Safety document containing a polymer substrate

Abstract

Safety document comprising a polymer substrate. The invention relates to a safety document (10) comprising: - a non-opaque polymeric substrate (11) comprising a polymer produced at least partially with at least one bio-based material, and - one or more opacifying coating layers (12, 13, 14) partially covering the substrate (11) and providing at least one window (20) in which the substrate (11) is free of the coating layer. Figure for the abstract: Fig. 1

Description

Title of the invention: Safety document comprising a polymer substrate

[0001] The present invention relates to security documents comprising a polymer substrate and a method of authentication or identification of security documents, in particular security documents of the invention. technical field

[0002] The term “security document” means a security or valuable document, such as a means of payment, for example a banknote, a check, a bank card or a restaurant voucher, an identity document, such as an identity card, a visa, a passport or a driver's license, a lottery ticket, a transport ticket or even an entry ticket to cultural or sporting events.

[0003] The present invention relates to polymer substrates. By "polymer substrate" or "polymeric substrate" is meant a substrate composed of a synthetic hydrocarbon polymer.

[0004] Security documents are secured, in particular, by the addition of applied security features. These features can be introduced either during paper production, notably in the form of fibers, particles or particle agglomerates, films, yarns, or knitted structures, or after manufacturing, notably in the form of films or patches, and can include one or more levels of security enabling the identification and / or authentication of the security document. The majority of security and reinforcement features that can be applied to or introduced into the substrate are made from polymers.

[0005] The use of polymers for the substrate or safety elements makes it possible in particular to improve the mechanical properties of the final material, mainly tear resistance (according to ISO 1974) and / or double-fold resistance (according to ISO 5626), as well as resistance to soiling, in particular to wet soiling.

[0006] The majority of polymers used in safety documents and their associated components are synthetic and derived from petroleum-based fossil resources (polyamide, polyethylene terephthalate, polypropylene, etc.). Such polymers have a significant environmental impact. Alternatives to such polymers have already been proposed in some cases. Previous technique

[0007] International application WO202328627 is thus known to be a security document, a security feature or a substrate comprising recycled material, and / or made from renewable, and / or biodegradable, and / or marine raw materials. The material may be translucent.

[0008] International application WO2014033658 also discloses a safety document having a fibrous substrate comprising an attached safety element or reinforcement comprising at least one hydrocarbon-based synthetic polymer derived at least partially from plant resources. The safety element may be a safety thread or a patch and is attached to or within the safety document. The reinforcement element may be a fiber attached to or embedded in the substrate or a film attached to the substrate. The substrate for the safety element or the safety film may be made at least partially from a hydrocarbon-based synthetic polymer derived at least partially from plant resources, preferably selected from polyethylene terephthalate-based polymers, and may be transparent.This document mentions that the use of one or more synthetic hydrocarbon polymers instead of conventional synthetic or artificial polymers makes it possible to secure the substrate, in particular through the use of 14C-loaded reinforcing elements, and 14C-loaded safety elements added to the substrate, in particular by determining the bio-based material content according to the American standard ASTM D6866.

[0009] There is a need to further increase the security of documents, while addressing current environmental issues, particularly in terms of biodegradability, recycling and / or waste recovery. Description of the invention

[0010] The invention addresses this need by means of a safety document comprising:

[0011] - a non-opaque polymeric substrate comprising a polymer produced at least partially with at least one bio-based material, and

[0012] - one or more opacifying coating layers partially covering the substrate and providing at least one window in which the substrate is free of a covering layer.

[0013] The eco-friendly nature of the substrate is a fundamental aspect of the invention. By using at least some renewable and bio-based raw materials, such as plant waste or used industrial cooking oils, the substrate contributes to reducing the carbon footprint and to waste recovery. This approach is part of a sustainable development strategy and meets the growing requirements for eco-design of products. Furthermore, the possibility of using biodegradable polymers offers an alternative to traditional petrochemical-based polymers, thus promoting the integration of more environmentally friendly solutions into the life cycle of security documents.

[0014] Furthermore, given their carbon-14 isotope content, bio-based materials can provide intrinsic security to the safety document, independent of additional elements. Indeed, they offer the possibility of authentication and / or identification through the detection of the presence of carbon-14 isotope content and / or by determining the percentage of bio-based material according to ASTM D6866.

[0015] ASTM D6866 is equivalent to the international standard ISO 16620 and the French standard NF 16640, both of which are derived from the American standard ASTM D6866. In the following, any identification of the presence of carbon-14 isotope charge or determination of the bio-based material content will be carried out according to one of these standards. This will not be specified further.

[0016] The presence of a window provided in the document, free from varnish or other overlay elements, allows, by taking a sample in the easily identifiable window, to have a direct and precise measurement of the composition in terms of bio-based material of the polymer substrate only, without disturbance of other layers or additional elements, thus guaranteeing a reliable evaluation of the rate of bio-based material in the substrate. Substrate

[0017] Preferably, the substrate is a polymer or a mixture of polymers. In the case where it is a mixture of polymers, each polymer may be at least partially derived from bio-based material.

[0018] Preferably, the bio-based material is a renewable and biodegradable plant material or a mixture of renewable and / or biodegradable plant materials.

[0019] The polymer or polymers derived at least partially from bio-based material may be chosen from among synthetic hydrocarbon polymers derived at least partially from plant resources.

[0020] By "synthetic hydrocarbon polymer derived at least partially from plant resources", it is necessary to understand a polymer obtained by chemical synthesis from at least one monomer of plant origin, this monomer being able to be obtained from certain parts of plants, for example by fermentation, mechanical extraction, chemical extraction, enzymatic treatment and / or catalyzed chemical reaction.

[0021] The polymer or polymers derived at least partially from bio-based material can be produced from plant waste, for example used industrial cooking vegetable oils.

[0022] The polymer(s) produced at least partially with at least one bio-based material may be chosen from polyamide (PA), polyundecanamide (PAU), polyethylene terephthalate (PET), polyethylene furanoate (PEF), the polybutylene succinate, polyhydroxy alkanoate, polypropylene (PP), in particular biaxially oriented polypropylene (BoPP), polylactic acid (PLA), cellulose diacetate (CDA), cellophane films and mixtures thereof.

[0023] Preferably, the polymer(s) may be derived, in a proportion greater than or equal to 20% by mass, better greater than or equal to 50% by mass, even better greater than or equal to 70% by mass, even better greater than or equal to 80% by mass, from bio-based material.

[0024] The substrate may be multilayered, in particular in a plurality of layers each in a polymer produced at least partially with at least one bio-based material, in particular in the same polymer.

[0025] The substrate may comprise a core and one or two treated outer layers. The outer layer(s) may be one or more layers of the same polymer as the core, having undergone a treatment, in particular a treatment facilitating the adhesion of the outer layer(s) and / or printing, for example, a corona treatment. This makes it possible, in particular, to have a substrate with predetermined surface properties depending on the intended use and the outer layer(s).

[0026] Alternatively, the substrate is monolayer.

[0027] The substrate may be free of pigment and / or filler. This allows for a substrate containing bio-based materials only in the polymer and exhibiting interesting optical properties, particularly transparency. Alternatively, the substrate is non-transparent and contains pigments or fillers in bulk.

[0028] Preferably, the substrate is transparent. By "transparent," we mean a visible light transmission greater than typically 80%, preferably greater than or equal to 90%. Such transparency can facilitate the visibility of the window by observing the security document in transmission. Indeed, the absence of any element superimposed on the window ensures the transparency of this area and allows for easy identification of the area to be sampled for authentication or identification of the security document by detecting the carbon-14 isotope content. The authentication and / or identification is therefore not contaminated by printing and varnish or any other element that could interfere with the assessment of the bio-based material content.

[0029] The substrate may be free of paper fiber, preferably free of all fiber. Cover layers

[0030] The or at least one of the covering layers is an opacifying layer, in particular a pigmented one.

[0031] The or at least one of the covering layers may be a print.

[0032] The opacifying layer and / or the printing may contain pigments of bio-based origin. This contributes to the eco-responsibility of the security document by using renewable resources and reducing dependence on petrochemical-based materials. Furthermore, like the substrate, it can also provide additional security and offer the possibility of additional authentication or identification through the detection of the bio-based material.

[0033] The opacifying layer may further comprise a binder.

[0034] The opacifying layer can cover the surface of the substrate completely outside of the or windows. Alternatively, the pigment opacifying layer partially covers the substrate. It can form a particular pattern on the substrate.

[0035] Bio-based pigments may include bio-based calcium carbonate, in particular selected from eggshell powders of various birds, including chickens, quail, pheasants, turkeys, ostriches, geese, pigeons or guinea fowl, or shells, including oyster, mussel, scallop, sea almond, periwinkle, cockle, whelk, clam, cockle, razor clam, abalone, clam, limpet, queen scallop, cockle or tellin shells, more particularly scallop, oyster, mussel, or mixtures thereof. The presence of a bio-sourced calcium carbonate filler in the form of eggshell powder in an opacifying pigment layer makes it possible in particular to facilitate drying by the porosity properties of eggshells.

[0036] All the pigments in the opacifying layer and / or the printing may be of bio-based origin.

[0037] The binder can be a UV crosslinking resin, a solvent-based or aqueous resin, latex, or a dispersion resin.

[0038] The binder may be at least partially of bio-based origin, in particular more than 30% by mass, better more than 50% by mass of bio-based origin.

[0039] The bio-based material content of the opacifying layer, determined according to the aforementioned standards, 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 or equal to 90%.

[0040] The or one of the covering layers may exhibit biocidal properties, including antibacterial, antifungal and / or antiviral properties.

[0041] One or more of the coating layers may be a varnish.

[0042] The layer(s) may form a multilayer surface structure extending to one side or both sides of the substrate outside of at least one window. The multilayer surface structure may include a pigment opacifying layer extending on part of the substrate, an impression on the pigment opacifying layer and a varnish on the surface. Window

[0043] Preferably, in the window, the substrate is present at more than 90% by mass, better at more than 95% by mass, even better at more than 98% by mass.

[0044] Preferably, in the window, the substrate is free of surface printing. Alternatively, the security document has printing partially covering the substrate in the window.

[0045] Preferably, the substrate in the window is devoid of optical structures, in particular micromirrors, microlenses, or holographic features. Alternatively, the safety document includes an optical structure, in particular micromirrors, microlenses, or holographic features, in the window.

[0046] Preferably, the security document is transparent in the window. By "transparent," it is understood that more than 90%, or better, more than 95%, of the incident visible light is transmitted through the security document into the window.

[0047] Preferably, the safety document includes at least one area within the window in which only the substrate is present. Preferably, only the substrate is present within the entire window. Security document

[0048] The security document may include one or more additional security features, in particular in the form of fibers, particles or particle agglomerates, patches, boards, films, woven or knitted structures, or security threads outside at least one window. These features may be introduced into the substrate, in particular in the form of fibers, particles or particle agglomerates, films, security threads or woven or knitted structures, or applied to the substrate or one of the covering layers, in particular in the form of films, security threads, woven or knitted structures, or patches, and may include one or more security levels enabling the identification and / or authentication of the security document.

[0049] Among these additional security features, some are detectable to the naked eye, in daylight or artificial light, without the use of any special equipment. These security features include, for example, colored fibers or strips, printed or metallized security threads that are wholly or partially metallized, a secure knitted structure, a security film, a watermark, an optically variable element (OVD), including a hologram. These are referred to as first-level security features.

[0050] Other types of additional security features are detectable only with the aid of a relatively simple device, such as an ultraviolet emitting lamp (UV) or infrared (IR). These safety features include, for example, fibers, strips, tapes, wires, or particles or particle aggregates. These safety features may or may not be visible to the naked eye, for example, being luminescent under the illumination of a Wood's lamp emitting at a wavelength of 365 nm. These safety features are referred to as second-level safety features.

[0051] 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 subjected, simultaneously or not, to one or more external sources of excitation. 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 particle agglomerates, or fibers, capable of generating a specific signal when these tracers are subjected to optronic, electrical, magnetic, or electromagnetic excitation. These security features are referred to as third-level security features.

[0052] 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 characteristics.

[0053] The or at least one of the safety features may be as described in international application WO2014033658. It may comprise at least one polymer derived from bio-based material.

[0054] The safety document may include information relating to the bio-based content of the substrate and / or the cover layer(s). This information may be useful during an identification or authentication step by providing, for example, a reference value against which the result of the analysis is compared.

[0055] The safety document may include information indicating the location of a window in which the substrate is alone. This information may be a pattern or special mark visible on the safety document, particularly at the edge of the window.

[0056] The security document may include a detachable part, particularly for analysis. This part may be part of the substrate in the window. Authentication method

[0057] The invention also meets this need by means of a method of authentication or identification of a secure document, in particular as described above comprising the detection of the presence of a polymer produced at least partially with at least one bio-based material composing the substrate by detection of the carbon isotope 14 according to one of the aforementioned standards. Identification in the window

[0058] The authentication or identification method may include the identification of a window on the security document. This identification may be done by identifying a transparent area of ​​the security document and / or a particular pattern or symbol on the security document.

[0059] The authentication or identification method may include extracting a sample from the window, in particular by cutting out a portion of the security document from the window.

[0060] The detection of the presence of a polymer produced at least partially with at least one bio-based material can be carried out on the sample of the safety document extracted from the viewing window. This detection is performed using the methods prescribed in the aforementioned standards. It may involve burning the sample, then converting the CO2 from the combustion into graphite, and finally analyzing the carbon-14 isotope content in the resulting ash. It is thus possible to obtain a sample consisting solely of the substrate and to evaluate the bio-based material content in the substrate alone, without contamination from other elements or layers of the safety document. Indeed, if such an analysis were to be performed outside the viewing window, it would not be possible to determine whether the identified bio-based material originates from the substrate or from another layer of the safety document.

[0061] The authentication method may include detecting the bio-based content according to one of the aforementioned standards and comparing it to reference information to deduce authenticity or identity information for the security document, at least based on this comparison. The invention can authenticate the document by its substrate through the precise analysis of the percentage of compounds derived from renewable plant resources, present in the substrate, that carry the 14C isotope. It is indeed possible to use different polymers, which may have different bio-based content, or a mixture of polymers in chosen proportions, to obtain a predetermined bio-based content that constitutes the reference information.The correlation between the bio-based material content and the reference information may allow for the deduction of at least partial authenticity or identification of the safety document. Identification outside the window.

[0062] The method may further include the detection of pigments of bio-based origin in the coating layer(s).

[0063] The authentication or identification method may involve extracting a sample from outside the window, in particular by cutting out a portion of the security document from outside the window, in particular in a predetermined area which may be identified by a mark or special sign visible on the security document.

[0064] The authentication method may include detecting the bio-based material content in the sample outside the window, according to the aforementioned standards, and comparing it to the content determined within the window to deduce authenticity or identity information. This may allow for determining that the cover layer(s) are at least partially made of a bio-based material. It may also allow for identifying a difference in bio-based material content corresponding to a reference value and deducing authenticity or identity information for the safety document.

[0065] The method may include the search and / or analysis, in the sample outside the window, of one or more markers representative of the presence, content and / or a morphological characteristic of a pigment of bio-based origin, in particular of a calcium carbonate filler of bio-based origin, and the determination of the identity and / or authenticity of the safety article based at least on the comparison of the marker(s) with one or more reference information.

[0066] The marker(s) may comprise one or more markers representative of one or more morphological characteristics of bio-based pigments, for example, pigments derived from the grinding and / or micronization of eggshells and / or shells and / or a type of bio-based calcium carbonate, in particular eggshells of a type of bird or shells of a type of mollusc. The search for and / or analysis of markers representative of morphological characteristics can be carried out by microscopy, in particular electron microscopy, with or without prior incineration. It is thus possible to determine the precise morphology of the calcium carbonate charge and to deduce its identity or authenticity with respect to reference information.By "type of bio-sourced calcium carbonate", here and throughout the description below, is understood a bio-sourced calcium carbonate from a source selected from eggshell powder or shell powder or eggshell powder from a particular bird or family of birds, for example from chickens, ducks, quail, pheasants, turkeys, ostriches, geese, pigeons and / or guinea fowl, or shell powder from a particular mollusc or family of molluscs, for example from oysters, mussels, scallops, clams, periwinkles, cockles, whelks, clams, cockles, razor clams, abalone, clams, limpets, queen scallops, carpet shells and / or tellins.

[0067] The marker(s) may include one or more representative markers: - a stratified structure of calcium carbonate, characteristic of the morphological structure of calcium carbonate from shells, and / or - of a porous and / or permeable structure, notably comprising channels passing through the particles of the original calcium carbonate charge bio-based, characteristic of the morphological structure of calcium carbonate derived from eggshells.

[0068] In the case of one or more markers representing 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 specific characteristics. Determining the significant morphological characteristics of shellfish types allows for the discrimination of the shellfish type from which all or part of the load originates. The marker(s) can distinguish the shells of oysters, mussels, scallops, clams, periwinkles, cockles, whelks, clams, cockles, razor clams, abalone, palourdes, limpets, queen scallops, carpet shells, or tellins, and more particularly scallops, oysters, or mussels.

[0069] In the case of one or more markers representative of a porous and / or permeable structure, the marker(s) may include one or more characteristics of the porous structure, in particular porosity, pore shape, average pore size, and / or pore density per unit area on a given plane. Each type of bird lays eggs with a shell exhibiting a porous structure with its own specific characteristics. The marker(s) may allow for the differentiation of eggshell powders from different birds, including chickens, quail, pheasants, turkeys, ostriches, geese, pigeons, or guinea fowl. The marker(s) 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 safety element or ash, between 20 nm and 500 nm, preferably between 40 nm and 400 nm.

[0070] The method may include the determination of the bio-based material content determined in the sample from the window of the safety document and of one or more markers representative of one or more morphological characteristics of the pigments of bio-based origin determined in the sample from an area outside the window of the safety document and the determination of authenticity or identity information based on the combination of these two pieces of information.

[0071] The method may include determining the bio-based content in the sample taken from the window of the safety document and detecting the bio-based content according to the aforementioned standards in the sample outside the window and / or determining one or more markers representative of one or more morphological characteristics of pigments of bio-based origin determined in the sample outside the window, comparing these determinations with corresponding reference information and determining a information of authenticity or identity depending on the combination of this information.

[0072] The presence on the article of one or more additional conventional security features as described above can also be checked.

[0073] 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 subjected, simultaneously or not, to one or more external sources of excitation. 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 particle agglomerates, or fibers, capable of generating a specific signal when these tracers are subjected to optronic, electrical, magnetic, or electromagnetic excitation. These security features are referred to as third-level security features.

[0074] 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 characteristics.

[0075] The analysis of the security document is preferably carried out by automated image analysis, for example via a computer, in particular a computer connected to the microscope used for the analysis. The analysis can be performed using an image analysis algorithm, in particular a machine learning algorithm trained on images of identified and / or authentic reference articles. The process can determine identity and / or authenticity by comparing acquired images with images acquired by another test on an identified and / or authentic reference article or part thereof. Brief description of the drawings

[0076] The invention will be better understood upon reading the detailed description that follows, the non-limiting examples of its implementation, and upon examination of the accompanying drawing, in which:

[0077] [Fig.1] schematically represents an example of a safety document,

[0078] [Fig.2] schematically represents in cross-section at the level of the window the document of safety of the [Fig.1],

[0079] [Fig.3] schematically represents in cross-section at the window level a variant of a security document, and

[0080] [Fig.4] is a block diagram representing the steps of the authentication or identification method of the security document of [Fig.1]. Detailed description

[0081] Figures 1 and 2 illustrate a safety document 10 comprising a non-opaque substrate 11 partially covered by one or more, here several, opacifying coating layers 12, 13, and 14. The opacifying coating layers 12, 13, and 14 at least partially cover the substrate and provide at least one window 20 in which the substrate is free of an opacifying coating layer. The substrate may be the only component present in the window, as illustrated. This is preferred. However, the presence of a total or partial layer with a small weight contribution is also possible. What is important is that the main contribution in the window by material is primarily that of the substrate.

[0082] The security document 10 is, for example, a banknote and may have a rectangular shape. The security document 10 has, in the cover layers 12, 13 and 14, a window 20 formed by an area devoid of the cover layers 12, 13 and 14 in which only the substrate 11 appears.

[0083] The substrate 11 is a polymer or a mixture of polymers, each produced at least partially with at least one bio-based material. However, it could be otherwise. The substrate could be a mixture of one or more polymers produced at least partially with at least one bio-based material and one or more polymers derived from petroleum resources.

[0084] Preferably, the substrate 11 is transparent and free from any pigments and paper fibers. The bio-based material may be a renewable and / or biodegradable plant material or a mixture of renewable and / or biodegradable plant materials, for example, plant waste, such as used industrial cooking oils. The polymer may be selected from polyamide (PA), polyundecanamide (PAU), polyethylene terephthalate (PET), polyethylene furanoate (PEF), polybutylene succinate, polyhydroxy alkanoate, polypropylene (PP), in particular biaxially oriented polypropylene (BoPP), polylactic acid (PLA), cellulose diacetate (CDA), cellophane films, and mixtures thereof. The substrate 11 may comprise a polymer made up of more than 20% by mass, better more than 50% by mass, even better more than 70% by mass, even better more than 80% by mass of bio-based material or be entirely made up of bio-based material.

[0085] In the example illustrated in [Fig. 2], the substrate 11 is single-layered. However, it could be multi-layered as illustrated in [Fig. 3]. In [Fig. 3], the substrate 11 comprises a core layer 1l and two skin layers 1p, each extending from one side of the core layer 1l. All three layers are made of a polymer at least partially derived from bio-based material, in particular the same polymer. The skin layers 1p may have undergone treatment, in particular treatment facilitating adhesion of the overlay layer(s) and / or printing, by Example: Corona treatment. Despite the treatments and the multilayer structure, substrate 11 preferably remains transparent.

[0086] In the illustrated example, the topcoat layers 12, 13 and 14 may include an opacifying layer 12, a primer 13 and a varnish 14. The opacifying layer 12 may be pigmented. It may include pigments and a binder.

[0087] The pigments may be of bio-based origin. They may include a charge of calcium carbonate of bio-based origin, in particular chosen from eggshell powders of various birds, in particular chickens, quails, pheasants, turkeys, ostriches, geese, pigeons or guinea fowl, or shells, in particular oyster, mussel, scallop, sea almond, periwinkle, cockle, whelk, clam, cockle, razor clam, abalone, clam, limpet, queen scallop, razor clam or tellin shells, more particularly scallop, oyster, mussel shells, or mixtures thereof. Bio-based calcium carbonate pigments can be obtained from the grinding and / or micronization of a single type of bio-based calcium carbonate, in particular from eggshells of a single bird species or shells of a single type of mollusc.Alternatively, the bio-based calcium carbonate feedstock may comprise a mixture of at least two different types of bio-based calcium carbonate. These different types of bio-based calcium carbonate are distinguished by their morphological characteristics.

[0088] The binder may be a UV crosslinking resin, a solvent-based or aqueous resin, latex, or a dispersion resin and may be at least partially of bio-based origin, in particular more than 30% by mass, preferably more than 50% by mass of bio-based origin.

[0089] The bio-based material content of the pigment opacifying layer determined according to the aforementioned standards 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%.

[0090] The print 13 can be formed from pigments of bio-based origin as described for the opacifying layer.

[0091] One or more of the cover layers 12, 13 and 14 may have antimicrobial properties, in particular comprising silver phosphate glass particles.

[0092] The safety document 10 may include information related to the bio-based content of the substrate 11 and / or the cover layers 12, 13 or 14 and / or to the morphological characteristics of the pigments of the cover layer(s) 12, 13 or 14.

[0093] The safety document 10 may include information on the location of the window 20 in which the substrate 11 is alone. This information may be a pattern or a specific visible mark on the safety document, particularly at the edge of the window. Alternatively, there is no mark indicating the location, and the window's position can be identified by any means, including by identifying the transparent area on document 10 corresponding to window 20.

[0094] The safety document may include a part forming a sample 22 that is detachable or cut out of the window 20 and / or a part forming a sample 23 that is detachable or cut out of the window 20. These detachable or cut-out parts may be used for the analysis of the bio-based material content as described below.

[0095] The security document 10 may also include an additional security element 25 of the first, second or third level.

[0096] The additional security element 25 may, in the example considered, take the form of a security wire, a security fiber, a particle or an agglomerate of particles, a security board, a security foil, a data protection film, a security patch, or a security print. Preferably, the additional security element is located on a well-defined part of the security document. It may be integrated into the substrate 11 in bulk or as a window, be affixed to the security substrate directly or indirectly, or be formed from a portion of the security document.

[0097] The steps of an example method for identifying and / or authenticating the security document in the preceding figures have been represented in the block diagram of [Fig.4].

[0098] First, in order to proceed with the analysis of the safety article, comprising the safety element, in a first step 100, a sample 22 is extracted from the window 20.

[0099] In a second step 110, the sample 22 is analyzed by a destructive method to precisely quantify the bio-based content. The measurement is carried out according to ASTM D6866: Determining the Biobased Content of Solid, Liquid, and Gaseous Samples Using Radiocarbon Analysis. This standard allows the bio-based content to be obtained from the quantification of the carbon isotope 14 (14C).

[0100] Optionally, in a step 120, a sample 23 is extracted from the window 20, and then, in a step 125, the sample 23 is analyzed. The analysis can be carried out by a destructive method to precisely quantify the bio-based content of the sample 23 and / or by searching, in particular by microscopy, for one or more morphological characteristics of pigments, in particular of a calcium carbonate charge of bio-based origin, in particular representative of a predetermined type or mixture of predetermined type of bio-based calcium carbonate.

[0101] The morphological characteristic(s) may be one or more crystallographic, ultrastructural, shape and / or porosity characteristics of the pigments. The morphological characteristic(s) may include: - 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 - a porous structure, characteristic of the morphological structure of calcium carbonate from eggshells, easily identifiable on microscopy images in particular.

[0102] In the case of a stratified structure, the morphological characteristic(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 specific characteristics. Determining the significant morphological characteristics of shellfish types allows for the discrimination of the shellfish type from which all or part of the load originates. The morphological characteristic(s) can make it possible to distinguish the shells of oysters, mussels, scallops, clams, periwinkles, cockles, whelks, clams, cockles, razor clams, abalone, palourdes, limpets, queen scallops, carpet shells, or tellins, and more particularly scallop, oyster, or mussel shells.

[0103] In the case of a porous structure, the morphological characteristic(s) may include one or more characteristics of the porous structure, in particular porosity, pore shape, average pore size, and / or pore density per unit area on a given plane. Each type of bird lays eggs with a shell exhibiting a porous structure with its own specific characteristics. The morphological characteristic(s) may allow for the differentiation of eggshell powders from different birds, including chickens, quail, pheasants, turkeys, ostriches, geese, pigeons, or guinea fowl. The morphological characteristic(s) representative of the presence of eggshell powder may be the presence of a porous structure with an average pore diameter, measured in particular by image analysis of the powder, of between 20 nm and 500 nm, preferably between 40 nm and 400 nm.

[0104] In the case of research or analysis of morphological characteristics, this can be done with or without prior incineration, in particular by visualization under a microscope, electron or otherwise. The analysis of morphological characteristics can be carried out by image acquisition, in particular with an electron or optical microscope, with a magnification allowing visualization of the calcium carbonate grains. and the analysis of the acquired images, notably by a computer image analysis algorithm.

[0105] Step 130 may involve determining authenticity or identity information based at least on the bio-based content determined in sample 22, in particular by comparison with a reference bio-based content. Indeed, not all polymers derived at least partially from bio-based material necessarily have the same bio-based content, and it is possible to adjust this content by the proportion of polymers derived from bio-based material in the substrate. It is thus possible to have a specific reference content for authenticating or identifying a safety document. The table below shows, as an example, the bio-based content of several polymers. Examples of synthetic polymers derived from bio-based materials: Bio-based material content: Polyamide: PA 6.6 50 Polyamide: PA 11 100 Polyamide: PA 10.10 100 Polyamide: PA 6.10 62 Polyamide: PA 10.12 45 Polyethylene Terephthalate: PET 100 Polyethylene Furanoate: PEF 100 Polybutylene Succinate: PB S 100

[0106] Alternatively or in addition, step 130 may include determining authenticity or identity information based on the information obtained from the analysis(es). It is thus possible to determine authenticity or identity when the measured content is substantially equal to the reference content.

[0107] Comparing the bio-based material content determined in the sample within window 20 and in the sample outside window 20 allows for the deduction of a difference in content, its quantification, and its comparison to a reference content of bio-based material in the cover layer(s). From this deduction, it is possible to conclude, along with other information, whether or not it provides information of authenticity or identity.

[0108] It is possible to have an authenticity or identity based on the bio-based material content in the substrate in the document window and a morphological structure of the pigment(s) in the coating layer(s), optionally also including the bio-based material content in the layer(s) covering 12, 13 and 14. The combination of these two or three pieces of information provides greater security for the safety document. In this case, the method may be based on one or more of the following reference information: presence of bio-based calcium carbonate in the covering layer(s), a reference content of bio-based calcium carbonate in the covering layer(s), a reference mass proportion of bio-based calcium carbonate or of one or each type of bio-based calcium carbonate in the covering layer(s), a reference morphological characteristic of bio-based calcium carbonate or of one or more types of bio-based calcium carbonate in the covering layer(s),a reference value or range of values ​​representative of a morphological characteristic of bio-based calcium carbonate or of one or more types of bio-based calcium carbonate in the cover layer(s), information on the type(s) of bio-based calcium carbonate present in a reference bio-based calcium carbonate charge in the cover layer(s), and / or the mass proportions of each type of bio-based calcium carbonate in a reference bio-based calcium carbonate charge in the cover layer(s).

[0109] Identification and / or authentication according to the methods indicated above can be automated by a computer implementing a learning algorithm trained on identified and / or authentic reference articles.

[0110] It is therefore possible to have multi-level security ranging from the simple determination of the bio-based material content within the window to the complex composition of the bio-based material safety document both within and outside the window. This allows for multi-level security.

[0111] The invention is not limited to the examples just described. Other safety features than those mentioned may be incorporated into the safety document. The substrate may contain markers of the bio-based content, for example, particles or aggregates of particles that are fluorescent or phosphorescent under a particular light. Other types of bio-based calcium carbonate than those mentioned above are possible, provided they are identifiable and have distinct properties from quarry calcium carbonate.

Claims

Demands

1. Safety document (10) comprising: - a non-opaque polymeric substrate (11) comprising a polymer produced at least partially with at least one bio-based material, and - one or more opacifying cover layers (12, 13, 14) partially covering the substrate (11) and providing at least one window (20) in which the substrate (11) is free of opacifying cover layer.

2. Document according to claim 1, wherein the bio-based material is a renewable and / or biodegradable plant material or a mixture of renewable and / or biodegradable plant materials.

3. Document according to claim 1 or 2, wherein the polymer produced at least partially with at least one bio-based material is selected from polyamide (PA), polyundecanamide (PA11), polyethylene terephthalate (PET), polyethylene furanoate (PEF), polybutylene succinate, polyhydroxy alkanoate, polypropylene (PP), in particular biaxially oriented (BoPP), polylactic acid (PLA), cellulose diacetate (CDA), cellophane films and mixtures thereof.

4. Document according to any one of the preceding claims, wherein the polymer is derived, in a proportion greater than or equal to 20% by mass, better greater than or equal to 50% by mass, even better greater than or equal to 70% by mass, even better greater than or equal to 80% by mass, from bio-based material.

5. Document according to any one of the preceding claims, wherein the substrate (11) is transparent.

6. Document according to any one of the preceding claims, wherein the substrate (11) is free of pigment and / or fillers.

7. Document according to any one of the preceding claims, wherein, in the window, the substrate is present at more than 90% by mass, better at more than 95% by mass, still better at more than 98% by mass.

8. Document according to any one of the preceding claims, comprising at least one area in the window in which only the substrate (11) is present, in particular the entire window.

9. Document according to any one of the preceding claims, wherein the or at least one of the overlay layers (12) is a pigment layer and / or the or at least one of the overlay layers (13) is an impression.

10. Document according to the preceding claim, wherein the pigment layer (12) and / or the printing (13) comprise pigments of bio-based origin.

11. Document according to the preceding claim, wherein the pigments comprise calcium carbonate of bio-based origin, in particular selected from eggshell powders of various birds, in particular chickens, quails, pheasants, turkeys, ostriches, geese, pigeons or guinea fowl, or shellfish, in particular oyster, mussel, scallop, sea almond, periwinkle, cockle, whelk, clam, cockle, razor clam, abalone, clam, limpet, queen scallop, carpet shell or tellin, more particularly scallop, oyster, mussel shells, or mixtures thereof.

12. Document according to claim 10 or 11, wherein the opacifying topcoat (12) comprises bio-based pigments and a binder, the binder being at least partially bio-based, in particular more than 50%, preferably more than 55% bio-based

13. Method of authentication or identification of a secure document, in particular according to any one of the preceding claims, comprising the detection in a window (20) of the security document of the presence of a polymer produced at least partially with at least one bio-based material composing the substrate (11) by detection of the carbon isotope 14 according to ASTM D6866.

14. Method according to claim 13, comprising identifying a window (20) on the security document and extracting a sample (22) from the window, in particular by cutting a portion of the security document from the window.

15. Method according to claim 13 or 14, comprising the detection of the bio-based material content according to ASTM D6866 and the comparison to a reference information to deduce an authenticity or identity information of the safety document at least based on this comparison.

16. A method according to any one of claims 13 to 15, comprising extracting a sample (23) from the window, in particular by cutting a portion of the security document from the window, detecting the bio-based material content according to ASTM D6866 in the sample from the window and comparing it to that determined in the window to deduce authenticity or identity information.

17. A method according to any one of claims 13 to 16, comprising determining the content of bio-based material determined in the sample (22) from the window (20) of the safety document and of one or more markers representative of one or more morphological characteristics of the pigments of bio-based origin determined in the sample (23) from an area outside the window (20) of the safety document and determining authenticity or identity information based on the combination of these two pieces of information.

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