layer due to the microporous structure of the eggshell powder. In addition, the coated paper can be authenticated by ash analysis. To do this, the layer is incinerated as described in Example 1 to deduce the bio-based material content in the ash. The determined bio-based material content in the ash is approximately 99% by mass. Analysis of the bio-based material content is therefore a good means of authentication / identification of eggshell powder. Furthermore, it has been determined that eggshell powder contains identifiable magnesium, which is not the case for quarry calcium carbonate.

[0181] The bio-based content of a scallop powder was also measured. The determined bio-based content in the ash is approximately 99% by mass. Analysis of the bio-based content is therefore a good means of authentication / identification of a scallop powder.

[0182] Furthermore, it has been determined that shell powder, particularly oyster powder, may contain identifiable silicon, sodium, aluminum and / or chlorine, which is not the case with quarry calcium carbonate.

[0183] Furthermore, it is known that birds form eggs with shells of different structures and that molluscs have shells of different structures. It is therefore possible, by studying the morphological characteristics of the calcium carbonate powder, to deduce the type(s) of calcium carbonate in the ashes in order to deduce a composition of the powder to be compared with reference information corresponding to an identification or authentication signature.

[0184] Example 4

[0185] A study on a form is carried out in banknote type composition with a paper weight obtained between 80 and 85 g / m 2

[0186] In this study, the fibers are refined before the introduction of mineral fillers using a conventional method. All the forms below are manufactured using the same method, only the composition of the mineral filler changes according to the table below. The eggshell powder used has particles smaller than 30 pm.

[0187] Standards applied:

[0188] - CIE Whiteness: ISO 11475:2017

[0189] - ISO whiteness: ISO 2470-1:2016

[0190] - Degree of yellow: DIN 6167

[0191] - L*, a* and b*: ISO / CIE 11664-4:2019

[0192] - Opacity: ISO 2471:2008

[0193] The F33476 form appears less white than the F33477 form and develops, at an equivalent weight percentage of calcium carbonate used, less opacity (-1.6 points). This is associated with the organic part present in the eggshell which does not contribute to the development of the opacity of the paper.

[0194] Both types of calcium carbonate develop less opacity than titanium dioxide. On the other hand, it is possible to substitute a significant portion of titanium dioxide with eggshell powder, approaching the whiteness level of reference F33475 containing only titanium dioxide with an opacity lower by only 2 points.

[0195] Example 5

[0196] In this study, the mineral filler was introduced during the refining step for the F33510 to F33512 trusses and with the fibers before the refining step for the F33513 to F33516 trusses. The eggshell powder used has particles with sizes less than 30 pm.

[0197] Advantageously, the strong mechanical constraints applied during the refining stage then make it possible to better disperse or even micronize the mineral charge a little.

[0198] Other manufacturing characteristics are identical.

[0199] It is deduced that it is possible to substitute one part of TiO2 with two parts of eggshell filler while maintaining an equivalent level of opacity.

[0200] Example 6

[0201] Figure 3 shows photographs of eggshell powder taken with a scanning electron microscope at several magnifications.

[0202] 200 pores are clearly identifiable in these photos. Quarry calcium carbonate powder does not exhibit porosity.

[0203] It is then possible to identify that the calcium carbonate powder is derived from eggshells by identifying the presence of a porous structure. The characteristics of the porous structure can also be determined, including the average pore size or the crystallographic structure of the eggshell powder particles. These characteristics can help distinguish between the different types of eggshells forming the powder.

[0204] Example 7

[0205] Figure 4 shows photos of scallop powder taken under a scanning electron microscope at several magnifications.

[0206] A layered structure is clearly identifiable in these photos. Quarry calcium carbonate powder does not exhibit such layers.

[0207] It is then possible to identify that the calcium carbonate powder is derived from shells by identifying the presence of a layered structure. It is thus also possible to discriminate eggshell powder from shell powder by observing the porous or layered structure or to identify a mixture and the proportions of the different types in the mixture.

[0208] Example 8

[0209] Figure 5 shows a photo of mussel shell powder taken under a scanning electron microscope at several magnifications.

[0210] The layered structure is different from that of scallop particles.

[0211] It is then possible to distinguish calcium carbonate powder from scallops and mussels by analyzing the layered structure. The same is true for other shellfish, which have a different layered structure.

[0212] Example 9

[0213] In this study, several trusses were produced. The trusses differ only in the composition of their powdered mineral filler. Their optical properties are determined in the table below.

[0214] Delta E is calculated for each of the powders relative to the composition having 5% dry TiO2.

[0215] This table shows that scallop shell powder is equivalent in whiteness and opacity to quarry calcium carbonate powder. Oyster shell powder has a whiteness equivalent to eggshell powder. However, oyster shells develop a higher opacifying power than quarry calcium carbonate, eggshells, and scallop shells.

[0216] Example 10

[0217] Several trusses were produced. The trusses contain between 5% and 10% by mass of scallop powder. A reference containing 5% by mass of TiO2 is also produced. The reference and the trusses are otherwise identical to each other. Their optical properties are determined.

[0218] Corrected opacity is the opacity adjusted to account for differences in weight. It is a measured opacity independent of the weight of the sheet.

[0219] This study shows that increasing the mass percentage of scallop powder has no impact on ISO whiteness and corrected opacity, which remain lower than those of reference F33536.

[0220] Furthermore, the use of scallop powder instead of TiO2 does not degrade the mechanical properties of the paper, the tear index and the number of folds before breaking being of the same order of magnitude.

[0221] The invention is not limited to the examples which have just been described. Other types of calcium carbonate of biosourced origin than those mentioned above are possible to the extent that they are identifiable and have specific properties different from quarry calcium carbonate.

[0222] Example 11

[0223] Figure 6 represents a photo of a cross-section of a security article taken with a scanning electron microscope. In particular, the cross-section in Figure 6 was carried out to detect bio-sourced calcium carbonate present in ink. Pores 300 significant for the presence of eggshell powder are clearly identifiable in this photo of the edge (i.e. cross-section) of the security article. Quarry calcium carbonate powder does not exhibit porosity.

[0224] It is then possible to identify that the calcium carbonate powder is derived from eggshells by identifying the presence of a porous structure. The characteristics of the porous structure can also be determined, including the average pore size and / or the crystallographic structure of the eggshell powder particles. These characteristics can help discriminate between the different types of eggshells forming the powder. A similar analysis is possible by identifying the presence of a significant layered structure of a shell powder. Similarly, it is possible to determine more precise morphological characteristics such as the average thickness of the layers and / or the crystallographic structure of the shell powder to determine its source among the different types of shells.Such a cross-sectional analysis can therefore make it possible to precisely determine the source(s) of calcium carbonate in the security article and to deduce, where appropriate, authentication or identification information.

Claims

Claims 1. Method for identifying and / or authenticating a security article, the method comprising the search and / or analysis (120), in at least one part of the security article, of one or more markers representative of the presence, content and / or a morphological characteristic of a calcium carbonate charge of biosourced origin and the determination of the identity and / or authenticity (130) of the security article based at least on the comparison of the marker(s) with one or more reference information.

2. The method of claim 1, wherein the research and analysis comprises a research and analysis method other than spectroscopy.

3. Method according to claim 1 or 2, comprising, prior to the search and / or analysis (120) of the marker(s) representative of the presence and / or a morphological characteristic of the calcium carbonate charge of biosourced origin, the incineration (110) of at least part of the security article, in particular at a temperature less than or equal to 420°C, the search and / or analysis being carried out using the ashes resulting from the incineration.

4. Method according to claim 1 or 2, in which the research and / or analysis of a morphological characteristic of the calcium carbonate charge is carried out on a cross-section of at least a part of the security article.

5. Method according to claim 1 to 4, in which the marker(s) comprise a marker representative of the content of biosourced material, said marker being in particular the carbon isotope 14 load, the carbon isotope 14 load being determined according to standard ASTM D6866-22.

6. Method according to claim 5, in which the or at least one of the reference information comprises a content of biosourced material greater than 1%, better still greater than or equal to 2%, better still greater than or equal to 10%, even better still greater than or equal to 50% or greater than or equal to 90%.

7. Method according to any one of the preceding claims, in which the or at least one of the markers is representative of one or more morphological characteristics of the or part of the calcium carbonate load of biosourced origin.

8. Method according to any one of the preceding claims, in which the marker(s) comprises one or more markers representative of a stratified structure of calcium carbonate, characteristic of the morphological structure of calcium carbonate from shellfish, in particular the average density of strata and / or the average thickness of strata.

9. Method according to any one of the preceding claims, in which the marker(s) comprise one or more markers representative of a porous and / or permeable structure, characteristic of the morphological structure of calcium carbonate from eggshells, in particular the porosity, the shape of the pores, the average size of the pores and / or the density of pores per unit area on a given plane.

10. Method according to any one of the preceding claims, comprising the search for and / or analysis of at least two markers, one being representative of the presence of calcium carbonate of biosourced origin, in particular being the presence and / or the content of carbon isotope 14, and the other being representative of a morphological characteristic of the charge of calcium carbonate of biosourced origin, in particular being the presence of a stratified or porous structure and / or morphological characteristics of the structure.

11. Method according to any one of the preceding claims, comprising the search for and / or analysis of one or more markers representative of a mixture of at least two types of morphologically different calcium carbonates of biosourced origin, in particular eggshells from different birds, shellfish from different molluscs or a mixture of eggshells of one or more types and shellfish of one or more types.

12. Method according to any one of the preceding claims, in which the step of searching for and / or analyzing the at least one part of the article comprises the determination of the presence of a bio-sourced calcium carbonate filler and the search for and / or analysis of a marker representative of the composition of the bio-sourced calcium carbonate filler, in particular of the nature of the type(s) of calcium carbonate fillers in the composition of the bio-sourced calcium carbonate filler and of its or their mass proportion in the composition of the bio-sourced calcium carbonate filler, and the determination of the identity or authenticity of the article comprises the comparison of the determined marker(s) with reference information and the deduction of an identity and / or authenticity of the article when there is a correspondence between the marker(s) and the reference information.

13. Method according to any one of the preceding claims, additionally comprising the search for and / or analysis of the presence and / or the mass proportion of a chemical compound present in the biosourced load, in particular magnesium, silicon, sodium, aluminum, or chlorine.

14. Method according to any one of the preceding claims, in which the security article is a security document, in particular a banknote, in particular made of paper and / or polymer, a packaging or overwrapping material, coated paper, a payment card, the part of the security article on which the search and / or analysis is carried out being in particular a security element integrated into the security document, in particular detachable, pre-cut or to be cut, or the security article is a security element, in particular integrated into a security document.

15. Security element (12) to be integrated into a security document (10), in particular suitable for implementing the method according to any one of the preceding claims, comprising at least one charge of calcium carbonate of biosourced origin.

16. Security element according to claim 15, in which the bio-sourced calcium carbonate filler comprises eggshell and / or shellfish powder, in particular at least one type of bio-sourced calcium carbonate, or a mixture of different types of bio-sourced calcium carbonate.

17. Security document (10), in particular suitable for implementing the identification and / or authentication method as described above, comprising a multi-layer structure comprising at least one internal layer of the security document comprising in mass a charge of calcium carbonate of bio-sourced origin and a surface protection layer.

18. Security document (10), in particular suitable for implementing the identification and / or authentication method as described above, comprising a surface layer and a print of an ink on the surface layer, the print and / or the surface layer comprising a charge of original calcium carbonate bio-sourced, the printing ink, when aqueous, having a pH greater than or equal to 6, better still greater than or equal to 7.

19. Security document according to claim 17 or 18, in which the layer comprising the bio-sourced calcium carbonate filler comprises a mixture of a titanium dioxide filler and the bio-sourced calcium carbonate filler, the calcium carbonate filler being configured to form, with the titanium dioxide filler, an opacifying filler for the security document.

20. Security document according to any one of claims 17 to 19, in which the calcium carbonate filler of biosourced origin is integrated in mass in a layer comprising a synthetic hydrocarbon polymer derived at least partially from plant resources, also referred to as a biosourced polymer, in particular a biosourced latex.

21. Security document according to any one of claims 17 to 20, in which the calcium carbonate filler of biosourced origin is integrated in mass in a layer comprising a fibrous substrate comprising cellulose and / or hemicellulose fibers and / or vessels extracted from hardwoods, in particular from at least one of the following species: birch, hornbeam, chestnut, oak, eucalyptus, beech, sweetgum, nyssa, poplar, American tulip tree, preferably eucalyptus.

22. Security document according to any one of claims 18 to 21, in which the layer comprising the bio-sourced calcium carbonate filler comprises more than 1% by dry mass, better still more than 2% by dry mass, even better still more than 4% by dry mass, of bio-sourced calcium carbonate relative to the total mass of the dry matter of the internal layer.

23. Oily printing ink containing a bio-sourced calcium carbonate filler.

24. Ink according to claim 23, the ink being a security ink forming, with the object on which it is printed, a security article suitable for implementing the identification and / or authentication method as described above.

Images